JP6384999B2 - Fluid pressure buffer - Google Patents

Description

  The present invention relates to a fluid pressure shock absorber.

  In some fluid pressure shock absorbers, a valve lift member is disposed opposite to a suction valve. The valve lift member is provided with a plurality of protrusions on the suction valve side at intervals in the circumferential direction of the suction valve, and these protrusions are disposed so as to form a gap with the suction valve ( For example, see Patent Document 1).

JP 2010-276103 A

  If a clearance is provided between the valve lift member and the suction valve, the sealing performance of the suction valve will be reduced, and the damping force of the fluid pressure shock absorber may vary, especially in the region where the piston speed is extremely low. There is.

  Therefore, an object of the present invention is to provide a fluid pressure shock absorber capable of generating a stable damping force.

To achieve the above object, a fluid pressure shock absorber according to the present invention, the lower chamber side of the valve body, the flow passage forming an annular groove forming a flow channel is formed, and the valve body of the suction valve Has a spring member on the opposite side, the spring member having an annular main plate portion and an annular outer peripheral plate portion extending radially outwardly, and between the main plate portion and the outer peripheral plate portion. A support convex portion that protrudes toward the suction valve side in the axial direction of the valve body from the main plate portion and that presses the suction valve over the entire circumference is formed, and the support convex portion is the spring member in the radial direction of the spring member. It has a structure you contact to the flow path forming within the groove.

  According to the present invention, a stable damping force can be generated.

It is a fragmentary sectional view showing the fluid pressure buffer of a 1st embodiment concerning the present invention. It is sectional drawing which shows the valve body periphery of the fluid pressure buffer of 1st Embodiment which concerns on this invention. It is an expanded sectional view showing the important section of the fluid pressure buffer of a 1st embodiment concerning the present invention. It is a top view of the spring member of the fluid pressure shock absorber according to the first embodiment of the present invention. It is sectional drawing which shows the valve body periphery of the fluid pressure buffer of 2nd Embodiment which concerns on this invention.

“First Embodiment”
A first embodiment according to the present invention will be described below with reference to FIGS.

  A fluid pressure shock absorber 10 according to 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 railway vehicle. The fluid pressure shock absorber 10 has oil as working fluid between a cylindrical cylinder 11 in which oil liquid as working fluid is sealed and a cylinder 11 having a larger diameter than the cylinder 11 and provided on the outer peripheral side of the cylinder 11. It has a bottomed cylindrical outer cylinder 13 that forms a reservoir chamber 12 in which liquid and gas are enclosed. That is, the fluid pressure shock absorber 10 has a double cylinder structure.

  The outer cylinder 13 is fitted into an inner side of an opening on the other end side of the body member 14 and a metal body member 14 made of a substantially cylindrical member whose one end and the other end are opened. The bottomed cylindrical metal closing member 15 is closed. The cylindrical portion 16 and the barrel member 14 that are fitted to the barrel member 14 of the closing member 15 become the cylinder portion 17 of the outer cylinder 13, and the bottom portion 18 that is not fitted to the barrel member 14 of the closure member 15 is the bottom portion of the outer cylinder 13. It is 18. The closing member 15 is fixed to the body member 14 so as to be sealed by welding. The outer cylinder 13 is provided coaxially with the cylinder 11 and covers the cylinder 11 on the outer side in the radial direction. Although only a part is shown in FIG. 1, an annular mounting eye 19 is fixed to the outside of the closing member 15.

  The cylinder 11 is made of a metal cylindrical member whose one end and the other end are open. The cylinder 11 is engaged with the bottom portion 18 of the outer cylinder 13 via an annular metal valve body 21 attached to the other end portion in the axial direction. The cylinder 11 is connected to the opposite side of the bottom portion 18 of the cylindrical portion 17 of the outer cylinder 13 through a rod guide (not shown) attached to one end portion in the axial direction. The rod guide is fitted to both the cylinder 11 and the outer cylinder 13 to support one end of the cylinder 11 in the axial direction coaxially with the outer cylinder 13.

  The valve body 21 is fitted and attached to the other end portion of the cylinder 11, and the side opposite to the axial cylinder 11 is placed on the bottom portion 18 of the outer cylinder 13. In this mounted state, the valve body 21 engages with the annular step portion 22 of the bottom portion 18 and is arranged coaxially with the outer cylinder 13, whereby the other end portion of the cylinder 11 in the axial direction is removed. Arranged coaxially with the tube 13.

  A piston 25 is slidably provided in the cylinder 11. The piston 25 divides the inside of the cylinder 11 into an upper chamber 28 and a lower chamber 29. The upper chamber 28 is provided on the side opposite to the bottom 18 from the piston 25 in the cylinder 11, that is, on the one side in the axial direction, and the lower chamber 29 is positioned on the bottom 18 side in the cylinder 11, that is, on the other side in the axial direction. Is provided. The lower chamber 29 in the cylinder 11 is separated from the reservoir chamber 12 including the space between the valve body 21 and the bottom 18 by a valve body 21 provided at the other end of the cylinder 11.

  The piston 25 includes a metal ring-shaped piston main body 33 and a synthetic resin sliding member 34 mounted coaxially on the outer periphery thereof. The sliding member 34 slides in the cylinder 11. Move. The piston 25 is connected to a piston main body 33 with a metal piston rod 31. One end of the piston rod 31 protrudes from one end of the cylinder 11 through a rod guide (not shown) and a seal member (not shown) outside the cylinder 11, and the other end is connected to the piston body 33. The piston 25 is fastened to the piston rod 31 by a nut 32 and moves integrally with the piston rod 31. In the fluid pressure shock absorber 10, for example, the piston rod 31 is connected to the vehicle body side of the vehicle and the mounting eye 19 is connected to the wheel side of the vehicle to generate a damping force with respect to the movement of the wheel relative to the vehicle body.

  The piston rod 31 has a main shaft portion 35 having a constant diameter and an inner end shaft portion 36 on the end portion on the side inserted into the cylinder 11. The inner end shaft portion 36 has a smaller diameter than the main shaft portion 35, and a male screw 37 is formed on the outer peripheral portion opposite to the main shaft portion 35.

  The piston body 33 is formed with a through hole 39 penetrating in the axial direction in the center in the radial direction to form an annular shape. In addition, a plurality of flow path forming holes 41 are formed. The piston main body 33 is provided with a plurality of flow path forming holes 40 on the inner side and a plurality of flow path forming holes 41 on the outer side of the flow path forming holes 40 in the radial direction.

  The plurality of flow path forming holes 40 are formed at equal intervals in the circumferential direction of the piston body 33 at positions equidistant from the center of the piston body 33. On the side of the upper chamber 28 in the axial direction of the piston main body 33, a flow path forming groove 42 for communicating the plurality of flow path forming holes 40 is formed in an annular shape centering on the center of the piston main body 33. Also in the lower chamber 29 side in the axial direction, a flow path forming groove 43 for communicating a plurality of flow path forming holes 40 is formed in an annular shape centering on the center of the piston body 33. The inner side of each of the plurality of flow path forming holes 40, the flow path forming grooves 42, and the flow path forming grooves 43 is a flow path 44 that can communicate with the upper chamber 28 and the lower chamber 29.

  The plurality of flow path forming holes 41 are formed at equal intervals in the circumferential direction of the piston main body 33 at positions equidistant from the center of the piston main body 33. On the side of the upper chamber 28 in the axial direction of the piston main body 33, a flow path forming groove 46 that communicates the plurality of flow path forming holes 41 is formed in an annular shape centering on the center of the piston main body 33. The inner side of each of the plurality of flow path forming holes 41 and the flow path forming grooves 46 is a flow path 47 that allows the upper chamber 28 and the lower chamber 29 to communicate with each other.

  The piston 25 is provided with a disk valve 50 made of a plurality of annular flat plate-shaped metal disks capable of closing the flow path 44 by contacting the piston main body 33 on the lower chamber 29 side in the axial direction. ing. On the side opposite to the upper chamber 28 in the axial direction of the disk valve 50, a single annular flat metal disk 51 is provided, and the side of the disk 51 opposite to the upper chamber 28 in the axial direction. Is provided with a single annular flat plate-shaped metal regulating disk 52.

