CN117605732A

CN117605732A - Hydraulic cylinder

Info

Publication number: CN117605732A
Application number: CN202410079026.3A
Authority: CN
Inventors: 曲广军; 曲亚男; 曲文韬
Original assignee: Laizhou Jinhengda Machinery Co ltd
Current assignee: Laizhou Jinhengda Machinery Co ltd
Priority date: 2024-01-19
Filing date: 2024-01-19
Publication date: 2024-02-27
Anticipated expiration: 2044-01-19
Also published as: CN117605732B

Abstract

The invention relates to the technical field of hydraulic cylinders, and discloses a hydraulic cylinder which comprises a hydraulic jacking unit, an auxiliary supporting unit, a pressure relief protection unit and an oil way control unit. The hydraulic jacking unit mainly plays a role in hydraulic support, the cavity in the auxiliary supporting unit can push the oil way control unit to be opened in the working process of the hydraulic jacking unit, hydraulic oil is conveyed into the auxiliary supporting unit, the purpose of auxiliary support is achieved, after the pressure relief condition occurs, the whole oil way control unit is locked through the pressure relief protection unit, and the pressure relief cannot occur in the auxiliary supporting unit at the moment, so that the purpose of continuous jacking can be achieved, stable work of the hydraulic jacking unit is guaranteed, safety in the working process is improved, and the hydraulic jacking unit is suitable for wide popularization and use.

Description

Hydraulic cylinder

Technical Field

The invention belongs to the technical field of hydraulic cylinders, and particularly relates to a hydraulic cylinder.

Background

The hydraulic cylinder is a hydraulic actuator that converts hydraulic energy into mechanical energy and performs linear reciprocating motion (or swinging motion). The hydraulic system is simple in structure and reliable in operation, and is widely applied to hydraulic systems of various machines. The output force of the hydraulic cylinder is in direct proportion to the effective area of the piston and the pressure difference between two sides of the effective area of the piston; the hydraulic cylinder basically consists of a cylinder barrel, a cylinder cover, a piston rod, a sealing gasket and the like.

Some occasions need to adopt high-pressure and high-flow hydraulic cylinders based on the requirements of actual engineering, the load to be lifted by the hydraulic cylinders is generally quite large, but in the use process, sometimes pressure relief situations can occur along with the aging of instruments, in a working state, the pressure relief situations can cause unbalance of the internal pressure of the cylinders, the piston rod is caused to rapidly move towards the load direction, finally, the lifted load can be caused to suddenly fall, the possibility of injuring people is provided, and potential safety hazards exist.

The present invention has been made in view of this.

Disclosure of Invention

In order to solve the technical problems, the invention adopts the basic conception of the technical scheme that:

a hydraulic cylinder comprises a hydraulic jacking unit, an auxiliary supporting unit, a pressure relief protection unit and an oil way control unit;

the hydraulic jacking unit comprises a cylinder barrel, an oil inlet and an oil outlet are respectively formed in the side wall of the cylinder barrel, the oil outlet is arranged above the oil inlet, a cylinder seat is arranged at the bottom of the cylinder barrel, a cylinder cover is arranged above the cylinder barrel, a piston is slidably arranged in the cylinder barrel, a piston rod is vertically arranged at the top of the piston, and the piston rod movably penetrates through the cylinder cover;

the auxiliary supporting unit comprises an auxiliary sleeve, a sliding plate is slidably arranged in the auxiliary sleeve, a push rod is arranged at the top of the sliding plate, the push rod movably penetrates through the top of the auxiliary sleeve, the push rod is fixedly sleeved with the piston rod, a connecting pipe is arranged on the side wall of the auxiliary sleeve, and the connecting pipe is mutually communicated with the cylinder barrel;

the oil way control unit comprises a sealing ball which is clamped on the inner wall of the connecting pipe;

the pressure relief protection unit comprises a pressure relief pipe, wherein a vertical rod is movably inserted in the pressure relief pipe, the vertical rod movably penetrates through the inner wall of the connecting pipe, and the vertical rod positioned in the connecting pipe is in sliding connection with the sealing ball.

