Hydraulic system with pressure relief protection structure for large-load elevator

Abstract

The invention relates to the technical field of hydraulic devices, in particular to a hydraulic system with a pressure relief protection structure for a large-load hoister, which comprises a bearing table, racks are symmetrically arranged outside the bearing table, hydraulic rods are fixedly connected to the inner walls of the racks, chains are fixedly connected to the outer walls of the racks, and the chains are fixedly connected to the outer walls of the racks. A connecting seat is slidably connected to the outer wall of the rack, positioning holes are symmetrically formed in the wall of the rack, and a hydraulic device is fixedly connected to the outer wall of a hydraulic rod. Through arrangement of the adjusting device, through a series of mechanical linkage driven by movement of a sliding barrel, finally, an inserting rod is inserted into the positioning holes of the rack, and movement of the connecting seat is limited; when the hydraulic system is overpressure, additional safety guarantee is provided for the bearing table, the bearing table is prevented from falling off due to damage of the hydraulic rod, the safety of the large-load elevator in the operation process is greatly improved, and potential safety risks are reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of hydraulic devices, and particularly relates to a hydraulic system for a large-load hoist with a pressure relief protection structure. Background Art

[0002] In industrial production and various large-scale engineering operations, large-load hoists are widely used in many scenarios such as material handling and equipment installation. The stability and safety of their operation are crucial, and the hydraulic system, as the core power source of the large-load hoist, plays a decisive role in the overall performance.

[0003] For traditional hydraulic systems for large-load hoists, when the system pressure suddenly rises beyond the rated value due to unexpected situations, there is a lack of effective pressure relief and buffering measures. The hydraulic oil often flows back in large quantities in a short period of time. This not only causes strong impacts on components such as system pipelines and valves, resulting in premature damage to these components. On the other hand, when the system pressure is too high and causes damage to key components such as hydraulic rods, the existing hydraulic system cannot effectively protect the bearing platform in time. The bearing platform is very likely to fall due to the loss of support, causing serious equipment damage and personnel casualties.

[0004] Based on the above technical defects of traditional hydraulic systems for large-load hoists, the present invention is committed to developing a hydraulic system for a large-load hoist with a pressure relief protection structure to solve the key problems of hydraulic oil backflow impact and bearing platform safety protection, and provide reliable guarantee for the stable, efficient, and safe operation of large-load hoists. Summary of the Invention

[0005] In view of the deficiencies of the prior art, the technical solution adopted by the present invention to solve its technical problems is: a hydraulic system for a large-load hoist with a pressure relief protection structure, including: a bearing platform, on the outside of which frames are symmetrically arranged; on the inner wall of the frames, hydraulic rods are fixedly connected; on the outer wall of the frames, chains are fixedly connected; on the outer wall of the frames, a connecting seat is slidably connected; positioning holes are symmetrically opened in the walls of the frames; on the outer wall of the hydraulic rods, a hydraulic device is fixedly connected, and the hydraulic device is used for relieving pressure when the hydraulic rods are over-pressurized, and an adjusting device is arranged outside the hydraulic device; the hydraulic device includes an oil inlet pipe, on the outer wall of which a pressure relief valve is fixedly connected, the output end of the pressure relief valve is fixedly connected to a return pipe, an oil return pipe is arranged at the top of the oil inlet pipe, a pressure inlet pipe is arranged on the outer wall of the oil inlet pipe, on the outer wall of the pressure inlet pipe, a rubber hose is fixedly connected, and the top end of the rubber hose is fixedly connected to a sliding pipe; the adjusting device includes a pressure relief cylinder, inside which a sliding cylinder is slidably connected, on the outer wall of the pressure relief cylinder, a fixing frame is fixedly connected, inside the fixing frame, a rotating rod is rotatably connected, on the outer wall of the rotating rod, a driving gear is fixedly connected, and a pushing component is fixedly connected to the outer wall of the fixing frame.

