JP4839332B2 - Buffer valve structure - Google Patents

Description

  The present invention relates to an improved valve structure of a shock absorber.

  Conventionally, in this kind of shock absorber valve structure, for example, it is embodied in the piston portion of the shock absorber built in the front fork of the two-wheeled vehicle, and the outlet end of the port provided in the piston is an annular leaf valve. The leaf valve is biased toward the piston side by a coil spring (see, for example, Patent Document 1).

  Specifically, in the valve structure of the shock absorber described above, a leaf valve is slidably mounted on the outer periphery of a piston holder that passes through the axial center portion of the piston and holds the piston, and the leaf valve is axially moved with respect to the piston. When the pressure of the hydraulic oil acting on the front side of the leaf valve increases, the coil spring is compressed and the leaf valve moves backward from the piston to open the port greatly.

By adopting such a configuration, the port in a region where the piston speed is relatively high compared to a valve structure in which the port is opened by fixing and supporting the inner periphery of the leaf valve and bending the outer periphery of the leaf valve. Can be greatly opened, and the damping force during the compression stroke can be prevented from becoming excessive, and the riding comfort in the vehicle can be improved.
Japanese Patent Laying-Open No. 2003-247484 (FIG. 1)

  However, in the proposed valve structure as described above, although it is a useful technique in terms of improving riding comfort in a vehicle, it may be pointed out that there are the following problems.

  The conventional valve structure employs a configuration in which the leaf valve is energized with a coil spring, making it difficult to produce a coil spring with a uniform natural length and spring constant, and generating and damping a shock absorber that embodies the valve structure. There is a risk that the force varies from product to product.

  In addition, when the valve structure described above is used for the piston part of the shock absorber built in the front fork, it is necessary to avoid increasing the size of the piston part from the viewpoint of mounting in a narrow front fork and securing the stroke length of the shock absorber. Under the conditions that the coil spring radial size and compression length are significantly limited, the coil spring wire diameter cannot be increased, and the leaf valve may not be provided with sufficient urging force. .

  For example, when the compression speed is in the low speed range, even if an attempt is made to generate a damping force according to the piston speed by bending only the outer periphery without lifting the leaf valve, the compression speed is actually in the low speed range. However, the coil spring is compressed, the leaf valve lifts from the piston, and the port is greatly opened, so that the compression side damping force in the low speed region is insufficient unlike the intended purpose of the designer.

  Also, if the vibration direction of the shock absorber reverses from the compressed state to the extension direction from the compressed state of the coil spring, the port must be closed quickly with a leaf valve, but if the biasing force of the coil spring is insufficient, There is a delay in the closing operation of the leaf valve, the pressure side chamber and the extension side chamber are maintained in communication with each other at the port, and the damping force immediately after the shock absorber is switched from the compression stroke to the extension stroke is insufficient. Things will also happen.

  The present invention was devised in order to improve the above-mentioned problems, and the object of the present invention is to provide a shock absorber valve structure capable of generating a stable damping force and generating a sufficient damping force in a low speed range. Is to provide.

  In order to solve the above-mentioned object, the valve structure of the shock absorber in the problem solving means of the present invention is slidably inserted into the cylinder to form the pressure side chamber and the extension side chamber in the cylinder, and at the same time the pressure side chamber and the extension side chamber. A piston with a port communicating with the side chamber, an annular leaf valve that is axially movable on the extension side chamber side of the piston and opens and closes the outlet end of the port, and urges the leaf valve toward the piston side And a biasing means having a pair of leaf springs and biasing the leaf valve by the elastic force of these leaf springs.

  In the valve structure of the shock absorber according to the present invention, the leaf valve that opens and closes the port is urged by a leaf spring having a small individual difference in the spring constant, so a coil spring is used as the urging means. Compared with the conventional valve structure, the variation of the generated damping force in the shock absorber for each product can be suppressed.

  Also, even if the number of laminated annular plates constituting the leaf spring is increased or the leaf spring is thickened in order to set a large spring constant in the leaf spring, it does not become long in the axial direction. Therefore, since enlargement of the piston portion can be avoided, a sufficient urging force can be applied to the leaf valve without sacrificing the stroke length of the shock absorber.

  Therefore, by setting the initial load by the leaf spring as appropriate, when the compression speed is in the low speed range, the leaf valve is not lifted and only the outer periphery of the leaf valve is deflected to reduce the damping force according to the piston speed. And the damping force on the compression side in the low speed range can be sufficiently generated in the shock absorber.

  Further, since the leaf valve can be sufficiently biased by the leaf spring, when the vibration direction of the shock absorber is reversed from the compression direction to the extension direction, the leaf valve is quickly returned to the position where the port is closed. Therefore, the damping force immediately after the shock absorber is switched from the compression stroke to the expansion stroke does not become insufficient.

  Therefore, according to the valve structure of the shock absorber of the present invention, a stable damping force can be generated in the shock absorber, and a sufficient damping force can be generated even when the expansion / contraction speed of the shock absorber is in a low speed range. Can do it.

  The valve structure of the present invention will be described below with reference to the drawings. FIG. 1 is a longitudinal sectional view of a piston portion in which a valve structure of a shock absorber according to an embodiment is embodied. FIG. 2 is a diagram in which a shock absorber in which the valve structure of the shock absorber in one embodiment is embodied is applied to a front fork.

  As shown in FIG. 1, the valve structure of the shock absorber in one embodiment is embodied as a damping valve on the pressure side of the piston portion of the shock absorber D, and is slidably inserted into the cylinder 1. A compression side chamber R1 and an expansion side chamber R2 are formed therein, and a piston 2 having a pressure side port 2a serving as a port for communicating the compression side chamber R1 and the expansion side chamber R2, and the piston 2 is movable in the axial direction toward the expansion side chamber. An annular leaf valve 3 that is stacked and opens and closes the outlet end of the port 2a, and a pair of leaf springs 4 and 5 as urging means that urges the leaf valve 3 toward the piston 2 side. Yes.

  On the other hand, the shock absorber D in which the valve structure is embodied is applied to a front fork F as shown in FIG. 2, specifically, a cylinder 1 and a slidably inserted into the cylinder 1. A piston 2 that forms a compression side chamber R1 and an expansion side chamber R2 in the cylinder 1, a reservoir cylinder 10 that is connected to the upper end of the cylinder 1 in FIG. A piston rod 11 that is inserted and connected to the piston 2 is provided, and the cylinder 1 is filled with a fluid, specifically, hydraulic oil.

  The piston 2 has an annular shape and includes an expansion side port 2b in addition to the compression side port 2a described above. The compression side chamber R1 and the expansion side chamber R2 are communicated with each other by the compression side and the expansion side ports 2a and 2b. .

  The port 2a is opened and closed by a leaf valve 3 stacked on the lower end in FIG. 1 of the piston 2, and the leaf valve 3 prevents the flow of hydraulic oil from the extension side chamber R2 toward the compression side chamber R1, Resistance is applied to the flow of hydraulic oil from the compression side chamber R1 to the extension side chamber R2.

  On the other hand, the port 2b is opened and closed by a leaf valve 12 stacked on the upper end of the piston 2 in FIG. 1, and the leaf valve 12 prevents the flow of hydraulic oil from the compression side chamber R1 toward the extension side chamber R2. At the same time, resistance is given to the flow of liquid from the extension side chamber R2 toward the pressure chamber R1.

  In the reservoir R, an air chamber 14 and an oil chamber 15 are partitioned by a free piston 13, and the oil chamber 15 is filled with hydraulic oil in the same manner as the cylinder 1. The free piston 13 is urged downward in FIG. 2 by a spring 17 interposed between the free piston 13 and a sealing member 16 that closes the upper end of the reservoir cylinder 10. Is pressurized.

  Further, the shock absorber D includes a partition member 18 that partitions the pressure side chamber R1 formed in the cylinder 1 and the oil chamber 15 provided in the reservoir R, and a port 18a provided in the partition member 18, The pressure side chamber R1 and the oil chamber 15 are communicated with each other through 18b.

