JPS5817563B2 - Combine harvester - Google Patents

Description

[Detailed description of the invention] The present invention relates to an automatic cutting height adjustment device for a combine harvester.

In conventional devices, when the cutting section moves up and down in response to a lift signal, the lifting stops as soon as the cutting height falls within a preset dead zone, and therefore the cutting height is at the upper or lower limit of the set value. In many cases, the raising/lowering signal is issued many times due to slight irregularities in the field, and the hydraulic system has to be activated each time to raise/lower the reaping section, which reduces work efficiency and requires the operation of switches, etc. The disadvantage was that the parts were easily damaged.

The present invention aims to eliminate the above-mentioned drawbacks of the conventional device, and an embodiment shown in the drawings will be described below.

In Figures 1 and 2, 1 is a combine harvester, and 2 is a lifting device installed obliquely at the front of the fuselage of the combine 1, which uses a lifting claw (not shown) to lift the planted culm into an almost upright position. raise up to.

Reference numeral 3 denotes a cutting blade that cuts the base of the planted culm raised by the pulling device 2.

4 is the above-mentioned pulling device 2, cutting blade 3, and frame 5
The reaping part consists of a rod 8 of a hydraulic cylinder 7, etc.
The reciprocating motion of the robot is configured to move up and down with respect to the main body of the aircraft centering on the pivot point O.

Reference numeral 9 denotes a cutting height detection device mounted on the frame 5, which includes a sled body 10 that slides across the field and moves up and down according to the ups and downs of the field, and a vertical rod i1. , ii and tension spring 1
7, an operating rod 12 which is fixedly connected to the sled body 10, and which is shaped as seen in side view and follows the vertical movement of the sled body 10, and a pin 18. 11 are pivotably connected to each other by pins 18...

When the cutting height is within a preset range, the sled body 10 and the operating rod 12 are moved to the position A in FIGS. 2 and 3 due to the biasing force of the tension spring 17 and the reaction force from the field. In the state shown, the actuation rod 12 does not press contacts A and B, and contacts A and B remain open.

Next, when the cutting height is higher than a preset range, the sled body 10 is moved to the third position by the urging force of the tension spring 17.
It is displaced to the state shown in the figure, and the operating rod 12 moves downward to close the contact B.

On the other hand, if it is too low, the sled body 10 will be in the state shown in FIG. 3C, the operating rod 12 will move upward, and the contact point A will be closed.

As mentioned above, the cutting height changes depending on the unevenness of the field, etc.
When contact A or B is closed, a signal for raising and lowering the reaping section is generated through power source E.

13.14 is between contact A and relay Ry, and contact B
In the return continuation circuit inserted between and Ry2,
In this embodiment, it is composed of transistors Tr1yTr2, resistors R1 and R2, and +7 tearers C1 and C2.

The resistor R1 is directly connected between the base terminal of the transistor Tr1 and the contact A, and the resistor R3 is directly connected between the base terminal of the transistor Tr2 and the contact B.

The capacitor C1 is connected between the contact A and the intermediate point between the resistor R1 and the emitter terminal of the transistor Tr1, and the capacitor C2 is also connected between the intermediate point between the contact B and the resistor R3 and the emitter terminal of the transistor Tr3. It is connected to the.

In addition, SW in the figure is a main switch, and E is a power supply.

To explain the operation of the recovery continuation circuit 13 (or 14 and below), when contacts A and B are closed, base current flows to the base terminals of transistors Tr11 and Tr2, so that transistors Tr1. A collector terminal flows through Tr□, and relay Ry1. which is connected to the collector terminal as described later. Ry2 is instantly energized.

Also, when contact SB) is opened, the charges accumulated in capacitors C1 and C2 are discharged, and the time constant C
Since the time flows for 1 x R1 (C2 x R2) seconds, C1
×R1 (C2 × R2) seconds transistor Tr1 + T
relay Ry1. Current flows to Ry2 and relay Ry1. The energization of Ry□ is continued.

Then, after C1×R1 (C2×R2) seconds, relay Ry1.
Power supply to Ry2 ends.

In this way, the return continuation circuits 13 and 14 immediately operate the reaping unit for raising and lowering in response to the signal from the cutting height detecting device 9 when the cutting height of the reaping unit 4 is out of the set range, that is, the dead zone that does not require control. At the same time as outputting a return signal, the cutting height of the reaping section 4 returns to within the dead zone, and the cutting height detection device 9
Even if the control signal from the
C2×R2), and the reaping section 4
The mowing height is returned to near the center of the dead zone.

Reference numeral 15 denotes an ascending side priority circuit which, when an ascending signal and a descending signal exist at the same time, prevents the descending signal from being transmitted and transmits only the ascending signal to the hydraulic device 6, which will be described later.
One of the transistors Tr1. Relays Ry1 and Ry3 each connected to the collector terminal of Tr2, the other of which is grounded, and relay switch a1. of relay Ry1. b1
and relay switch b2 of relay Ry2.

Then, when relay Ry1 is energized, relay switch a
, is closed and relay switch b1 is opened.

As a result, the solenoid 5OL of the solenoid valve 16 of the hydraulic system 6
1 is energized, but since relay switch b1 is open, solenoid 5OL2 is not energized.

On the other hand, when relay Ry2 is energized, relay switch b2
is closed, but in this case as well, relay R
As long as y1 is energized, relay switch b1 is open, so solenoid 5OL2 is not energized.

