Low-throttling-loss flow distribution control system

Abstract

The invention belongs to the technical field of hydraulic valve control, and particularly relates to a low-throttling-loss flow distribution control system, a linear actuator is adopted, meanwhile, a displacement sensor is adopted to detect the displacement of a valve element of a pressure compensation valve, a signal is fed back to a controller, and the controller achieves the purpose of low flow loss by controlling the rotating speed of a motor. The system response is quickened, the problem of large throttling of the load compensation valve is solved, and meanwhile the load compensation valve still has the flow distribution function.

Description

Technical Field

[0001] The invention relates to a low throttling loss flow distribution control system, belonging to the technical field of hydraulic valve control. Background Art

[0002] In the hydraulic system, the flow of hydraulic oil is controlled by the throttle to achieve the control of the actuator movement speed. However, when the pressure difference before and after the throttle changes too much and it cannot accurately control the circuit flow, a pressure compensation valve is needed to control the pressure difference before and after the throttle. The traditional pre-valve compensation system arranges the pressure compensation valve between the hydraulic pump and the main valve. At this time, the flow rate is only related to the opening of the throttle valve port and is not affected by the load pressure. The load speed can be better controlled. However, when the flow rate provided by the main pump cannot meet the flow rate required by the system, the adjustment function of the pressure compensation valve fails, and the flow rate of the main pump is preferentially supplied to the actuator with a small load, and cannot meet the work of the actuator with a high load pressure.

[0003] Post-valve compensation is to arrange the pressure compensation valve between the main valve and the actuator. The system has anti-saturation function. When the flow provided by the main pump cannot meet the flow required by the system, the system will also distribute the flow proportionally, reducing the flow supply to the load actuator year-on-year, rather than making the flow flow preferentially to the actuator with small load pressure. However, the speed regulation rigidity of the system is relatively poor, and the response speed of the system is relatively slow. Summary of the invention

[0004] In view of the problems of slow dynamic response and excessive load system flow distribution in traditional load-sensitive circuits, the technical solution adopted by the present invention is: a low throttling loss flow distribution control system, characterized in that it includes a one-way variable pump, an oil tank, a two-way variable piston cylinder, a first load-sensitive control circuit, a second load-sensitive control circuit and a controller; the two load-sensitive control oil circuits are connected to the oil outlet of the one-way variable pump in parallel, the oil inlet of the one-way variable pump is connected to the oil tank, and the oil port at one end of the two-way variable piston cylinder is connected to the oil outlet of the one-way variable pump, which is controlled by the displacement of the one-way variable pump. At the same time, the extension and retraction of the rod at this end controls the displacement of the one-way variable pump.

[0005] The first load-sensitive control circuit includes a first two-position two-way throttle valve, a first pressure-compensating valve, a first displacement sensor, a first three-position four-way reversing solenoid valve, a first continuous variable motor, a first hydraulic motor-mechanical linear actuator and a first shuttle valve; the oil inlet of the first two-position two-way throttle valve is connected to the oil outlet of the one-way variable pump, the oil outlet of the first two-position two-way throttle valve is connected to the oil inlet of the first pressure-compensating valve, the oil outlet of the first pressure-compensating valve is connected to the P port of the first three-position four-way reversing solenoid valve, and the A port of the first three-position four-way reversing solenoid valve is connected to the oil outlet of the first three-position four-way reversing solenoid valve. The A and B ports are respectively connected to the two interfaces of the Ith continuously variable motor, the Ith displacement sensor is connected to the Ith pressure compensation valve to detect the displacement of the valve core of the Ith pressure compensation valve, the other side of the Ith displacement sensor is connected to the controller to transmit the signal to the controller, the controller is connected to the proportional switch of the Ith continuously variable motor to control the displacement of the Ith continuously variable motor according to the signal of the Ith displacement sensor, the Ith continuously variable motor is connected to the Ith hydraulic motor-mechanical linear actuator to control the extension or retraction of the actuator and the speed of action.

[0006] The first hydraulic motor-mechanical linear actuator includes a reducer, rolling bearings, balls, nuts, screws and push rods; the actuator is a new type of actuator, one side of the reducer is connected to the motor through a coupling, and the other side is connected to the screw through a coupling, the rolling bearing is sleeved on the screw, the balls are fitted between the screw and the nut, the nut is connected to the push rod, the hydraulic motor drives the reducer, the reducer drives the screw to make a rotational motion, and the screw causes the balls to push the nut to make a linear motion, thereby realizing the extension and retraction of the push rod and the speed of the movement.

[0007] The oil inlets at both ends of the shuttle valve are respectively connected to the oil outlets of the pressure compensating valves of the first load-sensitive control circuit and the second load-sensitive control circuit, so as to compare the maximum pressure output by the two circuits. The oil outlet of the shuttle valve is respectively connected to the control oil outlets of the pressure compensating valves of the first load-sensitive control circuit and the second load-sensitive control circuit, so as to adjust the flow rate and control the pressure of the circuit. At the same time, the oil outlet of the shuttle valve is connected to the oil outlet at the other end of the bidirectional variable piston cylinder, and the displacement of the unidirectional variable pump is adjusted by changing the oil pressure of the two chambers of the bidirectional variable piston cylinder, thereby adjusting the flow rate of the system.

[0008] The first load-sensitive control circuit is the same as the second load-sensitive control circuit. The number of the load-sensitive control circuits is more than two and they are connected in parallel at the oil outlet of the one-way variable pump.

[0009] The input interface of the controller independently corresponds to the sensor signals of different loops, each sensor input signal independently corresponds to the output signal of the controller, and the independent output signal of the controller is connected with the proportional switch of different continuously variable motors.

[0010] The reducer is a gear reducer or a belt reducer.

[0011] The pressure compensating valve is a three-way pressure compensating valve, which has an overflow function.

[0012] The present invention has the following beneficial effects: The present invention provides a low throttling loss flow distribution control system, which specifically implements the use of a displacement sensor to detect the displacement of a valve core of a pressure compensation valve in a circuit, and feeds back a signal to a controller, which controls the motor speed to adjust the flow of the circuit. Especially when the interception loss is large, the valve core displacement is small, and increasing the flow can effectively reduce the interception loss, so that the system still has the function of flow distribution while accelerating the dynamic response speed of the system, thereby achieving the purpose of low throttling loss. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0014] Figure 1 It is a structural schematic diagram of a low throttling loss flow distribution control system in the embodiment of the present invention; Figure 2 It is a schematic diagram of the structure of two actuator circuits of a low throttling loss flow distribution control system in the embodiment of the present invention; Figure 3 It is a structural schematic diagram of an actuator loop of a low throttling loss flow distribution control system in the embodiment of the present invention; Figure 4 It is a structural schematic diagram of a new type of mechanical linear actuator of a low throttling loss flow distribution control system in this embodiment of the present invention.

[0015] Explanation of the reference numerals: 1-one-way variable pump; 2-oil tank; 3-two-way variable piston cylinder; 4-the first load-sensitive control circuit; 5-the second load-sensitive control circuit; 6-controller; 7-the first two-position two-way throttle valve; 8-the first pressure-compensating valve; 9-the first displacement sensor; 10-the first three-position four-way reversing solenoid valve; 11-the first continuous variable motor; 12-the first hydraulic motor-mechanical linear actuator; 13-the first shuttle valve; 14-reducer; 15-rolling bearing; 16-ball; 17-nut; 18-screw; 19-push rod. DETAILED DESCRIPTION

[0016] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0017] The purpose of the present invention is to use a displacement sensor to detect the displacement of the valve core of the pressure compensation valve in the circuit, and use a controller to control the motor speed to adjust the flow of the circuit, thereby reducing the throttling loss of the system and effectively improving the response speed of the system without affecting the flow distribution function of the system.

[0018] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0019] As attached Figure 1 As shown, a low throttling loss flow distribution control system includes a one-way variable pump 1, an oil tank 2, a two-way variable piston cylinder 3, a first load sensitive control loop 4, a second load sensitive control loop 5 and a controller 6 to form a load sensitive system loop.

[0020] Two load-sensitive control oil circuits are connected in parallel with the oil outlet of the one-way variable pump, and the two load-sensitive control oil circuits are connected by a shuttle valve. The oil inlet of the one-way variable pump is connected to the oil tank, and the oil port at one end of the two-way variable piston cylinder is connected to the oil outlet of the one-way variable pump, which is controlled by the displacement of the one-way variable pump. At the same time, the extension and retraction of the rod at this end controls the displacement of the one-way variable pump.

[0021] The first load-sensitive control circuit includes the first two-position two-way throttle valve 7, the first pressure compensation valve 8, the first displacement sensor 9, the first three-position four-way reversing solenoid valve 10, the first continuous variable motor 11, the first hydraulic motor-mechanical linear actuator 12 and the first shuttle valve 13. The oil inlet of the first two-position two-way throttle valve is connected to the oil outlet of the one-way variable pump, the oil outlet of the first two-position two-way throttle valve is connected to the oil inlet of the first pressure compensation valve, and the oil outlet of the first pressure compensation valve is connected to the P port of the first three-position four-way reversing solenoid valve. The pressure compensation valve used is a three-way pressure compensation valve, which is equivalent to the overflow valve. The A port and the B port of the first three-position four-way reversing solenoid valve are respectively connected to the two interfaces of the first continuous variable motor.

