CPC F01L 3/14 (2013.01) [B21D 22/16 (2013.01); B21K 1/22 (2013.01); F01L 2301/00 (2020.05)] | 15 Claims |
1. A method for producing a valve body of a hollow valve with optimized interior stem geometry, comprising the steps of:
providing a preform with a valve head and a tubular wall surrounding a cylindrical cavity;
flow forming the tubular wall over a mandrel, which is inserted into the cavity, to enlarge a length of the tubular wall,
wherein multiple forming rollers are used in the flow forming process;
wherein the mandrel is provided with a non-cylindrical outer surface structure, and wherein the multiple forming rollers are offset radially and axially to each other during the flow forming process.
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