Damping force adjusting valve and damping force adjusting type shock absorber

Abstract

A damping force generating device (50) is provided with: a structural member in which a through hole penetrating in the axial direction is formed; a first valve body which is provided so as to face one opening of the through hole in the axial direction, and which is capable of adjusting the distance from the one opening by means of an actuator; a back pressure chamber in which the internal pressure is adjusted in accordance with the axial position of the first valve body; a second valve body that receives pressure in the valve closing direction by the internal pressure, has a communication hole that communicates with the back pressure chamber at a position offset from the central axis of the other opening of the through hole, and is guided by a guide member to move in the axial direction; and a valve seat on which the second valve body can be seated.

Description

Technical Field

[0001] This invention relates to a damping force adjusting valve and a damping force adjusting buffer. Background Technology

[0002] For example, the device described in Patent Document 1 includes a valve component, a valve seat, and a pilot valve that are axially movable relative to the housing. The pilot valve has a pilot valve seat and a pilot valve core.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: EP3988816 Summary of the Invention

[0006] The problem that the invention aims to solve

[0007] As described in Patent Document 1, when the throttle orifice formed in the first valve core (a valve component in Patent Document 1) for introducing oil to the pilot valve is aligned with the axial position of the pilot passage opened and closed by the second valve core (a pilot valve core in Patent Document 1), the second valve core may be accidentally opened due to oil passing through the throttle orifice.

[0008] The object of the present invention is to provide a damping force adjusting valve, etc., that can prevent the second valve core from opening accidentally due to oil passing through the throttling orifice formed in the first valve core.

[0009] Methods for solving problems

[0010] The present invention, made for this purpose, is a damping force adjusting valve comprising: a structural component having a through hole extending axially; a first valve core axially opposed to an opening of the through hole and adjustable by an actuator in the distance between the valve core and the opening; a back pressure chamber adjusting internal pressure according to the axial position of the first valve core; a second valve core subjected to pressure in a closing direction by the internal pressure and having a communication hole communicating with the back pressure chamber at a position offset from the central axis of another opening of the through hole, the second valve core being guided by a guide component to move axially; and a valve seat for the second valve core to be seated.

[0011] Invention Effects

[0012] According to the present invention, it is possible to prevent the second valve core from opening accidentally due to oil passing through the throttling orifice formed in the first valve core. Attached Figure Description

[0013] Figure 1 This is a diagram illustrating an example of the schematic structure of the suspension device 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 This is a diagram showing an example of a three-dimensional cross-section of a portion of the main valve section and the damping force adjustment section in the first embodiment.

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

[0017] Figure 5 This is a diagram showing an example of a part of a sealing component.

[0018] Figure 6 This diagram illustrates an example of oil flow when the piston moves at a low speed and the pressing force of the pressing component is minimized.

[0019] Figure 7 This diagram illustrates an example of oil flow under conditions where the pressing force of the pressing component is minimized and the piston moves at a high speed.

[0020] Figure 8 This diagram illustrates an example of oil flow when the piston moves at a low speed while the pressing force of the pressing component is at its maximum.

[0021] Figure 9 This diagram illustrates an example of oil flow when the piston moves at high speed, maximizing the pressing force of the pressing component.

[0022] Figure 10 This diagram illustrates an example of oil flow when the solenoid is not energized and the piston moves at a low speed.

[0023] Figure 11 This diagram illustrates an example of oil flow when the solenoid is not energized and the piston moves at a high speed.

[0024] Figure 12 This is an enlarged view showing an example of the structure of the main valve, guide components, and sealing mechanism. Detailed Implementation

[0025] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0026] <First Implementation Method>

[0027] Figure 1 This is a diagram showing an example of the schematic structure of the suspension device 1 according to the first embodiment.

[0028] Suspension device 1 is a suspension used in four-wheeled vehicles such as passenger cars, such as... Figure 1 As shown, the suspension system includes a hydraulically operated buffer device 2 and a coil spring 3 disposed on the outside of the buffer device 2. Additionally, the suspension device 1 includes a lower spring seat 4, which supports the coil spring 3 on one side of the axial direction of the rear rod 20 (in...). Figure 1 The lower end (in the middle); and the upper spring seat 5, which supports the rod 20 of the coil spring 3 on the other side axially (in the middle). Figure 1 The end of the middle (the upper side).

[0029] Additionally, the suspension device 1 includes: a vehicle side bracket 6 for mounting the suspension device 1 to the vehicle; a wheel side bracket 7 for mounting the suspension device 1 to the wheel; and a dust cover 8 that covers at least a portion of the cylinder portion 10 and the rod 20.

[0030] Hereinafter, the axial direction of rod 20 will sometimes be simply referred to as "axial direction". Additionally, sometimes one side of the axial direction (in...) Figure 1 The middle is the lower side), the other side of the axis (in Figure 1 The center (or top) side is referred to as "one side" and "the other side" respectively. In addition, the direction that intersects the axis (e.g., the vertical direction) is called the "radial direction". In the radial direction, the side of the cylinder 11 with the center line is sometimes referred to as the "inner side" and the side away from the center line is referred to as the "outer side".

[0031] The buffer device 2 includes: a cylinder 10 that holds oil; and a rod 20, one side of which protrudes from the cylinder 10 and the other side is slidably inserted into the cylinder 10. Furthermore, the buffer device 2 includes a piston portion 30 located at one end of the rod 20 and a bottom portion 40 located at one end of the cylinder 10. Moreover, the buffer device 2 includes a damping force generating device 50 located outside the cylinder 10 and generating damping force.

[0032] The cylinder section 10 has an oil-receiving cylinder 11, an outer cylinder 12 disposed outside the cylinder 11, and a damper housing 13 disposed outside the cylinder 11 and further outside the outer cylinder 12. In addition, the cylinder section 10 has a rod guide 14 that supports the rod 20 so that it can move, a limiting cover 15, and an oil seal 16 that prevents foreign matter from entering the cylinder section 10.

[0033] The cylinder 11 is formed in a cylindrical shape, and a connecting hole 11H is formed at the other end to connect the interior and the exterior.

[0034] The outer cylinder 12 is cylindrical. Furthermore, a connecting passage L is formed between the outer cylinder 12 and the cylinder 11. Additionally, the outer cylinder 12 has an outer cylinder opening 12H and an outer connecting portion 12J at a position opposite to the damping force generating device 50. The outer connecting portion 12J has an oil flow path and protrudes outward to form a connection point with the damping force generating device 50.

[0035] The damper housing 13 is cylindrical. Furthermore, an oil storage chamber R is formed between the damper housing 13 and the outer cylinder 12. The storage chamber R absorbs oil from the cylinder 11 or supplies oil to the cylinder 11 as the rod 20 moves relative to the cylinder 11. Additionally, the storage chamber R stores oil flowing out of the damping force generating device 50. Furthermore, the damper housing 13 has a housing opening 13H at a position opposite the damping force generating device 50.

[0036] Rod 20 is a rod-shaped component that extends axially. Rod 20 holds piston portion 30 on one side. Additionally, rod 20 is connected to vehicle body, for example, via a connecting component (not shown) on the other side.

[0037] The piston section 30 includes: a piston body 31 having a plurality of piston oil ports 311; a piston valve 32 for opening and closing the other side of the piston oil ports 311; and a spring 33 disposed between the piston valve 32 and one end of the rod 20. Furthermore, the piston section 30 divides the oil in the cylinder 11 into a first oil chamber Y1 and a second oil chamber Y2.

[0038] The bottom 40 has a valve seat 41, a check valve portion 43 disposed on the other side of the valve seat 41, and a fixing member 44 disposed along the axial direction. Furthermore, the bottom 40 is divided into a first oil chamber Y1 and a storage chamber R.

[0039] [Structure and function of damping force generating device 50]

[0040] Figure 2 This is a diagram showing an example of a cross-section of the damping force generating device 50 of the first embodiment.

[0041] Figure 3 This is a diagram showing an example of a three-dimensional cross-section of a portion of the main valve section 51 and the damping force adjustment section 60 in the first embodiment.

[0042] Figure 4 This is a diagram showing an example of a partial cross-section of a portion of the main valve section 51 and the damping force adjustment section 60 in the first embodiment.

[0043] Figure 5 This is a diagram showing an example of a portion of the sealing component 55.

[0044] In the following explanation, sometimes... Figure 2The damping force generating device 50 shown is oriented along its long side (i.e., along the axial direction of the cylinder 10, as referenced). Figure 1 The direction of intersection (e.g., approximately perpendicular) of the intersection is referred to as the "second axis". Additionally, the central axis side of the cylinder 10 (in...) is sometimes referred to as the second axis. Figure 2 The lower side of the damping force generating device 50 is referred to as the "first side," and the side furthest from the central axis of the cylinder 10 (in...) Figure 2 The upper side of the damping force generating device 50 is referred to as the "second side".

