Vehicle cargo bed lifting system and vehicle cargo bed lifting method

Abstract

The application discloses a vehicle cargo compartment lifting system and a vehicle cargo compartment lifting method. The vehicle cargo compartment lifting system comprises a lifting pump, a pilot oil supply valve, a hydraulic control lifting valve, a lifting oil cylinder, a lifting handle and a controller. The pilot oil supply valve comprises a first proportional electromagnetic valve and a second proportional electromagnetic valve. The hydraulic control lifting valve comprises a main valve. The main valve is a proportional reversing valve. An oil outlet of the lifting pump is connected to the main valve. The lifting pump is connected to the first proportional electromagnetic valve and the second proportional electromagnetic valve respectively. The first proportional electromagnetic valve and the second proportional electromagnetic valve are connected to the main valve respectively. The lifting oil cylinder is connected to the main valve. The controller is used for sending proportional current signals to the first proportional electromagnetic valve and the second proportional electromagnetic valve according to a linear control instruction received by the lifting handle, and then outputting pilot oil to the main valve to control the state of the main valve. The technical scheme can proportionally adjust the opening degree of the main valve, thereby controlling the lifting speed of the lifting oil cylinder and realizing precise control during lifting and lowering of the vehicle cargo compartment.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of vehicles, in particular to a vehicle cargo compartment lifting system and a vehicle cargo compartment lifting method. BACKGROUND

[0002] The mine dump truck is used for mining and transporting ore in mines, and transports untreated ore loaded on the cargo compartment to fixed crushing points, etc., and completes production work by pouring ore through the lifting and lowering of the cargo compartment. Generally, the mine dump truck is provided with a lifting cylinder on each side of the frame or in front of the cargo compartment, and the lifting and lowering of the cargo compartment are realized by the telescopic lifting cylinder.

[0003] At present, the lifting system of the mine dump truck is gas-controlled pilot lifting, which belongs to on-off control. The opening size of the lifting valve spool cannot be accurately controlled by the pulling angle of the lifting handle, and the lifting speed of the oil cylinder can only be controlled by the accelerator pedal. Precise control cannot be achieved for the lifting speed below idle speed. The cargo compartment cannot be accurately and slowly lifted to the specified installation position during assembly, and the current lifting system cannot meet the requirement of precise and slow lifting, resulting in low assembly efficiency of the cargo compartment. SUMMARY

[0004] Therefore, the purpose of the present application is to provide a vehicle cargo compartment lifting system and a vehicle cargo compartment lifting method capable of accurately controlling the lifting speed.

[0005] To achieve the above purpose, the present application provides a vehicle cargo compartment lifting system, comprising a lifting pump, a pilot oil supply valve, a hydraulic control lifting valve, a lifting oil cylinder, a lifting handle and a controller. The pilot oil supply valve comprises a first proportional electromagnetic valve and a second proportional electromagnetic valve. The hydraulic control lifting valve comprises a main valve. The main valve is a proportional directional valve. The oil outlet of the lifting pump is connected to the main valve to supply oil to the main valve. The lifting pump is connected to the first proportional electromagnetic valve and the second proportional electromagnetic valve, respectively. The first proportional electromagnetic valve and the second proportional electromagnetic valve are connected to the first control end and the second control end of the main valve, respectively, to output pilot oil to the first control end and the second control end of the main valve. The lifting oil cylinder is connected to the main valve. The controller is connected to the lifting handle. The controller is also connected to the control end of the first proportional electromagnetic valve and the second proportional electromagnetic valve. The controller is used to send proportional current signals to the first proportional electromagnetic valve and the second proportional electromagnetic valve according to the linear control instructions received by the lifting handle, and then output pilot oil to the main valve to control the state of the main valve.

[0006] Optionally, the pilot oil supply valve further comprises a shuttle valve, two oil inlets of the shuttle valve are connected to the first oil inlet and the second oil inlet respectively, and an oil outlet of the shuttle valve is connected to the first proportional electromagnetic valve and the second proportional electromagnetic valve.

[0007] Optionally, the pilot oil supply valve further comprises a pressure reducing valve, one end of the pressure reducing valve is connected to the oil outlet of the shuttle valve, and the other end of the pressure reducing valve is connected to the first proportional electromagnetic valve and the second proportional electromagnetic valve.

[0008] Optionally, the pilot oil supply valve further comprises a first overflow valve, one end of the first overflow valve is connected to the pressure reducing valve, and the other end of the first overflow valve is connected to a first oil return port of the pilot oil supply valve, the first oil return port being connected to an oil tank; the pilot oil supply valve further comprises an accumulator, the accumulator being connected to an oil inlet of the first overflow valve and an oil circuit between the first proportional electromagnetic valve and the second proportional electromagnetic valve.

