JPS6245372B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an automatic control device for construction machinery that automatically controls a working machine in a predetermined manner.

A hydraulic power shovel equipped with a boom, an arm, a bucket, and a device for rotating the boom has a large number of operating levers, and when performing excavation work, multiple operations are always required. For this reason, semi-automation or automation has been proposed in order to eliminate such simultaneous operations and facilitate operations. For example, in semi-automation where the arm, bucket, swing, etc. are automatically operated when the operator operates the boom lever, a limit switch or the like is attached to the link mechanism at the bottom of the boom operating lever as an automatic start signal, or An automatic start signal is generated by attaching a push button switch, foot switch, etc. to the seat.

However, the above-mentioned conventional signal detecting means has drawbacks such as the former being very troublesome to attach a switch, etc., and the latter having poor operability and therefore poor working efficiency.

The present invention was made for the purpose of eliminating the above-mentioned drawbacks, and is made by performing simple arithmetic processing on the rotation angle signal or rotation angle signal of the working arm of the boom, arm, etc. at the time of starting manual control of the work machine. The present invention provides an automatic control device for a power shovel that uses an automatic start signal for an automatic control operation of a working machine.

The present invention will be described in detail below based on one embodiment of the accompanying drawings.

In FIG. 1, the working machine of a hydraulic power shovel consists of a boom 1, operating arms such as an arm 2, and a bucket 3, and a hydraulic cylinder 4 that operates these arms.
~6. Further, the turning is performed by turning the rotating body 7 installed on the traveling body using a hydraulic motor 8. Each of these hydraulic cylinders 4 to 6 and the hydraulic motor 8 are controlled by a manual operation lever (not shown) located at the driver's seat.

Further, as shown in FIG. 2, angle detectors such as potentiometers 9, 10, 1 are installed at each rotation support point 1a, 2a, 3a of the boom 1, arm 2, bucket 3.
1 is provided. Each of these potentiometers 9, 10, 11 detects the boom angle α, arm angle β, and bucket angle γ, and outputs corresponding signals E〓, E〓,
Output E〓.

Now, when excavating earth and sand with a hydraulic power shovel, it is necessary to land the bucket at the excavation point while keeping the angle of the bucket edge constant so as to obtain maximum excavation, as shown in Figure 2. This operation of landing while controlling the bucket tip angle to a constant value is called bucket tip angle control.

In addition, after the earth and sand excavation is completed, the work equipment is rotated to the earth unloading position while raising the boom, but in this case, it is necessary to always keep the bucket opening horizontal to prevent the earth and sand from falling as it ascends boom 1. . This operation of controlling the bucket opening horizontally is called bucket opening horizontal control.

As is clear from FIG. 2, the following equation holds true during bucket edge angle control.

α+β+γ=180°− (1) In addition, the following equation holds true during horizontal control of the bucket opening.

α+β+γ=270°...(2) Figure 3 shows an example of an automatic control device for performing the above-mentioned bucket tip angle control and bucket opening horizontal control at the start of boom lever operation. FIG.

In FIG. 3, the adder 12 receives the current boom angle α and arm angle β from the potentiometers 9 and 10.
Boom angle signal E〓, arm angle signal E〓 corresponding to
has been added. In addition, in normal excavation work, the bucket angle γ is set to a constant angle γ ₀ by manual operation.
You can set it to . Therefore, in this case,
The potentiometer 11 for detecting the bucket rotation angle is not required. And this potentiometer 1
Instead of the output signal E〓 of 1, the preset bucket angle γ ₀
The signal E〓 ₀ corresponding to adder 1 is manually operated.
Add it to 2. The adder 12 receives input signals E〓, E
〓, E〓 ₀ are added, and a signal E corresponding to the angle α+β+γ expressed by the left side of equations (1) and (2) is output and added to the comparator 13.

The cutting edge angle setter 16 outputs a signal E ₁ corresponding to the angle 180° expressed by the right side of the equation (1) according to the preset cutting edge angle, and applies it to the switching circuit 18 .

Further, the aperture horizontal angle setter 17 outputs a signal E ₂ corresponding to the angle 270° expressed by the right side of the equation (2) and applies it to the switching circuit 18 .

The switching circuit 18 is switched by the signal E ₃ from the comparator 22 to output either the signal E ₁ or E ₂ , and when the signal E ₃ >0, the signal E ₁ is output.
When the signal E ₃ <0, the signal E ₂ is output and added to the comparator 13 .

