Damping force adjusting device and buffer device

Abstract

A damping force adjustment device is provided with: a control valve (70) which is provided in a flow path through which a fluid flows and which varies the area of the flow path; a housing member that houses the control valve (70) and has a control valve seat (76) in which a through-hole that can be closed by the control valve (70) is formed; a solenoid unit that applies a thrust force to a pressing member (63) that can come into contact with a side of the control valve (70) opposite to a side facing the control valve seat (76); a coil spring (64), one end of which is in contact with the control valve (70) and the other end of which is in contact with the pressing member (63); and a biasing member (75), one end of which is in contact with the control valve (70) and the other end of which is fixed to the housing member.

Description

Technical Field

[0001] The invention relates to a damping force adjusting device and a buffering device. Background Art

[0002] For example, the damping valve described in Patent Document 1 includes a valve core component comprising a pressure control valve core that is seated relative to a pressure control valve seat and an on-off valve core that is seated relative to an on-off valve seat. These components are used to open and close the upstream and downstream sides of a pilot passage. Furthermore, the damping valve described in Patent Document 1 includes a disc spring interposed between a step and the valve core component, which biases the valve core component in a direction that moves the pressure control valve core away from the pressure control valve seat and the on-off valve core toward the on-off valve seat; and a solenoid that can drive the valve core component against the bias of the disc spring. Furthermore, a damping valve is described in which current is supplied to the solenoid, causing thrust to act on the valve core component, thereby pressing the pressure control valve core of the valve core component against the pressure control valve seat against the bias of the disc spring.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application No. 2011-525962 Summary of the Invention

[0006] Problems to be solved by the invention

[0007] In the damping valve described in Patent Document 1, when current is supplied to the solenoid, causing thrust to act on the valve core member, the solenoid thrust deforms the first spring and is also transmitted to the valve housing via the first spring. In other words, the limited solenoid thrust is transmitted to parts that are not required for operation, leaving room for improvement.

[0008] An object of the present invention is to provide a damping force adjustment device and the like that reduces waste of thrust of an actuator unit and has good thrust efficiency.

[0009] Means for solving problems

[0010] The present invention, which has been completed based on this purpose, is a damping force adjustment device comprising: a valve core, which is arranged in a flow path for fluid flow so that the area of ​​the flow path is variable; a shell component, which accommodates the valve core and has a valve seat formed with a through hole that can be closed by the valve core; an actuator part, which applies thrust to a movable component, which can contact the side of the valve core opposite to the side opposite to the valve seat; a first spring component, one end of which contacts the valve core and the other end of which contacts the movable component; and a second spring component, one end of which contacts the valve core and the other end of which is fixed to the shell component.

[0011] Effects of the Invention

[0012] According to the present invention, the thrust efficiency of the actuator unit can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 This is a diagram showing an example of a schematic configuration of a hydraulic shock absorber according to the first embodiment.

[0014] Figure 2 This is a diagram showing an example of a cross section of the damping force generating device according to the first embodiment.

[0015] Figure 3 It is a diagram showing an example of a perspective cross section of the main valve portion and the damping force adjustment portion according to the first embodiment.

[0016] Figure 4 This is a diagram showing an example of a partial cross section of the main valve portion and the damping force adjustment portion according to the first embodiment.

[0017] Figure 5 This is a diagram showing an example of the flow of oil when the pressing force of the pressing member is minimized and the moving speed of the piston is low.

[0018] Figure 6 This is a diagram showing an example of the flow of oil when the pressing force of the pressing member is minimized and the moving speed of the piston is high.

[0019] Figure 7 This is a diagram showing an example of the flow of oil when the pressing force of the pressing member is maximized and the moving speed of the piston is low.

[0020] Figure 8 This is a diagram showing an example of the flow of oil when the pressing force of the pressing member is maximized and the moving speed of the piston is high.

[0021] Figure 9 This is a diagram showing an example of the flow of oil when the solenoid portion is in a non-energized state and the moving speed of the piston portion is low.

[0022] Figure 10 This is a diagram showing an example of the flow of oil when the solenoid portion is in a non-energized state and the piston portion moves at a high speed.

[0023] Figure 11 This is a diagram showing an example of a schematic configuration of a damping force generating device according to a second embodiment.

[0024] Figure 12 This is a diagram showing an example of a schematic configuration of a damping force generating device according to a third embodiment.

[0025] Figure 13 This is a diagram showing an example of a partial cross section of a damping force generating device according to a third embodiment.

[0026] Figure 14 This is a diagram showing an example of a state in which the urging member is in contact with the first edge portion but is not in contact with the second edge portion.

[0027] Figure 15 This is a diagram showing an example of a state in which the urging member is in contact with the first edge portion and the second edge portion.

[0028] Figure 16 This is a diagram showing an example of a state in which the control valve is seated on a circle portion.

[0029] Figure 17 This is a diagram showing an example of the correlation between the current supplied to the solenoid portion, the thrust of the solenoid portion, the spring constant of the urging member, and the valve opening amount of the control valve. DETAILED DESCRIPTION

[0030] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0031] <First embodiment>

[0032] [Structure and Function of Hydraulic Shock Absorber 1]

[0033] Figure 1 This is a diagram showing an example of a schematic configuration of the hydraulic shock absorber 1 according to the first embodiment.

[0034] like Figure 1 As shown, the hydraulic shock absorber 1 includes a cylinder 10 that contains oil, and a rod 20, one side of which is slidably inserted into the cylinder 10 and the other side of which protrudes from the cylinder 10. The hydraulic shock absorber 1 also includes a piston 30 provided at one end of the rod 20 and a bottom 40 provided at one end of the cylinder 10. Furthermore, the hydraulic shock absorber 1 includes a damping force generator 100 provided outside the cylinder 10 to generate a damping force.

[0035] In addition, in the following description, Figure 1 The longitudinal direction of the cylinder portion 10 shown is referred to as the "axial direction". Figure 1 The lower side of is called "one side", Figure 1 The upper side of is called "the other side". Figure 1 The left-right direction of the cylinder portion 10 shown is referred to as the “radial direction”. In the radial direction, the central axis side of the cylinder portion 10 is referred to as the “inner side”, and the side farther from the central axis is referred to as the “outer side”.

[0036] The cylinder portion 10 includes a cylinder 11 that stores oil, an outer cylindrical body 12 provided outside the cylinder 11 , and a damper housing 13 provided outside the cylinder 11 and further outside the outer cylindrical body 12 .

[0037] The cylinder 11 is formed in a cylindrical shape, and a communication hole 11H for communicating the inside and the outside is formed at the other end portion.

[0038] The outer cylinder 12 is cylindrical. It forms a communication path L with the cylinder 11. The outer cylinder 12 also has an outer cylinder opening 12H and an outer connecting portion 12J at a position facing the damping force generator 100. The outer connecting portion 12J provides an oil flow path and protrudes outward, forming a connection point with the damping force generator 100.

[0039] The damper housing 13 is cylindrical. A reservoir R for storing oil is formed between the damper housing 13 and the outer cylinder 12. The reservoir R absorbs oil from the cylinder 11 or supplies oil to the cylinder 11 as the rod 20 moves relative to the cylinder 11. The reservoir R also stores oil flowing out of the damping force generator 100. The damper housing 13 also has a housing opening 13H at a position facing the damping force generator 100.

[0040] The rod 20 is a rod-shaped member extending long in the axial direction. The rod 20 holds the piston portion 30 on one side. In addition, the rod 20 is connected to the vehicle body, for example, via a connecting member (not shown) on the other side.

[0041] The piston unit 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 disposed between the piston valve 32 and one end of the rod 20. Furthermore, the piston unit 30 divides the oil in the cylinder 11 into a first oil chamber Y1 and a second oil chamber Y2.

[0042] 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 defines the first oil chamber Y1 and the reservoir chamber R.

[0043] [Structure and Function of Damping Force Generator 100]

[0044] Figure 2 This is a diagram showing an example of a cross section of the damping force generator 100 according to the first embodiment.

[0045] Figure 3 1 is a diagram showing an example of a perspective cross section of the main valve portion 50 and the damping force adjustment portion 60 according to the first embodiment.

[0046] Figure 4This is a diagram showing an example of a partial cross section of the main valve portion 50 and the damping force adjustment portion 60 according to the first embodiment.

[0047] In the following descriptions, sometimes Figure 2 The longitudinal direction of the damping force generating device 100 shown (ie, the longitudinal direction of the cylinder portion 10 (refer to Figure 1 ) is referred to as the "second axial direction". In addition, sometimes the central axis side of the cylinder portion 10 (in the second axial direction) is referred to as the "second axial direction". Figure 2 The left side of the damping force generating device 100 is referred to as the “first side”, and the side away from the central axis of the cylinder 10 (the side Figure 2 The right side of the damping force generating device 100 is referred to as the “second side”.

