Investigations on the Differential Speed Type Thread Rolling Machine : 2 nd Report, Rolling Power and the Calculation of the Outside Diameter of Rolling Die

Abstract

In the second report the following problems of the differential speed type thread rolling machine are discussed : (1) the power required for thread rolling, (2) the axial movement of the blank during thread rolling, (3) the calculation of the outside diameter of the die. The tangential force acting on the die is the most important factor of the power required for thread rolling. Also the power consumed at the parts of the power transmission mechanism must be considered. The output of the main motor in the case where the screw thread is rolled by the differential speed type thread rolling machine was measured. The experimental values were compared with the values estimated on the basis of the rolling pressure and the tangential force. Both values show good agreement. It is desirable to make the axial movement of the blank during the thread rolling as small as possible. The amount of the axial movement of the blank on the industrialized machine was measured. The experimental values agree with the values calculated according to Yamamoto's theory. The method of calculating the outside diameter of the die, in which the amount of the axial movement of the blank is minimized and the effective working zones are uniformly distributed over the die surface, was established.