JP2001170925A - Method for fusing non-metallic material by laser - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fusing method by which even a non-metallic material such as concrete or rock can be efficiently cut or perforated. SOLUTION: The emission of a laser beam from a laser torch 11 is set at an upward angle with a concrete 14, and an assistant gas is supplied to a lser beam emitting part from a gas nozzle 13 under a pressure range of 0.25-1.0 (kg/cm2).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fusing method for cutting or piercing by irradiating a laser beam to a portion to be blown of a nonmetallic material such as concrete or rock.

[0002]

2. Description of the Related Art A method of cutting a metal plate using a laser beam is well known. On the other hand, attempts have been made to use cutting by laser light for cutting and perforating non-metallic materials such as concrete. For example, in the case of perforation, as shown in FIG. 3, a laser beam from a laser oscillator 31 is guided to a laser torch 33 by an optical fiber 32, and the laser torch 33 is provided.
Irradiation of the laser beam from the concrete 34 is performed on the concrete 34 in the horizontal direction. The reason why the laser beam is irradiated in the horizontal direction is to make it easier for molten slag generated in the molten portion of the concrete 34 to flow to the surface side of the concrete 34.

However, in the case of a material such as concrete, the slag film acts so as to hinder the penetration of the laser beam into the concrete, and as a result, the depth of the perforation is limited. This is for the following reason. In general, molten slag in materials such as concrete is composed of various oxides and has high viscosity and melting point.When cutting or drilling by irradiating laser light, the molten slag forms a molten slag film. And hinders the laser light from reaching the processing site.

[0004]

On the other hand, attempts have been made to supply an assist gas to a molten portion of concrete. For example, when cutting concrete, pressure 2 (kg / cm ² ) and 5 (kg / cm ² ) as assist gas
Attempts to cut by supplying oxygen or air have been reported, but have been reported to be ineffective.

An object of the present invention is to provide a fusing method capable of efficiently cutting and perforating even non-metallic materials such as concrete and rock, focusing again on the pressure of the assist gas.

[0006]

SUMMARY OF THE INVENTION The present invention relates to a fusing method for cutting and piercing by irradiating a laser beam to a fusible portion made of a nonmetallic material such as concrete or rock. The laser beam irradiation is performed at an upward angle including a horizontal direction, and an assist gas is supplied to the portion to be blown in a pressure range of 0.25 to 1.0 (kg / cm ² ). And

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The fusing method according to the present invention uses an assist gas of 2 (kg / kg) which has been said to be ineffective.
The laser beam is supplied at a pressure of less than ² cm ² ) to break the molten slag film which hinders the intrusion of the laser beam, so that the laser beam can reach the processing site to increase the processing capability.

FIG. 1 shows an outline of a processing apparatus when the present fusing method is used. The processing device includes a laser torch 11 for irradiating a laser beam from a laser oscillator (not shown), an assist gas supply device 12 for breaking a slag film, and a gas nozzle 13. Here, both the laser torch 11 and the gas nozzle 13 irradiate and supply the laser beam and the assist gas upward to the concrete 14. In particular, the installation position of the gas nozzle 13 is set in a distance range in which the gas flow can maintain straightness (the gas does not spread).

An important factor in the present cutting method is the reed
It is the pressure of strike gas. In previous experiments, assist
The gas is roughly gas pressure 2 (kg / cm^Two) To 8 (kg /
cm ^Two). However, in laser processing
These spraying conditions are in addition to the aforementioned slag film destruction.
The assist gas takes away the heat supplied to the laser
The effect of leaving cooling will be better, cutting or drilling
It is thought that the efficiency of has not improved.

From such a viewpoint, if the pressure of the assist gas is reduced to less than 2 (kg / cm ² ) and the cooling effect is eliminated, the slag film which hinders the penetration of the laser beam can be effectively removed, and the processing ability can be improved. Can be raised.

When the appropriate value of the assist gas pressure to be supplied is set under the condition that the drilling depth is 1.5 times the drilling depth without the assist gas as a practical effect of the assist gas, FIG. 0.25 (kg /
cm ² ) to 1.0 (kg / cm ² ). The processing efficiency can be improved by selecting the assist gas supply pressure according to the laser output within this range.

FIG. 2 shows data obtained by repeatedly performing a drilling test with a laser in which the assist gas pressure was reduced from that of the conventional method and the processing time was constant in order to establish the present fusing method. There is no effect in the range of the assist gas supply pressure of 1.5 (kg / cm ² ) or more where the gas pressure supply conditions of the conventional method are included.

The irradiation angle of the laser beam and the supply angle of the assist gas to the portion to be blown differ depending on what kind of processing is performed on the portion to be blown. For example, FIG. 1 shows a case where the concrete 14 is perforated perpendicular to its surface. In this case, the positions of the laser torch 11 and the gas nozzle 13 are fixed. On the other hand, in FIG. 1, when cutting perpendicular to the drawing is performed, the laser torch 11 and the gas nozzle 13 are moved in a direction perpendicular to the drawing while maintaining the positional relationship shown in the drawing. Alternatively, laser torch 1
1 and the gas nozzle 13 are fixed, and the concrete 14 is moved in a direction perpendicular to the drawing. On the other hand, when the oblique drilling is performed on the concrete 14, at least the laser light irradiation angle out of the laser light irradiation angle and the assist gas supply angle is also made oblique. In any case, at least the laser light irradiation angle out of the laser light irradiation angle and the assist gas supply angle is directed upward to the concrete 14 from the viewpoint of facilitating the flow of the molten slag or as shown in FIG. It must be at least horizontal.

[0014]

EXAMPLE A laser oscillator used was a YAG laser having an output of 500 (W). An oxygen gas was used as an assist gas, and a hole having a diameter of 10 mm was formed in concrete. At this time, the assist gas supply pressure was 0.5 (kg / cm ² ), and the perforation depth was at least twice as large as that without the assist gas.

The present invention is effective not only for fusing concrete, but also for non-metallic materials such as rocks and ceramics. Further, the laser oscillator is not limited to the YAG laser.

[0016]

As described above, according to the fusing method of the present invention, the efficiency of perforating and cutting a nonmetallic material such as concrete can be improved by using an assist gas at an appropriate pressure. it can.

[Brief description of the drawings]

FIG. 1 is a diagram showing a schematic configuration of a processing apparatus used for a fusing method of the present invention.

FIG. 2 is a diagram showing the results of measuring the relationship between assist gas pressure and drilling depth as test results of the fusing method of the present invention.

FIG. 3 is a diagram for explaining an attempt to use laser beam cutting for drilling a non-metallic material such as concrete.

[Explanation of symbols]

 11, 33 laser torch 12 assist gas supply device 13 gas nozzle 14, 34 concrete 32 optical fiber

Continuing from the front page (72) Inventor Takashi Kurosawa 63-30 Yuyugaoka, Hiratsuka-shi, Kanagawa F-term in Hiratsuka Works, Sumitomo Heavy Industries, Ltd. 3C069 AA01 AA04 BA08 BB03 BB04 CA01 CA07 EA01 4E068 AE01 AF01 CA08 CG01 DB00

Claims (1)

[Claims] In a fusing method for irradiating a laser beam to a cut-off portion made of a non-metallic material such as concrete or rock to perform cutting or piercing, the laser beam irradiation on the cut-off portion is performed in a horizontal direction. And an angle of upward including 0.25 to 1.0 (kg / cm ² )
A method for fusing a non-metallic material, comprising supplying an assist gas in a pressure range of: