JP2021017900A - Shock absorber - Google Patents

Abstract

To provide a shock absorber which enables easy change of arrangement of a cylinder and a tank.SOLUTION: A shock absorber A includes: a cylinder 1; a piston which is inserted into the cylinder 1 so as to be movable in an axial direction; a piston rod connected to the piston and protruding to the outside of the cylinder 1 at one end; a tank 4 which is attached to the outer side of the cylinder 1 in such a way so as to be rotatable in its circumferential direction and in which an interior communicates with the cylinder 1; and a fixture J which fixes the tank 4 to a given circumferential position at an outer periphery of the cylinder 1.SELECTED DRAWING: Figure 2

Description

The present invention relates to improvements in shock absorbers.

Conventionally, a cylinder that stores a liquid such as hydraulic oil inside, a piston rod that goes in and out of this cylinder, and an external cylinder are attached to the shock absorber that is interposed between the body of the motorcycle and the rear wheels. Some of them are provided with a tank whose inside is communicated with the inside of the cylinder, and the liquid moves between the cylinder and the tank when the piston rod expands and contracts the shock absorber that goes in and out of the cylinder.

In a shock absorber provided with such an external tank, a cylinder composite member is formed by integrally molding a cylinder, a bracket for connecting the cylinder to the vehicle body or the rear wheel, and a tank fitting portion into which the tank is screwed. (For example, Patent Document 1), a cylinder composite member in which a cylinder, a bracket, and a tank are integrally formed is formed (for example, Patent Document 2). According to this configuration, the number of shock absorber parts can be reduced, and the cylinder composite member can be manufactured by a method having excellent mass productivity such as casting.

Japanese Unexamined Patent Publication No. 8-270713, FIG. Japanese Unexamined Patent Publication No. 2008-267551, FIG.

Here, in the above-mentioned conventional shock absorber, the positional relationship between the cylinder and the tank when the shock absorber is attached to the motorcycle is determined. For example, the tank is in front, side, and rear of the cylinder when viewed from the rider of the motorcycle. Etc., it is arranged at an arbitrary position determined in advance. However, in the above-mentioned conventional shock absorber, the arrangement of the cylinder and the tank cannot be changed after the cylinder composite member is manufactured, and it is necessary to remake the cylinder composite member in order to change the arrangement.

Therefore, for example, when the shock absorbers are attached to the front wheels and the rear wheels of the four-wheel buggy, or when it is desired to change the arrangement of the cylinder and the tank according to the position of the shock absorber in the vehicle, the cylinder composite member is cast. In this case, it is necessary to make molds for each type of cylinder and tank arrangement, which is very troublesome. In addition, it takes time and effort to make different cylinder composite members by cutting with different arrangements of cylinders and tanks.

Therefore, an object of the present invention is to provide a shock absorber whose arrangement of a cylinder and a tank can be easily changed.

A shock absorber that solves the above problems is mounted on the outside of the cylinder so as to be rotatable in the circumferential direction, and at an arbitrary position in the circumferential direction of the outer circumference of the cylinder with a tank whose inside is communicated with the inside of the cylinder. It is equipped with a fixture to fix it. As a result, if the tank is not fixed by the fixture, the operator can move the tank to an arbitrary position in the circumferential direction of the outer circumference of the cylinder. Further, if the operator fixes the tank using a fixture while the tank is at an arbitrary position, the tank can be positioned at the arbitrary position. Therefore, it is easy to change the arrangement of the cylinder and the tank.

Further, the shock absorber is provided with a guide cylinder that is rotatably mounted on the outer periphery of the cylinder in the circumferential direction, a tank is provided integrally with the guide cylinder, and a fixture is screwed onto the outer periphery of the cylinder. It may have a screw ring and a flange protruding radially outward from the outer circumference of the cylinder, and the guide cylinder may be sandwiched between the screw ring and the flange from both sides in the axial direction to prevent the guide cylinder from rotating in the circumferential direction with respect to the cylinder. In this way, it is easy to fix the tank at an arbitrary position in the circumferential direction of the outer circumference of the cylinder.

Further, the shock absorber is stopped by the guide cylinder between the seal rings provided on both ends of the guide cylinder in the axial direction on the outer circumference of the cylinder and the guide cylinder and the screw ring on the outer circumference of the cylinder. A washer that is mounted in the state may be provided so that each seal ring is compressed between the guide cylinder and the flange or washer when the screw ring is tightened. In this way, it is possible to prevent the O-ring from being twisted when the screw ring and the guide cylinder are rotated, and it is possible to facilitate the rotation operation.

Further, in the shock absorber, tapered surfaces are formed on the inner circumferences of both ends in the axial direction of the guide cylinder so as to increase the diameter toward one end or the other end of the guide cylinder, respectively, and a seal ring is formed between the tapered surface and the cylinder. May be housed in. In this way, when the seal ring is compressed, it is pressed against the cylinder by the tapered surface, so that the sealability can be improved.

