Buffer device and suspension device

Abstract

To provide a buffer device, etc. capable of reducing the number of components.SOLUTION: A buffer device includes: a first cylinder 11; a second cylinder 12; an intermediate cylinder 13; a piston part; a damping force regulating device 50 provided on the outer side of the second cylinder 12, having a valve mechanism V for restricting a flow passage of liquid and discharging the liquid moving along with movement of the piston part toward a reservoir chamber R while causing the liquid to pass through the valve mechanism V; a formation member 90 for forming a flow passage in which the liquid discharged from an opening part 130 flows toward the damping force regulating device 50; and a baffle plate 200 having a limitation part 220 disposed in the reservoir chamber R and limiting the movement of the liquid discharged from the damping force regulating device 50 to the reservoir chamber R and a seal part 230 for sealing a gap between the opening part 130 and the formation member 90.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to shock absorbers and suspension systems. [Background technology]

[0002] For example, the shock absorber described in Patent Document 1 includes a cylinder in which a working fluid is sealed, a piston slidably inserted into the cylinder and dividing the inside of the cylinder into an upper chamber and a lower chamber, and a piston rod whose one end is connected to the piston and whose other end extends to the outside of the cylinder. The shock absorber described in Patent Document 1 also includes an outer tube provided on the outer periphery of the cylinder, a reservoir formed between the cylinder and the outer tube, an intermediate tube provided on the outer periphery of the cylinder and whose both ends are fitted into the cylinder, and an annular flow path formed between the cylinder and the intermediate tube. The shock absorber described in Patent Document 1 also includes a communication passage provided on a side wall of the cylinder and communicating the upper chamber of the cylinder with the annular flow path, a connecting tube provided on a side wall of the intermediate tube, an opening provided on a side wall of the outer tube and opening at a position opposite to the connecting tube, and a damping force adjustment mechanism connected to the connecting tube. In addition, the shock absorber described in Patent Document 1 includes a partition member provided within the reservoir and having a partition portion that controls the flow direction of hydraulic fluid that flows from the opening to the reservoir through the upper cylinder chamber, the connecting passage, the annular flow passage, and the damping force adjustment mechanism. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2023-86376 A Summary of the Invention [Problem to be solved by the invention]

[0004] It is desirable to reduce the number of parts in a shock absorber, because a reduction in the number of parts reduces the number of steps required to assemble the shock absorber, thereby improving productivity. An object of the present invention is to provide a shock absorber and the like that can reduce the number of parts. [Means for solving the problem]

[0005] The present invention, which was completed with respect to this object, is a shock absorber comprising: a first cylinder that contains liquid; a second cylinder arranged radially outward of the first cylinder; an intermediate cylinder arranged between the first and second cylinders, forming a liquid reservoir portion in which liquid accumulates in a gap between the first cylinder and the second cylinder and having an opening through which liquid is discharged from the gap between the first cylinder and the intermediate cylinder; a piston portion arranged within the first cylinder and partitioning a space within the first cylinder; a damping force adjuster provided outside the second cylinder and having a throttle portion that throttles a liquid flow path, and discharging liquid that moves with the movement of the piston portion toward the liquid reservoir portion while passing through the throttle portion; a forming member that forms a flow path for the liquid discharged from the opening toward the damping force adjuster; and a limiting member arranged in the liquid reservoir portion, having a limiting portion that limits the movement of the liquid discharged from the damping force adjuster to the liquid reservoir portion, and a sealing portion that seals the gap between the opening and the forming member. Effect of the Invention

[0006] According to the present invention, it is possible to provide a shock absorber and the like that can reduce the number of parts. [Brief description of the drawings]

[0007] [Figure 1] 1 is a diagram showing an example of a schematic configuration of a suspension device according to a first embodiment. [Diagram 2] FIG. 2 is an example of an enlarged view of a part II in FIG. [Diagram 3] 5A and 5B are diagrams illustrating an example of an oil flow in the damping force adjusting device. [Figure 4]FIG. 2 is a perspective view of a baffle plate as viewed from the outside. [Diagram 5] FIG. 2 is a perspective view of a baffle plate as viewed from the inside. [Figure 6] FIG. 11 is a diagram showing an example of a schematic configuration of a baffle plate according to a second embodiment. [Figure 7] FIG. 13 is a diagram showing an example of a schematic configuration of a baffle plate according to a third embodiment. [Figure 8] FIG. 13 is a diagram showing an example of a modified example of a baffle plate. [Figure 9] FIG. 13 is a diagram illustrating an example of a schematic configuration of a shock absorber according to a fourth embodiment. [Figure 10] FIG. 13 is a diagram illustrating an example of a schematic configuration of a shock absorber according to a fifth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. First Embodiment FIG. 1 is a diagram showing an example of a schematic configuration of a suspension device 1 according to the first embodiment. FIG. 2 is an example of an enlarged view of part II in FIG. FIG. 3 is a diagram showing an example of the flow of oil in the damping force adjusting device 50. As shown in FIG. The suspension system 1 is a suspension used in four-wheeled vehicles such as passenger automobiles, and as shown in Fig. 1, comprises a hydraulic shock absorber 2 and a coil spring 3 arranged on the outside of the shock absorber 2. The suspension system 1 also comprises a lower spring sheet 4 that supports an end of the coil spring 3 on one side in the axial direction (the lower side in Fig. 1) of a rod 20 described below, and an upper spring sheet 5 that supports an end of the coil spring 3 on the other side in the axial direction of the rod 20 (the upper side in Fig. 1).

[0009] The suspension device 1 also includes a vehicle body side bracket 6 for mounting the suspension device 1 to a vehicle, a wheel side bracket 7 for mounting the suspension device 1 to a wheel, and a dust cover 8 that covers at least a portion of the cylinder portion 10 and the rod 20. Hereinafter, the axial direction of the rod 20 may be simply referred to as the "axial direction." Also, one side in the axial direction (lower side in FIG. 1) and the other side in the axial direction (upper side in FIG. 1) may be simply referred to as the "one side" and the "other side," respectively. Also, a direction intersecting the axial direction (e.g., a perpendicular direction) may be simply referred to as the "radial direction." In the radial direction, the side of the center line of a first cylinder 11 described later may be simply referred to as the "inner side," and the side away from the center line may be simply referred to as the "outer side."

