A control method of a winch overload protection oil circuit

Abstract

The application provides a control method of winch overload protection oil circuit, which comprises the following steps: detecting the current overturning moment of the crane by a detection component when the rope is being released; controlling the second control reversing valve to reverse to make the A end and the P end communicate when the current overturning moment of the crane exceeds the pre-set overturning moment; controlling the hydraulic oil of the control oil circuit of the pilot operated relief valve and the second pilot operated relief valve to flow back to the oil tank through the second control relief valve; connecting the oil circuit between the oil inlet pipeline and the pilot operated relief valve and the oil return pipeline and the oil circuit between the oil inlet pipeline and the second pilot operated relief valve and the oil return pipeline; supplying the oil tank with oil through the first shuttle valve to the second control end of the first on-off valve, reversing the first on-off valve to control the first port and the second port to be disconnected; and controlling the hydraulic oil to flow to the oil return pipeline through the pilot operated relief valve and the second pilot operated relief valve, and then flow back to the oil inlet pipeline through the motor, so that the hydraulic oil realizes circulation.

Description

Technical Field

[0001] This invention relates to the field of winch control system technology, and specifically to a control method for a winch overload protection oil circuit. Background Technology

[0002] Lifting hydraulic systems are widely used in various lifting equipment. Existing lifting hydraulic systems typically only enable the lifting and lowering of cargo. However, when a fixed platform crane is performing lifting operations with a supply vessel, it requires rope retraction and release operations. Furthermore, the rope release must be stopped after reaching a certain point. During rope retraction, if the hook of the fixed platform crane accidentally gets caught on the supply vessel, and the supply vessel, unaware of this, begins to move or becomes uncontrollable, failure to quickly detach the rope from the lifting equipment could result in the crane or the entire platform being dragged down by the supply vessel, creating a serious safety hazard.

[0003] Chinese patent application No. 202122954349.7, published on June 7, 2022, discloses an overload protection hydraulic system for a winch, including an oil tank, an output valve group, an overload valve group, and a regulating valve group. The regulating valve group includes a hydraulically controlled directional valve and a regulating shuttle valve. The P end of the hydraulically controlled directional valve is connected to a multi-way valve via a three-way valve, and the control port of the hydraulically controlled directional valve is connected to one end of the regulating shuttle valve. The A end of the hydraulically controlled directional valve is connected to the output valve group, the T end of the hydraulically controlled directional valve is connected to the oil tank, and the B end of the hydraulically controlled directional valve is normally closed. The overload valve group includes an overload sequence valve, one end of which is connected to the output valve group, and the other end of which is connected to the third end of the regulating shuttle valve.

[0004] This document detects the pressure in the hydraulic oil circuit through a sequence valve. However, it only detects the oil pressure in the hydraulic oil circuit and cannot detect the current state of the crane. Therefore, it cannot guarantee whether the overturning moment of the crane is within a safe range. Consequently, it is difficult to ensure that the crane can quickly release the rope when it accidentally hooks a heavy object that cannot be lifted. Furthermore, it cannot quickly release the rope through multiple oil circuits when the hook hooks other heavy objects. Summary of the Invention

[0005] This invention provides a control method for the overload protection oil circuit of a winch. By detecting the overturning moment of the crane, the overturning moment of the crane is ensured to be within a safe range, thereby enabling the rapid formation of the internal circulation oil circuit. This ensures both rapid rope release and stable hydraulic circuit. Furthermore, by setting up multiple drainage oil circuits, the hydraulic oil can be rapidly drained in the oil circuit in emergency situations, enabling the winch to quickly release the wire rope and achieve emergency rope abandonment.

[0006] To achieve the above objectives, the technical solution of the present invention is: a control method for a winch overload protection oil circuit, which realizes a rapid rope release function during rope winding and a stop rope release function during normal rope release through the winch control system. Specific steps include:

[0007] (1) When the quick release function is performed in the rope retraction state, the hydraulic oil in the oil tank flows back to the oil tank through the oil inlet pipe, motor, return oil pipe and the first switch valve to realize the rope retraction operation.

[0008] (15) When reeling in the rope.

[0009] (16) The detection component detects the current overturning moment of the crane.

[0010] (161) The working radius of the crane is detected by tilt sensor.

[0011] (162) The tension of the wire rope in the winding state is measured by a force sensor.

[0012] (163) The terminal processor calculates the current overturning moment of the crane based on the working radius of the crane and the tension of the wire rope.

[0013] (17) When the current overturning moment of the crane exceeds the preset overturning moment.

[0014] (18) The terminal processor controls the second control reversing valve to switch so that terminal A is connected to terminal P.

[0015] (19) The oil tank outputs hydraulic oil to the control end of the second control switch valve through the second control directional valve, driving the second control switch valve to switch and connect the first port and the second port.

[0016] (110) The control hydraulic oil of the control oil circuit of the pilot-operated relief valve and the second pilot-operated relief valve is depressurized and flows back to the oil tank through the second control relief valve.

[0017] (2) When the hook accidentally snags an object that cannot be lifted.

[0018] (21) The first control reversing valve reverses to connect end A with end P.

[0019] (22) The oil tank outputs hydraulic oil to the control terminal of the first control switch valve through the first control reversing valve, driving the first control switch valve to reverse and connect the first port and the second port.

[0020] (23) The control hydraulic oil of the control oil circuit of the pilot-operated relief valve and the second pilot-operated relief valve is depressurized and flows back to the oil tank through the first control relief valve.

