JP2023005202A - Shock absorber - Google Patents

Abstract

To provide a shock absorber capable of suppressing the deterioration of functions.SOLUTION: A shock absorber includes: an accumulator 190 that has a disc valve 100, a disc spring 116 in which the disc valve 100 and an abutting portion 416 on one end side abut on each other, and a case member 95 that abuts on the other side of the disc spring 116 and covers the disc valve 100 and the disc spring 116; and a stopper portion 123 that suppresses the displacement of the abutting portion 416 to the other end side from a part 417 on the inner peripheral surface than the abutting portion 416 of the disc spring 116.SELECTED DRAWING: Figure 3

Description

The present invention relates to shock absorbers.

Some shock absorbers have two valves that open in the same stroke (see Patent Document 1, for example).

Japanese Patent Publication No. 2-41666

By the way, some shock absorbers use disc springs. Since the disc spring is formed of a thin plate, when it is largely deformed in the axial direction, there is a possibility that the shape will be reversed in the axial direction. In that case, the function of the buffer may deteriorate.

An object of the present invention is to provide a shock absorber capable of suppressing functional deterioration.

In order to achieve the above object, a first aspect of the present invention includes a piston that partitions the inside of a cylinder into two chambers, a piston rod that is connected to the piston and extends to the outside of the cylinder, and the piston a first passage through which the working fluid flows out from at least one of the two chambers, a first damping force generating mechanism provided in the first passage for generating a damping force, and a first damping force generating mechanism parallel to the first passage. a second damping force generating mechanism that is provided in the second passage and opens to generate a damping force when the piston speed is lower than that of the first damping force generating mechanism; and the second damping force generating mechanism. a third passage provided in parallel with the third passage; a disc valve provided in the third passage; an accumulator having a case member that covers the disc valve and the disc spring; and suppresses the contact portion from being displaced toward the other end side of a portion of the disc spring that is located on the inner peripheral side of the corresponding contact portion of the disc spring. and a stopper portion.

ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to suppress the deterioration of a function.

BRIEF DESCRIPTION OF THE DRAWINGS It is sectional drawing which shows the shock absorber of 1st Embodiment which concerns on this invention. It is a partial cross-sectional view showing the vicinity of a piston of the shock absorber of the first embodiment according to the present invention. It is a fragmentary sectional view showing the principal part of the shock absorber of a 1st embodiment concerning the present invention. It is a fragmentary sectional view showing the principal part of the shock absorber of a 2nd embodiment concerning the present invention. It is a fragmentary sectional view showing the principal part of the shock absorber of a 3rd embodiment concerning the present invention. It is a fragmentary sectional view showing the principal part of the shock absorber of a 4th embodiment concerning the present invention.

[First embodiment]
A first embodiment will be described with reference to FIGS. 1 to 3. FIG. In the following description, for convenience of explanation, the upper side in the drawings will be referred to as "upper" and the lower side in the drawings will be referred to as "lower".

<Configuration>
A shock absorber 1 of the first embodiment is a shock absorber used in a suspension system for a railway vehicle, a two-wheeled vehicle, a four-wheeled vehicle, or the like. The shock absorber 1 is specifically a shock absorber used in a suspension system for a four-wheeled vehicle. As shown in FIG. 1, the shock absorber 1 is a twin-tube shock absorber provided with a cylinder 4 having an inner cylinder 2 and an outer cylinder 3 . The inner cylinder 2 is cylindrical. The outer cylinder 3 has a bottomed cylindrical shape with a diameter larger than that of the inner cylinder 2 . The outer cylinder 3 is provided radially outside the inner cylinder 2 and coaxially with the inner cylinder 2 . A reservoir chamber 5 is provided between the outer cylinder 3 and the inner cylinder 2 .

The outer cylinder 3 has a body member 8 and a bottom member 9 . The body member 8 has a stepped cylindrical shape with both axial end sides having a smaller diameter than the axial intermediate portion. The bottom member 9 closes one axial end of the body member 8 . The side of the body member 8 opposite to the bottom member 9 is an opening.

The damper 1 has a valve body 12 and a rod guide 13 . The valve body 12 has an annular shape and is provided at one axial end of the inner cylinder 2 . The rod guide 13 has an annular shape and is provided at the other axial ends of the inner cylinder 2 and the outer cylinder 3 . The valve body 12 constitutes the base valve 15 and has a stepped outer peripheral portion. The rod guide 13 also has a stepped outer peripheral portion, and its large-diameter portion is placed on the body member 8 while being positioned in the radial direction.

One axial end of the inner cylinder 2 is fitted to a small-diameter portion of the outer periphery of the valve body 12 . One axial end of the inner cylinder 2 is engaged with the bottom member 9 of the outer cylinder 3 through the valve body 12 . In addition, the inner cylinder 2 has the other end portion in the axial direction fitted to the small diameter portion of the outer peripheral portion of the rod guide 13 . The other axial end of the inner cylinder 2 is engaged with the body member 8 of the outer cylinder 3 via the rod guide 13 . In this state, the inner cylinder 2 is radially positioned with respect to the outer cylinder 3 . Here, the valve body 12 and the bottom member 9 communicate with the inner cylinder 2 and the outer cylinder 3 via a passage groove 16 formed in the valve body 12 . A reservoir chamber 5 is formed between the valve body 12 and the bottom member 9 in the same way as between the inner cylinder 2 and the outer cylinder 3 .

The buffer 1 has a sealing member 18 . The sealing member 18 is provided on the opposite side of the rod guide 13 from the bottom member 9 . This seal member 18 is also fitted to the inner peripheral portion of the body member 8 in the same manner as the rod guide 13 . A locking portion 19 is formed at the end of the body member 8 opposite to the bottom member 9 . The locking portion 19 is formed by plastically deforming the body member 8 radially inward by crimping such as curling. The seal member 18 is sandwiched between the locking portion 19 and the rod guide 13 . The seal member 18 closes the opening of the outer cylinder 3, and is specifically an oil seal.

The damper 1 has a piston 21 . The piston 21 is slidably provided within the cylinder 4 . The piston 21 is slidably provided in the inner cylinder 2 of the cylinder 4 . The piston 21 divides the interior of the inner cylinder 2 into two chambers, an upper chamber 22 and a lower chamber 23 . The upper chamber 22 is provided between the piston 21 and the rod guide 13 inside the inner cylinder 2 . The lower chamber 23 is provided between the piston 21 and the valve body 12 inside the inner cylinder 2 . The lower chamber 23 is defined as the reservoir chamber 5 by the valve body 12 . In the cylinder 4, an upper chamber 22 and a lower chamber 23 are filled with an oil L as a working fluid. In the cylinder 4, a reservoir chamber 5 is filled with a gas G and an oil liquid L as working fluids.

The damper 1 has a piston rod 25 . One axial end portion of the piston rod 25 is disposed inside the cylinder 4 and connected and fixed to the piston 21 . The piston rod 25 also has the other end portion extending outside the cylinder 4 . The piston rod 25 is made of metal and extends through the upper chamber 22 . The piston rod 25 does not pass through the lower chamber 23. Therefore, the upper chamber 22 is a rod-side chamber through which the piston rod 25 passes. The lower chamber 23 is a bottom side chamber of the cylinder 4 on the side of the bottom member 9 .

Piston 21 and piston rod 25 move together. In the extension stroke of the shock absorber 1 in which the piston rod 25 protrudes from the cylinder 4, the piston 21 moves toward the upper chamber 22 side. The piston 21 moves toward the lower chamber 23 during the contraction stroke of the shock absorber 1 in which the amount of protrusion of the piston rod 25 from the cylinder 4 is reduced.

Both the rod guide 13 and the seal member 18 are annular. The piston rod 25 is slidably inserted inside the rod guide 13 and the seal member 18 and extends from the inside of the cylinder 4 to the outside. One axial end portion of the piston rod 25 is fixed to the piston 21 inside the cylinder 4 . The other axial end portion of the piston rod 25 extends outside the cylinder 4 via the rod guide 13 and the seal member 18 .

The rod guide 13 supports the piston rod 25 with respect to the cylinder 4 so as to be axially movable while restricting its radial movement. The rod guide 13 guides the axial movement of the piston rod 25 . The seal member 18 is in close contact with the outer cylinder 3 of the cylinder 4 at its outer peripheral portion. The inner peripheral portion of the seal member 18 is in sliding contact with the outer peripheral portion of the piston rod 25 moving in the axial direction. Thereby, the seal member 18 prevents the oil liquid L and the gas G in the cylinder 4 from leaking to the outside.

The piston rod 25 has a main shaft portion 27 and a mounting shaft portion 28 . The mounting shaft portion 28 has a smaller diameter than the main shaft portion 27 . A main shaft portion 27 of the piston rod 25 is slidably fitted to the rod guide 13 and the seal member 18 . A mounting shaft portion 28 of the piston rod 25 is disposed inside the cylinder 4 and connected to the piston 21 and the like. An end portion of the main shaft portion 27 on the mounting shaft portion 28 side forms a shaft stepped portion 29 extending in the direction perpendicular to the axis.

A passage cutout portion 30 is formed in the outer peripheral portion of the mounting shaft portion 28 . The passage cutout portion 30 is formed at an intermediate position in the axial direction of the mounting shaft portion 28 and extends in the axial direction of the mounting shaft portion 28 . A male screw 31 is formed on the outer peripheral portion of the attachment shaft portion 28 at the tip position on the side opposite to the main shaft portion 27 in the axial direction. The passage cutout portion 30 is formed, for example, by notching the outer peripheral portion of the mounting shaft portion 28 in a plane parallel to the central axis of the mounting shaft portion 28 . The passage cutouts 30 can be formed in a so-called width across flat shape at two locations that are 180 degrees apart in the circumferential direction of the mounting shaft 28 .

The damper 1 is supported by the vehicle body, for example, with the portion of the piston rod 25 protruding from the cylinder 4 arranged at the top in the vertical direction. At that time, the shock absorber 1 is connected to the wheel side with the bottom member 9 of the cylinder 4 arranged at the bottom in the vertical direction. Conversely, the cylinder 4 side may be supported by the vehicle body, and the piston rod 25 may be connected to the wheel side.

As shown in FIG. 2, the piston 21 has a metal piston body 36 and a synthetic resin sliding member 37 . The piston body 36 is connected in contact with the piston rod 25 . The sliding member 37 is integrally attached to the outer peripheral surface of the piston body 36 . The piston 21 slides in the inner cylinder 2 of the cylinder 4 with the sliding member 37 in contact with the inner cylinder 2 .

The piston body 36 is provided with a plurality of passage holes 38 (only one location is shown because it is a cross section in FIG. 2) and a plurality of passage holes 39 (only one location is shown because it is a cross section in FIG. 2). there is Both the plurality of passage holes 38 and the plurality of passage holes 39 can communicate the upper chamber 22 and the lower chamber 23 .

The plurality of passage holes 38 are arranged at equal pitches in the circumferential direction of the piston body 36 . The plurality of passage holes 38 are arranged in the circumferential direction of the piston body 36 with one passage hole 39 sandwiched therebetween. A plurality of passage holes 38 constitute half of the total number of passage holes 38 and 39 . Each of the plurality of passage holes 38 has a crank shape with two bending points. In each of the plurality of passage holes 38 , the axial end of the piston 21 on the lower chamber 23 side opens radially inward of the piston 21 from the end on the upper chamber 22 side. An annular groove 55 is formed in the piston body 36 on the lower chamber 23 side in the axial direction. The annular groove 55 communicates with the passage holes 38 .

A first damping force generating mechanism 41 is provided on the lower chamber 23 side of the annular groove 55 . The first damping force generating mechanism 41 opens and closes passages in the plurality of passage holes 38 and the annular groove 55 to generate damping force. By arranging the first damping force generating mechanism 41 on the lower chamber 23 side, the passages in the plurality of passage holes 38 and in the annular groove 55 are on the upstream side when the piston 21 moves toward the upper chamber 22 side. It becomes a passage through which the oil liquid L flows from the chamber 22 toward the lower chamber 23 on the downstream side. The passages in the plurality of passage holes 38 and in the annular groove 55 are elongation-side passages through which the oil L flows from the upper chamber 22 on the upstream side toward the lower chamber 23 on the downstream side in the elongation stroke of the shock absorber 1. Become. The first damping force generating mechanism 41 is provided for passages in the plurality of passage holes 38 on the extension side and in the annular groove 55 . The first damping force generating mechanism 41 generates a damping force by suppressing the flow of the oil L from the passages in the plurality of passage holes 38 and the annular groove 55 to the lower chamber 23 on the extension side. This is the generation mechanism.

A plurality of passage holes 39, which constitute the remaining half of the total number of passage holes 38, 39, are arranged at equal pitches in the circumferential direction of the piston body 36. As shown in FIG. A plurality of passage holes 39 are arranged with one passage hole 38 therebetween. Each of the plurality of passage holes 39 has a crank shape with two bending points. In each of the plurality of passage holes 39 , the end portion on the upper chamber 22 side in the axial direction of the piston 21 opens further inward in the radial direction of the piston 21 than the end portion on the lower chamber 23 side. An annular groove 56 is formed in the piston body 36 on the upper chamber 22 side in the axial direction. The annular groove 56 communicates the plurality of passage holes 39 .

A first damping force generating mechanism 42 is provided on the upper chamber 22 side of the annular groove 56 . The first damping force generating mechanism 42 opens and closes passages in the plurality of passage holes 39 and the annular groove 56 to generate damping force. By arranging the first damping force generating mechanism 42 on the upper chamber 22 side, the passages in the plurality of passage holes 39 and in the annular groove 56 are on the upstream side when the piston 21 moves toward the lower chamber 23 side. It becomes a passage through which the oil liquid L flows from the chamber 23 toward the upper chamber 22 on the downstream side. The passages in the plurality of passage holes 39 and in the annular groove 56 are contraction-side passages through which the oil L flows from the lower chamber 23 on the upstream side toward the upper chamber 22 on the downstream side in the contraction stroke of the shock absorber 1. Become. The first damping force generating mechanism 42 is provided for passages in the plurality of passage holes 39 and the annular groove 56 on the compression side. The first damping force generating mechanism 42 suppresses the flow of the oil L from the passages in the plurality of passage holes 39 and the annular groove 56 on the compression side to the upper chamber 22 to generate a damping force on the compression side. This is the generation mechanism.

The piston body 36 has a substantially disk shape, and an insertion hole 44 is formed in the center in the radial direction. The insertion hole 44 penetrates the piston body 36 in its axial direction. The mounting shaft portion 28 of the piston rod 25 is inserted into the insertion hole 44 . The insertion hole 44 has a small diameter hole portion 45 and a large diameter hole portion 46 . The small-diameter hole portion 45 is arranged on one side from the axial center of the insertion hole 44 . The large-diameter hole portion 46 is arranged on the other axial side of the insertion hole 44 . The large diameter hole portion 46 has a larger diameter than the small diameter hole portion 45 . The piston body 36 has a small diameter hole portion 45 provided on the upper chamber 22 side in the axial direction, and a large diameter hole portion 46 provided on the lower chamber 23 side in the axial direction. The mounting shaft portion 28 of the piston rod 25 is fitted in the small diameter hole portion 45 of the piston 21 . Thereby, the piston 21 is radially positioned with respect to the piston rod 25 .

An inner seat portion 47 and a valve seat portion 48 are formed at the axial end of the piston body 36 on the lower chamber 23 side. The inner seat portion 47 is arranged radially inward of the piston body 36 from the opening of the annular groove 55 on the lower chamber 23 side. The inner seat portion 47 is annular. The valve seat portion 48 is arranged radially outward of the piston body 36 from the opening of the annular groove 55 on the lower chamber 23 side. The valve seat portion 48 is annular. The valve seat portion 48 forms part of the first damping force generating mechanism 41 .

An inner seat portion 49 and a valve seat portion 50 are formed at the axial end of the piston body 36 on the side of the upper chamber 22 . The inner seat portion 49 is arranged radially inward of the piston body 36 from the opening of the annular groove 56 on the side of the upper chamber 22 . The inner seat portion 49 is annular. The valve seat portion 50 is arranged radially outward of the piston body 36 from the opening of the annular groove 56 on the side of the upper chamber 22 . The valve seat portion 50 has an annular shape. The valve seat portion 50 forms part of the first damping force generating mechanism 42 .

