An electro-hydraulic copying system
The electro-hydraulic contouring system's leveling, lifting, and damping mechanisms solve the problem of agricultural machinery tilting, swaying, or floating up and down on uneven roads, achieving automated leveling and lifting, improving work quality and efficiency, and adapting to the needs of various agricultural implements.
Patent Information
- Application Number
- CN202211103121.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2022-09-09
- Publication Date
- 2025-11-28
- Estimated Expiration
- 2042-09-09
AI Technical Summary
Existing technologies struggle to effectively prevent material defects. One key issue is the poor stability of existing agricultural machinery. On uneven surfaces, the implements tend to tilt, sway, or float up and down with the tractor, leading to reduced productivity and reliability, and consequently impacting work quality and efficiency.
An electro-hydraulic contouring system is adopted, including a leveling mechanism, a lifting mechanism, and an adjustable damping mechanism. The lifting and leveling of the implements are automated through a horizontal tilt sensor and a controller. The hydraulic oil tank and the air pump combine to achieve automated leveling and lifting using electromagnetic proportional valves and pneumatic solenoid valves. A bridge circuit and a flow sensor are set up to achieve height adjustment and damping control of the agricultural machinery.
It effectively prevents agricultural machinery from tilting, swaying, or floating up and down, improves the quality and efficiency of operations, adapts to the leveling needs of various agricultural implements, reduces costs, and increases the degree of mechanization.
Smart Images
Figure CN115573954B_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application belongs to the technical field of agricultural machinery, and particularly relates to an electro-hydraulic profiling system. BACKGROUND
[0002] For some areas with scarce land resources, simply relying on increasing the cultivated area cannot fully achieve the purpose of increasing production, and it is also necessary to improve the mechanization degree of agricultural production. Agricultural machinery is various in types, and different types of agricultural machinery have different requirements for the operation of the profiling leveling system. Traditional agricultural machinery usually does not have the function of profiling leveling. At present, tractors are the preferred power of agricultural machinery, and they play an important role in various aspects of agricultural production such as tillage, planting, cultivation management, harvesting, postpartum treatment, etc. At the same time, most agricultural implements are operated by being hung on the tractor. In this way, when the tractor is walking on uneven road surface, the agricultural implement will tilt and swing or float up and down with the tractor, which can easily lead to the reduction of stability and reliability of the agricultural implement, and further can lead to the reduction of production efficiency, and also can seriously affect the operation quality of the agricultural implement. In order to solve the above problems, it is urgent to provide an electro-hydraulic profiling system which can effectively prevent the agricultural implement from tilting and swinging or floating up and down, so as to effectively improve the operation quality of the agricultural machinery and promote the intelligent process of the agricultural machinery. SUMMARY
[0003] In view of the problems existing in the prior art, the present application provides an electro-hydraulic profiling system which can automatically realize the lifting and leveling operation of the working implement, can effectively improve the operation quality, can effectively reduce the amplitude of the tilting and swinging or floating up and down of the agricultural implement, has a wide range of applications, and can meet the leveling operation requirements of various agricultural implements.
[0004] In order to achieve the above purpose, the present application provides an electro-hydraulic profiling system which comprises an engine, a hydraulic oil tank, a leveling mechanism, a cooling mechanism, a lifting mechanism, an adjustable damping mechanism and a controller.
[0005] The leveling mechanism is composed of a leveling drive pump, a three-position four-way reversing valve one, a safety valve one, a leveling hydraulic cylinder one, a leveling hydraulic cylinder two, a synchronous cylinder, a one-way valve one, a one-way valve two, an overflow valve and a horizontal inclination sensor; the leveling drive pump is coaxially connected with the engine, the oil suction port of the leveling drive pump is connected with the hydraulic oil tank through an oil suction pipeline, the oil discharge port of the leveling drive pump is connected with the P port of the three-position four-way reversing valve one, and the three-position four-way reversing valve one is also connected with the hydraulic oil tank through the safety valve one; the B port of the three-position four-way reversing valve one is respectively connected with the rodless cavity oil port of the leveling hydraulic cylinder one and the rod cavity oil port of the leveling hydraulic cylinder two, and the A port thereof is respectively connected with the oil port of the second cavity and the oil port of the fourth cavity of the synchronous cylinder; the oil port of the first cavity and the oil port of the third cavity of the synchronous cylinder are respectively connected with the rod cavity oil port of the leveling hydraulic cylinder one and the rodless cavity oil port of the leveling hydraulic cylinder two; the rod cavity oil port of the leveling hydraulic cylinder one is connected with the oil inlet port of the one-way valve one, the rodless cavity oil port of the leveling hydraulic cylinder two is connected with the oil inlet port of the one-way valve two, and the oil outlet port of the one-way valve one and the oil outlet port of the one-way valve two are both connected with the hydraulic oil tank through the overflow valve; the leveling hydraulic cylinder one and the leveling hydraulic cylinder two are arranged correspondingly, one end of each is installed on the tractor frame, and the other end is installed on the agricultural implement, for realizing leveling operation in two opposite directions; the horizontal inclination sensor is installed on the agricultural implement;
[0006] The cooling mechanism is composed of an electromagnetic proportional valve, a stop valve, a cooler, an oil temperature sensor and a comparator; the B port of the electromagnetic proportional valve is connected with a cold water source through the stop valve, the A port thereof is connected with the cooling liquid inlet of the cooler, the cooling liquid outlet of the cooler is connected with a water collecting device; the oil inlet of the cooler is connected with the T port of the three-position four-way reversing valve one, and the oil outlet thereof is connected with the hydraulic oil tank; the oil temperature sensor is installed in the hydraulic oil tank and is connected with the comparator;
[0007] The lifting mechanism is connected with the engine coaxially by the lifting driving pump, and the oil suction port of the lifting driving pump is connected with the hydraulic oil tank through the oil suction pipeline, and the oil discharge port is connected with the hydraulic oil tank through the safety valve two, and is also connected with the P port of the three-position four-way reversing valve two, the B port of the three-position four-way reversing valve two is connected with the rod cavity oil port of the lifting hydraulic cylinder, and the A port is connected with the rod cavity oil port of the lifting hydraulic cylinder through the bridge circuit; the piston rod of the lifting hydraulic cylinder is connected with the agricultural implement, and is used for realizing the height adjustment of the agricultural implement; the bridge circuit is composed of the speed regulating valve, the one-way valve six, the one-way valve five, the flow sensor one, the one-way valve three, the flow sensor two and the one-way valve four; the oil inlet of the speed regulating valve is connected with the oil outlet of the one-way valve six and the oil outlet of the one-way valve five respectively, the oil outlet is divided into two ways, one way is connected with the oil inlet of the one-way valve three through the flow sensor one, the other way is connected with the oil inlet of the one-way valve four through the flow sensor two, the oil outlet of the one-way valve four is connected with the A port of the three-position four-way reversing valve two and the oil inlet of the one-way valve six, and the oil outlet of the one-way valve three is connected with the oil inlet of the one-way valve five and the rod cavity oil port of the lifting hydraulic cylinder;
[0008] The adjustable damping mechanism is composed of an air pressure pump, an air pressure safety valve, a pneumatic electromagnetic valve one, a pneumatic electromagnetic valve two, a high-pressure pressure reducing valve, a two-position two-way electromagnetic valve four, a medium-pressure pressure reducing valve, a two-position two-way electromagnetic valve five, a low-pressure pressure reducing valve, a two-position two-way electromagnetic valve one, a pilot pressure control valve, a two-position two-way electromagnetic valve three, a two-position two-way electromagnetic valve two, a liquid-gas mixed cylinder and a high-pressure liquid cylinder; the air pressure pump is connected with the engine coaxially, the air outlet is connected with the air pressure safety valve, and is also connected with the A port of the pneumatic electromagnetic valve two and the B port of the pneumatic electromagnetic valve one, the B port of the pneumatic electromagnetic valve two is communicated with the external atmosphere; the A port of the pneumatic electromagnetic valve one is connected with the B port of the two-position two-way electromagnetic valve four through the high-pressure pressure reducing valve, is also connected with the B port of the two-position two-way electromagnetic valve five through the medium-pressure pressure reducing valve, is also connected with the B port of the two-position two-way electromagnetic valve one through the low-pressure pressure reducing valve, and is also connected with the air inlet of the pilot pressure control valve and the B port of the two-position two-way electromagnetic valve three; the A port of the two-position two-way electromagnetic valve four, the A port of the two-position two-way electromagnetic valve five and the A port of the two-position two-way electromagnetic valve one are communicated with each other and connected with the control air port of the pilot pressure control valve; the air outlet of the pilot pressure control valve is connected with the B port of the two-position two-way electromagnetic valve two; the oil cavity of the liquid-gas mixed cylinder is filled with hydraulic oil, the air cavity is filled with air, and the air cavity air port is connected with the A port of the two-position two-way electromagnetic valve two and the A port of the two-position two-way electromagnetic valve three; the rod cavity of the high-pressure liquid cylinder is filled with hydraulic oil, the rod cavity oil port is connected with the oil cavity oil port of the liquid-gas mixed cylinder, the rod cavity oil port is communicated with the external atmosphere, and the piston rod is coaxially arranged with the piston rod of the lifting hydraulic cylinder, and the two piston rods are fixedly connected at the end portions;
[0009] The controller is connected with the electromagnetic proportional valve through a proportional amplifier, and the controller is also connected with a comparator, a horizontal inclination sensor, a flow sensor one, a flow sensor two, a three-position four-way reversing valve one, a three-position four-way reversing valve two, a pneumatic electromagnetic valve two, a pneumatic electromagnetic valve one, a two-position two-way electromagnetic valve three, a two-position two-way electromagnetic valve two, a two-position two-way electromagnetic valve four, a two-position two-way electromagnetic valve five, a two-position two-way electromagnetic valve one, a stop valve and an engine.
