A Study on Efficient Machining Method for Small Diameter Rods Made of Nickel Base Super Alloy

摘要

The development competition of the automatic driving and the electric car technology has been intense in the world. However, there is still much production of the clean diesel engine in Japan, including Europe. The clean diesel car is equipped with a turbocharger, and the nickel base super alloys as the parts materials are used. These are said to be difficult-to-cut materials, and grinding as the finishing process has been used until now. Therefore, there are still problems with the shortening of the cycle time, the reduction of the cost, and so on. This study deals with the valve stem machining and investigates experimentally the possibility of the substitution from the conventional centerless grinding to external turning. As a result, the surface integrity within the range of the customer demand was able to be obtained by external turning with the CNC lathe. Furthermore, the program operating with the opposed twine spindle CNC lathe led to success in the shortening of the cycle time, including the machining time, and the reduction of the cost.