JPH03184748A - Position accuracy confirmation method and device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Application in Industry A) The present invention relates to a position accuracy confirmation method and apparatus for confirming the positioning accuracy of various types of workpieces in, for example, laser processing.

(Prior art) Conventionally, when welding or cutting a workpiece with a processing tool such as a laser welding machine or a laser cutting machine, the distance between the processing part of the workpiece and the head of the laser processing tool has to be set strictly. need to be managed.

That is, as shown in FIG. 5, the laser beam is focused by the reflecting mirror 31 and the condensing lens 32 of the processing tool head 3 and irradiated onto the processing area S of the workpiece W, and the thermal energy with high power density is generated at the processing area S. In order to achieve this, it is necessary to maintain the distance between the condenser lens 32 and the processed portion S within the allowable value (±α) of the processing conditions. For this reason, as a device for controlling the distance between the processing tool head and the workpiece processing section, a Z-axis control device is known, for example, as disclosed in Japanese Patent Application Laid-Open No. 60-3994. A plurality of distance measuring sensors are installed on the head side of the machine, and the head position is corrected and moved for control.

(Problem to be Solved by the Invention) However, in the apparatus such as the above-mentioned Japanese Patent Application Laid-Open No. 60-3994, when processing is attempted while moving the processing tool head side by a numerical control device, etc. There are problems in that the control of the processing tool head becomes complicated, the weight of the processing tool head itself increases, and the structure becomes complicated.

(Means for Solving the Problem) In order to solve the problem, the present invention provides a plurality of laser deviation sensors on the opposite side of the workpiece from the processing tool head, and uses these laser deviation sensors to detect the workpiece at a plurality of locations. The distance to the outer surface of the back side was measured, and these measured values were compared with reference values at each location to confirm that the deviation errors at all locations were within the allowable value, thereby confirming the accuracy of the machining position.

In addition, a receiving member is provided whose height position can be adjusted depending on the type of workpiece.

(Function) If the shape of the workpiece is constant, it is possible to maintain positional accuracy on the front side by ensuring accuracy on the back side. In addition, since the laser deviation sensor is installed on the opposite side of the processing tool head, the structure of the processing tool head is simple, and numerical control prevents interference even when the processing tool head moves along the work surface. . Further, by providing a receiving member whose height can be freely adjusted depending on the type of workpiece, accurate positioning of the workpiece can be easily performed.

(Example) The position accuracy confirmation method and device of the present invention will be explained based on the attached drawings.

FIG. 1 is an overall front view of a position accuracy confirmation device of the present invention that is integrated with a workpiece positioning device for a laser welding device;
FIG. 2 is a plan view of the position accuracy confirmation device, FIG. 3 is an enlarged view showing the receiving member, and FIG. 4 is an enlarged view showing the laser deviation sensor.

As shown in FIG. 1, the position accuracy confirmation device of the present invention is provided integrally with a positioning device 1 that positions a workpiece W during welding processing by a laser welding machine 2, so that a workpiece W such as an automobile engine cover is It is configured to confirm that the head 3 is located at a predetermined distance from the head 3 of No. 2.

The laser welding machine 2 includes an X-axis moving member 6 that is movable in the X-axis direction (front and back direction in the first drawing) by a rack 6a on a guide 5a of a base member 5 supported by a plurality of supports 4, for example. Along the guide 6b of this X-axis moving member 6,
Y-axis moving member 7 that is movable in the axial direction (horizontal direction in Figure 1)
is provided. The head 3 is provided at the lower end of the Z-axis moving member 8 provided on the Y-axis moving member 7,
The Z-axis moving member 8 is movable in the Z-axis direction (vertical direction in FIG. 1). And these X-axis moving members 6
, the Y-axis moving member 7, and the Z-axis moving member 8 perform welding while moving along a predetermined trajectory along the work surface under NC control or program control.

Positioning device 1 provided below this laser welding machine 2
is equipped with a plurality of receiving members 12.12... on a plurality of bases 11゜11... rising from the floor, and these receiving members 12.12... Motor 13
is connected. As shown in FIG. The indexing motors 13 are provided in pairs at nine locations.

At the center of these bases 11 is a suction cup device 14 that can be moved up and down.
A plurality of suction cups 15 . . . that can stick to the back surface of the workpiece W are provided on the upper part of the suction cup device 14 . The above-mentioned receiving member 12 is configured such that the height position of the workpiece receiving portion is variable by the indexing motor 13,
For example, as shown in FIG. 3, receiving blocks 17a, 17b, 17c, and 17d of different shapes are attached to the four sides around the index table 16 that rotates together with the motor shaft 13a, and each receiving block 17 has two heights. By providing different workpiece receiving parts, it is configured to be able to accommodate eight different types of workpieces W.

