JPS5934324B2 - Combine cutting height adjustment device - Google Patents

Description

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

The mowing height adjustment device of the combine switches the oil path by operating an electromagnetic directional control valve equipped with a solenoid that is energized by a manual switch and an automatic switch that opens and closes depending on the distance between the cutting part and the ground surface. The mowing height of one culm can be adjusted by operating the mowing section to raise and lower the mowing section.

By the way, with conventional cutting height adjustment devices, the raising and lowering speed of the cutting section is the same whether it is manually adjusted by operating a manual switch or automatically adjusted by operating an automatic switch. The appropriate speed is set for manual adjustments that require relatively slow lifting, such as emergency adjustments at the time of cutting, and lowering of the reaping unit at the start of mowing.

However, such settings have the following disadvantages when automatic adjustment is performed in a field with many unevenness.

In other words, when the cutting height sensor suddenly detects a concave area and the automatic switch responds to this, the cutting section quickly lowers.
If this recessed portion is small, the tip of the reaping section will hit the soil ahead of the recessed portion, damaging it.

Further, by lowering the reaping section too quickly and faithfully to accommodate irregularities in the field, a hunting phenomenon is caused due to overcorrection, which impairs the stability of the control.

The present invention has been developed in view of the above circumstances, and while manual adjustment lowers the reaping section relatively quickly as in the past, automatic adjustment lowers the reaping section at a slower speed. The purpose of the present invention is to provide a combine harvester that satisfies the conflicting demands of protecting the tip of the reaping section by lowering the harvester, controlling stability, and quickly lowering the reaping section at the start of mowing.
The present invention will be explained in detail below based on drawings showing embodiments thereof.

FIG. 1 shows a combine harvester equipped with a cutting height adjustment device according to the present invention, in which a mounting rod of a grass dividing plate 2 constituting a reaping section 1 is provided with a distance between the grass dividing plate 2 and the ground surface. A sensor arm 3 is arranged in layers and rotates to move downward and upward in response to the movement.

The reaping section 1, the threshing section tortoise operator's seat 10, etc. move vertically around the rear part of the main frame as a center of rotation by the vertical movement of the piston rod 4a of the hydraulic cylinder 4 attached to the front part of the main frame. As a result, the reaping section 1 is moved up and down.

As shown in FIG. 2, the hydraulic circuit consisting of the hydraulic cylinder 4, 3-point/3-position switching type electromagnetic directional control valve 5, hydraulic pump 6, etc. is activated by energizing the solenoid 5u of the electromagnetic directional control valve 5. The directional control valve 5 is in the switching position U, the oil field in the hydraulic cylinder 4 rises to raise the reaping part 1, and the electromagnetic directional control valve 5 is in the switching position d by energizing the solenoid 5d.
When the hydraulic pressure in the hydraulic cylinder 4 decreases and the reaping section 1 is lowered by its own weight, and the electricity to the solenoids 5u and 5d is cut off, the electromagnetic directional control valve 5 is at the neutral position n, and the hydraulic pressure is lowered. The cylinder 4 has the electromagnetic directional control valve 5 at the neutral position n
The oil pressure is maintained at the same level as when the oil pressure returns to , and the reaping section 1 stops raising or lowering at that point.

The electric circuit shown in FIG. 2 shows a circuit for controlling the supply of electricity to the solenoids 5u and 5d, including a battery 11, a key switch 12 for the combine harvester, and a manual automatic changeover switch 13.
, a manual switch 14 and an automatic switch 15, both of single-pole double-throw type. It also includes a switching member 16 that is adjusted to repeat opening and closing at relatively short predetermined time intervals, such as a combination of a flicker relay, a timer relay, or a pulse generation circuit and a switching circuit that is controlled on and off by the pulse generation circuit.

The reaping up and down lever T is arranged on the left side of the driver's cab 8.

The T-shaped switching operation groove shown together with the head of the reaping up/down lever 7 in Fig. 2 is viewed in plan with the right side of the figure facing the front of the machine and the left side of the figure facing the rear of the machine, in line with the reaping section 1 of Fig. 2. The manual and automatic modes can be switched by operating the reaping up/down lever 7 in the horizontal direction of the machine (vertical direction in Figure 2), and by operating it in the longitudinal direction of the machine (right/left direction in Figure 2). (operation) to switch between manual lowering and raising.

That is, the manual automatic changeover switch 13 is turned on by locking the reaping up/down lever 7 in the groove on the right side (lower side in the figure) of the machine body, and also in the groove on the left side (upper side in the figure) in front (right side in the figure) of the machine body. By engaging the manual switch 14, the manual switch 14 is inserted into the switching terminal 14d, and by engaging the groove on the left side (upper side of the figure) and the rear (left side of the figure) of the machine body, the manual switch 14 is turned on.
is applied to the switching side terminal 14u.

On the other hand, the automatic switch 15 is interlocked with the sensor arm 3, and when the sensor arm 3 is lowered by more than a predetermined amount, the automatic switch 15 is inserted into the switching terminal 15d. When this happens, the automatic switch 15 is turned on to the switching terminal 15u.

And these connections are as follows.

The common terminal 14c of the manual switch 14 is the key switch 12
The switching side terminals 14u and 14d of the manual switch 14 are connected to the batch January 1 through the solenoids 5u and 5d, respectively.
connected to one end of the

Further, one end of the intermittent switching member 16 is connected to the battery 11 via the manual automatic changeover switch 13 and the key switch 12.
The other end of the intermittent switching member 16 is connected to the common terminal 15c of the automatic switch 15.

Switching terminals 15u and 15d of the automatic switch 15 are connected to one end of the solenoids 5u and 5d, respectively, and the other ends of the solenoids 5u and 5d are grounded to the body.

The device of the present invention configured as described above has a key switch 12.
After closing the reaping lever 7, the manual switch 1 is activated by engaging the reaping up/down lever 7 with the switching operation groove on the left front or rear side of the machine.
4, the common terminal 14c and the switching side terminal 14d or 14u are connected, and the solenoid 5d or 5u is energized.

As a result, the electromagnetic directional control valve 5 becomes the switching position d or U, so that the oil pressure in the hydraulic cylinder 4 decreases or increases, and the reaping section 1
falls or rises.

In other words, the mowing height is manually adjusted by such an operation, but the energization to the solenoid 5d or 5u is continuous as long as the reaping up/down lever 7 is engaged with the front or rear left side of the machine body in the switching operation groove. Therefore, the mowing section 1 can be raised and lowered quickly, and emergency adjustment of the mowing height, which is the purpose of manual adjustment, is possible.

At the start of mowing, by engaging the reaping up/down lever 7 with the switching operation groove on the front left side of the machine body, the reaping section 1 can be lowered continuously and quickly to achieve the desired purpose.

Next, by locking the reaping up/down lever 7 in the switching operation groove on the right side of the machine body field, the manual automatic changeover switch 13 is closed and automatic adjustment is performed.

The sensor arm 3 descends or ascends depending on the size of the distance between the grass divider plate 2 and the ground surface, so when the amount of descent or elevation exceeds a predetermined amount, the sensor arm 3 connects the common terminal 15c of the switch 15 to the switching side. Terminal 15d or 15u is connected.

The power input automatic cut-off switch 13 and the automatic switch 15 start energizing the solenoid 5d or 5u from this point.
Since the intermittent switching member 16 operates by closing the circuit, the energization of the solenoid 5d or 5u is performed intermittently at predetermined time intervals determined by the fixed or variable operating characteristics of the intermittent switching member 16.

Therefore, the electromagnetic directional control valve 5 is repeatedly switched between the switching position d or U and the neutral position n in response to interruptions in energization, and the oil pressure in the hydraulic cylinder 4 is gradually lowered or increased.
As a result, the reaping section 1 is also gradually lowered or raised.

In other words, during automatic adjustment, the lowering of the reaping unit 1 is performed intermittently and gently, and even if the sensor arm 3 suddenly enters a recessed area and the automatic switch 15 responds, the reaping unit 1 Since the lowering is delayed, if the recessed portion is small, the tip of the reaping section 1 will not be stuck into the soil ahead, and it can be protected.

Furthermore, since the movement of the reaping section 1 is delayed compared to the movement of the sensor arm 3, over-correction is not caused, and the stability of control is improved.

In this embodiment, even when raising the cutting, the automatic adjustment speed is set to be slower than the manual adjustment speed, so it is possible to manually raise the cutting section in an emergency, and the control in the case of lifting is easy. The contradictory requirements of increasing stability can also be satisfied.

Furthermore, during automatic adjustment, the oil passage is switched intermittently by the electromagnetic directional control valve 5 as described above, but the rise and fall characteristics when the oil pressure rises and falls in the hydraulic circuit are slow. moves up and down smoothly, without any unnatural pulse-like movements.

FIG. 3 shows another embodiment of the present invention, in which the same intermittent switching members 16A and 16B are used as the on/off control circuit for energizing the solenoids 5d and 5u by the automatic switch 15 and the solenoid 5d and 5u by the manual switch 14, respectively.
It is provided in the on/off control circuit for energization to 5u.

As shown in FIGS. 4A and 4H, the closing time tA of the intermittent switching member 16A is adjusted to be shorter than the closing time tI3 of the intermittent switching member 16B.
As a result, when the intermittent switching member 16A is activated, the lifting speed outside the reaping section during automatic adjustment is determined by the intermittent switching member 16A.
The speed is lower than the lifting speed of the reaping section during manual adjustment when B is activated.

In the case of this embodiment, in addition to obtaining the same effects as the embodiment shown in FIG. can be arbitrarily selected, which has the advantage of facilitating the design of the hydraulic circuit.

As detailed above, the cutting height adjustment device for a combine harvester according to the present invention is such that the speed of the cutting section when lowered by the automatic switch is slower than that when lowered by the manual switch, so manual adjustment is required. quick operability and
It is possible to realize a cutting height adjustment device that satisfies both requirements of control stability during automatic adjustment.

[Brief explanation of drawings]

The drawings show embodiments of the present invention, and FIG. 1 is a perspective view of a combine harvester equipped with the device of the present invention, FIG. 2, and FIG.
The figure shows an electric circuit diagram together with a hydraulic circuit diagram of the device of the present invention, and FIGS. 4A and 4B show an intermittent switching member 16A used in the device of the present invention shown in FIG. 16 is a time chart showing the opening/closing time of each of 16B. 1... Reaping part, 2... Grass division board, 3...
...Sensor arm, 4...Hydraulic cylinder,
5...Solenoid directional control valve, 5u, 5d...
・Solenoid, I... Reaping upper and lower lever, 13...
...Manual automatic changeover switch, 14...Manual switch, 15...Manual switch, 16° 16A
, 16B... Intermittent switching member.

Claims (1)

[Claims] 1. The oil path is switched by the operation of an electromagnetic directional control valve equipped with a solenoid whose energization is controlled on and off by a manual switch and an automatic switch that opens and closes according to the distance between the reaping part and the ground surface, and a hydraulic cylinder is operated. In a combine harvester cutting height adjustment device that raises and lowers a reaping section, the speed of the reaping section when lowering is controlled by the automatic switch,
A mowing height adjusting device characterized in that the mowing height adjusting device is set to be slower than the speed of the mowing section when lowered by the manual switch.