A hydraulic system input flow control hydraulic system

Abstract

The utility model relates to the field of hydraulic control, especially a kind of hydraulic system of hydraulic system input flow control, including pressure source, control part, execution part, pressure source, control part between pressure oil circuit setting first pressure point, control part, execution part between pressure oil circuit setting second pressure point, control part real-time monitoring the pressure difference of first pressure point, second pressure point, when the pressure difference is greater than set pressure difference range, reduce system flow, when the pressure difference is less than set pressure difference range, increase system flow.The utility model passes through real-time monitoring pressure difference and dynamic adjustment motor speed, make system output flow and load demand match, significantly reduce overflow loss, improve energy utilization efficiency.

Description

Technical Field

[0001] This utility model relates to the field of hydraulic control, and in particular to a hydraulic system for controlling the input flow of a hydraulic system. Background Technology

[0002] Fixed displacement pumps, especially gear pumps, have advantages such as low cost and strong resistance to contamination. For a long time, due to structural limitations, fixed displacement pumps could only regulate excess flow and maintain system pressure through a relief valve, resulting in significant energy loss and limiting their application to hydraulic systems with relatively constant output flow. Fixed displacement pumps are fixed-displacement pumps and lack load feedback circuits, making it impossible to sense load conditions and thus unable to work with load-sensitive systems to provide the required flow rate in real time. Utility Model Content

[0003] To address the shortcomings of existing technologies, this invention provides a hydraulic system for controlling the input flow of a hydraulic system, which enables adaptive adjustment of the system flow.

[0004] The technical solution adopted by this utility model is: a hydraulic system for controlling the input flow of a hydraulic system, including a pressure source, a control part, and an execution part. A first pressure measuring point is set in the pressure oil circuit between the pressure source and the control part, and a second pressure measuring point is set in the pressure oil circuit between the control part and the execution part. The control part monitors the pressure difference between the first pressure measuring point and the second pressure measuring point in real time. When the pressure difference is greater than a set pressure difference range, the system flow is reduced; when the pressure difference is less than the set pressure difference range, the system flow is increased.

[0005] Furthermore, the pressure source includes a motor and a fixed displacement pump driven by it. The control unit monitors the pressure difference between the first and second pressure measuring points in real time. When the pressure difference is greater than the set pressure difference range, the motor speed is reduced. When the pressure difference is less than the set pressure difference range, the motor speed is increased.

[0006] Furthermore, the control section is a variable damping system, with the first pressure measuring point set at the variable damping input terminal and the second pressure measuring point set at the variable damping output terminal. The first and second pressure measuring points are respectively connected to the controller input terminal.

[0007] Furthermore, the control unit includes a priority valve and a steering gear arranged in sequence. The steering gear is equipped with a load-sensitive oil circuit. The first pressure test point is set at the oil inlet of the priority valve, and the second pressure test point is set at the load-sensitive oil circuit of the steering gear. The first pressure test point and the second pressure test point are respectively connected to the input terminal of the controller.

[0008] Furthermore, the control unit includes a steering gear and a priority steering flow amplification valve. The steering gear and the priority steering flow amplification valve are equipped with load-sensitive oil circuits. The first pressure test point is set at the oil inlet of the steering gear and the priority steering flow amplification valve, and the second pressure test point is set at the load-sensitive oil circuit of the steering gear and the priority steering flow amplification valve. The first pressure test point and the second pressure test point are respectively connected to the controller input terminal.

[0009] Furthermore, the control section includes a proportional directional valve, which has two working ports. During operation, the ports are connected to the actuator inlet and outlet ports respectively. The first pressure test point is set at the inlet port of the proportional directional valve, and the second pressure test point is connected to the outlet port of the shuttle valve. The two inlets of the shuttle valve are connected to the two working ports of the proportional directional valve respectively. The first pressure test point and the second pressure test point are connected to the controller input terminal respectively.

[0010] Furthermore, the control section includes a multi-way valve, which is equipped with a load-sensitive oil circuit. The first pressure test point is located at the oil inlet of the multi-way valve, and the second pressure test point is connected to the load-sensitive oil circuit of the multi-way valve. The first pressure test point and the second pressure test point are respectively connected to the input terminal of the controller.

[0011] Furthermore, the control section also includes a differential relief valve, whose inlet is connected to the inlet of the multi-way valve, two control ports are respectively connected to the inlet of the multi-way valve and the load-sensitive oil circuit, and the outlet is connected to the oil tank.

[0012] Furthermore, the set differential pressure of the equal differential relief valve is higher than the set differential pressure range of the controller.

[0013] This invention achieves real-time monitoring of differential pressure and dynamic adjustment of motor speed, matching the system's output flow rate with load demand, significantly reducing overflow losses and improving energy utilization efficiency. Simultaneously, it realizes adaptive flow control, allowing the system to automatically adjust the input flow rate for "on-demand oil supply," avoiding excessive or insufficient flow and remaining unaffected by load. Combined with components such as differential relief valves, it further suppresses pressure fluctuations, improving system stability and reliability. It boasts strong compatibility and is suitable for various hydraulic systems. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the system in Embodiment 1 of this utility model; Figure 2 This is a schematic diagram of the system in Embodiment 2 of this utility model; Figure 3 This is a schematic diagram of the system in Embodiment 3 of this utility model; Figure 4 This is a schematic diagram of the system in Embodiment 4 of this utility model; Figure 5 This is a schematic diagram of the system in Embodiment 5 of this utility model; Figure 6 This is a schematic diagram of the multi-way valve in Embodiment 5 of this utility model.

[0015] In the diagram: 10-displacement pump, 11-motor, 12-controller, 2-multi-way valve, 21-main valve core, 22-load-sensitive valve core, 25-first relief valve, 26-second relief valve, 27-load-sensitive constant flow valve, 3-proportional pilot control module, 4-variable damping, 5-director, 6-priority valve, 7-priority directional flow amplification valve, 8-proportional directional valve, 9-shuttle valve. Detailed Implementation

[0016] Example 1: like Figure 1 The diagram shows a simplified hydraulic system, including a motor 11, a fixed displacement pump 10, a variable damper 4, an actuator, and a controller 12. The variable damper 4 has a first pressure measuring point at its input and a second pressure measuring point at its output. The first and second pressure measuring points are connected to the input of the controller 12. The controller 12 obtains the pressure difference through the first and second pressure measuring points. If the pressure difference is greater than the set pressure difference range, the motor speed is reduced; if the pressure difference is less than the set pressure difference range, the motor speed is increased.

[0017] Example 2: like Figure 2 As shown, a direct-drive steering hydraulic system includes a motor 11, a fixed-displacement pump 10, a priority valve 6, and a steering gear 5 arranged sequentially. The steering gear 5 is provided with a load-sensitive oil circuit. A first pressure measuring point is set at the oil inlet of the priority valve 6, and a second pressure measuring point is set on the load-sensitive oil circuit of the steering gear 5. The first and second pressure measuring points are respectively connected to the input terminals of the controller 12. The controller 12 obtains the pressure difference through the first and second pressure measuring points. If the pressure difference is greater than the set pressure difference range, the motor speed is reduced; if the pressure difference is less than the set pressure difference range, the motor speed is increased.

[0018] Example 3: like Figure 3 As shown, a steering hydraulic system employing a priority steering flow amplification valve includes a motor 11, a fixed displacement pump 10, a steering gear 5, and a priority steering flow amplification valve 7. The steering gear 5 and the priority steering flow amplification valve 7 are equipped with load-sensitive oil circuits. A first pressure measuring point is set at the oil inlet of the steering gear 5 and the priority steering flow amplification valve 7, and a second pressure measuring point is set in the load-sensitive oil circuit of the steering gear 5 and the priority steering flow amplification valve 7. The first pressure measuring point and the second pressure measuring point are respectively connected to the input terminal of the controller 12. The controller 12 obtains the pressure difference through the first pressure measuring point and the second pressure measuring point. If the pressure difference is greater than the set pressure difference range, the motor speed is reduced; if the pressure difference is less than the set pressure difference range, the motor speed is increased.

[0019] Example 4: like Figure 4As shown, a hydraulic reversing system includes a motor 11, a fixed displacement pump 10, and a proportional reversing valve 8. The proportional reversing valve 8 has two working ports, which are connected to the inlet and outlet ports of the actuator during operation. A first pressure measuring point is set at the inlet port of the proportional reversing valve 8. A shuttle valve 9 is set between the two working ports of the proportional reversing valve 8. The two inlets of the shuttle valve 9 are connected to the two working ports of the proportional reversing valve 8, respectively. The second pressure measuring point is connected to the outlet port of the shuttle valve 9. The first and second pressure measuring points are connected to the input terminals of the controller 12. The controller 12 obtains the pressure difference through the first and second pressure measuring points. If the pressure difference is greater than the set pressure difference range, the motor speed is reduced; if the pressure difference is less than the set pressure difference range, the motor speed is increased.

