Multifunctional hydraulic system of unmanned transport vehicle and transport vehicle

Abstract

The invention discloses a multifunctional hydraulic system of an unmanned transport vehicle and the transport vehicle. The multifunctional hydraulic system comprises a pump station, a steering loop, a braking loop and an auxiliary loop. The pump station comprises a hydraulic oil tank and a hydraulic valve block; the braking loop and the auxiliary loop are respectively connected with a hydraulic oil tank pipeline; the hydraulic valve block is used for controlling communication of the steering loop and the hydraulic oil tank, the steering loop comprises the steering valve block, and the steering valve block is regulated and controlled by the hydraulic valve block to achieve the steering function. The brake loop and the auxiliary loop are connected with the hydraulic oil tank through pipelines, branch valve blocks of the brake loop and the auxiliary loop are omitted, meanwhile, the hydraulic valve block is arranged to control communication of the steering loop and the hydraulic oil tank, the loops are designed in a separated mode, and faults of the single loop cannot be transversely transmitted; simultaneous voltage loss and failure of other loops when a single loop fails are avoided; and meanwhile, only the branch valve block in the steering loop is reserved, so that the unmanned vehicle can complete steering zeroing and the steering action working condition under the emergency pressure loss condition by one person conveniently.

Description

Technical Field

[0001] The invention relates to the field of vehicle control, and in particular to a multifunctional hydraulic system of an unmanned transport vehicle and the transport vehicle. Background Art

[0002] With the rapid development of unmanned driving technology, unmanned transport vehicles are widely used in industrial manufacturing, port logistics, warehouse management and other fields. As a key component, the hydraulic system is responsible for steering, braking, cargo clamping and support operation. However, there are many technical problems with the existing hydraulic system of unmanned transport vehicles. However, there are design problems in the existing hydraulic system: the circuits are not effectively isolated, resulting in a single circuit failure that affects the operation of the entire system; at the same time, the hydraulic system has a complex structure, occupies a large space, and the integrated design of the valve block and the oil tank is prone to noise and damage due to vibration. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide a multifunctional hydraulic system of an unmanned transport vehicle and a transport vehicle, so as to solve the problem that a single circuit failure of the hydraulic system affects other circuits.

[0004] In order to solve the above technical problems, the technical solution adopted by the present invention is: A multifunctional hydraulic system for an unmanned transport vehicle, comprising a pump station, a steering circuit, a braking circuit and an auxiliary circuit; The pump station includes a hydraulic oil tank and a hydraulic valve block; The brake circuit and the auxiliary circuit are respectively connected to the hydraulic oil tank pipeline; The hydraulic valve block is used to control the communication between the steering circuit and the hydraulic oil tank. The steering circuit includes a steering valve block. The steering valve block is regulated by the hydraulic valve block to achieve a steering function.

[0005] In order to solve the above technical problems, another technical solution adopted by the present invention is: An unmanned transport vehicle comprises a multifunctional hydraulic system of the unmanned transport vehicle and a pump station bracket, wherein the hydraulic oil tank and the hydraulic valve block are respectively arranged on both sides of the pump station bracket.