[0045] In addition, sometimes Figure 2 The direction of the short side of the damping force generating device 50 shown (i.e., the direction intersecting the second axis) is called the "second radial direction". Furthermore, in the second radial direction, the side along the central axis of the second axis is sometimes called the "second inner side", and the side away from the central axis along the second axis is called the "second outer side".

[0046] like Figure 2 As shown, the damping force generating device 50 includes: a main valve section 51, which is mainly located in the buffer device 2 (see reference). Figure 1 The device generates damping force in the main valve section 51; and a damping force adjustment section 60, which adjusts the magnitude of the damping force generated by the damping force generating device 50. Furthermore, the damping force generating device 50 includes a connecting flow path section 90 that forms a flow path for oil from the connecting path L relative to the main valve section 51.

[0047] (Main valve section 51)

[0048] The main valve section 51 includes: a main valve 52, which generates a damping force by controlling the flow of oil in a throttling manner; and a main valve seat 53, which is opposite to and in contact with the main valve 52. Additionally, the main valve section 51 includes: an elastic member 54, which applies a force to press the main valve 52 against the main valve seat 53 by elastic deformation; and a sealing member 55, which seals the main valve 52 between itself and the guide member 61 described later.

[0049] (Main valve 52)

[0050] The main valve 52 has a cylindrical portion 521 and a bottom portion 522 that covers the first side of the cylindrical portion 521.

[0051] The inner diameter of the cylindrical part 521 is larger than the inner diameter of the main valve seat 53, and the outer diameter is smaller than the diameter of the inner circumferential surface of the guide member 61 described later.

[0052] At the end of the first side of the cylindrical portion 521, there is a portion protruding from the end face of the first side to the first side, namely an inner protrusion 523 provided on the second inner side and an outer protrusion 524 provided at a position on the second outer side of the inner protrusion 523. The inner protrusion 523 and the outer protrusion 524 are each formed in an annular shape.

[0053] A groove 525, recessed from the outer periphery to the second inner side, is formed all around the cylindrical portion 521. The cross-sectional shape of the groove 525, cut by a plane passing through the center line of the cylindrical portion 521, is rectangular. A sealing member 55 is embedded in the groove 525.

[0054] The diameter of the outer peripheral surface of the cylindrical portion 521 is formed to decrease progressively or non-progressively as it moves away from the groove 525 along the second axial direction. Therefore, the gap between the cylindrical portion 521 and the inner peripheral surface of the guide member 61 is smallest on both sides of the groove 525 and increases progressively or non-progressively as it moves away from the groove 525 along the second axial direction.

[0055] At the bottom 522, an inlet hole 526 is formed around the center line of the cylindrical portion 521. Figure 3 In the example shown, two inlet holes 526 are formed. Additionally, as... Figure 3 As shown, conical recesses can also be formed on both sides of the second axial direction of the inlet hole 526.

[0056] When viewed along the second axial direction, the inlet hole 526 is formed so as not to overlap with the through hole 69 of the guide member 61, which will be described later.

[0057] (Main valve seat 53)

[0058] The main valve seat 53 is a cylindrical component, and has a flange 531 at the end on the first side that protrudes cylindrically from the outer circumference all the way to the second outer side.

[0059] The flange portion 531 is a cylindrical protruding part that holds the guide member 61, etc., between it and the cover portion 80, which will be described later.

[0060] Furthermore, the main valve seat 53 has a portion protruding from the end face of the second side at its second side end, namely an inner valve seat portion 533 disposed on the second inner side and an outer valve seat portion 534 disposed at a position further outward than the inner valve seat portion 533. The inner valve seat portion 533 and the outer valve seat portion 534 are each formed in an annular shape. The inner valve seat portion 533 is disposed at a position corresponding to the inner protrusion 523 of the main valve 52, and the outer valve seat portion 534 is disposed at a position corresponding to the outer protrusion 524 of the main valve 52.

[0061] (Elastic component 54)

[0062] like Figure 3 As shown, the elastic member 54 is plate-shaped and has an annular portion 541 formed in a ring shape and a plurality of arm portions 542 protruding from the annular portion 541 toward the second inner side.

[0063] The annular portion 541 is set to be approximately the same size as the end face of the second side of the cylindrical portion 521 of the main valve 52.

[0064] The arm portion 542 is formed such that its circumferential size gradually decreases as it moves toward the second inner side. The diameter of the imaginary circle formed by connecting the ends of the plurality of arm portions 542 is larger than the outer diameter of the first protrusion 662 of the guide member 61 (described later) and smaller than the outer diameter of the first surface 661.

[0065] The elastic member 54 is formed of metal or the like, and the ends of the plurality of arms 542 are supported by the first surface 661. Corresponding to the movement of the main valve 52 to the second side, the annular portion 541 elastically deforms in a way that moves to the second side, and applies a force in the direction that causes the main valve 52 to return to the main valve seat 53.

[0066] The multiple arms 542 are preferably configured such that, when viewed along the second axial direction, the elastic member 54 has a point-symmetric or line-symmetric shape. For example, as Figure 3 As shown, by forming an even number (e.g., six) of arms 542 at equal intervals in the circumferential direction, the elastic member 54 becomes a point-symmetric and line-symmetric shape. By making the elastic member 54 a point-symmetric or line-symmetric shape, it is easy to apply force evenly to the main valve 52.

[0067] ((Sealing component 55))

[0068] The sealing member 55 is an annular member with a rectangular cross-section when cut with a plane parallel to the second axis. The rectangle is a rectangle with the second axis as the long side and the second radius as the short side. However, the sealing member 55 has a seam 550 formed in a portion of its circumferential direction. Furthermore, the cross-sectional shape is not limited as long as it fulfills the function of the sealing member 55.

[0069] Figure 5 This diagram shows the state in which the joint 550 is separated in order to clarify the structure of the joint 550.

[0070] The seam 550 has a cuboid protrusion 551 at one end in the circumferential direction, which protrudes to the other end, and a receiving portion 552 is formed at the other end for the protrusion 551 to sit on. Furthermore, the sealing member 55 is embedded in the groove 525 in such a state that the protrusion 551 is seated on the receiving portion 552.

[0071] The main valve 52 and main valve seat 53, configured as described above, constitute the first valve mechanism V1. This first valve mechanism V1 controls the flow of oil from the connecting passage L through the transverse hole 64 of the guide member 61 to the storage chamber R (see reference). Figure 7 The main valve 52 is opened and closed by contacting the inner protrusion 523 and the outer protrusion 524 of the main valve 52 with the inner valve seat portion 533 and the outer valve seat portion 534 of the main valve seat 53, respectively. The main valve 52 also opens the first flow path R1 by moving away from the inner valve seat portion 533 and the outer valve seat portion 534. Furthermore, the first valve generates a damping force by throttling the flow of oil in the first flow path R1.

[0072] (Damping force adjustment unit 60)

[0073] like Figure 2 As shown, the damping force adjustment unit 60 includes: a guide member 61 that guides the second axial movement of the main valve 52; and a control valve 70 that moves relative to the guide member 61 to form a second flow path R2 (see reference 1) parallel to the first flow path R1. Figure 6 The damping force adjustment unit 60 includes: a pressing member 77 that presses the control valve 70 against the guide member 61; a coil spring 79 disposed between the control valve 70 and the pressing member 77; and a solenoid 100 that moves the pressing member 77 forward and backward toward the guide member 61. The damping force adjustment unit 60 also includes: a limiting member 72 that limits the movement of the control valve 70 to a second side; and a force applying member 75 that applies a force to the control valve 70 in the opposite direction to the thrust of the solenoid 102 described later. Furthermore, the damping force adjustment unit 60 includes a first spacer 73A between the force applying member 75 and the limiting member 72, a second spacer 73B between the limiting member 72 and the cover 80 described later, and a third spacer 73C between the guide member 61 and the force applying member 75. In addition, the damping force adjustment part 60 has a cover 80 that covers the area around the control valve 70, the limiting member 72, the first spacing member 73A, the second spacing member 73B and the third spacing member 73C.

[0074] (Guiding component 61)

[0075] The guide member 61 has a cylindrical portion 62 and a top 65 that covers the second side of the opening of the cylindrical portion 62.

[0076] The inner diameter of the cylindrical portion 62 is larger than the outer diameter of the cylindrical portion 521 of the main valve 52, and smaller than the outer diameter of the flange portion 531 of the main valve seat 53. Furthermore, the main valve 52 is disposed on the second inner side of the cylindrical portion 62. The outer diameter of the cylindrical portion 62 is smaller than the inner diameter of the first cylindrical portion 81 of the cover portion 80, which will be described later.

