JP7202139B2 - Buffer and buffer installation structure - Google Patents

Description

TECHNICAL FIELD The present invention relates to improvements in shock absorbers and shock absorber installation structures .

Conventionally, a shock absorber includes a cylinder, a piston slidably inserted into the cylinder, and a piston rod connected to the piston and having one end protruding outside the cylinder. damping force by giving resistance to the flow of liquid such as hydraulic oil that is generated when moving.

Such a hydraulic shock absorber consists of an annular rod guide attached to one end of a cylinder and through which the piston rod passes through the center, and an annular seal member attached to the rod guide and in sliding contact with the outer circumference of the piston rod. and (for example, Patent Document 1).

The piston rod moves axially in the cylinder while being supported by the rod guide and the piston. Further, when the piston rod is withdrawn from the cylinder, the sealing member scrapes off the liquid adhering to the outer periphery of the piston rod to prevent the liquid in the cylinder from leaking out of the cylinder. At this time, a thin liquid film is formed on the outer periphery of the piston rod.

Japanese Patent Application Laid-Open No. 2013-194832

Depending on how the shock absorber is installed, such as when the shock absorber is attached to the vehicle with the central axis of the shock absorber tilted with respect to the vertical line, lateral forces act on the shock absorber from various directions in the front, rear, left, and right directions. I have something to do. When the shock absorber receives such a lateral force, the clearance (backlash) between the piston rod and the rod guide causes backlash vibration. may become stable.

This is because the lateral force that the rod guide receives from the piston rod when backlash vibration occurs in the piston rod changes in all directions, front, rear, left, and right across the zero lateral force, as shown in FIG. This is because under such circumstances, the pressure (surface pressure) on the contact surface between the piston rod and the seal member becomes unstable.

Accordingly, the present invention has been devised to solve such problems, and provides a shock absorber and a shock absorber capable of suppressing the thickness of the liquid film formed on the outer circumference of the piston rod from becoming unstable. The purpose is to provide an installation structure .

A shock absorber installation structure that solves the above problems consists of a rod guide that is attached to the cylinder and supports the piston rod so as to be slidable in the axial direction, and a seal member that is attached to the rod guide and seals the outer circumference of the piston rod. , and a biasing member that applies a lateral force to the piston rod in one direction. gives a lateral force to the piston rod in the direction in which the lateral force input to the rod guide gathers.

According to the above configuration, the biasing member presses the piston rod in one direction on the inner circumference of the rod guide, thereby preventing the occurrence of backlash vibration due to the clearance (backlash) between the piston rod and the rod guide. As a result, the thickness of the liquid film formed by the sealing member on the outer periphery of the piston rod is suppressed from becoming unstable.

A shock absorber according to another invention for solving the above problems comprises a rod guide attached to a cylinder and supporting the piston rod so as to be slidable in the axial direction; A sealing member and a biasing member that applies a lateral force to the piston rod in one direction are provided. The biasing member includes an annular case portion that is fitted to the inner periphery of the cylinder and a slider that is in sliding contact with the outer periphery of the piston rod. , a spring interposed in a compressed state between the case portion and the slider, or an annular case portion fitted to the outer periphery of the piston rod, and a slider in sliding contact with the inner periphery of the cylinder. , and a spring interposed in a compressed state between the case portion and the slider . According to these configurations, the biasing member presses the piston rod in one direction on the inner circumference of the rod guide, thereby preventing the occurrence of backlash vibration due to the clearance (backlash) between the piston rod and the rod guide. As a result, the thickness of the liquid film formed by the sealing member on the outer periphery of the piston rod is suppressed from becoming unstable. In addition, the configuration for applying a lateral force to the piston rod in one direction by the biasing member can be facilitated.

