Dual-mode flow distribution control valve and load sensitive system

Abstract

The invention relates to the technical field of hydraulic systems, in particular to a dual-mode flow distribution control valve and a load-sensitive system.The dual-mode flow distribution control valve comprises an LS pressure relief control valve, a first shuttle valve, a second shuttle valve, a load-sensitive valve, a small-flow flush valve, a fixed differential pressure reducing valve and a switching valve; a lower end signal input port of the first shuttle valve is connected with an inlet of the small-flow flush valve and an outlet oil way of the fixed differential pressure reducing valve, a right end signal output port is connected with a signal port K3 oil way, and a left end signal output port is selectively connected with a load sensitive valve spring control end oil way or a lower end signal input port oil way of the third shuttle valve. By introducing the dual-mode flow distribution control valve, the system can switch working modes according to different working conditions, so that flow distribution is optimized, unnecessary energy loss is reduced, the flow distribution is automatically adjusted according to different loads and driving working conditions of wheels, and the flow distribution efficiency is improved. And the problems of power parasitism, wheel slipping and the like of a traditional load-sensitive system under different working conditions are avoided.

Description

Technical Field

[0001] This invention relates to the field of hydraulic system technology, specifically to a dual-mode flow distribution control valve and load-sensitive system. Background Technology

[0002] The load-sensitive system consists of a load-sensitive pump and a multi-way directional valve with compensation function. It was developed based on improved load sensing technology and solved the problem of flow distribution to each actuator in a single-pump-source multi-actuator system due to different working loads. It ensures that the flow of each actuator is linearly related only to the opening area of ​​the directional valve in that line. Moreover, the output flow of the load-sensitive pump automatically adapts to the total demand flow without overflow. It is often used in the hydraulic systems of engineering machinery working devices.

[0003] Currently, when existing load-sensitive systems are used in vehicle driving systems, the complex road conditions, uneven surfaces, and varying wheel load distribution make wheel size unpredictable. If the vehicle always uses the reversing valve orifice area compensation method for flow distribution, power parasitism, wheel slippage and wear, and low energy utilization often occur. In order to overcome the shortcomings of existing load-sensitive systems and broaden their application scope, a dual-mode flow distribution control valve and load-sensitive system are proposed. Summary of the Invention

[0004] To achieve the above objectives, the present invention provides the following technical solution: a dual-mode flow distribution control valve, comprising an LS pressure relief control valve, a first shuttle valve, a second shuttle valve, a load-sensitive valve, a small-flow flushing valve, a differential pressure reducing valve, and a switching valve; when used to control a load-sensitive system of two multi-way valves, it further comprises a third shuttle valve and a flow priority valve, wherein: The inlet of the LS pressure relief control valve is connected to the upper signal input port and signal port X1 oil circuit of the first shuttle valve, respectively, and the outlet is connected to the oil tank. The lower signal input port of the first shuttle valve is connected to the inlet of the small flow flushing valve and the outlet oil circuit of the constant differential pressure reducing valve, respectively. The right signal output port is connected to the oil circuit of signal port K3. The left signal output port is selectively connected to the oil circuit of the load sensitive valve spring control end or the oil circuit of the lower signal input port of the third shuttle valve. The upper signal input port of the second shuttle valve is connected to the oil circuit of the output port of the load-sensitive valve, the lower signal port is connected to the oil circuit of signal port K1, and the signal output port is connected to the oil circuit of signal port K2. The outlet of the low-flow flushing valve is connected back to the oil tank; The oil inlet of the switching valve is connected to the signal input port Pi oil circuit, the oil return port is connected to the oil tank, one of its working ports is connected to the oil inlet of the load sensitive valve and the springless control end respectively, and the other working oil port is connected to the inlet of the differential pressure reducing valve. The signal output port of the third shuttle valve is connected to the oil circuit of the spring control end of the load-sensitive valve. The flow priority valve is provided with an input port P connected to the main oil circuit, a main flow priority output port CF, a main flow excess output port EF, and a signal input port X2. The signal input port X2 is also connected to the upper signal input port oil circuit of the third shuttle valve.

[0005] Preferably, the LS pressure relief control valve is equipped with an electromagnet, which energizes or de-energizes the electromagnet to switch the valve core direction, thereby controlling the on / off state of the signal port X1 oil circuit and the oil tank; the switching valve is also equipped with an electromagnet, which energizes or de-energizes the electromagnet to switch the working port connection relationship, thereby achieving selective connection between the signal input port Pi oil circuit and the oil inlet of the load sensitive valve or the inlet of the differential pressure reducing valve.

[0006] Preferably, the spring adjustment pressure of the differential pressure reducing valve is consistent with the spring adjustment pressure of the load sensitive valve, and the adjustment pressure range is set to 1.6MPa~2MPa, so as to ensure that the pressure oil after pressure reduction acts stably on the lower end signal input port of the first shuttle valve.

[0007] Preferably, the overflow rate of the low-flow flushing valve is set to a low-flow level, which is used to maintain the normal pressure reducing function of the differential pressure reducing valve when the spring chamber of the pressure compensation valve is full of control oil, and to limit the flow waste caused by excessive flow through the differential pressure reducing valve.

[0008] Preferably, the flow priority valve is equipped with a compensation spring. The valve core is switched by the pressure difference between the compensation spring pressure and the signal input port X2, thereby controlling the on / off relationship between the input port P and the main flow priority output port CF and the main flow excess output port EF, so as to realize the priority distribution of flow.

[0009] A load-sensitive system, specifically a single-way multi-way valve load-sensitive system, includes the aforementioned dual-mode flow distribution control valve, an inverse proportional displacement pump, and a downstream compensating multi-way valve, wherein: The inverse proportional displacement pump includes an electro-proportional displacement control valve and a displacement control oil circuit. The oil inlet is connected to the oil tank, and the output is connected to the oil inlet PA of the downstream compensation multi-way valve and the signal input port Pi of the dual-mode flow distribution control valve, respectively. The pressure compensation valve spring chamber signal control port of the downstream compensation multi-way valve is not directly connected to its own LS oil circuit, and each reversing valve is connected to the actuator travel drive motor. The signal port K1 of the dual-mode flow distribution control valve is connected to the signal external interface oil circuit of the electro-proportional displacement control valve, the signal port K2 is connected to the displacement control oil circuit of the inverse proportional displacement pump, the signal port K3 is connected to the signal control oil circuit of the pressure compensation valve spring chamber of the downstream compensation multi-way valve, and the signal port X1 is connected to the LS oil circuit of the downstream compensation multi-way valve.

[0010] Preferably, the downstream compensation multi-way valve is equipped with a small flow flushing valve. When the downstream compensation multi-way valve is not operated, its LS oil route is depressurized by the small flow flushing valve, thereby releasing the pressure at the spring control end of the load-sensitive valve in the dual-mode flow distribution control valve, and realizing the spool reversal of the load-sensitive valve.

[0011] A load-sensitive system, a dual multi-way valve load-sensitive system, includes the aforementioned dual-mode flow distribution control valve, an inverse proportional displacement pump, a downstream compensating multi-way valve, and a downstream compensating multi-way valve, wherein: The inlet of the inverse proportional displacement pump is connected to the oil tank, and the output port is connected to the oil circuit of the input port P and signal input port Pi of the dual-mode flow distribution control valve, respectively. Each of the reversing valves of the downstream compensating multi-way valve is connected to the actuator travel drive motor, and the downstream compensating multi-way valve is connected to other actuators except for the actuator travel drive motor. The signal ports K1, K2, K3, and X1 of the dual-mode flow distribution control valve are connected in the same way as the inverse proportional displacement pump, the downstream compensation multi-way valve, and the single multi-way valve load-sensitive system. The signal port X2 of the dual-mode flow distribution control valve is connected to the LS oil circuit of the downstream compensation multi-way valve, the main flow priority output port CF is connected to the main oil port PB oil circuit of the downstream compensation multi-way valve, and the main flow excess output port EF is connected to the main oil port PA oil circuit of the downstream compensation multi-way valve.

[0012] Preferably, the downstream compensation multi-way valve is also equipped with a small flow flushing valve. When the downstream compensation multi-way valve is not operated, its LS oil route is depressurized by the small flow flushing valve, which releases the pressure at the signal input port X2 of the flow priority valve in the dual-mode flow distribution control valve, thereby driving the valve core of the flow priority valve to switch to the lower position, so that all the pressure oil output by the inverse proportional displacement pump flows into the downstream compensation multi-way valve through the main flow exceeding the output port EF.

[0013] Compared with the prior art, the beneficial effects of the present invention are: (1) By introducing a dual-mode flow distribution control valve, the system can switch working modes according to different working conditions to optimize flow distribution and reduce unnecessary energy loss. By automatically adjusting the flow distribution according to different wheel loads and driving conditions, the system avoids problems such as power parasitism and wheel slippage that may occur in traditional load-sensitive systems under different working conditions. (2) By adding a differential pressure reducing valve and a small flow flushing valve, the present invention ensures the stability of the system under various working conditions. Especially under conditions of large load changes, it can maintain stable oil pressure and flow control. By using a flow priority valve and an inverse proportional displacement pump, the precise control of flow distribution and oil pressure is improved, so that the system can be flexibly adjusted according to the needs and energy waste is avoided. Attached Figure Description

[0014] Figure 1 This is a first schematic diagram of a control valve for dual-mode flow distribution in one embodiment of the present invention; Figure 2 This is a second schematic diagram of a control valve for dual-mode flow distribution in one embodiment of the present invention; Figure 3 This is a schematic diagram of a single-way valve load-sensitive system according to an embodiment of the present invention; Figure 4 This is a schematic diagram of a dual multi-way valve load-sensitive system according to an embodiment of the present invention.

[0015] In the diagram: 1. Dual-mode flow distribution control valve; 1.1. LS pressure relief control valve; 1.2. First shuttle valve; 1.3. Second shuttle valve; 1.4. Load-sensitive valve; 1.5. Small flow flushing valve; 1.6. Differential pressure reducing valve; 1.7. Switching valve; 1.8. Third shuttle valve; 1.9. Flow priority valve; 2. Inverse proportional displacement pump; 2.1. Electro-proportional displacement control valve; 3. Post-valve compensation multi-way valve; 4. Post-valve compensation multi-way valve. Detailed Implementation

