| 摘要 |
PURPOSE:To very easily perform positioning so as to enable work to be promptly attained by setting a carbon concentration gradient of a positioning pin, coming into contact with a cam piece positioning groove, higher than that of a shaft of steel material coming into contact with a cam piece shaft hole. CONSTITUTION:A hollow shaft 10 is a mechanical structure carbon steel pipe of 0.45 to 0.55% carbon amount, while a positioning pin 14 is a round steel material of 0.25% or less carbon amount, and a cam piece 16 is an iron system wear resisting sintered alloy of 1.5 to 4.0% carbon amount. Since the positioning pin 14 provides the carbon amount lower than that of the shaft 10, a carbon concentration gradient of the positioning pin 14 is higher than that of the shaft 10. Then a positioning groove 18 is first connected to a contact part of the positioning pin 14 serving as the reference of contracting the cam piece 16. Thus very easily performing positioning, work can be promptly attained. |