  One port 18a is opened and closed by a leaf valve 19 provided at the upper end of the partition member 18, and the leaf valve 19 prevents the flow of hydraulic oil from the oil chamber 15 toward the pressure side chamber R1. At the same time, resistance is given to the flow of liquid from the pressure side chamber R1 to the oil chamber 15. That is, in the shock absorber D, the partition member 18 and the leaf valve 19 constitute a base valve.

  The other port 18b is configured to be opened and closed by a check valve 20 provided at the lower end of the partition member 18. The check valve 20 prevents the flow of hydraulic oil from the pressure side chamber R1 to the oil chamber 15, Only the flow of liquid from the oil chamber 15 toward the pressure chamber R1 is allowed.

  The shock absorber D thus configured has a telescopic type in which the upper end in FIG. 2 of the reservoir cylinder 10 is coupled to the outer tube 21 of the front fork F and the lower end of the piston rod 11 is coupled to the inner tube 22 of the front fork F. The piston rod 11 is set in a so-called inverted type in which the piston rod 11 is disposed below the cylinder 1.

  A suspension spring 23 arranged in parallel with the shock absorber D is interposed between the outer tube 21 and the inner tube 22, and this suspension spring 23 urges the front fork F in the extending direction, and the front fork F When the vehicle is interposed between the axle of the motorcycle and the vehicle body, the vehicle body is elastically supported.

  When the inner tube 22 is extended with respect to the outer tube 21 in the front fork F, the leaf valve 12 causes the hydraulic oil to flow from the expansion side chamber R2 to the compression side chamber R1 via the expansion side port 2b of the piston 2. A resistance is applied to cause a predetermined pressure loss, and a predetermined extension side damping force is generated in the shock absorber D. During this extension operation, the check valve 20 is opened, and the volume of hydraulic oil in which the piston rod 11 is withdrawn from the cylinder 1 is supplied from the oil chamber 15 into the cylinder 1 via the port 18b to compensate for the volume in the cylinder 1. Is made.

  On the other hand, during the compression operation in which the inner tube 22 intrudes into the outer tube 21 in the front fork F, the volume of hydraulic oil that the piston rod 11 enters into the cylinder 1 becomes excessive in the cylinder 1 and passes through the port 18a. The oil is discharged from the cylinder 1 to the oil chamber 15, and resistance is given to the flow of the hydraulic oil by the leaf valve 12 to increase the pressure in the cylinder 1. In the case of the shock absorber D, during the compression operation, a damping force on the compression side is generated in the shock absorber D mainly by the pressure increase in the cylinder 1 by the leaf valve 12. In the valve structure of the present invention, the pressure side port of the piston 2 is used. The leaf valve 3 applies resistance to the flow of hydraulic oil from the compression side chamber R1 to the expansion side chamber R2 via 2a, and this leaf valve 3 generates a differential pressure between the compression side chamber R1 and the expansion side chamber R2. At least, it acts to increase the damping force on the compression side of the shock absorber D and contributes to the generation of the compression side damping force of the shock absorber D.

  Hereinafter, the valve structure contributing to the generation of the compression side damping force as described above will be described in detail. The leaf valve 3 has an annular shape, and is laminated on the lower end in FIG. 1 of the piston 2 so as to be slidable on the outer periphery of a cylinder 25 that is a shaft member held by a piston holder 24 that connects the piston 2 to the piston rod 11. The leaf valve 3 is mounted, and is urged toward the piston 2 by leaf springs 4 and 5 disposed below the leaf valve 3 in FIG.

  The leaf valve 3 in this embodiment is configured as a laminated leaf valve by laminating a plurality of annularly formed plates. The number of the annular plates is a damping characteristic (piston) realized by this valve structure. The relationship between the damping force and the speed may be arbitrary, and may be plural or only one depending on the damping characteristics generated in the shock absorber D. Also, as shown, the damping generated in the shock absorber D Depending on the characteristics, the outer diameter of each plate can be set differently.