Further, the shock absorber includes a cap member that closes one end in the axial direction of the cylinder, and an annular screw portion in which the cap member is screwed onto the inner circumference of the cylinder, and a lid portion that closes one end of the screw portion. , It has a flange which is arranged on the outer periphery of the lid portion and whose outer diameter is larger than the outer diameter of the screw portion, and this flange may be a flange of a fixture. In this way, the number of seal rings can be reduced because both the cylinder and the guide cylinder and the cylinder and the cap member can be sealed by the seal ring sandwiched between the flange and the guide cylinder.

Further, in the shock absorber, the cap member may have a cylinder portion extending in the axial direction from the other end of the screw portion, and a rib abutting on the inner circumference of the cylinder may be formed on the outer circumference of the cylinder portion. In this way, since the cylinder is reinforced by the cylinder portion of the cap member, the structure can be made advantageous against bending and prying load.

Further, the shock absorber may be provided with a lock piece that is arranged on the cap member side of the piston and that separates the inside and outside of the cylinder when inserted into the cylinder. In this way, the tubular portion forms a hydraulic lock mechanism together with the lock piece, and the impact at the time of maximum contraction of the shock absorber can be alleviated.

According to the shock absorber according to the present invention, the arrangement of the cylinder and the tank can be easily changed.

It is the schematic which showed the vertical cross section of the shock absorber which concerns on one Embodiment of this invention simplified. It is a front view which showed the part of the shock absorber which concerns on one Embodiment of this invention by partially cutout. (A) is a front view which showed a part of the cap member in the shock absorber which concerns on one Embodiment of this invention. (B) is a bottom view of the cap member of (a). It is an enlarged view which showed the part of FIG. 2 enlarged.

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

The shock absorber A according to the embodiment of the present invention shown in FIG. 1-4 is used for a suspension for suspending the wheels of a four-wheel buggy. In the following description, "upper" and "lower" in a state where the shock absorber A according to the present embodiment is attached to the vehicle are simply referred to as "upper" and "lower" unless otherwise specified. Needless to say, the shock absorber according to the present invention may be used in a vehicle other than the four-wheel buggy, and may be interposed between the vehicle body and the rear wheels of the motorcycle, for example.

FIG. 1 is a simplified schematic view of the shock absorber A according to the present embodiment. As shown in FIG. 1, in the shock absorber A, the cylinder 1, the piston 2 slidably inserted into the cylinder 1, and the piston 2 are connected to the upper end portion, and the lower end projects out of the cylinder 1. It includes a piston rod 3 and a tank 4 externally attached to the cylinder 1. Spring receivers 10 and 30 are provided on the outer circumference of the cylinder 1 and the outer circumference of the lower end of the piston rod 3 projecting to the outside of the cylinder 1, respectively, and a suspension spring S is interposed between the spring receivers 10 and 30, respectively. ing.

A cap member 5 is mounted on the upper end of the cylinder 1. Brackets 52 and 31 are provided at the lower ends of the cap member 5 and the piston rod 3, respectively, and the shock absorber A is interposed between the vehicle body and the wheels via these brackets 52 and 31. Then, when the wheels vibrate up and down with respect to the vehicle body, such as when the vehicle travels on an uneven road surface, the piston rod 3 moves in and out of the cylinder 1, the shock absorber A expands and contracts, and the suspension spring S expands and contracts. When the shock absorber A expands and contracts like this, the piston 2 moves up and down (axially) in the cylinder 1.

As described above, the cap member 5 is mounted on the upper end of the cylinder 1, and the upper end of the cylinder 1 is closed by the cap member 5. On the other hand, an annular rod guide 11 is provided at the lower end of the cylinder 1. The piston rod 3 is inserted inside the rod guide 11 and enters and exits the cylinder 1 while being pivotally supported by the rod guide 11. The rod guide 11 is provided with a sealing member 12 that seals the outer periphery of the piston rod 3. As a result, the top and bottom of the cylinder 1 are closed in a liquid-tight manner.

The inside of the cylinder 1 is divided into an extension side chamber L1 and a compression side chamber L2 by a piston 2, and each of these is filled with a liquid such as hydraulic oil. The extension side chamber referred to here is a room that is compressed by the piston when the shock absorber is extended out of the two chambers partitioned by the piston, and is formed on the lower side of the piston 2 in the present embodiment. There is. On the other hand, the compression side chamber is the chamber of the two chambers partitioned by the piston, which is compressed by the piston when the shock absorber contracts, and is formed on the upper side of the piston 2 in the present embodiment. ..

