Unloading system

Abstract

The utility model provides an unloading system which comprises a hydraulic pump station and a winch control system, the hydraulic pump station supplies oil to the winch control system, the winch control system drives a motor and a second motor to rotate, the winch control system comprises a first oil way and a second oil way, the first oil way drives the motor to rotate, and the second oil way drives the second motor to rotate. The second oil way drives the second motor to rotate; the first oil way comprises a first middle-position unloading valve and a first operating valve, the second oil way comprises a second middle-position unloading valve and a second operating valve, and a first unloading shuttle valve is arranged between the first oil way and the second oil way; according to the structure, when one winch needs to be started, unloading oil ways of the two winches are closed, and full-load operation of the winches can be conducted.

Description

Technical Field

[0001] The utility model relates to the technical field of winch control, in particular to a unloading system. Background Technique

[0002] Generally, multiple winches are installed on a ship. Each winch shares a hydraulic pump module, and each winch is equipped with a control module and a hydraulic motor module respectively. Since the loads of each winch are different, the flow rates required to be output by each hydraulic motor module are also different. In order to ensure the normal operation of the winch with the largest load, the constant pressure variable pump in the hydraulic pump module will always work under high pressure. Therefore, a large amount of energy consumption loss is easily caused.

[0003] For example, in the patent document with the Chinese patent application number 201811457352.4 and the publication date of February 12, 2019, an electro-hydraulic proportional multi-hydraulic winch control system and its control strategy are disclosed. The system includes three hydraulic winches and their control systems. This document can further reduce the energy consumption of centralized pumping station type multi-winch hydraulic control and further realize the high-precision cooperative operation of multiple winches.

[0004] However, this document does not consider how to realize the low-pressure circulation of hydraulic oil when the winch is on standby under the condition that the fixed displacement pump always needs to supply oil under high pressure, which easily leads to an increase in the energy consumption of the winch, and when one winch is working and the other winch is on standby, it can only be simply controlled and cannot well ensure the stability of the oil supply of the working winch. Summary of the Invention

[0005] The utility model provides a unloading system, which can drive two winches and can carry out low-pressure circulation of the hydraulic oil circuit when the winches are on standby, thereby reducing the energy consumption of the hydraulic system. At the same time, when one winch needs to be started, the unloading oil circuits of the two winches are closed, so that the full-load operation of the winches can be carried out, and thus the stability of the oil supply of the working winch can be well ensured.

[0006] To achieve the above object, the technical solution of the utility model is: a unloading system, including a hydraulic pump station and a winch control system. The hydraulic pump station supplies oil to the winch control system, and the winch control system drives a first motor and a second motor to rotate. The winch control system includes a first oil circuit and a second oil circuit. The first oil circuit drives the first motor to rotate, and the second oil circuit drives the second motor to rotate.

[0007] The first oil circuit includes a first center unloading valve and a first control valve. The oil outlet of the hydraulic pump station is connected to the P port of the first control valve through a first oil supply pipeline. The T port of the first control valve is connected to the oil return port of the hydraulic pump station through a first oil return pipeline. The A port of the first control valve is connected to the first port of the motor, and the B port of the first control valve is connected to the second port of the motor. A first center unloading valve is provided between the first oil supply pipeline and the first oil return pipeline. The oil inlet end of the first center unloading valve is connected to the first oil supply pipeline, the oil outlet end of the first center unloading valve is connected to the first oil return pipeline, and the first control end of the first center unloading valve is connected to the first oil supply pipeline. The P1 port and the T1 port of the first control valve are connected to the second control end of the first center unloading valve. When the first control valve is commutated, the P1 port is communicated with the P port and the T port is communicated with the T1 port, or the P1 port is communicated with the T port and the P port is communicated with the T1 port.

[0008] The second oil circuit includes a second center unloading valve and a second control valve. The oil outlet of the hydraulic pump station is connected to the P port of the second control valve through a second oil supply pipeline. The T port of the second control valve is connected to the oil return port of the hydraulic pump station through a second oil return pipeline. The A port of the second control valve is connected to the first port of the second motor, and the B port of the second control valve is connected to the second port of the second motor. A second center unloading valve is provided between the second oil supply pipeline and the second oil return pipeline. The oil inlet end of the second center unloading valve is connected to the second oil supply pipeline, the oil outlet end of the second center unloading valve is connected to the second oil return pipeline, and the first control end of the second center unloading valve is connected to the second oil supply pipeline. The P1 port and the T1 port of the second control valve are connected to the second control end of the second center unloading valve. When the second control valve is commutated, the P1 port is communicated with the P port and the T port is communicated with the T1 port, or the P1 port is communicated with the T port and the P port is communicated with the T1 port.