  The piston 25 is provided with a single annular flat plate-shaped metal disk valve 54 that can close the flow path 47 by contacting the piston body 33 on the axial upper chamber 28 side. Yes. On the opposite side of the disk valve 54 from the bottom 18 in the axial direction, a single circular flat plate-shaped metal disk 55 is provided, and on the opposite side of the disk 55 from the bottom 18 in the axial direction. One annular metal regulation disk 57 is provided.

  The restriction disk 57, the disk 55, the disk valve 54, the piston 25, the disk valve 50, the disk 51, and the restriction disk 52 are arranged in this order while passing the inner end shaft part 36 of the piston rod 31 inward, and the inner end of the main shaft part 35. It is arranged on the end surface on the shaft portion 36 side. These are sandwiched between the nut 32 screwed into the male screw 37 of the inner end shaft portion 36 and the end surface of the main shaft portion 35 on the inner end shaft portion 36 side, and are attached to the piston rod 31.

  The disc valve 50 has an outer diameter larger than the maximum diameter of the flow path forming groove 43 and larger than the disc 51, and is deformed so that an outer portion of the disc 51 is separated from the piston 25 in the axial direction. By doing so, the flow path 44 is opened. The restricting disc 52 has an outer diameter that is substantially the same as the outer diameter of the disc valve 50 and is more rigid than the disc valve 50. When the disc valve 50 is deformed and abuts in a direction away from the piston 25, a disc larger than that disc. The deformation of the valve 50 is restricted.

  The outer diameter of the disk valve 54 is larger than the maximum diameter of the flow path forming groove 46 and larger than the outer diameter of the disk 55. The disk valve 54 opens the flow path 47 by being deformed so that the outer portion of the disk 55 is separated from the piston 25 in the axial direction.

  The restricting disc 57 includes an end surface of the main shaft portion 35 on the inner end shaft portion 36 side, a flat plate-shaped main plate portion 60 sandwiched between the disc 55, and a disc valve that is on the outer peripheral side and more axial than the main plate portion 60 An annular step portion 61 offset in a step shape is provided on the 54 side. The restricting disc 57 has an outer diameter that is substantially the same as the outer diameter of the disc valve 54 and is more rigid than the disc valve 54. When the disc valve 54 is deformed and abuts in a direction away from the piston 25, the disc is larger than that. The deformation of the valve 54 is restricted. In order to make the flow path 44 communicate with the upper chamber 28 at all times, the disc valve 54 is formed with a through hole 62 penetrating in the axial direction, and the regulation disc 57 is formed with a through hole 63 penetrating in the axial direction. ing.

  The disc valve 50 allows the flow of the oil liquid from the upper chamber 28 to the lower chamber 29 through the flow path 44 while restricting the flow of the oil liquid through the flow path 44 in the opposite direction. The disc valve 50 opens the flow path 44 when the piston rod 31 moves to the extension side and the piston 25 moves to the upper chamber 28 side and the pressure in the upper chamber 28 becomes higher than the pressure in the lower chamber 29 by a predetermined value or more. At that time, a damping force is generated. That is, the disk valve 50 is an expansion-side damping valve.

  The disc valve 54 allows the flow of the oil liquid from the lower chamber 29 to the upper chamber 28 side through the flow path 47 while restricting the flow of the oil liquid through the flow path 47 in the opposite direction. The disc valve 54 opens the flow path 47 when the piston rod 31 moves to the contraction side and the piston 25 moves to the lower chamber 29 side and the pressure in the lower chamber 29 becomes higher than the pressure in the upper chamber 28 by a predetermined value or more. At that time, a damping force is generated. That is, the disk valve 54 is a contraction-side damping valve.

  The valve body 21 is formed with a through hole 65 penetrating in the axial direction in the center in the radial direction. A path forming hole 67 is formed. In the radial direction of the valve body 21, a plurality of flow path forming holes 66 are arranged inside, and a plurality of flow path forming holes 67 are arranged outside the flow path forming holes 66, respectively.

  The plurality of flow path forming holes 66 are formed at equal intervals in the circumferential direction of the valve body 21 at positions equidistant from the center of the valve body 21. On the lower chamber 29 side in the axial direction of the valve body 21, a flow path forming groove 68 for communicating a plurality of flow path forming holes 66 is formed in an annular shape centering on the center of the valve body 21. On the bottom 18 side in the axial direction, that is, on the reservoir chamber 12 side, a flow path forming groove 69 for communicating a plurality of flow path forming holes 66 is formed in an annular shape centering on the center of the valve body 21. The inner side of each of the plurality of flow path forming holes 66, the flow path forming grooves 68, and the flow path forming grooves 69 is a flow path 70 that allows the lower chamber 29 and the reservoir chamber 12 to communicate with each other.

  A plurality of flow path forming holes 67 are formed at equal intervals in the circumferential direction of the valve body 21 at positions equidistant from the center of the valve body 21. On the lower chamber 29 side in the axial direction of the valve body 21, a flow path forming groove 72 that communicates a plurality of flow path forming holes 67 is formed in an annular shape centering on the center of the valve body 21. The inner side of each of the plurality of flow path forming holes 67 and the flow path forming grooves 72 is a flow path 73 capable of communicating the lower chamber 29 and the reservoir chamber 12.

  The valve body 21 has a disk made of a plurality of annular flat metal disks that can close the flow path 70 by contacting the valve body 21 on the axial bottom 18 side, that is, the reservoir chamber 12 side. A valve 75 is provided. On the side opposite to the valve body 21 in the axial direction of the disk valve 75, a single circular flat plate-shaped metal disk 76 is provided, and on the side of the disk 76 opposite to the disk valve 75 in the axial direction. A single annular flat plate-shaped metal regulation disk 77 is provided.

  As shown in FIG. 2, the valve body 21 has a single circular plate-shaped metal suction that can close the flow path 73 by contacting the valve body 21 on the lower chamber 29 side in the axial direction. A valve 80 is provided. An annular metal spring member 82 is provided on the opposite side of the suction valve 80 from the valve body 21 in the axial direction. On the opposite side of the spring member 82 from the axial suction valve 80, a single annular flat metal disk 83 is provided, and on the opposite side of the disk 83 from the axial spring member 82. One annular metal control disk 84 is provided. Therefore, the spring member 82 is disposed on the side opposite to the valve body 21 in the axial direction of the suction valve 80.

  A metal rivet 86 is attached to the valve body 21. The rivet 86 has a shaft portion 87 and a flange portion 88 having a diameter larger than that of the shaft portion 87. The shaft portion 87 of the rivet 86 is inserted in this order inside the regulation disk 77, the disk 76, the disk valve 75, the valve body 21, the suction valve 80, the spring member 82, the disk 83, and the regulation disk 84 in this order. Then, the shaft portion 87 is crimped so that the outer portion of the restricting disc 84 extends radially outward. The caulking portion 89 and the flange portion 88 of the rivet 86 formed by the caulking clamp these from both sides in the axial direction.

  The disc valve 75 has an outer diameter larger than the maximum diameter of the flow path forming groove 69 and larger than the outer diameter of the disc 76, and an outer portion of the disc 76 is axially extended from the valve body 21. The flow path 70 is opened by deforming so as to be separated. The restricting disc 77 has an outer diameter slightly smaller than the outer diameter of the disc valve 75 and larger than the disc 76, is more rigid than the disc valve 75, and the disc valve 75 is away from the valve body 21. When it is deformed and abuts, further deformation of the disc valve 75 is restricted.

  The suction valve 80 has an outer diameter larger than the maximum diameter of the flow path forming groove 72, and the spring member 82 has an outer diameter larger than the disk 83 and slightly smaller than the suction valve 80. It has become. The suction valve 80 opens the flow path 73 by being deformed so that the outer part of the disk 83 is separated from the valve body 21 in the axial direction while deforming the spring member 82. The spring member 82 is a bending force generated by changing the clearance a between the rivet 86 and the suction valve 80 in the radial direction by the caulking force of the rivet 86, and increases the support force to the suction valve 80.

