This application is based on and incorporates herein by reference Japanese patent application No. 2006-316548 filed on Nov. 24, 2006.
The present invention relates to a fluid pressure control device having a solenoid valve for opening and closing a fluid channel, and a board on which an electronic component is arranged. In particular, the present invention is suitable for a fluid pressure control device for a vehicle brake system.
The board 5 has the electronic components arranged thereon. An end of a connector terminal 6 is connected to the board 5. A plurality of mounting holes are formed at the board 5. The case 3 has a solenoid housing 32 accommodating the solenoid 21, a connector housing 33 accommodating a the other end of the connector terminal 6, and a connection portion 34 through which the solenoid housing 32 are connected to the connector housing 33. A plurality of board-holding units 36 and 37 are also formed at the case 3 and inserted and fitted to the mounting holes of the board 5 so as to fix the board 5. The board-holding units 36 and 37 are respectively provided at the connection portion 34 and the solenoid housing 32 (for example, see Japanese Unexamined Patent Application Publication No. 2002-368452).
However, since the fluid pressure control device for the vehicle brake system is generally mounted in an engine room of a vehicle, the resin case 3 may be deformed by heat generated at an engine. In particular, the connector housing 33 may noticeably warp because the connector housing 33 extends from the solenoid housing 32 in an overhanging manner.
More specifically, the case 3 may be deformed such that the connector housing 33 turns around an axis D of the connection portion 34 with respect to the solenoid housing 32. Accordingly, a solder bonding portion 7 between the connector terminal 6 and the board 5 may be displaced in an F direction.
A component in an x direction of the displacement in the F direction is restricted by the board-holding unit 37 provided at the connection portion 34. Another component in a y direction of the displacement causes a frictional resistance between the board-holding unit 37 provided at the connection portion 34 and the board 5. As a result, stresses are generated at the solder bonding portion 7 in both the x and y directions, thereby making solder cracking more likely to occur.
It is therefore an object of the present invention to reduce a stress generated at a bonding portion between a connector terminal and a board.
In an aspect of the present invention, a fluid pressure control device includes a body having a fluid channel, a solenoid valve having a solenoid exposed to the outside of the body. The solenoid valve is for opening and closing the fluid channel. The fluid pressure control device also includes a board and a resin case. An electronic component is arranged on the board, and a first end of a connector terminal is connected to the board. The board is attached to the resin case, and the case is fixed to the body. The case includes: a connector housing accommodating a second end of the connector terminal; a solenoid housing aligned with the connector housing in a direction parallel to the board and accommodating the solenoid; a connection portion integrally formed with the housings, the connection portion through which the housings are connected to each other, the connection portion and having a smaller external dimension (or thickness) in a direction orthogonal to the board than those of the housings; and a plurality of board-holding units which are inserted and fitted to a plurality of mounting holes formed at the board, so that the board is attached to the case. The board-holding units include a connector side board-holding unit provided at a position on the connector housing side with respect to the connection portion, and a solenoid side board-holding unit provided at a position on the solenoid housing side with respect to the connection portion.
Since a bonding portion between the connector terminal and the board is located near the connector side board-holding unit, the bonding portion is displaced with the connector side board-holding unit when the case is deformed by a heat load. Therefore, no relative displacement is generated in this occasion between the bonding portion and the connector side board-holding unit. Therefore, a resistance against the motion of the bonding portion during the deformation of the case can be reduced, and a stress generated at the bonding portion can be reduced.
A part of the solenoid side board-holding unit to be inserted and fitted to a corresponding one of the mounting holes may be elastically deformable toward the center of the mounting hole.
When the case is deformed by a heat load, the board is biased to rotate around the solenoid side board-holding unit, which serves as a fulcrum. The above configuration makes the rotation of the board easier, since the part of the solenoid side board-holding unit to be inserted and fitted to the mounting hole may be elastically deformable toward the center of the mounting hole. Accordingly, the stress generated at the board and the bonding portion can be reduced.
In addition, because of a reaction force against the elastic deformation, the outer periphery of the solenoid side board-holding unit can be firmly attached to the periphery of the solenoid side mounting hole easily. As a result, positioning of the board in a direction parallel to the board can be facilitated when the board is assembled to the case.
The solenoid side board-holding unit may be divided into a plurality of pieces by a slit extending orthogonally to the board.
With this configuration, the board can easily rotate along with the thermal deformation of the case since the elastic deformation of the solenoid side board-holding unit is easily achieved. Therefore, the resistance force against the motion of the bonding portion during the deformation of the case can be further reduced, and the stress generated at the board and the bonding portion can be further reduced.
The solenoid housing, the connection portion, and the connector housing, may be aligned in a reference direction. In this situation, the solenoid side board-holding unit may be disposed at a position in the solenoid housing wherein the position is farther from the connector housing than the center of the solenoid housing in the reference direction is.
With this configuration, the distance between the connector side board-holding unit and the solenoid board holing unit becomes large, that is, the radius of the rotation of the board during the case deformation becomes large. Therefore, the angle of the rotation of the board can be reduced, and accordingly the resistance force against the motion of the bonding portion during the deformation is further reduced. As a result, the stress generated at the bonding portion is further reduced.
A mounting-hole distance may be smaller than a holding-unit distance with the following four definitions.
With this configuration, the board-holding units are partially press-fitted to the mounting holes. Therefore, the board is reliably fixed to the case when the board-holding units are inserted and fitted to the mounting holes.
The connector side board-holding unit may be press-fitted to a corresponding one of the mounting hole.
With this configuration, the board is reliably fixed to the case when the connector side board-holding unit is inserted and fitted to the mounting hole.
The connector side board-holding unit may be divided into a plurality of pieces by a slit extending orthogonally to the board.
The only one connector side board-holding unit may be provided. In other words, the connector side board-holding unit may be the only member of the board-holding units provided at a position on the connector housing side with respect to the connection portion.
With this configuration as compared with, for example, a case where a plurality of the connector side board-holding units are provided, the space for arranging the connector terminal can be easily obtained.
Otherwise, a plurality of the connector side board-holding units may be provided. In other words, the holding units may include a plurality of units provided at positions on the connector housing side of the connection portion, wherein the connector side board-holding unit is a member of the plurality of units.
With this configuration, as compared with, for example a case where the only one connector side board-holding unit is provided, the inclination of the board with respect to the case during assembling can be reduced.
The only one solenoid side board-holding unit may be provided. In other words, solenoid side board-holding unit may the only member of the board-holding units provided at a position on the solenoid housing side of the connection portion. In this situation, the solenoid side board-holding unit may have a convex portion which prevents the solenoid side board-holding unit from slipping out of a corresponding one of the mounting holes of the board.
With this configuration, the only one solenoid side board-holding unit having the protrusion is provided. Therefore as compared with, for example, a case where a plurality of the solenoid side board-holding units are provided, a restriction force against the rotation of the board caused by the protrusion during the deformation becomes small. As a result, the resistance force against the motion of the board during the deformation is reduced, and the stress generated at the board and the bonding portion can be reduced.
The above-described fluid pressure control device may be mounted on a vehicle, and brake fluid may flow through the fluid channel.
The invention, together with additional objective, features and advantages thereof, will be best understood from the following description, the appended claims and the accompanying drawings. In the drawings:
A first embodiment of the present invention is described below. The fluid pressure control device of this embodiment is used for a vehicle brake system that controls a braking force of a vehicle by controlling a brake fluid-pressure. Note that a vertical direction in
As shown in
Solenoids 21 of the solenoid valves 2 are fixed to a side surface of the body 1 by calking or the like. The solenoids 21 are exposed to the outside of the body 1. A resin case 3 is fixed to the body 1 using a screw (not shown) to cover the solenoid 21.
A coil wire (not shown) of each solenoid 21 is soldered to a solenoid terminal 22. The solenoid terminal 22 penetrates through a terminal hole 31 of the case 3 and extends to a below-described board housing chamber. A sealing member (not shown) is applied between the solenoid terminal 22 and the terminal hole 31 for sealing. In particular, for example, a flexible sealing member, such as silicon, is used to allow the solenoid terminal 22 to be easily displaced. The solenoid terminal 22 has a clinched part 221 which is bent into a crank-like shape so that the solenoid terminal 22 can be elastically deformed easily. The clinched part 221 is located in a below-described solenoid housing.
