JP2020139515A - Hydraulic shock absorber - Google Patents

Abstract

To provide a hydraulic shock absorber which can prevent an attenuation force from being excessively hard in a characteristic.SOLUTION: A hydraulic shock absorber has: a disc valve 141 arranged at one chamber 34 side of a partitioning member 33, seated on a first seat 91 formed inside a passage 54 in a radial direction, also seated on a second seat 92 formed outside the passage 54 in the radial direction, and opening and closing the passage 54; and a washer 142 arranged at a side opposite to the partitioning member 33 of the disc valve 141, and regulating a valve-opening direction of the disc valve 141. An external peripheral part of the disc valve 141 is formed into an irregular shape while being formed with a plurality of large-diameter parts 153 and a plurality of small-diameter parts 154 over an entire periphery, and at least one small-diameter part out of the small-diameter parts 154 is seated on the second seat 92.SELECTED DRAWING: Figure 2

Description

The present invention relates to a fluid pressure shock absorber.

Generally, in a vehicle such as a four-wheeled vehicle, a hydraulic shock absorber as a cylinder device is provided between each wheel (axle side) and the vehicle body to buffer the vibration of the vehicle (for example, Patent Documents 1 to 3). reference).

JP-A-2017-1982293 Japanese Unexamined Patent Publication No. 2015-129545 Japanese Unexamined Patent Publication No. 2015-86966

There is a demand to prevent the damping force from becoming excessively hard.

Therefore, an object of the present invention is to provide a fluid pressure shock absorber capable of suppressing the damping force from becoming an excessively hard characteristic.

In order to achieve the above object, the present invention defines two chambers in a cylinder and has a partition member having a passage capable of communicating between the two chambers and at least one of the two chambers of the partition member. A disc valve that is provided on the chamber side of the vehicle and is seated on a first seat formed radially inside the aisle and a second seat formed radially outside the aisle to open and close the aisle. The disc valve has a washer provided on the side opposite to the partition member and regulates the valve opening direction of the disc valve, and the outer peripheral portion of the disc valve has a plurality of large diameter portions over the entire circumference. A plurality of small diameter portions are formed to form an uneven shape, and at least one small diameter portion of the small diameter portions is configured to be seated on the second seat.

According to the present invention, it is possible to prevent the damping force from becoming an excessively hard characteristic.

It is sectional drawing which shows the fluid pressure shock absorber of 1st Embodiment which concerns on this invention. It is sectional drawing at the time of valve closing which shows the main part of the fluid pressure shock absorber of 1st Embodiment which concerns on this invention. It is a top view which shows the disk valve of the fluid pressure shock absorber of 1st Embodiment which concerns on this invention. It is a figure which shows the washer of the fluid pressure shock absorber of the 1st Embodiment which concerns on this invention, (a) is a plan view, (b) is a bb sectional view of (a). It is a top view which shows the urging member of the fluid pressure shock absorber of 1st Embodiment which concerns on this invention. It is a characteristic diagram of the damping force with respect to the piston speed of the fluid pressure shock absorber of 1st Embodiment which concerns on this invention. It is sectional drawing at the time of valve opening which shows the main part of the fluid pressure shock absorber of 1st Embodiment which concerns on this invention. It is sectional drawing at the time of valve closing which shows the main part of the modification of the fluid pressure shock absorber of 1st Embodiment which concerns on this invention. It is a top view which shows the disk valve of the modification of the fluid pressure shock absorber of 1st Embodiment which concerns on this invention. It is sectional drawing at the time of valve closing which shows the main part of the fluid pressure shock absorber of the 2nd Embodiment which concerns on this invention. It is sectional drawing at the time of valve closing which shows the main part of the fluid pressure shock absorber of the 3rd Embodiment which concerns on this invention. It is sectional drawing at the time of valve opening which shows the main part of the fluid pressure shock absorber of the 3rd Embodiment which concerns on this invention. It is sectional drawing at the time of valve opening which shows the main part of the fluid pressure shock absorber of the 3rd Embodiment which concerns on this invention. It is sectional drawing at the time of valve closing which shows the main part of the fluid pressure shock absorber of the 4th Embodiment which concerns on this invention. It is sectional drawing at the time of valve closing which shows the main part of the fluid pressure shock absorber of the 5th Embodiment which concerns on this invention. It is a top view which shows the disk valve of the fluid pressure shock absorber of the 5th Embodiment which concerns on this invention.

"First embodiment"
The fluid pressure shock absorber of the first embodiment according to the present invention will be described below with reference to FIGS. 1 to 9.

The fluid pressure shock absorber 10 of the first embodiment shown in FIG. 1 is a shock absorber used for a suspension device of a vehicle such as an automobile or a railroad vehicle. The fluid pressure shock absorber 10 of the first embodiment has a cylinder 11 in which a working fluid is sealed. The cylinder 11 is a bottomed cylindrical outer cylinder 14 having a diameter larger than that of the inner cylinder 12 and being provided on the outer peripheral side of the inner cylinder 12 and forming a reservoir chamber 13 between the cylindrical inner cylinder 12 and the inner cylinder 12. And have. That is, the fluid pressure shock absorber 10 has a double-cylinder type cylinder 11 in which the inner cylinder 12 is provided in the outer cylinder 14.

The outer cylinder 14 is an integrally molded product made of one metal member, and has a cylindrical side wall portion 17 and a bottom portion 18 that closes one end side of the side wall portion 17 in the axial direction. The side opposite to the bottom 18 of the is an opening 19.

The bottom portion 18 has a tapered tubular portion 21 extending from an edge portion of the side wall portion 17 opposite to the axial opening 19 so as to decrease in diameter toward the side wall portion 17, and a side wall of the tapered tubular portion 21. It has a flat plate-shaped disk portion 22 extending inward in the radial direction from an end edge portion on the opposite side of the portion 17. The tapered tubular portion 21 has a tapered shape centered on the central axis of the side wall portion 17, and the disk portion 22 extends orthogonally to the central axis of the side wall portion 17.

The inner cylinder 12 is an integrally molded product made of one metal member, and has a cylindrical shape. The inner cylinder 12 has an opening 24 on one end side in the axial direction and an opening 25 on the other end side. The inner cylinder 12 is engaged with the bottom portion 18 of the outer cylinder 14 via an annular base member 27 attached to the opening 24 side at one end in the axial direction. Further, the inner cylinder 12 is engaged with the bottom portion 18 of the side wall portion 17 of the outer cylinder 14 via an annular rod guide 28 attached to the opening 25 side of the other end in the axial direction. .. The opening 25 of the inner cylinder 12 is on the bottom 18 side of the opening 19 of the outer cylinder 14.

The base member 27 is placed on the bottom 18 of the outer cylinder 14 in a state of being fitted and fixed to the inner peripheral portion of the inner cylinder 12 on the opening 24 side, and in this state, the tapered tubular portion 21 of the bottom 18 is placed. Is positioned in the radial direction. As a result, the base member 27 is arranged coaxially with the outer cylinder 14, and as a result, one end portion of the inner cylinder 12 in the axial direction is arranged coaxially with the outer cylinder 14.

The rod guide 28 is fitted to the inner peripheral portion of the inner cylinder 12 on the opening 25 side and the inner peripheral portion of the side wall portion 17 of the outer cylinder 14 on the opening 19 side, thereby fitting the other end portion of the inner cylinder 12 in the axial direction. Is arranged coaxially with the outer cylinder 14.

An annular seal member 30 is arranged on the side opposite to the bottom 18 with respect to the rod guide 28, and this seal member 30 is also fitted to the inner peripheral portion of the side wall portion 17 on the opening 19 side. A crimping portion 31 that is plastically deformed inward in the radial direction by curling is formed on the opening 19 side opposite to the bottom portion 18 of the side wall portion 17, and the sealing member 30 is formed with the crimping portion 31. It is sandwiched between the rod guide 28 and the rod guide 28. The seal member 30 seals the opening 19 side of the outer cylinder 14.