[0077] At the end of the first side of the cylindrical portion 62, a stepped portion 63 is formed on the inner periphery, which is recessed from the end face of the first side to the second side. The cross-sectional shape of the stepped portion 63 cut by the surface passing through the center line of the cylindrical portion 62 is rectangular, and the flange portion 531 of the main valve seat 53 can be fitted into the stepped portion 63.

[0078] A transverse hole 64 in the second radial direction is formed on the second side of the cylindrical portion 62, which is closer to the stepped portion 63. The transverse hole 64 is, for example, cylindrical, and multiple holes are formed in the circumferential direction.

[0079] Alternatively, a gap can be formed when the stepped portion 63 is engaged with the flange portion 531 of the main valve seat 53, and this gap can be connected to the return hole 93 described later, thereby omitting the transverse hole 64.

[0080] The top 65 has a central portion 66 as an inner peripheral side (second inner side), an outer peripheral portion 67 as an outer peripheral side (second outer side), and an intermediate portion 68 between the central portion 66 and the outer peripheral portion 67. The central portion 66 protrudes towards the main valve 52 side more than the outer peripheral portion 67, and the intermediate portion 68 is inclined in a straight or curved manner relative to the second radial direction.

[0081] A second axial through hole 69 is formed in the central portion 66. The through hole 69 is composed of a first hole 691 formed on the first side and a second hole 692 formed on the second side. The through hole 69 forms part of a second flow path R2 that branches off from the first flow path R1.

[0082] The central portion 66 has a first protrusion 662 around the opening on the first side of the first hole 691, which protrudes cylindrically toward the first side from the first surface 661, which is the end face of the first side. The first surface 661 restricts the movement of the elastic member 54 toward the second side. The first protrusion 662 is inserted into the second inner side of the elastic member 54, and the outer peripheral surface of the first protrusion 662 restricts the movement of the elastic member 54 in the second radial direction.

[0083] Furthermore, the central portion 66 has a second protrusion 663 that protrudes conically from the second inner side of the middle portion 68 around the opening on the second side of the second hole 692. The control valve 70 can contact and separate from the second protrusion 663. Therefore, the second flow path R2 is closed by the control valve 70 contacting the second protrusion 663, and the second flow path R2 is opened by the control valve 70 leaving the second protrusion 663. That is, the control valve 70 and the second protrusion 663 constitute the second valve mechanism V2 for opening and closing the second flow path R2.

[0084] The central portion 66 protrudes towards the main valve 52 from the outer peripheral portion 67, and the middle portion 68 is inclined relative to the second radial direction, thereby forming a recess 664 around the second hole 692, which is recessed from the second side of the outer peripheral portion 67 towards the first side. Even when the control valve 70 is moved to the first side to the maximum extent and contacts the second protrusion 663, the recess 664 can deform the force-applying member 75 and can accommodate the first side portion of the control valve 70.

[0085] (Control valve 70)

[0086] The control valve 70 has a cylindrical portion 701 and a conical portion 702, the conical portion 702 covering the opening on a first side of the cylindrical portion 701 and protruding towards the first side. Furthermore, the control valve 70 has a protrusion 703 at the end of the cylindrical portion 701 on the first side, protruding circumferentially outward. Additionally, the control valve 70 has a flat surface 704 perpendicular to the second axis at the end and second inner side of the conical portion 702. Furthermore, the control valve 70 has a convex portion 706 protruding outward at the center of the conical portion 702 along the second axis. A flat surface 707 perpendicular to the second axis is formed on the convex portion 706.

[0087] The outer diameter of the cylindrical portion 701 is larger than or equal to the outer diameter of the flange portion 773 of the pressing member 77, while the inner diameter of the cylindrical portion 701 is smaller than the outer diameter of the flange portion 773. As a result, the end face of the second side of the cylindrical portion 701 contacts the flange portion 773 of the pressing member 77.

[0088] Furthermore, the inner diameter of the cylindrical portion 701 is larger than the outer diameter of the cylindrical portion 771 of the pressing member 77. Therefore, with the second end face of the cylindrical portion 701 in contact with the flange 773 of the pressing member 77, the cylindrical portion 771 and bottom 772 of the pressing member 77 are housed within the second inner side of the control valve 70. A coil spring 79 is disposed within the space 705 formed between the cylindrical portion 701 of the control valve 70 and the cylindrical portion 771 of the pressing member 77. The first end of the coil spring 79 is supported on the flat surface 704 of the control valve 70, and the second end of the coil spring 79 is supported on the flange 773 of the pressing member 77. Thus, the coil spring 79 is a component that functions at both ends; since it does not have a fixed end, a portion of the thrust of the solenoid portion 102 does not act on the component located on the fixed side before the fixed end via the fixed end. Therefore, the thrust applied to the solenoid portion 102 of the helical spring 79 is entirely used to deform the helical spring 79 itself, thus increasing the thrust efficiency.

[0089] ((Restricted component 72))

[0090] like Figure 3 As shown, the limiting member 72 has an annular portion 721 formed in a ring shape and a plurality of arm portions 722 protruding from the annular portion 721 toward a second inner side. The diameter of the imaginary circle formed by the ends of the plurality of arm portions 722 on the second inner side is larger than the diameter of the outer peripheral surface of the cylindrical portion 701 of the control valve 70, and smaller than the diameter of the outer peripheral surface of the protrusion 703.

[0091] ((First spacer 73A, second spacer 73B and third spacer 73C))

[0092] The first spacer 73A, the second spacer 73B, and the third spacer 73C are annular components. The outer diameter of the first spacer 73A, the second spacer 73B, and the third spacer 73C is larger than the inner diameter of the second cylindrical portion 82 of the cover 80 (described later) and smaller than the inner diameter of the first cylindrical portion 81 (described later). Furthermore, the inner diameter of the first spacer 73A, the second spacer 73B, and the third spacer 73C is larger than the inner diameter of the second cylindrical portion 82 of the cover 80 and smaller than the inner diameter of the first cylindrical portion 81.

[0093] The first spacer 73A and the second spacer 73B are disposed between the end face of the second cylindrical portion 82 of the cover portion 80 on the first side and the force-applying member 75, defining the second axial position of the limiting member 72. More specifically, the limiting member 72 is located on the second side closer to the protrusion 703 of the control valve 70, limiting the movement of the control valve 70 to the second side.

[0094] Furthermore, by adjusting the size (hereinafter, sometimes referred to as "thickness") of the second axial direction of the first spacer 73A and the second spacer 73B, the position of the second axial direction of the limiting member 72 can be adjusted. For example, when it is desired to set the position of the second axial direction of the limiting member 72 to a position greater than that of the first spacer 73A and the second spacer 73B, the position of the limiting member 72 can be adjusted. Figure 4 When positioned on the first side, the thickness of the first spacer 73A can be made greater than that of the first spacer. Figure 4 The thickness shown is thin, making the thickness of the second spacer 73B greater than that of the second spacer. Figure 4 The thickness shown is thick. On the other hand, the position of the second axial direction of the limiting member 72 is set to be thicker than that of the limiting member 72. Figure 4 When positioned on the second side, the thickness of the first spacer 73A can be made greater than that of the second spacer. Figure 4 The thickness shown is thicker, making the thickness of the second spacer 73B greater than that of the second spacer 73B. Figure 4 The thickness shown is thin.

[0095] The third spacer 73C is disposed between the force-applying member 75 and the guide member 61, defining the position of the force-applying member 75 along its second axis. Furthermore, by adjusting the size (hereinafter, sometimes referred to as "thickness") of the second axis of the third spacer 73C, the position of the force-applying member 75 along its second axis can be adjusted. For example, when it is desired to set the position of the force-applying member 75 at a position greater than... Figure 4 When positioned near the first side, the thickness of the third spacer 73C can be made greater than that of the first spacer. Figure 4 The thickness shown is thin, making the thickness of the first spacer 73A greater than that of the first spacer. Figure 4 The thickness shown is thick. On the other hand, the position of the second axial direction of the force-applying component 75 is set to be thicker than that of the other component. Figure 4 When positioned on the second side, the thickness of the third spacer 73C can be made greater than that of the second spacer. Figure 4 The thickness shown is thicker, making the thickness of the first spacer 73A greater than that of the first spacer 73A. Figure 4 The thickness shown is thin.

