JP7253513B2 - buffer - Google Patents

Description

TECHNICAL FIELD The present disclosure relates to shock absorbers that reduce vibrations in vehicles, such as automobiles.

Patent Literature 1 describes a shock absorber in which a piston is provided with a main flow passage and a choke passage in parallel with the main flow passage. The choke passage is formed in a threaded part (bolt) attached to the piston. The choke passage is formed, for example, as a spiral communication passage.

Japanese Patent Application Laid-Open No. 2017-57878 (Patent No. 6487816)

The choke passage of the damper preferably has a short axial length and a long passage length. In the case of the prior art, since a helical communicating passage is formed as a long, thin choke passage in the threaded part, moldability and productivity are poor, and there is a possibility that the manufacturing cost will increase.

An object of an embodiment of the present invention is to provide a shock absorber in which a communication passage (first communication passage) having a long passage length and a short axial length can be formed at low cost, and manufacturing costs can be reduced.

A shock absorber according to one embodiment of the present invention includes a cylinder in which a working fluid is enclosed, a piston that divides the inside of the cylinder into one side chamber and the other side chamber, and a piston rod that is connected to the piston and extends to the outside of the cylinder. a flow path through which the working fluid flows due to movement of the piston; and a flow path having a plurality of plate-shaped discs which are provided in the flow path and are stacked to form a first communication path and which are not always flexurally deformed. and a forming member, the disc having a radially or circumferentially extending through or bottomed groove.

Further, the shock absorber of one embodiment of the present invention includes a cylinder in which a working fluid is sealed, a piston that divides the inside of the cylinder into one side chamber and the other side chamber, and a piston that is connected to the piston and extends to the outside of the cylinder. a piston rod, a reservoir for compensating for entry and exit of the piston rod, second and third communication passages for communicating the one side chamber and the other side chamber by movement of the piston, and the second and third communication passages. First and second valves respectively provided in the passages, and provided between the one side chamber and the other side chamber, between the one side chamber and the reservoir, and/or between the other side chamber and the reservoir. and a flow path forming member having a plurality of plate-like discs laminated to form the first communication path, wherein the plurality of discs are spiral-shaped through-holes extending in the circumferential direction to a position where the starting point exceeds the end point. It includes at least one disc having grooves or bottomed grooves.

Further, the shock absorber of one embodiment of the present invention includes a cylinder in which a working fluid is sealed, a piston that divides the inside of the cylinder into one side chamber and the other side chamber, and a piston that is connected to the piston and extends to the outside of the cylinder. a piston rod, a flow path in which the working fluid flows due to movement of the piston, a damping force adjustment valve whose opening and closing operation is adjusted by a solenoid, and a through groove provided in the flow path and extending in the circumferential direction. 1 disc, and a closing portion that closes the through groove so that the working fluid supplied to one side of the through groove flows to the other side of the through groove that is different from the one side, and the other side of the through groove. a passage forming member having a second disk laminated on the first disk and having a through hole or a through groove provided at a position corresponding to the first disk.

ADVANTAGE OF THE INVENTION According to one embodiment of the present invention, a communication passage (first communication passage) having a long passage length and a short axial length can be formed at low cost, and manufacturing costs can be reduced.

1 is a longitudinal sectional view showing a shock absorber according to a first embodiment; FIG. It is an enlarged cross section of the (II) part in FIG. FIG. 3 is a partially sectional perspective view showing the passage forming unit (fixing member, flow passage forming member, storage member) in FIG. 2 ; FIG. 3 is an exploded perspective view of the passage forming unit in FIG. 2; FIG. 4 is a characteristic diagram showing the relationship between piston speed and damping force; FIG. 3 is a cross-sectional view at the same position as FIG. 2 showing a passage forming unit according to a second embodiment together with a piston, a piston rod, and the like; FIG. 7 is a partially cross-sectional perspective view showing the passage forming unit in FIG. 6 ; FIG. 7 is an exploded perspective view of the passage forming unit in FIG. 6; FIG. 3 is a cross-sectional view at the same position as in FIG. 2 showing a flow path forming member according to a third embodiment together with a piston, a piston rod, and the like; FIG. 9 is a half longitudinal sectional view cut at a different position in the circumferential direction of the piston. FIG. 4 is a plan view showing each disk that constitutes the flow path forming member; FIG. 11 is a cross-sectional view of the same position as FIG. 2 showing a flow path forming member according to a fourth embodiment together with a piston, a piston rod, and the like; FIG. 4 is a plan view showing each disk that constitutes the flow path forming member; FIG. 11 is a cross-sectional view of the same position as FIG. 2 showing a flow path forming member according to a fifth embodiment together with a piston, a piston rod, and the like; FIG. 4 is a plan view showing disks constituting spacers and flow path forming members, respectively; FIG. 11 is a cross-sectional view of the same position as FIG. 2 showing a flow path forming member according to a sixth embodiment together with a piston, a piston rod, and the like; FIG. 4 is a plan view showing each disk that constitutes the flow path forming member; FIG. 11 is a cross-sectional view of the same position as FIG. 2 showing a flow path forming member according to a seventh embodiment together with a piston, a piston rod, a frequency sensitive portion, and the like; FIG. 19 is an exploded perspective view showing a fixing member and a flow path forming member in FIG. 18; FIG. 11 is a cross-sectional view of the same position as FIG. 2 showing a flow path forming member, a piston, a piston rod, a frequency sensitive part, etc. according to an eighth embodiment; It is a longitudinal cross-sectional view showing a shock absorber according to a ninth embodiment. 22 is a partially enlarged cross-sectional view showing the damping force adjusting device and the like in FIG. 21; FIG. FIG. 20 is a vertical cross-sectional view showing a shock absorber according to a tenth embodiment; 24 is a partially enlarged cross-sectional view showing an enlarged damping force adjusting device in FIG. 23; FIG. FIG. 20 is a vertical cross-sectional view showing a shock absorber according to an eleventh embodiment; 26 is a partially enlarged cross-sectional view showing an enlarged damping force adjusting device in FIG. 25; FIG. FIG. 4 is a plan view showing each disk that constitutes the flow path forming member; FIG. 11 is a plan view showing a modification of the disk;

Hereinafter, a case where the shock absorber according to the embodiment is applied to a hydraulic shock absorber mounted on a vehicle (for example, a four-wheeled vehicle) will be described as an example with reference to the accompanying drawings. It should be noted that the attached drawings are drawings that have been drawn with such accuracy as conforming to design drawings.

1 to 4 show a first embodiment. In FIG. 1, a damper 1 is, for example, a hydraulic damper for vehicles such as automobiles. The shock absorber 1 constitutes a suspension system for a vehicle together with a suspension spring (not shown) made of, for example, a coil spring. In the following description, one axial end side of the shock absorber 1 is referred to as the "lower end" side, and the other axial end side is referred to as the "upper end" side. The "upper end" side may be the "upper end" side, and the other end side in the axial direction may be the "lower end" side.

The shock absorber 1 includes an outer cylinder 2 , an inner cylinder 4 , a piston 6 , a piston rod 11 and a passage forming member 22 . The outer cylinder 2 is formed in the shape of a cylinder with a bottom, and constitutes the outer shell of the shock absorber 1 . The outer cylinder 2 is closed by welding a bottom cap 3 at its lower end, which is one end, and is open at its upper end, which is the other end. The upper end portion of the outer cylinder 2 is provided with a plurality of crimped portions 2A bent radially inward by, for example, crimping. An upper end opening of the outer cylinder 2 is closed by a rod guide 9 and a rod seal 10 .

An inner cylinder 4 as a cylinder is provided coaxially within the outer cylinder 2 . The inner cylinder 4 and the outer cylinder 2 constitute a double cylinder type cylinder device. In the inner cylinder 4 and the outer cylinder 2, hydraulic fluid (hydraulic oil) as a working fluid (hydraulic fluid) is enclosed. The oil liquid, which is the hydraulic fluid, is not limited to oil, and may be, for example, water mixed with an additive. The inner cylinder 4 has its lower end fitted to the outer periphery of the bottom valve 5 and is closed by a rod guide 9 at its upper end.

The inner cylinder 4 forms (defines) an annular reservoir chamber A between itself and the outer cylinder 2 . Gas is enclosed in the reservoir chamber A together with oil liquid, which is a working liquid. This gas may be, for example, air at atmospheric pressure, or compressed nitrogen gas. Reservoir chamber A as a reservoir compensates for the entry and exit of piston rod 11 . The bottom valve 5 is positioned on the lower end side of the inner cylinder 4 and provided between the bottom cap 3 and the inner cylinder 4 .

The piston 6 is slidably inserted (inserted) into the inner cylinder 4 . The piston 6 divides (defines) the inside of the inner cylinder 4 into two chambers (that is, a bottom side oil chamber B as one side chamber and a rod side oil chamber C as the other side chamber). The piston 6 is formed with a plurality of oil passages 6A and 6B that allow the bottom side oil chamber B and the rod side oil chamber C to communicate with each other. The oil passages 6A and 6B prevent the hydraulic fluid (oil fluid) from flowing from one chamber to the other of the oil chambers B and C in the inner cylinder 4 (cylinder) due to the movement of the piston 6. It constitutes a permissive passage. That is, the oil passage 6A serving as the second communication passage and the oil passage 6B serving as the third communication passage are arranged such that, by movement of the piston 6, the bottom side oil chamber B serving as one side chamber and the rod side oil chamber C serving as the other side chamber are connected. communicate. The oil passages 6A and 6B are main flow passages (second flow passages) in which the movement of the piston 6 causes the working fluid (oil liquid) to flow. A piston ring 6</b>C that slides on the inner peripheral surface of the inner cylinder 4 is provided on the outer peripheral side of the piston 6 .

A disk valve 7 that constitutes a contraction side (compression side) damping valve is provided on the upper side surface of the piston 6 . The compression side disk valve 7 (hereinafter referred to as the compression side disk valve 7) is configured such that when the piston 6 is slidably displaced downward along the inner cylinder 4 in the contraction stroke of the piston rod 11, the bottom side oil chamber A resistance force is applied to the oil flowing through the oil passage 6A from B toward the rod-side oil chamber C. As a result, a predetermined damping force is generated in the contraction stroke of the piston rod 11 . That is, the pressure-side disk valve 7 controls the flow of the working fluid (oil liquid) caused by the sliding of the piston 6 inside the inner cylinder 4 to generate damping force. The pressure side disc valve 7 corresponds to a first valve provided in the oil passage 6A as the second communication passage.

A disc valve 8 that constitutes a damping valve on the extension side (elongation side) is provided on the lower side surface of the piston 6 . The disk valve 8 on the extension side (hereinafter referred to as the disk valve 8 on the extension side) displaces the rod-side oil when the piston 6 slides upward along the inner cylinder 4 in the extension stroke (elongation stroke) of the piston rod 11 . A resistance force is applied to the oil flowing through the oil passage 6B from the chamber C toward the bottom side oil chamber B. As a result, a predetermined damping force is generated during the extension stroke of the piston rod 11 . That is, the extension side disk valve 8 controls the flow of the working fluid (oil liquid) caused by the sliding of the piston 6 inside the inner cylinder 4 to generate a damping force. The growth side disk valve 8 corresponds to the second valve provided in the oil passage 6B as the third communication passage.

Upper end sides (open end sides) of the outer cylinder 2 and the inner cylinder 4 are closed by a rod guide 9 and a rod seal 10 . The rod guide 9 is a guide member that slidably guides the axial displacement of the piston rod 11 . The rod guide 9 is formed as a cylindrical body having a predetermined shape by subjecting a metal material, a hard resin material, or the like to molding, cutting, or the like. It is fitted and provided.

The rod seal 10 is provided between the upper surface of the rod guide 9 and the caulked portion 2A of the outer cylinder 2. As shown in FIG. The rod seal 10 has a metallic annular plate 10A as a metal core. An elastic sealing material such as rubber is integrally formed with the annular plate 10A by, for example, baking. The rod seal 10 liquid-tightly and air-tightly seals between the outer cylinder 2 and the piston rod 11 by having its inner circumference slidably contact the outer circumference of the piston rod 11 .

The bottom end of the piston rod 11 is inserted into the inner cylinder 4 , and the top end of the piston rod 11 projects out of the inner cylinder 4 through a rod guide 9 . That is, the piston rod 11 is connected to the piston 6 and extends outside the inner cylinder 4 . Attached to the lower end of the piston rod 11 are a piston 6, a pressure-side disk valve 7, an expansion-side disk valve 8, and a passage forming unit 20, which will be described later. For this reason, the lower end of the piston rod 11 is provided with a small-diameter portion 11A having a smaller diameter than the other portions, and the fixing member 21 of the passage forming unit 20 is screwed to the end of the small-diameter portion 11A. A male threaded portion 11B is provided.

By the way, Patent Document 1 describes a shock absorber in which a main flow passage and a choke passage parallel to the main flow passage are provided in a piston. According to this prior art, a helical choke passage is formed in a threaded part (bolt) attached to the piston. Here, in order to obtain desired damping force characteristics, it is necessary to adjust the cross-sectional area and length (passage length) of the choke passage according to the damping force characteristics. In the prior art, when manufacturing shock absorbers with different choke characteristics, dedicated parts (screw parts) are required for each characteristic. As a result, the number of types of parts (threaded parts) in which choke passages are formed increases, which may increase management costs. In order to avoid this, for example, it is conceivable to provide a dedicated processing machine in the assembly line. However, in this case, there is a possibility that the equipment investment will increase and the manufacturing cost will increase.

In other words, the part (threaded part) in which the choke passage is formed requires a special assembly process, unlike the component parts of conventional shock absorbers. There is Moreover, in the case of the conventional technology, since the production quantity of the same part is limited, even if the quantity increases, it is difficult to reduce the manufacturing cost of the part itself. Moreover, in the case of the prior art, the intention is to use a 3D printer to form the parts (threaded parts) in which the choke passages are formed. In addition, the part (threaded part) in which the choke passage is formed must be placed between the cylinder side surface of the piston and the outer peripheral surface of the piston rod. length) becomes difficult to lengthen.

Therefore, in the embodiment, the communication path is formed by stacking a plurality of discs including discs having through grooves or bottomed grooves. As a result, a communication passage having a long passage length can be formed with a short axial length. In addition, the length of the communication path (passage length) can be adjusted as desired, and the rise responsiveness of the damping force can be enhanced. That is, when adjusting the rise characteristics of the damping force at a very low speed of the buffer (damper), if the fixed orifice (constant orifice) is used, the damping coefficient may be small and the damping force may be insufficient. There is a possibility that the damping coefficient is high and the ride comfort is reduced. In contrast, in the embodiment, the path length can be easily adjusted by selecting (combination, number of) discs. Therefore, by adjusting the passage length as desired, it is possible to improve the rise characteristics of the damping force when the piston speed is very low. As a result, highly responsive damping force characteristics can be obtained.

That is, in the embodiment, one or a plurality of discs (disc plates) having spiral through grooves (slits) or bottomed grooves (concave grooves) on the same surface are used as communication passages (throttle passages) having throttles. It is composed by stacking. Therefore, the length (passage length) of the communication passage (throttle passage) can be adjusted by the number of discs. Also, the outer diameter of the disk can be increased. Therefore, a large path length (choke length) can be obtained with a single disc. Moreover, by stacking discs of the same shape, it is possible to set many damping force characteristics (choke characteristics) while suppressing an increase in the number of types of parts. As a result, variations in damping force characteristics can be easily accommodated, and manufacturing costs can be reduced.

