Lifting system and new energy off-highway dump truck

Abstract

The utility model discloses a lifting system and new energy off -highway dump truck, lifting system includes hydraulic oil tank, lifting pump, lifting control valve, lifting oil cylinder no.

Description

Technical Field

[0001] This utility model relates to the field of dump trucks. More specifically, this utility model relates to a lifting system and a new energy off-highway dump truck. Background Technology

[0002] The lifting system of off-highway dump trucks has a lifting cylinder mounted on the chassis at one end and on the cargo box at the other. The cargo box is lifted by extending the piston rod of the lifting cylinder, and lowered by retracting the piston rod. The lifting and lowering of the cargo box constitutes the unloading process. To ensure complete unloading and prevent sudden descent that could cause danger, the cargo box must remain in a lifted position while being lifted.

[0003] Currently, most mature lifting systems for new energy off-highway dump trucks in China use pneumatic control for the lifting pump's power take-off, and the lifting directional valve is also pneumatically controlled for reversing, thus achieving the lifting, holding, and lowering functions of the dump truck. However, this requires an air tank, which is a pressure vessel and poses a safety hazard. Therefore, some customers require the entire vehicle to be airless. Under this requirement, traditional off-highway dump truck lifting systems are no longer suitable, and the power take-off of the lifting pump and the control method for the lifting directional valve's reversing need to be reconsidered. Utility Model Content

[0004] One objective of this utility model is to solve at least the above-mentioned problems and to provide a lifting system and a new energy off-highway dump truck, so as to solve the problem that the traditional pneumatic lifting system of off-highway dump trucks in the prior art cannot meet the current needs. The power take-off of the lifting pump and the reversing control of the lifting control valve are both controlled by electrical signals. At the same time, it is easier to carry out intelligent upgrades after adopting electrical signal control.

[0005] To achieve these objectives and other advantages according to the present invention, a lifting system is provided, including a hydraulic oil tank, a lifting pump, a lifting control valve, a first lifting cylinder, and a second lifting cylinder; the lifting control valve includes an integrated valve body, which has an oil inlet P2, an oil return port T1, a working oil port A1, and an oil drain port L; the integrated valve body is provided with a three-position three-way electro-hydraulic directional valve, a first solenoid directional valve, and a second solenoid directional valve.

[0006] The oil inlet of the electro-hydraulic directional valve, the oil inlet of the first electromagnetic directional valve, and the oil inlet of the second electromagnetic directional valve are all connected to the oil inlet P2 through hydraulic oil circuits.

[0007] The oil outlet of the electromagnetic reversing valve is connected to the right control port of the electro-hydraulic reversing valve through a hydraulic oil circuit.

[0008] The oil outlet of the electromagnetic reversing valve II is connected to the left control port of the electro-hydraulic reversing valve through a hydraulic oil circuit.

[0009] The oil outlet of the electro-hydraulic directional valve is connected to the working oil port A1 via a hydraulic oil circuit;

[0010] The return port of the electro-hydraulic directional valve is connected to the return port T1 via a hydraulic oil circuit.

[0011] The drain ports of both the first electromagnetic directional valve and the second electromagnetic directional valve are connected to the drain port L via hydraulic oil circuits.

[0012] Both the return port T1 and the drain port L are connected to the hydraulic oil tank through hydraulic oil circuits.

[0013] The inlet of the lifting pump is connected to the hydraulic oil tank, and the outlet of the lifting pump is connected to the inlet P2; the working oil port A1 is connected to the inlets of the first lifting cylinder and the second lifting cylinder respectively.

[0014] Preferably, it also includes a gearbox, the input shaft of the lifting pump is connected to the gearbox power take-off port, and the start and stop of the gearbox power take-off port, the energization of the first electromagnetic reversing valve and the energization of the second electromagnetic reversing valve are all controlled by the electrical signal output by the external electric control handle.

[0015] When the electric control lever outputs the first electrical signal, the gearbox power take-off port starts, the second solenoid directional valve is energized, causing the second solenoid directional valve to switch to connect with the left control port of the electro-hydraulic directional valve, the first solenoid directional valve is de-energized, causing the first solenoid directional valve to reset to the default oil circuit, at this time the lifting cylinder one and the lifting cylinder two lift.

[0016] When the electric control lever outputs the second electrical signal, the gearbox power take-off port is activated, the first solenoid directional valve is energized, causing it to switch to connect with the right control port of the electro-hydraulic directional valve, and the second solenoid directional valve is de-energized, causing it to switch to the default oil circuit. At this time, the first lifting cylinder and the second lifting cylinder descend.

[0017] When the electric control lever outputs the third electrical signal, the gearbox power take-off port closes, and neither solenoid directional valve one nor solenoid directional valve two is energized. At this time, lifting cylinder one and lifting cylinder two remain stationary.

[0018] Preferably, the integrated valve body is further provided with a second check valve, a sequence valve, a pressure reducing valve, and a filter. The sequence valve and the second check valve are sequentially arranged in the hydraulic oil circuit connecting the oil inlet P2 and the oil inlet of the electro-hydraulic directional valve. The filter and the pressure reducing valve are sequentially arranged in the hydraulic oil circuit connecting the oil inlet P2 and the oil inlet of the second solenoid directional valve. The oil circuit between the pressure reducing valve and the second solenoid directional valve is connected to a branched hydraulic oil circuit. The oil inlet of the first solenoid directional valve is connected to the oil inlet P2 through the branched hydraulic oil circuit, the pressure reducing valve, and the filter.

[0019] The oil drain port of the pressure reducing valve is connected to the oil drain port L.

