JPH03244787A - Method and device for excavating ditch by using liquid jet - Google Patents

Abstract

PURPOSE:To realize full automation by detecting lowering or the stop of an operation speed in a direction crossing an axis, extending in an excavating direction, at right angles, moving backward a nozzle through decision of abnormality of excavation, and re-starting normal excavation after re-excavation of an abnormal spot is effected. CONSTITUTION:A moving bed 4 is located in a manner to be longitudinally and laterally movable over a frame 2 and a rotary encoder 78 is mounted on the rear part of a motor 76 of a rotation drive device 66 for rotating a rotary coupling 64 to input a detecting signal to a control device 73. In the device 73, by comparing an inputted detecting signal with a preset allowable time distance, abnormality of a rotation speed is decided, and a nozzle 18 is moved backward with the aid of a motor 6. The nozzle 18 is moved to a coordinate available before the occurrence of abnormality, a set area range is excavated at a speed lower than a normal excavating speed, and normal excavation is restarted after completion of re-excavation. This method realizes full automation.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of industrial application The present invention comprises 1. The present invention relates to a groove excavation method and apparatus using a liquid jet. Note that in this specification, the term "liquid jet" includes a so-called abrasive water jet in which an abrasive material is mixed in a liquid.

(b) Prior Art Figure 6 shows a groove excavation device using a conventional liquid jet. A liquid jet nozzle (hereinafter simply referred to as a nozzle) 100 is a rotating tool 102.
It is attached to the tip of the tool 102 at a predetermined angle θ from the axis, and drills a hole having a diameter larger than the diameter of the tool 102 in the object 104 by ejecting a liquid jet while rotating the tool 102. , the groove 106 can be formed by moving the tool 102 along the excavation surface (in the left-right direction in the figure).

The groove 106 can be made to a predetermined depth by repeating the above operation.

(c) Problems to be Solved by the Invention However, according to the conventional groove excavation method and apparatus using liquid die-soto as described above, as shown in FIG. If there is a highly hard material such as reinforcing steel 204, that portion will not be completely excavated, resulting in an excavated remainder 206. Also,
If the abrasive material in the liquid jet becomes clogged and excavation is performed with insufficient supply of abrasive material, even if there are no hard foreign objects in the excavated part, the excavated residue 206 having a shape as shown by symbol A will be removed. occurs. If the excavation equipment collides with the excavation residue 206, the equipment may be damaged or become unable to excavate. For this reason, conventional methods have been to detect changes in sounds, vibrations, etc. during excavation, or to detect changes in excavation resistance using load cells, etc., and determine an abnormality when there is a change above a predetermined level. However, after the excavation equipment is temporarily stopped, such excavation residue 206 is manually cut and removed over time. For this reason, it has been difficult to automate the drilling equipment. The present invention aims to solve these problems.

(D) Means for Solving the Problems The present invention solves abnormalities in the operation of a nozzle (18) that injects a liquid jet by abnormalities in the speed or drive current value of the nozzle drive device (10 and/or 12). The nozzle is detected and moved backward, returning the nozzle to the coordinates before the abnormality occurred.
The above problem is solved by re-excavating the abnormal area and then restarting normal excavation work. That is, in the groove excavation method using a liquid jet according to the present invention, the nozzle that injects the liquid jet is driven at a constant speed, and the operating speed of the nozzle in the direction perpendicular to the axis of the excavation direction is reduced or , detects that the operation has stopped, determines that there is an abnormality in excavation, moves the nozzle backward, returns the nozzle to the coordinates before the abnormality occurred, re-excavates the abnormal area, and resumes normal excavation operation. I try to do that.

In addition, in a case where the nozzle that injects a liquid jet is driven at variable speed during one excavation stroke, the set movement speed for each coordinate in the direction perpendicular to the axis of the excavation direction during one excavation stroke of the nozzle is memorized in advance. , the actual movement speed of the nozzle during excavation for each coordinate is compared with the above set movement speed, and if there is a speed difference between the two speeds that is greater than a preset value, it is determined that there is an abnormality in excavation, and the nozzle is moved back. After returning the nozzle to the coordinates before the abnormality occurred and re-excavating the abnormal area, normal excavation operation is resumed.

The re-excavation of the abnormal location is preferably carried out at a speed lower than the speed preset for the corresponding coordinates and over an area range preset for re-excavation.

