| 摘要 |
PURPOSE:To provide a new cutting method of the top end part of a tube which can make small the welding amount and the frequency of weld flaw in a case of welding a tube of the top end part of a tube onto a tube's outer circumferential part. CONSTITUTION:In a time of cutting the top end part or a tube B matching to the shape of an other tube's A outer circumferential surface, cutting is executed along a prescribed cutting line which is obtained by preliminarily calculating. In this cutting line, the required place is essentially inclined following the shape of the other tube's A outer circumferential surface. Therefore, a clearance g when the top end part B' after completing cutting is engaged onto the outer circumferential surface of the other tube A is reduced. So, because the clearance g is reduced, the welding amount and the flaw welding amount in a time of welding both tubes A, B can be reduced than the conventional time. |
