A hydraulic control system and control method for an insulated aerial work platform

Abstract

This application provides a hydraulic control system and method for an insulated aerial work platform. The system adopts electro-hydraulic speed proportional intelligent control, offering excellent handling performance, low risk of overheating and oil leakage, and high reliability. The system includes a lower vehicle control subsystem, an upper vehicle control subsystem, a platform control subsystem, and an insulated pipeline device, achieving motion control through hydraulic pump units and control valve units. The hydraulic control method covers steps such as vehicle inactivity, operation of the upper vehicle boom and lower vehicle outriggers, rapid extension of one boom, platform power supply, insulated pipeline pressure control, automatic platform leveling, and emergency retraction. The advantages of this application are that it achieves automatic interlock protection between the outriggers and boom, rapid boom extension, automatic electro-hydraulic leveling of the platform, direct generator charging control, and prevents reduction in dielectric strength of the wiring within the insulated boom, as well as emergency retraction in case of electrical control failure, effectively improving operational safety and efficiency.

Description

Technical Field

[0001] This application relates to the field of hydraulic control technology for aerial work platforms, and specifically to a hydraulic control system and control method for an insulated aerial work platform. Background Technology

[0002] With the gradual improvement of people's living standards, higher requirements have been placed on the reliability and stability of power distribution network operation, leading to a period of rapid development in live-line working technology. Insulated aerial work platforms, as an important tool for live-line work, have been widely used in my country's power system. Currently, some insulated aerial work platforms use electro-hydraulic proportional control systems, while others use fully hydraulic control systems. Regardless of the control system used, the safety of personnel operating on the work platform must be guaranteed, especially the safety of insulated aerial work platforms during live-line work, which must be fully ensured.

[0003] Insulated aerial work platforms are generally divided into off-vehicle operation and on-vehicle operation. Off-vehicle operation refers to the extension and retraction of the outriggers, while on-vehicle operation refers to the raising, lowering, extension, and rotation of the boom. Aerial work platforms carry personnel to work at heights, so good overall stability is required. The stability of the superstructure is ensured by the hydraulic outriggers on the off-vehicle. Operating the boom without extending the outriggers may cause the vehicle's center of gravity to shift, potentially leading to rollovers or other dangerous accidents. Another scenario is when the outriggers are extended, the boom has detached from the boom support, and personnel are already performing aerial work; mistakenly retracting the outriggers on the off-vehicle in this situation could also cause a rollover. Boom operation typically includes controls at the turntable and platform. Whether operating the outriggers from the off-vehicle, the boom from the turntable, or the boom from the platform, the safety of all vehicle operations must be ensured.

[0004] Patent CN105288909A describes an automatic interlocking device for raising and lowering a fire truck with dual protection. The technical solution involves using a hydraulic pilot unloading valve group, a mechanical interlock limit plate, a self-resetting cylinder, and sensors, among other components. This solution suffers from complex design, high manufacturing costs, and difficult assembly. Furthermore, if the outriggers on the lower vehicle malfunction, it not only restricts the movement of the upper vehicle boom and the retraction of the outriggers, but also prevents the lower vehicle from extending its outriggers to maintain vehicle stability. In other words, all movements of the upper vehicle boom and the lower vehicle outriggers become impossible, posing a certain risk to on-site rescue operations.

[0005] Patent CN201864543U discloses a leg interlocking device for an aerial work platform. The technical solution involves using inductive proximity switches, leg interlock valves, leg signal valves, and an adapter power supply. The problem is that when the outriggers on the lower vehicle are not properly extended or experience a "soft leg" (a sudden, loose leg), all movements of both the lower and upper vehicles are restricted. However, when the upper vehicle leaves the boom support, there is no restriction preventing the retraction of the outriggers. In simpler terms, without extending the outriggers, only the upper vehicle is locked to prevent boom movement. Conversely, when the boom leaves the boom support and the upper vehicle is operating, it cannot lock the lower vehicle to prevent outrigger movement, failing to achieve simultaneous automatic interlocking between the upper and lower vehicles, posing a significant safety hazard. Another problem is that if a "soft leg" occurs, the lower vehicle cannot extend the outriggers to ensure vehicle stability, and the upper vehicle is in a restricted movement state and cannot be retracted, causing problems for on-site operations, obstruction of the walkway, and preventing workers on the platform from descending to the ground.

[0006] The aforementioned patents only involve interlocked control of the loading and unloading actions, without addressing the power supply control for the insulated aerial work platform, the boom extension control for high-flow systems, or, in particular, the special requirements for insulated aerial work platforms used for live-line work on high-voltage transmission lines. Specifically, the insulated boom needs to be equipped with a hydraulic pressure reduction system to prevent the formation of a vacuum that could reduce the dielectric strength of the wiring inside the insulated boom and cause electrical breakdown. Summary of the Invention

[0007] To overcome the above technical defects, this application provides a hydraulic control system and control method for an insulated aerial work platform. All actions of the outrigger system and the boom system are controlled by an electro-hydraulic speed proportional intelligent control system, which has good control performance, is not prone to overheating or oil leakage, and has high reliability. The platform integrated control valve group occupies less platform load, has fewer internal pipelines in the insulated boom, has a simple layout of insulated pipeline devices, and can also achieve continuous power supply to the platform for a long time.

[0008] This application provides a hydraulic control system for an insulated aerial work platform, comprising:

[0009] The disembarkation control subsystem, the boarding control subsystem, the platform control subsystem, and the insulation piping system;

[0010] The alighting control subsystem includes a hydraulic pump group, an alighting control valve group, and an integrated return valve block. The alighting control valve group is connected to a horizontal cylinder and a vertical cylinder through an oil circuit.

[0011] The upper vehicle control subsystem includes an upper vehicle control valve group and a slewing mechanism motor, a first boom luffing cylinder, a first boom telescopic cylinder, a second boom luffing cylinder, and a second boom telescopic cylinder connected to the upper vehicle control valve group via an oil circuit.

[0012] The platform control subsystem includes a platform control valve group and a generator motor, winch motor, boom luffing cylinder, platform slewing cylinder and platform leveling cylinder connected to the platform control valve group by an oil circuit.

[0013] The insulating pipeline device includes an insulating arm, a pressurized oil pipeline, a return oil pipeline, and an insulating hose connected to the pressurized oil pipeline and the return oil pipeline.

[0014] The hydraulic pump assembly includes a first hydraulic pump and a second hydraulic pump. The inlets of both the first and second hydraulic pumps are connected to the oil tank. The outlet of the first hydraulic pump is connected to the inlet of the upper control valve assembly and the control oil circuits of the lower horizontal and vertical cylinders via the lower control valve assembly. The return ports of both the upper and lower control valve assemblies are connected to the return oil integrated valve block. The outlet of the second hydraulic pump is connected to the pressure oil pipeline, and the outlet of this pressure oil pipeline is connected to the inlet of the platform control valve assembly. The inlet of the return oil pipeline is connected to the return port of the platform control valve assembly, and the outlet of the return oil pipeline is connected to the oil tank via the return oil integrated valve block.

[0015] Preferably, in this application, the first hydraulic pump is a large hydraulic pump, and the second hydraulic pump is a small hydraulic pump; the lowering control valve group includes an electro-hydraulic directional valve group, a left outrigger control valve group, and a right outrigger control valve group; the uppering control valve group is a turntable boom control valve group; the outlet of the large hydraulic pump is connected to the inlet of the electro-hydraulic directional valve group through a large pump filter, and the return port of the electro-hydraulic directional valve group is connected to the return oil integrated valve block and the oil tank; the first working oil port of the electro-hydraulic directional valve group is connected to the inlet of the turntable boom control valve group, and the return oil port of the turntable boom control valve group is connected to the return oil integrated valve block; the electro-hydraulic directional valve group... The second working oil port is simultaneously connected to the oil inlet of the left outrigger control valve group and the oil inlet of the right outrigger control valve group, and the return oil of the left outrigger control valve group and the return oil of the right outrigger control valve group are both connected to the return oil integrated valve block; the outlet of the hydraulic mini pump is connected to the pressure oil pipeline through the mini pump filter, and the pressure oil pipeline is equipped with an inlet pipeline check valve. The outlet of the pressure oil pipeline is connected to the oil inlet of the platform control valve group. The inlet of the return oil pipeline is connected to the platform control valve group, and the outlet of the return oil pipeline is connected to the undercarriage return oil integrated valve block through the return oil pipeline check valve and the check valve. The undercarriage return oil integrated valve block is connected to the oil tank through the return oil filter.