In the insertion hole 44 of the piston body 36 , the large-diameter hole portion 46 is provided closer to the inner seat portion 47 in the axial direction than the small-diameter hole portion 45 . The passage in the large-diameter hole portion 46 of the piston body 36 overlaps with the piston rod passage portion 51 in the passage cutout portion 30 of the piston rod 25 in the axial direction. A passage in the large-diameter hole portion 46 always communicates with the piston rod passage portion 51 .

In the piston body 36 , the radially outer side of the valve seat portion 48 has a stepped shape whose axial height is lower than that of the valve seat portion 48 . In the piston main body 36, an opening on the lower chamber 23 side of the passage hole 39 on the contraction side is arranged in this stepped portion. Similarly, in the piston body 36 , the radially outer side of the valve seat portion 50 has a stepped shape whose height in the axial direction is lower than that of the valve seat portion 50 . In the piston body 36, the opening of the extension-side passage hole 38 on the upper chamber 22 side is arranged in this stepped portion.

The compression-side first damping force generating mechanism 42 includes the valve seat portion 50 of the piston 21 . The first damping force generating mechanism 42 includes one disc 63, a plurality of (specifically two) discs 64, and a plurality of (specifically three) discs 64 in order from the piston 21 side in the axial direction. disk 65 , a plurality of (specifically two) disks 66 , one disk 67 , one disk 68 , and one annular member 69 . The plurality of discs 64 have the same outer diameter. The plurality of discs 65 have the same outer diameter. The plurality of discs 66 have the same outer diameter. Each of the disks 63 to 68 and the annular member 69 is made of metal, and each has a perforated circular flat plate shape with a constant thickness and a constant radial width over the entire circumference. The discs 63 to 68 and the annular member 69 are radially positioned with respect to the piston rod 25 by fitting the mounting shaft portion 28 inside. Disks 63-68 are plain disks. A plain disk is a flat disk without axially projecting protrusions.

The disc 63 has an outer diameter that is larger than the inner diameter of the inner seat portion 49 of the piston 21 and smaller than the inner diameter of the valve seat portion 50 . The disc 63 is always in contact with the inner seat portion 49 . The plurality of discs 64 have the same outer diameter as the valve seat portion 50 of the piston 21 . Of the plurality of discs 64 , the disc 64 closest to the disc 63 can be seated on the valve seat portion 50 . The plurality of discs 65 have outer diameters smaller than the outer diameter of the discs 64 . The plurality of discs 66 has an outer diameter smaller than the outer diameter of the disc 65 . The disc 67 has an outer diameter smaller than the outer diameter of the disc 66 and equal to the outer diameter of the inner seat portion 49 of the piston 21 . The disc 68 has an outer diameter equal to that of the disc 65 . The annular member 69 has an outer diameter that is smaller than the outer diameter of the disk 68 and larger than the outer diameter of the shaft step portion 29 of the piston rod 25 . The annular member 69 is thicker and more rigid than the discs 63 to 68 and is in contact with the shaft stepped portion 29 .

A plurality of discs 64 , a plurality of discs 65 , and a plurality of discs 66 constitute a contraction-side main valve 71 that can be seated on and removed from the valve seat portion 50 . By separating from the valve seat portion 50 , the main valve 71 allows passages in the plurality of passage holes 39 and in the annular groove 56 to communicate with the upper chamber 22 . At that time, the main valve 71 suppresses the flow of the oil L between the valve seat portion 50 and generates a damping force. The annular member 69 and the disk 68 abut against the main valve 71 to restrict the deformation of the main valve 71 in the opening direction beyond a specified limit.

The passages in the plurality of passage holes 39 and the annular groove 56 and the passage between the main valve 71 and the valve seat portion 50 that appear when the valve is opened constitute a first passage 72 . A first passage 72 is provided in the piston 21 . In the first passage 72 , oil L flows from the lower chamber 23 on the upstream side in the cylinder 4 to the upper chamber 22 on the downstream side as the piston 21 moves toward the lower chamber 23 side. The first passage 72 is the contraction side passage. The compression-side first damping force generating mechanism 42 that generates damping force includes a main valve 71 and a valve seat portion 50 . Therefore, the first damping force generating mechanism 42 is provided in this first passage 72 . The first passage 72 is provided in the piston 21 including the valve seat portion 50, and allows the oil L to pass therethrough when the piston rod 25 and the piston 21 move toward the contraction side.

Here, in the first damping force generating mechanism 42 on the compression side, no fixed orifice is formed in either the valve seat portion 50 or the main valve 71 abutting thereon. The fixed orifice allows the upper chamber 22 and the lower chamber 23 to communicate with each other even when the valve seat portion 50 and the main valve 71 are in contact with each other. That is, the compression side first damping force generating mechanism 42 does not allow the upper chamber 22 and the lower chamber 23 to communicate with each other when the valve seat portion 50 and the main valve 71 are in contact with each other over the entire circumference. In other words, the first passage 72 is not provided with a fixed orifice that constantly communicates the upper chamber 22 and the lower chamber 23 . The first passage 72 is not a passage that always communicates between the upper chamber 22 and the lower chamber 23 .

The extension-side first damping force generating mechanism 41 includes a valve seat portion 48 of the piston 21 . The first damping force generating mechanism 41 includes, in order from the piston 21 side in the axial direction, one disk 82, one disk 83, a plurality of (specifically four) disks 84, and one disk. It has a disk 85 , a plurality of (specifically, three) disks 86 , and one disk 87 . The plurality of discs 84 have the same outer diameter. The plurality of discs 86 have the same outer diameter. The discs 82-87 are made of metal and have an annular shape. Each of the disks 83 to 87 is a perforated circular plate-shaped plain disk having a constant thickness and a constant radial width over the entire circumference. The discs 82 to 87 are radially positioned with respect to the piston rod 25 by fitting the mounting shaft portion 28 inside.

The disc 82 has an outer diameter that is larger than the outer diameter of the inner seat portion 47 of the piston 21 and smaller than the inner diameter of the valve seat portion 48 . The disk 82 is always in contact with the inner seat portion 47 . A notch portion 90 is formed in the disk 82 from an intermediate position outside the inner seat portion 47 in the radial direction to the inner peripheral edge portion. The notch 90 always communicates the passages in the annular groove 55 and the plurality of passage holes 38 with the passages in the large-diameter hole portion 46 of the piston 21 and the piston rod passage portion 51 of the piston rod 25 . The notch 90 is formed when the disk 82 is press-molded. The disk 83 has the same outer diameter as the disk 82 and does not have a notch like the disk 82 does. The plurality of discs 84 have the same outer diameter as the valve seat portion 48 of the piston 21 . The disk 84 closest to the disk 83 among the plurality of disks 84 can be seated on the valve seat portion 48 . The disc 85 has an outer diameter smaller than that of the disc 84 . The plurality of discs 86 have an outer diameter smaller than the outer diameter of the disc 85 . The disc 87 has an outer diameter smaller than the outer diameter of the disc 86 and slightly larger than the outer diameter of the inner seat portion 47 of the piston 21 .

A plurality of discs 84 , a single disc 85 , and a plurality of discs 86 constitute an extension-side main valve 91 that can be seated on and removed from the valve seat portion 48 . By separating from the valve seat portion 48 , the main valve 91 allows passages in the annular groove 55 and the plurality of passage holes 38 to communicate with the lower chamber 23 . At that time, the main valve 91 suppresses the flow of the oil L between the valve seat portion 48 and generates a damping force.

The passages within the plurality of passage holes 38 and the annular groove 55 and the passage between the main valve 91 and the valve seat portion 48 that appear when the valve is opened constitute a first passage 92 . A first passage 92 is formed in the piston 21 . In the first passage 92 , the oil L flows from the upper chamber 22 on the upstream side in the cylinder 4 to the lower chamber 23 on the downstream side as the piston 21 moves toward the upper chamber 22 side. The first passage 92 is an extension side passage. The extension-side first damping force generating mechanism 41 that generates damping force includes a main valve 91 and a valve seat portion 48 . Therefore, the first damping force generating mechanism 41 is provided in this first passage 92 . The first passage 92 is provided in the piston 21 including the valve seat portion 48, and the oil L passes through it when the piston rod 25 and the piston 21 move to the extension side.

In the extension-side first damping force generating mechanism 41, neither the valve seat portion 48 nor the main valve 91 abutting thereon has a fixed orifice. The fixed orifice allows the upper chamber 22 and the lower chamber 23 to communicate with each other even when the valve seat portion 48 and the main valve 91 are in contact with each other. That is, the extension-side first damping force generating mechanism 41 does not allow the upper chamber 22 and the lower chamber 23 to communicate with each other when the valve seat portion 48 and the main valve 91 are in contact with each other over the entire circumference. In other words, the first passage 92 is not provided with a fixed orifice that constantly communicates the upper chamber 22 and the lower chamber 23 . The first passage 92 is not a passage that always communicates between the upper chamber 22 and the lower chamber 23 .

As shown in FIG. 3, on the side opposite to the piston 21 of the first damping force generating mechanism 41 on the extension side, one case member 95 and one disc spring are arranged in order from the first damping force generating mechanism 41 side. 116, one disk 97 and one disk valve 100 are provided. On the opposite side of the disc valve 100 to the disc 97, one valve seat disc 101, one disc 102, and one disc 104 are provided in this order from the disc valve 100 side. On the opposite side of the disk 104 to the disk 102, one spring member 105, one disk 106, one sub-valve 107, and one O-ring 108 are arranged in this order from the disk 104 side. A single valve seat member 109 is provided. On the opposite side of the valve seat member 109 from the sub-valve 107, one sub-valve 110, one disc 111, one spring member 112, and one disc 113 are arranged in this order from the valve seat member 109 side. and a piece of annular member 114 are provided. The case member 95, disc spring 116, discs 97, 102, 104, 106, 111, 113, disc valve 100, valve seat disc 101, spring members 105, 112, sub-valves 107, 110, valve seat member 109 and annular member 114 are , and the mounting shaft portion 28 of the piston rod 25 is fitted inside them. By fitting the mounting shaft portion 28 inside each, the case member 95, disc spring 116, discs 97, 102, 104, 106, 111, 113, disc valve 100, valve seat disc 101, and spring members 105, 112 , sub-valves 107 , 110 , valve seat member 109 and annular member 114 are radially positioned relative to piston rod 25 .

As shown in FIG. 2 , the mounting shaft portion 28 of the piston rod 25 is formed with a male thread 31 at a portion that protrudes beyond the annular member 114 . A nut 119 is screwed onto the male screw 31 . Nut 119 abuts annular member 114 .

Annular member 69, discs 63-68, 82-87, piston 21, case member 95, disc spring 116 shown in FIG. Spring members 105, 112, sub-valves 107, 110, valve seat member 109, and annular member 114 are axially supported by shaft stepped portion 29 of piston rod 25 and nut 119 at least on their radially inner peripheral sides, as shown in FIG. direction is clamped. These annular member 69, discs 63-68, 82-87, piston 21, case member 95, disc spring 116 shown in FIG. , spring members 105 and 112 , sub-valves 107 and 110 , valve seat member 109 and annular member 114 are fixed to piston rod 25 at least radially inwardly. In this state, discs 97, 102, 104, 106, 111, 113, disc valve 100, valve seat disc 101, spring members 105, 112, sub-valves 107, 110, valve seat member 109 and disc spring 116 are connected to case member 95. placed inside. In other words, the case member 95 covers the discs 97, 102, 104, 106, 111, 113, the disc valve 100, the valve seat disc 101, the spring members 105, 112, the sub-valve 107, the valve seat member 109 and the disc spring 116. there is

Case member 95, discs 97, 102, 104, 106, 111, 113, disc valve 100, valve seat disc 101, spring members 105, 112, sub-valves 107, 110, valve seat member 109, annular member 114 and disc spring 116 are , are all made of metal. Each of the disks 97, 102, 104, 106, 111, 113, the disk valve 100, the valve seat disk 101, the sub-valves 107, 110 and the annular member 114 has a constant thickness and a constant radial width over the entire circumference. It is a plain disk in the form of a perforated circular flat plate. The case member 95, the valve seat member 109, and the disc spring 116 all have an annular shape with a constant radial width over the entire circumference. The spring members 105, 112 are annular.

The case member 95 is an integrally molded product having a bottomed cylindrical shape, and is formed by, for example, plastic working or cutting of a metal plate. The case member 95 has a bottom portion 122 , an intermediate tapered portion 123 and a cylindrical portion 124 . The bottom portion 122 is in the form of a perforated disk of constant thickness. The intermediate tapered portion 123 extends from the outer peripheral edge portion of the bottom portion 122 to one side of the bottom portion 122 in the axial direction while increasing in diameter. The intermediate tapered portion 123 has an annular shape. The cylindrical portion 124 extends in the direction opposite to the bottom portion 122 from the edge portion of the intermediate taper portion 123 on the side opposite to the bottom portion 122 in the axial direction of the intermediate taper portion 123 . The tubular portion 124 is cylindrical.

The bottom portion 122 has a perforated circular plate shape with a constant radial width over the entire circumference. The bottom portion 122 has an inner peripheral portion to which the mounting shaft portion 28 of the piston rod 25 is fitted. Thereby, the case member 95 is radially positioned and coaxially arranged with respect to the piston rod 25 . A plurality of passage holes 126 are formed in the bottom portion 122 . The plurality of passage holes 126 are arranged between the inner peripheral portion and the outer peripheral portion of the bottom portion 122 and penetrate the bottom portion 122 in the axial direction of the bottom portion 122 . The plurality of passage holes 126 are arranged at equal intervals in the circumferential direction of the bottom portion 122 at positions equidistant from the center of the bottom portion 122 . The case member 95 abuts on the disk 87 with the bottom portion 122 positioned closer to the piston 21 than the cylindrical portion 124 in the axial direction. The outer diameter of the disk 87 is smaller than twice the shortest distance connecting the radial center of the case member 95 and the passage hole 126 .

The intermediate tapered portion 123 has a tapered shape coaxial with the bottom portion 122 . The intermediate tapered portion 123 has a tapered shape whose diameter increases with distance from the bottom portion 122 in the axial direction. Tubular portion 124 is also coaxial with bottom portion 122 and intermediate tapered portion 123 .

The bottom portion 122 has a planar bottom surface 122a on the cylindrical portion 124 side in the axial direction. The intermediate tapered portion 123 has a tapered inner surface 123a on the cylindrical portion 124 side in the axial direction. The inner surface 123a has a tapered shape that increases in diameter with increasing distance from the bottom surface 122a in the axial direction. The cylindrical portion 124 has a cylindrical inner peripheral surface 124a on the radially inner side. Bottom surface 122a of bottom portion 122 and inner surface 123a of intermediate tapered portion 123 are continuous. The inner surface 123a of the intermediate tapered portion 123 and the inner peripheral surface 124a of the cylindrical portion 124 are continuous.

The case member 95 is thicker than one of the discs 84 to 86 and has a higher rigidity than the discs 84 to 86 together with the fact that it has a cylindrical shape with a bottom. Therefore, the case member 95 abuts on the main valve 91 and restricts the deformation in the opening direction of the main valve 91 composed of the plurality of discs 84 to 86 beyond the specified limit.

The disc spring 116 is a perforated circular plate made of metal and is flexible. The disc spring 116 is formed from a sheet of plate material by punching by press molding and bending by press molding. The disc spring 116 has an inner annular portion 401 , an intermediate annular portion 402 , an outer tapered portion 403 and a support portion 404 . The inner annular portion 401 is in the shape of a perforated circular flat plate. The intermediate annular portion 402 is in the form of a perforated circular flat plate having an inner diameter larger than the outer diameter of the inner annular portion 401 . The support portion 404 is provided between the inner annular portion 401 and the intermediate annular portion 402 to connect them. The inner annular portion 401, the intermediate annular portion 402, and the support portion 404 are flat plates arranged on the same plane. The outer tapered portion 403 has a conical tubular shape that widens radially outward and axially to one side from the outer peripheral edge portion of the intermediate annular portion 402 . The disc spring 116 has an outer tapered portion 403 on the outer diameter side. The outer tapered portion 403 has a constant radial width over the entire circumference. The outer tapered portion 403 has a constant axial length over the entire circumference.

