HINGE DEVICE

Abstract

In a hinge device 1, a door-side mounting member 6 is rotatably connected to a housing-side mounting member 3 via an inner link 4 and an outer link 5. To prevent the inner link 4 and the outer link 5 from being rattled, one protrusion 72 of a torsion coil spring 7 as a rotationally biasing mechanism is pressed against one side plate 41 of the inner link 4 via a cam member 91 and the other protrusion 73 of the torsion coil spring 7 is pressed against the other side plate 52 of the outer link 5.

Description

FIELD OF THE INVENTION

The present invention relates to a hinge device that has a torsion spring as a rotationally biasing mechanism.

BACKGROUND OF THE INVENTION

As disclosed in Patent Document 1 listed below, a conventional hinge device of this type generally includes a housing-side mounting member to be attached to a housing and a door-side mounting member to be attached to a door. The door-side mounting member is rotatably connected to the housing-side mounting member via a first link and a second link. As a result, the door is rotatably supported by the housing via the hinge device.

Side plates are respectively formed in opposite side portions of the first link and the second link in directions of rotation axes of the first link and the second link. One end portions of the two side plates of the first link are rotatably connected to the housing-side mounting member via a first central shaft that passes through the two side plates of the first link. Similarly, one end portions of the two side plates of the second link are rotatably connected to the housing-side mounting member via a second central shaft that passes through the two side plates of the second link. It is to be understood that the first central shaft and the second central shaft are parallel to each other.

The hinge device further includes two torsion coil springs. The two torsion coil springs are disposed parallel to the first central shaft and the second central shaft and are arranged in a row. One end portions of the two torsion coil springs that are spaced from each other are respectively pressed against the two side plates of the first link. Thereby, the first link is rotationally biased. The other end portions of the two torsion coil springs that are adjacent to each other are respectively pressed against a portion near a central portion of the second link in an axial direction of the second central shaft. Thereby, the second link is rotationally biased. As a result, the door-side mounting member is rotationally biased by the two torsion coil springs via the first link and the second link.

PRIOR ART DOCUMENTS

Patent Documents

• Patent Document 1: Japanese Unexamined Patent Application Publication No. H06-323055

SUMMARY OF THE INVENTION

Problem to be Solved by the Invention

In the conventional hinge device described above, two torsion coil springs are used, and therefore, the number of components and the number of assembly steps are increased. This results in an increase in manufacturing cost, which is a problem.

Moreover, since the second link is biased in the central portion thereof in the axial direction of the second central shaft, the second link tend to be rattled greatly, which is also a problem. To describe it more in detail, dimension errors that are inevitable in manufacturing exist between the housing-side mounting member and the first central shaft, between the housing-side mounting member and the second central shaft, between the first link and the first central shaft, between the first link and the second central shaft, between the second link and the first central shaft, and between the second link and the second central shaft. Opposite side portions of the first link and the opposite side portions of the second link can be moved with respect to the housing-side mounting member through a distance corresponding to the dimension errors. Positions of the opposite side portions of the first link are generally fixed to the housing-side mounting member since the opposite side portions of the first link are biased by the torsion coil spring. However, since the second link is biased in the central portion thereof, the opposite side portions of the second link can be relatively easily moved with respect to the housing-side mounting member. Therefore, the opposite side portions of the second link may be moved through the distance corresponding to the dimension errors during the rotation of the door, and as a result, the second link may be rattled, which is a problem.

Solution to the Problem

The present invention was made to solve the problems mentioned above. The present invention provides a hinge device including: a housing-side mounting member; a first link having one end portion thereof rotatably supported by the housing-side mounting member via a first central shaft; a second link having one end portion thereof rotatably supported by the housing-side mounting member via a second central shaft; the first central shaft and the second central shaft being parallel to each other; a door-side mounting member, the other end portion of the first link rotatably connected to the door-side mounting member via a third central shaft, the other end portion of the second link rotatably connected to the door-side mounting member via a fourth central shaft; the third central shaft and the fourth central shaft being parallel to the first central shaft and the second central shaft; and one torsion spring rotatably biasing the door-side mounting member, wherein: one end portion of the torsion spring is engaged with a side portion of the first link located at one end side in axial directions of the first central shaft, the second central shaft, the third central shaft and the fourth central shaft so that the torsion spring may rotatably bias the door-side mounting member via the first link and the second link; and the other end portion of the torsion spring is engaged with a side portion of the second link located at the other end side in the axial directions of the first central shaft, the second central shaft, the third central shaft and the fourth central shaft.

In this case, it is preferable that the first link and the second link are rotatably biased by the torsion spring in a same direction.

Preferably, the one end portion of the torsion spring is engaged with the one side portion of the first link via a cam mechanism that may transmit biasing force of the torsion spring to the first link; and the other end portion of the torsion spring is directly engaged with the other side portion of the second link.

Preferably, the one end portion of the torsion spring is directly engaged with the one side portion of the first link; and the other end portion of the torsion spring is directly engaged with the other side portion of the second link.

Preferably, the one end portion of the torsion spring is directly engaged with the one side portion of the first link; and the other end portion of the torsion spring is engaged with the other side portion of the second link via the fourth central shaft.

Preferably, the one end portion of the torsion spring is directly engaged with the one side portion of the first link; and the other end portion of the torsion spring is engaged with the other side portion of the second link via an engagement shaft disposed at the other side portion of the second link.

Preferably, a pair of side plates opposed to each other are respectively disposed in one side portion and the other side portion of the one end portion of the first link in the axial direction of the first central shaft; the first central shaft rotatably extends through the pair of side plates, thereby the one end portion of the first link rotatably supported by the housing-side mounting member; a pair of side plates opposed to each other are respectively disposed in one side portion and the other side portion of the one end portion of the second link in the axial direction of the second central shaft; the second central shaft rotatably extends through the pair of side plates, thereby the one end portion of the second link rotatably supported by the housing-side mounting member; the one end portion of the torsion spring is engaged with the side plate of the first link, the side plate being disposed closer to a one end of the first link than the side plate in the axial directions of the first central shaft and the second central shaft; and the other end portion of the torsion spring is engaged with the side plate of the second link, the side plate being disposed closer to the other end of the second link than the side plate in the axial directions of the first central shaft and the second central shaft.

Preferably, the torsion spring is a torsion coil spring; and a support shaft is disposed in the housing-side mounting member so as to be parallel to the first central shaft and the second central shaft, the support shaft extending through a coil portion of the torsion coil spring, thereby the torsion coil spring being supported by the housing-side mounting member via the support shaft.

Preferably, the first link comprises a plurality of link constituents that are formed separately from each other; the plurality of link constituents are spaced from each other in the axial direction of the first central shaft; and the one end portion of the torsion spring is engaged with the link constituent that is located on the most one end side in the axial direction of the first central shaft.

Advantageous Effects of the Invention

According to the present invention having the features mentioned above, since the first link and the second link are biased by only one torsion spring, the number of components can be reduced and the number of assembly steps can be reduced compared with when two torsion springs are used. Accordingly, the manufacturing cost of the hinge device can be reduced.

Moreover, the first link is biased by the torsion spring only at the one side portion thereof, and the position of the one side portion is generally fixed to the housing-side mounting member by the biasing force of the torsion spring. Accordingly, only the other side portion of the first link is moved with respect to the housing-side mounting member. Therefore, the rattle of the first link can be reduced by half compared with when the central portion is biased, and as a result, the opposite side portions are moved with respect to the housing-side mounting member. The same applies to the second link, only the other side portion of which is biased by the torsion spring.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plan view of a first embodiment of the present invention, showing a door-side mounting member in an open position.

FIG. 2 is a view on arrow X of FIG. 1.

FIG. 3 is a view on arrow Y of FIG. 1.

FIG. 4 is a view on arrow Z of FIG. 1.

FIG. 5 is a perspective view of the first embodiment, showing the door-side mounting member in the open position.

FIG. 6 is an exploded perspective view of a base and a housing-side mounting member used in the first embodiment.

FIG. 7 is an exploded perspective view of the housing-side mounting member and the door-side mounting member and other parts disposed between them used in the first embodiment.

FIG. 8 is an enlarged cross-sectional view taken along line A-A of FIG. 1.

FIG. 9 is a view similar to FIG. 8, showing the door-side mounting member in an intermediate position between a closed position and the open position.

FIG. 10 is a view similar to FIG. 8, showing the door-side mounting member in the closed position.

FIG. 11 is a partially-omitted cross-sectional view taken along line B-B of FIG. 1.

FIG. 12 is a cross-sectional view similar to FIG. 11, showing the door-side mounting member in the intermediate position.

FIG. 13 is a cross-sectional view similar to FIG. 11, showing the door-side mounting member in the closed position.

FIG. 14 is a partially-omitted cross-sectional view taken along line C-C of FIG. 1.

FIG. 15 is a cross-sectional view similar to FIG. 14, showing the door-side mounting member in the intermediate position.

FIG. 16 is a cross-sectional view similar to FIG. 14, showing the door-side mounting member in the closed position.

FIG. 17 is a cross-sectional view taken along line A-A of FIG. 2.

FIG. 18 is an enlarged view of a main portion of FIG. 17.

FIG. 19 is a side view of a rotary damper used in the first embodiment.

FIG. 20 is a right side view of the rotary damper.

FIG. 21 is a perspective view of the rotary damper.

FIG. 22 is a cross-sectional view taken along line X-X of FIG. 19, showing the rotary damper rotated in a closing direction.

FIG. 23 is a cross-sectional view similar to FIG. 22, showing the rotary damper rotated in an opening direction.

FIG. 24 is a cross-sectional view taken along line X-X of FIG. 22, showing a damper body in a first position.

FIG. 25 is a cross-sectional view taken along line X-X of FIG. 23, showing the damper body in the first position.

FIG. 26 is a cross-sectional view taken along line X-X of FIG. 22, showing the damper body in a second position.

FIG. 27 is a cross-sectional view taken along line Y-Y of FIG. 22, showing the damper body in the first position.

FIG. 28 is a cross-sectional view taken along line Y-Y of FIG. 22, showing the damper body in the second position.

FIG. 29 is an enlarged view of a main portion of FIG. 2.

FIG. 30 is a cross-sectional view of a hinge device with damper according to a second embodiment of the present invention similar to FIG. 8, showing the door-side mounting member in the closed position.

FIG. 31 is a cross-sectional view of the second embodiment similar to FIG. 8, showing the door-side mounting member in a predetermined first intermediate position.

