One-way confluence hydraulic control system for engineering machinery

Abstract

The invention discloses an engineering machinery one-way confluence hydraulic control system which comprises a hydraulic motor, and the hydraulic motor is in driving connection with a steering brake pump and a working pump at the same time. The steering brake pump is connected with a main oil way, and the working pump is connected with an auxiliary oil way. The main oil way and the auxiliary oil way are connected to a working device in parallel, and the main oil way is connected to the working device and a steering and braking system through a priority valve. A conducting oil way is connected between the main oil way and the auxiliary oil way, a third one-way valve is arranged on the conducting oil way, and the conducting oil way is conducted in the direction from the auxiliary oil way to the main oil way; and the conducting oil path is connected in front of the priority valve. The hydraulic system is suitable for a motor-driven double-pump hydraulic system, the main oil way preferentially supplies braking and steering, the auxiliary oil way serves as supplement, and the system pressure is guaranteed all the time.

Description

Technical Field

[0001] The invention relates to the field of hydraulic energy-saving control of engineering machinery, and in particular to a structure and a control method of a one-way confluence hydraulic system of an electric-controlled engineering machinery. Background Art

[0002] Hydraulic transmission technology has penetrated almost all modern engineering construction fields and is the most important power transmission method in automatic control and engineering machinery actuators. The existing hydraulic system has two basic methods for speed control of actuators. The first is the hydrostatic transmission control method, which adjusts the displacement of the variable pump by changing the speed of the power source and the load pressure to achieve the purpose of adjusting the system flow; the second is the fixed displacement pump plus throttle valve control method, which adjusts the system flow by adjusting the size of the throttle valve orifice.

[0003] In the first method, there is no throttling loss because there is no throttling valve, and the energy efficiency is higher. However, hydrostatic transmission requires the use of a variable pump and a load-sensitive valve, and has very high requirements on the quality of the hydraulic oil. Therefore, the cost of hydrostatic transmission is relatively high and is only used in high-end hydraulic systems.

[0004] The second method is widely used because the cost of the metering pump and throttle valve is not high and it is not sensitive to the quality of the hydraulic oil. In order to increase the efficiency of the hydraulic system, the dual pump (system pump and working pump) merging technology is adopted. When the demand for the steering system is small, the flow of the steering pump is merged to supply the working device. However, in order to ensure that the steering and braking systems are started at any time, the hydraulic system must be kept at idle speed at any time, which causes energy waste in the hydraulic system.

[0005] In order to reduce the energy loss of the hydraulic system at idle speed, an accumulator and its control valve are added in patent CN202311606871.3 (A hydraulic system and energy-saving control method for electric engineering machinery) to ensure that the hydraulic pump and motor are idle and stopped when the system pressure is sufficient. However, the patent does not consider the pressure maintenance of the system when the working device is working, which will cause the system pressure to change with the load when the working device is working, affecting the operation of the steering and braking systems.

[0006] In summary, in a hydraulic system with multiple actuators, the existing method of setting a priority valve and dual pump confluence can partially improve the efficiency of the hydraulic system, but it leads to instability of the system pressure when the working device is working. Although the hydraulic system with an accumulator ensures that the motor is idle and stopped at non-essential times, it does not completely avoid the pressure loss of the system. Summary of the invention

[0007] To this end, the present invention proposes a one-way converging hydraulic control system for engineering machinery. By controlling various valves in the hydraulic system and feeding back the system pressure, the pump and valves are controlled according to the working conditions to achieve system pressure protection and energy saving purposes, giving priority to ensuring the action response of the steering system and the braking system, and then supplying the working device on this basis.

[0008] The technical solution of the present invention is as follows: A one-way confluence hydraulic control system for engineering machinery includes a hydraulic motor, which drives and connects a steering brake pump and a working pump at the same time;

[0009] The steering brake pump is connected to a main oil circuit, and the working pump is connected to a secondary oil circuit;

[0010] The main oil circuit is connected to the working device and the steering and braking systems at the outlet through a priority valve;

[0011] The auxiliary oil circuit and the main oil circuit are connected to the working device in parallel after the priority valve;

[0012] A conducting oil circuit is connected between the main oil circuit and the auxiliary oil circuit. A third one-way valve is arranged on the conducting oil circuit. The third one-way valve conducts in the direction from the auxiliary oil circuit to the main oil circuit and is blocked in the reverse direction. The conducting oil circuit is connected before the priority valve.

