JPH0626073A - Automatic control method for construction machine - Google Patents

Abstract

PURPOSE:To enhance the workability at a slope by compensating the angle and the height of a bucket with values corresponding to a vehicle inclination angle in accordance with output signals from a bucket posture detecting means and a vehicle inclination angle detecting means. CONSTITUTION:In the case of excavation at a slope having a down-grade, a controller 16 receives a vehicle inclination angle detected by an inclination sensor 15, and then carries out determination in accordance with this received signal, and a boom cylinder 8 is extended in the vicinity of the terminating point of one cycle of automatic excavation. Then, a boom 4 is rotated upward by a predetermined angle. Further, the position of a bucket base end pin P is shifted upward by a length H1, and the opening of a bucket 6 is set to be substantially horizontal. Further, in the case of excavation at a slop having an up-grade, a bucket cylinder 10 is extended similarly, and the rotation of the bucket 6 is adjusted so as to set the opening face thereof to be substantially horizontal. With this arrangement, it is possible to prevent insufficient lift-up of the bucket and dropping of a load.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control method for an automatic excavation operation of a construction machine such as a hydraulic excavator or a work vehicle.

[0002]

2. Description of the Related Art FIG. 6 is a side view showing a backhoe type hydraulic excavator. In the figure, 1 is an upper revolving structure,
2 is a lower traveling body, 3 is a work attachment mounted on the front part of the upper swing body 1, 4 is a boom, 5 is an arm, 6
Is a bucket, 7 is a bucket link, 8 is a boom cylinder, 9 is an arm cylinder, 10 is a bucket cylinder, 1
Reference numeral 1 is a boom angle sensor (constituting a bucket attitude detecting means) that detects a rotation angle of the boom 4 with respect to the main body of the upper swing body 1, and 12 is an arm angle sensor (bucket attitude detecting means) that detects a rotation angle of the arm 5 with respect to the boom 4. , 13 is a bucket angle sensor for detecting a rotation angle of the bucket 6 with respect to the arm 5 (constitutes a bucket attitude detecting means), and 14 is a cylinder pressure sensor for detecting a cylinder pressure of a bottom side oil chamber of the bucket cylinder 10 (action). Force detection means), 15 is an inclination angle sensor for detecting a vehicle body inclination angle, 16
Is a controller, 0 is a boom base end pin which is the center of rotation of the boom 4, P is a bucket base end pin, and Q is a bucket tip part.

In the hydraulic excavator shown in FIG. 6, a work attachment 3 in which a boom 4, an arm 5 and a bucket 6 are sequentially connected to each other so as to be rotatable in the front-rear direction is attached to a front portion of an upper revolving structure 1, and a bucket attitude detecting means. A boom angle sensor 11, an arm angle sensor 12, a bucket angle sensor 13, and a tilt angle sensor 15 which is a vehicle body tilt angle detecting means, and a controller 16 performs arithmetic processing based on output signals from these detecting means. The automatic excavation is performed by controlling the bucket rotation drive and the bucket lifting drive.

[0004]

At the time when the hydraulic excavator performing automatic excavation ends one excavation cycle, as shown in FIG. 6, earth and sand are sufficiently scooped into the bucket 6 before dumping. There is. In this state, the opening surface of the bucket 6 connecting the bucket base end pin P and the bucket tip Q is substantially horizontal, and the height from the boom base end pin O to the opening surface of the bucket 6 is a predetermined height. It is set to become HO. However, at the work site, the ground (G
L) is not horizontal and is often a sloping ground. FIG. 7: is a side view which shows the state which the hydraulic excavator of a prior art complete | finished 1 excavation cycle in the slope. When the vehicle body inclination angle is a downward inclination (the inclination angle is k) as shown in FIG. 7, the height of the bucket base end pin P is lower than the height of the boom base end pin O by a dimension H1. To do. For this reason, the lifting height of the bucket (6) at the end of one excavation cycle of automatic excavation was insufficient, or the bucket was tilted and spilled. It is an object of the present invention to provide an automatic control method that can solve the above problems.

[0005]

According to the automatic control method of the present invention, when the bucket is retracted and the bucket tip returns to a predetermined position when one excavation cycle in the automatic excavation operation is completed, the bucket attitude is detected. Based on the output signals from the means and the vehicle body inclination angle detection means, the controller outputs a command signal to the boom cylinder via the electro-hydraulic converter, so that the bucket lifting height and the bucket angle are matched with the vehicle body inclination angle. I tried to correct only the amount. Further, when the vehicle body inclination angle is an upward slope, the controller sends a command signal to the bucket cylinder via the electro-oil converter based on the output signals from the bucket attitude detection means and the vehicle body inclination angle detection means. By outputting it, the bucket angle is corrected by an amount commensurate with the vehicle body inclination angle.

