3865 枳殼自動切割機(jī)的設(shè)計(jì)
3865 枳殼自動切割機(jī)的設(shè)計(jì),枳殼,自動,切割機(jī),設(shè)計(jì)
枳殼自動切割機(jī)的設(shè)計(jì)本 科 畢 業(yè) 設(shè) 計(jì)題目: 枳殼自動切割機(jī)的設(shè)計(jì) 學(xué) 院: 工 學(xué) 院 姓 名: 徐杰峰 學(xué) 號: 20050456 專 業(yè): 機(jī)械設(shè)計(jì)制造及其自動化 年 級: 05 級 指導(dǎo)教師: 趙進(jìn)輝 二 OO 九年 五 月枳殼自動切割機(jī)的設(shè)計(jì)摘 要枳殼為蕓香科植物枸橘、酸橙、香圓或玳玳花等將近成熟的果實(shí)。植物形態(tài)像“枸橘” 、 “枳實(shí)” 、 “香櫞” 、 “玳玳花”條。而本次畢業(yè)設(shè)計(jì)是關(guān)于枳殼自動切割機(jī)的設(shè)計(jì),是一種中藥飲片枳殼加工機(jī)械。該機(jī)結(jié)構(gòu)緊湊,設(shè)計(jì)簡單,易操作,主要由機(jī)架,傳動機(jī)構(gòu),壓料機(jī)構(gòu),傳送機(jī)構(gòu),切割機(jī)構(gòu)組成。其特征是將從料斗進(jìn)入切割槽的枳殼進(jìn)行剖半處理,然后將剖半的枳殼通過輸送槽輸送到出料口陰干、風(fēng)干或微火烘干。這樣就能以工業(yè)生產(chǎn)規(guī)模將枳殼自鮮果經(jīng)剖半直接加工成半球狀,工作效率高,成品質(zhì)量高而穩(wěn)定,使手工制作枳殼飲片的狀況得到根本改觀。加工料 78 月采收時直徑為 56 厘米,烘干后直徑為 35cm,形狀為球形,厚 0.41.3cm。這就對機(jī)械加工提供了數(shù)據(jù)要求:1出料口大小在 25 厘米。2切割刀選用 0.20.4 厘米厚高硬度材料。3. 該機(jī)的整體結(jié)構(gòu)造型要求其長寬高不能大于 1.2 米。在枳殼自動切割機(jī)的設(shè)計(jì)、制造以及應(yīng)用方面,目前我國與國外先進(jìn)水平相比仍有較大差距,國內(nèi)在設(shè)計(jì)制造枳殼自動切割機(jī)過程中存在著很多不足。本次枳殼自動切割機(jī)設(shè)計(jì)代表了設(shè)計(jì)的一般過程, 對今后的選型設(shè)計(jì)工作有一定的參考價值。關(guān)鍵詞:枳殼自動切割機(jī);傳送鏈;割刀枳殼自動切割機(jī)的設(shè)計(jì)AbstractAurantii for Rutaceae Poncirus plants, lime, or Turpinia Dai Dai spent nearly ripe fruit and so on. Plant morphology such as Poncirus, bitter orange, citron, Dai Dai Hua section. And the graduation project is about the automatic cutting machine Aurantii design, is a traditional Chinese medicine processing machinery Aurantii Pieces.It is compact and is designed to be simple, easy-to-use, mainly by the rack, transmission, body binder, transmission organizations, cutting agencies. Characterized by cutting from the hopper into the trough of the Aurantii treatment for post-mortem, and then a half Aurantii autopsy groove through the transmission of material transported to dry mouth, dry or drying wei huo.This will be an industrial scale of production by Poncirus trifoliata fruit from the semi-direct post-mortem into hemispherical processing, efficient and stable high quality products to make hand-made pieces Aurantii fundamentally changed the situation.Processing of materials from 7 to harvesting in August, when a diameter of 5 to 6 centimeters in diameter after drying for 3 5cm, for the spherical shape, thickness 0.4 1.3cm. This provides a mechanical processing of data requirements:1. Entrance and exit of 10 cm in size. 2. Cutter selection of 0.2 0.4 cm thick high hardness materials. 3. It shapes the overall structure of its dimensions can not be greater than 1.2 meters.Aurantii automatic cutting machine in the design, manufacture and application in China, compared with foreign advanced level there is still a wide gap between the domestic manufacturers in the design process Aurantii automatic cutting machine, there are many deficiencies.The automatic cutting machine Aurantii design on behalf of the general process of design, type design for the future that there is a reference value.Key words: Automatic cutting machine Aurantii; transmission chain; cutting knife枳殼自動切割機(jī)的設(shè)計(jì)目 錄1 緒論 .11.1 藥理作用 .11.1.1 對心血管系統(tǒng)的作用 .11.1.2 對心、腦、腎等血流量的影響 .11.1.3 利尿作用 .21.1.4 對胃腸平滑肌的作用 .21.1.5 對子宮平滑肌的作用 .21.1.6 抗變態(tài)反應(yīng)的作用 .21.2 設(shè)計(jì)任務(wù) .21.2.1 設(shè)計(jì)任務(wù) .21.2.2 設(shè)計(jì)要求 .21.2.3 設(shè)計(jì)步驟 .32.總體方案及工作原理 .42.1 總體結(jié)構(gòu) .42.2 工作原理 .43.機(jī)械的設(shè)計(jì)與計(jì)算 .53.1 機(jī)架的設(shè)計(jì) .53.1.1 機(jī)架的分類 .53.1.2 機(jī)架上承受著力和和力矩(彎矩及轉(zhuǎn)矩) .63.2 傳動機(jī)構(gòu)的設(shè)計(jì) .73.2.1 普通 V 帶的傳動設(shè)計(jì) .83.3 傳送機(jī)構(gòu)的設(shè)計(jì) .103.3.1 鏈傳動的設(shè)計(jì) .113.3.2 軸的設(shè)計(jì) .133.4 切割機(jī)構(gòu)的設(shè)計(jì) .163.4.1 飛輪的設(shè)計(jì) .163.4.2 圓形割刀的設(shè)計(jì) .173.5 進(jìn)料口和出料口的設(shè)計(jì) .17總結(jié) .18參考文獻(xiàn) .19致謝 .20枳殼自動切割機(jī)的設(shè)計(jì)11 緒論枳殼自動切割機(jī)是連續(xù)運(yùn)行的切割設(shè)備,在中藥的制作方面主要用來對枳殼進(jìn)行剖半處理,烘干。