| 摘要 |
PURPOSE:To form a cam shaft having a large hollow part and to reduce the weight thereof by projecting radially branch cores from a core body and disposing longitudinally plural pieces of such branch cores. CONSTITUTION:Branch cores 5 are so formed as to project radially from the lateral circumferential surface 7 of a core body 6 and plural pieces of such cores 5 are disposed to the longitudinal direction of the core body 6, thereby constituting a core 4. Since the cores 5 are used as a core print in the stage of casting a hollow cam shaft 8 consisting of a cast iron by using such core 4, the supporting of the core 4 is easy and the venting of the gas is also made easy by the cores 5. Open holes 13 formed by the cores 5 after casting of the cam shaft 9 is used for stripping sand from the core 4. |
