Abstract: A method of and apparatus for controlling an injection molding machine by reproducing injection time and stability of an inspection speed to thereby improve precision, stable moldability. In the injection molding machine, a nozzle valve (4) for changing the opening of this nozzle is disposed at the tip of the nozzle for injecting a molten resin, the degree of opening of this nozzle valve (4) is controlled to a predetermined quantity of opening in accordance with a preset screw moving position and the flow rate of an operation oil for pushing a screw (6) is controlled in accordance with the degree of opening of the nozzle valve (4).

Abstract: A control apparatus for an injection molding machine injects a melted resin within a housing into a cavity of a mold through a nozzle section of a nozzle at a housing and by movement of a screw. A nozzle opening changing mechanism variably changes a throttled path area of the nozzle while a mold temperature sensing mechanism sensing the temperature of the mold. A control mechanism controls the nozzle opening changing mechanism in accordance with the sensed temperature of the mold temperature sensing mechanism.

Abstract: An injection molding machine of the present invention has a flow rate control device (11) located between an injection screw (2) mounted inside a housing (1) so that it may be rotated freely and reciprocated freely and an injection nozzle (12) mounted in the leading end of the housing (1) so as to inject the molten resin into a cavity (14) of a mold (13). The control device serves to control the rate of flow of the molten resin from the injection screw (2) to the injection nozzle (12). The flow rate control device (11) cooperates with an injection speed control device and a dwell pressure control device installed separately to control the flow rate and speed of the molten resin thereby making it possible to control the injection speed rapidly, and with a high accuracy and with an excellent response.