| 摘要 |
PROBLEM TO BE SOLVED: To simply manufacture a shaft of high quality by providing a base at one end and a cylinder having a tube clamping portion at the other end, and using an open end of the base as a fluid supply port and an opening end of the clamping portion as a fluid jet hole. SOLUTION: A mandrel 1 is formed of a cylinder having a base 2 and a tube clamping portion 3 and having a channel 4 therein. In this case, an opening end of the base 2 is used as a fluid supply port 4a, and an opening end of the portion 3 is used as a fluid jet hole 4b. A fluid supply cylinder C is engaged with the port 4a and is connected to an external fluid supply unit. A positioning groove 5 is formed between the base 2 and the portion 3. Thus, in the case of manufacturing a shaft such as a golf shaft, a fishing rod or the like by an internal pressure molding method, the shaft having a uniform radial thickness and high quality can be manufactured. |