Furthermore, in such a shock absorber of another invention , the case part has elasticity and is preferably compressed between a stopper provided on the outer periphery of the piston rod and the rod guide when the shock absorber is fully extended. According to this configuration, the case portion can be used as a cushion rubber for absorbing the impact at the time of maximum extension. Therefore, even if the urging member is provided, the length of the shock absorber in the axial direction can be prevented from increasing, and the mountability of the shock absorber can be improved.

A shock absorber according to still another invention for solving the above problems comprises a rod guide attached to a cylinder and supporting the piston rod so as to be slidable in the axial direction; and a biasing member that applies a lateral force to the piston rod in one direction. and an annular slider fitted to the inner periphery of the rubber member and slidably contacting the outer periphery of the piston rod; It has a rubber member including an outwardly protruding projection, and an annular slider that fits on the outer periphery of the rubber member and is in sliding contact with the inner periphery of the cylinder . In these configurations as well, the piston rod is pressed in one direction on the inner periphery of the rod guide by the biasing member, thereby preventing the occurrence of backlash vibration due to the clearance (backlash) between the piston rod and the rod guide. As a result, the thickness of the liquid film formed by the sealing member on the outer periphery of the piston rod is suppressed from becoming unstable. In addition, the configuration for applying a lateral force to the piston rod in one direction by the biasing member can be facilitated.

A shock absorber according to another invention for solving the above-mentioned problems comprises a rod guide attached to a cylinder and supporting the piston rod slidably in the axial direction, and a rod guide attached to the rod guide to seal the outer circumference of the piston rod. The piston rod includes a sealing member and a biasing member that applies a lateral force to the piston rod in one direction . A biasing member is provided between the lid and the bushing to apply a lateral force to the piston rod through the bushing . According to this configuration, the biasing member presses the piston rod in one direction on the inner circumference of the rod guide, thereby preventing the occurrence of backlash vibration due to the clearance (backlash) between the piston rod and the rod guide. As a result, the thickness of the liquid film formed by the sealing member on the outer periphery of the piston rod is suppressed from becoming unstable. Moreover, since the slider of the biasing member can be omitted, the number of parts of the shock absorber can be reduced.

According to the shock absorber and the shock absorber installation structure of the present invention, it is possible to suppress the thickness of the liquid film formed on the outer circumference of the piston rod from becoming unstable.

1 is a longitudinal sectional view showing a shock absorber according to an embodiment of the invention; FIG. (a) is a cross-sectional view showing a state in which an urging member is removed from the shock absorber according to the embodiment of the present invention. (b) is a longitudinal sectional view of the biasing member. FIG. 4 is a distribution diagram of the lateral force received by the rod guide when the vehicle equipped with the shock absorber according to the embodiment of the present invention is running; FIG. 10 is a longitudinal cross-sectional view showing a first modification of the biasing member in the damper according to the embodiment of the present invention and showing a portion of the damper including the modified portion; FIG. 11 is a cross-sectional view showing a second modification of the biasing member in the shock absorber according to the embodiment of the present invention, showing a state in which the biasing member is removed from the shock absorber; FIG. 11 is a cross-sectional view showing a third modification of the biasing member in the shock absorber according to the embodiment of the present invention, and showing a state in which the biasing member is removed from the shock absorber; FIG. 10 is a vertical cross-sectional view showing a fourth modification of the biasing member in the damper according to the embodiment of the present invention and showing a portion of the damper including the modified portion. FIG. 10 is a distribution diagram of lateral force received by a rod guide when a vehicle equipped with a conventional shock absorber is running.

A shock absorber according to an embodiment of the present invention will be described below with reference to the drawings. The same reference numerals throughout the several drawings indicate the same or corresponding parts.

A shock absorber D according to one embodiment of the present invention shown in FIG. 1 is interposed between a vehicle body and an axle of a vehicle such as an automobile. In the following description, for convenience of explanation, unless otherwise specified, the upper and lower sides of the shock absorber D attached to the vehicle body (mounted state) are simply referred to as "upper" and "lower." In addition, in the shock absorber D in the attached state, the direction facing the front of the vehicle body is "front", the direction facing the rear of the vehicle body is "rear", the direction facing the left side of the vehicle body is "left", and the direction facing the right side of the vehicle body is " Right.

