JP5926096B2 - Torque rod - Google Patents

Description

  The present invention is, for example, bridged between the engine side and the body side of a vehicle, restricts displacement in the front-rear direction of the engine and rolls (rotation around the front-rear direction), and performs vibration isolation between the engine side and the body side. With respect to the torque rod, the torque rod is actively broken at the time of a vehicle collision.

  Conventionally, torque rods to be broken at the time of a vehicle collision are disclosed in Japanese Patent No. 4046093 (Patent Document 1), Japanese Patent No. 4046094 (Patent Document 2), Japanese Patent Laid-Open No. 2007-69748 (Patent Document 3), and Japanese Patent Laid-Open No. 2007. -69742 (patent document 4).

Japanese Patent No. 4046093 Japanese Patent No. 4046094 JP 2007-69748 A JP 2007-69742 A

  An object of this invention is to provide the torque rod which employ | adopts the structure of the fracture | rupture site | part different from the conventional fracture site | part.

A torque rod according to the present invention includes a first bush and a second bush each including an outer cylinder and an inner cylinder and a rubber elastic body connecting them, and an outer cylinder of the first bush and an outer cylinder of the second bush. A connecting portion to be connected, wherein the connecting portion is deformed so that a central axis of the connecting portion is bent by a collision-induced force received at the time of a vehicle collision, and one of the first bush and the second bush The inner cylinder is attached to a bracket and has a gap between the end surface of the one outer cylinder of the first bush and the second bush and the bracket in a state where the inner cylinder is not subjected to the collision-causing force . In response to the collision-causing force, the one outer cylinder of the first bush and the second bush is connected to the one of the first bush and the second bush. The outer cylinder is inclined with respect to the inner cylinder and the bracket, and the bracket is brought into contact with a portion of the end surface of the outer cylinder on the connecting portion side as the outer cylinder is inclined with respect to the bracket. The operation is restricted, and a fracture portion due to the bending deformation accompanying the restriction of the tilting operation is formed on the outer cylinder side where the bracket abuts in the connecting portion.

  That is, in the torque rod of the present invention, the connecting portion is bent and deformed when the vehicle collides. As the connecting portion is bent and deformed, the outer cylinder connected to the connecting portion also tends to tilt. However, when the outer cylinder moves a distance corresponding to the gap with the bracket, the end surface of the outer cylinder comes into contact with the bracket, and the tilting operation of the outer cylinder is restricted. Even after the tilting operation of the outer cylinder is restricted, if the bending force is further applied to the connecting portion, the largest stress is generated near the base of the outer cylinder side restricted by the bracket in the connecting portion. . That is, the connecting portion of the torque rod supported by the bracket is in a state corresponding to a cantilever beam that receives a concentrated load or moment in material mechanics. And by designing the site near the root to be a fracture site, the fracture site can be surely broken at the time of a collision.

In addition, the breakage portion is formed by forming a hollow portion penetrating in a direction perpendicular to the direction of bending deformation of the connecting portion and the central axis direction of the connecting portion, thereby forming a bent convex side with respect to the direction of bending deformation and You may make it equip each of a bending concave side with a bridge | bridging.
Further, a circumscribed circle of the second bush is formed larger than a circumscribed circle of the first bush, an axial width of the second bush is formed larger than an axial width of the first bush, and the connecting portion is The second bushing side of the connecting portion is connected to the outer peripheral surface of the outer cylinder of the second bushing and the second bushing. It is possible to connect continuously to at least three of the total four surfaces consisting of both end surfaces of the outer cylinder, and to form the fracture portion on the second bush side of the connecting portion.

  In this way, by forming the fractured portion with one bridge and the other with respect to the bending deformation direction (the bending convex bridge and the bending concave bridge), at least one of both bridges can be broken by the collision-causing force. it can. By the way, in order to have a normal function as a torque rod, it is necessary to ensure a sufficient load resistance against pulling or compression at the connecting portion. It is necessary to secure the necessary load resistance for the bending convex side bridge and the bending concave side bridge. For example, the load capacity of the bending convex bridge and the bending concave bridge can be ensured by sufficiently securing the volumes of the bending convex bridge and the bending concave bridge. However, simply increasing the volume increases the mass, which is not appropriate. In other words, what is required for the broken portion is to have the load resistance for having a normal function as a torque rod, to break by a collision-induced force, and to reduce the weight as much as possible.

