Winch automatic synchronization hydraulic system and control method
Patent Information
- Application Number
- PCT/CN2026/084202
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2025-03-25
- Filing Date
- 2026-03-18
- Publication Date
- 2026-10-01
Smart Images
Figure CN2026084202_01102026_PF_FP_ABST
Abstract
Description
An automatic synchronous hydraulic system and control method for winches Technical Field
[0001] This application relates to the field of forestry machinery technology, specifically to an automatic synchronous hydraulic system and control method for a winch. Background Technology
[0002] my country's forestry resources are widely distributed and the terrain is complex and varied. To expand the working range of forestry machinery, especially in steep mountainous areas, it is necessary to add a winch system. This system uses a winch and a steel cable to tow the machinery, which can then be pulled along steep terrain with insufficient traction. However, the winch system and the walking system are independent systems, which can easily lead to synchronization problems. Most existing winch systems are towing-type and cannot achieve bidirectional traction.
[0003] Chinese patent CN117621724A discloses a control method for a towing and rescue system, specifically a control method for a towing and rescue system with multiple winches. The controller, based on the pressure value at the hydraulic valve assembly, controls the current of the proportional valve at the output end according to a certain control strategy, changing the opening of the hydraulic proportional valve and thus altering the speed of the winches, maintaining the pressure difference between different winches within a specified range. This solution uses a throttling speed-regulating hydraulic system, which suffers from significant throttling losses and is only suitable for towing rescues, lacking an effective solution for lowering operations. Furthermore, while this solution can accurately control the speed by controlling the proportional valve, it cannot precisely control the torque of the winches, i.e., the tension of the wire rope. Summary of the Invention
[0004] The purpose of this application is to provide an automatic synchronous hydraulic system and control method for a winch. A variable displacement piston pump supplies oil to the winch system. By adjusting the set pressure of the first or second electro-proportional relief valve, the release or take-up rope tension of the winch is controlled respectively. The take-up or release rope speed is adjusted by controlling the opening of the electrically controlled load-sensitive valve in each direction. Two sets of solenoid valves work together to ensure that the winch's take-up or release rope speed is synchronized with the vehicle's travel speed while maintaining the tension of the wire rope, thereby ensuring the safe operation of the winch.
[0005] This application adopts the following technical solution to address the issue:
[0006] In a first aspect, this application provides an automatic synchronous hydraulic system for a winch, comprising a variable displacement piston pump, a pressure reducing valve, an electrically controlled load-sensitive valve, a variable displacement piston motor, a winch, a first electro-proportional relief valve, a second electro-proportional relief valve, a travel pump, and a travel motor. The P port of the variable displacement piston pump is connected to the I port of the pressure reducing valve, the I' port of the pressure reducing valve is connected to the P1 port of the electrically controlled load-sensitive valve, and the A port of the electrically controlled load-sensitive valve is connected to the A port of the variable displacement piston motor. When the A port of the variable displacement piston motor is used as a working port, it can drive the winch to lower the wire rope. The B port of the variable displacement piston motor is connected to the I port of the first electro-proportional relief valve, and the 2 port of the first electro-proportional relief valve is connected to the B port of the electrically controlled load-sensitive valve. By adjusting the first electro-proportional relief valve… The set pressure of the flow valve can control the back pressure of port B of the variable piston motor to adjust the rope release tension of the winch; port B of the electrically controlled load sensitive valve is connected to port B of the variable piston motor through the check valve of the first electro-proportional relief valve. When port B of the variable piston motor is used as the working oil port, it can drive the winch to retract the wire rope. Port 1 of the second electro-proportional relief valve is connected to the pilot port of the LS relief valve of port B of the electrically controlled load sensitive valve, and port 2 of the second electro-proportional relief valve is connected to port T2 of the electrically controlled load sensitive valve. By adjusting the set pressure of the second electro-proportional relief valve, the pressure of port B of the electrically controlled load sensitive valve can be controlled to control the rope retraction tension of the winch. Ports A and B of the travel pump are connected to ports A and B of the travel motor, respectively.
[0007] According to an example of this application, the A port of the variable piston motor is connected to the T3 port of the electronically controlled load sensitive valve through a replenishing check valve, and the flow direction of the replenishing check valve is from the T3 port of the electronically controlled load sensitive valve to the A port of the variable piston motor.
