阅读说明：本技术 一种开沟定压电液仿形开沟系统及控制方法 (Ditching constant-pressure electro-hydraulic profiling ditching system and control method ) 是由 梁方 雷淇奥 王双双 李世伟 杨坤 郑思远 刘伟 余佳 于 2019-11-18 设计创作，主要内容包括：本发明公开了一种开沟定压电液仿形开沟系统及控制方法,包括安装在机架上的多组开沟镇压单体、液压工作站、液压-四杆仿形机构和压力传感器,以及控制器、变送器、电磁换向阀VY1、电磁换向阀VY2、溢流阀、先导型电液比例减压阀YV3及节流阀；以压力传感器采集的压力值作为反馈信号,通过与理想开沟压力值比较,在控制器内进行逻辑运算,输出电流信号以控制电磁换向阀与先导型电液比例减压阀,使得液压缸完成升高或降低的响应动作,从而实现开沟压力的恒定,克服了机械仿形中弹簧压力变化导致的开沟深度不一致性的问题,系统响应灵敏,控制精准。(The invention discloses a ditching constant-pressure electro-hydraulic profiling ditching system and a control method, which comprise a plurality of groups of ditching pressing monomers, a hydraulic workstation, a hydraulic-four-rod profiling mechanism and a pressure sensor which are arranged on a rack, as well as a controller, a transmitter, an electromagnetic directional valve VY1, an electromagnetic directional valve VY2, an overflow valve, a pilot-operated electro-hydraulic proportional pressure reducing valve YV3 and a throttle valve; the pressure value collected by the pressure sensor is used as a feedback signal, logical operation is carried out in the controller by comparing with an ideal ditching pressure value, and a current signal is output to control the electromagnetic directional valve and the pilot type electro-hydraulic proportional pressure reducing valve, so that the hydraulic cylinder completes the response action of rising or lowering, the ditching pressure is constant, the problem of inconsistency of ditching depth caused by spring pressure change in mechanical profiling is solved, the system response is sensitive, and the control is accurate.)

1. A constant-pressure electric-hydraulic ditching and profiling system comprises a plurality of ditching and pressing units arranged on a rack, wherein each ditching and pressing unit comprises a double-disc ditcher (1) and a pressing wheel (17), and the double-disc ditcher (1) and the pressing wheel are both arranged on the rack (18) through a fixed seat and are arranged in a front-back opposite corresponding manner; the method is characterized in that: the hydraulic working station comprises an oil tank (11) and a motor (15) fixed on the oil tank (11), the hydraulic-four-bar copying mechanism comprises two sets of four-bar mechanisms (3) which are vertically and correspondingly arranged in parallel and a hydraulic cylinder (4) arranged between the two sets of four-bar mechanisms (3), wherein one side of each set of four-bar mechanism (3) is connected with the oil tank (11), and the other side of each set of four-bar mechanism (3) is connected with a rack (18);

the device also comprises a controller (12), a transmitter (13), an electromagnetic directional valve VY1(6), an electromagnetic directional valve VY2(5), an overflow valve (10), a pilot type electro-hydraulic proportional pressure reducing valve YV3(7) and a throttle valve (8); an oil inlet B1 of a left cavity of the hydraulic cylinder (4) is connected with an oil outlet B2 of an electromagnetic directional valve YV1(6), an oil inlet A1 of a right cavity of the hydraulic cylinder (4) is connected with an oil outlet A3 of an electromagnetic directional valve YV2(5), an oil outlet B4 of a pilot-operated electro-hydraulic proportional pressure reducing valve YV3(7) is connected with an oil inlet A2 of the electromagnetic directional valve YV1(6), an oil return port C2 of the electromagnetic directional valve YV1(6), an oil return port C3 of the electromagnetic directional valve YV2(5) and an oil return port C4 of the pilot-operated electro-hydraulic proportional pressure reducing valve YV3(7) are communicated with an oil tank (11), a first variable pump (9) is connected with an oil outlet A4 of the pilot-operated electro-hydraulic proportional pressure reducing valve YV3(7) through a throttle valve (8), an oil inlet A5 of an overflow valve (10) is connected with an oil outlet of the first variable pump (9), and an oil outlet B5 of the overflow valve; the output end of the pressure sensor (2) is connected with the pressure signal input end of a transmitter (13), the current signal output end of the transmitter (13) is connected with the input end of a controller (12), and the control signal output end of the controller (12) is connected with the control signal input ends of an electromagnetic directional valve YV1(6), an electromagnetic directional valve YV2(5) and a pilot-operated electro-hydraulic proportional pressure reducing valve YV3(7) through a current amplifier (14).