[0020] Preferably, the integrated valve body is further provided with a safety valve and a shuttle valve. The first oil inlet of the shuttle valve is connected to the oil inlet P2, the second oil inlet of the shuttle valve is connected to the working oil port A1, the oil outlet of the shuttle valve is connected to the oil inlet of the safety valve, the oil return port of the safety valve is connected to the oil return port T1, and the oil outlet of the safety valve is connected to the piston large chamber port on the right end of the electro-hydraulic directional valve.

[0021] Preferably, the integrated valve body is further provided with an oil inlet P1, which is connected to the excess flow EF port of the priority valve in the steering system.

[0022] The integrated valve body is also provided with a one-way valve, the oil inlet of the one-way valve is connected to the oil inlet P1, and the oil outlet of the one-way valve is connected to the oil inlet of the electro-hydraulic directional valve.

[0023] Preferably, the integrated valve body is further provided with pressure measuring ports MP, MA, and MP1;

[0024] The pressure testing port MP is connected to the oil inlet P2, and a pressure sensor is provided at the pressure testing port MP;

[0025] The pressure test port MA is connected to the working oil port A1, and the pressure test port MP1 is connected to the oil inlet port P1.

[0026] Preferably, it also includes a liquid level and temperature sensor, which is located inside the hydraulic oil tank.

[0027] Preferably, the system also includes a suction filter and a return filter. The inlet of the suction filter is connected to the inside of the hydraulic oil tank, the outlet of the suction filter is connected to the inlet P2, the inlet of the return filter is connected to the return port T, and the outlet of the return filter is connected to the inside of the hydraulic oil tank.

[0028] Preferably, the working oil port A1 is connected to the oil inlet of the first oil circuit, the oil outlet of the first oil circuit is connected to the oil inlet of the second oil circuit and the oil inlet of the third oil circuit, the oil outlet of the second oil circuit is connected to the oil inlet of the fourth oil circuit and the oil inlet of the fifth oil circuit, the oil outlet of the fourth oil circuit is connected to the oil inlet and outlet of the first lifting cylinder, and the oil outlet of the fifth oil circuit is connected to the oil inlet and outlet of the second lifting cylinder.

[0029] It also includes ball valve one, ball valve two, and quick connector. Ball valve one is located on the second oil line, ball valve two is located on the third oil line, and the oil outlet of the third oil line is connected to the quick connector.

[0030] Preferably, it also includes an external controller, an upper stop switch, and a lower stop switch, wherein the upper stop switch, the lower stop switch, and the external electric control handle are all connected to the external controller;

[0031] Specifically, when lifting cylinder one and lifting cylinder two are raised to the point where the upper stop switch is triggered, the upper stop switch generates an electrical signal and transmits it to the external controller. The external controller then controls the external electric control handle to output a third electrical signal, thereby keeping lifting cylinder one and lifting cylinder two in that position. When lifting cylinder one and lifting cylinder two are lowered to the point where the lower stop switch is triggered, the lower stop switch generates an electrical signal and transmits it to the external controller. The external controller then controls the external electric control handle to output a third electrical signal, thereby keeping lifting cylinder one and lifting cylinder two in that position.

[0032] New energy off-highway dump truck, including the aforementioned lifting system.

[0033] This utility model has at least the following beneficial effects:

[0034] By designing a hydraulic oil tank, lifting pump, lifting control valves (electro-hydraulic directional valve, solenoid directional valve one, solenoid directional valve two, check valve one, check valve two, sequence valve, pressure reducing valve, filter, safety valve, shuttle valve), lifting cylinder one, and lifting cylinder two, a lifting system is provided. The lifting pump's power take-off and the lifting control valve's directional control are both controlled by electrical signals. This solves the problem that traditional pneumatic lifting systems for off-highway dump trucks cannot meet current needs. Furthermore, the use of electrical signal control makes intelligent upgrades easier. The system also features a quick-connect connector, which can serve as an emergency rescue interface, facilitating emergency rescue operations in harsh mining environments. The electro-hydraulic directional valves also make it easier to meet the high-flow-rate requirements of large-tonnage dump trucks for the lifting system.

[0035] Other advantages, objectives and features of this invention will be partly apparent from the following description, and partly understood by those skilled in the art through study and practice of this invention. Attached Figure Description

[0036] Figure 1 This is a schematic diagram illustrating the structural principle of the lifting system according to one of the technical solutions of this utility model.

[0037] Figure Descriptions: 1-Hydraulic oil tank; 2-Suction filter; 3-Level and temperature sensor; 4-Lifting pump; 5-Lifting control valve; 501-Check valve one; 502-Sequence valve; 503-Check valve two; 504-Electro-hydraulic directional valve; 505-Shuttle valve; 506-Safety valve; 507-Solenoid directional valve one; 508-Solenoid directional valve two; 509-Pressure reducing valve; 510-Filter; 601-Ball valve one; 602-Ball valve two; 7-Quick connector; 801-Lifting cylinder one; 802-Lifting cylinder two; 901-Lower stop switch; 902-Top stop switch; 10-Return oil filter; 11-Pressure sensor. Detailed Implementation

[0038] The present invention will now be described in further detail with reference to the accompanying drawings, so that those skilled in the art can implement it based on the description.

[0039] It should be understood that terms such as “having,” “comprising,” and “including” as used herein do not exclude the presence or addition of one or more other elements or combinations thereof.

[0040] like Figure 1 As shown, this utility model provides a pure electric off-highway dump truck, including a hydraulic oil tank 1, a lifting pump 4, a lifting control valve 5, a lifting cylinder 801, and a lifting cylinder 802.