[0006] The present invention is further configured such that the outer wall of the connecting seat is slidably connected to the outer wall of the bearing platform. One end of the chain away from the frame is fixedly connected to the outer wall of the connecting seat, and the outer wall of the chain is slidably connected to the top end of the output end of the hydraulic rod. The hydraulic rod expands and contracts to push the chain upward, causing the chain to pull the connecting seat to move. By the movement of the connecting seat on the frame, the bearing platform is driven to lift and lower.

[0007] The present invention is further configured such that the outer wall of the inlet oil pipe is fixedly connected to the inner wall of the bottom end of the hydraulic rod, the outer wall of the return oil pipe is fixedly connected to the inner wall of the top end of the hydraulic rod, and the outer wall of the sliding pipe is fixedly connected to the outer wall of the connecting seat. The hydraulic device is responsible for controlling the expansion and contraction of the hydraulic rod. The hydraulic oil from the external hydraulic station enters the hydraulic rod through the inlet oil pipe, and the hydraulic oil inside the hydraulic rod is output to the hydraulic station through the return oil pipe, thereby controlling the expansion and contraction of the hydraulic rod.

[0008] The present invention is further configured such that the inner wall of the sliding pipe is symmetrically and slidably connected with insertion rods. The inner wall of the sliding pipe is slidably connected with a pushing plug. The outer wall of the pushing plug is fixedly connected with a pushing spring. One end of the pushing spring away from the pushing plug is fixedly connected to the inner wall of the sliding pipe. The outer wall of the insertion rod is slidably connected to the inner wall of the positioning hole. Through the pushing of the hydraulic oil in the rubber hose, the pushing plug moves and squeezes the internal hydraulic oil, thereby pushing the insertion rods at both ends to move and insert into the positioning holes on the frame, thereby restricting the movement of the connecting seat and preventing the bearing platform from falling due to the damage of the hydraulic rod under overpressure.

[0009] The present invention is further configured such that a flow pipe is fixedly connected to the inner wall of the pressure relief cylinder. An oil discharge port is formed in the wall of the flow pipe. A rack is fixedly connected to the outer wall of the sliding cylinder. When overpressure occurs, the pressure relief valve will automatically open, and the excess hydraulic oil will be discharged back to the external hydraulic station through the return pipe. When the hydraulic oil flows back, it will first enter the pressure relief cylinder. At this time, the hydraulic oil cannot pass through, thereby pushing the sliding cylinder to move. The internally provided spring plays a role in buffering and resetting, enabling the flow pipe to enter the sliding cylinder. At this time, the hydraulic oil can pass through the oil discharge port on the flow pipe and then flow back.

[0010] The present invention is further configured such that the rack is engaged with a driving gear. The inner wall of the pressure relief cylinder is fixedly connected to the outer wall of the return pipe. The pressure relief cylinder is fixedly connected to the external hydraulic station. During the movement of the sliding cylinder, the rack is driven to move. By the movement of the rack, the driving gear is toggled to drive the rotating rod to rotate on the fixed frame.

[0011] The present invention is further configured such that the pushing assembly includes a fixed cylinder, the inner wall of the fixed cylinder is slidably connected to a pushing block, the outer wall of the pushing block is fixedly connected to a gear rod, a gear ring is provided outside the gear rod, and the inner wall of the gear ring is rotatably connected to a connecting block. The rotating rod drives the connecting block to rotate, and the spring inside the connecting block pushes the clamping block to clamp into the inner wall of the gear ring, so that when the connecting block rotates, the gear ring can be driven to rotate.

[0012] The present invention is further configured such that the outer wall of the fixed cylinder is fixedly connected to the outer wall of the fixed frame, the inner wall of the fixed cylinder is fixedly connected to the outer wall of the inlet pressure pipe, the gear ring is meshed with the gear rod, and the outer wall of the gear rod is slidably connected to the inner wall of the fixed cylinder. The gear ring moves the meshed gear rod and causes the push block to move in the fixed cylinder, thereby squeezing the hydraulic oil inside and transferring it to the sliding tube through the inlet pressure pipe and the rubber hose.