Furthermore, the groove excavation device using the liquid jet of the present invention has the following features:
A frame that can be moved and fixed in place (
2), a movable base (4) movable on the frame (2) by a forward and backward movement device (6), and a lever (20) at the tip mounted on the movable base (4) that swings within one plane. a rocking device (10) that can move the nozzle mounting member (16) at the tip mounted on the movable table (4) repeatedly, including a motion component perpendicular to the above-mentioned one plane; The device (12) and the nozzle attachment member (16)
) is attached to a nozzle (1) that can spray a liquid jet.
8), a rocking device (10) and a repetitive exercise device (12).
) of either or both of the prime movers (46 and/or 6
6) Abnormality detection sensor (78 or 79) attached to the part
) and the signal from the abnormality detection sensor (78 or 79) to manually determine the abnormality in the operation, move the nozzle (18) to the coordinates before the abnormality occurred, re-excavate, return to the coordinates of the abnormality point, a control device (73) that commands the restart of normal excavation;
The nozzle mounting member (16) is supported by the lever (20) so as to be able to move repeatedly. In addition,
Reference numerals in parentheses indicate corresponding members in the embodiments described below.

(e) Effect (effect of claim 1) For example, a rotational position sensor (
The rotational position sensor generates a signal at fixed time intervals by the drive shaft of the nozzle drive device, which rotates at a constant speed when there is no abnormality, and this detection signal is sent to the control device. entered and compared to the preset allowed time interval. If this detection signal deviates from the allowable value, the control device determines that there is an abnormality in the rotational speed, and first sends a signal to the forward/backward movement device to move the nozzle backward from that point. Next, the control device moves the nozzle to the coordinates before the abnormality occurred, and re-excavates the abnormal area. This abnormal area is generally caused by foreign matter that is harder than other parts and has a certain size, so the size of the abnormal area must be determined in advance at a speed lower than the normal excavation speed. It is a good idea to excavate within a predetermined area range. Once the abnormal area has been excavated, normal excavation is resumed.

(Effect of Claim 2) The moving speed of the nozzle during one excavation stroke is made different depending on the coordinate position, and the speed for each position is stored in a memory provided in the control device. For example, a row encoder (abnormality detection sensor) attached to the drive shaft of a nozzle drive device detects the rotation angle of the drive shaft at each position during one excavation process, and this detection signal is sent to the control device. the actual velocity is calculated and compared with the velocity of the corresponding stored position. The control device determines that an abnormality has occurred when the difference between these two values becomes larger than a preset value, and the control device first sends a signal to the forward and backward movement device to move the nozzle backward from that point. send.

The subsequent operations are performed according to the same procedure as in the case of item 1 above, and after the completion of excavation of the abnormal area, normal operation is resumed.

By doing this, even if an abnormality occurs such as excavation residue, it is possible to reliably detect the excavation residue and automatically remove the excavation residue, instead of manually removing the excavation residue. Once the re-excavation is complete, normal excavation operations can be resumed.

(F) Embodiment Figures 2 and 3 show an example of a groove excavation device using a liquid jet to which the present invention is applied. Moving table 4 on frame 2
is provided so as to be movable in the left and right directions in FIGS. 2 and 3. The frame 2 itself is attached to the tip of a robot arm (not shown), and can be moved to a desired position and kept stationary. device) via a pulley 7 and belt 8, and its position is controlled.
A tie member 5 fixed to the belt 8 is attached to the bottom surface of the movable table 4. The movable table 4 is provided with a rocking device 10 and a repetitive exercise device 12. The rocking device 10 and the repetitive exercise device 12 will be described below.

(Swinging device 10) The swinging device 10 includes a Y-shaped lever 20 having forked portions 20a and 20b, and one end 24a fitted into a slot at the tip of the forked portion 20a, and rotated with a bottle 22. A link 24 is movably supported and has a connecting hole on the other end side 24b, and one end side 28a rotatably supports the forked portion 20b with a bottle 26, and an overhang portion 28b is on the other end side. The provided arm 28 and the link 24
A bottle 3 is attached to one end side 24a and one end side 28a of the arm 28.
links 34 supported by 0 and 32, respectively;
It has a drive device 36 that swings the link 24 in the left-right direction in FIG. 2 with the bin 32 as a fulcrum, and by swinging the link 24 in the left-right direction,
0 can be swung up and down in a plane parallel to the plane of the paper in FIG. 2 using the bin 26 as a fulcrum.