[0009] Optionally, the first proportional electromagnetic valve and the second proportional electromagnetic valve each comprise a first proportional oil port, a second proportional oil port and a third proportional oil port, the first proportional oil port of the first proportional electromagnetic valve and the second proportional electromagnetic valve is connected to the lift pump and the steering pump through the shuttle valve, the second proportional oil port of the first proportional electromagnetic valve and the second proportional electromagnetic valve is connected to the first oil return port of the pilot oil supply valve, the third proportional oil port of the first proportional electromagnetic valve is connected to a first control end of the main valve, and the third proportional oil port of the second proportional electromagnetic valve is connected to a second control end of the main valve; the first proportional electromagnetic valve and the second proportional electromagnetic valve each comprise a first position and a second position, in the first position, the first proportional oil port and the third proportional oil port are disconnected, and the second proportional oil port and the third proportional oil port are connected, and in the second position, the first proportional oil port and the third proportional oil port are connected, and the second proportional oil port and the third proportional oil port are disconnected.

[0010] Optionally, the main valve includes a first port, a second port, a third port, and a fourth port. The first port and the second port are connected to the outlet of the lifting pump, the third port is connected to the second return port of the hydraulic lifting valve, and the fourth port is connected to the rodless chamber of the lifting cylinder. The main valve has a third position and a fourth position. In the third position, both the first port and the second port are connected to the third port, and both the first port and the second port are disconnected from the fourth port. In the fourth position, both the first port and the second port are disconnected from the third port, and both the first port and the second port are connected to the fourth port. The opening degree of the main valve is different when it is in the third position and the fourth position.

[0011] Optionally, the vehicle cargo box lifting system further includes a power take-off (PTO) and a PTO switch. The PTO is connected to the lifting pump, and the PTO switch is connected to the controller. The PTO switch is used to transmit a received activation signal to the controller, and the controller is used to control whether the PTO takes power from the power source to drive the lifting pump according to the activation signal.

[0012] Optionally, the vehicle cargo box lifting system further includes a lifting limit switch connected to the controller. The controller is used to control the power take-off to not draw power from the power source when the lifting limit switch is triggered, thereby stopping the lifting pump from working. The controller is also used to stop transmitting linear control commands to the first proportional solenoid valve when the lifting limit switch is triggered, thereby controlling the main valve to switch states and stop supplying oil to the lifting cylinder.

[0013] Optionally, the vehicle cargo box lifting system further includes a descent limit switch connected to the controller. The controller is used to stop transmitting linear control commands to the second proportional solenoid valve when the descent limit switch is triggered, thereby stopping the supply of pilot oil to the main valve.

[0014] This application also provides a vehicle cargo box lifting method, applied to a vehicle cargo box lifting system, characterized in that the vehicle cargo box lifting method includes:

[0015] When the lifting oil cylinder is lifted, the lifting handle receives a lifting operation instruction and transmits the lifting operation instruction to the controller, the controller outputs a lifting proportional current signal to the first proportional solenoid valve of the pilot oil supply valve according to the lifting operation instruction, the first proportional solenoid valve outputs a pilot oil pressure of a corresponding size according to the lifting proportional current signal, thereby controlling the switching state of the main valve, causing the spool of the main valve to move a corresponding displacement according to the size of the pilot oil pressure, thereby controlling the amount of oil flowing into the rodless chamber of the lifting oil cylinder through the main valve, and further controlling the lifting speed of the lifting oil cylinder, the power take-off switch receives an opening signal and transmits the opening signal to the controller, and the controller receives the opening signal of the power take-off switch and outputs an electric signal to control the power take-off to take power from the power source and drive the lifting pump to start working.

[0016] When the lifting oil cylinder triggers the lifting limit switch, the controller sends an electric signal after receiving that the lifting limit switch is triggered, stops outputting the current signal to the first proportional solenoid valve to make the main valve maintain the current state, and controls the power take-off switch to be closed, thereby making the power take-off disengage with the gearbox, the lifting pump stops working, and the lifting oil cylinder maintains the state.