The piston 2 is formed with an extension side passage 2a and a compression side passage 2b that communicate the extension side chamber L1 and the compression side chamber L2, and is attached with an extension side valve 20 and a compression side valve 21 that open and close these. The extension valve 20 is an extension damping element and opens when the shock absorber A is extended to give resistance to the flow of liquid from the extension chamber L1 to the compression side chamber L2 through the extension passage 2a. On the other hand, the compression side valve 21 is a compression side check valve, which opens when the shock absorber A contracts to allow the flow of liquid from the compression side chamber L2 to the extension side chamber L1 through the compression side passage 2b.

Subsequently, a liquid chamber L3 filled with the same liquid as in the cylinder 1 and a gas chamber G filled with compressed gas are formed in the tank 4, and these are slidably inserted into the tank 4. It is partitioned by the free piston 40. The liquid in the liquid chamber L3 is appropriately changed according to the liquid in the cylinder 1. Further, the gas in the gas chamber G can be appropriately selected from air, nitrogen gas and the like. Further, the tank 4 is connected to the cylinder 1 via a guide cylinder 7 which will be described in detail later, and a valve case (not shown) is attached to a bridge portion 70 connecting the guide cylinder 7 and the tank 4. There is.

A suction passage 6a and a discharge passage 6b that communicate the compression side chamber L2 and the liquid chamber L3 are formed in the valve case, and a suction valve 60 and a damping valve 61 that open and close these are attached. The suction valve 60 is a check valve on the extension side and opens when the shock absorber A is extended to allow the flow of liquid from the liquid chamber L3 to the compression side chamber L2 through the suction passage 6a. On the other hand, the damping valve 61 is a damping element on the compression side and opens when the shock absorber A contracts to give resistance to the flow of liquid from the compression side chamber L2 to the liquid chamber L3 through the discharge passage 6b.

According to the above configuration, when the piston rod 3 retracts from the cylinder 1 and the shock absorber A extends, the piston 2 moves downward in the cylinder 1 to compress the extension side chamber L1. Then, the liquid in the extension side chamber L1 opens the extension side valve 20 and moves to the compression side chamber L2 through the extension side passage 2a. A resistance is provided by the extension valve 20 to the flow of the liquid, and the shock absorber A exerts an extension damping force due to the resistance. Further, when the shock absorber A is extended, the suction valve 60 is opened, and the liquid corresponding to the volume of the piston rod discharged from the cylinder 1 is supplied from the liquid chamber L3 to the compression side chamber L2 through the suction passage 6a. As a result, the free piston 40 advances and the gas chamber G expands.

On the contrary, when the piston rod 3 invades the cylinder 1 and the shock absorber A contracts, the piston 2 moves upward in the cylinder 1 and compresses the compression side chamber L2. Then, the liquid in the compression side chamber L2 opens the compression side valve 21 and moves to the extension side chamber L1 through the compression side passage 2b. Further, when the shock absorber A contracts, the liquid in the compression side chamber L2 opens the damping valve 61, and the liquid corresponding to the volume of the piston rod that has entered the cylinder 1 is discharged from the compression side chamber L2 to the liquid chamber L3 through the discharge passage 6b. To. A resistance is provided by the damping valve 61 to the flow of the liquid, and the shock absorber A exerts a damping force on the compression side due to the resistance. Further, when the liquid is discharged from the compression side chamber L2 to the liquid chamber L3, the free piston 40 retracts and the gas chamber G shrinks.

In the present embodiment, the compression side valve 21 is a check valve, but this may be a damping element. Further, as a damping element that gives resistance to the flow of liquid flowing between the extension side chamber L1 and the compression side chamber L2, or the compression side chamber L2 and the liquid chamber L3, a leaf valve, an orifice, a combination thereof, or the like can be used.

Further, in the present embodiment, the liquid chamber L3 and the gas chamber G in the tank 4 are partitioned by the free piston 40, but a bladder, a bellows, or the like may be provided instead of the free piston 40. Further, in the present embodiment, the liquid chamber L3 is pressurized with the compressed gas sealed in the gas chamber G. Since the liquid chamber L3 communicates with the compression side chamber L2 and the compression side chamber L2 communicates with the extension side chamber L1, the inside of the cylinder 1 is also pressurized by the compressed gas. The means for pressurizing is not limited to the compressed gas, and a mechanical spring such as a coil spring may be used.

Further, in the present embodiment, the piston rod 3 extends from one side of the piston 2 to the outside of the cylinder 1, and the shock absorber A is a single rod type. Then, the tank 4 functions as a reservoir tank that compensates for the volume of the piston rod 3 entering and exiting the cylinder 1. However, as long as the liquid moves between the cylinder and the tank when the shock absorber moves in the cylinder with the piston, the configuration and mode of the hydraulic circuit of the shock absorber according to the present invention are appropriately changed. it can.