[0006]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 is a circuit diagram of essential parts of a hydraulic excavator that enables the automatic control method of the present invention. In the figure, the same reference numerals are given to those using the same constituent elements as those in the prior art. Reference numerals 17, 18, and 19 denote boom, arm, and bucket hydraulic remote control valves (the hydraulic remote control valves can be operated in the front, rear, left, and right cross directions, but are shown separately for convenience of description), 20 , 21, 22 are pilot switching valves 23, ..., which are directional switching valves, respectively.
28 is a shuttle valve for selecting pilot pressure, 2
9, to 34 are electromagnetic proportional pressure reducing valves which are electro-oil converters respectively, 35 is a main pump, 36 is a pilot pump, 3
Reference numeral 7 is a controller, and 38 is an automatic / manual selection switch. FIG. 2 is a side view showing a state in which the hydraulic excavator according to the present invention has completed one excavation cycle of automatic excavation on a horizontal ground. In the figure, L0 is the distance from the boom base end pin 0 to the bucket base end pin P.

FIG. 3 is a side view showing a case where the hydraulic excavator according to the present invention works on a sloping ground having a downward slope (inclination angle b) toward the front. In FIG. 3, XX is a horizontal X axis with the boom base end pin 0 as an origin, YY is a vertical Y axis, and 6A indicated by a virtual line is one excavation cycle in the case of the conventional technique. Bucket position at time point, P
B is the pin position of the base of the bucket. First, the first aspect of the present invention
An example automatic control method will be described with reference to FIGS. When the hydraulic excavator performs automatic excavation on a sloping ground having the vehicle body forward tilt angle b, the vehicle body tilt angle detected by the tilt angle sensor 15 is input to the control 16. The controller 16 makes a determination based on the detection signal, and outputs a command signal to the electromagnetic proportional pressure reducing valve 29 when approaching the end point of one excavation cycle of automatic excavation. The pilot switching valve 20 is switched and the boom cylinder 8 is extended. The boom 4 is rotationally adjusted by an angle b in the direction of arrow B. The position of the bucket base end pin P is set to the dimension H1 as the boom 4 is rotated.
(Here, H1 = LO * sina + LO * sin [ba]) is adjusted and moved to the upper position, so that the height of the bucket base end pin P is set to the required height Hy and the opening surface of the bucket 6 is substantially horizontal. It can be put into a state and terminated.

FIG. 4 is a view showing the height correction of the bucket base end pin P at the end of one excavation cycle in FIG. Next, a second embodiment automatic control method of the present invention will be described with reference to FIG. When the hydraulic excavator performs automatic excavation on a sloping ground where the vehicle body has a full tilt angle b, if the boom base angle is simply corrected by the angle b when adjusting the bucket base end pin position at the end of one excavation cycle, The end pin position moves from position P to position P ′. Therefore, the relative amount in the height direction from the boom base end pin O to the bucket base end pin P is displaced by the dimension dy. Therefore, if Δh is calculated as the height direction correction amount in FIG. 4, the position of the bucket proximal end pin P can be accurately set. That is, the distance from the boom base end pin 0 to the bucket base end pin P in the X-axis direction is J, OP, and slope (GL).
If the angle formed by and is C, then J = L0 * cos (b-
c), .DELTA.h = LO * sin (bc) + J * tanC can be calculated to calculate the correction amount.

FIG. 5 is a side view showing a case where the hydraulic excavator according to the present invention works forward on a sloped ground having an upslope (inclination angle is + b). Next, a third embodiment automatic control method of the present invention will be described with reference to FIG. When the hydraulic excavator performs automatic excavation on a sloping ground having a vehicle body rearward inclination angle b, the vehicle body inclination angle detected by the inclination angle sensor 15 is input to the controller 16. The controller 16 makes a determination based on the detection signal, and outputs a command signal to the electromagnetic proportional pressure reducing valve 33 when approaching the end of one excavation cycle of automatic excavation. The pilot switching valve 22 is switched and the bucket cylinder 10 is extended. Since the bucket 6 is rotationally adjusted in the direction of arrow C, the bucket 6 is rotationally adjusted in the direction of arrow C, so that the opening surface of the bucket 6 can be brought to a substantially horizontal state and the operation can be ended.

[0010]

When a conventional hydraulic excavator designed to perform automatic excavation works on a horizontal ground, the bucket opening is performed at the end of one excavation cycle so as to prevent spilled dirt and sand. The surface is set to be horizontal. For this reason, when the hydraulic excavator performs work on a sloping ground, the bucket lifting height at the end of one excavation cycle is insufficient, or the bucket is tilted to cause spillage. However, in the automatic control method of the present invention, when the bucket retracts and the bucket tip returns to a predetermined position when one excavation cycle during the automatic excavation operation ends, the bucket attitude detection means and the vehicle body inclination angle detection means are described. Based on the output signal from the controller, the controller outputs a command signal to the boom cylinder via the electro-hydraulic converter so that the lifting height of the bucket and the bucket angle are corrected by an amount corresponding to the vehicle body inclination angle. . Further, when the vehicle body inclination angle is an upward slope, the controller sends a command signal to the bucket cylinder via the electro-oil converter based on the output signals from the bucket attitude detection means and the vehicle body inclination angle detection means. By outputting it, the bucket angle is corrected by an amount commensurate with the vehicle body inclination angle.
As a result, when the hydraulic excavator works forward on a slope with a downward slope, correction is made at the end of one excavation cycle to compensate for the slope to ensure the lifting height of the bucket and the opening surface of the bucket. Can be leveled to prevent spills. In addition, when the hydraulic excavator is working on a slope with an upward slope, the tip of the work attachment faces considerably upward, so lifting height is not corrected and the opening surface of the bucket is kept horizontal to prevent spillage. be able to. Therefore, the automatic control method of the present invention can improve the automatic excavation function and workability of the construction machine.

[Brief description of drawings]

FIG. 1 is a circuit diagram of a main part of a hydraulic excavator that enables an automatic control method of the present invention.

FIG. 2 is a side view showing a state in which the hydraulic excavator according to the present invention has completed one excavation cycle of automatic excavation on a horizontal ground.

FIG. 3 is a side view showing a case where the hydraulic excavator according to the present invention performs automatic excavation on a slope having a downward slope toward the front.

FIG. 4 is a diagram showing the height correction of the bucket base end pin at the end of one excavation cycle in FIG.

FIG. 5 is a side view showing a case where the hydraulic excavator according to the present invention performs automatic excavation on a slope having an upward slope toward the front.

FIG. 6 is a side view showing a hydraulic excavator.

7 is a side view when the hydraulic excavator in FIG. 6 is performing automatic control according to the related art on a slope having a downward slope toward the front. FIG.

[Explanation of symbols]

 3 Work Attachment 4 Boom 5 Arm 6 Bucket 8 Boom Cylinder 10 Bucket Cylinder 11, 12, 13 Angle Sensor 15 Tilt Angle Sensor 16, 37 Controller 17, ~, 19 Hydraulic Remote Control Valve 20, ~, 22 Pilot Switching Valve 29, ~, 34 Electromagnetic proportional pressure reducing valve O Boom base end pin P Bucket base end pin Q Bucket tip

Claims (2)

[Claims] 1. A work attachment, in which a boom, an arm, and a bucket are sequentially connected to each other so as to be rotatable in the front-rear direction, is attached to a front portion of a vehicle body, and a bucket posture detecting means and a vehicle body inclination angle detecting means are provided, and these are detected. In a construction machine configured to perform automatic excavation by controlling bucket rotation drive and bucket up-and-down drive based on an output signal from the means, when one excavation cycle at the time of automatic excavation operation is completed, the bucket rotates retract. When the bucket tip returns to a predetermined position, by outputting a command signal to the boom cylinder from the controller via the electro-oil converter based on the output signals from the bucket attitude detection means and the vehicle body inclination angle detection means, Correcting the bucket lift height and bucket angle by an amount that matches the vehicle body tilt angle A featured automatic control method for construction machinery. 2. The automatic control method for a construction machine according to claim 1, wherein when the vehicle body inclination angle is a climbing slope toward the front, the bucket posture detecting means and the vehicle body inclination angle detecting means are used. Based on the output signal, the controller outputs a command signal to the bucket cylinder via the electro-hydraulic converter to correct the bucket angle by an amount commensurate with the vehicle body inclination angle. Automatic control method.