JP2015163801A - Shock absorber - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a shock absorber capable of obtaining excellent damping force characteristics.SOLUTION: A shock absorber includes an extension side main passage 69, a contraction side main passage 68, and an auxiliary passage 83 commonly applied to the extension side and the contraction side, each of which circulates operating fluid by sliding a piston 16. The shock absorber is configured in the following manner: an extension side main damping valve 77 is disposed in the extension side main passage 69, and a contraction side main damping valve 72 disposed in the contraction side main passage 68; inflow side check valves 35 and 50 are disposed on an upstream side in an extension stroke of the auxiliary passage 83 and on an upstream side in a contraction stroke thereof, respectively; and outflow side auxiliary damping valves 93 and 113 are disposed on a downstream side in an extension stroke of the auxiliary passage 83 and on a downstream side in a contraction stroke thereof, respectively.

Description

  The present invention relates to a shock absorber.

  The shock absorber has an expansion side passage through which the working fluid is circulated by movement of the piston during the expansion stroke, and a contraction side passage through which the working fluid is circulated by movement of the piston during the contraction stroke. Some passages are provided with a damping valve (see, for example, Patent Document 1).

JP 2011-202786 A

  In the shock absorber, it is desired to obtain a good damping force characteristic.

  Therefore, an object of the present invention is to provide a shock absorber capable of obtaining good damping force characteristics.

  In order to achieve the above object, the present invention includes an extension side main passage, a contraction side main passage, and a common sub passage on the extension side contraction side through which a working fluid is circulated by sliding of a piston. The side main passage is provided with an expansion side main damping valve, and the contraction side main passage is provided with a contraction side main damping valve, respectively, and on the upstream side in the extension stroke and the upstream side in the contraction stroke of the sub passage, An inflow side check valve is provided, and an outflow side auxiliary damping valve is provided on the downstream side in the extension stroke of the auxiliary passage and the downstream side in the contraction stroke.

  According to the present invention, good damping force characteristics can be obtained.

It is a fragmentary sectional view showing a buffer concerning a 1st embodiment of the present invention. It is a half sectional view which shows the principal part of the buffer which concerns on 1st Embodiment of this invention. It is a characteristic line figure which shows the damping force characteristic of the buffer which concerns on 1st Embodiment of this invention. It is a fragmentary sectional view showing a buffer concerning a 2nd embodiment of the present invention. It is a half sectional view which shows the principal part of the buffer which concerns on 3rd Embodiment of this invention.

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

  A shock absorber 11 according to the first embodiment shown in FIG. 1 is a hydraulic shock absorber in which an oil liquid is used as a working fluid. Specifically, the shock absorber 11 is used in a suspension device of a vehicle such as an automobile. The shock absorber 11 is arranged on a cylindrical cylinder 12 in which a working fluid is sealed, and a central axis of the cylinder 12, and one axial end (the lower end in FIG. 1) is inserted into the cylinder 12 and is not shown. The other end in the axial direction extends to the outside of the cylinder 12 and is connected to one end of the piston rod 13 on the inner side of the cylinder 12 and is slidably fitted into the cylinder 12 so that the inside of the cylinder 12 And a piston 16 that divides the chamber into two chambers 14 and 15. In addition, this invention is applicable also to the buffer which uses gas as a working fluid.

  The piston rod 13 has a cylindrical main shaft portion 21 and a substantially cylindrical mounting shaft portion 22 having a smaller diameter than that of the main shaft portion 21 at the end inserted into the cylinder 12. The mounting shaft portion 22 has a male screw 23 formed on the outer peripheral portion on the opposite side to the main shaft portion 21, and a columnar portion 24 is formed between the male screw 23 and the main shaft portion 21. The columnar portion 24 has a shape in which a cylinder is notched in a planar shape in a range from one side of the outer peripheral surface to the front of the central axis, and thus a planar shape parallel to the axial direction on one side in the radial direction. It has a shape in which a notch 25 is formed.

  The attachment shaft portion 22 has an annular base 31, a spacer 32, a laminated disk 33, a valve base 34, a laminated disk 35, a passage forming member 36, and a spacer 37, all of which form an annular shape in order from the axial main shaft portion 21 side. , Regulating member 38, spacer 39, laminated disk 40, piston 16, laminated disk 45, spacer 46, regulating member 47, spacer 48, passage forming member 49, laminated disk 50, valve base 51, laminated disk 52, spacer 53 and The sandwiching bases 54 are provided in a state where the columnar portions 24 are inserted into the respective inner peripheral sides. In this inserted state, a nut 56 is screwed onto the male screw 23 protruding from the clamping base 54. As a result, the members from the clamping base 31 to the clamping base 54 are clamped by the nut 56 between the end surface of the main shaft portion 21 on the mounting shaft portion 22 side and fastened in the axial direction.

  The piston 16 is connected to the piston rod 13 and moves integrally therewith. The piston 16 is formed in an annular shape, and a piston main body 61 through which the mounting shaft portion 22 of the piston rod 13 is inserted on the inner peripheral side thereof, and an annular belt-like shape that is attached to the outer peripheral surface of the piston main body 61 and is in sliding contact with the cylinder 12. And a sliding contact member 62. The piston body 61 is formed by connecting two divided bodies 63 and 64 divided in the axial direction. The two divided bodies 63 and 64 are positioned and connected in the circumferential direction by a positioning portion 65 that fits in an uneven shape.

  The piston main body 61 is formed with a main passage 68 and a main passage 69 that allow the chamber 14 and the chamber 15 in the cylinder 12 to communicate with each other. The main passage 68 has a chamber 14 side that opens to the inside of the piston body 61 in the radial direction, and a chamber 15 side that opens to the outside of the piston body 61 in the radial direction. The main passage 69 has a chamber 14 side that opens to the outside of the piston body 61 in the radial direction, and a chamber 15 side that opens to the inside of the piston body 61 in the radial direction. Although not shown, the main passage 68 and the main passage 69 are alternately formed in a plurality of locations in the circumferential direction of the piston main body 61. The piston main body 61 is provided with the laminated disk 40 on the axial chamber 14 side so that the main passage 68 can be opened and closed, and on the axial chamber 15 side, the main passage 69 can be opened and closed. The laminated disk 45 is disposed.

  In the contraction stroke in which the piston rod 13 moves to the contraction side (lower side in FIG. 1) that increases the amount of entry into the cylinder 12, the piston 16 that moves integrally with the piston rod 13 slides in the cylinder 12 and moves into the chamber. The volume of 14 is increased and the volume of chamber 15 is decreased. At this time, the working fluid in the chamber 15 is restricted from flowing through the main passage 69 by the laminated disk 45, flows through the main passage 68, opens the laminated disk 40, and is discharged into the chamber 14. That is, the main passage 68 is a contraction-side main passage 68 through which the working fluid flows from the chamber 15 to the chamber 14 by the sliding of the piston 16 in the contraction stroke.

  The laminated disk 40 that opens and closes the contraction-side main passage 68 in the contraction stroke, and the valve seat 71 on the side of the lamination disk 40 in the axial direction of the piston body 61 that is seated when the lamination disk 40 closes the contraction-side main passage 68. However, a compression-side main damping valve 72 is provided in the compression-side main passage 68 to open and close the compression-side main passage 68. The contraction-side main damping valve 72 adjusts the flow rate of the working fluid flowing through the contraction-side main passage 68 and flowing from the chamber 15 to the chamber 14 in the contraction stroke in which the piston rod 13 moves to the contraction side by the laminated disk 40, and thereby the damping force Is generated. As shown in FIG. 2, the laminated disc 40 is configured by laminating two deformable discs 73 and 74, and the valve seat 71 in the disc 73 disposed on the piston 16 side in the axial direction among them. Sit on.

  In the extension stroke in which the piston rod 13 moves to the extension side (the upper side in FIG. 2) that increases the amount of protrusion from the cylinder 12, the piston 16 that moves integrally with the piston rod 13 slides in the cylinder 12 and moves into the chamber 15. The volume is increased and the volume of the chamber 14 is decreased. At this time, the working fluid in the chamber 14 is restricted from flowing in the contraction-side main passage 68 by the laminated disk 40, flows in the main passage 69 shown in FIG. 1, opens the laminated disk 45, and is discharged into the chamber 15. That is, the main passage 69 is an extension-side main passage 69 through which the working fluid flows from the chamber 14 to the chamber 15 by the sliding of the piston 16 in the extension stroke.

  A laminated disk 45 that opens and closes the extension-side main passage 69 during the extension stroke, and a valve seat 76 on the side of the lamination disk 45 in the axial direction of the piston body 61 that is seated when the lamination disk 45 closes the extension-side main passage 69. However, it constitutes an extension-side main damping valve 77 that is provided in the extension-side main passage 69 and opens and closes it. The extension-side main damping valve 77 adjusts the flow rate of the working fluid flowing through the extension-side main passage 69 and flowing from the chamber 14 to the chamber 15 when the piston rod 13 moves to the extension side by the laminated disk 45, thereby reducing the damping force. generate. As shown in FIG. 2, the laminated disc 45 is configured by laminating four deformable discs 78, 79, 80, 81, and is seated on the valve seat 76 on the disc 78. The disks 78 and 79 are common parts with the disks 73 and 74, the disk 80 has a smaller outer diameter than these, and the disk 81 has a smaller outer diameter than the disk 80.

  As described above, the notch 25 is formed in the columnar portion 24 of the piston rod 13, and by this notch 25, the columnar portion 24, the sandwiching base 31, the spacer 32, the laminated disk 33, the valve base 34, the laminated Disc 35, passage forming member 36, spacer 37, regulating member 38, spacer 39, laminated disc 40, piston 16, laminated disc 45, spacer 46, regulating member 47, spacer 48, passage forming member 49, laminated disc 50, valve base 51, an internal passage 82 extending in the axial direction is formed between the laminated disk 52, the spacer 53, and the sandwiching base 54. The internal passage 82 is provided separately from the contraction-side main passage 68 and the extension-side main passage 69, and constitutes an intermediate portion of the sub-passage 83 that allows the working fluid to circulate in common on the extension-side contraction side by sliding of the piston 16. doing. The nut 56 shown in FIG. 1 is a cap nut, and restricts the passage of the auxiliary passage 83 to the chamber 15 through the gap between the piston rod 13 and the nut 56.

  The sandwiching base 31 is highly rigid and difficult to deform. The spacer 32 has a smaller outer diameter and a smaller thickness than the sandwiching base 31.

  As shown in FIG. 2, the laminated disk 33 is formed by laminating a plurality of, specifically four, deformable disks 84, 85, 86, 87 in this order from the side of the spacer 32 in the axial direction. ing. The three disks 84 to 86 from the spacer 32 side have the same outer diameter, and the outer diameter is larger than that of the spacer 32. The outermost diameter of the disk 87 on the side opposite to the spacer 32 is smaller than that of the disks 84 to 86 and larger than that of the spacer 32.

  The disk 84 is in contact with the spacer 32, and a passage hole 84 a is formed penetrating in the thickness direction at a radially outer position than the spacer 32. The disk 85 is in contact with the disk 84, and is formed with a passage hole 85a extending inward in the radial direction of the disk 85 while communicating with the passage hole 84a. The disk 86 is in contact with the disk 85, and a passage hole 86a communicating with the radially inner portion of the disk 85 of the passage hole 85a is formed through the thickness direction. The disk 87 is in contact with the disk 86 and the valve base 34, and a passage hole 87a communicating with the passage hole 86a is formed through the thickness direction. The passage hole 87a also penetrates the disk 87 in the radial direction. Thereby, the laminated disk 33 always makes the chamber 14 and the internal passage 82 communicate with each other through the passage holes 84a, 85a, 86a, 87a. The passage holes 84a, 85a, 86a, 87a constitute a fixed restricting portion 89 that allows the chamber 14 and the internal passage 82 to communicate with each other at all times. The fixed restricting portion 89 constitutes a part of the end side of the sub passage 83.

  The valve base 34 is rigid and difficult to deform. The valve base 34 is in contact with the disk 87 on the side of the laminated disk 33 in the axial direction and on the inner diameter side, and the disk 86 is seated on the valve seat 91 on the side of the laminated disk 33 in the axial direction and on the outer diameter side. The valve base 34 defines a valve chamber 92 between the valve base 34 and the disc 86 in a state where the disc 86 is seated on the valve seat portion 91. The valve chamber 92 is always connected to the internal passage 82 through the passage hole 87a. Communicate. The valve chamber 92 constitutes a part of the end side of the sub passage 83.

  When the piston 16 increases the volume of the chamber 14 and decreases the volume of the chamber 15 in the contraction stroke, the working fluid in the chamber 15 flows toward the chamber 14 through the sub-passage 83 as will be described later. 82 passes through the fixed restricting portion 89 or in addition to this, passes through the valve chamber 92, and the discs 84 to 86 of the laminated disc 33 are separated from the valve seat portion 91 and discharged to the chamber 14. Therefore, the laminated disk 33 and the valve seat portion 91 constitute an outflow side auxiliary damping valve 93 that is provided on the downstream side in the contraction stroke of the auxiliary passage 83 and opens and closes the auxiliary passage 83.

  The laminated disk 35 is configured by laminating a plurality of, specifically, two deformable disks 95 and 96. The disk 95 disposed on the valve base 34 side in the axial direction has a smaller outer diameter than the disk 96 disposed on the side opposite to the valve base 34. The disk 95 comes into contact with the axially laminated disk 35 side and the inner diameter side of the valve base 34, and the disk 96 is placed on the axially laminated disk 35 side and outer diameter side valve seat 97 of the valve base 34. Sit down. The valve base 34 defines a valve chamber 98 with the disc 96 in a state where the disc 96 is seated on the valve seat portion 97, and the valve chamber 98 is a passage formed on the inner diameter side of the disc 95. It always communicates with the internal passage 82 through the hole 95a. The inside of the passage hole 95 a of the disk 95 is a throttle portion 100. The throttle portion 100 and the valve chamber 98 constitute a part of the end side of the sub passage 83.

  When the piston 16 increases the volume of the chamber 14 and decreases the volume of the chamber 15 in the contraction stroke, the working fluid in the chamber 15 flows toward the chamber 14 through the auxiliary passage 83 as will be described later. This working fluid passes through the valve chamber 98 from the throttle portion 100, and the disc 96 of the laminated disc 35 is separated from the valve seat portion 97 and discharged to the chamber 14. That is, the laminated disk 35 and the valve seat 97 constitute the third damping valve 101 on the outflow side that is provided on the downstream side in the contraction stroke of the sub passage 83 and opens and closes the sub passage 83. A passage hole 96 a that is opened and closed by the disc 95 is formed in the disc 96 of the laminated disc 35.

  The passage forming member 36 has high rigidity and is difficult to deform. The passage forming member 36 is provided with a passage hole 36a through which the passage hole 96a communicates with the chamber 14 at all times in the axial direction. When the piston 16 increases the volume of the chamber 15 and decreases the volume of the chamber 14 in the expansion stroke, the working fluid in the chamber 14 passes through the passage hole 36a and the passage hole 96a, and separates the disk 95 of the laminated disk 35 from the disk 96. . Then, the working fluid in the chamber 14 flows into the valve chamber 98, passes through the throttle portion 100, flows through the internal passage 82, and flows toward the chamber 15. The laminated disk 35 permits the flow of the working fluid from the chamber 14 through the passage hole 36 a and the passage hole 96 a to the valve chamber 98 and through the throttle unit 100 to the internal passage 82 by separating the disk 95 from the disk 96. On the other hand, the check valve for restricting the flow of the working fluid flowing from the internal passage 82 through the throttle portion 100 to the chamber 14 from the valve chamber 98 through the passage hole 96a and the passage hole 36a by contacting the disk 95 with the disk 96. Is configured. That is, the laminated disk 35 constitutes an inflow side check valve provided on the upstream side in the extension stroke of the sub-passage 83, and the outflow side in the contraction stroke which is the opposite stroke to the upstream extension stroke. A third damping valve 101 is configured. The throttle unit 100 is provided on the laminated disk 35 side in the sub passage 83.

  The spacer 37 is rigid and difficult to deform, has an outer diameter smaller than that of the passage forming member 36, and is provided inside the radial passage hole 36 a of the passage forming member 36. The regulating member 38 is rigid and difficult to deform, and has an outer diameter that is the same as the outer diameter of the laminated disk 40. The spacer 39 is rigid and difficult to deform, and has an outer diameter smaller than the outer diameter of the laminated disk 40. The spacer 37 and the spacer 39 are common parts. The restricting member 38 restricts the deformation of the laminated disk 40 in the direction away from the piston 16 by bringing the disk 74 into contact.

  The clamping base 54 is rigid and difficult to deform, and is a common component with the clamping base 31. The spacer 53 has a smaller outer diameter and a smaller thickness than the sandwiching base 54, and is a common component with the spacer 32.

  The laminated disk 52 is configured by laminating a plurality of, specifically, four, deformable disks 104, 105, 106, and 107 in this order from the spacer 53 side in the axial direction. The three disks 104 to 106 from the spacer 53 side have the same outer diameter, and the outer diameter is larger than that of the spacer 53. The outermost diameter of the disk 107 opposite to the spacer 53 is smaller than the disks 104 to 106 and larger than the spacer 53.

  The disk 104 is in contact with the spacer 53, and a passage hole 104 a is formed penetrating in the thickness direction at an outer position in the radial direction than the spacer 53. The disk 104 is a common component with the disk 84. The disk 105 is in contact with the disk 104, and a passage hole 105a extending inward in the radial direction of the disk 105 while being communicated with the passage hole 104a is formed through the thickness direction. The disk 105 is a common component with the disk 85. The disk 106 is in contact with the disk 105, and a passage hole 106a that communicates with a radially inner portion of the disk 105 of the passage hole 105a is formed so as to penetrate in the thickness direction. The disk 106 is a common component with the disk 86. The disc 107 is in contact with the disc 106 and the valve base 51, and a passage hole 107a communicating with the passage hole 106a is formed through the thickness direction. The passage hole 107a also penetrates the disk 107 in the radial direction. The disk 107 is a common component with the disk 87. The laminated disk 52 always communicates the chamber 15 with the internal passage 82 through passage holes 104a, 105a, 106a, and 107a, and the passage holes 104a, 105a, 106a, and 107a always connect the chamber 15 and the internal passage 82 with each other. A fixed throttle portion 109 that communicates is configured. The fixed restrictor 109 constitutes a part of the end side of the sub passage 83.

  The valve base 51 is rigid and difficult to deform, and is a common component with the valve base 34. The valve base 51 is in contact with the disk 107 on the side of the laminated disk 52 in the axial direction and on the inner diameter side, and the disk 106 is seated on the valve seat 111 on the side of the laminated disk 52 in the axial direction and on the outer diameter side. The valve base 51 defines a valve chamber 112 between the valve base 51 and the disc 106 in a state where the disc 106 is seated on the valve seat portion 111. The valve chamber 112 is always connected to the internal passage 82 through the passage hole 107a. Communicate. The valve chamber 112 constitutes a part of the end side of the sub passage 83.

  When the piston 16 increases the volume of the chamber 15 and decreases the volume of the chamber 14 in the extension stroke, the working fluid in the chamber 14 passes through the passage hole 36a and the passage hole 96a, and passes through the disk 95 of the laminated disk 35 as a check valve. It flows away from 96 and flows to the chamber 15 side through the valve chamber 98, the throttle portion 100 and the internal passage 82. Then, the working fluid passes from the internal passage 82 through the fixed throttle 109 or in addition to the valve chamber 112, and separates the disks 104 to 106 of the laminated disk 52 from the valve seat 111 to the chamber 15. Discharged. That is, the laminated disk 52 and the valve seat portion 111 constitute an outflow side auxiliary damping valve 113 that is provided on the downstream side in the extension stroke of the auxiliary passage 83 and opens and closes the auxiliary passage 83.

  The laminated disk 50 is configured by laminating a plurality of, specifically two, deformable disks 115 and 116. The disk 115 arranged on the valve base 51 side in the axial direction has a smaller outer diameter than the disk 116 arranged on the side opposite to the valve base 51. The disk 115 comes into contact with the axially laminated disk 50 side and the inner diameter side of the valve base 51, and the disk 116 contacts the laminated disk 50 side and outer diameter side valve seat 117 of the valve base 51. Sit down. The valve base 51 defines a valve chamber 118 between the valve base 51 and the disc 116 in a state where the disc 116 is seated on the valve seat portion 117, and the valve chamber 118 is a passage hole formed on the inner diameter side of the disc 115. It always communicates with the internal passage 82 via 115a. The inside of the passage hole 115 a of the disk 115 is a throttle portion 120. The throttle portion 120 and the valve chamber 118 constitute a part of the end side of the sub passage 83.