Note that the lever 20 is equipped with a repetitive exercise device 12, which will be described later.
The hole 20c for attaching the fork 56 and the bearing rotatably supporting the shaft of the eccentric cam 60, which will be described later, are in the part 2.
0d is provided.

The drive device 36 includes a cylindrical case 37 having a rocking bearing part 37a at one end, and a screw having one end connected to the rocking bearing part 37a and the other end connected to the link 24 and the arm 28 by a pin 30. A shaft 38, a rod-shaped nut 40 screwed thereto, a gear 42 integrally attached to the nut 40 and rotatably supported within the case 37 by a bearing 50, a gear 44 meshing with this, and a case. 37
A motor 46 is mounted inside the motor 46 and drives a gear 44. A reduction gear 52 and a positioning encoder 54 are attached to the motor 46. The swing bearing portion 37a of the case 37 is swingably supported by a trunnion mechanism 48 fixed to the movable table 4. As a result, even if the link 24 moves in the horizontal direction in the figure with the bin 32 as the fulcrum and the distance between the shafts with the arm 28 changes, the case 37 swings in the vertical direction in the figure with the trunnion shaft of the trunnion mechanism 48 as the fulcrum. This makes it possible to follow changes in the distance between the axes. The driving device 36 is configured to reverse its rotational direction at predetermined intervals, so that the lever 20 can be swung at a predetermined interval in the angle range shown from +β to -β in FIG. It is possible.

(Repetitive exercise device 12) The repetitive exercise device 12 has a shaft portion 56a that fits into the hole 20c of the lever 20 of the swinging device 10, and a fork 56 with a slot on one end, and a fork 56 with a slot on one end. A head 16 which is fitted in a slot and is rotatably supported by a pin 58 and has a nozzle attachment part 16a at one end and a spherical bearing part 16b at the other end, and one end of the shaft is eccentric and has a spherical end 60a at the tip. is formed, and the spherical receiver is fitted with the portion 16b, and a flat portion 60b is formed at the other end.
an eccentric cam 60 formed with an eccentric cam 60; a universal joint 62 having a joint flat part 62a at one end that is combined with the joint flat part 60b of the eccentric cam 60; and a universal joint 62 having a joint flat part 62b at the other end; It has a rotary joint 64 that is combined with the rotary joint 62b, and a rotation drive device 66 that rotates the rotary joint 64. Note that the shaft portion of the eccentric cam 60 is
The bearing of the lever 20 of the swing device 10 is rotatably supported by the portion 20d. The universal joint 62 has a spline hole 68 in its intermediate portion and a spline shaft 70 that is fitted into the spline hole 68 so as to be movable in the axial direction, thereby allowing it to expand and contract in the axial direction. Rotary drive device 6
6 is attached with a speed reducer 72 and a motor 76. By rotationally driving the rotary joint 64 by the rotary drive device 66, it is possible to repeatedly move the spherical end 60a of the eccentric cam 60 in a circular motion. That is, the head 16 is attached to the shaft portion 56a of the fork 56 and the bottle 58.
It is possible to perform a repeated motion including a motion component in a direction perpendicular to the plane of the paper in FIG. 2 using the fulcrum as a fulcrum.

On the other hand, at the rear of the motor 76, there is a low encoder 78.
is attached, and the shaft of the rotary encoder 78 is connected to the rotating shaft of the motor 76 to generate an angle signal at each predetermined angle during one revolution of the motor 76. This signal is input to the control device 73, converted into a speed based on the time measured by a timer built in the control device 73, and treated as the actual speed. The control device 73 compares the actual speed and the set speed at every predetermined angle during one rotation to check whether the difference is within the allowable speed difference. It is not necessary to set the speed fluctuation detection level by the rotary encoder 78 to a very high level, for example,
It is sufficient that the controller 73 determines that there is an "abnormality" if the speed remains below 0% for one second or more.

Further, the nozzle attachment portion 16a of the head 16 includes:
A nozzle 18 is attached for ejecting a liquid jet. A high-pressure water hose 82 and an abrasive material hose 84 are attached to the head 16 , and high-pressure water from the high-pressure water hose 82 and abrasive material from the abrasive material hose 84 are mixed inside and sent to the nozzle 18 . A mixing chamber 80 is provided for feeding. High pressure water is supplied to the high pressure water hose 82 from a high pressure water pump (not shown), and the abrasive material hose 84 is supplied with high pressure water.
The abrasive is supplied from an abrasive supply pump (not shown). The nozzle 18 is capable of injecting a grinding liquid obtained by mixing high-pressure water and abrasive material in a mixing chamber 80 onto an excavated surface 86 as a liquid jet.

