A control method for a swing hydraulic system

Abstract

This invention provides a control method for a rotary hydraulic system, the specific steps of which include: S1 The oil tank outputs hydraulic oil to one port of the rotary motor through one of the first oil outlet or the second oil outlet; S2 A portion of the hydraulic oil flows to the control terminals of the first and second directional valves; S3 When the hydraulic oil pressure is greater than that of the first directional valve; (1) The first directional valve reverses, so that the P terminal of the first directional valve is connected to the A terminal; (2) The hydraulic oil flows to the first directional valve through the two-way valve; (3) The hydraulic oil flows to the control port of the two-way valve through the first directional valve; (4) The two-way valve opens, and the hydraulic oil flows to the other port of the rotary motor through the two-way valve; S4 When the hydraulic oil pressure is greater than that of the second directional valve; (6) The second directional valve reverses, so that the P terminal of the second directional valve is connected to the A terminal; (7) The hydraulic oil flows to the brake valve through the P terminal and the A terminal of the second directional valve; S5 The brake valve opens; the rotary motor reverses direction.

Description

Technical Field

[0001] This invention relates to the field of crane technology, and more specifically to a control method for a slewing hydraulic system. Background Technology

[0002] Currently, slewing cranes are typically installed on the legs of various offshore platforms. They are widely used due to their advantages such as small platform space occupation, compact structure, large lifting capacity, and long lifting radius. A slewing pile crane mainly consists of a base, a slewing platform, a lifting mechanism, and a hydraulic system. The slewing platform is rotatably mounted on the base, while the lifting mechanism is mounted on the slewing platform. Sufficient space is provided in the middle of both the base and the slewing platform to allow the pile legs to pass through. In small slewing pile cranes, the slewing platform and the base are usually connected by a slewing bearing. In large slewing pile cranes, the slewing platform and the base are connected by rollers. Specifically, a slewing support ring is set on the base, and multiple positive roller assemblies and multiple negative roller assemblies are set on the slewing platform. The slewing support ring is sandwiched between the rollers of the positive roller assemblies and the rollers of the negative roller assemblies. The positive roller assemblies are located above the slewing support ring, and the negative roller assemblies are located below the slewing support ring. When the slewing platform rotates, the rollers of both the positive roller assemblies and the negative roller assemblies roll on the surface of the slewing support ring.

[0003] When cranes are used on ships, the ship's movement on the sea surface, caused by waves, can lead to uneven crane positions, with one side higher than the other. If the crane is not used for a period of time, the hydraulic oil in the crane's slewing hydraulic system can easily flow back into the oil tank, resulting in a lack of oil in the slewing hydraulic system. In the existing hydraulic system control process, the slewing motor is generally not balanced by supplying oil when the crane needs to be started and turned. This makes it impossible to balance the slewing motor and reliably release the brake through the hydraulic system control. Summary of the Invention

[0004] This invention provides a control method for a rotary hydraulic system, which balances the rotary motor simply by controlling the oil supply mode of the rotary platform. The control method is simple and has high safety performance.

[0005] To achieve the above objectives, the technical solution of the present invention is: a control method for a rotary hydraulic system, the specific steps of which include:

[0006] The S1 oil tank outputs hydraulic oil to one of the ports of the rotary motor through either the first or second oil outlet.

[0007] S2: A portion of the hydraulic oil flows to the control terminals of the first and second directional valves.

[0008] S3 When the hydraulic oil pressure is greater than that of the first directional valve.

[0009] (1) The first directional valve reverses, so that the P end of the first directional valve is connected to the A end.

[0010] (2) The hydraulic oil flows to the first directional valve through the first or second port of the two-way valve.

[0011] (3) The hydraulic oil flows through the first directional valve to the control port of the two-way valve.

[0012] (4) When the two-way valve is opened, the hydraulic oil flowing to one port of the rotary motor flows to the other port of the rotary motor through the two-way valve.

[0013] (5) Hydraulic oil is present at both ports of the rotary motor.

[0014] S4 When the hydraulic oil pressure is greater than that of the second directional valve.

[0015] (6) The second directional valve reverses, so that the P end of the second directional valve is connected to the A end.

[0016] (7) The hydraulic oil flows to the brake valve through the P and A ends of the second directional valve.

[0017] The S5 brake valve opens; the rotary motor steers the direction.

[0018] The above method, by setting up a brake control oil circuit, allows hydraulic oil from the tank to flow through either the first or second outlet to one port of the rotary motor when steering control of the rotary motor is required. A portion of the hydraulic oil flows to the control terminals of the first and second directional valves. As the hydraulic oil pressure flowing to the first directional valve gradually increases and eventually exceeds its switching pressure, the first directional valve activates and reverses, connecting its P terminal to its A terminal. This allows hydraulic oil flowing to the rotary motor to pass through either the first or second port of the two-way valve, and then through the P and A terminals of the first directional valve to the control port of the two-way valve, thus opening the control port of the two-way valve. This allows hydraulic oil flowing to one port of the rotary motor to flow through the first and second ports of the two-way valve to the other port of the rotary motor. This ensures that both ports of the slewing motor have hydraulic oil, preventing spontaneous rotation during startup. Simultaneously, as the hydraulic oil pressure flowing to the control end of the second directional valve gradually increases and exceeds its switching pressure, the second directional valve activates and switches, connecting its P-end to its A-end. This allows hydraulic oil to flow through the second directional valve to the brake valve, releasing it and enabling the slewing motor to rotate. This achieves balanced oil supply to the slewing motor, and the control method is simple. Because the switching pressure of the first directional valve is lower than that of the second, the brake valve will not release until the hydraulic oil pressure reaches the required rotation speed of the slewing motor. This ensures that both ends of the slewing motor have hydraulic oil before the crane can rotate, resulting in higher safety performance.

[0019] Furthermore, the rotary hydraulic system includes a brake oil circuit and a brake control oil circuit; the brake oil circuit is connected to an oil tank, and a brake control oil circuit is provided between the oil tank and the brake oil circuit; the brake oil circuit includes a rotary motor and a brake valve, and a first oil outlet and a second oil outlet are provided at the oil inlet end of the oil tank. The first oil outlet is connected to the left rotation port of the rotary motor, and the second oil outlet is connected to the right rotation port of the rotary motor. The rotary motor is also connected to the oil return end of the oil tank, and a brake valve is provided on the rotary motor. The brake valve is connected to the brake control oil circuit.

[0020] The brake control oil circuit includes a first reversing valve, a second reversing valve, and a two-way valve. The first port of the two-way valve is connected to the right-turn port of the rotary motor, and the second port of the two-way valve is connected to the left-turn port of the rotary motor. The P terminal of the first reversing valve is connected to the first and second ports of the two-way valve. The T terminal of the first reversing valve is connected to the return port of the oil tank. The A terminal of the first reversing valve is connected to the control port of the two-way valve. The B terminal of the first reversing valve is normally closed, and the control terminal of the first reversing valve is connected to the inlet port of the oil tank. The P terminal of the second reversing valve is connected to the inlet port of the oil tank. The T terminal of the second reversing valve is connected to the return port of the oil tank. The A terminal of the second reversing valve is connected to the brake valve. The control terminal of the second reversing valve is also connected to the inlet port of the oil tank.

[0021] The switching oil pressure of the first directional valve is less than that of the second directional valve.

[0022] Step (2) specifically includes:

[0023] (21) When making a left turn.

[0024] (21.1) The hydraulic oil flows to the first directional valve through the second port of the two-way valve.

[0025] (22) When making a right turn.

[0026] (22.1) The hydraulic oil flows to the first directional valve through the first port of the two-way valve.

[0027] Step (4) specifically includes:

[0028] (41) When making a left turn.

[0029] (41.1) The hydraulic oil flowing to the left turn port of the rotary motor flows to the right turn port of the rotary motor through the two-way valve.

[0030] (42) When making a right turn.

[0031] (42.1) The hydraulic oil flowing to the right turn port of the rotary motor flows to the left turn port of the rotary motor through the two-way valve.

[0032] The above settings, by configuring the brake control oil circuit, ensure that the hydraulic oil flowing to one port of the rotary motor flows through the first and second ports of the two-way valve to the other port of the rotary motor. This ensures that both ports of the rotary motor have hydraulic oil, thereby preventing the rotary motor from rotating spontaneously when it starts.

[0033] Furthermore, a one-way throttle valve is provided between the A end of the second directional valve and the brake valve. The P end of the one-way throttle valve is connected to the A end of the second directional valve, and the A end of the one-way throttle valve is connected to the brake valve. Thus, by setting up the one-way throttle valve, the flow rate of hydraulic oil returning from the brake valve to the oil tank can be adjusted, thereby stabilizing the hydraulic oil return flow.

[0034] Furthermore, a first control shuttle valve is provided between the control end of the first directional valve and the oil inlet end of the oil tank. The first end of the first control shuttle valve is connected to the oil inlet end of the oil tank, the second port of the first control shuttle valve is connected to the control end of the first directional valve, and the third port of the first control shuttle valve is connected to the A end of the one-way throttle valve. Thus, when the hydraulic oil in the control end of the first directional valve needs to flow back to the oil tank, by connecting the second port of the first control shuttle valve to the third port, the hydraulic oil in the control end of the first directional valve can flow back to the oil tank through the one-way throttle valve.

[0035] Furthermore, a first control check valve is provided between the first and second ports of the two-way valve and the P end of the first directional valve. The oil inlet of the first control check valve is connected to the first and second ports of the two-way valve, and the oil outlet of the first control check valve is connected to the P end of the first directional valve. Through the first control check valve, the hydraulic oil flowing to the P end of the first directional valve can be prevented from flowing back into the two-way valve.

[0036] Furthermore, a balancing oil circuit is provided between the rotary motor and the oil tank; the balancing oil circuit includes a first balancing valve and a second balancing valve. The first balancing valve is provided between the left-hand rotation port of the rotary motor and the first oil outlet of the oil tank, and the second balancing valve is provided between the right-hand rotation port of the rotary motor and the second oil outlet of the oil tank. By integrating the two balancing valves to form a bidirectional balancing valve, the smoothness of the rotary start is ensured.

[0037] Furthermore, the first balancing valve includes a first overflow valve and a first check valve; the second balancing valve includes a second overflow valve and a second check valve, the oil outlet of the first overflow valve is connected to a first oil outlet through a first oil outlet pipe, and the oil inlet of the first overflow valve is connected to the left-hand rotation port of the rotary motor; the oil outlet of the second overflow valve is connected to a second oil outlet through a second oil outlet pipe, and the oil inlet of the second overflow valve is connected to the right-hand rotation port of the rotary motor.

[0038] The inlet of the first check valve is connected to the outlet of the first relief valve, and the outlet of the first check valve is connected to the inlet of the first relief valve; the inlet of the second check valve is connected to the outlet of the second relief valve, and the outlet of the second check valve is connected to the inlet of the second relief valve.

[0039] The control end of the first relief valve is connected to the second oil outlet pipe through a balance control pipeline; the control end of the second relief valve is connected to the first oil outlet pipe through a balance control pipeline; the control end of the first relief valve is also connected to the oil outlet end of the first check valve through a balance control pipeline; the control end of the second relief valve is also connected to the oil outlet end of the second check valve through a balance control pipeline.

[0040] The above configuration, by setting up a first relief valve and a second relief valve to form a two-way balance valve, can balance the hydraulic oil pressure in the first oil outlet pipe and the second oil outlet pipe, thereby regulating the oil pressure and flow rate of the hydraulic oil to the rotary motor, thus making the flow of hydraulic oil smooth.

[0041] Furthermore, a rotary control pipe is provided between the first and second oil outlet pipes. The inlet end of the rotary control pipe is connected to the first and second oil outlet pipes, and the outlet end of the rotary control pipe is connected to the control end of the first directional valve, the control end of the second directional valve, and the P end of the second directional valve. Step S2 specifically includes a portion of the hydraulic oil flowing through the rotary control pipe to the control ends of the first and second directional valves. By setting up the rotary control pipe, when the oil tank supplies hydraulic oil to the rotary motor, a portion of the hydraulic oil can flow through the rotary control pipe to the first and second directional valves, thereby controlling the start of the rotary motor.

[0042] Furthermore, a second control shuttle valve is provided between the first and second oil outlet pipes. The first port of the second control shuttle valve is connected to the first oil outlet pipe, the second port is connected to the second oil outlet pipe, and the third port is connected to the rotary control pipe. By setting the second control shuttle valve, hydraulic oil will not flow to the other oil outlet pipe when it flows from one of the oil outlet pipes to the rotary control pipe.

[0043] Furthermore, step S2 specifically includes that when hydraulic oil flows out through the first outlet pipe, the second control shuttle valve closes the second port, so that the first port and the third port are connected, allowing the hydraulic oil to flow to the rotary control pipe; when hydraulic oil flows out through the second outlet pipe, the second control shuttle valve closes the first port, so that the second port and the third port are connected. Attached Figure Description

[0044] Figure 1 A schematic diagram of the rotary hydraulic system for implementing the present invention.

[0045] Figure 2 for Figure 1 Enlarged view of point E in the middle.

[0046] Figure 3 for Figure 1 Enlarged view of point F in the middle.

[0047] Figure 4 This is a flowchart illustrating the control method of the rotary hydraulic system of the present invention. Detailed Implementation

[0048] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0049] like Figures 1 to 3 As shown, a rotary hydraulic system includes a brake oil circuit 1 and a brake control oil circuit 2. The brake oil circuit 1 is connected to an oil tank 3, and the brake control oil circuit 2 is provided between the oil tank 3 and the brake oil circuit 1. The brake oil circuit 1 includes a rotary motor 11 and a brake valve 12. The oil tank 3 has a first oil outlet 31 and a second oil outlet 32 ​​at the oil inlet end. The first oil outlet 31 is connected to the left rotation port C1 of the rotary motor 11, and the second oil outlet 32 ​​is connected to the right rotation port C2 of the rotary motor 11. The rotary motor 11 is also connected to the oil return end of the oil tank 3. The brake valve 12 is provided on the rotary motor 11 and is connected to the brake control oil circuit 2.

[0050] like Figure 2 As shown, the brake control oil circuit 2 includes a first reversing valve 21, a second reversing valve 22, and a two-way valve 23. The first port 231 of the two-way valve 23 is connected to the right-turn port C2 of the rotary motor 11, and the second port 232 of the two-way valve 23 is connected to the left-turn port C1 of the rotary motor 11. The P end of the first reversing valve 21 is connected to the first port 231 and the second port 232 of the two-way valve 23. The T end of the first reversing valve 21 is connected to the return end of the oil tank 3. The A end of the first reversing valve 21 is connected to the control port 233 of the two-way valve 23. The B end of the first reversing valve 21 is normally closed. The control end 211 of the first reversing valve 21 is connected to the inlet end of the oil tank 3. The P end of the second reversing valve 22 is connected to the inlet end of the oil tank 3. The T end of the second reversing valve 22 is connected to the return end of the oil tank 3. The A end of the second reversing valve 22 is connected to the brake valve 12. The control end 221 of the second reversing valve 22 is also connected to the inlet end of the oil tank 3.

[0051] The switching oil pressure of the first directional valve 21 is less than that of the second directional valve 22. In this embodiment, the oil pressure of the first directional valve 21 is 5 bar, and the oil pressure of the second directional valve 22 is 25 bar.

[0052] like Figure 2 As shown, a one-way throttle valve 24 is also provided between the A end of the second reversing valve 21 and the brake valve. The P end of the one-way throttle valve 24 is connected to the A end of the second reversing valve 21, and the A end of the one-way throttle valve 24 is connected to the brake valve 12. Thus, by setting the one-way throttle valve 24, the flow rate of hydraulic oil returning to the oil tank 3 in the brake valve 12 can be adjusted, thereby stabilizing the hydraulic oil return.

