JP2018105378A - Damper - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a damper which can be shortened in an axial length.SOLUTION: A damper has: a frequency sensing part 200 arranged at a piston rod 41 which deforms the inside of a housing 210 while defining it into first chamber communication chambers 281, 282 and 284 communicating with a first chamber, and a second chamber communication chamber 283 communicating with a second chamber 32, and reduces the chamber 283 while expanding the chambers 281, 282 and 284 in an elongation stroke in which a working fluid flows into the second chamber 32 from the first chamber; and a plate-shaped valve body 202 which deforms the inside of the housing 210 while defining it into the second chamber communication chambers 283, 282 and 284, and the first chamber communication chamber 281, and reduces the chamber 281 while expanding the chambers 283, 282 and 284 in a contraction stroke in which the working fluid flows into the first chamber from the second chamber 32. By this constitution, attenuation force characteristics of both the elongation stroke and the contraction stroke are made variable, and an axial length can be thereby shortened.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a shock absorber.

  Some shock absorbers include a damping force varying mechanism that varies the damping force according to the frequency (see, for example, Patent Document 1).

JP 2011-202800 A

  There is a demand for shortening the axial length of the shock absorber.

  Therefore, an object of the present invention is to provide a shock absorber capable of shortening the axial length.

  In order to achieve the above object, the present invention provides a first passage and a second passage through which a working fluid flows from one of the first chamber and the second chamber by movement of a piston, and a damping force provided in the first passage. A first valve body to be generated, and a first chamber communication chamber that is provided in the second passage and communicates with the first chamber in a housing in an extending stroke in which a working fluid flows from the first chamber to the second chamber. The second chamber communicating chamber is reduced from the second chamber while the first chamber communicating chamber is expanded while the first chamber communicating chamber is enlarged while being deformed while defining the second chamber communicating chamber communicating with the second chamber, and the first chamber is operated from the second chamber to the first chamber. A plate-like shape that reduces the size of the first chamber communication chamber while expanding the second chamber communication chamber by deforming while defining the second chamber communication chamber and the first chamber communication chamber in the contraction process through which the fluid flows A frequency sensitive part having a second valve body.

  According to the present invention, it is possible to shorten the axial length.

It is sectional drawing which shows the shock absorber of one Embodiment which concerns on this invention. It is a fragmentary sectional view which shows the piston periphery of the buffer of one Embodiment which concerns on this invention. It is a fragmentary sectional view which shows the frequency sensitive part periphery of the buffer of one Embodiment concerning this invention. It is a fragmentary sectional view showing the frequency sensitive part circumference of a shock absorber of one embodiment concerning the present invention, (a) is an extension stroke, (b) is the deformation direction of a valve body and the flow of oil liquid in a contraction stroke. Explain. 1 is a hydraulic circuit diagram showing a shock absorber according to a first embodiment of the present invention. It is a characteristic diagram which shows notionally the relationship of the damping force with respect to the piston speed of the buffer of 1st Embodiment which concerns on this invention.

  An embodiment according to the present invention will be described with reference to the drawings. 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 11 of the present embodiment is a so-called single cylinder type hydraulic shock absorber, and has a cylinder 12 in which an oil liquid as a working fluid is enclosed. The cylinder 12 is a bottomed cylindrical integrally formed product, and a cover 15 is attached so as to cover the upper opening side. A plate-like body 16 is attached to the cover 15 on the side opposite to the cylinder 12. The cylinder 12 includes a cylindrical body portion 21 and a bottom portion 22 that closes a lower portion of the body portion 21, and the side opposite to the bottom portion 22 of the body portion 21 is open.

  The cover 15 includes a tubular portion 25 and an inner flange portion 26 that extends radially inward from the upper end side of the tubular portion 25. The cover 15 is covered on the opening side of the barrel portion 21 so that the upper end opening of the barrel portion 21 is covered with the inner flange portion 26 and the outer peripheral surface of the barrel portion 21 is covered with the cylindrical portion 25. A part of the shape portion 25 is fixed to the body portion 21 by being crimped radially inward. The plate-like body 16 is fixed on the opposite side of the inner flange portion 26 from the cylindrical portion 25.

  A piston 30 is slidably fitted in the body portion 21 of the cylinder 12. The piston 30 divides the inside of the cylinder 12 into two chambers, a first chamber 31 and a second chamber 32. A partition piston 35 is provided in the body portion 21 of the cylinder 12 on the bottom 22 side of the piston 30. The partition piston 35 is partitioned from the second chamber 32 between the bottom portion 22 and a chamber 36 is formed. An oil liquid as a working fluid is sealed in the first chamber 31 and the second chamber 32 in the cylinder 12, and a high-pressure gas is sealed in the chamber 36 in the cylinder 12.

  One end of the piston rod 41 is inserted into the cylinder 12 from the opening side, and the other end of the piston rod 41 extends to the outside of the cylinder 12. The piston 30 is connected to one end side of the piston rod 41 disposed in the cylinder 12. The piston 30 and the piston rod 41 move together. In the expansion stroke in which the piston rod 41 increases the amount of protrusion from the cylinder 12, the piston 30 moves to the first chamber 31 side. In the contraction stroke in which the piston rod 41 decreases the amount of protrusion from the cylinder 12, the piston 30 It moves to the second chamber 32 side. The first chamber 31 is a chamber on the piston rod 41 side where the piston rod 41 is arranged, and the second chamber 32 is a bottom chamber on the bottom 22 side of the cylinder 12.

  A rod guide 42 is fitted to the upper end opening side of the cylinder 12, and a seal member 43 is fitted to the upper side which is the outside of the cylinder 12 relative to the rod guide 42. A part of the upper end portion of the cylinder 12 is caulked inward in the radial direction to lock the seal member 43. A friction member 44 is provided between the rod guide 42 and the seal member 43. The rod guide 42, the seal member 43, and the friction member 44 all have an annular shape, and the piston rod 41 is slidably inserted inside each of the rod guide 42, the friction member 44, and the seal member 43. It extends to the outside of the cylinder 12.

  Here, the rod guide 42 supports the piston rod 41 so as to be movable in the axial direction while restricting its radial movement, and guides the movement of the piston rod 41. The seal member 43 is in close contact with the cylinder 12 at the outer peripheral portion thereof, and is slidably contacted with the outer peripheral portion of the piston rod 41 moving in the axial direction at the inner peripheral portion thereof, so that oil in the cylinder 12 leaks to the outside. To prevent. The friction member 44 is in sliding contact with the outer peripheral portion of the piston rod 41 at the inner peripheral portion thereof, and generates frictional resistance on the piston rod 41. The friction member 44 is not intended for sealing.

  The piston rod 41 is inserted into the rod guide 42, the seal member 43, and the friction member 44 so as to extend from the cylinder 12 to the outside, and the internal thread 52 on the end of the rod body 51 on the inner side of the cylinder 12. A distal end rod 55 that is screwed to extend from the rod main body 51 toward the bottom 22 side, an annular member 57 that is inserted through the rod main body 51 in contact with the distal end rod 55, and the annular member 57 is connected to the distal end rod 55. It is comprised from the nut member 58 screwed together by the external thread 52 so that it may pinch | interpose between.

  A locking member 61 is fixed to the outer peripheral portion of the rod body 51 on the tip rod 55 side. On the outer peripheral side of the rod body 51, annular spring receivers 62 and 63 are provided between the locking member 61 and the rod guide 42. These spring receivers 62 and 63 are slidable along the rod body 51 by inserting the rod body 51 inward. A rebound spring 64 made of a coil spring is interposed between the spring receivers 62 and 63 so that the rod main body 51 is inserted inside thereof. Opposite to the rebound spring 64 of the spring receiver 63 on the rod guide 42 side, a buffer body 65 made of an annular elastic material is provided. The buffer body 65 is also slidable along the rod body 51 by inserting the rod body 51 inward.

  The distal end rod 55 has a base shaft portion 71 in which a female screw 54 is formed, and a mounting shaft portion 72 having a smaller diameter. A piston 30 or the like is attached to the attachment shaft portion 72. An end portion of the base shaft portion 71 on the mounting shaft portion 72 side is a shaft step portion 73 that extends along the direction orthogonal to the axis. A passage groove 75 extending in the axial direction is formed at an axially intermediate position on the outer peripheral portion of the mounting shaft portion 72, and a male screw 76 is formed at a distal end position opposite to the base shaft portion 71 in the axial direction. ing. The passage groove 75 is formed such that a cross-sectional shape on a surface orthogonal to the central axis of the piston rod 41 is any one of a rectangle, a square, and a D-shape.

