CN113631831A

CN113631831A - Buffer device

Info

Publication number: CN113631831A
Application number: CN202080024386.3A
Authority: CN
Inventors: 柴原和晶; 高桥一树
Original assignee: Hitachi Astemo Ltd
Current assignee: Hitachi Astemo Ltd
Priority date: 2019-08-02
Filing date: 2020-06-26
Publication date: 2021-11-09
Also published as: WO2021024642A1; JPWO2021024642A1; JP7045785B2

Abstract

The support member is provided so as to be capable of coming into contact with and separating from the valve seat member by rotation, and the rod guide is provided with a through hole for communicating the inside and outside of the inner cylinder and an adjustment rod rotatably inserted into the through hole. An engagement pin and an engagement hole are provided between the adjustment lever and the support member, and are engaged at an adjustment position where the piston is close to the lever guide and disengaged at a remote position. The support member is provided so as to be capable of coming into contact with and separating from the valve seat member by rotation, and a communication hole for communicating the inside of the inner cylinder with the outside and an adjustment rod rotatably inserted into the through hole are provided in the bottom valve or the like. An engagement pin and an engagement hole are provided between the adjustment lever and the support member, and are engaged at an adjustment position where the piston is close to the bottom valve and disengaged at a remote position.

Description

Buffer device

Technical Field

The present invention relates to a shock absorber for suppressing shaking of a structure such as a building or a railway vehicle.

Background

In general, a shock absorber using a working fluid is provided in a structure such as a building or a railway vehicle to absorb vibration. This shock absorber is of a type that applies a resistance force to the working fluid sealed in the cylinder tube by the valve mechanism to generate a damping force to damp vibration.

The buffer is provided with: a cylinder barrel; a piston which is provided in the cylinder tube, divides the cylinder tube into two chambers, and slides on the inner peripheral surface of the cylinder tube; a piston rod connected to the piston and extending in an axial direction of the cylinder; and a blocking member for blocking both ends of the cylinder tube. Since this type of damper is called a double flow type, the piston is provided with a valve mechanism having: a flow path that communicates between the two chambers; a valve seat member provided in the flow path; a valve body seated on the valve seat member; a biasing member that biases the valve body toward the valve seat member; and a support member that supports an end portion of the biasing member opposite to the valve body (patent document 1).

Documents of the prior art

Patent document

Patent document 1: japanese unexamined patent publication No. 2006-194372

Disclosure of Invention

Technical problem to be solved by the invention

Further, in the damper of patent document 1, a valve mechanism for generating a damping force is provided in the piston. Therefore, when the damping force of the valve mechanism is adjusted after manufacture, for example, when the valve mechanism fails a performance test for measuring the damping force, the cylinder must be disassembled and the piston removed, which causes a problem that the adjustment work of the damping force requires much effort and time.

The present invention has been made in view of the above-described conventional problems, and an object of the present invention is to provide a shock absorber capable of adjusting a damping force without performing a disassembly operation.

Technical solution for solving technical problem

One embodiment of the present invention is a buffer including:

a cylinder barrel;

a piston which is provided in the cylinder tube, divides the cylinder tube into two chambers, and slides on an inner peripheral surface of the cylinder tube;

a piston rod connected to the piston and extending in an axial direction of the cylinder; a plugging member that plugs both ends of the cylinder tube;

a flow path formed in the piston and communicating the two chambers;

a valve seat member provided in the flow path;

a valve body seated on the valve seat member;

a biasing member that biases the valve body toward the valve seat member;

a support member that supports an end portion of the biasing member opposite to the valve body;

at least one member of the valve seat member and the support member is provided so as to be able to be brought into contact with and separated from the other member by rotation, the closing member is provided with a through hole for communicating the inside and outside of the cylinder and an adjustment rod inserted rotatably through the through hole, and an engagement member is provided between the adjustment rod and the one member, and is engaged in the rotation direction at an adjustment position where the piston approaches the closing member, and is disengaged at a position away from the adjustment position.

Further, an embodiment of the present invention is a buffer including:

a cylinder barrel;

a piston rod connected to the piston and extending in an axial direction of the cylinder;

a closing member that closes both ends of the cylinder tube;

a plurality of flow paths formed in the piston and communicating the two chambers with each other;

a valve seat member provided in one of the plurality of flow paths;

a valve body seated on the valve seat member;

a biasing member that biases the valve body toward the valve seat member;

the support member is provided to be screwed to the piston rod or the piston, and is movable in the axial direction of the cylinder by rotation to adjust the length of the biasing member in the axial direction of the cylinder, and the blocking member includes an engagement pin that is engaged with the support member at an adjustment position where the piston approaches the blocking member and extends in the axial direction of the cylinder.

According to one embodiment of the present invention, the damping force can be adjusted without performing the disassembling operation.

Drawings

Fig. 1 is a vertical sectional view showing a hydraulic shock absorber according to a first embodiment of the present invention.

Fig. 2 is a longitudinal sectional view showing a method of the rod guide, the piston, the valve mechanism, the adjustment rod, and the like in fig. 1.

Fig. 3 is a longitudinal sectional view of the valve mechanism in an adjustment position state in which the piston is brought close to the rod guide as viewed from the same position as in fig. 2.

Fig. 4 is a vertical cross-sectional view showing a hydraulic shock absorber according to a second embodiment of the present invention.

Fig. 5 is a vertical cross-sectional view of a hydraulic shock absorber according to a third embodiment of the present invention, as viewed from the same position as in fig. 2.

Fig. 6 is a longitudinal sectional view of the piston approaching the rod guide from the same position as in fig. 5, with the contraction-side valve mechanism disposed in the adjustment position state.

Fig. 7 is an exploded perspective view of the outer thread cylinder and the inner thread body.

Fig. 8 is a vertical cross-sectional view showing a hydraulic shock absorber according to a fourth embodiment of the present invention.

Fig. 9 is a vertical cross-sectional view showing a state where the piston is brought close to the rod guide and the engagement pin is engaged with the support member.

Fig. 10 is a vertical cross-sectional view illustrating a hydraulic shock absorber according to a fifth embodiment of the present invention.

Fig. 11 is a characteristic diagram showing a relationship between a displacement velocity of the piston and the damping force.

Fig. 12 is an enlarged vertical cross-sectional view of an essential part showing a state in which a cover is attached to a rod guide according to a sixth embodiment of the present invention.

Fig. 13 is an enlarged longitudinal sectional view of a valve mechanism according to a seventh embodiment of the present invention.

Fig. 14 is a vertical cross-sectional view showing a rod guide according to an eighth embodiment of the present invention together with an adjustment rod and the like.

Fig. 15 is an enlarged longitudinal sectional view of a valve mechanism according to a ninth embodiment of the present invention.

Detailed Description

Hereinafter, a case where the shock absorber according to the embodiment of the present invention is applied to a hydraulic shock absorber used in a building or the like as a seismic isolation damper or a shock absorbing damper will be described in detail with reference to the drawings.

Fig. 1 to 3 show a first embodiment of the present invention. In the first embodiment, the case where the support member is provided as one member so as to be able to be brought into contact with and separated from the valve seat member as the other member by rotation is exemplified.

In fig. 1, a hydraulic shock absorber 1 according to a first embodiment is, for example, a hydraulic shock absorber that is attached to a wall surface of a building in a horizontally placed state. The hydraulic shock absorber 1 includes an inner cylinder 6, a bottom valve 7, a piston 8, a piston rod 9, a rod guide 11, a reduction-side valve mechanism 12, and an extension-side valve mechanism 20, which will be described later.

Here, in the first embodiment, since the hydraulic shock absorber 1 is disposed in a horizontally placed state, the projecting side of the piston rod 9 is described as the left side and the bottom cover 3 side is described as the right side in fig. 1. The arrangement of the hydraulic shock absorber 1 is an example of a plurality of arrangements, and thus the arrangement is not limited to the horizontal arrangement shown in fig. 1, and the arrangement may be vertical or inclined.

The outer tube 2 of the hydraulic shock absorber 1 is positioned on the outer peripheral side of the inner tube 6 and is provided coaxially with the inner tube 6. The right end of the outer cylinder 2 is closed by a bottom cover 3, and the left end is closed by a lever guide 11 described later. Here, the bottom cover 3 is provided with a mounting hole 4, and the piston rod 9 is provided with a mounting hole 5. These mounting holes 4 and 5 are mounted on a structure provided on a wall surface of a building, for example.

The inner cylinder 6 constituting the cylinder is arranged to form concentric circles inside the outer cylinder 2. The right end of the inner tube 6 is fitted into the bottom valve 7, and is fixed to the bottom cover 3 via the bottom valve 7. The left end side of the inner cylinder 6 is fitted and attached to the rod guide 11. The inner side of the inner tube 6 is an inner circumferential surface 6A, and the piston 8 slides on the inner circumferential surface 6A. Further, working oil as a working fluid is sealed in the inner tube 6. The working fluid is not limited to the working oil, and for example, water mixed with an additive may be used.

An annular liquid reservoir a is formed between the inner cylinder 6 and the outer cylinder 2, and a gas is sealed in the liquid reservoir a together with the working oil. The gas may be air in an atmospheric pressure state, or a compressed gas such as nitrogen may be used. The gas in the reservoir chamber a is compressed by compensating for the volume of the piston rod 9 when the piston rod 9 is contracted (compression stroke).

The bottom valve 7 is provided between the bottom cover 3 and the inner tube 6 at the right end side of the inner tube 6. The bottom valve 7 is a portion for closing the right end of the inner cylinder 6, and constitutes a closing member together with the bottom cover 3. The bottom valve 7 has a thick-walled disk-shaped base portion 7A. The base portion 7A is provided with a suction valve 7B serving as a check valve for allowing the working oil in the reservoir chamber a to flow into the bottom side oil chamber C in the inner tube 6 and preventing the working oil from flowing in the reverse direction. The base portion 7A is provided with a relief valve 7C that opens when the pressure in the bottom side oil chamber C is equal to or higher than a set pressure, and allows the hydraulic oil in the bottom side oil chamber C to escape to the reservoir chamber a.

Here, the suction valve 7B is opened and closed so that the inside of the inner cylinder 6 is always kept filled with the hydraulic oil when the piston 8 is slidingly displaced to the rod extension side (left side) in the inner cylinder 6. That is, during the extension stroke of the piston rod 9, when the piston 8 is slidingly displaced in the direction of the rod-side oil chamber B in the inner cylinder 6, the suction valve 7B is opened, and the hydraulic oil in the reservoir chamber a is sucked into the bottom-side oil chamber C.

