Multi-pump hydraulic system and control method

Abstract

The invention discloses a multi-pump hydraulic system and a control method, and belongs to the technical field of hydraulic systems, the system comprises an oil tank, a first oil supply pump, a second oil supply pump, a third oil supply pump, an engine, a hydraulic generator control valve group, a hydraulic generator driving motor, a generator module, an upper vehicle arm support system and a lower vehicle walking system; the engine is in driving connection with the first oil feed pump, the second oil feed pump and the third oil feed pump, oil inlets of the first oil feed pump, the second oil feed pump and the third oil feed pump are connected with the oil tank, an oil outlet of the first oil feed pump is connected with the hydraulic generator control valve set, and the hydraulic generator control valve set is connected with the oil tank and the hydraulic generator driving motor. The hydraulic generator driving motor is connected with the generator module, an oil outlet of the second oil supply pump is connected with the upper truck boom system, and an oil outlet of the third oil supply pump is connected with the lower truck walking system; stable output is guaranteed through independent oil supply; and the combination with the upper vehicle arm support system and / or the lower vehicle walking system is realized by controlling the oil supply pump.

Description

Technical Field

[0001] The invention relates to a multi-pump hydraulic system and a control method, belonging to the technical field of hydraulic systems. Background Art

[0002] Mobile lifting work platform is a kind of aerial work equipment widely used by countries around the world, with many advantages such as flexible movement, safe and convenient operation, etc. At present, the power supply for outdoor construction site welding in my country is mainly provided by diesel generator sets on integrated welding vehicles, but the speed of existing domestic generator sets is greatly affected by load changes, and the speed adjustment time is too long, which often leads to defects during welding and affects work efficiency.

[0003] As users have higher and higher requirements for the convenience of electricity use, the product demand for mobile lifting work platform vehicle-mounted hydraulic generators has gradually become prominent. Vehicle-mounted hydraulic generators have the advantages of small size, high power-to-weight ratio, and low noise, and are widely used in the construction industry and other fields. However, the current hydraulic generator system has low transmission efficiency, slow response, and unstable speed. In the case of sudden load changes, the hydraulic motor speed will suddenly change, and it cannot provide stable voltage output and frequency output. Moreover, the current hydraulic generator system does not have startup protection measures. At the moment of startup, the output voltage will suddenly change to a very high value, causing damage to the user's handheld electrical appliances.

[0004] The hydraulic generator system currently used mainly provides oil source for the fixed displacement pump (gear pump), and the pump displacement is adjusted by the throttle valve. Figure 2 As shown, the entity adopts a method of directly integrating and fixing the hydraulic motor on the generator housing through a connecting device, one end of the connecting device is fixed on the generator, and the other end of the connecting device is connected to the hydraulic motor. The hydraulic motor drive shaft and the generator rotor are coaxially connected through a coupling to form a generator set module, and the drive of the hydraulic motor and the power generation of the generator are integrated into a power generation unit.

[0005] In summary, the prior art still has the following defects: the working flow of the hydraulic generator driving motor is unstable, resulting in unstable generator output voltage; and it cannot be combined with the actions of the upper vehicle boom system and the lower vehicle walking system. Summary of the invention

[0006] The object of the present invention is to provide a multi-pump hydraulic system and a control method.

[0007] To achieve the above objectives, the present invention is implemented by adopting the following technical solutions: In a first aspect, the present invention provides a multi-pump hydraulic system, including a fuel tank, a first fuel supply pump, a second fuel supply pump, a third fuel supply pump, an engine, a hydraulic generator control valve group, a hydraulic generator drive motor, a generator module, an upper boom system and an lower travel system; The engine drives and connects the first fuel supply pump, the second fuel supply pump and the third fuel supply pump respectively. The oil inlets of the first fuel supply pump, the second fuel supply pump and the third fuel supply pump are all connected to the fuel tank. The oil outlet of the first fuel supply pump is connected to the hydraulic generator control valve group. The hydraulic generator control valve group is respectively connected to the fuel tank and the hydraulic generator drive motor. The hydraulic generator drive motor is connected to the generator module. The oil outlet of the second fuel supply pump is connected to the upper arm system. The oil outlet of the third fuel supply pump is connected to the lower walking system.