Next, a specific configuration of the shock absorber D according to this embodiment will be described. As shown in FIG. 1, the shock absorber D includes a cylinder 1, an outer cylinder 10 provided on the outer circumference of the cylinder 1, a piston 2 slidably inserted into the cylinder 1, and a tip of the piston 2. It is provided with a piston rod 3 which is connected and whose end protrudes out of the cylinder 1 .

The end of the piston rod 3 also protrudes outside the outer cylinder 10, and a bracket (not shown) is fixed to the end of the piston rod 3. As shown in FIG. Then, the piston rod 3 is connected to the vehicle body via the above-described bracket with its end directed upward.

On the other hand, the lower end of the outer cylinder 10 located on the side opposite to the side from which the piston rod 3 protrudes is closed with a bottom cap 11, and a bracket (not shown) is fixed to the bottom cap 11. . The outer cylinder 10 is connected to the axle via the bracket. Since the cylinder 1 is fixed inside the outer cylinder 10, it can be said that the cylinder 1 is also connected to the axle.

In this way, the shock absorber D is interposed between the vehicle body and the axle with the piston rod 3 facing upward (toward the vehicle body) and the cylinder 1 and outer cylinder 10 facing downward (toward the wheel). When the vehicle travels on an uneven road surface and the wheels vibrate up and down with respect to the vehicle body, the piston rod 3 moves in and out of the cylinder 1, the shock absorber D expands and contracts, and the piston 2 moves up and down in the cylinder 1. move (axially).

In the shock absorber D, the upper end of the cylinder 1 is fitted with an annular rod guide 4 through which the piston rod 3 passes through the center. The rod guide 4 includes a fitting portion 40a fitted to the cylinder 1, and a large diameter portion 40b connected to the upper side of the fitting portion 40a and extending radially outward from the cylinder 1 toward the outer cylinder 10 side. and an annular bushing 41 that fits into the inner periphery of the lid portion 40 and is in sliding contact with the outer periphery of the piston rod 3 .

A piston rod 3 is supported by the rod guide 4 so as to be slidable in the axial direction. As described above, in this embodiment, the portion (cover portion 40) of the rod guide 4 that is fitted to the cylinder 1 and the portion (bush 41) that is in sliding contact with the piston rod 3 are separately formed and integrated by fitting. has been made However, the lid portion 40 and the bushing 41 may be integrally formed as one component.

Moreover, in the shock absorber D, an annular seal member 5 is laminated on the upper side of the rod guide 4 . The seal member 5 includes a dust lip 5a that slides on the outer periphery of the piston rod 3 to prevent foreign matter from entering the cylinder 1, and an oil lip that slides on the outer periphery of the piston rod 3 to prevent the liquid in the cylinder 1 from flowing out. 5b and an outer peripheral seal portion 5c that seals between the rod guide 4 and the outer cylinder 10 to prevent the liquid in the cylinder 1 and the outer cylinder 10 from leaking out.

That is, the upper ends of the cylinder 1 and the outer cylinder 10 are liquid-tightly closed by the rod guide 4 and the seal member 5 . On the other hand, the lower end of the outer cylinder 10 is liquid-tightly closed by the aforementioned bottom cap 11 . Thus, the inside of the outer cylinder 10 is a closed space. A liquid such as hydraulic oil and a gas such as air or nitrogen gas are enclosed in an outer cylinder 10 including the inside of the cylinder 1 .

More specifically, the cylinder 1 is filled with a liquid, and the inside of the cylinder 1 is divided by the piston 2 into an upper expansion side chamber L1 and a lower compression side chamber L2. On the other hand, a cylindrical gap between the cylinder 1 and the outer cylinder 10 is a reservoir chamber R, in which liquid is stored and gas is sealed above the liquid surface. . A valve case 6 is fitted to the lower end of the cylinder 1, and the valve case 6 partitions the reservoir chamber R and the compression side chamber L2.