A resin cover 4 is bonded to the case 3 by welding or the like on the side of the case 3 opposite to the body 1. The case 3 and the cover 4 define a board housing chamber 41. A plate-like board 5 is accommodated in the board housing chamber 41. The board 5 has electronic components (not shown) on its surface. First ends of a plurality of connector terminals 6 which are formed at the case 3 by insert molding are soldered to the board 5, and also, the solenoid terminal 22 is soldered to the board 5.
The case 3 has a substantially rectangular parallelepiped solenoid housing 32 providing a space for accommodating the solenoids 21, a substantially rectangular parallelepiped connector housing 33 providing a space for accommodating second ends of the connector terminals 6, and a plate-like connection portion 34 through which the solenoid housing 32 is connected to the connector housing 33. The housings 32 and 33, and the connection portion 34 are integrally formed.
The housings 32 and 33, and the connection portion 34 are aligned in a direction (hereinafter referred to as a plate-face direction) parallel to the board 5. An external dimension of the connection portion 34 in a direction orthogonal to the plate-face direction of the board 5 is smaller than external dimensions of the housings 32 and 33 in the direction orthogonal to the plate-face-direction of the board 5.
In the case 3, a connector side board-holding unit 35 protruding toward the board 5 is formed at a position on the connector housing 33 side with respect to the connection portion 34, and two solenoid side board-holding units 36 protruding toward the board 5 are formed at positions on the solenoid housing 32 side with respect to the connection portion 34.
Hereinafter, a reference direction is defined to be an alignment direction of the solenoid housing 32, connection portion 34 and connector housing 33 (in this embodiment, a horizontal direction of
In addition, the two solenoid side board-holding units 36 are arranged away from each other in a direction orthogonal to the reference direction Z (in this embodiment, the vertical direction of
As shown in
In addition, ones of the hole forming portions corresponding to the connector side mounting hole 51, a first solenoid side mounting hole 52a, and a second solenoid side mounting hole 52a are respectively referred to as a connector hole forming portion, a first solenoid hole forming portion, and a second solenoid hole forming portion.
As shown in
As shown in
The insertion part 362 has a columnar shape at a portion near the supporting part 361, and has a shape of a truncated cone at a portion near a tip end thereof. The outer diameter of the columnar portion of the insertion part 362 is smaller than the diameter of the solenoid side mounting hole 52. The outer diameter of the truncated-cone portion at the tip end of the insertion part 362 (i.e. a minimum outer diameter) is smaller than the diameter of the solenoid side mounting hole 52. A convex portion 362a is provided at the truncated-cone portion of the insertion part 362 at a position near the supporting part 361. The outer diameter of the convex portion 362a is the largest in the truncated-cone portion, and is larger than the diameter of the solenoid side mounting hole 52. The insertion part 362 is divided into two pieces by a slit 363 extending orthogonal to the board 5. Because of this, the insertion part 362 is easily elastically deformable toward the center of the solenoid side mounting hole 52.
Herein, as shown in
The mounting-hole distance H is smaller than the holding-unit distance L. As described above, in the case where the mounting-hole distance H is smaller than the holding-unit distance L, a portion of the connector side board-holding unit 35 is press-fitted to the connector hole forming portion, and a portion of the first solenoid side board-holding unit 36a is also press-fitted to the first solenoid hole forming portion. Accordingly, at the time when the board-holding units 35 and 36 are inserted and fitted to the mounting holes 51 and 52, the board 5 is reliably fixed to the case 3. Therefore, even when the board 5 is located below the case 3 when being soldered, the board 5 is not detached from the case 3. Meanwhile, the second solenoid side board-holding unit 36b is not press-fitted to the second solenoid hole forming portion.
Since the fluid pressure control device according to this embodiment is mounted in an engine room (not shown) of the vehicle, the resin case 3 may be deformed by heat generated at an engine (not shown).
As shown in
Since the bonding portion 7 between the connector terminals 6 and the board 5 is located near the connector side board-holding unit 35 the bonding portion 7 is displaced with the connector side board-holding unit 35 when the case 3 Is deformed by a heat load. Therefore, no relative displacement is generated between the bonding portion 7 and the connector side board-holding unit 35. As a result, a resistance against the motion of the bonding portion 7 during the case deformation is reduced, and a stress generated at the bonding portion 7 is reduced, thereby hardly causing solder cracking.
