Damping valves and shock absorbers

Abstract

To provide a damping valve which controls distribution of a spring load acting on a valve body to adjust damping force characteristics, and to provide a buffer including the damping valve.SOLUTION: A damping valve includes: an annular leaf valve 31 which is laminated on a valve disc 30 having multiple damping ports 30a arranged in a circumferential direction to open or close the damping ports 30a; and a spring member 40 which biases the leaf valve 31 to the valve disc 30 side. The spring member 40 has three or more coil springs 41 arranged along a circumferential direction of the leaf valve 31.SELECTED DRAWING: Figure 2

Description

[Technical field]

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

[0002] Conventionally, damping valves have been used in shock absorbers used in vehicle suspensions to suppress vehicle body vibrations by the damping force exerted when the shock absorber expands or contracts, thereby improving the ride comfort of the vehicle.

[0003] Specifically, the shock absorber includes a cylinder, a rod connected to a piston that is movably inserted into the cylinder and divides the inside of the cylinder into an extension side chamber and a compression side chamber, a tank, an extension side damping valve that exerts an extension side damping force by providing resistance to the flow of liquid from the extension side chamber to the compression side chamber during extension, and a compression side damping valve that separates the compression side chamber from the tank and exerts a compression side damping force by providing resistance to the flow of liquid from the compression side chamber to the tank during contraction (for example, Patent Document 1).

[0004] The compression side damping valve of Patent Document 1 includes a partition member that separates the compression side chamber from a tank and has a number of ports that connect the compression side chamber to the tank, an annular plate-shaped valve body that is stacked on the partition member and opens and closes the ports, a coil spring that urges the valve body toward the partition member, and an adjuster that adjusts the initial load of the coil spring.

[0005] Therefore, in the conventional valve structure, the initial load of the coil spring is adjusted to adjust the valve opening pressure of the compression damping valve, thereby making it possible to adjust the compression damping force of the shock absorber. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2002-227906 A Summary of the Invention [Problem to be solved by the invention]

[0007] As mentioned above, in the compression damping valve, the valve body is biased by a coil spring, but the spring load of the coil spring is not constant for each product and is biased in the circumferential direction, which causes unintended variations in the distribution of the spring load acting on the valve body in the circumferential direction. Therefore, in conventional damping valves, the timing at which the valve body opens varies in the circumferential direction, and there are cases where the desired damping force cannot be exerted.

[0008] Therefore, the present invention aims to provide a damping valve that can control the distribution of the spring load acting on the valve body, thereby eliminating unintended variations in the distribution of the spring load, and that can adjust the damping force characteristics, and a shock absorber equipped with this damping valve. [Means for solving the problem]

[0009] The means for solving the above problem includes a valve disk having a plurality of ports arranged in a circumferential direction, an annular valve body that is laminated on the valve disk and opens and closes the ports, and The valve body is abutted against the valve disc side. and a spring member for biasing the valve disc toward the valve disc, the spring member having three or more coil springs arranged along the circumferential direction of the valve body. The valve element is a leaf valve. According to this configuration, it is possible to control the distribution of the spring load of the spring member acting on the valve body in the circumferential direction.

[0010] In the damping valve of the present invention, the coil springs may have the same natural length and spring constant and be arranged at equal intervals in the circumferential direction. With this configuration, the spring load of the spring member acts evenly on the valve body in the circumferential direction, so that the timing at which the valve body opens does not vary in the circumferential direction. Therefore, a shock absorber equipped with the damping valve of the present invention can exert the desired damping force.

[0011] In the damping valve of the present invention, the natural length of at least one of the coil springs may be different from the natural length of the other coil springs, or the spring constant of at least one of the coil springs may be different from the spring constant of the other coil springs. With this configuration, the distribution of the spring load of the spring member can be intentionally biased, so that the opening manner of the valve body can be set arbitrarily. Therefore, the damping force characteristics of the shock absorber equipped with the damping valve of the present invention can be adjusted.

[0012] In the damping valve of the present invention, the spring member may have an annular holder having a plurality of accommodating portions for accommodating the coil springs. With this configuration, the coil springs can be automatically positioned at desired positions in the circumferential direction, and the assembly work of the spring member becomes easy.

[0013] The damping valve of the present invention may also include a cylindrical housing that accommodates the valve disc, the valve body, and the spring member and has a threaded portion on its inner circumference, a spring adjuster that is threadedly engaged with the threaded portion and rotates in the circumferential direction to displace in the axial direction relative to the housing and change the support position of the end of the spring member opposite the valve body in the axial direction, and a bearing that is interposed between the spring adjuster and the spring member and reduces friction between the spring adjuster and the spring member. With this configuration, even if the spring adjuster is rotated, the bearing slips and the rotational force of the spring adjuster is not easily transmitted to the spring member, so that it is possible to prevent the coil spring from twisting or the spring adjuster from rubbing against the spring member to cause contamination.

[0014] In the damping valve of the present invention, the housing may include a housing body and a cap having the screw portion that is screwed into the opening of the housing body and into which the spring adjuster is screwed, and a cylindrical spacer that houses the coil spring therein is interposed between one end of the cap and the valve disc, and the spacer may have a guide tube portion that regulates radial deflection of the coil spring. According to this configuration, the guide tube portion of the spacer faces the outside of each coil spring and suppresses radial deformation of each coil spring, thereby preventing the coil spring from bending outward when compressed.

[0015] The damping valve of the present invention in teeth, The spring member is The valve body may further include an annular spring support interposed between the valve body side end of each of the coil springs and the valve body. With this configuration, the end of the coil spring does not directly contact the back surface of the leaf valve, thereby preventing the leaf valve from being damaged.

[0016] In the damping valve of the present invention, the valve disc may have a plurality of valve seats each independently surrounding the outlet end of each of the ports. With this configuration, by arranging each coil spring so as to face each port, the valve opening pressure of each port can be set independently, making it easy to adjust the damping force characteristics of the shock absorber.

[0017] The shock absorber of the present invention includes a cylinder, a rod inserted into the cylinder so as to be freely movable in the axial direction, a shock absorber body having two working chambers through which liquid moves when the shock absorber expands or contracts, and the damping valve provided in the middle of a passage connecting the two working chambers. With this configuration, the damping characteristics of the damping force exerted when liquid moves between the two working chambers can be adjusted by the damping valve. Effect of the Invention

[0018] According to the damping valve and shock absorber of the present invention, the distribution of the spring load acting on the valve body can be controlled to adjust the damping force characteristics. [Brief description of the drawings]

[0019] [Figure 1] 1 is a cross-sectional view showing an entire shock absorber according to an embodiment of the present invention. [Diagram 2] 2 is an enlarged cross-sectional view showing a damping valve of the shock absorber according to the present embodiment. FIG. [Diagram 3] FIG. 2A is a cross-sectional view of a holder for a spring member according to the present embodiment, and FIG. 2B is a plan view of the holder for a spring member according to the present embodiment. [Figure 4] FIG. 3 is a cross-sectional view taken along line AA in FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will now be described with reference to the drawings, in which like reference numerals used throughout the several views indicate like or corresponding parts.