  The piston holder 24 includes a top cylindrical base portion 24a that is screwed to the tip of the piston rod 11, a shaft portion 24b that rises from the top portion of the base portion 24a and is mounted with the piston 2, and a top portion and a shaft portion 24b of the base portion 24a. And a horizontal hole 24d that opens from the side of the top of the base 24a and communicates with the vertical hole 24c.

  The shaft portion 24b of the piston holder 24 includes a guide member 26, a cylinder 25, an annular anti-leaf valve side spacer 27, an annular leaf spring 5, an annular intermediate spacer 28, an annular leaf spring 4, and an annular leaf valve side. The spacer 29, the leaf valve 3, the piston 2, the leaf valve 12, and the valve stopper 30 for regulating the bending amount of the leaf valve 12 are assembled in order from the bottom in the figure.

  The piston 2, the leaf valve 12, the cylinder 25, and the guide member 26 mounted on the shaft portion 24 b are fixed to the piston holder 24 so as not to move by the base portion 24 a of the piston holder 24 and the piston nut 31. The spacer 27, the leaf spring 5, the intermediate spacer 28, the leaf spring 4, and the leaf valve side spacer 29 are attached to the outer periphery of the cylinder 25.

  Specifically, the anti-leaf valve side spacer 27, the leaf spring 5, the leaf spring 4, and the leaf valve side spacer 29 are in sliding contact with the outer periphery of the cylinder 25, and these move in the axial direction with respect to the cylinder 25. It is possible.

  Then, when the base portion 24 a of the piston holder 24 is screwed to the tip of the piston rod 11, the assembled piston portion is connected to the piston rod 11.

  In the shock absorber D, a needle-type valve element 32 is accommodated in the piston holder 24, and the needle-type valve 32 is disposed with respect to an annular valve seat 33 provided in the middle of the vertical hole 24c. By making the distance closer, the flow path area in the bypass path that bypasses the ports 2a and 2b formed by the vertical hole 24c and the horizontal hole 24d can be changed.

  The needle-type valve element 32 is connected to a control rod 34 inserted into the hollow piston rod 11, and the needle-type valve element 32 is moved to the annular valve seat 33 by operating the control rod 34 externally. The flow path area in the bypass path can be adjusted. Since the bypass path bypasses the ports 2a and 2b, the damping force on the expansion side and the compression side of the shock absorber D can be adjusted by adjusting the flow path area. This can be done from the outside of the fork F.

  Returning, the leaf springs 4 and 5 are each constituted by laminating a plurality of annular plates, and the spring constant can be adjusted by the number of laminated annular plates. Even if the spring constant is increased, the leaf springs 4 and 5 do not increase in size in the radial direction and hardly increase in size in the axial direction. Therefore, it can be applied without difficulty in the shock absorber D having a small piston diameter. The number of annular plates can be set to an arbitrary number according to the spring constant, and may be singular. The spring constant may be set by adjusting the plate thickness.

  Further, the anti-leaf valve side spacer 27 and the leaf valve side spacer 29 are formed by laminating a plurality of annular plates, and the outer diameter is set smaller than the outer diameters of the leaf springs 4 and 5. When the valve 3 moves away from the piston 2, the leaf spring 4 bends with the outer edge of the leaf valve side spacer 29 as a fulcrum, and the leaf spring 5 deflects with the outer edge of the anti-leaf valve side spacer 27 as a fulcrum. It is supposed to be.

  The leaf springs 4 and 5, the anti-leaf valve side spacer 27 and the leaf valve side spacer 29 are slidably mounted on the cylinder 25 which is a cylinder member. The fulcrum of bending of the leaf springs 4 and 5 is always kept constant, and the urging force for urging the leaf valve 3 may vary every time the leaf springs 4 and 5 are bent. Absent.