A piston 33 (partition member) is slidably fitted in the inner cylinder 12. The piston 33 defines the inside of the inner cylinder 12 of the cylinder 11 into a first chamber 34 (one chamber) and a second chamber 35. The first chamber 34 is provided between the piston 33 in the inner cylinder 12 and the rod guide 28, and the second chamber 35 is provided between the piston 33 in the inner cylinder 12 and the base member 27. The second chamber 35 in the inner cylinder 12 is defined as the reservoir chamber 13 by the base member 27 provided on one end side of the inner cylinder 12. The reservoir chamber 13 extends between the base member 27 and the bottom 18. The first chamber 34 and the second chamber 35 are filled with an oil liquid which is a working fluid, and the reservoir chamber 13 is filled with a gas and an oil liquid which are working fluids. Therefore, the fluid pressure shock absorber 10 is a hydraulic shock absorber.

A rod 38 is connected to the piston 33 by a nut 39. The rod 38 has a mounting shaft portion 41 to which the piston 33 and the nut 39 are mounted, and a spindle portion 42 having a diameter larger than that of the mounting shaft portion 41. At the end of the main shaft portion 42 on the mounting shaft portion 41 side, a shaft step portion 43 extending in the direction orthogonal to the axis is formed. The main shaft portion 42 of the rod 38 is slidably fitted to the rod guide 28 and the seal member 30 and extends to the outside of the cylinder 11. As a result, one end side of the rod 38 is arranged in the cylinder 11 and is connected to the piston 33, and the other end side extends to the outside from the opening 19 of the outer cylinder 14.

The rod 38 is guided by the rod guide 28 and moves in the axial direction integrally with the piston 33 with respect to the cylinder 11. In other words, the rod guide 28 guides the axial movement of the rod 38. The seal member 30 closes between the outer cylinder 14 and the rod 38 to prevent the oil liquid in the inner cylinder 12 and the working gas and the oil liquid in the reservoir chamber 13 from leaking to the outside.

The piston 33 has a large diameter portion 45 that defines the inside of the inner cylinder 12 of the cylinder 11 into a first chamber 34 and a second chamber 35, and an inner cylinder whose outer diameter is smaller than the outer diameter of the large diameter portion 45. It has a middle diameter portion 46 having a diameter smaller than the inner diameter of 12 and a small diameter portion 47 having an outer diameter smaller than the outer diameter of the middle diameter portion 46 between them. In the piston 33, the large diameter portion 45 is arranged on the shaft step portion 43 side in the axial direction of the piston 33, and the medium diameter portion 46 is arranged on the side opposite to the shaft step portion 43 in the axial direction of the piston 33. .. The medium diameter portion 46 and the small diameter portion 47 are arranged in the second chamber 35.

A plurality of passage holes 51 penetrating in the axial direction are formed in the piston 33, and a plurality of passage holes 52 penetrating in the axial direction are formed inside the piston 33 in the radial direction of the passage holes 51. There is. The passage hole 51 is open to the end surface of the large diameter portion 45 on the small diameter portion 47 side. The piston 33 is formed with an annular passage recess 53 connecting a plurality of passage holes 51 on the first chamber 34 side. The plurality of passage holes 51 and the passage recess 53 form a passage 54 capable of communicating between the first chamber 34 and the second chamber 35.

The piston 33 is formed with an annular passage recess 56 connecting a plurality of passage holes 52 on the first chamber 34 side, and an annular passage connecting the plurality of passage holes 52 on the second chamber 35 side as well. A recess 57 is formed. The passage recess 56 is formed inside the passage recess 53 in the radial direction of the piston 33. The plurality of passage holes 52 and the passage recesses 56 and 57 form a passage 58 capable of communicating between the first chamber 34 and the second chamber 35.

The piston 33 is provided with a valve mechanism 61 capable of opening and closing the passage 54 on the side of the first chamber 34 of the first chamber 34 and the second chamber 35. Further, the piston 33 is provided with a valve mechanism 62 capable of opening and closing the passage 58 on the second chamber 35 side of the first chamber 34 and the second chamber 35.

In the valve mechanism 61, the rod 38 moves to the contraction side that increases the amount of entry into the inner cylinder 12 and the outer cylinder 14, the piston 33 moves in the direction of narrowing the second chamber 35, and the pressure in the second chamber 35 becomes the first. When the pressure becomes higher than the pressure of the chamber 34 by a predetermined value or more, the passage 54 is opened and the oil liquid of the second chamber 35 flows to the first chamber 34 through the passage 54, and a damping force is generated at that time. Therefore, the valve mechanism 61 is a damping force generating mechanism on the contraction side.

In the valve mechanism 62, the rod 38 moves to the extension side that increases the amount of protrusion from the inner cylinder 12 and the outer cylinder 14, the piston 33 moves in the direction of narrowing the first chamber 34, and the pressure in the first chamber 34 becomes the second chamber. When the pressure becomes higher than the pressure of 35 by a predetermined value or more, the passage 58 is opened and the oil liquid in the first chamber 34 flows to the second chamber 35 through the passage 58, and a damping force is generated at that time. Therefore, the valve mechanism 62 is a damping force generating mechanism on the extension side.

A plurality of passage holes 71 penetrating in the axial direction are formed in the base member 27, and a plurality of passage holes 72 penetrating in the axial direction are formed outside the passage holes 71 in the radial direction of the piston 33. ing. The base member 27 is formed with an annular passage recess 73 connecting a plurality of passage holes 71 on the reservoir chamber 13 side, and an annular passage connecting the plurality of passage holes 71 on the second chamber 35 side as well. A recess 74 is formed. The plurality of passage holes 71 and the passage recesses 73 and 74 form a passage 75 capable of communicating between the second chamber 35 and the reservoir chamber 13.

The base member 27 is formed with an annular passage recess 77 connecting a plurality of passage holes 72 on the second chamber 35 side. A plurality of passage holes 72 and passage recesses 77 form a passage 78 capable of communicating between the second chamber 35 and the reservoir chamber 13.

The base member 27 is provided with a valve mechanism 81 capable of opening and closing the passage 75 on the reservoir chamber 13 side of the second chamber 35 and the reservoir chamber 13. Further, the base member 27 is provided with a valve mechanism 82 capable of opening and closing the passage 78 on the second chamber 35 side of the second chamber 35 and the reservoir chamber 13. A mounting member 85 is attached to the base member 27 at the center in the radial direction, and the mounting member 85 is formed with locking portions 86 and locking portions 87 at both ends in the axial direction.

In the valve mechanism 81, the rod 38 moves to the contraction side that increases the amount of entry into the inner cylinder 12 and the outer cylinder 14, the piston 33 moves in the direction of narrowing the second chamber 35, and the pressure in the second chamber 35 becomes the reservoir chamber. When the pressure becomes higher than the pressure of 13, the passage 75 is opened and the oil liquid in the second chamber 35 flows to the reservoir chamber 13 through the passage 75, and a damping force is generated at that time. Therefore, the valve mechanism 81 is a damping force generating mechanism on the contraction side.

In the valve mechanism 82, the rod 38 moves to the extension side that increases the amount of protrusion from the inner cylinder 12 and the outer cylinder 14, the piston 33 moves in the direction of expanding the second chamber 35, and the pressure of the second chamber 35 becomes the reservoir chamber 13. When the pressure becomes lower than the pressure of, the passage 78 is opened and the oil liquid in the reservoir chamber 13 flows to the second chamber 35 through the passage 78, and at that time, the oil liquid flows without substantially generating a damping force. .. Therefore, the valve mechanism 82 is a suction valve on the extension side.

In the fluid pressure shock absorber 10, for example, the rod 38 is connected to the vehicle body side and the outer cylinder 14 is connected to the wheel side of the vehicle to generate a damping force with respect to the movement of the wheels with respect to the vehicle body.