The disk spring 116 has an inner flat portion 414 having an inner annular portion 401 , an intermediate annular portion 402 and a support portion 404 on its inner diameter side. The inner flat plate portion 414 has a constant radial width over the entire circumference. In the inner flat plate portion 414, the inner annular portion 401, the intermediate annular portion 402, and the support portion 404 are arranged on the same plane. One end portion of the outer tapered portion 403 opposite to the inner flat plate portion 414 in the axial direction of the disc spring 116 is the outer peripheral end of the outer tapered portion 403 . The outer peripheral end of the outer tapered portion 403 is the outer peripheral end of the disc spring 116 . An outer peripheral end of the disc spring 116 forms a contact portion 416 that contacts the disc valve 100 . The contact portion 416 has an annular shape. The disc spring 116 has an inner flat plate portion 414 on the other end side opposite to the contact portion 416 on the one end side in the axial direction. The disc spring 116 has a main portion 417 at a portion on the inner peripheral side of the contact portion 416 . The main body portion 417 is composed of an inner flat plate portion 414 and a portion of the outer tapered portion 403 excluding the contact portion 416 .

The outer diameter of the outer tapered portion 403 of the disc spring 116 , that is, the outer diameter of the disc spring 116 is slightly smaller than the inner diameter of the cylindrical portion 124 of the case member 95 . The disc spring 116 has an inner flat plate portion 414 having an inner annular portion 401 , an intermediate annular portion 402 , and a support portion 404 abuts the bottom surface 122 a of the bottom portion 122 of the case member 95 . In this state, the disc spring 116 is in a state in which the outer tapered portion 403 extends to the same side as the cylindrical portion 124 in the axial direction. The disk spring 116 is radially positioned with respect to the piston rod 25 by fitting the mounting shaft portion 28 to the inner peripheral side of the inner annular portion 401 in this state. The disc spring 116 is formed such that the inner peripheral end thereof contacts the piston rod 25 . A tubular portion 124 of the case member 95 is arranged radially outside the disc spring 116 . The contact portion 416 of the disc spring 116 faces the inner surface 123a of the intermediate tapered portion 123 of the case member 95 in the axial direction.

Here, the intermediate tapered portion 123 of the case member 95 has an inner surface 123a whose minimum diameter is smaller than the outer diameter of the outer tapered portion 403 of the disc spring 116 and larger than the outer diameter of the inner flat plate portion 414. is. The inner surface 123 a of the intermediate tapered portion 123 has a maximum diameter larger than the outer diameter of the outer tapered portion 403 of the disc spring 116 . In other words, the inner surface 123 a of the intermediate tapered portion 123 has a minimum diameter smaller than the outer diameter of the contact portion 416 and a maximum diameter larger than the outer diameter of the contact portion 416 . The inner surface 123a of the intermediate tapered portion 123 is deformed toward the side where the disc spring 116 is arranged from the bottom surface 122a of the bottom portion 122 in the axial direction. Moreover, the inner surface 123a of the intermediate tapered portion 123 extends further to the side opposite to the bottom portion 122 than the inner flat portion 414 of the disc spring 116 in the axial direction. In other words, the inner surface 123a of the intermediate tapered portion 123 is positioned closer to the disc spring 116 than the bottom surface 122a of the bottom portion 122 in the axial direction. Further, in other words, the inner surface 123a of the intermediate taper portion 123 is axially wider than the end portion of the main portion 417 on the other axial end side of the disc spring 116, which is located on the inner peripheral side of the contact portion 416 on the one axial end side of the disc spring 116. is formed by deforming toward the contact portion 416 side. The inner surface 123 a of the intermediate tapered portion 123 is such that the contact portion 416 on the one end side of the disc spring 116 in the axial direction is located axially further than the main portion 417 , which is a portion on the inner peripheral side of the contact portion 416 . is suppressed from being displaced to the other end side. The case member 95 abuts against the disc spring 116 with the inner surface 123 a of the intermediate tapered portion 123 facing the contact portion 416 to suppress such displacement of the disc spring 116 .

The inner annular portion 401, the intermediate annular portion 402, and the outer tapered portion 403 all have a constant radial width over the entire circumference. The radial width of the outer tapered portion 403 is wider than the radial width of the inner annular portion 401 . The radial width of the inner annular portion 401 is wider than the radial width of the intermediate annular portion 402 . The inner annular portion 401, the intermediate annular portion 402, and the outer tapered portion 403 are coaxially arranged. The support portion 404 coaxially connects the inner annular portion 401 with the intermediate annular portion 402 and the outer tapered portion 403 . The support portion 404 extends in the circumferential direction of the inner annular portion 401 and the intermediate annular portion 402 and connects the outer peripheral edge of the inner annular portion 401 and the inner peripheral edge of the intermediate annular portion 402 .

The disc spring 116 is surrounded by the inner annular portion 401 , the intermediate annular portion 402 and the support portion 404 to form a hole portion 415 . The hole 415 penetrates the disc spring 116 in the thickness direction (axial direction). The hole portion 415 is provided between the inner annular portion 401 and the intermediate annular portion 402 . Therefore, the disc spring 116 has a hole 415 between the inner peripheral end and the outer peripheral end. The hole 415 is provided in the inner flat plate portion 414 .

In the disc spring 116 , the inner diameter of the intermediate annular portion 402 is smaller than twice the longest distance connecting the radial center of the case member 95 and the passage hole 126 . The inner diameter of the intermediate annular portion 402 is larger than twice the shortest distance between the radial center of the case member 95 and the passage hole 126 . Therefore, in the disc spring 116 , the passage in the hole portion 415 always communicates with the passage in the passage hole 126 of the bottom portion 122 . Also, in the disk spring 116, the outer diameter of the intermediate annular portion 402, that is, the inner diameter of the outer tapered portion 403, is larger than twice the longest distance connecting the radial center of the case member 95 and the passage hole 126. ing. The intermediate annular portion 402 of the disc spring 116 abuts on the outer side of the bottom portion 122 in the radial direction of all the passage holes 126 of the bottom surface 122 a of the bottom portion 122 of the case member 95 over the entire circumference.

The disk 97 has an outer diameter smaller than the outer diameter of the inner annular portion 401 of the disc spring 116 .
The disc spring 116 is axially clamped at the inner annular portion 401 by the bottom portion 122 of the case member 95 and the disc 97 . As a result, the inner annular portion 401 of the disc spring 116 is fixed to the piston rod 25 . Although the support portion 404 and the intermediate ring portion 402 abut against the bottom surface 122a of the case member 95, they do not abut against the disc 97 and are therefore not clamped in the axial direction.

Disc valve 100 is flexible. The disk valve 100 abuts on the piston rod 25 at its inner peripheral end. The disc valve 100 has an outer diameter larger than the outer diameter of the disc spring 116 and slightly smaller than the inner diameter of the cylindrical portion 124 of the case member 95 . The disk valve 100 has the same thickness as the disc spring 116 . A circular contact portion 416 of the disk spring 116 contacts the outer peripheral edge side of the disk valve 100 over the entire circumference.

The disk valve 100 is formed by stamping a single plate material by press molding. The disc valve 100 has a flat plate shape in its natural state before being assembled to the piston rod 25 . The disk valve 100 has a plurality of communication holes 501 formed at intermediate positions in the radial direction. All the communication holes 501 are round holes with the same diameter, and penetrate the disc valve 100 in its thickness direction (axial direction). All the communication holes 501 are formed at equidistant positions from the center of the disc valve 100 . All the communication holes 501 are formed at regular intervals in the circumferential direction of the disc valve 100 . The communication hole 501 of the disc valve 100 is formed at a position where the disc 97 does not block it.

The valve seat disk 101 has a flat plate shape in its natural state before it is attached to the piston rod 25 . The valve seat disk 101 has an outer diameter smaller than that of the disk valve 100 . The valve seat disk 101 has an outer diameter larger than twice the maximum distance connecting the center of the disk valve 100 and the communication hole 501 . The valve seat disk 101 abuts on the disk valve 100 over the entire circumference in surface contact. The valve seat disk 101 then closes all the communication holes 501 of the disk valve 100 .

The disc 102 has an outer diameter smaller than that of the valve seat disc 101 . The disc 102 is a common component having the same shape as the disc 97 . The disk 102 axially clamps the inner peripheral sides of the disk valve 100 and the valve seat disk 101 together with the disk 97 .
The disc 104 has an outer diameter larger than that of the valve seat disc 101 and slightly smaller than that of the disc valve 100 . The disc 104 is thicker and more rigid than the disc valve 100 and valve seat disc 101 .

The spring member 105 has a substrate portion 331 and a plurality of spring plate portions 332 . The substrate portion 331 has a perforated circular plate shape with a constant radial width over the entire circumference. The mounting shaft portion 28 is fitted to the inner peripheral portion of the substrate portion 331 . The plurality of spring plate portions 332 extend outward in the radial direction of the substrate portion 331 from equally spaced positions in the circumferential direction of the substrate portion 331 . The spring plate portion 332 is inclined with respect to the substrate portion 331 so as to separate from the substrate portion 331 in the axial direction of the substrate portion 331 toward the extension tip side. Spring member 105 contacts disk 104 at substrate portion 331 . The spring member 105 is attached to the attachment shaft portion 28 so that the spring plate portion 332 extends from the substrate portion 331 toward the sub-valve 107 in the axial direction of the substrate portion 331 .
The disk 106 has an outer diameter smaller than the outer diameter of the base portion 331 of the spring member 105 and larger than the outer diameter of the disk 102 . The base portion 331 of the spring member 105 contacts the disk 106 , and the plurality of spring plate portions 332 contact the sub-valve 107 .

As shown in FIG. 2, the valve seat member 109 is in the form of a perforated disc. A through hole 131 is formed in the radial center of the valve seat member 109 . The through hole 131 extends in the axial direction of the valve seat member 109 and penetrates the valve seat member 109 in the thickness direction. The mounting shaft portion 28 of the piston rod 25 is inserted into the through hole 131 . The through hole 131 has a small diameter hole portion 132 and a large diameter hole portion 133 . The large diameter hole portion 133 has a larger diameter than the small diameter hole portion 132 . The small diameter hole portion 132 is arranged on one axial side of the through hole 131 . The large-diameter hole portion 133 is arranged on the other side in the axial direction from the center of the through-hole 131 . The mounting shaft portion 28 of the piston rod 25 is fitted into the small diameter hole portion 132 .

The valve seat member 109 has an inner seat portion 134 and a valve seat portion 135 at the axial end on the large diameter hole portion 133 side. The inner seat portion 134 has an annular shape surrounding the large-diameter hole portion 133 . The valve seat portion 135 extends radially outward from the inner seat portion 134 . In addition, the valve seat member 109 has an inner seat portion 138 and a valve seat portion 139 at the end portion on the side of the small diameter hole portion 132 on the opposite side in the axial direction. The inner seat portion 138 has an annular shape surrounding the small-diameter hole portion 132 . A valve seat portion 139 extends radially outward from this inner seat portion 138 . The valve seat member 109 has a body portion 140 between the inner seat portion 134 and the valve seat portion 135 and the inner seat portion 138 and the valve seat portion 139 in the axial direction. The body portion 140 is in the shape of a perforated disc.

The inner sheet portion 134 protrudes to one side along the axial direction of the main body portion 140 from the inner peripheral edge portion of the main body portion 140 on the side of the large-diameter hole portion 133 in the axial direction. The valve seat portion 135 protrudes from the body portion 140 to the same side as the inner seat portion 134 along the axial direction of the body portion 140 on the radially outer side of the inner seat portion 134 . The inner sheet portion 134 has a flat surface on the tip surface on the protruding side, ie, the tip surface on the side opposite to the main body portion 140 . The tip surface of the valve seat portion 135 on the projecting side, that is, the tip surface on the side opposite to the body portion 140 is a flat surface. The tip surface of the inner seat portion 134 on the projecting side and the tip surface of the valve seat portion 135 on the projecting side spread in the direction orthogonal to the axis of the valve seat member 109 and are arranged on the same plane.

The inner sheet portion 138 protrudes from the inner peripheral edge portion of the body portion 140 on the side of the small-diameter hole portion 132 in the axial direction to the side opposite to the inner seat portion 134 along the axial direction of the body portion 140 . The valve seat portion 139 protrudes from the body portion 140 to the same side as the inner seat portion 138 along the axial direction of the body portion 140 on the radially outer side of the inner seat portion 138 . The inner sheet portion 138 has a flat surface on the tip surface on the protruding side, that is, the tip surface on the side opposite to the main body portion 140 . The tip surface of the valve seat portion 139 on the projecting side, that is, the tip surface on the side opposite to the body portion 140 is a flat surface. The tip surface of the inner seat portion 138 on the projecting side and the tip surface of the valve seat portion 139 on the projecting side spread in the direction orthogonal to the axis of the valve seat member 109 and are arranged on the same plane.

The valve seat portion 135 is a deformed petal-shaped seat that is not circular. The valve seat portion 135 has a plurality of valve seat forming portions 201 . These valve seat components 201 have the same shape and are arranged at equal intervals in the circumferential direction of the valve seat member 109 . The inner seat portion 134 has an annular shape centered on the central axis of the valve seat member 109 . A plurality of valve seat forming portions 201 radially extend from the inner seat portion 134 .

A passage concave portion 205 is formed inside each valve seat forming portion 201 . The passage recess 205 is formed by being surrounded by a portion of the inner seat portion 134 and the valve seat forming portion 201 . The passage concave portion 205 is recessed in the axial direction of the valve seat member 109 from the tip surface of the inner seat portion 134 on the projecting side and the tip surface of the valve seat forming portion 201 on the projecting side. The bottom surface of passage recess 205 is formed by body portion 140 . Passage recesses 205 are formed inside all the valve seat forming portions 201 .

A passage hole 206 is formed at the central position of the passage concave portion 205 in the circumferential direction of the valve seat member 109 . The passage hole 206 axially penetrates the valve seat member 109 by axially penetrating the body portion 140 . The passage hole 206 is a straight hole parallel to the central axis of the valve seat member 109 . A passage hole 206 is formed in the bottom surface of all the passage recesses 205 .

The valve seat portion 139 is also a deformed petal-shaped seat that is not circular. The valve seat portion 139 has a plurality of valve seat forming portions 211 . These valve seat forming portions 211 have the same shape and are arranged at regular intervals in the circumferential direction of the valve seat member 109 . The inner seat portion 138 has an annular shape centered on the central axis of the valve seat member 109 . A plurality of valve seat forming portions 201 radially extend from the inner seat portion 134 . The valve seat forming portion 211 has the same shape as the valve seat forming portion 201 .

A passage concave portion 215 is formed inside each valve seat forming portion 211 . The passage recess 215 is formed by being surrounded by a portion of the inner seat portion 138 and the valve seat forming portion 211 . The passage recess 215 is recessed in the axial direction of the valve seat member 109 from the tip surface of the inner seat portion 138 on the protruding side and the tip surface of the valve seat forming portion 211 on the protruding side. The bottom surface of passage recess 215 is formed by body portion 140 . Passage recesses 215 are formed inside all the valve seat forming portions 211 .

A passage hole 216 is formed at a central position of the passage concave portion 215 in the circumferential direction of the valve seat member 109 . The passage hole 216 axially penetrates the valve seat member 109 by axially penetrating the body portion 140 . The passage hole 216 is a straight hole parallel to the central axis of the valve seat member 109 . A passage hole 216 is formed in the bottom surface of all the passage recesses 215 .

Here, the circumferential arrangement pitch of the valve seat members 109 of the plurality of valve seat forming portions 201 is the same as the circumferential arrangement pitch of the valve seat members 109 of the plurality of valve seat forming portions 211 . The valve seat forming portion 201 and the valve seat forming portion 211 are shifted from each other by half the arrangement pitch in the circumferential direction of the valve seat member 109 . The passage hole 206 is arranged between the valve seat forming portions 211 adjacent to each other in the circumferential direction of the valve seat member 109 . Therefore, the passage hole 206 is arranged outside the range of the valve seat portion 139 . The passage hole 216 is arranged between the valve seat forming portions 201 adjacent to each other in the circumferential direction of the valve seat member 109 . Therefore, the passage hole 216 is arranged outside the range of the valve seat portion 135 .

The valve seat member 109 has a passage groove 221 on the large diameter hole portion 133 side in the axial direction. The passage groove 221 is formed in the inner seat portion 134 so as to cross the inner seat portion 134 in the radial direction. The passage groove 221 is recessed in the axial direction of the valve seat member 109 from the tip surface of the inner seat portion 134 on the side opposite to the main body portion 140 . The passage groove 221 also includes a space between adjacent valve seat forming portions 201 in the circumferential direction of the valve seat member 109 . The passage hole 216 opens to the bottom surface of the passage groove 221 . The passage in the passage groove 221 allows the passage in the passage hole 216 and the passage in the large-diameter hole portion 133 to communicate with each other.