[0010] Further, in order to avoid impurities from entering the system and affecting the normal operation of the hydraulic components, the leveling mechanism further comprises a filter one connected in series on the oil suction pipeline of the leveling drive pump, and the lifting mechanism further comprises a filter two connected in series on the oil suction pipeline of the lifting drive pump.
[0011] As a preferred, the controller is a PLC controller.
[0012] As a preferred, when the three-position four-way reversing valve one works at the left position with electricity, the oil passage between the P port and the A port is communicated, the oil passage between the T port and the B port is communicated, when the three-position four-way reversing valve one works at the middle position without electricity, the A port and the B port are both cut off, the oil passage between the P port and the T port is communicated, when the three-position four-way reversing valve one works at the right position with electricity, the oil passage between the P port and the B port is communicated, the oil passage between the A port and the T port is communicated.
[0013] As a preferred, when the three-position four-way reversing valve two works at the left position with electricity, the oil passage between the P port and the A port is communicated, the oil passage between the T port and the B port is communicated, when the three-position four-way reversing valve two works at the middle position without electricity, the oil passages between the A port, the B port, the P port and the T port are communicated with each other, when the three-position four-way reversing valve two works at the right position with electricity, the oil passage between the P port and the B port is communicated, the oil passage between the A port and the T port is communicated.
[0014] As a preferred, when the electromagnetic proportional valve is without electricity, the opening degree between the A port and the B port in the valve is 0, when the electromagnetic proportional valve is with electricity, the opening degree between the A port and the B port in the valve gradually increases with the increase of the current.
[0015] As a preferred, the two-position two-way electromagnetic valve three, the two-position two-way electromagnetic valve two, the two-position two-way electromagnetic valve four, the two-position two-way electromagnetic valve five and the two-position two-way electromagnetic valve one work at the lower position with electricity, the gas passage between the A port and the B port is communicated, work at the upper position without electricity, the gas passage between the A port and the B port is disconnected.
[0016] As a preferred, the pneumatic electromagnetic valve one and the pneumatic electromagnetic valve two are both two-position two-way electromagnetic reversing valves, work at the right position with electricity, the gas passage between the A port and the B port is communicated, work at the left position without electricity, the gas passage between the A port and the B port is disconnected.
[0017] In the present application, the rod cavity of the leveling hydraulic cylinder one and the rodless cavity of the leveling hydraulic cylinder two are connected with the first cavity oil port and the third cavity oil port of the synchronous cylinder respectively, and the second cavity oil port and the fourth cavity oil port of the synchronous cylinder are connected with the A port of the three-position four-way reversing valve one, so that the synchronization of the oil supply process to the rod cavity of the leveling hydraulic cylinder one and the rodless cavity of the leveling hydraulic cylinder two can be ensured, and the synchronization of the oil discharge process in the rod cavity of the leveling hydraulic cylinder one and the rodless cavity of the leveling hydraulic cylinder two can also be ensured, thereby the action speed and stroke of the piston rod of the leveling hydraulic cylinder one and the piston rod of the leveling hydraulic cylinder two are basically the same, and the synchronization mode of one piston rod extending and the other piston rod retracting can effectively increase the leveling speed. The one-way valve one is connected between the rod cavity of the leveling hydraulic cylinder one and the overflow valve, so that when the leveling hydraulic cylinder one reaches the maximum stroke and the leveling hydraulic cylinder two has not reached the maximum stroke, the high-pressure oil generated subsequently in the leveling hydraulic cylinder one is discharged into the hydraulic oil tank through the one-way valve one and the overflow valve, thereby the synchronization of the actions of the leveling hydraulic cylinder one and the leveling hydraulic cylinder two can be effectively ensured. The one-way valve two is connected between the rod cavity of the leveling hydraulic cylinder two and the overflow valve, so that when the leveling hydraulic cylinder two reaches the maximum stroke and the leveling hydraulic cylinder one has not reached the maximum stroke, the high-pressure oil generated subsequently in the leveling hydraulic cylinder two is discharged into the hydraulic oil tank through the one-way valve two and the overflow valve, thereby the synchronization of the actions of the leveling hydraulic cylinder one and the leveling hydraulic cylinder two can be effectively ensured. The cooler is arranged, so that when the leveling hydraulic cylinder frequently acts and the oil temperature rises greatly, the hydraulic oil can be effectively cooled. The oil temperature sensor is arranged, so that the actual oil temperature signal of the hydraulic oil tank can be collected in real time, and the actual oil temperature signal can be compared with the set oil temperature value by the comparator, so that when the actual oil temperature is higher than the set value, a high-temperature signal is sent to the controller, so that the controller automatically connects the cooling water source of the cooler, thereby realizing the automation of the cooling process. The bridge circuit is arranged, so that the action speed of the lowering hydraulic cylinder can be controlled by the opening degree of the speed regulating valve, the sensitivity of the lifting mechanism can be adjusted, the lowering hydraulic cylinder can be locked by the opening degree of the speed regulating valve being 0, thereby the up-and-down floating of the lifting mechanism can be prevented, and the inclination swing or up-and-down floating of the agricultural implement can be effectively avoided. The piston rod of the high-pressure cylinder is coaxially and fixedly connected with the piston rod of the lifting hydraulic cylinder, the rodless cavity of the high-pressure cylinder is connected with the oil cavity of the liquid-gas mixing cylinder, and the gas cavity of the liquid-gas mixing cylinder is connected with the A ports of the two-position two-way electromagnetic valves two and three, so that the damping level in the passive damping mode can be conveniently and automatically set, and the lifting mechanism can work in the passive damping mode that has been set, thereby the inclination swing or up-and-down floating amplitude of the agricultural implement with the tractor can be effectively reduced, and the working quality of the agricultural implement can be effectively ensured.By setting high pressure reducing valve, medium pressure reducing valve and low pressure reducing valve at the same time, and making them connect with the control gas port of pilot pressure control valve through two-position two-way electromagnetic valve four, two-position two-way electromagnetic valve five and two-position two-way electromagnetic valve one respectively, the control pressure of pilot pressure control valve can be conveniently controlled.