The height of the receiving part of the receiving block 17 is adjusted in advance so that no matter which workpiece W is supported, the distance between the head 3 of the laser welding machine shown in FIG. 1 and the workpiece surface directly below it is constant. has been done.

On the other hand, on the base 11 that supports the peripheral portion of the workpiece W, respective laser deflection sensors 21 as shown in FIG. 2 are provided. As shown in FIG. 4, this laser deviation sensor 21 is configured to emit a laser beam upward and measure the distance by receiving reflected waves from the outer surface of the workpiece. In some cases, there are four locations.

The actual value of the distance measured by the laser deflection sensor 21 is sent to the arithmetic unit 22 shown in figure S1. This arithmetic device 22 stores reference values for each measurement part depending on the type of workpiece W, and compares the sent actual measurement value with the reference value to determine the difference. If the difference is not within the allowable value for the welding conditions at any one point, the signal transmitter 23 issues a warning, and when the difference falls within the allowable value at all measuring points, the next work command is issued. That's what I do. In the case of this embodiment, the allowable distance range ±α between the head 3 and the processing portion of the workpiece W is set to ±0.5 mm.

The confirmation method using the position accuracy confirmation device configured in this way is as follows.
It is as follows.

A model discrimination device is provided in the process before the welding device, and before the workpiece W is carried into the positioning device 1 of the wood laser welding machine 2, the index table has already been identified by the model signal received from the model discrimination device. The 16 receiving blocks 17 are indexed and rotated to positions corresponding to the model. Furthermore, the welding program of the laser welder 2 has also been selected.

Next, when the workpiece W is carried in and placed on the receiving block 17, the suction cup device 14 is raised and suction is applied from the suction cup 15 to the back surface of the workpiece to fix the workpiece.

When placing this work W, the laser deviation sensor 21 is activated because there is a high possibility that the work W is positioned out of the correct position, partly because the area around the receiving part on the back side of the work is a curved part. The positional accuracy of each measuring section is measured, and as mentioned above, if even one location is not within the allowable range, an alarm is issued to notify that position correction is necessary. As a result of the correction, if it falls within the allowable value, it means that the welding conditions have been set, and the head 3 moves according to the program to proceed with the welding work.

In this embodiment, the position is corrected manually, but the correction operation may of course be automated.

Moreover, it can be used not only in laser welding machines but also in a wide range of fields such as laser cutting machines and beam welding.

(Effects of the Invention) As described above, in the position accuracy confirmation method and device of the present invention, the laser deviation sensor is provided at a location different from the processing tool head, and on the opposite side where it does not interfere with the movement of the head. The device itself can be constructed simply and inexpensively.

Furthermore, since the height of the receiving member is adjustable, the configuration of the welding machine can be made simpler, and it is convenient because it can quickly handle all types of workpieces.

[Brief explanation of drawings]

Fig. 1 is an overall front view of a position accuracy confirmation device integrated with a workpiece positioning device for a laser welding device, Fig. 2 is a plan view of the position accuracy confirmation device, Fig. 3 is an enlarged view showing a receiving member, FIG. 4 is an enlarged view showing the laser deflection sensor, and FIG. 5 is an explanatory view showing the focusing of laser light by the processing head. In the figure, 1 is a positioning device, 2 is a laser welder, 3 is a head, 12 is a receiving member, and 21 is a laser deviation sensor.

Claims (2)

[Claims] (1) In the positional accuracy confirmation method of checking the positional accuracy of a workpiece positioned with the machining surface facing the processing tool head side, this method uses multiple A laser deviation sensor measures the distance to the outer surface of the back side of the workpiece at multiple locations, and compares these measured values with the reference values for each location to ensure that the deviation error at all locations is within the allowable value. A position accuracy confirmation method characterized in that the accuracy of a machining position is confirmed by (2) A positioning accuracy confirmation device that confirms the positional accuracy of a workpiece that has been positioned for machining. a plurality of laser deflection sensors disposed below the back surface of the placed workpiece; an arithmetic device that compares the actual measured value of the distance to the outer surface of the backside surface of the workpiece by the laser deflection sensor with a reference value and calculates a difference; A position accuracy confirmation device comprising a transmitting device that issues a next work command when the difference is within an allowable value in all measuring parts.