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The car's ride of electric vehicle (EV) is quite different from that of internal combustion engine(ICE)vehicle. Nonetheless, only limited discussion has held so far. We have carried out noise and vibration measurements using EV in order to compare to ICE vehicle. We have found that sound quality index in addition to sound pressure level are useful to evaluate distinguished sound of EV. Also, the characteristics of sound field in cabin are found to be quite different each other.

Recently, SiCr clean steel wire for springs on automotive engine valves has been developed. This report describes the characteristics of valve springs subjected to a new manufacturing process using SiCr clean steel wire. The process developed by the authors is as follows: First, form a helical spring with SiCr clean steel wire. Next, quench using the distortion preventing technic --Marquenching--. Temper at a temperature lower than the conventional temperature. Shot peen to the surface layer of the spring. And lastly, polish electrolytically to remove micro surface defects formed through shot peening. Using this new manufacturing process, a valve spring with high fatigue resistance can be produced. At the test stress of 588MPa(τm)±490MPa (τa), the number of cycles to fracture was above 100 million, while the number of cycles to fracture was 4 million using the conventional process with the SiCr clean steel which has the best fatigue resistance for commercial use.