US 12,343,778 B2
Die for ironing working and die module
Takuho Kumagai, Yokohama (JP); Kenichi Takao, Yokohama (JP); Ryozo Shiroishi, Yokohama (JP); Masahiro Shimamura, Yokohama (JP); and Naoya Matsumoto, Yokohama (JP)
Assigned to TOYO SEIKAN GROUP HOLDINGS, LTD., Tokyo (JP)
Filed by TOYO SEIKAN GROUP HOLDINGS, LTD., Tokyo (JP)
Filed on Nov. 16, 2020, as Appl. No. 17/099,487.
Application 17/099,487 is a continuation of application No. 15/750,224, abandoned, previously published as PCT/JP2016/073841, filed on Aug. 15, 2016.
Claims priority of application No. 2015-166675 (JP), filed on Aug. 26, 2015.
Prior Publication US 2021/0069767 A1, Mar. 11, 2021
Int. Cl. B21D 22/28 (2006.01); B21D 37/01 (2006.01); B21D 37/16 (2006.01); B21D 37/18 (2006.01); C23C 16/27 (2006.01)
CPC B21D 22/28 (2013.01) [B21D 37/01 (2013.01); C23C 16/27 (2013.01); B21D 37/16 (2013.01); B21D 37/18 (2013.01)] 2 Claims
OG exemplary drawing
 
1. A method of producing aluminum cans, including an ironing step by using a die module including a holder and an ironing die, wherein:
said ironing die has a carbon film that is so formed as to cover a working surface thereof;
said carbon film exhibits such a Raman spectrum that an intensity ratio represented by the following formula (1),
ID/IG  (1)
wherein ID is a maximum peak intensity at 1333±10 cm−1
in the Raman spectrum of the surface of said carbon film,
and IG is a maximum peak intensity at 1500±100 cm−1
in the Raman spectrum of the surface of said carbon film, is not less than 1.2;
the surface of said carbon film is a smooth surface having an arithmetic mean roughness R of not more than 0.05 μm;
said ironing step is executed in a dry process using no lubricant maintaining an ironing ratio which is in excess of 40%;
said ironing die having the working surface and a non-working surface, and being held by said holder in a manner of holding the non-working surface;
said holder permitting a temperature-control fluid to flow therein; and
said carbon film that covers the working surface extending up to the non-working surface so as to come in contact with the temperature-control fluid.