| 摘要 |
<p>A method of manufacturing a valve for an internal combustion engine, comprising: a primary forging step for forming a generally disk-shape valve head; a thickness adjusting step of machining an excessively thick portion to adjust the thickness of the disk-shape valve head; and a secondary forging step for forming a valve face (16) by forging the periphery of the valve head to create radial slip deformations along the periphery of the disk-shape valve head. In the primary forging step, a tapered face (16a) is formed on the periphery of the disk-shape valve head. In the thickness adjustment step, only the front end of the disk-shape valve head is machined. Dense grain flow lines induced in the tapered face (16a) in the primary forging are grown more densely in the secondary forging, enhancing the hardness of the valve face. Thus, a rectangular corner of the disk-shape valve head needs not be tapered, which facilitates saving the valve material and reducing thickness adjustment time.</p> |
