JPS634128A - Automatic control of blade tilt excavation - Google Patents

Abstract

PURPOSE:To always control a car body to run to a target, by detecting a difference between the target running direction and the actual running direction, based on a ground speed on the left and right crawlers, and by controlling the tilt degree and the operating direction to compensate the difference. CONSTITUTION:A car body 1 is provided with Doppler sensors 19 for detecting a ground speed on left and right crawlers 7, 7, and a car body inclinometer 20, and to a truck frame 2, one side of a blade arm 15 is connected, and to a blade 16, a tilt cylinder 17 is connected, and to the blade 16 and the car body 1, blade cylinders 18, 18 are connected. By the left and right Doppler sensors 19, 19, the ground speed on the left and right crawlers 7, 7, is detected, and by a main controller 30, an arithmetic on the actual running direction is performed. Besides, in case that there is a difference between the direction and the target running direction, operating direction signal is generated from controllers 24, 29, and a clutch and a brake 12 are applied, and the ground speed on the crawlers 7, 7 is controlled, and the tilt cylinder 17 is expanded or contracted, and the actual running direction is corrected.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an automatic control method when tilting the blade of a bulldozer to perform tilted excavation such as root cutting and excavation.

Conventional technology When excavating roots by tilting the blade, the tilt cylinder is extended and contracted to tilt the blade to the right or left, and the right or left side of the blade penetrates into the ground to drive the left and right tracks of the bulldozer. is moving forward.

Problems to be Solved by the Invention Since the load acting on the blade during root cutting and excavation described above is often biased to either the right or left side, the actual running direction of the bulldozer deviates from the target running direction. The bulldozer senses the actual running direction and operates the operating lever to control the left and right steering clutches and brakes, and operates the lever to control the tilt cylinder so that the bulldozer moves in the target running direction. I have to.

For this reason, the operator must perform detailed and complex operations as described above, and the operator is required to be highly skilled.

Means and action for solving the problem The deviation between the target running direction and the actual running direction is detected based on the difference in ground speed between the left and right crawlers, and in order to compensate for this deviation, the amount of left or right tilt of the blade and left/right control are adjusted. The vehicle body can always be controlled in the target travel direction during blade tilt excavation, making operation easier.

A pair of track frames 2゜2 are mounted on both sides of the vehicle body 1 so as to be relatively displaceable via an equal bar 3 and a diamond corner place 4, and each track frame 2 is connected to a crawler track via an idler 5 and a sprocket 6. 7 are respectively installed, and an engine 8 is mounted on the vehicle body 1, and its output side includes a torque converter 9, a transmission 10, a horizontal shaft 11,
The left and right sprockets are also connected to 6 via the left and right steering clutch/brake +2.12 and the final reduction mechanism 13.13.

Blade arms 15 are connected to the left and right track frames 2 via trunnions 14, and each blade arm 15 is connected to a blade 16,
A tilt cylinder 17 is connected between the - side blade arm 15 and the blade 16, and a pair of blade cylinders 18 and 18 are connected between the blade 16 and the vehicle body 1, respectively.

The vehicle body 1 is provided with sensors for detecting the rotational speeds of the left and right tracks 7, 70 and the ground speed of the claws, such as a Doppler sensor 19, as well as a vehicle body inclinometer 20.

This is a conventionally known system that is controlled by supplying pressure oil from the left and right steering clutches and brakes + 2d pump 21 to left and right clutch valves 22 and brake valves 23, and each clutch valve 22 and brake valve 23 is a solenoid. 22! , 23G are excited and demagnetized using a signal from the controller 24, and the controller 24 is provided with an operating lever 25.

Said tilt cylinder +7r! The blade 16 is extended and retracted by supplying pressure oil from the pump 26 with the operation valve 27, and when it is extended, the blade 16 tilts to the left (the left side goes down), and when it contracts, it tilts to the right (the right side goes down). and the first and second solenoids 27. , 27. When energized, the first and second solenoids 27+, :' are switched from the neutral position N to the first position 11 and the second position L.
7z is designed to be magnetized and demagnetized by a controller 29 equipped with a lever 28.

Said left and right Doppler sensors I'? , +9 and body inclinometer 2
A detected value of 0 is input to the main controller 3o, which outputs a control signal to the controllers 24 and 29.

The main controller 30 calculates the deviation angle θ of the actual running direction x2 from the target direction x1 of the vehicle body per time based on the following equation.
Calculate.

However, V, , V1Fi left and right crawler tracks 7, 7 ground speed, B
The distance between the left and right crawler tracks 7, 7, and t is time. (5th
(See figure) Then, a control signal is output to the controllers 24 and 29 based on the calculated deviation angle θ.

Note that the main controller 30 has an automatic manual changeover switch 31.
The above-mentioned operation is carried out when switching to automatic mode, and no operation is performed when switching to manual mode. The control signal from the operation is given priority.

Next, a control method for cutting and excavating roots by tilting the blade 16 to the left or right will be described.

First, switch the automatic manual changeover switch 31 to manual and operate the operating lever 25 and lever 28 to move the tilt cylinder 17.
The blade 16 is tilted to the left or right by extending or contracting, and the vehicle body 1 is directed toward the target running direction.

Then, the automatic/manual changeover switch 31 is switched to automatic to perform root cutting and excavation.

At this time, the ground speed of the left and right crawlers 7, 70 is detected by the left and right Dotsupura sensors 19, 19, and the main controller 30
The actual running direction is calculated and it is determined whether the actual running direction is shifted to the right or left with respect to the target running direction.

If the deviation is to the right, the main controller 30 sends a left steering signal to the controllers 24 and 29, that is, a signal that disengages and brakes the left steering clutch/brake 12 and slows down the ground speed of the left crawler track 7. and a left tilt signal, which is a signal that excites the first solenoid 271 to contract the tilt cylinder 17, thereby changing the actual running direction to the left.

If the deviation is to the left, the main controller 30 sends a right steering signal to the controllers 24 and 29, that is, a signal to disengage and brake the right steering clutch/brake 12 to slow down the ground speed of the right crawler track 7. The right tilt signal, that is, the second solenoid 27. to extend the tilt cylinder 17. Outputs a signal to excite the motor and changes the actual running direction to the right.

Thereafter, the above-mentioned operation is repeated at regular intervals to remove the blade 16.
Automatically controls the actual running direction of the vehicle body 1 to always match the target running direction by controlling the left/right tilt amount of the blade 16 and the 7.70 ground speed difference between the left and right crawlers in accordance with changes in the magnitude of the load acting on the do.

The above operation is shown in a flowchart as shown in FIG.

In addition, strain gauges are installed on the left and right trunnions 14, 14 to measure stress, and the balance between the left and right loads on the blade 16 is determined by the main controller 30. The blade tilt signal and the left and right steering signals may be output based on the unbalance of the left and right loads of 16.

In addition, the vehicle body inclinometer 20 detects the left and right tilt of the vehicle body 1, and this is detected using a potentiometer! The fi signal may be input to the main controller 30 to control the left and right tilt amount and the left and right steering based on this vehicle body inclination.

When the amount of left and right tilt increases, the left or right side of the blade 16 penetrates deeply into the ground and the right or left crawler tracks 7, 7 rise up, so the ground speed of the left and right tracks is different, so Accurate table control cannot be achieved only with the difference in ground speed, so this difference in ground speed between the left and right crawlers is corrected by the inclination of the vehicle body to achieve accurate control.

Effects of the Invention When excavating by tilting the blade, the running direction of the vehicle body can be automatically controlled to the target running direction, and the operation of the excavating work can be simplified.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, and Fig. 1 is a plan view of a bulldozer, Fig. 2 is a steering control circuit diagram, Fig. 3 is a tilt cylinder control circuit diagram, Fig. 4 is a control circuit diagram, and Fig. 5 is a diagram. 6 is a plan view of the tilt excavation state, and FIG. 6 is an operation flowchart. l is the vehicle body, 7 is the track, and 1 is the blade.

Claims (1)

[Claims] A deviation between the target running direction and the actual running direction is detected based on the difference in ground speed between the left and right crawler tracks 7, 7, and the left or right tilt amount and left/right steering of the blade 16 are controlled to compensate for this deviation. An automatic control method for blade tilt excavation, characterized in that: