Hydraulic oil cylinder with positioning mechanism

Abstract

The invention relates to the technical field of hydraulic oil cylinders, and discloses a hydraulic oil cylinder with a positioning mechanism. The hydraulic oil cylinder with the positioning mechanism is composed of a cylindrical oil cylinder shell, a piston body, a piston rod, supporting legs, a sliding sealing ring, a high-speed pushing mechanism used for pushing the hydraulic oil cylinder to be quickly positioned and the like, the high-speed pushing mechanism comprises two main cylinder bodies, and the inner diameter of each main cylinder body is far larger than the inner diameter of the oil cylinder shell. The two main cylinder bodies are respectively and directly communicated with a pushing oil cavity and a contraction oil cavity of the oil cylinder shell, and the working principle is that the two main cylinder bodies are synchronously linked to work to control pushing and pulling of a piston rod in the oil cylinder shell, so that quick positioning and clamping of a workpiece are realized; the clamp is suitable for workpiece positioning and clamping on various industrial automatic production lines. In addition, the oil cylinder further has the adjustable positioning distance, and the positioning requirements of workpieces with different lengths or diameters are met.

Description

Technical Field

[0001] The invention relates to the technical field of hydraulic cylinders, in particular to a hydraulic cylinder with a positioning mechanism. Background Art

[0002] In the field of industrial automation and mechanical manufacturing, hydraulic cylinders are important actuators and are widely used in the motion control of various mechanical equipment. Especially in automated assembly lines, hydraulic cylinders are used to perform clamping operations. The precise positioning and stability of hydraulic cylinders are essential to improving production efficiency and product quality.

[0003] However, existing hydraulic cylinders mainly use fixed stroke or manual adjustment to achieve positioning and clamping of workpieces. Fixed stroke hydraulic cylinders cannot be adjusted according to working conditions, and have a small scope of application. In addition, due to the limited oil flow and return speed, the hydraulic cylinder's liquid inlet speed is limited by the position of the pipeline and the valve core, which affects the speed of oil flow, thereby affecting the thrust and speed of the hydraulic actuator, resulting in slow positioning speed. Manual adjustment of the positioning distance is inconvenient, inefficient and low in precision.

[0004] Therefore, we propose a hydraulic cylinder with a positioning mechanism to solve the problems in the above background. Summary of the invention

[0005] The object of the present invention is to provide a hydraulic cylinder with a positioning mechanism to solve the problem that the existing hydraulic cylinders mentioned in the above background technology are inconvenient to position and are limited by the thrust and speed of the hydraulic actuators, resulting in slow positioning speed.

[0006] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0007] A hydraulic cylinder with a positioning mechanism comprises a cylinder housing, a piston body and a piston rod are arranged inside the cylinder housing, the piston body is slidably connected to the inside of the cylinder housing, a multi-layer ring groove is opened on the piston body, a sliding sealing ring is sleeved on the ring groove, and the sliding sealing ring is in contact with the inner wall of the cylinder housing. It is characterized in that: the piston body sleeved with the sliding sealing ring divides the inside of the cylinder housing into a pushing oil chamber and a contraction oil chamber; the piston body is fixedly connected to one end of the piston rod, the other end of the piston rod passes through the inside of the contraction oil chamber and extends out of the cylinder housing, and the end of the piston rod located outside the cylinder housing is connected to a mechanical clamping structure for rapid clamping and positioning of workpieces; a high-speed pushing mechanism for pushing the hydraulic cylinder for rapid positioning is arranged outside the cylinder housing.

[0008] Compared with the prior art, the beneficial effects achieved by the present invention are:

[0009] The hydraulic cylinder with a positioning mechanism of the present invention is connected to the push oil chamber of the cylinder housing 1 through the first short-stroke compression cylinder, and the second short-stroke compression cylinder is connected to the contraction oil chamber. The main cylinder diameters of the first short-stroke compression cylinder and the second short-stroke compression cylinder are much larger than the inner diameter of the cylinder housing. Through the ingenious oil supply structure and the efficient driving mechanism, the workpiece can be quickly positioned and the distance adjusted without being limited by the limitations of manual operation. Its main technical effects include: first, through the specially designed short-stroke compression cylinder and linkage mechanism, the oil supply and discharge speed of the hydraulic oil are significantly accelerated, the high-speed movement of the piston rod is promoted, and rapid clamping and positioning are achieved. Secondly, the adjustment device of the adjustable cam can accurately control the telescopic distance of the piston rod to meet the clamping requirements of different workpiece sizes, and the operation is convenient and efficient. In addition, compared with the traditional hydraulic system, the cylinder optimizes the oil flow path, reduces the oil return resistance, improves the sensitivity and accuracy, and ensures the stable and safe operation of the equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 It is a schematic diagram of the overall external structure of the present invention;

