Abstract: A mold clamping control method capable of preventing any warp or strain on a molded product without stopping an injection pressure holding process so as to cancel the pressing force of an injection screw. In a series of injection and pressure holding processes, a movable platen is retracted from a mold clamping dwell position P2 to a mold opening dwell position P1, so that a substantial volume of a cavity of a mold is increased to temporarily lower the internal pressure of the cavity, thus making an internal stress of resin to be a product uniform to eliminate stress strains. In this method, an injection molding is performed to produce a precise product having no warp or strain even in molding a light guide plate which is subjected to molding abnormalities by the temporary stoppage of the injection pressure holding process according to the conventional method.

Abstract: A temperature control method for an injection molding machine capable of performing stable temperature control at all times irrespective of the heat capacity of an object of temperature control. A temperature of an object of temperature control, such as a heating region of an injection cylinder, an injection nozzle and a mold, is detected by a respective temperature sensor G1-Gn. A feedback control of temperature is performed by a servo CPU (24) so that the detected temperature coincides with a set temperature, to obtain an electric current command value. Further, an actual electric current flowing in each of heaters H1-Hn is detected, and a feedback control of electric current is performed so that the actual current coincides with the current command value obtained by the temperature feedback control.

Abstract: A wire electric discharge machining method capable of improving a machining accuracy of a corner portion. A machining feed speed is gradually reduced from a point A before entering a corner portion machining between points C and D, and in the corner portion between points C and D the machining is performed at a fixed feed speed. The feed speed is gradually increased from the point D, where the machining of the corner portion is completed, and is restored to the original speed. In accordance with the change of the feed speed, an off-state time of the voltage applied between a wire and a workpiece is increased from a point B and is reduced from a point E after completing the corner portion machining, to restore the original off-state time at a point F. Further, a flow rate of machining fluid is reduced depending on the corner portion. The feed speed, the off-state time and the flow rate of the machining fluid are controlled by automatically changing them in dependence on a curvature of the corner portion.

Abstract: An ejector mechanism is driven by a servomotor. An ejector pin in the ejector mechanism is made to perform a motion such that the ejector pin reaches a predetermined protrusion limit position beyond a position where the removal of a molded product from a cavity or core is completed after making a check for positioning, and a plurality of cycles of reciprocating motion of a short amplitude such that the ejector pin neither retracts beyond a position where the removal of the molded product from the cavity or core is started nor protrudes to the protrusion limit position, without requiring a check for positioning.

Abstract: A programmable logic controller capable of freely and sequentially controlling peripheral equipment without modifying a system program. Necessary data for sequence control of the peripheral equipment are selected from data defined in the system program. The memory addresses corresponding to the data are assigned to addresses to be used in a user program in an address storage unit. The controller executes the system program to sequentially control an industrial machine, and also executes the user program to control the peripheral equipment. The controller refers to the data being used in executing the system program, which are necessary for sequence control of the peripheral equipment, based on the designated relationship of the addresses stored in the address storage unit.

Abstract: In an injection molding machine which performs movement control such that the rotation and axial movement of a screw (1) in a cylinder (10) are controlled in accordance with set injection molding conditions and executes an injection process for injecting a plasticized resin, for use as an injection object, into a mold (12), an injection molding condition setting method for the injection molding machine comprises: information detection process for detecting information on a time-based pressure acting on the resin in the injection process by means of injection pressure sensors (4, 13, 14), etc.

Abstract: An average is obtained between output readings of a pressure sensor obtained when forward and reverse thrusts are applied to an injection screw by positively driving a servomotor for injection. The average value is used as a correction value for a reading deviation of the pressure sensor. The injection servomotor is positively driven to apply a thrust to the screw. This known thrust and the actual reading of the sensor are compared. A deviation between these values is used as the correction value for the reading deviation of the sensor.

Abstract: An injection pressure monitoring method in which the correlations between a screw position, injection pressure, and cavity fill for an injection molding machine are monitored and displayed on a screen. The pressure for the position of a screw is graphically displayed on the screen, and a picture of a cavity is also displayed on the screen. By inputting the screw position, the pressure for the screw position is monitored, and at the same time, the resin filling state in the cavity corresponding to this screw position is displayed as an image.

Abstract: An operating time analyzing apparatus capable of automatically determining, storing, and analyzing the operating time of an injection molding machine for each operating condition. This apparatus detects the operating conditions of the injection molding machine through internal processing with a PMCCPU 14 for the sequence control of the injection molding machine. While specific operating conditions are detected, fine times .DELTA.t, execution cycles of the internal processing, are added in succession. By doing this, integrated time for each operating condition, that is, operating time for each operating condition, is calculated. This operating time is stored in a nonvolatile RAM 8 for each operating condition of the injection molding machine through the processing by the PMCCPU 14.

Abstract: An injection shaft of an electrically operated injection molding machine is entirely controlled based on its positions. In the injection process, an injection speed is changed over in accordance with a screw position for the processing at the injection process. In the subsequent dwell process, the screw is axially driven by a servomotor, a pressure applied to the resin is detected, and a difference between the pressure and a dwell pressure which has been set is found. The amount of movement in response to the difference is output to the servomotor for the drive thereof so as to keep the screw at the position. As a result, the dwell pressure is controlled by the screw position. Moreover, also in the metering process, the resin pressure is detected, and the screw is moved according to a difference between a set back pressure and a detected resin pressure so as to correspond with the back pressure which has been set.

Abstract: A monitoring method capable of properly collectively managing the operating states and operation records of a group of injection molding machines. Monitor data sets delivered from the individual injection molding machines are cyclically detected by means of a processor of a monitor unit, and a plurality of sets of up-to-date monitor data for the individual injection molding machines are renewably loaded into a plurality of data tables. When the preset time of a timer associated with any one of the injection molding machines is up, or when the current injection frequency reaches a predetermined frequency, it is concluded that the monitor data output timing is reached, and whether the monitor data should be printed or displayed on a screen is further determined.

Abstract: A method and an apparatus for monitoring injection pressure, using the relationship between positions of a screw (1), filling of resin in a cavity and injection pressure. Mold cavity data are stored, whereby a display screen (2) displays, based on said data, a configuration of the cavity and straight lines corresponding to cross sections along which the cavity is divided into a plurality of regions. Screw positions required to sequentially fill the divided regions of the cavity with the resin are obtained to be displayed on a coordinate axis representing a screw position in a pressure waveform graph (22). Then an operator changes the setting of molding conditions referring to the data on the display screen, and carries out the injection to obtain the pressure data corresponding to the screw position to be displayed on the pressure waveform graph (22).

Abstract: A product acceptance/rejection judgment method which always ensures accurate judgment whether a product is acceptable or not even when an injection molding machine is operated in different operating environments is implemented by a processor (22) of a numerically controlled device (20). When the processor determines that it should perform, in addition to a normal product acceptance/rejection judgment based on molding process parameters, an auxiliary product acceptance/rejection judgment based on at least one operating parameter which directly indicates an injection molding machine operating environment characteristic involved in the acceptance/rejection judgment of the product, the processor reads output data from an A-D converter (11, 12 or 13) which data corresponds to the actual value of at least one operating parameter detected by an appropriate die temperature sensor (8), open air temperature sensor (9) or a wind velocity sensor (10).

Abstract: A positioning correction method for a motor-operated injection molding machine, intended to eliminate waste of power supply to or overheat of servomotors by locking up in an ideal state the motor-operated injection molding machine, which uses a toggle mechanism or crank for mold clamping and other operations. During the lockup period, a load RA acting on a mold clamping servomotor 7 is detected (S8), and a position command value PM for the servomotor 7 is increased or decreased in the next cycle in a direction such that the value of the load RA is reduced, if the value of the load RA is greater than a preset reference value V0 (S12, S13). As a result, a rotation center Q1 of a crank 2 and two opposite ends Q2 of a link 3 are locked up in a straight line, so that a moment of rotation produced by a mold clamping reaction force is removed from the rotation center Q1 of the crank 2.

