WO2018021125A1

WO2018021125A1 - Shock absorber

Info

Publication number: WO2018021125A1
Application number: PCT/JP2017/026188
Authority: WO
Inventors: 定知松村
Original assignee: 日立オートモティブシステムズ株式会社
Priority date: 2016-07-26
Filing date: 2017-07-20
Publication date: 2018-02-01
Also published as: JP2019163769A

Abstract

Provided is a shock absorber with which variation in the generated damping force can be suppressed. This shock absorber 1 has an inner cylinder 6, a piston 11, and damping force generation mechanisms 15 and 16. The piston 11 has a piston main body 12, and a retainer 13 assembled in abutment with the piston main body 12. The piston main body 12 has an annular first seat part 12E, and the retainer 13 has an annular second seat part 13C that is connected in abutment with the first seat part 12E. The second seat part 13C has an outer circumferential tapered part 13C1 and an inner circumferential tapered part 13C2 that protrude in a tapered shape toward the first seat part 12E prior to assembly of the piston main body 12 and the retainer 13, and the inclination of the inner circumferential tapered part 13C2 is more gradual than the inclination of the outer circumferential tapered part 13C1.

Description

Shock absorber

The present invention relates to a shock absorber that is mounted on a vehicle such as a four-wheeled vehicle and is suitably used for buffering vibration of the vehicle.

Generally, in a vehicle such as a four-wheeled vehicle, a hydraulic shock absorber is provided between each wheel (axle side) and the vehicle body so as to buffer the vibration of the vehicle (see, for example, Patent Document 1). This type of hydraulic shock absorber according to the prior art suppresses the flow of the working fluid caused by the sliding of the cylinder in which the working fluid is sealed, the piston slidably fitted in the cylinder, and the piston in the cylinder. And a damping force generation mechanism for generating a damping force.

JP-A-2-271123

In the hydraulic shock absorber according to Patent Document 1, a piston is constituted by a piston main body (first piston body) and a retainer (second piston body) attached to the piston main body. However, when the retainer is attached to the piston body, there is a problem in that a part of the damping force generating mechanism is deformed as the retainer is deformed, and the generated damping force varies.

An object of the present invention is to provide a shock absorber capable of suppressing variations in generated damping force.

A shock absorber according to an 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 a first chamber and a second chamber, and a damping that is provided in the piston and generates a damping force. In the shock absorber provided with a force generation mechanism, the piston has a first piston body and a second piston body assembled to the first piston body in an abutting state, and the first piston body comprises: An annular first seat portion is provided on the outer peripheral side of the opening of the first passage for communicating the first chamber and the second chamber, and the second piston body communicates the first chamber and the second chamber. An annular second sheet portion that is engaged with and coupled to the first sheet portion is disposed on an outer peripheral side of the opening of the second passage, and the damping force generation mechanism is configured to be the first chamber of the first piston body. Side and the second chamber side of the second piston body, The two-sheet portion has an outer peripheral taper portion and an inner peripheral taper portion that project in a tapered shape toward the first sheet portion side in a state before the first piston body and the second piston body are assembled. The inclination of the inner peripheral side taper portion is characterized by being gentler than the inclination of the outer peripheral side taper portion.

A shock absorber according to an 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 a first chamber and a second chamber, and a damping force that is provided in the piston. In the shock absorber provided with a damping force generating mechanism, the piston has a first piston body and a second piston body assembled in an abutting state with the first piston body, and the first piston body. Has an annular first seat part on the outer peripheral side of the opening of the first passage communicating with the first chamber and the second chamber, and the second piston body communicates with the first chamber and the second chamber An annular second sheet portion that is engaged with and coupled to the first sheet portion is disposed on an outer peripheral side of the opening of the second passage, and the damping force generation mechanism is configured to be the first chamber of the first piston body. On the side and the second chamber side of the second piston body, respectively, The second sheet portion protrudes toward the first sheet portion in a state before the first piston body and the second piston body are assembled, and is a protrusion that is plastically deformed while being coupled to the first sheet portion. It has the part.

According to one embodiment of the present invention, variation in generated damping force can be suppressed.

It is a longitudinal section showing a buffer by a 1st embodiment. It is sectional drawing which expands and shows the piston etc. in FIG. It is sectional drawing which shows the retainer in FIG. 2 alone. FIG. 4 is an essential part cross-sectional view showing an enlarged IV part in FIG. 3. It is sectional drawing which shows the state at the time of attaching a retainer to a piston main body. It is sectional drawing which shows the state which attached the retainer to the piston main body. It is principal part sectional drawing which expands and shows the retainer by 2nd Embodiment. It is principal part sectional drawing which expands and shows the retainer by 3rd Embodiment. It is principal part sectional drawing which expands and shows the retainer by 4th Embodiment. It is principal part sectional drawing which expands and shows the retainer by 5th Embodiment.

Hereinafter, an example in which the shock absorber according to the embodiment of the present invention is applied to a hydraulic shock absorber for a vehicle will be described in detail with reference to the accompanying drawings.