The relief valve 7C is opened and closed to allow the hydraulic oil in the inner tube 6 to escape when the piston 8 slides and displaces rightward in the inner tube 6. That is, when the piston 8 is slidingly displaced in the direction of the bottom side oil chamber C in the inner cylinder 6 during the contraction stroke of the piston rod 9, the relief valve 7C is opened and the hydraulic oil in the bottom side oil chamber C is discharged to the reservoir a.

The piston 8 is inserted (fitted) into the inner cylinder 6 so as to be slidable in the axial direction. The piston 8 divides the interior of the inner cylinder 6 into two chambers, a rod-side oil chamber B and a bottom-side oil chamber C. The piston 8 is formed as a thick cylindrical body, and the mounting shaft portion 9A of the piston rod 9 is inserted into the mounting hole 8A at the center position. A contraction side valve mechanism 12 and an extension side valve mechanism 20, which will be described later, are provided at intermediate positions in the radial direction of the piston 8. In addition, the piston 8 has a rod-side end surface 8B opposite to the rod guide 11 and a bottom-side end surface 8C opposite to the foot valve 7.

The piston rod 9 is formed as an elongated cylindrical body, and the proximal end side that enters the inner cylinder 6 is connected to the piston 8. Specifically, the base end side of the piston rod 9 is a small-diameter mounting shaft portion 9A, and the mounting shaft portion 9A is inserted into the mounting hole 8A of the piston 8 to fasten the nut 10, thereby being integrally connected to the piston 8. On the other hand, the front end side (protruding end side) of the piston rod 9 extends to the outside of the inner tube 6 via a rod guide 11 or the like. The distal end side of the piston rod 9 is attached to the structure on the wall surface via the attachment hole 5.

The rod guide 11 is disposed on the left end side of the outer cylinder 2 and the inner cylinder 6. The rod guide 11 is formed as a thick annular plate body because it constitutes a closing member. The rod guide 11 has an insertion hole 11A formed at a central position thereof in the axial direction. The rod guide 11 positions the left end side of the inner cylinder 6 at the center of the outer cylinder 2, and guides (guides) the piston rod 9 to be slidable in the axial direction through the insertion hole 11A. The rod guide 11 has an inner end surface 11B facing the piston 8 and an outer end surface 11C located outside. Further, a reduction-side adjustment lever 19 is provided at an intermediate position of the lever guide 11, more precisely, at the same radial position as the reduction-side valve mechanism 12.

Here, the piston 8 is provided with: a reduction-side valve mechanism 12 that acts when the piston rod 9 is reduced; and an extension-side valve mechanism 20 that acts when the piston rod 9 is extended. The reduction-side valve mechanism 12 and the extension-side valve mechanism 20 have substantially the same configuration, except that the mounting orientation with respect to the piston 8 is axially reversed.

The reduction-side valve mechanism 12 is provided to the piston 8. The contraction-side valve mechanism 12 provides a flow resistance to the working oil flowing from the bottom-side oil chamber C to the rod-side oil chamber B when the piston rod 9 contracts and the piston 8 moves to the right (the bottom valve 7 side). The reduction-side valve mechanism 12 is provided in plurality at predetermined intervals in the circumferential direction of the piston 8. The reduction-side valve mechanism 12 includes a reduction-side flow passage 13, a valve seat member 14, a valve body 15, an urging member 16, and a support member 17, which will be described later.

The reduction-side flow passage 13, which is a flow passage, allows the working oil to flow from the bottom-side oil chamber C to the rod-side oil chamber B when the piston rod 9 is reduced. As shown in fig. 2, the reduced-size flow passage 13 is formed by a large-diameter portion 13A having a large diameter and a bottomed hole and opening to the rod-side end surface 8B, and a small-diameter portion 13B having a small-diameter through hole and opening from the bottom center of the large-diameter portion 13A to the bottom-side end surface 8C. The large diameter portion 13A is formed with a female screw portion 13C, for example, in a range from an intermediate portion to an opening end in the axial direction. The female screw portion 13C is screwed to a male screw portion 17A of a support member 17 described later.

The valve seat member 14 is provided in the reduction-side flow passage 13. The seat member 14 is formed by a step portion between the large diameter portion 13A and the small diameter portion 13B of the reduction-side flow passage 13. The valve body 15 is separated and positioned from the valve seat member 14 so as to open and close the small diameter portion 13B.

The valve element 15 is disposed in the large diameter portion 13A of the reduced-size flow path 13 and is provided at a position where the small diameter portion 13B is closed. The valve body 15 is formed as a poppet valve and is normally seated on the valve seat member 14 by an urging member 16.

The biasing member 16 is disposed in the large diameter portion 13A of the reduction-side flow passage 13 together with the valve element 15. The urging member 16 is formed as a compression coil spring. The biasing member 16 biases the valve body 15 toward the valve seat member 14. Here, the biasing member 16 is fixed to the large diameter portion 13A in a state of being compressed from a free length state to an axial direction, and a damping force (flow resistance of the hydraulic oil) which is a valve opening pressure of the valve body 15 is changed by a set load at this time. Further, since the set load of the biasing member 16 changes in accordance with the length of the biasing member 16 in the axial direction of the inner tube 6, the characteristics of the damping force can be changed by adjusting the length of the biasing member 16 by the support member 17 described later.

The support member 17, which is one member, supports an end portion of the biasing member 16 opposite to the valve body 15, and is therefore provided in the large diameter portion 13A of the reduced-size flow passage 13. The support member 17 is formed of a thick cylindrical body, and has an external thread portion 17A on the outer peripheral side thereof, which is screwed into the internal thread portion 13C of the reduction-side flow passage 13. On the other hand, a communication passage 17B penetrating in the axial direction is provided at the center of the support member 17. In addition, a plurality of, for example, two engagement holes 17D of the end surface 17C on the side of the lever guide 11 are provided in the support member 17. Each engagement hole 17D is formed as a bottomed circular hole, and is engaged by being inserted into an engagement pin 19D of an adjustment lever 19 described later. That is, each engaging hole 17D constitutes an engaging member together with the engaging pin 19D.

In the support member 17, the valve body 15 and the biasing member 16 can be disposed in the large diameter portion 13A by screwing the external thread portion 17A on the outer peripheral side to the internal thread portion 13C in a state where the valve body 15 and the biasing member 16 are disposed in the large diameter portion 13A. On the other hand, the support member 17 can be brought into contact with and separated from the valve seat member 14 as the other member by rotating the adjustment lever 19. That is, the support member 17 can change the damping force by adjusting the length of the biasing member 16.

The through hole 18 is located in the rod guide 11 to communicate the inside and outside of the inner cylinder 6. The diameter dimension of the through hole 18 from the center line (axis) of the piston rod 9 to the center line of the through hole 18 is set to be the same as the diameter dimension from the center line (axis) of the piston rod 9 to the center line of the reduction-side flow passage 13 (support member 17). That is, the through hole 18 is disposed so that an arc drawn by the center line of the narrowed side flow passage 13 with the center line of the rod 9 as the center coincides with an arc drawn by the center line of the through hole 18 with the center line of the rod 9 as the center.

The through hole 18 extends parallel to the center line of the piston rod 9 and penetrates the rod guide 11. The through-holes 18 are formed as stepped circular holes. The through hole 18 is expanded in diameter at the opening of the through hole 18 on the piston 8 side to form a stepped portion 18A. The step portion 18A can accommodate a large diameter portion 19B of an adjustment lever 19 described later. In addition, the step portion 18A abuts against the large diameter portion 19B of the adjustment rod 19 protruding outward from the through hole 18 of the rod guide 11, and the pressure in the inner tube 6 prevents the adjustment rod 19 from falling out. Further, an O-ring 18B for sealing between the small diameter portions 19A of the adjustment rod 19 is provided in the through hole 18.

The adjustment rod 19 is a member that adjusts the damping force of the reduction-side valve mechanism 12, and is provided on the rod guide 11 that constitutes the closing member. The adjustment rod 19 is formed as a stepped cylindrical body and is rotatably inserted through the through hole 18. The adjustment rod 19 is composed of a cylindrical small-diameter portion 19A, a large-diameter portion 19B having a diameter increased at a distal end portion on the piston 8 side, which is one end of the small-diameter portion 19A, a tool attachment portion 19C, for example, having a prism shape, provided at the other end of the small-diameter portion 19A outside the rod guide 11, and a cylindrical engagement pin 19D provided on the large-diameter portion 19B. The large diameter portion 19B is formed as a cylindrical body accommodated in the stepped portion 18A of the through hole 18.

The engagement pins 19D of the adjustment lever 19 are inserted into the two engagement holes 17D provided in the support member 17 of the reduction-side valve mechanism 12. Therefore, the engaging pins 19D are configured to correspond to the number, the interval size, and the inner diameter size of the engaging holes 17D, that is, two engaging pins are provided so as to be inserted into the engaging holes 17D and engaged with each other in the rotational direction.

Next, an example of a procedure for adjusting the damping force generated by the reduction-side valve mechanism 12 configured as described above will be described. In this case, the piston rod 9 is extended greatly, and the piston 8 is brought close to the rod guide 11. As shown in fig. 3, the position of the piston 8 close to the rod guide 11 is an adjustment position. After the piston 8 and the like are disposed at the adjustment position, the piston 8 (piston rod 9) and the inner cylinder 6 (outer cylinder 2) are relatively rotated, and the support member 17 and the adjustment rod 19 are disposed coaxially.

After the support member 17 and the adjustment rod 19 are aligned, the engagement pins 19D are inserted into the engagement holes 17D of the support member 17 while moving the adjustment rod 19 toward the piston 8. In this state, a tool such as a wrench is engaged with the tool connecting portion 19C of the adjustment lever 19, and the support member 17 is rotated in any direction via the adjustment lever 19. Thus, the support member 17 moves in the axial direction (left and right directions) along the crest, and thus the set load can be adjusted together with the attachment length of the biasing member 16.

