摘要:
If a screw (1) is moved forward after a metering step is completed, the screw (1) moves in a state where a check ring (3) on a tip end (2) of the screw (1) is in open state. Resin flows in a direction opposite to the injection direction. A rotational force is applied to the screw due to the backflow of the resin. If the check ring (3) closes a resin passage, the rotational force acting on the screw is reduced. A peak time of the screw rotational force is detected as closing point in time of the check ring (3). Physical amounts such as a screw rotational force and a screw position at that timing are detected. Since the closing point in time of the check ring (3) is precisely detected, correction of the injection/hold pressure switching position and the injection speed switching position can be adjusted more precisely. It is possible to precisely determine whether a molded article is non-defective or defective based on the detected physical amount.
摘要:
A controller for an injection molding machine capable of reducing an extension of a cycle time in a screw retreat process after the end of measurement, obtaining a more accurate and uniform measured resin amount, and determining measurement conditions in a short period of time. After the measurement is finished, the screw is stopped from rotating and retreated at a first speed V1. The screw is reversely rotated at a predetermined speed Rv in a set zone. As this is done, the screw is retreated at a second speed V2 lower than the first speed V1. After the reverse rotation zone is terminated, the screw is stopped from rotating and retreated at a third speed V3 to a set retreat stop position. By doing this, the cycle time can be made shorter than in the case where the retreat and reverse rotation of the screw are performed separately. Since the retreating speed of the screw is low while the screw is being reversely rotated, a sudden pressure change can be suppressed, so that precise measurement can be made. Since conditions for the reverse rotation and retreat of the screw can be regulated independently, they can be adjusted to optimum conditions in a short period of time.
摘要:
An injection screw position Xa, injection speed Va, and injection pressure Pa are read. A deceleration distance D the injection screw moves from the point where the injection operation has been stopped at the current moment to be decelerated by_maximum deceleration till the point where the injection speed is reduced to zero is determined from a corrected deceleration in which the amount of correction α is added to a predetermined deceleration A inherent in the machine and the read injection speed Va. The determined deceleration distance D is multiplied by the amount of change in injection pressure with respect to the amount of change in the injection screw position to determine a predicted increment in pressure (D·ΔP/ΔX). The predicted increment in pressure is added to the current injection pressure Pa to determine an injection pressure Pa* predicted when the screw is suddenly decelerated at the current moment. If the predicted injection pressure Pa* exceeds the predetermined limit pressure Pmax, the injection operation is stopped to decelerate the screw.
摘要:
The retraction of an injection screw is controlled on the basis of the pressure deviation between a set resin pressure and the detected resin pressure (T1-T4). Furthermore, the screw is caused to rotate at a set speed. Moreover, when the deviation between a metering completion position and the current screw retraction position drops to a value that is equal to or less than a set value, control of the retraction of the screw based on the pressure deviation is stopped (T5, T6), and the control is switched to positioning control based on the positional deviation (T7). Furthermore, a screw rotational speed command in which the pressure deviation component between the set resin pressure and the current resin pressure is corrected from the screw rotational speed component that is decelerated in proportion to the positional deviation is determined and output (T8-T13).
摘要:
A load determining device for an electrically-operated injection molding machine is provided, in which a load exerted on a movable part such as a molded product ejector (6) is detected based on the current of the ejector motor (M) or by an observer, whilst removing the influence of motor temperature. Upon start of continuous molding, a maximum load detected during retreat motion of the ejector (6) or other movable part is stored as a reference value Lr0. In every molding cycle, a maximum detected load Lra during the retraction of the ej ector (6) is determined. In the next molding cycle, load La detected during advance of the ejector (6) is corrected based on the reference value Lr0 and the maximum detected load Lra to eliminate the influence of motor temperature rise, thereby determining the load Lfx(n) during the advance of the ejector (6). When there occurs a change in temperature of the ejector driving motor (M), the load detected based on the motor current or by the observer varies even if the actual ejector load is constant. By eliminating the influence of temperature change, the load can accurately be detected.
摘要:
An electric servo motor (5) is controlled through a pressure control loop (1, 7) wherein a control object is the injection mechanism of an electric injection molding machine. A band elimination filter (10), which attenuates a frequency component of a band with predetermined width to be determined based on the resonance frequency of the control object, is provided in the pressure control loop (1, 7).
摘要:
The invention provides a device and a method for detecting condition of molds (m1, m2) attached to an injection molding machine with low cost and high reliability. A load exerted on a product ejecting mechanism (7) or a mold opening/closing mechanism (4, 5, m1, 6) is preferably estimated by a disturbance torque estimating observer. An index value (for example a maximum value or average value) of the load is obtained and stored preferably in each molding cycle of the injection molding machine. Obtained values of the index are suitably displayed as a graph on a display device to indicate variation of the load in time series and thus allow an operator to monitor the condition of the molds.