Damping force adjustment device, shock absorber

Abstract

The present invention provides a damping force adjustment device comprising: a control valve 70 that is provided on a flow path through which a fluid flows and that varies the area of the flow path; a case member that houses the control valve 70 and has a control sheet 76 in which is formed a through-hole that can be closed by the control valve 70; a solenoid part that applies thrust to a pressing member 63 that can come into contact with the side opposite to the side facing the control sheet 76 in the control valve 70; a coil spring 64 having one end in contact with the control valve 70 and the other end in contact with the pressing member 63; and a biasing member 75 having one end in contact with the control valve 70 and the other end fixed to the case member.

Description

Technical Field

[0005]

[0001] The present invention relates to a damping force adjusting device and a shock absorber.

Background Art

[0002] For example, the damping valve described in Patent Document 1 has a pressure control valve body that seats and unseats on a pressure control valve seat, and an opening / closing valve body that seats and unseats on an opening / closing valve seat, and includes a valve body member that opens and closes the upstream side and the downstream side of a pilot passage. Further, the damping valve described in Patent Document 1 includes a disc spring that is interposed between a step and the valve body member, biases the valve body member in a direction to separate the pressure control valve body from the pressure control valve seat and to approach the opening / closing valve body to the opening / closing valve seat, and a solenoid that can drive the valve body member against the biasing force of the disc spring. And there is described a damping valve that supplies current to the solenoid to apply a thrust to the valve body member, and presses the pressure control valve body of the valve body member against the pressure control valve seat against the biasing force of the disc spring.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the damping valve described in Patent Document 1, when current is supplied to the solenoid to apply a thrust to the valve body member, the thrust of the solenoid not only deforms the first spring but also is transmitted to the valve housing via the first spring. In other words, the limited solenoid thrust is transmitted to parts that are not necessary for operation, and there is room for improvement. An object of the present invention is to provide a damping force adjusting device and the like with good thrust efficiency that reduces waste of the thrust of the actuator unit.

Means for Solving the Problems

[0005] The present invention, completed with this objective in mind, is a damping force adjustment device comprising: a valve body provided on a fluid flow path and varying the area of ​​the flow path; a case member housing the valve body and having a valve seat with a through hole formed therein that can be closed by the valve body; an actuator unit that applies thrust to a movable member that can contact the side of the valve body opposite to the side facing the valve seat; a first spring member with one end in contact with the valve body and the other end in contact with the movable member; and a second spring member with one end in contact with the valve body and the other end fixed to the case member. [Effects of the Invention]

[0006] According to the present invention, the thrust efficiency of the actuator can be improved. [Brief explanation of the drawing]

[0007] [Figure 1] This figure shows an example of a schematic configuration of a hydraulic shock absorber according to the first embodiment. [Figure 2] This figure shows an example of a cross-section of the damping force generating device of the first embodiment. [Figure 3] This figure shows an example of a perspective cross-sectional view of the main valve section and damping force adjustment section of the first embodiment. [Figure 4] This figure shows an example of a partial cross-section of the main valve section and damping force adjustment section of the first embodiment. [Figure 5] This figure shows an example of oil flow when the pressing force of the pressing member is minimized and the piston movement speed is low. [Figure 6] This figure shows an example of oil flow when the piston is moving at a high speed while the pressing force of the pressing member is at its minimum. [Figure 7] This figure shows an example of oil flow when the piston is moving at a low speed while the pressing force of the pressing member is at its maximum. [Figure 8] This figure shows an example of oil flow when the piston is moving at a high speed while the pressing force of the pressing member is at its maximum. [Figure 9] This figure shows an example of oil flow when the solenoid is not energized and the piston is moving at a low speed. [Figure 10] This figure shows an example of oil flow when the solenoid is not energized and the piston is moving at a high speed. [Figure 11] This figure shows an example of a schematic configuration of a damping force generating device according to the second embodiment. [Figure 12] This figure shows an example of a schematic configuration of a damping force generating device according to the third embodiment. [Figure 13] This figure shows an example of a partial cross-section of a damping force generating device according to the third embodiment. [Figure 14] This figure shows an example of a state in which the biasing member is in contact with the first edge but not with the second edge. [Figure 15] This figure shows an example of a state in which the biasing member is in contact with the first edge and the second edge. [Figure 16] This figure shows an example of the control valve being seated in a round position. [Figure 17] This figure shows an example of the correlation between the current supplied to the solenoid, the thrust of the solenoid, the spring constant of the biasing member, and the opening amount of the control valve. [Modes for carrying out the invention]

[0008] Embodiments of the present invention will be described in detail below with reference to the attached drawings. <First Embodiment> [Configuration and Function of Hydraulic Shock Absorber 1] Figure 1 is a diagram showing an example of the schematic configuration of the hydraulic shock absorber 1 according to the first embodiment. As shown in FIG. 1, the hydraulic shock absorber 1 includes a cylinder portion 10 that houses oil, and a rod 20 that is provided such that the other side protrudes from the cylinder portion 10 and the one side is slidably inserted into the cylinder portion 10. Further, the hydraulic shock absorber 1 includes a piston portion 30 provided at one end of the rod 20 and a bottom portion 40 provided at one end of the cylinder portion 10. Furthermore, the hydraulic shock absorber 1 includes a damping force generator 100 provided outside the cylinder portion 10 that generates a damping force.

[0009] In the following description, the longitudinal direction of the cylinder portion 10 shown in FIG. 1 may be referred to as the "axial direction", the lower side of FIG. 1 in the axial direction may be referred to as the "one side", and the upper side of FIG. 1 may be referred to as the "other side". Also, the left - right direction of the cylinder portion 10 shown in FIG. 1 may be referred to as the "radial direction", and in the radial direction, the side closer to the central axis of the cylinder portion 10 may be referred to as the "inside", and the side away from the central axis may be referred to as the "outside".

[0010] The cylinder portion 10 has a cylinder 11 that houses oil, an outer cylinder 12 provided outside the cylinder 11, and a damper case 13 provided outside the cylinder 11 and further outside the outer cylinder 12.

[0011] The cylinder 11 is formed in a cylindrical shape, and a communication hole 11H that communicates the inside and the outside is formed at the other end. The outer cylinder 12 is formed in a cylindrical shape. And the outer cylinder 12 forms a communication path L between it and the cylinder 11. Also, the outer cylinder 12 has an outer cylinder opening 12H and an outer connection portion 12J at a position facing the damping force generator 100. The outer connection portion 12J has an oil flow path and protrudes outward to form a connection location with the damping force generator 100.

[0012] The damper case 13 is formed in a cylindrical shape. The damper case 13 forms a reservoir chamber R between itself and the outer cylinder 12 where oil accumulates. The reservoir chamber R absorbs oil from the cylinder 11 and supplies oil to the cylinder 11 as the rod 20 moves relative to the cylinder 11. The reservoir chamber R also collects oil that flows out from the damping force generating device 100. The damper case 13 also has a case opening 13H at a position opposite the damping force generating device 100.

[0013] The rod 20 is a rod-shaped member that extends long in the axial direction. The rod 20 holds the piston portion 30 on one end. The rod 20 is connected to, for example, the vehicle body on the other end via a connecting member or the like (not shown).

[0014] The piston section 30 includes a piston body 31 having a plurality of piston oil passages 311, a piston valve 32 that opens and closes the other side of the piston oil passages 311, and a spring 33 provided between the piston valve 32 and one end of the rod 20. The piston section 30 divides the oil in the cylinder 11 into a first oil chamber Y1 and a second oil chamber Y2.

[0015] The bottom portion 40 includes a valve seat 41, a check valve portion 43 provided on the other side of the valve seat 41, and a fixing member 44 provided in the axial direction. The bottom portion 40 separates the first oil chamber Y1 from the reservoir chamber R.

[0016] [Configuration and functions of the damping force generating device 100] Figure 2 shows an example of a cross-section of the damping force generating device 100 according to the first embodiment. Figure 3 shows an example of a perspective cross-sectional view of the main valve section 50 and the damping force adjustment section 60 of the first embodiment. Figure 4 shows an example of a partial cross-section of the main valve section 50 and the damping force adjustment section 60 of the first embodiment.

[0017] In the following explanation, the longitudinal direction of the damping force generating device 100 shown in Figure 2 (i.e., the intersecting direction that intersects the axial direction of the cylinder portion 10 (see Figure 1) (for example, a nearly orthogonal direction)) may be referred to as the "second axial direction." Also, in the second axial direction, the side of the cylinder portion 10 that is on the central axis side (the left side of the damping force generating device 100 in Figure 2) may be referred to as the "first side," and the side that is away from the central axis of the cylinder portion 10 (the right side of the damping force generating device 100 in Figure 2) may be referred to as the "second side." Furthermore, the direction of the damping force generating device 100 shown in Figure 2 (i.e., the direction intersecting the second axis direction) is sometimes referred to as the "second radial direction." In the second radial direction, the side of the central axis along the second axis is sometimes referred to as the "second inner side," and the side of the second axis that is away from the central axis is sometimes referred to as the "second outer side."

