JP2018017312A - Shock absorber - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a shock absorber which suppresses the impairment of performance even if the shock absorber is attached in a state that a shaft is inclined to an attachment shaft, and can exert original performance.SOLUTION: A shock absorber comprises: an end bolt 4 which is connected to at least either of an outer shell and a rod; a pair of annular rubber bushes 5, 6 which are attached to an external periphery of the end bolt 4, and sandwich an attachment part b1 of a vehicle; and a pair of washers 7, 8 for sandwiching a pair of the rubber bushes 5, 6. The rubber bushes 5, 6 have clearance forming parts 51, 52, 61 and 62 which are gradually contracted in diameters of outside diameters as progressing toward tips, and form clearances at least at either of the attachment part b1 sides of the rubber bushes 5, 6, or at the washers 7, 8 sides at least at either of one end part or the other end part in the axial direction. The clearances are formed in positions which are overlapped on the washers 7, 8 in a view in the axial direction.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a shock absorber.

  Some shock absorbers interposed between the vehicle body and the wheels of the vehicle have an end bolt and are connected to the vehicle body using the end bolt (for example, Patent Document 1). When such a connection structure is employed, an attachment hole for allowing the end bolt to be inserted is formed in an attachment portion for attaching the shock absorber in the vehicle body. Further, a screw portion into which a nut is screwed is formed at the tip of the end bolt, and a stopper portion having an enlarged diameter is provided at the end of the end bolt. Further, a pair of rubber bushes and a pair of washers sandwiching the rubber bushes are mounted on the outer periphery of the end bolt.

  Then, with one washer and one rubber bush attached to the outer periphery of the end bolt, the end bolt's tip was inserted into the mounting hole from the outside to the inside of the vehicle body, and protruded into the vehicle interior. When the other rubber bush and the other washer are attached to each other and the nut is screwed into the screw portion, the one rubber bush is compressed between the washer supported by the stopper and the vehicle body, and the nut The other rubber bush is compressed between the other supported washer and the vehicle body. Therefore, the end bolt and the vehicle body are connected in a state where the vehicle body is sandwiched between the pair of rubber bushes, and thereby the shock absorber and the vehicle body are connected.

JP 2003-148547 A

  When the shock absorber is attached to the vehicle body, the attachment angle of the shock absorber with respect to the attachment portion is determined for each vehicle. As shown in FIG. 7A, when the shock absorber A4 is attached so that the axis X of the shock absorber A4 overlaps the predetermined attachment shaft Y, the rubber bushes 500 and 600 are uniformly compressed in the circumferential direction. However, depending on the vehicle, the shock absorber A4 is attached to the vehicle body with the axis X tilted with respect to the mounting axis Y due to the influence of the dimensional tolerance of the vehicle body, the displacement of the wheel position, the displacement of the arm position supporting the wheel, etc. May be. When the shock absorber A is attached in an inclined state in this way, the end bolt 400, the rubber bushings 500 and 600, and the washers 700 and 800 are inclined with respect to the attachment portion b1 together with the shock absorber A4, and the rubber bushes 500 and 600 are compressed. The amount becomes uneven in the circumferential direction.

  Specifically, for example, as shown in FIG. 7B, when the axis X of the shock absorber A4 is tilted counterclockwise with respect to the mounting axis Y, the left side of the upper rubber bush 500 and the lower rubber bush While the compression amount on the right side of 600 increases, the compression amount of the portion increases as it goes toward the outer peripheral end. As described above, in the portion where the amount of compression in the rubber bushes 500 and 600 is large, the elastic force for returning to the original shape becomes large.

  That is, in FIG. 7B, the elastic force of the left outer peripheral portion of the upper rubber bush 500 and the right outer peripheral portion of the lower rubber bush 600 is increased, and the moment to rotate the end bolt 400 clockwise. And bending force is applied to the shock absorber A4. Thus, when bending force is added to shock absorber A4, the frictional force of the sliding part in shock absorber A4, such as the piston part of shock absorber A4, becomes large, and smooth expansion-contraction movement of shock absorber A4 is prevented. For this reason, if the bending force applied to the shock absorber A4 is excessive, the shock absorber A4 cannot exhibit its original performance, and the performance of the shock absorber A4 is impaired.

