A hydraulic valve group for adjusting the posture proportion of agricultural implements with two degrees of freedom

Abstract

The present invention provides a hydraulic valve group for proportionally adjusting the posture of a double-degree-of-freedom agricultural implement, which can simultaneously realize proportional adjustment of the horizontal balance of the agricultural implement and proportional adjustment of the height position, and is characterized in that: it comprises a first proportional solenoid valve and a pressure difference control valve, the oil inlet of the first proportional solenoid valve is connected to the P oil port, and the oil outlet thereof is divided into two paths, one of which is connected to the T oil port through a first throttle hole and a second throttle hole, and the other is connected to the oil inlet of the first electromagnetic reversing valve; the oil return port of the first electromagnetic reversing valve is connected to the T oil port, and the two oil outlets thereof are respectively Connected with the A oil port and the B oil port; the oil inlet of the differential pressure control valve is connected with the P oil port, and its oil outlet is connected with the oil inlet of the second electromagnetic reversing valve, and its differential pressure control port is connected between the first throttle hole and the second throttle hole; the oil return port of the second electromagnetic reversing valve is connected with the T oil port, and its oil outlet is connected with the oil inlet of the one-way valve; the oil outlet of the one-way valve is divided into two paths, one path is connected with the C oil port, and the other path is connected with the oil inlet of the second proportional electromagnetic valve through the third throttle hole; the oil outlet of the second proportional electromagnetic valve is connected with the T oil port.

Description

Technical Field

[0001] The invention relates to the technical field related to electro-hydraulic proportional control, and in particular to a hydraulic valve group for proportional adjustment of postures of agricultural implements with two degrees of freedom. Background Art

[0002] Nowadays, people pay more and more attention to the operating efficiency and quality of agricultural tools, and at the same time, the requirements for the automation of agricultural tools are getting higher and higher. During field operations, people hope that agricultural tools can achieve horizontal balance adjustment and height position adjustment simultaneously to overcome the adverse effects caused by uneven fields.

[0003] If there is no adjustment device attached to the farm implement, the farm implement driver needs to manually operate the lifting rod to adjust the height of the farm implement, and cannot do anything about the horizontal balance adjustment. In the prior art, the adjustment device of the farm implement simply uses an electromagnetic switch reversing valve to adjust the oil cylinder action to control the horizontal balance and height. Therefore, the adjustment accuracy is low, the adjustment action is not smooth, and it is easy to cause system oscillation. The driving feeling of the personnel is also very poor, and it is not suitable for wide-width agricultural machinery and paddy field operations. Therefore, there is an urgent need for a new type of farm implement adjustment device to solve the above problems. Summary of the invention

[0004] In order to solve the problems mentioned above, the present invention provides a dual-degree-of-freedom agricultural implement posture proportional adjustment hydraulic valve group, which can simultaneously realize the proportional adjustment of the horizontal balance of the agricultural implement and the proportional adjustment of the height position, thereby improving the adjustment accuracy, and the adjustment is soft and impact-free, and the driving experience is smooth and comfortable, which is suitable for wide-width agricultural implements and paddy field operations.

[0005] The technical solution is as follows:

[0006] A hydraulic valve group for proportional adjustment of posture of a double-degree-of-freedom agricultural implement, characterized in that: it comprises a first proportional solenoid valve and a pressure differential control valve, the oil inlet of the first proportional solenoid valve is connected to the P oil port, and the oil outlet thereof is divided into two paths, one path is connected to the T oil port through a first throttle hole and a second throttle hole, and the other path is connected to the oil inlet of the first solenoid reversing valve; the oil return port of the first solenoid reversing valve is connected to the T oil port, and the two oil outlets thereof are connected to the A oil port and the B oil port respectively; the oil inlet of the pressure differential control valve is connected to the P oil port, and the oil outlet thereof is connected to the oil inlet of the second solenoid reversing valve, and the pressure differential control valve is connected to the P oil port. The control port is connected between the first throttle hole and the second throttle hole; the oil return port of the second solenoid reversing valve is connected to the T oil port, and its oil outlet is connected to the oil inlet of the one-way valve; the oil outlet of the one-way valve is divided into two paths, one path is connected to the C oil port, and the other path is connected to the oil inlet of the second proportional solenoid valve through the third throttle hole; the oil outlet of the second proportional solenoid valve is connected to the T oil port; the P oil port is the oil inlet port of the hydraulic valve group, the T oil port is the oil return port of the hydraulic valve group, the A oil port and the B oil port are the output ports for the horizontal balance control of the agricultural implement, and the C oil port is the output port for the high and low position control of the agricultural implement.

