CN213017440U - Shock absorber - Google Patents

Abstract

The utility model relates to a shock absorber, which comprises a shell, a buffer mechanism, a pressure relief channel and a pressure relief stop component, wherein the buffer mechanism is arranged in the shell, the buffer mechanism comprises an air storage chamber and an oil chamber, when the shock absorber is compressed, the air storage chamber is compressed and becomes smaller, and when the shock absorber is extended, the air storage chamber is extended and becomes larger; when the shock absorber is in a compressed state, if the internal oil pressure is too high, part of oil can flow into the pressure relief channel and be relieved by the pressure relief stop component. The utility model has the advantages that the compression and the extension of the air storage chamber can effectively avoid shock and have better safety. Moreover, the rider can adjust the damping value conveniently and quickly by changing the air pressure preference according to the habit of the rider. In addition, when the internal oil pressure is too high, the internal oil can be released to the outside through the pressure release channel to achieve the purpose of explosion prevention.

Description

Shock absorber

Technical Field

The utility model relates to a shock absorber.

Background

The shock absorber is one of the essential devices of the vehicle body, and is mainly used to absorb the impact of the continuous up-and-down vibration of the vehicle body during the traveling along with the road surface bump, so that the rider can feel comfortable. Wherein, the shock absorber mainly converts the impulse force into heat energy to be consumed through the resistance generated when the internal oil body flows through each element (such as the piston and the damping hole), thereby achieving the purpose of buffering and absorbing shock.

However, most shock absorbers on the market today have a fixed shock absorbing performance, and a rider cannot adjust the damping immediately according to his favorite habit, so that the rider cannot feel comfortable feeling during riding. In other words, the present shock absorber structure cannot really meet the user's requirement, and therefore, there is a need to provide a new and improved shock absorber to solve the above-mentioned problems.

Disclosure of Invention

An object of the utility model is to provide a shock absorber.

In order to achieve the above purpose, the utility model adopts the following technical scheme:

a shock absorber, comprising: a shell, a buffer mechanism, a pressure relief channel and a pressure relief stop component; the housing includes a first outer tube and a second outer tube connected to each other by sliding, the inside of the first outer tube and the inside of the second outer tube are connected to each other to form an inner space; the buffer mechanism comprises a damping unit and a pushing unit, the damping unit comprises an inner cylinder component, a floating piston and an oil through valve body, the inner cylinder assembly includes a first inner cylinder and a second inner cylinder, the first inner cylinder is positioned inside the first outer tube, the oil-through valve is positioned in the first inner cylinder and divides the first inner cylinder into a first chamber and a second chamber, the floating piston is movably accommodated in the first chamber and divides the first chamber into an air storage chamber and an oil chamber which are not communicated with each other, the gas storage chamber is pre-stored with gas under a certain pressure, the oil chamber and the second chamber are selectively communicated with each other through the oil through valve, one end of the second inner cylinder is connected to the first inner cylinder and further communicated with the second chamber, the second inner cylinder is provided with oil bodies, one end of the pushing unit is positioned inside the second outer tube, and the other end of the pushing unit is movably inserted into the other end of the second inner tube for pushing the oil body; the pressure relief channel penetrates through the inner cylinder component, one end of the pressure relief channel is used for communicating at least one of the oil chamber, the second chamber and the second inner cylinder, and the other end of the pressure relief channel is used for communicating the inner space; the pressure relief stopping assembly is arranged on the inner cylinder assembly and normally blocks the pressure relief channel, when the oil pressure in the oil chamber, the second chamber and the second inner cylinder rises to a preset pressure, part of oil enters the inner space through the pressure relief stopping assembly so as to reduce the oil pressure in the oil chamber, the second chamber and the second inner cylinder; when the shock absorber is compressed, the first outer tube and the second outer tube are relatively close to each other, and the pushing unit drives the oil body in the second inner tube to enter the oil chamber through the oil through valve body so as to push the floating piston to move towards the direction far away from the oil through valve body, thereby compressing the space of the air storage chamber; when the shock absorber is extended, the gas in the gas storage chamber pushes the floating piston to move towards the direction close to the oil through valve body so as to compress the space of the oil chamber, and further drives the oil body to flow back to the second inner cylinder through the oil through valve body so as to push the pushing unit, so that the first outer pipe and the second outer pipe are relatively far away.

