INJECTION CONTROL METHOD FOR INJECTION MOLDING MACHINE

PROBLEM TO BE SOLVED: To effectively suppress sudden pressure fluctuation and to stabilize suppression to attain further improvement of quality and uniformity of molded products. SOLUTION: Speed target values V1 etc. and a predetermined limit pressure Ps that pressure P can reach in a filling process Zi are set beforehand to perform trial molding, and speed data Dv concerning the injection speed V of trial molding in which a non-defective product can be obtained is detected. Predetermined speed change patterns Vp obtained from the speed data Dv after the pressure P has reached the limit pressure Ps are registered as speed control patterns Vs etc., and feedback control of the injection speed V is performed to obtain the speed target values V1 etc. in mass molding. When the pressure P reaches a limit detection pressure Pss corresponding to the limit pressure Ps, speed control of the injection speed V based on the speed control patterns Vs etc. is performed until reaching the following switching points tc etc. COPYRIGHT: (C)2009,JPO&INPIT