Shock absorber

Abstract

The shock absorber comprises a cylinder barrel, a piston assembly and a piston rod, the piston assembly is arranged in the cylinder barrel, the piston rod is connected with the piston assembly, and the piston assembly divides the cylinder barrel into a rod cavity and a rodless cavity; a control oil cavity, a first oil way, a second oil way, a third oil way and a fourth oil way are arranged in the piston assembly, one ends of the first oil way and the second oil way are communicated with the rod cavity, and the other ends of the first oil way and the second oil way are communicated with the control oil cavity; one ends of the third oil way and the fourth oil way are communicated with the rodless cavity, and the other ends are communicated with the control oil cavity; the piston assembly further comprises a first one-way valve, a second one-way valve, a third one-way valve and a fourth one-way valve, and the first one-way valve, the second one-way valve, the third one-way valve and the fourth one-way valve correspond to the first oil way, the second oil way, the third oil way and the fourth oil way in a one-to-one mode. The shock absorber provided by the invention is simple in oil path structure and lower in manufacturing cost.

Description

Technical Field

[0001] The invention relates to a shock absorber. Background Art

[0002] The shock absorber is an important component of the vehicle chassis system, which can effectively buffer the vibration of the vehicle chassis. The shock absorber includes a cylinder, a piston assembly, and a piston rod connected to the piston assembly, wherein the piston assembly is in a sealed fit with the inner wall of the cylinder, thereby dividing the space of the cylinder into a first working space and a second working space, and the piston rod is located in one of the working spaces. The piston assembly includes a piston body, a valve group connected to the piston body, and an oil circuit arranged on the piston body.

[0003] The oil circuit conducts the first working space and the second working space, and the valve group is used to control the opening and closing of the oil circuit. When the piston body moves up and down in the cylinder, the valve group controls the oil in the first working space and the second working space to flow back and forth through the oil circuit. At this time, the oil in the oil circuit will damp the movement of the piston body, thereby playing a role in shock absorption.

[0004] A related patent with publication number CN107980084B discloses a controllable shock absorber, which includes a piston assembly and a piston rod, wherein the piston assembly is provided with a compression oil circuit and a rebound oil circuit, and the piston assembly also includes a first valve group for controlling the compression oil circuit and a second valve group for controlling the rebound oil circuit.

[0005] However, in this type of shock absorber, the compression oil circuit and the rebound oil circuit are separate oil circuits, the oil circuit structure is relatively complex, and the manufacturing cost is relatively high. Summary of the invention

[0006] The object of the present invention is to provide a shock absorber with a simple oil circuit structure and low manufacturing cost.

[0007] A shock absorber provided by the present invention comprises a cylinder, a piston assembly and a piston rod, wherein the piston assembly is arranged in the cylinder, the piston rod is connected to the piston assembly, and the piston assembly divides the cylinder into a rod chamber and a rodless chamber;

[0008] The piston assembly is provided with a control oil chamber, a first oil circuit, a second oil circuit, a third oil circuit and a fourth oil circuit, wherein one end of the first oil circuit and the second oil circuit is communicated with the rod chamber, and the other end is communicated with the control oil chamber; one end of the third oil circuit and the fourth oil circuit is communicated with the rodless chamber, and the other end is communicated with the control oil chamber;

[0009] The piston assembly further comprises a first one-way valve, a second one-way valve, a third one-way valve and a fourth one-way valve, wherein the first one-way valve, the second one-way valve, the third one-way valve and the fourth one-way valve are respectively arranged in one-to-one correspondence with the first oil circuit, the second oil circuit, the third oil circuit and the fourth oil circuit;

[0010] When the oil pressure in the rod chamber is greater than the oil pressure in the control oil chamber, and the oil pressure in the control oil chamber is greater than the oil pressure in the rodless chamber, the first one-way valve and the fourth one-way valve are connected; when the oil pressure in the rodless chamber is greater than the oil pressure in the control oil chamber, and the oil pressure in the control oil chamber is greater than the oil pressure in the rod chamber, the third one-way valve and the second one-way valve are connected.