[0017] When the lifting oil cylinder is lowered, the cargo compartment is automatically lowered under the action of its own weight, the lifting handle receives a lowering operation instruction and transmits the lowering operation instruction to the controller, the controller outputs a lowering proportional current signal to the second proportional solenoid valve of the pilot oil supply valve according to the lowering operation instruction, the second proportional solenoid valve outputs a pilot oil pressure of a corresponding size according to the lowering proportional current signal, thereby controlling the switching state of the main valve, causing the spool of the main valve to move a corresponding displacement according to the size of the pilot oil pressure, thereby controlling the amount of oil flowing out of the rodless chamber of the lifting oil cylinder, and further controlling the lowering speed of the lifting oil cylinder.

[0018] From the above, the vehicle cargo compartment lifting system and the vehicle cargo compartment lifting method of the present application can switch the states of the first proportional solenoid valve and the second proportional solenoid valve according to the linear control instruction, thereby controlling the state of the main valve of the hydraulic control lifting valve, making the main valve proportional regulation opening degree, and thereby controlling the lifting speed of the lifting oil cylinder, to realize precise control of the vehicle cargo compartment lifting and lowering. BRIEF DESCRIPTION OF DRAWINGS

[0019] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can also be obtained without creative labor on the basis of these drawings.

[0020] Figure 1A structural schematic diagram of a vehicle cargo compartment lifting system provided by an embodiment of the present application is shown.

[0021] Figure 2 For Figure 1 A structural schematic diagram of a pilot oil supply valve of the vehicle cargo compartment lifting system is shown.

[0022] Figure 3 For Figure 1 A structural schematic diagram of a hydraulic control lifting valve of the vehicle cargo compartment lifting system is shown. DETAILED DESCRIPTION

[0023] The specific embodiments of the present application will be described in detail hereinafter with reference to the drawings. Obviously, the described embodiments are only part of the embodiments of the present application, but not all the embodiments. Based on the description of the present application, all the other embodiments obtained by those of ordinary skill in the art without creative work fall within the scope of the present application.

[0024] In the description of the present application, unless otherwise explicitly specified and limited, the terms "set", "install", "connect" and the like should be understood in a broad sense, for example, can be fixedly connected, can be detachably connected, or integrally connected; can be mechanically connected, or electrically connected; can be directly connected, or indirectly connected through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms can be understood according to the specific circumstances.

[0025] The terms "first", "second", "third" and the like are only used to distinguish similar attributes or elements, and do not indicate or imply relative importance or a specific order.

[0026] The terms "include", "contain" or any other variants thereof are intended to cover non-exclusive inclusion, in addition to containing the listed elements, other elements not explicitly listed can also be contained.

[0027] Figure 1 A structural schematic diagram of a vehicle cargo compartment lifting system provided by an embodiment of the present application is shown. As Figure 1 As shown, the vehicle cargo compartment lifting system of the present application includes a lifting pump 11, a pilot oil supply valve 13, a hydraulic control lifting valve 15, a lifting oil cylinder 17, a lifting handle 19 and a controller 21, please refer to Figure 2The pilot oil supply valve 13 comprises a first proportional solenoid valve 131 and a second proportional solenoid valve 132, and the hydraulic control lifting valve 15 comprises a main valve 151 which is a proportional reversing valve. The outlet of the lifting pump 11 is connected to the pilot oil supply valve 13 and the main valve 151 to supply oil to the pilot oil supply valve 13 and the main valve 151. The lifting pump 11 is connected to the first proportional solenoid valve 131 and the second proportional solenoid valve 132 respectively, and the first proportional solenoid valve 131 and the second proportional solenoid valve 132 are connected to the first control end and the second control end of the main valve 151 respectively to output pilot oil to the first control end and the second control end of the main valve 151. The lifting cylinder 17 is connected to the main valve 151, and the controller 21 is connected to the lifting handle 19 and the control ends of the first proportional solenoid valve 131 and the second proportional solenoid valve 132. The controller 21 is used to send proportional current signals to the first proportional solenoid valve 131 and the second proportional solenoid valve 132 according to the linear control instructions received by the lifting handle 19, and then output pilot oil to the main valve 151 to control the state of the main valve 151.

[0028] In the vehicle cargo compartment lifting system of the embodiment, the states of the first proportional solenoid valve and the second proportional solenoid valve can be switched according to the linear control instructions, thereby controlling the state of the main valve of the hydraulic control lifting valve, adjusting the proportional opening degree of the main valve, and controlling the lifting speed of the lifting cylinder, so as to realize precise control of the vehicle cargo compartment during lifting and lowering.