[0048] In addition, sometimes Figure 2 The short-side direction of the damping force generating device 100 (i.e., the direction intersecting the second axial direction) is referred to as the "second radial direction." Furthermore, in the second radial direction, the side along the central axis of the second axis is sometimes referred to as the "second inner side," and the side farther from the central axis along the second axis is sometimes referred to as the "second outer side."

[0049] like Figure 2 As shown, the damping force generator 100 includes the main valve portion 50, which primarily generates damping force in the hydraulic shock absorber 1 of the first embodiment, and a damping force adjustment portion 60, which adjusts the magnitude of the damping force generated by the damping force generator 100. Furthermore, the damping force generator 100 includes a communication portion 80, which forms a parallel flow path with the main valve portion 50; a connecting flow path portion 90, which forms a flow path for oil from the communication path L to the main valve portion 50 and the communication portion 80; and an outer housing 100C, which houses the various components that constitute the damping force generator 100.

[0050] (Main valve portion 50)

[0051] The main valve portion 50 includes a main valve 51 that generates a damping force by controlling the flow of oil to throttle it, and a main valve seat 52 that faces the main valve 51 and contacts the main valve 51 .

[0052] like Figure 3 As shown in FIG, the main valve 51 is a disc-shaped member having an opening 51H on the second inner side and elastically deformable. The main valve 51 can be made of a metal such as iron, for example.

[0053] And, as Figure 4 As shown, the communication 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 a spacer 684 (described later) on the second inner side.

[0054] The main valve 51, constructed as described above, is restricted from moving in the second radial direction by the connecting portion 80. Furthermore, movement of the second inner side of the main valve 51 in the second axial direction is restricted by the main valve seat 52 and the spacer member 684 (described later). Meanwhile, the second outer side of the main valve 51 is capable of moving in the second axial direction by deformation. Furthermore, the main valve 51 throttles the flow of oil in the main flow passage 53 (described later) of the main valve seat 52, generating a damping force.

[0055] Next, the main valve seat 52 will be described.

[0056] like Figure 3 As shown, the main valve seat 52 is a cylindrical member having an opening 52H on the second inner side. In addition, the main valve seat 52 has a communication portion 80 (see FIG. 1 ) inserted into a portion of the opening 52H. Figure 4 ).

[0057] The main valve seat 52 has a central valve seat portion 520 surrounding the opening 52H. The main valve seat 52 also has an inner valve seat portion 521 located second outside of the central valve seat portion 520, and an outer valve seat portion 522 located second outside of the inner valve seat portion 521. Furthermore, the main valve seat 52 has a main flow path 53 extending in the second axial direction on the second outside of the opening 52H.

[0058] The central valve 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 valve seat portion 520 .

[0059] The inner valve seat portion 521 is formed in an annular shape and protrudes further than the flow passage 532 toward the main valve 51 . The protruding height of the inner valve seat portion 521 is substantially equal to that of the central valve seat portion 520 and the outer valve seat portion 522 .

[0060] The outer valve seat portion 522 is formed in an annular shape and protrudes further than the flow passage 532 toward the main valve 51 .

[0061] The inner valve seat portion 521 and the outer valve seat portion 522 form a contact portion with the main valve 51 .

[0062] Furthermore, the inner valve seat portion 521 has multiple grooves 521T formed along the second radial direction. Each groove 521T has a relatively small flow path cross-sectional area. In other words, the grooves 521T constitute a so-called orifice flow path. When the main valve 51 is in contact with the inner valve seat portion 521, each groove 521T forms a flow path that allows oil to flow from the second inner side of the inner valve seat portion 521 to the second outer side of the inner valve seat portion 521.

[0063] The main flow path 53 forms a parallel flow path with respect to the back pressure flow path 77 of the control valve seat 76 described later (see Figure 4 ). In addition, the main flow path 53 is provided with a plurality of circumferential directions (refer to Figure 3 ). Furthermore, the flow passage opening 531 on the first side of each main flow passage 53 communicates with the opening 52H and faces the connecting flow passage portion 90. Furthermore, the flow passage opening 532 on the second side of each main flow passage 53 is located between the central valve seat portion 520 and the inner valve seat portion 521.

[0064] (Damping Force Adjustment Unit 60)

[0065] like Figure 2 As shown, the damping force adjustment unit 60 includes an advancing / retracting portion 61 that advances and retracts a control valve 70 (described later) relative to a control valve seat 76; a cover portion 67 that covers various components, including the main valve portion 50; and a back pressure generating mechanism 68 that changes the ease with which the main valve 51 can deform relative to the main valve seat 52. Furthermore, the damping force adjustment unit 60 includes a control valve 70 that throttles the flow of oil in the communication portion 80; a control valve seat 76 that opposes and contacts the control valve 70; and a throttle member 83 that throttles the flow of oil. Furthermore, the damping force adjustment unit 60 includes a restricting member 72 that restricts 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 a direction opposite to the thrust of the solenoid portion 62. The damping force adjustment portion 60 includes a first spacer 73A interposed between the urging member 75 and the limiting member 72 , a second spacer 73B interposed between the limiting member 72 and the lid portion 67 , and a third spacer 73C interposed between the control valve seat 76 and the urging member 75 .

[0066] ((Advance and Retreat Unit 61))

[0067] like Figure 2 As shown, the advancing and retracting portion 61 includes a solenoid portion 62 that uses an electromagnet to advance and retract a pressing member 63 (described later); the pressing member 63 that presses the control valve 70 against the control valve seat 76; and a coil spring 64 disposed between the pressing member 63 and the control valve 70. The advancing and retracting portion 61 also includes a solenoid housing 60C that houses and supports the components constituting the advancing and retracting portion 61.

[0068] The solenoid portion 62 includes a plunger 65 that moves forward and backward along the second axial direction. When the electromagnet is energized, the plunger 65 is pushed toward the first side. When the solenoid portion 62 is de-energized, the plunger 65 is pulled back toward the second side by the coil spring 64.

[0069] like Figure 4As shown, the pressing member 63 has: a cylindrical portion 631; a bottom 632, which covers the opening portion of the first side of the cylindrical portion 631; and a flange portion 633, which is provided at the end portion of the second side of the cylindrical portion 631 and protrudes toward the second outer side throughout the entire circumference.

[0070] The coil spring 64 is a compression coil spring that contacts the control valve 70 on its first side and contacts the pressing member 63 on its second side. The coil spring 64 applies a force to the pressing member 63 and the control valve 70, respectively, in a direction that separates the pressing member 63 and the control valve 70. Alternatively, other components, such as an elastic ring, may be used in place of the coil spring 64 as long as they provide the same function.

[0071] ((Cover 67))

[0072] like Figure 3 As shown, the cover portion 67 is a component having a first opening portion 67H1 formed on the first side and a second opening portion 67H2 formed on the second side, and having a basic cylindrical shape. In addition, the inner diameter of the first opening portion 67H1 is formed to be larger than the inner diameter of the second opening portion 67H2. Moreover, a plurality of inner diameter portions having different inner diameters are formed inside the cover portion 67. The inner diameter portion provided on the first side of the plurality of inner diameter portions is formed to have a larger inner diameter than the inner diameter portion provided on the second side. For example, the cover portion 67 has a first inner diameter portion 671 located closer to the first side than the second opening portion 67H2, a second inner diameter portion 672 located closer to the first side than the first inner diameter portion 671, and a third inner diameter portion 673 located closer to the first side than the second inner diameter portion 672.

[0073] And, as Figure 4 As shown, the cover portion 67 internally houses the main valve portion 50, the damping force adjustment portion 60, and the communication portion 80. More specifically, the cover portion 67 houses the main valve 51 and the control valve 70 of the main valve portion 50. Furthermore, a portion of the cover portion 67, together with the back pressure generating mechanism 68 and the control valve seat 76, forms a back pressure chamber 68P. This back pressure chamber 68P allows the pressure of the oil from a second side, opposite the main valve seat 52 (hereinafter sometimes referred to as "back pressure"), to act on the main valve 51.

[0074] like Figure 2 As shown, the cover 67 is fixed by being sandwiched between the solenoid case 60C and the connecting flow path portion 90. Furthermore, the cover 67 forms a cover flow path 67R between the cover 67 and the solenoid case 60C, through which oil flows. The cover flow path 67R communicates with the second opening 67H2 and with the in-case flow path 111, which will be described later.

[0075] The plunger 65 penetrates the second opening 67H2 provided in the cover 67. In addition, regarding the cover 67, the pressing member 63 moves forward and backward relative to the second opening 67H2 inside the cover 67.

[0076] Furthermore, a groove portion 675 is formed at the edge of the first side of the second opening portion 67H2 of the cover portion 67. When the pressing member 63 moves to the second side and contacts the cover portion 67, the groove portion 675 forms a cover orifice flow path 67R2 (see FIG. 1 ) for oil to flow between the flange portion 633 of the pressing member 63 and the cover portion 67. Figure 9 The cap orifice flow path 67R2 communicates with the cap flow path 67R via the second opening 67H2.