能以工業(yè)生產(chǎn)規(guī)模將枳殼自鮮果經(jīng)剖半直接加工成半球狀,工作效率高,成品質(zhì)量高而穩(wěn)定,使手工制作枳殼飲片的狀況得到根本改觀。枳殼為蕓香科植物枸橘、酸橙、香圓或玳玳花等將近成熟的果實(shí)。植物形態(tài)像“枸橘” 、 “枳實(shí)” 、 “香櫞” 、 “玳玳花”條。78 月間采收,直徑 56 厘米,從中部橫切成兩半,陰干、風(fēng)干或微火烘干。本品呈半球形,直徑35cm。外果皮棕褐色或褐色,有顆粒狀突起,突起的頂端有凹點(diǎn)狀油室;有明顯的花柱殘跡或果梗痕。切面中果皮黃白色,光滑而稍隆起,厚0.41.3cm,邊緣散有 12 列油室,瓤囊 712 瓣,少數(shù)至 15 瓣,汁囊干縮呈棕色至棕褐色,內(nèi)藏種子。質(zhì)堅(jiān)硬,不易折斷。氣清香,味苦、微酸。其制成的枳殼飲片功能主治:理氣寬中,行滯消脹。用于胸脅氣滯,脹滿疼痛,食積不化,痰飲內(nèi)停;胃下垂,脫肛,子宮脫垂。1.1 藥理作用1.1.1 對心血管系統(tǒng)的作用枳殼中所含的 N甲基酪胺增加冠脈流量和腎血流血,降低心肌氧耗量和明顯的利尿作用。麻醉犬靜脈注射 0.02-0.5mg/kg,均呈升壓效應(yīng),劑量大,升壓明顯。靜脈灌注每分鐘 0.2mg/kg, ;腎血流量增加 75%,尿量增加一倍。有很強(qiáng)的誘發(fā)心肌節(jié)律的作用,其強(qiáng)度與腎上腺素相當(dāng),而比多巴胺和辛弗林強(qiáng)。枳殼中所含的辛弗林為腎上腺素 a-受體興奮劑,對心臟 B-受體也有一定的興奮作用。有收縮血管,產(chǎn)生升高血壓的作用。 1.1.2 對心、腦、腎等血流量的影響 麻醉犬靜脈注射枳實(shí)注射液(每 1ml4g 生藥)1ml/kg ,有顯著的增加腦血流量的作用。注射后腦血流量平均增加 82.620.56ml/100g 腦重/ 分鐘(P479mm(6) 驗(yàn)算小帶輪包角 =1800-( - )*57.30/a2D1=1800-(160-100)* 57.30/495 = 179.2所以合適。(7) 確定 V 帶的根數(shù) Z傳動比:i= / =960/594=1.621n2由此查表得:Po=0.28kw, Po=0.02kw , =1.00, =1.14。 kL枳殼自動切割機(jī)的設(shè)計(jì)10Z=P/(Po+ Po) =3.3/(0.28+0.02)*1.00*1.14=4.35kL取 Z=4 根。(8) 求作用在帶輪軸上的壓力 F0由表查得:q=0.06kg/mm 。 計(jì)算單根 V 帶張緊力:F=500P/Z (2.5/ -1)+q *vkv=500*3.3/4*5.024 *(2.5-1 )+0.06*5.024*5.024=56.25N作用在帶輪軸上的壓力為:F0=2Z F *sin /2=2*4*56.25*sin /2=450N179. 179.(9) V 帶輪的結(jié)構(gòu)設(shè)計(jì)V 帶輪設(shè)計(jì)的主要要求是質(zhì)量小,結(jié)構(gòu)工藝性好;無過大的鑄造內(nèi)應(yīng)力;質(zhì)量分布均勻,轉(zhuǎn)速高時要經(jīng)過動平衡;輪槽工作面粗糙度要合適,以減少帶的磨損;輪槽尺寸和槽面角應(yīng)保持一定得精度,以使載荷分布較為均勻等。帶輪的材料主要是鑄鐵,材料牌號為 HT200,小帶輪和大帶輪采用實(shí)心式,具體尺寸詳見圖紙。3.3 傳送機(jī)構(gòu)的設(shè)計(jì)傳送機(jī)構(gòu)基于鏈條設(shè)計(jì)原理,共分為兩層;外層為輸送槽,內(nèi)層為鏈條。如圖 3.4 所示三種立面中,左 1 為枳殼的切割槽,切割槽內(nèi)部空心設(shè)計(jì)為圓形直徑為 7 厘米厚 1 厘米,中間的是里層鏈條設(shè)計(jì),3 為地步立面,切割槽底部開口,開口寬為 0.3 厘米。 1. 輸送槽; 2.出料口; 3.進(jìn)料口圖 3.4枳殼自動切割機(jī)的設(shè)計(jì)113.3.1 鏈傳動的設(shè)計(jì)查表帶輪上功率的損失在 0.850.95 之間,即P=0.9*3=2.7kw, =600r/min。3n(1) 選擇鏈輪的齒數(shù)傳動比:i= / =1, =232Z3鏈的速度: v= /1.6= * p/60*1000vn= =314/12.7=24.723所以 = =25。Z(2) 確定節(jié)數(shù)初定中心距:a=40pLp=2a/p+( + )/2+p/a*( - )/2*3.14*( - )/2*3.142Z323Z23Z=80+25=105取 Lp=106 節(jié) (取偶數(shù)) 。(3) 確定鏈條節(jié)距 p由于鏈傳動中等沖擊,查表得工作情況系數(shù): =1.3,K鏈齒輪系數(shù): =1.11,鏈長度系數(shù): =1.06,多排系數(shù): =1.0,zKl m因此,實(shí)際工作條件下傳動功率為:Po= p/ * * =1.3*2.7/1.11*1.06*1.0=2.98kwzlm根據(jù) =600r/min 和功率 Po=2.98kw,可選滾子鏈型號為 08A,其節(jié)距為:3np=12.7mm。(4) 確定鏈長 L 和中心距 aL=LpP/1000=106*12.7/1000=1.35mm 22/423(3)/8(3)/apZLpZZ( ( ) /=12.7/4*(106-25)+(106-25)=514.35mm枳殼自動切割機(jī)的設(shè)計(jì)12中心距減小量: a=(0.0020.004)a=(0.0020.004) *514.35=1.032.06mm實(shí)際中心距:a=514.35-(1.032.06)=513.32512.29mm所以取 a=513mm。(5) 鏈速v= /1.6=5.024/1.6=3.14m/sv(6) 求作用在軸上的壓力 Fq工作拉力: F=1000P/V=1000 *2.7/3.14=859.9N 工作平穩(wěn),取壓軸力系數(shù):Kq=1.2 。軸上壓力:Fq=Kq*F=1.2*859.9=1031.88N(7) 根據(jù)鏈速 V=3.14m/s,鏈節(jié)距 p=12.7mm,所以鏈傳動選擇滴油潤滑。(8) 鏈輪結(jié)構(gòu)的設(shè)計(jì)(見圖)滾子鏈型號為 08A所以 p=12.7mm,滾子鏈外徑: =7.95mm,排距:Pt=14.38mm,1d套筒內(nèi)徑: =4.01mm,銷軸直徑: =3.96mm,內(nèi)鏈節(jié)內(nèi)寬:3d2=7.85mm,1b銷軸長度: =17.8mm,極限拉伸載荷:Q=1380daN,齒寬 7.3mm,4分度圓直徑:D=12.7/0.125=101.6mm齒頂圓直徑: (max)=D+1.25p-aD1d=101.6+1.25 *12.7-7.95=109.53mm(min)=D+(1-1.6/Z)p- a1=101.6+(1-1.6/25) *12.7-7.95=105.5mm分度圓弦齒高: (max)=(0.625+0.8/Z)p-0.5aH1d枳殼自動切割機(jī)的設(shè)計(jì)13=(0.625+0.8/25) *12.7-0.5*7.95=4.37mm(min)=0.5(p- )aH1d=0.5*(12.7-7.95)=2.38mm齒根圓直徑: =D- =1001.6-7.95=93.65mmfD1量柱測量矩 : =Dcos90/Z +rMr而量柱直徑 等于滾子外徑 ,所以 = mm。即 1dD0.1795=101.6*cos90/25+7.95= mmr 0.25933.3.2 軸的設(shè)計(jì)軸是機(jī)械傳動系統(tǒng)中的重要零件,設(shè)計(jì)時應(yīng)滿足合理的結(jié)構(gòu),足夠得強(qiáng)度,必要的強(qiáng)度和振動穩(wěn)定性,以及良好的工藝性等。總之,所謂軸的設(shè)計(jì),就是根據(jù)軸上零件的定位和固定要求,以及加工和裝配要求,合理定出軸的結(jié)構(gòu)外形和全部尺寸過程。(1) 選擇軸的材料軸的材料主要是碳素鋼和合金鋼,根據(jù)傳動功率和一些參數(shù),選擇材料。最常用的材料是 45 鋼,經(jīng)過調(diào)制處理,得到的組織具有良好的綜合力學(xué)性能,即有較高的強(qiáng)度,同時具有良好的塑性和韌性。因無特殊需要,選用 45 號鋼,調(diào)制處理,由機(jī)械設(shè)計(jì)表 11.1 查得,材料直徑200mm,硬度 217 255HBS,抗拉強(qiáng)度極限為 640Mpa,屈服強(qiáng)度極限為 275Mpa,彎曲疲勞極限為 275Mpa,剪切疲勞極限為 155Mpa。(2) 求輸出軸上功率 P,轉(zhuǎn)速 n,和轉(zhuǎn)矩 TP=2.7kw,n=600r/min所以: T=9550000*P/n=9550000*2.7/600=43000Nmm(3) 初步確定軸的最小直徑查表去 C=112,= = =18.5mmmind3/cP312.7/60枳殼自動切割機(jī)的設(shè)計(jì)14輸出軸的最小直徑顯然是安裝聯(lián)軸器處軸的直徑,為了使所選直徑與聯(lián)軸器的孔徑相適應(yīng),故需選擇聯(lián)軸器的型號。聯(lián)軸器計(jì)算轉(zhuǎn)矩 = *T,考慮caTK到轉(zhuǎn)矩變化很小,故取 =1.3。則 : K= *T =1.3*43000=55900NmmcaT按要求計(jì)算轉(zhuǎn)矩 Tca 應(yīng)小于聯(lián)軸器公稱轉(zhuǎn)矩的條件,查標(biāo)準(zhǔn) GB5014-85,選用 GL2 型彈性柱銷聯(lián)軸器,其公稱轉(zhuǎn)矩為 63000Nmm,聯(lián)軸器孔徑為 20mm,聯(lián)軸器長度為 52mm,與軸配合孔長度為 38mm。(4) 軸的結(jié)構(gòu)設(shè)計(jì)軸的速度為 5.024m/s,功率為 2.7kw。水平方向的受力:圖 3.5 水平方向受力簡圖A 和 D 點(diǎn)為軸兩端點(diǎn),B 處為鏈輪,C 處為大帶輪且鏈輪給軸上的壓力為=1031.88N,大帶輪給軸上的壓力為 =450N。bFF=0 , *900+ *820+ *410=0aMdcb=0 , *900- *490- *80=0bb= *cot ,因?yàn)?得角度很小,所以可以得出 趨于 0。c c所以得出:=1031.88*410/900=561.8NaF=1031.88*490/900=470.1Nd軸水平方向的彎矩計(jì)算:B 點(diǎn)彎矩為: =- *410=-561.8*410=-230.3NmbMa枳殼自動切割機(jī)的設(shè)計(jì)15C 點(diǎn)彎矩為: =- *820+ *(820-410)cMaFd=-561.8*820+1031.88*410=-37.6Nm垂直方向受力:= =450N1cF圖 3.6 垂直方向受力簡圖=0 , *900- *820+ *410=0aM1dF1c1bF=0 , - *490- *410+ *410=0b a所以得出: =940N , =410N1a1d軸垂直方向的彎矩計(jì)算:B 點(diǎn)彎矩為: =- *410=-940*410=-87Nm1baFC 點(diǎn)彎矩為: =- *80=-940*810=-176NmcM計(jì)算合成彎矩:B 點(diǎn)合成彎矩: =90.7Nm()bC 點(diǎn)合成彎矩: =176Nm()c是考慮扭矩和彎矩的加載情況及產(chǎn)生應(yīng)力的循環(huán)特性差異的系數(shù),取=0.6,T 為軸受到的扭矩,所以得:=90.7Nm , =177.9Nm1caM2ca校核軸的強(qiáng)度,根據(jù)彎矩的大小及軸的直徑選定 B 和 C 截面進(jìn)行強(qiáng)度校核。B 截面當(dāng)量彎矩應(yīng)力為:= /W= /0.1*d*d*d*0.95()sb1ca1ca枳殼自動切割機(jī)的設(shè)計(jì)16=90.7/0.1*32*32*32*0.95=32.3MpaC 截面當(dāng)量彎矩應(yīng)力為:= /W= /0.1*d*d*d*0.95()sc2aM2ca=177.7/0.1*38*38*38*0.95=37.8MPa由表查得,45 號鋼軸的彎曲應(yīng)力為 =60 Mpa,所以 B 和 C 截面均安全s(W 為軸的抗彎截面模量,因?yàn)?B 和 C 截面有鍵槽,考慮對軸強(qiáng)度削弱的影響,故 d 乘以 0.95。所以 B 和 C 截面均安全) 。圖 3.7 各彎矩簡圖3.4 切割機(jī)構(gòu)的設(shè)計(jì)切割機(jī)構(gòu)的設(shè)計(jì)分為三層:如下圖所示,最外層為飛輪,設(shè)置三種傳動比;中間層為圓形切割刀,采用高速合金鋼作為道具材料,刀片厚度不大于 0.2 厘米;第三層為傳送鏈輪。第一層與第二層間隙為 4.5 厘米,第二層與第三層間距為4.5 厘米。3.4.1 飛輪的設(shè)計(jì)飛輪的設(shè)計(jì)是根據(jù)機(jī)器實(shí)際所需的平均速度和許可的不均勻系數(shù)來確定飛輪的轉(zhuǎn)慣量,為了調(diào)節(jié)等效構(gòu)件的周期性速度波動或者為了節(jié)省動力起見,需安裝輪形飛輪。= =m*=( * + * )/4 *m/2=m/4 *( * +h*h)Jf1D2D枳殼自動切割機(jī)的設(shè)計(jì)17因?yàn)?h 比 d 小的多,故 =m*d*d/4。fJm 為飛輪質(zhì)量, 為其外徑,d 為平均直徑, 為內(nèi)徑,h 為輪緣厚度。1D2D查表輪形飛輪(設(shè)計(jì)手冊)得:m=3kg, =150,d=137.5mm, =125mm。12所以得: =3/4 *(137.5*137.5+25*25)=0.015kgmJ3.4.2 圓形割刀的設(shè)計(jì)枳殼的切割槽,切割槽內(nèi)部空心設(shè)計(jì)為圓形直徑為 7 厘米厚 1 厘米,切割槽底部開口,開口寬為 0.3 厘米。所以刀片厚度小于 0.3 厘米。在這里我取刀片的厚度為 0.2 厘米。鏈輪的齒頂圓直徑: (max)=109.53mm ,則aD圓形割刀的最大直徑為: (max)=109.53mm+7cm+1cm=189.53mm取圓形割刀的最小直徑: (min)=180mm由上面計(jì)算知:軸的最小直徑: = = =18.5mmmind3/cP312.7/60圓形刀片的內(nèi)徑 d 大于 ,我取 d=60mm,這樣就可設(shè)計(jì)出圓形割刀。i3.5 進(jìn)料口和出料口的設(shè)計(jì)進(jìn)料口上端口直徑為 40cm,下端口直徑為 8cm,高 25cm,壁厚 0.4cm。出料口寬 25cm,長 50cm,壁厚 0.4cm,見圖 3.4。枳殼自動切割機(jī)的設(shè)計(jì)18總 結(jié)經(jīng)過兩個月左右的準(zhǔn)備工作,在趙老師和同學(xué)的指導(dǎo)和幫助下,此次畢業(yè)設(shè)計(jì)順利完成。本次設(shè)計(jì)總體上所設(shè)計(jì)的方案是合理正確的,但是由于時間及資料的不足,更加上自身知識有限,難免有設(shè)計(jì)上的缺陷。實(shí)際應(yīng)用上會有很多問題,比如,加工工藝,制造成本,還有就是設(shè)備的穩(wěn)定性保證和壽命的預(yù)測。通過這些天的設(shè)計(jì),讓我再一次明白很多東西,但還是有許多不知其所以然,不知道為什么要這樣,這也許是我們什么都學(xué),什么都學(xué)不精,有點(diǎn)像猴子下山。當(dāng)然,每做一件事都事有收獲的。也許你現(xiàn)在還每察覺到,但卻影響了你。為了完成這個課題設(shè)計(jì),我花了很多時間,去圖書館查閱這方面的資料,上網(wǎng)下載有關(guān)案例。