Electric control lifting valve group for tractor and lifting system control method

Abstract

The invention belongs to the technical field of tractor equipment, and particularly relates to an electric control lifting valve group for a tractor and a lifting system control method. An inlet of an electromagnetic flow control valve of the electric control lifting valve group for the tractor is connected to a valve group oil inlet, a first oil supply channel and a second oil supply channel are arranged between a first outlet and a second outlet of the electromagnetic flow control valve and a valve body oil inlet of an electric control reversing valve module respectively, and the second oil supply channel is connected with an electromagnetic flow adjusting valve in series. A lifting oil port connecting channel and a descending oil port connecting channel are arranged between a first working oil port and a lifting oil port of the electric control reversing valve module and between a second working oil port and a descending oil port of the electric control reversing valve module respectively, and the lifting oil port connecting channel is connected with a proportional reversing valve in series. The control method of the tractor lifting system comprises the steps of lifting control, descending control, downward pressure control during working and floating control of the farm tool. The problem that an existing electric control lifting valve set for the tractor cannot adjust the flow according to use requirements is solved, and the operation efficiency is effectively improved.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of tractor equipment, and particularly relates to an electric control poppet valve group for tractors and a poppet system control method. BACKGROUND

[0002] At present, a tractor is an important agricultural mechanical equipment, which is used for traction and driving of seeding machines, rotary cultivators, furrow forming and ridging machines and other agricultural tools to complete plowing work. The functions of the agricultural tools, such as lifting, self-weight lowering, forced lowering and floating, are realized by controlling the lifting oil cylinder through the electric control poppet valve group. The flow of the existing electric control poppet valve group for tractors is small, and only simple driving functions can be realized. The speed and size of the lifting, self-weight lowering and forced lowering actions of the agricultural tools and the down pressure of the agricultural tools during work cannot be adjusted according to the actual use requirements, and the use is very inconvenient. SUMMARY

[0003] The present application aims to solve the problem that the existing electric control poppet valve group for tractors cannot adjust the flow according to the use requirements. The user can adjust the flow of the electric control poppet valve group for tractors according to the use requirements to realize the adjustment of the speed of the lifting, self-weight lowering and forced lowering actions of the agricultural tools and the down pressure of the agricultural tools during work, thereby effectively improving the work efficiency.

[0004] The present application discloses an electric control poppet valve group for tractors, which comprises a valve body, a valve group oil inlet, a lifting oil port, a lowering oil port and a valve group oil return port are arranged on the valve body, further comprises an electromagnetic flow control valve, an electric control reversing valve module, an electromagnetic flow regulating valve, a proportional reversing valve, a proportional overflow valve and a oil supplement valve which are respectively installed on the valve body, an oil return channel is arranged between the outlet of the proportional overflow valve and the valve group oil return port; the inlet of the electromagnetic flow control valve is connected to the valve group oil inlet, a first oil supply channel and a second oil supply channel are respectively arranged between the first outlet of the electromagnetic flow control valve, the second outlet of the electromagnetic flow control valve and the valve body oil inlet of the electric control reversing valve module, the electromagnetic flow regulating valve is connected in series with the second oil supply channel, and the valve body oil return port of the electric control reversing valve module is connected to the oil return channel; a lifting oil port connecting channel is arranged between the first working oil port of the electric control reversing valve module and the lifting oil port, a lowering oil port connecting channel is arranged between the second working oil port of the electric control reversing valve module and the lowering oil port, and the proportional reversing valve is connected in series with the lifting oil port connecting channel; a falling overflow channel is arranged between the lowering oil port connecting channel and the inlet of the proportional overflow valve, an oil supplement channel is arranged between the lowering oil port connecting channel or the falling overflow channel and the oil return channel, and the oil supplement valve is connected in series with the oil supplement channel.

[0005] As an improvement, a pump oil passage between the valve group oil inlet and the inlet of the electromagnetic flow control valve is provided with a valve group overflow passage, and a first safety valve is connected in series to the valve group overflow passage; a lift overflow passage is provided between the lift oil inlet and the oil return passage, and a second safety valve is connected in series to the lift overflow passage.

[0006] As an improvement, the electrically controlled reversing valve module comprises a hydraulic reversing valve, a lift electromagnetic reversing valve and a drop electromagnetic reversing valve; the working oil port of the lift electromagnetic reversing valve is connected to the regulating oil port on the lift oil passage side of the hydraulic reversing valve, and the working oil port of the drop electromagnetic reversing valve is connected to the regulating oil port on the drop oil passage side of the hydraulic reversing valve; the inlet of the lift electromagnetic reversing valve and the inlet of the drop electromagnetic reversing valve are respectively connected to the pump oil passage; the oil return port of the lift electromagnetic reversing valve and the oil return port of the drop electromagnetic reversing valve are respectively connected to the oil return passage.

[0007] As an improvement, a damping plug is connected in series to the regulating oil passage between the working oil port of the lift electromagnetic reversing valve and the regulating oil port on the lift oil passage side of the hydraulic reversing valve, and to the regulating oil passage between the working oil port of the drop electromagnetic reversing valve and the regulating oil port on the drop oil passage side of the hydraulic reversing valve.

[0008] As an improvement, the valve body is provided with a reversing control passage connected to the valve group overflow passage between the pump oil passage and the first safety valve, and the inlet of the lift electromagnetic reversing valve and the inlet of the drop electromagnetic reversing valve are respectively connected to the reversing control passage.

[0009] As an improvement, the first safety valve and the second safety valve are overflow valves.

[0010] As an improvement, the valve body is further provided with a bypass oil inlet connected to the third oil supply port of the electromagnetic flow control valve.

[0011] As an improvement, the valve body is further provided with a first pressure measuring port, a second pressure measuring port and a third pressure measuring port, the first pressure measuring port is in communication with the inlet of the electromagnetic flow control valve, the second pressure measuring port is in communication with the lift oil inlet, and the third pressure measuring port is in communication with the inlet of the proportional overflow valve, and a pressure measuring component is installed in each of the first pressure measuring port, the second pressure measuring port and the third pressure measuring port.

[0012] The application also discloses a tractor lifting system control method.

[0013] The lifting control of the agricultural implement in S10 is as follows:

[0014] The electronic control unit controls the electromagnetic flow control valve to open and the electrically controlled reversing valve module to open, and makes the lifting oil path side of the electrically controlled reversing valve module electrified. After the lifting oil path side of the electrically controlled reversing valve module is electrified, the first working oil port of the electrically controlled reversing valve module is communicated with the valve body inlet port of the electrically controlled reversing valve module, and the second working oil port of the electrically controlled reversing valve module is communicated with the valve body return oil port of the electrically controlled reversing valve module. The hydraulic oil pumped by the valve group inlet port of the oil pump flows into the electromagnetic flow control valve, the hydraulic oil flowing out of the first outlet of the electromagnetic flow control valve flows to the valve body inlet port of the electrically controlled reversing valve module through the first oil supply channel, and the hydraulic oil flowing out of the first working oil port of the electrically controlled reversing valve module flows to the lifting oil port through the lifting oil port connecting channel and the proportional reversing valve, and then flows to the rodless cavity of the lifting oil cylinder through the lifting oil port, pushes the piston rod of the lifting oil cylinder to extend, drives the agricultural implement to lift, and the piston of the lifting oil cylinder pushes the hydraulic oil in the rod cavity of the lifting oil cylinder to flow out, and the hydraulic oil flowing out of the rod cavity of the lifting oil cylinder flows through the lowering oil port, the second working oil port of the electrically controlled reversing valve module and the valve body return oil port of the electrically controlled reversing valve module, and then flows into the return oil channel.