[0018] As shown in Figure 2, the damping force generating device 100 includes a main valve section 50 that mainly generates damping force in the hydraulic shock absorber 1 of the first embodiment, and a damping force adjustment section 60 that adjusts the magnitude of the damping force generated by the damping force generating device 100. Furthermore, the damping force generating device 100 includes a connecting section 80 that forms a parallel flow path with respect to the main valve section 50, a connecting flow path section 90 that forms an oil flow path from the connecting passage L with respect to the main valve section 50 and the connecting section 80, and an outer housing 100C that houses various components that constitute the damping force generating device 100.

[0019] (Main valve section 50) The main valve section 50 includes a main valve 51 that generates damping force by controlling the flow of oil to restrict it, and a main valve seat 52 that faces the main valve 51 and is in contact with the main valve 51.

[0020] As shown in Figure 3, the main valve 51 is a disc-shaped member that has an opening 51H on its second inner side and is elastically deformable. The material of the main valve 51 can be a metal such as iron. As shown in Figure 4, the connecting portion 80 passes through the opening 51H of the main valve 51. The main valve 51 is sandwiched between the main valve seat 52 and the spacer member 684 (described later) on the second inner side. The main valve 51 faces the second side of the main valve seat 52.

[0021] The main valve 51, configured as described above, has its position restricted in the second radial direction by the connecting portion 80. Furthermore, the second inner side of the main valve 51 has its movement restricted in the second axial direction by the main valve seat 52 and the spacer member 684 (described later). On the other hand, the second outer side of the main valve 51 can move in the second axial direction by deforming. The main valve 51 then generates a damping force by restricting the oil flow in the main passage 53 (described later) of the main valve seat 52.

[0022] Next, I will explain the main valve seat 52. As shown in Figure 3, the main valve seat 52 is a cylindrical member having an opening 52H on its second inner side. A connecting portion 80 is inserted into a part of the opening 52H of the main valve seat 52 (see Figure 4).

[0023] The main valve seat 52 has a central seat portion 520 around the opening 52H. The main valve seat 52 also has an inner seat portion 521 located second outside the central seat portion 520, and an outer seat portion 522 located second outside the inner seat portion 521. Furthermore, the main valve seat 52 has a main flow path 53 that penetrates in a second axial direction second outside the opening 52H.

[0024] The central seat portion 520 protrudes in an arc shape toward the main valve 51. The second inner portion of the main valve 51 faces the central seat portion 520. The inner seat portion 521 is formed in an annular shape. The inner seat portion 521 protrudes beyond the flow channel opening 532 toward the main valve 51. The protruding height of the inner seat portion 521 is approximately equal to that of the central seat portion 520 and the outer seat portion 522. The outer seat portion 522 is formed in an annular shape. The outer seat portion 522 protrudes beyond the flow channel opening 532 toward the main valve 51. The inner seat portion 521 and the outer seat portion 522 form contact points with the main valve 51.

[0025] Furthermore, the inner seat portion 521 has a plurality of grooves 521T formed along the second radial direction. The flow path cross-sectional area of ​​each groove 521T is formed to be relatively small. That is, the grooves 521T constitute so-called orifice flow paths. Each groove 521T then forms a flow path through which oil flows from the second inner side of the inner seat portion 521 to the second outer side of the inner seat portion 521 when the main valve 51 is in contact with the inner seat portion 521.

[0026] The main flow path 53 forms a parallel flow path with respect to the back pressure flow path 77 of the control sheet 76, which will be described later (see Figure 4). Multiple main flow paths 53 are provided in the circumferential direction (see Figure 3). The first flow path opening 531 of each main flow path 53 is connected to the opening 52H and faces the connecting flow path section 90. The second flow path opening 532 of each main flow path 53 is located between the central sheet section 520 and the inner sheet section 521.

[0027] (Damping force adjustment section 60) As shown in Figure 2, the damping force adjustment unit 60 includes a reciprocating unit 61 that moves the control valve 70 (described later) forward and backward relative to the control seat 76, a cap unit 67 that covers various components such as the main valve unit 50, and a back pressure generation mechanism 68 that changes the ease with which the main valve 51 deforms relative to the main valve seat 52. The damping force adjustment unit 60 also includes a control valve 70 that restricts and controls the flow of oil in the contact unit 80, a control seat 76 which is a valve seat that faces the control valve 70 and into contact with the control valve 70, and a restricting member 83 that restricts the flow of oil. The damping force adjustment unit 60 also includes a restricting member 72 that restricts the movement of the control valve 70 toward the second side, and a biasing member 75 that applies a force to the control valve 70 in the direction opposite to the thrust of the solenoid unit 62. Furthermore, the damping force adjustment section 60 includes a first spacer member 73A interposed between the biasing member 75 and the regulating member 72, a second spacer member 73B interposed between the regulating member 72 and the cap portion 67, and a third spacer member 73C interposed between the control sheet 76 and the biasing member 75.

[0028] ((Advance / retreat part 61)) As shown in Figure 2, the reciprocating section 61 includes a solenoid section 62 that uses an electromagnet to move a pressing member 63 (described later) back and forth, a pressing member 63 that presses the control valve 70 against the control seat 76, and a coil spring 64 provided between the pressing member 63 and the control valve 70. The reciprocating section 61 also includes a solenoid case 60C that houses and supports the components constituting the reciprocating section 61.

[0029] The solenoid section 62 has a plunger 65 that moves back and forth along the second axis, and when the electromagnet is energized, it pushes the plunger 65 toward the first side. When the solenoid section 62 is de-energized, the plunger 65 is pulled back toward the second side by the coil spring 64.

[0030] As shown in Figure 4, the pressing member 63 has a cylindrical portion 631, a bottom portion 632 that covers the first opening of the cylindrical portion 631, and a flange portion 633 provided at the second end of the cylindrical portion 631 that protrudes outward to the second side around its entire circumference. The coil spring 64 is a compression coil spring that contacts the control valve 70 on the first side and the pressing member 63 on the second side. The coil spring 64 applies a force to the pressing member 63 and the control valve 70 that causes them to move away from each other. In place of the coil spring 64, another component, such as an elastic ring, can be used as long as it performs a similar function.

[0031] ((Cap part 67)) As shown in Figure 3, the cap portion 67 has a first opening 67H1 formed on the first side and a second opening 67H2 formed on the second side, and is a component with a general cylindrical shape. The inner diameter of the first opening 67H1 is larger than the inner diameter of the second opening 67H2. Furthermore, the cap portion 67 has multiple inner diameter sections, each with a different inner diameter. Of the multiple inner diameter sections, the inner diameter section provided on the first side is formed to have a larger inner diameter than the inner diameter section provided on the second side. For example, the cap portion 67 has a first inner diameter section 671 on the first side of the second opening 67H2, a second inner diameter section 672 on the first side of the first inner diameter section 671, and a third inner diameter section 673 on the first side of the second inner diameter section 672.

[0032] As shown in Figure 4, the cap portion 67 houses the main valve portion 50, the damping force adjustment portion 60, and the connecting portion 80 inside. More specifically, the cap portion 67 houses the main valve 51 and the control valve 70 of the main valve portion 50. In addition, a part of the cap portion 67, together with the back pressure generation mechanism 68 and the control seat 76, forms a back pressure chamber 68P that applies oil pressure (hereinafter sometimes referred to as "back pressure") from the second side opposite the main valve seat 52 to the main valve 51.

[0033] As shown in Figure 2, the cap portion 67 is fixed by being sandwiched between the solenoid case 60C and the connecting flow path portion 90. The cap portion 67 also forms a cap flow path 67R through which oil flows between itself and the solenoid case 60C. The cap flow path 67R is connected to the second opening 67H2 and also to the housing internal flow path 111, which will be described later.

[0034] Furthermore, the cap portion 67 is provided with a plunger 65 passing through the second opening 67H2. Also, within the cap portion 67, a pressing member 63 moves back and forth against the second opening 67H2. Furthermore, a groove 675 is formed on the first side edge of the second opening 67H2 of the cap portion 67. When the pressing member 63 moves to the second side and contacts the cap portion 67, the groove 675 forms a cap orifice passage 67R2 (see Figure 9) through which oil flows between the flange portion 633 of the pressing member 63 and the cap portion 67. The cap orifice passage 67R2 connects to the cap passage 67R via the second opening 67H2.

[0035] In the first embodiment, the oil flow path cross-sectional area in the groove 675 is set to raise the pressure in the back pressure chamber 68P to a certain level or higher when the solenoid 62 is de-energized. Furthermore, the oil flow path cross-sectional area in the groove 675 is set so that when the solenoid 62 is de-energized, oil flows into the groove 675 to the extent that the main valve 51 opens the main flow path 53 and oil flows.

[0036] The configuration for generating oil flow between the cap portion 67 and the pressing member 63 when the solenoid portion 62 is de-energized is not limited to the groove portion 675. For example, by providing a groove portion in the pressing member 63, oil flow between the pressing member 63 and the cap portion 67 may be enabled when the pressing member 63 is in contact with the cap portion 67. Alternatively, a configuration in which a groove portion 675 is formed in the cap portion 67 and a groove portion is also provided in the pressing member 63 may be used. Furthermore, the configuration for generating oil flow between the cap portion 67 and the pressing member 63 when the pressing member 63 is in contact with the cap portion 67 is not limited to a groove portion, but may also be a through hole.

[0037] ((Back pressure generation mechanism 68)) As shown in Figure 3, the back pressure generating mechanism 68 includes a partition member 681 provided on the side opposite the main valve seat 52 to the main valve 51, i.e., on the second side, and a sealing member 682 that seals the space between the cap portion 67 and the partition member 681. Furthermore, the back pressure generating mechanism 68 includes a return spring 683 that applies a force to the partition member 681 that presses it against the main valve 51, and a spacer member 684 interposed between the return spring 683 and the main valve 51.

[0038] The partition member 681 is generally formed in a roughly annular shape. The partition member 681 is movable in the second axial direction. For example, when the main valve 51 deforms toward the second side, the partition member 681 moves toward the second side. Also, when the main valve 51 deforms toward the first side, the partition member 681 moves toward the first side.

[0039] Furthermore, the partition member 681 has a main valve contact portion 681V that contacts the main valve 51 and a seal contact portion 681S on which a seal member 682 is provided.

[0040] The main valve contact portion 681V is provided on the first side of the partition member 681. The main valve contact portion 681V is formed so that its width gradually narrows from the second side to the first side. This main valve contact portion 681V makes annular contact with the main valve 51. The partition member 681 constitutes one of the components that form the back pressure chamber 68P.

[0041] Here, the back pressure chamber 68P is a chamber into which oil flows, causing an oil pressure corresponding to the incoming oil to act on the main valve 51. The back pressure chamber 68P then acts to apply a force to the main valve 51 that presses it against the main valve seat 52.

[0042] As shown in Figure 3, the sealing member 682 is formed in an annular shape. Furthermore, the sealing member 682 can be made of an elastically deformable resin material such as engineering plastic or rubber. As shown in Figure 4, the sealing member 682 seals the space between the partition member 681 and the third inner diameter portion 673 of the cap portion 67. More specifically, the outer circumferential surface 682G of the sealing member 682 contacts the inner circumference of the third inner diameter portion 673 of the cap portion 67. In addition, the first end face 682T of the sealing member 682 contacts the partition member 681. As a result, the sealing member 682 prevents oil in the back pressure chamber 68P from flowing out of the back pressure chamber 68P through the space between the partition member 681 and the cap portion 67.

[0043] As shown in Figure 3, the return spring 683 has an annular portion 683R formed in an annular shape and a plurality of arm portions 683A that protrude outward from the annular portion 683R. Furthermore, an elastic material such as metal can be used for the material of the return spring 683. As shown in Figure 4, the return spring 683 has a connecting portion 80 that passes through the annular portion 683R, and the annular portion 683R is sandwiched in the second axial direction by a plurality of spacer members 684. In addition, the arm portion 683A of the return spring 683 is in contact with the sealing member 682.

[0044] The return spring 683 has a configuration where the annular portion 683R is fixed by the spacer member 684 and the arm portion 683A contacts the seal member 682 are different in the second axial direction. Furthermore, the arm portion 683A has a shape that is inclined with respect to the second axial direction. In addition, the arm portion 683A contacts the second inner corner on the second side of the seal member 682. As a result, the arm portion 683A imparts a spring force to the seal member 682 that has a component along the second axial direction and a spring force that has a component along the second radial direction.

[0045] Furthermore, in the first embodiment, the arm portion 683A of the return spring 683 is also in contact with the bulkhead member 681. The return spring 683 then applies a spring force to the bulkhead member 681 that has a component along the second axial direction and a spring force that has a component along the second radial direction.

[0046] ((Control valve 70)) The control valve 70 has a cylindrical portion 701 and a conical portion 702 that covers the first opening of the cylindrical portion 701 and protrudes toward the first side. The control valve 70 also has a projection 71 at the first end of the cylindrical portion 701 that protrudes toward the second outer side over its entire circumference. The control valve 70 also has a flat surface 703 perpendicular to the second axial direction at the second end of the conical portion 702, on the second inner side. The control valve 70 also has a convex portion 706 at the center of the conical portion 702 in the second axial direction that protrudes toward the second outer side. A flat surface 707 perpendicular to the second axial direction is formed on the convex portion 706.

[0047] The outer diameter of the cylindrical portion 701 is greater than or equal to the outer diameter of the flange portion 633 of the pressing member 63, while the inner diameter of the cylindrical portion 701 is smaller than the outer diameter of the flange portion 633. As a result, the second end face of the cylindrical portion 701 comes into contact with the flange portion 633 of the pressing member 63.

[0048] Furthermore, the inner diameter of the cylindrical portion 701 is larger than the outer diameter of the cylindrical portion 631 of the pressing member 63. This allows the second end face of the cylindrical portion 701 to contact the flange portion 633 of the pressing member 63, while the cylindrical portion 631 and bottom portion 632 of the pressing member 63 are housed inside the second part of the control valve 70. A coil spring 64 (an example of an elastic member) is then positioned inside the space 704 (an example of a spring space) formed between the cylindrical portion 701 of the control valve 70 and the cylindrical portion 631 of the pressing member 63. The first end of the coil spring 64 is supported by the flat surface 703 of the control valve 70, and the second end of the coil spring 64 is supported by the flange portion 633 of the pressing member 63. Thus, the coil spring 64 is a member that acts at both ends and does not have a fixed end. Therefore, Since the thrust of the solenoid section 62 applied to the coil spring 64 is entirely used to deform the coil spring 64 itself, the thrust efficiency is excellent.

[0049] ((regulating member 72)) As shown in Figure 3, the regulating member 72 has an annular portion 721 formed in an annular shape and a plurality of arm portions 722 that protrude from the annular portion 721 toward the second inner side. The plurality of arm portions 722 are provided in four equal intervals in the circumferential direction of the annular portion 721. The circumferential size of the arm portions 722 gradually decreases from the second outer side toward the second inner side. The diameter of the virtual circle formed by the second inner tips of the plurality of arm portions 722 is larger than the diameter of the outer circumferential surface of the cylindrical portion 701 of the control valve 70 and smaller than the diameter of the outer circumferential surface of the protruding portion 71.

[0050] ((First spacer member 73A, second spacer member 73B, and third spacer member 73C)) The first spacer member 73A, the second spacer member 73B, and the third spacer member 73C are annular members. The outer diameters of the first spacer member 73A, the second spacer member 73B, and the third spacer member 73C are larger than the inner diameter of the first inner diameter portion 671 of the cap portion 67 and smaller than the inner diameter of the second inner diameter portion 672. Also, the inner diameters of the first spacer member 73A, the second spacer member 73B, and the third spacer member 73C are larger than the inner diameter of the first inner diameter portion 671 of the cap portion 67 and smaller than the inner diameter of the second inner diameter portion 672.

[0051] The first spacer member 73A and the second spacer member 73B are positioned between the first end face of the first inner diameter portion 671 of the cap portion 67 and the biasing member 75 to determine the second axial position of the regulating member 72. More specifically, the regulating member 72 is positioned second to the protrusion 71 of the control valve 70 and restricts the control valve 70 from moving to the second side.

[0052] Furthermore, the position of the restricting member 72 in the second axial direction can be adjusted by adjusting the size (hereinafter sometimes referred to as "thickness") of the first spacer member 73A and the second spacer member 73B. For example, if you want to set the position of the restricting member 72 in the second axial direction to the first side of Figure 4, you should make the thickness of the first spacer member 73A thinner than the thickness shown in Figure 4 and the thickness of the second spacer member 73B thicker than the thickness shown in Figure 4. On the other hand, if you want to set the position of the restricting member 72 in the second axial direction to the second side of Figure 4, you should make the thickness of the first spacer member 73A thicker than the thickness shown in Figure 4 and the thickness of the second spacer member 73B thinner than the thickness shown in Figure 4.

[0053] The third spacer member 73C is positioned between the biasing member 75 and the control sheet 76, and determines the position of the biasing member 75 in the second axial direction. The position of the biasing member 75 in the second axial direction can be adjusted by adjusting the size (hereinafter sometimes referred to as "thickness") of the third spacer member 73C in the second axial direction. For example, if you want to set the position of the biasing member 75 in the second axial direction to the first side of Figure 4, you should make the thickness of the third spacer member 73C thinner than the thickness shown in Figure 4, and the thickness of the first spacer member 73A thicker than the thickness shown in Figure 4. On the other hand, if you want to set the position of the biasing member 75 in the second axial direction to the second side of Figure 4, you should make the thickness of the third spacer member 73C thicker than the thickness shown in Figure 4, and the thickness of the first spacer member 73A thinner than the thickness shown in Figure 4.

[0054] ((Biasing member 75)) The biasing member 75 is an annular leaf spring that applies a force to the control valve 70 in a direction opposite to the thrust of the solenoid 62 and the spring force of the coil spring 64, and is set to a higher spring constant than the coil spring 64. The biasing member 75 is formed in an annular shape and has an annular portion 751 that functions as a fixed end, and a plurality of arm portions 752 that protrude from the annular portion 751 toward the second inward and function as working ends. The shape of the biasing member 75 is not limited to this, and as long as it has a fixed end and working ends that act on the control valve 70, the shape is not particularly limited. For example, the plurality of arm portions 752 are provided in three equal intervals in the circumferential direction of the annular portion 751. However, the number of arm portions 752 is not limited to three, and may be two or fewer, or four or more. Also, the shapes of the plurality of arm portions 752 may all be the same, or they may each be different. For example, the circumferential size of each of the plurality of arm portions 752 may be different. The biasing member 75 does not have to be a leaf spring; it may be an elastic member such as a coil spring interposed between the control valve 70 and the control seat 76.

[0055] ((Control Sheet 76)) The control sheet 76, together with the cap portion 67, has an outer sheet portion 761 that holds the regulating member 72, the biasing member 75, the first spacer member 73A, the second spacer member 73B, and the third spacer member 73C, and a recess 762 provided on the second inner side, recessed from the second side surface of the outer sheet portion 761. In the second inner portion of the recess 762, a back pressure passage 77 is formed, which is a hole that penetrates in the second axial direction and forms an oil passage for adjusting the oil pressure in the back pressure chamber 68P. The control sheet 76 has a round 77R around the back pressure passage 77 that protrudes second to the bottom of the recess 762.

[0056] Furthermore, the control sheet 76 is provided on the first side of the back pressure passage 77 and has a communication chamber 78 that connects to the back pressure passage 77. Around the communication chamber 78 in the control sheet 76, multiple back pressure communication passages 79 are formed in the circumferential direction, which are holes penetrating in the second radial direction and connect the communication chamber 78 and the back pressure chamber 68P. The control seat 76 configured as described above, together with the control valve 70, is provided on the discharge passage described later and constitutes a valve 700 that varies the area of ​​the discharge passage.

[0057] ((restriction member 83)) The throttling member 83 is fitted to the first side of the communication chamber 78 of the control seat 76 and has a cylindrical portion 831 and a blocking portion 832 that closes the second opening in the cylindrical portion 831. A back pressure orifice passage 84 is formed in the blocking portion 832, which connects the inflow passage 81 (described later) and the communication chamber 78. The back pressure orifice passage 84 is formed so that the cross-sectional area of ​​the oil passage is smaller than that of the back pressure communication passage 79 and the back pressure passage 77. The back pressure orifice passage 84 makes it difficult for the oil in the back pressure chamber 68P to return to the inflow passage 81.

[0058] (Liaison Department 80) As shown in Figure 3, the communication section 80 of the first embodiment has an inflow channel 81 through which oil flows in from the communication passage L, and a connection section 89 that connects to the control sheet 76. The inner diameter of the connecting portion 89 is approximately equal to the outer diameter of the first side of the control sheet 76. The first end of the control sheet 76 is inserted into the connecting portion 89. Alternatively, the connecting portion 80 may be inserted into the inside of the control sheet 76.

[0059] (Connecting channel section 90) As shown in Figure 2, the connecting channel section 90 has an inner channel 91 provided on the second inner side and an outer channel 92 provided on the second outer side.

[0060] The inner flow path 91 connects to the outer cylinder opening 12H on the first side and to the inflow flow path 81 of the connecting section 80 and the main flow path 53 of the main valve seat 52 on the second side. Multiple outer flow channels 92 are provided in the circumferential direction. The outer flow channels 92 connect to the case opening 13H on the first side and to the housing internal flow channel 111 on the second side.

[0061] (Outer housing 100C) As shown in Figure 2, the outer housing 100C is a substantially cylindrical member. The outer housing 100C is fixed to the damper case 13 on the first side, for example by welding. Furthermore, the outer housing 100C has an internal housing passage 111, which is an oil passage within the outer housing 100C, located on the second outer side of the main valve section 50 and the damping force adjustment section 60. The internal passage 111 of the housing is designed to receive oil that has flowed out from the second opening 67H2 of the cap portion 67, and oil that has flowed out from the main passage 53 of the main valve seat 52 when the main valve 51 is opened.

[0062] [Adjustment operation of damping force adjustment unit 60] Next, the adjustment operation in the damping force adjustment unit 60 will be described. As shown in Figure 4, by pushing the pressing member 63 toward the first side, the control valve 70 is pressed against the control seat 76. The pressing force of the pressing member 63, in other words, the thrust of the solenoid section 62, changes according to the amount of current flowing through the solenoid section 62 (see Figure 2).

[0063] For example, in the damping force adjustment section 60, the pressing force of the pressing member 63 is set to its maximum. At this time, the control valve 70 is pressed most strongly against the back pressure passage 77 of the control seat 76, and the back pressure passage 77 is closed (see Figure 7).

[0064] Furthermore, for example, in the damping force adjustment section 60, the pressing force of the pressing member 63 is set to the smallest possible state. At this time, in the damping force adjustment section 60, the control valve 70 moves away from the back pressure passage 77, and the back pressure passage 77 is opened (see Figure 5).

[0065] Furthermore, for example, in the damping force adjustment unit 60, the pressing force of the pressing member 63 is set to a state between the state in which the pressing force is smallest and the state in which it is largeest. In this state, in the damping force adjustment unit 60, the control valve 70 is further away from the back pressure passage 77 than in the state in which the pressing force is largest, and closer to the back pressure passage 77 than in the state in which the pressing force is smallest.

[0066] [Operation of hydraulic shock absorber 1] First, we will explain the operation of the hydraulic shock absorber 1 during the extension stroke. During the extension stroke, the rod 20 moves to the other side relative to the cylinder 11. At this time, the piston valve 32 remains closed to the piston oil passage opening 311. Also, as the piston portion 30 moves to the other side, the volume of the second oil chamber Y2 decreases. Then, the oil in the second oil chamber Y2 flows out from the communication hole 11H into the connecting passage L.

[0067] Furthermore, the oil flows into the damping force generating device 100 through the connecting passage L and the outer cylinder opening 12H. In the damping force generating device 100, the oil first flows into the inner passage 91 of the connecting passage section 90. Subsequently, damping force is generated in the main valve 51 or the control valve 70 in the damping force generating device 100. The flow of the oil at this time will be explained in detail later.

[0068] Subsequently, the oil that has flowed to the main valve 51 or the control valve 70 flows out into the internal passage 111 of the housing. Furthermore, the oil flows through the outer passage 92 of the connecting passage section 90 and into the reservoir chamber R from the case opening 13H.

[0069] Furthermore, the pressure in the first oil chamber Y1 is relatively lower than that in the reservoir chamber R. As a result, the oil in the reservoir chamber R flows into the first oil chamber Y1 through the bottom section 40.

[0070] Next, the operation of the hydraulic damper 1 during the compression stroke will be explained. During the compression stroke, the rod 20 moves relative to the cylinder 11 to one side. In the piston section 30, the differential pressure between the first oil chamber Y1 and the second oil chamber Y2 opens the piston valve 32 that closes the piston oil passage opening 311. The oil in the first oil chamber Y1 then flows out into the second oil chamber Y2 through the piston oil passage opening 311. Here, the rod 20 is located in the second oil chamber Y2. Therefore, the amount of oil flowing from the first oil chamber Y1 to the second oil chamber Y2 is in excess by the volume of the rod 20. Consequently, an amount of oil equivalent to the volume of this rod 20 flows out into the connecting passage L through the connecting hole 11H.

[0071] Furthermore, the oil flows into the damping force generating device 100 through the connecting passage L and the outer cylinder opening 12H. The oil flow in the damping force generating device 100 is the same as the oil flow during the extension stroke described above. In other words, in the hydraulic shock absorber 1 of the first embodiment, the direction of oil flow in the damping force generating device 100 is the same during both the compression stroke and the extension stroke.