[0018] The application can automatically realize the lifting and leveling process of the working implement, and effectively improve the working quality. For the lifting mechanism, in the traditional technical solution, the cost of the means for determining the position of the hydraulic cylinder by using the bidirectional flow sensor is extremely expensive, and in the application, the technical means of bridge circuit plus two conventional flow sensors is creatively adopted, which can realize bidirectional monitoring of flow and greatly reduce the cost, so that the bidirectional flow monitoring process is more easily realized. For the leveling mechanism, two leveling hydraulic cylinders are arranged, and the action modes of the piston rods thereof are synchronous and reverse, which can effectively improve the leveling efficiency. For the problem of large heat generation of the leveling mechanism, the cooling mechanism is arranged, which can ensure that the temperature of the hydraulic oil can be maintained within the appropriate range. For the adjustable damping mechanism, it can have three damping levels, which can meet the use requirements of different agricultural implements, and can ensure that the agricultural implement will not greatly tilt and swing or float up and down with the tractor when the tractor is running on uneven road, so that the working quality of the agricultural implement can be effectively ensured. BRIEF DESCRIPTION OF DRAWINGS
[0019] Figure 1 It is the hydraulic principle diagram of the application.
[0020] In the figure: 1, engine, 2, leveling drive pump, 3, filter one, 4, safety valve one, 5, cooler, 6, hydraulic oil tank, 7, oil temperature sensor, 8, comparator, 9, controller, 10, proportional amplifier, 11, electromagnetic proportional valve, 12, stop valve, 13, three-position four-way reversing valve one, 14, synchronous cylinder, 15, one-way valve one, 16, one-way valve two, 17, overflow valve, 18, leveling hydraulic cylinder one, 19, leveling hydraulic cylinder two, 20, lifting drive pump, 21, filter two, 22, safety valve two, 23, one-way valve three, 24, one-way valve four, 25, one-way valve five, 26, three-position four-way reversing valve two, 27, one-way valve six, 28, speed regulating valve, 29, flow sensor one, 30, flow sensor two, 31, lifting hydraulic cylinder, 32, high pressure cylinder, 33, liquid-gas mixing cylinder, 34, two-position two-way electromagnetic valve two, 35, two-position two-way electromagnetic valve three, 36, pilot pressure control valve, 37, two-position two-way electromagnetic valve four, 38, high pressure reducing valve, 39, two-position two-way electromagnetic valve five, 40, medium pressure reducing valve, 41, two-position two-way electromagnetic valve one, 42, low pressure reducing valve, 43, pneumatic electromagnetic valve one, 44, air pressure pump, 45, air pressure safety valve, 46, pneumatic electromagnetic valve two. Detailed Implementation
[0021] The present invention will be further described below.
[0022] like Figure 1 As shown, the present invention provides an electro-hydraulic contouring system, including an engine 1, a hydraulic oil tank 6, a leveling mechanism, a cooling mechanism, a lifting mechanism, an adjustable damping mechanism, and a controller 9;
[0023] The leveling mechanism consists of a leveling drive pump 2, a three-position four-way directional valve 13, a safety valve 4, a leveling hydraulic cylinder 18, a leveling hydraulic cylinder 2 19, a synchronizing cylinder 14, a check valve 15, a check valve 2 16, an overflow valve 17, and a horizontal tilt sensor. The leveling drive pump 2 is coaxially connected to the engine 1. The oil suction port of the leveling drive pump 2 is connected to the hydraulic oil tank 6 through an oil suction pipe, and the oil discharge port of the leveling drive pump 2 is connected to the P port of the three-position four-way directional valve 13. It is also connected to the hydraulic oil tank 6 through the safety valve 4. The B port of the three-position four-way directional valve 13 is connected to the rodless chamber oil port of the leveling hydraulic cylinder 18 and the rod chamber oil port of the leveling hydraulic cylinder 2 19, respectively. Its A port is connected to the oil in the second chamber of the synchronizing cylinder 14. The oil ports of the first and third chambers of the synchronizing cylinder 14 are connected to the oil ports of the rod chamber of the first leveling hydraulic cylinder 18 and the oil ports of the rodless chamber of the second leveling hydraulic cylinder 19, respectively. The oil port of the rod chamber of the first leveling hydraulic cylinder 18 is connected to the oil inlet of the first check valve 15, and the oil port of the rodless chamber of the second leveling hydraulic cylinder 19 is connected to the oil inlet of the second check valve 16. The oil outlets of the first check valve 15 and the second check valve 16 are both connected to the hydraulic oil tank 6 through the overflow valve 17. The first leveling hydraulic cylinder 18 and the second leveling hydraulic cylinder 19 are arranged correspondingly, with one end mounted on the tractor frame and the other end mounted on the agricultural implement, for realizing leveling operations in two opposite directions. The horizontal tilt sensor is mounted on the agricultural implement.
[0024] The cooling mechanism consists of an electromagnetic proportional valve 11, a shut-off valve 12, a cooler 5, an oil temperature sensor 7, and a comparator 8. The B port of the electromagnetic proportional valve 11 is connected to a cold water source through the shut-off valve 12, its A port is connected to the coolant inlet of the cooler 5, and the coolant outlet of the cooler 5 is connected to a water collection device. The oil inlet of the cooler 5 is connected to the T port of a three-position four-way directional valve 13, and its oil outlet is connected to a hydraulic oil tank 6. The oil temperature sensor 7 is installed in the hydraulic oil tank 6 and is connected to the comparator 8.
[0025] The lifting mechanism is composed of a lifting drive pump 20, a safety valve 22, a three-position four-way reversing valve 26, a lifting hydraulic cylinder 31 and a bridge circuit; the lifting drive pump 20 is coaxially connected with the engine 1; the oil suction port of the lifting drive pump 20 is connected with the hydraulic oil tank 6 through an oil suction pipeline, and the oil discharge port is connected with the hydraulic oil tank 6 through the safety valve 22, and is also connected with the P port of the three-position four-way reversing valve 26; the B port of the three-position four-way reversing valve 26 is connected with the rod cavity oil port of the lifting hydraulic cylinder 31, and the A port is connected with the rodless cavity oil port of the lifting hydraulic cylinder 31 through the bridge circuit; the piston rod of the lifting hydraulic cylinder 31 is connected with the agricultural implement, and is used for adjusting the height of the agricultural implement; the bridge circuit is composed of a speed regulating valve 28, a one-way valve 27, a one-way valve 25, a flow sensor 29, a one-way valve 23, a flow sensor 30 and a one-way valve 24; the oil inlet of the speed regulating valve 28 is connected with the oil outlet of the one-way valve 27 and the oil outlet of the one-way valve 25 respectively, the oil outlet is divided into two paths, one path is connected with the oil inlet of the one-way valve 23 through the flow sensor 29, and the other path is connected with the oil inlet of the one-way valve 24 through the flow sensor 30, the oil outlet of the one-way valve 24 is connected with the A port of the three-position four-way reversing valve 26 and the oil inlet of the one-way valve 27, and the oil outlet of the one-way valve 23 is connected with the oil inlet of the one-way valve 25 and the rodless cavity oil port of the lifting hydraulic cylinder 31;
[0026] The adjustable damping mechanism is composed of the air pressure pump 44, the air pressure safety valve 45, the pneumatic electromagnetic valve one 43, the pneumatic electromagnetic valve two 46, the high-pressure pressure reducing valve 38, the two-position two-way electromagnetic valve four 37, the medium-pressure pressure reducing valve 40, the two-position two-way electromagnetic valve five 39, the low-pressure pressure reducing valve 42, the two-position two-way electromagnetic valve one 41, the pilot pressure control valve 36, the two-position two-way electromagnetic valve three 35, the two-position two-way electromagnetic valve two 34, the liquid-air mixed cylinder 33 and the high-pressure hydraulic cylinder 32; the air pressure pump 44 is coaxially connected with the engine 1, the air outlet thereof is connected with the air pressure safety valve 45, and the air pressure pump 44 is also respectively connected with the A port of the pneumatic electromagnetic valve two 46 and the B port of the pneumatic electromagnetic valve one 43, the B port of the pneumatic electromagnetic valve two 46 is communicated with the external atmosphere; the A port of the pneumatic electromagnetic valve one 43 is connected with the B port of the two-position two-way electromagnetic valve four 37 through the high-pressure pressure reducing valve 38, and is also connected with the B port of the two-position two-way electromagnetic valve five 39 through the medium-pressure pressure reducing valve 40, and is also connected with the B port of the two-position two-way electromagnetic valve one 41 through the low-pressure pressure reducing valve 42, and is also respectively connected with the air inlet of the pilot pressure control valve 36 and the B port of the two-position two-way electromagnetic valve three 35; the A port of the two-position two-way electromagnetic valve four 37, the A port of the two-position two-way electromagnetic valve five 39 and the A port of the two-position two-way electromagnetic valve one 41 are communicated with each other and connected with the control air port of the pilot pressure control valve 36; the air outlet of the pilot pressure control valve 36 is connected with the B port of the two-position two-way electromagnetic valve two 34; the liquid-air mixed cylinder 33 is provided with hydraulic oil in the oil cavity and air in the air cavity, and the air cavity air port of the liquid-air mixed cylinder 33 is connected with the A port of the two-position two-way electromagnetic valve two 34 and the A port of the two-position two-way electromagnetic valve three 35; the high-pressure hydraulic cylinder 32 is provided with hydraulic oil in the rodless cavity, the rodless cavity oil port of the high-pressure hydraulic cylinder 32 is connected with the oil cavity oil port of the liquid-air mixed cylinder 33, the rod cavity oil port of the high-pressure hydraulic cylinder 32 is communicated with the external atmosphere, and the piston rods of the high-pressure hydraulic cylinder 32 and the lifting hydraulic cylinder 31 are coaxially arranged and fixedly connected at the end portions of the piston rods.
