「全日本製造業コマ大戦」を制したZION

ptember

[From September Issue 2013]

Shion Limited Company

From precision parts used for airplanes and cars, to fountain pen nibs, Shion Limited Company in Mino City, Gifu Prefecture manufactures a variety of metal items. Particularly in the case of parts made for aircrafts and automobiles, it’s necessary to use specialized equipment that can only be operated by highly skilled technicians.

Drawing on their technological knowhow, the firm has produced a spinning top that can be spun on a fingertip. The spinning top was originally made not to be sold, but to be entered into the All-Japan Manufacturing Industry Spinning Top Battle. Coming top out of 200 participating companies, the company won the second ever contest held in February. On display in the entrance to their factory are the “spoils of war,” i.e. the spinning tops of conquered opponents.

The All-Japan Manufacturing Industry Spinning Top Battle is held so that small businesses, which make up the majority of Japan’s manufacturing industry, can showcase their technological competence. As long as the top is 20 millimeters in diameter or less, there are no other restrictions on materials, weight or shape. Tops are pitted against each other in a “ring” made of synthetic resin which is 250 millimeters in circumference. The rule is that a top wins if it either nudges the other one out of the ring, or keeps spinning for longer – even if it’s just by one second.

The company’s winning top “Zion” was chosen from over 100 prototypes. It was refined during in-house contests and regional trials. “The night before the final, I practiced spinning the top so much that the fingerprints on my right thumb and index finger were rubbed smooth,” says president YAMADA Ken, reminiscing about the intensity of the battle.

Zion is 19.8 millimeters in diameter. Characterized by its heft and low center of gravity, the top was made from durable metals like heavy alloy and tungsten, and is extremely tough. Speaking about the manufacturing difficulties they encountered, Yamada said: “We made holes to make the center lighter and made the tip slippery so that it wouldn’t get caught on the edge of the ring. Also we did our utmost to design a shape that would keep spinning for as long as possible.”

Zion not only has an unusual shape. An extremely thin substance – of a thickness of only 0.05 millimeters – called “skin gel,” has been applied to its outer edge. Because skin gel halts an opponent’s spinning top, any contact works in Zion’s favor. As long as the top meets the requirement of being 20 millimeters or less in diameter, it’s not against the rules.

“It’s easy to do projects that have predetermined production techniques and materials, but it’s not much fun. In this way, making spinning tops offers us the perfect opportunity to indulge in our enthusiasm for craftsmanship, as we’re involved in every step of the process, from brainstorming and designing, to producing and experimenting. Through this experience, many employees have come to realize that manufacturing is enjoyable and have become prouder of what they do,” said Yamada, who believes that the contest was also useful for employee education.

Shion Limited Company

Text: ITO Koichi

 

[2013年9月号掲載記事]

有限会社シオン

岐阜県美濃市にある金属製品製造業、有限会社シオンは航空機や自動車に使われる精密部品から万年筆の軸まで、さまざまな製品の加工を手がけています。特に、航空機や自動車に使われる部品は正確な加工ができる設備と、それを使いこなすための極めて高い技術力が求められます。

そんな同社の技術力を集めて作られたのが、指先でひねってくるくる回すおもちゃのコマです。このコマはもともと売るためではなく「全日本製造業コマ大戦」というイベントに出場するために作られたものです。同社は今年2月の第2回大会で優勝し、参加200社の頂点に立ちました。工場の入り口には戦利品として敗戦者のコマが展示されています。

全日本製造業コマ大戦は日本の製造業のほとんどを占める中小企業の技術力をアピールするために開かれます。「直径20ミリ以下」という条件を満たしていれば、材質や重さ、形などは自由です。それを合成樹脂でできた直径250ミリの「土俵」で戦わせます。相手を土俵の外に弾き飛ばすか、相手より1秒でも長く回り続けたほうが勝ちというルールです。

優勝したコマ「ZION」は、100種類以上の試作品から選び抜かれたもの。社内大会や地方予選を重ねて磨きをかけられました。「決勝戦の前の夜には、コマを回す練習をしすぎて右手の親指と人差し指の指紋がつるつるになっていました」と、社長の山田健さんは戦いの激しさを振り返ります。

ZIONは直径19.8ミリ。とてもかたく、重い金属のヘビーアロイやタングステンを使っており、ずっしりとした重みと低い重心が特徴です。「中心部が軽くなるように穴をあけ、土俵のくぼみで足を取られないよう先端部はすべりやすくしました。また、できるだけ長く回り続けるような形に仕上げるのに苦心しました」と山田さんは製作時の苦労を明かします。

ZIONの特徴は見た目ばかりではありません。厚さ0.05ミリという非常に薄い「人肌ゲル」という素材を外周に塗ってあることです。人肌ゲルには相手のコマの動きを止める効果があるので、接触すると試合を有利に運ぶことができます。直径20ミリ以下という条件を満たしているので違反ではありません。

「作り方も材料もはじめから決まっている仕事は簡単ですが楽しくはありません。その点、発案から設計、製作、実戦までのすべてに関わるコマ作りは、ものづくりの面白さを味わえる絶好の機会。この経験を通じて製造業の楽しさと誇りを覚えた社員が多かったのではないでしょうか」。山田さんは大会が社員教育にも役立ったと考えています。

有限会社シオン

文:伊藤公一

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