JP2017211069A - Shock absorber - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a shock absorber which enables easy tuning of damping force characteristics.SOLUTION: A shock absorber has: a valve body 71 through which a passage 118 penetrates; an annular outer sheet 93 which encloses one end opening of the passage 118; an annular disc valve 73 which is placed so that one side surface may be seated on the outer sheet 93; and an inner sheet 241 which may contact with the other side surface of the disc valve 73 and has a diameter smaller than that of the outer sheet 93. Biasing means 78 which biases the outer periphery side of the disc valve 73 toward the outer sheet 93 is provided at the other side surface side of the disc valve 73.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a shock absorber.

  There is a shock absorber using a disk valve that is simply supported on the inner and outer circumferences that opens in both the expansion side stroke and the contraction side stroke (see, for example, Patent Document 1).

JP 11-125295 A

  The above disk valve cannot easily tune the damping force characteristic.

  Therefore, an object of the present invention is to provide a shock absorber that can easily tune damping force characteristics.

  To achieve the above object, according to the present invention, a valve body in which a passage penetrates an inside thereof, an annular outer seat surrounding one end opening of the passage, and a side surface mounted on the outer seat so as to be seatable. An annular disk valve, and an inner sheet having a diameter smaller than that of the outer sheet that can come into contact with the other side surface of the disk valve. The outer side of the disk valve is connected to the other side surface of the disk valve. The urging means for urging the outer sheet is provided.

  According to the present invention, the damping force characteristic can be easily tuned.

It is sectional drawing which shows the buffer of 1st Embodiment which concerns on this invention. It is a fragmentary sectional view showing the piston of the buffer of a 1st embodiment concerning the present invention, and its circumference. It is a fragmentary sectional view which shows the damping force generation mechanism of the buffer of 1st Embodiment which concerns on this invention, and its periphery. It is a top view which shows the urging | biasing disk and disk valve of the buffer of 1st Embodiment which concern on this invention. It is a diagram which shows the damping-force characteristic of a buffer, (a) shows the example, (b) shows the case where the biasing disc of 1st Embodiment which concerns on this invention is provided, respectively. It is a fragmentary sectional view showing the piston of the buffer of a 2nd embodiment concerning the present invention, and its circumference. It is a fragmentary sectional view showing the piston and its circumference of a buffer of a 3rd embodiment concerning the present invention.

“First Embodiment”
1st Embodiment which concerns on this invention is described based on FIGS. In the following, for convenience of explanation, the upper side in the drawing is referred to as “upper” and the lower side in the drawing is referred to as “lower”.

  As shown in FIG. 1, the shock absorber 1 of the first embodiment is a so-called double cylinder type hydraulic shock absorber, and includes a cylinder 2 in which an oil liquid (not shown) as a working liquid is enclosed. The cylinder 2 has a cylindrical metal inner cylinder 3 and a bottomed cylindrical outer cylinder 4 that is concentrically provided so as to cover the inner cylinder 3 with a larger diameter than the inner cylinder 3. A reservoir chamber 6 is formed between the inner cylinder 3 and the outer cylinder 4.

  The outer cylinder 4 includes a cylindrical metal body member 11 and a metal bottom member 12 that closes a lower portion of the body member 11. A mounting eye 13 is fixed to the bottom member 12 on the outer side opposite to the body member 11.

  The shock absorber 1 includes a piston 16 slidably fitted in the inner cylinder 3 of the cylinder 2. The piston 16 provided in the inner cylinder 3 divides the inside of the inner cylinder 3 into an upper chamber 17 on one side in the axial direction of the piston 16 and a lower chamber 18 on the other side in the axial direction of the piston 16. ing. Oil liquid as working fluid is sealed in the upper chamber 17 and the lower chamber 18 in the inner cylinder 3, and oil liquid and gas as working fluid are placed in the reservoir chamber 6 between the inner cylinder 3 and the outer cylinder 4. And are enclosed.

  The shock absorber 1 includes a metal piston rod 21 having one end side disposed in the inner cylinder 3 of the cylinder 2 and connected to the piston 16, and the other end side extending to the outside of the cylinder 2. The piston 16 and the piston rod 21 move together. In the expansion stroke in which the piston rod 21 increases the amount of protrusion from the cylinder 2, the piston 16 moves to the upper chamber 17 side. In the contraction stroke in which the piston rod 21 decreases the amount of protrusion from the cylinder 2, the piston 16 moves downward. It moves to the chamber 18 side.

  A rod guide 22 is fitted to the upper end opening side of the inner cylinder 3 and the outer cylinder 4, and a seal member 23 is attached to the outer cylinder 4 on the upper side, which is the outer side of the cylinder 2, relative to the rod guide 22. Yes. Both the rod guide 22 and the seal member 23 are annular. The piston rod 21 is slidably inserted inside the rod guide 22 and the seal member 23, and extends outside the cylinder 2 via the rod guide 22 and the seal member 23. The upper chamber 17 is formed between the piston 16 in the inner cylinder 3 and the rod guide 22.

  Here, the rod guide 22 supports the piston rod 21 so as to be movable in the axial direction while restricting its radial movement, and guides the movement of the piston rod 21. The seal member 23 is in close contact with the outer cylinder 4 at the outer peripheral portion thereof, and is in sliding contact with the outer peripheral portion of the piston rod 21 that moves in the axial direction at the inner peripheral portion thereof. This prevents the high-pressure gas and oil liquid in the inner reservoir chamber 6 from leaking to the outside.

  The rod guide 22 has a step shape in which the outer peripheral portion has a larger diameter at the upper portion than the lower portion. The rod guide 22 is fitted to the inner peripheral portion at the upper end of the inner tube 3 at the lower portion of the small diameter, and the outer tube at the upper portion of the large diameter. 4 is fitted to the inner periphery of the upper part. A base valve 25 that defines a lower chamber 18 and a reservoir chamber 6 is installed on the bottom member 12 of the outer cylinder 4, and the inner peripheral portion of the lower end of the inner cylinder 3 is fitted to the base valve 25. ing. The upper end portion of the outer cylinder 4 is caulked inward in the radial direction to form a caulking portion 26, and the caulking portion 26 and the rod guide 22 sandwich the seal member 23. The lower chamber 18 is formed between the piston 16 in the inner cylinder 3 and the base valve 25.

  The piston rod 21 has a main shaft portion 31 and a mounting shaft portion 32 having a smaller diameter than the main shaft portion 31, and an end portion of the main shaft portion 31 on the mounting shaft portion 32 side is a shaft step portion 33 that extends in the direction perpendicular to the axis. ing. The attachment shaft portion 32 is disposed in the cylinder 2, and a male screw 34 is formed at the end opposite to the main shaft portion 31. The piston 16 is fastened to the mounting shaft portion 32 by a metal nut 35 screwed into the male screw 34. In other words, the piston rod 21 is fastened to the piston 16 by the nut 35.

  In the shock absorber 1, for example, a protruding portion of the piston rod 21 from the cylinder 2 is arranged at the upper part and supported by the vehicle body, and the mounting eye 13 on the cylinder 2 side is arranged at the lower part and connected to the wheel side. On the contrary, the cylinder 2 side may be supported by the vehicle body, and the piston rod 21 may be connected to the wheel side. When the wheels vibrate as the vehicle travels, the positions of the cylinder 2 and the piston rod 21 change relatively with the vibrations, but the change is suppressed by the fluid resistance of the flow path formed in the piston 16.

  As shown in FIG. 2, the piston 16 is configured by stacking a regulating member 37, a contact disk 38, a small-diameter disk 39, and a plurality of single disks in order from the axial step 33 side in the axial direction. It has a disk valve 40, a piston body 41, a disk valve 42 formed by stacking a plurality of single disks, and a small diameter disk 43 formed by stacking a plurality of single disks. The restriction member 37, the contact disk 38, the small diameter disk 39, the disk valve 40, the piston body 41, the disk valve 42, and the small diameter disk 43 are all made of metal. The piston 16 has an annular belt-shaped synthetic resin sliding contact member 44 attached to the outer peripheral surface of the piston main body 41 and in sliding contact with the inner peripheral surface of the inner cylinder 3.

  The restricting member 37 has an annular shape, and the attachment shaft portion 32 is fitted on the inner peripheral side. The regulating member 37 has an outer diameter larger than the outer diameter of the shaft step portion 33. The restricting member 37 is thinner than the contact disk 38, the small diameter disk 39, the single disk constituting the disk valve 40, the single disk constituting the disk valve 42, and the single disk constituting the small diameter disk 43. It is thick and highly rigid.

