JPS6367331A - Excavation control device for hydraulic power shovel - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an excavation control device for a hydraulic power shovel.

[Conventional technology]

In general, a hydraulic power excavator includes a boom 1, an arm 2, a bucket 3, a boom cylinder 4, an arm cylinder 5, which are hydraulic cylinders that operate these, as shown in FIG.
It is equipped with a bucket cylinder 6, each hydraulic cylinder 4,
5.6 is operated by a control lever located in the driver's seat.

When excavating the ground with such a hydraulic power shovel, it is necessary to sequentially control the boom cylinder 4, arm cylinder 5, and bucket cylinder 6. By the way, the insertion angle ψ of bucket 3 with respect to the ground (see Figure 2)
The preferred angle differs somewhat depending on the excavated soil quality, but is set to a predetermined angle based on the maximum cutting force of the hydraulic power shovel. Second, during excavation work, the cutting edge of the bucket must be controlled so that it is always at a predetermined angle with respect to the ground. However, when controlling the cutting edge angle of the bucket of a hydraulic power shovel, three elements, the boom cylinder 4, the arm cylinder 5, and the bucket cylinder 6 described above, must be controlled.

Conventionally, as a method similar to the above-mentioned bucket edge angle control,
Some systems have a tilt angle detector such as a gyro or a pensulam installed in the bucket part 81, and the attitude angle of the bucket is controlled by the output of this tilt angle detector. It is unsuitable for controlling areas subject to severe impact and is impractical.

[Problem to be solved by the invention]

The present invention has been made in view of the above-mentioned practicality, and is an excavation control for a hydraulic power shovel that can withstand vibrations, shocks, etc., and can accurately control the insertion edge angle of the bucket relative to the ground to a predetermined angle! I device.

[Means for solving problems]

The excavation control device for a hydraulic power shovel of the present invention includes a boom,
a potentiometer disposed at each rotation fulcrum of the arm and the bucket; an arithmetic circuit that calculates the sum of the boom rotation angle, the arm rotation angle, and the bucket rotation angle from the output of the potentiometer; and the arithmetic circuit. a comparison circuit that compares the output of the bucket with a reference signal corresponding to the bucket edge angle; a detection means that detects that the bucket edge has contacted the ground; and a coincidence output of the comparison circuit and the detection means that both occur. and means for generating an excavation start signal instructing to start excavation under the condition.

(Function) In the present invention, the excavation work is started on the condition that the cutting edge angle of the bucket with respect to the ground becomes a desired angle and the tip of the bucket contacts the ground, and the bucket is inserted into the ground. The cutting edge angle is precisely controlled.

〔Example〕

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

In FIG. 3, if the rotation angle of the boom 1 is α, the rotation angle of the arm 2 is β, and the rotation angle of the bucket 3 is γ, then the following relational expression is established between the angle of the bucket tip and the angle ψ of the bucket.

α + β + γ = 180° - ψ In the present invention, we focused on this point, and added the rotation angles α, β, γ of the boom, arm, and bucket to the reference value 180° corresponding to the required bucket edge angle ψ. -ψ is compared and determined, and the boom cylinder, arm cylinder, or bucket cylinder is controlled based on this.

A potentiometer 9. is installed at the pivot point 1a of the boom 1, the pivot point 2a of the arm 2, and the pivot point 3a of the bucket 3, respectively.
10.11 is installed, and the rotation angles α, β, and γ of the boom, arm, and bucket are detected.

Based on these detection angles α, β, and γ, in the present invention, α+β+γ
boom cylinder 4, arm cylinder 5, or bucket cylinder 6 so that
As an embodiment of the present invention, as shown in FIG. 4, the rotation angle γ of the bucket is fixed, and the arm cylinder 5 is controlled 611 according to the boom rotation angle α.
An example of control is shown in which the sum α+β+γ of the boom rotation angle α, arm rotation angle β, and bucket rotation angle γ always matches the reference value 180°−ψ.

Signals indicating the boom rotation angle α, arm rotation angle β, and bucket rotation angle γ from the potentiometers 9, 10.11 (FIG. 3) are applied to an adder 20 to calculate α+β+γ.

On the other hand, the reference value corresponding to the bucket edge angle ψ = 180°−
ψ is set, and the comparator 21 compares the output α+β+γ of the adder 20 with the reference value E. In this comparison, if E>α+β+γ, a signal is applied to the solenoid valve 23 via the amplifier 22, and the oil pressure is switched so that the arm cylinder 5 is contracted.

If E is α+β+γ, a signal is applied to the [1 valve 25] via the amplifier 24, and the oil pressure is switched so that the arm cylinder 5 is extended.

If the arm cylinder 5 is controlled so that α+β+7''=E is established in accordance with the increase in the rotation angle α of the boom 1 by lowering it to the boom 1, the cutting edge angle of the Baquerato 3 with respect to the ground will be set to the desired value ψ can be made to match.

When E=α+β+γ, a coincidence output is generated from the comparator 21, and this signal is applied to the AND circuit 26, and the bucket 3
An AND condition is taken with a detection signal obtained by a detector 27 (for example, a pressure switch) that detects that the blade edge has contacted the ground. The output of the AND circuit 26 is sent as an excavation start signal, and this signal is used as a shift signal to the next excavation stroke (for example, extending the arm cylinder).

In this case, a lamp or the like may be turned on by the output of the AND circuit 26 to indicate that the bucket has been accurately inserted into the ground at the desired cutting edge angle.

〔Effect of the invention〕

As described above, the present invention has the advantage that the angle of the insertion edge of the bucket with respect to the ground can be accurately controlled to a desired value, is resistant to vibration shock, etc., and is inexpensive.

[Brief explanation of drawings]

Fig. 1 is an external view of a hydraulic power shovel, Fig. 2 is an explanatory drawing of the angle of the cutting edge of the bucket with respect to the ground, Fig. 3 is a detailed explanatory drawing of the present invention, and Fig. 4 is a control showing an embodiment of the present invention. It is a block diagram. 1...Boom, 2...Arm. 3... Bucket,
5... Arm cylinder, 9, 10.11... Potentiometer, 20... Adder, 21... Comparator,
22.24...Amplifier, 23.25...Solenoid valve. 1 kunyo j1

Claims (1)

[Claims] A potentiometer is provided at each rotation fulcrum of the boom, arm, and bucket, and the sum of the rotation angle of the boom, the rotation angle of the arm, and the rotation angle of the bucket is calculated from the output of the potentiometer. a comparator circuit that compares the output of the arithmetic circuit with a reference signal corresponding to the bucket edge angle; a detection means that detects that the bucket edge has contacted the ground; a coincidence output of the comparison circuit; An excavation control device for a hydraulic power shovel, comprising means for generating an excavation start signal instructing to start excavation on the condition that both of the detection means occur.