Abstract: A disturbance estimating observer is provided, which estimates a load applied to a servomotor for driving an ejector axis. When an ejector operates, the disturbance load torque estimated by the observer is sampled for each specific period (0 to j), and the data DA (0, 0) to DA (i, j) of (i+1) ejector processes are stored in a table TA in the form of cyclic storage. From this table TA, average values DB (0) to DB (j) of estimated disturbance load torques are determined in turn and they are stored in a table TB. From these average values, upper limit values DC (0) to DC (j) and lower limit values DD (0) to DD (j) of a permissible range are stored in tables TC, TD. When the determined estimated disturbance load torque has exceeded the permissible range, an abnormal load signal is outputted.

Abstract: An information transmitting system for use in a factory, which is capable of transmitting information among controllers simply without the complicated lead-around of a communication line nor the need of complicated communication protocol. A controller for every molding cell Ai, where i=1,2 . . . max and max is a maximum number of molding cells, a conveyance controller to control an automatic conveyor, a stock cell and a centralized controller are connected to each other via an Ethernet line to provide a common information storage unit, and information is transmitted among the controllers through the common information storage unit. Since there is no need of parallel communication lines between the controllers, an I/O port or a communication line may be prevented from increasing in number and the lead-around of the communication line is prevented from being complicated, resulting in a reduction of cost required for setting up the devices.

Abstract: A method of and a device for collecting knowledge of an injection molding technique capable of collecting knowledge of an injection molding technique from a number of expert engineers without a knowledge engineer and also collecting machine operation data obtained in performing an injection molding operation in accordance with the knowledge of the injection molding technique. A plurality of injection molding machines are connected to a server computer through a network such as LAN. A predetermined rule for collecting an expert engineer's knowledge of the injection molding technique is stored to be executable in the server computer. Each of the injection molding machines is provided with an input device for allowing an operator to input data utilizing the predetermined rule. When a problem such as a molding defect occurs in an injection molding machine, an expert engineer takes countermeasure such as modification of set values of molding conditions against the molding defect.

Abstract: A method of and an apparatus for measuring and evaluating characteristics of material resin using an injection molding machine. Injections of resin are performed with different resin temperatures TCi and different injection velocities Vj to detect injection pressures Pr at set screw positions. Data of combinations (Pr, V, TC) of an N number of injection pressures, injection velocities and resin temperatures are obtained. An interdependency relation function Pvr(t, v(x),x) expressing correlation among the injection pressure, the injection velocity and the resin temperature is obtained as Pvr(t, v(x), x)=A(x)e−&agr;(x)Tv(x)&bgr;(x) according to a least square method using the obtained data, where &bgr;(x) represents a degree of dependency on injection velocity influencing the injection pressure and “log A(x)−&agr;(x)T” represents a degree of dependency on resin temperature influencing the injection pressure.

Abstract: The position of a feed shaft is monitored, the mean moving speed and moving frequency of the feed shaft are measured with every unit time for position correction, and a correction amount &dgr;n is determined from the speed and frequency according to an approximation formula and updated (c7 and c8). A position correction amount for a commanded position is determined from this correction amount, and the commanded position is corrected by the position correction amount (c1 to c6). The position correction amount for the commanded position is determined from this correction amount, and the commanded position is corrected by this position correction amount. Since the correction amount is determined according to the approximation formula, thermal displacement correction can be effected at all times without requiring any sensor.

Abstract: A resin flow analysis in a die is performed by CAE or the like to obtain a resin pressure curve at a resin inlet port or a resin pressure curve at a nozzle end portion of a molding machine. Injection (air shot) is performed while a nozzle is separated from a die, so that an injection pressure curve Pa to be detected at this time is obtained. From the injection pressure curve and the resin pressure curve, an injection pressure command curve serving as a molding condition in mass production is obtained. The resin pressure curve obtained by the resin flow analysis is compensated by the injection pressure curve in an air shot for a time lag and pressure loss caused by the mechanical elements of an injection molding machine, so that molding conditions in mass production can be easily obtained. In addition, a pressure loss at the nozzle portion is also obtained, so that an injection pressure command curve is obtained from the pressure loss, the injection pressure curve, and the resin pressure curve.

Abstract: A mold protection device for an injection molding machine capable of automatically setting a reference value for detecting an abnormal load exerted on a mold in a mold closing process. A load exerted on a servomotor for driving a mold clamping mechanism is estimated by a disturbance estimating observer provided in a control system of the servomotor. The estimated disturbance torque is sampled at every predetermined period in a mold protection region and cyclically stored in a table TA as data DA (0, 0) to (i, j) in mold closing processes of the number (i+1). A predetermined amount is added to an average value of data DA (0, n) to (i, n) to define an upper limit DC(n) for the disturbance torque and stored in the table TC. If the estimated disturbance torque at each sampling period exceeds the upper limit DC(n) of in the mold protection region in a present mold closing process, an alarm is issued to indicate abnormal load.

Abstract: An information transmitting system for use in a factory, which is capable of transmitting information among controllers simply without the complicated lead-around of a communication line nor the need of complicated communication protocol. A controller every molding cell Ai, a conveyance controller C to control an automatic conveyance means D and a stock cell C and a centralized controller B are connected to each other via an Ethernet line (100) to provide a common information storage means (107), and information is transmitted among the controllers through the common information storage means (107). Since there is no need of parallel communication lines between the controllers, an I/O port or a communication line may be prevented from increasing in number and the lead-around of the communication line is prevented from being complicated, resulting in a reduction of cost required for setting up the devices.

Abstract: A method of and an apparatus for precisely determining a separating force of a molded product from a mold by an ejector in an injection molding machine. A load exerted on an ejector mechanism in operation without a product molded in the mold is constituted by an inner resistance of the ejector mechanism. The inner resistance includes frictional force produced within the ejector mechanism and resilient forces of springs for returning ejector pins to retracted positions thereof. On the other hand, the load exerted on the ejector mechanism in operation with a product molded in the mold is constituted by the inner resistance and the separating force of the molded product from the mold. Thus, a difference between the loads detected in driving the ejector mechanism with and without a molded product at each ejector position precisely represents the separating force of the molded product from the mold.

Abstract: A metering controller capable of making a metering time constant and kneading of resin uniform. A screw torque STRQ(n) is detected and stored at every processing period from a start of metering as reference data. A screw rotational speed command is changed over to a set value at each predetermined changeover position. A present screw torque is detected and subtracted from a corresponding screw torque STRQ(n) of the reference data to obtain a deviation &Dgr;TRQ. A correction amount SROT for the screw rotational speed command is obtained based on the deviation &Dgr;TRQ. The correction amount SROT is added to the set screw rotational speed command SRCMD and thus corrected command is outputted for controlling a servomotor for rotating the screw. A screw retracting speed and a screw retracting position may be adopted as reference data. Since a transition pattern of the screw retracting motion coincides with that in obtaining the reference data, the metering time is made constant.

Abstract: A device and a method for detecting condition of molds attached to an injection molding machine with low cost and high reliability. A load exerted on a product ejecting mechanism or a mold opening/closing mechanism is estimated by a disturbance torque estimating observer. An index value (maximum value or average value) of the load is obtained and stored in each molding cycle of the injection molding machine. Obtained values of the index are 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.

Abstract: A data display/input method for a CNC apparatus without necessity of using a personal computer which has been served as a relaying device between the CNC apparatus and a host computer and also as a display device, and also capable of constructing an FA network system at low cost. A display screen of the CNC apparatus is split into first and second display areas so that information transferred from the host computer to the CNC apparatus is displayed in the first display area while information inputted to the CNC apparatus by the operator is displayed in the second display area. Display attributes in the CNC apparatus are switched in accordance with display attributes specified by the information transferred to the CNC apparatus from the host computer, whereby restrictions on a data display of the CNC apparatus are removed, permitting text data and graphic data to be displayed.

Abstract: An injection is carried out under a certain molding condition with a nozzle in an injection molding machine left open to sample an injection pressure Pr in every certain cycle for storing. Detected pressure data Pr(0) to Pr(N) for one shot is stored as reference pressure data Pr0(0) to Pr0(N). When defective molding occurs or when a resin lot is changed or the like, the injection is carried out with the nozzle left open under the same molding condition as that used in obtaining the reference pressure data and obtain the detected pressure data Pr(0) to Pr(N). Waveforms of the detected pressure data Pr(0) to Pr(N) and reference pressure data Pr0(0) to Pr0(N) are graphically represented so that variation of the molding condition is observed. It is assumed that if there are any differences, a problem presumably resides in resin, while if there is no difference but the defective molding occurs, the problem presumably resides in a mold.