[0011] According to the shock absorber provided by the present invention, the first oil circuit extends in the radial direction of the piston assembly and connects the outer wall of the piston assembly with the control oil chamber.

[0012] According to the shock absorber provided by the present invention, the second oil circuit and the fourth oil circuit both include an axial section, and the axial section coincides with the axis of the piston assembly;

[0013] The second oil circuit further includes an inclined section, one end of which is connected to the axial section of the second oil circuit, and the other end of which is arranged beside the piston rod.

[0014] According to the shock absorber provided by the present invention, the first one-way valve and the third one-way valve each include a valve seat, a valve body, an elastic member and a sealing body; wherein,

[0015] The valve body and the elastic member are arranged on the valve seat, the valve body is provided with a fluid channel, the elastic member acts on the sealing body, and under the elastic force of the elastic member, the sealing body is in sealing contact with the fluid channel of the valve body, when the pressure of the oil acting on the sealing body in the opposite direction to the elastic force is greater than the elastic force, the sealing body is out of contact with the fluid channel.

[0016] According to the shock absorber provided by the present invention, the valve seat comprises a central portion and a positioning portion protruding radially along the central portion;

[0017] The valve body is configured as a cylindrical structure, and one end of the cylindrical structure is provided with a groove structure matched with the positioning portion.

[0018] According to the shock absorber provided by the present invention, the valve seat is provided with at least two first limiting protrusions, each of which is protruded along the axial direction of the valve body, and any two adjacent first limiting protrusions are arranged at intervals;

[0019] The at least two first limiting protrusions enclose a space for accommodating the elastic member and the sealing body, and are capable of restricting the sealing body from moving radially along the valve body.

[0020] According to the shock absorber provided by the present invention, the valve group is provided with a second limiting protrusion, the second limiting protrusion is provided corresponding to the sealing body, and the second limiting protrusion is used to limit the maximum axial displacement of the sealing body.

[0021] According to the shock absorber provided by the present invention, the sealing body is configured as a sphere, the elastic member is configured as a compression spring, one end of the compression spring is sleeved on the outer periphery of the second limiting protrusion, and the other end abuts against the sphere.

[0022] According to the shock absorber provided by the present invention, the second one-way valve and the fourth one-way valve are configured as elastic diaphragms, and the elastic diaphragms include:

[0023] A sealing portion, the projection of which covers the port of the oil circuit;

[0024] A fixing portion, fixedly connected to the piston assembly;

[0025] The elastic connecting part has one end connected to the fixing part and the other end connected to the sealing part, and the elastic connecting part can generate elastic deformation under the action of oil pressure.

[0026] According to the shock absorber provided by the present invention, the fixing portion is provided with a connecting hole, and the fixing portion is fixedly connected to the piston assembly via a fixing pin inserted into the connecting hole.

[0027] According to the shock absorber provided by the present invention, the fixing portion is further provided with a positioning hole, the positioning hole is spaced apart from the connecting hole, and the fixing portion is positioned on the piston assembly by a positioning pin inserted into the positioning hole.

[0028] The shock absorber provided according to the present invention also includes a fifth oil circuit, one end of the fifth oil circuit is connected to the rodless chamber, and the other end is connected to the control oil chamber, and the port of the fifth oil circuit close to the rodless chamber is a tapered structure, and the end of the tapered structure with a smaller diameter is close to the rodless chamber.

[0029] According to the shock absorber provided by the present invention, the piston assembly includes a hydraulic housing, the fourth oil circuit is arranged in the hydraulic housing; and the fifth oil circuit coincides with the axis of the piston assembly.

