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
已閱讀1頁,還剩4頁未讀, 繼續(xù)免費閱讀

下載本文檔

版權(quán)說明:本文檔由用戶提供并上傳,收益歸屬內(nèi)容提供方,若內(nèi)容存在侵權(quán),請進(jìn)行舉報或認(rèn)領(lǐng)

文檔簡介

1、<p><b>  附 錄</b></p><p>  (英文文獻(xiàn)及中英文對照)</p><p>  The designing features of automobile body</p><p>  welding fixture</p><p>  Auto body clamp is require

2、d for the amorphous body stamping required to locate and clamp, to form the body components, combined parts, sub-assembly and assembly, While taking advantage of suitable welding method to form their own welding pieces o

3、f the whole. Welding fixture welding process is a secondary device, but in the process of mass production car body, the device is essential. It not only can improve welding productivity, but also to ensure the dimensiona

4、l accuracy of welding products and</p><p>  1. asonable decomposition of auto body parts welded together to determine the type of fixture required. Two or more of the stamping process by the assembly and wel

5、ding of components is obtained by welding together pieces of several related small welding welding large pieces of formed pieces, then welded together to form the following four parts: Around before welding parts, weldin

6、g parts around the back, floor and roof welding parts welding parts, welding together four pieces of the final weldin</p><p>  2. Determine the level of automation of assembly and welding fixtures. Annual ou

7、tput depends on the level of automation and assembly and welding fixtures welders bit configuration. Production cycle time mainly by clamping action, the assembly time, welding time and handling time and other components

8、. Among them, the jig fixture operating time depends on the degree of automation. To improve productivity, consider clamping fixture and release time to complete the action by the cylinder, and betwee</p><p>

9、;  3. For large welding jigs, fixtures must first determine the design basis, with the same car body design basis. Fixture n the location of all the components are determined directly from the design basis, the ultimate

10、guarantee to create a qualified welding tooling structure. According to a preliminary decision height operations fixture floor height, the height of the clamped position; Second, draw the assembly and welding parts diagr

11、am, it is included in the station in need of assembly and weldi</p><p>  4. Rational choice of fixture position. As the car body shape complexity, poor rigidity, deformation, fixture positioning has been int

12、roduced on a large number of ways to enhance the rigidity of welded parts, reduce the welding deformation. Positioning of welding fixtures generally include positioning and side positioning of two kinds of holes. Positio

13、ning hole punching process to give priority to consider the positioning hole, the size and location of these holes is relatively accurate and reli</p><p>  5. Properly designed clamping mechanism. When the s

14、tamping on the correct positioning of the fixture, in order to maintain the welding process in the assembly of the workpiece position and overcome the elastic deformation of the workpiece, usually requires a certain clam

15、ping body. With this device, you can make the workpiece and the bearing surface, workpiece and positioning the workpiece and the workpiece surface and tight fit between. For thickness below 1.2mm steel plate, each clampi

16、ng point </p><p>  6. Other design elements. As the stamping quality checks are sampling, prone to problems. If possible, add in some welding fixture on some auxiliary devices, check the stamping play the ro

17、le of critical dimensions. In addition, assembly and welding fixture structure should be easy to operate, saving, security and easy handling characteristics of the workpiece.</p><p>  汽車車身焊裝夾具的設(shè)計要點</p>

18、<p>  汽車車身夾具是用來把所需車身沖壓件按要求定形、定位并夾緊,組合成車身組件、合件、分總成及總成,同時利用合適的焊接方法使其形成各自焊合件整體。焊接夾具屬于焊接工藝過程的輔助裝置,但在汽車車身大批量生產(chǎn)過程中,該裝置是必不可少的。它不僅可以提高焊接生產(chǎn)率,而且也是保證焊接產(chǎn)品的尺寸精度及外觀要求的重要裝置。而裝焊夾具沒有統(tǒng)一規(guī)格和標(biāo)準(zhǔn)化,屬于非標(biāo)準(zhǔn)設(shè)計和制造的工藝裝備,要根據(jù)具體車型的結(jié)構(gòu)特點、生產(chǎn)條件和實際需求來

19、自行設(shè)計與制造。</p><p>  1、合理分解汽車車身焊合件,確定所需夾具的種類。兩種或兩種以上的沖壓件經(jīng)裝焊工序后得到的部件即為焊合件,幾種相關(guān)的小焊合件組成大的焊合件,再形成以下四種焊合件:前圍焊合件、后側(cè)圍焊合件、地板焊合件以及頂蓋焊合件,這四種焊合件最終組焊成了汽車駕駛室總成。因此,要根據(jù)上述駕駛室總成形成過程進(jìn)行各種焊合件正確合理地分割,并在此基礎(chǔ)上進(jìn)行相應(yīng)焊合件夾具的設(shè)計。這樣,不僅有利于保證產(chǎn)品

20、質(zhì)量,還可以提高焊接生產(chǎn)率。 </p><p>  2、確定裝焊夾具自動化程度的高低。年產(chǎn)量決定于裝焊夾具的自動化水平及焊接工位的配置。生產(chǎn)節(jié)拍主要由夾具動作時間、裝配時間、焊接時間以及搬運時間等組成。其中,夾具動作時間主要取決于夾具的自動化程度。為提高生產(chǎn)率,可以考慮夾具的夾緊和松開動作由汽缸一次性完成,且工位和工位之間采用自動化運輸。但這就提高了夾具的制造成本。因此,設(shè)計夾具要能合理地平衡焊接夾具

21、的自動化水平及制造成本之間的矛盾。</p><p>  3、對于大型焊裝夾具,首先必須確定夾具的設(shè)計基準(zhǔn),它與汽車車身的設(shè)計基準(zhǔn)一致。夾具上全部元件的位置都是直接根據(jù)設(shè)計基準(zhǔn)確定的,最終保證制造出合格的焊接工裝結(jié)構(gòu)。根據(jù)作業(yè)高度可初步?jīng)Q定夾具底板的高度,即夾具固定位置的高度;其次繪制出裝焊工件圖,它包括在此工位上需要裝焊的沖壓件外形以及要求的焊點位置,以此作為夾具設(shè)置的基礎(chǔ);下一步是夾具位置的合理布置,為此必須清

22、楚地把握沖壓件的空間形狀、組合關(guān)系、裝焊順序以及焊點布置,合理設(shè)計夾具的安放位置和大致結(jié)構(gòu);最后繪出總體方案設(shè)計草圖。</p><p>  4、合理地選擇夾具的定位。由于汽車車身形狀復(fù)雜、剛性差、易變形,夾具定位上大量采用過定位方式,以增強(qiáng)焊接件剛性,減少焊接變形。焊接夾具的定位一般包括孔定位和面定位兩種??锥ㄎ粫r要優(yōu)先考慮用沖壓工序的定位孔,這些孔的尺寸和位置相對準(zhǔn)確可靠;盡量用下道工序的裝配孔,因為這些孔的尺

23、寸有誤差會影響下道工序的裝配。因此,設(shè)計夾具用孔定位時不僅要了解沖壓工序,還要考慮下道裝配工序的關(guān)鍵尺寸。定位孔盡可能選用較大的孔,這樣定位銷可以有足夠的強(qiáng)度,否則定位銷容易折斷。要優(yōu)選沖壓件上形狀可靠、穩(wěn)定的面作為定位面,盡可能地采用平面做定位面,但車身沖壓件大多為空間曲面,這就要求夾具定位元件的工作表面必須與車身上相應(yīng)的定位表面形狀保持一致,這樣才能在裝焊過程中保證車身的形狀。用面定位的部件要保證一定精度,調(diào)整定位塊的位置屬于粗調(diào),

24、要精確調(diào)節(jié)較為復(fù)雜,為此可以在定位塊上增加細(xì)調(diào)功能,即在定位塊上增加很薄的墊片,而墊片的厚度就是可以調(diào)整的精度。另外,設(shè)置定位時還要考慮焊接位置和所用焊接設(shè)備,既不能影響最終焊合件的取出,也可以讓焊鉗或者焊槍到達(dá)焊接位置。對于確實有影響的定位銷等要考慮采用可以活動的定位銷。</p><p>  5、正確設(shè)計夾緊機(jī)構(gòu)。當(dāng)沖壓件在夾具上正確定位后,為保持焊接過程中各工件的裝配位置以及克服工件的彈性變形,通常需要一定的

25、夾緊機(jī)構(gòu)。利用該裝置,可以使工件和支承面、工件和定位面以及工件和工件之間緊密貼合。對于1.2mm厚度以下的鋼板,每個夾緊點的夾緊力一般在300~750N 范圍內(nèi);對于1.5~2.5mm之間的沖壓件,每個夾緊點的夾緊力在500~3000N 范圍內(nèi)。為減少裝卸工件的輔助時間,夾緊裝置應(yīng)采用高效快速裝置和多點聯(lián)動機(jī)構(gòu)。對于薄板沖壓件,夾緊力作用點應(yīng)作用在支承面上,只有對剛性很好的工件才允許作用在幾個支承點所組成的平面內(nèi),以免夾緊力使工件彎曲或

溫馨提示

  • 1. 本站所有資源如無特殊說明,都需要本地電腦安裝OFFICE2007和PDF閱讀器。圖紙軟件為CAD,CAXA,PROE,UG,SolidWorks等.壓縮文件請下載最新的WinRAR軟件解壓。
  • 2. 本站的文檔不包含任何第三方提供的附件圖紙等,如果需要附件,請聯(lián)系上傳者。文件的所有權(quán)益歸上傳用戶所有。
  • 3. 本站RAR壓縮包中若帶圖紙,網(wǎng)頁內(nèi)容里面會有圖紙預(yù)覽,若沒有圖紙預(yù)覽就沒有圖紙。
  • 4. 未經(jīng)權(quán)益所有人同意不得將文件中的內(nèi)容挪作商業(yè)或盈利用途。
  • 5. 眾賞文庫僅提供信息存儲空間,僅對用戶上傳內(nèi)容的表現(xiàn)方式做保護(hù)處理,對用戶上傳分享的文檔內(nèi)容本身不做任何修改或編輯,并不能對任何下載內(nèi)容負(fù)責(zé)。
  • 6. 下載文件中如有侵權(quán)或不適當(dāng)內(nèi)容,請與我們聯(lián)系,我們立即糾正。
  • 7. 本站不保證下載資源的準(zhǔn)確性、安全性和完整性, 同時也不承擔(dān)用戶因使用這些下載資源對自己和他人造成任何形式的傷害或損失。

評論

0/150

提交評論