JPH0199792A - Laser beam machine - Google Patents

Abstract

PURPOSE:To monitor the stained state of an optical element and to control the performance of the optical element by providing the light projector radiating a light on the face of the work side of the optical element radiating by condensing a laser light and the light receiver measuring the light amt. of the reflection light of this light. CONSTITUTION:When a work 4 is worked by a laser light 2, the generated spatter 7 is ascended inside a nozzle 3C and sticked on the face 3d of the work side of a working lens 3a. Now, when the power source 10 of a projector 8 is inputted, the light of a fixed light amt. from a projector 8 is reflected by the surface of a work lens 3a, incident on a light receiver 9 and the light amt. of the light is displayed by a display meter 11. At this time, the light amt. displayed by the meter 11 is reduced so much as the sticking amt. of the spatter 7 is larger. Therefore when the light amt. becomes less than a reference value it becomes judgeable to need the cleaning or change of the work lens 3a.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a laser processing machine that processes a workpiece with a laser beam.

[Prior Art] FIG. 2 is a configuration diagram showing an example of a laser processing machine. In the figure, (1) is a laser oscillator that generates laser light;
(2) is the laser beam emitted from the laser oscillator (1), (
2a) is a reflecting mirror that reflects the laser beam (2) in the right angle direction, and (3) is a processing head that constitutes an optical system that focuses the laser beam (2) and irradiates it onto the workpiece. (4) is the workpiece, and (5) is the horizontal plane X-Y with the workpiece (4) placed on it.
The X-Y table (6) that moves in the axial direction moves the X-Y table (5) and aligns the workpiece (4) with the laser beam (
2) is an NC that controls the relative positional relationship.

FIG. 3 is an enlarged longitudinal sectional view of a conventional processing head (3). (3a) is an optical element (processing lens) that focuses the laser beam (2>), (3b) is a lens holder for the processing lens (3a), and when the laser beam (2) passes through the processing lens (3a), The processing lens (3a) is cooled with cooling water (30) in order to absorb the generated thermal energy and prevent thermal damage to the processing lens (3a). It is a nozzle. Note that (7) is spatter generated when laser processing the workpiece (4).

Next, the operation will be explained. Laser light (2) generated by a laser oscillator (1) is introduced into a processing lens (3a) of a processing head (3), focused, and irradiated onto a workpiece (4). At this time, the processing lens (3a) is exposed to the laser beam (2).
The lens holder (3b) is heated by the thermal energy generated when the lens passes through the lens holder (3b), but is cooled by the cooling water (30).
Since the processed lens (3a) is indirectly cooled, thermal damage to the processed lens (3a) is prevented. On the other hand, the NC (6) drives and controls the x-y table (5) in the X-Y axis direction, and moves the workpiece (4) placed on the X-Y table (5) to a desired position. and change the irradiation position on the surface of the workpiece (4) to which the laser beam (2) is irradiated. The energy density of the laser beam (2) irradiated onto the workpiece (4) is
) is very large as 10 −10 w/(1)2,
Therefore, the workpiece (4) irradiated with the laser beam (2) is melted and vaporized, and thermally processed into a desired shape.

[Problems to be Solved by the Invention] According to the conventional laser processing machine configured as described above, spatter (a) is generated when the workpiece (4) is thermally processed, and some of it is emitted from the nozzle ( 3c) rises in the direction of the arrow and attaches to the workpiece side surface (3d) of the processing lens (3a). Therefore, when the laser beam (2) passes through the processing lens (3a), the thermal energy generated in the processing lens (3a) increases, causing deformation of the processing lens (3a) and optical distortion due to uneven temperature distribution. to occur. Therefore, the focal position of the processing lens (3a), the beam condensing diameter, etc. change, making it impossible to process the workpiece (4). For this reason, the processed lens (3a) must be cleaned regularly or replaced in some cases, but the timing of cleaning and replacement changes depending on conditions such as the work environment and frequency of use, so it is difficult to determine the timing. there were.

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a laser processing machine that can clearly determine when to clean and replace a processed lens.

[Means for solving the problems] The present invention has been made to achieve the above objects, and
To provide a laser processing machine that is provided with a projector that is close to an optical element that condenses laser light and irradiates light onto a surface of the optical element on the workpiece side, and a light receiver that determines the amount of reflected light. It is something.

[Operation When spatter adheres to the workpiece side surface of the optical element that condenses the co-laser light, the amount of reflected light changes depending on the amount of adhesion. It is determined based on the output of the light receiver when the amount of reflected light falls below a certain reference value, and the optical element is cleaned or replaced.

[Embodiments of the invention] FIG. 1 is a longitudinal sectional view showing an embodiment of the present invention.

Note that parts having the same functions as those in FIG. 3 are denoted by the same symbols, and explanations thereof will be omitted. (8) is a light projector that irradiates light from an oblique direction onto the workpiece side surface (3d) of the processing lens (3a);
9) is a light receiver that receives the amount of light reflected from the processing lens (3a) and generates an electric signal according to the amount of light; (10)
is a power source for the light projector (8), and (11) is a display meter that displays the electrical signal generated by the light receiver (9).

A detailed explanation of the present invention configured as above is as follows. The principle of laser processing is shown in Figure 2.
Since this is the same as the case shown in FIG. 3, the explanation will be omitted. When the workpiece (4) is processed by the laser beam (2), the spatter (7) generated by the processing rises inside the nozzle (3a) in the direction of the arrow, and the surface of the processing lens (3a) on the workpiece side ( 3d). Now, turn on the power source (10) for the floodlight (8).
), a constant amount of light is irradiated from the projector (8) onto the workpiece side surface (3d) of the processing lens (3a).

This light is reflected by the surface of the processing lens (3a) and enters the light receiver (9). In this way, the amount of light incident on the light receiver (9) is displayed on the display meter (11). In this case, since the spatter (7) generated during laser processing is attached to the workpiece side surface (3d) of the processing lens (3a), the larger the value of the spatter (7), the more the display meter ( 11) The amount of light displayed decreases. In other words, when the amount of displayed light falls below a certain standard value,
It becomes possible to determine that the processed lens (3a) needs to be cleaned or replaced.

In the above description, a processed lens is used as an optical element for condensing laser light, but any optical element that functions similarly may be used. In addition, in the above explanation, we have described the case where the amount of light is displayed using a display meter to determine when it is time to clean or replace the light. Alternatively, a signal such as an alarm may be generated to determine when it is time for cleaning or replacement.

[Effects of the Invention] As is clear from the above description, according to the present invention, it is possible to monitor the dirtiness of the optical element that focuses the laser beam of the laser processing head, so the performance of the optical element can be controlled under certain conditions. This has the effect of providing a high-performance laser processing machine.

[Brief explanation of the drawing]

FIG. 1 is a vertical cross-sectional view of a main part of an embodiment of the present invention, FIG. 2 is a configuration diagram of a laser processing machine, and FIG. 3 is an enlarged vertical cross-sectional view showing an example of a conventional processing head. (1)...Laser oscillator, (2)...Laser light, (
3)...Processing head, (3a)...Processing lens, (
3b)...Lens holder, (3c)...Nozzle,
(3d)...Workpiece side surface, (4)...Workpiece, (5)...X-Y table, (6)...NC, (
7)... Spatter, (8)... Floodlight, (9)...
- Light receiver, (10)...power supply, (11)...display meter. Note that the same reference numerals in the figures indicate the same or corresponding parts.

Claims (1)

[Scope of Claims] A laser oscillator that generates laser light, an optical element that focuses the laser light and irradiates it onto a workpiece, and controls the relative positional relationship between the workpiece and the focused laser light. A laser processing machine comprising: a light projector that is close to the optical element and irradiates a workpiece-side surface of the optical element with light; and a light receiver that measures the amount of reflected light of this light. A laser processing machine characterized by being provided with.