The passage in the passage hole 216 and the passage in the passage recess 215 to which the passage hole 216 opens constitute a first passage portion 161 provided in the valve seat member 109 . A plurality of first passage portions 161 are provided in the valve seat member 109 at regular intervals in the circumferential direction of the valve seat member 109 . The passage groove 221 forms a radial passage 222 extending radially toward the first passage portion 161 . A plurality of radial passages 222 are provided in the valve seat member 109 at equal intervals in the circumferential direction of the valve seat member 109 . The first passage portion 161 and the radial passage 222 communicate with each other.

The valve seat member 109 has passage grooves 225 between adjacent valve seat forming portions 211 in the circumferential direction of the valve seat member 109 . The passage hole 206 opens to the bottom surface of the passage groove 225 . Therefore, the passage in passage groove 225 communicates with the passage in passage hole 206 .

The passage hole 206 and the passage concave portion 205 to which the passage hole 206 opens form a second passage portion 162 provided in the valve seat member 109 . A plurality of second passage portions 162 are provided in the valve seat member 109 at equal intervals in the circumferential direction of the valve seat member 109 .
A plurality of first passage portions 161 and a plurality of second passage portions 162 constitute a valve seat member passage portion 160 provided in the valve seat member 109 and through which the oil liquid L flows.

A seal groove 141 is formed in the valve seat member 109 at the central position in the axial direction of the outer peripheral portion of the body portion 140 . The seal groove 141 has an annular shape and is recessed radially inward from the outer peripheral surface of the body portion 140 . An O-ring 108 is arranged in this seal groove 141 . The valve seat member 109 is fitted to the cylindrical portion 124 of the case member 95 at its outer peripheral portion with the inner seat portion 138 and the valve seat portion 139 facing away from the bottom portion 122 . In this state, the O-ring 108 seals the gap between the tubular portion 124 of the case member 95 and the valve seat member 109 .

The case member 95 , the O-ring 108 and the valve seat member 109 form a case chamber 146 inside the case member 95 . Case chamber 146 is provided between bottom portion 122 of case member 95 and valve seat member 109 . As shown in FIG. 3, discs 97 , 102 , 104 , 106 , disc valve 100 , valve seat disc 101 , spring member 105 , sub-valve 107 and disc spring 116 are provided within case chamber 146 .

A lower communication chamber 149 is formed in the case chamber 146 . The lower communication chamber 149 is surrounded by the disc valve 100 , the valve seat disc 101 , the disc spring 116 , the disc 97 and the bottom portion 122 of the case member 95 . The lower communication chamber 149 always communicates with passages in the plurality of holes 415 of the disc spring 116 . The lower communication chamber 149 always communicates with passages in the plurality of passage holes 126 of the bottom portion 122 of the case member 95 .

An upper chamber communication chamber 147 is formed in the case chamber 146 . The upper chamber communication chamber 147 includes a case member 95, a disc spring 116, a disc valve 100, a valve seat disc 101, discs 102, 104, 106, a spring member 105, a sub-valve 107, and a valve seat member 109. surrounded by The lower chamber communication chamber 149 and the upper chamber communication chamber 147 are communicated by the disc spring 116, the disc valve 100 contacting the contact portion 416 of the disc spring 116, and the valve seat disc 101 contacting the disc valve 100. is blocked.

As shown in FIG. 2 , the annular valve seat member 109 and the bottomed cylindrical case member 95 are arranged in the lower chamber 23 which is one of the upper chamber 22 and the lower chamber 23 . At this time, the valve seat member 109 has the valve seat portion 135 arranged on the case chamber 146 side. At this time, the valve seat portion 139 of the valve seat member 109 is arranged on the lower chamber 23 side. As shown in FIG. 3, the passage in the passage hole 126 of the case member 95 always communicates with the lower chamber 23 .

The upper chamber communication chamber 147 includes a passage between the tubular portion 124 of the case member 95 and the sub-valve 107, a radial passage 222 in the passage groove 221 of the valve seat member 109, and a large diameter hole portion of the valve seat member 109. 133, the passages in the piston rod passage portion 51 of the piston rod 25 and the large diameter hole portion 46 of the piston 21, the passages in the notch portion 90 of the disk 82, the annular groove 55 of the piston 21 and a plurality of passages. 2 through passages in holes 38. As shown in FIG.

As the disc valve 100 shown in FIG. 3 bends in the axial direction, the volumes of the lower chamber communication chamber 149 and the upper chamber communication chamber 147 change. That is, the lower chamber communication chamber 149 and the upper chamber communication chamber 147 function as accumulators by bending the disc valve 100 . The lower communication chamber 149 discharges the oil L to the lower chamber 23 by reducing its volume in order to absorb the increase in volume of the upper communication chamber 147 . The lower communication chamber 149 increases in volume to absorb the decrease in the volume of the upper communication chamber 147 and allows the oil L to flow in from the lower chamber 23 . Conversely, the upper chamber communication chamber 147 reduces its volume to absorb the increase in volume of the lower chamber communication chamber 149 and discharges the oil L to the upper chamber 22 side. The upper chamber communication chamber 147 increases in volume to absorb the decrease in volume of the lower chamber communication chamber 149 and allows the oil L to flow in from the upper chamber 22 side. As described above, the deformation of the disk valve 100 is prevented from being hindered by the oil L in the upper communication chamber 147 and the lower communication chamber 149 .

As shown in FIG. 2 , a plurality of passage grooves 225 of the valve seat member 109 are provided facing the lower chamber 23 . The plurality of second passage portions 162 always communicate with the lower chamber 23 via passages in the plurality of passage grooves 225 . As shown in FIG. 3, the passage in the hole 415 formed in the disc spring 116 and the passage in the passage hole 126 formed in the bottom 122 of the case member 95 correspond to one of the upper chamber 22 and the lower chamber 23. is always communicated with the lower chamber 23 .

A radial passage 222 in a passage groove 221 that opens to the first passage portion 161 of the valve seat member 109 always communicates with the upper chamber communication chamber 147 . The radial passage 222 always communicates the inside of the upper chamber communication chamber 147 with the passage inside the large diameter hole portion 133 of the valve seat member 109 and the piston rod passage portion 51 of the piston rod 25 .

As shown in FIG. 2 , the sub-valve 107 is disk-shaped and has an outer diameter equal to the outer diameter of the valve seat portion 135 of the valve seat member 109 . The sub-valve 107 is always in contact with the inner seat portion 134 and can be seated and removed from the valve seat portion 135 . The sub-valve 107 closes all the second passage portions 162 by being seated on the entire valve seat portion 135 . Further, the sub-valve 107 closes the second passage portion 162 inside the valve seat forming portion 201 by being seated on the entire valve seat forming portion 201 of the valve seat portion 135 . The spring member 105 brings the sub-valve 107 into contact with the valve seat portion 135 of the valve seat member 109 . The sub-valve 107 is seated on the valve seat portion 135 by the biasing force of the spring member 105 to close the second passage portion 162 .

A sub-valve 107 that can be seated on and removed from the valve seat portion 135 is provided in a case chamber 146 . The sub-valve 107 is separated from the valve seat portion 135 within the case chamber 146 . Then, the sub-valve 107 allows the plurality of second passage portions 162 and the upper chamber communication chamber 147 to communicate with each other. As a result, the lower chamber 23 communicates with the upper chamber 22 . At this time, the sub-valve 107 suppresses the flow of the oil L between itself and the valve seat portion 135 to generate a damping force. The sub-valve 107 is an inflow valve that opens when the oil L flows from the lower chamber 23 to the upper chamber communication chamber 147 side through the plurality of second passages 162 . The sub-valve 107 is a check valve that regulates the outflow of the oil L from the upper chamber communication chamber 147 to the lower chamber 23 via the second passage portion 162 . Here, the passage hole 216 forming the first passage portion 161 opens outside the range of the valve seat portion 135 of the valve seat member 109 . Therefore, the passage hole 216 always communicates with the upper chamber communication chamber 147 regardless of the sub-valve 107 seated on the valve seat portion 135 .

The passages in the plurality of passage grooves 225, the plurality of second passage portions 162, the passages between the sub-valve 107 and the valve seat portion 135 appearing when the valve is opened, the upper chamber communication chamber 147, and the passages of the valve seat member 109. A radial passage 222 in the groove 221, a passage in the large-diameter hole portion 133 of the valve seat member 109, a passage in the piston rod passage portion 51 of the piston rod 25 and the large-diameter hole portion 46 of the piston 21, and the disk 82. The passage within the notch 90 , the passage within the annular groove 55 of the piston 21 and the plurality of passage holes 38 constitute a second passage 172 . In the second passage 172, when the piston 21 moves toward the lower chamber 23, the oil L flows from the lower chamber 23 on the upstream side in the cylinder 4 to the upper chamber 22 on the downstream side. In the second passage 172, the oil L flows from the lower chamber 23 on the upstream side toward the upper chamber 22 on the downstream side during the movement of the piston 21 toward the lower chamber 23 side, that is, the compression stroke. The second passage 172 serves as a contraction-side passage. The second passage 172 on the contraction side is provided separately from the first passage 72 on the contraction side. The second passageway 172 is parallel to the first passageway 72 .

The passage in the passage hole 126, the passage in the hole 415, and the lower chamber communication chamber 149 shown in FIG. 3 constitute a third passage 511 on the contraction side. The third passage 511 always communicates with the lower chamber 23 . The third passage 511 on the contraction side is provided separately from the second passage 172 shown in FIG. 2 on the contraction side. The third passage 511 is arranged in parallel with the second passage 172 .

As shown in FIG. 3, disk 104 is thicker and stiffer than subvalve 107 . The disk 104 abuts on the sub-valve 107 when the sub-valve 107 is deformed, and suppresses further deformation of the sub-valve 107 . The disc 104 abuts against the disc valve 100 when the disc valve 100 is deformed, and suppresses further deformation of the disc valve 100 .

The sub-valve 107, the valve seat member 109 including the valve seat portion 135, the discs 104 and 106, and the spring member 105 shown in FIG. The second damping force generating mechanism 173 is provided on the piston rod 25 . The second damping force generating mechanism 173 is provided in the second passage 172 on the compression side. The second damping force generating mechanism 173 opens and closes the second passage 172 to suppress the flow of the oil L from the second passage 172 to the upper chamber 22 to generate damping force. The second damping force generating mechanism 173 is a compression side second damping force generating mechanism. The third passage 511 is provided in parallel with the second damping force generating mechanism 173 on the compression side.

The valve seat portion 135 of the second damping force generating mechanism 173 is provided on the valve seat member 109 . The second damping force generating mechanism 173 is arranged separately from the first damping force generating mechanism 42 that generates damping force in the same contraction stroke. The sub-valve 107 constituting the compression-side second damping force generating mechanism 173 is a compression-side sub-valve.

As shown in FIG. 3, a passage inside a passage hole 126 is formed in the bottom portion 122 of the case member 95 . A passage in the passage hole 126 communicates the inside and the outside of the case member 95 . The disk spring 116 is provided so that one axial end surface side contacts the outer peripheral side of the passage in the passage hole 126 of the case member 95 . A deflectable disk valve 100 is provided so as to abut on the other axial end surface side of the disc spring 116 .

As shown in FIG. 2 , in the second passage 172 , the passage in the notch 90 of the disc 82 becomes the orifice 175 . The orifice 175 is arranged downstream of the sub-valve 107 in the flow of the oil L when the sub-valve 107 is opened and the oil L flows through the second passage 172 . The orifice 175 may be arranged upstream of the sub-valve 107 in the flow of the oil L when the sub-valve 107 is opened and the oil L flows through the second passage 172 . The orifice 175 is formed by notching the disk 82 of the first damping force generating mechanism 41 that contacts the piston 21 .

The second damping force generating mechanism 173 on the compression side has no fixed orifice formed in either the valve seat portion 135 or the sub-valve 107 abutting thereon. The fixed orifice allows communication between the upper chamber 22 and the lower chamber 23 even when the valve seat portion 135 and the sub-valve 107 are in contact with each other. That is, the compression-side second damping force generating mechanism 173 does not allow the upper chamber 22 and the lower chamber 23 to communicate with each other when the valve seat portion 135 and the sub-valve 107 are in contact with each other. In other words, the second passage 172 does not have a fixed orifice that constantly communicates between the upper chamber 22 and the lower chamber 23 . The second passage 172 is not a passage that always communicates between the upper chamber 22 and the lower chamber 23 .

The contraction-side second passage 172 that allows communication between the upper chamber 22 and the lower chamber 23 is arranged in parallel with the contraction-side first passage 72 that similarly allows communication between the upper chamber 22 and the lower chamber 23 . A first damping force generating mechanism 42 is provided in the first passage 72 . A second damping force generating mechanism 173 is provided in the second passage 172 . Therefore, both the first damping force generating mechanism 42 and the second damping force generating mechanism 173 on the compression side are arranged in parallel.

As shown in FIG. 3 , the sub-valve 110 is disc-shaped and has an outer diameter equal to the outer diameter of the valve seat portion 139 of the valve seat member 109 . The sub-valve 110 is always in contact with the inner seat portion 138 and can be seated and removed from the valve seat portion 139 . The sub-valve 110 is seated on the entire valve seat portion 139 . Then, the sub-valve 110 closes all the first passages 161 . Also, the sub-valve 110 is seated entirely on one of the valve seat forming portions 211 of the valve seat portion 139 . Then, the sub-valve 110 closes the first passage portion 161 inside the valve seat forming portion 211 . The sub-valve 110 can be a common component with the same shape as the sub-valve 107 .

The disc 111 is a common component having the same shape as the disc 106 . The outer diameter of the disk 111 is smaller than the outer diameter of the sub-valve 110 and slightly smaller than the outer diameter of the inner seat portion 138 .

The spring member 112 has a substrate portion 341 and a plurality of spring plate portions 342 . The substrate portion 341 has a perforated circular plate shape with a constant radial width over the entire circumference. The mounting shaft portion 28 is fitted to the inner peripheral portion of the substrate portion 341 . The plurality of spring plate portions 342 extend outward in the radial direction of the substrate portion 341 from equally spaced positions in the circumferential direction of the substrate portion 341 . The spring plate portion 342 is inclined with respect to the substrate portion 341 so as to separate from the substrate portion 341 in the axial direction of the substrate portion 341 toward the extension tip side. The spring member 112 contacts the disk 111 at the substrate portion 341 . The spring member 112 is attached to the attachment shaft portion 28 so that the spring plate portion 342 extends from the substrate portion 341 toward the sub-valve 110 in the axial direction of the substrate portion 341 . A plurality of spring plate portions 342 of the spring member 112 abut against the sub-valve 110 . The spring member 112 brings the sub-valve 110 into contact with the valve seat portion 139 of the valve seat member 109 . The sub-valve 110 is seated on the valve seat portion 139 by the biasing force of the spring member 112 to close the first passage portion 161 .

The sub-valve 110 is provided inside the lower chamber 23 . The sub-valve 110 allows the upper chamber 22 and the upper chamber communication chamber 147 to communicate with the lower chamber 23 by being separated from the valve seat portion 139 . At this time, the sub-valve 110 suppresses the flow of the oil L between itself and the valve seat portion 139 to generate a damping force. The sub-valve 110 is a discharge valve that opens when the oil L is discharged from the upper chamber 22 and the upper chamber communication chamber 147 to the lower chamber 23 through the plurality of first passages 161 of the valve seat member 109 . The sub-valve 110 is a check valve that regulates the inflow of the oil L from the lower chamber 23 into the upper chamber 22 and the upper chamber communication chamber 147 through the first passage portion 161 . Here, as shown in FIG. 2 , the passage hole 206 forming the second passage portion 162 opens outside the range of the valve seat portion 139 of the valve seat member 109 . Therefore, the passage hole 206 always communicates with the lower chamber 23 regardless of the sub-valve 110 seated on the valve seat portion 139 .