Here, FIG. 1 to FIG. 6 show the first embodiment. In FIG. 1, a hydraulic shock absorber 1 includes a cylindrical outer cylinder 2, an inner cylinder 6, a piston rod 8, a piston 11, an extension side damping force generation mechanism 15, a contraction side damping force generation mechanism 16 and the like that form an outer shell. Have.

The outer cylinder 2 of the hydraulic shock absorber 1 has a closed end in which a base end side (lower end in FIG. 1) as one end side is closed by a bottom cap 3, and a distal end side (upper end in FIG. 1) as the other end side. ) Is the open end. On the opening end (tip) side of the outer cylinder 2, a caulking portion 2 A formed by bending inward in the radial direction is provided. The caulking portion 2 A covers the lid body 4 that closes the opening end side of the outer cylinder 2. Holding in the retaining state.

The lid 4 made of an annular disk is fixed by a caulking portion 2A of the outer cylinder 2 with its outer peripheral side in contact with a rod guide 9 to be described later in order to close the open end (tip) side of the outer cylinder 2. Yes. A rod seal 5 made of an elastic material is provided on the inner peripheral side of the lid body 4, and the rod seal 5 seals between a piston rod 8 (described later) and the lid body 4.

The inner cylinder 6 as a cylinder is provided coaxially in the outer cylinder 2, and one end (base end) side of the inner cylinder 6 is fitted and fixed to the bottom cap 3 side via the bottom valve 7. Yes. A rod guide 9 (described later) is fitted and attached to the inner periphery of the opening end side that is the other end (tip) side of the inner cylinder 6. The inner cylinder 6 is filled with a working fluid containing oil. The working fluid is not limited to oil liquid (oil), and for example, water mixed with additives can be used.

An annular reservoir chamber A is formed between the inner cylinder 6 and the outer cylinder 2, and gas is sealed in the reservoir chamber A together with the oil liquid. This gas may be atmospheric pressure air or a compressed gas such as nitrogen gas. The gas in the reservoir chamber A is compressed to compensate for the entry volume of the piston rod 8 when the piston rod 8 is contracted (contraction stroke).

The piston rod 8 has a proximal end inserted into the inner cylinder 6 and a distal end projecting out of the inner cylinder 6 via a rod guide 9 and a lid 4 which will be described later. On the proximal end side of the piston rod 8, a small-diameter rod portion 8A to which a later-described piston 11, an expansion-side damping force generation mechanism 15 and a contraction-side damping force generation mechanism 16 are attached, and an end portion of the small-diameter rod portion 8A are formed. A male screw portion 8B to which a nut 17 described later is screwed is provided.

The rod guide 9 is fitted on the opening end side of the outer cylinder 2 and is also fixedly provided on the opening end side of the inner cylinder 6. As shown in FIG. 1, the rod guide 9 includes a large-diameter portion 9A that is located on the upper side and is fitted on the inner peripheral side of the outer cylinder 2, and an inner cylinder that is located on the lower side of the large-diameter portion 9A. 6 is formed in a stepped cylindrical shape by a small-diameter portion 9 B inserted and fitted on the inner peripheral side. A guide portion 10 that guides the piston rod 8 so as to be slidable in the axial direction is provided on the inner peripheral side of the small diameter portion 9B.

Further, the large diameter portion 9A of the rod guide 9 is provided with an annular oil reservoir chamber 9C on the upper surface side of the large diameter portion 9A facing the lid body 4. The oil reservoir chamber 9C includes the rod seal 5 and the piston rod. It is formed as an annular space that surrounds 8 from the outside in the radial direction. The oil sump chamber 9 C is disposed when the oil liquid in the rod side chamber C (or gas mixed in the oil liquid) leaks through a slight gap between the piston rod 8 and the guide portion 10. It provides a space for temporarily storing leaked oil.

Further, the large-diameter portion 9A of the rod guide 9 is provided with a communication passage 9D that always communicates with the reservoir chamber A on the outer cylinder 2 side, and this communication passage 9D is connected to the oil liquid ( Gas is contained) to the reservoir chamber A on the outer cylinder 2 side.

The piston 11 is provided in the small-diameter rod portion 8A of the piston rod 8, and is slidably fitted into the inner cylinder 6. The piston 11 includes a piston main body 12 positioned on the rod guide 9 side, a retainer 13 positioned on the bottom valve 7 side, and a seal member 14. The piston 11 defines the inside of the inner cylinder 6 in two chambers, a lower bottom chamber B and an upper rod chamber C. Here, the rod side chamber C constitutes a first chamber, and the bottom side chamber B constitutes a second chamber.