The utility model has the advantages that the compression and the extension of the air storage chamber can effectively avoid shock and have better safety. Moreover, the rider can adjust the damping value conveniently and quickly by changing the air pressure preference according to the habit of the rider. In addition, when the internal oil pressure is too high, the internal oil can be released to the outside through the pressure release channel to achieve the purpose of explosion prevention.

Drawings

FIG. 1 is a schematic view showing an overall structure of a shock absorber according to an embodiment;

FIG. 2 is a schematic view of the partially exploded structure shown in FIG. 1;

FIG. 3 is a schematic view of the overall structure of the oil through valve body in the embodiment;

FIG. 4 is a cross-sectional view of the shock absorber in the embodiment;

FIG. 5 is an enlarged view at I of FIG. 4 (with the shock absorber in compression);

FIG. 6 is an enlarged view at I of FIG. 4 (with the shock absorber extended);

FIG. 7 is a flow chart of oil during compression of the shock absorber in the embodiment;

FIG. 8 is a flow chart of oil when the shock absorber is extended in the embodiment;

FIG. 9 is an operation diagram of the pressure relief channel and the pressure relief stop assembly (at II in FIG. 5);

fig. 10 is another operation diagram of the pressure relief channel and the pressure relief stop assembly (at ii in fig. 5).

Reference numerals:

31, a first inner cylinder; 32, a second inner cylinder; 33, a floating piston;

34, an oil through valve body; 343, compressing the flow channel; 344 is a rebound runner;

411, a first sheet;

42: a second cover assembly; 421 a first elastic member; 422, a base; 423, a valve plate;

52, a communicating pipe; 521, a fluid channel;

53, an oil regulating mechanism; 531 adjusting the rod needle; 532, top; 533 an adjusting pipe; 536: a second elastic member;

6, oil seal seat;

821, a positioning external member; 822: a second sheet.

Detailed Description

The following description is given by way of example only, and not by way of limitation, of the scope of the present disclosure.

Referring to fig. 1 to 10, an embodiment of the present invention is shown, in which a shock absorber includes: a housing 1, a buffer mechanism 2, a pressure relief channel 81 and a pressure relief stop assembly 82.

The housing 1 comprises a first outer tube 11 and a second outer tube 12 connected to each other by sliding, the inside of the first outer tube 11 and the inside of the second outer tube 12 are connected to each other to form an inner space 13; in this embodiment, the radial dimension of the first outer tube 11 is larger than the radial dimension of the second outer tube 12.

The damping mechanism 2 includes a damping unit 21 and a pushing unit 22, the damping unit 21 includes an inner cylinder assembly 3, a floating piston 33 and an oil through valve 34.

The inner barrel assembly 3 includes a first inner barrel 31 and a second inner barrel 32, the first inner barrel 31 is positioned inside the first outer barrel 11, in this embodiment, the first inner barrel 31 is screwed on the first outer barrel 11 for assembly. The oil valve 34 is positioned in the first inner cylinder 31 and divides the first inner cylinder into a first chamber 311 and a second chamber 314, the floating piston 33 is movably accommodated in the first chamber 311 and divides the first chamber into an air storage chamber 312 and an oil chamber 313 which are not communicated with each other, the air storage chamber 312 is pre-stored with gas with certain pressure, preferably nitrogen, and has the advantages of good stability and incombustibility. Wherein, the oil chamber 313 and the second chamber 314 are selectively communicated with each other through the oil passing valve 34, one end of the second inner cylinder 32 is connected to the first inner cylinder 31 to further communicate with the second chamber 314, the second inner cylinder 32 is provided with an oil body (such as damping oil with better viscosity), one end of the pushing unit 22 is positioned inside the second outer tube 12, and the other end of the pushing unit 22 is movably inserted into the other end of the second inner cylinder 32 to push against the oil body.

More specifically, when the shock absorber is compressed, the first outer tube 11 and the second outer tube 12 approach each other, the pushing unit 22 drives the oil in the second inner tube 32 to enter the oil chamber 313 through the oil through valve 34, so as to push the floating piston 33 to move away from the oil through valve 34, thereby compressing the space of the air storage chamber 312. On the contrary, when the shock absorber is extended, the gas in the gas storage chamber 312 pushes the floating piston 33 to move toward the direction close to the oil through valve 34 to compress the space of the oil chamber 313, so as to drive the oil to flow back to the second inner cylinder 32 through the oil through valve 34 to push the pushing unit 22, and thus the first outer tube and the second outer tube are relatively far away.

