JPH0249504A - Control device of working machine in agricultural tractor - Google Patents

Abstract

PURPOSE:To obtain the subject device without mistaken signal and capable of tilling with suitable tilling depth by providing incline detecting mechanism at rotary cover side in working machine and linking oil pressure cylinder connected to rolling control valve and depth control mechanism. CONSTITUTION:Depth is detected by a rear cover 44 and a level 87 is provided at the side of rotary cover 43 of working machine, then inclination is detected independently of the rear cover 44. A depth control mechanism performing feed back of detected result of the rear cover 44 to main control valve 11 and an oil pressure cylinder 37 for rolling operation connected to rolling control valve 14 are linked, then rolling and tilling depth are simultaneously and automatically controlled.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention is equipped with a hydraulic cylinder for raising and lowering a ground-based working machine relative to a tractor, as well as a hydraulic cylinder for rolling the working machine. The present invention relates to a work machine control device for an agricultural tractor suitable for carrying out such operations.

(Prior art and its problems) As a conventional tractor of this kind, for example,
0707, but the hydraulic cylinder 29 for rolling and the hydraulic cylinder 16 for lifting and lowering are manually operated, and are not structured to automatically maintain a horizontal posture etc. using an inclination detection mechanism or the like.

It also does not have a structure that can detect the plowing depth and automatically control the plowing depth.

In addition, there are tractors that only have a mechanism that detects the plowing depth and automatically controls the plowing depth, and work vehicles that only have a tilt detection mechanism that automatically horizontally controls the tilt of the work equipment. When plowing a field, it is difficult to uniformly plow the entire field at an appropriate plowing depth using only one of the automatic controls described above.

For example, when cultivating a field, in order to eliminate leftover cultivation,
It is necessary to drive the tractor along the boundary line between the soft cultivated land and the still hard uncultivated land. In such work, one wheel of the tractor, for example the right wheel, tends to fall into the soft cultivated land, and if it falls, the running handle must be turned in the opposite direction. To repeat this process, the tractor travels in a meandering manner. In other words, the machine travels while tilting forward and backward, left and right, and automatic control of only one of rolling and plowing depth is insufficient.

In addition, during reciprocating tillage, the tractor turns (turns) at the edge of the field, but at the turning place, there are holes after lifting the work equipment, holes cut by the inner wheel in the braking state, and convex parts on the outside of the turning by the wheels. In the case of headland processing, as mentioned above, the vehicle travels over uneven areas, so it has to travel while tilting forward, backward, left and right, and automatic control of only one of rolling and plowing depth is not enough. It is enough.

(Technical Means for Solving the Problems) In order to solve the above problems, the present invention includes a hydraulic cylinder 24 for lifting and lowering the ground work equipment relative to the tractor, as well as a hydraulic cylinder 37 for rolling the work equipment. , the hydraulic cylinder 37 for rolling operation is connected to the rolling control valve 14, and the hydraulic cylinder 24 for lifting is connected to the main control valve 11.
The rolling control valve 14 and the main control valve 11 are connected in parallel to the hydraulic pump side so that they can operate at the same time, and the rotary cover 43 side of the working machine has a tilting valve that sends a tilting signal to the rolling control valve 14. A detection mechanism is provided between the work machine and the main control valve 11, and a depth control mechanism is provided between the work machine and the main control valve 11 to measure the depth of the work machine by rotating the rear cover 44 and feed it back to the main control valve 11. When the rear cover 44 is rotated upward during rolling control in which the hydraulic cylinder 37 is extended, it is during rolling control in which the work equipment is raised and the hydraulic cylinder 37 for rolling operation is contracted. When the rear cover 44 is rotated downward, the hydraulic cylinder 37 and the depth control mechanism are linked to lower the working machine.

(Example) The first part including the left side portion of an agricultural tractor to which the present invention is applied
In the figure, a suction port 3 of a pump 2 driven by an engine 1 is connected to a strainer 6 in a tank 5 through an oil path 4.
The discharge lower of the pump 2 is connected to the inlet of a diversion valve 9 via an oil passage 8, and one outlet of the diversion valve 9 is connected to an inlet 12 of a main control valve 11 via an oil passage 10. The other outlet is connected to an inlet 15 of a Ro-rig control valve 14 via an oil line 13. Among the outlets 16, 17, and 18 of the main control valve 11, the outlet 16 communicates with the tank 5 through an oil passage 20 having a slow return valve 19, the outlet 17 communicates with the tank 5 through an oil passage 21, The outlet 18 passes through an oil passage 23 having a stop valve 22 to a working chamber 25 of a hydraulic cylinder 24 for driving the lift arm.
is connected to. An oil passage 27 having a safety valve 26 branches off from the middle of the oil passage 23, and the other end of this oil passage 27 communicates with the tank 5. 28 is a hydraulic pressure outlet.