That is, solenoid 5OL2 can be energized only when relay Ry1 is not energized.

Next, 6 is a hydraulic device that raises and lowers the reaping part 4. When the solenoid 5OL1 or 5OL2 is energized, the oil path of the solenoid valve 16 is switched, and the cylinder rod 8 of the hydraulic cylinder 7
reciprocates, and the reaping section 4 moves up and down with respect to the main body of the machine about the pivot point O.

Next, the operation of the above embodiment will be explained.

(2) When the cutting height is within the preset appropriate range, as described above, both contacts A and B are not closed and no lifting signal is generated, so the cutting height remains the same.

(2) When the cutting height is higher than the preset range, as described above, the sled body 10 swings to the position shown in FIG. 3, and the operating rod 12 closes the contact point B.

Then, a current flows through the base of the transistor Tr2 by the power source E, and conducts electricity from the collector to the relay Ry2 to the ground, and the contact of the relay switch b2 is closed.

If relay Ry1 is not energized, relay switch b
1 is closed, solenoid 5O of solenoid valve 16
L2 is energized, the oil path is switched, and the rod 8 of the hydraulic cylinder 7 moves in the direction of arrow P, lowering the handle 4.

Contact B will be opened as a result of this fall, but in this case, the charge accumulated in capacitor C2 will be discharged for C2 x R2 seconds as described above, so a current will flow to the base of transistor Tr2 within this time. flows, energization continues from the collector to the relay Ry2 to the ground, the energization of the solenoid 5OL2 is also maintained, and the lowering of the reaping section 4 is maintained.

In this embodiment, by adjusting the time C2 x R2 seconds (that is, by using a capacitor and resistor of appropriate values), the descending operation can be stopped near the center of the dead zone. be.

(2) When the cutting height is lower than the preset range, as described above, the sled body 10 is oscillated to the position shown in FIG. 3C, and the operating rod 12 closes the contact point A.

Then, a current flows through the base of the transistor Tr1 by the power source E, and the current flows from the collector to the relay Ry1 to the ground, and the relay switch a1 is closed.

Therefore, the solenoid valve 1 is connected from the power source E through the relay switch a.
The solenoid 5OL1 of No. 6 is energized and the oil path is switched, so that pressure oil is sent into the hydraulic cylinder γ, and the cylinder rod 8 moves in the direction of the arrow Q to raise the reaping section 4.

Also, since the relay switch b1 is opened at the same time as the relay switch a1 is closed, as long as the relay Ry1 is energized (that is, as long as the rising signal is present), the solenoid 5OL2 is not energized and always receives the rising signal. will be given priority.

As the reaping section 4 is raised, the contact point A is opened.

Then, the charge accumulated in capacitor C1 becomes C1x
Since R is discharged for seconds, a current flows through the base of the transistor Tr during this time, and the current flows from the collector to the relay Ry.
→The energization to the ground is maintained, the energization to the solenoid 5OL1 is also maintained, and the raising of the reaping part 4 is also maintained.

In this embodiment, C0×R1 seconds is adjusted so that the rise of the reaping section 4 continues until approximately the center of the dead zone.

As described above, in the present invention, since the return continuation circuit is provided, at the time when the charge accumulated in the capacitor C1 or C2 is discharged and the reaping section 4 continues to move up and down, There may be a rise signal and a fall signal, but in this case, the rise signal is applied to the hydraulic device 6 via the rise side priority circuit 15, so the rise signal always takes priority and is applied to the hydraulic device 6. It will be added to.

As described above, in the present invention, when entering the dead zone, the vertical movement is not stopped immediately, but the vertical movement is continued until approximately the center of the dead zone via the recovery continuation circuit, which is different from the conventional method. Unlike other devices, the cutting height does not have to move up and down frequently when the cutting height is near the upper or lower limit of the set value, greatly improving work efficiency and reducing the frequency of use of operating parts such as switches. This reduces the amount and improves durability.

Furthermore, as described above, in the present invention, when the raising signal and the lowering signal for the reaping section are present at the same time, priority is always given to the raising operation of the reaping section. Unexpected accidents can be prevented.

It should be noted that the present invention is not limited to the specific configuration of the above-described embodiment, and for example, the cutting height detection device 9 may be of a non-contact type (for example, an ultrasonic type, a photoelectric type, a capacitive type, etc.). ), it goes without saying that this includes various design changes, such as the use of

BRIEF DESCRIPTION OF THE DRAWINGS The drawings show one embodiment of the present invention; FIG. 1 is an overall side view of a combine harvester, FIG. 2 is an explanatory view, and FIG. 3 is an explanatory view of main parts.

1... Combine harvester, 4... Reaping section, 6
... Hydraulic pressure 1 device, 9 ... Cutting height detection device, 13, 14 ... Return continuation circuit, 15 ...
... Rising side priority circuit, 16... Solenoid valve.

Claims (1)

[Claims] 1. A cutting height detection device 9 that detects the cutting height of the cutting section 4;
an electric circuit that operates a solenoid valve 16 in response to a signal from the mowing height detection device 9 when the mowing height of the reaping section 4 is out of a control dead zone; a return continuation circuit that continuously inputs a return signal to the electromagnetic valve 16 until the cutting height of the reaping section 4 returns to the center of the dead zone, into the electric circuit; 13.14 and rising side priority circuit 15
An automatic cutting height adjustment device for a combine harvester, characterized in that it is provided with: