A double telescopic system

Abstract

The present invention provides a double telescopic system, including a hydraulic control system and a double telescopic crane, the hydraulic control system including a multi-way valve group, an oil tank, an oil pump, a hook limit valve group, an overload protection valve group and a winch control module, the oil tank is connected to one end of the oil pump, the other end of the oil pump is connected to the oil inlet end of the multi-way valve group, and the oil outlet end of the multi-way valve group is connected to the oil tank; the hook limit valve group is connected to the control end of the multi-way valve group, and an overload protection valve group is provided on the hook limit valve group, and the hydraulic control system is used to control the double telescopic crane; through the above structure, it is ensured that the double telescopic crane will not cause structural damage to the telescopic arm due to excessive extension during operation, and it can also be ensured that the lifting of the double telescopic crane will not exceed the upper limit of the lifting.

Description

Technical Field

[0001] The present invention relates to the technical field of telescopic crane systems, and in particular to a double telescopic system. Background Art

[0002] Ship cranes are essential components of transport vessels, used for lifting and loading cargo. Due to the limited space onboard and the compact layout of various equipment and hull structures, the operational stability of ship cranes directly impacts the safety of cargo transport. For safety reasons, ships must implement mandatory automatic limit switches when cranes are restricted by their installation location or nearby fixed or non-fixed obstacles. These limits are categorized as either full limit switches or zone limit switches. Full limit switches prohibit the crane from entering a specific rotation zone under any operating conditions. Zone limit switches restrict the crane from rotating into a specific zone only when the boom elevation angle exceeds a certain threshold, and once within the zone, the boom elevation angle cannot fall below the threshold. Existing limit switches are pre-welded in obstructed zones based on the ship layout. Hydraulic or electrical limit switches are used to sense the zone boundaries and implement limit stops.

[0003] Chinese patent application number 201810944519.3, published on October 23, 2018, discloses a dual-telescopic self-balancing tower crane for cargo ships. Normally, the telescopic base assembly and telescopic self-balancing boom assembly of the dual-telescopic self-balancing tower crane are retracted and docked. During operation, the telescopic base assembly and the telescopic self-balancing boom assembly, which can be raised and rotated without being restricted by any area, and the hoisting mechanism therein enable direct loading and unloading of cargo over small and large spans between the ship and the dock, eliminating reliance on dock cranes. The dual-telescopic self-balancing tower crane for cargo ships is characterized by: a dual-telescopic self-balancing tower crane installed on a cargo ship; normally, the telescopic base assembly and the telescopic self-balancing boom assembly of the dual-telescopic self-balancing tower crane are retracted and docked; the telescopic base assembly is mounted on the cargo ship, and the telescopic self-balancing boom assembly is mounted on the rotating assembly of the telescopic base assembly.

[0004] However, the double telescopic crane of this application does not have a control over the extension of the telescopic arm. Therefore, during operation, the telescopic arm may be easily extended even after reaching its maximum length, thereby causing structural damage to the telescopic arm. Therefore, manual observation of the extended length of the telescopic arm is required. When the length approaches the maximum length, manual stop of the extension of the telescopic arm is required. Therefore, the manual workload is increased, and manual observation is prone to errors. Summary of the Invention

[0005] The present invention provides a double telescopic system. The system of the present invention can control the telescopic movement of a double telescopic crane and ensure that the telescopic arm stops extending when it reaches a limited position, thereby protecting the structure of the telescopic arm from being easily damaged.

[0006] To achieve the above-mentioned purpose, the technical solution of the present invention is: a double telescopic system, including a hydraulic control system and a double telescopic crane, the hydraulic control system including a multi-way valve group, an oil tank, an oil pump, a hook limit valve group, an overload protection valve group and a winch control module, the oil tank is connected to one end of the oil pump, the other end of the oil pump is connected to the oil inlet end of the multi-way valve group, and the oil outlet end of the multi-way valve group is connected to the oil tank; the hook limit valve group is connected to the control end of the multi-way valve group, and an overload protection valve group is provided on the hook limit valve group; the winch control module is used to control the double telescopic crane to lift and extend.

[0007] The multi-way valve group includes a rotary valve group, a lifting valve group and a telescopic valve group. The oil inlet ends of the rotary valve group, the lifting valve group and the telescopic valve group are connected to the oil pump, and the oil outlet ends of the rotary valve group, the lifting valve group and the telescopic valve group are connected to the oil tank; the multi-way valve group is used to drive the double telescopic crane.

[0008] The hook limiting valve group includes a first- and second-position two-way directional reversing valve and a second-position two-way directional reversing valve. The P end of the first- and second-position two-way directional reversing valve is connected to the telescopic valve group, the T end of the first- and second-position two-way directional reversing valve is connected to the oil tank, the B end of the first- and second-position two-way directional reversing valve is connected to the oil tank, the control end of the first- and second-position two-way directional reversing valve is connected to the MWL end of the winch control module, and the A end of the first- and second-position two-way directional reversing valve is normally closed.

[0009] The A end of the second two-position two-way reversing valve is connected to the overload protection valve group, the T end of the second two-position two-way reversing valve is connected to the oil tank, the B end of the second two-position two-way reversing valve is connected to the oil tank, the control end of the second two-position two-way reversing valve is connected to the MWL end of the winch control module, and the P end of the second two-position two-way reversing valve is normally closed.

[0010] The overload protection valve group includes an overload first two-position two-way reversing valve, an overload relief valve, an overload three-position seven-way reversing valve, an overload second two-position two-way reversing valve and an overload oil relief pressure stabilizing valve group. The P end of the overload three-position seven-way reversing valve is connected to the oil pump, the T end of the overload three-position seven-way reversing valve is connected to the oil tank, the B end of the overload three-position seven-way reversing valve is connected to the MW1 end of the winch control module, the A end of the overload three-position seven-way reversing valve is connected to the MW2 end of the winch control module, the oil relief end of the overload three-position seven-way reversing valve is connected to the overload oil relief pressure stabilizing valve group, and the overload oil relief pressure stabilizing valve group is also connected to the first two overload The P end of the overload first two-position two-way reversing valve is connected, the B end of the overload first two-position two-way reversing valve is connected to one end of the overload relief valve, the other end of the overload relief valve is connected to the oil tank, the T end of the overload first two-position two-way reversing valve is connected to the oil tank, and the A end of the overload first two-position two-way reversing valve is normally closed; the control end of the overload first two-position two-way reversing valve is connected to the B end of the overload second two-position two-way reversing valve, the MW2 end of the winch control module is also connected to the P end of the overload second two-position two-way reversing valve, the T end of the overload second two-position two-way reversing valve is connected to the oil tank, and the A end of the overload second two-position two-way reversing valve is normally closed.

