| 摘要 |
PURPOSE:To provide a titled device which can form a blank material for a shadow mask to a uniformly curved surface by providing a stepped part having a prescribed slope part to the opposed surfaces of a holder part which presses the peripheral part of the blank material and a die which holds the blank material. CONSTITUTION:This device for forming the shadow mask consists of a blank holder 7, a die 8 disposed to face the blank holder, a punch 9 slidable in the blank holder 7 and a pad 10 slidable in the die 8. A holding recess 7a and projecting part 8a respectively having the prescribed bending angle theta1 are formed on the respective opposed surfaces of the blank holder 7 and die 8 of the above- mentioned device. The blank material 1 for the shadow mask is pressed and held by the above-mentioned blank holder 7 and the die 8 and the peripheral part is bent at the angle theta1, by which the blank material is formed to have the slope part. The punch 9 is then lowered to form the curved surface and thereafter the blank holder 7 is slightly risen and the punch 9 and the pad 10 are simultaneously lowered to bend the peripheral part to a square shape. The mask skirt part is thereby formed. |
