Hydraulic thruster control circuit and control method for submersible

Abstract

The present invention relates to a control circuit and control method for a hydraulic thruster for a submersible, comprising a motor assembly and a control oil circuit connected to the motor assembly. The motor assembly comprises a motor body, a hydraulic control valve, and a variable mechanism. The return oil port and the leakage oil port of the motor body are connected to an oil tank. The control oil circuit comprises a constant-pressure variable pump, and the outlet of the constant-pressure variable pump is connected in parallel to a main pressure reducing valve and a proportional pressure reducing valve. The present invention uses a proportional pressure reducing valve to achieve thruster speed control, and based on the proportional valve, is equipped with other necessary control valve components to achieve thruster start / stop and forward / reverse rotation. The circuit structure is simple, reliable, compact, and highly resistant to contamination. The proportional valve operates in a position away from the neutral dead zone, and the control linearity is good.

Description

Technical Field

[0001] The present invention relates to the technical field of submersible control circuits, and in particular to a submersible hydraulic propeller control circuit and a control method. Background Art

[0002] Submersible propulsion systems can be divided into electric propulsion systems and hydraulic propulsion systems. Electric propulsion systems have a simple structure and high efficiency, and are mostly used in small and medium-power submersibles. Hydraulic propulsion systems have high power density, good speed regulation performance and are easy to achieve water depth compensation, and are mostly used in high-power submersibles.

[0003] The hydraulic propulsion system is divided into throttling control and displacement control. Throttling control adjusts the propeller speed by changing the opening of the hydraulic valve. The control method is simple, but the efficiency is low. Displacement control adjusts the speed by changing the displacement of the motor. There is no throttling loss and high efficiency.

[0004] In order to meet the response speed and response accuracy of the submersible, the submersible hydraulic propulsion system mostly adopts servo valve control, but the servo valve has strict requirements on the cleanliness of the fluid medium, large energy loss and high manufacturing cost, which makes the maintenance of the submersible hydraulic system require more time and money. The performance of the proportional valve is close to that of the servo valve, and it is not sensitive to oil contamination and works reliably, but its disadvantage is that there is a dead zone in the middle position. Summary of the Invention

[0005] In response to the shortcomings of the above-mentioned existing production technology, the applicant provides a rationally structured hydraulic thruster control circuit and control method for submersibles, which adopts a proportional valve to realize the displacement control of the motor, avoiding the shortcomings of the servo valve such as poor anti-pollution ability and high cost. At the same time, the proportional valve operates at a position away from the dead zone and has good linearity.

[0006] The technical solutions adopted in the present invention are as follows:

[0007] A hydraulic propulsion control circuit for a submersible includes a motor assembly and a control oil circuit connected to the motor assembly. The motor assembly includes a motor body, a hydraulic control valve, and a variable mechanism. The oil return port and the oil leakage port of the motor body are connected to the oil tank.

[0008] The control oil circuit includes a constant pressure variable pump, the outlet of which is connected to a main pressure reducing valve and a proportional pressure reducing valve.

[0009] The outlet of the main pressure reducing valve is connected in parallel to the inlet of the fixed throttle hole, the A port of the hydraulic control valve, the inlet of the motor body, and the rod chamber of the variable mechanism; the rodless chamber of the variable mechanism is connected to the B port of the hydraulic control valve.

[0010] The spring chamber of the main pressure reducing valve is connected in parallel to the outlet of the fixed throttle hole and the inlet of the start-stop control valve; the hydraulic control port of the start-stop control valve is connected to the outlet of the shuttle valve, and the outlet of the start-stop control valve returns to the oil tank.

[0011] The T port of the forward and reverse control valve is connected to the oil tank, the P port is connected to the outlet of the proportional pressure reducing valve, the A port is connected in parallel to the first inlet of the shuttle valve and the first hydraulic control port of the hydraulic control valve, and the B port is connected in parallel to the second inlet of the shuttle valve and the second hydraulic control port of the hydraulic control valve.

[0012] As a further improvement of the above technical solution:

[0013] In the initial state, the variable mechanism is in the middle position and the swash plate angle of the motor body is 0.

[0014] The spring setting pressure P1 of the main pressure reducing valve is lower than the starting pressure of the motor body.

[0015] The initial setting pressure P3 of the spring of the hydraulic control valve is 0.5-1 MPa higher than the setting pressure P2 of the spring of the start-stop control valve.

[0016] The condition for the motor body to start is that the motor body inlet pressure P is higher than the starting pressure.

[0017] The hydraulic control valve adopts a spring-centered hydraulic control valve. There is an A-type half bridge between the A port and the T port of the hydraulic control valve, and the B port is located in the middle of the half bridge.

[0018] A control process utilizing a hydraulic thruster control circuit for a submersible, wherein the motor assembly operates, includes the following steps:

[0019] Connect the forward and reverse control valve to the right position, adjust the proportional pressure reducing valve, and gradually increase the outlet pressure P4 of the proportional pressure reducing valve. When P4 is less than the spring setting pressure P2 of the start-stop control valve, connect the start-stop control valve to the upper position. After the outlet pressure oil of the constant pressure variable pump is reduced by the main pressure reducing valve, it returns to the oil tank through the fixed throttle hole and the start-stop control valve. At this time, the outlet pressure of the main pressure reducing valve is still P1, which is lower than the starting pressure of the motor body. The motor body does not run, and the constant pressure variable pump is in a constant pressure and small flow state.

