Attenuation valve and buffer

Abstract

To provide an attenuation valve and a buffer that can be assembled well and can improve the flexibility of attenuation characteristics.SOLUTION: An attenuation valve V of the present invention includes: a circular valve seat member 1 having a plurality of ports 1b, 1c and seats 1d, 1e; and annular stacked leaf valves 2, 3 stacked on the valve seat member 1, the stacked leaf valves allowing warpage on an outer peripheral side and moving onto and away from the seat parts 1d, 1e to open and close the ports 1b, 1c. The stacked leaf valves 2, 3 include: circular first leaf valves 2a, 3a; and circular second leaf valves 2b, 3b, laid over an opposite valve seat side surface, which is a back surface of the first leaf valves 2a, 3a. The second leaf valves 2b, 3b include holes 2b1, 2b2, 3b1 facing the first leaf valves 2a, 3a in an axial direction and notch passages 2b3, 2b4, 3b2 being open from an outer periphery and in communication with the holes 2b1, 2b2, 3b1.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a damping valve and a shock absorber. [Background technology]

[0002] A shock absorber is used, for example, by being interposed between the body and axle of a vehicle in order to improve the ride comfort of the vehicle, and suppresses vibration of the body and wheels by the damping force that it exerts when expanding and contracting.

[0003] Such a shock absorber includes, for example, a cylinder, a piston rod movably inserted into the cylinder, a piston slidably inserted into the cylinder to divide the inside of the cylinder into an extension side chamber and a compression side chamber, a free piston slidably inserted into the cylinder to divide an air chamber below the compression side chamber in the cylinder, a damping passage provided in the piston to communicate between the extension side chamber and the compression side chamber, and a damping valve provided in the damping passage.

[0004] A damping valve, for example, includes a piston that is slidably inserted into the cylinder of the shock absorber to divide the inside of the cylinder into an extension side chamber and a compression side chamber, and that has a port that connects the extension side chamber and the compression side chamber and a seat portion that surrounds the outer periphery of the port, and a laminated leaf valve that is annular, has an inner periphery as a fixed end and is fixed to a piston rod, and has an outer periphery as a free end and is allowed to flex, and is laminated on the piston.

[0005] In such a damping valve, in order to smooth the opening operation of the laminated leaf valve when the laminated leaf valve bends and moves away from the seat part, there is an attempt to gradually open the laminated leaf valve from one or more circumferential points. In such a damping valve, a ring having a two-sided outer periphery is stacked on the back side of the first leaf valve that abuts on the seat part of the laminated leaf valve made of multiple leaf valves, making it easier to open the part of the leaf valve that is not supported by the ring (for example, see Patent Document 1). In addition to this, there is also a damping valve in which a spacer that is stacked on the laminated leaf valve and restrains the inner periphery of the laminated leaf valve is D-shaped, and the apparent rigidity of the laminated leaf valve as a whole is changed in the circumferential direction, so that the laminated leaf valve opens from the part with weak rigidity. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2006-194336 A Summary of the Invention [Problem to be solved by the invention]

[0007] Conventional damping valves are excellent in that they can smooth the opening action by opening only part of the leaf valve, thereby suppressing pressure fluctuations that occur when the entire circumference of the leaf valve suddenly moves away from the seat, and can mitigate the generation of abnormal noise and sudden changes in damping force. However, they require the leaf valve to be stacked with a spacer and leaf valve that have a different outer peripheral shape from the leaf valve, making assembly difficult and limiting the freedom of damping force characteristics in the damping valve.

[0008] SUMMARY OF THE PRESENT EMBODIMENTS An object of the present invention is to provide a damping valve and a shock absorber that are easy to assemble and can improve the degree of freedom of damping force characteristics. [Means for solving the problem]

[0009] In order to solve the above-mentioned problems, the damping valve of the present invention comprises a valve seat member which is circular and has a plurality of ports arranged in a circumferential direction and a seat portion surrounding the outer circumferential sides of the ports, and a laminated leaf valve which is annular and laminated on the valve seat member, has an inner circumferential side as a fixed end and an outer circumferential side as a free end which is allowed to flex and seat on and off the seat portion to open and close the port, the laminated leaf valve having an annular first leaf valve and an annular second leaf valve laminated on the anti-seat side which forms the back surface of the first leaf valve, and the second leaf valve has a hole axially facing the first leaf valve and a notched passage which opens from the outer periphery and leads to the hole.

[0010] According to the damping valve configured in this manner, the first leaf valve and the second leaf valve that constitute the stacked leaf valve are both annular in shape, which makes it easy to assemble, and by adjusting the position, opening area and circumferential width of the hole provided in the second leaf valve, the position, ease of bending and circumferential length of the flexible portion in the stacked leaf valve can be adjusted as desired.

[0011] Furthermore, the stacked leaf valves in the damping valve may include a third leaf valve that is annular and stacked on the back side of the second leaf valve and capable of closing the hole of the second leaf valve. According to a damping valve configured in this manner, the third leaf valve is stacked on the back side of the second leaf valve, so that the overall rigidity of the stacked leaf valve is higher than when it is composed of the first leaf valve and the second leaf valve, and the generated damping force can be increased and the rigidity difference in the circumferential direction of the stacked leaf valve can be reduced, so that the difference in the amount of deflection of the stacked leaf valve in the initial stage of valve opening is reduced in the circumferential direction, thereby alleviating stress during the valve opening operation and mitigating changes in damping force in the initial stage of valve opening.

[0012] Furthermore, the stacked leaf valves in the damping valve may include a fourth leaf valve that is annular and has an outer diameter smaller than that of the second leaf valve, and is stacked on the back side of the second leaf valve facing part of the hole. With a damping valve configured in this manner, compared to a case in which a third leaf valve having the same inner and outer diameters as the second leaf valve is stacked on the back side of the second leaf valve, the overall rigidity of the stacked leaf valve is lower, making it possible to reduce the generated damping force, and the difference in rigidity in the circumferential direction of the stacked leaf valve is larger, making the difference in the amount of deflection of the stacked leaf valve 2 in the circumferential direction larger, making it possible to slightly increase the change in damping force in the initial stage of valve opening.

[0013] Furthermore, the stacked leaf valves in the damping valve may include a fifth leaf valve that is annular and has an outer diameter smaller than that of the second leaf valve, and is stacked on the back side of the second leaf valve without facing the hole. With a damping valve configured in this manner, compared to a case in which a third leaf valve having the same inner and outer diameters as the second leaf valve is stacked on the back side of the second leaf valve, the overall rigidity of the stacked leaf valve is further reduced, making it possible to further reduce the generated damping force, and the difference in rigidity in the circumferential direction of the stacked leaf valve is further increased, making the difference in the amount of deflection of the stacked leaf valve in the circumferential direction at the initial stage of valve opening larger, thereby making it possible to increase the change in damping force at the initial stage of valve opening.

[0014] Furthermore, the second leaf valve in the damping valve has a pair of arms facing each other with a notched passage between them on the outer circumferential side of the hole, and the arms may have different radial lengths, and the notched passage may communicate with a position biased from the circumferential center to the circumferential end of the hole. According to the damping valve configured in this manner, the rigidity of the installation location of the hole of the second leaf valve can be set to differ in the circumferential direction, so that the ease of bending can be changed in the circumferential direction in the flexible portion of the laminated leaf valve, and the degree of freedom of the damping force characteristics can be further improved.

[0015] Furthermore, the shock absorber of the present invention includes an outer tube, a rod inserted into the outer tube so as to be movable in the axial direction, a shock absorber body having at least two working chambers through which liquid flows as the rod moves relative to the outer tube, and a damping valve provided between the working chambers. The shock absorber configured in this manner provides good assembly and improves the degree of freedom in damping force characteristics. Effect of the Invention

[0016] The damping valve and shock absorber of the present invention are easy to assemble and provide improved freedom in damping force characteristics. [Brief description of the drawings]

[0017] [Figure 1] FIG. 1 is a vertical sectional view of a shock absorber to which a damping valve according to an embodiment of the present invention is applied. [Diagram 2] FIG. 2 is an enlarged cross-sectional view of a damping valve according to an embodiment of the present invention. [Diagram 3] FIG. 3 is a plan view of the second leaf valve on the expansion side in the damping valve according to one embodiment of the present invention. [Figure 4] FIG. 4 is a plan view of a second leaf valve on the compression side in a damping valve according to an embodiment of the present invention. [Diagram 5] FIG. 5 is a plan view of a modified example of the second leaf valve on the compression side in the damping valve according to an embodiment of the present invention. [Figure 6] FIG. 6 is a plan view of a damping valve in a first modified example of an embodiment of the present invention. [Figure 7] FIG. 7 is a plan view of a damping valve in a second modified example of an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] The present invention will be described below based on the embodiment shown in the drawings. As shown in FIG. 1, the damping valve V in one embodiment is applied to the piston part of a shock absorber D, and includes a piston 1 as a valve seat member having ports 1b, 1c and seat parts 1d, 1e surrounding the ports 1b, 1c, and laminated leaf valves 2, 3 for opening and closing the ports 1b, 1c. As shown in FIG. 1, the shock absorber D to which the damping valve V is applied includes a shock absorber body A that is expandable and contractable and has a cylinder 10 as an outer tube and a rod 11 movably inserted into the cylinder 10, and a damping valve V provided between an expansion side chamber R1 and a compression side chamber R2 as two working chambers provided in the shock absorber body A. In the case of this shock absorber D, it is used by being interposed between a vehicle body and an axle of a vehicle (not shown) to suppress vibration of the vehicle body and wheels.

[0019] Hereinafter, each part of the damping valve V and the shock absorber D will be described in detail. First, the shock absorber main body A includes a bottomed cylindrical cylinder 10 serving as an outer tube, a rod 11 movably inserted into the cylinder 10, and a piston 1 serving as a valve seat member connected to the rod 11 and movably inserted into the cylinder 10, which divides the inside of the cylinder 10 into an expansion-side chamber R1 and a compression-side chamber R2 serving as working chambers, as shown in FIG.

[0020] A bracket (not shown) is provided at the base end of the rod 11, which is the upper end in Fig. 1, and the rod 11 is connected to one of the vehicle body and the axle via the bracket (not shown). A bracket (not shown) is also provided at the bottom 10a of the cylinder 10, and the cylinder 10 is connected to the other of the vehicle body and the axle via the bracket (not shown).

[0021] In this way, the shock absorber D is interposed between the vehicle body and the axle. When the vehicle runs on an uneven road surface and the wheels vibrate up and down relative to the vehicle body, the rod 11 moves in and out of the cylinder 10, the shock absorber D expands and contracts, and the piston 1 moves up and down (axially) within the cylinder 10.

[0022] The shock absorber body A also includes an annular rod guide 13 that closes the upper end of the cylinder 10 and through which the rod 11 is slidably inserted along its inner periphery. Thus, the inside of the cylinder 10 is an enclosed space. A free piston 14 is slidably inserted into the cylinder 10 on the opposite side of the piston 1 from the rod 11.

[0023] A liquid chamber L is formed above the free piston 14 in the cylinder 10, and an air chamber G is formed below it. The liquid chamber L is further divided by the piston 1 into an extension side chamber R1 on the rod 11 side and a compression side chamber R2 on the piston side, and the extension side chamber R1 and the compression side chamber R2 are each filled with liquid. The liquid filled in the shock absorber body A may be hydraulic oil, water, an aqueous solution, or other liquid. On the other hand, the air chamber G is filled with compressed air or a gas such as nitrogen gas.

[0024] When the rod 11 retreats from the cylinder 10 during the extension operation of the shock absorber D, the free piston 14 moves upward within the cylinder 10 in accordance with the volume of the retreated rod 11, expanding the air chamber G and compensating for the volume of the rod 11 retreating from the cylinder 10. Conversely, when the shock absorber D contracts, the rod 11 advances into the cylinder 10, and the free piston 14 moves downward within the cylinder 10 in accordance with the volume of the advanced rod 11, contracting the air chamber G and compensating for the volume of the rod 11 entering the cylinder 10. Note that instead of the free piston 14, a bladder, a bellows, or the like may be used to separate the liquid chamber L and the air chamber G, and the configuration of the movable partition that serves as this partition can be changed as appropriate.

[0025] As described above, in this embodiment, the shock absorber D is a single-rod, single-cylinder shock absorber, and when the shock absorber D expands or contracts, the free piston (movable partition) 11 expands or contracts the air chamber G to compensate for the volume of the rod 11 moving in and out of the cylinder 10. However, the configuration for this volume compensation can also be changed as appropriate. For example, when the free piston 14 and the air chamber G are eliminated and an outer tube is provided outside the cylinder 10, and a reservoir for storing liquid and gas is formed between the cylinder 10 and the outer tube to make the shock absorber a double-cylinder shock absorber, the volume of the rod 11 moving in and out of the cylinder 10 may be compensated for by the reservoir. The reservoir may be formed in a tank separate from the cylinder 10. The shock absorber D may also be configured as a double-rod shock absorber in which the piston 14 is attached to the center of the rod 11 and the ends of the rod 11 protrude outside the cylinder 10 from both ends of the cylinder 10.