[0021] (3) The oil circuit between the oil inlet pipe and the pilot relief valve and the oil return pipe, as well as the oil circuit between the oil inlet pipe and the second pilot relief valve and the oil return pipe are connected.

[0022] (4) The oil tank feeds oil into the second control terminal of the first switch valve through the first shuttle valve. The first switch valve reverses and controls the first port and the second port to disconnect.

[0023] (5) The hydraulic oil cannot flow back to the oil tank from the return oil pipe. Instead, it flows to the return oil pipe through the pilot relief valve and the second pilot relief valve, and then flows back to the inlet oil pipe through the motor to achieve circulation, thereby driving the winch to quickly discard the rope.

[0024] (6) If it is necessary to stop releasing the rope in the rope-releasing state, the second control switch valve is opened, and the hydraulic oil in the oil tank is output to the control end of the first switch valve through the second and third ports of the first shuttle valve, so that the first switch valve is opened, and the hydraulic oil in the return oil line cannot be disconnected from the oil tank.

[0025] The winch control system includes an oil tank, a pilot-operated relief valve, a first switching valve, a first control valve group, a second control valve group, a first shuttle valve, a detection component, and a motor. The oil tank is connected to the oil inlet pipe, and the oil tank is connected to the oil tank through the first switching valve. A pilot-operated relief valve and a second pilot-operated relief valve are provided between the oil inlet pipe and the oil return pipe. The oil inlet end of the pilot-operated relief valve is connected to the oil inlet pipe, and the oil outlet end of the pilot-operated relief valve is connected to the oil return pipe; the oil inlet end of the second pilot-operated relief valve is connected to the oil inlet pipe, and the oil outlet end of the pilot-operated relief valve is connected to the oil return pipe.

[0026] The above method, when operating to lift a heavy object, is in the rope-retracting state. Oil from the oil tank enters the second control terminal of the first switching valve, driving the first switching valve to switch and control the first and second ports to disconnect. This prevents hydraulic oil from flowing back to the oil tank through the return pipe and instead flows to the second port of the motor. Simultaneously, the tilt sensor detects the crane's working radius, and the force sensor detects the tension of the wire rope during the rope-retracting state. The terminal processor calculates the crane's current overturning moment based on the crane's working radius and the wire rope tension, enabling accurate and reliable assessment of the actual overturning moment. This allows for rapid rope release during the rope-releasing process by controlling the second control valve to switch according to the actual crane overturning situation. The current overturning moment is compared with the preset overturning moment. When the current overturning moment of the crane exceeds the preset overturning moment, the terminal processor drives the second control valve to switch and connect the A end to the P end. The oil tank outputs hydraulic oil to the control end of the second control switch valve through the second control switching valve, causing the second control switch valve to switch and connect the first port and the second port of the second control switch valve. This causes the control hydraulic oil in the control oil circuit of the pilot-operated relief valve to flow back to the oil tank through the second control relief valve, thereby reducing the regulating pressure of the pilot-operated relief valve. At the same time, the terminal processor controls the pressure regulator in real time according to the overturning moment of the crane, thereby driving the relief pressure of the second control relief valve to... Adjustments are made to ensure the hydraulic oil pressure is neither too high nor too low, keeping the crane's overturning moment within a safe range. This allows for the rapid formation of the internal circulation oil circuit, ensuring both rapid rope release and hydraulic circuit stability. If the hook catches an object that cannot be unhooked during rope retraction, the first control directional valve is manually activated. This directional valve switches, connecting terminals A and P. The oil tank outputs hydraulic oil to the control terminal of the first control switch valve via the first control directional valve. This causes the first control switch valve to switch and connect its first and second ports. Consequently, the control hydraulic oil in the pilot-operated relief valve's control circuit flows back to the oil tank after being depressurized by the first control relief valve. The regulating pressure of the flow valve decreases. Because the oil pressure in the inlet pipe is greater than the regulating pressure of the pilot-operated relief valve, the pilot-operated relief valve is driven to open. This causes the hydraulic oil in the inlet pipe to be depressurized through the pilot-operated relief valve to the return pipe, thereby increasing the oil pressure in the return pipe. This makes the oil pressure at the end of the motor connected to the return pipe greater than the oil pressure at the end of the motor connected to the inlet pipe. Due to the overflow effect of the pilot-operated relief valve, a circulation loop is formed between the inlet pipe, the return pipe, and the motor through the pilot-operated relief valve. The oil tank continues to output hydraulic oil to the inlet pipe, which in turn increases the amount of hydraulic oil in the circulation loop. This increases the pressure difference between the two ends of the motor, thereby increasing the motor speed and enabling rapid rope release.Simultaneously, by setting a second pilot-operated relief valve, when it is necessary to increase the circulation speed of hydraulic oil, the second pilot-operated relief valve is opened, connecting the oil circuit between the inlet pipe, the second pilot-operated relief valve, and the return pipe. The hydraulic oil flows through the pilot-operated relief valve and the second pilot-operated relief valve to the return pipe, and then flows back to the inlet pipe via the motor, thus achieving circulation. By adding multiple connected oil circuits in the inlet and outlet pipes, the circulation of hydraulic oil is accelerated, thereby speeding up the winch's rope release. When it is necessary to stop rope release during the release process, the second control switch valve is opened. The hydraulic oil in the tank is output through the second and third ports of the first shuttle valve to the control end of the first switch valve, causing the first switch valve to open. This prevents the hydraulic oil in the return pipe from disconnecting from the tank. Emergency rope release during the rope reeling process and stopping rope release during the release process are achieved through the three ports of the first shuttle valve. The operation method is simple.