[0009] A first unloading shuttle valve is provided between the first oil circuit and the second oil circuit. The first port of the first unloading shuttle valve is connected to the P1 port and the T1 port of the first control valve. The second port of the first unloading shuttle valve is connected to the P1 port and the T1 port of the second control valve. The third port of the first unloading shuttle valve is connected to the second control end of the first center unloading valve and the second control end of the second center unloading valve.

[0010] In the above structure, the hydraulic pump station supplies oil to the first motor and the second motor. When starting the winch, to drive the first motor to rotate, the first control valve is commutated. Thus, when the P port of the first control valve is connected to the A port and the B port is connected to the T port, the first motor rotates forward; or when the P port of the first control valve is connected to the B port and the A port is connected to the T port, the first motor rotates backward. In this way, the control of the first motor is realized. Since the first center unloading valve is arranged between the first oil inlet pipeline and the first oil return pipeline, when the hydraulic pump station supplies oil, if the first control valve is not commutated, the hydraulic oil in the first oil inlet pipeline flows into the first control end of the first center unloading valve at this time, so that the first center unloading valve is connected, and the hydraulic oil can be unloaded through the first center unloading valve and flow back to the hydraulic pump station; when the first control valve is commutated, the P1 port is connected to the P port and the T port is connected to the T1 port, or the P1 port is connected to the T port and the P port is connected to the T1 port. Thus, the hydraulic oil flowing from the hydraulic pump station to the P port of the first control valve can flow through the P1 port and the T1 port to the second control end of the first center unloading valve. At this time, the hydraulic oil drives the first center unloading valve to disconnect, so that the hydraulic oil cannot be unloaded through the first center unloading valve, and the hydraulic oil can be supplied normally and drive the first motor to rotate. Therefore, through the setting of the first center unloading valve, when the winch is on standby, the first center unloading valve opens, and the hydraulic oil is unloaded through the first center unloading valve and flows back to the hydraulic pump station to realize low-pressure circulation, so as to ensure that the energy consumption of the winch will not be too large. When the first motor needs to work, the first center unloading valve is controlled to disconnect by the hydraulic oil flowing to the first control valve, so that the hydraulic oil can flow to the first motor normally for operation.

[0011] To drive the second motor to rotate, the second control valve is commutated, so that the P port of the second control valve is connected to the A port and the B port is connected to the T port to control the forward rotation of the second motor, or the P port of the first control valve is connected to the B port and the A port is connected to the T port to control the reverse rotation of the second motor, thereby realizing the control of the second motor. Since a second neutral unloading valve is provided between the second oil inlet pipeline and the second oil return pipeline, when the hydraulic pump station supplies oil, if the second control valve is not commutated, at this time, the hydraulic oil in the second oil inlet pipeline flows into the first control end of the second neutral unloading valve, so that the second neutral unloading valve is connected, and the hydraulic oil can be unloaded through the second neutral unloading valve and flow back to the hydraulic pump station; when the second control valve is commutated, the P1 port is connected to the P port and the T port is connected to the T1 port, or the P1 port is connected to the T port and the P port is connected to the T1 port, so that the hydraulic oil flowing from the hydraulic pump station to the P port of the second control valve can flow through the P1 port and the T1 port to the second control end of the second neutral unloading valve. At this time, the hydraulic oil drives the second neutral unloading valve to disconnect, so that the hydraulic oil cannot be unloaded through the second neutral unloading valve, and the hydraulic oil can supply oil normally and drive the second motor to rotate. Therefore, through the setting of the second neutral unloading valve, when the winch is on standby, the second neutral unloading valve opens, and the hydraulic oil is unloaded through the second neutral unloading valve and flows back to the hydraulic pump station to realize low-pressure circulation, so as to ensure that the energy consumption of the winch will not be too large. When the second motor needs to work, the second neutral unloading valve is controlled to disconnect by the hydraulic oil flowing to the second control valve, so that the hydraulic oil can flow to the second motor normally for operation.

[0012] Meanwhile, by providing a first unloading shuttle valve between the first oil circuit and the second oil circuit, when one motor needs to work and the other motor is on standby, the hydraulic oil flows through the first control valve or the second control valve to the first unloading shuttle valve, so that the first port of the first unloading shuttle valve is connected to the third port or the second port is connected to the third port. Thus, the hydraulic oil can flow through the third port of the first unloading shuttle valve to the second control end of the first neutral unloading valve and the second control end of the second neutral unloading valve, thereby closing the neutral unloading valve to prevent the hydraulic oil from being unloaded by the neutral unloading valve during the operation of the winch, resulting in insufficient oil pressure.

