A hot-runner injection molding apparatus that facilitates use of actuators in a compact design includes a hot-runner manifold defining resin channels for conveying resin to nozzles that serve as conduits for introducing liquid resin into a mold cavity, a valve pin configured for linear movement along a longitudinal axis of the nozzle to control flow of liquid resin through the nozzle, and an actuator having a housing, wherein the valve pin is coupled to a drive shaft within the housing.

Disclosed herein, amongst other things, is a control structure for a molding system (900). The control structure includes a controller (106, 934) and a valve actuator (104) for positioning a valve member (102) of a valve (101) for regulating flow of molding material in the molding system (900), wherein the controller (106, 934) is configured to monitor an operating parameter of the valve actuator (104) for indirectly appreciating an indication of a molding parameter of the molding system (900).

An apparatus for controlling the rate of flow of a fluid mold material comprising: a manifold, an actuator interconnected to a valve pin, a position sensor that senses position of the valve pin, a controller that controls movement of the actuator according to instructions that instruct the actuator to drive the valve pin upstream at one or more selected intermediate velocities in response to receipt by the controller of a signal from the position sensor that the valve pin is disposed in the one or more intermediate upstream gate open positions.

Apparatus and method for detecting a position of an actuator piston driving a valve pin in an injection molding system. The apparatus includes an actuator housing having a body portion, surrounding an axial bore, of a substantially non-magnetic and/or magnetically permeable material, a piston, movable within the axial bore for driving a valve pin, the piston including a magnetic member generating a magnetic field such that axial movement of the piston in the bore modifies the magnetic field according to the position of the piston relative to a detection position, and a magnetic field detector attached to an exterior surface of the body portion at the detection position for detecting the magnetic field associated with the position of the piston and generating an output signal determined by the piston position.

An apparatus for controlling the rate of flow of mold material to a mold cavity, the apparatus comprising: an injection molding machine and a manifold; an actuator interconnected to a valve pin having a tip end; a valve system in fluid communication with the actuator to drive the actuator at one or more rates of travel, the valve system having a start position, one or more intermediate drive rate positions and a high drive rate position, the start position holding the valve pin in a gate closed position; a controller that instructs the valve system to move from the start position to the one or more intermediate drive rate positions and to remain in the one or more intermediate drive rate positions for one or more corresponding predetermined amounts of time.

Injection molding apparatuses and methods wherein a valve pin is controllably driven upstream and downstream along an axis between a first closed position where the tip end of the valve pin obstructs the gate to prevent the injection fluid from flowing into the cavity, a full open position and one or more intermediate positions, wherein the valve pin is drivable to be disposed or held in a selected intermediate position for a selected period of time during the course of an injection cycle where the tip end of the valve pin restricts flow of injection fluid through the gate to the mold cavity.

Injection molding system having a flow control apparatus and method that controls the movement and/or rate of movement of a valve pin over the course of an injection cycle to cause the pin to move to one or select positions and/or to control the rate of movement of the pin over the course of the injection cycle. In one embodiment the method includes steps of: a) first controllably operating the actuator to drive the valve pin upstream beginning from the first closed position (50) to be moved to and held in a first selected position (51) for a first selected period of time during the course of an injection cycle, the first selected position (51) being the full open position; b) second controllably operating the actuator to drive the valve pin, during the injection cycle, downstream beginning from the first selected position (51) to be moved to and held in a second closed position (52) for a second selected period of time; c) third controllably operating the actuator to drive the valve pin, during the injection cycle, upstream beginning from the second closed position (52) to be moved to and held in a second selected position (53) for a third selected period of time, the second selected position being an intermediate position or the full open position; and d) fourth controllably operating the actuator to drive the valve pin, during the injection cycle, downstream beginning from the second selected position (53) to be moved to a third closed position (54).

An apparatus for controlling the rate of flow of fluid mold material comprising: a manifold, a valve pin having a pin axis, a pin connector and a stem, the valve pin being drivable into and out of open and closed positions relative to the gate, an electric actuator comprising an electric motor comprised of a motor housing that houses a drive shaft having a drive gear and a drive axis, a transmission comprised of a transmission gear having a gear axis, the drive gear, the transmission gear and the valve pin being drivably interconnected and arranged such that the drive axis and the gear axis are non-coaxially mounted or disposed relative to each other and the valve pin is drivable linearly along the pin axis, wherein one or the other of the motor housing or the transmission housing are removably attached to a top clamping or mounting plate that is mounted upstream of the manifold and fixedly interconnected to a mold.

An injection molding apparatus comprising a manifold, an actuator having a piston that divides an enclosed actuator housing into upstream and downstream actuator drive chambers, the piston having an internal piston chamber and a piston bore that communicates flow of the drive fluid between one of the upstream or downstream actuator drive chambers and the internal piston chamber, a flow rate controller adapted to enable flow of drive fluid between one of the upstream or downstream actuator drive chambers and a source of drive fluid at a first low rate of flow over a selected first portion of the stroke length of the piston and at a second high rate of flow over a selected second portion of the stroke length of the piston.

A method and apparatus for performing an injection molding cycle comprising drivably interconnecting a valve pin to an electric motor actuator and controllably operating the electric motor to drive the valve pin at one or more reduced rates of upstream or downstream travel based on either detection of the position of the pin or actuator or on a preselected length of time at which to drive the valve pin.