DEVICE FOR COMPRESSING AND EXPANDING METAL MATERIAL

摘要

PROBLEM TO BE SOLVED: To provide a device for compressing and expanding metal materials with which sections and tubes are formed by compressing and expanding a metal bar. SOLUTION: This compressing and expanding device has a movable hollow die 2 which is engaged with a washer 4 through a spline 3. The washer 4 is engaged with a fixed ring 6 through a spline 5 and, on the other hand, the fixed ring 6 is supported with a thrust bearing 7 and also connected with a reverse rotation driving mechanism part. This reverse rotation driving mechanism part is engageable with a series of splines 10 which are mounted on the fixed ring 6 and also connected with a driving part. The diameter of the hole 12 in a housing 1 is made smaller than the outside diameter of the movable hollow die 2 and supplementary relief 13 is provided in the front part of this hollow die 2.