Fanuc Corporation

Fujitsu Fanuc Limited

Asahi Glass Company, Limited

Naoto Ota

Yoshiki Fujioka

Yoshinori Kohzai

Hiroshi Ishida

Katsuo Kobari

Naoyuki Suzuki

Yuuichi Yamada

Mamoru Yaeshima

Yuji Kanamori

Susumu Saito

Hiroshi Yamamoto

Toshiyuki Tanaka

Tetsuji Shimohira

Shinichi Kono

Mitsuhiko Hirota

Nobuyuki Kasahara

Takashi Harada

Masakuni Sato

Yoshinobu Takano

To provide a plastic optical fiber using amorphous fluorinated polymers whereby transmission loss and bending loss are low, no cracking takes place during stretching, and a wide range of molding conditions is acceptable. A plastic optical fiber comprising an inner layer, an outer layer having a refractive index lower than the refractive index of the inner layer, and a protective coating layer covering the outer periphery of the outer layer, wherein the inner layer contains an amorphous fluorinated polymer (a) having no C&#x2014;H bond, the outer layer contains an amorphous fluorinated polymer (c) which may have a C&#x2014;H bond only at a terminal of the main chain, the glass transition temperature (Tgc) of the fluorinated polymer (c) is at least the glass transition temperature (Tga) of the fluorinated polymer (a), the plastic optical fiber is a stretched one, the fracture elongation of the fluorinated polymer (a) and the fracture elongation of the fluorinated polymer (c) are at least 120% and larger than the stretching ratio.

Plastic optical fiber and method for its production

The present invention is directed to the provision of a servomotor driving apparatus that feeds energy stored in a power storage part connected with a DC link that connects a rectifier circuit with an inverter circuit so that the energy stored in the power storage part can be reduced. A motor driving apparatus () includes: a step-up type DC/DC converter circuit () for boosting voltage appearing at an output of the power storage part (C) connected with a DC link; and a DC/AC conversion circuit () for converting the boosted DC electric power into AC electric power and feeding it to an electric power source.

Motor driving apparatus

While the motor drive amplifier is not operating, electromagnetic switch contacts are held closed for a predetermined period of time, three-phase power is rectified by a rectifier circuit and a smoothing capacitor is charged. Then, the smoothing capacitor is discharged through a discharging resistor and, when a predetermined voltage is reached, a contact is closed, with the result that a closed circuit is formed by the smoothing capacitor, a detection resistor, a motor coil, motor insulation resistance, and ground. A voltage generating across the detection resistor due to leakage current is detected and compared with a reference value. If the detected voltage exceeds the reference value, an insulation degradation signal is delivered.

Motor driver

Drive motor control unit

Terminal for connecting electronic components

Switching regulator having parallel diode isolated primary windings and

Position loop gain control method

Position control apparatus

Speed detecting apparatus

Induction motor drive apparatus

System for stopping spindle at commanded position

A speed control circuit and position control circuit are connected to a spindle drive motor in a machine tool or the like in order to drive the spindle at a predetermined speed and stop the spindle at a predetermined angular position. When an orientation command is issued while the spindle is being rotated at the predetermined speed by a speed control loop, a speed command signal from a speed command circuit is interrupted, the speed reduced to zero, and an initially set voltage is then employed as a speed command to rotate the spindle by a predetermined amount. Next, a integral value of the actual spindle speed is employed as the speed command to further rotate the spindle by a predetermined amount. When this has been accomplished, a constant bias voltage of a low level replaces the speed command, thereby to rotate the spindle still further by a predetermined amount until a specified portion of the spindle approaches extremely close to the predetermined angular position. At this point a signal, sensed by a magnetic body provided on the specified portion of the spindle and a sensing circuit confronting the magnetic body, is employed as the speed command signal of the speed control circuit, the sensed signal having a gradually decreasing waveform which attains a value of zero when the specified portion of the spindle is stopped at the predetermined angular position. Using this signal gradually decelerates the spindle motor to stop the spindle accurately at the desired angular position.

Spindle orientation control apparatus

A control circuit for driving an induction motor wherein an AC voltage is converted into a direct current by a rectifying circuit and the direct current is converted into a signal having a variable voltage and frequency by a transistor inverter connected in parallel with a smoothing capacitor, and a regenerative circuit is connected in parallel with the inverter, and a circuit is provided for comparing the terminal voltage V.sub.C of the smoothing capacitor and a reference voltage V.sub.r when braking is to take place is disclosed. When condition V.sub.C .gtoreq.V.sub.r exists, the transistor inverter is disabled but the regenerative circuit is allowed to operate; when the condition V.sub.C &lt;V.sub.r exists, the transistor inverter is operated in the regenerative braking mode.

Induction motor control system

A control circuit for stopping a spindle at a predetermined rotational position, of the type having a position sensor for producing a zero volt signal when a specified point on the spindle arrives at the predetermined rotational position, and for producing a voltage which is positive or negative when the specified point on the spindle is in the vicinity of the predetermined rotational position on either the left or right side thereof. The control circuit includes an orientation control circuit for stopping the spindle drive motor when the output signal from the position sensor attains the value of zero volts, thereby stopping the specified point on the spindle at the predetermined rotational position. The control circuit further includes a position adjustment circuit for adjusting the rotational position, of the specified point on the spindle, at which the output signal from the position sensor crosses the zero volt line. The position at which the specified point is stopped is adjusted by the position adjustment circuit, so that it is possible to correct an error in the stopping position which results from a position sensor mounting error.

Control system for stopping spindle at predetermined rotational position

A system for stopping a spindle, which is provided in a machine tool, in such a manner that a specified point on the spindle is stopped at a predetermined rotational position. The system includes device for detecting the direction of spindle rotation. When the spindle arrives at a region where it is to be controlled in order to stop at the predetermined rotational position, a position deviation signal is applied as the input signal of a speed control loop for controlling the rotation of the spindle. This signal turns the specified point on the spindle to the predetermined rotational position, in the same direction in which the spindle is rotating, on the basis of the direction signal from the detecting means. That is, the specified point on the spindle is rotated to the predetermined rotational position in a direction which is the same as the direction of rotation during tool operation.

Growing community of inventors

Hino, Japan

Naoto Ota