本文選題：微機(jī)電系統(tǒng) + 微直線位移機(jī)構(gòu)�。� 參考：《上海大學(xué)》2015年博士論文

【摘要】：微位移機(jī)構(gòu)是微機(jī)電系統(tǒng)(Microelectromechanical System,MEMS)的重要組成部分,承擔(dān)微系統(tǒng)中運(yùn)動和力的傳遞功能。微位移機(jī)構(gòu)以致動器為動力源,經(jīng)微杠桿、微齒輪或微棘輪等組件實現(xiàn)運(yùn)動或動力傳遞。線性微直線位移機(jī)構(gòu)可將致動器產(chǎn)生的微位移累積放大后輸出。本課題針對微位移機(jī)構(gòu),開展了微位移機(jī)構(gòu)的驅(qū)動機(jī)理、實驗測試、理論建模和性能分析等方面的研究工作。完成的主要研究內(nèi)容和成果如下:建立了電熱致動器的瞬態(tài)溫度分析模型和力學(xué)模型,利用有限差分法計算了致動器的瞬態(tài)溫度,求解并實測了致動器在不同驅(qū)動條件下的輸出位移,結(jié)果表明模型計算結(jié)果和實測結(jié)果一致。在充分了解MEMS加工方法和Poly MUMPs代工工藝特有設(shè)計方法的基礎(chǔ)上,結(jié)合課題研究內(nèi)容,設(shè)計了幾類典型的摩擦式、嚙合式微位移機(jī)構(gòu),并討論了此類微機(jī)構(gòu)設(shè)計時應(yīng)重點(diǎn)考慮的相關(guān)問題和注意事項。建立了一套可行的微位移機(jī)構(gòu)運(yùn)動測試系統(tǒng),通過對電熱驅(qū)動摩擦式微位移機(jī)構(gòu)的多次測試,獲得了它們的相關(guān)運(yùn)動參數(shù)。∏型約束和T型約束摩擦式微直線位移機(jī)構(gòu)在不同驅(qū)動條件下實現(xiàn)了前推運(yùn)動和后拉運(yùn)動。頻率對微直線位移機(jī)構(gòu)的運(yùn)動速度有影響,滑桿的速度隨致動頻率的增大而增大。設(shè)計制作的多種嚙合式微位移機(jī)構(gòu)經(jīng)試驗測試表明部分實現(xiàn)了預(yù)定功能,但性能尚待提高。建立了摩擦式微直線位移機(jī)構(gòu)的運(yùn)動分析模型,推導(dǎo)出了致動單元和滑桿的運(yùn)動表達(dá)式,全面分析了驅(qū)動頭和滑桿的相對運(yùn)動以及滑桿僅在一組致動器驅(qū)動下即可產(chǎn)生前推和后拉兩個方向運(yùn)動的機(jī)理,同時分析了驅(qū)動條件和結(jié)構(gòu)參數(shù)對滑桿運(yùn)動方向的影響。實測了滑桿在不同驅(qū)動頻率下的前推和后拉位移,實測與理論結(jié)果一致。理論分析表明,不同結(jié)構(gòu)參數(shù)的摩擦式微直線位移機(jī)構(gòu),通過調(diào)節(jié)驅(qū)動頻率,可改變滑桿的運(yùn)動方向,致動單元的剛度和質(zhì)量直接影響滑桿的運(yùn)動形式。理論分析和實驗證明用一組驅(qū)動實現(xiàn)滑桿的雙向運(yùn)動是可行的。針對典型微位移機(jī)構(gòu),從設(shè)計和使用兩個方面分析了微位移機(jī)構(gòu)的主要失效形式,設(shè)計階段的失效主要來源于版圖錯誤和違反設(shè)計規(guī)則而引起器件的功能失效,使用階段的失效形式重點(diǎn)研究了致動器在交變溫度載荷作用下的熱疲勞失效。對微傳動系統(tǒng)的設(shè)計提出了建議,并提出了改善微位移機(jī)構(gòu)傳動特性、提高其可靠性的措施。針對電熱致動器在交流電作用下承受交變溫度載荷而發(fā)生熱疲勞失效的現(xiàn)象,分析了熱疲勞失效機(jī)理。溫度和應(yīng)力計算表明,結(jié)構(gòu)形式和施加的電壓直接影響致動器的溫度分布和應(yīng)力大小,因最大應(yīng)力小于屈服強(qiáng)度極限而不會發(fā)生應(yīng)力引起的疲勞失效。測試了交流電作用下致動位移和循環(huán)次數(shù)的關(guān)系,實驗結(jié)果和理論計算表明:溫度低于脆性-韌性轉(zhuǎn)換溫度,電熱致動器不發(fā)生熱疲勞失效,否則在長期循環(huán)后會發(fā)生熱疲勞失效。300~600℃的溫度對電熱致動器的工作最有利,在此溫度范圍內(nèi)能夠精確穩(wěn)定地提供數(shù)千萬次的致動循環(huán)。最后根據(jù)失效現(xiàn)象,分析了熱疲勞失效機(jī)理,得出高溫變形是引發(fā)熱疲勞失效的直接原因。
[Abstract]:Micro displacement mechanism is an important part of Microelectromechanical System (MEMS). It bears the transmission function of motion and force in the micro system. Micro displacement mechanism so that the actuator is a power source, through micro lever, microgear or micro ratchet and other components to achieve motion or power transfer. Linear micro linear displacement mechanism can produce the actuator. In this paper, the driving mechanism of micro displacement mechanism, experimental test, theoretical modeling and performance analysis are carried out for micro displacement mechanism. The main research contents and results are as follows: the transient temperature analysis model and mechanical model of the electrothermal actuator are established, and the finite difference method is used. The transient temperature of the actuator is calculated and the output displacement of the actuator under different driving conditions is calculated and measured. The results show that the calculated results are in agreement with the measured results. On the basis of fully understanding the MEMS processing method and the special design method of the Poly MUMPs process, several types of typical friction formulas are designed. The meshing micro displacement mechanism is discussed and the related problems and attention should be considered in the design of such micromechanism. A set of feasible motion testing system for micro displacement mechanism is set up. By many tests of the micro displacement mechanism of the electric heat driven friction mechanism, the