[0015] When the lifting speed is increased, the electronic control unit controls the electromagnetic flow regulating valve to open, the proportional overflow valve to open, the second oil supply channel to open, and the hydraulic oil flow of the valve body oil inlet of the electronic control reversing valve module to increase, so that the hydraulic oil flow into the rodless cavity of the lifting cylinder increases, and the lifting speed of the implement is increased. Correspondingly, the hydraulic oil flow from the rod cavity of the lifting cylinder increases, and the hydraulic oil from the inside of the rod cavity of the lifting cylinder flows into the descending oil inlet connection channel through the descending oil inlet. Part of the hydraulic oil in the descending oil inlet connection channel flows through the second working oil inlet of the electronic control reversing valve module, the valve body return oil inlet of the electronic control reversing valve module, and then flows into the return oil channel. Another part of the hydraulic oil in the descending oil inlet connection channel flows through the falling overflow channel and the proportional overflow valve, and then flows into the return oil channel.

[0016] The implement descending control is as follows:

[0017] The electronic control unit controls the electromagnetic flow regulating valve to close, controls the proportional reversing valve to open so that the proportional reversing valve switches to the reverse flow state, controls the electronic control reversing valve module to open, and makes the descending oil path side of the electronic control reversing valve module electrified. The first working oil inlet of the electronic control reversing valve module is in communication with the valve body return oil inlet of the electronic control reversing valve module, and the second working oil inlet of the electronic control reversing valve module is in communication with the valve body oil inlet of the electronic control reversing valve module.

[0018] When the electronic control unit controls the electromagnetic flow control valve to close, the electromagnetic flow control valve does not supply oil, the weight of the implement presses the piston rod of the lifting cylinder to retract, and the weight of the implement is lowered. The electronic control unit controls the opening degree of the proportional reversing valve to adjust the outflow speed of the hydraulic oil in the rodless cavity of the lifting cylinder, and adjusts the descending speed of the weight of the implement. The piston rod of the lifting cylinder retracts, the volume of the rod cavity of the lifting cylinder increases, the pressure in the rod cavity of the lifting cylinder decreases, and the hydraulic oil is sucked back through the oil supplement channel to supplement the oil in the rod cavity of the lifting cylinder, so as to balance the pressure difference between the rodless cavity of the lifting cylinder and the rod cavity of the lifting cylinder.

[0019] When the electronic control unit controls the electromagnetic flow control valve to open, the electromagnetic flow control valve supplies oil to the valve body oil inlet of the electronic control reversing valve module. The hydraulic oil flowing out of the first outlet of the electromagnetic flow control valve flows to the rod cavity of the lifting cylinder through the first oil supply channel, the valve body oil inlet of the electronic control reversing valve module, the second working oil inlet of the electronic control reversing valve module, the descending oil inlet connection channel, and the descending oil inlet, increases the pressure in the rod cavity of the lifting cylinder, and forcibly pushes the piston rod of the lifting cylinder to fall, so as to realize the forced descending of the implement.

[0020] When the farm implement is lowered, the piston rod of the lifting oil cylinder is retracted, the hydraulic oil inside the rodless chamber of the lifting oil cylinder is pressed out, the hydraulic oil flowing out of the rodless chamber of the lifting oil cylinder flows through the lifting oil port, the lifting oil port connecting channel, the proportional reversing valve, the first working oil port of the electric control reversing valve module, the valve body return oil port of the electric control reversing valve module, and then flows into the return oil channel;

[0021] The down pressure control when the farm implement is working is as follows:

[0022] After the farm implement is lowered, the electric control unit controls the electromagnetic flow control valve to be in an open state, controls the electric control reversing valve module to be in an open state and makes the lowering oil path side of the electric control reversing valve module electrified, controls the proportional overflow valve to be in an open state, the electromagnetic flow control valve supplies oil to the valve body oil inlet of the electric control reversing valve module, the hydraulic oil flowing out of the first outlet of the electromagnetic flow control valve flows to the rod chamber of the lifting oil cylinder through the first oil supply channel, the valve body oil inlet of the electric control reversing valve module, the second working oil port of the electric control reversing valve module, the lowering oil port connecting channel, and the lowering oil port, the pressure on the piston of the lifting oil cylinder is exerted by the hydraulic oil flowing into the rod chamber of the lifting oil cylinder, so as to exert the down pressure on the farm implement, the flow of the down fall overflow channel is adjusted by the proportional overflow valve, the pressure inside the rod chamber of the lifting oil cylinder is adjusted, and thus the down pressure exerted on the farm implement is adjusted.

[0023] The floating control of the farm implement is as follows:

[0024] The electric control unit controls the proportional overflow valve to be closed, controls the electric control reversing valve module to be closed, the down fall overflow channel is closed, the lifting oil path side of the electric control reversing valve module and the lowering oil path side of the electric control reversing valve module are disconnected, the hydraulic oil between the first working oil port of the electric control reversing valve module, the lifting oil port connecting channel, the lifting oil port and the rodless chamber of the lifting oil cylinder does not flow, the hydraulic oil between the second working oil port of the electric control reversing valve module, the lowering oil port connecting channel, the lowering oil port and the rod chamber of the lifting oil cylinder does not flow, the pressure inside the rodless chamber of the lifting oil cylinder is in a balanced state with the pressure inside the rod chamber of the lifting oil cylinder, and the farm implement is in a floating state.

[0025] As an improvement, in the down pressure control when the farm implement is working, the control switch of the electromagnetic flow control valve is opened, the second oil supply channel between the second outlet of the electromagnetic flow control valve and the valve body oil inlet of the electric control reversing valve module is opened, and the flow of the hydraulic oil flowing into the rod chamber of the lifting oil cylinder is increased.

[0026] The beneficial effects achieved by the present invention after adopting the above technical solution are as follows:

[0027] The tractor-mounted electrically controlled lifting valve assembly of the present invention includes a valve body, on which are provided a valve assembly inlet, a lifting port, a lowering port, and a valve assembly return port. It also includes an electromagnetic flow control valve, an electrically controlled directional valve module, an electromagnetic flow regulating valve, a proportional directional valve, a proportional relief valve, and a replenishing valve, all respectively installed on the valve body. A return oil passage is provided between the outlet of the proportional relief valve and the valve assembly return port. The inlet of the electromagnetic flow control valve is connected to the valve assembly inlet. A first oil supply passage and a second oil supply passage are respectively provided between the first outlet of the electromagnetic flow control valve, the second outlet of the electromagnetic flow control valve, and the valve body inlet of the electrically controlled directional valve module. The oil supply channel includes an electromagnetic flow regulating valve connected in series to the second oil supply channel, and the valve body return port of the electrically controlled directional valve module connected to the return oil channel. A lifting port connection channel is provided between the first working port and the lifting port of the electrically controlled directional valve module, and a lowering port connection channel is provided between the second working port and the lowering port of the electrically controlled directional valve module. A proportional directional valve is connected in series to the lifting port connection channel. A falling overflow channel is provided between the lowering port connection channel and the inlet of the proportional overflow valve. A replenishment channel is provided between the lowering port connection channel or the falling overflow channel and the return oil channel, and a replenishment valve is connected in series to the replenishment channel.

