High-precision quick-response electro-hydraulic actuator

Abstract

The utility model discloses a high-precision quick-response electro-hydraulic actuator which comprises an oil tank, a plunger pump, a servo motor, a one-way valve, a pressure limiting valve, a hydraulic lock, a three-position four-way electromagnetic valve, an oil cylinder and an electric controller, the plunger pump is driven by the servo motor, an inlet of the plunger pump is connected with the oil tank, and an outlet of the plunger pump is connected with a port P of the three-position four-way electromagnetic valve through an oil inlet pipe; a one-way valve and a flow sensor are connected to the oil inlet pipe in series, a T port of the three-position four-way electromagnetic valve is connected with the oil tank through an oil return pipe, an inlet of the pressure limiting valve is connected to a pipeline between the one-way valve and the plunger pump, an outlet of the pressure limiting valve is connected with the oil return pipe, and an A port and a B port of the three-position four-way electromagnetic valve are connected with two P ports of the hydraulic lock through oil pipes in a one-to-one mode. Two A ports on the hydraulic lock are respectively connected with two cavities of the oil cylinder in a one-to-one mode through pressure oil pipes, and the two pressure oil pipes are respectively connected with a pressure sensor in series and are further provided with a displacement sensor. The electro-hydraulic actuator can achieve high stability, high precision and quick response.

Description

Technical Field

[0001] The utility model relates to the field of electro-hydraulic actuators, in particular to a high-precision and fast-response electro-hydraulic actuator. Background Art

[0002] Electro-hydraulic actuators are devices in automation technology tools that receive control information and exert control on controlled objects, usually valves. Traditional electro-hydraulic actuators mostly use integrated operational amplifiers as the core control technology. Due to the instability of the integrated operational amplifiers themselves and the design problems of the oil circuits of the electro-hydraulic actuators themselves, electro-hydraulic actuators have the disadvantages of poor stability, low precision, slow response, and are not conducive to centralized control and remote control. Utility Model Content

[0003] The technical problem to be solved by the utility model is to provide a high-precision and fast-response electro-hydraulic actuator with good stability, high precision and fast response.

[0004] In order to solve the above problems, the technical solution adopted by the utility model is: a high-precision and fast-response electro-hydraulic actuator, including: an oil tank, a plunger pump, a servo motor, a one-way valve, a pressure-limiting valve, a hydraulic lock, a three-position four-way solenoid valve, an oil cylinder, and an electronic controller, characterized in that: the plunger pump is driven by a servo motor, so that the plunger pump can output a hydraulic oil flow with a fast response and accurate flow rate, the inlet of the plunger pump is connected to the oil tank through an oil pipe, the outlet of the plunger pump is connected to the P port of the three-position four-way solenoid valve through an oil inlet pipe, a one-way valve and a flow sensor are connected in series on the oil inlet pipe in sequence along the flow direction, the T port of the three-position four-way solenoid valve is connected to the oil tank through an oil return pipe, and the pressure-limiting valve is located between the oil inlet pipe and the return pipe. The inlet of the pressure-limiting valve is connected to the pipeline between the one-way valve and the plunger pump through the oil pipe, the outlet of the pressure-limiting valve is connected to the oil return pipe through the oil pipe, the A port and the B port of the three-position four-way solenoid valve are connected one-to-one with the two P ports of the hydraulic lock through the oil pipe, and the two A ports on the hydraulic lock corresponding to the two P ports are connected one-to-one with the two chambers of the cylinder through the pressure oil pipe. Pressure sensors are connected in series on the two pressure oil pipes, and a displacement sensor for detecting the position and speed of the cylinder piston rod is also provided. The servo motor, the flow sensor, the VC and VO ends of the three-position four-way solenoid valve, the two pressure sensors, and the displacement sensor are all electrically connected to the electronic controller.

[0005] Furthermore, the aforementioned high-precision and fast-response electro-hydraulic actuator, wherein: the structure of the electronic controller includes: an electronic control box, on which are arranged an operation panel, an ECU, a drive module, a power switch, and a signal conversion interface, the operation panel is connected to the ECU, the power switch is connected to the drive module, the power supply is connected to the power switch, the drive module is connected to the ECU, the servo motor is connected to the drive module, two pressure sensors, a flow sensor, and the VC and VO ends of a three-position four-way solenoid valve are connected to the ECU, and the signal conversion interface is connected to the ECU.

[0006] Furthermore, in the aforementioned high-precision fast-response electro-hydraulic actuator, the displacement sensor is a magnetostrictive high-precision displacement sensor.

[0007] Furthermore, the aforementioned high-precision and fast-response electro-hydraulic actuator, wherein: a manual pump module is also provided, the manual pump module is connected to the two chambers of the oil cylinder through an oil pipe, and the oil cylinder can be manually driven through the manual pump module.