FIG. 32 is a cross-sectional view of the second embodiment similar to FIG. 8, showing the door-side mounting member in a predetermined second intermediate position.

FIG. 33 is a cross-sectional view of the second embodiment similar to FIG. 8, showing the door-side mounting member in an open position.

FIG. 34 is a perspective view of another example of a torsion coil spring used in the present invention.

FIG. 35 is an exploded perspective view of a third embodiment of the present invention.

FIG. 36 is an exploded perspective view of the third embodiment, viewed from a different direction from FIG. 35.

FIG. 37 is a cross-sectional view similar to FIG. 18, showing the third embodiment.

FIG. 38 is a perspective view of an outer link used in the third embodiment.

FIG. 39 is a plan view of a fourth embodiment of the present invention, showing the hinge device attached to the housing and the door.

FIG. 40 is a cross-sectional view taken along line X-X of FIG. 39, showing the hinge device according to the fourth embodiment with the door in a closed position.

FIG. 41 is a cross-sectional view taken along line X-X of FIG. 39, showing the hinge device according to the fourth embodiment with the door in an intermediate position.

FIG. 42 is a cross-sectional view taken along line X-X of FIG. 39, showing the hinge device according to the fourth embodiment with the door in an open position.

FIG. 43 is an exploded perspective view of a main portion of the hinge device according to the fourth embodiment.

FIG. 44 is a cross-sectional view of a fifth embodiment of the present invention, with the door in the closed position.

FIG. 45 is a cross-sectional view of the fifth embodiment with the door in the intermediate position.

FIG. 46 is a cross-sectional view of the fifth embodiment with the door in the open position.

FIG. 47 is an exploded perspective view of a main portion of the fifth embodiment.

FIG. 48 is a cross-sectional view of a sixth embodiment of the present invention with the door in the closed position.

FIG. 49 is a cross-sectional view of the sixth embodiment with the door in the intermediate position.

FIG. 50 is a cross-sectional view of the sixth embodiment with the door in the open position.

FIG. 51 is an exploded perspective view of a seventh embodiment of the present invention.

FIG. 52 is an exploded perspective view of the seventh embodiment, viewed from a different direction from FIG. 51.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

A best mode for carrying out the invention will be described hereinafter with reference to the drawings.

FIGS. 1 to 29 show a first embodiment of the present invention. As shown in FIGS. 1 to 8, a hinge device 1 of this embodiment includes as major constituents thereof a base 2, a hinge body (housing-side mounting member) 3, an inner link (first link) 4, an outer link (second link) 5, a cupped member (door-side mounting member) 6, a torsion coil spring 7 and a rotary damper 8.

The base 2 is provided for removably attaching the hinge body 3 to an inner surface of a side wall of a housing (not shown) having an opening in a front thereof. The base 2 includes a base plate 21 and a movable plate 22. The base plate 21 is attached to a front end portion of an inner surface of a left side wall, i.e., an end portion of the left side wall on the opening side, of the housing. Alternatively, the base plate 21 may be attached to a front end portion of an inner surface of a right side wall of the housing. For the ease of description, front-rear, left-right and vertical directions used in describing features of the hinge device 1 hereinafter respectively refer to front-rear, left-right and vertical directions of the housing. The front-rear, left-right and vertical directions of the housing are as shown in FIGS. 6 and 7. It is to be understood that the hinge device 1 is not limited to such front-rear, left-right and vertical directions.

The movable plate 22 is attached to the base plate 21 such that a position of the movable plate 22 can be adjusted in the front-rear direction and the vertical direction. When an adjustment shaft 23 is rotated, the position of the movable plate 22 is adjusted in the front-rear direction. When an adjustment shaft 24 is rotated, the position of the movable plate 22 is adjusted in the vertical direction. When an adjustment bolt 25 is rotated, the position of a front end portion of the movable plate 22 is adjusted in the left-right direction.

An engagement recess 22a is formed in the front end portion of the movable plate 22. The engagement recess 22a is open toward the front. An engagement shaft 22b is fixed to a rear end portion of the movable plate 22 with a longitudinal direction of the engagement shaft 22b oriented in the vertical direction.

As shown in FIGS. 6 to 8, the hinge body 3 includes a pair of side plates 31, 32 and a connecting plate 33. The pair of side plates 31, 32 are disposed such that longitudinal directions of the pair of side plates 31, 32 are oriented in the front-rear direction and the side plates 31, 32 are opposed to each other in the vertical direction. The connecting plate 33 is integrally disposed in right side portions (upper side portions in FIG. 6) of longer side portions of the pair of side plates 31, 32. Thereby, the hinge body 3 has a U-shaped cross-section. The hinge body 3 is disposed with an open portion thereof oriented toward the base 2.

The movable plate 22 is disposed inside the hinge body 3. As shown in FIGS. 7 and 8, opposite end portions of an engagement shaft 34 are respectively fixed to front end portions of the side plates 31, 32 of the hinge body 3. A longitudinal direction of the engagement shaft 34 is oriented in the vertical direction. The engagement shaft 34 is removably inserted in the engagement recess 22a of the movable plate 22. As shown in FIG. 8, opposite end portions of a support shaft 35 are respectively fixed to rear end portions of the side plates 31, 32 of the hinge body 3. A longitudinal direction of the support shaft 35 is oriented in the vertical direction. An engagement member 36 is rotatably disposed at the support shaft 35. The engagement member 36 is rotatably biased in a clockwise direction of FIG. 8 by a coil spring 37. An engagement recess 36a is formed in the engagement member 36. The engagement shaft 22b disposed in the rear end portion of the movable plate 22 is removably inserted in the engagement recess 36a. The engagement shaft 34 is removably inserted in the engagement recess 22a and the engagement shaft 22b is removably inserted in the engagement recess 36a of the engagement member 36. Thereby, the hinge body 3 is removably attached to the base 2, and thereby removably attached to the housing. An attaching structure of the hinge body 3 to the housing is not limited to the one described above, but other structures that are known in the art may be adopted. Alternatively, the hinge body 3 may be directly fixed to the housing, for example, by forming vertical flanges protruding upward or downward respectively in the side plates 31, 32, and fixing the vertical flanges to the inner surface of the left side wall or the right side wall of the housing.

One end portions of the inner link 4 and the outer link 5 are respectively rotatably connected to the front end portions of the side plates 31, 32 of the hinge body 3. Specifically, opposite end portions of a first central shaft J1 and a second central shaft J2 are respectively fixed in the front end portions of the side plates 31, 32. Longitudinal directions of the central shafts J1, J2 are oriented in the vertical direction. The inner link 4 is composed of a pair of side plates 41, 42 opposed to each other in the vertical direction and a connecting plate 43 connecting the pair of side plates 41, 42 at longer side portions of the side plates 41, 42. One end portions of the side plates 41, 42 are disposed between the side plates 31, 32 and are connected to the side plates 31, 32 such that the side plates 41, 42 are rotatable about the first central shaft J1 in the horizontal direction. By this arrangement, one end portion of the inner link 4 is connected to a front end portion of the hinge body 3 such that the inner link 4 is rotatable in the horizontal direction.

The outer link 5 is composed of a pair of side plates 51, 52 opposed to each other in the vertical direction and a connecting plate 53 connecting the pair of side plates 51, 52 at longer side portions of the side plates 51, 52. One end portions of side plates 51, 52 are disposed between the side plates 31, 32 and are connected to the side plates 31, 32 such that the side plates 51, 52 are rotatable about the second central shaft J2 in the horizontal direction. By this arrangement, one end portion of the outer link 5 is connected to the front end portion of the hinge body 3 such that the outer link 5 is rotatable in the horizontal direction.

The cupped member 6 is fixed to a rear surface of a door (not shown), that is a surface of the door that faces the front surface of the housing when the door is in the closed position. A connector 61 having a generally U-shaped configuration is fixed to the cupped member 6. The connector 61 includes a pair of shaft portions 62, 63 disposed parallel to each other. Longitudinal directions of the pair of shaft portions 62, 63 are oriented in the vertical direction. Accordingly, the shaft portions 62, 63 are arranged parallel to the first and second central shafts J1, J2.

The other end portions of the side plates 41, 42 of the inner link 4 are connected to the cupped member 6 such that the side plates 41, 42 are rotatable about the shaft portion (third central shaft) 62 in the horizontal direction. The other end portions of the side plates 51, 52 of the outer link 5 are connected to the cupped member 6 such that the side plates 51, 52 are rotatable about the shaft portion (fourth central shaft) 63 in the horizontal direction. By this arrangement, the cupped member 6 is connected to the hinge body 3 such that the cupped member 6 is rotatable in the horizontal direction via the inner link 4 and the outer link 5. Thereby, the door is connected to the housing such that the door is rotatable in the horizontal direction via the hinge device 1.

The cupped member 6 is rotatable with respect to the hinge body 3 between a closed position shown in FIGS. 10 and 13 and an open position shown in FIGS. 8 and 11. As shown in FIG. 10, the closed position of the cupped member 6 is determined by the abutment of the connecting plate 53 of the outer link 5 against a bottom 6a of the cupped member 6. However, the cupped member 6 does not actually reach the closed position when the hinge device 1 is mounted to the housing. This is because the door is abutted against the front surface of the housing before the outer link 5 is abutted against the cupped member 6. Positions of the cupped member 6 and the door when the door is abutted against the front surface of the housing are referred to as “closed positions” hereinafter. The open position of the cupped member 6 is determined by the abutment of the side plates 41, 42 of the inner link 4 against the cupped member 6.

As shown in FIGS. 7 and 8, opposite end portions of a support shaft J3 are supported by the side plates 31, 32 of the hinge body 3. A longitudinal direction of the support shaft J3 is oriented in the vertical direction. The support shaft J3 is disposed slightly behind the central shafts J1, J2 and to the right of the central shafts J1, J2. A coil portion 71 of the torsion coil spring (torsion spring) 7 is disposed around the support shaft J3. The coil portion 71 is composed of a wound wire rod having a rectangular cross-section.

Protrusions 72, 73 are provided at opposite end portions of the coil portion 71 of the torsion coil spring 7. The protrusions 72, 73 are one end portion and the other end portion of the wire rod constituting the coil portion 71. The protrusions 72, 73 are protruded from the coil portion 71 outward in a radial direction.