[0077] Furthermore, in the first embodiment, the cross-sectional area of ​​the oil flow path in the groove portion 675 is set so that the pressure in the back-pressure chamber 68P is increased to a certain value or higher when the solenoid portion 62 is in the de-energized state. Furthermore, the cross-sectional area of ​​the oil flow path in the groove portion 675 is set so that when the solenoid portion 62 is in the de-energized state, oil flows through the groove portion 675 to the extent that the main valve 51 opens the main flow path 53, thereby generating an oil flow.

[0078] The structure for generating the flow of oil between the cover 67 and the pressing member 63 when the solenoid portion 62 is in the de-energized state described above is not limited to the groove 675. For example, the pressing member 63 may be provided with a groove to allow the flow of oil between the pressing member 63 and the cover 67 when the pressing member 63 and the cover 67 are in contact. Alternatively, the groove 675 may be formed in the cover 67 and the groove may be provided in the pressing member 63. Furthermore, the structure for generating the flow of oil between the cover 67 and the pressing member 63 when the pressing member 63 and the cover 67 are in contact is not limited to a groove and may also be a through-hole.

[0079] ((Back pressure generating mechanism 68))

[0080] like Figure 3 As shown, the back pressure generating mechanism 68 includes a partition member 681 provided on the opposite side of the main valve seat 52 relative to the main valve 51, that is, on the second side; and a sealing member 682 that seals between the lid 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, pressing the partition member 681 against the main valve 51; and a spacer 684 interposed between the return spring 683 and the main valve 51.

[0081] The basic shape of the partition wall member 681 is formed into a substantially annular shape. The partition wall member 681 is movable in the second axial direction. For example, when the main valve 51 deforms toward the second side, the partition wall member 681 moves toward the second side. Alternatively, when the main valve 51 deforms toward the first side, the partition wall member 681 moves toward the first side.

[0082] Furthermore, the partition wall member 681 includes a main valve contact portion 681V that contacts the main valve 51 and a seal contact portion 681S where the seal member 682 is provided.

[0083] 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 toward the first side. This main valve contact portion 681V annularly contacts the main valve 51. Furthermore, the partition member 681 forms one of the components that form the backpressure chamber 68P.

[0084] Here, the back pressure chamber 68P is a chamber in which oil flows in and a hydraulic pressure corresponding to the inflowing oil acts on the main valve 51. The back pressure chamber 68P acts to apply a force to the main valve 51 to press the main valve 51 against the main valve seat 52.

[0085] like Figure 3 As shown in FIG, the sealing member 682 is formed in an annular shape. In addition, the sealing member 682 can be made of an elastically deformable resin material such as engineering plastics and rubber.

[0086] And, as Figure 4 As shown, the sealing member 682 seals between the bulkhead member 681 and the third inner diameter portion 673 of the cover portion 67. More specifically, the outer peripheral surface 682G of the sealing member 682 contacts the inner periphery of the third inner diameter portion 673 of the cover portion 67. Furthermore, the end surface 682T on the first side of the sealing member 682 contacts the bulkhead member 681. Thus, the sealing member 682 prevents the oil in the back-pressure chamber 68P from flowing out of the back-pressure chamber 68P through the space between the bulkhead member 681 and the cover portion 67.

[0087] like Figure 3 As shown, the return spring 683 includes an annular portion 683R formed in an annular shape and a plurality of arm portions 683A protruding from the annular portion 683R toward the second outer side.

[0088] And, as Figure 4 As shown, the connecting portion 80 passes through the annular portion 683R of the return spring 683 , and the annular portion 683R of the return spring 683 is sandwiched in the second axial direction by a plurality of spacer members 684 . Furthermore, the arm portion 683A of the return spring 683 contacts the sealing member 682 .

[0089] In the return spring 683, the position where the annular portion 683R is fixed by the spacer 684 and the position where the arm portion 683A contacts the sealing member 682 are different in the second axial direction. Furthermore, the arm portion 683A is tilted relative to the second axial direction. Furthermore, the arm portion 683A contacts the second inner corner of the sealing member 682. As a result, the arm portion 683A applies a spring force component along the second axial direction and a spring force component along the second radial direction to the sealing member 682.

[0090] Furthermore, the arm portion 683A of the return spring 683 of the first embodiment also contacts the partition wall member 681. The return spring 683 applies to the partition wall member 681 an elastic force having a component along the second axial direction and an elastic force having a component along the second radial direction.

[0091] ((Control valve 70))

[0092] The control valve 70 includes a cylindrical portion 701 and a conical portion 702. The conical portion 702 covers the opening on the first side of the cylindrical portion 701 and protrudes toward the first side. Furthermore, the control valve 70 includes a protrusion 71 at the end of the first side of the cylindrical portion 701, which protrudes throughout its entire circumference toward the second outer side. Furthermore, the control valve 70 includes a flat surface 703 perpendicular to the second axial direction at the end of the second side of the conical portion 702, on the second inner side. Furthermore, the control valve 70 includes a protrusion 706 at the center of the conical portion 702 in the second axial direction, which protrudes toward the second outer side. A flat surface 707 perpendicular to the second axial direction is formed on the protrusion 706.

[0093] The outer diameter of the cylindrical portion 701 is equal to or larger than the outer diameter of the flange portion 633 of the pressing member 63, and the inner diameter of the cylindrical portion 701 is smaller than the outer diameter of the flange portion 633. Thus, the second end surface of the cylindrical portion 701 contacts the flange portion 633 of the pressing member 63.

[0094] 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. Thus, with the second end surface of the cylindrical portion 701 in contact with the flange 633 of the pressing member 63, the cylindrical portion 631 and bottom portion 632 of the pressing member 63 are accommodated within the second inner side of the control valve 70. Furthermore, a coil spring 64 (an example of an elastic member) is disposed within 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, while the second end of the coil spring 64 is supported by the flange 633 of the pressing member 63. As a component that functions at both ends and has no fixed end, the thrust applied to the solenoid portion 62 of the coil spring 64 is entirely used to deform the coil spring 64 itself, resulting in high thrust efficiency.

[0095] ((Restriction member 72))

[0096] like Figure 3 As shown, the restricting member 72 includes an annular portion 721 formed in an annular shape and a plurality of arm portions 722 protruding from the annular portion 721 toward the second inner side. Four arm portions 722 are provided at equal intervals along the circumference of the annular portion 721. The circumferential size of the arm portions 722 gradually decreases as they move from the second outer side toward the second inner side. The diameter of the imaginary circle formed by the second inner side tips of the plurality of arm portions 722 is larger than the diameter of the outer circumference of the cylindrical portion 701 of the control valve 70 and smaller than the diameter of the outer circumference of the protruding portion 71.

[0097] ((First Spacer 73A, Second Spacer 73B, and Third Spacer 73C))

[0098] The first, second, and third spacers 73A, 73B, and 73C are annular members. The outer diameters of the first, second, and third spacers 73A, 73B, and 73C are larger than the inner diameter of the first inner diameter portion 671 of the cover 67, and smaller than the inner diameter of the second inner diameter portion 672. Furthermore, the inner diameters of the first, second, and third spacers 73A, 73B, and 73C are larger than the inner diameter of the first inner diameter portion 671 of the cover 67, and smaller than the inner diameter of the second inner diameter portion 672.

[0099] The first and second spacer members 73A, 73B are disposed between the first end surface of the first inner diameter portion 671 of the cover portion 67 and the biasing member 75, and define the second axial position of the restricting member 72. More specifically, the restricting member 72 is positioned toward the second side relative to the protruding portion 71 of the control valve 70, restricting movement of the control valve 70 toward the second side.

[0100] Furthermore, by adjusting the size (hereinafter sometimes referred to as "thickness") of the first spacing member 73A and the second spacing member 73B in the second axial direction, the position of the limiting member 72 in the second axial direction can be adjusted. Figure 4 In the case of the position closer to the first side, the thickness of the first spacer 73A can be made thicker than Figure 4 The thickness shown is thin, so that the thickness of the second spacing member 73B is smaller than Figure 4 On the other hand, when the second axial position of the limiting member 72 is set to Figure 4 In the case of the position closer to the second side, the thickness of the first spacer 73A can be made thicker than Figure 4 The thickness shown is thicker than that of the second spacer member 73B. Figure 4 The thickness shown is thin.

[0101] The third spacer 73C is disposed between the urging member 75 and the control valve seat 76 to determine the second axial position of the urging member 75. Furthermore, by adjusting the size (hereinafter sometimes referred to as "thickness") of the third spacer 73C in the second axial direction, the second axial position of the urging member 75 can be adjusted. For example, if the second axial position of the urging member 75 is to be set to a value smaller than Figure 4 In the case of the position closer to the first side, the thickness of the third spacer 73C can be made thicker than Figure 4 The thickness shown is thin, so that the thickness of the first spacing member 73A is smaller than Figure 4 On the other hand, when the second axial position of the force applying member 75 is set to be larger than Figure 4 In the case of the position closer to the second side, the thickness of the third spacer 73C can be made thicker than Figure 4 The thickness shown is thicker than that of the first spacer member 73A. Figure 4 The thickness shown is thin.