[0027] Furthermore, the first control valve group includes a first control switching valve, a first control directional valve, and a first control relief valve. The P and T ends of the first control directional valve are connected to the oil tank, the A end of the first control directional valve is connected to the control end of the first control switching valve, the first port of the first control switching valve is connected to the oil tank through the first control relief valve, and the second port of the first control switching valve is connected to the control oil circuit of the pilot-operated relief valve. The relief pressure of the first control relief valve is less than the control pressure of the control oil circuit of the pilot-operated relief valve.

[0028] The second control valve group includes a second control switching valve, a second control directional valve, and a second control relief valve. The output end of the second control directional valve is connected to the second port of the first shuttle valve and the control end of the second control switching valve. The input end of the second control switching valve is connected to the control oil circuit of the pilot-operated relief valve and the control oil circuit of the second pilot-operated relief valve. The drain pressure of the first control relief valve is less than the drain pressure of the second control relief valve.

[0029] The detection component is communicatively connected to the second control directional valve. The detection component includes an inclination sensor installed on the crane and a force sensor installed on the winch. The inclination sensor and the force sensor are connected to the control terminal of the second control directional valve through a terminal processor. A pressure regulator is also provided at the control terminal of the second control relief valve. The pressure regulator is communicatively connected to the terminal processor.

[0030] The second control terminal of the first switching valve is connected to the A terminal of the first control directional valve and the A terminal of the second control directional valve via the first shuttle valve. The first port of the first switching valve is connected to the second port of the motor via a return oil pipe. The second port of the first switching valve is connected to the oil tank via a return oil pipe. The first control terminal of the first switching valve is connected to the first port and the second port of the first switching valve. The second control terminal of the first switching valve is also connected to the oil tank via the first shuttle valve. The first control terminal of the first switching valve controls the first port and the second port of the first switching valve to connect. The second control terminal of the first switching valve controls the first port and the second port of the first switching valve to disconnect.

[0031] Furthermore, a second switching valve is provided between the oil inlet end of the pilot-operated relief valve and the oil inlet pipe. The first port of the second switching valve is connected to the oil inlet pipe, and the second port of the second switching valve is connected to the oil inlet end of the pilot-operated relief valve.

[0032] The above settings, by setting a second switching valve, ensure that the oil circuit between the oil inlet pipe and the pilot relief valve is opened only when the pilot relief valve is needed, thereby facilitating the control of the hydraulic system.

[0033] Furthermore, a balance valve assembly is provided on the oil inlet pipe. The balance valve assembly includes a balance relief valve and a balance check valve. The oil inlet end of the balance relief valve is connected to the first port of the motor through the oil inlet pipe, and the oil outlet end of the balance relief valve is connected to the hydraulic pump through the oil inlet pipe. The oil inlet end of the balance check valve is connected to the oil outlet end of the balance relief valve, and the oil outlet end of the balance check valve is connected to the oil inlet end of the balance relief valve.

[0034] The above settings, through the installation of a balance valve assembly, ensure stable hydraulic oil output from the inlet pipe.

[0035] Furthermore, a brake valve is also provided on the motor. The control end of the brake valve is connected to the oil inlet pipe and the oil outlet pipe through a brake reversing valve. The P end of the brake reversing valve is connected to the oil tank, and the A end of the brake reversing valve is connected to the control end of the brake valve. The control end of the brake reversing valve is connected to the oil inlet pipe and the oil outlet pipe.

[0036] The above setup connects the inlet and outlet oil pipes via the control terminal of the brake valve reversing valve. When the winch is to be started, the hydraulic oil in the inlet and outlet oil pipes flows to the control terminal of the brake valve reversing valve and controls the brake valve reversing valve to connect terminal A to terminal P. This causes the hydraulic oil output from the oil tank to flow to the control terminal of the brake valve, thereby driving the brake valve to open and facilitating motor rotation.

[0037] Furthermore, a spring is provided on the second control end of the first switching valve, and the hydraulic oil pressure at the second control end plus the spring pressure is greater than the hydraulic oil pressure at the first control end of the first switching valve.

[0038] The above configuration, by incorporating a spring, ensures that when the first switching valve is to be closed, the hydraulic oil pressure flowing from the oil tank to the second control end of the first switching valve, combined with the spring force, overcomes the hydraulic oil pressure at the first control end of the first switching valve, thereby driving the first switching valve to close and preventing the hydraulic oil from flowing back to the oil tank through the return oil pipe.

[0039] Furthermore, the P and T ends of the second control directional valve are connected to the oil tank, the A end of the second control directional valve is connected to the control end of the second control switch valve, the first port of the second control switch valve is connected to the oil tank through the second control relief valve, the first port of the first shuttle valve is connected to the A end of the first control directional valve and the A end of the second control directional valve, the second port of the first shuttle valve is connected to the oil tank, and the third port of the first shuttle valve is connected to the second control end of the first switch valve.

[0040] The above configuration, by placing a first shuttle valve between the second control terminal of the first switching valve and the A terminal of the first and second control directional valves, ensures that the hydraulic oil flowing from the second control directional valve to the second control terminal of the first switching valve does not conflict with the hydraulic oil flowing from the oil tank to the second control terminal of the first switching valve.

[0041] Furthermore, step (1) specifically includes: (11) the oil tank supplies oil to the oil inlet pipe through a hydraulic pump.

[0042] (12) The hydraulic oil flows through the inlet pipe to the first port of the motor.

[0043] (13) The hydraulic oil in the return oil pipeline flows to the first control end of the first switch valve to drive the first port and the second port of the first switch valve to connect.

