JP2798748B2 - Automatic setting device for attitude of work attachment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION A. Industrial Field of the Invention The present invention relates to a device for automatically setting a posture angle of a work attachment capable of controlling a posture angle by an actuator.

B. Prior Art FIG. 3A shows an example of an articulated foundation working machine (hereinafter referred to as a working machine) previously proposed by the present applicant. This work machine CM
Consists of an upper revolving unit US rotatably provided on a lower traveling unit LT, and a first arm 1, a second arm 2, a third arm
An arm 3 and a first cylinder 5, a second cylinder 6, and a third cylinder 7 for driving the arms 3 are provided. Further, the rotary excavation bucket 4 is mounted on the tip of the third arm 3, and the attitude angle of the bucket is controlled by the fourth cylinder 8.

When digging with such a working machine, the digging direction is the third
In most cases, the direction is vertical or horizontal to the ground as shown in FIGS. (A), (b), and (c).
Prior to the start of the excavation, the driver has adjusted the excavation direction, that is, the posture angle of the rotary excavation bucket 4 visually or by a signal of a signer.

C. Problems to be Solved by the Invention For this reason, when the rotary excavation bucket is in the hole and cannot be seen, not only is a signaler always required, the work efficiency is poor, but also labor saving cannot be achieved. Moreover, it is difficult to adjust the posture angle of the rotary digging bucket correctly by the visual method. There were problems such as collapse.

A technical object of the present invention is to automatically return a posture of a work attachment such as a rotary excavation bucket to an angle origin closest to the posture among a plurality of predetermined angle origins.

D. Means for Solving the Problems The present invention provides an angle detecting means for detecting an angle of each arm and the attachment and outputting an angle signal, and an attitude angle calculating means for calculating an attitude angle of the attachment based on the angle signal. Selecting means for selecting an angle origin closest to the attitude angle among a plurality of preset angle origins, and drive control means for controlling an actuator to return the attitude angle of the attachment to the selected angle origin. By doing so, the above technical problem is achieved.

E. Operation The means for selecting the angle origin selects the angle origin closest to the posture angle of the work attachment among a plurality of predetermined angle origins based on the calculated posture angle of the work attachment. The drive control means drives the actuator so that the attitude angle of the work attachment is set to the selected angle origin.

F. Embodiment FIG. 1 shows a configuration of a control device of an embodiment in which the present invention is applied to a working machine having a rotary excavation bucket shown in FIG.

As shown in the coordinate definition of FIG.
, The angle of the first arm 1 to the ground is α, the relative angle of the second arm 2 to the first arm 1 is T ₂ , the relative angle of the third arm 3 to the second arm 2 is T ₃ , and the bucket 4
Third when a relative angle with respect to the arm 3 and the T ₄ of opposing attitude angle of the bucket 4 [delta] becomes _{δ = α-T 2 -T 3} -T 4 ... (1).

In FIG. 1, an angle detector 101 is mounted near a pivot point of the first arm 1 and detects a ground angle α of the first arm 1 by a well-known pendulum mechanism and a potentiometer. 2 arm, 3rd arm
3, attached to the pivot of the bucket 4, and using a well-known lever mechanism and potentiometer, the relative angle T ₂ between the first arm 1 and the second arm 2 and the relative angle T between the second arm 2 and the third arm 3 _3, detects the relative angle T ₄ of the third arm 3 and the bucket 4. The addition points 201 to 203 are provided by these angle detectors 101 to 104.
Is calculated on the basis of the angle signal from the above.

Reference numerals 301 to 303 denote angle origin setting devices of predetermined work attachments. In the embodiment, −180 ° and −9 shown in FIGS. 3A, 3B, and 3C corresponding to the rotary excavation bucket.
Three types, 0 ° and 0 °, are set. A determination unit 305 determines the posture angle δ of the work attachment, and switches the switching unit 304 to select the angle origin closest to the δ. Specifically, when δ> −45 °, the angle origin is δ
_The switching signal is sent to the switch 304 so that ₀ = 0 °, δ ₀ = 90 ° when −45 ° ≧ δ ≧ −135 °, and δ ₀ = −180 ° when δ <135 °. Output.

Reference numeral 350 denotes a selection switch.
In type the angle origin [delta] _0, which is selected to the adder 401, homing function is selected. That is, since the attitude angle δ obtained by the equation (1) is also input to the adder 401, δ−δ ₀ is calculated here, and the deviation is calculated by the coefficient unit 402.
Is multiplied by a coefficient to calculate a bucket angular velocity control value ₄ by the following equation (2). Therefore, the adder 401 and the coefficient unit 402 constitute an angular velocity control value calculation unit. ₄ = (δ−δ ₀ ) (2) Further, the function generator 501, the multiplier 502, and the coefficient unit 503 The flow control value Q ₄ is calculated by the following equation (3) and input to the electro-hydraulic conversion valve 10. Therefore, the function generator 501, the multiplier 502, and the coefficient unit 503 constitute a drive control value calculation unit.

Q ₄ = ₄ · f (T ₄ ) a ₄ (3) where f (T ₄ ) is a link correction coefficient a ₄ is a cylinder pressure receiving area. Pressure oil is supplied to the electro-hydraulic conversion valve 10 from a hydraulic source (not shown). and he, and supply pressure oil to the bucket cylinder 8 at a flow rate and direction corresponding to the flow rate control value Q ₄ input, the angle control is performed. The switching of the electro-hydraulic conversion valve 10 is also controlled by a signal from the manual operation lever 11, and the attitude angle of the rotary excavation bucket can be manually adjusted.

 Next, the operation of the present apparatus will be described.

Based on the angles detected by the angle detectors 101 to 104, the bucket-to-ground attitude angle δ is calculated at the addition points 201 to 203. Based on the bucket-to-ground attitude angle δ, an angle origin δ ₀ closest to δ is determined by the determiner 305 from among three predetermined angle origins, and the angle origin δ
₀ is selected. The angle origin [delta] ₀ and the selected switches the selection switch 350 to the contact a side is input to the summing junction 401,
The deviation from the bucket-to-ground attitude angle δ is calculated. This deviation is multiplied by a coefficient K by a coefficient unit 402 and converted into a speed control value ₄ for each bucket. Angular velocity control value ₄ based on the angle T ₄ are linked corrected and converted into the flow rate control value Q ₄ of the bucket cylinder 8.

The flow rate control value Q ₄ are supplied to the electro-hydraulic conversion valve 10, pressure oil from the hydraulic source is supplied to the bucket cylinder 8 at a predetermined direction, predetermined flow rate. As a result, the rotary excavating bucket 4 rotates, and the bucket angle is controlled in the direction of the angle origin. As each bucket approaches the angle origin, the angular velocity control value ₄
Decreases, and stops when almost coincident with the origin.

If the selection switch 350 is set to the contact b side, the angle deviation δ−δ ₀ becomes 0, and the origin return control is not performed. Further, by operating the manual operation lever 11 in the state of the contact b side, the attitude angle of the rotary excavation bucket 4 can be freely changed.

According to the present embodiment, the bucket angle is manually changed to an angle close to the bucket posture angle to be returned in advance, and the selection switch 350 is simply switched to the a contact side until the bucket posture angle matches the predetermined angle origin. Controlled automatically.
Further, if the selection switch 350 is switched to "a", it is possible to perform attitude angle control for keeping the attitude angle of the bucket constant even when the angle of each arm changes during excavation work.

In the configuration of the above embodiment, the angle detectors 101 to 104 serve as angle detectors,
0 is the selection means, adder 401, coefficient unit 402, function generator 501,
The multiplier 502 and the coefficient unit 503 constitute drive control means, respectively.

In applying the present invention, each component of the above embodiment may be configured as follows.

The number of arms is not limited to three.

Although the bucket was driven by a hydraulic cylinder, the invention is not limited to hydraulic pressure, and other actuators such as a hydraulic motor and a hydraulic rotary actuator can be used.

The work attachment is not limited to a rotary drilling bucket.

The angle of the first arm 1 may be detected as a relative angle with respect to the upper swing body, and the inclination of the work implement body may be detected to correct the relative angle.

The angle detector is not limited to a potentiometer, such as one using a magnetoresistive element, one using a differential coil, one using an optical or magnetic rotary encoder.

The angle origin is not limited to vertical or horizontal, and the set number can be arbitrarily determined.

It may be combined with the trajectory control of the attachment.

G. Effects of the Invention According to the present invention, simply adjusting the attitude angle of the work attachment to a desired angle origin by manual operation and giving a selection command, one of a plurality of preset angle origins is selected. Since one of them is selected and the work attachment is automatically controlled to the posture angle, the operability is improved, and the setting error of the posture angle is reduced, and the construction efficiency is greatly improved. Further, since no signal person is required, labor saving can be achieved, and the setting of the posture angle can be accurately performed even under the condition where the angle of the attachment cannot be visually recognized.

[Brief description of the drawings]

1 is an overall configuration diagram of an embodiment of the present invention, FIG. 2 is a diagram defining coordinates, and FIG. 3 is a side view of a working machine having a rotary excavation bucket, wherein (a), (b), (c) ) Indicates the difference in excavation posture. 1-3: arm, 4: rotary drilling bucket 5-8: hydraulic cylinder, 10: electro-hydraulic conversion valve 11: manual operation lever, 101-104: angle detector 301-303: angle origin setting device 304: switch, 305: Judgment device 350: Selection switch 401, 402: Angular velocity control value calculator 501 to 503: Drive control value calculator

Claims (1)

(57) [Claims] At least two arms rotatably connected via a joint, a work attachment mounted on the tip of the arm, an actuator for driving the arm and the work attachment, and controlling the drive of the actuator And an angle detecting means for detecting an angle of each arm and the attachment and outputting an angle signal, and calculating an attitude angle of the attachment based on the angle signal. Attitude angle calculating means, selecting means for selecting an angle origin closest to the attitude angle from among a plurality of preset angle origins, and the actuator so as to return the attitude angle of the attachment to the selected angle origin. And a drive control means for controlling the attitude of the work attachment. Automatic setting device.