| 摘要 |
PURPOSE:To obtain the worked item having smooth surface with a molten metal being adhered to the grain like item of fire-proof material by filling up the granular matter of refractory material in the space of the upper part of the inner part of a tubular body and by melting the position of the tubular body corresponding to the space. CONSTITUTION:A sand 6 is filled up so as to form some space on the upper part of the inner part of a steel pipe 1 and it is made to always form a space between the part to penetrate the steelpipe 1 and the sand 6. With this state the steel pipe 1 is cut continuously with rotating it in the arrow mark a direction by irradiating a laser beam 4 and by blowing working gas. The sand 6 is leaked out to the lower part from the cut part according to the cut part becoming downward gradually. In case of cutting the steel pipe 1 the minute molten metal at the cut place is dropped and scattered but the all is adhered to the sand 6 filled up inside the steel pipe 1. The work having the smooth inner face state of base metal is obtd. when the sand 6 is discharged after completion of the cutting. |