我做了比較充分的準(zhǔn)備,頭腦中以初具模型,但是,當(dāng)要真正地寫出來,卻犯難了,通過好幾次的通宵,終于做好了,有了那么點(diǎn)成就感。在這次課程設(shè)計(jì)過程中,我重新梳理了過去學(xué)過的知識,并溫習(xí)了 CAD 以及 Word 和 Excel 辦公軟件。更讓我明白了世上無難事,只要去做了,一定能行的道理!枳殼自動切割機(jī)的設(shè)計(jì)19參考文獻(xiàn)1 黃 平 , 朱 文 堅(jiān) 主 編 .機(jī) 械 設(shè) 計(jì) 基 礎(chǔ) M.華 南 理 工 大 學(xué) 出 版 社 , 20062 鄭 文 緯 , 吳 克 堅(jiān) 主 編 .機(jī) 械 原 理 M.高 等 教 育 出 版 社 , 第 1 版3 譚 建 榮 等 編 .圖 學(xué) 基 礎(chǔ) 教 程 M.高 等 教 育 出 版 社 , 第 1 版4 張 展 主 編 .機(jī) 械 設(shè) 計(jì) 通 用 手 冊 M.中 國 勞 動 出 版 社 , 19945 曹 志 超 主 編 .常 用 機(jī) 械 電 器 實(shí) 用 手 冊 M.化 學(xué) 工 業(yè) 出 版 社 , 20006 陸 玉 主 編 .機(jī) 械 設(shè) 計(jì) 課 程 設(shè) 計(jì) M.機(jī) 械 工 業(yè) 出 版 社 , 20067 于 永 泗 等 主 編 .機(jī) 械 工 程 材 料 M.大 連 理 工 大 學(xué) 出 版 社 , 20068 曾 志 新 主 編 .機(jī) 械 制 造 技 術(shù) 基 礎(chǔ) M.武 漢 理 工 大 學(xué) 出 版 社 , 2002 9 楊 明 忠 等 主 編 .機(jī) 械 設(shè) 計(jì) M. 武 漢 理 工 大 學(xué) 出 版 社 , 200110 劉 鴻 文 主 編 .材 料 力 學(xué) M.高 等 教 育 出 版 社 , 第 4 版11 中 國 農(nóng) 業(yè) 機(jī) 械 化 科 學(xué) 研 究 院 編 .實(shí) 用 機(jī) 械 設(shè) 計(jì) 手 冊 M.中 國 農(nóng) 業(yè) 機(jī) 械 出版 社12 成 大 先 主 編 .機(jī) 械 設(shè) 計(jì) 手 冊 M.化 學(xué) 工 業(yè) 出 版 社 , 第 三 版13 維 普 資 訊 http:/www.cqvip.com14 北京農(nóng)業(yè)機(jī)械化學(xué)院主編.農(nóng)業(yè)機(jī)械學(xué)M.中國農(nóng)業(yè)出版社, 200115 哈 工 大 理 論 力 學(xué) 交 研 室 編 .理 論 力 學(xué) M.高 等 教 育 出 版 社 , 第 6 版16 汝 元 功 , 唐 照 民 主 編 .機(jī) 械 設(shè) 計(jì) 手 冊 M.高 等 教 育 出 版 社枳殼自動切割機(jī)的設(shè)計(jì)20致 謝在 這 次 畢 業(yè) 設(shè) 計(jì) 過 程 中 ,除 了 完 成 要 求 的 設(shè) 計(jì) 任 務(wù) 外 ,讓 自 己 的 專業(yè) 知 識 得 到 了 一 定 的 鞏 固 和 提 高 ,在 一 些 認(rèn) 知 深 度 上 也 有 所 增 強(qiáng) ,但畢 竟 這 只 是 事 件 本 身 而 已 ,更 難 人 可 貴 的 是 在 設(shè) 計(jì) 過 程 中 接 觸 的 人 ,在 與 他 們 的 相 處 過 程 中 ,收 獲 的 就 不 單 單 是 本 專 業(yè) 或 相 關(guān) 專 業(yè) 知 識 ,還 有 更 珍 貴 是 對 自 己 在 今 后 的 路 上 要 面 對 的 為 人 處 事 ,解 決 問 題 的 思路 與 方 案 ,還 有 個 人 修 養(yǎng) 方 面 等 都 受 到 了 很 大 的 啟 發(fā) 為 此 我 要 特 別 感 謝 趙 進(jìn) 輝 老 師 , 其 導(dǎo) 師 風(fēng) 范 和 人 格 魅 力 , 無 時 無 刻 不在 設(shè) 計(jì) 流 程 中 影 響 著 我 , 雖 然 趙 老 師 公 務(wù) 繁 忙 , 但 每 次 去 老 師 辦 公 室 時 ,都 會 指 導(dǎo) 和 催 促 我 抓 緊 時 間 完 成 設(shè) 計(jì) , 可 見 關(guān) 切 之 至 ! 還 有 在 設(shè) 計(jì) 過 程中 一 直 指 導(dǎo) 我 的 同 學(xué) , 他 們 的 悉 心 指 教 , 把 每 個 細(xì) 節(jié) 都 講 的 較 清 楚 , 無以 言 表 , 只 想 再 說 一 聲 謝 謝 !相 信 你 們 的 教 導(dǎo) 、 幫 助 與 支 持 會 激 發(fā) 我 更 好 的 前 行 , 謝 謝 !Automobile Brake SystemThe braking system is the most important system in cars. If the brakes fail, the result can be disastrous. Brakes are actually energy conversion devices, which convert the kinetic energy (momentum) of the vehicle into thermal energy (heat).When stepping on the brakes, the driver commands a stopping force ten times as powerful as the force that puts the car in motion. The braking system can exert thousands of pounds of pressure on each of the four brakes.Two complete independent braking systems are used on the car. They are the service brake and the parking brake.The service brake acts to slow, stop, or hold the vehicle during normal driving. They are foot-operated by the driver depressing and releasing the brake pedal. The primary purpose of the brake is to hold the vehicle stationary while it is unattended. The parking brake is mechanically operated by when a separate parking brake foot pedal or hand lever is set.The brake system is composed of the following basic components: the “master cylinder” which is located under the hood, and is directly connected to the brake pedal, converts driver foots mechanical pressure into hydraulic pressure. Steel “brake lines” and flexible “brake hoses” connect the master cylinder to the “slave cylinders” located at each wheel. Brake fluid, specially designed to work in extreme conditions, fills the system. “Shoes” and “pads” are pushed by the slave cylinders to contact the “drums” and “rotors” thus causing drag, which (hopefully) slows the car.The typical brake system consists of disk brakes in front and either disk or drum brakes in the rear connected by a system of tubes and hoses that link the brake at each wheel to the master cylinder (Figure).Basically, all car brakes are friction brakes. When the driver applies the brake, the control device forces brake shoes, or pads, against the rotating brake drum or disks at wheel. Friction between the shoes or pads and the drums or disks then slows or stops the wheel so that the car is braked. In most modern brake systems (see Figure 15.1), there is a fluid-filled cylinder, called master cylinder, which contains two separate sections, there is a piston in each section and both pistons are connected to a brake pedal in the drivers compartment. When the brake is pushed down, brake fluid is sent from the master cylinder to the wheels. At the wheels, the fluid pushes shoes, or pads, against revolving drums or disks. The friction between the stationary shoes, or pads, and the revolving drums or disks slows and stops them. This slows or stops the revolving wheels, which, in turn, slow or stop the car.The brake fluid reservoir is on top of the master cylinder. Most cars today have a transparent r reservoir so that you can see the level without opening the cover. The brake fluid level will drop slightly as the brake pads wear. This is a normal condition and no cause for concern. If the level drops noticeably over a short period of time or goes down to about two thirds full, have your brakes checked as soon as possible. Keep the reservoir covered except for the amount of time you need to fill it and never leave a cam of brake fluid uncovered. Brake fluid must maintain a very high boiling point. Exposure to air will cause the fluid to absorb moisture which will lower that boiling point.The brake fluid travels from the master cylinder to the wheels through a series of steel tubes and reinforced rubber hoses. Rubber hoses are only used in places that require flexibility, such as at the front wheels, which move up and down as well as steer. The rest of the system uses non-corrosive seamless steel tubing with special fittings at all attachment points. If a steel line requires a repair, the best procedure is to replace the compete line. If this is not practical, a line can be repaired using special splice fittings that are made for brake system repair. You must never use copper tubing to repair a brake system. They are dangerous and illegal.Drum brakes, it consists of the brake drum, an expander, pull back springs, a stationary back plate, two shoes with friction linings, and anchor pins. The stationary back plate is secured to the flange of the axle housing or to the steering knuckle. The brake drum is mounted on the wheel hub. There is a clearance between the inner surface of the drum and the shoe lining. To apply brakes, the driver pushes pedal, the expander expands the shoes and presses them to the drum. Friction between the brake drum and the friction linings brakes the wheels and the vehicle stops. To release brakes, the driver release the pedal, the pull back spring retracts the shoes thus permitting free rotation of the wheels.Disk brakes, it has a metal disk instead of a drum. A flat shoe, or disk-brake pad, is located on each side of the disk. The shoes squeeze the rotating disk to stop the car. Fluid from the master cylinder forces the pistons to move in, toward the disk. This action pushes the friction pads tightly against the disk. The friction between the shoes and disk slows and stops it. This provides the braking