JPH0569177A - Laser beam cutter and method for monitoring cutting speed thereof - Google Patents

Abstract

PURPOSE:To provide a laser beam cutter and method for monitoring cutting speed thereof that a speed for cutting an organic material with a laser beam can be simply and exactly detected. CONSTITUTION:A press board 4 is placed on the sample table 3. A machining head 1 with which the laser beam 2 is emitted is arranged so that it can scan the plane of the press board 4 which is cut into a prescribed shape by radiating the laser beam 2 on it. Exhaust hoods 5 are arranged in the vicinity of the machining head 1 and inflammable gas which is generated from the press board 4 when cutting is exhausted. The exhaust hoods 5 are communicated to the outdoor 8 with exhaust ducts 7. In the path of the exhaust ducts 7, a gas sensor 11 with which inflammable gas is detected is arranged.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laser cutting device and a cutting speed monitoring method for cutting an organic material with a good finish.

[0002]

2. Description of the Related Art FIG. 5 is a block diagram showing an example of a conventional laser cutting apparatus. In the figure, reference numeral 1 is a processing head for emitting a laser beam 2, and the processing head 1 is arranged so that it can be scanned in a plane. It is set up. 3 is a press board made of organic material, for example, cellulose fiber such as cloth or paper 4
A sample table 5 on which the above is placed is an exhaust hood for exhausting combustible gas generated from the press board 4 during laser cutting,
Reference numeral 6 is a water tank, and 7 is an exhaust duct that connects the exhaust hood 5 to the outside 8, and the exhaust hood 5 and the exhaust duct 7 form an exhaust system for combustible gas. 9 is a dust collecting filter provided in the path of the exhaust duct 7, 10 is an assist gas in the laser cutting part of the press board 4 at the time of laser cutting,
For example, it is an assist gas jet that blows air.

Next, the operation of the conventional laser cutting device will be described. First, the press board 4 is placed on the sample table 3, and scanning conditions such as scanning coordinates and scanning speed of the processing head 1 are set in a control unit (not shown) so that the press board 4 can be cut into a desired shape. Then, the processing head 1 is scanned based on the set scanning conditions, the laser beam 2 is irradiated, and the laser cutting of the press board 4 is performed. At this time, flammable gas is generated from the laser cutting portion of the press board 4. This combustible gas is the assist gas jet 1
The air blown from 0 causes the air to flow into the exhaust hood 5, and is exhausted to the outside 8 via the exhaust duct 7 and the dust collecting filter 9. Here, heavy dust is captured in the water tank 6.

As described above, in the conventional laser cutting apparatus, the scanning conditions are set in advance, the processing head 1 is scanned based on the set scanning conditions, and the press board 4 is simply cut into a desired shape. Moreover, in the case of a straight line or a simple shape, it is possible to cut at high speed and with a good finish.

[0005]

As described above, since the conventional laser cutting apparatus scans the press board 4 by scanning the working head 1 based on the preset scanning conditions, it is possible to cut a curved line or a curved line. In the case of a complicated cutting shape, it becomes difficult to perform laser cutting at an optimum cutting speed suitable for the cutting shape, and there is a problem that carbide adheres to the cutting surface and the quality as a product is impaired.

The present invention has been made to solve the above problems, and an object thereof is to obtain a laser cutting device capable of detecting a cutting speed, and a cutting speed monitoring method capable of monitoring the cutting speed. The purpose is to provide.

[0007]

A laser cutting apparatus according to the present invention is provided with a gas sensor for detecting a combustible gas generated in the laser cutting of an organic material, in a path of an exhaust system of the combustible gas.

Further, in the cutting speed monitoring method of the laser cutting apparatus according to the present invention, the organic material placed on the sample table is irradiated with a laser beam to laser-cut the organic material while laser-cutting the organic material. The combustible gas generated at this time is detected by a gas sensor, and the laser cutting speed is monitored from the output value of the gas sensor.

[0009]

In the present invention, since the gas sensor detects the amount of combustible gas generated from the cut portion of the organic material in correlation with the cutting speed, the cutting speed can be detected from the output value of the gas sensor.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a configuration diagram showing an embodiment of a laser cutting device of the present invention. In the figure, the same or corresponding parts as those of the conventional laser cutting device shown in FIG. .. In the figure, 11 is a gas sensor provided in the path of the exhaust duct 7 for detecting a combustible gas.

Next, the operation of the embodiment of the present invention shown in FIG. 1 will be described. The combustible gas generated from the cut portion of the press board 4 flows into the exhaust hood 4 and the exhaust duct 7 together with the air ejected from the assist gas ejection port 10, and is detected by the gas sensor 11.

The other operations are the same as those of the conventional laser cutting device shown in FIG.

The relationship between the amount of flammable gas generated from the cutting portion of the pressboard 4 and the cutting speed will be described. 2A to 2C are gas chromatograms showing the relationship between the cutting speed and the amount of combustible gas generated, and insulating paper is used as the press board 4. As shown in A (hatched portion) of (a) to (c) of FIG. 2, the peak area of the flammable gas increases as the cutting speed increases.
That is, it can be seen that the amount of flammable gas generated increases. When the type and thickness of the insulating paper as the press board 4 are different, the peak area of the flammable gas changes, but the peak area of the flammable gas tends to increase as the cutting speed increases. Have

FIG. 3 is a graph showing the relationship between the cutting speed and the peak area of the flammable gas in the gas chromatogram and the output value of the gas sensor. FIG. 4 is the peak area ratio of the flammable gas to CO ₂ in the cutting speed and the gas chromatogram. It is a graph which shows the relationship with. From FIGS. 3 and 4, the peak area of the flammable gas or the peak area ratio of the flammable gas and CO ₂ in the gas chromatogram shows a relationship proportional to the cutting speed, and the output value of the gas sensor 11 is also cut. The relationship is proportional to the speed.

That is, the amount of combustible gas proportional to the cutting speed is generated from the cutting portion of the press board 4, and the output value of the gas sensor 11 that detects this amount of combustible gas indicates the cutting speed. Will be there.

Now, a cutting speed monitoring method for the laser cutting apparatus of the present invention shown in FIG. 1 will be described. The gas sensor 11 detects a combustible gas flowing through the exhaust hood 5 and the exhaust duct 7 while irradiating the press board 4 mounted on the sample table 3 with a laser beam to perform laser cutting, and the output value of the gas sensor 11 is detected. The cutting speed is monitored based on.

As described above, according to the present invention, since the gas sensor 11 is provided in the path of the exhaust system of the combustible gas, the same material as the press board 4 to be cut is used, and the cutting speed and the gas sensor 11 are set in advance. If the relationship with the output value is measured, the gas sensor 11 corresponding to the combustible gas amount
Can be obtained, and the actual cutting speed can be monitored from the output value of the gas sensor 11 based on the relationship between the cutting speed and the output value of the gas sensor 11 which has been measured in advance.

Further, the relationship between the cutting speed measured in advance and the output value of the gas sensor 11 is input to the control unit, and the output value of the gas sensor 11 during the cutting operation is fed back to the control unit to scan the machining head 1. By correcting the speed, even when cutting into a curved or complex shape, the optimum cutting speed that matches the cutting shape is automatically selected, and a product with good finish can be easily obtained. Work can be automated.

[0019]

Since the present invention is constructed as described above, it has the following effects.

Since the laser cutting device according to the present invention is provided with the gas sensor in the path of the exhaust system for the combustible gas,
The laser cutting speed can be easily detected based on the output value of the gas sensor.

In the cutting speed monitoring method of the laser cutting apparatus according to the present invention, the flammable gas generated at the time of cutting is detected by the gas sensor, and the cutting speed is monitored based on the output value of this gas sensor. The cutting speed can be easily and accurately monitored without the need for.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an embodiment of a laser cutting device of the present invention.

2 (a) to 2 (c) are gas chromatograms showing the relationship between the cutting speed and the amount of combustible gas generated in the present invention.

FIG. 3 is a graph showing the relationship between the cutting speed, the peak area of combustible gas in the gas chromatogram, and the output value of the gas sensor in the present invention.

FIG. 4 is a graph showing the relationship between the cutting rate and the peak area ratio of flammable gas and CO ₂ in a gas chromatogram in the present invention.

FIG. 5 is a configuration diagram showing an example of a conventional laser cutting device.

[Explanation of symbols]

 1 Processing Head 2 Laser Beam 3 Sample Table 4 Press Board (Organic Material) 5 Exhaust Hood (Exhaust System) 7 Exhaust Duct (Exhaust System) 11 Gas Sensor

Claims (2)

[Claims] 1. A laser cutting device comprising a sample table on which an organic material is placed, a processing head for emitting a laser beam, and an exhaust system for exhausting a flammable gas generated during laser cutting of the organic material, A laser cutting device, wherein a gas sensor for detecting the flammable gas is provided in a path of the exhaust system. 2. A gas sensor detects a flammable gas generated when the organic material is laser-cut while irradiating the organic material placed on the sample table with a laser beam to laser-cut the organic material. A method for monitoring a cutting speed of a laser cutting device, wherein the laser cutting speed is monitored from an output value of the gas sensor.