Kabushiki Kaisha Fujikoshi

Nissan Motor Sales Co., Ltd.

Tetsurou Miwa

Hiroshi Ando

Toshio Fujimori

Seiichi Akizuki

Toshiyuki Ishisaka

Satoshi Hosokawa

Yasutaka Gomyo

Akira Ito

Katsutoshi Yamaguchi

A vibrator has a hydraulic circuit connected with a hydraulic power unit. An electromagnetic valve disposed at the hydraulic circuit is regulated for the time for actuating a switch valve through a control signal. A plunger capable of bearing a load of an object to be tested at an upper end portion thereof has an oil chamber for pressurizing the plunger in such a manner as to be able to move upward and downward. An oil passage communicates with the oil chamber and with the electromagnetic valve. A vibration applying cylinder is capable of vibrating the plunger at a desired amplitude and frequency through hydraulic oil which is fed from the electromagnetic valve. A lift means lifts the vibration applying cylinder to a predetermined height. A controller capable of outputting, as a control signal, a setting signal for setting at least the amplitude and frequency of the plunger is provided. A control unit actuates the hydraulic power unit and the electromagnetic valve in accordance with the control signal.

Vibrator

Growing community of inventors

Toyama, Japan

Tetsurou Miwa