[0008] Furthermore, the hydraulic generator control valve group includes a hydraulic generator energy-saving oil port and a generator switching valve. When the generator switching valve is energized, the oil provided by the first oil supply pump flows to the hydraulic generator drive motor through the generator switching valve. When the generator switching valve is not energized, the oil provided by the first oil supply pump flows to the oil tank through the hydraulic generator energy-saving oil port.

[0009] Furthermore, it also includes a hydraulic oil cooler, the oil outlet of the hydraulic oil cooler is connected to the oil tank, and the oil inlet of the hydraulic oil cooler is respectively connected to the oil outlets of the generator module, the upper boom system and the lower walking system.

[0010] Furthermore, the upper vehicle boom system includes a turntable main valve, and the turntable main valve includes a main valve control valve, a main arm luffing control valve, a main arm telescopic control valve, a turntable rotation control valve, a lower vehicle steering control valve and a platform motion control valve. The main valve control valve is respectively connected to the main arm luffing control valve, the main arm telescopic control valve, the turntable rotation control valve, the lower vehicle steering control valve and the platform motion control valve. After the oil provided by the second oil supply pump enters the upper vehicle boom system, it flows to each control valve connected to it through the main valve control valve.

[0011] Further, the main arm luffing control valve includes a first retracting electromagnet and a first extending electromagnet. If the main valve control valve is energized and the first retracting electromagnet is energized, the main arm luffing cylinder in the vehicle boom system performs a retracting action. If the main valve control valve is energized and the first extending electromagnet is energized, the main arm luffing cylinder in the vehicle boom system performs an extending action. The main arm telescopic control valve includes a second retracting electromagnet and a second extending electromagnet. If the main valve control valve is energized and the second retracting electromagnet is energized, the main arm telescopic cylinder in the vehicle arm frame system performs a retracting action. If the main valve control valve is energized and the second extending electromagnet is energized, the main arm telescopic cylinder in the vehicle arm frame system performs an extending action. The turntable rotation control valve includes a third retracting electromagnet and a third extending electromagnet. If the main valve control valve is energized and the third retracting electromagnet is energized, the turntable rotation cylinder in the upper vehicle arm system performs a retracting action. If the main valve control valve is energized and the third extending electromagnet is energized, the turntable rotation cylinder in the upper vehicle arm system performs an extending action. The disembarkation steering control valve includes a fourth retracting electromagnet and a fourth extending electromagnet. If the main valve control valve is energized and the fourth retracting electromagnet is energized, the disembarkation steering cylinder in the vehicle arm system performs a retracting action. If the main valve control valve is energized and the fourth extending electromagnet is energized, the disembarkation steering cylinder in the vehicle arm system performs an extending action. The platform action control valve includes a fifth retraction solenoid and a fifth extension solenoid. If the main valve control valve is energized and the fifth retraction solenoid is energized, the platform action cylinder in the upper vehicle arm system performs a retraction action. If the main valve control valve is energized and the fifth extension solenoid is energized, the platform action cylinder in the upper vehicle arm system performs an extension action.

[0012] Furthermore, it also includes a pressure sensor, which is arranged on the turntable main valve.

[0013] Furthermore, it also includes a travel pump solenoid valve, which is arranged on the third oil supply pump and is used to control the displacement of the third oil supply pump.

[0014] In a second aspect, the present invention provides a control method for controlling the system described in any one of the first aspects, comprising: If the generator switching valve is not powered, the oil provided by the first oil supply pump flows to the oil tank through the hydraulic generator energy-saving oil port, and the generator module does not work; If the generator switching valve is energized, the hydraulic oil cooler is driven to start working, and the oil provided by the first oil supply pump flows to the hydraulic generator drive motor through the generator switching valve, and the generator module works.

[0015] Furthermore, when the generator module is working and the pressure sensor detects pressure: If there is an electrical signal from the travel pump solenoid valve, the third oil supply pump is driven to supply oil to the lower vehicle travel system. At this time, the second oil supply pump also supplies oil to the upper vehicle boom system. The generator module, upper vehicle boom system and lower vehicle travel system work simultaneously. If there is no electrical signal from the travel pump solenoid valve, the third oil supply pump will not supply oil to the lower vehicle travel system. At this time, the second oil supply pump will supply oil to the upper vehicle boom system, and the generator module and the upper vehicle boom system will work at the same time.

[0016] Furthermore, when the generator module is working and the pressure sensor does not detect pressure: If there is an electrical signal from the travel pump solenoid valve, the third oil supply pump is driven to supply oil to the lower vehicle travel system. At this time, the second oil supply pump does not supply oil to the upper vehicle arm system, and the generator module and the lower vehicle travel system work at the same time; If there is no electrical signal from the travel pump solenoid valve, the third oil supply pump will not supply oil to the lower vehicle travel system. At this time, the second oil supply pump will not supply oil to the upper vehicle boom system, and the generator module will work alone.

[0017] Compared with the prior art, the beneficial effects achieved by the present invention are: The present invention provides a multi-pump hydraulic system and control method, wherein multiple oil supply pumps are used to supply oil to a hydraulic generator drive motor, an upper vehicle arm system and an lower vehicle travel system respectively, and the hydraulic generator drive motor is supplied with oil separately, so as to realize a stable input of the hydraulic motor working flow, thereby ensuring a stable output of voltage and frequency; by controlling each oil supply pump, control of different working modes of the hydraulic system is realized, thereby realizing the combination of the generator module with the upper vehicle arm system and / or the lower vehicle travel system; When the generator module is not working, the oil can return directly to the tank through the hydraulic generator energy-saving oil port without overflow energy loss. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 is a structural schematic diagram of a multi-pump hydraulic system provided by an embodiment of the present invention; Figure 2 It is a structural schematic diagram of the prior art provided by an embodiment of the present invention; Figure 3 is a three-dimensional arrangement diagram of a hydraulic generator system provided by an embodiment of the present invention; Figure 4 is a flow chart of a control method provided by an embodiment of the present invention; Figure 5 is a schematic diagram of an adaptive matching control strategy for a hydraulic generator system provided by an embodiment of the present invention; In the figure: 1. Engine; 2. First oil supply pump; 3. Second oil supply pump; 4. Hydraulic generator control valve group; 4-1. Energy-saving oil port of hydraulic generator; 4-2. Generator switching valve; 5. Generator module; 6. Hydraulic generator drive motor; 7. Hydraulic oil cooler; 8. Pressure sensor; 9. Generator fixing bracket; 10. Turntable main valve; 11. Third oil supply pump; 12. Get-off walking system. DETAILED DESCRIPTION

[0019] The present invention will be further described below in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solutions of the present invention and are not intended to limit the protection scope of the present invention.

[0020] Example 1.

[0021] The present invention provides a multi-pump hydraulic system, including an oil tank, a first oil supply pump, a second oil supply pump, a third oil supply pump, an engine, a hydraulic generator control valve group, a hydraulic generator drive motor, a generator module, an upper arm system and an lower travel system; The engine drives and connects the first fuel supply pump, the second fuel supply pump and the third fuel supply pump respectively. The oil inlets of the first fuel supply pump, the second fuel supply pump and the third fuel supply pump are all connected to the fuel tank. The oil outlet of the first fuel supply pump is connected to the hydraulic generator control valve group. The hydraulic generator control valve group is respectively connected to the fuel tank and the hydraulic generator drive motor. The hydraulic generator drive motor is connected to the generator module. The oil outlet of the second fuel supply pump is connected to the upper arm system. The oil outlet of the third fuel supply pump is connected to the lower walking system.

[0022] Oil is supplied to the hydraulic generator drive motor, the upper boom system and the lower traveling system respectively through multiple oil supply pumps. The hydraulic generator drive motor is supplied with oil separately to achieve stable input of the hydraulic motor working flow, thereby ensuring stable output of voltage and frequency. By controlling each oil supply pump, different working modes of the hydraulic system can be controlled, thereby realizing the combination of the generator module with the upper boom system and / or the lower traveling system.

[0023] Example 2.

[0024] like Figure 1 and Figure 3 As shown, the present invention provides a multi-pump hydraulic system, including an engine 1, a first oil supply pump 2, a second oil supply pump 3, a hydraulic generator control valve group 4, a hydraulic generator energy-saving oil port 4-1, a generator switching valve 4-2, a generator module 5, a hydraulic generator drive motor 6, a hydraulic oil cooler 7, a pressure sensor 8, a generator fixing bracket 9, an upper arm system, a turntable main valve 10, a third oil supply pump 11, and an undercarriage walking system 12.

[0025] like Figure 1 As shown, the engine 1 drives and connects the first fuel supply pump 2, the second fuel supply pump 3 and the third fuel supply pump 11 respectively, the oil inlets of the first fuel supply pump 2, the second fuel supply pump 3 and the third fuel supply pump 11 are all connected to the fuel tank, the oil outlet of the first fuel supply pump 3 is connected to the hydraulic generator control valve group 4, the hydraulic generator control valve group 4 is respectively connected to the fuel tank and the hydraulic generator drive motor 6, the hydraulic generator drive motor 6 is connected to the generator module 5, the oil outlet of the second fuel supply pump 3 is connected to the upper arm system, and the oil outlet of the third fuel supply pump is connected to the lower walking system 12.

[0026] like Figure 3 As shown, the generator module 5 is fixed on the generator fixing bracket 9 , and the hydraulic generator driving motor 6 is connected to the generator module 5 for driving the operation of the generator module 5 .

[0027] like Figure 1 As shown, the oil outlet of the hydraulic oil cooler 7 is connected to the oil tank, and the oil inlet of the hydraulic oil cooler 7 is connected to the oil outlets of the generator module 5, the upper boom system and the lower travel system 12 respectively.

[0028] like Figure 1As shown, the pressure sensor 8 is arranged on the turntable main valve 10 to detect whether hydraulic oil flows into the turntable main valve 10 .

[0029] It also includes a travel pump solenoid valve, which is arranged on the third oil supply pump 11 and is used to control the displacement of the third oil supply pump 11.

[0030] This multi-pump hydraulic system adopts a three-pump oil supply mode, that is, the first oil supply pump 2 (hydraulic generator oil supply pump) supplies oil to the hydraulic generator drive motor 6 alone, and the second oil supply pump 3 (arm action function pump) supplies oil to the upper arm system alone. The two do not interfere with each other and supply oil independently to ensure the stability of the hydraulic generator and arm action input flow. The specific working principle is as follows: Mode 1: Hydraulic generator energy saving mode.

[0031] The engine 1 runs at a speed of X1, driving the second oil supply pump 3 and the first oil supply pump 2 to supply oil to the hydraulic system. At this time, the generator switching valve 4-2 is not energized, and the oil pumped out by the first oil supply pump 2 returns to the oil tank T circuit through the hydraulic generator energy-saving oil port 4-1. Because it does not pass through the overflow valve, the energy loss caused by the overflow is avoided, saving energy for the whole machine operation.

[0032] Mode 2: Hydraulic generator working alone.

[0033] In this mode, the engine 1 runs at a speed of X2, driving the second oil supply pump 3 and the first oil supply pump 2 to supply oil to the hydraulic system. At this time, the generator switching valve 4-2 is energized, and the oil pumped out by the first oil supply pump 2 flows to the working port A of the hydraulic generator drive motor 6 through the switching of the generator switching valve 4-2, thereby driving the hydraulic generator drive motor 6 to work, driving the generator module 5 to generate electricity for the vehicle; at the same time, the hydraulic oil cooler 7 works to dissipate heat for the hydraulic system in time to avoid overheating of the system.