  Subsequently, the inner diameter of the intermediate spacer 28 is set to be larger than the outer diameters of the anti-leaf valve side spacer 27 and the leaf valve side spacer 29, and the outer diameter is larger than the outer diameters of the leaf springs 4 and 5. The outer periphery is set in sliding contact with the inner periphery of the cylindrical portion 26 b of the guide member 26.

  The intermediate spacer 28 is inserted in order to form a gap on the inner peripheral side of the leaf springs 4, 5, and the leaf springs 4, 5 approach each other on the inner peripheral side by interposing the intermediate spacer 28. So that it can be bent. Further, the leaf springs 4 and 5 are bent with the inner edge of the intermediate spacer 28 as a fulcrum, and the maximum bending amount of the leaf spring 4 is restricted by the axial length of the intermediate spacer 28.

  In the case of this embodiment, the leaf springs 4 and 5 are maintained in a slightly bent state when assembled to the shaft portion 24b of the piston holder 24 to generate an initial load, and the leaf valve is generated with the initial load. 3 is urged in the direction of pressing against the piston 2.

  As described above, the leaf spring 4 and the leaf valve side spacer 29 are mounted on the outer periphery of the tube 25 so as to be movable in the axial direction, and the leaf spring 4 is allowed to move downward in FIG. When the pressure received from the upper surface side in FIG. 2 acts on the leaf valve 3 during the compression operation of the shock absorber D, and the thrust for pushing the leaf valve 3 downward in FIG. The leaf valve 3 is bent and lifted downward from the piston 2 so that the pressure side port 2a can be opened largely.

  In this way, the leaf springs 4 and 5 are bent with the outer edge of the anti-leaf valve side spacer 27, the inner edge of the intermediate spacer 28, and the outer edge of the leaf valve side spacer 29 as fulcrums. In addition to this adjustment, the spring constant of the urging means comprising the leaf springs 4 and 5 can be adjusted by setting the outer diameter of the anti-leaf valve side spacer 27 and the leaf valve side spacer 29 and the inner diameter of the intermediate spacer 28. is there.

  The guide member 26 includes a bottom portion 26a having a hole through which the shaft portion 24a of the piston holder 24 is inserted, and a cylindrical portion 26b that rises from the outer periphery of the bottom portion 26a. Even if the spacer 28 moves downward in FIG. 2, the cylindrical portion 26 b always faces the intermediate spacer 28.

  Therefore, the intermediate spacer 28 is positioned in the radial direction by the guide member 26. By providing the guide member 26, the intermediate spacer 28 can be fixed to any one of the leaf springs 4 and 5 by adhesion or welding. Positioning is not required, the fulcrum of bending of the leaf springs 4 and 5 is always constant, and the urging force for urging the leaf valve 3 does not vary every time the leaf springs 4 and 5 are bent. Of course, when the guide member 26 is not provided, the intermediate spacer 28 may be fixed to either or both of the leaf springs 4 and 5. It is not intended to prevent fixing to both or both.

  Further, when the leaf springs 4 and 5 are in sliding contact with the inner periphery of the cylindrical portion 26 b of the guide member 26, the anti-leaf valve side spacer 27 is fixed to the leaf spring 5 and the leaf valve side spacer 29 is fixed to the leaf spring 4. Since the leaf springs 4 and 5, the anti-leaf valve side spacer 27 and the leaf valve side spacer 29 are all guided by the guide member 26, it is necessary to slidably contact these members with the cylinder 25 on the outer periphery. Alternatively, the inner diameters of the leaf springs 4, 5, the anti-leaf valve side spacer 27 and the leaf valve side spacer 29 may be set larger than the outer diameter of the cylinder 25.

  The anti-leaf valve side spacer 27 creates a gap between the outer peripheral side of the leaf spring 5 and the bottom portion 26a of the guide member 26 so that the leaf spring 5 can be bent. The axial length of the anti-leaf valve side spacer 27 in the vertical direction in FIG. 2 is the maximum amount of bending when the leaf spring 5 abuts against the bottom 26a of the guide member 26 and further bending is restricted. By configuring the anti-leaf valve side spacer 27 by laminating annular plates, the maximum deflection amount of the leaf spring 5 can be easily adjusted by setting the number of laminated plates. The valve side spacer 27 can be a single annular plate.