[0102] ((Force applying member 75))

[0103] The force-applying 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 elastic force of the coil spring 64. Its spring constant is set higher than that of the coil spring 64. The force-applying member 75 includes an annular portion 751, which is formed in an annular shape and serves as a fixed end; and multiple arms 752, which protrude from the annular portion 751 toward the second inner side and serve as active ends. The shape of the force-applying member 75 is not limited to this; as long as it has a fixed end and an active end that acts on the control valve 70, there is no particular limitation. For example, three arms 752 are provided at equal intervals along the circumference of the annular portion 751. However, the number of arms 752 is not limited to three and can be two or fewer or four or more. Furthermore, the shapes of the multiple arms 752 can all be identical or different. For example, the circumferential dimensions of the multiple arms 752 can also differ. Furthermore, the urging member 75 may not be a leaf spring but may be an elastic member such as a coil spring interposed between the control valve 70 and the control valve seat 76 .

[0104] ((Control valve seat 76))

[0105] The control valve seat 76 includes an outer valve seat portion 761, which, together with the lid portion 67, holds the restricting member 72, the biasing member 75, the first spacer 73A, the second spacer 73B, and the third spacer 73C. A recessed portion 762, provided on the second inner side and recessed from the second side surface of the outer valve seat portion 761, is provided. A backpressure flow path 77 is formed in the second inner side of the recessed portion 762. This backpressure flow path 77 is a hole extending through the recessed portion 762 in the second axial direction, forming an oil flow path for adjusting the oil pressure in the backpressure chamber 68P. The control valve seat 76 includes a circular portion 77R surrounding the backpressure flow path 77, which protrudes toward the second side from the bottom of the recessed portion 762.

[0106] The control valve seat 76 further includes a communication chamber 78, which is provided closer to the first side than the back-pressure flow path 77 and communicates with the back-pressure flow path 77. Furthermore, a plurality of back-pressure communication paths 79 are formed circumferentially around the communication chamber 78 of the control valve seat 76. These back-pressure communication paths 79 are holes extending in the second radial direction and connect the communication chamber 78 with the back-pressure chamber 68P.

[0107] The control valve seat 76 configured as described above, together with the control valve 70 , constitutes a valve 700 that is provided in a discharge flow path described later and that makes the area of ​​the discharge flow path variable.

[0108] ((Throttling component 83))

[0109] The throttle member 83 is embedded in the control valve seat 76, closer to the first side than the communication chamber 78. It includes a cylindrical portion 831 and a blocking portion 832 that blocks the opening on the second side of the cylindrical portion 831. A backpressure orifice flow path 84 is formed in the blocking portion 832, connecting the inflow flow path 81 (described later) with the communication chamber 78. The backpressure orifice flow path 84 is formed to have a smaller oil flow path cross-sectional area than the backpressure communication passage 79 and the backpressure flow path 77. Furthermore, the backpressure orifice flow path 84 prevents the oil in the backpressure chamber 68P from returning to the inflow flow path 81.

[0110] (Liaison Department 80)

[0111] like Figure 3 As shown, the communication portion 80 of the first embodiment includes an inflow flow path 81 into which oil from the communication path L flows, and a connecting portion 89 connected to the control valve seat 76 .

[0112] The inner diameter of the connecting portion 89 is substantially equal to the outer diameter of the first side of the control valve seat 76. The first end of the control valve seat 76 is inserted into the connecting portion 89. Alternatively, the communication portion 80 may be inserted into the inner side of the control valve seat 76.

[0113] (Connecting flow path portion 90)

[0114] like Figure 2 As shown, the connecting flow path portion 90 includes an inner flow path 91 provided on the second inner side and an outer flow path 92 provided on the second outer side.

[0115] The inner flow path 91 communicates with the outer cylinder opening 12H on a first side, and communicates with the inflow flow path 81 of the communication portion 80 and the main flow path 53 of the main valve seat 52 on a second side.

[0116] A plurality of outer flow paths 92 are provided in the circumferential direction. The outer flow paths 92 communicate with the case opening 13H on a first side and communicate with the case internal flow path 111 on a second side.

[0117] (Outer housing 100C)

[0118] like Figure 2 As shown, the outer housing 100C is a substantially cylindrical member and is fixed to the damper housing 13 on a first side by, for example, welding or the like.

[0119] Furthermore, the outer housing 100C forms an inner housing flow path 111 serving as a flow path for oil in the outer housing 100C on a second outer side of the main valve portion 50 and the damping force adjustment portion 60 .

[0120] The oil flowing out from the second opening 67H2 of the cover portion 67 and the oil flowing out from the main flow path 53 of the main valve seat 52 when the main valve 51 is opened flow into the in-case flow path 111 .

[0121] [Adjustment Operation of Damping Force Adjuster 60]

[0122] Next, the adjustment operation of the damping force adjustment section 60 will be described.

[0123] like Figure 4 As shown, by pressing the pressing member 63 toward the first side, the control valve 70 is pressed against the control valve seat 76. The pressing force of the pressing member 63, in other words, the thrust of the solenoid portion 62, is determined by the flow of the solenoid portion 62 (see Figure 2 ) varies with the amount of current.

[0124] For example, in the damping force adjustment unit 60, the pressing force of the pressing member 63 is maximized. At this time, the control valve 70 is most strongly pressed against the back pressure flow path 77 of the control valve seat 76, and the back pressure flow path 77 is closed (see FIG. Figure 7 ).

[0125] In addition, for example, in the damping force adjustment unit 60, the pressing force of the pressing member 63 is minimized. At this time, in the damping force adjustment unit 60, the control valve 70 is separated from the back pressure flow path 77, and the back pressure flow path 77 is opened (see Figure 5 ).

[0126] 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 minimum state and the maximum state. In this state, in the damping force adjustment unit 60, the control valve 70 is farther from the back pressure flow path 77 than in the state of maximum pressing force, and closer to the back pressure flow path 77 than in the state of minimum pressing force.

[0127] [Operation of the hydraulic shock absorber 1]

[0128] First, the operation of the hydraulic shock absorber 1 during the extension stroke will be described.

[0129] During the extension stroke, the rod 20 moves toward the other side relative to the cylinder 11. At this time, the piston valve 32 remains blocked against the piston oil passage 311. Furthermore, the movement of the piston 30 toward the other side reduces the volume of the second oil chamber Y2. Furthermore, the oil in the second oil chamber Y2 flows out of the communication hole 11H into the communication passage L.

[0130] The oil then flows into the damping force generator 100 through the connecting passage L and the outer cylindrical opening 12H. In the damping force generator 100, the oil first flows into the inner flow passage 91 of the connecting flow passage portion 90. Thereafter, a damping force is generated in the main valve 51 or the control valve 70 of the damping force generator 100. The flow of oil at this time will be described in detail later.

[0131] The oil that has flowed into the main valve 51 or the control valve 70 then flows out to the housing flow path 111. The oil then flows into the reservoir R from the housing opening 13H through the outer flow path 92 of the connecting flow path portion 90.

[0132] Furthermore, the pressure of the first oil chamber Y1 becomes relatively lower than that of the reservoir chamber R. Therefore, the oil in the reservoir chamber R flows into the first oil chamber Y1 through the bottom 40 .

[0133] Next, the operation of the hydraulic shock absorber 1 during the compression stroke will be described.

[0134] During the compression stroke, the rod 20 moves relative to the cylinder 11. In the piston portion 30, the differential pressure between the first oil chamber Y1 and the second oil chamber Y2 causes the piston valve 32, which blocks the piston oil passage 311, to open. Furthermore, the oil in the first oil chamber Y1 flows out through the piston oil passage 311 into the second oil chamber Y2. The rod 20 is located in the second oil chamber Y2. Therefore, the amount of oil flowing from the first oil chamber Y1 into the second oil chamber Y2 exceeds the volume of the rod 20. Consequently, an amount of oil equivalent to the volume of the rod 20 flows out from the connecting hole 11H into the communication path L.

[0135] The oil then flows into the damping force generator 100 through the communication passage L and the outer cylindrical opening 12H. The flow of oil in the damping force generator 100 is the same as the flow of oil during the extension stroke described above. That is, in the hydraulic shock absorber 1 of the first embodiment, the direction of oil flow in the damping force generator 100 is the same during both the compression stroke and the extension stroke.

[0136] As described above, in the hydraulic shock absorber 1 , the damping force generating device 100 generates the damping force in both the compression stroke and the extension stroke.

[0137] Next, the flow of oil in the damping force generating device 100 will be described in detail.

[0138] (Usually)

[0139] The flow of oil during a normal period when the solenoid portion 62 is in an energized state and the pressing force of the pressing member 63 is exerted will be described.

[0140] ((At low speed))

[0141] Figure 5 The piston portion 30 (see FIG. Figure 1 ) is a diagram showing an example of oil flow when the moving speed is low.

[0142] like Figure 5As shown, when the piston portion 30 moves at a low speed, the oil flowing into the inner flow path 91 flows into the inlet flow path 81 and the main flow path 53. Here, since the piston portion 30 moves at a low speed, the flow of oil that opens the main valve 51 is not generated in the main flow path 53.

[0143] On the other hand, Figure 5 As shown by the arrow, the oil flowing into the inflow flow path 81 flows through the back pressure orifice flow path 84, the communication chamber 78, the back pressure flow path 77, the second opening portion 67H2 and the cover flow path 67R in sequence. Then, the oil flows out from the housing flow path 111 to the reservoir chamber R.

[0144] As described above, when the moving speed of the piston portion 30 is low, the flow of oil is restricted by the gap between the annular portion 77R and the control valve 70 , thereby generating a damping force.

[0145] ((High speed))

[0146] Figure 6 The piston portion 30 (see FIG. Figure 1 ) is a diagram of an example of oil flow when the moving speed is high.

[0147] like Figure 6 As shown, when the piston portion 30 moves at a high speed, the oil flowing into the inner flow path 91 flows into the inlet flow path 81 and the main flow path 53. The oil flowing into the main flow path 53 opens the main valve 51 and flows into the reservoir R.

[0148] In addition, when the moving speed is high, the oil flowing into the inlet flow path 81 is also throttled by the gap between the circular portion 77R and the control valve 70 in the same way as at low speed, thereby generating a differential pressure while flowing to the flow path 111 in the shell, and then flowing out to the storage chamber R.

[0149] As described above, when the movement speed of the piston portion 30 is high, the damping force is generated mainly by the flow of oil in the main flow path 53 of the main valve seat 52 .

[0150] Furthermore, the oil flowing into the inlet flow path 81 transmits pressure to the backpressure chamber 68P via the backpressure orifice flow path 84 and the backpressure communication path 79. However, the backpressure flow path 77 communicating with the backpressure chamber 68P is in a state opened by the control valve 70. Therefore, the pressure in the backpressure chamber 68P is lower than when the control valve 70 is pressed against the backpressure flow path 77. Furthermore, the main valve 51, which is in contact with the backpressure generating mechanism 68, easily opens the main flow path 53. Therefore, when the pressing force of the pressing member 63 is minimal, the damping force generated by the flow of oil in the main flow path 53 that opens the main valve 51 is lower than when the pressing force of the pressing member 63 is maximum.

[0151] Figure 7 The piston portion 30 (see FIG. 1 ) is shown in a state where the pressing force of the pressing member 63 is maximized. Figure 1 ) is a diagram showing an example of oil flow when the moving speed is low.

[0152] ((At low speed))

[0153] like Figure 7 As shown, when the piston portion 30 moves at a low speed, the oil flowing into the inner flow path 91 flows into the inlet flow path 81 and the main flow path 53. Here, since the piston portion 30 moves at a low speed, the flow of oil flowing in the main flow path 53 by opening the main valve 51 does not occur.

[0154] On the other hand, Figure 7 As shown by the arrow, oil flowing into the inlet flow path 81 flows toward the back-pressure orifice flow path 84 and the communication chamber 78. The oil then flows through the back-pressure flow path 77 while opening the control valve 70. The oil then flows sequentially through the second opening 67H2 and the cover flow path 67R. The oil then flows out of the housing flow path 111 into the reservoir chamber R.

[0155] As described above, when the piston 30 moves at a low speed, the oil generates a damping force by flowing through the back-pressure flow path 77 while opening the control valve 70. The damping force when flowing through the back-pressure flow path 77 is higher than when the control valve 70 is separated from the back-pressure flow path 77.

[0156] ((High speed))

[0157] Figure 8 The piston portion 30 (see FIG. 1 ) is shown in a state where the pressing force of the pressing member 63 is maximized. Figure 1 ) is a diagram of an example of oil flow when the moving speed is high.

[0158] like Figure 8 As shown, when the piston portion 30 moves at a high speed, the oil flowing into the inner flow path 91 flows into the inlet flow path 81 and the main flow path 53. The oil flowing into the main flow path 53 opens the main valve 51 and flows into the reservoir R.

[0159] In addition, when the moving speed is high, the oil flowing into the inlet flow path 81 is also throttled by the gap between the circular portion 77R and the control valve 70, just like when the pressing force of the pressing component 63 is minimum, thereby generating a differential pressure while flowing to the flow path 111 in the shell, and then flowing out to the storage chamber R.

[0160] As described above, when the movement speed of the piston portion 30 is high, the damping force is generated mainly by the flow of oil in the main flow path 53 of the main valve seat 52 .

[0161] Furthermore, the oil flowing into the inlet flow path 81 transmits pressure to the backpressure chamber 68P via the backpressure orifice flow path 84 and the backpressure communication path 79. Furthermore, the backpressure flow path 77 communicating with the backpressure chamber 68P is compressed by the control valve 70. Consequently, the pressure in the backpressure chamber 68P is higher than when the backpressure flow path 77 is open. Furthermore, the main valve 51, which is in contact with the backpressure generating mechanism 68, has difficulty opening the main flow path 53. Therefore, when the pressing force of the pressing member 63 is at its maximum, the damping force generated by the flow of oil in the main flow path 53 that opens the main valve 51 is higher than when the pressing force of the pressing member 63 is at its minimum.

[0162] As described above, in the hydraulic shock absorber 1, the damping force at low speeds and the damping force at high speeds are adjusted by operating the pressing member 63. Specifically, the hydraulic shock absorber 1 adjusts the flow area of ​​the back-pressure flow path 77, which serves as the oil flow path at low speeds, and the flow area of ​​the back-pressure flow path 77, which regulates the pressure of the back-pressure chamber 68P related to the oil flow area, at high speeds by varying the pressing force of the control valve 70 against the control valve seat 76 using the pressing member 63.

[0163] Furthermore, while the above-described operational example describes two modes, namely, a state in which the pressing force of the pressing member 63 is at its minimum and a state in which it is at its maximum, the present invention is not limited to these two modes. The pressing force of the pressing member 63 can be arbitrarily set within an adjustable range based on the amount of current flowing to the solenoid portion 62, in other words, the thrust of the solenoid portion 62. Furthermore, this setting enables the damping force adjustment portion 60 to adjust the damping force at low speeds and the damping force at high speeds in multiple stages.

[0164] (Abnormal)

[0165] Next, the flow of oil during an abnormal condition, when the solenoid portion 62 is de-energized and the pressing force of the pressing member 63 is not exerted, will be described. An example of a situation in which the solenoid portion 62 is de-energized is when the current supplied to the coil of the solenoid portion 62 is stopped, for example, due to a wire break.

[0166] Figure 9 It indicates that the solenoid portion 62 is in a non-energized state and the piston portion 30 (see Figure 1 ) is a diagram showing an example of oil flow when the moving speed is low.

[0167] Figure 10 This is a diagram showing an example of the flow of oil when the solenoid portion 62 is in a non-energized state and the moving speed of the piston portion 30 is high.

[0168] like Figure 9 and Figure 10As shown, when the solenoid portion 62 is in the non-energized state, the plunger 65 is pushed back to the second side by the coil spring 64. Accordingly, the pressing member 63 fixed to the plunger 65 is pressed against the cover portion 67.

[0169] ((At low speed))

[0170] like Figure 9 As shown, when the piston portion 30 is moving at a low speed, the oil flowing into the inlet flow path 81 flows sequentially through the back-pressure orifice flow path 84, the communication chamber 78, the back-pressure flow path 77, the cap orifice flow path 67R2, the second opening 67H2, and the cap flow path 67R. The oil then flows out of the housing inlet flow path 111 into the reservoir chamber R.

[0171] Furthermore, when the movement speed of the piston portion 30 is low, a damping force is generated by the flow of oil in the cap orifice flow path 67R2 formed between the flange portion 633 of the pressing member 63 and the cap portion 67 .

[0172] ((High speed))

[0173] like Figure 10 As shown, when the piston portion 30 moves at a high speed, the oil flowing into the inner flow path 91 flows into the inlet flow path 81 and the main flow path 53. The oil flowing into the main flow path 53 opens the main valve 51 and flows into the reservoir R.

[0174] Furthermore, when the moving speed is high, the oil flowing into the inlet flow path 81 is throttled by the cap orifice flow path 67R2 in the same manner as when the speed is low, thereby flowing to the housing flow path 111 while generating a differential pressure, and then flowing out to the storage chamber R.

[0175] As described above, when the movement speed of the piston portion 30 is high, the damping force is generated mainly by the flow of oil in the main flow path 53 of the main valve seat 52 .

