Novel multi-stage yielding anti-scour device

Abstract

The utility model discloses a novel multi-stage yielding anti-impact device, and belongs to the technical field of coal mine safety support. The multi-stage yielding anti-scour device comprises an anti-scour device body, a multi-stage yielding device body and a base, the multi-stage yielding device body is installed on the base, and the anti-scour device body is arranged above the multi-stage yielding device body; the anti-scour device comprises an anti-deviation component, the bottom of the single hydraulic prop is placed in an insertion hole of the anti-deviation component, and a protection base plate and an energy absorption component are arranged at the bottom of the anti-deviation component. The multistage yielding device comprises an outer cylinder body, a middle cylinder body and a piston, the middle cylinder body is arranged in an inner cavity of the outer cylinder body, the piston is arranged in an inner cavity of the middle cylinder body, a first oil inlet cavity is formed between the middle cylinder body and the outer cylinder body, and a second oil inlet cavity is formed between the piston and the middle cylinder body. According to the utility model, the impact prevention can be carried out under the impact dynamic load disturbance influence, and the multi-stage yielding can be realized when the pressure is generated, so that the roof caving of the roadway roof caused by the damage of the single hydraulic prop is avoided.

Description

Technical Field

[0001] The utility model relates to the technical field of coal mine safety support, in particular to a novel multi-stage pressure relief and anti-collision device. Background Art

[0002] Rock burst is one of the most typical dynamic disasters in coal mines. With the trend of deep mining of coal resources, violent mining response is inevitable, and the frequency of rock burst disasters has increased significantly. It is a difficult problem that urgently needs to be solved in the process of safe mining in coal mines. Single hydraulic prop support is a commonly used support method in underground coal mines. It is designed with the concept of pressure-relieving and anti-impact support. It ensures the stability of the surrounding rock of the mine tunnel by releasing high stress during pressure and resisting dynamic load disturbance.

[0003] At present, single hydraulic pillars are rigid support methods. Although single hydraulic pillars have certain buffering functions during the design process, the pillars' pressure-yielding and impact-resistant capabilities are very limited. When impact ground pressure occurs, the support force cannot be actively adjusted, and active yielding and pressure-relieving cannot be performed. Under the action of strong dynamic loads, the single hydraulic pillars are easily bent and deformed, and in severe cases, the single hydraulic pillars will be damaged. Utility Model Content

[0004] Based on the above technical problems, the utility model proposes a novel multi-stage pressure-yielding and anti-collision device.

[0005] The technical solution adopted by this utility model is:

[0006] A novel multi-stage pressure-yielding and anti-collision device comprises an anti-collision device, a multi-stage pressure-yielding device and a base, wherein the multi-stage pressure-yielding device is installed on the base, and the anti-collision device is arranged above the multi-stage pressure-yielding device;

[0007] The anti-collision device comprises an anti-deflection component, which is cylindrical, and a plug hole is arranged at the center of the anti-deflection component, and the bottom of the single hydraulic support is placed in the plug hole of the anti-deflection component; a protective pad and an energy absorbing component are arranged at the bottom of the anti-deflection component;

[0008] The multi-stage pressure relief device comprises an outer cylinder, a middle cylinder and a piston, wherein the middle cylinder is placed in the inner cavity of the outer cylinder, a first thrust ring is arranged on the inner upper part of the outer cylinder, a first chamber is formed between the middle cylinder, the outer cylinder and the first thrust ring, and a first spring is arranged in the first chamber; a first oil inlet chamber is formed between the middle cylinder and the outer cylinder, the first oil inlet chamber is communicated with an oil inlet channel, and the oil inlet channel is arranged on the outer cylinder;

[0009] The piston is inserted into the inner cavity of the middle cylinder body, a second thrust ring is arranged on the inner upper part of the middle cylinder body, a second chamber is formed between the middle cylinder body, the piston and the second thrust ring, and a second spring is arranged in the second chamber; a second oil inlet chamber is formed between the piston and the middle cylinder body, the first oil inlet chamber is connected with the second oil inlet chamber through a connecting channel, the connecting channel is arranged on the middle cylinder body, and a control valve is arranged on the connecting channel; the piston is connected to the anti-collision device.

[0010] Preferably, the energy absorbing member is made of energy absorbing material; two protection pads are provided, namely a first protection pad and a second protection pad, and the energy absorbing member is provided between the first protection pad and the second protection pad.

[0011] Preferably, the anti-deflection member, the first protection pad and the second protection pad are all made of steel material, the first protection pad is arranged above the second protection pad, and the first protection pad is connected to the anti-deflection member by welding.

[0012] Preferably, the first protection pad, the second protection pad and the energy absorbing member are all circular in cross section and have the same diameter; colloid is coated on both sides of the energy absorbing member and is bonded to the first protection pad and the second protection pad respectively.

[0013] Preferably, after the bottom of the single hydraulic prop is inserted into the insertion hole of the anti-deviation component, coal ash is filled in the gap between the single hydraulic prop and the anti-deviation component.

[0014] Preferably, the first thrust ring is fixed inside the outer cylinder body, and the second thrust ring is fixed inside the middle cylinder body;

[0015] Sealing gaskets are arranged between the middle cylinder body and the outer cylinder body, and between the middle cylinder body and the piston; dustproof gaskets are arranged between the first thrust ring and the middle cylinder body, and between the second thrust ring and the piston.

[0016] Preferably, the connecting channel and the control valve are both arranged at the bottom of the middle cylinder body;

[0017] The first oil inlet chamber and the second oil inlet chamber are also connected to a pressure relief valve.

[0018] Preferably, an end cover is provided on the top of the piston, and the second protective pad is connected to the end cover.

[0019] Preferably, a mounting hole is provided at the center of the base, and the lower part of the outer cylinder body of the multi-stage pressure-releasing device is embedded in the mounting hole of the base and fixed by welding.

[0020] Compared with the prior art, the utility model has the following beneficial technical effects:

[0021] (1) The utility model proposes a novel multi-stage pressure relief and anti-impact device, which can be used in conjunction with a single hydraulic support. When the single hydraulic support is subjected to impact ground pressure, the device starts multi-stage pressure relief and anti-impact. The multi-stage pressure relief and anti-impact can not only effectively release the high stress of the roof surrounding rock, but also protect the hydraulic support from damage when subjected to high dynamic load impact, thereby avoiding the occurrence of phenomena such as the roof falling due to damage to the single hydraulic support.

[0022] (2) The anti-collision device in the utility model can respond at the moment of pressure. The bottom of the single hydraulic support compresses the protective pad and then compresses the energy-absorbing component. The energy-absorbing component is compressed and deformed, thereby consuming the pressure and achieving a better anti-collision effect.

[0023] (3) The multi-stage pressure relief device in the utility model can perform multi-stage pressure relief after anti-collision, so that the adaptability range of the single hydraulic support is wider and the pressure relief capacity is more stable.

[0024] (4) The anti-collision device, the multi-stage pressure relief device and the base part of the utility model are connected as a unified whole. Through the cascade cooperation of the anti-collision device, the multi-stage pressure relief device and the single hydraulic support, a stable anti-collision and pressure relief effect can be achieved when the top plate is pressed, ensuring the safety of the support. Moreover, the entire device of the utility model is portable, simple to operate, easy to install and disassemble, and can be reused. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The utility model is further described below in conjunction with the accompanying drawings and specific embodiments:

[0026] Figure 1 It is a schematic diagram of the overall structure of the multi-stage pressure-yielding and anti-collision device disclosed in the embodiment of the utility model;

[0027] Figure 2 It is a schematic cross-sectional structure diagram of a multi-stage pressure-yielding and anti-collision device disclosed in an embodiment of the utility model;

[0028] Figure 3 It is a structural schematic diagram of an anti-collision device in a multi-stage pressure-yielding anti-collision device disclosed in an embodiment of the utility model;

[0029] Figure 4 It is a cross-sectional structural schematic diagram of a multi-stage pressure-releasing device in a multi-stage pressure-releasing and anti-collision device disclosed in an embodiment of the utility model;

[0030] Figure 5 It is a schematic diagram of the multi-stage pressure-relieving and anti-impact device disclosed in the embodiment of the utility model being applied to a single hydraulic support.

[0031] In the figure: 1. Anti-collision device, 2. Multi-stage pressure relief device, 3. Base, 4. Single hydraulic support;

[0032] 101. Anti-deflection member, 102. Energy absorbing member, 103. First protective pad, 104. Second protective pad, 105. Socket; 201. Outer cylinder body, 202. Middle cylinder body, 203. Piston, 204. First chamber, 205. Second chamber, 206. First thrust ring, 207. Second thrust ring, 208. End cover, 209. Dustproof gasket, 210. First spring, 211. Oil inlet, 212. Sealing gasket, 213. Control valve, 214. First oil inlet chamber, 215. Second oil inlet chamber, 216. Second spring. DETAILED DESCRIPTION

[0033] In conjunction with the accompanying drawings, a new type of multi-stage pressure-relieving and anti-collision device includes an anti-collision device 1, a multi-stage pressure-relieving device 2 and a base 3. The multi-stage pressure-relieving device 2 is installed on the base 3, the anti-collision device 1 is arranged above the multi-stage pressure-relieving device 2, and the single hydraulic support 4 is connected to the anti-collision device 1.

[0034] Among them, the bearing capacity of the anti-collision device 1 is F1, the working resistance of the multi-stage pressure-releasing device 2 is F2, and the magnitude relationship between F1 and F2 is F2>F1. The working resistance or bearing capacity F2 of the multi-stage pressure-releasing device 2 is greater than the rated working resistance F of the single hydraulic support 4. In specific applications, the bearing capacity of the above three components should be determined according to the requirements of different engineering conditions. It is recommended that the bearing capacity F2 of the multi-stage pressure-releasing device be 105% to 115% of the rated working resistance F of the single hydraulic support 4. Specifically, the bearing capacity of each component can be F2>F1=F. During the process of pressure, the anti-collision device 1 starts to work when the pressure F1 reaches the rated working resistance F of the single hydraulic support 4.

[0035] The axes of the anti-collision device 1, the multi-stage pressure-relieving device 2 and the base 3 are all on the same axis, and the devices are welded to form an integrated structure. When the roof pressure acting on the device gradually increases to the designed bearing capacity of each part, the anti-collision device and the multi-stage pressure-relieving device take effect in turn, effectively controlling the deformation of the roof surrounding rock.

[0036] Specifically, the anti-collision device 1 includes an anti-deflection component 101, which is cylindrical and has a socket 105 at the center of the anti-deflection component 101. The bottom of the single hydraulic prop 4 is inserted into the socket 105 of the anti-deflection component 101. When the bottom of the single hydraulic prop 4 is inserted into the socket of the anti-deflection component 101, if there is still a certain gap, coal ash can be filled in the gap between the single hydraulic prop 4 and the anti-deflection component 101 to eliminate the gap, so that the single hydraulic prop 4 is firmly fixed in the anti-deflection component 101. The anti-deflection component 101 can effectively prevent the single hydraulic prop 4 from being eccentrically loaded during operation. A protective pad and an energy absorbing component 102 are provided at the bottom of the anti-deflection component 101.

[0037] The energy absorbing member 102 is made of energy absorbing material. The energy absorbing member uses energy absorbing materials of different strengths according to different working conditions. There are two protection pads, namely a first protection pad 103 and a second protection pad 104, and the energy absorbing member 102 is arranged between the first protection pad 103 and the second protection pad 104.

[0038] The anti-deflection member 101, the first protection pad 103 and the second protection pad 104 are all made of steel material, the first protection pad 103 is arranged above the second protection pad 104, and the first protection pad 103 is connected to the anti-deflection member 101 by welding. The anti-deflection member 101 is mainly used to fix the bottom of the single hydraulic support 4 to prevent it from detaching and tilting during use.

[0039] The cross-sections of the first protection pad 103, the second protection pad 104 and the energy absorbing member 102 are all circular and have the same diameter. The energy absorbing member 102 can be processed into a flat cylindrical shape by energy absorbing material. Colloid is coated on both sides of the energy absorbing member 102, and is respectively bonded to the first protection pad 103 and the second protection pad 104 to form a whole. The utility model can be used to achieve an anti-collision function during a pressure process by bonding an energy absorbing material plate between the two protection pads.

[0040] The energy absorbing material in the energy absorbing member 102 may be made of foamed aluminum. When the pressure reaches the rated working resistance F of the single hydraulic support, the energy absorbing material begins to compress and deform to consume the energy during the pressure, thereby achieving the purpose of anti-impact.

[0041] The energy-absorbing material is disposable. During the process of anti-collision, if the energy-absorbing material is compressed and deformed and damaged, the staff can manually remove the energy-absorbing material, re-apply glue and install new energy-absorbing material to prepare for the next anti-collision.