2. The trenching, constant-pressure, electro-hydraulic profiling trenching system of claim 1, wherein: one end of the hydraulic cylinder (4) is connected with a lateral transverse connecting shaft (19) on one side of the upper four-bar mechanism (3), the other end of the hydraulic cylinder (4) is connected with a middle transverse connecting shaft (20) fixed on the lower four-bar mechanism (3), and meanwhile, the middle transverse connecting shaft (20) is fixed at the middle point of the lower four-bar mechanism (3).

3. The trenching, constant-pressure, electro-hydraulic profiling trenching system of claim 1, wherein: the fixing seat comprises a supporting plate (104), a hollow fixing sleeve (105) arranged in the middle of the surface of the supporting plate (104) and a long handle (101) with the top end inserted into a hollow cavity of the hollow fixing sleeve (105), the top surface of the hollow fixing sleeve (105) is provided with a fixing hole, the fixing hole (106) is communicated with the hollow cavity, the pressure sensor (2) is inserted from the fixing hole (106) until the external thread at the lower part of the pressure sensor (2) is connected with the internal thread at the upper part of the long handle (101), the protective cover (102) is inserted into a U-shaped groove on the top surface of the hollow fixed sleeve (105) until the external thread on the upper part of the pressure sensor (2) is clamped at the U-shaped notch of the protective cover (102), the bolt (103) is arranged at the upper external thread of the pressure sensor (2) until the bolt (103) abuts against the protective cover (102), and the pressure sensor (2), the long handle (101) and the protective cover (102) are on the same axis.

4. The trenching, constant-pressure, electro-hydraulic profiling trenching system of claim 2, wherein: and two ends of the hydraulic cylinder (4) are matched with a lateral transverse connecting shaft (19) and a middle transverse connecting shaft (20) on one side of the upper four-bar mechanism (3) through shaft holes.

5. A control method of the ditching constant-pressure electro-hydraulic profiling ditching system as claimed in claim 1, characterized in that: the control method comprises the following steps:

firstly, determining an ideal ditching pressure value F required by ditching depth₀And the ideal ditching pressure value F is set₀Inputting the ditching pressure error value E and the ditching pressure error value E into a controller (12), and starting a motor (15);

when the ditching ground surface is flat, the actual ditching pressure is constant, namely | F₁-F₀Controlling the left access circuit of the electromagnetic directional valve VY1(6), the electromagnetic directional valve VY2(5) and the pilot-operated electro-hydraulic proportional pressure reducing valve YV3(7) to be E, wherein the oil path is blocked, and the oil pumped by the first variable pump (9) flows back to the oil tank (11) from the oil port B5 through the overflow valve (10);

when the surface is raised, the actual ditching pressure is increased, i.e. | F₁-F₀I > E and F₁-F₀The right position of the electromagnetic directional valve VY1(6), the electromagnetic directional valve VY2(5) and the pilot-operated type electro-hydraulic proportional pressure reducing valve YV3(7) is controlled to be connected into a circuit, the oil circuit is connected, the pressure value of the hydraulic cylinder (4) is larger than the preset pressure value of the pilot-operated type electro-hydraulic proportional pressure reducing valve YV3(7), oil flows out from an oil port B1, the pilot valve of the pilot-operated type electro-hydraulic proportional pressure reducing valve YV3(7) is opened, the oil at the outlet of the pilot-operated type electro-hydraulic proportional pressure reducing valve YV3(7) flows back to the oil tank (11) from the oil port C4 through the pilot valve of the pilot-operated type electro-hydraulic proportional pressure reducing valve YV3(7), the hydraulic cylinder (4) is contracted, the double-disc furrow opener (1) is lifted until₀；