As shown in FIGS. 11 to 13, the protrusion (one end portion) 72 of the torsion coil spring 7 is abutted against one of the side plates 41 of the inner link 4 via a cam member 91. The cam member 91 has a configuration of a flat plate. The cam member 91 is disposed between the side plate 31 of the hinge body 3 and the coil portion 71 of the torsion coil spring 7. The support shaft J3 is rotatably disposed through the cam member 91. Accordingly, the cam member 91 is rotatably supported by the support shaft J3. A pair of protrusions 91c, 91c (only one protrusion 91c is shown) are disposed in a surface of the cam member 91 opposed to the protrusion 72. The pair of protrusions 91c, 91c are spaced from each other. The protrusion 72 of the torsion coil spring 7 is disposed between the pair of protrusions 91c, 91c such that the protrusion 72 is non-movable in a circumferential direction of the coil portion 71. As a result, the cam member 91 is rotationally biased about an axis thereof (axis of the support shaft J3) by the torsion coil spring 7.

A cam surface 91a is formed in a portion of a front end portion of the cam member 91 that is opposed to the side plate 41. A cam surface 41a is formed in the side plate 41 that is opposed to the cam surface 91a. The cam surfaces 91a, 41a are abutted against each other by the torsion coil spring 7. Accordingly, rotationally biasing force of the torsion coil spring 7 acts on the inner link 4 via the cam surfaces 91a, 41a. As is clear from the foregoing, the cam surfaces 41a, 91a constitute a cam mechanism. Specifically, the rotationally biasing force of the torsion coil spring 7 that acts on the inner link 4 does not act (the rotationally biasing force is zero) when the cupped member 6 is in the open position. When the cupped member 6 is rotated from the open position toward the closed position, the rotationally biasing force of the torsion coil spring 7 acts to rotate the cupped member 6 toward the closed position. Moreover, the rotationally biasing force acting on the inner link 4 is increasingly increased as the cupped member approaches the closed position. The cam surfaces 91a, 41a are formed in such a manner that allows the rotationally biasing force to act on the inner link 4 in this way. It is to be understood that it is also possible to form the cam surfaces 91a, 41a in such a manner that allows the rotationally biasing force to act on the inner link 4 in a different mode from the one mentioned above. In this way, when the protrusion 72 is contacted with the inner link 4 via the cam member 91, the rotationally biasing force acting on the inner link 4 is allowed much greater flexibility in the mode of action compared with when the protrusion 72 is directly contacted with the inner link 4.

As mentioned above, except when the cupped member 6 is in the open position, the torsion coil spring 7 rotationally biases the inner link 4 in a counter-clockwise direction of FIGS. 11 to 13 about the central shaft J1, thereby rotationally biasing the cupped member 6 in a direction from the open position toward the closed position (to be referred to as a “closing direction” hereinafter). Accordingly, when the cupped member 6 is rotated from the open position toward the closed position through a slight angle, 5 to 10 degrees, for example, the cupped member 6 is then rotated to the closed position and maintained at the closed position by the torsion coil spring 7. When the cupped member 6 is at the open position, a normal line to portions of the cam surfaces 91a, 41a contacted with each other (line of action of the rotationally biasing force of the torsion coil spring 7 acting on the inner link 4) orthogonally crosses an axis of the central shaft J1. Therefore, the inner link 4 is not rotationally biased by the rotationally biasing force of the torsion coil spring 7. The torsion coil spring 7 may bias the inner link 4 in other modes. For example, the rotationally biasing force of the torsion coil spring 7 may act on the inner link 4 only when the cupped member 6 is positioned between the closed position and a generally inter mediate position between the open position and the closed position. But the rotationally biasing force of the torsion coil spring 7 may not act on the inner link 4 when the cupped member 6 is positioned between the intermediate position and the open position. Alternatively, as in a well-known hinge device, the torsion coil spring 7 may rotationally bias the inner link 4 such that the cupped member 6 is rotated in the closing direction when the cupped member 6 is positioned between the closed position and a predetermined neutral position (change point position). And the torsion coil spring 7 may rotationally bias the inner link 4 such that the cupped member 6 is rotated in a direction from the closed position toward the open position (to be referred to as an “opening direction” hereinafter) when the cupped member 6 is positioned between the neutral position and the open position.

As shown in FIGS. 14 to 16, the other protrusion (the other end portion) 73 of the torsion coil spring 7 is directly abutted against the side plate 52 of the outer link 5 that is located on the other end side of the outer link 5 in an axial direction of the second central shaft J2. Thereby, except when the cupped member 6 is in the open position, the torsion coil spring 7 rotationally biases the outer link 5 in a counter-clockwise direction of FIGS. 14 to 16 about the central shaft J2, thereby rotationally biasing the cupped member 6 in the closing direction. When the cupped member 6 is at the open position, a normal line to portions of the protrusion 73 and the outer link 5 contacted with each other (line of action of the rotationally biasing force of the torsion coil spring 7 acting on the outer link 5) orthogonally crosses an axis of the central shaft J2. Therefore, the outer link 5 is not rotationally biased by the rotationally biasing force of the torsion coil spring 7.

A magnitude of a biasing force of the one protrusion 72 biasing the inner link 4 via the cam member 91 and a magnitude of a biasing force of the other protrusion 73 biasing the outer link 5 is equal to each other. However, a magnitude of a rotationally biasing force (rotational moment) acting on the inner link 4 and a magnitude of a rotationally biasing force acting on the outer link 5 are different when the links 4, 5 are at most of the rotational positions except for some rotational positions. The cupped member 6 is rotationally biased by the rotationally biasing force acting on the links 4, 5. Therefore, in order to obtain a rotationally biasing force of desired magnitude suitable for the rotational position of the cupped member 6, it is required to properly adjust the rotationally biasing force acting on the links 4, 5. However, when both of the protrusions 72, 73 are formed in linear shapes, it is difficult to obtain a rotationally biasing force of desired magnitude acting on the cupped member 6 by properly adjusting the rotationally biasing force acting on the links 4, 5. In this respect, in the hinge device 1, the protrusion 72 is contacted with the inner link 4 via the cam member 91. Therefore, by designing a shape of the cam surface 91a of the cam member 91 taking into consideration the rotationally biasing force acting on the outer link 5, a rotationally biasing force acting on the cupped member 6 having a desired magnitude suitable for a rotational position of the cupped member 6 can be obtained.

While the one protrusion 72 of the torsion coil spring 7 is abutted against the side plate 41 of the inner link 4 via the cam member 91, the protrusion 72 may be directly abutted against the side plate 41. Alternatively, the protrusion 72 may be abutted against a portion of the connecting plate 43 adjacent to the side plate 41 directly or via a cam. The other protrusion 73 may be abutted against the side plate 52 of the outer link 5 via a cam member. Alternatively, the protrusion 73 may be abutted against a portion of the connecting plate 53 adjacent to the side plate 52.

As shown in FIG. 7 and FIGS. 11 to 13, a cylindrical portion 91b is formed in a surface of the cam member 91 opposed to the coil portion 71. The support shaft J3 is rotatably disposed through the cylindrical portion 91b. An outer diameter of the cylindrical portion 91b is slightly smaller than an inner diameter of the coil portion 71. The cylindrical portion 91b is relatively rotatably fitted in one end portion of the coil portion 71 with a slight gap therebetween. As a result, the one end portion of the coil portion 71 is securely supported by the cylindrical portion 91b without any inhibitory effect on expansion and contraction of diameter accompanying torsion of the torsion coil spring 7.

As shown in FIG. 7 and FIGS. 14 to 16, a spacer 92 is disposed between the side plate 32 of the hinge body 3 and the torsion coil spring 7. The support shaft J3 is rotatably disposed through the spacer 92. A pair of protrusions 92a, 92a are formed in a surface of the spacer 92 opposed to the protrusion 73 such that the protrusions 92a, 92a are spaced from each other. The protrusion 73 is disposed between the pair of protrusions 92a, 92a such that the protrusion 73 is non-movable in the circumferential direction of the coil portion 71. Accordingly, the spacer 92 is rotatable about an axis of the torsion coil spring 7 together with the protrusion 73. A cylindrical portion 92b is formed in a surface of the spacer 92 opposed to the coil portion 71. The support shaft J3 is rotatably disposed through the cylindrical portion 92b. An outer diameter of the cylindrical portion 92b is slightly smaller than the inner diameter of the coil portion 71. The cylindrical portion 92b is relatively rotatably fitted in the other end portion of the coil portion 71. As a result, the other end portion of the coil portion 71 is securely supported by the cylindrical portion 92b without inhibitory effect on expansion and contraction of diameter accompanying the torsion of the torsion coil spring 7.

One protrusion 72 of the torsion coil spring 7 is contacted with the inner link 4 at the one side plate 41 only. That is, the inner link 4 is biased by the torsion coil spring 7 only at the one side plate 41. Therefore, position of a one side portion of the inner link 4 is generally fixed to the housing-side mounting member 3. The other side portion of the inner link 4 is movable with respect to the housing-side mounting member 3 in a radial direction of the first central shaft J1 through a distance corresponding to a manufacturing error because the other side portion of the inner link 4 is not biased by the torsion coil spring 7. The inner link 4 is movable only at the other side portion thereof. Therefore, rattles of the inner link 4 can be reduced by half compared with when opposite side portions of the inner link 4 can be moved. The same applies to the outer link 5 of which only the side plate 52 is biased by the torsion coil spring 7. Thus, the rattle of the inner link 4 and the outer link 5 during the rotation of the door to be opened or closed can be reduced by half.

As shown in FIGS. 17 and 18, the rotary damper 8 is disposed between the side plates 41, 42 of the inner link 4. The rotary damper 8 is disposed for controlling the rotation speeds of the inner link 4 and the outer link 5 to be at low speeds, thereby controlling the rotation speeds of the door and the cupped member 6 to be at low speeds, when the door and the cupped member 6 are rotated in the closing direction. As shown in FIG. 7 and FIGS. 17 to 28, the rotary damper 8 includes a damper body 81 and a rotor 82.

As shown in FIGS. 24 to 28, the damper body 81 has a configuration of bottomed circular cylinder whose one end is open and the other end portion is closed by a bottom 81a. An inner portion of the damper body 81 is a receiving portion 81A. The damper body 81 is disposed between the side plates 41, 42 such that the open portion of the damper body 81 is opposed to the side plate 41 of the inner link 4. Moreover, the damper body 81 is coaxially aligned with the central shaft J1. A through hole 81b is formed in a central portion of the bottom 81a. The through hole 81b is coaxially aligned with the central shaft J1.