  Therefore, the present invention aims to provide a shock absorber that suppresses the performance from being impaired even when the shock absorber is attached in a state where the shaft is inclined with respect to the attachment shaft, and can exhibit the original performance. To do.

  The shock absorber according to claim 1, which solves the above-described problem, is attached to the outer periphery of the end bolt, and a pair of annular rubber bushes that sandwich the mounting portion of the vehicle, and a pair of washers that sandwich the pair of rubber bushes. Is provided. The rubber bush has an outer diameter gradually reduced toward at least one of one end or the other end in the axial direction toward the tip, and the axial direction toward the attachment side or washer side of the rubber bush It has a gap forming portion that forms a gap at a position overlapping the washer as viewed. For this reason, even if the shaft of the shock absorber is inclined with respect to the predetermined mounting shaft, it is possible to prevent an excessive bending force from being applied to the shock absorber due to excessive compression of a part in the circumferential direction of the rubber bush. .

  According to a second aspect of the present invention, in addition to the configuration of the first aspect, the gap forming portion is provided on the mounting portion side. For this reason, the bending force added to a buffer can be made small.

  According to a third aspect of the present invention, in addition to the configuration according to the first aspect, the gap forming portion is provided at both end portions in the axial direction of the rubber bush. For this reason, the bending force added to a buffer can be made very small.

  According to a fourth aspect of the present invention, in addition to the configuration of the first aspect, the gap forming portion is provided on the washer side. For this reason, when the shock absorber shaft is tilted with respect to a predetermined mounting shaft, a part of the rubber bush in the circumferential direction is excessively compressed while an excessive bending force is applied to the shock absorber while suppressing the tilt. Can be prevented.

  According to a fifth aspect of the present invention, in addition to the configuration according to any one of the first to fourth aspects, the outer peripheral surface of the gap forming portion is a tapered surface or a curved surface. For this reason, a clearance gap formation part can be formed easily.

  According to the shock absorber of the present invention, even when the shock absorber is attached in a state where the shaft is inclined with respect to the attachment shaft, the performance is prevented from being impaired, and the original performance can be exhibited.

It is the perspective view which simplified and showed the state which attached the shock absorber which concerns on one embodiment of this invention to the vehicle. It is the longitudinal cross-sectional view which expanded and showed a part of shock absorber which concerns on one embodiment of this invention. It is the longitudinal cross-sectional view which showed the state in which the axis | shaft of the shock absorber of FIG. 2 inclined with respect to the attachment axis | shaft. It is the longitudinal cross-sectional view which expanded the 1st modification of the buffer which concerns on one embodiment of this invention, and showed a part of buffer which concerns on the said modification. (A) is the longitudinal cross-sectional view which showed the 2nd modification of the buffer which concerns on one embodiment of this invention, and expanded and showed a part of buffer which concerns on the said modification. (B) is the longitudinal cross-sectional view which showed the state in which the axis | shaft of the buffer of (a) inclined with respect to the attachment axis | shaft. (A) is the longitudinal cross-sectional view which showed the 3rd modification of the buffer which concerns on one embodiment of this invention, and expanded and showed a part of buffer which concerns on the said modification. (B) is the longitudinal cross-sectional view which showed the state in which the axis | shaft of the buffer of (a) inclined with respect to the attachment axis | shaft. (A) is the longitudinal cross-sectional view which expanded and showed a part of conventional buffer. (B) is the longitudinal cross-sectional view which showed the state in which the axis | shaft of the buffer of (a) inclined with respect to the attachment axis | shaft.

  Embodiments of the present invention will be described below with reference to the drawings. The same reference numerals given throughout the several drawings indicate the same or corresponding parts.

  As shown in FIG. 1, a shock absorber A1 according to an embodiment of the present invention is interposed between a vehicle body B and a wheel W of a four-wheeled vehicle V. Although FIG. 1 shows a state in which the shock absorber A1 is attached to the front wheel of the four-wheeled vehicle V, it goes without saying that the shock absorber A1 may be attached to the rear wheel. Further, the shock absorber A1 may be used for a vehicle other than a four-wheeled vehicle.

