Hydraulic control system for body lift

Abstract

The utility model discloses a kind of vehicle body lifting hydraulic control system, including several action units, flow control unit, oil pump and controller, oil tank is connected to oil pump, motor is connected on oil pump, action unit, flow control unit, motor connection controller, each action unit is provided with double-acting oil cylinder, piston and piston rod are arranged in double-acting oil cylinder, the rod cavity and the rod cavity without of double-acting oil cylinder are communicated by closed loop;Flow control unit is respectively set flow control valve corresponding each action unit, the closed loop of the oil outlet action unit of flow control valve, the oil inlet of flow control valve is connected with oil pump by oil conveying path, the oil return port of flow control valve is connected oil tank by oil return path.The utility model's flow control unit realizes oil liquid two-way control by two-way proportional flow control valve, system is simple, low in cost, easy to realize synchronous control, two-way flow consistency is high, guarantee dynamic response synchronization, avoid appearing dynamic response lag situation.

Description

Technical Field

[0001] This utility model relates to the field of automotive body lifting control technology, and in particular to a hydraulic control system for vehicle body lifting. Background Technology

[0002] With the continuous innovation of intelligent vehicle technology, most existing intelligent vehicles are not equipped with a hydraulic body lifting system, resulting in a fixed chassis height. This design limitation makes it difficult for vehicles to adjust their height to adapt to environmental needs when facing complex road conditions. For example, when a car is parked on an uneven road surface, a traditional fixed-height chassis cannot adjust its posture autonomously, making it inconvenient for passengers to enter and exit the vehicle.

[0003] Patent CN218858093U (application number CN202223214801.7) discloses a hydraulic lifting suspension system, which connects the shock absorber group and the hydraulic pump assembly through a lifting control valve assembly, so that the hydraulic pump assembly can supply oil to the shock absorber group or absorb the oil returning from the shock absorber group, thereby realizing the lifting of the shock absorber group to achieve the lifting of the vehicle. This hydraulic lifting suspension system has the following problems: (1) Its accumulator is surrounded by the outer wall of the corresponding shock absorber or is set with a gap between it and the corresponding shock absorber, so that the distance between the accumulator and the corresponding shock absorber is relatively close to improve the integration. This design will generate pressure fluctuations during dynamic adjustment, and the pressure fluctuations will cause the hydraulic components to bear periodic alternating loads, resulting in premature wear of seals, moving parts, etc.; (2) Its lifting control valve assembly needs to achieve bidirectional flow control through a combination of multiple valves, which is not only complex and costly, but also difficult to achieve synchronous control. When the multi-valve combination is controlled, the consistency of bidirectional flow is poor and the dynamic response is lagging. Utility Model Content

[0004] In response to the shortcomings of existing hydraulic lifting suspension systems, the applicant provides a reasonably structured hydraulic control system for vehicle body lifting, which reduces pressure fluctuations during dynamic adjustment, avoids premature wear of seals and moving parts, improves the consistency of bidirectional flow control, and avoids dynamic response lag.

[0005] The technical solution adopted in this utility model is as follows:

[0006] A vehicle body lifting hydraulic control system includes several actuation units, a flow control unit, an oil pump, and a controller. The oil pump is connected to an oil tank and a motor is connected to the oil pump. The actuation units, flow control unit, and motor are connected to the controller. Each actuation unit is equipped with a double-acting cylinder. The double-acting cylinder contains a piston and a piston rod. The piston divides the inner cavity of the double-acting cylinder into a rod chamber and a rodless chamber. The piston rod is located in the rod chamber and extends from the top of the double-acting cylinder to connect to the vehicle body. The rod chamber and rodless chamber of the double-acting cylinder are connected through a closed loop. The flow control unit is equipped with a flow control valve for each actuation unit. The outlet of the flow control valve is connected to the closed loop of the actuation unit. The inlet of the flow control valve is connected to the oil pump through an oil supply line. The return port of the flow control valve is connected to the oil tank through a return line.

[0007] As a further improvement to the above technical solution:

[0008] The flow control valve is a bidirectional proportional flow valve.

[0009] An accumulator is connected to the closed circuit of the double-acting hydraulic cylinder. A check valve and a throttle valve are connected in parallel between the accumulator and the rod chamber and rodless chamber, respectively. The oil inlet of the check valve is connected to the accumulator and the oil outlet is connected to the rod chamber / rodless chamber.

[0010] Each double-acting cylinder has a helical spring attached to its piston rod.

[0011] Each double-acting cylinder has a height sensor connected to its piston rod. The height sensor can detect the vehicle's height from the ground in real time and feed the data signal back to the controller. The height sensor is located on the outside of the coil spring.

[0012] Each double-acting cylinder is equipped with a pressure sensor.