[0016] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0017] Example 1, please refer to Figure 1 and Figure 2 This invention provides a technical solution: a dual-mode flow distribution control valve, comprising an LS pressure relief control valve 1.1, a first shuttle valve 1.2, a second shuttle valve 1.3, a load-sensitive valve 1.4, a small-flow flushing valve 1.5, a differential pressure reducing valve 1.6, and a switching valve 1.7. When used to control a load-sensitive system with two multi-way valves, it further comprises a third shuttle valve 1.8 and a flow priority valve 1.9, wherein: The inlet of the LS pressure relief control valve 1.1 is connected to the upper signal input port and signal port X1 oil circuit of the first shuttle valve 1.2, and the outlet is connected to the oil tank. The lower signal input port of the first shuttle valve 1.2 is connected to the inlet of the small flow flushing valve 1.5 and the outlet oil circuit of the differential pressure reducing valve 1.6 respectively. The right signal output port is connected to the signal port K3 oil circuit. The left signal output port is selectively connected to the spring control end oil circuit of the load sensitive valve 1.4 or the lower signal input port oil circuit of the third shuttle valve 1.8. The upper signal input port of the second shuttle valve 1.3 is connected to the oil circuit of the output port of the load-sensitive valve 1.4, the lower signal port is connected to the oil circuit of signal port K1, and the signal output port is connected to the oil circuit of signal port K2. The outlet of the small flow flushing valve 1.5 is connected back to the oil tank; The oil inlet of the switching valve 1.7 is connected to the signal input port Pi oil circuit, and the oil return port is connected to the oil tank. One of its working ports is connected to the oil inlet of the load-sensitive valve 1.4 and the springless control end, respectively, and the other working port is connected to the inlet of the differential pressure reducing valve 1.6. The signal output port of the third shuttle valve 1.8 is connected to the oil circuit of the spring control end of the load-sensitive valve 1.4; The flow priority valve 1.9 is equipped with an input port P connected to the main oil circuit, a main flow priority output port CF, a main flow excess output port EF, and a signal input port X2. The signal input port X2 is also connected to the upper signal input port oil circuit of the third shuttle valve 1.8.

[0018] It should be noted that the inlet of the LS pressure relief control valve 1.1 is connected to the upper signal input port of the first shuttle valve 1.2 to receive signals to control the pressure of the hydraulic system; the valve outlet is connected to the oil tank, mainly for pressure relief to maintain system stability; the upper signal input port receives the signal input from the LS pressure relief control valve 1.1 to control the flow switching and regulation; the lower signal input port is connected to the inlet of the small flow flushing valve 1.5 and the outlet oil circuit of the differential pressure reducing valve 1.6 to regulate the flow and pressure of the hydraulic system and ensure the stability of the oil flow direction and pressure in the system; the right signal output port is connected to signal port K3 for outputting signals; the left signal output port can be selectively connected to the spring control end oil circuit of the load-sensitive valve 1.4 or the signal input port of the third shuttle valve 1.8 for further signal regulation and control; the upper signal input port of the second shuttle valve 1.3 is connected to the output port of the load-sensitive valve 1.4 to control the response of the load-sensitive system; the lower signal port is connected to signal port K1 to receive signals from the system for regulating the lower control; the signal output port is connected to signal port K2. Used to output signals to other hydraulic components; the outlet of the small-flow flushing valve 1.5 is connected back to the oil tank, its main function is to control the small flow of flushing oil, ensure the cleanliness of the system, avoid contamination, and prevent valve jamming; the inlet of the switching valve 1.7 is connected to the signal input port Pi, the switching valve 1.7 is used to control the flow direction of hydraulic fluid, and the signal input port receives control signals from the system; the return port of the switching valve 1.7 is connected to the oil tank to remove excess fluid; the working port is connected to the load-sensitive valve 1.4 and the differential pressure reducing valve 1.6 to provide switching between different flow channels and optimize the working efficiency of the hydraulic system; the signal output port of the third shuttle valve 1.8 is connected to the load-sensitive valve 1.4 through the spring control end to adjust the pressure response of the system; the flow priority valve 1.9 is used to ensure the flow distribution in the hydraulic system, the input port P is connected to the main oil circuit, and the output port CF provides the main flow priority output; when the flow exceeds the preset value, it is output through the excess output port EF to maintain the stability of the system pressure; the signal input port X2 is connected to the upper signal input port of the third shuttle valve 1.8 for fine adjustment of the system flow and pressure.

[0019] In an optional embodiment, the LS pressure relief control valve 1.1 is equipped with an electromagnet, which energizes or de-energizes the valve core to switch the direction of the valve core, thereby controlling the on / off state of the signal port X1 oil circuit and the oil tank; the switching valve 1.7 is also equipped with an electromagnet, which energizes or de-energizes the working port connection relationship to achieve selective connection between the signal input port Pi oil circuit and the oil inlet of the load sensitive valve 1.4 or the inlet of the differential pressure reducing valve 1.6.

[0020] It should be noted that the valve core of the LS pressure relief control valve 1.1 can switch directions when the electromagnet is energized or de-energized. When energized: the electromagnet engages, the valve core moves, and the signal port X1 oil circuit may be connected or disconnected from the oil tank, thus altering the transmission of the system pressure signal. When de-energized: the electromagnet releases, the valve core resets, the path of the signal port X1 oil circuit changes, and the system pressure is adjusted to another state. By controlling the valve core position, on / off control of the hydraulic system pressure is achieved, allowing the system to automatically adjust according to external control signals. The electromagnet controls the path of the switching valve 1.7's working port, enabling selective connection of the signal oil circuit. When energized: the working port may connect the signal input port Pi oil circuit to the inlet of the load-sensitive valve 1.4, allowing the main system flow to directly control the load-sensitive valve 1.4. When de-energized: the working port resets, connecting the signal input port Pi oil circuit to the inlet of the differential pressure reducing valve 1.6, achieving system pressure diversion and regulation. This ensures that the hydraulic system can flexibly switch control modes under different operating conditions, such as flow and pressure optimization under high or low load conditions.

