JPS6229566B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a laser beam receiver for controlling a bucket level of a hydraulic excavator.

Generally, in a power shovel equipped with a boom 1, an arm 2, and a bucket 3 as shown in FIG. 1, when only the boom 1 is rotated, the trajectory of the bucket tip 3a draws an arc as shown by arrow A.
When only arm 2 is rotated, the bucket tip 3a
The trajectory draws an arc as shown by arrow B.

By the way, when performing linear ground leveling work such as slope leveling or surface leveling using the above-mentioned power shovel, the above-mentioned boom 1 and arm 2 must be operated at the same time. Therefore, ground leveling work using a power shovel is highly dependent on the skill of the operator, resulting in variations in work accuracy and a decrease in work efficiency.

Therefore, automatic control of a power shovel has been proposed in which a reference laser beam is emitted and the beam is captured by a light receiver attached to the arm of the power shovel to control the boom 1 and the arm 2. However, this device had a drawback in that the light receiver also rotated as the arm or boom rotated, making it impossible for the light receiver to accurately capture the laser beam.

The present invention has been made in view of the above-mentioned drawbacks, and is designed to keep the angle between the receiver and the laser plane constant at all times.
An object of the present invention is to provide a light receiving device that accurately captures a laser beam by making the laser beam enter from the front of a light receiving surface of a light receiver.

The present invention will now be described in detail with reference to the accompanying drawings.

In Figure 2, the coordinate origin is the boom pivot point O, and the laser plane b extended by the boom 1, arm 2, bucket 3, receiver 4, finished surface a, and laser beam projector (not shown) is x. - It is expressed in the y coordinate system. Here, the y-axis and the boom pivot point O
Let α be the angle (boom angle) formed by the straight line connecting the arm pivot point P and the straight line connecting the boom pivot point O and the arm pivot point P, and the straight line connecting the arm pivot point P and the bucket pivot point Q. Angle with (arm angle)
Let β be the angle between the straight line connecting the arm pivot point P and the bucket pivot point Q and the light-receiving surface of the receiver 4 (receiver angle), and the angle between the finished surface a and the x-axis (the finished surface The angle of inclination) is assumed to be θ. Further, the laser plane is parallel to the finished surface a and is set at a height such that the laser beam enters the center of the light receiving surface of the light receiver 4. As can be seen from the figure, the laser plane b and the light receiving surface 4 of the light receiving surface 4
In order for a to be orthogonal, the condition α+β++θ=π……(1) must be satisfied. When equation (1) above is solved for the receiver angle, it becomes =π-(α+β+θ) (2). That is, by controlling the light receiver angle so as to satisfy the above equation (2), the light receiving surface 4a
and the laser plane b come to intersect perpendicularly.

3 and 4 are block diagrams showing an example of a control circuit according to the present invention. FIG. 3 shows a control system for the boom cylinder 8 based on the output of the light receiver 4,
FIG. 4 shows a control system for the receiver angle.

Furthermore, FIG. 5 shows an embodiment of a receiver angle variable device for controlling the receiver angle.
FIG. 6 shows an example of how this receiver angle control device is installed at the tip of the arm.

Assume that the light receiver 4 captures the laser beam at the center of the light receiving surface as shown in FIG. Therefore, when the arm angle β is changed by manually operating the arm 2, the center of the light receiving surface of the light receiver 4 attached to the arm 2 is shifted from the laser plane b. The photodetector 4 applies a signal of polarity and magnitude corresponding to the direction and magnitude of the shift to the amplifier circuit 5 (FIG. 3).
The amplifier 5 amplifies this signal and applies it to the solenoid valve 7 via the drive circuit 6, so that the solenoid valve 7 switches the amount and direction of the pressure oil in the boom cylinder 8. The boom cylinder 8 rotates the boom 1 by applying pressure oil. Then, when the light receiver 4 captures the laser beam at the center of the light receiving surface, the above operation stops. In this way, the boom angle α is automatically controlled according to the arm angle β.