[0028] The present invention relates to a tractor lifting system control method, based on the above-mentioned tractor electronically controlled lifting valve group, including implement lifting control, implement lowering control, implement downward pressure control during operation, and implement floating control.

[0029] The present invention provides a tractor-mounted electronic lift valve assembly and a lift system control method that solves the problem that existing tractor-mounted electronic lift valve assemblies cannot adjust the flow rate according to usage requirements. Users can adjust the flow rate of the tractor-mounted electronic lift valve assembly to regulate the speed of the implement's lifting, descent, forced descent actions, and downward pressure during implementation, thereby effectively improving work efficiency. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the structure of the electronically controlled lifting valve assembly for tractors according to an embodiment of the present invention;

[0031] Wherein, 10, valve body; 11, valve group oil inlet; 12, lifting oil port; 13, falling oil port; 14, valve group oil return port; 15, bypass oil port; 16, first pressure measuring port; 17, second pressure measuring port; 18, third pressure measuring port; 191, oil return channel; 192, falling overflow channel; 193, lifting overflow channel; 194, valve group overflow channel; 195, reversing control channel; 20, electromagnetic flow control valve; 21, first oil supply channel; 22, second oil supply channel; 31, hydraulic reversing valve; 311, valve body oil inlet; 312, valve body oil return port; 313, first working oil port; 314, second working oil port; 35, lifting electromagnetic reversing valve; 36, falling electromagnetic reversing valve; 40, electromagnetic flow regulating valve; 50, proportional reversing valve; 61, proportional overflow valve; 62, first safety valve; 63, second safety valve; 70, oil supplement valve; 80, lifting oil cylinder; 81, rod cavity; 82, rodless cavity; 90, oil pump. DETAILED DESCRIPTION

[0032] The present application is further described below in conjunction with the accompanying drawings and embodiments, preferred embodiments of the present application are shown in the drawings, the drawings serve to supplement the description in the text part of the description, so that people can intuitively and visually understand each technical feature and the overall technical scheme of the present application, but it cannot be understood as a limitation on the protection scope of the present application.

[0033] Figure 1 The structure schematic diagram of the electric control lifting valve group for tractor of the embodiment of the present application is shown, in order to facilitate the description, only the part related to the embodiment of the present application is given in the drawing.

[0034] It should be noted that if the present application involves directional indications, such as up, down, front, back, left, right, etc., the directional indications are only used to explain the relative position relationship between the components in a certain posture, if the certain posture changes, the directional indications also change accordingly; If the present application involves the description of "first", "second" and the like, the description of "first", "second" and the like is only for description purpose, and cannot be understood as indicating or implying the relative importance of the indicated technical features or implicitly indicating the number of the indicated technical features; Unless otherwise specified, the words such as "setting", "installing", "connecting" should be understood in a broad sense, and the skilled in the art can reasonably determine the specific meaning of the above words in the present application according to the specific content of the technical scheme.

[0035] As Figure 1As shown, the embodiment of the application discloses an electric control poppet valve group for tractor, which comprises a valve body 10, a valve group oil inlet 11, a lifting oil inlet 12, a falling oil inlet 13 and a valve group oil return port 14 are arranged on the valve body 10, and further comprises an electromagnetic flow control valve 20, an electric control reversing valve module, an electromagnetic flow regulating valve 40, a proportional reversing valve 50, a proportional overflow valve 61 and an oil supplement valve 70 which are respectively installed on the valve body 10, an oil return channel 191 is arranged between the outlet of the proportional overflow valve 61 and the valve group oil return port 14; the oil inlet of the electromagnetic flow control valve 20 is connected to the valve group oil inlet 11, a first oil supply channel 21 and a second oil supply channel 22 are respectively arranged between the first outlet of the electromagnetic flow control valve 20, the second outlet of the electromagnetic flow control valve 20 and the valve body oil inlet 311 of the electric control reversing valve module, the electromagnetic flow regulating valve 40 is connected in series to the second oil supply channel 22, and the valve body oil return port 312 of the electric control reversing valve module is connected to the oil return channel 191; a lifting oil inlet connecting channel is arranged between the first working oil inlet 313 of the electric control reversing valve module and the lifting oil inlet 12, a falling oil inlet connecting channel is arranged between the second working oil inlet 314 of the electric control reversing valve module and the falling oil inlet 13, and the proportional reversing valve 50 is connected in series to the lifting oil inlet connecting channel; a falling overflow channel 192 is arranged between the falling oil inlet connecting channel and the oil inlet of the proportional overflow valve 61, an oil supplement channel is arranged between the falling oil inlet connecting channel or the falling overflow channel 192 and the oil return channel 191, and the oil supplement valve 70 is connected in series to the oil supplement channel.

[0036] During installation, the oil pump 90 is connected to the valve group oil inlet 11, the lifting oil inlet 12 is connected to the rodless cavity 82 of the lifting cylinder 80, the falling oil inlet 13 is connected to the rod cavity 81 of the lifting cylinder 80, and the valve group oil return port 14 is connected to the oil tank; during work, the oil pump 90 pumps the hydraulic oil in the oil tank or other oil supply pipes into the valve group oil inlet 11 at a certain pressure.

[0037] In order to facilitate understanding, the lifting control process of the farm implement is described as follows:

[0038] When the implement is lifted, the oil pump 90 pumps hydraulic oil into the valve group inlet oil port 11 and then to the electromagnetic flow control valve 20. When the electromagnetic flow control valve 20 is powered, the first working oil port 313 of the electric control reversing valve module is in communication with the valve body inlet oil port 311 of the electric control reversing valve module, the second working oil port 314 of the electric control reversing valve module is in communication with the valve body return oil port 312 of the electric control reversing valve module, and the hydraulic oil flowing out of the first outlet of the electromagnetic flow control valve 20 flows to the valve body inlet oil port 311 of the electric control reversing valve module through the first oil supply channel 21. The lifting oil path side of the electric control reversing valve module is powered, the hydraulic oil flowing out of the first working oil port 313 of the electric control reversing valve module flows to the lifting oil port 12 through the proportional reversing valve 50, and then flows to the rodless cavity 82 of the lifting oil cylinder 80 through the lifting oil port 12, pushing the piston rod of the lifting oil cylinder 80 to extend and drive the implement to lift. At the same time, the piston of the lifting oil cylinder 80 pushes the hydraulic oil inside the rod cavity 81 of the lifting oil cylinder 80 to flow out, and the hydraulic oil flowing out of the rod cavity 81 of the lifting oil cylinder 80 flows through the lowering oil port 13, the second working oil port 314 of the electric control reversing valve module, and the valve body return oil port 312 of the electric control reversing valve module, and then flows into the return oil channel 191, and then flows into the oil tank through the valve group return oil port 14.

