碰撞式核桃破殼機的設計,碰撞式核桃破殼機的設計,碰撞,核桃,破殼機,設計 Manuf智力J備有工藝(2005):551-559 25.10.1007 / s00170-003-1843-3 Masood?b?阿巴斯懸Shayan?a?e卡拉調(diào)查設計和制造機械輸送系統(tǒng)，有食品加工。 2003年3月29日收到:2003年6月21日/接受:6月23日/發(fā)表在線:2004年，斯普林格出版社倫敦有限ó2004年 摘要：本文章介紹了開發(fā)方法和技術(shù)進行將降低成本和時間的設計、制造和裝配的機械輸送系統(tǒng)的研究的結(jié)果，應用于食品和食品飲料行業(yè)。改進后的方法來設計和生產(chǎn)的自動調(diào)節(jié)式氣力輸送的組件是基于新的材料、零件、成本、使用規(guī)則的設計制造和面向裝配的設計。結(jié)果在一個測試輸送系統(tǒng)驗證的好處——通過采用改進的技術(shù)。整體材料成本和傳統(tǒng)的方法相比降低了19%，整體裝配成本相比,降低了20%。 關(guān)鍵字：裝配.DFA?DFM.設計，機械輸送。 1介紹 輸送系統(tǒng)應用于食品和飲料行業(yè)高度自動化的定制結(jié)構(gòu)組成的一個大型零件的數(shù)量和用來攜帶產(chǎn)品,如食物紙箱裝,喝的瓶子和罐子在快速生產(chǎn)和組裝線。大部分的處理和包裝的食品和飲料-在紙箱、持續(xù)經(jīng)營再保險——瓶或罐等。在一個被控制quired移動速度,對充填或者裝配墨粉壽命結(jié)束- 成為。他們的操作需要高效、可靠的我-傳送帶運輸,操作時,范圍從高架地板-類型的安裝類型的連鎖店,或者帶式輸送機滾筒驅(qū)動系統(tǒng)。近年來,極大的壓力來自客戶低成本但高效的機械輸送系統(tǒng)使得制造商重新檢查他們的當前的設計和組裝等看看另一種方法和手段來制造更多經(jīng)濟、可靠的輸送帶,為他們的客戶帶來方便，目前,懸Masood(u)?b?a?e Shayan阿巴斯卡拉工業(yè)研究所一本史文朋, 一本史文朋理工大學,墨爾本,澳大利亞3122山楂, 電子郵件：smasood@swin.edu.au: 改進后的新零件大多數(shù)物料搬運設備,硬件和軟件兩個方面,都是高度專業(yè)化,呆板的和昂貴的配置、安裝維持[1]。輸送帶,被固定在以他們的位置和根據(jù)他們的同步輸送帶速度,任何轉(zhuǎn)換的輸送系統(tǒng)非常困難和前期陷入沉思。在今天的從根本上改變工業(yè)市場,有一個需要執(zhí)行一種新的制造策略,一個新的系統(tǒng)經(jīng)營理念,并提出了一種新的系統(tǒng)控制軟件和硬-陶瓷的發(fā)展理念,可應用于設計的新一代的開放、靈活物料搬運系統(tǒng)[2]。何鴻燊和Ranky[3]模型,提出了一種新的模塊化可重構(gòu)二維和三維的輸送系統(tǒng),包括一個開放的稀土-可配置的軟件體系結(jié)構(gòu)的基礎(chǔ)上,CIM-OSA(打開 系統(tǒng)架構(gòu))模型。指出研究地區(qū)輸送系統(tǒng)的改進、完善和提高,用于飲料-焦化是非常有限的。大部分的發(fā)表的研究論文是指揮 用于改善輸送系統(tǒng)的操作和交互的系統(tǒng)非常復雜的軟件和硬件。本文提出一種研究調(diào)查，實踐證明,使用當前技術(shù)標志、制造和裝配型鏈式的地板上 驅(qū)動機械輸送設備,以減少制造這樣的運輸機的時間和成本。應用了并行工程的設計和實施的基本原則 面向裝配的設計制造和[4、5],幾個關(guān)鍵研究了輸送機零部件都是為他們的功能、材料適宜性、強度準則、成本和簡化了安裝的 整體輸送系統(tǒng)。這個關(guān)鍵零部件進行了改性用新的形狀和幾何位置重新設計,以及一些新材料。改進后的設計方法和功能 驗證了新型平零件上測試了一種新測試,系統(tǒng)設計、制造和組裝過程中使用。 設計制造和裝配DFMA) 近年來,研究在該地區(qū)的可制造性設計和裝配已成為非常有用,因為他們正在考慮提高工業(yè)設施和生產(chǎn)。然而,沒有足夠的工作完成后,在該地區(qū)輸送機的設計,特別是相關(guān)的組件是使得越來越多的圖紙數(shù)據(jù)與重組。輸送過程的設計基于傳統(tǒng)的方法。 大量的文章發(fā)表,investi -DFMA封閉的相關(guān)問題,并將其應用于各種methodolo -要達成目標,使經(jīng)濟、高效和成本證明 有效的對這些公司正在調(diào)查之中。 主要的分類知識就可以影響DFMA - 問題的一般準則為(1)、(2)特定公司的最佳 (3)進行resource-specific過程和或約束。一般指通常適用rules-of-thumb指南,到制造領(lǐng)域的設計師應該注意。下面的列表整理了DFM指南[6]。 ?設計最小數(shù)目的部分 ?開發(fā)一種模塊化設計 ?最小化部分變化 多功能?設計部件 multiuse?設計零件 為便于設計部分的0.9%的制造 ?避免單獨緊固件 靈活性:?最大化設計為便于裝配 處理:設計?最小化處理的簡報 ?評估的裝配方法 ?消除調(diào)整 避免靈活的組件?:他們很難對付 ?使用零件已知的能力 偏執(zhí)?允許的最高部分 使用已知的和證明?零售商和供應商 在derated?使用零件析出大量的價值觀與沒有邊際 ?最小化組件 ?強調(diào)標準化 ?使用盡可能簡單的操作 使用已知的能力?操作 啟動和干預措施。?最小化 承接的工程更改?批量生產(chǎn) 這些設計指導方針應該被認為是“最優(yōu)的建議”。他們通常會導致高質(zhì)量、低-成本,地設計。偶爾的妥協(xié)必須被做,當然。在這些情況下,如果一個指導方針,走過去了對市場營銷或性能要求,下一個最好的選擇應選擇[7]。 它是指特定公司的最佳實踐的內(nèi)部設計公司開發(fā)的條例,通常是在很長一段時間,和設計師是沿襲。這些設計規(guī)則是確定的公司等導致質(zhì)量得以改善嗎通過識別和效率的總體關(guān)系特定的過程和設計決策。公司使用這樣的培訓指導方針的一部分給設計師的產(chǎn)品需要大量的手工裝配或-維護。值得注意的是,大部分的方法論擅長任選一種被快速和容易的開始,或者是被更正式的。例如,指導方針,布斯羅伊德Dewhurst[8],在DFA被視為定量和系統(tǒng)的。 而DFM指導方針,這僅僅是法則經(jīng)驗豐富的專業(yè)人員,是源自于一些定性和不那么正式的[9]。 3．傳統(tǒng)的輸送系統(tǒng)的設計 輸送系統(tǒng)的設計和制造是一個非常復雜和費時的過程。像每個輸送系統(tǒng)一個定做的產(chǎn)品,每個項目不同于其他的項目在規(guī)模、產(chǎn)品和布局。該系統(tǒng)設計是基于客戶需求,產(chǎn)品的規(guī)格要求。該系統(tǒng)布局必須適合在空間所提供的公司。這個過程的設計規(guī)劃系統(tǒng)-輸送機瞬變電磁法(tem)涉及修改以及可能要花上數(shù)天到數(shù)月不等或某些情況下十年。一個以最低的成本和最大。 最有可能的客戶適用性得到認可。圖1顯示一個圖解的布局對一典型輸送機系統(tǒng)安裝在生產(chǎn)線用于標簽塑料瓶。輸送機系統(tǒng)的不同地區(qū)特殊的技術(shù)鑒定的名字,一般運用于類似的工業(yè)應用。美國證券交易委員會(sec)的“singlizer”-使產(chǎn)品的聲譽形成一條車道從多個車道。