Development of axial bolting force control equipment using ultrasonics

Direct control of the axial bolting force used to secure important bolts when fastening and assembling is desirable to raise their reliability as fasteners, which have an important fuction as constituents of facilities and are used in a severe atmosphere. A direct control equipment of axial bolting force using ultrasonics has been developed and applied to actual facilities to satisfy the above-mentioned requirements in MHI. This equipment can be expected to be used widely for the fastening of important components and to raise accuracy of control of the axial bolting force. This equipment is composed of an ultrasonic sensor, an ultrasonic bolt gage, a conditioning processor and an indicator. This paper describes the principle of measuring axial bolting force using ultrasonics, and the functions, features and examples of application of the equipment developed. (author)