[0042] The multi-stage pressure relief device comprises an outer cylinder 201, a middle cylinder 202 and a piston 203. The middle cylinder 202 is placed in the inner cavity of the outer cylinder 201. A first thrust ring 206 is arranged on the inner upper part of the outer cylinder 201. A first chamber 204 is formed between the middle cylinder 202, the outer cylinder 201 and the first thrust ring 206. A first spring 210 is arranged in the first chamber 204. A first oil inlet chamber 214 is formed between the bottom of the middle cylinder 202 and the outer cylinder 201. The first oil inlet chamber 214 is communicated with an oil inlet channel. The oil inlet channel is arranged on the outer cylinder 201. An oil inlet port 211 is arranged at the end of the oil inlet channel.

[0043] The piston 203 is placed in the inner cavity of the middle cylinder 202, and a second thrust ring 207 is provided on the inner upper part of the middle cylinder 202. A second chamber 205 is formed between the middle cylinder 202, the piston 203 and the second thrust ring 207, and a second spring 216 is provided in the second chamber 205. A second oil inlet chamber 215 is formed between the bottom of the piston 203 and the middle cylinder 202, and the first oil inlet chamber 214 is connected to the second oil inlet chamber 215 through a connecting channel, and the connecting channel is provided on the middle cylinder 202, and a control valve 213 is provided on the connecting channel. The piston 203 is connected to the anti-collision device 1.

[0044] The center of the base 3 is provided with a mounting hole, and the lower part of the outer cylinder 201 of the multi-stage pressure-releasing device is embedded in the mounting hole of the base and fixed by welding, so that the multi-stage pressure-releasing device is firmly fixed in the base. The outer diameter of the base 3 is larger than the outer diameter of the outer cylinder in the multi-stage pressure-releasing device, and the outer diameter of the base is generally 1.4 to 1.6 times the outer diameter of the outer cylinder.

[0045] The first thrust ring 206 is fixed inside the outer cylinder 201, and is used to limit and fix the middle cylinder 202 after it reaches the limit of extension. The second thrust ring 207 is fixed inside the middle cylinder 202, and moves with the movement of the middle cylinder, and is used to limit and fix the piston 203 after it reaches the limit of extension; a sealing gasket 212 is provided between the middle cylinder 202 and the outer cylinder 201, and between the middle cylinder 202 and the piston 203. A dustproof gasket 209 is provided between the first thrust ring 206 and the middle cylinder 202, and between the second thrust ring 207 and the piston 203.

[0046] The above-mentioned connecting channel and control valve 213 are both arranged at the bottom of the middle cylinder body 202. The control valve 213 is arranged between the first oil inlet chamber 214 and the second oil inlet chamber 215, and is located at the center of the bottom of the middle cylinder body 202. The control valve 213 is adjusted so that only when the middle cylinder body 202 is fully extended and the oil pressure reaches the pressure at which the control valve 213 is opened, the hydraulic oil can enter the second oil inlet chamber through the control valve 213, thereby controlling the extension of the piston 203. The first oil inlet chamber 214 and the second oil inlet chamber 215 are also connected to a pressure relief valve.

[0047] An end cap 208 is provided on the top of the piston 203, and the second protection pad 104 is connected to the end cap 208. Of course, welding can be adopted between the second protection pad and the end cap, and between the end of the piston and the end cap. The end cap 208 is also set to be circular, and the diameter is the same as the diameter of the first protection pad 103 or the second protection pad 104. In addition, the diameter of the end cap 208 is also equal to the outer diameter of the outer cylinder body 201.

[0048] In the above multi-stage pressure-releasing device, the outer cylinder 201 wraps around the middle cylinder 202 and is located at the outermost periphery of the multi-stage pressure-releasing device, which is equivalent to the outer shell of the multi-stage pressure-releasing device or the multi-stage pressure-releasing jack. The middle cylinder 202 wraps around the piston 203, and the gap between the outer cylinder 201 and the middle cylinder 202, and the gap between the middle cylinder 202 and the piston 203 are provided with sealing gaskets 212 to prevent oil leakage.

[0049] The utility model discloses a multi-stage pressure-relieving and anti-impact device which can not only prevent impact under the influence of impact dynamic load disturbance, but also realize multi-stage pressure-relieving when pressure occurs. By combining anti-impact and multi-stage pressure-relieving, the roof of the tunnel can be prevented from falling due to damage of a single hydraulic support.

[0050] The method for using the novel multi-stage pressure-releasing and anti-collision device to release pressure and prevent collision is as follows:

[0051] a. Install multi-level pressure relief and anti-collision devices;

[0052] Place the bottom of the single hydraulic support 4 into the anti-deflection component 101 of the anti-collision device 1. If there is a certain gap between the single hydraulic support 4 and the anti-deflection component 101, fill the gap with coal ash to eliminate the gap, so that the single hydraulic support 4 is firmly fixed in the anti-deflection component.

[0053] When the roof pressure acting on the device reaches the designed bearing capacity of each part, the anti-collision device 1 and the multi-stage pressure-relieving device 2 take effect in sequence, thereby effectively releasing the roof surrounding rock pressure and avoiding the crushing of the single hydraulic support column.

[0054] b. Jacking support;

[0055] After the multi-stage pressure relief anti-collision device is installed, hydraulic oil is injected into the first oil inlet chamber 214 and the second oil inlet chamber 215 by a hydraulic pump, so that the middle cylinder 202 and the piston 203 are raised in sequence. Specifically, the hydraulic oil first enters the first oil inlet chamber 214 through the oil inlet channel, and the hydraulic oil raises the middle cylinder 202 by pressure, and the first spring 210 in the first chamber 204 begins to be compressed. The middle cylinder 202 drives the piston 203, the second thrust ring 207 and the end cover 208 to rise together. After the middle cylinder 202 is extended to the limit length, the spring is compressed to the limit length, and under the action of the first thrust ring 206, the middle cylinder 202 is extended to the limit length. Continue to pressurize, and when the oil pressure reaches the opening pressure of the control valve 213, the control valve 213 is opened, and the hydraulic oil enters the second oil inlet chamber 215 through the control valve. Under the action of the oil pressure, the piston 203 begins to extend, and the piston 203 drives the end cover 208 to rise together. The second spring 216 in the second chamber 205 is continuously compressed, and under the action of the second thrust ring 207, the piston 203 is extended to a limit length, and the spring is also compressed to a limit length. The multi-stage pressure-resistance device is completed.

[0056] Subsequently, the single hydraulic prop 4 is raised so that the top of the piston 203 of the single hydraulic prop 4 contacts the top plate with a certain pressure. At this time, the whole device is in working state.

[0057] c. When the top plate comes to press, it should be allowed to press and prevent impact;

[0058] When the top plate pressure reaches the rated working resistance of the single hydraulic prop 4, the anti-collision device 1 first responds and starts to work. The bottom of the single hydraulic prop 4 compresses the protective pad, and then compresses the energy absorbing member 102, which is compressed and deformed to consume the pressure.

[0059] After the anti-collision device acts, the top plate pressure is applied to the multi-stage pressure-releasing device 2, and the multi-stage pressure-releasing device 2 starts to work, and the top plate pressure is released through multi-stage pressure relief. When the pressure is released, it is realized through the pressure relief valve connected to the first oil inlet chamber 214 and the second oil inlet chamber 215 in the multi-stage pressure-releasing device. The pressure relief valve is in a normally closed state, and the opening pressure of the pressure relief valve is designed to be F2, which is the working resistance of the multi-stage pressure-releasing device.

[0060] The working process of the multi-stage pressure relief device is as follows:

[0061] When the top plate pressure exceeds the working resistance F2 of the multi-stage pressure relief device, the pressure relief valve automatically opens. First, the oil pressure in the second oil inlet chamber 215 begins to be released, and the piston 203 begins to descend. If the top plate is not severely deformed, the pressure relief valve automatically closes after the piston 203 descends to a certain extent. If the top plate is severely deformed, after the piston is completely retracted back into the middle cylinder 202, the hydraulic oil in the first oil inlet chamber 214 is discharged through the pressure relief valve. In order to adapt to greater deformation, the middle cylinder 202 begins to descend. After descending to a certain extent, the pressure relief valve closes and stops descending, realizing multi-stage pressure relief.

[0062] d. Check and maintain the device;

[0063] After the multi-stage pressure-relieving and anti-collision device is in operation, the staff will check the equipment in time. If the energy-absorbing component 102 in the anti-collision device is damaged, the energy-absorbing component 102 will be replaced in time, and then the hydraulic oil will be re-injected to raise the multi-stage pressure-relieving device again, so that it is in working condition and prepares for the next pressure.

[0064] The utility model proposes a novel multi-stage pressure-relieving and anti-impact device, which can realize multi-stage pressure-relieving and anti-impact when a single hydraulic support encounters pressure, thereby gradually releasing the surrounding rock pressure of the tunnel roof; at the same time, it can ensure that the single hydraulic support is not damaged under the action of strong dynamic load when pressure comes, avoiding the occurrence of accidents such as roof collapse caused by damage to the single hydraulic support.

[0065] The parts not mentioned in the above methods can be realized by adopting or drawing on existing technologies.

[0066] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A new type of multi-stage pressure relief and anti-collision device, characterized in that: It includes an anti-collision device, a multi-stage pressure-releasing device and a base, the multi-stage pressure-releasing device is installed on the base, and the anti-collision device is arranged above the multi-stage pressure-releasing device; The anti-collision device comprises an anti-deflection component, which is cylindrical, and a plug hole is arranged at the center of the anti-deflection component, and the bottom of the single hydraulic support is placed in the plug hole of the anti-deflection component; a protective pad and an energy absorbing component are arranged at the bottom of the anti-deflection component; The multi-stage pressure relief device comprises an outer cylinder, a middle cylinder and a piston, wherein the middle cylinder is placed in the inner cavity of the outer cylinder, a first thrust ring is arranged on the inner upper part of the outer cylinder, a first chamber is formed between the middle cylinder, the outer cylinder and the first thrust ring, and a first spring is arranged in the first chamber; a first oil inlet chamber is formed between the middle cylinder and the outer cylinder, the first oil inlet chamber is communicated with an oil inlet channel, and the oil inlet channel is arranged on the outer cylinder; The piston is inserted into the inner cavity of the middle cylinder body, a second thrust ring is arranged on the inner upper part of the middle cylinder body, a second chamber is formed between the middle cylinder body, the piston and the second thrust ring, and a second spring is arranged in the second chamber; a second oil inlet chamber is formed between the piston and the middle cylinder body, the first oil inlet chamber is connected with the second oil inlet chamber through a connecting channel, the connecting channel is arranged on the middle cylinder body, and a control valve is arranged on the connecting channel; the piston is connected to the anti-collision device.

2. According to claim 1, the novel multi-stage pressure relief and anti-collision device is characterized in that: The energy absorbing member is made of energy absorbing material; two protection pads are provided, namely a first protection pad and a second protection pad, and the energy absorbing member is provided between the first protection pad and the second protection pad.

3. A novel multi-stage pressure relief and anti-collision device according to claim 2, characterized in that: The anti-deflection component, the first protection pad and the second protection pad are all made of steel material. The first protection pad is arranged above the second protection pad, and the first protection pad is connected to the anti-deflection component by welding.

4. A novel multi-stage pressure relief and anti-collision device according to claim 3, characterized in that: The cross sections of the first protection pad, the second protection pad and the energy absorbing member are all circular and have the same diameter; colloid is coated on both sides of the energy absorbing member and is bonded to the first protection pad and the second protection pad respectively.

5. According to the novel multi-stage pressure relief and anti-collision device of claim 1, it is characterized by: After the bottom of the single hydraulic prop is inserted into the insertion hole of the anti-deviation component, coal ash is filled in the gap between the single hydraulic prop and the anti-deviation component.

6. The novel multi-stage pressure relief and anti-collision device according to claim 1 is characterized in that: The first thrust ring is fixed inside the outer cylinder body, and the second thrust ring is fixed inside the middle cylinder body; Sealing gaskets are arranged between the middle cylinder body and the outer cylinder body, and between the middle cylinder body and the piston; dustproof gaskets are arranged between the first thrust ring and the middle cylinder body, and between the second thrust ring and the piston.

7. The novel multi-stage pressure relief and anti-collision device according to claim 1 is characterized in that: The connecting channel and the control valve are both arranged at the bottom of the middle cylinder body; The first oil inlet chamber and the second oil inlet chamber are also connected to a pressure relief valve.

8. The novel multi-stage pressure relief and anti-collision device according to claim 3 is characterized in that: An end cover is arranged on the top of the piston, and the second protection pad is connected to the end cover.

9. The novel multi-stage pressure relief and anti-collision device according to claim 1 is characterized in that: A mounting hole is arranged at the center of the base, and the lower part of the outer cylinder body of the multi-stage pressure-releasing device is embedded in the mounting hole of the base and fixed by welding.

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