[0030] The shock absorber provided by the present invention comprises a cylinder, a piston assembly and a piston rod. It should be noted that the piston assembly comprises a piston body, a piston ring, various valve structures connected to the piston body, and other components connected to the piston body and reciprocating with the piston body. The piston assembly is connected to the piston rod through a connecting structure, and the piston assembly divides the cylinder into a rod chamber and a rodless chamber. A control oil chamber, a first oil circuit, a second oil circuit, a third oil circuit and a fourth oil circuit are arranged in the piston assembly, wherein one end of the first oil circuit and the second oil circuit is connected to the rod chamber, and the other end is connected to the control oil chamber; one end of the third oil circuit and the fourth oil circuit is connected to the rodless chamber, and the other end is connected to the control oil chamber. The piston assembly also comprises a first one-way valve, a second one-way valve, a third one-way valve and a fourth one-way valve, wherein the first one-way valve, the second one-way valve, the third one-way valve and the fourth one-way valve are arranged in a one-to-one correspondence with the first oil circuit, the second oil circuit, the third oil circuit and the fourth oil circuit, respectively. When the piston assembly moves from the rodless chamber to the rod chamber, the oil pressure in the rod chamber increases, the oil pressure in the rod chamber is greater than the oil pressure in the control oil chamber, and the oil pressure in the control oil chamber is greater than the oil pressure in the rodless chamber. At this time, the first one-way valve and the fourth one-way valve are connected, and the oil in the rod chamber enters the rodless chamber through the first oil circuit, the control oil chamber, and the fourth oil circuit in sequence, thereby achieving a damping effect; when the piston assembly moves from the rod chamber to the rodless chamber, the oil pressure in the rodless chamber increases, the oil pressure in the rodless chamber is greater than the oil pressure in the control oil chamber, and the oil pressure in the control oil chamber is greater than the oil pressure in the rod chamber. At this time, the third one-way valve and the second one-way valve are connected, and the oil in the rodless chamber enters the rod chamber through the third oil circuit, the control oil chamber, and the second oil circuit in sequence, thereby achieving a damping effect. With such an arrangement, the shock absorber provided by the present invention is provided with a control oil chamber, and the compression and rebound processes of the piston assembly all share one control oil chamber, and oil circuit control can be achieved through the cooperation of various one-way valves. The structure is simple and the manufacturing cost is effectively reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 FIG. 1 is a schematic cross-sectional view of a shock absorber according to an embodiment of the present invention.

[0032] Figure 2 is a partial schematic diagram of a first one-way valve according to an embodiment of the present invention.

[0033] Figure 3 2 is a schematic diagram of an exploded view of a first one-way valve according to an embodiment of the present invention.

[0034] Figure 4 FIG. 4 is a schematic cross-sectional view of a first one-way valve according to an embodiment of the present invention.

[0035] Figure 5 Schematic diagram of a second one-way valve according to an embodiment of the present invention.

[0036] Figure 6Schematic diagram of a fixing pin of a second one-way valve according to an embodiment of the present invention.

[0037] Figure 7 FIG. 4 is a schematic cross-sectional view of a shock absorber according to another embodiment of the present invention.

[0038] Figure 8 is a schematic diagram of a fourth one-way valve according to another embodiment of the present invention. DETAILED DESCRIPTION

[0039] The following detailed description and drawings are used to illustrate the principle of the present invention. The present invention is not limited to the preferred embodiments described. The protection scope of the present invention is defined by the claims.

[0040] It should be noted that the orientations or positional relationships indicated in this specification are based on the orientations or positional relationships described in the accompanying drawings and are only for the convenience and simplification of description, and do not indicate or imply that the device referred to must have a specific orientation or be constructed in a specific orientation. Therefore, it should not be understood as a limitation on the present invention.

[0041] Please refer to Figure 1-Figure 8 The shock absorber provided in this embodiment includes a cylinder, a piston assembly and a piston rod. The piston assembly includes a piston body and other valves, connections and other components arranged on the piston body. The piston body and the cylinder are sealed and can slide along the axial direction of the cylinder. The piston body divides the cylinder into a rod chamber and a rodless chamber. The piston rod is connected to the piston assembly.

