JPH07213109A - Lifting apparatus for working machine of tractor - Google Patents

Abstract

PURPOSE:To obtain a lifting apparatus effective for facilitating the operation, stabilizing the lifted and lowered positions of a working machine and ensuring the safety by automatically lifting a tractor working machine in gyration and carrying out the lowering of the machine immediately after the lifting motion by the instruction by an operator. CONSTITUTION:This lifting apparatus for a working machine of a tractor detects the gyrating motion by a steering sensor 2 detecting the steering angle of a steering wheel 1, lifts a lift arm 3 to a preset lifted position and performs the following lowering output when the control lever 4 for position setting approximately coincides with the lift arm 3 or the lowering instruction is inputted by a manual lifting and lowering operation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a work implement lifting device for a tractor, which facilitates the lifting and lowering operation of the work device when turning around a ridge.

[0002]

2. Description of the Related Art In order to facilitate the operation during turning, there is a technique for automatically raising a lift arm by turning operation and automatically lowering it when going straight from turning. However, it is difficult for the operator to set the timing for descending the work machine, and the headland is often widened or the field is roughened. The present invention eliminates such a defect.

[0003]

According to the present invention, a steering sensor 2 for detecting a steering angle of a steering wheel 1 detects a turning operation to raise a lift arm 3 to a set position, and a subsequent descending output, The working machine lifting device for a tractor is configured so that the position setting control lever 4 and the lift arm 3 are substantially aligned with each other, or a lowering command is issued by a manual lifting operation.

[0004]

[Advantageous Effects of the Invention] When the tractor shifts from the straight-ahead working state to the turning by the turning steering of the steering wheel 1, the steering sensor 2 detects the turning steering, and the lift arm 3 is set in advance. It is raised to the position and is in a non-working posture. When the turning ends and the process goes straight, the control lever 4 is operated, or
The lifting arm 3 is moved downward by another lifting operation to lower the working machine to the working position. Of these, when the control lever 4 is operated, the position set by the operation of the control lever 4 substantially coincides with the lift arm 3, and a lowering command is issued to lower the lift arm 3. Further, when a lowering command is issued by any other manual operation of raising and lowering, the lift arm 3 is lowered by this.

As described above, in the turning stroke, the lift arm 3 can be automatically raised by the steering angle of the steering wheel 1. However, when the lift arm 3 is lowered, it is manually operated by the operator. The operation at the time of operation can be simplified, the timing of the descending operation can be easily set, and the work start and end positions can be easily aligned. In addition, safety is improved without suddenly descending during the inspection of the working machine.

[0006]

EXAMPLE A truck body 11 has an engine under a hood 12 mounted at a front portion thereof, has front wheels 13 steered by a steering wheel 1, and has rear wheels 14 at a rear portion thereof, which are driven by the engine. It is driven by four-wheel drive. On the rear mission case 15, there is a cockpit 17 between the left and right hunders 16, a lift arm 3 which is vertically rotated by hydraulic pressure from a hydraulic cylinder, and a power take-off shaft PTO on the rear side. .

A rotary tiller 20 is movably connected to the rear portion of the vehicle body 11 by a pair of left and right lower links 18 and a top link 19, and a lift arm 3 and the left and right lower links 18 are lifted. By connecting with the rod 21, the working machine 20 can be lifted and lowered as a three-point link mechanism by vertically rotating the lift arm 3. Reference numeral 22 is a tilling claw, and 23 is a flat plate, which has a function of a tilling depth sensor.

An operating mechanism is provided on one side of the cockpit 17, and a control lever 4 for raising and lowering the lift arm 3 and a raising position dial for setting the raising position of the lift arm 3 as a target value. 8. The automatic lift switch 5 for selecting the mode in which the rotary tiller 20 is automatically raised to the height set by the raising position setting dial 8 when turning, the lift arm 3 is manually operated regardless of other operations. It has a finger-up lever 7 for raising and lowering by switching.

A potentiometer for setting a position is provided at the base rotation portion of the control lever 4,
While comparing the set value set by this potentiometer with the detected value of the lift arm sensor 6 of the lift arm 3, the lift arm 3 controls the controller CPU having the microcomputer 4 so as to match the operation position of the control lever 4. After that, the solenoid valves 9 and 10 for ascending or descending are output to move up and down.

