Mitsubishi Denki Kabushiki Kaisha

Mitsubishi Denki K.k.

Yoshihiro Ueda

Shigeo Ueguri

Yoichiro Tabata

Akihiko Iwata

Masanori Mizuno

Osamu Nagano

Tatsuki Okamoto

Hiroyuki Sasao

Kazuhiko Hara

Yoshiaki Katou

Hajimu Yoshiyasu

Soichiro Okuda

Yoshiaki Kato

Kouichi Ono

Masami Kii

Tatsuo Oomori

Shigeto Fujita

Hiroshi Itou

Koji Ibuki

Takashi Kumagai

Junichi Nishimae

Masakazu Taki

Hiroshi Itoh

Kenji Yoshizawa

Suenobu Hamano

Kosaku Itai

Shinji Murata

Suichiro Okuda

Tadashi Yanagi

In pulse welding apparatus of arc welding or short-circuit transfer type arc welding in which a pulse discharge created on the tip of a wire electrode is utilized to perform welding, when a molten droplet produced on the tip of wire electrode is late to separate from the wire due to variations of welding conditions and external disturbances, the wire-supplying speed at which the wire is supplied to the weld zone changes causing undercut. To prevent this, pulse current supplied to the base metal is divided into a plurality of pulse groups and the average current reaches the maximum peak value at a predetermined time after beginning of outputting the pulses, and the group of pulse currents is of a hill-shape in its envelope in accordance with the separation phenomenon of molten droplet, and the group of pulse currents is arranged to have different pulse period, pulse width, and pulse interval. In sort-circuiting arc welding, the short-circuit and arc are instantly controlled in accordance with the detected arc length or wire-supplying speed. This ensures the separation of the molten droplet and its transfer onto the base metal in regular manner. As a result, the growth and separation of molten droplet is not affected by magnetic blow of arc but is controllable.

Pulse welding apparatus

In pulse welding apparatus of arc welding or short-circuit transfer type arc welding in which a pulse discharge created on the tip of a wire electrode is utilized to perform welding, when a molten droplet produced on the tip of wire electrode is late to separate from the wire due to variations of welding conditions and external disturbances. The wire-supplying speed at which the wire is supplied to the weld zone changes. This causes undercut, i.e., a defect in welding bead-shape that presents adverse effect to welding quality. To prevent this problem, pulse current supplied to the base metal is divided into a plurality of pulse groups and the average current reaches the maximum peak value at a predetermined time after beginning of outputting the pulses, and the group of pulse currents is of a hill-shape in its envelope in accordance with the separation phenomenon of molten droplet, and the group of pulse currents is arranged to have different pulse period, pulse width, and pulse interval. In the sort-circuiting arc welding, the short-circuit and arc are instantly controlled in accordance with the detected arc length or wire-supplying speed.

A pulse welding apparatus using a pulse discharge such as a pulse arc welding apparatus and a short-circuit transfer arc welding apparatus. A pulse current waveform control circuit, which controls the pulse arc current so that a desired pulse arc current is supplied to the arc welding power supply for outputting the pulse arc current to the welding load unit, is constructed such that the optimum welding operation may be performed without having to adjust circuit components and modify circuit design. The pulse current waveform control circuit is in the form of a microcomputerized digital circuit which operates under a program to provide a desired pulse arc current. A modification of the program can provide any desired pulse arc currents without changing circuits. The optimum welding current waveform parameters or a target arc length signal is learned in the first welding stage and stored into a memory. An arc length feedback control or a current waveform control is performed under the control of program on the basis of the optimum welding current waveform parameters or the target arc length signal so as to control the faulty separation of globules when magnetic blow occurs and so as to reduce the variation of arc length due to external disturbances occurring at the welding torch so that improved welding quality is ensured under various environment.

Pulsed arc welding equipment

Pulsed arc welding apparatus

A pulse generator circuit which comprises a power supply source for outputting a high voltage signal. A first capacitor is charged with the high voltage signal output by the power supply source. A load device is supplied with the high voltage signal charged in the first capacitor. A semiconductor switch together with the first capacitor and the load constitute a closed loop. A first diode is inserted between the power supply source and the closed loop. A second diode is inserted in a closed loop and operates to suppress electrical vibrations. A second diode may have an opposite polarity to that of the first diode. A snubber circuit may also be inserted in parallel across the second diode.

