Hitachi Zosen Corporation

Osaka Transformer Co., Ltd.

Toshiyuki Okada

Hideyuki Yamamoto

Hideki Saito

Katsuya Sasaki

Yoichiro Nakamura

Kyoji Chikira

Motomitsu Suzuki

Tomonori Takemoto

Hiroshi Nakayama

Takayuki Iwamuro

Masato Aoki

Michiya Kiyohara

Shigeharu Okumura

A tunnel boring machine includes: a cutter head; a cutter support; a cutter driving unit; a rotational position sensing unit; a strain sensor; and a data processing unit configured to calculate a force acting on the cutter head in association with the position of the cutter head in the rotational direction, based on sensing results of the strain sensor and the rotational position sensing unit.

Tunnel boring machine

The tunnel boring machine includes a data processing unit configured to obtain error data (E) based on a current measurement value (Vp) of the strain sensor obtained at a current angle (&#x3b8;) of the cutter head and a past corresponding measurement value (Vo) obtained at a corresponding angle corresponding to the current angle, to correct the current measurement data using the error data.

A segment roundness measuring device including a correction means that corrects the positional deviation of the turning center of an erector turning portion resulting from eccentricity on the basis of an angle detected by an angle detector and distances measured by three or more distance meters arranged at angular positions different from each other in the erector turning portion.

Segment roundness measuring device and segment roundness measuring method

A vibrating apparatus for vibrating a mold 1 by an electrohydraulic stepping cylinder 5 through a link mechanism 3 is characterized in that when a driving signal delivered into a drive unit 26 for the stepping cylinder 5, the actual acceleration of the mold 1 is fed back to a target waveform signal for the mold 1 and compensating signals for cancelling the operation delay of the stepping cylinder 5 and the signal transfer lag due to elastic deformation of the link mechanism and the like are added thereto to make feed-forward compensation.

Mold vibrating apparatus in continuous casting equipment

An a.c. arc welder includes a reactor between a source of a.c. power and a welding load for accumulating energy during the increase of voltage from the source. A bypass circuit is further provided in parallel to the reactor and the welding load for dissipating the accumulated energy as a welding current through the load.

A.C. Arc welder

A method and apparatus for controlling the welding current in shortcircuit transfer arc welding including a method and control apparatus for maintaining the effective value of the welding current during arcing period at a predetermined value. Maintenance of the effective value of welding current during arcing period is necessary to keep the size of a fusion zone and the depth of penetration constant throughout welding operation.

Method and apparatus for shortcircuiting arc welding

An AC arc welder which comprises means for detecting the welding current, a comparison circuit for generating logical output signals by comparing the output voltage or output current of the welding current detecting means with the reference voltage or reference current from a reference voltage generating means, digital means for generating logical output signals by performing adding operation or subtracting operation in response to the logical output signal, current supplying means for supplying the output current whose common ratio becoming the geometrical series of approximately m(m = 1, 2, 3 . . . ), and switching means for on and off- controlling the output of the current supplying means in response to the logical output signals of the digital means, thus forming a current feedback loop, whereby the output current from the current supplying means can be changed minutely, thus ensuring stabilized control characteristics.

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Osaka, Japan

Toshiyuki Okada