[0044] (14) Hydraulic oil flows into the return oil pipe through the second port of the motor and then flows back to the oil tank through the return oil pipe to achieve circulation and drive the motor to rotate.

[0045] The above settings facilitate normal rope winding.

[0046] Furthermore, a third switching valve is provided between the oil inlet end of the second pilot-operated relief valve and the oil inlet pipe. The first port of the third switching valve is connected to the oil inlet pipe, and the second port of the third switching valve is connected to the oil inlet end of the pilot-operated relief valve.

[0047] The above settings, by setting a third switching valve, ensure that the oil circuit between the oil inlet pipe and the second pilot-operated relief valve is opened only when the second pilot-operated relief valve is needed, thereby facilitating the control of the hydraulic system.

[0048] Furthermore, after step (5), step (6) is also included: if it is necessary to stop releasing the rope in the rope-releasing state, the second control switch valve is opened, and the hydraulic oil in the oil tank is output to the control end of the first switch valve through the second port and the third port of the first shuttle valve, so that the first switch valve is opened, and the hydraulic oil in the return oil line cannot be disconnected from the oil tank.

[0049] The above settings, through the configuration of the second control switch valve, allow for convenient control of stopping the rope release. Attached Figure Description

[0050] Figure 1 This is a schematic diagram of the hydraulic system of the present invention.

[0051] Figure 2 for Figure 1 Enlarged view of point A in the middle.

[0052] Figure 3 for Figure 1 Hydraulic system connection diagram at point B.

[0053] Figure 4 This is a flowchart of the present invention.

[0054] Figure 5 This is a flowchart illustrating the operation of the detection component of the present invention. Detailed Implementation

[0055] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0056] like Figures 1-3As shown, a control method for a winch overload protection hydraulic circuit is disclosed. The winch control system enables rapid rope release during rope winding and stops rope release during normal rope release. The winch control system includes an oil tank 1, a pilot-operated relief valve 2, a first switching valve 3, a motor 4, a second pilot-operated relief valve, a detection component (not shown), a first control valve group, and a second control valve group. A hydraulic pump (not shown) is installed on the oil tank 1. The hydraulic pump is connected to the first port 41 of the motor 4 via an inlet pipe 11, and the second port 42 of the motor 4 is connected to the oil tank 1 via a return pipe 12. A pilot-operated relief valve 2 is installed between the inlet pipe 11 and the return pipe 12. The inlet end of the pilot-operated relief valve 2 is connected to the inlet pipe 11, and the outlet end of the pilot-operated relief valve 2... The first end is connected to the return oil pipeline 12; a first switching valve 3 is provided on the return oil pipeline 12. The first port of the first switching valve 3 is connected to the second port 42 of the motor 4 through the return oil pipeline 12. The second port of the first switching valve 3 is connected to the oil tank 1 through the return oil pipeline 12. The first control end 31 of the first switching valve 3 is connected to the first port and the second port of the first switching valve 3. The second control end 32 of the first switching valve 3 is connected to the oil tank. The first control end 31 of the first switching valve 3 controls the first port and the second port of the first switching valve 3 to connect. The second control end 32 of the first switching valve 3 controls the first port and the second port of the first switching valve 3 to disconnect. The oil inlet end of the second pilot-operated relief valve 6 is connected to the oil inlet pipeline 11. The oil outlet end of the pilot-operated relief valve 6 is connected to the return oil pipeline 12.

[0057] The first control valve group includes a first control switching valve 81, a first control directional valve 82, and a first control relief valve 83. The P and T ends of the first control directional valve 82 are connected to the oil tank 1. The A end of the first control directional valve 82 is connected to the control end 811 of the first control switching valve 81. The first port of the first control switching valve 81 is connected to the oil tank 1 through the first control relief valve 83. The second port of the first control switching valve 81 is connected to the control oil circuit 20 of the pilot-operated relief valve 2. The overflow pressure of the first control relief valve 83 is less than the control pressure of the control oil circuit 20 of the pilot-operated relief valve 2. In this embodiment, the control end 821 of the first control directional valve is connected to a control button (not shown in the figure) in the crane operator's cab via an external circuit. In case of emergency, the operator in the cab can press the control button to drive the first control directional valve to achieve reversal.

[0058] The second control valve assembly includes a second control switching valve 91, a second control directional valve 92, and a second control relief valve 93. The P and T terminals of the second control directional valve 92 are connected to the oil tank 1. The A terminal of the second control directional valve 92 is connected to the control terminal 911 of the second control switching valve 91. The first port of the second control switching valve 91 is connected to the oil tank 1 via the second control relief valve 93. The second port of the second control switching valve 91 is connected to the control oil circuit 20 of the pilot-operated relief valve 2. The relief pressure of the second control relief valve 93 is less than the control pressure of the control oil circuit 20 of the pilot-operated relief valve 2. The discharge pressure of the first control relief valve is less than the discharge pressure of the second control relief valve.

[0059] The detection component is communicatively connected to the second control directional valve 92. The detection component includes a tilt sensor mounted on the crane and a force sensor mounted on the winch. The tilt sensor and force sensor are connected to the control terminal of the second control directional valve 92 via a terminal processor. A pressure regulator 931 is also provided at the control terminal of the second control relief valve 93, and the pressure regulator 931 is communicatively connected to the terminal processor. In this embodiment, the terminal processor is a PLC or CPU, or other device used for information processing; its specific technology is existing and will not be elaborated further here.