[0034] Mode 3: Hydraulic generator and upper boom action compound mode.

[0035] Mode three is mainly aimed at the working condition where the operator controls the upper boom to transfer the construction position at the same time during the operation of the hydraulic generator.

[0036] The engine 1 runs at a speed of X2, driving the second oil supply pump 3 and the first oil supply pump 2 to supply oil to the hydraulic system. At this time, the generator switching valve 4-2 is energized, and the oil pumped out by the first oil supply pump 2 flows to the working port A of the hydraulic generator drive motor 6 through the switching of the generator switching valve 4-2, thereby driving the hydraulic generator drive motor 6 to work and driving the generator module 5 to generate electricity for the vehicle.

[0037] In mode three, the second oil supply pump 3 supplies oil to the turntable main valve 10. If the boom starts to move, the main valve control valve Y3 is energized, the first extension solenoid Y1b is energized, the oil flows into the action cylinder from the B1 port, and the action cylinder (main boom luffing cylinder) is extended; the main valve control valve Y3 is energized, the first retraction solenoid Y1a is energized, the oil flows into the action cylinder from the A1 port, and the action cylinder (main boom luffing cylinder) is retracted.

[0038] When the main valve control valve Y3 is energized, the second extension solenoid Y2b is energized, and the oil flows into the second action cylinder from the B2 port, and the second action cylinder (main arm telescopic cylinder) is extended; when the main valve control valve Y3 is energized, the second retraction solenoid Y2a is energized, and the oil flows into the second action cylinder from the A2 port, and the second action cylinder (main arm telescopic cylinder) is retracted.

[0039] When the main valve control valve Y3 is energized, the third extension solenoid Y3b is energized, and the oil flows into the action cylinder three from the B3 port, and the action cylinder three (turntable rotation cylinder) is extended; when the main valve control valve Y3 is energized, the third retraction solenoid Y3a is energized, and the oil flows into the action cylinder three from the A3 port, and the action cylinder three (turntable rotation cylinder) is retracted.

[0040] When the main valve control valve Y3 is energized, the fourth extension solenoid Y4b is energized, and the oil flows into the four action cylinders from the B4 port, and the four action cylinders (getting off the vehicle steering cylinder) are extended; when the main valve control valve Y3 is energized, the fourth retraction solenoid Y4a is energized, and the oil flows into the four action cylinders from the A4 port, and the four action cylinders (getting off the vehicle steering cylinder) are retracted.

[0041] When the main valve control valve Y3 is energized, the fifth extension solenoid Y5b is energized, and the oil flows into the action cylinder five from the B5 port, and the action cylinder five (platform action cylinder) is extended; when the main valve control valve Y3 is energized, the fifth retraction solenoid Y5a is energized, and the oil flows into the action cylinder five from the A5 port, and the action cylinder five (platform action cylinder) is retracted.

[0042] At the same time, the hydraulic oil cooler 5 works to dissipate heat for the hydraulic system in time to prevent the system from overheating. Through the above hydraulic system design, the hydraulic generator can still ensure operation and power generation while the vehicle arm frame moves, thereby improving the work efficiency of the operator.

[0043] Mode 4: Hydraulic generator combined with high-speed travel and steering action.

[0044] Mode 4 is mainly aimed at the situation where the operator activates the get-off and walking steering function during the operation of the hydraulic generator to facilitate the transfer of the mobile lifting work platform.

[0045] The engine 1 runs at a speed of X2, driving the second oil supply pump 3 and the first oil supply pump 2 to supply oil to the hydraulic system. At this time, the generator switching valve 4-2 is energized, and the oil pumped out by the first oil supply pump 2 flows to the working port A of the hydraulic generator drive motor 6 through the switching of the generator switching valve 4-2, thereby driving the hydraulic generator drive motor 6 to work and driving the generator module 5 to generate electricity for the vehicle.

