JPS6134766B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a sensor for detecting the depth of descent of the ground work device from the ground based on the amount of vertical movement of the ground follower, on the ground work device attached to the tractor so as to be able to move up and down. Relating to an automatic lifting control mechanism for ground working equipment that is configured to automatically raise and lower the ground working equipment based on detection results from a sensor so that the descending depth is equal to the set working depth given by a working depth setting device. It is.

In the above control mechanism, in order to lower the ground work equipment as quickly as possible to the set work depth after it has been raised into the air, the ground work equipment is rapidly raised to a level a certain distance above the set work depth. After that, it was lowered slowly, and during control, it was raised and lowered slowly to stabilize the control. However, if the height of the ridge changes or the amount of subsidence of the tractor itself changes, the ground level at which slow descent starts will change, and if the slow descent start level is higher than the ground, the setting work will be difficult. It takes time to reach the depth, and if the ground is hard and the slow descent start level is below the ground, there is a risk that the ground work equipment will be plunged into the ground rapidly, causing a large shock or sudden load. , and even if the ground level does not change, when the ground is soft, it is more advantageous in terms of time to plunge into the ground to a certain extent and then start a slow descent. Slow descent started from a certain ground level, and it took time to reach the set working depth.

The present invention aims to solve such problems.

Embodiments of the present invention will be described below based on the drawings.

FIG. 1 shows a side view of a riding-type tiller, in which a rotary tiller 2, which is an example of a ground work device, is connected to the rear of a tractor 1 via a lift arm 3 so as to be movable up and down. The lift arm 3 is driven by a single-acting hydraulic cylinder 4, and an electromagnetic switching valve 5 for controlling the cylinder 4 is connected to a control circuit shown in FIG. 3.

In the figure, reference numeral 6 denotes a variable resistor as a working depth setting device for defining a target working level (plowing depth), which is installed near the control section of the tractor 1 and can be changed and adjusted as desired. Reference numeral 7 denotes a potentiometer that serves as a sensor for indicating the depth of descent of the rotary tillage depth device 2 from the ground, which is attached to the tillage device frame 22, and uses the rear cover 8 of the tillage device 2 as a ground follower to control its vertical swing amount. The output changes accordingly. 9
is a subtraction circuit which calculates the difference between the setting signal from the setting device 6 and the detection signal from the sensor 7, and here the deviation amount of the detected ground descent depth from the set working depth is taken out. Reference numeral 10 designates a rise determination circuit that compares the output signal from the subtraction circuit 9 with the rise reference signal, and 11 represents a similar descent determination circuit, which determines whether to raise, lower, or maintain neutrality based on the deviation from the set working depth. It is determined here whether it is necessary. 12 is a rising current amplification circuit connected to the rising discrimination circuit 10;
Reference numeral 13 denotes a descending current amplification circuit connected to the descending discrimination circuit 11, which is a rising or descending current amplification circuit 1.
0 and 11, the ascending excitation section 14 or the descending excitation section 15 of the electromagnetic switching valve 5 is driven. Further, 16 is a switch for forced ascent which, when closed, directly activates the ascent current amplifying circuit 12 and also checks the operation of the descending current amplifying circuit 13, and is provided near the control section. .

The above configuration is not particularly different from the conventional one,
The tillage depth is stabilized by controlling the up-and-down movement of the tilling device 2 so as to balance the detection signal of the sensor 7 with the setting signal.

In addition to the basic configuration described above, the present invention incorporates the following circuit.

That is, the detection signal from the sensor 7 is compared in the comparison circuit 18 with a reference signal given by the slow descent start depth setter 17 that sets the depth of descent from the ground at which the tilling device 2 starts slow descent, When the detection level becomes lower than the set level, that is, when the rear cover 8 is raised and swung above a certain level, the comparison circuit 18
The intermittent signal generation circuit 19 is configured to activate the intermittent signal generation circuit 19 connected to the intermittent signal generation circuit 19.
is connected to the descending current amplification circuit 13. Therefore, if the lowering determination circuit 11 operates while the intermittent signal generating circuit 19 is activated, the tilling device 2 is lowered at a slow speed as a result of intermittent valve driving.

In this embodiment, the setting device 17 is adjusted so that the detection level for activating the intermittent signal generation circuit 19 is a value at which the rear cover 8 swings to its lowering limit due to its own weight. .