“經(jīng)濟放緩的速度表“降低產(chǎn)品一旦它的出口,labeller填料等。美國證券交易委員會(sec)的“大規(guī)模流動”-興是用來跟上高速過程,例如,填料,labeller等?！稗D(zhuǎn)會表”的方向發(fā)展,促進轉(zhuǎn)移-流動。這些不同的目的是輸送機部分因此為了控制產(chǎn)品,通過不同的處理流程。一個典型的機械輸送系統(tǒng)用于食品應用包括了兩百機械根據(jù)大小電器部件的系統(tǒng)。一些常見的但又極為重要的組件,可能是標準和積累了家族的輸送系統(tǒng)。側(cè)架、間隔臂的酒吧,最后板、覆蓋板、內(nèi)彎板、外板、彎曲的軌道和井(開車,尾巴和奴隸)。大小和數(shù)量的變化來表明自己的這些部分的長度的自動調(diào)節(jié)式氣力輸送的對應部分的內(nèi)容和數(shù)量的軌跡-ing的寬度和類型的鏈所要求的。存在的問題及在當前的設計缺陷、制造和裝配機械輸送設備多樣化、包括: ?在設計對部分 ?高成本的一些組件 ?長時間參與總裝/維修 ?使用非標零件 圖1 4．部分的改進 為了識別領(lǐng)域的材料、降低成本勞動的成本分析的主要輸送部件進行了研究估計成本的百分比各部分的關(guān)系所有這類零件的總成本。這個分析的目的是為了識別關(guān)鍵零部件,主要負責在-壓痕的成本,從而探討輸送方式對于降低成本的部分。 表1顯示了一個50-section輸送機的成本分析系統(tǒng)-瞬變電磁法(tem)。通過分析可知,有12個零件組成的15達79%總材料成本的輸送系統(tǒng),在那里的進一步研究的重點改進設計,降低成本是可能的。從這些,七個部分,分別鑒定為關(guān)鍵的部位(顯示的 星號符號在表1)構(gòu)成最大數(shù)量的成分-達71%的數(shù)量,并包括在整體上的資料成本。在這些人之中,三種成分(腿套,側(cè)架和支持渠道)被發(fā)現(xiàn)占總數(shù)的50%輸送機材料成本。詳細分析了每一種12考慮到零件的原則進行并行en -工程、設計制造和面向裝配的設計,和研制了一種新的改進設計,每宗[10]。德-改進設計的尾巴的一些選定的主要部件 5.腿套附件的重新設計 在一個輸送系統(tǒng),腿是安裝在側(cè)架保持整個輸送系統(tǒng)在了地板上。現(xiàn)有的設計工作的自動調(diào)節(jié)式氣力輸送的腿,但是花費也很昂貴的制造、他們有穩(wěn)定的問題,并會造成延誤發(fā)貨。延遲 通常是造成這些部分不到位從超過- 供應商準時。最關(guān)鍵的規(guī)格要求為輸送機是: 帶式輸送機?強度負荷 ?穩(wěn)定性 ?簡化了安裝 安逸的靈活性(?調(diào)整高)。 圖2顯示的所有部件的使用現(xiàn)有的設計輸送機的腿。指定的密碼是零件編號表2中所描述的,體現(xiàn)了一種——的一個故障成本。 完整的勞動時間要求組裝系統(tǒng)性的腿?，F(xiàn)有的腿設置由塑料腿括號內(nèi)的命令來自海外,不銹鋼管,腿 切成指定的尺寸,腿管子塑料的調(diào)整,是哪一種管夾到腿是在底部,如圖2。凸耳,切成大小、鉆孔、焊接而成廣場到腿 管螺栓角度拉條和背襯板,以支持腿支架螺栓。#各部分的表2意味著這個號碼在每個部分元件的數(shù)量和質(zhì)量是特殊的。 腿各部分的設計。公司利用這個設計為許多年,但一個常見的投訴。據(jù)報導,客戶是不穩(wěn)定的腳。從最初的調(diào)查,就變得很明顯就是不銹鋼管的聲譽之間和塑料腿支架(部分 在圖1和第3部分。2)沒有剛性足夠了。連接這些零件是唯一一個6毫米螺栓。有時,當輸送系統(tǒng)正載著滿載荷、觀察發(fā)現(xiàn)產(chǎn)品 輸送機的腿是不穩(wěn)定的,并引起了機械震動。其中最主要的原因是由于一個單一的螺栓連接兩端的凸耳在第三部分和部分的——輸送機可靠性具有重要物質(zhì)和要求。 為了滿足顧客的期望立即改正?？紤]到存在的問題——輸送機腿德標志和客戶的喜好,一個新設計的輸送機腿被發(fā)展。一般的強度和穩(wěn)定性腿被認為是主要的標準。 在新的設計方案的觀點,但其他的考慮簡單的計,海外部分的安逸裝配環(huán)節(jié)的調(diào)試。圖3顯示,新設計的輸送機的腿總成,和表3給出了描述和造價的每一部分。 圖3顯示,新設計僅由五個主要的各部位為輸送機的腿比八種主要的部件舊的設計。在舊的設計、塑料腿支架,腿塑料調(diào)節(jié)和腿管子管是最貴的項目成本核算的72%的腿總成。 表1。輸送機關(guān)鍵零部件,基于部件成本分析 產(chǎn)品說明 腿*設置 *側(cè)架 支持渠道* 彎曲軌跡 *Rt.滾子軸 尾軸 間隔條* 支持*穿帶 支持一端穿條* 終板 蓋板 彎板 轉(zhuǎn)矩臂支架 槽蓋 彎板內(nèi) 總 關(guān)鍵零部件 數(shù)量 68 80 400 8 139 39 135 400 132 39 39 8 18 97 8 材料應用 塑料腿+ SS管 2 5.m m SS C 信道SS 塑料 20直徑的S軸 35直徑不銹鋼 50X50X6 SS 40×10毫米塑料 塑料 2 5.m m / SS 1 6.m m S / S 2 5.m m / SS 6毫米的飛船空間站板 不銹鋼2 5.m m / SS 花費(%) 20.22 16.07 15.00 14.36 6.70 6.27 5.43 5.36 3.01 1.88 1.57 1.29 1.21 0.97 0.66 100.00 改進的可能 是的 是的 是的 沒有 是的 沒有 是的 是的 是的 是的 沒有 是的 是的 是的 是的 是的 *表2。成本分析對老腿設計組裝 部分描述。 1 塑料腿支架 5 腿管子塑料調(diào)整 6 凸 4 角度拉條 7 背襯板 2 腿管 3 螺栓 8 總裝配成本(焊接) 圖2 圖3 表3。成本分析對新設計的腿總成 （部分描述） 1 不銹鋼角(50×50×3毫米) 3 腿塑料調(diào)整 4 交叉brassing 5 螺栓 2 背襯板 結(jié)果,那些部分都已經(jīng)被一種不銹鋼角的影響并提出了一種新的塑料腿調(diào)整降低生產(chǎn)成本的腿assem -bly由接近50%。因此零件的總數(shù)量的腿從19日已減少到15和總成本為每回合的設置 減少了55美元的新設計。新輸送機腿設計、測試時,被發(fā)現(xiàn) 更為安全、穩(wěn)定的比舊的設計。消除零件號1個月和5從老式輸送機設計作出了新的設計更加穩(wěn)定和剛性的。此外,寬度,釘在十字架上支撐也有提高,而不是兩個螺栓的山一個在舊的設計。這樣就提供了整個輸送機腿的設置額外的力量。 6側(cè)架的重塑 邊框架是首要支持輸送系統(tǒng)提供體力輸送機及幾乎所有的 零件安裝在它。側(cè)架的預計也會有一個剛性的力量來提供必要的支持給所有的荷載進行了輸送機。它也可適應所有相關(guān)的輸送機 組件的裝配。關(guān)鍵的考慮的一面框架設計是: 側(cè)架的大小(?深度) ?強度的材料 ?易于裝配 ?易于制造 圖4顯示了側(cè)架尺寸和參數(shù)。 側(cè)架的使用,在現(xiàn)有的設計深度尺寸(尺寸H在圖4)調(diào)查時,發(fā)現(xiàn)之間的距離間隔的酒吧，軸(孔尺寸和回報G和F,如圖4)降低的時候,就像有了一些不必要的兩個人之間的距離。更為重要的一點,定義之前先檢查一下設計參數(shù),以確保帶來另外兩份關(guān)系更加密切,返回鏈不會趕上間隔條而輸送機在運行。該模型的新球隊的框架設計畫在計算機輔助設計(CAD),以確保所有的規(guī)格是聲音部分是放置在位置和檢查的間隙很適合。