This invention relates to a vibration damping device disposed between components that should be linked in a vibration-damping manner.
Conventionally, there has been known a vibration damping device having a structure wherein a first mounting member and a second mounting member that are disposed to be mutually opposed are connected by a main rubber elastic body, as a kind of vibration damping apparatus disposed between components that should be linked in a vibration-damping manner. In this vibration damping device, as Japanese Unexamined Patent Publication No. JP-A-2005-240926 (Patent Document 1) discloses for example, flat-plate-shaped opposition surfaces provided at both the first and second mounting members are disposed to be mutually opposed and elastically connected to each other by the main rubber elastic body interposed between them.
In the vibration damping device of this structure, the required spring characteristics can be obtained by adjusting the distance in between and the angle with respect to the pair of opposition surfaces between which the main rubber elastic body is disposed. Meanwhile, the durability of the main rubber elastic body can be improved by greatly keeping the free length of the main rubber elastic body.
However, the free length of the main rubber elastic body is determined by the distance between the pair of opposition surfaces. Therefore, when the distance between the opposition surfaces is limited because of the required spring characteristics, it may be impossible to keep an enough free length to ensure the durability of the main rubber elastic body.
Patent Document 1: JP-A-2005-240926
The present invention was established in view of the above background, and one object of the present invention to provide a vibration damping device of novel structure which is able to realize both obtainment of the required spring characteristics and improvement of the durability of the main rubber elastic body.
The modes of this invention that were established in order to solve that problem are described hereinafter. Furthermore, the elements used in each mode indicated below are, as much as possible, adoptable in desired combinations.
A first mode of the present invention provides a vibration damping device for linking components in a vibration-damping manner comprising: a first mounting member configured to be mounted on one of the components; a second mounting member configured to be mounted on an other of the components; at least one first side opposition surface provided in the first mounting member; at least one second side opposition surface provided in the second mounting member and opposed to the first side opposition surface with a gap in between; at least one main rubber elastic body being disposed between the first side opposition surface and the second side opposition surface to elastically connect them; a protruding part provided at the first side opposition surface so as to protrude toward the second side opposition surface with a protrusion dimension with which the protruding part does not reach the second side opposition surface, in a section located peripherally inside an outer peripheral edge of the main rubber elastic body, the protruding part having an outer face without a break and being buried in the main rubber elastic body; and a recessed part provided at the second side opposition surface in opposition to the protruding part while being recessed to a distant side from the protruding part and opening in the second side opposition surface, the recessed part being filled with the main rubber elastic body.
According to the present mode, in the area between the opposed faces of the first side opposition surface and the second side opposition surface elastically connected by the main rubber elastic body, the protruding part is provided at the first side opposition surface. The protruding part protrudes toward the second side opposition surface with the protrusion dimension with which the protruding part does not reach the second side opposition surface and it is buried in the main rubber elastic body, in the section located peripherally inside the outer peripheral edge of the main rubber elastic body. On the other hand, at the second side opposition surface, the recessed part is provided opening in the second side opposition surface, in opposition to the protruding part. The recessed part is recessed to the distant side from the protruding part and filled with the main rubber elastic body. This makes it possible to freely set the spring characteristics of the vibration damping device, by adjusting the separation distance between the protruding part and the second side opposition surface in the opposition direction for the first side opposition surface and the second side opposition surface. Meanwhile, for the outer peripheral edge of the main rubber elastic body, the distance between the opposed faces of the first side opposition surface and the second side opposition surface is made larger, since the protruding part is disposed between the first side opposition surface and the second side opposition surface. Therefore, the free length of the surface of the main rubber elastic body can be largely ensured, thereby enabling secure improvement in the durability of the main rubber elastic body, and hence that of the vibration damping device.
Besides, the protruding part buried in the main rubber elastic body has an outer face without a break, whereby the bonded area of the main rubber elastic body on the protruding part can increase, and thus the durability of the main rubber elastic body can further improve. Moreover, the recessed part, which is recessed to the distant side from the protruding part, is provided in opposition to the protruding part. Therefore, it is possible to sufficiently keep the separation distance between the tip part of the protruding part and the bottom face of the recessed part, thereby making it possible to improve the durability of the main rubber elastic body all the more for the increase in the rubber volume. In this way, according to the vibration damping device structured following the present mode, it is possible to advantageously realize securement of the required spring characteristics and improvement of the durability.