The rotor 82 includes a large-diameter portion 82a and a small-diameter portion 82b that are coaxially formed. The large-diameter portion 82a is rotatably fitted in an end portion of an inner circumferential surface of the damper body 81 on the opening side. The small-diameter portion 82b is rotatably fitted in the through hole 81b. By this arrangement, the damper body 81 and the rotor 82 are rotatable with respect to each other about axes thereof (axis of the central shaft J1).

A support hole 82d is formed in a central portion of the rotor 82 such that the support hole 82d extends through the rotor 82 form one end surface of the rotor 82 to the other end surface of the rotor 82 along the axis of the rotor 82. The central shaft J1 is rotatably disposed through the support hole 82d. Thereby, the rotor 82 is rotatably supported by the hinge body 3 via the central shaft J1, thereby the rotary damper 8 being rotatably supported by the hinge body 3. Alternatively, the rotary damper 8 may be rotatably supported by the central shaft J2. In this case, the rotary damper 8 may be disposed between the side plates 51, 52 of the outer link 5. Alternatively, the rotary damper 8 may be rotatably supported by another shaft that are parallel to the central shafts 31, 32. In this case, the rotary damper 8 may be disposed outside of the inner link 4 and the outer link 5.

As shown in FIGS. 7, 8 and FIGS. 19 to 23, two teeth (external gear portions) 81c, 81d are formed in an outer circumferential surface of the damper body 81 such that the teeth 81c, 81d are spaced from each other in a circumferential direction. The two teeth 81c, 81d constitute parts of a gear disposed about the axis of the damper body 81.

As shown in FIGS. 7 to 10, the central shaft J2 is rotatably disposed through a gear member 93. The gear member 93 is disposed between the side plates 51, 51 of the outer link 5 and the gear member 93 is non-rotatably connected to the outer link 5. Accordingly, the gear member 93 is rotated together with the outer link 5 about the central shaft J2.

A tooth 93a is formed in the gear member 93. The tooth 93a is engageable with the teeth 81c, 81d formed in the damper body 81. As shown in FIG. 10, when the cupped member 6 is positioned in an engageable range between the closed position and an engagement start position spaced from the closed position toward the open position by a predetermined angle, the tooth 93a is positioned in between the teeth 81c, 81d. Therefore, when the cupped member 6 is positioned in the engageable range, the tooth 93a is engaged with the teeth 81c, 81d and causes the damper body 81 to be rotated accompanying the rotation of the outer link 5. To be more specific, when the cupped member 6 is rotated in the opening direction, the tooth 93a is engaged with the tooth 81c and causes the damper body 81 to be rotated in a counter-clockwise direction in FIG. 10. When the cupped member 6 is rotated in the closing direction, the tooth 93a is engaged with the tooth 81d and causes the damper body 81 to be rotated in a clockwise direction in FIG. 10. As is clear from this, the gear member 93 and the teeth 81c, 81d engageable with the tooth 93a of the gear member 93 constitute a second rotation transmission mechanism that transmits the rotation of the outer link 5 to the damper body 81. When the rotary damper 8 is mounted around the central shaft J2, the gear member 93 is mounted around the central shaft J1 and rotated together with the inner link 4.

When the cupped member 6 is positioned between the engagement start position and the open position, i.e. outside of the engageable range, the tooth 93a of the gear member 93 is positioned outside of between the teeth 81c, 81d and do not engage with the teeth 81c, 81d. Therefore, in this condition, the damper body 81 can be freely rotated with respect to the gear member 93, and thereby, with respect to the outer link 5. However, even in this condition, the damper body 81 is not freely rotated alone, but the damper body 81 is rotated together with the rotor 82, as will be described later.

As shown in FIGS. 19 to 21, a plurality of (three in this embodiment) protrusions 82c are formed in an end surface of the large-diameter portion 82a of the rotor 82 opposed to the side plate 41. The plurality of protrusions 82c are disposed on a circle about an axis of the rotor 82. The protrusions 82c may be disposed on circles having different diameters. Only one protrusion 82c may be formed.

As shown in FIG. 7, holes 41b of the same number as the protrusions 82c are formed in a portion of the side plate 41 of the inner link 4 opposed to the large-diameter portion 82a. The protrusions 82c are respectively disposed in the holes 41b. By this arrangement, the rotor 82 is rotated together with the inner link 4. Accordingly, when the cupped member 6 is rotated in the closing direction, the rotor 82 is rotated in a counter-clockwise direction in FIGS. 22 and 23, and when the cupped member 6 is rotated in the opening direction, the rotor 82 is rotated in a clockwise direction in FIGS. 22 and 23. As is clear from this, the holes 41b and the protrusions 82c constitute a catch mechanism (first rotation transmission mechanism) that causes the rotor 82 to be rotated about the central shaft J1 together with the one end portion of the inner link 4.

When the cupped member 6 is positioned in the engageable range, a direction of rotation of the one end portion of the inner link 4 about the central shaft J1 and a direction of rotation of the one end portion of the outer link 5 about the central shaft J2 are the same. However, since the rotation of the outer link 5 is transmitted to the damper body 81 via the gear member 93, a direction of rotation of the damper body 81 and a direction of rotation of the rotor 82 are opposite from each other. Accordingly, relative rotation speeds of the damper body 81 and the rotor 82 with respect to each other are faster than when, for example, one of the damper body 81 and the rotor 82 is non-rotatably disposed in the hinge body 3 and only the other of them is rotated.

The rotation transmission mechanism between the damper body 81 and the outer link 5 and the rotation transmission mechanism between the rotor 82 and the inner link 4 are not limited to the embodiment mentioned above and various modifications can be made. For example, a protrusion corresponding to the protrusion 82c may be formed in an outer end surface of the bottom 81a of the damper body 81, i.e., an end surface of the bottom 81a that is opposed to the side plate 42, and a hole corresponding to the hole 41b may be formed in the side plate 42. And by disposing the protrusion in the hole, the damper body 81 may be made to be rotated together with the inner link 4. In this case, teeth corresponding to the teeth 81c, 81d may be formed in an outer circumferential surface of a portion of the rotor 82 that is protruded outside from the damper body 81, and the tooth 93a of the gear member 93 may be engaged with these teeth. Such a modification can also be applied when the rotary damper 8 is disposed around the central shaft J2.

As mentioned above, the large-diameter portion 82a of the rotor 82 is fitted in the end portion of the inner circumferential surface of the damper body 81 on the opening side and the small-diameter portion 82b is fitted in the through hole 81b of the bottom 81a. Accordingly, as shown in FIG. 18, an annular space 83 having opposite end portions thereof closed by the bottom 81a of the damper body 81 and the large-diameter portion 82a of the rotor 82 is formed between the inner circumferential surface of the damper body 81 and an outer circumferential surface of the small-diameter portion 82b. The space 83 is sealed from the outside by a gap between the inner circumferential surface of the damper body 81 and an outer circumferential surface of the large-diameter portion 82a being sealed by a seal member 84 such as an O-ring and a gap between an inner circumferential surface of the through hole 81b and the outer circumferential surface of the small-diameter portion 82b being sealed by a seal member 85 such as an O-ring. The space 83 is filled with fluid. The fluid may be selected from various kinds of fluid used in the conventional rotary dampers such as viscous fluid.

The large-diameter portion 82a and the small-diameter portion 82b of the rotor 82 are respectively fitted in the inner circumferential surface of the damper body 81 and the inner circumferential surface of the through hole 81b such that the large-diameter portion 82a and the small-diameter portion 82b are movable in the axial direction of the damper body 81. Accordingly, the damper body 81 and the rotor 82 are movable in the axial direction of the damper body 81 and the rotor 82 with respect to each other. In this embodiment, the rotor 82 is fixed in position and the damper body 81 is movable with respect to the rotor 82. It is to be understood that the damper body 81 may be fixed in position and the rotor 82 may be movable with respect to the damper body 81 or, alternatively, both of the damper body 81 and the rotor 82 may be movable with respect to each other. The damper body 81 is movable between a first position shown in FIGS. 24, 25 and 27 and a second position shown in FIGS. 26 and 28. A distance between the first position and the second position (to be referred to as “spaced distance” hereinafter) is small, in the order of 0.1 to 0.2 mm, for example.

As shown in FIGS. 22 and 23, a pair of partition wall portions 81e, 81f are formed in a portion of the inner circumferential surface of the damper body 81 facing the space 83. The partition wall portions 81e, 81f are disposed away from each other by 180 degrees in the circumferential direction of the damper body 81. The partition wall portions 81e, 81f extend in an axial direction of the damper body 81. One end portions of the partition wall portions 81e, 81f are integrally formed in the bottom 81a. Specifically, the partition wall portions 81e, 81f extend from the bottom 81a toward the opening. As shown in FIG. 27, a length of the partition wall portions 81; 81f is equal to a distance between the bottom 81a and the large-diameter portion 82a when the damper body 81 is in the first position. Accordingly, when the damper body 81 is in the first position, end surfaces of the partition wall portions 81e, 81f on the opening side (to be referred to as “distal end surfaces” hereinafter) are in contact with the large-diameter portion 82a. However, when the damper body 81 is in the second position, as shown in FIG. 28, the distal end surfaces of the partition wall portions 81e, 81f are spaced form the large-diameter portion 82a by a distance equal to the spaced distance.

As shown in FIGS. 22 to 26, a pair of protrusions 82e, 82f are formed in a portion of the small-diameter portion 82b of the rotor 82 facing the space 83. The protrusions 82e, 82f are disposed away from each other by 180 degrees in a circumferential direction of the rotor 82 (the circumferential direction of the damper body 81). Moreover, the protrusions 82e, 82f are arranged so as to be respectively disposed in spaces between the partition wall portions 81e, 81f. The protrusions 82e, 82f extend in the axial direction of the rotor 82 (the axial direction of the damper body 81). One end portions of the protrusions 82; 82f are integrally formed in the large-diameter portion 82a. Specifically, the protrusions 82; 82f extend from the large-diameter portion 82a toward the bottom 81a. A length of the protrusions 82e, 82f is equal to the length of the partition wall portions 81e, 81f. Accordingly, as shown in FIGS. 24 and 25, when the damper body 81 is in the first position, end surfaces of the protrusions 82e, 82f on the bottom 81a side (to be referred to as “distal end surfaces” hereinafter) are in contact with the bottom 81a. However, when the damper body 81 is in the second position, as shown in FIG. 26, the distal end surfaces of the protrusions 82e, 82f are spaced form the bottom 81a by a distance equal to the spaced distance.