  In the shock absorber 11, for example, a protruding portion of the piston rod 41 from the cylinder 12 is disposed at the top and supported by the vehicle body, and the bottom 22 side of the cylinder 12 is disposed at the bottom and coupled to the wheel side. On the contrary, the cylinder 12 side may be supported by the vehicle body, and the piston rod 41 may be connected to the wheel side. When the wheels vibrate as the vehicle travels, the positions of the cylinder 12 and the piston rod 41 change relatively with the vibration. The change is a flow path formed in at least one of the piston 30 and the piston rod 41. It is suppressed by the fluid resistance. As will be described in detail below, the fluid resistance of the flow path formed in at least one of the piston 30 and the piston rod 41 is made to vary depending on the vibration speed and amplitude. Is improved. Between the cylinder 12 and the piston rod 41, in addition to vibrations generated by the wheels, inertial force and centrifugal force generated in the vehicle body as the vehicle travels also act. For example, a centrifugal force is generated in the vehicle body when the traveling direction is changed by a steering operation, and a force based on the centrifugal force acts between the cylinder 12 and the piston rod 41. As will be described below, the shock absorber 11 has good characteristics with respect to vibration based on the force generated in the vehicle body as the vehicle travels, and high stability in vehicle travel can be obtained.

  As shown in FIG. 2, the piston 30 has a piston main body 83. The piston body 83 is integrated with two metal piston components 80 and 81 that are connected to each other and fitted with the mounting shaft 72 of the tip rod 55 on the inner periphery thereof, and the outer peripheral surfaces of the piston components 80 and 81. And an annular synthetic resin sliding member 82 that slides in the cylinder 12. In the piston 30, the piston body 83 divides the inside of the cylinder 12 into two chambers, a first chamber 31 and a second chamber 32.

  The piston body 83 has a plurality of passage holes 88 (only one is shown in the cross-sectional view in FIG. 2) that can communicate with the first chamber 31 and the second chamber 32 by penetrating in the axial direction, and the axial direction. A plurality of passage holes 89 (only one location is shown in FIG. 2 because of its cross-section) are provided so that the first chamber 31 and the second chamber 32 can communicate with each other. In other words, the passages in the plurality of passage holes 88 and the passages in the plurality of passage holes 89 flow so that the oil liquid as the working fluid flows between the first chamber 31 and the second chamber 32 by the movement of the piston 30. Communicate. The passage holes 88 are formed at an equal pitch in the circumferential direction of the piston main body 83 with one passage hole 89 interposed therebetween, and one side in the axial direction of the piston main body 83 (the upper side in FIG. 2) is the diameter. The other side in the axial direction (the lower side in FIG. 2) is open radially inward on the outer side in the direction.

  A damping force generation mechanism 90 that generates a damping force is provided for the half of the passage holes 88. The damping force generation mechanism 90 includes a valve body 91 (first valve body) that is disposed on the second chamber 32 side, which is one end side in the axial direction of the piston main body 83, and is attached to the piston rod 41. In the passage hole 88, the oil passage passes through the inside passage of the piston 30 toward the first chamber 31, that is, the extension stroke in which the piston rod 41 and the piston 30 move to the extension side (upper side in FIG. 2). The extension-side passage 108 (first passage) is configured, and a damping force generation mechanism 90 provided for the extension-side passage 108 suppresses the flow of the oil liquid in the extension-side passage 108 and generates a damping force. It is a side damping force generation mechanism. The valve body 91 is provided in the passage 108 and generates a damping force.

  The other half of the passage holes 89 are formed at an equal pitch in the circumferential direction of the piston body 83 with one passage hole 88 interposed therebetween, and the other side in the axial direction of the piston body 83. (The lower side in FIG. 2) is open radially outward, and one side in the axial direction (upper side in FIG. 2) is open radially inward.

  A damping force generating mechanism 92 that generates a damping force is provided in the remaining half of the passage holes 89. The damping force generation mechanism 92 includes a valve body 93 that is disposed on the first chamber 31 side that is the other end side in the axial direction of the piston body 83 and is attached to the piston rod 41. In the passage hole 89, the oil passage passes through the inner passage when the piston 30 moves toward the second chamber 32, that is, when the piston rod 41 and the piston 30 move toward the contraction side (lower side in FIG. 2). The contraction-side passage 119 (first passage) is configured, and the damping force generation mechanism 92 provided for the passages 119 suppresses the flow of oil in the passage in the contraction-side passage 119, thereby reducing the damping force. This is a contraction-side damping force generation mechanism that generates The valve body 93 is provided in the passage 119 and generates a damping force.

  The piston main body 83 has an annular shape, and the mounting shaft portion 72 of the tip rod 55 is fitted to the inner peripheral portion thereof. At the end of the piston body 83 on the second chamber 32 side in the axial direction, an annular force constituting the damping force generating mechanism 90 is formed with the valve body 91 on the radially outer side of the opening of the passage hole 88 on the second chamber 32 side. The valve seat portion 97 is formed. In addition, a damping force generating mechanism 92 is configured with a valve body 93 at an end portion on the first chamber 31 side in the axial direction of the piston body 83, radially outside the opening of the passage hole 89 on the first chamber 31 side. An annular valve seat 99 is formed.

  In the piston main body 83, the outer peripheral side of the valve seat portion 97 has a step shape whose axial direction height is lower than that of the valve seat portion 97, and the second chamber 32 of the passage hole 89 on the contraction side is formed in this step shape portion. A side opening is arranged. Similarly, in the piston main body 83, the outer peripheral side of the valve seat part 99 has a stepped shape whose axial direction height is lower than that of the valve seat part 99, and the extending side passage hole 88 is formed in this stepped part. An opening on the first chamber 31 side is arranged.

  The valve body 91 is formed by stacking a plurality of perforated disk-shaped discs 101, the outer diameter of the disc 101 on the most piston body 83 side is the largest, and the most opposite side to the piston body 83. The outer diameter of the disk 101 is smaller than this. Further, the outer diameter of the disk 101 at the intermediate portion in the stacking direction is the intermediate diameter thereof. A mounting shaft 72 is fitted to the inner periphery of the disc 101. The valve body 91 is in contact with the valve seat portion 97 of the piston body 83 by the disk 101 closest to the piston body 83 to open and close the passage in the passage hole 88.

  A plurality of perforated disc-shaped disks 103 are provided between the valve body 91 and the piston body 83. Each of these disks 103 has an outer diameter smaller than the inner diameter of the valve seat portion 97. On the opposite side of the valve body 91 from the piston main body 83, a perforated disk-shaped disk 104 is provided. The disc 104 has a smaller outer diameter than the disc 101 at the end opposite to the piston body 83 of the valve body 91. On the opposite side of the disc 104 from the valve body 91, a perforated disc-like disc 105 is provided. The outer diameter of the disk 105 is larger than that of the disk 104. A mounting shaft portion 72 is fitted to the inner peripheral portions of the disks 103 to 105.

  The valve body 91 can be detached from and seated on the valve seat portion 97, and by being separated from the valve seat portion 97, the passage in the passage hole 88 can be opened to the second chamber 32. The flow of the oil liquid to the two chambers 32 is allowed and suppressed. The disc 101 abutting on the valve seat portion 97 of the valve body 91 has a notch 107 formed on the outer peripheral side. This notch 107 is the same even when the disc 101 is in contact with the valve seat portion 97. A fixed orifice 106 that allows the first chamber 31 and the second chamber 32 to communicate with each other is constituted by a valve seat portion 97. The disk 105 suppresses deformation beyond the regulation in the opening direction of the valve body 91.

  The passage in the extension-side passage hole 88 provided in the piston body 83, the fixed orifice 106, and the gap between the valve body 91 and the valve seat portion 97 at the time of separation are caused by the movement of the piston 30 in the extension stroke. An extending-side passage 108 from which the oil liquid flows from the first chamber 31 toward the second chamber 32 is configured. The extension-side damping force generation mechanism 90 is provided in the extension-side passage 108 to generate a damping force.

  The valve body 93 is configured by stacking a plurality of perforated disk-shaped disks 111, and the outer diameter of the disk 111 on the most piston body 83 side is the largest, and the most opposite side to the piston body 83. The outer diameter of the disk 111 is smaller than this. Further, the outer diameter of the disk 111 at the intermediate portion in the stacking direction is the intermediate diameter thereof. A mounting shaft 72 is fitted to the inner periphery of these disks 111. The valve body 93 abuts on the valve seat 99 of the piston body 83 with the disk 111 closest to the piston body 83 to open and close the passage in the passage hole 89.

  Between the valve body 93 and the piston main body 83, a plurality of perforated disc-shaped disks 113 are provided. These disks 113 have the same outer diameter, and the outer diameter is smaller than the inner diameter of the valve seat portion 99. On the opposite side of the valve body 93 from the piston body 83, a perforated disk-shaped disk 114 is provided. The disc 114 has a smaller outer diameter than the disc 111 at the end of the valve body 93 opposite to the piston body 83. On the opposite side of the disc 114 from the valve body 93, a plurality of perforated disc-like discs 115 are provided. These disks 115 have the same outer diameter, and the outer diameter is larger than that of the disk 114. On the opposite side of the disk 115 from the disk 114, a perforated disk-shaped disk 116 is provided. The disk 116 has a smaller outer diameter than the disk 115. A mounting shaft portion 72 is fitted to the inner peripheral portions of the disks 113 to 116.