The piston 2 is formed with an expansion side passage 2a and a compression side passage 2b that communicate the expansion side chamber L1 and the compression side chamber L2. Furthermore, under the piston 2, a growth side valve 20 for opening and closing the growth side passage 2a is laminated, and above the piston 2, a compression side valve 21 for opening and closing the compression side passage 2b is laminated.

The expansion side valve 20 opens when the shock absorber D is extended to provide resistance to the flow of liquid from the expansion side chamber L1 to the compression side chamber L2 in the expansion side passage 2a, but when the shock absorber D is contracted, the expansion side passage 2a is closed. maintained in condition. On the other hand, the compression-side valve 21 opens when the shock absorber D contracts to allow the liquid to flow from the compression-side chamber L2 to the expansion-side chamber L1 in the compression-side passage 2b, but closes the compression-side passage 2b when the shock absorber D expands. maintained at

Further, the valve case 6 is formed with a suction passage 6a and a discharge passage 6b that connect the compression side chamber L2 and the reservoir chamber R. As shown in FIG. Further, a suction valve 60 for opening and closing the suction passage 6a is laminated on the upper side of the valve case 6, and a damping valve 61 for opening and closing the discharge passage 6b is laminated on the lower side of the valve case 6.

The suction valve 60 opens when the shock absorber D expands to allow liquid to flow through the suction passage 6a from the reservoir chamber R toward the compression side chamber L2, but when the shock absorber D contracts, the suction passage 6a is kept closed. be. On the other hand, the damping valve 61 opens when the shock absorber D is contracted to provide resistance to the flow of the liquid from the compression side chamber L2 to the reservoir chamber R in the discharge passage 6b, but closes the discharge passage 6b when the shock absorber D is extended. maintained in condition.

According to the above configuration, when the piston rod 3 moves upward in the cylinder 1 and contracts the extension side chamber L1 when the shock absorber D is extended when the piston rod 3 withdraws from the cylinder 1, the liquid in the extension side chamber L1 flows into the extension side valve. 20 is pushed open, and it moves to the contraction side chamber L2 through the expansion side passage 2a. Further, when the shock absorber D is extended, the suction valve 60 is opened, and the liquid corresponding to 3 volumes of the piston rod withdrawn from the cylinder 1 is supplied from the reservoir chamber R to the compression side chamber L2 through the suction passage 6a.

At the time of extension of such a shock absorber D, resistance is given by the growth side valve|bulb 20 with respect to the flow of the liquid which goes to the pressure side chamber L2 from the growth side chamber L1. Therefore, when the shock absorber D is extended, the pressure in the extension side chamber L1 increases, and an extension side damping force that hinders the extension operation of the shock absorber D is generated.

Conversely, when the piston rod 3 enters the cylinder 1 and the shock absorber D is contracted, the piston 2 moves downward in the cylinder 1 and contracts the compression side chamber L2. , to the expansion side chamber L1 through the compression side passage 2b. Further, when the shock absorber D is contracted, the liquid in the compression side chamber L2 pushes open the damping valve 61, and the liquid corresponding to three volumes of the piston rod entering the cylinder 1 is discharged to the reservoir chamber R through the discharge passage 6b.

When the shock absorber D contracts like this, the damping valve 61 provides resistance to the flow of liquid from the pressure side chamber L2 to the reservoir chamber R. As shown in FIG. Therefore, when the shock absorber D contracts, the pressure in the cylinder 1 rises, and a compression-side damping force that prevents the shock absorber D from contracting is generated.