Passages in the plurality of passage holes 38 and the annular groove 55 of the piston 21, passages in the cutout portion 90 of the disk 82, passages in the large diameter hole portion 46 of the piston 21, and the piston rod passage portion 51 of the piston rod 25. and the passage in the large diameter hole portion 133 of the valve seat member 109, the radial direction passage 222 of the valve seat member 109, the plurality of first passage portions 161 of the valve seat member 109, the sub-valve 110 appearing when the valve is opened, and the valve A passage between the seat portions 139 constitutes a second passage 182 . In the second passage 182, when the piston 21 moves toward the upper chamber 22, the oil L flows from the upper chamber 22 on the upstream side in the cylinder 4 to the lower chamber 23 on the downstream side. The second passage 182 serves as an elongation-side passage through which the oil L flows from the upper chamber 22 on the upstream side toward the lower chamber 23 on the downstream side during the movement of the piston 21 toward the upper chamber 22 side, that is, the extension stroke. .

The second passage 182 on the extension side, which communicates between the upper chamber 22 and the lower chamber 23, includes a first passage 92, which is a passage on the extension side, which similarly communicates between the upper chamber 22 and the lower chamber 23, and the upper chamber 22 side. are parallel except for passages in the annular groove 55 and the plurality of passage holes 38 . The parallel portions of the first passage 92 and the second passage 182 are provided separately from each other.

The upper chamber communication chamber 147 forms a third extension passage 512 with the passage between the tubular portion 124 of the case member 95 and the sub-valve 107 . The extension-side third passage 512 similarly branches off from the extension-side second passage 182 and is provided separately from the second passage 182 .

The disc 113 has an outer diameter equal to that of the sub-valve 110 . Disk 113 is thicker and stiffer than sub-valve 110 . The disk 113 abuts on the sub-valve 110 when the sub-valve 110 is deformed, and suppresses further deformation of the sub-valve 110 . The annular member 114 has an outer diameter smaller than that of the disk 113 . The annular member 114 is a common component having the same shape as the annular member 69 .

The sub valve 110 , the valve seat member 109 including the valve seat portion 139 , the discs 111 and 113 and the spring member 112 constitute a second damping force generating mechanism 183 . The second damping force generating mechanism 183 is provided in the extension side second passage 182 and opens and closes the second passage 182 . The second damping force generating mechanism 183 suppresses the flow of the oil L from the second passage 182 to the lower chamber 23 to generate damping force. The second damping force generating mechanism 183 is a second damping force generating mechanism on the rebound side. The second damping force generating mechanism 183 is provided on the piston rod 25 and its valve seat portion 139 is provided on the valve seat member 109 . The second damping force generating mechanism 183 is arranged separately from the first damping force generating mechanism 41 that generates damping force in the same extension stroke. The sub-valve 110 that constitutes the extension-side second damping force generating mechanism 183 is an extension-side sub-valve. The third passage 512 is provided in parallel with the extension-side second damping force generating mechanism 183 .

As shown in FIG. 3, the disc valve 100, the valve seat disc 101, the disc spring 116, the disc 97, the bottom portion 122 of the case member 95, and the lower chamber communication chamber 149 make up the volume of the lower chamber communication chamber 149. A lower chamber volume variable mechanism 185 capable of changing is configured. The lower chamber volume variable mechanism 185 is provided in the contraction-side third passage 511 including the lower chamber communication chamber 149 . A lower chamber communication chamber 149 is provided between the disk valve 100 and the sub-valve 110 on the flow path via the lower chamber 23 , the passage in the passage hole 126 and the passage in the hole portion 415 .

In the lower chamber volume variable mechanism 185, the disc valve 100 and the valve seat disc 101 are integrally deformed and moved away from the bottom portion 122. As shown in FIG. Then, the lower chamber volume variable mechanism 185 changes so as to increase the volume of the lower chamber communication chamber 149 . At this time, if the disc valve 100 is maintained in contact with the disc spring 116 over the entire circumference, the space between the disc valve 100 and the outer tapered portion 403 of the disc spring 116 is closed. That is, when the disc valve 100 is deformed away from the bottom portion 122, if the disc valve 100 is maintained in contact with the disc spring 116 over the entire circumference, the communication between the lower chamber communication chamber 149 and the upper chamber communication chamber 147 is cut off. to maintain

In the lower chamber volume variable mechanism 185, the disc valve 100 and the valve seat disc 101 are integrally deformed and moved to approach the bottom portion 122. As shown in FIG. Then, the lower chamber volume variable mechanism 185 changes the volume of the lower chamber communication chamber 149 so as to decrease. At this time, the disk valve 100 is maintained in a state of contacting the disk spring 116 as a whole, and the space between the disk valve 100 and the outer tapered portion 403 of the disk spring 116 is closed.

As shown in FIG. 2 , the extension-side third passage 512 including the upper chamber communication chamber 147 communicating with the upper chamber 22 branches from the extension-side second passage 182 . The third passage 512 is provided separately from the second passage 182 . As shown in FIG. 3, the disc valve 100, the valve seat disc 101, the disc spring 116, the discs 102, 104, 106, the spring member 105, the sub-valve 107, the case member 95, and the upper chamber communication chamber 147 constitutes the upper chamber volume variable mechanism 186 . The upper chamber volume variable mechanism 186 can change the volume of the upper chamber communication chamber 147 . The upper chamber volume variable mechanism 186 is provided in the extension side third passage 512 including the upper chamber communication chamber 147 . An upper chamber communication chamber 147 is provided between the disk valve 100 and the sub-valve 107 on the flow path.

In upper chamber volume variable mechanism 186 , disk valve 100 and valve seat disk 101 are integrally deformed and moved away from disk 104 . Then, the upper chamber volume variable mechanism 186 changes so as to increase the volume of the upper chamber communication chamber 147 . At this time, the valve seat disk 101 blocks the passage in the communication hole 501 of the disk valve 100 if the state of contacting the disk valve 100 as a whole is maintained. That is, the disconnection state between the lower chamber communication chamber 149 and the upper chamber communication chamber 147 is maintained.

Also, the upper chamber volume variable mechanism 186 deforms and moves so that the disc valve 100 and the valve seat disc 101 approach the disc 104 . Then, the upper chamber volume variable mechanism 186 changes the volume of the upper chamber communication chamber 147 so as to decrease. At this time, the valve seat disk 101 is kept in contact with the disk valve 100 as a whole and blocks the passage in the communication hole 501 of the disk valve 100 .

The disc valve 100, the valve seat disc 101 and the disc spring 116 are shared by the lower chamber volume variable mechanism 185 and the upper chamber volume variable mechanism 186. As shown in FIG. A variable lower chamber volume mechanism 185 including the lower chamber communication chamber 149 and a variable upper chamber volume mechanism 186 including the upper chamber communication chamber 147 constitute an accumulator 190 that stores oil as a working fluid. The accumulator 190 has the disc valve 100 , the disc spring 116 and the case member 95 . Accumulator 190 is provided on piston rod 25 . The accumulator 190 is arranged inside the shock absorber 1 separately from the second damping force generating mechanisms 173 and 183 . The disc valve 100 of the accumulator 190 deforms before the second damping force generation mechanism 183 opens during the extension stroke, and deforms before the second damping force generation mechanism 173 opens during the compression stroke. The accumulator 190 is provided in the third passage 511 on the contraction side. The accumulator 190 is provided in the extension-side third passage 512 . A disc valve 100 that constitutes an accumulator 190 is also provided in the third passages 511 and 512 .

In the second passage 182 as well, the passage in the notch 90 of the disc 82 serves as the orifice 175 . The orifice 175 is common to the second passages 172,182. The orifice 175 is arranged upstream of the sub-valve 110 in the flow of the oil L when the sub-valve 110 opens and the oil L flows through the second passage 182 . The orifice 175 may be arranged downstream of the sub-valve 110 in the flow of the oil L when the sub-valve 110 opens and the oil L flows through the second passage 182 . The sub-valve 110 and the above-described sub-valve 107 are opened and closed independently.

The extension-side second damping force generating mechanism 183 has no fixed orifice formed in either the valve seat portion 139 or the sub-valve 110 abutting thereon. The fixed orifice allows communication between the upper chamber 22 and the lower chamber 23 even when the valve seat portion 139 and the sub-valve 110 are in contact with each other. That is, the extension-side second damping force generating mechanism 183 does not allow communication between the upper chamber 22 and the lower chamber 23 when the valve seat portion 139 and the sub-valve 110 are in contact with each other. In other words, the second passage 182 does not have a fixed orifice that constantly communicates between the upper chamber 22 and the lower chamber 23 . The second passage 182 is not a passage that always communicates between the upper chamber 22 and the lower chamber 23 . The annular member 114 and the disk 113 restrict the deformation of the sub-valve 110 in the opening direction beyond a specified limit.

In the shock absorber 1, the upper chamber 22 and the lower chamber 23 are composed of first damping force generating mechanisms 41 and 42 and a second damping force generating mechanism 41, 42 for the flow of the oil L in the axial direction at least within the range of the piston 21. Communication is only possible via mechanisms 173 , 183 and accumulator 190 . The shock absorber 1 is not provided with a fixed orifice on the passage of the oil liquid L, which constantly communicates the upper chamber 22 and the lower chamber 23 .

As described above, the second passage 182 and the first passage 92 are arranged in parallel except for passages within the annular groove 55 and the plurality of passage holes 38 . In parallel portions of the second passage 182 and the first passage 92, the first damping force generating mechanism 41 and the second damping force generating mechanism 183 are provided in the first passage 92 and the second passage 182, respectively. Therefore, both the first damping force generating mechanism 41 and the second damping force generating mechanism 183 on the extension side are arranged in parallel.

The second damping force generating mechanisms 173 and 183 include a valve seat member 109, a sub-valve 110 provided on one side of the valve seat member passage portion 160, a sub-valve 107 provided on the other side of the valve seat member passage portion 160, and a case member. 95 and. The valve seat member passage portion 160 is a portion of the second passages 172 and 182 provided in the valve seat member 109 . The case member 95 has a cylindrical shape with a bottom and is provided between the piston 21 and the valve seat member 109 in the second passages 172 and 182 . The valve seat member 109 is provided inside the case member 95 . The sub-valve 110 is provided on the lower chamber 23 side of the valve seat member 109 . The sub-valve 107 is provided within a case chamber 146 between the bottom portion 122 of the case member 95 and the valve seat member 109 .

As described above, the upper chamber volume varying mechanism 186 changes the volume of the upper chamber communication chamber 147 by deforming and moving the disk valve 100 away from the disk 104 to increase the volume of the upper chamber communication chamber 147 . At this time, the pressure difference between the upper chamber communication chamber 147 and the lower chamber communication chamber 149 may exceed a predetermined value while the second damping force generating mechanism 183 is open. Then, in the upper chamber volume varying mechanism 186, the disk valve 100 elastically deforms the outer tapered portion 403 of the disc spring 116 toward the bottom portion 122 while deforming the outer peripheral side thereof toward the bottom portion 122 side. As a result, the disc valve 100 is axially separated from the valve seat disc 101 . Then, the disc valve 100 allows the upper chamber communication chamber 147 and the lower chamber communication chamber 149 to communicate with each other through the passage in the communication hole 501 . A passage in the communication hole 501 and a passage between the disc valve 100 and the valve seat disc 101 are the fourth passage 521 . The fourth passage 521 communicates the upper chamber communication chamber 147 and the lower chamber communication chamber 149 in the extension stroke. The fourth passage 521 is an extension side passage. The fourth passage 521 is provided separately from the third passage 512 including the upper chamber communication chamber 147 . The fourth passageway 521 communicates in series with the third passageway 512 when open.

The disc valve 100 and valve seat disc 101 constitute a relief mechanism 522 . The relief mechanism 522 allows the oil L to flow from the upper communication chamber 147 to the lower communication chamber 149 via the fourth passage 521 . In other words, the relief mechanism 522 causes the oil L to flow from the upper chamber 22 to the lower chamber 23 . The relief mechanism 522 is an extension-side relief mechanism. The relief mechanism 522 is provided in the extension-side fourth passage 521 . The relief mechanism 522 is set to open after the second damping force generating mechanism 183 on the extension side opens.

The upper chamber volume variable mechanism 186 has a disc valve 100 and a disc spring 116 . The disc valve 100 is flexible and deforms before the second damping force generating mechanism 183 opens. The disk valve 100 is formed with a communication hole 501 that communicates between the upstream side and the downstream side from the inner peripheral end to the outer peripheral end. The disk spring 116 abuts on the end surface of the disc valve 100 to bias the disc valve 100 . The relief mechanism 522 is provided so as to be able to open and close the communication hole 501 of the disc valve 100 according to the deflection amount of the disc valve 100 .

The lower chamber volume variable mechanism 185 changes the volume of the lower chamber communication chamber 149 so as to increase the volume of the lower chamber communication chamber 149 by deforming and moving the disk valve 100 closer to the disk 104 . At this time, the pressure difference between the upper chamber communication chamber 147 and the lower chamber communication chamber 149 may exceed a predetermined value while the second damping force generating mechanism 173 is open. Then, in the lower chamber volume variable mechanism 185, the amount of deformation on the outer peripheral side of the disc valve 100 increases. As a result, the disc valve 100 is axially separated from the contact portion 416 of the disc spring 116 . Then, the disc valve 100 communicates with the lower chamber communication chamber 149 and the upper chamber communication chamber 147 through the conical spring 116 . In other words, the contact portion 416 of the disc spring 116 that contacts the end face of the disc valve 100 is at least partially separated from the end face of the disc valve 100 by the deflection amount of the disc valve 100 . A passage between the disc valve 100 and the disc spring 116 is the fourth passage 531 . The fourth passage 531 allows communication between the lower chamber communication chamber 149 and the upper chamber communication chamber 147 during the contraction stroke. The fourth passage 531 is a contraction-side passage. The fourth passage 531 is provided separately from the third passage 511 including the lower chamber communication chamber 149 . The fourth passageway 531 communicates in series with the third passageway 511 when open.

The disc valve 100 and the disc spring 116 constitute a relief mechanism 532 . The relief mechanism 532 allows the oil L to flow from the lower communication chamber 149 to the upper communication chamber 147 via the fourth passage 531 . In other words, the relief mechanism 532 causes the oil L to flow from the lower chamber 23 to the upper chamber 22 . The relief mechanism 532 is a compression-side relief mechanism. The relief mechanism 532 is provided in the fourth passage 531 on the contraction side. The relief mechanism 532 is set to open after the second damping force generating mechanism 173 on the compression side opens.

As shown in FIG. 2 , the inner peripheral side of the main valve 71 is clamped between the discs 63 and 67 while being assembled to the piston rod 25 . At the same time, the main valve 71 abuts on the valve seat portion 50 of the piston 21 over the entire circumference. In this state, the inner peripheral side of the main valve 91 is clamped between the discs 83 and 87 . At the same time, the main valve 91 abuts on the valve seat portion 48 of the piston 21 over the entire circumference.

In this state, the sub-valve 107 is clamped on the inner peripheral side between the inner seat portion 134 of the valve seat member 109 and the disc 106 . At the same time, the sub-valve 107 abuts on the valve seat portion 135 of the valve seat member 109 over the entire circumference. In this state, the sub-valve 110 is clamped on the inner peripheral side between the inner seat portion 138 of the valve seat member 109 and the disc 111 . At the same time, the sub-valve 110 abuts on the valve seat portion 139 of the valve seat member 109 over the entire circumference.

Further, in this state, as shown in FIG. 3, the disc valve 100 is clamped on the inner peripheral side between the disc 97 and the disc 102 together with the valve seat disc 101 . At the same time, the disk valve 100 contacts the contact portion 416 of the disc spring 116 over the entire circumference. At this time, the disc valve 100 is elastically deformed in a tapered shape so that the radially outer portion of the disc valve 100 separates from the bottom portion 122 in the axial direction toward the radially outer side. At this time, the outer tapered portion 403 of the disc spring 116 elastically deforms and contacts the disk valve 100 at the contact portion 416 over the entire circumference. In this state, the valve seat disc 101 also follows the shape of the disc valve 100 and elastically deforms into a tapered shape so that the radially outer portion of the disc 102 moves away from the bottom portion 122 in the axial direction toward the radially outer side. .

As shown in FIG. 1, a liquid passage 251 and a liquid passage 252 are formed through the valve body 12 in the axial direction. The liquid passages 251 and 252 are capable of communicating the lower chamber 23 and the reservoir chamber 5 . The base valve 15 has a damping force generating mechanism 255 on the bottom member 9 side in the axial direction of the valve body 12 . The damping force generating mechanism 255 can open and close the liquid passage 251 . The damping force generation mechanism 255 is a compression side damping force generation mechanism. The base valve 15 also has a damping force generating mechanism 256 on the opposite side of the valve body 12 from the bottom member 9 in the axial direction. The damping force generating mechanism 256 can open and close the liquid passage 252 . The damping force generating mechanism 256 is a damping force generating mechanism on the rebound side.