The raising position dial 8 sets the raising limit position of the lift arm 3 and indicates the raising stop position of the lift arm 3 when the raising arm 3 is controlled to rise. . The steering sensor 2 is composed of a potentiometer or the like for detecting the operation cut angle of the steering wheel 1, and can detect each of the cut angle positions θ1 to θ3 as shown in FIG. 4 and input them to the controller CPU.

An example will be described in which the automatic lift switch 5 is turned ON and the work is carried out by the rotary tiller 20 while traveling in a reciprocating stroke in the field. As shown in FIG. 2, when the automatic lift switch 5 is turned on and it is detected that there is a turning operation by the steering wheel 1,
Immediately after this, the raising mode is set, and the raising mode is raised to the position where the set value by the control lever 4 and the lift arm angle by the lift arm sensor 6 match. At this time, if there is an input signal from the finger-up lever 7 while the lift arm angle does not match the set value by the control lever 4, this is followed.

For position control, the lift target value set by the lift position dial 8 as shown in FIG. 3 and the detection value detected by the lift arm sensor 6 are compared to each other to raise or lower the solenoid. The valves 9 and 10 are output. At this time, when the position set value by the control lever 4 is higher than the set value by the raising position dial 8, the lift target value of the lift arm 3 is set by the raising position dial 8, and conversely When the position set value by the lever 4 is lower than the set value by the raising position dial 8, this control lever value is set as the target value of the lift arm 3.

The timing for raising the rotary working machine at the time of turning needs to be swiftly set by entering the turning operation. Therefore, when the rotary working machine is configured to be lifted only by detecting the steering angle, the rotary working machine may be lifted as a corner that is not a turning corner due to a false detection in a deformed field. Further, in the configuration in which only the steering operation angle is detected to make a turn, a problem arises in which the turning operation cannot be detected when the vehicle is operated at a slow speed and the tractor is almost stopped every time the work end is reached.

As shown in FIGS. 1 and 2, when the steering operation angle is equal to or greater than a certain value or the steering operation speed is equal to or greater than a certain value, it is detected that a turning operation is performed.
By setting the zone that determines by detecting these operating speeds and the zone that determines only by the cutting angle, the above problems will be eliminated, and the plowing work and slow turning at the corner will be eliminated. And so on.

As shown in FIG. 4, cutting angles θ1, θ2, θ3 from the neutral position N of the steering wheel 1 in the left-right direction are defined as straight-running zones A for straight-ahead steering between the turning angles N-θ1 and the turning angles θ1-. A turning operation speed zone B is set between θ2 and a turning operation is performed when the operation speed V of the steering wheel 1 is equal to or more than a predetermined value. A turning operation angle zone B is set between the turning angles θ2 and θ3. Set as the maximum corner zone C.

As a result, as shown in FIG. 5, when the steering angle of the steering wheel 1 is in the maximum steering angle zone C, the turning operation presence flag is set, but when it does not reach the maximum steering angle zone C, the steering angle sensor is set. Is in the operation speed zone B and the speed V of this turning angle is higher than the specified speed, the flag set with turning operation is set. Therefore, even if the cutting angle is in the operation speed zone B, if the speed V is slow, the turning operation is not performed, and the tiller is not raised,
Continue tilling. Further, when the turning operation is set in this way, the automatic raising of the rotary working machine is effective only immediately after the detection of the turning operation, and the straight traveling state is returned by detecting the turning angle of the straight traveling zone A for a certain time. The flag indicating that the turning operation is performed is cleared, and turning and lifting of the working machine are canceled. Therefore, even when the turning operation is almost completed and the steering 1 state near the rotary working machine lowering timing is unstable, the rotary working machine is once lowered and is raised again without being falsely detected as having the turning operation. It is possible to prevent the occurrence of such a defect.

[Brief description of drawings]

FIG. 1 is a block diagram of work machine lifting control.

FIG. 2 is an automatic raising control flowchart.

FIG. 3 is a flowchart of position control.

FIG. 4 is an operation diagram showing a steering angle.

FIG. 5 is a flowchart of turning operation control.

FIG. 6 is a side view of the tractor.

[Explanation of symbols]

 1 Steering 2 Steering sensor 3 Lift arm 4 Control lever

Claims (1)

[Claims] 1. A steering sensor 2 for detecting a steering angle of a steering 1 detects a turning steering to raise a lift arm 3 to a set position, and a subsequent descending output to a control lever 4 for setting a position. A work implement lifting device for a tractor, which is configured to be substantially in agreement with the lift arm 3 or to be lowered by a lifting manual operation.