[0016] As a preferred embodiment of this application, the electro-hydraulic directional valve assembly includes a valve block, a main relief valve for the large pump, a hydraulically controlled directional valve, and a pilot-operated hydraulically controlled directional valve. Both ends of the pilot-operated hydraulically controlled directional valve are equipped with emergency operation positioning knobs. The oil inlet of the hydraulically controlled directional valve is connected to the outlet of the hydraulic large pump. The first working oil port of the hydraulically controlled directional valve is connected to the oil inlet of the turntable boom control valve assembly. The second working oil port of the hydraulically controlled directional valve is connected to the oil inlets of the left outrigger control valve assembly and the right outrigger control valve assembly. The oil port of the pilot-operated hydraulically controlled directional valve is connected to the control oil port of the hydraulically controlled directional valve.

[0017] As a preferred embodiment of this application, the hydraulic pump is a load-sensitive variable pump, with its load-sensitive Ls port connected to a first shuttle valve. One end of the first shuttle valve's working port is connected to the load-sensitive port of the turntable boom control valve group, and the other end of the first shuttle valve's working port is connected to a second shuttle valve. One end of the second shuttle valve's working port is connected to the load-sensitive port of the left outrigger control valve group, and the other end of the second shuttle valve's working port is connected to the load-sensitive port of the right outrigger control valve group.

[0018] As a preferred embodiment of this application, the left outrigger control valve group includes a left front horizontal leg control valve, a left rear horizontal leg control valve, a left front vertical leg control valve, and a left rear vertical leg control valve; the right outrigger control valve group includes a right front horizontal leg control valve, a right rear horizontal leg control valve, a right front vertical leg control valve, and a right rear vertical leg control valve; the left front horizontal leg control valve, the left rear horizontal leg control valve, the right front horizontal leg control valve, and the right rear horizontal leg control valve are all O-type center-position functional solenoid directional valves, and their two working ports are directly connected to the rodless chamber and the rod chamber of the horizontal cylinder, respectively; the left front vertical leg control valve, the left rear vertical leg control valve, the right front vertical leg control valve, and the right rear vertical leg control valve are all Y-type center-position functional solenoid directional valves, and their two working ports are connected to the rodless chamber and the rod chamber of the vertical cylinder, respectively, through a bidirectional hydraulic lock.

[0019] As a preferred embodiment of this application, the outlet of the hydraulic mini-pump is also connected to the inlet of the mini-pump undercarriage relief valve; the outlet of the mini-pump undercarriage relief valve is connected to the return oil integrated valve block.

[0020] Preferably, the turntable boom control valve assembly is a four-way load-sensitive electro-hydraulic proportional multi-way valve, including a first-way turntable slewing control valve, a second-way boom luffing control valve, a third-way boom telescopic control valve, and a fourth-way boom luffing and telescopic control valve. The two working ports of the turntable slewing control valve are respectively connected to the two working ports of the slewing mechanism motor. The two working ports of the boom luffing control valve are respectively connected to the rodless chamber and the rod chamber of the boom luffing cylinder via a boom luffing balance valve. The first working port of the boom telescopic control valve is connected to the first working port of the boom quick-extension electro-hydraulic control valve, and the second working port of the boom telescopic control valve is connected to the boom telescopic balance valve via a boom telescopic balance valve. The rodless chamber of the first-arm telescopic cylinder is connected to the second working port of the first-arm quick-extension solenoid valve; the inlet of the first-arm quick-extension solenoid valve is connected to the rod chamber of the first-arm telescopic cylinder through the first-arm telescopic balance valve; the first and second working ports of the second-arm luffing telescopic control valve are respectively connected to the first and second inlets of the second-arm luffing telescopic switching valve; the first and fourth working ports of the second-arm luffing telescopic switching valve are respectively connected to the rod chamber and rodless chamber of the second-arm luffing cylinder through the second-arm luffing balance valve; the second and third working ports of the second-arm luffing telescopic switching valve are respectively connected to the rodless chamber and rod chamber of the second-arm telescopic cylinder through the second-arm luffing balance valve.

[0021] As a preferred embodiment of this application, the pressure oil pipeline of the insulating pipeline device is connected to the outlet of the hydraulic pump via an inlet oil pipeline check valve at the insulating arm end away from the platform, and to the oil inlet of the platform control valve group at the insulating arm end closer to the platform, and is also connected to an atmospheric check valve; the return oil pipeline is connected to the return oil integrated valve block via a return oil pipeline check valve and a one-way valve at the insulating arm end away from the platform, and to the return oil port of the platform control valve group at the insulating arm end closer to the platform, and is also connected to an atmospheric check valve; both ends of the two insulating hoses are connected to the pressure oil pipeline and the return oil pipeline respectively via quick-connect couplings.

[0022] As a preferred embodiment of this application, the platform control valve group includes a generator flow control valve, a generator system relief valve, a platform system relief valve, a hook lifting control valve, a boom luffing control valve, a platform slewing control valve, a platform leveling control valve, and a tool unloading switching valve; the oil inlet of the generator flow control valve is connected to the oil inlet of the platform control valve group, its priority port is simultaneously connected to the inlet of the generator motor and the oil inlet of the generator system relief valve, and its bypass port is connected to the oil inlets of the platform system relief valve, the hook lifting control valve, the boom luffing control valve, the platform slewing control valve, the platform leveling control valve, and the tool unloading switching valve; The two working ports of the hook lifting control valve are respectively connected to the two working ports of the winch motor; the two working ports of the boom luffing control valve are respectively connected to the rodless chamber and the rod chamber of the boom luffing cylinder through the boom balance valve; the two working ports of the platform slewing control valve are respectively connected to the two working ports of the platform slewing cylinder through the platform slewing balance valve; the two working ports of the platform leveling control valve are respectively connected to the rodless chamber and the rod chamber of the platform leveling cylinder through the leveling balance valve; the first working port of the tool unloading switching valve is blocked, and the second working port is connected to the quick-change connector of the hydraulic tool pressure interface; the quick-change connector of the hydraulic tool return port is connected to the return port of the platform control valve group.

[0023] This application also provides a hydraulic control method for an insulated aerial work platform, comprising the following steps:

[0024] When the vehicle is not in operation, the pilot electric control directional valve of the electro-hydraulic directional valve group is de-energized and in the neutral position, the hydraulic control directional valve is in the neutral position, and the load-sensitive ports of the left outrigger control valve group, right outrigger control valve group, and turntable boom control valve group of the lower vehicle have no pressure feedback to the load-sensitive valve of the hydraulic pump. The hydraulic pump is in a low-pressure standby state; the pressure oil of the hydraulic pump returns to the neutral position through the tool unloading switching valve of the platform control valve group for unloading.

[0025] When the upper boom needs to be operated, check whether the four vertical outriggers of the lower boom are in place. If the outriggers are not in place, the outrigger detection switch will not give a signal, the pilot electric directional valve of the electro-hydraulic directional valve group will not switch, the hydraulic directional valve will not operate, the hydraulic pump pressure oil cannot enter the turntable boom control valve group, and the boom operation will be prohibited. If all the outriggers are in place, the outrigger detection switch will give a signal, the pilot electric directional valve will be energized and switch, the hydraulic directional valve will switch, the hydraulic pump pressure oil will flow to the turntable boom control valve group, and the operation of the upper boom will be allowed.

[0026] When it is necessary to operate the outriggers, the system checks whether the upper boom has left the boom support. If the boom has not left the boom support, the boom support detection switch is triggered, the pilot electric directional valve of the electro-hydraulic directional valve group is energized and reverses, the hydraulic directional valve reverses, and the hydraulic pump pressure oil enters the left and right outrigger control valve groups, allowing outrigger operation. If the boom has left the boom support, the boom support detection switch has no signal, the pilot electric directional valve does not reverse, the hydraulic directional valve does not operate, the hydraulic pump pressure oil cannot enter the left and right outrigger control valve groups, and outrigger operation is prohibited.

[0027] The one-arm quick extension control is achieved by energizing and reversing the one-arm quick extension solenoid valve. Operating the one-arm extension control valve allows oil to enter the rodless chamber of the one-arm extension cylinder, and the oil in the rod chamber enters the rodless chamber through the one-arm quick extension solenoid valve, forming a differential quick extension circuit. During compound actions, the one-arm quick extension solenoid valve is automatically energized through program control to achieve rapid extension of the one arm under high flow requirements.