[0072] As described above, the hydraulic damping device 1 generates damping force in the damping force generating device 100 during both the compression stroke and the extension stroke.

[0073] Next, the oil flow in the damping force generating device 100 will be explained in detail. (normal time) The oil flow during normal operation, when the solenoid unit 62 is energized and the pressing force of the pressing member 63 is applied, will be explained.

[0074] ((at low speed)) Figure 5 shows an example of oil flow when the pressing force of the pressing member 63 is at its minimum and the moving speed of the piston portion 30 (see Figure 1) is low. As shown in Figure 5, when the piston portion 30 is moving at a low speed, the oil that flows into the inner passage 91 flows into the inflow passage 81 and the main passage 53. Here, because the piston portion 30 is moving at a low speed, no oil flow occurs in the main passage 53 that would open the main valve 51. Meanwhile, the oil that flows into the inflow channel 81 flows in the following order, as shown by the arrows in Figure 5: back pressure orifice channel 84, communication chamber 78, back pressure channel 77, second opening 67H2, and cap channel 67R. The oil then flows out of the housing internal channel 111 into the reservoir chamber R. As described above, when the piston section 30 is moving at a low speed, the damping force is generated by the restriction of oil flow due to the gap between the round 77R and the control valve 70.

[0075] ((at high speed)) Figure 6 shows an example of oil flow when the pressing force of the pressing member 63 is minimized and the moving speed of the piston portion 30 (see Figure 1) is high. As shown in Figure 6, when the piston section 30 is moving at a high speed, the oil that flows into the inner passage 91 flows into the inflow passage 81 and the main passage 53. The oil that flows into the main passage 53 opens the main valve 51 and flows out into the reservoir chamber R. Even at high speeds, the oil flowing into the inflow passage 81 flows to the housing passage 111, generating a differential pressure due to the gap between the round 77R and the control valve 70, as is the case at low speeds, and then flows out into the reservoir chamber R.

[0076] As described above, when the piston section 30 moves at a high speed, the damping force is mainly generated by the flow of oil in the main passage 53 of the main valve seat 52.

[0077] Furthermore, the oil flowing into the inflow passage 81 transmits pressure to the back pressure chamber 68P through the back pressure orifice passage 84 and the back pressure connecting passage 79. However, the back pressure passage 77, which connects to the back pressure chamber 68P, is open by the control valve 70. Therefore, the pressure in the back pressure chamber 68P is lower compared to the case where the control valve 70 is pressed against the back pressure passage 77. The main valve 51, which is in contact with the back pressure generation mechanism 68, is more likely to open the main passage 53. Consequently, when the pressing force of the pressing member 63 is at its smallest, the damping force generated by the oil flow in the main passage 53 that opens the main valve 51 is lower than when the pressing force of the pressing member 63 is at its largest.

[0078] Figure 7 shows an example of oil flow when the pressing force of the pressing member 63 is at its maximum and the moving speed of the piston portion 30 (see Figure 1) is low. ((at low speed)) As shown in Figure 7, when the piston portion 30 moves at a low speed, the oil that flows into the inner passage 91 flows into the inflow passage 81 and the main passage 53. However, because the piston portion 30 moves at a low speed, the main valve 51 is not opened and no oil flows through the main passage 53. Meanwhile, the oil that flows into the inflow channel 81 flows into the back pressure orifice channel 84 and the communication chamber 78, as indicated by the arrows in Figure 7. The oil then flows through the back pressure channel 77, opening the control valve 70. Furthermore, the oil flows through the second opening 67H2 and the cap channel 67R in that order. Finally, the oil flows out of the housing internal channel 111 into the reservoir chamber R.

[0079] As described above, when the piston section 30 is moving at a low speed, the damping force is generated by the oil flowing through the back pressure passage 77 while the control valve 70 is open. The damping force when the oil flows through this back pressure passage 77 is higher compared to when the control valve 70 is far from the back pressure passage 77.

[0080] ((at high speed)) Figure 8 shows an example of oil flow when the pressing force of the pressing member 63 is maximized and the moving speed of the piston portion 30 (see Figure 1) is high. As shown in Figure 8, when the piston section 30 is moving at a high speed, the oil that flows into the inner passage 91 flows into the inflow passage 81 and the main passage 53. The oil that flows into the main passage 53 opens the main valve 51 and flows out into the reservoir chamber R. Even at high speeds, the oil flowing into the inflow channel 81 flows to the housing channel 111 while generating a differential pressure due to the flow rate being restricted by the gap between the round 77R and the control valve 70, similar to when the pressing force of the pressing member 63 is at its lowest, and then flows out into the reservoir chamber R. As described above, when the piston section 30 moves at a high speed, the damping force is mainly generated by the flow of oil in the main passage 53 of the main valve seat 52.

[0081] Furthermore, the oil flowing into the inflow passage 81 transmits pressure to the back pressure chamber 68P through the back pressure orifice passage 84 and the back pressure connecting passage 79. The back pressure passage 77, which connects to the back pressure chamber 68P, is held closed by the control valve 70. As a result, the pressure in the back pressure chamber 68P is higher than when the back pressure passage 77 is open. Consequently, the main valve 51, which is in contact with the back pressure generation mechanism 68, is less likely to open the main passage 53. Therefore, when the pressing force of the pressing member 63 is at its greatest, the damping force generated by the oil flow in the main passage 53 that opens the main valve 51 is higher than when the pressing force of the pressing member 63 is at its least.

[0082] As described above, the hydraulic shock absorber 1 is designed to adjust both the damping force at low speeds and the damping force at high speeds by operating the pressing member 63. Specifically, the hydraulic shock absorber 1 adjusts the flow area of ​​the back pressure passage 77, which is the oil passage at low speeds, and the flow area of ​​the back pressure passage 77, which adjusts the pressure in the back pressure chamber 68P related to the oil passage area at high speeds, by changing the pressing force of the control valve 70 against the control seat 76 using the pressing member 63.

[0083] In the above-described operation example, two patterns were explained: the state where the pressing force of the pressing member 63 is smallest and the state where it is largeest. However, the operation is not limited to these two patterns. The pressing force of the pressing member 63 can be arbitrarily set within an adjustable range according to the amount of current supplied to the solenoid unit 62, in other words, the thrust of the solenoid unit 62. With this setting, the damping force adjustment unit 60 can also adjust the damping force at low speeds and the damping force at high speeds in multiple stages.

[0084] (When abnormality occurs) Next, we will explain the oil flow in an abnormal situation where the solenoid unit 62 is de-energized and the pressing force of the pressing member 63 does not act. An example of a situation in which the solenoid unit 62 is de-energized is when the current supplied to the coil of the solenoid unit 62 stops, for example, due to a broken wire. Figure 9 shows an example of oil flow when the solenoid section 62 is not energized and the piston section 30 (see Figure 1) is moving at a low speed. Figure 10 shows an example of oil flow when the solenoid section 62 is not energized and the piston section 30 is moving at a high speed.

[0085] As shown in Figures 9 and 10, when the solenoid 62 is de-energized, the plunger 65 is pushed back to the second side by the coil spring 64. Consequently, the pressing member 63 fixed to the plunger 65 is pressed against the cap 67.

[0086] ((at low speed)) As shown in Figure 9, when the piston section 30 is moving at a low speed, the oil that flows into the inflow passage 81 flows in the following order: back pressure orifice passage 84, connecting chamber 78, back pressure passage 77, cap orifice passage 67R2, second opening 67H2, and cap passage 67R. The oil then flows out of the housing passage 111 into the reservoir chamber R. Furthermore, when the piston portion 30 is moving at a low speed, the damping force is generated by the flow of oil in the cap orifice passage 67R2 formed between the flange portion 633 and the cap portion 67 of the pressing member 63.

[0087] ((at high speed)) As shown in Figure 10, when the piston section 30 is moving at a high speed, the oil that flows into the inner passage 91 flows into the inflow passage 81 and the main passage 53. The oil that flows into the main passage 53 opens the main valve 51 and flows out into the reservoir chamber R. Even at high speeds, the oil flowing into the inflow channel 81 flows to the housing channel 111 while generating a differential pressure due to the flow rate being restricted by the cap orifice channel 67R2, similar to the case at low speeds, and then flows out into the reservoir chamber R. As described above, when the piston section 30 moves at a high speed, the damping force is mainly generated by the flow of oil in the main passage 53 of the main valve seat 52.

