JP3120646B2 - Excavator movement control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a movement control device for an excavator, and more particularly to an excavator in which a rear bogie is self-propelled in synchronization with the excavation speed of a shield (excavator body) in a shield excavator or the like. Related to movement control.

[0002]

2. Description of the Related Art In an excavator having an excavator main body and a rear bogie, the excavator main body and the rear bogie are connected by a hydraulic hose, an electric wire, or the like. Therefore, it is desirable that both are synchronously moved at a constant interval. . In the conventional excavator, for the synchronous movement, the two are connected by a mechanical connecting device such as a fixed-size wire or a rod, and the rear bogie is towed by the excavator body.

[0003] However, in a work place where the excavator draws a sharp curve in the vertical or horizontal direction, if the excavator body pulls the rear bogie with a mechanical connecting device, a component force is generated in a direction perpendicular to the moving direction, and the improper force is generated. There is a problem of becoming stable. In addition, there is a problem that the connecting device cannot touch the side wall and cannot be pulled on an extremely curved road.

[0004] In order to solve such a problem, an excavator having a self-propelled rear bogie has been proposed.
The rear bogie self-propelled device described in Japanese Patent Publication No. 00 performs speed control such that the excavating speed of the excavator body and the self-propelled speed of the rear bogie are equalized to maintain the distance between the two at a predetermined value, and The rear bogie self-propelled device described in Japanese Patent No. 4-92100 performs drive control to compare the excavation distance of the excavator body and the self-propelled distance of the rear bogie so that both distances are equal to each other to reduce the distance between the two. It is kept at a predetermined value.

[0005]

However, the control method for keeping the distance between the excavator body and the rear bogie at a predetermined value by controlling the speed of the excavator body and the rear bogie is based on a detection error of a speed detector, a control error of a drive speed control device, and the like. A slight speed difference occurs between the moving speeds of the two, and this speed difference results in a change in the distance. If these speeds are accumulated, the distance between the two greatly changes, so that there is a problem that manual adjustment is required. .

Further, a control method for controlling the driving speed of the rear bogie so that the excavation distance and the self-propelled distance are equal to each other to keep the distance between the two bogies at a predetermined value is based on a deviation from a target distance. Because of the control, it is difficult to obtain a stable control amount. This type of control increases the self-propelling speed of the rear bogie when a large deviation occurs, but if there is a large deviation at the start of self-propelling, the rear bogie starts at a high speed, And the surrounding workers are dangerous, and there is also a risk that excessive force may act on the hydraulic hoses, electric wires, and the like to damage them.

Accordingly, an object of the present invention is to provide an excavator in which a rear bogie is self-propelled and the distance between the rear bogie and the excavator body is controlled to a predetermined value. Is to be able to

[0008]

According to a first aspect of the present invention, there is provided an excavator movement control device for self-propelling a rear bogie in synchronization with the excavating speed of the excavator main body, wherein a distance between the excavator main body and the rear bogie is provided. A relative distance detector responsive to, a driving device for causing the rear bogie to run at a speed slightly higher than the excavation speed of the excavator main body, and a driving device responsive to the detection signal of the relative distance detector, When the relative distance between the rear bogies is equal to or more than a predetermined range, the driving device is controlled so that the rear bogies self-propelled, and when the relative distance is equal to or less than a predetermined range, the self-propelled vehicle is stopped. A drive control device for controlling the drive device is provided, and a second invention is a movement control device for an excavator that allows a rear bogie to self-run in synchronization with the excavation speed of an excavator body, A digging speed detector on the machine body, A driving device that causes the rear bogie to travel by itself at a slightly higher moving speed than the excavating speed detected by the excavating speed detector, and a relative distance detector that detects a relative distance between the excavator body and the rear bogie. Responsive to the detection signal of the relative distance detector, the driving device is controlled so that the rear bogie is self-propelled when the relative distance between the excavator main body and the rear bogie is equal to or greater than a predetermined range. And a drive control device for controlling the drive device so as to stop self-propelling when the distance becomes equal to or less than a predetermined range.