The piston 33 has an inner sheet 90, an intermediate sheet 91 (first sheet), and an outer sheet 92 (second sheet) on the first chamber 34 side of the first chamber 34 and the second chamber 35. There is. The inner sheet 90, the intermediate sheet 91, and the outer sheet 92 are all annular, and protrude toward the first chamber 34 in the axial direction from the main body portion 95 in the axial direction of the piston 33.

The inner sheet 90 is formed inside the piston 33 in the radial direction with respect to the extension-side passage 58. The outer peripheral surface of the inner sheet 90 forms a passage recess 56 on the side of the first chamber 34 of the passage 58.

The intermediate sheet 91 is formed outside the extension side passage 58 in the radial direction of the piston 33 and inside the contraction side passage 54 in the radial direction of the piston 33. The inner peripheral surface of the intermediate sheet 91 forms a passage recess 56 on the first chamber 34 side of the passage 58, and the outer peripheral surface of the intermediate sheet 91 forms a passage recess 53 on the first chamber 34 side of the passage 54. ing. The passage recess 56 is formed by the outer peripheral surface of the inner sheet 90, the inner peripheral surface of the intermediate sheet 91, and the end surface of the main body portion 95 on the first chamber 34 side in the axial direction.

The outer sheet 92 is formed on the outer side in the radial direction of the piston 33 with respect to the passage 54 on the contraction side. The inner peripheral surface of the outer sheet 92 forms a passage recess 53 on the side of the first chamber 34 of the passage 54. The passage recess 53 is formed by an outer peripheral surface of the intermediate sheet 91, an inner peripheral surface of the outer sheet 92, and an end surface of the main body 95 on the first chamber 34 side.

The valve mechanism 61 is composed of an inner seat 90, an intermediate seat 91 and an outer seat 92 of the piston 33, and a valve portion 98 provided between these and the shaft step portion 43 of the rod 38.

The piston 33 has an inner sheet 100 and an outer sheet 101 on the second chamber 35 side of the first chamber 34 and the second chamber 35. Both the inner sheet 100 and the outer sheet 101 have an annular shape, and project from the main body portion 95 in the axial direction of the piston 33 to the side opposite to the first chamber 34 in the axial direction.

The inner sheet 100 is formed inside the piston 33 in the radial direction with respect to the extension side passage 58. The outer peripheral surface of the inner sheet 100 forms a passage recess 57 on the second chamber 35 side of the passage 58.

The outer sheet 101 is formed outside the extension side passage 58 in the radial direction of the piston 33. The inner peripheral surface of the outer sheet 101 forms a passage recess 57 on the second chamber 35 side of the passage 58. The passage recess 57 is formed by an outer peripheral surface of the inner sheet 100, an inner peripheral surface of the outer sheet 101, and an end surface of the main body portion 95 opposite to the first chamber 34 in the axial direction.

The valve mechanism 62 is composed of an inner seat 100 and an outer seat 101 of the piston 33, and a valve portion 105 provided between these and the nut 39.

The base member 27 has an inner sheet 110, an intermediate sheet 111, and an outer sheet 112 on the second chamber 35 side of the second chamber 35 and the reservoir chamber 13. The inner sheet 110, the intermediate sheet 111, and the outer sheet 112 are all annular, and protrude toward the second chamber 35 in the axial direction from the intermediate main body portion 115 in the axial direction of the base member 27.

The inner sheet 110 is formed inside the base member 27 in the radial direction with respect to the passage 75 on the contraction side. The outer peripheral surface of the inner sheet 110 forms a passage recess 74 on the second chamber 35 side of the passage 75.

The intermediate sheet 111 is formed on the outer side of the base member 27 in the radial direction of the contraction side passage 75 and on the inner side of the base member 27 in the radial direction of the extension side passage 78. The inner peripheral surface of the intermediate sheet 111 forms a passage recess 74 on the second chamber 35 side of the passage 75, and the outer peripheral surface of the intermediate sheet 111 forms a passage recess 77 on the second chamber 35 side of the passage 78. ing. The passage recess 74 is formed by an outer peripheral surface of the inner sheet 110, an inner peripheral surface of the intermediate sheet 111, and an end surface of the main body portion 115 on the second chamber 35 side in the axial direction.

The outer sheet 112 is formed on the outer side of the base member 27 in the radial direction with respect to the extension-side passage 78. The inner peripheral surface of the outer sheet 112 forms a passage recess 77 on the side of the second chamber 35 of the passage 78. The passage recess 77 is formed by an outer peripheral surface of the intermediate sheet 111, an inner peripheral surface of the outer sheet 112, and an end surface of the main body portion 115 on the second chamber 35 side in the axial direction.

The valve mechanism 82 is composed of an inner seat 110, an intermediate seat 111, and an outer seat 112 of the base member 27, and a valve portion 118 provided between these and the locking portion 86 of the mounting member 85.

The base member 27 has an inner sheet 120 and an outer sheet 121 on the reservoir chamber 13 side of the second chamber 35 and the reservoir chamber 13. Both the inner sheet 120 and the outer sheet 121 are annular and project toward the reservoir chamber 13 in the axial direction from the intermediate main body 115 in the axial direction of the base member 27.

The inner sheet 120 is formed inside the base member 27 in the radial direction with respect to the contracted passage 75. The outer peripheral surface of the inner sheet 120 forms a passage recess 73 on the reservoir chamber 13 side of the passage 75.

The outer sheet 121 is formed on the outer side of the base member 27 in the radial direction of the contraction side passage 75 and on the inner side of the base member 27 in the radial direction of the extension side passage 78. The inner peripheral surface of the outer sheet 121 forms a passage recess 73 on the base member 27 side of the passage 75. The passage recess 73 is formed by an outer peripheral surface of the inner sheet 120, an inner peripheral surface of the outer sheet 121, and an end surface of the main body 115 on the reservoir chamber 13 side in the axial direction.

The valve mechanism 81 is composed of an inner seat 120 and an outer seat 121 of the base member 27, and a valve portion 125 provided between these and the locking portion 87 of the mounting member 85.

As shown in FIG. 2, the valve portion 98 constituting the valve mechanism 61 is a single disc valve provided on the first chamber 34 side, which is one of the first chamber 34 and the second chamber 35 of the piston 33. 141, one washer 142 provided on the side opposite to the piston 33 of the disc valve 141, one urging member 143 provided between the disc valve 141 and the washer 142, and the urging member 143. It has one small-diameter disk 144 provided between the washer 142 and the washer 142. The disc valve 141, the washer 142, the urging member 143, and the small diameter disc 144 are all positioned in the radial direction with respect to the rod 38 and the piston 33 by being fitted to the mounting shaft portion 41.

The washer 142 is arranged on the shaft step portion 43 side of the rod 38 most of the valve portions 98, and is in contact with the shaft step portion 43. The small-diameter disc 144 is arranged on the side opposite to the shaft step portion 43 of the washer 142, and is in contact with the washer 142. The urging member 143 is arranged on the side opposite to the washer 142 of the small diameter disc 144, and is in contact with the small diameter disc 144. The disc valve 141 is arranged on the side of the urging member 143 opposite to the small diameter disc 144, and is in contact with the urging member 143 and the piston 33. The washer 142, the small diameter disc 144, the urging member 143, and the disc valve 141 are axially clamped by the shaft step portion 43 and the inner seat 90 of the piston 33.

The disc valve 141 has a flat plate shape as a whole, and has an annular shape as shown in FIG. A plurality of disc valves 141 are provided at equal intervals on a perforated disk-shaped main body 152 having a fitting hole 151 formed in the center of the radial direction to fit the mounting shaft 41 of the rod 38 and on the outer peripheral portion of the main body 152. Specifically, it has a large diameter portion 153 formed at 12 locations and protruding outward in the radial direction from the outer peripheral portion of the main body portion 152.

The large diameter portion 153 is formed intermittently in the circumferential direction of the disc valve 141. Therefore, the outer peripheral portion of the disc valve 141 is located between the large diameter portion 153 and the large diameter portion 153 adjacent to each other in the circumferential direction. A small diameter portion 154 (one small diameter portion) having an outer diameter of the disc valve 141 in the radial direction smaller than the outer diameter of the large diameter portion 153 is formed. The small diameter portion 154 is a portion constituting the main body portion 152, and is formed in the same number as the large diameter portion 153, specifically, 12 locations. The number of small diameter portions 154 is not limited to 12, and may be more or less than 12 locations.

The large diameter portion 153 is provided on the outer peripheral portion of the disc valve 141 and has a tongue piece shape that protrudes outward in the radial direction from the main body portion 152. The small diameter portion 154 is provided on the outer peripheral portion of the disc valve 141 and forms the bottom portion of the recess 158 that is recessed inward in the radial direction of the disc valve 141 from the protruding tip of the large diameter portion 153. Therefore, the outer peripheral portion of the disc valve 141 is formed so that a plurality of large diameter portions 153 and a plurality of small diameter portions 154 are alternately arranged with one large diameter portion 153 and one small diameter portion 154 over the entire circumference. It has an uneven shape.

As shown in FIG. 2, the disc valve 141 has a seat surface which is an end surface of the inner seat 90 of the piston 33 on the first chamber 34 side in the axial direction by clamping the inner peripheral side of the main body portion 152 in the axial direction. Always in contact with 90a. In the disc valve 141, the main body 152 has a seat surface 91a, which is the end surface of the intermediate seat 91 on the first chamber 34 side in the axial direction, and a seat surface 92a, which is the end surface of the outer seat 92 on the first chamber 34 side in the axial direction. Sit down and close the passage 54 between them.

The inner diameter of the fitting hole 151 is smaller than the outer diameter of the seat surface 90a of the inner sheet 90. The outer diameter of the main body portion 152, that is, the outer diameter of the disc valve 141 of the small diameter portion 154 in the radial direction is larger than the inner diameter of the seat surface 92a of the outer seat 92 of the piston 33 and larger than the outer diameter of the seat surface 92a. It has a small diameter. Therefore, the main body portion 152 including the small diameter portion 154 is seated on the seat surface 92a of the outer seat 92. When the main body 152 seats on the seat surface 92a of the outer seat 92, the disc valve 141 closes the flow path between the first chamber 34 and the aisle 54, that is, the second chamber 35. The outer diameter of the main body 152 is set to be closer to the inner diameter than the outer diameter of the seat surface 92a.

As shown in FIG. 3, the main body 152 has a passage hole 161 that axially penetrates the main body 152 at a position between the seat surface 90a of the inner sheet 90 and the seat surface 91a of the intermediate sheet 91. , Multiple, specifically four places are formed. The passage hole 161 has an arc shape centered on the central axis of the disc valve 141, and the corresponding large-diameter portion 153 is in phase with the central position of the disc valve 141 in the circumferential direction. As shown in FIG. 2, the passage in the passage hole 161 always communicates with the passage 58.

The outer sheet 92 is formed so that a passage groove 165 recessed on the main body portion 95 side in the axial direction from the seat surface 92a penetrates in the radial direction. The aisle groove 165 is a fixed orifice that constantly communicates the first chamber 34 with the aisle 54, that is, the second chamber 35, even when the disc valve 141 is in contact with the seat surface 92a of the outer seat 92 in the main body portion 152. It constitutes 166.

The outer diameter of the disc valve 141 of the large diameter portion 153 in the radial direction is larger than the outer diameter of the seat surface 92a of the outer seat 92 of the piston 33.

As described above, in the disc valve 141, the outer diameter of the small diameter portion 154 is larger than the inner diameter of the seat surface 92a of the outer seat 92 of the piston 33 and smaller than the outer diameter of the seat surface 92a. Therefore, the intermediate seat 91 formed radially inside the aisle 54 and the outer seat 92 formed radially outside the aisle 54 are seated to open and close the passage 54. With the aisle 54 seated on the outer seat 92 and the intermediate seat 91, all the small diameter portions 154 of the disc valve 141 are seated on the outer seat 92. The small diameter portion 154 comes into contact with the vicinity of the inner end position in the radial direction of the seat surface 92a of the outer sheet 92.

The washer 142 is a plate-shaped member which is thicker than the disc valve 141 and has higher rigidity than the disc valve 141. The washer 142 has an annular shape, and as shown in FIG. 4A, a perforated disk-shaped main body having a fitting hole 171 formed in the center in the radial direction to fit into the mounting shaft portion 41 of the rod 38. It has a 172 and a large-diameter portion 173 formed at a plurality of equal intervals, specifically eight locations, on the outer peripheral portion of the main body portion 172 and projecting outward in the radial direction from the main body portion 172. As shown in FIG. 4B, the plurality of large diameter portions 173 are formed so as to be equidistant on the same side in the axial direction with respect to the main portion 172.

As shown in FIG. 4A, the large-diameter portion 173 is formed intermittently in the circumferential direction of the washer 142. Therefore, the outer peripheral portion of the washer 142 has a large-diameter portion 173 adjacent to each other in the circumferential direction. A small diameter portion 174 composed of a main body portion 172 is formed between the large diameter portion 173 and the large diameter portion 173. The small diameter portion 174 is formed in the same number as the large diameter portion 173, specifically, at eight locations.

The large diameter portion 173 is provided on the outer peripheral portion of the disc valve 141 and has a tongue piece shape protruding outward in the radial direction from the main body portion 172. The small diameter portion 174 is provided on the outer peripheral portion of the washer 142 and forms the bottom portion of the recess 178 which is recessed inward in the radial direction of the washer 142 from the protruding tip of the large diameter portion 173. Therefore, the outer peripheral portion of the washer 142 is formed so that a plurality of large diameter portions 173 and a plurality of small diameter portions 174 are alternately arranged with one large diameter portion 173 and one small diameter portion 174 over the entire circumference. It has an uneven shape.

As shown in FIG. 2, the washer 142 always comes into contact with the shaft step portion 43 of the rod 38 by clamping the inner peripheral side of the main body portion 172 in the axial direction. In the washer 142, a plurality of large diameter portions 173 are offset toward the piston 33 in the axial direction with respect to the main body portion 172. The outer diameter of the main body portion 172, that is, the outer diameter of the washer 142 of the small diameter portion 174 in the radial direction is smaller than the inner diameter of the seat surface 92a of the outer sheet 92 of the piston 33, and is smaller than the inner diameter of the seat surface 92a of the intermediate sheet 91. The diameter is larger than the outer diameter of. The outer diameter of the main body portion 172 is smaller than the outer diameter of the main body portion 152 of the disc valve 141.

The main body portion 172 has a circular passage hole 181 that axially penetrates the main body portion 172 at a position between the seat surface 90a of the inner sheet 90 and the seat surface 91a of the intermediate sheet 91, as shown in FIG. As described above, a plurality of, specifically four places are formed. The passage hole 181 is a circular hole, and the corresponding recess 178 is aligned with the phase of the center position of the washer 142 in the circumferential direction. As shown in FIG. 2, the passage in the passage hole 181 always communicates with the first chamber 34.

The outer diameter of the washer 142 of the large diameter portion 173 in the radial direction is equivalent to the outer diameter of the disc valve 141 of the large diameter portion 153 in the radial direction. The outer diameter of the washer 142 of the small diameter portion 174 in the radial direction is smaller than the outer diameter of the disc valve 141 of the small diameter portion 154 in the radial direction.

The large diameter portion 173 of the washer 142 is axially separated from the disc valve 141 seated on the outer seat 92 of the piston 33, and when the disc valve 141 is separated from the outer seat 92 and opened. In addition, the valve opening direction is regulated.

The urging member 143 has a fitting hole 191 formed in the mounting shaft portion 41 of the rod 38, and as shown in FIG. 5, a flat perforated hole 191 having a fitting hole 191 formed in the center in the radial direction. A disc-shaped base portion 192 and a leg portion formed at equal intervals on the outer peripheral portion of the base portion 192, specifically at five locations, and projecting outward in the radial direction of the base portion 192 from the base portion 192. It has 193 and. As shown in FIG. 2, the outer diameter of the base portion 192 is equivalent to the outer diameter of the small diameter disc 144. Here, the outer diameter of the small diameter disc 144 is equivalent to the outer diameter of the seat surface 90a of the inner sheet 90, and therefore the outer diameter of the base portion 192 is equivalent to the outer diameter of the seat surface 90a of the inner sheet 90. It has become.

The leg portion 193 extends from the outer peripheral edge portion of the base portion 192 to the outer side in the radial direction of the base portion 192, and the inner inclined portion 201 extending so as to be located on one side in the axial direction of the base portion 192 toward the outer side in the radial direction. The inner inclined portion 201 extends outward from the edge portion on the side opposite to the base portion 192 in the radial direction of the base portion 192, and extends outward in the radial direction so as to be located on the other side in the axial direction of the base portion 192. It has an outer inclined portion 202 and a contact portion 203 extending outward in the radial direction of the base portion 192 from an end edge portion on the side opposite to the inner inclined portion 201 of the outer inclined portion 202. The contact portion 203 is in contact with the position between the intermediate seat 91 and the outer seat 92 in the radial direction of the disc valve 141.

The urging member 143 is always in contact with the small diameter disc 144 and the inner peripheral side of the main body portion 152 of the disc valve 141 by clamping the base portion 192 on the inner peripheral side in the axial direction. The urging member 143 is arranged so that the outer inclined portion 202 and the inner inclined portion 201 are located closer to the washer 142 in the axial direction of the base portion 192 than the base portion 192 and the contact portion 203. The urging member 143 urges the disc valve 141 in the direction in which it abuts the outer seat 92 and the intermediate seat 91. In other words, the urging member 143 urges the disc valve 141 in the direction of closing the passage 54. The length of the leg portion 193 of the urging member 143 is such that the leg portion 193 does not abut on the large diameter portion 173 of the washer 142 even when deformed, but abuts on the main body portion 172. The passage in the passage hole 161 of the disc valve 141 always communicates with the passage in the passage hole 181 of the washer 142 via the passage between the adjacent leg 193 and the leg 193 of the urging member 143.

In the valve mechanism 61, when the piston 33 moves to the contraction side and the pressure in the second chamber 35 becomes higher than the pressure in the first chamber 34, the piston speed increases in the damping force characteristic on the contraction side shown in the lower side of FIG. In the very low speed region (0 to v1), the oil liquid flows from the second chamber 35 to the first chamber 34 through the fixed orifice 166 in the passage groove 165 formed in the piston 33. As a result, a damping force of the orifice characteristic is generated.

In the low speed region (v1 to v2) in which the piston speed is faster than the very low speed region, the difference between the pressure of the second chamber 35 applied to the disc valve 141 via the passage 54 and the pressure of the first chamber 34 applied to the disc valve 141. As shown in FIG. 7, the disc valve 141 deforms while deforming the leg portion 193 of the urging member 143 due to the pressure, and the main portion 152 of the disc valve 141 is in contact with the seat surface of the outer seat 92 until then. Leave the seat from 92a. Then, the oil liquid from the passage 54 flows into the first chamber 34 through the passage between the outer seat 92 and the disc valve 141. As a result, the damping force of the valve characteristic is generated.

Then, when the piston speed becomes a high speed region (v2 to) faster than the low speed region, the disc valve 141 comes into contact with the large diameter portion 173 of the washer 142 and its deformation is restricted, so that the disc valve 141 becomes The damping force is harder than in the low speed region where the washer 142 is not in contact with the washer 142.

At this time, in the disc valve 141 of the first embodiment, since a plurality of large diameter portions 153 and a plurality of small diameter portions 154 are formed over the entire circumference to form an uneven shape, the outer peripheral portion is formed thereby. Due to the plurality of recesses 158, the oil liquid flows at a larger flow rate, and the generated differential pressure becomes smaller. As a result, it is possible to prevent the damping force from becoming an excessively hard characteristic from the state shown by the solid line in FIG. 6 to the state shown by the broken line. A part of the oil liquid that has passed through the passages in the plurality of recesses 158 flows to the first chamber 34 through the passages in the recesses 178 of the washer 142.

The above-mentioned Patent Documents 1 to 3 describe a shock absorber that buffers vibration of a vehicle or the like. In such a shock absorber, from the viewpoint of preventing damage or the like, there is one that regulates the deformation of the disc valve beyond a predetermined value by contacting it with the washer. In this way, if the deformation of the disc valve beyond a predetermined value is regulated by contacting it with the washer, the damping force becomes excessively hard when the piston speed increases while the disc valve is in contact with the washer. There is a possibility of becoming.

On the other hand, in the fluid pressure shock absorber 10 of the first embodiment, a plurality of large-diameter portions 153 and a plurality of small-diameter portions 154 are formed on the outer peripheral portion of the disc valve 141 to form an uneven shape. Since the recesses 158 of the above are formed, the oil liquid can be flowed at a larger flow rate by the plurality of recesses 158 in the high speed region of the piston speed as compared with the case where the concave and convex shapes are not formed. Therefore, even if the washer 142 regulates the valve opening direction of the disc valve 141 from the viewpoint of preventing damage, the damping force in the high speed region of the piston speed is compared with the case where the plurality of recesses 158 are not formed. Can be suppressed from becoming an excessively hard characteristic.

Further, since the urging member 143 for urging the disc valve 141 in the direction of closing the passage 54 is provided between the disc valve 141 and the washer 142, the passage 54 can be properly closed by the disc valve 141. ..

In the above, as shown in FIG. 2, a passage groove 165 is formed in the outer seat 92 of the piston 33, and the disc valve 141 contacts the seat surface 92a of the outer seat 92 in the passage in the passage groove 165. Even in this state, the fixed orifice 166 is used so that the first chamber 34 and the passage 54, that is, the second chamber 35 are always communicated with each other. However, as shown in FIG. The fixed orifice 215 may be provided in the disc valve 141 without forming the disc valve 141.

In this case, as shown in FIG. 9, the outer peripheral portion of the main body portion 152 is formed on the outer peripheral portion of the disc valve 141 between the predetermined large diameter portion 153 and the predetermined large diameter portion 153 adjacent to each other in the circumferential direction. A small diameter portion 154 (one small diameter portion) is formed, and the outer diameter of the disc valve 141 in the radial direction is a small diameter portion between another predetermined large diameter portion 153 adjacent in the circumferential direction and the predetermined large diameter portion 153. A small diameter portion 211 (another small diameter portion) having a diameter smaller than 154 is formed. In the example shown in FIG. 9, one small diameter portion 211 is located between two adjacent small diameter portions 154 in the circumferential direction of the disc valve 141 and two adjacent small diameter portions 154 in the circumferential direction of the disc valve 141. Is forming. In addition, although the example in which one small diameter portion 211 is formed between two adjacent small diameter portions 154 in the circumferential direction of the disc valve 141 is shown, the present invention is not limited to this, and may be arbitrarily determined. ..

The small diameter portion 211 is provided on the outer peripheral portion of the disc valve 141 and forms the bottom portion of the recess 213 which is recessed inward in the radial direction of the disc valve 141 from the protruding tip portion of the large diameter portion 153. Therefore, the outer peripheral portion of the disc valve 141 has a concave-convex shape in which a plurality of large-diameter portions 153 and a plurality of small-diameter portions 154 and 211 are formed over the entire circumference.

