JP2014029175A - Fluid pressure shock absorber - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fluid pressure shock absorber capable of restraining increase of costs.SOLUTION: A rebound stopper mechanism 70 comprises: a base spring receiver 71 integrally movably provided to a piston rod 15; a movable spring receiver 72 that is slidably provided to the piston rod 15 and can contact a stopper 21 fixed to a cylinder 19; and spring means 73 interposed between the base spring receiver 71 and the movable spring receiver 72. A base spring receiver extension part 76 and a movable spring receiver extension part 81 extending in an axial direction between the spring means 73 and the piston rod 15 and restraining contact of the spring means 73 to the piston rod 15 are provided to the base spring receiver 71 and the movable spring receiver 72. While the spring means 73 is most shrunk, the base spring receiver extension part 76 and the movable spring receiver extension part 81 have such length that they are not in contact with each other.

Description

  The present invention relates to a fluid pressure shock absorber.

  There is a mechanism for limiting the extension of the piston rod from the cylinder (for example, see Patent Document 1).

JP 2004-124993 A

  The mechanism is costly.

  Therefore, an object of the present invention is to provide a fluid pressure shock absorber that can suppress an increase in cost.

  In order to achieve the above object, the present invention provides a base spring receiver and a movable spring receiver that extend in the axial direction between a spring means and a piston rod and restrict the contact of the spring means to the piston rod. An extension portion and a movable spring receiving extension portion are provided so that the base spring receiving extension portion and the movable spring receiving extension portion are not in contact with each other when the spring means is contracted most.

  According to the present invention, an increase in cost can be suppressed.

It is sectional drawing which shows the fluid pressure buffer which concerns on one Embodiment of this invention.

  A fluid pressure shock absorber according to an embodiment of the present invention will be described below with reference to the drawings.

  A fluid pressure shock absorber 11 according to this embodiment shown in FIG. 1 is a hydraulic shock absorber in which oil is used as a working fluid, and is used in a suspension device of a vehicle such as an automobile. The fluid pressure shock absorber 11 includes an inner cylinder 12, an outer cylinder 14 having a larger diameter than the inner cylinder 12 and coaxially disposed so as to form a reservoir chamber 13 between the inner cylinder 12 and the center of the inner cylinder 12. A piston rod 15 disposed on the axis and having one end in the axial direction inserted into the inner cylinder 12 and the other end in the axial direction extending from the inner cylinder 12 and the outer cylinder 14 to the outside, and one end of the piston rod 15 The piston 18 is connected and slidably fitted in the inner cylinder 12 and partitions the inner cylinder 12 into two chambers 16 and 17. That is, the fluid pressure shock absorber 11 is a double cylinder type in which the cylinder 19 includes the inner cylinder 12 and the outer cylinder 14. The inner cylinder 12 is filled with an oil liquid as a working fluid, and the reservoir chamber 13 between the inner cylinder 12 and the outer cylinder 14 is filled with an oil liquid and a high-pressure gas as the working fluid. Will be.

  The fluid pressure shock absorber 11 includes a rod guide 21 disposed at an end position on the protruding side of the piston rod 15 in the axial direction of the cylinder 19 and an oil disposed further outside the rod guide 21 in the axial direction of the cylinder 19. It has a seal 22 and a base valve 23 disposed at the end of the cylinder 19 opposite to the rod guide 21 and the oil seal 22 in the axial direction. Both the rod guide 21 and the oil seal 22 have an annular shape, and the piston rod 15 is slidably inserted into the inside thereof. The rod guide 21 supports the piston rod 15 so as to be movable in the axial direction while restricting its radial movement, and guides the movement of the piston rod 15. The oil seal 22 is in sliding contact with the piston rod 15 moving in the axial direction at the inner peripheral portion thereof, and restricts leakage of the oil liquid in the inner cylinder 12 and the high-pressure gas and oil liquid in the reservoir chamber 13 to the outside. To do. In the present embodiment, the oil liquid and the high-pressure gas as the working fluid are enclosed in the reservoir chamber 13, but not limited to the high-pressure gas, air may be enclosed.