[0013] A second check valve is installed on the oil pipeline. The inlet of the second check valve is connected to the oil pump, and the outlet is connected to the flow control valve.

[0014] A switch valve is installed on the return oil line.

[0015] An overflow circuit is connected between the oil supply circuit and the return circuit, and an overflow valve is installed on the overflow circuit.

[0016] The connection point between the overflow circuit and the oil supply circuit is located before the oil inlet of the second check valve, and the connection point between the overflow circuit and the return oil circuit is located after the oil outlet of the switching valve.

[0017] The beneficial effects of this utility model are as follows:

[0018] The flow control unit of this invention achieves bidirectional control of oil through a bidirectional proportional flow control valve. The system is simple, low-cost, easy to achieve synchronous control, and has high bidirectional flow consistency, ensuring synchronous dynamic response and avoiding dynamic response lag.

[0019] The present invention has a one-way throttle valve between the two-way action cylinder and the accumulator. The accumulator absorbs the pressure fluctuations of the closed circuit through the one-way throttle valve, which stabilizes the working performance of the hydraulic system. On the one hand, it reduces the pressure fluctuations during dynamic adjustment, avoids the hydraulic components from bearing periodic alternating loads due to pressure fluctuations, and avoids premature wear of seals, moving parts, etc. On the other hand, it makes the vehicle height adjustment process more stable and smooth, effectively alleviating the jerking sensation that may occur when adjusting the vehicle height.

[0020] The solenoid spring and accumulator of the actuating unit of this invention form a composite stiffness system, which allows the piston rod of the actuating unit to extend and retract flexibly and freely, and also effectively reduces the response time and power consumption of the hydraulic system. Constant stiffness and variable stiffness are achieved through matching values ​​to realize comprehensive stiffness characteristics that can adapt to system requirements. Adjusting the load distribution ratio between the solenoid spring and the accumulator allows for a wider range of stiffness adjustment; for example, a 50% load distribution between the solenoid spring and the accumulator versus a 40% load distribution with the solenoid spring and a 60% load distribution will result in different stiffness adjustment ranges. Various combinations of the distribution ratios are available to suit different stiffness adjustment bandwidths.

[0021] The height sensor of the actuation unit of this utility model can detect the height of the vehicle body from the ground in real time and feed the data signal back to the controller. The controller can accurately adjust the flow control unit according to the data signal to ensure that the actuation units can work together under different load conditions, maintain the synchronization of the vehicle body's lifting height, thereby keeping the vehicle body always in a level state, improving ride comfort and enhancing vehicle driving safety. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the system of this utility model.

[0023] Figure 2 This is a schematic diagram of the double-acting hydraulic cylinder unit of this utility model.

[0024] In the picture:

[0025] 1. Actuating unit; 11. Double-acting cylinder; 111. Piston; 112. Piston rod; 113. Rod chamber; 114. Rodless chamber; 12. Accumulator; 13. Spring; 14. Check valve one; 15. Throttle valve; 16. Height sensor;

[0026] 2. Flow control unit; 21. Flow control valve; 22. Check valve II; 23. On / off valve; 24. Relief valve;

[0027] 3. Fuel tank;

[0028] 4. Oil pump; 41. Motor

[0029] 5. Controller;

[0030] 10. Closed loop; 20. Oil delivery loop; 30. Oil return loop; 40. Overflow loop. Detailed Implementation

[0031] The specific embodiments of this utility model are described below with reference to the accompanying drawings.

[0032] like Figure 1 As shown, the vehicle body lifting hydraulic control system of this utility model is provided with several action units 1, flow control unit 2, oil tank 3, oil pump 4 and controller 5. Each action unit 1 is connected to the oil tank 3 and the oil pump 4 through the flow control unit 2. The oil pump 4 is connected to the oil tank 3. The oil pump 4 is connected to a motor 41 and driven by the motor 41. The action unit 1, the flow control unit 2 and the motor 41 are respectively connected to the controller 5.