[0021] In an optional embodiment, the spring adjustment pressure of the differential pressure reducing valve 1.6 is consistent with the spring adjustment pressure of the load sensitive valve 1.4, and the adjustment pressure range is set to 1.6MPa~2MPa, so as to ensure that the pressure oil after pressure reduction acts stably on the lower signal input port of the first shuttle valve 1.2.

[0022] It should be noted that the main function of the differential pressure reducing valve 1.6 is to maintain the pressure-reducing oil in the hydraulic system within a preset pressure range by adjusting the spring tension, ensuring that the system can operate stably under specific pressures. When pressurized oil enters the differential pressure reducing valve 1.6, the spring adjustment device automatically adjusts the valve opening and closing according to the preset pressure, ensuring that the pressure of the oil flow after pressure reduction meets the set standard. The spring adjustment pressure range of the differential pressure reducing valve 1.6 is set to 1.6MPa~2MPa, which means that the pressure-reducing oil in the system will remain stable within this range. If the system pressure exceeds 2MPa, the pressure reducing valve will automatically adjust to ensure that the system pressure is not too high, avoiding damage to other components. The load-sensitive valve 1.4 is responsible for automatically adjusting the flow rate according to changes in load, ensuring that the hydraulic system can provide the appropriate flow rate as needed. The load-sensitive valve 1.4 also has a spring adjustment device, which dynamically adjusts the pressure and flow rate according to changes in load, ensuring that the system can operate stably under different load conditions. Under these conditions, it can provide appropriate power; the spring adjustment pressure of the load-sensitive valve 1.4 is consistent with the pressure of the differential pressure reducing valve 1.6, meaning that the adjustment pressure of both is within the same pressure range, ensuring that the hydraulic system maintains a stable pressure output under various working conditions; the consistent spring adjustment pressure of the differential pressure reducing valve 1.6 and the load-sensitive valve 1.4 ensures the following aspects: Stability: Through the same pressure adjustment range, the stability of the hydraulic system is guaranteed, especially when the pressure oil flows from the pressure reducing valve to the lower signal input port of the first shuttle valve 1.2, the system can ensure a stable oil supply to the signal oil circuit; Flow and pressure coordination: When the system load changes, the load-sensitive valve 1.4 can adjust the flow according to the real-time demand, while the pressure reducing valve ensures that the oil pressure is within the appropriate range, avoiding the impact of excessive or insufficient pressure on the system; Avoidance of shock: The two working together can balance the system pressure and avoid hydraulic system shock caused by unstable oil flow or excessive pressure.

[0023] In an optional embodiment, the overflow rate of the low-flow flushing valve 1.5 is set to a low-flow level to maintain the normal pressure-reducing function of the differential pressure reducing valve 1.6 when the spring chamber of the pressure compensation valve is full of control oil, and to limit the flow waste caused by excessive flow through the differential pressure reducing valve 1.6.

[0024] It should be noted that the main function of the low-flow flushing valve 1.5 is to control excessive flow loss in the hydraulic system to ensure the normal operation of other components in the system, especially the normal pressure reduction function of the differential pressure reducing valve 1.6. The setting of the overflow rate to a low flow level is to ensure that the flow rate is not excessive, thereby avoiding unnecessary flow waste in the system and helping to maintain the stability of the liquid flow in the system. The setting of the low-flow flushing valve 1.5 ensures that the pressure reduction function of the differential pressure reducing valve 1.6 is not affected when the pressure compensation valve spring chamber is full of control oil. When the pressure in the hydraulic system increases, the pressure compensation valve adjusts the system pressure to ensure that the oil flow meets the load requirements. 1.5 Ensures that no excessive flow is wasted unnecessarily during this process; without the limitation of the small flow flushing valve 1.5, the system may suffer unnecessary energy loss due to excessive flow, and may even affect the system's working efficiency; by limiting the flow, the system can maintain a highly efficient and stable working state; the function of the small flow flushing valve 1.5 ensures that the pressure regulation range of the differential pressure reducing valve 1.6 will not fluctuate unnecessarily due to excessive flow, maintaining the hydraulic system in a highly efficient working state; by limiting flow waste, the small flow flushing valve 1.5 not only ensures the stability of pressure control, but also improves the overall system operating efficiency and reduces unnecessary energy consumption.

[0025] In an optional embodiment, the flow priority valve 1.9 is equipped with a compensation spring. The valve core is switched by the pressure difference between the compensation spring pressure and the signal input port X2, thereby controlling the on / off relationship between the input port P and the main flow priority output port CF and the main flow excess output port EF, so as to realize the priority distribution of flow.

[0026] It should be noted that the main function of the flow priority valve 1.9 is to ensure priority distribution of flow in the hydraulic system, enabling the system to allocate flow according to actual needs in a priority order, thereby optimizing system performance and response. The flow priority valve 1.9 is equipped with a compensation spring, whose function is to balance the valve core's reversal by adjusting pressure. It switches the valve core based on the pressure difference, thereby controlling the priority order and distribution of hydraulic flow. When a difference occurs between the pressure at signal input port X2 and the set pressure of the compensation spring, the valve core of the flow priority valve 1.9 will reverse. The purpose of the valve core reversal is to adjust the flow distribution according to the pressure difference, so that the system can prioritize providing the required flow. The on / off relationship between the flow priority valve's input port P and the two output ports—the main flow priority output port CF and the main flow excess output port EF—is controlled by the valve core's reversal. After reversal, the valve ensures that the CF port receives priority flow output, while the EF port provides additional flow output when the flow exceeds the limit. In this way, the system can ensure that critical components receive the required flow, thereby improving the system's efficiency and reliability. The design of the flow priority valve allows the system to prioritize the flow requirements of important components, avoiding efficiency losses caused by unstable or uneven flow distribution. By adjusting the pressure difference with a compensating spring, the flow priority valve 1.9 can precisely control the flow distribution in the system, ensuring that each part of the system receives an appropriate flow supply when the load changes. The flow priority valve 1.9 effectively manages the flow changes in the system, ensuring that critical loads receive a stable flow supply, while other parts adjust according to demand, reducing energy waste and unnecessary loads, and improving the response speed and stability of the entire hydraulic system.

