Yamaha Motor Monthly Newsletter July 14, 2017 (Issue No. 55) The Rev in Yamaha s Businesses Yamahaʼs Casting Technology The Factories Contributing to High-quality Monozukuri Yamaha Motor developed its casting and forging technologies in an ongoing quest for lightness, strength and beauty, and you can view Yamaha s metalworking history, facilities, part portfolio and more on the global website. Yamaha Motor is dedicated to Monozukuri (engineering, manufacturing and marketing products with an emphasis on craftsmanship and excellence) with a high standard of quality that moves and inspires people. We employ innovative concepts, technologies for maximizing user fun and confidence, and our Refined Dynamism design ideals during the product development stage, but it is the manufacturing and production divisions that are responsible for transforming it all into an actual product. These divisions also have decades of experience and are always working to further their technological capabilities and know-how. One of their areas of expertise is casting the metal parts used in our motorcycles, outboard motors, automobile engines and other products. From 2017, we are now not only casting parts for Yamaha products, but opening our doors and expertise to outside clients, offering metalworking solutions and job-order production on a global basis. In this issue, we introduce Yamaha Motor s beginnings and expertise in the field of casting. Yamaha Motor Monthly Newsletter 1
The Challenge: Casting Was Key to the Birth of Yamaha Motor Casting is a method of shaping metal that can be likened to the way children create chocolates shaped like flowers or animals. The material is heated until it melts and poured into the mold, then cooled until it solidifies and finally removed from the mold as a single piece. It is then given a clean finish to complete it. The origins of casting lie in ancient times and is said to have begun when utensils were first made of cast bronze in Mesopotamia around 4,000 BCE. The method later developed and spread into much wider use with the industrial revolution in the middle of the 18th century. In March 1954, President Genichi Kawakami of Nippon Gakki Co., Ltd. (today s Yamaha Corporation) was considering going into the motorcycle business and was showing the cylinder of a German DKW motorcycle engine to the head casting engineer in the company s metalworking department. Kawakami asked if it was possible for his department to cast one like it. If not, the president added, he would give up the idea of manufacturing motorcycles. Shortly after World War II, Nippon Gakki acquired a casting company in Hamamatsu as a step toward restarting piano production. This marked the beginning of the in-house casting of iron piano frames. As the taut strings of a piano are said to apply around 20 tons of force to its frame, Nippon Gakki s engineers worked diligently to cast frames that not only had the rigidity to withstand these forces but also had the right elasticity to flex and produce beautiful, high-quality sound. However, an engine cylinder has a more complex shape and requires a high degree of casting precision, and it was painfully clear that casting one with the quality as DKW would be no easy task. Nonetheless, the casting engineers decided to take on the challenge. At the time, piano frames were made with green sand casting. Cores (model pieces shaped exactly to the form of the parts to be cast) are pressed into the sand in two mold boxes, which are then hardened to form a mold into which the molten metal is poured. Using this method, the engineers made repeated attempts to cast a cylinder for their first prototype motorcycle, but they failed again and again because the molten iron failed to completely fill the mold properly. When they finally managed to cast some prototype cylinders and presented them for inspection, they were ridiculed as looking more like clay teapots. What eventually led to success was when Nippon Gakki technicians saw an article about using shell molds the latest in casting technology at the time in an American trade magazine. Looking to get a more beautiful cast for the tuning fork mark that adorned the company s piano frames, they managed to duplicate it. In this process, phenolic resin is mixed into the fine silica sand used to make the molds, which are then baked to harden them. Since these molds are much stronger, the molten metal fills cavities better and makes it possible to cast pieces with excellent precision and beautiful surfaces. The motorcycle casting team quickly leased use of the equipment at a local foundry in Osaka, and they were not only able to cast a proper cylinder but also to continue refining its quality. Casting the first YA-1 cylinder prototypes was a long process of trial and error, but using shell molds finally produced beautiful, high-precision castings. Meanwhile, worries about development delays caused some within the company to call for outsourcing cylinder production. But President Kawakami countered by directing in-house casting development to continue, saying that it was no good to outsource the creation of the most important part influencing a motorcycle s performance and that for the future of the business, cylinder Yamaha Motor Monthly Newsletter 2
production must be done in-house, no matter how difficult the task. With the resulting completion of the YA-1 as the first Yamaha motorcycle, Nippon Gakki s motorcycle-related departments were spun off and founded as Yamaha Motor, with the new company inheriting these casting technology advances. Technological Development: Striving for Lightness, Strength and Beauty After successfully creating the cylinder for the YA-1 engine, Yamaha began R&D into various metals and casting methods. Acquiring experience and mastery in the process, the factories turned out cast parts one after another with the right performance and quality while answering the demands of the product developers. Among the different metals, aluminum proved to be better suited than iron or steel for many of the parts in motorcycles, outboard motors and automobile engines thanks to benefits like its light weight, resistance to rust, high heat conductivity, machining ease, recyclability and lack of toxic qualities. Furthermore, it became possible to manufacture parts exactly as desired by adding elements like silicon, magnesium, zinc and copper to make a variety of aluminum alloys, and then using different methods such as shell-mold casting, high-pressure die-casting and low-pressure casting. Gravity casting, in which the molten metal settles slowly into the mold without the use of injection pressure, is suited to creating parts like wheels with complex shapes or hollow parts. It was this ongoing process of uncompromising efforts to meet numerous stringent performance demands in-house that led Yamaha to its wealth of exclusive casting technologies and know-how it enjoys today. For example, the cylinder and piston of Yamaha s first outboard motor, the P-7 released in 1960, were cast with shell molds and used an aluminum alloy with a high silicon content as a measure to stave off rust and corrosion. After further research, Yamaha succeeded in creating a new aluminum alloy in 1993 named YDC-30, which provides excellent performance and reliability while still being resistant to saltwater corrosion. The alloy is employed for casting the bottom cowling of outboard engine casings and the lower unit of the outboard that is immersed in the water. For Yamaha motorcycles, the use of cast aluminum parts began with crankcases, and in 1967, Yamaha developed and patented its Metallic Bond Cylinder, which used an aluminum-iron alloy to fuse a cast iron liner to a cast aluminum cylinder and thus produce a lightweight cylinder with stable cooling qualities. This technology was immediately adopted on four models, including the 350cc twin-cylinder R1 sport bike. As for chassis parts, Yamaha became the first manufacturer in the industry to mass-produce cast aluminum wheels, reaping the benefits of their excellent balance of strength and rigidity. Beginning with the XS750C released in the U.S. and Europe in 1976, Yamaha introduced these wheels on a number of models, and they eventually became the standard for motorcycle styling. Yamaha s controlled filling (CF) aluminum die-casting method used today for casting the frames of models like the MT-09 is different in that factors like the flow speed of the molten aluminum, the degree of vacuum in the mold and its temperature are all precisely controlled. This results in more uniform solidification of the aluminum and inhibits the formation of air bubbles in the finished piece, enabling the casting of lightweight, thinner-sectioned and high-precision aluminum parts with smoother surfaces. Furthermore, this technology enabled use of an aluminum alloy with 20% silicon content, a material that was unusable with previous casting methods. Yamaha Motor Monthly Newsletter 3
This gave Yamaha the means to create its proprietary low-cost, high-performance DiASil (Die-casting Aluminum Silicon) Cylinder that needs no cylinder sleeve or wall plating. First used on the T135, this cylinder s use has now spread to other smaller displacement sport models like the YZF-R25/R3. The DiASil Cylinder used on sport models like the YZF-R25/R3 The cumulative advances made possible by this technology also led to further advances like die-casting with alloys of magnesium a metal quite difficult to handle when casting. This technological progress subsequently enabled the development of a cost-efficient method to mass-produce cast magnesium wheels and subframes superior to aluminum in their weight savings. Going Further: Bringing Yamaha s World-Class Quality to New Clients It isn t a product if it isn t world-class are famous words of President Kawakami. Ever since its founding, Yamaha Motor has been dedicated to high-quality Monozukuri and actively marketing its products globally, but Yamaha was also among the first manufacturers to move production overseas to the markets individual products were designed for. In addition to the Iwata Main Factory in Japan, parts for our products are manufactured today at factories located in eight other countries overseas, and monthly shipments total some 11,600 tons of aluminum parts and around 1,370 tons of iron and steel parts. What s more, the 216 die-casting machines, 93 low-pressure casting machines and 38 gravity casting machines in this global network are all of the same standard, as are the mold types, production methods and materials used. This ensures that no matter what country a production base is located in, it can produce cast parts of the same high quality as our factories in Japan. This is the foundation on which the global reputation of Yamaha product quality and reliability is built. And in 2017, Yamaha has begun offering OEM casting solutions and services to manufacturers not only in Japan, but also to companies operating parts production factories overseas in order to make wider and more effective use of our casting facilities, technology and know-how garnered from over 60 years of experience in the field. Behind this ambitious new business endeavor is the pride of our casting experts. Their determination to contribute to product development from the initial planning, design and engineering stages and their spirit to take on any challenge no matter how difficult and see it through to success is expressed in the venture s slogan, We Like a Challenge: The Tougher, the Better. Process for Casting Aluminum Wheels Ingots of aluminum alloy The ingots are heated into a molten state The molten aluminum is poured into the mold and solidifies The wheel is removed from the mold and heattreated to achieve ideal hardness and strength The wheel is then deburred, machined and painted to complete the process Yamaha Motor Monthly Newsletter 4
Message from the Editor As a fundamental process in Monozukuri, casting itself taking raw metal, melting it and then shaping it lies at the very origins of Yamaha Motor as a manufacturer. The Iwata Metalworking Team does not shy away from any casting assignment, even if the demands presented are challenging. The technology and know how to produce parts of consistently high quality amid the constantly changing state of the materials, temperatures and mold conditions, as well as the passionate spirit to take on any challenge, have spread to Yamaha s global manufacturing bases and are now contributing every day to help build products that rev customer hearts around the world. Ryoko Ota Communication Planning Group, Corporate Communication Division, Yamaha Motor Co., Ltd. 2500 Shingai, Iwata, Shizuoka, 438-8501 Japan TEL. 0538-32-1145 FAX. 0538-37-4250 E-mail: ootar@yamaha-motor.co.jp *Prior to any use of the article(s) and photographs contained within this newsletter, please contact me. Yamaha Motor Monthly Newsletter 5