【正文】 boring jig. Keywords: Piston。C (approximately 820176。接著確定加工余量、工序尺寸，經(jīng)過對工序特點(diǎn)的分析，恰當(dāng)選擇相應(yīng)加工設(shè)備和工藝裝備。奧托循環(huán)式發(fā)動機(jī)，是根據(jù)其發(fā)明者，德國機(jī)械師尼古拉斯 .奧格事特 .奧托的名字來命名的。活塞與曲軸之間通過連桿相互連接。在奧托式發(fā)動機(jī)上，并不是靠化油器來進(jìn)行燃油霧化的，而是利用燃油的直接噴入，一直到現(xiàn)在都是如此。 所有的發(fā)動機(jī)上，火花塞的位置都必須適宜。這些采用風(fēng)冷的發(fā)動機(jī)都必須有很多散熱片，一邊有較大的散熱面積，從 而很好的帶走汽缸的熱量。一邊帶動增壓器工作，來增加發(fā)動機(jī)的功率。發(fā)動機(jī)的效率會受到很多因素的限制，例如冷卻損失以及摩擦損失。其次，在壓縮時，活塞將空氣壓縮到比先前小很多倍的體積，并在這個過程中使空氣的溫度達(dá)到 440℃ （等同于華氏820℉ ） 。但是也有一些柴油機(jī)的轉(zhuǎn)速達(dá)到了 2020 轉(zhuǎn)每分鐘。這是活塞在燃?xì)鈮毫Φ淖饔孟孪滦?，廢棄就會從排氣口由汽缸內(nèi)向外排出去。另外，它簡單的結(jié)構(gòu)使得生產(chǎn)成本低，冷卻系統(tǒng)質(zhì)量輕，另外它的重心低，使得他的安全性得到了增加。這樣最高火焰溫度就會比較合適，從而很好的限制 NOx 化合物的生成量以及 CO 和 HC 的排放量。日本的汽車制造商 — 馬自達(dá)，繼續(xù)了改善轉(zhuǎn)子發(fā)動機(jī)燃油經(jīng)濟(jì)性的設(shè)計和研發(fā)?；旌蠚怏w通過轉(zhuǎn)子的旋轉(zhuǎn)得到壓縮，最后被火花塞點(diǎn)燃。二沖程的有點(diǎn)在于，縮短了燃料壓縮的時間，并且減少了燃料的浪費(fèi)以及用半個沖程完成了四沖程 發(fā)動機(jī)的一個壓縮沖程。第四個沖程跟奧托式四沖程發(fā)動機(jī)一樣，都是排氣過程?，F(xiàn)在，好的發(fā)動機(jī)的效率在 20％ 25％，也就是說，只有這部分能量真正用于產(chǎn)生機(jī)械能量。活塞在這個過程中的運(yùn)動，使得燃料和空氣進(jìn)入燃燒室混合。與蒸汽機(jī)和渦輪機(jī)不同，內(nèi)燃機(jī)在發(fā)動時并不會產(chǎn)生轉(zhuǎn)矩，并且扭矩的輸出必須要靠曲軸的轉(zhuǎn)動才行。這個高壓電流會被分電器分配到各個汽缸，件叫做火花，一個安裝在汽缸頂部被叫做火花塞的零件。進(jìn)排氣門的開本科 生畢業(yè) 設(shè)計（論文）外文翻譯 7 閉都是通過凸輪軸的轉(zhuǎn)動從而牽動氣門彈簧作用到挺桿，在正確的時間是氣門開閉。曲軸上接有飛輪并有平衡坑。奧托式發(fā)動機(jī)和柴油機(jī)的工作方式都是二沖程或者四沖程。在本畢業(yè)設(shè)計中特別設(shè)計了定位準(zhǔn) 確、結(jié)構(gòu)簡單和使用方便的精鏜銷孔夾具?？梢?，活塞是在高溫高壓下作長時間連續(xù)變負(fù)荷的往復(fù)運(yùn)動，它的負(fù)荷和工作環(huán)境很惡劣。 Fixture Any type of machine that obtains mechanicalenergy directly from the expenditure of the chemical energy of fuel burned in a bustion chamber that is an integral part of the engine. Four principal types of internalbustion engines are in general use: the Ottocycle engine, the diesel engine, the rotary engine, and the gas turbine. For the various types of engines employing the principle of jet propulsion, see Jet Propulsion。 Technology。F) by this pression. At the end of the pression stroke, vaporized fuel is injected into the bustion chamber and burns instantly because of the high temperature of the air in the chamber. Some diesels have auxiliary electrical ignition systems to ignite the fuel when the engine starts and until it warms up. This bustion drives the piston back on the third, or power, stroke of the cycle. The fourth stroke, as in the Ottocycle engine, is an exhaust stroke. The efficiency of the diesel engine, which is in general governed by the same factors that control the efficiency of Ottocycle engines, is inherently greater than that of any Ottocycle engine and in actual engines today is slightly more than 40 percent. Diesels are, in general, slowspeed engines with crankshaft speeds of 100 to 750 revolutions per minute (rpm) as pared to 2500 to 5000 rpm for typical Ottocycle engines. Some types of diesel, however, have speeds up to 2020 rpm. Because diesels use pression ratios of 14 or more to 1, they are generally more heavily built than Ottocycle engines, but this disadvantage is counterbalanced by their greater efficiency and the fact that they can be operated on less expensive fuel oils. By suitable design it is possible to operate an Ottocycle or diesel as a twostroke or twocycle engine with a power stroke every other stroke of the piston instead of once every four strokes. The power of a twostroke engine is usually double that of a fourstroke engine of parable size. The general principle of the twostroke engine is to shorten the periods in which fuel is introduced to the bustion chamber and in which the spent gases are exhausted to a small fraction of the duration of a stroke instead of allowing each of these operations to occupy a full stroke. In the simplest type of twostroke engine, the poppet valves are replaced by sleeve 本科 生畢業(yè) 設(shè)計（論文）外文翻譯 5 valves or ports (openings in the cylinderwall that are uncovered by the piston at the end of its outward travel). In the twostroke cycle, the fuel mixture or air is introduced through the intake port when the piston is fully withdrawn from the cylinder. The pression stroke follows, and the charge is ignited when the piston reaches the e