The piston main body 12 constitutes a first piston body, and is provided on the outer peripheral side of the small diameter rod portion 8A together with a retainer 13 as a second piston body. For example, the piston body 12 is formed in a substantially cylindrical shape from a sintered metal. On the inner peripheral side of the piston body 12, a rod mounting hole 12A through which the small diameter rod portion 8A of the piston rod 8 is inserted is formed. Further, the piston body 12 is provided with a plurality of extension-side communication passages 12 B that are formed in the axial direction of the piston body 12 so as to be located on the radially outer side of the rod mounting hole 12 A. Further, the piston body 12 is provided with a plurality of contraction-side communication passages 12 C that are located on the outer peripheral side of the piston body 12 with respect to the respective extension-side communication passages 12 B and are drilled in the axial direction of the piston body 12. .

Each extension side communication passage 12B constitutes a first passage for communicating the bottom side chamber B and the rod side chamber C via an extension side communication passage 13B of the retainer 13 described later. Each extension-side communication path 12B generates an extension-side damping force by a disk valve 15A of an extension-side damping force generation mechanism 15 (described later) when an oil liquid flows through each extension-side communication path 12B. . Further, each contraction side communication passage 12 C allows the bottom side chamber B and the rod side chamber C to communicate with each other without using the retainer 13. Each contraction-side communication passage 12C generates a reduction-side damping force by a disk valve 16A of a contraction-side damping force generation mechanism 16 (described later) when an oil liquid flows through each compression-side communication passage 12C. .

Here, on one side (rod guide 9 side) of the piston main body 12, on the outer peripheral side of the extension side communication passage 12 B, one side on which a disk valve 16 A of a contraction side damping force generation mechanism 16 to be described later is seated. An annular valve seat 12D is provided. Further, an annular first seat portion 12E which is located on the other side (retainer 13 side) of the piston body 12 and is engaged with the second seat portion 13C of the retainer 13 on the outer peripheral side of the opening of the extension side communication passage 12B. Is provided over the entire circumference of the piston body 12.

The retainer 13 is positioned as the second piston body on the other side of the piston main body 12 and assembled with the piston main body 12 in an abutting state. On the inner peripheral side of the retainer 13, a rod mounting hole 13A through which the small diameter rod portion 8A of the piston rod 8 is inserted is formed. In addition, the retainer 13 is provided with a plurality of extension-side communication passages 13B that are formed in the axial direction of the retainer 13 so as to be located on the radially outer side of the rod mounting hole 13A. The extension side communication passage 13B constitutes a second passage that connects the bottom side chamber B and the rod side chamber C via the extension side communication passage 12B. In addition, the first seat portion 12E of the piston body 12 abuts and is coupled to the outer peripheral side of the opening of the extension side communication passage 13B, which is located on one side of the retainer 13 (piston body 12 side). A second sheet portion 13 C is provided over the entire circumference of the retainer 13. Further, a disk valve 15A of an extension-side damping force generation mechanism 15, which will be described later, is separated from the outer peripheral side of the extension-side communication passage 13B, which is located on the bottom chamber B side (the opposite side of the second seat portion 13C) of the retainer 13. Other side

annular valve seats

13D and 13E to be seated are provided. The other-side

annular valve seats

13D and 13E serve as seating surfaces on which a disk valve 15A, which will be described later, is placed so as to be separated.

The retainer 13 is formed to be slightly smaller than the radial dimension of the piston body 12 using sintered metal. The retainer 13 increases the radial dimension of the annular valve seat portion on which the disk valve 15A of the extension-side damping force generating mechanism 15 is separated and seated so that the outer diameter dimension of the disk valve 15A can be increased. As a result, the disk valve 15A is easily elastically deformed, and the generated damping force can be smoothly changed according to the speed change when the piston 11 is displaced in the axial direction.

Here, the second seat portion 13C is an annular projection that is located on the piston body 12 side of the retainer 13 and is provided on the outer peripheral side of the retainer 13 with respect to each extension side communication passage 13B. As shown in FIG. 4, the second sheet portion 13 C includes an outer peripheral taper portion 13 C 1 located on the radially outer side of the retainer 13, and an inner peripheral side located on the radially inner side of the retainer 13 with respect to the outer peripheral side taper portion 13 C 1. It is comprised by the taper part 13C2. Specifically, the second seat portion 13C is in a state before assembling the piston body 12 and the retainer 13 from the one side outer periphery of the second seat portion 13C toward the first seat portion 12E side of the piston body 12. It protrudes in a tapered shape. In this case, the inclination of the inner peripheral side taper portion 13C2 is set to be gentler than the inclination of the outer peripheral side taper portion 13C1. Here, “inclination” means an inclination with respect to the radial direction surface (horizontal plane) of the retainer 13.

The axial dimension between the apex h1 of the second seat portion 13C (inner peripheral taper portion 13C2) and the outer peripheral end h2 of the second seat portion 13C is the outer peripheral side when the piston body 12 and the retainer 13 are assembled. This is the closing allowance S1. Further, the axial dimension between the bottom h3 of the inner peripheral side taper portion 13C2 and the outer peripheral end h2 of the second seat portion 13C is the inner peripheral side allowance S2 when the piston body 12 and the retainer 13 are assembled. It is.