[0013] Furthermore, a spring is also provided at the second control end of the first neutral unloading valve, and the spring pushes the internal oil circuit of the first neutral unloading valve to disconnect the oil inlet end and the oil outlet end of the first neutral unloading valve.

[0014] A second spring is also provided at the second control end of the second neutral unloading valve, and the second spring pushes the internal oil circuit of the second neutral unloading valve to disconnect the oil inlet end and the oil outlet end of the second neutral unloading valve.

[0015] With the above settings, the pressure of the hydraulic oil in the spring plus the second control end is used to overcome the pressure of the hydraulic oil flowing into the first control end of the neutral unloading valve, so as to ensure that the oil inlet end and the oil outlet end of the neutral unloading valve are disconnected, and prevent the hydraulic oil from flowing back to the fuel tank from the neutral unloading valve during normal operation of the oil circuit. Further, a first shuttle valve is provided between the P1 end and the T1 end of the first control valve and the second control end of the first neutral unloading valve. The first port of the first shuttle valve is connected to the P1 end of the first control valve, the second port of the first shuttle valve is connected to the T1 end of the first control valve, and the third port of the first shuttle valve is connected to the second control end of the first neutral unloading valve.

[0016] A second shuttle valve is provided between the P1 end and the T1 end of the second control valve and the second control end of the second neutral unloading valve. The first port of the second shuttle valve is connected to the P1 end of the second control valve, the second port of the second shuttle valve is connected to the T1 end of the second control valve, and the third port of the second shuttle valve is connected to the second control end of the second neutral unloading valve.

[0017] With the above settings, by setting the first shuttle valve and the second shuttle valve, the problem that the hydraulic oil flowing into the second control end of the neutral unloading valve from the P1 end and the T1 end of the first control valve and the second control valve conflicts with each other is prevented.

[0018] Further, a third shuttle valve is provided between the second control end of the first neutral unloading valve and the third port of the first unloading shuttle valve. The first port of the third shuttle valve is connected to the third port of the first shuttle valve, the second port of the third shuttle valve is connected to the third port of the first unloading shuttle valve, and the third port of the third shuttle valve is connected to the second control end of the first neutral unloading valve;

[0019] A fourth shuttle valve is provided between the second control end of the second neutral unloading valve and the third port of the first unloading shuttle valve. The first port of the fourth shuttle valve is connected to the third port of the second shuttle valve, the second port of the fourth shuttle valve is connected to the third port of the first unloading shuttle valve, and the third port of the fourth shuttle valve is connected to the second control end of the second neutral unloading valve.

[0020] With the above settings, by setting the third shuttle valve and the fourth shuttle valve, the problem that the hydraulic oil between the second control terminal flowing into the neutral unloading valve and other oil circuits conflicts with each other is prevented.

[0021] Further, a first overflow valve is provided between the second control end of the first neutral unloading valve and the first oil return pipe. The oil inlet end of the first overflow valve is connected to the second control end of the first neutral unloading valve, and the oil outlet end of the first overflow valve is connected to the first oil return pipe.

[0022] With the above settings, by setting the first overflow valve, when the winch is on standby, the first overflow valve is de-energized and normally open, so that the hydraulic oil is unloaded and the pressure is reduced through the first overflow valve to achieve low-pressure circulation of the hydraulic oil, thus playing an energy-saving role. When the winch is working, the first overflow valve is energized and closed, so that the hydraulic oil is pressurized and enters the motor for work.

[0023] Further, a first pressure reducing valve is also provided on the first oil inlet pipeline. The oil inlet end of the first pressure reducing valve is connected to the oil outlet of the hydraulic pump station through the first oil inlet pipeline, and the oil outlet end of the first pressure reducing valve is connected to the P end of the first control valve through the first oil inlet pipeline.

[0024] With the above settings, through the setting of the first pressure reducing valve, the oil pressure of the oil circuit can be set, which is convenient for controlling the winch.

[0025] Further, the hydraulic pump station includes an oil tank, a first oil pump and a second oil pump. The oil inlet ends of the first oil pump and the second oil pump are connected to the oil tank. The oil outlet ends of the first oil pump and the second oil pump are connected to the first oil inlet pipeline and the second oil inlet pipeline through the oil outlet. The first oil return pipeline and the second oil return pipeline are connected to the oil tank through the oil return port.

[0026] With the above settings, by setting two oil pumps, the winch can achieve full-load operation. And if one of the oil pumps fails and cannot work, the winch can still be driven to operate at half load by the other oil pump, preventing the winch from suddenly stopping and causing accidents.