As a preferable implementation mode of the invention, the bottom of the cylinder seat is vertically provided with the connecting ring, the top of the cylinder seat is clamped and provided with the sealing gasket, the sealing gasket is tightly attached to the bottom of the cylinder barrel, the side wall of the cylinder cover is provided with the locking bolt, the locking bolt movably penetrates through the side wall of the cylinder cover and the mounting lug at the top of the cylinder barrel, and the tail end of the locking bolt is screwed and provided with the nut.

As a preferred implementation mode of the invention, the side wall of the piston is separately provided with two grooves, a sealing ring and a guide supporting ring are respectively embedded in the two grooves, the sealing ring and the guide supporting ring are in sliding connection with the inside of the cylinder barrel, the height of the sealing ring is lower than that of the guide supporting ring, and the top of the piston rod is provided with a hanging ring.

As a preferred implementation mode of the invention, the top of the piston is surrounded by the cylinder cover and the inner wall of the cylinder barrel to form an oil outlet cavity, the oil outlet cavity is communicated with the oil outlet, the bottom of the piston is surrounded by the cylinder seat and the inner wall of the cylinder barrel to form an oil inlet cavity, the oil inlet cavity is communicated with the oil inlet, the oil inlet cavity is communicated with the connecting pipe, an elbow is arranged on the side wall of the oil outlet cavity, a pressure relief pipe is arranged at the bottom of the elbow, and the pressure relief pipe is communicated with the oil outlet cavity.

As a preferred implementation mode of the invention, the top of the ejector rod is fixedly provided with the connecting rod, the tail end of the connecting rod is provided with the synchronous sleeve ring, the synchronous sleeve ring is sleeved on the outer side of the piston rod, the synchronous sleeve ring and the outer wall of the piston are mutually welded, the bottom of the auxiliary sleeve is welded on the outer surface of the cylinder seat, and the ejector rod and the piston rod have the same length.

In a preferred embodiment of the present invention, the connecting pipe is internally provided with a small-caliber passage and a large-caliber passage, the small-caliber passage and the large-caliber passage are mutually communicated, the small-caliber passage and the oil inlet cavity are mutually communicated, the large-caliber passage and the auxiliary sleeve cavity are mutually communicated, the sealing ball is blocked at the joint of the small-caliber passage and the large-caliber passage, and the diameter of the sealing ball is larger than that of the small-caliber passage and smaller than that of the large-caliber passage.

As a preferred implementation mode of the invention, the sealing ball is fixedly provided with the inserted link, the outer wall of the inserted link is slidably provided with the cross connecting bracket, the cross connecting bracket is welded on the inner wall of the large-caliber passage, the center of the outer wall of the cross connecting bracket is provided with the positioning sleeve, and the inner cavity of the positioning sleeve is movably inserted with the inserted link.

As a preferred implementation mode of the invention, a mounting cavity is formed in the positioning sleeve, a baffle is slidably mounted in the mounting cavity, a plug rod is mounted on one side of the baffle, an extrusion spring is mounted on the other side of the baffle, and the tail end of the extrusion spring is fixedly mounted on the inner wall of the positioning sleeve.

As a preferred implementation mode of the invention, the center of the sealing ball is provided with an inner groove, the inner walls of the two sides of the inner groove are provided with guide sliding grooves, the guide sliding grooves are in an inclined state, the tail ends of the guide sliding grooves close to the auxiliary sleeve are higher than the other side, guide rods are slidably arranged in the guide sliding grooves, guide blocks are fixedly arranged at the tail ends of the guide rods, the guide blocks slide in the inner groove, and vertical rods are arranged at the tops of the guide blocks.

As a preferred implementation mode of the invention, the tail end of the vertical rod positioned in the pressure relief pipe is provided with the pressing plate, the pressing plate is tightly attached to the interior of the pressure relief pipe, the outer wall of the vertical rod positioned in the pressure relief pipe is sleeved with the return spring, one side tail end of the return spring is clamped at the bottom of the pressing plate, and the other side tail end of the return spring is clamped at the inner wall of the pressure relief pipe.