[0027] Example 2, please refer to Figure 3 This invention provides a technical solution: a load-sensitive system, which is a single-way multi-valve load-sensitive system, including a dual-mode flow distribution control valve 1, an inverse proportional displacement pump 2, and a downstream compensation multi-way valve 3, wherein: The inverse proportional displacement pump 2 includes an electro-proportional displacement control valve 2.1 and a displacement control oil circuit. The oil inlet is connected to the oil tank, and the output is connected to the oil inlet PA of the downstream compensation multi-way valve 3 and the signal input port Pi of the dual-mode flow distribution control valve 1, respectively. The pressure compensation valve spring chamber signal control port of the post-valve compensation multi-way valve 3 is not directly connected to its own LS oil circuit, and each reversing valve is connected to the actuator travel drive motor. The signal port K1 of the dual-mode flow distribution control valve 1 is connected to the signal external interface oil circuit of the electro-proportional displacement control valve 2.1, the signal port K2 is connected to the displacement control oil circuit of the inverse proportional displacement pump 2, the signal port K3 is connected to the signal control oil circuit of the pressure compensation valve spring chamber of the downstream compensation multi-way valve 3, and the signal port X1 is connected to the LS oil circuit of the downstream compensation multi-way valve 3.

[0028] It should be noted that operating the downstream compensating multi-way valve 3 causes each directional valve to switch according to the signal magnitude ratio, connecting the main oil circuit to the actuator motor oil circuit. Simultaneously, the solenoids of the LS pressure relief control valve 1.1 and the switching valve 1.7 are energized and switched to the right position. At this time, the oil in the LS oil circuit of the downstream compensating multi-way valve 3 flows back to the oil tank through the LS pressure relief control valve 1.1 to relieve pressure. The downstream compensating valve above it loses its pressure compensation function, and the left end of the load-sensitive valve 1.4 is connected to the oil tank but without pressure. The spring on the right end... Under the action of the valve, it remains in the right position. The oil circuits at both ends of the second shuttle valve 1.3 are connected to the oil tank through the load-sensitive valve 1.4 and the inverse proportional displacement control valve 2.1, respectively. There is no pressure signal input. The control oil taken from the output port of the inverse proportional displacement pump 2 to the inlet PA pipeline of the downstream compensation multi-way valve 3 enters the differential pressure reducing valve 1.6 through the Pi port of the switching valve 1.7 for differential pressure reducing. The spring adjustment pressure of the differential pressure reducing valve 1.6 is basically the same as the spring adjustment pressure of the load-sensitive valve 1.4, usually between 1.6 MPa and 2 MPa. Within the MPa range, the depressurized oil enters the spring chamber of the load-sensitive valve 1.4 through the lower signal input / output port of the first shuttle valve 1.2 and enters the spring chamber of the pressure compensation valve of the downstream compensation multi-way valve 3 through signal port X1. The system pressure automatically rises to the pressure required for the motor to drive the load. The flow rate of the small-flow flushing valve 1.5 is very small and is mainly used to maintain the normal pressure reduction of the differential pressure reducing valve 1.6 and limit the flow rate of the differential pressure reducing valve 1.6 from being too large and wasting flow when the spring chamber of the pressure compensation valve is full of control oil. In order to make the output flow rate of the inverse proportional displacement pump 2 consistent with the total flow rate required by each of the reversing valves, it can be achieved through the valve. The total flow rate is obtained by relating the opening area of ​​each valve port of the post-compensation multi-way valve 3 to the corresponding reversing control signal. Then, based on the current speed of the inverse proportional displacement pump 2, the displacement of the inverse proportional displacement pump 2 can be obtained, thereby outputting a certain amount of current to the inverse proportional displacement control valve 2.1. The inverse proportional displacement control valve 2.1 outputs a pressure oil control signal, which enters the displacement control oil circuit of the inverse proportional displacement pump 2 through the signal port K2 of the second shuttle valve 1.3, so that the inverse proportional displacement pump 2 works at the corresponding displacement. The flow rate output by the inverse proportional displacement pump 2 enters the post-compensation multi-way valve 3 and automatically drives each actuator motor according to the load size.

[0029] In an optional embodiment, the downstream compensation multi-way valve 3 is equipped with a small flow flushing valve. When the downstream compensation multi-way valve 3 is not operated, its LS oil route is depressurized by the small flow flushing valve, thereby releasing the pressure at the spring control end of the load-sensitive valve 1.4 in the dual-mode flow distribution control valve 1, and realizing the valve core reversal of the load-sensitive valve 1.4.