[0029] In the embodiment, the pilot oil supply valve 13 comprises a first oil inlet and a second oil inlet, the first oil inlet is connected to the outlet of the lifting pump 11, and the second oil inlet is connected to the outlet of a steering pump (not shown). The pilot oil supply valve 13 further comprises a shuttle valve 134, two oil inlets of the shuttle valve 134 are connected to the first oil inlet and the second oil inlet respectively, and the outlet of the shuttle valve 134 is connected to the first proportional solenoid valve 131 and the second proportional solenoid valve 132. When the system is started for the first time, the spool of the main valve 151 of the hydraulic control lifting valve 15 is located at the middle position, and the lifting pump 11 is in an unloading state and cannot provide a pilot oil source for the pilot oil supply valve 13. At this time, the steering system can provide a pilot oil source for the pilot oil supply valve 13 through the shuttle valve 134. It can be understood that the pilot oil supply valve 13 can also not be supplied with oil by the lifting pump 11 and the steering pump, but can be supplied with pilot oil by other hydraulic pumps, such as a special pilot pump.

[0030] In the embodiment, the pilot oil supply valve 13 further comprises a pressure reducing valve 136, one end of the pressure reducing valve 136 is connected to the outlet of the shuttle valve 134, and the other end of the pressure reducing valve 136 is connected to the first proportional solenoid valve 131 and the second proportional solenoid valve 132. The pressure reducing valve 136 can reduce the pressure oil provided by the lifting pump 11 or the steering pump to a suitable pilot pressure and stabilize the pilot pressure.

[0031] In this embodiment, the pilot oil supply valve 13 further includes a first relief valve 138. One end of the first relief valve 138 is connected to the pressure reducing valve 136, and the other end is connected to the first return port 139 of the pilot oil supply valve 13. The first return port 139 is connected to the oil tank. When the pressure reducing valve 136 fails or the system experiences impact pressure, the first relief valve 138 can provide protection.

[0032] In this embodiment, the pilot fuel supply valve 13 further includes an accumulator 141, which is connected to the oil circuit between the oil inlet of the first overflow valve 138 and the first proportional solenoid valve 131 and the second proportional solenoid valve 132. The accumulator 141 can absorb shocks, stabilize the pilot oil circuit supply pressure, and provide a pilot power oil source when the vehicle is turned off.

[0033] In this embodiment, both the first proportional solenoid valve 131 and the second proportional solenoid valve 132 include a first proportional port 1311, a second proportional port 1312, and a third proportional port 1313. The first proportional ports 1311 of both valves are connected to the lifting pump 11 and the steering pump via a pressure reducing valve 136 and a shuttle valve 134. The second proportional ports 1312 of both valves are connected to a first return port 139. The third proportional port 1313 of the first proportional solenoid valve 131 is connected to the first control terminal of the main valve 151, and the third proportional port 1313 of the second proportional solenoid valve 132 is connected to the second control terminal of the main valve 151. Both the first and second proportional solenoid valves 131 and 132 include a first position and a second position. The first position (… Figure 2 When the upper position is shown, the first proportional oil port 1311 and the third proportional oil port 1313 are disconnected, and the second proportional oil port 1312 and the third proportional oil port 1313 are connected. The second position ( Figure 2 When in the lower position (as shown), the first proportional oil port 1311 and the third proportional oil port 1313 are connected, while the second proportional oil port 1312 and the third proportional oil port 1313 are disconnected. Furthermore, in the second position, the valve core has different opening degrees when it is in different positions, which allows the first proportional solenoid valve 131 and the second proportional solenoid valve 132 to output different pilot oil pressures.

[0034] In this embodiment, please refer to the following: Figure 3 The main valve 151 of the hydraulic lifting valve 15 includes a first port 1511, a second port 1512, a third port 1513, and a fourth port 1514. The first and second ports 1511 and 1512 are connected to the outlet of the lifting pump 11, the third port 1513 is connected to the second return port 153 of the hydraulic lifting valve 15, and the fourth port 1514 is connected to the rodless chamber of the lifting cylinder 17. The main valve 151 includes a third position and a fourth position. The third position ( Figure 3When the first position (as shown on the left) is reached, the first oil port 1511 and the second oil port 1512 are both communicated with the third oil port 1513, and the first oil port 1511 and the second oil port 1512 are both disconnected from the fourth oil port 1514. When the fourth position (as shown on the right) is reached, the first oil port 1511 and the second oil port 1512 are both disconnected from the third oil port 1513, and the first oil port 1511 and the second oil port 1512 are both communicated with the fourth oil port 1514. The opening degrees of the third position and the fourth position of the main valve 151 of the hydraulic control lifting valve 15 are both variable, that is, the opening degree of the main valve 151 is different when the main valve 151 is located at different positions of the third position and the fourth position, so that different flow rates of oil can be achieved at different positions to realize proportional control. Figure 3

[0035] Specifically, the hydraulic control lifting valve 15 further comprises a pilot relief valve 155, which is arranged between the oil outlet of the lifting pump 11 and the second oil return port 153 to achieve relief.

[0036] Specifically, the second oil return port 153 returns oil through the filter 25.

[0037] In this embodiment, when the rodless chamber of the lifting oil cylinder 17 is filled with oil, the lifting oil cylinder 17 extends, and the cargo compartment is lifted. When the oil in the rodless chamber of the lifting oil cylinder 17 is maintained and no new oil enters the rodless chamber, the cargo compartment is maintained in the lifted state. When the oil in the rodless chamber of the lifting oil cylinder 17 is returned through the main valve 15, the lifting oil cylinder 17 retracts, and the cargo compartment falls.

[0038] In this embodiment, the vehicle cargo compartment lifting system further comprises a power take-off 27 and a power take-off switch 29. The power take-off 27 is connected to the lifting pump 11, and the power take-off switch 29 is connected to the controller 21. The power take-off switch 29 is used to transmit the received opening signal to the controller 21. The controller 21 is used to control whether the power take-off 27 is driven by the power source to drive the lifting pump 11 to work according to the opening signal. When the power take-off switch 29 is pressed, the controller 21 receives the lifting instruction transmitted by the power take-off switch 29 and outputs an electric signal, so as to control the power take-off 27 to engage with the gearbox and start rotating, thereby driving the lifting pump 11 to work. When the controller 21 receives the signal that the lifting oil cylinder is lifted to the position, the controller 21 outputs an electric signal, so as to control the power take-off 27 to disengage from the gearbox, thereby stopping the lifting pump 11 from working, and the lifting oil cylinder 17 can be maintained in the current lifted state. In this way, when the lifting oil cylinder 17 stops lifting and is in the maintaining state, the lifting pump 11 can be stopped to work to save energy.

[0039] ​In this embodiment, the vehicle cargo compartment lifting system further comprises a lifting limit switch 31 connected to the controller 21, the controller 21 is configured to control the power take-off 27 to disengage from the gearbox (i.e. control the power take-off 27 to not take power from the power source) when the lifting limit switch 31 is triggered, so as to stop the lifting pump 11 from working, and the controller 21 is further configured to stop sending linear control instructions to the first proportional electromagnetic valve 131 of the pilot oil supply valve 13 when the lifting limit switch 31 is triggered, so as to control the main valve 151 of the hydraulic control lifting valve 15 to switch state and stop supplying oil to the lifting oil cylinder 17.

[0040] In this embodiment, the vehicle cargo compartment lifting system further comprises a lowering limit switch 33 connected to the controller 21, the controller 21 is configured to stop sending linear control instructions to the second proportional electromagnetic valve 132 of the pilot oil supply valve 13 when the lowering limit switch 33 is triggered, so as to stop providing pilot oil to the main valve 151.

[0041] The working principle of the vehicle cargo compartment lifting system in this embodiment is described below.

[0042] When the lifting oil cylinder 17 needs to be lifted, the operator presses the power take-off switch 29, the controller 21 receives the opening signal of the power take-off switch 29 and outputs an electric signal, so that the power take-off 27 engages with the gearbox and starts to rotate, driving the lifting pump 11 to start working, at the same time, the operator operates the lifting handle 19 to the lifting position, the handle from the minimum opening to the maximum opening corresponds to the linear output of 0-1000 CAN bus digital signal into the controller 21, the controller 21 receives the linear proportional control signal of the lifting handle 19, and converts and outputs the corresponding proportional current signal to the first proportional electromagnetic valve 131 of the electric pilot oil supply valve 13, the first proportional electromagnetic valve 131 outputs different pilot oil pressures under different current signals. The pilot oil pressure pushes the spool of the main valve 151 of the hydraulic control lifting valve 15 to move to the right, and the linear proportional control signal of the lifting handle 19 determines the size of the pilot oil pressure, and the size of the pilot oil pressure determines the linear displacement of the spool of the main valve 151, and the hydraulic oil provided by the lifting pump 11 is linearly distributed into the lifting oil cylinder 17 according to the opening size of the lifting handle 19, thereby controlling the lifting speed of the lifting oil cylinder 17.

[0043] When the lifting oil cylinder 17 rises to the set height, the lifting limit switch 31 is triggered. After the controller 21 receives the electric signal that the lifting limit switch 31 is triggered, it immediately stops outputting the current signal to the first proportional electromagnetic valve 131 of the pilot oil supply valve 13, and closes the power take-off switch 29, the first control end of the main valve 151 returns to oil, the spool of the first proportional electromagnetic valve 131 returns to the upper position under the action of the return spring, at the same time, the power take-off 27 disengages from the gearbox, the lifting pump 11 stops working, and the vehicle stops lifting and is in a holding state.

[0044] When the lifting cylinder 17 needs to be lowered, the operator operates the lifting handle 19 to the lowering position, and the cargo compartment is automatically lowered under the action of its own weight. The handle is from the minimum opening to the maximum opening, and the CAN bus digital signal corresponding to the linear output 0-1000 enters the controller 21. The controller 21 receives the linear proportional control signal of the lifting handle 19, converts the output corresponding proportional current signal to the second proportional solenoid valve 132 of the pilot oil supply valve 13, and the second proportional solenoid valve 132 outputs different pilot oil pressure under different current signals. The pilot oil pressure reaches the second control end of the main valve 151 to push the spool of the main valve 151 to move to the left. The linear proportional control signal of the lifting handle 19 determines the size of the pilot oil pressure, and the size of the pilot oil pressure determines the linear displacement size of the spool of the main valve of the hydraulic control lifting valve 15. Thus, with the opening size of the lifting handle 19, the lowering speed of the linear control lifting cylinder 17 is controlled.

[0045] When the cargo compartment is lowered to the frame, the lowering limit switch 33 is triggered, and the controller 21 receives the electrical signal sent by the lowering limit switch 33 and immediately stops the current signal output to the second proportional solenoid valve 132 of the pilot oil supply valve 13. The second proportional solenoid valve 132 returns to the upper position, and no pilot oil flows into the second control end of the main valve 151. At this time, the power takeoff 27 has been disconnected from the engagement with the transmission, the lifting pump 11 no longer supplies oil, and the main valve 151 is also in the left position. The rodless chamber of the lifting cylinder 17 is not in communication with the oil outlet of the lifting pump 11.

[0046] The application also provides a vehicle cargo compartment lifting method applied to control the above-mentioned vehicle cargo compartment lifting system. The vehicle cargo compartment lifting method comprises the following steps:

[0047] S11, when lifting the lifting cylinder 17, the lifting handle 19 receives the lifting operation instruction and transmits it to the controller 21. The controller 21 outputs the lifting proportional current signal to the first proportional solenoid valve 131 of the pilot oil supply valve 13 according to the lifting operation instruction. The first proportional solenoid valve 131 outputs the pilot oil pressure of the corresponding size according to the lifting proportional current signal, thereby controlling the switching state of the main valve 151, making the spool of the main valve 151 move the corresponding displacement according to the size of the pilot oil pressure, thereby controlling the oil amount of the lifting pump 11 flowing into the rodless chamber of the lifting cylinder 17 through the main valve 151, and further controlling the lifting speed of the lifting cylinder 17. Specifically, step S11 further comprises: the power takeoff switch 29 receives the opening signal and transmits it to the controller 21. The controller 21 receives the opening signal of the power takeoff switch 29 and outputs an electrical signal to control the power takeoff 27 to engage with the transmission and start rotating (i.e. the power takeoff 27 takes power from the power source), thereby driving the lifting pump 11 to start working.

[0048] S13, when the lifting cylinder 17 triggers the lifting limit switch 31, the controller 21 receives the electrical signal from the lifting limit switch 31 and stops the first proportional solenoid valve 131 of the pilot oil supply valve 13 from outputting the current signal, so that the main valve 151 remains in the current state, and controls the power take-off switch 29 to be closed, so that the power take-off 27 is disconnected from the gearbox, the lifting pump 11 stops working, and the lifting cylinder 17 remains in the current state.

[0049] S15, when the lifting cylinder 17 is lowered, the cargo compartment is automatically lowered under the action of its own weight, the lifting handle 19 receives the lowering operation instruction and transmits it to the controller 21, the controller 21 outputs a lowering proportional current signal to the second proportional solenoid valve 132 of the pilot oil supply valve 13 according to the lowering operation instruction, the second proportional solenoid valve 132 outputs a corresponding size of pilot oil pressure according to the lowering proportional current signal, so as to control the main valve 151 to switch state, so that the spool of the main valve 151 moves a corresponding displacement according to the size of the pilot oil pressure, thereby controlling the oil amount of the oil flowing out of the rodless cavity of the lifting cylinder 17, and further controlling the lowering speed of the lifting cylinder 17.

[0050] In step S15, when the cargo compartment is lowered onto the frame, the lowering limit switch 33 is triggered, and the controller 21 stops outputting the current signal to the second proportional solenoid valve 132 of the pilot oil supply valve 13 after receiving the electrical signal from the lowering limit switch 33.

[0051] The above is only a specific embodiment of the present application, but the protection scope of the present application is not limited thereto, any person skilled in the art can easily think of changes or replacements within the technical scope disclosed in the present application, which should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the appended claims.

Claims

1. A vehicle cargo bed lifting system, characterized by, The lifting pump (11), the pilot oil supply valve (13), the hydraulic control lifting valve (15), the lifting oil cylinder (17), the lifting handle (19) and the controller (21), the pilot oil supply valve (13) includes the first proportional solenoid valve (131) and the second proportional solenoid valve (132), the hydraulic control lifting valve (15) includes the main valve (151), the main valve (151) is a proportional reversing valve, the oil outlet of the lifting pump (11) is connected to the main valve (151) to supply oil to the main valve (151), the lifting pump (11) is connected to the first proportional solenoid valve (131) and the second proportional solenoid valve (132) respectively, the first proportional solenoid valve (131) and the second proportional solenoid valve (132) are connected to the first control end and the second control end of the main valve (151) respectively to output pilot oil to the first control end and the second control end of the main valve (151), the lifting oil cylinder (17) is connected to the main valve (151), the controller (21) is connected to the lifting handle (19), the controller (21) is also connected to the control end of the first proportional solenoid valve (131) and the second proportional solenoid valve (132), the controller (21) is used for sending proportional current signals to the first proportional solenoid valve (131) and the second proportional solenoid valve (132) according to the linear control instruction received by the lifting handle (19), and then outputting pilot oil to the main valve (151) to control the state of the main valve (151); The pilot oil supply valve (13) includes a first oil inlet and a second oil inlet, the first oil inlet is connected to the oil outlet of the lifting pump (11), the second oil inlet is connected to the oil outlet of the steering pump, the pilot oil supply valve (13) further includes a shuttle valve (134), two oil inlets of the shuttle valve (134) are connected to the first oil inlet and the second oil inlet respectively, and the oil outlet of the shuttle valve (134) is connected to the first proportional solenoid valve (131) and the second proportional solenoid valve (132).

2. The vehicle cargo box lift system of claim 1, wherein, The pilot oil supply valve (13) further includes a pressure reducing valve (136), one end of the pressure reducing valve (136) is connected to the oil outlet of the shuttle valve (134), and the other end is connected to the first proportional solenoid valve (131) and the second proportional solenoid valve (132).

3. The vehicle cargo box lift system of claim 2, wherein, The pilot oil supply valve 13 further includes a first overflow valve (138), one end of the first overflow valve (138) is connected to the pressure reducing valve (136), and the other end is connected to the first oil return port (139) of the pilot oil supply valve (13), and the first oil return port (139) is connected to the oil tank; the pilot oil supply valve (13) further includes an accumulator (141), and the accumulator (141) is connected to the oil inlet of the first overflow valve (138) and the oil circuit between the first proportional solenoid valve (131) and the second proportional solenoid valve (132).

4. The vehicle cargo bed lift system of claim 1, wherein, The first proportional electromagnetic valve (131) and the second proportional electromagnetic valve (132) each include a first proportional oil port (1311), a second proportional oil port (1312) and a third proportional oil port (1313), the first proportional oil port (1311) of the first proportional electromagnetic valve (131) and the second proportional electromagnetic valve (132) is connected to the lifting pump (11) and the steering pump through the shuttle valve (134), the second proportional oil port (1312) of the first proportional electromagnetic valve (131) and the second proportional electromagnetic valve (132) is connected to the first return oil port (139) of the pilot oil supply valve (13), the third proportional oil port (1313) of the first proportional electromagnetic valve (131) is connected to the first control end of the main valve (151), and the third proportional oil port (1313) of the second proportional electromagnetic valve (132) is connected to the second control end of the main valve (151); the first proportional electromagnetic valve (131) and the second proportional electromagnetic valve (132) each include a first position and a second position, when the first position, the first proportional oil port (1311) and the third proportional oil port (1313) are disconnected, and the second proportional oil port (1312) and the third proportional oil port (1313) are communicated, when the second position, the first proportional oil port (1311) and the third proportional oil port (1313) are communicated, and the second proportional oil port (1312) and the third proportional oil port (1313) are disconnected.