Compared with the prior art, the invention has the beneficial effects that:

through being provided with hydraulic jacking unit, auxiliary stay unit, pressure release protection unit and oil circuit control unit, wherein hydraulic jacking unit has mainly played hydraulic support's effect, the inside cavity of auxiliary stay unit can be in hydraulic jacking unit course of working, promote the oil circuit control unit and open, carry the auxiliary stay unit inside with hydraulic oil, the purpose of auxiliary stay has been played, after the pressure release condition takes place, lock the oil circuit control unit is whole to be dead through the pressure release protection unit, and the pressure release will not take place in the auxiliary stay unit inside this moment, thereby can reach the purpose of lasting jacking, and then guaranteed the work that hydraulic jacking unit can be stable, the security in the course of the work has been improved.

The following describes the embodiments of the present invention in further detail with reference to the accompanying drawings.

Drawings

In the drawings:

FIG. 1 is a schematic three-dimensional structure of a hydraulic cylinder;

FIG. 2 is a bottom view of a hydraulic ram;

FIG. 3 is a partial cross-sectional view of a hydraulic ram;

FIG. 4 is a partial cross-sectional view of a hydraulic ram;

FIG. 5 is an enlarged view of the hydraulic ram at A of FIG. 4;

FIG. 6 is an enlarged view of the hydraulic ram at B of FIG. 4;

fig. 7 is a cross-sectional view of a sealing ball of a hydraulic ram.

In the figure:

100. a hydraulic jacking unit; 101. a cylinder; 1011. an oil inlet; 1012. an oil outlet; 1013. an oil inlet cavity; 1014. an oil outlet cavity; 102. a cylinder base; 1021. a connecting ring; 1022. a sealing gasket; 103. a cylinder cover; 1031. a locking bolt; 104. a piston rod; 1041. a hanging ring; 1042. a piston; 1043. a seal ring; 1044. a guide support ring;

200. an auxiliary supporting unit; 201. an auxiliary sleeve; 2011. a connecting pipe; 2012. a small-bore passageway; 2013. a large-caliber passage; 202. a push rod; 2021. a slide plate; 2022. a connecting rod; 2023. a synchronization collar;

300. a pressure relief protection unit; 301. a pressure relief tube; 3011. an elbow; 302. a pressing plate; 3021. a vertical rod; 3022. a return spring; 303. a guide block; 3031. a guide rod;

400. an oil path control unit; 401. a sealing ball; 4011. an inner groove; 4012. a guide chute; 402. a rod; 4021. a cross connecting bracket; 4022. a baffle; 403. a positioning sleeve; 4031. the spring is pressed.

Detailed Description

For the purpose of making the objects, technical solutions and advantages of the embodiments of the present invention more apparent, the technical solutions in the embodiments will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and the following embodiments are used to illustrate the present invention.

Embodiment one:

as shown in fig. 1 to 7, a hydraulic cylinder includes a hydraulic jacking unit 100, an auxiliary supporting unit 200, a pressure relief protection unit 300, and an oil path control unit 400;

the hydraulic jacking unit 100 comprises a cylinder 101, an oil inlet 1011 and an oil outlet 1012 are respectively formed in the side wall of the cylinder 101, the oil outlet 1012 is arranged above the oil inlet 1011, a cylinder seat 102 is arranged at the bottom of the cylinder 101, a cylinder cover 103 is arranged above the cylinder 101, a piston 1042 is slidably arranged in the cylinder 101, a piston rod 104 is vertically arranged at the top of the piston 1042, and the piston rod 104 movably penetrates through the cylinder cover 103;

the auxiliary supporting unit 200 comprises an auxiliary sleeve 201, a sliding plate 2021 is slidably arranged in the auxiliary sleeve 201, a top rod 202 is arranged at the top of the sliding plate 2021, the top rod 202 movably penetrates through the top of the auxiliary sleeve 201, the top rod 202 is fixedly sleeved with the piston rod 104, a connecting pipe 2011 is arranged on the side wall of the auxiliary sleeve 201, and the connecting pipe 2011 is mutually communicated with the cylinder 101;

the oil circuit control unit 400, the oil circuit control unit 400 comprises a sealing ball 401, and the sealing ball 401 is clamped on the inner wall of the connecting pipe 2011;

the pressure relief protection unit 300, the pressure relief protection unit 300 includes pressure relief pipe 301, and the inside activity of pressure relief pipe 301 is pegged graft and is had montant 3021, and montant 3021 activity runs through connecting pipe 2011 inner wall, and is located the inside montant 3021 of connecting pipe 2011 and sealing ball 401 sliding connection.

Through being provided with hydraulic jacking unit 100, auxiliary stay unit 200, pressure release protection unit 300 and oil circuit control unit 400, wherein hydraulic jacking unit 100 mainly plays the effect of hydraulic support, the inside cavity of auxiliary stay unit 200 can be in hydraulic jacking unit 100 course of working, promote oil circuit control unit 400 and open, carry the inside auxiliary stay unit 200 with the hydraulic oil, the purpose of auxiliary stay has been played, and after the pressure release condition takes place, lock the oil circuit control unit 400 wholly through pressure release protection unit 300, and pressure release will not take place in the auxiliary stay unit 200 inside this moment, thereby can reach the purpose of lasting jacking, and then guaranteed that hydraulic jacking unit 100 can stable work, the security in the course of working has been improved.

As shown in fig. 1 to 7, in a specific embodiment, a connecting ring 1021 is vertically installed at the bottom of a cylinder seat 102, a sealing pad 1022 is installed at the top of the cylinder seat 102 in a clamping manner, the sealing pad 1022 is tightly attached to the bottom of a cylinder barrel 101, a locking bolt 1031 is installed on the side wall of a cylinder cover 103, the locking bolt 1031 movably penetrates through the side wall of the cylinder cover 103 and a mounting lug at the top of the cylinder barrel 101, and nuts are screwed at the tail ends of the locking bolts 1031. The sealing gasket 1022 improves the sealing performance of the cylinder 101, and the locking bolt 1031 facilitates the later opening of the sealed cylinder 101, and the later maintenance.

As shown in fig. 1 to 7, further, two grooves are separately provided on the side wall of the piston 1042, a sealing ring 1043 and a guiding support ring 1044 are respectively embedded in the two grooves, the sealing ring 1043 and the guiding support ring 1044 are slidably connected with the cylinder 101, the height of the sealing ring 1043 is lower than the height of the guiding support ring 1044, and a hanging ring 1041 is installed on the top of the piston rod 104. The hydraulic oil is injected into the oil inlet 1011 through the hydraulic pump, the hydraulic oil enters the oil inlet 1013 through the oil inlet 1011, the piston 1042 is pushed to move upwards along with the gradual increase of the hydraulic oil in the oil inlet 1013, the piston 1042 moves upwards, the piston rod 104 at the top is pushed to move upwards, the purpose of jacking load is achieved, the sealing ring 1043 and the guide support ring 1044 on the surface of the piston 1042 play a role in sealing and supporting, and the piston 1042 moves upwards, so that the hydraulic oil in the oil outlet 1014 at the top is pushed to be discharged from the oil outlet 1012.

Embodiment two:

the difference from this embodiment based on the above embodiment is that:

as shown in fig. 1 to 7, the top of the piston 1042 surrounds the cylinder head 103 and the inner wall of the cylinder 101 to form an oil outlet chamber 1014, the oil outlet chamber 1014 communicates with an oil outlet 1012, the bottom of the piston 1042 surrounds the cylinder seat 102 and the inner wall of the cylinder 101 to form an oil inlet chamber 1013, the oil inlet chamber 1013 communicates with the oil inlet 1011, the oil inlet chamber 1013 communicates with a connecting pipe 2011, an elbow 3011 is mounted on the side wall of the oil outlet chamber 1014, a pressure relief pipe 301 is mounted at the bottom of the elbow 3011, and the pressure relief pipe 301 communicates with the oil outlet chamber 1014.

As shown in fig. 1 to 7, in a specific embodiment, a connecting rod 2022 is fixedly installed at the top of the ejector rod 202, a synchronizing collar 2023 is installed at the end of the connecting rod 2022, the synchronizing collar 2023 is sleeved outside the piston rod 104, the synchronizing collar 2023 and the outer wall of the piston 1042 are welded to each other, the bottom of the auxiliary sleeve 201 is welded and installed on the outer surface of the cylinder seat 102, and the length of the ejector rod 202 is the same as that of the piston rod 104. Meanwhile, when the hydraulic oil pushes the piston 1042 to move upwards, the pressure in the oil inlet cavity 1013 is gradually increased, so that the jacking sealing ball 401 moves outwards, when the sealing ball 401 moves outwards, the joint of the small-caliber passage 2012 and the large-caliber passage 2013 of the connecting pipe 2011 is opened, a part of hydraulic oil enters the auxiliary sleeve 201 from the connecting pipe 2011, the sliding plate 2021 in the auxiliary sleeve 201 moves upwards, the ejector rod 202, the connecting rod 2022 and the synchronizing sleeve 2023 at the top are pushed to push the piston rod 104 to move upwards in an auxiliary manner, and the purpose of assisting the piston rod 104 to move is achieved.

As shown in fig. 1 to 7, further, a small-caliber passageway 2012 and a large-caliber passageway 2013 are arranged inside the connecting pipe 2011, the small-caliber passageway 2012 and the large-caliber passageway 2013 are communicated with each other, the small-caliber passageway 2012 and the oil inlet cavity 1013 are communicated with each other, the large-caliber passageway 2013 and the inner cavity of the auxiliary sleeve 201 are communicated with each other, the sealing ball 401 is blocked at the joint of the small-caliber passageway 2012 and the large-caliber passageway 2013, the diameter of the sealing ball 401 is larger than the diameter of the small-caliber passageway 2012 and smaller than the diameter of the large-caliber passageway 2013, and the sealing operation on the connecting pipe 2011 can be completed through the sealing ball 401.

Embodiment III:

the difference from this embodiment based on the above embodiment is that:

as shown in fig. 1 to 7, an insert rod 402 is fixedly installed on a sealing ball 401, a cross connecting bracket 4021 is slidably installed on the outer wall of the insert rod 402, the cross connecting bracket 4021 is welded on the inner wall of a large-caliber passageway 2013, a positioning sleeve 403 is installed in the center of the outer wall of the cross connecting bracket 4021, and the inner cavity of the positioning sleeve 403 is movably inserted with the insert rod 402. The locating sleeve 403 is internally provided with a mounting cavity, a baffle 4022 is slidably mounted in the mounting cavity, an inserting rod 402 is mounted on one side of the baffle 4022, an extrusion spring 4031 is mounted on the other side of the baffle 4022, and the tail end of the extrusion spring 4031 is fixedly mounted on the inner wall of the locating sleeve 403. When the sealing ball 401 moves outwards, the inserted link 402 moves towards the inside of the positioning sleeve 403, the compression spring 4031 in the positioning sleeve 403 is pushed to compress, and after the hydraulic pressure is balanced through the compression spring 4031, the sealing ball 401 is pushed again through the compression spring 4031 to seal the connecting pipe 2011.

