NAGAIの技術|群馬県高崎市の切削加工、タービンブレード「株式会社長井精機」

TECHNOLOGY

切削加工

50番テーパ使用で難削材の高精度&スピード加工を実現

タービンブレードは、水蒸気やガスのエネルギーを回転運動に変換して電気エネルギーを生み出す重要部品です。高温・高圧の極限環境において、高い効率や耐久性が求められることから、高硬度の難削材を1/100ミリ単位の精度で複雑な3次元曲面に加工していく必要があります。

長井精機では、最大の保持力を誇る50番テーパ主軸仕様のマシニングセンタを40台以上保有。ニッケル基の超合金であるインコネルをはじめナイモニックやハステロイ、チタンといった難削材を高精度かつスピーディに加工する技術を確立しています。

加工設備一覧

研磨加工

培った技能の伝承で、最高の技能者集団をめざしています

タービンブレードに求められる高精度は、マシニングセンタの性能だけで実現できるものではありません。最先端のマシンと、感性豊かな人間の“技能”の融合があってはじめて可能になるものです。だからこそ長井精機では、技能者の育成に全力で取り組んでいます。

製造部門においては、加工を担当する技能者1人ひとりがスキルを磨き、シビアに品質の造り込みを行っています。また、仕上げとなる研磨工程でも、表面粗さRa0.7をクリアする研磨加工のマイスターを養成。培った技能を先輩から後輩へと伝承し、最高の技能者集団を目指しています。

刃具の内製化

刃具の内製化で、品質・コスト・納期の全てに対応

高精度でハイクオリティな製品をいかに効率よく迅速に加工していくか。それは長井精機が長年にわたって追求し続けているテーマです。そのためには、最先端の加工マシンを設備することはもちろん、そのマシンの性能を最大限に引き出す治具や刃具が重要になってきます。

特に、硬度の高い難削材では、刃具の摩耗が非常に激しいものがあります。長井精機では、蓄積してきた技術ノウハウをもとに、加工ニーズにあった治具や刃具を内製化。摩耗した刃具についても、社内で研磨できる体制を構築することで、品質・コスト・納期の全てに世界最高水準で応えています。

受賞

国や県の各種表彰が、妥協を許さない技術力の証明

元気なモノ作り中小企業300社(2008年版)

高度なモノ作り技術により日本の国際競争力を支えている中小企業300社を広く国民に対して紹介するため経済産業省と中小企業庁が選定するものです。長井精機はニッチ分野に特化することで、他社にまねできない独創的かつ高度な技術を持つ企業として2008年版で選定されました。

IT推進モデル企業

ITを活用し業務の効率化や特色ある事業の創出、研究・発明・考案を行った企業を群馬県が選定するものです。長井精機は「加工プログラム開発による生産効率と生産量の向上」を理由に、平成15年度のIT推進モデル企業に選定されました。

中小企業モデル工場

県内の中小企業における経営のモデルと認められる適格工場を実例として選定するものです。長井精機では、たゆまぬ自己変革と企業体質の強化に努めてきた結果、1983年の初回指定以来20年以上にわたって指定され続けている数少ない企業になっています。

Difficult-to-Machine Materials, 3D Machining

Established technology to process 3D curves with difficult-to-machine materials at an accuracy of 1/100 mm

Turbine blades are important feather-shaped components that convert steam and gas energy into rotational movement to generate electric energy. Because the blades rotate at close to the speed of sound while receiving steam at high pressures and high temperatures of over 800℃, they must be extremely strong and precise. Furthermore, products must be cut and shaped from all 360 degrees to produce complex three-dimensional curves.
At Nagai Seiki, we have accumulated technology in blade machining that has led the industry for over half a century. Today, we have established machining technologies to cut and polish three-dimensional curves using special steels, which are rigid and difficult to grind, to an accuracy of 1/100 mm. High-precision machining of the Nickel-base superalloy “Inconel” is an example of our achievements.

Regeneration Polishing of Blade Tools

In-house production and polishing of blade tools to meet quality, cost, and delivery targets

How can we efficiently and speedily process products with complex shapes that require high precision? This is a technological challenge that Nagai Seiki has pursued for many years. To meet this challenge, we have installed the most-advanced processing machines, with jigs and blade tools becoming the key factors maximizing their performance. For example, about 15 blade tools are used for each product when machining attachment parts to mount a blade on a rotor. In addition, some wear quickly because the work involves grinding hard materials such as special stainless steels.
At Nagai Seiki, we use our accumulated technological expertise to produce jigs and blade tools in-house to meet machining needs. And, we have also trained engineers internally who are able to polish worn blade tools. We are committed to meeting the world’s highest standards in terms of quality, cost, and delivery targets.

The Best Team of Engineers

Aiming to become experts in polishing technologies with the best team of engineers

Turbine blades require the machining of complex three-dimensional curves at an accuracy of 1/100 mm. This high level of quality is achieved through a fusion of our machining centers and the most advanced machines, together with the acute sensitivity and skills of our people. That is why Nagai Seiki is fully committed to developing engineers.
Each and every engineer in our production division responsible for machining refines his skills to meet strict quality standards. Furthermore, experts in polishing technology are specially trained for the final polishing process. And, by ensuring that accumulated technologies are handed down to the next generation of engineers, we are committed to having the best team of engineers.

Quality

Reliable quality is ensured by the entire company working together to meet sophisticated customer needs

We are also actively engaged in improving the quality demanded for blade machining which greatly affects the power generation efficiency. This was the reason why we adopted a 3-dimensionsal coordinate measuring instrument manufactured by Carl Zeiss. We have established a setup for accurately checking whether or not the machined product falls within the tolerances demanded by the customer.
Another feature of NAGAISEIKI is that the one engineer who is in charge of machining incorporates high quality into the manufacturing process. In blade machining which demands high level cutting and grinding technology, the specifications cannot be met by merely relying on the machining ability of the machining center. We have added “skill” which is based on human sensibility, and by making concerted efforts we have realized high quality products.

Awards

National and prefectural awards show Nagai Seiki’s uncompromising technological strengths

300 Energetic Small to Medium-sized Manufacturers(2008 Edition)

The Ministry of Economy, Trade and Industry and the Small and Medium Enterprise Agency select 300 small to medium-sized companies that support Japan’s international competitiveness with their advanced manufacturing technologies, with the aim of introducing these companies to the public. Nagai Seiki was selected in the 2008 edition as a company specializing in a niche area with original and advanced technologies that cannot be copied by others.

Model Plant of Small to Medium-sized Companies

This program selects qualified factories that serve as models of management for small to medium-sized companies in the prefecture. As a result of Nagai Seiki’s continuous efforts toward self-innovation and enhancing its corporate strength, it is one of the few model companies that has been selected regularly for more than 20 years since the program began in 1983.

Model Company in IT Promotion

Model companies are selected by Gunma Prefecture to recognize operations using IT, and companies with distinctive business development, research, inventions, or designs. Nagai Seiki was selected as the Model Company for IT Promotion in 2003 after having “Enhanced production efficiency and output through the development of a machining program.”

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