[0096] (Force-applying component 75)

[0097] The force-applying component 75 is a ring-shaped leaf spring that applies a force to the control valve 70 in the opposite direction to the thrust of the solenoid portion 102 and the elastic force of the coil spring 79. It is set to a higher spring constant than the coil spring 79. The force-applying component 75 has: a ring-shaped portion 751, which functions as a fixed end; and multiple arms 752, which protrude from the ring-shaped portion 751 toward a second inner side, functioning as actuating ends. Furthermore, the shape of the force-applying component 75 is not limited to this; as long as it has a fixed end and an actuating end acting on the control valve 70, the shape is not particularly limited. For example, three arms 752 are provided at equal intervals along the circumference of the ring-shaped portion 751. However, the number of arms 752 is not limited to three; it can be two or fewer, or four or more. Additionally, the shapes of the multiple arms 752 can all be identical or different. For example, the circumferential size of each of the multiple arms 752 can also be different. In addition, the force-applying component 75 may not be a leaf spring, but an elastic component such as a helical spring located between the control valve 70 and the guide component 61.

[0098] (Pressing component 77)

[0099] like Figure 4 As shown, the pressing member 77 has: a cylindrical portion 771; a bottom 772 that covers the opening on the first side of the cylindrical portion 771; and a flange portion 773 that is disposed at the end of the second side of the cylindrical portion 771 and protrudes outwardly throughout the entire circumference.

[0100] (Helical Spring 79)

[0101] The coil spring 79 is a compression coil spring that contacts the control valve 70 on the first side and the pressing member 77 on the second side. Furthermore, the coil spring 79 applies forces to the pressing member 77 and the control valve 70 in directions that cause the pressing member 77 to separate from the control valve 70. Alternatively, other components, such as elastic rings, can be used instead of the coil spring 79 to achieve the same function.

[0102] ((Cover 80))

[0103] The cover portion 80 has three cylindrical portions with the same outer diameter and different inner diameters: a first cylindrical portion 81 disposed on a first side, a second cylindrical portion 82 disposed on a second side closer to the first cylindrical portion 81, and a third cylindrical portion 83 disposed on a second side closer to the second cylindrical portion 82. The outer diameter of the cover portion 80 is smaller than the inner diameter of the inner housing 180 described later, and it is disposed on the second inner side of the inner housing 180.

[0104] The inner diameter of the first cylindrical portion 81 is larger than the outer diameter of the guide member 61, the first spacer member 73A, the second spacer member 73B, the third spacer member 73C, the limiting member 72, and the force-applying member 75, and it is disposed on the second outer side of these members.

[0105] The inner diameter of the second cylindrical portion 82 is smaller than the outer diameter of the guide member 61, the first spacer member 73A, the second spacer member 73B, the third spacer member 73C, the limiting member 72, and the force-applying member 75. Furthermore, the guide member 61, the first spacer member 73A, the second spacer member 73B, the third spacer member 73C, the limiting member 72, and the force-applying member 75 are clamped between the end face of the first side of the second cylindrical portion 82 and the flange portion 531 of the main valve seat 53, thus fixing the second axial position of these components.

[0106] The inner diameter of the third cylindrical portion 83 is larger than the outer diameter of the plunger 117 (described later) and smaller than the outer diameter of the flange portion 773 of the pressing member 77. Thus, the first end of the plunger 117, the pressing member 77, the coil spring 79, and the control valve 70 are housed on the second inner side of the cover portion 80. A groove 831, recessed from the end face to the second side, is formed at the first end of the third cylindrical portion 83.

[0107] On the outer periphery of the cover portion 80, a groove, namely a second axial groove 84, is formed that is recessed from the outer periphery to the second inner side, covering the entire area of ​​the second axial direction. One or more second axial grooves 84 are formed in the circumferential direction. In addition, at the end of the second side of the cover portion 80, a groove, namely a second radial direction groove 85, is formed that is recessed from the end face to the first side, covering the entire area of ​​the second radial direction. The second radial direction groove 85 is formed at a position corresponding to the second axial groove 84, and discharges oil that has passed through the second inner side of the third cylindrical portion 83 to the annular gap S1 described later.

[0108] (Solenoid 100)

[0109] The solenoid 100 includes: a valve section 101 for opening and closing the second flow path R2; a solenoid section 102 for driving the plunger 117 of the valve section 101 (described later); and a housing 160 for housing the valve section 101, the coil 121 of the solenoid section 102 (described later), etc. Additionally, the solenoid 100 includes an elastic sealing member 190 for sealing the gap between the solenoid section 102 and the housing 160.

[0110] ((Valve section 101))

[0111] The valve part 101 has a fixed part 110 that is fixed and a movable part 116 that can move relative to the fixed part 110.

[0112] The fixing part 110 has a first fixing member 111 disposed on a first side, a second fixing member 112 disposed on a second side closer to the first fixing member 111, and a spacer 113 disposed between the first fixing member 111 and the second fixing member 112. The first fixing member 111 and the second fixing member 112 are formed of magnetic materials such as iron, and the spacer 113 is formed of non-magnetic materials such as resin.

[0113] The first fixing member 111 has a first protrusion 111a that protrudes in an annular shape from the outer periphery of the first end to the second outer side. Inside the first fixing member 111 is a first bearing 114 that supports the plunger 117 (described later) so that it can move in a second axial direction. The first bearing 114 is cylindrical and is fixed in a manner that prevents it from moving relative to the first fixing member 111.

[0114] The second fixing member 112 has: a cylindrical part 112a, which is disposed on the first side; and a covering part 112b, which is disposed on the second side of the cylindrical part 112a and covers the opening of the cylindrical part 112a.

[0115] A second bearing 115 is provided on the inner side of the cover portion 112b to support the plunger 117 (described later) so that it can move in the second axial direction. The second bearing 115 is cylindrical and is fixed in a manner that prevents it from moving relative to the second fixed member 112.

[0116] The movable part 116 has: a plunger 117, which is cylindrical and holds the pressing member 77; and a movable iron core 118, which is held around the plunger 117.

[0117] The plunger 117 is a rod-shaped component formed along a second axial direction. The plunger 117 holds the pressing member 77 on a first side and holds a movable iron core 118 at its axial center. The plunger 117 is supported by a first bearing 114 and a second bearing 115 in a manner that allows it to move along the second axial direction. When the solenoid section 102 is energized, the plunger 117, together with the pressing member 77, is pushed towards the first side by the solenoid section 102. Conversely, when the solenoid section 102 is de-energized, the plunger 117, together with the pressing member 77, is pushed back towards the second side by a helical spring 79.

[0118] ((Shell 160))

[0119] The housing 160 includes an outer housing 170, which is generally cylindrical in shape and disposed on the outer side, and an inner housing 180 disposed on the inner side of the outer housing 170. It is possible that the outer housing 170 and the inner housing 180 are formed of metal. Alternatively, it is possible that the outer housing 170 is formed of metal and the inner housing 180 is formed of resin.

[0120] The outer casing 170 has a first cylindrical portion 171 disposed on a first side and a second cylindrical portion 172 disposed on a second side closer to the first cylindrical portion 171. The inner diameter of the first cylindrical portion 171 is the same as the inner diameter of the second cylindrical portion 172. On the other hand, the outer diameter of the first cylindrical portion 171 is larger than the outer diameter of the second cylindrical portion 172. The end of the first cylindrical portion 171 on the second side has an inclined surface 173 that is inclined axially in a manner that gradually increases in diameter from the second side toward the first side.

[0121] The first cylindrical portion 171 has a protrusion 174 at its end on the first side that protrudes in a ring shape from the inner circumference towards the second inner side.

[0122] A groove 175 is formed in the first cylindrical portion 171, recessed around its entire circumference from the outer peripheral surface 170a toward the second inner side. The groove 175 has: a first surface 176, which is inclined relative to the second axial direction; a second surface 177, which forms an obtuse angle with the first surface 176; and a curved surface 178 formed between the first surface 176 and the second surface 177. The first surface 176 is formed at a position closer to the second surface 177 than the second surface 177. That is, the first surface 176 is located on the side closer to the external air than the second surface 177.

[0123] A recess 172a is formed in the second cylindrical portion 172, which is recessed from the outer periphery to the second inner side. The recess 172a is cuboid in shape and is formed in a portion of the circumference.

[0124] The end face of the first cylindrical portion 171 of the outer housing 170, which serves as the first side, is shaped along the outer peripheral surface of the damper housing 13 of the cylinder portion 10. The outer peripheral portion of the first cylindrical portion 171 is fixed to the damper housing 13, for example, by welding. An internal thread 179 is formed on the inner peripheral surface of the outer housing 170.

[0125] The outer peripheral surface 170a of the first cylindrical portion 171 is coated. The coating can be exemplified as a cationic electrodeposition coating with high corrosion resistance.

[0126] The inner housing 180 has a generally cylindrical cylindrical portion 181 and an annular portion 182 protruding from the inner circumference of the cylindrical portion 181 toward the second inner side.

[0127] An external thread 183 is formed at the end of the first side of the cylindrical portion 181, which is fastened to an internal thread 179 formed on the inner circumferential surface of the outer housing 170. In addition, a recess 184 is formed on the second side of the cylindrical portion 181, which is recessed from the outer circumferential surface, and an O-ring 185 is inserted into the recess 184 to seal between the outer circumferential surface of the inner housing 180 and the inner circumferential surface of the outer housing 170.

[0128] In addition, a first engaging portion 186 recessed from the inner circumference is formed throughout the entire circumference of the end of the second side of the cylindrical portion 181.

[0129] (Solenoid section 102)

[0130] The solenoid section 102 has a cover 120 that covers the opening of the housing 160 and a clamp 103 for axially positioning the cover 120 relative to the housing 160. Furthermore, the solenoid section 102 pushes the plunger 117 toward the first side by becoming energized.

[0131] The clamp 103 is a metal component. When cut with a plane parallel to the second axis, its cross-sectional shape is a rectangle with the axial direction as the short side and the radial direction as the long side. When cut with a plane perpendicular to the second axis, its cross-sectional shape is C-shaped.

[0132] The cover portion 120 includes a coil 121, a cover portion 130 that holds the coil 121 and covers the opening of the housing 160, a connector portion 122 for energizing the coil 121, and a connecting portion 123 that connects the cover portion 130 and the connector portion 122. The cover portion 120 is formed by filling inserts of the mold with resin heated to a softening temperature at the locations corresponding to the cover portion 130, connector portion 122, and connecting portion 123, while the metal coil 121 and the surrounding portion 150 are held in the mold. Therefore, the cover portion 130, connector portion 122, and connecting portion 123 are molded from molding resin.

[0133] The connecting portion 123 protrudes outward in a cuboid shape from the outer periphery of the covering portion 130. The connector portion 122 is provided such that it protrudes outward from the second outer end of the connecting portion 123 towards the first side.

[0134] The cover portion 130 has: a disc-shaped portion 131 that covers the opening of the housing 160; a peripheral portion 132 that protrudes from the disc-shaped portion 131 toward a first side and covers the periphery of the coil 121; and an enclosing portion 150 that encloses the periphery of the second outer side of the housing 160.

[0135] A recess 140 is formed on the outer periphery of the disc-shaped portion 131, recessed from the end face of the first side. The recess 140 is formed by a parallel surface 141 parallel to the second axis, a vertical surface 142 formed at the end of the second side perpendicular to the second axis, and a recess 143 recessed from the parallel surface 141 toward the second inner side.

[0136] The peripheral portion 132 is cylindrical and is located on the outer side of the second fixing member 112 and on the inner side of the housing 160. In addition, the peripheral portion 132 has a coil 121 at a position where it overlaps with the moving area of ​​the movable iron core 118 fixed to the plunger 117 in the second axial direction.

[0137] Furthermore, a second engaging portion 135, recessed from the outer peripheral surface, is formed throughout the entire circumference of the peripheral portion 132 at a location closer to the center of the second axial direction. The second engaging portion 135 is formed axially at a position corresponding to the first engaging portion 186 formed in the cylindrical portion 181 of the inner housing 180. A clamp 103 is embedded in both the second engaging portion 135 and the first engaging portion 186.

[0138] The surrounding portion 150 has a cylindrical first cylindrical portion 151 disposed on a first side, a cylindrical second cylindrical portion 152 disposed on a second side, and a connecting portion 153 connecting the first cylindrical portion 151 and the second cylindrical portion 152.

[0139] The inner diameter of the first cylindrical portion 151 is larger than the outer diameter of the first cylindrical portion 171 of the outer shell 170.

[0140] The inner diameter of the second cylindrical portion 152 is larger than the outer diameter of the second cylindrical portion 172 of the outer shell 170, but smaller than the outer diameter of the first cylindrical portion 171.

[0141] The connecting portion 153 is a portion that is inclined relative to the axial direction in such a way that the diameter of the inner surface gradually increases from the second side toward the first side. The connecting portion 153 is arranged opposite to the inclined surface 173 of the first cylindrical portion 171.

[0142] A first protrusion 155 is provided at the end of the first side of the second cylindrical portion 152, protruding from the inner circumference towards the second inner side. The first protrusion 155 is cuboid in shape and is formed in a portion of the circumference. Furthermore, the circumferential position of the cover portion 120 relative to the outer housing 170 is determined by the first protrusion 155 being inserted into the recess 172a formed in the outer housing 170.

[0143] Additionally, a second protrusion 156 is provided at the end of the second side of the second cylindrical portion 152, protruding from the inner circumference towards the second inner side.

[0144] The surrounding portion 150 can be made of a metallic material such as iron, stainless steel, aluminum, or brass. Furthermore, the surrounding portion 150 is held in the disc-shaped portion 131 by the second protrusion 156 being inserted into the recess 143 of the disc-shaped portion 131. Furthermore, an example is shown where the surrounding portion 150 and the covering portion 130 are integrated by insert molding as described above; however, the surrounding portion 150 can also be inserted later into the recess 143 of the previously formed covering portion 130. When the second protrusion 156 is inserted into the recess 143, it can be elastically deformed in a way that expands the end of the second side of the surrounding portion 150. Thus, the disc-shaped portion 131 and the surrounding portion 150 can be securely integrated and then assembled onto the outer housing 170. Alternatively, the disc-shaped portion 131 and the surrounding portion 150 can also be connected by other methods such as bonding or welding.

[0145] The surrounding portion 150 was coated. The coating can be exemplified as a highly corrosion-resistant cationic electrodeposition coating.

[0146] The sealing member 190 can be exemplified as an O-ring molded from a rubber-based material. The inner diameter of the sealing member 190 is smaller than the outer diameter of the first cylindrical portion 171 of the outer housing 170. The outer diameter of the sealing member 190 is larger than the inner diameter of the first cylindrical portion 151 of the surrounding portion 150. With the cover portion 120 installed on the outside of the outer housing 170 of the housing 160, the sealing member 190 is sandwiched between the surrounding portion 150 and the outer housing 170, and contacts the inner circumferential surface, the first surface 176, and the second surface 177 of the first cylindrical portion 151 of the surrounding portion 150.

[0147] (Connecting flow path section 90)

[0148] like Figure 2 As shown, the connecting flow path 90 has a cylindrical portion 91 and a flange portion 92 that protrudes cylindrically from the outer peripheral surface all the way outward on the second side of the cylindrical portion 91.

[0149] The outer diameter of the cylindrical part 91 is smaller than the inner diameter of the protrusion 174 of the outer housing 170, and the inner diameter of the cylindrical part 91 is smaller than the inner diameter of the main valve seat 53.

[0150] The outer diameter of the flange portion 92 is larger than the inner diameter of the protrusion 174 of the outer housing 170, but smaller than the inner diameter of the first cylindrical portion 171. Furthermore, the flange portion 92 is disposed on the second side of the protrusion 174 of the outer housing 170. A second axial return hole 93 is formed in the flange portion 92. Multiple return holes 93 are formed in the circumferential direction.

[0151] The second inner side of the cylindrical portion 91 communicates with the outer cylinder opening 12H on the first side and with the second inner side of the main valve seat 53 on the second side. Furthermore, the second inner side of the cylindrical portion 91 forms part of the first flow path R1.

[0152] The reflux hole 93 communicates with the housing opening 13H on the first side and with the annular gap S1 on the second side.

[0153] The damping force generating device 50 configured as described above can be assembled using the assembly method described below. Specifically, after assembling the connecting flow path 90, main valve seat 53, main valve 52, elastic member 54, guide member 61, force-applying member 75, limiting member 72, first spacer member 73A, second spacer member 73B, third spacer member 73C, cover 80, and first fixing member 111 into the interior of the outer housing 170 fixed to the outer peripheral surface of the damper housing 13, the operator secures the inner housing 180 to the outer housing 170. Furthermore, the control valve 70 is configured such that its protrusion 703 and convex portion 706 are located between the force-applying member 75 and the limiting member 72, and a coil spring 79 is disposed on the second inner side of the control valve 70. In addition, the pressing member 77 is configured to be held in the plunger 117 such that the cylindrical part 701 of the pressing member 77 is located on the second inner side of the coil spring 79 and the flange part 773 is located on the second side of the coil spring 79.

[0154] Then, spacer 113 and second fixing member 112 are inserted into the second side of the first fixing member 111, and solenoid portion 102 is assembled. Before assembling solenoid portion 102, sealing member 190 is inserted into groove 175 of outer housing 170.