The seal member 14 is provided by being fitted to the outer peripheral surface of the piston body 12. The seal member 14 is formed in a cylindrical shape using, for example, a fluorine resin material. The seal member 14 seals the space between the rod side chamber C and the bottom side chamber B in a liquid-tight manner. Further, the seal member 14 suppresses frictional resistance when the piston body 12 slides in the inner cylinder 6.

The extension side damping force generation mechanism 15 is provided on the other end surface (bottom side chamber B side) of the retainer 13. The extension-side damping force generation mechanism 15 includes a plurality of disk valves 15A and a regulation plate 15B that is positioned closer to the bottom valve 7 than the disk valves 15A. The plurality of disc valves 15A are separated from the other

annular valve seats

13D and 13E of the retainer 13, and when the piston rod 8 slides and displaces in the extension direction, the oil liquid that flows through the extension

side communication passages

12B and 13B. A predetermined damping force is generated by applying a resistance force to. The regulating plate 15B regulates the opening degree of the disc valve 15A when the disc valve 15A is opened.

The contraction-side damping force generating mechanism 16 is provided on one end face (rod-side chamber C side) of the piston body 12. The compression-side damping force generating mechanism 16 includes a disc valve 16A, a plate spring 16B that urges the disc valve 16A downward (on the piston body 12 side), and an upper side (on the rod guide 9 side) than the plate spring 16B. And a restricting plate 16C located at the position. When the piston rod 8 slides and displaces in the shrinking direction, the disc valve 16A is seated on and away from the one-side annular valve seat 12D of the piston body 12 and gives resistance to the oil flowing through the contraction side communication passage 12C. To generate a predetermined damping force. The regulating plate 16C regulates the opening degree of the disc valve 16A when the disc valve 16A is opened. In this case, oil passages 16A1, 16B1, and 16C1 that allow fluid to flow into the respective extension

side communication passages

12B and 13B when the piston rod 8 extends are respectively provided on the disc valve 16A, the leaf spring 16B, and the restriction plate 16C. Is provided.

The nut 17 is provided by being screwed to the male thread portion 8B of the piston rod 8. The nut 17 assembles the piston main body 12 and the retainer 13 to the small-diameter rod portion 8A of the piston rod 8, and has an extension side damping force generation mechanism 15 and a contraction side damping force generation mechanism 16 on the upper and lower surfaces of the piston 11. It is detachably fixed.

Next, a method of assembling the piston 11, the expansion side damping force generation mechanism 15, and the contraction side damping force generation mechanism 16 to the small diameter rod portion 8A of the piston rod 8 will be described.

First, the contraction-side damping force generation mechanism 16, the piston main body 12, the retainer 13, and the extension-side damping force generation mechanism 15 are inserted into the small-diameter rod portion 8A of the piston rod 8 in this order. Subsequently, the nut 17 is screwed onto the male thread portion 8B of the piston rod 8, and the piston 11, the expansion side damping force generation mechanism 15 and the contraction side damping force generation mechanism 16 are assembled to the small diameter rod portion 8A of the piston rod 8.

In this case, when the piston body 12 and the retainer 13 are assembled, the second sheet portion 13C of the retainer 13 is strongly abutted against the first sheet portion 12E of the piston body 12, and the extension-side communication path 13B of the retainer 13 and A space is formed between the piston body 12 and the expansion side communication passage 12B. Specifically, the inner peripheral side taper portion 13C2 of the second sheet portion 13C abuts on the first sheet portion 12E so as to be in close contact with the first seat portion 12E, and seals between the extension side communication passage 13B and the extension side communication passage 12B. And prevent oil leakage.

At this time, the outer peripheral side taper portion 13C1 contacts the first sheet portion 12E with the outer peripheral side allowance S1 and the inner peripheral side taper portion 13C2 contacts the first sheet portion 12E with the inner peripheral side allowance S2. Specifically, the inner circumferential taper portion 13C2 is compressed and plastically deformed by the first sheet portion 12E, thereby generating a radially outward pressing force F on the second sheet portion 13C (see FIG. 6). Accordingly, the second sheet portion 13C is plastically deformed so that the inner peripheral side taper portion 13C2 is displaced radially outwardly by the pressing force F toward the outer peripheral side taper portion 13C1 and falls to the outer peripheral side. In this case, since the second seat portion 13C is plastically deformed, an external force when the piston body 12 and the retainer 13 are coupled in the upward and downward directions can be partially absorbed, and the other annular valve of the retainer 13 can be absorbed. It is possible to suppress the deformation force from reaching the

seats

13D and 13E.

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

The hydraulic shock absorber 1 has the piston rod 8 attached to the front end side of the vehicle body and the base end side of the outer cylinder 2 attached to the axle (not shown). As a result, when vibration is generated during driving of the automobile, the expansion side damping force generation mechanism 15 and the compression side damping force are generated when the piston rod 8 extends and contracts in the axial direction from the outer cylinder 2 and the inner cylinder 6. The mechanism 16 generates damping forces on the expansion side and the reduction side, and can buffer the vibrations in the upward and downward directions of the vehicle.

That is, when the piston rod 8 is in the extension stroke, the inside of the rod side chamber C is in a high pressure state, so that the oil liquid in the rod side chamber C flows through the oil passages 16A1, 16B1, 16C1, and the extension side communication passage of the piston body 12. 12B, the expansion side communication passage 13B of the retainer 13 and the expansion side damping force generation mechanism 15 are circulated into the bottom side chamber B, and the expansion side damping force is generated. Thereby, it can buffer so that extension operation of piston rod 8 may be suppressed. In the extension stroke of the piston rod 8, an amount of oil corresponding to the advancing volume of the piston rod 8 that has advanced from the inner cylinder 6 flows into the bottom chamber B from the reservoir chamber A through the bottom valve 7. .

Here, since the inside of the rod side chamber C is in a high pressure state when the piston rod 8 is in the extension stroke, the oil liquid in the rod side chamber C passes through, for example, a slight gap between the piston rod 8 and the guide portion 10. May leak into the oil sump chamber 9C. Further, when leaked oil increases in the oil sump chamber 9C, the overflowing oil liquid is connected to the communication path of the rod guide 9 via a check valve (not shown) provided between the lid 4 and the rod guide 9. It is guided to the 9D side and gradually recirculates into the reservoir chamber A.

On the other hand, in the reduction stroke of the piston rod 8, the pressure in the bottom side chamber B located below the piston 11 is higher than that in the rod side chamber C, so that the oil in the bottom side chamber B is in the contraction side communication path 12 C of the piston body 12. Then, it flows into the rod side chamber C via the contraction side damping force generation mechanism 16 and generates a reduction side damping force. Then, an amount of oil corresponding to the integral volume of the piston rod 8 entering the inner cylinder 6 flows into the reservoir chamber A from the bottom side chamber B through the bottom valve 7, and the reservoir chamber A contains internal gas. Is compressed to absorb the entrance volume of the piston rod 8.

Thus, according to the first embodiment, the retainer 13 and the first seat portion 12E of the piston body 12 are in contact with the first seat portion 12E of the piston main body 12 on the outer peripheral side of the opening of the extension side communication passage 13B that communicates the rod side chamber C and the bottom side chamber B. It has the cyclic | annular 2nd sheet | seat part 13C couple | bonded together. In this case, the second seat portion 13C includes an outer peripheral taper portion 13C1 and an inner peripheral taper portion 13C2 that project in a tapered shape toward the first seat portion 12E before the piston main body 12 and the retainer 13 are assembled. And the inner taper portion 13C2 has a gentler slope than the outer taper portion 13C1.

As a result, when the piston body 12 and the retainer 13 are assembled, the inner circumferential side taper portion 13C2 is compressed and deformed by the first seat portion 12E, so that the second seat portion 13C is displaced radially outward and the outer circumferential side. It can be transformed to fall down. That is, the second seat portion 13C is deformed and absorbs the upward and downward coupling force (external force) between the piston body 12 and the retainer 13, thereby causing the other

annular valve seats

13D and 13E to be affected by the external force. It is possible to suppress the influence of deformation. As a result, it is possible to prevent the disk valve 15A of the extension-side damping force generation mechanism 15 that is attached to and detached from the other-side

annular valve seats

13D and 13E from being deformed, and to suppress variations in the generated damping force.

The retainer 13 has other

annular valve seats

13D and 13E for disposing the disk valve 15A of the extension side damping force generating mechanism 15 on the bottom side chamber B side opposite to the second seat portion 13C. Yes. The second seat portion 13C is configured to suppress deformation of the other

annular valve seats

13D and 13E by deformation of the inner peripheral side taper portion 13C2 when the piston body 12 and the retainer 13 are assembled (when coupled). . Thereby, the deformation amount of the other-side

annular valve seats

13D and 13E can be reduced while ensuring the oil tightness between the piston body 12 and the retainer 13. As a result, it is possible to prevent the disc valve 15A of the extension side damping force generation mechanism 15 from being deformed, and to suppress variations in the generated damping force.

Furthermore, since the hydraulic shock absorber 1 can be manufactured by a manufacturing process equivalent to the conventional one, it is possible to suppress an increase in manufacturing cost.

Next, FIG. 7 shows a second embodiment of the present invention. The feature of the second embodiment is that a flat portion is provided in the second sheet portion of the retainer. Note that in the second embodiment, the same components as those in the first embodiment described above are denoted by the same reference numerals, and description thereof is omitted.

As in the retainer 13 described in the first embodiment, the retainer 21 includes a rod mounting hole (not shown), a plurality of extension side communication passages 21A, a second seat portion 21B, and the other side annular valve seat. (Not shown).

Here, as shown in FIG. 7, the second sheet portion 21 B includes an outer peripheral taper portion 21 B 1, an inner peripheral taper portion 21 B 2, and a flat portion 21 B 3. Specifically, the second seat portion 21B is in a state before assembling the piston body 12 and the retainer 21 from the one side outer periphery of the second seat portion 21B toward the first seat portion 12E side of the piston body 12. It protrudes in a tapered shape. In this case, the inclination of the inner peripheral side taper portion 21B2 is set to be gentler than the inclination of the outer peripheral side taper portion 21B1.

Also, a flat portion 21B3 that is flat with respect to the radial surface (horizontal plane) of the retainer 21 is provided between the outer peripheral taper portion 21B1 and the inner peripheral taper portion 21B2. The flat portion 21B3 collides with the first seat portion 12E of the piston body 12 when the piston body 12 and the retainer 21 are assembled in a coupled state.

Thus, in the second embodiment, it is possible to obtain substantially the same operational effects as in the first embodiment. According to the second embodiment, the second sheet portion 21B is configured to provide the flat portion 21B3 between the outer peripheral side taper portion 21B1 and the inner peripheral side taper portion 21B2. In this case, when the piston body 12 and the retainer 21 are assembled, after the flat portion 21B3 comes into contact with the first sheet portion 12E, the inner peripheral side taper portion 21B2 is compressed and deformed by the first sheet portion 12E. Thereby, it can suppress that the 2nd sheet | seat part 21B deform | transforms and the influence of the deformation | transformation by external force reaches the other side annular valve seat of the retainer 21. FIG. As a result, it is possible to prevent the disk valve 15A of the extension side damping force generation mechanism 15 from being deformed, and to suppress variations in the generated damping force.

Next, FIG. 8 shows a third embodiment of the present invention. A feature of the third embodiment resides in that the inner peripheral side taper portion of the second sheet portion of the retainer is formed in an arc shape. Note that in the third embodiment, the same components as those in the first embodiment described above are denoted by the same reference numerals, and descriptions thereof are omitted.

As with the retainer 13 described in the first embodiment, the retainer 31 includes a rod mounting hole (not shown), a plurality of extension side communication passages 31A, a second seat portion 31B, and an other-side annular valve seat. (Not shown).

Here, as shown in FIG. 8, the second sheet portion 31B includes an outer peripheral side taper portion 31B1 and an inner peripheral side taper portion 31B2. Specifically, the second seat portion 31B is in a state before assembling the piston main body 12 and the retainer 31, from one outer peripheral edge of the second seat portion 31B toward the first seat portion 12E side of the piston main body 12. It protrudes in a tapered shape. In this case, the inner peripheral side taper portion 31B2 is curved in an arc shape, and the inclination of the inner peripheral side taper portion 31B2 is set more gently than the inclination of the outer peripheral side taper portion 31B1.

Thus, in the third embodiment, it is possible to obtain substantially the same operational effects as those in the first embodiment. According to the third embodiment, the second sheet portion 31B is configured to have the inner peripheral side taper portion 31B2 curved in an arc shape. Thereby, when the piston main body 12 and the retainer 31 are assembled in a coupled state, the arc-shaped inner circumferential side taper portion 31B2 is compressed and deformed by the first seat portion 12E. As a result, the abutment between the piston body 12 and the retainer 31 can be made smooth.

Next, FIG. 9 shows a fourth embodiment of the present invention. The feature of the fourth embodiment is that a protrusion is formed on the second sheet portion of the retainer. Note that in the fourth embodiment, identical symbols are assigned to configurations identical to those in the first embodiment described above, and descriptions thereof are omitted.

As in the retainer 13 described in the first embodiment, the retainer 41 includes a rod mounting hole (not shown), a plurality of extension-side communication passages 41A, a second seat portion 41B, and the other-side annular valve seat. (Not shown).

Here, as shown in FIG. 9, the second sheet portion 41B is formed in a stepped shape by an outer peripheral side flat portion 41B1, an inner peripheral side flat portion 41B2, and a projection portion 41B3. Specifically, the second seat portion 41B is in a state before assembling the piston main body 12 and the retainer 41, from one outer peripheral edge of the second seat portion 41B toward the first seat portion 12E side of the piston main body 12. It protrudes.

In this case, the protrusion 41B3 is provided between the outer peripheral flat portion 41B1 and the inner peripheral flat portion 41B2. The protrusion 41B3 is formed in a cross-sectional mountain shape, and slightly protrudes toward the piston body 12 from the outer peripheral flat portion 41B1 and the inner peripheral flat portion 41B2. The protrusion 41B3 is plastically deformed when the piston body 12 and the retainer 41 are assembled, and is coupled to the first sheet portion 12E of the piston body 12. That is, the protrusion 41B3 is pressed by the first sheet portion 12E during assembly and is coupled to the first sheet portion 12E in a plastically deformed state.

