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 injection molding machine of an automatic core change type includes a mold clamping section including stationary and movable platens fitted with first and second matrixes of a mold, respectively, a mold changing robot and a mold stocker severally attached to the mold clamping section and separately controlled by way of a control section, and a temperature controller for controlling the respective temperatures of the first and second matrixes and the mold stocker. As an arm and a chuck move and rotate, respectively, a first cavity unit, attached to the first matrix, is taken out from the first matrix, transported toward the mold stocker, and stored in its corresponding storage hole of the mold stocker. Then, another first cavity unit is taken out from the mold stocker, transported toward the mold clamping section, and attached to the first matrix, whereupon the replacement of the first cavity unit is completed. A second cavity unit is replaced in like manner, whereupon the mold replacement is completed.

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 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 low cost crank operated injection apparatus is capable of driving an injection screw with a desired driving force without the need of employing a high output type electric motor. The injection apparatus includes a crank mechanism for converting forward and reverse rotation of a driving shaft into reciprocating motion of an injection screw mounted on a pusher plate. The driving shaft is coupled through a reduction gearing unit to the power output shaft of a servomotor controlled by a numerical control device, and the apparatus operates, during the injection process, so as to cause the injection screw to move forwardly with a great driving force.

Abstract: A crank mold clamping apparatus capable of variably adjusting a mold-opening stroke for permitting usage of various types of molds which includes a numerical control apparatus for controlling a servomotor for driving a crank plate connected to a movable platen in forward and reverse rotation within a limited rotation region. The numerical control apparatus calculates a rotation angle between rotational positions of the crank plate corresponding to mold clamping and mold-opening end positions of the movable plate, respectively, so that the crank plate is rotated for the calculated rotation angle in the direction of mold-opening or mold-closing to perform mold-opening or mold-closing when a mold-opening stroke, determined in accordance with the size of a mold to be used, is supplied.

Abstract: A molding condition recording apparatus having a manual data input device with a CRT. The manual data input device has various keys for inputting parameters of various groups used for controlling injection, hold, metering and cylinder temperature, and for inputting molding defect indication data. A microprocessor for a programmable machine controller causes the input parameters and the molding defect indication data to be stored in a molding condition storage region of a shared memory (S5). The microprocessor then discriminates similarity between the thus stored molding condition and the molding condition already registered in a molding condition/molding defect storage file of a memory other than the shared memory (S7). If there is similarity between these molding conditions, the microprocessor causes the CRT to display an alarm message thereon together with the parameter already registered in the file and the mold defect indication data (S12).

Abstract: A mold clamping apparatus is provided, including upper and lower toggle sections disposed symmetrically with respect to an axis of the apparatus, each toggle section including a ball screw disposed radially outwardly of the apparatus with respect to the axis, a head threadedly engaged therewith, and links operable to expand and bend with reciprocal head motion along the ball screw, each ball screw being directly coupled to a corresponding one of two servomotors connected to a control circuit section including a pulse width modulation control circuit and two transistor inverters. The mold clamping apparatus has primarily structural components separated from the axis so that flexure of the toggle mechanisms and resultant non-uniformity of a pressing force onto the movable platen are eliminated, and each servomotor is small enough to drive a corresponding one toggle section, so that the resultant mold clamp apparatus is low in cost and high in operational response.

Abstract: A drive system abnormality detecting apparatus of an injection-molding machine includes a microprocessor (19) for a controller, which causes a display unit (24) to indicate the occurrence of an abnormal situation. The drive of a servomotor (5) for an injection is stopped when the microprocessor concludes that the difference between the driving current of the servomotor and the output of a force detector, indicative of the resin pressure inside a cylinder (2), is not within predetermined permissible limits. The motor driving current and the detector output are individually periodically detected, during the time interval between the start of injection to the end of metering. By doing th is, the microprocessor prevents production of defective moldings, attributable to the occurrence of an abnormal situation in a screw drive system, and damage to components of the screw drive system and dies.

Abstract: A motor-operated, direct-pressure type mold clamping apparatus is capable of high-speed mold closing and opening operations and of producing a required mold clamping force, without the use of a large-sized motor. In the mold opening and closing operations, a ball screw, in engagement with a ball nut which is movable in one with a moving platen, is rotated at high speed by a motor through gears and a clutch, so that a die is opened and closed at high speed. In a mold clamping operation, the ball screw is driven with a large rotatory force transmitted through a clutch and gears which, having a high reduction ratio, serve to increase the rotatory force of the motor. Thus, dies are clamped with a large clamping force.

Abstract: During a mold thickness adjustment process of an injection molding machine, a mold touch position at which the mold halves of a mold contact each other is detected, and the mold temperature is detected by means of thermocouples attached to the mold halves, respectively. Also, the mold thickness is obtained based on the position where a movable platen and a stationary platen of the injection molding machine contact each other, which is obtained previously, and the detected mold touch position.After a molding operation is started, the mold temperature (Tn1, Tn2) is detected in each of molding cycles, and the amount of change of the mold thickness (.DELTA.e) during the period between the preceding cycle and the current cycle is calculated (S14) based on the change of mold tempreature (.DELTA.T) during the period between the two cycles, the mold thickness (e), and the thermal expansion coefficient (k). The mold touch position for the current cycle (P) is obtained (S16) based on the calculated value.