Specifically, the shock absorber may be of the double rod type, and the piston rods may be provided on both sides of the piston. Further, the shock absorber may be a double cylinder type, and the cylinder may have a multi-tube structure. Further, the shock absorber may be upright, and the piston rod may be arranged on the upper side (vehicle body side) and the cylinder may be arranged on the lower side (wheel side). Further, the shock absorber may be a one-sided shock absorber, and exerts only one of the damping force on the extension side and the damping force on the compression side.

Next, a specific structure of a portion connecting the cylinder 1 and the tank 4 in the shock absorber A according to the present embodiment will be described.

As shown in FIG. 2, the cap member 5 is provided on the screw portion 50 screwed to the inner circumference of the upper end of the cylinder 1, the lid portion 51 that closes the upper end of the screw portion 50, and the upper side of the lid portion 51. Arranged on the outer periphery of the bracket 52 and the lid 51, the outer diameter is larger than the outer diameter of the screw portion 50, and the annular flange 53 with which the upper end of the cylinder 1 abuts and the lower end of the screw portion 50 extend downward. It has a cylinder portion 54 inserted inside the cylinder 1. The outer diameter of the flange 53 is larger than the outer diameter of the cylinder 1 that abuts on the flange 53, and when the cap member 5 is attached to the cylinder 1, the outer peripheral portion of the flange 53 projects radially outward from the cylinder 1.

Further, as shown in FIG. 3, a plurality of ribs 54a along the axial direction are formed on the outer periphery of the tubular portion 54 so as to be arranged in the circumferential direction, and are recessed along the axial direction between adjacent ribs 54a and 54a. 54b can be made. When the cap member 5 is attached to the cylinder 1, the tip of each rib 54a comes into contact with the inner circumference of the cylinder 1. Further, the recess 54b creates a gap between the cylinder portion 54 and the cylinder 1. FIG. 2 shows a cross section when the cap member 5 is vertically cut at the recess 54b.

As shown in FIG. 1, a lock piece 33 is provided on the upper end portion of the piston rod 3 and above the piston 2 so as to face the tubular portion 54. Then, when the amount of contraction of the shock absorber A becomes large and the piston 2 approaches the cap member 5, the lock piece 33 is inserted into the tubular portion 54. Then, the inside and outside of the cylinder portion 54 are partitioned by the lock piece 33, and the liquid inside the cylinder portion 54 is confined, that is, the hydraulic pressure is locked. As a result, the shock absorber A stops the contraction operation, and the impact at the time of the maximum contraction of the shock absorber A is alleviated by the hydraulic pressure locking effect.

As described above, in the present embodiment, the tubular portion 54 functions as a lock case and constitutes a hydraulic lock mechanism together with the lock piece 33 to alleviate the impact of the shock absorber A at the time of maximum contraction. Further, as described above, a plurality of ribs 54a are formed on the outer circumference of the cylinder portion 54, and the tip of each rib 54a abuts on the inner circumference of the cylinder 1. As a result, the cylinder 1 is reinforced by the cylinder portion 54, which is advantageous against bending and prying loads.

As shown in FIG. 2, the cylinder 1 includes a threaded portion 1a having a threaded groove formed on the outer periphery thereof, and an annular shaft portion 1b connected to the upper end of the threaded portion 1a and having no threaded groove on the outer periphery. A screw groove is formed on the inner circumference of the upper end of the annular shaft portion 1b so that the annular shaft portion 1b can be screwed with the screw portion 50 of the cap member 5. Further, an annular groove 1c along the circumferential direction is formed on the outer periphery of the annular shaft portion 1b and at the central portion in the axial direction. Further, the annular shaft portion 1b is formed with a plurality of through holes 1d penetrating the wall thickness in the circumferential direction (FIG. 2 shows only one through hole 1d).

One end of the through hole 1d opens inside the annular groove 1c. On the other hand, the other end of the through hole 1d faces the recess 54b formed along the axial direction on the outer circumference of the cylinder portion 54 of the cap member 5 mounted on the cylinder 1. As a result, the through hole 1d and the compression side chamber L2 are communicated with each other. That is, in the present embodiment, a plurality of ribs 54a along the axial direction are formed on the outer circumference of the cylinder portion 54 in the circumferential direction, and the tip of each rib 54a is brought into contact with the inner circumference of the cylinder 1. Therefore, the cylinder portion 54 The through hole 1d and the compression side chamber L2 can communicate with each other while reinforcing the cylinder 1.

Further, in the present embodiment, the number of through holes 1d and the number of recesses 54b are relatively prime, and even if any of the through holes 1d is blocked by the rib 54a, any of them is closed. Communication between the through hole 1d and the compression side chamber L2 is maintained so as to face the recess 54b. The number of through holes 1d and the number of recesses 54b can be freely changed as long as communication between the through holes 1d and the compression side chamber L2 is guaranteed.