[0060] A first shuttle valve 84 is provided between the second control terminal 32 of the first switching valve 3 and the A terminal of the first control directional valve 82 and the A terminal of the second control directional valve 92. The first port 841 of the first shuttle valve 84 is connected to the A terminal of the second control directional valve 92, the second port 842 of the first shuttle valve 84 is connected to the oil tank 1, and the third port 843 of the first shuttle valve 84 is connected to the second control terminal 32 of the first switching valve 3.

[0061] A first shuttle valve 84 is installed between the second control terminal 32 of the first switching valve 3 and the A terminal of the second control directional valve 92. During normal rope winding, hydraulic oil from the control tank 1 enters the second port 842 of the first shuttle valve 84. Since the second control switching valve 92 is closed, the first port 841 of the first shuttle valve 84 cannot supply oil. Therefore, the hydraulic oil in the tank 1 enters the second control terminal 32 of the first switching valve 3 through the second port 842, closing the first switching valve 3 and thus enabling the rope winding operation to be stopped. In case of emergency rope winding, the second control switching valve 92 is open, allowing hydraulic oil from the tank 1 to enter the first port 841 of the first shuttle valve 84 and then flow to the control terminal of the first switching valve 3, closing it and enabling emergency rope winding. This ensures that the hydraulic oil flowing from the second control directional valve 92 to the second control terminal 32 of the first switching valve 3 does not conflict with the hydraulic oil flowing from the tank 1 to the second control terminal 32 of the first switching valve 3.

[0062] A second switching valve 21 is provided between the oil inlet end of the pilot-operated relief valve 2 and the oil inlet pipe. The first port of the second switching valve 21 is connected to the oil inlet pipe 11, and the second port of the second switching valve 21 is connected to the oil inlet end of the pilot-operated relief valve 2. By setting the second switching valve 21, the oil passage between the oil inlet pipe 11 and the pilot-operated relief valve 2 is opened only when the pilot-operated relief valve 2 is needed, thereby facilitating the control of the hydraulic system.

[0063] A third switching valve 61 is provided between the oil inlet end of the second pilot-operated relief valve 6 and the oil inlet pipe 11. The first port of the third switching valve 61 is connected to the oil inlet pipe 11, and the second port of the third switching valve 61 is connected to the oil inlet end of the pilot-operated relief valve 6. By providing the third switching valve 61, the oil passage between the oil inlet pipe 11 and the second pilot-operated relief valve 6 is only opened when the second pilot-operated relief valve 6 is needed, thereby facilitating the control of the hydraulic system.

[0064] A balance valve assembly 5 is provided on the oil inlet pipe 11. The balance valve assembly 5 includes a balance relief valve 51 and a balance check valve 52. The oil inlet end of the balance relief valve 51 is connected to the first port 41 of the motor 4 through the oil inlet pipe 11, and the oil outlet end of the balance relief valve 51 is connected to the hydraulic pump through the oil inlet pipe 11. The oil inlet end of the balance check valve 52 is connected to the oil outlet end of the balance relief valve 51, and the oil outlet end of the balance check valve 52 is connected to the oil inlet end of the balance relief valve 51. By setting up the balance valve assembly 5, the hydraulic oil output of the oil inlet pipe 11 is stabilized.

[0065] like Figure 1 As shown, a brake valve 43 is also provided on the motor 4. The control end of the brake valve 43 is connected to the oil inlet pipe and the oil outlet pipe through a brake directional valve 44. The P end of the brake directional valve 44 is connected to the oil tank, the A end of the brake directional valve is connected to the control end of the brake valve, and the K end of the brake directional valve 44 is connected to the oil inlet pipe 11 and the oil outlet pipe 12. When the winch is to be started, the hydraulic oil in the oil inlet pipe 11 and the oil outlet pipe 12 flows to the control end of the brake directional valve 44 and controls the brake directional valve 44 to switch so that the A end connects to the P end. This causes the hydraulic oil output from the oil tank 1 to flow to the control end of the brake valve 43, thereby driving the brake valve 43 to open and facilitating the rotation of the motor 4.

[0066] like Figure 2As shown, a spring 33 is also provided on the second control end 32 of the first switching valve 3. The hydraulic oil pressure at the second control end 32 plus the pressure of the spring 33 is greater than the hydraulic oil pressure at the first control end 31 of the first switching valve 3. By setting the spring 33, when the first switching valve 3 is to be closed, the hydraulic oil pressure flowing from the oil tank 1 to the second control end 32 of the first switching valve 3 plus the elastic force of the spring 33 overcomes the hydraulic oil pressure at the first control end 31 of the first switching valve 3, thereby driving the first switching valve 3 to close, so that the hydraulic oil cannot flow back to the oil tank through the return oil pipe 12.

[0067] like Figures 4-5 As shown, a control method for a winch overload protection oil circuit includes the following steps:

[0068] (1) When the quick release function is performed in the rope retraction state, the hydraulic oil in the oil tank flows back to the oil tank through the oil inlet pipe, motor, return oil pipe and the first switch valve to realize the rope retraction operation.

[0069] (11) The oil tank supplies oil to the oil inlet pipe through a hydraulic pump.

[0070] (12) The hydraulic oil flows through the inlet pipe to the first port of the motor.

[0071] (13) The hydraulic oil in the return oil pipeline flows to the first control end of the first switch valve to drive the first port and the second port of the first switch valve to connect.

[0072] (14) Hydraulic oil flows into the return oil pipe through the second port of the motor and then flows back to the oil tank through the return oil pipe to achieve circulation and drive the motor to rotate.

[0073] (15) When reeling in the rope.

[0074] like Figure 5 As shown, (16) the detection component detects the current overturning moment of the crane.

[0075] (161) The working radius of the crane is detected by tilt sensor.

