METHOD OF MANUFACTURING A VALVE FOR AN INTERNAL COMBUSTION ENGINE

摘要

A method of manufacturing a valve (10) is provided, in which an intermediate valve product having a generally disk-shape valve head is formed by a die unit (20). The valve head is then machined to have a proper thickness and a tapered face on the periphery of the disk-shape valve head. The valve head is repeatedly forged in secondary forging by means of a die unit (40) equipped with a die (42) and a press punch (48) while angularly displacing the tapered face relative to the die (42) through a predetermined angle. Since the die (42) has protruding pressing sections and grooves (46) along the circumference of the die, a uniformly deformed and hardened valve face (16) is formed on the valve head.

主权项

1. A method of manufacturing a valve for an internal combusition engine, adapted to form a valve face on a periphery of the valve that comes into contact with a valve seat of the internal combustion engine, by creating radial slip deformations in the valve face of the intermediate valve product made of a heat resisting alloy, utilizing a die unit having:
a die equipped with pressing protrusions, arranged inside and along the circumference thereof, for forming the valve face, and a punch for pressing the front end of a valve head of the intermediate valve product, the method characterized by utilizing the die
wherein the die is provided with a multiplicity of grooves spaced apart from each other at equal angular intervals in the circumfrential direction thereof, each groove crossing an associated one of the pressing protrusions; and wherein the intermediate valve product and the die unit are rotated relative to each other through a predetermined angle in synchronism with the punch in operation.