[0027] The controller 9 is connected with the electromagnetic proportional valve 11 through the proportional amplifier 10, and the controller 9 is also connected with the comparator 8, the horizontal inclination sensor, the flow sensor one 29, the flow sensor two 30, the three-position four-way reversing valve one 13, the three-position four-way reversing valve two 26, the pneumatic electromagnetic valve two 46, the pneumatic electromagnetic valve one 43, the two-position two-way electromagnetic valve three 35, the two-position two-way electromagnetic valve two 34, the two-position two-way electromagnetic valve four 37, the two-position two-way electromagnetic valve five 39, the two-position two-way electromagnetic valve one 41, the stop valve 12 and the engine 1.
[0028] In order to avoid impurities from entering the system and affecting the normal operation of the hydraulic elements, the leveling mechanism further comprises the filter one 3 which is connected in series on the oil suction pipeline of the leveling drive pump 2; the lifting mechanism further comprises the filter two 21 which is connected in series on the oil suction pipeline of the lifting drive pump 20.
[0029] As a preferred, the controller 9 is a PLC controller.
[0030] As a preferred, the three-position four-way reversing valve 13 is electrically operated in the left position, the oil passage between the P port and the A port is communicated, the oil passage between the T port and the B port is communicated, is not electrically operated in the middle position, the A port and the B port are both cut off, the oil passage between the P port and the T port is communicated, is electrically operated in the right position, the oil passage between the P port and the B port is communicated, the oil passage between the A port and the T port is communicated.
[0031] As a preferred, the three-position four-way reversing valve 26 is H-type middle position function. The three-position four-way reversing valve 26 is electrically operated in the left position, the oil passage between the P port and the A port is communicated, the oil passage between the T port and the B port is communicated, is not electrically operated in the middle position, the oil passage between the A port, the B port, the P port and the T port is communicated, is electrically operated in the right position, the oil passage between the P port and the B port is communicated, the oil passage between the A port and the T port is communicated.
[0032] As a preferred, the electromagnetic proportional valve 11 is not electrically operated, the opening degree between the A port and the B port in the valve is 0, is electrically operated, with the increase of the current, the opening degree between the A port and the B port in the valve gradually increases.
[0033] As a preferred, the two-position two-way electromagnetic valve 35, the two-position two-way electromagnetic valve 34, the two-position two-way electromagnetic valve 37, the two-position two-way electromagnetic valve 39 and the two-position two-way electromagnetic valve 41 are electrically operated in the lower position, the gas passage between the A port and the B port is communicated, is not electrically operated in the upper position, the gas passage between the A port and the B port is disconnected.
[0034] As a preferred, the pneumatic electromagnetic valve 43 and the pneumatic electromagnetic valve 46 are both two-position two-way electromagnetic reversing valves, are electrically operated in the right position, the gas passage between the A port and the B port is communicated, is not electrically operated in the left position, the gas passage between the A port and the B port is disconnected.
[0035] In order to facilitate the sending of control signals, a control panel is further included, the control panel is connected with the controller 9, and is used for sending corresponding control signals to the controller 9 according to the control of the operator; a plurality of control buttons are arranged on the control panel, and are respectively a starting button, an adaptive leveling button, a machine lifting control mode button, an active lifting control button, a passive resistance type button, a large damping setting button, a medium damping setting button and a small damping setting button.
[0036] The initial moment, the initial state of the lifting hydraulic cylinder 31 is calibrated; the flow sensor one 29 is used to collect the flow signal one of the oil entering the rodless cavity of the lifting hydraulic cylinder 31 in real time, and is sent to the controller 9 in real time. The controller 9 obtains the oil volume passing through according to the flow signal one, and further matches the extension stroke of the piston rod of the lifting hydraulic cylinder 31 combined with the parameters such as the diameter of the rodless cavity, and then obtains the lifting height of the lifting hydraulic cylinder 31 based on the initial calibration value; the flow sensor two 30 is used to collect the flow signal two of the oil flowing out of the rodless cavity of the lifting hydraulic cylinder 31 in real time, and is sent to the controller 9 in real time. The controller 9 obtains the oil volume passing through according to the flow signal two, and further matches the retraction stroke of the piston rod of the lifting hydraulic cylinder 31 combined with the parameters such as the diameter of the rod cavity and the rod diameter ratio, and then obtains the lowering height of the lifting hydraulic cylinder 31 based on the initial calibration value; in this way, the controller 9 can conveniently determine the height of the connected implement according to the extension stroke and the retraction stroke.
[0037] When the start button is pressed, the controller 9 controls the engine 1 to work, and the engine 1 drives the leveling drive pump 2, the lifting drive pump 20 and the air pressure pump 44 to work; when the adaptive leveling button is pressed, the adaptive leveling mode signal is sent to the controller 9, and the controller 9 works in the implement adaptive leveling system working mode after receiving the adaptive leveling mode signal; when the active lifting control button is pressed, the active lifting control signal is sent to the controller 9, and the controller 9 works in the active lifting control mode after receiving the active lifting control signal; when the passive damping control button is pressed, the passive damping control signal is sent to the controller 9, and the controller 9 works in the passive damping mode after receiving the passive damping control signal;
[0038] When the horizontal inclination sensor monitors that the implement is inclined to one direction, the controller 9 controls the three-position four-way reversing valve one 13 to work in the left position, the output oil of the leveling driving pump 2 is supplied to the second cavity and the fourth cavity of the synchronization cylinder 14 through the oil path between the P port and the A port of the three-position four-way reversing valve one 13 respectively, the piston in the synchronization cylinder 14 is driven to move to the first cavity side, the oil in the first cavity and the third cavity of the synchronization cylinder 14 is synchronously flowed out and flows into the rod cavity of the leveling hydraulic cylinder one 18 and the rodless cavity of the leveling hydraulic cylinder two 19 respectively, at the same time, the oil in the rodless cavity of the leveling hydraulic cylinder one 18 and the rod cavity of the leveling hydraulic cylinder two 19 flows into the oil inlet of the cooler 5 through the oil path between the B port and the T port of the three-position four-way reversing valve one 13, and then flows back to the hydraulic oil tank 6 through the oil outlet of the cooler 5, so that the piston rod of the leveling hydraulic cylinder one 18 is extended and the piston rod of the leveling hydraulic cylinder two 19 is retracted, and then the leveling operation in one direction is carried out. The oil is supplied to the leveling hydraulic cylinder one 18 and the leveling hydraulic cylinder two 19 through the synchronization cylinder 14, which can ensure the synchronization of oil supply, and then can ensure that the speed stroke of the leveling hydraulic cylinder one 18 and the leveling hydraulic cylinder two 19 is basically the same, and the synchronization of extension and retraction can effectively increase the leveling speed.