[0007] Furthermore, the hydraulic valve group also includes a safety valve, the oil inlet of the safety valve is connected to the P oil port, and the oil outlet of the safety valve is connected to the T oil port.

[0008] Furthermore, the first proportional solenoid valve is a two-position two-way valve. When the first proportional solenoid valve is in the initial position, its oil circuit is disconnected, and when energized, its oil circuit is connected. Its flow rate increases in proportion to the electrical command signal received, and when powered off, it works in the initial position under the action of a spring.

[0009] Furthermore, the pressure differential control valve is a two-position, two-way valve, whose oil inlet is connected to the oil inlet of the first proportional solenoid valve, and whose pressure differential control port is connected to the oil outlet of the first proportional solenoid valve through a first throttle hole. The pressure differential control valve is used to adjust the pressure difference between the oil inlet and the oil outlet of the first proportional solenoid valve to remain constant when the oil circuit of the first proportional solenoid valve is opened, so that the flow rate output by the first proportional solenoid valve is proportional to the electrical command signal received, thereby realizing proportional adjustment control of the horizontal balance of the agricultural implement.

[0010] Furthermore, the first solenoid reversing valve is a two-position four-way solenoid valve. The first solenoid reversing valve is used to connect its oil inlet with the oil return port when it is in the initial position, and to transport oil to the B oil port when it is energized. When the power is off, it works in the initial position under the action of the spring, and the oil inlet is connected to the A oil port.

[0011] Furthermore, the second solenoid reversing valve is a two-position three-way solenoid valve. When the second solenoid reversing valve is in the initial position, its oil inlet is connected to the oil return port. When energized, its oil inlet is connected to the oil outlet to transport oil to the C oil port. When powered off, it works in the initial position under the action of the spring.

[0012] Furthermore, the one-way valve prevents the oil from flowing back from the C oil port to the second electromagnetic reversing valve, thereby preventing the agricultural implement from slowly falling down under its own weight.

[0013] Furthermore, the second proportional control valve is a two-position two-way valve. The second proportional control valve is used to disconnect its oil circuit when in the initial position and connect its oil circuit when powered on, so that the oil circuit from the C oil port to the T oil port is connected, and its flow rate increases in proportion to the electrical command signal received. When the power is off, it works in the initial position under the action of the spring.

[0014] The beneficial effects of the present invention are:

[0015] The present invention realizes proportional adjustment of the horizontal balance of the agricultural implement by controlling the first proportional solenoid valve and the first solenoid reversing valve, and ensures constant differential pressure at the valve port of the first proportional solenoid valve by the differential pressure control valve, thereby realizing that the adjustment characteristic of the first proportional solenoid valve is independent of the load pressure, and making the horizontal balance control characteristic highly adaptable; the present invention also divides the proportional adjustment of the height of the agricultural implement into two directions, namely, rising and falling. When rising, the second solenoid reversing valve is energized, and the liquid flow passes through the one-way valve and is output from the C oil port to enter the single-acting cylinder to lift the agricultural implement, and the excess flow is controlled by the second proportional solenoid valve to unload. Thereby, speed proportional regulation is realized. When descending, the second electromagnetic reversing valve loses power, the one-way valve is closed, and the farm implement discharges the oil of the single-acting cylinder under the action of gravity, inputs the oil from the C oil port, and then controls the speed through the regulation of the second proportional electromagnetic valve. Thus, the present invention can simultaneously realize the functions of proportional regulation of the horizontal balance of the farm implement and proportional regulation of the height position, thereby improving the regulation accuracy. The horizontal balance sensitivity can reach within 0.2 degrees, and the height position can reach within 2 cm. In addition, the regulation is gentle and impact-free, and the driving experience is smooth and comfortable, which is suitable for the beneficial effects of wide-width farm implements and paddy field operations. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the hydraulic valve group of the present invention. DETAILED DESCRIPTION

[0017] The present invention will be further described below in conjunction with the embodiments.

[0018] The following examples are used to illustrate the present invention, but they cannot be used to limit the scope of protection of the present invention. The conditions in the examples can be further adjusted according to specific conditions. Simple improvements to the method of the present invention under the premise of the concept of the present invention belong to the scope of protection claimed in the present invention.