[0020] Continue to adjust the proportional pressure reducing valve to increase the outlet pressure P4 of the proportional pressure reducing valve. When P4 is higher than the spring setting pressure P2 of the start-stop control valve, the start-stop control valve is connected in the lower position. At this time, the main pressure reducing valve does not play a pressure reducing role. The outlet and inlet of the main pressure reducing valve are fully connected, and the fluid resistance of the passage flowing through the main pressure reducing valve tends to 0. Since the outlet pressure P4 of the proportional pressure reducing valve is lower than the initial spring setting pressure P3 of the hydraulic control valve, the variable mechanism is still in the middle position, the displacement of the motor body is 0, and the motor body does not run.

[0021] Continue to adjust the proportional pressure reducing valve to increase the outlet pressure P4 of the proportional pressure reducing valve. When P4 is higher than the initial setting pressure P3 of the spring of the hydraulic control valve, the hydraulic control valve gradually moves from the middle position to the upper position, and the motor body exits the 0 displacement state and starts to rotate forward. Detect the speed of the motor body at this time, and adjust the outlet pressure P4 of the proportional pressure reducing valve in real time to make the speed of the motor body controllable. At this time, the constant pressure variable pump is in the maximum constant flow state, and the outlet pressure of the constant pressure variable pump is the load pressure of the motor body.

[0022] When the forward and reverse control valve is connected to the left position, adjust the proportional pressure reducing valve to gradually increase the outlet pressure P4 of the proportional pressure reducing valve. When P4 is less than the spring setting pressure P2 of the start-stop control valve, the start-stop control valve is connected to the upper position. The outlet pressure oil of the constant pressure variable pump is reduced by the main pressure reducing valve and returns to the oil tank through the fixed throttle hole and the start-stop control valve. At this time, the outlet pressure of the main pressure reducing valve is still P1, which is lower than the starting pressure of the motor body. The motor body does not run, and the constant pressure variable pump is in a constant pressure and small flow state.

[0023] Continue to adjust the proportional pressure reducing valve to increase the outlet pressure P4 of the proportional pressure reducing valve. When P4 is higher than the spring setting pressure P2 of the start-stop control valve, the start-stop control valve is connected in the lower position. At this time, the main pressure reducing valve does not play a pressure reducing role. The outlet and inlet of the main pressure reducing valve are fully connected, and the fluid resistance of the passage flowing through the main pressure reducing valve tends to 0. Since the outlet pressure P4 of the proportional pressure reducing valve is lower than the initial spring setting pressure P3 of the hydraulic control valve, the variable mechanism is still in the middle position, the displacement of the motor body is 0, and the motor body does not run.

[0024] Continue to adjust the proportional pressure reducing valve to increase the outlet pressure P4 of the proportional pressure reducing valve. When P4 is higher than the initial setting pressure P3 of the spring of the hydraulic control valve, the hydraulic control valve gradually moves from the middle position to the lower position, and the motor body exits the 0 displacement state and starts to reverse. Detect the speed of the motor body at this time, and adjust the outlet pressure P4 of the proportional pressure reducing valve in real time to make the speed of the motor body controllable. At this time, the constant pressure variable pump is in the maximum constant flow state, and the outlet pressure of the constant pressure variable pump is the load pressure of the motor body.

[0025] As a further improvement of the above technical solution:

[0026] The forward and reverse rotation principle of the motor assembly is: the variable mechanism starts from the initial neutral state,

[0027] The piston of the variable mechanism gradually extends. At this time, the swash plate angle is positive. The displacement of the motor body gradually increases as the piston extends. The P port of the motor body 8-3 is connected to high-pressure oil, and the motor body rotates forward.

[0028] When the piston rod of the variable mechanism retracts from the middle position, the swash plate angle is negative, and the displacement of the motor body gradually increases as the piston retracts. At this time, high-pressure oil is passed through the P port of the motor body, and the motor body reverses.

[0029] The balancing process of the hydraulic control valve is as follows:

[0030] When the hydraulic control valve gradually moves from the middle position to the upper position, the input hydraulic resistance of the A-type half-bridge decreases, the output hydraulic resistance increases, and the pressure at port B increases until the pressure at port B approaches the inlet pressure P of the motor body. At this time, the piston of the variable mechanism extends from the middle position until the force on the piston of the variable mechanism is restored to a balanced state.

[0031] When the hydraulic control valve gradually moves from the middle position to the lower position, the input hydraulic resistance of the A-type plate bridge gradually increases, the output hydraulic resistance gradually decreases, and the pressure at port B gradually decreases until the pressure at port B is close to the pressure in the oil tank. At this time, the piston of the variable mechanism gradually retracts from the middle position until the force on the piston of the variable mechanism is rebalanced.

[0032] The initial state of the motor body is: the forward and reverse control valve is connected to the oil circuit in the middle position; the start and stop control valve is connected in the upper position under the action of the spring;

[0033] The outlet pressure oil of the constant pressure variable pump is reduced by the main pressure reducing valve, flows through the fixed throttle hole and the start-stop control valve and returns to the oil tank. At this time, the outlet pressure of the main pressure reducing valve is P1, which is lower than the starting pressure of the motor body. The variable mechanism is in the middle position, the displacement of the motor body is 0, and the motor body does not run.

[0034] The constant pressure variable pump is in a constant pressure and small flow state, that is, an energy-saving state.

[0035] The beneficial effects of the present invention are as follows:

[0036] The present invention has a compact and reasonable structure and is easy to operate. The displacement of the motor is controlled by a proportional valve, thereby adjusting the speed of the motor. The proportional valve avoids the shortcomings of the servo valve, such as poor anti-pollution ability and high cost.

[0037] In the present invention, the proportional valve operates at a position away from the dead zone and has better linearity; the specific reason is: when the outlet pressure P4 of the proportional pressure reducing valve in the present invention is greater than P3, the motor body starts to operate in a forward and reverse state with controllable speed, P3=P2+0.5~1MPa, so the outlet pressure P4 of the proportional pressure reducing valve is not only greater than P3, but also greater than P2, so that the working pressure section in the oil circuit is away from the part of the proportional pressure reducing valve close to the dead zone, so the speed regulation of the entire motor is in the part of the proportional pressure reducing valve working curve with better linearity, thereby making the motor speed regulation easier to control. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 Schematic diagram of the hydraulic control system of the present invention.

[0039] Among them: 1. Constant pressure variable pump; 2. Main pressure reducing valve; 3. Fixed throttle; 4. Start-stop control valve; 5. Proportional pressure reducing valve; 6. Forward and reverse control valve; 7. Shuttle valve; 8. Motor assembly;

[0040] 8-1. Hydraulic control valve; 8-2. Variable mechanism; 8-3. Motor body. DETAILED DESCRIPTION

[0041] The specific embodiments of the present invention will be described below with reference to the accompanying drawings.

[0042] like Figure 1 As shown, the hydraulic thruster control circuit for a submersible in this embodiment includes a motor assembly 8 and a control oil circuit connected to the motor assembly 8. The motor assembly 8 includes a motor body 8-3, a hydraulic control valve 8-1, and a variable mechanism 8-2. The return oil port and the leakage oil port of the motor body 8-3 are connected to the oil tank.

[0043] The control oil circuit includes a constant pressure variable pump 1, the outlet of which is connected to a main pressure reducing valve 2 and a proportional pressure reducing valve 5.

[0044] The outlet of the main pressure reducing valve 2 is connected in parallel to the inlet of the fixed throttle hole 3, the A port of the hydraulic control valve 8-1, the inlet of the motor body 8-3, and the rod cavity of the variable mechanism 8-2; the rodless cavity of the variable mechanism 8-2 is connected to the B port of the hydraulic control valve 8-1.

[0045] The spring chamber of the main pressure reducing valve 2 is connected in parallel to the outlet of the fixed throttle hole 3 and the inlet of the start-stop control valve 4; the hydraulic control port of the start-stop control valve 4 is connected to the outlet of the shuttle valve 7, and the outlet of the start-stop control valve 4 is connected to the oil tank.

[0046] The T port of the forward and reverse control valve 6 is connected to the oil tank, the P port is connected to the outlet of the proportional pressure reducing valve 5, the A port is connected in parallel to the first inlet of the shuttle valve 7 and the first hydraulic control port of the hydraulic control valve 8-1, and the B port is connected in parallel to the second inlet of the shuttle valve 7 and the second hydraulic control port of the hydraulic control valve 8-1.

[0047] In the initial state, the variable mechanism 8-2 is in the middle position and the swash plate angle of the motor body 8-3 is 0.

[0048] The spring setting pressure P1 of the main pressure reducing valve 2 is less than the starting pressure of the motor body 8 - 3 .

[0049] The initial setting pressure P3 of the spring of the hydraulic control valve 8 - 1 is 0.5-1 MPa higher than the setting pressure P2 of the spring of the start-stop control valve 4 .

[0050] The hydraulic control valve 8-1 is a spring-centered hydraulic control valve 8-1. There is an A-type half bridge between the A port and the T port of the hydraulic control valve 8-1, and the B port is located in the middle of the half bridge.

[0051] In the control process of the hydraulic propulsion control circuit for a submersible according to claim 1, the operation of the motor assembly 8 includes the following steps:

[0052] The forward and reverse control valve 6 is connected to the right position, and the proportional pressure reducing valve 5 is adjusted to gradually increase the outlet pressure P4 of the proportional pressure reducing valve 5. When P4 is less than the spring setting pressure P2 of the start-stop control valve 4, the start-stop control valve 4 is connected to the upper position. The outlet pressure oil of the constant pressure variable pump 1 is reduced by the main pressure reducing valve 2 and returns to the oil tank through the fixed throttle hole 3 and the start-stop control valve 4. At this time, the outlet pressure of the main pressure reducing valve 2 is still P1, which is lower than the starting pressure of the motor body 8-3. The motor body 8-3 does not run, and the constant pressure variable pump 1 is in a constant pressure and small flow state.