[0046] At the same time, the third oil supply pump 11 adjusts the pump displacement to Y1 through the electronic control program to supply oil to the vehicle disembarking system 12 to ensure that the vehicle disembarking system travels at a high speed of Z1.

[0047] During driving, the operator needs to press the steering handle if he needs to turn. At this time, the second oil supply pump 3 supplies oil to the turntable main valve 10, the main control valve Y3 is energized, the steering link Y4a / Y4b is energized, and the steering cylinder realizes the steering function; at the same time, the hydraulic oil cooler 5 works to prevent the hydraulic system from overheating. The total power and torque of the hydraulic generator, travel and steering system are set to the maximum value through the program to avoid exceeding the engine output power and torque.

[0048] Mode 5: Hydraulic generator, high-speed travel steering and vehicle arm action composite mode.

[0049] Mode 5 is mainly for when the hydraulic generator is running to generate electricity. When the operator transfers the vehicle, it involves walking and raising the boom at the same time to improve the efficiency of the transfer operation.

[0050] The engine 1 runs at a speed of X2, driving the second oil supply pump 3 and the first oil supply pump 2 to supply oil to the hydraulic system. At this time, the generator switching valve 4-2 is energized, and the oil pumped out by the first oil supply pump 2 flows to the working port A of the hydraulic generator drive motor 6 through the switching of the generator switching valve 4-2, thereby driving the hydraulic generator drive motor 6 to work and driving the generator module 5 to generate electricity for the vehicle.

[0051] At the same time, the third oil supply pump 11 adjusts the pump displacement to Y1 through the electronic control program to supply oil to the vehicle disembarking system 12 to ensure that the vehicle disembarking system travels at a high speed of Z1.

[0052] When the operator is driving, if the main boom luffing and boom raising actions are performed at the same time, the boom action function pump 3 supplies oil to the turntable main valve 10, the main control valve Y3 is energized, and the main boom luffing link Y1a / Y1b is energized to realize the luffing and raising and lowering functions; at the same time, the hydraulic oil cooler 5 works to prevent the hydraulic system from overheating.

[0053] Through the above-mentioned hydraulic system action, the composite action performance of the hydraulic generator moving and changing amplitude at the same time during operation is realized.

[0054] In this embodiment, if Figure 1As shown, A represents the working oil port leading to the A chamber of the component, B represents the working oil port leading to the B chamber of the component, P represents the oil inlet of the component, and T represents the oil return port of the component.

[0055] Example 3.

[0056] like Figure 4 As shown, the present invention provides a control method for controlling the multi-pump hydraulic system provided in Example 2.

[0057] According to information such as whether the generator switching valve 4-2 has an electrical signal, whether the pressure sensor 8 detects a pressure signal, and whether the travel pump solenoid valve has an electrical signal, the control system automatically identifies the generator operation output signal, the vehicle getting off and driving action signal, and the boom action signal. According to the engine power and torque requirements of the whole system, the program automatically inputs different currents Q to the travel pump electric proportional valve to control the travel pump displacement Y, thereby controlling the travel speed Z, ensuring that the output flow of the travel system adapts to the system power and torque requirements, thereby satisfying the hydraulic generator under different working conditions. Compound with different actions without exceeding the engine power and torque requirements, the specific control logic and process are as follows Figure 4 shown.

[0058] like Figure 4 As shown, the operation starts with the operation of the hydraulic generator (generator module 5 ).

[0059] If the generator switching valve 4-2 is not powered, the oil provided by the first oil supply pump 2 flows to the oil tank through the hydraulic generator energy-saving oil port 4-1, and the generator module 5 does not work. The state at this time is mode 1 in embodiment 2; If the generator switching valve 4-2 is energized, the hydraulic oil cooler 7 is driven to start working, and the oil provided by the first oil supply pump 2 flows to the hydraulic generator drive motor 6 through the generator switching valve 4-2, and the generator module 5 works. The state at this time may be any one of Mode 2, Mode 3, Mode 4 and Mode 5 in Example 2.