As shown in FIG. 8, the small diameter portion 211 of the disc valve 141 has an outer diameter of the disc valve 141 in the radial direction smaller than the inner diameter of the seat surface 92a of the outer seat 92. Therefore, the disc valve 141 constitutes a fixed orifice 215 in which the passage in the recess 213 in which the bottom is formed by the small diameter portion 211 always communicates with the first chamber 34 and the passage 54, that is, the second chamber 35.

In the disc valve 141, one of the small diameter portions 154,211 on the outer side in the radial direction of the disc valve 141 is seated on the outer seat 92 in the same manner as described above, and the disc valve 141 is in the radial direction of the disc valve 141. The other inner small diameter portion 211 in the above is not seated on the outer seat 92. In other words, with respect to one small diameter portion 154 seated on the outer seat 92 of the small diameter portions 154 and 211, the other small diameter portion 211 is formed inward in the radial direction of the disc valve 141 rather than the small diameter portion 154. It is not seated on the outer seat 92.

That is, when the fixed orifice 166 is provided on the piston 33 side as shown in FIG. 2, all the small diameter portions 154 of the disc valve 141 can be seated on the outer seat 92, but the disc valve 141 can be seated as shown in FIG. When the fixed orifice 215 is provided on the side, even if a part of the small diameter portions 154 of all the small diameter portions 154 and 211 can be seated on the outer seat 92, another one for forming the fixed orifice 215. The small diameter portion 211 of the portion is not seated on the outer seat 92.

In this way, with respect to one small diameter portion 154 seated on the outer seat 92 of the small diameter portions 154 and 211, the other small diameter portion 211 is moved inward in the radial direction of the disc valve 141 from the small diameter portion 154. By forming the fixed orifice 215, the fixed orifice 215 can be provided on the disc valve 141 side. Therefore, the recess 213 for forming the fixed orifice 215 can be easily formed at the time of press forming of the disc valve 141.

[Second Embodiment]
Next, the second embodiment will be described mainly based on FIG. 10, focusing on the differences from the first embodiment. The parts common to the first embodiment are represented by the same name and the same reference numerals.

In the second embodiment, instead of the disc valve 141 of the first embodiment, a disc valve 141A which is partially different from the disc valve 141 is provided. Therefore, the second embodiment has a valve portion 98A different from the valve portion 98 in that it has a disc valve 141A different from that of the first embodiment, and has a disc valve 141A different from that of the first embodiment. Has a valve mechanism 61A different from the valve mechanism 61.

As shown in FIG. 10, the disc valve 141A has a flat shape in which a fitting hole 151 that fits into the mounting shaft portion 41 of the rod 38 is formed in the center in the radial direction instead of the main portion 152 of the first embodiment. A perforated disc-shaped base portion 221 and an inner taper that tapers outward from the outer peripheral edge portion of the base portion 221 in the radial direction of the base portion 221 so as to be located on one side of the base portion 221 in the axial direction toward the outside. Tapered from the outer peripheral edge of the inner tapered portion 222 opposite to the base portion 221 to the outer side in the radial direction of the base portion 221 and to the outer side in the axial direction of the base portion 221. It has a widening outer tapered portion 223 and a perforated disc-shaped closing portion 224 that extends outward in the radial direction of the base portion 221 from the outer peripheral edge portion on the side opposite to the inner tapered portion 222 of the outer tapered portion 223. There is.

The closed portion 224 includes a small diameter portion 154 in the outer peripheral edge portion, and a large diameter portion 153 projects radially outward from the outer peripheral edge portion of the closed portion 224. The base portion 221 and the inner tapered portion 222, the outer tapered portion 223, and the closing portion 224 are arranged coaxially.

In the disc valve 141A, the outer diameter of the base portion 221 is equal to the outer diameter of the base portion 192 of the urging member 143, the outer diameter of the small diameter disc 144, and the outer diameter of the seat surface 90a of the inner seat 90. The closing portion 224 sits on the seat surface 91a of the intermediate seat 91 of the piston 33 and the seat surface 92a of the outer seat 92 and closes the aisle 54.

The disc valve 141A is formed with a passage hole 161A that penetrates the outer tapered portion 223 and always communicates with the passage 58. Similar to the passage hole 161 of the first embodiment, the passage holes 161A have an arc shape, and a plurality of passage holes 161A are provided at intervals in the circumferential direction of the disc valve 141A. The aisle hole 161A is arranged so that the outer end position of the disc valve 141A in the radial direction is the boundary position between the outer tapered portion 223 and the closing portion 224, and the inner peripheral edge portion and the outer peripheral edge portion of the seat surface 91a of the intermediate seat 91. It is located at the position on the outer peripheral edge side of the range between and. In other words, the radial inner end portion of the closing portion 224 is seated at a position on the outer peripheral edge portion side of the range between the inner peripheral edge portion and the outer peripheral edge portion of the seat surface 91a of the intermediate seat 91. Also in the disc valve 141A, the small diameter portion 154 forming the outer peripheral portion of the closing portion 224 is seated at a position on the inner peripheral edge side in the range between the inner peripheral edge portion and the outer peripheral edge portion of the seat surface 92a of the outer seat 92. There is.

The inner tapered portion 222 and the outer tapered portion 223 form a bent portion 228 that bends toward the washer 142 side in the disc valve 141A. The disc valve 141A is formed with a bent portion 228 that bends toward the washer 142 side in a range from the position where the intermediate seat 91 is seated to the position where the inner seat 90 is seated.

According to such a second embodiment, since the disc valve 141A is formed with the bent portion 228 radially inward from the position where the intermediate seat 91 is seated with respect to the intermediate seat 91, the disc valve 141A has a contraction stroke. In, when the seat is separated from the outer seat 92, the seat is easily separated from the intermediate seat 91 due to the shape of the bent portion 228.

Therefore, in the second embodiment, when the piston speed changes from the very low speed region to the low speed region in the contraction stroke, the disc valve 141A separates from the seat surface 92a of the outer seat 92 that has been in contact until then, and from the passage 54. Oil liquid flows into the first chamber 34 through the flow path between the outer seat 92 and the disc valve 141A.

Then, when the piston speed changes from the low speed region to the high speed region, the large diameter portion 153 comes into contact with the washer 142, and further expansion of the flow path between the outer seat 92 and the disc valve 141A is suppressed. Due to the recesses 158 between the large diameter portions 153, the flow path is wider than when there is no recess 158, and the oil liquid can flow at a large flow rate.

Further, at this time, in addition to this aisle, the disc valve 141A is separated from the seat surface 91a of the intermediate seat 91 which has been in contact until then, and the oil liquid from the aisle 54 is separated from the intermediate seat 91. It flows to the first chamber 34 through a gap with the disc valve 141A, a passage in the passage hole 161A, a gap between the legs 193 of the urging member 143, a passage in the passage hole 181 of the washer 142, and the like. Therefore, the disc valve 141A can flow the oil liquid at a larger flow rate, so that the generated differential pressure becomes smaller. Therefore, it is possible to further suppress the damping force from becoming an excessively hard characteristic in the high speed region of the piston speed.

[Third Embodiment]
Next, the third embodiment will be described mainly based on FIGS. 11 to 13, focusing on the differences from the second embodiment. The parts common to the second embodiment are represented by the same name and the same reference numerals.

As shown in FIG. 11, the third embodiment is provided with a disc valve 141B which is partially different from the disc valve 141A of the second embodiment. Therefore, the third embodiment has a valve portion 98B different from the valve portion 98A in that it has a disc valve 141B different from that of the second embodiment, and has a disc valve 141B different from that of the second embodiment. Has a valve mechanism 61B different from the valve mechanism 61A.

The disc valve 141B has the same base portion 221 as the disc valve 141A of the second embodiment, the inner tapered portion 222, the outer tapered portion 223 and the closing portion 224, and has the same diameter as the large diameter portion 153 of the second embodiment. Has a partially different large diameter portion 153B.