  The shock absorber A1 includes a shock absorber body D having an outer shell 1 and a rod 2 inserted into the outer shell 1 so as to be movable in the axial direction, and a mounting member M (FIG. 2) for connecting the rod 2 to the vehicle body. And a bracket 3 for connecting the outer shell 1 to the axle of the wheel W. And if the impact by road surface unevenness | corrugation is input into the wheel W, the rod 2 will go in and out of the outer shell 1, and the buffer body D will expand-contract, and, thereby, buffer A1 will expand-contract.

  Since the configuration of the shock absorber body D is well known, detailed illustration thereof is omitted, but the shock absorber body D includes a cylinder provided inside the outer shell 1 and a piston slidably inserted into the cylinder. The lower end in FIG. 1 of the rod 2 is connected to the piston. In the cylinder, two chambers filled with a fluid such as hydraulic oil are formed. When the shock absorber A1 expands and contracts and the piston moves in the cylinder in the axial direction, a differential pressure is generated in the two chambers. Damping force that hinders expansion and contraction is generated.

  Further, a liquid reservoir chamber for storing liquid is formed between the outer shell 1 and the cylinder. The reservoir chamber communicates with the cylinder, and can compensate for a change in the cylinder volume corresponding to the rod volume entering and exiting the cylinder, or can compensate for a change in volume of the liquid in the cylinder due to a temperature change. As described above, the shock absorber A1 has a cylinder and an outer shell 1 that are arranged in double inside and outside, and is set to a double cylinder type. The cylinder and the outer shell 1 constitute a reservoir that stores liquid inside. But this is not the case.

  For example, the reservoir is a separate tank provided side by side on the outside of the cylinder, or a movable partition such as a free piston, bladder, or bellows that forms an inflatable / expandable air chamber in the cylinder. In the chamber, the change in volume of the liquid due to the change in volume in the cylinder and the change in temperature corresponding to the volume of the rod can be compensated. In such a case, the shock absorber A1 can be made into a single cylinder using the outer shell 1 as a cylinder. The shock absorber A1 is a single rod type, and the rod 2 extends from one side of the piston to the outside of the cylinder, but may be a double rod type, and the rod 2 may extend from both sides of the piston to the outside of the cylinder. Furthermore, although the shock absorber A1 is a hydraulic pressure shock absorber that uses fluid force, it may be a pneumatic pressure shock absorber or other shock absorber.

  Subsequently, as shown in FIG. 2, the attachment member M for attaching the shock absorber body D to the vehicle body B includes an end bolt 4 coaxially connected to the upper side of the rod 2 and a pair of upper and lower rubbers attached to the outer periphery of the end bolt 4. The bushes 5 and 6, a pair of upper and lower washers 7 and 8 sandwiching the rubber bushes 5 and 6, and a nut 9 that is screwed to the tip of the end bolt 4 are provided. In addition, the mounting portion b1 for mounting the shock absorber A1 in the vehicle body B has a plate shape, and the mounting portion b1 has a mounting hole b2 penetrating the mounting portion b1 in the thickness direction.

  The end bolt 4 includes a screw part 4a positioned at the end on the tip side that is the upper end in FIG. 2, an insertion part 4b coaxially connected to the lower side of the screw part 4a in FIG. 2, and the insertion part 4b in FIG. It has a stopper portion 4c which is connected to the lower end and located at the end. The outer periphery of the screw portion 4a is subjected to male screw processing, and the nut 9 can be screwed together. Moreover, the outer diameter of the insertion part 4b is more than the outer diameter of the screw part 4a, and is smaller than the diameter of the attachment hole b2. Therefore, in a state where the insertion portion 4b is inserted into the attachment hole b2, the inclination of the insertion portion 4b with respect to the shaft of the attachment hole b2 is allowed, and thus the shock absorber A1 can swing with respect to the attachment portion b1. Moreover, the outer diameter of the stopper part 4c is larger than the outer diameter of the insertion part 4b. That is, the outer peripheral portion of the stopper portion 4c protrudes radially outward from the insertion portion 4b.