[0026] The rod 11 has a reduced outer diameter at the tip side, and is equipped with a small diameter portion 11a having a small outer diameter at the tip side, a large diameter portion 11b having an outer diameter larger than that of the small diameter portion 11a and provided above the small diameter portion 11a in Figure 1, a step portion 11c provided at the boundary between the small diameter portion 11a and the large diameter portion 11b, and a screw portion 11d provided on the outer periphery of the tip of the small diameter portion 11a.

[0027] The damping valve V of this embodiment is attached to a rod 11 and applied to a piston portion of a shock absorber D. As shown in Fig. 1, a piston 1 serving as a valve seat member constituting the damping valve V is annular and fitted onto the outer periphery of a small diameter portion 11a of the rod 11, and is fixed to the rod 11 by a piston nut 15 that is screwed onto a threaded portion 11d of the rod 11. The piston 1 is also attached to the rod 11, and its outer periphery is in sliding contact with the inner periphery of a cylinder 10, dividing the inside of the cylinder 10 into an expansion-side chamber R1 and a compression-side chamber R2 that serve as working chambers.

[0028] More specifically, the piston 1 includes a circular main body portion 1a, a plurality of extension-side ports 1b provided in the main body portion 1a and opening from the lower end of the main body portion 1a in Figure 2 and leading to the upper end in Figure 2, a plurality of ports 1c opening from the upper end of the main body portion 1a in Figure 2 and leading to the lower end in Figure 2, a seat portion 1d protruding downward from the lower end of the main body portion 1a in Figure 2 and surrounding the outer periphery of port 1b, and a seat portion 1e protruding upward from the upper end of the main body portion 1a in Figure 2 and surrounding the outer periphery of port 1c.

[0029] As described above, the main body 1a is annular, and its outer periphery is in sliding contact with the inner periphery of the cylinder 10. In addition to the seat portions 1d and 1e, the main body 1a is provided with an annular inner periphery seat portion 1f at its lower end, which protrudes downward from the inner periphery side of the lower opening end of port 1b, and an annular inner periphery seat portion 1g at its upper end, which protrudes upward from the inner periphery side of the upper opening end of port 1c, as shown in Fig. 2.

[0030] The port 1b is located at the upper end of the main body 1a in FIG. 2, opens from the outer circumferential side of the inner circumferential seat portion 1f, extends in the axial direction, and communicates with the lower end of the main body 1a in FIG. 2, and communicates between the expansion-side chamber R1 and the compression-side chamber R2. Note that a plurality of ports 1b are provided at equal intervals in the circumferential direction of the main body 1a. The port 1b is an expansion-side port that allows the flow of liquid from the expansion-side chamber R1 to the compression-side chamber R2 when the shock absorber D is expanded.

[0031] The port 1c is located at the lower end of the main body 1a in FIG. 2, opens from the outer periphery of the inner seat portion 1g, extends in the axial direction, and communicates with the upper end of the main body 1a in FIG. 2, and communicates between the expansion-side chamber R1 and the compression-side chamber R2. The ports 1c are provided on the main body 1a at equal intervals in the circumferential direction of the main body 1a, and the same number as the ports 1b. The ports 1c are compression-side ports that allow the flow of liquid from the compression-side chamber R2 to the expansion-side chamber R1 when the shock absorber D is contracting. The number of the expansion-side ports 1b and the compression-side ports 1c provided on the piston 1 can be arbitrarily changed in design.

[0032] In this embodiment, the seat portion 1d is provided at the lower end of the main body portion 1a in FIG. 2, has a petal shape when viewed in the axial direction, protrudes downward from the lower end of the main body portion 1a, is connected to the inner seat portion 1f, and surrounds the ports 1b independently, and functions as a valve seat on the expansion side. On the other hand, the seat portion 1e is provided at the upper end of the main body portion 1a in FIG. 2, has a petal shape when viewed in the axial direction, protrudes upward from the upper end of the main body portion 1a, is connected to the inner seat portion 1g, and surrounds the ports 1c independently, and functions as a valve seat on the compression side. Note that the seat portions 1d and 1e only need to surround the ports 1b and 1c and function as valve seats, and may be annular or the like in addition to the petal shape depending on the arrangement of the ports 1b and 1c relative to the main body portion 1a.

[0033] The stacked leaf valve 2 is formed by stacking annular leaf valves 2a, 2b, 2c, and is stacked at the bottom in Figure 2, which is the pressure side chamber side of the piston 1 serving as a valve seat member, and is fixed to the outer periphery of the small diameter portion 11a of the rod 11 together with the piston 1, with the inner periphery being the fixed end and the outer periphery being the free end, allowing deflection on the outer periphery side.

[0034] 2 of the piston 1 and abutting against the inner circumferential seat portion 1f and the seat portion 1d, a second leaf valve 2b which is annular and overlaps the anti-valve seat side surface which is the back surface of the first leaf valve 2a, and a third leaf valve 2c which is overlapped on the anti-valve seat side surface which is the back surface of the second leaf valve 2b. In this embodiment, the laminated leaf valve 2 includes a plurality of leaf valves which are annular and have an outer diameter smaller than that of the third leaf valve 2c and are stacked so as to gradually become smaller on the back surfaces of the three leaf valves, the first leaf valve 2a, the second leaf valve 2b, and the third leaf valve 2c, but leaf valves other than at least the first leaf valve 2a and the second leaf valve 2b may be eliminated or the number of stacked sheets may be changed. In addition, when providing an orifice in the damping valve V, a leaf valve with an orifice having a notched orifice opening from the outer periphery may be provided on the piston side of the first leaf valve 2a in the stacked leaf valve 2, or an orifice may be provided by stamping on the seat portion 1d of the piston 1 as the valve seat member.

[0035] 2, a spacer 4 having an outer diameter smaller than that of the laminated leaf valve 2 is stacked below the laminated leaf valve 2, and when the laminated leaf valve 2 is fixed to the small diameter portion 11a of the rod 11 together with the spacer 4, the laminated leaf valve 2 can bend with the outer circumferential edge of the spacer 4 as a fulcrum. When the laminated leaf valve 2 is stacked on the lower end of the piston 1 in FIG. 2, the uppermost first leaf valve 2a in FIG. 2 abuts against the inner circumferential seat portion 1f and the seat portion 1d to close the lower opening end in FIG. 2, which is the outlet end of the port 1b. When the laminated leaf valve 2 is subjected to the pressure of the expansion-side chamber R1 acting through the port 1b and is separated from the seat portion 1d, the outer circumferential side of the laminated leaf valve 2 is bent, and the port 1b is opened, and the liquid passes through the gap between the expansion-side chamber R1 and the seat portion 1d and flows from the expansion-side chamber R1 to the compression-side chamber R2, and the liquid is resisted against the flow. In this way, the laminated leaf valve 2 functions as an expansion-side damping valve that opens and closes the expansion-side port 1b to provide resistance to the flow of liquid from the expansion-side chamber R1 to the compression-side chamber R2.

