【正文】 的。其基本原則是： ① 力求空行程路線最短。 ② 力求切削進(jìn)給路線最短。 矩形進(jìn)給路線，適用于棒料毛坯，進(jìn)給路線較短。 河 南 工 業(yè) 職 業(yè) 技 術(shù) 學(xué) 院 畢 業(yè) 設(shè) 計 16 仿形進(jìn)給路線，用于鑄、鍛件毛坯時進(jìn)給路線較短。 2）數(shù)控銑削進(jìn)給路線的確定 數(shù)控銑削加工中進(jìn)給路線對零件的加工精度和表面質(zhì)量有直接的影響，因此，確定好進(jìn)給路線是保證銑削加工精度和表面質(zhì)量的工藝措施之一。 在圖中，左圖和中圖分別為用行切法加工和環(huán)切法加工凹槽的走刀路線，而右圖是先用行切法，最后環(huán)切一刀光整輪廓表面。 根據(jù)以上分析，本課題所加工的軸上的鍵槽采用右圖所示的走刀方案。 當(dāng)主要表面加工順序確定后，就要合理地插入非主要表面加工工序。這些表面加工一般不易出現(xiàn)廢品，所以盡量安排在后面工序進(jìn)行，主要表面加工一旦出了廢品，非主要表面就不需加工了，這樣 河 南 工 業(yè) 職 業(yè) 技 術(shù) 學(xué) 院 畢 業(yè) 設(shè) 計 17 可以避 免浪費工時。 加工余量的確定 加工余量的大小等于每個中間工序加工余量的總和。 1）應(yīng)有足夠的加工余量，特別是最后的工序，加工余量應(yīng)能保證達(dá)到圖樣上所規(guī)定的精度和表面粗糙度值要求。過大的加工余量反而會由于切削抗力的增加而引起工件變形加大，影響加工精度。 4）應(yīng)考慮工件的大小。 5）在保證加工精度的前提下，應(yīng)盡量采用最小的加工余量總和，以求縮短加工時間，降低加工費用。數(shù)控程序中的地址代碼意義如表 11所示。 ：整個編程過程由人工完成。 ：編程人員只要根據(jù)零件圖紙的要求，按照某個自動編程系統(tǒng)的規(guī)定， 將零件的加工信息用較簡便的方式送入計算機，由計算機自動進(jìn)行程序的編制，編程系統(tǒng)能自動打印出程序單和制備控制介質(zhì)。 根據(jù)以上各種程序編制的特點，對軸的加工程序的編制進(jìn)行以下選擇：由于 支承桿 的幾何形狀不太復(fù)雜，因此對其外圓表面的加工，應(yīng)選擇手工編程；其軸上的鍵槽雖不復(fù)雜但計算工作量大，因此選擇自動編程。 機床的發(fā)展趨向是高速化、高精度化、高可靠性、多功能、復(fù)合化、智能化和 開放式結(jié)構(gòu)。數(shù)控技術(shù)是機械加工自動化的基礎(chǔ)，是數(shù)控機床的核心技術(shù)，其水平高低關(guān)系到國家戰(zhàn)略地位和體現(xiàn)國家綜合實力的水平 . 它隨著信息技術(shù)、微電子技術(shù)、自動化技術(shù)和檢測技術(shù)的發(fā)展而發(fā)展。在加工中心上加工零件的特點是：被加工 零件經(jīng)過一次裝夾后，數(shù)控系統(tǒng)能控制機床按不同的工序自動選擇和更換刀具；自動改變機床主軸轉(zhuǎn)速、進(jìn)給量和刀具相對工件的運動軌跡及其它輔助功能，連續(xù)地對工件各加工面自動地進(jìn)行鉆孔、锪孔、鉸孔、鏜孔、攻螺紋、銑削等多工序加工。 將來展望 我國制造企業(yè)已開始廣泛使用先進(jìn)的數(shù)控技術(shù)，但掌握數(shù)控技術(shù)的機電復(fù)合人才卻缺口巨大。 據(jù)了解，目前全國城鎮(zhèn)企業(yè)共有 億名職工，其中技術(shù)工人有 7000 萬人。由此產(chǎn)生的后果是：全國企業(yè)產(chǎn)品的平均合格率只有 7% ， 河 南 工 業(yè) 職 業(yè) 技 術(shù) 學(xué) 院 畢 業(yè) 設(shè) 計 23 不良產(chǎn)品的經(jīng)濟(jì)損失達(dá)到 2022 億元之巨。 業(yè)內(nèi)人士指出，隨著我國加入世界貿(mào)易組織，中國有望成為世界制造中心，而預(yù)期的高級技工短缺勢必會給產(chǎn)品質(zhì)量和新產(chǎn)品開發(fā)帶來巨大的影響。有的用人單位為了搶到合適的技校畢業(yè)生，早在學(xué)生上一年級時就開始預(yù)定。有眼光的家長和學(xué)生應(yīng)該及時調(diào)整 思路，在未來幾年，技術(shù)工人比大學(xué)生甚至比博士生還要“吃香”。導(dǎo)師的教誨是寶貴的精神財富，并將使我受益終生。對此，我表示深深的感謝！ 最后，我還要深深地感謝默默支持本人完成學(xué)業(yè)的父母 及親友，感謝他們?yōu)槲宜龀龅臒o私奉獻(xiàn)和巨大支持！ 由于本人知識水平有限，設(shè)計過程中難免存在錯誤之處，敬請老師批評指正 。t agree with the disciplinary action your employer has taken against you your employer dismisses you and you think that you have been dismissed unfairly. For more informu, take advice from one of the anisations listed under Fur ther help. Employment tribunals are less formal than some other courts, but it is still a legal process and you will need to give evidence under an oath or affirmation. Most people find making a claim to an employment tribunal challenging. If you are thinking about making a claim to an employment tribunal, you should get help straight away from one of the anisations listed under Further help. ation about dismissal and unfair dismissal, see Dismissal. You can make a claim to an employment tribunal, even if you haven39。