  Further, the leaf valve side spacer 29 creates a gap between the leaf valve 3 and the outer peripheral side of the leaf spring 4 so that the outer periphery of the leaf valve 3 can be bent. The axial length of the leaf valve side spacer 29 in the vertical direction in FIG. 2 is the maximum deflection amount when the leaf valve 3 abuts against the leaf valve side spacer 29 and further deflection is restricted. In addition, by configuring the leaf valve side spacer 29 by laminating an annular plate, the maximum deflection amount of the leaf valve 3 can be easily adjusted by setting the number of laminated plates. Can be a single annular plate.

  Although not shown, the guide member 26, the intermediate spacer 28, and the leaf springs 4 and 5 seal the gap between the guide member 26 and the leaf spring 5 and the gap between the leaf springs 4 and 5 to seal the plate. When there is a risk of hindering the bending of the springs 4 and 5, the leaf springs 4 and 5 and the guide member 26 may be provided with holes or notches that prevent the air gaps from being sealed.

  In the valve structure configured in this way, the leaf valve 3 that opens and closes the compression side port 2a is urged by the leaf springs 4 and 5 having a small individual difference in the spring constant. Compared to a conventional valve structure using a coil spring, variation in the generated damping force in the shock absorber D for each product can be suppressed. Further, the variation can be minimized by the number of laminated annular plates constituting the leaf springs 4 and 5.

  Further, in order to increase the spring constant of the leaf springs 4 and 5, even if the number of laminated annular plates constituting the leaf springs 4 and 5 is increased or the plate thickness of the leaf springs 4 and 5 is increased, the shaft Since it does not become long in the direction, an increase in the size of the piston portion can be avoided, so that a sufficient urging force can be applied to the leaf valve 3 without sacrificing the stroke length of the shock absorber D.

  Therefore, by setting the initial load by the leaf springs 4 and 5 appropriately, when the compression speed is in the low speed range, only the outer periphery of the leaf valve 3 is bent without lifting the leaf valve 3, and the piston speed is increased. Accordingly, the damping force can be sufficiently generated in the shock absorber D in the low speed range.

  Further, since the leaf valve 3 can be sufficiently urged by the leaf springs 4 and 5, when the vibration direction of the shock absorber D is reversed from the compression direction to the extension direction, the leaf valve 3 is quickly moved to the compression side port 2a. Can be returned to the closing position, and the damping force immediately after the shock absorber D is switched from the compression stroke to the expansion stroke does not become insufficient.

  Therefore, according to the valve structure described above, a stable damping force can be generated in the shock absorber D, and a sufficient damping force can be generated even when the expansion / contraction speed of the shock absorber D is in a low speed range. It is.

  Since the pair of leaf springs 4 and 5 are used, even if the piston diameter is small and the outer diameter of the leaf springs 4 and 5 cannot be set large, the two leaf springs 4 and 5 are bent, so the leaf valve The maximum lift amount of 3 can be secured, and even if the spring constant in the biasing means is set large, it does not increase in size in the axial direction and the radial direction, so that it is suitable for a shock absorber with a small piston diameter. It is optimal for the damping valve on the pressure side of the shock absorber D built in the front fork F.

  In addition, an anti-leaf valve side spacer 27, an intermediate spacer 28, and a leaf valve side spacer 29 are provided, and a leaf spring 5 is interposed between the anti-leaf valve side spacer 27 and the intermediate spacer 28 so that the intermediate spacer 28 and the leaf valve side are provided. Since the configuration in which the leaf spring 4 is interposed between the spacers 29 is adopted, the maximum deflection amount of the leaf springs 4 and 5 can be arbitrarily set, and the lift of the leaf valve 3 with respect to the compression speed of the shock absorber D The amount can be set freely. Specifically, for example, in the process of the leaf valve 3 being lifted, even if the bending of one leaf spring 4 (5) is restricted, the other leaf spring 5 (4) is further bent. In this way, when the compression speed exceeds a certain speed, it is possible to set the characteristic of the lift amount of the leaf valve 3 to change with respect to the speed, and the degree of freedom in designing the damping characteristics is improved. Become.