  Therefore, by forming a breakage part on the side of the second bush having a large circumscribed circle and axial width, a joint part with the second bush in the connecting portion, that is, the width and height of the breakage part (outer shape of the breakage part) Can be increased. By forming each bridge in such a part, it is possible to increase the volume of the cutout part at the fractured part while ensuring a sufficient volume of each bridge. Therefore, the torque rod can be reliably functioned during normal operation, and the torque rod can be reduced in weight while breaking the connecting portion at the time of collision.

Moreover, you may form so that the said bending convex side bridge may fracture | rupture before the said bending concave side bridge.
Thereby, the bending convex bridge can be broken at the time of collision. Here, in the vicinity of the base on the bracket side in the connecting portion, a large tensile stress is generated on the convex deformation side on the convex deformation side and the concave deformation side in the bending deformation. Therefore, by making the part, that is, the bending convex bridge easier to break than the bending concave bridge, the breaking part can be reliably broken at the time of collision.

The deflection convex side bridge, which is connected with a step with respect to one end face of the first bushing and said one of the outer cylinder of the second bushing, wherein the deflection concave bridge, the first bush and the second You may make it connect smoothly without having a level | step difference with respect to the other end surface of said one outer cylinder of two bushes. Thereby, a bending convex bridge | bridging bridge can be made into a fracture | rupture site | part reliably.

It is a front view of the torque rod of the state attached to the bracket. In FIG. 1, the vertical direction indicates the vehicle vertical direction, the left side indicates the engine side, and the right side indicates the body side. It is the figure (plan view) seen from the upper surface of the paper of FIG. 1 of the torque rod in a state where the bracket is removed. It is AA sectional drawing of FIG. It is BB sectional drawing of FIG. It is a front view of a torque rod in the state just before a torque rod fractures. It is a front view of the torque rod in the state where the bending convex bridge of the torque rod was broken. It is a front view of a torque rod in a state where both bridges of the torque rod are broken.

  The torque rod will be described with reference to the drawings. The torque rod is bridged between the power unit 2 side such as a vehicle engine and the subframe 3 side constituting the vehicle body, and regulates the front-rear direction displacement and roll (rotation around the front-rear direction) of the power unit 2, and the power unit 2 side And vibration isolation between the sub-frame 3 side. In particular, the connecting portion 30 of the torque rod of the present embodiment is made of resin and is called a so-called resin torque rod.

  The connecting portion 30 of the torque rod is formed so as to be actively broken when an excessive load occurs due to a vehicle collision. Here, in the present embodiment, the torque rod is such that the connecting direction of the connecting portion 30 (the direction parallel to the central axis L of the connecting portion 30) coincides with the vehicle front-rear direction or with respect to the vehicle front-rear direction. Are attached to the power unit 2 and the subframe 3 so as to have a slight inclination angle. Here, the central axis L of the connecting portion 30 is a straight line connecting the elastic center of the small bush 10 and the elastic center of the large bush 20.

  The torque rod is deformed so as to bend the central axis L of the connecting portion 30 by a collision-causing force received during a vehicle collision. In FIG. 1, the bending deformation direction of the connecting portion 30 is the vehicle vertical direction. The torque rod includes a small bush 10 as a first bush, a large bush 20 as a second bush, and a connecting portion 30 that connects both the bushes 10 and 20.

  The small bush 10 includes a resin outer cylinder 11, a metal inner cylinder 12, and a rubber elastic body 13 that connects the inner peripheral surface of the outer cylinder 11 and the outer peripheral surface of the inner cylinder 12. The inner cylinder 12 of the small bush 10 is attached to the power unit 2 fixed to the bracket 2a via the bracket 2a. The bracket 2a is formed in a U-shape having an opening at the rear of the vehicle and an opposing portion in the vehicle vertical direction.

  The bracket 2a is fixed to the inner cylinder 12 so as to sandwich the inner cylinder 12 in the axial direction at the facing portion. That is, the small bush 10 is attached to the bracket 2a so that the axial direction thereof coincides with the vehicle vertical direction or is slightly inclined with respect to the vehicle vertical direction. The bracket 2a has a gap in the axial direction between both end surfaces 11a and 11b of the outer cylinder 11. That is, the outer cylinder 11 is provided so as to be relatively movable in the axial direction and the radial direction with respect to the inner cylinder 12 and the bracket 2a.

  The large bush 20 includes a resin outer cylinder 21, a metal inner cylinder 22, and a rubber elastic body 23 that connects the inner peripheral surface of the outer cylinder 21 and the outer peripheral surface of the inner cylinder 22. The circumscribed circle of the large bush 20 is formed larger than the circumscribed circle of the small bush 10. Furthermore, the axial width of the large bush 20 is formed larger than the axial width of the small bush 10.

