PURPOSE: To improve flow rate precision by a method wherein given correction is applied on the gear shift pattern of a produced eccentric cam by a detecting pressure and a detecting displacement amount and based on a correcting gear shift pattern, a motor drive signal is produced, and an eccentric cam is rotated.
CONSTITUTION: The pressure of a pump 11a (11b) is detected by a pressure sensor and a displacement amount of a constant velocity pattern producing part 41 produces and stores the constant velocity pattern of an eccentric cam 24 for reciprocating the plunger 23. When the eccentric cam 24 is rotated at a constant velocity, based on detecting information from the two sensors, a gear shift pattern is corrected by a fundamental clock pattern producing part 44 according to the rotary angle of the eccentric cam 24. When the eccentric cam 24 is rotated in a correcting gear shift pattern, acceleration is corrected by a correction pattern producing part 48 during suction at a part corresponding to the suction stroke of a pump 11A (11B) so that a detecting pressure is rendered constant. The correcting gear shift pattern is outputted to a driver 49 to rotate the eccentric cam 24. This constitution improves processing precision and reduces cost without forming the eccentric cam in a complicated shape.
TAKESHIMA NAOTOSHI
TONOMURA MAKOTO