[0019] like Figure 1As shown, a dual-degree-of-freedom agricultural implement posture proportional adjustment hydraulic valve group includes a first proportional solenoid valve 3 and a pressure difference control valve 2, wherein the oil inlet of the first proportional solenoid valve 3 is connected to the P oil port 11, and the oil outlet thereof is divided into two paths, one path is connected to the T oil port 12 through the first throttle hole 5 and the second throttle hole 6, and the other path is connected to the oil inlet of the first solenoid reversing valve 4; the oil return port of the first solenoid reversing valve 4 is connected to the T oil port 12, and the two oil outlets thereof are connected to the A oil port 13 and the B oil port 14 respectively; the oil inlet of the pressure difference control valve 2 is connected to the P oil port 11, and the oil outlet thereof is connected to the oil inlet of the second solenoid reversing valve 7, and the pressure difference control port thereof is connected between the first throttle hole 5 and the second throttle hole 6; The oil return port of the second electromagnetic reversing valve 7 is connected to the T oil port 12, and its oil outlet is connected to the oil inlet of the one-way valve 8; the oil outlet of the one-way valve 8 is divided into two paths, one path is connected to the C oil port 15, and the other path is connected to the oil inlet of the second proportional electromagnetic valve 10 through the third throttle hole 9; the oil outlet of the second proportional electromagnetic valve 10 is connected to the T oil port 12; the P oil port 11 is the oil inlet of the hydraulic valve group; the T oil port 12 is the oil return port of the hydraulic valve group; the A oil port 13 and the B oil port 14 are the output ports for the horizontal balance control of the agricultural implement, which transport oil to the double-acting hydraulic cylinder for horizontal adjustment; the C oil port 15 is the output port for the height position control of the agricultural implement, which transports oil to the single-acting hydraulic cylinder for height position adjustment.

[0020] The hydraulic valve group further comprises a safety valve 1, the oil inlet of the safety valve 1 is connected to the P oil port 11, and the oil outlet is connected to the T oil port 12, so as to ensure that the system pressure is not higher than the set pressure of the safety valve.

[0021] The first proportional solenoid valve 3 is a two-position two-way valve. Its oil circuit is disconnected when in the initial position and connected when powered. Its flow rate increases in proportion to the received electrical command signal. When powered off, it works in the initial position under the action of a spring.

[0022] The differential pressure control valve 2 is a two-position two-way valve, whose oil inlet is connected to the oil inlet of the first proportional solenoid valve 3, and whose differential pressure control port is connected to the oil outlet of the first proportional solenoid valve 3 through the first throttle hole 5. The differential pressure control valve 2 is used to adjust the pressure difference between the oil inlet and the oil outlet of the first proportional solenoid valve 3 to keep constant when the oil circuit of the first proportional solenoid valve 3 is opened, so that the flow output by the first proportional solenoid valve 3 is proportional to the received electrical command signal, and the proportional adjustment control of the horizontal balance of the agricultural implement is realized. At the same time, the differential pressure control valve 2 is set between the P oil port 11 and the second electromagnetic reversing valve 7, so that the differential pressure control valve 2 can send all the excess flow of the first proportional solenoid valve 3 to the downstream, which is just used by the second electromagnetic reversing valve 7, thereby improving the working efficiency of the equipment.

[0023] The first electromagnetic reversing valve 4 is a two-position four-way electromagnetic valve. When in the initial position, its oil inlet is connected to the oil return port. When powered, its oil inlet is connected to one of the two oil outlets to transport oil to the A oil port 13 or the B oil port 14. When powered off, it works in the initial position under the action of the spring.

[0024] The second electromagnetic reversing valve 7 is a two-position three-way electromagnetic valve. When in the initial position, its oil inlet is connected to the oil return port. When powered, its oil inlet is connected to the oil outlet to transport oil to the C oil port 15. When powered off, it works in the initial position under the action of the spring.

[0025] The one-way valve 8 prevents the oil from flowing back from the C oil port 15 to the second electromagnetic reversing valve 7, thereby preventing the agricultural implement from slowly falling down under its own weight.

[0026] The second proportional control valve 10 is a two-position, two-way valve. When in the initial position, its oil circuit is disconnected, and when powered, its oil circuit is connected, so that the oil circuit from the C oil port 15 to the T oil port 12 is connected, and its flow rate increases in proportion to the electrical command signal received. When the power is off, it works in the initial position under the action of the spring.