[0010] The shock absorber 2 includes a cylinder portion 10 that contains oil as an example of a liquid, and a rod 20 that has one side that is slidably inserted into the cylinder portion 10 and the other side that is provided so as to protrude from the cylinder portion 10. The shock absorber 2 also includes a piston portion 30 that is provided at one end of the rod 20, and a bottom portion 40 that is provided at one end of the cylinder portion 10. The shock absorber 2 further includes a damping force adjusting device 50 that is provided outside the cylinder portion 10 and adjusts the damping force, and a baffle plate 200 that controls the direction of oil flowing from the damping force adjusting device 50 to a reservoir chamber R that will be described later.

[0011] (Cylinder section 10) The cylinder section 10 has a first cylinder 11 that contains oil, a second cylinder 12 that is disposed radially outside the first cylinder 11, and an intermediate cylinder 13 that is disposed between the first cylinder 11 and the second cylinder 12. The cylinder section 10 also has a rod guide section 14 that movably supports the rod 20, a bump stopper cap 15, and an oil seal 16 that prevents foreign matter from entering the cylinder section 10.

[0012] The first cylinder 11 is formed in a cylindrical shape, and has a radial through hole 11H formed at the other end. The second cylinder 12 is formed in a cylindrical shape. A radial through hole 12H is formed in the second cylinder 12 at a position where the damping force adjusting device 50 is attached. A reservoir chamber R in which oil is stored is formed between the second cylinder 12 and the intermediate cylinder 13. The reservoir chamber R absorbs oil in the first cylinder 11 and supplies oil to the first cylinder 11 as the rod 20 moves relative to the first cylinder 11. The reservoir chamber R also stores oil that flows out from the damping force adjusting device 50.

[0013] The intermediate cylinder 13 is formed in a cylindrical shape. The intermediate cylinder 13 forms a communication path L between the intermediate cylinder 13 and the first cylinder 11. The intermediate cylinder 13 is also formed with an opening 130 including a through hole 131 for discharging liquid from the communication path L and a protruding portion 132 provided around the through hole 131 and protruding cylindrically from an outer circumferential surface 135 of the intermediate cylinder 13. The opening 130 can be formed by pressing a cylindrical material that is the base of the intermediate cylinder 13. The through hole 131 may be formed by pressing a cylindrical material, and a cylindrical object that is separate from the material may be joined around the through hole 131. Oil, which is an example of a hydraulic fluid, is sealed inside the cylinder portion 10 configured as above. In addition, gas is sealed on the other side of the reservoir chamber R relative to the oil.

[0014] (Rod 20) The rod 20 is a rod-shaped member that extends long in the axial direction. One side of the rod 20 holds the piston portion 30. The other side of the rod 20 is connected to, for example, a vehicle body via a connecting member or the like (not shown).

[0015] (Piston part 30) The piston portion 30 has a piston body 31 having a plurality of piston oil passage ports 311, a piston valve 32 that opens and closes the other side of the piston oil passage ports 311, and a spring 33 provided between the piston valve 32 and one end of the rod 20. The piston portion 30 divides the oil in the first cylinder 11 into a first oil chamber Y1 and a second oil chamber Y2.

[0016] The bottom portion 40 has 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 on the other side. The bottom portion 40 separates the first oil chamber Y1 and the reservoir chamber R.

[0017] (Damping force adjusting device 50) The damping force adjusting device 50 includes a main valve section 51 that generates a damping force, a damping force adjusting section 60 that adjusts the magnitude of the damping force, and a forming member 90 that forms an oil flow path from the communication path L to the main valve section 51.

[0018] In the following description, the longitudinal direction of the damping force adjusting device 50 shown in Fig. 2 (i.e., the intersecting direction (e.g., a direction substantially perpendicular to) the axial direction of the cylinder section 10 (see Fig. 1)) may be referred to as the "second axial direction". In addition, the central axis side of the cylinder section 10 in the second axial direction (the lower side of the damping force adjusting device 50 in Fig. 2) may be referred to as the "first side", and the side away from the central axis of the cylinder section 10 (the upper side of the damping force adjusting device 50 in Fig. 2) may be referred to as the "second side". 2 (i.e., the direction intersecting with the second axial direction) may be referred to as the "second radial direction". In the second radial direction, the side of the center axis along the second axial direction may be referred to as the "second inner side", and the side away from the center axis along the second axial direction may be referred to as the "second outer side".

[0019] ((Main valve part 51)) The main valve section 51 has a main valve 52 that generates a damping force by controlling the flow of oil to throttle down, and a main valve seat 53 that faces the main valve 52 and comes into contact with it. The main valve section 51 also has an elastic member 54 that applies a force to press the main valve 52 against the main valve seat 53 by elastically deforming, and a seal member 55 that seals between the main valve 52 and a guide member 61, which will be described later.

[0020] The main valve 52 and the main valve seat 53 constitute a valve mechanism V that opens and closes a first flow path R1 through which oil flows from the communication path L to the reservoir chamber R through a horizontal hole 64 (described later) of the guide member 61. The valve mechanism V throttles the flow of oil in the first flow path R1 to generate a damping force.

[0021] ((Damping force adjustment unit 60)) The damping force adjusting unit 60 has a guide member 61 that guides the movement of the main valve 52 in the second axial direction, and a control valve 70 that moves relative to the guide member 61 to open and close a second flow path R2 formed in parallel with the first flow path R1. The damping force adjusting unit 60 also has a pressing member 77 that presses the control valve 70 against the guide member 61, a coil spring 79 that is disposed between the control valve 70 and the pressing member 77, and a solenoid 100 that moves the pressing member 77 toward and away from the guide member 61. The damping force adjusting unit 60 also has a restricting member 72 that restricts the movement of the control valve 70 toward the second side, and a biasing member 75 that applies a force to the control valve 70 in a direction opposite to the thrust of a solenoid unit 102 described later. The damping force adjuster 60 also has a first spacer member 73A interposed between the biasing member 75 and the restricting member 72, a second spacer member 73B interposed between the restricting member 72 and a cap portion 80 (described later), and a third spacer member 73C interposed between the guide member 61 and the biasing member 75. The damping force adjuster 60 also has a cap portion 80 that covers the periphery of the control valve 70, the restricting member 72, the first spacer member 73A, the second spacer member 73B, and the third spacer member 73C.

[0022] The solenoid 100 comprises a valve portion 101 that opens and closes the second flow path R2, a solenoid portion 102 that drives a plunger 117 of the valve portion 101, which will be described later, and a housing 160 that accommodates the valve portion 101, a coil 121 of the solenoid portion 102, which will be described later, and the like.

[0023] The valve portion 101 has a fixed portion 110 that is fixed, and a movable portion 116 that is movable relative to the fixed portion 110 . The fixed portion 110 has a first fixed member 111 provided on the first side, a second fixed member 112 provided on the second side of the first fixed member 111, and a spacer 113 provided between the first fixed member 111 and the second fixed member 112. The first fixed member 111 and the second fixed member 112 are molded using a magnetic material such as iron, and the spacer 113 is molded using a non-magnetic material such as resin. The movable portion 116 has a cylindrical plunger 117 that holds the pressing member 77 , and a movable iron core 118 that is held around the plunger 117 .

[0024] The solenoid portion 102 has a cover portion 120 that covers the opening of the housing 160. The cover portion 120 has a coil 121, a cover portion 125 that holds the coil 121 and covers the opening of the housing 160, a connector portion 122 for energizing the coil 121, and a connection portion 123 that connects the cover portion 125 and the connector portion 122. When the solenoid portion 102 is energized, it pushes the plunger 117 toward the first side. When the solenoid portion 102 is in a non-energized state, the plunger 117 is pulled back to the second side by the coil spring 79.

[0025] The housing 160 includes an outer housing 170 having a substantially cylindrical shape, and an inner housing 180 provided on the second inner side of the outer housing 170 . The outer housing 170 is fixed to the second cylinder 12 by, for example, welding. The outer housing 170 has, at the end on the first side, a protruding portion 174 that protrudes in an annular shape from the inner circumferential surface toward the second inside.

[0026] The inner housing 180 has a cylindrical portion 181 having a substantially cylindrical shape, and an annular portion 182 having an annular shape protruding from the inner circumferential surface of the cylindrical portion 181 toward the second inward direction. A male thread 183 is formed on the first end of the outer circumferential surface of the cylindrical portion 181, and is fastened to a female thread 179 formed on the inner circumferential surface of the outer housing 170. A recess 184 recessed from the outer circumferential surface is formed in the cylindrical portion 181 at a portion on the second side of the male thread 183. An O-ring 185 that seals between the outer circumferential surface of the inner housing 180 and the inner circumferential surface of the outer housing 170 is fitted in the recess 184.

[0027] ((Forming member 90)) As shown in FIG. 2, the forming member 90 has a cylindrical portion 91 and a flange portion 92 that cylindrically protrudes from the outer circumferential surface of the cylindrical portion 91 at the second end portion on the second side along the entire circumference toward the second outside. The cylindrical portion 91 has a first cylindrical portion 93 provided on the first side and a second cylindrical portion 94 provided on the second side. The first cylindrical portion 93 and the second cylindrical portion 94 have the same inner diameter but different outer diameters. The inner diameters of the first cylindrical portion 93 and the second cylindrical portion 94 are smaller than the inner diameter of the main valve seat 53, and the second inner sides of the first cylindrical portion 93 and the second cylindrical portion 94 communicate with the communication passage L on the first side and communicate with the second inner side of the main valve seat 53 on the second side. The outer diameter of the first cylindrical portion 93 is equal to or smaller than the inner diameter of an inner periphery 232 of a seal portion 230 of the baffle plate 200, which will be described later. The outer diameter of the second cylindrical portion 94 is larger than the inner diameter of the inner periphery 232 of the seal portion 230, and equal to or smaller than the inner diameter of a protruding portion 132 of an opening 130 of the intermediate cylinder 13. A chamfer 95 is formed on the outer peripheral surface of the end portion on the first side of the first cylindrical portion 93. In addition, the end face on the first side of the second cylindrical portion 94 functions as an abutment surface 96 that abuts against a seal portion 230 (described later) of the baffle plate 200, perpendicular to the second axial direction.

[0028] The outer diameter of the flange portion 92 is larger than the outer diameter of the guide member 61 and smaller than the inner diameter of the protruding portion 174 of the outer housing 170. The flange portion 92 is disposed on the second side of the protruding portion 174 of the outer housing 170.

[0029] In the damping force adjusting device 50 configured as above, an annular gap S1 is formed between the inner circumferential surface of the outer housing 170 and the outer circumferential surface of the guide member 61. The annular gap S1 communicates with the reservoir chamber R via the through hole 12H of the second cylinder 12. As shown in FIG. 3, a first flow path R1 is formed through which oil flows into the reservoir chamber R through the communication path L, the second inner side of the cylindrical portion 91 of the forming member 90, between the main valve 52 and the main valve seat 53, the horizontal hole 64 of the guide member 61, the annular gap S1, and the through hole 12H. As shown in FIG. 3, a second flow path R2 is formed, which branches off from the first flow path R1 upstream of the main valve 52, passes through the inlet hole 526 in the bottom 522 of the main valve 52, the through hole 69 in the guide member 61, the second inner side of the cap portion 80, the second radial groove 85, and the second axial groove 84, reaches the annular gap S1, and merges with the first flow path R1.

[0030] Additionally, the outer peripheral surface of the main valve 52 and the inner peripheral surface of the guide member 61 are sealed with a seal member 55. Therefore, the guide member 61 forms, at a portion inside the guide member 61 on the second side of the main valve 52, a back pressure chamber 61P that applies oil pressure (hereinafter sometimes referred to as "back pressure") from the second side opposite the main valve seat 53 to the main valve 52.

[0031] (Baffle Plate 200) FIG. 4 is an example of a perspective view of the baffle plate 200 as viewed from the outside. FIG. 5 is an example of a perspective view of the baffle plate 200 as seen from the inside. The baffle plate 200 has a thin plate-like base 210 provided along the outer circumferential surface 135 of the intermediate cylinder 13, and a restricting portion 220 protruding radially from the base 210 to restrict the direction of oil flow. The baffle plate 200 also has a sealing portion 230 that suppresses oil leakage from the communication passage L to the reservoir chamber R through a gap between the forming member 90 and the intermediate cylinder 13. The baffle plate 200 can be exemplified by a structure in which the base 210, the restricting portion 220, and the sealing portion 230 are integrally molded from a flexible elastic body such as NBR (nitrile rubber).

[0032] When viewed radially from the outside, the base 210 has a semicircular portion 211 having a semicircular shape centered on the center of the through hole 131 of the intermediate cylinder 13, and a rectangular portion 212 provided on one side (see FIG. 1) of the semicircular portion 211. When viewed in the axial direction (see FIG. 1), the semicircular portion 211 and the rectangular portion 212 are arc-shaped along the outer circumferential surface 135 of the intermediate cylinder 13.

[0033] The limiting portion 220 has a first limiting portion 221 provided on the outer periphery of the semicircular portion 211, and second limiting portions 222 provided on both ends of the rectangular portion 212 in the circumferential direction. 2, the first limiting portion 221 is formed so that the cross-sectional shape when cut along a plane parallel to the axial direction passing through the center of the through-hole 131 of the intermediate cylinder 13 (in other words, the center of the seal portion 230) is a right-angled triangle, and the side on the seal portion 230 side extends in the radial direction. The first limiting portion 221 has the cross-sectional shape shown in FIG. 2 over the entire outer periphery of the semicircular portion 211, and the first baffle surface 223, which is the surface on the seal portion 230 side, extends in the radial direction.

[0034] The second restriction portion 222 has a cross-sectional shape cut along a plane perpendicular to the axial direction that is the same as the cross-sectional shape of the first restriction portion 221 shown in Figure 2, and is formed so that the second baffle surface 224, which is the surface on the sealing portion 230 side, extends in the radial direction. With the baffle plate 200 attached to the intermediate cylinder 13, the radial tip ends of the first limiting portion 221 and the second limiting portion 222 of the limiting portion 220 come into contact with the inner circumferential surface of the second cylinder 12. The first baffle surface 223 prevents the oil that has flowed into the reservoir chamber R through the through hole 12H of the second cylinder 12 from moving toward the other side, and the second baffle surface 224 limits the circumferential movement of the oil.

[0035] The seal portion 230 protrudes in the radial direction from the base portion 210 so as to cover the opening 130 of the intermediate cylinder 13. More specifically, the seal portion 230 has a cylindrical outer peripheral portion 231 arranged on a second outer side (see FIG. 2) of the outer peripheral surface of the protruding portion 132 of the intermediate cylinder 13, a cylindrical inner peripheral portion 232 arranged on a second inner side of the inner peripheral surface of the protruding portion 132, and a second side portion 233 connecting the outer peripheral portion 231 and the inner peripheral portion 232, and the outer peripheral portion 231 protrudes in the radial direction from the base portion 210.

[0036] The diameter of the outer peripheral surface of the outer peripheral portion 231 is smaller than the diameter of the through hole 12H of the second cylinder 12, and the second side surface of the second side portion 233 (in other words, the surface that protrudes most from the base portion 210) is located inside the inner peripheral surface of the second cylinder 12. Therefore, a gap is formed between the through hole 12H of the second cylinder 12 and the seal portion 230, and oil flows from the annular gap S1 of the damping force adjusting device 50 into the reservoir chamber R through this gap.

[0037] The inner diameter of the inner circumferential portion 232 is equal to the outer diameter of the first cylindrical portion 93 of the forming member 90, and the first cylindrical portion 93 of the forming member 90 is fitted into the second inside of the inner circumferential portion 232. The forming member 90 is fitted into the sealing portion 230 until the abutment surface 96 of the second cylindrical portion 94 abuts against the second side surface of the second side portion 233 of the sealing portion 230.

[0038] Furthermore, the seal portion 230 has a protrusion 234 protruding from the outer circumferential surface of the inner circumferential portion 232 to a second outside. A plurality of protrusions 234 (two in FIG. 5 ) are provided at equal intervals in the circumferential direction. The plurality of protrusions 234 are fitted into recesses 133 recessed from the inner circumferential surface and formed in the protrusion 132 of the opening 130 of the intermediate cylinder 13.

[0039] The baffle plate 200, the intermediate cylinder 13, and the damping force adjusting device 50 configured as above can be assembled, for example, by using the assembly method described below. First, the baffle plate 200 is attached to the intermediate cylinder 13 so that the protrusion 132 of the intermediate cylinder 13 fits between the outer peripheral portion 231 and the inner peripheral portion 232 of the seal portion 230, and the protrusion 234 fits into the recess 133 formed in the protrusion 132 of the intermediate cylinder 13. Then, the intermediate cylinder 13 is inserted into the second cylinder 12 with the baffle plate 200 attached thereto.

[0040] Then, as shown in FIG. 2, the first cylindrical portion 93 of the forming member 90 is fitted into the second inner side of the inner periphery 232 of the baffle plate 200, and the forming member 90 is assembled to the baffle plate 200 until the abutment surface 96 of the second cylindrical portion 94 abuts against the second side surface of the second side portion 233 of the sealing portion 230. Then, inside the outer housing 170 of the second cylinder 12, the main valve seat 53, the main valve 52, the elastic member 54, the guide member 61, the biasing member 75, the restricting member 72, the first spacer member 73A, the second spacer member 73B, the third spacer member 73C, the cap portion 80, and the first fixing member 111 are assembled to the second side of the forming member 90, and then the inner housing 180 is fastened to the outer housing 170. In addition, the control valve 70 is disposed so that the protruding portion 703 (see FIG. 3) and the convex portion 706 (see FIG. 3) of the control valve 70 are positioned between the biasing member 75 and the restricting member 72, and the coil spring 79 is disposed on the second inner side of the control valve 70. In addition, the pressing member 77 held by the plunger 117 is positioned so that the cylindrical portion 771 (see Figure 3) of the pressing member 77 is positioned on the second inner side of the coil spring 79, and the flange portion 773 (see Figure 3) is positioned on the second side of the coil spring 79. Then, the spacer 113 and the second fixing member 112 are inserted into the second side of the first fixing member 111, and the solenoid portion 102 is assembled.