[0060] When the generator module 5 is working and the pressure sensor 8 detects pressure: If the travel pump solenoid valve has an electrical signal, the third oil supply pump 11 is driven to supply oil to the lower vehicle travel system 12. At this time, the second oil supply pump 3 also supplies oil to the upper vehicle arm system. The generator module 5, the upper vehicle arm system and the lower vehicle travel system 12 work simultaneously. The state at this time is mode 5 in embodiment 2. If there is no electrical signal from the travel pump solenoid valve, the third oil supply pump 11 does not supply oil to the vehicle travel system 12. At this time, the second oil supply pump 3 supplies oil to the vehicle arm system. The generator module 5 and the vehicle arm system work at the same time. The state at this time is mode three in Example 2.

[0061] When the generator module 5 is working and the pressure sensor 8 does not detect pressure: If the travel pump solenoid valve has an electrical signal, the third oil supply pump 11 is driven to supply oil to the lower vehicle travel system 12. At this time, the second oil supply pump 3 does not supply oil to the upper vehicle arm system. The generator module 5 and the lower vehicle travel system 12 work at the same time. The state at this time is mode 4 in embodiment 2; If there is no electrical signal from the travel pump solenoid valve, the third oil supply pump 11 does not supply oil to the lower vehicle travel system 12. At this time, the second oil supply pump 3 does not supply oil to the upper vehicle arm system. The generator module 5 works alone. The state at this time is mode 2 in Example 2.

[0062] The control system automatically identifies the flow required by the travel system based on the input signals of the hydraulic generator, boom action and travel system. After processing by the control system, the travel pump current is adaptively matched to keep the system flow in the best condition, realizing the combination with various actions while the hydraulic generator is running. The specific control is as follows: Figure 5 shown.

[0063] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A multi-pump hydraulic system, characterized in that: It includes a fuel tank, a first fuel supply pump, a second fuel supply pump, a third fuel supply pump, an engine, a hydraulic generator control valve group, a hydraulic generator drive motor, a generator module, an upper arm system and an lower travel system; The engine drives and connects the first fuel supply pump, the second fuel supply pump and the third fuel supply pump respectively. The oil inlets of the first fuel supply pump, the second fuel supply pump and the third fuel supply pump are all connected to the fuel tank. The oil outlet of the first fuel supply pump is connected to the hydraulic generator control valve group. The hydraulic generator control valve group is respectively connected to the fuel tank and the hydraulic generator drive motor. The hydraulic generator drive motor is connected to the generator module. The oil outlet of the second fuel supply pump is connected to the upper arm system. The oil outlet of the third fuel supply pump is connected to the lower walking system.

2. The multi-pump hydraulic system according to claim 1, characterized in that: The hydraulic generator control valve group includes a hydraulic generator energy-saving oil port and a generator switching valve. When the generator switching valve is energized, the oil provided by the first oil supply pump flows to the hydraulic generator drive motor through the generator switching valve. When the generator switching valve is not energized, the oil provided by the first oil supply pump flows to the oil tank through the hydraulic generator energy-saving oil port.

3. The multi-pump hydraulic system according to claim 1, characterized in that: It also includes a hydraulic oil cooler, the oil outlet of the hydraulic oil cooler is connected to the oil tank, and the oil inlet of the hydraulic oil cooler is respectively connected to the oil outlets of the generator module, the upper boom system and the lower walking system.

4. The multi-pump hydraulic system according to claim 1, characterized in that: The upper vehicle boom system includes a turntable main valve, which includes a main valve control valve, a main arm luffing control valve, a main arm telescopic control valve, a turntable rotation control valve, a lower vehicle steering control valve and a platform motion control valve. The main valve control valve is respectively connected to the main arm luffing control valve, the main arm telescopic control valve, the turntable rotation control valve, the lower vehicle steering control valve and the platform motion control valve. The oil provided by the second oil supply pump enters the upper vehicle boom system and flows to each control valve connected to it through the main valve control valve.