[0006] The beneficial effects of the present invention include at least: providing a multifunctional hydraulic system and a transport vehicle for an unmanned transport vehicle, by connecting the braking circuit and the auxiliary circuit to the hydraulic oil tank pipeline respectively, eliminating the brake circuit and the auxiliary circuit sub-valve blocks, and setting a hydraulic valve block to control the connection between the steering circuit and the hydraulic oil tank, so that the circuits are separated by a design, the failure of a single circuit will not be transmitted laterally, and the failure of other circuits due to simultaneous decompression when a single circuit fails is avoided; at the same time, only the sub-valve block in the steering circuit is retained, so that the unmanned vehicle can complete the steering zeroing and the steering action conditions in the event of emergency decompression by a single person; in addition, the hydraulic valve block and the hydraulic oil tank are divided and placed on both sides of the pump station bracket, so that the two are designed separately, avoiding the problem of the oil tank being cracked and leaking due to the noise caused by the resonance of the valve block, saving layout space and improving the stability of the unmanned transport vehicle. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 It is a schematic diagram of a multifunctional hydraulic system of an unmanned transport vehicle in an embodiment of the present invention; Figure 2 is a schematic diagram of a hydraulic valve block in an embodiment of the present invention; Figure 3 is a schematic diagram of a steering valve block in an embodiment of the present invention; Description of labels: 1. Hydraulic valve block; 2. Hydraulic oil tank; 3. Steering valve block; 31. Three-position four-way proportional valve; 32. Accumulator; 33. Stop valve; 4. Steering cylinder; 5. Shaft end brake cylinder; 6. Parking brake cylinder; 7. Clamping cylinder; 8. Variable piston pump; 9. Pump station bracket; 10. Return oil cooling module; P, oil inlet; T, oil outlet; A, first function port; B, second function port; 1DT, electromagnetic relief valve; 2-7DT, electromagnetic reversing valve; 8DT, mechanical relief valve; DETAILED DESCRIPTION In order to explain the technical content, achieved objectives and effects of the present invention in detail, the following is an explanation in combination with the implementation modes and the accompanying drawings.

[0008] Please refer to Figure 1 as well as Figure 2 , a multifunctional hydraulic system of an unmanned transport vehicle, including a pump station, a steering circuit, a braking circuit and an auxiliary circuit; The pump station includes a hydraulic oil tank 2 and a hydraulic valve block 1; The brake circuit and the auxiliary circuit are respectively connected to the hydraulic oil tank 2 pipeline; The hydraulic valve block 1 is used to control the communication between the steering circuit and the hydraulic oil tank 2 . The steering circuit includes a steering valve block 3 . The steering valve block 3 is regulated by the hydraulic valve block 1 to achieve a steering function.

[0009] From the above description, it can be seen that the beneficial effects of the present invention are: by connecting the brake circuit and the auxiliary circuit to the hydraulic oil tank 2 pipeline respectively, and canceling the sub-valve block design, the hydraulic system structure is greatly simplified, while reducing the complexity of the system layout, avoiding the problem of a single circuit failure causing other circuits to lose pressure and fail. In addition, only the sub-valve block in the steering circuit is retained, making the steering function more independent, facilitating the unmanned transport vehicle to complete emergency operations through the steering function in the event of an emergency loss of pressure, and enhancing the reliability and maintainability of the system. For example, during the operation of the unmanned vehicle, if a pressure relief failure occurs in a circuit of the hydraulic system, other circuits can still maintain normal functions to ensure the continuity of basic operations.

[0010] Preferably, an electromagnetic overflow valve 1DT is provided in the hydraulic valve block 1. When the electromagnetic overflow valve 1DT is energized, the hydraulic pump works by upward pressure, and when the electromagnetic overflow valve 1DT loses power, the hydraulic pump is unloaded.

[0011] Please refer to Figure 3 In some embodiments, the steering circuit also includes a steering cylinder 4, the steering valve block 3 includes a three-position four-way proportional valve 31, the three-position four-way proportional valve 31 includes an oil inlet P, an oil outlet T and a first functional port A and a second functional port B, the oil inlet P is connected to the hydraulic valve block 1 pipeline, the oil outlet T is connected to the hydraulic oil tank 2 pipeline, the first functional port A and the second functional port B are respectively connected to the steering cylinder 4 pipeline, and the steering cylinder 4 is used to realize the steering function.

