Hitachi Construction Machinery Co., Ltd.

Yasuo Hayakawa

Yutaka Takano

Sakae Takeda

Toshio Nonaka

Chishio Koshimizu

Kazuo Fujishima

Tsuyoshi Inoue

Yoshihiko Takishita

Hikaru Yamamoto

Toru Takatani

Katsumi Miyaki

Hideo Hokari

Tosio Nonaka

Kazutaka Tateishi

A narrow gap welding method by which V-shaped or single-bevel grooved multi-layer build-up welding is carried out, comprises the steps of welding a first layer by applying a welding current by which a globule transfer pattern is made into a spray pattern by a waveform in which a direct current and a pulse current are caused to overlap, and thereafter welding the second layer by applying a direct current.

Narrow gap welding method and welding apparatus

A hydrophilic film coating ( ) is formed on outer surfaces of cab ( ), equipment housing cover ( ) and counterweight ( ) of an upper rotary body ( ), so that a water film ( ) is formed on the surface of the hydrophilic film coating by raindrops or at the time of rainfall. By formation of the water film ( ), contaminant substances ( ) which have deposited on the outer surfaces of the upper rotary body ( ) are urged to float up and carried away with dripping water of the water film ( ). As a consequence, it becomes possible to prevent development of raindrop stains on the outer surfaces of the upper rotary body ( ) and, even if spattered particles of grease have deposited on the outer surfaces of the upper rotary body ( ), such contaminants can be easily washed off, thereby permitting to maintain the quality in outer appearance of the upper rotary body ( ).

Rotary type construction machine and cab, equipment housing cover and counterweight for such construction machine

The present invention relates to an acoustic microscope system having an ultrasonic probe that is driven with a high-frequency burst signal to radiate an ultrasonic signal and that detects the resulting reflected and irradiated waves, a Z-axis moving device that updates the vertical distance Z between the probe and a material of interest for each sampling position, and device for constructing a V(z) curve from the reflection signals obtained at respective sampling positions. The ultrasonic probe of the invention is provided with an acoustic lens, a first ultrasonic transducer for receiving a leaky surface skimming compressional wave reflected from a sample material on one side of the acoustic lens, and a second ultrasonic transducer also provided on the side of the acoustic lens for receiving a leaky surface acoustic wave.

Acoustic microscope system

In an ultrasonic inspection method and apparatus for inspecting the presence or absence of a defect in an object to be inspected by receiving as an RF signal a reflection beam of an ultrasonic beam emitted from a probe to the object and displaying data of the RF signal on a display unit, a maximum value indicative of a positive peak of the RF signal is detected, a maximum absolute value indicative of a negative peak of the RF signal is detected, a computation is performed for comparing in magnitude the maximum value indicative of the positive peak with the maximum absolute value indicative of the negative peak, and a computed value is displayed on the display unit so that the presence or absence of a phase inversion of the RF signal may be judged for deciding the presence or absence of a defect in the object.

Ultrasonic inspection apparatus

A supersonic flaw detecting system has a probe adapted to emit a supersonic wave towards an object to be inspected, a scanning device for causing a relative movement between the probe and the object in two orthogonal directions, a pulser-receiver adapted to supply pulses to the probe and receive the supersonic wave from the object and produce an electric signal indicative thereof, a signal processing device for converting the electric signal from the pulser-receiver into an image data signal for a C-scope display, an oscilloscope for conducting an A-scope display of the electric signal from the pulser-receiver, and a monitor T.V. having a screen for conducting the C-scope display of the image data signal from the signal processing device. A control unit when the probe and object are relatively moved by the scanning device, the image data carried by the image data signal from the signal processing device at a corresponding address in the image memory at each pitch which has been determined such that the number of data pickups during the relative movement between the probe and the object coincides with the number of the corresponding addresses in the image memory to thereby cause C-scope display of the image data to be effected on the screen. The is operative to compute, when the cursor is displayed on the screen by the operation device, the amount of operation of the scanning device necessary for locating the probe relative to the object at a position corresponding to the cursor on the screen and operate the scanning device by the thus computed amount to locate the probe at the corresponding position, thereby permitting A-scope display to be effected at such a position on the oscilloscope.

Supersonic flaw detecting system

Growing community of inventors

Ibaraki, Japan

Yasuo Hayakawa