S112033 軸方向荷重増減下におけるプリベリングトルク形六角ナットのゆるみ特性 : かしめる形式([S11203]機械要素の設計・製造・応用技術(3))

Abstract

The self-loosening is one of the major problems of bolted joints which should ensure high reliability. Nowadays, various kinds of locking devices are widely used in bolted joints for anti-loosening purposes. Recently, the prevailing torque type nuts have been paid a lot of attention and widely developed and used in bolted joints for preventing self-loosening. Thus, the standards on prevailing torque type nuts have been specified in JIS. However, only few researches have been reported on the loosening mechanism of the prevailing torque type nuts under repeated tensile loads. The effects of the anti-loosening is not elucidated. In this paper, experiments were carried out to measure the self-loosening of bolted joints with prevailing torque type nuts, under repeated tensile loads. As the result, the performance for anti-screw thread loosening of the two type nuts which is calking the inner thread surface in the radial direction is better than that of conventional nuts.