[0011] The telescopic valve group includes a telescopic three-position seven-way reversing valve, a telescopic one-way valve, a first-level telescopic oil cylinder and a second-level telescopic oil cylinder. One end of the telescopic one-way valve is connected to the oil pump, and the other end of the telescopic one-way valve is connected to the P end of the telescopic three-position seven-way reversing valve. The B end of the telescopic three-position seven-way reversing valve is connected to one end of the first-level telescopic oil cylinder and the second-level telescopic oil cylinder. The A end of the telescopic three-position seven-way reversing valve is connected to the other end of the first-level telescopic oil cylinder and the second-level telescopic oil cylinder. The T end of the telescopic three-position seven-way reversing valve is connected to the oil tank; the oil drain port of the telescopic three-position seven-way reversing valve is connected to the P end of the first-two-position two-way reversing valve with a limit; and a telescopic oil drain pressure-stabilizing valve group is connected between the oil drain port of the telescopic three-position seven-way reversing valve and the P end of the first-two-position two-way reversing valve with a limit.

[0012] When the cam is in operation, the hydraulic control system controls the double telescopic crane to perform telescopic action, and the overload three-position seven-way reversing valve is reversed, connecting the P end of the overload three-position seven-way reversing valve to the B end, so that the oil tank supplies hydraulic oil to the winch control module through the overload three-position seven-way reversing valve. When the double telescopic crane is extended to the upper limit position, the MWL end of the winch control module supplies hydraulic oil to the control end of the first and second position two-way reversing valve of the limit, thereby controlling the reversal of the first and second position two-way reversing valve of the limit, connecting the P end of the first and second position two-way reversing valve to the B end of the first and second position two-way reversing valve of the limit, so that the oil drain port of the telescopic three-position seven-way reversing valve is connected with the oil circuit between the oil tank. As a result, the oil tank continues to supply oil to the first and second telescopic cylinders through the telescopic three-position seven-way reversing valve, and the excess hydraulic oil can flow back to the oil tank through the first and second position two-way reversing valve of the limit, while the first and second telescopic cylinders remain in the extended state, thereby realizing the double telescopic motor When the cam is lifted, the cam is in the process of being retracted and the cam is in the process of being retracted.

[0013] Furthermore, the rotary valve group includes a rotary three-position seven-way directional valve, a rotary one-way valve and a rotary output system, one end of the rotary one-way valve is connected to the oil pump, the other end of the rotary one-way valve is connected to the P end of the rotary three-position seven-way directional valve, the B end of the rotary three-position seven-way directional valve is connected to the SW1 end of the rotary output system, the A end of the rotary three-position seven-way directional valve is connected to the SW2 end of the rotary output system, and the T end of the rotary three-position seven-way directional valve is connected to the oil tank; the SWT end of the rotary output system is connected to the oil tank.

[0014] With the above arrangement, when the double telescopic crane needs to turn, the rotary three-position seven-way directional valve is reversed so that the P end of the rotary three-position seven-way directional valve is connected to the B end, and the A end of the rotary three-position seven-way directional valve is connected to the T end. As a result, the hydraulic oil can flow through the rotary three-position seven-way directional valve to the rotary output system to control the rotary output system and enable the double telescopic motor to turn.

[0015] Furthermore, the lifting valve group includes a lifting three-position seven-way reversing valve, a lifting one-way valve and a lifting cylinder. One end of the lifting one-way valve is connected to the oil pump, and the other end of the lifting one-way valve is connected to the P end of the lifting three-position seven-way reversing valve. The B end of the lifting three-position seven-way reversing valve is connected to one end of the lifting cylinder, and the A end of the lifting three-position seven-way reversing valve is connected to the other end of the lifting cylinder. The lifting three-position seven is connected to the oil tank through the T end of the reversing valve.

[0016] With the above setting, when the telescopic crane needs to be lifted, the lifting three-position seven-way reversing valve is reversed, so that the P end of the lifting three-position seven-way reversing valve is connected to the B end, and the A end of the lifting three-position seven-way reversing valve is connected to the T end, and the hydraulic oil can flow to one end of the lifting cylinder through the lifting three-position seven-way reversing valve, and the hydraulic oil flows back to the oil tank from the other end of the lifting cylinder, thereby driving the lifting cylinder to extend and control the double telescopic crane to rise. When the telescopic crane needs to be lowered, the lifting three-position seven-way reversing valve is reversed, so that the P end of the lifting three-position seven-way reversing valve is connected to the A end, and the B end of the lifting three-position seven-way reversing valve is connected to the T end, and the hydraulic oil can flow to the other end of the lifting cylinder through the lifting three-position seven-way reversing valve, and the hydraulic oil flows back to the oil tank from one end of the lifting cylinder, thereby driving the lifting cylinder to retract and control the double telescopic crane to descend.

[0017] Furthermore, the telescopic oil-drain pressure-stabilizing valve group includes a first telescopic oil-drain shuttle valve, a second telescopic oil-drain shuttle valve, a first telescopic oil-drain relief valve, and a second telescopic oil-drain relief valve. The oil drain port of the telescopic three-position seven-way reversing valve is connected to the oil inlet ends at both ends of the first telescopic oil-drain shuttle valve, the oil outlet end of the first telescopic oil-drain shuttle valve is connected to the oil inlet end of one end of the second telescopic oil-drain shuttle valve, the oil inlet end of the other end of the second telescopic oil-drain shuttle valve is connected to the oil tank, and the oil outlet end of the second telescopic oil-drain shuttle valve is connected to the oil tank; the oil inlet end of one end of the first telescopic oil-drain shuttle valve is also connected to one end of the first telescopic oil-drain relief valve, the other end of the first telescopic oil-drain relief valve is connected to the oil tank, the oil inlet end of the other end of the first telescopic oil-drain shuttle valve is also connected to one end of the second telescopic oil-drain relief valve, the other end of the second telescopic oil-drain relief valve is connected to the oil tank, and the oil inlet port of the first telescopic oil-drain shuttle valve is also connected to the P end of the first two-position two-way reversing valve of the limit position. By setting the telescopic oil-drain pressure-stabilizing valve group, the stability of the oil discharge can be ensured when the telescopic valve group discharges oil. When the telescopic valve group discharges oil, the excess hydraulic oil flows back to the oil tank through the first telescopic oil-drain relief valve and the second telescopic oil-drain relief valve. The two relief valves enable the hydraulic oil to be diverted during oil discharge, thereby making the flow of the hydraulic oil stable and the flow rate not too large.