  The outer cylinder 14 of the cylinder 19 is made of metal, and has a cylindrical body portion 25, a bottom portion 26 that closes one end side of the body portion 25 opposite to the protruding side of the piston rod 15, and a piston in the body portion 25. It has a substantially bottomed cylindrical shape having a locking portion 28 protruding radially inward from the position of the opening 27 on the protruding side of the rod 15.

  The inner cylinder 12 of the cylinder 19 is made of metal and has a cylindrical shape, and one end side in the axial direction is supported in a fitted state with the base body 30 of the base valve 23 disposed inside the bottom portion 26 of the outer cylinder 14. The other end side in the axial direction is supported in a fitted state by a rod guide 21 that is fitted inside the opening 27 of the outer cylinder 14.

  The base body 30 of the base valve 23 is made of metal, and the base body 30 has an oil passage 31 capable of communicating the chamber 17 in the inner cylinder 12 and the reservoir chamber 13 between the outer cylinder 14 and the inner cylinder 12. , 32 are formed. Further, a disc valve 33 as a compression side damping valve capable of opening and closing the inner oil passage 31 is disposed on the bottom portion 26 side in the base body 30 and a disk valve as a check valve capable of opening and closing the outer oil passage 32. 34 is arranged on the side opposite to the bottom 26. The disc valves 33 and 34 are attached to the base body 30 by a head portion 35a at one end of a rivet 35 and a crimping portion 35b at the other end of the rivet 35 inserted into the base body 30 from the bottom 26 side.

  The disk valve 33 generates a damping force by allowing the oil liquid to flow from the chamber 17 to the reservoir chamber 13 via a passage hole (not shown) of the disk valve 34 and the oil passage 31, while the oil liquid in the reverse direction is generated. On the contrary, the disc valve 34 allows the flow of oil from the reservoir chamber 13 to the chamber 17 through the oil passage 32 without resistance, while allowing the flow of oil in the reverse direction. regulate. That is, the disc valve 33 opens the oil passage 31 when the piston rod 15 moves to the contraction side, the piston 18 moves to the chamber 17 side, and the pressure in the chamber 17 rises, and a damping force is generated at that time. It is a damping valve. The disk valve 34 opens the oil passage 32 when the piston rod 15 moves to the extension side, the piston 18 moves to the chamber 16 side, and the pressure in the chamber 17 decreases. This is a suction valve that allows oil to flow without substantially generating a damping force in the chamber 17.

  The piston rod 15 is made of metal, and has a main shaft portion 37 having a substantially constant diameter, and an attachment shaft portion 38 having a diameter smaller than that of the main shaft portion 37 at an end portion to be inserted into the inner cylinder 12. . A nut 39 is screwed to the mounting shaft portion 38, and the piston 18 and the disk valves 41 and 42 on both sides thereof are attached to the piston rod 15 by the nut 39. The piston rod 15 moves integrally with the piston 18.

  The piston 18 is formed with an oil passage 44 and an oil passage 45 capable of communicating between the chamber 17 on the bottom 26 side of the inner cylinder 12 and the chamber 16 on the opposite side of the bottom 26. The piston 18 is provided with the above-described disk valve 41, which is a compression-side damping valve capable of opening and closing the outer oil passage 44, on the side opposite to the bottom portion 26, and extends so as to open and close the inner oil passage 45. The disk valve 42 described above as a side damping valve is disposed on the bottom 26 side.