A second mode of this invention provides the vibration damping device according to the first mode, wherein, in an opposition direction for the first side opposition surface and the second side opposition surface, a minimum value of a thickness dimension of the main rubber elastic body is equal to or larger than 70% of a maximum value of the thickness dimension of the main rubber elastic body.
The present mode employs the protruding part and the recessed part recessed to the distant side from the protruding part that are disposed in opposition to each other such that the minimum value of the thickness dimension of the main rubber elastic body is equal to or larger than 70% of the maximum value of that, in the opposition direction for the first side opposition surface and the second side opposition surface. Formation of the protruding part may cause the thickness of the main rubber elastic body to locally thin between the first and second side opposition surfaces, and thus lead to deterioration of the durability. This configuration can favorably avoid this risk, whereby the durability can improve stably.
A third mode of this invention provides the vibration damping device according to the second mode, wherein the thickness dimension in the opposition direction between the first side opposition surface and the second side opposition surface at a peripheral edge of the main rubber elastic body is made substantially equal to the thickness dimension in the opposition direction between a protruding tip face of the protruding part and a bottom face of the recessed part at a central part of the main rubber elastic body.
According to the present mode, the thickness dimension in the opposition direction at the peripheral edge of the main rubber elastic body is made substantially equal to the thickness dimension in the opposition direction at the central part of the main rubber elastic body. This configuration can more advantageously avoid the durability deterioration by the main rubber elastic body thinning locally between the first and second side opposition surfaces due to the protruding part, whereby the durability can improve more stably.
A fourth mode of this invention provides the vibration damping device according to any one of the first to third modes, wherein each of the outer face of the protruding part buried in the main rubber elastic body and an inner face of the recessed part filled with the main rubber elastic body is constituted by a curved face without an edge.
According to the present mode, each of the outer face of the protruding part and the inner face of the recessed part is constituted by a curved face without an edge, whereby local stress concentration in relation to the main rubber elastic body is prevented, and the durability can be further improved.
A fifth mode of the present invention provides the vibration damping device according to any one of the first to fourth modes, wherein, as viewed in an opposition direction for the first side opposition surface and the second side opposition surface, a peripheral rim of a proximal end part of the protruding part is positioned peripherally inside an opening peripheral edge of the recessed part, and a width dimension of the proximal end part of the protruding part in a cross section orthogonal to the opposition direction is set equal to or larger than 50% of a width dimension of the opening peripheral edge of the recessed part.
With respect to the present mode, when viewed in the opposition direction for the first side opposition surface and the second side opposition surface, the peripheral rim of the proximal end part of the protruding part is positioned peripherally inside the opening peripheral edge of the recessed part. This avoids any part of the main rubber elastic body from being clamped directly between the proximal end part of the protruding part and the second side opposition surface in the opposition direction. Thus, the durability deterioration due to the protruding part is favorably prevented. Furthermore, the width dimension of the proximal end part of the protruding part is set equal to or larger than 50% of the width dimension of the opening peripheral edge of the recessed part. This makes it possible to ensure the spring characteristics of the vibration damping device set by the separation distance between the protruding part and the second side opposition surface in the opposition direction for the first side opposition surface and the second side opposition surface.
A sixth mode of this invention provides the vibration damping device according to any one of the first to fifth modes, wherein each of the first mounting member and the second mounting member has an elongated plate shape, and the first mounting member is disposed above the second mounting member so as to be opposed to the second mounting member with the gap in between, a pair of first inclination plate parts are provided at both end portions in a longitudinal direction of the first mounting member so as to be each inclined relative to a middle portion in the longitudinal direction of the first mounting member with respect to a plate thickness direction of the middle portion, a pair of second inclination plate parts are provided at both end portions in the longitudinal direction of the second mounting member so as to be each inclined to the same side of the plate thickness direction as the first inclination plate parts are inclined, the at least one first side opposition surface comprises a pair of first side opposition surfaces while the at least one second side opposition surface comprises a pair of second side opposition surfaces, and opposed faces of the pair of first inclination plate parts and the pair of second inclination plate parts are the pair of first side opposition surfaces and the pair of second side opposition surfaces, and the at least one main rubber elastic body comprises a pair of main rubber elastic bodies, and the pair of main rubber elastic bodies elastically connect the pair of first side opposition surfaces and the pair of second side opposition surfaces to each other, and a central portion of each of the second inclination plate parts is pushed out to a distant side from a corresponding one of the first inclination plate parts in opposition thereto so as to form the recessed part in each of the second side opposition surfaces.
