Asmo Co., Ltd.

Honda Electronics Co., Ltd.

Yukinobu Tomida

Masahiko Komoda

Keisuke Honda

Toshiaki Miyamoto

Masanori Sato

Hideo Kouzaka

Yasuyoshi Honda

Ryosuke Suganuma

A drive circuit is used in a Langevin type ultrasonic bolt-tightening motor in which a motor drive voltage having a given frequency is applied to a piezo-electric element in a stator section, the resulting longitudinal and torsional vibrations being effective to rotate a motor section. The drive circuit has a longitudinal vibration sensor for detecting the longitudinal vibration in the stator section, a torsional vibration sensor for detecting vibration in the stator section and a frequency controller for controlling the frequency of the motor drive voltage such that the phase difference between the detection signals of the longitudinal and torsional vibration sensors becomes 90 degrees so as to provide maximum efficiency. Thus, the frequency of the motor drive voltage can be feedback controlled to maintain an optimum drive frequency despite the varying of the optimum drive frequency due to changes in various factors.

Drive circuit for langevin type ultrasonic bolt-tightening motor

Growing community of inventors

Aichi, Japan

Yukinobu Tomida