  The disc valve 41 allows the flow of the oil liquid from the chamber 17 to the chamber 16 side, while restricting the flow of the oil liquid in the reverse direction. On the contrary, the disc valve 42 moves from the chamber 16 side to the chamber 17. While allowing the flow of oil, the flow of oil in the opposite direction is restricted. That is, the disc valve 41 opens the oil passage 44 when the piston rod 15 moves to the contraction side, the piston 18 moves to the chamber 17 side, and the pressure in the chamber 17 rises, and a damping force is generated at that time. It is a damping valve. The disc valve 42 opens the oil passage 45 when the piston rod 15 moves to the extension side and the piston 18 moves to the chamber 16 side and the pressure in the chamber 16 rises, and a damping force is generated at that time. It is a damping valve.

  When the piston rod 15 moves to the extension side and the amount of protrusion from the cylinder 19 increases, the corresponding amount of oil liquid opens the disc valve 34 of the base valve 23 from the reservoir chamber 13 through the oil passage 32 and the chamber 17. On the contrary, when the piston rod 15 moves to the contraction side and the amount of insertion into the cylinder 19 increases, the corresponding amount of oil liquid opens the disc valve 33 from the chamber 17 and opens the reservoir via the oil passage 31. It will flow into the chamber 13.

  The rod guide 21 includes a metal rod guide main body 50 having a substantially stepped cylindrical shape, and a cylindrical collar 51 fitted and fixed to the inner peripheral portion of the rod guide main body 50. The collar 51 is formed by coating a metal cylinder such as SPCC material or SPCE material with a fluororesin-impregnated bronze.

  The rod guide body 50 has an outer shape in which a large-diameter outer diameter portion 54 is formed on one side in the axial direction, and a small-diameter outer diameter portion 55 having a smaller diameter than the large-diameter outer diameter portion 54 is formed on the other side in the axial direction. The large diameter outer diameter portion 54 is fitted to the inner peripheral portion of the body portion 25 of the outer cylinder 14, and the small diameter outer diameter portion 55 is fitted to the inner peripheral portion of the inner cylinder 12. In the center of the rod guide body 50 in the radial direction, a large-diameter hole portion 56 is provided on the large-diameter outer diameter portion 54 side in the axial direction, and a small-diameter smaller diameter than the large-diameter hole portion 56 is provided on the small-diameter outer diameter portion 55 side in the axial direction. Each hole 57 is formed.

  The rod guide main body 50 is formed with an annular convex portion 59 projecting in the axial direction at an end portion on the large-diameter outer diameter portion 54 side in the axial direction. A communication hole 61 penetrating along the direction is formed. The communication hole 61 communicates with the reservoir chamber 13 between the outer cylinder 14 and the inner cylinder 12. The collar 51 is fitted in the small diameter hole portion 57 of the rod guide body 50, and the rod guide 21 is inserted into the collar 51 so that the piston rod 15 is in sliding contact with the outer peripheral portion of the main shaft portion 37. The

  The oil seal 22 is formed by bonding rubber to a metal core, and is disposed at one end of the cylinder 19 in the axial direction, and is in pressure contact with the outer peripheral portion of the main shaft portion 37 of the piston rod 15 at the inner peripheral portion thereof. Thus, the leakage of oil or the like leaking from the gap between the rod guide 21 and the main shaft portion 37 of the piston rod 15 is restricted. The oil seal 22 is in contact with the annular convex portion 59 of the rod guide 21 on one axial side of the outer peripheral portion, and is in contact with the locking portion 28 of the outer cylinder 14 on the other side in the axial direction.

  A metal fixing member 65 is fixed to the main shaft portion 37 of the piston rod 15. The fixing member 65 includes a perforated disk-like stopper portion 66 and an engaging portion 67 extending from the inner peripheral side of the stopper portion 66 to one side in the axial direction. The engaging portion 67 has a diameter. It is crimped inward in the direction and fixed to the piston rod 15. That is, the fixing member 65 is fitted to the outer peripheral portion of the main shaft portion 37 of the piston rod 15 at the inner peripheral portion in a posture in which the engaging portion 67 before caulking is directed toward the mounting shaft portion 38 in the axial direction. Thus, in this state, the engaging portion 67 is crimped and engaged with the fixing groove 68 formed on the outer peripheral portion of the main shaft portion 37, whereby the main shaft portion 37 is fixed at a predetermined position in the axial direction. The outer diameter of the stopper portion 66, which is the maximum outer diameter of the fixing member 65, is smaller than the inner diameter of the inner cylinder 12.