It is emphasized that the pressure relief channel 81 is disposed through the inner cylinder assembly 3, one end of the pressure relief channel 81 is used to communicate with at least one of the oil chamber 313, the second chamber 314 and the second inner cylinder 32, and the other end of the pressure relief channel 81 is used to communicate with the inner space 13. The pressure release stopping component 82 is disposed on the inner cylinder component 3 and normally blocks the pressure release channel 81, when the oil pressure in the oil chamber 313, the second chamber 314 and the second inner cylinder 32 rises to a predetermined pressure, a part of oil can enter the inner space 13 through the pressure release stopping component 82 under the driving of the pressure, so that the oil pressure in the oil chamber 313, the second chamber 314 and the second inner cylinder 32 is reduced, and the oil pressure in the oil chamber 313, the second chamber 314 and the second inner cylinder 32 can be maintained within a safe value, thereby effectively preventing the occurrence of explosion caused by excessive oil pressure.

In the embodiment, the damping unit 21 further includes an oil seal seat 6, the oil seal seat 6 is used to connect the first inner cylinder 31 and the second inner cylinder 32, and has a better connection sealing degree and is easy to assemble, the pressure relief channel 81 is disposed through the oil seal seat 6 to communicate the second chamber 314 and the inner space 13, and the pressure relief stop component 82 is fixedly sleeved on the second inner cylinder 32 to normally cover and stop the opening of the pressure relief channel 81. More specifically, the pressure relief stop assembly 82 includes a positioning sleeve 821 and a plurality of second sheets 822 stacked in a stacked configuration, the plurality of second sheets 822 are sleeved on the second inner cylinder 32 to cover and stop the opening of the pressure relief channel 81, the positioning sleeve 821 is screwed on the second inner cylinder 32, and the plurality of second sheets 822 are sandwiched between the positioning sleeve 821 and the oil seal seat 6.

Preferably, the shock absorber further comprises an exhaust assembly 7, the exhaust assembly 7 is provided with an exhaust channel 71 penetrating the first inner barrel 31 and a stopper 72, the exhaust channel 71 is communicated with the inner space 13, and the stopper 72 is disposed on the exhaust channel 71 for blocking the communication with the outside. When the rider feels that the relative movement between the first outer tube 11 and the second outer tube 12 is not smooth, the stopper 72 can be removed to allow the excess gas in the inner space 13 to be discharged, so that the pressure can be reduced to a proper pressure.

Preferably, the damping unit 21 further comprises an air adjusting mechanism 51, the air adjusting mechanism 51 comprises an air passage 511 and an air valve 512, the air passage 511 is disposed in the first inner cylinder 31 to communicate with the outside and the air storage chamber 312, the air valve 512 is disposed in the air passage 511 to selectively block the air storage chamber 312 from communicating with the outside; wherein, the gas passage 511 can change the gas amount in the gas storage chamber 312, so as to adjust the pressure of the gas storage chamber 312 to generate different damping effects. For example, when the air pressure in the air storage chamber 312 is large, the approaching speed of the first outer tube 11 and the second outer tube 12 is slow (the damper is hard), and a large impulse is required to actuate the compression of the damper; on the contrary, when the air pressure in the air storage chamber 312 is small, the first outer tube 11 and the second outer tube 12 approach each other quickly (the damper is called soft), and only a small impulse is required to actuate the damper to compress.

The damping unit 21 further includes a communicating pipe 52, the communicating pipe 52 is coaxially disposed with the inner cylinder assembly 3, the communicating pipe 52 is positioned inside the first inner cylinder 31, at least one fluid channel 521 is disposed through the communicating pipe 52, the at least one fluid channel 521 communicates with the oil chamber 313 and the inside of the second inner cylinder 32, the floating piston 33 is slidably sleeved on the communicating pipe 52, and the oil valve 34 is fixedly sleeved on the communicating pipe 52. In this embodiment, the communicating tube 52 is screwed to the first inner barrel 31 for assembly and disassembly; moreover, the number of the at least one fluid channel 521 is two, and the two fluid channels 521 can allow the oil to uniformly flow between the oil chamber 313 and the inner portion of the second inner cylinder 32.