[0008] According to one example of this application, a shuttle valve is also included, wherein the X port of the variable piston pump is connected to the 3 port of the shuttle valve, the 1 port of the shuttle valve is connected to the LS port of the external working load sensitive valve, and the 2 port of the shuttle valve is connected to the LS port of the electrically controlled load sensitive valve 11.
[0009] According to one example of this application, port 2 of the pressure reducing valve is connected to the inlet of the external working oil circuit to provide hydraulic oil to the external working oil circuit; port 3 of the pressure reducing valve is connected to the oil tank.
[0010] According to one example of this application, it also includes an electromagnetic reversing valve, wherein the P port of the electromagnetic reversing valve is connected to the F port of the travel pump, and the A port of the electromagnetic reversing valve is connected to the brake oil port of the winch.
[0011] According to an example of this application, the solenoid directional valve has a left position and a right position. When the solenoid directional valve is in the left position, port A and port T of the solenoid directional valve are connected. When the solenoid directional valve is in the right position, port P and port A of the solenoid directional valve are connected. The hydraulic oil output from port A of the solenoid directional valve acts on the brake oil port of the winch to release the brake of the winch.
[0012] According to one example of this application, it also includes a tension sensor, an encoder, a speed sensor, and a controller. The tension sensor is used to detect the tension value of the wire rope. The encoder is used in conjunction with a timer to calculate the speed of winding or releasing the wire rope. The speed sensor is mounted on the travel motor to detect the motor speed and calculate the travel speed. The controller is configured to control the speed of the travel motor, the opening degree of the electronically controlled load-sensitive valve, the flow rate of the variable displacement piston pump, the set pressure of the first electro-proportional relief valve, or the set pressure of the second electro-proportional relief valve based on the tension value of the wire rope.
[0013] Secondly, this application also provides a control method for an automatic synchronized hydraulic system for a winch, which utilizes the aforementioned automatic synchronized hydraulic system for operation. The control method includes:
[0014] When the vehicle is not started, the winch is in the braking state, the variable piston motor is at its maximum displacement, neither port A nor port B of the electronically controlled load sensitive valve outputs hydraulic oil, the travel pump is at zero displacement, and the travel motor is at its maximum displacement.
[0015] After the vehicle is powered on and started, in response to the direction switch and throttle signal, the winch brake is released and the travel motor is started to drive the vehicle to move, and the vehicle's travel speed, the tension value of the wire rope, and the speed at which the winch takes in or releases the wire rope are obtained in real time.
[0016] Based on the tension value of the wire rope, determine the synchronization relationship between the vehicle's movement and the winch; based on the synchronization relationship between the vehicle's movement and the winch, adjust the vehicle's movement speed and the speed at which the winch winds up or releases the wire rope so that the tension value of the wire rope is maintained within a safe range.
[0017] If the difference between the vehicle's travel speed and the winch's speed of winding or releasing the wire rope exceeds the preset range, the winch will be braked, and the vehicle will stop moving simultaneously.
[0018] According to one example of this application, adjusting the vehicle's travel speed and the winch's speed of winding or releasing the wire rope based on the synchronization relationship between the vehicle's travel and the winch includes:
[0019] If the difference between the tension value of the wire rope and the lower limit of the safe range is lower than the danger threshold, the synchronization relationship between the vehicle's movement and the winch is determined to be that the speed at which the winch winds up or releases the wire rope is faster than the movement speed. In this case, the speed at which the winch winds up or releases the wire rope is reduced.
[0020] If the difference between the tension value of the wire rope and the upper limit of the safe range is lower than the danger threshold, the synchronization relationship between the vehicle movement and the winch is determined to be that the speed at which the winch pulls up or releases the wire rope is slower than the movement speed. In this case, the movement speed is reduced.
[0021] If the pull force of the winch exceeds the safe range, brake the winch and stop the vehicle from moving.
[0022] According to one example of this application, the adjustment of the walking speed is achieved by controlling the current through a proportional valve of the walking motor;
[0023] The speed at which the winch winds up or releases the wire rope is achieved by adjusting the opening of the electrically controlled load-sensitive valve or the flow rate of the variable piston pump.