[0076] (162) The tension of the wire rope in the winding state is measured by a force sensor.

[0077] (163) The terminal processor calculates the current overturning moment of the crane based on the working radius of the crane and the tension of the wire rope. In this embodiment, the moment is calculated as the product of the working radius of the crane and the tension of the wire rope.

[0078] (17) When the current overturning moment of the crane exceeds the preset overturning moment.

[0079] (18) The terminal processor controls the second control reversing valve to switch so that terminal A is connected to terminal P.

[0080] (19) The oil tank outputs hydraulic oil to the control end of the second control switch valve through the second control directional valve, driving the second control switch valve to switch and connect the first port and the second port.

[0081] (110) The control hydraulic oil of the control oil circuit of the pilot-operated relief valve and the second pilot-operated relief valve is depressurized and flows back to the oil tank through the second control relief valve.

[0082] (2) When the hook accidentally snags an object that cannot be lifted.

[0083] (21) The first control reversing valve reverses to connect end A with end P.

[0084] (22) The oil tank outputs hydraulic oil to the control terminal of the first control switch valve through the first control reversing valve, driving the first control switch valve to reverse and connect the first port and the second port.

[0085] (23) The control hydraulic oil of the control oil circuit of the pilot-operated relief valve and the second pilot-operated relief valve is depressurized and flows back to the oil tank through the first control relief valve.

[0086] (3) The oil circuit between the oil inlet pipe and the pilot relief valve and the oil return pipe, as well as the oil circuit between the oil inlet pipe and the second pilot relief valve and the oil return pipe are connected.

[0087] (4) The oil tank feeds oil into the second control terminal of the first switch valve through the first shuttle valve. The first switch valve reverses and controls the first port and the second port to disconnect.

[0088] (5) The hydraulic oil cannot flow back to the oil tank from the return oil pipe. Instead, it flows to the return oil pipe through the pilot relief valve and the second pilot relief valve, and then flows back to the inlet oil pipe through the motor to achieve circulation, thereby driving the winch to quickly discard the rope.

[0089] (6) If it is necessary to stop releasing the rope in the rope-releasing state, the second control switch valve is opened, and the hydraulic oil in the oil tank is output to the control end of the first switch valve through the second and third ports of the first shuttle valve, so that the first switch valve is opened, and the hydraulic oil in the return oil line cannot be disconnected from the oil tank.

[0090] In this embodiment, the method for calculating the overturning moment of the crane is existing technology and will not be described in detail here.

[0091] In the normal rope-laying state, no oil enters the control end of the first switch valve 3, so oil enters the first control end 31 of the first switch valve 3, thereby opening the first switch valve 3. Since the first control switch valve is open, the hydraulic oil in the oil tank 1 cannot enter through the first port of the first shuttle valve, but can only enter through the second and third ports to the control end of the first switch valve 3, causing the first switch valve 3 to close. Thus, the hydraulic oil in the oil tank 1 enters through the return oil pipe, the motor, the inlet pipe, and then the oil tank to realize rope laying. When it is necessary to stop rope laying, oil is supplied to the second port of the first shuttle valve, so that oil enters the second control end through the second and third ports, thereby opening the first switch valve 3, thus disconnecting the rope laying circuit and stopping rope laying.