As shown in fig. 1 to 7, in a specific embodiment, an inner groove 4011 is formed in the center of the sealing ball 401, guide sliding grooves 4012 are formed in inner walls of two sides of the inner groove 4011, the guide sliding grooves 4012 are in an inclined state, the tail end of each guide sliding groove 4012 close to the auxiliary sleeve 201 is higher than the other side, a guide rod 3031 is slidably mounted in each guide sliding groove 4012, a guide block 303 is fixedly mounted at the tail end of each guide rod 3031, the guide blocks 303 slide in the inner groove 4011, and vertical rods 3021 are mounted at the tops of the guide blocks 303. The clamp plate 302 is installed to the montant 3021 end that is located pressure release pipe 301 inside, and clamp plate 302 closely laminates with pressure release pipe 301 inside, and reset spring 3022 has been cup jointed to the montant 3021 outer wall that is located pressure release pipe 301 inside, and reset spring 3022 one side end joint is in clamp plate 302 bottom, and opposite side end joint is at pressure release pipe 301 inner wall. The pressure plate 302 at the bottom of the pressure relief pipe 301 moves downwards, the pressure plate 302 moves downwards, the vertical rod 3021 at the bottom is pushed to move downwards synchronously, the guide block 303 and the guide rod 3031 slide on the inclined guide chute 4012, the sealing ball 401 is pushed to move rightwards, the cylinder 101 of the hydraulic jacking unit 100 and the connecting pipe 2011 of the auxiliary supporting unit 200 are communicated with each other, and hydraulic oil in the oil inlet 1013 and the connecting pipe 2011 can be discharged from the oil inlet 1011 by pushing, so that the piston 1042 can move downwards conveniently, and the initial state is restored.

The implementation principle of the hydraulic cylinder of the embodiment is as follows:

when the device is needed to be used, firstly, a load is installed on the lifting ring 1041, the connecting ring 1021 is fixed on the supporting frame, when the load is needed to be lifted, hydraulic oil is firstly injected into the oil inlet 1011 through the hydraulic pump, the hydraulic oil enters the oil inlet 1013 through the oil inlet 1011, the piston 1042 is pushed to move upwards along with the gradual increase of the hydraulic oil in the oil inlet 1013, the piston 1042 moves upwards, the piston rod 104 at the top is pushed to move upwards, the purpose of lifting the load is achieved, the sealing ring 1043 and the guide supporting ring 1044 on the surface of the piston 1042 play a role of sealing and supporting, and the piston 1042 moves upwards, so that the hydraulic oil in the oil outlet 1014 at the top is pushed to be discharged from the oil outlet 1012.

Meanwhile, when the hydraulic oil pushes the piston 1042 to move upwards, the pressure in the oil inlet cavity 1013 is gradually increased, so that the lifting sealing ball 401 moves outwards, when the sealing ball 401 moves outwards, the joint of the small-caliber passage 2012 and the large-caliber passage 2013 of the connecting pipe 2011 is opened, a part of hydraulic oil enters the auxiliary sleeve 201 from the connecting pipe 2011, the sliding plate 2021 in the auxiliary sleeve 201 moves upwards, the push rod 202 at the top, the connecting rod 2022 and the synchronizing sleeve 2023 push the piston rod 104 to assist to move upwards, the purpose of assisting the piston rod 104 to move is achieved, and when the sealing ball 401 moves outwards, the push rod 402 moves inwards to the positioning sleeve 403, the compression spring 4031 in the positioning sleeve 403 is pushed to compress, and after hydraulic balance, the sealing ball 401 is pushed again to seal the connecting pipe 2011 through the compression spring 4031.

After the pressure of the oil inlet 1011 at the bottom of the later stage is relieved, the hydraulic oil in the oil inlet chamber 1013 will move outwards from the oil inlet 1011, so that the pressure in the oil inlet chamber 1013 becomes low, and the pressing spring 4031 pushes the sealing ball 401 to seal the hydraulic oil injected into the auxiliary supporting unit 200 at this time, although the hydraulic oil in the oil inlet chamber 1013 is discharged, the piston rod 104 has a downward movement trend, and the ejector rod 202 of the auxiliary supporting unit 200 fixed on the side wall of the piston rod 104 has a downward movement trend synchronously, but the hydraulic passage in the auxiliary supporting unit 200 is blocked, so that the hydraulic passage cannot descend, and a protection effect is achieved.