[0012] From the above description, it can be seen that by adopting a three-position four-way proportional valve 31 as the steering valve block 3 to replace the traditional multi-valve design, not only the number of valves in the hydraulic circuit is significantly reduced, but also the accuracy and efficiency of the steering function are improved. The design of the three-position four-way proportional valve 31 allows the hydraulic oil to flow to different cavities of the steering cylinder 4 according to the control signal, thereby realizing the vehicle's left turn, right turn or keeping straight. The oil inlet P is connected to the hydraulic valve block 1 to ensure stable pressure, while the oil outlet T is connected to the hydraulic oil tank 2 through a pipeline to achieve rapid pressure relief. This design reduces internal leakage and heating problems, while improving the energy saving and steering response speed of the unmanned vehicle. For example, when the unmanned vehicle needs to make precise path adjustments, the proportional valve can adjust the flow and direction in real time according to the signal to achieve high-precision steering control.

[0013] It is understandable that in the existing AVG (automatic guided vehicle) vehicles, each steering cylinder 4 is usually equipped with two two-position three-way proportional valves. Based on the two-axle design of the vehicle, it is necessary to control the four two-position three-way proportional valves used for steering and the two proportional relief valves used for braking, which consumes 6 precious PLC analog points; at the same time, the use of the two-position three-way proportional valve usually requires the use of two sets of balancing circuits for locking the cylinder when there is no system pressure. In actual use, the system of the double balancing valve makes the two chambers of the cylinder connected, resulting in incomplete locking and poor steering accuracy. In the present invention, only the three-position four-way proportional valve 31 and two ordinary solenoid valves for controlling the two steerings are needed, and only two analog points and two digital points are needed, which greatly reduces the cost of purchased parts, greatly reduces the complexity of the circuit and the amount of program calculation in the control, and ensures the braking effect; at the same time, the present invention uses a two-way hydraulic lock for the above-mentioned three-position four-way proportional valve 31 to realize the locking function, thereby solving the accuracy problem existing in the prior art.

[0014] Preferably, a pressure compensator is also provided in the steering circuit to ensure the consistency of the pressure difference after the solenoid valve in the event of a sudden load change.

[0015] In some embodiments, the steering circuit also includes an accumulator 32 and a stop valve 33, the accumulator 32 is connected to the steering valve block 3 by a pipeline, and the stop valve 33 is arranged between the accumulator 32 and the steering valve block 3; the accumulator 32 is used to assist the steering valve block 3 in maintaining pressure, and the stop valve 33 is used to control the opening pressure or pressure relief of the accumulator 32.

[0016] From the above description, it can be seen that by adding an accumulator 32 and a shut-off valve 33 to the steering circuit, the reliable operation of the steering system can be ensured in the event of pressure loss or emergency. The accumulator 32 can store the pressure of the hydraulic oil, provide the necessary pressure-maintaining function when the system pressure is lost, and assist the steering valve block 3 in maintaining the continuity of the steering operation. The setting of the shut-off valve 33 can control the charging or depressurization of the accumulator 32 as needed, thereby achieving efficient steering management and emergency handling. For example, during the operation of an unmanned vehicle, if a hydraulic pump fails and causes insufficient system pressure, the pressure in the accumulator 32 can maintain the steering function for a short period of time, helping the vehicle to park safely or complete emergency evasive actions.

[0017] Please refer to Figure 1 to Figure 2 In some embodiments, the braking circuit and the auxiliary circuit both include an electromagnetic reversing valve and a mechanical overflow valve 8DT. The mechanical overflow valve 8DT is arranged between the electromagnetic reversing valve and the connecting pipeline of the hydraulic oil tank 2; the electromagnetic reversing valve is used to control the action of the functional cylinder so that the cylinder can realize the braking function or the auxiliary function.

[0018] From the above description, it can be seen that by using the electromagnetic reversing valve and the mechanical overflow valve 8DT in the brake circuit and the auxiliary circuit, the control difficulty and energy consumption of the hydraulic system are significantly reduced. The electromagnetic reversing valve is used to quickly switch the flow direction of the hydraulic oil, and the mechanical overflow valve 8DT sets the system pressure, avoiding the overload or continuous internal leakage and heating problems of the hydraulic system, and improving the efficiency and stability of the system. At the same time, the overflow valve is moved between the connecting pipeline between the electromagnetic valve and the hydraulic oil tank 2 to avoid the phenomenon of continuous heating when the brake is not executed, so that the heat generated by the hydraulic system of the present invention when the brake is not executed is also significantly reduced.