  When the piston 16 increases the volume of the chamber 15 and decreases the volume of the chamber 14 in the extension stroke, the working fluid in the chamber 14 opens the laminated disk 35 as a check valve, and opens the valve chamber 98, the throttle unit 100, and the internal passage 82. It will flow to the chamber 15 side. This working fluid passes through the valve chamber 118 from the throttle portion 120, causes the disc 116 of the laminated disc 50 to be separated from the valve seat portion 117, and is discharged into the chamber 15. That is, the laminated disk 50 and the valve seat portion 117 constitute an outflow side third damping valve 121 that is provided on the downstream side in the extension stroke of the sub passage 83 and opens and closes the sub passage 83. A passage hole 116 a that is opened and closed by the disc 115 is formed in the disc 116 of the laminated disc 50. The disk 115 is a common part with the disk 95, and the disk 116 is a common part with the disk 96.

  The passage forming member 49 has high rigidity and is difficult to deform. The passage forming member 49 is provided with a passage hole 49a that allows the passage hole 116a to always communicate with the chamber 15 in the axial direction. When the piston 16 increases the volume of the chamber 14 and decreases the volume of the chamber 15 in the contraction stroke, the working fluid in the chamber 15 passes through the passage hole 49a and the passage hole 116a and separates the disk 115 of the laminated disk 50 from the disk 116. . Then, the working fluid in the chamber 15 flows into the valve chamber 118, passes through the throttle portion 120, and flows to the chamber 14 side through the internal passage 82. The laminated disk 50 permits the flow of the working fluid from the chamber 15 through the passage hole 49a and the passage hole 116a to the valve chamber 118 and through the throttle 120 to the internal passage 82 by separating the disk 115 from the disk 116. On the other hand, the check valve for regulating the flow of the working fluid flowing from the internal passage 82 through the throttle 120 to the chamber 15 from the valve chamber 118 through the passage hole 116a and the passage hole 49a by bringing the disk 115 into contact with the disk 116. Is configured. That is, the laminated disk 50 constitutes an inflow side check valve provided on the upstream side in the contraction stroke of the sub-passage 83, and the outflow side in the extension stroke, which is the opposite stroke to the upstream contraction stroke. A third damping valve 121 is configured. The throttle unit 120 is provided on the side of the laminated disk 50 in the sub passage 83.

  The spacer 48 is rigid and difficult to deform, has an outer diameter smaller than the passage forming member 49, and is provided inside the radial passage hole 49 a of the passage forming member 49. The regulating member 47 is rigid and difficult to deform, and has an outer diameter that is the same as the outer diameter of the laminated disk 45. The spacer 46 is rigid and difficult to deform, and has an outer diameter smaller than the outer diameter of the disk 81 of the laminated disk 45 and the regulating member 47. The spacer 46 is a common component with the spacers 32 and 53. The spacer 48 is a common part with the spacers 37 and 39. The restricting member 47 restricts the deformation of the laminated disk 45 in the direction away from the piston 16 by contacting any of the disks 79 to 81.

  Regarding the operation of the shock absorber 11 of the first embodiment, first, the operation of the contraction process and the generated damping force characteristics will be described.

  In the contraction stroke, the piston 16 increases the volume of the chamber 14 and decreases the volume of the chamber 15. In the very low speed range where the piston speed is low, i.e., 0 or more and less than v1 in FIG. The disc 115 of the laminated disc 50 as a check valve on the inflow side of the disc is separated from the disc 116. Then, the working fluid in the chamber 15 flows into the valve chamber 118, passes through the throttle portion 120, and flows to the chamber 14 side through the internal passage 82. When the piston speed is low at a very low speed range of 0 or more and less than v1, the working fluid flowing to the chamber 14 side through the internal passage 82 is discharged to the chamber 14 through the fixed throttle portion 89 formed in the laminated disk 33. In the very low speed range of 0 or more and less than v1, the damping force characteristic is such that the increasing rate of the damping force with respect to the unit increase change of the piston speed is high.

  In the low speed range in which the piston speed indicated by v1 or more and less than v2 in FIG. 3 is faster than the above-described very low speed range, the working fluid that flows to the chamber 14 side through the internal passage 82 in the same manner as described above, The disks 84 to 86 of the disk 33 are deformed and separated from the valve seat portion 91 of the valve base 34 and discharged from the valve chamber 92 to the chamber 14 to change the damping force characteristics. That is, the sub damping valve 93 on the downstream side and the outflow side in the contraction stroke of the sub passage 83 is opened. Then, the damping force characteristic determined by the throttle unit 120 is obtained, and the damping force characteristic is lower than the damping force increase rate with respect to the unit increase change of the piston speed in the very low speed range of 0 or more and less than v1. The sub damping valve 93 determines the piston speed v1 for switching the damping force characteristic.

  In the medium speed range where the piston speed indicated by v2 or more and less than v3 in FIG. 3 is faster than the low speed range v1 or more and less than v2, the working fluid flowing to the chamber 14 side through the internal passage 82 is added to the above in the same manner as above. Further, the disc 96 of the laminated disc 35 is separated from the valve seat portion 97 of the valve base 34 and discharged from the valve chamber 98 to the chamber 14 to change the damping force characteristic. That is, the third damping valve 101 on the downstream side and the outflow side in the contraction stroke of the sub passage 83 is opened. In the middle speed region v2 or more and less than v3, the damping force characteristic is lower in the rate of increase than the damping force increase rate with respect to the unit increase change of the piston speed in the low speed region v1 or more and less than v2.

  In the high speed range where the piston speed indicated by v3 or higher in FIG. 4 is higher than the medium speed range v2 or higher and lower than v3, the operation from the chamber 15 is performed in addition to the working fluid flowing through the internal passage 82 to the chamber 14 side. The fluid flows through the contraction side main passage 68, separates the laminated disk 40 from the valve seat 71, and is discharged from the contraction side main passage 68 to the chamber 14. That is, the contraction side main damping valve 72 is opened. In the high speed region v3 or higher, the damping force characteristic has a lower increase rate than the increase rate of the damping force with respect to the unit increase change of the piston speed in the middle speed region v2 or higher and lower than v3.

  Next, the operation of the extension stroke and the generated damping force characteristics will be described.

  In the extension stroke, the piston 16 increases the volume of the chamber 15 and decreases the volume of the chamber 14. In a very low speed region where the piston speed is low, the working fluid in the chamber 14 passes through the passage hole 36a of the passage forming member 36 and the passage hole 96a of the disc 96 of the laminated disc 35, and is stacked as a check valve on the inflow side in the extension stroke. The disk 95 of the disk 35 is separated from the disk 96. Then, the working fluid in the chamber 14 flows into the valve chamber 98, passes through the throttle portion 100, flows through the internal passage 82, and flows toward the chamber 15. In this very low speed region where the piston speed is low, the working fluid flowing to the chamber 15 side through the internal passage 82 is discharged to the chamber 15 via the fixed restricting portion 109 formed in the laminated disk 52. In this very low speed range, the damping force characteristic is such that the rate of increase of the damping force with respect to the unit increase change of the piston speed is high.

  In the low speed range where the piston speed is faster than the above-described very low speed range, the working fluid flowing to the chamber 15 side through the internal passage 82 in the same manner as described above deforms the disks 104 to 106 of the laminated disk 52 in addition to the above. The valve base 51 is separated from the valve seat portion 111 and discharged from the valve chamber 112 to the chamber 15 to change the damping force characteristic. That is, the sub damping valve 113 on the downstream side and the outflow side in the extension stroke of the sub passage 83 is opened. Then, the damping force characteristic determined by the throttle unit 100 is obtained, and the damping force characteristic is lower in the rate of increase than the rate of increase of the damping force with respect to the unit increase change of the piston speed in the very low speed range. The sub damping valve 113 determines the piston speed for switching the damping force characteristic from the very low speed range to the low speed range.

  In the medium speed range where the piston speed is higher than the low speed range described above, the working fluid flowing to the chamber 15 side through the internal passage 82 in the same manner as described above further causes the disk 116 of the laminated disk 50 to move to the valve base. The valve 51 is separated from the valve seat 117 and discharged from the valve chamber 118 to the chamber 15 to change the damping force characteristic. That is, the third damping valve 121 on the downstream side and the outflow side in the extension stroke of the sub passage 83 is opened. In the middle speed range, the damping force characteristic has a lower rate of increase than the rate of increase of the damping force with respect to the unit increase change of the piston speed in the low speed range.

  In the high speed range where the piston speed is higher than the above-described medium speed range, in addition to the working fluid flowing to the chamber 15 side through the internal passage 82 described above, the working fluid from the chamber 14 is expanded side main passage shown in FIG. When the laminated disk 45 is separated from the valve seat portion 76 through the flow at 69, it is discharged from the extension side main passage 69 to the chamber 15. That is, the expansion side main damping valve 77 is opened and flows into the chamber 15. In this high speed region, the damping force characteristic has a lower rate of increase than the rate of increase of the damping force with respect to the unit increase change of the piston speed in the medium speed region.

  As described above, according to the shock absorber 11 according to the first embodiment, the expansion side main passage 69 provided with the expansion side main damping valve 77 and the contraction side main passage provided with the contraction side main damping valve 72. A passage 68 and a sub-passage 83 for expansion and contraction are provided independently. The laminated disk 35 constituting the inflow side check valve is provided on the upstream side in the extension stroke of the sub passage 83, and the outflow side sub damping valve 113 is provided on the downstream side in the extension stroke of the sub passage 83. A laminated disk 50 constituting an inflow check valve is provided on the upstream side of the sub-passage 83 in the contraction stroke, and an outflow-side sub damping valve 93 is provided on the downstream side of the sub-passage 83 in the contraction stroke. Thereby, the damping force characteristic can be set independently in the extension stroke and the contraction stroke, the characteristic of the extension side auxiliary damping valve 113 can be set independently of the extension side main damping valve 77, and The characteristics of the compression-side sub damping valve 93 can be set independently of the compression-side main damping valve 72.

  As a result, for example, mechanical friction between the piston 16 starting movement of the shock absorber 11 and the cylinder 12 of the piston rod 13 and a rod seal (not shown) of the piston rod 13 is changed from static friction to dynamic friction. In the very low speed region where the pressure is switched to, a characteristic is shown in which a working fluid is caused to flow by the fixed throttle portions 89 and 119 to increase the damping force with respect to the piston speed and immediately increase the damping force (see 0 or more and less than v1 in FIG. 3). The sub damping valves 93 and 113 are opened when the speed is slightly increased, and the third damping valves 101 and 121 are opened when the speed is further increased. It is possible to gradually reduce the rate of increase so as not to impair the riding comfort and to set damping force characteristics with few discontinuities.

  Moreover, the laminated disk 35 constituting the inflow side check valve is provided on the upstream side in the extension stroke of the sub-passage 83, and the laminated disk 50 constituting the inflow side check valve is provided on the upstream side in the contraction stroke of the sub-passage 83. By providing, the sub-passage 83 can be expanded and contracted.

  Further, the laminated disk 35 as an inflow side check valve provided on the upstream side in the extension stroke of the sub-passage 83 is the third damping valve on the outflow side in the contraction stroke opposite to the extension stroke on the upstream side. 101, and a laminated disk 50 as an inflow check valve provided on the upstream side in the contraction stroke of the sub-passage 83 is provided on the outflow side in the extension stroke opposite to the contraction stroke on the upstream side. A third damping valve 121 is configured. For this reason, it is possible to set damping force characteristics with fewer discontinuities while suppressing an increase in the number of parts.

  A throttle portion 100 is provided on the side of the laminated disk 35 as the check valve on the inflow side in the expansion stroke of the sub-passage 83, and the side of the lamination disk 50 as the check valve on the inflow side in the contraction stroke of the sub-passage 83 is provided. Is provided with a diaphragm 120. For this reason, the flow of the working fluid into the sub-passage 83 in a state where the laminated disk 35 as the inflow side check valve in the expansion stroke is opened is restricted by the throttle portion 100, and as the inflow side check valve in the contraction stroke The throttle portion 120 can restrict the flow of the working fluid into the sub-passage 83 with the laminated disk 50 opened. Therefore, the characteristics after opening of the auxiliary damping valves 93 and 113 can be set by the throttle portions 100 and 120.

“Second Embodiment”
A shock absorber according to a second embodiment of the present invention will be described with reference to FIG. 4 focusing on the differences from the first embodiment. In addition, about the site | part which is common in 1st Embodiment, it represents with the same name and the same code | symbol.

  In the second embodiment, the notch portion 25 of the first embodiment is not formed in the columnar portion 24 of the piston rod 13, and from the end on the axial male screw 23 side to the center of the mounting shaft portion 22 of the piston rod 13. A passage hole 201 is formed. A female screw 202 is formed at the opening end on the chamber 15 side in the passage hole 201, and the chamber 15 side of the passage hole 201 is closed by a bolt 203 screwed into the female screw 202. A passage hole 205 along the radial direction of the columnar portion 24 is formed in the vicinity of the end of the passage hole 201 opposite to the female screw 202, and the diameter of the columnar portion 24 is also at an intermediate position of the passage hole 201 on the female screw 202 side. A passage hole 206 is formed along the direction. In addition, the columnar portion 24 is formed with a notch 207 cut out in a planar shape from the outer peripheral surface at the position of the passage hole 205, and a notch 208 cut out in a flat shape from the outer peripheral surface is formed in the passage hole. It is formed at the position 206.

  Similar to the first embodiment, members from the clamping base 31 to the clamping base 54 are mounted on the mounting shaft portion 22, and in this state, a nut 215 is screwed onto the male screw 23 protruding from the clamping base 54. Thereby, the members from the clamping base 31 to the clamping base 54 are clamped between the end surface of the main shaft portion 21 on the mounting shaft portion 22 side and the nut 215 and fastened in the axial direction. The nut 215 is not a cap nut but a normal nut.

  The notch 207 overlaps the clamping base 31, the spacer 32, the laminated disk 33 and the valve base 34 in the axial direction, and forms a passage 209 therebetween. The passage 209 is always in communication with the fixed throttle portion 89 and the throttle portion 100. The notch 208 overlaps the passage forming member 49, the laminated disk 50, the valve base 51, the laminated disk 52, and the spacer 53 in the axial direction, and forms a passage 210 therebetween. The passage 210 is always in communication with the fixed throttle unit 109 and the throttle unit 120.

  The passage holes 201, 205, and 206 and the passages 209 and 210 constitute an internal passage 211 that constitutes an intermediate portion of the common sub-passage 83 on the expansion side contraction side, like the internal passage 82 of the first embodiment. ing.

  Such 2nd Embodiment also operate | moves similarly to 1st Embodiment.

“Third Embodiment”
A shock absorber according to a third embodiment of the present invention will be described with reference to FIG. 5 with a focus on differences from the first embodiment. In addition, about the site | part which is common in 1st Embodiment, it represents with the same name and the same code | symbol.

  In the third embodiment, the clamping base 31, the spacer 32, the passage forming member 36, the laminated disk 35, the valve base 34, the laminated disk 33, the spacer 301, the spacer 37, and the regulating member 38 are attached to the mounting shaft portion 22 of the piston rod 13. , Spacer 39, laminated disk 40, piston 16, laminated disk 45, spacer 46, regulating member 47, spacer 48, spacer 302, laminated disk 52, valve base 51, laminated disk 50, passage forming member 49, spacer 53 and clamping base 54 are attached in this order.