[0053] A first control shuttle valve 25 is also provided between the control end 211 of the first directional valve 21 and the oil inlet end of the oil tank 3. The first end 251 of the first control shuttle valve 25 is connected to the oil inlet end of the oil tank 3, the second port 252 of the first control shuttle valve 25 is connected to the control end 211 of the first directional valve 21, and the third port 253 of the first control shuttle valve 25 is connected to the A end of the one-way throttle valve 24. Thus, when the hydraulic oil in the control end 211 of the first directional valve 21 needs to flow back to the oil tank 3, by connecting the second port 252 of the first control shuttle valve 25 to the third port 253, the hydraulic oil in the control end 211 of the first directional valve can flow back to the oil tank 3 through the one-way throttle valve 24.

[0054] A first control check valve 26 is provided between the first port 231 and the second port 232 of the two-way valve 23 and the P end of the first directional valve 21. The oil inlet of the first control check valve 26 is connected to the first port 231 and the second port 232 of the two-way valve 23, and the oil outlet of the first control check valve 26 is connected to the P end of the first directional valve 21. Through the first control check valve 26, the hydraulic oil flowing to the P end of the first directional valve can be prevented from flowing back into the two-way valve 23.

[0055] like Figure 3 As shown, a balancing oil circuit 4 is also provided between the rotary motor 11 and the oil tank 3; the balancing oil circuit 4 includes a first balancing valve 41 and a second balancing valve 42. The first balancing valve 41 is provided between the left-hand rotation port C1 of the rotary motor 11 and the first oil outlet 31 of the oil tank 3, and the second balancing valve 42 is provided between the right-hand rotation port C2 of the rotary motor 11 and the second oil outlet 32 ​​of the oil tank 3. By integrating the two balancing valves to form a bidirectional balancing valve, the smoothness of the rotary start is ensured.

[0056] like Figure 3 As shown, the first balance valve 41 includes a first overflow valve 411 and a first check valve 412; the second balance valve 42 includes a second overflow valve 421 and a second check valve 422. The oil outlet of the first overflow valve 411 is connected to the first oil outlet 31 through the first oil outlet pipe V1, and the oil inlet of the first overflow valve 411 is connected to the left turn port 1C of the rotary motor 11; the oil outlet of the second overflow valve 421 is connected to the second oil outlet 32 ​​through the second oil outlet pipe V2, and the oil inlet of the second overflow valve 421 is connected to the right turn port C2 of the rotary motor 11.

[0057] The oil inlet of the first check valve 412 is connected to the oil outlet of the first relief valve 411, and the oil outlet of the first check valve 412 is connected to the oil inlet of the first relief valve 411; the oil inlet of the second check valve 422 is connected to the oil outlet of the second relief valve 421, and the oil outlet of the second check valve 422 is connected to the oil inlet of the second relief valve 421.

[0058] The control end of the first overflow valve 411 is connected to the second oil outlet pipe V2 through the balance control pipe 40; the control end of the second overflow valve 421 is connected to the first oil outlet pipe V1 through the balance control pipe 40; the control end of the first overflow valve 411 is also connected to the oil outlet end of the first check valve 412 through the balance control pipe 40; the control end of the second overflow valve 421 is also connected to the oil outlet end of the second check valve 422 through the balance control pipe 40.

[0059] The above configuration, by setting the first overflow valve 411 and the second overflow valve 412 to form a two-way balance valve, can balance the hydraulic oil pressure of the first oil outlet pipe V1 and the second oil outlet pipe V2, thereby regulating the oil pressure and flow rate of the hydraulic oil to the rotary motor 11, thus making the flow of hydraulic oil smooth.

[0060] like Figure 3 As shown, a rotary control pipe BR is provided between the first oil outlet pipe V1 and the second oil outlet pipe V2. The inlet end of the rotary control pipe BR is connected to the first oil outlet pipe V1 and the second oil outlet pipe V2, and the outlet end of the rotary control pipe BR is connected to the control end of the first directional valve 21, the control end of the second directional valve 22, and the P end of the second directional valve 22. By setting up the rotary control pipe BR, when the oil tank 3 supplies hydraulic oil to the rotary motor 11, a portion of the hydraulic oil can flow through the rotary control pipe BR to the first directional valve 21 and the second directional valve 22, thereby controlling the start of the rotary motor 11.

