電大液壓與氣動技術(shù)期末考試答案小抄參考

1、成都市技師學(xué)院20092010學(xué)年度（上期）液壓與氣動技術(shù)期末考試_系_ _專業(yè)_班 姓名_學(xué)號_題號一二三四五總分一 填空題（每空 1 分，共 20 分）1、液壓與氣壓傳動是以 流體 為工作介質(zhì)進(jìn)行能量的 傳遞 和 控制 的一種傳動形式。2、液壓油的粘度隨液壓油的溫度和壓力而變，當(dāng)壓力增大時，液壓油粘度 增大 ；當(dāng)液壓油溫度升高時，液壓油的粘度 降低 。3、液壓與氣壓傳動系統(tǒng)由 能源裝置 、 執(zhí)行裝置 、 控制裝置 和輔助元件四個部分組成。4、液壓缸的作用是將 壓力能 轉(zhuǎn)變?yōu)橹本€運(yùn)動或擺動的 機(jī)械能 是液壓傳動系統(tǒng)中的執(zhí)行元件。5、液壓泵是一種 能源 裝置，它將機(jī)械能轉(zhuǎn)換為 壓力能 是液壓傳

2、動系統(tǒng)中的動力元件。6、溢流閥通常并接在液壓泵的出口，用來保證液壓系統(tǒng)的出口壓力恒定時稱為 定壓閥 ；用來限制系統(tǒng)壓力的最大值稱為 安全閥 ；還可以在執(zhí)行元件不工作時使液壓泵 卸載 。7、在結(jié)構(gòu)上，所有液壓閥都是由 閥芯 、 閥體 和 驅(qū)動閥芯動作的元器件 組成。8、液壓閥按照用途可分為 方向控制閥 、 壓力控制閥 和 流量控制閥 三大類。二 判斷題（每題2分，共20分）1、在液壓系統(tǒng)中液壓缸和馬達(dá)都可以作為執(zhí)行裝置。 （ ）2、一般液壓油的密度為900kg/m3。 （ ）3、液壓系統(tǒng)的流量等于橫截面積與流體平均速度的乘積，與工作壓力無關(guān)。（ ）4、液壓馬達(dá)是液壓系統(tǒng)中的能源裝置。 （ ）5、

3、液壓系統(tǒng)執(zhí)行元件運(yùn)動速度較高時，宜選粘度大的液壓油。 （ ）6、減壓閥的閥口常閉，溢流閥的閥口常開。 （ ）7、各類液壓閥在工作原理上都是通過改變閥芯與閥體的相對位置來控制和調(diào)節(jié) 液流的壓力、流量及流動方向。 （ ）8、當(dāng)液控單向閥的控制口k處無壓力油通入時，它的工作和普通單向閥一樣。 （ ） 9、流量控制閥是通過改變閥口的大小，改變液阻，實(shí)現(xiàn)流量調(diào)節(jié)的閥。（ ）10、節(jié)流閥的剛性差，只適用于執(zhí)行元件工作負(fù)載不大且對速度穩(wěn)定性要求不高的場合。 （）三、單項選擇題（每題2分，共20分）1、 選擇液壓用油首先要考慮的是（ c ）問題。a液壓系統(tǒng)的工作壓力 b運(yùn)動速度 c 粘度問題 d環(huán)境溫度2、廣

4、泛應(yīng)用于龍門刨床、拉床、液壓機(jī)、工程機(jī)械、礦山冶金機(jī)械、船舶上液 壓泵是（ c ）。a齒輪泵 b葉片泵c柱塞泵 d螺桿泵3、常用于送料和轉(zhuǎn)位裝置、液壓機(jī)械手以及間歇進(jìn)給機(jī)構(gòu)等輔助運(yùn)動的是（ b）a活塞式液壓缸 b擺動式液壓缸c柱塞式液壓缸 d伸縮液壓缸4、當(dāng)單桿活塞缸的（c）時，活塞的運(yùn)動速度最快。a壓力油進(jìn)入無桿腔 b壓力油進(jìn)入有桿腔c左右兩腔同時通入壓力油（差動連接）5、下列液壓泵不能調(diào)節(jié)流量的是（ c ）。a軸向柱塞泵 b徑向柱塞泵c 齒輪泵 d 單作用葉片泵6、以下控制閥圖形符號那一個是直動式溢流閥( a )7、能夠使油口p和t通，油口a、b封閉，液壓泵卸載，液壓缸兩腔閉鎖的滑閥中位機(jī)