通過這一原則的可制造性設計的新球隊的框架設計是對稱的,以便它適用于所有類型 側(cè)架的。這個變化將減小尺寸的一邊所有通徑的框架顯著鏈。 表4顯示的維度上的比較舊的設計和新設計的側(cè)架為同一鏈類型。 圖4 表4。新的和舊的側(cè)架尺寸參數(shù) 它指出整體規(guī)模(深度)的輸送機有什么期望減少241 mm 199毫米(尺寸H),節(jié)約了42毫米不銹鋼在每側(cè)架馬努-factured。因此,從一個不銹鋼薄板×毫米,1500 3000股老設計參數(shù)只允許六3米長的側(cè)架但隨著新的設計參數(shù),現(xiàn)在它是可能的生產(chǎn)7側(cè)架3米長從同樣的表大小。用于的資料數(shù)量也是再保險——側(cè)架認為為更深入的研究。據(jù)估計,約55%總成本的輸送系統(tǒng)都花在材料。 目前的資料用于側(cè)架是2.5毫米厚污點-304鋼的等級食物少。目前,還有其他的材料市場上可以買到的厚度,可以選擇作為一個選項。為此,一位撓度分析進行了預測,如果有任何其他類型的資料西裝能夠取代現(xiàn)有的資料,這樣它才不會沒有通過它的 強度標準。分析6.1撓度側(cè)架圖5給出了確定的實驗系統(tǒng)實踐新球隊的框架下,在X,Y方向不同加載條件。隨著新的設計參數(shù)的一組側(cè)架的生產(chǎn)調(diào)查撓度等1 6.m米厚的不銹鋼側(cè)架。一段側(cè)架螺栓與間隔條和回歸測試-軸是組裝做這個實驗。獲得的結(jié)果撓度運用可變荷載側(cè)架的一個區(qū)段通過一個液壓。顯示在圖5,撓度表 放置在垂直(Y)和橫向(X)軸來測量嗎任何閱讀上觀察到的側(cè)架。應用的負荷是通過對側(cè)架的液壓機向下方向。 側(cè)架的支持上從同樣的位置那里的腿是安裝在側(cè)架。 8的軌跡輸送機路段觀察任何異常在大負載。負載的應用于實驗輸送機部分在估算和高于實際負荷欺詐-在真正輸送機系統(tǒng)條件應用。輸送設備的通常用來攜帶下的荷載一公噸,每米 工業(yè)應用于食品和飲料行業(yè)。掣普珥-應用大量的輪廓點是估計偏轉(zhuǎn)對側(cè)架在高負載下。數(shù)字6和7取得成果的 通過實驗對輸送機的四個進程和部分六軌,分別。 從獲得的結(jié)果,觀察2 KN下?lián)隙戎档暮奢d作用下,幾乎是在2毫米 圖5 圖6 圖7 類型的部分。在一定情況下,1.6毫米不銹鋼側(cè)架的設計,可以一種可能的選擇在現(xiàn)有的輸送機側(cè)架的設計。據(jù)預計,有更大的部分,對輸送帶撓度的側(cè)架的意志呆在允許范圍內(nèi),也就是說,±5毫米。主要的是為什么這個試驗是確保側(cè)架裂紋不扣在高負載下。因此沒有 對于任何證據(jù)屈曲發(fā)生的各種類型的部分使用。但預計也,經(jīng)驗教訓的基礎(chǔ)上工程師和調(diào)查研究,在當前完整的總成后,輸送設備想像的力量,這將進一步額外減少可靠性偏斜對側(cè)架。例如,撓度,對于每一套測量實驗的意義。與安裝在側(cè)架腿,部隊將行為相反的方向,將極大推動側(cè)架里面。完整的觀察可見特發(fā)性肺纖維化-保護的這個假設當一個完整可以得出結(jié)論 輸送機是內(nèi)制造和測試試驗的基礎(chǔ)上的新設計參數(shù)。 所有的實驗結(jié)果,得到了令人滿意的結(jié)果,它是騙人的-那1.6毫米不銹鋼304側(cè)架品位是專為輸送帶,對于食物和飲料行業(yè) 指定的指導方針下負載。制造的成本節(jié)約這個地區(qū)有顯著的自預計80%的材料的用量在一個輸送系統(tǒng)是不銹鋼做的。 6.2側(cè)架成本分析 物料檢討和撓度的分析表明了現(xiàn)有2.5毫米不銹鋼薄板設計是一個在身邊的時候我是誰框架的食品和飲料輸送機應用。alysis也顯示,1.6毫米厚的不銹鋼薄板即可作為一種替代性材料為側(cè)架,這將履行令人滿意。表5顯示一個比較成本的舊的,新設計的側(cè)架,哪個 表明,節(jié)約每側(cè)架在新設計是37億美元(例如:一個儲蓄的50.1%)。除此之外,節(jié)約成本,減少側(cè)架從尺寸241 mm 199 mm也將允許生產(chǎn)一個額外側(cè)架的3000×1500毫米不銹鋼。 在圖紙上。新設計的改善是開展了好幾個其他關(guān)鍵的部位,如支持渠道,還滾子軸上,穿條間隔的酒吧,支持和支持,一端穿帶 導致更多的成本和勞動的儲蓄和緩解肌肉吉諾比利-成和組裝等。例如,新的設計的支持總成(包括支持渠道穿帶和一端穿條)要求降低若干進程,減少磨損的紙條厚度、使用一個新的M截面通道和規(guī)定使用不同種類的鏈給人們提供了一種節(jié)約成本的33.7%實驗結(jié)果表明,改進的設計。這種新設計的輥軸的回報-用一種節(jié)約成本和減少50% 44.5%的勞動力時間。這種新設計間隔酒吧提供費用估計從節(jié)省25%的舊的設計。 7 一個在測試設計實施的輸送系統(tǒng) 設計改進的實施零件和部件進行設計,圖靈測試和組裝的一個較為完整的輸送系統(tǒng)。這新的和改進的測試和驗證輸送機當時性能與實際產(chǎn)品(塑膠瓶)。分析了成本——還進行了比較sis是整體成本的儲蓄,在這個測試輸送機與所涉及的費用與一個相同的輸送機 基于陳舊的設計[7]。新的考試輸送機是一種類型(圖8),共有三個不同的部分的總長度5米。部分six-track C1是一段截面C2輸送機,加入是一個six-track彎曲90?輸送機。這是連接到輸送機補體C3,它是一段eight-track輸送機的部分,稱為雜合- 國家的兩種不同類型的枷鎖,標簽和力量。測試輸送含有共有26主要部分。圖9所示的是用于測試的測試輸送機在合作產(chǎn)品開發(fā)流程 公司。性能和效率的新測試方法的輸送機和它的重要的新零件進行了光滑、無噪音的表演-通過觀察極佳的產(chǎn)品開發(fā)流程的空的塑膠喝瓶輸送鏈條。所有的器官和輸送系統(tǒng)發(fā)現(xiàn)良好的靜動態(tài)性能充分展示功能。一個完整的成本分析在測試輸送機進行了研究 為了衡量不同新與舊的設計也在組裝評價緩解和減少勞動expendi -真正的。部件數(shù)量,所用的原材料、生產(chǎn)成本進行了計算和百分比等各個部分的存款每一部分和整體系統(tǒng)進行測定。 圖8 圖9 8結(jié)果和討論 最關(guān)鍵的面積來查看是否考慮是新的支持通道的設置和滴盤中加入已經(jīng)執(zhí)行用較少的勞動消耗。注意的是,也已經(jīng)向 確保勞動者已經(jīng)工作有效地工作。 《紐約時報》用于組裝的輸送系統(tǒng)是在意料之中的對取決于心情的工人和其他外部前沿空中管制官-工具。但是努力達到盡可能密切的時間制造的輸送設備。一項研究揭示了證明成本分析的事實:生產(chǎn)成本節(jié)約?40%或更多達到了 八改良設計部分節(jié)約成本實現(xiàn)了26%,34%在其他三個部分組成。 ?在高成本部分,最大的儲蓄為實現(xiàn)軸側(cè)架,還輥,腿集和支持穿條紋的。 ?的總費用降低了19%的輸送機。 ?整體勞動力成本在裝配的輸送機降低了20%。 研究表明,該儲蓄完成主要輸送機的零件,達到或超過設計 不是設計專業(yè)。其中最主要的變化,這些變化輸送機系統(tǒng)的影響是設計的修訂側(cè)架的設計參數(shù),這也會影響到這些變化在其他地方,都是同盟。其次,發(fā)展支持新的M剖面的通道隨著標準磨損 條添加到巨大的成就在新的輸送機的設計。