2023年全國碩士研究生考試考研英語一試題真題(含答案詳解+作文范文)_第1頁
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1、<p>  Mechanical Presses functional design and calculation</p><p>  ————————————————————————————————————————-</p><p>  Abstarct: Large mechanical press briefing functional design of the wo

2、rk load, the main electrical power transmission and inertia flywheel is fixed, and the application of technology based Komatsu, summed up the simple formula to complete the more complex operations, saves time and effort,

3、 practical and reliable. </p><p>  Key words Mechanical Presses, work load ,main motor, power Flywheel </p><p>  ———————————————————————————————————</p><p>  Closed single large, d

4、ouble-action mechanical press for the successful design of the volume is not one of the important parameters, This is the work for several of the total, while the main motor, flywheel between certain, Operators are compl

5、ex. Based on the study Komatsu technology on the basis of press design of work load, Main electrical power and Flywheel determined using a simple formula to complete the more complicated arithmetic. The formula called fo

6、r public 2000kN edge over the slider t</p><p>  Note : * The complicated formula for the calculation results, other basic calculation of the same or similar. </p><p>  Design of the press, in ge

7、neral, are based on the user's requirements for design. For the function and parameters, some done directly by the user, then according to the value. </p><p>  1 Gong press for the calculation</p>

8、<p>  E=Ph+PBhB+PDS/KD   (1)</p><p>  Where : E——Press required the biggest work load, J </p><p>  P—— said the public power (even within the slider to move the public said Li), N; </p

9、><p>  h——pressure on the trip (double-action of the pressure inside slider trip), m (h=0.013~0.015m general admission, or the requirements by the user);</p><p>  PB—— slider outside of the public

10、said, N; </p><p>  hB—— slider outside pressure journeys m (hB=0.006m general admission, or the requirements by the user); Were cushion, N; </p><p>  PD—— cushion capacity coefficient (general

11、admission KD=6); </p><p>  S——slider trip (double-action program for the inside slider), m </p><p>  Single-action design press time, according to PB=0, hB=0 calculation; without air-cushioned b

12、y the Press PD=P/6 calculation; Blanking, trimming, forging presses can be used by PD=0 calculation. </p><p>  I plant design and production of 8000kN Closed 4:00 single-action multi-link mechanical press as

13、 an example. Li said P=8000kN public pressure h=13mm trip, the itinerary S=800mm slider, PD=2000kN cushion edge, trips 10~18min-1. </p><p>  In E=8000×103×0.013+2000×103×0.8/6=3.7×10

14、5?。↗)</p><p>  2 PH main electrical power to determine the</p><p>  AC motor : </p><p>  DC Motor: </p><p>  8000kN press using the DC motor speed control, it may :&l

15、t;/p><p>  Motor check samples, the main election to 158kW motor power </p><p>  3 Flywheel GD2 Determination </p><p>  K=2Sk-S2k   (5)</p><p>  Where : GD2—— Flywheel, k

16、gm2 (including clutch follower. General admission GD2 15%);</p><p>  N——Flywheel revolutions, r/min </p><p>  K——Flywheel energy release rate,%;</p><p>  Sk——Changes in the rate of

17、speed (motor slippery slip) ,%。 </p><p>  Single Action Press ,intake Sk=10.5%~15%,K=0.199~0.278</p><p>  Double-action Press, intake Sk=15.5%~20%,K=0.286~0.36</p><p>  Sk more t

18、han 20%, press cycle time, the DC motor speed control or wound motor, from Sk=20.5%~30.5%,K=0.368~0.517</p><p>  Variable-speed motor-driven wheels, if the low-speed, high-speed all for the same work load, r

19、equired increase the speed slow rate of change, while reducing per-minute work trips. </p><p>  8000kN press using the DC motor speed control, slip slip, meet the very moment when the work load of Flywheel c

20、alculated as follows : </p><p>  Low speed trips 10min-1, N=155r/min flywheel revolutions, Sk=28.8% election, K=0.492 </p><p>  By type (4) draw :</p><p>  GD2 value including clutc

21、h follower.</p><p>  According to user requirements, the press on the link in the first and cushion high, resulting in the numerical calculation is greater. Komatsu press with the Jinan Plant No. 2 and the p

22、roduction of similar products as compared with the corresponding parameters of the same or similar. </p><p><b>  中文1182字</b></p><p>  機(jī)械壓力機(jī)功能設(shè)計(jì)及計(jì)算</p><p>  摘要 介紹大型機(jī)械壓力機(jī)功