[0028] The platform is powered by hydraulic pump pressure oil supplied to the generator motor at a fixed flow rate through the generator flow control valve of the platform control valve group. This drives the generator to operate, powering the platform load and charging the battery. The remaining oil is supplied from the bypass port for platform leveling, rotation, and hook lifting and lowering operations.

[0029] Pressure control of the insulating pipeline is achieved by installing an oil inlet check valve in the oil inlet pipeline of the insulating arm and an atmospheric check valve near the platform end, and an oil return check valve in the oil return pipeline and an atmospheric check valve near the platform end, to prevent oil backflow and the formation of a vacuum in the pipeline, thereby maintaining dielectric strength.

[0030] The platform automatically levels itself by detecting the platform tilt angle through a leveling tilt angle sensor. When the tilt angle exceeds the set value, the tool unloading switching valve is energized to stop the bypass oil circuit from unloading. At the same time, the corresponding valve head of the leveling control valve is energized, driving the platform leveling cylinder to move and achieve automatic leveling.

[0031] Emergency retraction is achieved by setting up emergency operation knobs with positioning at both ends of the pilot electric control directional valve of the electro-hydraulic directional valve group. In the event of an electrical control failure, the corresponding knob is manually turned in to switch the hydraulic control directional valve, allowing pressurized oil to enter the turntable boom control valve group or the left outrigger control valve group and the right outrigger control valve group. The emergency retraction of the boom or outrigger is then achieved by manually operating the hydraulic handle.

[0032] The advantages of this application compared to existing technologies are:

[0033] 1. Safety protection control with automatic interlock between outriggers and boom: This application achieves automatic interlock control between outriggers and boom through a combination of electro-hydraulic directional valve assembly and pilot-operated directional valve, along with logic control of the electronically controlled detection switch. When the outriggers are not in position, operation of the upper boom is prohibited; when the boom leaves the boom support, operation of the lower outriggers is prohibited, effectively preventing dangerous accidents such as rollovers caused by misoperation.

[0034] 2. The boom can be extended quickly without throttle: This application sets up a boom quick extension electronic control valve to form a differential quick extension connection circuit. Without increasing the system flow, it realizes the automatic acceleration of the extension speed of the boom telescopic cylinder, thereby driving the boom to extend quickly and improving the work efficiency.

[0035] 3. The platform's electro-hydraulic automatic leveling provides rapid response and excellent automatic leveling effect: The leveling system of this application shares a power source with the generator direct supply system, ensuring that the leveling system always has oil pressure; in addition, a two-way balance valve with a large pilot ratio and a spring cavity open to the atmosphere is used as the platform leveling valve. The platform tilt angle is detected by a leveling tilt angle sensor, and when it exceeds the set value, the platform leveling cylinder is automatically driven to actuate, achieving rapid response and excellent leveling effect.

[0036] 4. The platform is equipped with a generator charging direct supply control system, which enables intelligent electronic control of boom / platform movements at the insulated aerial work platform: This application provides stable pressure oil to the platform control subsystem through a small hydraulic pump, and sets up a generator flow control valve to prioritize supplying a fixed flow to the generator motor, driving the generator to operate, powering the platform load and charging the battery, thus realizing intelligent electronic control operation.

[0037] 5. The insulating arm is equipped with a hydraulic pressure reduction pipeline device, which can effectively prevent the dielectric strength of the circuit inside the insulating arm from decreasing and causing electrical breakdown, greatly improving the safety of personnel working with live wires: This application sets an oil inlet check valve, an oil return check valve, and an atmospheric check valve on the oil inlet pipeline and the oil return pipeline of the insulating arm, respectively, to prevent oil backflow and the formation of a vacuum in the pipeline, maintain dielectric strength, and ensure operational safety.

[0038] 6. In the event of an electrical control failure, the vehicle boom and outriggers can be effectively and quickly retracted to safely lower the personnel on the platform back to the ground: This application provides emergency operation knobs with positioning at both ends of the pilot electric control directional valve of the electro-hydraulic directional valve group. The turntable control valve group and the lowering control valve group are equipped with emergency handles. In the event of an electrical control failure, the boom or outriggers can be manually retracted to ensure equipment safety. Attached Figure Description

[0039] Figure 1 A schematic diagram of the hydraulic control system structure of an insulated aerial work platform according to the present invention;

[0040] Figure 2 This invention provides a simplified external structural diagram and a schematic diagram showing the positions of some components on the upper structure of an insulated aerial work platform.

[0041] Figure 3 A schematic diagram of the control element arrangement of the hydraulic control system platform for an insulated aerial work vehicle according to the present invention;

[0042] Figure 4 Enlarged view of the structure of the control valve group components of this invention platform;

[0043] In the diagram: 1. Large hydraulic pump; 2. Small hydraulic pump; 3. Large pump filter; 4. Small pump filter; 5.1. First shuttle valve; 5.2. Second shuttle valve; 6. Horizontal cylinder; 7. Vertical cylinder; 8. Two-way hydraulic lock; 9. Rotary mechanism motor; 10. First boom luffing balance valve; 11. First boom luffing cylinder; 12. First boom quick extension solenoid valve; 13. First boom telescopic balance valve; 14. First boom telescopic cylinder; 15. Second boom luffing telescopic switching valve; 16. Second boom luffing balance valve; 17. Second boom luffing cylinder; 18. Second boom telescopic balance valve; 19. Second boom telescopic cylinder. 20. Inlet oil line check valve; 21. Return oil line check valve; 22. Insulating boom; 23. Insulating hose; 24. Quick-connect coupling; 25. Atmospheric check valve; 26. Generator motor; 27. Winch motor; 28. Boom luffing cylinder; 29. ​​Boom balance valve; 30. Platform slewing balance valve; 31. Platform slewing cylinder; 32. Platform leveling cylinder; 33. Leveling balance valve; 34. Hydraulic tool pressure interface quick-connect coupling; 35. Hydraulic tool return oil port quick-connect coupling; 36. Small pump undercarriage relief valve; 37. Check valve; 38. Return oil integrated valve block; 39. Return oil filter; 40. Electro-hydraulic directional valve assembly; 401. Valve block; 402. Main relief valve; 403. Hydraulic directional valve; 404. Pilot-operated directional valve; 50. Left outrigger control valve assembly; 501. Left front horizontal leg control valve; 502. Left rear horizontal leg control valve; 503. Left front vertical leg control valve; 504. Left rear vertical leg control valve; 60. Right outrigger control valve assembly; 601. Right front horizontal leg control valve; 602. Right rear horizontal leg control valve; 603. Right front vertical leg control valve; 604. Right rear vertical leg control valve; 70. Turntable boom control valve assembly; 701, Turntable slewing control valve; 702, First boom luffing control valve; 703, First boom telescopic control valve; 704, Second boom luffing / telescopic control valve; 80, Platform control valve assembly; 801, Generator control flow valve; 802, Generator system overflow valve; 803, Platform system overflow valve; 804, Hook lifting control valve; 805, Boom luffing control valve; 806, Platform slewing control valve; 807, Platform leveling control valve; 808, Tool unloading switching valve; 90, Generator; 91, Leveling tilt sensor. Detailed Implementation

[0044] To facilitate understanding of the present invention, a more complete description will be given below with reference to the accompanying drawings. Preferred embodiments of the invention are shown in the drawings. However, the invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of the invention.

[0045] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0046] When describing positional relationships, unless otherwise specified, when an element is referred to as being "on" another element, it may be directly on the other element or there may be intermediate elements. It is also understood that when an element is referred to as being "between" two elements, it may be the only one between the two elements, or there may be one or more intermediate elements.

[0047] When using the terms “including,” “having,” and “comprising” as described herein, another component may be added unless explicitly qualifying terms such as “only,” “consisting of,” etc. are used. Unless otherwise stated, singular terms may include plural forms and should not be construed as having a quantity of one.

[0048] It should also be understood that, in interpreting an element, although not explicitly described, the element is interpreted as including a range of error, which should be within the acceptable deviation range of a particular value as determined by a person skilled in the art. For example, "approximately," "about," or "substantially" can mean within one or more standard deviations, without limitation herein.