[0013] Furthermore: the main oil circuit and the auxiliary oil circuit are connected to the working device through a multi-way reversing valve.

[0014] Furthermore: the hydraulic control system is also provided with an accumulator, the accumulator is connected to the main oil circuit, a switch valve is provided between the accumulator and the main oil circuit, and the switch valve is connected before the priority valve.

[0015] Furthermore: the hydraulic control system is also provided with a relief valve connected between the main oil circuit and the oil tank.

[0016] Furthermore: the hydraulic control system is also provided with a pressure sensor connected to the oil supply pipeline.

[0017] Furthermore: the steering brake pump is first connected to a first one-way valve at the oil outlet end, and then connected to the main oil circuit; the working pump is first connected to a second one-way valve at the oil outlet end, and then connected to the auxiliary oil circuit.

[0018] The present invention provides a one-way valve connected between the working pump and the steering brake pump, so that when the working device is not working and the accumulator pressure is low, the hydraulic oil of the working pump and the steering brake pump can supply the accumulator, steering and braking system requirements. When the working device is working, it is ensured that the steering and braking system pressures will not be affected by the low working device system pressure. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a hydraulic system diagram of the present invention. DETAILED DESCRIPTION

[0020] The technical solution of the present invention is described clearly and completely below in conjunction with the accompanying drawings and embodiments to demonstrate the advantages of no pressure loss along the hydraulic system when it is not working and avoiding overflow loss and pressure loss between valves when it is working.

[0021] like Figure 1 As shown, the present invention provides a one-way confluence hydraulic control system for engineering machinery, comprising a hydraulic motor 1, wherein the hydraulic motor 1 drives and connects a steering brake pump 2 and a working pump 3 simultaneously.

[0022] The steering brake pump 2 has an oil inlet connected to the oil tank and an oil outlet connected to the main oil circuit. Furthermore, the steering brake pump 2 is first connected to a first one-way valve 4 at the oil outlet and then connected to the main oil circuit.

[0023] The working pump 3 is also connected to the oil tank at its oil inlet and to a secondary oil circuit at its oil outlet. The working pump 3 is first connected to a second one-way valve 5 at its oil outlet and then connected to the secondary oil circuit. The first one-way valve 4 and the second one-way valve 5 are used to prevent oil in the oil circuit from flowing back.

[0024] The auxiliary oil circuit is connected to the oil cylinder of the working device in parallel with the main oil circuit; and a conducting oil circuit is horizontally connected between the auxiliary oil circuit and the main oil circuit, and a third one-way valve 6 is connected to the conducting oil circuit. The third one-way valve 6 conducts in the direction from the auxiliary oil circuit to the main oil circuit and is blocked in the reverse direction.

[0025] In addition, a priority valve 7 is arranged on the main oil circuit. The priority valve 7 is a one-inlet and two-outlet valve, wherein the oil inlet is connected to the main oil circuit, one oil outlet is connected to the oil cylinder of the working device, and the other oil outlet is connected to the steering and braking system. The priority valve 7 is arranged at the intersection of the main oil circuit leading to the steering, braking system and the working device, and is preferentially supplied to the steering and braking system. The conducting oil circuit is connected before the priority valve 7.

[0026] Furthermore, a multi-way reversing valve 8 is provided on the oil circuits leading to the working device in parallel with the main oil circuit and the auxiliary oil circuit. Preferably, the multi-way reversing valve is a closed-core control pressure compensation multi-way reversing valve. Both the main oil circuit and the auxiliary oil circuit are connected to the working device through the multi-way reversing valve 8, and in the main oil circuit, the multi-way reversing valve 8 is connected between the priority valve 7 and the working device for adjusting different working states.

[0027] Therefore, it can be seen that in terms of hydraulic supply, the steering brake pump 2 supplies the steering, braking system and working device at the same time in the main oil circuit, and when the steering and braking systems have needs, the steering and braking systems are supplied first through the priority valve 7; the working pump 3 on the auxiliary oil circuit only supplies the working device in principle, but if the pressure in the main oil circuit is insufficient, the auxiliary oil circuit will supplement the main oil circuit through the conducting oil circuit and the third one-way valve 6, thereby ensuring the operation of the steering and braking systems, thereby realizing one-way confluence.

[0028] Furthermore, in the hydraulic control system, an accumulator 9 and a switch valve 10 are also provided; the accumulator 9 is connected to the main oil circuit leading to the steering, braking system and working device, and is used to store energy to ensure the energy supply of the steering and braking systems when the hydraulic pump is not working. The switch valve 10 is connected between the main oil circuit and the accumulator 9, and is used to limit the hydraulic energy storage and supply. The switch valve 10 is connected before the priority valve 7.

[0029] Furthermore, in the hydraulic control system, an electro-hydraulic proportional pilot control valve 11 is also provided, which is connected between the multi-way reversing valve 8 and the vehicle controller 15. The electro-hydraulic proportional pilot control valve 11 is a low-pressure valve, which responds to the instructions of the vehicle controller 15 and is used to start the multi-way reversing valve 8 (high-pressure valve). The two can be integrated components.

[0030] Furthermore, in the hydraulic control system, an overflow valve 12 is also provided, which is connected between the main oil circuit and the oil tank and is used for high-pressure overflow of the system.

[0031] Furthermore, in the hydraulic control system, a pressure sensor 13 is also provided for detecting the pressure of the main oil circuit in real time, and the signal of the pressure sensor 13 is fed back to the vehicle controller 15 .

[0032] Furthermore, the hydraulic control system is operated by an electronically controlled multi-way valve operating handle 14 for state conversion of the working device, and an operating signal of the electronically controlled multi-way valve operating handle 14 is sent to a vehicle controller 15 .

[0033] The hydraulic motor 1 , the switch valve 10 , the electro-hydraulic proportional pilot control valve 11 , the pressure sensor 13 , and the electric-controlled multi-way valve operating handle 14 are all connected to the vehicle controller 15 by signals.

[0034] The vehicle controller 15 controls the speed and torque of the hydraulic motor 1. The vehicle controller 15 receives the signal from the electric multi-way valve operating handle 14, controls the electro-hydraulic proportional pilot control valve 11, and then controls the multi-way reversing valve 8, which is used to switch and adjust the opening of the corresponding valve position of the multi-way reversing valve 8. The vehicle controller 15 receives the pressure signal from the pressure sensor 13, monitors the oil circuit pressure in real time, and determines whether the switch valve 10 is opened, and thus determines whether the accumulator is working.

Claims

1. A one-way confluence hydraulic control system for engineering machinery, characterized in that: It comprises a hydraulic motor (1), wherein the hydraulic motor (1) simultaneously drives a steering brake pump (2) and a working pump (3); The steering brake pump (2) is connected to a main oil circuit, and the working pump (3) is connected to a secondary oil circuit; The main oil line is connected to a priority valve (7), and the priority valve (7) is connected to the working device and the steering and braking systems at the outlet end; The auxiliary oil circuit and the main oil circuit are connected to the working device in parallel after the priority valve (7); A conducting oil circuit is connected between the main oil circuit and the auxiliary oil circuit. A third one-way valve (6) is arranged on the conducting oil circuit. The third one-way valve (6) conducts in the direction from the auxiliary oil circuit to the main oil circuit and is blocked in the reverse direction. The conducting oil circuit is connected before the priority valve (7).

2. The one-way confluence hydraulic control system for engineering machinery according to claim 1, characterized in that: The main oil circuit and the auxiliary oil circuit are connected to the working device through a multi-way reversing valve (8).

3. The one-way confluence hydraulic control system for engineering machinery according to claim 1 or 2, characterized in that: The hydraulic control system is also provided with an accumulator (9), the accumulator (9) is connected to the main oil circuit, a switch valve (10) is provided between the accumulator (9) and the main oil circuit, and the switch valve (10) is connected before the priority valve (7).

4. The one-way confluence hydraulic control system for engineering machinery according to claim 2, characterized in that: The hydraulic control system is also provided with an electro-hydraulic proportional pilot control valve (11), and the electro-hydraulic proportional pilot control valve (11) is connected between the multi-way reversing valve (8) and the vehicle controller (15).

5. The one-way confluence hydraulic control system for engineering machinery according to claim 1, characterized in that: The hydraulic control system is also provided with an overflow valve (12) connected between the main oil circuit and the oil tank.

6. The one-way confluence hydraulic control system for engineering machinery according to claim 1, characterized in that: The hydraulic control system is also provided with a pressure sensor (13) connected to the oil supply pipeline.

7. The one-way confluence hydraulic control system for engineering machinery according to claim 1, characterized in that: The steering brake pump (2) is first connected to a first one-way valve (4) at the oil outlet end and then connected to the main oil circuit; The working pump (3) is first connected to a second one-way valve (5) at the oil outlet end and then connected to the auxiliary oil circuit.

Images