As shown in FIGS. 22, 24, 27 and 28, inner end surfaces of the partition wall portions 81e, 81f, i.e., end surfaces of the partition wall portions 81e, 81f that are located inside in a radial direction of the damper body 81, are rotatably contacted with the outer circumferential surface of the small-diameter portion 82b. As shown in FIGS. 24 to 26, outer end surfaces of the protrusions 82e, 82f, i.e., end surfaces of the protrusions 82e, 82f that are located outermost in a radial direction of the rotor 82, are rotatably contacted with the inner circumferential surface of the damper body 81. As a result, the space 83 is divided into four spaces arranged in the circumferential direction by the partition wall portions 81e, 81f and the protrusions 82e, 82f. Of the four spaces, the space divided by the partition wall portion 81e and the protrusion 82e and the space divided by the partition wall portion 81f and the protrusion 82f are referred to as high pressure chambers 83A and the space divided by the partition wall portion 81e and the protrusion 82f and the space divided by the partition wall portion 81f and the protrusion 82e are referred to as low pressure chambers 83B.

As shown in FIGS. 22 to 26, recesses 82g, 82h are respectively formed in the protrusions 82e, 82f. As shown in FIGS. 22 and 23, one of the high pressure chambers 83A and one of the low pressure chambers 83B are communicated with each other via the recess 82g and the other of the high pressure chambers 83A and the other of the low pressure chambers 83B are communicated with each other via the recess 82h. The recesses 82g, 82h are respectively opened and closed by valves 85A, 85B.

Specifically, as shown in FIGS. 22 and 23, outer portions of the valves 85A, 85B in the radial direction of the damper body 81 are slidably and sealingly contacted with the inner circumferential surface of the damper body 81 facing the space 83 with a predetermined pressing force. Inner portions of the valves 85A, 85B are respectively provided with the protrusions 82e, 82f of the rotor 82 such that the protrusions 82e, 82f are movable in the circumferential direction in predetermined ranges. As shown in FIGS. 22 and 24, when the cupped member 6 is rotated in the closing direction and the damper body 81 is rotated in a direction of arrow A and the rotor 82 is rotated in a direction of arrow B accompanying the rotation of the cupped member 6, the recesses 82g, 82h are respectively closed by the valves 85A, 85B. As a result, the fluid in the high pressure chamber 83A cannot pass through the recesses 82g, 82h, and therefore, flows into the low pressure chamber 83B via a slight gap S1 between the bottom 81a and the distal end surfaces of the recesses 82g, 82h (see FIG. 26) and a slight gap S2 between the large-diameter portion 82a and the distal end surfaces of the partition wall portions 81e, 81f (see FIG. 28). At this time, the gap S1 between the bottom 81a and the distal end surfaces of the recesses 82g, 82h and the gap S2 between the large-diameter portion 82a and the distal end surfaces of the partition wall portions 81e, 81f act as kinds of orifices that resist against the flow of the fluid. Accordingly, the rotation speed of the damper body 81 in the direction of arrow A and the rotation speed of the rotor 82 in the direction of arrow B are controlled to be at low speeds, thereby the rotation speed of the cupped member 6 in the closing direction being controlled to be at a low speed.

When the cupped member 6 is rotated in the closing direction outside of the engageable range, the damper body 81 is not rotated accompanying the rotation of the outer link 5. Instead, the damper body 81 is rotated together with the rotor 82 due to a frictional resistance between the partition wall portions 81e, 81f and the small-diameter portion 82b, a frictional resistance between the protrusions 82e, 82f and the inner circumferential surface of the damper body 81 and a frictional resistance between the valves 85A, 85B and the inner circumferential surface of the damper body 81. Therefore, the rotary damper 81 does not function as a damper during such time.

When the cupped member 6 is rotated in the opening direction, the damper body 81 is rotated in the direction of arrow B in FIGS. 22 and 23, and the rotor 82 is rotated in the direction of arrow A. During such time, as shown in FIGS. 23 and 25, the valves 85A, 85B do not close entireties of the recesses 82g, 82h, leaving portions of the recesses 82g, 82h open. This allows the fluid in the low pressure chambers 83B, 83B to respectively flow into the high pressure chambers 83A, 83A via the portions of the recesses 82g, 82h that are left open. Here, the portions of the recesses 82g, 82h that are left open have enough flow areas to allow the fluid in the low pressure chambers 83B, 83B to respectively flow into the high pressure chambers 83A, 83A substantially without resistance. Therefore, the damper body 81 and the rotor 82 can be rotated substantially without resistance and the cupped member 6 can be rotated in the opening direction at a high speed.

A rotary damper used in the hinge device of the present invention is not limited to the rotary damper 8 having the features described above. Any rotary damper having other features known in the art may be used as long as the rotary damper can control rotation speeds of the inner link 4 and/or the outer link 5 in the closing direction to be at low speeds.

A strength of a damping effect of the rotary damper 8, i.e., a strength of a damping effect of the rotary damper 8 to control the rotation speeds of the damper body 81 and the rotor 82 to be at low speeds when the cupped member 6 is rotated in the closing direction within the engageable range, can be adjusted by adjusting the position of the damper body 81 with respect to the rotor 82 at an appropriate position between the first position and the second position. In order to achieve this, a position adjustment mechanism having the following features is provided between the side plate 42 of the inner link 4 and the bottom 81a of the damper body 81.

Specifically, as shown in FIG. 7 and FIGS. 14 to 18, a rotatable cam plate 95 and a movable cam plate 96 are disposed between the side plate 42 of the inner link 4 and the bottom 81a of the damper body 81. The rotatable cam plate 95 is disposed on the side plate 42 side and the movable cam plate 96 is disposed on the damper body 81 side.

As particularly shown in FIG. 18, the rotatable cam plate 95 is rotatably contacted with an inner surface of the side plate 42 opposed to the side plate 41. The central shaft J1 is rotatably disposed through the rotatable cam plate 95. An arm 95a is formed in an outer circumferential portion of the rotatable cam plate 95. The arm 95a extends outward in a radial direction of the central shaft J1. An operation tab 95b protruded toward the side plate 42 is formed in a distal end portion of the arm 95a. The operation tab 95b passes through the side plate 42 and further through an operation window 32a (see FIG. 2) formed in the side plate 32 of the hinge body 3 and is protruded outside. Accordingly, the operation tab 95b can be operated from outside the hinge device 1.

As shown in FIG. 29, the operation window 32a is formed as an elongated hole extending in a circular-arc configuration about the central shaft J1. Accordingly, the rotatable cam plate 95 can be rotated by moving the operation tab 95b along the operation window 32a.

By an elasticity of the arm 95a, the operation tab 95b is pressingly contacted with a portion of an inner circumferential surface of the operation window 32a on the large-diameter portion side. A plurality of engagement recesses 32b are formed in the inner circumferential surface of the operation window 32a on the large-diameter portion side. Engagement projections 95c disengageably engaged with the engagement recesses 32b are formed in an outer surface of the operation tab 95b contacted with the inner circumferential surface of the operation window 32a. The engagement projections 95c are engaged with the engagement recesses 32b by an elastic force of the arm 95a, thereby the operation tab 95b being positioned with a force of a predetermined magnitude, thereby the rotational position of the rotatable cam plate 95 being determined. It is to be understood that the engagement projections 95c can be disengaged from the engagement recesses 32b by moving the operation tab 95b in the operation window 32a toward the small-diameter portion against the elastic force of the arm 95a. And the rotatable cam plate 95 can be rotated by moving the operation tab 95b in a longitudinal direction of the operation window 32a while keeping the engagement projections 95c and the engagement recesses 32b disengaged from each other. After that, when the operation tab 95b is made to be freely movable, the operation tab 95b is pressed against the inner circumferential surface of the operation window 32a on the large-diameter portion side by the elastic force of the arm 95a and the engagement projections 95c are engaged with the engagement recesses 32b. Thereby, the rotatable cam plate 95 is maintained at the rotational position.

As shown in FIG. 18, one surface of the movable cam plate 96 is opposed to the rotatable cam plate 95 and the other surface of the movable cam plate 96 is rotatably contacted with the bottom 81a of the damper body 81. The central shaft J1 is rotatably disposed through the movable cam plate 96. The movable cam plate 96 is engaged with the engagement shaft 34, thereby prohibited from being rotated about the central shaft J1. The movable cam plate 96 is movable with respect to the central shaft J1 and the engagement shaft 34 in the longitudinal directions thereof. Accordingly, the movable cam plate 96 is movable toward and away from the rotatable cam plate 95.

As shown in FIG. 7, a plurality of cam surfaces 95d extending in a circumferential direction are formed in a surface of the rotatable cam plate 95 opposed to the movable cam plate 96. A plurality of cam surfaces 96a are formed in a surface of the movable cam plate 96 opposed to the rotatable cam plate 95. The number of the cam surfaces 96a is equal to the number of the cam surfaces 95d. The cam surfaces 95d and the cam surfaces 96a are respectively contacted with each other. The rotatable cam plate 95 and the movable cam plate 96 are not contacted with each other except for at the cam surfaces 95d and the cam surfaces 96a.

When the rotatable cam plate 95 is rotated in one direction, the cam surfaces 95d, 96a contacted with each other moves the movable cam plate 96 away from the rotatable cam plate 95 and moves the damper body 81 from the second position side toward the first position. This causes the gap S1 between the bottom 81a and the protrusions 82e, 82f and the gap S2 between the large-diameter portion 82a and the partition wall portions 81e, 81f to be narrowed, thereby causing a resistance of the fluid flowing through the gaps S1, S2 to be increased. Therefore, the damping effect of the rotary damper 8 is increased.

To the contrary, when the rotatable cam plate 95 is rotated in the other direction, the cam surfaces 95d, 96a allow the movable cam plate 96 to be moved toward the rotatable cam plate 95. This causes the movable cam plate 96 to be moved from the first position side toward the second position because of a pressure of the fluid in the space 83 of the damper body 81. As a result, the gap S1 between the bottom 81a and the protrusions 82e, 82f and the gap 52 between the large-diameter portion 82a and the partition wall portions 81e, 81f are widened, thereby causing the resistance of the fluid flowing through the gaps S1, S2 to be reduced. Therefore, the damping effect of the rotary damper 8 is reduced.

