【正文】 指導(dǎo)老師 楊晨 請您刪除一下內(nèi)容， O(∩ _∩ )O謝謝！?。?Many people have the same mixed feelings when planning a trip during Golden Week. With heaps of time, the sevenday Chinese National Day holiday could be the best occasion to enjoy a destination. However, it can also be the easiest way to ruin how you feel about a place and you may bee more fatigued after the holiday, due to battling the large crowds. During peak season, a dream about a place can turn to nightmare without careful planning, especially if you travel with children and older people. As most Chinese people will take the holiday to visit domestic tourist destinations, crowds and busy traffic are inevitable at most places. Also to be expected are increasing transport and acmodation prices, with the possibility that there will be no rooms available. It is also mon that you39。s misery, the cow told him to turn its hide into a pair of shoes after it died. The magic shoes whisked Niulang, who carried his two children in baskets strung from a shoulder pole, off on a chase after the empress. The pursuit enraged the empress, who took her hairpin and slashed it across the sky creating the Milky Way which separated husband from wife. But all was not lost as magpies, moved by their love and devotion, formed a bridge across the Milky Way to reunite the family. Even the Jade Emperor was touched, and allowed Niulang and Zhinu to meet once a year on the seventh night of the seventh month. This is how Qixi came to be. The festival can be traced back to the Han Dynasty (206 BCAD 220). Traditionally, people would look up at the sky and find a bright star in the constellation Aquila as well as the star Vega, which are identified as Niulang and Zhinu. The two stars shine on opposite sides of the Milky Way. Customs In bygone days, Qixi was not only a special day for lovers, but also for girls. It is also known as the Begging for Skills Festival or Daughters39。s Day! in shops, hotels and restaurants. But few young women will mark the festival with their boyfriends, or take part in traditional activities to pray for cleverness. 。s Day on February 14, characterized by bouquets of roses, chocolates and romantic candlelight dinners, than they do about their homegrown day for lovers. Even Qixi is nowadays referred to as the Chinese Valentine39。s largest virgin forest, and known for its spring and ecological environment, Arxan is marveled at by many tourists as the purest land on earth. You cannot miss out the Autumn of Arxan. It is definitely the best with brightlycolored scenery full of emotions. Autumn in the northern part of the country es earlier than the South. A September rain followed by the footprints of Autumn brings more colors to the once emerald green mountain and blooming grassland. Shutterbugs flock to see for themselves the marvel of splendid colors around the mountains and waters, many of whom have travel a long distance and even camp here only to capture a moment of the nature wonder. The silver birch turns golden, while the larch is still proudly green. You will find yourself drowned in the intoxicating red of the wild fruits as well as the glamour of flowers in full blown. And your heart will be lingering on the woods as it39。 [14] 吳宗澤 .機械零件設(shè)計手冊 .北京：機械工業(yè)出版社， 2020 [10] 陳榮林 .機械設(shè)計應(yīng)用 .北京：科學(xué)技術(shù) 文獻出版社， 1995 [5] 于春生 .數(shù)控編程及應(yīng)用 .北京 :高等教育出版社， 2020 [6] 胡鳳蘭 .互換性與技術(shù)測量基礎(chǔ) .北京：高等教育出版社， 階梯軸的工藝規(guī)程及工裝設(shè)計 24 參考文獻 [1] 張麗華等 .數(shù)控編程與加工技術(shù)基礎(chǔ)篇 .2 版 .大連：大連理工大學(xué)出版社 ,同時我們也體會到了團隊合作的重要性，要集思廣益才會讓設(shè)計更完美。在實際應(yīng)用中是要經(jīng)過多次調(diào)整才能達到預(yù)期效果，望各位老師批評指正。 N480 M05。 切斷工件 N440 G01 Z248。 F 的意思是螺紋導(dǎo)程 N350 G92 Z38 N360 G92 X46 Z38 N370 G92 Z38 N380 G00 X80 Z38。 N300 T0200。 N260 X45。 N220 T0202。 N180 X85 Z245。 N140 X80 Z116。 N90 Z1 N100 Z40。 N30 T0101。 階梯軸的工藝規(guī)程及工裝設(shè)計 16 將工件安裝好之后，先用 MDI 方式操作機床，用已選好的刀具將工件端面車一刀，然后保持刀具在縱向（ Z）尺寸不變，沿橫向（ x）退刀。工件右端加工：既先從右到左進行外輪廓粗車（留 余量精車），然后從右到左進行外輪廓精車，最后切槽；， 粗加工外輪廓、精加工外輪廓，切退刀槽，最后螺紋粗加工、螺紋精加工。由于半精加工和精加工的走刀路線是沿其零件輪廓順序進行的，所以確定走刀路線主要在于規(guī)劃好粗加工及空行程的走刀路線。 ④ 在同一次安裝中進行的多道工序，應(yīng)先安排對工件剛性破壞小的工序。 （ 7）工時在加 ,加工順序的安排應(yīng)根據(jù)零件 的結(jié)構(gòu)和毛坯狀況，以及定位夾緊的需要來考慮，重點是工件的剛性不被破壞。一般先加工平面、定位 面，后加工孔；先加工簡單的幾何形狀，再加工復(fù)雜的幾何形狀；先加工精度較低的部位，再加工精度要求較高的部位。 （ 6） 加工工序的劃分一般可按下列方法進行： ① 刀具集中分序法 就是按所用刀具劃分工序，用同一把刀具加工完零件上所有可以完成的部位。 車端面和鉆中心孔 —對數(shù)控車削而言，通常將他們作為預(yù)備加工工序安排。階梯軸的工藝規(guī)程及工裝設(shè)計 11 過量彎曲變形會造成加工余量不足及裝夾不可靠。 數(shù)控車削時，為了能用同一程序重復(fù)加工和工件調(diào)頭加工軸向尺寸的準(zhǔn)確性，或為了端面余量均勻，工件軸向需要定位。如圖典型軸類直徑相差不大，采用直徑為 90mm，材料 45鋼，在鋸床上按 290mm長度下料。軸頸的直徑公差等級通常為 IT6IT8，幾何形狀精度主要是圓度和圓柱度，一般要求限制在直徑公差范圍之內(nèi)。切削用量包括主軸轉(zhuǎn)速、背吃刀量及進給速度等。而有些工廠采用光學(xué)對刀鏡、對刀儀 、自動對刀裝置等，以減少對刀時間，提高對刀精度。所謂 “刀位點 ”是指刀具的定位基準(zhǔn)點，車刀的刀位點為刀尖或刀尖圓弧中心。對刀點設(shè)置原則是 :便 于數(shù)值處理和簡化程序編制。 選擇車刀圓弧半徑時應(yīng)考慮兩點車刀切削刃的圓弧半徑應(yīng)小于或等于零件凹形輪廓上的最小曲率半徑，以免發(fā)生加工干淺該半徑不宜選擇太小，否則不但制造困難，還會因刀尖強度太弱或刀體散熱能力差而導(dǎo)致車刀損壞。 二是圓弧形車刀。尖形車刀是以直線形切削刃為特征的車刀。 選擇數(shù)控車削用刀具 數(shù)控車削車刀常用的一般分成型車刀、尖形車刀、圓弧形車刀以及三類。車間內(nèi)某一工序的生產(chǎn)率限制了整個車間的生產(chǎn)率的提高時，該工序的刀具壽命要選得低些當(dāng)某工序單位時間內(nèi)所分擔(dān)到的全廠開支 M 較大時，刀具壽命也應(yīng)選得低些。 選擇刀具壽命時可考慮如下幾點根據(jù)刀具復(fù)雜程度、制造和磨刀成本來選擇。 確定合理的裝夾方式 裝夾方法：用三 爪自定心卡盤毛坯左端 Φ90，加工右端達到工件精度要求。這種方式比較安全，能承受較大的切削力，安裝剛性好，軸向定位準(zhǔn)確，應(yīng)用較廣泛。對于尺寸較大或加工工序較多的軸類工件，為了保證每次裝夾時的裝夾精度，可用兩頂尖裝夾。 階梯軸的工藝規(guī)程及工裝設(shè)計 6 數(shù)控車床常用的裝夾方式 1）在三爪自定心卡盤上裝夾。批量 加工時在工件坐標(biāo)系已經(jīng)確定的情況下，保證對刀的可能性和方便性。為了避免基準(zhǔn)不重合誤差，方便編程，應(yīng)選用工序基準(zhǔn)作為定位基準(zhǔn)，盡量使工序基準(zhǔn)、定位基準(zhǔn)、編程原點三者統(tǒng)一。 階梯軸的工藝規(guī)程及工裝設(shè)計 5 3 工件的裝夾 定位基準(zhǔn)的選擇 在制定零件加工的工藝規(guī)程時， 正確地選擇工件的定位基準(zhǔn)有著十分重要的意義。 軸頸的表面粗糙度值 Ra 應(yīng)與尺寸公差等級相適應(yīng)。 零件的技術(shù)要求 由于條件不同，軸類零件的技術(shù)要求也不完全相同。用寬度為 3mm 的切斷刀切槽及切斷，然后用 60176。由于獲得同一級精度及表面粗糙度的加工方法一般有許多，因而在實際選擇時，要結(jié)合零件的形狀、尺寸大小和形位公差要求等全面考慮。最終形成的工藝文件要完整，并能指導(dǎo)實際生產(chǎn)。以機械加工中車工工藝學(xué)與數(shù)控車床技能訓(xùn)練密切結(jié)合為主線，常用量具識讀及工件測量、刀具及安裝、工件定位與安裝、金屬切削過程及精加工，較清晰地展示了數(shù)控車工必須掌握的知識和技能的訓(xùn)練途徑。同時本文還應(yīng)用數(shù)控宇龍仿真軟件進行手動編