5. The multi-pump hydraulic system according to claim 4, characterized in that: The main arm luffing control valve includes a first retracting electromagnet and a first extending electromagnet. If the main valve control valve is energized and the first retracting electromagnet is energized, the main arm luffing cylinder in the vehicle arm frame system performs a retracting action. If the main valve control valve is energized and the first extending electromagnet is energized, the main arm luffing cylinder in the vehicle arm frame system performs an extending action. The main arm telescopic control valve includes a second retracting electromagnet and a second extending electromagnet. If the main valve control valve is energized and the second retracting electromagnet is energized, the main arm telescopic cylinder in the vehicle arm frame system performs a retracting action. If the main valve control valve is energized and the second extending electromagnet is energized, the main arm telescopic cylinder in the vehicle arm frame system performs an extending action. The turntable rotation control valve includes a third retracting electromagnet and a third extending electromagnet. If the main valve control valve is energized and the third retracting electromagnet is energized, the turntable rotation cylinder in the upper vehicle arm system performs a retracting action. If the main valve control valve is energized and the third extending electromagnet is energized, the turntable rotation cylinder in the upper vehicle arm system performs an extending action. The disembarkation steering control valve includes a fourth retracting electromagnet and a fourth extending electromagnet. If the main valve control valve is energized and the fourth retracting electromagnet is energized, the disembarkation steering cylinder in the vehicle arm system performs a retracting action. If the main valve control valve is energized and the fourth extending electromagnet is energized, the disembarkation steering cylinder in the vehicle arm system performs an extending action. The platform action control valve includes a fifth retraction solenoid and a fifth extension solenoid. If the main valve control valve is energized and the fifth retraction solenoid is energized, the platform action cylinder in the upper vehicle arm system performs a retraction action. If the main valve control valve is energized and the fifth extension solenoid is energized, the platform action cylinder in the upper vehicle arm system performs an extension action.

6. The multi-pump hydraulic system according to claim 4, characterized in that: It also includes a pressure sensor, which is arranged on the turntable main valve.

7. The multi-pump hydraulic system according to claim 1, characterized in that: It also includes a travel pump solenoid valve, which is arranged on the third oil supply pump and is used to control the displacement of the third oil supply pump.

8. A control method, characterized in that: Used to control the system according to any one of claims 1 to 7, comprising: If the generator switching valve is not powered, the oil provided by the first oil supply pump flows to the oil tank through the hydraulic generator energy-saving oil port, and the generator module does not work; If the generator switching valve is energized, the hydraulic oil cooler is driven to start working, and the oil provided by the first oil supply pump flows to the hydraulic generator drive motor through the generator switching valve, and the generator module works.

9. The control method according to claim 8, characterized in that: When the generator module is operating and the pressure sensor detects pressure: If there is an electrical signal from the travel pump solenoid valve, the third oil supply pump is driven to supply oil to the lower vehicle travel system. At this time, the second oil supply pump also supplies oil to the upper vehicle boom system. The generator module, upper vehicle boom system and lower vehicle travel system work simultaneously. If there is no electrical signal from the travel pump solenoid valve, the third oil supply pump will not supply oil to the lower vehicle travel system. At this time, the second oil supply pump will supply oil to the upper vehicle boom system, and the generator module and the upper vehicle boom system will work at the same time.

10. The control method according to claim 8, characterized in that: With the generator module operating and the pressure sensor detecting no pressure: If there is an electrical signal from the travel pump solenoid valve, the third oil supply pump is driven to supply oil to the lower vehicle travel system. At this time, the second oil supply pump does not supply oil to the upper vehicle arm system, and the generator module and the lower vehicle travel system work at the same time; If there is no electrical signal from the travel pump solenoid valve, the third oil supply pump will not supply oil to the lower vehicle travel system. At this time, the second oil supply pump will not supply oil to the upper vehicle boom system, and the generator module will work alone.

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