JPS6137010A - Automatic plowing depth controller - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] B) Industrial Application Field The present invention relates to an automatic tillage depth control device for automatically keeping the tillage depth of a rotary constant in a tractor, and more specifically, it relates to an automatic tillage depth control device for automatically keeping the tillage depth of a rotary constant. The present invention relates to an automatic plowing depth control device that detects depth, controls a valve based on the detected value, and operates a lift arm to raise and lower the plowing depth so that the plowing depth is constant.

(B) Conventional Technology Conventionally, automatic tillage depth control devices can be roughly divided into mechanical and electrical types. The mechanical type transmits the vertical movement of the rotary rear cover to a cable via a link, which then rotates a link on the tractor body side to operate the control valve, and the movement is purely mechanical. It is something that is communicated.

On the other hand, with the electric type, the rotation of the rotary rear cover is difficult. The information is transmitted to a plowing depth sensor consisting of a meter, which converts the rear cover position, that is, the amount of plowing depth, into a voltage change and transmits it to the controller, which then compares and judges the set value and operates the electromagnetic switching valve. It is something.

2) Problems to be Solved by the Invention Incidentally, in the mechanical type, the amount of rotation of the rotary rear cover is transmitted to the control valve via cables and links, so the transmission performance may be affected by the connection play and deflection of the links that inevitably occur. If the cable deteriorates, and if the cable is improperly adjusted, too tight or too loose, the performance will further deteriorate. In addition, once the links are connected, the amount of movement of the rear cover determines the amount of operation of the control valve due to the fixed transmission ratio of the link mechanism, so depending on the work conditions, the frequency of switching the control valve may be increased or decreased. If you perform an operation that involves

On the other hand, in the case of an electric type, the rotary can be connected to the controller of the tractor body using an electric wire, no adjustment of the transmission cable is required, and there is extremely little mechanical transmission loss. It is also possible to adjust the switching frequency of the valve in the controller by adjusting the width of the dead zone in which no output is produced within a certain range of the signal from the plowing depth sensor relative to the set value. However, since the electric type uses an electromagnetic switching valve, the movement of the manual lift lever must be converted into a stain pressure change using a potentiometer, and the manual operation part also needs to be modified.

An even more important problem is that in the case of a mechanical type, the spool of the control valve is provided with a slit, so that the slit is applied when switching from neutral to raised position, and the slits and slits when the rotary moves up can be easily removed. In the case of an electric type, the flow rate cannot be controlled with a normal electromagnetic switching valve, and the rotary is raised rapidly, resulting in a step on the finished soil surface after it is mixed.1; There is ice. For this purpose, an electromagnetic switching valve for pulse width modulation (PWM) control is used, and in the case of a slight increase, it is necessary to repeatedly cycle between neutral and raising. It is expensive, creates problems in installation space, and causes a significant increase in cost. In addition, some tractors of the same model do not require an automatic tillage depth control device, but in other tractors, mechanical control valves are used because the electrical components are expensive and the device becomes a big loss. Even in the same model, there is no commonality of hydraulic actuating devices, which poses the problem of significantly increasing manufacturing costs.

B) Means for Solving the Problem The present invention aims to solve the above-mentioned problems, and uses a mechanical control valve for lift arm elevation control, and a plowing depth detection system for automatic plowing depth control. The signal from the rotary rear cover that constitutes the member is converted into a voltage change by a plowing depth sensor, the controller compares it with a set voltage and operates an actuator, and the actuator operates a mechanical control valve. Furthermore, the link mechanism 2 operates a mechanical control valve 3 and also feeds the movement from the lift arm 5 to the mechanism 2. Further, the vertical movement of the lift arm 5 based on the valve 3 is transmitted to the rotary 6, and the rear cover of the rotary 6 (
The plowing depth detected by the plowing depth detection member 7 is converted into an electrical signal such as a voltage change by a plowing depth sensor 9 consisting of a potentiometer, and the signal from the sensor 9 is input to the controller 10. The controller 10 also has a comparison/judgment circuit A1, a plowing depth setting device B1, which can be set arbitrarily by the operator, a dead band width setting device C1, and an output circuit, which sends a predetermined signal to the actuator 11. , the actuator 11 is connected to the mechanical control valve 3.

b) Operation Based on the above-described configuration, the control valve 3 is operated via the link mechanism 2 based on the operation of the manual lift lever 1,
The lift arm 5 is rotated by a hydraulic cylinder to raise and lower the rotary 6. Then, the amount of rotation of the lift arm 5 is fed to the link mechanism 2, and the control valve is returned to the neutral position at the rotation position of the lift arm 5 corresponding to the operating position of the manual lever 1. So-called position control is performed. Furthermore, when the rear cover 7 touches the ground as the rotary 6 descends and the plowing depth of the rotary 6 is detected, the plowing depth amount by the rear cover 7 is converted into a stain signal by the plowing depth sensor 9, and the plowing depth from the sensor 9 is detected. The signal is controller 10
, the plowing depth setting value from the plowing depth setter B and the dead zone value from the dead zone width setting device are compared and determined, and the signal is output to the actuator 11. Thereby, the actuator 11 operates the control valve 3 so that the detected value from the plowing depth sensor 9 and the set value from the plowing depth setter B match.

(F) Examples Examples of the present invention will be described below with reference to the drawings.

As shown in FIG. 2, the L tractor 15 has a fuselage 16, and the fuselage 16 includes a driver's seat 1 consisting of a seat 17, etc.
9 is disposed, and a hydraulic device 20 is disposed below it. The hydraulic system 20 includes a tank 21, a hydraulic pump 22, a mechanical control valve 3, and a hydraulic cylinder 23, and the hydraulic cylinder 23 is connected to a lift arm 5.
The power arm 25 is connected to the power arm 25. In addition, a lower link 26 and a top link 27 are provided at the rear of the fuselage 16.
are connected to each other, and a lift arm 5 is connected to the lower link 26 via a lift drawer and a lift 29, respectively, and a rotary 6 is connected to the lower link 26 and top link 27, so that the tractor 15 is equipped with a re-rotary 6 using a special three-point linkage device, and is also equipped with a re-rotary 6.

Power is transmitted to the India Z1. Also, rotary 6
It has a main body 30, a tilling claw 31, a main cover 32, etc., and a pivot pin 33 is provided at the rear of the main cover 32.
The rear cover 7 is rotatably supported by. The rear cover 7 presses down the soil tilled by the tilling claws 31 from above to level it, and can also detect the tilling depth H based on the rotational position of the rear cover 7. Furthermore, the rear cover 7 has a bulge installed on the rotary body 30 via a link 35. A plowing depth sensor 9 consisting of a meter is connected,
The sensor 9 detects the plowing depth H based on the rotating position of the rear cover 7.
Converts into voltage change. Further, a controller 10 is disposed in the tractor driver's seat 19, and a signal from the plowing depth sensor 9 is connected to the controller 10 by an electric wire. Further, an actuator 11 consisting of an electric cylinder or a hydraulic cylinder is disposed adjacent to the tractor hydraulic system 20, and the actuator 11 is connected to the controller 10.
The control valve 3 is controlled by signals from the control valve 3, and is connected to a control valve 3 via a link mechanism 2, which will be described later.

As shown in FIG. 3, the link mechanism 2 has an arm 36 that is connected to the manual lift lever 1 and rotates together around a pivot shaft 35. It is connected to one end of the position control link 37 by 37a. Furthermore, the other end of the control link 37 is connected to a connecting pin 37.
The link 38 is connected to an arm 40 rotatably supported around a pivot shaft 39 by a pin 40a.

Further, the other end of the arm 40 is connected to the arm 4 via a pin 40b.
1, and the other end of the arm 41 is connected to the power arm 2 which rotates together with the lift arm 5 by a pin 41a.
It is connected to 5. On the other hand, an arm 42 rotatably supported by the pivot shaft 35 has one end connected to it by a pin 43a, and an automatic plowing depth control link 43 is disposed adjacent to and overlapping the position control link 37. , the other end of the control link 43 is connected to a link 45 via a pin 43b. Furthermore, the other end of the link 45 is connected by a pin 45m to an arm 46 that is rotatably supported around the pivot shaft 39, and the arm 46 rotates together around the pivot shaft 39. Actuator 11 via link 47
is connected to.

The spool 3& of the control valve 3 is biased downward by a spring 49, and a valve link 50 is connected to the tip of the spool 3&. Further, a compliance pin 50m is connected to the tip of the valve link 50 facing the position control link 37 and the automatic plowing depth control link 43, and the pin 50m is rotatably supported on the pivot shaft 35. It is connected to and supported by an arm 51.

Further, as shown in FIG. 4, the mechanical control valve 3 has a slit 52 formed in a portion of the spool 3a that communicates from the pump boat P to the cylinder boat S.
At the beginning of communication with the cylinder bow (S) of the spool 3a, a throttle acts, and oil is gradually sent from the pump boat P to the cylinder bow (SK).

Since the present embodiment has the above-described configuration, when the manual lift lever 1 is rotated in the upward direction as shown by the arrow X,
The arm 36 rotates together and the position control link 37
is rotated counterclockwise around its lower end pin 37b.

Accordingly, the control link 37 comes into contact with the speed bin 50a, moves the spool 3a against the spring 49, and operates the control valve 3 in the upward direction. Then, at the start of operation, the oil in the hydraulic pump 22 is first squeezed from the pump boat P through the slot and gate 52 and is gradually sent to the cylinder boat S, so that the hydraulic cylinder 23 moves the lift arm 5 without shocking it. It slowly rises and further raises the rotary 6 via the linkage devices 26,27. In addition, as the lift arm 5 rises, the power arm 25
By the rotation in the direction of arrow Y, the position control link 37 is now rotated counterclockwise and clockwise around the upper end bin 37m via the arm 41, 40, feeder, and clink 38. As a result, the compliance pin 50a is gradually returned in the direction of the arrow 2, but the control valve 3 is returned to the neutral position when the lift arm 5 is rotated to a position corresponding to the operating position of the manual lift lever 1. .