5. The vehicle cargo box lift system of claim 4, wherein, The main valve (151) includes a first oil port (1511), a second oil port (1512), a third oil port (1513) and a fourth oil port (1514), the first oil port (1511) and the second oil port (1512) are connected to the oil outlet of the lifting pump (11), the third oil port (1513) is connected to the second return oil port (153) of the hydraulic control lifting valve (15), and the fourth oil port (1514) is connected to the rodless cavity of the lifting oil cylinder (17); the main valve (151) includes a third position and a fourth position, when the third position, the first oil port (1511) and the second oil port (1512) are communicated with the third oil port (1513), and the first oil port (1511) and the second oil port (1512) are disconnected with the fourth oil port (1514), when the fourth position, the first oil port (1511) and the second oil port (1512) are disconnected with the third oil port (1513), and the first oil port (1511) and the second oil port (1512) are communicated with the fourth oil port (1514); the opening degree of the main valve (151) is different when the main valve (151) is located at different positions of the third position and the fourth position.

6. The vehicle cargo bed lift system of claim 1, wherein, The vehicle cargo compartment lifting system further comprises a power take-off (27) connected to the lifting pump (11) and a power take-off switch (29) connected to the controller (21), the power take-off switch (29) being configured to transmit a received start signal to the controller (21), and the controller (21) being configured to control the power take-off (27) to take power from a power source to drive the lifting pump (11) to work according to the start signal.

7. The vehicle cargo box lift system of claim 6, wherein, The vehicle cargo compartment lifting system further comprises a lifting limit switch (31) connected to the controller (21), the controller (21) being configured to control the power take-off (27) to not take power from the power source when the lifting limit switch (31) is triggered, so as to stop the lifting pump (11) from working, and the controller (21) being further configured to stop transmitting a linear control instruction to the first proportional electromagnetic valve (131) when the lifting limit switch (31) is triggered, so as to control the main valve (151) to switch state and stop supplying oil to the lifting cylinder (17).

8. The vehicle cargo bed lift system of claim 1, wherein, The vehicle cargo compartment lifting system further comprises a lowering limit switch (33) connected to the controller (21), the controller (21) being configured to stop transmitting a linear control instruction to the second proportional electromagnetic valve (132) when the lowering limit switch (33) is triggered, so as to stop supplying pilot oil to the main valve (151).

9. A vehicle cargo bed lifting method applied to control the vehicle cargo bed lifting system according to claim 7, characterized by, The vehicle cargo compartment lifting method comprises: When lifting the lifting cylinder (17), the lifting handle (19) receives a lifting operation instruction and transmits it to the controller (21), the controller (21) outputs a lifting proportional current signal to the first proportional electromagnetic valve (131) of the pilot oil supply valve (13) according to the lifting operation instruction, the first proportional electromagnetic valve (131) outputs a pilot oil pressure of a corresponding size according to the lifting proportional current signal, so as to control the main valve (151) to switch state, the spool of the main valve (151) moves a corresponding displacement according to the size of the pilot oil pressure, so as to control the amount of oil flowing into the rodless chamber of the lifting cylinder (17) through the main valve (151) by the lifting pump (11), and further control the ascending speed of the lifting cylinder (17), the power take-off switch (29) receives a start signal and transmits it to the controller (21), the controller (21) receives the start signal of the power take-off switch (29) and outputs an electric signal, and controls the power take-off (27) to take power from a power source to drive the lifting pump (11) to start working; When the lifting oil cylinder (17) triggers the lifting limit switch (31), the controller (21) receives the electrical signal sent by the lifting limit switch (31) after being triggered, stops the current signal output of the first proportional electromagnetic valve (131) to make the main valve (151) maintain the current state, and controls the take-off switch (29) to be closed, so that the take-off device (27) is disconnected from the gearbox, the lifting pump (11) stops working, and the lifting oil cylinder (17) maintains the state; When the lifting oil cylinder (17) is lowered, the cargo compartment is automatically lowered under the action of its own weight, the lifting handle (19) receives the lowering operation instruction and transmits it to the controller (21), the controller (21) outputs a lowering proportional current signal to the second proportional electromagnetic valve (132) of the pilot oil supply valve (13) according to the lowering operation instruction, the second proportional electromagnetic valve (132) outputs a pilot oil pressure of a corresponding size according to the lowering proportional current signal, thereby controlling the main valve (151) to switch states, making the spool of the main valve (151) move a corresponding displacement according to the size of the pilot oil pressure, thereby controlling the oil amount of the oil flowing out of the rodless cavity of the lifting oil cylinder (17), and further controlling the lowering speed of the lifting oil cylinder (17).

Images