[0033] like Figure 1 , Figure 2As shown, each actuation unit 1 is equipped with a double-acting hydraulic cylinder 11, an energy accumulator 12, a coil spring 13, and a height sensor 16. The double-acting hydraulic cylinder 11 is arranged vertically, and a piston 111 is installed inside the double-acting hydraulic cylinder 11. A piston rod 112 is connected to the piston 111. The piston 111 divides the inner cavity of the double-acting hydraulic cylinder 11 into an upper rod chamber 113 and a lower rodless chamber 114. The piston rod 112 is located in the rod chamber 113 and extends from the top of the double-acting hydraulic cylinder 11 to connect to the vehicle body. The rod chamber 113 and the rodless chamber 114 of the double-acting hydraulic cylinder 11 are interconnected through pipelines to form a closed loop 10. The accumulator 12 is connected in the closed loop 10. A one-way valve 14 and a throttle valve 15 are connected in parallel between the accumulator 12, the rod chamber 113, and the rodless chamber 114, respectively. The inlet of the one-way valve 14 is connected to the accumulator 12, and the outlet is connected to the rod chamber 113 / rodless chamber 114. The one-way valve 14 and the throttle valve 15 together form a one-way throttle valve. The accumulator 12 absorbs pressure fluctuations in the closed loop 10 through the one-way throttle valve, stabilizing the working performance of the hydraulic system. On the one hand, this reduces pressure fluctuations during dynamic adjustment, preventing hydraulic components from bearing periodic alternating loads due to pressure fluctuations, and avoiding premature wear of seals and moving parts. On the other hand, it makes the vehicle height adjustment process smoother and more stable, effectively alleviating the jerking sensation that may occur during vehicle height adjustment. The coil spring 13 and the height sensor 16 are connected to the piston rod 112 of the double-acting cylinder 11. The height sensor 16 is located outside the coil spring 13. The spring 13, in conjunction with the energy storage device 12, forms a composite stiffness system, allowing the piston rod 112 to extend and retract freely and effectively reducing the response time and power consumption of the hydraulic system. The height sensor 16 can detect the vehicle's height from the ground in real time and feed the data signal back to the controller 5. The controller 5 can precisely adjust the flow control unit 2 based on the data signal, ensuring that all actuating units 1 can work collaboratively under different load conditions, maintaining the synchronization of vehicle height increase and decrease, thereby keeping the vehicle level, improving ride comfort, and enhancing vehicle driving safety. A pressure sensor (not shown in the figure) is installed inside the double-acting cylinder 11 to monitor the pressure in the rod chamber 113 and the rodless chamber 114 in real time.

[0034] like Figure 1As shown, the flow control unit 2 is equipped with several flow control valves 21 corresponding to several action units 1. The oil outlet of one flow control valve 21 is connected to the closed loop 10 of one action unit 1. The oil inlets of several flow control valves 21 are connected to an oil pump 4 through an oil supply line 20. A check valve 22 is installed on the oil supply line 20. The oil inlet of the check valve 22 is connected to the oil pump 4, and the oil outlet is connected to the flow control valve 21. The check valve 22 restricts the high-pressure oil from the oil pump 4 to the flow control valve 21 in one direction through the oil supply line 20, preventing the oil from flowing back from the oil supply line 20 and causing system pressure imbalance. The oil return ports of several flow control valves 21 are connected to an oil tank 3 through a return oil line 30. A switch valve 23 is installed on the return oil line 30. The oil returning from the action unit 1 flows back to the oil tank 3 through the flow control valves 21 and the switch valve 23. An overflow circuit 40 connects the oil supply circuit 20 and the return circuit 30. The connection point of the overflow circuit 40 and the oil supply circuit 20 is located before the oil inlet of the one-way valve 22, and the connection point of the overflow circuit 40 and the return circuit 30 is located after the oil outlet of the switching valve 23. An overflow valve 24 is installed on the overflow circuit 40. The flow control valve 21 is a bidirectional proportional flow valve. When the system is static, it can cut off the oil circuit to achieve the sealing and pressure holding of the closed circuit 10 of a single action unit 1. This helps to prevent oil leakage between action units 1 when the vehicle body is passively raised or lowered, and helps to maintain the vehicle body level. When the vehicle body needs to be lowered, the controller 5 can control the flow control valve 21 to switch to the return oil mode. The hydraulic oil of the action unit 1 flows back to the oil tank 3 through the flow control valve 21 and the open switching valve 23. The flow control unit 2 achieves bidirectional oil control through the bidirectional proportional flow control valve 21. The system is simple, low-cost, easy to achieve synchronous control, and has high bidirectional flow consistency, ensuring synchronous dynamic response and avoiding dynamic response lag.

[0035] The vehicle body lifting hydraulic control system of this utility model has two modes: active and passive.

[0036] In active mode, the flow control valve 21 opens, and the motor 41 drives the oil pump 4 to work, allowing oil to flow between the oil tank 3, the flow control unit 2, and the action unit 1. This pushes the piston 111 and piston rod 112 of the action unit 1 to extend or retract, thus raising or lowering the vehicle body. When the vehicle body needs to be raised, the oil pump 4 outputs oil from the oil tank 3. The high-pressure oil output passes through the check valve 22 and enters the flow control valve 21, then flows into the rodless chamber 114 of the double-acting cylinder 11, pushing the piston 111 and piston rod 112 upward. At the same time, the hydraulic oil in the rod chamber 113 flows back to the rodless chamber 114 through the closed circuit 10, forming an auxiliary thrust to accelerate the lifting of the vehicle body. When the vehicle body descends, the hydraulic oil pressure in the rod chamber 113 of the double-acting cylinder 11 increases, pushing the piston rod 112 and piston 111 downward. Part of the hydraulic oil in the rodless chamber 114 flows back to the rod chamber 113 through the closed circuit 10 to assist in the descent, while the other part of the hydraulic oil flows back to the oil tank 3 through the flow control valve 21 and the switching valve 23, completing the pressure relief process.

