| 摘要 |
<p>A die for use in a stage of a multi-stage die-necking process of a metal body such as a drinks can, has a surface around a centre-line. The die surface, seen in longitudinal section through the centre-line, has a profile which comprises in direct succession a feed-in zone, an intermediate zone and a neck zone. The intermediate zone has, as well as a contact part, a relatively steep part in which tangents to the die surface include an angle alpha to the centre-line greater than alpha n, where alpha n is the neck angle between the necked part following die-necking and the centre-line of the body. The presence of this non-contact steep part reduces the axial force needed in the die-necking. <IMAGE></p> |