t charge you more than 35% of your pensation if you win the case. You are clear about the terms of the agreement. It might be best to get advice from an experienced adviser, for example, at a Citizens Advice Bureau. To find your nearest CAB, including those that give advice by , click on nearest CAB. For more information about making a claim to an employment tribunal, see Employment tribunals. The (lack of) air up there Watch m Cay man Islandsbased Webb, the head of Fifa39。s 150th anniversary celebrations and will attend City39。s about how he felt and I would like to speak to him first to find out what his experience was. Uefa has opened disciplinary proceedings against CSKA for the racist behaviour of their fans during City39。s governing body, has also ordered an immediate investigation into the referee39。s plaint. In a statement the Russian side added: We found no racist insults from fans of CSKA. Age has reached the end of the beginning of a word. May be guilty in his seems to passing a lot of different life became the appearance of the same day。或許是 愧疚于自己似乎把轉(zhuǎn)瞬即 逝的很多個不同的日子過成了同一天的樣子；或許是追溯過去，對自己那些 近乎偏執(zhí)的怪異信念的醒悟，這些天以來，思緒一直很凌亂，在腦海中不斷糾纏。二十年的人生軌跡深深淺淺，突然就感覺到有些事情，非做不可了。 Junior high school, thought to have a crush on just means that the real growth, but over the past three years later, his writing of alumni in peace, suddenly found that isn39。 Then in high school, 河 南 工 業(yè) 職 業(yè) 技 術(shù) 學(xué) 院 畢 業(yè) 設(shè) 計 26 think don39。t remember his appearance. Baumgartner the disappointing news: Mission aborted. r plays an important role in this mission. Starting at the ground, conditions have to be very calm winds less than 2 mph, with no precipitation or humidity and limited cloud cover. The balloon, with capsule attached, will move through the lower level of the atmosphere (the troposphere) where our daytoday weather lives. It will climb higher than the tip of Mount Everest ( miles/ kilometers), drifting even higher than the cruising altitude of mercial airliners ( miles/ kilometers) and into the stratosphere. As he crosses the boundary layer (called the tropopause),e can expect a lot of turbulence. We often close ourselves off when traumatic events happen in our lives。我們假裝一切仿佛都不曾發(fā)生，以此試圖忘卻傷痛，可就算隱藏得再好，最終也還是騙不了自己。下面六個方法有助于你更完滿透徹地敞開心扉。如果我們一味逃避生活中的悲傷，悲傷只會變得更強烈更真實 —— 悲傷原本只是稍縱即逝的情緒，我們卻固執(zhí)地耿耿于懷 By utilizing our breath we soften our experiences. If we dam them up, our lives will stagnate, but when we keep them flowing, we allow more newness and greater experiences to 。 [13]