[0019] In some embodiments, the brake circuit includes a service brake circuit and a parking brake circuit; The service brake circuit includes an axle end brake cylinder 5, and the two axle end brake cylinders 5 are respectively connected to the electromagnetic reversing valve 2DT and the electromagnetic reversing valve 3DT pipeline, and the electromagnetic reversing valve 2-3DT is used to control the axle end brake cylinder 5 to achieve service braking; The parking brake circuit includes a parking brake cylinder 6. The two parking brake cylinders 6 are respectively connected to the electromagnetic reversing valve 4DT and the electromagnetic reversing valve 5DT pipeline. The electromagnetic reversing valve 4-5DT is used to control the parking brake cylinder 6 to achieve service braking.

[0020] From the above description, it can be seen that the separation design of the service brake circuit and the parking brake circuit enables the two braking functions to be controlled independently, thereby enhancing the safety and flexibility of the vehicle. The service brake circuit realizes real-time braking of the wheels through the shaft end brake cylinder 5, which is suitable for the deceleration and parking requirements during the operation of the vehicle; while the parking brake circuit realizes reliable fixation of the vehicle in a stationary state through the parking brake cylinder 6 to prevent sliding or accidental movement.

[0021] In some embodiments, the brake circuit is a power-off brake circuit.

[0022] From the above description, it can be seen that the power-off braking design of the brake circuit provides a passive safety mechanism, that is, when the system power fails or the power is accidentally cut off, the brake system can still maintain its function to ensure that the vehicle stops and is in a safe state. The power-off braking circuit can achieve driving braking through the accumulator 32 when the power is lost, and trigger the parking brake after power loss or pressure loss through the spring, and automatically apply braking force after the electromagnetic reversing valve is powered off to prevent the vehicle from losing control. For example, during the driving of an unmanned vehicle, if the power system fails, the power-off braking circuit can quickly trigger emergency braking to ensure vehicle safety.

[0023] In some embodiments, the auxiliary circuit includes a clamping cylinder 7, and the two clamping cylinders 7 are respectively connected to the electromagnetic reversing valve 6DT and the electromagnetic reversing valve 7DT pipelines, and the electromagnetic reversing valve is used to control the clamping cylinder 7 to realize the deployment or closing of the transport bracket. By arranging the clamping cylinder 7 and the electromagnetic reversing valve in the auxiliary circuit, the automatic control of the transport bracket is realized, so that the transport bracket can be quickly deployed or closed, and the efficiency and adaptability of the unmanned vehicle in the cargo loading and unloading process are improved. The action of the clamping cylinder 7 is controlled by the electromagnetic reversing valve, and the clamping mechanism is pushed by hydraulic oil to achieve the stable fixation or release of the transported goods. For example, when the unmanned vehicle transports a 40-foot container through a 40-foot bracket, the clamping cylinder 7 can ensure that the cargo is stable during driving, and quickly release the cargo after arriving at the destination, completing efficient operations.

[0024] In some embodiments, the pump station further includes a variable piston pump 8 and a remote control valve, wherein the remote control valve is used to receive a control signal to adjust the head of the variable piston pump 8. By integrating the variable piston pump 8 and the remote control valve in the hydraulic valve block 1, accurate regulation of the pressure and flow of the hydraulic system is achieved, and the adaptability and energy efficiency of the system are improved. The remote control valve can receive a control signal and adjust the head of the variable piston pump 8 according to real-time needs, avoiding the problem of excessive oil supply or insufficient pressure.

