JPS60145272A - Gas cutting method - Google Patents

Abstract

PURPOSE:To perform stably gas cutting without clogging of a cutting nozzle owing to molten iron oxide by approaching the cutting nozzle to a steel plate to be cut and rising the nozzle while moving slowly forward the nozzle simultaneously with the outflow of high-pressure oxygen. CONSTITUTION:A cutting nozzle 1 is risen by about 10-30mm. and is moved in a cutting direction at a speed of about 70% of the normal cutting speed to prevent sticking of molten iron oxide to the end of the nozzle 1 while the nozzle 1 is moved simultaneously with outflow of high-pressure oxygen in a gas cutting method consisting in injecting a mixed flame composed of a combustible gas and oxygen from the nozzle 1 to heat a steel plate 2 to the combustion temp. then injecting the high-pressure oxygen from the nozzle 1 to the surface of the steel plate 2, melting the surface of the steel plate by the heat of chemical reaction of iron and oxygen and removing the same by the high-pressure oxygen. The nozzle 1 is lowered to a normal height after the nozzle is risen by a specified distance then an ordinary cutting operation is started.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a so-called piercing operation in which a steel plate surface is heated with a mixed flame of combustible gas and oxygen during gas cutting, and then holes are made using high pressure oxygen.

[Prior art]

Conventional working methods of this type include those shown in FIGS. 1 and 2. In FIG. 1, (1) is a cutting crater through which gases are injected, and (2) is a steel plate to be cut. Figure 2 is a diagram showing the movement of the cutting crater.

Next, the operation will be explained. High-pressure oxygen is injected from the cutting nozzle (1) onto the surface of the steel plate (2), which has been heated to combustion temperature by the mixed flame of flammable gas and oxygen injected from the cutting nozzle +11, and the chemical reaction heat between iron and oxygen is generated. This causes melt ridges to form on the surface of the steel plate, and the molten iron is removed by the energy of the high-pressure oxygen jet. If the cutting crater (1) is not moved for a certain period of time, the chemical reaction described above will proceed in the thickness direction of the steel plate, and combined with the jet energy of high-pressure oxygen, a hole will be created in the steel plate directly in the crater.

The conventional work method was carried out as described above, so when the molten iron oxide was scattered and removed by the jet energy of high-pressure oxygen,
It hits the tip of the cutting nozzle and blocks the opening through which the gas flows, making it impossible to perform piercing without the gas leaking out, and there are drawbacks such as the need to clean the cutting nozzle each time.

[Summary of the invention]

This invention was made in order to eliminate the drawbacks of the conventional ones as described above, and it involves moving the saw cutting crater while moving it and raising it at the same time as high pressure oxygen flows out, and then lowering it to the normal height after rising a certain distance. The purpose of this invention is to provide a working method that prevents molten iron oxide from adhering to the tip of the cutting nozzle from P.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings. Third
The figure is a diagram showing the movement of the cutting crater. In Figure 3, at the same time as high-pressure oxygen is released, the cutting crater is approximately 10 to 3
Approximately 70% of normal cutting speed in cutting direction while increasing by 0%
to move it and perform piercing.

〔Effect of the invention〕

As described above, according to the present invention, the cutting nozzle l is moved upward and forward at the same time as high-pressure oxygen is discharged, so there is no clogging of the nozzle due to scattering of molten iron oxide, and there is no need to clean the nozzle during cutting. It is effective in extending the life of the crater.

[Brief Description of the Drawings] Fig. 1 is a front view showing a cutting tip and a steel plate to be cut, Fig. 2 is a diagram showing the movement of a conventional cutting tip, and Fig. 3 is a cutting tip according to an embodiment of the present invention. This is a diagram showing the movement of . In the figure, (1) is a cutting crater, and (2) is a steel plate. In addition, in the figures, the same reference numerals indicate the same or corresponding parts. Agent Masuo Oiwa

Claims (1)

[Claims] In gas cutting by bringing the cutting nozzle close to the steel plate to be cut, the cutting nozzle is raised by about 10 to 30% while moving simultaneously with the outflow of high-pressure oxygen, and the speed in the cutting direction is about 70% of the normal cutting speed. A gas cutting method characterized by moving by.