[0092] The working principle of this invention is as follows: When the rope is being wound up, hydraulic oil output from the oil tank 1 enters the inlet pipe 11 through the balance check valve 52, then passes through the motor 4 and returns to the oil tank 1 through the return pipe 12, circulating to achieve the rope winding operation. Simultaneously, a first switching valve 3 is installed on the return pipe 12. When the motor 4 is rotating normally, the oil tank 1 supplies hydraulic oil to the motor 4 through the inlet pipe 11, and the oil flows into the return pipe 12 through the motor 4. The hydraulic oil in the return pipe 12 flows to the first control terminal 31 of the first switching valve 3, thereby driving the first switching valve 3 to switch and connect the first port and the second port. This connects the return pipe 12 to the oil tank, allowing the hydraulic oil to flow back to the oil tank 1 for circulation. When lifting a heavy object, the oil tank 1 is in the rope winding state, and the hydraulic oil flows to the first control terminal 31 of the first switching valve 3. Oil enters the second control terminal 32 of the first switching valve 3, driving the first switching valve 3 to switch and control the first and second ports to disconnect. This prevents hydraulic oil from flowing back to the oil tank 1 from the return oil pipe 12, instead flowing to the second port 42 of the motor 4. Simultaneously, the tilt sensor detects the crane's working radius, and the force sensor detects the tension of the wire rope during the rope winding process. The terminal processor calculates the crane's current overturning moment based on the crane's working radius and the wire rope tension. By comparing the current overturning moment with a preset overturning moment, when the current overturning moment exceeds the preset moment, the terminal processor drives the second control valve to switch, connecting terminal A to terminal P. The oil tank then outputs hydraulic oil to the second control valve 92. The control terminal 911 of the second control switch valve 91 causes the second control switch valve 91 to switch and connect the first port and the second port of the second control switch valve 91. This causes the control hydraulic oil in the control oil circuit 20 of the pilot-operated relief valve 2 to be depressurized and flow back to the oil tank through the first control relief valve 83. This lowers the regulating pressure of the pilot-operated relief valve 2. Simultaneously, the terminal processor controls the pressure regulator in real time according to the overturning moment of the crane, thereby driving the relief pressure of the second control relief valve to adjust, ensuring that the hydraulic oil pressure is neither too high nor too low, and ensuring that the overturning moment of the crane is within a safe range. This enables the rapid formation of the internal circulation oil circuit, ensuring rapid rope release while maintaining hydraulic circuit stability. If the hook is in the rope retraction state... When hooked onto an object that cannot be unhooked, the first control directional valve is manually activated. The first control directional valve 82 switches to connect end A and end P. The oil tank outputs hydraulic oil to the control end 811 of the first control switch valve 81 through the first control directional valve 82, causing the first control switch valve 81 to switch and connect the first port and the second port of the first control switch valve 81. As a result, the control hydraulic oil in the control oil circuit 20 of the pilot-operated relief valve 2 is depressurized through the first control relief valve 83 and flows back to the oil tank. This reduces the regulating pressure of the pilot-operated relief valve 2. Since the oil discharge pressure of the first control relief valve is less than that of the second control relief valve, the regulating pressure of the pilot relief valve can be reduced to a greater extent, thereby making the oil discharge speed of the hydraulic oil circuit faster.Because the oil pressure in the inlet pipe 11 is greater than the regulating pressure of the pilot-operated relief valve 2, the pilot-operated relief valve 2 is driven to open. This causes the hydraulic oil in the inlet pipe 11 to be depressurized through the pilot-operated relief valve 2 and flow to the return pipe 12, thereby increasing the oil pressure in the return pipe 12. This results in the oil pressure at the end of the motor 4 connected to the return pipe 12 being greater than the oil pressure at the end of the motor connected to the inlet pipe 11. Furthermore, due to the overflow effect of the pilot-operated relief valve 2, a circulation loop is formed between the inlet pipe, the return pipe, and the motor through the pilot-operated relief valve. The oil tank continues to output hydraulic oil to the inlet pipe, further increasing the amount of hydraulic oil in the circulation loop. This increases the pressure difference across the motor 4, thereby increasing the motor 4's speed and enabling rapid rope release. Simultaneously, by setting a second pilot-operated relief valve, when it is necessary to increase the hydraulic oil circulation speed... When the hydraulic oil reaches the specified speed, the second pilot-operated relief valve opens, connecting the oil inlet pipe with the second pilot-operated relief valve and the return pipe. The hydraulic oil flows through the pilot-operated relief valve and the second pilot-operated relief valve to the return pipe, then flows back to the inlet pipe via the motor, thus achieving circulation. By adding multiple connecting oil lines to the inlet and outlet pipes, the circulation of hydraulic oil is accelerated, thereby speeding up the winch's rope release. When it is necessary to stop rope release during the release process, the first control switch valve is opened. The hydraulic oil in the tank is output through the second and third ports of the first shuttle valve to the control end of the first switch valve, causing the first switch valve to open. This prevents the hydraulic oil in the return pipe from disconnecting from the tank. Emergency rope release during the rope reeling process and stopping rope release during the release process are achieved through the three ports of the first shuttle valve. The operation method is simple.

Claims

1. A control method for a winch overload protection hydraulic circuit, wherein the winch control system enables rapid rope release during rope winding and stops rope release during normal rope release, characterized in that: The specific steps include: (1) When the quick release function is performed in the rope retraction state, the hydraulic oil in the oil tank flows back to the oil tank through the oil inlet pipe, motor, oil return pipe and the first switch valve to realize the rope retraction operation; (15) When reeling in the rope; (16) The detection component detects the current overturning moment of the crane; (161) The working radius of the crane is detected by the tilt sensor; (162) The tension of the wire rope in the rope winding state is measured by the force sensor; (163) The terminal processor calculates the current overturning moment of the crane based on the working radius of the crane and the tension of the wire rope; (17) When the current overturning moment of the crane exceeds the preset overturning moment; (18) The terminal processor controls the second control reversing valve to switch so that terminal A is connected to terminal P; (19) The oil tank outputs hydraulic oil to the control terminal of the second control switch valve through the second control reversing valve, driving the second control switch valve to reverse and connect the first port and the second port; (110) The control hydraulic oil of the control oil circuit of the pilot-operated relief valve and the second pilot-operated relief valve is depressurized and flows back to the oil tank through the second control relief valve. (2) When the hook accidentally snags an object that cannot be lifted; (21) The first control directional valve reverses to connect end A and end P; (22) The oil tank outputs hydraulic oil to the control end of the first control switch valve through the first control directional valve, driving the first control switch valve to reverse and connect the first port and the second port; (23) The control hydraulic oil of the control oil circuit of the pilot relief valve and the second pilot relief valve is depressurized through the first control relief valve and flows back to the oil tank. (3) The oil circuit between the oil inlet pipe and the pilot-operated relief valve and the oil return pipe, as well as the oil circuit between the oil inlet pipe and the second pilot-operated relief valve and the oil return pipe are connected; (4) The oil tank feeds oil into the second control terminal of the first switch valve through the first shuttle valve, and the first switch valve reverses and controls the first port and the second port to disconnect; (5) The hydraulic oil cannot flow back to the oil tank from the return oil pipe. Instead, it flows to the return oil pipe through the pilot relief valve and the second pilot relief valve, and then flows back to the inlet oil pipe through the motor to achieve circulation, thereby driving the winch to quickly discard the rope. The winch control system includes an oil tank, a pilot-operated relief valve, a first switching valve, a first control valve group, a second control valve group, a first shuttle valve, detection components, and a motor. The oil tank is connected to the oil inlet pipe, and the oil tank is connected to the oil tank via the first switching valve. A pilot-operated relief valve and a second pilot-operated relief valve are provided between the oil inlet pipe and the oil return pipe. The inlet end of the pilot-operated relief valve is connected to the oil inlet pipe, and the outlet end of the pilot-operated relief valve is connected to the oil return pipe. The inlet end of the second pilot-operated relief valve is connected to the oil inlet pipe, and the outlet end of the pilot-operated relief valve is connected to the oil return pipe. The first control valve group includes a first control switching valve, a first control directional valve, and a first control relief valve. The P end and T end of the first control directional valve... The first control valve group consists of a second control valve, a second control directional valve, and a second control relief valve. The first port of the first control directional valve is connected to the oil tank via a first control relief valve. The second port of the first control directional valve is connected to the control oil circuit of the pilot-operated relief valve. The second control valve group includes a second control directional valve, a second control directional valve, and a second control relief valve. The A port of the second control directional valve is connected to the control terminal of the second control directional valve. The P and T ports of the second control directional valve are connected to the oil tank. The input port of the second control directional valve is connected to the control oil circuit of the pilot-operated relief valve and the control oil circuit of the second pilot-operated relief valve. The output port of the second control directional valve is connected to the oil tank via the first control relief valve.