When the surface is sunken, the actual ditching pressure is reduced, i.e. | F₁-F₀I > E and F₁-F₀Less than or equal to 0, the right positions of the electromagnetic directional valve VY1(6), the electromagnetic directional valve VY2(5) and the pilot type electro-hydraulic proportional pressure reducing valve YV3(7) are connected into a circuit, an oil circuit is connected, the pressure value of the hydraulic cylinder (4) is smaller than the pressure preset value of the pilot type electro-hydraulic proportional pressure reducing valve YV3(7), oil flows into the hydraulic cylinder (4) from the oil port B1, the hydraulic cylinder (4) extends, and the double-disc furrow opener (1) is arranged below the hydraulic cylinder (4)And (5) reducing until the ditching pressure is recovered to the set value.

6. The control method of the ditching constant-pressure electro-hydraulic profiling ditching system of claim 5, wherein: when the motor (15) is turned off and the first variable pump (9) stops working, the electromagnetic directional valve YV2(5) and the electromagnetic directional valve YV1(6) are communicated at the right position, and the double-disc furrow opener (1) is manually lifted.

Technical Field

The invention belongs to the technical field of agricultural machinery, and particularly relates to a constant-pressure electric-hydraulic profiling ditching system for ditching and a control method.

Background

The sowing depth consistency is one of important indexes for measuring the performance of the sowing machine, and over-shallow or over-deep sowing not only affects the germination rate of seeds, but also causes inconsistent plant heights, and further affects the quality of subsequent mechanical operations such as plant protection, harvesting and the like. In order to realize constant sowing depth, a copying system of the furrow opener is a key.

The main profiling mechanisms at present comprise mechanical profiling and electro-hydraulic (pneumatic) profiling. Mechanical profiling usually utilizes spring deformation, and adopts a single-point single-rod hinge type profiling mechanism, a parallel four-rod profiling mechanism and a multi-rod two-degree-of-freedom profiling mechanism to realize a profiling function, wherein the parallel four-rod profiling mechanism can ensure that a furrow opener is always vertical to the ground surface in the profiling process, and the application is widest. But the parallel four-bar copying mechanism based on the spring can not ensure that the ditching depth is completely consistent. This is because, under ideal soil conditions (consistent physical parameters of the soil), the vertical pressure of ditching corresponding to a certain ditching depth is constant, and in the profiling process, along with the protrusion and depression of the earth's surface, the spring will compress and extend, and the vertical pressure of the spring on the ditcher will also change, resulting in a change in the ditching depth.

Disclosure of Invention

The invention aims to provide a constant-pressure ditching electro-hydraulic profiling ditching system and a control method for realizing constant ditching pressure aiming at the defects of the technology, and solves the problem of inconsistent ditching depth caused by spring pressure change in mechanical profiling.

In order to achieve the purpose, the ditching constant-pressure electro-hydraulic profiling ditching system comprises a plurality of groups of ditching and pressing monomers which are arranged on a rack, wherein each group of ditching and pressing monomers comprises a double-disc ditcher and a pressing wheel, and the double-disc ditcher and the pressing wheel are arranged on the rack through a fixed seat and are arranged in a front-back opposite corresponding manner; the hydraulic working station comprises an oil tank and a motor fixed on the oil tank, the hydraulic-four-bar copying mechanism comprises two sets of four-bar mechanisms which are vertically and correspondingly arranged in parallel and a hydraulic cylinder arranged between the two sets of four-bar mechanisms, one side of each set of four-bar mechanism is connected with the oil tank, and the other side of each set of four-bar mechanism is connected with the rack;

the device also comprises a controller, a transmitter, an electromagnetic directional valve VY1, an electromagnetic directional valve VY2, an overflow valve, a pilot type electro-hydraulic proportional pressure reducing valve YV3 and a throttle valve; an oil inlet B1 of a left cavity of the hydraulic cylinder is connected with an oil outlet B2 of an electromagnetic directional valve YV1, an oil inlet A1 of a right cavity of the hydraulic cylinder is connected with an oil outlet A3 of an electromagnetic directional valve YV2, an oil outlet B4 of a pilot-operated electro-hydraulic proportional pressure reducing valve YV3 is connected with an oil inlet A2 of an electromagnetic directional valve YV1, an oil return port C2 of the electromagnetic directional valve YV1, an oil return port C3 of the electromagnetic directional valve YV2 and an oil return port C4 of the pilot-operated electro-hydraulic proportional pressure reducing valve YV3 are communicated with an oil tank, a first variable pump is connected with an oil outlet A4 of the pilot-operated electro-hydraulic proportional pressure reducing valve YV3 through a throttle valve, an oil inlet A5 of an overflow valve is connected with a first variable pump, and an; the output end of the pressure sensor is connected with the pressure signal input end of the transmitter, the current signal output end of the transmitter is connected with the input end of the controller, and the control signal output end of the controller is connected with the control signal input ends of the electromagnetic directional valve YV1, the electromagnetic directional valve YV2 and the pilot-operated type electro-hydraulic proportional pressure reducing valve YV3 through the current amplifier.

Furthermore, one end of the hydraulic cylinder is connected with a lateral transverse connecting shaft on one side of the upper four-bar mechanism, the other end of the hydraulic cylinder is connected with a middle transverse connecting shaft fixed on the lower four-bar mechanism, and meanwhile, the middle transverse connecting shaft is fixed at the midpoint of the lower four-bar mechanism.

Further, the fixing seat comprises a supporting plate, a hollow fixing sleeve arranged in the middle of the surface of the supporting plate and a long handle inserted into a hollow cavity of the hollow fixing sleeve from the top end, a fixing hole is formed in the top surface of the hollow fixing sleeve, the fixing hole is communicated with the hollow cavity, the pressure sensor is inserted into the fixing hole until the external thread on the lower portion of the pressure sensor is connected with the internal thread on the upper portion of the long handle, the protective cover is inserted into a U-shaped groove in the top surface of the hollow fixing sleeve until the external thread on the upper portion of the pressure sensor is clamped at a U-shaped notch of the protective cover, the bolt is installed at the external thread on the upper portion of the pressure sensor until the bolt abuts.

Furthermore, two ends of the hydraulic cylinder are matched with the lateral transverse connecting shaft and the middle transverse connecting shaft on one side of the upper four-bar mechanism through shaft holes.

The control method of the ditching constant-pressure electro-hydraulic profiling ditching system is also provided:

firstly, determining an ideal ditching pressure value F required by ditching depth₀And the ideal ditching pressure value F is set₀And the ditching pressure error value E are input into the controller 12, and the motor is started;

when the ditching ground surface is flat, the actual ditching pressure is constant, namely | F₁-F₀Controlling a left access circuit of the electromagnetic directional valve VY1, the electromagnetic directional valve VY2 and the pilot-operated electro-hydraulic proportional pressure reducing valve YV3 to be disconnected with an oil path, and enabling oil pumped out by the first variable pump to flow back to an oil tank from an oil port B5 through an overflow valve;

when the surface is raised, the actual ditching pressure is increased, i.e. | F₁-F₀I > E and F₁-F₀When the pressure value of the hydraulic cylinder is larger than the preset pressure value of the pilot type electro-hydraulic proportional pressure reducing valve YV3, the oil flows out from an oil port B1, a pilot valve of the pilot type electro-hydraulic proportional pressure reducing valve YV3 is opened, the oil at the outlet of the pilot type electro-hydraulic proportional pressure reducing valve YV3 flows back to the oil tank from an oil port C4 through the pilot valve of the pilot type electro-hydraulic proportional pressure reducing valve YV3, the hydraulic cylinder contracts, the double-disc furrow opener is lifted until the actual ditching pressure is restored to the ideal ditching pressure value F₀；

When the surface is sunken, the actual ditching pressure is reduced, i.e. | F₁-F₀I > E and F₁-F₀And (3) the hydraulic oil flows into the hydraulic cylinder from the oil port B1, the hydraulic cylinder extends, and the double-disc opener descends until the ditching pressure is recovered to a set value, wherein the electromagnetic directional valve VY1, the electromagnetic directional valve VY2 and the pilot-operated electro-hydraulic proportional pressure reducing valve YV3 are connected to the circuit at the right position, the oil circuit is connected, the pressure value of the hydraulic cylinder is smaller than the pressure preset value of the pilot-operated electro-hydraulic proportional pressure reducing valve YV3 at the moment, and the oil flows into the hydraulic cylinder from.

Further, when the motor is turned off and the first variable pump stops working, the electromagnetic directional valve YV2 and the electromagnetic directional valve YV1 are switched on at the right position, and the double-disc furrow opener is manually lifted.

Compared with the prior art, the invention has the following advantages: the hydraulic profiling mechanism replaces the traditional mechanical profiling mechanism, a PLC-based controller is adopted, a pressure value acquired by a pressure sensor is used as a feedback signal, logic operation is carried out in the controller by comparing the feedback signal with an ideal ditching pressure value, a current signal is output to control an electromagnetic directional valve and a pilot-operated electro-hydraulic proportional pressure reducing valve, so that a hydraulic cylinder completes the response action of rising or lowering, the ditching pressure is constant, the problem of inconsistent ditching depth caused by spring pressure change in mechanical profiling is solved, the system response is sensitive, and the control is accurate.

Drawings

FIG. 1 is a schematic diagram of the constant-pressure electro-hydraulic profiling ditching system for ditching of the present invention;

FIG. 2 is a structural diagram of the ditching constant-pressure electro-hydraulic profiling ditching system of the invention;

FIG. 3 is an exploded view of the pressure sensor mounting structure of FIG. 2;

fig. 4 is a sectional view of the pressure sensor fixing structure of fig. 2.

In the figure, 1-a double-disc furrow opener; 2-a pressure sensor; 3-four-bar linkage; 4, a hydraulic cylinder; 5-electromagnetic directional valve YV 2; 6-electromagnetic directional valve YV 1; 7-a pilot-operated electro-hydraulic proportional pressure reducing valve YV 3; 8-a throttle valve; 9-a first variable pump; 10-an overflow valve; 11-oil tank; 12-controller S7-200; 13-a transmitter; 14-a current amplifier; 15, a motor; 16-a second variable pump; 17-press wheel; 18-a frame; 19-a lateral connecting shaft; 20-a middle horizontal connecting shaft; 101-long handle; 102-a protective cover; 103-bolt; 104-a tray; 105-hollow fixing sleeve; 106-fixing hole.

Detailed Description

The invention is described in further detail below with reference to the figures and the specific embodiments.

As shown in figure 1, the ditching constant-pressure electro-hydraulic profiling ditching system has a mechanical structure as shown in figure 2, and comprises a hydraulic workstation, a hydraulic-four-bar profiling mechanism and a plurality of ditching and pressing units arranged on a frame. Each group of ditching and pressing units comprises a double-disc furrow opener 1 and a pressing wheel 17, and the double-disc furrow opener 1 and the pressing wheel are both installed on the frame 18 through fixing seats and are arranged in a front-back opposite mode.

The hydraulic work station comprises an oil tank 11, a second variable pump 16 and a motor 15 which are both fixed on the oil tank 11. The hydraulic-four-bar copying mechanism comprises a hydraulic cylinder 4 and two sets of four-bar mechanisms 3 which are vertically and correspondingly arranged in parallel, wherein one side of each set of four-bar mechanism 3 is connected with an oil tank 11, and the other side of each set of four-bar mechanism 3 is connected with a rack 18; one end of the hydraulic cylinder 4 is connected with a lateral transverse connecting shaft 19 on one side of the upper four-bar mechanism 3, and the other end of the hydraulic cylinder 4 is connected with a middle transverse connecting shaft 20 fixed on the lower four-bar mechanism 3, so that the hydraulic cylinder 4 controls the lifting of the two sets of four-bar mechanisms 3, and meanwhile, the middle transverse connecting shaft 20 is fixed at the middle point of the lower four-bar mechanism 3 to reduce the working stroke of the hydraulic cylinder 4; in addition, in this embodiment, two ends of the hydraulic cylinder 4 are matched with the lateral transverse connecting shaft 19 and the middle transverse connecting shaft 20 on one side of the upper four-bar mechanism 3 to be shaft holes so as to prevent the hydraulic cylinder 4 from being displaced by lateral stress.

Referring to fig. 3 and 4, the fixing base includes a supporting plate 104, a hollow fixing sleeve 105 disposed in the middle of the surface of the supporting plate 104, a long handle 101 and a pressure sensor 2, the top end of which is inserted into a hollow cavity of the hollow fixing sleeve 105, a fixing hole is formed in the top surface of the hollow fixing sleeve 105, the fixing hole 106 is communicated with the hollow cavity, the pressure sensor 2 is inserted from the fixing hole 106 until the lower external thread of the pressure sensor 2 is connected with the upper internal thread of the long handle 101, a protection cover 102 is inserted into a U-shaped groove in the top surface of the hollow fixing sleeve 105 until the upper external thread of the pressure sensor 2 is clamped at a U-shaped notch of the protection cover 102, a bolt 103 is mounted at the upper external thread of the pressure sensor 2 until the bolt 103 abuts against the protection cover 102, and the pressure sensor 2, the long handle.

As shown in fig. 1, the hydraulic control system further comprises a controller 12 (model number of the controller is S7-200), a transmitter 13, an electromagnetic directional valve VY16, an electromagnetic directional valve VY 25, an overflow valve 10, a pilot type electro-hydraulic proportional pressure reducing valve YV37 and a throttle valve 8. An oil inlet B1 of a left cavity of the hydraulic cylinder 4 is connected with an oil outlet B2 of an electromagnetic directional valve YV 16, an oil inlet A1 of a right cavity of the hydraulic cylinder 4 is connected with an oil outlet A3 of an electromagnetic directional valve YV 25, an oil outlet B4 of a pilot-operated electro-hydraulic proportional pressure reducing valve YV37 is connected with an oil inlet A2 of an electromagnetic directional valve YV 16, an oil return port C2 of the electromagnetic directional valve YV 16, an oil return port C3 of the electromagnetic directional valve YV 25 and an oil return port C4 of the pilot-operated electro-hydraulic proportional pressure reducing valve YV37 are communicated with the oil tank 11, the first variable pump 9 is connected with an oil outlet A4 of the pilot-operated electro-hydraulic proportional pressure reducing valve YV37 through a throttle valve 8, an oil inlet A5 of the overflow valve 10 is connected with the first variable pump 9, and an oil; the output end of the pressure sensor 2 is connected with the pressure signal input end of the transmitter 13, the current signal output end of the transmitter 13 is connected with the input ends of the controllers S7-200, the control signal output ends of the controllers S7-200 are connected with the control signal input ends of the electromagnetic directional valve YV 16, the electromagnetic directional valve YV 25 and the pilot type electro-hydraulic proportional pressure reducing valve YV37 through the current amplifier 14, and the controllers S7-200 are powered by a DC24V power supply.