[0021] The damping valve V according to the present embodiment is used in a shock absorber D, which is used in a vehicle suspension. The shock absorber D including the damping valve V according to the present invention may of course be used in things other than vehicles, and may also be used in things other than shock absorbers. In this way, the purpose of use of the damping valve V according to the present invention can be changed as appropriate.

[0022] As shown in FIG. 1, the shock absorber D of this embodiment comprises a cylinder 1, a rod 2 inserted into the cylinder 1 so as to be freely movable in the axial direction, a piston 3 connected to the tip side of the rod 2 inserted into the cylinder 1 so as to be freely movable in the axial direction and dividing the inside of the cylinder 1 into an extension side chamber R1 and a compression side chamber R2, a shock absorber body 4 including a tank T having a reservoir chamber R connected to the compression side chamber R2, and a damping valve V provided in the middle of a passage communicating between the compression side chamber R2 and the reservoir chamber R.

[0023] Hereinafter, each part of the shock absorber D of this embodiment will be described in detail. As shown in Fig. 1, the cylinder 1 is cylindrical, and at the upper end of the cylinder 1 in the figure, an annular rod guide 5 that closes the upper end of the cylinder 1 and axially supports a rod 2 is provided. In addition, the lower end of the cylinder 1 is closed by a first bottom part 21 of a bottom member 20 described later.

[0024] As shown in FIG. 1, the rod 2 of this embodiment has a base end protruding from the upper end of the cylinder 1 in the figure, and a piston 3 is fixed to the outer periphery of the tip end by a piston nut 6. The piston 3 is inserted into the cylinder 1 so as to be freely movable in the axial direction, and divides the inside of the cylinder 1 into an expansion side chamber R1 and a compression side chamber R2. The piston 3 is provided with an expansion side passage 7 and a compression side passage 8 that communicate the expansion side chamber R1 and the compression side chamber R2. The expansion side passage 7 is provided with an expansion side valve 9 that allows only the passage of liquid from the expansion side chamber R1 to the compression side chamber R2 and provides resistance to the flow of this liquid. On the other hand, the compression side passage 8 is provided with a check valve 10 that allows only the passage of liquid from the compression side chamber R2 to the expansion side chamber R1. In this embodiment, the liquid is hydraulic oil, but the liquid may be other liquids such as water, an aqueous solution, an electrorheological fluid, or a magnetorheological fluid.

[0025] 1, an expansion-side bypass passage 11 that communicates between the expansion-side chamber R1 and the compression-side chamber R2 is formed in the rod 2, bypassing the expansion-side passage 7 and the compression-side passage 8. A variable throttle valve 12 that can adjust the flow path area of ​​the expansion-side bypass passage 11 is provided in the middle of the expansion-side bypass passage 11.

[0026] The tank T is cylindrical and is provided in parallel to the side of the cylinder 1 as shown in Fig. 1. An upper cap 13 that closes the upper end of the tank T is attached to the upper end of the tank T in Fig. 1. The lower end of the tank T in the figure is closed by a second bottom portion 22 of a bottom member 20 described below. Furthermore, a reservoir chamber R formed inside the tank T is partitioned into an air chamber G and a liquid chamber L facing the second bottom portion 22 by a free piston 14 slidably inserted into the tank T, and the volumes of the air chamber G and the liquid chamber L expand and contract when the free piston 14 moves.

[0027] Next, a detailed description will be given of the bottom member 20. As shown in Fig. 1, the bottom member 20 of this embodiment includes a first bottom portion 21 that closes the lower end of the cylinder 1, a second bottom portion 22 that closes the lower end of the tank T, and a connecting portion 23 that connects the first bottom portion 21 and the second bottom portion 22.

[0028] 1, the first bottom part 21 includes a bottom body 21a having a bottomed cylindrical shape and a screw part (not shown) on the outer periphery of the upper end, and a stopper 21b protruding from near the center of the bottom body 21a toward the opposite side to the connecting part. Then, when the screw part of the bottom body 21a is screwed into the inner periphery of the lower end of the cylinder 1 and the cylinder 1 is screwed in until the lower end of the cylinder 1 abuts against the stopper 21b, the first bottom part 21 is attached to the lower end of the cylinder 1, and the lower end of the cylinder 1 is closed by the first bottom part 21.

[0029] 1, the second bottom portion 22 has a housing main body 24 that is tubular with a bottom and is arranged horizontally in the figure so that its bottom faces the first bottom portion 21, and accommodates a damping portion V1 of a damping valve V described later inside, and a cylindrical mounting portion 25 that extends from a side portion of the housing main body 24 toward the upper side in the figure. A screw portion (not shown) is provided on the outer periphery of the mounting portion 25. Then, when the inner periphery of the lower end of the tank T is screwed into the screw portion of the mounting portion 25 and the tank T is screwed in until the lower end abuts against the housing main body 22a, the second bottom portion 22 is attached to the lower end of the tank T, and the lower end of the tank T is closed by the second bottom portion 22.

[0030] The inner circumference of the housing body 24 is formed to have a circular cross section. The inner diameter of the housing body 24 is smaller on the bottom side than on the opening side, and the inner circumference of the housing body 24 is formed with a small diameter section 24a on the bottom side and a large diameter section 24b on the opening side, with a step section 24c formed at the boundary between the small diameter section 24a and the large diameter section 24b. Furthermore, a screw section 24d is provided at the opening side end of the large diameter section 24b.

[0031] In addition, on the upper side of the side portion of the housing body 24 facing the liquid chamber L of the tank T in FIG. 1, a communication hole 26 is provided that penetrates the large diameter portion 24b of the housing body 24 and connects the interior of the housing body 24 to the liquid chamber L of the reservoir chamber R.

[0032] 1, the connecting portion 23 connects a side portion of the bottom body 21a of the first bottom portion 21 and a bottom portion of the housing body 24 of the second bottom portion 22, and has a communication passage 23a that communicates between the inside of the first bottom portion 21 and the inside of the housing body 24. Therefore, the pressure side chamber R2 and the liquid chamber L of the reservoir chamber R are communicated with the inside of the first bottom portion 21, the communication passage 23a of the connecting portion 23, the inside of the housing body 24, and the communication hole 26.

[0033] Next, the damping valve V of this embodiment will be described in detail. The damping valve V of this embodiment includes the housing H including the housing main body 24 described above, and a damping section V1 housed in the housing H. The damping section V1 of this embodiment includes a damping passage P1 that provides resistance to the flow of liquid from the compression side chamber R2 to the reservoir chamber R, a suction passage P2 that allows only the passage of liquid from the reservoir chamber R to the compression side chamber R2, and a compression side bypass passage P3 that communicates between the compression side chamber R2 and the reservoir chamber R and has a variable orifice O that provides resistance to the flow of liquid passing through.

[0034] Hereinafter, each component of the damping valve V of this embodiment will be described in detail. As shown in Fig. 1 and Fig. 2, the housing H of this embodiment is composed of the above-mentioned housing body 24 and a cap 27 screwed to the screw part 24d provided at the opening side end of the large diameter part 24b of the housing body 24. As shown in Fig. 2, the cap 27 has a large diameter cylindrical part 27a inserted into the inside of the housing body 24 and screwed to the screw part 24d at its outer periphery, a medium diameter cylindrical part 27b continuous with the base end side (right side in the figure) of the large diameter cylindrical part 27a, which is formed with inner and outer diameters smaller than the large diameter cylindrical part 27a and has a screw part 27d on its inner periphery, and a small diameter cylindrical part 27c continuous with the side opposite to the large diameter cylindrical part (right side in the figure) of the medium diameter cylindrical part 27b and which is formed with an inner diameter smaller than that of the medium diameter cylindrical part 27b.