Preferably, the damping unit 21 further includes an oil adjusting mechanism 53, the oil adjusting mechanism 53 includes an adjusting rod needle 531 and an adjusting port 534, the adjusting port 534 is transversely disposed inside the communicating pipe 52 and communicates with the second inner cylinder 32 and the two fluid passages 521, the adjusting rod needle 531 is externally controlled and movably inserted inside the communicating pipe 52, and a top 532 of the adjusting rod needle 531 selectively penetrates through the adjusting port 534 to change the size of the radial opening of the adjusting port 534. Therefore, the compression damping can be adjusted by changing the size of the adjusting opening 534, and when the opening of the adjusting opening 534 is smaller, the compression damping is larger, and the speed of the liquid flowing back to the second inner cylinder 32 is slower; conversely, when the opening of the adjustment port 534 is larger, the compression damping is smaller, and the speed of the liquid flowing back to the second inner cylinder 32 is higher. It can be understood that the oil adjusting mechanism 53 can be used in conjunction with the air adjusting mechanism 51 to perform dual adjustment of compression damping, thereby achieving a wider adjustment range and finer adjustment.

In this embodiment, the oil adjusting mechanism 53 further includes an adjusting tube 533 and a second elastic member 536, the adjusting tube 533 is located inside the communicating tube 52, the adjusting port 534 is disposed on a side of the adjusting tube 533 facing the air storage chamber 312, a connecting port 535 is disposed on a side of the adjusting tube 533 facing away from the air storage chamber 312, the connecting port 535 is communicated with the second inner tube 32, and the second elastic member 536 is abutted between a port edge of the adjusting port 534 and the adjusting rod needle 531, so that the top 532 normally has a tendency of being away from the adjusting port 534. More specifically, the oil adjusting mechanism 53 is further provided with a knob 537 and a screw 538 for external rotation, the knob 537 and the screw 538 are rotatably positioned on the first inner cylinder 31, the screw 538 is movably screwed between the adjusting rod needle 531 and the knob 537, and the adjusting rod needle 531 is clamped between the screw 538 and the second elastic member 536.

It is worth mentioning that the oil through valve 34 has a first side 341 facing the air storage chamber 312, a second side 342 facing the second inner cylinder 32, and a plurality of compression flow passages 343 and a plurality of rebound flow passages 344 axially passing through the first side 341 and the second side, the plurality of compression flow passages 343 and the plurality of rebound flow passages 344 are alternately arranged along the circumferential direction and are not communicated with each other, a first cover assembly 41 is disposed on the first side 341 and only covers the plurality of compression flow passages 343 and not covers the plurality of rebound flow passages 344, and a second cover assembly 42 is disposed on the second side 342 and only covers the plurality of rebound flow passages 344 and not covers the plurality of compression flow passages 343.

Specifically, the first covering assembly 41 includes a plurality of first sheets 411 arranged in a stacked manner, the second covering assembly 42 has a first elastic member 421, a base 422 and a valve plate 423, the base 422 is positioned on the communication pipe 52, the valve plate 423 is movably sleeved on the communication pipe 52, the first elastic member 421 elastically abuts between the base 422 and the valve plate 423, and the valve plate 423 normally covers the plurality of resilient flow passages 344. More specifically, when the shock absorber is compressed and the oil body reaches a predetermined pressure, the oil body moves toward the air storage chamber 312 to push the first cover component 41 to open (the plurality of first thin sheets 411 flex to open), and the oil body can enter the oil chamber 313 through the plurality of compression flow passages 343 and the communication pipe 52; when the shock absorber is extended, the oil body moves in a direction away from the air storage chamber 312 to open the second cover assembly 42 (the first elastic member 421 compresses, the valve plate 423 retreats from the resilient flow passages 344 and opens), and the oil body can flow back to the second inner cylinder 32 through the resilient flow passages 344 and the communication pipe 52.

In summary, the shock absorber of the present invention can rapidly respond to the compression stroke and the extension stroke by separating the air storage chamber and the oil chamber with variable volume size through the floating piston. Furthermore, a pressure relief channel and a pressure relief stop component are designed to properly release the oil inside to reduce the oil pressure, thereby achieving the purpose of explosion prevention. In addition, the user can adjust the compression damping by the air adjusting mechanism and the oil adjusting mechanism, so as to provide more diversified and appropriate shock absorption effects according to different environments.