  The rubber bushes 5 and 6 are made of an elastomer such as rubber or synthetic resin and have elasticity. Moreover, the rubber bushes 5 and 6 are annular, and each has a through-hole that allows the insertion portion 4b to be inserted therethrough. Further, the outer diameters of the rubber bushes 5 and 6 in the axial direction gradually decrease toward the tip. Further, the outer peripheral portions of the rubber bushes 5 and 6 are gradually thinned toward the outer peripheral end. More specifically, the rubber bushes 5 and 6 are both cylindrical cylindrical portions 50 and 60 and a pair of truncated cone-shaped gaps extending in the axial direction from both axial ends of the cylindrical portions 50 and 60. Forming portions 51, 52, 61, 62. Tapered surfaces 5a, 5b, 6a and 6b are formed on the outer circumferences of the truncated cone-shaped gap forming portions 51, 52, 61 and 62, respectively.

  The tapered surfaces 5a and 5b located at both axial ends of the rubber bush 5 on the upper side in FIG. 2 are inclined so as to approach each other toward the outer peripheral end. The taper surface 5a faces the lower surface of the upper washer 7, and a gap is formed therebetween. The taper surface 5b faces the upper surface of the mounting portion b1, and a gap is formed therebetween. The gaps overlap the upper washer 7 as viewed in the axial direction. Similarly, the tapered surfaces 6a and 6b located at both ends in the axial direction of the lower rubber bush 6 in FIG. 2 are inclined so as to approach each other toward the outer peripheral end. The tapered surface 6a faces the upper surface of the lower washer 8, a gap is formed between them, and the tapered surface 6b faces the lower surface of the mounting portion b1, and a gap is formed between them. . The gaps overlap with the lower washer 8 as viewed in the axial direction.

  The washers 7 and 8 are annular plates, and each has a through hole that allows the insertion portion 4b to be inserted therethrough. At least the inner diameter of the washer 8 on the stopper portion 4c side is smaller than the outer diameter of the stopper portion 4c. Therefore, the washer 8 is supported by the stopper portion 4c in a state where the washer 8 is mounted on the outer periphery of the insertion portion 4b. Then, the rubber bushes 5 and 6 and the washers 7 and 8 are prevented from moving toward the rod 2 beyond the stopper portion 4c.

  Then, the mounting portion b1 is sandwiched between the rubber bushings 5 and 6 attached to the outer periphery of the insertion portion 4b, the rubber bushings 5 and 6 are sandwiched between the washers 7 and 8, and the nut 9 is screwed into the screw portion 4a of the end bolt 4 by a predetermined amount. In FIG. 2, the rubber bush 5 is compressed between the washer 7 restricted by the nut 9 and the attachment portion b1, and the washer 8 restricted downward movement by the stopper portion 4c. The rubber bush 6 is compressed between the mounting portion b1 and the mounting portion b1. Therefore, the end bolt 4 and the vehicle body B are connected in a state where the mounting portion b1 is sandwiched between the pair of rubber bushes 5 and 6, whereby the shock absorber A1 and the vehicle body B are connected.

  As described above, in a state where the shock absorber A1 is attached to the vehicle, the rubber bushes 5 and 6 are pre-compressed even when no load is applied to the shock absorber A1, so that initial deflection is applied to the rubber bushes 5 and 6. It has become. And even if it is in the state where initial deflection was given to rubber bushes 5 and 6, between taper surfaces 5a and 6a and washers 7 and 8 of rubber bushes 5 and 6, taper surfaces 5b and 6b, and attachment part b1 The gap that can be made between and is not collapsed.

  FIG. 2 shows a state where the shock absorber A1 is attached to the vehicle body B so that the axis X of the shock absorber A1 overlaps the predetermined attachment shaft Y. In such a state, gaps formed on both axial sides of the rubber bushes 5 and 6 are formed annularly on the outer periphery of the gap forming portions 51, 52, 61 and 62, and toward the outer peripheral side of the rubber bushes 5 and 6. The vertical width of the gap increases as you go.

  Although not shown, a cylindrical collar to be attached to the outer periphery of the insertion portion 4b may be provided, and the rubber bushes 5 and 6 may be attached to the outer periphery of the collar. In this case, when the collar is supported by the stopper portion 4c and the nut 9 is abutted against the tip of the collar, it is easy to give the rubber bushes 5 and 6 a predetermined initial deflection. In addition, the method for giving the initial deflection to the rubber bushes 5 and 6 is not limited to the above, and can be changed as appropriate.