[0027] A second unloading shuttle valve is provided between the first control valve and the first unloading shuttle valve. The first port of the second unloading shuttle valve is connected to the P1 end of the first control valve, the second port of the second unloading shuttle valve is connected to the T1 end of the first control valve, and the third port of the second unloading shuttle valve is connected to the first port of the first unloading valve;

[0028] A third unloading shuttle valve is provided between the second control valve and the first unloading shuttle valve. The first port of the third unloading shuttle valve is connected to the P1 end of the second control valve, the second port of the third unloading shuttle valve is connected to the T1 end of the second control valve, and the third port of the third unloading shuttle valve is connected to the second port of the first unloading valve.

[0029] With the above settings, by setting the second unloading shuttle valve and the third unloading shuttle valve, the problem that the hydraulic oil flowing into the first unloading shuttle valve from the P1 end and the T1 end of the first control valve and the second control valve conflicts with each other is prevented. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a hydraulic schematic diagram of the control system of the present invention.

[0031] Figure 2 It is a connection schematic diagram of the first oil circuit and the hydraulic pump station of the present invention.

[0032] Figure 3 It is a schematic diagram of the first oil circuit of the present utility model.

[0033] Figure 4 It is a schematic diagram of the connection between the first oil circuit of the present utility model and the first unloading shuttle valve.

[0034] Figure 5 It is a schematic diagram of the second oil circuit of the present utility model. Detailed implementation manners

[0035] The present utility model will be further described in detail below with reference to the accompanying drawings and specific implementation manners.

[0036] As Figures 1 to 5 shown, a unloading system includes a hydraulic pump station 1 and a winch control system. The hydraulic pump station 1 supplies oil to the winch control system. The winch control system drives a motor 3 and a second motor 4 to rotate. The winch control system includes a first oil circuit 201 and a second oil circuit 202. The first oil circuit 201 drives the motor 3 to rotate, and the second oil circuit 202 drives the second motor 4 to rotate.

[0037] The first oil circuit 201 includes a first center unloading valve 21 and a first control valve 22. The oil outlet 11 of the hydraulic pump station 1 is connected to the P end of the first control valve 22 through a first oil supply pipeline 12. The T end of the first control valve 22 is connected to the oil return port 14 of the hydraulic pump station 1 through a first oil return pipeline 13. The A end of the first control valve 22 is connected to the first port A1 of the motor 3, and the B end of the first control valve 22 is connected to the second port B1 of the motor 3.

[0038] As Figure 2 shown, a first center unloading valve 21 is provided between the first oil supply pipeline 12 and the first oil return pipeline 13. The oil inlet end of the first center unloading valve 21 is connected to the first oil supply pipeline 12, the oil outlet end of the first center unloading valve 21 is connected to the first oil return pipeline 13, and the first control end 211 of the first center unloading valve 21 is connected to the first oil supply pipeline 12. The P1 end and the T1 end of the first control valve 22 are connected to the second control end 212 of the first center unloading valve 21. When the first control valve 22 is commutated, the P1 end is communicated with the P end and the T end is communicated with the T1 end, or the P1 end is communicated with the T end and the P end is communicated with the T1 end.

[0039] As Figure 1 and Figure 5As shown, the second oil circuit 202 includes a second neutral unloading valve 51 and a second control valve 52. The oil outlet 11 of the hydraulic pump station 1 is connected to the P port of the second control valve 52 through a second oil supply pipeline 101. The T port of the second control valve 52 is connected to the oil return port 14 of the hydraulic pump station through a second oil return pipeline 102. The A port of the second control valve 52 is connected to the first port 41 of the second motor 4, and the B port of the second control valve is connected to the second port 41 of the second motor.

[0040] A second neutral unloading valve 51 is provided between the second oil supply pipeline 101 and the second oil return pipeline 102. The oil inlet end of the second neutral unloading valve 51 is connected to the second oil supply pipeline 101, the oil outlet end of the second neutral unloading valve 51 is connected to the second oil return pipeline 102, and the first control end 511 of the second neutral unloading valve 51 is connected to the second oil supply pipeline 101. The P1 port and the T1 port of the second control valve 52 are connected to the second control end 512 of the second neutral unloading valve 51. When the second control valve 52 is shifted, the P1 port communicates with the P port and the T port communicates with the T1 port, or the P1 port communicates with the T port and the P port communicates with the T1 port.