The comparator 13 compares the input signal E with either E ₁ or E ₂ , and a signal E 〓 corresponding to the deviation is amplified by the amplifier 14 and then applied to the solenoid valve 15 . Solenoid valve 1
5 operates in response to the input signal E to control the hydraulic oil supplied to the hydraulic cylinder 5. hydraulic cylinder 5
is driven in accordance with this solenoid valve to control the rotation of the arm 2. The potentiometer 10 sequentially outputs a signal E according to the arm angle β and applies it to the adder 12 as described above.

The manual switching valve 20 is switched and controlled by the boom lever 19 and controls the hydraulic fluid supplied to the hydraulic cylinder 4 . The hydraulic cylinder 4 operates based on the manual switching valve 20 to control the rotation of the boom 1. The potentiometer 9 outputs a signal E〓 corresponding to the current boom angle α, and outputs a signal E〓 to an adder 12, a memory circuit 21, and a comparator 22.
Add to.

The memory circuit 21 stores the final value of the sequentially input signal E, that is, the signal corresponding to the rotation angle when the boom 1 is stopped, and outputs this stored value to be added to the comparator 22.

Comparator 22 receives input signal from storage circuit 21
Compare E′〓 with the current input signal E〓 from potentiometer 9, and when E′〓<E〓, the signal
When E ₃ >0, and E′〓>E〓, a signal E ₃ <0 is output and applied to the switching circuit 18 and the delay circuit 23.

The delay circuit 23 outputs a reset signal E≦ after a predetermined period of time, for example, one second, after the signal E ₃ is applied, and applies it to the memory circuit 21 . When this reset signal is applied to the memory circuit 21, the memory contents are reset and the memory circuit 21 starts the memory operation again. Note that the delay time is the time until the boom 1 rotates by a slight angle.

Now, assume that the boom 1 is stopped at a certain rotation angle _α0 as shown in FIG. In this state, the potentiometer 9 and the memory circuit 21 output a signal E〓 ₀ corresponding to this boom angle α ₀ . Therefore, no signal is output from the comparator 22.

Now, suppose that the boom lever 19 is manually operated, for example, to the boom lowering side. Then, assume that the boom 1 begins to rotate, and as shown in FIG. 4, the boom angle increases by a slight angle Δα from the boom angle α ₀ to reach the boom angle α ₀ +Δα. Potentiometer 9 is the boom angle α ₀ +
A signal E〓 ₀ +ΔE corresponding to Δα is output and added to the comparator 22 and adder 12. The comparator 22 outputs a signal E ₃ corresponding to the deviation ΔE between this input signal E〓 ₀ +ΔE and the input signal E〓 ₀ from the storage circuit 21 . The switching circuit 18 selectively outputs the setting signal E ₁ from the cutting edge angle setting device 16 based on this signal E ₃ and applies it to the comparator 13 . The comparator 13 generates a signal E according to the deviation between the signal E from the adder 12 and this signal _E1 .
δ is output and the solenoid valve 15 is controlled. The arm cylinder 5 operates in accordance with this electromagnetic valve 15, and drives the arm 2 so that the bucket edge angle becomes a preset angle expressed by the above equation (1). In this way,
The rotation angle β of the arm 2 is controlled in accordance with the downward movement of the boom 1, and the bucket tip angle is controlled to a predetermined value. Then, Bucket 3 landed at the excavation point,
When the operator returns the operating lever 19 to the neutral position, the operations of the boom 1 and arm 2 are stopped. Therefore, the bucket 3 lands with a predetermined edge angle.

On the other hand, the delay circuit 23 receives the signal E ₃ from the comparator 22.
After the predetermined delay time has passed, the reset signal E is outputted and applied to the memory circuit 21. When the memory circuit 21 receives this reset signal E, it resets the memory content _E , as described above.
Start memory operation again. And the boom 1
It memorizes the boom angle when the boom stops rotating and outputs the corresponding signal.

Therefore, the operator only has to start the desired excavation work after the bucket 3 lands on the excavation point as described above.