When the piston rod 104 is normally pushed to move downwards, high-pressure hydraulic oil needs to be injected into the oil outlet 1012, the hydraulic oil moves to the oil outlet 1014, so that the pressure in the oil outlet 1014 is increased, the piston 1042 at the bottom of the oil outlet 1014 is pushed to have a downward movement trend, the oil outlet 1014 is communicated with a cavity in the pressure relief pipe 301, the pressure plate 302 at the bottom of the pressure relief pipe 301 is pushed to move downwards, the pressure plate 302 is pushed to move downwards, the vertical rod 3021 at the bottom is pushed to move downwards synchronously, the guide block 303 and the guide rod 3031 slide on the inclined guide chute 4012, the sealing ball 401 is pushed to move rightwards, the cylinder 101 of the hydraulic jacking unit 100 and the connecting pipe 2011 of the auxiliary supporting unit 200 are communicated with each other, and the hydraulic oil in the oil inlet 1013 and the connecting pipe 2011 is pushed to be discharged from the oil inlet 1011, so that the piston 1042 is convenient to move downwards, and the initial state is restored.

The foregoing has shown and described the basic principles and main features of the present invention and the advantages of the present invention. It will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, and that the above embodiments and descriptions are merely illustrative of the principles of the present invention, and various changes and modifications may be made without departing from the spirit and scope of the invention, which is defined in the appended claims. The scope of the invention is defined by the appended claims and equivalents thereof.

Claims

1. The utility model provides a hydraulic cylinder, includes hydraulic pressure jacking unit (100), auxiliary stay unit (200), pressure release protection unit (300) and oil circuit control unit (400), its characterized in that:

the hydraulic jacking unit (100) comprises a cylinder barrel (101), an oil inlet (1011) and an oil outlet (1012) are respectively formed in the side wall of the cylinder barrel (101), the oil outlet (1012) is arranged above the oil inlet (1011), a cylinder seat (102) is arranged at the bottom of the cylinder barrel (101), a cylinder cover (103) is arranged above the cylinder barrel (101), a piston (1042) is slidably arranged in the cylinder barrel (101), a piston rod (104) is vertically arranged at the top of the piston (1042), and the piston rod (104) movably penetrates through the cylinder cover (103);

the auxiliary supporting unit (200) comprises an auxiliary sleeve (201), a sliding plate (2021) is slidably arranged in the auxiliary sleeve (201), a top rod (202) is arranged at the top of the sliding plate (2021), the top rod (202) movably penetrates through the top of the auxiliary sleeve (201), the top rod (202) is fixedly sleeved with the piston rod (104), a connecting pipe (2011) is arranged on the side wall of the auxiliary sleeve (201), and the connecting pipe (2011) is mutually communicated with the cylinder barrel (101);

the oil circuit control unit (400) comprises a sealing ball (401), and the sealing ball (401) is clamped on the inner wall of the connecting pipe (2011);

the pressure relief protection unit (300) comprises a pressure relief pipe (301), wherein a vertical rod (3021) is movably inserted into the pressure relief pipe (301), the vertical rod (3021) movably penetrates through the inner wall of the connecting pipe (2011), and the vertical rod (3021) positioned in the connecting pipe (2011) is in sliding connection with the sealing ball (401).

2. The hydraulic cylinder according to claim 1, wherein a connecting ring (1021) is vertically installed at the bottom of the cylinder seat (102), a sealing pad (1022) is installed at the top of the cylinder seat (102) in a clamping manner, the sealing pad (1022) is tightly attached to the bottom of the cylinder barrel (101), a locking bolt (1031) is installed on the side wall of the cylinder cover (103), the locking bolt (1031) movably penetrates through the side wall of the cylinder cover (103) and an installation lug at the top of the cylinder barrel (101), and nuts are installed at the tail ends of the locking bolts (1031) in a threaded screwing manner.

3. The hydraulic cylinder according to claim 1, wherein two grooves are separately formed in the side wall of the piston (1042), a sealing ring (1043) and a guiding support ring (1044) are respectively embedded in the two grooves, the sealing ring (1043) and the guiding support ring (1044) are slidably connected with the cylinder (101), the height of the sealing ring (1043) is lower than that of the guiding support ring (1044), and a hanging ring (1041) is mounted on the top of the piston rod (104).