[0088] Here, the oil flowing into the inflow passage 81 transmits pressure to the back pressure chamber 68P through the back pressure orifice passage 84 and the back pressure connecting passage 79. The back pressure chamber 68P is connected to the housing internal passage 111 via the back pressure passage 77. The oil flow between the back pressure chamber 68P and the housing internal passage 111 must pass through the cap orifice passage 67R2. The oil flow is restricted by the cap orifice passage 67R2, which suppresses the outflow of oil from the back pressure chamber 68P, and maintains the pressure in the back pressure chamber 68P at a level higher than the minimum pressing force of the pressing member 63 shown in Figure 6. As a result, the main valve 51, which is in contact with the back pressure generation mechanism 68, is relatively difficult to open the main passage 53. Therefore, when the solenoid section 62 is not energized, the damping force generated by the oil flow in the main passage 53 that opens the main valve 51 is relatively high.

[0089] As described above, in the hydraulic damping device 1 of the first embodiment, even in the abnormal situation where the solenoid section 62 is not energized, both the damping force at low speeds and the damping force at high speeds are made relatively high.

[0090] (Regarding the differences between normal and abnormal conditions) When the combined force of the oil passing through the back pressure passage 77, which moves the control valve 70 to the second side, and the force of the coil spring 64 exceeds the pressing force of the pressing member 63, the control valve 70 moves to the second side, even if a thrust is generated in the solenoid section 62. In particular, when the thrust of the solenoid section 62 is relatively small, such as in the state where the pressing force of the pressing member 63 is smallest as shown in Figures 5 and 6, the control valve 70 temporarily moves to the second side when the pressure of the oil passing through the back pressure passage 77 increases.

[0091] In the damping force generating device 100, even if the control valve 70 moves to the second side, the regulating member 72 suppresses the movement of the control valve 70 to the second side. In other words, the control valve 70 receives a force from the regulating member 72 in the direction of the first side when the protruding portion 71 contacts the regulating member 72, thereby suppressing its movement to the second side.

[0092] Furthermore, the cylindrical portion 631 and bottom portion 632 of the pressing member 63 are positioned inside the second cylindrical portion 701 and conical portion 702 of the control valve 70, and the diameter of the outer circumference of the flange portion 633 of the pressing member 63 is less than or equal to the outer diameter of the cylindrical portion 701 of the control valve 70. Therefore, the pressing member 63 is less susceptible to the force of the oil flowing through the back pressure passage 77 toward the second opening 67H2. As a result, the movement of the pressing member 63 toward the second side is suppressed, making it easier for it to remain stably in the normal operating position, and making it less likely for the pressing member 63 to be pressed against the cap portion 67, which is the abnormal operating position.

[0093] Thus, in the damping force generating device 100 according to this embodiment, even if the combined force of the oil moving the control valve 70 to the second side and the force of the coil spring 64 exceeds the thrust of the solenoid section 62 under normal conditions, the pressing member 63 is unlikely to be pressed against the cap section 67. In other words, in the damping force generating device 100, under normal conditions, unlike abnormal operation, the pressing member 63 is unlikely to be pressed against the cap section 67. As a result, the damping force generating device 100 can prevent abnormal operation from occurring even though the mechanism is capable of normal operation, and can perform abnormal operation if an abnormality occurs in the mechanism. Furthermore, even if the cross-sectional area of ​​the flow path 67R2 of the cap orifice flow path is changed to adjust the damping force generated under abnormal conditions, this change can be made so as not to affect the damping force under normal conditions.

[0094] As described above, the damping force generating device 100 includes a main valve 51 (an example of a main valve) that restricts the flow of oil (an example of a fluid) and generates a damping force, a back pressure chamber 68P that applies pressure to the main valve 51 in the closing direction, and a flow path (hereinafter sometimes referred to as the "discharge flow path") that allows oil to flow out from the back pressure chamber 68P. The discharge flow path is a flow path that passes through the back pressure communication passage 79, the communication chamber 78, the back pressure flow path 77, the second opening 67H2, the cap flow path 67R, and the housing internal flow path 111. The damping force generating device 100 also includes a valve 700 provided on the discharge flow path, which has a control valve 70 (an example of a valve body) that varies the area of ​​the discharge flow path and a control seat 76 (an example of a valve seat) on which the control valve 70 can seat. The damping force generating device 100 also includes a pressing member 63 that can contact the side of the control valve 70 opposite to the side facing the control seat 76 and can apply a pressing force in the direction that presses the control valve 70 against the control seat 76. Furthermore, the damping force generating device 100 includes a solenoid section 62, which is an example of an actuator section capable of generating a thrust that positions the device between a first position and a second position in accordance with the supplied current. The first position can be exemplified as the position shown in Figure 7, where the pressing member 63 is closest to the control seat 76. The second position can be exemplified as the position shown in Figure 9, where the pressing member 63 is furthest from the control seat 76. If the damping force generating device 100 does not include a regulating member 72, then when the pressure of the oil passing through the back pressure passage 77 is high, even when the pressing member 63 is in the second position shown in Figure 9, the control valve 70 will be in a state where the second end face of the cylindrical section 701 is in contact with the flange section 633 of the pressing member 63. In this state, that is, when the pressing member 63 is in the second position shown in Figure 9, the position of the control valve 70 in which the second end face of the cylindrical portion 701 is in contact with the flange portion 633 of the pressing member 63 is virtually referred to as the second position of the control valve 70. The solenoid portion 62 applies thrust to the pressing member 63 and presses it from the second position toward the first position.Furthermore, the damping force generating device 100 includes a restricting member 72 that restricts the movement of the control valve 70 so that the pressing member 63 does not reach the second position, even if the control valve 70 moves in a direction that moves the pressing member 63 toward the second position due to the pressure of the oil passing through the discharge passage. In other words, the damping force generating device 100 has a housing that is formed in a cylindrical shape and has a projection formed on its inner circumferential surface, which houses the pressing member 63 and the control valve 70. To put it another way, an object composed of a cap portion 67, a first spacer member 73A and a second spacer member 73B (an example of a pair of spacers), etc., is formed in a cylindrical shape that houses the pressing member 63 and the control valve 70, and the restricting member 72 protrudes two inward from the inner circumferential surfaces of the first spacer member 73A and the second spacer member 73B. The restricting member 72 and the projection 71 of the control valve 70 function as an example of a restricting portion that restricts the movement of the control valve 70 toward the second position at a third position between the first and second positions. The third position can be exemplified by the position shown in Figure 9, where the protruding portion 71 of the control valve 70 abuts against the regulating member 72.

[0095] According to the damping force generating device 100, under normal conditions, even if the oil pressure passing through the back pressure passage 77 is high and the control valve 70 moves to the second side, causing the pressing member 63 to move to the second side, the movement of the control valve 70 is restricted by the regulating member 72, so that the pressing member 63 does not reach the position furthest from the control seat 76. The pressing member 63 reaches the position furthest from the control seat 76 only in abnormal conditions when the current supplied to the solenoid section 62 is 0, in other words, when the solenoid section 62 is de-energized and the thrust of the solenoid section 62 is 0. Therefore, according to the damping force generating device 100, even if the oil pressure passing through the back pressure passage 77 is high under normal conditions when the mechanism is able to operate normally, abnormal operation is suppressed.

[0096] Furthermore, the damping force generating device 100 is further equipped with a coil spring 64 (an example of a moving member) that generates a force on the pressing member 63 in a direction away from the control valve 70, and moves the pressing member 63 to a second position when the movement of the control valve 70 is restricted by the restricting member 72. This makes it possible to press the pressing member 63 against the cap portion 67 with high accuracy in the event of an abnormality where the thrust of the solenoid portion 62 becomes zero. Therefore, if an actual abnormality occurs in the mechanism, the abnormal operation can be performed with high accuracy.

[0097] The coil spring 64 is an example of an elastic member positioned between the control valve 70 and the pressing member 63. Therefore, the damping force adjustment section 60 can be made into a simple configuration. The pressing member 63 is fixed to the plunger 65 (an example of a drive member) of the solenoid section 62. Therefore, the damping force can be adjusted with high accuracy according to the current supplied to the solenoid section 62, for example, by being able to press the pressing member 63 against the cap section 67 with high accuracy when the thrust of the solenoid section 62 becomes zero.

[0098] The pressing member 63 has a cylindrical portion 631 (an example of a cylindrical portion), a bottom portion 632 that covers the opening on the control seat 76 side of the cylindrical portion 631, and a flange portion 633 (an example of an applying portion) that protrudes from the outer circumferential surface of the cylindrical portion 631 to the second outside (an example of the outside) and applies a pressing force to the control valve 70. The control valve 70 accommodates the cylindrical portion 631 and the bottom portion 632 of the pressing member 63. Therefore, the pressing member 63 is less susceptible to the pressure of the oil passing through the back pressure passage 77. As a result, even if the pressure of the oil passing through the back pressure passage 77 is high under normal conditions, the movement of the pressing member 63 to the second side is suppressed, making it easier for it to remain stably in the normal operating position and suppressing abnormal operation.