The piston 30 fitted in the hydraulic cylinder 24 is the rod 3
1, and the lift shaft 33 to which the upper end of the lift crank 32 is fixed has a feedback arm 35 in addition to the left lift arm 34.
is attached, and the lift arm 34 is connected to the lift link 3.
6 and the left lower link 3 via the double-acting hydraulic cylinder 37.
It is connected to the center of 8. The front end (left end in the figure) of the lower link 38 is connected to a tractor main unit side bracket 40 via a bin 39 in the vehicle width direction, and the rear end is connected to a gear case 41. 42 is a rotor attached to the lower end of the gear case 41; 43 is a rotary cover that covers the rotor 42;
4 is a rear cover, and the rear cover 44 is attached to the opening cover 43 via a hinge 45 in the vehicle width direction. The rotor 42 digs into the uncultivated land 46 by a certain amount, and the rear end of the rear cover 44 elastically rests on the cultivated land 47 behind the rotor. 48 and 49 are pins in the vehicle width direction, and 50 is a piston provided at the lower end of the lift link 36;
is slidably fitted within the hydraulic cylinder 37, and its upper and lower working chambers 51,52 are connected to the inlet/outlet 55,56 of the rolling control valve 14 through oil passages 53,54, respectively.

The right lift arm 34' is connected to the right lower link 38' through five lift links 60 having tongue buckles 58 in the middle. The turnbuckle 58 has right-handed and left-handed screw holes at the top and bottom, and the lift link 5 is inserted therein.
9.60 are screwed together and are integrated by a lock nut 61.

A feedback rod 62 for position control is connected to the lower end of the feedback arm 35 via a pin in the vehicle width direction, and the front end of the rod 62 is connected to the control bar 6.
3 and provides a fulcrum for the bar 63. At the front of the upper end of the control par 63, there is a spring 65 that acts in the downward direction (reverse A direction) of the spool 64.
The front surface of the upper end of the bar 63 comes into contact with the cam 67 of the control lever 66. 68 is a tension spring connected to the upper end of the bar 63.

A feedback rod 70 for depth control attached above the rod 62 has its front end facing the control par 63 with a slight gap, and is supported slidably in the longitudinal direction by a guide mechanism (not shown). The rear end engages with the lower end of arm 71. The upper end of the arm 71 is swingably supported by a pin 72 extending in the vehicle width direction.
The front end of the wire 73 is connected to the midway portion, and the wire 73 extends rearward and downward from there, and is connected to the bracket 74 of the lower end pusher cover 44 via a pin in the vehicle width direction.

The outlet of the rolling control valve 14 communicates with the tank 5 through an oil line 77, and a bypass oil line 79 having a safety valve 78 connects the oil line 13.77.

The rolling control valve 14 includes switching solenoids 80, 81, which are connected to a controller 84 via signal lines 82, 83. The controller 84 has a built-in relay, and is connected to a level 87 mounted on the rotary cover 43 via signal lines 85 and 86. 88 is a battery.

The illustrated spirit level 87 is of a mercury type as shown in FIG.
-, with electrodes 90 and 90' connected to ground, and electrode 8
A signal line 85.86 is connected to 9.89'. When the spirit level 87 is horizontal, the internal mercury 91 is in the center of the container, and neither the left nor the right electrodes are connected. However, if the left side of the rotary cover 43 is tilted lower, the mercury 9
1 moves to the left as shown by the arrow and connects the electrodes 89 and 90.

FIG. 1 shows a neutral state in which the rotor 42 continues plowing at the plowing depth H instructed by the control lever 66, and since the rolling control valve 14 is in the neutral state, the left lift link 36 (cylinder 37 The length L of the right lift link 59.60 (also serving as a lift link) is equal to the length L' of the right lift link 59.60 (L-L-). When the control lever 66 is operated in the upward direction shown by arrow B from this state, the control lever 63 rotates clockwise about the rod 62, and its lower end pushes the spool 64 in the upward direction shown by arrow A. As a result, the main control valve 11 is switched to the left side in the figure, and the hydraulic oil that had previously flowed out from the inlet 12 to the outlet 17 side is switched from the inlet 12 to the outlet 18 side, and the hydraulic oil flows through the oil passage 23 to the hydraulic pressure. is supplied to the working chamber 25 of the cylinder 24,
The lift arm 34 rises, and the entire work machine rises. At that time, the length of the lift link, L-, remains unchanged.

As the lift arm 34 rises, the feedback rod 62 retreats, so the spool 64 moves in the downward direction (reverse A direction), and thereby the lift arm 34 converges to the position indicated by the control lever 66.

(Function) During work, the hydraulic oil discharged from the hydraulic pump 2 flows into the diversion valve 9, where it is branched into two hands, and from one outlet port is supplied to the main control valve 11 via the oil passage 10. , and is supplied to the rolling control valve 14 via the oil passage 13 from the remaining outlet ports.

During work, when the left side of the rotor recovery cover 43 becomes lower than the right side due to the rolling of the tractor body, the level 87 in FIG. electrode 89
．． 90 connects. This transmits a signal through line 85 to controller 84, which activates a relay to provide a raise signal from line 82 to solenoid 80. When the solenoid 80 is energized, the rolling control valve 1
4 is switched in the upward direction (direction of arrow A) against the elasticity of the spring, and the inlet 15 is connected to the entrance/exit 55, and the entrance/exit 56 is connected to the exit arrow, so hydraulic pressure is supplied to the working chamber 51, and the vertical position is fixed. The cylinder 37 rises relative to the piston 50,
The left side portion of the rotor 42 is raised via the left lower link 38. When the rotary cover 43 is in a horizontal position, mercury 9
1 leaves the electrodes 89, 90 and returns to the neutral position of FIG. As a result, the rolling control valve 14 returns to the neutral state shown in FIG. 1, and the oil pressure in the working chambers 51 and 52 is maintained.
The lift link length is a constant value that decreases (L-I=
L'). When the left side portion of the rotary cover 43 rises relative to the right side portion, L increases due to the opposite operation, and in this way, the working machine maintains its posture as horizontal as possible.

During the above-mentioned rolling control, if the plowing depth H increases beyond a certain value, the depth control feedback rod 70 moves forward in the direction of the arrow due to the counterclockwise movement of the roller cover 44 with the pin 45 as the fulcrum, and the spool 64 in the upward direction (arrow A), hydraulic pressure is supplied to the working chamber 25 regardless of the position of the control lever 66, thereby raising the entire working machine. Plowing depth H decreases and rear cover 44
When the rod 70 rotates clockwise about the bin 45, the rod 70 retreats in the direction of the opposite arrow and returns to the original position control state.

To explain the specific interlocking operation of rolling control and plowing depth control during tilling work, as shown in the figure, hydraulic cylinder 3
7 is placed on the left side, and if the right wheel falls into a depression and tilts to the right, automatic rolling control will operate and the hydraulic cylinder 37 will extend to become horizontal. In this horizontal state, the plowing depth H becomes excessive, but at the same time, the work equipment rear cover 44 is pushed up to the ground and rotated upward.
As a result, the working machine is raised by depth control control to return to the proper plowing depth state.

Conversely, if the right wheel runs onto the ground and the work machine tilts to the left, the hydraulic cylinder 37 contracts and becomes horizontal. In this state, the plowing depth H becomes too small, resulting in poor plowing, but at the same time, the work implement cover 44 is lowered, and the work implement can be lowered by depth control control to achieve an appropriate plowing depth.

Note that if the left wheel runs onto the ground, it will tilt to the right, and the hydraulic cylinder 37 will extend to control the work machine horizontally. Both cases are conceivable, but in either case, by rotating the plow cover 44 accordingly, the working machine can reach an appropriate plowing depth using depth control.

Also, if the left wheel falls into a depression, it will tilt to the left, and the hydraulic cylinder 37 will contract to control it horizontally. Both are possible, but in either case, the depth control allows the working machine to reach an appropriate plowing depth by rotating the shovel cover 44 accordingly.

(Another Embodiment) In the depth control mechanism of the illustrated embodiment, a wire 73 is used as a means for transmitting the rotation of the rear cover 44 to the feedback rod 70. For example, means may be provided to electrically detect rotation of the rear cover 44 and operate the feedback rod 70 by a predetermined amount using an actuator such as an electric motor.

The tilt detection mechanism can also be provided on the rotary cover 43 side, such as on the gear case 41 or a frame part on the rotary cover.

(Effects of the Invention) As described above, the present invention includes, in addition to the hydraulic cylinder 24 for raising and lowering the ground work equipment relative to the tractor, the hydraulic cylinder 37 for rolling the work equipment. is connected to the rolling control valve 14, the lifting hydraulic cylinder 24 is connected to the main control valve 11, and the rolling control valve 14 and the main control valve are connected in parallel to the hydraulic pump side so that they can operate simultaneously. A tilt detection mechanism is provided on the machine rear cover 43 side to send a tilt signal to the rolling control valve 14, and between the work machine and the main control valve 11, the depth of the work machine is measured by rotation of the rear cover 44 and the main control valve 14 is Hydraulic cylinder 3 for rolling operation is equipped with a depth control mechanism that performs phytoback on control valve 11.
7 is extended, and when the rear cover 44 is rotated upward, the work equipment is raised, and the rolling control hydraulic cylinder 37 is contracted, and the rear cover 44 is rotated upward. Since the hydraulic cylinder 37 and the depth control mechanism are linked to lower the working machine when the hydraulic cylinder 44 is rotated downward, there are the following advantages.

(1) When cultivating a field, when plowing adjacent land that involves running on the border between soft cultivated land and hard uncultivated land, or when clearing uneven headland, the tractor itself may move forward, backward, left or right due to falling or running over a wheel. Even when traveling on an incline, rolling control and plowing depth control work together to automatically control rolling and plowing depth at the same time, allowing the entire field to be tilled evenly at the appropriate plowing depth.

(2) Since the rear cover 44 is used as a depth control sensor and the tilt detection mechanism is provided on the rotary cover side of the work equipment, it is possible to avoid the influence of vibration of the rear cover 44 that rotates when it is in contact with the ground. As a result, false signals can be eliminated and a good tilt detection function can be achieved.

In general tractors, the right lift link 5
9. A turnbuckle 58 is installed in the middle of 60, and the left lift link beam foot arm 34 and lower link 3
8, it is easy to install the double-acting hydraulic cylinder 37 in the middle or end of the left lift link, and the double-acting hydraulic cylinder 37 and the right turnbuckle 58 can be used together. This increases the adjustment range and enables appropriate control. Instead of the mercury type level 87, a ball type or hanging cone type (scale type) level can also be used.

[Brief explanation of the drawing]

FIG. 1 is a schematic structural diagram including the left side portion of an agricultural tractor to which the present invention is applied, and FIG. 2 is an enlarged partial cross-sectional view taken along the line 1--2 in FIG. DESCRIPTION OF SYMBOLS 11... Main control valve, 14... Rolling control valve, 24... Hydraulic cylinder for lifting, 37... Double acting hydraulic cylinder for rolling, 70... Feedback rod for depth control, 87... Level patent applicant Yanmar Diesel Co., Ltd. agent Patent attorney Tadataka Omori [□-“1shi・--j

Claims (1)

[Claims] In addition to the hydraulic cylinder 24 for raising and lowering the ground work equipment relative to the tractor, the hydraulic cylinder 37 for rolling the work equipment is provided.
is connected to the rolling control valve 14, the lifting hydraulic cylinder 24 is connected to the main control valve 11, and the rolling control valve 14 and the main control valve 11 are connected in parallel to the hydraulic pump side so that they can operate simultaneously. A tilt detection mechanism that sends a tilt signal to the rolling control valve 14 is provided on the rotary cover 43 side of the work machine, and a mechanism that measures the depth of the work machine by rotating the rear cover 44 is provided between the work machine and the main control valve 11. It is equipped with a depth control mechanism that feeds back to the main control valve 11, and when the rear cover 44 is rotated upward during rolling control in which the hydraulic cylinder 37 for rolling operation is extended, the work machine is When the rear cover 44 is rotated downward during rolling control in which the hydraulic cylinder 37 for rolling operation is contracted, the hydraulic cylinder 37 and the depth control mechanism are activated to lower the work equipment. A work machine control device for an agricultural tractor, characterized by interlocking the following.