[in Japanese]

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[in Japanese]

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[in Japanese]

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The combination of a laser displacement transducer and strain gauge is a newly devised to measure the elastic deformation of the tool-workpiece interface in cold forging. A deep hole is bored close to the inside surface of the die container, and a steel pin is placed in the hole to detect the minute displacement of the near die-workpiece interface. The movement of the pin is men measured by the transducer which is attached on the die surface. The displacement of the installation position of the transducer is measured simultaneously by the strain gauge method to adjust the measurement obtained from the transducer. This method is applied to the measurement of die deformation in the backward extrusion process. The displacement distribution of the die-workpiece interface under various conditions is obtained. It is proved that the newly developed method is effective for the measurement of die deformation in forging.

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In this paper, we propose a method to estimate the sound source in 3D space using a loudspeaker. The cross-correlation analysis estimates accurate sound source location, when the level of the sound in sufficiently high. But it yields erroneous location when the sound is small. In order to detect the hitting time of sound from the source to the speaker, the amplitude of the slope in a serene sound was compared with it of the unusual sound. As a result, the sound source position in the space was estimated with stability by the suggesting method.

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Conventional software datums for straightness profile measurement are error separation techniques that separate a surface profile from parasitic motions by using multiple sensors and/or multiple arrangements. However, random error propagation of the multiple sensor method has been reported in the case of large sampling numbers. The authors already proposed the novel two-point method for straightness profile measurement. The proposed method can reduce the propagation of uncertainty caused by the cross-axis motion, pitch motion and random error of the estimated surface profile. The proposed method consists of a weighted addition and inverse filtering. The suitable weight of the weighted addition that gives the least uncertainty propagation is derived by a simple equation using the standard deviation of the cross-axis motion, pitch motion and random error. Here, the authors discussed the characteristics of the pitch motion in the spatial frequency domain.

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