Unloading hydraulic system

Abstract

The utility model provides an unloading hydraulic 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 to rotate, and the winch control system comprises a first middle-position unloading valve and a first operating valve. An oil outlet of the hydraulic pump station is connected with the P end of the first operating valve through a first oil outlet pipeline, the T end of the first operating valve is connected with an oil return opening of the hydraulic pump station through a first oil return pipeline, the A end of the first operating valve is connected with a first port of the motor, and the B end of the first operating valve is connected with a second port of the motor. A first middle-position unloading valve is arranged between the first oil inlet pipeline and the first oil return pipeline; by means of the structure, when the winch is standby, oil supplied by the hydraulic pump station can be unloaded and flow back to the oil tank, and therefore it is guaranteed that an oil way of the hydraulic system can circulate at low pressure, and energy consumption of the hydraulic system is small.

Description

Technical Field

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

[0002] A winch usually uses a hydraulic system to adjust the rotation speed and direction of the winch. A common hydraulic system usually includes a hydraulic pump module, a control module, and a hydraulic motor module. The hydraulic pump station mainly includes a constant pressure variable pump for providing hydraulic energy, and the hydraulic motor module mainly includes a winch motor for driving the winch. However, since the winch needs to lift different heavy objects, the load of the winch is also different, and the hydraulic oil flow required to be output by each winch motor is also different. In order to ensure that the winch can work properly when the load is the largest, therefore, the hydraulic pump needs to always work under high pressure, which is likely to cause a large amount of energy consumption loss.

[0003] For example, a patent document with a Chinese patent application number of 201710642677.9 and a publication date of January 16, 2018 discloses a hydraulic system for a winch, belonging to the field of hydraulic control. The hydraulic system includes a hydraulic pump module, a hydraulic motor module, and a control module. The hydraulic pump module includes a variable pump and a load sensing valve; the control module includes a reversing valve and a pressure compensator. The a oil port of the reversing valve is connected to the variable pump, the b oil port of the reversing valve is connected to the corresponding hydraulic motor module, the c oil port of the reversing valve is connected to the corresponding hydraulic motor module, the d oil port of the reversing valve is respectively connected to the first control oil port of the pressure compensator and the a oil port of the pressure compensator, the e oil port of the reversing valve is respectively connected to the c oil port of the pressure compensator and the f oil port of the reversing valve, the g oil port of the reversing valve is connected to the main oil return port of the hydraulic system, and the b oil port of the pressure compensator is respectively connected to the second control oil port of the pressure compensator and the second control oil port of the load sensing valve.

[0004] This document can avoid power loss of the hydraulic system. However, when the winch is on standby, the oil circuit of the hydraulic oil will not pass through the motor. Since the hydraulic pump of the pump station always needs to supply oil under high pressure, this is likely to increase the energy consumption of the winch. Summary of the Invention

[0005] The utility model provides a hydraulic unloading system. When the winch is on standby, the oil supplied by the hydraulic pump station can be unloaded and returned to the oil tank, so as to ensure that the oil circuit of the hydraulic system can circulate under low pressure, making the energy consumption of the hydraulic system smaller.

[0006] To achieve the above object, the technical solution of the present utility model is: an unloading hydraulic 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 the motor to rotate. The winch control system 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.

[0007] 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 changes direction, 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] In the above structure, the hydraulic pump station supplies oil to the motor to drive the motor. When the winch is started, by controlling the first control valve to change direction, the P port of the first control valve is communicated with the A port and the B port is communicated with the T port to control the motor to rotate forward, or the P port of the first control valve is communicated with the B port and the A port is communicated with the T port to control the motor to rotate backward, thereby realizing the control of the motor. Since a first center unloading valve is provided between the first oil supply pipeline and the first oil return pipeline, when the hydraulic pump station supplies oil, if the first control valve does not change direction, the hydraulic oil in the first oil supply pipeline flows into the first control end of the first center unloading valve at this time, so that the first center unloading valve is communicated, 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 changes direction, 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, so that 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 supply oil normally and drive the motor to rotate. Therefore, through the setting of the first center unloading valve, when the winch is on standby, the first center unloading valve is opened so that the hydraulic oil is unloaded through the first center 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 winch 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 motor normally for operation.

[0009] Further, a spring is also provided on the second control end of the first neutral unloading valve. 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.

[0010] With the above settings, the pressure of the hydraulic oil flowing into the first control end of the first neutral unloading valve is overcome by the spring plus the hydraulic oil pressure at the second control end, so as to ensure that the oil inlet end and the oil outlet end of the first neutral unloading valve are disconnected, and prevent the hydraulic oil from flowing back to the fuel tank from the first neutral unloading valve when the oil circuit is working properly.

[0011] 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.

[0012] With the above settings, by setting the first shuttle valve, the hydraulic oil flowing into the second control end of the first neutral unloading valve from the P1 end and the T1 end of the first control valve can be prevented from conflicting with each other.

[0013] Further, a first relief valve is provided between the second control end of the first neutral unloading valve and the first return oil pipeline. The oil inlet end of the first relief valve is connected to the second control end of the first neutral unloading valve, and the oil outlet end of the first relief valve is connected to the first return oil pipeline.

[0014] With the above settings, by setting the first relief valve, when the winch is on standby, the first relief valve is normally open when de-energized, so that the hydraulic oil is unloaded and the pressure is reduced through the first relief valve to achieve the low-pressure circulation of the hydraulic oil, thus playing an energy-saving role. When the winch is working, the first relief valve is energized and closed, so that the hydraulic oil is pressurized and enters the motor for work.

[0015] 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.

[0016] 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 the control of the winch.

[0017] Further, the hydraulic pump station includes a fuel 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 fuel tank, the oil outlet ends of the first oil pump and the second oil pump are connected to the first oil inlet pipeline through the oil outlet, and the first return oil pipeline is connected to the fuel tank through the oil return port.

[0018] With the above settings, by setting two oil pumps, the winch can operate at full load. 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. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a hydraulic schematic diagram of the unloading system of the present invention.

[0020] Figure 2 It is a hydraulic schematic diagram of the winch control system of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0021] The present invention will be further described in detail below with reference to the drawings and specific embodiments.

[0022] As Figures 1 to 2 shown, an unloading hydraulic system includes a hydraulic pump station 1 and a winch control system 2. The hydraulic pump station 1 supplies oil to the winch control system 2, and the winch control system 2 drives the motor 3 to rotate. The winch control system 2 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.

[0023] 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 switched, 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.

[0024] A spring 213 is further provided on the second control end 212 of the first center unloading valve 21. The spring 213 pushes the internal oil passage of the first center unloading valve 21 to disconnect the oil inlet end and the oil outlet end of the first center unloading valve 21. By the spring 213 plus the hydraulic oil pressure at the second control end 212 to overcome the pressure of the hydraulic oil flowing into the first control end 211 of the first center unloading valve 21, it is ensured that the oil inlet end and the oil outlet end of the first center unloading valve 21 are disconnected, preventing the hydraulic oil from flowing back to the fuel tank from the first center unloading valve 21 when the oil circuit is working properly.

[0025] A first shuttle valve 23 is provided between the P1 end and the T1 end 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 end of the first control valve 22, the second port 232 of the first shuttle valve 23 is connected to the T1 end 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. By providing the first shuttle valve 23, it is possible to prevent the hydraulic oil flowing from the P1 end and the T1 end of the first control valve 22 into the second control end 212 of the first neutral unloading valve 21 from conflicting with each other.

[0026] A first relief valve 24 is provided between the second control end 212 of the first neutral unloading valve 21 and the first return oil pipeline 13. The oil inlet end of the first relief 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 relief valve 24 is connected to the first return oil pipeline 13. By providing the first relief valve 24, when the winch is on standby, the first relief valve 24 is de-energized and normally open, so that the hydraulic oil is unloaded and the pressure is reduced through the first relief 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 relief valve 24 is energized and closed, so that the hydraulic oil is pressurized and enters the motor for work.

[0027] A first pressure reducing valve 25 is further 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 controlling the winch.

[0028] 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 through the oil outlet 11. The first return oil pipeline 13 is 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 run at half load by the other oil pump, preventing the winch from suddenly stopping and causing accidents.

[0029] Working principle of the utility model: The hydraulic pump station 1 supplies oil to the motor 3 to drive the motor 3. When starting the winch, by controlling the reversal of the first control valve 22, the P port of the first control valve 22 is connected to the A port and the B port is connected to the T port to control the forward rotation of the motor 3, or the P port of the first control valve 22 is connected to the B port and the A port is connected to the T port to control the reverse rotation of the motor 3, thereby realizing the control of the motor 3. Since the first neutral unloading valve 21 is provided between the first oil inlet pipe 12 and the first oil return pipe 13, when the hydraulic pump station 1 supplies oil, if the first control valve 22 does not reverse, at this time, the hydraulic oil in the first oil inlet pipe 12 flows into the first control end 211 of the first neutral unloading valve 21, so that the first neutral unloading valve 21 is connected, and the hydraulic oil can pass through the first neutral unloading valve 21 and then unload through the first oil return pipe 13 and flow back to the fuel tank 15; when the first control valve 22 reverses, 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 1 to the P port of the first control valve 22 can flow through the P1 port and the T1 port to the second control end 212 of the first neutral unloading valve 21. At this time, the hydraulic oil drives the first neutral unloading valve 21 to disconnect, so that the hydraulic oil cannot unload through the first neutral unloading valve 21, and the hydraulic oil can supply oil normally and drive the motor 3 to rotate. Thus, through the setting of the first neutral unloading valve 21, when the winch is on standby, the first neutral unloading valve 21 is opened to make the hydraulic oil unload through the first neutral unloading valve 21 and flow back to the fuel tank 15 to realize low-pressure circulation, so as to ensure that the energy consumption of the winch will not be too large. When the winch needs to work, the first neutral unloading valve 21 is controlled to disconnect by the hydraulic oil flowing to the first control valve 22, so that the hydraulic oil can flow to the motor normally for operation.

Claims

1. A load-unloading hydraulic 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 the motor to rotate, characterized in that: The winch control system includes a first neutral 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.

2. A unloading hydraulic 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.

3. A unloading hydraulic system according to claim 2, 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.

4. A unloading hydraulic 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.

5. The unloading hydraulic 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.

6. The unloading hydraulic 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 inlets of the first oil pump and the second oil pump are connected to the oil tank, the oil outlets of the first oil pump and the second oil pump are connected to a first oil inlet pipeline via an oil outlet, and the first oil return pipeline is connected to the oil tank via an oil return port.

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