[0009]

When the relative distance between the excavator main body and the rear bogie exceeds a predetermined range, the driving device makes the rear bogie self-propelled at a speed slightly higher than the excavating speed of the excavator main body, and moves below the predetermined range. Stops, the self-propelled vehicle stops, and the distance between the excavator body and the rear bogie is kept within a predetermined range, so that detection errors and control errors are accumulated and the distance between the excavator main body and the rear bogie is reduced. There is no significant change.

In addition, since the self-propelled speed of the rear bogie is slightly higher than the excavation speed, unstable running does not occur.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a side view schematically showing an excavator according to the first invention. The excavator main body 1 includes a propulsion jack 2 serving as an excavation (propulsion) drive source.

The self-propelled rear bogie 3 includes a hydraulic pump 4 and
Hydraulic controller 5, direction switching valve 6, hydraulic motor 7, drive wheel 8, relative distance detector 9, synchronous drive control device 1
0 is provided. The hydraulic motor 7 is controlled by a hydraulic controller 5 from the hydraulic pump 4 and rotates with hydraulic pressure supplied via a direction switching valve 6 to rotate the drive wheels 8. The relative distance detector 9 generates an electric signal indicating a relative distance between the excavator main body 1 and the rear bogie 3, and the hoist traveling beam 11 erected between the excavator main body 1 and the rear bogie 3.
A wire reel type potentiometer, an absolute type encoder, or the like, whose electric resistance value (electric signal output) fluctuates in response to a change in the relative position between the vehicle and the rear bogie 3 is used.

In order to detect the relative distance between the excavator main body 1 and the rear bogie 3 based on a change in the relative position between the hoist traveling beam 11 and the rear bogie 3, the tip of the hoist traveling beam 11 is connected to the excavator main body. Pin 1 can swing freely
2 and swingably and slidably mounted in the back-and-forth carriage 3 on the lateral displacement and fall prevention pedestal 13. The relative distance is detected by the amount of sliding in the fore-and-aft direction. The vessel 9 is operatively connected.

The hoist crane 14 travels on the hoist traveling beam 11 and conveys the segments 15 and the like.

The synchronous drive control device 10 compares the relative distance obtained based on the electric signal output from the relative distance detector 9 with a set value so that the relative distance falls within a predetermined range. Thus, the direction switching valve 6 is controlled to interrupt the self-propelled movement of the rear bogie 1. That is, when the relative distance exceeds a predetermined range, the direction switching valve 6 is opened in the forward direction, and the hydraulic motor 7 is rotated so that the rear bogie 3 runs in the forward direction. The rear carriage 3 is stopped by closing the valve 6. Incidentally, the self-propelled speed of the rear bogie 3 is set to be slightly higher than the maximum excavating speed of the excavator body 1 and is controlled by the hydraulic controller 5.

FIG. 2 is a block diagram showing the internal configuration of the synchronous drive control device 10. As shown in FIG. The automatic control system is configured by a closed loop that performs feedback control for self-propelling and stopping the rear bogie 3 so that the relative distance is within a predetermined range.

The hydraulic controller 5 for controlling the rotation speed of the hydraulic motor 7 to determine the self-propelled speed of the rear bogie 3 includes a speed setting device 1
The control target value is set by the speed command signal V given from 01. This control target is set to a value slightly higher than the maximum excavation speed of the excavator body 1. Comparator 102
Detects the relative distance based on the electric signal output from the relative distance detector 9, compares the detected relative distance with a limit value given from the upper / lower limiter 103, and, if the relative distance is equal to or less than the lower limit value, automatically detects the relative distance. The self-propelling is stopped by energizing the coil 104a of the running stop control relay, and energizing the coil 105a of the self-propelling start control relay if the value exceeds the upper limit.

The normally open contact 106b operated by the coil 106a of the self-propelled automatic control relay is a forward control for controlling the direction switching valve 6 so as to open the direction switching valve 6 so that the rear bogie travels in the forward direction. It is connected in series with self-propelled relay coil 107a. The self-propelled automatic control relay coil 106a is manually operated with a normally closed contact 104b operated by the self-propelled stop control relay coil 104a to open and a normally open contact 105b operated and closed by the self-propelled automatic control relay coil 105a. Connected in series with the automatic control contact 108a of the automatic control setting switch 108 that opens and closes. The self-propelled automatic control relay coil 10 is connected to the normally open contact 105b.
The self-holding contact 106c operated by 6a is connected in parallel.

