機械設(shè)計制造復(fù)習-wenkub
2024-11-09 06 本頁面
【正文】 要素：切削速度，(進給速度)進給量，背吃刀量。陶瓷材料：強度高，耐磨性好，抗彎強度和沖擊韌度低。第二變形區(qū)：切屑開始同材料基體相分離，在沿刀具前刀面流出，還將受到前刀面的擠壓和摩擦，使切屑進一步產(chǎn)生滑移變形。對切削過程的影響：，切削能力降低。減小加工硬化傾向。P40 Fp對加工質(zhì)量有何影響？FP易使工件變形和產(chǎn)生振動。影響因素：。材料強度硬度高，主偏角角小。：良好的冷卻切削液。P129 主參數(shù)的含義及常見機床的主參數(shù)是什么？主參數(shù)：反映機床最大工作能力的一個主要參數(shù)，它直接影響機床的其他參數(shù)和結(jié)構(gòu)的大小。分為：定位基準，測量基準，裝配基準，工序基準。（詳細看書）P208209獲得尺寸精度、形狀精度、位置精度的方法有哪些？（1）零件獲得尺寸精度的方法：試切法、定尺寸刀具法、調(diào)整法、自動控制法。影響因素： P224240 工藝系統(tǒng)的受力、受熱變形對加工精度的影響及減小受力、受熱變形的措施？ ，材料硬度變化導(dǎo)致切削力大小變化引起的加工誤差——誤差復(fù)映減小工藝系統(tǒng)受力變形的措施主要有：一是提高工件加工時的剛度；二是提高工件安裝時的夾緊剛度；三是提高機床部件的剛度。P241加工誤差的性質(zhì)加工誤差：系統(tǒng)誤差，隨機誤差P245250加工誤差的統(tǒng)計分析P260261影響加工后表面粗糙度的因素（刀具的形狀，幾何角度，進給量，刀刃的粗糙度）（工件材料，切削速度，進給量）（，材料，）B磨削加工 （砂輪的粒度，硬度，組織，材料，修整及旋轉(zhuǎn)質(zhì)量的平衡）（砂輪速度，工件速度，進給量，磨削深度，空走刀數(shù)）P265266減小表面粗糙度值的加工方法 P284286 基本概念：工序、安裝、工位、工步、走刀（1）工序是指一個（或一組）工人，在一臺機床上（或一個工作地點），對同一工件（或同時對幾個工件）所連續(xù)完成的那部分工藝過程。（5）工位：為了完成一定的工序部分，一次裝夾工件后，工件與夾具或設(shè)備的可動部分一起相對刀具或設(shè)備的固定部分所占據(jù)的每一個位置。3設(shè)法降低制造成本。3擬定工藝路線，選擇定位基準。7確定各工序的加工余量，計算工序尺寸和公差。11填寫工藝文件。4選定位夾緊可靠的平面做粗基準。4互為基準。4光整加工階段。4合理使用機床。（2）工序分散：特點：1機床裝備調(diào)整容易2對工人技術(shù)要求低3生產(chǎn)準備工作量小4容易變換產(chǎn)品5設(shè)備數(shù)量多，工人數(shù)量多，生產(chǎn)面積大。P314/P315工序余量的概念及影響工序余量的因素有哪些？工序余量：指相鄰兩工序的工序尺寸之差，也就是在一道工序中所切除的金屬層厚度。這種由于帶的彈性變形而引起的帶與帶輪間的微量滑動，成為帶傳動的彈性滑動。、鏈條鉸鏈的磨損、鏈條鉸鏈的膠合、鏈條的靜力破壞。tolerate only minimal deflections to maintain precision cuts．Consequently, bearings are manufactured with low NRR just for machinetool applications．Contamination is unavoidable in many industrial products，and shields and seals are monly used to protect bearings from dust and dirt．However，a perfect bearing seal is not possible because of the movement between inner and outer races．Consequently，lubrication migration and contamination are always problems．Once a bearing is contaminated, its lubricant deteriorates and operation bees noisier．If it overheats，the bearing can seize．At the very least，contamination causes wear as it works between balls and the raceway，being imbedded in the races and acting as an abrasive between metal surfaces．Fending off dirt with seals and shields illustrates some methods for controlling contamination．Noise is as an indicator of bearing quality．Various noise grades have been developed to classify bearing performance capabilities．Noise analysis is done with an Anderonmeter, which is used for quality control in bearing production and also when failed bearings are returned for transducer is attached to the outer ring and the inner race is turned at 1,800rpm on an air is measured in andirons, which represent ball displacement in μm/ experience, inspectors can identify the smallest flaw from their , for example, makes an irregular scratches make a consistent popping and are the most difficult to damag
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