Hitachi Industrial Equipment Systems Co., Ltd.

Koji Ikeda

Kazuyoshi Iida

Kazuaki Shiinoki

Toshiaki Yabe

A conventional machine package faces problems concerned with costs, weight, etc. and also a problem of antinomy that an attempt to enhance the noise reducing performance increases the airflow resistance and then deteriorates the cooling performance. Providing a sound absorbing structure with the heat radiation performance ensured within a practical range and then with considerably improved noise reducing effect achieves a low-noise machine package with a downsized casing and a reduced cooling fan power. There is provided a sound absorbing structure having a plurality of polyester fiber sound absorbing cylinders each formed into a circular-cylindrical shape, formed of a base material of polyester fiber whose surface is combined and covered with polymer nonwoven fabric of polyester fiber or the like, and arranged at a support member in at least either of a suction port and an exhaust port in such a manner that long axes of the sound absorbing cylinders intersect substantially perpendicularly with a flow direction of air flowing through the suction port or the exhaust port. This makes it possible to reduce noise while controlling the airflow resistance minimum, thus achieving downsizing of a cooling fan and reduction of a cooling fan power.

Growing community of inventors

Sakai, Japan

Koji Ikeda