To provide a bolt tightening apparatus that structurally simply micro-vibrates a bolt at right angles to the bolt axis when tightening the bolt.
A reducing eccentric cam 16 directly coupled to an input rotary shaft 14 fits peripheral external teeth with internal teeth on an inner circumference of a case 12A. The internal gear 12 synchronously rotates a coaxial, slow rotation rotor 20 via rotation transmission pins 22 to rotate a socket wrench 150, which tightens a bolt 110. A displacement controlling eccentric cam 24 is fixed at the rotation center of the reducing eccentric cam 16 so as to penetrate the rotation center of the slow rotation rotor 20. The displacement controlling eccentric cam 24 holds an axially penetrating displacement controlling pin 26 enclosed with double eccentric rings 24. The external teeth are fewer than the internal teeth. The rotation axes of the input rotary shaft 14 and displacement controlling pin 26 are offset, and the offset is adjusted by the rotational position of the double eccentric rings 24.
MURAKAMI KOJI
AOYAMA SEISAKUSHO
Kato Kazunori
Hiroshi Fukuda