[0020] Example 5: like Figure 5 As shown, a load-sensitive system based on a metering pump includes a metering pump 10, a motor 11, a controller 12, a multi-way valve 2, and a proportional pilot control module 3. The multi-way valve 2 is a load-sensitive multi-way valve, including two sets of reversing couplings, a first relief valve 25, a second relief valve 26, and a load-sensitive constant flow valve 27. The multi-way valve 2 can be an open-center multi-way valve, a closed-center multi-way valve, or any other type of multi-way valve structure, and can also include any set of reversing couplings.

[0021] like Figure 6 As shown, the reversing coupling includes a main valve core 21 and a load-sensitive valve core 22 disposed within the valve body. The reversing coupling valve body is provided with a P port, a T port, and working oil ports A and B. The main valve core 21 is proportionally controlled and is provided with left, middle, and right positions. Transitional ports P1 and P2 are provided between ports P and A and B. The load-sensitive valve core is disposed between ports P1 and P2, and is provided with left, middle, and right positions. The pilot oil circuits on both sides of the load-sensitive valve core are respectively connected to port P1 and the system load-sensitive oil circuit. The proportional control of its displacement is achieved by the pressure of port P1 and the system load-sensitive oil circuit. The oil inlet of the load-sensitive valve core is connected to port P1, and the two oil outlets are respectively connected to the system load-sensitive oil circuit and port P2. The oil outlet and oil inlet connected to the system load-sensitive oil circuit are connected through an internal oil passage of the valve core. The opening between the oil outlet and oil inlet connected to port P2 is controlled by the displacement of the load-sensitive valve core.

[0022] Both ends of the main valve core 21 are equipped with hydraulic pilot oil circuits for controlling the valve core reversing. Each hydraulic pilot oil circuit is controlled by a proportional pilot control module 3. The proportional pilot control module 3 includes several proportional pressure reducing valves. The input end of each proportional pressure reducing valve is connected to a pilot pressure source, and the output end corresponds to each pilot control oil circuit of the multi-way valve reversing linkage and the proportional reversing valve, respectively. By adjusting the output pressure through the proportional pressure reducing valves, the displacement of the corresponding valve core is controlled. In this embodiment, the proportional pressure reducing valve electromagnet is controlled by the control terminals XD1-XD4 of the controller 12.

[0023] The first relief valve 25 is a differential pressure relief valve. Its inlet is connected to the system pressure oil circuit, its two control ports are connected to the system pressure oil circuit and the load-sensitive oil circuit respectively, and its outlet is connected to the return oil line. The load-sensitive oil circuit is marked as LS in the figure. The differential pressure setting value of the first relief valve 25 is higher than the set pressure range of the controller 12. When the differential pressure between the multi-way valve P port and the load-sensitive oil circuit is too large, the system flow can be adjusted by reducing the input flow by decreasing the motor speed and by draining oil from the differential pressure relief valve. The first relief valve 25 can also relieve instantaneous pressure fluctuations in the system to prevent damage to the components in the system from impact.

[0024] The second overflow valve 26 and the load-sensitive constant flow valve 27 are connected in parallel. The oil inlet of the second overflow valve 26 and the oil port on one side of the load-sensitive constant flow valve 27 are connected to the load-sensitive oil circuit. The oil outlet of the second overflow valve 26 and the oil port on the other side of the load-sensitive constant flow valve 27 are connected to a separate oil circuit to return to the oil tank to avoid interference from the return oil of other components.

[0025] The first pressure test point is set at the P port of the multi-way valve, and the second pressure test point is set at the load-sensitive oil circuit. The first and second pressure test points are respectively connected to the input terminal of the controller. The controller obtains the pressure difference through the first and second pressure test points. The controller 12 acts as a flow regulation mechanism and sets the pressure difference range of the load-sensitive oil circuit and the P port oil circuit of the multi-way valve according to the actual working conditions.

[0026] Standby mode: All working links are in the neutral position, the pressure of the load-sensitive oil circuit has not yet been established, and it is in a low pressure or 0 pressure state. The flow from the pump overflows through the first relief valve 25 and flows back to the oil tank at T port under low pressure.

