Evaluation of the dynamic characteristics of the human body-seat system and ride comfort using actual vehicle vibration

Takuya Yoshimura･Kouji Ogasawara･Gen Tamaoki (Tokyo Metropolitan University)･Shuya Nojima･Hirotaka Shiozaki (Mitsubishi Motors)

The six-axis actuator reproduce the floor vibration when the car running in an actual road. The principal modes of car seats are analyzed and compared with respect to two kinds of seats at several different speed of the car. The principal modes that have significant effects to the ride comfort are investigated.

Development of Comfortable Operating Sound for Power Seat (Part 1)
-Optimization of Gear Meshing Force for Reducing Power Seat Operational Noise-

Keiichiro Shinbori･Atsushi Ssto･Rui Tokida (Toyota Boshoku)

With the rapid electrification of vehicles, the demand for reducing cabin noise has increased. In this study, attention was focused on the gear meshing excitation force of the motor in power seat systems. A 1D-CAE model was developed, and optimization analysis was conducted to evaluate the reduction effect of the excitation force. The effectiveness of the proposed method for application in the early design stage was also demonstrated.

Development of a Prediction Method for Ventilation Noise Reduction in Air-Cooled Battery Units (Prediction of Duct Attenuation)

Fumihiro Chatani･Takuo Watanabe･Masanobu Nishiwaki･Akira Ohtagaki (Toyota Motor)

Blower-induced ventilation noise is a key issue in the development of cooling performance for HEV battery packs. This study develops a prediction method focused on sound attenuation in duct sections (“duct attenuation”). Using the duct system of a production vehicle, the effects of sound-absorbing materials and duct bends on attenuation characteristics were verified.

Boundary Layer Control and Flow-induced Noise Reduction in Duct Bends Using Surface Microstructures

Shunpei Nomura･Sobue Yuta (Gifu University)･Sho Kosaka･Kenji Yoshida･Kaori Seki (DENSO)･Yasuhiko Sakai (Nagoya Industrial Science Research Institute)･Shuho Yamada (Toyama Prefectural University)･Osamu Terashima (Gifu University)

This study experimentally investigates the effects of boundary layer control using surface microstructures smaller than 1 mm on flow-induced noise and pressure loss in separated and reattached flows occurring in bends of ventilation and air-duct systems. The results reveal that optimizing the characteristics and geometry of the microstructures enables reduction of flow-induced noise in specific frequency bands without increasing pressure loss.