DEVIATED THICKNESS SECTION FORMING METHOD OF LIGHT ALLOY AND PRODUCTION OF LIGHT ALLOY RIM

摘要

PURPOSE:To make possible deviated thickness working through roll forming and further achieve the production rationalization of the light alloy rim by making the end bending process of a strip- form blank and the pressure-deforming process following to this continuous. CONSTITUTION:A strip-form blank M is passed continuously through the roll sets 5, 5 each consisting of a roll 3 having large diameter parts 2, 2 at both ends and a smooth roll 4 entering between the large dimeter parts by having a suitable allowance by which rising parts 6, 6 are formed at both ends of the blank M, in the 1st process A. Next, in the 2nd process B, the blank 1 passed through the process A is continuously passed through roll sets 7, 7, by which the lug parts 1, 1 of a rim sectional shape are finish-formed. In this case, the respective roll sts 7, 7 are formed by the smooth rolls 8 and the rolls 10 provided with a pair of concave grooves 9, 9 at the both ends so that the rising parts 6, 6 are formed to lug parts 6, 6 while the blank is being passed through said roll sets 7, 7. After this, the blank M is finished to the rim sectional shape in the similar manner as in conventional methods in the 3rd process C. Fruther, it is passed through a bending process D to be bent to suitable coil form, thence one coil thereof is cut and the opened parts are joined to complete the endless ring-form rim.