[0041] The lifting control valve 5 includes an integrated valve body, which has an oil inlet P2, an oil return port T1, a working oil port A1, and an oil drain port L. The integrated valve body is equipped with a three-position three-way electro-hydraulic directional valve 504, a solenoid directional valve one 507, and a solenoid directional valve two 508.

[0042] The oil inlet of the electro-hydraulic directional valve 504, the oil inlet of the electromagnetic directional valve 1 507, and the oil inlet of the electromagnetic directional valve 2 508 are all connected to the oil inlet P2 through hydraulic oil circuits.

[0043] The oil outlet of the electromagnetic reversing valve 507 is connected to the right control port of the electro-hydraulic reversing valve 504 through a hydraulic oil circuit.

[0044] The oil outlet of the electromagnetic reversing valve 508 is connected to the left control port of the electro-hydraulic reversing valve 504 through a hydraulic oil circuit.

[0045] The oil outlet of the electro-hydraulic directional valve 504 is connected to the working oil port A1 through a hydraulic oil circuit.

[0046] The return port of the electro-hydraulic directional valve 504 is connected to the return port T1 via a hydraulic oil circuit.

[0047] The drain ports of the electromagnetic directional valve 507 and the electromagnetic directional valve 508 are respectively connected to the drain ports through hydraulic oil circuits.

[0048] Both the return port T1 and the drain port L are connected to the hydraulic oil tank 1 via hydraulic oil circuits.

[0049] The oil inlet of the lifting pump 4 is connected to the hydraulic oil tank 1, and the oil outlet of the lifting pump 4 is connected to the oil inlet P2; the working oil port A1 is connected to the oil inlets of the first lifting cylinder 801 and the second lifting cylinder 802 respectively.

[0050] It also includes a gearbox. The input shaft of the lifting pump 4 is connected to the gearbox power take-off port. The start and stop of the gearbox power take-off port, the energization of the electromagnetic reversing valve 1 507 and the energization of the electromagnetic reversing valve 2 508 are all controlled by the electrical signals output by the external electric control handle.

[0051] When the electric control lever outputs the first electrical signal, the gearbox power take-off port is activated, and the second electromagnetic directional valve 508 is energized, causing it to switch to connect with the left control port of the electro-hydraulic directional valve 504. The first electromagnetic directional valve 507 is de-energized, causing it to reset to the default oil circuit that is not connected with the right control port of the electro-hydraulic directional valve 504. At this time, the lifting cylinder 801 and the second lifting cylinder 802 are lifted.

[0052] When the electric control lever outputs the second electrical signal, the gearbox power take-off port is activated, and the first solenoid directional valve 507 is energized, causing it to switch to connect with the right control port of the electro-hydraulic directional valve 504. The second solenoid directional valve 508 is de-energized, causing it to switch to the default oil circuit that is not connected with the left control port of the electro-hydraulic directional valve 504. At this time, the first lifting cylinder 801 and the second lifting cylinder 802 descend.

[0053] When the electric control handle outputs the third electrical signal, the gearbox power take-off port is closed, and neither the electromagnetic reversing valve 1 507 nor the electromagnetic reversing valve 2 508 is energized. At this time, the lifting cylinder 1 801 and the lifting cylinder 2 802 remain stationary.

[0054] In the above technical solution, the lifting control valve 5 includes an integrated valve body, a second check valve 503, an electro-hydraulic directional valve 504, a first solenoid directional valve 507, and a second solenoid directional valve 508, all mounted on the integrated valve body. The integrated valve body has an oil inlet P2, an oil return port T1, a working oil port A1, and an oil drain port L. The electro-hydraulic directional valve 504 is a three-position three-way electro-hydraulic directional valve. The oil outlet of the electro-hydraulic directional valve 504 is connected to the working oil port A1 through a hydraulic oil circuit. The oil return port of the electro-hydraulic directional valve 504 is connected to the oil return port T1 through a hydraulic oil circuit. The oil return port T1 is connected to the inside of the hydraulic oil tank 1 through a hydraulic oil circuit so that oil can return to the hydraulic oil tank 1.

[0055] The oil inlets of both the first electromagnetic directional valve 507 and the second electromagnetic directional valve 508 are connected to the oil inlet P2 via hydraulic circuits. The oil outlet of the first electromagnetic directional valve 507 is connected to the right control port of the electro-hydraulic directional valve 504 via a hydraulic circuit. When the electromagnet S1 of the first electromagnetic directional valve 507 is energized, the first electromagnetic directional valve 507 switches to a state connected to the right control port of the electro-hydraulic directional valve 504. When the electromagnet S1 of the first electromagnetic directional valve 507 is de-energized, the first electromagnetic directional valve 507 returns to the default oil circuit. At this time, the hydraulic circuit between the first electromagnetic directional valve 507 and the electro-hydraulic directional valve 504 is not connected, and no hydraulic oil flows from the first electromagnetic directional valve 507 into the right control port of the electro-hydraulic directional valve 504. Similarly, the oil outlet of the second electromagnetic directional valve 508 is connected to the left control port of the electro-hydraulic directional valve 504 via a hydraulic circuit. When the solenoid S2 of the second solenoid directional valve 508 is energized, the second solenoid directional valve 508 switches to a state connected to the left control port of the electro-hydraulic directional valve 504. When the solenoid S2 of the second solenoid directional valve 508 is de-energized, the second solenoid directional valve 508 returns to the default oil circuit. At this time, the hydraulic oil circuit between the second solenoid directional valve 508 and the electro-hydraulic directional valve 504 is not connected, and no hydraulic oil flows from the second solenoid directional valve 508 into the left control port of the electro-hydraulic directional valve 504. Therefore, when S1 is energized and S2 is de-energized, the electro-hydraulic directional valve 504 operates in the right position; when S2 is energized and S1 is de-energized, the electro-hydraulic directional valve 504 operates in the left position; and when neither S1 nor S2 is energized, the electro-hydraulic directional valve 504 operates in the neutral position, thereby enabling the electro-hydraulic directional valve 504 to switch to different states, and thus switch between lifting, lowering, and maintaining the neutral position.