[0041] As Figure 1 、 Figure 4 and Figure 5 shown, a first unloading shuttle valve 6 is provided between the first oil circuit 201 and the second oil circuit 202. The first port 61 of the first unloading shuttle valve 6 is connected to the P1 port and the T1 port of the first control valve 22. The second port 62 of the first unloading shuttle valve 6 is connected to the P1 port and the T1 port of the second control valve 52. The third port 63 of the first unloading shuttle valve 6 is connected to the second control end 211 of the first neutral unloading valve 21 and the second control end 511 of the second neutral unloading valve 51.

[0042] A spring 213 is further provided on the second control end 212 of the first neutral unloading valve 21. The spring 213 pushes the internal oil circuit of the first neutral unloading valve 21 to disconnect the oil inlet end and the oil outlet end of the first neutral unloading valve 21.

[0043] A second spring 513 is further provided on the second control end 512 of the second neutral unloading valve 51. The second spring 513 pushes the internal oil circuit of the second neutral unloading valve 51 to disconnect the oil inlet end and the oil outlet end of the second neutral unloading valve 51.

[0044] The pressure of the hydraulic oil flowing into the first control end 211 of the first neutral unloading valve 21 is overcome by the spring 213 plus the hydraulic oil pressure at the second control end 212, so as to ensure that the oil inlet end and the oil outlet end of the first neutral unloading valve 21 are disconnected, and prevent the hydraulic oil from flowing back to the fuel tank from the first neutral unloading valve 21 during the normal operation of the oil circuit.

[0045] As Figure 3 and Figure 4As shown, a first shuttle valve 23 is provided between the P1 port and the T1 port of the first control valve 22 and the second control end 212 of the first neutral unloading valve 21. The first port 231 of the first shuttle valve 23 is connected to the P1 port of the first control valve 22, the second port 232 of the first shuttle valve 23 is connected to the T1 port of the first control valve 22, and the third port 233 of the first shuttle valve 23 is connected to the second control end 212 of the first neutral unloading valve 21.

[0046] By providing the first shuttle valve 23, it is possible to prevent the hydraulic oil flowing from the P1 port and the T1 port of the first control valve 22 into the second control end 212 of the first neutral unloading valve 21 from conflicting with each other.

[0047] As Figure 5 shown, a second shuttle valve 53 is provided between the P1 port and the T1 port of the second control valve 52 and the second control end 512 of the second neutral unloading valve 51. The first port 531 of the second shuttle valve 53 is connected to the P1 port of the second control valve 52, the second port 532 of the second shuttle valve 53 is connected to the T1 port of the second control valve 52, and the third port 533 of the second shuttle valve 53 is connected to the second control end of the second neutral unloading valve 51. In this embodiment, the working principle of the second shuttle valve 53 is the same as that of the first shuttle valve 23.

[0048] As Figure 4 shown, a third shuttle valve 26 is provided between the second control end 212 of the first neutral unloading valve 21 and the third port 63 of the first unloading shuttle valve 6. The first port 261 of the third shuttle valve 26 is connected to the third port 233 of the first shuttle valve 23, the second port 262 of the third shuttle valve 26 is connected to the third port 63 of the first unloading shuttle valve 6, and the third port 263 of the third shuttle valve 26 is connected to the second control end 212 of the first neutral unloading valve 21;

[0049] A fourth shuttle valve 66 is provided between the second control end 512 of the second neutral unloading valve 51 and the third port 63 of the first unloading shuttle valve 6. The first port 661 of the fourth shuttle valve 66 is connected to the third port 533 of the second shuttle valve 53, the second port 662 of the fourth shuttle valve 66 is connected to the third port 63 of the first unloading shuttle valve 6, and the third port 663 of the fourth shuttle valve 66 is connected to the second control end 512 of the second neutral unloading valve 51.

[0050] With the above settings, by providing the third shuttle valve 26 and the fourth shuttle valve 66, it is possible to prevent the problem of hydraulic oil conflict between the second control terminal of the neutral unloading valve and other oil circuits.

[0051] A first overflow valve 24 is provided between the second control end 212 of the first neutral unloading valve 21 and the first oil return pipeline 13. The oil inlet end of the first overflow valve 24 is connected to the second control end 212 of the first neutral unloading valve 21, and the oil outlet end of the first overflow valve 24 is connected to the first oil return pipeline 13. By providing the first overflow valve 24, when the winch is on standby, the first overflow valve 24 is normally open when de-energized, so that the hydraulic oil is unloaded and the pressure is reduced through the first overflow valve 24 to achieve the low-pressure circulation of the hydraulic oil, thereby playing an energy-saving role. When the winch is working, the first overflow valve 24 is energized and closed, so that the hydraulic oil is pressurized and enters the motor for work. In this embodiment, a second overflow valve 64 is provided between the second control end 512 of the second neutral unloading valve 51 and the second oil return pipeline 102. The second overflow valve 64 has the same structure and working principle as the first overflow valve 24.