[0099] Furthermore, the damping force adjustment section 60, as an example of a damping force adjustment device, comprises a control valve 70 provided on a fluid flow path and varying the area of ​​the flow path, and a case member housing the control valve 70 and having a control seat 76 (an example of a valve seat) in which a back pressure flow path 77 (an example of a through hole) that can be closed by the control valve 70 is formed. The case member is composed of the control seat 76, a cap portion 67, a first spacer member 73A, a second spacer member 73B, a third spacer member 73C, etc. The damping force adjustment section 60 also comprises a solenoid portion 62 that applies thrust to a pressing member 63 (an example of a movable member) that can contact the side of the control valve 70 opposite to the side facing the control seat 76, and a coil spring 64 (an example of a first spring member) with one end in contact with the control valve 70 and the other end in contact with the pressing member 63. Furthermore, the damping force adjustment section 60 includes a plate-shaped biasing member 75 (an example of a second spring member) whose one end contacts the control valve 70 and whose other end is fixed to a case member (for example, between the first spacer member 73A and the third spacer member 73C).

[0100] According to the damping force adjustment unit 60, when the pressing member 63 to which the thrust of the solenoid unit 62 is applied contacts the control valve 70, in the region from when the pressing member 63 and the control valve 70 are separated by the action of the coil spring 64 until they make contact, the biasing member 75 is stiffer than the coil spring 64. Therefore, the second axial position of the control valve 70 does not change, and the solenoid thrust is used only to deform the coil spring 64. In other words, the solenoid thrust is not used for anything else, and there is little wasted thrust efficiency in the solenoid unit 62.

[0101] Furthermore, the pressing member 63 has a flange portion 633 (an example of a restricting portion) that restricts the flow path from the second opening 67H2, the cap flow path 67R, and the housing internal flow path 111, which are downstream of the control valve 70, to the reservoir chamber R, and the other end of the coil spring 64 is in contact with the flange portion 633. Therefore, for example, in the event of an abnormality, the pressing member 63 can be pressed against the cap portion 67 with a high degree of accuracy.

[0102] <Second Embodiment> Figure 11 shows an example of a schematic configuration of the damping force generating device 200 according to the second embodiment. The damping force generating device 200 according to the second embodiment differs from the damping force generating device 100 according to the first embodiment in that it has a control valve 270 corresponding to the control valve 70 and a regulating member 272 corresponding to the regulating member 72. The differences from the first embodiment will be described below. The same reference numerals are used for the same parts in the first and second embodiments, and their detailed descriptions will be omitted.

[0103] The restricting member 272 differs from the restricting member 72 in that it does not have an arm portion 722, and only has a portion corresponding to the annular portion 721. Furthermore, the inner diameter of the restricting member 272 is smaller than the inner diameters of the first spacer member 73A and the second spacer member 73B, and the restricting member 272 protrudes two positions inward from the first spacer member 73A and the second spacer member 73B.

[0104] The control valve 270 differs from the control valve 70 in that its projection 271 is equivalent to the projection 71. Unlike the projection 71, the projection 271 is not formed around the entire circumference, but rather multiple projections (for example, four) are formed around the cylindrical portion 701. The multiple projections 271 are arranged at equal intervals in the circumferential direction of the cylindrical portion 701. The circumferential size of the projections 271 gradually decreases from the second inner to the second outer. The diameter of the virtual circle formed by the second outer tips of the multiple projections 271 is larger than the inner diameter of the regulating member 272 and smaller than the inner diameters of the first spacer member 73A and the second spacer member 73B.

[0105] In the damping force generating device 200 configured as described above, even if the control valve 270 moves to the second side due to the pressure of the oil passing through the back pressure passage 77, the movement of the control valve 270 to the second side is suppressed by the protrusion 271 contacting the regulating member 272.

[0106] As described above, the damping force generating device 200 is provided on the back pressure passage 77 and includes a conical portion 702 (an example of a valve body) of a control valve 270 that varies the area of ​​the back pressure passage 77 and a control valve 270 The damping force generating device 200 includes a valve 700 having a control seat 76 (an example of a valve seat) on which a pressure member can be seated. Furthermore, even if the control valve 270 moves in a direction that moves the pressure member 63 toward the second position due to the pressure of the oil passing through the back pressure passage 77, the damping force generating device 200 includes a protrusion 271 that restricts the movement of the control valve 270 so that the pressure member 63 does not reach the second position. In other words, the damping force generating device 200 has a cylindrical housing that accommodates the pressure member 63 and the control valve 270, and has a projection formed on its inner circumferential surface. To put it another way, the cap portion 67, the first spacer member 73A, and the second spacer member 73B are formed in a cylindrical shape that accommodates the pressure member 63 and the control valve 270, and the restricting member 272 protrudes two inward from the inner circumferential surfaces of the first spacer member 73A and the second spacer member 73B. Furthermore, the regulating member 272 and the protruding portion 271 of the control valve 270 function as an example of a regulating member that restricts the movement of the conical portion 702 of the control valve 270 toward the second position at a third position between the first and second positions. With the damping force generating device 200 configured in this way, even if the oil pressure passing through the back pressure passage 77 is high during normal operation when the mechanism is functioning normally, abnormal operation is suppressed.

[0107] <Third Embodiment> Figure 12 shows an example of a schematic configuration of the damping force generating device 400 according to the third embodiment. Figure 13 shows an example of a partial cross-section of the damping force generating device 400 according to the third embodiment. The damping force generating device 400 according to the third embodiment differs from the damping force generating device 100 according to the first embodiment in that it has a damping force adjustment unit 460 that corresponds to the damping force adjustment unit 60. The differences from the first embodiment will be described below. The same reference numerals are used for the same parts in the first and third embodiments, and their detailed descriptions will be omitted.

[0108] The damping force adjustment unit 460 according to the third embodiment differs from the damping force adjustment unit 60 according to the first embodiment in that it has a control sheet 476 which corresponds to the control sheet 76. Also, the damping force adjustment unit 460 differs from the damping force adjustment unit 60 in that it does not have a third spacer member 73C, and the biasing member 75 is fixed by the first spacer member 73A and the control sheet 476.

[0109] The control seat 476 has a first recess 481 that is annularly recessed to the first side of the fixing portion 471 and a second recess 482 that is annularly recessed to the first side of the fixing portion 471, between the fixing portion 471, which is the portion that fixes the biasing member 75 in the second radial direction, and the round 77R on which the control valve 70 can be seated. A first edge portion 491 is formed on the edge of the second side opening of the first recess 481, and a second edge portion 492 is formed on the edge of the second side opening of the second recess 482. The first edge portion 491 is located slightly to the second side of the fixing portion 471, and the second edge portion 492 is the connection portion between the first recess 481 and the second recess 482.

[0110] Figure 14 shows an example of a state in which the biasing member 75 is in contact with the first edge 491 but not with the second edge 492. Figure 15 shows an example of a state in which the biasing member 75 is in contact with the first edge 491 and the second edge 492. Figure 16 shows an example of the state in which the control valve 70 is seated on the round 77R.

[0111] When the current supplied to the coil of the solenoid unit 62 is a low current, the first current, as shown in Figure 13, the control valve 70 receives a force from the biasing member 75 toward the second side, and the spring force of the coil spring 64, the spring force of the biasing member 75, and the solenoid thrust are balanced. Not limited to this third embodiment, as mentioned above, when the current supplied to the coil of the solenoid unit 62 is between zero and the first current, the solenoid thrust is entirely used to deform the coil spring 64, resulting in good thrust efficiency. In this state, the biasing member 75 does not bend, and the flat surface 707 of the control valve 70 and the biasing member 75 are in surface contact. When the current supplied to the solenoid section 62 becomes a second current which is greater than the first current, the biasing member 75 is pushed by the control valve 70 and bends so as to contact the first edge 491 of the control seat 476, as shown in Figure 14. When the current supplied to the solenoid section 62 becomes a third current, which is greater than the second current, the biasing member 75 is pushed by the control valve 70 and bends further, as shown in Figure 15, and comes into contact with the first edge 491 and the second edge 492 of the control seat 476. When the current supplied to the solenoid section 62 becomes a fourth current, which is greater than the third current, the biasing member 75 is pushed by the control valve 70 and bends further, as shown in Figure 16, causing the control valve 70 to seat on the round 77R.

[0112] In other words, the current supplied to the solenoid section 62 when the biasing member 75 begins to contact the first edge 491 is the second current, and the current supplied to the solenoid section 62 when the biasing member 75 begins to contact the second edge 492 is the third current. Also, the current supplied to the solenoid section 62 when the control valve 70 begins to seat on the round 77R is the fourth current.