The communication path (first communication path) according to the first embodiment will be described in detail below.

As described above, the piston 6 is provided with the oil passage 6A serving as the second communication passage and the oil passage 6B serving as the third communication passage. The oil passages 6A and 6B are main flow passages that communicate between the bottom-side oil chamber B, which is one side chamber, and the rod-side oil chamber C, which is the other side chamber, via the compression-side disk valve 7 or the expansion-side disk valve 8. (main passage). That is, the oil passages 6A and 6B are flow passages (second flow passages) in which the movement of the piston 6 causes the working fluid (oil liquid) to flow.

In the embodiment, the shock absorber 1 includes a sub-passage 15 communicating between the bottom-side oil chamber B and the rod-side oil chamber C in parallel with the oil passages 6A and 6B. That is, the sub-passage 15 is provided in parallel with the oil passages 6A and 6B, and is a sub-passage that bypasses the oil passages 6A and 6B (compression-side disc valve 7 and expansion-side disc valve 8). Similarly to the main passages (oil passages 6A and 6B), the sub passage 15 is also a passage (first passage) through which the movement of the piston 6 causes the working fluid (oil liquid) to flow. The sub-passage 15 includes a rod-side passage 16 , an intermediate passage 17 , a throttle passage 18 as a first communication passage (communication passage), and an opening passage 19 . The throttle passage 18 is formed by a passage forming member 22 (disks 23, 24).

The rod-side passage 16 is composed of a vertical hole 11C and a horizontal hole 11D communicating with the vertical hole 11C. The vertical hole 11</b>C extends in the axial direction of the piston rod 11 and opens to the lower end surface of the piston rod 11 . The lateral hole 11</b>D is provided above the small diameter portion 11</b>A of the piston rod 11 (in other words, above the compression side disk valve 7 ) and extends in the radial direction of the piston rod 11 . The rod-side passage 16 is connected to the throttle passage 18 via the intermediate passage 17 .

A passage forming unit 20 is attached to the lower end of the piston rod 11 to form the throttle passage 18 . As shown in FIG. 4, the passage forming unit 20 includes a fixing member 21, a flow passage forming member 22, and a storage member 25. As shown in FIG. As shown in FIG. 3, the passage forming unit 20 has the passage forming member 22 (discs 23 and 24) disposed on the bottom portion 25B of the housing member 25, and the fixing member 21 is screwed to the housing member 25. can be assembled together. That is, the passage forming unit 20 can be configured as an assembly, and the previously assembled passage forming unit 20 can be attached to the male screw portion 11B of the piston rod 11 .

The fixing member 21 is a nut member for attaching the passage forming member 22 (disks 23 and 24) together with the housing member 25 to the piston rod 11. As shown in FIG. The fixing member 21 is formed in a stepped cylindrical shape, and includes an inner cylindrical portion 21A positioned on the inner diameter side and an outer cylindrical portion 21B positioned on the outer side. A female threaded portion 21C that is screwed onto the male threaded portion 11B of the piston rod 11 is provided on the inner peripheral side of the inner cylindrical portion 21A. A male threaded portion 21D that screws together with a female threaded portion 25C of the storage member 25 is provided on the outer peripheral side of the outer cylindrical portion 21B. A large-diameter hole portion 21E having a large inner diameter is provided on the inner diameter side of the fixing member 21, the large-diameter hole portion 21E being positioned closer to the flow path forming member 22 (disks 23, 24) than the female screw portion 21C. An intermediate passage 17 connecting the rod-side passage 16 and the throttle passage 18 is formed in the large-diameter hole portion 21E.

The flow path forming member 22 is provided in the sub-passage 15 . That is, the flow path forming member 22 is provided between the bottom side oil chamber B, which is one side chamber, and the rod side oil chamber C, which is the other side chamber. The flow path forming member 22 has a plurality of plate-like discs 23 and 24 stacked vertically (axially) to form a throttle passage 18 serving as a first communication passage. Specifically, the flow path forming member 22 is composed of two disk-shaped discs 23 and 24 . In this case, the channel forming member 22 has an introduction disc 23 and a passage disc 24 . The discs 23 and 24 are not flexurally deformed at all times. That is, the discs 23 and 24 of the flow path forming member 22 are different from disc valves such as open/close valves that are flexurally deformed as the oil flows. The flow path forming member 22 , that is, the introduction disk 23 and the passage disk 24 are sandwiched between the lower end of the fixed member 21 and the bottom portion 25B of the storage member 25 .

The lead-in disc 23 has a radially extending through groove 23B. Specifically, the introduction disk 23 closes a central hole 23A serving as a through hole provided in the center, a slit-shaped through groove 23B extending radially from the central hole 23A, and a through groove 24A of the passage disk 24. and a closing portion 23C. On the other hand, the passage disk 24 has a through groove 24A extending in the circumferential direction. Specifically, the passage disk 24 has a slit-like through hole extending spirally in the circumferential direction from a position corresponding to the end of the through groove 23B of the introduction disk 23 (that is, the end opposite to the center hole 23A). It has a groove 24A.

The through groove 24A of the passage disk 24 is formed in a spiral shape that gradually expands or contracts while extending in the circumferential direction. That is, the through-groove 24A is formed in a spiral shape extending around the same plane (continuously turning while changing the distance from the center). In this case, as shown in FIG. 4, the through groove 24A extends from the radially innermost inner diameter side end portion 24B of the passage disk 24 to the radially outermost outer diameter side end portion 24C. That is, it extends in the circumferential direction (clockwise) by 720°. The introduction disc 23 and the passage disc 24 are pressed by the fixing member 21 against the bottom portion 25B of the storage member 25 serving as a case. In this state, the through groove 24A of the passage disk 24 is axially closed by the closing portion 23C of the introduction disk 23 and the bottom portion 25B of the storage member 25. As shown in FIG. Thereby, the through groove 24A of the passage disc 24 forms the throttle passage 18. As shown in FIG.

Here, as indicated by arrows in FIG. It is an introduction passage that leads to the inner diameter side end portion 24B that becomes the one side). The blocking portion 23C of the introduction disk 23 is configured so that oil supplied to the inner diameter side end portion 24B of the through groove 24A of the passage disk 24 is located downstream of the through groove 24A (the other side different from the one side). The through groove 24A of the passage disk 24 is blocked so that it flows in the circumferential direction to the radial end portion 24C. The bottom portion 25B of the storage member 25 is also formed on the passage disk 24 so that the oil supplied to the inner diameter side end portion 24B of the through groove 24A of the passage disk 24 flows in the circumferential direction to the outer diameter side end portion 24C of the through groove 24A. It closes the through groove 24A. That is, the closing portion 23C of the introduction disk 23 and the bottom portion 25B of the storage member 25 close the through groove 24A of the passage disk 24 from both sides in the penetrating direction (vertical direction). As a result, the oil in the through groove 24A can flow clockwise or counterclockwise in the through groove 24A as the piston 6 moves.

Positioning projections 23D and 24D are provided on the outer peripheral surface of the introduction disk 23 and the outer peripheral surface of the passage disk 24, projecting radially outward from other portions. The positioning protrusion 23D of the introduction disk 23 is provided, for example, at a position corresponding to the through groove 23B extending in the radial direction (at a position where the phases in the circumferential direction match). The positioning projections 24D of the passage disk 24 are provided at positions corresponding to, for example, the ends of the through grooves 24A (the inner diameter side end 24B and the outer diameter side end 24C) (positions where phases in the circumferential direction match). there is The positioning protrusions 23D and 24D are engaged with a longitudinal groove-shaped positioning recess 25D provided on the inner peripheral surface of the cylindrical portion 25A of the storage member 25. As shown in FIG. As a result, the introduction disk 23 and the passage disk 24 are positioned in the circumferential direction and prevented from being displaced (rotated) in the circumferential direction.

The storage member 25 is formed as a bottomed cylindrical case. The storage member 25 includes a cylindrical tubular portion 25A and a bottom portion 25B that closes an opening on one end side (lower end side) of the tubular portion 25A. A female threaded portion 25C with which the male threaded portion 21D of the fixing member 21 is screwed is provided inside the tubular portion 25A. A positioning recess 25D that is recessed radially outward from other portions is formed inside the cylindrical portion 25A. The positioning recess 25D is formed in the shape of a longitudinal groove extending in the axial direction of the tubular portion 25A. The positioning recessed portion 25D is provided, for example, at a position corresponding to the through hole 25E formed in the bottom portion 25B (at a position where the phases in the circumferential direction match). The positioning protrusions 23D of the passage disc 24 and the positioning protrusions 23D of the introduction disc 23 are engaged with the positioning recesses 25D. A bottom portion 25B of the storage member 25 is provided with a through hole 25E at a position corresponding to the outer diameter side end portion 24C of the through groove 24A of the passage disk 24 . The through hole 25E serves as an open passage 19 that opens to the bottom side oil chamber B. As shown in FIG. That is, the through hole 25E connects the throttle passage 18 and the bottom side oil chamber B. As shown in FIG.

The passage disc 24 and the introduction disc 23 are accommodated in the cylindrical portion 25A of the accommodation member 25. As shown in FIG. In this state, the fixing member 21 is coupled and fixed inside the cylindrical portion 25A of the storage member 25 by screwing. As a result, the passage disk 24 and the introduction disk 23 are sandwiched between the bottom portion 25B of the housing member 25 and the end surface of the fixing member 21. As shown in FIG. The passage forming unit 20 including the storage member 25 , the passage forming member 22 (disks 23 and 24 ), and the fixing member 21 can be assembled before being assembled to the piston rod 11 . The passage forming unit 20 is attached to the piston rod 11 by screwing the female threaded portion 21C of the fixing member 21 into the male threaded portion 11B of the piston rod 11 .

In the extension stroke of the piston rod 11, oil from the rod-side oil chamber C flows into the rod-side passage 16, the large-diameter hole portion 21E of the fixed member 21, the center hole 23A and the through groove 23B of the introduction disc 23, and the passage disc. The oil flows through the inner diameter side end portion 24B of the through groove 24A of No. 24, the spiral through groove 24A, the outer diameter side end portion 24C of the through groove 24A, and the through hole 25E of the storage member 25 to the bottom side oil chamber B. On the other hand, in the contraction stroke of the piston rod 11, the oil from the bottom side oil chamber B flows through the through hole 25E of the storage member 25, the outer diameter side end 24C of the through groove 24A of the passage disk 24, and the spiral through hole. Through the groove 24A, the rod side oil chamber C passes through the inner diameter side end portion 24B of the through groove 24A, the through groove 23B and the center hole 23A of the introduction disk 23, the large diameter hole portion 21E of the fixing member 21, and the rod side passage 16. flow to

In the first embodiment, the passage forming member 22 is provided inside the storage member 25 , and the storage member 25 is connected to the piston rod 11 via the fixing member 21 . Thereby, the flow path forming member 22 is provided in the bottom side oil chamber B which is one side chamber of the piston 6 . The passage forming member 22 includes a passage disk 24 having a spiral through groove 24A extending circumferentially from the starting point to the end point (that is, extending over 360°). That is, the plurality of discs 23 and 24 of the flow path forming member 22 are configured including at least the passage disc 24 . In addition, the through groove 24A extending in the circumferential direction may extend in the circumferential direction on the same plane, and may exceed 360°, or may be within 360° (for example, 90°, 180°, etc.). good. The circumferential length (passage length) of the through groove 24A can be adjusted so as to obtain desired damping force characteristics.

Passage disc 24 corresponds to a first disc having a circumferentially extending through groove 24A. The lead-in disc 23 corresponds to the second disc stacked on the first disc. Here, when the working fluid flows in the direction opposite to the arrow shown in FIG. Consider the case of a reduction stroke in which is on the downstream side (other side). In this case, the introduction disk 23 is arranged such that the working fluid supplied to the through groove 24A of the passage disk 24 (outer diameter side end 24C) is at a position different from the one side (inner diameter side end 24B). and a through groove 23B provided at a position corresponding to the other side (inner diameter side end portion 24B) of the through groove 24A.

The shock absorber 1 according to the first embodiment has the configuration as described above, and the operation thereof will be described next.

The shock absorber 1 has, for example, the tip side (upper end side) of the piston rod 11 attached to the vehicle body side of the vehicle (automobile), and the bottom cap 3 side, which is the base end side (lower end side) of the outer cylinder 2, is attached to the wheel side of the vehicle. (axle side). As a result, when vibration occurs during running of the vehicle, the piston rod 11 is extended and contracted while the disk valves 7 and 8 of the piston 6 generate a damping force, thereby damping the vibration at this time.

That is, when the piston rod 11 is in the contraction stroke, the pressure inside the bottom side oil chamber B is higher than that in the rod side oil chamber C. Hydraulic fluid (pressure oil) in the bottom side oil chamber B flows into the rod side oil chamber C through the throttle passage 18 of the sub passage 15 provided in parallel with the oil passage 6A of the piston 6, Generate damping force. Further, the oil in the bottom side oil chamber B flows through the oil passage 6A of the piston 6 and the compression side disk valve 7 into the rod side oil chamber C to generate damping force. At this time, an amount of oil corresponding to the volume of the piston rod 11 entering the inner cylinder 4 flows into the reservoir chamber A from the bottom side oil chamber B through the bottom valve 5 . As a result, the gas sealed inside is compressed in the reservoir chamber A, and the volume of the piston rod 11 is absorbed.

On the other hand, when the piston rod 11 is in the extension stroke, the pressure inside the rod-side oil chamber C is higher than that in the bottom-side oil chamber B. The hydraulic fluid (pressure oil) in the rod-side oil chamber C flows into the bottom-side oil chamber B through the throttle passage 18 of the sub-passage 15 provided in parallel with the oil passage 6B of the piston 6. A damping force is generated. Further, the oil in the rod-side oil chamber C flows through the oil passage 6B of the piston 6 and the extension-side disk valve 8 into the bottom-side oil chamber B, generating a damping force. At this time, an amount of oil equivalent to the advance volume (retraction volume) of the piston rod 11 advanced (retracted) from the inner cylinder 4 flows from the reservoir chamber A into the bottom side oil chamber B via the bottom valve 5. flow into

FIG. 5 shows damping force characteristics of a damper (buffer) at a very low speed. In FIG. 5, a solid line 27 indicates damping force characteristics of the shock absorber 1 of the embodiment having the throttle passage 18 by the flow path forming member 22 (disks 23, 24). A dashed line 28 indicates the damping force characteristic of a comparative damper without a throttle passage 18 (with a normal constant orifice). In the embodiment, the Reynolds number at very low speed can be reduced and the friction loss of the flow path can be increased by increasing the length of the flow path as compared with the comparative example (ordinary constant orifice). This makes it possible to increase the rise of the damping force at very low speeds compared to the comparative example (ordinary constant orifice). As a result, it is possible to increase the damping force rise response and improve the steering stability.

As described above, in the first embodiment, the flow path forming member 22 is formed by laminating the introduction disk 23 having the through groove 23B extending in the radial direction and the passage disk 24 having the through groove 24A extending in the circumferential direction. It is composed of That is, the flow path forming member 22 is constructed by stacking a plurality of discs 23, 24 including a passage disc 24 having a spiral through groove 24A extending in the circumferential direction to a position where the starting point exceeds the end point. In other words, the flow path forming member 22 includes a passage disk 24 as a first disk having a through groove 24A extending in the circumferential direction, and an introduction disk 23 as a second disk having a blocking portion 23C and a through groove 23B. have.

Therefore, it is possible to form the throttle passage 18 as a first communication passage having a long passage length and a short axial length with a simple structure such as stacking the discs 23, 24 having the through grooves 24A, 23B. As a result, the throttle passage 18 having a long passage length and a short axial length can be formed at low cost, and the manufacturing cost of the shock absorber 1 can be reduced. That is, since the choke passage 18 is composed of the discs 23 and 24, the manufacturing cost can be reduced. In this case, the parts forming the throttle passage 18 can be made similar to the conventional parts. For this reason, the assembly process can utilize conventional construction methods and conventional assembly lines. That is, no special process is required, and an increase in manufacturing cost can be minimized.

Moreover, since the outer diameters of the discs 23 and 24 can be made as large as the outer diameter of the piston 6, the length of the throttle passage 18 (passage length) can be increased. By adjusting the circumferential length (passage length) of the through groove 24A of the passage disk 24, desired damping force characteristics can be obtained. Furthermore, the number of passage discs 24 can be increased as in a second embodiment to be described later. That is, by adjusting the number of passage discs 24, the length of the throttle passage 18 (passage length) can be adjusted (changed). Therefore, it is possible to easily set the damping force characteristic as desired (for example, set the rising characteristic of the damping force as desired), and from this point of view also, the manufacturing cost can be reduced. That is, by using the discs 23 and 24 having a large outer diameter, it is possible to suppress an increase in the basic length (axial length) and obtain a large aperture characteristic with a small number of discs. Therefore, it is possible to adjust the throttling characteristics according to many damping force characteristics with a small number of kinds of parts.

In the first embodiment, the flow path forming member 22 is provided inside the storage member 25 , and the storage member 25 is connected to the piston rod 11 . Therefore, the flow path forming member 22 can be easily assembled to the piston rod 11 together with the housing member 25 . Moreover, the flow path forming member 22 is provided in the bottom side oil chamber B (one side chamber side) of the piston rod 11 which is located on the lower end side of the piston 6 . Therefore, it is possible to easily dispose the flow path forming member 22 in the bottom side oil chamber B as well.

Next, FIGS. 6 to 8 show a second embodiment. A feature of the second embodiment is that the number of discs is increased. In addition, in 2nd Embodiment, the same code|symbol shall be attached|subjected to the component same as 1st Embodiment mentioned above, and the description shall be abbreviate|omitted.

In the first embodiment, the flow path forming member 22 has one introduction disk 23 and one passage disk 24 . That is, the flow path forming member 22 of the first embodiment is composed of two discs 23 and 24 in total. On the other hand, in the second embodiment, the passage forming member 31 has one introduction disc 23, five passage discs 24, and four intermediate discs 32,33. That is, the flow path forming member 31 of the second embodiment is composed of ten disks 23, 24, 32, 33 in total. Accordingly, in the storage member 34, the axial dimension of the cylindrical portion 35 is longer than the axial dimension of the cylindrical portion 25A of the first embodiment.

The flow path forming member 31 includes, in order from the fixed member 21 side, an introduction disk 23, a passage disk 24 on the farthest other end side (upper end side), a first intermediate disk 32, and the front and back of the passage disk 24 on the farthest upper end side. The passage disk 24, the second intermediate disk 33, the passage disk 24, the first intermediate disk 32, the opposite passage disk 24, the second intermediate disk 33, and the passage disk 24 are laminated. The first intermediate disc 32 is provided with a through hole 32A at a position corresponding to the outer diameter side end portion 24C of the through groove 24A of the passage disc 24 . The second intermediate disc 33 is provided with a through hole 33A at a position corresponding to the inner diameter side end portion 24B of the through groove 24A of the passage disc 24 . Portions of the first intermediate disc 32 and the second intermediate disc 33 outside the through holes 32A and 33A form closing portions 32B and 33B that close the through groove 24A of the passage disc 24, respectively.

The outer peripheral surface of the first intermediate disk 32 is provided with a positioning protrusion 32C that protrudes radially outward from other portions at a position that is in phase with the through hole 32A in the circumferential direction. The outer peripheral surface of the second intermediate disk 33 is also provided with a positioning convex portion 33C that protrudes radially outward from the other portion at a position that is in phase with the through hole 33A in the circumferential direction. The positioning projections 23D of the introduction disk 23, the positioning projections 24D of the passage disk 24, the positioning projections 32C of the first intermediate disk 32, and the positioning projections 33C of the second intermediate disk 33 all correspond to the positioning recesses of the storage member 34. 25D. The positioning recess 25D is provided in the shape of a vertical groove on the inner peripheral surface of the cylindrical portion 35 at a position that is in phase with the through hole 25E of the bottom portion 25B in the circumferential direction. As a result, the discs 23, 24, 32, 33 are positioned in the circumferential direction and prevented from being displaced (rotated) in the circumferential direction.

In the second embodiment, by stacking the passage discs 24 upside down, the length of the throttle passage 18 can be arbitrarily adjusted according to the number of laminated sheets. In this case, the passage discs 24 are stacked upside down. Therefore, the throttle passage 18 extends while rotating in the same direction while changing the radius from the inside to the outside in the radial direction, or changing the radius from the outside to the inside. As a result, the throttle passage 18 can obtain a required flow path length. In addition, in the throttle passage 18, oil (working fluid) circulates in the same direction in all the passage discs 24. As shown in FIG. That is, the oil flows clockwise or counterclockwise according to expansion or contraction. Therefore, it is possible to suppress unnecessary pressure loss caused by changing the direction of the flow path. In addition, an arbitrary channel length can be set with a small number of types of parts.

That is, in the second embodiment as well, the throttle passage 18 can be constructed of the passage disk 24 as in the first embodiment. In this case, by adjusting the number of passage discs 24 according to the desired damping force characteristic, the throttle passage 18 can be adjusted to the required passage length. Moreover, for the thrust reduction characteristic, the passage disk 24 can be one as in the first embodiment. That is, the passage length of the throttle passage 18 can be easily adjusted by changing the number of passage discs 24 . By adjusting the passage length, it is possible to improve the rise of the damping force at very low speeds and obtain highly responsive damping force characteristics. In this case, the passage discs 24 are alternately stacked upside down. Therefore, as indicated by the arrows in FIG. 7, the flow from the inside to the outside in the radial direction and the flow from the outside to the inside are repeated. Thereby, the channel length can be ensured.

In the second embodiment, the discs 23, 24, 32, 33 as described above form the throttle passage 18, and the basic operation thereof is not particularly different from that of the first embodiment.

In particular, in the second embodiment, the passage forming member 31 includes the passage disc 24 as the first disc, the first intermediate disc 32 as the second disc, the passage disc 24 as the third disc, and the fourth disc. and a second intermediate disc 33 as a disc. A passage disk 24 as a first disk has a through groove 24A spirally extending in the circumferential direction. The first intermediate disc 32 receives the working fluid supplied to one side end (for example, the inner diameter side end portion 24B) of the through groove 24A of the passage disc 24, and the other side end (for example, the outer diameter side end portion 24C) of the through groove 24A. ), and a through hole 32A provided at a position corresponding to the other side end of the through groove 24A.

The passage disk 24 as the third disk is the opposite side of the passage disk 24 as the first disk. The second intermediate disc 33 receives the working fluid supplied to the other side end (for example, the outer diameter side end portion 24C) of the through groove 24A of the passage disc 24 (for example, the inner diameter side end portion 24B) of the through groove 24A. ), and a through hole 33A provided at a position corresponding to one side end of the through groove 24A. Therefore, it is possible to form the throttle passage 18 having a long passage length and a short axial length with a simple structure in which the first to fourth discs 24, 32 and 33 are stacked.

9 to 11 show a third embodiment. A feature of the third embodiment resides in that a channel forming member is incorporated in the piston. In addition, in 3rd Embodiment, the same code|symbol shall be attached|subjected to the component same as 1st Embodiment and 2nd Embodiment mentioned above, and the description shall be abbreviate|omitted.

The piston 41 has a bottomed tubular member 42 (compression-side piston body) as a first member, and a disc-shaped lid member 44 (extension-side piston body) as a second member. A flow path forming member 48 is provided between the cylindrical member 42 and the lid member 44 . In other words, the cylinder member 42 and the lid member 44 of the piston 41 correspond to a storage member that stores the flow path forming member 48 . The bottom portion 43 and the cover member 44 of the cylindrical member 42 are provided with insertion holes 43D and 44D located in the center and through which the small diameter portion 11A of the piston rod 11 is inserted. Further, the bottom 43 of the cylindrical member 42 and the lid part 44 are multiple oil pores 43a, 43B, 44a, 44a, 43a, 44a, 44a, which penetrates the axial direction (up and down direction) at the outside of the diameter direction than the insertion hole 43D, 44D. 44B is provided. The oil passage hole 43A of the cylindrical member 42 and the oil passage hole 44A of the lid member 44 constitute an oil passage 6A as a second communication passage together with the oil passage holes 49A, 50A and 51A of the discs 49, 50 and 51. .

Further, the oil passage hole 43B of the cylindrical member 42 and the oil passage hole 44B of the cover member 44 together with the oil passage holes 49A, 50A and 51A of the discs 49, 50 and 51 constitute an oil passage 6B as a third communication passage. ing. As shown in FIG. 10, between at least one set of oil passage holes 43B and 44B among the oil passage holes 43A and 43B of the cylindrical member 42 and the oil passage holes 44A and 44B of the cover member 44, these oil passage holes A cylindrical alignment pin 45 is provided for connecting (coupling) 43B and 44B. The positioning pins 45 are fitted in oil passage holes 49A, 50A and 51A of discs 49, 50 and 51, which will be described later, to position these discs 49, 50 and 51, the cylindrical member 42 and the lid member 44. As shown in FIG. The alignment pin 45 is a hollow spring pin whose inner side serves as a flow path, and forms the oil passage 6B together with the oil passage holes 43B and 44B.

The bottom portion 43 and the cover member 44 of the cylindrical member 42 are provided with introduction holes 43C and 44C which are located radially outside the oil passage holes 43A, 43B, 44A and 44B and extend through them in the axial direction. 43 C of introduction holes of the cylinder member 42 connect the flow-path formation member 48 and the rod side oil chamber C. As shown in FIG. 44 C of introduction holes of the cover member 44 connect the flow path formation member 48 and the bottom side oil chamber B. As shown in FIG. The piston 41 clamps (stores) the flow path forming member 48 (disks 49, 50, 51) together with the positioning pin 45 between the cylinder member 42 and the lid member 44, and the compression side disk valve 7 and the expansion side disk It is attached to the small diameter portion 11A of the piston rod 11 with a nut 47 together with the valve 8 and spacer 46 . A piston ring 41</b>A that slides on the inner peripheral surface of the inner cylinder 4 is provided on the outer peripheral side of the piston 41 .

The passage forming member 48 has a plurality of passage discs 49 and a plurality of blocking discs 50,51. As shown in order from (A) in FIG. 11 , the flow path forming member 48 includes, in order from the bottom 43 side of the cylindrical member 42 , the first closing disk 50 on the farthest other end side (upper end side), the farthest other end side ( 49 on the upper end side), the second closing disk 51 on the farthest other end side (upper end side), the passage disc 49 opposite to the front and back of the uppermost passage disc 49, the farthest on the other end side (upper end side) 1 First blocking disk 50 rotated by 180°, passage disk 49 rotated by 180° from uppermost passage disk 49, and second closing disk 51 on the othermost side (upper end side) rotated by 180°. A second closing disk 51 rotated, a passage disk 49 turned 180 degrees opposite to the uppermost passage disk 49, a first closing disk 50, . . . are laminated.

The passage disk 49 is provided with an insertion hole 49E located in the center and through which the small diameter portion 11A of the piston rod 11 is inserted. Further, the passage disc 49 is provided with an oil passage hole 49A positioned radially outside the insertion hole 49E and forming the oil passage 6A or the oil passage 6B. Further, the passage disk 49 is provided with a slit-shaped through groove 49B which is located on the outer diameter side of the oil passage hole 49A and extends in the circumferential direction. The through groove 49B of the passage disk 49 is formed in a spiral shape extending around the same plane. In this case, as shown in FIG. 11, the through groove 49B extends from the radially innermost inner diameter side end portion 49C of the passage disk 49 to the radially outermost outer diameter side end portion 49D. 3/4 or 630° circumferentially.

The first closing disk 50 is provided with an insertion hole 50D through which the small diameter portion 11A of the piston rod 11 is inserted, and an oil passage hole 50A forming the oil passage 6A or the oil passage 6B. A through hole 50B is provided in the first closing disk 50 at a position corresponding to the outer diameter side end portion 49D of the through groove 49B of the passage disk 49 . The second closing disk 51 is provided with an insertion hole 51D through which the small diameter portion 11A of the piston rod 11 is inserted, and an oil passage hole 51A forming the oil passage 6A or the oil passage 6B. The second closing disk 51 is provided with a through hole 51B at a position corresponding to the inner diameter end 49C of the through groove 49B of the passage disk 49 . The first closing disk 50 and the second closing disk 51 have a closing portion 50C that closes the through groove 49B of the passage disk 49 at portions outside the insertion holes 50D and 51D, the oil passage holes 50A and 51A, and the through holes 50B and 51B. , 51C.

In the third embodiment, the throttle passage 18 is formed by stacking three types of discs 49, 50, 51 by turning them upside down and/or rotating them. Moreover, the passage forming member 48 (discs 49 , 50 , 51 ) forming the throttle passage 18 is arranged inside the piston 41 . Therefore, the length of the throttle passage 18 can be secured without increasing the basic length. That is, the throttle passage 18 is constructed by stacking passage discs 49 each having a spiral through groove 49B extending in the circumferential direction. Therefore, by changing the number of passage discs 49, the length of the throttle passage 18 can be adjusted. Furthermore, on the inner diameter side of the through groove 49B of the passage disk 49, an oil passage hole 49A that forms an oil passage 6A that communicates with the pressure side disk valve 7, and an oil passage 6B that communicates with the expansion side disk valve 8 are formed. An oil passage hole 49A is provided. As a result, both the oil passages 6A and 6B serving as the main passages (main passages) and the throttle passage 18 serving as the sub passages (sub passages) can be provided in the passage disk 49. FIG.

In the third embodiment, the discs 49, 50, 51 as described above form the throttle passage 18, and the basic action thereof is different from those of the first and second embodiments. No difference.

That is, according to the third embodiment, the flow path forming member 48 includes the passage disk 49 as the first disk, the first closing disk 50 as the second disk, the passage disk 49 as the third disk, and a second blocking disk 51 as a fourth disk. A passage disk 49 as a first disk has a through groove 49B spirally extending in the circumferential direction. The first closing disk 50 receives the working fluid supplied to one side end (for example, the inner diameter side end portion 49C) of the through groove 49B of the passage disk 49, and the other side end (for example, the outer diameter side end portion 49D) of the through groove 49B. ), and a through hole 50B provided at a position corresponding to the other side end of the through groove 49B.

The passage disk 49 as the third disk is the opposite side of the passage disk 49 as the first disk. The second closing disk 51 receives the working fluid supplied to the other side end (for example, the outer diameter side end portion 49D) of the through groove 49B of the passage disk 49 (for example, the inner diameter side end portion 49C) of the through groove 49B. ), and a through hole 51B provided at a position corresponding to one side end of the through groove 49B. Therefore, with a simple structure in which the first to fourth disks 49, 50, 51 are stacked, the throttle passage 18 having a long passage length and a short axial length can be formed.