[0052] A first pressure reducing valve 25 is also provided on the first oil inlet pipeline 12. The oil inlet end of the first pressure reducing valve 25 is connected to the oil outlet of the hydraulic pump station through the first oil inlet pipeline 12, and the oil outlet end of the first pressure reducing valve 25 is connected to the P end of the first control valve 22 through the first oil inlet pipeline 12. Through the setting of the first pressure reducing valve 25, the oil pressure of the oil circuit can be set, which is convenient for the control of the winch. In this embodiment, a second pressure reducing valve 65 is also provided on the second oil inlet pipeline 101. The second pressure reducing valve 65 has the same structure and working principle as the first pressure reducing valve 25.

[0053] As Figure 1 shown, the hydraulic pump station 1 includes an oil tank 15, a first oil pump 16 and a second oil pump 17. The oil inlet ends of the first oil pump 116 and the second oil pump 17 are connected to the oil tank 15. The oil outlet ends of the first oil pump 16 and the second oil pump 17 are connected to the first oil inlet pipeline 12 and the second oil inlet pipeline 101 through the oil outlet 11. The first oil return pipeline 13 and the second oil return pipeline 102 are connected to the oil tank 15 through the oil return port 14; the first oil pump 16 and the second oil pump 17 are fixed-displacement pumps. By providing fixed-displacement pumps, it is ensured that the winch can work under the state of maximum load. By providing two oil pumps, the winch can achieve full-load operation. And if one of the oil pumps fails and cannot work, the winch can still be driven to operate at half load by the other oil pump, preventing the winch from suddenly stopping and causing accidents.

[0054] As Figure 4 shown, a second unloading shuttle valve 7 is provided between the first control valve 22 and the first unloading shuttle valve 6. The first port 71 of the second unloading shuttle valve 7 is connected to the P1 end of the first control valve 22, the second port 72 of the second unloading shuttle valve 7 is connected to the T1 end of the first control valve 22, and the third port 73 of the second unloading shuttle valve 7 is connected to the first port 71 of the first unloading valve 6;

[0055] As Figure 5As shown in the figure, a third unloading shuttle valve 8 is provided between the second control valve 52 and the first unloading shuttle valve 6. The first port 81 of the third unloading shuttle valve 8 is connected to the P1 end of the second control valve 52, the second port 82 of the third unloading shuttle valve 8 is connected to the T1 end of the second control valve 82, and the third port 83 of the third unloading shuttle valve 8 is connected to the second port 62 of the first unloading valve.

[0056] With the above settings, by providing the second unloading shuttle valve 7 and the third unloading shuttle valve 8, the problem of the hydraulic oil flowing into the first unloading shuttle valve 6 from the P1 end and the T1 end of the first control valve 22 and the second control valve 52 conflicting with each other is prevented.

[0057] The working principle of the present utility model:

[0058] The hydraulic pump station supplies oil to the motor and the second motor. When starting the winch, to drive the motor to rotate, the first control valve is controlled to change its direction. Thus, when the P end of the first control valve is connected to the A end and the B end is connected to the T end, the motor rotates forward, or when the P end of the first control valve is connected to the B end and the A end is connected to the T end, the motor rotates in reverse, thereby realizing the control of the motor. Since the first neutral unloading valve is provided between the first oil inlet pipeline and the first oil return pipeline, when the hydraulic pump station supplies oil, if the first control valve does not change its direction, at this time, the hydraulic oil in the first oil inlet pipeline flows into the first control end of the first neutral unloading valve, so that the first neutral unloading valve is connected, and the hydraulic oil can be unloaded through the first neutral unloading valve and flow back to the hydraulic pump station; when the first control valve changes its direction, the P1 end is connected to the P end and the T end is connected to the T1 end, or the P1 end is connected to the T end and the P end is connected to the T1 end. Thus, the hydraulic oil flowing from the hydraulic pump station to the P end of the first control valve can flow through the P1 end and the T1 end to the second control end of the first neutral unloading valve. At this time, the hydraulic oil drives the first neutral unloading valve to disconnect, so that the hydraulic oil cannot be unloaded through the first neutral unloading valve, and the hydraulic oil can supply oil normally and drive the motor to rotate. Therefore, through the setting of the first neutral unloading valve, when the winch is on standby, the first neutral unloading valve opens, and the hydraulic oil is unloaded through the first neutral unloading valve and flows back to the hydraulic pump station to realize low-pressure circulation, so as to ensure that the energy consumption of the winch will not be too large. When the motor needs to work, the first neutral unloading valve is controlled to disconnect by the hydraulic oil flowing to the first control valve, so that the hydraulic oil can flow to the motor normally for operation.

[0059] To drive the second motor to rotate, the second control valve is commutated, so that the P port of the second control valve communicates with the A port and the B port communicates with the T port to control the forward rotation of the second motor, or the P port of the first control valve communicates with the B port and the A port communicates with the T port to control the reverse rotation of the second motor, thereby realizing the control of the second motor. Since a second neutral unloading valve is provided between the second oil inlet pipeline and the second oil return pipeline, when the hydraulic pump station supplies oil, if the second control valve is not commutated, at this time, the hydraulic oil in the second oil inlet pipeline flows into the first control end of the second neutral unloading valve, so that the second neutral unloading valve is communicated, and the hydraulic oil can be unloaded through the second neutral unloading valve and flow back to the hydraulic pump station; when the second control valve is commutated, the P1 port communicates with the P port and the T port communicates with the T1 port or the P1 port communicates with the T port and the P port communicates with the T1 port, so that the hydraulic oil flowing from the hydraulic pump station to the P port of the second control valve can flow through the P1 port and the T1 port to the second control end of the second neutral unloading valve. At this time, the hydraulic oil drives the second neutral unloading valve to disconnect, so that the hydraulic oil cannot be unloaded through the second neutral unloading valve, and the hydraulic oil can be supplied normally and drive the second motor to rotate. Thus, through the setting of the second neutral unloading valve, when the winch is on standby, the second neutral unloading valve is opened so that the hydraulic oil is unloaded through the second neutral unloading valve and flows back to the hydraulic pump station to realize low-pressure circulation, thereby ensuring that the energy consumption of the winch will not be too large. When the second motor needs to work, the second neutral unloading valve is controlled to disconnect by the hydraulic oil flowing to the second control valve, so that the hydraulic oil can flow to the second motor normally for operation.

[0060] Meanwhile, by providing a first unloading shuttle valve between the first oil circuit and the second oil circuit, when one motor needs to work and the other motor is on standby, the hydraulic oil flows through the first control valve or the second control valve to the first unloading shuttle valve, so that the first port of the first unloading shuttle valve communicates with the third port or the second port communicates with the third port. Thus, the hydraulic oil can flow through the third port of the first unloading shuttle valve to the second control end of the first neutral unloading valve and the second control end of the second neutral unloading valve, thereby closing the neutral unloading valve to prevent the hydraulic oil from being unloaded by the neutral unloading valve and causing insufficient oil pressure when the winch is working.

Claims

1. A load unloading system, comprising a hydraulic pump station and a winch control system, wherein the hydraulic pump station supplies oil to the winch control system, and the winch control system drives a motor and a second motor to rotate, characterized in that: The winch control system comprises a first oil circuit and a second oil circuit, the first oil circuit drives the motor to rotate, and the second oil circuit drives the second motor to rotate; The first oil circuit includes a first mid-position unloading valve and a first control valve, the oil outlet of the hydraulic pump station is connected to the P end of the first control valve through a first oil outlet pipeline, the T end of the first control valve is connected to the oil return port of the hydraulic pump station through a first oil return pipeline, the A end of the first control valve is connected to the first port of the motor, and the B end of the first control valve is connected to the second port of the motor; A first mid-position unloading valve is provided between the first oil inlet pipeline and the first oil return pipeline, the oil inlet end of the first mid-position unloading valve is connected to the first oil inlet pipeline, the oil outlet end of the first mid-position unloading valve is connected to the first oil return pipeline, and the first control end of the first mid-position unloading valve is connected to the first oil inlet pipeline; the P1 end and the T1 end of the first control valve are connected to the second control end of the first mid-position unloading valve, and when the first control valve is switched, the P1 end is connected to the P end and the T end is connected to the T1 end, or the P1 end is connected to the T end and the P end is connected to the T1 end; The second oil circuit includes a second mid-position unloading valve and a second control valve, the oil outlet of the hydraulic pump station is connected to the P end of the second control valve through a second oil outlet pipeline, the T end of the second control valve is connected to the oil return port of the hydraulic pump station through a second oil return pipeline, the A end of the second control valve is connected to the first port of the second motor, and the B end of the second control valve is connected to the second port of the second motor; A second mid-position unloading valve is provided between the second oil inlet pipeline and the second oil return pipeline, the oil inlet end of the second mid-position unloading valve is connected to the second oil inlet pipeline, the oil outlet end of the second mid-position unloading valve is connected to the second oil return pipeline, and the first control end of the second mid-position unloading valve is connected to the second oil inlet pipeline; the P1 end and the T1 end of the second control valve are connected to the second control end of the second mid-position unloading valve, and when the second control valve is switched, the P1 end is connected to the P end and the T end is connected to the T1 end, or the P1 end is connected to the T end and the P end is connected to the T1 end; A first unloading shuttle valve is provided between the first oil circuit and the second oil circuit, wherein a first port of the first unloading shuttle valve is connected to the P1 end and the T1 end of the first control valve, a second port of the first unloading shuttle valve is connected to the P1 end and the T1 end of the second control valve, and a third port of the first unloading shuttle valve is connected to the second control end of the first mid-position unloading valve and the second control end of the second mid-position unloading valve.

2. A load unloading system according to claim 1, characterized in that: A spring is also provided on the second control end of the first mid-position unloading valve, and the spring pushes the internal oil circuit of the first mid-position unloading valve so that the oil inlet end and the oil outlet end of the first mid-position unloading valve are disconnected; A second spring is also provided on the second control end of the second mid-position unloading valve. The second spring pushes the internal oil circuit of the second mid-position unloading valve so that the oil inlet end and the oil outlet end of the second mid-position unloading valve are disconnected.

3. The unloading system according to claim 1, characterized in that: A first shuttle valve is provided between the P1 end and the T1 end of the first control valve and the second control end of the first mid-position unloading valve, wherein the first port of the first shuttle valve is connected to the P1 end of the first control valve, the second port of the first shuttle valve is connected to the T1 end of the first control valve, and the third port of the first shuttle valve is connected to the second control end of the first mid-position unloading valve; A second shuttle valve is provided between the P1 end and the T1 end of the second control valve and the second control end of the second mid-position unloading valve, wherein the first port of the second shuttle valve is connected to the P1 end of the second control valve, the second port of the second shuttle valve is connected to the T1 end of the second control valve, and the third port of the second shuttle valve is connected to the second control end of the second mid-position unloading valve.

4. A load unloading system according to claim 3, characterized in that: A third shuttle valve is provided between the second control end of the first mid-position unloading valve and the third port of the first unloading shuttle valve, wherein the first port of the third shuttle valve is connected to the third port of the first shuttle valve, the second port of the third shuttle valve is connected to the third port of the first unloading shuttle valve, and the third port of the third shuttle valve is connected to the second control end of the first mid-position unloading valve; A fourth shuttle valve is provided between the second control end of the second mid-position unloading valve and the third port of the first unloading shuttle valve, the first port of the fourth shuttle valve is connected to the third port of the second shuttle valve, the second port of the fourth shuttle valve is connected to the third port of the first unloading shuttle valve, and the third port of the fourth shuttle valve is connected to the second control end of the second mid-position unloading valve.

5. The unloading system according to claim 1, characterized in that: A first overflow valve is provided between the second control end of the first mid-position unloading valve and the first oil return pipeline, the oil inlet end of the first overflow valve is connected to the second control end of the first mid-position unloading valve, and the oil outlet end of the first overflow valve is connected to the first oil return pipeline.

6. The unloading system according to claim 1, characterized in that: A first pressure reducing valve is also provided in the first oil inlet pipeline, the oil inlet end of the first pressure reducing valve is connected to the oil outlet of the hydraulic pump station through the first oil inlet pipeline, and the oil outlet end of the first pressure reducing valve is connected to the P end of the first control valve through the first oil inlet pipeline.

7. The unloading system according to claim 1, characterized in that: The hydraulic pump station includes an oil tank, a first oil pump and a second oil pump, wherein the oil inlet ends of the first oil pump and the second oil pump are connected to the oil tank, the oil outlet ends of the first oil pump and the second oil pump are connected to the first oil inlet pipeline and the second oil inlet pipeline through the oil outlet, and the first oil return pipeline and the second oil return pipeline are connected to the oil tank through the oil return port.

8. The unloading system according to claim 1, characterized in that: A second unloading shuttle valve is provided between the first control valve and the first unloading shuttle valve, wherein the first port of the second unloading shuttle valve is connected to the P1 end of the first control valve, the second port of the second unloading shuttle valve is connected to the T1 end of the first control valve, and the third port of the second unloading shuttle valve is connected to the first port of the first unloading valve; A third unloading shuttle valve is provided between the second control valve and the first unloading shuttle valve, wherein the first port of the third unloading shuttle valve is connected to the P1 end of the second control valve, the second port of the third unloading shuttle valve is connected to the T1 end of the second control valve, and the third port of the third unloading shuttle valve is connected to the second port of the first unloading valve.

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