JPH0559681B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates generally to tractors, and more particularly to a tractor having a rotary working machine mounted so as to be able to rise and fall.

This type of tractor is generally provided with a sensor that detects the plowing depth based on the amount of vertical movement of the ground follower, and the detected plowing depth is equal to the plowing depth set by the plowing depth setting means. The vertical movement of the working machine is adjusted by an automatic lifting device.

Conventionally, in this type of automatic lifting control mechanism,
When the rotary work machine is lifted into the air and then lowered, it is set at a certain distance from the set plowing depth to prevent the large impact and dabbing phenomenon that occur when the rotary work machine plunges into the ground. It was configured to descend rapidly to a high level, then slowly descend after that, allowing the robot to ascend and descend slowly even during automatic elevation control. However, with this configuration, when the front wheel of the tractor falls into a dent or climbs onto the landing section and leans forward significantly, the rotor working machine connected to the rear of the tractor is quickly raised and plowed. When the plowing depth becomes shallow, this is detected by a sensor and descending control is performed, but since this descending control is a slow descending control as described above, it is not possible to quickly correct the plowing depth. There was a problem in that it caused residual tillage.

Therefore, the present invention is intended to improve the above-mentioned problems of the conventional technology, and its purpose is to provide a tractor that can prevent douching and can quickly adjust the plowing depth. .

The features of the present invention for achieving the above object include a rotary working machine 3 connected to the rear body of the tractor 1, and a rotary working machine 3 connected to the tractor 1 side.
A drive mechanism 29 is provided on the rotary work machine 3 side to detect the plowing depth of the rotary work machine 3. setting means 9 for setting the plowing depth of step 3;
and a switching device 23 that switches the rotary working machine 3 downward, and when the switching device 23 switches the rotary working machine 3 to the downward direction while the rotary working machine 3 is supported in the air, the rotary working machine 3 is switched to the downward direction. The tractor is equipped with a control means 67 such that the descending speed when lowered is slow until reaching near the ground and becomes faster after approaching the ground.

Embodiments of the present invention will be described below with reference to the drawings.

Figure 1 shows a rotary work machine 3 attached to the rear of a tractor 1.
The rotary working machine 3, that is, the rotary tilling device 3 is connected via a lift arm 15 so as to be movable up and down. The lift arm 15 is driven by the lift shaft 21 by the piston 19 of the single-acting hydraulic cylinder 17.
It is driven to swing up and down. The hydraulic cylinder 17 is provided with a switching valve 23.
As shown in FIG. 2, the spool 25 of No. 3 is provided so as to be movable left and right via an operating shaft 27 and a mechanical link mechanism 29, and is always moved to the right in FIG. 2 by a tension spring 31. is energized by When the spool 25 is moved, for example, to the left in FIG. If the piston 19 is moved to the right in the figure, the piston 19 moves backward and the lift arm 1
5 is configured to rotate downward. The switching valve 23 switches the pressure oil to the hydraulic cylinder 17 so that when the spool 25 reaches the intermediate position of the horizontal movement, the pressure oil in the hydraulic cylinder 17 is maintained as it is and the spool 25 reaches the neutral position.

The operating shaft 27 and the mechanical link mechanism 29 are connected to the second
It is constructed as shown in FIGS. That is, the operating shaft 27 is pivotally connected to the cylinder case 35, and the arm 3 is mounted inside the cylinder case 35.
7 is fixed to the operating shaft 27, and a pin 39 implanted at the tip of the arm 37 is inserted into a long hole of the link 41 to interlock and connect the arm 37 and the link 41.
The lower part of the link 41 is pivotally connected to a support shaft 43 fixed to the cylinder case 35, and the lower end is operatively connected to the lower part of the position link 45 via a pin 47. The position link 45 has a pin 4 implanted in the spool 25 into a long hole provided at the lower end.
9 are inserted and connected, and the upper end is interlocked and connected to the lift shaft 21 via a link 51. A position arm 53 is fixed to the operating shaft 27 on the outside of the cylinder case 35, and the tip of the position arm 53 is interlocked and connected via a link 55 to an arm 61 fixed to the output shaft 59 of the electric motor 57. are doing. Therefore, now lift arm 15
is in the upper position, when the electric motor 57 is reversely rotated, the operating shaft 27 is rotated by the arm 6 of the output shaft 59
1. The arm 37 and the link 41 are rotated counterclockwise via the link 55 and the position arm 53.
and a position link 45 via the support shaft 43.
is rotated counterclockwise in FIG. 2 about the support shaft 43, and the spool 25 is moved to the right in the same figure, so that the lift arm 15 is lowered. Then, the link 51 rotates clockwise together with the lift arm 15, and therefore the position link 45 rotates clockwise in FIG. The switching valve 23 is pushed to the left in the figure and returns to the neutral position, and the switching valve 23 stops discharging pressure oil from the hydraulic cylinder 17. In this way, the lift arm 15 is configured to hold the position instructed by the position arm 53 driven by the electric motor 57.

The electric motor 57 is attached to the tractor body 1, and is driven and controlled via a control mechanism 67 by a lift-to-automatic changeover switch 65 provided near the cockpit 63.

The operating shaft 27 is provided with a potentiometer 69 for detecting the rotational position of the electric motor 57. A plowing depth setting device 9 is provided near the operator's seat 63 of the tractor 1 for setting the target working depth (plowing depth) of the rotary tilling device 3 to a predetermined setting value.

Further, as shown in FIG. 5, the rotary tilling device 3 is provided with a potentiometer 7 as a working depth detection sensor.
is connected via a link 73 to the rear cover 5 that covers the cultivating body 71 constituting the ground following body, and the output changes according to the vertical swing angle of the rear cover 5.

FIG. 6 shows a block circuit diagram of the control mechanism 67, in which the target working depth (plowing depth) set by the plowing depth setting device 9 is given to the rotary neutral signal converter 75. The rotary neutral signal converter 75 converts an output signal corresponding to the angle of the rear cover 5 as a ground follower proportional to the target working depth (plowing depth) set by the plowing depth setting device 9 into a depth setting error detector. Give to 77. The depth setting error detector 77 detects a plowing depth error by comparing the output signal given from the rotary neutral signal generator 75 and the output signal given from the potentiometer 7 as an actual working depth detection sensor. Then, an output signal corresponding to this plowing depth error is given to the position signal converter 79. The position signal converter 79 adds the output signal given from the depth setting error detector 77 to correct it to an output signal of the target working depth, and supplies it to the motor control circuit 81 . The motor control circuit 81 includes a potentiometer 6 that detects the rotational position of the electric motor 57.
Based on the output signal given from the depth error detector 77 and the output signal given from the depth error detector 77, it is determined whether the electric motor 57 needs to be rotated forward, reversed, or maintained stopped. The electric motor 57 is driven in forward or reverse rotation by the output signal from the motor control circuit 81, and the lift arm 15 is automatically controlled to ascend and descend rapidly.

The rising position signal generator 83
It is activated when the automatic changeover switch 65 is set to the ascending side SW-B, and drives the electric motor 57 to the ascending position.

The delay circuit 11 includes a rise-automatic changeover switch 65.
When the switch 85 is switched from the rising side SW-B to the automatic side SW-A, the switch 85 is connected to the delay circuit 11 and activated for a set time, e.g., t seconds, set in the timer circuit 13, and the position signal converter The signal output from 79 is delayed and applied to motor control circuit 81 . Therefore, the output signal from the motor control circuit 81 is delayed, the electric motor 57 rotates slowly, and the lift arm 15 slowly descends within the set time. When the set time set in the timer circuit 13 has elapsed, the switch 85 automatically switches to the motor control circuit 81, stops the operation of the delay circuit 11, and switches to automatic elevation control for rapid descent. ing.

