| 摘要 |
<p>PURPOSE:To prevent, with certainty, the occurrence of shoulder sag at lateral ends of a cam surface by coating both lateral ends of a cam surface of a stock with ceramic heat insulating material and then remelting the cam surface by means of high energy beam. CONSTITUTION:A cam surface 7 of a camshaft stock 6 made of cast iron is rough-worked, while leaving a finish working allowance of about 0.6mm on the periphery. A ceramic heat insulating material 5 is applied to both lateral ends 71 of the cam surface 7 to about 300mum thickness over a width of about 1mm and dried. Subsequently, the cam surface 7 is remelting-chilled by irradiating the cam surface 7 with high energy beam, such as TIG 8. At this time both lateral ends of the cam surface 7 are free from the occurrence of shoulder sag. Then, finish working is applied to the above, by which the camshaft made of cast iron in which a chilled layer 72 is formed over the whole width of the cam surface 7 can be produced.</p> |