Semiconductor switching apparatus

A substance vaporizing apparatus which uses a vapor of a substance generated by heating the substance in a gas-filled tube as an exciting medium or an ionizing medium. The apparatus employs an improved container for containing the substance within the gas-filled tube. The improved container suppresses the rate of emission of the vapor of the substance into a discharge space defined by the gas-filled tube to hold the vapor density of the substance at an optimum low value for laser oscillation relative to the buffer gas density in the discharge space. Thus, the mean free path of the atoms of the substance, namely the average distance traveled by the atoms between elastic collisions with the electrons, ions and neutral atoms of the buffer gas, is increased to increase the number of atoms of the subtance excited to a higher energy level, which, consequently, increases laser power and enhances laser beam or ion beam accelerating energy. The employment of segmental discharge electrodes each consisting of a plurality of partial electrodes diametrically distributed in the discharge space of the gas-filled tube enables heating the buffer gas in a substantially uniform diametrical temperature distribution, which enables to increase the length and diameter of the laser medium. The employment of two pulse generating circuits promotes the relaxation of the atoms of the substance from a lower energy level to the ground energy level to enable the next application of a pulse voltage to establish a complete population inversion, which enables the substance vaporizing apparatus to operate at a high efficiency at a high discharge frequency.

Substance vaporizing apparatus

Optical pulse waveform shaper

In a pulse generator circuit for a laser unit etc., plural semiconductor switches arranged in matrix alignment on an outer surface of a first tube are connected in series and parallel with one another, and an end of each series-connection of the semiconductor switches is electrically connected to a second tube provided in coaxial alignment to the first tube, thereby realizing a synthetic semiconductor switch for switching high voltage and large current between the other end of the series-connection of the semiconductor switches and the second tube.

A load voltage detecting device for use in an apparatus for supplying a current variable with time to a load section. The load voltage detecting device for an apparatus such as a pulsed are welding machine can accurately detect the load voltage from the output voltage of the pulse current supplying section without being affected by the reactor component and the resistance component of the load section and the elements extended to the load section such as the cables and the welding torch.

Load voltage detecting device for use in an apparatus for supplying a

A pulse arc discharge welding apparatus comprising a pulse current waveform control circuit for periodically outputting a pulse current group consisting of a plurality of pulses, pulse arc current supplying means for outputting a pulse arc current according to an output of said pulse current waveform control circuit and an arc welding means for performing pulse arc discharge with an output of said pulse arc current supplying means, to carry out a pulse arc welding operation. In such a pulse arc discharge welding apparatus, with a discharge current waveform provided in the form of high frequency pulses, the discharge light and the gas in pulse discharge and the electrode are regulated and controlled with high accuracy.

Pulse arc discharge welding apparatus

Metallic vapor laser apparatus

The invention relates to a plasma apparatus where plasma is generated utilizing microwave discharge and laser excitation is performed and plasma processing is performed. More specifically, in a plasma apparatus where a microwave from a microwave oscillator is transmitted through a microwave transmission path to a microwave circuit, and plasma is generated by a microwave discharge within the microwave circuit, a plasma generating medium for generating the plasma is filled in a space formed between a conductor wall constituting a part of the microwave circuit and a dielectric installed opposite to the conductor wall, and the microwave circuit forms microwave mode having an electric field component orthogonal to the boundary between the dielectric and the plasma.

Plasma apparatus

In a metal vapor laser, (e.g. copper vapor laser), the innermost heat shield (15) of Mo, Ta or W, which is disposed with a predetermined gap (preferably sufficiently larger than 0.3 mm) to the outer surface of the seal tube (8), is connected at respective ends to the anode terminal (2) and the anode (5), so that inductance of discharge load is considerably decreased.

Metal vapor laser

Growing community of inventors

Hyogo, Japan

Yoshihiro Ueda