A screw driving device includes: a plasticization motor; a rotation drive shaft provided coaxially with a screw and configured to rotate the screw; and a transmission mechanism configured to decelerate rotation of the plasticization motor and transmit the rotation to the rotation drive shaft. The transmission mechanism includes: a speed reducer whose output shaft is coupled to the rotation drive shaft; a drive rotation member provided in the plasticization motor; a driven rotation member provided on an input shaft of the speed reducer; and one endless string-shaped force transmission member wound around the drive rotation member and the driven rotation member.

A method of detecting and compensating for a non-operational mold cavity in an injection molding apparatus having a plurality of mold cavities and an injection molding screw or ram includes injecting, via the injection molding screw or ram, a molten thermoplastic material into the plurality of mold cavities. The method includes measuring a first process parameter of the injection molding apparatus at a pre-determined time during or after the injecting. The method also includes determining, based on the first process parameter, whether one or more mold cavities of the plurality of mold cavities are non-operational. Then, when it is determined that one or more mold cavities are non-operational, the method includes automatically adjusting the first process parameter or a second process parameter of the injection molding apparatus.

A method of detecting and compensating for a non-operational mold cavity in an injection molding apparatus having a plurality of mold cavities and an injection molding screw or ram includes injecting, via the injection molding screw or ram, a molten thermoplastic material into the plurality of mold cavities. The method includes measuring a first process parameter of the injection molding apparatus at a pre-determined time during or after the injecting. The method also includes determining, based on the first process parameter, whether one or more mold cavities of the plurality of mold cavities are non-operational. Then, when it is determined that one or more mold cavities are non-operational, the method includes automatically adjusting the first process parameter or a second process parameter of the injection molding apparatus.

An injection molding machine for foam molding includes a heating cylinder having a gas injection port, a screw which is drivable in the heating cylinder, a gas supply device configured to supply a gas to the gas injection port, the gas supply device including a valve mechanism in a gas flow path, and a control device. The control device is configured to control the valve mechanism to close the valve mechanism at least once in a molding cycle, and keep the valve mechanism open at least in a measuring step.

An injection molding machine for foam molding includes a heating cylinder having a gas injection port, a screw which is drivable in the heating cylinder, a gas supply device configured to supply a gas to the gas injection port, the gas supply device including a valve mechanism in a gas flow path, and a control device. The control device is configured to control the valve mechanism to close the valve mechanism at least once in a molding cycle, and keep the valve mechanism open at least in a measuring step.

A plasticizing unit is provided for an injection unit of an injection moulding machine with a support element arranged beneath the cylinder and connected therewith. To simplify adjusting of the nozzle centre, a fixing element surrounds the end of the support element facing away from the cylinder such that a distance is present between the fixing element and the support element. Several adjusting elements are provided, to produce a force-fitting and/or form-fitting connection between the fixing element and the support element to adjust the position of the support element relative to the fixing element in a plane orthogonally to the cylinder axis. The plasticizing unit can be clamped in and out with its fixing element in a clamping- and positioning system connected with the machine bed. On changeover of the plasticizing unit, an adjusting of the nozzle centre, which has been carried out once, is retained.

A plasticizing device includes a plasticizing cylinder and a plasticizing screw arranged in the plasticizing cylinder. The plasticizing screw is rotatable about, and linearly movable along, a longitudinal axis. The plasticizing screw comprises a functioning section. A sensor is arranged in or on the plasticizing cylinder, and a distance to the surface of the functioning section of the plasticizing screw can be measured by the sensor. A detecting device can detect a type of the functioning section and/or an operating state of the functioning section, can detect a distance signal progression by a movement of the functioning section relative to the sensor, can compare the detected distance signal progression with a stored distance signal progression, and can issue a signal representing the type of functioning section and/or the operating state of the functioning section depending on a matching of the detected distance signal progression with a stored distance signal progression.

A plasticizing device includes a plasticizing cylinder and a plasticizing screw arranged in the plasticizing cylinder. The plasticizing screw is rotatable about, and linearly movable along, a longitudinal axis. The plasticizing screw comprises a functioning section. A sensor is arranged in or on the plasticizing cylinder, and a distance to the surface of the functioning section of the plasticizing screw can be measured by the sensor. A detecting device can detect a type of the functioning section and/or an operating state of the functioning section, can detect a distance signal progression by a movement of the functioning section relative to the sensor, can compare the detected distance signal progression with a stored distance signal progression, and can issue a signal representing the type of functioning section and/or the operating state of the functioning section depending on a matching of the detected distance signal progression with a stored distance signal progression.

An injection molding machine includes: a screw inserted in an injection cylinder and configured to be movable in the axial direction; a motor configured to move the screw; a torque detection unit configured to detect the torque of the motor; a position detection unit configured to detect the position of the screw; a motor drive control unit configured to drive the motor while imposing torque limitation so that the motor's torque will not exceed a limit torque, to thereby advance the screw to the foremost position in the direction of injection; and a determination unit configured to determine that unmelted resin remains inside the injection cylinder if the moving speed of the screw becomes lower than or equal to a predetermined speed while the screw is advancing to the foremost position.

An injection molding machine includes: a screw inserted in an injection cylinder and configured to be movable in the axial direction; a motor configured to move the screw; a torque detection unit configured to detect the torque of the motor; a position detection unit configured to detect the position of the screw; a motor drive control unit configured to drive the motor while imposing torque limitation so that the motor's torque will not exceed a limit torque, to thereby advance the screw to the foremost position in the direction of injection; and a determination unit configured to determine that unmelted resin remains inside the injection cylinder if the moving speed of the screw becomes lower than or equal to a predetermined speed while the screw is advancing to the foremost position.