bushing mounting structure

Abstract

To improve strength of attachment of a bush to a plate-like member.SOLUTION: An end part in a longitudinal direction of a plate-like member 10A is provided with a bush attachment hole 12 penetrating in a thickness direction of the plate-like member 10A. A cylindrical burring part 14 protruding to one side in the thickness direction of the plate-like member 10A from an edge part of the bush attachment hole 12 is provided. In the burring part 14, a locking piece 16 for preventing movement in an axial direction of the bush 18 by engaging with a concave part 26 of the bush 18 is formed.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a mounting structure of a bush.

Background Art

[0002] A roll rod is provided to suppress the transmission of the reaction force and vibration of the torque generated by the power plant to the vehicle body by connecting the power plant of the vehicle and the suspension cross member. The roll rod is formed of a plate-shaped member, one end in its longitudinal direction is connected to the power plant via a front bush, and the other end is connected to the suspension cross member via a rear bush (see Patent Document 1). The front and rear bushes are composed of an inner cylinder, an outer cylinder, and an elastic member provided between them, and the front and rear bushes are attached to the body by press-fitting their outer cylinders into the burring portions formed on the roll rod.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] As described above, the bush is attached to the roll rod by press-fitting, so that the attachment strength of the bush to the roll rod is ensured to a certain extent. However, considering the case where a large force is applied during a vehicle collision or the like, it is desired to further improve the attachment strength of the bush to the roll rod. Furthermore, since the structure of attaching bushings to plate-shaped members such as roll rods by press-fitting is also used in the lower arms and trailing arms of suspensions, there is a desire to further improve the mounting strength of bushings to such plate-shaped members. The present invention has been made in view of the above circumstances, and aims to provide a bushing mounting structure that is advantageous in improving the mounting strength of the bushing to a plate-shaped member. [Means for solving the problem]

[0005] To achieve the above objective, one embodiment of the present invention provides a bush mounting structure in which the outer cylinder of a bush, which consists of an inner cylinder, an outer cylinder, and an elastic member provided between them, is press-fitted into a burring portion provided on a plate-shaped member, wherein a recess is provided on the outer circumference of the outer cylinder, and a locking piece is provided on the burring portion that engages with the recess and prevents the bush from moving in the axial direction. The elastic member is provided with alternating slits and solid sections along its circumferential direction, and the recess is provided at the location on the outer circumference of the outer cylinder corresponding to the solid section. It is characterized by the following: [Effects of the Invention]

[0006] According to one embodiment of the present invention, a recess is provided on the outer circumference of the outer cylinder of the bush, and a locking piece is provided on the burring portion that engages with the recess to prevent the bush from moving in the axial direction. Therefore, even if a large force is applied to the bush due to a vehicle collision or the like, the bush can be prevented from moving in the axial direction, which is advantageous in improving the mounting strength of the bush to the plate-shaped member. [Brief explanation of the drawing]

[0007] [Figure 1] This is an explanatory diagram of the bush mounting structure according to the first embodiment, where (A) is a cross-sectional view and (B) is a cross-sectional view of the outer cylinder of (A) along line BB. [Figure 2] (A) is a plan view of the plate-shaped member, and (B) is a perspective view of the locking piece. [Figure 3] This is an explanatory diagram of the bush mounting structure according to the second embodiment, where (A) is a cross-sectional view and (B) is a cross-sectional view of the outer cylinder along line BB of (A). [Figure 4] This is a cross-sectional view of the outer cylinder along line CC in Figure 3(A). [Figure 5] This is an explanatory diagram of the bush mounting structure according to the third embodiment, where (A) is a cross-sectional view and (B) is a perspective view of the locking piece. [Figure 6] This is a plan view of the bushing mounting structure according to the fourth embodiment. [Modes for carrying out the invention]