  The contact disk 38 has an annular shape, and the mounting shaft portion 32 is fitted on the inner peripheral side. The contact disk 38 has an outer diameter larger than the outer diameter of the regulating member 37. The small-diameter disk 39 has an annular shape, and the attachment shaft portion 32 is fitted on the inner peripheral side. The small diameter disk 39 has an outer diameter smaller than the outer diameter of the regulating member 37.

  In the disk valve 40, all the single disks constituting the disk valve 40 have an annular shape, and the mounting shaft portion 32 is fitted on the inner peripheral side. The disk valve 40 has a larger outer diameter toward the piston body 41 in the axial direction. The disc valve 40 has a maximum outer diameter, which is the outer diameter of the end portion on the piston body 41 side in the axial direction, larger than the outer diameter of the contact disc 38, and the end portion on the small diameter disc 39 side in the axial direction. The minimum outer diameter, which is the outer diameter, is larger than the outer diameter of the small-diameter disk 39.

  The piston main body 41 is formed in an annular shape at the center in the radial direction so that a fitting hole 50 for fitting the mounting shaft portion 32 of the piston rod 21 penetrates in the axial direction. The piston body 41 has a linear passage 51 extending in the axial direction outside the radial fitting hole 50 and an axial direction extending outside the radial fitting hole 50. And a straight passage 52 is formed. A plurality of passages 51 are formed at equal intervals in the circumferential direction of the piston body 41 (only one is shown in the drawing because of the cross-sectional view), and a plurality of passages 52 are also formed at equal intervals in the circumferential direction of the piston body 41. (The drawing shows only one place because of its cross-section). The passages 51 and the passages 52 are alternately arranged in the circumferential direction of the piston body 41.

  In addition, the piston body 41 has an annular passage 53 that forms a ring over the entire circumference of the piston body 41 so that a plurality of passages 51 communicate with each other at the end on the axial disk valve 40 side, and an axial disk valve 42 side. An annular passage 54 that forms a ring over the entire circumference of the piston body 41 is formed so as to connect the plurality of passages 52 at the end of the piston body 41.

  By forming the annular passage 53, the annular clamp seat 56 and the annular passage 53 inside the annular passage 53 in the radial direction of the piston main body 41 are provided at the end of the piston body 41 in the axial direction on the disk valve 40 side. The outer annular contact sheet 57 is formed so as to protrude in the axial direction of the piston main body 41. In other words, on the disk valve 40 side of the piston body 41, an annular contact sheet 57 and an annular clamp sheet 56 radially inward of the contact sheet 57 project in the axial direction. In the plurality of passages 52, the opening on the disk valve 40 side is located on the radially outer side than the opening on the disk valve 42 side, and is opened on the radially outer side than the contact sheet 57.

  The disk valve 40 has a maximum outer diameter, which is the outer diameter of the end portion on the piston body 41 side in the axial direction, substantially the same as the outer diameter of the end surface of the contact sheet 57 on the disk valve 40 side. Therefore, the disc valve 40 is placed so as to be seated on the clamp seat 56 and the contact seat 57. The disc valve 40 can be separated from and seated on the contact seat 57. The abutting disk 38 restricts the deformation beyond a predetermined amount when the disk valve 40 is separated from the abutting seat 57 by abutting against the abutting disk 57. The disk valve 40 is formed with a fixed orifice 58 that allows the upper chamber 17 and the annular passage 53 to communicate with each other even in a state of contact with the contact sheet 57.

  By forming the annular passage 54, the end of the piston main body 41 on the disk valve 42 side in the axial direction is more than the clamp seat 61 and the annular passage 54 inside the annular passage 54 in the radial direction of the piston main body 41. Both outer contact sheets 62 are provided so as to protrude in the axial direction of the piston body 41. In other words, on the disk valve 42 side of the piston body 41, an annular contact sheet 62 and an annular clamp sheet 61 radially inward of the contact sheet 62 project in the axial direction.

  In the disk valve 42, any single disk constituting the disk valve 42 has an annular shape, and the mounting shaft portion 32 is fitted to the inner peripheral side. The disk valve 42 has a larger outer diameter toward the piston body 41 in the axial direction. The disc valve 42 has a maximum outer diameter, which is the outer diameter of the end portion on the piston body 41 side in the axial direction, slightly larger than the outer diameter of the end surface of the contact sheet 62 on the disc valve 42 side. And it is mounted on the contact sheet 62 so as to be seated. The disc valve 42 can be separated from and seated on the contact sheet 62. The disk valve 42 is formed with a fixed orifice 63 that allows the annular passage 54 to communicate with the outer side of the disk valve 42 even when the disk valve 42 is in contact with the contact sheet 62. In the small-diameter disk 43, each of the single disks constituting the disk 43 has an annular shape, and the mounting shaft portion 32 is fitted on the inner peripheral side. The small diameter disk 43 has an outer diameter smaller than the minimum outer diameter which is the outer diameter of the end of the disk valve 42 on the small diameter disk 43 side.

  A mounting base portion 65 is formed on the outer periphery of the piston main body 41 so as to be biased toward the disk valve 40 in the axial direction, and the sliding contact member 44 is mounted on the mounting base portion 65. A fitting portion 66 having a smaller diameter than the mounting base portion 65 is formed on the outer peripheral portion of the piston main body 41 on the disk valve 42 side in the axial direction from the mounting base portion 65. The fitting portion 66 includes a cylindrical outer peripheral fitting surface 67 and an annular seal groove 68 that is recessed radially inward from the outer peripheral fitting surface 67. The fitting portion 66 is provided on the side of the clamp body 61 and the contact sheet 62 in the axial direction in the piston main body 41, and the outer peripheral fitting surface 67 is on the outer peripheral side of the radial contact sheet 62 in the piston main body 41. Is provided. The plurality of passages 51 have an opening on the side opposite to the disc valve 40 positioned on the radially outer side than the opening on the disc valve 40 side, and a mounting base portion located on the radially outer side with respect to the contact sheet 62 An opening is provided between 65 and the fitting portion 66.

  The piston 16 further includes a valve body 71, a guide disk 72 and a disk valve 73, a support disk 74 formed by laminating a plurality of single disks, and an urging force in order from the axial step 33 side in the axial direction. A disk 78 (biasing means), a contact disk 75, and a regulating member 76 are provided. The valve main body 71, the guide disk 72, the disk valve 73, the support disk 74, the urging disk 78, the contact disk 75, and the regulating member 76 are all made of metal. The restricting member 76 is thicker and has higher rigidity than the guide disk 72, the disk valve 73, and the single disk constituting the support disk 74, the biasing disk 78, and the contact disk 75, all of which are thin plates. The biasing disk 78 is thinner and less rigid than the single disk and the contact disk 75 constituting the guide disk 72, the disk valve 73, and the support disk 74.

  The piston 16 has a rubber seal member 77 interposed between the piston main body 41 and the valve main body 71.

  The valve main body 71 has a bottomed cylindrical shape having a cylindrical cylindrical portion 81 and a bottom portion 82 provided on the radially inner side of one axial end of the cylindrical portion 81. The bottom portion 82 is provided so as to expand in the direction perpendicular to the axis of the cylindrical portion 81. Between the cylinder part 81 and the bottom part 82, an R chamfer 83 is provided at the inner corner position. The R chamfer 83 has a smaller diameter toward the bottom portion 82 side, and smoothly connects the tubular portion 81 and the bottom portion 82.

  A fitting hole 85 for fitting the mounting shaft portion 32 of the piston rod 21 is formed in the valve main body 71 at the center of the bottom portion 82 which is the center in the radial direction so as to penetrate in the axial direction. In addition, a plurality of passages 86 are formed on the bottom portion 82 on the side of the tubular portion 81 in the axial direction so as to penetrate the inside of the bottom portion 82 in the axial direction outside the radial fitting hole 85 and inside the R chamfer 83. Has been. The plurality of passages 86 are formed in the bottom portion 82 at equal intervals in the circumferential direction. The plurality of passages 86 are provided with a tapered portion 87 whose diameter increases toward the cylindrical portion 81 side at the opening position on the axial cylindrical portion 81 side on the piston body 41 side, and is opposite to the axial cylindrical portion 81. The side is a constant inner diameter portion 88 having a constant inner diameter regardless of the axial position. An annular passage 91 is formed in the bottom portion 82 on the opposite side to the cylindrical portion 81 in the axial direction so as to form a ring over the entire circumference of the valve main body 71 so as to communicate the plurality of passages 86.

  By forming the annular passage 91, an annular clamp seat 92 inside the annular passage 91 in the radial direction of the valve body 71 is formed at the end of the valve body 71 opposite to the piston body 41 in the axial direction. An annular outer sheet 93 outside the annular passage 91 is formed so as to protrude in the axial direction of the valve body 71. In other words, on the valve body 71, an annular outer sheet 93 and an annular clamp sheet 92 radially inward of the outer sheet 93 protrude in the axial direction on the side opposite to the piston body 41.