[0018] Furthermore, the double telescopic crane includes a base, a main arm, a first-level telescopic arm, a second-level telescopic arm and a hook mechanism, one end of the main arm is hinged to the top of the base, a first-level telescopic cylinder is provided in the main arm, and a first-level accommodating groove for accommodating the first-level telescopic arm is provided at the other end of the main arm, the first-level telescopic arm is arranged in the first-level accommodating groove and connected to the first-level telescopic cylinder, a second-level telescopic cylinder is provided in the first-level telescopic arm, a second-level accommodating groove for accommodating the second-level telescopic arm is provided at one end of the first-level telescopic arm, one end of the second-level telescopic arm is arranged in the second-level accommodating groove and connected to the second-level telescopic cylinder, a hook mechanism is provided at the base, a control room is provided on the base, and a rotary output system is also provided on the base; a lifting cylinder is provided at the bottom end of the base, the cylinder body of the lifting cylinder is hinged to the base, and the piston rod of the lifting cylinder is hinged to the main arm.

[0019] With the above arrangement, when the double telescopic crane is working, the staff in the control room controls the first-level telescopic cylinder to drive the first-level telescopic extension according to the position of the cargo to be lifted, and the second-level telescopic cylinder drives the second-level telescopic arm to extend. When the extension length reaches the appropriate position, it stops extending; the staff controls the hook mechanism through the control room to hook the cargo and lift the cargo for transfer, thereby completing the hook work. The process is simple and effective.

[0020] Furthermore, the hook mechanism includes a lifting winch, a cable, a hook pulley, a hook and a lifting limit assembly. The lifting winch is arranged on the main arm, and a hook pulley is provided at the other end of the secondary telescopic arm. One end of the cable is wrapped and connected to the lifting winch, and the other end of the cable is provided on the hook pulley. A hook is provided at the end of the cable, and a lifting limit assembly is provided on the cable located between the hook and the hook pulley.

[0021] The above arrangement is provided with a lifting limit assembly on the cable. When the cable is retracted to a certain length, the cable will be blocked by the lifting limit assembly, so that the hook will not hit the hook pulley and cause structural damage to the hook mechanism.

[0022] Furthermore, the lifting limit assembly includes a lifting limit base, a lifting limit slide and a lifting limit trigger switch, the lifting limit trigger switch is arranged in the lifting limit base through a trigger switch fixing seat, a lifting limit slide is provided below the lifting limit base, a lifting limit groove is provided on the end face of the lifting limit slide away from the lifting limit base, a lifting limit connecting screw is provided in the lifting limit groove, the lifting limit slide is slidably connected to the lifting limit base through the lifting limit connecting screw; the lifting limit trigger switch is in contact with the lifting limit slide; the end of the cable passes through the lifting limit base and is connected to the hook, and the lifting limit trigger switch is electrically connected to the lifting winch.

[0023] With the above arrangement, when the cable is retracted, the cable drives the lifting limit block set on the cable to rise, and when the lifting limit block touches the lifting limit slide, it continues to rise. When the lifting limit slide is driven up by the lifting limit block and touches the lifting limit trigger switch, the lifting limit trigger switch drives the lifting winch to stop working, so that the cable stops rising, preventing the hook from touching the hook pulley.

[0024] Furthermore, the lifting limit screw includes a lifting limit part and a lifting connection part, one end of the lifting connection part is fixedly connected to the lifting limit base, and the other end of the lifting connection part passes through the lifting limit slide and extends into the lifting limit groove, and the lifting limit part is slidably arranged in the lifting limit groove and connected to the lifting connection part.

[0025] The above setting reserves a little space between the lifting limit slide and the lifting limit base through the lifting limit screw, so that when the lifting limit block is driven up by the cable and touches the lifting limit slide, it will not directly collide with the lifting limit base, thereby protecting the structure of the lifting limit assembly from being easily damaged.

[0026] Furthermore, an emergency pump valve group is provided between the oil tank and the winch control module, and the emergency pump valve group includes an emergency manual pump, an emergency one-way valve, a first diaphragm valve and a second diaphragm valve. One end of the emergency manual pump is connected to the oil tank, the other end of the emergency manual pump is connected to one end of the emergency one-way valve, and the other end of the emergency one-way valve is connected to the winch control module; a first diaphragm valve is connected between the emergency manual pump and the oil tank, and a second diaphragm valve is connected between one end of the emergency manual pump and the other end of the emergency one-way valve.

[0027] According to this arrangement, through the setting of the emergency pump valve group, when the double telescopic crane cannot be started normally due to special circumstances, the emergency pump is used to supply oil to the double telescopic crane, so that the double telescopic crane can perform emergency work and prevent accidents.

[0028] Furthermore, a filter valve assembly is provided between the oil outlet of the multi-way valve assembly and the oil tank. The filter valve assembly includes a filter, an oil pressure gauge, and a filter check valve. One end of the filter is connected to the oil outlet of the multi-way valve assembly, and the other end of the filter is connected to the oil tank. The filter check valve and the filter are arranged in parallel, and an oil pressure gauge is also connected to one end of the filter. This arrangement allows the return hydraulic oil to be filtered by the filter valve assembly, ensuring that the hydraulic oil returning to the oil tank is not contaminated with excessive impurities. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a simplified schematic diagram of the hydraulic control system of the present invention.

[0030] Figure 2 It is a schematic diagram of the hook limit valve group and the overload protection valve group of the present invention.

[0031] Figure 3 Schematic diagram of the winch control module and telescopic valve group of the present invention.

[0032] Figure 4 for Figure 3 Magnified view of the middle Z.

[0033] Figure 5 for Figure 2 Enlarged view of Y in the middle.

[0034] Figure 6 It is a schematic diagram of the lifting valve group and the telescopic valve group in the multi-way valve group of the present invention.

[0035] Figure 7 It is a schematic diagram of the lifting valve group and the telescopic valve group of the present invention.

[0036] Figure 8 for Figure 2 Enlarged view of point E in the middle.

[0037] Figure 9 Schematic diagram of the emergency pump valve group of the present invention.

[0038] Figure 10 Schematic diagram of the filter valve group of the present invention.

[0039] Figure 11 It is a structural schematic diagram of the double telescopic crane of the present invention.

[0040] Figure 12 It is a structural schematic diagram of the hook mechanism of the present invention.

[0041] Figure 13 It is a structural schematic diagram of the lifting limit assembly of the present invention. DETAILED DESCRIPTION

[0042] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0043] like Figures 1 to 13 As shown, a double telescopic system includes a hydraulic control system 1 and a double telescopic crane 2 (in Figure 11 As shown in the figure, the hydraulic control system 1 includes a multi-way valve group 3, an oil tank 10, an oil pump 11, a hook limit valve group 4, an overload protection valve group 5 and a winch control module 12. The oil tank 10 is connected to one end of the oil pump 11, and the other end of the oil pump 11 is connected to the oil inlet end of the multi-way valve group 3, and the oil outlet end of the multi-way valve group 3 is connected to the oil tank 10; the hook limit valve group 4 is connected to the control end of the multi-way valve group 3, and the overload protection valve group 5 is provided on the hook limit valve group 4; the winch control module is used to control the double telescopic crane to lift and extend.

[0044] The multi-way valve group 3 includes a rotary valve group 31, a lifting valve group 32 and a telescopic valve group 33. The oil inlet ends of the rotary valve group 31, the lifting valve group 32 and the telescopic valve group 33 are connected to the oil pump 11, and the oil outlet ends of the rotary valve group 31, the lifting valve group 32 and the telescopic valve group 33 are connected to the oil tank 10; the multi-way valve group 3 is used to drive the double telescopic crane 2.

[0045] like Figure 1 and Figure 2 As shown, the hook limiting valve group 4 includes a first-two-position two-way directional control valve 41 and a second-two-position two-way directional control valve 42, the P end of the first-two-position two-way directional control valve 41 is connected to the telescopic valve group 33, the T end of the first-two-position two-way directional control valve 41 is connected to the oil tank 10, the B end of the first-two-position two-way directional control valve 41 is connected to the oil tank 10, the control end 41K of the first-two-position two-way directional control valve 41 is connected to the MWL end of the winch control module 12, and the A end of the first-two-position two-way directional control valve 41 is normally closed.

[0046] The A end of the second two-position two-way reversing valve 42 is connected to the overload protection valve group 5, the T end of the second two-position two-way reversing valve 42 is connected to the oil tank 10, the B end of the second two-position two-way reversing valve 42 is connected to the oil tank 10, the control end 42K of the second two-position two-way reversing valve 42 is connected to the MWL end of the winch control module 12, and the P end of the second two-position two-way reversing valve 42 is normally closed.

[0047] like Figures 1 to 4 As shown, the overload protection valve group 5 includes an overload first two-position two-way reversing valve 51, an overload relief valve 52, an overload three-position seven-way reversing valve 53, an overload second two-position two-way reversing valve 54 and an overload oil relief pressure stabilizing valve group 55, the P end of the overload three-position seven-way reversing valve 53 is connected to the oil pump 11, the T end of the overload three-position seven-way reversing valve 53 is connected to the oil tank 10, the B end of the overload three-position seven-way reversing valve 53 is connected to the MW1 end of the winch control module 12, the A end of the overload three-position seven-way reversing valve 53 is connected to the MW2 end of the winch control module 12, and the overload three-position seven-way reversing valve 53 is connected to the MW3 end of the winch control module 12. The oil drain end 53K of the directional valve 53 is connected to the overload oil drain pressure stabilizing valve group 55, and the overload oil drain pressure stabilizing valve group 55 is also connected to the P end of the overload first two-position two-way reversing valve 51. The B end of the overload first two-position two-way reversing valve 51 is connected to one end of the overload relief valve 52, and the other end of the overload relief valve 52 is connected to the oil tank 10. The T end of the overload first two-position two-way reversing valve 51 is connected to the oil tank 10, and the A end of the overload first two-position two-way reversing valve 51 is normally closed; the control end 51K of the overload first two-position two-way reversing valve 51 is connected to the overload second two-position two-way reversing valve 54 (at Figure 4The B end of the winch control module 12 is connected to the P end of the second two-position two-way reversing valve 54 of the overload, and the T end of the second two-position two-way reversing valve 54 of the overload is connected to the oil tank 10. The A end of the second two-position two-way reversing valve 54 of the overload is normally closed.

[0048] like Figure 2 and Figure 5 As shown, the overload oil relief pressure stabilizing valve group 55 includes a first overload oil relief shuttle valve 551, a second overload oil relief shuttle valve 552, a first overload oil relief valve 553 and a second overload oil relief valve 554. The oil relief port 53K of the overload three-position seven-way reversing valve 53 is connected to the oil inlet ends 551P at both ends of the first overload oil relief shuttle valve 551, the oil outlet end 551T of the first overload oil relief shuttle valve 551 is connected to the oil inlet end 552P at one end of the second overload oil relief shuttle valve 552, and the oil inlet end 552P at the other end of the second overload oil relief shuttle valve 552 is connected to the oil tank 10 The oil outlet end of the second overload oil relief shuttle valve 552 is connected to the oil tank; the oil inlet end of one end of the first overload oil relief shuttle valve 551 is also connected to one end of the first overload oil relief valve 553, and the other end of the first overload oil relief valve 553 is connected to the oil tank 10. The oil inlet end of the other end of the first overload oil relief shuttle valve 551 is also connected to one end of the second overload oil relief valve 554, and the other end of the second overload oil relief valve 554 is connected to the oil tank 10. The oil inlet port 53K of the first overload oil relief shuttle valve is also connected to the P end of the first two-position two-way reversing valve of overload. By setting the overload oil relief pressure stabilizing valve group, the oil relief stability can be ensured when the overload valve group is relief. When the overload valve group is relief, the excess hydraulic oil flows back to the oil tank through the first overload oil relief valve and the second overload oil relief valve. The two relief valves enable the hydraulic oil to be diverted during oil relief, thereby making the hydraulic oil flow stable and the flow rate not too large.

[0049] like Figures 1 to 5As shown, the telescopic valve group 33 includes a telescopic three-position seven-way reversing valve 331, a telescopic one-way valve 332, a first-stage telescopic oil cylinder 333 and a second-stage telescopic oil cylinder 334. One end of the telescopic one-way valve 332 is connected to the oil pump 11, and the other end of the telescopic one-way valve 332 is connected to the P end of the telescopic three-position seven-way reversing valve 331. The B end of the telescopic three-position seven-way reversing valve 331 is connected to one end of the first-stage telescopic oil cylinder 333 and the second-stage telescopic oil cylinder 334. The A end of the telescopic three-position seven-way reversing valve 331 is connected to the other end of the first-stage telescopic oil cylinder 333 and the second-stage telescopic oil cylinder 334. In this embodiment, one end of the primary telescopic cylinder 333 and the secondary telescopic cylinder 334 is indicated by C, and the other end of the primary telescopic cylinder 333 and the secondary telescopic cylinder 334 is indicated by D. The T end of the telescopic 3 / 7-way reversing valve 331 is connected to the oil tank 10; the oil drain port 331K of the telescopic 3 / 7-way reversing valve 331 is connected to the P end of the first-position, two-way, two-way limiting reversing valve 41; and a telescopic oil drain pressure-stabilizing valve assembly 335 is connected between the oil drain port 331K of the telescopic 3 / 7-way reversing valve 331 and the P end of the first-position, two-way, two-way limiting reversing valve 41. In this embodiment, a balancing oil circuit is connected between the telescopic 3 / 7-way reversing valve 331 and the primary telescopic cylinder 333 and the secondary telescopic cylinder 334. This balancing oil circuit is used to maintain a stable state of hydraulic oil output to the primary and secondary telescopic cylinders. The specific oil circuit is conventional and will not be described in detail below.