[0037] In passive mode, flow control valve 21 is closed, and the closed loop 10 of the single action unit 1 is sealed and pressurized. The oil in the accumulator 12 enters the double-acting cylinder 11 through the closed loop 10, participating in the lifting and lowering control of piston 111 and piston rod 112 to achieve the lifting and lowering of the vehicle body. When the vehicle body needs to be raised, the oil in the accumulator 12 flows into the rodless chamber 114 of the double-acting cylinder 11 through the one-way throttle valve, pushing piston 111 and piston rod 112 upward. At the same time, the hydraulic oil in the rod chamber 113 flows back to the rodless chamber 114 through the closed loop 10, forming an auxiliary thrust to lift the vehicle body. When the vehicle body is lowered, the hydraulic oil pressure in the rod chamber 113 of the double-acting cylinder 11 increases, pushing piston rod 112 and piston 111 downward. Part of the hydraulic oil in the rodless chamber 114 flows back to the rod chamber 113 through the closed loop 10 to assist in pushing the descent, and the other part of the hydraulic oil flows back to the accumulator 12 through the one-way throttle valve to complete the pressure relief process.

[0038] The above description is an explanation of the present utility model and not a limitation thereof. The present utility model can be modified in any form without departing from its spirit.

Claims

1. A vehicle body lifting hydraulic control system, comprising several action units (1), a flow control unit (2), an oil pump (4), and a controller (5), wherein the oil pump (4) is connected to an oil tank (3), and a motor (41) is connected to the oil pump (4), and the action units (1), the flow control unit (2), and the motor (41) are connected to the controller (5), characterized in that: Each action unit (1) is equipped with a double-acting cylinder (11). The double-acting cylinder (11) is equipped with a piston (111) and a piston rod (112). The piston (111) divides the inner cavity of the double-acting cylinder (11) into a rod chamber (113) and a rodless chamber (114). The piston rod (112) is located in the rod chamber (113) and extends from the top of the double-acting cylinder (11) to connect to the vehicle body. The rod chamber (113) and the rodless chamber (114) of the double-acting cylinder (11) are connected through a closed circuit (10). The flow control unit (2) is equipped with a flow control valve (21) for each action unit (1). The outlet of the flow control valve (21) is connected to the closed circuit (10) of the action unit (1). The inlet of the flow control valve (21) is connected to the oil pump (4) through the oil supply line (20). The return port of the flow control valve (21) is connected to the oil tank (3) through the return oil line (30).

2. The hydraulic control system for a body lift according to claim 1, characterized in that: The flow control valve (21) is a bidirectional proportional flow valve.

3. The hydraulic control system for a body lift according to claim 1, wherein: An energy storage device (12) is connected to the closed circuit (10) of the double-acting cylinder (11). A one-way valve (14) and a throttle valve (15) are respectively connected in parallel between the energy storage device (12), the rod chamber (113), and the rodless chamber (114). The oil inlet of the one-way valve (14) is connected to the energy storage device (12), and the oil outlet is connected to the rod chamber (113) / rodless chamber (114).

4. The hydraulic control system for a body lift according to claim 1, characterized in that: Each double-acting cylinder (11) has a helical spring (13) attached to its piston rod (112).

5. The hydraulic control system for a body lift according to claim 1, wherein: Each double-acting cylinder (11) has a height sensor (16) connected to its piston rod (112). The height sensor (16) can detect the height of the vehicle body from the ground in real time and feed the data signal back to the controller (5). The height sensor (16) is located on the outside of the coil spring (13).

6. The hydraulic control system for a body lift according to claim 1, wherein: Each double-acting cylinder (11) is equipped with a pressure sensor.

7. The hydraulic control system for a body lift according to claim 1, wherein: A check valve (22) is installed on the oil supply line (20). The oil inlet of the check valve (22) is connected to the oil pump (4), and the oil outlet is connected to the flow control valve (21).

8. The hydraulic control system for a body lift according to claim 1, wherein: A switch valve (23) is installed on the return oil line (30).

9. The hydraulic control system for a body lift according to claim 1, wherein: An overflow circuit (40) is connected between the oil supply circuit (20) and the return oil circuit (30), and an overflow valve (24) is installed on the overflow circuit (40).

10. The hydraulic control system for a body lift according to claim 9, characterized in that: The connection point between the overflow circuit (40) and the oil supply circuit (20) is located before the oil inlet of the check valve (22), and the connection point between the overflow circuit (40) and the return oil circuit (30) is located after the oil outlet of the switch valve (23).

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