[0049] As attached Figure 1 - Appendix Figure 4 As shown, this application provides a hydraulic control system for an insulated aerial work platform, comprising:

[0050] The disembarkation control subsystem, the boarding control subsystem, the platform control subsystem, and the insulation piping system;

[0051] The alighting control subsystem includes a hydraulic pump group, an alighting control valve group, and a return oil integrated valve block 38. The alighting control valve group is connected to a horizontal oil cylinder 6 and a vertical oil cylinder 7 through an oil circuit.

[0052] The upper vehicle control subsystem includes an upper vehicle control valve group and a slewing mechanism motor 9, a first boom luffing cylinder 11, a first boom telescopic cylinder 14, a second boom luffing cylinder 17, and a second boom telescopic cylinder 19 connected to the upper vehicle control valve group by an oil circuit.

[0053] The platform control subsystem includes a platform control valve group 80 and a generator motor 26, a winch motor 27, a boom luffing cylinder 28, a platform slewing cylinder 31, and a platform leveling cylinder 32 connected to the platform control valve group 80 by an oil circuit.

[0054] The insulating pipeline device includes an insulating arm 22, a pressurized oil pipeline, a return oil pipeline, and an insulating hose 23 connected to the pressurized oil pipeline and the return oil pipeline;

[0055] The hydraulic pump assembly includes a first hydraulic pump and a second hydraulic pump. The inlets of both the first and second hydraulic pumps are connected to the oil tank. The outlet of the first hydraulic pump is connected to the inlet of the upper control valve assembly and the control oil circuits of the lower horizontal cylinder 6 and the vertical cylinder 7 via the lower control valve assembly. The return ports of the upper and lower control valve assemblies are both connected to the return oil integrated valve block 38. The outlet of the second hydraulic pump is connected to the pressure oil pipeline, and the outlet of the pressure oil pipeline is connected to the inlet of the platform control valve assembly 80. The inlet of the return oil pipeline is connected to the return port of the platform control valve assembly 80, and the outlet of the return oil pipeline is connected to the oil tank via the return oil integrated valve block 38.

[0056] In one embodiment, the first hydraulic pump is a large hydraulic pump 1, which has a large flow and pressure output capacity, capable of meeting the power requirements for the upper boom and lower outrigger movements. The second hydraulic pump is a small hydraulic pump 2, mainly used to provide stable pressure oil to the platform control subsystem, ensuring the normal operation of various equipment within the platform. The lower outrigger control valve group includes an electro-hydraulic directional valve group 40, a left outrigger control valve group 50, and a right outrigger control valve group 60. The electro-hydraulic directional valve group 40, as the core control element, receives electrical control signals to switch the oil circuit, thereby controlling the flow of hydraulic oil and achieving precise control of the upper and lower outrigger movements. The left outrigger control valve group 50 and the right outrigger control valve group 60 respectively control the horizontal extension and retraction and vertical lifting movements of the left and right outriggers. Through reasonable valve group design and oil circuit connection, the smoothness and reliability of the outrigger movements are ensured. The upper control valve group is the turntable boom control valve group 70, which integrates multiple control valves for controlling the boom's rotation, luffing, and telescopic movements. Through precise flow and pressure control, it achieves high-precision boom operation. The outlet of the hydraulic pump 1 is connected to the inlet of the electro-hydraulic directional valve group 40 via a pump filter 3. The pump filter 3 effectively filters impurities in the hydraulic oil, preventing them from entering the valve group and hydraulic components, thus extending the equipment's service life. The return port of the electro-hydraulic directional valve group 40 is connected to the return oil integrated valve block 38 and the oil tank, ensuring smooth oil return and preventing excessive system pressure. The first working port of the electro-hydraulic directional valve group 40 is connected to the inlet of the turntable boom control valve group 70, and the return port of the turntable boom control valve group 70 is connected to the return oil integrated valve block 38, realizing the hydraulic oil circulation for the upper boom's movement. The second working port of the electro-hydraulic directional valve assembly 40 is simultaneously connected to the inlet ports of the left outrigger control valve assembly 50 and the right outrigger control valve assembly 60. The return oil from both the left and right outrigger control valve assemblies 50 and 60 is connected to the return oil integrated valve block 38, completing the hydraulic oil circulation for the outrigger movement. The outlet of the hydraulic mini-pump 2 is connected to the pressure oil pipeline via a mini-pump filter 4, and the pressure oil pipeline is equipped with an inlet check valve 20. The mini-pump filter 4 ensures the cleanliness of the hydraulic oil entering the platform control subsystem, and the inlet check valve 20 prevents oil backflow, ensuring a stable oil supply to the platform control subsystem. The outlet of the hydraulic oil pipeline is connected to the inlet of the platform control valve group 80. The inlet of the return oil pipeline is connected to the platform control valve group 80, and the outlet of the return oil pipeline is connected to the undercarriage return oil integrated valve block 38 through the return oil pipeline check valve 21 and the one-way valve 37. The undercarriage return oil integrated valve block 38 is connected to the oil tank through the return oil filter 39, forming a complete platform hydraulic oil circulation loop. At the same time, the return oil filter 39 filters the return oil again to ensure the cleanliness of the hydraulic oil in the oil tank.

[0057] In one embodiment, the electro-hydraulic directional valve assembly 40 includes a valve block 401, a main pump relief valve 402, a hydraulically controlled directional valve 403, and a pilot-operated hydraulically controlled directional valve 404. The valve block 401 serves as the mounting base for each component, providing a reasonable oil passage to ensure smooth hydraulic oil flow between components. The main pump relief valve 402 provides safety protection; when the system pressure exceeds a set value, the relief valve opens, overflowing excess hydraulic oil back to the oil tank to prevent damage to the equipment due to excessive system pressure. The hydraulically controlled directional valve 403 is a key component for switching oil circuits. Its inlet is connected to the outlet of the hydraulic main pump 1, its first working port is connected to the inlet of the turntable boom control valve assembly 70, and its second working port is connected to the inlets of the left outrigger control valve assembly 50 and the right outrigger control valve assembly 60. By controlling the valve core position of the hydraulically controlled directional valve 403, the direction of hydraulic oil flow is changed. Both ends of the pilot-operated directional valve 404 are equipped with emergency operation positioning knobs. During normal electrical control operation, the pilot-operated directional valve 404 switches according to the received electrical control signal, controlling the action of the hydraulic directional valve 403. When the electrical control system malfunctions, the pilot-operated directional valve 404 can be switched manually by rotating the emergency operation positioning knob, thereby achieving manual control of the hydraulic directional valve 403. This ensures that the boom and outriggers can be retracted in emergencies, guaranteeing equipment safety. The oil port of the pilot-operated directional valve 404 is connected to the control oil port of the hydraulic directional valve 403. The valve core movement of the hydraulic directional valve 403 is controlled through the pilot oil circuit, achieving remote control and precise operation.

[0058] In one embodiment, the hydraulic pump 1 is a load-sensitive variable pump, which can automatically adjust its output flow and pressure according to the system's load requirements, achieving energy saving and efficient operation. Its load-sensitive Ls port is connected to a first shuttle valve 5.1. One end of the first shuttle valve 5.1 is connected to the load-sensitive port of the turntable boom control valve group 70, and the other end is connected to a second shuttle valve 5.2. One end of the second shuttle valve 5.2 is connected to the load-sensitive port of the left outrigger control valve group 50, and the other end is connected to the load-sensitive port of the right outrigger control valve group 60. Through this shuttle valve connection method, the load-sensitive variable pump can sense the load changes of the upper boom and lower outriggers in real time and adjust the output flow and pressure according to the maximum load requirements, ensuring stable operation of the system under different working conditions while avoiding energy waste. For example, when the upper boom is performing heavy-load operations, the load-sensitive variable pump will automatically increase the output flow and pressure to meet the boom's operational needs; while when the lower outriggers are performing extension and retraction operations, if the load is small, the pump will correspondingly reduce the output flow and pressure to reduce energy consumption.