完成從全新的設計減少了勞動也做出了重大影響成本和流水線上提高了產(chǎn)品設計和制造。同時也注意到,它是由categorising間隔棒不同數(shù)量的軌跡im - 證明了選拔程序的設計。新輸送機制度已成為更經(jīng)濟且有效的成本和需求使用額外的增強材料被淘汰出局。 9結(jié)論 在設計和制造機械輸送系統(tǒng)-等方面,有相當不足的研究工作的輸送機設計優(yōu)化,特別是缺乏應用技術(shù)來設計改進在這樣的系統(tǒng)。在為了提高成本和訂貨至交貨的時間——在輸送系統(tǒng) 瞬變電磁法(tem)、一個完整的故障分析,這也是一種試輸送機等久了進行評估的高消費地區(qū)于輸送機馬努-成。分析運用原則的支持 可制造性設計,為提高面向裝配的設計在不犧牲的功能設計和運行的系統(tǒng)。一種新的式輸送機設計提出了一種基于所有 建議的修改的自動調(diào)節(jié)式氣力輸送的組件。該建議驗證了輸送系統(tǒng)以及在考試的時候所采用的合作公司。結(jié)果證明見sub - cessful與整體的儲蓄,在成本和19%下降20%總勞動成本。研究結(jié)果顯示,應用DFMA的規(guī)則,設計和組裝的費用的一個情結(jié) 像機械輸送系統(tǒng)為食品加工即可戲劇性的減少。 參考 1. Anderasen MM, Ahm T (1986) Flexible assembly system. Springer, Berlin Heidelberg New York 2. Ho JKL, Ranky PG (1994) The design and operation control of a recon- figurable ?exible material handling. Proceedings of 1994 Japan-USA Symposium of Flexible Automation, vol. 2, Kobe, Japan, pp 825-828 3. Ho JKL, Ranky PG (1997) Object oriented modelling and design of reconfigurable conveyors in ?exible assembly systems. Int J Comput Integr Manuf 10(5):360-379 4. Kusiak A (1990) Intelligent manufacturing systems. Prentice Hall, New York 5. Corbett J, Dooner M, Meleka J, Pym C (1991) Design for manufactur- ing: strategies principles and techniques. Addison-Wesley, UK 6. Mize JH, Glenn P (1989) Some fundamentals of integrated manufac- turing. International Industrial Engineering Conference Proceedings, Washington, DC, pp 546-551 7. Mize JH (1987) CIM-a perspective for the future of IE's. IIE Integrated Systems Conference Proceedings, Nashville, TN, pp 3-5 8. Boothroyd G, Dewhurst P (1988) Product design for manufacturing and assembly. Manuf Eng April:42-46 9. Bedworth DD, Henderson MR, Wolfe PM (1991) Computer integrated design and manufacturing. McGraw-Hill, Singapore 10. Abbas B (2001) An investigation into design and manufacturing of mechanical systems for food processing and beverage industry. Disser- tation, Swinburne University of Technology, Hawthorn, Australia DOI 10.1007/s00170-003-1843-3 ORIGINAL ARTICLE Int J Adv Manuf Technol (2005) 25: 551559 S.H. Masood B. Abbas E. Shayan A. Kara An investigation into design and manufacturing of mechanical conveyors systems for food processing Received: 29 March 2003 / Accepted: 21 June 2003 / Published online: 23 June 2004 Springer-Verlag London Limited 2004 Abstract This paper presents the results of a research investi- gation undertaken to develop methodologies and techniques that will reduce the cost and time of the design, manufacturing and assembly of mechanical conveyor systems used in the food and beverage industry. The improved methodology for design and production of conveyor components is based on the minimisa- tion of materials, parts and costs, using the rules of design for manufacture and design for assembly. Results obtained on a test conveyor system verify the benefits of using the improved tech- niques. The overall material cost was reduced by 19% and the overall assembly cost was reduced by 20% compared to conven- tional methods. Keywords Assembly Cost reduction Design DFA DFM Mechanical conveyor 1 Introduction Conveyor systems used in the food and beverage industry are highly automated custom made structures consisting of a large number of parts and designed to carry products such as food cartons, drink