An injection molding machine includes a screw inserted in an injection cylinder and configured to be movable in an axial direction of the screw, a motor configured to move the screw, a torque detection unit configured to detect a torque of the motor, a position detection unit configured to detect a position of the screw, a motor drive control unit configured to drive the motor to thereby advance the screw to a foremost position in a direction of injection, a processor, and a memory. The processor and memory are configured to determine that unmelted resin remains inside the injection cylinder if the torque of the motor becomes equal to or greater than a limit torque while the screw is advancing to the foremost position.

A control device for an injection molding machine including a cylinder into which a resin is supplied and a screw that moves forward and rearward and rotates inside the cylinder, includes a metering control unit that performs metering of the resin inside the cylinder by controlling forward rotation and rearward movement of the screw until the screw has been moved rearward to a predetermined metering position, based on predetermined metering conditions, a rearward movement speed acquisition unit acquiring a rearward movement speed of the screw, a speed determination unit that determines a suck back speed for causing a resin pressure to reach a target pressure, based on the rearward movement speed acquired during metering by the rearward movement speed acquisition unit, and a suck back control unit causing the screw to move further rearward based on the suck back speed, after the screw has reached the predetermined metering position.

An abnormality detection apparatus for detecting an abnormality of a ball screw provided in an injection molding machine includes a current sensor configured to detect an alternating current of a motor for applying a driving force to the ball screw; and a computation unit configured to detect an abnormality of the ball screw based on information related to a distribution of frequency components obtained by frequency analysis of an alternating current detected by the current sensor, and information related to a distribution of frequency components obtained by frequency analysis of an alternating current detected when the ball screw, which is normal, operates.

A method for monitoring the hydraulic supply system of a plastic processing machine. In order to monitor the state of the hydraulic system without great effort, the method includes the following steps: a) Prior to operation of the machine: Determination of the nominal flow rate of a hydraulic pump as a function of an operating parameter of the hydraulic pump and determination of the nominal displacement speed of the hydraulically driven axis when a piston-cylinder element is acted upon by a predetermined nominal flow rate; b) During operation of the machine: When the hydraulically driven axis is operated: measuring the at least one operating parameter of the hydraulic pump as well as the actual displacement speed of the hydraulic axis and comparing the actual displacement speed with the nominal displacement speed resulting from the previously measured operating parameter of the hydraulic pump, and outputting the result of the comparison.

A drive mechanism for an injection molding machine that causes a movable object to undergo movement includes a driving motor that generates a driving force, a drive pulley connected to the driving motor, a driven pulley connected to the movable object, and a plurality of belts (a wide belt and a narrow belt) of equal length, the belts being arranged in parallel with each other and trained around the drive pulley and the driven pulley.

The present disclosure prevents load from being produced in an injection molding machine. The control device for an injection molding machine according to one embodiment of the present disclosure has a determining part that is configured to determine, based on information detected in accordance with a movement of a measurement motor provided in the injection molding machine, whether or not an operation of removing or attaching a screw that rotates in accordance with the measurement motor has been performed.

An electric injection molding machine includes an injection apparatus including a screw configured to inject a resin, a driving direction conversion part configured to move the injection apparatus forward and backward in an axial direction of the screw, and a first motor coaxially connected to a rotation shaft of the driving direction conversion part, the first motor being configured to drive the driving direction conversion part. The first motor includes a motor connection part, the motor connection part being configured to connect a second motor to the first motor coaxially with the driving direction conversion part on a side of the first motor opposite to a side thereof on which the driving direction conversion part is connected thereto, the second motor being configured to drive the driving direction conversion part in an interlocking manner with the first motor.

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 abnormality detection device includes a servo CPU; a physical quantity detection unit which detects a physical quantity such as a load applied on a servo motor which operates a movable part included in an injection molding machine. The abnormality detection device further includes a first storage unit directly readable/writable by the servo CPU; and a second storage unit not directly readable/writable by the servo CPU. A reference physical quantity is stored in the first and second storage units. The servo CPU outputs an instruction for stopping or decelerating the movable part in response to a first physical quantity deviation, which is a deviation between a reference physical quantity read from the first storage unit and a current physical quantity, or a second physical quantity deviation, which is a deviation between a reference physical quantity read from the second storage unit and a current physical quantity, exceeds a threshold value.

A hydraulic drive apparatus includes a first hydraulic pump, a drive motor connected to the first hydraulic pump, a hydraulic line system connecting the first hydraulic pump to the consumer, and a closed-loop control unit. The closed-loop control unit has a first switching element to change a displacement volume of the first hydraulic pump between a predetermined minimum value and a maximum value. A second hydraulic pump is connected to the drive motor, and the hydraulic line system connects the second hydraulic pump to a consumer and has a first branch line connected to the first hydraulic pump, a second branch line connected to a second hydraulic pump, and a main line. The two branch lines open into the main line, and the closed-loop control unit has a second switching element for changing a displacement volume of the second hydraulic pump between a predetermined minimum value and a maximum value.