Prise winners list

Development of Takumi (master's) frame structure that reduces CO2 emission amount to 1/10 of casting manufacture, lead time to 1/15 and environmental pollution as well

Minokamo-City, Gifu Prefecture
Yamazaki Mazak Corporation
Other award winners
Kenichi Ito, Hiroyuki Kanematsu, Tetsukazu Kitamoto, Yasuhiro Furuta, Naoomi Miyakawa, Katsutoshi Yoshizawa
Recommended by
Yamazaki Mazak Corporation
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Muto, Yoshihiro  (56)
Technical Dept., Assistant Manager

"Japan's traditional architectural method is used for manufacturing of laser beam machine frame", this strange idea has produced unexpected effects.
summary

Manufacturing of the base section (base and column) of laser beam machines, which this company produces, was conventionally outsourced to a casting manufacturer. However, it took 3 or 4 months to manufacture such a big cast frame, so it was necessary to issue a purchase order in advance by forecasting incoming orders and sometimes the company had to carry extra inventory. In addition, the number of casting manufacturers was dwindling because high skill was required for casting manufacture and on-site work for it was "hard, dirty and dangerous". This company cuts the flat steel plates accurately with a laser beam machine and joints the cut plates by "tenon and mortise, shim and joint", which were used in Japanese traditional architecture, as well as bolts and welding to manufacture one structural "Takumi (Master's) Frame". This new technology reduces manufacturing time and cost and environmental burden drastically.

summary

The manufacture of the laser beam machine faces crisis because of the dwindling number of casting manufacturers.

I have worked for development of laser beam machine in the past twenty years and have said to my subordinates, "The base of laser beam machine must be made of cast metal". Therefore, when I was instructed by my boss, "Think about use of a new method, not casting", honestly I felt hesitant". However, we could not avoid the reality that manufacture of cast metal would become difficult more and more.

To manufacture the base of laser beam machine by casting, we must make a wooden frame having exactly the same shape as the base, burry it into sand to make a mold, flow melted metal into the mold and finally anneal the solidified cast metal. Basically we must ask an outside casting manufacturer to manufacture cast products, but usually it takes 3 to 4 months to manufacture a laser beam machine base. Therefore, we must forecast incoming orders and issue our purchase orders in advance, resulting in unnecessary inventory of cast products. 

However, the more serious problem is that the number of casting manufacturers discontinuing their business is increasing. Young people do not take this job because high skill is required for casting manufacture while the work is hard and dangerous. We had a sense of crisis, "We cannot expect a stable supply of cast product any longer". One alternative is plate work, but this method has both merits and demerits. In plate work, steel materials such as pipes and shaped steels are cut and welded to make a structural product and the material strength is stronger than cast metal. However, dimensional accuracy is not so good and longer work time is required because the steel plates are melted and connected. In addition, if the frame resonates due to vibration during laser beam machining, machining accuracy decreases and feeding speed is limited.

Why does not the five-story pagoda of Horyuji Temple topple though 1000 years have passed since its construction?

Is there any manufacturing method other than casting and plate work? We, development engineers, have had many meetings and one our top management officials proposed an unexpected idea. "Why does not the five-story pagoda of Horyuji Temple topple though 1000 years have passed since its construction? How about using a method that uses tenon, mortise and shim instead of nails and can absorb vibration caused by an earthquake just like the five-story pagoda?" 

Plate work products cannot absorb resonance because parts are welded into one structure. Therefore we thought that if we joint parts with tenon, mortise and shim and avoided using nails wherever possible, vibration energy can be absorbed effectively because of friction among the joints. A laser beam machine is best suited for cutting the steel plates, tenon and mortise so that they can be jointed very accurately. In this method, we can manufacture frames for ourselves.

"We started study and development early 2004. While repeating test production, it became clear that our newly developed frame had drastically superior performance. "When we hit a cast frame and our new frame with a hammer, the former emitted a long resonant sound like a bell while the latter emitted a short nonresonant sound. The difference was very clear to anyone. Although I had been half in doubt, I became confident that the new method would be a great success."

However, we have suffered hardship since then. It was necessary for us to make the structure clear theoretically and establish standards as to which joint method should be used for which and how many parts. Simulation analysis can be performed for casting and plate work but cannot be performed for a frame produced in this new method because parts are not completely jointed and so its behavior is complicated. 
"We had to actually measure every joint and make design standards clear by performing parameter processing. We took great pains to solve this problem."

In this way, the newly developed frame was put into practical use in November 2004 and was named "Takumi (Master's) Frame" in respect for our ancestors of Japanese traditional architecture. Takumi frame has brought about many merits including prominent performance of laser beach machine frame. Manufacturing period was reduced to nine days (currently five days) and there is no need to have stock and production cost is cut. Takumi frame does not need huge amount of energy like casting and so contributes to reduction of CO2 emission. "The proposal by our top management was so unexpected, but we did not deny the new way of thinking but attempted it aggressively and so could make a success", we think. 

Takumi frame is expected to be used widely not only for a laser beam machine but also for semi-conductor manufacturing machine and construction equipment.

Yamazaki Mazak Corporation

http://www.mazak.jp

Established:
Jun. 1965
Capital:
80 million yen
Employees:
180(as of Dec. 2009)
Brief information:
Started manufacture of laser beam machine in 1985. Develops and manufactures CNC equipment and linear motors and has its own technology for cutting 3D objects such as pipes

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.By using tenon, mortise, shim and joints, which were used for traditional wooden architecture, as many as nearly 400 steel plate parts are jointed to complete a base section (base and column) of laser beam machine.

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Steel plate is cut and processed into piece parts of frame accurately with the company's own laser beam machine. Thus it became possible for the company to manufacturer bases and columns for itself.

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Takumi frame is manufactured by using mechanical joints including tenon, mortise, shim and bolts and by spot welding for whirl stop.