Thus, in the present embodiment, the extension side valve 20 functions as an extension side damping element for generating an extension side damping force, and the damping valve 61 functions as a compression side damping element for generating a compression side damping force. However, the configuration of each damping element is not limited to this. For example, the compression side valve 21 may be used as a compression side damping element. Alternatively, the piston 2 may be provided with an orifice that allows bi-directional flow, and the orifice may be used as a damping element for both expansion and compression.

Further, in the present embodiment, the shock absorber D is set as a single rod type, and the reservoir chamber R compensates for the volume of the piston rod 3 moving in and out of the cylinder 1 . Further, the shock absorber D has a cylinder 1 and an outer cylinder 10 and is set to a double cylinder type, and a reservoir chamber R is formed between the cylinder 1 and the outer cylinder 10 . However, the style of the shock absorber in which the present invention is embodied is not limited to this, and can be changed as appropriate.

For example, the outer cylinder 10 may be eliminated, and a reservoir tank having a reservoir chamber formed therein may be provided separately from the cylinder 1 . Alternatively, the outer cylinder 10 may be eliminated to form an expandable/contractible air chamber in the cylinder 1, and the volume of the piston rod 3 may be compensated by the air chamber. In the case where the shock absorber is of a monocylinder type as described above, the shock absorber may be of an inverted type by arranging the piston rod toward the wheel side and the cylinder toward the vehicle body side.

Furthermore, the piston rod 3 may be protruded from both sides of the piston 2 to the outside of the cylinder 1 to form a double-rod shock absorber. In such a case, the piston rod volume compensation itself can be made unnecessary.

In the shock absorber D of the present embodiment, an urging member is provided between the piston 2 and the rod guide 4 to apply a lateral force (a force acting in a direction perpendicular to the shaft) to the piston rod 3 in one direction. 7 is provided. The biasing member 7 is directly below the rod guide 4 and comprises an annular case portion 70 fitted to the inner periphery of the cylinder 1, a slider 71 slidingly contacting the outer periphery of the piston rod 3, and the case portion 70 and the slider 71. and a spring 72 interposed in a compressed state between.

Further, the case portion 70 of the present embodiment is made of rubber, synthetic resin, or the like, and has elasticity. Further, a stopper 8 facing the case portion 70 is provided on the outer circumference of the piston rod 3 and between the case portion 70 and the piston 2 . When the shock absorber D is fully extended, the stopper 8 abuts against the case portion 70, and the case portion 70 is elastically deformed to absorb the shock when the shock absorber D is fully extended. As described above, in the present embodiment, the case portion 70 of the biasing member 7 also functions as a cushion rubber that absorbs the shock when the shock absorber D is fully extended.

Moreover, the spring 72 of this embodiment is a coil spring. As shown in FIG. 2, the case portion 70 is formed with a recess 70a that opens toward the inner periphery, and one end of a spring 72 is accommodated in the recess 70a. On the other hand, the other end of the spring 72 is fitted to the outer periphery of the protrusion 71a provided on the slider 71. As shown in FIG.

In this embodiment, the slider 71 includes a guide portion 71b curved in an arc shape when viewed in the axial direction so as to follow the outer circumference of the piston rod 3, and the guide portion 71b is brought into sliding contact with the outer circumference of the piston rod 3. However, the guide portion 71b may be annular. Also, the spring 72 may be a spring other than a coil spring such as a disc spring.

2 shows a state in which the biasing member 7 is removed from the shock absorber D. As shown in FIG. In such a state, the spring 72 is completely stretched to its natural length. However, as shown in FIG. 1, when the biasing member 7 is attached to the shock absorber D, the spring 72 is compressed and elastically deformed, and the resulting elastic force biases the piston rod 3 away from the spring 72. be done.

In other words, the biasing member 7 applies a lateral force to the piston rod 3 in a direction away from the spring 72 (rightward in FIG. 2). By receiving such a lateral force from the biasing member 7, the piston rod 3 is always pressed in one direction toward the inner circumference of the rod guide 4 on the side opposite to the spring 72 when viewed from the piston rod 3. It slides in a closed state.