[0041] [Shock Absorber 2 Operation] First, the operation of the shock absorber 2 during the extension process will be described. During the extension stroke, the rod 20 moves to the other side (see FIG. 1) relative to the first cylinder 11. At this time, the piston valve 32 remains blocking the piston oil passage port 311. Furthermore, the movement of the piston portion 30 to the other side reduces the volume of the second oil chamber Y2. Then, the oil in the second oil chamber Y2 flows out from the through hole 11H to the communication passage L.

[0042] Furthermore, the oil flows into the damping force adjusting device 50 through the communication passage L and the opening 130 of the intermediate cylinder 13. In the damping force adjusting device 50, the oil first flows into the second inner side of the forming member 90. Then, a damping force is generated in the main valve 52 or the control valve 70.

[0043] Thereafter, the oil that has flowed into the main valve 52 or the control valve 70 flows out into the annular gap S1. Furthermore, the oil flows into the reservoir chamber R through the through hole 12H of the second cylinder 12. Furthermore, the pressure in the first oil chamber Y1 becomes lower relative to the pressure in the reservoir chamber R. Therefore, the oil in the reservoir chamber R passes through the bottom portion 40 and flows into the first oil chamber Y1.

[0044] Next, the operation of the shock absorber 2 during the compression stroke will be described. During the compression stroke, the rod 20 moves relative to the first cylinder 11 toward one side (see FIG. 1). In the piston portion 30, the piston valve 32 that closes the piston oil passage port 311 opens due to the pressure difference between the first oil chamber Y1 and the second oil chamber Y2. Then, the oil in the first oil chamber Y1 flows out through the piston oil passage port 311 to the second oil chamber Y2. Here, the rod 20 is disposed in the second oil chamber Y2. Therefore, the oil flowing from the first oil chamber Y1 to the second oil chamber Y2 is in excess by the volume of the rod 20. Therefore, an amount of oil equivalent to the volume of the rod 20 flows out from the through hole 11H of the first cylinder 11 to the communication passage L.

[0045] Furthermore, the oil flows into the damping force adjusting device 50 through the communication passage L and the opening 130 of the intermediate cylinder 13. The flow of oil in the damping force adjusting device 50 is similar to the flow of oil during the extension stroke described above. That is, in the shock absorber 2 of the first embodiment, the direction in which the oil flows in the damping force adjusting device 50 is the same during both the compression stroke and the extension stroke.

[0046] [Adjustment Operation of the Damping Force Adjusting Device 50] Next, the adjustment operation of the damping force adjusting device 50 will be described. By pressing the pressing member 77 toward the first side, the control valve 70 is pressed against the guide member 61. The pressing force of the pressing member 77, in other words, the thrust force of the solenoid portion 102 (see FIG. 2), changes depending on the amount of current flowing through the solenoid portion 102.

[0047] For example, a state in which the pressing force of the pressing member 77 is maximized is created in the damping force adjusting section 60. At this time, the control valve 70 is most strongly pressed against the guide member 61, and the second flow path R2 is closed. Also, for example, in the damping force adjusting section 60, a state is created in which the pressing force of the pressing member 77 is minimized. At this time, in the damping force adjusting section 60, the control valve 70 is separated from the guide member 61, and the second flow path R2 is opened.

[0048] Furthermore, for example, in the damping force adjustment unit 60, the pressing force of the pressing member 77 is set to a state between the smallest and largest states. In this state, in the damping force adjustment unit 60, the control valve 70 is farther away from the guide member 61 than in the state where the pressing force is largest, and is closer to the guide member 61 than in the state where the pressing force is smallest.

[0049] The back pressure is highest when the pressing force of the pressing member 77 is at its largest, and decreases as the pressing force of the pressing member 77 decreases. In this manner, by adjusting the amount of current flowing through the solenoid portion 102, it is possible to adjust the pressing force of the pressing member 77, and therefore the damping force of the shock absorber 2.

[0050] As described above, the shock absorber 2 includes the first cylinder 11 that contains liquid, the second cylinder 12 that is disposed radially outside the first cylinder 11, and the intermediate cylinder 13 that is disposed between the first cylinder 11 and the second cylinder 12. The intermediate cylinder 13 forms a reservoir chamber R (an example of a liquid reservoir) in which oil is stored in a gap between the second cylinder 12, and is formed with an opening 130 that discharges oil from the gap between the first cylinder 11. The shock absorber 2 also includes a piston portion 30 that is disposed in the first cylinder 11 and defines a space in the first cylinder 11, and a damping force adjuster 50 that is provided outside the second cylinder 12 and has a valve mechanism V (an example of a throttle portion) that throttles an oil flow path, and discharges oil that moves with the movement of the piston portion 30 toward the reservoir chamber R while passing through the valve mechanism V. The shock absorber 2 also includes a forming member 90 that forms a flow path through which the oil discharged from the opening 130 flows toward the damping force adjuster 50. The shock absorber 2 also includes a baffle plate 200 (an example of a restricting member) that is disposed within the reservoir chamber R and has a restricting portion 220 that restricts the movement of oil discharged from the damping force adjusting device 50 to the reservoir chamber R, and a sealing portion 230 that seals the gap between the opening 130 and the forming member 90.