[0056] The drain ports of the first electromagnetic directional valve 507 and the second electromagnetic directional valve 508 are respectively connected to the drain port L through a hydraulic oil circuit. The drain port L is connected to the inside of the hydraulic oil tank 1 through a hydraulic oil circuit so that when the first electromagnetic directional valve 507 and the second electromagnetic directional valve 508 need to drain oil, oil is drained to the hydraulic oil tank 1 through the drain port L.

[0057] The inlet of the lifting pump 4 is connected to the inside of the hydraulic cylinder through a hydraulic pipeline, the outlet of the lifting pump 4 is connected to the inlet P2 through a hydraulic oil circuit, the outlet of the electro-hydraulic directional valve 504 is connected to the working oil port A1 through a hydraulic oil circuit, and the working oil port A1 is connected to the inlet of the first lifting cylinder 801 and the second lifting cylinder 802.

[0058] In actual use, the input shaft of the lifting pump 4 is coaxially connected to the power take-off port of the gearbox via a drive shaft. The start and stop of the power take-off port of the gearbox are controlled by electrical signals. The energization of the first electromagnetic reversing valve 507 and the second electromagnetic reversing valve 508 is also controlled by electrical signals. Specifically, this can be achieved through an external controller and an electric control handle. The electric control handle, the gearbox, the first electromagnetic reversing valve 507, and the second electromagnetic reversing valve 508 are all connected to the external controller. When the electric control handle is turned to the first gear, a first electrical signal is output to the external controller. At this time, the external controller starts the power take-off port of the gearbox according to the generated first electrical signal. The second electromagnetic reversing valve 508 is energized, causing it to switch to connect with the left control port of the electro-hydraulic reversing valve 504. The first electromagnetic reversing valve 507 is de-energized, causing it to reset to the default oil circuit that is not connected to the right control port of the electro-hydraulic reversing valve 504. At this time, the lifting cylinders 801 and 802 are... 02 Lifting; When the electric control lever is turned to the second gear, a second electrical signal is output to the external controller. At this time, the external controller, based on the generated second electrical signal, activates the transmission power take-off port. Electromagnetic directional valve 507 is energized, causing it to switch to connect with the right control port of electro-hydraulic directional valve 504. Electromagnetic directional valve 508 is de-energized, causing it to switch to the default oil circuit, not connecting with the left control port of electro-hydraulic directional valve 504. At this time, lifting cylinder 801... Lifting cylinder 801 and lifting cylinder 802 descend; when the electric control lever is turned to the third gear, a third electrical signal is output to the external controller. At this time, the external controller disconnects the power take-off port of the gearbox according to the generated third electrical signal, and neither solenoid directional valve 507 nor solenoid directional valve 508 is energized. At this time, lifting cylinder 801 and lifting cylinder 802 remain stationary; in addition, to further improve intelligence, the external controller can also control the electric control lever to perform the operation of the first gear, second gear, and third gear.

[0059] In this technical solution, during use, when the electromagnet S2 of the second electromagnetic directional valve 508 is energized (i.e., the operation of the electric control handle (which can be operated by an external controller) outputs a second electrical signal, the same below), its corresponding oil circuit is connected (i.e., the oil outlet of the second electromagnetic directional valve 508 is connected to the left control port of the electro-hydraulic directional valve 504), the oil of the lifting pump 4 flows through the oil inlet P2 of the lifting control valve 5 through the second electromagnetic directional valve 508, and finally enters the left control port of the electro-hydraulic directional valve 504, realizing the left position switching of the electro-hydraulic directional valve 504. At this time, the hydraulic oil drawn from the hydraulic oil tank 1 by the lifting pump 4 flows out through the oil inlet P2 and the working oil port A1, and enters the large chambers of the first lifting cylinder 801 and the second lifting cylinder 802, thereby realizing the lifting function;

[0060] When the electromagnet S1 of the solenoid directional valve 507 is energized, its corresponding oil circuit is opened (that is, the oil outlet of the solenoid directional valve 507 is connected to the right control port of the electro-hydraulic directional valve 504). The oil from the lifting pump 4 enters the solenoid directional valve 507 through the oil inlet P2 of the lifting control valve 5, and finally enters the right control port of the electro-hydraulic directional valve 504, realizing the right-position switching of the electro-hydraulic directional valve 504. When the lifting pump 4 is in the rightmost position, its oil source is a low-pressure oil source, and the oil flows back to the hydraulic oil tank 1 through the return port T. Simultaneously, the electro-hydraulic directional valve 504 is in the right position. Due to the gravity of the dump truck's cargo box, the oil in the large chambers of lifting cylinder 801 and lifting cylinder 802 flows through the working port A1, then through the return channel of the electro-hydraulic directional valve 504, and finally out through port T1, returning to the hydraulic oil tank 1, thus achieving the cargo box lowering function. When both the electromagnet S2 of the second electromagnet 508 and the electromagnet S1 of the first electromagnet 507 are de-energized, the electro-hydraulic directional valve 504 operates in the neutral position, thus achieving the cargo box holding function. The drain oil from both the second electromagnet 508 and the first electromagnet 507 flows back to the hydraulic oil tank 1 through the drain port L.

[0061] In actual use, whether the electromagnet S2 of the electromagnetic reversing valve 2 508 and the electromagnet S1 of the electromagnetic reversing valve 1 507 are energized, as well as the potential signal of the lifting pump 4, are controlled by the electric control handle installed in the cab of the dump truck. Intelligent control can be achieved by using an external controller, for example, by connecting the external controller to the electric control handle to control the electric control handle to shift gears, thereby implementing lifting, lowering, and neutral operation.

[0062] The beneficial effects of adopting this technical solution are as follows: by designing a hydraulic oil tank 1, a lifting pump 4, and lifting control valves 5 (electro-hydraulic directional valve 504, solenoid directional valve one 507, solenoid directional valve two 508, check valve two 503, lifting cylinder one 801, and lifting cylinder two 802), a lifting system is provided. The power take-off of the lifting pump 4 and the directional control of the lifting control valves 5 in this lifting system are both controlled by electrical signals. This solves the problem that traditional dump trucks cannot meet the lifting system functions when there is no air source. At the same time, the use of electrical signal control makes it easier to carry out intelligent upgrades. In addition, the electro-hydraulic directional valve 504 can also more easily meet the high flow requirements of large-tonnage dump trucks for the lifting system, showing good application prospects.

[0063] In another technical solution, the integrated valve body is further provided with a second check valve 503, a sequence valve 502, a pressure reducing valve 509, and a filter 510. The sequence valve 502 and the second check valve 503 are sequentially arranged on the hydraulic oil circuit connecting the oil inlet P2 and the oil inlet of the electro-hydraulic directional valve 504. The filter 510 and the pressure reducing valve 509 are sequentially arranged on the hydraulic oil circuit connecting the oil inlet P2 and the oil inlet of the second solenoid directional valve 508. In this hydraulic oil circuit, the oil circuit between the pressure reducing valve 509 and the second solenoid directional valve 508 is connected to a branched hydraulic oil circuit. The oil inlet of the first solenoid directional valve 507 is connected to the oil inlet P2 through the branched hydraulic oil circuit, the pressure reducing valve 509, and the filter 510.

[0064] The oil drain port of the pressure reducing valve 509 is connected to the oil drain port L.

[0065] In the above technical solution, the integrated valve body is further provided with a second check valve 503, a sequence valve 502, a pressure reducing valve 509, and a filter 510. The oil inlet of the sequence valve 502 is connected to the oil inlet P2 via an oil circuit, and the oil outlet of the sequence valve 502 is connected to the oil inlet of the second check valve 503 via an oil circuit. The oil outlet of the second check valve 503 is connected to the oil inlet of the electro-hydraulic directional valve 504 via an oil circuit, thus preventing oil backflow. The oil inlet of the filter 510 is connected to the oil inlet P2 via an oil circuit. The oil outlet of 510 is connected to the oil inlet of the pressure reducing valve 509 through an oil circuit. The oil outlet of the pressure reducing valve 509 is connected to an oil circuit, which is the main oil circuit. The oil outlet of the main oil circuit is connected to a pair of branch oil circuits. The pair of branch oil circuits correspond to the first electromagnetic directional valve 507 and the second electromagnetic directional valve 508, respectively. The oil outlets of the pair of branch oil circuits are connected to the oil inlets of the first electromagnetic directional valve 507 and the second electromagnetic directional valve 508, respectively. The oil drain port of the pressure reducing valve 509 is connected to the oil drain port L through an oil circuit so that when oil needs to be drained, it can return to the hydraulic oil tank 1 through the oil drain port L.

[0066] The beneficial effects of adopting this technical solution are as follows: by setting a one-way valve 501, backflow of hydraulic fluid to the lifting pump 4 can be prevented; by setting a sequence valve 502, the lifting system can establish system pressure when the electro-hydraulic directional valve 504 is in the neutral position; by setting a pressure reducing valve 509, the hydraulic oil passing through can be depressurized to meet the switching pressure requirements of the electro-hydraulic directional valve 504; and by setting a filter 510, impurities in the hydraulic oil can be filtered to avoid damage and impact on the system or components.

[0067] In another technical solution, the integrated valve body is also provided with a safety valve 506 and a shuttle valve 505. The first oil inlet of the shuttle valve 505 is connected to the oil inlet P2, the second oil inlet of the shuttle valve 505 is connected to the working oil port A1, the oil outlet of the shuttle valve 505 is connected to the oil inlet of the safety valve 506, the oil outlet of the safety valve 506 is connected to the return oil port T1, and the oil outlet of the safety valve 506 is connected to the piston large chamber port at the right end of the electro-hydraulic directional valve 504.

[0068] In the above technical solution, the integrated valve body is also provided with a safety valve 506 and a shuttle valve 505. The shuttle valve 505 is located between the oil inlet P2 and the working oil port A1. Specifically, a hydraulic pipeline is connected between the working oil port A1 and the oil inlet. The shuttle valve 505 is provided on the hydraulic pipeline. The first oil inlet of the shuttle valve 505 is connected to the oil inlet P2 through an oil circuit. The second oil inlet of the shuttle valve 505 is connected to the working oil port A1 through an oil circuit. The oil outlet of the shuttle valve 505 is connected to the oil inlet of the safety valve 506 through an oil circuit. The oil return port of the safety valve 506 is connected to the oil return port T1 through an oil circuit. The oil outlet of the safety valve 506 is connected to the piston large chamber port at the right end of the electro-hydraulic directional valve 504.

[0069] The beneficial effect of adopting this technical solution is that by setting safety valve 506 and shuttle valve 505, the entire lifting system can be protected against pressure limitations.

[0070] In another technical solution, the integrated valve body is also provided with an oil inlet P1, which is connected to the excess flow EF port of the priority valve in the steering system.

[0071] The integrated valve body is also provided with a one-way valve 501, the oil inlet of the one-way valve 501 is connected to the oil inlet P1, and the oil outlet of the one-way valve 501 is connected to the oil inlet of the electro-hydraulic directional valve 504.

[0072] In the above technical solution, the integrated valve body is also provided with an oil inlet P1. The oil inlet P1 is connected to the EF port of the priority valve in the hydraulic steering system through an oil circuit to receive hydraulic oil from the hydraulic steering system, providing an auxiliary hydraulic oil source for the lifting of lifting cylinder 801 and lifting cylinder 802, and indirectly providing power. The hydraulic steering system is a common steering system structure in new energy dump trucks, which will not be described in detail here. The integrated valve body is also provided with a one-way valve 501. The oil inlet of the one-way valve 501 is connected to the oil inlet P1, and the oil outlet of the one-way valve 501 is connected to the oil inlet of the electro-hydraulic directional valve 504 to prevent the pump of the hydraulic steering system from being backflushed.

[0073] When in use, when the electric control lever outputs the first electrical signal, the gearbox power take-off port is activated, and the second electromagnetic directional valve 508 is energized, causing it to switch to connect with the left control port of the electro-hydraulic directional valve 504. The first electromagnetic directional valve 507 is de-energized, causing it to reset to the default oil circuit that is not connected with the right control port of the electro-hydraulic directional valve 504. At the same time, the hydraulic oil from the EF port of the priority valve of the hydraulic steering system enters the inlet port of the electro-hydraulic directional valve 504 through the inlet port P1, assisting the lifting cylinder 801 and the second lifting cylinder 802 in lifting.

[0074] When the electric control lever outputs the second electrical signal, the gearbox power take-off port is activated, and the solenoid directional valve 507 is energized, causing it to switch to connect with the right control port of the electro-hydraulic directional valve 504. The solenoid directional valve 508 is de-energized, causing it to switch to the default oil circuit that is not connected with the left control port of the electro-hydraulic directional valve 504. At the same time, the hydraulic oil at the EF port of the priority valve of the hydraulic steering system does not enter the oil inlet P1. At this time, the lifting cylinder 801 and the lifting cylinder 802 descend.

[0075] In actual use, a control valve can be installed between the hydraulic oil circuit connected to the EF port and the oil inlet P1, and its opening and closing can be controlled by an external controller to select whether the hydraulic steering system is needed.

[0076] The beneficial effect of adopting this technical solution is that by setting up an oil inlet P1, which is connected to the EF port of the priority valve in the hydraulic steering system, excess hydraulic oil from the hydraulic steering system is received, providing an auxiliary hydraulic oil source for the lifting of lifting cylinder 801 and lifting cylinder 802, thus indirectly providing power.

[0077] In another technical solution, the integrated valve body is also provided with pressure measuring ports MP, MA, and MP1;

[0078] The pressure testing port MP is connected to the oil inlet P2, and a pressure sensor 11 is provided at the pressure testing port MP;

[0079] The pressure testing port MA is connected to the working oil port A1, and the pressure testing port MP1 is connected to the oil inlet port P1;

[0080] In the above technical solution, the integrated valve body is also provided with pressure test ports MP, MA, and MP1. The pressure test port MP is connected to the oil inlet P2 through an oil circuit, the pressure test port MA is connected to the working oil port A1 through an oil circuit, and the pressure test port MP1 is connected to the oil inlet P1 through an oil circuit. In actual use, a pressure sensor 11 is set at the pressure test port MP so that the pressure of the lifting system can be monitored in real time. In addition, the MP1 port and MA port are reserved for pressure testing. The MA port can test the system pressure near the lifting cylinder, and the MP port can test the oil pressure of other systems.

[0081] In another technical solution, a liquid level and temperature sensor 3 is also included, which is installed inside the hydraulic oil tank 1. Specifically, in actual use, the liquid level and temperature sensor 3 can be connected to an external controller. The liquid level and temperature sensor 3 transmits the oil level and oil temperature information in the hydraulic oil tank 1 to the external controller to detect the oil level and oil temperature information in real time. When the oil level is lower than the design value or the oil temperature is higher than the set value, an alarm can be set to remind the user.

[0082] In another technical solution, a suction filter 2 and a return filter 10 are also included. The inlet of the suction filter 2 is connected to the inside of the hydraulic oil tank 1, and the outlet of the suction filter 2 is connected to the inlet P2. The inlet of the return filter 10 is connected to the return port T, and the outlet of the return filter 10 is connected to the inside of the hydraulic oil tank 1. Both the suction filter 2 and the return filter 10 can be installed on the hydraulic oil tank 1. The beneficial effect of this technical solution is that by setting the suction filter 2, the cleanliness of the oil entering the lifting system is ensured, effectively preventing impurities in the hydraulic oil in the hydraulic oil tank 1 from entering the lifting system and affecting the damage to components and the lifting effect.

[0083] In another technical solution, the working oil port A1 is connected to the oil inlet of the first oil circuit, the oil outlet of the first oil circuit is connected to the oil inlet of the second oil circuit and the oil inlet of the third oil circuit, the oil outlet of the second oil circuit is connected to the oil inlet of the fourth oil circuit and the oil inlet of the fifth oil circuit, the oil outlet of the fourth oil circuit is connected to the oil inlet and outlet of the lifting cylinder 801, and the oil outlet of the fifth oil circuit is connected to the oil inlet and outlet of the lifting cylinder 802.