[0039] When the lifting speed needs to be increased, the electromagnetic flow regulating valve 40 is powered, and the proportional overflow valve 61 is powered. The second oil supply channel 22 between the second outlet of the electromagnetic flow control valve 20 and the valve body inlet oil port 311 of the electric control reversing valve module is opened, which can increase the hydraulic oil flow of the valve body inlet oil port 311 of the electric control reversing valve module, thereby increasing the hydraulic oil flow flowing into the rodless cavity 82 of the lifting oil cylinder 80, and increasing the lifting speed of the implement. Correspondingly, the hydraulic oil flow flowing out of the rod cavity 81 of the lifting oil cylinder 80 increases, and the hydraulic oil flowing out of the rod cavity 81 of the lifting oil cylinder 80 flows into the lowering oil port connection channel through the lowering oil port 13. Part of the hydraulic oil in the lowering oil port connection channel flows through the second working oil port 314 of the electric control reversing valve module, the valve body return oil port 312 of the electric control reversing valve module, and then flows into the return oil channel 191 and flows into the oil tank through the valve group return oil port 14. Another part of the hydraulic oil in the lowering oil port connection channel flows through the falling overflow channel 192 and the proportional overflow valve 61, and then flows into the return oil channel 191 and flows into the oil tank through the valve group return oil port 14, which can smoothly flow out the hydraulic oil inside the rod cavity 81 of the lifting oil cylinder 80, and avoid the hydraulic oil inside the rod cavity 81 of the lifting oil port 12 from hindering the piston rod of the lifting oil cylinder 80 from extending. During the lifting of the implement, the opening degree of the electromagnetic flow control valve 20 can be adjusted to adjust the hydraulic oil flow in the second oil supply channel 22, thereby adjusting the hydraulic oil flow flowing into the rodless cavity 82 of the lifting oil cylinder 80, and adjusting the lifting speed.

[0040] When the farm implement is descending, the electromagnetic flow control valve 40 is powered off, the electrically controlled reversing valve module is powered on at the descending oil path side, the proportional reversing valve 50, the first working oil path 313 of the electrically controlled reversing valve module is communicated with the valve body return oil path 312 of the electrically controlled reversing valve module, and the second working oil path 314 of the electrically controlled reversing valve module is communicated with the valve body inlet oil path 311 of the electrically controlled reversing valve module;

[0041] When the electromagnetic flow control valve 20 does not supply oil to the valve body inlet oil path 311 of the electrically controlled reversing valve module, the weight of the farm implement can retract the piston rod of the lifting oil cylinder 80, so as to realize the self-weight descent of the farm implement. When the piston rod of the lifting oil cylinder 80 is retracted, the hydraulic oil in the rodless cavity 82 of the lifting oil cylinder 80 is pressed out. Since the proportional reversing valve 50 can flow in the reverse direction after being powered on, the hydraulic oil flowing out of the rodless cavity 82 of the lifting oil cylinder 80 flows through the lifting oil port 12, the lifting oil port connecting channel, the first working oil path 313 of the electrically controlled reversing valve module, the valve body return oil path 312 of the electrically controlled reversing valve module, and then flows into the return oil channel 191, and flows into the oil tank through the valve group return oil port 14. After the piston rod of the lifting oil cylinder 80 is retracted, the volume of the rod cavity 81 of the lifting oil cylinder 80 increases, and the pressure in the rod cavity 81 of the lifting oil cylinder 80 decreases. Since the oil supplement channel is arranged between the descending oil port connecting channel or the falling overflow channel 192 and the return oil channel 191, and the oil supplement valve 70 is connected in series on the oil supplement channel, when the pressure in the rod cavity 81 of the lifting oil cylinder 80 decreases, the hydraulic oil in the return oil channel 191 can be sucked into the rod cavity 81 of the lifting oil cylinder 80 through the oil supplement channel, so as to balance the pressure difference between the rod cavity 81 of the lifting oil cylinder 80 and the rodless cavity 82 of the lifting oil cylinder 80, and facilitate the stable self-weight descent of the farm implement. At the same time, by adjusting the opening size of the proportional reversing valve 50, the flow rate of the hydraulic oil flowing out of the rodless cavity 82 of the lifting oil cylinder 80 can be adjusted, so as to adjust the speed of the self-weight descent of the farm implement.

[0042] When the electromagnetic flow control valve 20 supplies oil to the valve body inlet oil path 311 of the electrically controlled reversing valve module, the hydraulic oil flows into the electrically controlled reversing valve module from the valve body inlet oil path 311 of the electrically controlled reversing valve module, flows out from the second working oil path 314 of the electrically controlled reversing valve module, and then flows into the rod cavity 81 of the lifting oil cylinder 80 after flowing through the descending oil port connecting channel and the descending oil port 13. By increasing the pressure in the rod cavity 81 of the lifting oil cylinder 80, the piston rod of the lifting oil cylinder 80 is forced to fall, so as to realize the forced descent of the farm implement.

[0043] When the farm implement is working, the pressure needs to be applied to the farm implement for ditching, rotary tillage, plowing and the like, and the pressure applied to the different farm implements is also different, at this time, the lowering oil way side of the electric control reversing valve module is powered, the proportional overflow valve 61 is powered, the pressure can be applied to the piston of the lifting oil cylinder 80 through the hydraulic oil flowing into the rod cavity 81 of the lifting oil cylinder 80, so that the pressure can be applied to the farm implement, the flow of the falling overflow passage 192 is adjusted through the proportional overflow valve 61, the pressure inside the rod cavity 81 of the lifting oil cylinder 80 is adjusted, so that the pressure applied to the farm implement is adjusted, of course, the electromagnetic flow regulating valve 40 can be powered, the second oil supply passage 22 between the second outlet of the electromagnetic flow control valve 20 and the valve body oil inlet 311 of the electric control reversing valve module is opened, the hydraulic oil flow flowing into the rod cavity 81 of the lifting oil cylinder 80 is increased, the pressure inside the rod cavity 81 of the lifting oil cylinder 80 is increased, and greater pressure can be applied to the farm implement.

[0044] When the farm implement is floating, the electric control reversing valve module is powered off, the valve core of the electric control reversing valve module is located at the middle position, the lifting oil way side of the electric control reversing valve module is disconnected, the lowering oil way side of the electric control reversing valve module is disconnected, the hydraulic oil between the first working oil port 313, the lifting oil port connecting passage, the lifting oil port 12 and the rodless cavity 82 of the lifting oil cylinder 80 is not flowed, the hydraulic oil between the second working oil port 314, the lowering oil port connecting passage, the lowering oil port 13 and the rod cavity 81 of the lifting oil cylinder 80 is not flowed, and the farm implement is in the floating state.

[0045] The tractor electric control lifting valve group of the embodiment of the application solves the problem that the existing tractor electric control lifting valve group cannot adjust the flow according to the use demand, the user can adjust the flow of the tractor electric control lifting valve group according to the use demand to realize the adjustment of the lifting, self-weight lowering, forced lowering speed of the farm implement and the pressure of the farm implement when working, and the work efficiency is effectively improved.

[0046] In the embodiment of the application, the valve group overflow passage 194 is arranged between the pump oil passage and the oil return passage 191 between the valve group oil inlet 11 and the oil inlet of the electromagnetic flow control valve 20, the first safety valve 62 is connected in series on the valve group overflow passage 194, when the pressure of the hydraulic oil pumped into the valve group oil inlet 11 by the oil pump 90 is too large, part of the hydraulic oil will flow into the oil return passage 191 through the valve group overflow passage 194 and the first safety valve 62, and the pressure is reduced; the lifting overflow passage 193 is arranged between the lifting oil port 12 and the oil return passage 191, the second safety valve 63 is connected in series on the lifting overflow passage 193, when the pressure of the hydraulic oil of the lifting oil port connecting passage is too large, part of the hydraulic oil will flow into the oil return passage 191 through the lifting overflow passage 193 and the second safety valve 63, and the pressure is reduced.

[0047] Generally, the first safety valve 62 and the second safety valve 63 are overflow valves.