[0024] If the winch is in the rope-releasing state, the set pressure of the first electro-proportional relief valve is adjusted to control the back pressure at port B of the variable piston motor, so as to adjust the rope-releasing tension of the winch. The adjustment of the set pressure of the first electro-proportional relief valve is achieved by adjusting the control current of the first electro-proportional relief valve.
[0025] If the winch is in the rope-reeling state, the set pressure of the second electro-proportional relief valve is adjusted to control the pressure at port B of the electrically controlled load sensitive valve, thereby adjusting the rope-reeling tension of the winch. The adjustment of the set pressure of the second electro-proportional relief valve is achieved by adjusting the control current of the second electro-proportional relief valve.
[0026] Compared with the prior art, this application has the following advantages:
[0027] This application determines the synchronization between the winch's winding and unwinding of the wire rope and the vehicle's movement based on the wire rope's tension value. By controlling the set pressure of the first and second electro-proportional relief valves and the opening degree of the electrically controlled load-sensitive valve, it can specifically adjust the tension and speed of winding or unwinding the wire rope in real time, thereby keeping the wire rope's tension value within a safe range and ensuring stable synchronization between the winding and unwinding of the wire rope and the vehicle's movement. Furthermore, this application can also achieve bidirectional traction ratio adjustment of the winch wire rope by controlling the direction of the electrically controlled load-sensitive valve and the displacement of the variable piston motor. It can also adjust the vehicle's movement speed by adjusting the displacement of the travel pump, further ensuring stable synchronization between the wire rope and the vehicle's movement and the safety of the wire rope's traction. Attached Figure Description
[0028] Figure 1 is a schematic diagram of the automatic synchronous hydraulic system for the winch in Example 1;
[0029] Figure 2 is a partial structural schematic diagram of Figure 1;
[0030] Figure 3 is a partial structural schematic diagram of Figure 1;
[0031] Figure 4 is a control principle diagram of the automatic synchronous hydraulic system of the winch in Figure 1.
[0032] The following are the labels in the diagram: 1. Variable displacement piston pump; 2. Pressure reducing valve; 3. Shuttle valve; 4. Solenoid directional valve; 5. Winch; 6. Encoder; 7. Tension sensor; 8. Variable displacement piston motor; 9. Oil replenishment check valve; 10. First electro-proportional relief valve; 11. Electro-controlled load-sensitive valve; 12. Second electro-proportional relief valve; 13. Travel pump; 14. Speed sensor; 15. Travel motor. Detailed Implementation
[0033] In the description of this application, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this application. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more. In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art will understand the specific meaning of the above terms in this application based on the specific circumstances.
[0034] The present application will be further described below with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application, and should not be used to limit the scope of protection of the present application.
[0035] Example 1
[0036] Referring to Figures 1 to 3, this embodiment provides an automatic synchronous hydraulic system for a winch, which includes a variable displacement piston pump 1, a pressure reducing valve 2, an electrically controlled load-sensitive valve 11, a variable displacement piston motor 8, a winch 5, a first electro-proportional relief valve 10, a second electro-proportional relief valve 12, a travel pump 13, and a travel motor 15.
[0037] The variable displacement piston pump 1 has its P port connected to the 1 port of the pressure reducing valve 2, the 1' port of the pressure reducing valve 2 is connected to the P1 port of the electrically controlled load sensing valve 11, and the A port of the electrically controlled load sensing valve 11 is connected to the A port of the variable displacement piston motor 8. When the A port of the variable displacement piston motor 8 is used as a working port, it can drive the winch 5 to release the rope. The B port of the variable displacement piston motor 8 is connected to the 1 port of the first electro-proportional relief valve 10, and the 2 port of the first electro-proportional relief valve 10 is connected to the B port of the electrically controlled load sensing valve 11. By adjusting the set pressure of the first electro-proportional relief valve 10, the back pressure of the B port of the variable displacement piston motor 8 can be controlled to adjust the rope release tension of the winch 5. The B port of the electrically controlled load sensing valve 11 is connected to the first electro-proportional relief valve 10 via a check valve. Port B of the variable piston motor 8, when used as a working oil port, can drive the winch 5 to take in the rope. Port 1 of the second electro-proportional relief valve 12 is connected to the pilot port of the LS relief valve of port B of the electrically controlled load sensitive valve 11. Port 2 of the second electro-proportional relief valve 12 is connected to port T2 of the electrically controlled load sensitive valve 11. By adjusting the set pressure of the second electro-proportional relief valve 12, the pressure of port B of the electrically controlled load sensitive valve 11 can be controlled to control the rope pulling force of the winch 5. Ports A and B of the travel pump 13 are connected to ports A and B of the travel motor 15, respectively. In this embodiment, the travel pump 13 and the travel motor 15 are respectively a closed-loop electrically controlled travel pump and a closed-loop electrically controlled travel motor, forming a closed circuit.