bottles and cans in fast production and assembly lines. Most of the processing and packaging of food and drink in- volve continuous operations where cartons, bottles or cans are re- quired to move at a controlled speed for filling or assembly oper- ations. Their operations require highly efficient and reliable me- chanical conveyors, which range from overhead types to floor- mounted types of chain, roller or belt driven conveyor systems. In recent years, immense pressure from clients for low cost but efficient mechanical conveyor systems has pushed con- veyor manufacturers to review their current design and assembly methods and look at an alternative means to manufacture more economical and reliable conveyors for their clients. At present, S.H. Masood (a117) B. Abbas E. Shayan A. Kara Industrial Research Institute Swinburne, Swinburne University of Technology, Hawthorn, Melbourne 3122, Australia E-mail: smasoodswin.edu.au most material handling devices, both hardware and software, are highly specialised, inflexible and costly to configure, install and maintain 1. Conveyors are fixed in terms of their locations and the conveyor belts according to their synchronised speeds, mak- ing any changeover of the conveyor system very difficult and ex- pensive. In todays radically changing industrial markets, there is a need to implement a new manufacturing strategy, a new system operational concept and a new system control software and hard- ware development concept, that can be applied to the design of a new generation of open, flexible material handling systems 2. Ho and Ranky 3 proposed a new modular and reconfigurable 2D and 3D conveyor system, which encompasses an open re- configurable software architecture based on the CIM-OSA (open system architecture) model. It is noted that the research in the area of improvement of conveyor systems used in beverage in- dustry is very limited. Most of the published research is directed towards improving the operations of conveyor systems and inte- gration of system to highly sophisticated software and hardware. This paper presents a research investigation aimed at im- proving the current techniques and practices used in the de- sign, manufacturing and assembly of floor mounted type chain driven mechanical conveyors in order to reduce the manufactur- ing lead time and cost for such conveyors. Applying the con- cept of concurrent engineering and the principles of design for manufacturing and design for assembly 4, 5, several critical conveyor parts were investigated for their functionality, material suitability, strength criterion, cost and ease of assembly in the overall conveyor system. The critical parts were modified and redesigned with new shape and geometry, and some with new materials. The improved design methods and the functionality of new conveyor parts were verified and tested on a new test con- veyor system designed, manufactured and assembled using the new improved parts. 