[0008] The advantages of the utility model are as follows: the utility model adopts a single-chip microcomputer controller with high cost performance to replace the traditional operational amplifier to realize signal processing. The single-chip microcomputer controller has strong data acquisition, processing, memory, storage and communication functions, and has high accuracy and good human-machine interface and fault diagnosis capabilities; a high-precision servo motor is matched with a high-precision plunger pump to improve the oil filling accuracy of the cylinder; a high-precision displacement sensor is used for position feedback to ensure feedback accuracy; a flow sensor and a pressure sensor are used as auxiliary detection; a high-precision servo motor is used to drive the plunger pump to pump oil into the cylinder, and at the same time, a magnetostrictive high-precision displacement sensor and a flow and pressure transmitter are used to perform position, flow and pressure detection, so that the electro-hydraulic actuator can achieve high stability, high accuracy and rapid response. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 This is a hydraulic principle diagram of the high-precision and fast-response electro-hydraulic actuator described in the utility model.

[0010] Figure 2 This is a control principle diagram of the high-precision and fast-response electro-hydraulic actuator described in the utility model. DETAILED DESCRIPTION

[0011] The present invention will be described in further detail below in conjunction with specific embodiments and accompanying drawings.

[0012] like Figure 1 , Figure 2As shown, the high-precision and fast-response electro-hydraulic actuator comprises: an oil tank 1, a plunger pump 2, a servo motor 3, a one-way valve 4, a pressure-limiting valve 5, a hydraulic lock 6, a three-position four-way solenoid valve 7, an oil cylinder 8, and an electronic controller 11. The plunger pump 2 is driven by the servo motor 3, so that the plunger pump 2 can output a hydraulic oil flow with a fast response and precise flow rate. The inlet of the plunger pump 2 is connected to the oil tank 1 through an oil pipe, and the outlet of the plunger pump 2 is connected to the P port of the three-position four-way solenoid valve 7 through an oil inlet pipe 19. The one-way valve 4 and the flow sensor 9 are connected in series on the oil inlet pipe 19 in sequence along the flow direction. The T port of the three-position four-way solenoid valve 7 is connected to the oil tank 1 through an oil return pipe 20. The pressure-limiting valve 5 is located between the oil inlet pipe 19 and the oil return pipe 20. The outlet of the pressure limiting valve 5 is connected to the pipeline between the one-way valve 4 and the plunger pump 2 through an oil pipe, the outlet of the pressure limiting valve 5 is connected to the return oil pipe 20 through an oil pipe, the A port and the B port of the three-position four-way solenoid valve 7 are connected one-to-one with the two P ports of the hydraulic lock 6 through oil pipes, respectively, and the two A ports on the hydraulic lock 6 corresponding to its two P ports are connected one-to-one with the two chambers of the cylinder 8 through pressure oil pipes 21, respectively. Pressure sensors 10 are connected in series on the two pressure oil pipes 21, and a displacement sensor 12 for detecting the position and speed of the piston rod of the cylinder 8 is also provided. The servo motor 3, the flow sensor 9, the VC and VO ends of the three-position four-way solenoid valve 7, the two pressure sensors 10, and the displacement sensor 12 are all electrically connected to the electronic controller 11.

[0013] The hydraulic lock 6 is a conventional hydraulic component with a self-locking function. When the hydraulic lock 6 is closed, the two groups of corresponding P and A ports on the hydraulic lock 6 are cut off and cannot be connected to each other; the hydraulic lock 6 can only be opened after high-pressure hydraulic oil is delivered to any one of the P ports of the hydraulic lock 6, that is, the two groups of corresponding P and A ports are connected to each other.

[0014] The structure of the electronic controller 11 includes: an electronic control box, on which an operation panel 13, an ECU, a drive module 15, a power switch 16, and a signal conversion interface 17 are arranged. ECU is the abbreviation of electronic control unit. The operation panel 13 is connected to the ECU, the power switch 16 is connected to the drive module 15, the power supply is connected to the power switch 16, the drive module 15 is connected to the ECU, the servo motor 3 is connected to the drive module 15, two pressure sensors 10, a flow sensor 9, and VC and VO ends of a three-position four-way solenoid valve 7 are connected to the ECU, and the signal conversion interface 17 is connected to the ECU.

[0015] In order to enable accurate detection, the displacement sensor 12 is a magnetostrictive high-precision displacement sensor.

[0016] A manual pump module 18 is also provided, and the manual pump module 18 is connected to the two chambers of the oil cylinder 8 through an oil pipe, and the oil cylinder 8 can be manually driven through the manual pump module 18.

[0017] Valve opening process:

[0018] The plunger pump 2 is started, and the high-pressure oil is output through the one-way valve 4, and the pressure limiting valve 5 limits the maximum pressure. The VO end of the three-position four-way solenoid valve 7 is energized, and the high-pressure oil passes through the three-position four-way solenoid valve 7 and the hydraulic lock 6 into the A chamber of the cylinder 8. The low-pressure oil in the B chamber of the cylinder 8 passes through the hydraulic lock 6 and the three-position four-way solenoid valve 7 and returns to the oil tank 1, thereby pushing the piston of the cylinder 8 upward.

[0019] Valve closing process:

[0020] The plunger pump 2 is started, and the high-pressure oil is output through the one-way valve, and the pressure limiting valve 5 limits the maximum pressure. The VC end of the three-position four-way solenoid valve 7 is energized, and the high-pressure oil passes through the three-position four-way solenoid valve 7 and the hydraulic lock 6 into the B chamber of the cylinder 8. The low-pressure oil in the A chamber of the cylinder 8 passes through the hydraulic lock 6 and the three-position four-way solenoid valve 7 and returns to the oil tank, thereby pushing the piston of the cylinder 8 downward.

[0021] Position Hold:

[0022] When the three-position four-way solenoid valve 7 loses power and resets, and the servo motor 3 stops running, the hydraulic lock 6 is locked, the hydraulic oil is sealed in the A chamber and the B chamber of the oil cylinder 8, and the oil cylinder 8 is locked in the current position.

[0023] Output torque control:

[0024] Pressure sensors 10 are respectively installed on the two pressure oil pipes 21 connected to the A chamber and the B chamber of the oil cylinder 8. The pressure values ​​detected by the two pressure sensors 10 are transmitted to the electronic controller 11. The electronic controller 11 calculates the real-time output torque of the oil cylinder 8 according to the piston size of the oil cylinder 8 and the pressure difference between the A chamber and the B chamber. When the torque is abnormal, the operation of the plunger pump 2 is stopped and an alarm is issued.

[0025] When the pressure sensor 10 is abnormal, the pressure limiting valve 5 plays a role in limiting the maximum pressure of the hydraulic system to ensure the safety of the hydraulic system and the load.

[0026] Positioning control:

[0027] The displacement sensor 12 detects the actual position and running speed of the piston of the oil cylinder 8 and transmits it to the electronic controller 11. The electronic controller 11 precisely controls the speed of the servo motor 3 according to the position required by the instruction to achieve the purpose of precise positioning.

[0028] Large changes in ambient temperature and load will cause changes in the operating speed of the cylinder 8, affecting the positioning accuracy. The flow sensor 9 installed at the outlet of the plunger pump 2 monitors the actual output flow of the plunger pump 2 in real time and transmits it to the electronic controller 11. The electronic controller 11 compensates the speed of the servo motor 3 in real time through calculation to achieve a stable hydraulic oil flow and ensure precise positioning of the electro-hydraulic actuator.

Claims

1. High-precision and fast-response electro-hydraulic actuator, including: Oil tank, plunger pump, servo motor, one-way valve, pressure-limiting valve, hydraulic lock, three-position four-way solenoid valve, oil cylinder, electronic controller, characterized in that: the plunger pump is driven by the servo motor, so that the plunger pump can output a hydraulic oil flow with fast response and accurate flow, the inlet of the plunger pump is connected to the oil tank through an oil pipe, the outlet of the plunger pump is connected to the P port of the three-position four-way solenoid valve through an oil inlet pipe, a one-way valve and a flow sensor are connected in series in sequence on the oil inlet pipe along the flow direction, the T port of the three-position four-way solenoid valve is connected to the oil tank through an oil return pipe, the pressure-limiting valve is located between the oil inlet pipe and the oil return pipe, and the inlet of the pressure-limiting valve is connected to the one-way valve through an oil pipe On the pipeline between the valve and the plunger pump, the outlet of the pressure limiting valve is connected with the return oil pipe through the oil pipe, the A port and B port of the three-position four-way solenoid valve are connected one-to-one with the two P ports of the hydraulic lock through the oil pipes, and the two A ports on the hydraulic lock corresponding to its two P ports are connected one-to-one with the two chambers of the cylinder through pressure oil pipes. Pressure sensors are connected in series on the two pressure oil pipes, and displacement sensors for detecting the position and speed of the cylinder piston rod are also provided. The servo motor, flow sensor, VC and VO ends of the three-position four-way solenoid valve, two pressure sensors, and displacement sensor are all electrically connected to the electronic controller.

2. The high-precision and fast-response electro-hydraulic actuator according to claim 1, characterized in that: The structure of the electronic controller includes: an electronic control box, on which an operation panel, an ECU, a drive module, a power switch, and a signal conversion interface are arranged. The operation panel is connected to the ECU, the power switch is connected to the drive module, the power supply is connected to the power switch, the drive module is connected to the ECU, the servo motor is connected to the drive module, two pressure sensors, a flow sensor, and the VC and VO ends of a three-position four-way solenoid valve are connected to the ECU, and the signal conversion interface is connected to the ECU.

3. The high-precision and fast-response electro-hydraulic actuator according to claim 1 or 2, characterized in that: The displacement sensor is a magnetostrictive high-precision displacement sensor.

4. The high-precision and fast-response electro-hydraulic actuator according to claim 1 or 2, characterized in that: A manual pump module is also provided, which is connected to the two chambers of the oil cylinder through an oil pipe, and the oil cylinder can be manually driven through the manual pump module.

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