A cover 88 is provided to separate the movable table 4 side and the jet injection section 14 side. The cover 88 is connected to the link 24
．． Arm 28. The two hoses 82, 84 and the universal joint 62 are provided so as to pass through, thereby preventing contamination of equipment provided on the movable platform 4 side due to scattering of the liquid jet.

Next, the operation of this device will be explained. First, the frame 2 is positioned and fixed by a robot arm (not shown). The movable table 4 is moved back to the left from the illustrated position in FIGS. 2 and 3, so that the nozzle 18 faces the excavation surface 86. In this state, the jet starts ejecting. That is, high-pressure water and abrasive material are supplied to the head 16 through the high-pressure water hose 82 and the abrasive material hose 84, respectively, the two are mixed in the mixing chamber 80, and a jet containing the abrasive material is ejected from the nozzle 18. The jet ejected from the nozzle 18 cuts concrete, rock, etc. with the kinetic energy of the high-pressure water and abrasive material. At the same time, the rotary drive device 66 is driven to rotate the rotary joint 64. This causes the universal joint 62 to rotate, causing the eccentric cam 60 to rotate. As a result, the head 16 repeatedly moves in a circular motion in the angular range shown from +α to -α in FIG. A circular hole will be excavated.

On the other hand, the motor 46 of the drive device 36 is driven to drive the reducer 52.
The gear 44 is rotated via. This causes the gear 42.
The nut 4° is rotated, and the screw shaft 38 is moved in the axial direction. The link 24 swings from side to side in FIG.
It swings in a plane parallel to the plane of the paper in the range from +β to 1β with the fulcrum at .

That is, as shown in FIG. 5, the nozzle 18 performs excavation by swinging in the lateral direction while repeatedly moving in a circular motion.

Next, the present invention using this device will be explained in detail. The encoder 78 generates a signal at regular time intervals by the drive shaft of the repetitive motion device 12 rotating at a constant speed, and this detection signal is input to the control device and compared with a preset allowable time interval. If this detection signal deviates from the allowable value, the control device determines that there is an abnormality in the rotational speed, and first sends a signal to the motor 6 that causes the nozzle 18 to retreat from that location. Next, the control device moves the nozzle 18 to the coordinates before the occurrence of the abnormality, and re-excavates the abnormal area. This abnormal area is generally caused by foreign objects such as reinforcing bars and stones that are harder than other parts, and has a certain size, so it can be excavated at a speed lower than the normal excavation speed.
Excavate within a preset area based on the size of the abnormal area. Until the excavation of the abnormal area is completed,
Re-excavation is repeated, and when re-excavation is completed, normal excavation is resumed.

The above operation will be explained based on FIG. Now, the tip of the nozzle 18 is at Nl, and accordingly, the rotation center of the pin 26 is at PL, and is in the middle of swinging from -β to +β direction, and while excavating a groove of depth H, N1 Suppose that an abnormality in excavation is detected at . The motor 6 rotates in response to a command from the control device 73, and the tip of the nozzle 18 moves from point N1 to point N.
Go back to 2. This retreat distance is 1.5 to 1.5 of the excavation depth H.
2.0 times is desirable. The control device 73 drives the motor 45 of the rocking device 10 to move the nozzle 18 at the coordinates before the occurrence of the abnormality.
And the tip of the nozzle 18 is returned to point N3 facing point N1.

Excavation is performed again by repeatedly moving the angle between 0 and 10 around point N3. That is, re-excavation is performed by moving the tip of the nozzle 18 in a circular motion across the page in an angular range from point N4 to point N5. When the re-excavation is completed, move the tip of the nozzle 18 from point N3 to point N2 by reversing the above-mentioned operation to point N2.
Return to step 1 and resume normal excavation work.

FIG. 4 shows a second embodiment of the present invention. The drive device 66 is
It is composed of a motor 66, a reduction gear 72, and a torque limiter 74 provided between both members. Reducer 7
Two sensor cams 77 are attached to the output shaft of No. 2 at rotation angle positions shifted by 180 degrees, and two proximity sensors 7 are attached to the movable table 4 to detect the passage of the sensor cams 77.
9 is attached. That is, in this second embodiment, the rotary encoder 78 of the first embodiment shown in FIG.
Instead, a proximity sensor 79 is used as a sensor cam 77 and an abnormality detection sensor.