2 Design for manufacturing and assembly (DFMA) In recent years, research in the area of design for manufacturing and assembly has become very useful for industries that are con- 552 sidering improving their facilities and manufacturing methodol- ogy. However, there has not been enough work done in the area of design for conveyor components, especially related to the is- sue of increasing numbers of drawing data and re-engineering of the process of conveyor design based on traditional methods. A vast amount of papers have been published that have investi- gated issues related to DFMA and applied to various methodolo- gies to achieve results that proved economical, efficient and cost effective for the companies under investigation. The main classifications of DFMA knowledge can be iden- tified as (1) General guidelines, (2) Company-specific best prac- tice or (3) Process and or resource-specific constraints. General guidelines refer to generally applicable rules-of-thumb, relat- ing to a manufacturing domain of which the designer should be aware. The following list has been compiled for DFM guidelines 6. Design for a minimum number of parts Develop a modular design Minimise part variations Design parts to be multifunctional Design parts for multiuse Design parts for ease of fabrication Avoid separate fasteners Maximise compliance: design for ease of assembly Minimise handling: design for handling presentation Evaluate assembly methods Eliminate adjustments Avoid flexible components: they are difficult to handle Use parts of known capability Allow for maximum intolerance of parts Use known and proven vendors and suppliers Use parts at derated values with no marginal overstress Minimise subassemblies Fig.1. Layout of conveyor sys- tem for labelling plasic bottles Emphasise standardisation Use the simplest possible operations Use operations of known capability Minimise setups and interventions Undertake engineering changes in batches These design guidelines should be thought of as “optimal suggestions”. They typically will result in a high-quality, low- cost, and manufacturable design. Occasionally compromises must be made, of course. In these cases, if a guideline goes against a marketing or performance requirement, the next best alternative should be selected 7. Company-specific best practice refers to the in-house design rules a company develops, usually over a long period of time, and which the designer is expected to adhere to. These design rules are identified by the company as contributing to improved quality and efficiency by recognising the overall relationships between particular processes and design decisions. Companies use such guidelines as part of the training given to designers of products requiring significant amounts of manual assembly or mainte- nance. Note that most of the methodologies are good at either being quick and easy to start or being more formal and quanti- tative. For example, guidelines by Boothroyd and Dewhurst 8 on DFA are considered as being quantitative and systematic. Whereas the DFM guidelines, which are merely rules of thumb derived from experienced professionals, are more qualitative and less formal 9. 