[0059] In one embodiment, the left outrigger control valve group 50 includes a left front horizontal leg control valve 501, a left rear horizontal leg control valve 502, a left front vertical leg control valve 503, and a left rear vertical leg control valve 504; the right outrigger control valve group 60 includes a right front horizontal leg control valve 601, a right rear horizontal leg control valve 602, a right front vertical leg control valve 603, and a right rear vertical leg control valve 604. Each control valve controls the horizontal extension and vertical lifting / lowering movements of its corresponding outrigger. Precise valve core position control ensures smooth and accurate outrigger movement. The left front horizontal leg control valve 501, left rear horizontal leg control valve 502, right front horizontal leg control valve 601, and right rear horizontal leg control valve 602 are all O-type center-position functional solenoid directional valves, with their two working ports directly connected to the rodless chamber and the rod chamber of the horizontal cylinder 6, respectively. When the O-type neutral-position solenoid directional valve is in the neutral position, it can cut off the oil inlet and outlet of the hydraulic cylinder, keeping the horizontal hydraulic cylinder 6 stationary and preventing the outriggers from moving on their own when not in operation, thus improving the safety of the equipment. The left front vertical leg control valve 503, left rear vertical leg control valve 504, right front vertical leg control valve 603, and right rear vertical leg control valve 604 are all Y-type neutral-position solenoid directional valves. Their two working ports are connected to the rodless chamber and rod chamber of the vertical hydraulic cylinder 7 respectively through a bidirectional hydraulic lock 8. When the Y-type neutral-position solenoid directional valve is in the neutral position, it can connect the two chamber hydraulic lock inlets of the vertical hydraulic cylinder 7 to the oil tank, enabling rapid closure of the hydraulic lock. The bidirectional hydraulic lock 8 can lock the position of the vertical hydraulic cylinder 7 after the outriggers are adjusted to the correct position, preventing the outriggers from moving due to external forces and ensuring the stability of the entire vehicle.

[0060] In one embodiment, the outlet of the hydraulic mini-pump 2 is also connected to the inlet of the mini-pump undercarriage relief valve 36; the outlet of the mini-pump undercarriage relief valve 36 is connected to the return oil integrated valve block 38. The mini-pump undercarriage relief valve 36 serves a safety protection function. When the output pressure of the hydraulic mini-pump 2 exceeds the set value, the relief valve opens, allowing excess hydraulic oil to overflow back to the oil tank, preventing damage to components in the platform control subsystem due to excessive pressure and ensuring the normal operation of the platform equipment. Simultaneously, by reasonably setting the overflow pressure of the relief valve, the system can be guaranteed to operate stably within the normal operating pressure range, improving the reliability and safety of the system.

[0061] In one embodiment, the turntable boom control valve group 70 is a four-way load-sensitive electro-hydraulic proportional multi-way valve, including a first-way turntable slewing control valve 701, a second-way boom luffing control valve 702, a third-way boom telescopic control valve 703, and a fourth-way boom luffing telescopic control valve 704. The two working ports of the turntable slewing control valve 701 are respectively connected to the two working ports of the slewing mechanism motor 9. The two working ports of the boom luffing control valve 702 are respectively connected to the rodless chamber and the rod chamber of the boom luffing cylinder 11 via the boom luffing balance valve 10. The first working port of the boom telescopic control valve 703 is connected to the first working port of the boom quick-extension electro-hydraulic control valve 12, and the second working port of the boom telescopic control valve 703 is connected to the boom telescopic balance valve 12. Valve 13 is connected to the rodless chamber of the first arm telescopic cylinder 14 and to the second working port of the first arm quick extension solenoid valve 12; the oil inlet of the first arm quick extension solenoid valve 12 is connected to the rod chamber of the first arm telescopic cylinder 14 through the first arm telescopic balance valve 13; the first and second working ports of the second arm luffing telescopic control valve 704 are respectively connected to the first and second inlets of the second arm luffing telescopic switching valve 15; the first and fourth working ports of the second arm luffing telescopic switching valve 15 are respectively connected to the rod chamber and rodless chamber of the second arm luffing cylinder 17 through the second arm luffing balance valve 16; the second and third working ports of the second arm luffing telescopic switching valve 15 are respectively connected to the rodless chamber and rod chamber of the second arm telescopic cylinder 19 through the second arm telescopic balance valve 18.

[0062] When the slewing control valve 701 of the turntable is reversed, oil enters the first working chamber of the slewing mechanism motor 9, and the turntable rotates clockwise to drive the entire boom to rotate clockwise. When the second working chamber of the turntable is in turn, the turntable reverses to drive the entire boom to rotate counterclockwise. When the luffing control valve 702 of the boom is reversed, oil enters the rodless chamber of the boom luffing cylinder 11 to drive the boom to rise, and oil enters the rod chamber to drive the boom to fall.

[0063] Furthermore, when the one-arm quick-extension solenoid valve 12 is de-energized, the one-arm extension control valve 703 is switched, causing oil to enter the rodless chamber of the one-arm extension cylinder 14 to drive the one-arm to extend outward, and oil to enter the rod chamber to drive the one-arm to retract. Further, when the one-arm quick-extension solenoid valve 12 is energized and switched, the one-arm extension control valve 703 is switched, causing oil to enter the rodless chamber of the one-arm extension cylinder 14 to drive the one-arm to extend outward. At this time, the oil in the rod chamber of the one-arm extension cylinder 14 enters the rodless chamber of the one-arm extension cylinder 14 again through the one-arm quick-extension solenoid valve 12. Due to the area difference between the rodless and rod chambers of the one-arm extension cylinder 14, a differential connection circuit is formed. Without increasing the system flow rate, i.e., without needing to increase the chassis power throttle, the extension speed of the one-arm extension cylinder is automatically accelerated, thereby driving the boom to extend rapidly. When the one-arm extension cylinder 14 reaches the end of its stroke, the pressure oil from the hydraulic pump 1 flows directly back to the oil tank through the pump overflow valve 402, providing safety protection.

[0064] Furthermore, a two-arm switching valve 15 is provided between the two-arm control valve 704 and the two-arm luffing cylinder 17 and the two-arm telescopic cylinder 19. When the two-arm switching valve 15 is not energized, the two-arm control valve 704 is operated to switch directions, so that the rodless chamber of the two-arm luffing cylinder 17 is filled with oil to drive the two arms to rise, and the rod chamber is filled with oil to drive the two arms to fall. When the two-arm switching valve 15 is energized, the two-arm control valve 704 is operated to switch directions, so that the rodless chamber of the two-arm telescopic cylinder 19 is filled with oil to drive the two arms to extend outward, and the rod chamber is filled with oil to drive the two arms to retract.

[0065] In one embodiment, the pressure oil line of the insulating pipeline device is connected to the outlet of the hydraulic pump 2 via an inlet check valve 20 at the insulating arm 22 furthest from the platform, and to the inlet of the platform control valve group 80 at the insulating arm 22 closest to the platform, and is connected to an atmospheric check valve 25. The inlet check valve 20 is a 5PSi one-way valve, and its function is to prevent the oil in the insulating hose 23 and the inlet hose of the platform control valve group 80 from flowing back due to gravity, ensuring that the platform control subsystem always has a stable supply of pressure oil. The atmospheric check valve 25 is an integrated assembly containing an air filter and a 5PSi one-way valve. When the absolute pressure of the oil in the insulating hose 23 is lower than a certain value (80%) of the ambient atmospheric pressure, the atmospheric check valve 25 opens, allowing atmospheric impurities to be filtered through the air filter in the atmospheric check valve 25 assembly and enter clean air. This prevents the formation of a local vacuum in the oil inlet pipe of the insulating arm 22, which could reduce dielectric strength and easily lead to electrical breakdown, thus avoiding danger to insulated high-altitude workers performing live work. The return oil pipe is connected to the return oil integrated valve block 38 at the end of the insulating arm 22 away from the platform through the return oil pipe check valve 21 and the one-way valve 37, and at the end of the insulating arm 22 closer to the platform, it is connected to the return oil port of the platform control valve group 80 and is connected to the atmospheric check valve 25. The return oil line check valve 21 is a 50PSi back pressure valve. Its back pressure effectively prevents the oil in the insulating hose 23 and the return oil hose of the platform control valve group 80 from flowing back to the oil tank due to gravity, ensuring the normal pressure of the return oil line. Similarly, when the absolute pressure of the oil in the return oil insulating hose 23 is lower than a certain value (80%) of the ambient atmospheric pressure, the atmospheric check valve 25 near the platform end opens, filtering atmospheric impurities through the air filter to prevent the formation of a partial vacuum in the return oil line of the insulating arm 22, maintaining dielectric strength, and ensuring operational safety. Both ends of the two sections of insulating hose 23 are connected to the pressure oil line and the return oil line respectively through quick-connect couplings 24. The quick-connect couplings 24 facilitate the installation and removal of the insulating hose 23, improving the maintenance efficiency of the equipment.

[0066] In one embodiment, the platform control valve group 80 includes a generator flow control valve 801, a generator system relief valve 802, a platform system relief valve 803, a hook lifting control valve 804, a boom luffing control valve 805, a platform slewing control valve 806, a platform leveling control valve 807, and a tool unloading switching valve 808. The inlet of the generator flow control valve 801 is connected to the inlet of the platform control valve group 80, its priority port is simultaneously connected to the inlet of the generator motor 26 and the inlet of the generator system relief valve 802, and its bypass port is connected to the inlets of the platform system relief valve 803, the hook lifting control valve 804, the boom luffing control valve 805, the platform slewing control valve 806, the platform leveling control valve 807, and the tool unloading switching valve 808. The inlet of the 8 is connected; the two working ports of the hook lifting control valve 804 are respectively connected to the two working ports of the winch motor 27; the two working ports of the boom luffing control valve 805 are respectively connected to the rodless chamber and the rod chamber of the boom luffing cylinder 28 through the boom balance valve 29; the two working ports of the platform slewing control valve 806 are respectively connected to the two working ports of the platform slewing cylinder 31 through the platform slewing balance valve 30; the two working ports of the platform leveling control valve 807 are respectively connected to the rodless chamber and the rod chamber of the platform leveling cylinder 32 through the leveling balance valve 33; the first working port of the tool unloading switching valve 808 is blocked, and the second working port is connected to the hydraulic tool pressure interface quick-change connector 34; the hydraulic tool return port quick-change connector 35 is connected to the return port of the platform control valve group 80.

[0067] Furthermore, the return ports of the generator system overflow valve 802, the platform system overflow valve 803, the hook motor control valve 804, the boom luffing control valve 805, the platform slewing control valve 806, the platform leveling control valve 807, and the tool unloading switching valve 808 are all connected to the return port of the platform control valve group 80 through the internal oil passages of the valve block. Preferably, the platform leveling valve 807 is a bidirectional balance valve 33 with a large pilot ratio and a spring chamber open to the atmosphere, enabling rapid response and good automatic leveling effect. Further, the generator flow control valve 801 is a pressure-compensated priority fixed flow valve, the platform leveling control valve 807 is an O-function proportional directional valve with an emergency operation knob, the tool unloading control valve 808 is an H-type solenoid directional valve with a positioning emergency operation knob, the platform slewing control valve 806 and the boom luffing control valve 805 are both O-function solenoid directional valves, and the lifting and lowering control valve 804 is a Y-function solenoid directional valve. Preferably, the tool unloading control valve 808 is an H-type solenoid directional valve, serving as both a hydraulic tool interface control valve and a platform subsystem unloading valve, achieving multiple functions and reducing the space and weight occupied by the valve assembly on the platform.

[0068] This application provides a hydraulic control method for an insulated aerial work platform, comprising the following steps:

[0069] When the vehicle is not in operation, the pilot electric control directional valve 404 of the electro-hydraulic directional valve group 40 is de-energized and in the neutral position, the hydraulic control directional valve 403 is in the neutral position, and the load-sensitive ports of the left outrigger control valve group 50, the right outrigger control valve group 60, and the turntable boom control valve group 70 do not provide pressure feedback to the load-sensitive valve of the hydraulic pump 1. The hydraulic pump 1 is in a low-pressure standby state; the pressure oil of the hydraulic pump 2 returns to the neutral position through the tool unloading switching valve 808 of the platform control valve group 80 for unloading.

[0070] When the upper boom needs to be operated, the four vertical outriggers of the lower boom are checked to see if they are in place. If the outriggers are not in place, the outrigger detection switch has no signal, the pilot electric directional valve 404 of the electro-hydraulic directional valve group 40 does not switch, the hydraulic directional valve 403 does not operate, the hydraulic pump 1 cannot enter the turntable boom control valve group 70, and the boom operation is prohibited, that is, the upper boom cannot be operated. If all the outriggers are in place, the outrigger detection switch sends a signal, the pilot electric directional valve 404 receives the outrigger position detection signal a, the valve head is energized and switches, then the hydraulic directional valve 403 switches, the hydraulic pump 1 pressure oil flows to the turntable boom control valve group 70, and the upper boom can be operated.

[0071] When it is necessary to operate the outriggers, the system checks whether the upper boom has left the boom support. If the boom has not left the boom support, the boom support detection switch is triggered, the pilot electric directional valve 404 of the electro-hydraulic directional valve group 40 is energized and reversed, the hydraulic directional valve 403 reverses, and the hydraulic pump 1 pressurized oil enters the left outrigger control valve group 50 and the right outrigger control valve group 60, allowing the outriggers to operate. If the boom has left the boom support, the boom support detection switch has no signal, the pilot electric directional valve 404 does not reverse, the hydraulic directional valve 403 does not operate, the hydraulic pump 1 pressurized oil cannot enter the left outrigger control valve group 50 and the right outrigger control valve group 60, and the outriggers are prohibited from operating.

[0072] The boom extension control is achieved by energizing and reversing the boom extension solenoid valve 12. When the toggle switch on the control panel is set to the "boom extension" position, the boom extension control valve 703 is operated to allow oil to enter the rodless chamber of the boom extension cylinder 14. Due to the area difference between the rodless chamber and the rod chamber of the boom extension cylinder 14, a differential extension connection circuit is formed. This means that the user can select according to the working conditions. When boom extension is required, the extension speed of the boom extension cylinder is automatically accelerated without increasing the system flow, i.e. without needing to increase the chassis power throttle. This drives the boom to extend quickly.

[0073] The platform is powered by hydraulic pump 2, which supplies pressurized oil to generator motor 26 at a fixed flow rate through generator flow control valve 801 of platform control valve group 80. This drives generator 90 to operate, providing power to the platform load and charging the battery. The remaining oil is supplied from the bypass port for platform leveling, rotation, and hook lifting and lowering operations.

[0074] The pressure control of the insulating pipeline is achieved by setting an oil inlet check valve 20 in the oil inlet pipeline of the insulating arm 22 and an atmospheric check valve 25 near the platform end, and setting an oil return check valve 21 in the oil return pipeline and an atmospheric check valve 25 near the platform end, to prevent oil backflow and the formation of a vacuum in the pipeline, and to maintain the dielectric strength.

[0075] The platform automatically levels itself by detecting the platform tilt angle through the leveling tilt angle sensor 91. When the tilt angle exceeds the set value, the tool unloading switching valve 808 is energized to stop the bypass oil circuit from unloading. At the same time, the corresponding valve head of the leveling control valve 807 is energized, driving the platform leveling cylinder 32 to achieve automatic leveling. It should be noted that at the lowest oil pump speed, the remaining flow of the hydraulic pump 2 can be guaranteed to be sufficient for the automatic leveling of the platform. Specifically, when the leveling tilt sensor 91 detects that the platform tilt angle exceeds a certain angle (e.g., 0.3° or more), if the angle is positive and corresponds to the platform tilting forward, the tool / unloading switching valve 808b of the platform control valve group 80 is energized, and the bypass oil circuit of the small pump no longer returns to the oil tank for unloading. At the same time, the a valve of the leveling control valve 807 is energized, and the bypass oil circuit of the generator control valve 801 of the platform control valve group 80 enters the rod chamber of the platform leveling cylinder 32, causing it to retract and tilt backward for automatic leveling. Conversely, when the angle detected by the leveling tilt sensor 91 is negative and corresponds to the platform tilting backward, the b valve of the tool unloading switching valve 808 is energized, and the bypass oil circuit of the generator control valve 801 no longer returns to the oil tank for unloading. At the same time, the b valve of the leveling control valve 807 is energized, and the bypass oil circuit of the generator control valve 801 enters the rodless chamber of the platform leveling cylinder 32, causing it to extend outward for automatic leveling. In addition, the hydraulic pump 2 continuously supplies oil to the platform generator 90. The inlet P port and return T port of the platform control valve group 80 are equipped with inlet check valve 20 and return check valve 21 respectively due to the insulated pipeline. The pipeline is always full of oil. The platform control valve group 80 is electrically controlled for unloading. The platform leveling valve 807 is a large pilot ratio atmospheric leveling valve 33. The platform builds up pressure quickly during automatic leveling and the automatic leveling response is rapid.