The reverse self-propelled relay coil 109a for controlling the direction switching valve 6 so as to open the direction switching valve 6 so that the rear bogie travels in the reverse direction is operated by the reverse control manual switch 1.
10 and connected in series with the forward self-propelled relay coil 10
7a is connected in series with a manual control contact 108b in parallel with a series circuit in which a forward control manual switch 111 is connected. The normally closed contacts 107b and 109b are contacts for interlocking a circuit on the other side.

Incidentally, if the relative distance detector 9 is constituted by a switch which is turned on at an upper limit and a lower limit of the relative distance variation range, the lower limit switch sets the self-running stop control relay coil 104a.
Control, the self-running control relay coil 1 with the upper limit switch
05a can be controlled, and the upper / lower limiter 103 and the comparator 102 become unnecessary.

During the excavation work, the excavator main body 1 is driven by the excavator main body 1 at the excavation speed V, as shown in FIG.
Excavation is performed at 0, and the rear bogie 3 follows and travels at its own speed V. That is, the automatic control setting switch 108
Automatic control contact 108a is closed, manual control contact 108b
Is open and in the automatic control state, the self-propelled automatic control relay coil 106a is energized and the normally open contacts 106b, 106
When c is closed and the rear bogie 3 is running as shown in (a), the self-propelled speed V of the rear bogie 3 is higher than the excavating speed V0 of the excavator body 1, so that the relative distance between them is It is gradually shortened and reaches the lower limit. When the comparator 102 detects this state from the output signal of the relative distance detector 9 and the set value of the upper / lower limiter 103, it activates the self-running stop control relay coil 104a to open the normally closed contact 104b, and The automatic control relay coil 106a is deenergized to open the normally open contact 106b and stop self-propelled operation (b).

When the rear bogie 3 stops running, the relative distance between the two is increased by the excavator body 1 excavating (c).
Eventually the upper limit is reached. When the comparator 102 detects this state from the output signal of the relative distance detector 9 and the set value of the upper / lower limiter 103, it activates the self-running start control relay coil 105a to close the normally closed contact 105b, and the self-running The normally open contact 106b is closed by energizing the automatic control relay coil 106a to start self-propelled (d). Then, the self-propelled state becomes the same as (a) again (e).

When the self-propelled speed V of the rear bogie 3 is set to a fixed value slightly higher than the maximum excavation speed of the excavator body 1, the actual excavation speed V0 is relatively high (close to the maximum excavation speed). When the vehicle is in the state, as shown in FIG. 4, the self-propelling and stopping of the rear bogie 3 are less repeated, but when the actual excavation speed V0 is relatively low, as shown in FIG. And the repetition of stop increases.

When the rear bogie 3 is separated from the excavator main body 1 by a predetermined relative distance or more, the excavator configured as described above starts self-propelled and repeats self-propelled approaching the excavator main body 1. Accumulation of errors and control errors does not significantly change the relative distance between the excavator body 1 and the rear bogie 3. In addition, since the self-propelled speed is a predetermined speed slightly higher than the excavation speed, the rear bogie can be stably and accurately self-propelled without becoming dangerously high.

FIG. 6 is a side view schematically showing an excavator according to the second invention. This excavator is modified so that the self-propelled speed in the above-described excavator control device approaches the excavating speed of the excavator body 1 so as to reduce the repetition of self-propelled and stopped. Hereinafter, the same reference numerals are given to the same functional components, and the detailed description is omitted.

The excavator body 1 is provided with an excavation speed detector 16 which outputs an electric signal indicating the excavation speed in response to the extension of the propulsion jack 2. The excavation speed detector 16 can be configured using a wire reel type potentiometer, an encoder, or the like. Then, the synchronous drive control device 10 of the rear bogie 3 is modified so as to control the self-propelled speed of the rear bogie 3 to a value close to the actual excavation speed of the excavator body 1.

As shown in the block diagram of FIG. 7, the synchronous drive control device 10 uses an adder 112 to add the electric signal V0 output from the excavation speed detector 16 and the set value V1 output from the speed setting device 101. The speed command signal V is generated by the addition. The self-propelled speed of the rear bogie 3 needs to be higher than the actual excavating speed of the excavator body 1, but if it is significantly high, the frequency of self-propelling and stopping is increased. Therefore, the setting value V1 given from the speed setting device 101 is set so that the self-propelled speed of the rear bogie 3 is slightly higher than the excavation speed of the excavator body 1 in consideration of the excavation speed detection error and the control error. Is preferred.