action. Pistons are made of either plastic or metal. There are three general types of disk brakes. They are the floating-caliper type, the fixed-caliper type, and the sliding-caliper type. Floating-caliper and sliding-caliper disk brakes use a single piston. Fixed-caliper disk brakes have either two or four pistons.The brake system assemblies are actuated by mechanical, hydraulic or pneumatic devices. The mechanical leverage is used in the parking brakes fitted in all automobile. When the brake pedal is depressed, the rod pushes the piston of brake master cylinder which presses the fluid. The fluid flows through the pipelines to the power brake unit and then to the wheel cylinder. The fluid pressure expands the cylinder pistons thus pressing the shoes to the drum or disk. If the pedal is released, the piston returns to the initial position, the pull back springs retract the shoes, the fluid is forced back to the master cylinder and braking ceases.The primary purpose of the parking brake is to hold the vehicle stationary while it is unattended. The parking brake is mechanically operated by the driver when a separate parking braking hand lever is set. The hand brake is normally used when the car has already stopped. A lever is pulled and the rear brakes are approached and locked in the “on” position. The car may now be left without fear of its rolling away. When the driver wants to move the car again, he must press a button before the lever can be released. The hand brake must also be able to stop the car in the event of the foot brake failing. For this reason, it is separate from the foot brake uses cable or rods instead of the hydraulic system.Anti-lock Brake System Anti-lock brake systems make braking safer and more convenient, Anti-lock brake systems modulate brake system hydraulic pressure to prevent the brakes from locking and the tires from skidding on slippery pavement or during a panic stop.Anti-lock brake systems have been used on aircraft for years, and some domestic car were offered with an early form of anti-lock braking in late 1990s. Recently, several automakers have introduced more sophisticated anti-lock system. Investigations in Europe, where anti-lock braking systems have been available for a decade, have led one manufacture to state that the number of traffic accidents could be reduced by seven and a half percent if all cars had anti-lock brakes. So some sources predict that all cars will offer anti-lock brakes to improve the safety of the car. Anti-lock systems modulate brake application force several times per second to hold the tires at a controlled amount of slip; all systems accomplish this in basically the same way. One or more speed sensors generate alternating current signal whose frequency increases with the wheel rotational speed. An electronic control unit continuously monitors these signals and if the frequency of a signal drops too rapidly indicating that a wheel is about to lock, the control unit instructs a modulating device to reduce hydraulic pressure to the brake at the affected wheel. When sensor signals indicate the wheel is again rotating normally, the control unit allows increased hydraulic pressure to the brake. This release-apply cycle occurs several time per second to “pump” the brakes like a driver might but at a much faster rate.In addition to their basic operation, anti-lock systems have two other things in common. First, they do not operate until the brakes are applied with enough force to lock or nearly lock a wheel. At all other times, the system stands ready to function but does not interfere with normal