JP3098697B2 - Construction machine interference prevention equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for preventing interference between construction machines and, more particularly, to an apparatus for preventing interference between a bucket and a cab in a micro-swing hydraulic excavator.

[0002]

2. Description of the Related Art An ultra-small swing hydraulic excavator or the like has a main boom mounted on an upper swing body so as to be capable of raising and lowering, and an arm and a bucket are extended from the main boom via a laterally bent boom. The side-bending boom is formed so as to be rotatable left and right with respect to the main boom, and even when the side-bending boom is rotated left and right, the arm and the bucket are always parallel to the main boom. It is formed to keep. Therefore, if the arm is pulled in a state where the side-folding boom is rotated toward the cab, the bucket and the cab may interfere with each other.

[0003] Conventionally, this type of construction machine is provided with a device for preventing such interference. The interference prevention device is provided with an angle sensor at a pivot point of each working machine such as a main boom, a side-bending boom, and an arm, and a deceleration stop proportional valve for adjusting hydraulic oil of each working machine is provided. A coordinate value of a pivot point between the arm and the bucket with respect to the upper swing body (hereinafter, referred to as a "bucket position") is calculated based on the detection value of the angle sensor, and the deceleration stop proportional valve is calculated according to the bucket position. Is configured to operate.

[0004] The interference prevention device has three regions, a safety region S far away from the body, a deceleration region D inside the safety region S, and a stop region L inside the body and close to the body as determination regions for the interference prevention control. Is set. Then, as shown in FIG.
Command signal f for operating the proportional valve for deceleration and stop
(X) is zero in the safety zone S, and when it enters the deceleration zone D, the x-coordinate value of the bucket position (where the x-coordinate is the origin at the pivot point between the upper swing body and the main boom, As the front-rear direction of the upper revolving superstructure (the forward direction is set as a plus direction) decreases, it increases at a constant gradient α, and further increases in a step-like manner when it enters the stop region L, so that the maximum value fmax It is set to be.

The x-coordinate value of the bucket position is x
_{If 1} , the command signal f (x ₁ ) is output. As a result, the throttle amount of the deceleration stop proportional valve changes, and the amount of hydraulic oil supplied to each working machine increases or decreases. Therefore, FIG.
The vertical axis of can be regarded as the deceleration applied to each working machine. That is, in the deceleration range D, as the bucket position approaches the upper revolving structure and the x-coordinate value decreases, the throttle amount of the deceleration / stop proportional valve increases, and the degree of deceleration of each work machine increases. I do. Then, when the vehicle enters the stop zone L, the proportional valve for deceleration and stop is completely closed, the degree of deceleration is maximized, and each work machine is stopped.

[0006]

The performance of the proportional valve for decelerating and stopping has individual differences due to manufacturing variations. Therefore, even if the same command signal is given in the deceleration range, a desired deceleration cannot be obtained depending on the individual. Further, even with the same deceleration stop proportional valve, the responsiveness differs depending on the hydraulic oil temperature, and the responsiveness is poor when the temperature is low and the hydraulic oil is cooled.

Further, even if the individual performance is good and the hydraulic oil is also at an appropriate temperature, if the approaching speed of the working machine is high, the work machine will enter the stop zone before being sufficiently decelerated. In this case, if the gradient α in FIG. 4 is set steeply,
Such a phenomenon can be avoided, but in this case, when approaching at a medium speed, the speed is reduced more than necessary, and the section moving at low speed becomes longer. In addition, when the speed of the working machine is high, there is a means for performing a stopping process at a farther place in accordance with the speed (Japanese Patent Publication No. 7-94731, etc.), but this means increases a shock at the time of stopping.

Therefore, there is a technical problem to be solved so that an appropriate deceleration operation can be performed irrespective of individual differences in performance of the deceleration stop proportional valve, temperature, and approach speed of the work machine. Therefore, an object of the present invention is to solve the problem.

[0009]

SUMMARY OF THE INVENTION The present invention has been proposed in order to solve the above-mentioned problems, and has a means for detecting a position of a working machine which can be offset right and left with respect to an upper revolving structure. means for calculating the bucket position based on the detection value of the detection means is provided, and the bucket position deceleration
In order to change the deceleration rate according to the speed of the bucket in the range , a proportional valve for deceleration and stop is provided for adjusting the hydraulic oil of the working machine, and a command signal for operating the proportional valve for deceleration and stop is set. When the bucket position is in the deceleration range, the calculated value of the bucket position is time-differentiated, and the bucket position is changed in accordance with the differential value in the front-rear direction of the upper revolving unit. The apparatus for preventing interference of a construction machine according to claim 1, further comprising: obtaining a virtual bucket position shifted to, and outputting a set value of a command signal corresponding to the virtual bucket position to the proportional valve for deceleration and stop. is there.

[0010]

FIG. 1 is a block diagram showing an embodiment of the present invention.
This will be described in detail with reference to FIG. FIG. 1 is a left side view of an ultra-small turning hydraulic excavator 1 equipped with an interference prevention device. An upper turning body 5 is horizontally omnidirectional on a lower running body 3 including left and right crawlers 2 and 2 via a ball race 4. It is mounted so that it can turn freely. A main boom 7 is pivotally mounted to the right (in the depth direction in the figure) of the cab 6 of the upper revolving unit 5, and the main boom 7 is formed so as to be raised by the expansion and contraction operation of a boom cylinder 8. A horizontal boom 9 is pivotally attached to the tip of the main boom 7, and the base end and the other end of the offset cylinder 10 are connected to the left side of the distal end of the main boom 7 and the horizontal boom 9, respectively. The horizontal folding boom 9 is pivotally attached to the left side surface, and is formed so as to rotate in the left-right direction by the expansion and contraction operation of the offset cylinder 10.

An offset arm 11 is pivotally attached to the end of the side-bending boom 9 so as to be rotatable in the left-right direction.
A base bracket 12 protrudes from the left end of the main boom 7 (toward the front in the figure).
A top bracket 13 protrudes from the left side surface (forward direction in the figure) of the offset arm 11, and one end and the other end of the rod 14 are pivotally connected to the base bracket 12 and the top bracket 13, respectively. . Therefore, when the lateral bending boom 9 is rotated left and right by extending and contracting the offset cylinder 10, the offset arm 11 always keeps a parallel relationship with the main boom 7 by the action of the rod 14.

An arm 15 is connected to the front of the offset arm 11, and a bucket 16 is connected to a tip of the arm 15. Thus, when the offset cylinder 10 is expanded and contracted, the arm 15 and the bucket 16 are offsetly moved left and right with respect to the upper swing body 5.

The rear end of the offset arm 11 and the rear end of the arm 15 have arm cylinders 1 respectively.
7 is pivotally connected to the base end and the other end of the arm cylinder 1.
The arm 15 is formed to be rotatable vertically with respect to the offset arm 11 by the expansion and contraction of the arm 7. Also, the rear of the upper surface of the arm 15 and the bucket 1
The base end and the other end of the bucket cylinder 18 are pivotally connected to the rear portion of the bucket 6, respectively. I have.

A boom angle sensor 19 is provided at a pivot point between the upper revolving unit 5 and the main boom 7, and a pivot between the main boom 7 and the side-bending boom 9 is provided. An offset angle sensor 20 is provided at the landing point. Further, an arm angle sensor 21 is provided at a pivot point between the offset arm 11 and the arm 15. Outputs of these angle sensors 19, 20, and 21 are sent to a controller 22 mounted in the cab 6, respectively, and are subjected to data processing by a program stored in the controller 22 to obtain a spatial coordinate value of the bucket position P ( Position data) is calculated.

The space coordinates are space coordinates based on the upper swing body 5, and the upper swing body 5 and the main boom 7
An x-axis for determining the position of the upper swing body 5 in the front-rear direction, a y-axis for determining the position in the left-right direction, and
It is a three-dimensional orthogonal coordinate system including a z-axis for determining a position in the vertical direction. The space coordinates are divided into three areas of a safety area S, a deceleration area D and a stop area L by two boundary planes A and B shown by two dashed lines in the figure. The safety zone S is expanded and a stop zone L is set in the immediate vicinity of the fuselage. A deceleration zone D is interposed between the safety zone S and the stop zone L.

When the bucket position P is in the safety zone S, the command signal output from the controller 22 to the deceleration / stop proportional valve 23 is zero. On the other hand, when the bucket position P is in the deceleration area D and the stop area L,
A command signal having a predetermined magnitude is output from the controller 22 to the deceleration / stop proportional valve 23.

The solid line in the graph shown in FIG. 2 indicates the set value f of the command signal stored in the controller 22.
(X). As can be seen, the set value f (x)
Is exactly the same as that of the conventional interference prevention device shown in FIG. However, when the bucket position P enters the deceleration region D from the safety region S, the controller 22 time-differentiates the position data x on the x-axis coordinate of the bucket position P,
An approach speed x '= dx / dt is obtained, and a value Kx' obtained by multiplying the approach speed x 'by a predetermined proportionality coefficient K is subtracted from the position data x to obtain virtual position data x _M = x of the bucket position P.
-Kx 'is calculated. Then, this virtual position data x _M
The corresponding command signal f (x _M) outputs the deceleration stop proportional valve 23 to the.

For example, at time t₀Bucket position P at
The position data of x₀(= X (t₀))
Location data x₀And one step before (time t_-1) To sump
Ringed position data x_-1(= X (t_-1)) And by
And time t₀Approach speed x of bucket position P at₀′
= (X₀-X_-1) / (T₀-T_-1) = (X₀-X₁) /
Δt can be determined. And this approach speed
x₀′ Using the virtual position data x_M0= X₀-Kx₀'But
And thereby the command signal f (x_M0) = F (x ₀−
Kx₀') Is output.

