To provide a bulging method which can make the thickness of a product almost uniform, and can easily form a required shape even in an uneven shape portion having an unsymmetrical cross section in the right and left direction.
First contact points of a preliminarily formed body 38 with an upper finish forming die 42 and a lower finish forming die 40 are designated as a point A and a point B respectively, and the length from the point A to the point B on the left side is designated as the length of a first portion 46, and the length from the point A to the point B on the right side is designated as the length of a second portion 48 respectively. Further, points on the forming surface of a cavity 44 located opposite to the point A and the point B are designated as a point C and a point D respectively, and the length from the point C to the point D on the left side is designated as the length of a third portion 50, and the length from the point C to the point D on the right side is designated as the length of a fourth portion 52 respectively. The preliminarily formed body 38 is formed such that the length of the first portion 46 is nearly equal to the length of the third portion 50, and the length of the second portion 48 is nearly equal to the length of the fourth portion 52.
KOBAYASHI TAKUO
MIZUTANI YOSHIKI
NAGAI YUICHI
HORI IZURU
YAMAMOTO DAISUKE
| JP2003126923A | 2003-05-08 | |||
| JP2002263747A | 2002-09-17 | |||
| JP2000153314A | 2000-06-06 | |||
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| JP2002045922A | 2002-02-12 |
Toshiyuki Miyadera
Tatsuhiko Sato