[0027] The working principle of the hydraulic valve group of the present invention is as follows:

[0028] The dual-degree-of-freedom agricultural implement posture proportional adjustment hydraulic valve group of the present invention is the core component of agricultural implement posture proportional adjustment, which needs to be connected to the tractor hydraulic system, and cooperates with the level adjustment double-acting oil cylinder, the height adjustment single-acting oil cylinder, the inclination sensor, the elevation sensor and the controller for joint control, so that the agricultural implement maintains horizontal balance and constant height. During the hydraulic pipeline connection process, the system oil supply is connected to the P oil port 11, the T oil port 12 is connected to the return oil or the oil tank, the A oil port 13 and the B oil port 14 are respectively connected to the lower chambers of the two level adjustment double-acting oil cylinders, the upper chambers of the two level adjustment double-acting oil cylinders are directly communicated, and the C oil port 15 is connected to the height adjustment single-acting oil cylinder; the inclination sensor and the elevation sensor (usually a laser sensor or a satellite differential receiver) are installed in the middle of the agricultural implement, and the controller is placed in the cockpit.

[0029] When the tractor is working, the uneven ground may cause the rear-mounted farm implement to tilt horizontally or rise and fall. This phenomenon is particularly obvious when working in paddy fields. The change in the posture of the farm implement will cause the quality of the work to decline, and the driver needs to make frequent adjustments, which will reduce the work efficiency.

[0030] During operation, assuming that the left side of the farm implement is too low, the inclination sensor will feed back the horizontal inclination of the farm implement to the controller. The controller will send a command to the first proportional solenoid valve 3 of the hydraulic valve group according to the size of the inclination deviation to adjust the valve port size of the first proportional solenoid valve 3, and send a command to the first solenoid reversing valve 4 according to the positive and negative angle deviation to adjust the direction of the oil to the cylinder, and control the oil to enter the lower chamber of the left balance cylinder. The oil will lift the left side and flow back to the hydraulic valve group from the lower chamber of the right balance cylinder, and then return the oil to the T oil port, and the angle deviation will decrease until the deviation is eliminated; when the angle deviation is equal to 0 or less than a certain set value, the command controls the first proportional solenoid valve 3 to close, and the first solenoid reversing valve 4 loses power and works in the default position; the differential pressure control valve 2 ensures that the differential pressure at the valve port of the first proportional solenoid valve 3 is constant, so that the control characteristics of the first proportional solenoid valve 3 do not change with the load pressure, thereby optimizing the control performance.

[0031] Assuming that the vehicle enters a deep pit, the elevation sensor detects that the displacement of the agricultural implement is decreasing, and the agricultural implement needs to be raised to maintain a predetermined height. The controller will energize the second electromagnetic reversing valve 7, and the oil will enter the check valve 8 through the second electromagnetic reversing valve 7, and flow out from the C oil port 15 into the single-acting cylinder to lift the agricultural implement. The second proportional electromagnetic valve 10 is controlled by the controller to unload during this process, and then adjusts the flow entering the oil cylinder to achieve proportional adjustment of the rising speed; if the vehicle drives onto a high platform, the elevation sensor detects that the displacement of the agricultural implement is increasing, and the agricultural implement needs to be lowered to maintain a predetermined height, the second electromagnetic reversing valve 7 loses power, the check valve 8 closes, and the agricultural implement discharges the oil in the single-acting cylinder under the action of gravity. The controller controls the second proportional electromagnetic valve 10 to adjust the opening size to control the lowering speed of the agricultural implement. When the height deviation of the agricultural implement is equal to 0 or less than a certain set value, the second electromagnetic reversing valve 7 and the second proportional electromagnetic valve 10 lose power. Due to the action of the check valve 8 and the check valve in the second proportional electromagnetic valve 10, the oil in the single-acting hydraulic cylinder is locked, and the agricultural implement maintains the current height position.