[0039] When the horizontal inclination sensor monitors that the implement is inclined to the other direction, the controller 9 controls the three-position four-way reversing valve one 13 to work in the right position, so that the oil entering the P port of the three-position four-way reversing valve one 13 is supplied to the rodless cavity of the leveling hydraulic cylinder one 18 and the rod cavity of the leveling hydraulic cylinder two 19 through the B port respectively, at the same time, the oil in the rod cavity of the leveling hydraulic cylinder one 18 and the rodless cavity of the leveling hydraulic cylinder two 19 flows into the first cavity and the third cavity of the synchronization cylinder 14 respectively, the piston of the synchronization cylinder 14 is driven to move to the fourth cavity side, the oil in the second cavity and the fourth cavity of the synchronization cylinder 14 is synchronously flowed out and flows into the oil inlet of the cooler 5 through the oil path between the A port and the T port of the three-position four-way reversing valve one 13, and then flows back to the hydraulic oil tank 6 through the oil outlet of the cooler 5, and then the leveling operation in the other direction is carried out until the inclination angle reaches 0 degree. The oil flows back to the hydraulic oil tank 6 through the synchronization cylinder 14, which can ensure the synchronization of backflow, and then can ensure that the speed stroke of the leveling hydraulic cylinder one 18 and the leveling hydraulic cylinder two 19 is basically the same.
[0040] When the horizontal inclination sensor monitors that the implement reaches the horizontal state, the controller 9 controls the three-position four-way reversing valve one 13 to work in the middle position, so that the output oil of the leveling driving pump 2 directly flows back to the hydraulic oil tank 6 through the oil path between the P port and the T port of the three-position four-way reversing valve one 13;
[0041] In the process, the leveling hydraulic cylinder needs to act frequently, so the oil temperature rises greatly. Therefore, the cooling of the hydraulic oil can be effectively carried out through the setting of the stop valve 12, the electromagnetic proportional valve 11 and the cooler 5 in the servo oil cooling circuit. The oil temperature sensor 7 is used to collect the actual temperature signal of the hydraulic oil in the oil tank 6 in real time and send it to the comparator 8 in real time. The comparator 8 is used to compare the actual temperature signal with the preset set temperature signal. When the actual temperature signal is greater than or equal to the set temperature signal, a high temperature signal is sent to the controller 9. After the controller 9 receives the high temperature signal, the stop valve 12 is opened, and the output electric signal of the proportional amplifier 10 is increased to control the opening of the electromagnetic proportional valve 11, so that the cooling water supplied by the cooling water source enters the cooler 5 through the electromagnetic proportional valve 11 at a large flow rate, thereby increasing the flow rate of the cooling water and enhancing the cooling capacity to cool the return oil.
[0042] Because the one-way valve one 15 and the one-way valve two 16 are arranged, when the leveling hydraulic cylinder one 18 has reached the maximum stroke and the leveling hydraulic cylinder two 19 has not reached the maximum stroke, the higher pressure established in the leveling hydraulic cylinder one 18 subsequently can be discharged into the hydraulic oil tank 6 through the pressure relief branch of the one-way valve one 15 and the overflow valve 17. Similarly, when the leveling hydraulic cylinder two 19 has reached the maximum stroke and the leveling hydraulic cylinder one 18 has not reached the maximum stroke, the higher pressure established in the leveling hydraulic cylinder two 19 subsequently can be discharged into the hydraulic oil tank 6 through the pressure relief branch of the one-way valve two 16 and the overflow valve 17.
[0043] The controller 9 controls the pneumatic electromagnetic valve two 46 to work in the right position by being powered on, so that the air path between the A port and the B port is connected. At the same time, the two-position two-way electromagnetic valve 35 is controlled to work in the lower position by being powered on, so that the air path between the A port and the B port is connected. The pneumatic electromagnetic valve one 43 is controlled to work in the right position by being powered on, so that the air path between the A port and the B port is connected. The two-position two-way electromagnetic valve two 34 is controlled to work in the upper position by not being powered on, so that the air path between the A port and the B port is not connected. The two-position two-way electromagnetic valve three 35 is controlled to work in the lower position by being powered on, so that the air path between the A port and the B port is connected, thereby ensuring that the high-pressure gas output by the gas pressure pump 44 is directly discharged into the external atmosphere. At the same time, it is convenient to unload the gas in the gas cavity of the liquid-gas mixing cylinder 33.
[0044] Meanwhile, the controller 9 controls the three-position four-way directional valve two 26 to work in the left position or the right position. When the three-position four-way directional valve two 26 is in the left position, the output oil of the lifting driving pump 20 is output through the oil path between the P port and the A port of the three-position four-way directional valve two 26, and sequentially flows through the one-way valve six 27, the speed regulating valve 28, the flow sensor one 29 and the one-way valve three 23, and then enters the rodless cavity of the lifting hydraulic cylinder 31, so as to push the piston rod of the lifting hydraulic cylinder 31 to extend outward, so as to realize the action of height lifting of the agricultural implement. When the three-position four-way directional valve two 26 is in the right position, the output oil of the lifting driving pump 20 is supplied to the rod cavity of the lifting hydraulic cylinder 31 through the oil path between the P port and the B port of the three-position four-way directional valve two 26, so as to make the piston rod of the lifting hydraulic cylinder 31 retract, and meanwhile, the oil discharged from the rodless cavity of the lifting hydraulic cylinder 31 sequentially flows through the one-way valve five 25, the speed regulating valve 28, the flow sensor two 30 and the one-way valve four 24, and then flows into the A port of the three-position four-way directional valve two 26, and then flows back to the hydraulic oil tank 6 through the T port of the three-position four-way directional valve two 26.
[0045] In the process, the action speed of the lifting hydraulic cylinder 31 can be controlled through the opening degree adjustment of the speed regulating valve 28, that is, the sensitivity of the lifting mechanism of the agricultural implement is adjusted. When the opening degree of the speed regulating valve 28 is 0, the lifting hydraulic cylinder 31 can be locked to prevent it from floating up and down, so as to effectively ensure the working quality of the agricultural implement at a specific height.