[0176] Here, the oil flowing into the inlet flow path 81 transmits pressure to the back pressure chamber 68P through the back pressure orifice flow path 84 and the back pressure communication path 79. The back pressure chamber 68P is connected to the housing internal flow path 111 via the back pressure flow path 77. The flow of oil between the back pressure chamber 68P and the housing internal flow path 111 needs to pass through the cover orifice flow path 67R2. In addition, by throttling the flow of oil using the cover orifice flow path 67R2, the outflow of oil from the back pressure chamber 68P is suppressed, and the pressure in the back pressure chamber 68P is maintained at a value lower than 0. Figure 6 The state shown, where the pressing force of the pressing member 63 is at its minimum, is a high state. Furthermore, the main valve 51, in contact with the back pressure generating mechanism 68, has a relatively low chance of opening the main flow path 53. Therefore, when the solenoid portion 62 is de-energized, the damping force generated by the flow of oil in the main flow path 53 of the main valve 51 is relatively high.

[0177] As described above, in the hydraulic shock absorber 1 of the first embodiment, even in an abnormal state where the solenoid portion 62 is not energized, both the damping force at low speed and the damping force at high speed are relatively high.

[0178] (About the difference between normal and abnormal times)

[0179] When the combined force of the force of the oil flowing through the back pressure flow path 77 to move the control valve 70 toward 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 toward the second side even if the thrust of the solenoid portion 62 is generated. Figure 5 、 Figure 6 When the thrust of the solenoid portion 62 is relatively small, such as in the state where the pressing force of the pressing member 63 is minimum, and the pressure of the oil passing through the back pressure flow path 77 increases, the control valve 70 temporarily moves to the second side.

[0180] In the damping force generating device 100, even if the control valve 70 moves toward the second side, the restricting member 72 inhibits the control valve 70 from moving toward the second side. In other words, the protrusion 71 contacts the restricting member 72, receiving a force from the restricting member 72 in the direction toward the first side, thereby inhibiting the control valve 70 from moving toward the second side.

[0181] Furthermore, the cylindrical portion 631 and bottom portion 632 of the pressing member 63 are positioned on the second inner side of the cylindrical portion 701 and conical portion 702 of the control valve 70. Since the outer diameter of the flange portion 633 of the pressing member 63 is smaller than the outer diameter of the cylindrical portion 701 of the control valve 70, the pressing member 63 is less susceptible to the force of oil flowing toward the second opening 67H2 through the back-pressure flow path 77. Consequently, the pressing member 63 is also restrained from moving toward the second side, and thus tends to remain stably in its normal operating position and is less likely to shift to its abnormal operating position, i.e., a state in which the pressing member 63 is pressed against the cover portion 67.

[0182] Thus, in the damping force generator 100 of this embodiment, even if the combined force of the oil force moving the control valve 70 toward the second side and the force of the coil spring 64 exceeds the thrust of the solenoid portion 62 during normal operation, the pressing member 63 is unlikely to be pressed against the cover portion 67. In other words, in the damping force generator 100, unlike during abnormal operation, the pressing member 63 is unlikely to be pressed against the cover portion 67 during normal operation. Thus, the damping force generator 100 can function normally as a mechanism while preventing abnormal operation. Furthermore, even if the mechanism experiences an abnormality, it can still function in an abnormal state. Furthermore, even if the cross-sectional area of ​​the cover orifice flow path 67R2 is changed to adjust the damping force generated during an abnormal operation, this change can be prevented from affecting the normal damping force.

[0183] 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 backpressure chamber 68P that applies pressure in the valve-closing direction to the main valve 51; and a flow path (hereinafter sometimes referred to as the "discharge flow path") that allows oil to flow out of the backpressure chamber 68P. The discharge flow path is a flow path that passes through the backpressure communication path 79, the communication chamber 78, the backpressure flow path 77, the second opening 67H2, the cover flow path 67R, and the housing internal flow path 111. Furthermore, the damping force generating device 100 includes a valve 700 disposed in the discharge flow path. This valve 700 includes a control valve 70 (an example of a valve element) that allows the area of ​​the discharge flow path to be variable, and a control valve seat 76 (an example of a valve seat) on which the control valve 70 can be seated. In addition, the damping force generating device 100 includes a pressing member 63 that can contact the side of the control valve 70 opposite to the control valve seat 76 and can apply a pressing force in the direction of pressing the control valve 70 against the control valve seat 76. In addition, the damping force generating device 100 includes a solenoid portion 62 as an example of an actuator portion, and the solenoid portion 62 can generate a thrust between a first position and a second position according to the current supplied. The first position can be exemplified as the position where the pressing member 63 is closest to the control valve seat 76, Figure 7 In addition, the second position can be exemplified as the position where the pressing member 63 is farthest from the control valve seat 76. Figure 9 Assuming that the damping force generating device 100 does not include the restricting member 72, when the pressure of the oil passing through the back pressure flow path 77 is high, even if the pressing member 63 is in the Figure 9 In the second position shown in FIG. 1 , the control valve 70 is also in a state where the end surface of the second side of the cylindrical portion 701 contacts the flange portion 633 of the pressing member 63. In this state, that is, the pressing member 63 is in the Figure 9In the case of the second position shown, the position of the control valve 70 in which the end surface of the second side of the cylindrical portion 701 contacts the flange portion 633 of the pressing member 63 is hypothetically referred to as the second position of the control valve 70. The solenoid portion 62 applies a thrust to the pressing member 63, pressing it from the second position toward the first position. In addition, the damping force generating device 100 includes a limiting member 72 that limits the movement of the control valve 70 so that even if the control valve 70 is moved in a direction that causes the pressing member 63 to move to the second position side due to the pressure of the oil passing through the exhaust flow path, the pressing member 63 will not reach the second position. That is, the damping force generating device 100 includes a housing that is formed in a cylindrical shape to accommodate the pressing member 63 and the control valve 70, and has a protrusion formed on the inner circumferential surface. In other words, the structure composed of the cover portion 67, the first spacer member 73A, and the second spacer member 73B (an example of a pair of spacers) is formed into a cylindrical shape that accommodates the pressing member 63 and the control valve 70, and the limiting member 72 protrudes toward the second inner side than the inner circumference of the first spacer member 73A and the second spacer member 73B. Furthermore, the limiting member 72 and the protrusion 71 of the control valve 70 function as an example of a limiting portion that limits the movement of the control valve 70 toward the second position to a third position between the first position and the second position. The third position can be exemplified as a position where the protrusion 71 of the control valve 70 abuts against the limiting member 72. Figure 9 Position shown.

[0184] According to the damping force generator 100, during normal operation, even if the pressure of the oil flowing through the back-pressure flow path 77 is high and the control valve 70 moves toward the second side, causing the pressing member 63 to move toward the second side, the movement of the control valve 70 is restricted by the restriction member 72, thereby preventing the pressing member 63 from reaching the position furthest from the control valve seat 76. The position furthest from the control valve seat 76 by the pressing member 63 occurs during an abnormal state, when the current supplied to the solenoid portion 62 is zero, in other words, when the solenoid portion 62 is de-energized and the thrust of the solenoid portion 62 is zero. Therefore, according to the damping force generator 100, during normal operation, when the mechanism can operate normally, even if the pressure of the oil flowing through the back-pressure flow path 77 is high, abnormal operation can be suppressed.

[0185] The damping force generating device 100 also includes 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. This force allows the pressing member 63 to move to the second position when the movement of the control valve 70 is restricted by the restricting member 72. This ensures that, in the event of an abnormality, when the thrust of the solenoid portion 62 is zero, the pressing member 63 can be reliably pressed against the cover portion 67. Therefore, even if an abnormality actually occurs in the mechanism, the abnormality-causing operation can be reliably performed.

[0186] The coil spring 64 is an example of an elastic member disposed between the control valve 70 and the pressing member 63. Therefore, the damping force adjustment unit 60 can be simplified in structure.

[0187] The pressing member 63 is fixed to the plunger 65 (an example of a driving member) of the solenoid portion 62. Therefore, in an abnormal situation, such as when the thrust of the solenoid portion 62 is zero, the pressing member 63 can be reliably pressed against the cover portion 67, and the damping force can be reliably adjusted according to the current supplied to the solenoid portion 62.

[0188] The pressing member 63 includes a cylindrical portion 631 (an example of a cylindrical portion); a bottom portion 632 that covers the opening of the cylindrical portion 631 on the control valve seat 76 side; and a flange portion 633 (an example of an applying portion) that protrudes from the outer peripheral surface of the cylindrical portion 631 toward the second outer side (an example of the outer side) and applies a pressing force to the control valve 70. Furthermore, 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 flow path 77. As a result, under normal circumstances, even if the pressure of the oil passing through the back-pressure flow path 77 is high, the movement of the pressing member 63 toward the second side can be suppressed, so that it is easy for the pressing member 63 to stably stay in the normal operating position, and abnormal operation can be suppressed.

[0189] The damping force adjustment unit 60, an example of a damping force adjustment device, includes a control valve 70 disposed in a flow path through which fluid flows, the flow path being variable in area; and a housing member that houses the control valve 70 and includes a control valve seat 76 (an example of a valve seat) formed with a back-pressure flow path 77 (an example of a through-hole) that can be closed by the control valve 70. The housing member is composed of the control valve seat 76, a cover 67, a first spacer 73A, a second spacer 73B, a third spacer 73C, and the like. The damping force adjustment unit 60 also includes a solenoid portion 62 that applies a thrust to a pressing member 63 (an example of a movable member) that is capable of contacting the side of the control valve 70 opposite the side facing the control valve seat 76; and a coil spring 64 (an example of a first spring member) having one end in contact with the control valve 70 and the other end in contact with the pressing member 63. The damping force adjustment portion 60 includes a plate-shaped urging member 75 (an example of a second spring member) having one end in contact with the control valve 70 and the other end fixed to the housing member (for example, between the first spacer member 73A and the third spacer member 73C).

[0190] According to the damping force adjustment unit 60, in the region from the state where the pressing member 63 and the control valve 70 are separated by the action of the coil spring 64 to the point where the pressing member 63 contacts the control valve 70, the force-applying member 75 is harder than the coil spring 64. Therefore, the second axial position of the control valve 70 remains unchanged, and the solenoid thrust is used only to deform the coil spring 64. In other words, the solenoid thrust is not used for other purposes, and the thrust efficiency of the solenoid unit 62 is reduced.

[0191] The pressing member 63 also includes a flange portion 633 (an example of a restricting portion) that restricts the flow path downstream of the control valve 70, i.e., the flow path that flows out to the reservoir R via the second opening 67H2, the cover flow path 67R, and the housing in-flow path 111. The other end of the coil spring 64 contacts the flange portion 633. Therefore, for example, in the event of an abnormality, the pressing member 63 can be reliably pressed against the cover portion 67.

[0192] <Second embodiment>

[0193] Figure 11 This is a diagram showing an example of a schematic configuration of a damping force generator 200 according to the second embodiment.

[0194] The damping force generator 200 of the second embodiment differs from the damping force generator 100 of the first embodiment in a control valve 270 corresponding to the control valve 70 and a restricting member 272 corresponding to the restricting member 72. The differences from the first embodiment will be described below. Identical components in the first and second embodiments are denoted by the same reference numerals, and detailed descriptions thereof will be omitted.

[0195] The restriction member 272 differs from the restriction member 72 in that it does not have the arm portion 722, but rather has only a portion corresponding to the annular portion 721. Furthermore, the inner diameter of the restriction member 272 is smaller than the inner diameters of the first and second spacer members 73A, 73B, and the restriction member 272 protrudes further inward than the first and second spacer members 73A, 73B.

[0196] Control valve 270 differs from control valve 70 in that it includes protrusion 271, which corresponds to protrusion 71. Unlike protrusion 71, protrusion 271 is not formed throughout the entire circumference. Instead, multiple protrusions 271 (e.g., four) are formed around cylindrical portion 701. Multiple protrusions 271 are arranged at equal intervals in the circumferential direction of cylindrical portion 701. The circumferential size of protrusion 271 gradually decreases as it moves from the second inner side toward the second outer side. The diameter of the imaginary circle formed by the second outer ends of the multiple protrusions 271 is larger than the inner diameter of restricting member 272 and smaller than the inner diameters of first and second spacer members 73A, 73B.

[0197] In the damping force generator 200 configured as described above, even if the control valve 270 moves toward the second side due to the pressure of the oil passing through the back pressure flow path 77 , the contact between the protrusion 271 and the restriction member 272 can suppress the control valve 270 from moving toward the second side.

[0198] As described above, the damping force generator 200 includes a valve 700 disposed in the back-pressure flow path 77. This valve 700 includes a conical portion 702 (an example of a valve element) of the control valve 270, which allows the area of ​​the back-pressure flow path 77 to be variable, and a control valve seat 76 (an example of a valve seat) on which the control valve 70 can be seated. Furthermore, the damping force generator 200 includes a protrusion 271 that restricts movement of the control valve 270. Even if the control valve 270 is moved in a direction that causes the pressing member 63 to move to the second position due to the pressure of oil flowing through the back-pressure flow path 77, the pressing member 63 does not reach the second position. Specifically, the damping force generator 200 includes a housing formed in a cylindrical shape to house the pressing member 63 and the control valve 270, with protrusions formed on the inner circumferential surface. In other words, the structure comprised of the cover 67, the first spacer 73A, and the second spacer 73B is formed into a cylindrical shape that accommodates the pressing member 63 and the control valve 270. Furthermore, the restricting member 272 protrudes further inward than the inner circumference of the first and second spacer members 73A and 73B. Furthermore, the restricting member 272 and the protrusion 271 of the control valve 270 function as an example of a restricting portion that restricts movement of the conical portion 702 of the control valve 270 toward the second position to a third position between the first and second positions. With this structure, the damping force generator 200 can suppress abnormal operation even when the oil pressure in the back-pressure flow path 77 is high, even during normal operation when the mechanism is functioning normally.

[0199] <Third embodiment>

[0200] Figure 12 This is a diagram showing an example of a schematic configuration of a damping force generating device 400 according to the third embodiment.

[0201] Figure 13 This is a diagram showing an example of a partial cross section of a damping force generating device 400 according to the third embodiment.

[0202] The damping force generator 400 of the third embodiment differs from the damping force generator 100 of the first embodiment in a damping force adjustment unit 460, which corresponds to the damping force adjustment unit 60. The differences from the first embodiment are described below. Identical components in the first and third embodiments are denoted by the same reference numerals, and detailed descriptions thereof are omitted.

[0203] The damping force adjusting unit 460 of the third embodiment differs from the damping force adjusting unit 60 of the first embodiment in a control valve seat 476 corresponding to the control valve seat 76. Furthermore, the damping force adjusting unit 460 differs from the damping force adjusting unit 60 in that the third spacer member 73C is not included, and the biasing member 75 is fixed by the first spacer member 73A and the control valve seat 476.

[0204] The control valve seat 476 has a first recessed portion 481, annularly recessed toward the first side relative to the retaining portion 471, and a second recessed portion 482, annularly recessed toward the first side, second inwardly from the first recessed portion 481, formed between the retaining portion 471, which serves as the location for securing the biasing member 75, in the second radial direction, and the annular portion 77R, on which the control valve 70 rests. A first edge portion 491 is formed at the edge of the second-side opening of the first recessed portion 481, while a second edge portion 492 is formed at the edge of the second-side opening of the second recessed portion 482. The first edge portion 491 is located slightly second inwardly from the retaining portion 471, while the second edge portion 492 forms the connection between the first and second recessed portions 481 and 482.

[0205] Figure 14 4 is a diagram showing an example of a state in which the urging member 75 is in contact with the first edge portion 491 and is not in contact with the second edge portion 492 .

[0206] Figure 15 4 is a diagram showing an example of a state in which the urging member 75 is in contact with the first edge portion 491 and the second edge portion 492 .

[0207] Figure 16 1 and 2 are diagrams showing an example of a state in which the control valve 70 is seated on the circle portion 77R.

[0208] When the current supplied to the coil of the solenoid portion 62 is the first current which is a low current, as shown in FIG. Figure 13 As shown, the control valve 70 is subjected to a force toward the second side from the biasing member 75, resulting in a state in which the elastic force of the coil spring 64 is balanced with the elastic force of the biasing member 75 and the solenoid thrust. Furthermore, while not limited to this third embodiment, the present invention, as described above, utilizes the entire solenoid thrust to deform the coil spring 64 during the period from zero to the first current supplied to the coil of the solenoid portion 62, resulting in improved thrust efficiency. In this state, the biasing member 75 does not flex, and the flat surface 707 of the control valve 70 is in surface contact with the biasing member 75.

[0209] When the current supplied to the solenoid portion 62 becomes a second current larger than the first current, as shown in FIG. Figure 14 As shown, the urging member 75 is pressed by the control valve 70 and is bent so as to come into contact with the first edge portion 491 of the control valve seat 476 .

[0210] When the current supplied to the solenoid portion 62 becomes a third current larger than the second current, as shown in FIG. Figure 15 As shown, the urging member 75 is pressed by the control valve 70 and further deflected, and comes into contact with the first edge portion 491 and the second edge portion 492 of the control valve seat 476 .

[0211] When the current supplied to the solenoid portion 62 becomes a fourth current larger than the third current, as shown in FIG. Figure 16 As shown, the urging member 75 is pressed by the control valve 70 and further flexed, and the control valve 70 is seated on the circular portion 77R.

[0212] In other words, the current supplied to the solenoid portion 62 when the biasing member 75 begins to contact the first edge portion 491 is the second current, and the current supplied to the solenoid portion 62 when the biasing member 75 begins to contact the second edge portion 492 is the third current. Furthermore, the current supplied to the solenoid portion 62 when the control valve 70 begins to seat on the circular portion 77R is the fourth current.

[0213] Figure 17 The current supplied to the solenoid portion 62 and the thrust F of the solenoid portion 62 (see Figures 14 to 16 ), the spring constant K of the urging member 75 and the valve opening amount A of the control valve 70 (refer to Figure 14 and Figure 15 ) is a diagram showing an example of their respective correlations.

[0214] When the current supplied to the solenoid portion 62 is equal to or greater than the second current and less than the third current, the urging member 75 bends with the first edge portion 491 as the starting point. When the current supplied to the solenoid portion 62 is equal to or greater than the third current, the urging member 75 bends with the second edge portion 492 as the starting point. Figure 17As shown, the spring constant K2 of the biasing member 75 when it is bent about the second edge 492 is substantially greater than the spring constant K1 when it is bent about the first edge 491. Thus, the biasing member 75 changes so that the spring constant K substantially increases as the control valve 70 moves toward the annular portion 77R (an example of a valve seat). Furthermore, when the supply current to the solenoid portion 62 is greater than the third current and less than the fourth current, the change in the valve opening amount A with respect to an increase in the supply current (in other words, an increase in the thrust F of the solenoid portion 62) is smaller than when the supply current to the solenoid portion 62 is greater than the second current and less than the third current. Therefore, when the supply current to the solenoid portion 62 is greater than the third current and less than the fourth current, the sensitivity of the actual control valve 70 position (in other words, the valve opening amount) to the supply current can be reduced compared to when the supply current is greater than the second current and less than the third current. Even when the biasing member 75 is formed of a member other than a leaf spring as described above, by utilizing, for example, an unequal pitch coil spring, the spring constant K can be changed in a substantially larger manner as the control valve 70 moves toward the annular portion 77R (an example of a valve seat).

[0215] As described above, in the damping force adjustment unit 460 of the third embodiment, the control valve seat 476 includes a first recessed portion 481, which is annularly recessed toward the circle 77R, and a second recessed portion 482, which is annularly recessed toward the circle 77R, further inward than the fixing portion 471 of the biasing member 75. Furthermore, when the amount of movement of the control valve 70 toward the circle 77R is less than a first predetermined value, the biasing member 75 does not contact the first edge 491, which is the edge of the first recessed portion 481, or the second edge 492, which is the edge of the second recessed portion 482. The amount of movement of the control valve 70 toward the circle 77R is based on the position where the movement of the control valve 70 toward the second side is restricted by the restriction member 72. The first predetermined value is the distance from the reference to the position where the current supplied to the solenoid portion 62 is the first current, the biasing member 75 is barely bent, and the elastic force of the coil spring 64 and the elastic force of the biasing member 75 are balanced. Furthermore, when the amount of movement of the control valve 70 to 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 portion 491 and not the second edge portion 492. In other words, when the current supplied to the solenoid portion 62 is greater than the second current and less than the third current, the biasing member 75 contacts the first edge portion 491 and not the second edge portion 492. Furthermore, when the amount of movement of the control valve 70 to the first side is greater than the second predetermined value, the biasing member 75 contacts both the first edge portion 491 and the second edge portion 492. In other words, when the current supplied to the solenoid portion 62 is greater than the third current, the biasing member 75 contacts both the first edge portion 491 and the second edge portion 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 portion 62 is the third current and the urging member 75 begins to contact the second edge portion 492. With the damping force adjustment unit 460 configured as described above, the spring constant K of the urging member 75 can be changed in stages, enabling fine adjustment of the damping force.

[0216] Here, if Figure 12 As shown, the biasing member 75 includes an annular portion 751, which serves as an example of a fixed portion and serves as a fixed end, and a plurality of arms 752, which serve as examples of an action portion and extend from the annular portion 751 toward the control valve 70 and simultaneously contact the control valve 70. Thus, even when the biasing member 75 applies a force to the control valve 70, a flow path from the back pressure flow path 77 to the second opening 67H2 can be formed between adjacent arms 752.

[0217] Furthermore, in the damping force adjustment unit 460 of the third embodiment, the first recess 481 and the second recess 482 are formed in the control valve seat 476, but the present invention is not particularly limited to this embodiment. Similarly to the damping force adjustment unit 60 of the first embodiment, a third spacer member 73C may be provided between the control valve seat 476 and the biasing member 75 to form the first recess 481 that is recessed toward the first side from the contact point with the biasing member 75.

[0218] In addition, the second axial position of the first edge portion 491, which serves as the starting point for the bending of the force-applying member 75, is the same throughout the entire circumference, but this is not particularly limited to the embodiment. The first recess 481 may be formed so that the second axial position of the first edge portion 491 changes in stages or continuously in the circumferential direction. Similarly, the first recess 481 may be formed so that the second radial position of the first edge portion 491 changes in stages or continuously in the circumferential direction. In this way, the spring constant K1 of the force-applying member 75 when it bends with the first edge portion 491 as the starting point can be changed in stages or continuously. In other words, the size of the depression in the second axial direction and the position in the second radial direction of the first recess 481 may not be uniform.

[0219] Similarly, the second axial position of the second edge portion 492, which serves as the starting point for the bending of the force-applying member 75, is the same throughout the entire circumference, but this is not particularly limited to this configuration. The second recess 482 may be formed so that the second axial position of the second edge portion 492 changes in stages or continuously in the circumferential direction. Similarly, the second recess 482 may be formed so that the second radial position of the second edge portion 492 changes in stages or continuously in the circumferential direction. This allows the spring constant K2 of the force-applying member 75, when bent about the second edge portion 492, to change in stages or continuously. In other words, the size of the depression in the second axial direction and the position in the second radial direction of the second recess 482 may not be uniform.

[0220] Label Description

[0221] 1: Hydraulic shock absorber, 10: Cylinder, 11: Cylinder, 20: Rod, 30: Piston, 51: Main valve (an example of a main valve), 60, 460: Damping force adjustment unit, 62: Solenoid (an example of an actuator), 63: Pressing member (an example of a movable member), 64: Coil spring (an example of a moving member, an example of a first spring member), 65: Plunger, 67: Cover (an example of a housing member), 68P: Back pressure chamber, 70: Control valve (an example of a valve element), 72: Limiting member (an example of a limiting unit), 75: Biasing member (an example of a second spring member), 76, 476: Control valve seat (an example of a valve seat) , an example of a shell part), 77: back pressure flow path (an example of a flow path), 77R: circular portion (an example of a valve seat), 100, 200, 400: damping force generating device, 270: control valve, 271: protrusion (an example of a restricting portion), 471: fixing portion, 481: first recessed portion, 482: first recessed portion, 491: first edge portion, 492: second edge portion, 631: cylindrical portion, 632: bottom portion, 633: flange portion (an example of a restricting portion), 700: valve, 702: conical portion (an example of a valve core), 751: annular portion (an example of a fixing portion), 752: arm portion (an example of an action portion).

Claims

1. A damping force adjustment device comprising: a valve core disposed on a flow path for fluid flow, so that the area of ​​the flow path can be varied; a housing member that accommodates the valve element and has a valve seat formed with a through hole that can be closed by the valve element; an actuator portion that applies thrust to a movable member capable of contacting a side of the valve element opposite to a side facing the valve seat; a first spring member having one end in contact with the valve core and the other end in contact with the movable member; as well as The second spring member has one end in contact with the valve element and the other end fixed to the housing member.

2. The damping force adjustment device according to claim 1, wherein: The movable member has a restriction portion that restricts the flow path downstream of the valve element. The other end of the first spring member is in contact with the restriction portion.

3. The damping force adjustment device according to claim 1, wherein: A spring constant of the second spring member changes as the valve element moves toward the valve seat.

4. The damping force adjustment device according to claim 3, wherein: The second spring member is formed of a leaf spring. As the valve element moves toward the valve seat, a contact position between the second spring member and the housing member changes, thereby increasing the spring constant of the second spring member.

5. The damping force adjustment device according to claim 1, wherein: A first recess and a second recess are formed on the housing member. The first recess is annularly recessed on the inner side of the fixing portion of the second spring member toward the valve seat, and the second recess is annularly recessed on the inner side of the first recess toward the valve seat. When the amount of movement of the valve element toward the valve seat is less than or equal to a first prescribed value, the second spring member does not contact the first edge portion serving as the edge of the first recess and the second edge portion serving as the edge of the second recess. When the amount of movement is greater than the first prescribed value and less than a second prescribed value, the second spring member contacts the first edge portion but not the second edge portion. When the amount of movement is greater than or equal to the second prescribed value, the second spring member contacts both the first edge portion and the second edge portion.

6. The damping force adjustment device according to claim 5, wherein: The second spring member includes a fixed portion serving as a fixed end and one or more acting portions extending from the fixed portion toward the valve element and contacting the valve element.

7. The damping force adjustment device according to claim 6, wherein: The acting portion of the second spring member is in contact with the first edge portion and the second edge portion.

8. A buffer device comprising: a piston portion inserted into a cylinder in which a fluid is sealed and movable relative to the cylinder; and The damping force adjustment device according to any one of claims 1 to 7 adjusts the damping force generated by the flow of the fluid generated by the movement of the piston portion.

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