[0050] When the above structure is in operation, the hydraulic control system 1 controls the double telescopic crane 2 to perform telescopic action, and the overload three-position seven-way reversing valve 53 is reversed, and the P end of the overload three-position seven-way reversing valve 53 is connected to the B end, so that the oil tank 10 delivers hydraulic oil to the winch control module 12 through the overload three-position seven-way reversing valve 53. When the double telescopic crane 2 is extended to the upper limit, the MWL end of the winch control module 12 delivers hydraulic oil to the control end 41K of the first two-position two-way reversing valve 41 of the limit, thereby controlling the reversal of the first two-position two-way reversing valve 41 of the limit, and connects the P end of the first two-position two-way reversing valve 41 of the limit, so that the telescopic three-position seven-way reversing valve 41 is reversing. The oil drain port 331K of the valve 331 is connected to the oil circuit between the oil tank 10, so that the oil tank 10 continues to supply oil to the first-stage telescopic oil cylinder 333 and the second-stage telescopic oil cylinder 334 through the telescopic three-position seven-way reversing valve 331, and the excess hydraulic oil can flow back to the oil tank 10 through the first- and second-position two-way reversing valve 41, while the first-stage telescopic oil cylinder 333 and the second-stage telescopic oil cylinder 334 remain in the extended state. In this embodiment, the hydraulic control system pre-sets the preset value of the upper extension limit position of the double telescopic crane. When the double telescopic crane reaches the preset value of the upper extension limit position, the winch control module controls the first- and second-position two-way reversing valve to switch and drain the oil to realize the extension control of the double telescopic crane, thereby The double telescopic motor 2 is kept in extension and will not exceed the upper limit of extension; when the double telescopic crane 2 reaches the upper limit of lifting, the overload second two-position two-way reversing valve 54 is reversed, so that the P end of the overload second two-position two-way reversing valve 54 is connected to the B end, and the MW2 end of the winch control module 12 can deliver hydraulic oil to the control end 51K of the overload first two-position two-way reversing valve 51 through the overload second two-position two-way reversing valve 54, thereby controlling the reversal of the overload first two-position two-way reversing valve 51, connecting the P end of the overload first two-position two-way reversing valve 51 to the B end, thereby, the oil tank 10 continues to supply oil to the winch control module 12 through the overload three-position seven-way reversing valve 53, and the excess hydraulic The oil can flow back to the oil tank 10 from the overload first two-position two-way reversing valve 51, thereby controlling the lifting of the double telescopic crane 2 so that it will not exceed the upper lifting limit. In this embodiment, the hydraulic control system pre-sets a preset value of the upper lifting limit of the double telescopic crane. When the double telescopic crane reaches the preset value of the upper lifting limit, the overload second two-position two-way reversing valve is reversed, so that the winch control module controls the overload first two-position two-way reversing valve to reverse and drain oil to realize the lifting control of the double telescopic crane. Through the above settings, it is ensured that the double telescopic crane will not cause structural damage to the telescopic arm due to excessive extension during operation, and it can also be ensured that the double telescopic crane will not exceed the upper lifting limit when lifting.

[0051] like Figure 6 and Figure 7As shown, the rotary valve group 31 includes a rotary three-position seven-way reversing valve 311, a rotary one-way valve 312 and a rotary output system 313, one end of the rotary one-way valve 312 is connected to the oil pump 11, the other end of the rotary one-way valve 312 is connected to the P end of the rotary three-position seven-way reversing valve 311, the B end of the rotary three-position seven-way reversing valve 311 is connected to the SW1 end of the rotary output system 313, the A end of the rotary three-position seven-way reversing valve 311 is connected to the SW2 end of the rotary output system 313, the T end of the rotary three-position seven-way reversing valve 311 is connected to the oil tank 10; the SWT end of the rotary output system 313 is connected to the oil tank 10.

[0052] With the above arrangement, when the dual telescopic crane needs to turn, the rotary three-position seven-way reversing valve 311 is reversed, so that the P end of the rotary three-position seven-way reversing valve 311 is connected to the B end, and the A end of the rotary three-position seven-way reversing valve 311 is connected to the T end. As a result, the hydraulic oil can flow through the rotary three-position seven-way reversing valve to the rotary output system 313 to control the rotary output system 313 so that the dual telescopic motor can achieve steering.

[0053] like Figure 6 and Figure 7 As shown, the lifting valve group 32 includes a lifting three-position seven-way reversing valve 321, a lifting one-way valve 322 and a lifting cylinder 323, one end of the lifting one-way valve 322 is connected to the oil pump 11, and the other end of the lifting one-way valve 322 is connected to the P end of the lifting three-position seven-way reversing valve 321, the B end of the lifting three-position seven-way reversing valve 321 is connected to one end 3231 of the lifting cylinder 323, the A end of the lifting three-position seven-way reversing valve 321 is connected to the other end 3232 of the lifting cylinder 323, and the lifting three-position seven-way is connected to the oil tank 10 through the T end of the reversing valve 321.

[0054] With the above configuration, when the telescopic crane needs to be lifted, the lifting three-position seven-way reversing valve 321 is reversed, so that the P end of the lifting three-position seven-way reversing valve 321 is connected to the B end, and the A end of the lifting three-position seven-way reversing valve 321 is connected to the T end, and the hydraulic oil can flow to one end of the lifting cylinder 323 through the lifting three-position seven-way reversing valve 321, and the hydraulic oil flows back to the oil tank 10 from the other end of the lifting cylinder 323, thereby driving the lifting cylinder 323 to extend and control the double telescopic crane. When the telescopic crane needs to descend, the lifting three-position seven-way reversing valve 321 is reversed, so that the P end of the lifting three-position seven-way reversing valve 321 is connected to the A end, and the B end of the lifting three-position seven-way reversing valve 321 is connected to the T end, and the hydraulic oil can flow to the other end of the lifting cylinder 323 through the lifting three-position seven-way reversing valve 321, and the hydraulic oil flows back to the oil tank 10 from one end of the lifting cylinder 323, thereby driving the lifting cylinder 323 to retract and control the descent of the double telescopic crane.