Next, since the extension-side valve mechanism 20 functions when the piston rod 9 extends, a plurality of the extension-side valve mechanisms are provided at predetermined intervals in the circumferential direction of the piston 8. The extension-side valve mechanism 20 includes an extension-side flow path 21, a valve seat member 22, a valve body 23, an urging member 24, and a support member 25, as in the case of the reduction-side valve mechanism 12. However, the expansion-side valve mechanism 20 is different from the reduction-side valve mechanism 12 in that the mounting orientation thereof with respect to the piston 8 is axially opposite. Specifically, each engagement hole 25D of the support member 25 is disposed on the base valve 7 side and is fitted to an engagement pin 27D of the adjustment lever 27.

The through hole 26 is provided in the base portion 7A of the bottom valve 7 as a closing member and the bottom cap 3. The adjustment rod 27 on the extension side is provided in the through hole 26, and is constituted by a small diameter portion 27A, a large diameter portion 27B, a tool connecting portion 27C, and each engagement pin 27D. The step of adjusting the damping force of the expansion-side valve mechanism 20 is the same as the step of adjusting the damping force of the reduction-side valve mechanism 12, and therefore, the description thereof is omitted.

Since the hydraulic shock absorber 1 according to the first embodiment is a hydraulic shock absorber having the above-described structure, the operation thereof will be described below.

The hydraulic shock absorber 1 is attached to a structure such as a wall surface of a building through the attachment hole 4 on the bottom cover 3 side and the attachment hole 5 on the piston rod 9 side. Thus, the piston rod 9 contracts and expands, so that the vibration of the building can be attenuated, and the sway can be suppressed.

During the contraction stroke of the piston rod 9, the piston 8 is slidingly displaced toward the side of the foot valve 7. Thus, since the bottom side oil chamber C is in a high-pressure state, the reduction-side valve mechanism 12 provided in the piston 8 opens the valve body 15 against the biasing member 16, and the hydraulic oil in the bottom side oil chamber C flows into the rod side oil chamber B through the reduction-side flow passage 13. At this time, the biasing force of the biasing member 16 imparts resistance to the hydraulic oil flowing through the reduction-side flow passage 13, thereby generating damping force against the reduction operation of the piston rod 9 and suppressing vibration.

In the contraction stroke of the piston rod 9, the relief valve 7C of the bottom valve 7 is opened by the pressure in the bottom side oil chamber C, and only the working oil in the bottom side oil chamber C corresponding to the volume of the piston rod 9 is discharged to the reservoir chamber a. At this time, since the relief valve 7C is biased in the valve closing direction, the damping force can be generated by the biasing force.

On the other hand, during the extension stroke of the piston rod 9, the piston 8 is slidingly displaced toward the rod guide 11 side. Accordingly, since the inside of the rod-side oil chamber B is in a high-pressure state, the extension-side valve mechanism 20 provided in the piston 8 opens, and the hydraulic oil in the rod-side oil chamber B flows into the bottom-side oil chamber C through the extension-side flow passage 21. At this time, the biasing force of the biasing member 24 gives resistance to the hydraulic oil, thereby generating damping force against the extension operation of the piston rod 9 and suppressing vibration.

Next, an example of the operation of adjusting the damping force generated by the reduced-side valve mechanism 12 will be described. The hydraulic shock absorber 1 is removed from the wall surface, or the mounting hole 5 of the piston rod 9 is removed from the structure on the wall surface. In this state, the piston rod 9 is extended to place the piston 8 at an adjustment position (position shown in fig. 3) close to the rod guide 11. After the piston 8 is disposed at the adjustment position, the inner cylinder 6 (outer cylinder 2) and the piston 8 (piston rod 9) are relatively rotated to align the reduction-side valve mechanism 12 with the reduction-side adjustment rod 19. While the adjustment lever 19 is moved and rotated toward the support member 17, the engagement pin 19D is fitted into the engagement hole 17D of the support member 17.

After the adjustment lever 19 and the support member 17 are engaged in the rotation direction, a tool such as a wrench is connected to the tool connecting portion 19C of the adjustment lever 19 to rotate the adjustment lever 19. The support member 17 and the valve seat member 14 can be moved closer to or away from each other in accordance with the rotational direction at this time, and the set load of the biasing member 16, that is, the valve opening pressure of the valve body 15 can be adjusted.

When the reduction-side valve mechanism 12 to be adjusted is switched to another reduction-side valve mechanism 12, the inner cylinder 6 (outer cylinder 2) and the piston 8 (piston rod 9) are relatively rotated, and the other reduction-side valve mechanism 12 and the adjustment rod 19 are aligned to perform the above-described operation. On the other hand, the operation of adjusting the damping force generated by the expansion-side valve mechanism 20 is almost the same as the operation of adjusting the reduction-side valve mechanism 12, except that the movement direction of the piston 8 is different, and therefore, the description thereof is omitted.

Here, a performance test is performed on the hydraulic shock absorber 1 as to whether or not the damping force values of the

valve mechanisms

12 and 20 are within a predetermined range after manufacture. In the event that the performance test fails, the damping force of each

valve mechanism

12, 20 must be adjusted. After the shipment to the customer, regular inspections are also performed, and readjustment may be necessary according to the inspection results. In the conventional hydraulic shock absorber, the cylinder and the piston must be removed in order to adjust the damping force of each valve mechanism, and therefore, the adjustment work requires much effort and time.

However, according to the present embodiment, in the reduction-side valve mechanism 12, the support member 17 is provided so as to be able to contact and separate from the valve seat member 14 by rotating. The rod guide 11 as a blocking member is provided with a through hole 18 for communicating the inside and outside of the inner cylinder 6, and an adjustment rod 19 inserted rotatably through the through hole 18. In addition, between the adjustment rod 19 and the support member 17, the piston 8 includes an engagement pin 19D and an engagement hole 17D that constitute an engagement member that engages in the rotational direction at an adjustment position close to the rod guide 11 and disengages at a position away from the adjustment position. Similarly, in the extension-side valve mechanism 20, the support member 25 is provided so as to be able to contact and separate from the seat member 22 by rotating. The bottom valve 7 and the bottom cover 3 as the closing members are provided with a through hole 26 for communicating the inside and outside of the inner tube 6 and an adjustment rod 27 inserted rotatably into the through hole 26. In addition, between the adjustment lever 27 and the support member 25, the piston 8 has an engagement pin 27D and an engagement hole 25D that constitute an engagement member that engages in the rotational direction at an adjustment position close to the foot valve 7 and disengages at a position away from the adjustment position.

Therefore, by moving the piston 8 to the adjustment position, the support member 17 is rotated by the adjustment rod 19, or the support member 25 is rotated by the adjustment rod 27, whereby the damping forces on the contraction side and the expansion side can be adjusted. Thus, even when the damping forces of the

valve mechanisms

12 and 20 are readjusted after the hydraulic shock absorber 1 is manufactured, the disassembling work of the outer cylinder 2, the inner cylinder 6, the rod guide 11, and the like can be omitted. As a result, the operation of adjusting the damping force generated by the hydraulic shock absorber 1 can be easily performed. Further, since the disassembling work is not necessary, it is possible to prevent the contamination of foreign matter, the damage of the seal portion due to the disassembling work, and the like, and to improve the reliability and the durability.

A stepped portion 18A is formed by expanding the diameter of the through hole 18 at the opening portion of the through hole 18 on the piston 8 side. On the other hand, the adjustment rod 19 has a large diameter portion 19B formed by expanding the diameter of the piston 8-side tip portion. When the adjustment lever 19 is not in use, the large diameter portion 19B is housed in the step portion 18A. Thus, the step portion 18A can receive the load acting on the adjustment lever 19, and can prevent the adjustment lever 19 from falling off from the through hole 18.

Next, fig. 4 shows a second embodiment of the present invention. The present embodiment is characterized in that the flow path on the reduction side, the valve seat member, the valve body, the biasing member, the through hole, and the adjustment rod are provided in the closing member. In the second embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof will be omitted.

In fig. 4, a hydraulic shock absorber 31 of the second embodiment includes a thick bottom cover 32 and a bottom valve 33 which constitute a sealing member. The bottom valve 33 is composed of a base portion 33A and an intake valve 33B, and a reduction-side valve mechanism 34 described later is provided in the base portion 33A. The reduction-side valve mechanism 34 also serves as a relief valve for allowing the hydraulic oil in the bottom-side oil chamber C to escape to the reservoir a. The reduction-side valve mechanism 34 includes a reduction-side flow passage 35, a valve seat member 36, a valve body 37, an urging member 38, and a support member 39, which will be described later.

A reduction-side flow passage 35 as a flow passage is provided in the base portion 33A of the bottom valve 33, and communicates the bottom-side oil chamber C and the reservoir chamber a. The reduced-size side flow passage 35 is formed by a large-diameter portion 35A formed by a large-diameter bottomed hole opening on the bottom cover 32 side, a small-diameter portion 35B formed by a small-diameter through hole from the bottom center of the large-diameter portion 35A to the bottom side oil chamber C side, and a passage portion 35C communicating the large-diameter portion 35A and the reservoir chamber a. A female screw portion is formed on the inner peripheral side of the large diameter portion 35A.

The seat member 36 as the other member is formed by a step portion between the large diameter portion 35A and the small diameter portion 35B of the reduction-side flow passage 35. The valve body 37 is located in the large diameter portion 35A of the reduced-size flow passage 35 and is seated on the valve seat member 36. The biasing member 38 is disposed in the large diameter portion 35A together with the valve body 37, and biases the valve body 37 toward the valve seat member 14.

The support member 39, which is one member, is screwed into the large diameter portion 35A because it supports the end portion of the biasing member 38 opposite to the valve body 37. In the support member 39, a plurality of, for example, two engagement holes 39D are provided at the end surface on the bottom cover 32 side. Engagement pins 41D of an adjustment lever 41 described later are inserted into the engagement holes 39D. That is, each engaging hole 39D constitutes an engaging member together with the engaging pin 41D. The support member 39 can be brought into contact with and separated from the valve seat member 36 by rotating the adjustment lever 41.

The through hole 40 is provided to axially penetrate the bottom cover 32 so as to be coaxial with the large diameter portion 35A of the reduced-size flow passage 35. The adjustment lever 41 is provided to the bottom cover 32 constituting the closing member. The adjustment lever 41 has two engagement pins 41D on a front end surface facing the support member 39. Each engagement pin 41D is inserted into each engagement hole 39D of the support member 39 and engaged in the rotational direction.