[0155] In the damping force generating device 50 configured as described above, an annular gap S1 is formed between the inner peripheral surface of the first cylindrical portion 171 of the outer housing 170 and the outer peripheral surface of the cylindrical portion 62 of the guide member 61.

[0156] In addition, such as Figure 7 As shown, a first flow path R1 is formed, in which oil flows to the storage chamber R through the connecting passage L, the second inner side of the cylindrical part 91 connecting the flow path 90, between the main valve 52 and the main valve seat 53, the transverse hole 64 of the guide member 61, the annular gap S1, and the return hole 93 connecting the flange part 92 of the flow path 90.

[0157] In addition, such as Figure 7 As shown, a second flow path R2 is formed. The second flow path R2 branches from the upstream of the main valve 52 in the first flow path R1, passes through the inlet hole 526 of the bottom 522 of the main valve 52, the through hole 69 of the top 65 of the guide member 61, the second inner side of the third cylindrical part 83 of the cover 80, the second radial direction groove 85, and the second axial groove 84 to reach the annular gap S1 and merge with the first flow path R1.

[0158] Furthermore, the outer peripheral surface of the cylindrical portion 521 of the main valve 52 and the inner peripheral surface of the cylindrical portion 62 of the guide member 61 are sealed by the sealing member 55. In other words, the groove 525 formed on the outer peripheral surface of the cylindrical portion 521 of the main valve 52 and the sealing member 55 constitute a sealing mechanism 56 that seals the outer peripheral surface of the cylindrical portion 521 of the main valve 52 and the inner peripheral surface of the cylindrical portion 62 of the guide member 61. Therefore, a back pressure chamber 61P is formed in the guide member 61 at a portion that is second to the main valve 52. This back pressure chamber 61P causes the pressure of the oil from the second side, which is the opposite side of the main valve seat 53 (hereinafter, sometimes referred to as "back pressure") to act on the main valve 52.

[0159] [Adjustment action of damping force adjustment unit 60]

[0160] Next, the adjustment operation of the damping force adjustment unit 60 will be explained.

[0161] By pressing the pressing member 77 toward the first side, the control valve 70 is pressed against the second protrusion 663 of the guide member 61. Furthermore, the pressing force of the pressing member 77, in other words, the solenoid portion 102 (refer to...) Figure 2 The thrust varies depending on the amount of current flowing through the solenoid section 102.

[0162] For example, in the damping force adjustment section 60, a state is formed in which the pressing force of the pressing member 77 is maximized. At this time, the control valve 70 is pressed most strongly relative to the second protrusion 663 of the guide member 61, and the second flow path R2 is closed.

[0163] Additionally, for example, in the damping force adjustment section 60, a state is formed in which the pressing force of the pressing member 77 is minimized. At this time, in the damping force adjustment section 60, the control valve 70 leaves the second protrusion 663 of the guide member 61, and the second flow path R2 is opened.

[0164] Furthermore, for example, in the damping force adjustment section 60, the pressing force of the pressing member 77 is set to a state between the minimum and the maximum state. In this state, in the damping force adjustment section 60, the control valve 70 is further away from the second protrusion 663 of the guide member 61 than in the state of maximum pressing force, and closer to the second protrusion 663 than in the state of minimum pressing force.

[0165] [Action of buffer device 2]

[0166] First, let’s explain the operation of the buffer device 2 during its extension stroke.

[0167] During the extension stroke, lever 20 moves to the other side relative to cylinder 11 (see reference). Figure 2 The piston valve 32 remains blocked at the piston oil passage 311. Furthermore, the volume of the second oil chamber Y2 decreases due to the movement of the piston part 30 to the other side. And, the oil in the second oil chamber Y2 flows out from the connecting hole 11H to the connecting passage L.

[0168] Furthermore, oil flows into the damping force generating device 50 through the connecting passage L and the outer cylinder opening 12H. In the damping force generating device 50, the oil first flows into the second inner side of the cylindrical portion 91 connecting the flow passage 90. Then, in the damping force generating device 50, damping force is generated in the main valve 52 or the control valve 70. The oil flow at this time will be described in detail later.

[0169] Then, the oil flowing to the main valve 52 or control valve 70 flows out through the annular gap S1. Furthermore, the oil flows into the storage chamber R from the housing opening 13H through the return hole 93 of the flange portion 92 connecting the flow path portion 90.

[0170] In addition, the pressure in the first oil chamber Y1 is relatively lower than that in the storage chamber R. Therefore, the oil in the storage chamber R flows into the first oil chamber Y1 through the bottom 40.

[0171] Next, the operation of the buffer device 2 during the compression stroke will be explained.

[0172] During the compression stroke, rod 20 moves to one side relative to cylinder 11 (see reference). Figure 2 Relative movement occurs. In the piston section 30, the piston valve 32, which blocks the piston oil passage 311, opens due to the differential pressure between the first oil chamber Y1 and the second oil chamber Y2. Oil from the first oil chamber Y1 then flows out through the piston oil passage 311 into the second oil chamber Y2. Here, a rod 20 is disposed 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 connecting passage L.

[0173] Furthermore, oil flows into the damping force generating device 50 through the connecting passage L and the outer cylinder opening 12H. In addition, the oil flow in the damping force generating device 50 is the same as the oil flow during the extension stroke described above. That is, in the buffer device 2 of the first embodiment, the direction of oil flow in the damping force generating device 50 is the same during both the compression and extension strokes.

[0174] As described above, in the buffer device 2, damping force is generated by the damping force generating device 50 during both the compression stroke and the extension stroke.

[0175] The generation of damping force in the damping force generating device 50 will be described in detail below.

[0176] (Normally)

[0177] The flow of oil under normal conditions, when the solenoid section 102 is energized and the pressing force of the pressing member 77 is applied, will be described.

[0178] (At low speed)

[0179] Figure 6 This indicates the piston portion 30 (see reference) in the state where the pressing force of the pressing member 77 is minimized. Figure 1 The figure shows an example of oil flow at a low speed.

[0180] like Figure 6 As shown, when the piston section 30 moves at a low speed, the oil flowing to the second inner side of the cylindrical section 91 connecting the flow path section 90 flows into the second inner side of the main valve seat 53. Here, since the piston section 30 moves at a low speed, the oil flowing to the second inner side of the main valve seat 53 flows into the first flow path R1 (refer to...). Figure 7 No oil flow is generated in the main valve 52 during the process.

[0181] On the other hand, such as Figure 6 As indicated by the arrow, the oil flowing into the second inner side of the main valve seat 53 flows in the second flow path R2. Then, the oil flows out from the annular gap S1 into the storage chamber R.

[0182] As described above, when the piston 30 moves at a low speed, a damping force is generated by throttling the flow of oil using the gap between the control valve 70 and the second protrusion 663 of the guide member 61.

[0183] (At high speed)

[0184] Figure 7 This indicates the piston portion 30 (see reference) in the state where the pressing force of the pressing member 77 is minimized. Figure 1 The figure shows an example of oil flow at a high speed.

[0185] like Figure 7 As shown, when the piston 30 moves at a high speed, the oil flowing to the second inner side of the cylindrical portion 91 connecting the flow path portion 90 flows into the second inner side of the main valve seat 53. The oil flowing into the second inner side of the main valve seat 53 opens the main valve 52 and flows out into the storage chamber R.

[0186] Furthermore, when the moving speed is high, the oil flowing into the second inner side of the main valve seat 53 is also, in the same way as at low speed, throttled by the gap between the control valve 70 and the second protrusion 663 of the guide member 61 to generate differential pressure and flow to the annular gap S1, and then flows out to the storage chamber R.

[0187] As described above, when the piston section 30 moves at a high speed, the damping force is mainly generated by the flow of oil in the first flow path R1 between the main valve 52 and the main valve seat 53.

[0188] Furthermore, the oil flowing into the second inner side of the main valve seat 53 transmits pressure to the back pressure chamber 61P through the inlet hole 526 at the bottom 522 of the main valve 52. However, the second flow path R2, which communicates with the back pressure chamber 61P, is in a state where it is open by the control valve 70. Therefore, the pressure in the back pressure chamber 61P is lower than when the control valve 70 is pressed against the second protrusion 663 of the guide member 61. Moreover, the main valve 52, which is under pressure through the back pressure chamber 61P, easily opens the first flow path R1. Therefore, in the state where the pressing force of the pressing member 77 is at its minimum, the damping force generated by the flow of oil in the first flow path R1 of the main valve 52 is lower than in the state where the pressing force of the pressing member 77 is at its maximum.

[0189] (At low speed)

[0190] Figure 8 This indicates the piston portion 30 (see reference) in the state where the pressing force of the pressing component 77 is at its maximum. Figure 1 The figure shows an example of oil flow at a low speed.

[0191] like Figure 8 As shown, when the piston 30 moves at a low speed, the oil flowing to the second inner side of the cylindrical portion 91 connecting the flow path portion 90 flows into the second inner side of the main valve seat 53. Here, because the piston 30 moves at a low speed, the main valve 52 will not open in the first flow path R1 (refer to...). Figure 9 The flow of oil in the container.

[0192] On the other hand, such as Figure 8As indicated by the arrow, the oil flowing into the second inner side of the cylindrical portion 91 of the connecting flow path 90 flows in the second flow path R2 through the inlet hole 526 at the bottom 522 of the main valve 52. Then, the oil flows out from the annular gap S1 into the storage chamber R.

[0193] As described above, when the piston 30 moves at a low speed, the control valve 70 is opened by oil and flows in the second flow path R2, generating a damping force. The damping force when flowing in the second flow path R2 is higher than when the control valve 70 leaves the second protrusion 663 of the guide member 61.

[0194] (At high speed)

[0195] Figure 9 This indicates the piston portion 30 (see reference) in the state where the pressing force of the pressing component 77 is at its maximum. Figure 1 The figure shows an example of oil flow at a high speed.

[0196] like Figure 9 As shown, when the piston 30 moves at a high speed, the oil flowing to the second inner side of the cylindrical portion 91 connecting the flow path portion 90 flows into the second inner side of the main valve seat 53. The oil flowing into the second inner side of the main valve seat 53 opens the main valve 52 and flows out into the storage chamber R.

[0197] Furthermore, when the moving speed is high, the oil flowing into the second inner side of the cylindrical part 91 of the connecting flow path part 90 also flows to the annular gap S1 and then out to the storage chamber R, just like when the pressing force of the pressing member 77 is at its minimum. This is achieved by throttling the flow rate through the gap between the second protrusion 663 of the guide member 61 and the control valve 70.

[0198] As described above, when the piston section 30 moves at a high speed, the damping force is mainly generated by the flow of oil in the first flow path R1 between the main valve 52 and the main valve seat 53.

[0199] Furthermore, oil flowing into the second inner side of the cylindrical portion 91 of the connecting flow path 90 transmits pressure to the back pressure chamber 61P through the inlet hole 526 at the bottom 522 of the main valve 52. Also, the second flow path R2, communicating with the back pressure chamber 61P, is in a state where the control valve 70 is pressed against the second protrusion 663 of the guide member 61. Therefore, the pressure in the back pressure chamber 61P, for example... Figure 7 The second flow path R2 is open when the pressure is high. Furthermore, the main valve 52, which is stressed by the oil in the back pressure chamber 61P, has difficulty opening the first flow path R1. Therefore, when the pressing force of the pressing member 77 is at its maximum, the damping force generated by the flow of oil in the first flow path R1, which opens the main valve 52, is higher than when the pressing force of the pressing member 77 is at its minimum.

[0200] As described above, in the buffer device 2, the damping force is adjusted both at low speeds and at high speeds by operating the pressing member 77. That is, the buffer device 2 adjusts the flow path area of ​​the second flow path R2, which serves as the oil flow path at low speeds, and the flow path area of ​​the second flow path R2, which is related to the oil flow path area at high speeds, by changing the pressing force of the control valve 70 on the second protrusion 663 of the guide member 61 using the pressing member 77.

[0201] Furthermore, in the above-described operation example, two modes were described: the minimum and maximum pressing force of the pressing member 77. However, the operation is not limited to these two modes. The pressing force of the pressing member 77 can be arbitrarily set within an adjustable range based on the current applied to the solenoid section 102, or in other words, the thrust of the solenoid section 102. Moreover, along with this setting, the damping force adjustment unit 60 can also perform multiple stages of adjustment for the damping force at low speeds and at high speeds.

[0202] (In case of anomalies)

[0203] Next, the flow of oil will be described when the solenoid section 102 is in an abnormal state and the pressing force of the pressing member 77 does not function. As an example of the case where the solenoid section 102 is in an abnormal state, the current supply to the coil of the solenoid section 102 is stopped, for example, due to a broken wire.

[0204] Figure 10 This indicates that the solenoid section 102 is in a non-energized state and the piston section 30 (see reference) Figure 1 The figure shows an example of oil flow at a low speed.

[0205] Figure 11 This diagram illustrates an example of oil flow when the solenoid section 102 is not energized and the piston section 30 moves at a high speed.

[0206] like Figure 10 and Figure 11 As shown, when the solenoid section 102 is not energized, the plunger 117 is pushed back to the second side by the helical spring 79. Simultaneously, the pressing member 77 fixed to the plunger 117 is pressed against the cover section 80.

[0207] (At low speed)

[0208] like Figure 10 As shown, when the piston 30 moves at a low speed, the oil flowing into the second inner side of the cylindrical part 91 connecting the flow path part 90 flows in the second flow path R2 and flows out from the annular gap S1 to the storage chamber R.

[0209] Furthermore, when the piston 30 moves at a low speed, damping force is generated by the flow of oil in the gap formed between the flange 773 of the pressing member 77 and the cover 80, i.e., the groove 831.

[0210] (At high speed)

[0211] like Figure 11 As shown, when the piston 30 moves at a high speed, the oil flowing to the second inner side of the cylindrical part 91 connecting the flow path part 90 opens the main valve 52 and flows out into the storage chamber R.

[0212] Furthermore, when the moving speed is high, the oil flowing into the second inner side of the cylindrical portion 91 of the connecting flow path portion 90 is also, in the same way as at low speed, generated by the differential pressure generated by the flow rate being throttled by the groove portion 831 formed in the cover portion 80 and flowing to the annular gap S1, and then flowing out into the storage chamber R.

[0213] As described above, when the piston section 30 moves at a high speed, the damping force is mainly generated by the flow of oil in the first flow path R1.

[0214] Here, oil flowing into the second inner side of the cylindrical portion 91 of the connecting flow path 90 transmits pressure to the back pressure chamber 61P through the inlet hole 526 of the bottom 522 of the main valve 52. The back pressure chamber 61P is connected to the annular gap S1 via the second flow path R2. The flow of oil between the back pressure chamber 61P and the annular gap S1 needs to pass through the groove 831 formed in the cover portion 80. Furthermore, by utilizing the groove 831 formed in the cover portion 80 to throttle the flow of oil, the outflow of oil from the back pressure chamber 61P is suppressed, and the pressure of the back pressure chamber 61P is maintained at a pressure higher than that of the main valve 52. Figure 7 The pressing member 77 shown is in a state of minimum pressing force, which is also a high state. Furthermore, the main valve 52, which is stressed by the oil in the back pressure chamber 61P, is more difficult to open the first flow path R1. Therefore, when the solenoid section 102 is not energized, the damping force generated by the flow of oil in the first flow path R1 of the main valve 52 is relatively high.

[0215] As described above, in the buffer device 2 of the first embodiment, even in an abnormal situation where the solenoid section 102 is not energized, the damping force at low speed and the damping force at high speed are both relatively high.

[0216] (Regarding the differences between normal and abnormal situations)

[0217] When the combined force of the force causing the control valve 70 to move to the second side through the through hole 69 of the guide member 61 and the force of the coil spring 79 exceeds the pressing force of the pressing member 77, the control valve 70 moves to the second side even when a thrust is generated in the solenoid section 102. In particular, in Figure 6 , Figure 7When the pressing force of the pressing component 77 is at its minimum, or when the thrust of the solenoid section 102 is relatively small, if the pressure of the oil through the through hole 69 of the guide component 61 increases, the control valve 70 temporarily moves to the second side.

[0218] In the damping force generating device 50, even if the control valve 70 moves to the second side, the limiting member 72 also inhibits the control valve 70 from moving to the second side. In other words, when the protrusion 703 contacts the limiting member 72, the control valve 70 receives a force from the limiting member 72 in the direction of the first side, and movement to the second side is inhibited.

[0219] Furthermore, the cylindrical portion 771 and bottom 772 of the pressing member 77 are disposed on the second inner side of the cylindrical portion 701 and the conical portion 702 of the control valve 70. The diameter of the outer periphery of the flange portion 773 of the pressing member 77 is less than the outer diameter of the cylindrical portion 701 of the control valve 70. Therefore, the pressing member 77 is unlikely to be subjected to the force of oil flowing to the third cylindrical portion 83 of the cover portion 80 through the through hole 69 of the guide member 61. As a result, the pressing member 77 is also suppressed from moving to the second side, and thus it is easy to remain stably in the normal operating position, and it is difficult for it to be in the abnormal operating position, that is, the state in which the pressing member 77 is pressed against the cover portion 80.