[0027] Operating conditions: When the oil circuit from port P of the multi-way valve to the working oil port AB is opened, the pressure in the load-sensitive oil circuit is established. The controller starts to control the speed of motor 11 according to the pressure difference between port P of the multi-way valve and the load-sensitive oil circuit: When the pressure difference between port P of the multi-way valve and the load-sensitive oil circuit is lower than the set pressure range, it means that the pump output flow cannot meet the working flow, so the speed of motor 11 is increased to increase the system flow; when the pressure difference between port P of the multi-way valve and the load-sensitive oil circuit is higher than the set pressure range, it means that the pump output flow is too large, so the speed of motor 11 is reduced to decrease the system flow; when the pressure difference between port P of the multi-way valve and the load-sensitive oil circuit is within the set pressure range, the speed of motor 11 remains unchanged.

Claims

1. A hydraulic system for controlling the input flow rate of a hydraulic system, characterized in that: It includes a pressure source, a control section, and an execution section. A first pressure measuring point is set in the pressure oil circuit between the pressure source and the control section, and a second pressure measuring point is set in the pressure oil circuit between the control section and the execution section. The control section monitors the pressure difference between the first pressure measuring point and the second pressure measuring point in real time. When the pressure difference is greater than a set pressure difference range, the system flow rate is reduced; when the pressure difference is less than the set pressure difference range, the system flow rate is increased.

2. The hydraulic system for controlling the input flow rate of a hydraulic system according to claim 1, characterized in that: The pressure source includes a motor and a metering pump driven by it. The control unit monitors the pressure difference between the first and second pressure measuring points in real time. When the pressure difference is greater than the set pressure difference range, the motor speed is reduced. When the pressure difference is less than the set pressure difference range, the motor speed is increased.

3. A hydraulic system for controlling the input flow rate of a hydraulic system according to claim 1 or 2, characterized in that: The control unit is a variable damper. The first pressure measuring point is set at the input terminal of the variable damper, and the second pressure measuring point is set at the output terminal of the variable damper. The first pressure measuring point and the second pressure measuring point are respectively connected to the input terminal of the controller.

4. A hydraulic system for controlling the input flow rate of a hydraulic system according to claim 1 or 2, characterized in that: The control unit includes a priority valve and a steering gear arranged in sequence. The steering gear is provided with a load-sensitive oil circuit. The first pressure test point is set at the oil inlet of the priority valve, and the second pressure test point is set at the load-sensitive oil circuit of the steering gear. The first pressure test point and the second pressure test point are respectively connected to the input terminal of the controller.

5. A hydraulic system for controlling the input flow rate of a hydraulic system according to claim 1 or 2, characterized in that: The control unit includes a steering gear and a priority steering flow amplification valve. The steering gear and the priority steering flow amplification valve are equipped with load-sensitive oil circuits. The first pressure measuring point is located at the oil inlet of the steering gear and the priority steering flow amplification valve, and the second pressure measuring point is located at the load-sensitive oil circuit of the steering gear and the priority steering flow amplification valve. The first pressure measuring point and the second pressure measuring point are respectively connected to the controller input terminal.

6. A hydraulic system for controlling the input flow rate of a hydraulic system according to claim 1 or 2, characterized in that: The control unit includes a proportional directional valve with two working ports, which are connected to the actuator inlet and outlet ports respectively during operation. The first pressure test point is located at the inlet port of the proportional directional valve, and the second pressure test point is connected to the outlet port of the shuttle valve. The two inlets of the shuttle valve are respectively connected to the two working ports of the proportional directional valve. The first pressure test point and the second pressure test point are respectively connected to the controller input terminal.

7. A hydraulic system for controlling the input flow rate of a hydraulic system according to claim 1 or 2, characterized in that: The control unit includes a multi-way valve, which is equipped with a load-sensitive oil circuit. The first pressure test point is located at the oil inlet of the multi-way valve, and the second pressure test point is connected to the load-sensitive oil circuit of the multi-way valve. The first pressure test point and the second pressure test point are respectively connected to the input terminal of the controller.

8. A hydraulic system for controlling the input flow rate of a hydraulic system according to claim 7, characterized in that: The control section also includes a differential overflow valve, the oil inlet of which is connected to the oil inlet of the multi-way valve, the two control ports are respectively connected to the oil inlet of the multi-way valve and the load-sensitive oil circuit, and the oil outlet is connected to the oil tank.

9. A hydraulic system for controlling the input flow rate of a hydraulic system according to claim 8, characterized in that: The set differential pressure of the equal differential relief valve is higher than the set differential pressure range of the controller.

Images