JP2001271864A - Bound stopper - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve buckling resistance in compressive deformation, even if the rate of height (axial length) to an outer diameter is large in a bound stopper. SOLUTION: This bound stopper 10 is provided with first and second annular recessed parts 13 and 16, arranged coaxially at two parts between both axial ends on the outer peripheral surface side of a cylindrical body 11 formed of a urethane foam resin material. The axial height (whole length) of the body 11 is 1.7 times as large as the maximum outer diameter of the body 11, and the total axial length of the first and second recessed parts 13 and 16 is 0.5 times or longer than the height.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shock absorber which is externally mounted on an absorber rod of a shock absorber constituting a vehicle suspension and elastically restricts an operation stroke of the shock absorber.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 4, for example, this kind of bound stopper is provided at a plurality of locations between both ends in the axial direction on the outer peripheral surface side of a cylindrical main body 1 formed of an elastic material such as rubber. An annular concave portion 2 is provided coaxially, and the outer peripheral surface is bellows in the axial direction. The cylindrical main body 1 is externally arranged on an absorber rod 5 of a shock absorber 4, and a large-diameter portion thereof is formed of an absorber rod 5. Is fixed to a mounting bracket 6 on the vehicle body that supports the vehicle body in vibration isolation. Thereby, the bound stopper is arranged between the mounting bracket 6 and the shock absorber 4, and when the shock absorber 4 is operated, it is compressed and deformed in the axial direction between the two to elastically limit the operation stroke of the shock absorber. .

[0003]

By the way, in the above-mentioned bound stopper, by increasing the height H (length in the axial direction), even if the coil of the shock absorber 4 is slightly bent by the roll of the vehicle, the shock absorber can be used. When the vehicle hits the cylindrical main body 1, the vehicle does not roll due to the rigidity of the bound stopper, so that the stability of the vehicle can be improved. However, by increasing the height of the bound stopper, there is a problem that the buckling resistance during compression deformation of the bound stopper is deteriorated, and the bound stopper is likely to fall down. For this, the outer diameter φD may be increased according to the height, but since the mounting range of the bound stopper is limited,
Larger outer diameters are not allowed. In addition, it is conceivable to provide a cylindrical cup with a restrictive shape extending in the axial direction on the outer peripheral side of the bound stopper. However, there is a limitation in mounting space, and furthermore, a problem of generating abnormal noise due to contact between the cup and the bound stopper. There is also.

[0004] The present invention is intended to solve the above-mentioned problem, and even if the ratio of the height (the length in the axial direction) to the outer diameter is increased, the bound stopper has good buckling resistance during compression deformation. The purpose is to provide.

[0005]

In order to achieve the above object, a structural feature of the present invention according to the first aspect of the present invention is that a shock absorber is externally arranged on an absorber rod of a shock absorber constituting a vehicle suspension, and a shock absorber is provided. In a cylindrical bound stopper for elastically limiting an operation stroke of an absorber, an annular first coaxial ring is formed at two locations between both ends in the axial direction on an outer peripheral surface of a cylindrical main body formed of a urethane foam resin material. And the second concave portion, the axial height of the main body is 1.7 times or more the maximum outer diameter of the main body, and the total axial length of the first and second concave portions is It is at least 0.5 times the height.

[0006] The ratio of the height of the cylindrical body to the maximum outer diameter is 1.7 times or more, but preferably 1.7 to 2.2.
The range is twice as large. The ratio of the total length of the first and second recesses in the axial direction to the height is 0.5 times or more, but preferably 0.5 to 0.7 times.

[0007] In the first aspect of the present invention, the height of the cylindrical main body in the axial direction is 1.7 times or more the maximum outer diameter of the main body. On the other hand, the first coaxial ring is provided at two places between both ends in the axial direction.
And the second concave portion is provided, and the total length of the first and second concave portions in the axial direction is 0.5 times or more the height.
Thus, when compressive deformation is applied to the bound stopper due to an axial load from the shock absorber, the bound stopper is smoothly deformed in the axial direction at the first and second concave positions and comes into contact with the absorber rod. , And can be satisfactorily deformed using the absorber rod as a guide. In the above-mentioned bound stopper, an annular rigid ring may be fitted coaxially on the outer peripheral surface between the first and second concave portions.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. FIGS. 1 and 2 show an embodiment in which a shock absorber constituting a vehicle suspension according to the embodiment is externally arranged on an absorber rod. FIGS. 3A and 3B are vertical cross-sectional views at an axial position, respectively, showing a bound stopper and a mounted state of the bound stopper. The bound stopper 10 is a cylindrical main body 11 made of urethane foam resin.
And a rigid ring 25 attached to the main body 11. The urethane foam resin is formed, for example, by a combination of a liquid A mainly composed of polyether polyol, a liquid B mainly composed of polyisocyanate, and a foaming material.

