一種機械式類快刀伺服裝置的設計研究

Abstract

本研究旨在以低成本開發一「機械式類快刀伺服裝置」，規劃應用於「精微CNC類快刀伺服工具機」上，並以「快速點墨」、「快刀切削」及「快速點膠」等三種不同製程技術，對伺服系統裝置進行驗證。首先，本研究提出連桿式、偏心凸輪、斜盤凸輪及橢圓凸輪等四種驅動機構的設計，並進行動力學分析與評估，發現橢圓凸輪驅動設計具低振動、高加速度及雙倍驅動頻率等優勢，故以此進行類快刀伺服裝置之硬體設計。類快刀伺服系統裝置以有限元素法，進行干涉檢查與結構分析，再結合三軸向位移平台，建構一低重心高勁性的「精微CNC類快刀伺服工具機」。在點墨驗證方面，實驗顯示，在驅動頻率22 Hz、進給速度600 mm/min以及30 µm的墨頭進給深度條件下，類快刀伺服工具機可在5×5 mm2面積內，提供連續及穩定的供墨，並快速點出10×11個陣列墨點，所耗時間僅5秒；在陣列微坑成型技術開發方面，搭配自行設計的含硼聚晶鑽石刀具，在切削速度600 mm/min，22 Hz驅動頻率條件下，類快刀伺服工具機可在2×2 mm2面積內，快速加工出5×7高密度陣列微坑特徵結構，位置重現精度可控制於26 µm以內；在材料結合方面，配合自行設計的氣壓式微點膠泵，類快刀伺服工具機也能精密且高效率地支援點膠工作，實驗結果顯示，在驅動頻率6 Hz，進給速度300 mm/min及4 kg/cm2的氣體壓力下，氣壓式微點膠泵能提供聚醋酸乙烯脂連續且穩定的吐膠，使類快刀伺服工具機能在3×3 mm2面積內，成功塗佈出3×5膠體特徵結構。研究顯示，所開發的精微CNC類快刀伺服工具機著實能成功應用於高密度且一致性微結構的快速製造，「快速點墨」、「快刀切削」及「快速點膠」之製程，符合多項產業應用需求，深具商化價值。This paper presents the development and application of a mechanically quasi-fast tool servo device. The developed quasi-Fast Tool Servo (quasi-FTS) is mounted onto a designed high-stiffness tabletop horizontal CNC machine system to verify the feasibility for the processes of fast inking, fast tool cutting and fast dispensing. First, four kinds of different driven designs involving linkage-, eccentric cam-, swash-plate cam- and oval cam- mechanisms are devised and analyzed. Due to the symmetry design and the superiority of double-speed response, the oval cam driven can improve the system vibration of the mechanically quasi-FTS device and allow a high acceleration motion. By combining the oval cam device and there axis stages, the high-stiffness tabletop horizontal CNC machine tool system with low-gravity design is successfully constructed in this study. Finite Element Analysis (FEA) is conducted on the deformation and resonant frequency of the developed machine system. In fast inking process, experimental results indicate that 10×11 microarray inks can be shown in the area of 5×5 mm2 at driving frequency of 22 Hz, feeding speed of 600 mm/min, feeding depth of 30 µm, and the process time is only 5 seconds. In fast tool cutting process, by combining the designed boron-doped polycrystalline composite diamond (BD-PCD) tool, a 5×7 micro dimple array can be quickly finished in the area of 2×2 mm2 at driving frequency of 22 Hz, cutting speed of 600 mm/min, cutting depth of 30 µm, and the process time is only 2 seconds. Also, the positional repeatability of the micro dimple array can be achieved within 26 µm. In fast dispensing process, by applying the home-made dispensing pump, a 3×5 micro colloid array is favorably formed in the area of 3×3 mm2 at driving frequency of 6 Hz, feeding speed of 300 mm/min, air pressure of 4 kg/cm2. Whole experimental results demonstrate that the developed mechanically quasi-FTS machine tool can really be employed in the manufacturing for high-density consistent microstructure array. It is rapid, cost effective, easily controllable, and worthy of commercialization.