[0030] It should be noted that when the solenoids of the inverse proportional displacement control valve 2.1, LS pressure relief control 1.1, and switching valve 1.7 are all de-energized, the inverse proportional displacement control valve 2.1 remains in the right position, the lower signal input port of the second shuttle valve 1.3 is connected to the oil tank, and the LS pressure relief control valve 1.1 and switching valve 1.7 remain in the left position, the control oil taken from the output port of the inverse proportional displacement pump 2 to the inlet PA line of the downstream compensating multi-way valve 3 acts on the inlet of the load-sensitive valve 1.4 and the springless control end through the Pi port of the switching valve 1.7. Since the downstream compensating multi-way valve 3 has not yet been operated, the LS oil circuit pressure oil connected to the spring control end of the load-sensitive valve 1.4 will be depressurized through the small flow flushing valve of the downstream compensating multi-way valve 3, thus the load-sensitive valve 1.4 switches to the left position, and the control oil flows through the load. Sensing valve 1.4 and second shuttle valve 1.3 enter the displacement control oil circuit of inverse proportional displacement pump 2 through signal port K2, minimizing the displacement of inverse proportional displacement pump 2. Simultaneously, the spring control end of the pressure compensation valve of the downstream compensating multi-way valve 3 releases pressure through both ends of the first shuttle valve 1.2. The minimum flow pressure oil output by inverse proportional displacement pump 2 overcomes the pressure compensation valve spring and flows back to the oil tank at the lowest pressure. When the directional valves of the downstream compensating multi-way valve 3 are operated, the directional valves switch according to the magnitude of the operating signal, connecting the main oil circuit PA to the actuator motor oil circuit. At the same time, the downstream compensating valve outputs pressure signal oil to build pressure in the LS oil circuit. At this time, the signal oil in the LS oil circuit enters from signal port X1 and passes through the first shuttle valve 1.2, entering the spring control end of the pressure compensation valve of the downstream compensating multi-way valve 3 and the right end of the load sensing valve 1.4, respectively. The pressure compensation valve closes the return oil. The left and right ends of the load-sensitive valve 1.4 are respectively subjected to the pump main oil circuit pressure and the LS pressure. The two pressures are compared. If the pump main oil circuit pressure is less than the sum of the LS pressure and the spring pressure, the load-sensitive valve 2.4 remains in the right position. The oil circuits at both ends of the second shuttle valve 1.3 are connected to the oil tank through the load-sensitive valve 1.4 and the inverse proportional displacement control valve 2.1, respectively. The displacement control oil circuit pressure of the inverse proportional displacement pump 2 can be relieved through both ends of the second shuttle valve 1.3, thereby increasing the displacement of the inverse proportional displacement pump 2. If the main oil circuit pressure of the pump is greater than the sum of the LS pressure and the spring pressure, the load-sensitive valve 1.4 will switch to the left position. The control oil from the Pi port will enter the displacement control oil circuit of the inverse proportional displacement pump 2 through the load-sensitive valve 1.4 and the second shuttle valve 1.3, thereby reducing the displacement of the inverse proportional displacement pump 2. By continuously comparing the two pressure signals and adjusting, the adjustment will stop when the pressure difference generated by the flow through each directional valve of the downstream compensation multi-way valve 3 is equal to the spring pressure of the load-sensitive valve 1.4, thus ensuring the flow of each directional valve.

[0031] Example 3, please refer to Figure 4 A load-sensitive system, specifically a dual-way valve load-sensitive system, includes a dual-mode flow distribution control valve 1, an inverse proportional displacement pump 2, a downstream compensating multi-way valve 3, and a downstream compensating multi-way valve 4, wherein: The inlet of the inverse proportional displacement pump 2 is connected to the oil tank, and the output port is connected to the oil circuit of the input port P and signal input port Pi of the dual-mode flow distribution control valve 1, respectively. Each of the reversing valves of the downstream compensating multi-way valve 3 is connected to the actuator travel drive motor, and the downstream compensating multi-way valve 4 is connected to other actuators except for the actuator travel drive motor. The signal ports K1, K2, K3, and X1 of the dual-mode flow distribution control valve 1 are connected in the same way as the inverse proportional displacement pump 2, the downstream compensation multi-way valve 3, and the single multi-way valve load-sensitive system. The signal port X2 of the dual-mode flow distribution control valve 1 is connected to the LS oil circuit of the downstream compensation multi-way valve 4, the main flow priority output port CF is connected to the main oil port PB oil circuit of the downstream compensation multi-way valve 4, and the main flow excess output port EF is connected to the main oil port PA oil circuit of the downstream compensation multi-way valve 3.

[0032] It should be noted that when the downstream compensating multi-way valve 3 is operated but the downstream compensating multi-way valve 4 is not operated, the solenoids of the LS pressure relief control valve 1.1 and the switching valve 1.7 are energized. At this time, the working process of the flow distribution mode control valve 1 is the same as that of the single multi-way valve load-sensitive system according to the size of the walking drive load. The pressure oil output by the inverse proportional displacement pump 2 first passes through the flow priority valve 1.9 to determine the flow direction. Since the downstream compensating multi-way valve 4 is not operated, the LS oil route of the downstream compensating multi-way valve 4 is depressurized by the flushing valve inside the valve, and the signal input port X2 connected to it is also depressurized. The upper end of the flow priority valve 1.9 has no pressure action, while the lower end has pressure action from the CF oil route. Therefore, it switches to the lower position, and all the pressure oil output by the inverse proportional displacement pump 2 flows into the downstream compensating multi-way valve 3 through the EF oil route. Its flow control is the same as the control process of the single multi-way valve load-sensitive system. Then, the downstream compensating multi-way valve 3 drives each actuator motor according to the load size, which will not be described again here.