[0022] The first displacement sensor is connected to the first pressure compensation valve to detect the displacement of the valve core of the first pressure compensation valve. The other side of the first displacement sensor is connected to the controller to transmit the signal to the controller. The input interface of the controller independently corresponds to the sensor signals of different circuits. Each sensor input signal independently corresponds to the output signal of the controller. The independent output signal of the controller is connected to the proportional switch of the first continuously variable motor. The displacement of the first continuously variable motor is controlled according to the signal of the first displacement sensor. The first continuously variable motor is connected to the first hydraulic motor-mechanical linear actuator to control the extension or retraction of the actuator and the speed of movement.

[0023] The oil inlets at both ends of the shuttle valve are respectively connected to the oil outlets of the pressure compensating valves of the first load-sensitive control circuit and the second load-sensitive control circuit to compare the maximum output pressures of the two circuits. The oil outlets of the shuttle valve are respectively connected to the control oil outlets of the pressure compensating valves of the first load-sensitive control circuit and the second load-sensitive control circuit to adjust the flow and control the pressure of the circuit. At the same time, the oil outlet of the shuttle valve is connected to the oil outlet at the other end of the bidirectional variable piston cylinder. The displacement of the unidirectional variable pump is adjusted by changing the oil pressure in the two chambers of the bidirectional variable piston cylinder, thereby adjusting the flow of the system.

[0024] The first load-sensitive control circuit is the same as the second load-sensitive control circuit. There can be two or more circuits depending on the number of actuators required. They are connected in parallel at the oil outlet of the one-way variable pump. Each load-sensitive circuit is connected by a shuttle valve to compare the oil circuit with the maximum pressure.

[0025] As attached Figure 4 As shown, the first hydraulic motor-mechanical linear actuator includes a reducer 14, a rolling bearing 15, a ball 16, a nut 17, a lead screw 18 and a push rod 19. This actuator is a new type of actuator. One side of the reducer is connected to the motor through a coupling, and the other side is connected to the lead screw through a coupling. This reducer can be a gear reducer or a belt reducer. The rolling bearing is sleeved on the lead screw, the ball fits between the lead screw and the nut, and the nut is connected to the push rod. The hydraulic motor drives the reducer, the reducer drives the lead screw to make a rotary motion, and the lead screw makes the ball push the nut to make a linear motion, thereby realizing the extension and retraction of the push rod and the speed of the action.

[0026] As attached Figure 2 As shown in the figure, the system has only two loops working. When the pressure of the first load-sensitive control loop is low and the pressure of the second load-sensitive control loop is high, the displacement sensor detects that the valve core displacement of the first pressure compensation valve is small, the valve opening is small, and the throttling loss is large. The signal is fed back to the controller. The controller receives the signal and adjusts the continuous variable motor: Adjustment situation 1: The controller increases the speed of the first continuously variable motor, increases the opening of the first pressure compensation valve, and then increases the flow in the circuit and reduces the throttling loss of the system; Adjustment situation 2: The controller reduces the speed of the second continuously variable motor, thereby reducing the flow of the circuit and the opening of the second pressure compensation valve. At the same time, the pressure of the two circuits is compared through the shuttle valve and fed back to the two-way variable piston cylinder. The two-way variable piston cylinder controls the proportional switch of the one-way variable pump to reduce the displacement of the pump, thereby achieving the purpose of reducing the throttling loss of the system. When the pressure of the second load-sensitive control loop is low and the pressure of the first load-sensitive control loop is high, the implementation principle is the same. When the number of loops in the system is increased, the control principle is the same as the regulation principle.

[0027] As attached Figure 3 As shown, the system has only one actuator working. The displacement sensor detects the displacement of the valve core of the pressure compensation valve of the system and feeds the signal back to the controller. The controller receives the signal and adjusts the continuous variable motor or the one-way variable pump to make the continuous variable motor and the one-way variable pump work efficiently: Adjustment mode 1: When the pressure at the oil outlet of the one-way variable pump is low, the pump cannot work efficiently. The displacement of the valve core of the pressure compensation valve is large, detected by the displacement sensor, and the signal is transmitted to the controller. The controller adjusts the proportional switch of the one-way variable pump and the continuously variable motor, increases the displacement of the one-way variable pump, and reduces the speed of the continuously variable motor, so that the pump works efficiently. Adjustment mode 2: When the pressure at the continuously variable motor is low, it cannot be in an efficient working state. The displacement sensor detects that the valve core displacement of the pressure compensation valve is small, and transmits the signal to the controller. The controller adjusts the proportional switch of the one-way variable pump and the continuously variable motor, reduces the displacement of the one-way variable pump, and increases the speed of the continuously variable motor, so that the motor is in an efficient working state and reduces the throttling loss of the system.