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

Rise - set the automatic changeover switch 65 to the rise side SW-A
After operating the ground work device 3 to raise it to the upper limit position, switch the raise-automatic changeover switch 65 to the automatic side SW-B to enter the automatic raising/lowering control state, and the settings set in the timer circuit 13 The delay circuit 11 operates for a time period of, for example, t seconds, and the output signal applied from the position signal converter 79 to the motor control circuit 81 is delayed. Therefore, the signal output from the motor control circuit 81 to the electric motor 57 is delayed, and the signal output from the motor control circuit 81 to the electric motor 57 is delayed.
7 rotates at a slow speed within a set time. Due to the slow rotation of the electric motor 57, the hydraulic cylinder 17
The piston 19 of will slowly retreat,
As the piston 19 of the hydraulic cylinder 17 is driven, the lift arm 15, which is driven up and down via the lift shaft 21, slowly descends. As the lift arm 15 slowly descends, the ground work device 3 slowly descends within the set time. In this case, the setting time of the timer circuit 13 is set to the descending time required for the ground working device 3 to reach the set plowing depth position from the upper limit position, and the lowering until reaching the arbitrary set plowing depth position is performed slowly. It can be a rapid descent.

In this way, once the ground work device 3 reaches the set plowing depth position, that is, once the set time of the timer circuit 13 has elapsed, the operation of the delay circuit 11 is automatically stopped, and the position signal converter 79 The output signal is directly given to the motor control circuit 81, and the motor control circuit 8
The electric motor 57 rotates at a rated speed based on the output signal from the motor 1. Due to the rated rotation of the electric motor 57, the piston 19 of the hydraulic cylinder 17 is activated rapidly, and the ground work device 3 is controlled to be automatically raised and lowered via the lift arm 15 to rapidly lower. Therefore, when the ground working device 3 is lifted by forward tilting of the tractor 1, and this is detected by the sensor 7 and descending control is performed, the plowing depth is quickly corrected by the rapid descent, and the remaining tillage is reduced. decreases.

As explained above, according to the present invention, when the switching device switches the rotary work machine to the downward movement side, the descending speed when the rotary work machine is lowered is slow until it reaches near the ground, and when the rotary work machine is lowered, the descending speed is slow until it reaches near the ground. We have installed a control means that speeds up once the rotary work machine approaches the ground, so the rotary work machine is controlled at a slow speed until it reaches near the ground, so there is less impact when the rotary lands and it prevents douching. After reaching near the ground,
Since the descending speed becomes faster, the time required to reach the target plowing depth is shortened, and the headland in the uncultivated area can be made smaller.

Note that this invention is not limited to the above-mentioned embodiments, and the invention can be implemented in modes other than the above-mentioned embodiments.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, and FIG. 1 is a side view of a riding-type tiller in which a rotary tiller, which is an example of a ground work device, is attached to a tractor, and FIG. 2 is a diagram showing the essentials of the lifting position adjustment mechanism. Sectional longitudinal side view, 3rd
The figure is a longitudinal rear view of the main part of the lifting position adjustment mechanism, Fig. 4 is a sectional view taken along the - line in Fig. 3, Fig. 5 is a side view of the main part showing the relationship between the sensor and the ground follower, and Fig. 6 is a block circuit diagram of the control mechanism. 1...Tractor, 3...Rotary work machine, 5...
... Ground follower, 7 ... Plowing depth sensor, 9 ... Plowing depth setting device, 11 ... Delay circuit, 13 ... Timer circuit, 17 ... Hydraulic cylinder, 23 ... Switching valve, 5
7...Electric motor, 65...Rise-automatic changeover switch.

Claims (1)

[Scope of Claims] 1. A rotary working machine connected to the rear body of a tractor, a drive mechanism for raising/lowering the rotary working machine at a preset speed on the tractor side, and a rotary working machine on the rotary working machine side. A detecting means for detecting the plowing depth of the rotary working machine is provided, and the tractor side has a setting means for setting the plowing depth of the rotary working machine, and a switching device for switching between raising and lowering the rotary working machine, When the switching device switches the rotary work machine to the lowering side while the rotary work machine is supported in the air, the speed at which the rotary work machine is lowered is lowered until it reaches near the ground. A tractor characterized by being provided with a control means that slows down and speeds up after approaching the ground.