[0084] It also includes ball valve 601, ball valve 602, and quick connector 7. Ball valve 601 is located in the second oil line, ball valve 602 is located in the third oil line, and the oil outlet of the third oil line is connected to the quick connector 7.

[0085] In the above technical solutions, such as Figure 1 As shown, the oil outlet of the working oil port A1 is connected to a first oil circuit. The oil outlet of the first oil circuit is connected to two oil circuits, namely a second oil circuit and a third oil circuit. The oil inlet of the second oil circuit is connected to the oil outlet of the first oil circuit. The oil outlet of the second oil circuit is connected to two other oil circuits, namely a fourth oil circuit and a fifth oil circuit. The oil inlets of the fourth oil circuit and the fifth oil circuit are both connected to the oil outlet of the second oil circuit. The oil outlets of the fourth oil circuit and the fifth oil circuit are respectively connected to the oil inlet of the lifting cylinder 801 and the oil inlet of the lifting cylinder 802.

[0086] Among them, the second oil line is equipped with a ball valve 601, the third oil line is equipped with a ball valve 602, and the oil outlet of the third oil line is connected to a quick connector 7.

[0087] In this technical solution, when a dump truck encounters an emergency, such as before unloading after loading, and the lifting system malfunctions and cannot lift or unload, any dump truck with the same lifting system configuration in a group can be used as a rescue vehicle. Ball valves 601 and 602 in both the rescue and malfunctioning vehicles are closed to prevent oil from leaking and polluting the environment. One end of a pipe is connected to the quick-connect fitting 7 on the rescue vehicle, and the other end is connected to the quick-connect fitting 7 on the malfunctioning vehicle. Ball valves 601 and 602 in the malfunctioning vehicle and ball valve 602 in the rescue vehicle are opened, while ball valve 601 in the rescue vehicle remains closed to isolate the lifting cylinder of the rescue vehicle. At this point, the lifting pump 4 of the rescue vehicle can be activated to lift and lower the vehicle, enabling emergency lifting, unloading, and lowering of the malfunctioning vehicle. After the rescue is completed, the vehicle can be restored to its original state.

[0088] In another technical solution, an external controller, an upper stop switch 902, and a lower stop switch 901 are also included, wherein the upper stop switch 902, the lower stop switch 901, and the external electric control handle are all connected to the external controller.

[0089] Specifically, when lifting cylinder 1 801 and lifting cylinder 2 802 are raised to the point where the upper stop switch 902 is triggered, the upper stop switch 902 generates an electrical signal and transmits it to the external controller. The external controller then controls the external electric control handle to output a third electrical signal, thereby keeping lifting cylinder 1 801 and lifting cylinder 2 802 in that position. When lifting cylinder 1 801 and lifting cylinder 2 802 are lowered to the point where the lower stop switch 901 is triggered, the lower stop switch 901 generates an electrical signal and transmits it to the external controller. The external controller then controls the external electric control handle to output a third electrical signal, thereby keeping lifting cylinder 1 801 and lifting cylinder 2 802 in that position.

[0090] The beneficial effect of adopting this technical solution is that by setting the upper stop switch 902 and the lower stop switch 901, the control of the descent to the set position and the lifting to the set position is transmitted to the external controller for control of the end of the descent and lifting actions, which is convenient to use.

[0091] This utility model also provides a new energy dump truck, which includes the aforementioned lifting system. The new energy dump truck with this lifting system solves the problem that traditional dump trucks cannot meet the lifting system function when there is no air source, and it is easier to meet the large flow requirements of large tonnage dump trucks for the lifting system, and has good application prospects.

[0092] The number of devices and processing capacity described herein are for simplification. Applications, modifications, and variations of this pure electric off-highway dump truck will be readily apparent to those skilled in the art.

[0093] Although the embodiments of this utility model have been disclosed above, they are not limited to the applications listed in the specification and embodiments. They can be applied to various fields suitable for this utility model. For those skilled in the art, other modifications can be easily made. Therefore, without departing from the general concept defined by the claims and their equivalents, this utility model is not limited to the specific details and the illustrations shown and described herein.

Claims

1. A lifting system, characterized in that, It includes a hydraulic oil tank, a lifting pump, a lifting control valve, a lifting cylinder one, and a lifting cylinder two; the lifting control valve includes an integrated valve body, which has an oil inlet P2, an oil return port T1, a working oil port A1, and an oil drain port L. The integrated valve body is equipped with a three-position three-way electro-hydraulic directional valve, a solenoid directional valve one, and a solenoid directional valve two. The oil inlet of the electro-hydraulic directional valve, the oil inlet of the first electromagnetic directional valve, and the oil inlet of the second electromagnetic directional valve are all connected to the oil inlet P2 through hydraulic oil circuits. The oil outlet of the electromagnetic reversing valve is connected to the right control port of the electro-hydraulic reversing valve through a hydraulic oil circuit. The oil outlet of the electromagnetic reversing valve II is connected to the left control port of the electro-hydraulic reversing valve through a hydraulic oil circuit. The oil outlet of the electro-hydraulic directional valve is connected to the working oil port A1 via a hydraulic oil circuit; The return port of the electro-hydraulic directional valve is connected to the return port T1 via a hydraulic oil circuit. The drain ports of both the first electromagnetic directional valve and the second electromagnetic directional valve are connected to the drain port L via hydraulic oil circuits. Both the return port T1 and the drain port L are connected to the hydraulic oil tank through hydraulic oil circuits. The inlet of the lifting pump is connected to the hydraulic oil tank, and the outlet of the lifting pump is connected to the inlet P2; the working oil port A1 is connected to the inlets of the first lifting cylinder and the second lifting cylinder respectively.