More specifically, for example, as shown in FIG. 8, when the lateral force acting on the rod guide 4 from the piston rod 3 side without the biasing member 7 tends to concentrate on the left front, the opposite is true. The biasing member 7 is mounted so that the spring 72 is positioned on the side (rear right). Then, as shown in FIG. 3, the lateral force acting on the rod guide 4 from the piston rod 3 side is prevented from straddling the zero lateral force.

According to this configuration, since the piston rod 3 always slides while being pressed against the inner circumference of the rod guide 4 in one direction, the occurrence of backlash vibration due to the clearance between the piston rod 3 and the rod guide 4 is prevented. . Therefore, the pressure on the contact surface between the piston rod 3 and the seal member 5 is stabilized, and the thickness of the liquid film formed by the seal member 5 on the outer circumference of the piston rod 3 is suppressed from becoming unstable.

When the spring 72 is arranged as described above, the biasing member 7 applies a lateral force to the piston rod 3 in the direction in which the lateral force input to the rod guide 4 gathers (left front) in the absence of the biasing member 7. will be given. In this case, since the lateral force required to suppress backlash vibration of the piston rod 3 is small, a small spring 72 with a small spring constant can be used. Therefore, the urging member 7 is made compact, and the mountability to the shock absorber D is improved.

Next, the effects of the shock absorber D according to this embodiment will be described.

A shock absorber D according to this embodiment includes a cylinder 1, a piston 2 slidably inserted into the cylinder 1, and a terminal (one end) connected to the piston 2 and protruding outside the cylinder 1. a piston rod 3 attached to the cylinder 1 to support the piston rod 3 in an axially slidable manner; and a seal member 5 attached to the rod guide 4 to seal the outer circumference of the piston rod 3. , and a biasing member 7 for applying a lateral force to the piston rod 3 in one direction.

According to the above configuration, the biasing member 7 presses the piston rod 3 in one direction on the inner periphery of the rod guide 4 to prevent rattling vibration due to the clearance (backlash) between the piston rod 3 and the rod guide 4 . As a result, the thickness of the liquid film formed by the sealing member 5 on the outer circumference of the piston rod 3 can be suppressed from becoming unstable.

Further, in the present embodiment, an annular case portion 70 in which the biasing member 7 is fitted to the inner periphery of the cylinder 1, a slider 71 in sliding contact with the outer periphery of the piston rod 3, and the case portion 70 and the slider 71 are provided. and a spring 72 interposed therebetween in a compressed state. According to this configuration, lateral force can be applied to the piston rod 3 using the elastic force of the spring 72 . Therefore, the configuration for applying a lateral force to the piston rod 3 in one direction by the biasing member 7 can be facilitated.

Furthermore, in the present embodiment, the case portion 70 has elasticity, and is compressed between the stopper 8 provided on the outer circumference of the piston rod 3 and the rod guide 4 when the shock absorber D is fully extended. Therefore, the impact when the shock absorber D is fully extended can be mitigated by the case portion 70 .

In other words, in the present embodiment, the case portion 70 also functions as a cushion rubber that absorbs the shock when the shock absorber D is fully extended. Therefore, according to the above configuration, even if the urging member 7 is provided, the length of the shock absorber D in the axial direction can be suppressed, and the mountability of the shock absorber D can be improved.

However, the configuration of the biasing member 7 is not limited to the above and can be changed as appropriate. For example, although the biasing member 7 shown in FIG. You can give it. Furthermore, in order to prevent the case portion 70 from rotating in the circumferential direction with respect to the cylinder 1, a rotation preventing structure such as unevenness may be provided, and the biasing member 7 may be changed as shown in FIG. 4-7. may

First, the biasing member 7A according to the first modification shown in FIG. It has a spring 72A interposed in a compressed state between 70A and slider 71A. Also in this configuration, the configuration for applying a lateral force to the piston rod 3 in one direction by the biasing member 7A can be facilitated.

