| 摘要 |
PURPOSE:To remove the minute disarrangement, distorsion, cutting flaw, etc. on the inner face of a tubular member, by idly fitting a tubular member into a molding core member having lower expansion factor, then heating them and releasing the residual stress in the tubular member thereafter cooling the tubular member. CONSTITUTION:A molding core member 2 is made of such material as having the expansion factor lower than that of a tubular member 1, where the hardness of the outer face is considerably higher than the inner face of said member 1. After idly fitting said member 1 into said member 2, they are heated with the predetermined temperature to release the residual stress in said member 1. Then only said member 1 is cooled by apraying the water. Consequently said member 1 will press tightly against the outer face of the enlarged molding core member 2. As a result the inner face of said member 1 can be formed and finished in accordance to the shape, dimension and the finish accuracy of the outer face of said member 2. |