Further, when the manual lift lever 1 is fully lowered as shown in FIG. 3 and the rotary 6 is performing tilling work at a predetermined tilling depth H, the rear cover 7 detects the tilling depth H, and the rear cover 7 detects the tilling depth H. The rotational position of 7 is converted into a voltage change by the plowing depth sensor 9.

A signal from the sensor 9 is then sent to the controller 10. On the other hand, in the controller 10 of the driver's seat 19, the operator operates the setting dial in advance to set the plowing depth setter B to a predetermined voltage and the dead band width setter C to a predetermined sensitivity depending on the field. put. In this state, the signal from the plowing depth sensor 9 is compared with the set plowing depth value in the comparison/judgment circuit A, and if both values exceed the dead band width, an output signal is issued from the output circuit to the actuator 11. , drives the actuator 11 in a predetermined direction. For example, when the actuator 11 is moved in the direction M in FIG.
Move 0a in the two directions opposite to the arrow. As a result, the spool 3a is moved in the upward direction against the spring 49, and the lift arm 5 is rotated by operating the control valve 3.
The plowing depth is automatically controlled so that the plowing depth H by the rear cover 7 becomes the value set by the controller 10.

Note that during the automatic plowing depth control, the manual lift lever 1 is fully rotated in the downward direction as shown in FIG.
There is no sharp edge when it comes into contact with the manual operation system during automatic tillage depth control.

On the other hand, when performing manual position control, the relationship between the automatic tilling depth control link 43 and the speed bin 50a is set in a lowered state as shown in FIG. There's a lot to do.

Therefore, if automatic plowing depth control is not required, the actuator 11
All you have to do is remove the link 47, and there is no need to make any changes to the manual operation system.The parts other than the actuator 11 and the link 47 can be removed in advance from the hydraulic system case 20! If it is incorporated into L, it is extremely easy to add an automatic tillage depth control device later.

Also, during automatic plowing depth control, oil is throttled and gradually sent to the hydraulic cylinder 23 at the start of raising based on the slit 52 of the control valve 3, and the rotary 6 is controlled to raise so as not to cause any trouble. Of course.

(G) As described in detail, according to the present invention, the amount of movement of the plowing depth detection member (rear cover) 7 is converted into a stain signal by the plowing depth sensor 9, and the signal is sent to the controller 10. Therefore, since the mechanical control valve 3 is used, it is possible to eliminate link connection play and deflection, which are disadvantages of mechanical automatic deep-tiling devices, as well as performance and accuracy deterioration due to poor cable adjustment. Even without using a high-performance electromagnetic switching valve such as a control electromagnetic switching valve, by forming a slot, groove 52, etc. on the spool 3a, it is possible to eliminate the shock when the lift arm 5 starts to rise. Although it has a simple, inexpensive and compact configuration, it is possible to obtain a clean and highly accurate plowing depth and a finished soil surface after tilling.

Furthermore, the manual lift lever 1 is controlled via the link mechanism 2).
Since the actuator 11 operated by the controller 10 is connected to the control valve J via the link mechanism 2, it is possible to use the electric automatic depth control, but it is possible to use the manual lift lever. 1
The operating system requires a mechanism that is almost the same as the conventional one, and the hydraulic system N20 can be shared with models that do not require automatic tillage depth control, making it possible to significantly reduce manufacturing costs. It is also possible to easily add an automatic tillage depth control device later. In addition, since the plowing depth can be set electrically by the controller 10, it is also possible to easily set the sensitivity of the dead band width to adjust the switching frequency of the burrp 3 depending on the working conditions, allowing fine-grained and accurate control. It can be carried out.

[Brief explanation of drawings]

Fig. 1 is a diagram of the control system of the present invention, Fig. 2 is a side view showing a tractor and rotary to which the invention is applied, Fig. 3 is a side view showing its link mechanism, and Fig. 4 is a mechanical control valve. FIG.

Claims (1)

[Claims] (1) In an automatic tillage depth device that detects the tillage depth using a tillage depth detection member 7 installed on the rotary 6 and controls a valve for raising and lowering the lift arm 5 based on the detected value, the valve is mechanical. It also includes a tilling depth sensor 9 that converts the amount of movement of the tilling depth detection member 7 into an electric signal, and compares the signal from the sensor with the signal from the tilling depth setting device B. A controller 10 is provided which outputs an output to the actuator 11, and the manual lift lever 1 is connected to the control valve 3 via a link mechanism 2, and the actuator 11 is connected to the control valve 3 via the link mechanism 2. The configured automatic tillage depth control device.