Summary

近代の橋は一般に梁構造を使用し、その中でクレーンは前もって組み立てられた橋の部分構造物をペアのサポート柱に乗せます。多数の頑丈な油圧シリンダーが各部分構造物のエンドを支え、最終位置合わせの前に正確な高さ調整ができます。エンジニアは各シリンダーの位置を正確に検出する頑丈なセンサを要求します。センサは機械的に頑丈でなければならず、また過酷な屋外環境に耐えなければなりません。

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ユーザー利点

  • シンプルなセンサシステムがマニュアルによるチェックを削除
  • 長い検出距離なので非接触で正確な動作
  • 汚染に耐える強固な構造

製品特徴

  • 小型センサなのに22mmの検出距離
  • 厳しい作動環境への高い耐性

Customer Application

A specialist lifting company based in Switzerland uses heavy-duty hydraulic cylinder-jacks to position prefabricated bridge sections during roadway construction. A single section requires up to 20 jacks for accurate positioning; each has a capacity up to 1,000 tons with a stroke up to 30mm (1.25 in). Site conditions are harsh; cylinders are exposed to water, mud and dirt, and may also be subject to mechanical shock and vibration.The company requires rugged sensors that operate reliably and accurately in the demanding environment. Historically, engineers checked the position of each cylinder manually; this was both time-consuming and subject to human error. Previously trialed sensors were insufficiently robust, necessitating frequent adjustment or replacement, and had inadequate sensing distances.A simple, contactless system must provide fit-and-forget operation with extended maintenance intervals. Sensors must be mechanically robust and must withstand prolonged exposure to the harsh outdoor conditions of a construction site. An industry-standard interface is highly desirable to avoid the need for specialized control systems.

Customer Solution

Rugged Extra-Distance inductive sensors from the Contrinex Basic range are ideal for this application. Highly reliable and rated to IP67, these units are robust and accurate. A one-piece M30-diameter chrome-plated brass body with PBTP sensing face and vacuum-encapsulated electronics make this device well suited to the hostile environment, and the sensing distance of 22mm allows fully contactless operation.On each jack, a single sensor is fitted on a metal bracket that is welded to the side of the cylinder; a bearing plate, mounted on the end of the ram, distributes the load onto the bridge section. During operation, the ram extends, lifting the section; when it reaches the desired height, the sensor detects the position of a small metal target mounted on the bearing plate, halting the ram.The sensor is configured with an industry-standard PNP normally-open interface, and connection to the jack’s hydraulic control system is via an integral M12 connector and PVC-sheathed cable; this allows easy removal and replacement during routine maintenance. The sensor is impervious to water ingress, mud and dirt; reliability has been excellent. Contrinex inductive sensors deliver a cost-effective solution that satisfies the customer’s requirements for a simple, fit-and-forget system.