[0013] The present invention is further configured such that the inner wall of the connecting block is fixedly connected to the outer wall of the rotating rod, the inner wall of the connecting block is rotatably connected to the adjusting rod, the outer wall of the adjusting rod is fixedly connected to a clamping block, the outer wall of the clamping block is slidably connected to the inner wall of the connecting block, and the clamping block is slidably connected to the inner wall of the gear ring.

[0014] The beneficial effects of the present invention are as follows: 1. The present invention sets a hydraulic device. During the hydraulic oil reflux process, the hydraulic oil first enters the pressure relief cylinder. Since it cannot pass directly at the beginning, it pushes the slide cylinder to move, thereby triggering a series of mechanical transmissions, thereby achieving effective buffering and control of the hydraulic oil reflux. This design not only ensures the stability of the pressure relief process, but also prevents the system from being impacted by the instantaneous large-scale reflux of hydraulic oil, thereby extending the service life of various components in the system.

[0015] 2. The present invention provides an adjustment device, which drives a series of mechanical linkages through the movement of the slide cylinder, and finally allows the insertion rod to be inserted into the positioning hole of the frame to limit the movement of the connecting seat. This arrangement provides additional safety protection for the load-bearing platform when the hydraulic system is over-pressurized, preventing the load-bearing platform from falling due to damage to the hydraulic rod, greatly improving the safety of the large-load hoist during operation and reducing potential safety risks.

[0016] 3. The present invention sets a push assembly. When the pressure in the hydraulic rod returns to normal, the system can automatically reset by rotating the adjustment rod, the plug rod is disengaged from the positioning hole, and the connecting seat can continue to drive the bearing platform to move. This automatic reset mechanism enables the system to quickly return to normal working state without complicated manual intervention after completing a pressure relief protection, ensuring the continuity and efficiency of the hoist operation and improving production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1is a schematic structural diagram of the present invention; Figure 2 is a schematic structural diagram of the frame of the present invention; Figure 3 is a schematic structural diagram of the hydraulic device of the present invention; Figure 4 is a schematic structural diagram of the sliding tube of the present invention; Figure 5 is a schematic structural diagram of the pushing assembly of the present invention; Figure 6 is a schematic structural diagram of the pressure relief cylinder of the present invention; Figure 7 is a schematic structural diagram of the pushing assembly of the present invention; Figure 8 is the present invention Figure 7 enlarged view of the structure at A.

[0018] In the figure: 1, bearing platform; 2, hydraulic device; 21, return oil pipe; 22, inlet oil pipe; 23, pressure relief valve; 24, return pipe; 25, rubber hose; 26, sliding tube; 27, insertion rod; 28, pushing plug; 29, pushing spring; 210, inlet pressure pipe; 3, hydraulic rod; 4, connecting seat; 5, chain; 6, adjusting device; 61, pressure relief cylinder; 62, fixing frame; 63, pushing assembly; 631, fixing cylinder; 632, pushing block; 633, rack; 634, gear ring; 635, connecting block; 636, adjusting rod; 637, clamping block; 64, sliding cylinder; 65, rotating rod; 66, driving gear; 67, rack; 68, circulation pipe; 69, oil drain port; 7, positioning hole; 8, frame. Detailed implementation manners

[0019] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific implementation manners. The embodiments of the present invention are given for the purpose of illustration and description, and are not exhaustive or limit the present invention to the disclosed form. Many modifications and variations are obvious to those of ordinary skill in the art. The embodiments are selected and described to better illustrate the principles and practical applications of the present invention, and enable those of ordinary skill in the art to understand the present invention and thus design various embodiments with various modifications suitable for specific purposes. Embodiment

[0020] Please refer to Figure 1 - Figure 8, the present invention provides a technical solution: a hydraulic system for a large-load hoist with a pressure relief protection structure, comprising: a bearing platform 1, with frames 8 symmetrically arranged outside the bearing platform 1, a hydraulic rod 3 fixedly connected to the inner wall of the frame 8, a chain 5 fixedly connected to the outer wall of the frame 8, a connecting seat 4 slidably connected to the outer wall of the frame 8, positioning holes 7 symmetrically formed in the wall of the frame 8, a hydraulic device 2 fixedly connected to the outer wall of the hydraulic rod 3, the hydraulic device 2 being used for relieving pressure when the hydraulic rod 3 is over-pressured, and an adjusting device 6 arranged outside the hydraulic device 2; the hydraulic device 2 includes an oil inlet pipe 22, a pressure relief valve 23 fixedly connected to the outer wall of the oil inlet pipe 22, a return pipe 24 fixedly connected to the output end of the pressure relief valve 23, an oil return pipe 21 arranged at the top of the oil inlet pipe 22, a pressure inlet pipe 210 arranged on the outer wall of the oil inlet pipe 22, a rubber hose 25 fixedly connected to the outer wall of the pressure inlet pipe 210, and a sliding pipe 26 fixedly connected to the top end of the rubber hose 25; the adjusting device 6 includes a pressure relief cylinder 61, a sliding cylinder 64 slidably connected to the inner wall of the pressure relief cylinder 61, a fixed frame 62 fixedly connected to the outer wall of the pressure relief cylinder 61, a rotating rod 65 rotatably connected to the inner wall of the fixed frame 62, a driving gear 66 fixedly connected to the outer wall of the rotating rod 65, and a pushing component 63 fixedly connected to the outer wall of the fixed frame 62.

[0021] The outer wall of the connecting seat 4 is slidably connected to the outer wall of the bearing platform 1, one end of the chain 5 away from the frame 8 is fixedly connected to the outer wall of the connecting seat 4, and the outer wall of the chain 5 is slidably connected to the top end of the output end of the hydraulic rod 3. When the hydraulic rod 3 extends, it pushes the slidably connected chain 5 upward, causing the chain 5 to pull the fixedly connected connecting seat 4 to move, and driving the fixedly installed bearing platform 1 to lift and lower through the movement of the connecting seat 4 on the outer wall of the frame 8.

[0022] The outer wall of the oil inlet pipe 22 is fixedly connected to the inner wall of the bottom end of the hydraulic rod 3, the outer wall of the oil return pipe 21 is fixedly connected to the inner wall of the top end of the hydraulic rod 3, and the outer wall of the sliding pipe 26 is fixedly connected to the outer wall of the connecting seat 4. The hydraulic device 2 is responsible for controlling the telescopic movement of the hydraulic rod 3. The hydraulic oil from an external hydraulic station enters the fixedly connected hydraulic rod 3 through the oil inlet pipe 22, and the hydraulic oil inside the hydraulic rod 3 is output to the hydraulic station through the fixedly connected oil return pipe 21, thereby controlling the telescopic movement of the hydraulic rod 3.

[0023] The inner wall of the sliding tube 26 is symmetrically and slidably connected with the insertion rods 27. The inner wall of the sliding tube 26 is slidably connected with the pushing plug 28. The outer wall of the pushing plug 28 is fixedly connected with the pushing spring 29. One end of the pushing spring 29 away from the pushing plug 28 is fixedly connected with the inner wall of the sliding tube 26. The outer wall of the insertion rod 27 is slidably connected with the inner wall of the positioning hole 7. Driven by the hydraulic oil in the rubber hose 25, the pushing plug 28 moves, squeezing the internal hydraulic oil, thereby pushing the insertion rods 27 at both ends to move and insert into the positioning holes 7 on the frame 8, thus restricting the movement of the connecting seat 4. When the pressure in the hydraulic rod 3 is normal, under the action of the pushing spring 29, the pushing plug 28 moves back to its original position, causing the insertion rods 27 to disengage from the positioning holes 7, and the connecting seat 4 can continue to drive the carrying platform 1 to move.