2. The lifting system as described in claim 1, characterized in that, It also includes a gearbox, the input shaft of the lifting pump is connected to the gearbox power take-off port, and the start and stop of the gearbox power take-off port, whether the first electromagnetic reversing valve is energized and whether the second electromagnetic reversing valve is energized are all controlled by the electrical signal output by the external electric control handle. When the electric control lever outputs the first electrical signal, the gearbox power take-off port starts, the second solenoid directional valve is energized, causing the second solenoid directional valve to switch to connect with the left control port of the electro-hydraulic directional valve, the first solenoid directional valve is de-energized, causing the first solenoid directional valve to reset to the default oil circuit, at this time the lifting cylinder one and the lifting cylinder two lift. When the electric control lever outputs the second electrical signal, the gearbox power take-off port is activated, the first solenoid directional valve is energized, causing it to switch to connect with the right control port of the electro-hydraulic directional valve, and the second solenoid directional valve is de-energized, causing it to switch to the default oil circuit. At this time, the first lifting cylinder and the second lifting cylinder descend. When the electric control lever outputs the third electrical signal, the gearbox power take-off port closes, and neither solenoid directional valve one nor solenoid directional valve two is energized. At this time, lifting cylinder one and lifting cylinder two remain stationary.

3. The lifting system as described in claim 1, characterized in that, The integrated valve body is also equipped with a second check valve, a sequence valve, a pressure reducing valve, and a filter. The sequence valve and the second check valve are sequentially arranged in the hydraulic oil circuit connecting the oil inlet P2 and the oil inlet of the electro-hydraulic directional valve. The filter and the pressure reducing valve are sequentially arranged in the hydraulic oil circuit connecting the oil inlet P2 and the oil inlet of the second solenoid directional valve. The oil circuit between the pressure reducing valve and the second solenoid directional valve is connected to a branched hydraulic oil circuit. The oil inlet of the first solenoid directional valve is connected to the oil inlet P2 through the branched hydraulic oil circuit, the pressure reducing valve, and the filter. The oil drain port of the pressure reducing valve is connected to the oil drain port L.

4. The lifting system as described in claim 3, characterized in that, The integrated valve body is also equipped with a safety valve and a shuttle valve. The first oil inlet of the shuttle valve is connected to the oil inlet P2, the second oil inlet of the shuttle valve is connected to the working oil port A1, the oil outlet of the shuttle valve is connected to the oil inlet of the safety valve, the oil return port of the safety valve is connected to the oil return port T1, and the oil outlet of the safety valve is connected to the piston large chamber port on the right end of the electro-hydraulic directional valve.

5. The lifting system as described in claim 1, characterized in that, The integrated valve body is also provided with an oil inlet P1, which is connected to the excess flow EF port of the priority valve in the steering system. The integrated valve body is also provided with a one-way valve, the oil inlet of the one-way valve is connected to the oil inlet P1, and the oil outlet of the one-way valve is connected to the oil inlet of the electro-hydraulic directional valve.

6. The lifting system as claimed in claim 1, characterized in that, The integrated valve body is also provided with pressure measuring ports MP, MA, and MP1. The pressure testing port MP is connected to the oil inlet P2, and a pressure sensor is provided at the pressure testing port MP; The pressure test port MA is connected to the working oil port A1, and the pressure test port MP1 is connected to the oil inlet port P1.

7. The lifting system as claimed in claim 1, characterized in that, It also includes a liquid level and temperature sensor, which is located inside the hydraulic oil tank.

8. The lifting system as claimed in claim 1, characterized in that, It also includes a suction filter and a return filter. The inlet of the suction filter is connected to the inside of the hydraulic oil tank, and the outlet of the suction filter is connected to the inlet P2. The inlet of the return filter is connected to the return port T, and the outlet of the return filter is connected to the inside of the hydraulic oil tank.

9. The lifting system as claimed in claim 1, characterized in that, The working oil port A1 is connected to the oil inlet of the first oil circuit. The oil outlet of the first oil circuit is connected to the oil inlet of the second oil circuit and the oil inlet of the third oil circuit. The oil outlet of the second oil circuit is connected to the oil inlet of the fourth oil circuit and the oil inlet of the fifth oil circuit. The oil outlet of the fourth oil circuit is connected to the oil inlet and outlet of the first lifting cylinder. The oil outlet of the fifth oil circuit is connected to the oil inlet and outlet of the second lifting cylinder. It also includes ball valve one, ball valve two, and quick connector. Ball valve one is located on the second oil line, ball valve two is located on the third oil line, and the oil outlet of the third oil line is connected to the quick connector.

10. The lifting system as claimed in claim 1, characterized in that, It also includes an external controller, an upper stop switch, and a lower stop switch, wherein the upper stop switch, the lower stop switch, and the external electric control handle are all connected to the external controller; Specifically, when lifting cylinder one and lifting cylinder two are raised to the point where the upper stop switch is triggered, the upper stop switch generates an electrical signal and transmits it to the external controller. The external controller then controls the external electric control handle to output a third electrical signal, thereby keeping lifting cylinder one and lifting cylinder two in that position. When lifting cylinder one and lifting cylinder two are lowered to the point where the lower stop switch is triggered, the lower stop switch generates an electrical signal and transmits it to the external controller. The external controller then controls the external electric control handle to output a third electrical signal, thereby keeping lifting cylinder one and lifting cylinder two in that position.

11. A new energy off-highway dump truck, characterized in that, Includes the lifting system as described in any one of claims 1 to 10.

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