[0008] (First Embodiment) Hereinafter, embodiments of the present invention will be described with reference to the drawings. This embodiment describes a case in which the bushing mounting structure of the present invention is applied to a roll rod connecting the vehicle's power plant and suspension cross member. As shown in Figures 1(A) and 2(A), the roll rod 10 is composed of an elongated, plate-shaped member 10A made of sheet metal. A bushing mounting hole 12 is provided at the longitudinal end of the plate-shaped member 10A, penetrating through the thickness direction of the plate-shaped member 10A. A cylindrical burring portion 14 is provided that protrudes from the edge of the bush mounting hole 12 in one direction in the thickness direction of the plate-shaped member 10A. The burring portion 14 is formed with a locking piece 16 that engages with a recess 26 of the bush 18 (described later) and prevents the bush 18 from moving in the axial direction. In this embodiment, three locking pieces 16 are formed at equal intervals in the circumferential direction with respect to the axis of the burring portion 14, and each has a uniform width along the circumferential direction of the burring portion 14. The inner circumferential surface of the burring portion 14, excluding the locking pieces 16, is formed as a cylindrical surface with a uniform radius. As shown in Figures 1(A), 2(A), and (B), each locking piece 16 is provided with an inclination that causes it to be displaced radially inward of the burring portion 14 as it approaches the tip of the burring portion 14. Each locking piece 16 comprises a locking piece inner surface 1602 facing radially inward of the burring portion 14, a pair of locking piece side surfaces 1604 located at both ends in the width direction of the locking piece inner surface 1602, and a locking piece tip surface 1606 located at the tip.

[0009] As shown in Figures 1(A) and (B), the bush 18 comprises a metal inner cylinder 20, an outer cylinder 22, and an elastic member 24. The inner cylinder 20 and the outer cylinder 22 are cylindrical in shape. The outer cylinder 22 has a shorter axial length than the inner cylinder 20 and an inner diameter larger than the outer diameter of the inner cylinder 20. The inner cylinder 20 is connected to a power plant or suspension cross member (not shown) via fastening members such as bolts and nuts. The elastic member 24 is provided between the inner cylinder 20 and the outer cylinder 22 and is made of various conventionally known elastic materials such as rubber. The elastic member 24 has an inner circumferential surface into which the inner cylinder 20 is inserted, and an outer circumferential surface into which the outer cylinder 22 is inserted. The inner circumferential surface of the elastic member 24 is vulcanized and bonded to the outer circumferential surface of the inner cylinder 20, and the outer circumferential surface of the elastic member 24 is vulcanized and bonded to the inner circumferential surface of the outer cylinder 22.

[0010] As shown in Figures 1(A) and (B), the outer circumference of the outer cylinder 22 is provided with recesses 26 into which the locking piece 16 can be detachably locked. Three recesses 26 are provided on the outer circumference of the outer cylinder 22 at equal intervals in the circumferential direction. The recess 26 includes an inner surface locking surface 2602 into which the inner surface 1602 of the locking piece locks, a pair of side surface locking surfaces 2604 into which the pair of side surfaces 1604 of the locking piece locks, and a front surface locking surface 2606 into which the front surface 1606 of the locking piece locks.

[0011] Next, the attachment of the bush 18 to the plate-shaped member 10A will be described. As shown in Fig. 1(A), above a plate-shaped member 10A with the flanging portion 14 facing downward, the axis of the bush 18 is aligned with the axis of the flanging portion 14, and with the phases of the locking pieces 16 of the flanging portion 14 and the recesses 26 of the bush 18 aligned, the bush 18 is moved downward and press-fitted into the bush mounting hole 12. When the bush 18 is moved in the axial direction with the outer peripheral surface of the outer cylinder 22 of the bush 18 being in pressure contact with the inner peripheral surface of the flanging portion 14, eventually, each locking piece 16 locks into each recess 26. Specifically, the locking piece 16 enters the recess 26, the locking piece inner surface 1602 of the locking piece 16 faces the inner surface locking surface 2602, the pair of locking piece side surfaces 1604 of the locking piece 16 lock to the pair of side surface locking surfaces 2604 of the recess 26, and the locking piece tip surface 1606 of the locking piece 16 locks to the tip surface locking surface 2606 of the recess 26, whereby the bush 18 is attached to the plate-shaped member 10A with the outer peripheral surface of the outer cylinder 22 of the bush 18 being press-fitted into the inner peripheral surface of the flanging portion 14. In the present embodiment, with the outer peripheral surface of the outer cylinder 22 of the bush 18 being press-fitted into the inner peripheral surface of the flanging portion 14, the locking piece tip surface 1606 of the locking piece 16 locks to the tip surface locking surface 2606 of the recess 26 to prevent movement of the bush 18 in one of the two axial directions. Also, when the locking piece inner surface 1602 of the locking piece 16 locks to the inner surface locking surface 2602 of the recess 26 due to displacement of the bush 18 in the other of the two axial directions, movement of the bush 18 in the other of the two axial directions is prevented. Moreover, with the outer peripheral surface of the outer cylinder 22 of the bush 18 being press-fitted into the inner peripheral surface of the flanging portion 14, the pair of locking piece side surfaces 1604 of the locking piece 16 of the outer cylinder 22 lock to the pair of side surface locking surfaces 2604 of the recess 26 of the flanging portion 14 to prevent movement of the bush 18 in the rotational direction about the axial direction.