  The inner cylinder 22 of the large bush 20 is attached to the subframe 3 fixed to the bracket 3a via the bracket 3a. The bracket 3a is formed in a U-shape having an opening in the front of the vehicle and an opposing portion in the vehicle vertical direction.

  The bracket 3a is fixed to the inner cylinder 22 so as to sandwich the inner cylinder 22 in the axial direction at the facing portion. That is, the large bush 20 is attached to the bracket 3a so that the axial direction thereof coincides with the vehicle vertical direction or is slightly inclined with respect to the vehicle vertical direction. The bracket 3a has a gap in the axial direction between both end faces 21a and 21b of the outer cylinder 21. That is, the outer cylinder 21 is provided so as to be relatively movable in the axial direction and the radial direction with respect to the inner cylinder 22 and the bracket 3a. Further, the rubber elastic body 23 is formed with curls 23a and 23b, and the spring characteristics are adjusted.

  The connecting portion 30 connects the outer cylinder 11 of the small bush 10 and the outer cylinder 21 of the large bush 20. In the present embodiment, the connecting portion 30 is made of resin and is integrally formed with the outer cylinder 11 of the small bush 10 and the outer cylinder 21 of the large bush 20. Moreover, the connection part 30 has connected both so that the axial direction of the big bush 20 and the axial direction of the small bush 10 may become parallel. However, the axial directions of the bushes 10 and 20 may be substantially orthogonal when viewed from the central axis L of the connecting portion 30.

  As shown in FIGS. 2 and 4, the connecting portion 30 is formed in a shape in which the central portion in the central axis L direction is constricted when viewed from the axial direction of the large bush 20. Further, the small bush 10 side of the connecting portion 30 is for all four surfaces including two surfaces connected to the outer peripheral surface of the outer cylinder 11 of the small bush 10 and both end surfaces 11a and 11b of the outer cylinder 11 of the small bush 10. Connected continuously. That is, both are connected without having a step.

  Further, the large bush 20 side of the connecting portion 30 is at least 3 out of a total of four surfaces including two surfaces connected to the outer peripheral surface of the outer cylinder 21 of the large bush 20 and both end surfaces 21a and 21b of the outer cylinder 21 of the large bush 20. Continuously connected to the surface. Of the four surfaces on the large bush 20 side, the remaining one surface is not directed inward from at least the central portion of the connecting portion 30 in the direction of the central axis L.

  And as shown in FIG. 3, the axial direction width | variety (vehicle vertical width) of the large bush 20 in the connection part 30 is formed so that it may become large as it goes to the large bush 20 side from the small bush 10 side. In particular, as shown in FIGS. 1 and 3, the vehicle vertical width of the connecting portion 30 is formed to be the same as the axial width of the small bush 10 from the small bush 10 side to the central portion in the central axis L direction. And the vehicle vertical width of the connection part 30 is formed so that it may become large in the large bush 20 side from the connection direction center part.

  More specifically, the lower end surface 30a of the vehicle in the connecting portion 30 is formed in the same plane as the lower end surface 11a of the outer cylinder 11 of the small bush 10 and is connected to the outer cylinder 21 of the large bush 20. The base portion is formed to have a stepped step in the direction in which the width of the connecting portion 30 expands (the vehicle lower side). That is, the root portion forms a corner portion C of about 90 °. Further, most of the vehicle upper end surface 30 b in the connecting portion 30 is formed in the same plane as the vehicle upper end surface 11 b of the outer cylinder 11 of the small bush 10, and on the outer cylinder 21 side of the large bush 20, the connecting portion 30. Is gently inclined in the direction in which the width of the vehicle increases (the vehicle upper side).

  The connecting portion 30 is formed with a first lightening portion 31 and a second lightening portion 32. The first cutout portion 31 is formed for the purpose of reducing the weight while having a normal function as a torque rod while forming a rupture site for a collision-induced force.

  As shown in FIG. 4, the first cutout portion 31 is on the large bush 20 side of the connecting portion 30 in a direction perpendicular to the axial direction of the large bush 20 (the vertical direction in FIGS. 2 and 4). , Penetrated. This penetrating direction corresponds to the direction of bending deformation of the connecting portion 30 (up and down direction in FIG. 1) and the direction perpendicular to the central axis L direction. In this way, by forming the first cutout portion 31, the portion of the connecting portion 30 is located on the vehicle lower end surface (the lower end surface in FIGS. 1 and 3) 21 a side of the outer cylinder 21 of the large bush 20. A vehicle lower bridge 36 to be connected and a vehicle upper bridge 37 connected to the vehicle upper end surface (upper end surface in FIGS. 1 and 3) 21b of the outer cylinder 21 are provided. Here, the connecting portion 30 is bent and deformed so as to be convex toward the vehicle lower side. Therefore, the vehicle lower bridge 36 is referred to as a flexure convex bridge, and the vehicle upper bridge 37 is referred to as a flexure concave bridge.

  The thicknesses of the flexure convex side bridge 36 and the flexure concave side bridge 37 are substantially constant. The flexure convex side bridge 36 is formed so as to extend substantially parallel to the central axis L direction (left and right direction in FIG. 3) of the connecting portion 30, and in the base portion on the large bush 20 side of the flexure convex side bridge 36, The corner C of the step-shaped step described above is formed. The bending concave bridge 37 is formed in a direction that is gently inclined with respect to the direction of the central axis L of the connecting portion 30, and is smoothly connected to the vehicle upper end surface 21 b of the outer cylinder 21 of the large bush 20. .

  The flexure convex side bridge 36 and the flexure concave side bridge 37 have a volume sufficient to have a normal function as a torque rod. In particular, since both the bridges 36 and 37 are formed on the side of the large bush 20 having a large circumscribed circle and an axial width, the bridges 36 and 37 are connected to the large bush 20 of the connecting portion 30 as compared with the case of forming on the small bush 10 side. The width and height of the entire joining site (outer shape of the fracture site) can be increased. By forming the bridges 36 and 37 in such a part, even if the sufficiently large volume of the first cutout portion 31 is formed, a sufficient volume of the bridges 36 and 37 can be secured.

  Therefore, both bridges 36 and 37 can have sufficient tensile strength, compressive strength, and torsional strength. Furthermore, weight reduction can be achieved by forming the first cutout portion 31 while ensuring the strength in this way. That is, even if the first cutout portion 31 is formed, it can have a normal function as a torque rod. Further, as will be described in detail later, the vicinity of the corner portion C of the base portion of the flexural convex side bridge 36 is set as a fracture portion due to the flexural deformation of the connecting portion 30 due to the collision-causing force at the time of the vehicle collision.

  A plurality of the second lightening portions 32 are formed mainly in order to reduce the weight. The plurality of second thinned portions 32 are formed on the small bush 10 side of the connecting portion 30 so as to open to the vehicle lower end surface 30a side and to be closed to the vehicle upper end surface 30b side. As a result, even if water, mud, or the like enters during traveling of the vehicle, it can be discharged downward in the vehicle without accumulating in the second cutout portion 32.

  Next, the operation of the torque rod at the time of a vehicle collision will be described with reference to FIGS. 1 and 5 to 7. Here, a large force is generated in the power unit 2 toward the rear lower side of the vehicle at the time of a vehicle collision (indicated by an arrow in the power unit 2 in FIG. 5). Then, structurally, the subframe 3 is broken, and the subframe 3 rotates so that the opening of the bracket 3a of the subframe 3 faces the vehicle lower side as shown in FIG.

  Here, the inner cylinder 22 of the large bush 20 is fixed to the bracket 3 a of the subframe 3, and the bracket 3 a has an axial clearance from both end faces 21 a and 21 b of the outer cylinder 21. Therefore, when the bracket 3a of the subframe 3 rotates, the outer cylinder 21 of the large bush 20 tends to tilt.

  However, when the bracket 3a of the subframe 3 moves a distance corresponding to the gap between the outer cylinder 21 and the vehicle upper end surface 21b, the vehicle upper end surface 21b of the outer cylinder 21 comes into contact with the bracket 3a. Be regulated. At this time, the outer cylinder 21 of the large bush 20 receives a downward force (or moment) F1 of the vehicle by the bracket 3a, and the outer cylinder of the small bush 10 moves from the bracket 2a to the rear lower side of the vehicle as the power unit 2 moves. The force (or moment) F2 is received. That is, the connecting portion 30 of the torque rod supported by the bracket 3a is in a state corresponding to a cantilever beam that receives a concentrated load or moment in material mechanics.

  Accordingly, the connecting portion 30 is bent and deformed so that the lower side of the connecting portion 30 is convex. Even after the tilting operation of the outer cylinder 21 is restricted, if the bending force is further applied to the connecting portion 30, the root on the outer cylinder 21 side that is restricted by the bracket 3 a of the connecting portion 30. The greatest stress is generated in the vicinity.