Therefore, also in the second embodiment configured as described above, almost the same operational effects as those in the first embodiment can be obtained. In particular, according to the second embodiment, both the damping force on the contraction side and the damping force on the expansion side of the piston rod 9 can be adjusted from the bottom cover 32 side, and workability can be improved.

Next, fig. 5 to 7 show a third embodiment of the present invention. The present embodiment is characterized in that one member is constituted by a cylindrical outer cylinder having an outer thread portion on an outer circumferential side thereof to be screwed to an inner circumferential surface of the flow passage, and an inner screw having an inner thread portion on an inner circumferential side thereof to be screwed to the inner thread portion of the outer cylinder, and the outer cylinder is provided with one or more notches for allowing the outer cylinder to be elastically deformed in a radial direction, and at least one of the inner thread portion of the outer cylinder and the outer thread portion of the inner screw may be formed as a tapered thread for enlarging a diameter dimension of the outer cylinder by widening the notch when the inner screw is screwed to the outer cylinder. In the third embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof will be omitted.

In fig. 5, the reduction-side valve mechanism 51 of the third embodiment is provided in the piston 8. The reduction-side valve mechanism 51 includes a reduction-side flow passage 52, a valve seat member 53, a valve body 54, an urging member 55, and a support member 56, which will be described later.

The reduction-side flow passage 52 as a flow passage is provided in the piston 8, and is composed of a large-diameter portion 52A and a small-diameter portion 52B, and a female screw portion 52C is formed in the large-diameter portion 52A, as in the reduction-side flow passage 13 of the first embodiment.

The valve seat member 53, which is the other member, is formed by a stepped portion between the large diameter portion 52A and the small diameter portion 52B of the reduced-side flow passage 52. The valve body 54 is disposed in the large diameter portion 52A of the reduced-size flow passage 52 and is provided at a position where the small diameter portion 52B is closed. The valve body 54 is normally seated on the valve seat member 53 by the urging member 55. The biasing member 55 is disposed in the large diameter portion 52A of the reduced-size flow passage 52 together with the valve body 54. The biasing member 55 is composed of a compression coil spring, and biases the valve body 54 toward the valve seat member 53.

The support member 56, which is one member, is provided in the large diameter portion 52A of the reduced-size side flow passage 52, since it supports the end portion of the biasing member 55 on the opposite side from the valve body 54. The support member 56 is constituted by an outer screw cylinder 57 and an inner screw body 58.

As shown in fig. 7, the outer threaded cylinder 57 is formed as a bottomed cylindrical body that closes the valve body 54 side. The outer threaded cylinder 57 has an outer threaded portion 57A on the outer peripheral side and an inner threaded portion 57B on the inner peripheral side. The female screw portion 57B is formed as a tapered thread whose inner diameter dimension increases toward the rod guide 11 side.

Further, a communication passage 57C is formed at the center of the bottom of the outer threaded cylinder 57. In a cylinder portion 57D other than the bottom portion of the outer screw cylinder 57, a plurality of, for example, two outer engagement holes 57E are provided in the rod guide 11-side end surface. Outer engagement pins 61D of an outer lever portion 61 constituting an adjustment lever 60 described later are inserted into the outer engagement holes 57E.

Further, one or more, for example, four notched portions 57F for allowing the barrel portion 57D to elastically deform in the radial direction are provided in the barrel portion 57D of the outer thread barrel 57. Each notch 57F extends in a cross shape from the axis of the outer threaded cylinder 57. Along with this, the cylindrical portion 57D of the outer threaded cylinder 57 is divided into four bent pieces at intervals of 90 degrees in the circumferential direction. This allows the cylindrical portion 57D of each bent piece to be elastically deformed more easily than the cylindrical shape. In other words, it is possible to suppress a decrease in the torque value required for tightening or loosening the inner screw body 58, which will be described later.

The outer threaded cylinder 57 is disposed in the large diameter portion 52A by screwing the external threaded portion 57A to the internal threaded portion 52C of the reduced-side flow passage 52. Thereby, the outer threaded tube 57 presses the biasing member 55 to apply a set load thereto.

The inner screw 58 is formed as a cylindrical body to be mounted in the outer screw cylinder 57. The inner screw 58 has an external thread portion 58A screwed to the internal thread portion 57B of the outer screw cylinder 57 on the outer peripheral side. When the screw portion 58A is screwed and fastened to the female screw portion 57B, the outer screw cylinder 57 (cylinder portion 57D) is enlarged in diameter to enlarge the notches 57F, and is formed as a tapered screw having an enlarged outer diameter toward the rod guide 11 side, similarly to the female screw portion 57B. Note that both the female thread portion 57B of the outer thread cylinder 57 and the male thread portion 58A of the inner thread body 58 may be formed as tapered threads, and only either one of the female thread portion 57B and the male thread portion 58A may be formed as tapered threads.

A communication passage 58B is formed through the center of the inner screw 58 in the axial direction. Further, a plurality of, for example, two inside engagement holes 58C are provided in the rod guide 11-side end surface of the inside screw body 58. The inner engagement holes 58C are inserted and fitted with inner engagement pins 62D of an inner lever portion 62 of an adjustment lever 60, which will be described later.

In the support member 5 configured as described above, the valve body 54 and the biasing member 55 can be disposed in the large diameter portion 52A by screwing the male thread portion 57A and the female thread portion 52C of the outer threaded cylinder 57 in a state where the valve body 54 and the biasing member 55 are disposed in the large diameter portion 52A of the reduced-side flow passage 52. On the other hand, the support member 56 can be brought into contact with and separated from the valve seat member 53, which is the other member, by rotating the outer threaded cylinder 57 by an adjustment lever 60, which will be described later. That is, the outer threaded tube 57 can change the damping force by adjusting the length of the biasing member 55.

After the damping force is adjusted by the outer screw tube 57, the support member 56 threadedly engages the female screw portion 57B of the outer screw tube 57 with the male screw portion 58A of the inner screw 58, thereby disposing the inner screw 58 in the outer screw tube 57. In this state, the inner screw body 58 is further screwed while the outer screw cylinder 57 is fixed in the rotational direction. At this time, the diameter of the cylindrical portion 57D of the outer threaded cylinder 57 can be enlarged by the threaded engagement of the female thread portion 57B and the male thread portion 58A formed by the tapered thread or by the notches 57F. Therefore, the male screw portion 57A of the outer threaded cylinder 57 is strongly pressed by the female screw portion 52C of the reduced-side flow passage 52 to restrict the rotation. Thereby, the support member 56 can be fixed in a state of being prevented from being loosened (loosened) after the adjustment of the damping force.

The through hole 59 is positioned in the rod guide 11 to communicate the inside and outside of the inner tube 6. The diameter dimension of the through hole 59 from the center line (axis) of the piston rod 9 to the center line of the through hole 59 is set to be the same as the diameter dimension from the center line (axis) of the piston rod 9 to the center line of the reduction-side flow passage 52 (support member 56), as in the through hole 18 of the first embodiment. The through hole 59 is formed as a stepped circular hole extending parallel to the piston rod 9. The through hole 59 is formed with a stepped portion 59A by expanding the diameter of the through hole 59 at the opening of the through hole 59 on the piston 8 side. The step portion 59A can accommodate a large diameter portion 61B of an outer rod portion 61 constituting an adjustment lever 60 described later. In addition, the step portion 59A abuts against the large diameter portion 61B protruding from the through hole 59 of the rod guide 11, and the pressure in the inner cylinder 6 prevents the adjustment rod 60 from dropping to the outside. An O-ring 59B for sealing between the small diameter portions 61A of the adjustment rod 60 (outer rod portion 61) is provided in the through hole 59.

The adjustment lever 60 is a member for adjusting the damping force of the narrowing-side valve mechanism 51, and is provided to the lever guide 11 constituting the closing member. The adjustment lever 60 is constituted by an outer lever portion 61 and an inner lever portion 62, which will be described later.

The outer rod portion 61 is formed as a stepped cylindrical body and is rotatably inserted into the through hole 59. The outer rod portion 61 is composed of a cylindrical small diameter portion 61A, a large diameter portion 61B having one end of the small diameter portion 61A and having a diameter enlarged at a distal end portion on the piston 8 side, a tool connecting portion 61C, for example, having a hexagonal shape, provided at the other end of the small diameter portion 61A outside the rod guide 11, and an outer joint pin 61D provided on the large diameter portion 61B. The large diameter portion 61B is formed as a bottomed cylindrical body accommodated in the stepped portion 59A of the through hole 59, and the inside thereof is an accommodation recess 61E accommodating the large diameter portion 62B of the inner rod portion 62.

The outer engagement pin 61D of the outer rod portion 61 is inserted into each outer engagement hole 57E of the outer threaded cylinder 57 of the support member 56 constituting the reduction-side valve mechanism 51. Therefore, the outer engagement pins 61D are configured to correspond to the number, the interval size, and the inner diameter size of the outer engagement holes 57E, that is, two outer engagement pins are provided so as to be inserted into the outer engagement holes 57E and engaged therewith in the rotational direction.

The inner rod portion 62 is inserted so as to be rotatable and slidable in the axial direction in the outer rod portion 61. The inner rod portion 62 is formed as a stepped cylinder in the same manner as the adjustment lever 19 of the first embodiment, and is configured by a small diameter portion 62A, a large diameter portion 62B, a tool connecting portion 62C, and an inner engagement pin 62D. The large diameter portion 62B can be accommodated in the accommodation recess 61E of the outer lever portion 61. A seal member (not shown) such as an O-ring is provided between the small diameter portion 62A of the inner rod portion 62 and the small diameter portion 61A of the outer rod portion 61.

The inner engagement pin 62D of the inner rod portion 62 is inserted into each inner engagement hole 58C of the inner screw 58 of the support member 56 constituting the reduced-side valve mechanism 51. Therefore, the inner engagement pins 62D are configured to correspond to the number, the interval, and the inner diameter of the inner engagement holes 58C, that is, two inner engagement pins are provided so as to be inserted into the inner engagement holes 58C and engaged therewith in the rotational direction.

Next, an example of a procedure for adjusting the damping force generated by the reduction-side valve mechanism 12 using the adjustment lever 60 will be described.