  The piston rod 15 is provided with a rebound stopper mechanism 70 that restricts the extension of the piston rod 15 at a portion located in the inner cylinder 12 of the main shaft portion 37, in other words, between the piston 18 and the rod guide 21. It has been. The rebound stopper mechanism 70 includes a resin base spring receiver 71 provided on the rod guide 21 side of the fixed member 65, a resin movable spring receiver 72 provided on the rod guide 21 side of the base spring receiver 71, and a base spring receiver 71. A metal rebound spring (spring means) 73 interposed between the movable spring receiver 72 is provided. The base spring receiver 71 and the movable spring receiver 72 are preferably made of the same material, for example, a polyamide synthetic fiber that hardly deteriorates in hydraulic oil. By using a resin material, it is possible to suppress the generation of sound when the piston rod 15 is in sliding contact.

  The base spring receiver 71 has an annular contact portion 75, an outer diameter smaller than the outer diameter of the contact portion 75, and the same inner diameter as the inner diameter of the contact portion. A cylindrical extension portion (base spring receiving extension portion) 76 that extends, and a locking projection 77 that protrudes radially outward from an intermediate position of the extension portion 76 on the axial contact portion 75 side are provided. Yes. The base spring receiver 71 is fitted to the outer peripheral portion of the main shaft portion 37 of the piston rod 15 at the inner peripheral portion in a posture in which the abutting portion 75 faces the mounting shaft portion 38 side in the axial direction. The piston rod 15 can slide.

  The base spring receiver 71 moves further toward the mounting shaft 38 with respect to the piston rod 15 by contacting the stopper 66 of the fixing member 65 at the end opposite to the extension 76 of the contact portion 75. In this state, the piston rod 15 moves integrally. That is, the base spring receiver 71 is provided so as to be movable integrally with the piston rod 15. The outer diameter of the contact portion 75 that is the maximum outer diameter of the base spring receiver 71 is smaller than the inner diameter of the inner cylinder 12. Therefore, the base spring receiver 71 is assembled so as to be movable with respect to the piston rod 15 in a state where it is not in contact with the stopper portion 66 of the fixing member 65, that is, not fixed to the piston rod 15. However, when the base spring receiver 71 is in contact with the stopper portion 66, the base spring receiver 71 is in a state where it can move integrally with the piston rod 15 thereafter. In this embodiment, the base spring receiver 71 is arranged in a non-fixed state with respect to the piston rod 15. However, for example, the base spring receiver 71 and the fixing member 65 are integrally fixed to the piston rod 15. You may make it provide. In short, the base spring receiver 71 may be in a state that can be fixed to the piston rod 15 when the rebound spring 73 contracts.

  The movable spring receiver 72 has an annular contact portion 80, an outer diameter smaller than the outer diameter of the contact portion 80, and the same inner diameter as the inner diameter of the contact portion 80. A cylindrical extension (movable spring receiving extension) 81 extending to the side, and a locking projection 82 projecting radially outward from an intermediate position of the extension 81 on the axial contact portion 80 side. Have. The movable spring receiver 72 is fitted to the outer peripheral portion of the main shaft portion 37 of the piston rod 15 at the inner peripheral portion in a posture in which the extension portion 81 faces the mounting shaft portion 38 side in the axial direction. The piston rod 15 can slide.

  The movable spring receiver 72 can abut on the rod guide 21 at the end opposite to the extension 81 of the abutting portion 80, and further abut against the cylinder 19 by abutting on the rod guide 21. Movement to the 21 side is restricted. Therefore, in other words, the rod guide 21 fixed to the cylinder 19 comes into contact with the movable spring receiver 72 and serves as a stopper for restricting the axial movement thereof. The outer diameter of the contact portion 80, which is the maximum outer diameter of the movable spring receiver 72, is smaller than the inner diameter of the inner cylinder 12. In the present embodiment, the base spring receiver 71 and the movable spring receiver 72 are common parts of the same shape and the same material.

  The rebound spring 73 contracts in the axial direction to generate an elastic force, and is a coil spring in which a linear member having a circular cross section and a constant outer diameter is wound so as to be a spiral having a constant outer diameter and a constant inner diameter in a natural state. It is made up of. The inner diameter of the rebound spring 73 is substantially the same as the outer diameter of the extension portion 76 of the base spring receiver 71 and the outer diameter of the extension portion 81 of the movable spring receiver 72, and the outer diameter of the locking projection 77 of the base spring receiver 71 and the movable spring. The diameter is smaller than the outer diameter of the locking projection 82 of the receiver 72.

  In the rebound spring 73, the extension portion 76 and the locking convex portion 77 of the base spring support 71 are press-fitted into one end portion in the axial direction until the contact portion 75 is contacted. A receiver 71 is attached. Further, the rebound spring 73 is press-fitted to the other end portion in the axial direction until the extension portion 81 and the locking projection portion 82 of the movable spring receiver 72 are brought into contact with the contact portion 80. In this way, the movable spring receiver 72 is attached.

  The rebound spring 73, the base spring receiver 71, and the movable spring receiver 72 are integrated in advance as described above and assembled as the rebound stopper mechanism 70, and the piston rod 15 is formed at the inner peripheral portions of the base spring receiver 71 and the movable spring receiver 72. The main shaft portion 37 is fitted. In this state, the extension portion 76 of the base spring receiver 71 and the extension portion 81 of the movable spring receiver 72 both extend in the axial direction of the piston rod 15 between the rebound spring 73 and the main shaft portion 37 of the piston rod 15. .

  Here, when the rebound spring 73 is in the most contracted state in the axial direction as shown in FIG. 1, the one-turn portions of the linear members are in close contact with each other without any gap between them. If the relative rotation occurs between the base spring receiver 71 and the movable spring receiver 72 and the relative rotation occurs between one end and the other end of the rebound spring 73 (that is, the rebound spring 73 is twisted) in this tight contact state between the lines. There may be a line-to-line shift in which each winding portion of the member does not shift sequentially in the circumferential direction. When such a line-to-line deviation occurs, the linear member may be locally reduced inward in the radial direction of the rebound spring 73, and the other part may be increased in diameter accordingly.

  Even if the rebound spring 73 is in a close contact state between the base spring receiver 71 and the movable spring receiver 72 and relative rotation occurs between one end and the other end of the rebound spring 73, the extension 76 and the extension 81 are rebound. The deformation of the spring 73 toward the radially inner side is restricted, and as a result, the deformation toward the radially outer side is also restricted. As a result, each winding portion of the linear member of the rebound spring 73 is sequentially displaced substantially in the circumferential direction, thereby restricting the occurrence of line-to-line deviation. That is, the extension part 76 of the base spring receiver 71 and the extension part 81 of the movable spring receiver 72 regulate the contact of the rebound spring 73 to the piston rod 15 and the contact to the inner cylinder 12.

  Thus, while restricting the contact of the rebound spring 73 in the most contracted state to the piston rod 15 and the inner cylinder 12, the extension portion 76 of the base spring receiver 71 and the extension portion 81 of the movable spring receiver 72 are mutually connected. The length is set so as not to contact. That is, the length is such that the extension portion 76 of the base spring receiver 71 and the extension portion 81 of the movable spring receiver 72 do not come into contact with each other when the rebound spring 73 is most contracted. Here, the minimum gap between the extension portion 76 of the base spring receiver 71 and the extension portion 81 of the movable spring receiver 72 when the rebound spring 73 is most contracted is equal to or smaller than the wire diameter of the rebound spring 73, that is, the rebound spring 73. Is set to be equal to or smaller than the outer diameter of the linear member constituting the. In other words, in a state where the rebound spring 73 as the spring means is most contracted, a gap generated between the base spring receiving extension portion and the movable spring receiving extension portion is smaller than the wire diameter of the rebound spring 73 as the spring means.