Furthermore, in this example, a biasing member 7A is provided between the stopper 8 and the piston 2, and a cushion rubber 9 is provided between the stopper 8 and the rod guide 4. As shown in FIG. When the shock absorber is fully extended, the cushion rubber 9 is compressed between the stopper 8 and the rod guide 4 to absorb the shock when fully extended.

According to the above configuration, since the case portion 70A does not function as cushion rubber, the degree of freedom in selecting the material for the case portion 70A is improved. Also, the dead space between the piston 2 and the stopper 8 can be effectively used as a mounting space for the biasing member 7A. Furthermore, since the rod guide 4 and the biasing member 7A can be arranged apart from each other, even if the lateral force applied from the biasing member 7A to the piston rod 3 is small, the rattling vibration of the piston rod 3 can be prevented.

Therefore, according to the above configuration, even if the urging member 7A is provided, it is possible to suppress the length of the shock absorber from increasing in the axial direction, thereby improving the mountability of the shock absorber. Furthermore, according to the above configuration, a compact spring 72A having a small spring constant can be used, so that the urging member 7A can be miniaturized and mountability on the shock absorber can be improved.

Even when the case portion 70A is fitted to the outer circumference of the piston rod 3 as in this example, the case portion 70A can be made into an elastic body and used as a cushion rubber for absorbing the shock when the piston rod 3 is fully stretched. Of course it is good. Also in this example, the spring 72A may be a spring other than the coil spring. Furthermore, a plurality of springs 72A may be provided, and the resultant force of the elastic forces of these springs 72A may apply lateral force to the piston rod 3 in one direction. Further, in this example, in order to prevent the case portion 70A from rotating in the circumferential direction with respect to the piston rod 3, a rotation preventing structure such as unevenness may be provided.

Next, a biasing member 7B according to a second modified example shown in FIG. An annular slider 74 is fitted to the inner periphery of the rubber member 73 and is in sliding contact with the outer periphery of the piston rod 3 .

On the other hand, a biasing member 7C according to a third modification shown in FIG. It has an annular slider 76 which is fitted to the outer periphery of the rubber member 75 and is in sliding contact with the inner periphery of the cylinder 1 .

According to these second and third modifications, the elastic force of the rubber members 73 and 75 can be used to apply a lateral force to the piston rod 3 . Therefore, in each of the above configurations, the configuration for applying lateral force to the piston rod 3 in one direction by the urging members 7B and 7C can be facilitated.

The projecting directions of the protrusions 73a and 75a according to the second and third modifications may be radially inside or outside of the rubber members 73 and 75, respectively. In addition, if the center of the rubber member is the portion through which the central axis of the shock absorber passes in the urging member in the attached state, the state in which the annular rubber member is provided with a projection protruding inward (outward) has a natural length. The distance from the center of the rubber member to the inner (outer) circumference is uneven in the circumferential direction, and the distance is short (long), and the number of protrusions is multiple. There may be. In addition, in the second and third modifications, the rubber member 73 is prevented from rotating in the circumferential direction with respect to the cylinder 1 and the rubber member 75 is prevented from rotating in the circumferential direction with respect to the piston rod 3. Therefore, an anti-rotation structure such as unevenness may be provided.

Next, a biasing member 7D according to a fourth modified example shown in FIG. It is designed to give Also in this configuration, a lateral force is applied to the biasing member 7D in one direction. Furthermore, since the slider of the biasing member 7D can be omitted, the number of parts of the shock absorber can be reduced. Also, in this example, a spring or rubber may be used to apply a lateral force to the piston rod 3 in one direction.

Although preferred embodiments of the invention have been described in detail above, modifications, variations, and changes are possible without departing from the scope of the claims.