Further, according to the third embodiment, the flow path forming member 48 (disks 49, 50, 51) is provided between the cylindrical member 42 as the first member of the piston 41 and the lid member 44 as the second member. is provided. Therefore, the flow path forming member 48 (disks 49, 50, 51) can be built in the piston 41 (the flow path forming member 48 and the piston 41 are provided integrally), thereby suppressing an increase in axial dimension. While the length of the throttle passage 18 can be ensured.

Next, FIGS. 12 and 13 show a fourth embodiment. The feature of the fourth embodiment resides in that the passage forming member is disposed on the other side chamber side of the piston (rod side oil chamber) and the housing member is omitted. In addition, in the fourth embodiment, the same reference numerals are given to the same components as in the above-described first to third embodiments, and the description thereof will be omitted.

In the fourth embodiment, the passage forming member 66 is provided on the other side chamber side of the piston 6, that is, in the rod side oil chamber C. As shown in FIG. In this case, the flow path forming member 66 is arranged on the base end side (upper end side) of the small diameter portion 11A of the piston rod 11 . The flow path forming member 66 is attached to the small diameter portion 11A of the piston rod 11 with a nut 47 together with the compression side disk valve 7, the piston 6, the expansion side disk valve 8, and the spacers 46, 62. The flow passage forming member 66 is sandwiched between a pair of spacers 62 , 62 between the shoulder portion 61 forming a stepped portion of the piston rod 11 and the pressure side disk valve 7 on the upper surface side of the piston 6 . The small diameter portion 11A of the piston rod 11 is provided with a flat portion 63 extending in the axial direction. The flat portion 63 positions the flow path forming member 66 (disks 67, 68, 69, 70) and also serves as a rod-side passage connecting the throttle passage 18 of the flow path forming member 66 and the bottom-side oil chamber B. 64. The rod-side passage 64, together with the throttle passage 18, constitutes a sub-passage 65 provided in parallel with the oil passages 6A and 6B.

The passage forming member 66 has a plurality of passage discs 67 , a plurality of blocking discs 68 and 69 and an introduction disc 70 . As shown in order from (A) in FIG. 13 , the flow passage forming member 66 is arranged, in order from the spacer 62 side of the shoulder portion 61 of the piston rod 11 , the first closing disk 68 , the passage on the farthest other end side (upper end side). A disk 67, a second closing disk 69, a passage disk 67 opposite to the uppermost passage disk 67, a first closing disk 68, a passage disk 67, and an introduction disk 70 are laminated.

The passage disk 67 is provided with an insertion hole 67A located in the center and through which the small diameter portion 11A of the piston rod 11 is inserted. The insertion hole 67A has a D-shaped cross section corresponding to the flat portion 63 of the piston rod 11 (small diameter portion 11A). Further, the passage disc 67 is provided with a slit-shaped through groove 67B which is located on the outer diameter side of the insertion hole 67A and extends in the circumferential direction. Similar to the through groove 24A of the first embodiment, the through groove 67B of the passage disk 67 extends from the radially innermost inner diameter side end 67C to the radially outermost outer diameter side end 67D. It extends spirally in two turns, that is, 720° in the circumferential direction.

The first closing disk 68 is provided with an insertion hole 68A having a D-shaped cross section through which the small diameter portion 11A of the piston rod 11 is inserted. A through hole 68B is provided in the first closing disk 68 at a position corresponding to the outer diameter side end 67D of the through groove 67B of the passage disk 67 . The second closing disk 69 is provided with an insertion hole 69A having a D-shaped cross section through which the small diameter portion 11A of the piston rod 11 is inserted. The second closing disk 69 is provided with a through hole 69B at a position corresponding to the inner diameter side end 67C of the through groove 67B of the passage disk 67 . The introduction disk 70 is provided with an insertion hole 70A having a D-shaped cross section through which the small diameter portion 11A of the piston rod 11 is inserted. The introduction disk 70 is provided with a through groove 70B extending radially from the insertion hole 70A to a position corresponding to the inner diameter end 67C of the through groove 67B of the passage disk 67 . The first closing disk 68 and the second closing disk 69 have closed portions 68C and 69C that close the through groove 67B of the passage disk 67 at portions outside the insertion holes 68A and 69A and the through holes 68B and 69B. A portion of the introduction disk 70 that is separated from the insertion hole 70A and the through groove 70B serves as a closing portion 70C that closes the through groove 67B of the passage disk 67. As shown in FIG.

Positioning of the flow path forming member 66 in the circumferential direction, that is, positioning of the discs 67, 68, 69, 70 in the rotational direction is performed by D-shaped insertion holes 67A, 68A, 69A and 70A. That is, the contact between the straight portions of the insertion holes 67A, 68A, 69A, and 70A and the flat portion 63 of the piston rod 11 (the small diameter portion 11A) positions the discs 67, 68, 69, and 70 and moves them in the circumferential direction. displacement (rotation) of is prevented. In addition, the flat portion 63 of the piston rod 11 (small diameter portion 11A) is formed between the inner surface of the compression side disc valve 7, the inner surface of the piston 6, the inner surface of the extension side disc valve 8, the inner surface of the spacer 46, and the inner surface of the nut 47. A side passage 64 is constructed. The rod-side passage 64 connects between the through groove 70B of the introduction disk 70 and the bottom-side oil chamber B. As shown in FIG. Also, as shown in FIG. 12, the thickness of the first closing disk 68 (excluding the first closing disk 68 on the uppermost end) and the thickness of the second closing disk 69 are the same as the thickness of the passage disk 67 and the introduction disk 70. is thinner than the thickness of The thickness of the first closing disk 68 on the uppermost end side and the thickness of the other first closing disks 68 may be made the same so as to share parts (the same parts may be used).

In the fourth embodiment, the discs 67, 68, 69, 70 as described above form the throttle passage 18, and the basic operation thereof is the same as in the first to third embodiments described above. and there is no particular difference.

That is, according to the fourth embodiment, the passage forming member 66 includes the passage disc 67 as the first disc, the first closing disc 68 as the second disc, the passage disc 67 as the third disc, and a second closing disk 69 as a fourth disk. A passage disk 67 as a first disk has a through groove 67B spirally extending in the circumferential direction. The first closing disk 68 includes a closing portion 68C that closes the through groove 67B of the passage disk 67, and a through hole 68B provided at a position corresponding to the other side end (for example, the outer diameter side end portion 67D) of the through groove 67B. have. The passage disk 67 as the third disk is the opposite side of the passage disk 67 as the first disk. The second closing disk 69 has a closing portion 69C that closes the through groove 67B of the passage disk 67, and a through hole 69B provided at a position corresponding to one side end (for example, the inner diameter side end portion 67C) of the through groove 67B. have. Therefore, it is possible to form the throttle passage 18 having a long passage length and a short axial length with a simple structure in which the first to fourth discs 67, 68, 69 are stacked.

Further, in the fourth embodiment, the passage forming member 66 is directly connected to the piston rod 11 without using a housing member for housing the passage forming member 66 . Therefore, the outer diameters of the disks 67, 68, 69, 70 can be increased. As a result, the passage length per disc can be lengthened, and a large passage length can be adjusted with a small number of discs. Moreover, the flow path forming member 66 is provided in the rod-side oil chamber C (on the other side chamber side) of the piston rod 11 that is on the upper end side of the piston 6 . Therefore, the flow path forming member 66 can be easily arranged in the rod-side oil chamber C. As shown in FIG. Further, the conventional process can be used as the process for assembling the flow path forming member 66, and from this point of view as well, the high-performance shock absorber 1 can be obtained at low cost.

Next, FIGS. 14 and 15 show a fifth embodiment. The feature of the fifth embodiment resides in that the passage forming member is disposed on the one side chamber side (bottom side oil chamber) of the piston and the storage member is omitted. In addition, in the fifth embodiment, the same reference numerals are given to the same constituent elements as in the first to fourth embodiments described above, and the description thereof will be omitted.

In the fifth embodiment, the flow path forming member 71 is provided on the one side chamber side of the piston 6, that is, in the bottom side oil chamber B. As shown in FIG. In this case, the flow path forming member 71 is positioned closer to the tip (closer to the lower end) of the small diameter portion 11A of the piston rod 11, in other words, above (base end side) the lower end (tip) of the small diameter portion 11A and closer to the piston 6 than the small diameter portion 11A. placed on the bottom. The flow path forming member 71 is attached to the small diameter portion 11A of the piston rod 11 by a nut 47 together with the compression side disk valve 7, the piston 6, the expansion side disk valve 8, spacers 46, 62 and 72. The flow passage forming member 71 is sandwiched by a pair of spacers 46 and 62 between the extension side disk valve 8 on the lower surface side of the piston 6 and the nut 47 . The small diameter portion 11A of the piston rod 11 is provided with a flat portion 63 extending in the axial direction.

The flat portion 63 positions the flow passage forming member 71 (discs 67, 68, 69, 70) and also serves as a rod side passage connecting the rod side oil chamber C and the throttle passage 18 of the flow passage forming member 71. 73. The rod-side passage 73, together with the throttle passage 18, constitutes a sub-passage 74 provided in parallel with the oil passages 6A and 6B. That is, the flat portion 63 of the piston rod 11 (small diameter portion 11A) is the inner surface of the spacer 72 adjacent to the compression side disk valve 7, the inner surface of the compression side disk valve 7, the inner surface of the piston 6, the inner surface of the extension side disk valve 8, the extension side A rod-side passage 73 is formed between the disk valve 8 and the inner surface of the adjacent spacer 62 . In this case, the spacer 72 adjacent to the compression side disk valve 7 is formed with a through groove 72A extending in the radial direction and opening to the rod side oil chamber C. As shown in FIG. The spacer 72 may be the same component as the disk 70 with the same outer diameter.

The passage forming member 71 has a plurality of passage discs 67 , a plurality of blocking discs 68 and 69 and an introduction disc 70 . As shown in order from (A) in FIG. 15 , the flow path forming member 71 includes an introduction disk 70 and a passage disk 67 on the farthest other end side (upper end side) in order from the side of the spacer 62 adjacent to the extension side disk valve 8 . , a first closing disk 68, a passage disk 67 opposite to the uppermost passage disk 67, a second closing disk 69, a passage disk 67, and a first closing disk 68 are laminated.

In the fifth embodiment, the discs 67, 68, 69 and 70 as described above form the throttle passage 18, and the basic operation thereof is the same as in the first to fourth embodiments described above. and there is no particular difference.

In particular, in the fifth embodiment, similarly to the fourth embodiment, the passage forming member 71 is connected to the piston rod 11 without using a housing member for housing the passage forming member 71 . Therefore, the outer diameters of the disks 67, 68, 69, 70 can be increased. As a result, the passage length per disc can be lengthened, and a large passage length can be adjusted with a small number of discs. Moreover, the flow path forming member 71 is provided in the bottom side oil chamber B (one side chamber side) of the piston rod 11 which is on the lower end side of the piston 6 . Therefore, the flow path forming member 71 can be easily arranged in the bottom side oil chamber B. As shown in FIG. In addition, the conventional process can be used as the process for assembling the flow path forming member 71, and from this point of view as well, the high-performance shock absorber 1 can be obtained at low cost.

Next, FIGS. 16 and 17 show a sixth embodiment. A feature of the sixth embodiment resides in that the communication path (first communication path) is formed by a bottomed groove. In addition, in the sixth embodiment, the same reference numerals are assigned to the same components as in the first to fifth embodiments described above, and the description thereof will be omitted.

The passage forming unit 81 includes a fixing member 21 , a flow passage forming member 82 and a housing member 25 . The passage forming member 82 has an introduction disk 23 and passage disks 83 and 84 . The passage discs 83, 84 have bottomed grooves 83A, 84A spirally extending in the circumferential direction. The cross-sections of the bottomed grooves 83A and 84A can be rectangular as shown in FIG. 16, for example. However, although not shown in the drawings, for example, a bottomed groove having a trapezoidal cross section in which the side surface is inclined so that the groove width becomes smaller toward the bottom, a U-shaped cross section having an arcuate bottom. Various bottomed grooves such as a bottomed groove, a bottomed groove having a semicircular cross section, and the like can be employed. As shown in order from (A) in FIG. 17, the flow path forming member 82 includes an introduction disk 23, a first passage disk 83, a second passage disk 84, and a first passage disk 83 stacked in order from the fixed member 21 side. It is configured by

That is, the passage forming member 82 includes a first passage disk 83 as a fifth disk and a second passage disk 84 as a sixth disk. The first passage disk 83 includes a first bottomed groove 83A spirally extending in the circumferential direction, and a first through hole 83D provided at an end (for example, an outer diameter side end 83C) of the first bottomed groove 83A. have. As shown in FIG. 17, the first bottomed groove 83A extends from the radially innermost inner diameter side end 83B of the first passage disk 83 to the radially outermost outer diameter side end 83C. It extends circumferentially, that is, 720° circumferentially (clockwise). A first through hole 83D is provided in the outer diameter side end portion 83C of the first bottomed groove 83A.

The second passage disk 84 includes a second bottomed groove 84A spirally extending in a direction opposite to the first bottomed groove 83A of the first passage disk 83, and an end portion (for example, , inner diameter side end portion 84B). As shown in FIG. 17, the second bottomed groove 84A extends from the radially innermost inner diameter side end 84B of the second passage disk 84 to the radially outermost outer diameter side end 84C. It extends circumferentially, that is, 720° circumferentially (counterclockwise). A second through hole 84D is provided at an inner diameter side end portion 84B of the second bottomed groove 84A. Positioning protrusions 83E and 84E are provided on the outer peripheral surface of the first passage disk 83 and the outer peripheral surface of the second passage disk 84, and protrude radially outward from the other portions. The positioning protrusions 83E and 84E are engaged with a vertical groove-shaped positioning recess 25D provided on the inner peripheral surface of the cylindrical portion 25A of the storage member 25. As shown in FIG.

In the sixth embodiment, the passage discs 83 and 84 having the spiral bottomed grooves 83A and 84A are provided with a through hole 83D at the outer diameter side end 83C of the spiral bottomed groove 83A, The necessary flow path length is adjusted by alternately stacking two kinds of bottomed spiral grooves 84A with the second through-holes 84D provided at the inner diameter side end portions 84B of the spiral grooves 84A. The groove shape (cross-sectional shape) of the bottomed grooves 83A and 84A may be rectangular, trapezoidal, semicircular, or any other shape. The passage discs 83 and 84 having the spiral bottomed grooves 83A and 84A can be processed by mechanical processing of metal material, plastic processing such as forging and pressing, molding by sintered alloy, molding by resin material (resin molding). ), etc., using various methods and materials. In the above-described first to fifth embodiments as well, the "passage disc and intermediate disc having through grooves" or the "passage disc and closing disc having through grooves" are referred to as bottomed grooves. And it may be changed to a passage disk in which a through hole is formed.

In the sixth embodiment, the throttle passage 18 is formed by the passage discs 83 and 84 as described above, and its basic action is significantly different from those according to the first to fifth embodiments described above. no. In particular, in the sixth embodiment, the throttle passage 18 is composed of bottomed grooves 83A and 84A. Therefore, a communication passage having a long passage length and a short axial length can be formed by a simple structure in which two types of passage discs 83 and 84 are laminated.

