JPS5842725B2 - Work equipment height control device for mobile agricultural machinery - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a working machine height control device for a mobile agricultural machine.

Mobile agricultural machinery such as harvesters and tractors are functionally required to work close to the ground in fields, so they are equipped with automatic control devices that automatically raise and lower the height of the machinery from the ground. Generally, the work equipment is equipped with such equipment, but when the work equipment is to be driven over ridges or on the road, it is necessary to raise and hold the work equipment to a certain height using a manual control device.

However, in the past, a changeover switch separate from the manual lever was provided as a means of switching between the manual control circuit and the automatic control circuit of the work equipment, so even if the manual lever was operated by forgetting to operate the changeover switch or malfunctioning, As a result, there are many cases in which the circuit does not operate, resulting in an accident in which the working machine collides with a convex part of the ground, causing damage to the working machine.

To solve these drawbacks, the work equipment is controlled manually while the manual lever is operated, and when the manual lever is released, the work equipment is automatically switched from the manual control circuit to the automatic control circuit. An interlocking circuit that is automatically controlled has already been proposed, but in this case, if the work equipment is to be raised for a long period of time, it is necessary to hold the manual lever operated to the manual lift position in that position. Therefore, there is a drawback that the operator's other work activities are restricted, and the problem that the operation of the manual lever is complicated still remains unsolved.

The purpose of the present invention is to solve the above-mentioned conventional problems, and to effectively utilize the work machine that rises by lifting the manual lever even if the work machine is equipped with a ground height sensor that rises with the work machine. By placing a switch in the automatic control circuit based on the height above ground sensor, which detects the position of the work equipment that has risen to a fixed height and turns off the automatic control circuit based on the height above ground sensor that has risen with the work machine,
To provide a working machine height control device for a mobile agricultural machine that can simplify the operation of a passive lever for holding the working machine in a raised position.

A working machine height control device for a mobile agricultural machine according to the present invention that achieves the above object selectively switches the working machine of the mobile agricultural machine between a lowering circuit and an ascending circuit using a manual lever energized and held so as to be able to always restore the working equipment to a neutral position. The automatic control circuit is configured to control the height above the ground by a control circuit consisting of a manual control circuit configured to automatically control the height above the ground, and an automatic control circuit configured to perform automatic control based on the sensing operation of the height above the ground sensor when the manual lever is in the neutral position. A switch is disposed in the control circuit to detect the position of the working machine that has risen to a certain height and is activated, and the operation of the switch turns off the descending circuit of the automatic control circuit based on the sensor for detecting the height above the ground that has risen together with the working machine, This is characterized in that the work implement can be held in the raised position regardless of the return of the manual lever.

Next, an embodiment of the present invention will be described with reference to the drawings. A pre-processing section 3 (working machine) that swings up and down with a hydraulic cylinder 2 is attached to the front part of a reaping and harvesting machine 1 which is a mobile agricultural machine. .

Further, the hydraulic cylinder 2 is connected to a strainer 5 from an oil tank 4.
It is operated by a hydraulic pump 6 that sucks in oil through a pressure cylinder and discharges it under pressure. An electromagnetic switching valve 8 is interposed between the hydraulic cylinder 2 and the hydraulic pump 6 via a pressure reducing valve 7. Also, a speed control valve 9 is provided between the electromagnetic switching valve and the hydraulic cylinder 2.

The electromagnetic switching valve 8 of the hydraulic system 10 of the pre-processing section 3 configured as described above has three positions: a cylinder up position 8as, a cylinder stop position (neutral position) 8b, and a cylinder down position 8c using two solenoids 11 and 12. The spool is moved to the required position.

Further, the electric circuit for controlling the solenoids 11 and 12 is divided into a manual control circuit 13 and an automatic control circuit 14.

Of these, the manual control circuit 13 is connected to a manual lever 15 (see FIG. 3) disposed in the operation chamber of the reaping and harvesting machine 1.
The manual lever 15 is a circuit for operating the preprocessing section 3, and the manual lever 15 is rotatably supported at its intermediate portion.

Further, the side surface of the lower end of the manual lever 15 facing the swinging force is elastically supported by a compression coil spring 16, 16, and due to their balance, the manual lever is normally located at a neutral position.

Further, switches 17 and 18 are arranged below the pivot point of the manual lever 15 so as to be located on the side of the manual lever in the swinging direction.

Among the switches 17 and 18 arranged in this manner, one of the normally open contacts 17a of the switch 17 is connected to the positive side of the power supply 19, and the other is connected to one terminal of the relay coil 20, so that the normally open contact 17a of the switch 17 is The other terminal is connected to the negative side of the power source 19.

Further, among the solenoids 11 and 12, the lifting solenoid 11 is wired in series with the normally open contact 20a of the relay coil 20, and these are arranged in parallel with the power source 19 to form a manual lifting circuit 21. has been done.

Further, the lowering solenoid 12 is wired in series with the normally open contact 18a of the switch 18, and these are arranged in parallel with the power source 19 to form a manual lowering circuit 22.

On the other hand, the automatic control circuit 14 is a circuit that automatically adjusts the height of the pretreatment section 3 using a sensor 24 suspended from the grass support frame 23 of the pretreatment section 3.

The sensor 24 is formed into a substantially L shape, and one end of the sensor 24 is rotatably supported on the side wall of a switch box 25 placed on the grass cutting support frame 23. A coil spring 26 is inserted so that the sensor 24 is always urged downward.

A pair of sensor switches 28 and 29 are provided oppositely on the left and right sides of the swinging force of the switch operating piece 27 extending upward from its pivot point.

The normally open contact 28a of one of the sensor switches 28 and 29 arranged in this way is wired in series with the lifting solenoid 11, and they are arranged in parallel with the power source 19. The automatic lift circuit 30 is configured by the above.

Further, the normally open contact 29a of the other sensor switch 29 is wired in series with the lowering solenoid 12, and the normally closed contact 20b of the relay coil 20 is connected between them.
and the normally closed contact 18b of the manual lowering switch 18 are interposed in series, and between the normally open contact 29a and the lowering solenoid 12 is a detection switch 3 which will be described later.
Two normally open contacts 32a are also interposed.

They are arranged in parallel with the power supply 19 to form an automatic lowering circuit 31.

As shown in FIG.
A roller 34, which is a part of the sensor, is arranged so as to come into contact with the roller 34.

The cam presses the roller 34 of the detection switch 32 to turn on the normally open contact 32a until the pre-processing section 3 reaches a certain height, and when the working machine reaches a certain height, the cam It has a cam curve that opens the roller and turns off the normally open contact 32a.

The detection switch 32 is attached to a bracket 35 extending from the hydraulic cylinder 2 as shown in FIG. 6, and its roller 34 is brought into contact with a cam 36 formed at the tip of the piston 2a of the hydraulic cylinder. While the piston is rising to a certain position, the roller 34 is pressed to turn on the normally open contact 32a of the detection switch 32. When the piston rises above a certain height, the roller 34 is opened and the normally open contact 32a of the detection switch 32 is turned on. The open contact 32a may be turned off.

When adjusting the height of the pre-treatment section 3 of the reaping/harvesting machine 1 using the work machine height control device configured in this way, the manual lever 15 is left in the neutral position when automatically controlled. When the power switch (not shown) is turned on, for example, if the pretreatment section 3 has risen within a certain height, the sensor 24 will rotate in the direction of arrow A in FIG. 4 due to the biasing force of the torsion coil spring 26 and its own weight. Since the sensor switch 29 is in the ON state in advance, the switch operating piece 27 is in the ON state.

Further, at this point, the detection switch 32 is in the ON state, the relay coil 20 does not work, and its normally closed contact 20b maintains the same position, and the normally closed contact 18b of the manual lowering switch 18 is conductive. Therefore, the descending solenoid 12 is energized, the spool of the electromagnetic switching valve 8 moves, and the cylinder descending position 8c communicates with the hydraulic cylinder 2, and the oil in the cylinder is released by the piston, which descends due to the weight of the pretreatment section 3. 2a, it is pushed out of the cylinder.

The extruded oil is then throttled by the speed control valve 9, returns to the oil tank 4 through the cylinder lowering position 8c, and the hydraulic cylinder 2 moves at the speed set by the speed control valve 9. descend.

When the preprocessing section 3 descends and the sensor 24 comes into contact with the ground such as a field, the sensor moves in the direction of arrow B in FIG. 4, and the sensor switch 29 is turned off.

Therefore, the excitation of the lowering solenoid 12 is released, and
The spool of the electromagnetic switching valve 8 is at the cylinder stop position 8b
By returning to and stopping the hydraulic cylinder 2, the preprocessing section 3 maintains the appropriate height position from the ground.

Further, when the reaping harvester 1 moves and the ground level of the field becomes higher, the sensor 24 moves in the direction of arrow B in FIG. 4, and the switch operating piece 27 contacts the sensor switch 28 to turn it on. .

Therefore, the lift solenoid 11 is energized, the spool of the electromagnetic switching valve 8 moves, and the cylinder lift position 8a is moved.
As a result, the hydraulic cylinder 2 and the hydraulic pump 6 are communicated with each other, so that the pressurized oil sent from the pump causes the piston 2a of the hydraulic cylinder 2 to rise and move the pretreatment section 3 upward.

When the preprocessing section 3 moves upward, the sensor 24 rotates in the direction of arrow A in FIG. 4 and separates from the sensor switch 28, so that the sensor switch is turned off.

Therefore, the excitation of the lifting solenoid 11 is released, and
The spool of the electromagnetic switching valve 8 is at the cylinder stop position 8b
By returning to and stopping the hydraulic cylinder, the pre-processing section 3 maintains the appropriate height position from the ground.

Note that the detection switch 32 is always in the ON state when the preprocessing section 3 is automatically raised and lowered.

In this way, the pretreatment unit 3 automatically moves up and down within two predetermined ranges depending on the unevenness of the field, and always maintains an appropriate height.

If you suddenly find an obstacle in front of the pre-processing section 3 of the reaping/harvesting machine 1 while it is being automatically controlled as described above, the manual lever 15 should be activated (the same applies when the reaping/harvesting machine 1 is running on the road). When it is tilted to the raised position, that is, to the left in FIG. 3, the manual raising switch 17 is turned on and the relay coil 20 is energized.

Therefore, the normally open contact 20a is turned ON, and the lifting solenoid 11 of the electromagnetic switching valve 8 is energized, and the pre-processing section 3 can rise and escape from the obstacle in the same way as the above-mentioned action.

At this time, by energizing the relay coil 20, the normally closed contact 20b provided in the automatic lowering circuit 31 is opened, and as a result, as the preprocessing section 3 rises, the sensor 2
4 rotates in the direction of arrow A in FIG. 4 to turn on the sensor switch 29, the lowering solenoid 12 does not operate.

Thus, when the preprocessing section 3 that has been manually raised to an appropriate position is released from the manual lever 15, the lever is returned to the neutral position by the compression coil spring 16.

When the manual lever 15 returns to the neutral position, the manual lift switch 17 is turned off, so the excitation of the relay coil 20 is released, and as a result, its normally open contact 2
0a is opened, the excitation of the lifting solenoid 11 is also canceled, and the spool of the electromagnetic switching valve 8 returns to the cylinder stop position 8b.

However, at this point, the preprocessing section 3 has risen above a certain height, so the detection switch 32 is in the OFF state and the automatic lowering circuit 31 is cut off.

Therefore, even if the manual lever 15 is in the neutral position, the normally closed contact 18b of the manual lowering switch 18 is turned on, and the sensor switch 29 is turned on, the automatic lowering circuit 31 does not work and all electric circuits are turned off. Since the cylinder is disconnected, the spool of the electromagnetic switching valve 8 maintains the cylinder stop position 8b.

Therefore, even if the manual lever 15 is released, the pretreatment section 3 stops at that position, and the pressurized oil sent from the hydraulic pump 6 is unloaded and returns to the oil tank 4.

To lower the pre-processing section 3 below a certain height, tilt the manual lever 15 to the right in FIG. Then, the manual lowering circuit 22 operates to lower the pre-processing section 3.

However, the manual lever 15 was lowered to a certain position or below.
When released, the normally closed contact 18b of the manual lowering switch 18 is turned on.

In addition, the detection switch 32 is turned on again, and
Since the sensor switch 29 is already in the ON state due to the weight of the sensor 24 as the pre-processing section 3 rises, the automatic lowering circuit 31 works and energizes the lowering solenoid 12 to lower the pre-processing section 3 and raise it again. control automatically.

Also, even during automatic control, when the manual lever 15 is tilted to the right in FIG. 3, the normally open contact 18a of the manual lowering switch 18
is turned ON, and at the same time its normally closed contact 18b is turned OFF, so the automatic lowering circuit 31 is turned OFF, and the manual lowering circuit 22 is turned ON to excite the lowering solenoid 12, and the pre-processing section 3 is unconditionally turned ON. can be lowered.

When the manual lever 15 is released, the normally open contact 18a of the manual lowering switch 18 is turned OFF and at the same time, the normally closed contact 18b is turned ON, and the automatic lowering circuit 31 is activated, making it difficult to perform particularly complicated operations. It is possible to switch between manual and automatic mode without any hassle.

In addition, as shown in FIG. 2, the sensor switch 28
By wiring the normally closed contact 28b of the manual lowering switch 18 to the normally open contact 18a of the manual lowering switch 18, the preprocessing section 3 can be lowered by manual control and the manual lever 15 can be left tilted to the right. , the sensor 24 is grounded and the sensor switch 2
Since the normally closed contact 28b of No. 8 is turned OFF and the normally open contact 28a thereof is turned ON, the preprocessing section 3 automatically rises, so that the preprocessing section does not crash into the ground.

Furthermore, according to the embodiment described above, even if the pretreatment section, which is a working machine, stops for a long time at a certain height or higher, the electromagnetic switching valve is at the neutral position and unloads the oil sent from the hydraulic pump. As a result, pressurized oil does not flow from the pressure reducing valve, and as a result, there are no problems such as loss of power or rise in oil temperature.

Furthermore, as shown in Figure 2, if you connect the normally closed contact of the sensor switch for raising and the normally open contact of the switch for manual lowering, you can lower the preprocessing unit while keeping the manual lever down. , Just before the pre-processing section touches the ground, the sensor switch for raising is activated, turning off the manual lowering circuit and turning on the automatic raising circuit.

Therefore, the pretreatment section has many advantages such as not colliding with the ground, and its effects are great.

In short, the working machine height control device for a mobile agricultural machine according to the present invention selectively switches the working machine of the mobile agricultural machine between a descending circuit and an ascending circuit using a manual lever energized and held so as to be able to always restore the working machine to a neutral position. The automatic control circuit is configured to control the height above the ground by a control circuit consisting of a manual control circuit configured as described above, and an automatic control circuit that performs automatic control based on the sensing operation of the height above the ground sensor when the manual lever is in the neutral position. The circuit is equipped with a switch that is activated by detecting the position of the work equipment that has risen to a certain height, and when the switch is activated, the lowering circuit of the automatic control circuit based on the sensor that detects the height above the ground that has risen with the work equipment is cut off, and the manual Since the work equipment can be held in the raised position regardless of the return of the lever, the work equipment of the mobile agricultural machine can be adjusted to the height above the ground using a control circuit consisting of a manual circuit using the manual lever and an automatic control circuit using the ground height sensor. Even if the machine is configured to control the height of the machine, a switch placed in the automatic control circuit that detects the position of the work machine raised to a certain height and activates it will cause the machine to rise along with the work machine when the manual lever is operated on the upward side. The descending circuit of the automatic control circuit based on the height sensing sensor is cut off and the work equipment is stopped at the raised position, and at the same time, the height sensing sensor above the ground, which has separated from the ground surface as the work equipment rises, automatically lowers.
When the manual lever returns to the neutral position at the lifting stop position of the work equipment due to the sensor detecting the lowered height above the ground, the lowering circuit of the connected automatic control circuit is activated and automatically prevents the work equipment from descending. Since the work equipment can be held in the raised position, even if the work equipment is equipped with a ground height sensing sensor that rises with the work equipment, the lifting of the work equipment itself can be effectively used and operation using the manual lever is extremely simple. can be done.

Moreover, even if the descending circuit of the automatic control circuit based on the ground height sensor is turned off when the work equipment is in the raised stop position, simply operating the manual lever to the descending circuit side will stop the work equipment in the raised position. It can be easily lowered from a working position to a working position near the ground, and by lowering to below a certain height along with the lowering work equipment, the lowering circuit of the automatic control circuit using the ground height sensing sensor is connected. By utilizing the restoration of the automatic control circuit based on the height above ground sensor, it is also possible to return the automatic control circuit based on the height above ground sensor to its working state.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention; Fig. 1 is an overall side view of a reaping harvester, Fig. 2a is a piping and wiring diagram of a height control device, and Fig. 2 is another embodiment of a height control device. Piping and wiring diagram of the control device, Figure 3 is a cross-sectional side view of a part of the manual lever,
FIG. 4 is a cross-sectional side view of a part of the sensor, FIG. 5 is an enlarged side view of the detection switch mounting portion, and FIG. 6 is an enlarged side view of the detection switch mounting portion of another embodiment. 3... Pre-processing section (work machine), 13...
Manual control circuit, 14... Automatic control circuit, 15.
...Manual lever, 18...Switch for manual lowering, 18a...Switch normally open contact, 18
b... Normally closed contact of the switch, 21...
・Manual ascending circuit, 22...Manual descending circuit, 24
......Sensor, 30...Automatic ascending circuit, 31...Automatic descending circuit, 32...Detection switch.

Claims (1)

[Claims] 1. A manual control circuit configured to selectively switch a working machine of a mobile agricultural machine between a descending circuit and an ascending circuit by means of a manual lever energized so as to be able to always restore it to a neutral position; The height above the ground is controlled by a control circuit consisting of an automatic control circuit that performs automatic control based on the sensing operation of the height sensing sensor, and the automatic control circuit is configured to operate upon detecting the position of the work equipment that has risen to a certain height. When the switch is operated, the descending circuit of the automatic control circuit by the above-mentioned ground height sensing sensor that has risen with the work machine is cut off, so that the work machine can be held in the raised position regardless of the return of the manual lever. A working machine height control device for a mobile agricultural machine O characterized by