[0061] like Figure 3 As shown, a second control shuttle valve 27 is provided between the first oil outlet pipe V1 and the second oil outlet pipe V2. The first port 271 of the second control shuttle valve 27 is connected to the first oil outlet pipe V1, the second port 272 is connected to the second oil outlet pipe V2, and the third port 273 is connected to the rotary control pipe BR. By setting the second control shuttle valve 27, hydraulic oil will not flow to the other oil outlet pipe when it flows from one of the oil outlet pipes to the rotary control pipe.

[0062] like Figure 4 As shown, a control method for a rotary hydraulic system includes the following steps:

[0063] The S1 oil tank outputs hydraulic oil to one of the ports of the rotary motor through either the first or second oil outlet.

[0064] S11 When making a left turn.

[0065] The S11.1 oil tank outputs hydraulic oil to the left-hand rotation port of the rotary motor through the first oil outlet.

[0066] S12 When making a right turn.

[0067] The S12.1 oil tank outputs hydraulic oil to the right-hand rotation port of the rotary motor through the second oil outlet.

[0068] A portion of the hydraulic oil in S2 flows through the rotary control pipeline to the control terminals of the first and second directional valves.

[0069] S2.1 When hydraulic oil flows out through the first outlet pipe, the second control shuttle valve closes the second port, connecting the first port and the third port, and the hydraulic oil flows to the rotary control pipe.

[0070] S2.2 When hydraulic oil flows out through the second outlet pipe, the second control shuttle valve closes the first port, connecting the second and third ports, and the hydraulic oil flows to the rotary control pipe.

[0071] S3 When the hydraulic oil pressure is greater than that of the first directional valve.

[0072] (1) The first directional valve reverses, so that the P end of the first directional valve is connected to the A end.

[0073] (2) The hydraulic oil flows to the first directional valve through the first or second port of the two-way valve.

[0074] (21) When making a left turn.

[0075] (21.1) The hydraulic oil flows to the first directional valve through the second port of the two-way valve.

[0076] (22) When making a right turn.

[0077] (22.1) The hydraulic oil flows to the first directional valve through the first port of the two-way valve.

[0078] (3) The hydraulic oil flows through the first directional valve to the control port of the two-way valve.

[0079] (4) When the two-way valve is opened, the hydraulic oil flowing to one port of the rotary motor flows to the other port of the rotary motor through the two-way valve.

[0080] (41) When making a left turn.

[0081] (41.1) The hydraulic oil flowing to the left turn port of the rotary motor flows to the right turn port of the rotary motor through the two-way valve.

[0082] (42) When making a right turn.

[0083] (42.1) The hydraulic oil flowing to the right turn port of the rotary motor flows to the left turn port of the rotary motor through the two-way valve.

[0084] (5) Hydraulic oil is present at both ports of the rotary motor.

[0085] S4 When the hydraulic oil pressure is greater than that of the second directional valve.

[0086] (6) The second directional valve reverses, so that the P end of the second directional valve is connected to the A end.

[0087] (7) The hydraulic oil flows to the brake valve through the P and A ends of the second directional valve.

[0088] The S5 brake valve opens; the rotary motor steers the direction.

[0089] The working principle of this invention is as follows: By setting up a brake control oil circuit 2, when the rotation of the rotary motor 11 needs to be controlled, the hydraulic oil in the oil tank 3 flows to one of the ports of the rotary motor 11 through either the first outlet V1 or the second outlet V2. A portion of the hydraulic oil flows to the control terminals of the first directional valve 21 and the second directional valve 22. When the hydraulic oil pressure flowing to the first directional valve 21 gradually increases and eventually exceeds the switching pressure of the first directional valve 21, the first directional valve 21 is activated and reversed. This causes the P terminal of the first directional valve 21 to connect to the A terminal, thereby allowing the hydraulic oil flowing to the rotary motor 11 to flow through the first port 231 or the second port 232 of the two-way valve 23, passing through the P terminal and the A terminal of the first directional valve 21, into the control port of the two-way valve 23. This opens the control port of the two-way valve 23, allowing the hydraulic oil flowing to one of the ports of the rotary motor 11 to flow to the control terminal of the two-way valve 23 through the first port 231 and the second port 232. The other port of the rotary motor 11 allows hydraulic oil to be supplied to both ports of the rotary motor 11, ensuring that the rotary motor 11 does not rotate spontaneously when started. Simultaneously, as the hydraulic oil pressure flowing to the control end of the second directional valve 22 gradually increases and exceeds the directional valve 22's directional pressure, the second directional valve 22 activates and reverses, connecting its P end to its A end. This allows hydraulic oil to flow through the second directional valve 22 to the brake valve 12, thereby releasing the brake valve 12 and enabling the rotary motor 11 to rotate. This achieves balanced oil supply control for the rotary motor, and the control method is simple. Because the directional pressure of the first directional valve 21 is less than that of the second directional valve 22, the brake valve 12 will not be released until the hydraulic oil pressure reaches the required directional speed of the rotary motor 11. This ensures that the crane can only rotate when both ends of the rotary motor 11 are supplied with hydraulic oil, resulting in higher safety.

Claims

1. A control method of a swing hydraulic system, characterized by: The rotary hydraulic system includes a brake oil circuit and a brake control oil circuit; the brake oil circuit is connected to an oil tank, and a brake control oil circuit is provided between the oil tank and the brake oil circuit; the brake oil circuit includes a rotary motor and a brake valve, and a first oil outlet and a second oil outlet are provided at the oil inlet end of the oil tank. The first oil outlet is connected to the left rotation port of the rotary motor, and the second oil outlet is connected to the right rotation port of the rotary motor. The rotary motor is also connected to the oil return end of the oil tank, and a brake valve is provided on the rotary motor. The brake valve is connected to the brake control oil circuit. The brake control oil circuit includes a first reversing valve, a second reversing valve, and a two-way valve. The first port of the two-way valve is connected to the right-turn port of the rotary motor, and the second port of the two-way valve is connected to the left-turn port of the rotary motor. The P terminal of the first reversing valve is connected to the first and second ports of the two-way valve. The T terminal of the first reversing valve is connected to the return port of the oil tank. The A terminal of the first reversing valve is connected to the control port of the two-way valve. The B terminal of the first reversing valve is normally closed, and the control terminal of the first reversing valve is connected to the inlet port of the oil tank. The P terminal of the second reversing valve is connected to the inlet port of the oil tank. The T terminal of the second reversing valve is connected to the return port of the oil tank. The A terminal of the second reversing valve is connected to the brake valve. The control terminal of the second reversing valve is also connected to the inlet port of the oil tank. The reversing oil pressure of the first reversing valve is less than the reversing oil pressure of the second reversing valve; A first control check valve is provided between the first and second ports of the two-way valve and the P end of the first directional valve. The oil inlet of the first control check valve is connected to the first and second ports of the two-way valve, and the oil outlet of the first control check valve is connected to the P end of the first directional valve. The specific steps include: The S1 oil tank outputs hydraulic oil to one of the ports of the rotary motor through either the first or the second oil outlet. S2 A portion of the hydraulic oil flows to the control terminals of the first and second directional valves; S3 When the hydraulic oil pressure is greater than that of the first directional valve; (1) The first directional valve reverses, so that the P end of the first directional valve is connected to the A end; (2) The hydraulic oil flows to the first directional valve through the first or second port of the two-way valve; step (2) specifically includes: (21) When making a left turn; (21.1) The hydraulic oil flows to the first directional valve through the second port of the two-way valve; (22) When making a right turn; (22.1) The hydraulic oil flows to the first directional valve through the first port of the two-way valve; (3) The hydraulic oil flows through the first directional valve to the control port of the two-way valve; (4) The two-way valve opens, and the hydraulic oil flowing to one port of the rotary motor flows through the two-way valve to the other port of the rotary motor; step (4) specifically includes: (41) When making a left turn; (41.1) The hydraulic oil flowing to the left turn port of the rotary motor flows to the right turn port of the rotary motor through the two-way valve; (42) When making a right turn; (42.1) The hydraulic oil flowing to the right-hand port of the rotary motor flows to the left-hand port of the rotary motor through the two-way valve; (5) Hydraulic oil is present at both ports of the rotary motor; S4 When the hydraulic oil pressure is greater than that of the second directional valve; (6) The second directional valve reverses, so that the P end of the second directional valve is connected to the A end; (7) The hydraulic oil flows to the brake valve through the P and A ends of the second directional valve; The S5 brake valve opens; the rotary motor steers the direction.