[0036] In this embodiment, the first leaf valve 2a, the second leaf valve 2b, and the third leaf valve 2c all have the same inner diameter and outer diameter. The second leaf valve 2b sandwiched between the first leaf valve 2a and the third leaf valve 2c is annular as shown in FIG. 3, and has two arc-shaped holes 2b1 and 2b2 spaced apart in the circumferential direction near the center of the inner and outer peripheries in the radial direction. The second leaf valve 2b also has a notched passage 2b3 that opens from the outer periphery and communicates with the hole 2b1, and a notched passage 2b4 that opens from the outer periphery and communicates with the hole 2b2. Therefore, the rigidity of the second leaf valve 2b in the circumferential direction where the holes 2b1 and 2b2 are provided is low, making it easy to bend. Furthermore, the second leaf valve 2 has a pair of arms 2b5, 2b6 facing each other across the notched passage 2b3 on the outer circumferential side of the hole 2b1, and also has a pair of arms 2b7, 2b8 facing each other across the notched passage 2b3 on the outer circumferential side of the hole 2b2. In this manner, the second leaf valve 2 has the holes 2b1, 2b2 and the notched passages 2b3, 2b4 communicating with the holes 2b1, 2b2, so that pairs of arms 2b5, 2b6, 2b7, 2b8 are formed on the outer circumferential sides of the holes 2b1, 2b2, respectively.

[0037] The radial width of hole 2b1 is wider than the radial width of hole 2b2, and the circumferential length of hole 2b1 is longer than the circumferential length of hole 2b2. The rigidity of the second leaf valve 2b is lower in the portion where holes 2b1 and 2b2 are provided than in the portion where holes 2b1 and 2b2 are not provided, and in the circumferential direction, the portion where hole 2b1 is provided is the lowest, followed by the portion where hole 2b2 is provided.

[0038] In addition, the radial widths of the outer peripheral side portion of the hole 2b1 in the second leaf valve 2b are different on both sides of the notched passage 2b3, and the radial width of the arm 2b5 on the left side of the notched passage 2b3 is shorter than the radial width of the arm 2b6 on the right side of the notched passage 2b3 among the arms 2b5, 2b6 on the outer peripheral side of the hole 2b1 as viewed from the center of the second leaf valve 2b in Fig. 3, so that the rigidity of the second leaf valve 2b is lower on the left side of the notched passage 2b3 than on the right side as viewed from the center of the second leaf valve 2 in the portion where the hole 2b1 is provided. In this way, by making the radial width of the hole 2b1 different on both sides of the notched passage 2b3 and forming the arms 2b5, 2b6 with different radial lengths on the outer peripheral side of the hole 2b1, the rigidity of the installation location of the hole 2b1 of the second leaf valve 2b can be set to be different in the circumferential direction.

[0039] Further, as shown in Fig. 4, the notched passages 2b3 and 2b4 communicated with the holes 2b1 and 2b2 are communicated with the centers of the holes 2b1 and 2b2 in the circumferential direction of the second leaf valve 2b, but may be communicated with positions offset from the centers of the holes 2b1 and 2b2 toward the circumferential ends in the circumferential direction. In this way, by communicating the notched passage 2b3 with a position offset from the circumferential center of the hole 2b1 toward the circumferential end, the circumferential lengths of the arms 2b5 and 2b6 are made different, and the rigidity of the installation position of the hole 2b1 of the second leaf valve 2b can be set to be different in the circumferential direction. Also, as shown in Fig. 4, the notched passage 2b4 may be communicated with the circumferential end of the hole 2b2, and in this case, by communicating the notched passage 2b4 with the hole 2b2, only one arm 2b7 is formed on the outer circumferential side of the hole 2b2 in the second leaf valve 2b. Even in this way, the rigidity of the second leaf valve 2b in the circumferential direction at points where there are no arms on the outer periphery of the hole 2b2 can be reduced, so that the rigidity of the location of the hole 2b2 of the second leaf valve 2b can be set to vary in the circumferential direction.

[0040] When the second leaf valve 2b is overlapped on the first leaf valve 2a, the holes 2b1, 2b2 of the second leaf valve 2b face the first leaf valve 2a in the axial direction. When the third leaf valve 2c is overlapped on the second leaf valve 2b, the holes 2b2, 2b2 face the third leaf valve 2c in the axial direction. Therefore, in the stacked leaf valve 2 of this embodiment, the two holes 2b1, 2b2 of the second leaf valve 2b are covered by the first leaf valve 2a and the third leaf valve 2c, and are communicated with the compression side chamber R2, which is outside the stacked leaf valve 2, only by the notched passages 2b3, 2b4, respectively.

[0041] The laminated leaf valve 3 is formed by stacking annular leaf valves 3a, 3b, and 3c, and is stacked at the upper part in Figure 2, which is the extension side chamber side of the piston 1 serving as a valve seat member, and is fixed to the outer periphery of the small diameter portion 11a of the rod 11 together with the piston 1, with the inner periphery being the fixed end and the outer periphery being the free end, allowing deflection on the outer periphery side.

[0042] 2 of the piston 1 and abutting against the inner circumferential seat portion 1g and the seat portion 1e, a second leaf valve 3b which is annular and overlaps the anti-valve seat side surface which forms the back surface of the first leaf valve 3a, and a third leaf valve 3c which is overlapped on the anti-valve seat side surface which forms the back surface of the second leaf valve 3b. In this embodiment, the laminated leaf valve 3 includes a plurality of leaf valves which are annular and have an outer diameter smaller than that of the third leaf valve 3c and are stacked on the back surfaces of the three leaf valves, the first leaf valve 3a, the second leaf valve 3b, and the third leaf valve 3c, so as to gradually become smaller, but leaf valves other than at least the first leaf valve 3a and the second leaf valve 3b may be eliminated or the number of layers may be changed. In addition, when providing an orifice in the damping valve V, a leaf valve with an orifice having a notched orifice opening from the outer periphery may be provided on the piston side of the first leaf valve 3a in the stacked leaf valve 3, or an orifice may be provided by stamping on the seat portion 1e of the piston 1 as the valve seat member.

[0043] 2, a spacer 5 having an outer diameter smaller than that of the laminated leaf valve 3 is stacked above the laminated leaf valve 3, and when the laminated leaf valve 2 is fixed to the small diameter portion 11a of the rod 11 together with the spacer 4, the laminated leaf valve 3 can bend with the outer circumferential edge of the spacer 5 as a fulcrum. When the laminated leaf valve 3 is stacked on the upper end of the piston 1 in FIG. 2, the first leaf valve 3a at the bottom in FIG. 2 abuts against the inner circumferential seat portion 1g and the seat portion 1e, thereby closing the upper opening end in FIG. 2, which is the outlet end of the port 1c. When the laminated leaf valve 3 is separated from the seat portion 1e by bending the outer circumferential side under the pressure of the compression side chamber R2 acting through the port 1c, the laminated leaf valve 3 opens the port 1c, and allows the flow of liquid from the compression side chamber R2 to the expansion side chamber R1 through the gap between the seat portion 1e and provides resistance to the flow. In this way, the laminated leaf valve 3 functions as a compression-side damping valve that opens and closes the compression-side port 1c to provide resistance to the flow of liquid from the compression-side chamber R2 to the expansion-side chamber R1.

[0044] In this embodiment, the first leaf valve 3a and the second leaf valve 3b have the same inner diameter and outer diameter, and the third leaf valve 3c is annular and has the same inner diameter as the first leaf valve 3a and the second leaf valve 3b, but its outer diameter is smaller than the outer diameters of the first leaf valve 3a and the second leaf valve 3b.

[0045] The second leaf valve 3b sandwiched between the first leaf valve 3a and the third leaf valve 3c is annular as shown in FIG. 5, and has an arc-shaped hole 3b1 along the circumferential direction near the center of the inner and outer periphery in the radial direction. The second leaf valve 3b also has a notched passage 3b2 that opens from the outer periphery and communicates with the hole 3b1. Therefore, the rigidity of the portion of the second leaf valve 3b where the hole 3b1 is provided in the circumferential direction is low, and the second leaf valve 3b is easily bent. Note that the third leaf valve 3b may also be configured such that the rigidity of the location where the hole 3b1 of the third leaf valve 3b is provided is different in the circumferential direction by making the radial widths on both sides of the notched passage 3b1 on the outer periphery side of the hole 3b1 different, and further, the notched passage 3b2 that communicates with the hole 3b1 may communicate with a portion other than the center of the hole 3b1 in the circumferential direction of the second leaf valve 3b.

[0046] When the second leaf valve 3b is placed on the first leaf valve 3a, the hole 3b1 of the second leaf valve 3b faces the first leaf valve 3a in the axial direction. The outer diameter of the third leaf valve 3c is larger than a circle that is centered at the center of the second leaf valve 3b and touches the outer periphery of the hole 3b1, and is smaller than the outer diameter of the second leaf valve 3b. Therefore, when the third leaf valve 3c is placed on the second leaf valve 3b, the third leaf valve 3c partially overlaps the hole 3b1 in the axial direction to close the hole 3b1, but does not impede communication of the hole 3b1 with the expansion-side chamber R1 via the notch 3b2.

[0047] The compression side laminated leaf valve 3, the piston 1, and the extension side laminated leaf valve 2 thus constructed are assembled in this order to the outer periphery of the small diameter portion 11a of the rod 11, and then are sandwiched between the piston nut 15 screwed to the threaded portion 11d of the small diameter portion 11a and the step portion 11c of the rod 11 and fixed to the rod 11. An annular valve stopper 6 is stacked above the compression side laminated leaf valve 3 and attached to the small diameter portion 11a, and when the laminated leaf valve 3 bends and abuts against the valve stopper 6, further bending of the laminated leaf valve 3 is restricted, thereby protecting the laminated leaf valve 3. When the extension side laminated leaf valve 2 bends and abuts against the piston nut 15, further bending of the laminated leaf valve 2 is restricted, thereby protecting the laminated leaf valve 2.

[0048] The damping valve V and the shock absorber D are configured as described above, and their operation will be described below. First, when the shock absorber D performs an extension operation and the piston 1 moves upward in FIG. 1 relative to the cylinder 10, the liquid in the expansion-side chamber R1, which is compressed by the upward movement of the piston 1 in FIG. 1, bends the laminated leaf valve 2 and moves to the compression-side chamber R2 through the expansion-side port 1b. Therefore, when the shock absorber D performs an extension operation, the laminated leaf valve 2 provides resistance to the flow of liquid from the expansion-side chamber R1 to the compression-side chamber R2, increasing the pressure in the expansion-side chamber R1, so that the shock absorber D generates an extension-side damping force that hinders the extension operation. In addition, with the extension operation of the shock absorber D, the free piston 14 rises in FIG. 1 according to the volume of the rod 11 that retreats from the cylinder 10, expanding the air chamber G, and compensating for the volume of the rod 11 that retreats from the cylinder 10.

[0049] As shown in FIG. 3, the second leaf valve 2b in the laminated leaf valve 2 has two holes 2b1, 2b2 at positions shifted in the circumferential direction near the center of the inner and outer periphery in the radial direction. The opening area of ​​the hole 2b1 is larger than that of the hole 2b2, and the rigidity of the portion of the second leaf valve 2b where the hole 2b1 is provided is the lowest, and the rigidity of the portion where the hole 2b2 is provided is lower than the rigidity of a portion without a hole. In other words, there are two portions in the circumferential direction of the second leaf valve 2b where the rigidity is reduced, and the rigidity is changed in the circumferential direction. The first leaf valve 2a is most flexible at a portion axially facing the hole 2b1, which has the lowest rigidity, of the second leaf valve 2b laminated on the back surface, and next most flexible at a portion axially facing the hole 2b2, which has the lowest rigidity, of the second leaf valve 2b, and is less flexible at other portions.

[0050] Therefore, when the laminated leaf valve 2 receives the pressure of the expansion-side chamber R1 through the port 1b and opens, the outer periphery of the hole 2b1 of the laminated leaf valve 2 bends radially first and moves away from the seat portion 1d, then the outer periphery of the hole 2b2 bends radially and moves away from the seat portion 1d, and finally the outer periphery of the portion other than the holes 2b1 and 2b2 bends radially and moves away from the seat portion 1d. In this way, the entire circumference of the laminated leaf valve 2 does not move away from the seat portion 1d at once, but opens gradually in the above-mentioned order, so that the pressure fluctuation when the laminated leaf valve 2 opens is mitigated, and the generation of abnormal noise and a sudden change in damping force can be mitigated.