According to such an excavator, the rear bogie 3
Travels at a self-running speed V slightly higher than the actual excavation speed V0 of the excavator main body 1, so that the relative distance between the rear bogie 3 and the excavator main body 1 is set to a predetermined value as shown in FIG. The time required to approach below the range becomes longer, and the repetition of self-propelling and stopping is reduced, thereby further improving the stability of self-propelling.

The relative distance detector 9 in the two embodiments measures the relative distance between the excavator body 1 and the rear bogie 3 by using a laser device or an ultrasonic device without using the hoist traveling beam 11. Obviously, it is possible to do so.

[0030]

As described above, according to the present invention, when the relative distance between the excavator main body and the rear bogie exceeds a predetermined range, the rear bogie is automatically moved at a speed slightly higher than the excavating speed of the excavator main body. Run, stop self-propelled when it falls below the predetermined range, and keep the distance between the excavator body and the rear bogie within the predetermined range, so that detection errors and control errors are accumulated and the excavator body The distance between the rear bogies does not change significantly.

In addition, the self-propelled speed of the rear bogie is slightly higher than the excavating speed of the excavator body, so that a stable self-propelled state can be obtained.

[Brief description of the drawings]

FIG. 1 is a side view schematically showing an excavator according to a first invention.

FIG. 2 is a block diagram showing an internal configuration of a synchronous drive control device in the excavator shown in FIG.

FIG. 3 is a conceptual diagram showing a moving state of the excavator according to the first invention.

FIG. 4 is a self-propelled characteristic diagram of the rear bogie of the excavator according to the first invention in a state where the actual excavation speed is relatively high.

FIG. 5 is a self-propelled characteristic diagram of the rear bogie of the excavator according to the first invention when the actual excavation speed is relatively low.

FIG. 6 is a side view schematically showing an excavator according to a second invention.

7 is a block diagram showing an internal configuration of a synchronous drive control device in the excavator shown in FIG.

FIG. 8 is a self-propelled characteristic diagram of the rear bogie of the excavator according to the second invention in a state where the actual excavation speed is relatively low.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1: Excavator main body, 2: Propulsion jack, 3: Rear bogie, 4
... Hydraulic pump, 5 ... Hydraulic controller, 6 ... Direction switching valve, 7 ...
Hydraulic motor, 9: relative distance detector, 10: synchronous drive control device.

Claims (4)

(57) [Claims] 1. A movement control device for an excavator for self-propelling a rear bogie in synchronization with an excavating speed of an excavator main body, comprising: a relative distance detector responsive to a distance between the excavator main body and a rear bogie; A driving device that causes the bogie to run at a speed slightly higher than the excavating speed of the excavator main body, and a relative distance between the excavator main body and the rear bogie in a predetermined range in response to a detection signal of the relative distance detector. A drive control device that controls the drive device to make the rear bogie self-propelled when the above occurs, and controls the drive device to stop self-propelled when the relative distance becomes less than or equal to a predetermined range. A movement control device for an excavator, comprising: 2. The excavator movement control device according to claim 1, wherein the self-propelled speed of the rear bogie is set to a constant value slightly higher than the maximum excavation speed of the excavator body. 3. A movement control device of an excavator for self-propelling a rear bogie in synchronization with an excavating speed of an excavator main body, wherein the excavating speed detector of the excavator main body and the rear bogie are detected by the excavating speed detector. A driving device for self-running at a moving speed slightly higher than the detected excavation speed, a relative distance detector for detecting a relative distance between the excavator body and the rear bogie, and a response to a detection signal of the relative distance detector And, when the relative distance between the excavator main body and the rear bogie is equal to or more than a predetermined range, the driving device is controlled so that the rear bogie is self-propelled, and when the relative distance is equal to or less than a predetermined range. And a drive control device for controlling the drive device so as to stop self-propelling. 4. The movement control of an excavator according to claim 1, wherein the relative distance detector responds to a relative movement of a hoist traveling beam installed between the excavator body and the rear bogie. apparatus.