[0012] According to this embodiment, a recess 26 is provided on the outer circumference of the outer cylinder 22 of the bush 18, and a locking piece 16 is provided on the burring portion 14 that engages with the recess 26 and prevents the bush 18 from moving in the axial direction. Therefore, even if a large force is applied to the bush 18 due to a vehicle collision or the like, the bush 18 can be prevented from moving in the axial direction, which is advantageous in improving the mounting strength of the bush 18 to the plate-shaped member 10A.

[0013] Furthermore, according to this embodiment, since multiple recesses 26 and locking pieces 16 are provided at intervals in the circumferential direction of the outer cylinder 22, each locking piece 16 can lock into each recess 26, thereby preventing rotational movement of the bush 18 around its axis, which is advantageous in improving the mounting strength of the bush 18 to the plate-shaped member 10A.

[0014] (Second Embodiment) Next, a second embodiment will be described with reference to Figures 3 and 4. In the following embodiments, parts and components similar to those in the first embodiment will be denoted by the same reference numerals, and their descriptions will be omitted. The descriptions will focus on the differences. As shown in Figures 3(A) and (B), the second embodiment differs from the first embodiment in that a bulge 28 is provided on the outer circumference of the outer cylinder 22, which bulges radially outward, while the other parts are the same as those of the first embodiment.

[0015] The bulging portion 28 engages with the burring portion 14 and prevents the bush 18 from moving in the other direction of the axial direction. As shown in Figures 3(B) and 4, there are three bulging portions 28 provided on the outer circumference of the outer cylinder 22 at equal intervals in the circumferential direction, with a phase difference from the three recesses 26 of the outer cylinder 22. The bulging portion 28 is equipped with a locking surface 2802 facing the burring portion 14. In the second embodiment, with the bush 18 pressed into the burring portion 14, the locking surface 2802 of the bulging portion 28 locks to the base end of the burring portion 14.

[0016] According to the second embodiment, in addition to achieving the same effects as the first embodiment, the movement of the bush 18 in the other direction in the axial direction can be more reliably prevented because, in addition to the locking of the inner surface 1602 of the locking piece and the inner surface locking surface 2602, the locking surface 2802 and the burring portion 14 are locked together. This is more advantageous in improving the mounting strength of the bush 18 to the plate-shaped member 10A.

[0017] In the second embodiment, a case was described in which multiple bulges 28 are provided at intervals in the circumferential direction on the outer circumference of the outer cylinder 22. However, the bulges 28 may also be formed around the entire circumference of the outer circumference of the outer cylinder 22. In this case, the bulging portion 28 can increase the strength and rigidity of the outer cylinder 22, which is advantageous in suppressing deformation of the outer cylinder 22 when a large force is applied to the outer cylinder 22, such as during a vehicle collision, and is even more advantageous in improving the mounting strength of the bush 18 to the plate-shaped member 10A.

[0018] (Third embodiment) Next, a third embodiment will be described with reference to Figure 5. As shown in Figure 5, in the third embodiment, the shape of the three locking pieces 30 formed on the burring portion 14 and the shape of the three recesses 32 on the outer cylinder 22 differ from those in the first and second embodiments. The locking piece 30 is separated from the tip of the burring portion 14 at a point away from it, and its tip is positioned so that it is displaced radially inward from the burring portion 14. The locking piece 30 has an inner surface 3010 facing radially inward of the burring portion 14, a pair of side surfaces 3012 located at both ends in the width direction of the locking piece 30, and a tip surface 3014 located at the tip of the locking piece 30. The outer circumference of the outer cylinder 22 is provided with recesses 32 into which the locking piece 30 can be removably locked, and with bulging portions 34 having locking surfaces 3402 into which the tip of the burring portion 14 can be locked. Three recesses 32 are provided on the outer circumference of the outer cylinder 22 at equal intervals in the circumferential direction, and the bulging portions 34 are provided around the entire circumference of the outer cylinder. The recess 32 includes a locking surface 3202 for the base end face of the locking piece, which the tip of the burring portion 14 locks into; an inner surface locking surface 3204 which the inner surface 3010 of the locking piece faces; a pair of side surface locking surfaces (not shown) which the pair of side surfaces 3012 of the locking piece lock into; and a tip surface locking surface 3206 which the tip surface 3014 of the locking piece locks into. The locking surface 3202 for the base end face of the locking piece is formed by the locking surface 3402 of the bulging portion 34.

