Hydraulic system of pure electric mining dump truck

Abstract

A pure electric mining dump truck hydraulic system comprises a hydraulic steering system and a hydraulic lifting system, and the hydraulic steering system comprises a steering plunger pump, an energy accumulator, a multi-way valve assembly, a steering valve, a two-way unloading valve, a steering cylinder and an electromagnetic reversing valve; the lifting system comprises a gear pump, an overflow valve, a lifting valve, an oil suction filter, a lifting control handle, a pilot valve block, a bounce valve, a lifting cylinder and a lifting hydraulic oil tank. And the steering plunger pump and the lifting plunger pump are driven by a double-shaft extension motor. A single motor can drive the two hydraulic systems to operate stably, space is saved, meanwhile, jamming and preparation time of the two systems during operation and switching are shortened, energy is saved, and efficiency is improved.

Description

Technical Field

[0001] The invention relates to the technical field of dump trucks, in particular to a hydraulic system of a pure electric mining dump truck. Background Art

[0002] At present, dump trucks use electronically controlled fuel systems as the power source of the vehicle hydraulic system, and use two motors to drive the steering pump and lifting pump for hydraulic operation. The engine is connected to the gearbox to control the oil circuit to control the accumulator, and the gearbox controls the accumulator oil pressure release. The entire hydraulic system lacks pressure sensor detection, and the overall safety and system consistency are insufficient. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide a pure electric mining dump truck hydraulic system to solve the problems of high motor space occupancy, high energy consumption, delay in switching back and forth between dual systems, and high cost.

[0004] In order to solve the above technical problems, the technical solution of the present invention is: a pure electric mining dump truck hydraulic system, including a hydraulic steering system and a hydraulic lifting system, the hydraulic steering system includes a steering piston pump, an accumulator, a multi-way valve assembly, a steering valve, a two-way unloading valve, a steering cylinder and an electromagnetic reversing valve; the lifting system includes a gear pump, a relief valve, a lifting valve, an oil suction filter, a lifting control handle, a pilot valve block, a rebound valve, a lifting cylinder and a lifting hydraulic oil tank; the steering piston pump and the lifting piston pump are driven by a double-axle extension motor; Hydraulic steering system: After the dump truck is started, the hydraulic oil pumped out by the steering plunger pump passes through the output pressure stabilizing assembly composed of a high-pressure filter and a proportional valve through line A to the one-way valve, and then reaches the multi-way valve assembly to be divided into two routes. One route is passed through the multi-way valve assembly through the E pipeline to charge the accumulator, and the other route is passed through the pipeline P to supply oil to the steering valve. When steering, the steering plunger pump and the accumulator supply oil to the steering valve, the two-way unloading valve and the steering cylinder through the pipeline P, and the steering plunger pump replenishes oil to the accumulator at the same time; the pressure of the hydraulic steering system is adjusted by the oil pressure switch and pressure sensor next to the multi-way valve; after the dump truck is turned off, the system will discharge the high-pressure oil of the hydraulic steering system through the electromagnetic reversing valve through the pipeline R and the high-pressure filter in the pressure relief assembly within the set time to release the internal pressure of the system; Hydraulic lifting system: When lifting, turn the lifting control handle to the lifting position. The hydraulic oil from the steering system is reduced in pressure through the pressure reducing valve of the pilot valve block, and then flows through the lifting control handle to reduce the pressure again, pushing the spool of the lifting valve to the lifting position. The hydraulic oil pumped out by the gear pump passes through the lifting valve and enters the rodless chamber of the lifting cylinder to push the piston rod, and then pushes the cargo box to flip upward to achieve lifting; when the lifting is in place, turn the lifting control handle to the holding position. At this time, both ends of the lifting valve spool are connected to the oil tank, the valve core is in the middle position, and the hydraulic oil pumped out by the gear pump directly returns to the lifting hydraulic oil tank. The rod chamber and the rodless chamber of the lifting cylinder are blocked, and the piston rod cannot move, that is, the cargo box cannot move and remains stationary.

[0005] As an improvement, the electromagnetic reversing valve is a normally closed valve. When the dump truck stops, the electromagnetic reversing valve is powered on for 30 seconds by detecting the OFF mode of the key switch, thereby releasing the pressure of the accumulator.

[0006] As an improvement, it also includes a pressure sensor, a three-way connector and a pressure switch. The pressure sensor and the pressure switch are connected in parallel through the three-way connector. The pressure sensor collects the working pressure of the hydraulic steering system as an input signal for the vehicle controller to control the speed of the hydraulic steering motor and the status of the steering system.

[0007] Compared with the prior art, the present invention has the following beneficial effects: A single motor can drive two hydraulic systems to operate smoothly, saving space while also reducing the jams and preparation time during operation and switching of the two systems, saving energy and increasing efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 This is the piping diagram of the hydraulic steering system.

[0009] Figure 2 This is the piping diagram of the hydraulic system. DETAILED DESCRIPTION

[0010] The present invention will be further described below in conjunction with the accompanying drawings.

[0011] A pure electric mining dump truck hydraulic system includes a hydraulic steering system and a hydraulic lifting system. Figure 1 As shown, the hydraulic steering system includes a steering piston pump 2, an accumulator 3, a multi-way valve assembly 4, a steering valve 5, a two-way unloading valve 6, a steering cylinder 7 and an electromagnetic reversing valve 9. Figure 2As shown, the lifting system includes a gear pump 15, a relief valve 14, a lifting valve 17, an oil suction filter 18, a lifting control handle 16, a pilot valve block 19, a rebound valve 20, a lifting cylinder 13 and a lifting hydraulic oil tank 21. The steering piston pump and the gear pump are driven by a double-axle extension motor. The steering end uses a hydraulic piston pump and the lifting end uses a reverse gear pump. The motor is fixed on the two beams by two crossbar fixings. The motor drives the hydraulic pump during the steering process, which can more conveniently control the working condition of the system, reduce heat generation, reduce the temperature of the hydraulic system, improve the working environment of the hydraulic system components, and achieve the purpose of energy saving. The upper motor is used to control the steering and lifting system, which ensures the smooth operation of the entire system while reducing costs and increasing efficiency. The two systems will not run under load at the same time to ensure that the motor has sufficient power.

[0012] Hydraulic steering system: After the dump truck is started, the hydraulic oil pumped out by the steering plunger pump 2 passes through the output voltage stabilizing assembly 12 composed of a high-pressure filter and a proportional valve through line A to reach the one-way valve, and then reaches the multi-way valve assembly 4 and is divided into two paths, one of which passes through the multi-way valve assembly 4 through the E pipeline to charge the accumulator 3, and the other passes through the pipeline P to supply oil to the steering valve 5. When steering, the steering plunger pump 2 and the accumulator 3 supply oil to the steering valve 5, the two-way unloading valve 6 and the steering cylinder 7 through the pipeline P, and the steering plunger pump 2 replenishes oil to the accumulator 3 at the same time; the pressure of the hydraulic steering system is adjusted by the oil pressure switch 8 and the pressure sensor 10 next to the multi-way valve; after the dump truck is turned off, the system will discharge the high-pressure oil of the hydraulic steering system through the electromagnetic reversing valve 9 through the pipeline R and the high-pressure filter in the pressure relief assembly 11 within the set time to release the internal pressure of the system.

[0013] Hydraulic lifting system: When lifting, turn the lifting control handle 16 to the lifting position. The hydraulic oil from the steering system is reduced in pressure through the pressure reducing valve of the pilot valve block 19, and then flows through the lifting control handle 16 to reduce the pressure again, pushing the valve core of the lifting valve 17 to the lifting position. The hydraulic oil pumped out by the gear pump 15 passes through the lifting valve 17 and enters the rodless chamber of the lifting cylinder 13 to push the piston rod, thereby pushing the cargo box to flip upward to achieve lifting; when the lifting is in place, turn the lifting control handle 16 to the holding position. At this time, both ends of the valve core of the lifting valve 17 are connected to the oil tank, the valve core is in the middle position, and the hydraulic oil pumped out by the gear pump 15 directly returns to the lifting hydraulic oil tank 21. The rod chamber and the rodless chamber of the lifting cylinder are blocked, and the piston rod cannot move, that is, the cargo box cannot move and remains stationary.

[0014] The electromagnetic reversing valve is a normally closed valve. When the dump truck stops, the electromagnetic reversing valve is powered on for 30 seconds by detecting the key switch OFF mode, thereby releasing the pressure of the accumulator.

[0015] New pressure sensors, three-way connectors and pressure switches are added. The pressure sensors and pressure switches are connected in parallel through three-way connectors. The pressure sensor collects the working pressure of the hydraulic steering system and serves as the input signal for the vehicle controller to control the speed of the hydraulic steering motor and the state of the steering system. The pressure switch mainly alarms when the pressure of the hydraulic steering system is lower than 8.3Mpa. When the pressure sensor is damaged or the controller network fails, it can still alarm the hydraulic steering system.

[0016] Steering system control logic: When the steering system is running, the lifting input end is in the floating gear, the lifting system is in an unloaded state, and the lifting system output power is extremely low; at this time, the steering input end motor speed is maintained at 2000r / min, the motor is maintained at a relatively high speed, and the steering system works normally. When the entire steering system is in the middle position, the oil pressure reaches 14.6MPa, the pressure relief valve opens, the motor maintains a low speed rotation of 700r / min, the pressure compensation ramp of the plunger pump automatically adjusts the angle, reduces the pressure oil input, and the output power of the entire steering system is close to 0.

[0017] Lifting system control logic: When the vehicle lifting system is working, the steering system plunger pump is in the neutral state, only ensuring the pressure balance at the steering system multi-way valve and other places. The output oil volume at the steering end is approximately 0, and the main load of the upper motor is to supply the lifting pilot valve to control the pressure of the oil circuit. At this time, the main load of the upper motor is the lifting system.

Claims

1. A hydraulic system for a pure electric mining dump truck, including a hydraulic steering system and a hydraulic lifting system, characterized in that: The hydraulic steering system includes a steering piston pump, an accumulator, a multi-way valve assembly, a steering valve, a two-way unloading valve, a steering cylinder and an electromagnetic reversing valve; the lifting system includes a gear pump, a relief valve, a lifting valve, an oil suction filter, a lifting control handle, a pilot valve block, a rebound valve, a lifting cylinder and a lifting hydraulic oil tank; the steering piston pump and the lifting piston pump are driven by a double-axle extension motor; Hydraulic steering system: After the dump truck is started, the hydraulic oil pumped out by the steering plunger pump passes through the output pressure stabilizing assembly composed of a high-pressure filter and a proportional valve through line A to the one-way valve, and then reaches the multi-way valve assembly to be divided into two routes. One route is passed through the multi-way valve assembly through the E pipeline to charge the accumulator, and the other route is passed through the pipeline P to supply oil to the steering valve. When steering, the steering plunger pump and the accumulator supply oil to the steering valve, the two-way unloading valve and the steering cylinder through the pipeline P, and the steering plunger pump replenishes oil to the accumulator at the same time; the pressure of the hydraulic steering system is adjusted by the oil pressure switch and pressure sensor next to the multi-way valve; after the dump truck is turned off, the system will discharge the high-pressure oil of the hydraulic steering system through the electromagnetic reversing valve through the pipeline R and the high-pressure filter in the pressure relief assembly within the set time to release the internal pressure of the system; Hydraulic lifting system: When lifting, turn the lifting control handle to the lifting position. The hydraulic oil from the steering system is reduced in pressure through the pressure reducing valve of the pilot valve block, and then flows through the lifting control handle to reduce the pressure again, pushing the spool of the lifting valve to the lifting position. The hydraulic oil pumped out by the gear pump passes through the lifting valve and enters the rodless chamber of the lifting cylinder to push the piston rod, and then pushes the cargo box to flip upward to achieve lifting; when the lifting is in place, turn the lifting control handle to the holding position. At this time, both ends of the lifting valve spool are connected to the oil tank, the valve core is in the middle position, and the hydraulic oil pumped out by the gear pump directly returns to the lifting hydraulic oil tank. The rod chamber and the rodless chamber of the lifting cylinder are blocked, and the piston rod cannot move, that is, the cargo box cannot move and remains stationary.

2. A pure electric mining dump truck hydraulic system according to claim 1, characterized in that: The electromagnetic reversing valve is a normally closed valve. When the dump truck stops, the electromagnetic reversing valve is powered on for 30 seconds by detecting the key switch OFF mode, thereby releasing the pressure of the accumulator.

3. A hydraulic system for a pure electric mining dump truck according to claim 1, characterized in that: It also includes a pressure sensor, a three-way connector and a pressure switch. The pressure sensor and the pressure switch are connected in parallel through the three-way connector. The pressure sensor collects the working pressure of the hydraulic steering system as an input signal for the vehicle controller to control the speed of the hydraulic steering motor and the status of the steering system.

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