When the piston rod 25 moves to the contraction side and the piston 21 moves in the direction to narrow the lower chamber 23, the pressure in the lower chamber 23 may become higher than the pressure in the reservoir chamber 5 by a predetermined value or more. Then, in the base valve 15 , the damping force generating mechanism 255 opens the liquid passage 251 to allow the oil L in the lower chamber 23 to flow into the reservoir chamber 5 . The damping force generating mechanism 255 generates a damping force at that time. In other words, when the piston rod 25 moves to the contraction side to move the piston 21 , the oil L flows into the reservoir chamber 5 in the fluid passage 251 . The damping force generation mechanism 255 is a compression side damping force generation mechanism. The damping force generating mechanism 255 does not block the flow of the oil L in the liquid passage 252 .

When the piston rod 25 moves to the extension side and the piston 21 moves to the upper chamber 22 side, the pressure in the lower chamber 23 becomes lower than the pressure in the reservoir chamber 5 . Then, in the base valve 15 , the damping force generating mechanism 256 opens the fluid passage 252 to allow the fluid L in the reservoir chamber 5 to flow to the lower chamber 23 . At that time, the damping force generating mechanism 256 generates a damping force. In other words, when the piston rod 25 moves to the extension side to move the piston 21 , the oil L flows into the lower chamber 23 in the liquid passage 252 . The damping force generation mechanism 256 is a rebound damping force generation mechanism. The damping force generating mechanism 256 does not block the flow of the oil L in the liquid passage 251 . The damping force generating mechanism 256 may be a suction valve that allows the oil L to flow from the reservoir chamber 5 into the lower chamber 23 without substantially generating a damping force.

<Operation>
As shown in FIG. 2, of the first damping force generating mechanism 41 and the second damping force generating mechanism 183 on the rebound side, the main valve 91 of the first damping force generating mechanism 41 The rigidity is higher than that of the sub-valve 110 of , and the valve opening pressure is higher than that of the sub-valve 110 . Therefore, in the extension stroke, the second damping force generating mechanism 183 is opened while the first damping force generating mechanism 41 is closed in an extremely low speed region in which the piston speed is lower than a predetermined value. In other words, the second damping force generating mechanism 183 opens to generate damping force when the piston speed is lower than that of the first damping force generating mechanism 41 . Also, in the normal speed region where the piston speed is equal to or higher than this predetermined value, both the first damping force generating mechanism 41 and the second damping force generating mechanism 183 are opened. The sub-valve 110 is a very low speed valve that opens in a region where the piston speed is very low to generate a damping force.

That is, in the extension stroke, the pressure in the upper chamber 22 increases and the pressure in the lower chamber 23 decreases as the piston 21 moves toward the upper chamber 22 . Here, none of the first damping force generating mechanisms 41 and 42 and the second damping force generating mechanisms 173 and 183 has a fixed orifice that always communicates the upper chamber 22 and the lower chamber 23 . Therefore, the oil L in the upper chamber 22 flows through the passages in the plurality of passage holes 38 and the annular groove 55 of the piston 21, the orifice 175, the passages in the large-diameter hole 46 of the piston 21, and the piston of the piston rod 25. It flows into the upper chamber communication chamber 147 through the rod passage portion 51 , passages in the large-diameter hole portion 133 of the valve seat member 109 , the radial direction passage 222 of the valve seat member 109 , and the third passage 512 . As a result, the upper chamber communication chamber 147 is pressurized. Therefore, before the second damping force generating mechanism 183 opens, the upper chamber volume variable mechanism 186 has a radially inner portion of the contact position of the disc spring 116 of the disc valve 100 against the outer tapered portion 403 . , bends toward the bottom portion 122 . As a result, the disc valve 100 increases the capacity of the upper communication chamber 147 . As a result, the upper chamber volume variable mechanism 186 suppresses an increase in pressure in the upper chamber communication chamber 147 . At this time, the valve seat disk 101 deforms following the disk valve 100 to keep the fourth passage 521 closed. At this time, since the disc valve 100 bends and moves toward the bottom portion 122 , the lower chamber volume varying mechanism 185 reduces the volume of the lower chamber communication chamber 149 .

Here, in the extension stroke of the shock absorber 1 at the time of low frequency input (at the time of large amplitude vibration), the amount of the oil L flowing from the upper chamber 22 to the upper chamber communication chamber 147 as described above becomes large. Therefore, the disk valve 100 is greatly deformed. When the amount of deformation of the disk valve 100 increases, the reaction force due to the support rigidity of the clamped inner peripheral side increases, and the amount of deformation is limited. As a result, the pressure in the upper communication chamber 147 increases. As a result, the pressure in the second passage 182 rises to the point where the second damping force generating mechanism 183 opens.

At this time, none of the first damping force generating mechanisms 41 and 42 and the second damping force generating mechanisms 173 and 183 has a fixed orifice that allows the upper chamber 22 and the lower chamber 23 to always communicate with each other. Therefore, the damping force rises sharply in the extension stroke when the piston speed is less than the first predetermined value at which the second damping force generating mechanism 183 opens. Further, in a region where the piston speed is higher than the first predetermined value and lower than the second predetermined value, which is higher than the first predetermined value and lower than the second predetermined value, the first damping force generating mechanism 41 closes the valve. In this state, the second damping force generating mechanism 183 opens.

That is, the sub-valve 110 is separated from the valve seat portion 139, and the upper chamber 22 and the lower chamber 23 are communicated with each other through the second passage 182 on the expansion side. Therefore, the oil L in the upper chamber 22 flows through the passages in the plurality of passage holes 38 and the annular groove 55 of the piston 21, the orifice 175, the passages in the large-diameter hole 46 of the piston 21, and the piston of the piston rod 25. The rod passage portion 51 and the passage in the large diameter hole portion 133 of the valve seat member 109, the radial direction passage 222 of the valve seat member 109, the first passage portion 161 in the valve seat member 109, the sub-valve 110 and the valve seat portion 139 into the lower chamber 23. As a result, a damping force with valve characteristics (a characteristic in which the damping force is substantially proportional to the piston speed) can be obtained even in an extremely low speed range in which the piston speed is lower than the second predetermined value.

Further, a relief mechanism 522 is provided that opens after the second damping force generating mechanism 183 opens in the extension stroke. Therefore, when the pressure in the upper chamber communication chamber 147 increases in the normal speed region in which the piston speed is equal to or higher than the second predetermined value, the relief mechanism 522 moves to the fourth passage while the second damping force generating mechanism 183 remains open. 521 is opened to allow the oil L in the upper chamber communication chamber 147 to flow to the lower chamber 23 . After that, the first damping force generating mechanism 41 is opened while the second damping force generating mechanism 183 and the relief mechanism 522 remain open. That is, the sub-valve 110 is separated from the valve seat portion 139 as described above, and the oil L flows from the upper chamber 22 to the lower chamber 23 through the second passage 182 on the extension side. After that, while the second damping force generating mechanism 183 remains open, the relief mechanism 522 opens the fourth passage 521, and the oil L flows from the upper chamber 22 to the lower chamber 23 through the fourth passage 521. . At this time, the orifice 175 provided on the downstream side of the main valve 91 in the second passage 182 restricts the flow of the oil L. As a result, the pressure applied to the main valve 91 increases, the pressure difference increases, the main valve 91 is separated from the valve seat portion 48, and the oil flows from the upper chamber 22 to the lower chamber 23 through the first passage 92 on the extension side. Run L. Therefore, the oil L in the upper chamber 22 flows into the lower chamber 23 through passages in the plurality of passage holes 38 and the annular groove 55 and through passages between the main valve 91 and the valve seat portion 48 .

As a result, even in the normal speed region where the piston speed is equal to or higher than the second predetermined value, a damping force with valve characteristics (the damping force is approximately proportional to the piston speed) can be obtained. The increase rate of the rebound damping force with respect to the increase in the piston speed in the normal speed region is lower than the increase rate of the rebound damping force with respect to the increase in the piston speed in the extremely low speed region. In other words, the slope of the increase rate of the damping force on the extension side with respect to the increase in the piston speed in the normal speed region can be flatter than in the extremely low speed region.

Here, when the disc valve 100 constituting the accumulator 190 and the relief mechanism 522 largely deforms toward the bottom portion 122 side of the case member 95, the outer tapered portion 403 of the coned disc spring 116 deforms to increase the taper to follow. At this time, the outer tapered portion 403 abuts against the inner surface 123a of the intermediate tapered portion 123 of the case member 95, thereby suppressing deformation that causes the tapering to increase any further. As a result, the inner surface 123 a of the intermediate tapered portion 123 of the case member 95 prevents the contact portion 416 of the disc spring 116 from being displaced toward the bottom surface 122 a of the bottom portion 122 from the main portion 417 . Therefore, in the disc spring 116, the outer tapered portion 403 can be prevented from being deformed such that the outer peripheral side is positioned closer to the bottom portion 122 than the inner peripheral side. In other words, in the disc spring 116, it is possible to prevent the outer tapered portion 403 from becoming an inverted shape in the axial direction with respect to the normal shape.

In the extension stroke, the differential pressure between the upper chamber 22 and the lower chamber 23 is larger in the normal speed region where the piston speed is equal to or higher than the second predetermined value than in the low speed region where the pressure difference between the upper chamber 22 and the lower chamber 23 is equal to or higher than the first predetermined value and less than the second predetermined value. The first passageway 92 is not constricted by an orifice. Therefore, when the main valve 91 is opened, the oil L can flow through the first passage 92 at a large flow rate. In addition to this, the second passage 182 is throttled by the orifice 175, and the relief mechanism 522 opens the fourth passage 521 to allow the oil L in the upper chamber communication chamber 147 to flow to the lower chamber 23, thereby deforming the sub-valve 110. can be suppressed.

Also, at this time, pressures in opposite directions are applied to the sub-valve 107 in the closed state from the lower chamber 23 and the upper chamber communication chamber 147 . An orifice 175 is formed upstream of the sub-valve 107 in the second passage 182 . Therefore, even if the differential pressure between the upper chamber 22 and the lower chamber 23 increases, the pressure rise in the upper chamber communication chamber 147 is gentler than the pressure rise in the upper chamber 22 . In addition to this, the relief mechanism 522 opens the fourth passage 521 to allow the oil L in the upper chamber communication chamber 147 to flow into the lower chamber 23, thereby increasing the pressure difference between the upper chamber communication chamber 147 and the lower chamber 23. suppress Therefore, it is possible to suppress an increase in the pressure difference between the upper chamber communication chamber 147 and the lower chamber 23 which the sub-valve 107 in the closed state receives. As a result, it is possible to suppress the application of a large back pressure to the sub-valve 107 from the upper chamber communication chamber 147 side toward the lower chamber 23 side.

The shock absorber 1 is provided with parallel passages of the first passage 92 and the second passage 182 through which the oil L flows from the upper chamber 22 to the lower chamber 23 during the extension stroke. The shock absorber 1 has a main valve 91 and a sub-valve 110 that operate in the extension stroke in parallel. Orifice 175 is connected in series with subvalve 110 .

As described above, in the extension stroke, in the normal speed region where the piston speed is equal to or higher than the second predetermined value, the main valve 91 is opened to allow the oil L to flow through the first passage 92 at a large flow rate. . As a result, the flow rate through the passage between the sub-valve 110 and the valve seat portion 139 is reduced. Therefore, for example, when the piston speed is in the normal speed region (more than the second predetermined value), it is possible to reduce the increase rate of the damping force with respect to the increase in the piston speed. In other words, the slope of the increase rate of the extension-side damping force with respect to the increase in piston speed in the normal speed region (more than the second predetermined value) can be flatter than in the extremely low speed region (less than the second predetermined value). Thereby, the degree of freedom in design can be expanded.

During the extension stroke during high frequency input (during small amplitude vibration) in which a frequency higher than that during low frequency input is input to the damper 1, the amount of oil L flowing from the upper chamber 22 to the upper chamber communication chamber 147 is is small. Therefore, the deformation of the disc valve 100 is small, and the upper chamber volume variable mechanism 186 can absorb the volume of the oil L flowing into the upper chamber communication chamber 147 by the amount of deflection of the disc valve 100 . Therefore, the pressure in the upper communication chamber 147 is reduced. Therefore, when the extremely low-speed damping force rises, the state is as if the disk valve 100 were not present. In other words, when the extremely low-speed damping force rises, the upper chamber communication chamber 147 always communicates with the lower chamber 23 through the passage in the hole portion 415 of the disc spring 116 and the passage in the passage hole 126 of the case member 95. 2 It is possible to achieve the same state as the structure without the damping force generating mechanism 183 .

Therefore, in the elongation stroke at the time of high frequency input, the rise of the extremely low-speed damping force is gentler than that at the time of low frequency input or the conventional damping force characteristic. In other words, when the frequency of the piston 21 exceeds a predetermined frequency in the extension stroke, the upper chamber volume variable mechanism 186 including the disc valve 100 limits the flow of the oil L to the sub-valve 110 of the second damping force generating mechanism 183. do. It should be noted that the change in damping force (inclination of damping force with respect to piston speed) until the second damping force generating mechanism 183 opens can be adjusted by changing the rigidity (plate thickness, etc.) of the disc valve 100 .

Here, in the extension stroke, the damping force characteristics of the damping force generating mechanism 256 are also combined.

Of the first damping force generating mechanism 42 and the second damping force generating mechanism 173 on the compression side, the main valve 71 of the first damping force generating mechanism 42 has higher rigidity than the sub valve 107 of the second damping force generating mechanism 173. High valve opening pressure. Therefore, in the compression stroke, the second damping force generating mechanism 173 is opened while the first damping force generating mechanism 42 is closed in a very low speed region in which the piston speed is lower than a predetermined value. In other words, the second damping force generating mechanism 173 opens to generate damping force when the piston speed is lower than that of the first damping force generating mechanism 42 . In the normal speed region where the piston speed is equal to or higher than this predetermined value, both the first damping force generating mechanism 42 and the second damping force generating mechanism 173 are opened. The sub-valve 107 is a very low speed valve that opens in a region where the piston speed is very low to generate a damping force.

That is, in the compression stroke, the pressure in the lower chamber 23 increases and the pressure in the upper chamber 22 decreases as the piston 21 moves toward the lower chamber 23 side. Here, none of the first damping force generating mechanisms 41, 42 and the second damping force generating mechanisms 173, 183 has a fixed orifice that always communicates the lower chamber 23 and the upper chamber 22 with each other. Therefore, the oil L in the lower chamber 23 flows into the lower chamber communication chamber 149 through the passage in the passage hole 126 of the case member 95 and the passage in the hole portion 415 of the disc spring 116 . As a result, the lower communication chamber 149 is pressurized. Therefore, in the lower chamber volume variable mechanism 185, the disk valve 100 bends toward the disk 104 before the second damping force generating mechanism 173 opens. As a result, the disc valve 100 increases the capacity of the lower communication chamber 149 . As a result, the lower chamber volume variable mechanism 185 suppresses an increase in pressure in the lower chamber communication chamber 149 . At this time, the valve seat disk 101 deforms following the disk valve 100 to keep the fourth passage 521 closed. At this time, since the disk valve 100 bends and moves toward the disk 104 , the upper chamber volume varying mechanism 186 reduces the volume of the upper chamber communication chamber 147 .

Here, in the contraction stroke of the shock absorber 1 at the time of low frequency input (at the time of large amplitude vibration), the amount of the oil L flowing from the lower chamber 23 to the lower chamber communication chamber 149 as described above becomes large. Therefore, the disk valve 100 is greatly deformed. When the amount of deformation of the disk valve 100 increases, the reaction force due to the support rigidity of the clamped inner peripheral side increases, and the amount of deformation is limited. As a result, the pressure in the lower communication chamber 149 increases. As a result, the pressure in the second passage 172 increases to the point where the second damping force generating mechanism 173 opens.

At this time, none of the first damping force generating mechanisms 41, 42 and the second damping force generating mechanisms 173, 183 has a fixed orifice that always communicates the lower chamber 23 and the upper chamber 22 with each other. Therefore, the damping force rises sharply in the compression stroke when the piston speed is less than the third predetermined value at which the second damping force generating mechanism 173 opens. In addition, in a region where the piston speed is higher than the third predetermined value and lower than the fourth predetermined value, which is higher than the third predetermined value and lower than the fourth predetermined value, the first damping force generating mechanism 42 closes the valve. In this state, the second damping force generating mechanism 173 opens.

That is, the sub-valve 107 is separated from the valve seat portion 135 to allow communication between the lower chamber 23 and the upper chamber 22 through the second passage 172 on the contraction side. Therefore, the oil L in the lower chamber 23 flows through the second passage portion 162 in the valve seat member 109, the passage between the sub-valve 107 and the valve seat portion 135, the upper chamber communication chamber 147, and the diameter of the valve seat member 109. The direction passage 222, the passage in the large diameter hole portion 133 of the valve seat member 109, the piston rod passage portion 51 of the piston rod 25, the passage in the large diameter hole portion 46 of the piston 21, the orifice 175, and the piston 21 and passages in the plurality of passage holes 38 and in the annular groove 55 to the upper chamber 22 . As a result, even in an extremely low speed region in which the piston speed is lower than the fourth predetermined value, a damping force with a valve characteristic (a characteristic in which the damping force is substantially proportional to the piston speed) can be obtained.

Further, a relief mechanism 532 is provided that opens after the second damping force generating mechanism 173 opens in the compression stroke. Therefore, in the normal speed range where the piston speed is equal to or higher than the fourth predetermined value, when the pressure in the lower chamber communication chamber 149 increases, the relief mechanism 532 moves to the fourth passage while the second damping force generating mechanism 173 remains open. 531 is opened to allow the oil L in the lower chamber 23 and the lower chamber communication chamber 149 to flow to the upper chamber 22 via the upper chamber communication chamber 147 . After that, the first damping force generating mechanism 42 is opened while the second damping force generating mechanism 173 and the relief mechanism 532 remain open. That is, the sub-valve 107 is separated from the valve seat portion 135 as described above, and the oil L flows from the lower chamber 23 to the upper chamber 22 through the second passage 172 on the contraction side. After that, the relief mechanism 532 opens the fourth passage 531 while the second damping force generating mechanism 173 remains open, and the oil L flows from the lower chamber 23 to the upper chamber 22 through the fourth passage 531. . At this time, the flow of the oil L is throttled by the orifice 175 provided downstream of the sub-valve 107 and the relief mechanism 532 in the second passage 172 . As a result, the pressure applied to the main valve 71 increases and the differential pressure increases. Then, the main valve 71 is separated from the valve seat portion 50, and the oil L flows from the lower chamber 23 to the upper chamber 22 through the first passage 72 on the contraction side. Therefore, the oil L in the lower chamber 23 flows into the upper chamber 22 through passages in the plurality of passage holes 39 and the annular groove 56 and passages between the main valve 71 and the valve seat portion 50 .

As a result, even in the normal speed region where the piston speed is equal to or higher than the fourth predetermined value, a damping force with valve characteristics (the damping force is approximately proportional to the piston speed) can be obtained. The increase rate of the compression damping force with respect to the increase in piston speed in the normal speed region is lower than the increase rate of the compression damping force with respect to the increase in piston speed in the extremely low speed region. In other words, the slope of the increase rate of the damping force on the extension side with respect to the increase in the piston speed in the normal speed region can be flatter than in the extremely low speed region.

Here, in the compression stroke, the pressure difference between the lower chamber 23 and the upper chamber 22 is greater in the normal speed region where the piston speed is equal to or higher than the fourth predetermined value than in the low speed region where the piston speed is greater than or equal to the third predetermined value and less than the fourth predetermined value. Become. At this time, the first passage 72 is not constricted by the orifice. Therefore, when the main valve 71 is opened, the oil L can flow through the first passage 72 at a large flow rate. This, the second passage 172 is throttled by the orifice 175, and the relief mechanism 532 opens the fourth passage 531 to allow the oil L in the lower chamber 23 and the lower chamber communication chamber 149 to flow to the upper chamber communication chamber 147. Therefore, deformation of the sub-valve 107 can be suppressed.

Also, at this time, pressures are applied to the sub-valve 110 in the closed state from the lower chamber 23 and the upper chamber communication chamber 147 in opposite directions. Even if the differential pressure between the lower chamber 23 and the upper chamber 22 increases, the orifice 175 is formed downstream of the sub-valve 110 in the second passage 172 and the relief mechanism 532 opens the fourth passage 531. , and flow the oil L in the lower chamber 23 and the lower chamber communication chamber 149 to the upper chamber communication chamber 147, thereby suppressing the pressure difference between the lower chamber 23 and the upper chamber communication chamber 147 from increasing. Therefore, it is possible to suppress an increase in the pressure difference between the lower chamber 23 and the upper chamber communication chamber 147 received by the sub-valve 110 in the closed state. As a result, it is possible to suppress the application of a large back pressure to the sub-valve 110 from the lower chamber 23 side toward the upper chamber communication chamber 147 side.

The shock absorber 1 is provided with a passage parallel to the first passage 72 and the second passage 172 for flowing the oil L from the lower chamber 23 to the upper chamber 22 in the contraction stroke. The shock absorber 1 has a main valve 71 and a sub-valve 107 arranged in parallel, which operate in the compression stroke. Orifice 175 is connected in series with subvalve 107 .

As described above, in the compression stroke, in the normal speed region where the piston speed is equal to or higher than the fourth predetermined value, the main valve 71 is opened to allow the oil L to flow through the first passage 72 at a large flow rate. . As a result, the flow rate through the passage between the sub-valve 107 and the valve seat portion 135 is reduced. Therefore, for example, it is possible to reduce the rate of increase of the damping force with respect to the increase in the piston speed when the piston speed is in the normal speed region (the fourth predetermined value or more). In other words, the slope of the rate of increase of the compression-side damping force with respect to the increase in piston speed in the normal speed region (above the fourth predetermined value) can be flatter than in the extremely low speed region (less than the fourth predetermined value). Thereby, the degree of freedom in design can be expanded.

In the compression stroke at the time of high frequency input (during small amplitude vibration) in which a frequency higher than that at the time of low frequency input is input to the damper 1, the inflow amount of the oil L from the lower chamber 23 to the lower chamber communication chamber 149 is is small. Therefore, deformation of the disc valve 100 is small. Therefore, deformation of the disk valve 100 is small. As a result, the lower chamber volume variable mechanism 185 can absorb the volume of the oil L flowing into the lower chamber communication chamber 149 with the deflection amount of the disc valve 100 . Therefore, the pressure in the lower communication chamber 149 is reduced. Therefore, when the extremely low-speed damping force rises, the state is as if the disc valve 100 were not present. In other words, when the extremely low-speed damping force rises, the lower chamber communication chamber 149 is always in communication with the upper chamber communication chamber 147, that is, it is possible to create a state similar to the structure without the second damping force generating mechanism 173. .

Therefore, in the compression stroke at the time of high frequency input, the rise of the extremely low-speed damping force becomes gentler than at the time of low frequency input or in comparison with the conventional damping force characteristic. In other words, when the frequency of the piston 21 exceeds a predetermined frequency, the lower chamber volume variable mechanism 185 including the disc valve 100 limits the flow of the oil L to the sub-valve 107 of the second damping force generating mechanism 173 . The change in damping force (inclination of damping force with respect to piston speed) until the second damping force generating mechanism 173 opens can be adjusted by changing the rigidity (thickness, etc.) of the disc valve 100 .

Here, in the contraction stroke, the damping force characteristics of the damping force generating mechanism 255 are also combined.

Patent Literature 1 described above describes a shock absorber having two valves that open in the same stroke. By adopting a structure having two valves that open in the same stroke in this way, one valve is opened in a region where the piston speed is lower than the other valve, and both valves are opened in a region where the piston speed is higher than this. A valve can be opened. By the way, some shock absorbers use disc springs. Since the disc spring is formed of a thin plate, it may be reversed in the axial direction when it is largely deformed in the axial direction.

The shock absorber 1 of the first embodiment has the accumulator 190 and the disc spring 116 forming the relief mechanism 522 as described above. When the accumulator 190 and the disk valve 100 constituting the relief mechanism 522 are largely deformed toward the bottom portion 122 of the case member 95, the outer taper portion 403 of the disc spring 116 is deformed to increase the taper and follow the deformation. At that time, even if the outer tapered portion 403 is greatly deformed, the intermediate tapered portion 123 of the case member 95 contacts the outer tapered portion 403 with the inner surface 123a, and the outer peripheral edge of the outer tapered portion 403 contacts. The portion 416 is prevented from being displaced from the main portion 417 toward the bottom surface 122 a of the bottom portion 122 . In this manner, the intermediate tapered portion 123 of the case member 95 prevents the outer tapered portion 403 of the disc spring 116 from deforming such that the outer peripheral side is positioned closer to the bottom portion 122 than the inner peripheral side. As a result, in the disc spring 116, the shape of the outer tapered portion 403 can be suppressed from being reversed in the axial direction with respect to the normal shape. As a result, it is possible to prevent a state in which the relief mechanism 532 is always open and good damping force characteristics of the second damping force generating mechanisms 173 and 183 cannot be obtained. Therefore, it becomes possible to suppress deterioration in function.

In addition, the inner surface 123a of the intermediate tapered portion 123 formed in the case member 95, which faces the contact portion 416 of the disc spring 116, extends over the entire circumference of the case member 95 to the end of the main portion 417 of the disc spring 116 on the side of the bottom surface 122a. It is formed so as to deform toward the contact portion 416 side rather than the portion. Therefore, it is possible to prevent the outer tapered portion 403 of the coned disc spring 116 from becoming axially reversed with respect to the normal shape with a simple structure without increasing the number of parts.

In addition, the inner surface 123a of the intermediate tapered portion 123 is partially formed in the circumferential direction of the case member 95 so as to deform more toward the contact portion 416 than the end of the main portion 417 of the disc spring 116 on the side of the bottom surface 122a. can be That is, at least a portion of the inner surface 123a of the intermediate taper portion 123 may be formed so as to deform more toward the contact portion 416 than the end portion of the main portion 417 of the disc spring 116 on the side of the bottom surface 122a.

[Second embodiment]
Next, the second embodiment will be described mainly based on FIG. 4, focusing on the differences from the first embodiment. Parts common to those of the first embodiment are denoted by the same designations and the same reference numerals.

As shown in FIG. 4, the shock absorber 1A of the second embodiment has a case member 95A that is partially different from the case member 95 instead of the case member 95. As shown in FIG. The buffer 1A also has a stopper member 601. As shown in FIG. The variable lower chamber volume mechanism 185A differs from the variable lower chamber volume mechanism 185 in that it has a case member 95A instead of the case member 95. As shown in FIG. The variable upper chamber volume mechanism 186A differs from the variable upper chamber volume mechanism 186 in that the case member 95 is replaced with a case member 95A. The accumulator 190A differs from the accumulator 190 in that it has a case member 95A instead of the case member 95. As shown in FIG.

Like the case member 95, the case member 95A is an integrally molded product having a bottomed tubular shape, and is formed, for example, by plastic working or cutting of a metal plate. The case member 95A has a bottom portion 122A and a cylindrical portion 124A. The bottom portion 122A has a constant thickness and a perforated circular plate shape with a constant radial width over the entire circumference. The tubular portion 124A extends from the outer peripheral edge portion of the bottom portion 122A to one axial side of the bottom portion 122A.

As with the bottom portion 122 , the bottom portion 122</b>A has the mounting shaft portion 28 of the piston rod 25 fitted to its inner peripheral portion. A plurality of passage holes 126A similar to the plurality of passage holes 126 are formed in the bottom portion 122A. The case member 95A abuts on the disk 87 with the bottom portion 122A positioned closer to the piston 21 than the cylindrical portion 124A. Like the case member 95, the case member 95A also abuts on the main valve 91 to restrict the deformation of the main valve 91 in the opening direction beyond a specified limit.

The bottom portion 122A has a recessed groove 602 formed at its radial end on the cylindrical portion 124A side. The bottom portion 122A has a planar bottom surface 122Aa on the cylindrical portion 124A side in the axial direction. The recessed groove 602 is recessed from the bottom surface 122Aa of the bottom portion 122A to the opposite side of the cylindrical portion 124A in the axial direction of the bottom portion 122A. The cylindrical portion 124A has a radially inner inner peripheral surface 124Aa that is cylindrical. The concave groove 602 is arranged at a boundary position between the bottom surface 122Aa and the inner peripheral surface 124Aa. The concave groove 602 has an annular shape centered on the central axis of the cylindrical portion 124A. The concave groove 602 has a semicircular cross section along a plane including the central axis of the cylindrical portion 124A.

The stopper member 601 is fixed to the case member 95A while being inserted into the recessed groove 602 of the case member 95A. Specifically, the stopper member 601 is a C-ring obtained by cutting out a part of an annular ring. The stopper member 601 is fixed to the case member 95A by its own radially outward elastic force.

When the stopper member 601 is fixed to the case member 95A while being inserted into the groove 602, a part of the stopper member 601 protrudes from the bottom surface 122Aa of the bottom portion 122A. The stopper member 601 has a stopper portion 605 that protrudes from the bottom surface 122Aa of the bottom portion 122A. The stopper portion 605 has a curved projecting surface 605a projecting from the bottom surface 122Aa. The contact portion 416 of the disc spring 116 faces the projecting surface 605a of the stopper portion 605 in the axial direction. The stopper portion 605 is arranged coaxially with the case member 95A. Here, the radial direction of the stopper portion 605 and the protruding surface 605a refers to the direction that coincides with the radial direction of the case member 95A.

The inner flat plate portion 414 of the disc spring 116 contacts the bottom surface 122Aa of the bottom portion 122A of the case member 95A. The minimum diameter of the projecting surface 605 a of the stopper portion 605 is smaller than the outer diameter of the outer tapered portion 403 of the disc spring 116 and larger than the outer diameter of the inner flat portion 414 . The maximum diameter of the projecting surface 605 a of the stopper portion 605 is larger than the outer diameter of the outer tapered portion 403 of the disc spring 116 . In other words, the projection surface 605a of the stopper portion 605 has a minimum diameter smaller than the outer diameter of the contact portion 416, and a maximum diameter of the projection surface 605a larger than the outer diameter of the contact portion 416. .

A protruding surface 605a of the stopper portion 605 protrudes in the axial direction from the bottom surface 122Aa of the bottom portion 122A toward the disc spring 116 side. Moreover, the protruding surface 605a of the stopper portion 605 protrudes from the inner flat plate portion 414 of the disc spring 116 to the side opposite to the bottom portion 122A in the axial direction. In other words, the projecting surface 605a of the stopper portion 605 is located on the side on which the disc spring 116 is arranged relative to the bottom surface 122Aa of the bottom portion 122A in the axial direction. Further, in other words, the projecting surface 605a of the stopper portion 605 is located axially further than the end portion of the main portion 417 on the other axial end side of the contact portion 416 on the one axial end side of the disc spring 116. is formed so as to protrude toward the contact portion 416 side. The protruding surface 605a of the stopper portion 605 is such that the contact portion 416 on the one end side in the axial direction of the disc spring 116 is positioned axially further than the main portion 417, which is a portion on the inner peripheral side of the contact portion 416, in the axial direction of the disc spring 116. is suppressed from being displaced to the other end side. The stopper portion 605 abuts against the disc spring 116 with a protruding surface 605 a facing the contact portion 416 to suppress such displacement of the disc spring 116 .

In the shock absorber 1A of the second embodiment, even if the outer tapered portion 403 of the disc spring 116 is deformed so as to increase the taper, the stopper portion 605 contacts the outer tapered portion 403 with its protruding surface 605a. The contact portion 416 at the outer peripheral end of the outer tapered portion 403 is prevented from being displaced from the main portion 417 toward the bottom surface 122Aa of the bottom portion 122A. In this way, the projecting surface 605a of the stopper portion 605 prevents the outer tapered portion 403 of the disc spring 116 from being deformed such that the outer peripheral side thereof is positioned closer to the bottom portion 122 than the inner peripheral side. As a result, in the disc spring 116, the shape of the outer tapered portion 403 can be suppressed from being reversed in the axial direction with respect to the normal shape. Therefore, it becomes possible to suppress deterioration in function.

The stopper portion 605 is arranged on the bottom surface 122Aa of the case member 95A facing the contact portion 416 of the disc spring 116, and is fixed so as to protrude from the main portion 417 of the disc spring 116 toward the contact portion 416. It is provided on the stopper member 601 . Therefore, with a simple structure, it is possible to prevent the outer tapered portion 403 of the disc spring 116 from becoming axially inverted with respect to the normal shape.

A protruding surface 605a of the stopper portion 605 is formed over the entire circumferential direction of the case member 95 so as to protrude toward the contact portion 416 from the end portion of the main portion 417 of the disc spring 116 on the side of the bottom surface 122Aa. can be That is, at least a part of the protruding surface 605a of the stopper portion 605 should be formed so as to protrude toward the contact portion 416 from the end portion of the main portion 417 of the disc spring 116 on the side of the bottom surface 122Aa.

[Third embodiment]
Next, the third embodiment will be described mainly based on FIG. 5, focusing on the differences from the first embodiment. Parts common to those of the first embodiment are denoted by the same designations and the same reference numerals.

As shown in FIG. 5, the shock absorber 1B of the third embodiment has a case member 95B that is partially different from the case member 95 instead of the case member 95. As shown in FIG. The variable lower chamber volume mechanism 185B differs from the variable lower chamber volume mechanism 185 in that the case member 95B is replaced with the case member 95B. The variable upper chamber volume mechanism 186B differs from the variable upper chamber volume mechanism 186 in that the case member 95 is replaced with a case member 95B. The accumulator 190B differs from the accumulator 190 in that it has a case member 95B instead of the case member 95. As shown in FIG.

Like the case member 95, the case member 95B is an integrally molded product having a bottomed tubular shape, and is formed, for example, by plastic working or cutting of a metal plate. The case member 95B has a bottom portion 122B and a cylindrical portion 124B. The bottom portion 122B has a bottom body portion 611 and a stopper portion 612 . The bottom main body portion 611 has a constant thickness and a perforated circular plate shape with a constant radial width over the entire circumference. The cylindrical portion 124B extends from the outer peripheral edge portion of the bottom main body portion 611 to one side of the bottom main body portion 611 in the axial direction. The stopper portion 612 is arranged on the cylindrical portion 124B side in the radial direction of the bottom body portion 611 .

The bottom body portion 611 has a planar bottom surface 611a on the cylindrical portion 124B side in the axial direction. The stopper portion 612 deforms and protrudes from the bottom surface 611 a of the bottom body portion 611 toward the tubular portion 124 B in the axial direction of the bottom body portion 611 . The stopper portion 612 is formed over the entire circumference of the bottom body portion 611 and has an annular shape. The stopper portion 612 is formed coaxially with the bottom body portion 611 and the cylindrical portion 124B. The stopper portion 612 has a curved projecting surface 612a projecting from its bottom surface 611a. The stopper portion 612 is arranged coaxially with the bottom body portion 611 and the cylindrical portion 124B. Here, the radial direction of the stopper portion 612 and the projecting surface 612a is the direction that coincides with the radial direction of the bottom body portion 611 and the cylindrical portion 124B. The cylindrical portion 124B has a radially inner inner peripheral surface 124Ba that is continuous with the outer peripheral edge of the bottom surface 611a.

As with the bottom portion 122 , the bottom portion 122</b>B has the mounting shaft portion 28 of the piston rod 25 fitted to its inner peripheral portion. A plurality of passage holes 126B similar to the plurality of passage holes 126 are formed in the bottom body portion 611 of the bottom portion 122B. The plurality of passage holes 126B are arranged inside the stopper portion 612 in the radial direction of the bottom body portion 611 . The bottom portion 122B of the case member 95B contacts the disk 87 with the bottom portion 122B positioned closer to the piston 21 than the cylindrical portion 124B. Like the case member 95, the case member 95B also abuts on the main valve 91 to restrict the deformation of the main valve 91 in the opening direction beyond a specified limit.

The inner flat plate portion 414 of the disc spring 116 contacts the bottom surface 611a of the bottom body portion 611 of the case member 95B. The contact portion 416 of the disc spring 116 faces the projecting surface 612a of the stopper portion 612 in the axial direction. The minimum diameter of the projecting surface 612 a of the stopper portion 612 is smaller than the outer diameter of the outer tapered portion 403 of the disc spring 116 and larger than the outer diameter of the inner flat portion 414 . The maximum diameter of the projecting surface 612 a of the stopper portion 612 is smaller than the outer diameter of the outer tapered portion 403 of the disc spring 116 . In other words, the minimum diameter of the projecting surface 612 a of the stopper portion 612 is smaller than the outer diameter of the contact portion 416 , and the maximum diameter of the projecting surface 612 a is smaller than the outer diameter of the contact portion 416 .

A protruding surface 612a of the stopper portion 612 protrudes from the bottom surface 611a of the bottom main body portion 611 toward the disc spring 116 in the axial direction. Moreover, the protruding surface 612a of the stopper portion 612 protrudes to the opposite side of the bottom main body portion 611 from the inner flat plate portion 414 of the disc spring 116 in the axial direction. In other words, the projecting surface 612a of the stopper portion 612 is located on the side on which the disc spring 116 is arranged relative to the bottom surface 611a of the bottom body portion 611 in the axial direction. Further, in other words, the projecting surface 612a of the stopper portion 612 is located axially further than the end portion of the main portion 417 on the other axial end side of the contact portion 416 on the one axial end side of the disc spring 116. is formed so as to protrude toward the contact portion 416 side. The protruding surface 612 a of the stopper portion 612 is such that the contact portion 416 on one end side of the disc spring 116 in the axial direction is axially positioned further than the main portion 417 , which is a portion on the inner peripheral side of the contact portion 416 . is suppressed from being displaced to the other end side. The stopper portion 612 abuts against the disc spring 116 with a protruding surface 612 a facing the contact portion 416 to suppress such displacement of the disc spring 116 .

In the shock absorber 1B of the third embodiment, even if the outer tapered portion 403 of the disc spring 116 is deformed so as to increase the taper, the stopper portion 612 contacts the outer tapered portion 403 with its protruding surface 612a. The contact portion 416 at the outer peripheral end of the outer tapered portion 403 is prevented from being displaced from the main portion 417 toward the bottom surface 611 a of the bottom main portion 611 . Thus, the protruding surface 612a of the stopper portion 612 prevents the outer tapered portion 403 of the disc spring 116 from being deformed such that the outer peripheral side is positioned closer to the bottom main body portion 611 than the inner peripheral side. As a result, in the disc spring 116, the shape of the outer tapered portion 403 can be suppressed from being reversed in the axial direction with respect to the normal shape. Therefore, it becomes possible to suppress deterioration in function.

A projecting surface 612a of the stopper portion 612 formed in the case member 95B, which faces the abutment portion 416 of the disc spring 116, extends over the entire circumference of the case member 95B. It is formed so as to deform toward the contact portion 416 side rather than the portion. Therefore, it is possible to prevent the outer tapered portion 403 of the coned disc spring 116 from becoming axially reversed with respect to the normal shape with a simple structure without increasing the number of parts.

The protruding surface 612a of the stopper portion 612 is partially deformed and protrudes toward the contact portion 416 from the end of the main portion 417 of the disc spring 116 on the side of the bottom surface 122a in the circumferential direction of the case member 95. It's okay to be. That is, at least a part of the protruding surface 612a of the stopper portion 612 should be formed so as to deform and protrude toward the contact portion 416 from the end portion of the main portion 417 of the disc spring 116 on the side of the bottom surface 611a.

[Fourth embodiment]
Next, the fourth embodiment will be described mainly based on FIG. 6, focusing on the differences from the first embodiment. Parts common to those of the first embodiment are denoted by the same designations and the same reference numerals.

As shown in FIG. 6, the shock absorber 1C of the fourth embodiment has a case member 95C that is partially different from the case member 95 instead of the case member 95. As shown in FIG. In addition, instead of the disc spring 116, a disc spring 116C, which is partially different from the disc spring 116, is provided. The variable lower chamber volume mechanism 185C differs from the variable lower chamber volume mechanism 185 in that it has a case member 95C instead of the case member 95 and a disc spring 116C instead of the disc spring 116. FIG. The variable upper chamber volume mechanism 186C differs from the variable upper chamber volume mechanism 186 in that it has a case member 95C instead of the case member 95 and a disc spring 116C instead of the disc spring 116. FIG. The accumulator 190C differs from the accumulator 190 in that it has a case member 95C instead of the case member 95 and a disc spring 116C instead of the disc spring 116. As shown in FIG. The relief mechanism 532C differs from the relief mechanism 532 in that it has a disc spring 116C instead of the disc spring 116. As shown in FIG.

Like the case member 95, the case member 95C is an integrally molded product having a bottomed tubular shape, and is formed by, for example, plastic working or cutting of a metal plate. The case member 95C has a bottom portion 122C and a cylindrical portion 124C. The bottom portion 122C has a constant thickness and a perforated circular plate shape with a constant radial width over the entire circumference. The cylindrical portion 124C extends from the outer peripheral edge portion of the bottom portion 122C to one axial side of the bottom portion 122C.

The bottom portion 122C has a planar bottom surface 122Ca on the cylindrical portion 124C side in the axial direction. As with the bottom portion 122, the bottom portion 122C has the mounting shaft portion 28 of the piston rod 25 fitted to its inner peripheral portion. A plurality of passage holes 126C similar to the plurality of passage holes 126 are formed in the bottom portion 122C. The cylindrical portion 124C has a radially inner inner peripheral surface 124Ca that is continuous with the outer peripheral edge portion of the bottom surface 122Ca. The case member 95C abuts on the disc 87 with the bottom portion 122C positioned closer to the piston 21 than the cylindrical portion 124C. Like the case member 95, the case member 95C abuts on the main valve 91 and restricts the deformation of the main valve 91 in the opening direction beyond a specified limit.

The disc spring 116</b>C differs from the disc spring 116 in that it further has a stopper portion 621 . The disc spring 116C, including the stopper portion 621, is formed from a sheet of plate material by punching by press molding and bending by press molding. The stopper portion 621 has a conical cylindrical shape extending radially outward from the outer peripheral edge portion of the outer tapered portion 403 toward the inner flat portion 414 side in the axial direction. The disc spring 116C has a stopper portion 621 at its outer diameter side end. The stopper portion 621 has a constant radial width over the entire circumference. The stopper portion 621 has a constant length in the axial direction over the entire circumference. Both the radial width and the axial length of the stopper portion 621 are shorter than those of the outer tapered portion 403 . The outer peripheral end of the stopper portion 621 is the outer peripheral end of the disc spring 116C. The stopper portion 621 is radially outside the contact portion 416 at the outer peripheral end of the outer tapered portion 403 . The stopper portion 621 is closer to the inner flat portion 414 in the axial direction than the contact portion 416 of the outer tapered portion 403 .

The disc spring 116</b>C has an outer diameter of the stopper portion 621 , that is, the outer diameter of the disc spring 116</b>C, which is slightly smaller than the inner diameter of the cylindrical portion 124 of the case member 95 . The disc spring 116</b>C contacts the bottom surface 122 a of the bottom portion 122 of the case member 95 at the inner flat plate portion 414 having the inner annular portion 401 , the intermediate annular portion 402 and the support portion 404 . The stopper portion 621 of the disc spring 116C faces the bottom surface 122Ca of the bottom portion 122C of the case member 95C in the axial direction.

The stopper portion 621 is provided at the outer peripheral end of the disc spring 116C. The stopper portion 621 is formed to deform and protrude from the outer peripheral edge portion of the outer tapered portion 403 toward the side opposite to the contact portion 416 of the main portion 417 in the axial direction of the disc spring 116C. In the stopper portion 621, the contact portion 416 on the one end side of the disc spring 116C in the axial direction is closer to the other end side of the disc spring 116C in the axial direction than the main portion 417, which is a portion on the inner peripheral side of the contact portion 416. suppress the displacement to The stopper portion 621 of the disc spring 116C abuts against the bottom surface 122Ca of the bottom portion 122C of the case member 95 to suppress such displacement of the disc spring 116C.

In the shock absorber 1C of the fourth embodiment, even if the outer tapered portion 403 of the disc spring 116C is deformed to increase the taper, the stopper portion 621 contacts the bottom surface 122Ca of the case member 95C and the outer tapered portion The contact portion 416 at the outer peripheral end of the portion 403 is prevented from being displaced from the main portion 417 toward the bottom surface 122Ca of the bottom portion 122C. In this manner, the stopper portion 621 prevents the outer tapered portion 403 of the disc spring 116C from deforming such that the outer peripheral side thereof is positioned closer to the bottom portion 122C than the inner peripheral side. As a result, in the disc spring 116C, it is possible to prevent the outer tapered portion 403 from becoming an inverted shape in the axial direction with respect to the normal shape. Therefore, it becomes possible to suppress deterioration in function.

Also, the stopper portion 621 is provided at the outer peripheral end of the disc spring 116C. The stopper portion 621 is formed to deform and protrude from the outer peripheral edge portion of the outer tapered portion 403 toward the side opposite to the contact portion 416 of the main portion 417 in the axial direction of the disc spring 116C. Therefore, it is possible to prevent the outer tapered portion 403 of the coned disc spring 116C from becoming axially reversed with a simple structure without increasing the number of parts.

In addition, the stopper portion 621 partially extends in the circumferential direction of the disc spring 116C from the outer peripheral edge portion of the outer tapered portion 403 toward the opposite side of the contact portion 416 of the main portion 417 in the axial direction of the disc spring 116C. It may be formed so as to deform and protrude. That is, at least a part of the outer peripheral end of the disc spring 116C should be formed so as to deform and protrude from the outer peripheral edge of the outer tapered portion 403 toward the bottom surface 122Ca of the main portion 417 of the disc spring 116 .

In the first to fourth embodiments, the first passage 92 through which the oil flows out from the upper chamber 22 and the first passage 72 through which the oil flows out from the lower chamber 23 are provided. A first passage through which oil flows out from both of the lower chambers 23 may be provided. It is only necessary to have a first passage through which oil flows out from at least one of the upper chamber 22 and the lower chamber 23 as the piston 21 moves.

Reference Signs List 1, 1A to 1C... Shock absorber, 4... Cylinder, 21... Piston, 22... Upper chamber (chamber), 23... Lower chamber (chamber), 25... Piston rod, 41, 42... First damping force generating mechanism, 72 , 92... First passage 95, 95A to 95C... Case member 100... Disk valve 116, 116C... Disc spring 123... Intermediate taper portion (stopper portion) 123a... Inner surface 172, 182... Second passage, Reference numerals 173, 183: second damping force generating mechanism, 190, 190A to 190C: accumulator, 416: contact portion, 417: main portion (part on the inner peripheral side of the contact portion), 511, 512: third passage, 601... Stopper member, 605, 612, 621... Stopper portion, 605a, 612a... Protruding surface.

Claims (4)

a cylinder in which the working fluid is sealed;
a piston slidably provided in the cylinder and partitioning the inside of the cylinder into two chambers;
a piston rod connected to the piston and extending outside the cylinder;
a first passage through which the working fluid flows from at least one of the two chambers by movement of the piston;
a first damping force generating mechanism provided in the first passage and generating a damping force;
a second passage parallel to the first passage;
a second damping force generating mechanism that is provided in the second passage and opens to generate a damping force when the piston speed is lower than that of the first damping force generating mechanism;
a third passage provided in parallel with the second damping force generating mechanism;
A disc valve provided in the third passage, a disc spring with which a contact portion on one end side abuts against the disc valve, and a case member that abuts on the other end side of the disc spring and covers the disc valve and the disc spring. and an accumulator having
a stopper portion that prevents the contact portion from being displaced toward the other end from a portion of the disc spring that is located on the inner peripheral side of the corresponding contact portion;
Buffer with. A shock absorber according to claim 1,
At least a portion of the surface of the case member facing the contact portion of the stopper portion extends toward the contact portion from the other end of the portion of the disc spring located on the inner peripheral side of the contact portion. A buffer that is shaped to deform or protrude. A shock absorber according to claim 1,
The stopper portion is disposed on a surface of the case member facing the contact portion, and at least a portion of the stopper portion protrudes toward the contact portion from a portion of the disc spring located on the inner peripheral side of the contact portion. A shock absorber provided on a stopper member that is fixed in place. A shock absorber according to claim 1,
The stopper portion is a shock absorber formed so that at least a part of the outer peripheral end of the disc spring deforms or protrudes toward the other end of the disc spring.

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