[0011] Figure 2 It is a schematic diagram of the connection structure between the C-shaped rod and the top plate of the present invention;

[0012] Figure 3 For the present invention Figure 2 A schematic diagram of the enlarged structure at point A;

[0013] Figure 4 It is a cross-sectional structural schematic diagram of the reciprocating drive source of the present invention;

[0014] Figure 5 It is a schematic diagram of the cross-sectional structure of the oil cylinder housing of the present invention;

[0015] Figure 6 For the present invention Figure 5 Schematic diagram of the enlarged structure at B.

[0016] Among them: 1. Cylinder housing; 2. Support foot; 3. Piston body; 4. Piston rod; 5. Sliding sealing ring; 6. Push oil chamber; 7. Contraction oil chamber; 8. Mechanical clamping structure; 9. Fixed support frame; 10. First clamping plate; 11. Second clamping plate; 12. First short-stroke compression cylinder; 13. Second short-stroke compression cylinder; 14. Main cylinder body; 15. Top plate; 16. Connecting rod; 17. Guide rod; 18. Drive assembly; 19. Base; 20. C-type rod; 21. Reciprocating drive source; 22. Return spring; 23. Adjustable cam; 24. Servo motor; 25. First push plate; 26. Second push plate; 27. Support plate; 28. Electric telescopic rod; 29. ​​Conductive slip ring; 30. Bump. DETAILED DESCRIPTION

[0017] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0018] Embodiment 1:

[0019] See also Figure 1-6 , the present invention provides a technical solution:

[0020] A hydraulic cylinder with a positioning mechanism comprises a cylinder housing 1. The cylinder housing 1 is cylindrical and made of cast iron or aluminum alloy. It is used to contain hydraulic oil and provide structural support. A plurality of supporting feet 2 are fixedly connected to the outer side of the cylinder housing 1. The hydraulic cylinder is kept stable by the supporting feet 2. A piston body 3 and a piston rod 4 are arranged inside the cylinder housing 1. The piston body 3 is slidably connected to the inside of the cylinder housing 1. A plurality of ring grooves are opened on the piston body 3. A sliding sealing ring 5 is sleeved on the ring groove. The sliding sealing ring 5 is fitted with the inner wall of the cylinder housing 1. The piston body 3 sleeved with the sliding sealing ring 5 divides the inside of the cylinder housing 1 into a pushing oil chamber 6 and a contraction oil chamber 7.

[0021] The piston body 3 is mechanically connected to the outside through the piston rod 4. One end of the piston rod 4 passes through the contraction oil chamber 7 and extends to the outside of the cylinder housing 1. The other end of the piston rod 4 is connected to the mechanical clamping structure 8 for fast clamping and positioning of the workpiece.

[0022] The mechanical clamping structure 8 includes a fixed support frame 9, a first clamping plate 10, and a second clamping plate 11. The first clamping plate 10 and the second clamping plate are symmetrically arranged. One end of the piston rod 4 extending out of the cylinder housing 1 is fixedly connected to the first clamping plate 10, and the second clamping plate 11 is fixedly connected to the fixed support frame 9 on the side away from the first clamping plate 10. The first clamping plate 10 is kept fixed by the support frame, and the first clamping plate 10 and the second clamping plate 11 are pushed closer by the piston rod 4 to clamp the workpiece. The piston rod 4 pulls the first clamping plate 10 and the second clamping plate 11 away from each other, thereby loosening the workpiece.

[0023] The fixed support frame 9 is H-shaped and has strong structural stability. The bottom of the fixed support frame 9 is fixedly connected to the ground by bolts and can be disassembled.

[0024] Furthermore, one end of the oil cylinder housing 1 close to the push oil chamber 6 is fixedly connected to a first short-stroke compression cylinder 12, and one end of the oil cylinder housing 1 close to the push oil chamber 6 is fixedly connected to a second short-stroke compression cylinder 13.