Next, FIGS. 18 and 19 show a seventh embodiment. The feature of the seventh embodiment resides in that the piston rod is provided with the frequency sensitive portion together with the flow path forming member. In the seventh embodiment, the same reference numerals are given to the same constituent elements as in the above-described first to sixth embodiments, and the description thereof will be omitted.

In the seventh embodiment, the piston rod 11 is provided with the frequency sensitive portion 91 and the flow path forming member 97 . The frequency sensitive part 91 has a free piston 93 as a movable member that can be moved by the working fluid of the bottom side oil chamber B and/or the rod side oil chamber C. As shown in FIG. That is, the frequency sensitive part 91 is provided on the lower end side of the piston rod 11 . The frequency sensitive part 91 includes a cylindrical case 92 that is displaced inside the inner cylinder 4 integrally with the piston rod 11, a free piston 93 that is provided in the case 92 and is movable (relatively displaceable) in the case 92, and a free piston 93. O-rings 94 and 95 are provided as spring members for urging the piston 93 .

The case 92 is attached by screwing to a bottomed tubular connecting portion 92A projecting from the bottom portion 25B of the housing member 25 that houses the passage forming member 97 toward the bottom side oil chamber B side, and the connecting portion 92A. It is composed of a cylindrical body 92B. The connecting portion 92A includes a bottom portion 92C connected to the bottom portion 25B of the storage member 25, and a cylindrical portion 92D extending from the outer diameter side of the bottom portion 92C toward the bottom side oil chamber B side. A bottom portion 92C of the connecting portion 92A and a bottom portion 25B of the storage member 25 are provided with an inner hole 92E that penetrates them in the axial direction (vertical direction).

The inner hole 92E extends through a central hole 98A provided in the passage disc 98, a central hole 23A provided in the introduction disc 23, an intermediate passage 17 of the fixed member 21, and a rod side oil chamber 16 of the piston rod 11. communicates with C. A male threaded portion 92F that screws together with a female threaded portion 92G of the tubular body 92B is provided on the outer peripheral side of the tubular portion 92D. A lower end surface of the cylindrical portion 92D serves as a contact surface 92H with which the O-ring 94 contacts.

The upper end side of the cylinder 92B is fixed to the cylinder portion 92D of the connecting portion 92A by screwing. For this reason, a female threaded portion 92G that is screwed with the male threaded portion 92F of the connecting portion 92A is provided on the inner peripheral side of the upper end side of the tubular body 92B. A contact surface 92J with which the O-ring 95 contacts is formed on the inner peripheral side of the cylindrical body 92B.

The free piston 93 is slidably provided within the case 92 . The free piston 93 is formed as a cylindrical piston with a bottom. An annular protrusion 93A is provided on the outer peripheral side of the free piston 93 and protrudes radially outward from an intermediate position in the axial direction. The free piston 93 forms an oil chamber 96 inside the case 92 . The annular convex portion 93A of the free piston 93 has contact surfaces 93B and 93C that contact the O-rings 94 and 95 at its upper and lower surfaces, respectively.

The O-rings 94, 95 are elastic bodies constituting the resistance element of the frequency sensitive portion 91. The O-rings 94, 95 are arranged between the cylindrical body 92B of the case 92 and the outer peripheral surface of the free piston 93, is liquid-tightly sealed between An oil chamber 96 in the case 92 and the free piston 93 and the bottom-side oil chamber B are held in a sealed state by O-rings 94 and 95 . The frequency sensitive portion 91 has a function of reducing the damping force generated by relative displacement of the free piston 93 in the axial direction within the case 92 against high frequency vibrations during vehicle travel. In this case, the frequency sensitive part 91 acts in both directions of extension and retraction of the piston rod 11 .

The passage forming member 97 has an introduction disk 23 and a passage disk 98 . The passage disk 98 is similar to the passage disk 24 of the first embodiment except that it is provided with a central hole 98A. That is, the passage disc 98 is provided with a through groove 24A, like the passage disc 24 of the first embodiment. A central hole 98A of the passage disk 98 constitutes an introduction orifice provided in the middle of the flow path 99 communicating with the oil chamber 96 of the free piston 93. As shown in FIG.

That is, in the seventh embodiment, the free piston 93 and the O-rings 94 and 95 are arranged in the flow path 99 parallel to the oil passage 6A of the compression side disc valve 7 and the oil passage 6B of the expansion side disc valve 8. . The O-rings 94, 95 serve as both a spring acting on the free piston 93 and a seal. A frequency sensitive portion 91 serving as a frequency sensitive valve has an introduction orifice in the middle of a flow path 99 communicating with an oil chamber 96 of a free piston 93 . The introduction orifice is constituted by a central hole 98A provided in the center of the passage disc 98 of the passage forming member 97. As shown in FIG. As described above, in the seventh embodiment, the frequency sensitive portion 91 and the passage disc 98 forming the spiral passage (throttle passage 18) are combined and arranged at the lower end side of the piston rod 11. FIG.

The seventh embodiment includes the frequency sensitive portion 91 and the flow path forming member 97 as described above, and its basic action is distinct from those of the first to sixth embodiments described above. No difference. In particular, in the seventh embodiment, the piston rod 11 is provided with the frequency sensitive portion 91 and the flow path forming member 97 . Therefore, the flow path forming member 97 can be assembled to the piston rod 11 together with the frequency sensitive portion 91 . In this case, the frequency sensitive part 91 having the case 92 , the free piston 93 and the O-rings 94 and 95 can be assembled to the piston rod 11 together with the flow path forming member 97 .

Here, since the frequency sensitive part 91 has a free piston 93, that is, a movable part, the movement of this movable part tends to cause a delay in the rising characteristic of the damping force. On the other hand, in the seventh embodiment, the narrowed passage 18 formed by the passage forming member 22 of the passage forming unit 20, that is, the spiral narrowed passage 18 is combined with the frequency sensitive portion 91 in parallel. As a result, the damping force rising characteristic can be improved, and the disadvantages of the frequency sensitive section 91 can be compensated.

Next, FIG. 20 shows an eighth embodiment. The feature of the eighth embodiment resides in that a frequency sensitive portion acting on the back pressure chamber of the disc valve (extension side disc valve) of the piston is provided. In addition, in the eighth embodiment, the same reference numerals are given to the same constituent elements as in the first to seventh embodiments described above, and the description thereof will be omitted.

The small diameter portion 11A of the piston rod 11 is provided with a passage forming unit 20 (flow passage forming member 22) similar to that of the first embodiment. Further, the small diameter portion 11A of the piston rod 11 is provided with a frequency sensitive portion 101 located between the piston 6 and the passage forming unit 20. As shown in FIG. The frequency sensitive part 101 acts on the back pressure chamber 103 of the extension side disc valve 102 of the piston 6 .

That is, an extension side damping force generating portion 104 is provided on the lower surface of the piston 6 . The extension-side damping force generating portion 104 suppresses the flow of hydraulic fluid (working fluid) from the upstream side chamber (rod side oil chamber C) to the downstream side chamber (bottom side oil chamber B) caused by the movement of the piston 6. a back pressure chamber 103 that applies back pressure in the closing direction of the extension side disk valve 102; and hydraulic fluid from the upstream chamber is introduced into the back pressure chamber 103. A back pressure chamber introduction orifice 105 for doing so, an elastic seal member 102B that adjusts the opening of the expansion side disk valve 102 by the back pressure of the back pressure chamber 103, and a free valve 106 that reduces the damping force against high frequency vibration and The free valve 106 constitutes the frequency sensitive section 101 .

A plurality of recessed grooves 108 that always communicate with the inside of the annular recessed portion 107 of the piston 6 are formed in the outer peripheral surface of the small diameter portion 11A of the piston rod 11 so as to extend in the axial direction. The recessed groove 108 communicates with the back pressure chamber 103 via the back pressure chamber introduction orifice 105 . The extension-side damping force generating portion 104 is located in the bottom-side oil chamber B of the inner cylinder 4 and is attached to the lower side of the piston 6 in a fixed state. The extension-side damping force generating portion 104 extends from the rod-side oil chamber C to the oil passage 6B of the piston 6 and the annular A damping force on the extension side is generated with a predetermined characteristic by giving resistance to pressure oil flowing toward the bottom side oil chamber B via the recessed portion 107 and the like.

For this reason, the extension-side damping force generating portion 104 is a valve seat member positioned between the piston 6 and the passage forming unit 20 (fixing member 21) and fixed to the outer peripheral side of the piston rod 11 (small diameter portion 11A). 109 , the extension side disk valve 102 , and the free valve 106 that constitutes the frequency sensitive portion 101 . The expansion side disk valve 102 has an elastic seal member 102B that fits with an interference on the inner peripheral side of the valve seat member 109, and the first valve that forms an annular back pressure chamber 103 between the valve seat member 109 and the valve seat member 109. is. The valve seat member 109 includes an annular plate portion 109A fitted to the outer peripheral side of the small diameter portion 11A and the other side formed on the upper surface of the annular plate portion 109A and extending axially upward (the other side) from the outer peripheral side. A tubular portion 109B, a one-side tubular portion 109C formed on the lower surface of the annular plate portion 109A and extending axially downward (the other side) from the outer peripheral side, and a radially intermediate portion of the annular plate portion 109A drilled to the other side. It includes a through hole 109D that communicates the inside of the tubular portion 109B with the inside of the one-side tubular portion 109C. A free valve 106 is accommodated inside the one-side cylindrical portion 109C.

The expansion side disk valve 102 is composed of a main disk 102A that is seated on and off the annular valve seat 110 of the piston 6, and an annular elastic seal member 102B that is provided on the outer circumference of the lower surface of the main disk 102A. The elastic seal member 102B is formed in a thick ring shape using an elastic material such as rubber, and is positioned between the inner back pressure chamber 103 (that is, the other side cylindrical portion 109B) with respect to the outer bottom side oil chamber B. ) are liquid-tightly sealed. The elastic seal member 102B contacts the inner peripheral surface of the other side cylindrical portion 109B of the valve seat member 109 in an elastically deformed state, and the back pressure of the back pressure chamber 103 causes the main disc 102A, that is, the expansion side disc valve 102 to move. It constitutes a pressure adjustment mechanism that adjusts the opening of the valve. In the extension side disk valve 102, pressure oil from the rod side oil chamber C is introduced into the back pressure chamber 103 through the oil passage 6B of the piston 6, the annular recess 107, the back pressure chamber introduction orifice 105, etc. during the extension stroke of the piston rod 11. , a pressure difference is generated between the rod-side oil chamber C (annular recess 107 ) and the back pressure chamber 103 . Then, when this pressure difference becomes larger than a predetermined valve opening set pressure, the main disk 102A of the extension side disk valve 102 is separated from the annular valve seat 110 to generate a predetermined extension side damping force. do.

When the extension side disk valve 102 (main disk 102A) is open, the bottom side oil chamber B and the rod side oil chamber C communicate with each other via the oil passage 6B of the piston 6, the annular recess 107 and the annular valve seat 110. . On the other hand, when the extension side disk valve 102 (main disk 102A) is closed, for example, pressure oil in the rod side oil chamber C flows through the oil passage 6B of the piston 6, the annular recess 107, the annular recess 107 and the piston rod 11 (small diameter portion 11A). ) into the back pressure chamber 103 through the passage 113 connecting the groove 108, the groove 108, the back pressure chamber introduction orifice 105, and the like. The extension-side damping force generating portion 104 has a free valve 106 provided inside the one-side cylindrical portion 109C of the valve seat member 109 . The free valve 106 is composed of a disc valve 106A and an annular elastic seal member 106B. The disk valve 106A of the free valve 106 is mounted inside the one-side tubular portion 109C of the valve seat member 109 via a plurality of valve seat disks 111 and a cover plate 112. As shown in FIG. The disk valve 106A is configured as a check valve body that is seated on and off the outer peripheral side of the valve seat disk 111 .

The elastic seal member 106B of the free valve 106 is fixed to the outer peripheral side of the disc valve 106A. The elastic seal member 106B is formed in a ring shape using an elastic material such as rubber, and is in liquid-tight contact with the inner peripheral surface of the one-side tubular portion 109C with an interference. As a result, the inside of the one-side cylindrical portion 109C of the valve seat member 109 is partitioned by the free valve 106 into a frequency sensitive damper upper chamber D1 and a damper lower chamber D2. The damper upper chamber D1 communicates with the back pressure chamber 103 via a through hole 109D of the valve seat member 109 (annular plate portion 109A).

Here, the volume inside the damper upper chamber D1 is expanded or contracted by displacement (including elastic deformation) of the disk valve 106A and the elastic seal member 106B. In this case, the free valve 106 is configured as a frequency sensitive valve that adjusts the pressure (internal pressure) inside the back pressure chamber 103 . The cover plate 112 is fitted between the outer peripheral side of the piston rod 11 (small diameter portion 11A) and the inner peripheral side of the one-side cylindrical portion 109C, and is provided between the valve seat disc 111 and the passage forming unit 20. It is sandwiched by the fastening force from the fixing member 21 . A through hole 112</b>A is formed in the vertical direction at a radially intermediate portion of the cover plate 112 . The through hole 112A is a communication hole that always communicates the inside of the one side cylindrical portion 109C (damper lower chamber D2) of the valve seat member 109 with the bottom side oil chamber B.

In the free valve 106, the disk valve 106A as a check valve body continues to be seated on the outer peripheral side of the valve seat disk 111 during the extension stroke of the piston rod 11, and in this state, the vibration frequency of the piston rod 11 and/or the inner cylinder 4 is controlled. Accordingly, it is relatively displaced so as to move or stop vertically in the one-side tubular portion 109C. Thereby, the free valve 106 operates as a frequency sensitive valve that adjusts the internal pressure of the damper upper chamber D1 (that is, the back pressure chamber 103) according to the frequency. On the other hand, in the compression stroke of the piston rod 11, the damper lower chamber D2 becomes relatively higher in pressure than the damper upper chamber D1. Open the valve so as to leave the seat from the side. As a result, pressure oil (working fluid) in the bottom side oil chamber B flows from the damper lower chamber D2 to the back pressure chamber 103 via the damper upper chamber D1 and the through hole 109D of the valve seat member 109 (annular plate portion 109A). , and part of it flows toward the rod-side oil chamber C from the annular recess 107 of the piston 6 and the oil passage 6B via the back pressure chamber introduction orifice 105 .

Between the annular recess 107 of the piston 6 and the main disk 102A of the extension side disk valve 102, a back pressure chamber introduction orifice 105 communicating with the groove 108 of the piston rod 11 (small diameter portion 11A) is provided. The back pressure chamber introduction orifice 105 introduces pressure oil from the rod side oil chamber C into the back pressure chamber 103 through the oil passage 6B of the piston 6, the annular recess 107, the passage 113, and the recess groove . Further, the back pressure chamber 103 communicates with the damper upper chamber D1 through the through hole 109D of the valve seat member 109 (annular plate portion 109A). Therefore, pressure oil from the rod-side oil chamber C is supplied to the damper upper chamber D1 through the oil passage 6B of the piston 6, the annular recess 107, the passage 113, the recess groove 108, the back pressure chamber 103, and the through hole 109D. be. The back pressure chamber introduction orifice 105 is formed with a predetermined orifice area in order to determine the cutoff frequency of the free valve 106 .

That is, in the extension stroke of the piston rod 11, the displacement (including elastic deformation) of the disk valve 106A of the free valve 106 and the elastic seal member 106B expands the volume in the damper upper chamber D1. In this expanded range, the pressure oil in the back pressure chamber 103 flows toward the damper upper chamber D1. For this reason, the pressure in the back pressure chamber 103 decreases due to the displacement of the free valve 106, and the valve opening setting pressure of the expansion side disk valve 102 is decreased accordingly. As a result, the extension side disk valve 102 is switched from a hard state to a soft state in terms of damping force characteristics before and after the cutoff frequency.

Thus, the free valve 106 operates as a frequency sensitive valve that adjusts the internal pressure of the damper upper chamber D1 (that is, the back pressure chamber 103) according to the vibration frequency of the piston rod 11 and/or the inner cylinder 4. When the vibration frequency of the piston rod 11 and/or the inner cylinder 4 is a low frequency lower than the cutoff frequency, the extension side disk valve 102 is opened without the pressure in the back pressure chamber 103 being lowered by the free valve 106. The valve set pressure is kept at a relatively high pressure. However, when the vibration frequency is at a high frequency equal to or higher than the cutoff frequency, the pressure in the back pressure chamber 103 is lowered by the free valve 106, and the valve opening set pressure of the rebound side disk valve 102 is lowered. Switch to soft state.

In the eighth embodiment, a free valve 106 (frequency Equipped with a sensitive valve). The extension side disk valve 102 and the free valve 106 are assembled together with the passage forming unit 20 to the lower end of the piston rod 11 . In this case, the frequency sensitive part 101 (free valve 106, which is a frequency sensitive valve) acts only on the extension stroke. Further, as a function of frequency sensitivity, as the frequency increases, the valve opening pressure of the extension side disk valve 102 is reduced, and the damping force can be varied up to a high piston speed.

The throttle passage 18 formed by the flow passage forming member 22 of the passage forming unit 20, that is, the spiral throttle passage 18 is connected to the sub passage 15, which is a communication passage parallel to the oil passage 6B of the expansion side disk valve 102 and the compression side disk valve 7. is provided. Therefore, the effect of improving the damping force rise characteristic and the effect of improving the delay at high frequencies by the spiral throttle passage 18 can be obtained in both expansion and contraction. That is, the delay in the rise of the damping force caused by the frequency sensitive section 101 (free valve 106) can be improved by combining the spiral throttle passages 18 in parallel, and the disadvantages of the frequency sensitive section 101 can be compensated.

The eighth embodiment includes the frequency sensitive section 101 as described above and the passage forming unit 20 (the flow passage forming member 22) similar to the first embodiment. There is no particular difference from the first to seventh embodiments.

In particular, in the eighth embodiment, the piston rod 11 is provided with the frequency sensitive portion 101 having the free valve 106 which is a movable member that can be moved by the hydraulic oil (working fluid) of the bottom-side oil chamber B and the rod-side oil chamber C. It is The frequency sensitive part 101 includes a back pressure chamber 103 that acts on the extension side disk valve 102 that is the second valve of the piston 6, a free valve 106 (disk valve 106A) that acts on the pressure in the back pressure chamber 103, and a free valve and a spring member (elastic sealing member 106B) that biases 106 (disk valve 106A). For this reason, the frequency sensitive part 101 can adjust the pressure of the back pressure chamber 103 acting on the expansion side disk valve 102 according to the frequency. That is, in the eighth embodiment, the frequency sensitive section 101 can be provided integrally with the piston 6. FIG.

21 and 22 show a ninth embodiment. A feature of the ninth embodiment is that a flow path forming member is provided in a damping force adjustable shock absorber having a damping force adjusting valve. In the ninth embodiment, the same reference numerals are given to the same components as in the first to eighth embodiments described above, and the description thereof will be omitted.

A damping force adjustable hydraulic damper 121 (hereinafter referred to as damper 121) includes an outer cylinder 2, an inner cylinder 4, a piston 6, a piston rod 11, a passage forming unit 20, an intermediate cylinder 126, a bottom valve 127, and a damping force adjusting device. 131 and the like. The damping force generated by the buffer 121 is variably adjusted by a damping force adjusting device 131, which is a damping force adjusting mechanism, according to a control command from a controller (not shown).

An opening 122 is formed concentrically with the connection port 126C of the intermediate cylinder 126 on the lower side of the outer cylinder 2 . A damping force adjusting device 131 is attached to the lower side of the outer cylinder 2 so as to face the opening 122 . An oil hole 123 is formed in the radial direction of the inner cylinder 4 at an intermediate position in the lengthwise direction (axial direction) so that the rod-side oil chamber C always communicates with the annular oil chamber E. As shown in FIG. The small diameter portion 11A of the piston rod 11 is provided with a passage forming unit 20 (flow passage forming member 31) similar to that of the second embodiment.

A disc valve 124 on the extension side is provided on the lower end surface of the piston 6 . The extension-side disk valve 124 opens when the pressure in the rod-side oil chamber C exceeds the relief set pressure when the piston 6 slides upward in the extension stroke of the piston rod 11, and the pressure at this time is is relieved to the bottom side oil chamber B side through each oil passage 6B. The relief set pressure is set to a pressure higher than the valve opening pressure when the damping force adjustment device 131 is set to Hard.

A contraction side check valve 125 is provided on the upper end surface of the piston 6. The check valve 125 opens when the piston 6 slides downward in the contraction stroke of the piston rod 11, and closes otherwise. The check valve 125 allows the oil in the bottom side oil chamber B to flow through the oil passages 6A toward the rod side oil chamber C, and prevents the oil from flowing in the opposite direction. . The opening pressure of the check valve 125 is set, for example, to a pressure lower than the valve opening pressure when the damping force adjustment device 131 is set to soft, so that substantially no damping force is generated.

An intermediate cylinder 126 is arranged between the outer cylinder 2 and the inner cylinder 4 . The intermediate tube 126 is attached, for example, to the outer peripheral side of the inner tube 4 via upper and lower cylindrical seals 126A and 126B. The intermediate cylinder 126 forms therein an annular oil chamber E extending so as to surround the outer circumference of the inner cylinder 4 over the entire circumference. The annular oil chamber E is an oil chamber independent of the reservoir chamber A. The annular oil chamber E is always communicated with the rod-side oil chamber C through a radial oil hole 123 formed in the inner cylinder 4 . A connection port 126</b>C to which a cylindrical holder 135 of the damping force adjusting valve 132 is attached is provided on the lower end side of the intermediate tube 126 .

The bottom valve 127 is positioned on the lower end side of the inner cylinder 4 and provided between the bottom cap 3 and the inner cylinder 4 . The bottom valve 127 includes a valve body 128 that partitions (separates) the reservoir chamber A and the bottom-side oil chamber B between the bottom cap 3 and the inner cylinder 4 , and a reduction-side valve provided on the lower surface side of the valve body 128 . It is composed of a disk valve 129 and an extension side check valve 130 provided on the upper surface side of the valve body 128 . The valve body 128 is formed with oil passages 128A and 128B that allow the reservoir chamber A and the bottom-side oil chamber B to communicate with each other in the circumferential direction.

The contraction-side disc valve 129 opens when the pressure in the bottom-side oil chamber B exceeds the relief set pressure when the piston 6 slides downward in the contraction stroke of the piston rod 11, and the pressure at this time is is relieved to the reservoir chamber A side through each oil passage 128A. The relief setting pressure is set to a pressure higher than the valve opening pressure when the damping force adjustment device 131 is set to hard. The extension side check valve 130 opens when the piston 6 slides upward during the extension stroke of the piston rod 11, and closes otherwise. The check valve 130 allows the oil in the reservoir chamber A to flow through the oil passages 128B toward the bottom side oil chamber B, and prevents the oil from flowing in the opposite direction. The opening pressure of the check valve 130 is set, for example, to a pressure lower than the valve opening pressure when the damping force adjustment device 131 is set to Soft, and substantially generates no damping force.

Next, the damping force adjusting device 131 for variably adjusting the damping force generated by the shock absorber 1 will be described.

The damping force adjusting device 131 has its proximal end (left end in FIGS. 21 and 22) interposed between the reservoir chamber A and the annular oil chamber E, and its distal end (right end in FIGS. 21 and 22). side) is provided so as to protrude radially outward from the lower side of the outer cylinder 2 . The damping force adjusting device 131 controls the circulation of pressure oil (oil liquid) flowing from the annular oil chamber E in the intermediate cylinder 126 to the reservoir chamber A by means of the damping force adjusting valve 132, and the damping force generated at this time is variable. adjust to That is, the damping force adjustment valve 132 is variably controlled in generated damping force by adjusting the valve opening pressure of a variable set pressure valve 137, which will be described later, by a damping force variable actuator (solenoid 140). The damping force adjusting device 131 controls the flow of working fluid (oil liquid) caused by the sliding of the piston 6 inside the inner cylinder 4 to generate damping force.

Here, the damping force adjustment valve 132 has a valve case 134 provided so that its base end side is fixed around the opening 122 of the outer cylinder 2, its tip end side protrudes radially outward from the outer cylinder 2, and its base end side is in the middle. A cylindrical holder 135 is fixed to the connection port 126C of the cylinder 126 and has an annular flange portion 135A on the distal end side, and is disposed inside the valve case 134 with a gap. A valve member 136 abutting on the flange portion 135A, a variable set pressure valve 137 consisting of a main disc valve seated on and off the valve seat 136A of the valve member 136, and a back pressure chamber 138 for applying back pressure to the variable set pressure valve 137. , a pilot valve member 139 that variably sets the pilot pressure (back pressure) in the back pressure chamber 138 according to the energization (current value) of the solenoid 140 and adjusts the valve opening pressure of the set pressure variable valve 137. It is configured.

The set pressure variable valve 137 receives pressure in the direction of seating the valve member 136 on the valve seat 136A (that is, in the valve closing direction) from the pilot pressure (back pressure) from the back pressure chamber 138 . That is, the set pressure variable valve 137 receives the pressure on the inlet (annular oil chamber E) side of the cylindrical holder 135, and this pressure is combined with the pilot pressure (back pressure) on the back pressure chamber 138 side and the rigidity of the main disc valve. When the valve-opening pressure of the valve member 136 is exceeded, the valve member 136 is separated from the valve seat 136A and the valve is opened.

In this case, the set pressure variable valve 137 is set such that the valve opening pressure is variably set by adjusting the pilot pressure (back pressure) in the back pressure chamber 138 via the pilot valve member 139 . When the set pressure variable valve 137 leaves (opens) the valve seat 136A of the valve member 136, pressure oil from the annular oil chamber E (intermediate cylinder 126) side passes through the oil passage in the valve member 136 to reach the set pressure. It flows out of the variable valve 137 and flows from between the flange portion 135A of the cylindrical holder 135 and the valve case 134 to the reservoir chamber A side through the opening 122 of the outer cylinder 2 .

The solenoid 140 constitutes a damping force adjusting device 131 together with a damping force adjusting valve 132 and is used as a damping force variable actuator. As shown in FIG. 22, the solenoid 140 includes a cylindrical coil 141 that generates a magnetic force when energized from the outside, a stator core 142 that is arranged on the inner peripheral side of the coil 141, and an axial magnetic field on the inner peripheral side of the stator core 142. A plunger 143 as a movable iron core movably provided, an operating pin 145 integrally provided on the center side of the plunger 143 , and a cover member 146 covering the outer circumference of the coil 141 .

The cover member 146 constitutes a yoke made of a magnetic material and forms a magnetic circuit on the outer peripheral side of the coil 141 . The operating pin 145 extends through the plunger 143 in the axial direction (horizontal direction in FIG. 22), and the pilot valve member 139 of the damping force adjusting valve 132 is fixed to the left projecting end. That is, the operating pin 145 of the solenoid 140 is fitted inside the pilot valve member 139 . The pilot valve member 139 is displaced horizontally (leftward and rightward) integrally with the plunger 143 and the operating pin 145 .

Here, the plunger 143 of the solenoid 140 generates an axial thrust proportional to the energization (current value) of the coil 141 , and the pilot pressure (back pressure) in the back pressure chamber 138 increases the pressure of the pilot valve member 139 . It is set variably corresponding to the thrust of the plunger 143 by displacement. That is, the valve opening pressure of the set pressure variable valve 137 that opens against the pressure in the back pressure chamber 138 is adjusted by axially displacing the pilot valve member 139 in accordance with the energization of the solenoid 140. . In other words, the valve opening pressure of the set pressure variable valve 137 is increased or decreased by controlling the current applied to the coil 141 of the solenoid 140 by the controller to displace the pilot valve member 139 in the axial direction. Therefore, the damping force generated by the shock absorber 121 can be variably adjusted according to the valve opening pressure of the set pressure variable valve 137 which is proportional to the energization (current value) of the solenoid 140 .

Thus, in the ninth embodiment, the damper 121 is configured as a uniflow damping force adjustable hydraulic damper. That is, the shock absorber 121 has a damping force adjustment valve 132 whose opening/closing operation is adjusted by a solenoid 140 . A channel forming member 31 is provided in a channel (sub-passage 15 ) that communicates the bottom-side oil chamber B and the rod-side oil chamber C defined by the piston 6 . The restrictor passage 18 of the passage forming member 31 can adjust the required passage length by stacking a plurality of discs (passage discs 24) having spiral slits (through grooves 24A). In a variable damping force damper (adjustable damping force damper), it is necessary to set a large throttling characteristic with a hardware characteristic of high damping force. ) can be turned upside down for lamination, the required length of the flow path can be adjusted. That is, the damping force adjustable shock absorber, which is a semi-active damper, needs to narrow the constant orifice in order to secure a high damping force with hard damping force characteristics. On the other hand, in the ninth embodiment, by stacking the discs (24, 32, 33), a long spiral flow path (throttle passage 18) can be formed.

The ninth embodiment includes the damping force adjusting device 131 as described above and the passage forming unit 20 (flow passage forming member 31) similar to that of the second embodiment. There is no particular difference from the first to eighth embodiments. In particular, in the ninth embodiment, the passage forming unit 20 (flow passage forming member 31) is provided on the piston rod 11 of the uniflow damping force adjustable hydraulic shock absorber 121. As shown in FIG. The passage forming member 31 of the passage forming unit 20 is constructed by laminating a plurality of discs (passage discs 24) having spiral slits (through grooves 24A). Therefore, the spiral through groove 24A of the passage disk 24 allows the throttle passage 18 having a long passage length and a short axial length to be formed at low cost, thereby reducing the manufacturing cost.

Next, FIGS. 23 and 24 show a tenth embodiment. The feature of the tenth embodiment resides in that a frequency sensitive section acting on the back pressure chamber of the damping force adjustment valve of the damping force adjustment type shock absorber is provided. In the tenth embodiment, the same reference numerals are given to the same components as in the first to ninth embodiments described above, and the description thereof will be omitted.

The small diameter portion 11A of the piston rod 11 is provided with a passage forming unit 20 (flow passage forming member 31) similar to that of the second embodiment. The damping force adjustment valve 151 includes a valve case 134 , a cylindrical holder 135 , a valve member 136 , a variable set pressure valve 137 , a back pressure chamber 138 , a pilot valve member 139 , a pilot pin 152 and a pilot body 153 . and A pilot body 153 of the damping force adjustment valve 151 incorporates a frequency sensitive portion 154 . That is, in the tenth embodiment, the frequency sensitive section 154 is provided integrally with the damping force adjusting valve 151 . The frequency sensitive part 154 acts on the back pressure chamber 138 of the damping force adjustment valve 151 (set pressure variable valve 137).