[0032] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A dual-degree-of-freedom agricultural implement posture proportional adjustment hydraulic valve group, characterized in that: It includes a first proportional solenoid valve and a differential pressure control valve, wherein the oil inlet of the first proportional solenoid valve is connected to the P oil port, and the oil outlet thereof is divided into two paths, one path is connected to the T oil port through the first throttle hole and the second throttle hole, and the other path is connected to the oil inlet of the first solenoid reversing valve; the oil return port of the first solenoid reversing valve is connected to the T oil port, and the two oil outlets thereof are connected to the A oil port and the B oil port respectively; the oil inlet of the differential pressure control valve is connected to the P oil port, and the oil outlet thereof is connected to the oil inlet of the second solenoid reversing valve, and the differential pressure control port thereof is connected between the first throttle hole and the second throttle hole; The oil return port of the second solenoid reversing valve is connected to the T oil port, and its oil outlet is connected to the oil inlet of the one-way valve; the oil outlet of the one-way valve is divided into two paths, one path is connected to the C oil port, and the other path is connected to the oil inlet of the second proportional solenoid valve through the third throttle hole; the oil outlet of the second proportional solenoid valve is connected to the T oil port; the P oil port is the oil inlet of the hydraulic valve group, the T oil port is the oil return port of the hydraulic valve group, the A oil port and the B oil port are the output ports for the horizontal balance control of the agricultural implement, and the C oil port is the output port for the high and low position control of the agricultural implement; the second proportional solenoid valve is a two-position two-way valve, the When the two proportional solenoid valves are in the initial position, their oil circuits are disconnected. When energized, their oil circuits are connected, so that the oil circuit from the C oil port to the T oil port is connected, and its flow rate increases with the proportion of the received electrical command signal. When the power is off, it works in the initial position under the action of the spring; the dual-degree-of-freedom agricultural implement posture proportional adjustment hydraulic valve group is connected to the tractor hydraulic system, the A oil port and the B oil port are respectively connected to the lower chambers of the two horizontal adjustment double-acting oil cylinders, the upper chambers of the two horizontal adjustment double-acting oil cylinders are directly communicated, and the C oil port is connected to the high and low position adjustment single-acting oil cylinder; the dual-degree-of-freedom agricultural implement posture proportional adjustment hydraulic valve group The proportional adjustment of the horizontal balance of the agricultural implement and the proportional adjustment of the height can be realized at the same time; the proportional adjustment of the height of the agricultural implement is divided into two directions: rising and falling. When rising, the second electromagnetic reversing valve is energized, and the fluid flows through the one-way valve and is output from the C oil port, entering the single-acting cylinder to lift the agricultural implement. The excess flow is controlled by the second proportional electromagnetic valve to unload, thereby realizing speed proportional adjustment. When descending, the second electromagnetic reversing valve loses power, the one-way valve is closed, and the agricultural implement discharges the oil from the single-acting cylinder under the action of gravity, enters from the C oil port, and then adjusts the speed through the second proportional electromagnetic valve.

2. A dual-degree-of-freedom agricultural implement posture proportional adjustment hydraulic valve group according to claim 1, characterized in that: The hydraulic valve group further comprises a safety valve, the oil inlet of the safety valve is connected to the P oil port, and the oil outlet of the safety valve is connected to the T oil port.

3. The dual-freedom agricultural implement posture proportional adjustment hydraulic valve group according to claim 1, characterized in that: The first proportional solenoid valve is a two-position, two-way valve. When the first proportional solenoid valve is in the initial position, its oil circuit is disconnected, and when energized, its oil circuit is connected. Its flow rate increases in proportion to the electrical command signal received. When the power is off, it works in the initial position under the action of the spring.

4. The dual-freedom agricultural implement posture proportional adjustment hydraulic valve group according to claim 1, characterized in that: The pressure difference control valve is a two-position two-way valve, and is used to adjust the pressure difference between the oil inlet and the oil outlet of the first proportional solenoid valve to remain constant when the oil circuit of the first proportional solenoid valve is opened.

5. The dual-freedom agricultural implement posture proportional adjustment hydraulic valve group according to claim 1, characterized in that: The first solenoid reversing valve is a two-position four-way solenoid valve. The first solenoid reversing valve is used to connect its oil inlet with the oil return port when in the initial position. When energized, its oil inlet delivers oil to the B oil port. When powered off, it works in the initial position under the action of the spring, and the oil inlet is connected to the A oil port.

6. The dual-freedom agricultural implement posture proportional adjustment hydraulic valve group according to claim 1, characterized in that: The second solenoid reversing valve is a two-position three-way solenoid valve. When the second solenoid reversing valve is in the initial position, its oil inlet is connected to the oil return port. When energized, its oil inlet is connected to the oil outlet to transport oil to the C oil port. When the power is off, it works in the initial position under the action of the spring.

7. The dual-freedom agricultural implement posture proportional adjustment hydraulic valve group according to claim 1, characterized in that: The one-way valve prevents the oil from flowing back from the C oil port to the second electromagnetic reversing valve.

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