Therefore, as shown by a two-dot chain line in FIG. 3A, the greater the approach speed x 'when entering the deceleration zone D from the safety zone S, the greater the actual position data x of the bucket position P. The virtual position data x _M is larger than cab 6
Shift closer. As a result, the command signal f (x _M ) output at the initial stage of the deceleration operation becomes larger than the initial set value f (x), and the deceleration / stop proportional valve 23 is narrowed down more quickly. As a result, the amount of hydraulic oil supplied to the boom cylinder 8, the offset cylinder 10, and the arm cylinder 17 decreases rapidly, and the approach speed x 'decreases.

[0020] 'When becomes smaller, the shift width Kx virtual position data x _M Along with this' approach speed x so gradually shrank, the output signal f (x _M) the set value f (x) It reaches the stop area L asymptotically.

On the other hand, if the individual performance of the deceleration stop proportional valve 23 is not good, or if the operating oil temperature is low in the cold season, the deceleration operation is started by entering the deceleration range D. However, the approach speed x 'does not immediately decrease. Thus, while the shift width K of the virtual position data x _M
x 'cannot be reduced so much, and as shown in FIG.
The output signal f (x _M ) is already in the middle of the deceleration range D in the middle of the deceleration range D.
Near the maximum value within Thereby, an extremely large deceleration operation is performed, and the approach speed x 'can be reduced. Then, the output signal f (x _M) becomes the speed that is sufficiently decelerated immediately before the stop zone L gradually approaches the set value f (x).

Thus, the shock at the time of stopping can be reduced as much as possible, and the amount of overshoot can be minimized. Also, when entering the deceleration zone D at medium low speed, the shift width Kx 'is small, the output signal f (x _M) becomes substantially in accordance with the set value f (x), excessive deceleration operation Nothing is done.

The present invention can be variously modified without departing from the spirit of the present invention, and it is natural that the present invention extends to the modified ones.

[0024]

As described above, the present invention provides a bucket
When the position is in the deceleration range, the calculated value of this bucket position
Is differentiated with respect to time, and the bucket position is raised according to the differentiated value.
Virtual bucket position shifted in the longitudinal direction of the revolving superstructure
And obtain the command signal corresponding to this virtual bucket position.
It is configured to output the set value to the proportional valve for deceleration and stop.
Therefore, regardless of the set value of the command signal corresponding to the bucket position, if the approach speed is high, it is possible to output a command signal that is larger than the initial set value. Can be asymptotically set.

Therefore, when the approach speed does not decrease very much because the individual performance of the proportional valve for deceleration and stop is not good or the responsiveness is deteriorated due to the cooling of the hydraulic oil, a large output signal is applied. Will continue to be
An appropriate deceleration operation appropriate for the proportional valve for deceleration and stop can be performed. Further, unnecessary deceleration is not performed.

Thus, the shock at the time of stopping can be reduced as much as possible, and the amount of overshoot can be suppressed to the minimum.

[Brief description of the drawings]

FIG. 1 is a left side view of a micro turning hydraulic excavator.

FIG. 2 is a graph illustrating the magnitude of a set value of a command signal stored in the interference prevention device according to the present invention, wherein the horizontal axis represents the x-coordinate value of the bucket position, and the vertical axis represents the command signal.

FIG. 3 is a graph illustrating a command signal actually output with respect to a bucket position in FIG. 2 by a two-dot chain line;
(A) targets a proportional valve for deceleration stop with good responsiveness, and enters the deceleration range from the safety range at a relatively high speed.
(B) shows a case where a proportional valve for deceleration and stop having poor response is set as an operation target.

FIG. 4 is a graph illustrating the magnitude of a set value of a command signal (that is, an actual output signal) stored in a conventional interference prevention device, wherein the horizontal axis is the x-coordinate value of the bucket position, and the vertical axis is This is a command signal.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Ultra-small turning type hydraulic excavator 5 Upper turning body 6 Cab 7 Main boom 8 Boom cylinder 9 Side bending boom 10 Offset cylinder 11 Offset arm 15 Arm 16 Bucket 17 Arm cylinder 19 Boom angle sensor 20 Offset angle sensor 21 Arm angle sensor 22 Controller 23 deceleration stop proportional valve S safety margin D velocity reduction zone L stop zone P bucket position f (x) command signal for setting values f (x _M) command signal actually output

Claims (1)

(57) [Claims] 1. A means for detecting a position of a work implement capable of being offset to the left and right with respect to an upper revolving structure, a means for calculating a bucket position based on a detection value of the detecting means, and as deceleration rate is varied depending on the speed of the bucket deceleration zone, a deceleration stop proportional valve for adjusting the hydraulic oil of the working machine is provided, further, a command signal for operating the deceleration stop proportional valve When the bucket position is in the deceleration range, the calculated value of the bucket position is time-differentiated, and the bucket position of the upper revolving unit is changed according to the differentiated value. An interference prevention device for a construction machine, wherein a virtual bucket position shifted in the front-rear direction is obtained, and a set value of a command signal corresponding to the virtual bucket position is output to the deceleration stop proportional valve.