[0042] In this embodiment, the piston assembly is provided with a control oil chamber 11, a first oil circuit, a second oil circuit 17, a third oil circuit 14 and a fourth oil circuit 19. One end of the first oil circuit and the second oil circuit 17 is connected to the rod chamber, and the other end is connected to the control oil chamber 11; one end of the third oil circuit 14 and the fourth oil circuit 19 is connected to the rodless chamber, and the other end is connected to the control oil chamber 11.

[0043] The piston assembly further includes a first one-way valve 12, a second one-way valve 18, a third one-way valve 13 and a fourth one-way valve 20. The first one-way valve 12, the second one-way valve 18, the third one-way valve 13 and the fourth one-way valve 20 are respectively arranged in one-to-one correspondence with the first oil circuit, the second oil circuit 17, the third oil circuit 14 and the fourth oil circuit 19.

[0044] It should be noted that when the piston assembly moves from the rodless chamber to the rod chamber, that is, when the piston assembly is in the rebound stroke, the oil pressure in the rod chamber increases, the oil pressure in the rod chamber is greater than the oil pressure in the control oil chamber 11, and the oil pressure in the control oil chamber 11 is greater than the oil pressure in the rodless chamber. At this time, the first one-way valve 12 and the fourth one-way valve 20 are connected, and the oil in the rod chamber enters the rodless chamber through the first oil circuit, the control oil chamber 11, and the fourth oil circuit 19 in turn, thereby achieving the effect of rebound damping.

[0045] When the piston assembly moves from the rod chamber to the rodless chamber, that is, when the piston assembly is in the compression stroke, the oil pressure in the rodless chamber increases, and the oil pressure in the rodless chamber is greater than the oil pressure in the control oil chamber 11, and the oil pressure in the control oil chamber 11 is greater than the oil pressure in the rod chamber. At this time, the third one-way valve 13 and the second one-way valve 18 are connected, and the oil in the rodless chamber enters the rod chamber through the third oil circuit 14, the control oil chamber 11, and the second oil circuit 17 in turn, thereby being able to play a damping effect. In this way, the shock absorber provided in this embodiment is provided with a control oil chamber 11, and the compression and rebound processes of the piston assembly share the same control oil chamber 11, and the oil circuit control can be achieved by the cooperation of each one-way valve, the structure is simple, and the manufacturing cost is effectively reduced.

[0046] In a further embodiment, the first oil circuit extends radially along the piston assembly and connects the outer wall of the piston assembly with the control oil chamber 11. The second oil circuit 17 and the fourth oil circuit 19 both include an axial section 15, which coincides with the axis of the piston assembly. The second oil circuit 17 also includes an inclined section 16, one end of which is connected to the axial section 15 of the second oil circuit 17, and the other end is arranged at the side of the piston rod. With such an arrangement, the layout of each oil circuit is reasonable and convenient for processing and manufacturing.

[0047] In some embodiments, the first one-way valve 12 and the third one-way valve 13 both include a valve seat, a valve body 127, an elastic member 123 and a sealing body 125. The valve seat cooperates with the valve body 127, a fluid channel is provided on the valve body 127, and the elastic member 123 and the sealing body 125 are provided on the valve seat, the elastic member 123 acts on the sealing body 125, and the sealing body 125 is in sealing contact with the fluid channel of the valve body 127 under the elastic force of the elastic member 123, when the pressure of the oil acting on the sealing body 125 in the opposite direction of the elastic force is greater than the elastic force, the sealing body 125 is disconnected from the fluid channel, when the sealing body 125 is disconnected from the fluid channel, the fluid channel is open, and the oil can flow through the one-way valve. When the pressure of the oil acting on the sealing body 125 is in the same direction as the elastic force of the elastic member 123 acting on the sealing body 125, the sealing body 125 always maintains a sealing contact with the fluid channel, and the one-way valve is in a closed state.