4. The hydraulic cylinder according to claim 1, wherein the top of the piston (1042) is surrounded by the cylinder cover (103) and the inner wall of the cylinder barrel (101) to form an oil outlet cavity (1014), the oil outlet cavity (1014) is communicated with an oil outlet (1012), the bottom of the piston (1042) is surrounded by the cylinder seat (102) and the inner wall of the cylinder barrel (101) to form an oil inlet cavity (1013), the oil inlet cavity (1013) is communicated with an oil inlet (1011), the oil inlet cavity (1013) is communicated with a connecting pipe (2011), an elbow (3011) is mounted on the side wall of the oil outlet cavity (1014), a pressure relief pipe (301) is mounted on the bottom of the elbow (3011), and the pressure relief pipe (301) is communicated with the oil outlet cavity (1014).

5. The hydraulic cylinder according to claim 1, wherein a connecting rod (2022) is fixedly installed at the top of the ejector rod (202), a synchronizing collar (2023) is installed at the tail end of the connecting rod (2022), the synchronizing collar (2023) is sleeved on the outer side of the piston rod (104), the synchronizing collar (2023) is welded with the outer wall of the piston (1042), the bottom of the auxiliary sleeve (201) is welded and installed on the outer surface of the cylinder seat (102), and the ejector rod (202) and the piston rod (104) are the same in length.

6. The hydraulic cylinder according to claim 4, wherein a small-caliber passage (2012) and a large-caliber passage (2013) are arranged inside the connecting pipe (2011), the small-caliber passage (2012) and the large-caliber passage (2013) are communicated with each other, the small-caliber passage (2012) and the oil inlet cavity (1013) are communicated with each other, the large-caliber passage (2013) and the inner cavity of the auxiliary sleeve (201) are communicated with each other, the sealing ball (401) is blocked at the joint of the small-caliber passage (2012) and the large-caliber passage (2013), and the diameter of the sealing ball (401) is larger than that of the small-caliber passage (2012) and smaller than that of the large-caliber passage (2013).

7. The hydraulic cylinder according to claim 6, wherein the sealing ball (401) is fixedly provided with a plunger (402), the outer wall of the plunger (402) is slidably provided with a cross connecting bracket (4021), the cross connecting bracket (4021) is welded on the inner wall of the large-caliber passageway (2013), the center of the outer wall of the cross connecting bracket (4021) is provided with a positioning sleeve (403), and the inner cavity of the positioning sleeve (403) is movably inserted into the plunger (402).

8. The hydraulic cylinder according to claim 7, wherein a mounting cavity is formed in the positioning sleeve (403), a baffle plate (4022) is slidably mounted in the mounting cavity, a plunger (402) is mounted on one side of the baffle plate (4022), a compression spring (4031) is mounted on the other side of the baffle plate (4022), and the tail end of the compression spring (4031) is fixedly mounted on the inner wall of the positioning sleeve (403).

9. The hydraulic cylinder according to claim 1, wherein an inner groove (4011) is formed in the center of the sealing ball (401), guide sliding grooves (4012) are formed in inner walls of two sides of the inner groove (4011), the guide sliding grooves (4012) are in an inclined state, the tail end of each guide sliding groove (4012) close to the auxiliary sleeve (201) is higher than the other side, guide rods (3031) are slidably mounted in the guide sliding grooves (4012), guide blocks (303) are fixedly mounted at the tail ends of the guide rods (3031), the guide blocks (303) slide in the inner groove (4011), and vertical rods (3021) are mounted at the tops of the guide blocks (303).

10. The hydraulic cylinder according to claim 1, wherein a pressing plate (302) is mounted at the tail end of a vertical rod (3021) inside the pressure relief pipe (301), the pressing plate (302) is tightly attached to the inside of the pressure relief pipe (301), a return spring (3022) is sleeved on the outer wall of the vertical rod (3021) inside the pressure relief pipe (301), one side tail end of the return spring (3022) is clamped at the bottom of the pressing plate (302), and the other side tail end of the return spring is clamped on the inner wall of the pressure relief pipe (301).