  The valve body 93 can be detached from and seated on the valve seat portion 99, and the passage in the passage hole 89 can be opened to the first chamber 31 by being separated from the valve seat portion 99. The flow of the oil liquid to the one chamber 31 is allowed and suppressed. The disc 111 that contacts the valve seat portion 99 of the valve body 93 has a cutout portion 118 formed on the outer peripheral side. The notch 118 forms a fixed orifice 117 with the valve seat 99 that allows the first chamber 31 and the second chamber 32 to communicate with each other even when the disk 111 is in contact with the valve seat 99. The disc 115 suppresses deformation beyond the regulation in the opening direction of the valve body 93.

  The passage in the contraction-side passage hole 89 provided in the piston main body 83, the fixed orifice 117, and the clearance between the valve body 93 and the valve seat portion 99 at the time of separation are caused by the movement of the piston 30 in the contraction stroke. A contraction-side passage 119 from which the oil liquid flows from the second chamber 32 toward the first chamber 31 is configured. The contraction-side damping force generating mechanism 92 is provided in the contraction-side passage 119 and generates a damping force.

  A valve mechanism 131 is provided on the mounting shaft portion 72 of the tip rod 55 adjacent to the opposite side of the disc 116 from the valve body 93. The valve mechanism 131 constitutes the piston 30 together with the piston main body 83. The valve mechanism 131 includes a case body 132, a passage forming member 133, a valve body 134 (third valve body), a seat member 135, an O-ring 136, and a valve body 137 (third valve body). ing.

  The case body 132 includes a perforated disk-shaped bottom plate portion 141 and a cylindrical tubular portion 142 extending in the axial direction from the outer peripheral side of the bottom plate portion 141, and the inner peripheral portion of the bottom plate portion 141. The mounting shaft portion 72 is fitted to. In the case body 132, the bottom plate portion 141 is in contact with the disk 116, and the cylindrical portion 142 extends from the bottom plate portion 141 in the direction opposite to the disk 116.

  The passage forming member 133 is disposed in the cylindrical portion 142 of the case body 132. The passage forming member 133 includes a cylindrical passage forming portion 145 and an annular inner flange portion 146 that protrudes radially inward from one axial end side of the passage forming portion 145. The attachment shaft portion 72 is fitted to the inner peripheral portion of the inner flange portion 146, and the passage forming portion 145 is in contact with the bottom plate portion 141 of the case body 132. A passage groove 147 penetrating in the radial direction is formed in the passage forming portion 145. The passage groove 75 of the attachment shaft portion 72 crosses the bottom plate portion 141 of the case body 132 and opens at a position between the inner flange portion 146 and the bottom plate portion 141. A valve body 134 is provided on the side opposite to the bottom plate portion 141 of the passage forming member 133.

  The sheet member 135 has an annular shape, and the attachment shaft portion 72 is fitted to the inner peripheral portion. The sheet member 135 is disposed in the cylindrical portion 142 of the case body 132 and is disposed on the opposite side of the valve body 134 from the passage forming member 133. The sheet member 135 has an O-ring 136 attached to the outer peripheral portion thereof, and is fitted into the cylindrical portion 142 of the case body 132 at the outer peripheral portion. At that time, the O-ring 136 seals the gap between the sheet member 135 and the case body 132. The sheet member 135 is formed by partitioning the intermediate chamber 150 from the first chamber 31 between the case body 132 and the sheet member 135.

  The sheet member 135 communicates a plurality of passage holes 151 (only one is shown in the cross-sectional view in FIG. 2) communicating the first chamber 31 and the intermediate chamber 150, and the first chamber 31 and the intermediate chamber 150. There are provided a plurality of passage holes 152 (only one place is shown in FIG. 2 because of the cross section). In the circumferential direction of the sheet member 135, the passage holes 151 are formed at an equal pitch with a passage hole 152 interposed therebetween, and one side of the sheet member 135 in the axial direction (the upper side in FIG. 2) has a diameter. The other side in the axial direction (the lower side in FIG. 2) is open radially inward on the outer side in the direction.

  A damping force generation mechanism 155 including a valve element 134 that generates a damping force is provided for the half of the passage holes 151. The valve body 134 of the damping force generation mechanism 155 is disposed on the intermediate chamber 150 side on one end side in the axial direction of the seat member 135 and is attached to the piston rod 41. The passage in the passage hole 151 is a passage on the extension side through which the oil liquid passes when the piston rod 41 and the piston 30 move to the extension side (upper side in FIG. 2). The mechanism 155 is an extension-side damping force generation mechanism that generates a damping force by suppressing the flow of the oil liquid in the passage in the extension-side passage hole 151.

  The other half of the passage holes 152 are formed at an equal pitch in the circumferential direction of the sheet member 135 with one passage hole 151 therebetween, and the other side of the sheet member 135 in the axial direction. (The lower side in FIG. 2) is open radially outward, and one side in the axial direction (upper side in FIG. 2) is open radially inward.

  A damping force generation mechanism 156 including a valve body 137 that generates a damping force is provided for the remaining half of the passage holes 152. The valve body 137 of the damping force generation mechanism 156 is disposed on the opposite side to the intermediate chamber 150, which is the other end side of the seat member 135 in the axial direction, and is attached to the piston rod 41. The passage in the passage hole 152 is a passage on the contraction side through which the oil liquid passes when the piston rod 41 and the piston 30 move to the contraction side (lower side in FIG. 2), and a damping force provided to these passages. The generation mechanism 156 is a contraction-side damping force generation mechanism that generates a damping force by suppressing the flow of oil in the passage in the contraction-side passage hole 152.

  An annular valve that forms a damping force generating mechanism 155 with a valve body 134 at the end of the seat member 135 on the intermediate chamber 150 side in the axial direction and radially outside the opening of the passage hole 151 on the intermediate chamber 150 side. A sheet portion 161 is formed. Further, a damping force generating mechanism 156 is formed at the end of the seat member 135 on the opposite side to the intermediate chamber 150 in the axial direction with the valve body 137 radially outside the opening of the passage hole 152 on the first chamber 31 side. An annular valve seat portion 162 is formed.

  In the seat member 135, the radially outer side of the valve seat portion 161 has a step shape whose axial direction height is lower than that of the valve seat portion 161, and the intermediate chamber 150 of the passage hole 152 on the contraction side is formed in this step shape portion. A side opening is arranged. Similarly, in the seat member 135, the radially outer side of the valve seat portion 162 has a stepped shape having a lower axial height than the valve seat portion 162, and an extended passage hole is formed in the stepped portion. An opening 151 on the first chamber 31 side is arranged.

  The valve body 134 is configured by stacking a plurality of perforated disk-shaped discs 171. The outermost diameter of the disc 171 on the most sheet member 135 side is the largest, and the most opposite side to the seat member 135. The outer diameter of the disk 171 is smaller than this. Further, the outer diameter of the disk 171 at the intermediate portion in the stacking direction is the intermediate diameter thereof. A mounting shaft portion 72 is fitted to the inner peripheral portion of the disc 171. The valve body 134 abuts on the valve seat portion 161 of the seat member 135 with the disc 171 closest to the seat member 135 to open and close the passage in the passage hole 151.

  A plurality of perforated disk-shaped discs 173 are provided between the valve body 134 and the seat member 135. These disks 173 have the same outer diameter, and the outer diameter is smaller than the inner diameter of the valve seat portion 161. A plurality of perforated disk-shaped discs 174 are provided on the opposite side of the valve body 134 from the sheet member 135. These disks 174 have the same outer diameter, and the outer diameter is smaller than the disk 171 at the end of the valve body 134 on the side opposite to the seat member 135. On the opposite side of the disc 174 from the valve element 134, a plurality of perforated disc-shaped discs 175 are provided. These disks 175 have the same outer diameter, and the outer diameter is larger than that of the disk 174. A mounting shaft portion 72 is fitted to the inner peripheral portions of these disks 173 to 175. The disk 175 is in contact with the inner flange portion 146 of the passage forming member 133.

  The valve body 134 can be detached from and seated on the valve seat portion 161, and the passage in the passage hole 151 can be opened to the intermediate chamber 150 by being separated from the valve seat portion 161. The valve body 134 suppresses the flow of the oil liquid from the first chamber 31 to the intermediate chamber 150 while allowing it. The disc 171 that contacts the valve seat portion 161 of the valve body 134 has a notch 177 formed on the outer peripheral side. The cutout portion 177 forms a fixed orifice 176 with the valve seat portion 161 that allows the first chamber 31 and the intermediate chamber 150 to communicate with each other even when the disc 171 is in contact with the valve seat portion 161. The disk 175 suppresses deformation beyond the regulation in the opening direction of the valve body 134.