[0024] The inner wall of the pressure relief cylinder 61 is fixedly connected with the flow pipe 68. An oil discharge port 69 is formed in the wall of the flow pipe 68. The outer wall of the sliding cylinder 64 is fixedly connected with the rack 67. When the hydraulic oil flows back, it will first enter the pressure relief cylinder 61. At this time, the hydraulic oil cannot pass through, thereby pushing the sliding cylinder 64 to move, causing the flow pipe 68 to enter the sliding cylinder 64. At this time, the hydraulic oil can pass through the oil discharge port 69 on the flow pipe 68 and then pass through the pressure relief cylinder 61 and be discharged back to the external hydraulic station through the return pipe 24 at the other end.

[0025] The rack 67 meshes with the driving gear 66. The inner wall of the pressure relief cylinder 61 is fixedly connected with the outer wall of the return pipe 24. The pressure relief cylinder 61 is fixedly connected with the external hydraulic station. During the movement of the sliding cylinder 64, it will drive the fixedly connected rack 67 to move. By the movement of the rack 67, the driving gear 66 is toggled to drive the rotating rod 65 to rotate on the inner wall of the fixed frame 62.

[0026] The pushing component 63 includes a fixed cylinder 631. The inner wall of the fixed cylinder 631 is slidably connected with a pushing block 632. The outer wall of the pushing block 632 is fixedly connected with a toothed rod 633. A toothed ring 634 is arranged outside the toothed rod 633. The inner wall of the toothed ring 634 is rotatably connected with a connecting block 635. Through the spring inside the connecting block 635, the pushing block 637 is pushed into the inner wall of the toothed ring 634. Thus, when the connecting block 635 rotates, it can drive the toothed ring 634 to rotate, thereby toggling the meshing toothed rod 633 to move.

[0027] The outer wall of the fixed cylinder 631 is fixedly connected with the outer wall of the fixed frame 62. The inner wall of the fixed cylinder 631 is fixedly connected with the outer wall of the pressure inlet pipe 210. The toothed ring 634 meshes with the toothed rod 633. The outer wall of the toothed rod 633 is slidably connected with the inner wall of the fixed cylinder 631. The toothed rod 633 moves, causing the fixedly connected pushing block 632 to move inside the fixed cylinder 631, thereby squeezing the internal hydraulic oil, which is transmitted to the inside of the sliding tube 26 through the pressure inlet pipe 210 and the rubber hose 25.

[0028] The inner wall of the connecting block 635 is fixedly connected to the outer wall of the rotating rod 65. The inner wall of the connecting block 635 is rotatably connected to an adjusting rod 636. The outer wall of the adjusting rod 636 is fixedly connected to a clamping block 637. The outer wall of the clamping block 637 is slidably connected to the inner wall of the connecting block 635. The clamping block 637 is slidably connected to the inner wall of the toothed ring 634.