braking. Second, if the anti-lock system fail in any way, the brakes continue to operate without anti-lock capability. A warning light on the instrument panel alerts the driver when a problem exists in the anti-lock system.The current Bosch component Anti-lock Braking System (ABS), is a second generation design wildly used by European automakers such as BWM, Mercedes-Benz and Porsche. ABS system consists of : four wheel speed sensor, electronic control unit and modulator assembly. A speed sensor is fitted at each wheel sends signals about wheel rotation to control unit. Each speed sensor consists of a sensor unit and a gear wheel. The front sensor mounts to the steering knuckle and its gear wheel is pressed onto the stub axle that rotates with the wheel. The rear sensor mounts the rear suspension member and its gear wheel is pressed onto the axle. The sensor itself is a winding with a magnetic core. The core creates a magnetic field around the winding, and as the teeth of the gear wheel move through this field, an alternating current is induced in the winding. The control unit monitors the rate o change in this frequency to determine impending brake lockup. The control units function can be divided into three parts: signal processing, logic and safety circuitry. The signal processing section is the converter that receives the alternating current signals form the speed sensors and converts them into digital form for the logic section. The logic section then analyzes the digitized signals to calculate any brake pressure changes needed. If impending lockup is sensed, the logic section sends commands to the modulator assembly. Modulator assembly The hydraulic modulator assembly regulates pressure to the wheel brakes when it receives commands from the control utuit. The modulator assembly can maintain or reduce pressure over the level it receives from the master cylinder, it also can never apply the brakes by itself. The modulator assembly consists of three high-speed electric solenoid valves, two fluid reservoirs and a turn delivery pump equipped with inlet and outlet check valves. The modulator electrical connector and controlling relays are concealed under a plastic cover of the assembly. Each front wheel is served by electric solenoid valve modulated independently by the control unit. The rear brakes are served by a single solenoid valve and modulated together using the select-low principle. During anti-braking system operation, the control unit cycles the solenoid valves to either hold or release pressure the brake lines. When pressure is released from the brake lines during anti-braking operation, it is routed to a fluid reservoir. There is one reservoir for the front brake circuit. The reservoirs are low-pressure accumulators that store fluid under slight spring pressure until the return delivery pump can return the fluid through the brake lines to the master cylinder. 譯 文汽車制動系統(tǒng)制動系統(tǒng)是汽車中最重要的系統(tǒng)。 如果制動失靈,結(jié)果可能是損失慘重的。制動器實(shí)際就是能量轉(zhuǎn)換裝置,它將汽車的動能(動量)轉(zhuǎn)化成熱能(熱量)。當(dāng)駕駛員踩下制動踏板,所產(chǎn)生的制動力是汽車運(yùn)動時動力的10倍。制動系統(tǒng)能對四個剎車系統(tǒng)中的每個施加數(shù)千磅的力。每輛汽車上使用兩個完全獨(dú)立的制動系統(tǒng),即行車制動器和駐車制動器。行車制動器起到減速、停車、或保持車輛正常行駛。制動器是由司機(jī)用腳踩、松制動器踏板來控制的。駐車制動器的主要作用就是當(dāng)車內(nèi)無人的時候,汽車能夠保持靜止。當(dāng)獨(dú)立的駐車制動器踏板或手桿,被安裝時,駐車制動器就會被機(jī)械地操作。制動系統(tǒng)是由下列基本的成分組成:位于發(fā)動機(jī)罩下方,而且直接地被連接到制動踏板的“制動主缸”把駕駛員腳的機(jī)械力轉(zhuǎn)變?yōu)橐簤毫Αd撝频摹爸苿庸苈贰焙陀腥嵝缘摹爸苿榆浌堋卑阎苿又鞲走B接到每個輪子的“制動輪缸”上。制動液, 特別地設(shè)計(jì)為的是工作在極端的情況,填充在系統(tǒng)中?!爸苿颖P”和“襯塊”是被制動輪缸推動接觸“圓盤”和“回轉(zhuǎn)體”如此引起緩慢的拖拉運(yùn)動, (希望)使汽車減慢速度。典型的制動系統(tǒng)布置有前后盤式,前盤后鼓式,各個車輪上的制動器通過一套管路系統(tǒng)連接到制動主缸上。