  Here, each of the laminated disk 35, the valve base 34, the laminated disk 33, the laminated disk 52, the valve base 51, and the laminated disk 50 is reversed in the axial direction from the first embodiment. Therefore, the laminated disk 35 is provided with a disk 96 on the holding base 31 side in the axial direction and a disk 95 on the opposite side to the holding base 31. Further, the valve base 34 has a valve seat 97 disposed on the side of the clamping base 31 in the axial direction, and a valve seat 91 disposed on the side opposite to the clamping base 31. In addition, the laminated disk 33 is provided with a disk 87, a disk 86, a disk 85, and a disk 84 in this order from the holding base 31 side in the axial direction. In addition, the stacked disk 52 includes a disk 107, a disk 106, a disk 105, and a disk 104 in order from the side opposite to the clamping base 31 in the axial direction. In the valve base 51, the valve seat portion 111 is disposed on the side of the clamping base 31 in the axial direction, and the valve seat portion 117 is disposed on the side opposite to the clamping base 31. In the laminated disk 50, the disk 115 is disposed on the side of the sandwiching base 31 in the axial direction, and the disk 116 is disposed on the side opposite to the sandwiching base 31. That is, in the third embodiment, the entire combination of the laminated disk 33, the valve base 34, the laminated disk 35, and the passage forming member 36 of the first embodiment is reversed in the axial direction, and the passage forming member 49 of the first embodiment is laminated. The entire combination of the disk 50, the valve base 51 and the laminated disk 52 is inverted in the axial direction.

  Such 3rd Embodiment also operate | moves similarly to 1st Embodiment.

  In the first to third embodiments, the laminated disk 35 provided on the upstream side in the extension stroke of the sub-passage 83 constitutes the check valve on the inflow side and in the contraction stroke opposite to the stroke on the upstream side. In addition to constituting the third damping valve 101 on the outflow side, the laminated disk 50 provided on the upstream side in the contraction stroke constitutes the check valve on the inflow side and has an extension stroke opposite to the upstream stroke. In the above description, the third damping valve 121 on the outflow side is configured as an example. However, it is sufficient that at least one of the laminated disks 35 and 50 has the above configuration.

  In the first to third embodiments, the throttle portion 100 is provided on the laminated disk 35 side which is the check valve on the inflow side in the extension stroke of the sub-passage 83, and the check valve on the inflow side in the contraction stroke of the sub-passage 83 is provided. The diaphragm 120 is provided on the laminated disk 50 side. However, it is sufficient that at least one of the diaphragms 100 and 120 is provided.

  The embodiment described above includes a cylinder in which a working fluid is sealed, a piston that is slidably fitted in the cylinder and divides the cylinder into two chambers, one end connected to the piston, and the like. A piston rod whose end extends to the outside of the cylinder, and an extension-side main passage, a contraction-side main passage, and a sub-passage common to the extension-side contraction side that allow the working fluid to flow by sliding of the piston, respectively. The expansion-side main passage is provided with an expansion-side main damping valve, and the compression-side main passage is provided with a compression-side main damping valve, respectively, and an upstream side in the extension stroke of the sub-passage and An upstream check valve is provided with an inflow check valve, and a downstream discharge valve is provided with an extension side of the sub-passage, and a downstream sub damping valve is provided with a downstream side of the contraction stroke. It is characterized by being . Thereby, the damping force characteristic can be set independently in the extension stroke and the contraction stroke, and the characteristic of the extension side auxiliary damping valve can be set independently of the extension side main damping valve. The characteristics of the secondary damping valve on the contraction side can be set independently of the main damping valve. In addition, an inflow check valve is provided on the upstream side in the extension stroke of the sub-passage, and an inflow check valve is provided on the upstream side in the contraction stroke of the sub-passage, so that the sub-passage can be expanded and contracted. it can.

  Further, the check valve on the inflow side provided on at least one of the upstream side in the extension stroke of the sub-passage and the upstream side in the contraction stroke is configured by a laminated disk, and the laminated disk is connected to the upstream side. The third damping valve on the outflow side in the stroke opposite to the above stroke is configured. As a result, it is possible to set damping force characteristics with fewer discontinuities while suppressing an increase in the number of parts.

  In addition, a throttling portion is provided on at least one of the sub passages on the check valve side. The characteristics of the auxiliary damping valve after opening can be set by these throttle portions.

11 Shock absorber 12 Cylinder 13 Piston rod 14, 15 Chamber 16 Piston 35, 50 Laminated disc (check valve)
68 Contraction side main passage 69 Extension side main passage 72 Contraction side main damping valve 77 Extension side main damping valve 83 Sub passage 93, 113 Sub damping valve 100, 120 Restriction portion 101, 121 Third damping valve

Claims (3)

A cylinder filled with a working fluid;
A piston that is slidably fitted in the cylinder and divides the cylinder into two chambers;
A piston rod having one end connected to the piston and the other end extending to the outside of the cylinder;
An extension-side main passage, a contraction-side main passage, and a sub-passage common to the extension-side contraction side, each of which circulates the working fluid by sliding of the piston;
A shock absorber having
The extension side main passage is provided with an extension side main damping valve, and the contraction side main passage is provided with a compression side main damping valve, respectively.
On the upstream side in the extension stroke of the sub-passage and the upstream side in the contraction stroke, check valves on the inflow side are provided, respectively.
The shock absorber according to claim 1, wherein an outflow side auxiliary damping valve is provided on each of the downstream side in the extension stroke and the downstream side in the contraction stroke of the auxiliary passage. The check valve on the inflow side provided on at least one of the upstream side in the extension stroke of the sub-passage and the upstream side in the contraction stroke is configured by a laminated disk,
The shock absorber according to claim 1, wherein the laminated disk constitutes a third damping valve on the outflow side in a stroke opposite to the stroke on the upstream side.   The shock absorber according to claim 1 or 2, wherein a throttle portion is provided on at least one of the sub passages on the check valve side.

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