[0025] The first short-stroke compression cylinder 12 includes a main cylinder body 14, the diameter of which is much larger than the diameter of the oil cylinder housing 1, and the main cylinder body 14 is a barrel-shaped body provided with an oil inlet and an outlet, and a top plate 15 is slidably connected inside the main cylinder body 14, and the top plate 15 is disc-shaped, and its outer edge is in contact with the inner wall of the main cylinder body 14, and a sliding seal is formed, and the main cylinder body 14 is fixedly connected to the oil cylinder housing 1 and pushes the oil chamber 6 to communicate, and a connecting rod 16 is fixedly connected to the side of the top plate 15 away from the oil cylinder housing 1, and the connecting rod 16 penetrates to the outside of the main cylinder body 14, and a sliding seal is formed between the connecting rod 16 and the main cylinder body 14;

[0026] The second short-stroke compression cylinder 13 has the same structure as the first short-stroke compression cylinder 12. The piston rod 4 passes through the main cylinder body 14 and the top plate 15 of the second short-stroke compression cylinder 13, which is convenient for the fixed connection between the piston rod 4 and the first clamping plate 10; and is internally slidably sealed with the main cylinder body 14 to prevent leakage.

[0027] The driving assembly 18 includes a base 19, a C-shaped rod 20 and a reciprocating driving source 21. The two ends of the C-shaped rod 20 are fixedly connected to the connecting rods 16 of the first short-stroke compression cylinder 12 and the second short-stroke compression cylinder 13 respectively. The reciprocating driving source 21 is installed on the base 19, and the reciprocating driving source 21 is kept stable by the base 19.

[0028] The reciprocating driving source 21 includes a return spring 22, an adjustable cam 23 and a servo motor 24. The servo motor 24 drives the adjustable cam 23 to rotate, and the return spring 22 is used to pull the C-shaped rod 20 to reset;

[0029] A first push plate 25 is fixedly connected to one side of the C-shaped rod 20 close to the adjustable cam 23;

[0030] A second push plate 26 is fixedly connected to one side of the C-shaped rod 20 away from the adjustable cam 23; the first push plate 25 and the second push plate 26 are symmetrically arranged on both sides of the C-shaped rod 20;

[0031] A support plate 27 is fixedly connected to the base 19, one end of the return spring 22 is fixedly connected to the support plate 27, and the other end thereof is fixedly connected to the second push plate 26.

[0032] The adjustable cam 23 and the return spring 22 are located on the same side of the first push plate 25. The adjustable cam 23 rotates to push the first push plate 25, so that it drives the C-shaped rod 20 to move toward the second short-stroke compression cylinder 13.

[0033] At the same time, the return spring 22 stores force to pull the second push plate 26, so that it drives the C-shaped rod 20 to move toward the first short-stroke compression cylinder 12, thereby resetting the C-shaped rod 20. The adjustable cam 23 and the return spring 22 cooperate to make the C-shaped rod 20 move back and forth with a fast response speed.

[0034] The adjustable cam 23 includes a protrusion 30 and a disc. The position of the protrusion 30 relative to the disc is adjustable. The protrusion 30 is slidably arranged along the meridian of the disc. An electric telescopic rod 28 is fixedly installed on the disc in the horizontal direction. The shell of the electric telescopic rod 28 is fixedly connected to the disc. The telescopic end of the electric telescopic rod 28 is fixedly connected to the protrusion 30. The end of the protrusion 30 away from the electric telescopic rod 28 is chamfered. The chamfer of the protrusion 30 is conducive to the contact and separation between the adjustable cam 23 and the first push plate 25, and improves the rapid switching of the pushing direction when the adjustable cam 23 rotates.

[0035] A conductive slip ring 29 is installed on the servo motor 24 , and the power supply line of the electric telescopic rod 28 is connected to the power supply through the conductive slip ring 29 .

[0036] The protruding position of the protrusion 30 is adjusted by the electric telescopic rod 28, and the electric telescopic rod 28 pushes the protrusion 30 to move along the meridian direction of the disk. When the protrusion 30 is away from the center of the disk, the pushing distance of the adjustable cam 23 becomes larger, and when the protrusion 30 is close to the center of the disk, the pushing distance of the adjustable cam 23 is reduced. Then, the pushing distance of the adjustable cam 23 to the top plate 15 is adjusted, and the amount of oil entering the pushing oil chamber 6 from the main cylinder body 14 of the first short-stroke compression cylinder 12 is controlled by the pushing distance of the top plate 15, so as to adjust the moving distance of the piston body 3 and the piston inside the oil cylinder housing 1, which is suitable for clamping workpieces of different lengths or diameters, and the adjustment is convenient and fast.

[0037] Furthermore, in order to make the oil compression amount inside the second short-stroke compression cylinder 13 the same as that inside the first short-stroke compression cylinder 12, a guide rod 17 having the same diameter as the piston rod 4 is fixedly connected inside the main cylinder body 14 of the first short-stroke compression cylinder 12 along the axial direction, one end of the guide rod 17 is fixedly connected to the piston body 3, and the other end thereof passes through the first short-stroke compression cylinder 12 and extends to the outside thereof, and the top plate 15 of the first short-stroke compression cylinder 12 is slidably sleeved on the outside of the guide rod 17.

[0038] Through the above structure, when the top plate 15 of the first short-stroke compression cylinder 12 and the top plate 15 of the second short-stroke compression cylinder 13 move synchronously, the change amount of oil inside the main cylinder body 14 is the same, ensuring the telescopic accuracy of the piston rod 4 and the stability of the equipment.

[0039] The inner diameter of the main cylinder body 14 is much larger than the inner diameter of the cylinder shell 1, and the two main cylinder bodies 14 are directly connected to the push oil chamber 6 and the contraction oil chamber 7 of the cylinder shell 1 respectively. When the oil inside the main cylinder body 14 of the first short-stroke compression cylinder 12 enters the push oil chamber 6, the same oil inside the contraction oil chamber 7 enters the main cylinder body 14 of the second short-stroke compression cylinder 13, and the stroke of the internal top plate 15 of the main cylinder body 14 is short, so that the supply speed and return speed of the oil inside the cylinder shell 1 are greatly accelerated, thereby increasing the moving speed of the piston body 3, further promoting the height movement of the piston rod 4, and achieving the purpose of rapid positioning.

[0040] Since the protrusion 30 of the adjustable cam 23 is kept fixed to the disc, the moving distance of the top plate 15 is fixed, so that the extension length or contraction length of the piston rod 4 is fixed, thereby achieving rapid positioning with high precision, no manual operation is required, and the operation is more convenient and the equipment has high working efficiency. By rotating the adjustable cam 23, the switching speed is accelerated, and continuous high-speed pushing can be achieved, which greatly improves the working efficiency of the equipment.

[0041] When the protrusion 30 does not push the C-shaped rod 20, the C-shaped rod 20 is automatically pulled back to its original position by the return spring 22, which has good flexibility and high sensitivity.

[0042] The hydraulic cylinder with a positioning mechanism realizes rapid positioning and distance adjustment of the workpiece through its unique structure and working principle. The specific working principle is: first, the piston body 3 slides inside the cylinder, and the piston body 3 is provided with a plurality of ring grooves and a sliding sealing ring 5 matched with the ring groove, which divides the inside of the cylinder into a pushing oil chamber 6 and a contraction oil chamber 7; the piston body 3 is mechanically connected to the outside through a piston rod 4, one end of the piston rod 4 extends out of the cylinder housing 1, and the other end is connected to a mechanical clamping structure 8, which is used for clamping and releasing the workpiece.

[0043] The mechanical clamping structure 8 includes a fixed support frame 9 and two clamping plates. The two clamping plates can be moved closer or farther away by pushing and pulling the piston rod 4, thereby achieving clamping and loosening operations on the workpiece.

[0044] The driving assembly 18 of the oil cylinder includes a base 19, a C-shaped rod 20 and a reciprocating driving source 21. The reciprocating driving source 21 is composed of a return spring 22, an adjustable cam 23 and a servo motor 24. The servo motor 24 drives the cam to rotate, and the return spring 22 is used to ensure the return of the C-shaped rod 20; the two ends of the C-shaped rod 20 are respectively connected to the connecting rod 16 of the first short-stroke compression cylinder 12 and the second short-stroke compression cylinder 13, so as to control the movement of the piston rod 4.

[0045] The design of the adjustable cam 23 allows the protruding position of the bump 30 to be adjusted by the electric telescopic rod 28, thereby changing the pushing distance of the cam. This adjustment mechanism allows the moving distance of the piston rod 4 to be adjusted as needed, achieving rapid positioning and distance adjustment.

[0046] In order to ensure that the compression amount of the oil in the first short-stroke compression cylinder 12 and the second short-stroke compression cylinder 13 is the same, a guide rod 17 is fixed inside the main cylinder body 14 along the axial direction, so that when the top plates 15 of the two cylinder bodies move synchronously, the change amount of the oil is the same, thereby ensuring the telescopic accuracy of the piston rod 4 and the stability of the equipment.

[0047] During operation, the servo motor 24 drives the adjustable cam 23 to rotate. The rotation of the adjustable cam 23 causes the top of the protrusion 30 to push the first push plate 25, driving the C-shaped rod 20 to move toward the second short-stroke compression cylinder 13. The C-shaped rod 20 is fixedly connected to the top plates 15 inside the first short-stroke compression cylinder 12 and the second short-stroke compression cylinder 13 respectively through the connecting rod 16. The top plate 15 of the first short-stroke compression cylinder 12 pushes the hydraulic oil inside its main cylinder body 14 to flow into the pushing oil chamber 6. Since the inner diameter of the main cylinder body 14 is larger than the inner diameter of the pushing oil chamber 6, the same volume of hydraulic oil can be injected faster and with a shorter stroke than traditional hydraulic pipelines, thereby accelerating the push on the piston body 3, so that the piston body 3 pushes the piston rod 4 outward at high speed, thereby accelerating the push on the piston body 3. The clamping positioning speed of the fast device is improved, and the work efficiency is improved. The pushing oil chamber 6 and the contraction oil chamber 7 are directly connected to the main cylinder body 14. The flow diameter is large, and the delivery is faster than that of the traditional hydraulic pipe. When the piston rod 4 extends and moves, the oil in the contraction oil chamber 7 returns to the main cylinder body 14 of the second short-stroke compression cylinder 13 at a fast speed, reducing the back pressure of the oil in the contraction oil chamber 7 on the moving piston body 3, and the small resistance is conducive to the high-speed movement of the piston. When the bump 30 of the adjustable cam 23 continues to rotate and does not contact the first push plate 25, the first push plate 25 loses support, and the tension stored in the return spring 22 pulls the second push plate 26 to move in the opposite direction quickly, that is, the C-shaped rod 20 moves toward the first short-stroke compression cylinder 12, the piston rod 4 contracts, and the workpiece is released. With the above steps, the high-speed reciprocating motion of the piston rod 4 is realized. By adjusting the protruding position of the bump 30, the positioning and distance can be quickly adjusted without manual operation, thereby improving the working efficiency and positioning accuracy of the equipment.

[0048] Although specific 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 specific embodiments without departing from the principles and spirit thereof, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A hydraulic cylinder with a positioning mechanism, comprising a cylinder housing (1), a piston body (3) and a piston rod (4) arranged inside the cylinder housing (1), the piston body (3) being slidably connected to the inside of the cylinder housing (1), a plurality of ring grooves being provided on the piston body (3), a sliding sealing ring (5) being sleeved on the ring groove, the sliding sealing ring (5) being in contact with the inner wall of the cylinder housing (1), characterized in that: A piston body (3) sleeved with a sliding sealing ring (5) divides the interior of a cylinder housing (1) into a pushing oil chamber (6) and a contraction oil chamber (7); the piston body (3) is fixedly connected to one end of a piston rod (4); the other end of the piston rod (4) passes through the contraction oil chamber (7) and extends out of the cylinder housing (1); one end of the piston rod (4) located outside the cylinder housing (1) is connected to a mechanical clamping structure (8); the piston rod (4) and the mechanical clamping structure (8) cooperate to quickly clamp and position a workpiece; a high-speed pushing mechanism for pushing a hydraulic cylinder for rapid positioning is arranged outside the cylinder housing (1).

2. A hydraulic cylinder with a positioning mechanism according to claim 1, characterized in that: The oil cylinder housing (1) is cylindrical and is used to contain hydraulic oil and provide structural support. A plurality of supporting legs (2) are fixedly connected to the outer side of the oil cylinder housing (1).

3. The hydraulic cylinder with a positioning mechanism according to claim 1, characterized in that: The mechanical clamping structure (8) comprises a fixed support frame (9), a first clamping plate (10), and a second clamping plate (11). The first clamping plate (10) and the second clamping plate (11) are symmetrically arranged. One end of the piston rod (4) extending out of the cylinder housing (1) is fixedly connected to the first clamping plate (10), and the side of the second clamping plate (11) away from the first clamping plate (10) is fixedly connected to the fixed support frame (9).

