| 摘要 |
A metallic gasket for use in an internal combustion engine has seals around the gasket openings which are formed by a two-step coining operation plus a folding operation. The gasket has a base plate including a folding portion located betwe en an edge of an opening and a fold line. A channel and a reduced thickness portion ar e formed in the folding portion by a first coining operation. The channel is spaced from the edge of the opening and spaced from the fold line. Next the folding portion is folded ba ck onto the base plate of the gasket. Finally, a second coining operation takes place to flatten the folded seal to a final thickness and produces material flow between the base pla te and the folding portion. |