基本上講,所有的汽車制動器都是摩擦制動器。當(dāng)司機(jī)剎車時,控制裝置會迫使制動蹄,或制動襯片與車輪處的旋轉(zhuǎn)的制動鼓或制動盤接觸。接觸后產(chǎn)生的摩擦使車輪轉(zhuǎn)動減慢或停止,這就是汽車的制動。在最基本的制動系統(tǒng)中,有一個制動主缸,這個主缸內(nèi)部填充制動液,并包含兩個部分,每個部分里都有一個活塞,兩個活塞都連接駕駛室里的制動踏板。當(dāng)制動踏板被踩下時,制動液會從制動主缸流入輪缸。在輪缸中,制動液推動制動蹄或制動襯片與旋轉(zhuǎn)的制動鼓或制動盤接觸。靜止的制動蹄或制動襯片與旋轉(zhuǎn)的制動鼓或制動盤之間產(chǎn)生摩擦力使汽車的運(yùn)動逐漸減緩或停止。制動液的裝置位于主缸的頂部。目前大多數(shù)的車都有一個容易看見的裝制動液的裝置,為的是不用打開蓋子就可以看得見制動液的油面。隨著制動踏板的運(yùn)動制動液就會緩慢的下降,正常情況下是這樣的。如果制動液在很短的時間內(nèi)下降得明顯或者下降了三分之二,那么就要盡快的檢查你的制動系統(tǒng)了。保持制動液裝置充滿制動液除非你需要維修它,制動液必須保持很高的沸點(diǎn)。位于在空氣中的制動液就會吸收空氣中的潮氣引起制動液低于沸點(diǎn)。制動液通過一系列的管路從主缸到達(dá)各車輪。橡膠軟管只用在需要彈力的地方,比如應(yīng)用在前輪。在車的行進(jìn)中上下來回運(yùn)動。系統(tǒng)的其它部分在所有的連接點(diǎn)上都應(yīng)用了無腐蝕性的無縫鋼管。如果鋼線需要修理的話,最好的方法就是代替這條線。如果這不符合實(shí)際,那么為了制動系統(tǒng)可以用特殊的裝置修理它。你不可以用銅管來修理制動系。它們是危險(xiǎn)也是不正確的。鼓式制動器包括制動鼓,一個輪缸,回拉彈簧,一個制動底版,兩個帶摩擦層的制動蹄。制動底版固定在輪軸外部的法蘭或轉(zhuǎn)向節(jié)。制動鼓固定在輪轂上。制動鼓的內(nèi)部表面與制動蹄的內(nèi)層之間有空隙。要使用制動器時,司機(jī)就要踩下踏板,這時輪缸擴(kuò)大制動片,對其施加壓力,是制動蹄觸碰制動鼓。制動鼓與摩擦片之間產(chǎn)生的摩擦制動了車輪,從而使汽車停止。要釋放制動器時,司機(jī)松開踏板,回拉彈簧拉回制動片,這樣車輪會自由轉(zhuǎn)動。盤式制動器包括制動盤而不是鼓,在它的兩面上各有一個薄的制動片或叫盤式制動器的制動片。制動片是靠擠住旋轉(zhuǎn)的制動盤來停住汽車。制動主缸里流出的制動液迫使活塞向里部的金屬盤移動,這便使摩擦片緊緊地貼住制動盤。這時制動片與制動盤產(chǎn)生的摩擦使汽車減速、停止,出現(xiàn)了制動行為?;钊纸饘倩蛩芰稀1P式制動器主要有三種,即:浮動卡鉗型、固定卡鉗型和滑動卡鉗型。浮動卡鉗型和滑動卡鉗型盤式制動器使用單活塞。固定卡鉗型盤式制動器既可以使用兩個活塞有可以使用四個活塞。制動系統(tǒng)是由機(jī)械能,液壓能或氣壓能裝置驅(qū)動的。在機(jī)械杠桿適合所有的汽車的駐車制動器中使用。當(dāng)踩下制動踏板時,杠桿就會推動制動器主缸的活塞給制動液施加壓力,制動液通過油管流入輪缸。制動液的壓力施加到輪缸活塞以使制動片被壓到制動鼓或制動盤上。如果松開踏板,活塞回到原來的位置上,回拉彈簧拉回制動片,制動液返回制動主缸,這樣制動停止。駐動制動器的主要作用是車內(nèi)無人時,使汽車靜止不動。如果車內(nèi)安裝的是獨(dú)立的駐車制動器,那么駐車制動器是由司機(jī)手動的控制。駐車制動器正常是當(dāng)車已經(jīng)停止時使用的。向后拉手閘,并把手柄卡在正確的位置上?,F(xiàn)在,即使離開汽車也不用害怕它會自己滑走。如果司機(jī)要再次啟車時,他必須在松開手桿之前按下按鈕。在行車制動器失靈的情況下,手閘必須能停住車。正因?yàn)檫@樣,手閘與腳閘分開,手閘使用的是繩索或杠桿而不是液力系統(tǒng)。防抱死制動系統(tǒng)是使汽車制動更安全、更方便的制動裝置,它既有調(diào)節(jié)制動系統(tǒng)的壓力來防止車輪被完全抱死的功能,又有防止輪胎在滑的路面上行駛或緊急停車時的滑動。防抱死制動系統(tǒng)最早應(yīng)用在航空飛行器上,而且在二十世紀(jì) 90 年代一些國內(nèi)的汽車內(nèi)也安裝了這種系統(tǒng)。近來,幾個汽車制造商引進(jìn)了更為復(fù)雜的防抱死系統(tǒng)。歐洲使用這種系統(tǒng)已有幾十年的時間,通過對其的調(diào)查,一位汽車制造商坦言,如果所有的汽車都安裝上防抱死制動系統(tǒng),那么交通事故的發(fā)生率會降低 7.5%。同時,一些權(quán)威人士預(yù)測這種系統(tǒng)會提高汽車的安全性。防抱死制動系統(tǒng)可以在一秒鐘內(nèi)調(diào)節(jié)幾次制動時車輪上的受力,使車輪的滑移受到控制,而且所有的系統(tǒng)基本上都以相同的方式完成。每個車輪都會有一個傳感器,電子控制裝置能連續(xù)檢測來自車輪傳感器傳來的脈沖電信號,并將它們處理轉(zhuǎn)換成和輪速成正比的數(shù)值;如果其中一個傳感器的信號不斷下降,那么這就表明了相應(yīng)的輪胎趨于抱死,這時電子控制裝置向該車輪的制動器發(fā)出降低壓力的指令。當(dāng)信號顯示車輪轉(zhuǎn)速恢復(fù)正常時,電子控制裝置會增加制動器的液壓。這種循環(huán)像司機(jī)一樣調(diào)節(jié)制動器,但它的速度更快,達(dá)到了每秒循環(huán)數(shù)次。防抱死制動系統(tǒng)除了上面基本操作,還有兩個特點(diǎn)。首先,當(dāng)制動系統(tǒng)的壓力上升到使輪胎抱死或即將抱死的時候,防抱死制動系統(tǒng)才會啟動;當(dāng)制動系統(tǒng)在正常情況下,防抱死制動系統(tǒng)停止運(yùn)作。其次,如果防抱死制動系統(tǒng)有問題時,制動器會獨(dú)立地繼續(xù)運(yùn)行。但控制板上的指示燈亮起提醒司機(jī)系統(tǒng)出現(xiàn)問題。目前歐洲汽車生產(chǎn)商,如:寶馬、奔馳、寶時捷等廣泛使用的是波許(Bosch)防抱死制動系統(tǒng)。這種系統(tǒng)基本組成包括車輪轉(zhuǎn)速傳感器,電子控制裝置和調(diào)節(jié)裝置。每個有一個向電子控制裝置發(fā)出車輪轉(zhuǎn)動情況的信號的傳感器,它一般由磁感應(yīng)傳感頭和齒圈組成。前面的傳感器安在輪轂上,齒圈安在輪網(wǎng)上。后面的傳感器安在后部的監(jiān)測系統(tǒng)上,齒圈安在輪軸上。傳感器本身是纏繞電磁核的電線圈,電磁核才線圈的周圍產(chǎn)生磁場。當(dāng)齒圈的齒移動到磁場時,就會改變線圈的電流。電子控制裝置會監(jiān)測這種變化,然后判斷車輪是否即將抱死。電子控制裝置有三個作用,即:信號的處理,編輯和安全防護(hù)。信號的處理起到轉(zhuǎn)換器的作用,它是將接受的脈沖電信號處理轉(zhuǎn)換成數(shù)值,為編輯做準(zhǔn)備。編輯就是分析這些數(shù)值,計(jì)算出需要制動壓力。如果檢測出車輪即將抱死,電控裝置就會計(jì)算出數(shù)值向調(diào)節(jié)裝置發(fā)出指令。調(diào)節(jié)裝置當(dāng)接受到電子控制裝置的指令后,液壓執(zhí)行裝置會調(diào)節(jié)制動輪缸的液壓的大小。調(diào)節(jié)裝置能保持或減小來自制動主缸的液壓,而裝置本身是不能啟用制動器的。這種裝置有三個高速率的電磁閥,兩個油液存儲器和一個帶有內(nèi)外檢測閥的傳動泵。調(diào)節(jié)裝置中的電子連接器隱藏在塑料蓋下。每個電磁閥都是其獨(dú)立控制的,并作用于前輪。后部的制動輪缸受到一個電磁閥控制,并依照-的原理進(jìn)行調(diào)節(jié)。當(dāng)防抱死制動系統(tǒng)運(yùn)行時,電子控制裝置會使電磁閥循環(huán)運(yùn)作,這樣既能收回又能釋放制動器的壓力。當(dāng)壓力釋放時,它會釋放到液壓單元。前部的制動器電路有一個單元。存儲器低壓存儲器,它在低壓下存儲油液,直到回流泵打開,油液流經(jīng)制動輪缸進(jìn)入制動主缸。
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