3 Conventional conveyor system design Design and manufacturing of conveyor systems is a very com- plex and time-consuming process. As every conveyor system is a custom-made product, each project varies from every other project in terms of size, product and layout. The system design 553 is based on client requirements and product specifications. More- over, the system layout has to fit in the space provided by the company. The process of designing a layout for a conveyor sys- tem involve revisions and could take from days to months or in some instances years. One with the minimum cost and maximum client suitability is most likely to get approval. Figure 1 shows a schematic layout of a typical conveyor system installed in a production line used for labelling of plastic bottles. Different sections of the conveyor system are identified by specific technical names, which are commonly used in similar industrial application. The “singlizer” sec- tion enables the product to form into one lane from multiple lanes. The “slowdown table” reduces the speed of product once it exits from filler, labeller, etc. The “mass flow” sec- tion is used to keep up with high-speed process, e.g., filler, labeller, etc. The “transfer table” transfers the direction of prod- uct flow. The purpose of these different conveyor sections is thus to control the product flow through different processing machines. A typical mechanical conveyor system used in food and bev- erage applications consists of over two hundred mechanical and electrical parts depending on the size of the system. Some of the common but essential components that could be standard- ised and accumulated into families of the conveyor system are side frames, spacer bars, end plates, cover plates, inside bend plates, outside bend plates, bend tracks and shafts (drive, tail and slave). The size and quantity of these parts vary according to the length of conveyor sections and number of tracks correspond- ing to the width and types of chains required. The problems and shortcomings in the current design, manufacturing and assembly of mechanical conveyors are varied, but include: Over design of some parts High cost of some components Long hours involved in assembly/maintenance Use of non-standard parts Table 1. Conveyor critical parts based on parts cost analysis Product description Qty Material used Cost (%) Improvement possible (Yes/No) Leg set 68 Plastic leg + SS tube 20.22 Yes Side frame 80 2.5 mm SS 16.07 Yes Support channel 400 C channel SS 15.00 Yes Bend tracks 8 Plastic 14.36 No Rt. roller shaft 139 20 dia. SS shaft 6.70 Yes Tail shaft 39 35 dia. Stainless steel 6.27 No Spacer bar 135 50X50X6 SS 5.43 Yes Support wear strip 400 40 10 mm plastic 5.36 Yes Support side wear strip 132 Plastic 3.01 Yes End plate 39 2.5mm/SS 1.88 Yes Cover plate 39 1.6 mm S/S 1.57 No Bend plates 8 2.5mm/SS 1.29 Yes Torque arm bracket 18 6 mm S/S plate 1.21 Yes Slot cover 97 Stainless steel 0.97 Yes Inside bend plate 8 2.5mm/SS 0.66 Yes Total 100.00 Critical parts 4 Areas of improvement In order to identify the areas of cost reduction in material and labour, a cost analysis of all main conveyor parts was conducted to estimate the percentage of cost of each part in relation to the total cost of all such parts. The purpose of this analysis was to identify the critical parts, which are mainly responsible for in- creasing the cost of the conveyor and thereby investigate means for reducing the cost of such parts. Table 1 shows the cost analysis of a 50-section conveyor sys- tem. The analysis reveals that 12 out of 15 parts constitute 79% of the total material cost of the conveyor