  The restricting disc 84 has a flat plate-shaped main plate portion 90 sandwiched between the crimping portion 89 of the rivet 86 and the disc 83, and a stepped shape on the outer peripheral side and closer to the spring member 82 side in the axial direction than the main plate portion 90. And an annular stepped portion 91 that is offset. The regulating disk 84 has an outer diameter slightly smaller than the outer diameter of the spring member 82, is more rigid than the suction valve 80 and the spring member 82, and the suction valve 80 and the spring member 82 are separated from the valve body 21. When deformed and contacted in the direction, further deformation of the suction valve 80 and the spring member 82 is restricted.

  In order to make the flow path 70 communicate with the lower chamber 29 at all times, the suction valve 80 has a through hole 93 penetrating in the axial direction, and the spring member 82 has a through hole 94 penetrating in the axial direction. Through holes 95 are formed in the disk 84 so as to penetrate the disk 84 in the axial direction. The through holes 93 and 94 are formed only within the range of the flow path forming groove 68 in the radial direction of the suction valve 80 and the spring member 82. The outer diameter of the disk 83 is smaller than the minimum distance from the center of each rivet 86 of the through holes 93, 94, 95.

  Here, as shown in FIG. 4, the plurality of through holes 94 of the spring member 82 have the same shape, and form a circular arc arranged on the same circle with the center of the spring member 82 as the center. 82 are arranged at equal intervals in the circumferential direction. Although not shown, the plurality of through holes 93 of the suction valve 80 have the same shape, and have an arc shape arranged on the same circle with the center of the suction valve 80 as the center, and in the circumferential direction of the suction valve 80. It is arranged at equal intervals.

  The disc valve 75 shown in FIG. 2 allows the flow of the oil liquid from the lower chamber 29 to the reservoir chamber 12 through the flow path 70, but restricts the flow of the oil liquid through the flow path 70 in the opposite direction. To do. In the disk valve 75, the piston rod 31 shown in FIG. Also, when the value becomes higher than a predetermined value, the flow path 70 is opened, and at this time, a compression side damping valve that generates a damping force is formed. The disk valve 75 discharges the oil from the lower chamber 29 to the reservoir chamber 12 in accordance with a decrease in the volume in the cylinder 11 due to the piston rod 31 increasing the amount of entry into the cylinder 11.

  The suction valve 80 is a check valve that allows the flow of the oil liquid from the reservoir chamber 12 to the lower chamber 29 through the flow path 73 while restricting the flow of the oil liquid through the flow path 73 in the opposite direction. is there. That is, the disk-shaped suction valve 80 opens and closes the flow path 73. When the piston rod 31 moves to the extension side to increase the amount of protrusion from the cylinder 11 and the piston 25 moves to the upper chamber 28 side, the pressure in the lower chamber 29 falls below the pressure in the reservoir chamber 12. In this case, the suction valve allows the oil liquid to flow from the reservoir chamber 12 into the lower chamber 29 without substantially generating a damping force. The suction valve 80 replenishes the lower chamber 29 with oil from the reservoir chamber 12 in accordance with an increase in the volume in the cylinder 11 due to the piston rod 31 increasing the amount of protrusion from the cylinder 11.

  As shown in FIG. 2, the spring member 82 includes an annular main plate portion 100 sandwiched between the suction valve 80 and the disk 83, and a suction valve 80 in the axial direction from the outer peripheral edge of the main plate portion 100 to the main plate portion 100. An annular support convex portion 101 that extends outward in the radial direction while projecting to the side, and an annular outer peripheral plate portion 102 that extends outward from the outer peripheral edge portion of the support convex portion 101 in the radial direction. When the spring member 82 is in a natural state before being incorporated into the fluid pressure shock absorber 10, the main plate portion 100 has an annular flat plate shape, and the outer peripheral plate portion 102 is arranged in the same plane as the main plate portion 100. Shape. As shown in FIG. 4, the support convex portion 101 is formed on the outer peripheral side of the spring member 82.