Therefore, after completing one stroke of tilling, the tilling device 2 is raised to the upper limit by operating the switch 16 to change the direction of the machine.
6 and moves forward while lowering the tilling device 2. In this case, the descending region until the rear cover 8 touches the ground is a rapid descent due to continuous descent, and the tilling device 2 is moved forward after the rear cover 8 touches the ground. In the deep descending region, the descent is slow due to intermittent descent.

Note that a dedicated ground follower 8 of the sensor 7 may be used separately from the rear cover.

Further, 20 in FIG. 3 is a lift arm angle detection potentiometer attached to the base end of the lift arm 3, and by switching the circuit changeover switch 21 from the illustrated position to the reverse position, Based on the signal from the setting device 6 and the detection signal from the potentiometer 20, it is possible to switch to a position control mode in which the tilling device 2 is raised and lowered. With this configuration, the tilling device 2 can be held at any position in the entire lifting range according to the amount of operation of the setting device 6.

As explained above, according to the automatic lifting mechanism of the ground work equipment according to the present invention, as shown in this embodiment, the detection level for activating the intermittent signal generation circuit is such that the ground follower swings to its lowering limit due to its own weight. When the slow descent start depth setter is adjusted to a value that is moving, the ground follower is at the lowering limit, regardless of changes in the working depth or changes in the amount of sinking of the tractor itself. In other words, the ground work equipment descends rapidly from the air until it almost touches the ground, and after the ground follower touches the ground, the subsequent descent to the set working depth is performed slowly, and the work equipment descends underground. It has become possible to reach the set working depth as quickly as possible with almost no entry impact.

Therefore, even when lowered while traveling, the time it takes for the working device to reach the set working depth is short, so the unprocessed area (remaining plowed area in the case of a tilling device) where the working device travels without touching the field is reduced. I am now able to work more efficiently.

In particular, when the ground follower moves upwards from the lowering limit, it switches to low-speed descent, so the ground follower is not pushed up rapidly and shockingly, and mechanical shock is less likely to act on the sensor, reducing the plowing depth. This is effective in improving the durability of the detection mechanism as a whole.
Furthermore, according to the present invention, it is possible to freely set the depth of ground descent at which slow descent begins, so when the ground is soft and the impact of the work equipment entering the ground is relatively small, the ground work equipment By allowing the robot to plunge into the ground to a certain extent before starting a slow descent, it has become possible to perform work efficiently depending on the hardness and softness of the ground.

[Brief explanation of the drawing]

The drawings show an embodiment of the automatic lifting control mechanism for a ground work device according to the present invention, in which FIG. 1 is a side view showing the rear part of the tiller, FIG. 2 is a side view showing the point at which the rear cover starts touching the ground, and FIG. The figure is a control circuit diagram. 1...Tractor, 2...Ground work equipment, 6...
Working depth setter, 17... Slow descent start depth setter, 18... Comparator, 7... Sensor, 8... Ground follower.

Claims (1)

[Scope of Claims] 1. A sensor 7 is attached to the ground work device 2 mounted on the tractor 1 so as to be able to rise and fall freely, and detects the depth of descent of the ground work device 2 from the ground based on the vertical movement amount of the ground follower 8.
The ground working device is configured to automatically raise and lower the ground working device 2 based on the detection result of the sensor 7 so that the detected ground descending depth is equal to the set working depth given by the working depth setting device 6. In the automatic elevation control mechanism, the ground follower 8 at the lowering limit is set to be near the lower end of the ground work device 2, and the slow speed is set to set the ground descent depth at which the ground work device 2 starts slow descent. The comparator circuit 18 compares the signal output from the descent start depth setter 17 and the signal output from the sensor 7 until the ground working device 2 is lowered from the air and reaches the set slow descent start depth. Automatic lifting and lowering of ground work equipment characterized in that a mechanism for switching the lowering speed is linked to the sensor 7 so that the lowering speed is rapidly lowered in the lowering area between 1 and 2, and the lowering speed is lowered slowly in the lowering area up to the set working depth thereafter. Control mechanism. 2 The absolute descending speed of the ground work device 2 is constant,
2. The control mechanism according to claim 1, wherein the control mechanism is configured to perform continuous lowering in a rapid descending region and intermittent lowering in a slow descending region.