[0051] According to the shock absorber 2 configured as above, the oil discharged from the damping force adjusting device 50 flows in the reservoir chamber R while being restricted by the restricting portion 220 of the baffle plate 200. For example, the first baffle surface 223 of the baffle plate 200 prevents the oil from moving toward the other side in the axial direction (upward in FIG. 1). In addition, since the space in the reservoir chamber R is partitioned by the restricting portion 220 of the baffle plate 200, rippling of the liquid surface caused by the oil discharged from the damping force adjusting device 50 is suppressed, and the generation of air bubbles in the oil is suppressed. As a result, according to the shock absorber 2, the delay in the generation of the damping force is suppressed, and a stable damping force can be generated. In addition, since the baffle plate 200 mitigates the sudden expansion of the flow path area of ​​the oil discharged from the damping force adjusting device 50, a sudden increase in the flow rate of the oil is suppressed, and the generation of vortexes is suppressed. As a result, the generation of cavitation due to the generation of vortexes is suppressed, and a stable damping force can be generated.

[0052] Moreover, the baffle plate 200 has a limiting portion 220 and a sealing portion 230 that seals the gap between the opening 130 and the forming member 90. Therefore, since the baffle plate 200 can integrally have the limiting portion 220 and the sealing portion 230, the number of parts can be reduced compared to a configuration in which a sealing member such as an O-ring that seals the gap between the opening 130 and the forming member 90 is provided as a separate member from the limiting portion 220. As a result, the number of steps required for assembling the shock absorber 2 is reduced, and productivity can be improved.

[0053] Here, the opening 130 has a protruding portion 132 that protrudes cylindrically from the outer circumferential surface 135 of the intermediate cylinder 13, the forming member 90 is fitted into the second inner side of the protruding portion 132, and the seal portion 230 of the baffle plate 200 is sealed by being sandwiched between the protruding portion 132 and the forming member 90. This prevents oil from flowing between the communication passage L and the reservoir chamber R through the gap between the opening 130 and the forming member 90. In addition, the seal portion 230 is sandwiched between the protruding portion 132 and the forming member 90, thereby preventing the movement of the baffle plate 200 relative to the intermediate cylinder 13.

[0054] Moreover, the baffle plate 200 has a base portion 210 that connects the limiting portion 220 and the sealing portion 230 and that fits along the outer circumferential surface 135 of the intermediate cylinder 13, and the limiting portion 220 and the sealing portion 230 protrude outward from the base portion 210. This makes it possible to increase the area that can receive the oil discharged from the damping force adjusting device 50, thereby making it possible to highly reliably suppress rippling of the oil on the liquid surface.

[0055] Furthermore, the seal portion 230 of the baffle plate 200 has an inner circumferential portion 232 (an example of a cylindrical portion) that is sandwiched between the protruding portion 132 of the intermediate cylinder 13 and the forming member 90, and the inner circumferential portion 232 has a protruding portion 234 that fits into a recessed portion 133 recessed from the inner circumferential surface of the protruding portion 132. This makes it possible to suppress the baffle plate 200 from rotating relative to the intermediate cylinder 13.

[0056] <Second embodiment> Fig. 6(a) is a diagram showing an example of a schematic configuration of a baffle plate 300 according to a second embodiment. Fig. 6(b) is a diagram showing an example of a cross section taken along line VIb-VIb of Fig. 6(a). The shock absorber 202 according to the second embodiment is different from the shock absorber 2 according to the first embodiment in that it has a baffle plate 300 corresponding to the baffle plate 200. The differences from the first embodiment will be described below. The same reference numerals are used for the same parts in the first and second embodiments, and detailed descriptions thereof will be omitted.

[0057] The baffle plate 300 differs from the baffle plate 200 according to the first embodiment in that the baffle plate 300 has a first connecting portion 310 and a second connecting portion 320. More specifically, baffle plate 300 has a plurality of first connection parts 310 that protrude outward from base 210 and connect first limiting part 221 and seal part 230, and a plurality of second connection parts 320 that connect a pair of second limiting parts 222 (an example of a center line direction part). The protruding height of first connection parts 310 and second connection parts 320 from base 210 is smaller than the protruding height of limiting part 220 from base 210, and first connection parts 310 and second connection parts 320 do not contact the inner circumferential surface of second cylinder 12 (see FIG. 2).

[0058] The multiple first connection parts 310 are provided at equal intervals around the periphery of the seal part 230. In the baffle plate 300 according to the second embodiment, three first connection parts 310 are provided, and each of the three first connection parts 310 is composed of one first connection part 310 extending in the axial direction and two first connection parts 310 extending in the circumferential direction. The plurality of second connection portions 320 are provided on one side of the seal portion 230, two of which are arranged in the axial direction and extend in the circumferential direction.

[0059] The baffle plate 300 configured as described above is more rigid than the baffle plate 200 and is therefore less likely to deform. For example, deformation of the inner surfaces of the base 210 (for example, both circumferential ends) toward each other is suppressed. As a result, the baffle plate 300 can be easily attached to the intermediate cylinder 13 (see FIG. 2).

[0060] <Third embodiment> Fig. 7(a) is a diagram showing an example of a schematic configuration of a baffle plate 400 according to a third embodiment. Fig. 7(b) is a diagram showing an example of a cross section taken along line VIIb-VIIb in Fig. 7(a). The shock absorber 302 according to the third embodiment is different from the shock absorber 2 according to the first embodiment in that it has a baffle plate 400 corresponding to the baffle plate 200. The differences from the first embodiment will be described below. The same reference numerals are used for the same parts in the first and third embodiments, and detailed descriptions thereof will be omitted.

[0061] The baffle plate 400 according to the third embodiment differs from the baffle plate 200 according to the first embodiment in that it has a flow straightening portion 410. More specifically, the baffle plate 400 has a plurality of (four in FIG. 7 ) flow straightening portions 410 that protrude outward from the base portion 210 and straighten the flow of oil between a pair of second restriction portions 222 (an example of center line direction portions) on one side of the seal portion 230. The flow straightening portions 410 are provided to extend in the axial direction. The protruding height of the flow straightening portions 410 from the base portion 210 is smaller than the protruding height of the second restriction portions 222 from the base portion 210, and the flow straightening portions 410 do not contact the inner circumferential surface of the second cylinder 12.

[0062] According to the baffle plate 400 configured as above, the flow direction of the oil discharged from the damping force adjusting device 50 is restricted by the flow straightening section 410, so a sudden increase in the oil flow rate is suppressed and the generation of vortexes is inhibited. As a result, the generation of cavitation due to the generation of vortexes is suppressed, so a stable damping force can be generated.

[0063] FIG. 8 is a diagram showing an example of a modified example of the baffle plate 400. As shown in FIG. The baffle plate 400 according to the modified example has a pair of second limiting portions 422 corresponding to the pair of second limiting portions 222. In the pair of second limiting portions 422, the other side portion is provided so as to extend in the axial direction like the pair of second limiting portions 222, but the one side portion is inclined in the axial direction so that the distance therebetween gradually increases toward one side. In other words, the second limiting portion 422 at the other side portion and the second limiting portion 422 at the one side portion are provided so as to form an obtuse angle.

[0064] The flow straightening portions 410 provided at both ends in the circumferential direction among the plurality of flow straightening portions 410 are provided so as to be parallel to the adjacent second restriction portions 422, and so as to form an obtuse angle between the flow straightening portion 410 at the other side portion and the flow straightening portion 410 at the one side portion. Moreover, among the plurality of flow straightening portions 410, the flow straightening portion 410 located on the left side of a line passing through the center of the seal portion 230 and parallel to the axial direction in FIG. 8 is provided so as to be parallel to the flow straightening portion 410 located on the left side. Moreover, among the plurality of flow straightening portions 410, the flow straightening portion 410 located on the right side of a line passing through the center of the seal portion 230 and parallel to the axial direction in FIG. 8 is provided so as to be parallel to the flow straightening portion 410 located on the right side.

[0065] According to the baffle plate 400 configured as above, the flow direction of the oil discharged from the damping force adjusting device 50 is restricted by the flow straightening section 410 and the flow passage area gradually increases, so that a sudden increase in the oil flow rate is suppressed and the generation of vortexes is inhibited. As a result, the generation of cavitation due to the generation of vortexes is suppressed, so that a more stable damping force can be generated.

[0066] <Fourth embodiment> FIG. 9 is a diagram showing an example of a schematic configuration of a shock absorber 402 according to the fourth embodiment. A shock absorber 402 according to the fourth embodiment differs from the shock absorber 2 according to the first embodiment in that it has an intermediate cylinder 413 corresponding to the intermediate cylinder 13, and a baffle plate 500 corresponding to the baffle plate 200. The following describes the differences from the first embodiment. The same reference numerals are used for the same parts in the first and fourth embodiments, and detailed descriptions thereof will be omitted.

[0067] The intermediate cylinder 413 according to the fourth embodiment is different from the intermediate cylinder 13 according to the first embodiment in a protruding portion 432 of an opening 430 that corresponds to the protruding portion 132 of the opening 130. The protruding portion 432 is different from the protruding portion 132 in that the shape of the outer circumferential surface of the protruding portion 432 when viewed from the outside is not circular. For example, as shown in FIG. 9, the outer circumferential surface of the protruding portion 432 can be a trapezoid. Note that the outer circumferential surface of the protruding portion 432 may have any other shape as long as it is non-circular.

[0068] The baffle plate 500 according to the fourth embodiment is different from the baffle plate 200 according to the first embodiment in that an outer periphery 531 of a seal portion 530 corresponding to the outer periphery 231 of the seal portion 230. The outer periphery 531 has the same shape as the outer periphery of the protruding portion 432 so that the outer periphery 531 can be disposed on the second outer side of the protruding portion 432 of the intermediate cylinder 413. For example, as shown in FIG. 9, the outer periphery 531 can be illustrated as being trapezoidal.

[0069] As described above, the inner surface of the protruding portion 432 of the intermediate cylinder 413 is circular and the outer surface is non-circular (e.g., trapezoidal) when viewed in the radial direction of the intermediate cylinder 413. The sealing portion 530 of the baffle plate 500 has an outer circumferential portion 531 (an example of a covering portion) that covers the outer surface of the protruding portion 432. According to the shock absorber 402 configured as described above, since there is only one orientation in which the baffle plate 500 can be attached to the intermediate cylinder 413, the baffle plate 500 is prevented from being attached to the intermediate cylinder 413 in an incorrect orientation.

[0070] In the above example, the outer peripheral surface of the protruding portion 432 of the intermediate cylinder 413 and the outer peripheral portion 531 of the sealing portion 530 of the baffle plate 500 are noncircular (e.g., trapezoidal), but are not particularly limited to this embodiment. For example, a convex portion protruding in a noncircular shape (e.g., trapezoidal) from the outer peripheral surface 135 may be provided around the protruding portion 132 on the outer peripheral surface 135 of the intermediate cylinder 13, and a concave portion recessed in a noncircular shape (e.g., trapezoidal) from the inner surface of the base 210 to the outside may be provided around the outer peripheral portion 231 of the base 210 of the baffle plate 200, and these convex portions and concave portions may be fitted together.

[0071] <Fifth embodiment> FIG. 10 is a diagram showing an example of a schematic configuration of a shock absorber 502 according to the fifth embodiment. A shock absorber 502 according to the fifth embodiment differs from the shock absorber 2 according to the first embodiment in that it has a forming member 590 corresponding to the forming member 90, and a baffle plate 600 corresponding to the baffle plate 200. The following describes the differences from the first embodiment. The same reference numerals are used for the same parts in the first and fifth embodiments, and detailed descriptions thereof will be omitted.

[0072] The forming member 590 according to the fifth embodiment differs from the forming member 90 according to the first embodiment in a cylindrical portion 591 corresponding to the cylindrical portion 91. The cylindrical portion 591 has a first cylindrical portion 593 provided on the first side and a second cylindrical portion 594 provided on the second side. The first cylindrical portion 593 and the second cylindrical portion 594 have the same outer diameter but different inner diameters. The inner diameter of the second cylindrical portion 594 is the same as the inner diameter of the protruding portion 132 of the opening 130 of the intermediate cylinder 13, and the inner diameter of the first cylindrical portion 593 is larger than the outer diameter of the protruding portion 132. In addition, a chamfer 595 is formed on the inner circumferential surface of the end portion on the first side of the first cylindrical portion 593.