The large-diameter portion 153B of the disc valve 141B has the same shape as the large-diameter portion 153 of the second embodiment, and the closed portion is outward from the outer peripheral edge portion of the closed portion 224 in the radial direction of the closed portion 224. It is inclined and protrudes so as to approach the washer 142 side in the axial direction of 224. Therefore, the large diameter portion 153B is bent toward the washer 142 side from the closing portion 224 at its base end. The recess 158B between the adjacent large diameter portions 153B is also inclined in the same manner as the large diameter portion 153B.

In the disc valve 141B as well, the closing portion 224 sits on the seat surface 91a of the intermediate seat 91 of the piston 33 and the seat surface 92a of the outer seat 92 to close the aisle 54. The small diameter portion 154 constitutes the outer peripheral edge portion of the closing portion 224, and is in contact with the radial inner end side of the seat surface 92a of the outer sheet 92.

According to such a third embodiment, in the disc valve 141B, since the large diameter portion 153B is bent toward the washer 142 side, the closing portion 224 is separated from the outer seat 92 in the contraction stroke. When the large diameter portion 153B abuts on the washer 142 as shown in FIG. 12, further deformation of the disc valve 141B is suppressed. Further, as shown in FIG. 12, when the large diameter portion 153B abuts on the washer 142, the closing portion 224 is also separated from the intermediate seat 91 due to the shape of the bent portion 228. Further, when the disc valve 141B is further deformed toward the washer 142 while the large diameter portion 153B is in contact with the washer 142, the disc valve 141B is deformed with the tip of the large diameter portion 153B in contact with the washer 142 as a fulcrum. Then, as shown in FIG. 13, the intermediate sheet 91 is further separated.

Therefore, in the third embodiment, when the piston speed changes from the very low speed region to the low speed region in the contraction stroke, the disc valve 141B separates from the seat surface 92a of the outer seat 92 that has been in contact until then, and from the passage 54. Oil liquid flows into the first chamber 34 through the flow path between the outer seat 92 and the disc valve 141B.

Then, when the piston speed changes from the low speed region to the high speed region, the large diameter portion 153B abuts on the washer 142, and further expansion of the flow path between the outer seat 92 and the disc valve 141B is suppressed. Due to the recess 158B between the large diameter portions 153B, the flow path is wider than when there is no recess 158B, and the oil liquid can flow at a large flow rate. Further, at this time, in addition to this aisle, the closing portion 224 is separated from the seat surface 91a of the intermediate seat 91 which has been in contact until then, and the oil liquid from the aisle 54 is discharged from the intermediate seat 91 and the disc valve 141B. It flows to the first chamber 34 through the gap between the and the passage hole 161A, the gap between the legs 193 of the urging member 143, and the passage in the passage hole 181 of the washer 142.

Further, in the high speed region where the piston speed is high, the disc valve 141B is deformed more greatly, and as shown in FIG. 13, the large diameter portion 153B comes into contact with the large diameter portion 173 of the washer 142 by surface contact. The flow path between the outer seat 92 and the disc valve 141B including the plurality of recesses 158B is widened. Further, the flow path of the gap between the intermediate sheet 91 and the closing portion 224 is also widened. Therefore, the disc valve 141B can further increase the flow rate of the oil liquid flowing into the first chamber 34, so that the generated differential pressure is further reduced. Therefore, it is possible to further suppress the damping force from becoming an excessively hard characteristic in the high speed region of the piston speed.

[Fourth Embodiment]
Next, the fourth embodiment will be described mainly based on FIG. 14, focusing on the differences from the first embodiment. The parts common to the first embodiment are represented by the same name and the same reference numerals.

As shown in FIG. 14, the fourth embodiment is provided with a disc valve 141C which is partially different from the disc valve 141 of the first embodiment. Therefore, the fourth embodiment has a valve portion 98C different from the valve portion 98 in that it has a disc valve 141C different from that of the first embodiment, and has a disc valve 141C different from that of the first embodiment. Has a valve mechanism 61C different from the valve mechanism 61.

The disc valve 141C has a main body portion 152C that is partially different from the main body portion 152 of the disc valve 141 of the first embodiment, and has a large diameter portion 153C that is partially different from the large diameter portion 153 of the first embodiment. Have.

The main body portion 152C is formed with a passage hole 161C that penetrates the main body portion 152C in the axial direction and always communicates with the passage 58. Similar to the passage hole 161 of the first embodiment, the passage holes 161C have an arc shape, and a plurality of passage holes 161C are provided at intervals in the circumferential direction of the disc valve 141C. The aisle hole 161C is arranged so that the outer end position of the disc valve 141C in the radial direction is located on the outer peripheral edge side of the range between the inner peripheral edge portion and the outer peripheral edge portion of the seat surface 91a of the intermediate seat 91.

The large-diameter portion 153C includes a base end-side extension portion 241 extending from the outer peripheral edge portion including the small-diameter portion 154 of the main body portion 152C to the washer 142 side along the axial direction of the main body portion 152C, and a base end-side extension portion. It has a tip-side extending portion 242 that extends outward in the radial direction of the main body portion 152C from an edge portion on the opposite side of the main body portion 152C of 241. Therefore, the large diameter portion 153C is bent from the main body portion 152C toward the washer 142 side. As a result, the recess 158C between the large diameter portions 153C also has a shape different from that of the recess 158 of the first embodiment.

According to the fourth embodiment, since the large diameter portion 153C of the disc valve 141C is bent toward the washer 142 side, the disc valve 141C is separated from the outer seat 92 in the contraction stroke and the large diameter portion 153C is separated from the outer seat 92. When it comes into contact with the washer 142, it suppresses further deformation of the disc valve 141C. When a larger differential pressure is generated from this state, the disc valve 141C deforms with the tip end side extending portion 242 of the large diameter portion 153C in contact with the washer 142 as a fulcrum, and easily separates from the intermediate seat 91. It will be.

Therefore, in the fourth embodiment, when the piston speed changes from the very low speed region to the low speed region in the contraction stroke, the disc valve 141C separates from the seat surface 92a of the outer seat 92 that has been in contact until then, and from the passage 54. Oil liquid flows into the first chamber 34 through the flow path between the outer seat 92 and the disc valve 141C.

Then, when the piston speed changes from the low speed region to the high speed region, the large diameter portion 153C abuts on the washer 142, and further expansion of the flow path between the outer seat 92 and the disc valve 141B is suppressed. Due to the recess 158C between the large diameter portions 153C, the flow path is wider than when there is no recess 158C, and the oil liquid can flow at a large flow rate. At this time, in addition to this aisle, the disc valve 141C is separated from the seat surface 91a of the intermediate seat 91 that has been in contact with the aisle, and the oil liquid from the aisle 54 is discharged from the intermediate seat 91 and the disc valve 141C. It flows to the first chamber 34 through the gap between the and the passage hole 161C, the gap between the legs 193 of the urging member 143, and the passage in the passage hole 181 of the washer 142. Therefore, the disc valve 141C can flow the oil liquid at a larger flow rate, so that the generated differential pressure becomes smaller. Therefore, it is possible to further suppress the damping force from becoming an excessively hard characteristic in the high speed region of the piston speed.

[Fifth Embodiment]
Next, the fifth embodiment will be described mainly based on FIGS. 15 and 16, focusing on the differences from the first embodiment. The parts common to the first embodiment are represented by the same name and the same reference numerals.

As shown in FIGS. 15 and 16, the fifth embodiment is provided with a disc valve 141D which is partially different from the disc valve 141 of the first embodiment. Therefore, the fifth embodiment has a valve portion 98D different from the valve portion 98 in that it has a disc valve 141D different from that of the first embodiment, and has a disc valve 141C different from that of the first embodiment. Has a valve mechanism 61D different from the valve mechanism 61.

The disc valve 141D has a main body portion 152D that is partially different from the main body portion 152 of the disc valve 141 of the first embodiment.

The main body portion 152D is formed with a passage hole 161D that penetrates the main body portion 152D in the axial direction and always communicates with the passage 58. Similar to the passage hole 161 of the first embodiment, the passage holes 161D have an arc shape, and a plurality of passage holes 161D are provided at intervals in the circumferential direction of the disc valve 141D. The aisle hole 161D is arranged so that the outer end position of the disc valve 141D in the radial direction is located on the outer peripheral edge side of the range between the inner peripheral edge portion and the outer peripheral edge portion of the seat surface 91a of the intermediate seat 91.

The main body portion 152D is formed with a curved portion 251 outside the disc valve 141D in the radial direction with respect to the passage hole 161D. The curved portion 251 has an arcuate cross section on the surface including the central axis of the main body portion 152D, protrudes from the surface of the main body portion 152D on the washer 142 side toward the washer 142 side, and is opposite to the washer 142 of the main body portion 152D. It is dented from the side surface toward the washer 142 side. The curved portion 251 is formed at a position between the outer peripheral edge portion of the seat surface 91a of the intermediate sheet 91 and the inner peripheral edge portion of the seat surface 92a of the outer sheet 92.

As shown in FIG. 16, the curved portion 251 is an annular shape centered on the central axis of the main body portion 152D, and is continuously formed over the entire circumference of the main body portion 152D. A plurality of large diameter portions 153, a plurality of small diameter portions 154, and a plurality of recesses 158 are provided on the outer side of the disc valve 141D in the radial direction from the curved portion 251.

As shown in FIG. 15, the leg portion 193 of the urging member 143 is in contact with the curved portion 251 at the contact portion 203 with the main body portion 152D. Since the urging member 143 abuts on the curved portion 251 protruding toward the washer 142 side, the inner inclined portion 201 and the outer inclined portion 202 are deformed so as to form a substantially linear shape.

In such a fifth embodiment, in the contraction stroke, in the low piston speed region, the curved portion 251 of the disc valve 141D is attached due to the differential pressure between the passage 54 side and the first chamber 34 side applied to the disc valve 141D. The portion of the leg portion 143 of the force member 143 that is in contact with the contact portion 203 is deformed as a fulcrum, and the portion outside the curved portion 251 of the main portion 152D of the disc valve 141 is the outer seat that has been in contact until then. The seat is separated from the seat surface 92a of 92. Then, the oil liquid from the passage 54 flows into the first chamber 34 through the flow path between the outer seat 92 and the disc valve 141D.

When the piston speed becomes a high speed region faster than the low speed region, the large diameter portion 153 abuts on the washer 142 to suppress further expansion of the flow path between the outer seat 92 and the disc valve 141D. However, due to the recesses 158 between the large diameter portions 153, the flow path is wider than when there is no recess 158, and the oil liquid can flow at a large flow rate. Further, at this time, in the disc valve 141D, the portion of the main body portion 152D between the leg portions 193 that is not in contact with the leg portion 193 is deformed toward the washer 142 side and is separated from the seat surface 91a of the intermediate seat 91. .. Therefore, in addition to the flow path between the disc valve 141D and the outer seat 92 described above, the disc valve 141D has a passageway between the flow path between the intermediate seat 91 and the passageway hole 161D, a passageway between the legs 193, and a passageway hole 181. The oil liquid is flowed to the first chamber 34 through the passage through the passage. Therefore, the disc valve 141D can flow the oil liquid at a larger flow rate, so that the generated differential pressure becomes smaller. Therefore, it is possible to further suppress the damping force from becoming an excessively hard characteristic in the high speed region of the piston speed.

Also in the second to fifth embodiments, as described in the first embodiment, the disc valves 141A, 141B, 141C, 141D are not set by forming the passage groove 165 in the piston 33 to set the fixed orifice 166. A fixed orifice 215 may be set by forming a recess 213 including a small diameter portion 211 on the side.

In the above embodiment, the valve mechanism 61 on the contraction side provided on the piston 33 as a partition member that defines the first chamber 34 and the second chamber 35 in the cylinder 11 has been described as an example, but the present invention has been described. It can also be applied to the valve mechanism 62 on the extension side of the piston 33. Further, it can also be applied to the valve mechanism 81 on the contraction side of the base member 27 as a partition member that defines the second chamber 35 and the reservoir chamber 13 in the cylinder 11, and the valve mechanism on the extension side of the base member 27. It is also possible to apply to 82.

The first aspect of the above-described embodiment is a cylinder in which a working fluid is sealed, a partition member that defines two chambers in the cylinder and has a passage capable of communicating between the two chambers, and the above-mentioned. A rod extending to the outside of the cylinder, a first sheet provided on the chamber side of at least one of the two chambers of the partition member and formed radially inside the passage, and a radial direction from the passage. A disc valve that sits on a second seat formed on the outside and opens and closes the passage, and a washer that is provided on the side opposite to the partition member of the disc valve and regulates the valve opening direction of the disc valve. A fluid pressure shock absorber having the above, wherein the outer peripheral portion of the disc valve has a concave-convex shape in which a plurality of large-diameter portions and a plurality of small-diameter portions are formed over the entire circumference, and among the small-diameter portions. At least one small diameter portion is seated on the second seat. This makes it possible to prevent the damping force from becoming an excessively hard characteristic.

In the second aspect, in the first aspect, the other small diameter portion of the small diameter portion is formed inward in the radial direction from the one small diameter portion. This makes it possible to form a fixed orifice in the disc valve, including other small diameter portions.

In the third aspect, in the first or second aspect, the disc valve is bent in the radial direction from the position where the disc valve is seated to the washer side. The part is formed. As a result, the disc valve can be easily separated from the first seat.

In the fourth aspect, in any one of the first to third aspects, an urging member for urging the disc valve in the direction of closing the passage is provided between the disc valve and the washer. As a result, the passage can be properly closed by the disc valve.

In the fifth aspect, in any one of the first to fourth aspects, since the large diameter portion is bent toward the washer side, the large diameter portion abuts on the washer to deform the disc valve. It can be suppressed.

10 Fluid pressure shock absorber 11 Cylinder 33 Piston (partition member)
34 Room 1 (one room)
35 Room 2 38 Rod 54 Aisle 91 Intermediate seat (1st seat)
92 Outer sheet (second sheet)
141, 141A to 141D Disc valve 142 Washer 143 Biasing member 153, 153B, 153C Large diameter part 154 Small diameter part (one small diameter part)
211 Small diameter part (other small diameter part)
228 bend

Claims (5)

A cylinder in which the working fluid is sealed and
A partition member that defines two chambers in the cylinder and has a passage that can communicate between the two chambers.
A rod extending to the outside of the cylinder and
A first sheet provided on the chamber side of at least one of the two chambers of the partition member and formed radially inside the passage and a second sheet formed radially outside the passage. A disc valve that sits down and opens and closes the aisle,
A washer provided on the side of the disc valve opposite to the partition member and regulating the valve opening direction of the disc valve.
Is a fluid pressure shock absorber with
The outer peripheral portion of the disc valve has a concave-convex shape in which a plurality of large-diameter portions and a plurality of small-diameter portions are formed over the entire circumference.
A fluid pressure shock absorber characterized in that at least one small diameter portion of the small diameter portions is seated on the second seat. The fluid pressure shock absorber according to claim 1.
A fluid pressure shock absorber characterized in that the other small diameter portion of the small diameter portion is formed inward in the radial direction from the one small diameter portion. The fluid pressure shock absorber according to claim 1 or 2.
The fluid pressure shock absorber is characterized in that the disc valve is formed with a bent portion that bends toward the washer side in the radial direction from the position where the first seat is seated. .. The fluid pressure shock absorber according to any one of claims 1 to 3.
A fluid pressure shock absorber characterized in that an urging member for urging the disc valve in a direction of closing the passage is provided between the disc valve and the washer. The fluid pressure shock absorber according to any one of claims 1 to 4.
A fluid pressure shock absorber characterized in that the large diameter portion is bent toward the washer side.

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