YOKOTA in Japan developed the system wrench more than 30 years ago. The purpose of it being the tightening of threaded fasteners at high speed and accurate, with the possibility to count bolts in a group, have a detection method of errors during tightening and interact with the production line control systems, including the exchange of tightening data for traceability purposes. The latest developments have not only a torque transducer on the main shaft but also an angle encoder. By controlling the torque and monitoring the angle, all errors that can occur during the tightening process are detected (and acted upon).
Product liability is essential to car manufacture. All tightened joints have to be correct. For this reason critical joints must be counted, documented and, of course, tightened with the right clamping force. In order to do this, you need an impulse wrench (with a built-in transducer) connected to a controller.
This system ensures that only OK joints are counted resulting in “Zero Fault Production”. This fail-safe system fits perfectly in the Poka Yoke Strategy.