In addition, when the case 3 is deformed by the heat load, the board 5 likely turns around the solenoid side board-holding unit 36 as a fulcrum, which serves as a fulcrum. Since the insertion part 362 of the solenoid side board-holding unit 36 is divided by the slit 363 and thus elastically deformable, that is, since the solenoid side board-holding unit 36 allows the board 5 to easily rotate along With the thermal deformation of the case 3, the resistance against the motion of the bonding portion 7 during the case deformation can be further reduced.
In addition, because of reaction of the elastic deformation, the outer periphery of the solenoid side board-holding unit 36 can closely comes in contact with the inner periphery of the solenoid hole forming portion easily. As a result, positioning of the board 5 in the plate-face direction can be facilitated when being assembled to the case 3.
The solenoid side board-holding unit 36 is disposed in the solenoid housing 32 on the side opposite to the connector housing 33 with respect to the center in the reference direction Z, and the distance between the connector side board-holding unit 35 and the solenoid side board-holding unit 36 is large. Therefore the radius of rotation of the board 5 during the case deformation is large, and the angle of rotation of the board 5 during the case deformation accordingly becomes small. As a result, the amount of deformation of the insertion part 362 of the solenoid side board-holding unit 36 becomes small, and the resistance against the motion of the bonding portion 7 during the case deformation is further reduced.
Since the solenoid side board-holding unit 36 is loosely fitted to the solenoid side mounting hole 52, the board 5 can be easily displaced in the x direction along with the thermal deformation of the case 3. Accordingly, the resistance against the motion of the bonding portion 7 during the case deformation can be further reduced.
Since the sealing member applied between the solenoid terminal 22 and the terminal hole 31 is flexible, and the clinched part 221 is provided for allowing the solenoid terminal 22 to be easily elastically deformed, the solenoid terminal 22 can be easily displaced in the x and y directions, thereby reducing the resistance against the motion of the board 5 during the case deformation.
In this embodiment, the connector side board-holding unit 35 is the only unit of the case 3 which is to be inserted and fitted to a mounting hole of the board 5 and which is provided at the connector housing 33 side with respect to the connection portion 34. Therefore, as compared with a case where a plurality of connector side board-holding units having the same feature as the connector side board-holding unit 35 are provided, the space for arranging the connector terminal 6 can be easily obtained.
A second embodiment of the present invention is described below.
As shown in
In this embodiment, the mounting-hole distance H does not have to be smaller than the holding-unit distance L.
A third embodiment of the present invention is described below.
As shown in
The insertion part 354 has a columnar shape at a portion near the supporting part 353, and has a shape of a truncated cone shape at a portion near a tip end thereof. The outer diameter of the columnar portion of the insertion part 354 is smaller than the diameter of the connector side mounting hole 51. The outer diameter of the truncated-cone portion at the tip end of the insertion part 354 (i.e. a minimum outer diameter) is smaller than the diameter of the connector side mounting hole 51. The outer diameter of the truncated-cone portion of the insertion part 354 near the supporting part 353 (i.e. a maximum outer diameter) is larger than the diameter of the connector side mounting hole 51. The insertion part 354 is divided into two pieces by a slit 355 extending orthogonally to the board 5, thereby being easily elastically deformable.
In this embodiment, the mounting-hole distance H does not have to be smaller than the holding-unit distance L.
A fourth embodiment of the present invention is described below.
As shown in
A fifth embodiment of the present invention is described below.
As shown in
Accordingly, since there is provided the only one solenoid side board-holding unit 36 having the convex portion 362a as compared with, for example, a case where a plurality of solenoid side board-holding units 36 are provided, a restriction force against the turning of the board 5 caused by the convex portion 362a during the case deformation becomes small. As a result, the resistance against the motion of the board 5 during the case deformation is reduced, and the stress generated at the board 5 and the bonding portion 7 can be reduced.
Although the fluid pressure control device for the vehicle brake system is described in the above embodiments, the present invention may be also applied to fluid pressure control device s for other purposes.
Number | Date | Country | Kind |
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2006-316548 | Nov 2006 | JP | national |