[0019] Next, the attachment of the bush 18 to the plate-shaped member 10A will be described. With the burring portion 14 facing downwards, the axis of the bush 18 is aligned with the axis of the burring portion 14 below the plate-shaped member 10A, and the phase of the locking piece 30 of the burring portion 14 and the recess 32 of the bush 18 are aligned, and the bush 18 is moved upward and pressed into the bush mounting hole 12. With the outer circumferential surface of the outer cylinder 22 of the bush 18 pressed against the inner circumferential surface of the burring portion 14, when the bush 18 is moved in the axial direction, each locking piece 30 will eventually engage with each recess 32. In detail, the locking piece 30 fits into the recess 32, the tip of the burring portion 14 engages with the locking surface 3202 for the base end of the locking piece in the recess 32, and the locking tip surface 3014 of the locking piece 30 engages with the locking surface 3206 for the tip of the recess 32. Furthermore, the inner surface 3010 of the locking piece 30 faces the inner surface locking surface 3204. Furthermore, the pair of locking side surfaces 3012 of the locking piece 30 engage with the pair of side locking surfaces of the recess 32. Furthermore, the locking surface 3402 of the bulging portion 34 locks into the tip of the burring portion 14. In this way, the bush 18 is attached to the plate-shaped member 10A with the outer circumferential surface of the outer cylinder 22 of the bush 18 pressed into the inner circumferential surface of the burring portion 14.

[0020] According to the third embodiment, with the outer circumferential surface of the outer cylinder 22 of the bush 18 pressed into the inner circumferential surface of the burring portion 14, the tip of the burring portion 14 engages with the locking surface 3202 for the base end face of the locking piece of the recess 32, and the locking tip surface 3014 of the locking piece 30 engages with the locking surface 3206 for the tip face of the recess 32. This prevents the bush 18 from moving in both directions in the axial direction, which is advantageous in improving the mounting strength of the bush 18 to the plate-shaped member 10A. Furthermore, since the locking surface 3402 of the bulging portion 34 locks onto the tip of the burring portion 14, it is more advantageous than the first embodiment in preventing the bush 18 from moving in the other direction of the axial direction, and is more advantageous in improving the mounting strength of the bush 18 to the plate-shaped member 10A. Furthermore, similar to the first and second embodiments, since multiple recesses 32 and locking pieces 30 are provided at intervals in the circumferential direction of the outer cylinder 22, each locking piece 30 can engage with each recess 32, thereby preventing rotational movement of the bush 18 around its axis, which is advantageous in improving the mounting strength of the bush 18 to the plate-shaped member 10A.

[0021] (Fourth embodiment) Next, a fourth embodiment will be described with reference to Figure 6. Figure 6 is a plan view showing the state in which a bush 18 is attached to one end of the roll rod 10. As shown in Figure 6, the elastic member 24 is provided with alternating ribbed portions 36 and solid portions 38 along its circumferential direction. In this embodiment, a pair of identically shaped and sized trimmed portions 36 are provided at two locations where they face each other in the diametrical direction of the bush 18 and intersect with the center line CL of the roll rod 10 in plan view. The pair of grooved portions 36 penetrate through the bush 18 along its axial direction and are formed to extend in an arc shape with respect to the axis of the bush 18. The solid portion 38 is located between the pair of tapered portions 36. By providing these grooved portions 36 and solid portions 38, the stiffness (spring constant) of the elastic member 24 in the diametrical direction of the bush 18 and in the direction connecting the pair of grooved portions 36 is set lower than the stiffness (spring constant) of the elastic member 24 in the diametrical direction of the bush 18 and in the direction connecting the opposing solid portions 38. In other words, the rigidity of the solid portion 38 of the elastic member 24 is higher than the rigidity of the portion where the tapered portion 36 is provided. The locking pieces 16 of the burring portion 14 and the recesses 26 of the outer cylinder 22 are formed in the same manner as in the first embodiment. The recesses 26 are provided at two locations on the outer circumference of the outer cylinder 22 corresponding to the solid portion 38, and the locking pieces 16 are provided at two locations on the burring portion 14 corresponding to the recesses 26.

[0022] According to the fourth embodiment, the portion of the outer cylinder 22 corresponding to the solid portion 38 is vulcanized and bonded to the portion of the highly rigid elastic member 24, and the portion of the outer cylinder 22 corresponding to the tapered portion 36 is vulcanized and bonded to the portion of the less rigid elastic member 24. Therefore, the portion of the outer cylinder 22 corresponding to the solid portion 38 has higher rigidity than the portion of the outer cylinder 22 corresponding to the tapered portion 36. Therefore, by providing a recess 26 in the highly rigid outer cylinder 22 corresponding to the solid portion 38, it is advantageous in suppressing deformation of the outer cylinder 22 when a large force is applied to the outer cylinder 22 from the locking piece 16 through the recess 26 during a vehicle collision, and is advantageous in improving the mounting strength of the bush 18 to the plate-shaped member 10A.

[0023] In the fourth embodiment, a case was described in which a pair of identically shaped and sized grooves 36 extending in an arc shape around the axis of the bush 18 are provided facing each other in the diametrical direction of the bush 18. However, the shape of the grooves 36, the number of grooves 36, the position of the grooves 36, etc., are appropriately set according to the required specifications for the rigidity (spring constant) of the elastic member 24 in a specific direction. Furthermore, the fourth embodiment may also be provided with a bulge 34 similar to that of the second embodiment, and in that case, it is optional to form the bulge 34 over the entire circumference of the outer periphery of the outer cylinder 22. Furthermore, the fourth embodiment may optionally include the same locking piece 30, recess 32, and bulge 34 as in the third embodiment.

[0024] In the embodiment described, the case in which the plate-shaped member 10A is a roll rod 10 was explained, but the present invention is broadly applicable to structures in which a bushing is press-fitted and attached to a plate-shaped member such as a lower arm or trailing arm of a suspension. [Explanation of symbols]

[0025] 10 Roll Rods 10A Plate-shaped member 12 bushing mounting holes 14 Burring section 16 Locking piece 1602 Inner surface of locking piece 1604 Locking side 1606 End surface of locking piece 18 Bush 20 Inner cylinder 22 Outer cylinder 24 Elastic members 26 recesses 2602 Inner surface locking surface 2604 Side locking surface 2606 Locking surface for tip surface 28 Bulge 2802 Locking surface 30 locking pieces 3010 Inner surface of locking piece 3012 Locking side 3014 Locking piece tip surface 32 recesses 3202 Locking surface for proximal end of locking piece 3204 Inner surface locking surface 3206 Locking surface for tip surface 34 Bulge 3402 Locking surface 36 Suguribu 38 Junior High School

Claims

1. A bushing mounting structure in which the outer cylinder of a bushing, which consists of an inner cylinder, an outer cylinder, and an elastic member provided between them, is press-fitted into a burring portion provided on a plate-shaped member, A recess is provided on the outer circumference of the outer cylinder, A locking piece is provided on the burring portion to engage with the recess and prevent the bush from moving in the axial direction. The elastic member is provided with alternating serrated and solid portions along its circumferential direction. The recess is provided at a location on the outer circumference of the outer cylinder corresponding to the solid portion. A bushing mounting structure characterized by the following features.

2. Multiple recesses and locking pieces are provided at intervals in the circumferential direction of the outer cylinder. The bushing mounting structure according to feature 1.

3. The locking of the locking piece and the recess prevents the bush from moving in one of the two directions along the axial direction of the bush. A bulge is provided on the outer circumference of the outer cylinder that engages with the burring portion and prevents the bush from moving in the other direction of the axial direction of the bush. The bushing mounting structure according to claim 1 or 2, characterized by the features described above.

4. The bulge is formed around the entire circumference of the outer periphery of the outer cylinder. The bushing mounting structure according to feature 3.

Images