JPS59223169A - Method for automatically copying actual article - Google Patents

Abstract

PURPOSE:To perform highly reliable automatic copying, by installing a sensor which makes the distance between a torch and work to a constant and another sensor which detects a rotating direction with the above-mentioned sensor as a reference and finding a work starting point by means of the two sensors. CONSTITUTION:A cutting torch 15 is positioned to a starting point P0 and a sensor 16 is faced to the direction of Y axis. Coordinates of a virtual point P2 in the vicinity of the work starting point of a curve plate W and the angle theta2 of its normal are inputted into a computer. Then a point P1 separated from the point P2 with a fixed distance l at the angle theta2 is calculated and a torch 16 is moved to the calculated point P1. When the torch 16 is moved to the point P1, the sensor 16 contacts a copying surface (h). The sensor 16 is moved towards the work starting end of the copying surface (h) based on the information on the sensors 16 and 17 and, when the sensor 16 reaches a point P3, the sensor 16 is separated from the copying surface (h). Then points P3' and P3'' which are separated from the curve plate W by prescribed distances are calculated and the sensor 16 is moved to the points P3' and P3'' while the attitude angle of the sensor 16 is maintained. The sensor 16 is further moved to a point P4 and contacts the copying surface (h), and thus, true copying is performed.

Description

[Detailed Description of the Invention] The present invention is a so-called automatic welding (cutting) robot that performs beveling or fillet welding on the edge of a flat plate or a curved plate of arbitrary shape. This paper relates to an automatic physical tracing method.

Generally, this type of automatic welding robot welds automatically by moving the torch along the welding line of the workpiece while controlling the position of the torch based on commands from a control device. In this case, it was necessary to input data by teaching the welding line to the control device or input No. control data. However, at present, this data input work is extremely complicated and takes several hours of effort.

An object of the present invention is to provide an automatic spot tracing method that eliminates the above-mentioned conventional drawbacks and can easily perform groove cutting or fillet welding even on workpieces with high dimensional accuracy.

An embodiment of the present invention will be described in detail below.

First, in explaining an embodiment of the method of the present invention, an embodiment of the apparatus used in the method will be described in detail with reference to FIG. A cart which is the first moving mechanism in the device 1, and which is placed on the rail /I/3 extending in the X-axis direction of the three-dimensional orthogonal coordinate system in the automatic spot tracing method of this example,
The trolley 2 has a first servo motor 4 installed in a part thereof.
As mentioned above, it is moved on /I/2. A screw strut 5 is erected on the cart 2, and a second moving mechanism 6 is installed on the screw strut 5, and this second moving mechanism 6 is installed at the upper end of the screw strut 5. The second
It is moved in the Z-axis direction in the above-mentioned cubic orthogonal coordinate system by the servo motor 7 via the screw column 5.

A screw arm 8 extends horizontally from the second moving mechanism 6, a fifth moving mechanism 9 is installed on this screw arm 8, and this sixth moving mechanism 9 is connected to the second moving mechanism 6. A sixth servo motor 10 installed in a part of the m-structure 6 moves it in the Y-axis direction in the cubic rectangular coordinate system via the screw arm 8.

At the bottom of the third moving mechanism 9, there is installed a rotation mechanism 11 whose rotation center is an axis in the Z-axis direction, that is, the screw column 5 and a flat material 1'Jll (not shown). The mechanism 11 is rotated by an adjacent fourth servo motor 12 via a gear train 16.

A T- or C-shaped arm 14 is integrally attached to the rotation axis of the rotation mechanism 11, and a cutting torch 15 is obliquely installed approximately in the center of the arm 14. Also, approximately at the bottom of the arm 14, first and second
, the third sensor 16, 1718 is connected to the movable rod 19, 20.2
1, respectively. That is, for the first sensor 16, a movable rod 19 is pivoted in the vertical direction to the tip of the lower part of the arm 14 with a pin 22,
The lower end of this movable rod 19, that is, the movable rod 20 is attached horizontally directly below the aforementioned cutting torch 15. As for the second sensor 17, the movable rod 20 is pinned to the center of the lower part of the arm 14. 23, and is pivoted in the vertical direction at the lower end of the movable rod 20, which is slightly below the first sensor 16 as shown in FIG. 4 and ahead of the first sensor 16 by an amount a as shown in FIG. As for the third sensor 18, a movable rod 21 is horizontally pivoted to the rear end of the lower part of the arm 14 with a pin 24, and the tip of the movable rod 21 That is, it is attached directly below the cutting torch 15 facing downward. In addition, each movable rod 19, 20, 21 has a spring 25, 26, .
27, and a first,
Second and third differential transformers 28, 29, 30 are provided, and the outputs of the respective sensors 16, 17, 18 are outputted by the differential transformers 28, 29, 60.

As for the aforementioned end 1, second and third sensors 16°18, the first and second sensors 16°17 are pressed against the curved surface of the curved plate W, which is the workpiece, as shown in FIG. As shown in the block diagram, the first and second sensors 1
The rotation mechanism 11 is rotated by the fourth servo motor 12, which receives an input proportional to the output difference between the motors 6 and 17. That is, the cutting torch 15 is rotated around the bevel cutting point of the cutting torch 15, and the outputs of the sensors 16 and 17 are input to the computer so that the difference between them becomes 0.
The direction of the cutting torch 15 is controlled so as to maintain the normal direction of the curved plate W by rotating the rotating mechanism 11 in accordance with the bending of the curved plate W as a workpiece. In addition, first and third servo motors 4, which are involved in the X-axis and Y-axis directions, receive an input corresponding to an output proportional to the deviation of the curved plate W at the tip of the cutting torch 15 of the first sensor 16. 10, the output of the first sensor 16 is input to the computer, and the position of the tip of the cutting torch 15 in the X-axis and Y-axis directions is controlled so that the output value becomes 0. Then, the sixth sensor 18 is connected to the curved plate W.
In order to make the cutting line of the edge of the 6th sensor 18 at a constant height above the reference surface, an input proportional to the output of this sixth sensor 18 is pressed against the reference surface, as shown in the block diagram of FIG. The second servo motor 7 inputs the output of the sensor 18 to the computer, and controls the position of the tip of the cutting torch 15 in the Y-axis direction so that the value becomes zero. In addition, in controlling the position of the tip of the cutting torch 15, the XIF generated by the rotation by the fourth servo motor 12
The rotation angle θ of the cutting torch 15 with respect to the l11 direction is measured by an encoder 61 installed at the lower end of the rotation shaft (not shown) of the rotation mechanism 11, and the rotation angle θ is measured by a micrometer as shown in the block diagram of FIG. A reference speed that is recorded in the computer and specified in advance based on the θ angle is divided into the X direction and the Y direction, and the , speed commands to the first and sixth servo motors 4, 10 in the Y-axis direction are controlled by the computer.

Next, the automatic tracing method of this embodiment will be explained in detail with reference to the flowchart of FIG.

First, as shown in FIG. 7(a), when starting the work, the cutting torch 15 is located at the origin PO of the X-axis and Y@il coordinates, and the first sensor 16 is oriented in the Y-axis direction. The points match.

When the workpiece, the curved plate W, is fixed to a support stand (not shown) and preparation for work is completed, the coordinates of a virtual point P2 near the work start point of the curved plate W and the approximate normal angle θ2 of the virtual point P2 are input into the computer. (Step ■). Based on this input, 21 points are calculated at a constant distance l from the virtual point P2 at a normal angle θ2 (step ■), and the reference speed (designated cutting speed) Vs in the POP1 direction is set on the X axis and Y@. The speed is calculated by dividing it (step ■), and it moves in the POP1 direction at a reference speed v8 (step ■).

When you reach 21 points, stop and step ■) PIF2
After calculating the divided speeds of the X-axis and Y-axis with respect to the reference speed v8 in the direction (step), the PIF moves in the 2 direction (step ■). Then, when the first sensor 16 comes into contact with the contoured surface, the movement is stopped (step [phase]) according to the contoured surface detection signal (this point is indicated by point P2'). In this case, the output of the first sensor 16 becomes 0V (1 volt) by the first differential transformer 28.

Next, the first and second sensors 16 and 17 move the guide in the opposite direction, that is, in the direction of the work starting end face of the guide, while following the information from the sensors 16 and 17 (step 0). .

Then, when the first sensor 16 reaches the 23rd point, the first differential transformer 28 associated with the sensor 16 is removed.
The output of is no longer Ov. Then, it receives this signal and stops (step 0).

Since the sensor 16 is out of the tracing line at these 23 points, if this trench laying (cutting work) is started, the sensor 16 will come into contact with the work W and be damaged, so at least the sensor 16 is out of the tracing line. It is necessary to return it until it rests on the edge.

Therefore, the coordinates of 23 points are read (step 0), and a predetermined image is drawn from the workpiece W (at least the distance p 3', (x 3±Δ/,
P3 (X5±ΔX1Y3±ΔY, Z5
, θ3 and Δθ) and the attitude angle are calculated (step ■
) After calculating the dividing speed of the X-axis and Y-axis in the P3P3 direction (step [phase]), as shown in Fig. Move to (step o) Stop at point L1 (step). Then move further in the P3P3 direction (step 0) L
Stop at point P5 (step @l).

Next, calculate the divided speed of the X'@Y axis in the P3P4 direction (step) and move in the LP3P4 direction (step @). When the sensor 16 comes into contact with the profile surface (point P4), the machine stops according to the profile detection signal (step, de).

Next, perform book tracing (cutting work). This is sensor 16.
This is done by moving the train at a reference speed v8 based on the information from 17.18 (step 0).

When the process reaches the end of the process, that is, the end of the profile, the second sensor 17 moves away from the profile, but when this signal is detected (step 2), control of the torch 15 in the normal angle direction is stopped. In this case, the profile control (X, Y, Z@#) is continued, and when the first sensor 16 comes off the profile, this is detected (step ■) and stopped (step
). Next, read the coordinates of this stopping point and (step ■)
, - Retreat by a predetermined amount in the assembly normal direction (step @) L (P'6
), and then moves to a specified arbitrary point p□ (which may also be the origin PO) (step ■), and the work is completed.

In the above explanation, the movement of the sensors 16, 17 was described, but the differential transformer 26.29 outputs the output as the sensor 16.17 moves, and the reservomotor 4, 10.1
As described above, the cutting torch 15 is controlled in position as the cutting torch 2 rotates.

The present invention can also be similarly applied to the case where the cutting torch 15 is replaced with a welding torch 15 to perform fillet welding on the workpiece 1 as shown in FIG. 6 (0) (b).

As explained above, in the present invention, a cutting or welding torch is mounted on a cart that moves in the longitudinal direction of a flat plate or a curved plate workpiece, and a cutting or welding torch is mounted directly below the torch between the torch and the workpiece. A '1st sensor is provided to keep the distance constant, and a second sensor is provided in parallel at a position preceding the nuclear sensor to detect the direction of rotation based on this first sensor. This is an automatic method for tracing the actual object in which the position is controlled by commands from a control device based on input information from both sensors installed, and the coordinates and normal angle of a virtual point P2 on the workpiece near the work start point of the workpiece are approximated. is input, the torch is moved from the starting point PO to the virtual point P2 based on this, and then automatic tracing of the actual object is performed to the work starting point side of the workpiece based on the information from both of the sensors installed in parallel, and the information of the sensors installed in parallel is Since the work starting point is determined by detecting the position where one side is off the work, there is no need to enter data by teaching the cutting IT line or welding line of the work or input NC control data as in the past. Good too,
In addition, since the work start position is detected using a sensor for tracing the actual object, there is no need for a special sensor for this purpose, and therefore, it is possible to trace eye movement with reliability, rather than the device being a surface element. .

In addition, since it automatically follows the actual pattern, it has the advantage of being able to easily handle workpieces with poor dimensions and products produced in small quantities.

[Brief explanation of drawings]

The figures show one embodiment of the present invention, and Fig. 1 (b) is a perspective view schematically illustrating the bevel cutting of the edge of a curved plate; Fig. 2 is a perspective view schematically showing the entire device of this example, Fig. 3 is a plan view schematically showing the planar positional relationship between the cutting torch and the first and second sensors, and Fig. 4 is the same as the cutting torch. FIG. 5 is a block diagram of the control device of this example, and FIG. 6) is a front view schematically showing the lateral positional relationship of the first, second, and third sensors. A plan view schematically showing the positional relationship, FIG. 6(B) is a front view of the same, FIG. It is a flowchart of an example. DESCRIPTION OF SYMBOLS 1... Automatic object tracing device 15... Cutting torch 16... First sensor 17... Second sensor 18... Third sensor W... Curved surface
Extract applicant Nippon Sharyo Mfg. Co., Ltd.
Patent Attorney Hidehiko Okada

Claims (1)

[Claims] A cutting or welding torch is mounted on a trolley that moves in the longitudinal direction of the workpiece, whether it is a flat plate or a curved plate.
A first sensor is provided almost directly below the torch to keep the distance between the torch and the workpiece constant, and a second sensor is provided in advance of the sensor to detect the direction of rotation based on the first sensor. A method for automatically tracing an actual object, the position being controlled by a command from a control device based on input information from both of the sensors arranged in parallel,
Input the approximate coordinates and normal angle of a virtual point P2 on the workpiece near the start point of the workpiece, move the torch from the start point PO to the virtual point P2 based on these, and then move the torch from the start point PO to the virtual point P2. A method for automatically tracing the work piece, characterized in that the work piece is automatically traced to the work start point side of the work piece based on information, and the position where one of the sensors installed in parallel is removed from the work piece is detected to determine the work start point. .