  As shown in FIG. 3, the support convex portion 101 has a circular cross section in a plane including the central axis of the spring member 82, so that the radial width of the spring member 82 becomes narrower toward the protruding tip side. ing. As shown in FIG. 2, the spring member 82 is changed so that the clearance a between the support valve 101 and the suction valve 80 decreases from the support protrusion 101 toward the rivet 86, that is, from the support protrusion 101 toward the inner periphery. Yes. Therefore, in a state where there is no pressure difference between the lower chamber 29 and the reservoir chamber 12, the support convex portion 101 continuously abuts the suction valve 80 that closes the flow path 73 over the entire circumference, so that the suction valve 80 is fully Support continuously over the circumference. The support convex portion 101 is formed within the range of the flow path forming groove 72 in the radial direction of the spring member 82, and the minimum diameter is larger than the maximum distance from the center of the rivet 86 of the through hole 94. Further, the maximum diameter of the support convex portion 101 is equal to or less than the maximum diameter of the main plate portion 90 of the restricting disc 84, that is, the minimum diameter of the step portion 91. The diameter is smaller than the minimum diameter of the nearest flat lower end face.

  When the pressure in the lower chamber 29 falls below the pressure in the reservoir chamber 12 and the differential pressure is applied to the suction valve 80 via the flow path 73, the spring member 82 is supported by the support convex portion 101 over the entire circumference. Is pressed and deformed to open the flow path 73 and allow the oil liquid to flow into the lower chamber 29 through the flow path 73. Further, when the pressure in the lower chamber 29 increases from this state and approaches the pressure in the reservoir chamber 12, the suction valve 80 and the spring member 82 return from elastic deformation, and the suction valve 80 closes the flow path 73. The suction valve 80 is pressed by the spring member 82 to close the flow path 73.

  The suction valve 80 and the spring member 82 have low rigidity and can be easily deformed. Therefore, the suction valve 80 can easily open the flow path 73, and when the pressure in the lower chamber 29 falls below the pressure in the reservoir chamber 12, oil can be immediately supplied from the reservoir chamber 12 to the lower chamber 29. In addition, the suction valve 80 can easily close the flow path 73 and can immediately stop the supply of oil from the reservoir chamber 12 to the lower chamber 29 when the pressure in the lower chamber 29 approaches the pressure in the reservoir chamber 12.

  In Patent Document 1 described above, a plurality of protrusions are provided on the valve lift member at intervals in the circumferential direction of the suction valve, and these protrusions are disposed so as to form a gap between the suction valve and the suction valve. For this reason, the sealing performance of the suction valve is lowered, and there is a possibility that the damping force of the fluid pressure shock absorber may vary particularly in a region where the piston speed is extremely low.

  On the other hand, in the fluid pressure shock absorber 10 of the first embodiment, since the support convex portion 101 that supports the suction valve 80 over the entire circumference is formed on the outer circumferential side of the spring member 82, the sealing performance of the suction valve 80. Can be suppressed, and variations in damping force can be suppressed. Therefore, it is possible to generate a stable damping force. Further, since the gap a between the spring member 82 and the suction valve 80 is changed so as to become smaller from the support convex portion 101 toward the rivet 86, the suction valve 80 is sealed by the bending force of the spring member 82. Can increase the sex.

“Second Embodiment”
Next, the second embodiment will be described mainly based on FIG. 5 with a focus on the differences from the first embodiment. In addition, about the site | part which is common in 1st Embodiment, it represents with the same name and the same code | symbol.

  In the second embodiment, the disk 83 of the first embodiment is not provided. In the second embodiment, a valve body 21A that is partially different from the valve body 21 of the first embodiment is used. The valve body 21A is formed with a boss portion 110 that surrounds the through hole 65 and protrudes toward the lower chamber 29 in the axial direction. In the second embodiment, a suction valve 80A and a spring member 82A that are partially different from the suction valve 80 and the spring member 82 of the first embodiment are used. The suction valve 80A and the spring member 82A have an inner diameter larger than that of the first embodiment and allow the boss portion 110 to be inserted inside. The suction valve 80A and the spring member 82A are guided by the boss part 110 and are movable in the axial direction.

