Development of tension-control type oil-pulse wrench

Abstract A tension-control type oil-pulse wrench has been developed. This wrench is similar in construction to the torque-control type, but it differs in that the tension is calculated for every impact based on the torque signal detected at the main shaft. Specifically, the increase in tension per impact is calculated by multiplying the peak torque pulse value by a torque-to-tension conversion coefficient on the basis of the tension before the impact, and then adding these results in order until the final value. The error of the tension value obtained in this manner is about ± 10% and the scatter of the tension is reduced to about ± 15%.