23、能設(shè)計(jì)中的作功量、主電機(jī)功率和飛輪傳動慣量的確 定,并在研究應(yīng)用小松技術(shù)的基礎(chǔ)上,總結(jié)出簡便的公式來完成這一較為復(fù)雜的運(yùn)算,省時(shí)省力,可靠實(shí)用。關(guān)鍵詞 機(jī)械壓力機(jī) 作功量 主電機(jī)功率 飛輪轉(zhuǎn)動慣量 大型閉式單、雙動機(jī)械壓力機(jī)的作功量是設(shè)計(jì)中一項(xiàng)不可忽視的重要參數(shù),這個(gè)參數(shù)是幾個(gè)方面作功量的總和,同時(shí)又與主電機(jī)、飛輪之間存在一定的關(guān)系,運(yùn)算很復(fù)雜。本文在研究小松技術(shù)的基礎(chǔ)上,將壓力機(jī)設(shè)計(jì)中的作功量、主電機(jī)功率和飛輪轉(zhuǎn)動慣量的

24、確定,采用一種簡便的公式來完成這一較為復(fù)雜的運(yùn)算。本公式對于公稱力2000kN以上、滑塊行程400~1000mm的閉式四點(diǎn)單動、雙動或多連桿機(jī)械壓力機(jī)均可應(yīng)用。通過對不同類型的小松壓力機(jī)有關(guān)參數(shù)如公稱力、滑塊行程、壓力行程、氣墊力和主電機(jī)功率等參數(shù)的分析計(jì)算,與繁瑣公式計(jì)算比較基本相同或相近,所以本公式省時(shí)省力,可靠實(shí)用。舉例如下表(均是引進(jìn)小松產(chǎn)品)。 </p><p>  注:*為繁瑣公式計(jì)算結(jié)果,其他項(xiàng)計(jì)算

25、基本相同或相近。 在壓力機(jī)設(shè)計(jì)中,一般都是根據(jù)用戶的要求進(jìn)行設(shè)計(jì)。對于作功量參數(shù),有的用戶直接做了規(guī)定,那么就按規(guī)定的值計(jì)算。1 壓力機(jī)作功量的計(jì)算</p><p>  E=Ph+PBhB+PDS/KD   (1) 式中:E——壓力機(jī)需產(chǎn)生的最大作功量,J;    P——公稱力(雙動為內(nèi)滑塊公稱力),N;    h——壓力行程(雙動為內(nèi)滑塊壓力行程),m(一般取h=0.01

26、3~0.015,或由用戶所需規(guī) 定);   </p><p>  PB——外滑塊的公稱力,N;    hB——外滑塊的壓力行程,m(一般取hB=0.006m,或由用戶所需規(guī)定);    PD——?dú)鈮|力,N;    KD——?dú)鈮|能力系數(shù)(一般取KD=6);    S——滑塊行程(雙動為內(nèi)滑塊行程),m。 設(shè)計(jì)單動壓力機(jī)時(shí),按PB=0、hB=0計(jì)算;不帶氣墊的壓

27、力機(jī)按PD=P/6計(jì)算;落料、修邊、鍛造用壓力機(jī)可以按PD=0計(jì)算。 以我廠設(shè)計(jì)生產(chǎn)的8000kN閉式四點(diǎn)單動多連桿機(jī)械壓力機(jī)為例,公稱力P=8000kN,壓力行程h=13mm,滑塊行程S=800mm,氣墊力PD=2000kN,行程次數(shù)10~18min-1。 得 E=8000×103×0.013+2000×103×0.8/6=3.7×105?。↗)2 主電機(jī)功率P

28、H的確定 (1)交流電動機(jī): </p><p><b> ?。╓)</b></p><p>  (2)直流電動機(jī): </p><p><b> ?。╓)</b></p><p>  8000kN壓力機(jī)采用的是直流調(diào)速電機(jī),故得: </p><p><b> 

29、?。╓)</b></p><p>  查電機(jī)樣本,選主電機(jī)功率為158kW。3 飛輪轉(zhuǎn)動慣量GD2的確定 </p><p><b>  kgm</b></p><p>  K=2Sk-S2k   (5) 式中:GD2——飛輪轉(zhuǎn)動慣量,kgm2(包括離合器從動件,一般取GD2的15%左右);

30、 N——飛輪轉(zhuǎn)數(shù),r/min; K——飛輪的能量釋放率,%; Sk——速度變化率(電動機(jī)滑差率),%。 單動壓力機(jī),取Sk=10.5%~15%,K=0.199~0.278 雙動壓力機(jī),取Sk=15.5%~20%,K=0.286~0.36 Sk超過20%時(shí),壓力機(jī)周期時(shí)間延長,采用直流調(diào)速電動機(jī)或繞線式電動機(jī),取Sk=20.5%~30.5%,K=0.368~0

31、.517 用變速電機(jī)驅(qū)動飛輪時(shí),如果要求低速、高速都作相同的作功量,則需加大低速時(shí)的速度變化率,同時(shí)減少每分鐘工作行程次數(shù)。 8000kN壓力機(jī)采用的是直流調(diào)速電機(jī),滑差率高,滿足低速時(shí)作功量的飛輪轉(zhuǎn)動慣量計(jì)算如下: 低速時(shí)行程次數(shù)10min-1時(shí),飛輪轉(zhuǎn)數(shù)N=155r/min,選Sk=28.8%,K=0.492由式(4)得出: </p><p><b>  kgm)&

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