 In the above description, the shock absorber D includes the base valve. However, it is also possible to adopt a configuration in which this is eliminated and the damping force on the compression side is generated only by the leaf valve 3 in the valve structure described above. is there.

 Further, in the present embodiment, the shock absorber D is applied to the front fork F. However, it is natural that the valve structure of the present invention can be held and used other than the shock absorber D applied to the front fork F. Even when applied to the front fork F, it may be arranged upside down instead of upside down instead of upside down.

 In this embodiment, the piston 2 is connected to the piston rod 11 via the piston holder 24. However, when the piston 2 is directly connected to the piston rod 11, the cylinder 25 serving as the shaft member is used. May be mounted on the outer periphery of the piston rod 11. Further, the cylinder 25 is removed and the shaft member is used as the piston rod 11 or the shaft portion 24b of the piston holder 24, and the leaf valve 3 and the leaf springs 4 and 5 are directly attached to the outer periphery of the piston rod 11 or the shaft portion 24b of the piston holder 24. You may do it.

 This is the end of the description of the embodiment of the present invention, but the scope of the present invention is not limited to the details shown or described.

It is a longitudinal cross-sectional view in the piston part in which the valve structure of the shock absorber in one embodiment was embodied. It is the figure which applied the buffer which embodied the valve structure of the buffer in one embodiment to a front fork.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Cylinder 2 Piston 2a Pressure side port 2b which is a port Extension side port 3, 12, 19 Leaf valve 4, 5 Leaf spring 10 Reservoir cylinder 11 Piston rod 13 Free piston 14 Air chamber 15 Oil chamber 16 Sealing member 17 Spring 18 Partition member 18a , 18b Port 20 in partition member Check valve 21 Outer tube 22 Inner tube 23 Suspension spring 24 Piston holder 24a Piston holder base 24b Piston holder shaft 24c Piston holder vertical hole 24d Piston holder horizontal hole 25 Piston holder cylinder 26 Guide member 26a Bottom portion 26b of guide member Cylindrical portion 27 of guide member Anti-leaf valve side spacer 28 Intermediate spacer 29 Leaf valve side spacer 30 Valve stopper 31 Piston nut 32 D Dollar valve 33 Annular valve seat 34 Control rod D Shock absorber F Front fork R Reservoir R1 Pressure side chamber R2 Extension side chamber

Claims (4)

A piston that is slidably inserted into the cylinder to form a compression side chamber and an extension side chamber in the cylinder, and has a port that communicates the compression side chamber and the extension side chamber, and is movable in the axial direction to the extension side chamber side of the piston And a biasing means for biasing the leaf valve toward the piston side, and the biasing means is a pair of leaf springs. And a leaf valve is urged by the elastic force of the leaf springs. The urging means includes an annular leaf valve side spacer interposed between the leaf spring on the leaf valve side and the leaf valve, and an inner diameter larger than the outer diameter of the leaf valve side spacer while being interposed between the leaf springs. An annular intermediate spacer provided, and an annular anti-leaf valve side spacer having an outer diameter smaller than the inner diameter of the intermediate spacer when laminated on the side of the anti-leaf valve side of the leaf spring on the anti-leaf valve side The valve structure of the shock absorber according to claim 1. A shaft member rising from a shaft core portion of the piston is provided, and a leaf valve, each leaf spring, a leaf valve side spacer, and an anti-leaf valve side spacer are slidably mounted on the outer periphery of the shaft member. Item 3. The shock absorber valve structure according to Item 2. 3. The cylindrical guide member for setting the outer diameter of the intermediate spacer to be equal to or larger than the outer diameter of the leaf spring and slidingly contacting the outer periphery of the intermediate spacer to position the intermediate spacer in the radial direction is provided. The valve structure of the described shock absorber.

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