製管成形之變形機制探討與下料帶寬尺寸優化

Abstract

金屬管件於工業中之用途廣泛，包括石油、天然氣輸送管與建築結構用管等。在製管成形中，輥軋成形製程(conventional roll forming process)為最常見之工法。然而，隨著製管業之技術不斷進步，成形機之開發與演化也隨之提升，從傳統輥軋成形機、籠式輥軋成形機，到如今具彈性功能之成形機(Flexible Forming Mill，簡稱FF成形機)已成為主流。 本論文針對傳統輥軋成形與FF成形進行深入比較，研究涵蓋了各成形道次的板帶應力分佈、厚度分佈以及逐站成形的帶寬變化，從而瞭解不同產線之成形特性和受力機制。從兩者之變形機制差異可知，傳統產線主要利用模具之上下輥輪壓縮板材成形，因此傳統產線於生產不同產品尺寸時，皆須更換模具；而FF成形主要利用輥位調整，使板材折彎成形，因此FF成形於生產不同產品尺寸時可共用模具。而FF成形共用尺寸模具之設計理念，也大幅減少了換模時間。 下料帶寬之設計於製管業中亦為相當重要的議題，一個正確的下料帶寬計算公式，可協助業界於實際生產時，減少多次試誤法之時間成本。因此，本論文針對FF成形之下料帶寬計算公式進行了修正與優化。首先透過有限元素模擬軟體進行分析，修正現今製管場常用之計算公式；接著探討輥位調整對帶寬於成形中之影響，並提出一套新的計算公式，該公式中包含本論文所定義之輥位調整參數；最終透過模具修改來改善粗成形段之板帶成形性。 經過上述之分析與探討，本論文透過模擬驗證、輥位調整及模具修改，建立了包含輥位參數之下料帶寬計算公式，利用此公式可以精準設計下料帶寬，減少帶寬設計過長之廢料，並且降低材料成本。本論文提出之優化方法不僅可改善板帶之成形性，亦可提升FF產線之生產品質與效率。

Metal pipes have a wide range of applications in industry, including petroleum and gas pipelines and construction structural pipes. In tube forming, the conventional roll forming process is the most common method. However, with the continuous advancement of pipe manufacturing technology, the development and evolution of forming machines have also progressed, from step roll forming mill and cage roll forming mill to the current mainstream flexible forming (FF) mill. This thesis conducts an in-depth comparison between conventional roll forming and flexible forming, covering the stress distribution, thickness distribution, and width variation of the strip at each forming pass. This analysis helps to understand the forming characteristics and stress mechanisms of different production lines. From deformation mechanisms, it can be seen that conventional production lines mainly use the upper and lower rollers to compress the sheet, necessitating roller changes for different product sizes. In contrast, FF forming primarily uses roller adjustments to bend the sheet metal, allowing for the use of shared roller dies when producing different product sizes. The design concept of shared size roller dies in FF forming significantly reduces die change time. The design of strip width is a crucial issue in the pipe manufacturing industry. A correct strip width calculation formula can help reduce the time cost of trial-and-error methods in actual production. Therefore, this thesis aims to correct and optimize the strip width calculation formula for FF forming. First, finite element simulation is used to analyze and correct the commonly used formulas in current pipe manufacturing plants. Then, the impact of roll position adjustment on strip width during forming is investigated, and an optimized calculation formula is proposed, including roll position adjustment parameters defined in this thesis. Finally, roller dies modifications are made to improve the forming quality of the strip in the roll forming stage. Through the above analysis and research, this thesis establishes a strip width calculation formula that includes roll position parameters through simulation verification, roll position adjustment, and roller dies modification. This formula enables precise design of strip width, reducing the waste of excessively long strip widths and lowering material costs. The optimization methods proposed in this thesis not only improve the forming quality of the strip but also enhance the production quality and efficiency of the FF production line.