The main body 11 has a substantially cylindrical shape (having a height (length in the axial direction) H) that is rotationally symmetric about the axis, and has a substantially straight shaft hole 21 at the center position. The outer peripheral surface of the main body 11 has a cylindrical large-diameter portion 12 having an outer diameter φD, a first concave portion 13, and a cylindrical intermediate portion 14 extending from one axial end (the upper end in the drawing) to the other end (the lower end in the drawing). , The second concave portion 16 and the small diameter portion 17 are sequentially arranged.

The large-diameter portion 12 has an annular concave portion 12a whose one axial end is coaxially cut off in a circular shape on one end surface, and further extends radially from the outer peripheral side of the annular concave portion 12a to reach the lower end of the outer peripheral surface. 12b is provided. Groove 12b
Functions as an air vent passage or the like when the bound stopper 10 is mounted on a later-described bound stopper mounting bracket 33. The intermediate portion 14 has a longer axial length and a smaller outer diameter than the large-diameter portion 12, and has a first intermediate portion 14 a in order from the large-diameter portion 12 side, and is slightly smaller than the first intermediate portion 14 a. And a second intermediate portion 14b having a small diameter, and an annular mounting concave portion 15 is formed coaxially across the two intermediate portions 14a and 14b at the boundary between the two intermediate portions 14a and 14b. A rigid ring 25 made of an annular polyamide resin is fitted into the mounting recess 15. The rigid ring 25 hardens the spring characteristics when the amount of deformation of the bound stopper 10 increases, and makes the load-deflection characteristics of the bound stopper 10 non-linear. The small diameter portion 17 is the large diameter portion 1
2, the outer diameter is smaller than the second intermediate portion 14b, and the other end side is a conical inclined portion 17a inclined at approximately 45 ° toward the axis. It has become. It should be noted that the rigid ring may be made of metal.

As shown in the sectional view of FIG. 1, the first concave portion 13 has an arc shape in which an outer edge line connecting the large diameter portion 12 and the intermediate portion 14 is concave toward the axis, and has an axial length. The length L1 is approximately three times the axial length of the large diameter portion 12. Similarly to the first concave portion 13, the second concave portion 16 has an arc shape in which an outer edge line connecting the intermediate portion 14 and the small-diameter portion 17 is concave toward the axial center, and the axial length L2 is the intermediate portion. 14
Is substantially equal to the length in the axial direction.

The shaft hole 21 is substantially straight from one end to a position corresponding to the bottom S closest to the axial center of the outer edge of the second recess 16, and further has a substantially boundary with the small diameter portion 17 of the second recess 16. The end is an enlarged diameter portion 22 that is slightly inclined toward the small diameter portion 17 and is enlarged in diameter. The portion of the shaft hole 21 corresponding to the mounting range of the rigid ring 25 is coaxially slightly recessed in the radial direction, and is formed in a mountain-shaped recessed portion 23 whose cross-sectional shape peaks at an intermediate position in the axial direction. The small-diameter portion 17 is coaxially recessed in the radial direction, and is formed in a mountain-shaped recess 24 having a cross-sectional shape that peaks at an intermediate position in the axial direction of the small-diameter portion. It has a shape.

Here, in the above-described bound stopper 10, the relationship between the height H and the outer diameter φD of the large-diameter portion 12, which is the maximum outer diameter, is expressed by the following equation (1). The axial lengths L1 and L2 and the height H of the two concave portions 13 and 16
Is as shown in Equation 2. However, H /
About φD, it is desirable to be up to about 2.2.
(L1 + L2) / H is also preferably up to about 0.7.

[0014]

## EQU1 ## H / φD ≧ 1.7

[0015]

(L1 + L2) /H≧0.5

As shown in FIG. 2, the bound stopper 10 is externally inserted into an absorber rod 32 of a shock absorber 31 in a shaft hole 21 so that a large-diameter portion 12 supports the absorber rod 32 in a vibration-proof manner on the vehicle body side. It is press-fitted and fixed to a cup 34 which is a bottomed cylindrical fitting fixed to a bound stopper mounting fitting 33 on the vehicle body side. Thereby, the bound stopper 10 is disposed between the bound stopper mounting bracket 33 and the shock absorber 31.
When the shock absorber 31 is operated, it is compressed and deformed in the axial direction between the mounting bracket 33 and the shock absorber 31 to elastically limit the operation stroke of the shock absorber 31.