  Next, a method for attaching the shock absorber A1 to the vehicle body B using the attachment member M will be described. First, one washer 8 of the pair of washers 7 and 8 and one rubber bush 6 of the pair of rubber bushes 5 and 6 are mounted in this order on the outer periphery of the insertion portion 4 b of the end bolt 4. Next, the end bolt 4 is inserted into the mounting hole b2 from the tip, and the tip side of the end bolt 4 is projected into the vehicle interior. Then, the other rubber bush 5 and the other washer 7 are mounted in this order on the outer periphery of the insertion portion 4b of the end bolt 4 protruding into the vehicle interior. Finally, a nut 9 is screwed into the screw portion 4a of the end bolt 4, and the rubber bushes 5 and 6 are compressed by a predetermined amount to give initial deflection.

  Hereinafter, the operation of the shock absorber A1 according to the present embodiment will be described.

  As described above, when the shock absorber A1 is attached to the vehicle body B, it is necessary to incline the shaft X of the shock absorber A1 with respect to the predetermined attachment axis Y because of the attachment positions on the vehicle body side and the wheel side. However, the rubber bushes 5 and 6 are prevented from being excessively compressed due to the gaps formed on both sides of the rubber bushes 5 and 6 in the axial direction.

  Specifically, for example, when the shock absorber A1 is attached to the vehicle body B with the axis X of the shock absorber A1 tilted counterclockwise with respect to the attachment axis Y as shown in FIG. The left side of the annular gap formed between the rubber bush 5 and the mounting part b1 is crushed, and the right side of the buffering gap formed between the lower rubber bush 6 and the mounting part b1 is crushed. And even if a part in the circumferential direction of the gap on the mounting portion b1 side is crushed in this way, the gap formed on the outer periphery of the rubber bushes 5 and 6 between the rubber bushes 5 and 6 and the washers 7 and 8 Escape to.

  For this reason, even if the shock absorber A1 is mounted in an inclined state, the outer peripheral side of a part of the rubber bushes 5 and 6 in the circumferential direction is not excessively compressed, and the rubber bushes 5 and 6 have a circumferential direction. It can prevent that the amount of compression of a part becomes excessive and an excessive bending force is added to buffer A1. Since an excessive bending force does not act on the shock absorber A1, the frictional force of the sliding portion in the shock absorber A1, such as the piston portion of the shock absorber A1, increases due to the input of the bending force, and the shock absorber A1 is smooth. Telescopic movement is not hindered. Furthermore, it is possible to reduce the load applied to the seal that seals the outer periphery of the rod 2 and prevents the liquid inside the shock absorber A1 from flowing out.

  In addition, when a lateral force acts on the shock absorber A1 when the vehicle travels and the shock absorber A1 swings in response to the lateral force, an annular gap formed on the outer periphery of the gap forming portions 51, 52, 61, 62 Until a part of the circumferential direction is crushed, the shock absorber A1 can swing without compressing the outer peripheral ends of the rubber bushes 5 and 6. That is, since the lateral force can be canceled by the swinging of the shock absorber A1, it is possible to prevent an excessive bending force from being applied to the shock absorber A1 due to the lateral force input when the vehicle travels.

  Further, when the shock absorber A1 is mounted in a state where the axis X is inclined with respect to the mounting axis Y, even if a lateral force is input in a direction that promotes the inclination of the axis X during vehicle travel, the rubber bush 5, The rubber bushes 5 and 6 can be elastically deformed because no excessively compressed portion is formed on the outer peripheral portion of the rubber 6. Therefore, even if the shock absorber A1 is attached in a state where the axis X is inclined with respect to the attachment shaft Y, an excessive bending force is not applied to the shock absorber A1 due to the lateral force input when the vehicle travels.

  Also, for vibrations input in the axial direction of the shock absorber A1 when the vehicle travels, even if the shock absorber A1 is mounted with the shaft X overlapping the mounting shaft Y, the shaft X is the mounting shaft. Even when the shock absorber A1 is attached in a state tilted with respect to Y, the rubber bushes 5 and 6 expand and contract, and exhibit elasticity corresponding to the amount of compression.

  Hereinafter, the effect of buffer A1 concerning this embodiment is explained.