Claims (10)

1. A shock absorber, comprising:

a housing, including a first outer tube and a second outer tube connected with each other by sliding, the inside of the first outer tube and the inside of the second outer tube are connected with each other to form an inner space;

a buffer mechanism, which comprises a damping unit and a pushing unit, wherein the damping unit comprises an inner cylinder component, a floating piston and an oil through valve body, the inner cylinder assembly includes a first inner cylinder and a second inner cylinder, the first inner cylinder is positioned inside the first outer tube, the oil-through valve is positioned in the first inner cylinder and divides the first inner cylinder into a first chamber and a second chamber, the floating piston is movably accommodated in the first chamber and divides the first chamber into an air storage chamber and an oil chamber which are not communicated with each other, the gas storage chamber is pre-stored with gas under a certain pressure, the oil chamber and the second chamber are selectively communicated with each other through the oil through valve, one end of the second inner cylinder is connected to the first inner cylinder and further communicated with the second chamber, the second inner cylinder is provided with oil bodies, one end of the pushing unit is positioned inside the second outer tube, and the other end of the pushing unit is movably inserted into the other end of the second inner tube for pushing the oil body;

a pressure relief passage passing through the inner cylinder assembly, one end of the pressure relief passage being used for communicating at least one of the oil chamber, the second chamber and the second inner cylinder, and the other end of the pressure relief passage being used for communicating the inner space; and

the pressure relief stopping component is arranged on the inner cylinder component and is used for normally stopping the pressure relief channel, and when the oil pressure of the oil chamber, the second chamber and the second inner cylinder rises to a preset pressure, part of oil enters the inner space through the pressure relief stopping component so as to reduce the oil pressure of the oil chamber, the second chamber and the second inner cylinder;

when the shock absorber is compressed, the first outer tube and the second outer tube are relatively close to each other, and the pushing unit drives the oil body in the second inner tube to enter the oil chamber through the oil through valve body so as to push the floating piston to move towards the direction far away from the oil through valve body, thereby compressing the space of the air storage chamber;

when the shock absorber is extended, the gas in the gas storage chamber pushes the floating piston to move towards the direction close to the oil through valve body so as to compress the space of the oil chamber, and further drives the oil body to flow back to the second inner cylinder through the oil through valve body so as to push the pushing unit, so that the first outer pipe and the second outer pipe are relatively far away.

2. A shock absorber according to claim 1, wherein the damping unit further comprises an air adjustment mechanism, the air adjustment mechanism comprises an air passage and an air valve, the air passage is disposed in the first inner cylinder to communicate with the outside and the air chamber, and the air valve is disposed in the air passage to selectively block the air chamber from communicating with the outside.

3. A shock absorber according to claim 1, wherein the damping unit further includes a communicating tube coaxially disposed with the inner tube assembly, the communicating tube is positioned inside the first inner tube, at least one fluid passage is formed through the communicating tube, the at least one fluid passage communicates with the oil chamber and the inside of the second inner tube, the floating piston is slidably sleeved on the communicating tube, and the oil communicating valve is fixedly sleeved on the communicating tube.

4. A shock absorber according to claim 3, wherein the oil through valve body has a first side portion facing the air reservoir, a second side portion facing the second inner cylinder, and a plurality of compression passages and a plurality of rebound passages extending axially therethrough, the plurality of compression runners and the plurality of rebound runners are arranged alternately along the circumferential direction and are not communicated with each other, a first covering component is arranged on the first side part and only covers the plurality of compression runners but not covers the plurality of rebound runners, a second covering component is arranged on the second side part and only covers the plurality of rebound runners but not covers the plurality of compression runners, the second covering component is provided with a first elastic piece, a base and a valve plate, the base is positioned on the communicating pipe, the valve plate is movably sleeved on the communicating pipe, and the first elastic piece elastically props against the base and the valve plate, so that the valve plate normally covers the plurality of rebound runners; wherein, when the shock absorber is compressed and the oil body reaches a predetermined pressure, the oil body moves towards the direction of the air storage chamber to push the first covering component to open, and the oil body can enter the oil chamber through the plurality of compression runners and the communicating pipe; when the shock absorber is extended, the oil body moves in a direction away from the air storage chamber to push the second cover component to open, and the oil body can flow back to the second inner cylinder through the plurality of rebound runners and the communication pipe.

5. A shock absorber according to claim 3, wherein the damping unit further includes an oil adjusting mechanism, the oil adjusting mechanism includes an adjusting rod pin and an adjusting port, the adjusting port is transversely disposed inside the communicating tube and communicates with the second inner tube and the at least one fluid passage, the adjusting rod pin is externally controlled and movably inserted inside the communicating tube, and a top of the adjusting rod pin selectively penetrates through the adjusting port to change a size of a radial opening of the adjusting port.

6. A shock absorber according to claim 5, wherein the oil adjusting mechanism further comprises an adjusting tube and a second elastic member, the adjusting tube is located inside the communicating tube, and the adjusting opening is disposed on a side of the adjusting tube facing the air storage chamber, a connecting opening is disposed on a side of the adjusting tube facing away from the air storage chamber, the connecting opening is communicated with the second inner tube, and the second elastic member is elastically abutted between the opening edge of the adjusting opening and the adjusting pin, so that the top portion normally tends to be away from the adjusting opening.

7. A shock absorber according to claim 6, wherein the oil adjusting mechanism further comprises a knob and a screw for external rotation, the knob and the screw are rotatably connected, the knob is rotatably positioned in the first inner cylinder, the screw is movably screwed between the adjusting rod pin and the knob, and the adjusting rod pin is sandwiched between the screw and the second elastic member.

8. A shock absorber according to any one of claims 1-7, wherein the damping unit further includes an oil seal seat for connecting the first inner tube and the second inner tube, the pressure relief passage passes through the oil seal seat to communicate the second chamber with the inner space, and the pressure relief stop member is fixedly sleeved on the second inner tube to normally cover and stop the opening of the pressure relief passage.

9. The shock absorber according to claim 8, wherein the pressure-releasing stopper assembly includes a positioning sleeve and a plurality of second thin plates disposed in a stacked manner, the plurality of second thin plates are sleeved on the second inner cylinder for covering and stopping the opening of the pressure-releasing passage, the positioning sleeve is screwed on the second inner cylinder, and the plurality of second thin plates are clamped between the positioning sleeve and the oil seal seat.

10. The shock absorber according to claim 7, wherein the damping unit further comprises an air adjusting mechanism, the air adjusting mechanism comprises an air passage and an air valve, the air passage is disposed in the first inner cylinder to communicate with the outside and the air chamber, the air valve is disposed in the air passage to selectively block the air chamber from communicating with the outside; the oil through valve body is provided with a first side part facing the air storage chamber, a second side part facing the second inner cylinder, and a plurality of compression flow passages and a plurality of rebound flow passages which axially penetrate through the oil through valve body, the plurality of compression flow passages and the plurality of rebound flow passages are alternately arranged along the circumferential direction and are not communicated with each other, a first covering component is arranged on the first side part and only covers the plurality of compression flow passages but not the plurality of rebound flow passages, a second covering component is arranged on the second side part and only covers the plurality of rebound flow passages but not the plurality of compression flow passages, the second covering component is provided with a first elastic piece, a base and a valve plate, the base is positioned on the communicating pipe, the valve plate is movably sleeved on the communicating pipe, the first elastic piece elastically abuts between the base and the valve plate, and the valve plate normally covers the plurality of rebound flow passages; wherein, when the shock absorber is compressed and the oil body reaches a predetermined pressure, the oil body moves towards the direction of the air storage chamber to push the first covering component to open, and the oil body can enter the oil chamber through the plurality of compression runners and the communicating pipe; when the shock absorber is extended, the oil body moves towards the direction far away from the air storage chamber to push the second cover component to open, and the oil body can flow back to the second inner cylinder through the plurality of rebound runners and the communicating pipe; the shock absorber also comprises an exhaust component, the exhaust component is provided with an exhaust channel and a stopper, the exhaust channel penetrates through the first inner cylinder, the exhaust channel is communicated with the inner space, and the stopper is arranged in the exhaust channel and used for blocking the exhaust channel from being communicated with the outside; the damping unit further comprises an oil seal seat, the oil seal seat is used for connecting the first inner cylinder and the second inner cylinder, the pressure relief channel penetrates through the oil seal seat to communicate the second chamber with the inner space, and the pressure relief stopping component is fixedly sleeved on the second inner cylinder to normally cover and stop an opening of the pressure relief channel; the number of the at least one fluid channel is two; the communicating pipe is arranged in the first inner cylinder; the radial dimension of the first outer tube is larger than that of the second outer tube; the first inner cylinder is screwed on the first outer pipe; the first covering member includes a plurality of first sheets arranged in a stacked configuration; the pressure relief and blocking assembly comprises a positioning sleeve and a plurality of second sheets arranged in a stacked manner, the second sheets are sleeved on the second inner cylinder and used for covering and blocking the opening of the pressure relief channel, the positioning sleeve is screwed on the second inner cylinder, and the second sheets are clamped between the positioning sleeve and the oil seal seat.

Images