Next, the operation of this second embodiment will be explained. If the operation of the repetitive motion device 12 is obstructed by a hard foreign object during excavation, the torque limiter 74 limits the drive torque of the motor 76 that is transmitted to the reducer 72, thereby damaging the repetitive motion device 12 and the nozzle 18. protect from Proximity sensor 7
9 measures the time required for each half rotation of the speed reducer 72 and outputs it to the control device 73. The control device 73 compares and checks the preset seconds and the measured seconds, and if it detects a time longer than the set seconds, it commands a re-excavation operation.

Note that an ammeter for detecting the current of the motor 76 may be provided, and an abnormality in the rotation of the motor 78 may be detected based on an abnormality in the current value. Furthermore, the motor 54 of the swinging device 10 may be provided with an abnormality detection sensor for detecting such an abnormality in excavation.

(G) As described in detail, according to the present invention, even if an abnormality such as excavation residue occurs, the excavation residue is reliably detected without having to manually remove the excavation residue. do,
Re-excavation will be repeated automatically until this is removed, and once the re-excavation is complete, normal excavation work can be resumed.

[Brief explanation of drawings]

FIG. 1 is a diagram explaining the operation of the nozzle when an excavation abnormality occurs according to the method of the present invention, FIG.
The figure is a sectional view taken along the cross-sectional line ■-■ in FIG. 2, FIG. 4 is a front view of the groove excavation device using a liquid jet of the second embodiment, and FIG. 5 is a diagram explaining the trajectory of the nozzle 18. , FIG. 6 is a diagram illustrating an excavation situation by a groove excavation device using a conventional liquid jet, and FIG. 7 is a diagram illustrating an excavation residue generated during groove excavation. 6... Motor (forward/backward movement device), 10... Rocking device (
12... Repetitive movement device (nozzle drive device) 18... Nozzle, 73... Control device, 78... Rotary encoder (abnormality detection sensor)
, 79... Proximity sensor (abnormality detection sensor).

Claims (1)

[Claims] 1. In a groove excavation method using a liquid jet for forming a deep groove in an excavated part, the operating speed of a nozzle that injects a liquid jet in a direction perpendicular to the axis in the excavation direction is reduced; or , detects that the operation has stopped, determines that there is an abnormality in excavation, moves the nozzle backward, returns the nozzle to the coordinates before the abnormality occurred, re-excavates the abnormal area, and resumes normal excavation operation. A trench excavation method using a liquid jet characterized by: 2. In a groove excavation method using a liquid jet to form a deep groove in an excavated part, the moving speed of the nozzle that injects the liquid jet is determined in advance for each coordinate in a direction perpendicular to the axis of the excavation direction during one excavation stroke. The actual moving speed for each coordinate of the nozzle during excavation is memorized and compared with the above-mentioned set moving speed, and if there is a speed difference between the two speeds that is greater than the preset value, an abnormality in excavation is determined. A groove excavation method using a liquid jet characterized by retracting the nozzle, returning the nozzle to the coordinates before the occurrence of the abnormality, re-excavating the abnormal location, and then restarting normal excavation operation. 3. The re-excavation of the abnormal location is performed at a speed lower than the speed set in advance for the corresponding coordinates and over an area range set in advance for re-excavation. Trench excavation method using liquid jet. 4. A frame (2) that can be moved and fixed in a predetermined position, a movable base (4) that can be moved on the frame (2) by a forward and backward movement device (6), and mounted on the movable base (4). A swinging device (10) capable of swinging a lever (20) at the tip in one plane, and a nozzle mounting member (16) at the tip mounted on a moving table (4) in the same plane. A repetitive motion device (12) capable of performing repetitive motion including orthogonal motion components, and a nozzle attachment member (
16) and a nozzle (18) capable of ejecting a liquid jet, a rocking device (10) and a repetitive movement device (
The abnormality detection sensor (78 or 79) attached to the prime mover (46 and/or 66) of either or both of 12) and the signal from the abnormality detection sensor (78 or 79) are input to detect abnormality in operation. A control device (73) that makes a judgment and instructs the nozzle (18) to move to the coordinates before the abnormality occurred, re-excavate, return to the coordinates of the abnormality point, and resume normal excavation.
and a nozzle mounting member (16) supported for repeatable movement on a lever (20).