[0035] 2, a seal ring S1 is attached to the outer periphery of the large diameter cylindrical portion 27a of cap 27, and a seal is formed between the large diameter cylindrical portion 27a and the housing main body 24. The outer periphery of the small diameter cylindrical portion 27c is hexagonal, making it easy to grasp cap 27 with a tool or the like when screwing cap 27 into the threaded portion 24d of the housing main body 24. The shape of cap 27 in this embodiment is merely an example and can be modified as appropriate.

[0036] As shown in FIG. 2, the damping section V1 of this embodiment includes a valve disc 30 having a plurality of damping ports 30a arranged in the circumferential direction in an annular shape, a leaf valve 31 as an annular valve body stacked on the valve disc 30 for opening and closing the damping port 30a, a spring member 40 for biasing the leaf valve 31 toward the valve disc 30, and a spring adjuster 50 for adjusting the initial load of the spring member 40.

[0037] Specifically, as shown in FIG. 2, the valve disc 30 is annular, and its outer peripheral end is laminated on the step portion 24c of the housing body 24 via a spacer ring 32, dividing the inside of the housing body 24 into two chambers, a chamber on the compression side chamber R2 side and a chamber on the reservoir chamber R side. A seal ring S2 that slides against the inner circumference of the housing body 24 is attached to the outer circumference of the valve disc 30, and the gap between the outer circumference of the valve disc 30 and the large diameter portion 24b of the housing body 24 is sealed. In addition, the valve disc 30 is formed with damping ports 30a and suction ports 30b that communicate with the compression side chamber R2 and the reservoir chamber R, and are alternately arranged in the circumferential direction. The positions and numbers of the damping ports 30a and suction ports 30b are not particularly limited and can be changed as appropriate.

[0038] In addition, a plurality of petal-shaped valve seats 30c are formed on the reservoir chamber R side (right side in FIG. 2) of the valve disc 30, each independently surrounding the outlet end (right end in FIG. 2) of each damping port 30a. Therefore, the damping port 30a in this embodiment is a so-called independent port. On the other hand, an annular inner valve seat 30d surrounding the inlet end (left end in FIG. 2) of each damping port 30a and an annular outer valve seat 30e surrounding the outlet end of each suction port 30b are formed on the compression side chamber R2 side (left side in FIG. 2) of the valve disc 30. In this embodiment, the valve seat 30c is petal-shaped, but it may be an annular type surrounding the outlet end of each damping port 30a.

[0039] As shown in FIG. 2, on the compression side chamber R2 side of the valve disc 30, there are provided a spring receiving member 34 having a tubular portion 34a that abuts against the inner peripheral end of the valve disc 30 and a ring-shaped spring receiving portion 34b that protrudes outward from the anti-valve disc end of the tubular portion 34a, an annular plate 35 that is slidably inserted onto the outer periphery of the tubular portion 34a of the spring receiving member 34 and closes the outlet end (left end in FIG. 2) of the suction port 30b, and a biasing spring 36 that is interposed between the spring receiving portion 34b of the spring receiving member 34 and the annular plate 35 and biases the annular plate 35 toward the valve disc 30 side.

[0040] When liquid moves from the reservoir chamber R to the compression side chamber R2, the annular plate 35 lifts from the valve disc 30 against the biasing force of the biasing spring 36 to open the valve. Conversely, when liquid moves from the compression side chamber R2 to the reservoir chamber R, the annular plate 35 is pressed against the valve disc 30 by the pressure of the liquid, so that it seats on the outer valve seat 30e and remains closed.

[0041] Therefore, the spring receiving member 34, the annular plate 35, and the biasing spring 36 constitute a check valve 37 that allows only the flow of liquid moving from the reservoir chamber R to the compression side chamber R2. Thus, the suction port 30b functions as a suction passage P2 that allows only the passage of liquid from the reservoir chamber R to the compression side chamber R2 by the check valve 37. In addition, as shown in FIG. 2, the annular plate 35 is provided with a hole 35a at a position facing the damping port 30a, so that the inlet end of the damping port 30a is not blocked by the annular plate 35.

[0042] In this embodiment, members such as a valve disc 30, a leaf valve 31, and a check valve 37 are integrally attached to the outer periphery of a mounting shaft 38 with a nut N to form a valve assembly VA.

[0043] Specifically, as shown in FIG. 2, the mounting shaft 38 has a shaft body 38a, a screw groove 38b provided on the outer periphery of one end of the shaft body 38a, a sliding portion 38c provided on the outer periphery of the other end of the shaft body 38a and having an outer diameter larger than that of the shaft body 38a, a flange portion 38d provided on the outer periphery of the sliding portion 38c side of the shaft body 38a, and a through hole 38e that penetrates the shaft body 38a in the axial direction.

[0044] Then, an annular adjustment member 39, spacer 33, leaf valve 31, valve disc 30, and check valve 37, which will be described later, are stacked in this order on flange portion 38d of the mounting shaft 38, and a nut N is screwed into threaded groove 38b provided on the outer periphery of one end of the shaft body 38a and tightened, so that these components are clamped between flange portion 38d and nut N and assembled integrally to the mounting shaft 38.

[0045] Returning to the previous section, as shown in Fig. 2, on the reservoir chamber R side of the valve disc 30, a leaf valve 31 configured by laminating a plurality of annular plates is stacked as a valve body that closes the outlet end of the damping port 30a. Also, a spacer 33 that supports the inner periphery of the leaf valve 31 is stacked on the inner periphery of the leaf valve 31 on the side opposite the valve disc, and determines the bending fulcrum of the leaf valve 31. The number of annular plates in the leaf valve 31 can be changed as desired, and the bending rigidity of the leaf valve 31 can be adjusted depending on the number of annular plates.

[0046] According to this configuration, when liquid moves from the pressure-side chamber R2 to the reservoir chamber R, if the pressure of the liquid acting on the leaf valve 31 from the inlet side of the damping port 30a exceeds the valve-opening pressure of the leaf valve 31, the leaf valve 31 bends with the outer circumferential end of the spacer 33 as a fulcrum, moving the outer periphery away from the valve seat 30c to open, and provides resistance to the flow of liquid passing through the damping port 30a according to the size of the gap between the outer periphery of the leaf valve 31 and the valve seat 30c. At this time, the leaf valve 31 is biased toward the valve disc 30 by the spring member 40 described later, so that the valve-opening pressure of the leaf valve 31 is determined by the rigidity of the leaf valve 31 and the spring load of the spring member 40. On the other hand, when liquid moves from the reservoir chamber R to the pressure-side chamber R2, the leaf valve 31 is pressed against the valve disc 30 by the pressure of the liquid and seats on the valve seat 30c to close the damping port 30a.

[0047] Therefore, the leaf valve 31 and the spring member 40 function as a valve that allows only the flow of liquid moving from the compression side chamber R2 to the reservoir chamber R and provides resistance to this flow of liquid, and therefore the leaf valve 31 and the spring member 40, together with the damping port 30a, form a damping passage P1.

[0048] In this embodiment, the inlet end (right end in FIG. 2) of the suction port 30b is opened between adjacent valve seats 30c, 30c formed on the reservoir chamber R side of the valve disc 30, so that the suction port 30b communicates with the chamber on the reservoir chamber R side in the housing main body 24 through the gap formed between the adjacent valve seats 30c, 30c. In other words, the leaf valve 31 of this embodiment is configured not to close the inlet end of the suction port 30b. The leaf valve 31 is not limited to one that is fixed to the inner periphery and opens by bending the outer periphery, and may be, for example, one that is stacked on the valve disc 30 so as to be movable toward and away from the valve disc 30 and that is lifted as a whole from the valve disc 30 by receiving the pressure of the compression side chamber R2.

[0049] 2, the above-mentioned adjustment member 39 is composed of an annular guide member 39a that abuts against the spacer 33, an annular spacer 39b that abuts against the flange portion 38d, and a plurality of adjustment shims 39c interposed between the guide member 39a and the spacer 39b. With this configuration, even if the number of annular plates in the leaf valve 31 is changed to adjust the flexural rigidity of the leaf valve 31 and the axial distance from the spacer 33 to the flange portion 38d changes, the axial length of the adjustment member 39 can be adjusted to the axial distance from the spacer 33 to the flange portion 38d by changing the number of adjustment shims 39c.

[0050] Next, the spring member 40 will be described in detail. As shown in Fig. 2, the spring member 40 is interposed between the back side of the leaf valve 31 and a spring adjuster 50 described later, and biases the leaf valve 31 toward the valve disc 30. Specifically, as shown in Fig. 2, the spring member 40 of this embodiment includes six coil springs 41 arranged along the circumferential direction of the leaf valve 31, and a holder 42 having six accommodation portions 43 that accommodate the coil springs 41.

[0051] As shown in Figures 3(A) and (B), the holder 42 of this embodiment comprises an annular seat portion 44 having an opening hole 44a in the center, and a retaining portion 45 that rises from the seat portion 44 to surround the opening hole 44a and holds one end of each coil spring 41.

[0052] 3A, the seat portion 44 is disk-shaped and has an opening 44a at its center. The inner peripheral surface of the opening 44a is provided with a tapered surface 44b that gradually increases in diameter as it moves away from the opening on the holding portion 45 side.

[0053] As shown in FIG. 3B, the holding portion 45 is annular and has six circular recesses 45a into which the coil spring 41 is fitted. As shown in FIG. 3A, the inner periphery of the left end of the holding portion 45 is chamfered to facilitate fitting the coil spring 41 into the recesses 45a. In this embodiment, the recesses 45a and the seat portion 44 form the accommodation portion 43. When one end of the coil spring is fitted into the recesses 45a, the one end of the coil spring 41 is seated on the seat portion 44 while being held by the holding portion 45, and therefore the one end of the coil spring 41 is accommodated in the accommodation portion 43.

[0054] In this way, when the coil spring 41 is held by the holder 42, the coil spring 41 can be automatically positioned at a desired position in the circumferential direction, and the assembly work of the spring member 40 becomes easy. Note that the structure of the holder 42 described above is one example, and is not limited to the configuration of this embodiment. For example, the holding portion 45 may be a plurality of cylinders arranged in the circumferential direction on the seat portion 44, and the coil spring 41 may be housed in the cylinders.

[0055] Each coil spring 41 in this embodiment has the same natural length and spring constant, and is held and housed in each housing portion 43 of holder 42. As described above, the housing portions 43 in this embodiment are arranged at equal intervals in the circumferential direction, and therefore, in spring member 40 of this embodiment, identical coil springs 41 are arranged at equal intervals in the circumferential direction.

[0056] Therefore, the spring member 40 of the present embodiment biases the leaf valve 31 toward the valve disc 30 by six identical coil springs 41 arranged at equal intervals along the circumferential direction of the leaf valve 31. Therefore, the spring member 40 can apply a spring load evenly to six points on the back surface of the leaf valve 31.

[0057] In this way, when the spring load of the spring member 40 acts evenly in the circumferential direction on the leaf valve 31, the valve opening pressures of the portions of the leaf valve 31 facing each damping port 30a become equal, and when the liquid moves from the compression side chamber R2 to the reservoir chamber R during contraction of the shock absorber D, the leaf valves 31 open almost simultaneously in the circumferential direction. Therefore, the damping valve V of this embodiment can exert a targeted damping force against the flow of liquid passing through the damping passage P1.

[0058] In addition, in this embodiment, the natural length and spring constant of each coil spring 41 are made the same and the coil springs 41 are arranged at equal intervals in the circumferential direction so that the leaf valves 31 open almost simultaneously in the circumferential direction. However, the natural length and / or spring constant of at least one of the coil springs 41 may be set to be different from those of the other coil springs 41.

[0059] Here, the spring load of the coil spring 41 is a value obtained by multiplying the amount of deformation from the natural length by the spring constant. Therefore, if the compressed length of the coil spring 41 does not change, changing at least one of the natural length or the spring constant of the coil spring 41 will also change the spring load of the coil spring 41.

[0060] Furthermore, since each coil spring 41 is compressed so that the compressed length is the same, by changing the natural length and / or spring constant of each coil spring 41, the spring load of each coil spring 41 arranged circumferentially around the leaf valve 31 can be set to any value.

[0061] Therefore, when at least one of the coil springs 41 has a different natural length and / or spring constant from the other coil springs 41, the distribution of the spring load of the spring member 40 can be intentionally biased. In this case, the leaf valves 31 open in order from the portion where the spring load acting in the circumferential direction is smallest. Therefore, when the distribution of the spring load of the spring member 40 is intentionally biased in this way, the opening manner of the leaf valves 31 can be set arbitrarily, and therefore the damping force characteristics of the shock absorber D can be adjusted.

[0062] Specifically, for example, six coil springs 41 are divided into two types of coil springs 41 with different spring loads, and the different types of coil springs 41 are arranged alternately at equal intervals in the circumferential direction. In this way, the load of the coil spring 41 with the smaller spring load and the load of the coil spring 41 with the larger spring load act evenly on the leaf valve 31 in the circumferential direction, so that the leaf valve 31 opens gradually and evenly in the circumferential direction. Therefore, the damping force characteristic of the shock absorber D can be a linear characteristic. As another example, the leaf valve 31 is divided in half as viewed in the axial direction, and a coil spring 41 with a smaller spring load is arranged on one side, and a coil spring 41 with a larger spring load is arranged on the other side. In this way, the leaf valve 31 opens on one side before opening on the other side, so that the pressure loss characteristic of the leaf valve 31 with respect to the liquid passing through the damping passage P1 changes midway. Therefore, the damping force characteristic of the shock absorber D can be a nonlinear characteristic.

[0063] In the spring member 40 of the present embodiment, the coil springs 41 are arranged at equal intervals in the circumferential direction, but the coil springs 41 may be arranged at any circumferential position. In this way, the distribution of the spring load of the spring member 40 can be intentionally biased between the portion in the circumferential direction of the leaf valve 31 where the coil springs 41 are arranged and the portion where they are not arranged.

[0064] As mentioned above, by intentionally biasing the distribution of the spring load of the spring member 40, the opening manner of the leaf valve 31 can be set arbitrarily, so that the damping force characteristics of the shock absorber D can be adjusted even by changing the circumferential position of each coil spring 41.

[0065] In addition, the damping force characteristics of the shock absorber D may be set by changing at least one of the natural length and the spring constant of each coil spring 41, and both the circumferential position of each coil spring 41.

[0066] In this embodiment, the spring member 40 has six coil springs 41, but the number of coil springs 41 may be three or more. Also, it is not necessary to accommodate coil springs 41 in all of the accommodation portions 43 of the holder 42. For example, three coil springs 41 may be accommodated in a holder 42 having six accommodation portions 43. Therefore, the number of accommodation portions 43 may be equal to or greater than the number of coil springs 41.

[0067] Returning to FIG. 2, an annular spring retainer 46 is interposed between the other end of the coil spring 41 and the leaf valve 31, and prevents the other end of the coil spring 41 from directly abutting the back surface of the leaf valve 31 and damaging the leaf valve 31.

[0068] 2, the spring receiver 46 of this embodiment is slidably attached to the outer periphery of a guide member 39a which is assembled to the outer periphery of the mounting shaft 38. The guide member 39a guides the axial movement of the spring receiver 46 when the leaf valve 31 opens and the spring receiver 46 is pushed up by the leaf valve 31. The guide member 39a of this embodiment is made of a single member and has a smooth outer periphery. Therefore, no rattling occurs when the spring receiver 46 moves axially along the guide member 39a as the leaf valve 31 opens.

[0069] 2, an annular step 27e is provided on the inner periphery on the tip side of the large diameter cylindrical portion 27a of the cap 27 in the housing H, and a cylindrical spacer 47 is interposed between the step 27e of the cap 27 and the valve disc 30. Specifically, the spacer 47 has a valve disc side cylindrical portion 47a that abuts against the valve disc 30, and a guide cylindrical portion 47b that abuts against the cap 27 and has an inner diameter smaller than that of the valve disc side cylindrical portion 47a.

[0070] The valve disc side cylindrical portion 47a is provided with a plurality of radial holes 47c that penetrate radially and communicate with the reservoir chamber R via the communication holes 26 of the housing body 24. In addition, the guide cylindrical portion 47b faces the outside of each coil spring 41 and suppresses radial deformation of each coil spring 41. As a result, the guide cylindrical portion 47b prevents each coil spring 41 from bending outward when compressed.

[0071] Next, the spring adjuster 50 will be described in detail. As shown in Fig. 2, the spring adjuster 50 of this embodiment includes a cylindrical adjuster body 51 that is screwed into the screw portion 27d of the cap 27 to support the end of the spring member 40 opposite the leaf valve, and a bottomed cylindrical case 52 that is provided at the tip (left end in the figure) of the adjuster body 51 and disposed inside the spring member 40. With this configuration, when the spring adjuster 50 is rotated in the circumferential direction, the spring adjuster 50 is displaced in the axial direction in the manner of a feed screw, so that the support position of the end of the spring member 40 opposite the leaf valve can be changed in the axial direction to adjust the initial load of the spring member 40. Therefore, by adjusting the initial load of the spring adjuster 50, the spring adjuster 50 can adjust the valve opening pressure of the leaf valve 31 that is biased by the spring member 40 toward the valve disc 30, and can adjust the flow resistance of the damping passage P1.

[0072] 2, the adjuster body 51 is generally cylindrical and includes a support portion 51a inserted axially movably into the large-diameter cylinder portion 27a of the cap 27 to support the end of the spring member 40 on the opposite side to the leaf valve, a screw portion 51b continuous with the end of the support portion 51a on the opposite side to the spring member, formed with an outer diameter smaller than that of the support portion 51a, and screwed on its outer periphery to the screw portion 27d of the medium-diameter cylinder portion 27b of the cap 27, and a sliding portion 51c continuous with the end of the screw portion 51b on the opposite side to the support portion and slidably inserted into the inner periphery of the small-diameter cylinder portion 27c of the cap 27. A cylindrical connecting cylinder portion 51d having an outer diameter smaller than that of the support portion 51a and having a plurality of communication ports 51e penetrating in the radial direction is provided on the inner periphery of the support portion 51a on the spring member 40 side.

[0073] 2, a washer 53 is interposed between the support portion 51a and the end of the spring member 40 on the side opposite the leaf valve, as a bearing to reduce friction generated between the support portion 51a and the spring member 40. In this way, even if the spring adjuster 50 is rotated, the washer 53 slips, making it difficult for the rotational force of the spring adjuster 50 to be transmitted to the spring member 40, preventing the coil spring 41 from twisting and the support portion 51a from rubbing against the spring member 40 to cause contamination.

[0074] Furthermore, a head 51f having a hexagonal outer periphery is provided at the end of sliding portion 51c opposite the screw-engagement portion. Therefore, by gripping the outer periphery of head 51f with a tool, spring adjuster 50 can be rotated relative to cap 27. Also, a seal ring S3 is attached to the inner periphery of small diameter cylindrical portion 27c of cap 27, and a seal is formed between the inner periphery of small diameter cylindrical portion 27c and the outer periphery of sliding portion 51c.

[0075] 2, the case 52 is a cylinder with a bottom, with a bottom 52a connected to the opposite side of the support portion of the connecting cylinder portion 51d, and the outer diameter of the case 52 is equal to the outer diameter of the connecting cylinder portion 51d. In addition, a hole 52b is provided in the center of the bottom 52a of the case 52, penetrating the thickness of the bottom 52a.

[0076] 2, since case 52 is disposed inside spring member 40, the outer periphery of case 52 faces the inner side of each coil spring 41 constituting spring member 40. Therefore, case 52 can suppress radial deformation of each coil spring 41 at the outer periphery, and prevent each coil spring 41 from bending inward.

[0077] In addition, since the outer diameter of the case 52 is set to be smaller than the opening hole 44a of the holder 42 of the spring member 40, a gap is formed between the case 52 and the holder 42. In this embodiment, no flow path resistance is generated when the liquid passes through the gap. However, resistance may be applied to the flow of the liquid passing through the gap.

[0078] 2, the sliding portion 38c of the mounting shaft 38 is slidably inserted inside the case 52. Therefore, when the spring adjuster 50 is rotated to move axially relative to the cap 27, the case 52 moves while sliding against the outer periphery of the sliding portion 38c. At this time, the through hole 38e provided in the shaft body 38a of the mounting shaft 38 opens at a position opposite to the hole 52b provided in the bottom portion 52a of the case 52, so that the through hole 38e and the hole 52b always communicate with each other even when the case 52 moves axially. In addition, a seal ring S4 is attached to the outer periphery of the sliding portion 38c, and the gap between the outer periphery of the sliding portion 38c and the inner periphery of the case 52 is sealed.

[0079] Therefore, in this embodiment, the through hole 38e, the hole 52b, the communication port 51e, and the gap formed between the case 52 and the holder 42 form a compression side bypass passage P3 that bypasses the damping passage P1 and connects the compression side chamber R2 to the reservoir chamber R.

[0080] 2, a needle adjuster 60 capable of adjusting the flow path area of ​​hole 52b is axially movably attached to the inner periphery of adjuster body 51 of spring adjuster 50. In detail, needle adjuster 60 of the present embodiment includes a needle shaft 60c having a shaft portion 60b having a needle portion 60a formed at its tip to be inserted into hole 52b, a screw shaft 60d continuing from the base end of needle shaft 60c and screwed into screw portion 51g formed on the inner periphery of screw-fitting portion 51b, and a base end shaft 60e continuing from the anti-needle shaft side of screw shaft 60d and slidably inserted into the inner periphery of sliding portion 51c.

[0081] According to this configuration, when the needle adjuster 60 is rotated in the circumferential direction, the needle adjuster 60 is displaced in the axial direction in the manner of a feed screw, so that the insertion amount of the needle portion 60a into the hole 52b changes, and the flow path area of ​​the hole 52b also changes.

[0082] Therefore, in this embodiment, the hole 52b and the needle portion 60a constitute a variable orifice O. Therefore, by adjusting the axial position of the needle adjuster 60, the flow path area of ​​the hole 52b is adjusted, and the flow path resistance of the variable orifice O can be adjusted.

[0083] In addition, the base end shaft 60e has a hexagonal hole that opens from the side opposite the needle shaft, so that if a tool such as a hexagonal wrench is inserted into this hexagonal hole, the needle adjuster 60 can be rotated using the tool. Furthermore, a seal ring S5 is attached to the outer periphery of the base end shaft 60e, so that a seal is formed between the outer periphery of the base end shaft 60e and the inner periphery of the sliding portion 51c of the spring adjuster 50. In addition, a C-ring 60f is attached to the inner periphery of the sliding portion 51c on the head 51f side, and the needle adjuster 60 is prevented from coming off by the C-ring 60f.

[0084] The configurations of the spring adjuster 50 and the needle adjuster 60 described above are merely examples, and the present invention is not limited to the above configurations and can be modified as appropriate.

[0085] In this embodiment, as shown in Figures 2 and 4, a pair of accommodating holes 70, 70 that penetrate radially and face each other are formed in the support portion 51a of the spring adjuster 50, and each accommodating hole 70 accommodates a pair of balls 71, 72 and a biasing spring 73 interposed between the pair of balls 71, 72.

[0086] Here, a plurality of first grooves 27f are formed along the axial direction and arranged at predetermined intervals in the circumferential direction on the inner periphery of the large diameter cylindrical portion 27a of the cap 27, as shown in Fig. 4. Furthermore, a plurality of second grooves 60g are formed along the axial direction and arranged at predetermined intervals in the circumferential direction on the outer periphery of the shaft portion 60b of the needle shaft 60c, as shown in Fig. 4. Each of these first grooves 27f and each of the second grooves 60g are formed to have a U-shaped cross section.

[0087] Each of the accommodating holes 70 faces the inner circumference of the large diameter cylindrical portion 27a of the cap 27 and the outer circumference of the shaft portion 60b of the needle shaft 60c. Therefore, as shown in Fig. 4, the pair of balls 71, 72 accommodated in each of the accommodating holes 70 are urged by a biasing spring 73 toward the inner circumference of the large diameter cylindrical portion 27a of the cap 27 and the outer circumference of the shaft portion 60b of the needle adjuster 60. When the spring adjuster 50 is rotated in the circumferential direction relative to the cap 27 with the outer ball 71 in the figure inserted into the first groove 27f, the biasing spring 73 is compressed and exerts a resistance force that prevents the spring adjuster 50 from rotating, and the outer ball 71 accommodated in each of the accommodating holes 70 tries to hold the spring adjuster 50 at a position where it is fitted into the first groove 27f, thereby suppressing the relative rotation of the cap 27 and the spring adjuster 50 in the circumferential direction. Therefore, the spring adjuster 50 is positioned in the circumferential direction with respect to the cap 27 at a position where the outer ball 71 is fitted into the first groove 27f. Although the number of first grooves 27f is not particularly limited, increasing the number of first grooves 27f allows for finer adjustment of the initial load of the spring member 40.

[0088] On the other hand, when the needle adjuster 60 is rotated in the circumferential direction relative to the spring adjuster 50 with the inner ball 72 in the figure inserted into the second groove 60g, the biasing spring 73 is compressed and exerts a resistance force that prevents the needle adjuster 60 from rotating, and the inner balls 72 housed in each housing hole 70 attempt to hold the spring adjuster 50 in a position where they are fitted into the second groove 60g, thereby suppressing relative rotation in the circumferential direction between the spring adjuster 50 and the needle adjuster 60. Thus, the needle adjuster 60 is positioned in the circumferential direction relative to the spring adjuster 50 at a position where the inner balls 72 are fitted into the second groove 60g. Note that the number of second grooves 60g is not particularly limited, but increasing the number of second grooves 60g allows for finer adjustment of the flow resistance of the variable orifice O accordingly.

[0089] As described above, in the present embodiment, a detent mechanism for positioning the spring adjuster 50 and the needle adjuster 60 in the circumferential direction is constituted by the pair of balls 71, 72 and biasing spring 73 housed in the housing hole 70 of the spring adjuster 50, the first groove 27f formed on the inner circumference of the cap 27, and the second groove 60g formed on the outer circumference of the needle adjuster 60. Note that the detent mechanism is just one example and may be constructed in a different structure, but when constructed in the structure of the present embodiment, it is possible to position the spring adjuster 50 in the circumferential direction relative to the cap 27, while positioning the needle adjuster 60 in the circumferential direction relative to the spring adjuster 50.

[0090] Next, a description will be given of a procedure for assembling the damping portion V1 to the housing H. First, the spacer ring 32 and the valve assembly VA are inserted from the opening side of the housing body 24 until the spacer ring 32 abuts against the step portion 24c of the housing body 24.

[0091] Next, the spacer 47 is inserted into the housing body 24 after being brought into contact with the outer periphery of the valve disc 30 , and the spring bearing 46 is laminated on the back side of the leaf valve 31 .

[0092] Then, the spring member 40, the spring adjuster 50 and the needle adjuster 60 are assembled in the cap 27, and the cap 27 is screwed onto the threaded portion 24d of the housing body until the spacer 47 abuts against a step 27e formed on the inner circumference of the tip of the cap 27. Then, the damping portion V1 is sandwiched between the housing body 24 and the cap 27 and assembled to the housing H. As shown in FIG. 2, the large diameter cylindrical portion 27a of the cap 27 has a hole 27g that penetrates radially between a screw groove (not shown) that is screwed onto the threaded portion 24d of the housing body 24 and the seal ring S1. This hole 27g is an air vent hole when the cap 27 is screwed into the housing body 24, and is closed by the large diameter portion 24b of the housing body 24 in the assembled state.

[0093] The reservoir chamber R side ends of the damping passage P1, the suction passage P2 and the compression side bypass passage P3 of the damping section V1 assembled to the housing H in this manner are each connected to the reservoir chamber R via the space that houses the spacer 47 and the spring member 40 inside the cap 27, and the radial hole 47c formed in the spacer 47, as shown in Figure 2.

[0094] Next, the operation of the shock absorber D of this embodiment will be described. First, a case will be described in which the expansion / contraction speed of the shock absorber D is in the extremely low speed range and the pressure in the expansion-side chamber R1 or the compression-side chamber R2 is lower than the valve opening pressure of the expansion-side valve 9 or the leaf valve 31 provided in the damping passage P1.

[0095] When the shock absorber D is expanded, the liquid in the expansion-side chamber R1 being compressed moves to the expansion-side chamber R2 through the expansion-side bypass passage 11, and the rod 2 is withdrawn from the cylinder 1, so that the liquid in the cylinder 1 is insufficient for the volume of the rod 2 withdrawn. Therefore, the check valve 37 opens and the shortage of liquid is supplied from the reservoir chamber R to the cylinder 1 through the suction passage P2 of the damping valve V. Therefore, during expansion in the very low speed range, an expansion-side damping force based on the resistance of the variable throttle valve 12 provided in the middle of the expansion-side bypass passage 11 is exerted.

[0096] Conversely, when the shock absorber D contracts, the liquid in the compression side chamber R2 being compressed moves into the expansion side chamber R1 via the compression side passage 8, and the rod 2 enters the cylinder 1, so that the liquid in the cylinder 1 corresponds to the volume of the rod 2 entering. The excess liquid is discharged from the compression side chamber R2 to the reservoir chamber R through the compression side bypass passage P3 of the damping valve V, because the leaf valve 31 does not open and the damping passage P1 is blocked. Therefore, during contraction in the extremely low speed range, a compression side damping force is exerted based on the flow resistance of the variable orifice O provided in the middle of the compression side bypass passage P3.

[0097] Next, a case will be described where the expansion / contraction speed of the shock absorber D is equal to or higher than the low speed range and the pressure in the expansion-side chamber R1 or the compression-side chamber R2 becomes higher than the valve opening pressure of the expansion-side valve 9 or the leaf valve 31 provided in the damping passage P1.

[0098] When the shock absorber D expands, the liquid in the compressed expansion-side chamber R1 moves to the expanding compression-side chamber R2 via the expansion-side passage 7, and the rod 2 retreats from the cylinder 1, causing a shortage of liquid in the cylinder 1 by the volume of the rod 2 retreating. Therefore, the check valve 37 is opened and the shortage of liquid is supplied from the reservoir chamber R to the cylinder 1 via the suction passage P2 of the damping valve V. Therefore, during expansion at low speeds or higher, an expansion-side damping force based on the resistance of the expansion-side valve 9 is exerted, and the reservoir chamber R compensates for the volume.

[0099] Conversely, when the shock absorber D contracts, the liquid in the compressed compression side chamber R2 moves into the expanding expansion side chamber R1 via the compression side passage 8, and the rod 2 enters the cylinder 1, so that the liquid in the cylinder 1 corresponds to the volume of the rod 2 that has entered. Therefore, the excess liquid is discharged from the compression side chamber R2 to the reservoir chamber R through the damping passage P1 of the damping valve V. Therefore, during contraction at low speeds or higher, a compression side damping force based on the flow resistance of the damping passage P1 is exerted, and the reservoir chamber R compensates for the volume.

[0100] As described above, the damping valve V of this embodiment comprises a valve disc 30 having damping ports 30a as multiple ports arranged in the circumferential direction, a leaf valve 31 as an annular valve body that is stacked on the valve disc 30 and opens and closes the damping port 30a, and a spring member 40 that urges the leaf valve 31 toward the valve disc 30, and the spring member 40 has three or more coil springs 41 arranged along the circumferential direction of the leaf valve 31.

[0101] According to this configuration, by adjusting the circumferential position and spring load of each coil spring 41, it is possible to control the distribution of the spring load of the spring member 40 acting in the circumferential direction on the leaf valve 31, thereby adjusting the characteristics of the pressure loss that occurs when liquid passes through the leaf valve 31. Therefore, in the shock absorber D equipped with this damping valve V, it is possible to adjust the damping force characteristics.

[0102] In addition, since the damping valve V of this embodiment biases the leaf valve 31 with three or more coil springs 41, the diameter of the coil spring 41 is smaller than when the valve body is biased with one coil spring as in the conventional damping valve. Therefore, in the damping valve V of this embodiment, it is possible to reduce bias in the spring load of each coil spring 41 and to reduce variation in the spring load of each coil spring 41 between products.

[0103] The valve disc is not limited to the leaf valve 31 in which the inner circumference is fixed and the outer circumference flexes to open, but may be, for example, a leaf valve that is stacked on the valve disc 30 and can be moved toward or away from the valve disc 30 so that the entire valve disc 30 lifts up when it receives pressure from the compression side chamber R2.

[0104] In contrast, in the damping valve V of this embodiment, the leaf valve 31 is biased by three or more coil springs 41, and therefore the diameter of each coil spring 41 is smaller than when the valve body is biased by one coil spring as in the conventional damping valve. Here, the smaller the diameter of the coil spring 41, the smaller the circumferential bias of the load of the coil spring 41 becomes. Therefore, in the damping valve V of this embodiment, the influence of the circumferential bias of the spring load of the coil spring 41 is also reduced, and therefore there is almost no variation in the damping force characteristics of the shock absorber D for each product.

[0105] In the damping valve V of this embodiment, each coil spring 41 has the same natural length and spring constant, and is arranged at equal intervals in the circumferential direction. With this configuration, the spring load of the spring member 40 acts evenly on the leaf valve 31 in the circumferential direction, so that the opening timing of the leaf valve 31 does not vary in the circumferential direction, and the shock absorber D can exert the desired damping force.

[0106] However, the natural length of at least one of the coil springs 41 may be different from the natural lengths of the other coil springs 41, or the spring constant of at least one of the coil springs 41 may be different from the spring constants of the other coil springs 41. According to this configuration, by intentionally biasing the distribution of the spring load of the spring member 40, the opening manner of the leaf valve 31 can be set arbitrarily, and therefore the damping force characteristics of the shock absorber D can be adjusted.

[0107] Moreover, in the damping valve V of this embodiment, the spring member 40 has an annular holder 42 provided with a plurality of accommodating portions 43 for accommodating the respective coil springs 41. With this configuration, the coil springs 41 can be automatically positioned at desired positions in the circumferential direction, and the assembly work of the spring member 40 becomes easy. However, the holder 42 does not have to be provided with the accommodating portions 43.

[0108] In addition, the damping valve V of this embodiment is equipped with a cylindrical housing H that accommodates the valve disc 30, the leaf valve 31 and the spring member 40 therein and has a threaded portion 27d on its inner circumference, a spring adjuster 50 that is threadedly engaged with the threaded portion 27d and rotates circumferentially to displace axially relative to the housing H and thereby change the support position of the anti-leaf valve side end of the spring member 40 in the axial direction, and a washer 53 that is interposed between the spring adjuster 50 and the spring member 40 and serves as a bearing to reduce friction generated between the spring adjuster 50 and the spring member 40.

[0109] With this configuration, even if the spring adjuster 50 is rotated, the washer 53 slips, making it difficult for the rotational force of the spring adjuster 50 to be transmitted to the spring member 40, thereby preventing the coil spring 41 from twisting and the support portion 51a of the spring adjuster 50 from rubbing against the spring member 40, which could cause contamination.