4. The hydraulic cylinder with a positioning mechanism according to claim 3, characterized in that: The high-speed pushing mechanism comprises a first short-stroke compression cylinder (12) and a second short-stroke compression cylinder (13); the first short-stroke compression cylinder (12) is fixed to one end of the oil cylinder housing (1) and is fixedly connected to a port of a pushing oil chamber (6); and one end of the oil cylinder housing (1) close to the pushing oil chamber (6) is fixedly connected to the second short-stroke compression cylinder (13).

5. The hydraulic cylinder with a positioning mechanism according to claim 4, characterized in that: The first short-stroke compression cylinder (12) comprises a main cylinder body (14), the diameter of the main cylinder body (14) is larger than the diameter of the cylinder housing (1), the main cylinder body (14) is barrel-shaped, a top plate (15) is slidably connected inside the main cylinder body (14), the top plate (15) is disc-shaped, the outer edge of which is in contact with the inner wall of the main cylinder body (14) and is slidably sealed, the main cylinder body (14) is fixedly connected to the cylinder housing (1) and pushes the oil chamber (6) to communicate internally, a connecting rod (16) is fixedly connected to the side of the top plate (15) away from the cylinder housing (1), the connecting rod (16) passes through the outside of the main cylinder body (14), and a slidably sealed connection is formed between the connecting rod (16) and the main cylinder body (14).

6. The hydraulic cylinder with a positioning mechanism according to claim 5, characterized in that: The second short-stroke compression cylinder (13) has the same structure as the first short-stroke compression cylinder (12), and the piston rod (4) passes through the main cylinder body (14) and the top plate (15) of the second short-stroke compression cylinder (13) and is fixedly connected to the first clamping plate (10).

7. The hydraulic cylinder with a positioning mechanism according to claim 6, characterized in that: The driving assembly (18) comprises a base (19), a C-shaped rod (20) and a reciprocating driving source (21). The two ends of the C-shaped rod (20) are respectively fixedly connected to the connecting rods (16) of the first short-stroke compression cylinder (12) and the second short-stroke compression cylinder (13). The reciprocating driving source (21) is installed on the base (19). The reciprocating driving source (21) comprises a reset spring (22), an adjustable cam (23) and a servo motor (24). The servo motor (24) drives the adjustable cam (23) to rotate. The reset spring (22) is used to pull the C-shaped rod (20) to reset.

8. The hydraulic cylinder with a positioning mechanism according to claim 6, characterized in that: The first push plate (25) is fixedly connected to the side of the C-shaped rod (20) close to the adjustable cam (23); the second push plate (26) is fixedly connected to the side of the C-shaped rod (20) away from the adjustable cam (23); the first push plate (25) and the second push plate (26) are symmetrically arranged on both sides of the C-shaped rod (20); a support plate (27) is fixedly connected to the base (19); one end of the return spring (22) is fixedly connected to the support plate (27), and the other end is fixedly connected to the second push plate (26); the adjustable cam (23) and the return spring (22) are located on the same side of the first push plate (25); the adjustable cam (23) rotates to push the first push plate (25), so that it drives the C-shaped rod (20) to move in the direction of the second short-stroke compression cylinder (13).

9. The hydraulic cylinder with a positioning mechanism according to claim 6, characterized in that: The adjustable cam (23) comprises a protrusion (30) and a disc, the protrusion (30) being slidably arranged along the longitude of the disc, an electric telescopic rod (28) being fixedly mounted on the disc in the horizontal direction, the outer shell of the electric telescopic rod (28) being fixedly connected to the disc, the telescopic end of the electric telescopic rod (28) being fixedly connected to the protrusion (30), and a chamfer being arranged at one end of the protrusion (30) away from the electric telescopic rod (28).

10. The hydraulic cylinder with a positioning mechanism according to claim 6, characterized in that: A guide rod (17) having the same diameter as the piston rod (4) is fixedly connected to the main cylinder body (14) of the first short-stroke compression cylinder (12) along the axial direction; one end of the guide rod (17) is fixedly connected to the piston body (3); the other end of the guide rod (17) passes through the first short-stroke compression cylinder (12) and extends to the outside thereof; the top plate (15) of the first short-stroke compression cylinder (12) is slidably sleeved on the outside of the guide rod (17).

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