To improve compression efficiency by detecting a top dead center position of a piston, feedbacking a difference of the position from an expected value to the amplitude value of the piston, detecting a common frequency of a compressor and operating the piston by the common frequency.
A point which is the closest to a valve mounted on a cylinder 101 when a piston 102 reciprocates is detected as a top dead center location from a position signal of the piston 102 that a displacement detecting part 105 detects by a top dead center location detecting part 106. The resonance frequency of a system constituted of the piston 102 and a resonance spring 104 is detected by a resonance frequency detecting part 109. When the top dead center location is deviated from a preliminarily fixed value, an VAC Vac value that a driving part 103 impresses on the piston 102 is determined by a control part 110 based on the top dead center location. Further, the driving part 103 determines the frequency value of VAC Vac that the driving part 103 impresses on the piston 102, based on the resonance frequency.
YAMAMOTO HIDEO
SHIBUYA HIROMI
WATAKABE SHUSAKU