  Here, a bending convex side bridge 36 and a bending concave side bridge 37 are formed on the large bush 20 side of the connecting portion 30. In particular, a corner portion C where stress tends to concentrate is formed at the root portion of the flexural convex side bridge 36, whereas the flexure concave side bridge 37 is provided on the outside of the large bush 20 so as to be relatively difficult to concentrate stress. The cylinder 21 is smoothly connected to the vehicle upper end surface 21b.

  A large tensile stress is generated on the convex deformation side on the convex deformation side and the concave deformation side in the bending deformation. Therefore, a larger tensile stress than that of the bending concave bridge 37 is generated at the corner C of the bending convex bridge 36. As a result, as shown in FIG. 6, the corner portion C of the bent convex side bridge 36 is the starting point, and the vicinity of the corner portion C breaks before the bent concave side bridge 37 and other portions.

  Thereafter, when further forces (or moments) F1 and F2 are applied, as shown in FIG. 7, the power unit 2 tries to move further to the lower rear side of the vehicle, and the subframe 3 tries to rotate. As a result, the breaking distance of the bending convex bridge 36 increases, and the bending concave bridge 37 receiving a load from the bracket 3a breaks. And after the bending convex side bridge 36 and the bending concave side bridge 37 fracture | rupture, the power unit 2 falls out to a vehicle lower side, and can ensure the safety | security of the passenger | crew in a vehicle interior.

DESCRIPTION OF SYMBOLS 10: Small bush (1st bush), 11: Outer cylinder, 11a: Vehicle lower side end surface, 11b: Vehicle upper side end surface, 12: Inner cylinder, 13: Rubber elastic body, 20: Large bush (2nd bush), 21 : Outer cylinder, 21a: Vehicle lower end face, 21b: Vehicle upper end face, 22: Inner cylinder, 23: Rubber elastic body, 23a, 23b: Straight, 30: Connecting part, 30a: Vehicle lower end face, 30b: Vehicle upper end face End face 31: First thinned portion 32: Second thinned portion 36: Deflection convex side bridge 37: Deflection concave side bridge 2: Power unit 2a: Bracket 3: Sub frame 3a: Bracket L : Center axis of connecting part

Claims (5)

A first bush and a second bush each comprising an outer cylinder and an inner cylinder and a rubber elastic body for connecting them; and a connecting portion for connecting the outer cylinder of the first bush and the outer cylinder of the second bush; A torque rod comprising:
The connecting portion is deformed so that the central axis of the connecting portion is bent by a collision-causing force received at the time of a vehicle collision,
One inner cylinder of the first bush and the second bush is attached to a bracket,
In a state where the collision-causing force is not received , a gap is provided between an end surface of the one outer cylinder of the first bush and the second bush and the bracket,
In response to the collision-causing force, the one outer cylinder of the first bush and the second bush is inclined with respect to the inner cylinder and the bracket in the one of the first bush and the second bush. ,
Along with the tilting operation of the outer cylinder with respect to the bracket, the bracket is brought into contact with a portion of the end surface of the outer cylinder on the connecting portion side, whereby the tilting operation of the outer cylinder is restricted.
A torque rod that forms a breakage site due to bending deformation associated with restriction of the tilting operation on the outer cylinder side with which the bracket abuts in the connecting portion.   The breakage portion is formed by forming a hollow portion penetrating in a direction perpendicular to the direction of deformation of the connecting portion and the direction of the central axis of the connecting portion. The torque rod of claim 1, comprising a bridge on each side. The torque rod according to claim 2, wherein the bending convex bridge is formed to break before the bending concave bridge . The deflection convex side bridge is connected with a step with respect to one end surface of the one outer cylinder of the first bush and the second bush,
Wherein the deflection concave bridge, the first bush and the second bush of the are smoothly connected by no step to the other end surface of one of the outer cylinder, the torque rod according to claim 3. The circumscribed circle of the second bush is formed larger than the circumscribed circle of the first bush,
The axial width of the second bush is formed larger than the axial width of the first bush,
The connecting portion is formed such that the central portion in the central axis direction has a constricted shape,
Of the connecting portion, the second bush side is at least three of a total of four surfaces including two surfaces connected to the outer peripheral surface of the outer cylinder of the second bush and both end surfaces of the outer cylinder of the second bush. Continuously connected to
Forming the fracture site to the second bushing side of the connecting portion, any one of the torque rod according to claim 2-4.

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