[0048] In the embodiment of the application, the electrically-controlled reversing valve module is a combined structure, comprising the hydraulic reversing valve 31, the lifting electromagnetic reversing valve 35 and the lowering electromagnetic reversing valve 36; the working oil port of the lifting electromagnetic reversing valve 35 is connected to the adjusting oil port on the lifting oil path side of the hydraulic reversing valve 31, and the working oil port of the lowering electromagnetic reversing valve 36 is connected to the adjusting oil port on the lowering oil path side of the hydraulic reversing valve 31; the inlets of the lifting electromagnetic reversing valve 35 and the lowering electromagnetic reversing valve 36 are respectively connected to the pump oil passage between the valve group oil inlet 11 and the inlet of the electromagnetic flow control valve 20; the return oil ports of the lifting electromagnetic reversing valve 35 and the lowering electromagnetic reversing valve 36 are respectively connected to the return oil passage 191. When the implement is lifted, the lifting electromagnetic reversing valve 35 is powered and the lowering electromagnetic reversing valve 36 is powered off; the lifting electromagnetic reversing valve 35 supplies oil to the adjusting oil port on the lifting oil path side of the hydraulic reversing valve 31, pushes the valve core of the hydraulic reversing valve 31 to move, and makes the first working oil port 313 of the hydraulic reversing valve 31 communicate with the valve body oil inlet 311 of the hydraulic reversing valve 31 and the second working oil port 314 of the hydraulic reversing valve 31 communicate with the valve body return oil port 312 of the hydraulic reversing valve 31; when the valve core of the hydraulic reversing valve 31 moves, the hydraulic oil flowing out of the adjusting oil port on the lowering oil path side of the hydraulic reversing valve 31 flows into the return oil passage 191 through the lowering electromagnetic reversing valve 36; when the implement is lowered, the lifting electromagnetic reversing valve 35 is powered off and the lowering electromagnetic reversing valve 36 is powered; the lowering electromagnetic reversing valve 36 supplies oil to the adjusting oil port on the lowering oil path side of the hydraulic reversing valve 31, pushes the valve core of the hydraulic reversing valve 31 to reversely move, and makes the first working oil port 313 of the hydraulic reversing valve 31 communicate with the valve body return oil port 312 of the hydraulic reversing valve 31 and the second working oil port 314 of the hydraulic reversing valve 31 communicate with the valve body oil inlet 311 of the hydraulic reversing valve 31; when the valve core of the hydraulic reversing valve 31 reversely moves, the hydraulic oil flowing out of the adjusting oil port on the lifting oil path side of the hydraulic reversing valve 31 flows into the return oil passage 191 through the lifting electromagnetic reversing valve 35. The reversing of the hydraulic reversing valve 31 is adjusted by the lifting electromagnetic reversing valve 35 and the lowering electromagnetic reversing valve 36, so that the adjusting action is more stable, thereby improving the service life.

[0049] Specifically, the valve body 10 is internally provided with a reversing control passage 195 connected to the valve group overflow passage 194 between the pump oil passage and the first safety valve 62; the inlets of the lifting electromagnetic reversing valve 35 and the lowering electromagnetic reversing valve 36 are respectively connected to the reversing control passage 195.

[0050] Further, the adjusting oil paths between the working oil ports of the lifting electromagnetic reversing valve 35 and the adjusting oil port on the lifting oil path side of the hydraulic reversing valve 31 and between the working oil ports of the lowering electromagnetic reversing valve 36 and the adjusting oil port on the lowering oil path side of the hydraulic reversing valve 31 are respectively connected with damping plugs.

[0051] In some other embodiments, the electrically-controlled reversing valve module is an electromagnetic reversing valve.

[0052] In the embodiment of the present application, the valve body 10 is further provided with a bypass oil port 15, which is connected to the third oil supply port of the electromagnetic flow control valve 20.

[0053] When the implement is used, the first outlet of the electromagnetic flow control valve 20 and the second outlet of the electromagnetic flow control valve 20 are supplied with oil, and the third outlet of the electromagnetic flow control valve 20 is closed; when the implement is not used, the first outlet of the electromagnetic flow control valve 20 and the second outlet of the electromagnetic flow control valve 20 are closed, and the third outlet of the electromagnetic flow control valve 20 is opened, which can be used to supply oil to other parts of the tractor.

[0054] In the embodiment of the present application, the valve body 10 is further provided with a first pressure measuring port 16, a second pressure measuring port 17 and a third pressure measuring port 18, the first pressure measuring port 16 is in communication with the inlet of the electromagnetic flow control valve 20, the second pressure measuring port 17 is in communication with the lifting oil port 12, and the third pressure measuring port 18 is in communication with the inlet of the proportional overflow valve 61, and a pressure measuring component is installed in each of the first pressure measuring port 16, the second pressure measuring port 17 and the third pressure measuring port 18, so that the pressure measured by the pressure measuring component can be used to determine whether each valve in the electrically-controlled lifting valve group for tractors is working normally.

[0055] Generally, the pressure measuring component is a pressure sensor, a liquid pressure gauge or the like.

[0056] The embodiment of the present application further discloses a tractor lifting system control method, the tractor lifting system comprising the electrically-controlled lifting valve group for tractors, an oil pump 90 connected to the oil inlet 11 of the valve group, at least one lifting oil cylinder and an electric control unit, the lifting oil port 12 being connected to the rodless cavity 82 of the at least one lifting oil cylinder 80, the lowering oil port 13 being connected to the rod cavity 81 of the at least one lifting oil cylinder 80, the valve group oil return port 14 being connected to an oil tank, the electromagnetic flow control valve 20, the electrically-controlled reversing valve module, the electromagnetic flow regulating valve 40, the proportional reversing valve 50 and the proportional overflow valve 61 being electrically connected to the electric control unit, and the piston rod of the at least one lifting oil cylinder 80 being connected to an implement.

[0057] The tractor lifting system control method comprises the following steps.

[0058] S10, the lifting control of the implement is as follows:

[0059] The electric control unit controls the electromagnetic flow control valve 20 to open, the electric control reversing valve module to open, and the electric control reversing valve module to be electrified on the lifting oil way side. After the electric control reversing valve module is electrified on the lifting oil way side, the first working oil port 313 of the electric control reversing valve module is communicated with the valve body inlet oil port 311 of the electric control reversing valve module, and the second working oil port 314 of the electric control reversing valve module is communicated with the valve body return oil port 312 of the electric control reversing valve module. The oil pump 90 is pumped by the hydraulic oil flowing into the electromagnetic flow control valve 20 from the valve group inlet oil port 11. The hydraulic oil flowing out of the first outlet of the electromagnetic flow control valve 20 flows to the valve body inlet oil port 311 of the electric control reversing valve module through the first oil supply channel 21. After flowing out of the first working oil port 313 of the electric control reversing valve module, the hydraulic oil flows to the lifting oil port 12 through the proportional reversing valve 50, and then flows to the rodless cavity 82 of the lifting oil cylinder 80 through the lifting oil port 12. The hydraulic oil in the rodless cavity 82 of the lifting oil cylinder 80 is pushed out by the piston rod of the lifting oil cylinder 80, and the lifting oil cylinder 80 is driven to extend. The hydraulic oil in the rod cavity 81 of the lifting oil cylinder 80 is pushed out by the piston of the lifting oil cylinder 80. The hydraulic oil flowing out of the rod cavity 81 of the lifting oil cylinder 80 flows through the falling oil port 13, the second working oil port 314 of the electric control reversing valve module, and the valve body return oil port 312 of the electric control reversing valve module, and then flows into the return oil channel 191. The hydraulic oil flows into the oil tank through the valve group return oil port 14.

[0060] When the lifting speed is increased, the electric control unit controls the electromagnetic flow control valve 40 and the proportional overflow valve 61 to open, the second oil supply channel 22 between the second outlet of the electromagnetic flow control valve 20 and the valve body inlet oil port 311 of the electric control reversing valve module is opened, the hydraulic oil flow of the valve body inlet oil port 311 of the electric control reversing valve module is increased, the hydraulic oil flow flowing into the rodless cavity 82 of the lifting oil cylinder 80 is increased, and the lifting speed of the implement is increased. Correspondingly, the hydraulic oil flow flowing out of the rod cavity 81 of the lifting oil cylinder 80 is increased. The hydraulic oil flowing out of the rod cavity 81 of the lifting oil cylinder 80 flows into the falling oil port connecting channel through the falling oil port 13. Part of the hydraulic oil in the falling oil port connecting channel flows through the second working oil port 314 of the electric control reversing valve module and the valve body return oil port 312 of the electric control reversing valve module, and then flows into the return oil channel 191 and flows into the oil tank through the valve group return oil port 14. Another part of the hydraulic oil in the falling oil port connecting channel flows through the falling overflow channel 192 and the proportional overflow valve 61, and then flows into the return oil channel 191 and flows into the oil tank through the valve group return oil port 14.

[0061] After the proportional overflow valve 61 is electrified and opened, the falling overflow channel 192 is opened, the hydraulic oil in the rod cavity 81 of the lifting oil cylinder 80 can flow out smoothly, and the hydraulic oil in the rod cavity 81 of the lifting oil port 12 is prevented from hindering the piston rod of the lifting oil cylinder 80 from extending. During the lifting of the implement, the opening degree of the electromagnetic flow control valve 20 can be adjusted to adjust the hydraulic oil flow in the second oil supply channel 22, so as to adjust the hydraulic oil flow flowing into the rodless cavity 82 of the lifting oil cylinder 80, thereby realizing the adjustment of the lifting speed.

[0062] The lowering control of the farm implement is as follows:

[0063] The electric control unit controls the electromagnetic flow control valve 40 to close, controls the proportional reversing valve 50 to open, and makes the proportional reversing valve 50 switch to the reverse flow state. The electric control unit controls the electric control reversing valve module to open and makes the lowering oil way side of the electric control reversing valve module electrified. The first working oil port 313 of the electric control reversing valve module is communicated with the valve body return oil port 312 of the electric control reversing valve module, and the second working oil port 314 of the electric control reversing valve module is communicated with the valve body inlet oil port 311 of the electric control reversing valve module.

[0064] When the electric control unit controls the electromagnetic flow control valve 20 to close, the electromagnetic flow control valve 20 does not supply oil, the self-weight of the farm implement drives the piston rod of the lifting cylinder 80 to retract, and the self-weight lowering of the farm implement is realized. The electric control unit controls the opening degree of the adjusting proportional reversing valve 50 to adjust the outflow speed of the hydraulic oil in the rodless cavity 82 of the lifting cylinder 80, and the self-weight lowering speed of the farm implement is adjusted. The piston rod of the lifting cylinder 80 retracts, the volume of the rod cavity 81 of the lifting cylinder 80 increases, the pressure in the rod cavity 81 of the lifting cylinder 80 decreases, the hydraulic oil is sucked back through the oil supplement channel connected between the lowering oil port connecting channel or the falling overflow channel 192 and the return oil channel 191 to supplement the oil in the rod cavity 81 of the lifting cylinder 80, so as to balance the pressure difference between the rod cavity 81 of the lifting cylinder 80 and the rodless cavity 82 of the lifting cylinder 80, and facilitate the stable self-weight lowering of the farm implement.

[0065] When the electric control unit controls the electromagnetic flow control valve 20 to open, the electromagnetic flow control valve 20 supplies oil to the valve body inlet oil port 311 of the electric control reversing valve module. The hydraulic oil flowing out of the first outlet of the electromagnetic flow control valve 20 flows to the rod cavity 81 of the lifting cylinder 80 through the first oil supply channel 21, the valve body inlet oil port 311 of the electric control reversing valve module, the second working oil port 314 of the electric control reversing valve module, the lowering oil port connecting channel, and the lowering oil port 13, increases the pressure in the rod cavity 81 of the lifting cylinder 80, and forcibly drives the piston rod of the lifting cylinder 80 to fall, so as to realize the forced lowering of the farm implement.

[0066] The self-weight of the farm implement drives the piston rod of the lifting cylinder 80 to retract, and the hydraulic oil in the rodless cavity 82 of the lifting cylinder 80 is pressed out. The hydraulic oil flowing out of the rodless cavity 82 of the lifting cylinder 80 flows into the return oil channel 191 through the lifting oil port 12, the lifting oil port connecting channel, the proportional reversing valve 50, the first working oil port 313 of the electric control reversing valve module, and the valve body return oil port 312 of the electric control reversing valve module, and then flows into the oil tank through the valve group return oil port 14.

[0067] The lowering pressure control of the farm implement during work is as follows:

[0068] In the furrow, rotary plough, plough, etc., need to exert pressure on the farm tools, for different farm tools need to exert pressure will also be different;

[0069] After the farm tools fall, the electric control unit controls the electromagnetic flow control valve 20 to be in the open state, controls the electric control reversing valve module to be in the open state, and makes the descending oil path side of the electric control reversing valve module electrified, controls the proportional overflow valve 61 to be in the open state, the electromagnetic flow control valve 20 supplies oil to the valve body oil inlet 311 of the electric control reversing valve module, the hydraulic oil flowing out of the first outlet of the electromagnetic flow control valve 20 flows to the rod cavity 81 of the lifting oil cylinder 80 through the first oil supply channel 21, the valve body oil inlet 311 of the electric control reversing valve module, the second working oil port 314 of the electric control reversing valve module, the descending oil port connecting channel, and the descending oil port 13, and the pressure on the piston of the lifting oil cylinder 80 is exerted by the hydraulic oil flowing into the rod cavity 81 of the lifting oil cylinder 80, so as to exert pressure on the farm tools, the flow of the falling overflow channel 192 is adjusted by the proportional overflow valve 61, the pressure inside the rod cavity 81 of the lifting oil cylinder 80 can be adjusted, and thus the pressure exerted on the farm tools can be adjusted;

[0070] As an improvement, the electric control unit controls the electromagnetic flow regulating valve 40 to be opened, the second oil supply channel 22 between the second outlet of the electromagnetic flow control valve 20 and the valve body oil inlet 311 of the electric control reversing valve module is opened, the hydraulic oil flow flowing into the rod cavity 81 of the lifting oil cylinder 80 is increased, and thus the pressure inside the rod cavity 81 of the lifting oil cylinder 80 is further increased, and the farm tools can be exerted with greater pressure;

[0071] S40, the floating control of the farm tools is as follows:

[0072] The electric control unit controls the proportional overflow valve 61 to be closed and controls the electric control reversing valve module to be closed, the falling overflow channel 192 is closed, the lifting oil path side of the electric control reversing valve module and the descending oil path side of the electric control reversing valve module are disconnected, the hydraulic oil between the first working oil port 313 of the electric control reversing valve module, the lifting oil port connecting channel, the lifting oil port 12 and the rodless cavity 82 of the lifting oil cylinder 80 does not flow, and the hydraulic oil between the second working oil port 314 of the electric control reversing valve module, the descending oil port connecting channel, the descending oil port 13 and the rod cavity 81 of the lifting oil cylinder 80 does not flow; the pressure inside the rodless cavity 82 of the lifting oil cylinder 80 and the pressure inside the rod cavity 81 of the lifting oil cylinder 80 are in a balanced state, and the farm tools are in a floating state.