  The valve body 137 is configured by stacking a plurality of perforated disc-shaped disks 181, the outer diameter of the disk 181 closest to the sheet member 135 is the largest, and the most opposite side of the sheet member 135. The outer diameter of the disk 181 is smaller than this. Further, the outer diameter of the disk 181 at the intermediate portion in the stacking direction is the intermediate diameter thereof. A mounting shaft 72 is fitted to the inner periphery of these disks 181. The valve body 137 contacts the valve seat portion 162 of the seat member 135 with the disk 181 closest to the seat member 135 to open and close the passage in the passage hole 152.

  Between the valve body 137 and the seat member 135, a plurality of perforated disc-shaped disks 183 are provided. These discs 183 have the same outer diameter, and the outer diameter is smaller than the inner diameter of the valve seat portion 162. A plurality of discs 184 are provided on the opposite side of the valve body 137 from the sheet member 135. These disks 184 have the same outer diameter, and the outer diameter is smaller than the disk 181 at the end of the valve body 137 opposite to the seat member 135. On the opposite side of the disk 184 from the valve body 134, a perforated disk-shaped disk 185 is provided. The outer diameter of the disk 185 is larger than that of the disk 184. An annular member 186 is provided on the opposite side of the disk 185 from the disk 184. The annular member 186 has a smaller outer diameter than the disk 185. The mounting shaft portion 72 is fitted to the inner peripheral portions of the disks 183 to 185 and the annular member 186. The annular member 186 is in contact with the shaft step portion 73 of the tip rod 55.

  The valve body 137 can be detached from the valve seat portion 162, and the passage in the passage hole 152 can be opened to the first chamber 31 by being separated from the valve seat portion 162. The valve body 137 suppresses the flow of oil from the intermediate chamber 150 to the first chamber 31 while allowing it. The disc 181 that contacts the valve seat portion 162 of the valve body 137 has a notch 188 formed on the outer peripheral side. The notch 188 constitutes a fixed orifice 187 that connects the first chamber 31 and the intermediate chamber 150 with the valve seat 162 even when the disk 181 is in contact with the valve seat 162. The disk 185 suppresses deformation beyond the regulation in the opening direction of the valve body 137.

  As shown in FIG. 3, the mounting shaft 72 of the tip rod 55 is adjacent to the opposite side of the disc 105 from the valve body 91, and the reciprocating frequency of the piston 30 in the expansion stroke and the contraction stroke (hereinafter referred to as piston). A frequency sensitive unit 200 that varies the damping force in response to the frequency) is provided.

  The frequency sensitive unit 200 includes a case member 201, a valve body 202 (second valve body), and a lid member 203 in order from the disk 105 side in the axial direction. An attachment shaft portion 72 of the tip rod 55 is fitted to the inner peripheral portion of the case member 201 and the lid member 203. A portion of the attachment shaft portion 72 that is disposed in the case member 201 constitutes the frequency sensitive portion 200. The valve body 202 has a perforated disk shape, and is disposed in the case member 201 with the attachment shaft portion 72 penetrating inside. The lid member 203 is fitted to the case member 201 to form a housing 210 that houses the valve body 202 with the case member 201.

  The case member 201 includes a perforated disk-shaped base 211 along the direction perpendicular to the axis, an annular annular protrusion 212 protruding from the inner peripheral end of the base 211 toward the axial direction, and an inner peripheral portion of the base 211 A cylindrical inner cylindrical portion 213 that protrudes from the radially outer side to the other side in the axial direction, and the inner cylindrical portion 213 on the same side from an intermediate position outside the radial inner cylindrical portion 213 of the base 211. Further, a cylindrical sheet portion 214 (second support wall portion) that protrudes from the inner cylindrical portion 213, and a cylinder that extends from the outer peripheral edge of the base 211 to the same side as the sheet portion 214 and extends beyond the sheet portion 214. And an outer peripheral wall portion 215. The inner peripheral surface of the outer peripheral wall portion 215 is a cylindrical surface 216 having a constant diameter.

  The attachment shaft portion 72 of the tip rod 55 is fitted to the base portion 211 of the case member 201 and the inner peripheral portion of the annular projecting portion 212. The passage groove 75 of the attachment shaft portion 72 is opened at a position that crosses the base portion 211 and the annular projecting portion 212 in the axial direction and overlaps the inner cylindrical portion 213 in the axial direction. The passage groove 75 includes a bottom plate portion 141, a disc 116, a plurality of discs 115, a disc 114, a valve body 93, a plurality of discs 113, a piston main body 83, a plurality of discs 103, a valve of the case body 132 shown in FIG. The body 91, the disk 104, the disk 105, and the annular protrusion 212 and the base 211 of the case member 201 shown in FIG.

  The inner cylindrical portion 213 is formed with a plurality of cutout portions 220 that partially penetrate in the radial direction in the circumferential direction at equal intervals in the circumferential direction, whereby the radial direction of the inner cylindrical portion 213 in the case member 201 is formed. The inner side and the radially outer side always communicate with each other through a passage in the notch 220. The sheet portion 214 is formed with a plurality of cutout portions 221 that partially penetrate in the radial direction in the circumferential direction at equal intervals in the circumferential direction, whereby the radial direction inner side and the radial direction of the sheet portion 214 in the case member 201 are formed. The outside always communicates with the passage in the notch 221. The sheet portion 214 has a tapered surface 225 that is inclined so that the radially outer side has a larger diameter toward the base portion 211 side.

  The lid member 203 includes a perforated disk-shaped base portion 231 along the direction perpendicular to the axis, a cylindrical inner cylindrical portion 232 that protrudes slightly outward in the axial direction from the inner peripheral portion of the base portion 231, and A cylindrical sheet portion 233 (first support wall portion) that protrudes shorter than the inner cylindrical portion 232 to the same side as the inner cylindrical portion 232 from an intermediate position radially outside the inner cylindrical portion 232 of the base portion 231. And have. The outer peripheral surface of the inner cylindrical portion 232 is a cylindrical surface 234 having a constant diameter. The attachment shaft portion 72 of the tip rod 55 is fitted to the inner peripheral portion of the base portion 231 of the lid member 203.

  The sheet portion 233 is formed with a plurality of cutout portions 238 that penetrate in the radial direction partially in the circumferential direction at equal intervals in the circumferential direction, whereby the radial direction inner side and the radial direction of the sheet portion 233 in the lid member 203 are formed. The outside always communicates with the passage in the notch 238. The sheet portion 233 has a tapered surface 239 that is inclined so that the inner side in the radial direction has a smaller diameter toward the base portion 231 side. In the base portion 231 of the lid member 203, a plurality of through holes 240 that penetrates in the axial direction outward in the radial direction from the sheet portion 233 are formed at intervals in the circumferential direction.

  The lid member 203 has a posture in which the inner cylindrical portion 232 and the sheet portion 233 protrude toward the base 211 side of the case member 201, and the outer periphery of the case member 201 reaches a position where the inner cylindrical portion 232 contacts the inner cylindrical portion 213. The housing 210 is configured by being fitted in the wall portion 215. The inner cylindrical portion 232 of the lid member 203 and the inner cylindrical portion 213 of the case member 201 have the same inner and outer diameters, and are in contact with each other to form the inner peripheral wall portion 241.

  In the housing 210, an inner peripheral wall portion 241, a seat portion 233, a seat portion 214, and an outer peripheral wall portion 215 are arranged coaxially in order from the radially inner side. A through hole 240 is disposed between the seat portion 233 and the outer peripheral wall portion 215. The tip position of the case member 201 on the opposite side to the base portion 211 of the sheet portion 214 is separated from the base portion 231 of the lid member 203, and the tip position of the lid member 203 opposite to the base portion 231 of the sheet portion 233 is The case member 201 is separated from the base portion 211. The housing 210 has high rigidity and is difficult to deform.

  The valve body 202 includes a perforated disk-shaped main body member 251, an inner peripheral lip seal 253 (first lip seal) joined to the inner peripheral side of one surface 252 (first surface) of the main body member 251, and The outer peripheral lip seal 256 (second lip seal) is joined to the outer peripheral side of the surface 255 (second surface) opposite to the surface 252 of the main body member 251. The valve body 202 can be elastically deformed, that is, bendable.

  The perforated disc-shaped main body member 251 is made of a metal having a spring property such as spring steel, and has a flat plate shape with a constant thickness in a natural state before being incorporated into the housing 210. The main body member 251 has an inner diameter larger than the outer diameter of the inner peripheral wall portion 241 and smaller than the minimum inner diameter of the seat portion 233, and has an outer diameter smaller than the inner diameter of the outer peripheral wall portion 215 and the seat portion 214. The diameter is larger than the maximum outer diameter.

