A high-speed iron nut and a small factory of 45 people

2021-03-23 14:16:45 admin

A high-speed iron nut and a small factory of 45 people


As we all know, our country’s high-speed rail has achieved impressive results in the world. However, the small nuts have to be imported, that is, the small company with only 45 employees in Japan’s Hard Lock Industry Co., Ltd. Loose nuts. Many Japanese companies have precision machining technologies that seem simple but can't be learned. The nut used in China's high-speed rail is one of them. Hardlock company has published the principles on its website. It seems simple, but no company can learn it. What's the reason? When the high-speed rail is in operation, the high-speed train and the rail are in constant contact, and the resulting vibration is very large, and the general screws will be loosened and flew in this kind of vibration. If you don't want to be shocked, then you need screws and nuts to buckle tightly and never loosen. This requirement seems simple, but it is not easy to meet it. You think there are so many companies in the world that make screws and nuts, but how many companies can produce such nuts that never loosen? There is only one. This is Hadlock Industry Co., Ltd.

Japan's proud high-speed railway "Shinkansen". Twenty thousand screws were used on the train composed of 16 cars. When traveling at a speed of 250 kilometers per hour, if the nuts of the fixing screws become loose, causing important devices to fall off, a major accident will occur. In order to avoid accidents, it must be checked and re-tightened from time to time, which requires unimaginable manpower and expense. Katsuhiko Wakabayashi, the general manager of Hard Lock Industries (Higashiosaka City), invented the "Hard Lock Nut" that will never loosen. It firmly and reliably supports the safe driving of the Shinkansen with its low cost.

 The concept of "Hard Lock Nut" is very simple, that is, a wedge is inserted between the nut and the screw to prevent loosening. However, it is neither efficient nor realistic if the wedges are pushed into the nuts to be used one by one at the construction site. How can the nut have the function of a wedge? Wakabayashi thought hard.

The method he thought of was to use two kinds of nuts in the shape of "concave" and "convex" on a screw. The convex nut underneath, the center is slightly shifted during machining (off-centre machining), which acts as a wedge. The nut with a concave shape on the top is not processed off-center (round processing), thus forming the function of a hammer to beat a wedge. By combining these two nuts into one, the loosening problem is solved.

 The "Hard Lock Nut" was adopted by a large private railway company in Kansai, Japan in 1976, specifically for use in power equipment, and the business has developed rapidly since then. In the NAS (National Aerospace Standards) vibration test which is considered to be the most stringent in the world, the "Hard Lock Nut" also showed extraordinary results. Although the price is 4 to 5 times higher than that of ordinary nuts, once tightened, there is no need for maintenance, which can save huge maintenance and repair costs. So far, "Hard Lock Nuts" have been adopted by railways in Australia, Britain, Poland, China, and South Korea. Taiwan's Shinkansen (Taiwan High Speed Rail) has also maintained a record of no accidents since its opening. The BBC (British Broadcasting Corporation) introduced the effectiveness of the "Hard Lock Nut" in a documentary program verifying the railway accident that occurred in the UK in 2006. After that, the country's railway department made a decisive decision and introduced the "Hard Lock Nut" in an all-round way. In addition to railways, Japan’s Akashi Kaikyo Bridge, the world’s longest suspension bridge, Tokyo Sky Tree, the world’s tallest self-supporting radio tower, the space shuttle launch pad of the United States, and ocean drilling rigs, have adopted many domestic and foreign countries and regions. "Hard Lock Nut"

Inventor Wakabayashi is still immersed in technological innovation when the "Hard Lock nut" has become famous all over the world. He has successively developed new products such as the "single nut" to improve operation efficiency and the "special bearing nut" to prevent the loosening of the bearing. In addition, they are currently negotiating with the world's largest aircraft manufacturer Boeing in the United States and Rolls-Royce in Europe to develop lightweight products for aircraft.

Technology knows no borders, and the creative spirit of the Japanese inventor Wakabayashi is worthy of our peers in all precision machining fields to learn from.