Also, contrary to the above, the boom 1 is at the boom angle α
Assume that when the boom lever 19 is stopped at ₀ , the boom lever 19 is manually operated to the boom raising side. Assume that the boom 1 begins to rotate and, as shown in FIG. 4, decreases from the boom angle α ₀ by a slight angle Δα to reach the boom angle α ₀ −Δα. Potentiometer 9 adjusts this boom angle α ₀
A signal E〓 ₀ -ΔE corresponding to -Δα is output and added to the comparator 22 and adder 12. In this state, excavated earth and sand are contained in the bucket 3, and the opening of the bucket is made horizontal by manual operation. The comparator 22 receives this input signal E〓 ₀ -△E and the input signal E〓 ₀ from the memory circuit 21.
A signal _-E3 corresponding to the deviation △E is output. The switching circuit 18 selectively outputs the setting signal E ₂ from the aperture horizontal angle setting unit 17 based on this signal -E ₃ and applies it to the comparator 13 . The comparator 13 outputs a signal E= corresponding to the deviation between the signal E from the adder 12 and this signal _E2 , and controls the solenoid valve 15. The arm cylinder 5 operates in response to this electromagnetic valve 15, and drives the arm 2 so that the opening of the bucket 3 becomes horizontal as expressed by the above equation (2). In this way,
The rotation angle β of the arm 2 is controlled according to the upward movement of the boom 1, and the opening of the bucket 3 is controlled horizontally.

detecting a semi-automatic start signal as described above;
The bucket 3 can be controlled to a predetermined angle expressed by the above equations (1) and (2).

In this embodiment, a case has been described in which a semi-automatic start signal is obtained based on a boom lever operation, that is, a boom rotation angle signal, but the invention is not limited to this. For example, an arm lever may be used instead of a boom lever. The earth and sand excavation start signal may be obtained based on the rotation angle signal of the arm. It is also possible to attach a position detector to the turning hydraulic motor and obtain a turning start signal based on the output of this detector.

Further, in this embodiment, a case has been described in which the bucket rotation angle γ is set to a predetermined value by manual operation as a preset angle, but the invention is not limited to this, and the bucket rotation angle γ from the potentiometer 11 is It is also possible to control the rotation of the bucket 3 according to the rotation of the boom 1 and the arm 2 by using the signal E corresponding to .

As described above, according to the present invention, there is no need to attach an external device to obtain a start signal as a semi-automatic start signal, and the structure can be simplified. Furthermore, since a semi-automatic start signal is obtained by electrically processing a signal from a rotation angle detector such as a boom, very little modification is required on the vehicle side. Also,
There are advantages such as no need for multiple operations, the operator can concentrate on his work, and work efficiency can be improved.

[Brief explanation of the drawing]

Figure 1 is an external view of a hydraulic power shovel, Figure 2
The figures are an explanatory diagram of the operation of the working machine of the power shovel shown in Fig. 1, Fig. 3 is a block diagram showing one embodiment of the automatic control device for the power shovel according to the present invention, and Fig. 4 is a block diagram showing an embodiment of the automatic control device for the power shovel according to the present invention.
The figure is a diagram showing the relationship between the boom angle and the output of the boom angle detection potentiometer shown in FIG. 3. 1...Boom, 2...Arm, 3...Bucket, 4~
6... Hydraulic cylinder, 7... Swivel body, 8... Hydraulic motor, 9-11... Potentiometer, 12... Adder, 13, 22... Comparator, 15... Solenoid valve, 16...
Blade edge angle setting device, 17...Aperture horizontal angle setting device, 18
...Switching circuit, 19...Boom lever, 21...Memory circuit, 23...Delay circuit.

Claims (1)

[Claims] 1. A boom rotatably attached to a point on the vehicle body and rotationally controlled by a first actuator, and a boom rotatably attached to the tip of the boom and rotationally controlled by a second actuator. In the automatic control device for a power shovel, the power shovel has an arm that is rotatably attached to the tip of the arm and a bucket that is rotationally controlled by a third actuator. a second detection means for detecting a rotation angle of the arm with respect to the boom; a third detection means for detecting a rotation angle of the bucket with respect to the arm; The sum of the rotation angle of the boom detected, the rotation angle of the arm detected by the second detection means, and the rotation angle of the bucket detected by the third detection means is a first a first control means for controlling the second actuator and the third actuator so that the angle is equal to a set value, so that the cutting edge angle of the bucket always remains constant regardless of the operation of the boom; and a rotation angle of the boom detected by the first detection means, a rotation angle of the arm detected by the second detection means, and a rotation of the bucket detected by the third detection means. By controlling the second actuator and the third actuator so that the sum with the moving angle is equal to a second set value, the opening of the bucket is always kept horizontal regardless of the operation of the boom. and boom rotation angle change detection means for detecting whether the rotation angle of the boom has changed to increase or decrease based on the output of the first detection means. and, if the boom rotation angle change detection means detects that the rotation angle of the boom has changed so as to increase, select the operation of the first control means, and determine that the rotation angle of the boom has changed so as to decrease. an automatic control device for a power shovel, comprising a selection means for selecting an operation of the second control means when the second control means is detected.