[0220] Thus, in the damping force generating device 50 of this embodiment, under normal conditions, even if the combined force of the oil causing the control valve 70 to move to the second side and the force of the coil spring 79 exceeds the thrust of the solenoid portion 102, it is difficult for the pressing member 77 to be pressed against the cover portion 80. That is, in the damping force generating device 50, under normal conditions, unlike the abnormal operation, it is difficult for the pressing member 77 to be pressed against the cover portion 80. Therefore, according to the damping force generating device 50, although the mechanism can operate normally, it is possible to prevent abnormal operation, and in the event of an abnormality in the mechanism, it is possible to perform abnormal operation. In addition, even if the flow path cross-sectional area formed in the groove portion 831 of the cover portion 80 is changed in order to adjust the damping force generated under abnormal conditions, it is possible to ensure that the change does not affect the damping force under normal conditions.

[0221] As explained above, the damping force generating device 50 is an example of a damping force adjusting valve having a structural component (e.g., guide component 61) forming a through hole 69 extending along the second axial direction. Furthermore, the damping force generating device 50 includes a control valve 70 (an example of a first valve core), which is positioned opposite the opening on the second side of the through hole 69 (an example of an opening) in the second axial direction, and the distance between the control valve 70 and the opening on the second side of the through hole 69 can be adjusted by the solenoid portion 102 (an example of an actuator). Additionally, the damping force generating device 50 includes a back pressure chamber 61P that adjusts the internal pressure according to the second axial position of the control valve 70. Additionally, the damping force generating device 50 includes a main valve 52 (an example of a second valve core), which is subjected to pressure in the closing direction due to internal pressure. It has an inlet hole 526 (an example of a connecting hole) located off-axis from the central axis of the opening on the first side of the through hole 69 (an example of another opening), communicating with the back pressure chamber 61P, and is guided by the guide member 61 to move along the second axial direction. Furthermore, the damping force generating device 50 includes a main valve seat 53 (an example of a valve seat) into which the main valve 52 can be seated.

[0222] The damping force generating device 50, configured as described above, does not overlap with the region of the inlet hole 526 formed in the main valve 52 and the region of the through hole 69 formed in the control valve 70. Therefore, it is possible to suppress the control valve 70 from accidentally opening due to the dynamic pressure of the oil passing through the inlet hole 526. As a result, the opening and closing of the control valve 70 can be controlled with high precision, and the damping force can be adjusted with high precision.

[0223] Furthermore, multiple inlet holes 526 are formed in the main valve 52, with multiple holes located around the central axis. In other words, multiple inlet holes 526 are formed around the centerline of the through hole 69 formed in the guide member 61. Therefore, for example, compared to the case where only one inlet hole 526 is formed, the dynamic pressure generated by the oil acting on the main valve 52 and entering the second inner side of the main valve seat 53 from the connecting passage L is less likely to be biased towards one part. As a result, it is possible to suppress the tilting of the main valve 52 relative to the second axis. In other words, it is possible to suppress the tilting of the centerline of the cylindrical portion 521 of the main valve 52 relative to the centerline of the cylindrical portion 62 of the guide member 61. In addition, the inlet holes 526 can also be provided at an angle.

[0224] Figure 12 This is an enlarged view showing an example of the structure of the main valve 52, the guide component 61, and the sealing mechanism 56.

[0225] Furthermore, the damping force generating device 50 provides a sealing mechanism 56 on the portion of the main valve 52 that is always opposite to the guide member 61. As the main valve 52 moves away from the sealing mechanism 56 along the second axial direction, the outer diameter of the main valve 52 smoothly decreases. In other words, the gap between the portion of the main valve 52 that is opposite to the cylindrical portion 62 of the guide member 61 and the cylindrical portion 62 of the guide member 61 increases as the main valve 52 moves away from the sealing mechanism 56 along the second axial direction. Therefore, even if the main valve 52 tilts relative to the second axial direction due to dynamic pressure, etc., corner contact between the main valve 52 and the cylindrical portion 62 of the guide member 61 can be suppressed, thus allowing the main valve 52 to move smoothly along the second axial direction.

[0226] Here, the sealing mechanism 56 consists of a groove 525 (an example of an annular groove) formed on the outer periphery of the main valve 52 and a sealing member 55 disposed in the groove 525. A third flow path R3 (an example of a passage) is formed in the groove 525 and / or the sealing member 55 to introduce pressure into the back pressure chamber 61P into the pressure chamber 57 (an example of a pressing chamber). The pressure chamber 57 generates a force that is applied to the sealing member 55 and the guide member 61. As a result, a high-precision seal can be achieved between the main valve 52 and the cylindrical portion 62 of the guide member 61, thus enabling high-precision adjustment of the damping force.

[0227] The structural component with a through hole 69 extending along the second axis is formed as a bottomed cylindrical shape, which also serves as a guide component 61. In this way, the part that guides the movement of the main valve 52 and the part where the control valve 70 sits are integrally formed, thus enabling the generation and adjustment of damping force with a simple structure.

[0228] Furthermore, the buffer device 2 includes: a cylinder 11 containing fluid; a piston portion 30 (an example of a piston) slidably fitted into the cylinder 11; and a rod 20 (an example of a piston rod) connected to the piston portion 30 and extending to the outside of the cylinder 11. Additionally, the buffer device 2 is an example of a damping force adjustable buffer with a damping force generating device 50, which controls the flow of fluid generated by the sliding of the piston portion 30 within the cylinder 11 to generate damping force. With the buffer device 2 configured as described above, the opening and closing of the control valve 70 can be controlled with high precision, thus allowing for high-precision adjustment of the damping force.

[0229] Label Explanation

[0230] 1: Suspension device; 2: Buffer device; 10: Cylinder section; 11: Cylinder; 20: Rod; 30: Piston section; 50: Damping force generating device; 51: Main valve section; 52: Main valve (an example of a second valve core); 53: Main valve seat (an example of a valve seat); 54: Elastic component; 55: Sealing component (an example of a sealing mechanism); 57: Pressure chamber; 60: Damping force adjustment section; 61: Guide component (an example of a structural component); 61P: Back pressure chamber; 6 2: Cylindrical portion (an example of a cylindrical portion), 65: Top (an example of a covering portion), 66: Central portion (an example of a restricting portion), 67: Outer periphery, 69: Through hole, 70: Control valve (an example of a first valve core), 525: Groove (an example of a sealing mechanism), 526: Inlet hole (an example of a connecting hole), 550: Seam, 663: Second protrusion, 664: Recess, R1: First flow path, R2: Second flow path, R3: Third flow path.

Claims

1. A damping force regulating valve, comprising: Structural component having a through hole extending along the axial direction; The first valve core is axially opposed to an opening of the through hole, and the distance between it and the opening can be adjusted by an actuator. The back pressure chamber adjusts its internal pressure according to the axial position of the first valve core; A second valve core, which is pressurized in the closing direction by the internal pressure, and has a communication hole communicating with the back pressure chamber at a position offset from the central axis of another opening of the through hole; the second valve core is guided by a guide member to move axially; and A valve seat that allows the second valve core to be seated.

2. The damping force adjusting valve according to claim 1, wherein, The connecting holes are provided in multiple locations, with multiple holes located centered on the central axis.

3. The damping force adjusting valve according to claim 1, wherein, A sealing mechanism is provided on the portion of the second valve core that is always opposite to the guide member. As the second valve core moves axially away from the sealing mechanism, the outer diameter of the second valve core smoothly decreases.

4. The damping force adjusting valve according to claim 3, wherein, The sealing mechanism consists of an annular groove formed on the outer periphery of the second valve core and a sealing member disposed in the annular groove. A passage is formed in the annular groove and / or the sealing member to introduce pressure into the back pressure chamber, and the pressing chamber generates a force applied to the sealing member by the guiding member.

5. The damping force adjusting valve according to claim 3, wherein, The structural component is formed into a bottomed cylindrical shape and also serves as the guiding component.

6. A damping force adjustable buffer, which has the following characteristics: A cylinder, which is sealed with fluid; A piston that is slidably fitted into the cylinder; A piston rod, which is connected to the piston and extends to the outside of the cylinder; and A damping force adjusting valve generates damping force by controlling the flow of fluid generated by the sliding of the piston within the cylinder. The damping force regulating valve has the following characteristics: A bottom cylindrical structural component with an axially penetrating through hole formed at the bottom; The first valve core is adjustable by an actuator to the distance between itself and an opening of the through hole; The back pressure chamber adjusts its internal pressure according to the axial position of the first valve core; A second valve core, which is pressurized in the closing direction by the internal pressure, and has a communication hole communicating with the back pressure chamber at a position offset from the central axis of the through hole, is guided axially by the cylindrical portion of the structural component; and A valve seat that allows the second valve core to be seated.

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