[0051] In this way, by providing the holes 2b1, 2b2 in the second leaf valve 2b, the outer periphery of the portion of the stacked leaf valve 2 where the holes 2b1, 2b2 are provided can be made flexible, so that the circumferential location of the stacked leaf valve 2 from which the valve is opened can be set depending on the circumferential location of the holes 2b1, 2b2 on the second leaf valve 2b. Also, since the second leaf valve 2b is provided with two holes 2b1, 2b2, the flexibility of the outer periphery of the holes 2b1, 2b2 in the stacked leaf valve 2 can be adjusted depending on the size of the opening area of ​​the holes 2b1, 2b2, so that the outer periphery of the hole 2b1 having a large opening area can be opened at an earlier timing, and the outer periphery of the hole 2b2 having a small opening area can be opened with a delay from the opening operation of the outer periphery of the hole 2b1. Furthermore, by setting the circumferential width of the holes 2b1, 2b2, the circumferential length of the easily flexible portion of the stacked leaf valve 2 can be set, and the circumferential width of the portion of the stacked leaf valve 2 that first opens can be tuned. The ease of opening of the stacked leaf valve 2 can also be tuned by the radial width of the holes 2b1, 2b2. The number of holes provided in the second leaf valve 2b may be one or three or more, and the design can be modified as appropriate depending on the type of opening operation of the stacked leaf valve 2.

[0052] In addition, since the holes 2b1 and 2b2 are communicated with the compression side chamber R2 through the notched passages 2b3 and 2b4, when the cylinder 10 is filled with liquid after the damping valve V is assembled and inserted into the cylinder 10, the holes 2b1 and 2b2 are also easily filled with liquid, so that gas is not left behind in the holes 2b1 and 2b2 and the laminated leaf valve 2 is repeatedly deflected, and the leftover gas does not escape from the holes 2b1 and 2b2 and enter the expansion side chamber R1 and the compression side chamber R2, which disturbs the damping force generated by the shock absorber D. Furthermore, the holes 2b1 and 2b2 are not sealed but are communicated with the compression side chamber R2 through the notched passages 2b3 and 2b4, and liquid can freely enter and exit the holes 2b1 and 2b2 when the laminated leaf valve 2 is deflected, so that excessive compression and pressure reduction do not occur in the holes 2b1 and 2b2, and the laminated leaf valve 2 can smoothly perform a valve opening operation.

[0053] Next, when the shock absorber D contracts and the piston 1 moves downward in FIG. 1 relative to the cylinder 10, the downward movement of the piston 1 causes the liquid in the compression-side chamber R2 to bend the compression-side stacked leaf valve 3 and move to the expansion-side chamber R1 through the compression-side port 1c.

[0054] More specifically, when the shock absorber D contracts, the pressure in the compression side chamber R2 acts on the lower surface of the laminated leaf valve 3 in FIG. 2 through the compression side port 1c, and the free end of the laminated leaf valve 3 is bent and separated from the seat portion 1e by the action of the pressure, and the liquid in the compression side chamber R2 moves to the expansion side chamber R1 through the gap between the laminated leaf valve 3 and the seat portion 1e. Therefore, when the shock absorber D contracts, the laminated leaf valve 3 provides resistance to the flow of liquid from the compression side chamber R2 to the expansion side chamber R1, increasing the pressure in the compression side chamber R2, so that the shock absorber D generates a compression side damping force that hinders the contraction operation. In addition, as the shock absorber D contracts, the free piston 14 descends in FIG. 1 according to the volume of the rod 11 that enters the cylinder 10, reducing the air chamber G, and the volume of the rod 11 that enters the cylinder 10 is compensated.

[0055] As shown in Fig. 5, the second leaf valve 3b in the stacked leaf valve 3 has a hole 3b1 near the center of the inner and outer periphery in the radial direction. The rigidity of the portion of the second leaf valve 3b where the hole 3b1 is provided is lower than the rigidity of a portion without the hole. The first leaf valve 3a is flexible at a portion in the axial direction facing the hole 3b1 of the second leaf valve 3b stacked on the back surface, which has a low rigidity, but is not flexible in other portions.

[0056] Therefore, when the laminated leaf valve 3 receives the pressure of the compression side chamber R2 through the port 1c and opens, the outer periphery of the hole 3b1 of the laminated leaf valve 3 bends radially first and moves away from the seat portion 1e, and then the outer periphery of the portion other than the hole 3b1 bends radially and moves away from the seat portion 1e. In this way, the laminated leaf valve 3 does not move away from the seat portion 1e all at once, but opens gradually in the above-mentioned order, so that pressure fluctuations when the laminated leaf valve 3 opens are mitigated, and the generation of abnormal noise and sudden changes in damping force can be mitigated.

[0057] In this way, the hole 3b1 is provided in the second leaf valve 3b, and the outer periphery of the laminated leaf valve 3 at the location where the hole 3b1 is provided can be easily bent. Therefore, the location of the hole 3b1 in the second leaf valve 3b in the circumferential direction can be set to determine which location in the circumferential direction of the laminated leaf valve 3 is opened. The ease of bending of the outer periphery of the hole 3b1 in the laminated leaf valve 3 can be adjusted by the size of the opening area of ​​the hole 3b1 in the second leaf valve 3b. The circumferential length of the easily bending part of the laminated leaf valve 3 can be set by setting the circumferential width of the hole 3b1, and the circumferential width of the part where the laminated leaf valve 3 first opens can be tuned. The ease of opening of the laminated leaf valve 3 can also be tuned by the radial width of the hole 3b1. The number of holes provided in the second leaf valve 3b may be one or more, and the design can be appropriately changed depending on the type of opening operation of the laminated leaf valve 3.

[0058] Furthermore, in the stacked leaf valve 3, the outer diameter of the third leaf valve 3c is smaller than the outer diameters of the first leaf valve 3a and the second leaf valve 3b, so that compared to the stacked leaf valve 2 in which the outer diameters are set to be the same, the first leaf valve 3a and the second leaf valve 3b are more likely to bend because their outer peripheries are not supported by the third leaf valve 3c. Therefore, the stacked leaf valve 3 can generate a lower damping force compared to the stacked leaf valve 2, and the difference in rigidity in the circumferential direction of the stacked leaf valve 3 becomes larger, so that the difference in the amount of deflection of the stacked leaf valve 3 in the circumferential direction at the initial stage of valve opening becomes larger, and the change in damping force at the initial stage of valve opening can be slightly larger.

[0059] In addition, since the hole 3b1 is connected to the expansion-side chamber R1 through the notched passage 3b2, when filling the cylinder 10 with liquid after assembling the damping valve V and inserting it into the cylinder 10, the hole 3b1 is also easily filled with liquid, so that gas is not left behind in the hole 3b1 and the laminated leaf valve 3 is repeatedly deflected, and the leftover gas does not escape from the hole 3b1 and enter the expansion-side chamber R1 and the compression-side chamber R2, which causes a disturbance in the damping force generated by the shock absorber D. Furthermore, since the hole 3b1 is not sealed but is connected to the expansion-side chamber R1 through the notched passage 3b2, and liquid can freely enter and exit the hole 3b1 when the laminated leaf valve 3 is deflected, excessive pressure build-up and pressure reduction do not occur in the hole 3b1, so that the laminated leaf valve 3 can smoothly perform a valve opening operation.

