抄録
The efficiency of repeated impulse piercing machine is greatly affected by the character of working fluid. For example the piercing speed with telepin oil is approximately 2 times as high as that of the case with light oil, and with water it becomes almost one tenth smaller than in the former case. In this paper the author explained the above-stated facts in relation to the circulation of working fluid and proved that the fluid of smaller viscosity and smaller surface tension is more suitable as working fluid.