Abstract: An injection molding condition setting method capable of setting optimum molding conditions quickly and easily. A processor (12) of a control device furnished with an expert system, which includes a state table containing a plurality of states each composed of a combination of mold information, resin data, molding conditions, molding defect data, and molding monitor data, and a weight table listing weighted countermeasures against defect molding set for every state, retrieves a state nearest to a trial injection state, which is discriminated in accordance with the mold information, resin data, and molding conditions set before the start of trial injection, the molding monitor data detected during the execution of the trial injection and the molding defect data inputted after the end of the trial injection, from the state table, and determines a molding defect countermeasure corresponding to the retrieved state and having the maximum weight with reference to a weight table.

Abstract: An article conformity discriminating apparatus for an injection molding machine is capable of automatically discriminating the conformity of articles with accuracy without using a conforming article sample. In molding cycles for mass production of articles executed according to optimum molding conditions of a mold file read from a shared memory (105), an actual resin pressure detected by a pressure sensor (4) is periodically sampled according to an output of an address generator (118), while a reference resin pressure sampled in the same sampling period or a corresponding sampling period on a pressure transition pattern, in a conforming article molding process for determining the optimum molding conditions made before the mass production of the articles, is read from the shared memory, (105) by a processor (114), and the actual resin pressure is compared with the reference resin pressure.

Abstract: A discrimination method for maintenance timing for injection molding machines, detects the respective values of molding process parameters of a plurality of types, including injection time, maximum injection pressure, etc., for each of the injection molding machines (7-1 to 7-M). Up-to-date process parameter values for the molding machine are entered as a set of monitor data in a molding monitor unit (1) every time a predetermined number of molding cycles are executed in each molding machine. A plurality of monitor data values for each type are read, on a time-series basis, from a memory (4) loaded with a plurality of sets of up-to-date monitor data values associated with each molding machine, by means of a microprocessor (2), and dot-line data are generated.

Abstract: A method of monitoring a resin position intended to automatically display the relationship between the state of resin injected into the cavity and the screw position for monitoring. In the cavity, border sections where flow resistance of the injected changes are determined. Subsequently, a volume is found for each of the regions partitioned by the border, and the obtained volume is set into the control unit of the injection molding machine. The control unit displays the injection completion position when the amount of cushion Lc is inputted (200, 201). Moreover, the amount of a screw stroke Sj is determined on the basis of the volume determined for each of the positions having different flow resistance, and a screw diameter. Each amount of the screw stroke Sj is added to the amount of cushion Lc in sequence to find screw positions, which are to be displayed as injection speed changeover positions (203).

Abstract: A method for taking countermeasures against faulty molding in which, with the aid of an expert system, restoration to a nondefective molding condition when faulty molding takes place during the mass production of molded products. When threshold values of a plurality of molding parameters, and information indicative of countermeasure processes, respectively corresponding to combinations of evaluations on these parameters and determined on the basis of the knowledge and experiences of skilled persons, are manually entered through a data input device (119), they are stored in tables of a memory (110) beforehand under the control of a processor (114). Upon start of the mass production, the injection time, metering time and cushion amount which are measured or calculated during a molding cycle, and the resin pressures corresponding to the manually set screw positions at the time of passing the gate and filling are set in the tables as reference values of the parameters.

Abstract: A group management system for injection molding machines, capable of rapidly determining molding conditions of a plurality of injection molding machines. Data is supplied through first to eleventh input devices (13a-33c), which indicates types of molding defects appearing in molded articles respectively produced under tentative molding conditions by first to eleventh injection molding machines (12a-32c) which form first to third injection molding machine groups (12, 22, 32). First to third work stations connected to the first to third injection molding machine groups (12, 22, 32) determine one or more molding conditions to be modified and the amount of each modification, with respect to the individual first to eleventh injection molding machines, by using a multi-user operating system, and program and database for molding condition determination.