  In the shock absorber A1, the outer peripheral surfaces of the gap forming portions 51, 52, 61, 62 are tapered surfaces 5a, 5b, 6a, 6b. Then, it is easy to gradually reduce the outer diameter of the gap forming portions 51, 52, 61, 62 toward the tip, and the gap forming portions 51, 52, 61, 62 can be easily formed. As shown in FIG. 4, the same effect can be obtained even when the rubber bushes 5 and 6 are formed in an elliptical shape and the outer peripheral surfaces of the gap forming portions 51, 52, 61 and 62 are curved surfaces. Thus, the shapes of the gap forming portions 51, 52, 61, 62 can be changed as appropriate.

  Further, in the shock absorber A1, gap forming portions 51, 52, 61, 62 are provided at both end portions of the rubber bushes 5, 6 in the axial direction. For this reason, gaps are formed between the rubber bushes 5 and 6 and the attachment portions b1 and the washers 7 and 8, respectively, and the rubber bushes 5 and 6 escape to these gaps. Therefore, even if the inclination of the shaft X with respect to the mounting shaft Y becomes large, it is possible to prevent excessive compression of the rubber bushes 5 and 6, particularly at the outer peripheral portion, and to apply excessive bending force to the shock absorber A1. Can be surely prevented.

  The gap forming portions 51, 52, 61, 62 may be provided only at one end portion in the axial direction of the rubber bushes 5, 6. Specifically, for example, FIG. 5A shows a shock absorber A2 including rubber bushes 5A and 6A having gap forming portions 52 and 62 only at the end on the mounting portion b1 side. FIG. 6A shows a shock absorber A3 provided with rubber bushes 5B and 6B having gap forming portions 51 and 61 only at the end portions on the side of the washers 7 and 8.

  In the shock absorber A2 shown in FIG. 5, as shown in FIG. 5 (b), the rubber bushes 5, 6 until a part of the gap in the circumferential direction formed on the mounting part b1 side of the gap forming parts 52, 62 is crushed. The shock absorber A2 can be swung without greatly changing the shape. On the other hand, in the shock absorber A3 shown in FIG. 6, as shown in FIG. 6 (b), the rubber is formed until a part in the circumferential direction of the gap formed on the washer 7 and 8 side of the gap forming portions 51 and 61 is crushed. The outer peripheral portions of the bushes 5 and 6 can be elastically deformed toward the washers 7 and 8 without being crushed. Therefore, even in the shock absorbers A2 and A3, it is possible to suppress the bending force applied to the shock absorbers A2 and A3 from becoming excessive. Further, when the gap forming portions 52 and 62 are provided on the mounting portion b1 side like the shock absorbers A1 and A2, the deformation amount of the rubber bushes 5, 5A, 6, 6A when the shock absorbers A1 and A2 are swung is reduced. Since it is small, the bending force concerning buffer A1, A2 can be made smaller. Further, when the gap forming portions 51 and 61 are provided only on the washers 7 and 8 side as in the shock absorber A3, the bending force applied to the shock absorber A3 is prevented from being excessive, and compared with the shock absorbers A1 and A2. Thus, the swinging of the shock absorber A3 can be suppressed.

  Further, any rubber bush 6, 6A, 6B may be combined with any rubber bush 5, 5A, 5B. For example, as a pair of rubber bushes, the rubber bush 5 and the rubber bush 6A may be used in combination. The bush 5A and the rubber bush 6B may be used in combination. These changes are possible regardless of the shape of the outer peripheral surface of the gap forming portions 51, 52, 61, 62.

  The shock absorber A1 is attached to the outer shell 1, the rod 2 inserted into the outer shell 1 so as to be movable in the axial direction, the end bolt 4 connected to the rod 2, and the outer periphery of the end bolt 4. And a pair of annular rubber bushings 5 and 6 that sandwich the attachment portion b1 of the four-wheel automobile (vehicle) V, and a pair of washers 7 and 8 that sandwich the pair of rubber bushings 5 and 6. The rubber bushes 5 and 6 are gradually reduced in outer diameter toward both ends in the axial direction so as to form gaps on the mounting portions b1 side or the washers 7 and 8 side of the rubber bushes 5 and 6. It has formation parts 51, 52, 61, 62. And the said clearance gap is formed in the position which overlaps with the washers 7 and 8 by the axial view.

