PURPOSE: To provide a hollow die for extruding aluminum alloy containing zinc capable of preventing a crack and prolonging the service life of the die without changing a structure so much.
CONSTITUTION: Bridges 19a and 19b are covered with a cover 25 so as to cover the surface of a mandrel member 13 side, and a fitting part 27 for fitting the cover 25 is formed in a recessed shape over a part of an outer cylinder member 11 from the surfaces of the bridges 19a and 19b. The cover 25 consists of the same steel as a die 1, and a through hole 25b through which the mandrel member 13 is passed is provided on a sheet-shaped substrate 25a. On both sides of this through hole 25b, projection sheets 25c arranged in parallel with the mandrel member 13 are provided. Also, parts corresponding to the bridges 19a and 19b of the substrate 25a are formed in a smooth projection shape like the bridge surfaces of conventional die.
| JP5579425 | Extrusion dice |
SATO FUMIHIKO
WAKABAYASHI HIROYUKI
TANAKA YASUYUKI
KUMAZAKI HIDENORI
