Training molding precision verification manner null of spherical zone or spherical crown condition

摘要

PURPOSE:To observe the step formed in a base part and to check easily forging accuracy by using a die and an ejector having the forming surface which is smaller in diameter than the diameter of the base of the spherical forming surface thereof to forge spherical belt-like or spherical crown-like parts. CONSTITUTION:A spherical belt 11 is forged and formed by a die 12 having the spherical forming surface 12a for forming the spherical face 11a of the belt 11 and an annular forming surface 12 for forming the outside peripheral part of the base 11b of the belt 11 and the ejector 13 having the forming surface 13a which is smaller in diameter than the diameter of said base 11b. The steps 11e, 11f are formed by the base part 11d formed by said surface 12b and the base part 11c formed by the forming surface 13a of the ejector 13 when the distance between the forming surface 13a of the ejector 13 and the center 12d of the spherical forming surface 12a of the die 12 deviates from the prescribed value. The positioning accuracy of the ejector 13 is thus easily checked and the forging accuracy of the belt 11 is checked.