| 摘要 |
PURPOSE:To produce a lightweight hollow valve at a low cost with high working accuracy by drilling a blank steel bar material, and subjecting the drilled end faces to stem welding the to upset pressing. CONSTITUTION:A bevel head part 1 and a blank stem material 2 are cut and are drilled respectively to specified sizes. The drilled end faces are friction- welded and are then subjected to upset pressing and machining, by which the hollow valve is manufactured. The respective drilling depths are made shallow and the working is made easy by the above-mentioned method; further the bevel head part and cotter groove part where problems such as weld cracks are liable to arise are not welded and therefore the trouble during use is eliminated.
|