[0038] Specifically, the purpose of the hydraulic system in this embodiment is to adjust the directional opening of the electrically controlled load sensitive valve 11 (i.e., the flow rate at port A or port B of the electrically controlled load sensitive valve 11), as well as the inlet oil pressure and return oil back pressure at port B of the electrically controlled load sensitive valve 11 (which correspond to the control of the rope winding and rope unwinding conditions, respectively. In this embodiment, the return oil back pressure and inlet oil pressure at port B of the electrically controlled load sensitive valve 11 are controlled by the set pressure of the first electro-proportional relief valve 10 and the second electro-proportional relief valve 12, respectively), so as to adjust the rope winding or unwinding operation of the winch 5 in real time (including rope winding speed adjustment and rope winding tension adjustment), so that the rope winding or unwinding speed of the winch 5 can correspond to the travel speed of the vehicle, thereby ensuring the safe operation of the winch 5. Referring to Figure 4, in this embodiment, the winch automatic synchronous hydraulic system further includes a tension sensor 7, an encoder 6, a speed sensor 14, and a controller. The tension sensor 7 is used to detect the tension value of the wire rope. In this embodiment, the tension sensor 7 is installed on the pin of the pulley, and the tension value of the wire rope is calculated based on the force on the pin. The encoder 6 is used in conjunction with a timer to calculate the speed of winding or unwinding the wire rope. The speed sensor 14 is installed on the travel motor 15 to detect the motor speed and calculate the travel speed. The controller is configured to control the speed of the travel motor 15, the opening degree of the electronically controlled load-sensitive valve 11, the flow rate of the variable displacement piston pump 1, the set pressure of the first electro-proportional relief valve 10, or the set pressure of the second electro-proportional relief valve 12 based on the tension value of the wire rope.
[0039] The tension of the wire rope is a key control target in this embodiment. Excessive or insufficient tension indicates a significant asynchrony between the vehicle's travel speed and the winch 5's rope-reeling / unreeling speed. If the wire rope tension is too low (below the lower limit of the preset safety range), the winch 5's rope-reeling / unreeling speed will exceed the travel speed. Without timely intervention, the wire rope may accumulate inside the vehicle frame, necessitating a reduction in the rope-reeling / unreeling speed or a faster travel speed. Conversely, if the wire rope tension is too high (above the upper limit of the preset safety range), the winch 5's rope-reeling / unreeling speed will be slower than the travel speed. Without timely intervention, this will affect the wire rope's lifespan and severely impact the normal operation of the winch 5. Therefore, in this embodiment, the automatic synchronous hydraulic system of the winch 5 can maintain the tension of the wire rope within a preset safety range by adjusting the set pressure of the first electro-proportional relief valve 10 or the second electro-proportional relief valve 12, thereby ensuring the safe use of the winch 5. Of course, the winding or unwinding speed of the winch 5 can also be adjusted by adjusting the opening of the electrically controlled load sensitive valve 11 or the flow rate of the variable piston pump 1. Coordinated control and adjustment can be performed according to the actual situation. However, the opening of the electrically controlled load sensitive valve 11 and the flow rate of the piston pump are adjustment methods that can be used for both winding and unwinding of the winch 5. In actual use, this may cause changes in other parameters. The set pressure of the first electro-proportional relief valve 10 or the second electro-proportional relief valve 12 is dedicated to the adjustment of the winding or unwinding speed of the winch 5 and will not affect the normal use of other devices.
[0040] In this embodiment, the A port of the variable piston motor 8 is connected to the T3 port of the electronically controlled load sensitive valve 11 through the oil replenishment check valve 9. The flow direction of the oil replenishment check valve 9 is from the T3 port of the electronically controlled load sensitive valve 11 to the A port of the variable piston motor 8, so as to prevent the motor from sucking in air when releasing the rope.
[0041] The pressure reducing valve 2 has port 2 connected to the inlet of the external working oil circuit, providing hydraulic oil to the external working oil circuit; port 3 of the pressure reducing valve 2 is connected to the oil tank. The hydraulic system also includes a shuttle valve 3. Port X of the variable displacement piston pump 1 is connected to port 3 of the shuttle valve 3, port 1 of the shuttle valve 3 is connected to port LS of the external working load sensitive valve, and port 2 of the shuttle valve 3 is connected to port LS of the electrically controlled load sensitive valve 11. The variable displacement piston pump 1 can then provide pressurized oil to the working oil circuit and the winch 5 system.
[0042] In addition, the hydraulic system also includes a solenoid directional valve 4. The P port of the solenoid directional valve 4 is connected to the F port of the travel pump 13, the A port of the solenoid directional valve 4 is connected to the brake oil port of the winch 5, and the T port of the solenoid directional valve 4 is connected to the hydraulic oil tank. The braking of the winch 5 can be controlled through the solenoid directional valve 4. Specifically, the solenoid directional valve 4 has a left position and a right position. When the solenoid directional valve 4 is not energized, it is in the left position, and its A port and T port are connected. When the solenoid directional valve 4 is energized, it is in the right position, and its P port and A port are connected. The hydraulic oil output from the A port of the solenoid directional valve acts on the brake oil port of the winch 5 to release the brake of the winch 5.
[0043] Example 2
[0044] This embodiment provides a control method for an automatic synchronous hydraulic system for a winch according to Embodiment 1. The control method includes:
[0045] Step S1: When the vehicle is not started, the winch 5 is in the braking state, the variable piston motor 8 is at its maximum displacement, the A and B ports of the electronically controlled load sensitive valve 11 do not output hydraulic oil, the travel pump 13 is at zero displacement, and the travel motor 15 is at its maximum displacement.
[0046] Step S2: After the vehicle is powered on and started, in response to the direction switch and throttle signal, the winch 5 brake is released and the travel motor 15 is started to drive the vehicle to move and the vehicle's travel speed, the tension value of the wire rope, and the speed at which the winch 5 pulls in or releases the wire rope are obtained in real time.
[0047] Step S3: Determine the synchronization relationship between the vehicle's movement and the winch 5 based on the tension value of the wire rope; adjust the vehicle's movement speed and the speed at which the winch 5 pulls in or releases the wire rope based on the synchronization relationship between the vehicle's movement and the winch 5, so that the tension value of the wire rope is maintained within a safe range.
[0048] Step S31: If the difference between the tension value of the wire rope and the lower limit of the safety range is lower than the danger threshold, determine that the synchronization relationship between the vehicle travel and the winch 5 is that the speed at which the winch 5 pulls in or releases the wire rope is faster than the travel speed. At this time, reduce the speed at which the winch 5 pulls in or releases the wire rope. Alternatively, the travel speed can be increased by increasing the displacement of the travel pump. Of course, the travel speed is related to the throttle signal. If the controller receives the throttle signal at this time, it can choose to increase the travel speed without adjusting the wire rope speed.
[0049] Step S32: If the difference between the tension value of the wire rope and the upper limit of the safe range is lower than the danger threshold, determine that the synchronization relationship between the vehicle's movement and the winch 5 is that the speed at which the winch 5 winds up or releases the wire rope is slower than the movement speed. In this case, reduce the movement speed; alternatively, increase the speed at which the winch 5 winds up or releases the wire rope. If the controller receives a throttle signal at this time, it is not suitable to reduce the movement speed. Instead, increase the speed at which the winch 5 winds up or releases the wire rope. Of course, for driving safety, it is best to choose to reduce the speed at which the winch 5 winds up or releases the wire rope and reduce the movement speed as much as possible for adjustment.
[0050] Step S33: If the tension value of the winch 5 exceeds the safe range, brake the winch 5 and stop the vehicle from moving.
[0051] Step S4: If the difference between the vehicle's traveling speed and the speed at which the winch 5 retracts or releases the wire rope exceeds a preset range, brake the winch 5 and stop the vehicle from moving.
[0052] In this embodiment, the walking speed is adjusted by controlling the current of the proportional valve of the walking motor 15. If the winch 5 is in the rope-releasing state, the set pressure of the first electro-proportional relief valve 10 and the opening of the electrically controlled load sensitive valve are adjusted to adjust the rope-releasing tension and the speed at which the winch 5 releases the wire rope. The adjustment of the set pressure of the first electro-proportional relief valve 10 is achieved by adjusting the control current of the first electro-proportional relief valve 10. If the winch 5 is in the rope-retracting state, the set pressure of the second electro-proportional relief valve 12 and the opening of the electrically controlled load sensitive valve are adjusted to adjust the rope-retracting tension and the speed at which the winch 5 retracts the wire rope. The adjustment of the set pressure of the second electro-proportional relief valve 12 is achieved by adjusting the control current of the second electro-proportional relief valve 12.
[0053] The above description is only a preferred embodiment of this application. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of this application, and these improvements and modifications should also be considered within the scope of protection of this application.
Claims
1. An automatic synchronous hydraulic system for a winch, wherein, The system includes a variable displacement piston pump (1), a pressure reducing valve (2), an electrically controlled load sensitive valve (11), a variable displacement piston motor (8), a winch (5), a first electro-proportional relief valve (10), a second electro-proportional relief valve (12), a travel pump (13), and a travel motor (15). The P port of the variable displacement piston pump (1) is connected to the 1 port of the pressure reducing valve (2), the 1' port of the pressure reducing valve (2) is connected to the P1 port of the electrically controlled load sensitive valve (11), and the A port of the electrically controlled load sensitive valve (11) is connected to the A port of the variable displacement piston motor (8). When the A port of the variable displacement piston motor (8) is used as a working oil port, it can drive the winch (5) to lower the wire rope. The B port of the variable displacement piston motor (8) is connected to the 1 port of the first electro-proportional relief valve (10), and the 2 port of the first electro-proportional relief valve (10) is connected to the B port of the electrically controlled load sensitive valve (11). By adjusting the first electro-proportional relief valve (10)... The set pressure can control the back pressure of port B of the variable piston motor (8) to adjust the rope release force of the winch (5); port B of the electrically controlled load sensitive valve (11) is connected to port B of the variable piston motor (8) through the check valve of the first electro-proportional relief valve (10). When port B of the variable piston motor (8) is used as the working oil port, it can drive the winch (5) to retract the wire rope; port 1 of the second electro-proportional relief valve (12) is connected to the pilot port of the LS relief valve of port B of the electrically controlled load sensitive valve (11), and port 2 of the second electro-proportional relief valve (12) is connected to port T2 of the electrically controlled load sensitive valve (11). By adjusting the set pressure of the second electro-proportional relief valve (12), the pressure of port B of the electrically controlled load sensitive valve (11) can be controlled to control the rope retraction force of the winch (5). Ports A and B of the travel pump (13) are connected to ports A and B of the travel motor (15), respectively.
2. The winch automatic synchronous hydraulic system according to claim 1, wherein, The A port of the variable piston motor (8) is connected to the T3 port of the electrically controlled load sensitive valve (11) through the oil replenishment check valve (9). The flow direction of the oil replenishment check valve (9) is from the T3 port of the electrically controlled load sensitive valve (11) to the A port of the variable piston motor (8).
3. The winch automatic synchronous hydraulic system according to claim 1 or 2, wherein, It also includes a shuttle valve (3), the X port of the variable piston pump (1) is connected to the 3 port of the shuttle valve (3), the 1 port of the shuttle valve (3) is connected to the LS port of the external working load sensitive valve, and the 2 port of the shuttle valve (3) is connected to the LS port of the electrically controlled load sensitive valve (11).
4. The winch automatic synchronization hydraulic system according to any one of claims 1 to 3, wherein, The pressure reducing valve (2) has its 2nd port connected to the oil inlet of the external working oil circuit to provide hydraulic oil to the external working oil circuit; the pressure reducing valve (2) has its 3rd port connected to the oil tank.
5. The winch automatic synchronization hydraulic system according to any one of claims 1 to 4, wherein, It also includes an electromagnetic reversing valve (4), the P port of which is connected to the F port of the travel pump (13), and the A port of which is connected to the brake oil port of the winch (5).
6. The winch automatic synchronization hydraulic system according to claim 5, wherein, The electromagnetic directional valve (4) has a left position and a right position. When the electromagnetic directional valve (4) is not energized, it is in the left position. The A port of the electromagnetic directional valve (4) is connected to the T port, and the winch (5) is braked. When the electromagnetic directional valve (4) is energized, it is in the right position. The P port and A port of the electromagnetic directional valve (4) are connected. The A port of the electromagnetic directional valve (4) outputs hydraulic oil to the brake oil port of the winch (5) so that the winch (5) is released from the brake.
7. The winch automatic synchronization hydraulic system according to any one of claims 1 to 6, wherein, It also includes a tension sensor (7), an encoder (6), a speed sensor (14), and a controller. The tension sensor (7) is used to detect the tension value of the wire rope. The encoder (6) is used to calculate the speed of winding or releasing the wire rope in conjunction with a timer. The speed sensor (14) is installed on the walking motor (15) to detect the motor speed and calculate the walking speed. The controller is configured to control the speed of the walking motor (15), the opening degree of the electronically controlled load sensitive valve (11), the flow rate of the variable piston pump (1), the set pressure of the first electro-proportional relief valve (10), and / or the set pressure of the second electro-proportional relief valve (12) according to the tension value of the wire rope.
8. A control method for an automatic synchronous hydraulic system for a winch, wherein, The winch automatic synchronization hydraulic system according to any one of claims 1-7 is used for this purpose, and the control method includes: When the vehicle is not started, the winch (5) is in the braking state, the variable piston motor (8) is at its maximum displacement, the A port and B port of the electronically controlled load sensitive valve (11) do not output hydraulic oil, the travel pump (13) is at zero displacement, and the travel motor (15) is at its maximum displacement. After the vehicle is powered on and started, in response to the direction switch and throttle signal, the winch (5) brake is released, the travel motor (15) is started to drive the vehicle to travel and the vehicle's travel speed, the tension value of the wire rope and the speed at which the winch (5) takes in or releases the wire rope are obtained in real time. Based on the tension value of the wire rope, determine the synchronization relationship between the vehicle's movement and the winch (5); based on the synchronization relationship between the vehicle's movement and the winch (5), adjust the vehicle's speed and the speed at which the winch (5) pulls in or releases the wire rope so that the tension value of the wire rope is maintained within a safe range. If the difference between the vehicle's travel speed and the speed at which the winch (5) pulls in or releases the wire rope exceeds a preset range, the winch (5) will be braked, and the vehicle will stop moving.
9. The control method for the automatic synchronous hydraulic system of the winch according to claim 8, wherein, The method of adjusting the vehicle's travel speed and the speed at which the winch (5) pulls in or releases the wire rope based on the synchronization relationship between the vehicle's travel and the winch (5) includes: If the difference between the tension value of the wire rope and the lower limit of the safety range is lower than the danger threshold, the synchronization relationship between the vehicle travel and the winch (5) is determined to be that the speed at which the winch (5) takes in or releases the wire rope is faster than the travel speed. At this time, the speed at which the winch (5) takes in or releases the wire rope is reduced. If the difference between the tension value of the wire rope and the upper limit of the safe range is lower than the danger threshold, the synchronization relationship between the vehicle travel and the winch (5) is determined to be that the speed at which the winch (5) pulls up or releases the wire rope is slower than the travel speed. At this time, the travel speed is reduced. If the pulling force of the winch (5) exceeds the safe range, brake the winch (5) and stop the vehicle from moving.
10. The control method for the winch automatic synchronous hydraulic system according to claim 8 or 9, wherein, The walking speed is adjusted by controlling the current through a proportional valve of the walking motor (15); The speed at which the winch (5) winds up or releases the wire rope is achieved by adjusting the opening of the electrically controlled load-sensitive valve (11) or the flow rate of the variable piston pump (1); If the winch (5) is in the rope-releasing state, the set pressure of the first electro-proportional relief valve (10) is adjusted to control the back pressure of port B of the variable piston motor (8) so as to adjust the rope-releasing tension of the winch (5). The adjustment of the set pressure of the first electro-proportional relief valve (10) is achieved by adjusting the control current of the first electro-proportional relief valve (10). If the winch (5) is in the rope-reeling state, the set pressure of the second electro-proportional relief valve (12) is adjusted to control the pressure of port B of the electrically controlled load sensitive valve (11) in order to adjust the rope-reeling tension of the winch (5). The adjustment of the set pressure of the second electro-proportional relief valve (12) is achieved by adjusting the control current of the second electro-proportional relief valve (12).