JPH0257000B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a three-dimensional laser processing machine, and particularly to a three-dimensional laser processing machine that performs laser processing such as cutting and welding on a workpiece having a three-dimensional surface. It is something.

[Prior Art] FIG. 4 is a block diagram showing the system configuration of a conventional three-dimensional laser processing machine. In the figure, 1
2 is a laser oscillator, 2 is a five-axis laser optical path system oscillated by the oscillator 1, 3 is a control device for controlling the laser optical path, 4 is a laser processing head, 5 is a workpiece having a three-dimensional free-form surface, and 6 is a workpiece having a three-dimensional free-form surface. This is a console that operates or teaches the processing system.

A conventional three-dimensional laser processing machine is configured as described above, and when performing laser processing, the laser processing head 4 is adjusted to the height from the workpiece 5 and the attitude relative to the workpiece 5 (the optical axis of the projected laser beam and the workpiece). Move the workpiece so that the angle between the workpiece and the surface of the workpiece remains within a certain range.
Therefore, before laser processing, the operator must
The start and end points of the machining trajectory are taught while manually moving the optical axis by operating the , during which time the machining trajectory is programmed using interpolated data.

In addition, in order to prevent erroneous irradiation of the processing laser beam, Japanese Patent Publication No. 59-52036 provides a distance measuring device that measures the distance between the laser irradiation end and the target object, and the distance measuring device is used as the aiming light. A configuration is shown in which a directional photodetector is installed at a certain angle of inclination to the visible laser beam.

However, the method in this publication is intended to prevent erroneous irradiation of the processing laser beam when used as a laser scalpel, and does not automatically teach the processing trajectory according to the distance to the object. This automatically controls ON/OFF of the irradiation of laser light for processing.

[Problems to be solved by the invention] In the conventional three-dimensional laser processing machine as described above,
When programming the machining trajectory, the operator determines and teaches the position and orientation (angle) of the laser processing head relative to the three-dimensional free-form surface of the workpiece by eye, resulting in failure in teaching point selection or teaching point selection. There were problems such as it taking too much time to set up.

The present invention has been made to solve these problems, and provides a three-dimensional laser processing machine that can perform teaching work easily and accurately in a short time, and can also control the optical axis or measure three-dimensional coordinates. The purpose is to obtain.

[Means for Solving the Problems] A three-dimensional laser processing machine according to the present invention is a three-dimensional laser processing machine that processes a workpiece having a three-dimensional surface. A laser processing head that projects onto the surface of an object, a light source that projects a measurement laser beam onto the surface of the workpiece that is coaxial with the processing laser beam and has a different wavelength from the processing laser beam, and a light source that projects the measurement laser beam onto the workpiece surface. The amount of reflected light received depends on the distance between the laser processing head and the surface of the workpiece, the angle between the optical axis of the projected laser beam and the surface of the workpiece, and the material and color conditions of the workpiece. a light receiver that receives changing input; a circuit that calculates the distance between the laser processing head and the surface of the workpiece from changes in the amount of received light based on a certain calculation formula; and a display device that displays the calculation results. The configuration includes a circuit that compares the value calculated by the above circuit with a reference value and changes the output amount of the light source so that the amount of received light becomes a constant value, and a display means that displays the changed value of this circuit. It is something.

[Function] In the three-dimensional laser processing machine of the present invention, when the measurement laser beam projected from the light source is reflected by the surface to be measured and received by the light receiver, the contact between the laser processing head and the surface to be measured is It is calculated based on the signal from the receiver, taking into account that the amount of light received changes depending on the distance, the angle between the optical axis of the projected laser beam and the surface to be measured, and the material and color conditions of the workpiece. By displaying the distance between the laser processing head and the measured surface, and displaying the output amount of the light source that is changed to keep the amount of received light constant, the angle of the laser processing head can be determined from the output amount of the light source.・Know the conditions of the workpiece, and based on this knowledge, you will be able to operate and teach the three-dimensional laser processing machine.

[Example] FIG. 1 is a block diagram showing an example of the present invention.
FIG. 2 is a block diagram showing the optical sensor system of FIG. 1. In Figures 1 and 2, 1~
3, 5, and 6 are the same as the conventional device.

4 is a half mirror 21 in the internal light projection optical path system 15.
is provided with a laser processing head that projects a processing laser beam D (indicated by a broken line) of a predetermined wavelength onto the surface of the workpiece 5; 7 is an optical sensor provided on the laser processing head 4, and is connected to a light source 13 to be described later. It is composed of a light receiver 14. Reference numeral 13 denotes a light source composed of a semiconductor laser oscillator, which projects a measuring laser beam B (indicated by a solid line) having a wavelength different from that of the processing laser beam D onto the surface of the workpiece 5, and also directs the projection optical axis. The system 15 is configured to project the beam coaxially with the processing laser beam D. 14 is a PSD (Position) that receives part C of the light scattered from the surface of the workpiece 5.
This is a light receiver equipped with a light receiving element such as a sensitive device (semiconductor position detection sensor), and is configured to match the wavelength of the measurement laser beam B. 16 is a circuit that processes the signal from the light receiver 14 and calculates the distance between the laser processing head 4 and the surface of the workpiece 5;
17 is a circuit that calculates the amount of light received by the light receiver 14 based on a certain calculation formula and changes the output amount of the light source 13; 18 is a distance data output line; and 20 is an output of the output amount of the light source 13. line, 2
2 is an amplifier; 8 is a display device that outputs the distance information calculated by the circuit 16; and 9 is a display device that displays the output amount of the light source 13 calculated by the circuit 17. Note that a lens is provided in front of the light receiver 14, but is not shown.

The above-mentioned optical sensor 7 is also generally called an optical displacement meter, and has two power supplies (not shown) that supply power for light detection to the light receiver 14, and the power flows from one of these two power supplies. When the current is I _A and the current flowing from the other side is I _B , the structure is such that I _A + I _B is proportional to the amount of light received. Such optical sensors and distance measurement methods are known, for example, from the Japanese Patent Publication No. 56-10561.
Since it is described in the above publication, it will be briefly explained here.

In the three-dimensional laser processing machine configured as described above, when the laser beam from the light source 13 is projected onto the three-dimensional surface of the workpiece 5 shown by diagonal lines in FIG. 3) varies depending on the distance between the laser processing head 4 and the surface to be measured and the angle of the laser processing head 4. That is, the light receiving position (center of gravity position) in the light receiver 14 corresponds to the distance between the laser processing head 4 and the measuring surface. Therefore, receiver 1
4 receives the reflected light, converts it into two currents I _A and I _B and takes them out. The circuit 16 receives the input currents I _A and I _B
The calculation based on the following equation is performed.

l=I _A −I _B /I _A +I _B (1) Note that l corresponds to the displacement of the laser processing head. This calculated displacement l is displayed on the distance display device 8.

Note that the amount of light received by the light receiver 14 is inversely proportional to the distance between the processing head 4 and the surface to be measured. Also,
The amount of light received is affected by the material and color of the surface to be measured and the attitude (angle) of the processing head 4, but by dividing the numerator by the denominator "I _A + I _B " in equation (1),
The accuracy of the distance value decreases as the amount of received light decreases. Therefore, control is performed to keep the amount of light received constant.

Next, the added current I _A +I _B is input to the circuit 17, and calculation based on the following equation is performed.

I _LD = (I _s - K)・F...(2) In addition, I _s = I _A + I _B F = transfer function K = reference value The reference value K is the surface of the workpiece 5 measured by the optical sensor 7. This is set based on the amount of light received when the distance, the material and color of the workpiece, and the attitude (angle) of the laser processing head 4 are constant.
Therefore, if the calculated value I _LD is close to 0 value,
The distance and posture (angle) of the laser processing head 4 and the surface conditions of the workpiece 5 are the same as the setting conditions of the reference value K. Here, if _ILD deviates from the 0 value, this means that the material and color of the surface to be measured, the attitude of the laser processing head 4, and the distance from the surface to be measured have changed from the reference values. Therefore, in order to keep I _LD within a certain range, the output amount (emission amount) of the light source 13 is controlled so that the amount of light received by the photoreceiver 14 is constant, and the light source is adjusted to correspond to the change in I _LD . The output amount is displayed on the output display device 9. For example, when the attitude (angle) of the laser processing head 4 with respect to the free-form surface of the workpiece 5 changes and the amount of light received by the light receiver 14 decreases, the output amount is controlled by the circuit 17 to increase so that the amount of light received is constant. That will happen. Therefore, the output amount indicates the state (material, color, etc.) of the three-dimensional surface of the workpiece 5 and the attitude (angle) of the laser processing head 4 with respect to the surface to be measured.

The operator sees the output amount of the light source 13 displayed in real time, learns information related to the above conditions, and based on this, teaches and operates the three-dimensional laser processing machine (moves the laser processing head).
etc. can be done.

For example, since the change in distance is determined by equation (1), the remaining change conditions are the material and color of the workpiece, and the attitude (angle) of the machining head. It can be assumed that the color does not change, so
The only remaining condition is the attitude of the processing head.

Therefore, the angle of the processing head 4 with respect to the surface to be measured is controlled so that the laser beam is perpendicular to the surface.
If the teaching operation or the like is performed, the machining accuracy will be improved.

In a three-dimensional laser processing machine, it is very time-consuming to perform teaching operations to keep the laser processing head perpendicular to the surface of the workpiece, but if you do as in the above example, information on the posture of the processing head can be obtained. is displayed, making the teaching operation easier.
Therefore, the speed of the teaching operation will be improved.

[Effects of the Invention] Since the present invention is configured as described above, information regarding the distance between the laser processing head and the surface of the workpiece, the attitude (angle) of the laser processing head, and the conditions of the material and color of the workpiece can be obtained. , displayed in real time,
Based on this display, the operator can operate the laser optical axis, etc., and has the effect of enabling the operator to easily and accurately perform teaching work in a short time.

In addition, by controlling the optical axis by feeding back distance information and orientation information, it is possible to perform continuous tracking processing while measuring the three-dimensional coordinates of the workpiece or correcting the position and orientation of the processing head. .

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing one embodiment of the present invention;
Figure 2 is a block diagram showing the optical sensor system in Figure 1, Figure 3 is an explanatory diagram showing the distribution of reflected light from the surface of the workpiece, and Figure 4 is the system of a conventional three-dimensional laser processing machine. FIG. DESCRIPTION OF SYMBOLS 1... Laser oscillator, 2... Laser optical path system, 3... Optical axis control device, 4... Laser processing head, 5... Workpiece, 6... Operation console, 7... Optical sensor, 8... Distance display device, 9... Light source Output amount display device, 13... light source,
14... Light receiver, 15... Light emitting optical path system, 16... Distance calculation circuit, 17... Output amount calculation circuit. In each figure, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Scope of Claims] 1. A three-dimensional laser processing machine that processes a workpiece having a three-dimensional surface, comprising: a laser processing head that projects processing laser light of a predetermined wave number onto the surface of the workpiece; A light source that projects a measuring laser beam coaxial with the laser beam and having a wavelength different from that of the processing laser beam onto the surface of the workpiece; a light receiver into which the amount of reflected light received changes depending on the distance from the surface, the angle between the optical axis of the projected laser beam and the surface of the workpiece, and the material and color conditions of the workpiece; A circuit that calculates the distance between the laser processing head and the surface of the workpiece from changes in the amount of received light based on a certain calculation formula, a display device that displays the calculation results, and a reference to the value calculated by the circuit. A three-dimensional laser processing machine comprising: a circuit that changes the output amount of the light source so that the received light amount becomes a constant value when compared with a value; and a display means that displays the changed value of this circuit. .