[0055] like Figure 2 and Figure 8As shown, the telescopic oil drain pressure stabilizing valve group 335 includes a first telescopic oil drain shuttle valve 3351, a second telescopic oil drain shuttle valve 3352, a first telescopic oil drain relief valve 3353, and a second telescopic oil drain relief valve 3354. The oil drain port 331K of the telescopic three-position seven-way reversing valve 331 is connected to the oil inlet ends 3351P at both ends of the first telescopic oil drain shuttle valve 3351, the oil outlet end 3351T of the first telescopic oil drain shuttle valve 3351 is connected to the oil inlet end 3352P of one end 3352 of the second telescopic oil drain shuttle valve, and the oil inlet end 3352P of the other end of the second telescopic oil drain shuttle valve 3352P is connected to the oil tank. 10, the oil outlet end of the second telescopic oil drain shuttle valve 3352P is connected to the oil tank 10; the oil inlet end of one end of the first telescopic oil drain shuttle valve 3351 is also connected to one end of the first telescopic oil drain overflow valve 3353, the other end of the first telescopic oil drain overflow valve 3353 is connected to the oil tank 10, the oil inlet end of the other end of the first telescopic oil drain shuttle valve 3351 is also connected to one end of the second telescopic oil drain overflow valve 3354, the other end of the second telescopic oil drain overflow valve 3354 is connected to the oil tank 10, and the oil inlet port of the first telescopic oil drain shuttle valve 3351 is also connected to the P end of the first two-position two-way reversing valve 41 of the limit. By setting the telescopic oil-drain pressure-stabilizing valve group, the stability of the oil discharge can be ensured when the telescopic valve group discharges oil. When the telescopic valve group discharges oil, the excess hydraulic oil flows back to the oil tank through the first telescopic oil-drain relief valve and the second telescopic oil-drain relief valve. The two relief valves enable the hydraulic oil to be diverted during oil discharge, thereby making the flow of the hydraulic oil stable and the flow rate not too large.

[0056] like Figure 9 As shown, an emergency pump valve group 6 is provided between the oil tank 10 and the winch control module 12, and the emergency pump valve group 6 includes an emergency manual pump 61, an emergency one-way valve 62, a first diaphragm valve 63 and a second diaphragm valve 64. One end of the emergency manual pump 61 is connected to the oil tank 10, and the other end of the emergency manual pump 61 is connected to one end of the emergency one-way valve 62, and the other end of the emergency one-way valve 62 is connected to the winch control module 12; a first diaphragm valve 63 is connected between the emergency manual pump 61 and the oil tank 10, and a second diaphragm valve 64 is connected between one end of the emergency manual pump 61 and the other end of the emergency one-way valve 62.

[0057] According to this arrangement, through the setting of the emergency pump valve group, when the double telescopic crane cannot be started normally due to special circumstances, the emergency pump is used to supply oil to the double telescopic crane, so that the double telescopic crane can perform emergency work and prevent accidents.

[0058] like Figure 10As shown, a filter valve assembly 7 is provided between the oil outlet of the multi-way valve assembly 3 and the oil tank 10. The filter valve assembly 7 includes a filter 71, an oil pressure gauge 72, and a filter check valve 73. One end of the filter 71 is connected to the oil outlet of the multi-way valve assembly 3, and the other end of the filter 71 is connected to the oil tank 10. The filter check valve 73 is arranged in parallel with the filter 71, and an oil pressure gauge 72 is also connected to one end of the filter 71. With this arrangement, the returning hydraulic oil is filtered by the filter valve assembly, ensuring that the hydraulic oil returning to the oil tank is not contaminated with excessive impurities.

[0059] like Figure 11 As shown, the double telescopic crane 2 includes a base 21, a main arm 22, a first-level telescopic arm 23, a second-level telescopic arm 24 and a hook mechanism 25. One end of the main arm 22 is hinged to the top of the base 21, a first-level telescopic oil cylinder 333 is provided in the main arm 22, and a first-level accommodating groove 221 for accommodating the first-level telescopic arm 23 is provided at the other end of the main arm 22. The first-level telescopic arm 23 is arranged in the first-level accommodating groove 221 and is connected to the first-level telescopic oil cylinder 333. A second-level telescopic oil cylinder 334 is provided in the first-level telescopic arm 23. One end of the primary telescopic arm 23 is provided with a secondary accommodating groove 231 for accommodating the secondary telescopic arm 24. One end of the secondary telescopic arm 24 is positioned within the secondary accommodating groove 231 and connected to a secondary telescopic cylinder 334. The other end of the secondary telescopic arm 24 is provided with a hook mechanism 25. A lifting cylinder 323 is provided at the bottom end of the base 21. The cylinder body of the lifting cylinder 323 is hinged to the base 21, and the piston rod of the lifting cylinder 323 is hinged to the main arm 22. A control chamber (not shown) is provided on the base 21. In this embodiment, the control chamber is used to operate the dual telescopic hooks.

[0060] The lifting cylinder 323 is controlled by the lifting valve group 32 to achieve the raising or lowering of the dual telescopic motor 2.

[0061] A rotary mechanism (not shown) is also provided on the base 21. The rotary mechanism is connected to the rotary output system and is controlled by a rotary valve group to realize the rotation direction of the dual telescopic motors. In this embodiment, the rotary mechanism is a common rotating device and will not be described in detail below.

[0062] With the above arrangement, when the double telescopic crane 2 is working, the staff in the control room 20 controls the first-level telescopic cylinder 333 to drive the first-level telescopic arm 23 to extend, and the second-level telescopic cylinder 334 to drive the second-level telescopic arm 24 to extend according to the position of the cargo to be lifted. When the extended length reaches the appropriate position, the extension is stopped; the staff controls the hook mechanism 25 through the control room 20 to hook up the cargo and lift the cargo for transfer, thereby completing the hook work. The process is simple and effective.

[0063] like Figure 11 and Figure 12As shown, the hook mechanism 25 includes a lifting winch 251, a cable 252, a hook pulley 253, a hook 254 and a lifting limit assembly 26. The lifting winch 251 is arranged on the main arm 22, and a hook pulley 253 is provided at the other end of the secondary telescopic arm 24. One end of the cable 252 is wound around and connected to the lifting winch 251, and the other end of the cable 252 is provided on the hook pulley 253. A hook 254 is provided at the end of the cable 252, and a lifting limit assembly 26 is provided on the cable 252 located between the hook 254 and the hook pulley 253.

[0064] In the above arrangement, a lifting limit assembly 26 is provided on the cable 252. When the cable 252 is retracted to a certain length, the cable 252 will be blocked by the lifting limit assembly 26, so that the hook 254 will not hit the hook pulley 253 and cause structural damage to the hook mechanism 25.

[0065] like Figures 11 to 13 As shown, the lifting limit assembly 26 includes a lifting limit base 261, a lifting limit block 262, a lifting limit slide 263 and a lifting limit trigger switch 264. The lifting limit trigger switch 264 is arranged in the lifting limit base 261 through a trigger switch fixing seat 2641. A lifting limit slide 263 is provided below the lifting limit base 261. A lifting limit groove 2631 is provided on the end surface of the lifting limit slide 263 away from the lifting limit base 261. A lifting limit connecting screw 265 is provided in the lifting limit groove 2631. The lifting limit slide 263 is connected to the lifting limit base 261 through the lifting limit slide 263. The lifting limit connecting screw 265 is slidably connected to the lifting limit base 261, and the lifting limit trigger switch 264 is in contact with the lifting limit slide 263; the end of the cable 252 passes through the lifting limit base 261 and is connected to the hook 254, and a lifting limit block 262 is provided on the cable 252 between the hook 254 and the lifting limit slide 263. The lifting limit trigger switch 264 is electrically connected to the lifting winch 251. In this embodiment, the winch control module drives the lifting winch to realize the recovery and extension of the cable, and the winch control module is electrically connected to the second two-position two-way reversing valve of the overload.

[0066] With the above arrangement, when the cable 252 is retracted, the cable 252 drives the lifting limit block 262 set on the cable 252 to rise, and when the lifting limit block 262 touches the lifting limit slide 263, it continues to rise. When the lifting limit slide 263 is driven to rise by the lifting limit block 262 and touches the lifting limit trigger switch 264, the lifting limit trigger switch 264 sends a signal to the winch control module, so that the winch control module drives the overload second two-position two-way reversing valve to reverse, and then the winch control module controls the overload first two-position two-way reversing valve to reverse, thereby allowing excess hydraulic oil to flow back to the oil tank, so that the lifting winch 251 stops working and the cable 252 stops rising, preventing the hook 254 from touching the hook pulley 253.

[0067] like Figure 13 As shown, the lifting limit screw 265 includes a lifting limit part 2651 and a lifting connection part 2652, one end of the lifting connection part 2652 is fixedly connected to the lifting limit base 261, and the other end of the lifting connection part 2652 passes through the lifting limit slide 263 and extends into the lifting limit slot 2631, and the lifting limit part 2651 is slidably set in the lifting limit slot 2631 and connected to the lifting connection part 2652.

[0068] The above arrangement reserves a little space between the lifting limit slide 263 and the lifting limit base 261 through the lifting limit screw 265, so that when the lifting limit block 262 is driven up by the cable 252 and touches the lifting limit slide 263, it will not directly collide with the lifting limit base 261, thereby protecting the structure of the lifting limit assembly 26 from being easily damaged.

Claims

1. A double telescopic system, comprising a hydraulic control system and a double telescopic crane, characterized in that: The hydraulic control system includes a multi-way valve group, an oil tank, an oil pump, a hook limit valve group, an overload protection valve group and a winch control module. The oil tank is connected to one end of the oil pump, the other end of the oil pump is connected to the oil inlet end of the multi-way valve group, and the oil outlet end of the multi-way valve group is connected to the oil tank; the hook limit valve group is connected to the control end of the multi-way valve group, and the hook limit valve group is provided with an overload protection valve group; the winch control module is used to control the lifting and extension of the double telescopic crane; The multi-way valve group includes a rotary valve group, a lifting valve group and a telescopic valve group. The oil inlet ends of the rotary valve group, the lifting valve group and the telescopic valve group are connected to the oil pump, and the oil outlet ends of the rotary valve group, the lifting valve group and the telescopic valve group are connected to the oil tank; the multi-way valve group is used to drive the double telescopic crane; The hook limit valve group includes a first-position two-way directional control valve and a second-position two-way directional control valve, the P end of the first-position two-way directional control valve is connected to the telescopic valve group, the T end of the first-position two-way directional control valve is connected to the oil tank, the B end of the first-position two-way directional control valve is connected to the oil tank, the control end of the first-position two-way directional control valve is connected to the MWL end of the winch control module, and the A end of the first-position two-way directional control valve is normally closed; The A end of the second two-position two-way reversing valve is connected to the overload protection valve group, the T end of the second two-position two-way reversing valve is connected to the oil tank, the B end of the second two-position two-way reversing valve is connected to the oil tank, the control end of the second two-position two-way reversing valve is connected to the MWL end of the winch control module, and the P end of the second two-position two-way reversing valve is normally closed; The overload protection valve group includes an overload first two-position two-way reversing valve, an overload relief valve, an overload three-position seven-way reversing valve, an overload second two-position two-way reversing valve and an overload oil relief pressure stabilizing valve group. The P end of the overload three-position seven-way reversing valve is connected to the oil pump, the T end of the overload three-position seven-way reversing valve is connected to the oil tank, the B end of the overload three-position seven-way reversing valve is connected to the MW1 end of the winch control module, the A end of the overload three-position seven-way reversing valve is connected to the MW2 end of the winch control module, the oil relief end of the overload three-position seven-way reversing valve is connected to the overload oil relief pressure stabilizing valve group, and the overload oil relief pressure stabilizing valve group is also connected to the first two overload The P end of the overload first two-position two-way reversing valve is connected, the B end of the overload first two-position two-way reversing valve is connected to one end of the overload relief valve, the other end of the overload relief valve is connected to the oil tank, the T end of the overload first two-position two-way reversing valve is connected to the oil tank, and the A end of the overload first two-position two-way reversing valve is normally closed; the control end of the overload first two-position two-way reversing valve is connected to the B end of the overload second two-position two-way reversing valve, the MW2 end of the winch control module is also connected to the P end of the overload second two-position two-way reversing valve, the T end of the overload second two-position two-way reversing valve is connected to the oil tank, and the A end of the overload second two-position two-way reversing valve is normally closed; The telescopic valve group includes a telescopic three-position seven-way reversing valve, a telescopic one-way valve, a first-level telescopic oil cylinder and a second-level telescopic oil cylinder. One end of the telescopic one-way valve is connected to the oil pump, and the other end of the telescopic one-way valve is connected to the P end of the telescopic three-position seven-way reversing valve. The B end of the telescopic three-position seven-way reversing valve is connected to one end of the first-level telescopic oil cylinder and the second-level telescopic oil cylinder. The A end of the telescopic three-position seven-way reversing valve is connected to the other end of the first-level telescopic oil cylinder and the second-level telescopic oil cylinder. The T end of the telescopic three-position seven-way reversing valve is connected to the oil tank; the oil drain port of the telescopic three-position seven-way reversing valve is connected to the P end of the first-two-position two-way reversing valve with a limit; and a telescopic oil drain pressure-stabilizing valve group is connected between the oil drain port of the telescopic three-position seven-way reversing valve and the P end of the first-two-position two-way reversing valve with a limit.