Claims

1. A low throttling loss flow distribution control system, characterized in that: The invention comprises a one-way variable displacement pump (1), an oil tank (2), a two-way variable displacement piston cylinder (3), a first load-sensitive control circuit (4), a second load-sensitive control circuit (5) and a controller (6); the two load-sensitive control oil circuits are connected in parallel to the oil outlet of the one-way variable displacement pump, the oil inlet of the one-way variable displacement pump is connected to the oil tank, and the oil outlet at one end of the two-way variable displacement piston cylinder is connected to the oil outlet of the one-way variable displacement pump, and is controlled by the displacement of the one-way variable displacement pump. At the same time, the extension and retraction of the rod at the end controls the displacement of the one-way variable displacement pump. The first load-sensitive control circuit (4) comprises a first two-position two-way throttle valve (7), a first pressure compensation valve (8), a first displacement sensor (9), a first three-position four-way reversing solenoid valve (10), a first continuously variable motor (11), a first hydraulic motor-mechanical linear actuator (12) and a first shuttle valve (13); the oil inlet of the first two-position two-way throttle valve is connected to the oil outlet of the one-way variable pump, the oil outlet of the first two-position two-way throttle valve is connected to the oil inlet of the first pressure compensation valve, and the oil outlet of the first pressure compensation valve is connected to the P port of the first three-position four-way reversing solenoid valve. The A port and the B port of the first three-position four-way reversing solenoid valve are respectively connected to the two interfaces of the first continuously variable motor. The first displacement sensor is connected to the first pressure compensation valve to detect the displacement of the valve core of the first pressure compensation valve. The other side of the first displacement sensor is connected to the controller to transmit the signal to the controller. The controller is connected to the proportional switch of the first continuously variable motor to control the displacement of the first continuously variable motor according to the signal of the first displacement sensor. The first continuously variable motor is connected to the first hydraulic motor-mechanical linear actuator to control the extension or retraction of the actuator and the speed of movement.

2. A low throttling loss flow distribution control system according to claim 1, characterized in that: The first hydraulic motor-mechanical linear actuator (12) comprises a reducer (14), a rolling bearing (15), a ball (16), a nut (17), a lead screw (18) and a push rod (19); the actuator is a new type of actuator, one side of the reducer is connected to the motor through a coupling, and the other side is connected to the lead screw through a coupling, the rolling bearing is sleeved on the lead screw, the ball is fitted between the lead screw and the nut, and the nut is connected to the push rod. The hydraulic motor drives the reducer, the reducer drives the lead screw to perform a rotational motion, and the lead screw causes the ball to push the nut to perform a linear motion, thereby realizing the extension and retraction of the push rod and the speed of the movement.

3. A low throttling loss flow distribution control system according to claim 1, characterized in that: The oil inlets at both ends of the shuttle valve are respectively connected to the oil outlets of the pressure compensating valves of the first load-sensitive control circuit and the second load-sensitive control circuit, so as to compare the maximum pressure output by the two circuits. The oil outlet of the shuttle valve is respectively connected to the control oil outlets of the pressure compensating valves of the first load-sensitive control circuit and the second load-sensitive control circuit, so as to adjust the flow rate and control the pressure of the circuit. At the same time, the oil outlet of the shuttle valve is connected to the oil outlet at the other end of the bidirectional variable piston cylinder, and the displacement of the unidirectional variable pump is adjusted by changing the oil pressure of the two chambers of the bidirectional variable piston cylinder, thereby adjusting the flow rate of the system.

4. A low throttling loss flow distribution control system according to claim 1, characterized in that: The first load-sensitive control circuit is the same as the second load-sensitive control circuit. The number of the load-sensitive control circuits is more than two and they are connected in parallel at the oil outlet of the one-way variable pump.

5. A low throttling loss flow distribution control system according to claim 1, characterized in that: The input interface of the controller independently corresponds to the sensor signals of different loops, each sensor input signal independently corresponds to the output signal of the controller, and the independent output signal of the controller is connected with the proportional switch of different continuously variable motors.

6. A low throttling loss flow distribution control system according to claim 1, characterized in that: The reducer is a gear reducer or a belt reducer.

7. A low throttling loss flow distribution control system according to claim 1, characterized in that: The pressure compensating valve is a three-way pressure compensating valve, which has an overflow function.

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