以雷射加工仿製鏟花表面特徵之研究

Abstract

滑動機構中的硬軌為重負載與重切削的工具機常採用之進給系統軌道，通常會在軌道的接觸面進行鏟花以便運動時使潤滑油進入接觸面以改善摩擦特性，但長期以來鏟花技術都依賴人工的方式完成，使得鏟花品質較難達到一致性得效果，無法有效掌控進給系統在滑動時之性能。本研究探討以雷射加工方式仿製人工鏟花之紋理，在滑動面上達到類似鏟花的效果，加工後並實際架設於進給平台量測其摩擦性能，驗證其效果。 本研究首先利用白光干涉儀拍攝人工鏟花面的主要形貌與特徵，並進一步分析其紋理特徵與形貌及輪廓，進一步將影像轉換成圖檔後利用雷射加工加工其形貌與輪廓，並與原人工鏟花紋理比對評估其相似性，更進一步將加雷射工之工件安裝摩擦測試平台進行摩擦量測，比較二者之摩擦特性表現。研究結果顯示，雷射加工之仿製紋理與原鏟花紋理之形貌均方根誤差(RMSE)在解析度512*512 points/mm^2下平均為10.39 µm/point，而其摩擦性能與原人工鏟花面相同甚至較佳，顯示本研究之成果可取代部份機械產業之人工鏟花，以提升硬軌之品質穩定性。

Hard rails are often used as the sliding mechanism in precision machinery, in particular in heavy-duty machine tools. In such a mechanism, scraping is employed in order to provide lubricant between the sliding surfaces. However, as scraping is conducted manually and it is very difficult to control the quality of contact that introduces variations of motion and performance. In this research, we investigated the machining of surface texture, mimic to manual scraping, by laser machining and compared the machining surface against the original manual scraping surface in both texture/profile error and their friction performance to verify the results. Surface texture of the manual scraped block is first measured using a surface profiler and geometric features of scraping marks are then analyzed. The surface texture is then transformed to a profile suitable for laser machining. The machined surface is then measured using the same profiler and sliding friction of both surfaces are tested under the same condition. The results showed that (i) The RMSE profile/texture error between the two surfaces is 10.39 µm/point under a 512*512 points/mm^2 measured resolution. (ii) The friction coefficient of the laser-machined block is better than that of the manual-scraped block. The results indicated that laser machining can be employed for surface scraping to improve the repeatability and quality of scraping.