The circuit shown in FIG. 4 includes potentiometers 9, 10, 11, 12, adders 13, 14, a drive circuit 15, and It consists of a drive motor 16. The potentiometer 9 is arranged at the boom pivot point O and detects the boom angle α automatically controlled by the circuit shown in FIG.
A signal corresponding to is added to the adder 13. The potentiometer 10 is disposed at the arm pivot point P, detects the arm angle β of the arm 2 rotated manually, and adds a signal corresponding to -β to the addition point 13. Further, the potentiometer 11 is used to preset the finished surface inclination angle θ, and generates a signal corresponding to −θ, which is applied to the adder 13. Adder 1
3 adds the above three input signals and adds a signal corresponding to -(α+β+θ) to the adder 14. On the other hand, the potentiometer 12 is connected to the receiver directly connected gear 18 (fifth
), which detects the receiver angle and adds a signal corresponding to - to the other input of the adder 14. The adder 14 adds the signal corresponding to the angle π and the above two input signals, and applies the signal corresponding to the deviation angle _e to the drive motor 16 via the drive circuit 15. However, the deviation angle _e is _e = π - (α + β + θ) - (3). A drive motor 15 controls the receiver angle based on an input signal. That is, the driving force of the drive motor 15 is transferred to the drive motor directly connected gear 17 (fifth
The light is transmitted to the light receiver direct connection gear 18 via the light receiver (see Fig.).
The receiver direct connection gear 18 is the level adjustment cylinder 1
The light receiver 4 is coupled to the light receiver 4 via the light receiver 9, and the light receiver 4 is rotated in the direction of arrow C or D in accordance with the rotation of the light receiver direct connection gear 18. The level adjustment cylinder is used to first adjust the support length of the light receiver 4 so that the laser beam is captured at the center of the light receiving surface. In this way, the receiver angle has a deviation angle _e of 0.
controlled so that And the deviation angle _e is 0
Then, the above equation (3) becomes equal to the above equation (2), and the light receiving surface 4a of the light receiver 4 and the laser plane b intersect perpendicularly. Therefore, Fig. 7a,
When the arm 2 is moved as shown in b and c, the distance between the laser plane b and the bucket tip 3a is kept almost constant except for a slight error caused by the position of the variable receiver angle device, and accurate grading is achieved. I can work.

As described above, according to the present invention, the laser beam can be accurately captured regardless of the rotation of the boom and arm. In addition, since the receiver and laser beam are configured to intersect perpendicularly,
Enables highly accurate and stable land leveling work.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of the operation of the power shovel, FIG. 2 is a diagram showing the coordinate positions of the light receiver and the working arm of the power shovel according to the present invention, and FIG. 3 is an embodiment of the boom angle control circuit according to the present invention. A block diagram showing
FIG. 4 is a block diagram showing an embodiment of the receiver angle control circuit according to the present invention, FIG. 5 is a side view of the receiver angle variable device according to the present invention, and FIG. 6 is the receiver angle variable device according to the present invention. FIG. 7 is a diagram showing a light receiver that rotates as the arm moves. 1...Boom, 2...Arm, 3...Bucket, 4...Receiver, 5...Amplification circuit, 6, 15...
... Drive circuit, 7 ... Solenoid valve, 8 ... Boom cylinder, 9, 10, 11, 12 ... Potentiometer, 13, 14 ... Adder, 16 ... Drive motor, 17 ... Drive motor direct connection gear , 18...Receiver direct connection gear, 19...Level setting cylinder.

Claims (1)

[Claims] 1. In a light receiving device that is disposed on the arm of a working machine having a boom, an arm, and a bucket and receives a reference laser beam stretched parallel to a finishing surface, the arm pivot point and the bucket pivot point A receiver angle variable device that changes the angle formed by the straight line connecting the lines and the receiver light-receiving surface of the receiver (receiver angle), the boom angle is α, the arm angle is β, the finished surface inclination angle is θ, and the receiver angle is and a control device for controlling the light receiver angle variable device so that the expression α+β+θ+=π holds when . 2. The light receiver angle variable device has a level adjustment cylinder that changes the support length of the light receiver, a light receiver direct connection gear that is coupled to the light receiver via the level adjustment cylinder, and a gear that meshes with the light receiver direct connection gear, respectively. 2. The light receiving device according to claim 1, further comprising a drive motor directly connected gear and a light receiver angle detection potentiometer. 3 The control device that controls the receiver angle variable device outputs a signal corresponding to −α from a boom angle detection potentiometer that detects boom angle α and an output from an arm angle detection potentiometer that detects arm angle β. a first adder that adds a signal corresponding to −β to be given and a finished surface inclination angle θ to a signal corresponding to −θ output from a finished surface inclination angle presetting potentiometer that presets the finished surface inclination angle θ; The output signal of adder 1, the signal corresponding to - output from the receiver angle detection potentiometer that detects the receiver angle, and the signal corresponding to angle π are added, and the deviation angle _e (=π
-(α+β+θ)-), and the light receiver angle variable device is controlled based on the output signal of the second adder. The light receiving device according to item 1.