  The inner peripheral lip seal 253 is made of an elastic material having a sealing property such as rubber, and has a perforated disk-shaped base portion 261 and an annular outer peripheral lip that protrudes from the outer peripheral edge portion of the base portion 261 to one side in the axial direction. A portion 262 and an annular inner peripheral lip 263 projecting from the inner peripheral edge of the base 261 to the same side as the outer peripheral lip 262. In a natural state before being assembled in the housing 210, the inner peripheral lip seal 253 has a tapered shape with a larger diameter as the outer peripheral lip portion 262 moves away from the base portion 261 in the axial direction, and the inner peripheral lip portion 263 extends from the base portion 261. It has a tapered shape with a smaller diameter as it goes away in the axial direction. Therefore, the inner peripheral lip seal 253 is a cup seal having a V-shaped cross section on the plane including the central axis. The inner peripheral lip seal 253 is coaxial with the main body member 251 on the inner peripheral edge side of the surface 252 of the main body member 251 on the surface opposite to the outer peripheral lip portion 262 of the base portion 261 and the protruding side of the inner peripheral lip portion 263. It is glued and fixed as it is.

  The outer peripheral lip seal 256 is made of an elastic material having a sealing property such as rubber, and has a perforated disk-shaped base portion 271 and an annular outer peripheral lip portion that protrudes from the outer peripheral edge portion of the base portion 271 to the axial direction side. 272 and an annular inner peripheral lip 273 projecting from the inner peripheral edge of the base 271 to the same side as the outer peripheral lip 272. In a natural state before being assembled into the housing 210, the outer peripheral lip seal 256 has a tapered shape with a larger diameter as the outer peripheral lip portion 272 is separated from the base portion 271 in the axial direction, and the inner peripheral lip portion 273 is pivoted from the base portion 271. The taper has a smaller diameter as the distance increases. Therefore, the outer peripheral lip seal 256 is a cup seal having a V-shaped cross section on the plane including the central axis. The outer peripheral lip seal 256 has an inner and outer diameter larger than the inner peripheral lip seal 253. The outer peripheral lip seal 256 is coaxial with the main body member 251 on the outer peripheral edge side of the surface 255 of the main body member 251 on the surface opposite to the protruding side of the outer peripheral lip portion 272 and the inner peripheral lip portion 273 of the base portion 271. So that it is glued and fixed.

  The valve body 202 is disposed between the lid member 203 and the case member 201 such that the surface 252 of the main body member 251 faces the base 231 of the lid member 203 and the surface 255 faces the base 211 of the case member 201. ing. At this time, the inner peripheral lip seal 253 is disposed between the inner cylindrical portion 232 and the seat portion 233 of the lid member 203, and the outer peripheral lip seal 256 is disposed between the seat portion 214 and the outer peripheral wall portion 215 of the case member 201. Arranged between.

  Here, the axial distance between the front end position of the sheet part 214 opposite to the base 211 and the front end position of the sheet part 233 opposite to the base 231 is such that the sheet part 214 and the sheet part 233 are in the axial direction. If it is in a separated state, it is set to be narrower than the thickness of the main body member 251 or set to a distance in which the sheet portion 214 and the sheet portion 233 overlap in the axial direction. For this reason, the valve body 202 is supported by the seat member 214 on the surface 255 and on the seat portion 233 on the surface 252 in the state where it is disposed in the housing 210, and the case member 201 toward the inner peripheral side. The base portion 211 approaches the base portion 211 and is elastically deformed into a tapered shape so as to approach the base portion 231 of the lid member 203 toward the outer peripheral side.

  When the valve body 202 is placed in the housing 210 and the hydraulic pressure is not applied, the inner peripheral side lip seal 253 uses the inner peripheral portion of the inner peripheral lip portion 263 as the cylinder of the inner cylindrical portion 232 of the lid member 203. The outer peripheral portion of the outer peripheral lip portion 262 is brought into contact with the base 231 side of the taper surface 239 of the seat portion 233 of the lid member 203 with the upper margin over the entire periphery. Let In other words, in the housing 210, the inner peripheral wall portion 241 contacts the inner peripheral portion of the inner peripheral lip seal 253, the seat portion 233 contacts the outer peripheral portion of the inner peripheral lip seal 253, and the seat portion 233 is the main body member. The surface 252 of 251 can be supported.

  When the valve body 202 is placed in the housing 210 and the hydraulic pressure is not applied, the outer peripheral side lip seal 256 completely extends the outer peripheral portion of the outer peripheral lip portion 272 to the cylindrical surface 216 of the outer peripheral wall portion 215 of the case member 201. The inner peripheral portion of the inner peripheral lip portion 273 is contacted with the tightening margin all around the base portion 211 side of the notch portion 221 of the taper surface 225 of the seat portion 214. In other words, the housing 210 has an outer peripheral wall portion 215 that contacts the outer peripheral portion of the outer peripheral lip seal 256, a seat portion 214 that contacts an inner peripheral portion of the outer peripheral lip seal 256, and the seat portion 214 of the main body member 251. The surface 255 can be supported.

  In this state, the housing 210 includes the inner peripheral wall portion 241, the base portions 211 and 231, the mounting shaft portion 72 of the piston rod 41, the inner peripheral wall portion 241 in the notch 220, and the inner peripheral lip seal 253. And between the inner peripheral wall portion 241, the main body member 251, the base portion 211, and the seat portion 214, in the notch portion 221 of the seat portion 214, and between the seat portion 214, the outer peripheral side lip seal 256, and the main body member 251. A chamber 281 is formed. A chamber 282 is formed between the outer peripheral wall portion 215, the base portion 211, the seat portion 214, and the outer peripheral side lip seal 256. Further, between the outer peripheral wall 215, the outer peripheral lip seal 256, the main body member 251, the base 231 and the seat 233, in the notch 238 of the seat 233, the seat 233, the inner peripheral lip seal 253, and the main body. A chamber 283 formed between the member 251 and the member 251 is formed. A chamber 284 is formed between the inner peripheral wall portion 241, the base portion 231, the seat portion 233, and the inner peripheral lip seal 253. The chamber 283 communicates with the second chamber 32 through a passage in the through hole 240.

  The passage in the passage hole 151 of the seat member 135 shown in FIG. 2, the fixed orifice 176, the gap between the valve body 134 and the valve seat portion 161 at the time of separation, and the passage in the passage groove 147 of the passage formation member 133 are shown. The intermediate chamber 150 including the passage in the passage groove 75 of the tip rod 55, the chambers 281 to 284 shown in FIG. 3, and the passage in the through hole 240 are moved into the first chamber by the movement of the piston 30 in the extension stroke. An extension side passage 291 (second passage) from which the oil liquid flows out from 31 and flows out toward the second chamber 32 is configured.

  The passage in the through hole 240 of the lid member 203, the chambers 281 to 284, the passage in the passage groove 75 of the tip rod 55, the intermediate chamber 150 shown in FIG. 2, and the passage in the passage hole 152 of the sheet member 135 The fixed orifice 187 and the gap between the valve body 137 and the valve seat portion 162 at the time of separation are moved from the second chamber 32 to the first chamber 31 by the movement of the piston 30 in the contraction stroke. Thus, a contraction side passage 292 (second passage) from which the oil liquid flows out is formed. The passages in the passage groove 75 of the intermediate chamber 150 and the tip rod 55 are common to the passages 291 and 292.

  A damping force generation mechanism 155 including the valve body 134 and a frequency sensitive unit 200 including the valve body 202 shown in FIG. 3 are provided in the passage 291 in series. The valve body 134 of the damping force generation mechanism 155 shown in FIG. 2 provided in the passage 291 is more than the valve body 91 of the damping force generation mechanism 90 provided in the passage 108 through which the oil liquid flows out from the first chamber 31 during the extension stroke. Open the valve with a small pressure to generate a damping force. That is, the valve body 134 has lower rigidity than the valve body 91. Of the damping force generation mechanisms 90 and 155, the damping force generation mechanism 155 is a soft valve, and the damping force generation mechanism 90 is a hard valve.

  A damping force generation mechanism 156 including a valve body 137 and a frequency sensitive unit 200 including a valve body 202 shown in FIG. 3 are provided in series in the passage 292. The valve body 137 of the damping force generation mechanism 156 provided in the passage 292 opens with a pressure smaller than that of the valve body 93 of the damping force generation mechanism 92 provided in the passage 119 through which the oil liquid flows out from the second chamber 32 during the contraction stroke. Valve to generate a damping force. That is, the valve body 137 has lower rigidity than the valve body 93. Of the damping force generation mechanisms 92 and 156, the damping force generation mechanism 156 is a soft valve, and the damping force generation mechanism 92 is a hard valve.

  3 provided in the common part of the passages 291 and 292, the piston 30 moves to the first chamber 31 side shown in FIG. 2 and oil flows from the first chamber 31 toward the second chamber 32. During the extension stroke in which the liquid flows, the hydraulic pressure in the chamber 281 communicating with the first chamber 31 becomes higher than the hydraulic pressure in the chamber 283 communicating with the second chamber 32. Then, as indicated by a white arrow in FIG. 4A, the valve body 202 uses the seat portion 233 as a fulcrum so that the outer peripheral lip seal 256 is brought closer to the base portion 231 and the inner peripheral lip seal 253 is brought closer to the base portion 211. Deform. At that time, as shown by a thick solid arrow in FIG. 4A, the inner peripheral lip seal 253 is separated from the inner peripheral wall 241 by the increase of the hydraulic pressure in the chamber 281, The oil liquid is introduced from the chamber 281 to the chamber 284, and the state where the outer peripheral lip portion 262 seals the gap with the seat portion 233 by the back pressure of the chamber 284 at that time is maintained. Further, due to the increase in the hydraulic pressure in the chamber 281, the outer peripheral lip seal 256 causes the inner peripheral lip portion 273 to be separated from the seat portion 214 and introduces oil into the chamber 282. The state where the outer peripheral lip 272 seals the gap with the outer peripheral wall 215 by the back pressure of the chamber 282 is maintained. As a result, the valve body 202 has a chamber 281, 282, and 284 that are first chamber communication chambers communicating with the first chamber 31 and a chamber that is a second chamber communication chamber communicating with the second chamber 32 in the housing 210. The volume of the chamber 283 is reduced more than before the deformation while the total volume of the chambers 281, 282, and 284 is expanded as compared with that before the deformation. Thereby, the frequency sensitive part 200 can vary a damping force according to a frequency in an expansion stroke.

  Further, the frequency sensitive unit 200 moves the second chamber 32 when the piston 30 moves toward the second chamber 32 and the contraction stroke in which the oil liquid flows from the second chamber 32 toward the first chamber 31 shown in FIG. The hydraulic pressure in the chamber 283 communicating with the first chamber 31 is higher than the hydraulic pressure in the chamber 281 communicating with the first chamber 31. Then, as indicated by a white arrow in FIG. 4B, the valve body 202 uses the seat portion 214 as a fulcrum to bring the inner peripheral lip seal 253 closer to the base 211 and the outer peripheral lip seal 256 closer to the base 231. Deform. At this time, as indicated by a thick solid arrow in FIG. 4B, the inner peripheral lip seal 253 is separated from the outer peripheral lip 262 from the seat portion 233 by the increase in the hydraulic pressure in the chamber 283, and the chamber 283. Therefore, the oil liquid is introduced into the chamber 284, and the state in which the inner peripheral lip portion 263 seals the gap with the inner peripheral wall portion 241 by the back pressure of the chamber 284 at that time is maintained. Further, due to the increase in the hydraulic pressure in the chamber 283, the outer peripheral lip seal 256 causes the outer peripheral lip portion 272 to be separated from the outer peripheral wall portion 215, and the oil liquid is introduced from the chamber 283 into the chamber 282. The state in which the inner peripheral lip portion 273 seals the gap with the seat portion 214 by the back pressure of the chamber 282 is maintained. As a result, the valve body 202 has chambers 283, 282, and 284 which are second chamber communication chambers communicating with the second chamber 32 and chambers which are first chamber communication chambers communicating with the first chamber 31 in the housing 210. The volume of the chamber 281 is reduced more than before the deformation, while the total volume of the chambers 283, 282, and 284 is expanded more than before the deformation. Thereby, the frequency sensitive part 200 can vary a damping force according to a frequency also in a contraction process.

  The chamber 281 is a first chamber communication chamber that communicates with the first chamber 31, and the chamber 283 is a second chamber communication chamber that communicates with the second chamber 32. The chambers 282 and 284 serve as a first chamber communication chamber that communicates with the first chamber 31 during the expansion stroke, and serve as a second chamber communication chamber that communicates with the second chamber 32 during the contraction stroke.

  As shown in FIG. 3, a plurality of perforated disk-shaped discs 301 are provided on the side of the lid member 203 opposite to the case member 201 in the axial direction. These disks 301 have the same outer diameter, and have an outer diameter smaller than the inscribed circle of the plurality of through holes 240 in the radial direction of the lid member 203. An annular member 302 is provided on the opposite side of the disk 301 from the lid member 203. The annular member 302 has a larger outer diameter than the disk 301. A mounting shaft portion 72 is fitted to the inner peripheral portions of the disc 301 and the annular member 302. On the opposite side of the annular member 302 from the disk 301, a nut 310 is provided by being screwed to the male screw 76 of the mounting shaft portion 72.

  The annular member 186, the disk 185, the plurality of disks 184, the valve body 137, the plurality of disks 183, the sheet member 135, the plurality of disks 173, the valve body 134, the plurality of disks 174, the plurality of sheets shown in FIG. Disc 175, passage forming member 133, bottom plate portion 141 of case body 132, disc 116, discs 115, disc 114, valve body 93, discs 113, piston body 83, discs 103, valve The body 91, the disks 104 and 105, the case member 201, the lid member 203, the plurality of disks 301 and the annular member 302 shown in FIG. It is clamped in the axial direction by being sandwiched between the portion 73 and the nut 310 shown in FIG. On the other hand, the inner periphery side and the outer periphery side of the valve body 202 are not clamped in the axial direction, and are supported by seat portions 214 and 233 that are shifted in the radial direction from both axial sides. The nut 310 is a general-purpose hex nut.

  The hydraulic circuit diagram of the shock absorber 11 of the first embodiment is as shown in FIG. That is, the damping force generation mechanism 90 that is a hard valve is formed in the passage 108 that connects the first chamber 31 and the second chamber 32, and the damping force that is a hard valve is generated in the passage 119 that connects the first chamber 31 and the second chamber 32. A mechanism 92 is provided, and fixed orifices 106 and 117 are provided in the passages 108 and 119, respectively. Further, a damping force generation mechanism 155 that is a soft valve is formed in the passage 291 between the first chamber 31 and the intermediate chamber 150, and a damping force that is a soft valve is generated in the passage 292 between the first chamber 31 and the intermediate chamber 150. A mechanism 156 is provided, and fixed orifices 176 and 187 are provided in the passages 291 and 292, respectively.

  Further, the frequency sensitive unit 200 is provided between the intermediate chamber 150 and the second chamber 32. When the oil liquid flows from the first chamber 31 toward the second chamber 32 during the extension stroke, the frequency sensitive unit 200 is moved from the intermediate chamber 150 communicating with the first chamber 31 to the chambers 281 and 282 that are the first chamber communication chambers. , 284 receives the oil liquid and expands the volume of these chambers 281, 282, 284, while reducing the volume of the chamber 283 which is the second chamber communication chamber partitioned by these and the valve body 202. Thereby, the damping force is varied according to the frequency. In addition, when the oil liquid flows from the second chamber 32 toward the first chamber 31 in the contraction stroke, the frequency sensitive unit 200 oils the chambers 283, 282, and 284, which are the second chamber communication chambers, from the second chamber 32. The liquid is received and the volumes of the chambers 283, 282, and 284 are expanded, and the volume of the chamber 281 that is the first chamber communication chamber partitioned by these and the valve body 202 is reduced. Thereby, the damping force is varied according to the frequency.

  When only the damping force generating mechanism 90, which is the hard valve on the extension side shown in FIG. 2, acts in the extension stroke in which the piston rod 41 moves to the extension side, the moving speed of the piston 30 (hereinafter referred to as the piston speed). The oil fluid from the first chamber 31 flows into the second chamber 32 through the passage in the passage hole 88 and the fixed orifice 106 constituting the passage 108, and the orifice characteristic (damping force is 2 of the piston speed). Damping force is generated (which is approximately proportional to the power). For this reason, the characteristic of the damping force with respect to the piston speed is as shown by a solid line X1 in FIG. 6. In the low speed region (orifice region) on the left end side in FIG. Get higher. Further, when the piston speed increases, the oil from the first chamber 31 opens the valve body 91 of the damping force generation mechanism 90 on the extension side from the passage in the passage hole 88 that constitutes the passage 108. Between the valve seat portion 97 and the valve seat portion 97, it flows into the second chamber 32, and a damping force having a valve characteristic (the damping force is approximately proportional to the piston speed) is generated. For this reason, in the characteristic of the damping force with respect to the piston speed, the rate of increase of the damping force with respect to the increase of the piston speed is slightly lower than the low speed region (orifice region).

  In the contraction stroke in which the piston rod 41 moves to the contraction side, when only the contraction-side damping force generating mechanism 92 acts, when the piston speed is low, the oil liquid from the second chamber 32 flows into the contraction-side passage 119. A damping force having an orifice characteristic (a damping force is approximately proportional to the square of the piston speed) is generated in the first chamber 31 through the passage in the passage hole 89 and the fixed orifice 117. For this reason, the characteristic of the damping force with respect to the piston speed is as shown by the solid line X2 in FIG. 6, and in the low speed region (orifice region) on the left end side in FIG. The rate is high. Further, when the piston speed increases, the oil introduced from the second chamber 32 into the passage in the passage hole 89 constituting the contraction side passage 119 basically opens the valve body 93 and the valve seat 93. A damping force having a valve characteristic (a damping force is approximately proportional to the piston speed) is generated through the space between the portion 99 and the first chamber 31. For this reason, in the characteristic of the damping force with respect to the piston speed, the rate of increase of the damping force with respect to the increase of the piston speed is slightly lower than the low speed region (orifice region).

  The above is a case where only the damping force generating mechanisms 90 and 92 shown in FIG. 2 act, but in this embodiment, the frequency sensitive unit 200 shown in FIG. 3 corresponds to the piston frequency even when the piston speed is the same. The damping force is variable.

  In other words, in the extension stroke when the piston frequency is high, when only the damping force generation mechanism 90 acts as described above when the piston speed is low, even in the orifice region flowing through the fixed orifice 106, the first chamber 31 is introduced from the passage in the passage hole 151 into the chamber 281 of the frequency sensing unit 200 through the fixed orifice 176, the intermediate chamber 150, and the passage in the passage groove 75. In response to this, the valve body 202 is deformed so that the outer peripheral lip seal 256 is brought closer to the base 231 and the inner peripheral lip seal 253 is brought closer to the base 211 with the seat portion 233 as a fulcrum, and oil is supplied to the chambers 281, 282, 284. While introducing the liquid, the oil liquid is discharged from the chamber 283 to the second chamber 32 through the passage in the through hole 240.

  In this way, the valve body 202 is deformed and the oil liquid is introduced from the first chamber 31 into the chambers 281, 282, 284, so that the oil liquid flowing from the first chamber 31 through the passage 108 to the second chamber 32 The flow rate will decrease. For this reason, the characteristic of the damping force with respect to the piston speed is as shown by a broken line X3 in FIG. 6, and the damping force on the extension side becomes soft from the low speed region (orifice region) on the left end side in FIG. At this time, since only one surface 252 is supported by the seat portion 233 and the valve body 202 is not clamped in the axial direction, the inner peripheral lip seal 253 approaches the base 211 and the outer peripheral lip seal 256 is It is easily deformed so as to approach the base 231.

  When the piston speed increases slightly, the fluid from the first chamber 31 opens the valve body 134 of the damping force generation mechanism 155 that is a soft valve extending from the passage in the passage hole 151, and the valve body 134 and the valve seat It passes through the portion 161 and is introduced into the chambers 281, 282, and 284 of the frequency sensitive unit 200 through the intermediate chamber 150 and the passage in the passage groove 75. Also at this time, the valve body 202 is deformed and the oil liquid from the first chamber 31 is introduced into the chambers 281, 282, 284, and the oil liquid is supplied from the chamber 283 to the second chamber 32 through the passage in the through hole 240. As a result, the flow rate of the oil liquid flowing from the first chamber 31 through the passage 108 to the second chamber 32 is reduced. For this reason, the damping force on the extension side continues to be soft in the low speed region on the left end side in FIG.

  When the piston speed is further increased, the oil from the first chamber 31 is introduced into the chambers 281, 282, and 284 of the frequency sensing unit 200 by opening the valve body 134 of the damping force generation mechanism 155 that is a soft valve as described above. In addition, while opening the valve body 91 of the damping force generation mechanism 90 on the extension side from the passage in the passage hole 88 that constitutes the passage 108, the passage 108 passes between the valve body 91 and the valve seat portion 97. , Will flow into the second chamber 32. For this reason, the damping force characteristic with respect to the piston speed is soft in the extension side damping force from the middle in the left-right direction in FIG.

  In the extension stroke when the piston frequency is high, the frequency of deformation of the valve body 202 also increases and the oil liquid from the first chamber 31 is supplied to the chamber 281 of the frequency sensing unit 200 as described above each time the extension stroke is performed. 282, 284.

  On the other hand, in the expansion stroke when the piston frequency is low, the deformation frequency of the valve body 202 also follows and decreases, so that the oil liquid flows from the first chamber 31 to the chambers 281, 282, 284 at the initial stage of the expansion stroke. However, after that, the valve body 202 stops, and the oil does not flow from the first chamber 31 to the chambers 281, 282, 284 through the passage 291. As a result, the flow rate of the oil that is introduced from the first chamber 31 into the passage 108 including the passage in the passage hole 88 and passes through the damping force generation mechanism 90 and flows into the second chamber 32 is not reduced. The characteristic of the damping force is the same as that when only the damping force generation mechanism 90 acts, and the damping force on the extension side becomes hard as indicated by the solid line X1 in FIG.

  In this way, in the extension stroke, the characteristic when the piston frequency is high is the same as the characteristic when the piston frequency is high as shown by the broken line X3 in FIG. Soft from the low speed range (orifice range) to the high speed range.

  In the contraction stroke, as in the expansion stroke, the frequency sensing unit 200 shown in FIG. 3 makes the damping force variable according to the piston frequency even when the piston speed is the same. That is, in the contraction stroke when the piston frequency is high, when only the damping force generating mechanism 92 acts as described above when the piston speed is low, even in the orifice region flowing through the fixed orifice 117, the second chamber 32 is introduced from the passage in the through hole 240 into the chamber 283 of the frequency sensitive unit 200. In response to this, the valve body 202 is deformed so that the inner peripheral lip seal 253 is brought closer to the base 211 and the outer peripheral lip seal 256 is brought closer to the base 231 with the seat portion 214 as a fulcrum, and oil is supplied to the chambers 283, 282, and 284. While introducing the liquid, the oil liquid is discharged from the chamber 281 to the first chamber 31 through the passage in the passage groove 75, the intermediate chamber 150, the passage in the passage hole 152, and the fixed orifice 187.

  In this way, the valve body 202 is deformed and the oil liquid is introduced into the chambers 283, 282, and 284 from the second chamber 32, so that the oil liquid flowing from the second chamber 32 through the passage 119 to the first chamber 31 is discharged. The flow rate will decrease. For this reason, the characteristic of the damping force with respect to the piston speed is as shown by the broken line X4 in FIG. 6, and the damping force on the contraction side becomes soft from the low speed region (orifice region) on the left end side in FIG. At this time, since only one surface 255 is supported by the seat 214 in the valve body 202 and is not clamped in the axial direction, the outer peripheral lip seal 256 approaches the base 231 and the inner peripheral lip seal 253 is It is easily deformed so as to approach the base 211.

  When the piston speed is slightly increased, the valve body 202 increases the volume of the chambers 283, 282, and 284 by the oil introduced into the chamber 283 of the frequency sensing unit 200 from the second chamber 32 through the passage in the through hole 240. While expanding, the valve element 137 of the damping force generation mechanism 156 that is a soft valve on the contraction side is opened from the chamber 281 through the passage in the passage groove 75, the intermediate chamber 150, and the passage in the passage hole 152. The oil liquid is discharged into the first chamber 31 through the space between the valve seat portion 162 and the valve seat portion 137. At this time, the valve body 202 is deformed to introduce the oil liquid into the chambers 283, 282, and 284, so that the flow rate of the oil liquid flowing from the second chamber 32 through the passage 119 to the first chamber 31 is reduced. become. For this reason, the damping force on the contraction side continues to be soft in the low speed region on the left end side in FIG.

  When the piston speed is further increased, the oil liquid from the second chamber 32 is introduced into the chambers 283, 282, and 284 of the frequency sensing unit 200 as described above, and the oil liquid in the corresponding chamber 281 is a soft valve. In addition to opening the valve body 137 of the damping force generation mechanism 156 and introducing it into the first chamber 31, the valve body 93 of the damping force generation mechanism 92 on the contraction side from the passage in the passage hole 89 constituting the passage 119. The flow passes through the space between the valve body 93 and the valve seat portion 99 and flows into the first chamber 31. For this reason, the characteristic of the damping force with respect to the piston speed is such that the damping force on the contraction side is soft even in the middle to high speed range from the middle in the left-right direction in FIG.

  In the contraction stroke when the piston frequency is high, the frequency of deformation of the valve body 202 is also increased and the oil liquid from the second chamber 32 is supplied to the chamber 283 of the frequency sensing unit 200 as described above each time the compression stroke is performed. 282, 284.

  On the other hand, in the contraction stroke when the piston frequency is low, the deformation frequency of the valve body 202 also follows and decreases, so that the oil liquid flows from the second chamber 32 to the chambers 283, 282, and 284 in the initial stage of the contraction stroke. However, after that, the valve body 202 stops and the oil does not flow from the second chamber 32 to the chambers 283, 282, 284 through the passage in the through hole 240. As a result, the flow rate of the oil liquid that is introduced from the second chamber 32 into the passage 119 including the passage in the passage hole 89 and passes through the damping force generation mechanism 92 and flows into the first chamber 31 is not reduced. The characteristic of the damping force is the same as that when only the damping force generating mechanism 92 acts, and the shrinking side damping force becomes hard as indicated by the solid line X2 in FIG.

  Thus, in the contraction stroke, the characteristic when the piston frequency is high is different from the hard characteristic when the piston frequency indicated by the solid line X2 in FIG. 6 is low, as shown by the broken line X4 in FIG. Is soft throughout the entire range from the low speed range (orifice range) to the high speed range.

  Patent Document 1 described above describes a shock absorber in which a piston rod is provided with a damping force variable mechanism that varies the damping force according to the frequency. In such a shock absorber, the axial length of the shock absorber (basic length) can be reduced by making the damping force variable according to the frequency in both the expansion stroke and the contraction stroke, while shortening the axial length of the mechanism therefor. ) There is a request to shorten.

  In the shock absorber 11 of the present embodiment, the frequency sensitive portion 200 provided in the piston rod 41 is in the extension stroke in which the working fluid flows from the first chamber 31 to the second chamber 32, and the inside of the housing 210 communicates with the first chamber 31. The chambers 281, 282, and 284 are expanded while being deformed while defining the chambers 281, 282, 284 as the first chamber communication chambers and the chambers 283 as the second chamber communication chambers communicating with the second chamber 32. The chamber 283 is contracted, and the inside of the housing 210 is compressed as a second chamber communication chamber and the chambers 283, 282, and 284 as the second chamber communication chamber and the chamber as the first chamber communication chamber in the contraction process in which the working fluid flows from the second chamber 32 to the first chamber 31 Since the plate-like valve body 202 that reduces the chamber 281 while expanding the chambers 283, 282, and 284 by being deformed while being defined as 281 is provided, the damping force characteristics according to the frequency in both the expansion stroke and the contraction stroke Variable Above, it is possible to shorten the axial length. Therefore, the axial length (basic length) of the shock absorber 11 can be shortened.

  Further, valve bodies 91 and 93 for generating a damping force are provided in the passages 108 and 119 through which the oil liquid flows from one of the first chamber 31 and the second chamber 32 by the movement of the piston 30. Further, the valve body that generates damping force by opening the passages 291 and 292 through which the oil liquid flows from one of the first chamber 31 and the second chamber 32 by the movement of the piston 30 with a pressure smaller than that of the valve bodies 91 and 93. When the oil liquid flows out from one of the first chamber 31 and the second chamber 32, the housing 210 can be deformed in the housing 210 while defining the housing 210 into the first chamber 31 side and the second chamber 32 side. A frequency sensitive unit 200 having a valve body 202 is provided in series. As a result, the damping force can be varied greatly according to the frequency from the region where the piston speed is low.

  In addition, in the frequency sensitive unit 200, the valve body 202 includes a perforated disc-shaped main body member 251, an inner peripheral lip seal 253 joined to the inner peripheral side of the surface 252 of the main body member 251, and the main body member 251. The outer peripheral side lip seal 256 is joined to the outer peripheral side of the surface 255 opposite to the surface 252. Further, in the housing 210, the inner peripheral wall portion 241 contacts the inner peripheral portion of the inner peripheral lip seal 253, the seat portion 233 contacts the outer peripheral portion of the inner peripheral lip seal 253, and one surface 252 of the main body member 251. Can be supported. The housing 210 has an outer peripheral wall portion 215 that contacts the outer peripheral portion of the outer peripheral lip seal 256, a seat portion 214 that contacts the inner peripheral portion of the outer peripheral lip seal 256, and supports the other surface 255 of the main body member 251. It is possible. Thereby, the frequency sensitive part 200 can be comprised with a small number of parts.

  The embodiments described above can be considered as follows.

  The first aspect is connected to a cylinder in which a working fluid is sealed, a piston rod having one end inserted into the cylinder and the other end extending to the outside of the cylinder, and the one end of the piston rod. And a piston that is slidably fitted into the cylinder and divides the inside of the cylinder into two chambers, a first chamber on the piston rod side and a second chamber on the bottom side, and the movement of the piston causes the first chamber and A first passage and a second passage through which a working fluid flows from one of the second chambers, a first valve body provided in the first passage to generate a damping force, and provided in the second passage; An expansion stroke in which the working fluid flows from the chamber to the second chamber, and the inside of the housing is deformed while defining a first chamber communicating chamber communicating with the first chamber and a second chamber communicating chamber communicating with the second chamber. Expand the first room communication room However, the second chamber communication chamber is reduced, and the housing is deformed while defining the second chamber communication chamber and the first chamber communication chamber in the contraction process in which the working fluid flows from the second chamber to the first chamber. And a frequency sensitive part having a plate-like second valve body that expands the second chamber communication chamber and reduces the first chamber communication chamber. Thereby, the axial direction length can be shortened.

  The second mode is the first mode, wherein in the second passage, the frequency sensitive part, a third valve body that opens with a pressure smaller than the first valve body and generates a damping force, Are provided in series. As a result, the damping force can be varied greatly according to the frequency from the region where the piston speed is low.

  According to a third aspect, in the first or second aspect, the second valve body includes a perforated disk-shaped main body member and a first lip joined to an inner peripheral side of the first surface of the main body member. A seal, and a second lip seal joined to the outer peripheral side of the second surface opposite to the first surface of the main body member, and the housing is disposed on an inner peripheral portion of the first lip seal. An abutting inner peripheral wall, an abutting outer periphery of the first lip seal, a first supporting wall capable of supporting the first surface of the main body member, and an outer periphery abutting on the outer peripheral portion of the second lip seal A wall portion, and a second support wall portion that abuts on an inner peripheral portion of the second lip seal and can support the second surface of the main body member. Thereby, a frequency sensitive part can be comprised with few number of parts.

DESCRIPTION OF SYMBOLS 11 Buffer 12 Cylinder 30 Piston 31 1st chamber 32 2nd chamber 41 Piston rod 91,93 Valve body (1st valve body)
108,119 passage (first passage)
134,137 Valve body (third valve body)
200 Frequency Sensitive Unit 201 Case Member 202 Valve Body (Second Valve Body)
210 Housing 214 Seat (second support wall)
215 Outer peripheral wall portion 233 Sheet portion (first support wall portion)
241 Inner peripheral wall 251 Main body member 252 surface (first surface)
253 Inner lip seal (first lip seal)
255 side (2nd side)
256 Outer lip seal (second lip seal)
281 rooms (communication room 1)
282 rooms (first chamber communication chamber during the expansion stroke, second chamber communication chamber during the contraction stroke)
283 rooms (2nd room communication room)
284 rooms (first chamber communication chamber during the expansion stroke, second chamber communication chamber during the contraction stroke)
291,292 passage (second passage)

Claims (3)

A cylinder filled with a working fluid;
A piston rod having one end inserted into the cylinder and the other end extending outside the cylinder;
A piston connected to the one end side of the piston rod and slidably fitted in the cylinder to divide the cylinder into two chambers, a first chamber on the piston rod side and a second chamber on the bottom side; ,
A first passage and a second passage through which working fluid flows from one of the first chamber and the second chamber by the movement of the piston;
A first valve body provided in the first passage for generating a damping force;
A first chamber communicating with the first chamber and a second chamber communicating with the first chamber in an extension stroke provided in the second passage and through which the working fluid flows from the first chamber to the second chamber. The housing is formed by a contraction process in which a working fluid flows from the second chamber to the first chamber while the first chamber communicating chamber is expanded while the first chamber communicating chamber is expanded while being deformed. A frequency-sensitive device having a plate-like second valve body that is deformed while defining the inside of the second chamber communicating chamber and the first chamber communicating chamber to expand the second chamber communicating chamber and reduce the first chamber communicating chamber. And a shock absorber.   In the second passage, the frequency sensitive part and a third valve body that generates a damping force by opening with a pressure smaller than that of the first valve body are provided in series. The shock absorber according to claim 1. The second valve body is
A perforated disc-shaped body member;
A first lip seal joined to the inner peripheral side of the first surface of the main body member;
A second lip seal joined to the outer peripheral side of the second surface opposite to the first surface of the main body member;
The housing is
An inner peripheral wall portion contacting the inner peripheral portion of the first lip seal;
A first support wall that is in contact with the outer periphery of the first lip seal and can support the first surface of the body member;
An outer peripheral wall portion in contact with an outer peripheral portion of the second lip seal;
A second support wall that is in contact with the inner periphery of the second lip seal and can support the second surface of the body member;
The shock absorber according to claim 1 or 2, further comprising:

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