  FIG. 3 is a partially enlarged view of FIG. 2 with the piston 16 and the piston rod 21 turned upside down. As shown in FIG. 3, the clamp seat 92 is a flat surface in which the seat surface 201 at the tip in the protruding direction is orthogonal to the central axis of the valve body 71. Similarly, the outer seat 93 is a flat surface in which the seat surface 202 at the front end in the protruding direction is orthogonal to the central axis of the valve body 71. Each of the sheet surface 201 and the sheet surface 202 has an annular shape in which the outer periphery and the inner periphery are concentric circles. The seat surface 202 is disposed outside the seat surface 201 in the axial direction of the valve body 71. That is, in the axial direction of the valve body 71, the outer sheet 93 has a larger protruding amount from the valve body 71 than the clamp sheet 92.

  On the valve body 71, an annular restraining projection 211 is projected in the axial direction so as to surround the outer sheet 93 on the outer peripheral side of the valve body 71 in the radial direction. The restraining protrusion 211 has a larger protruding amount from the valve body 71 than the outer seat 93 in the axial direction of the valve body 71. The restraining protrusion 211 is continuously formed over the entire circumference in the circumferential direction of the valve body 71 and has an annular shape in which the central axis coincides with the outer seat 93.

  In the valve body 71, an annular recess 212 that is recessed from the seat surface 202 of the outer sheet 93 in the axial direction of the valve body 71 is formed between the restraining projection 211 in the radial direction and the outer sheet 93. The recess 212 is also formed continuously over the entire circumference in the circumferential direction of the valve body 71 and has an annular shape whose center axis coincides with the outer seat 93 and the restraining projection 211.

  The recess 212 and the restraining protrusion 211 are connected by a tapered surface 213 having a larger diameter toward the distal end side in the protruding direction of the restraining protrusion 211. That is, the tapered surface 213 constitutes both the concave portion 212 and the restricting projection 211. The front end surface 214 on the protruding front end side of the restricting projection 211 is a flat surface orthogonal to the central axis of the valve body 71 and has an annular shape in which the outer periphery and the inner periphery are concentric circles. In the axial direction of the valve body 71, the distal end surface 214 is disposed outside the seat surface 202.

  As shown in FIG. 2, the valve main body 71 is provided with a tapered portion 95 having a diameter that decreases as the distance from the bottom portion 82 increases on the outer peripheral portion opposite to the bottom portion 82 of the cylindrical portion 81. A tapered portion 96 having a smaller diameter as the distance from the cylindrical portion 81 increases. A part of the tapered portion 96 on the small diameter side forms a constraining protrusion 211. In the valve main body 71, the bottom portion 82 abuts on and regulates a predetermined deformation or more when the disc valve 42 is separated from the contact sheet 62.

  The guide disk 72 has an annular shape, and the mounting shaft portion 32 is fitted on the inner peripheral side. In the guide disk 72, a plurality of notches 101 are formed in the outer peripheral portion at intervals in the circumferential direction. The maximum outer diameter of the guide disk 72 is larger than the outer diameter of the end face of the clamp sheet 92 on the guide disk 72 side, and smaller than the inner diameter of the end face of the outer sheet 93 on the disk valve 73 side. In the support disk 74, any single disk constituting the support disk 74 has an annular shape, and the mounting shaft portion 32 is fitted to the inner peripheral side. In the support disk 74, the outer diameter of the single disk constituting the support disk 74 is larger than the maximum outer diameter of the guide disk 72.

  As shown in FIG. 4, the urging disk 78 has a plate shape, and has a base plate portion 231 that forms an annular shape and fits the mounting shaft portion 32 on the inner peripheral side, and the circumferential direction of the base plate portion 231. As shown in FIG. 3, a plurality of leg plate portions 232 extending in an inclined manner so that the outer side in the radial direction is located on one side in the axial direction as shown in FIG. And a contact plate portion 233 extending in a radial direction of the base plate portion 231 in a direction away from the base plate portion 231 from a tip side opposite to each base plate portion of the portion 232.

  The three leg plate portions 232 are formed in an isosceles trapezoidal shape so that the width in the circumferential direction of the base plate portion 231 becomes narrower as it extends outward from the base plate portion 231 in the radial direction. The three contact plate portions 233 are also semicircular so that the width in the circumferential direction of the base plate portion 231 becomes narrower as it extends from the corresponding leg plate portion 232 outward in the radial direction of the base plate portion 231. Is formed. When the urging disc 78 is in a natural state where no external force is applied, the three contact plate portions 233 are parallel to the base plate portion 231, and the three leg plate portions 232 are inclined with respect to these. The outer diameter of the base plate portion 231 is larger than the outer diameter of the support disk 74, and the diameter of the circumscribed circle of the three contact plate portions 233 is slightly smaller than the outer diameter of the disc valve 73. Yes.

  As shown in FIG. 2, the contact disk 75 has an annular shape, and the attachment shaft portion 32 is fitted to the inner peripheral side. The contact disk 75 has an outer diameter larger than the outer diameter of the support disk 74 and is slightly smaller than the diameter of the circumscribed circle of the three contact plate portions 233 of the biasing disk 78. The restricting member 76 has an annular shape, and the mounting shaft portion 32 is fitted to the inner peripheral side, and the outer diameter is larger than the outer diameter of the support disk 74 and smaller than the outer diameter of the contact disk 75. It has become.

  The disk valve 73 has a flat plate shape when it is in a natural state where it does not deform, and elastically deforms into a taper shape when assembled to the piston 16 as shown in FIG. The disk valve 73 has an annular shape in which the outer periphery and the inner periphery are concentric circles. As shown in FIG. 3, the disc valve 73 has an inner diameter that is slightly larger than the maximum outer diameter of the guide disc 72 and smaller than the outer diameter of the support disc 74. The outer diameter of the outer seat 93 of the valve body 71 is larger than the outer diameter of the seat surface 202 and smaller than the inner diameter of the distal end surface 214 of the restraining projection 211.

  The disk valve 73 is mounted so that one side surface in the axial direction can be attached to and detached from the outer seat 93, and the other side surface on the opposite side in the axial direction is on the outer peripheral side of the support disk 74 and on the disk valve 73 side in the axial direction. The inner sheet 241 is placed so as to be able to come into contact therewith. The outer diameter of the inner seat 241 is smaller than the inner diameter of the seat surface 202 of the outer seat 93, and the disc valve 73 abuts the outer seat 93 on the outer peripheral side and the inner seat 241 on the inner peripheral side. . The urging disc 78 abuts on the outer peripheral side of the disc valve 73 at the plurality of abutting plate portions 233 while being elastically deformed. The abutting disk 75 that abuts on the high-rigidity regulating member 76 abuts against the abutting plate portion 233 of the urging disk 78 to regulate deformation beyond a predetermined level when the disk valve 73 is separated from the outer seat 93.

  When assembling the piston 16 to the piston rod 21, the piston rod 21 is vertically arranged in a posture in which the mounting shaft portion 32 is located above the main shaft portion 31 shown in FIG. 2. Then, while the mounting shaft portions 32 are inserted into the piston rods 21 respectively, the regulating member 37, the contact disk 38, the small diameter disk 39, the disk valve 40, the sliding contact member 44, and the seal member 77. The piston main body 41, the disk valve 42, the small diameter disk 43, the valve main body 71, and the guide disk 72 are stacked on the shaft step portion 33 in this order. At that time, the cylinder portion 81 of the valve main body 71 is fitted to the fitting portion 66 of the piston main body 41 in a state where the seal member 77 is previously disposed in the seal groove 68. In this state, the regulating member 37, the contact disk 38, the small diameter disk 39, the disk valve 40, the piston main body 41, the disk valve 42, the small diameter disk 43, the valve main body 71 and the guide disk 72 are connected to the piston rod 21 by the mounting shaft portion 32. However, it is restrained so as not to move in the radial direction.

  Next, the disc valve 73 is overlaid on the valve body 71 while the mounting shaft portion 32 of the piston rod 21 is inserted inside. At this time, the disc valve 73 is not deformed and is in a flat plate-like natural state. The disc valve 73 has a natural outer diameter larger than the outer diameter of the seat surface 202 of the outer seat 93, and the tapered surface 213 at the height position of the seat surface 202 in the axial direction of the valve body 71. It is equivalent to the inner diameter. In other words, the disk valve 73 has a natural outer diameter smaller than the maximum inner diameter of the tapered surface 213 and larger than the minimum inner diameter of the tapered surface 213. The disc valve 73 has an inner diameter in a natural state slightly larger than the maximum outer diameter of the guide disc 72.