[0060] As described above, the damping valve V of this embodiment is a piston (valve seat member) 1 having a circular shape and a plurality of ports 1b, 1c arranged in a circumferential direction and seat portions 1d, 1e surrounding the outer circumferential sides of the ports 1b, 1c, and a laminated leaf valve 2 having an annular shape laminated on the piston (valve seat member) 1, with the inner circumferential side being a fixed end and the outer circumferential side being a free end that is allowed to bend and seat on and off the seat portions 1d, 1e, and opening and closing the ports 1b, 1c. , 3, and the stacked leaf valves 2, 3 have annular first leaf valves 2a, 3a and annular second leaf valves 2b, 3b superimposed on the anti-valve seat side which forms the back surface of the first leaf valves 2a, 3a, and the second leaf valves 2b, 3b have holes 2b1, 2b2, 3b1 axially opposed to the first leaf valves 2a, 3a, and cutout passages 2b3, 2b4, 3b2 which open from the outer periphery and communicate with the holes 2b1, 2b2, 3b1.

[0061] In the damping valve V configured in this manner, by providing the holes 2b1, 2b2, 3b1 in the second leaf valves 2b, 3b, it is possible to set flexible portions in the circumferential direction of the stacked leaf valves 2, 3, and the stacked leaf valves 2, 3 do not move away from the seat portions 1d, 1e all at once, but open from the flexible portions, thereby mitigating pressure fluctuations when the stacked leaf valves 2, 3 are opened, and it is possible to mitigate the generation of abnormal noise and sudden changes in damping force. And, according to the damping valve V configured in this manner, since the first leaf valves 2a, 3a and the second leaf valves 2b, 3b constituting the stacked leaf valves 2, 3 are both annular, the outer periphery of which is easy to grip with a chuck, and assembling is easier than with conventional damping valves including leaf valves having an outer diameter that is not annular, such as a D-shape, which is difficult to grip with a chuck. In addition, by adjusting the position, opening area and circumferential width of the holes 2b1, 2b2, 3b1 provided in the second leaf valves 2b, 3b, the position, flexibility and circumferential length of the flexible portions in the stacked leaf valves 2, 3 can be adjusted as desired, thereby improving the freedom of damping force characteristics.

[0062] Moreover, the second leaf valve 2 in the damping valve V of this embodiment has a pair of arms 2b5, 2b6 that face each other across the notched passage 2b3 on the outer circumferential side of the hole 2b1, and the radial lengths of the arms 2b5, 2b6 are different from each other. According to the damping valve V configured in this manner, the rigidity of the installation location of the hole 2b1 of the second leaf valve 2b can be set to be different in the circumferential direction, so that the flexibility of the laminated leaf valve 2 can be changed in the circumferential direction in the flexible portion, and the degree of freedom of the damping force characteristics can be further improved. Furthermore, in the second leaf valve 2 in the damping valve V of this embodiment, the notched passage 2b4 is communicated with a position offset from the center in the circumferential direction of the hole 2b2 to the circumferential end. Even in this manner, the rigidity of the installation location of the hole 2b2 of the second leaf valve 2b can be set to be different in the circumferential direction, so that the flexibility of the laminated leaf valve 2 can be changed in the circumferential direction in the flexible portion, and the degree of freedom of the damping force characteristics can be further improved.

[0063] In addition, according to the damping valve V, the holes 2b1, 2b2, 3b1 provided in the second leaf valves 2b, 3b are not sealed by the notched passages 2b3, 2b4, 3b2 opening from the outer periphery of the second leaf valves 2b, 3b and communicate with the outside of the stacked leaf valves 2, 3, so that gas is not left behind in the holes 2b1, 2b2, 3b1 and no disturbance is caused in the generated damping force. Furthermore, according to the damping valve V, liquid can freely flow in and out of the holes 2b1, 2b2, 3b1 when the ports 1b, 1c of the stacked leaf valves 2, 3 are opened and closed, so that excessive pressure is not trapped in the holes 2b1, 2b2, 3b1 and no pressure is reduced, so that the stacked leaf valves 2, 3 can smoothly open. In the illustrated example, the holes 2b1, 2b2, 3b1 are formed in an arc shape along the circumferential direction of the second leaf valves 2b, 3b, but they may be formed in a shape other than an arc shape.

[0064] Moreover, the stacked leaf valves 2, 3 in the damping valve V of this embodiment include third leaf valves 2c, 3c that are annular and have the same inner and outer diameters as the second leaf valves 2b, 3b and are stacked on the back side of the second leaf valves 2b, 3b. According to the damping valve V configured in this manner, the third leaf valves 2c, 3c having the same inner and outer diameters are stacked on the back side of the second leaf valves 2b, 3b, so that the overall rigidity of the stacked leaf valves 2, 3 is higher than that of the stacked leaf valves 2a, 3a and the second leaf valves 2b, 3b, and the generated damping force can be increased and the rigidity difference in the circumferential direction of the stacked leaf valves 2, 3 can be reduced, so that the difference in the amount of deflection of the stacked leaf valves 2, 3 in the initial valve opening period is reduced, and the stress during the valve opening operation and the change in the damping force in the initial valve opening period can be reduced.

[0065] Furthermore, like the damping valve V1 of the first modified example of this embodiment shown in Fig. 6, the stacked leaf valve 2 may include a fourth leaf valve 2d that is annular and has an outer diameter smaller than that of the second leaf valve 2b, and is stacked on the back side of the second leaf valve 2b facing parts of the holes 2b1, 2b2 as shown in Fig. 6. The outer diameter of the fourth leaf valve 2d is, specifically, as shown by a dashed line in Fig. 6, larger than the diameter of a circle C1 having the smallest diameter among circles tangent to the inner circumferences of the holes 2b1, 2b2 shown by a dashed line in Fig. 6 and smaller than the diameter of a circle C2 having the largest diameter among circles tangent to the outer circumferences of the holes 2b1, 2b2 shown by a dashed line in Fig. 6, and the outer periphery of the fourth leaf valve 2d overlaps parts of the holes 2b1, 2b2 when stacked on the second leaf valve 2b. With the damping valve V1 configured in this manner, compared to stacking a third leaf valve 2c having the same inner and outer diameters as the second leaf valve 2b on the back surface of the second leaf valve 2b, the overall rigidity of the stacked leaf valve 2 is lower and the outer peripheries of the first leaf valve 2a and the second leaf valve 2b that are not supported by the fourth leaf valve 2d are more likely to bend, so that the generated damping force can be lowered and the difference in circumferential rigidity of the stacked leaf valve 2 is greater, resulting in a larger difference in the amount of bending of the stacked leaf valves 2 in the circumferential direction at the beginning of the valve opening, and thus a larger change in damping force at the beginning of the valve opening.