[0113] Figure 17 shows an example of the correlation between the current supplied to the solenoid unit 62 and the thrust F of the solenoid unit 62 (see Figures 14 to 16), the spring constant K of the biasing member 75, and the opening amount A of the control valve 70 (see Figures 14 and 15). The biasing member 75 bends starting from the first edge 491 when the current supplied to the solenoid 62 is between the second current and the third current, and bends starting from the second edge 492 when the current supplied to the solenoid 62 is between the third current and the second current. Therefore, as shown in Figure 17, the spring constant K2 of the biasing member 75 is substantially larger when it bends starting from the second edge 492 than when it bends starting from the first edge 491. In this way, the biasing member 75 changes such that the spring constant K substantially increases as the control valve 70 moves toward the round 77R (an example of a valve seat). Furthermore, when the current supplied to the solenoid section 62 is between the third current and the fourth current, the change in the valve opening amount A in response to an increase in the supply current (in other words, an increase in the thrust F of the solenoid section 62) is smaller than the change in the valve opening amount A in response to an increase in the supply current when the current supplied to the solenoid section 62 is between the second current and the third current. Therefore, when the current supplied to the solenoid section 62 is between the third current and the fourth current, the sensitivity of the actual position of the control valve 70 (in other words, the valve opening amount) to the supply current can be reduced compared to when the supply current is between the second current and the third current. Also, as mentioned above, even if the biasing member 75 is made of something other than a leaf spring, by using, for example, an unequal pitch coil spring, it is possible to configure it so that the spring constant K changes substantially as the control valve 70 moves toward the round 77R (an example of a valve seat).

[0114] As described above, in the damping force adjustment unit 460 according to the third embodiment, the control seat 476 has a first recess 481 that is annularly recessed toward the round 77R side, second inward from the fixing portion 471 of the biasing member 75, and a second recess 482 that is annularly recessed toward the round 77R side, further inward from the first recess 481. The biasing member 75 does not contact the first edge portion 491, which is the edge of the first recess 481, or the second edge portion 492, which is the edge of the second recess 482, when the amount of movement of the control valve 70 toward the round 77R side is less than or equal to a first predetermined value. The amount of movement of the control valve 70 toward the round 77R side is based on the position where the movement of the control valve 70 toward the second side is restricted by the restricting member 72. The first predetermined value is the distance from the reference point to the position where the current supplied to the solenoid section 62 is the first current, and the spring force of the coil spring 64 and the spring force of the biasing member 75 are balanced without the biasing member 75 bending significantly. Furthermore, if the amount of movement of the control valve 70 toward the first side is greater than the first predetermined value and less than the second predetermined value, the biasing member 75 contacts the first edge 491 but not the second edge 492. In other words, if the current supplied to the solenoid section 62 is greater than or equal to the second current and less than the third current, the biasing member 75 contacts the first edge 491 but not the second edge 492. Also, if the amount of movement of the control valve 70 toward the first side is greater than or equal to the second predetermined value, the biasing member 75 contacts both the first edge 491 and the second edge 492. In other words, when the current supplied to the solenoid section 62 is the third current or higher, the biasing member 75 contacts the first edge 491 and the second edge 492. The second predetermined value is the distance from the reference to the position of the control valve 70 when the current supplied to the solenoid section 62 is the third current and the biasing member 75 begins to contact the second edge 492. With the damping force adjustment section 460 configured as described above, the spring constant K of the biasing member 75 can be changed in steps, and the damping force can be adjusted finely.

[0115] Here, as shown in Figure 12, the biasing member 75 has an annular portion 751 as an example of a fixed portion that serves as a fixed end, and arm portions 752 as an example of a plurality of working portions that extend from the annular portion 751 toward the control valve 70 and simultaneously contact the control valve 70. As a result, even when the biasing member 75 is applying force to the control valve 70, it is possible to form a flow path between adjacent arm portions 752 from the back pressure flow path 77 toward the second opening 67H2.

[0116] In the damping force adjustment unit 460 according to the third embodiment, a first recess 481 and a second recess 482 are formed in the control sheet 476, but the invention is not limited to this configuration. Similar to the damping force adjustment unit 60 according to the first embodiment, a third spacer member 73C may be provided between the control sheet 476 and the biasing member 75 to form a first recess 481 that is recessed to the first side from the contact portion with the biasing member 75.

[0117] Furthermore, the position in the second axial direction of the first edge 491, which is the starting point for the deflection of the biasing member 75, is the same over the entire circumference, but the invention is not limited to this configuration. The first recess 481 may be formed such that the position in the second axial direction of the first edge 491 differs in steps or continuously along the circumferential direction. Similarly, the first recess 481 may be formed such that the position in the second radial direction of the first edge 491 differs in steps or continuously along the circumferential direction. This makes it possible to change the spring constant K1 when the biasing member 75 deflects starting from the first edge 491 in steps or continuously. In other words, the size of the recess in the second axial direction and the position in the second radial direction of the first recess 481 do not have to be uniform.

[0118] Similarly, the position in the second axial direction of the second edge 492, which is the starting point for the deflection of the biasing member 75, is the same around the entire circumference, but the invention is not limited to this configuration. The second recess 482 may be formed such that the position in the second axial direction of the second edge 492 differs in steps or continuously along the circumferential direction. Similarly, the second recess 482 may be formed such that the position in the second radial direction of the second edge 492 differs in steps or continuously along the circumferential direction. This makes it possible to change the spring constant K2 when the biasing member 75 deflects starting from the second edge 492 in steps or continuously. In other words, the size of the recess in the second axial direction and the position in the second radial direction of the second recess 482 do not have to be uniform. [Explanation of Symbols]

[0119] 1... Hydraulic shock absorber, 10... Cylinder section, 11... Cylinder, 20... Rod, 30... Piston section, 51... Main valve (example of main valve), 60, 460... Damping force adjustment section, 62... Solenoid section (example of actuator section), 63... Pressing member (example of movable member), 64... Coil spring (example of moving member, example of first spring member), 65... Plunger, 67... Cap section (example of case member), 68P... Back pressure chamber, 70... Control 72... Regulating member (example of regulating part), 75... Biasing member (example of second spring member), 76, 476... Control seat (example of valve seat, example of case member), 77... Back pressure passage (example of passage), 77R... Round (example of valve seat), 100, 200, 400... Damping force generating device, 270... Control valve, 271... Protrusion (example of regulating part), 471... Fixing part, 481... First recess, 482... Second recess 491...First edge, 492...Second edge, 631...Cylindrical part, 632...Bottom, 633...Flange part (an example of a limiting part), 700...Valve, 702...Conical part (an example of a valve body), 751...Annular part (an example of a fixing part), 752...Arm part (an example of an action part)

Claims

1. A valve body provided on a fluid passage, which varies the area of ​​the passage, A case member having a valve seat that houses the valve body and has a through hole formed therein that can be closed by the valve body, An actuator unit that applies thrust to a movable member that can contact the side of the valve body opposite to the side facing the valve seat, A first spring member, one end of which contacts the valve body and the other end of which contacts the movable member, A second spring member, one end of which contacts the valve body and the other end which is fixed to the case member, Equipped with, The spring constant of the second spring member is greater than the spring constant of the first spring member. Damping force adjustment device.

2. The movable member has a limiting portion that restricts the flow path downstream of the valve body, The other end of the first spring member contacts the limiting portion. The damping force adjustment device according to claim 1.

3. The spring constant of the second spring member changes as the valve body moves toward the valve seat. The damping force adjustment device according to claim 1.

4. The second spring member is made of a leaf spring, and as the valve body moves toward the valve seat, the contact position with the case member changes, causing the spring constant to increase. The damping force adjustment device according to claim 3.

5. The case member has a first recess that is annularly recessed toward the valve seat side, located inside the fixing portion of the second spring member, and a second recess that is annularly recessed toward the valve seat side, located inside the first recess. The second spring member does not contact the first edge, which is the edge of the first recess, and the second edge, which is the edge of the second recess, when the amount of movement of the valve body toward the valve seat is less than or equal to a first predetermined value; when the amount of movement is greater than the first predetermined value and less than the second predetermined value, it contacts the first edge and does not contact the second edge; and when the amount of movement is greater than or equal to the second predetermined value, it contacts the first edge and the second edge. The damping force adjustment device according to claim 1.

6. The second spring member has a fixed end portion and one or more working portions that extend from the fixed end toward the valve body and contact the valve body. The damping force adjustment device according to claim 5.

7. The second spring member has the first edge and the second edge with the acting portion in contact with them. The damping force adjustment device according to claim 6.

8. A piston portion is inserted into a cylinder containing a fluid and is movable relative to the cylinder, A damping force adjustment device according to any one of claims 1 to 7, which adjusts the damping force generated by utilizing the fluid flow produced as a result of the movement of the piston portion, A shock absorber equipped with a shock absorber.

Images