As shown in fig. 6, the piston rod 9 is extended greatly, and the piston 8 is disposed at an adjustment position close to the rod guide 11. After the piston 8 and the like are arranged at the adjustment position, the piston 8 (the piston rod 9) and the inner cylinder 6 (the outer cylinder 2) are relatively rotated, whereby the support member 56 and the adjustment rod 60 are coaxially arranged.

After the support member 56 is aligned with the adjustment rod 60, the fastening of the inner screw 58 to the outer screw cylinder 57 is released, and the outer screw cylinder 57 can be rotationally adjusted. First, while moving the adjustment rod 60 toward the piston 8, the outer engagement pins 61D of the outer rod portion 61 of the adjustment rod 60 are inserted into the outer engagement holes 57E of the outer threaded cylinder 57 of the support member 56. Further, the inner engagement pins 62D of the inner rod portion 62 constituting the adjustment lever 60 are inserted into the inner engagement holes 58C of the inner screw body 58 constituting the support member 56. Then, a tool such as a wrench is engaged with the tool coupling portion 61C of the outer lever portion 61 and the tool coupling portion 62C of the inner lever portion 62, respectively. In this state, the tool engaged with the inner rod portion 62 is rotated in a direction to loosen the inner screw body 58 while the tool engaged with the outer rod portion 61 is fixed. Thus, the inner screw body 58 can be loosened with respect to the outer screw cylinder 57, and the outer screw cylinder 57 can be elastically deformed in the diameter reduction direction to release the rotation prevention.

After the rotation prevention (locking) of the outer screw cylinder 57 is released, the outer lever 61 is rotated in an arbitrary direction by a tool. Thus, the outer threaded tube 57 is separated from or brought close to the valve seat member 53, and therefore the set load can be adjusted together with the installation length of the biasing member 55.

After the set load of the biasing member 55 is adjusted by the outer screw cylinder 57, the tool engaged with the outer rod portion 61 is rotated in a direction to tighten the inner screw body 58 while the tool engaged with the inner rod portion 62 is fixed. Thus, the inner screw body 58 can be press-fitted into the outer screw cylinder 57, and the outer screw cylinder 57 can be elastically deformed in the diameter expansion direction to prevent rotation.

Therefore, also in the third embodiment configured as described above, almost the same operational effects as those of the first embodiment described above can be obtained. In particular, according to the third embodiment, the support member 56 has the male screw portion 57A screwed to the inner peripheral surface of the reduced-size flow passage 52 on the outer peripheral side, and is composed of the cylindrical outer screw cylinder 57 having the female screw portion 57B on the inner peripheral side and the inner screw body 58 having the male screw portion 58A screwed to the female screw portion 57B of the outer screw cylinder 57 on the outer peripheral side. The outer threaded cylinder 57 is provided with four notches 57F for allowing the outer threaded cylinder 57 to elastically deform in the radial direction. In addition, when the internal thread portion 57B of the external thread cylinder 57 and the external thread portion 58A of the internal thread body 58 are screwed into the external thread cylinder 57, the notches 57F are formed as tapered threads that expand the diameter of the external thread cylinder 57 by expanding the notches 57F.

Therefore, by fixing the inner screw body 58 to the outer screw cylinder 57, the outer screw cylinder 57 can be prevented from rotating toward the large diameter portion 52A of the reduced-size flow passage 52. Further, by loosening the inner screw body 58 with respect to the outer screw cylinder 57, the rotation of the outer screw cylinder 57 with respect to the large diameter portion 52A of the reduced-size flow passage 52 can be released.

However, the adjustment lever 60 is constituted by an outer lever portion 61 for rotating the outer screw cylinder 57 and an inner lever portion 62 for rotating the inner screw body 58. This enables both the adjustment and the rotation prevention of the support member 56 to be performed from the outside of the rod guide 11.

Next, fig. 8 and 9 show a fourth embodiment of the present invention. The present embodiment is characterized in that the support member is screwed to the piston rod or the piston, and is provided so that the axial length of the cylinder of the biasing member can be adjusted by moving the support member in the axial direction of the cylinder by rotation. Further, in the closing member, a plurality of engagement pins that are engaged with the support member at an adjustment position where the piston approaches the closing member may be provided to extend in the cylinder axial direction. In the fourth embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof will be omitted.

In fig. 8, a piston 72 of a hydraulic shock absorber 71 according to a fourth embodiment is inserted (fitted) in an axially slidable manner in an inner tube 6. The piston 72 is formed as a thick cylindrical body, and a mounting shaft portion 73A of a piston rod 73 is inserted into a mounting hole 72A at a central position. A large-diameter circular recess 72B is formed on the bottom valve 7 side of the piston 72, and a female screw portion 72C is formed on the outer peripheral side of the circular recess 72B. The piston 72 is provided with a contraction side valve mechanism 74 and an extension side valve mechanism 81, which will be described later. The piston 72 has a rod-side end surface 72D facing the rod guide 11 and a bottom-side end surface 72E located at the bottom of the circular recess 72B and facing the base valve 7.

The piston rod 73 is formed as an elongated cylindrical body, and the proximal end side that enters the inner cylinder 6 is connected to the piston 72. Specifically, the base end side of the piston rod 73 is a small-diameter mounting shaft portion 73A, and the mounting shaft portion 73A is inserted into the mounting hole 72A of the piston 72 and fastened by the nut 10, thereby being integrally connected to the piston 72. On the other hand, in the piston rod 73, the male screw portion 73B is formed on the attachment shaft portion 73A side. The female screw portion 79A of the support member 79 described later is screwed to the male screw portion 73B. The male screw portion 86A of the support member 86 described later is screwed to the female screw portion 72C.

The contraction-side valve mechanism 74 is provided to the piston 72 and the piston rod 73. The reduction-side valve mechanism 74 includes a reduction-side flow passage 75, a valve seat member 76, a valve body 77, an urging member 78, and a support member 79, which will be described later.

The reduction-side flow passage 75 as a flow passage is provided in the piston 72, and is formed by a large diameter portion 75A and a small diameter portion 75B, as in the reduction-side flow passage 13 of the first embodiment. The seat member 76, which is the other member, is formed by a step portion between the large diameter portion 75A and the small diameter portion 75B of the reduced-side flow passage 75. The valve body 77 is disposed in the large diameter portion 75A of the reduced-side flow passage 75 and is provided at a position where the small diameter portion 75B is closed. The valve body 77 is normally seated on the valve seat member 76 by the biasing member 78. The biasing member 78 is disposed in the large diameter portion 75A of the reduction-side flow passage 75 together with the valve element 77. The biasing member 78 is formed of a compression coil spring, and biases the valve body 77 toward the seat member 76.

The support member 79, which is one member, supports an end portion of the biasing member 78 opposite to the valve body 77, and is provided in the piston rod 73. The support member 79 is formed of an annular plate facing the rod-side end surface 72D of the piston 72, and an internal thread portion 79A on the inner peripheral side is screwed to an external thread portion 73B of the piston rod 73. Thus, the support member 79 can move in the axial direction of the inner tube 6 by rotating, thereby adjusting the axial length dimension of the inner tube 6 of the biasing member 78 (increasing or decreasing the set load).

The support member 79 has an outer diameter exceeding the reduction-side flow passage 75. In addition, a joint hole 79B is provided at a position of the support member 79 corresponding to the reduction-side flow path 75. The engagement holes 79B can be provided at one location or a plurality of locations in the circumferential direction, and if the balance of the load acting during the adjustment work is taken into consideration, a plurality of locations are provided at equal intervals in the circumferential direction, for example, at two locations that are radially symmetrical. Since the engagement holes 79B are used as the flow paths of the hydraulic oil, the number of the engagement pins 80 to be described later can be increased.

In the support member 79, the valve body 77 and the biasing member 78 can be disposed in the large diameter portion 75A by screwing the internal thread portion 79A on the inner peripheral side to the external thread portion 73B of the piston rod 73 in a state where the valve body 77 and the biasing member 78 are disposed in the large diameter portion 75A. On the other hand, the support member 79 can be rotated by an engagement pin 80 described later, and can be brought into contact with and separated from the valve seat member 76 as the other member. That is, the support member 79 can adjust the length of the biasing member 78 to change the damping force.

Here, the reduction-side valve mechanism 74 of the fourth embodiment is configured such that an assembly of the reduction-side flow passage 75, the valve seat member 76, the valve body 77, and the biasing member 78 is disposed at a plurality of positions in the circumferential direction of the piston rod 73. In addition, the narrowing-side valve mechanism 74 is configured to support the respective urging members 78 by one support member 79 and adjust the length of the respective urging members 78 so as to be uniform.

The joint pin 80 on the reduction side is provided to extend in the axial direction of the inner tube 6 in the rod guide 11 as a closing member. Specifically, the engaging pin 80 is provided to protrude from the inner end surface 11B of the rod guide 11 toward the piston 72 side. The engagement pin 80 is engaged with the engagement hole 79B of the support member 79 at an adjustment position (position shown in fig. 9) at which the piston 72 approaches the rod guide 11. Here, if consideration is given to the balance of the load applied by the engaging pin 80 at the time of adjustment work, it is desirable to provide two or more radially symmetrical positions, as with the engaging holes 79B.

Next, an example of the adjustment step of generating the damping force by the reduction-side valve mechanism 74 configured as described above will be described. In this case, the piston rod 73 is greatly extended, and the piston 72 (the support member 79) is brought close to the rod guide 11. As shown in fig. 9, in the adjustment position where the piston 72 is close to the rod guide 11, the support member 79 is close to the inner end face 11B of the rod guide 11. When the piston 72 and the like are moved to the adjustment position, the piston 72 (the piston rod 73) and the inner cylinder 6 (the outer cylinder 2) are relatively rotated, the engagement holes 79B of the support members 79 are coaxially arranged with the engagement pins 80, and the engagement pins 80 are inserted into the engagement holes 79B.

After the engagement pins 80 are inserted into the engagement holes 79B, the piston 72 (piston rod 73) and the inner cylinder 6 (outer cylinder 2) are relatively rotated in any direction. Thus, the support member 79, in which the female screw portion 79A is screwed to the male screw portion 73B of the piston rod 73, moves in the axial direction along the crest, and thus the set load can be adjusted together with the attachment length dimension of the biasing member 78.

