本文關鍵詞： BTA 渦動 應變傳感器 模糊模型 Simulink　出處：《中北大學》2017年碩士論文　論文類型：學位論文

【摘要】：生產(chǎn)技術發(fā)展迅速的今天,深孔加工技術更多的應用于航天、兵器、高鐵等高精度要求的制造中。但是,深孔加工由于其長徑比大的原因,在加工過程中,鉆桿存在著主動振動和旋轉的渦動,這些現(xiàn)象破壞被加工孔的表面質量,如:表面光潔度、幾何尺寸和公差等。由此,可知深孔加工是機械制造行業(yè)中工藝最為復雜、價格最為昂貴的鉆孔工藝。本文針對BTA深孔加工過程中鉆桿-工件的渦動現(xiàn)象,進行了以下幾方面的工作:基于流體動壓潤滑理論和梁的固有振動方程,建立了鉆桿-工件系統(tǒng)橫向振動方程,并考慮高壓切削液對鉆桿加工段的擾動,完善了鉆桿-工件系統(tǒng)橫向振動微分方程,最后依據(jù)振動理論的求解方法對動力學微分方程進行了求解,該微分方程中包含一對控制激勵。設計了基于應變傳感器的鉆桿橫向位移檢測裝置,設計了三個實驗:實驗一,在鉆桿自由旋轉的情況下對鉆桿的橫向位移進行測量。實驗二,在鉆孔的初始階段對鉆桿的橫向位移進行測量,并繪制出了鉆桿在不同轉速下的中心軌跡圖。實驗三,設置不同的轉速、進給量、切削液流量進行鉆孔,并對被加工孔件進行直線度、表面粗糙度測量。依據(jù)實驗三測得的直線度和表面粗糙度進行誤差計算,提出了用模糊邏輯模型進行的離線操作模型,該模型可用來測量實驗中獲得的結果,且可預測所需獲得表面質量的最佳切削參數(shù)組合。根據(jù)運動微分方程,運用MATLAB/Simulink軟件建立仿真控制模型,給出了在不同控制位置,以及不同控制激勵下鉆桿的渦動特性。研究結果表明:BTA深孔加工中的鉆桿受多方面影響而發(fā)生渦動、橫向振動,基于應變位移傳感器的橫向位移測量裝置可以準確的測量鉆桿的橫向位移,所繪制的鉆桿中心軌跡圖可以反映出數(shù)學模型的正確性。基于模糊邏輯的離線操作模型可以很好的預測所需獲得表面質量的最佳切削參數(shù)組合。在某一轉速下,外界控制激勵的位置不同、激勵類型不同,都會對鉆桿的渦動抑制效果產(chǎn)生不同的影響。因此,本文較為詳盡的對鉆桿的渦動現(xiàn)象進行了闡述,并提出了相應的控制方法,具有實際意義。
[Abstract]:With the rapid development of production technology, deep hole processing technology is more used in aerospace, weapons, high-speed iron and other high-precision manufacturing. However, deep hole processing because of its large aspect ratio, in the process of processing. There are active vibration and whirling of drill pipe, which destroy the surface quality of the machined hole, such as surface finish, geometric dimension and tolerance. Deep hole machining is the most complicated and expensive drilling technology in mechanical manufacturing industry. This paper aims at the vortex phenomenon of drill pipe and workpiece in the process of BTA deep hole machining. Based on the hydrodynamic lubrication theory and the inherent vibration equation of the beam, the transverse vibration equation of the drill pipe and workpiece system is established, and the disturbance of the high pressure cutting fluid to the drill pipe machining section is considered. The differential equation of lateral vibration of drill pipe and workpiece system is improved. Finally, the dynamic differential equation is solved according to the vibration theory. The differential equation includes a pair of control excitations. A drill pipe lateral displacement detecting device based on strain sensor is designed. Three experiments are designed: experiment 1. The lateral displacement of drill pipe is measured under the condition of free rotation of drill pipe. In experiment two, the lateral displacement of drill pipe is measured in the initial stage of drilling. The center track diagram of drill pipe under different rotating speed is drawn. Experiment 3, set different rotation speed, feed rate, cutting fluid flow rate to drill hole, and carry on straightness to the processed hole parts. Surface roughness measurement. Based on the error calculation of straightness and surface roughness measured in experiment 3, an off-line operation model based on fuzzy logic model is proposed, which can be used to measure the results obtained in the experiment. According to the motion differential equation, the simulation control model is established by using MATLAB/Simulink software, and the different control positions are given. As well as the vortex characteristics of drill pipe under different control excitation. The results show that the drill pipe in the deep hole machining of BTA is affected by many aspects of vortex and lateral vibration. The lateral displacement measurement device based on strain displacement sensor can accurately measure the lateral displacement of drill pipe. The trajectory diagram of drill pipe center can reflect the correctness of mathematical model. The off-line operation model based on fuzzy logic can well predict the optimal cutting parameters combination of surface quality. Different positions of external excitation and different types of excitation will have different effects on the vortex suppression effect of drill pipe. Therefore, the vortex phenomenon of drill pipe is described in detail in this paper. The corresponding control method is put forward, which is of practical significance.
【學位授予單位】：中北大學
【學位級別】：碩士
【學位授予年份】：2017
【分類號】：TG523

【參考文獻】

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本文編號：1446831