[0048] In order to improve the matching stability between the valve seat and the valve body 127, the valve seat further includes a central portion 121 and a positioning portion 122 protruding radially along the central portion 121. The positioning portion 122 can be specifically a block structure, and can be provided in multiple numbers, and the multiple positioning portions 122 are evenly distributed on the outer periphery of the central portion 121. Accordingly, the valve body 127 is provided as a cylindrical structure, the valve seat is installed at one end of the valve body 127, and the end of the valve body 127 corresponding to the valve seat is provided with a groove structure 128 matching the positioning portion 122. When the valve seat and the valve body 127 are assembled, the positioning portion 122 on the valve seat is installed in the groove structure 128 of the valve body 127 in a one-to-one correspondence. Under the limiting effect of the groove structure 128, the relative rotation between the valve seat and the valve body 127 can be limited, thereby improving the stability between the two.

[0049] In order to make the sealing body 125 have better stability, in a further embodiment, the valve seat is provided with at least two first limiting protrusions 124, each of which protrudes along the axial direction of the valve body 127, and any two adjacent first limiting protrusions 124 are arranged at intervals. At least two first limiting protrusions 124 enclose a space for accommodating the elastic member 123 and the sealing body 125, and can restrict the radial displacement of the sealing body 125 along the valve body 127.

[0050] The above-mentioned first limiting protrusion 124 can be specifically a protruding structure that protrudes from the center portion 121 of the valve seat along the axial direction of the valve body 127, and the space surrounded by multiple first limiting protrusions 124 for accommodating the sealing body 125 can be a cylindrical space. The sealing body 125 is a sphere, which is arranged in the cylindrical space and can only move along the axial direction of the cylindrical space, while the radial displacement of the cylindrical space is limited, thereby enabling the sealing body 125 to displace in a single direction, so that the sealing body 125 can accurately seal the fluid channel on the valve body 127.

[0051] In order to limit the maximum displacement of the sealing body 125, the central portion 121 of the valve seat may be provided with a second limiting protrusion 126, which is provided corresponding to the sealing body 125 and is used to limit the maximum axial displacement of the sealing body 125. That is, when the sealing body 125 is displaced to a certain distance in the direction close to the valve seat by the pressure of the oil and then abuts against the second limiting protrusion 126, the sealing body 125 stops displacing under the limiting effect of the second limiting protrusion 126.

[0052] It should be noted that, in this embodiment, the sealing body 125 can be configured as a sphere, and the elastic member 123 can be configured as a compression spring, one end of the compression spring is sleeved on the outer periphery of the second limiting protrusion 126, and the other end is against the sphere.

[0053] In some embodiments, the second one-way valve 18 and the fourth one-way valve 20 are arranged at the two end portions in the axial direction of the piston assembly. Therefore, the second one-way valve 18 and the fourth one-way valve 20 can be arranged in the form of an elastic diaphragm for installation. Specifically, the elastic diaphragm includes a sealing portion 201, a fixing portion and an elastic connecting portion 202. The projection of the sealing portion 201 covers the port of the oil circuit. When the elastic diaphragm is not subjected to external force, the sealing portion 201 covers the port of the oil circuit and seals the port of the oil circuit. The fixing portion is used to be fixedly connected to the piston assembly. One end of the elastic connecting portion 202 is connected to the fixing portion, and the other end is connected to the sealing portion 201, and the elastic connecting portion 202 can produce elastic deformation under the action of oil pressure. In this embodiment, the second one-way valve 18 and the fourth one-way valve 20 are respectively installed at the port positions of the second oil circuit 17 and the fourth oil circuit 19. The second one-way valve 18 and the fourth one-way valve 20 are connected to the piston assembly through the fixing portion, and the sealing portion 201 covers the port and seals the port.

[0054] In some embodiments, the fixing portion is provided with a connecting hole 203, and the fixing portion is fixedly connected to the piston assembly by a fixing pin 205 inserted in the connecting hole 203. The fixing pin 205 can be set as a stepped structure. That is, the fixing pin 205 includes a small diameter section and a large diameter section, the small diameter section is inserted in the connecting hole 203, and the end face of the large diameter section is pressed on the fixing portion of the elastic diaphragm, thereby realizing the connection between the fixing portion and the piston assembly. Further, the fixing portion is also provided with a positioning hole 204, and the positioning hole 204 is spaced apart from the connecting hole 203, and the fixing portion is positioned on the piston assembly by a positioning pin inserted in the positioning hole 204. In this way, under the action of the fixing pin 205 and the positioning pin, the elastic diaphragm can be fixedly connected to the piston assembly, and the problem of the sealing portion 201 not corresponding to the oil circuit port caused by the rotation of the elastic diaphragm can be prevented.

[0055] In addition, it should be noted that the elastic connection part 202 can extend along an arc. In this way, the overall size of the one-way valve is small, and the elastic connection part 202 has a sufficient length to ensure that it has a sufficient elastic deformation.

[0056] In another embodiment of the present invention, please refer to Figure 7 and Figure 8The shock absorber also includes a fifth oil circuit 21, one end of the fifth oil circuit 21 is connected to the rodless chamber, and the other end is connected to the control oil chamber 11, and the port of the fifth oil circuit 21 close to the rodless chamber is a constriction structure 22, and the end of the constriction structure 22 with a smaller diameter is close to the rodless chamber. When the piston assembly is in the compression stroke, the oil in the rodless chamber passes through the third oil circuit 14, the control oil chamber 11, and the second oil circuit 17 in sequence to enter the rod chamber. At the same time, the oil in the rodless chamber will enter the control oil chamber 11 through the constriction of the fifth oil circuit 21, and enter the rod chamber through the second oil circuit 17, so that the feedback area of ​​the compression stroke is increased on the original feedback area, and the damping force of the compression stroke is reduced.

[0057] In addition, it should be noted that in this embodiment, the piston assembly includes a hydraulic housing, the fourth oil circuit 19 is arranged in the hydraulic housing, and the fifth oil circuit 21 coincides with the axis of the piston assembly. In this arrangement, the structures of the oil circuits are simple and will not interfere with each other.

[0058] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

[0059] Reference numerals list

[0060] 11: control oil chamber; 12: first one-way valve; 13: third one-way valve; 14: third oil circuit; 15: axial section; 16: inclined section; 17: second oil circuit; 18: second one-way valve; 19: fourth oil circuit; 20: fourth one-way valve; 121: center portion; 122: positioning portion; 123: elastic member; 124: first limiting protrusion; 125: sealing body; 126: second limiting protrusion; 127: valve body; 128: groove structure; 201: sealing portion; 202: elastic connecting portion; 203: connecting hole; 204: positioning hole; 205: fixing pin; 21: fifth oil circuit; 22: shrinkage structure.

Claims

1. A shock absorber comprising a cylinder, a piston assembly and a piston rod, wherein: The piston assembly is arranged in the cylinder barrel, the piston rod is connected to the piston assembly, and the piston assembly divides the cylinder barrel into a rod chamber and a rodless chamber; The piston assembly is provided with a control oil chamber (11), a first oil circuit, a second oil circuit (17), a third oil circuit (14) and a fourth oil circuit (19), wherein one end of the first oil circuit and the second oil circuit (17) are connected to the rod chamber, and the other end is connected to the control oil chamber (11); one end of the third oil circuit (14) and the fourth oil circuit (19) are connected to the rodless chamber, and the other end is connected to the control oil chamber (11); The piston assembly further comprises a first one-way valve (12), a second one-way valve (18), a third one-way valve (13) and a fourth one-way valve (20), wherein the first one-way valve (12), the second one-way valve (18), the third one-way valve (13) and the fourth one-way valve (20) are respectively arranged in one-to-one correspondence with the first oil circuit, the second oil circuit (17), the third oil circuit (14) and the fourth oil circuit (19); When the oil pressure in the rod chamber is greater than the oil pressure in the control oil chamber (11), and the oil pressure in the control oil chamber (11) is greater than the oil pressure in the rodless chamber, the first one-way valve (12) and the fourth one-way valve (20) are connected; when the oil pressure in the rodless chamber is greater than the oil pressure in the control oil chamber (11), and the oil pressure in the control oil chamber (11) is greater than the oil pressure in the rod chamber, the third one-way valve (13) and the second one-way valve (18) are connected.