Next, the extension-side valve mechanism 81 is a mechanism that acts when the piston rod 73 extends, and is disposed on the piston 72. The extension-side valve mechanism 81 includes an extension-side flow passage 82, a valve seat member 83, a valve body 84, an urging member 85, and a support member 86, as in the case of the reduction-side valve mechanism 74. However, the extension-side valve mechanism 81 is different from the contraction-side valve mechanism 74 in the point of mounting the piston 72 with respect to the mounting direction thereof in the opposite axial direction and in the point of mounting structure of the support member 86 with respect to the piston 72.

Specifically, the extension-side support member 86 is formed as an annular plate and is disposed in the circular recess 72B of the piston 72. A male screw portion 86A screwed with the female screw portion 72C of the piston 72 is provided on the outer peripheral side of the support member 86. The inner peripheral side of the support member 86 extends to a position beyond the extension-side flow passage 82. In addition, the support member 86 is provided with an engagement hole 86B at a position corresponding to the extension-side flow passage 82, similarly to the support member 79. Thus, the support member 86 can be brought into contact with and separated from the seat member 83 by rotation of an engagement pin 87 described later.

An engagement pin 87 on the expansion side is provided extending in the axial direction of the inner tube 6 at the base portion 7A of the foot valve 7 as a closing member. Specifically, the engagement pin 87 is engaged with the engagement hole 86B of the support member 86 at the adjustment position where the piston 72 is close to the foot valve 7. The locking pin 88 is provided between the bottom cover 3 and the base 7A, and prevents the base 7A from rotating together with the support member 86. Instead of the lock pin 88, a wedge, a fastening screw, or the like may be used.

Therefore, in the fourth embodiment configured as described above, substantially the same operational effects as those of the first embodiment can be obtained. In particular, according to the fourth embodiment, the support member 79 on the reduction side is screwed to the male screw portion 73B of the piston rod 73, and is configured to be movable in the axial direction of the inner tube 6 by rotation to adjust the axial length of the inner tube 6 of the urging member 78. In the rod guide 11, an engagement pin 80 that engages with the support member 79 at an adjustment position where the piston 72 is close to the rod guide 11 is provided extending in the axial direction of the inner tube 6.

On the other hand, the extension-side support member 86 is provided to be screwed into the female screw portion 72C of the piston 72, and is movable in the axial direction of the inner tube 6 by rotation, whereby the axial length of the inner tube 6 of the urging member 85 can be adjusted. Further, at the base portion 7A of the foot valve 7, an engagement pin 87 that engages with the support member 86 at an adjustment position where the piston 72 is close to the base portion 7A is provided extending in the axial direction of the inner tube 6.

Therefore, the axial length of the plurality of biasing members 78 can be adjusted only by rotating the support member 79, and the axial length of the plurality of biasing members 85 can be adjusted only by rotating the support member 86. This makes it possible to easily perform the damping force adjustment operation. Further, since the engagement pins 80 and 87 can be formed as simple drive pins, it is possible to reduce the manufacturing cost, suppress the leakage of the working oil, and the like.

Next, fig. 10 and 11 show a fifth embodiment of the present invention. The present embodiment is characterized in that two types of valve mechanisms having different biasing forces (valve opening pressures) generated by the biasing member are provided in the piston, respectively. In the fifth embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

In fig. 10, a piston 92 of a hydraulic shock absorber 91 according to a fifth embodiment is slidably inserted (inserted) in an axial direction in an inner tube 6. The piston 92 is formed as a thick cylindrical body, and the mounting shaft portion 9A of the piston rod 9 is inserted into the mounting hole 92A at the center position. An annular recess 92B is formed on the rod guide 11 side of the piston 92 so as to surround the attachment hole 92A. The annular recess 92B has an external thread portion 92C on the inner circumferential side and an internal thread portion 92D on the outer circumferential side. A first valve mechanism 93 on the reduction side and a second valve mechanism 101 on the reduction side are provided in the piston 92.

The piston 92 can be provided with an extension-side valve mechanism. The valve mechanism that generates the damping force when the piston rod 9 is extended can be provided in the bottom valve 7, for example, in addition to the piston 92.

The first valve mechanism 93 on the reduction side is provided to the piston 92. The first valve mechanism 93 includes a reduction-side flow passage 94, a valve seat member 95, a valve body 96, an urging member 97, and a support member 98, which will be described later.

A reduction-side flow passage 94 as a flow passage is provided in the piston 92 and is formed by a large diameter portion 94A and a small diameter portion 94B. The seat member 95 as the other member is formed by a step portion between the large diameter portion 94A and the small diameter portion 94B of the reduced-side flow passage 94. The valve element 96 is disposed in the large diameter portion 94A of the reduced-side flow passage 94 and is provided at a position where the small diameter portion 94B is closed. The valve body 96 is normally seated on the valve seat member 95 by the urging member 97. The urging member 97 is disposed in the large diameter portion 94A of the reduced-side flow passage 94 together with the valve element 96. The biasing member 97 is formed of a compression coil spring, and biases the valve body 96 toward the valve seat member 95.

The support member 98, which is one member, is a member that supports the end of the biasing member 97 on the opposite side of the valve body 96, and is provided in the piston 92. The support member 98 is formed as an annular plate and is disposed in the annular recess 92B of the piston 92. The internal thread portion 98A of the support member 98 is screwed to the external thread portion 92C of the piston 92. The outer diameter of the support member 98 is set to a dimension slightly exceeding the urging member 97. An engagement hole 98B is provided at a position of the support member 98 corresponding to the reduction-side flow passage 94. Thus, the support member 98 can be brought into contact with and separated from the valve seat member 95 by rotation of a first engagement pin 100 described later. Since the engagement hole 98B is also used as a flow path for the hydraulic oil, it is desirable to provide the engagement hole in correspondence with the number of the reduction-side flow paths 94.

In the support member 98, the valve body 96 and the biasing member 97 can be disposed in the large diameter portion 94A by screwing the internal thread portion 98A on the inner peripheral side to the external thread portion 92C of the piston 92 in a state where the valve body 96 and the biasing member 97 are disposed in the large diameter portion 94A. On the other hand, the support member 98 can be rotated by the first engagement pin 100 to be brought into contact with and separated from the valve seat member 95 as the other member. That is, the support member 98 can change the damping force by adjusting the length of the biasing member 97.

Here, in the first valve mechanism 93 of the fifth embodiment, an assembly of the reduction-side flow passage 94, the valve seat member 95, the valve body 96, and the biasing member 97 is disposed at a plurality of positions in the circumferential direction of the annular recess 92B of the piston 92. In addition, the first valve mechanism 93 has a structure in which the urging members 97 are supported by one support member 98, and the length of the urging members 97 is adjusted to be uniform. The second valve mechanism 101 described later has the same configuration.

The through hole 99 is provided at a position that can be coaxial with the engagement hole 98B of the support member 98 of the lever guide 11. The through hole 99 is formed as a circular hole, and an O-ring 99A for sealing is provided between the first joint pins 100.

First joint pin 100 is inserted into through hole 99 so as to be movable in the axial direction. A flange portion 100A having a larger diameter than the through hole 99 is provided on the piston 92 side of the first joint pin 100, and the first joint pin 100 can be prevented from coming off by the flange portion 100A. The first engaging pin 100 is in insert-fit engagement with the engaging hole 98B of the support member 98 at the adjustment position where the piston 92 approaches the rod guide 11. Here, if the balance of the load acting on the first joint pin 100 at the time of adjustment work is considered, it is desirable to provide two or more radially symmetrical positions.

The second valve mechanism 101 on the reduction side is provided in the piston 92 in the same manner as the first valve mechanism 93 described above, and the flow path 102 on the reduction side includes a valve seat member 103, a valve body 104, an urging member 105, and a support member 106 as the other members. However, the second valve mechanism 101 differs from the first valve mechanism 93 in the urging force (elastic force) of the urging member 105, the shape of the support member 106, and the mounting structure of the support member 106 to the piston 92.

The urging force of the urging member 105 has an urging force larger than that of the urging member 97 of the first valve mechanism 93. In this case, the biasing member 105 is formed to have a larger wire diameter than the biasing member 97. On the other hand, the structure may be such that the applied force is different by changing the material.

The support member 106 of the second valve mechanism 101, which is one member, is a member that supports the end portion of the biasing member 105 on the opposite side of the valve body 104, and is therefore provided in the piston 92. The support member 106 is formed as an annular plate and is disposed in the annular recess 92B of the piston 92. The support members 106 have a larger inner diameter dimension than the outer diameter dimension of the support members 98. The male screw portion 106A on the outer peripheral side of the support member 106 is screwed to the female screw portion 92D of the piston 92. The inner diameter of the support member 106 is set to a dimension slightly exceeding the urging member 105. An engagement hole 106B is provided at a position of the support member 106 corresponding to the reduction-side flow path 102. Thus, the support member 106 can be brought into contact with and separated from the valve seat member 103 by rotation of a second engagement pin 108 described later. Since the engagement hole 106B is also used as a flow path for the hydraulic oil, it is desirable to provide the engagement hole in correspondence with the number of the reduction-side flow paths 102. Thus, the support member 106 can be brought into contact with and separated from the valve seat member 103 by the rotation of the second engagement pin 108.

The through hole 107 can be provided at a position coaxial with the engagement hole 106B of the support member 106 of the lever guide 11. The second engagement pin 108 is inserted into the through hole 107 so as to be movable in the axial direction, and is prevented from coming off by the flange portion 108A. The second engaging pin 108 is in insertion-fit engagement with the engaging hole 106B of the support member 106 at the adjustment position where the piston 92 approaches the rod guide 11. Here, like the first joint pin 100, the second joint pin 108 is desirably provided at two or more radially symmetrical positions in consideration of the balance of the load acting during the adjustment work.

Here, the biasing force of the biasing member 105 for closing the valve body 104 of the second valve mechanism 101 is set to be larger than the biasing force of the biasing member 97 for closing the valve body 96 of the first valve mechanism 93. Therefore, in the contraction stroke of the piston rod 9, when the piston 92 is displaced at a low speed in the axial direction, the pressure difference between the rod side oil chamber B and the bottom side oil chamber C becomes small, and at this time, the flow rate of the working oil flowing from the bottom side oil chamber C to the rod side oil chamber B becomes small. Therefore, in the first valve mechanism 93 and the second valve mechanism 101, which have the small biasing force, the first valve mechanism 93, which has the small biasing force, opens. Accordingly, the valve body 96 biased in the closing direction by the biasing member 97 can apply a damping force to the hydraulic oil flowing from the bottom side oil chamber C to the rod side oil chamber B, and the damping force can be reduced to suppress the contraction operation of the piston rod 9. The relationship between the displacement velocity V of the piston 92 and the damping force F at this time is shown by a straight line 109 in fig. 11.