Subsequently, an annular guide cylinder 7, a washer 8, and a screw ring 9 are attached to the outer periphery of the upper end portion of the cylinder 1 including the annular shaft portion 1b in this order from the upper side. The screw ring 9 is screwed onto the outer periphery of the threaded portion 1a of the cylinder 1, and the washer 8 and the guide cylinder 7 laminated on the upper side thereof are sandwiched and fixed between the screw ring 9 and the flange 53. The guide cylinder 7 is integrally provided with a bridge portion 70 projecting laterally from the side portion thereof and a tank fitting portion 71 arranged at the tip of the bridge portion 70 and to which the tank 4 is attached.

The guide cylinder 7 is slidably mounted on the outer periphery of the annular shaft portion 1b of the cylinder 1. Further, an annular groove 7a along the circumferential direction is formed on the inner circumference of the guide cylinder 7. The annular groove 7a is formed at a position facing the annular groove 1c of the cylinder 1 with the upper end of the guide cylinder 7 abutting against the flange 53. As a result, an annular gap C is formed between the guide cylinder 7 and the cylinder 1, and the annular gap C communicates with the compression side chamber L2 via the through hole 1d.

Further, the tank fitting portion 71 has a bottomed tubular shape, and the tank 4 is screwed onto the outer circumference of the tubular portion 71a, and a hole 71c that opens inside the tubular portion 71a is formed in the bottom portion 71b. Further, the bridge portion 70 is formed with a passage (not shown) connecting the hole 71c and the annular gap C, and the suction valve 60 and the damping valve 61 described above are provided in the valve case in the middle of the passage. The assembled valve case assembly 6 is mounted. As a result, the compression side chamber L2 in the cylinder 1 and the liquid chamber L3 in the tank 4 are communicated with each other through the through hole 1d, the annular gap C, the passage provided with the valve case assembly 6, and the hole 71c to allow the liquid to flow. It goes back and forth between the compression side chamber L2 and the liquid chamber L3.

In the present embodiment, the valve case assembly 6 is attached to the bridge portion 70, which is convenient for adjusting the damping force. However, the arrangement of the valve case assembly 6 can be changed as appropriate. For example, the valve case assembly 6 may be arranged in the tank 4. Further, when the lock piece 33 (FIG. 1) is abolished, the valve case assembly 6 may be arranged in the cylinder 1. Furthermore, the valve case assembly 6 itself may be abolished.

Subsequently, as shown in FIG. 4, a tapered surface 7b whose diameter gradually increases toward the upper end is formed on the inner circumference of the upper end portion of the guide cylinder 7. The tapered surface 7b, the outer circumference of the annular shaft portion 1b of the cylinder 1, and the portion surrounded by the lower end of the flange 53 are the seal accommodating portions. Then, in a state where the upper end of the guide cylinder 7 is abutted against the flange 53, the seal ring 72 is compressed and accommodated in the seal accommodating portion.

Similarly, a tapered surface 7c whose diameter gradually increases toward the lower end is formed on the inner circumference of the lower end portion of the guide cylinder 7. The tapered surface 7c, the outer circumference of the annular shaft portion 1b of the cylinder 1, and the portion surrounded by the upper end of the washer 8 are the seal accommodating portions. Then, in a state where the lower end of the guide cylinder 7 is abutted against the washer 8, the seal ring 73 is compressed and accommodated in the seal accommodating portion.

As a result, the liquid in the annular gap C is prevented from leaking from between the cylinder 1 and the guide cylinder 7. Further, the upper seal ring 72 prevents the liquid in the cylinder 1 from leaking from between the cylinder 1 and the cap member 5. That is, the upper seal ring 73 has two roles, one is to seal between the cylinder 1 and the guide cylinder 7, and the other is to seal between the cylinder 1 and the cap member 5.

Further, the washer 8 is prevented from rotating with respect to the guide cylinder 7. The configuration for this detent can be freely changed, but in the present embodiment, as shown in FIG. 2, the pin P standing at the lower end of the guide cylinder 7 functions as a detent and covers the outer circumference of the washer 8. It is inserted through the formed notch 8a. As a result, the washer 8 is allowed to move up and down (axially) with respect to the guide cylinder 7, but the rotation in the circumferential direction is prevented.

According to the above configuration, as the screw ring 9 is tightened, the washer 8 moves upward while its rotation is restricted by the pin P, and presses the guide cylinder 7 against the flange 53. As a result, the guide cylinder 7 is sandwiched and fixed between the screw ring 9 and the flange 53, and does not move with respect to the cylinder 1. On the other hand, when the screw ring 9 is loosened, the guide cylinder 7 can rotate around the shaft while being supported by the annular shaft portion 1b of the cylinder 1.