[0053] Continue to adjust the proportional pressure reducing valve 5 to increase the outlet pressure P4 of the proportional pressure reducing valve 5. When P4 is higher than the spring setting pressure P2 of the start-stop control valve 4, the start-stop control valve 4 is connected in the lower position. At this time, the main pressure reducing valve 2 does not play a pressure reducing role. The outlet and inlet of the main pressure reducing valve 2 are fully connected, and the fluid resistance of the passage through the main pressure reducing valve 2 tends to 0. Since the outlet pressure P4 of the proportional pressure reducing valve 5 is lower than the initial spring setting pressure P3 of the hydraulic control valve 8-1, the variable mechanism 8-2 is still in the middle position, the displacement of the motor body 8-3 is 0, and the motor body 8-3 does not operate.

[0054] Continue to adjust the proportional pressure reducing valve 5 so that the outlet pressure P4 of the proportional pressure reducing valve 5 continues to increase. When P4 is higher than the initial setting pressure P3 of the spring of the hydraulic control valve 8-1, the hydraulic control valve 8-1 gradually moves from the middle position to the upper position, and the motor body 8-3 exits the 0 displacement state and starts to rotate forward. Detect the speed of the motor body 8-3 at this time, and adjust the outlet pressure P4 of the proportional pressure reducing valve 5 in real time to make the speed of the motor body 8-3 controllable. At this time, the constant pressure variable pump 1 is in the maximum constant flow state, and the outlet pressure of the constant pressure variable pump 1 is the load pressure of the motor body 8-3.

[0055] When the forward and reverse control valve 6 is connected to the left position, the proportional pressure reducing valve 5 is adjusted to gradually increase the outlet pressure P4 of the proportional pressure reducing valve 5. When P4 is less than the spring setting pressure P2 of the start-stop control valve 4, the start-stop control valve 4 is connected to the upper position. The outlet pressure oil of the constant pressure variable pump 1 is reduced by the main pressure reducing valve 2 and returns to the oil tank through the fixed throttle hole 3 and the start-stop control valve 4. At this time, the outlet pressure of the main pressure reducing valve 2 is still P1, which is lower than the starting pressure of the motor body 8-3. The motor body 8-3 does not run, and the constant pressure variable pump 1 is in a constant pressure and small flow state.

[0056] Continue to adjust the proportional pressure reducing valve 5 to increase the outlet pressure P4 of the proportional pressure reducing valve 5. When P4 is higher than the spring setting pressure P2 of the start-stop control valve 4, the start-stop control valve 4 is connected in the lower position. At this time, the main pressure reducing valve 2 does not play a pressure reducing role. The outlet and inlet of the main pressure reducing valve 2 are fully connected, and the fluid resistance of the passage through the main pressure reducing valve 2 tends to 0. Since the outlet pressure P4 of the proportional pressure reducing valve 5 is lower than the initial spring setting pressure P3 of the hydraulic control valve 8-1, the variable mechanism 8-2 is still in the middle position, the displacement of the motor body 8-3 is 0, and the motor body 8-3 does not operate.

[0057] Continue to adjust the proportional pressure reducing valve 5 to increase the outlet pressure P4 of the proportional pressure reducing valve 5. When P4 is higher than the initial setting pressure P3 of the spring of the hydraulic control valve 8-1, the hydraulic control valve 8-1 gradually moves from the middle position to the lower position, and the motor body 8-3 exits the 0 displacement state and starts to reverse. Detect the speed of the motor body 8-3 at this time, and adjust the outlet pressure P4 of the proportional pressure reducing valve 5 in real time to make the speed of the motor body 8-3 controllable. At this time, the constant pressure variable pump 1 is in the maximum constant flow state, and the outlet pressure of the constant pressure variable pump 1 is the load pressure of the motor body 8-3.

[0058] The principle of the forward and reverse rotation of the motor assembly 8 is as follows: the variable mechanism 8-2 starts from the initial neutral state,

[0059] The piston of the variable mechanism 8-2 gradually extends. At this time, the swash plate angle is positive. The displacement of the motor body 8-3 gradually increases as the piston extends. The P port of the motor body 8-3 is connected to high-pressure oil, and the motor body 8-3 rotates forward.

[0060] When the piston rod of the variable mechanism 8-2 retracts from the middle position, the swash plate angle is negative, and the displacement of the motor body 8-3 gradually increases as the piston retracts. At this time, high-pressure oil is passed through the P port of the motor body 8-3, and the motor body 8-3 reverses.

[0061] The working process of the hydraulic control valve 8-1 is as follows:

[0062] When the hydraulic control valve 8-1 gradually moves from the neutral position to the upper position, the input hydraulic resistance of the A-type half-bridge decreases, the output hydraulic resistance increases, and the pressure at port B increases until the pressure at port B approaches the inlet pressure P of the motor body 8-3. At this time, the piston of the variable mechanism 8-2 extends from the neutral position until the force on the piston of the variable mechanism 8-2 is restored to a balanced state.

[0063] When the hydraulic control valve 8-1 gradually moves from the middle position to the lower position, the input fluid resistance of the A-type plate bridge gradually increases, the output fluid resistance gradually decreases, and the pressure at port B gradually decreases until the pressure at port B is close to the pressure in the oil tank. At this time, the piston of the variable mechanism 8-2 gradually retracts from the middle position until the force on the piston of the variable mechanism 8-2 is rebalanced.

[0064] The initial state of the motor body 8-3 is: the forward and reverse control valve 6 is connected to the oil circuit in the middle position; the start-stop control valve 4 is connected to the upper position under the action of the spring;

[0065] The outlet pressure oil of the constant pressure variable pump 1 is reduced by the main pressure reducing valve 2, flows through the fixed throttle hole 3, and the start-stop control valve 4 back to the oil tank. At this time, the outlet pressure of the main pressure reducing valve 2 is P1, which is lower than the starting pressure of the motor body 8-3. The variable mechanism 8-2 is in the middle position, the displacement of the motor body 8-3 is 0, and the motor body 8-3 does not operate.

[0066] The constant pressure variable pump 1 is in a constant pressure and small flow state and a load sensitive state, that is, an energy-saving state.

[0067] The specific structure and principle of the present invention are as follows:

[0068] A control circuit for a hydraulic thruster used in a submersible comprises a motor and a control oil circuit thereof.

[0069] The control oil circuit includes: a constant pressure variable pump 1, a main pressure reducing valve 2, a fixed throttle hole 3, a start-stop control valve 4, a proportional pressure reducing valve 5, a forward and reverse control valve 6, and a shuttle valve 7.

[0070] The motor 8 is a variable motor, which includes the motor itself, a hydraulic control valve 8-1 and a variable mechanism 8-2. The variable mechanism 8-2 is a single-acting cylinder structure.

[0071] The connection relationship is: the outlet of the constant pressure variable pump 1 is connected to the inlet of the main pressure reducing valve 2 and the proportional pressure reducing valve 5,

[0072] The outlet of the main pressure reducing valve 2 is connected to the inlet of the fixed throttle hole 3, the port A of the hydraulic control valve 8-1, the inlet of the motor, and the rod chamber of the variable mechanism 8-2.

[0073] The spring chamber of the main pressure reducing valve 2 is connected to the outlet of the fixed throttle hole 3 and the inlet of the start-stop control valve 4;

[0074] The forward and reverse control valve 6 is a three-position four-way solenoid reversing valve. Port T is connected to the oil tank, port P is connected to the outlet of the proportional pressure reducing valve 5, port A is connected in parallel to the first inlet of the shuttle valve 7 and the first hydraulic control port of the hydraulic control valve 8-1, and port B is connected in parallel to the second inlet of the shuttle valve 7 and the second hydraulic control port of the hydraulic control valve 8-1.

[0075] The start-stop control valve 4 is a hydraulically controlled two-position two-way reversing valve, whose hydraulic control port is connected to the outlet of the shuttle valve 7, and the outlet returns to the oil tank;

[0076] The variable mechanism 8-2 is a single-acting cylinder type, and its rodless chamber is connected to the B port of the hydraulic control valve 8-1; the return oil port and leakage oil port of the motor 8 are directly connected to the oil tank.

[0077] The features of the motor assembly 8 are:

[0078] When the variable mechanism 8-2 is in the middle position, the motor swash plate angle is 0;

[0079] When the variable mechanism gradually extends from the neutral position, the swash plate angle is positive, and the motor displacement gradually increases. At this time, high-pressure oil is passed through the P port of the motor, and the motor rotates forward. Conversely, when the variable mechanism gradually retracts from the neutral position, the swash plate angle is negative, and the motor displacement gradually increases. At this time, high-pressure oil is passed through the P port of the motor, and the motor rotates reversely.

[0080] The hydraulic control valve 8-1 is a spring-centered hydraulic control valve, and its valve core structure has the following characteristics:

[0081] Between port A and port T is a type A half-bridge, and port B is located in the middle of the half-bridge; when the hydraulic control valve 8-1 gradually moves from the middle position to the upper position, the input fluid resistance of the type A half-bridge gradually decreases, the output fluid resistance gradually increases, and the pressure at port B gradually increases until it approaches the motor inlet pressure P. At this time, the variable mechanism 8-2 gradually extends from the middle position until the force on the piston of the variable mechanism 8-2 is balanced; when the hydraulic control valve 8-1 gradually moves from the middle position to the lower position, the input fluid resistance of the type A plate bridge gradually increases, the output fluid resistance gradually decreases, and the pressure at port B gradually decreases until it approaches the pressure in the oil tank. At this time, the variable mechanism 8-2 gradually retracts from the middle position until the force on the piston of the variable mechanism 8-2 is balanced again.

[0082] Based on the above structure, in one embodiment of the present invention:

[0083] The spring setting pressure P1 of the main pressure reducing valve 2 is a relatively low pressure, which needs to be lower than the starting pressure of the motor 8.

[0084] The spring setting pressure of the start-stop control valve 4 is P2.

[0085] The initial setting force of the spring of the hydraulic control valve 8-1 is P3, which is about 0.5-1MPa higher than P2.

[0086] The outlet pressure of proportional pressure reducing valve 5 is P4.

[0087] The initial state of the motor assembly 8 is:

[0088] The forward and reverse control valve 6 is connected in the middle position, and the start-stop control valve 4 is connected in the upper position under the action of the spring. The outlet pressure oil of the pump 1 is reduced by the main pressure reducing valve and returns to the oil tank through the fixed throttle hole 3 and the start-stop control valve 4. At this time, the outlet pressure of the main pressure reducing valve 2 is P1, which is lower than the starting pressure of the motor 8. The variable mechanism 8-2 is in the middle position, and the motor displacement is 0, so the motor does not run. At this time, the constant pressure variable pump 1 is in a constant pressure and low flow state, which can effectively save power.

[0089] When the hydraulic motor needs to rotate forward, its working principle is as follows:

[0090] Connect the forward and reverse control valve 6 to the right position, adjust the proportional pressure reducing valve 5, and gradually increase its outlet pressure P4. When it is less than P2, the start-stop control valve 4 is still connected to the upper position. After the outlet pressure oil of the pump 1 is reduced by the main pressure reducing valve 2, it returns to the oil tank through the fixed throttle hole 3 and the start-stop control valve 4. At this time, the outlet pressure of the main pressure reducing valve 2 is still P1, which is lower than the starting pressure of the motor 8. The motor does not run, and the constant pressure variable pump 1 is still in a constant pressure and small flow state.

[0091] Continue to adjust the proportional pressure reducing valve 5 to increase its outlet pressure P4. When it is higher than P2, the start-stop control valve 4 is connected to the lower position. At this time, the main pressure reducing valve 2 has no pressure reducing effect. Its outlet and inlet are fully connected. At this time, it is in a passage state and the fluid resistance is almost 0. However, at this time, because the outlet pressure P4 of the proportional pressure reducing valve 5 is still lower than the initial setting pressure P3 of the spring of the hydraulic control valve 8-1, the variable mechanism 8-2 is still in the middle position, the motor displacement is 0, and the motor still does not run.

[0092] Continue to adjust the proportional pressure reducing valve 5 so that its outlet pressure P4 continues to increase. When it is higher than P3, the hydraulic control valve 8-1 gradually moves from the middle position to the upper position, the motor exits the 0 displacement state, and starts to rotate forward. The speed of the motor 8 is detected by the sensor, and the outlet pressure P4 of the proportional pressure reducing valve 5 is adjusted in time to control the upward movement of the hydraulic control valve 8-1, thereby controlling the extension degree of the variable mechanism 8-2, and then controlling the displacement of the motor 8. At this time, the constant pressure variable pump 1 is in the maximum constant flow state, thereby realizing the speed regulation and control of the motor 8; at the same time, the outlet pressure of the constant pressure variable pump 1 is the load pressure of the motor 8, and there is no power waste.

[0093] When the forward and reverse control valve 6 is connected to the left position, the reverse speed of the motor 8 can be controlled in the same way. When the forward and reverse control valve 6 is connected to the left position, the proportional pressure reducing valve 5 is adjusted to gradually increase the outlet pressure P4 of the proportional pressure reducing valve 5. When P4 is less than the spring setting pressure P2 of the start-stop control valve 4, the start-stop control valve 4 is connected to the upper position, and the outlet pressure oil of the constant pressure variable pump 1 is reduced by the main pressure reducing valve 2, and then returns to the oil tank through the fixed throttle hole 3 and the start-stop control valve 4. At this time, the outlet pressure of the main pressure reducing valve 2 is still P1, which is lower than the starting pressure of the motor body 8-3. The motor body 8-3 does not run, and the constant pressure variable pump 1 is in a constant pressure and small flow state.

[0094] Continue to adjust the proportional pressure reducing valve 5 to increase the outlet pressure P4 of the proportional pressure reducing valve 5. When P4 is higher than the spring setting pressure P2 of the start-stop control valve 4, the start-stop control valve 4 is connected in the lower position. At this time, the main pressure reducing valve 2 does not play a pressure reducing role. The outlet and inlet of the main pressure reducing valve 2 are fully connected, and the fluid resistance of the passage through the main pressure reducing valve 2 tends to 0. Since the outlet pressure P4 of the proportional pressure reducing valve 5 is lower than the initial spring setting pressure P3 of the hydraulic control valve 8-1, the variable mechanism 8-2 is still in the middle position, the displacement of the motor body 8-3 is 0, and the motor body 8-3 does not operate.

[0095] Continue to adjust the proportional pressure reducing valve 5 to increase the outlet pressure P4 of the proportional pressure reducing valve 5. When P4 is higher than the initial setting pressure P3 of the spring of the hydraulic control valve 8-1, the hydraulic control valve 8-1 gradually moves from the middle position to the lower position, and the motor body 8-3 exits the 0 displacement state and starts to reverse. Detect the speed of the motor body 8-3 at this time, and adjust the outlet pressure P4 of the proportional pressure reducing valve 5 in real time to make the speed of the motor body 8-3 controllable. At this time, the constant pressure variable pump 1 is in the maximum constant flow state, and the outlet pressure of the constant pressure variable pump 1 is the load pressure of the motor body 8-3.

[0096] When P3=P2+0.5-1MPa and the outlet pressure P4 of the proportional pressure reducing valve 5 is greater than P3, the motor body starts to work in the forward and reverse state with controllable speed. Therefore, the working pressure section of the proportional pressure reducing valve 5 is far away from the part close to the dead zone of the proportional pressure reducing valve, and the speed adjustment of the entire motor is in the part with better linearity of the working curve of the proportional pressure reducing valve.