  The distance between the sheet surface 201 of the clamp sheet 92 and the sheet surface 202 of the outer sheet 93 in the axial direction of the valve body 71 is equal to the thickness of the guide disk 72. Further, the distance between the seat surface 202 of the outer sheet 93 and the front end surface 214 of the restraining projection 211 in the axial direction of the valve body 71 is ½ or more of the thickness of the disk valve 73 in the natural state.

  As described above, the outer diameter of the disk valve 73 in the natural state is equal to the inner diameter of the tapered surface 213 at the height position of the seat surface 202 in the axial direction of the valve body 71. For this reason, when the disc valve 73 is placed on the seat surface 202 of the outer seat 93, it fits inside the restraining protrusion 211. In this state, the outer periphery of the disc valve 73 is restrained by the restraining protrusion 211 and the radial movement with respect to the valve body 71 is restricted. That is, the restraining protrusion 211 restrains the outer periphery of the disk valve 73 and positions it in the radial direction. The disc valve 73 is restrained so as not to move in the radial direction even with respect to the piston rod 21 in which the radial movement with respect to the valve body 71 is restricted, and the guide disc 72 in which the radial movement with respect to the piston rod 21 is restricted. Also, it is restrained so as not to move in the radial direction.

  Here, since the thickness of the guide disk 72 is equal to the distance between the seat surface 201 of the clamp seat 92 and the seat surface 202 of the outer seat 93 in the axial direction of the valve body 71, the disc valve 73 is placed on the seat surface. The guide disc 72 is basically not fitted to the inner peripheral side of the disc valve 73 only by being overlaid on the 202, and even if fitted, the guide disc 72 has a very small length. For this reason, there is basically no restriction on the radial movement of the disc valve 73 by the guide disc 72 fitted to the piston rod 21, and if any, the restraint force is insufficient. Therefore, the disk valve 73 is not restrained in the radial direction of the valve body 71 without the restraining protrusion 211, but is restrained in the radial direction of the valve body 71 by the presence of the restraining protrusion 211.

  As shown in FIG. 3, the support disc 74, the biasing disc 78, the contact disc 75, and the regulation disc shown in FIG. The member 76 is overlapped in this order. At this time, the urging disc 78 is superimposed on the support disc 74 in the base plate portion 231, and the plurality of leg plate portions 232 extend from the base plate portion 231 so as to approach the disc valve 73 in the axial direction of the base plate portion 231. . The support disk 74, the biasing disk 78, the contact disk 75, and the regulating member 76 are restrained by the mounting shaft portion 32 by restricting the movement of the piston rod 21 in the radial direction.

  With the components arranged in this way, the nut 35 is screwed onto the male screw 34 of the mounting shaft portion 32 that protrudes beyond the regulating member 76. Thereby, as shown in FIG. 2, the regulating member 37, the contact disk 38, the small diameter disk 39, the disk valve 40, the piston body 41, the disk valve 42, the small diameter disk 43, the valve body 71, The guide disk 72, the support disk 74, the biasing disk 78, the contact disk 75, and the regulating member 76 are respectively sandwiched between the shaft step portion 33 and the nut 35 of the piston rod 21 on the inner peripheral side or all of them. Are clamped in the axial direction, and an axial force is applied to them. At that time, the disc valve 73 is not clamped in the axial direction. The nut 35 is a general-purpose hex nut.

  Here, before clamping the piston 16 with the nut 35 and the piston rod 21, the disc valve 73 in which the guide disc 72 has not been inserted inside has the inner peripheral side on the disc valve 73 side of the support disc 74 and the outer periphery after clamping. The inner side sheet 241 comes into contact with the inner side sheet 241 and is pressed by the inner side sheet 241. Since the axial movement on the outer peripheral side is restricted by the outer side sheet 93, it is elastically deformed in a tapered shape, and the guide disk is placed inside it. 72 enters. Therefore, in the state where the axial force is applied to the piston 16 as described above, the disc valve 73 is in a state where the inner peripheral side is restrained by the guide disc 72 on the inner side and the movement in the radial direction is restricted.

  Further, with the axial force applied to the piston 16, the urging disk 78 is clamped in the axial direction at the base plate portion 231 on the inner peripheral side, and the axial movement with respect to the valve body 71 is restricted. In this state, in the urging disc 78, all the contact plate portions 233 are in contact with the outer peripheral side of the surface of the disc valve 73 on the inner seat 241 side in the axial direction, and all the leg plate portions 232 are elastically deformed. . As a result, the urging disc 78 abuts on the outer peripheral side of the surface of the disc valve 73 on the inner seat 241 side in the axial direction and generates a preload that urges the outer peripheral side toward the outer seat 93.

  In the piston 16 attached to the piston rod 21 in this way, the minimum axial distance between the inner seat 241 and the outer seat 93 of the support disc 74 is shorter than the axial thickness of the disc valve 73. Yes. For this reason, the disc valve 73 contacts the inner sheet 241 and the outer sheet 93 while being deformed as described above. Thus, when there is no pressure difference between the annular passage 91 side and the lower chamber 18 side, the disk valve 73 abuts the inner seat 241 over the entire circumference with a set load caused by its own elastic deformation, and the outer circumference side It abuts against the outer sheet 93 over the entire circumference with a set load generated by its own elastic deformation and the elastic deformation of the biasing disk 78. Thereby, the communication between the annular passage 91 and the lower chamber 18 is blocked.

  From this state, when the pressure in the annular passage 91 exceeds the set load and becomes higher than the pressure in the lower chamber 18, the disk valve 73 bends with the inner sheet 241 of the support disk 74 as a fulcrum, and the outer peripheral side elastically biases the biasing disk 78. The valve is opened away from the outer seat 93 while being deformed, and the annular passage 91 and the lower chamber 18 are communicated. In this way, the disc valve 73 receives the pressure of the oil liquid in the annular passage 91 and opens to generate a damping force. At that time, the disc valve 73 is a guide disc in which a plurality of notches 101 are intermittently formed in the circumferential direction while the inner circumferential side is in contact with the inner sheet 241 of the support disc 74 over the entire circumference. It moves to the direction away from the support disk 74, being guided by the outer periphery of 72 and suppressing radial movement.

  As described above, the disk valve 73 has a simple support structure in which the inner peripheral side is supported by the support disk 74 only on one side without being clamped from both sides.

  As shown in FIG. 2, the piston 16 attached to the piston rod 21 includes a fitting portion 66 having a cylindrical outer peripheral fitting surface 67 on the outer peripheral side of the contact sheet 62 of the piston main body 41, and a valve. A cylindrical portion 81 having a cylindrical inner peripheral fitting surface 107 of the main body 71 is fitted through a seal member 77. At this time, the outer peripheral fitting surface 67 of the fitting portion 66 and the inner peripheral fitting surface 107 of the cylindrical portion 81 are opposed to each other in the radial direction with the axial position overlapped, and the seal groove 68 of the fitting portion 66 is The inner peripheral fitting surface 107 of the cylindrical portion 81 crosses the entire length in the axial direction in the axial direction.

  Here, the inner diameter of the inner peripheral fitting surface 107 of the cylindrical portion 81 is larger than the outer diameter of the outer peripheral fitting surface 67 of the fitting portion 66, so that there is a gap between the cylindrical portion 81 and the fitting portion 66 in the radial direction. Can be fitted. Further, the inner diameter of the inner peripheral fitting surface 107 is smaller than the outer diameter of the seal member 77 disposed in the seal groove 68 before being fitted to the cylindrical portion 81, and thus is disposed in the seal groove 68. The seal member 77 is fitted into the cylindrical portion 81 with the outer diameter reduced. Thereby, the fitting part 66 and the cylinder part 81 are liquid-tightly fitted via the seal member 77. As a result, the internal intermediate passage 108 between the piston main body 41 and the valve main body 71 communicates with the lower chamber 18 through a gap for fitting between the fitting portion 66 and the cylindrical portion 81. regulate.

  Further, the piston 16 attached to the piston rod 21 has a cylindrical portion 81 of the valve main body 71 that is spaced apart from the mounting base portion 65 of the piston main body 41 in the axial direction, and a tapered portion 95 of the cylindrical portion 81 is It faces the direction of the plurality of passages 51.

  The plurality of passages 51 of the piston main body 41 are opened such that the upper chamber 17 side in the axial direction of the piston main body 41 is radially inward and the lower chamber 18 side in the axial direction is radially outward. An annular passage 53 is formed so as to connect the upper chamber 17 side of these passages 51. Damping force is generated by the clamp sheet 56 and the contact sheet 57 on both sides in the radial direction of the annular passage 53 and the disc valve 40 mounted on the clamp sheet 56 and the contact sheet 57 so as to close the annular passage 53. A mechanism 111 is configured. The damping force generation mechanism 111 is disposed on the upper chamber 17 side that is one end side in the axial direction of the piston main body 41 and is attached to the piston rod 21.

  The damping force generation mechanism 111 maintains a closed state with respect to the flow of oil from the upper chamber 17 to the lower chamber 18 via the annular passage 53 and the plurality of passages 51, while the plurality of passages 51 from the lower chamber 18. And the flow of the oil liquid to the upper chamber 17 side through the annular passage 53, and therefore, the plurality of passages 51 and the annular passage 53 are used when the piston rod 21 and the piston 16 move to the contraction side. It is a contraction-side passage through which the oil passes. That is, the plurality of passages 51 and the annular passage 53 serve as a contraction-side passage 117 (passage) through which the oil liquid flows from the lower chamber 18 toward the upper chamber 17 by sliding of the piston 16 in the contraction stroke. The compression side passage 117 penetrates the inside of the piston main body 41 in the axial direction. The damping force generation mechanism 111 provided for the contraction side passage 117 is a contraction side damping force generation mechanism that generates a damping force by suppressing the flow of oil in the contraction side passage 117.

  The plurality of passages 52 of the piston main body 41 are opened such that the upper chamber 17 side in the axial direction of the piston main body 41 is radially outward, and the intermediate passage 108 side in the axial direction is radially inner. An annular passage 54 is formed so as to connect the intermediate passage 108 side of these passages 52. The plurality of passages 86 of the valve body 71 are opened in the intermediate passage 108, and the annular passage 91 connecting the plurality of passages 86 of the valve body 71 is disposed on the lower chamber 18 side.

  A damping valve 113 includes a clamp sheet 61 and a contact sheet 62 on both radial sides of the annular passage 54, and a disc valve 42 mounted on the clamp sheet 61 and the contact sheet 62 so as to close the annular passage 54. The piston main body 41 including the clamp sheet 61 and the contact sheet 62 is a main body portion of the damping valve 113. The damping valve 113 is disposed on the intermediate passage 108 side which is the other end side in the axial direction of the piston body 41 and is attached to the piston rod 21.

  An outer seat 93 radially outside the annular passage 91, a disc valve 73 slidably mounted on the outer seat 93 so as to close the annular passage 91, and a disc valve 73 seated so as to close the annular passage 91. The supporting disk 74 to be urged and the urging disk 78 for urging the disk valve 73 constitute the damping valve 114, and the valve main body 71 including the outer seat 93 is a main body portion of the damping valve 114. The damping valve 114 is disposed on the lower chamber 18 side opposite to the piston main body 41 in the axial direction of the valve main body 71 and is attached to the piston rod 21.

  The damping valve 113 and the damping valve 114 constitute a damping force generation mechanism 115.

  The damping valve 113 of the damping force generating mechanism 115 maintains a closed state with respect to the flow of the oil liquid from the intermediate passage 108 to the upper chamber 17 side via the annular passage 54 and the plurality of passages 52, while from the upper chamber 17. It opens with respect to the flow of the oil to the intermediate passage 108 side via the plurality of passages 52 and the annular passage 54. The damping valve 114 opens with respect to the flow of oil from the intermediate passage 108 to the lower chamber 18 via the plurality of passages 86 and the annular passage 91. Therefore, the plurality of passages 52, the annular passage 54, the intermediate passage 108, the plurality of passages 86, and the annular passage 91 become an extension side passage through which the oil liquid passes when the piston rod 21 and the piston 16 move to the extension side. ing. That is, in the plurality of passages 52, the annular passage 54, the intermediate passage 108, the plurality of passages 86, and the annular passage 91, the oil liquid flows out from the upper chamber 17 toward the lower chamber 18 by the sliding of the piston 16 in the extension stroke. It is an extension side passage 118 (passage). The extension side passage 118 passes through the inside of the piston main body 41 and the valve main body 71 in the axial direction. An annular outer seat 93 of the valve body 71 surrounds one end opening of the extension side passage 118. The damping force generation mechanism 115 provided for the extension side passage 118 is an extension side damping force generation mechanism that generates a damping force by suppressing the flow of the oil liquid in the extension side passage 118.

  The plurality of contraction-side passages 117 and the extension-side passages 118 are all passages through which oil, which is a working fluid, flows by sliding within the inner cylinder 3 of the piston 16, and these contraction-side passages 117 and extension-side passages 118. A damping force generation mechanism 115 that suppresses the flow of the oil liquid in the extension side passage 118 and generates a damping force is provided in the extension side passage 118 that is a part of the extension side passage 118. A plurality of passages 51 and an annular passage 53 that are part of the extension side passage 118 are formed in the piston main body 41 constituting the damping force generation mechanisms 111 and 115 so as to penetrate the inside in the axial direction. The valve body 71 constituting the mechanism 115 is formed with a plurality of passages 86 and an annular passage 91 which are a part of the extension side passage 118 so as to penetrate the inside in the axial direction. A damping valve 113 and a damping valve 114 are provided in series in the extension side passage 118 through which the oil in the upper chamber 17 flows toward the lower chamber 18.

  As shown in FIG. 1, the above-described base valve 25 is provided between the bottom member 12 of the outer cylinder 4 and the inner cylinder 3. The base valve 25 includes a base valve member 131 that partitions the lower chamber 18 and the reservoir chamber 6, a damping valve 132 provided on the lower side of the base valve member 131, that is, the reservoir chamber 6 side, and an upper side of the base valve member 131. That is, it has a suction valve 133 provided on the lower chamber 18 side and a mounting pin 134 for attaching the damping valve 132 and the suction valve 133 to the base valve member 131.

  The base valve member 131 has an annular shape, and a mounting pin 134 is fitted on the inner peripheral side. The base valve member 131 includes a plurality of passages 135 through which oil is circulated between the lower chamber 18 and the reservoir chamber 6 and between the lower chamber 18 and the reservoir chamber 6 outside the passage 135 in the radial direction. And a plurality of passages 136 through which the oil liquid is circulated. The damping valve 132 on the reservoir chamber 6 side allows the flow of oil from the lower chamber 18 to the reservoir chamber 6 through the passage 135, while allowing the flow of oil from the reservoir chamber 6 to the lower chamber 18 through the passage 135. Suppress. The suction valve 133 allows the flow of oil from the reservoir chamber 6 to the lower chamber 18 via the passage 136, while suppressing the flow of oil from the lower chamber 18 to the reservoir chamber 6 through the passage 136.

  The damping valve 132 opens in the contraction stroke of the shock absorber 1 to flow the oil from the lower chamber 18 to the reservoir chamber 6 and generate a damping force. The suction valve 133 is opened during the expansion stroke of the shock absorber 1 to flow oil from the reservoir chamber 6 into the lower chamber 18. The suction valve 133 allows the liquid to flow from the reservoir chamber 6 to the lower chamber 18 without substantially generating a damping force so as to compensate for the shortage of the liquid mainly caused by the extension of the piston rod 21 from the inner cylinder 3. Fulfills the function.

  In the shock absorber 1 of the first embodiment, in the expansion stroke, the pressure of the upper chamber 17 is increased and the pressure of the lower chamber 18 is decreased due to the movement of the piston 16, and the oil in the upper chamber 17 passes through the expansion side passage 118. Through the lower chamber 18 side. When the piston speed, which is the moving speed of the piston 16, is extremely low, the oil in the upper chamber 17 passes through the plurality of passages 52 constituting the extension side passage 118 and the annular passage 54 to the disk valve 42 constituting the damping valve 113. While being in contact with the contact sheet 62, it flows through the fixed orifice 63 formed in the disc valve 42, and flows through the intermediate passage 108, the plurality of passages 86, and the annular passage 91 constituting the expansion side passage 118, and is attenuated. The disc valve 73 constituting the valve 114 flows into the lower chamber 18 through a gap between the disc valve 73 and the outer seat 93 while being separated from the outer seat 93. As a result, the disc valve 73 and the outer seat 93 of the damping valve 114 suppress the flow of the oil liquid in the extension side passage 118 and generate a damping force of the valve characteristic. At this time, the disk valve 73 is bent with the inner sheet 241 on the outer peripheral side of the support disk 74 as a fulcrum, and the outer peripheral side is deformed against its own spring force and the spring force of the biasing disk 78 and is separated from the outer sheet 93. At that time, the inner peripheral side is in contact with the inner sheet 241 of the support disk 74 over the entire periphery, and the inner peripheral edge is guided to the outer peripheral part of the guide disk 72, and the radial movement is suppressed, while the support disk is suppressed. Move away from 74.

