| 摘要 |
<p>The fuel injection piping comprises a seat (3) at a free end of an end connection part of a thick wall steel piping (1), an annular flange (5) and a conical surface (4) connected to the seat extending from the seat to the annular flange and converging towards the free end of the part forming a connection head (2). A small depth annular cavity with a transverse curved section (4-1) is formed on a part of the conical surface. The cavity causes the formation of an annular cavity (1-1) on the surface of the connecting head during the die-making operation of the connecting head.</p> |