[0097] Through the above embodiment, it can be seen that when the motor 8 is in a non-operating state, the constant-pressure variable pump 1 is in a constant-pressure and low-flow state; when the motor rotates forward or reverse, the outlet pressure of the constant-pressure variable pump 1 is the motor working pressure, and the flow rate is the maximum flow rate, that is, the constant-pressure variable pump 1 operates in a load-sensitive state; there is no significant power waste in both states.

[0098] The above description is an explanation of the present invention, not a limitation of the present invention. The scope of the present invention is defined in the claims. Any modifications may be made within the scope of protection of the present invention.

Claims

1. A hydraulic thruster control circuit for a submersible, characterized by: The motor assembly (8) includes a motor assembly (8) and a control oil circuit connected to the motor assembly (8). The motor assembly (8) includes a motor body (8-3), a hydraulic control valve (8-1) and a variable mechanism (8-2). The oil return port and the oil leakage port of the motor body (8-3) are connected to the oil tank. The control oil circuit comprises a constant pressure variable pump (1), the outlet of the constant pressure variable pump (1) is connected in parallel to a main pressure reducing valve (2) and a proportional pressure reducing valve (5). The outlet of the main pressure reducing valve (2) is connected in parallel to the inlet of the fixed throttle hole (3), the A port of the hydraulic control valve (8-1), the inlet of the motor body (8-3), and the rod chamber of the variable mechanism (8-2); the rodless chamber of the variable mechanism (8-2) is connected to the B port of the hydraulic control valve (8-1). The spring chamber of the main pressure reducing valve (2) is connected in parallel to the outlet of the fixed throttle hole (3) and the inlet of the start-stop control valve (4); the hydraulic control port of the start-stop control valve (4) is connected to the outlet of the shuttle valve (7), and the outlet of the start-stop control valve (4) returns to the oil tank. The T port of the forward / reverse control valve (6) is connected to the oil tank, the P port is connected to the outlet of the proportional pressure reducing valve (5), the A port is connected in parallel to the first inlet of the shuttle valve (7) and the first hydraulic control port of the hydraulic control valve (8-1), and the B port is connected in parallel to the second inlet of the shuttle valve (7) and the second hydraulic control port of the hydraulic control valve (8-1).

2. The hydraulic thruster control circuit for a submersible according to claim 1, wherein: In the initial state, the variable mechanism (8-2) is in the middle position and the swash plate angle of the motor body (8-3) is 0.

3. The hydraulic thruster control circuit for a submersible according to claim 1, wherein: The spring setting pressure P1 of the main pressure reducing valve (2) is less than the starting pressure of the motor body (8-3).

4. The hydraulic thruster control circuit for a submersible according to claim 3, wherein: The initial setting pressure P3 of the spring of the hydraulic control valve (8-1) is 0.5-1 MPa higher than the setting pressure P2 of the spring of the start-stop control valve (4).

5. The hydraulic thruster control circuit for a submersible according to claim 1, wherein: The hydraulic control valve (8-1) adopts a spring-centered hydraulic control valve (8-1), an A-type half bridge is formed between the A port and the T port of the hydraulic control valve (8-1), and the B port is located in the middle of the half bridge.