[0073] In the embodiment of the application, the electric control unit comprises a control panel, and control switches corresponding to the electromagnetic flow control valve 20, the electric control reversing valve module, the electromagnetic flow regulating valve 40, the proportional reversing valve 50 and the proportional overflow valve 61 are arranged on the control panel.

[0074] Generally, the control switch of the electromagnetic flow control valve 20 is a toggle switch, which has three positions, the middle position is the closed position, one side position is the position for opening the first and second outlets, and the other side position is the position for opening the third outlet.

[0075] For the electrically controlled reversing valve module, when the electrically controlled reversing valve module is an electromagnetic reversing valve, the control switch of the electrically controlled reversing valve module is a toggle switch, which has three positions, the middle position is the closed position, one side position is the position for opening the lifting oil way side, and the other side position is the position for opening the falling oil way side, when the electrically controlled reversing valve module is a combined structure, a toggle switch is arranged at the lifting electromagnetic reversing valve 35 and the falling electromagnetic reversing valve 36 respectively, which has two positions, one is the position for adjusting the oil supply, and the other is the position for reversing the oil return.

[0076] The control switch of the proportional reversing valve 50 is a combined switch of a knob and a button, the knob is used for adjusting the flow size, and the button is used for adjusting the flow direction.

[0077] The control switch of the proportional overflow valve 61 is a knob switch, which is rotated in the forward direction to open and adjust the flow size, and is rotated in the reverse direction to adjust the flow direction and close.

[0078] In some other embodiments, the electric control unit can also be provided in the following structure, which includes a touch display screen, and the touch display screen has touch switches corresponding to the electromagnetic flow control valve 20, the electrically controlled reversing valve module, the electromagnetic flow control valve 40, the proportional reversing valve 50, and the proportional overflow valve 61 respectively, which are used for control and adjustment.

[0079] Specifically, the structure and control principle of the electric control unit are known technologies, and a person skilled in the art can select according to the use requirement, and the specific structure and working principle are not described here.

[0080] Although the specific embodiments of the present application are described above, those skilled in the art should understand that the described embodiments are only part of the embodiments of the present application, not all the embodiments, which are only examples, and the protection scope of the present application is defined by the claims. Those skilled in the art can make various changes or modifications to the embodiments without departing from the principles and essence of the present application, and such changes and modifications fall within the protection scope of the present application.

Claims

1. A tractor-mounted electrically controlled lifting valve assembly, characterized in that, The valve body is provided with a valve group oil inlet, a lifting oil port, a falling oil port and a valve group oil return port, and further comprises an electromagnetic flow control valve, an electrically-controlled reversing valve module, an electromagnetic flow regulating valve, a proportional reversing valve, a proportional overflow valve and an oil supplement valve which are respectively installed on the valve body, and an oil return channel is arranged between the outlet of the proportional overflow valve and the valve group oil return port; the inlet of the electromagnetic flow control valve is connected to the valve group oil inlet, and a first oil supply channel and a second oil supply channel are respectively arranged between the first outlet of the electromagnetic flow control valve, the second outlet of the electromagnetic flow control valve and the valve body oil inlet of the electrically-controlled reversing valve module, the electromagnetic flow regulating valve is connected in series to the second oil supply channel, and the valve body oil return port of the electrically-controlled reversing valve module is connected to the oil return channel; a lifting oil port connecting channel is arranged between the first working oil port of the electrically-controlled reversing valve module and the lifting oil port, a falling oil port connecting channel is arranged between the second working oil port of the electrically-controlled reversing valve module and the falling oil port, and the proportional reversing valve is connected in series to the lifting oil port connecting channel; a falling overflow channel is arranged between the falling oil port connecting channel and the inlet of the proportional overflow valve, an oil supplement channel is arranged between the falling oil port connecting channel or the falling overflow channel and the oil return channel, and the oil supplement valve is connected in series to the oil supplement channel.

2. The electronically controlled poppet valve set for a tractor according to claim 1, wherein A valve group overflow channel is arranged between the pump oil channel between the valve group oil inlet and the inlet of the electromagnetic flow control valve and the oil return channel, and a first safety valve is connected in series to the valve group overflow channel; a lifting overflow channel is arranged between the lifting oil port and the oil return channel, and a second safety valve is connected in series to the lifting overflow channel.

3. The electronically controlled poppet valve set for a tractor according to claim 2, wherein The electrically-controlled reversing valve module comprises a hydraulic reversing valve, a lifting electromagnetic reversing valve and a falling electromagnetic reversing valve; the working oil port of the lifting electromagnetic reversing valve is connected to the regulating oil port on the lifting oil path side of the hydraulic reversing valve, the working oil port of the falling electromagnetic reversing valve is connected to the regulating oil port on the falling oil path side of the hydraulic reversing valve; the inlet of the lifting electromagnetic reversing valve and the inlet of the falling electromagnetic reversing valve are respectively connected to the pump oil channel; and the oil return port of the lifting electromagnetic reversing valve and the oil return port of the falling electromagnetic reversing valve are respectively connected to the oil return channel.

4. The electronically controlled poppet valve set for a tractor according to claim 3, wherein A damping plug is connected in series to the regulating oil path between the working oil port of the lifting electromagnetic reversing valve and the regulating oil port on the lifting oil path side of the hydraulic reversing valve and the regulating oil path between the working oil port of the falling electromagnetic reversing valve and the regulating oil port on the falling oil path side of the hydraulic reversing valve.

5. The electronically controlled poppet valve set for a tractor according to claim 4, wherein A reversing control channel of the valve group overflow channel is arranged in the valve body and connected between the pump oil channel and the first safety valve, and the inlet of the lifting electromagnetic reversing valve and the inlet of the falling electromagnetic reversing valve are respectively connected to the reversing control channel.

6. The electronically controlled poppet valve set for a tractor according to claim 1, wherein The first safety valve and the second safety valve are overflow valves.

7. The electronically controlled poppet valve set for a tractor according to claim 1, wherein A bypass oil port is further arranged on the valve body and connected to the third oil supply port of the electromagnetic flow control valve.

8. The electronically controlled poppet valve set for a tractor according to any one of claims 1 to 7, characterized by The valve body is further provided with a first pressure tapping, a second pressure tapping and a third pressure tapping, the first pressure tapping is communicated with the inlet of the electromagnetic flow control valve, the second pressure tapping is communicated with the lifting oil port, and the third pressure tapping is communicated with the inlet of the proportional overflow valve; and a pressure measuring component is arranged on each of the first pressure tapping, the second pressure tapping and the third pressure tapping.