[0046] The controller 9 controls the three-position four-way directional valve two 26 to work in the neutral position, and the oil discharged by the lifting drive pump 20 flows into the hydraulic oil tank 6 through the passage between the P port and the T port of the three-position four-way directional valve two 26, so as to unload the system. At the same time, the two-position two-way electromagnetic valve two 34 is controlled to work in the upper position, so that the air passage between the A port and the B port is not connected, the two-position two-way electromagnetic valve three 35 is controlled to work in the upper position, so that the air passage between the A port and the B port is not connected, and the pneumatic electromagnetic valve two 46 is controlled to work in the right position, so that the air passage between the A port and the B port is connected, so as to unload the pneumatic pump 44. In this way, when the piston rod of the lifting hydraulic cylinder 31 extends, the piston rod of the high-pressure hydraulic cylinder 32 is pushed to retract, and the hydraulic oil in the rodless cavity of the high-pressure hydraulic cylinder 32 is pressed into the oil cavity of the hydraulic gas mixing cylinder 33, and then the gas in the gas cavity of the hydraulic gas mixing cylinder 33 is compressed by the piston inside the hydraulic gas mixing cylinder 33. When the extension stroke of the piston rod of the lifting hydraulic cylinder 31 is small, the gas is easy to be compressed, and the stiffness and damping are small. As the extension stroke of the piston rod of the lifting hydraulic cylinder 31 becomes larger, the pressure of the compressed gas becomes higher, and the stiffness and damping become larger, so that the gas is difficult to be compressed. Similarly, when the piston rod of the lifting hydraulic cylinder 31 retracts, the piston rod of the high-pressure hydraulic cylinder 32 is extended, and the hydraulic oil in the oil cavity of the hydraulic gas mixing cylinder 33 is sucked into the rodless cavity of the high-pressure hydraulic cylinder 32, and the pressure in the gas cavity of the hydraulic gas mixing cylinder 33 is reduced. When the retraction stroke of the lifting hydraulic cylinder 31 is small, the gas cavity of the hydraulic gas mixing cylinder 33 is easy to be expanded, and the stiffness and damping are small. As the retraction stroke of the hydraulic cylinder 31 becomes larger, the gas cavity of the hydraulic gas mixing cylinder 33 is difficult to be further expanded, and the stiffness and damping become larger. In this way, when the tractor runs on uneven road, it can be ensured that the agricultural implement will not be greatly inclined and swung or up and down floated with the tractor, so as to effectively ensure the working quality of the agricultural implement.
[0047] In passive damping mode, the damping of the liquid-gas hybrid cylinder 33 can be set. When the large-damping setting button is pressed, the controller 9 controls the two-position two-way electromagnetic valve two 34 to be powered to work in the lower position, so that the gas path between its A port and B port is connected, and controls the two-position two-way electromagnetic valve three 35 to be powered to work in the upper position, so that the gas path between its A port and B port is not connected; controls the pneumatic electromagnetic valve one 43 to be powered to work in the right position, so that the gas path between its A port and B port is connected, and controls the pneumatic electromagnetic valve two 46 to be powered to work in the left position, so that the gas path between its A port and B port is not connected. The high-pressure outlet of the gas pressure pump 44 passes through the pneumatic electromagnetic valve one 43 to the high-pressure reducing valve 38, the medium-pressure reducing valve 40, the low-pressure reducing valve 42 and the inlet of the pilot pressure control valve 36, respectively; the controller 9 controls the two-position two-way electromagnetic valve four 37 to be powered to work in the lower position, so that the gas path between its A port and B port is connected, at the same time, controls the two-position two-way electromagnetic valve five 39 to be powered to work in the upper position, so that the gas path between its A port and B port is not connected, and controls the two-position two-way electromagnetic valve one 41 to be powered to work in the upper position, so that the gas path between its A port and B port is not connected; when the two-position two-way electromagnetic valve four 37 is connected, and the two-position two-way electromagnetic valve five 39 and the two-position two-way electromagnetic valve one 41 are disconnected, the set pressure of the pilot pressure control valve 36 is the highest, in this state, the high-pressure gas output by the gas pressure pump 44 passes through the gas path between the A port and the B port of the pneumatic electromagnetic valve one 43, the pilot pressure control valve 36 and the gas path between the A port and the B port of the two-position two-way electromagnetic valve two 34 in turn, and is injected into the air chamber of the liquid-gas hybrid cylinder 33, which can ensure that the stiffness damping of the liquid-gas hybrid cylinder 33 is the largest; when the medium-damping setting button is pressed, the controller 9 controls the two-position two-way electromagnetic valve two 34 to be powered to work in the lower position, so that the gas path between its A port and B port is connected, and controls the two-position two-way electromagnetic valve three 35 to be powered to work in the upper position, so that the gas path between its A port and B port is not connected; controls the pneumatic electromagnetic valve one 43 to be powered to work in the right position, so that the gas path between its A port and B port is connected, and controls the pneumatic electromagnetic valve two 46 to be powered to work in the left position, so that the gas path between its A port and B port is not connected.The high-pressure outlet of the air pressure pump 44 is connected to the inlet of the high-pressure pressure-reducing valve 38, the medium-pressure pressure-reducing valve 40, the low-pressure pressure-reducing valve 42 and the pilot pressure control valve 36 through the pneumatic electromagnetic valve 43; the controller 9 controls the two-position two-way electromagnetic valve 39 to be electrified and work in the lower position, so that the air path between the A port and the B port is connected, at the same time, controls the two-position two-way electromagnetic valve 37 to be de-electrified and work in the upper position, so that the air path between the A port and the B port is not connected, and controls the two-position two-way electromagnetic valve 41 to be de-electrified and work in the upper position, so that the air path between the A port and the B port is not connected; when the two-position two-way electromagnetic valve 39 is connected and the two-position two-way electromagnetic valve 37 and the two-position two-way electromagnetic valve 41 are disconnected, the set pressure of the pilot pressure control valve 36 is medium, in this state, the high-pressure gas output by the air pressure pump 44 is injected into the air cavity of the liquid-gas mixing cylinder 33 through the air path between the A port and the B port of the pneumatic electromagnetic valve 43, the pilot pressure control valve 36 and the air path between the A port and the B port of the two-position two-way electromagnetic valve 34 in turn, which can ensure that the stiffness and damping of the liquid-gas mixing cylinder 33 are moderate; when the small-damping setting button is pressed, the controller 9 controls the two-position two-way electromagnetic valve 34 to be electrified and work in the lower position, so that the air path between the A port and the B port is connected, and controls the two-position two-way electromagnetic valve 35 to be de-electrified and work in the upper position, so that the air path between the A port and the B port is not connected; the pneumatic electromagnetic valve 43 is controlled to be electrified and work in the right position, so that the air path between the A port and the B port is connected, and the pneumatic electromagnetic valve 46 is controlled to be de-electrified and work in the left position, so that the air path between the A port and the B port is not connected. The high-pressure outlet of the air pressure pump 44 is connected to the inlet of the high-pressure pressure-reducing valve 38, the medium-pressure pressure-reducing valve 40, the low-pressure pressure-reducing valve 42 and the pilot pressure control valve 36 through the pneumatic electromagnetic valve 43; the controller 9 controls the two-position two-way electromagnetic valve 41 to be electrified and work in the lower position, so that the air path between the A port and the B port is connected, at the same time, controls the two-position two-way electromagnetic valve 37 to be de-electrified and work in the upper position, so that the air path between the A port and the B port is not connected, and controls the two-position two-way electromagnetic valve 39 to be de-electrified and work in the upper position, so that the air path between the A port and the B port is not connected; when the two-position two-way electromagnetic valve 41 is connected and the two-position two-way electromagnetic valve 37 and the two-position two-way electromagnetic valve 39 are disconnected, the set pressure of the pilot pressure control valve 36 is minimum, in this state, the high-pressure gas output by the air pressure pump 44 is injected into the air cavity of the liquid-gas mixing cylinder 33 through the air path between the A port and the B port of the pneumatic electromagnetic valve 43, the pilot pressure control valve 36 and the air path between the A port and the B port of the two-position two-way electromagnetic valve 34 in turn, which can ensure that the stiffness and damping of the liquid-gas mixing cylinder 33 are minimum.