In the contraction stroke of the piston rod 9, when the piston 92 is displaced at a high speed in the axial direction, the pressure difference between the rod side oil chamber B and the bottom side oil chamber C increases, and at this time, the flow rate of the working fluid flowing from the bottom side oil chamber C to the rod side oil chamber B increases. Therefore, the second valve mechanism 101 having a large biasing force opens in addition to the first valve mechanism 93 having a small biasing force. Accordingly, a damping force can be applied to the hydraulic fluid flowing from the bottom side oil chamber C to the rod side oil chamber B by the first valve mechanism 93 and the second valve mechanism 101, and the contraction operation of the piston rod 9 can be suppressed. The relationship between the displacement velocity V of the piston 92 and the damping force F at this time is shown by a straight line 110 in fig. 11.

Next, an example of the procedure of adjusting the damping force generated by the first valve mechanism 93 and the second valve mechanism 101 on the reduction side configured as described above will be described. In this case, the piston rod 9 is extended greatly, and the piston 92 (the support members 98 and 106) is brought close to the rod guide 11. First, a case of adjusting the damping force of the first valve mechanism 93 will be described. In the adjustment position in which the piston 92 is close to the rod guide 11, the bearing member 98 is close to the inner end face 11B of the rod guide 11. When the piston 92 or the like is moved to the adjustment position, the piston 92 (piston rod 9) and the inner cylinder 6 (outer cylinder 2) are relatively rotated, the engagement holes 98B of the support member 98 and the first engagement pins 100 are coaxially arranged, and the first engagement pins 100 are inserted into the engagement holes 98B.

After the first engagement pins 100 are inserted into the engagement holes 98B, the piston 92 (piston rod 73) and the inner cylinder 6 (outer cylinder 2) are relatively rotated in any direction. Thus, the support member 98 in which the male screw portion 92C of the piston 92 is screwed with the female screw portion 98A moves in the axial direction along the crest, and thus the set load can be adjusted together with the attachment length dimension of the urging member 97.

On the other hand, a case of adjusting the damping force of the second valve mechanism 101 will be described. When the piston 92 or the like is moved to the adjustment position, the piston 92 (the piston rod 9) and the inner cylinder 6 (the outer cylinder 2) are relatively rotated, the engagement holes 106B of the support member 106 and the second engagement pins 108 are coaxially arranged, and the second engagement pins 108 are inserted into the engagement holes 106B.

After the second engagement pins 108 are inserted into the engagement holes 106B, the piston 92 (piston rod 73) and the inner cylinder 6 (outer cylinder 2) are relatively rotated in any direction. Thus, the support member 106, which is screwed with the female screw portion 92D and the male screw portion 106A of the piston 92, moves in the axial direction along the crest, so that the set load can be adjusted together with the attachment length dimension of the biasing member 105.

Therefore, in the fifth embodiment configured as described above, almost the same operational effects as those of the above-described embodiments can be obtained. In particular, according to the fifth embodiment, as in the fourth embodiment, the axial length dimension of the plurality of biasing members 97 can be adjusted by relatively rotating only the support member 98, and the axial length dimension of the plurality of biasing members 105 can be adjusted by relatively rotating only the support member 106. This makes it possible to easily perform the damping force adjustment operation. The first valve mechanism 93 and the second valve mechanism 101 having different damping forces can be adjusted.

Next, fig. 12 shows a sixth embodiment of the present invention. The present embodiment is characterized in that the closing member is provided with a cover for covering the opposite end of the rod piston. In the sixth embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof will be omitted.

In fig. 12, a cover 111 is provided to the lever guide 11 as the blocking member. The cover 111 is formed as a covered cylindrical body, and covers the end of the adjustment rod 19 opposite to the piston 8. The cover 111 covers the outer end of the adjustment lever 19, and the flange 111A on the opening side is fixed to the outer end surface 11C of the lever guide 11 with bolts 112. The cover 111 covers the adjustment rod 19 when the reduction-side valve mechanism 12 is not in use, thereby preventing the adjustment rod 19 from falling off to the outside.

Therefore, in the sixth embodiment configured as described above, almost the same operational effects as those of the first embodiment can be obtained. In particular, according to the sixth embodiment, the rod guide 11 is provided with the cover 111 that covers the end of the adjustment rod 19 on the opposite side of the piston 8. This prevents the adjustment lever 19 from falling off to the outside. The cover 111 can protect the adjustment lever 19 from external force.

Next, fig. 13 shows a seventh embodiment of the present invention. The present embodiment is characterized in that the valve seat member is provided so as to be capable of coming into contact with and separating from the support member by rotation. In the seventh embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof will be omitted.

In fig. 13, the reduction-side valve mechanism 121 according to the seventh embodiment is a member that acts when the piston rod 9 is reduced, and therefore a plurality of the reduction-side valve mechanisms can be arranged at predetermined intervals in the circumferential direction of the piston 8. The reduction-side valve mechanism 121 is provided to extend in the axial direction of the piston 8, and includes a reduction-side flow passage 122 including a large-diameter portion 122A, a small-diameter portion 122B, and a female screw portion 122C, a valve seat member 123 provided at an opening portion of the large-diameter portion 122A of the reduction-side flow passage 122, a valve body 124 seated on the valve seat member 123, an urging member 125 that urges the valve body 124 toward the valve seat member 123, and a support member 126 that supports an end portion of the urging member 125 on the opposite side of the valve body 124.

The valve seat member 123, which is one member, is provided in the large diameter portion 122A of the reduced-size flow passage 122. The valve seat member 123 is formed of a thick cylindrical body, and the outer peripheral side is a male screw portion 123A screwed to the female screw portion 122C of the reduced-side flow passage 122. A communication passage 123B penetrating in the axial direction is provided in the center of the valve seat member 123. Further, a plurality of, for example, two engagement holes 123D are provided in the valve seat member 123 at the end face 123C on the side of the stem guide 11. The engagement pins 19D of the adjustment lever 19 are inserted into and engaged with the respective engagement holes 123D. That is, each engagement hole 123D constitutes an engagement member together with the engagement pin 19D.

In the valve seat member 123, the valve body 124 and the biasing member 125 can be disposed in the large diameter portion 122A by screwing the external thread portion 123A on the outer peripheral side to the internal thread portion 122C in a state where the biasing member 125 and the valve body 124 are disposed in the large diameter portion 122A. On the other hand, the valve seat member 123 can be brought into contact with and separated from the support member 126, which is the other member, by rotating the adjustment lever 19. That is, the valve seat member 123 can change the damping force by adjusting the length of the biasing member 125.

The support member 126, which is the other member, is formed by a step portion between the large diameter portion 122A and the small diameter portion 122B of the reduction-side flow passage 122.

Therefore, also in the seventh embodiment configured as above, almost the same operational effects as those of the first embodiment can be obtained.

Next, fig. 14 shows an eighth embodiment of the present invention. The present embodiment is characterized in that the adjustment rod is movable relative to the closing member in the circumferential direction of the cylinder. In the eighth embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof will be omitted.

In fig. 14, the rod guide 131 as a blocking member includes an outer guide portion 132 and an inner guide portion 133. The outer guide 132 is formed of a stepped annular body and is disposed on the left end side of the outer cylinder 2 and the inner cylinder 6. The inner guide 133 is rotatably fitted to the inner periphery of the outer guide 132. On the other hand, the inner guide 133 is fixed to the outer guide 132 by a plurality of bolts 134 in addition to the adjustment work of the damping force (elastic force). An insertion hole 133A penetrating in the axial direction is formed at the center of the inner guide 133. A through hole 18 is provided at a radially intermediate position of the inner guide 133, and the adjustment rod 19 is inserted into the through hole 18.

The rod guide 131 can rotate the inner guide 133 relative to the outer guide 132 by removing each bolt 134. Thereby, the adjustment rod 19 can move relative to the rod guide 131 along the circumferential direction of the inner tube 6.

Therefore, also in the eighth embodiment configured as described above, substantially the same operational effects as those in the first embodiment can be obtained. In particular, according to the eighth embodiment, the adjustment rod 19 provided in the inner guide 133 can be moved in the circumferential direction with respect to the outer guide 132, the inner cylinder 6, and the like. Thus, even in a state where the hydraulic shock absorber 1 is attached to a structure on a wall surface, the adjustment rod 19 can be aligned with the contraction-side valve mechanism 12. The same applies to the extension side. As a result, the damping force (elastic force) can be easily adjusted.

Next, fig. 15 shows a ninth embodiment of the present invention. The present embodiment is characterized in that a double nut structure is used for preventing rotation of the support member. In the ninth embodiment, the same components as those in the third embodiment are denoted by the same reference numerals, and the description thereof will be omitted.

In fig. 15, the reduction-side valve mechanism 141 of the ninth embodiment is a mechanism that acts when the piston rod 9 is reduced, and a plurality of the reduction-side valve mechanisms are arranged at predetermined intervals in the circumferential direction of the piston 8. The reduction-side valve mechanism 141 includes a support member 142 at an opening of the large-diameter portion 52A of the reduction-side flow passage 52. The support member 142 is attached to the piston 8 in a rotation-prevented state by a double nut structure called a double nut.

The outer peripheral side of the support member 142 is a male screw portion 142A screwed to the female screw portion 52C of the reduced-side flow passage 52. On the other hand, a communication passage 142B penetrating in the axial direction is provided at the center of the support member 142. Further, a plurality of, for example, two inner engagement holes 142D are provided in the support member 142 at the end surface 142C on the side of the rod guide 11. The inner engagement pin 62D of the inner rod portion 62 is inserted into each inner engagement hole 142D. The inner engagement holes 142D constitute an engagement member together with the inner engagement pin 62D.

The fixing nut 143 is formed as an annular body, and has an inner peripheral side formed as a female screw portion 143A to be screwed with the male screw portion 142A of the support member 142. The fixing nut 143 has a plurality of, for example, two outer engagement holes 143B into which the outer engagement pins 61D of the outer rod portion 61 are inserted. The fixing nut 143 is fixed in a state of being rotated by being pressed by the rod-side end surface 8B of the piston 8 in a state where the support member 142 of the fixing nut 143 is screwed to the female screw portion 52C of the reduction-side flow passage 52.