relative motion parameters of the micro displacement mechanism are obtained. The forward motion and back pull motion of the micro linear displacement mechanism are realized under different driving conditions. The frequency has an influence on the motion speed of the micro linear displacement mechanism, and the speed of the sliding rod increases with the increase of the frequency of the actuation. The experimental test shows that the predetermined function has been realized in some kinds of meshing micro displacement mechanism designed and produced, but the performance is still to be raised. The motion analysis model of the frictional micro linear displacement mechanism is set up, the motion expression of the actuating unit and the sliding rod is derived, the relative motion of the driving head and the sliding rod, and the mechanism of the two directions that the sliding rod is driven by a set of actuators only driven by a set of actuators are analyzed. The driving conditions and the structure are also analyzed. The effect of the parameters on the direction of the sliding rod motion. The forward and back pull displacement of the sliding rod at different driving frequencies is measured. The measured results are in agreement with the theoretical results. The theoretical analysis shows that the frictional micro linear displacement mechanism with different structural parameters can change the direction of the movement of the sliding rod by adjusting the driving frequency and direct influence of the stiffness and mass of the actuating unit. The theoretical analysis and experiment show that it is feasible to use a group of driving forces to realize the two-way motion of the sliding rod. According to the typical micro displacement mechanism, the main failure forms of the micro displacement mechanism are analyzed from two aspects of design and use. The failure of the design stage is mainly due to the error of the layout and the violation of the design rules. The thermal fatigue failure of the actuator under the alternating temperature load is emphatically studied in the failure mode of the use stage. The design of the micro transmission system is proposed, and the measures to improve the transmission characteristics and improve the reliability of the micro displacement mechanism are put forward. The mechanism of thermal fatigue failure was analyzed. The temperature and stress calculation showed that the structure form and the applied voltage directly affected the temperature distribution and stress size of the actuator, because the maximum stress was less than the yield strength limit and the stress induced fatigue inefficiency. The dynamic displacement and cycle under alternating current were tested. The relationship of the times, the experimental results and the theoretical calculation show that the temperature is lower than the brittle ductile transition temperature, and the thermal fatigue failure of the electrothermal actuator does not occur. Otherwise, the thermal fatigue failure at.300~600 C after a long cycle is most favorable to the work of the electrothermal actuator, which can provide a precise and stable supply of tens of millions of times in this temperature range. Finally, according to the failure phenomenon, the failure mechanism of thermal fatigue is analyzed. It is concluded that high temperature deformation is the direct cause of thermal fatigue failure.
【學(xué)位授予單位】：上海大學(xué)
【學(xué)位級別】：博士
【學(xué)位授予年份】：2015
【分類號】：TH-39
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本文編號：1960215