2. The control method of a swing hydraulic system according to claim 1, characterized by: A one-way throttle valve is also provided between the A end of the second reversing valve and the brake valve. The P end of the one-way throttle valve is connected to the A end of the second reversing valve, and the A end of the one-way throttle valve is connected to the brake valve.

3. A control method of a swing hydraulic system according to claim 2, characterized by: A first control shuttle valve is also provided between the control end of the first reversing valve and the oil inlet end of the oil tank. The first end of the first control shuttle valve is connected to the oil inlet end of the oil tank, the second port of the first control shuttle valve is connected to the control end of the first reversing valve, and the third port of the first control shuttle valve is connected to the A end of the one-way throttle valve.

4. The control method of a swing hydraulic system according to claim 1, characterized by: A balancing oil circuit is also provided between the rotary motor and the oil tank; the balancing oil circuit includes a first balancing valve and a second balancing valve. The first balancing valve is provided between the left-hand rotation port of the rotary motor and the first oil outlet of the oil tank, and the second balancing valve is provided between the right-hand rotation port of the rotary motor and the second oil outlet of the oil tank.

5. A control method of a swing hydraulic system according to claim 4, characterized in that: The first balance valve includes a first overflow valve and a first check valve; the second balance valve includes a second overflow valve and a second check valve. The oil outlet of the first overflow valve is connected to the first oil outlet through a first oil outlet pipe, and the oil inlet of the first overflow valve is connected to the left-hand rotation port of the rotary motor. The oil outlet of the second overflow valve is connected to the second oil outlet through a second oil outlet pipe, and the oil inlet of the second overflow valve is connected to the right-hand rotation port of the rotary motor. The inlet of the first check valve is connected to the outlet of the first relief valve, and the outlet of the first check valve is connected to the inlet of the first relief valve; the inlet of the second check valve is connected to the outlet of the second relief valve, and the outlet of the second check valve is connected to the inlet of the second relief valve. The control end of the first relief valve is connected to the second oil outlet pipe through a balance control pipeline; the control end of the second relief valve is connected to the first oil outlet pipe through a balance control pipeline; the control end of the first relief valve is also connected to the oil outlet end of the first check valve through a balance control pipeline; the control end of the second relief valve is also connected to the oil outlet end of the second check valve through a balance control pipeline.

6. A control method of a swing hydraulic system according to claim 5, characterized in that: A rotary control pipe is provided between the first oil outlet pipe and the second oil outlet pipe. The oil inlet end of the rotary control pipe is connected to the first oil outlet pipe and the second oil outlet pipe, and the oil outlet end of the rotary control pipe is connected to the control end of the first directional valve, the control end of the second directional valve, and the P end of the second directional valve. Step S2 specifically includes a portion of the hydraulic oil flowing through the rotary control pipe to the control ends of the first directional valve and the second directional valve.

7. A control method of a swing hydraulic system according to claim 6, characterized in that: A second control shuttle valve is provided between the first oil outlet pipe and the second oil outlet pipe. The first port of the second control shuttle valve is connected to the first oil outlet pipe, the second port of the second control shuttle valve is connected to the second oil outlet pipe, and the third port of the second control shuttle valve is connected to the rotary control pipe.

8. The control method for a rotary hydraulic system according to claim 7, characterized in that: Step S2 further includes that when hydraulic oil flows out through the first outlet pipe, the second control shuttle valve closes the second port, so that the first port and the third port are connected, allowing the hydraulic oil to flow to the rotary control pipe; when hydraulic oil flows out through the second outlet pipe, the second control shuttle valve closes the first port, so that the second port and the third port are connected.

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