JPH035093A - Laser beam machine - Google Patents

Abstract

PURPOSE:To control a focal position of laser beams with higher precision by interposing an insulation treating part between the outer circumference of the attached end part of the nozzle of a laser beam machine and the outer circumference of the attached end part of the laser beam machine body. CONSTITUTION:As an insulation treating part of the laser beam machine, an insulating layer 11 for the outer circumference of a flange and an insulating layer 12 for the outer circumference part are provided respectively on the circumferential surface of the flange 6h of the upper part of a 2nd electrode 6c forming a nozzle and between the lower surface of the outer circumferential part of an insulation plate 3 opposing the flange 6h on the outer circumferential side of an electrode fixing plate 6e and a flange 6b. Both these insulating layers 11, 12 are interposed between the 2nd electrode 6c and the insulating plate 3 and dust and moisture are prevented from coming in because the clearance between a nozzle and a lens holder 1 of the laser beam machine body is choked and electrical short circuit between them is avoided. In this way, the electric capacity is detected accurately and the focal distance of the laser beam can be controlled automatically.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a laser processing machine that processes a workpiece by condensing laser light emitted from a laser oscillator with a condensing lens and irradiating it from the tip of a nozzle. More specifically, the present invention relates to a laser processing machine having an electrode for detecting the distance between a nozzle tip and a workpiece by measuring electromagnetic capacitance, such as eddy current, magnetism, electrostatic capacitance, etc.

[Conventional technology]

FIG. 2 shows, for example, a conventional laser processing machine, and in the figure, reference numeral 1 denotes a lens holder attached to the main body of the laser processing machine, which holds a condenser lens 2 inside. 6 is the nozzle,
This is fixed to the lens holder 1 via an insulating plate 3 and an insulating sleeve 4 with mounting bolts 5.

Further, the nozzle 6 has a hollow conical shape, and an injection port 6f through which laser light, assist gas, etc. pass is formed at the tip, that is, at the center of the lower end.

The nozzle 6 is interposed between an inner first electrode 6a, a ring-shaped second electrode 6c surrounding the first electrode 6a, and the picture electrodes 6a and 6c to insulate them from each other. It consists of an insulating layer 6b. 6e is an electrode fixing plate that fixes the first electrode 6a to the second electrode 6C via the insulating member 6d. 7 is a connector screwed onto the threaded portion 6g provided on the first and second electrodes 6c; 8 is a coaxial cable connected to this connector 7;
a is the first electric wire that becomes the core wire of the coaxial cable 8;
It is connected to the electrode 6a.

Reference numeral 8b denotes a second electric wire disposed insulatively outside the first electric wire 8a, and this is connected to the second electrode 6c via the connector 7. 9 is a capacitance detector connected to the first electric wire 8a and the second electric wire 8b, and 10 is a workpiece to be laser-processed.

Next, the operation will be explained. First, when laser processing the workpiece 10, laser light is focused by the condensing lens 2 and irradiated onto the workpiece 10 from the end of the nozzle 6, and assist gas is injected from the injection port 6f to the processing area. In this case, in order to maintain the machining accuracy of the workpiece 10, it is important to keep the focal position of the laser beam constant, but as the machining progresses, the focal position gradually shifts. In other words, the gap between the nozzle 6 and the workpiece 10 changes.

Therefore, this change in the gap is interpreted as a change in capacitance between the first electrode 6a, the second electrode 6c, and the workpiece 1o, and based on this change, the position of the laser processing machine main body is controlled by a control device (not shown). The above gap is automatically controlled to be a constant value. The second electrode 6c covers the outer periphery of the nozzle 6, and is electrically and structurally connected to the lens holder 1 of the main body of the laser processing machine to which the nozzle 6 is attached via the insulating plate 3 and the insulating sleeve 4. The nozzle 6 is directly opposed to the main body of the laser processing machine and the nozzle 6 is kept insulated from the main body.

[Problem to be solved by the invention]

Since the conventional laser processing machine is configured as described above, the lens holder 1 and the nozzle 6 directly face each other and have a small creepage distance, so in a humid environment or a place with a lot of dust, the dust or water droplets etc. on the lens holder 1.
This causes the nozzle 6 to be electrically short-circuited, resulting in problems such as the capacitance and the like cannot be detected with high accuracy.

This invention was made to solve the above-mentioned problems, and it prevents short circuits between the lens holder and nozzle of a laser processing machine, and stably controls the accurate focal point position of the laser beam. The object of the present invention is to obtain a laser processing machine that can detect capacitance and the like with high precision.

[Means to solve the problem]

A laser processing machine according to the present invention includes: an outer periphery of a mounting end of a nozzle having a first electrode and a second electrode for detecting electromagnetic capacitance;
An insulating treatment section such as an insulating layer is interposed between the nozzle and the outer periphery of the attachment end of the main body of the laser processing machine to which the nozzle is attached.

[Effect]

The insulation treatment part in this invention insulates and closes the space between the outer periphery of the mounting end of the nozzle and the outer periphery of the mounting end of the laser processing machine main body, thereby preventing dust and moisture from entering between them, and also preventing creepage. By making the distance large, electrical short circuit between the two can be prevented, and the focal position of the laser beam can be controlled with high precision by electromagnetic capacitance detection.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings. 1st
In the figure, reference numeral 11 denotes a flange outer circumferential insulating layer as an insulating treatment section, which is provided on the circumferential surface of the flange 6h above the second electrode 6c forming the nozzle 6. Reference numeral 12 denotes an outer peripheral insulating layer as an insulation treatment section, which is provided on the outer peripheral side of the electrode fixing plate 6e and between the lower surface of the outer peripheral surface of the insulating plate 3 facing the flange 6h and the flange 6h. Therefore, each of these insulating layers 11, 12 increases the electrical creepage distance between the second electrode 6c and the lens holder, and prevents dust from entering and adhering to the lens holder. Note that other components that are the same as those shown in FIG. 2 are designated by the same reference numerals, and redundant explanation thereof will be omitted.

Also, insulating plate 3. Insulating sleeve 4. Insulating layer 6b.

Insulating member 6d, flange outer peripheral insulating layer 11. The outer peripheral insulating layer 12 may be, for example, a ceramic sprayed layer.

Next, the operation will be explained. The flange outer circumferential insulating layer 11 and the outer circumferential insulating layer 12 are interposed between the second electrode 6c and the insulating plate 3, respectively, and close the gap between the nozzle 6 and the lens holder 1 of the laser processing machine main body. . Therefore, the creepage distance between the nozzle 6 and the vicinity of each outer periphery of the lens holder 1 becomes longer, and it is possible to prevent dust and moisture from entering between the nozzle 6 and the laser processing machine main body. Electrical short circuits can be avoided. Therefore, it is possible to accurately detect the electromagnetic capacitance and automatically control the focal position (distance) of the laser beam to a desired constant value.

Note that although ceramic is used as the insulating material in the above embodiment, other insulating materials may be used.

Further, in the above embodiment, the electrostatic capacitance as electromagnetic capacitance is detected, but it is also possible to detect the strength of eddy current and magnetism, and the same effects as in the above embodiment can be obtained.

〔Effect of the invention〕

As described above, according to the present invention, there is a gap between the outer periphery of the mounting end of the nozzle having the first and second electrodes for detecting electromagnetic capacitance and the outer periphery of the mounting end of the main body of the laser processing machine to which this nozzle is attached. Since the structure is such that an insulation treatment section is provided on the
The creepage distance between the respective outer circumferences can be increased, and therefore the gap between the nozzle and the workpiece 10 can be optimally controlled to a constant value by highly accurate detection of electromagnetic capacitance.

[Brief explanation of drawings]

FIG. 1 is a vertical cross-sectional view of a main part of a laser beam machine according to an embodiment of the present invention, and FIG. 2 is a partial vertical cross-sectional view of a conventional laser beam machine. 6 is a nozzle, 6a is a first electrode, 6C is a second electrode, 10 is a workpiece, and 11.12 is an insulation processing section. In addition, in the figures, the same reference numerals indicate the same or equivalent parts.

Claims (1)

[Claims] In a laser processing machine that moves and adjusts the nozzle by detecting the electromagnetic capacitance between the nozzle tip and the workpiece so that the distance between the two is always kept constant, an electromagnetic capacitor that detects the electromagnetic capacitance is used. a first electrode connected to the capacitance detector, a second electrode electrically insulated from the first electrode and connected to the electromagnetic capacitance detector, and a second electrode connected to the electromagnetic capacitance detector; A laser processing machine characterized by comprising: an insulation treatment section that insulates the outer periphery of the mounting end of the nozzle and the outer periphery of the mounting end of the laser processing machine main body to which the nozzle is mounted.