[0033] When both the downstream compensating multi-way valve 3 and the downstream compensating multi-way valve 4 are operated simultaneously, the solenoids of the LS pressure relief control valve 1.1 and the switching valve 1.7 are energized. The operation of the flow distribution mode control valve 1 is the same as that of the single multi-way valve load-sensitive system based on the size of the walking drive load. The pressure oil output by the inverse proportional displacement pump 2 can be divided into two parts. One part enters the downstream compensating multi-way valve 4 through the CF oil circuit of the flow priority valve 1.9. The required flow rate of this part is calculated by the opening area of ​​each valve port of the downstream compensating multi-way valve 4 and the compensating spring pressure of the flow priority valve 1.9. The other part of the flow rate is the required flow rate of the downstream compensating multi-way valve 3. The flow rate can be obtained in the same way as the single multi-way valve load-sensitive system. Therefore, the inverse proportional displacement pump 2 only needs to output the sum of the required flow rate of the downstream compensating multi-way valve 3 and the required flow rate of the downstream compensating multi-way valve 4.

[0034] In an optional embodiment, the post-valve compensation multi-way valve 4 is also equipped with a small flow flushing valve. When the post-valve compensation multi-way valve 4 is not operated, its LS oil route is depressurized by the small flow flushing valve, which releases the pressure at the signal input port X2 of the flow priority valve 1.9 in the dual-mode flow distribution control valve 1, thereby driving the valve core of the flow priority valve 1.9 to switch to the lower position, so that all the pressure oil output by the inverse proportional displacement pump 2 flows into the post-valve compensation multi-way valve 3 through the main flow exceeding the output port EF.

[0035] It should be noted that when the downstream compensating multi-way valve 3 is operated but the downstream compensating multi-way valve 4 is not operated, the solenoids of the LS pressure relief control valve 1.1 and the switching valve 1.7 are de-energized. At this time, the working process of the flow distribution mode control valve 1 is the same as that of the single multi-way valve load-sensitive system with valve orifice area compensation. The pressure oil output by the inverse proportional displacement pump 2 first passes through the flow priority valve 1.9 to determine the flow direction. Since the downstream compensating multi-way valve 4 is not operated, the LS oil route of the downstream compensating multi-way valve 4 is depressurized by the flushing valve inside the valve, and the signal input port X2 connected to it is also depressurized. The upper end of the flow priority valve 1.9 has no pressure action, while the lower end has pressure action from the CF oil route. Therefore, it switches to the lower position, and all the pressure oil output by the inverse proportional displacement pump 2 flows into the downstream compensating multi-way valve 3 through the EF oil route. Its flow rate control is the same as that of the single multi-way valve load-sensitive system with valve orifice area compensation. Then, the downstream compensating multi-way valve 3 drives each actuator motor in the valve orifice area compensation mode, which will not be described again here.

[0036] When both the downstream compensating multi-way valve 3 and the downstream compensating multi-way valve 4 are operated simultaneously, the solenoids of the LS pressure relief control valve 1.1 and the switching valve 1.7 are energized. The operation of the flow distribution mode control valve 1 is the same as that of the single multi-way valve load-sensitive system with valve port area compensation. The pressure oil output by the inverse proportional displacement pump 2 can be divided into two parts. One part enters the downstream compensating multi-way valve 4 through the CF oil circuit of the flow priority valve 1.9. The required flow rate of this part is calculated by the opening area of ​​each valve port of the downstream compensating multi-way valve 4 and the compensation spring pressure of the flow priority valve 1.9. The other part of the flow rate is the required flow rate of the downstream compensating multi-way valve 3. The flow rate can be obtained in the same way as the single multi-way valve load-sensitive system with valve port area compensation. Therefore, the inverse proportional displacement pump 2 only needs to output the sum of the required flow rate of the downstream compensating multi-way valve 3 with valve port area compensation and the required flow rate of the downstream compensating multi-way valve 4.

[0037] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited thereto. Various changes can be made within the scope of knowledge possessed by those skilled in the art without departing from the spirit of the present invention.

Claims

1. A control valve for dual-mode flow distribution, characterized in that, The system includes an LS pressure relief control valve (1.1), a first shuttle valve (1.2), a second shuttle valve (1.3), a load-sensitive valve (1.4), a small-flow flushing valve (1.5), a differential pressure reducing valve (1.6), and a switching valve (1.7). When used to control a load-sensitive system with two multi-way valves, it also includes a third shuttle valve (1.8) and a flow priority valve (1.9). The inlet of the LS pressure relief control valve (1.1) is connected to the upper signal input port and signal port X1 oil circuit of the first shuttle valve (1.2), and the outlet is connected to the oil tank. The lower signal input port of the first shuttle valve (1.2) is connected to the inlet of the small flow flushing valve (1.5) and the outlet oil circuit of the constant differential pressure reducing valve (1.6), respectively. The right signal output port is connected to the signal port K3 oil circuit. The left signal output port is selectively connected to the spring control end oil circuit of the load sensitive valve (1.4) or the lower signal input port oil circuit of the third shuttle valve (1.8). The upper signal input port of the second shuttle valve (1.3) is connected to the oil circuit of the output port of the load sensitive valve (1.4), the lower signal port is connected to the oil circuit of signal port K1, and the signal output port is connected to the oil circuit of signal port K2. The outlet of the low-flow flushing valve (1.5) is connected back to the oil tank; The oil inlet of the switching valve (1.7) is connected to the signal input port Pi oil circuit, the oil return port is connected to the oil tank, one of its working ports is connected to the oil inlet of the load sensitive valve (1.4) and the springless control end respectively, and the other working port is connected to the inlet of the differential pressure reducing valve (1.6). The signal output port of the third shuttle valve (1.8) is connected to the oil circuit of the spring control end of the load-sensitive valve (1.4); The flow priority valve (1.9) is provided with an input port P connected to the main oil circuit, a main flow priority output port CF, a main flow excess output port EF, and a signal input port X2. The signal input port X2 is also connected to the upper signal input port oil circuit of the third shuttle valve (1.8).

2. The control valve for dual-mode flow distribution according to claim 1, characterized in that, The LS pressure relief control valve (1.1) is equipped with an electromagnet. The valve core is switched by the electromagnet being energized or de-energized, thereby controlling the on / off state of the signal port X1 oil circuit and the oil tank. The switching valve (1.7) is also equipped with an electromagnet. The working port connection relationship is switched by the electromagnet being energized or de-energized, thereby realizing the selective connection between the signal input port Pi oil circuit and the oil inlet of the load sensitive valve (1.4) or the inlet of the differential pressure reducing valve (1.6).

3. The control valve for dual-mode flow distribution according to claim 2, characterized in that, The spring adjustment pressure of the differential pressure reducing valve (1.6) is consistent with the spring adjustment pressure of the load sensitive valve (1.4), and the adjustment pressure range is set to 1.6MPa~2MPa, which is used to ensure that the pressure oil after pressure reduction acts stably on the lower signal input port of the first shuttle valve (1.2).

4. The control valve for dual-mode flow distribution according to claim 3, characterized in that, The overflow rate of the low-flow flushing valve (1.5) is set to a low-flow level. This is used to maintain the normal pressure reduction function of the differential pressure reducing valve (1.6) when the spring chamber of the pressure compensation valve is full of control oil, and to limit the flow waste caused by excessive flow through the differential pressure reducing valve (1.6).

5. A control valve for dual-mode flow distribution according to claim 4, characterized in that, The flow priority valve (1.9) is equipped with a compensation spring. The valve core is switched by the pressure difference between the compensation spring pressure and the signal input port X2, thereby controlling the on / off relationship between the input port P and the main flow priority output port CF and the main flow excess output port EF, so as to realize the priority distribution of flow.

6. A load-sensitive system, characterized in that, For a single-way multi-way valve load-sensitive system, the system includes a dual-mode flow distribution control valve (1) as described in any one of claims 1-5, an inverse proportional displacement pump (2), and a downstream compensating multi-way valve (3), wherein: The inverse proportional displacement pump (2) includes an electric proportional displacement control valve (2.1) and a displacement control oil circuit. The oil inlet is connected to the oil tank, and the output port is connected to the oil inlet PA of the valve downstream compensation multi-way valve (3) and the signal input port Pi of the dual-mode flow distribution control valve (1). The pressure compensation valve spring chamber signal control port of the post-valve compensation multi-way valve (3) is not directly connected to its own LS oil circuit, and each reversing valve is connected to the actuator travel drive motor; The signal port K1 of the dual-mode flow distribution control valve (1) is connected to the signal external interface oil circuit of the electro-proportional displacement control valve (2.1), the signal port K2 is connected to the displacement control oil circuit of the inverse proportional displacement pump (2), the signal port K3 is connected to the pressure compensation valve spring chamber signal control port oil circuit of the downstream compensation multi-way valve (3), and the signal port X1 is connected to the LS oil circuit of the downstream compensation multi-way valve (3).

7. A load-sensitive system according to claim 6, characterized in that, The downstream compensation multi-way valve (3) is equipped with a small flow flushing valve. When the downstream compensation multi-way valve (3) is not operated, its LS oil route is depressurized by the small flow flushing valve, which in turn releases the pressure at the spring control end of the load-sensitive valve (1.4) in the dual-mode flow distribution control valve (1), thereby realizing the spool reversal of the load-sensitive valve (1.4).

8. A load-sensitive system, characterized in that, The system is a dual multi-way valve load-sensitive system, comprising a dual-mode flow distribution control valve (1) as described in any one of claims 1-5, an inverse proportional displacement pump (2), a post-valve compensation multi-way valve (3), and a post-valve compensation multi-way valve (4), wherein: The inlet of the inverse proportional displacement pump (2) is connected to the oil tank, and the outlet is connected to the oil circuit of the input port P and signal input port Pi of the dual-mode flow distribution control valve (1). Each of the reversing valves of the downstream compensating multi-way valve (3) is connected to the actuator travel drive motor, and the downstream compensating multi-way valve (4) is connected to other actuators except the actuator travel drive motor. The signal ports K1, K2, K3, and X1 of the dual-mode flow distribution control valve (1) are connected in the same way as the inverse proportional displacement pump (2), the valve post-compensation multi-way valve (3), and the single multi-way valve load-sensitive system. The signal port X2 of the dual-mode flow distribution control valve (1) is connected to the LS oil circuit of the downstream compensation multi-way valve (4), the main flow priority output port CF is connected to the main oil port PB oil circuit of the downstream compensation multi-way valve (4), and the main flow excess output port EF is connected to the main oil port PA oil circuit of the downstream compensation multi-way valve (3).

9. A load-sensitive system according to claim 8, characterized in that, The post-valve compensation multi-way valve (4) is also equipped with a small flow flushing valve. When the post-valve compensation multi-way valve (4) is not operated, its LS oil route is depressurized by the small flow flushing valve, which releases the X2 pressure of the signal input port of the flow priority valve (1.9) in the dual-mode flow distribution control valve (1), thereby driving the valve core of the flow priority valve (1.9) to switch to the lower position, so that all the output pressure oil of the inverse proportional displacement pump (2) flows into the post-valve compensation multi-way valve (3) through the main flow exceeding the output port EF.

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