[0029] Working principle: When in use, the hydraulic device 2 is responsible for controlling the telescopic movement of the hydraulic rod 3. The hydraulic oil from the external hydraulic station enters the hydraulic rod 3 through the oil inlet pipe 22, and the hydraulic oil inside the hydraulic rod 3 is output to the hydraulic station through the oil return pipe 21, thereby controlling the telescopic movement of the hydraulic rod 3. When the hydraulic rod 3 extends, it pushes the chain 5 upward, causing the chain 5 to pull the connecting seat 4 to move. Through the movement of the connecting seat 4 on the frame 8, the carrying platform 1 is driven to lift and lower. During the lifting and lowering process of the hydraulic rod 3, when the pressure in the hydraulic system exceeds the set value, the pressure relief valve 23 will automatically open, and the excess hydraulic oil will be discharged back to the external hydraulic station through the return pipe 24. When the hydraulic oil flows back, it will first enter the pressure relief cylinder 61. At this time, the hydraulic oil cannot pass through, thereby pushing the sliding cylinder 64 to move, causing the flow pipe 68 to enter the sliding cylinder 64. At this time, the hydraulic oil can pass through the oil discharge port 69 on the flow pipe 68, thereby passing through the pressure relief cylinder 61 and being discharged back to the external hydraulic station through the other end of the return pipe 24. During the movement of the sliding cylinder 64, it will drive the rack 67 to move. Through the movement of the rack 67, the driving gear 66 is toggled to drive the rotating rod 65 to rotate on the fixed bracket 62. Through the provided pushing assembly 63, the rotating rod 65 drives the connecting block 635 to rotate. Through the spring inside the connecting block 635, the clamping block 637 is pushed to engage with the inner wall of the toothed ring 634. Thus, when the connecting block 635 rotates, it can drive the toothed ring 634 to rotate, thereby toggling the engaged toothed rod 633 to move, and causing the pushing block 632 to move inside the fixed cylinder 631, thereby squeezing the internal hydraulic oil, which is transmitted to the sliding pipe 26 through the pressure inlet pipe 210 and the rubber hose 25. Under the push of the hydraulic oil in the rubber hose 25, the pushing plug 28 moves, and the internal hydraulic oil is squeezed, thereby pushing the two end inserting rods 27 to move and insert into the positioning holes 7 on the frame 8, thereby restricting the movement of the connecting seat 4 to prevent the carrying platform 1 from falling due to damage to the hydraulic rod 3 during overpressure. When the pressure in the hydraulic rod 3 is normal, by rotating the adjusting rod 636, the clamping block 637 no longer engages with the inner wall of the toothed ring 634. At this time, under the action of the pushing spring 29, the pushing plug 28 moves back to its original position. By squeezing the hydraulic oil in the sliding pipe 26 and the fixed cylinder 631, both the inserting rod 27 and the pushing block 632 move back to their original positions to prepare for the next pressure relief protection, causing the inserting rod 27 to disengage from the positioning hole 7, and the connecting seat 4 can continue to drive the carrying platform 1 to move.

[0030] Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all embodiments. All other embodiments obtained by those of ordinary skill in the art and related fields based on the embodiments of the present invention without creative efforts shall fall within the scope of protection of the present invention. Structures, devices, and operation methods not specifically described and explained in the present invention shall be implemented by conventional means in the art unless otherwise specified and limited.

Claims

1. A hydraulic system for a large-load hoist with a pressure relief protection structure, comprising: Carrier table (1), with frames (8) symmetrically arranged outside the carrier table (1). A hydraulic rod (3) is fixedly connected to the inner wall of the frame (8). A chain (5) is fixedly connected to the outer wall of the frame (8). A connecting seat (4) is slidably connected to the outer wall of the frame (8). It is characterized in that positioning holes (7) are symmetrically formed in the wall of the frame (8). A hydraulic device (2) is fixedly connected to the outer wall of the hydraulic rod (3). The hydraulic device (2) is used for relieving pressure when the hydraulic rod (3) is over-pressured. An adjusting device (6) is arranged outside the hydraulic device (2); The hydraulic device (2) includes an oil inlet pipe (22). A pressure relief valve (23) is fixedly connected to the outer wall of the oil inlet pipe (22). The output end of the pressure relief valve (23) is fixedly connected to a return pipe (24). An oil return pipe (21) is arranged at the top of the oil inlet pipe (22). An oil inlet pressure pipe (210) is arranged on the outer wall of the oil inlet pipe (22). A rubber hose (25) is fixedly connected to the outer wall of the oil inlet pressure pipe (210). The top end of the rubber hose (25) is fixedly connected to a sliding pipe (26); The adjusting device (6) includes a pressure relief cylinder (61). A sliding cylinder (64) is slidably connected to the inner wall of the pressure relief cylinder (61). A fixed frame (62) is fixedly connected to the outer wall of the pressure relief cylinder (61). A rotating rod (65) is rotatably connected to the inner wall of the fixed frame (62). A driving gear (66) is fixedly connected to the outer wall of the rotating rod (65). A pushing assembly (63) is fixedly connected to the outer wall of the fixed frame (62).