[0110] In this embodiment, the washer 53 is used as the bearing, but the washer 53 is only an example, and the bearing is not particularly limited and may be, for example, a ball bearing, as long as it reduces friction generated between the support portion 51a and the spring member 40. However, since the washer 53 is inexpensive and thin compared to a ball bearing or the like, when the washer 53 is used as the bearing, it is possible to reduce the cost of the damping valve V while suppressing an increase in size of the damping valve V.

[0111] In addition, in the damping valve V of this embodiment, the housing H includes a housing main body 24 and a cap 27 that is screwed into the opening of the housing main body 24 and has a screw portion 27d into which the spring adjuster 50 is screwed, and a cylindrical spacer 47 that accommodates the coil spring 41 therein is interposed between one end of the cap 27 and the valve disc 30, and the spacer 47 has a guide cylindrical portion 47b that regulates the radial deflection of the coil spring 41.

[0112] According to this configuration, the guide tube portion 47b of the spacer 47 faces the outside of each coil spring 41 and suppresses radial deformation of each coil spring 41, thereby preventing each coil spring 41 from bending outward when compressed.

[0113] Moreover, the damping valve V of this embodiment has an annular spring receiver 46 interposed between the leaf valve 31 side end of each coil spring 41 and the leaf valve 31. With this configuration, the end of the coil spring 41 does not directly abut against the back surface of the leaf valve 31, so that it is possible to prevent the leaf valve 31 from being damaged. However, the spring receiver 46 may be omitted and the coil spring 41 may be directly abutted against the leaf valve 31.

[0114] In the damping valve V of this embodiment, the valve disc 30 has a plurality of valve seats 30c that independently surround the outlet ends of the respective damping ports 30a.

[0115] According to this configuration, by arranging each coil spring 41 so as to face each damping port 30a, the valve opening pressure of each damping port 30a can be set independently, so that the damping force characteristics of the shock absorber D can be easily adjusted.

[0116] In addition, when the damping port 30a is a so-called independent port, an opening pressure is set for each damping port 30a. Therefore, if there is unintended variation in the distribution of the spring load acting on the valve body as in conventional damping valves, variation will occur in the opening pressures of each damping port 30a when the leaf valve 31 opens it, and the timing at which each damping port 30a opens will not be as intended, and the damping force characteristics of the shock absorber will not be as designed.

[0117] In contrast, when the valve seat 30c is made annular so as to surround the outlet ends of all the damping ports 30a and the damping ports 30a are made so-called annular ports, the outlet ends of the damping ports 30a are connected to each other. Therefore, even if there is unintended variation in the distribution of the spring load acting on the valve body as in conventional damping valves, when the leaf valve 31 is opened, liquid flows through all the damping ports 30a, and there is no change in the number of ports that are effective when the valve is open.

[0118] Therefore, making the damping port 30a an independent port rather than an annular port has a greater disadvantage in that the damping force characteristics cannot be set as desired when there is unintended variation in the distribution of the spring load acting on the valve body, as is the case with conventional damping valves.

[0119] Here, as described above, the damping valve V of this embodiment can control the distribution of the spring load of the spring member 40 acting on the leaf valve 31 in the circumferential direction, so that unintended variations do not occur in the distribution of the spring load. Therefore, the damping valve V of this embodiment has a great benefit in that the damping force characteristics can be set as desired when the damping port 30a is an independent port.

[0120] The shock absorber D of this embodiment includes a cylinder 1, a rod 2 inserted into the cylinder 1 so as to be axially movable, and a shock absorber body 4 having a compression side chamber R2 and a reservoir chamber R as two working chambers through which liquid moves when the shock absorber expands or contracts, and the damping valve V of the present invention is provided midway through a passage that communicates between the compression side chamber R2 and the reservoir chamber R. With this configuration, the damping force characteristics of the compression side damping force of the shock absorber D can be adjusted by the damping valve V.

[0121] In this embodiment, the damping valve V is provided between the compression side chamber R2 and the reservoir chamber R, but the damping valve V may be provided in the middle of the passage that communicates between the expansion side chamber R1 and the compression side chamber R2. With this configuration, the damping force characteristics of the expansion side damping force of the shock absorber D can be adjusted by the damping valve V.

[0122] Although the preferred embodiment of the present invention has been described in detail above, it will be appreciated that modifications, variations and changes can be made thereto without departing from the scope of the appended claims. [Explanation of symbols]

[0123] DESCRIPTION OF SYMBOLS 1···Cylinder, 2···Rod, 4···Shock absorber body, 24···Housing body, 27···Cap, 27d···Threaded portion, 30···Valve disc, 30a···Damping port (port), 30c···Valve seat, 31···Leaf valve (valve body), 40···Spring member, 41···Coil spring, 42···Holder, 43···Accommodation portion, 46···Spring receiver, 47···Spacer, 47b···Guide tube portion, 50···Spring adjuster, 53···Washer (bearing), D···Shock absorber, H···Housing, R···Reservoir chamber, R1···Extension side chamber, R2···Compression side chamber, V···Damping valve

Claims

1. a valve disc having a plurality of circumferentially arranged ports; an annular valve body that is laminated on the valve disc and opens and closes the port; a spring member that abuts against a side of the valve body opposite to the valve disc and biases the valve body toward the valve disc, The spring member includes three or more coil springs arranged along a circumferential direction of the valve body, The valve element is a leaf valve. A damping valve characterized by:

2. The coil springs have the same natural length and spring constant, and are arranged at equal intervals in the circumferential direction.

2. The damping valve according to claim 1 .

3. At least one of the coil springs has a natural length different from the natural lengths of the other coil springs, or At least one of the coil springs has a spring constant different from the spring constants of the other coil springs.

2. The damping valve according to claim 1 .

4. The spring member has an annular holder having a plurality of housing portions for housing the coil springs. A damping valve according to any one of claims 1 to 3.

5. a cylindrical housing that accommodates the valve disc, the valve body, and the spring member therein and has a threaded portion on an inner periphery; a spring adjuster that is screwed into the screw portion and rotates in a circumferential direction to displace in an axial direction relative to the housing and change a support position of the opposite end of the spring member in the axial direction; a bearing interposed between the spring adjuster and the spring member to reduce friction generated between the spring adjuster and the spring member. A damping valve according to any one of claims 1 to 4.

6. the housing includes a housing body and a cap that is screwed into an opening of the housing body and has the screw portion into which the spring adjuster is screwed; a cylindrical spacer for accommodating the coil spring therein is interposed between one end of the cap and the valve disc; The spacer has a guide tube portion that restricts radial deflection of the coil spring.

6. The damping valve according to claim 5.

7. The spring member has an annular spring support interposed between the valve body side end of each of the coil springs and the valve body. A damping valve according to any one of claims 1 to 6.

8. The valve disc has a plurality of valve seats each independently surrounding the outlet end of each of the ports. A damping valve according to any one of claims 1 to 7.

9. a shock absorber body having a cylinder, a rod inserted into the cylinder so as to be freely movable in the axial direction, and two working chambers through which liquid moves when the rod expands and contracts; and a damping valve according to any one of claims 1 to 8, which is provided in a passage communicating between the two working chambers. A shock absorber characterized by:

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