2. The shock absorber according to claim 1, wherein: The first oil passage extends in the radial direction of the piston assembly and connects the outer side of the piston assembly with the control oil chamber (11).

3. The shock absorber according to claim 1, wherein: The second oil circuit (17) and the fourth oil circuit (19) both include an axial section (15), and the axial section (15) coincides with the axis of the piston assembly; The second oil circuit (17) further comprises an inclined section (16), wherein one end of the inclined section (16) is connected to the axial section (15) of the second oil circuit (17), and the other end is arranged at a side position of the piston rod.

4. The shock absorber according to claim 1, wherein: The first one-way valve (12) and the third one-way valve (13) both comprise a valve seat, a valve body (127), an elastic member (123) and a sealing body (125); wherein: The valve body (127) and the elastic member (123) are arranged on the valve seat, the valve body (127) is provided with a fluid channel, the elastic member (123) acts on the sealing body (125), and under the elastic force of the elastic member (123), the sealing body (125) is in sealing contact with the fluid channel of the valve body (127), and when the pressure of the oil acting on the sealing body (125) in the opposite direction to the elastic force is greater than the elastic force, the sealing body (125) is out of contact with the fluid channel.

5. The shock absorber according to claim 4, wherein: The valve seat comprises a central portion (121) and a positioning portion (122) protruding radially along the central portion (121); The valve body (127) is configured as a cylindrical structure, and one end of the cylindrical structure is provided with a groove structure (128) that matches the positioning portion (122).

6. The shock absorber according to claim 4, wherein: The valve seat is provided with at least two first limiting protrusions (124), each of the first limiting protrusions (124) protrudes along the axial direction of the valve body (127), and any two adjacent first limiting protrusions (124) are arranged at intervals; The at least two first limiting protrusions (124) enclose a space for accommodating the elastic member (123) and the sealing body (125), and are capable of restricting the radial displacement of the sealing body (125) along the valve body (127).

7. The shock absorber according to claim 4, wherein: The valve seat is provided with a second limiting protrusion (126), the second limiting protrusion (126) is arranged corresponding to the sealing body (125), and the second limiting protrusion (126) is used to limit the maximum axial displacement of the sealing body (125).

8. The shock absorber according to claim 7, wherein: The sealing body (125) is configured as a sphere, and the elastic member (123) is configured as a compression spring, one end of the compression spring is sleeved on the outer periphery of the second limiting protrusion (126), and the other end is in contact with the sphere.

9. The shock absorber according to claim 1, wherein: The second one-way valve (18) and the fourth one-way valve (20) are constructed as elastic diaphragms, and the elastic diaphragms include: A sealing portion (201), the projection of which covers the port of the oil circuit; A fixing portion, fixedly connected to the piston assembly; The elastic connecting part (202) has one end connected to the fixing part and the other end connected to the sealing part (201), and the elastic connecting part (202) can generate elastic deformation under the action of oil pressure.

10. The shock absorber according to claim 9, wherein: The fixing portion is provided with a connecting hole (203), and the fixing portion is fixedly connected to the piston assembly via a fixing pin (205) inserted into the connecting hole (203).

11. The shock absorber according to claim 10, wherein: The fixing portion is further provided with a positioning hole (204), the positioning hole (204) being spaced apart from the connecting hole (203), and the fixing portion is positioned on the piston assembly via a positioning pin inserted into the positioning hole (204).

12. The shock absorber according to claim 1 further includes a fifth oil circuit (21), one end of the fifth oil circuit (21) is connected to the rodless chamber, and the other end is connected to the control oil chamber (11), and the port of the fifth oil circuit (21) close to the rodless chamber is a tapered structure (22), and the end of the tapered structure (22) with a smaller diameter is close to the rodless chamber.

13. The shock absorber according to claim 12, wherein: The piston assembly comprises a hydraulic housing, the fourth oil circuit (19) is arranged in the hydraulic housing; the fifth oil circuit (21) coincides with the axis of the piston assembly.

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