2. The hydraulic system for a large-load hoist with a pressure relief protection structure according to claim 1, characterized in that: The outer wall of the connecting seat (4) is slidably connected to the outer wall of the carrier table (1). One end of the chain (5) away from the frame (8) is fixedly connected to the outer wall of the connecting seat (4). The outer wall of the chain (5) is slidably connected to the top end of the output end of the hydraulic rod (3).

3. The hydraulic system for a large-load hoist with a pressure relief protection structure according to claim 1, characterized in that: The outer wall of the oil inlet pipe (22) is fixedly connected to the inner wall of the bottom end of the hydraulic rod (3). The outer wall of the oil return pipe (21) is fixedly connected to the inner wall of the top end of the hydraulic rod (3). The outer wall of the sliding pipe (26) is fixedly connected to the outer wall of the connecting seat (4).

4. A hydraulic system for a large-load hoist with a pressure relief protection structure according to claim 3, characterized in that: Insertion rods (27) are symmetrically and slidably connected to the inner wall of the sliding pipe (26). A pushing plug (28) is interactively connected to the inner wall of the sliding pipe (26). A pushing spring (29) is fixedly connected to the outer wall of the pushing plug (28). One end of the pushing spring (29) away from the pushing plug (28) is fixedly connected to the inner wall of the sliding pipe (26). The outer wall of the insertion rod (27) is slidably connected to the inner wall of the positioning hole (7).

5. A hydraulic system for a large-load hoist with a pressure relief protection structure according to claim 1, characterized in that: A flow pipe (68) is fixedly connected to the inner wall of the pressure relief cylinder (61). An oil discharge port (69) is formed in the wall of the flow pipe (68). A rack (67) is fixedly connected to the outer wall of the sliding cylinder (64).

6. The hydraulic system for a large-load hoist with a pressure relief protection structure according to claim 5, characterized in that: The rack (67) meshes with the driving gear (66). The inner wall of the pressure relief cylinder (61) is fixedly connected to the outer wall of the return pipe (24). The pressure relief cylinder (61) is fixedly connected to an external hydraulic station.

7. A hydraulic system for a large-load hoist with a pressure relief protection structure according to claim 1, characterized in that: The pushing component (63) includes a fixed cylinder (631), a pushing block (632) is slidably connected to the inner wall of the fixed cylinder (631), a toothed rod (633) is fixedly connected to the outer wall of the pushing block (632), a toothed ring (634) is arranged outside the toothed rod (633), and a connecting block (635) is rotatably connected to the inner wall of the toothed ring (634).

8. A hydraulic system for a large-load hoist with a pressure relief protection structure according to claim 7, characterized in that: The outer wall of the fixed cylinder (631) is fixedly connected to the outer wall of the fixed frame (62), the inner wall of the fixed cylinder (631) is fixedly connected to the outer wall of the inlet pressure pipe (210), the toothed ring (634) is engaged with the toothed rod (633), and the outer wall of the toothed rod (633) is slidably connected to the inner wall of the fixed cylinder (631).

9. The hydraulic system for a large-load hoist with a pressure relief protection structure according to claim 7, characterized in that: The inner wall of the connecting block (635) is fixedly connected to the outer wall of the rotating rod (65), an adjusting rod (636) is rotatably connected to the inner wall of the connecting block (635), a clamping block (637) is fixedly connected to the outer wall of the adjusting rod (636), the outer wall of the clamping block (637) is slidably connected to the inner wall of the connecting block (635), and the clamping block (637) is slidably connected to the inner wall of the toothed ring (634).

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