As described above, the tank 4 is fixed to the guide cylinder 7 and moves integrally with the guide cylinder 7. Therefore, when the screw ring 9 is loosened, the tank 4 can move around the outer circumference of the cylinder 1 in the circumferential direction while rotating the guide cylinder 7. Further, if the screw ring 9 is tightened, the tank 4 does not move with respect to the cylinder 1. As a result, if the operator loosens the screw ring 9 to move the tank 4 to an arbitrary position in the circumferential direction around the cylinder 1 and tightens the screw ring 9 in that state, the tank 4 is fixed at the arbitrary position. As described above, in the present embodiment, the screw ring 9 and the flange 53 function as a fixture J for fixing the tank 4 at an arbitrary position in the circumferential direction around the cylinder 1.

Further, when the screw ring 9 is tightened, the seal rings 72 and 73 are crushed between the tapered surface 7b and the flange 53, and between the tapered surface 7c and the washer 8, respectively. At this time, since the seal rings 72 and 73 are pressed against the cylinder 1 and the flange 53 or the washer 8 by the tapered surfaces 7b and 7c, the space between the cylinder 1 and the guide cylinder 7 and the space between the cylinder 1 and the flange 53 are ensured. It will be sealed. Further, since the washer 8 is stopped by the pin P, even if the screw ring 9 is rotated, a compressive load acts on the seal rings 72 and 73 only in the axial direction, and the seal rings 72 and 73 are not twisted.

Further, when the screw ring 9 is loosened, the washer 8 is separated from the flange 53, and the contact pressure between the tapered surfaces 7b and 7c and the seal rings 72 and 73 is reduced. On the other hand, the seal rings 72 and 73 have a predetermined tightening allowance with respect to the annular shaft portion 1b of the cylinder 1, and a predetermined contact pressure between the annular shaft portion 1b and the seal rings 72 and 73 is secured. Therefore, when the screw ring 9 is loosened to rotate the guide cylinder 7, the guide cylinder 7 rotates while leaving the seal rings 72 and 73 in place without rotating with respect to the cylinder 1.

As a result, the guide cylinder 7 can be easily rotated, and the seal rings 72 and 73 can be prevented from being twisted during the rotation. Furthermore, if the gas in the gas chamber G is degassed and the internal pressure thereof is set to about atmospheric pressure, the seal ring 72 prevents the liquid in the annular gap C from leaking even when the liquid is contained in the shock absorber A. , 73 can prevent it. As a result, the arrangement of the cylinder 1 and the tank 4 can be easily changed even after the shock absorber A is manufactured.

Further, in the present embodiment, a spring receiver 10 for supporting the upper end of the suspension spring S shown in FIG. 1 is also screwed on the outer circumference of the screwed portion 1a in the cylinder 1 and below the screw ring 9. .. As a result, the initial load of the suspension spring S can be adjusted by changing the axial position of the spring receiver 10 with respect to the cylinder 1. However, the method of adjusting the axial position of the spring receiver 10 is not limited to this. Further, the spring receiver 10 may be fixed to the outer circumference of the cylinder 1. In these cases, the axial length of the screwed portion 1a may be shorter than that shown in FIG.

The action and effect of the shock absorber A according to the embodiment of the present invention will be described below.

In the shock absorber A according to the present embodiment, the cylinder 1, the piston 2 movably inserted into the cylinder 1 in the axial direction, and the upper end (one end) connected to the piston 2 project out of the cylinder 1. The piston rod 3 is mounted on the outside of the cylinder 1 so as to be rotatable in the circumferential direction of the cylinder 1, and the inside of the tank 4 is communicated with the inside of the cylinder 1. The tank 4 is connected to the outer circumference of the cylinder 1 in the circumferential direction. It is equipped with a fixture J that fixes it at an arbitrary position.

As a result, if the tank 4 is not fixed by the fixture J, the operator can move the tank 4 to an arbitrary position in the circumferential direction of the outer circumference of the cylinder 1. Further, if the operator fixes the tank 4 by using the fixture J with the tank 4 at the arbitrary position, the tank 4 can be positioned at the arbitrary position. Therefore, the arrangement of the cylinder 1 and the tank 4 can be easily changed, and it is easy to change the arrangement of the cylinder 1 and the tank 4 not only at the time of manufacturing the shock absorber A but also after the manufacturing.

As a result, even when the shock absorber A is attached to the front wheels and the rear wheels of the four-wheel buggy, the arrangement of the cylinder 1 and the tank 4 can be appropriately changed according to the position of the shock absorber A in the vehicle. Further, in order to change the tank 4, it is only necessary to rotate the tank 4 to an arbitrary position in the circumferential direction of the cylinder 1 and fix it at that position. Therefore, the mold can be remade or cut separately as in the conventional cylinder composite member. It is less costly than before to prepare a shock absorber with a different arrangement of cylinder and tank because there is no member to do.

Further, the shock absorber A according to the present embodiment includes a guide cylinder 7 rotatably mounted on the outer periphery of the cylinder 1 in the circumferential direction. The tank 4 is integrally provided with the guide cylinder 7. Further, the fixture J has a screw ring 9 screwed onto the outer circumference of the cylinder 1 and a flange 53 protruding radially outward from the outer circumference of the cylinder 1, and the guide cylinder 7 is formed by the screw ring 9 and the flange 53. It is sandwiched from both sides in the axial direction to prevent the guide cylinder 7 from rotating in the circumferential direction with respect to the cylinder 1.

The term "integral" as used herein means a state in which a plurality of members (parts) are seamlessly and continuously integrated, and after the plurality of members are individually manufactured, they are bonded, welded, screwed, press-fitted, etc. Includes both in a state of being joined and integrated with. According to the above configuration, the tank 4 and the guide cylinder 7 move integrally, and when the tank 4 rotates in the circumferential direction of the cylinder 1, the guide cylinder 7 is rotated with respect to the cylinder 1. Then, the tank 4 can be fixed to the cylinder 1 by sandwiching the guide cylinder 7 between the screw ring 9 and the flange 53 and stopping the rotation of the guide cylinder 7 with respect to the cylinder 1. Therefore, it is easy to fix the tank 4 at an arbitrary position in the circumferential direction of the outer circumference of the cylinder 1.

Further, the shock absorber A according to the present embodiment is the outer circumference of the cylinder 1 and is provided at both ends in the axial direction of the guide cylinder 7, and the seal rings 72 and 73 and the outer circumference of the cylinder 1 and is the guide cylinder 7. A washer 8 mounted between the screw ring 9 and the screw ring 9 in a state where the guide cylinder 7 is prevented from rotating is provided. Then, when the screw ring 9 is tightened, one seal ring 72 is compressed between the guide cylinder 7 and the flange 53, and the other seal ring 73 is compressed between the guide cylinder 7 and the washer 8.

According to the above configuration, even when the liquid flowing back and forth between the cylinder 1 and the tank 4 passes between the cylinder 1 and the guide cylinder 7, the seal rings 72 and 73 can prevent the liquid from leaking. .. Further, since the washer 8 is prevented from rotating with respect to the guide cylinder 7 and moves only in the axial direction of the guide cylinder 7, the rotation is not transmitted to the seal rings 72 and 73 when the screw ring 9 is tightened. As a result, the seal rings 72 and 73 are not twisted when compressed, and the rotation operation of the screw ring 9 can be facilitated.

Further, according to the above configuration, if the screw ring 9 is loosened, the contact pressure between the seal rings 72 and 73 and the guide cylinder 7 is reduced. As a result, when adjusting the position of the tank 4 with respect to the cylinder 1, the guide cylinder 7 can rotate while leaving the seal rings 72 and 73 in place. That is, even when the guide cylinder 7 rotates with respect to the cylinder 1, the seal rings 72 and 73 can be suppressed from being twisted, and the rotation operation of the guide cylinder 7 (tank 4) can be facilitated.

Here, when the seal rings 72 and 73 are twisted, a wire is provided so that a part of the seal rings 72 and 73 is not stretched by the force of twisting the seal rings 72 and 73 to be bent or torn. It is necessary to take measures such as adopting a seal ring with a large diameter. On the other hand, according to the above configuration, since the seal rings 72 and 73 can be suppressed from being twisted, even a seal ring having a small wire diameter can be adopted. Therefore, according to the above configuration, the diameter of the guide cylinder 7 can be reduced.

However, depending on the type of seal ring to be adopted, it is not necessary to bring the seal ring that seals between the cylinder 1 and the guide cylinder 72 into contact with the flange and the washer. In such a case, the washer 8 and its detent (pin P in the present embodiment) may be omitted, and the flange 53 may be merely a protrusion and may not be annular.

Further, in the shock absorber A according to the present embodiment, tapered surfaces 7b and 7c whose diameters increase toward one end or the other end of the guide cylinder 7 are formed on the inner circumferences of both ends of the guide cylinder 7 in the axial direction. , Seal rings 72 and 73 are housed between the tapered surfaces 7b and 7c and the cylinder 1, respectively. As a result, when the seal rings 72 and 73 are compressed, they are pressed against the cylinder 1 by the tapered surfaces 7b and 7c, so that the sealing property can be improved. However, if the sealing property can be ensured, the shape of the sealing surface sealed by the sealing rings 72 and 73 is not limited to the taper and can be changed as appropriate.

Further, the shock absorber A according to the present embodiment includes a cap member 5 that closes the upper end (one end in the axial direction) of the cylinder 1. Then, the cap member 5 is arranged on the outer circumference of the annular screw portion 50 screwed to the inner circumference of the cylinder 1, the lid portion 51 that closes the upper end (one end) of the screw portion 50, and the lid portion 51. A flange 53 having an outer diameter larger than the outer diameter of the threaded portion 50 is provided, and this flange 53 functions as a flange of the fixture J, and the seal ring 72 is compressed between the flange 53 and the guide cylinder 7. Will be done.

As a result, the seal ring 72 can seal between the cylinder 1 and the guide cylinder 7, and can also seal between the cylinder 1 and the cap member 5. Therefore, according to the above configuration, the number of seal rings can be reduced even when the cylinder 1 and the cap member 5 are individually formed and then integrated by screwing or the like. However, it goes without saying that the cylinder and the guide cylinder and the cylinder and the cap member may be sealed with separate seal rings.

Further, in the shock absorber A according to the present embodiment, the cap member 5 has a tubular portion 54 extending in the axial direction from the lower end (other end) of the screw portion 50. A rib 54a that abuts on the inner circumference of the cylinder 1 is formed on the outer circumference of the cylinder portion 54. As a result, the cylinder 1 is reinforced by the cylinder portion 54, so that a structure advantageous for bending and prying load can be obtained.

Further, the shock absorber A according to the present embodiment is provided on the upper side (cap member side) of the piston 2 and includes a lock piece 33 that separates the inside and outside of the cylinder portion 54 when inserted into the cylinder portion 54. There is. As a result, the tubular portion 54 and the lock piece 33 form a hydraulic lock mechanism, and the impact at the time of maximum contraction of the shock absorber A can be alleviated.

However, the lock piece 33 may be omitted. Further, in such a case, when it is not necessary to reinforce the cylinder 1, the cylinder portion 54 may be omitted. When the cylinder portion 54 is omitted, the cylinder 1 and the cap member 5 may be integrally molded. Further, the flange 53 may be integrally molded with the cylinder 1, is separate from the cylinder 1 and the cap member 5, and may be mounted on the outer periphery of the cylinder 1 or the cap member 5 by a snap ring or the like.

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

A ... shock absorber, J ... fixture, 1 ... cylinder, 2 ... piston, 3 ... piston rod, 4 ... tank, 5 ... cap member, 7 ... Guide cylinder, 7b, 7c ... Tapered surface, 8 ... Washer, 9 ... Screw ring, 33 ... Lock piece, 50 ... Screw part, 51 ... Lid part, 53 ... Flange , 54 ... Cylinder, 54a ... Rib, 72, 73 ... Seal ring

Claims (7)

Cylinder and
A piston that is movably inserted into the cylinder in the axial direction,
A piston rod that is connected to the piston and one end of which protrudes out of the cylinder.
A tank that is rotatably mounted on the outside of the cylinder in the circumferential direction of the cylinder and whose inside is communicated with the inside of the cylinder.
A shock absorber comprising a fixture for fixing the tank at an arbitrary position in the circumferential direction of the outer circumference of the cylinder. A guide cylinder that is rotatably mounted in the circumferential direction is provided on the outer circumference of the cylinder.
The tank is provided integrally with the guide cylinder, and is provided.
The fixture has a screw ring screwed onto the outer circumference of the cylinder and a flange protruding radially outward from the outer circumference of the cylinder, and the guide cylinder is axially mounted on both sides of the screw ring and the flange. The shock absorber according to claim 1, wherein the guide cylinder is sandwiched to prevent the guide cylinder from rotating in the circumferential direction with respect to the cylinder. Seal rings provided on the outer circumference of the cylinder at both ends in the axial direction of the guide cylinder, and
A washer, which is the outer circumference of the cylinder and is mounted between the guide cylinder and the screw ring in a state of being stopped by the guide cylinder, is provided.
When the screw ring is tightened, one of the seal rings is compressed between the guide cylinder and the flange, and the other seal ring is compressed between the guide cylinder and the washer. The shock absorber according to claim 2. Tapered surfaces that increase in diameter toward one end or the other end of the guide cylinder are formed on the inner circumferences of both ends in the axial direction of the guide cylinder.
The shock absorber according to claim 3, wherein the seal ring is housed between the tapered surface and the cylinder. A cap member for closing one end of the cylinder in the axial direction is provided.
The cap member is arranged on an annular screw portion screwed to the inner circumference of the cylinder, a lid portion that closes one end of the screw portion, and an outer circumference of the lid portion, and has an outer diameter outside the screw portion. The shock absorber according to any one of claims 2 to 4, wherein the shock absorber has a flange larger than the diameter. The cap member has a tubular portion extending axially from the other end of the threaded portion.
The shock absorber according to claim 5, wherein a rib that contacts the inner circumference of the cylinder is formed on the outer periphery of the cylinder portion. The shock absorber according to claim 6, further comprising a lock piece that is arranged on the cap member side of the piston and that separates the inside and outside of the cylinder when inserted into the cylinder.

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