9. A method of controlling a tractor hoist system, the method comprising: The tractor lifting system comprises the electric control lifting valve group for tractors according to any one of claims 1 to 8, an oil pump connected to the oil inlet of the valve group, at least one lifting oil cylinder, and an electric control unit, the lifting oil port is connected to the rodless chamber of at least one of the lifting oil cylinders, the lowering oil port is connected to the rod chamber of at least one of the lifting oil cylinders, the electromagnetic flow control valve, the electric control reversing valve module, the electromagnetic flow regulating valve, the proportional reversing valve and the proportional overflow valve of the electric control lifting valve are electrically connected to the electric control unit, and the piston rod of at least one of the lifting oil cylinders is connected to a farm implement; and the tractor lifting system control method comprises: S10, the lifting control of the farm implement is as follows: The electric control unit controls the electromagnetic flow control valve to open and the electric control reversing valve module to open, and the lifting oil path side of the electric control reversing valve module is powered; after the lifting oil path side of the electric control reversing valve module is powered, the first working oil port of the electric control reversing valve module is communicated with the valve body oil inlet of the electric control reversing valve module, and the second working oil port of the electric control reversing valve module is communicated with the valve body oil return port of the electric control reversing valve module; the oil pump is filled with hydraulic oil pumped from the valve group oil inlet, the hydraulic oil flowing out of the first outlet of the electromagnetic flow control valve flows to the valve body oil inlet of the electric control reversing valve module through the first oil supply channel, the hydraulic oil flowing out of the first working oil port of the electric control reversing valve module flows to the lifting oil port through the lifting oil port connecting channel and the proportional reversing valve, and then flows to the rodless chamber of the lifting oil cylinder through the lifting oil port, so as to push the piston rod of the lifting oil cylinder to extend and drive the farm implement to lift; the piston of the lifting oil cylinder pushes the hydraulic oil in the rod chamber of the lifting oil cylinder to flow out, and the hydraulic oil flowing out of the rod chamber of the lifting oil cylinder flows through the lowering oil port, the second working oil port of the electric control reversing valve module and the valve body oil return port of the electric control reversing valve module, and then flows into the oil return channel; When the lifting speed is increased, the electronic control unit controls the electromagnetic flow regulating valve to open, the proportional overflow valve to open, the second oil supply channel to open, and the hydraulic oil flow of the valve body oil inlet of the electronic control reversing valve module to increase, so that the hydraulic oil flow into the rodless chamber of the lifting cylinder increases, and the lifting speed of the implement is increased. Correspondingly, the hydraulic oil flow from the rod chamber of the lifting cylinder increases, and the hydraulic oil from the inside of the rod chamber of the lifting cylinder flows into the descending oil inlet connection channel through the descending oil inlet. Part of the hydraulic oil in the descending oil inlet connection channel flows through the second working oil inlet of the electronic control reversing valve module, the valve body return oil inlet of the electronic control reversing valve module, and then flows into the return oil channel. Another part of the hydraulic oil in the descending oil inlet connection channel flows through the falling overflow channel and the proportional overflow valve, and then flows into the return oil channel. S20 The descending control of the implement is as follows: The electronic control unit controls the electromagnetic flow regulating valve to close, controls the proportional reversing valve to open so that the proportional reversing valve switches to the reverse flow state, controls the electronic control reversing valve module to open, and makes the descending oil path side of the electronic control reversing valve module electrified. The first working oil inlet of the electronic control reversing valve module is in communication with the valve body return oil inlet of the electronic control reversing valve module, and the second working oil inlet of the electronic control reversing valve module is in communication with the valve body oil inlet of the electronic control reversing valve module. When the electronic control unit controls the electromagnetic flow control valve to close, the electromagnetic flow control valve does not supply oil, the piston rod of the lifting cylinder is retracted under the weight of the implement, and the weight descent of the implement is realized. The electronic control unit controls the opening degree of the proportional reversing valve to adjust the outflow speed of the hydraulic oil in the rodless chamber of the lifting cylinder, and adjusts the descending speed of the implement under its own weight. The piston rod of the lifting cylinder is retracted, the volume of the rod chamber of the lifting cylinder increases, the pressure in the rod chamber of the lifting cylinder decreases, and the hydraulic oil is sucked back through the oil supplement channel to supplement the oil in the rod chamber of the lifting cylinder, so as to balance the pressure difference between the rod chamber of the lifting cylinder and the rodless chamber of the lifting cylinder. When the electronic control unit controls the electromagnetic flow control valve to open, the electromagnetic flow control valve supplies oil to the valve body oil inlet of the electronic control reversing valve module. The hydraulic oil flowing out of the first outlet of the electromagnetic flow control valve flows to the rod chamber of the lifting cylinder through the first oil supply channel, the valve body oil inlet of the electronic control reversing valve module, the second working oil inlet of the electronic control reversing valve module, the descending oil inlet connection channel, and the descending oil inlet, increases the pressure in the rod chamber of the lifting cylinder, and forcibly pushes the piston rod of the lifting cylinder to fall, so as to realize the forced descent of the implement. When the agricultural implement is lowered, the piston rod of the lifting oil cylinder is retracted, the hydraulic oil inside the rodless chamber of the lifting oil cylinder is pressed out, the hydraulic oil flowing out of the rodless chamber of the lifting oil cylinder flows through the lifting oil port, the lifting oil port connecting channel, the proportional reversing valve, the first working oil port of the electric control reversing valve module, the valve body return oil port of the electric control reversing valve module, and then flows into the return oil channel; In the lowering force control of the agricultural implement, the electric control unit controls the electromagnetic flow control valve to open, opens the second oil supply channel between the second outlet of the electromagnetic flow control valve and the valve body oil inlet of the electric control reversing valve module, and increases the flow of hydraulic oil flowing into the rod cavity of the lifting oil cylinder. After the agricultural implement is lowered, the electric control unit controls the electromagnetic flow control valve to be in an open state, controls the electric control reversing valve module to be in an open state and to be powered on at the descending oil path side of the electric control reversing valve module, controls the proportional overflow valve to be in an open state, and supplies oil from the electromagnetic flow control valve to the valve body oil inlet of the electric control reversing valve module. The hydraulic oil flowing out of the first outlet of the electromagnetic flow control valve flows to the rod cavity of the lifting oil cylinder through the first oil supply channel, the valve body oil inlet of the electric control reversing valve module, the second working oil port of the electric control reversing valve module, the descending oil port connecting channel, and the descending oil port. The pressure on the piston of the lifting oil cylinder is applied by the hydraulic oil flowing into the rod cavity of the lifting oil cylinder, so as to apply a downward pressure on the agricultural implement. The flow of the lowering overflow channel is adjusted by the proportional overflow valve, the pressure inside the rod cavity of the lifting oil cylinder is adjusted, and thus the downward pressure applied on the agricultural implement is adjusted. In the floating control of the agricultural implement, the electric control unit controls the proportional overflow valve to be closed, controls the electric control reversing valve module to be closed, the lowering overflow channel is closed, the lifting oil path side of the electric control reversing valve module and the descending oil path side of the electric control reversing valve module are disconnected, the hydraulic oil between the first working oil port of the electric control reversing valve module, the lifting oil port connecting channel, the lifting oil port, and the rodless chamber of the lifting oil cylinder does not flow, the hydraulic oil between the second working oil port of the electric control reversing valve module, the descending oil port connecting channel, the descending oil port, and the rod cavity of the lifting oil cylinder does not flow, the pressure inside the rodless chamber of the lifting oil cylinder is balanced with the pressure inside the rod cavity of the lifting oil cylinder, and the agricultural implement is in a floating state. In the lowering force control of the agricultural implement, the electric control unit controls the electromagnetic flow control valve to open, opens the second oil supply channel between the second outlet of the electromagnetic flow control valve and the valve body oil inlet of the electric control reversing valve module, and increases the flow of hydraulic oil flowing into the rod cavity of the lifting oil cylinder.

10. The method of claim 9, wherein, ​

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