As is clear from the above, the rotatable cam plate 95, the movable cam plate 96 and the fluid filled in the space 83 constitute a position adjustment mechanism that adjusts the position of the damper body 81 with respect to the rotor 82. The position adjustment mechanism is not limited to this, but various modifications can be adopted. For example, a positive cam mechanism may be provided between the rotatable cam plate 95 and the movable cam plate 96 so that the movable cam plate 96 can be moved toward and away from the rotatable cam plate 95 by the rotation of the rotatable cam plate 95. In this case, the fluid in the space 83 is not required for moving the movable cam plate 96.

The rotary damper 8, the rotatable cam plate 95 and the movable cam plate 96 can be built in the hinge body 3 in the following manner. Firstly, the side plates 41, 42 of the inner link 4 are inserted between the side plates 31, 32 of the hinge body 3. Secondly, the rotary damper 8 is inserted between the side plates 41, 42. Then the rotary damper 8 is moved from the side plate 42 side toward the side plate 41 and the protrusions 82c are inserted into the holes 41b. Next, the rotatable cam plate 95 is inserted between the damper body 81 of the rotary damper 8 and the side plate 42 and the operation tab 95b of the rotatable cam plate 95 is inserted into the operation window 32a. Then the movable cam plate 96 is inserted between the rotatable cam plate 95 and the damper body 81. Finally, the central shaft J1 is inserted through the side plate 31, side plate 41, the support hole 82d, the movable cam plate 96, the rotatable cam plate 95, the side plate 42 and the side plate 32.

In the hinge device 1 having the features mentioned above, since the inner link 4 and the outer link 5 are biased by only one torsion coil spring 7, the number of components can be reduced and the number of assembly steps can be reduced compared with a conventional hinge device in which two torsion coil springs are used. Therefore, manufacturing cost of the hinge device 1 can be reduced.

Moreover, since the inner link 4 is biased only at the side plate 41, which is the one side portion thereof and the outer link 5 is biased only at the side plate 52, which is the other side portion thereof, the inner link 4 and the outer link 5 may not be rattled at opposite side portions. Instead, the inner link 4 may be rattled only at the side plate 42 side and the outer link 5 may be rattled only at the side plate 51 side. Therefore, the rattle of the inner link 4 and the outer link 5 can be reduced by half.

FIGS. 30 to 33 show a second embodiment of the present invention. In this embodiment, to transmit the rotation of the outer link 5 to the damper body 81, a second rotation transmission mechanism that is different from the one used in the first embodiment is adopted. Specifically, a protrusion 81g protruded outward in the radial direction of the damper body 81 is formed in the outer circumferential surface of the damper body 81. A guide hole (guide groove) 81h extending in a longitudinal direction of the protrusion 81g is formed in the protrusion 81g. In place of the guide hole 81h, a guide groove extending in the same direction may be formed in the protrusion 81g. A shaft portion 54 is formed in the one end portion of the outer link 5 with a longitudinal direction of the shaft portion 54 oriented in the axial direction of the central shaft J2. The shaft portion 54 is disposed at a location spaced from the axis of the central shaft J2. The shaft portion 54 is disposed in the guide hole 81h such that the shaft portion 54 is rotatable and movable in a longitudinal direction of the guide hole 81h. Accordingly, when the outer link 5 is rotated bout the central shaft J2, the damper body 81 is rotated about the central shaft J1. The guide hole 81h and the shaft portion 54 are arranged in a manner to enable the damper body 81 and the rotor 82 to be rotated in opposite directions. As long as the guide hole 81h can transmit the rotation of the outer link 5 to the damper body 81 in cooperation with the shaft portion 54, it is not required that the longitudinal direction of the guide hole 81h coincides with the longitudinal direction of the protrusion 81g, i.e., radial direction through a center of the damper body 81. Alternatively, the guide hole 81h may be oriented in a direction parallel to the radial direction of the damper body 81 or in a direction orthogonal to the radial direction of the damper body 81. Other features of this embodiment are the same as those of the first embodiment. Therefore, same reference numerals are assigned to the same components and explanations about them are omitted.

A mode of transmission in which the rotation of the outer link 5 is transmitted to the damper body 81 by the guide hole 81h and the shaft portion 54 can be applied for the transmission of the rotation of the outer link 5 to the rotor 82. In this case, a protrusion corresponding to the protrusion 81g may be formed in a portion of the rotor 82 protruded outside from the damper body 81. To transmit the rotation of the inner link 4 to the damper body 81, a mechanism for rotation transmission by fitting of a protrusion and a hole may be provided between the damper body 81 and the side plate 42 of the inner link 4. When a rotary damper is disposed around another shaft other than the central shafts J1, J2, the rotation transmission mechanism by the guide hole 81h and the shaft portion 54 may be provided between the inner link 4 and one of the damper body 81 and the rotor 82 and between the outer link 5 and the other of the damper body 81 and the rotor 82.

FIG. 34 shows a torsion spring 7A that may be used in place of the torsion coil spring 7 in the hinge device 1 according to the present invention. The torsion spring 7A is made of a metal plate. The torsion spring 7A includes a cylindrical portion 74 made by winding the metal plate into a configuration having a generally C-shaped cross-section, a protruded portion (one end portion) 75 disposed in one end portion of the cylindrical portion 74 in an axial direction thereof and a protruded portion (the other end portion) 76 disposed in the other end portion of the cylindrical portion 74. It is to be understood that the protruded portion 75 is abutted against the side plate 41 of the inner link 4 and the protruded portion 76 is abutted against the side plate 52 of the outer link 5.

FIGS. 35 to 38 show a third embodiment of the present invention. In the third embodiment, other mechanisms than those used in the first and second embodiments are adopted as a catch mechanism (first rotation transmission mechanism), a second rotation transmission mechanism and a position adjustment mechanism. In the catch mechanism, a protrusion 41c protruded in the radial direction of the central shaft J1 is formed in a rear end portion of the side plate 41 of the inner link 4. Two protrusions 82i, 82i are disposed in the end surface of the rotor 82 opposed to the side plate 41. The protrusions 82i, 82i are disposed spaced from each other by a predetermined distance in the circumferential direction about the central shaft J1. The protrusion 41c is disposed between the two protrusions 82i, 82i such that the protrusion 41c is non-movable in the circumferential direction of the central shaft J1. By this arrangement, the inner link 4 and the rotor 82 are relatively non-rotatably connected to each other and the rotation of the inner link 4 can be transmitted to the rotor 82.

Now the second rotation transmission mechanism is described. An engagement shaft 55 is disposed in a rear end portion of the outer link 5. The engagement shaft 55 is disposed parallel to the central shaft J2. Opposite end portions of the engagement shaft 55 are supported by the outer link 5. Two protrusions 81g, 81g are disposed in the outer circumferential surface of the damper body 81. The protrusions 81g, 81g are disposed spaced from each other by a predetermined distance in the circumferential direction of the damper body 81. A guide groove 81i is formed between the protrusions 81g, 81g. A middle portion of the engagement shaft 55 is disposed in the guide groove 81i such that the engagement shaft 55 is movable in the radial direction of the damper body 81 and generally non-movable in the circumferential direction of the damper body 81. Accordingly, when the outer link 5 is rotated, the engagement shaft 55 is abutted against one or the other of the two protrusions 81g, 81g depending on the rotational direction of the outer link 5. Thereby, the rotation of the outer link 5 is transmitted to the damper body 81.

The position adjustment mechanism is different from those in the previously described embodiments in the arrangements of the rotatable cam plate 95 and the movable cam plate 96. Specifically, the rotatable cam plate 95 is disposed outside of the side plate 42 of the inner link 4. In other words, the rotatable cam plate 95 is disposed between the side plate 42 and the side plate 32 of the hinge body 3. The movable cam plate 96 is disposed between the side plate 42 and the bottom 81a of the damper body 81. Accordingly, the side plate 42 is disposed between the rotatable cam plate 95 and the movable cam plate 96. Portions of the rotatable cam plate 95 and the movable cam plate 96 are respectively protruded outward from the side plate 42 in the radial direction of the central shaft J1. Cam surfaces (not shown) respectively corresponding to the cam surfaces 95d, 96a are formed in the portions of the rotatable cam plate 95 and the movable cam plate 96 protruded from the side plate 42. It is to be understood that the cam surfaces are contacted with each other. Accordingly, when the rotatable cam plate 95 is operated to be rotated, the movable cam plate 96 is moved in the axial direction of the central shaft J1 and the damper body 81 is moved in the same direction.

The inner link 4, the outer link 5, the rotary damper 8, the rotatable cam plate 95 and the movable cam plate 96 of the hinge device having the position adjustment mechanism as described above can be built between the side plates 31, 32 of the hinge body 3 in the following manner. Firstly, the rotatable cam plate 95 is inserted between the side plates 31, 32 of the hinge body 3. Then, the rotatable cam plate 95 is moved in the axial direction of the central shaft J1. The rotatable cam plate 95 is contacted with the side plate 32 and the operation tab 95b is inserted into the operation window 32a. Next, the one end portions of the side plates 41, 42 of the inner link 4 are inserted between the side plate 31 and the rotatable cam plate 95. After that, the rotary damper 8 is inserted between the side plates 41, 42 and the protrusion 41c is inserted between the protrusions 82i, 82i. At this time, the protrusion 41c can be inserted between the protrusions 82i, 82i from outside in the radial direction of the central shaft J1 since a gap between the protrusions 82i, 82i is open toward outside in the radial direction of the central shaft J1. Accordingly, the rotary damper 8 can be inserted between the side plates 41, 42 simply by being moved in the radial direction of the central shaft J1. After that the movable cam plate 96 is inserted between the rotary damper 8 and the side plate 42. The movable cam plate 96 may be inserted between the side plates 41, 42 before the insertion of the rotary damper 8 between the side plates 41, 42 or may be inserted between the side plates 41, 42 at the same time with the rotary damper 8. Alternatively, the rotary damper 8 and the movable cam plate 96 may be inserted between the side plates 41, 42 before the insertion of the side plates 41, 42 between the side plates 31, 32 (rotatable cam plate 95). Then, the central shaft J1 is inserted through the side plates 31, 32, the side plates 41, 42, the rotary damper 8, the rotatable cam plate 95 and the movable cam plate 96, thereby the building-in being completed. After that, the outer link 5 is inserted between the side plates 31, 32, the engagement shaft 55 is inserted in the guide groove 81i between the protrusions 81g, 81g and the central shaft J2 is inserted through the side plates 31, 32 and the outer link 5. Alternatively, the outer link 5 may be inserted between the side plates 31, 32 before the insertion of the inner link 4 between the side plates 31, 32. In this case, the engagement shaft 55 is relatively inserted into the guide groove 81i between the protrusions 81g, 81g when the rotary damper 8 is inserted between the side plates 41, 42.

In this embodiment, one end portions of the two protrusions 91c, 91d of the cam member 91 are connected to each other, thereby the two protrusions 91c, 91d as a whole being formed in a generally U-shaped configuration. A distance between the protrusions 91c, 91d is slightly greater than a width of the protrusion 72 of the torsion coil spring 7, and the protrusion 72 is movable between the protrusions 91c, 91d through a slight distance in the circumferential direction of the coil portion 71. It is to be understood that alternatively the protrusion 72 may be inserted between the protrusions 91c, 91d such that the protrusion 72 is non-movable in the circumferential direction of the coil portion 71.

Moreover, in this embodiment, the movable cam plate 96 is prevented from rotation by a spacer 92 in place of the engagement shaft 34. For this function, an engagement recess 96b is formed in an outer circumferential surface of the movable cam plate 96. A bottom surface of the engagement recess 96b is a circular arcuate surface about the axis of the support shaft J3. An outer circumferential surface of the spacer 92 is a circular arcuate surface about the axis of the support shaft J3, having a radius of curvature that is equal to a radius of curvature of the circular arcuate surface that constitutes the engagement recess 96b. A portion of the outer circumferential surface of the spacer 92 is disposed in the engagement recess 96b. By this arrangement, the movable cam plate 96 is prevented from being rotated. Moreover, the spacer 92 is not prevented from being rotated by the movable cam plate 96.

FIGS. 39 to 43 show a fourth embodiment of the present invention. In a hinge device 1A of this embodiment, the base plate 21 is fixed to an inner surface of a left side wall of a housing H with a fixing bolt B1. The base plate 21 is provided with the movable plate 22. The position of the movable plate 22 can be adjusted in the vertical direction. After the position adjustment, the movable plate 22 is fixed to the base plate 21 with a fixing bolt B2. In place of the engagement shaft 22b, an engagement recess 22c is formed in the rear end portion of the movable plate 22.

An intermediate member 101 is received in the hinge body 3. The intermediate member 101 is provided with the engagement shaft 34 and the engagement member 36. The engagement member 36 is provided with an engagement shaft 36b in place of the engagement recess 36a. The intermediate member 101 is removably attached to the movable plate 22 by the engagement of the engagement shaft 34 with the engagement recess 22a and the engagement of the engagement shaft 36b with the engagement recess 22c.

The hinge body 3 is not movable in the vertical direction with respect to the intermediate member 101. However, the hinge body 3 is movable in the front-rear direction and the left-right direction with respect to the intermediate member 101. After a position of the hinge body 3 with respect to the intermediate member 101 is adjusted in the front-rear direction, the hinge body 3 is fixed to the intermediate member 101 with a fixing bolt B3.

The adjustment bolt 25 is provided between a front end portion of the connecting plate 33 of the hinge body 3 and a front end portion of the intermediate member 101. When the adjustment bolt 25 is rotated in normal and reverse directions, the position of the front end portion of the hinge body 3 is adjusted in the left-right direction according to the rotation of the adjustment bolt 25. Accordingly, the position of the front end portion of the hinge body 3 can be adjusted in the front-rear, left-right, and vertical directions. By adjusting the position of the front end portion of the hinge body 3, a position of a door D with respect to the housing H in the front-rear, left-right and vertical directions can be adjusted. It is to be understood that the position adjustment mechanisms described in the foregoing embodiments may be adopted or another position adjustment mechanism known in the art may be adopted for the hinge body 3.

The coil portion 71 of the torsion coil spring 7 is disposed around the second central shaft J2. Therefore, the support shaft J3 is not required in the hinge device 1A of this embodiment. Accordingly, the number of components can be reduced and manufacturing cost of the hinge device 1A can be reduced by the amount associated with the provision of the support shaft J3.

The protrusion (one end portion) 72 of the torsion coil spring 7 is directly pressed against the connecting plate 43 of the inner link 4 at the portion of the connecting plate 43 adjacent to the side plate 41 (one side portion) by the biasing force of the torsion coil spring 7. Thereby, the inner link 4 is rotatably biased about the first central shat J1. The protrusion (the other end portion) 73 of the torsion coil spring 7 is directly pressed against the connecting plate 53 of the outer link 5 at the portion of the connecting plate 53 adjacent to the side plate 52 (the other side portion) by the biasing force of the torsion coil spring 7. Thereby, the outer link 5 is rotatably biased about the second central shaft J2. The inner link 4 and the outer link 5 are rotatably biased in the same direction. The inner link 4 and the outer link 5 are rotatably biased by the torsion coil spring 7, and thereby, the door D is rotationally biased. However, it is only when the door D is positioned between a closed position shown in FIG. 40 and a change point position that the door D is rotatably biased by the torsion coil spring 7 via the inner link 4 and the outer link 5. The door D is biased to be rotated toward the closed position. When the door D is positioned between the change point position and an open position shown in FIG. 42, the biasing force of the torsion coil spring 7 does not act on the inner link 4 and the outer link 5, thereby not acting on the door D. Therefore, the door D can be stopped at any positions between the change point position and the open position. Alternatively, the hinge device 1A may be designed such that the biasing force of the torsion coil spring 7 may act on the inner link 4 and the outer link 5 even when the door D is positioned between the change point position and the open position, thereby causing the door D to be rotated to the open position.

FIGS. 44 to 47 show a fifth embodiment of the present invention. In a hinge device 1B of this embodiment, the protrusion (the other end portion) 73 of the torsion coil spring 7 is pressed against the shaft portion (fourth central shaft) 63 at a portion of the shaft portion 63 adjacent to the side plate 52 of the outer link 5. Accordingly, the other side portion of the outer link 5 is rotatably biased by the torsion coil spring 7 via the shaft portion 63. Other features of the hinge device 1B are the same as those of the fourth embodiment.

FIGS. 48 to 50 show a sixth embodiment of the present invention. In a hinge device 1C of this embodiment, the coil portion 71 of the torsion coil spring 7 is disposed around the first central shaft J1. Moreover, the side plate 52 of the outer link 5 is provided with an engagement shaft 102. The engagement shaft 102 is disposed parallel to the second central shaft J2 and extends from the side plate 52 toward the side plate 51. The protrusion 73 of the torsion coil spring 7 is pressed against the engagement shaft 102 at a portion of the engagement shaft 102 adjacent to the side plate 52 by the biasing force of the torsion coil spring 7. As a result, the side plate 52 of the outer link 5 is rotatably biased by the torsion coil spring 7 via the engagement shaft 102. Other features of the hinge device 1C are the same as those of the fourth embodiment.

FIGS. 51 and 52 show a seventh embodiment of the present invention. In this embodiment, an upper inner link (link constituent) 4A and a lower inner link (link constituent) 4B are used in place of the inner link 4. The upper inner link 4A and the lower inner link 4B respectively have configurations corresponding to the side plates 42, 41 if separated from each other, with the connecting plate 43 of the inner link 4 being omitted. The upper inner link 4A and the lower inner link 4B are separated from each other and disposed spaced from each other in the vertical direction. Accordingly, the upper inner link 4A is disposed so as to be contacted with a surface of the side plate 32 of the hinge body 3 facing inside. The lower inner link 4B is disposed so as to be contacted with a surface of the side plate 31 facing inside.

The cam surface 41a is formed in one end portion of the lower inner link 4B (end portion on the first central shaft J1 side). The cam surface 91a of the cam member 91 is pressed against the cam surface 41a by the torsion coil spring 7. Accordingly, the lower inner link 4B is rotationally biased by the torsion coil spring 7 to rotate the door-side mounting member 6. On the other hand, the upper inner link 4A is not rotationally biased by the torsion coil spring 7. The upper inner link 4A is just rotated following the rotation of the door-side mounting member 6.

As shown in FIG. 52, a catch recess 32c is formed in a portion of the inner circumferential surface of the operation window 32a on the large-diameter side. A catch arm 96e formed in the movable cam plate 96 is caught by the catch recess 32c. By this arrangement, the movable cam plate 96 is disposed in the side plate 31 of the hinge body 3 such that the movable cam plate 96 is non-rotatable but movable in the axial direction of the first central shaft J1.

A protrusion 95e protruded in a radial direction of the rotatable cam plate 95 is formed in an outer circumferential surface of the rotatable cam plate 95. A catch protrusion 95f protruded toward the movable cam plate 96 is formed in a surface of the protrusion 95e facing toward the movable cam plate 96. An elongated protrusion 96c extending in a circumferential direction is formed in an outer circumferential surface of the movable cam plate 96. A plurality of engagement recesses 96d are formed in a surface of the elongated protrusion 96c facing toward the rotatable cam plate 95. The engagement recesses 96d are arranged such that when the rotatable cam plate 95 is rotated to a certain position, the catch protrusion 95f fits into one of the engagement recesses 96d. By this arrangement, a rotational position of the rotatable cam plate 95 is determined, thereby a position of the movable cam plate 96 in an axial direction of the rotary damper 8 being determined. In this embodiment, a position of the damper body 81 is fixed to the hinge body 3, and when the position of the movable cam plate 96 is adjusted, a position of the rotor 82 with respect to the damper body 81 is adjusted in the axial direction of the damper body 81, thereby a damping force of the rotary damper 8 being adjusted.

The guide hole 81h is formed in the protrusion 81g in this embodiment as well. However, in this embodiment, the guide hole 81h does not linearly extend in the radial direction of the damper body 81 but has a bent configuration. By this arrangement, the damping force of the rotary damper 8 is changed curvilinearly according to the rotational position of the door-side mounting member 6.

In this embodiment, the upper inner link 4A and the lower inner link 4B are used in place of the inner link 4. The upper inner link 4A may be rattled because it is not biased by the torsion coil spring 7. However, the lower inner link 4B may be hardly rattled because the lower inner link 4B is pressed against the first central shaft J1 by the torsion coil spring 7. Therefore, the rattle of the upper inner link 4A and the lower inner link 4B in totality can be reduced by half.

It is to be understood that the present invention is not limited to the embodiments described above, and various modifications may be adopted without departing from the spirit or scope of the invention.

For example, while the cupped member 6 is rotatably connected to the hinge body 3 by the inner link 4 and the outer link 5 in the embodiments described above, another link may be used between the cupped member 6 and the hinge body 3 as in the known hinge devices.

Moreover, while the inner link 4 is used as the first link and the outer link 5 is used as the second link in the embodiments described above, the inner link 4 may be used as the second link and the outer link 5 may be used as the first link. In such a case, the rotary damper 8 may be disposed in the outer link 5, the rotor 82 may be non-rotatably connected to the outer link 5 and the damper body 81 may be connected to the inner link 4 such that the damper body 81 may be rotated accompanying the rotation of the inner link 4, for example. Moreover, the protrusion 73 may be contacted with the outer link 5 via the cam member 91.

Furthermore, in the embodiments described above, the rotary damper 8 in which the annular space 83 is formed between the inner circumferential surface of the receiving portion 81A of the damper body 81 and the outer circumferential surface of the rotor 82 is adopted as a rotary damper. Alternatively, as disclosed in Japanese Unexamined Patent Application Publication No. 2006-242253 and Japanese Unexamined Patent Application Publication (Translation of PCT International Application Publication) No. 2010-528938, a rotary damper in which a space having a fan-like configuration or a generally half-circular configuration is formed between an inner circumferential surface of a receiving portion of a damper body and an outer circumferential surface of a rotor may be used as a rotary damper, for example.

Moreover, three or more link constituents may be used and each of the link constituents may be disposed spaced from one another in the axial direction of the first central shaft J1.

REFERENCE SINGS LIST

• J1 first central shaft
• J2 second central shaft
• J3 support shaft
• 1 hinge device
• 3 hinge body (housing-side mounting member)
• 4 inner link (first link)
• 4A upper inner link (link constituent)
• 4B lower inner link (link constituent)
• 5 outer link (second link)
• 6 cupped member (door-side mounting member)
• 7 torsion coil spring (torsion spring)
• 7A torsion spring
• 41 side plate
• 41 a cam surface (earn mechanism)
• 42 side plate
• 51 side plate
• 52 side plate
• 62 shaft portion (third central shaft)
• 63 shaft portion (fourth central shaft)
• 72 protrusion (one end portion of the torsion coil spring)
• 73 protrusion (the other end portion of the torsion coil spring)
• 75 protrusion (one end portion of the torsion spring)
• 76 protrusion (the other end portion of the torsion spring)
• 91 a cam surface (cam mechanism)

Claims

1. A hinge device comprising: a housing-side mounting member;a first link having one end portion thereof rotatably supported by the housing-side mounting member via a first central shaft;a second link having one end portion thereof rotatably supported by the housing-side mounting member via a second central shaft;the first central shaft and the second central shaft are parallel to each other;a door-side mounting member, an other end portion of the first link rotatably connected to the door-side mounting member via a third central shaft, an other end portion of the second link rotatably connected to the door-side mounting member via a fourth central shaft;the third central shaft and the fourth central shaft are parallel to the first central shaft and the second central shaft; anda torsion spring rotatably biasing the door-side mounting member,wherein one end portion of the torsion spring is engaged with a side portion of the first link located at an end side in axial directions of the first central shaft, the second central shaft, the third central shaft and the fourth central shaft so that the torsion spring may rotatably bias the door-side mounting member via the first link and the second link; andwherein an other end portion of the torsion spring is engaged with a side portion of the second link located at an other end side in the axial directions of the first central shaft, the second central shaft, the third central shaft and the fourth central shaft.

2. The hinge device according to claim 1, wherein the first link and the second link are rotatably biased by the torsion spring in a same direction.

3. The hinge device according to claim 1, wherein the one end portion of the torsion spring is engaged with the one side portion of the first link via a cam mechanism that may transmit biasing force of the torsion spring to the first link andwherein the other end portion of the torsion spring is directly engaged with an other side portion of the second link.

4. The hinge device according to claim 1, wherein the one end portion of the torsion spring is directly engaged with the one side portion of the first link andwherein the other end portion of the torsion spring is directly engaged with an other side portion of the second link.

5. The hinge device according to claim 1, wherein the one end portion of the torsion spring is directly engaged with the one side portion of the first link andwherein the other end portion of the torsion spring is engaged with an other side portion of the second link via the fourth central shaft.

6. The hinge device according to claim 1, wherein the one end portion of the torsion spring is directly engaged with the one side portion of the first link andwherein the other end portion of the torsion spring is engaged with an other side portion of the second link via an engagement shaft disposed at the other side portion of the second link.

7. The hinge device according to claim 1, wherein a pair of side plates opposed to each other are respectively disposed in one side portion and an other side portion of the one end portion of the first link in the axial direction of the first central shaft,wherein the first central shaft rotatably extends through the pair of side plates, thereby the one end portion of the first link rotatably supported by the housing-side mounting member,wherein a pair of side plates opposed to each other are respectively disposed in one side portion and the other side portion of the one end portion of the second link in the axial direction of the second central shaft,wherein the second central shaft rotatably extends through the pair of side plates, thereby the one end portion of the second link rotatably supported by the housing-side mounting member,wherein the one end portion of the torsion spring is engaged with the side plate of the first link, the side plate is disposed closer to the one end portion of the first link than the side plate in the axial directions of the first central shaft and the second central shaft, andwherein the other end portion of the torsion spring is engaged with the side plate of the second link, the side plate is disposed closer to the other end of the second link than the side plate in the axial directions of the first central shaft and the second central shaft.

8. The hinge device according to claim 1, wherein the torsion spring is a torsion coil spring andwherein a support shaft is disposed in the housing-side mounting member so as to be parallel to the first central shaft and the second central shaft, the support shaft extending through a coil portion of the torsion coil spring, thereby the torsion coil spring is supported by the housing-side mounting member via the support shaft.

9. The hinge device according to claim 1, wherein the first link comprises a plurality of link constituents that are formed separately from each other,wherein the plurality of link constituents are spaced from each other in the axial direction of the first central shaft, andwherein the one end portion of the torsion spring is engaged with the link constituent on the furthermost of one end side of the axial direction of the first central shaft.

10. The hinge device according to claim 2, wherein the one end portion of the torsion spring is engaged with the one side portion of the first link via a cam mechanism that may transmit biasing force of the torsion spring to the first link andwherein the other end portion of the torsion spring is directly engaged with an other side portion of the second link.

11. The hinge device according to claim 2, wherein the one end portion of the torsion spring is directly engaged with the one side portion of the first link andwherein the other end portion of the torsion spring is directly engaged with an other side portion of the second link.

12. The hinge device according to claim 2, wherein the one end portion of the torsion spring is directly engaged with the one side portion of the first link andwherein the other end portion of the torsion spring is engaged with an other side portion of the second link via the fourth central shaft.

13. The hinge device according to claim 2, wherein the one end portion of the torsion spring is directly engaged with the one side portion of the first link andwherein the other end portion of the torsion spring is engaged with an other side portion of the second link via an engagement shaft disposed at the other side portion of the second link.

14. The hinge device according to claim 2, wherein a pair of side plates opposed to each other are respectively disposed in one side portion and an other side portion of the one end portion of the first link in the axial direction of the first central shaft,wherein the first central shaft rotatably extends through the pair of side plates, thereby the one end portion of the first link rotatably supported by the housing-side mounting member,wherein a pair of side plates opposed to each other are respectively disposed in one side portion and the other side portion of the one end portion of the second link in the axial direction of the second central shaft,wherein the second central shaft rotatably extends through the pair of side plates, thereby the one end portion of the second link rotatably supported by the housing-side mounting member,wherein the one end portion of the torsion spring is engaged with the side plate of the first link, the side plate being disposed closer to the one end portion of the first link than the side plate in the axial directions of the first central shaft and the second central shaft, andwherein other end portion of the torsion spring is engaged with the side plate of the second link, the side plate is disposed closer to the other end of the second link than the side plate in the axial directions of the first central shaft and the second central shaft.

15. The hinge device according to claim 3, wherein a pair of side plates opposed to each other are respectively disposed in one side portion and the other side portion of the one end portion of the first link in the axial direction of the first central shaft,wherein the first central shaft rotatably extends through the pair of side plates, thereby the one end portion of the first link rotatably supported by the housing-side mounting member,wherein a pair of side plates opposed to each other are respectively disposed in one side portion and the other side portion of the one end portion of the second link in the axial direction of the second central shaft,wherein the second central shaft rotatably extends through the pair of side plates, thereby the one end portion of the second link rotatably supported by the housing-side mounting member,wherein the one end portion of the torsion spring is engaged with the side plate of the first link, the side plate being disposed closer to the one end portion of the first link than the side plate in the axial directions of the first central shaft and the second central shaft, andwherein the other end portion of the torsion spring is engaged with the side plate of the second link, the side plate is disposed closer to the other end of the second link than the side plate in the axial directions of the first central shaft and the second central shaft.

16. The hinge device according to claim 10, wherein a pair of side plates opposed to each other are respectively disposed in one side portion and the other side portion of the one end portion of the first link in the axial direction of the first central shaft,wherein the first central shaft rotatably extends through the pair of side plates, thereby the one end portion of the first link rotatably supported by the housing-side mounting member,wherein a pair of side plates opposed to each other are respectively disposed in one side portion and the other side portion of the one end portion of the second link in the axial direction of the second central shaft,wherein the second central shaft rotatably extends through the pair of side plates, thereby the one end portion of the second link rotatably supported by the housing-side mounting member,wherein the one end portion of the torsion spring is engaged with the side plate of the first link, the side plate being disposed closer to the one end of the first link than the side plate in the axial directions of the first central shaft and the second central shaft, andwherein the other end portion of the torsion spring is engaged with the side plate of the second link, the side plate is disposed closer to the other end of the second link than the side plate in the axial directions of the first central shaft and the second central shaft.

17. The hinge device according to claim 2, wherein the torsion spring is a torsion coil spring andwherein a support shaft is disposed in the housing-side mounting member so as to be parallel to the first central shaft and the second central shaft, the support shaft extending through a coil portion of the torsion coil spring, thereby the torsion coil spring is supported by the housing-side mounting member via the support shaft.

18. The hinge device according to claim 2, wherein the first link comprises a plurality of link constituents that are formed separately from each other,wherein the plurality of link constituents are spaced from each other in the axial direction of the first central shaft, andwherein the one end portion of the torsion spring is engaged with the link constituent that is located on the most one end side in the axial direction of the first central shaft.