METHOD OF PRESS-WORKING FRAME PLATE ON WHICH DISK DRIVING MOTOR IS ARRANGED

摘要

In a card-type magnetic recording device (1), a motor (10) for driving a magnetic disk stored therein is mounted in a recess (9) that is formed in a frame plate (8). In order to form the recess (9) in the frame plate (8), backward extrusion molding is effected by means of a die (35) having a slope (39) and a punch (37) having a slope (40). A region between the slope (39) and the slope (40) is crushed by means of the die (35) and the punch (37) that relatively move up and down, and extends backward as well as forward with respect to the moving direction of the punch.