Abstract: A motor-operated, direct-pressure type mold clamping mechanism capable of high-speed mold closing and opening operations and of producing a required mold clamping force, without the use of a large-sized motor. In the mold opening and closing operations, a ball screw, in engagement with a ball nut which is movable in unison with a moving platen, is rotated at high speed by a coarse-adjustment motor through gears, so that a die is opened and closed at high speed. In the mold clamping operation, the ball screw is driven by a fine-adjustment motor through a clutch and gears which, having a high reduction ratio, serve to enhance the rotatory force and provide greater clamping force.

Abstract: A compressor unit of an injection-compression molding machine having a movable platen and a stationary platen. The compressor unit includes a compression pin (32) fixed to the end of a ball screw (29) threadedly engaged with a ball nut (24) which is coupled, by means of a power transmission mechanism (35), to a servomotor (19) attached to the movable platen (3). As the servomotor rotates, the compression pin moves axially together with the ball screw relative to the movable platen to project through the movable platen toward a mold clamped between the platens to cause molten resin filling the mold to be compressed.

Abstract: An injection molding machine using a linear motion type electric motor (10, 20), as a drive source, is provided, which is simple and compact in construction. The linear motion type electric motor includes a non-magnetic shaft (21) on which yokes (22) and permanent magnets (23) are alternately fitted, and an annular stator (10) having an outer tube (11) within which cores (12) and printed type coils (13-18) are alternately disposed, the shaft extending through the stator. Upon supply of three-phase alternating currect to the coils, a screw of the injection molding machine coupled to the shaft is moved in unison with the shaft to thereby perform injection operation.

Abstract: A product ejector in a motor-driven, direct-acting type hydraulic mold clamping system, which includes a rod mounted on a ball screw for driving a moving platen at a forward end of the screw on the side of the platen, so that the rod is immovable axially and engageable with and disengageable from an ejector plate attached to an ejector bar slidably arranged within a bore in the platen. When the platen moves rearwardly, the ejector plate, moving together with the platen, is abutted against the rod. As the platen moves farther rearwardly, the rod causes the ejector bar to project into a mold mounted to the platen, against the force of a spring inteposed between the ejector plate and the platen, to eject a molded article.

Abstract: A mold clamping apparatus having a plurality of servomotors for drivingly rotating a ball screw as a spindle. A driven timing gear pulley is mounted on a ball nut threadedly engaged with the ball screw whereby the pulley is rotatable integrally with the nut, and driving timing gear pulleys are fixed to output shafts of the respective motors. A timing belt is wound between the driven and driving pulleys. The servomotors are driven so as to produce the same torque by means of driving circuits which respond to the same torque command generated in accordance with a signal representative of a rotational position of one of the servomotors.

Abstract: There is provided a direct mold clamping apparatus with an ejector, which is capable of uniformly applying a mold clamping force to a movable platen and is simple in construction and compact in size. A hollow cylindrical push member (12) and a movable platen (3) are coupled to each other through a single junction plane, in the form of an annular ring. A driving force transmitted through the push member is applied uniformly to the movable platen. The ejector (1) of the mold clamping apparatus (2) is provided with a ball nut (7) disposed in a hollow portion of the push member. A ball screw (6), which mates with the nut, is coaxial with a ball screw (8) for mold clamping, and has a front end fixed to an ejector pin (4) and the rear end portion removably fitted in a hole (8a) in a front end portion of the mold clamping ball screw. Thus, the axial length of the mold clamping apparatus is reduced.

Abstract: A method of mold opening/closing speed control wherein an opening/closing speed switching position for molds in a mold clamping unit in an injection molding apparatus can be taught by a control device. The control device is set in a teaching mode (101), a servo motor (M) is driven at a low speed to move (102) the molds, speed switching position P1, P2 and P3 are stored (103, 104, 205, 106, 109) by a teaching device and opening/closing speed control of the molds is performed (110, 123) by the servo motor in accordance with the stored positions.

Abstract: Molds are mounted on a front platen and a moving platen. A plurality of ball screws are mounted between the front platen and the rear platen at equal distances from centers of the molds and at predetermined angular intervals. Ball nuts threadedly engaged with the plurality of ball screws, respectively, are mounted on the moving platen. A servo motor drives to move the moving platen in the axial direction of the ball screws through the ball screws and the ball nuts. A mold clamping force is generated by a stress occurring in the ball screws when the molds are closed.

Abstract: An automatic die exchanger for an injection molding machine is provided, having a rotational table and a travel member capable of approaching and separating from a die mounting section of the injection molding machine. A convey means provided on the travel member is engaged with and disengaged from one of the dies on a plurality of die placing sections of the rotational table. When the travel member is moved, the convey means feeds the die engaged therewith to the die mounting section or removes a die therefrom.