Here, the pilot pin 152 sandwiches the set pressure variable valve 137 with the valve member 136 . The pilot body 153 includes a valve seat portion 153A on which the pilot valve member 139 is seated and disengaged, an annular plate portion 153B that bends from the valve seat portion 153A toward the pilot valve member 139 and widens radially outward, and an annular plate portion 153B. and a cylindrical portion 153C extending in the axial direction from the outer diameter side of the valve toward the set pressure variable valve 137 side. A free valve 155 is sandwiched between the pilot pin 152 and the pilot body 153 to reduce damping force against high-frequency vibrations.

The free valve 155 includes a plurality of (for example, three) discs 156 , a retainer 157 located on the outer diameter side of the discs 156 and provided on the side opposite to the back pressure chamber 138 , and a cylinder composed of the retainer 157 and the pilot body 153 . and an O-ring 158 that seals with the inner peripheral surface of the portion 153C and presses the disc 156 toward the back pressure chamber 138 side via the retainer 157 . The disk 156 is provided movably with respect to the pilot body 153 (cylindrical portion 153C) that forms the back pressure chamber 138 . The disk 156 partitions the interior of the cylindrical portion 153</b>C of the pilot body 153 into a back pressure chamber 138 and a variable chamber 159 . Disk 156 changes the volume of back pressure chamber 138 .

The disk 156 is provided with a communication orifice 161 that connects the oil passage 160 in the pilot pin 152 and the back pressure chamber 138 . The O-ring 158 is provided on the opposite side of the disk 156 to the back pressure chamber 138 . The O-ring 158 seals between the outer peripheral side of the disk 156 and the inner peripheral side of the cylindrical portion 153C of the pilot body 153 . In this case, the O-ring 158 functions as a spring member that biases the disk 156 and the back pressure chamber 138 by applying surface pressure to the inner circumference of the cylindrical portion 153C of the pilot body 153 and the outer circumference of the retainer 157. It also has a function as a sealing member for sealing. The free valve 155 is relatively displaced so as to move or stop within the cylindrical portion 153</b>C of the pilot body 153 according to the vibration frequency of the piston rod 11 and/or the inner cylinder 4 . Thereby, the free valve 155 operates as a frequency sensitive valve that adjusts the internal pressure of the back pressure chamber 138 according to the frequency.

That is, when a high-frequency fine amplitude is input, pressure is applied to the back pressure chamber 138 through the communication orifice 161 to bend the disk 156 and increase the volume of the back pressure chamber 138 . As a result, the pressure in the back pressure chamber 138 is lowered, the set pressure variable valve 137 is easily opened, and the damping force can be kept low. On the other hand, when a low-frequency large-amplitude input is applied to the back pressure chamber 138 through the communication orifice 161, the disk 156 is bent and the O-ring 158 is compressed. As a result, the force acting on the disk 156 increases and the disk 156 becomes less likely to flex, thereby stopping the pressure drop in the back pressure chamber 138 . As a result, the set pressure variable valve 137 becomes difficult to open, and the damping force maintains high characteristics.

In the tenth embodiment, a damping force adjusting valve 151 of a uniflow type damping force adjusting hydraulic shock absorber 121 is integrally provided with a frequency sensitive portion 154 . In this case, the frequency sensitive part 154 (free valve 155, which is a frequency sensitive valve) acts on both the extension stroke and the contraction stroke. In parallel with the oil passage 6A of the compression side disc valve 7 and the oil passage 6A of the expansion side disc valve 8, a spiral throttle passage 18 is provided by the passage forming member 31. As shown in FIG. Therefore, the effect of improving the damping force rise characteristic and the effect of improving the delay at high frequencies by the spiral throttle passage 18 can be obtained in both expansion and contraction.

The tenth embodiment includes the frequency sensitive portion 154 as described above and the passage forming unit 20 (flow passage forming member 31) similar to that of the second embodiment. There is no particular difference from the first to ninth embodiments. In particular, in the tenth embodiment, the frequency sensitive section 154 is provided integrally with the damping force adjusting valve 151 . The frequency sensitive portion 154 has a free valve 155 which is a movable member that can be moved by the oil (working fluid) in the rod-side oil chamber C. As shown in FIG. That is, the frequency sensitive part 154 biases the back pressure chamber 138 acting on the damping force adjustment valve 151, the free valve 155 (disk 156) acting on the pressure in the back pressure chamber 138, and the free valve (disk 156). and a spring member (O-ring 158). Therefore, the frequency sensitive section 154 can adjust the pressure of the back pressure chamber 138 acting on the damping force adjustment valve 151 according to the frequency. That is, in the tenth embodiment, the frequency sensitive section 154 can be provided integrally with the damping force adjusting valve 151 .

Next, FIGS. 25 to 27 show an eleventh embodiment. The feature of the eleventh embodiment resides in that the damping force adjustment valve incorporates the passage forming member (the damping force adjustment valve and the passage forming member are integrally provided). In the eleventh embodiment, the same reference numerals are given to the same constituent elements as in the first to tenth embodiments described above, and the description thereof will be omitted.

In the tenth embodiment described above, the frequency sensitive section 154 is provided integrally with the damping force adjustment valve 151 . On the other hand, in the eleventh embodiment, in addition to the frequency sensitive section 154 , the flow path forming member 171 is also provided integrally with the damping force adjusting valve 151 . In this case, the flow path forming member 171 is attached to the valve member 172 of the damping force adjusting valve 151 . Thus, the flow path forming member 171 is provided between the rod side oil chamber C and the reservoir chamber A, which are the other side chambers. That is, the flow path forming member 171 is provided in the oil path 173 that connects the rod-side oil chamber C and the reservoir chamber A. As shown in FIG. The oil passage 173 is a flow path between "an oil passage 174 in the cylindrical holder 135 connected to the annular oil chamber E (rod-side oil chamber C)" and "an oil passage 175 in the valve case 134 connected to the reservoir chamber A". is the road. The oil passage 173 is a passage through which the movement of the piston 6 causes oil (working fluid) to flow.

The valve member 172 of the damping force adjustment valve 151 has a cylindrical member 176 having a bottomed cylindrical shape as a first member and a disk-shaped cover member 178 as a second member. The flow path forming member 171 is provided between the tubular member 176 and the lid member 178 . That is, the valve member 172 (cylinder member 176 and lid member 178 ) corresponds to a storage member that stores the flow path forming member 171 . A bottom portion 179 of the cylindrical member 176 is provided with a center hole 179A and an introduction groove 179B extending radially outward from the center hole 179A. The cover member 178 has a center hole 178A to which the pilot pin 152 is connected, an annular valve seat 178B on which the variable set pressure valve 137 is seated and disengaged, and an annular recess 178D that forms an annular oil chamber 178C that is opened and closed by the variable set pressure valve 137. , and a through hole 178E opening to the annular recess 178D.

The flow path forming member 171 forms a communication path (first communication path) that becomes a spiral throttle passage 182 by stacking two discs 180 and 181 . That is, the flow passage forming member 171 has an introduction disk 180 and a passage disk 181 which are laminated to form a throttle passage 182 . The flow path forming member 171 , that is, the introduction disk 180 and the passage disk 181 are sandwiched between the tubular member 176 and the lid member 178 of the valve member 172 .

The introduction disk 180 has a through groove 180A extending in the circumferential direction and a closing portion 180B that closes the bottomed groove 181A of the passage disk 181 . That is, three through-grooves 180A extending in the circumferential direction are formed on the outer diameter side of the introduction disk 180, and the portion outside the through-grooves 180A serves as a closed portion 180B. On the other hand, the passage disk 181 has a spiral bottomed groove 181A extending in the circumferential direction. Specifically, the passage disc 181 is provided with a lateral groove 181B serving as an introduction port at a position corresponding to the through groove 180A of the introduction disc 180 . The passage disk 181 has a bottomed groove 181A that starts from the lateral groove 181B and spirals radially inward while extending in the circumferential direction from the lateral groove 181B.

In this case, as shown in FIG. 27, the bottomed groove 181A extends three and a half turns from an outer diameter side end portion 181C positioned radially outwardly of the passage disk 181 to an inner diameter side end portion 181D positioned most radially inwardly. That is, it extends in the circumferential direction (clockwise) by 1260°. A through hole 181E is provided at the inner diameter side end portion 181D, that is, at the center of the passage disk 181. As shown in FIG. The bottomed groove 181A of the passage disk 181 is blocked by the closing portion 180B of the introduction disk 180 to form a throttle passage 182 extending spirally. On the outer diameter side of the passage disk 181, projections 181F having a length approximately equal to the groove width of the through groove 180A of the introduction disk 180 are provided at a plurality of locations (three locations) spaced apart at equal intervals in the circumferential direction. It is As a result, a radial gap (an oil passage space) is formed between the cylindrical member 176 and the passage disc 181, and the oil that has passed through the through groove 180A of the introduction disc 180 flows through the lateral groove 181B of the passage disc 181. It is introduced into the bottom groove 181A. The oil that has passed through the through groove 180A is also introduced into the annular oil chamber 178C.

In the eleventh embodiment, the flow path forming member 171 as described above is incorporated in the damping force adjusting valve 151 (the flow path forming member 171 and the damping force adjusting valve 151 are integrated). is not particularly different from those according to the first to tenth embodiments described above. In particular, in the tenth embodiment, the channel forming member 171 can form the throttle channel 182 having a long channel length and a short axial length, so the channel forming member 171 is provided integrally with the damping force adjustment valve 151. Even so, it is possible to prevent the axial length of the damping force adjustment valve 151 from increasing.

In the above-described first embodiment, the case where the passage disk 24 has the spiral through groove 24A is described as an example. However, the present invention is not limited to this. For example, as in a modified example shown in FIG. 28, the disc 191 may have a through groove 192 extending radially or circumferentially in a meandering manner. Further, instead of the meandering through groove 192, a bottomed groove may be used. This also applies to the second to eleventh embodiments.

In the second embodiment, the first intermediate disk 32 as the second disk and the second intermediate disk 33 as the fourth disk have through holes 32A and 33A. However, the configuration is not limited to this, and the second disk and/or the fourth disk may have through grooves instead of through holes. This also applies to, for example, the fourth and fifth embodiments.

In the first to fifth embodiments and the seventh to tenth embodiments, the through groove is provided as the passage disk of the passage forming member that forms the throttle passage serving as the first communication passage. A case has been described as an example. However, not limited to this, for example, the through groove of the passage disk may be a bottomed groove. In this case, the introduction disk, closing disk, intermediate disk, etc. can be omitted as required.

In the eleventh embodiment, the case where the passage disk of the passage forming member forming the throttle passage serving as the first communication passage has a bottomed groove has been described as an example. However, without being limited to this, for example, the bottomed groove of the passage disk may be used as the through groove. In this case, an introduction disk, a closing disk, an intermediate disk, or the like can be provided as necessary to block the through groove.

In the first embodiment, the passage forming member is composed of two discs, and in the second embodiment, the passage forming member is composed of ten discs. However, the present invention is not limited to this, and the number of discs of the flow path forming member can be changed according to the required length of the restrictor flow path. This also applies to other embodiments.

In the first embodiment, the flow passage forming member 22 forming the throttle passage 18 serving as the first communication passage is positioned between the bottom side oil chamber B serving as one side chamber of the piston 6 and the rod side oil chamber C serving as the other side chamber. The case where it is configured to be provided in the example has been described. In the eleventh embodiment, the passage forming member 171 forming the throttle passage 182 serving as the first communication passage is provided between the rod-side oil chamber C serving as the other side chamber of the piston 6 and the reservoir chamber A serving as a reservoir. The case where it was set as the structure provided was mentioned as an example, and was demonstrated. However, the present invention is not limited to this, and for example, the flow path forming member forming the first communication path (restricted passage) may be arranged between the bottom-side oil chamber serving as one side chamber and the rod-side oil chamber serving as the other side chamber. It may be provided "between the rod-side oil chamber, which is the other side chamber, and the reservoir chamber, which is the reservoir." Further, for example, the flow path forming member may be provided "between the bottom side oil chamber serving as one side chamber and the reservoir chamber serving as the reservoir" by providing the flow path forming member in the valve body of the bottom valve. That is, the flow path forming member, which forms the first communication path by stacking disks, is the flow path in which the working fluid flows due to the movement of the piston, that is, between the one side chamber and the other side chamber, and between the one side chamber and the reservoir. and/or between the other side chamber and the reservoir.

In the eighth embodiment (FIG. 20), the case where the frequency sensitive part 101 acts on the back pressure chamber 103 of the extension side disk valve 102 which is the second valve of the piston 6 has been described as an example. However, the configuration is not limited to this, and the frequency sensitive section may be configured, for example, to act on the back pressure chamber of the pressure-side disk valve, which is the first valve of the piston, by providing it on the upper surface side of the piston 6 . Further, for example, the frequency sensitive section may be configured to act on both the back pressure chamber of the first valve and the back pressure chamber of the second valve. That is, the frequency sensitive section can be configured to act on the back pressure chamber of the first valve and/or the back pressure chamber of the second valve. The moving member (free valve, free piston) of the frequency sensitive part can be made movable by the working fluid of one side chamber and/or the other side chamber.

In the first embodiment, during the extension stroke of the piston rod 11, the extension side disk valve 8 on the lower side of the piston 6 gives resistance to the hydraulic fluid (working fluid) to generate a damping force, and the piston rod 11 is contracted. In the stroke, the case where the pressure-side disk valve 7 above the piston 6 exerts resistance to the hydraulic fluid (working fluid) to generate the damping force has been described as an example. However, without being limited to this, for example, the compression side disc valve on the upper side of the piston may be a check valve, and a disc valve provided on the bottom valve may generate a damping force in the contraction stroke of the piston rod 11 . This also applies to, for example, the second to eighth embodiments.

In the first embodiment, the dual-tube shock absorber 1 composed of the outer cylinder 2 and the inner cylinder 4 has been described as an example. However, the present invention is not limited to this, and may be applied to, for example, a shock absorber composed of a single-tube tubular member (cylinder). This also applies to, for example, the second to eighth embodiments.

Moreover, in each embodiment, the shock absorber attached to a motor vehicle was mentioned as an example and demonstrated as a typical example of a shock absorber. However, the present invention is not limited to this, and may be applied to, for example, shock absorbers attached to railway vehicles. In addition, it can be applied not only to vehicles such as automobiles and railroad vehicles, but also to various shock absorbers used in various machines, structures, buildings, etc. that serve as vibration sources.

Furthermore, each embodiment and modifications are examples, and it goes without saying that partial replacement or combination of configurations shown in different embodiments and modifications is possible.

As shock absorbers based on the embodiments described above, for example, the following modes are conceivable.

As a first aspect, the shock absorber comprises a cylinder in which a working fluid is sealed, a piston that divides the inside of the cylinder into one side chamber and the other side chamber, and a piston rod that is connected to the piston and extends to the outside of the cylinder. a flow path through which the working fluid flows due to movement of the piston; and a flow path having a plurality of plate-shaped discs which are provided in the flow path and are stacked to form a first communication path and which are not always flexurally deformed. and a forming member, the disc having a radially or circumferentially extending through or bottomed groove.