[0048] In the present application, the rod cavity of the leveling hydraulic cylinder one and the rodless cavity of the leveling hydraulic cylinder two are connected with the first cavity oil port and the third cavity oil port of the synchronous cylinder respectively, and the second cavity oil port and the fourth cavity oil port of the synchronous cylinder are connected with the A port of the three-position four-way reversing valve one, so that the synchronization of the oil supply process to the rod cavity of the leveling hydraulic cylinder one and the rodless cavity of the leveling hydraulic cylinder two can be ensured, and the synchronization of the oil discharge process in the rod cavity of the leveling hydraulic cylinder one and the rodless cavity of the leveling hydraulic cylinder two can also be ensured, thereby the action speed and stroke of the piston rod of the leveling hydraulic cylinder one and the piston rod of the leveling hydraulic cylinder two are basically the same, and the synchronization mode of one piston rod extending and the other piston rod retracting can effectively increase the leveling speed. The one-way valve one is connected between the rod cavity of the leveling hydraulic cylinder one and the overflow valve, so that when the leveling hydraulic cylinder one reaches the maximum stroke and the leveling hydraulic cylinder two has not reached the maximum stroke, the high-pressure oil generated subsequently in the leveling hydraulic cylinder one is discharged into the hydraulic oil tank through the one-way valve one and the overflow valve, thereby the synchronization of the actions of the leveling hydraulic cylinder one and the leveling hydraulic cylinder two can be effectively ensured. The one-way valve two is connected between the rod cavity of the leveling hydraulic cylinder two and the overflow valve, so that when the leveling hydraulic cylinder two reaches the maximum stroke and the leveling hydraulic cylinder one has not reached the maximum stroke, the high-pressure oil generated subsequently in the leveling hydraulic cylinder two is discharged into the hydraulic oil tank through the one-way valve two and the overflow valve, thereby the synchronization of the actions of the leveling hydraulic cylinder one and the leveling hydraulic cylinder two can be effectively ensured. The cooler is arranged, so that when the leveling hydraulic cylinder frequently acts and the oil temperature rises greatly, the hydraulic oil can be effectively cooled. The oil temperature sensor is arranged, so that the actual oil temperature signal of the hydraulic oil tank can be collected in real time, and the actual oil temperature signal can be compared with the set oil temperature value by the comparator, so that when the actual oil temperature is higher than the set value, a high-temperature signal is sent to the controller, so that the controller automatically connects the cooling water source of the cooler, thereby realizing the automation of the cooling process. The bridge circuit is arranged, so that the action speed of the lowering hydraulic cylinder can be controlled by the opening degree of the speed regulating valve, the sensitivity of the lifting mechanism can be adjusted, the lowering hydraulic cylinder can be locked by the opening degree of the speed regulating valve being 0, thereby the up-and-down floating of the lifting mechanism can be prevented, and the inclination swing or up-and-down floating of the agricultural implement can be effectively avoided. The piston rod of the high-pressure cylinder is coaxially and fixedly connected with the piston rod of the lifting hydraulic cylinder, the rodless cavity of the high-pressure cylinder is connected with the oil cavity of the liquid-gas mixing cylinder, and the gas cavity of the liquid-gas mixing cylinder is connected with the A ports of the two-position two-way electromagnetic valves two and three, so that the damping level in the passive damping mode can be conveniently and automatically set, and the lifting mechanism can work in the passive damping mode that has been set, thereby the inclination swing or up-and-down floating of the agricultural implement with the tractor can be effectively reduced, and the working quality of the agricultural implement can be effectively ensured.By setting high pressure reducing valve, medium pressure reducing valve and low pressure reducing valve at the same time, and making them connect with the control gas port of the pilot pressure control valve through two-position two-way electromagnetic valve four, two-position two-way electromagnetic valve five and two-position two-way electromagnetic valve one respectively, the control pressure of the pilot pressure control valve can be conveniently controlled. In this way, three kinds of adjustable dampings can be conveniently set, and then various machine tool operation requirements can be met.
[0049] The application can automatically realize the lifting and leveling process of the machine tool, and effectively improve the quality of the operation. For the lifting mechanism, in the traditional technical solution, the cost of the means for determining the position of the hydraulic cylinder by using the bidirectional flow sensor is extremely expensive. In the application, the technical means of bridge circuit plus two conventional flow sensors is creatively adopted, which can realize bidirectional monitoring of flow and greatly reduce the cost, so that the bidirectional flow monitoring process is easier to realize. For the leveling mechanism, two leveling hydraulic cylinders are arranged, and the action modes of the piston rods thereof are synchronous and reverse, which can effectively improve the leveling efficiency. For the problem of large heat generation of the leveling mechanism, the cooling mechanism is arranged, which can ensure that the temperature of the hydraulic oil can be maintained within the appropriate range. For the adjustable damping mechanism, it can have three damping levels, which can meet the use requirements of different agricultural machine tools, and can ensure that the agricultural machine tool will not tilt and swing or float up and down with the tractor when the tractor is running on uneven road, so as to effectively ensure the operation quality of the agricultural machine tool.
Claims
1. An electro-hydraulic profiling system comprising an engine (1), a hydraulic tank (6), a levelling mechanism, a cooling mechanism, a lifting mechanism, an adjustable damping mechanism and a controller (9); characterised in that ； The leveling mechanism is composed of a leveling drive pump (2), a three-position four-way reversing valve (13), a safety valve (4), a leveling hydraulic cylinder (18), a leveling hydraulic cylinder (19), a synchronous cylinder (14), a one-way valve (15), a one-way valve (16), an overflow valve (17) and a horizontal inclination sensor; the leveling drive pump (2) is coaxially connected with the engine (1), the oil suction port of the leveling drive pump (2) is connected with the hydraulic oil tank (6) through an oil suction pipeline, the oil discharge port of the leveling drive pump (2) is connected with the P port of the three-position four-way reversing valve (13), and the three-position four-way reversing valve (13) is also connected with the hydraulic oil tank (6) through the safety valve (4); the B port of the three-position four-way reversing valve (13) is respectively connected with the rodless cavity oil port of the leveling hydraulic cylinder (18) and the rod cavity oil port of the leveling hydraulic cylinder (19), and the A port thereof is respectively connected with the oil port of the second cavity and the oil port of the fourth cavity of the synchronous cylinder (14); the oil port of the first cavity and the oil port of the third cavity of the synchronous cylinder (14) are respectively connected with the rod cavity oil port of the leveling hydraulic cylinder (18) and the rodless cavity oil port of the leveling hydraulic cylinder (19); the rod cavity oil port of the leveling hydraulic cylinder (18) is connected with the oil inlet of the one-way valve (15), the rodless cavity oil port of the leveling hydraulic cylinder (19) is connected with the oil inlet of the one-way valve (16), and the oil outlets of the one-way valve (15) and the one-way valve (16) are both connected with the hydraulic oil tank (6) through the overflow valve (17); the leveling hydraulic cylinder (18) and the leveling hydraulic cylinder (19) are arranged correspondingly, one end of each of them is installed on the tractor frame, and the other end is installed on the agricultural implement, for realizing leveling operation in two opposite directions; the horizontal inclination sensor is installed on the agricultural implement; The cooling mechanism is composed of an electromagnetic proportional valve (11), a stop valve (12), a cooler (5), an oil temperature sensor (7) and a comparator (8); the B port of the electromagnetic proportional valve (11) is connected with a cold water source through the stop valve (12), the A port thereof is connected with the cooling liquid inlet of the cooler (5), the cooling liquid outlet of the cooler (5) is connected with a water collecting device; the oil inlet of the cooler (5) is connected with the T port of the three-position four-way reversing valve (13), and the oil outlet thereof is connected with the hydraulic oil tank (6); the oil temperature sensor (7) is installed in the hydraulic oil tank (6) and is connected with the comparator (8); The lifting mechanism is composed of a lifting driving pump (20), a safety valve two (22), a three-position four-way reversing valve two (26), a lifting hydraulic cylinder (31) and a bridge circuit; the lifting driving pump (20) is coaxially connected with the engine (1); the oil suction port of the lifting driving pump (20) is connected with the hydraulic oil tank (6) through an oil suction pipeline, and the oil discharge port is connected with the hydraulic oil tank (6) through the safety valve two (22), and is also connected with the P port of the three-position four-way reversing valve two (26); the B port of the three-position four-way reversing valve two (26) is connected with the rod cavity oil port of the lifting hydraulic cylinder (31), and the A port is connected with the rodless cavity oil port of the lifting hydraulic cylinder (31) through the bridge circuit; the piston rod of the lifting hydraulic cylinder (31) is connected with the agricultural implement, and is used for adjusting the height of the agricultural implement; the bridge circuit is composed of a speed regulating valve (28), a one-way valve six (27), a one-way valve five (25), a flow sensor one (29), a one-way valve three (23), a flow sensor two (30) and a one-way valve four (24); the oil inlet of the speed regulating valve (28) is respectively connected with the oil outlet of the one-way valve six (27) and the oil outlet of the one-way valve five (25); the oil outlet is divided into two paths, one path is connected with the oil inlet of the one-way valve three (23) through the flow sensor one (29), and the other path is connected with the oil inlet of the one-way valve four (24) through the flow sensor two (30); the oil outlet of the one-way valve four (24) is connected with the A port of the three-position four-way reversing valve two (26) and the oil inlet of the one-way valve six (27), and the oil outlet of the one-way valve three (23) is connected with the oil inlet of the one-way valve five (25) and the rodless cavity oil port of the lifting hydraulic cylinder (31); The adjustable damping mechanism is composed of an air pressure pump (44), an air pressure safety valve (45), a pneumatic electromagnetic valve I (43), a pneumatic electromagnetic valve II (46), a high-pressure pressure reducing valve (38), a two-position two-way electromagnetic valve IV (37), a medium-pressure pressure reducing valve (40), a two-position two-way electromagnetic valve V (39), a low-pressure pressure reducing valve (42), a two-position two-way electromagnetic valve I (41), a pilot pressure control valve (36), a two-position two-way electromagnetic valve III (35), a two-position two-way electromagnetic valve II (34), a liquid-air mixed cylinder (33) and a high-pressure hydraulic cylinder (32); the air pressure pump (44) is coaxially connected with the engine (1), the air outlet thereof is connected with the air pressure safety valve (45), and the air pressure pump (44) is further respectively connected with the A port of the pneumatic electromagnetic valve II (46) and the B port of the pneumatic electromagnetic valve I (43), the B port of the pneumatic electromagnetic valve II (46) is communicated with the external atmosphere, the A port of the pneumatic electromagnetic valve I (43) is connected with the B port of the two-position two-way electromagnetic valve IV (37) through the high-pressure pressure reducing valve (38), the A port of the pneumatic electromagnetic valve I (43) is further connected with the B port of the two-position two-way electromagnetic valve V (39) through the medium-pressure pressure reducing valve (40), the A port of the pneumatic electromagnetic valve I (43) is further connected with the B port of the two-position two-way electromagnetic valve I (41) through the low-pressure pressure reducing valve (42), the A port of the pneumatic electromagnetic valve I (43) is further respectively connected with the air inlet of the pilot pressure control valve (36) and the B port of the two-position two-way electromagnetic valve III (35), the A port of the two-position two-way electromagnetic valve IV (37), the A port of the two-position two-way electromagnetic valve V (39) and the A port of the two-position two-way electromagnetic valve I (41) are communicated with each other and connected with the control air port of the pilot pressure control valve (36), the air outlet of the pilot pressure control valve (36) is connected with the B port of the two-position two-way electromagnetic valve II (34), the oil cavity of the liquid-air mixed cylinder (33) is filled with hydraulic oil, the air cavity of the liquid-air mixed cylinder (33) is filled with air, and the air cavity air port of the liquid-air mixed cylinder (33) is connected with the A port of the two-position two-way electromagnetic valve II (34) and the A port of the two-position two-way electromagnetic valve III (35) at the same time, the rodless cavity of the high-pressure hydraulic cylinder (32) is filled with hydraulic oil, the rodless cavity oil port of the high-pressure hydraulic cylinder (32) is connected with the oil cavity oil port of the liquid-air mixed cylinder (33), the rod cavity oil port of the high-pressure hydraulic cylinder (32) is communicated with the external atmosphere, the piston rods of the high-pressure hydraulic cylinder (32) and the lifting hydraulic cylinder (31) are coaxially arranged, and the two piston rods are fixedly connected at the end portions. The controller (9) is connected with the electromagnetic proportional valve (11) through the proportional amplifier (10), and the controller (9) is further connected with the comparator (8), the horizontal inclination sensor, the flow sensor I (29), the flow sensor II (30), the three-position four-way directional valve I (13), the three-position four-way directional valve II (26), the pneumatic electromagnetic valve II (46), the pneumatic electromagnetic valve I (43), the two-position two-way electromagnetic valve III (35), the two-position two-way electromagnetic valve II (34), the two-position two-way electromagnetic valve IV (37), the two-position two-way electromagnetic valve V (39), the two-position two-way electromagnetic valve I (41), the stop valve (12) and the engine (1).
2. An electro-hydraulic profiling system according to claim 1, wherein, The leveling mechanism further comprises a filter I (3), and the filter I (3) is connected in series on the oil suction pipeline of the leveling driving pump (2); the lifting mechanism further comprises a filter II (21), and the filter II (21) is connected in series on the oil suction pipeline of the lifting driving pump (20).
3. An electro-hydraulic profiling system according to claim 1 or 2, characterized in that The controller (9) is a PLC controller.
4. An electro-hydraulic profiling system according to claim 3, wherein, When the three-position four-way directional valve one (13) is electrified and works in the left position, the oil passage between the P port and the A port is communicated, the oil passage between the T port and the B port is communicated, when the three-position four-way directional valve one (13) is not electrified and works in the middle position, the A port and the B port are both cut off, the oil passage between the P port and the T port is communicated, when the three-position four-way directional valve one (13) is electrified and works in the right position, the oil passage between the P port and the B port is communicated, the oil passage between the A port and the T port is communicated.
5. An electro-hydraulic profiling system according to claim 4, wherein, When the three-position four-way directional valve two (26) is electrified and works in the left position, the oil passage between the P port and the A port is communicated, the oil passage between the T port and the B port is communicated, when the three-position four-way directional valve two (26) is not electrified and works in the middle position, the oil passages between the A port, the B port, the P port and the T port are communicated with each other, when the three-position four-way directional valve two (26) is electrified and works in the right position, the oil passage between the P port and the B port is communicated, the oil passage between the A port and the T port is communicated.
6. An electro-hydraulic profiling system according to claim 5, wherein, When the electromagnetic proportional valve (11) is not electrified, the opening degree between the A port and the B port in the valve is 0, when the electromagnetic proportional valve (11) is electrified, with the increase of the current, the opening degree between the A port and the B port in the valve gradually increases.
7. An electro-hydraulic profiling system according to claim 6, wherein, The two-position two-way electromagnetic valve three (35), the two-position two-way electromagnetic valve two (34), the two-position two-way electromagnetic valve four (37), the two-position two-way electromagnetic valve five (39) and the two-position two-way electromagnetic valve one (41) are electrified and work in the lower position, the air passage between the A port and the B port is communicated, when the two-position two-way electromagnetic valve three (35), the two-position two-way electromagnetic valve two (34), the two-position two-way electromagnetic valve four (37), the two-position two-way electromagnetic valve five (39) and the two-position two-way electromagnetic valve one (41) are not electrified and work in the upper position, the air passage between the A port and the B port is disconnected.
8. An electro-hydraulic profiling system according to claim 7, wherein, The pneumatic electromagnetic valve one (43) and the pneumatic electromagnetic valve two (46) are both two-position two-way electromagnetic directional valves, when the pneumatic electromagnetic valve one (43) and the pneumatic electromagnetic valve two (46) are electrified and work in the right position, the air passage between the A port and the B port is communicated, when the pneumatic electromagnetic valve one (43) and the pneumatic electromagnetic valve two (46) are not electrified and work in the left position, the air passage between the A port and the B port is disconnected.
Citation Information
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