That is, the support member 142 changes the damping force by adjusting the length of the biasing member 16 by screwing the male screw portion 142A to the female screw portion 52C of the reduction-side flow passage 52. After the adjustment of the biasing member 16 is completed, the support member 142 is fixed by the inner rod 62, and the fixing nut 143 is tightened by the outer rod 61. Thus, the support member 142 can be fixed to the rotation-prevented state using the thread portions of the male thread portion 142A and the female thread portion 52C and the double nut structure (double nut) of the fixing nut 143.

Therefore, in the ninth embodiment configured as described above, almost the same operational effects as those of the third embodiment can be obtained.

In the first embodiment, an example will be described in which the engagement hole 17D of the support member 17 is formed as a bottomed circular hole, and the engagement pin 19D of the adjustment lever 19 is formed in a cylindrical shape. However, the present invention is not limited thereto, and the engaging hole and the engaging pin may be formed in other shapes than a circle, for example, a double-chamfered shape, a hexagonal shape, and the like. This structure can be similarly applied to the other embodiments.

In the first embodiment, the case where the

support members

17 and 25 are formed as thick cylindrical bodies is exemplified. However, the present invention is not limited to this, and for example, the support member may be formed in a double-chamfered shape (elliptical shape) in which the support member is chamfered along the opposite both surfaces with the axis therebetween. In this case, the double-chamfered support member forms a gap between the chamfered portion thereof and the female screw portion 13C of the reduction-side flow passage 13. This allows the double-chamfered support member to omit the communication path. This structure can be applied to the valve seat member 123 of the other embodiment and the seventh embodiment.

In the embodiments, the hydraulic shock absorber 1 is installed on the wall surface of the building by way of example. However, the present invention is not limited to this, and can be applied to, for example, a shock absorber used in a railway vehicle, a four-wheel automobile, and a two-wheel vehicle, a shock absorber used in various mechanical devices including general industrial devices, and various shock absorbers for absorbing objects requiring shock absorption.

As the damper according to the above-described embodiment, for example, a damper according to the following configuration can be conceived.

As a first aspect of the buffer, there is provided a buffer including: a cylinder barrel; a piston which is provided in the cylinder tube, divides the cylinder tube into two chambers, and slides on an inner peripheral surface of the cylinder tube; a piston rod connected to the piston and extending in an axial direction of the cylinder; a closing member that closes both ends of the cylinder tube; a flow path formed in the piston and communicating the two chambers; a valve seat member provided in the flow path; a valve body seated on the valve seat member; a biasing member that biases the valve body toward the valve seat member; a support member that supports an end portion of the biasing member on the opposite side to the valve body; at least one member of the valve seat member and the support member is provided to be capable of coming into contact with and separating from the other member by rotation, the closing member is provided with a through hole for communicating the inside and outside of the cylinder and an adjustment rod rotatably inserted into the through hole, and an engagement member is provided between the adjustment rod and the one member, and is engaged in the rotation direction at an adjustment position where the piston is close to the closing member and disengaged at a position where the piston is away from the adjustment position.

As a second aspect of the damper, according to the first aspect, the adjustment rod is movable relative to the closing member along a circumferential direction of the cylinder.

As a third aspect of the damper, according to the first or second aspect, the one member is composed of a cylindrical outer cylinder having an outer thread portion on an outer circumferential side thereof to be screwed to an inner circumferential surface of the flow passage, and an inner screw having an inner thread portion on an inner circumferential side thereof to be screwed to the inner thread portion of the outer cylinder, and the outer cylinder is provided with one or more notches for allowing the outer cylinder to be elastically deformed in a radial direction, and at least one of the inner thread portion of the outer cylinder and the outer thread portion of the inner screw is formed as a tapered thread for enlarging a diameter dimension of the outer cylinder when the inner screw is screwed to the outer cylinder.

As a fourth aspect of the damper, according to any one of the first to third aspects, a stepped portion is formed by expanding the through hole in the opening portion of the through hole on the piston side, a large diameter portion is formed by expanding the adjusting rod in the diameter at the distal end portion on the piston side, and the large diameter portion is accommodated in the stepped portion when the adjusting rod is not in use.

As a fifth mode of the damper, according to any one of the first to fourth modes, a cover is provided to the closing member so as to cover an end portion of the adjusting rod on the side opposite to the piston.

As a sixth aspect of the buffer, there is provided a buffer having: a cylinder barrel; a piston which is provided in the cylinder tube, divides the cylinder tube into two chambers, and slides on an inner peripheral surface of the cylinder tube; a piston rod connected to the piston and extending in an axial direction of the cylinder; a closing member that closes both ends of the cylinder tube; a plurality of flow paths formed in the piston and communicating the two chambers with each other; a valve seat member provided in one of the plurality of flow paths; a valve body seated on the valve seat member; a biasing member that biases the valve body toward the valve seat member; a support member that supports an end portion of the biasing member on the opposite side to the valve body; the support member is screw-coupled to the piston rod or the piston, and is provided so as to be movable in the axial direction of the cylinder tube by rotation to adjust the axial length of the cylinder tube of the urging member, and in the closing member, an engagement pin that engages with the support member at an adjustment position where the piston is close to the closing member is provided so as to extend in the axial direction of the cylinder tube.

The present invention is not limited to the above-described embodiments, and includes various modifications. For example, the above-described embodiments are described in detail to facilitate understanding of the present invention, and are not necessarily limited to embodiments having all of the configurations described. Further, a part of the configuration of one embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of one embodiment. Further, a part of the structures of the respective embodiments can be added, deleted, and replaced with another structure.

The application claims priority based on the Japanese patent application No. 2019-Buck 142940 applied on 8/2/2019. The entire disclosures of the specification, claims, drawings and summary of the specification, including the japanese laid-open application No. 2019-142940, filed 2019, 8, 2, are incorporated herein by reference in their entirety.

Description of the reference numerals

1. 31, 71, 91 hydraulic shock absorbers (shock absorbers) 3, 32 bottom covers (closing members) 6 inner tube (cylinder) 6A inner peripheral surface 7, 33 bottom valves (closing members) 8, 72, 92 pistons 9, 73 piston rods 11, 131 rod guides (closing members) 12, 34, 51, 74, 121, 141 narrowing side valve mechanisms 13, 35, 52, 75, 94, 102, 122 narrowing side flow passages (flow passages) 14, 22, 36, 53, 76, 83, 95, 103 seat members (the other members) 15, 23, 37, 54, 77, 84, 96, 104, 124 valve bodies 16, 24, 38, 55, 78, 85, 97, 105, 125 urging members 17, 25, 39, 56, 79, 86, 98, 106, 126, 142 support members (one member) 17D, 25D, 39D, 123D engagement holes (engagement members) 18, 26, 40, 59, 99, 107, through holes 19, 27, 41, 60 adjustment rods 19D, 123D, 27D, 41D engagement pins (engagement members) 20, 81 extension-side valve mechanisms 21, 82 extension-side flow passage (flow passage) 57 external screw thread portion 57B internal screw thread portion 57E, 143B external engagement hole (engagement member) 57F notched portion 58A external screw thread portion (tapered screw thread) 58C, 142D internal engagement hole (engagement member) 61D external engagement pin (engagement member) 62D internal engagement pin (engagement member) 79B, 86B, 98B, 106B engagement hole (engagement member) 80, 87 engagement pin 93 first valve mechanism 100 first engagement pin (engagement pin) 101 second valve mechanism 108 second engagement pin (engagement pin) 111 cover 123 valve seat member (member) B rod-side oil chamber C bottom oil chamber.

Claims

1. A buffer, comprising:

a cylinder barrel;

a closing member that closes both ends of the cylinder tube;

a flow path formed in the piston and communicating between the two chambers;

a valve seat member provided in the flow path;

a valve body seated on the valve seat member;

a biasing member that biases the valve body toward the valve seat member;

a support member that supports an end portion of the biasing member located on the opposite side of the valve body;

at least one member of the valve seat member and the support member is provided so as to be capable of coming into contact with and separating from the other member by rotation,

the blocking member is provided with a through hole for communicating the inside of the cylinder tube with the outside and an adjusting rod rotatably inserted into the through hole,

the piston is engaged with the one member in the rotational direction at an adjustment position close to the closing member, and disengaged at a position away from the adjustment position.

2. The buffer of claim 1,

the adjustment rod is movable relative to the closing member along a circumferential direction of the cylinder.

3. The buffer of claim 1 or 2,

the one member includes:

a cylindrical outer threaded cylinder having an external threaded portion on an outer circumferential side thereof, which is screwed to an inner circumferential surface of the flow path, and an internal threaded portion on an inner circumferential side thereof;

an inner screw body having, on an outer peripheral side, a male screw portion that is screwed into the female screw portion of the outer screw cylinder;

one or more notch portions for allowing the outer threaded cylinder to elastically deform in the radial direction are provided in the outer threaded cylinder,

the notch portion is formed as a tapered thread that expands the diameter of the outer threaded cylinder when the inner threaded body is screwed to the outer threaded cylinder by at least one of the internal thread portion of the outer threaded cylinder and the external thread portion of the inner threaded body.

4. The buffer according to any one of claims 1 to 3,

a step portion is formed by expanding the diameter of the through hole at the opening portion of the through hole on the piston side,

a large diameter portion is formed by expanding the diameter of the front end portion of the adjusting rod on the piston side,

when the adjustment lever is not in use, the large diameter portion is accommodated in the stepped portion.

5. The buffer according to any of claims 1 to 4,

the closing member is provided with a cover that covers an end of the adjustment rod that is located on the opposite side of the piston.

6. A buffer, comprising:

a cylinder barrel;

a closing member that closes both ends of the cylinder tube;

a valve seat member provided in one of the plurality of flow paths;

a valve body seated on the valve seat member;

a biasing member that biases the valve body toward the valve seat member;

the support member is screw-engaged with the piston rod or the piston, and is provided so as to be movable in the axial direction of the cylinder by being rotated so that the axial length of the cylinder of the force application member can be adjusted,

in the closing member, an engagement pin that engages with the support member at an adjustment position of the piston near the closing member is provided to extend in the axial direction of the cylinder tube.