[0073] The baffle plate 600 according to the fifth embodiment is different from the baffle plate 200 according to the first embodiment in that it has a seal portion 630 that corresponds to the seal portion 230. The seal portion 630 has a cylindrical outer peripheral portion 631 that is arranged on the second outer side of the outer peripheral surface of the protruding portion 132 of the intermediate cylinder 13, and does not have the inner peripheral portion 232 and the second side portion 233 that the baffle plate 200 according to the first embodiment has.

[0074] The forming member 590 is assembled to the intermediate cylinder 13 until the end face on the first side of the second cylindrical portion 594 abuts against the protruding portion 132 of the opening 130 of the intermediate cylinder 13. Then, the first cylindrical portion 593 is positioned on the second outer side of the protruding portion 132, and the outer periphery 631 of the seal portion 630 of the baffle plate 600 is sandwiched between the end of the first side of the first cylindrical portion 593 and the intermediate cylinder 13. In particular, the outer periphery 631 of the baffle plate 600 is crushed by the chamfer 595 of the first cylindrical portion 593, the outer periphery 135 of the intermediate cylinder 13, and the protruding portion 132.

[0075] As described above, the opening 130 of the intermediate cylinder 13 has a cylindrical protrusion 132 that protrudes from the outer peripheral surface 135 of the intermediate cylinder 13, the forming member 590 is fitted into the second outer side of the protrusion 132, and the sealing portion 630 of the baffle plate 600 is sealed by being sandwiched between the forming member 590 and the outer peripheral surface 135 of the intermediate cylinder 13 at the second outer side of the protrusion 132.

[0076] Even in the shock absorber 502 configured as described above, the oil coming out of the damping force adjusting device 50 flows within the reservoir chamber R while being restricted by the restricting portion 220 of the baffle plate 600, so that the occurrence of cavitation is suppressed and a stable damping force is generated. Moreover, the baffle plate 600 has the limiting portion 220 and the sealing portion 630 that seals the gap between the opening 130 and the forming member 590. Therefore, since the baffle plate 600 can integrally have the limiting portion 220 and the sealing portion 630, the number of parts can be reduced compared to a configuration in which a sealing member such as an O-ring that seals the gap between the opening 130 and the forming member 590 is provided as a separate member from the limiting portion 220. As a result, the number of steps required for assembling the shock absorber 502 is reduced, and productivity can be improved. [Explanation of symbols]

[0077] 1...suspension device, 2, 202, 302, 402, 502...shock absorber, 3...coil spring (one example of a spring), 10...cylinder portion, 11...first cylinder, 12...second cylinder, 13...intermediate cylinder, 20...rod, 30...piston portion, 50...damping force adjuster, 90, 590...forming member, 130...opening, 131...through hole, 132...projection, 133...recess, 135...outer peripheral surface, 200...baffle plate (an example of a restricting member), 210...base, 220...restricting portion, 221...first restricting portion, 222...second restricting portion (an example of a center line direction portion), 230, 630...sealing portion, 234...projecting portion, 310...first connecting portion, 320...second connecting portion, 410...rectifying portion, 531...outer peripheral portion, R...reservoir chamber (an example of a liquid reservoir portion), V...valve mechanism (an example of a throttle portion)

Claims

1. a first cylinder containing a liquid; A second cylinder disposed radially outward of the first cylinder; an intermediate cylinder disposed between the first cylinder and the second cylinder, forming a liquid reservoir in which liquid is retained in a gap between the intermediate cylinder and the second cylinder, and having an opening for discharging liquid from a gap between the intermediate cylinder and the first cylinder; a piston portion disposed in a first cylinder and defining a space within the first cylinder; a damping force adjusting device that is provided outside the second cylinder and has a throttle portion that throttles a flow path of the liquid, and that discharges the liquid that moves with the movement of the piston portion toward the liquid reservoir portion while passing through the throttle portion; a forming member that forms a flow path through which the liquid discharged from the opening flows toward the damping force adjusting device; a limiting member that is disposed within the liquid reservoir and has a limiting portion that limits the movement of the liquid discharged from the damping force adjusting device to the liquid reservoir, and a sealing portion that seals a gap between the opening and the forming member; A shock absorber comprising:

2. The opening has a cylindrical protrusion protruding from an outer circumferential surface of the intermediate cylinder, The forming member is fitted inside the protruding portion, The seal portion of the restricting member is sandwiched between the protrusion and the forming member to provide a seal. The shock absorber according to claim 1 .

3. The restricting member has a base portion that connects the restricting portion and the sealing portion and that is aligned with an outer peripheral surface of the intermediate cylinder, and the restricting portion and the sealing portion protrude outward from the base portion. The shock absorber according to claim 2.

4. The restricting member has a connecting portion that protrudes outward from the base portion and connects the restricting portion and the sealing portion. The shock absorber according to claim 3.

5. the limiting portion has a pair of centerline direction portions extending from both circumferential end portions of the base portion to one side in a centerline direction of the intermediate cylinder, The limiting member has a connecting portion that protrudes outward from the base portion and connects the pair of center line direction portions. The shock absorber according to claim 3.

6. the restricting member has a plurality of straightening portions that protrude outward from the base portion and extend in the center line direction on one side of the center of the seal portion in the center line direction of the intermediate cylinder to straighten the flow of liquid, The shock absorber according to claim 3.

7. the seal portion has a cylindrical portion sandwiched between the protrusion and the forming member, The cylindrical portion has a protrusion that fits into a recess recessed from an inner circumferential surface of the protrusion. The shock absorber according to claim 2.

8. When viewed in the radial direction of the intermediate cylinder, the protrusion has an inner surface that is circular and an outer surface that is non-circular. The sealing portion has a covering portion that covers the outer surface of the protrusion. The shock absorber according to claim 2.

9. The opening has a cylindrical protrusion protruding from an outer circumferential surface of the intermediate cylinder, The forming member is fitted to the outside of the protruding portion, The seal portion of the limiting member is sandwiched between the forming member and the outer circumferential surface of the intermediate cylinder on the outside of the protrusion to provide a seal. The shock absorber according to claim 1 .

10. A shock absorber according to any one of claims 1 to 9; A spring disposed outside the shock absorber; A suspension device comprising:

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