  Further, when the piston speed becomes higher than the above, the oil liquid in the upper chamber 17 causes the disc valve 42 constituting the damping valve 113 to be separated from the contact sheet 62 while separating the disc valve 42 from the plurality of passages 52 and the annular passage 54. The disc valve 73 constituting the damping valve 114 is separated from the outer seat 93 via the intermediate passage 108, the plurality of passages 86 and the annular passage 91. Then, it flows into the lower chamber 18 through a gap between the disc valve 73 and the outer seat 93. As a result, the disc valve 42 and the contact seat 62 of the damping valve 113 and the disc valve 73 and the outer seat 93 of the damping valve 114 suppress the flow of the oil liquid in the expansion side passage 118 and generate a damping force of the valve characteristics. Let

  In the contraction stroke, the pressure of the lower chamber 18 increases and the pressure of the upper chamber 17 decreases due to the movement of the piston 16, and the oil in the lower chamber 18 flows to the upper chamber 17 side via the contraction side passage 117. When the piston speed is low, the oil in the lower chamber 18 is transferred from the contraction side passage 117 to the disc valve 40 while the disc valve 40 constituting the damping force generation mechanism 111 is in contact with the contact seat 57. The fixed orifice 58 flows through the formed fixed orifice 58 to the upper chamber 17 side, and the fixed orifice 58 of the damping force generation mechanism 111 suppresses the flow of the oil liquid in the contraction side passage 117 and generates a damping force having an orifice characteristic. Further, when the piston speed is increased, the oil introduced from the lower chamber 18 into the compression side passage 117 flows into the upper chamber 17 through the space between the disc valve 40 and the contact seat 57 while opening the disc valve 40, The disc valve 40 and the contact sheet 57 of the damping force generation mechanism 111 suppress the flow of the oil liquid in the contraction side passage 117 and generate the damping force of the valve characteristic.

  Patent Document 1 described above describes a shock absorber using a disk valve that is simply supported on the inner and outer circumferences that opens in both the expansion side stroke and the contraction side stroke. This disc valve cannot easily tune the damping force characteristic.

  On the other hand, the shock absorber 1 of the first embodiment is provided with a biasing disc 78 that biases the outer peripheral side of the disc valve 73 toward the outer seat 93 on the inner seat 241 side of the disc valve 73. Therefore, the damping force can be made harder than in the case where the urging disk 78 is not provided. Moreover, the damping force characteristic can be further changed by changing the biasing disk 78 to one having a different rigidity and a different spring characteristic. Therefore, the damping force characteristic can be easily tuned. For example, when the same disk valve 73 is used for the expansion side and the contraction side, if the urging disk 78 is not provided, the pressure expansion ratio is the same as shown in FIG. By providing the urging disk 78 only in the disk valve 73, the expansion ratio can be tuned so that the expansion side damping force and the compression side damping force are hard as shown in FIG. 5B (A '). > A = B).

  Further, since the plate-shaped biasing disk 78 whose inner peripheral side is clamped is used as a member for biasing the outer peripheral side of the disk valve 73 toward the outer seat 93, the biasing disk 78 suppresses an increase in cost. The disc valve 73 can be biased with a stable spring force.

  Here, in the first embodiment, conversely to the above, an annular seal groove that is recessed radially outward from the inner peripheral fitting surface 107 is formed in the cylindrical portion 81 of the valve body 71, and a seal member is formed in the seal groove. And a fitting portion 66 without a seal groove of the piston main body 41 may be fitted thereto.

“Second Embodiment”
Next, the second embodiment will be described mainly based on FIG. 6 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.

  As shown in FIG. 6, in the second embodiment, the piston 16A is partially different from the piston 16 of the first embodiment. The piston 16 </ b> A has a piston main body 41 </ b> A and a piston main body 41 </ b> B, both of which are substantially divided into two parts of the piston main body 41 of the first embodiment. That is, the piston 16A has a piston body 41A, a piston body 41B, and a valve body 71 similar to that of the first embodiment.

  The piston 16A has the same regulating member 37, contact disk 38, small-diameter disk 39 and disk valve 40 as in the first embodiment. The piston body 41A is superimposed on the disk valve 40, and the piston body 41A A piston main body 41 </ b> B is superimposed on the side opposite to the disc valve 40.

  The piston main body 41A is formed in an annular shape at the center in the radial direction so that a fitting hole 50A for fitting the mounting shaft portion 32 of the piston rod 21 penetrates in the axial direction. The piston main body 41A has a bent passage 51A extending in the axial direction outside the radial fitting hole 50A, and extends in the axial direction outside the radial fitting hole 50A. A bent-shaped passage 52A is formed. In FIG. 6, only one location is shown because of the cross section, but the passage 51A and the passage 52A are both formed in the piston body 41A in the circumferential direction and are alternately arranged in the circumferential direction of the piston body 41A. Has been.

  Further, the piston body 41A has an annular passage 53 similar to that of the first embodiment in which a plurality of passages 51A are communicated with an end on the disk valve 40 side in the axial direction, a radially inner clamp sheet 56, and an annular shape. A contact sheet 57 radially outside the passage 53 is formed. In the plurality of passages 52A, the opening on the disk valve 40 side is located on the radially outer side than the opening on the side opposite to the disk valve 40, and is opened on the radially outer side than the contact sheet 57. .

  The piston main body 41A is formed with an annular passage 54A that forms a ring over the entire circumference of the piston main body 41A so as to connect the plurality of passages 52A at the end opposite to the axial disk valve 40. By forming the annular passage 54A, an inner contact portion 61A on the inner side of the annular passage 54A in the radial direction of the piston main body 41A is formed at the end of the piston main body 41A opposite to the disk valve 40 in the axial direction. Both outer contact portions 62A outside the annular passage 54A are provided so as to protrude in the axial direction of the piston main body 41A. In the plurality of passages 51A, the opening on the side opposite to the disk valve 40 is located on the radially outer side than the opening on the disk valve 40 side, and is opened on the radially outer side than the outer contact part 62A. Yes.

  The piston main body 41A is formed by sintering and has the same shape on both sides with respect to the center in the axial direction, so there is no distinction between the front and back sides. That is, it can be attached to the piston rod 21 in any axial direction.

  The piston main body 41B is formed in an annular shape at the center in the radial direction so that a fitting hole 50B for fitting the mounting shaft portion 32 of the piston rod 21 penetrates in the axial direction. The piston main body 41B is formed with a plurality of passages 51B extending in the axial direction outside the radial fitting holes 50B at equal intervals in the circumferential direction.

  The piston main body 41B is formed with an annular passage 53B that forms a ring over the entire circumference of the piston main body 41B so as to connect the plurality of passages 51B at the end of the piston main body 41A in the axial direction. By forming the annular passage 53B, the inner abutting portion 56B and the annular passage 53B on the inner side of the annular passage 53B in the radial direction of the piston main body 41B are disposed at the end of the piston body 41B on the piston body 41A side in the axial direction. An outer abutting portion 57B is provided on the outer side.

  Further, the piston body 41B has an annular passage 54 similar to that of the first embodiment in which a plurality of passages 51B are communicated with an end portion opposite to the axial piston body 41A, and a radially inner clamp sheet 61. And an abutting sheet 62 on the radially outer side of the annular passage 54 is formed.

  The piston main body 41A is formed with a mounting base portion 65 similar to that of the first embodiment in which the sliding contact member 44 is mounted on the outer peripheral portion thereof, and the piston main body 41B has an outer peripheral fitting on the outer peripheral portion thereof. A fitting portion 66 similar to that of the first embodiment having the surface 67 and a seal groove 68 that is recessed radially inward from the outer peripheral fitting surface 67 is formed. As for the fitting part 66, the outer periphery fitting surface 67 is provided in the outer peripheral side rather than the contact sheet 62 in the radial direction of piston main body 41B. A seal member 77 similar to that of the first embodiment is disposed in the seal groove 68 of the fitting portion 66.

  The piston 16A has the same disc valve 42, small diameter disc 43, valve main body 71, guide disc 72, disc valve 73, support disc 74, biasing disc 78, contact disc 75, and restricting member 76 as in the first embodiment. have.

  When the piston 16 </ b> A is assembled to the piston rod 21, the regulating member 37, the contact disk 38, the small diameter disk 39, and the disk valve 40 are inserted into the piston rod 21 with the attachment shaft portions 32 inserted into the piston rod 21. The piston main body 41A provided with the sliding contact member 44, the piston main body 41B provided with the seal member 77, the disk valve 42, the small diameter disk 43, the valve main body 71, and the guide disk 72 in this order. The shaft step 33 is overlaid. At that time, the piston main body 41A and the piston main body 41B abut the inner abutting portion 61A and the inner abutting portion 56B over the entire circumference, and contact the outer abutting portion 62A and the outer abutting portion 57B over the entire circumference. Will be in contact. In this state, the annular passage 54A and the annular passage 53B communicate with each other. In this state, the cylinder portion 81 of the valve main body 71 is fitted to the fitting portion 66 of the piston main body 41B in a state where the seal member 77 is previously disposed in the seal groove 68.