  In the second embodiment, a single metal holding spring 112 is provided on the opposite side of the spring member 82A from the suction valve 80A. The holding spring 112 extends from the main plate portion 113 to the outer side in the radial direction so as to approach the spring member 82A toward the outer side in the radial direction from the main plate portion 113, and is held by the boss portion 110 and the restricting disc 84. And a plurality of arm plate portions 114 that come into contact with each other. In a state where there is no pressure difference between the lower chamber 29 and the reservoir chamber 12, the plurality of arm plate portions 114 of the holding spring 112 abut against the spring member 82 </ b> A, and the support convex portion 101 of the spring member 82 </ b> A closes the flow path 73. The suction valve 80A continuously contacts the suction valve 80A. When the pressure in the lower chamber 29 falls below the pressure in the reservoir chamber 12 and the differential pressure is applied to the suction valve 80A through the flow path 73, the suction valve 80A and the spring member 82A While deforming 114, the flow path 73 is opened by moving in the axial direction away from the valve body 21A.

  According to the second embodiment, the suction valve 80A and the spring member 82A are movable in the axial direction, and the flow path 73 can be opened by deforming the lower rigidity holding spring 112. The flow path 73 can be easily opened, and the oil liquid can be replenished from the reservoir chamber 12 to the lower chamber 29 more immediately.

  In addition, also when providing a suction valve in piston 25, it is possible to apply the structure of 1st, 2nd embodiment by making the piston main body 33 of this piston 25 into a valve body.

  The embodiment described above includes a cylinder in which a working fluid is sealed, a piston that is slidably provided in the cylinder, and divides the inside of the cylinder into an upper chamber and a lower chamber, and one end is one end of the cylinder. A piston rod that protrudes from the other end and is connected to the piston, and has a flow path that is provided at the other end of the cylinder and separates the lower chamber from the reservoir chamber and allows the lower chamber and the reservoir chamber to communicate with each other. A fluid pressure shock absorber having a valve body and a disk-shaped suction valve provided on the lower chamber side of the valve body for opening and closing the flow path, the suction valve being opposite to the valve body A spring member is disposed on the outer periphery of the spring member, and a support convex portion for supporting the suction valve over the entire periphery is formed on the outer peripheral side of the spring member. Therefore, it can suppress that the sealing performance of a suction valve falls, and can suppress variation in damping force. Therefore, it is possible to generate a stable damping force. Moreover, the clearance gap between the said spring member and the said suction valve becomes small as it goes to an inner periphery from a support convex part.

DESCRIPTION OF SYMBOLS 10 Fluid pressure buffer 11 Cylinder 12 Reservoir chamber 20 Base member 21 Valve body 25 Piston 28 Upper chamber 29 Lower chamber 31 Piston rod 73 Flow path 80 Suction valve 82 Spring member 101 Support convex part

Claims (3)

A cylinder filled with a working fluid;
A piston that is slidably provided in the cylinder and divides the cylinder into an upper chamber and a lower chamber;
A piston rod having one end protruding from one end of the cylinder and the other end connected to the piston;
A valve body provided at the other end of the cylinder and having a flow path capable of separating the lower chamber and the reservoir chamber and communicating the lower chamber and the reservoir chamber;
A disk-shaped suction valve provided on the lower chamber side of the valve body for opening and closing the flow path;
A fluid pressure shock absorber comprising:
An annular flow path forming groove that forms the flow path is formed on the lower chamber side of the valve body,
A spring member is arranged on the opposite side of the suction valve from the valve body,
The spring member has an annular main plate portion and an annular outer peripheral plate portion extending radially outward, and the shaft of the valve body is located between the main plate portion and the outer peripheral plate portion rather than the main plate portion. Projecting toward the suction valve side of the direction, a support convex portion is formed that presses the suction valve over the entire circumference ;
The fluid pressure shock absorber according to claim 1, wherein the support convex portion is in contact with the flow path forming groove of the spring member in a radial direction of the spring member .   2. The fluid pressure shock absorber according to claim 1, wherein a gap between the spring member and the suction valve decreases from the support convex portion toward the inner periphery. A boss portion that protrudes toward the lower chamber side in the axial direction of the valve body is formed on the radially inner side of the valve body,
3. The fluid pressure shock absorber according to claim 1, wherein the suction valve and the spring member are guided by the boss portion and are movably provided in an axial direction of the valve body.

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