[0066] Like the damping valve V2 of the second modified example of this embodiment shown in Fig. 7, the stacked leaf valve 2 may have a fifth leaf valve 2e that is annular and has an outer diameter smaller than that of the second leaf valve 2b and is stacked on the back side of the second leaf valve 2b without facing the holes 2b1, 2b2. The outer diameter of the fifth leaf valve 2e, specifically, as shown by a dashed line in Fig. 7, is smaller than the diameter of a circle C1 that has the smallest diameter among circles tangent to the inner circumferences of the holes 2b1, 2b2 shown by a dashed line in Fig. 7, and when the fifth leaf valve 2e is stacked on the second leaf valve 2b, its outer periphery does not overlap the holes 2b1, 2b2. With the damping valve V2 configured in this manner, compared to the case where a third leaf valve 2c having the same inner and outer diameters as the second leaf valve 2b is stacked on the back surface of the second leaf valve 2b, the overall rigidity of the stacked leaf valve 2 is further reduced and the outer circumferential portions of the first leaf valve 2a and the second leaf valve 2b that are not supported by the fifth leaf valve 2e are more likely to bend. As a result, the overall rigidity of the stacked leaf valve 2 is further reduced, and the generated damping force can be further reduced. At the same time, the difference in rigidity in the circumferential direction of the stacked leaf valve 2 is further increased, and the difference in the amount of deflection of the stacked leaf valve 2 in the circumferential direction at the initial stage of valve opening is further increased, thereby enabling a larger change in damping force at the initial stage of valve opening.

[0067] As can be understood from the above, the damping force characteristics can be tuned depending on the outer diameters of the third leaf valves 2c, 3c, fourth leaf valve 2d, and fifth leaf valve 2e stacked on the back side of the second leaf valve 2b, and the smaller the diameter of the leaf valves stacked on the back side of the second leaf valves 2b, 3b, the lower the rigidity of the stacked leaf valves 2, 3 and the lower the damping force. Therefore, the damping force characteristics of the damping valve V can be adjusted by setting the outer diameter of the leaf valves stacked on the back side of the second leaf valves 2b, 3b.

[0068] The shock absorber D of this embodiment includes a cylinder (outer tube) 10, a rod 11 inserted axially movably into the cylinder (outer tube) 10, a shock absorber body A having at least an extension-side chamber (operating chamber) R1 and a compression-side chamber (operating chamber) R2 through which liquid flows by the movement of the rod 11 relative to the cylinder (outer tube) 10, and a damping valve V provided between the extension-side chamber (operating chamber) R1 and the compression-side chamber (operating chamber) R2. The shock absorber D configured in this manner provides good assembly properties and improves the degree of freedom of the damping force characteristics.

[0069] In addition, in the example shown in Fig. 1, the two working chambers are the expansion-side chamber R1 and the compression-side chamber R2, and the expansion-side laminated leaf valve 2 and the compression-side laminated leaf valve 3 are provided above and below the piston 1 as the valve seat member in Fig. 1, but the laminated leaf valves may be provided only on the expansion-side chamber side or the compression-side chamber side of the piston 1. Also, in the case where the shock absorber D is a double-tube shock absorber having an outer shell as an outer tube on the outer periphery of the cylinder and a reservoir between the cylinder and the outer shell, a valve seat member and a laminated leaf valve may be provided between the compression-side chamber and the reservoir, and a damping valve V may be provided between the compression-side chamber and the reservoir.

[0070] Furthermore, as described above, both seat portions 1d and 1e are annular seat portions, but seat portions 1d and 1e may be petal-shaped seat portions that are connected to the outer periphery of annular inner seat portions 1f and 1g and independently surround each of ports 1b and 1c.

[0071] Although the preferred embodiment of the present invention has been described in detail above, modifications, variations and changes can be made without departing from the scope of the appended claims. [Explanation of symbols]

[0072] 1···Piston (valve seat member), 1b, 1c···Port, 1d, 1e···Seat portion, 2, 3···Stacked leaf valve, 2a, 3a···First leaf valve, 2b, 3b···Second leaf valve, 2b1, 2b2, 3b1···Hole, 2b3, 2b4, 3b2···Notched passage, arm···2b5, 2b6, 2b7, 2b8, 2c···Third leaf valve, 2d···Fourth leaf valve, 2e···Fifth leaf valve, 10···Cylinder (outer tube), 11···Rod, A···Shock absorber body, D···Shock absorber, V, V1, V2···Damping valve, R1···Extension side chamber (operating chamber), R2···Compression side chamber (operating chamber)

Claims

1. a valve seat member having a circular shape and including a plurality of ports arranged in a circumferential direction and a seat portion surrounding an outer circumferential side of the ports; a laminated leaf valve having an annular shape laminated on the valve seat member, the inner circumferential side being a fixed end and the outer circumferential side being a free end that is allowed to deform and moves to and from the seat portion for opening and closing the port, The laminated leaf valve includes a first leaf valve having an annular shape and a second leaf valve having an annular shape laminated on a side surface of the first leaf valve opposite to the valve seat, the side surface being a back surface of the first leaf valve, The second leaf valve has a hole axially facing the first leaf valve and a notched passage opening from an outer periphery and communicating with the hole. A damping valve characterized by:

2. The laminated leaf valve has a third leaf valve that is annular and is laminated on a rear side of the second leaf valve so as to close a hole of the second leaf valve.

2. The damping valve according to claim 1 .

3. The laminated leaf valve includes a fourth leaf valve that is annular and has an outer diameter smaller than that of the second leaf valve, and that faces a part of the hole and is laminated on a rear side of the second leaf valve.

2. The damping valve according to claim 1 .

4. The stacked leaf valve includes a fifth leaf valve that is annular and has an outer diameter smaller than that of the second leaf valve, and that is stacked on the back side of the second leaf valve without facing the hole.

2. The damping valve according to claim 1 .

5. the second leaf valve has a pair of arms facing each other across the notched passage on the outer circumferential side of the hole, The radial lengths of the arms are different from each other.

2. The damping valve according to claim 1 .

6. The notched passage communicates with a position shifted from the circumferential center of the hole toward the circumferential end.

2. The damping valve according to claim 1 .

7. a shock absorber body including an outer tube, a rod inserted into the outer tube so as to be movable in an axial direction, and at least two working chambers through which liquid flows in response to movement of the rod relative to the outer tube; and a damping valve according to any one of claims 1 to 6 provided between the working chambers. A shock absorber characterized by:

Images