According to the first aspect, the flow path forming member is constructed by stacking discs having through grooves or bottomed grooves extending in the radial direction or the circumferential direction. Therefore, a communication passage (first communication passage) having a long passage length and a short axial length can be formed with a simple structure such as "stacking discs having through grooves or bottomed grooves extending in the radial direction or the circumferential direction". As a result, it is possible to inexpensively form a communication passage (throttle passage, choke passage) having a long passage length and a short axial length, thereby reducing the manufacturing cost of the shock absorber. Moreover, by adjusting the number of discs, the length of the communication path (passage length) can be easily adjusted (changed). Therefore, it is possible to easily set the damping force characteristic as desired (for example, set the rising characteristic of the damping force as desired), and from this point of view also, the manufacturing cost can be reduced. That is, by using a disc with a large outer diameter, it is possible to suppress an increase in the basic length (axial length) and obtain a large aperture characteristic with a small number of discs. Also, by alternately stacking discs of the same shape on the front and back, or by alternately stacking discs of two types, the length of the communication path that serves as the throttle can be adjusted. Therefore, it is possible to adjust the throttling characteristics according to many damping force characteristics with a small number of kinds of parts.

In a second aspect, the shock absorber includes a cylinder in which a working fluid is sealed, a piston that divides the inside of the cylinder into one side chamber and the other side chamber, and a piston rod that is connected to the piston and extends to the outside of the cylinder. a reservoir that compensates for the entry and exit of the piston rod; second and third communication passages that communicate the one side chamber and the other side chamber by movement of the piston; and the second and third communication passages. First and second valves provided respectively, and provided between the one side chamber and the other side chamber, between the one side chamber and the reservoir, and/or between the other side chamber and the reservoir, and laminated a flow path forming member having a plurality of plate-shaped disks formed by forming the first communication path, wherein the plurality of disks are spiral through grooves extending in the circumferential direction to a position where the start point exceeds the end point It includes at least one disc having bottomed grooves.

According to this second aspect, the flow path forming member is constructed by stacking a plurality of discs, including discs having spiral through grooves or bottomed grooves extending in the circumferential direction to a position where the starting point exceeds the end point. ing. Therefore, a communication passage (first communication passage) having a long passage length and a short axial length can be formed by a simple structure such as "stacking discs having spiral through grooves or bottomed grooves". As a result, it is possible to inexpensively form a communication passage (throttle passage, choke passage) having a long passage length and a short axial length, thereby reducing the manufacturing cost of the shock absorber. Moreover, by adjusting the number of discs, the length of the communication path (passage length) can be easily adjusted (changed). Therefore, it is possible to easily set the damping force characteristic as desired (for example, set the rising characteristic of the damping force as desired), and from this point of view also, the manufacturing cost can be reduced. That is, by using a disc with a large outer diameter, it is possible to suppress an increase in the basic length (axial length) and obtain a large aperture characteristic with a small number of discs. Also, by alternately stacking discs of the same shape on the front and back, or by alternately stacking discs of two types, the length of the communication path that serves as the throttle can be adjusted. Therefore, it is possible to adjust the throttling characteristics according to many damping force characteristics with a small number of kinds of parts.

As a third aspect, the shock absorber comprises a cylinder in which a working fluid is enclosed, a piston that divides the inside of the cylinder into one side chamber and the other side chamber, and a piston rod that is connected to the piston and extends to the outside of the cylinder. a flow path through which the working fluid flows due to the movement of the piston; a damping force adjustment valve whose opening and closing operation is adjusted by a solenoid; and a first disk provided in the flow path and having a through groove extending in the circumferential direction. and a closing portion that closes the through groove so that the working fluid supplied to one side of the through groove flows to the other side of the through groove, and a position corresponding to the other side of the through groove. a passage forming member having a second disk laminated on the first disk and having a through-hole or a through-groove provided in the first disk.

According to this third aspect, the flow path forming member has the first disk having the through groove extending in the circumferential direction, and the second disk having the blocking portion and the through hole or through groove. Therefore, with a simple structure such as "a first disc having a through groove extending in the circumferential direction and a second disc having a blocking portion and a through hole or a through groove are stacked", the passage length is long and the axial length is short. A communication path (first communication path) can be formed. As a result, it is possible to inexpensively form a communication passage (throttle passage, choke passage) having a long passage length and a short axial length, thereby reducing the manufacturing cost of the shock absorber. Moreover, by adjusting the number of discs, the length of the communication path (passage length) can be easily adjusted (changed). Therefore, it is possible to easily set the damping force characteristic as desired (for example, set the rising characteristic of the damping force as desired), and from this point of view also, the manufacturing cost can be reduced. That is, by using a disc with a large outer diameter, it is possible to suppress an increase in the basic length (axial length) and obtain a large aperture characteristic with a small number of discs. Also, by alternately stacking discs of the same shape on the front and back, or by alternately stacking discs of two types, the length of the communication path that serves as the throttle can be adjusted. Therefore, it is possible to adjust the throttling characteristics according to many damping force characteristics with a small number of kinds of parts.

As a fourth aspect, in any one of the first to third aspects, the piston includes a first member and a second member, and the flow path forming member includes the first member and the It is provided between the second member. According to this fourth aspect, the channel forming member and the piston can be provided integrally.

As a fifth aspect, in any one of the first to third aspects, the flow path forming member is provided inside the storage member, and the storage member is connected to the piston rod. According to this fifth aspect, the flow path forming member can be easily assembled to the piston rod together with the storage member.

As a sixth aspect, in any one of the first to third aspects, the flow path forming member is provided on the one side chamber side of the piston. According to the sixth aspect, for example, the flow path forming member can be arranged in the bottom side oil chamber inside the cylinder.

As a seventh aspect, in any one of the first to third aspects, the flow path forming member is provided on the other side chamber side of the piston. According to the seventh aspect, for example, the flow path forming member can be arranged in the rod-side oil chamber inside the cylinder.

As an eighth aspect, in any one of the first to seventh aspects, the piston rod has a frequency sensitive portion having a moving member that can be moved by the working fluid in the one side chamber and/or the other side chamber. and the flow path forming member. According to this eighth aspect, the flow path forming member can be assembled to the piston rod together with the frequency sensitive portion.

As a ninth aspect, in the first aspect, a reservoir that compensates for the entry and exit of the piston rod, a damping force adjustment valve whose opening and closing operation is adjusted by a solenoid, and a damping force adjustment valve that are provided integrally with the damping force adjustment valve. , a frequency sensitive part having a movable member movable by working fluid in the one side chamber and/or the other side chamber, between the one side chamber and the other side chamber, between the one side chamber and the reservoir, and/or and the flow path forming member provided between the other side chamber and the reservoir. According to the ninth aspect, the frequency sensitive section can be assembled to the damping force adjustment valve. Moreover, both the frequency sensitive portion and the flow path forming member can be assembled to the damping force adjustment valve as required.

As a tenth aspect, in the eighth aspect, the frequency sensitive section includes a case, a free piston as the moving member that can move in the case, and a spring member that biases the free piston. have. According to the tenth aspect, the case, the free piston, the frequency sensitive part having the spring member, and the flow path forming member can be assembled to the piston rod.

According to an eleventh aspect, in the second aspect, the piston rod is provided with a frequency sensitive portion having a moving member movable by the working fluid in the one side chamber and/or the other side chamber, and the frequency The sensitive part includes a back pressure chamber that acts on the first valve and/or the second valve of the piston, a free valve that acts on the pressure in the back pressure chamber as the moving member, and biases the free valve. and a spring member. According to the eleventh aspect, the frequency sensitive section can adjust the pressure in the back pressure chamber acting on the first valve and/or the second valve according to the frequency. That is, the frequency sensitive part can be provided integrally with the piston.

As a twelfth aspect, in the ninth aspect, the frequency sensitive section includes a back pressure chamber that acts on the damping force adjustment valve, a free valve that acts on the pressure in the back pressure chamber and serves as the moving member, a spring member that biases the free valve. According to the twelfth aspect, the frequency sensitive section can adjust the pressure in the back pressure chamber acting on the damping force adjustment valve according to the frequency. That is, the frequency sensitive section can be provided integrally with the damping force adjustment valve.

As a thirteenth aspect, in any one of the first to twelfth aspects, the flow path forming member includes a first disc having a through groove spirally extending in the circumferential direction, and one side of the through groove. A closing part that closes the through groove so that the working fluid supplied to one end flows to the other side end of the through groove, and a through hole or through groove that is provided at a position corresponding to the other side end of the through groove. a third disk obtained by reversing the front and back of the first disk; and a fourth disk having a through-hole or a through-groove provided at a position corresponding to one side end of the through-groove. According to the thirteenth aspect, it is possible to form a communication passage having a long passage length and a short axial length with a simple structure such as "stacking the first to fourth disks".

As a fourteenth aspect, in the first aspect or the second aspect, the flow path forming member includes a first bottomed groove extending spirally in the circumferential direction, and a A fifth disk having a first through hole provided, a second bottomed groove spirally extending in a direction opposite to the first bottomed groove of the fifth disk, and the second bottomed groove a sixth disk having a second through hole provided at an end thereof; According to the fourteenth aspect, a communication passage having a long passage length and a short axial length can be formed with a simple structure such as "stacking the fifth disc and the sixth disc."

1,121 shock absorber 2 outer cylinder 4 inner cylinder (cylinder)
6, 41 Piston 6A Oil passage (second communication passage)
6B oil passage (third communication passage)
7 Compression side disk valve (1st valve)
8, 102 Extension side disc valve (second valve)
11 piston rod 15 subpassage (flow path)
18, 182 throttle passage (first communication passage)
22, 31, 48, 66, 71, 82, 97, 171 flow path forming member 23, 70 introduction disk (disk, second disk)
23B, 70B Through groove 23C, 70C Closing portion 24, 49, 67, 98 Passage disk (disk, first disk, third disk)
24A, 49B, 67B through groove 24B, 49C, 67C inner diameter side end (one side or other side, one side end or other side end)
24C, 49D, 67D outer diameter side end (other side or one side, other side end or one side end)
25, 34 storage member 32 first intermediate disc (second disc or fourth disc)
32A Through hole 32B Closing portion 33 Second intermediate disk (fourth disk or second disk)
33A Through hole 33B Closing portion 42 Cylindrical member (first member)
44 lid member (second member)
50, 68 first blocking disk (second disk or fourth disk)
50B, 68B Through hole 50C, 68C Closing portion 51, 69 Second closing disk (fourth disk or second disk)
51B, 69B Through hole 51C, 69C Closing portion 83 First passage disk 83A First bottomed groove 83B Inner diameter side end (end)
83C outer diameter side end (end)
83D first through hole 84 second passage disk 84A second bottomed groove 84B inner diameter side end (end)
84C outer diameter side end (end)
84D second through hole 91, 101, 154 frequency sensitive part 92 case 93 free piston 94, 95, 158 O-ring (spring member)
103 Back pressure chamber 106, 155 Free valve 106A Disc valve 106B Elastic seal member (spring member)
132, 151 damping force adjustment valve 137 set pressure variable valve 138 back pressure chamber 140 solenoid 180 introduction disk 180A through groove 180B closing portion 181 passage disk 181A bottomed groove 181E through hole 191 disk 192 through groove A reservoir chamber B bottom side oil chamber (one side room)
C Rod side oil chamber (other side chamber)

Claims (14)

a cylinder in which the working fluid is sealed;
a piston that divides the inside of the cylinder into one side chamber and the other side chamber;
a piston rod connected to the piston and extending to the outside of the cylinder;
a flow path through which the working fluid flows due to movement of the piston;
a flow path forming member provided in the flow path and having a plurality of plate-shaped discs that are stacked to form a first communication path and that do not undergo bending deformation at all times;
The disk is a shock absorber having a radially or circumferentially extending through groove or bottomed groove. a cylinder in which the working fluid is sealed;
a piston that divides the inside of the cylinder into one side chamber and the other side chamber;
a piston rod connected to the piston and extending to the outside of the cylinder;
a reservoir that compensates for the entry and exit of said piston rod;
second and third communication passages communicating the one side chamber and the other side chamber by movement of the piston;
first and second valves respectively provided in the second and third communication passages;
A plurality of devices provided between the one side chamber and the other side chamber, between the one side chamber and the reservoir, and/or between the other side chamber and the reservoir, and stacked to form a first communication passage a flow path forming member having a plate-like disk of
The plurality of discs includes at least one disc having a spiral through groove or bottomed groove circumferentially extending to a position where the start point exceeds the end point. a cylinder in which the working fluid is sealed;
a piston that divides the inside of the cylinder into one side chamber and the other side chamber;
a piston rod connected to the piston and extending to the outside of the cylinder;
a flow path through which the working fluid flows due to movement of the piston;
a damping force adjustment valve whose opening and closing operation is adjusted by a solenoid;
a first disk provided in the flow path and having a through groove extending in the circumferential direction; a passage forming member having a second disk laminated on the first disk, the closing portion closing the through groove and a through hole or through groove provided at a position corresponding to the other side of the through groove; buffer provided. the piston has a first member and a second member;
The shock absorber according to any one of claims 1 to 3, wherein the flow path forming member is provided between the first member and the second member. The flow path forming member is provided inside the storage member,
4. The shock absorber according to claim 1, wherein said housing member is connected to said piston rod. 4. The shock absorber according to any one of claims 1 to 3, wherein the flow path forming member is provided on the one side chamber side of the piston. 4. The shock absorber according to any one of claims 1 to 3, wherein the flow path forming member is provided on the other side chamber side of the piston. 8. The piston rod according to any one of claims 1 to 7, wherein a frequency sensitive portion having a movable member movable by working fluid in the one side chamber and/or the other side chamber, and the flow path forming member are provided. buffer. a reservoir that compensates for the entry and exit of said piston rod;
a damping force adjustment valve whose opening and closing operation is adjusted by a solenoid;
a frequency sensitive part provided integrally with the damping force adjusting valve and having a moving member movable by working fluid in the one side chamber and/or the other side chamber;
2. The passage forming member provided between the one side chamber and the other side chamber, between the one side chamber and the reservoir, and/or between the other side chamber and the reservoir. buffer. The frequency sensitive part is
a case;
a free piston serving as the moving member capable of moving within the case;
and a spring member biasing the free piston. The piston rod is provided with a frequency sensitive part having a moving member that can be moved by the working fluid in the one side chamber and/or the other side chamber,
The frequency sensitive part is
a back pressure chamber acting on the first valve and/or the second valve of the piston;
a free valve serving as the moving member acting on the pressure in the back pressure chamber;
and a spring member biasing the free valve. The frequency sensitive part is
a back pressure chamber acting on the damping force adjustment valve;
a free valve serving as the moving member acting on the pressure in the back pressure chamber;
and a spring member biasing the free valve. The flow path forming member is
a first disk having a through groove spirally extending in the circumferential direction;
a closing portion for closing the through groove so that the working fluid supplied to one side end of the through groove flows to the other side end of the through groove; and a closing portion provided at a position corresponding to the other side end of the through groove. a second disk having through holes or through grooves;
a third disk obtained by reversing the front and back of the first disk;
a closing part that closes the through groove so that the working fluid supplied to the other side end of the through groove of the third disk flows to the one side end of the through groove, and a closing part that corresponds to the one side end of the through groove 13. A shock absorber according to any one of claims 1 to 12, comprising a fourth disk having through-holes or through-grooves provided at positions. The flow path forming member is
a fifth disk having a first bottomed groove extending spirally in the circumferential direction and a first through hole provided at an end of the first bottomed groove;
A sixth groove having a second bottomed groove spirally extending in a direction opposite to the first bottomed groove of the fifth disk and a second through hole provided at an end of the second bottomed groove. 3. A buffer according to claim 1 or 2, comprising a disc.

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