5、能是（ d ）。a、o型 b、h型 c、y型 d、m型 8、（ b）在常態(tài)時，閥口是常開的，進(jìn)、出油口相通。a 溢流閥； b減壓閥； c順序閥9、應(yīng)用最廣的減壓閥類型是（ a ）。a 定值減壓閥； b定差減壓閥； c定比減壓閥10、與溢流閥的圖形符號和動作原理相同的是（b）。a、內(nèi)控外泄順序閥 b、內(nèi)控內(nèi)泄順序閥 c、外控外泄順序閥 d、外控內(nèi)泄順序閥四、問答題（每題10分，共20分）、液壓系統(tǒng)由哪四部分組成？各部分的作用是什么？答：能源裝置：把機(jī)械能轉(zhuǎn)換為流體壓力能的裝置執(zhí)行裝置：把流體的壓力能裝換位機(jī)械能輸出控制裝置：對系統(tǒng)中流體的壓力、流量和流動方向進(jìn)行控制或調(diào)解的裝置，以進(jìn)行信號轉(zhuǎn)換、

6、邏輯運(yùn)算和放大等功能的信號控制元件輔助元件：保證系統(tǒng)的正常工作所需的其它裝置2、液壓泵完成吸油和壓油的基本條件是什么？液壓泵在液壓系統(tǒng)中的工作壓力取決于什么？ 答： 必須具備可變化的密封容積、吸油腔和壓油腔隔開、有與密封容積變化相協(xié)調(diào)的配油裝置及吸油腔與油箱大氣相通這四個條件。 工作壓力取決于外負(fù)載五、計算題（本題分、b兩題，任選一題來做，題18分，b題20分）題：畫出下列元件的職能符號雙向變量液壓泵單桿活塞缸普通單向閥三位四通電磁換向閥溢流閥直動式減壓閥內(nèi)控外泄順序閥可調(diào)節(jié)流閥b題：已知如圖所示的單活塞桿液壓缸，活塞內(nèi)徑d100mm，活塞桿直徑為d50mm，工作壓力p12mpa，流量q110

7、l/min，回油被壓力p20.5mpa。試求：活塞往返運(yùn)動時的推力和運(yùn)動速度？winger tuivasa-sheck, who scored two tries in the kiwis 20-18 semi-final win over england, has been passed fit after a lower-leg injury, while slater has been named at full-back but is still recovering from a knee injury aggravated against usa.both sides boast

8、100% records heading into the encounter but australia have not conceded a try since josh charnleys effort in their first pool match against england on the opening day.aussie winger jarryd hayne is the competitions top try scorer with nine, closely followed by tuivasa-sheck with eight.but it is recen

9、tly named rugby league international federation player of the year sonny bill williams who has attracted the most interest in the tournament so far.the kiwi - with a tournament high 17 offloads - has the chance of becoming the first player to win the world cup in both rugby league and rugby union af

10、ter triumphing with the all blacks in 2011.id give every award back in a heartbeat just to get across the line this weekend, said williams.the (lack of) air up there watch mcayman islands-based webb, the head of fifas anti-racism taskforce, is in london for the football associations 150th anniversar

11、y celebrations and will attend citys premier league match at chelsea on sunday.i am going to be at the match tomorrow and i have asked to meet yaya toure, he told bbc sport.for me its about how he felt and i would like to speak to him first to find out what his experience was.uefa hasopened discipli

12、nary proceedings against cskafor the racist behaviour of their fans duringcitys 2-1 win.michel platini, president of european footballs governing body, has also ordered an immediate investigation into the referees actions.cska said they were surprised and disappointed by toures complaint. in a state

13、ment the russian side added: we found no racist insults from fans of cska. baumgartner the disappointing news: mission aborted.the supersonic descent could happen as early as sunda.the weather plays an important role in this mission. starting at the ground, conditions have to be very calm - winds le

14、ss 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 day-to-day weather lives. it will climb higher than the tip of mount everest (5.5 miles/8.85 kilometers), drif

15、ting even higher than the cruising altitude of commercial airliners (5.6 miles/9.17 kilometers) and into the stratosphere. as he crosses the boundary layer (called the tropopause),e can expect a lot of turbulence.the balloon will slowly drift to the edge of space at 120,000 feet ( then, i would assu

16、me, he will slowly step out onto something resembling an olympic diving platform.they blew it in 2008 when they got caught cold in the final and they will not make the same mistake against the kiwis in manchester.five years ago they cruised through to the final and so far history has repeated itself

17、 here - the last try they conceded was scored by englands josh charnley in the opening game of the tournament.that could be classed as a weakness, a team under-cooked - but i have been impressed by the kangaroos focus in their games since then.they have been concentrating on the sort of stuff that w

18、ins you tough, even contests - strong defence, especially on their own goal-line, completing sets and a good kick-chase. theyve been great at all the unglamorous stuff that often goes unnoticed in the stands but not by your team-mates.it is as though their entire tournament has been preparation for the final.in johnathan thurston, cooper cronk, cameron smith and either billy slater or greg inglis at full-back they have a spine that is unmatched in rugby league. they have played in so many high-pressure games - a pricel