Analysis of operating sounds from the power slide mechanism used for automobile seats revealed that the criteria for judging NG (quality failure) by skilled evaluators consists of the following two factors: Sound loudness, and the generation of beat sound, rattling or other noises. It was presumed that amplitude vibration modulation occurred due to two main factors, namely the whirling of the flexible wire connected to the motor, and vibration caused by play in the transmission section and backlash in the gears. Further, it was presumed that the sounds caused by the motor and transmission affected the sound pressure when superimposed. From the time history waveforms of the operating sounds and frequency analysis results, we have found parameters that align with the judgement criteria of skilled evaluators. Since it is possible to make quantitative evaluations using this judgement method, it shows promise for being a method that can eliminate the outflow of defective products to the market.

Delta Kogyo Co Ltd: Ryuichi Uchikawa, Yumi Ogura, Etsunori Fujita; Waseda University: Shigehiko Kaneko