  According to the above configuration, even if the shock absorber A1 is attached to the vehicle with the shaft X tilted with respect to the attachment shaft Y, the circumferential direction of the rubber bushes 500 and 600 is different from that of the conventional shock absorber A4. It is possible to prevent the amount of compression from becoming excessive especially on the outer peripheral side of the portion. Therefore, an excessive bending force is not added to the shock absorber A1, and it is possible to suppress the performance of the shock absorber A1 from being damaged by the bending force, and the shock absorber A1 can exhibit its original performance. For this reason, when shock absorber A1 is mounted in vehicles, such as four-wheeled motor vehicle V, the riding comfort of vehicles can be made favorable.

  Further, when the shaft X is inclined with respect to the mounting shaft Y as in the conventional shock absorber A4 and the rubber bushes 500 and 600 have a portion where the compression amount is excessive, the spring constant is high in the portion where the compression amount is large. It becomes difficult to compress (hard). For this reason, when the shock absorber A4 is attached to the vehicle in such a state, it is difficult for the rubber bushes 500 and 600 to absorb vibrations input during vehicle travel. On the other hand, in the shock absorber A1, even if the shaft X is mounted in a state of being inclined with respect to the mounting shaft Y, the rubber bushes 5 and 6 do not have excessively compressed portions. Therefore, the vibrations input when the vehicle travels can be absorbed by the rubber bushes 5 and 6. Also from this fact, when the shock absorber A1 is mounted on a vehicle, the ride comfort of the vehicle can be improved.

  These effects can be obtained even in the shock absorbers A2 and A3 including the rubber bushes 5A, 6A, 5B, and 6B in which the gap forming portions 51, 52, 61, and 62 are formed only in one of the axial directions. Even when the outer peripheral surfaces of the portions 51, 52, 61, 62 are curved surfaces, the same is obtained.

  In the shock absorber A1, the end bolt 4 is connected to the rod 2, but may be connected to the outer shell 1. Further, the shock absorber A1 is connected to the vehicle body B using the end bolt 4, but may be connected to a knuckle or an arm that supports the wheel W using the end bolt 4. Further, in the shock absorber A1, the rubber bushes 5 and 6 are in contact with the mounting portion b1, but a washer may be interposed between them, and the mounting portion b1 side is provided between the washer and the rubber bushing 5 and 6. A gap may be formed by the gap forming portions 52 and 62. These changes are also possible in the shock absorbers A2 and A3, and can be made regardless of the shape of the gap forming portions 51, 52, 61, and 62.

  The preferred embodiments of the present invention have been described above in detail, but modifications, changes and modifications can be made without departing from the scope of the claims.

A1, A2, A3 ... shock absorber, b1 ... mounting part, V ... four-wheeled vehicle (vehicle), 1 ... outer shell, 2 ... rod, 4 ... end bolt, 5 , 5A, 5B, 6, 6A, 6B ... Rubber bush, 5a, 5b, 6a, 6b ... Tapered surface or curved surface, 7, 8 ... Washer, 51, 52, 61, 62 ... Gap forming part

Claims (5)

An outer shell and a rod inserted in the outer shell so as to be movable in the axial direction;
An end bolt connected to at least one of the outer shell and the rod;
A pair of annular rubber bushes that are mounted on the outer periphery of the end bolt and sandwich the mounting portion of the vehicle;
A pair of washers sandwiching the pair of rubber bushes,
The rubber bush has an outer diameter that gradually decreases toward one end or the other end in the axial direction toward the tip of the one end or the other end. Or having a gap forming part for forming a gap on at least one of the washer side,
The said clearance gap is formed in the position which overlaps with the said washer by axial direction view. The shock absorber characterized by the above-mentioned. The shock absorber according to claim 1, wherein the gap forming portion is provided on a mounting portion side. The shock absorber according to claim 1, wherein the gap forming portion is provided at both ends of the rubber bush in the axial direction. The shock absorber according to claim 1, wherein the gap forming portion is provided on the washer side. The shock absorber according to any one of claims 1 to 4, wherein an outer peripheral surface of the gap forming portion is a tapered surface or a curved surface.