  In the above-mentioned Patent Document 1, since a rebound stopper is provided between the rebound spring of the piston rod and between the one spring receiver and the other spring receiver, the assembly is complicated and the manufacturing cost is low. It will increase. On the other hand, in the fluid pressure shock absorber 11 of this embodiment, as described above, the rebound stopper mechanism 70 including the rebound spring 73, the base spring receiver 71, and the movable spring receiver 72 is assembled in advance, and the rebound stopper mechanism 70 is assembled. Can be assembled by being fitted to the piston rod 15 in a state in which the fixing member 65 is fixed in advance, so that the assembly is easy and an increase in cost can be suppressed.

  Further, in the above-described Patent Document 1, since the rebound spring is restricted from being brought into a close contact state between the lines, the line displacement that may occur in the fluid pressure shock absorber 11 of the present embodiment does not occur. . On the other hand, in the fluid pressure shock absorber 11 of the present embodiment, the extension 76 of the base spring receiver 71 and the extension 81 of the movable spring receiver 72 cause a line-to-line shift caused by the rebound spring 73 being in a line-to-line contact state. And the contact of the rebound spring 73 with the piston rod 15 and the contact with the inner cylinder 12 are restricted. Thereby, generation | occurrence | production of the noise resulting from the rebound spring 73 contact | abutting to the piston rod 15 or the inner cylinder 12 can be controlled.

  More specifically, for example, when the vehicle body is jacked up with the above-described fluid pressure shock absorber 11 mounted on an automobile suspension device, the piston rod 15 extends and is pushed against the fixing member 65 fixed to the piston rod 15. Then, the rebound stopper mechanism 70 moves to the rod guide 21 side together with the piston rod 15. When the movable spring receiver 72 comes into contact with the rod guide 21, the movement of the movable spring receiver 72 is restricted by the rod guide 21, and the movable spring receiver 72 moves relative to the piston rod 15. On the other hand, the base spring receiver 71 that contacts the fixing member 65 fixed to the piston rod 15 moves integrally with the fixing member 65 and the piston rod 15, so that the distance between the movable spring receiver 72 and the base spring receiver 71 is reduced. The rebound spring 73 interposed therebetween contracts to generate an elastic force. As a result, the moving speed of the piston rod 15 with respect to the cylinder 19 is greatly decelerated, and finally stops when the rebound spring 73 is brought into the line-to-line contact state.

  When a steering operation such as turning the steering wheel is performed in the fully extended state of the fluid pressure shock absorber 11, a load due to a relative steering input is input between the piston rod 15 and the cylinder 19. . Then, between the base spring receiver 71 that is in close contact with the fixed member 65 and rotates with the piston rod 15 and the fixed member 65, and the movable spring receiver 72 that is in close contact with the rod guide 21 and rotates with the cylinder 19 and the rod guide 21. Relative rotation occurs, and as a result, relative rotation also occurs at one end side and the other end side of the rebound spring 73 press-fitted at both ends thereof. Even in such a situation, the extension portion 76 of the base spring receiver 71 and the extension portion 81 of the movable spring receiver 72 regulate the contact of the rebound spring 73 to the piston rod 15 and the contact to the inner cylinder 12. . Thereby, generation | occurrence | production of the noise resulting from the rebound spring 73 contact | abutting to the piston rod 15 or the inner cylinder 12 can be controlled.

