Provided is an injection molding apparatus including a first mold and a second mold, an ejector plate provided on the first mold to reciprocate and configured to eject an injection molded object between the first mold and the second mold, and a sensor device having a moving sensor detachably attached to the ejector plate, and configured to detect a position of the ejector plate, wherein the sensor device is detachably attached to the first mold and the ejector plate by a magnetic force.

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 molding machine includes: a mold that forms a molded product; an extrusion pin that transmits to the molded product an extrusion force for demolding the molded product from the mold, wherein the extrusion pin is inserted in the mold; and a control device configured to control the extrusion force of the extrusion pin. The control device controls the extrusion force at a first timing elapsed a first elapsed period so as to be greater than the extrusion force at second timing elapsed a second elapsed period. The first elapsed period is an elapsed period from a predetermined start point. The second period is an elapsed period from the start point and a shorter than the first elapsed period.

An injection molding machine includes a belt transmission mechanism (mold opening/closing mechanism, ejector mechanism, screw drive mechanism, injection mechanism) configured to transmit drive force from a driving shaft (driving pulley) to a driven shaft (driven pulley) by means of a belt. The injection molding machine includes: a cover covering part or entirety of the belt; and a sensor attached to the cover and configured to detect an abnormality of the belt.

Provided is an injection molding apparatus including a first mold and a second mold, an ejector plate provided on the first mold to reciprocate and configured to eject an injection molded object between the first mold and the second mold, and a sensor device having a moving sensor detachably attached to the ejector plate, and configured to detect a position of the ejector plate, wherein the sensor device is detachably attached to the first mold and the ejector plate by a magnetic force.

An abnormality detection device for detecting an abnormality of a movable part provided in an injection molding machine includes: a through hole formed in the movable part or in an adjacent member arranged adjacent to the movable part; and a microphone installed inside the through hole to collect sound generated by the movement of the movable part.

In an injection molding machine, a predetermined torque limit value set in advance and acceleration/deceleration torque calculated by an acceleration/deceleration torque calculation section are added to set an output torque limit value for a motor. By this operation, quick acceleration or deceleration can be achieved in an injection process, and breakage of a mold and mechanism section of the injection molding machine can be prevented.

An abnormality detection device for detecting an abnormality of a movable part provided in an injection molding machine includes: a through hole formed in the movable part or in an adjacent member arranged adjacent to the movable part; and a microphone installed inside the through hole to collect sound generated by the movement of the movable part.

A controller is configured to obtain a torque waveform of a servo motor while an ejector pin is operating, compare the torque waveform with a reference waveform obtained in advance, and determine that an ejector is abnormal when a difference between the torque waveform and the reference waveform exceeds a threshold value.