Apparatus for injection molding of plastic materials having a mold including at least one plate, a hot runner distributor of the fluid plastic material, at least one injector and an electric motor for controlling opening and the closing of the injector, supported by the distributor and whose cooling is carried out by means of thermal exchange contact with the plate. Provided for the cooling of the electric motor is at least one cover made of thermally conductive material at least partly surrounding the electric motor in a slidable manner and it is maintained in thermal exchange contact with the plate by means of a magnetic or an electro-magnetic force.

Apparatus for injection molding of plastic materials comprising a mold including at least one plate, a hot runner distributor of the fluid plastic material, at least one injector and an actuator for controlling the opening and the closing of the injector, supported by the distributor and whose cooling is carried out by means of thermal exchange contact with the plate. Provided for the cooling of the jack actuator provided for is at least one cover made of thermally conductive material at least partly surrounding the actuator in an axially slidable manner and it is maintained in thermal exchange contact with the plate by means of a magnetic or an electro-magnetic force.

An injection apparatus for injecting molten plastic into a mold of articles made of thermoplastic material including bottle preforms. The injection apparatus includes an injection nozzle and a shutter for controlling flow of the molten plastic through the injection nozzle. A cylinder-piston system moves the shutter from open and closed positions of the injection nozzle. The cylinder-piston system includes a first chamber with a first passage for introducing fluid into the first chamber to open the shutter, and a second passage, different from the first passage, for discharge of fluid and of possible particles from the first chamber. A fluid distribution device with a first channel is connected to the first passage, and a second channel different from the first channel is connected to the second passage. The cylinder-piston system includes a second chamber having a third passage for introducing fluid into the second chamber to close the shutter.

An injection molding apparatus is described. It comprises a press equipped with a screw for generating molten material, and a signal generator for generating a control signal adapted for a plurality of directional valves so that they can regulate the movement of one or more actuators adapted for controlling the movement of one or more shutters which regulate a flow of molten material to the mold.

There is a signal converter connected between the press and the mold for converting the signal emitted by the generator into a signal adapted for activating one or more electric actuators, wherein the signal converter is external to the press and the mold.

A molded resin component includes a first surface on which a convex portion is formed, and a second surface opposite to the first surface. The convex portion includes a molding mark formed by a valve pin of a manufacturing apparatus that manufactured the molded resin component. A shape of at least a portion of a leading-end surface of the valve pin is not transferred into the molding mark.

A system is disclosed for driving an actuator which comprises a chamber, a shutter of an injection nozzle for molten material for injection molding, and a piston translatable inside the chamber to actuate a shutter. Means are provided for the transfer of a predetermined amount of fluid between the outside and inside of the chamber, so as to bring/move the shutter from a closing position, in which there is no passage of molten material, towards an opening position, in which there is passage of molten material, by injecting the predetermined amount of fluid from the outside into the chamber or by injecting the predetermined amount of fluid from the chamber towards the outside, or vice versa.

An injection molding apparatus (5), comprising: a first fluid drive cylinder (940c, 941c, 942c), a second fluid drive cylinder (940ac, 941ac, 942ac) interconnected to a valve pin (1040, 1041, 1042), wherein the first fluid drive cylinder (940c, 941c, 942c) and the second fluid drive cylinder (940ac, 941ac, 942ac) are interconnected in an arrangement wherein reciprocating movement of a piston (940p, 941p, 942p) of the first cylinder drives concomitant back and forth movement of a piston (940ap, 941ap, 942ap) of the second cylinder and concomitant back and forth movement of the valve pin (1040, 1041, 1042); an electrically powered actuator (940, 941, 942) adapted to drive the piston of the first cylinder reciprocally according to a drive program such that the valve pin (1040, 1041, 1042) is driven between gate closed and gate open positions and selected positions therebetween.

A method for injection molding of plastic materials into a cavity of a mold by means of a molding apparatus including at least one injector having a pin valve displaceable between a fully closed position and a maximum opening position, and vice versa, in a controlled fashion in respect of its position and speed. In the opening displacement from the fully closed position to the maximum opening position, the pin valve is initially moved at a first speed and subsequently at a second speed, where the first speed is the highest opening displacement speed of the pin valve.

A system and method for controlling an actuator which actuates an axially displaceable pin valve of an apparatus for injection molding of plastic materials, where the control system includes an electronic control unit of the actuator which adjusts at least one among position, speed and acceleration of the pin valve, and a position sensor which detects a position of a plunger of the actuator and is operatively connected to the electronic control unit. The position sensor indirectly detects the position of the plunger of the actuator.

Injection molding apparatus (1) comprising: an actuator (14, 940, 941, 942) comprising a rotor (940r, 941r, 942r) controllably rotatable by electric power, the actuator (14, 940, 941, 942) being interconnected to a controller (16) that generates drive signals (DC), an electrical drive device (940d, 941d, 942d) comprising an interface that receives the drive signals (DC) and controllably distributes electrical energy or power in controllably varied amounts according to the drive signals (DC) to a driver (940dr, 941dr, 942dr) that drives the rotor (940r, 941r, 942r), a valve pin (1040, 1041, 1042) having an axis (X) and a control surface (43, 45, 102m) drivable upstream and downstream through a downstream feed channel (17, 19, 160, 940c, 941c, 942c) the downstream feed channel having a complementary surface (47, 103s) adapted to interface with the control surface (43, 45, 102m) upstream and away from the gate.