According to the present mode, the main rubber elastic bodies are disposed between the opposed faces of the pair of first inclination plate parts and the pair of second inclination plate parts provided at the both end portions in the longitudinal direction of the first mounting member and the second mounting member, which have an elongated plate shape (between the first side opposition surfaces and the second side opposition surfaces). Therefore, by adjusting the inclination angle for the first inclination plate parts and the second inclination plate parts, it is possible to adjust the ratio between the spring in the longitudinal direction and the spring in the opposition direction for the first mounting member and the second mounting member. Here, the protruding parts and the recessed parts are provided respectively at the first inclination plate parts and the second inclination plate parts, whereby the central portion of each second inclination plate part is largely pushed out to the outside. However, each second inclination plate part is inclined relative to the middle portion in the longitudinal direction of the second mounting member, so that it is possible to smartly accommodate the recessed parts protruding outward in the void spaces made by the inclination. Thus, it is possible to improve the durability without enlargement of the disposition space.
According to the present invention, in the area between the opposed faces of the first side opposition surface and the second side opposition surface elastically connected by the main rubber elastic body, the protruding part is provided in the first side opposition surface, while protruding with the protrusion dimension with which the protruding part does not reach the second side opposition surface and being buried in the main rubber elastic body. On the other hand, the recessed part is provided in the second side opposition surface while opening in the second side opposition surface and being filled with the main rubber elastic body. Consequently, the spring characteristics of the vibration damping device may be freely set by adjusting the separation distance between the protruding part and the second side opposition surface. Meanwhile, in the outer peripheral edge of the main rubber elastic body, the distance between the opposed faces of the first side opposition surface and the second side opposition surface is made large, because of the disposition of the protruding part. This makes it possible to largely ensure the free length of the surface of the main rubber elastic body, and thus securely improve the durability of the main rubber elastic body and hence that of the vibration damping device. In addition, it is possible to increase the bonded area of the main rubber elastic body on the protruding part, whereby it is possible to further improve the durability of the main rubber elastic body. Moreover, since the recessed part is provided, it is also possible to sufficiently keep the separation distance between the tip part of the protruding part and the bottom face of the recessed part, and thus further improve the durability of the main rubber elastic body by the increase of the rubber volume. Therefore, it is possible to advantageously realize both securement of the required spring characteristics and improvement of the durability.
Embodiments of the present invention will be described hereinafter in reference to the drawings.
The first mounting member 12 has a roughly elongated flat plate shape as a whole. For example, the first mounting member 12 is formed with a plate material of metal such as iron and aluminum alloy using a known processing technique like press working or drawing, or with a synthetic resin material using a known molding technique like injection molding. Also, as
With the opposite sides in the longitudinal direction of the contact plate part 22, a pair of first inclination plate parts 26, 26 are integrally formed. More specifically, each first inclination plate part 26 has a roughly flat plate shape extending out from each side of the longitudinal direction of the contact plate part 22 to the corresponding outside in the longitudinal direction obliquely to the upper side. The pair of left and right first inclination plate parts 26, 26 constitute the both end portions in the longitudinal direction of the first mounting member 12. In short, the pair of first inclination plate parts 26, 26 are provided at the both end portions in the longitudinal direction of the first mounting member 12 so that they are each inclined relative to the contact plate part 22 formed at the middle portion in the longitudinal direction with respect to the plate thickness direction of the contact plate part 22. Here, the lower faces of the pair of first inclination plate parts 26, 26 constitute the pair of first side opposition surfaces 16, 16, which are opposed to a pair of second inclination plate parts 44, 44 described later.
At the substantially central portion of each first side opposition surface 16 in the pair of left and right first inclination plate parts 26, 26, a protruding part 28 is formed in a generally truncated quadrangular pyramid shape that is convex obliquely outward and downward. More specifically, as
Moreover, at the outsides in the longitudinal direction of the pair of first inclination plate parts 26, 26, mounting pieces 32 are formed integrally with the first inclination plate parts 26, 26. More specifically, the mounting pieces 32 extend out from the upper ends of the pair of first inclination plate parts 26, 26 to the outsides, as slanting in a substantially doglegged shape in the front views, as
The whole second mounting member 14 has a generally elongated flat plate shape, as well as the first mounting member 12. For example, the second mounting member 14 is formed using a metal plate material of iron, aluminum alloy, or the like, or a synthetic resin material, by a known processing or molding technique. As
With the opposite sides in the longitudinal direction of the support plate part 36, a pair of second inclination plate parts 44, 44 are integrally formed. More specifically, each second inclination plate part 44 has a roughly flat plate shape extending out from each side in the longitudinal direction of the support plate part 36 to the corresponding outside in the longitudinal direction obliquely to the upper side. The pair of left and right second inclination plate parts 44, 44 constitute the both end portions in the longitudinal direction of the second mounting member 14. In short, the pair of second inclination plate parts 44, 44 are provided at the both end portions in the longitudinal direction of the second mounting member 14 so that they are each inclined relative to the support plate part 36 formed at the middle portion in the longitudinal direction to the same side of the plate thickness direction as the first inclination plate parts 26. Here, the upper faces of the pair of second inclination plate parts 44, 44 constitute the pair of second side opposition surfaces 18, 18, which are opposed to the pair of first inclination plate parts 26, 26.
In each second side opposition surface 18 of the pair of left and right second inclination plate parts 44, 44, a recessed part 46 is formed at about the central portion thereof, with a generally rectangular cross-sectional shape. Specifically, the recessed part 46 is formed by the roughly central portion of the second side opposition surface 18 being pushed out, to the distant side from the corresponding first inclination plate part 26 in opposition thereto. That is, the recessed part 46 is provided at the second side opposition surface 18, opening in the second side opposition surface 18 of the second inclination plate part 44. The recessed part 46 is opposed to the protruding part 28 provided at the first side opposition surface 16 of the first inclination plate part 26, and recessed to the distant side from the protruding part 28. As shown in
As
As
Next, the fixation member 54 is attached to the lower face of the support plate part 36 of the second mounting member 14. More specifically, the fixation member 54 includes a fixation part 64 extending in the longitudinal direction in a gutter shape and opening to the sides of the longitudinal direction and the upper side, which has through holes 66 provided through two locations of its bottom wall mutually spaced away in the longitudinal direction, and press-fit pins 68 press-fitted through the through holes 66. This fixation member 54 is formed using a metal plate material of iron, aluminum alloy, or the like, or a synthetic resin material, by a known processing or molding technique, for example. The fixation member 54 with the press-fit pins 68 press-fitted through the through holes 66 of the fixation part 64 is attached to the lower face of the support plate part 36 of the second mounting member 14, by a known adhesion technique such as welding.
Finally, using a not-shown mold for molding, vulcanization molding is performed, with a prescribed rubber material injected into the cavity via an injection hole of the mold for molding. By so doing, the main rubber elastic bodies 20 and a rubber stopper part 71 are formed (see
For example, as
As
Besides, as viewed in the opposition direction for the first side opposition surface 16 of the first inclination plate part 26 and the second side opposition surface 18 of the second inclination plate part 44, the peripheral rim of the proximal end part of the protruding part 28 is positioned peripherally inside the opening peripheral edge of the recessed part 46 (W3<W1 in
As
Additionally, the rubber stopper part 71 is formed integrally with the main rubber elastic body 20, whereby the stopper member 52 is constituted. This rubber stopper part 71 covers the opening peripheral edge of the insertion hole 24 of the first mounting member 12 from above and below, and inside. Meanwhile, the rubber stopper part 71 is disposed as separated from the axis-perpendicular stopper member 56 of the stopper member 52 with a space 72 in the longitudinal direction. Thus, when the first mounting member 12 undergoes excessive displacement in the up-down direction relative to the second mounting member 14 due to a step of the road face etc., the rubber stopper part 71 provided in the contact plate part 22 of the first mounting member 12 gets into contact with the upper stopper member 58. This makes it possible to prevent the excessive displacement of the first mounting member 12 in the up-down direction relative to the second mounting member 14, and reduce the impact and the resultant noise in relation to direct contact between the first mounting member 12 and the upper stopper member 58. Also, when the first mounting member 12 undergoes excessive displacement in the longitudinal direction relative to the second mounting member 14 due to sudden braking, an impact, or the like, the rubber stopper part 71 provided in the contact plate part 22 of the first mounting member 12 gets into contact with the axis-perpendicular stopper member 56. This makes it possible to prevent the excessive displacement of the first mounting member 12 in the longitudinal direction relative to the second mounting member 14, and reduce the impact and the resultant noise in relation to direct contact between the first mounting member 12 and the axis-perpendicular stopper member 56. Consequently, in the vibration damping device 10 of this embodiment, the stopper function for avoiding the excessive displacement thereof is smoothly performed. Additionally, excessive elastic deformation of the main rubber elastic body 20 is prevented, whereby the durability of the main rubber elastic body 20 improves. The rubber stopper part 71 has a substantially annular shape as a whole, and, as
As
According to the vibration damping device 10 of this embodiment constructed in this way, the both end portions of the first mounting member 12 and the second mounting member 14 are elastically connected by the pair of main rubber elastic bodies 20, 20 disposed between the first side opposition surfaces 16 and the second side opposition surfaces 18. At about the central portion of each first side opposition surface 16, the protruding part 28 is provided. The protruding part 28 protrudes toward the second side opposition surface 18 of the second inclination plate part 44 while being buried in the main rubber elastic body 20, in the section located peripherally inside the outer peripheral edge of the main rubber elastic body 20 (the section shown by W3 in
The protruding part 28 buried in the main rubber elastic body 20 includes the outer face 30 constituted by a smooth curved face without a break or an edge. This enables increase of the bonded area of the main rubber elastic body 20 on the protruding part 28, thereby enabling further improvement in the durability of the main rubber elastic body 20. Additionally, the inner face 48 of the recessed part 46 filled with the main rubber elastic body 20 is also constituted by a smooth curved face without a break or an edge, across its entire face. This prevents local stress concentration on the main rubber elastic body 20 due to the recessed part 46 as well as the protruding part 28, whereby the durability of the main rubber elastic body 20 can further improve. Moreover, the recessed part 46 is provided to be opposed to the protruding part 28 and recessed to the distant side from the protruding part 28. Consequently, the separation distance between the protruding tip face 69 of the protruding part 28 and the bottom face 70 of the recessed part 46 can be sufficiently kept, and the increase of the rubber volume allows further improvement in the durability of the main rubber elastic body 20. In this way, according to the vibration damping device 10 of this embodiment, it is possible to favorably realize both securement of the required spring characteristics and the improvement of the durability.
In the vibration damping device 10 of the present embodiment, the main rubber elastic body 20 is disposed for each area between the pair of first side opposition surfaces 16, 16 and the pair of second side opposition surfaces 18, 18, which are the opposed faces of the pair of first inclination plate parts 26, 26 and the pair of second inclination plate parts 44, 44. Consequently, the pairs of opposed faces are elastically connected to one another by the pair of main rubber elastic bodies 20, 20. This configuration allows adjustment of the ratio between the spring in the length direction and the spring in the opposition direction for the first mounting member 12 and the second mounting member 14, by adjusting the inclination angle for the first inclination plate parts 26 and the second inclination plate parts 44. By providing the protruding parts 28 and the recessed parts 46, the central portion of each second inclination plate part 44 is largely pushed out to the outside. However, the recessed parts 46 protruding outward are smartly accommodated in the void spaces made by the aforesaid inclination angle, so that it is possible to improve the durability without enlargement of the disposition space.
The embodiments of this invention have been described above, but the present invention is not limited by the specific descriptions of the embodiments. For example, in the aforementioned embodiment, the protruding part 28 is formed by using a known means like drawing on the first inclination plate part 26 of the first mounting member 12, integrally with the first inclination plate part 26. However, it is also possible to form separately the protruding part and fix it to the first inclination plate part 26 by a known means such as welding, like a protruding part 84 of a vibration damping device 82 serving as a second embodiment shown in
In the first embodiment, the protruding part 28 is formed by using a known means like drawing on the first inclination plate part 26 of the first mounting member 12. Alternatively, it is possible to integrally form the protruding part using a known technique such as die casting of aluminum and injection molding of synthetic resin, like a protruding part 88 of a vibration damping device 86 serving as a third embodiment shown in
In the first embodiment, the protruding part 28 has a roughly truncated quadrangular pyramid shape that is convex obliquely downward and outward. For example, as
For the first to third embodiments, the first side opposition surface 16 and the second side opposition surface 18 are disposed in opposition to each other as parallel, but they may be disposed in opposition as inclined relative to each other. Moreover, for the first to third embodiments, the first side opposition surfaces 16, the second side opposition surfaces 18, and the main rubber elastic bodies 20 connecting them are provided at two locations. However, this invention will do as long as they are provided at at least one location in the vibration damping devices 10, 82, 86, 98, and they may be provided at three or more locations. Furthermore, the first inclination plate parts 26 and the second inclination plate parts 44, which are opposed, are not limited to the inclination plate parts bent upward like examples. In other words, the first inclination plate parts 26 and the second inclination plate parts 44 may be bent downward, and this invention can also employ the inclination plate parts directed to any advantageous direction depending on the disposition space.