D... Shock absorber, 1... Cylinder, 2... Piston, 3... Piston rod, 4... Rod guide, 5... Seal member, 7, 7A, 7B, 7C, 7D. .. biasing member 8 .. stopper 40 .. cover portion 41 .. bush 70, 70A . ..Spring, 73, 75..Rubber member, 73a, 75a..Protrusion

Claims (7)

a cylinder;
a piston slidably inserted into the cylinder;
a piston rod connected to the piston and having one end protruding outside the cylinder;
a rod guide attached to the cylinder and axially slidably supporting the piston rod;
a seal member that is attached to the rod guide and seals the outer periphery of the piston rod;
A shock absorber installation structure for attaching a shock absorber to an object to be mounted, the shock absorber comprising a biasing member that applies a lateral force to the piston rod in one direction,
The shock absorber installation structure , wherein the biasing member applies a lateral force to the piston rod in a direction in which the lateral force input from the piston rod side to the rod guide gathers in the absence of the biasing member. . a cylinder;
a piston slidably inserted into the cylinder;
a piston rod connected to the piston and having one end protruding outside the cylinder;
a rod guide attached to the cylinder and axially slidably supporting the piston rod;
a seal member that is attached to the rod guide and seals the outer periphery of the piston rod;
a biasing member that applies a lateral force to the piston rod in one direction;
The biasing member includes an annular case portion fitted to the inner circumference of the cylinder, a slider slidably contacting the outer circumference of the piston rod, and a compressed state interposed between the case portion and the slider. A shock absorber, comprising: a cylinder;
a piston slidably inserted into the cylinder;
a piston rod connected to the piston and having one end protruding outside the cylinder;
a rod guide attached to the cylinder and axially slidably supporting the piston rod;
a seal member that is attached to the rod guide and seals the outer periphery of the piston rod;
a biasing member that applies a lateral force to the piston rod in one direction;
The biasing member includes an annular case portion fitted to the outer periphery of the piston rod, a slider slidably contacting the inner periphery of the cylinder, and interposed in a compressed state between the case portion and the slider. A shock absorber, comprising: The shock absorber according to claim 2 or 3, wherein the case part has elasticity, and is compressed between a stopper provided on the outer periphery of the piston rod and the rod guide when fully extended. a cylinder;
a piston slidably inserted into the cylinder;
a piston rod connected to the piston and having one end protruding outside the cylinder;
a rod guide attached to the cylinder and axially slidably supporting the piston rod;
a seal member that is attached to the rod guide and seals the outer periphery of the piston rod;
a biasing member that applies a lateral force to the piston rod in one direction;
The urging member includes a ring-shaped rubber member fitted to the inner periphery of the cylinder and including a projection projecting radially inward or outward, and a rubber member fitted to the inner periphery of the rubber member to move the piston rod. A shock absorber characterized by having an annular slider that slides on an outer circumference. a cylinder;
a piston slidably inserted into the cylinder;
a piston rod connected to the piston and having one end protruding outside the cylinder;
a rod guide attached to the cylinder and axially slidably supporting the piston rod;
a seal member that is attached to the rod guide and seals the outer periphery of the piston rod;
a biasing member that applies a lateral force to the piston rod in one direction;
The urging member includes a ring-shaped rubber member fitted to the outer periphery of the piston rod and including a projection radially inwardly or outwardly protruding; A shock absorber characterized by having an annular slider in sliding contact with the . a cylinder;
a piston slidably inserted into the cylinder;
a piston rod connected to the piston and having one end protruding outside the cylinder;
a rod guide attached to the cylinder and axially slidably supporting the piston rod;
a seal member that is attached to the rod guide and seals the outer periphery of the piston rod;
a biasing member that applies a lateral force to the piston rod in one direction;
The rod guide has an annular lid portion fitted to the cylinder, and an annular bushing in sliding contact with the outer periphery of the piston rod,
A shock absorber, wherein the biasing member is provided between the lid portion and the bush, and applies a lateral force to the piston rod via the bush.

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