2. The control method for a winch overload protection oil circuit according to claim 1, characterized in that: The overflow pressure of the first control relief valve is less than the control pressure of the pilot-operated relief valve control oil circuit; The oil discharge pressure of the first control relief valve is less than the oil discharge pressure of the second control relief valve. The detection component is communicatively connected to the second control reversing valve. The detection component includes an inclination sensor installed on the crane and a force sensor installed on the winch. The inclination sensor and the force sensor are connected to the control terminal of the second control reversing valve through a terminal processor. A pressure regulator is also provided at the control terminal of the second control relief valve. The pressure regulator is communicatively connected to the terminal processor. The second control terminal of the first switching valve is connected to the A terminal of the first control directional valve and the A terminal of the second control directional valve via the first shuttle valve. The first port of the first switching valve is connected to the second port of the motor via a return oil pipe. The second port of the first switching valve is connected to the oil tank via a return oil pipe. The first control terminal of the first switching valve is connected to the first port and the second port of the first switching valve. The second control terminal of the first switching valve is also connected to the oil tank via the first shuttle valve. The first control terminal of the first switching valve controls the first port and the second port of the first switching valve to connect. The second control terminal of the first switching valve controls the first port and the second port of the first switching valve to disconnect.

3. The control method for a winch overload protection oil circuit according to claim 1, characterized in that: A second switching valve is provided between the oil inlet end of the pilot-operated relief valve and the oil inlet pipe. The first port of the second switching valve is connected to the oil inlet pipe, and the second port of the second switching valve is connected to the oil inlet end of the pilot-operated relief valve.

4. The control method for a winch overload protection oil circuit according to claim 1, characterized in that: A balance valve assembly is provided on the oil inlet pipe. The balance valve assembly includes a balance relief valve and a balance check valve. The oil inlet end of the balance relief valve is connected to the first port of the motor through the oil inlet pipe, and the oil outlet end of the balance relief valve is connected to the hydraulic pump through the oil inlet pipe. The oil inlet end of the balance check valve is connected to the oil outlet end of the balance relief valve, and the oil outlet end of the balance check valve is connected to the oil inlet end of the balance relief valve.

5. The control method for a winch overload protection oil circuit according to claim 1, characterized in that: A brake valve is also provided on the motor. The control end of the brake valve is connected to the oil inlet pipe and the oil outlet pipe through a brake reversing valve. The P end of the brake reversing valve is connected to the oil tank, and the A end of the brake reversing valve is connected to the control end of the brake valve. The control end of the brake reversing valve is connected to the oil inlet pipe and the oil outlet pipe.

6. The control method for a winch overload protection oil circuit according to claim 1, characterized in that: A spring is also provided on the second control end of the first switching valve. The hydraulic oil pressure at the second control end plus the pressure of the spring is greater than the hydraulic oil pressure at the first control end of the first switching valve.

7. The control method for a winch overload protection oil circuit according to claim 1, characterized in that: The first port of the second control switch valve is connected to the oil tank through the second control relief valve. The first port of the first shuttle valve is connected to the A end of the first control directional valve and the A end of the second control directional valve. The second port of the first shuttle valve is connected to the oil tank. The third port of the first shuttle valve is connected to the second control end of the first switch valve.

8. The control method for a winch overload protection oil circuit according to claim 7, characterized in that: Step (1) specifically includes: (11) The oil tank supplies oil to the oil inlet pipe through a hydraulic pump; (12) The hydraulic oil flows to the first port of the motor through the oil inlet pipe; (13) The hydraulic oil in the return oil pipeline flows to the first control end of the first switching valve to drive the first port and the second port of the first switching valve to connect. (14) Hydraulic oil flows into the return oil pipe through the second port of the motor and then flows back to the oil tank through the return oil pipe to achieve circulation and drive the motor to rotate.

9. The control method for a winch overload protection oil circuit according to claim 1, characterized in that: A third switching valve is provided between the oil inlet end of the second pilot-operated relief valve and the oil inlet pipe. The first port of the third switching valve is connected to the oil inlet pipe, and the second port of the third switching valve is connected to the oil inlet end of the pilot-operated relief valve.

10. The control method for a winch overload protection oil circuit according to claim 1, characterized in that: After step (5), step (6) is also included. If it is necessary to stop releasing the rope in the rope release state, the second control switch valve is opened. The hydraulic oil in the oil tank is output to the control end of the first switch valve through the second port and the third port of the first shuttle valve, so that the first switch valve is opened and the hydraulic oil in the return oil line cannot be disconnected from the oil tank.

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