  In addition, the disc valve 73 is overlaid on the outer sheet 93 of the valve body 71 with the mounting shaft portion 32 inserted inward. Further, the support disk 74, the biasing disk 78, the contact disk 75, and the regulating member 76 are stacked on the guide disk 72 and the disk valve 73 in this order with the mounting shaft portion 32 inserted inside each of them. .

  With the components arranged in this manner, the nut 35 is screwed onto the male screw 34 of the mounting shaft portion 32 that protrudes beyond the regulating member 76. Accordingly, the regulating member 37, the contact disk 38, the small diameter disk 39, the disk valve 40, the piston body 41A provided with the sliding contact member 44, the piston body 41B provided with the seal member 77, the disk The valve 42, the small-diameter disk 43, the valve main body 71, the guide disk 72, the support disk 74, the biasing disk 78, the abutting disk 75, and the regulating member 76 are respectively pistons on the inner peripheral side. It is clamped in the axial direction by being sandwiched between the shaft step portion 33 and the nut 35 of the rod 21. At this time, the disc valve 73 is not clamped in the axial direction, but abuts against the inner sheet 241 of the support disc 74 and is elastically deformed by being pressed by the support disc 74, and the guide disc 72 is fitted inside thereof. Combine.

  By being clamped in the axial direction in this way, the piston main body 41A and the piston main body 41B have the inner contact portion 61A and the inner contact portion 56B in close contact with each other without any gap, and the outer contact portion 62A and the outer contact portion 62B. The contact portion 57B is in close contact with the entire circumference without any gap. In other words, the space between the inner contact portion 61A and the inner contact portion 56B is sealed over the entire periphery, and the space between the outer contact portion 62A and the outer contact portion 57B is sealed over the entire periphery. That is, the leakage of the oil from the annular passages 54A and 53B of the piston main body 41A and the piston main body 41B is restricted.

  In the piston 16 </ b> A attached to the piston rod 21 in this way, the fitting portion 66 and the cylindrical portion 81 are fluid-tightly fitted via the seal member 77, and the fitting portion 66 and the cylindrical portion 81 are fitted. The intermediate passage 108 between the piston main body 41 </ b> B and the valve main body 71 is restricted from communicating with the lower chamber 18 through the clearance. Moreover, the taper part 95 of the cylinder part 81 of the valve body 71 faces the direction of the plurality of passages 51A of the piston body 41A.

  The plurality of passages 51A and the annular passage 53 of the piston main body 41A constitute a contraction-side passage 117A through which the oil liquid passes when the piston rod 21 and the piston 16 move to the contraction side. A damping force is applied to the contraction-side passage 117A. A generation mechanism 111 is provided.

  When the plurality of passages 52A, the annular passage 54A, the annular passage 53B, the plurality of passages 51B, the annular passage 54, the intermediate passage 108, the plurality of passages 86, and the annular passage 91 move to the expansion side. It is an extension side passage 118A (passage) through which the oil liquid passes, and a damping force generation mechanism 115 is provided in the extension side passage 118A.

  The piston body 41A is formed with a plurality of passages 52A and an annular passage 54A that are part of the extension side passage 118A in the axial direction, and the piston body 41B has one of the extension side passages 118A. An annular passage 53B, a plurality of passages 51B, and an annular passage 54, which are parts, are formed so as to penetrate the inside thereof in the axial direction.

  Also in the second embodiment, in the extension stroke, when the piston speed is extremely low, the oil liquid in the upper chamber 17 causes the plurality of passages 52A, the annular passages 54A, the annular passages 53B, and the plurality of passages 51B constituting the extension side passage 118A. The annular passage 54 and the intermediate passage 108 constituting the fixed orifice 63 and the extension side passage 118A formed in the disc valve 42 while the disc valve 42 constituting the damping valve 113 is kept in contact with the contact seat 62. The disc valve 73 that flows through the plurality of passages 86 and the annular passage 91 and separates from the outer seat 93 while keeping the disc valve 73 constituting the damping valve 114 away from the outer seat 93 against its own spring force and the spring force of the biasing disc 78. It flows into the lower chamber 18 through a gap with the sheet 93. As a result, the disc valve 73 and the outer seat 93 of the damping valve 114 suppress the flow of the oil liquid in the extension side passage 118A and generate a damping force of the valve characteristic.

  Further, when the piston speed becomes faster than the above, the fluid in the upper chamber 17 causes the disk valve constituting the damping valve 113 from the plurality of passages 52A, the annular passage 54A, the annular passage 53B, the plurality of passages 51B, and the annular passage 54. 42 is separated from the contact sheet 62 and flows into the intermediate passage 108 through the gap between the disc valve 42 and the contact sheet 62, and the damping valve 114 is constituted by the intermediate passage 108, the plurality of passages 86 and the annular passage 91. The disc valve 73 to flow flows into the lower chamber 18 through a gap between the disc valve 73 and the outer seat 93 while being separated from the outer seat 93 against the spring force of the own disc and the biasing disc 78. As a result, the disc valve 42 and the abutting seat 62 of the damping valve 113 and the disc valve 73 and the outer seat 93 of the damping valve 114 suppress the flow of the oil liquid in the extension side passage 118A to generate a damping force of the valve characteristics.

  In the contraction stroke, the oil in the lower chamber 18 flows to the upper chamber 17 side through the contraction side passage 117A. When the piston speed is low, the oil in the lower chamber 18 is formed in the disc valve 40 while the disc valve 40 constituting the damping force generation mechanism 111 is in contact with the contact seat 57 from the contraction side passage 117A. The fixed orifice 58 of the damping force generation mechanism 111 suppresses the flow of the oil liquid in the contraction side passage 117A and generates the damping force of the orifice characteristic. Further, when the piston speed is increased, the oil introduced from the lower chamber 18 into the contraction side passage 117A flows into the upper chamber 17 through the space between the disc valve 40 and the contact seat 57 while opening the disc valve 40, The disc valve 40 and the contact sheet 57 of the damping force generation mechanism 111 suppress the flow of the oil liquid in the contraction side passage 117A and generate a damping force of the valve characteristic.

  In the second embodiment, the same effects as those of the first embodiment can be obtained. In addition, one piston main body 41B is simply replaced with another piston main body 41B having a different cross-sectional area of the passage 51B. Thus, the damping force characteristic by the damping valve 114 can be changed, and the piston body 41A can be shared when the damping force characteristic is changed.

“Third Embodiment”
Next, the third embodiment will be described mainly on the basis of FIG. 7, focusing on the differences from the first and second embodiments. In addition, about the site | part which is common in 1st, 2nd embodiment, it represents with the same name and the same code | symbol.

  As shown in FIG. 7, the piston 16C of the third embodiment has a valve body 71C. A fitting hole 85C for fitting the mounting shaft portion 32 of the piston rod 21 is formed in the valve body 71C in the radial direction so as to penetrate in the axial direction. The valve main body 71 </ b> C is fitted to the mounting shaft portion 32 of the piston rod 21 and is in contact with the shaft step portion 33. The valve body 71C is formed with a plurality of passages 86C penetrating in the axial direction on the radially outer side than the fitting hole 85C. The plurality of passages 86C are formed in the valve body 71C at equal intervals in the circumferential direction. In the valve main body 71C, an annular passage 91C is formed on the opposite side of the shaft step portion 33 in the axial direction so as to form a ring over the entire circumference of the valve main body 71C so as to communicate the plurality of passages 86C.

  By forming the annular passage 91C, a clamp sheet 92 and an outer sheet 93 similar to those of the first embodiment are formed at the end of the valve body 71C opposite to the axial step 33 in the axial direction. Further, the valve main body 71 </ b> C is formed with a restraining projection 211 similar to that of the first embodiment on the outer peripheral side of the outer seat 93, and between the restraining projection 211 and the outer seat 93, similarly to the first embodiment. The recess 212 is formed.

  The piston 16C is provided with a guide disk 72 similar to that of the first embodiment in contact with the clamp sheet 92 of the valve body 71C, and a support disk 74 similar to that of the first embodiment is in contact with the guide disk 72. Is provided. The piston 16C is provided with an urging disk 78 similar to that of the first embodiment in contact with the support disk 74 at the base plate portion 231, and the urging disk 75 similar to that of the first embodiment is urged. It is provided in contact with the base plate portion 231 of the disk 78. In addition, a disk valve 73 similar to that of the first embodiment is disposed on the piston 16C between the support disk 74 and the valve body 71C on the radially outer side of the guide disk 72.

  Also in the third embodiment, the disk valve 73 has a flat plate shape when in a natural state where it does not deform, and elastically deforms in a tapered shape in a state assembled to the piston 16C as shown in FIG. Further, the biasing disc 78 is clamped in the axial direction at the base plate portion 231 on the inner peripheral side in a state assembled to the piston 16C, and all the leg plate portions 232 are elastically deformed, so that all the contact plate portions 233 are fixed. Comes into contact with the outer peripheral side of the disk valve 73. As a result, the urging disc 78 abuts on the outer peripheral side of the surface on the inner seat 241 side in the axial direction of the disc valve 73 and urges the outer peripheral side toward the outer seat 93. Also in the third embodiment, the disk valve 73 has a simple support structure in which the inner peripheral side is supported by the support disk 74 only on one side without being clamped from both sides.

  The piston 16C includes a small-diameter disk 300 that abuts against the abutting disk 75, a passage-forming member 302 that is in contact with the small-diameter disk 300 and has a passage groove 301 that extends in the radial direction on the opposite side of the small-diameter disk 300, A case member 306 which has a bottomed cylindrical shape having a cylindrical portion 305 and abuts against the passage forming member 302 at the bottom portion 304 and fits to the valve main body 71C at the cylindrical portion 305; And a seal member 308 for sealing between the two. A passage hole 310 communicating with the passage groove 301 of the passage forming member 302 is formed in the mounting shaft portion 32 of the piston rod 21. Through the passage hole 310 and the passage groove 301, the chamber 311 between the valve main body 71 </ b> C and the case member 306 always communicates with the lower chamber 18.

  On the bottom 304 of the case member 306, the same restricting member 37, contact disk 38, small-diameter disk 39 and disk valve 40 are stacked in this order as in the first embodiment, and the disk valve 40 is overlapped with the second embodiment. A similar piston main body 41A, a disk valve 42 similar to the first embodiment, a small diameter disk 43 similar to the first embodiment, a contact disk 313, and a regulating member 76 similar to the first embodiment are stacked in this order. . A nut 35 is screwed onto the male screw 34 that protrudes beyond the regulating member 76 of the mounting shaft portion 32 of the piston rod 21. The disk valve 42 contacts the inner contact portion 61A and the outer contact portion 62A of the piston body 41A to close the annular passage 54A and the passage 52A.

  When the piston 16C is assembled to the piston rod 21, a valve body 71C and a guide disk 72 are superimposed on the shaft step portion 33 in this order on the piston rod 21, and the disk valve 73 is placed on the outer seat 93 of the valve body 71C. It is further stacked. In addition, the support disk 74, the urging disk 78, the contact disk 75, the small diameter disk 300, and the passage forming member 302 are stacked on the disk valve 73 in this order. Then, the case member 306 is fitted on the passage forming member 302 at the bottom portion 304 by fitting the cylindrical portion 305 to the valve main body 71 </ b> C holding the seal member 308. Further, a regulating member 37, a contact disk 38, a small diameter disk 39, a disk valve 40, a piston main body 41A, a disk valve 42, a small diameter disk 43, a contact disk 313, and a regulation member 76 are arranged in this order on the bottom 304 of the case member 306. Overlaid.

  With the components arranged in this manner, the nut 35 is screwed onto the male screw 34 of the mounting shaft portion 32 that protrudes beyond the regulating member 76. Accordingly, the valve main body 71C, the guide disk 72, the support disk 74, the urging disk 78, the contact disk 75, the small diameter disk 300, the passage forming member 302, the bottom 304 of the case member 306, the regulating member 37, the contact disk 38, The small-diameter disk 39, the disk valve 40, the piston main body 41A, the disk valve 42, the small-diameter disk 43, the contact disk 313, and the regulating member 76 are respectively connected to the shaft step portion 33 of the piston rod 21 and the nut 35. It is clamped and clamped in the axial direction. At that time, the disk valve 73 is not clamped in the axial direction, is pressed by the inner sheet 241 of the support disk 74 and elastically deforms, and the guide disk 72 is disposed inside thereof.

  Similar to the second embodiment, the plurality of passages 51A and the annular passage 53 of the piston main body 41A are the compression-side passages 117A through which oil passes when the piston rod 21 and the piston 16C move to the contraction side. A damping force generation mechanism 111 is provided in the compression side passage 117A.

  The plurality of passages 52A and the annular passage 54A serve as a first extension side passage 118C through which oil passes when the piston rod 21 and the piston 16C move to the extension side. Then, the inner abutment portion 61A and the outer abutment portion 62A on both sides in the radial direction of the annular passage 54A and the inner abutment portion 61A and the outer abutment portion 62A are seated so as to close the annular passage 54A. The disc valve 42 constitutes a damping valve 113C that opens and closes the first extension side passage 118C.

  The passage 86C and the annular passage 91C, the chamber 311, the passage groove 301, and the passage hole 310 of the valve main body 71C are provided with a second extension side passage 320 (through which oil passes when the piston rod 21 and the piston 16C move to the extension side. Aisle). Then, the outer side seat 93 radially outside the annular passage 91C, the disc valve 73 placed so as to be seated on the outer seat 93 so as to close the annular passage 91C, and the disc valve 73 so as to close the annular passage 91C. The support disk 74 that is in contact with the above constitutes a damping valve 114 </ b> C that opens and closes the second extension side passage 320. A valve main body 71C including the outer seat 93 is a main body portion of the damping valve 114C. The damping valve 113C and the damping valve 114C constitute an extension-side damping force generation mechanism 115C.

  In the above embodiment, an example in which the present invention is applied to a double cylinder type hydraulic shock absorber has been shown. You may use for the monotube type hydraulic shock absorber which forms a gas chamber with a division body, and can use it for all shock absorbers. Of course, it is possible to apply the present invention to the above-described contraction-side damping force generating mechanism 111 or to apply the present invention to the above-described base valve 25. The present invention is also applicable to the case where an oil passage communicating with the inside of the cylinder 2 is provided outside the cylinder 2 and a damping force generating mechanism is provided in the oil passage. Moreover, in the said embodiment, although the hydraulic shock absorber was shown as an example, water and air can also be used as a fluid.

  In the embodiment described above, a cylinder in which a working fluid is sealed, a piston slidably provided in the cylinder, and one end connected to the piston and extending to the outside of the cylinder are provided. A piston rod that is taken out, a passage through which the working fluid flows by sliding of the piston, and a damping force generation mechanism that is provided in a part of the passage and suppresses the flow of the working fluid to generate a damping force, The damping force generating mechanism includes a valve main body through which the passage passes, an annular outer seat surrounding one end opening of the passage, and an annular disc valve mounted on one side of the outer seat so as to be seated. And an inner seat having a smaller diameter than the outer seat that can come into contact with the other side surface of the disc valve, and the outer side of the disc valve is disposed on the other side surface of the disc valve. Biasing means for urging said outer sheet is provided. As described above, since the urging means for urging the outer peripheral side of the disc valve toward the outer seat is provided on the other side surface of the disc valve, the damping force is reduced as compared with the case where no urging means is provided. Can be hard. Further, the damping force characteristic can be further changed by changing the biasing means to one having a different characteristic. Therefore, the damping force characteristic can be easily tuned.

  Further, since the biasing means is plate-shaped and the inner peripheral side is clamped, the disk valve can be biased with a stable spring force by the biasing means while suppressing an increase in cost.

DESCRIPTION OF SYMBOLS 1 Buffer 2 Cylinder 16 Piston 21 Piston rod 71, 71C Valve body 73 Disc valve 78 Energizing disk (urging means)
93 Outer sheet 115, 115C Damping force generation mechanism 118, 118A, 320 Extension side passage (passage)
241 inner sheet

Claims (2)

A cylinder filled with a working fluid;
A piston slidably provided in the cylinder and defining the inside of the cylinder;
A piston rod having one end connected to the piston and extending to the outside of the cylinder;
A passage through which a working fluid flows by sliding the piston;
A damping force generation mechanism that is provided in a part of the passage and suppresses the flow of the working fluid to generate a damping force;
With
The damping force generation mechanism is
A valve body through which the passage extends, and
An annular outer sheet surrounding one end opening of the passage;
An annular disc valve mounted so that one side surface can be seated on the outer seat;
An inner seat having a smaller diameter than the outer seat, which can contact the other side of the disc valve;
Have
A shock absorber characterized in that a biasing means for biasing the outer peripheral side of the disc valve toward the outer seat is provided on the other side surface of the disc valve.   The shock absorber according to claim 1, wherein the urging means is plate-shaped and has an inner peripheral side clamped.

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