2. A double telescopic system according to claim 1, characterized in that: The rotary valve group includes a rotary three-position seven-way reversing valve, a rotary check valve and a rotary output system. One end of the rotary check valve is connected to the oil pump, and the other end of the rotary check valve is connected to the P end of the rotary three-position seven-way reversing valve. The B end of the rotary three-position seven-way reversing valve is connected to the SW1 end of the rotary output system, the A end of the rotary three-position seven-way reversing valve is connected to the SW2 end of the rotary output system, and the T end of the rotary three-position seven-way reversing valve is connected to the oil tank; the SWT end of the rotary output system is connected to the oil tank.

3. The double telescopic system according to claim 1, characterized in that: The lifting valve group includes a lifting three-position seven-way reversing valve, a lifting one-way valve and a lifting cylinder. One end of the lifting one-way valve is connected to the oil pump, and the other end of the lifting one-way valve is connected to the P end of the lifting three-position seven-way reversing valve. The B end of the lifting three-position seven-way reversing valve is connected to one end of the lifting cylinder, and the A end of the lifting three-position seven-way reversing valve is connected to the other end of the lifting cylinder. The lifting three-position seven is connected to the oil tank through the T end of the reversing valve.

4. The double telescopic system according to claim 1, characterized in that: The telescopic oil-drain pressure-stabilizing valve group includes a first telescopic oil-drain shuttle valve, a second telescopic oil-drain shuttle valve, a first telescopic oil-drain relief valve, and a second telescopic oil-drain relief valve. The oil drain port of the telescopic three-position seven-way reversing valve is connected to the oil inlets at both ends of the first telescopic oil-drain shuttle valve, the oil outlet end of the first telescopic oil-drain shuttle valve is connected to the oil inlet end of one end of the second telescopic oil-drain shuttle valve, the oil inlet end of the other end of the second telescopic oil-drain shuttle valve is connected to the oil tank, and the oil outlet end of the second telescopic oil-drain shuttle valve is connected to the oil tank; the oil inlet end of one end of the first telescopic oil-drain shuttle valve is also connected to one end of the first telescopic oil-drain relief valve, the other end of the first telescopic oil-drain relief valve is connected to the oil tank, the oil inlet end of the other end of the first telescopic oil-drain shuttle valve is also connected to one end of the second telescopic oil-drain relief valve, the other end of the second telescopic oil-drain relief valve is connected to the oil tank, and the oil inlet port of the first telescopic oil-drain shuttle valve is also connected to the P end of the first two-position two-way reversing valve of the limit position.

5. The double telescopic system according to claim 1, characterized in that: The double telescopic crane includes a base, a main arm, a primary telescopic arm, a secondary telescopic arm and a hook mechanism, one end of the main arm is hinged to the top of the base, a primary telescopic cylinder is provided in the main arm, a primary accommodating groove for accommodating the primary telescopic arm is provided at the other end of the main arm, the primary telescopic arm is arranged in the primary accommodating groove and connected to the primary telescopic cylinder, a secondary telescopic cylinder is provided in the primary telescopic arm, a secondary accommodating groove for accommodating the secondary telescopic arm is provided at one end of the primary telescopic arm, one end of the secondary telescopic arm is arranged in the secondary accommodating groove and connected to the secondary telescopic cylinder, a hook mechanism is provided at the other end of the secondary telescopic arm, a control room is provided on the base, and a rotary output system is also provided on the base; A lifting oil cylinder is provided at the bottom end of the base, a cylinder body of the lifting oil cylinder is hinged on the base, and a piston rod of the lifting oil cylinder is hinged on the main arm.

6. The double telescopic system according to claim 5, characterized in that: The hook mechanism includes a lifting winch, a cable, a hook pulley, a hook and a lifting limit assembly. The lifting winch is arranged on the main arm, and a hook pulley is provided at the other end of the secondary telescopic arm. One end of the cable is wound and connected to the lifting winch, and the other end of the cable is provided on the hook pulley. A hook is provided at the end of the cable, and a lifting limit assembly is provided on the cable located between the hook and the hook pulley.

7. The double telescopic system according to claim 6, characterized in that: The lifting limit assembly includes a lifting limit base, a lifting limit slide and a lifting limit trigger switch. The lifting limit trigger switch is arranged in the lifting limit base through a trigger switch fixing seat. A lifting limit slide is provided below the lifting limit base. A lifting limit groove is provided on the end face of the lifting limit slide away from the lifting limit base. A lifting limit connecting screw is provided in the lifting limit groove. The lifting limit slide is slidably connected to the lifting limit base through the lifting limit connecting screw; the lifting limit trigger switch is in contact with and connected to the lifting limit slide; the end of the cable passes through the lifting limit base and is connected to the hook, and the lifting limit trigger switch is electrically connected to the lifting winch.

8. The double telescopic system according to claim 7, characterized in that: The lifting limit screw includes a lifting limit part and a lifting connection part, one end of the lifting connection part is fixedly connected to the lifting limit base, and the other end of the lifting connection part passes through the lifting limit slide and extends into the lifting limit groove, and the lifting limit part is slidably arranged in the lifting limit groove and connected to the lifting connection part.

9. The double telescopic system according to claim 1, characterized in that: An emergency pump valve group is provided between the oil tank and the winch control module, and the emergency pump valve group includes an emergency manual pump, an emergency one-way valve, a first diaphragm valve and a second diaphragm valve. One end of the emergency manual pump is connected to the oil tank, the other end of the emergency manual pump is connected to one end of the emergency one-way valve, and the other end of the emergency one-way valve is connected to the winch control module; a first diaphragm valve is connected between the emergency manual pump and the oil tank, and a second diaphragm valve is connected between one end of the emergency manual pump and the other end of the emergency one-way valve.

10. The double telescopic system according to claim 1, characterized in that: A filter valve group is provided between the oil outlet end of the multi-way valve group and the oil tank. The filter valve group includes a filter, an oil pressure gauge and a filter check valve. One end of the filter is connected to the oil outlet end of the multi-way valve group, and the other end of the filter is connected to the oil tank. The filter check valve is arranged in parallel with the filter, and an oil pressure gauge is also connected to one end of the filter.

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