Pressure sensor 2 pair actual ditching pressure F₁Collecting, processing the actual ditching pressure by the transmitter 13, transmitting the obtained electric signal into the controller S7-200, and transmitting the electric signal into the controller S7-200 according to the actual ditching pressure F₁Ideal ditching pressure F₀After logical operation, current signals are output, current amplification is carried out through the current amplifier 14, the opening degrees of valve ports of the electromagnetic directional valve VY16, the electromagnetic directional valve VY 25 and the pilot type electro-hydraulic proportional pressure reducing valve YV37 are controlled, the pressure in the hydraulic cylinder 4 is adjusted, and the actual ditching pressure is guaranteed to be constant.

The working flow of the invention is shown in figure 4, before the system starts to work, according to the agricultural requirements and the soil characteristics, the ideal ditching pressure value F required by the ditching depth is determined₀And the ideal ditching pressure value F is set₀And furrow pressure error value E are both input to controller S7-200 and motor 15 is activated.

When the ditching ground surface is flat, the actual ditching pressure is constant, namely | F₁-F₀And E, controlling the left access circuit of the electromagnetic directional valve VY16, the electromagnetic directional valve VY 25 and the pilot-operated electro-hydraulic proportional pressure reducing valve YV37, enabling the oil path to be blocked, and enabling the oil pumped by the first variable pump 9 to flow back to the oil tank 11 from the oil port B5 through the overflow valve 10.

When the surface is raised, the actual ditching pressure is increased, i.e. | F₁-F₀I > E and F₁-F₀When the pressure value of the hydraulic cylinder 4 is larger than the preset pressure value of the pilot type electro-hydraulic proportional pressure reducing valve YV37, the oil flows out from an oil port B1, a pilot valve of the pilot type electro-hydraulic proportional pressure reducing valve YV37 is opened, the oil at the outlet of the pilot type electro-hydraulic proportional pressure reducing valve YV37 flows back to the oil tank 11 from an oil port C4 through the pilot valve of the pilot type electro-hydraulic proportional pressure reducing valve YV37, the hydraulic cylinder 4 contracts, and the double-disc furrow opener 1 is lifted until the actual ditching pressure is restored to the ideal ditching pressure value F37₀；

When the surface is sunken, the actual ditching pressure is reduced, i.e. | F₁-F₀I > E and F₁-F₀The hydraulic oil flows into the hydraulic cylinder 4 from the oil port B1, the hydraulic cylinder 4 extends, the double-disc furrow opener 1 descends until the ditching pressure is recovered to a set value;

after the motor 15 is turned off and the first variable pump 9 stops working, the electromagnetic directional valve YV 25 and the electromagnetic directional valve YV 16 are switched on at the right position, the double-disc furrow opener 1 is manually lifted, the furrow opener is prevented from being pressed when being contacted with the ground in indoor storage, machinery and a hydraulic system are protected, a system power supply is cut off after the completion, and the system is recovered to an initial state.

The hydraulic profiling mechanism replaces the traditional mechanical profiling mechanism, a PLC-based controller is adopted, a pressure value acquired by a pressure sensor is used as a feedback signal, logic operation is carried out in the controller by comparing the feedback signal with an ideal ditching pressure value, a current signal is output to control an electromagnetic directional valve and a pilot-operated electro-hydraulic proportional pressure reducing valve, so that a hydraulic cylinder completes the response action of rising or lowering, the ditching pressure is constant, the problem of inconsistent ditching depth caused by spring pressure change in mechanical profiling is solved, the system response is sensitive, and the control is accurate.