Thus, in the fourth embodiment, it is possible to obtain substantially the same function and effect as in the first embodiment. According to the fourth embodiment, the second sheet portion 41B has the protruding portion 41B3 that is plastically deformed while being coupled to the first sheet portion 12E. Thereby, when the piston main body 12 and the retainer 41 are assembled in a coupled state, the protrusion 41B3 is plastically deformed and coupled to the first sheet portion 12E. In this case, the second seat portion 41B is plastically deformed and absorbs the coupling force in the upward and downward directions of the piston body 12 and the retainer 41, so that the other annular valve seat of the retainer 41 is influenced by deformation due to external force. Can be suppressed. As a result, it is possible to prevent the disk valve 15A of the extension side damping force generation mechanism 15 from being deformed, and to suppress variations in the generated damping force.

Next, FIG. 10 shows a fifth embodiment of the present invention. The feature of the fifth embodiment is that a protrusion is formed on the second sheet portion of the retainer. Note that in the fifth embodiment, identical symbols are assigned to configurations identical to those in the first embodiment described above, and descriptions thereof are omitted.

As in the retainer 13 described in the first embodiment, the retainer 51 includes a rod mounting hole (not shown), a plurality of extension side communication passages 51A, a second seat portion 51B, and an other-side annular valve seat. (Not shown).

Here, as shown in FIG. 10, the second seat portion 51B is in a state before the piston main body 12 and the retainer 51 are assembled, and the first seat portion of the piston main body 12 from one outer peripheral edge of the second seat portion 51B. It protrudes in a cross-sectional mountain shape toward the 12E side. The top portion of the second sheet portion 51B is plastically deformed when the piston main body 12 and the retainer 41 are assembled to form a protrusion 51B1 that is coupled to the first sheet portion 12E of the piston main body 12. That is, the tip side of the protrusion 51B1 is pressed by the first sheet portion 12E during assembly and is joined to the first sheet portion 12E in a plastically deformed state.

Thus, in the fifth embodiment, it is possible to obtain substantially the same operational effects as those in the first embodiment. According to the fifth embodiment, the second sheet portion 51B has the protruding portion 51B1 that is plastically deformed while being coupled to the first sheet portion 12E. Thereby, when the piston main body 12 and the retainer 51 are assembled in a coupled state, the protrusion 51B1 is plastically deformed and coupled to the first sheet portion 12E. In this case, the second seat portion 51B is plastically deformed and absorbs the upward and downward coupling forces between the piston main body 12 and the retainer 51, so that the other annular valve seat of the retainer 51 is influenced by deformation due to external force. Can be suppressed. As a result, it is possible to prevent the disk valve 15A of the extension side damping force generation mechanism 15 from being deformed, and to suppress variations in the generated damping force.

In the first embodiment, the hydraulic shock absorber 1 attached to each wheel side of the four-wheel vehicle is described as a typical example of the shock absorber. However, the present invention is not limited to this, and may be, for example, a hydraulic shock absorber used for a two-wheeled vehicle, or may be used for a hydraulic shock absorber used for various machines other than vehicles, buildings, and the like. The same applies to the second, third, fourth, and fifth embodiments.

Furthermore, it is needless to say that each of the embodiments described above is an exemplification, and partial replacement or combination of configurations shown in different embodiments is possible.

As the shock absorber based on the embodiment described above, for example, the following modes can be considered.

The first aspect of the shock absorber includes a cylinder in which a working fluid is sealed, a piston that divides the inside of the cylinder into a first chamber and a second chamber, and a damping force generation that is provided in the piston and generates a damping force. A shock absorber having a mechanism, wherein the piston has a first piston body and a second piston body assembled in an abutting state with the first piston body, and the first piston body has the first piston body. An annular first seat portion is provided on the outer peripheral side of the opening of the first passage for communicating between the first chamber and the second chamber, and the second piston body is a second for communicating the first chamber and the second chamber. An annular second sheet portion joined in abutment with the first sheet portion is provided on the outer peripheral side of the opening of the passage, and the damping force generation mechanism includes the first chamber side of the first piston body, The second piston body is disposed on the second chamber side, and the second piston body The toe part has an outer peripheral side taper part and an inner peripheral side taper part that project in a tapered shape toward the first sheet part side in a state before the first piston body and the second piston body are assembled, The inclination of the inner peripheral side taper portion is gentler than the inclination of the outer peripheral side taper portion. Thereby, the dispersion | variation in generated damping force can be suppressed.

As a second aspect, in the first aspect, the second piston body has a seat surface for arranging the damping force generation mechanism on the second chamber side on the side opposite to the second seat portion. The second seat portion is configured to suppress deformation of the seating surface by deformation of the inner peripheral side taper portion when the first piston body and the second piston body are assembled. Thereby, the deformation | transformation of a bearing surface can be suppressed and the dispersion | variation in generated damping force can be suppressed.

