Hitachi, Ltd.

Hitachi Chemical Company, Ltd.

Hitachi Engineering Co., Ltd.

Fumio Suzuki

Tadasi Sonobe

Ken Yoshioka

Teruhiro Takizawa

Masayuki Shibata

Hideshi Fukumoto

Shigeru Sakamoto

Yoko Kameoka

Takashi Kobayashi

Sueo Kawai

Yoshiyuki Tsuru

Naoki Maki

Saburo Usami

Toshio Saitoh

Hiroshi Aoyama

Toshio Hattori

Fumihiko Goto

Tadashi Isono

Yutaka Taniguchi

Tosuke Hirata

Yumiko Seki

Naoki Kasahara

Toshio Ishizuki

A chip fuse comprising an organic resin-made insulating substrate, a pair of electrodes formed at terminals of said organic resin-made insulating substrate, current protecting element wiring portions and a current protecting element positioned between said pair of electrodes and housed in said organic resin-made insulating substrate, said current protecting element having a thickness of 3-8 .mu.m and being supported on an organic resin layer having a high tracking resistance, and at least one space being formed at least on the current protecting element side, does not cause ignition nor smoking and is excellent in clearing characteristics.

Chip fuse and process for production thereof

A superconducting magnet abnormality detection and protection apparatus is for early and surely detecting abnormality in superconducting coils mounted on a vehicle and protecting the superconducting coils. Magnetic flux detecting devices are mounted inside an outer vessel, which is a vacuum container of a superconducting magnet, so as to be opposite to the superconducting coil. Voltages induced in the magnetic flux detecting devices are detected. Voltage signals are led to a decision device. By monitoring the change of the voltage signals with time in a comparing judgment device, it is determined whether there is an abnormality. If there is an abnormality, an alarm indicator informs of an abnormal state, and a protection device takes protection measures such as interruption of the current of the superconducting magnet. Owing to such configuration, heat does not penetrate from the outside into the superconducting coil via instrumentation lead wires of the magnetic flux detecting devices. Magnitudes of vibration and displacement of the superconducting coil can be detected without contacting the superconducting coil. By always monitoring these signals, it becomes possible to early detect an abnormality in the superconducting coil and protect it.

Superconducting magnet abnormality detection and protection apparatus

A beam member which is installed at diametral portion in a ring shape superconducting coil container for supporting hoop stress of the coil, or a portion of radiant heat shield covering the beam member, is partly or entirely composed of electrical insulators or high resistivity materials. In accordance with the above composition, eddy current which is generated in the coil container when the superconducting coil container crosses magnetic field caused by eddy current which is generated in the radiant heat shield when the radiant heat shield crosses strong magnetic field caused by the superconducting coils with relative vibration of the radiant heat shield to the superconducting coil by a dynamic cause can be suppressed. Accordingly, heat generation in the superconducting coil container can be reduced, and consequently, generation of quenching can be prevented.

Superconducting magnet

A superconducting magnet includes a superconducting coil, an inner tank for containing the coil, a shield plate for covering the inner tank, and an outer tank for accommodating the superconducting coil, the inner tank and the shield plate. The inner tank is supported on the outer tank by a load support member and the outer tank forms a vacuum vessel. At least one of the inner tank, the load support member, the shield plate and the outer tank includes a detection arrangement for detecting abnormality and/or deterioration of the inner tank, load support member, shield plate and outer tank associated with the respective detection arrangement.

Superconducting magnet magnetically levitated transportation apparatus

There is disclosed a coil structure which can be rapidly energized or excited, and which reduces the generation of heat in a coil container by an eddy current due to a dynamic disturbance such as vibration and a magnetic field fluctuation, thereby suppressing the occurrence a quench. The coil container is constituted by a low-resistivity material, and a high-resistivity portion is provided at at least one portion of the coil container in the direction of the periphery of the coil container. The high-resistivity portion is provided at a position where a vibration displacement is small or a magnetic field fluctuation is small. When the coil structure is to be energized or excited, the eddy current produced in the direction of the periphery of the superconducting-coil container can be reduced at the high-resistivity portion, and when the dynamic disturbance develops, the generation of heat by the eddy current is suppressed by the low-resistivity material.

Coil structure and coil container

Growing community of inventors

Hitachi, Japan

Fumio Suzuki