Abstract: Detecting circuits are connected in parallel to respective on/off mechanical contacts or on/off semiconductor devices of a motor contactor and/or a brake contactor of a driving circuit supplying driving electric power from a three-phase alternating-current power supply circuit to a three-phase alternating-current electric motor and a brake through the motor contactor and the brake contactor, respectively. The detecting circuits output pulse signals synchronized with the alternating current from the alternating-current power supply circuit. A signal processing circuit processes the pulse signals from the detecting circuits and detects a normal or abnormal condition of each on/off mechanical contact or on/off semiconductor device of the motor contactor and/or the brake contactor.

Abstract: Detecting circuits 6a to 6e are connected in parallel to respective on/off mechanical contacts or on/off semiconductor devices of a motor contactor and/or a brake contactor of a driving circuit supplying driving electric power from a three-phase alternating-current power supply circuit to a three-phase alternating-current electric motor and a brake through the motor contactor and the brake contactor, respectively. The detecting circuits output pulse signals synchronized with the alternating current from the alternating-current power supply circuit. A signal processing circuit processes the pulse signals from the detecting circuits and detects a normal or abnormal condition of each on/off mechanical contact or on/off semiconductor device of the motor contactor and/or the brake contactor.

Abstract: A bottom dead center correction device for a servo press machine which can correct the bottom dead center with a high precision not achieved by a bottom dead center correction by a slide position detection device provided on a frame includes a bottom dead center sensor (11) and a temperature sensor (12) on a lower mold (10B) of a die (10). The bottom dead center of a set slide motion of slide (3) is corrected by the bottom dead center measurement value of bottom dead center detection sensor (11) and by the temperature drift of bottom dead center detection sensor (11) resulting from the temperature rise of die (10) due to molding and detected by temperature sensor (12). A bottom dead center correction of one micron unit not previously achieved becomes possible. The bottom dead center correction device also can be provided as one which corrects for the fluctuations in the bottom dead center resulting from deformations in all of the construction parts and the die of the servo press.

Abstract: A screw press which can ensure the positional precision of the ram when the rotation amount of the press motor does not directly translate into the position of the ram because there is other machinery, such as a decelerator and the like, present between the motor (servo motor) and the screw mechanism, has a construction in which a position detection sensor, which detects the position of the ram, is provided, and the position of the ram is controlled by the output from this sensor.

Abstract: Two sets of linear motors are fixed on opposed sides of a molding head driving device. Each linear motor includes a movable slider facing a casing. The linear motor contains a molding head and a magnetic plate facing a molding head. The use of two linear motors cancels out the magnetic attraction between the facing linear motors. A linear roller guide is disposed vertically in a direction perpendicular to the magnetic attraction between the linear motors so that the magnetic attraction from the linear motors does not act on the linear roller guide. In another embodiment, three sets of molding head driving devices are disposed between left and right frames integrally formed projecting from a base to form a molding device. In a further embodiment a pair of double linear motors drives four molding head driving devices. The double linear motors are affixed together by, for example, bolts.

Abstract: An ON-OFF control of a clutch-brake for a press machine, having fail-safe operation. The clutch-brake drive control is provided by turning double solenoid valves on and off. Two lines of drive control signal generators output drive control signals to semiconductor elements when a running command pulse signal is recognized as valid. A bus collating circuit forcibly cuts off AC power supplies of solenoid driving circuits when synchronization and coordination of the operation of each of the lines are checked and found not in coordination. Two lines of fault detecting circuitry forcibly cuts off the AC power supplies of the solenoid driving circuits by automatically detecting a fault of the semiconductor elements.

Abstract: A predetermined amount of melted thermoplastic resin of raw material is injected into a molding space which is previously set to a temperature higher than that at which the resin beings to harden under atmospheric pressure and which has a capacity larger than a volume of a product. The injected resin is cooled in the molding space and pressurized before the resin is cooled to the temperature at which the resin begins to harden under atmospheric pressure. When pressurized, the glass transition temperature of the thermoplastic resin is shifted to a higher temperature so that the thermoplastic resin hardens in slight reduction of the temperature. The resin is cooled in the pressurized state until the resin possesses the dynamic rigidity under room temperature and atmospheric pressure.

Abstract: A speed control device for stepping motor is disclosed which is possible to freely control the running speed of the stepping motor when driving it in closed loop. Its mechanism is designed to be possible to decide which excitation phase to be excited according to a phase difference between the output signals emitted from the encoder and the speed-variable reference clock signals and to make the running speed of stepping motor follow to the instruction of said reference clock signals.