The Furukawa Electric Co., Ltd.

Mitsubishi Denki Kabushiki Kaisha

Mitsubishi Electric Corporation

Masanori Ozaki

Shoji Shiga

Tetsuaki Nagano

Keiji Mashimo

Fumio Kumazaki

Yoshiyuki Kobayashi

Tetsuya Tanabe

Hidetoshi Ikeda

Akira Tanabe

Kiyoshi Yamamoto

Toshiyuki Kaitani

Kei Terada

Yoshihiro Marushita

Masahiko Yoshida

Takeshi Nishizawa

Tsutomu Kazama

Isamu Ohishi

Yasushi Ikawa

Hideaki Kameoka

Takao Orimo

Norimasa Sato

Masanao Mimura

Nakahiro Harada

Takeshi Hirasawa

Tomiharu Okita

Osamu Kodachi

Gou Isobe

Shizuo Kumekawa

Yoshikazu Ohashi

Yasuzou Tanaka

Ton-Chi Chang

Masato Morita

Yositika Nagayama

Mikihiro Sugimori

Koutaro Tsuri

Provided is a motor control device which realizes automatic adjustment of control of a motor for driving a mechanical load through a simple operation. The motor control device includes: a follow-up control unit () for receiving detection information of a detector () to output a torque command signal and output a status of motor control of a motor () as a control status amount signal, when a command signal regarding the motor control to be output from an upper-level controller is absent; an oscillation detection unit () for receiving the control status amount signal and detecting oscillation of a control status amount to output an oscillation detection signal; and an automatic adjustment unit () for receiving the oscillation detection signal to monitor a control status of the motor () and adjust a control parameter of the follow-up control unit () only when abnormality is detected.

Motor control device

There is provided a controlling device for an AC motor having a structure in which a current of a three phase brushless DC motor is detected and then converted to a rotor coordinate system, to separately control a torque split current (q axis) and an exciting split current (d axis), wherein an offset is estimated with a DC component of a multiplied value of the values corresponding to a d axis voltage command which is an output of an exciting split current controller and an electrical angle, and the detected current is compensated for, so that an offset of a current detector may be estimated and compensated for during its operation without stopping its rotation and the motor can rotate smoothly without a torque ripple, even in the case in which the current detector has an offset error or in the case in which an offset changes due to a temperature drift.

Controller for AC motor

A heat exchanger tube for effecting a heat exchange between a fluid inside the heat exchanger tube and another fluid flowing outside the heat exchanger tube, which is provided with a first kind of spiral grooves and a second kind of spiral grooves, each being formed on an outer surface of the heat exchanger tube. The twisting direction of the first kind of spiral grooves in relative to the axis of the heat exchanger tube is the same as that of the second kind of spiral grooves but differs in helix angle from each other with helix angles of the first kind of spiral grooves and the second kind of spiral grooves falling within the range of 3.degree. to 80.degree. in relative to the axis of the heat exchanger tube.

Heat exchanger tube and method for manufacturing the same

In an encapsulated contact material which varies little in contact resistance and has good working life performance, at least one contact coating layer is formed covering the surface of a contact substrate. The contact coating layer includes a substantial matrix formed of at least one element selected from a group including Mo, Zr, Nb, Hf, Ta, and W, the matrix being loaded with 0.5 to 50 atom % of at least one element selected from a group including Zn, Cd, Hg, Al, Ga, In, Tl, Ge, Sn, Pb, As, Sb, and Bi. The contact coating layer has a thickness of 0.1 .mu.m or more.

Encapsulated contact material and a manufacturing method therefor, and a

A position controller includes: a compensation torque control circuit which outputs a second torque signal T.sub.2 * and an initial value of an integration torque T.sub.iset on the basis of a real speed signal .omega..sub.M, a rotation angle instruction signal .theta..sub.M *, a real rotation angle signal .theta..sub.M, an integration torque signal T.sub.i of a speed control circuit, and a reference .theta..sub.drp *; a speed control circuit which outputs a first torque signal T.sub.1 * and the integration output T.sub.i on the basis of a speed instruction signal .omega..sub.M * and the real speed signal .omega..sub.M ; an adder which adds the first torque signal T.sub.1 * to the second torque signal T.sub.2 * and outputs a torque instruction signal; and a torque control circuit which controls the torque of the motor in accordance with the torque instruction signal.

Position controller for an electric motor

Electric contact materials, production methods thereof and electric

A resistance welding process for aluminum and aluminum alloy materials for enabling the remarkable improvement of the electrode life comprises the steps of preparing an insert material having the overall thickness of 0.02 to 1 mm including a sheet-like core material consisting of iron, steel, copper or copper alloy and coated layers each having the thickness of 1 to 100 .mu.m, consisting of any one of Ni, Ni alloy, Ti, Ti alloy, Nb, Nb alloy, Mo, Mo alloy, W, W alloy, Cr, Cr alloy, Co and Co alloy and formed on both surfaces of the core material, or an insert material consisting of Ti foil or Ni foil; interposing the insert material between each of upper and under electrodes and each portion of overlapped materials to be welded consisting of aluminum or aluminum alloy; pressurizing the materials to be welded by the upper and under electrodes to join the materials to be welded together. The coated layers on both surfaces of the core material may consist of the same metal or different metals from each other. When the core material of the insert material consists of iron or steel, the insert material having the coated layer consisting of Ti and formed on one surface is interposed between each electrode and each portion of the materials to be welded in such a state that the coated layer faces each material to be welded, and the materials to be welded are pressurized and jointed together.

Resistance welding process for aluminum and aluminum alloy materials

The present invention provides inexpensive electric contact materials having higher hardness and higher melting point and being more excellent in the points of wear resistance and environmental resistance over the electric contact materials of Ag type, Au type, platinum group type, etc. having been used so far, production methods thereof and electric contacts used said contact materials. In the electric contact materials of the invention, basically, a covering layer having at least one selected from transition metals of groups IVa (Ti, Zr, Hf, etc.), Va (V, Nb, Ta, etc.) and VIa (Cr, Mo, W, etc.) as a major ingredient is formed on the substrate as an electric contact in a thickness of 0.03 to 100 .mu.m, and, if need be, a fixed intermediate layer is formed between said covering layer of electric contact and substrate or a fixed surface layer is formed on the outside of covering layer of electric contact, thus aiming at further improvement in the characteristics of contact. Such covering layer of electric contact can be formed by chemical vaporization or physical vaporization such as plasma CVD, sputtering, ion assist vaporization, ion plating, laser beam sputtering or the like and, by making the conditions of these vaporizations appropriate, it is possible to produce the electric contact materials having excellent characteristics of contact.

Method of manufacturing a metal-contained composite material and a

A clamping tool having a clamping head, a cylinder member coupled to an edge portion of the clamping head, a ram member coupled to and movably arranged within the cylinder member, a first die member coupled to the clamping head, and a second die member arranged to face the first die member and movable by the ram member toward and away from the first die member, wherein at least the clamping head is formed of a composite material prepared by dispersing at least one reinforcing material selected from the group consisting of ceramic fibers, ceramic whiskers and ceramic particles into a matrix metal consisting essentially of an aluminum alloy or a magnesium alloy. The clamping head is light, has a high Young's modulus, exhibits a high fatigue resistance, and is free from cracking and scattering of the cracked pieces. The clamping tool permits an operator to operate the clamping tool under a safe environment, and lessens the burden given to the operator, leading to an improved working efficiency.

Clamping tool

This invention discloses an oxide superconductor shaped body including a noble metal layer formed on at least one surface of an oxide superconductor layer formed on a substrate, and a method of manufacturing oxide superconductor shaped body.

Laminated layers of a substrate, noble metal, and interlayer underneath

A method of inexpensively fabricating a superconducting cavity having thin, clean, and smooth superconductive films of excellent resonance characteristics, and the steps of forming a first thin film layer made of hydrogen transmission-preventive metal on the outer periphery of the core made of a metal having a higher ionization tendency than hydrogen in the electrochemical series, then forming a second thin film layer of superconducting material on the outer periphery of the first thin film layer, forming a third thin film layer made of a metal having a high thermal conductivity and a high bondabilty on the outside of the second thin film layer, forming a reinforced coating layer of stabilizing metal through composite fiber plated with copper on tungsten fiber on the third thin film layer, forming a cooling pipe on the outside, and then removing the core and the first thin film layer by dissolving with the surface of the superconductor being a replica of the core surface.

Method of fabricating a superconducting cavity

Growing community of inventors

Tokyo, Japan

Masanori Ozaki