Kabushiki Kaisha Toshiba

Hiromichi Somei

Kenji Watanabe

Tsuneyo Seki

Mitsutaka Honma

Kumi Uchiyama

Junichi Sato

Atsushi Yamamoto

Tsutomu Okutomi

Eiji Kaneko

Mitsutaka Homma

Kiyoshi Kagenaga

Takashi Kusano

Iwao Ohshima

Yoshimitsu Niwa

Tadahiro Aihara

Ryosuke Sasaki

There is provided a vacuum circuit breaker including a vacuum valve, a first main circuit conductor fixed to a fixed current-carrying rod end of the vacuum valve, a polygonal movable conductor connected to a movable current-carrying rod end of the vacuum valve, an operation movable rod connected to the movable conductor in an axial direction and connected to an operation mechanism, a second main circuit conductor, through which the operation movable rod is movably inserted, and at least one extendable flexible conductor, which connects side surfaces of the movable conductor and the second main circuit conductor.

Vacuum circuit breaker

The flux density Bct is applied at the center area of the electrode. The flux density Bct is adjusted within the range A of 0.75 to 0.9 times greater than the axial flux density Bcr which gives the lowest arc voltage between the electrodes against each breaking current. The axial flux density monotonously increases from the center to the circumferential area of the electrode. Here, the radial position where the axial flux density Bcr which gives the lowest arc voltage Vmin is adjusted within the region B of 20% to 40% of the radius of the electrode. The axial flux density is made monotonously increase in an outer area from the region B and give the maximum value Bp in a circumferential area equal to or beyond 70% of the radius of the electrode. The maximum value Bp is adjusted within the range C of 1.4 to 2.4 times greater than the flux density Bct given at the electrode center.

Vacuum valve

A method for improving flux density in a vacuum valve, includes producing, with a vacuum valve, an axial magnetic field parallel to an arc generated between a movable and a stationary electrodes facing each other, and adjusting a magnitude of an axial flux density between the electrodes to increase gradually from a center area of the electrodes toward a circumferential area of each electrode. A point gives a maximum value (Bp) of the axial flux density at a location of and beyond 70% of a radius from the center of each electrode, and the maximum value (Bp) of the axial flux density in a radial line from the center to a circumferential end to be 1.4 to 2.4 times greater than a flux density of the center Bct of each electrode.

A vacuum valve which has a contact material having a constituent of high electrical conductivity such as Cu and an anti-arcing constituent including Cr in which particles whose particle size is in the range 0.1.about.150 .mu.m represent at least 90 volume %, and a ratio defined by the formula (.alpha..sub.900 -.alpha..sub.50).times.100/(.alpha..sub.900) for this contact material has a value of 8-12% and is the coefficient of thermal expansion of the contact material .alpha..sub.50 is the coefficient of thermal expansion of the contact material at 50.degree. C. The formation of channels generated at the interfaces of the Cr particles and the Cu matrix after undergoing the brazing step is suppressed, enabling the static withstand-voltage, contact resistance, and the breaking performance characteristics of the vacuum valve to be stabilized.

An electrode arrangement of a vacuum circuit breaker for making and breaking electrical connection. The electrode arrangement has: a pair of contact members which are adopted for making contact to and release from each other by relatively moving to and from each other along a predetermined direction; a pair of electrically conductive bars being connected to the above pair of contact members, respectively, for providing electric conduction to the contact members; and a magnetizing device with a magnetic body for generating magnetic field parallel to the predetermined direction between the contact members. The magnetic body is composed of an iron alloy comprising 0.02 to 1.5% by weight of carbon and iron. The iron alloy may further contain at least one of manganese and silicon.

Electrode arrangement of vacuum circuit breaker with magnetic member for

A method for manufacturing a vacuum interrupter including, a vacuum enclosure composed of an insulating tube sealed by metal flanges, a pair of electrodes in the vacuum enclosure which are able to make and break contact, and a pair of conducting shafts. The method includes the steps of preparing a fixed-side assembly composed of a fixed electrode, a fixed-side conducting shaft and a fixed-side flange jointed as one unit, preparing a movable-side subassembly composed of a movable electrode, a movable-side conducting shaft and a movable-side flange jointed as one unit, preparing an insulating tube subassembly composed of the insulating tube, preparing an assembly such that the movable-side, insulating tube, and fixed-side subassemblies are superimposed with first solders for gas-tight sealing being inserted between the movable-side and fixed-side subassemblies and end surfaces of the insulating tube subassembly and with a second solder for contact soldering being inserted between the contact and the electrode, and heating and evacuating the assembly in a vacuum furnace to evacuate inside the vacuum enclosure and to solder by the first solders and the second solder, thereby to obtain the vacuum interrupter. Whereby gas-tight soldering and soldering of the contact and the electrode are carried out simultaneously in the heating and evacuating step.

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Fuchu, Japan

Hiromichi Somei