| 摘要 |
PURPOSE:To improve the productivity by shortening the warming up time of an injec tion molder by a method wherein a screw actuating circuit, which allows to immediate ly rotate a screw, if the temperature in a heating cylinder lies within a certain allow able range to the predetermined temperature, when the power source is put to work again, is provided. CONSTITUTION:When the temperature of a heating cylinder lies within the lower limit of or a little below the proportional band of the set temperature of a temperature controller 1 under the condition that the power source of a heater is once turned off and again turned on in the midway of molding process, a relay R1 in the circuit (1)is energized and consequently the b-contact of a temperature control unit ATC in the circuit (3) and the a-contact of the temperature control unit ATC in the circuit (6)repeats by all means the ON-OFF action within the proportional period of 30s, for example. Even when the temperature of the heating cylinder is lower than the above-mentioned state, if said temperature rises in the proportional band of the tempera ture control unit ATC within the range of the actuating time of a timer T2, the timer T2 resets to its initial state and no time-up results. Consequently, a relay R3 in the circuit (7) does not also energized and the b-contact of a relay R3 in the circuit (4)remains conducting and a relay R3 is energized and accordingly a screw 9 can be actuated. |