Abstract: A controller of a wire electric discharge machine monitoring a change in thickness of a workpiece and a current density in real time, promoting a machining speed by preventing occurrence of disconnection of a wire electrode even when the change in the thickness is caused in the workpiece and improving a dispersion in a machining enlargement amount. A machining distance calculating device outputs a signal at each progress of machining by a predetermined distance &Dgr;x. A main pulse number storing device counts a main pulse number for discharge machining outputted from a main pulse generator during a time period of the signal. A thickness calculating device calculates the thickness from a reference main pulse number in machining a reference thickness, the main pulse number stored to the main pulse number storing device and the reference thickness at each reception of the signal. The calculated thickness, further, a machining current, the machining speed and a machining current density are displayed.

Abstract: Actual machining positions P1, P2, . . . corresponding to command positions S1, S2, S3 . . . of each block of NC data are obtained by trial machining. Positions that correspond symmetrically to the actual machining positions P1, P2, . . . with respect to the command positions S1, S2, S3 . . . of each block are obtained. Modified NC data are created with use of the symmetrical positions as modified command positions for each block. The modified NC data include correction values for modifying positional differences attributable to a delay in a servo system. Therefore, if machining is carried out in accordance with the modified NC data, the correction values and a follow-up delay attributable to the actual delay in the servo system cancel one another, so that a high-accuracy work shape can be obtained.

Abstract: The correlation between an injection stage and an injection speed initially set in an injection condition file is graphically displayed on a display screen. A modification section is set by assigning a starting point and an end point on the graph. Then, the shape of a segment which connects the starting point and the end point is selected and assigned, out of those of a straight line and a circular arc. Thus, a section between the two points constitutes one new injection stage. In this new injection stage, moreover, the injection speed is not always a constant value, and can be optionally set so that it linearly increases or decreases or changes along a circular arc in this section.

Abstract: A method of collecting molding data and obtaining a molding condition releases an operator from test shot operations and improves operation efficiency. A rough molding condition obtained by a condition setting operation is modified with a pitch which is set for respective molding condition items and a plurality of analogous molding conditions are created and stored in a host computer. A set of the analogous molding conditions and the set number of test shots are transferred to a controller of an injection molding machine to continuously carry out the test shots. Molding data detected in the test shots are transferred to and stored in the host computer. An optimal molding condition is obtained by evaluating the molding data under the respective molding conditions.

Abstract: A zero point adjusting method and apparatus for a pressure detector of an injection molding machine, capable of carrying out a zero point adjustment of the pressure detector when external loads acting on the pressure detector are completely removed without disassembling an injection mechanism. An advance limit position Qf and a retreat limit position Qb of a screw are detected by driving the screw with a low output to determine an intermediate position Pm. By moving the screw to the intermediate position Pm, a resin reaction force acting directly on the screw is removed. Reciprocating motion in which an amplitude decreases gradually is imparted to the screw, thereby causing a backlash, having equal plays in the advance and retreat directions, between a ball nut and a ball screw. Then, the zero point adjustment of the pressure detector is made.

Abstract: Clamping and injection operations are executed partially in parallel by adjusting a clamping speed and an injection start timing T so that sum .SIGMA.P of resin pressure acting on the parting plane of a mold cavity will not exceed mold clamping force F outputted at that time. An injection operation is started during the period in which the mold clamping force F is relatively low between mold touch and mold clamping completion, so that gas breathing from the mold cavity can be done easily without providing gas vent in the mold, thereby preventing resin filling failure or burning. Also, the clamping and injection operations are executed partially in parallel, so that time required for clamping and injection processes is shortened by time T' as a whole. Therefore, speeding of molding cycle can be attained.

Abstract: A reference pressure waveform for injection molding operation is set in advance; pressures corresponding to the pressure waveform are detected with predetermined detection times during the injection molding operation; pressure deviations between pressure stored in the pressure waveform, corresponding to the detection times, and the detected pressures are obtained; and the pressure deviation for each detection time is graphically displayed on a display screen along with the reference pressure waveform.