[0076] Emergency retraction is achieved by using emergency operation knobs with positioning functions at both ends of the pilot-operated directional valve 404 of the electro-hydraulic directional valve assembly 40. In the event of an electrical control failure, the corresponding knob is manually turned in, causing the hydraulic directional valve 403 to switch. Pressure oil then enters the turntable boom control valve assembly 70 or the left outrigger control valve assembly 50 and right outrigger control valve assembly 60. Emergency retraction of the boom or outrigger is then achieved by manually operating the hydraulic handle. Specifically: When an electrical control failure occurs, the vehicle power is turned off. The emergency operation knob with positioning function on the valve head side of the pilot-operated directional valve 404 of the electro-hydraulic directional valve assembly 40 is turned in. The pilot-operated directional valve 404 switches, which in turn switches the hydraulic directional valve 403. Pressure oil from the hydraulic pump 1 enters the upper turntable boom control valve assembly 70. Operating the hydraulic handle of the corresponding action control valve in the turntable boom control valve assembly 70 allows the upper boom to be retracted. After the emergency operation is completed, promptly turn out the emergency operation knob for positioning the valve head of the pilot electric directional valve 404 to restore its original position. When the electronic control system malfunctions, turn off the vehicle's power supply and turn in the emergency operation knob with positioning on the valve head side of the pilot electric directional valve 404 of the electro-hydraulic directional valve assembly 40. The pilot electric directional valve 404 will reverse, causing the hydraulic directional valve 403 to switch polarity. Pressure oil from the hydraulic pump 1 will enter the left outrigger control valve assembly 50 and the right outrigger control valve assembly 60. Operating the hydraulic handles of the control valves in the left and right outrigger control valve assemblies 50 and 60 will retract the horizontal and vertical outriggers. After the emergency operation is completed, promptly turn out the emergency operation knob for positioning the valve head of the pilot electric directional valve 404 to restore its original position.

[0077] The above embodiments are only used to illustrate the technical solutions of the embodiments of this application, and are not intended to limit them. Although the embodiments of this application have been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope defined by the claims of this application.

Claims

1. A hydraulic control system for an insulated aerial work platform, comprising a dismount control subsystem, an mount control subsystem, a platform control subsystem, and an insulated pipeline device; The aisle control subsystem includes a hydraulic pump group, an aisle control valve group and a return oil integrated valve block (38). The aisle control valve group is connected to the horizontal cylinder (6) and the vertical cylinder (7). The upper control subsystem includes the upper control valve group and the slewing mechanism motor (9), the first boom luffing cylinder (11), the first boom telescopic cylinder (14), the second boom luffing cylinder (17), and the second boom telescopic cylinder (19) connected thereto. The platform control subsystem includes a platform control valve group (80) and a generator motor (26), a winch motor (27), a boom luffing cylinder (28), a platform slewing cylinder (31), and a platform leveling cylinder (32) connected thereto. The insulating piping system includes an insulating arm (22), a pressurized oil line, a return oil line, and an insulating hose (23). The hydraulic pump set includes a first hydraulic pump and a second hydraulic pump, both of which have their inlets connected to the oil tank. The outlet of the first hydraulic pump is connected to the inlet of the upper control valve group and the control oil circuits of the horizontal cylinder (6) and the vertical cylinder (7) via the lower control valve group. The return ports of the upper control valve group and the lower control valve group are both connected to the return oil integrated valve block (38). The outlet of the second hydraulic pump is connected to the pressure oil pipeline. The outlet of the pressure oil pipeline is connected to the inlet of the platform control valve group (80). The inlet of the return oil pipeline is connected to the return port of the platform control valve group (80). Its outlet is connected to the oil tank via the return oil integrated valve block (38). The lowering control valve group includes an electro-hydraulic directional valve group (40), a left outrigger control valve group (50), and a right outrigger control valve group (60); the uppering control valve group is a turntable boom control valve group (70). The first working port of the electro-hydraulic directional valve group (40) is connected to the inlet of the turntable boom control valve group (70), and the return port of the turntable boom control valve group (70) is connected to the return oil integrated valve block (38). The second working port of the electro-hydraulic directional valve group (40) is simultaneously connected to the inlet of the left outrigger control valve group (50) and the inlet of the right outrigger control valve group (60). The return oil of the left outrigger control valve group (50) and the return oil of the right outrigger control valve group (60) are both connected to the return oil integrated valve block (38). The electro-hydraulic directional valve assembly (40) includes a valve block (401), a main relief valve (402) of the large pump, a hydraulically controlled directional valve (403), and a pilot-operated hydraulically controlled directional valve (404). The control end of the pilot-operated hydraulically controlled directional valve (404) is electrically connected to the outrigger detection switch and the boom support detection switch, respectively. Both ends of the pilot-operated hydraulically controlled directional valve (404) are equipped with emergency operation positioning knobs. The oil inlet of the hydraulically controlled directional valve (403) is connected to the outlet of the hydraulic large pump (1). The first working oil port of the hydraulically controlled directional valve (403) is connected to the oil inlet of the turntable boom control valve assembly (70). The second working oil port of the hydraulically controlled directional valve (403) is connected to the oil inlets of the left outrigger control valve assembly (50) and the right outrigger control valve assembly (60). The oil port of the pilot-operated hydraulically controlled directional valve (404) is connected to the control oil port of the hydraulically controlled directional valve (403).

2. The hydraulic control system of an insulated aerial work platform according to claim 1, characterized in that, The first hydraulic pump is a large hydraulic pump (1), and the second hydraulic pump is a small hydraulic pump (2). The outlet of the large hydraulic pump (1) is connected to the inlet of the electro-hydraulic directional valve group (40) through the large pump filter (3). The return port of the electro-hydraulic directional valve group (40) is connected to the return oil integrated valve block (38) and the oil tank. The outlet of the small hydraulic pump (2) is connected to the pressure oil pipeline through the small pump filter (4), and the pressure oil pipeline is equipped with an inlet oil pipeline check valve (20). The outlet of the pressure oil pipeline is connected to the inlet of the platform control valve group (80). The inlet of the return oil pipeline is connected to the platform control valve group (80), and the outlet of the return oil pipeline is connected to the off-road return oil integrated valve block (38) through the return oil pipeline check valve (21) and the check valve (37). The off-road return oil integrated valve block (38) is connected to the oil tank through the return oil filter (39).

3. The hydraulic control system of an insulated aerial work platform according to claim 2, characterized in that, The hydraulic pump (1) is a load-sensitive variable pump. Its load-sensitive Ls port is connected to a first shuttle valve (5.1). One end of the working oil port of the first shuttle valve (5.1) is connected to the load-sensitive port of the turntable boom control valve group (70). The other end of the working oil port of the first shuttle valve (5.1) is connected to a second shuttle valve (5.2). One end of the working oil port of the second shuttle valve (5.2) is connected to the load-sensitive port of the left outrigger control valve group (50), and the other end of the working oil port of the second shuttle valve (5.2) is connected to the load-sensitive port of the right outrigger control valve group (60).

4. The hydraulic control system of an insulated aerial work platform according to claim 3, characterized in that, The left outrigger control valve assembly (50) includes a left front horizontal leg control valve (501), a left rear horizontal leg control valve (502), a left front vertical leg control valve (503), and a left rear vertical leg control valve (504); the right outrigger control valve assembly (60) includes a right front horizontal leg control valve (601), a right rear horizontal leg control valve (602), a right front vertical leg control valve (603), and a right rear vertical leg control valve (604); the left front horizontal leg control valve (501), the left rear horizontal leg control valve (502), the right front horizontal leg control valve (603), and the right rear vertical leg control valve (604); The leg control valve (601) and the right rear horizontal leg control valve (602) are both O-type center-position functional solenoid directional valves, and their two working oil ports are directly connected to the rodless chamber and the rod chamber of the horizontal cylinder (6), respectively. The left front vertical leg control valve (503), the left rear vertical leg control valve (504), the right front vertical leg control valve (603), and the right rear vertical leg control valve (604) are all Y-type center-position functional solenoid directional valves, and their two working oil ports are connected to the rodless chamber and the rod chamber of the vertical cylinder (7) through a two-way hydraulic lock (8), respectively.

5. The hydraulic control system of an insulated aerial work platform according to claim 4, characterized in that, The outlet of the hydraulic pump (2) is also connected to the inlet of the pump undercarriage relief valve (36); the outlet of the pump undercarriage relief valve (36) is connected to the return oil integrated valve block (38).