Further, as a third aspect, a cylinder in which a working fluid is sealed, a piston that divides the inside of the cylinder into a first chamber and a second chamber, and a damping force generation mechanism that is provided in the piston and generates a damping force The piston has a first piston body and a second piston body assembled in an abutting state with the first piston body, and the first piston body comprises the first piston body. An opening of the second passage which has an annular first seat portion on the outer peripheral side of the opening of the first passage communicating with the chamber and the second chamber, and the second piston body communicates with the first chamber and the second chamber. An annular second sheet portion that is joined in abutment with the first sheet portion, and the damping force generation mechanism includes the first chamber side of the first piston body and the second seat portion. The second seat part is arranged on the side of the second chamber of the piston body. The first piston body and the second piston body are protruded toward the first sheet portion before the first piston body and the second piston body are assembled, and have a protruding portion that is plastically deformed in a state of being coupled to the first sheet portion. Yes. Thereby, the dispersion | variation in generated damping force can be suppressed.

As a fourth aspect, in the third aspect, the second piston body has a seat surface for arranging the damping force generation mechanism on the second chamber side on the side opposite to the second seat portion. The second seat portion is configured to suppress deformation of the seating surface by plastic deformation of the protrusion when the first piston body and the second piston body are assembled. Thereby, the deformation | transformation of a bearing surface can be suppressed and the dispersion | variation in generated damping force can be suppressed.

Although only a few embodiments of the present invention have been described above, various modifications or improvements can be made to the illustrated embodiments without substantially departing from the novel teachings and advantages of the present invention. Will be easily understood by those skilled in the art. Therefore, it is intended that the embodiment added with such changes or improvements is also included in the technical scope of the present invention. You may combine the said embodiment arbitrarily.

This application claims priority based on Japanese Patent Application No. 2016-146453 filed on Jul. 26, 2016. The entire disclosure including the specification, claims, drawings, and abstract of Japanese Patent Application No. 2016-146453 filed on July 26, 2016 is incorporated herein by reference in its entirety.

DESCRIPTION OF SYMBOLS 1 Hydraulic buffer (buffer) 6 Inner cylinder (cylinder) 11 Piston 12 Piston main body (1st piston body) 12B Elongation side communication path (1st path) 12E 1st sheet |

seat part

13, 21, 31, 41, 51 Retainer (Second piston body) 13B, 21A, 31A, 41A, 51A Elongation side communication passage (second passage) 13C, 21B, 31B, 41B, 51B Second seat portion 13C1, 21B1, 31B1 Outer peripheral side taper portion 13C2, 21B2, 31B2 Inner peripheral side taper portion 15 Expansion side damping force generation mechanism (damping force generation mechanism) 16 Contraction side damping force generation mechanism (damping force generation mechanism) 41B3, 51B1 Projection portion B Bottom side chamber (second chamber) C Rod side chamber (first chamber) 1 room)

Claims

A shock absorber, the shock absorber being
A cylinder filled with a working fluid;
A piston that divides the interior of the cylinder into a first chamber and a second chamber;
A damping force generating mechanism that is provided in the piston and generates a damping force;
The piston has a first piston body and a second piston body assembled to the first piston body in an abutting state,
The first piston body has an annular first seat portion on the outer peripheral side of the opening of the first passage for communicating the first chamber and the second chamber,
The second piston body has an annular second seat portion that is coupled to the first seat portion on the outer peripheral side of the opening of the second passage that communicates the first chamber and the second chamber. And
The damping force generation mechanism is disposed on the first chamber side of the first piston body and on the second chamber side of the second piston body, respectively.
The second seat portion includes an outer peripheral taper portion and an inner peripheral taper portion that project in a tapered shape toward the first seat portion in a state before the first piston body and the second piston body are assembled. Have
The shock absorber according to claim 1, wherein an inclination of the inner peripheral side taper portion is gentler than an inclination of the outer peripheral side taper portion.
The shock absorber according to claim 1.
The second piston body has a seat surface for arranging the damping force generation mechanism on the second chamber side on the side opposite to the second seat portion,
The shock absorber according to claim 2, wherein the second seat portion is configured such that deformation of the seating surface is suppressed by deformation of the inner peripheral side taper portion when the first piston body and the second piston body are assembled. .
A shock absorber, the shock absorber being
A cylinder filled with a working fluid;
A piston that divides the interior of the cylinder into a first chamber and a second chamber;
A damping force generating mechanism that is provided in the piston and generates a damping force;
The piston has a first piston body and a second piston body assembled to the first piston body in an abutting state,
The first piston body has an annular first seat portion on the outer peripheral side of the opening of the first passage communicating with the first chamber and the second chamber,
The second piston body has an annular second seat portion that is coupled to the first seat portion on the outer peripheral side of an opening of a second passage communicating with the first chamber and the second chamber. ,
The damping force generation mechanism is disposed on the first chamber side of the first piston body and on the second chamber side of the second piston body, respectively.
The second sheet part protrudes toward the first sheet part in a state before assembling the first piston body and the second piston body, and plastically deforms in a state where the second sheet part is coupled to the first sheet part. A shock absorber having a protrusion.
The shock absorber according to claim 3.
The second piston body has a seat surface for arranging the damping force generation mechanism on the second chamber side on the side opposite to the second seat portion,
The second seat portion is a shock absorber, wherein deformation of the seating surface is suppressed by plastic deformation of the protrusion when the first piston body and the second piston body are assembled.