[0025] It is understandable that in the prior art, a quantitative gear pump is usually used as an oil pump. In the present invention, a variable piston pump 8 is used instead, and a remote control valve and an electromagnetic overflow valve are configured. The pressure adjustment of the piston pump can be achieved through the remote control valve, and the electromagnetic overflow valve is used to achieve the heat dissipation of the system's internal circulation when the hydraulic system does not need to be operated. In addition, the action conditions of the 40-foot bracket are added, and an electromagnetic ball valve is used to control whether this circuit is pressurized to increase the scalability of the system. In addition to the double 40-foot bracket, other compatible expansion brackets can be designed in the future to complete the vehicle function expansion. At the same time, after the original circuit is changed to a plunger pump, an oil circuit is usually added for feedback of load changes. The AGV in the present invention does not use this dynamic adjustment circuit for pressure regulation, but uses a mechanical overflow valve 8DT to remotely control the oil pump, which is convenient for quickly adjusting the system pressure from the front side of the hydraulic station, and the internal circulation is achieved through an additional mechanical overflow valve 8DT, so there is no need for adaptive design.

[0026] An unmanned transport vehicle includes a multifunctional hydraulic system of the unmanned transport vehicle and a pump station bracket 9, wherein the hydraulic oil tank 2 and the hydraulic valve block 1 are respectively arranged on both sides of the pump station bracket 9. By placing the hydraulic oil tank 2 and the hydraulic valve block 1 on both sides of the pump station bracket 9, respectively, a separate design is adopted, which not only saves the layout space of the pump station, but also effectively avoids the impact of the vibration of the hydraulic valve block 1 on the oil tank, thereby reducing noise and eliminating the risk of vibration cracking and oil leakage. This layout optimization significantly improves the operating stability of the unmanned vehicle hydraulic system. For example, under harsh road conditions, the hydraulic pump station of the unmanned vehicle can maintain low noise and high reliability to meet the operating requirements in complex environments.

[0027] In some embodiments, a frame assembly is also included, and at least part of the connecting pipelines between the pump station and the steering circuit, the brake circuit and the auxiliary circuit are stainless steel pipelines, and at least part of the stainless steel pipelines are arranged outside the frame assembly. By using stainless steel materials for the connecting pipelines between the pump station and each circuit and arranging them outside the frame assembly, not only the corrosion resistance and pressure resistance of the pipelines are enhanced, but also the layout efficiency and maintenance convenience of the pipelines are improved. Stainless steel pipelines can withstand higher working pressures and temperature differences, and meet the long-term operation requirements of unmanned vehicles in a variety of complex environments.

[0028] Please refer to Figures 1 to Figure 2 , Embodiment 1 of the present invention is: A multifunctional hydraulic system for an unmanned transport vehicle, comprising a pump station, a steering circuit, a braking circuit and an auxiliary circuit; The pump station includes a hydraulic oil tank 2 and a hydraulic valve block 1; The brake circuit and the auxiliary circuit are respectively connected to the hydraulic oil tank 2 pipeline; The hydraulic valve block 1 is used to control the communication between the steering circuit and the hydraulic oil tank 2 . The steering circuit includes a steering valve block 3 . The steering valve block 3 is regulated by the hydraulic valve block 1 to achieve a steering function.

[0029] That is, in this embodiment, it can be seen from the above description that the beneficial effect of the present invention is that by connecting the brake circuit and the auxiliary circuit to the hydraulic oil tank 2 pipeline respectively and canceling the sub-valve block design, the hydraulic system structure is greatly simplified, while reducing the complexity of the system layout. The brake circuit and the auxiliary circuit share the hydraulic valve block 1, but the independence between the circuits is maintained, so that the function of each circuit is clear, and the problem of a single circuit failure causing other circuits to lose pressure and fail is avoided. In addition, only the sub-valve block in the steering circuit is retained, making the steering function more independent, which is convenient for the unmanned transport vehicle to complete emergency operations through the steering function in the event of emergency decompression, and enhancing the reliability and maintainability of the system.

