JPS6216602B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION According to the present invention, a ground work device mounted on a tractor so as to be able to rise and fall is provided with a sensor that detects the work depth based on the amount of vertical movement of the ground follower, and the detected work depth is determined by a setting device. The present invention relates to an automatic lifting control mechanism for a ground working device configured to automatically lift and lower the ground working device based on a detection result by a sensor so that the working depth is equal to a given set working depth.

Conventionally, the above control mechanism has, for example,
- As shown in Publication No. 124502, when the ground work equipment is once raised into the air and then lowered, the setting work depth must be set at a certain level in order to lower it as quickly as possible to the set work depth. Stabilization of control was achieved by rapidly descending the distance up to a high level, then slowly descending, and during control by slowly ascending and descending. However, if the working depth setting is changed,
If the amount of subsidence of the tractor itself changes, the ground level at which slow descent starts will change. If the slow descent start level is higher than the ground, it will take time to reach the set working depth, and When the slow descent start level was below the ground, the ground work equipment was rapidly plunged into the ground, causing a large shock and sudden load.

In addition, instead of setting the slow descent level to a predetermined value as described above, a shock absorber is attached to the ground work equipment itself to prevent the ground work equipment from colliding with the ground regardless of changes in the working depth setting. The means to avoid it are also
As disclosed in Japanese Patent No. 40-9302, this conventional technology uses wheels and sleds that touch the ground a certain amount earlier than the ground work equipment as shock absorbers. The system used a structure in which the relative displacement of the wheels and the ground work equipment was made slow due to the resistance of the fluid through the small holes, so that after the wheels and the sled touched the ground, Until the ground work equipment touches the ground, a relatively large relative movement distance is required to sufficiently dissipate the inertia in the downward direction of the ground work equipment. Even though you want to descend rapidly until you touch the ground, the range of slow descent is wide and you cannot descend quickly during this period, and there are traces of work such as plowing. Another drawback was that it left traces from being pushed by wheels or sleds.

The present invention prevents the ground work equipment from colliding with the ground with a large impact or from rapidly increasing the load, and also allows the ground work equipment to be properly positioned at the set working depth by touching the ground from a height close to the ground level. When lowering the work equipment slowly, lower the ground work equipment as rapidly as possible until it reaches the ground surface, and do not allow the ground work equipment to descend until it reaches the set working depth without causing a large impact or sudden impact. The purpose is to be able to carry out the work quickly without causing an increase in load, and to avoid leaving traces of the wheels behind the work as would be the case if a mechanical shock absorber was used. shall be.

The feature of the present invention for achieving the above object is that the working depth is determined by a ground working device that is attached to a tractor so as to be able to rise and fall based on the amount of vertical movement of a ground follower attached to the ground working device. A sensor is provided for detection, and the ground work device is automatically operated based on the detection result by the sensor so that the set working depth given by the first setting device that sets the working depth is equal to the working depth detected by the sensor. In an automatic lift control mechanism for a ground work device configured to raise and lower, a second signal outputs a signal corresponding to the amount of vertical movement of the ground follower relative to the ground work device when the lower end of the ground work device is approximately at the ground surface level. A setting device is provided, and a slow speed control circuit is provided for outputting a slow speed control command for lowering the ground working device at a slow speed to the lowering control circuit of the ground working device, and the slow speed control circuit is further provided. Based on the comparison result between the detected value by the sensor and the set value by the second setting device, the circuit is configured to adjust the slack for the descending control circuit in the descending region until the ground work equipment in the air reaches a position equivalent to the ground surface level. The sensor and the second This is because it is linked with a setting device, and this configuration provides the following functions and effects.

In other words, when detecting the ground surface level, rather than looking at the relative position of the ground work equipment with respect to the aircraft, the relative position of the ground work equipment that is raised and lowered and the ground follower attached to the ground work equipment is measured. The fixed value, that is, the positional relationship of the ground follower when the lower end of the ground work device has almost reached the ground level, is determined, and that value is determined as the setting value of the second setting device. Since this value is compared with the detected value of the sensor as a reference, it is possible to change the set working depth, change the amount of sinking of the aircraft into the ground surface due to changes in the hardness and softness of the running ground, etc.
Alternatively, even if the aircraft is tilted forward or backward, the ground handling device can reliably detect the ground level at which it should start slow descent without being affected by such various changes, and The work equipment can be lowered rapidly until it reaches very close to ground level. Therefore, by lowering the ground working equipment from the ground surface level to the set working depth at a slow speed, it is possible to avoid large impacts and sudden increases in load on the ground working equipment. This enabled rapid work to be carried out by rapidly descending to very close to the ground level.

In addition, as mentioned above, the reference position at which to start the slow descent of the ground work equipment is determined by comparing the set value and the detected value of the ground surface level, and the shock mitigation effect of the mechanical shock absorber is used. Since it does not start the slow descent by touching the ground, it not only allows the starting point of the slow descent to be as close to the ground surface as possible as described above, but also allows the use of the wheels as the grounding body of the shock absorber after work with the ground work equipment. This also avoids the inconvenience of leaving traces of running sleds.

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. 4.

In the figure, reference numeral 6 denotes a variable resistor as a first setting device for defining the target work level (plowing depth), which is provided near the control section of the tractor 1 and can be changed and adjusted as desired. Reference numeral 7 denotes a potentiometer as a working depth detection sensor, which uses the rear cover 8 of the tilling device 2 as a ground follower, and its output changes according to the amount of vertical swing thereof. Reference numeral 9 is a subtraction circuit that calculates the difference between the setting signal from the setting device 6 and the detection signal from the sensor 7, and the deviation amount of the detected working depth from the set working depth is extracted here. 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, and 13 is a falling current amplifying circuit connected to the falling discrimination circuit 11. Current amplification circuit 1
3 are activated by the outputs from the upward discrimination circuit 10 and downward discrimination circuit 11, respectively, and amplify the outputs to operate the upward excitation section 14 or the downward excitation section 15 of the electromagnetic switching valve 5. However,
It constitutes an ascending control circuit and a descending control circuit. 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 tilling 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 with the reference signal given by the second setter 17 in the comparison circuit 18, and when the detection level is lower than the set level, that is, the rear cover 8 rises above a certain level. When activated, the intermittent signal generation circuit 19 connected to the comparison circuit 18 is activated, and the intermittent signal generation circuit 19 is connected to the falling 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, and this intermittent signal Generator 19 constitutes a slow speed control circuit.

The second setter 17 is adjusted so that the detection level for activating the intermittent signal generation circuit 19 corresponds to the level at which the lower end of the tiller 2 contacts the ground.

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 move forward while lowering the tilling device 2. In this case, the descending region until the tilling device 2 touches the ground is a rapid descent due to the connected descent, and after that the descending region at the set plowing depth. Then it will be a slow descent with intermittent descent.

The second setting device 17 is adjustable, and the slow descent start level can be adjusted to some extent near the ground surface. Also, the ground follower 8 of the sensor 7
A dedicated one may be used separately from the rear cover. Also, when the ground follower 8 is at its free descent limit, if the lower end of the follower 8 is made to protrude beyond the lower end of the working device 2, the slow descent start level can be set a little higher than the ground surface. It becomes possible.

FIG. 3 shows details of the working depth detection section, and shows the frame 20 fixedly extended from the tilling device 2.
The sensor 7 is attached to the side surface of the sensor via a waterproof case 21, and a set bolt 23 is attached to the rotation shaft 22.
The tip of the arm 24 fixed at the rear cover (ground follower) 8 is connected to the rod 25 extending pivotally from the rear cover (ground follower) 8, so that the vertical swing of the rear cover 8 is transmitted to the rotation shaft 22. There is. By adjusting the extension and contraction of the rod 25 using the turnbuckle 26, the output of the sensor 7 is adjusted with respect to the rocking position of the rear cover.

Further, 27 in FIG. 4 is a lift arm angle detection potentiometer attached to the base end of the lift arm 3, and by switching the circuit changeover switch 28 from the illustrated position to the reverse position, Based on the signal from the first setter 6 and the detection signal from the potentiometer 27, it is possible to switch to a position control mode in which the cultivating 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 first setting device 6.

[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 work device starts touching the ground, and FIG. The figure is an expanded vertical rear view of the working depth detection section, and FIG. 4 is a control circuit diagram. 1...Tractor, 2...Ground work equipment, 6...
First setting device, 7...sensor, 8...ground follower,
13... descending control circuit, 17... second setting device,
19...Slow speed control circuit.

Claims (1)

[Scope of Claims] 1. A sensor 7 for detecting the working depth based on the amount of vertical movement of a ground follower 8 attached to the ground working device 2 is attached to the ground working device 2 which is attached to the tractor 1 so as to be able to move up and down. The ground working device 2 is automatically operated based on the detection result by the sensor 7 so that the setting working depth given by the first setting device 6 that sets the working depth is equal to the working depth detected by the sensor 7. In an automatic lifting control mechanism for a ground work device configured to raise and lower, a signal corresponding to the amount of vertical movement of the ground follower 8 relative to the ground work device 2 is output when the lower end of the ground work device 2 is approximately at the ground surface level. In addition, a slow speed control circuit 19 is provided for outputting a slow speed control command for lowering the ground working device 2 at a slow speed to the lowering control circuit 13 of the ground working device 2. Further, the slow speed control circuit 19 is controlled based on the comparison result between the detected value by the sensor 7 and the set value by the second setting device 17 until the ground work device 2 in the air reaches a position equivalent to the ground surface level. In the descending region, the ground work equipment 2 is rapidly lowered without outputting a slow speed control command to the descending control circuit 13, and in the subsequent descending region, a slow speed control command is output to the descending control circuit 13 to perform ground work. An automatic lifting/lowering control mechanism for a ground work device, characterized in that the mechanism is linked with the sensor 7 and the second setter 17 so as to slowly lower the device 2. 2 The absolute descending speed of the ground work device 2 is constant,
The automatic elevation control mechanism for a ground working device according to claim 1, wherein the automatic elevation control mechanism for a ground working device is configured to continuously descend in a rapid descending region and to intermittently descend in a slow descending region.