Abstract:
The force pushing the ejector pin when a molded product is ejected is obtained from the driving torque of the servomotor. A malfunction is detected in the ejection step as follows. First, a reference pattern is obtained in advance, when a molded product is normally removed. As the reference pattern, the relationship between torque of the servomotor and time from the initiation of ejecting the ejector pin or the position of an ejector pin is used. At least one monitoring zone is set based on the pattern and the upper and lower limits of torque of each of the monitoring zones are set. A torque value is monitored in each monitoring zone and when the torque value falls outside the upper and lower limits of any one of the monitoring zones, it is determined that a malfunction occurred and an alarm is raised.
Abstract:
A nozzle internal resin pressure feedback control system has a mold internal pressure sensor for measuring a mold internal resin pressure as a measured mold internal pressure value. The measured mold internal pressure value is fed to the nozzle internal resin pressure feedback control system, and a nozzle internal pressure preset value in the nozzle internal resin pressure feedback control system is changed in accordance with a difference between the measured mold internal pressure value and the mold internal pressure preset value.
Abstract:
A method for monitoring abnormality of a mold-clamping mechanism of a molding machine and for estimating the amount of abrasion in the toggle mechanism without disassembling a mold-clamping mechanism in the molding machine to allow manual inspection. The timing and content of maintenance to be performed is determined based on measurements of stress at the toggle mechanism, from which the amount of abrasion in the toggle is calculated. This method makes it possible to operate the machine until the time just before a product quality deficiency occurs, thereby allowing maintenance to be performed with a minimum of machine disassembly for manual inspection.
Abstract:
Method for mold clamping of the present invention is capable of shortening a molding cycle without any initial setting works for an engaging position of a tie bars. The method is constituted the steps of moving the tie bars in the direction of mold closing during mold close operation, judging a relative moving speed between a movable die plate and the tie bar to be within a predetermined value, engaging the tie bars with the movable die plate mechanically by operating an engaging means when the relative moving speed is judged to be within the value, then further moving the movable die plate against a fixed die plate under engagement, and after contact of a movable mold with a fixed mold driving a mold clamping cylinder, thereby executing mold clamping operation.
Abstract:
An injection molding apparatus and method are provided in which the rate of material flow during an injection cycle is controlled. According to one preferred embodiment, an injection molding apparatus is provided that includes a manifold, at least one injection nozzle coupled to the manifold, an actuator, and a valve pin adapted to reciprocate through the manifold and the injection nozzle. The valve pin has a first end coupled to the actuator, a second end that closes the gate in a forward position, and a control surface intermediate said first and second ends for adjusting the rate of material flow during an injection cycle. Retracting the valve pin tends to decrease the rate of material flow during the injection cycle and displacing the valve pin toward the gate tends to increase the rate of material flow during the injection cycle.
Abstract:
A system and method are provided in which the rate of material flow to a plurality of gates can be controlled by a single controller. According to one embodiment, material is provided to first and second runners, the first runner comprising a plurality of distribution nozzles, and the flow to the first runner being controllable independently of the flow to the second runner.
Abstract:
A method of controlling operation of an injection molding system in which at least one injection molding device successively executes an injection molding operation thereof so as to successively produce the molded product, and at least one takeout device successively takes out the molded product from the corresponding injection molding device so as to successively transfer the molded product to a subsequent-step part in which the molded product is further processed, while a monitoring device is arranged for detecting an abnormal operation in the subsequent-step part and generating an abnormal signal upon detection of the abnormal signal, the method comprising the steps of: changing an operation mode of the at least one of takeout device so as to transfer the molded disk to another part which is separate from the subsequent-step part, upon generation of the abnormal signal by the monitoring device; and extending a cycle time of the injection molding operation of the at least one injection molding device upon generation of the abnormal signal by the monitoring device.
Abstract:
An injection molding method comprises the steps of melting molten resin within a heating cylinder, advancing an injection screw within the heating cylinder to inject the molten resin into a mold, retracting the injection screw to a predetermined position before completion of the injection, further advancing the injection screw under pressure control.
Abstract:
In a position control apparatus, the rate and the torque of the servomotor are monitored, wherein when it is detected that the servomotor is locked, the torque is limited, so that renewal of a command position to be supplied to the servomotor driving unit is stopped.
Abstract:
In the proposed method of molding toothbrushes, a mold with relatively movable mold parts (14, 16) defining at least one molding cavity (20) corresponding in shape to a toothbrush body is used. One of the mold parts (16) has a brush head defining cavity portion with a plurality of holes (24) for partial penetration into the cavity portion of a like number of fiber tufts. Plasticized molding material is injected under pressure into the cavity (20). Pressure within the cavity is sensed during the injecting step. The injection is stopped when the pressure within the cavity exceeds a predetermined pressure value, thereby avoiding any leakage of molding material through the holes (24).