[0030] Specifically, the pump station also includes a variable piston pump 8 and a remote control valve, and the remote control valve is used to receive a control signal to adjust the head of the variable piston pump 8. By integrating the variable piston pump 8 and the remote control valve in the hydraulic valve block 1, accurate regulation of the pressure and flow of the hydraulic system is achieved, and the adaptability and energy efficiency of the system are improved. The remote control valve can receive a control signal and adjust the head of the variable piston pump 8 according to real-time needs, avoiding the problem of excessive oil supply or insufficient pressure.

[0031] Please refer to Figures 2 to 3 , Embodiment 2 of the present invention is: On the basis of the first embodiment, the steering circuit further includes a steering cylinder 4, the steering valve block 3 includes a three-position four-way proportional valve 31, the three-position four-way proportional valve 31 includes an oil inlet P, an oil outlet T and a first functional port A and a second functional port B, the oil inlet P is connected to the hydraulic valve block 1 pipeline, the oil outlet T is connected to the hydraulic oil tank 2 pipeline, the first functional port A and the second functional port B are respectively connected to the steering cylinder 4 pipeline, and the steering cylinder 4 is used to realize the steering function. A pressure compensator is also provided in the steering circuit to ensure the consistency of the pressure difference after the solenoid valve in the case of a sudden load change. The steering circuit also includes an accumulator 32 and a stop valve 33, the accumulator 32 is connected to the steering valve block 3 pipeline, and the stop valve 33 is arranged between the accumulator 32 and the steering valve block 3; the accumulator 32 is used to assist the steering valve block 3 in maintaining pressure, and the stop valve 33 is used to control the opening pressure or pressure relief of the accumulator 32.

[0032] By adopting a three-position four-way proportional valve 31 as the steering valve block 3 to replace the traditional multi-valve design, not only the number of valves in the hydraulic circuit is significantly reduced, but also the accuracy and efficiency of the steering function are improved. The design of the three-position four-way proportional valve 31 allows the hydraulic oil to flow to different chambers of the steering cylinder 4 according to the control signal, thereby enabling the vehicle to turn left, turn right or keep going straight. The oil inlet P is connected to the hydraulic valve block 1 to ensure stable pressure, while the oil outlet T is connected to the hydraulic oil tank 2 through a pipeline to achieve rapid pressure relief. This design reduces internal leakage and heating problems, while improving the energy efficiency and steering response speed of the unmanned vehicle.

[0033] The braking circuit and the auxiliary circuit both include an electromagnetic reversing valve and a mechanical overflow valve 8DT. The mechanical overflow valve 8DT is arranged between the electromagnetic reversing valve and the connecting pipeline of the hydraulic oil tank 2. The electromagnetic reversing valve is used to control the action of the functional cylinder so that the cylinder can realize the braking function or the auxiliary function.

[0034] The brake circuit includes a service brake circuit and a parking brake circuit; The service brake circuit includes an axle end brake cylinder 5, and the two axle end brake cylinders 5 are respectively connected to the electromagnetic reversing valve 2DT and the electromagnetic reversing valve 3DT pipeline, and the electromagnetic reversing valve is used to control the axle end brake cylinder 5 to achieve service braking; The parking brake circuit includes a parking brake cylinder 6. The two parking brake cylinders 6 are respectively connected to the electromagnetic reversing valve 4DT and the electromagnetic reversing valve 5DT pipeline. The electromagnetic reversing valve is used to control the shaft end brake cylinder 5 to realize service braking.

[0035] Specifically, the steering circuit, the brake circuit and the auxiliary circuit share the same mechanical overflow valve 8DT. By using the electromagnetic reversing valve and the mechanical overflow valve 8DT in the brake circuit and the auxiliary circuit, the control difficulty and energy consumption of the hydraulic system are significantly reduced. The electromagnetic reversing valve is used to quickly switch the flow direction of the hydraulic oil, and the mechanical overflow valve 8DT avoids the overload or continuous internal leakage and heating problems of the hydraulic system by setting the pressure value, thereby improving the efficiency and stability of the system. At the same time, the overflow valve is moved between the connecting pipeline between the electromagnetic valve and the hydraulic oil tank 2 to avoid the phenomenon of continuous heating when the brake is not executed, so that the heat generation of the hydraulic system of the present invention when the brake is not executed is also significantly reduced.

[0036] At the same time, the braking circuit is a power-off braking circuit. The power-off braking design of the braking circuit provides a passive safety mechanism, that is, when the system power fails or the power is accidentally cut off, the braking system can still maintain its function to ensure that the vehicle stops and is in a safe state. The power-off braking circuit can automatically apply braking force after the electromagnetic reversing valve is powered off through the auxiliary function of spring loading or accumulator 32 to prevent the vehicle from losing control.

[0037] The auxiliary circuit includes a clamping cylinder 7, and the two clamping cylinders 7 are respectively connected to the electromagnetic reversing valve 6DT and the electromagnetic reversing valve 7DT pipelines, and the electromagnetic reversing valve is used to control the clamping cylinder 7 to realize the deployment or closing of the transport bracket. By arranging the clamping cylinder 7 and the electromagnetic reversing valve in the auxiliary circuit, the automatic control of the transport bracket is realized, so that the transport bracket can be quickly deployed or closed, and the efficiency and adaptability of the unmanned vehicle in the cargo loading and unloading process are improved. The action of the clamping cylinder 7 is controlled by the electromagnetic reversing valve, and the clamping mechanism is pushed by hydraulic oil to achieve the stable fixation or release of the transported goods. For example, when the unmanned vehicle transports a 40-foot container through a 40-foot bracket, the clamping cylinder 7 can ensure that the goods are stable during driving, and quickly release the goods after arriving at the destination to complete efficient operations.

[0038] In addition, the hydraulic system also includes an oil return cooling module 10. The cooling module includes an oil return pipeline connected to each circuit, and the pipeline is provided with an air cooler, an oil filter and an oil blockage switch.

[0039] Embodiment 3 of the present invention is: An unmanned transport vehicle includes a multifunctional hydraulic system and a pump station bracket 9 of the unmanned transport vehicle, wherein the hydraulic oil tank 2 and the hydraulic valve block 1 are respectively arranged on both sides of the pump station bracket 9. By placing the hydraulic oil tank 2 and the hydraulic valve block 1 on both sides of the pump station bracket 9 respectively, a separate design is adopted, which not only saves the layout space of the pump station, but also effectively avoids the influence of the vibration of the hydraulic valve block 1 on the oil tank, thereby reducing noise and eliminating the risk of vibration cracking and oil leakage. At the same time, the unmanned transport vehicle also includes a frame assembly, and at least part of the connecting pipelines between the pump station and the steering circuit, the brake circuit and the auxiliary circuit are stainless steel pipelines, and the stainless steel pipelines are at least partially arranged outside the frame assembly. By using stainless steel material for the connecting pipelines between the pump station and each circuit and arranging them outside the frame assembly, not only the corrosion resistance and pressure resistance of the pipeline are enhanced, but also the layout efficiency and maintenance convenience of the pipeline are improved.

[0040] In summary, the multifunctional hydraulic system and transport vehicle of an unmanned transport vehicle provided by the present invention use a large number of stainless steel pipes and the pipes are externally arranged, which is conducive to maintenance and troubleshooting. The steering circuit is separated from the service brake and parking brake circuits, and the failure of a single circuit will not affect other parts. The design of the pressure reducing valve and the overflow valve is optimized to reduce system leakage and heat generation; the service braking mode is changed from power-on braking to power-off braking, and the brake can be easily released when towing is required; in addition, the system pressure supply adopts a variable piston pump, supports remote pressure adjustment, and adds an additional extended working condition application, which can be used for double 40-foot bracket action.