  Further, in Patent Document 1 described above, the spring receivers on both sides are brought into contact with each other so as to restrict the rebound springs from coming into close contact with each other. The receivers come into contact with each other and generate abnormal noise. On the other hand, in the fluid pressure shock absorber 11 of the present embodiment, since the extension portion 76 of the base spring receiver 71 and the extension portion 81 of the movable spring receiver 72 do not come into contact with each other, it is possible to prevent the generation of noise during contact. In addition, a cushioning material or the like for suppressing the occurrence of this abnormal noise is unnecessary, and an increase in the number of parts and an increase in cost can be suppressed.

  Furthermore, if a square spring in which a linear member having a rectangular cross section is spirally wound is used, it is possible to suppress a gap between lines against twisting in a close contact state between the lines, but the square spring is expensive. It will increase the cost. On the other hand, in the fluid pressure shock absorber 11 of the present embodiment, the extension portion 76 may be formed on the base spring receiver 71 and the extension portion 81 may be formed on the movable spring receiver 72, so the rebound spring 73 may be a round spring. Cost increase can be suppressed.

  In the above embodiment, the double cylinder type hydraulic shock absorber is shown as the fluid pressure shock absorber 11, but the present invention can also be applied to a fluid pressure shock absorber such as a single cylinder type hydraulic shock absorber or a hydraulic active suspension. Moreover, it is applicable also to what uses gas as a working fluid.

  In the embodiment described above, a cylinder in which a working fluid is sealed, a piston that is slidably fitted in the cylinder, one end side is connected to the piston, and the other end side is extended to the outside of the cylinder. In the fluid pressure shock absorber provided with a piston rod and a rebound stopper mechanism for restricting the extension of the piston rod, the rebound stopper mechanism is provided with a base spring support provided so as to be integrally movable with the piston rod, and the piston rod. A movable spring receiver that is slidably provided and is capable of contacting a stopper fixed to the cylinder; and a spring means interposed between the base spring receiver and the movable spring receiver, the base spring receiver and In the movable spring receiver, the spring means to the piston rod extends in an axial direction between the spring means and the piston rod. A base spring receiving extension and a movable spring receiving extension for restricting the contact are provided, and the base spring receiving extension and the movable spring receiving extension are not in contact with each other when the spring means is in its most contracted state. It is characterized by being. As a result, assembly is facilitated and an increase in cost can be suppressed. In addition, since the base spring receiving extension portion and the movable spring receiving extension portion do not come into contact with each other, it is possible to prevent the generation of noise during contact.

11 Fluid Pressure Shock Absorber 15 Piston Rod 18 Piston 19 Cylinder 21 Rod Guide (Stopper)
70 Rebound stopper mechanism 71 Base spring receiver 72 Movable spring receiver 73 Rebound spring (spring means)
76 Extension (base spring support extension)
81 Extension (movable spring support extension)

Claims (2)

A cylinder filled with a working fluid;
A piston slidably fitted in the cylinder;
A piston rod having one end connected to the piston and the other end extending to the outside of the cylinder;
A rebound stopper mechanism for limiting the extension of the piston rod;
In a fluid pressure shock absorber comprising:
The rebound stopper mechanism includes a base spring receiver provided so as to be fixed to the piston rod side, a movable spring receiver slidably provided on the piston rod and capable of contacting a stopper fixed to the cylinder, and the base spring. Spring means interposed between the receiver and the movable spring receiver,
The base spring receiver and the movable spring receiver include a base spring receiving extension and a movable spring receiving extension that extend in the axial direction between the spring means and the piston rod to restrict the contact of the spring means with the piston rod. The fluid pressure shock absorber is characterized in that the base spring receiving extension portion and the movable spring receiving extension portion do not come into contact with each other when the spring means is most contracted.   2. The fluid pressure buffer according to claim 1, wherein a gap generated between the base spring receiving extension and the movable spring receiving extension is smaller than a wire diameter of the spring means in a state where the spring means is most contracted. vessel.

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