In the embodiment configured as described above, the height H is 1.7 times or more the outer diameter φD of the large-diameter portion 12 having the maximum outer diameter. Also, the buckling resistance of the bound stopper 10 can be improved by setting the axial lengths L1 and L2 of the first and second concave portions 13 and 16 to 0.5 times or more the height H. it can. That is, when compressive deformation is applied to the bound stopper 10 by an axial load from the shock absorber 31, the bound stopper 10 is smoothly deformed toward the axial center at the positions of the first and second concave portions 13 and 16, and the absorber rod is deformed. 32 and the absorber rod 3
2 is used as a guide for good deformation. Therefore, the buckling resistance of the bound stopper 10 is improved, and the side stopper can be reliably prevented from falling down.

As a result, even if the coil of the shock absorber 31 is slightly bent by the roll of the vehicle, the shock absorber 31 immediately hits the bound stopper 10, so that even if the vehicle tries to roll,
Does not roll due to the stiffness of the vehicle, thus increasing the stability of the vehicle. In addition, there is no increase in the radial mounting space for the bound stopper 10. Further, since a cup extending long in the axial direction is not required, generation of abnormal noise due to contact between the bound stopper 10 and the cup can be avoided.

The height H, the outer diameter φD of the large diameter portion 12 and the first and second concave portions 1
FIG. 3 is a graph showing the results of inspection of the buckling resistance of specific examples in which the axial lengths L1 and L2 of 3, 16 are variously combined. In FIG. 3, the mark ○ indicates that the buckling resistance is good, and the mark X indicates that the buckling resistance is poor. As is clear from FIG. 3, the height H is 1.7 times the outer diameter φD of the large diameter portion 12.
Even if the bound stopper is more than twice as tall,
By setting the sum of the axial lengths L1 and L2 of the second concave portions 13 and 16 and the height H to be 0.5 times or more (the shaded area in the drawing), the buckling resistance is improved. If it is lower than .5 times, the buckling resistance becomes poor.

The bound stopper shown in the above embodiment can be used not only for vehicles but also for other similar uses. In addition, the bound stopper described in the above embodiment is an example, and can be implemented in various forms without departing from the gist of the present invention.

[0021]

According to the first aspect of the present invention, there is provided a bound stopper having a very high height such that the axial height of the cylindrical body is at least 1.7 times the maximum outer diameter of the cylindrical body. Also, by making the total length of the first and second recesses in the axial direction at least 0.5 times the height, the buckling resistance of the bound stopper when an axial load is applied from the shock absorber. The properties can be improved, and the side-down can be reliably prevented.
As a result, even if the coil of the shock absorber slightly bends due to the roll of the vehicle, the stopper immediately hits, and even if the vehicle tries to roll, it does not roll due to the rigidity of the stopper, and the stability of the vehicle can be improved. Moreover, the mounting space for the radial direction of the bound stopper is not increased, and the generation of abnormal noise can be avoided. In addition, by fitting an annular rigid ring coaxially around the outer peripheral surface between the first and second concave portions, the load-deflection characteristics of the bound stopper can be made more nonlinear, and the riding comfort of the vehicle can be improved.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a bound stopper according to an embodiment of the present invention.

FIG. 2 is a vertical cross-sectional view showing a state where the shock absorber of the bound stopper is mounted on an absorber rod.

FIG. 3 is a graph showing the relationship between the shape of a bound stopper and buckling resistance.

FIG. 4 is a longitudinal sectional view showing a conventional bound stopper.

[Explanation of symbols]

10: bound stopper, 11: main body, 12: large diameter part,
13: first concave portion, 14: middle portion, 16: second concave portion,
17: small diameter portion, 21: shaft hole, 25: rigid ring.

Claims (2)

[Claims] 1. A cylindrical bound stopper externally arranged on an absorber rod of a shock absorber constituting a vehicle suspension and elastically restricting an operation stroke of the shock absorber. Coaxial annular first portion at two locations between both ends in the axial direction on the outer peripheral surface of the
And a second recess, wherein the height of the main body in the axial direction is 1.7 times or more the maximum outer diameter of the main body, and the total of the first and second recesses in the axial direction is provided. A bound stopper having a length not less than 0.5 times the height. 2. The bound stopper according to claim 1, wherein an annular rigid ring is coaxially fitted on an outer peripheral surface between the first and second concave portions.