[0041] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent transformations made using the contents of the present invention's specification and drawings, or directly or indirectly applied in related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A multifunctional hydraulic system for an unmanned transport vehicle, characterized in that: Includes pump station, steering circuit, brake circuit and auxiliary circuit; The pump station includes a hydraulic oil tank and a hydraulic valve block; The brake circuit and the auxiliary circuit are respectively connected to the hydraulic oil tank pipeline; The hydraulic valve block is used to control the communication between the steering circuit and the hydraulic oil tank. The steering circuit includes a steering valve block. The steering valve block is regulated by the hydraulic valve block to achieve a steering function.

2. The multifunctional hydraulic system of an unmanned transport vehicle according to claim 1, characterized in that: The steering circuit also includes a steering cylinder, the steering valve block includes a three-position four-way proportional valve, the three-position four-way proportional valve includes an oil inlet, an oil outlet, and a first functional port and a second functional port, the oil inlet is connected to the hydraulic valve block pipeline, the oil outlet is connected to the hydraulic oil tank pipeline, the first functional port and the second functional port are respectively connected to the steering cylinder pipeline, and the steering cylinder is used to realize the steering function.

3. The multifunctional hydraulic system of an unmanned transport vehicle according to claim 2, characterized in that: The steering circuit also includes an accumulator and a stop valve. The accumulator is connected to the steering valve block pipeline, and the stop valve is arranged between the accumulator and the steering valve block. The accumulator is used to assist the steering valve block in maintaining pressure, and the stop valve is used to control the opening pressure or pressure relief of the accumulator.

4. The multifunctional hydraulic system of an unmanned transport vehicle according to claim 1, characterized in that: The brake circuit and the auxiliary circuit both include an electromagnetic reversing valve and a mechanical overflow valve. The mechanical overflow valve is arranged between the electromagnetic reversing valve and the connecting pipeline of the hydraulic oil tank. The electromagnetic reversing valve is used to control the action of the functional cylinder so that the cylinder can realize the braking function or the auxiliary function.

5. The multifunctional hydraulic system of an unmanned transport vehicle according to claim 4, characterized in that: The brake circuit includes a service brake circuit and a parking brake circuit; The service brake circuit includes an axle end brake cylinder, which is connected to the electromagnetic reversing valve pipeline, and the electromagnetic reversing valve is used to control the axle end brake cylinder to achieve service braking; The parking brake circuit includes a parking brake cylinder, which is connected to the electromagnetic reversing valve pipeline. The electromagnetic reversing valve is used to control the parking brake cylinder to achieve service braking.

6. The multifunctional hydraulic system of an unmanned transport vehicle according to claim 4, characterized in that: The brake circuit is a power-off brake circuit.

7. The multifunctional hydraulic system of an unmanned transport vehicle according to claim 4, characterized in that: The auxiliary circuit includes a clamping cylinder, which is connected to the electromagnetic reversing valve pipeline. The electromagnetic reversing valve is used to control the clamping cylinder to realize the expansion or closing of the transport bracket.

8. The multifunctional hydraulic system of an unmanned transport vehicle according to claim 1, characterized in that: The pump station also includes a variable displacement piston pump and a remote control valve, wherein the remote control valve is used to receive a control signal to adjust the lift of the variable displacement piston pump.

9. An unmanned transport vehicle, characterized in that: A multifunctional hydraulic system and a pump station bracket of an unmanned transport vehicle comprising any one of claims 1 to 8, wherein the hydraulic oil tank and the hydraulic valve block are respectively arranged on both sides of the pump station bracket.

10. The unmanned transport vehicle according to claim 9, characterized in that: It also includes a frame assembly, and at least part of the connecting pipelines between the pump station and the steering circuit, the brake circuit and the auxiliary circuit are stainless steel pipelines, and at least part of the stainless steel pipelines are arranged outside the frame assembly.

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