【正文】
在下文中,將簡(jiǎn)要介紹明可夫斯基和,以及它在帶料排樣設(shè)計(jì)中的應(yīng)用,和它在成對(duì)零件間嵌套問(wèn)題的延伸的描述。這種原理的方法具有一定局限性,盡管如此,在這種具有局限性下的設(shè)計(jì)中所產(chǎn)生較多的工藝廢料不能被避免,這些額外損失的材料導(dǎo)致了設(shè)計(jì)方案無(wú)法達(dá)到最佳化。理想情況下,材料應(yīng)該被充分利用。 relative to the other, defines all feasible relative positions between the pair of blanks. A corollary of this property is that if the Minkowski sum of a single part is calculated. With its negative, ., . (A plete explanation of these properties of the Minkowski sum is given in [15].) These observations were the basis for the algorithm for optimally nesting a single part on a strip.The situation when nesting pairs of parts is more plex, since not only do the optimal orientations of the blanks and the strip width need to be determined, but the optimal relative position of the two blanks needs to be determined as well. To solve this problem, an iterative algorithm is suggested:Given: Blanks A and B (where B=–A when a blank is paired with itself at 180186。謝 辭首先,感謝各位老師特別是我的指導(dǎo)老師葛述卿在這一段時(shí)間給予無(wú)私的我的知識(shí)和對(duì)我?guī)椭椭笇?dǎo),并向他致于深深的敬意,以后到社會(huì)上我一定努力工作,不辜負(fù)他給予我寄予的厚望!光陰似箭,歲月如梭,三年的大學(xué)生活一晃而過(guò),而我也即將離開可敬的老師和熟悉的同學(xué)踏入不是很熟悉的社會(huì)中去。再次,上模的裝配,裝配的過(guò)程和前面加工過(guò)程一樣,總結(jié)起來(lái)就是要先把要裝配的各個(gè)部分定位劃線,再淬火,線切割加工。裝配時(shí),先在壓力機(jī)上將凸模壓入固定板內(nèi),檢查凸模的垂直度,然后將固定板的上平面與凸模尾部一齊磨平,為了保持凸模刃口鋒利,還應(yīng)將模的端面磨平。用這種方式定距。圖34 卸料板 卸料螺釘?shù)倪x用卸料板上設(shè)置4個(gè)卸料螺釘M12100mm,d為16mm,螺紋部分為1612 mm??刂茥l料的送進(jìn)步距采用擋料銷初定距,由操作者利用導(dǎo)料銷和擋料銷實(shí)現(xiàn)精定距。落料以凹模為基準(zhǔn)件,根據(jù)凹模刃口磨損后的尺寸變大(A類)、變?。˙類)、不變(C類)三種情況,將零件圖中各尺寸進(jìn)行分類;A類尺寸:,B類尺寸:C類尺寸:凹模刃口尺寸計(jì)算如下:=()=(mm) =()=(mm) =(220. )=(mm) =(14+)=(mm) =(+)=(mm)凸模的刃口尺寸按凹模的實(shí)際尺寸配制,~。采用級(jí)進(jìn)模生產(chǎn)。分離工序的目的是在沖壓過(guò)程中將沖壓件與板料按一定的輪廓線進(jìn)行分離:分離工序又可分為落料、沖孔和剪切等。沖壓是在室溫下。本設(shè)計(jì)是第一工序(沖裁)的模具。與切削加工相比,冷沖壓靠模具和設(shè)備完成加工過(guò)程,所以具有生產(chǎn)效率高、加工成本低、材料利用率高 、產(chǎn)品一致性好、操作簡(jiǎn)單、便于實(shí)現(xiàn)機(jī)械化與自動(dòng)化等一系列優(yōu)點(diǎn)。,切斷模,剖切模,切口模,整修模,精沖模.按工序組合程度分。直排,斜排,直對(duì)排和混合排,.根據(jù)零件的形狀和復(fù)雜程度,本設(shè)計(jì)我采用直排的方式排樣。由于該彈性頂出裝置在沖裁時(shí)能壓住工件,并及時(shí)地將工件從凹模內(nèi)頂出,因此可使沖出的工件表面平整。熱處理硬度為40~,導(dǎo)料板的進(jìn)料端安裝有承料板。這種結(jié)構(gòu)的頂件力容易調(diào)節(jié),工作可靠,沖件平直度較高。第4章 模具的裝配和調(diào)整要制造出一副合格的冷沖模,除了要保證模具零件的加工精度外,還必須做好裝配工作。