6. The hydraulic control system of an insulated aerial work platform according to claim 5, characterized in that, The turntable boom control valve group (70) is a four-way load-sensitive electro-hydraulic proportional multi-way valve, including a first-way turntable slewing control valve (701), a second-way boom luffing control valve (702), a third-way boom telescopic control valve (703), and a fourth-way boom luffing telescopic control valve (704). The two working ports of the turntable slewing control valve (701) are respectively connected to the two working ports of the slewing mechanism motor (9). The two working ports of the boom luffing control valve (702) are respectively connected to the rodless chamber and the rod chamber of the boom luffing cylinder (11) through the boom luffing balance valve (10). The first working port of the boom telescopic control valve (703) is connected to the first working port of the boom quick-extension solenoid valve (12), and the second working port of the boom telescopic control valve (703) is connected to the boom telescopic balance valve (13). The rodless chamber of the first arm telescopic cylinder (14) is connected to the second working port of the first arm quick extension solenoid valve (12); the oil inlet of the first arm quick extension solenoid valve (12) is connected to the rod chamber of the first arm telescopic cylinder (14) through the first arm telescopic balance valve (13); the first working port and the second working port of the second arm luffing telescopic control valve (704) are respectively connected to the first oil inlet and the second oil inlet of the second arm luffing telescopic switching valve (15); the first working port and the fourth working port of the second arm luffing telescopic switching valve (15) are respectively connected to the rod chamber and the rodless chamber of the second arm luffing cylinder (17) through the second arm luffing balance valve (16); the second working port and the third working port of the second arm luffing telescopic switching valve (15) are respectively connected to the rodless chamber and the rod chamber of the second arm telescopic cylinder (19) through the second arm telescopic balance valve (18).

7. The hydraulic control system of an insulated aerial work platform according to claim 6, characterized in that, The pressure oil pipeline of the insulating pipeline device is connected to the outlet of the hydraulic pump (2) through the oil inlet check valve (20) at the end of the insulating arm (22) away from the platform, and is connected to the oil inlet of the platform control valve group (80) at the end of the insulating arm (22) near the platform, and is connected to an atmospheric check valve (25); the return oil pipeline is connected to the return oil integrated valve block (38) through the return oil pipeline check valve (21) and the one-way valve (37) at the end of the insulating arm (22) away from the platform, and is connected to the return oil port of the platform control valve group (80) at the end of the insulating arm (22) near the platform, and is connected to an atmospheric check valve (25); both ends of the two insulating hoses (23) are connected to the pressure oil pipeline and the return oil pipeline respectively through quick-connect couplings (24).

8. The hydraulic control system of an insulated aerial work platform according to claim 7, characterized in that, The platform control valve group (80) includes a generator flow control valve (801), a generator system relief valve (802), a platform system relief valve (803), a hook lifting control valve (804), a boom luffing control valve (805), a platform slewing control valve (806), a platform leveling control valve (807), and a tool unloading switching valve (808). The inlet of the generator flow control valve (801) is connected to the inlet of the platform control valve group (80), and its priority port is simultaneously connected to the inlet of the generator motor (26) and the inlet of the generator system relief valve (802). Its bypass port is connected to the inlet of the platform system relief valve (803), the inlet of the hook lifting control valve (804), the inlet of the boom luffing control valve (805), the inlet of the platform slewing control valve (806), the inlet of the platform leveling control valve (807), and the tool unloading switching valve (808). The two working ports of the hook lifting control valve (804) are connected to the two working ports of the winch motor (27); the two working ports of the boom luffing control valve (805) are connected to the rodless chamber and rod chamber of the boom luffing cylinder (28) through the boom balance valve (29); the two working ports of the platform slewing control valve (806) are connected to the two working ports of the platform slewing cylinder (31) through the platform slewing balance valve (30); the two working ports of the platform leveling control valve (807) are connected to the rodless chamber and rod chamber of the platform leveling cylinder (32) through the leveling balance valve (33); the first working port of the tool unloading switching valve (808) is blocked, and the second working port is connected to the hydraulic tool pressure interface quick-change connector (34); the hydraulic tool return port quick-change connector (35) is connected to the return port of the platform control valve group (80).

9. A control method for an insulated aerial work platform, based on the hydraulic control system of an insulated aerial work platform as described in claim 8, characterized in that, Includes the following steps: When the vehicle is not in operation, the pilot electric control directional valve (404) of the electro-hydraulic directional valve group (40) is de-energized and in the neutral position, the hydraulic control directional valve (403) is in the neutral position, and the load-sensitive ports of the left outrigger control valve group (50), the right outrigger control valve group (60) and the turntable boom control valve group (70) do not provide pressure feedback to the load-sensitive valve of the hydraulic pump (1), so the hydraulic pump (1) is in a low-pressure standby state; the pressure oil of the hydraulic pump (2) returns to the neutral position through the tool unloading switching valve (808) of the platform control valve group (80) for unloading. When the upper boom needs to be operated, check whether the four vertical outriggers of the lower boom are supported in place; if the outriggers are not supported in place, the outrigger detection switch has no signal, the pilot electric control directional valve (404) of the electro-hydraulic directional valve group (40) does not switch, the hydraulic control directional valve (403) does not operate, the hydraulic pump (1) pressure oil cannot enter the turntable boom control valve group (70), and the boom operation is prohibited; if all outriggers are supported in place, the outrigger detection switch sends a signal, the pilot electric control directional valve (404) is energized and switches, the hydraulic control directional valve (403) switches, the hydraulic pump (1) pressure oil flows to the turntable boom control valve group (70), and the upper boom operation is allowed; When it is necessary to operate the outriggers, check whether the upper arm has left the arm support; If the arm has not left the arm support, the arm support detection switch is triggered, the pilot electric directional valve (404) of the electro-hydraulic directional valve group (40) is energized and reversed, the hydraulic directional valve (403) reverses, and the hydraulic pump (1) pressurized oil enters the left outrigger control valve group (50) and the right outrigger control valve group (60), allowing the outrigger to operate; if the arm has left the arm support, the arm support detection switch has no signal, the pilot electric directional valve (404) does not reverse, the hydraulic directional valve (403) does not operate, the hydraulic pump (1) pressurized oil cannot enter the left outrigger control valve group (50) and the right outrigger control valve group (60), and the outrigger operation is prohibited; The one-arm quick extension control is achieved by energizing and reversing the one-arm quick extension solenoid valve (12). The one-arm extension control valve (703) is operated to allow oil to enter the rodless chamber of the one-arm extension cylinder (14). The oil in the rod chamber enters the rodless chamber through the one-arm quick extension solenoid valve (12), forming a differential quick extension circuit. During compound action, the one-arm quick extension solenoid valve (12) is automatically energized by the program control to achieve rapid extension of the one arm under high flow requirements. The platform is powered by hydraulic pump (2) pressurized oil supplied to generator motor (26) at a fixed flow rate through generator flow control valve (801) of platform control valve group (80), which drives generator (90) to run, powering the platform load and charging the battery; the remaining oil is supplied from the bypass port to the platform leveling, rotation and hook lifting and lowering actions. The pressure control of the insulating pipeline is achieved by setting an oil inlet check valve (20) in the oil inlet pipeline of the insulating arm (22) and an atmospheric check valve (25) near the platform end, and setting an oil return check valve (21) in the oil return pipeline and an atmospheric check valve (25) near the platform end, to prevent oil backflow and the formation of a vacuum in the pipeline, and to maintain the dielectric strength. The platform automatically levels by detecting the platform tilt angle through the leveling tilt angle sensor (91). When the tilt angle exceeds the set value, the tool unloading switching valve (808) is energized so that the bypass oil circuit is no longer unloaded. At the same time, the corresponding valve head of the leveling control valve (807) is energized, driving the platform leveling cylinder (32) to act to achieve automatic leveling. Emergency retraction is achieved by setting up emergency operation knobs with positioning at both ends of the pilot electric control directional valve (404) of the electro-hydraulic directional valve group (40). In case of electrical control failure, the corresponding knob is manually turned in to switch the hydraulic control directional valve (403). The pressurized oil enters the turntable boom control valve group (70) or the left outrigger control valve group (50) and the right outrigger control valve group (60). The emergency retraction of the boom or outrigger is achieved by manually operating the hydraulic handle.

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