[From October Issue 2013]


Many products around us are made of parts which are shaped or bored metal and resin. A car, for example, is assembled from 30,000 parts made this way. Mobile phones and digital cameras, too, contain many precision parts. Machines that make parts for such products are called “machine tools.”

Yamazaki Mazak Corporation of Oguchi Town, Aichi Prefecture (President YAMAZAKI Tomohisa) is one of the world’s most prominent manufacturers in this field. In addition to other machine tools, they also make “laser processing machines” that cut and bore through iron plate or steel with heat from a laser. This contains a mechanism that amplifies and reflects the laser’s strong beams through lenses and mirrors, onto parts to be processed.

For a laser beam machine to do precise work, it’s absolutely necessary for the lenses and mirrors to be clean. Dust and impurities contained in the air pose a threat, potentially having a negative effect on performance. So, to produce laser processing machines more rapidly, the company built a special underground factory in 2008. In the factory’s clean hermetic environment, lenses and mirrors are not adversely affected by dust or other contaminants in the air.

The factory was built in a hilly area. Buried underground at a depth of 17 meters, the building is two stories high in some parts, covering a total area of 10,000 square meters. One of the company directors was inspired to build an underground factory when he visited an underground facility in the former Soviet Union where a metric standard instrument was kept. Spokesman TOMITA Kazuhiko says, “I don’t think there’s another underground factory of this scale anywhere in the world.”

A hygienic environment is the foremost advantage to building a factory underground. Compared to a factory build above ground, the quantity of dust has been reduced to 1/20. The second advantage is that with a year round subterranean temperature of 16-18℃, the temperature is naturally regulated. By pumping air into the factory from above ground and circulating it through its inner walls, in summer temperatures reach 28℃ at their highest and in winter 18℃ at their lowest.

The heat emitted from machines undergoing testing on the assembly line is expelled through concrete tubes crisscrossing the floor. That heat is used for internal heating in wintertime. The factory contains no large air conditioning system. But since the temperature is kept within a certain range, the company saves about 90% on annual air-conditioning costs for the factory.

Other advantages include: “the aboveground space is available for practical use” and “minimal vibrations from cars and railways.” Because of these original features, the factory won the “Ministry of Land, Infrastructure, Transport and Tourism’s Land Utilization Model Grand Prix” in 2008 and the “Nikkei Earth Environment Technology Award/Production Environment Special Award” in 2009. More underground factories, based on this design, may be built all over Japan in the future.

Yamazaki Mazak Corporation

Text: ITO Koichi













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