6. A control process using the submersible hydraulic thruster control circuit according to claim 5, characterized in that: The operation of the motor assembly (8) includes the following steps: The forward and reverse control valve (6) is connected to the right position, and the proportional pressure reducing valve (5) is adjusted to gradually increase the outlet pressure P4 of the proportional pressure reducing valve (5). When P4 is less than the spring setting pressure P2 of the start-stop control valve (4), the start-stop control valve (4) is connected to the upper position. The outlet pressure oil of the constant pressure variable pump (1) is reduced by the main pressure reducing valve (2) and returns to the oil tank through the fixed throttle hole (3) and the start-stop control valve (4). At this time, the outlet pressure of the main pressure reducing valve (2) is still P1, which is lower than the starting pressure of the motor body (8-3). The motor body (8-3) does not operate, and the constant pressure variable pump (1) is in a constant pressure and small flow state. Continue to adjust the proportional pressure reducing valve (5) to increase the outlet pressure P4 of the proportional pressure reducing valve (5). When P4 is higher than the spring setting pressure P2 of the start-stop control valve (4), the start-stop control valve (4) is connected to the lower position. At this time, the main pressure reducing valve (2) does not play a pressure reducing role. The outlet and inlet of the main pressure reducing valve (2) are fully connected, and the fluid resistance of the passage flowing through the main pressure reducing valve (2) tends to 0. Since the outlet pressure P4 of the proportional pressure reducing valve (5) is lower than the initial setting pressure of the spring of the hydraulic control valve (8-1), the variable mechanism (8-2) is still in the middle position, the displacement of the motor body (8-3) is 0, and the motor body (8-3) does not operate. Continue to adjust the proportional pressure reducing valve (5) to increase the outlet pressure P4 of the proportional pressure reducing valve (5). When P4 is higher than the initial setting pressure P3 of the spring of the hydraulic control valve (8-1), the hydraulic control valve (8-1) gradually moves from the middle position to the upper position, and the motor body (8-3) exits the zero displacement state and starts to rotate forward. Detect the speed of the motor body (8-3) at this time, and adjust the outlet pressure P4 of the proportional pressure reducing valve (5) in real time to make the speed of the motor body (8-3) controllable. At this time, the constant pressure variable pump (1) is in the maximum constant flow state, and the outlet pressure of the constant pressure variable pump (1) is the load pressure of the motor body (8-3). When the forward and reverse control valve (6) is connected to the left position, the proportional pressure reducing valve (5) is adjusted to gradually increase the outlet pressure P4 of the proportional pressure reducing valve (5). When P4 is less than the spring setting pressure P2 of the start-stop control valve (4), the start-stop control valve (4) is connected to the upper position. The outlet pressure oil of the constant pressure variable pump (1) is reduced by the main pressure reducing valve (2) and returns to the oil tank through the fixed throttle hole (3) and the start-stop control valve (4). At this time, the outlet pressure of the main pressure reducing valve (2) is still P1, which is lower than the starting pressure of the motor body (8-3). The motor body (8-3) does not operate, and the constant pressure variable pump (1) is in a constant pressure and small flow state. Continue to adjust the proportional pressure reducing valve (5) to increase the outlet pressure P4 of the proportional pressure reducing valve (5). When P4 is higher than the spring setting pressure P2 of the start-stop control valve (4), the start-stop control valve (4) is connected to the lower position. At this time, the main pressure reducing valve (2) does not play a pressure reducing role. The outlet and inlet of the main pressure reducing valve (2) are fully connected, and the fluid resistance of the passage flowing through the main pressure reducing valve (2) tends to 0. Since the outlet pressure P4 of the proportional pressure reducing valve (5) is lower than the initial spring setting pressure P3 of the hydraulic control valve (8-1), the variable mechanism (8-2) is still in the middle position, the displacement of the motor body (8-3) is 0, and the motor body (8-3) does not operate. Continue to adjust the proportional pressure reducing valve (5) to increase the outlet pressure P4 of the proportional pressure reducing valve (5). When P4 is higher than the initial setting pressure P3 of the spring of the hydraulic control valve (8-1), the hydraulic control valve (8-1) gradually moves from the middle position to the lower position, and the motor body (8-3) exits the zero displacement state and starts to reverse. Detect the speed of the motor body (8-3) at this time, and adjust the outlet pressure P4 of the proportional pressure reducing valve (5) in real time to make the speed of the motor body (8-3) controllable. At this time, the constant pressure variable pump (1) is in the maximum constant flow state, and the outlet pressure of the constant pressure variable pump (1) is the load pressure of the motor body (8-3).

7. The control process according to claim 6, characterized in that The principle of the forward and reverse rotation of the motor assembly (8) is as follows: the variable mechanism (8-2) starts from the initial neutral state, The piston of the variable mechanism (8-2) gradually extends, and the swash plate angle is positive at this time. The displacement of the motor body (8-3) gradually increases as the piston extends. The P port of the motor body (8-3) is connected to high-pressure oil, and the motor body (8-3) rotates forward. When the piston rod of the variable mechanism (8-2) retracts from the neutral position, the swash plate angle is negative, and the displacement of the motor body (8-3) gradually increases as the piston retracts. At this time, high-pressure oil is passed through the P port of the motor body (8-3), and the motor body (8-3) reverses.

8. The control process according to claim 6, wherein: The balancing process of the hydraulic control valve (8-1) is as follows: When the hydraulic control valve (8-1) gradually moves from the middle position to the upper position, the input hydraulic resistance of the A-type half-bridge decreases, the output hydraulic resistance increases, and the pressure at port B increases until the pressure at port B approaches the inlet pressure P of the motor body (8-3). At this time, the piston of the variable mechanism (8-2) extends from the middle position until the force on the piston of the variable mechanism (8-2) is restored to a balanced state. When the hydraulic control valve (8-1) gradually moves from the middle position to the lower position, the input hydraulic resistance of the A-type half-bridge gradually increases, the output hydraulic resistance gradually decreases, and the pressure at port B gradually decreases until the pressure at port B approaches the pressure in the oil tank. At this time, the piston of the variable mechanism (8-2) gradually retracts from the middle position until the force on the piston of the variable mechanism (8-2) is rebalanced.

9. The control process according to claim 6, characterized in that: The initial state of the motor body (8-3) is: the forward and reverse control valve (6) is connected to the oil circuit in the middle position; the start-stop control valve (4) is connected in the upper position under the action of the spring; The outlet pressure oil of the constant pressure variable pump (1) is reduced in pressure by the main pressure reducing valve (2), flows through the fixed throttle hole (3), the start-stop control valve (4) and returns to the oil tank. At this time, the outlet pressure of the main pressure reducing valve (2) is P1, which is lower than the starting pressure of the motor body (8-3), and the variable mechanism (8-2) is in the middle position. The displacement of the motor body (8-3) is 0, and the motor body (8-3) does not operate. The constant pressure variable pump (1) is in a constant pressure and small flow state, that is, an energy-saving state.

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