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.... 12 .............................................................................................................................. 13 第五部分 工藝裝備、切削用量和工時(shí) ....................................................................................... 13 第六部分 填寫機(jī)械加工工序卡 ................................................................................................... 17 表格參考 P255 頁(yè)表 612 .............................................................................................. 17 第七部分 專用卡規(guī)的設(shè)計(jì) 零件年產(chǎn)量為中批量, 而且零件加工的輪廓尺寸不大,在考慮提高生產(chǎn)率保證加工精度后可采用鑄造成型中的金屬模鑄造。 粗基準(zhǔn)的選擇 重點(diǎn)考慮到既要保證在各加工面均有加工余量的前提下,使重要孔或面的加工余量盡量均勻,又要保證定位夾緊的可靠性,裝夾的方便性,減少輔助時(shí)間,所以選杠桿零件Φ 28H7 孔及Φ 10H7 孔外端面為粗基準(zhǔn)。 Φ 28H7孔加工,它將作為精基準(zhǔn)以完成以后的加工,為達(dá)到題目要求我們采取粗?jǐn)U — 精擴(kuò) — 鉸的工序過(guò)程,最終完成Φ 28H7孔加工。 各表面加 工方案如下表 加工表面 尺寸精度等級(jí) 表面粗超度 Ra/μ m 加工方案 備注 Φ 28HΦ10H7孔外端面 IT7 粗銑 — 半精銑 Φ 10H7孔上端面 IT7 粗銑 Φ 28H7孔加工 IT7 粗?jǐn)U — 精擴(kuò) —鉸 Φ 10H7孔加工 IT7 鉆 — 精鉸 3. 加工順序的安排 加工階段的劃分 該杠桿加工質(zhì)量要求一般,可將加工階段劃分成粗加工和精加工28 兩個(gè)階段。 28 在粗加工之后,為消除切削加工過(guò)程中工件的內(nèi)應(yīng)力而安排的熱處理工序:人工時(shí)效處理 (3)輔助工序安排 在粗加工和熱處理后,安排去毛刺;在精加工后,安排去毛刺、清洗和終檢工序。 第四部分 余量和工序尺寸的確定 1. 孔和軸的余量和工序尺寸(工序基準(zhǔn)不變的工序尺寸計(jì)算) 確定加工余量: 由表 21 和 25 查得對(duì)于中批生產(chǎn),采用金屬型鑄造成型,取其尺寸公差等級(jí)為 7 級(jí),加工余量等級(jí)為 F 級(jí) . 235( 平面粗加工 余量),查得:上端面的加工余量為 3mm 315(直柄立銑刀),查得:銑刀的直徑為 . 2. 平面及軸向尺寸的余量和工序尺寸(工序基準(zhǔn)變化的工序尺寸計(jì)算) 杠桿尺寸公差 零件毛坯尺寸 公差 Φ 10H7 兩孔外端面 Φ 28H7 孔外端面 28 工序 ( 1)、背吃刀量的確定 :一次走刀, ap==3 ( 2)、進(jìn)給量確定:由表 57,按機(jī)床功率 5— 10kw,工件夾具系統(tǒng)剛度為中等條件選取,該工序的每齒進(jìn)給量 fz 取為 ( 3)、銑削速度的計(jì)算:由表 59,按鑲齒銑刀, d/z=80/10 的條件選取,銑削速度 v 可取為 40m/min。根據(jù)《設(shè)計(jì)指南》表 5148P199 和表5149P200可知,用硬質(zhì)合金端銑刀粗加工,銑刀刀齒后刀面最大磨損量為 1mm;銑刀直徑為 100mm,耐用度為 T=180min。t appealed against the disciplinary action your employer has taken against you. However, if you win your case, the tribunal may reduce any pensation awarded to you as a result of your failure to appeal. Remember that in most cases you must make an application to an employment tribunal within three months of the date when the event you are plaining about happened. If your application is received after this time limit, the tribunal will not usually accept i. If you are worried about how the time limits apply to you If you are being represented by a solicitor at the tribunal, they may ask you to sign an agreement where you pay their fee out of your pensation if you win the case. This is known as a damagesbased agreement. In England and Wales, your solicitor can39。s 150th anniversary celebrations and will attend City39。s governing body, has also ordered an immediate investigation into the referee39?;蛟S是愧疚于自己似乎把轉(zhuǎn)瞬即逝的很多個(gè)不 同的日子過(guò)成了同一天的樣子;或許是追溯過(guò)去,對(duì)自己那些近乎偏執(zhí)的怪異信念的醒悟,這些天以來(lái),思緒一直很凌亂,在腦海中不斷糾纏。 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。t remember his appearance. 童年時(shí),覺(jué)得壓歲錢和新衣服是過(guò)年必備,但是隨著年齡的推進(jìn),會(huì)越來(lái)越發(fā)現(xiàn),那些東西根本就可有可無(wú);初中時(shí),以為要有 一場(chǎng)暗戀才意味著真正的成長(zhǎng),但三年過(guò)去后,自己心平氣和的寫同學(xué)錄的時(shí)候,突然就發(fā)現(xiàn)是不是真正的成長(zhǎng)了,好像并沒(méi)有那么重要了;然后到了高中,覺(jué)得非要吐露出自己的心聲才能為高中生涯里的懵懂情愫劃上一個(gè)句點(diǎn),但畢業(yè)晚會(huì)的時(shí)候最終還是被梗塞在了咽喉,后來(lái)再次站在他曾經(jīng)揮汗如雨的球場(chǎng),看著他投過(guò)籃球的球框時(shí),突然間發(fā)現(xiàn)自己已經(jīng)想不起他的容顏。想要的,不想要的,界限明確,好像沒(méi)有什么可以撼動(dòng)自己。 At the moment, the sky is dark, the air is fresh factor after just rained. Suddenly thought of blue plaid shirt。t start planning... Those years, those days of do, finally, like youth, will end in our life. 此刻,天空是陰暗的,空氣里有著剛下過(guò)雨之后的清新因子。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。如果我們一味逃避生活中的悲傷,悲傷只會(huì)變得更強(qiáng)烈更真實(shí) —— 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 。 The initial impulse is to run away — to try and suppress these feelings by not acknowledging them. When we do this, we close ourselves off to the parts of our lives that we need to experience most. The next time you have this feeling of being truly unfortable, do yourself a favor and lean into the feeling. Act in spite of the fear. 28 我們的第一反應(yīng)總是逃避 —— 以為否認(rèn)不安情緒的存在就能萬(wàn)事大吉,可這也恰好妨礙了我們經(jīng)歷最需要的生活體驗(yàn)。 From: The supersonic descent could happen as early as Sunda. The weatheThe balloon will slowly drift to the edge of space at 120,000 feet (Then, I would assume, he will slowly step out onto something resembling an Olympic diving platform. Below, the Earth bees the concrete bottom of a swimming pool that he wants to land on, but not too hard. Still,