具體的裝配如下:首先,凸、凹模的預(yù)裝配,這個(gè)過(guò)程就是仔細(xì)檢查一下各凸模形狀及尺寸以及凹模形孔,是否符合圖紙要求的尺寸精度、形狀。最后,裝機(jī)試沖并根據(jù)試沖結(jié)果作相應(yīng)的調(diào)整。由于資質(zhì)有限,很多知識(shí)掌握的不是很牢固,因此在設(shè)計(jì)中難免要遇到很多難題,由于有了課程設(shè)計(jì)的經(jīng)驗(yàn)及老師的不時(shí)指導(dǎo)和同學(xué)的熱心幫助下,克服了一個(gè)又一個(gè)的困難,使我的畢業(yè)設(shè)計(jì)日趨完善。這種計(jì)算方法可以預(yù)示在帶料中結(jié)構(gòu)廢料的位置及形狀,以及工藝廢料的位置和最佳寬度。此項(xiàng)任務(wù)較為復(fù)雜,盡管如此,在設(shè)計(jì)中改變搭邊值以后能夠改變步距 (帶料中鄰近零件之間的距離) 以及帶料寬度。 (由于對(duì)稱),然后從中選出最佳排樣方法。) ,零件A周圍和接著零件B周圍參考點(diǎn)所連接而成的軌跡。這些計(jì)算方法基于建筑幾何學(xué)中一個(gè)外形從另外一個(gè)上‘發(fā)展’出來(lái)。前期工作曾經(jīng), 帶料排樣設(shè)計(jì)問(wèn)題需要通過(guò)手工來(lái)解決。但材料不能被完全利用到零件上,因?yàn)榱慵灰?guī)則的外形必須被包含在帶料內(nèi)。, and when two different parts are nested together. In this paper we describe a new algorithm that provides the optimal strip layout for these two cases. Previous WorkOriginally, strip layout problems were solved manually, for example, by cutting blanks from cardboard and manipulating them to obtain a good layout. The introduction of puters into the design process led to algorithmic approaches. Perhaps the first was to fit blanks into rectangles, then fit the rectangles along the strip[2]. Variations of this approach have involved fitting blanks into nonoverlapping posites of rectangles [3], convex polygons [4,5] and known interlocking shapes[6]. A fundamental limitation exists with this approach, however, in that the enclosing shape adds material to the blank that cannot be removed later during the layout process. This added material may prevent optimal layouts from being found.A popular approach to performing strip layout is the incremental rotation algorithm [610, 16]. In it, the blank, or blanks, are rotated by a fixed amount, such as 2186。通過(guò)對(duì)正裝下頂出落料模的設(shè)計(jì),使我對(duì)落料模有了深刻的認(rèn)識(shí),特別是這種正裝下頂出落料模具的設(shè)計(jì)。然后放在一邊待用。裝配時(shí),先在壓力機(jī)上將模柄壓入,再加工定位銷釘孔或螺紋孔。下模部分由下模座、凹模、頂件器等組成。圖33 凹模圖圖33中起定距的擋料銷選用標(biāo)準(zhǔn)件,規(guī)格為816mm 材料45鋼熱處理4348HRC。該彈簧規(guī)格為:外徑:D=36mm,鋼絲直徑:d=.自由高度:H0=80mm裝配高度:H2=H0?Hpre=8017=63mm表31 彈簧數(shù)據(jù)表序號(hào)H0/mmH1/mm?Hmax= H0 H1?Hpre(Ppre=600N)Ztotal=?Hpre+HW+?Hrep574510586013598017601006535236113030 注:HW=t+1=+1= mm, ?Hrep=6 mm模架選用后側(cè)導(dǎo)拄標(biāo)準(zhǔn)模架:上模座:LBH=200mm200mm45mm下模座:LBH=200mm200mm50mm導(dǎo)拄:dL=32mm160mm,導(dǎo)套:dLD=32mm105mm43mm模架的閉合高度:170~210mm。/221422 773586條料寬度BB=126+22130步距SS=34+ 材料的利用率一個(gè)步距的材料利用率100﹪ (21) 100﹪ =﹪式中 A沖裁件面積; n一個(gè)步距內(nèi)沖裁件數(shù)目; b條料寬度; h進(jìn)距. 沖裁力 該模具采用單工序落料模,擬選擇彈性卸料卸下工件,沖壓力的計(jì)算如下,由[1]p69可得沖裁力 : F=KLt (22)式中:F——沖裁力L——是沖裁周邊的長(zhǎng)度,這里面為總長(zhǎng)度=126mm+82mm+22πmm +14πmm+412mm=t————材料的抗剪強(qiáng)度取500MPaK——安全系數(shù)是考慮到實(shí)際生產(chǎn)中,模具間隙值的波動(dòng)和不均勻、刃口的磨損、板料力學(xué)性能和厚度波動(dòng)等因素的影響而給出的修正系數(shù)。沖壓工藝方案的確定該工件包括落料,切邊兩個(gè)基本工序,可有以下三種工藝方案:方案一:落料。由于 冷沖壓不需要加熱,也不想切削加工那樣,將大量的金屬切成碎屑而消耗大量能量,所以它是一種節(jié)能的加工方法;沖壓制品所用的原材料是冶金廠大量生產(chǎn)的廉價(jià)的鋼板和鋼帶,在沖壓加工中材料表面質(zhì)量不受破壞,故沖壓件的表面質(zhì)量好,著是任何其他加工方法所不能競(jìng)爭(zhēng)的。模具分為沖壓模具、熱鍛模具、塑料模具、鑄造模具、橡膠模具和玻璃模具等。據(jù)統(tǒng)計(jì),我國(guó)(未包括臺(tái)灣、香港、澳門)現(xiàn)有模具廠已超過(guò)1700家,從業(yè)人員達(dá)60多萬(wàn)人。據(jù)近年來(lái)的統(tǒng)計(jì),美、日等發(fā)達(dá)國(guó)家的模具工業(yè)年產(chǎn)值已經(jīng)超過(guò)機(jī)床工業(yè)產(chǎn)值的6%~12%。30鋼屬于低碳鋼,適用于沖壓生產(chǎn)。,下面對(duì)毛胚的搭邊值進(jìn)行確定,各部分尺寸的確定由[1]=2mm,工作間a1==130mm,一個(gè)步距的長(zhǎng)度為s=表21 毛坯計(jì)算表項(xiàng)目公式結(jié)果備注沖裁件的面積AA=12612+8222+ 22178。并經(jīng)過(guò)計(jì)算可得下列數(shù)據(jù):由表46中數(shù)據(jù)可知,序號(hào)59~61的彈簧均滿足?Hmax≥Ztotal,根據(jù)模具結(jié)構(gòu)確定使用59號(hào)彈簧。擋料銷采用H7/m6安裝在落料凹模端面,與卸料板的配合為H9/h8,露出凹模端面高度為3 mm。卸料方式采用卸料螺釘彈性卸料。模柄與上模座的配合要求是H7/m6。然后,將凸模壓入固定板凸模固定板的相應(yīng)孔內(nèi),在墊板上鉆孔,將外型凸模固定在墊板上,在與卸料板穿在一起。也使我學(xué)會(huì)了設(shè)計(jì)過(guò)程中對(duì)資料的查詢和運(yùn)用。 for example, in a stamping operation running at 200 strokes per minute, a savings of just 10 grams of material per part will accumulate into a savings of more than a tonne of raw material per eighthour shift. The material utilization is set during the tooling design stage, and remains fixed for the (usually long) life of the tool. Thus, there is significant value in determining the optimal strip layout before tooling is built.This task is plicated, however, since changing each variable in the layout can change both the pitch (distance along the strip between adjacent parts) and strip width simultaneously. Evaluating layout efficiency manually is extremely challenging, and while exact optimal algorithms have been described for the layout of a single part on a strip, so far only approximate algorithms ha