system, where further improvements in design to reduce the cost is possible. Out of these, seven parts were identified as critical parts (shown by an asterisk in Table 1) constituting maximum number of compo- nents in quantity and comprising over 71% of overall material cost. Among these, three components (leg set, side frame and support channel) were found to account for 50% of the total conveyor material cost. A detailed analysis of each of these 12 parts was carried out considering the principles of concurrent en- gineering, design for manufacture and design for assembly, and a new improved design was developed for each case 10. De- tails of design improvement of some selected major component are presented below. 5 Redesign of leg set assembly In a conveyor system, the legs are mounted on the side frame to keep the entire conveyor system off the floor. The existing design of conveyor legs work, but they are costly to manufacture, they have stability problems, and cause delays in deliveries. The delay is usually caused by some of the parts not arriving from over- seas suppliers on time. The most critical specifications required for the conveyor legs are: 554 Strength to carry conveyor load Stability Ease of assembly Ease of flexibility (for adjusting height) Figure 2 indicates all the parts for the existing design of the conveyor leg. The indicated numbers are the part numbers described in Table 2, which also shows a breakdown of cost an- alysis complete with the labour time required to assemble a com- plete set of legs. The existing leg setup consists of plastic leg brackets ordered from overseas, stainless steel leg tubes, which are cut into specified sizes, leg tube plastic adjustments, which are clipped onto the leg tube at the bottom as shown in Fig. 2. Lugs, which are cut in square sizes, drilled and welded to the leg tube to bolt the angle cross bracing and backing plate to support leg brackets bolts. The # of parts in Table 2 signifies the number of components in each part number and the quantity is the con- sumption of each part in the leg design. Companies have used this design for many years but one of the common complaints reported by the clients was of the instability of legs. From an initial investigation, it became clear that the connec- tion between the stainless steel tube and plastic legs bracket (part Fig.2. Existing leg design assembly with part names shown in Table 1 Table 2. Cost analysis for old leg design assembly Part no. Part description # of parts Qty Cost Source 1 Plastic leg bracket 2 2 $ 30.00 Overseas 5, 6 Leg tube plastic adjustment 4 2 $ 28.00 Overseas 4 Lug 2 2 $ 4.00 In-house 7 Angle cross bracing 1 1 $ 5.00 In-house 2 Backing plate 2 2 $ 4.00 In-house 3 Leg tube 2 2 $ 25.00 In-house 8 Bolts 6 6 $ 3.00 In-house Total assembly cost (welding) $ 15.00 In-house Total 19 17 $ 114.00 1 and part 3 in Fig. 2) was not rigid enough. The connections for these parts are only a single 6 mm bolt. At times, when the conveyor system was carrying full product loads, it was observed that the conveyor legs were unstable and caused mechanical vi- bration. One of the main reasons for this was due to a single bolt connection at each end of the lugs in part 3 and part 7. The sta- bility of the conveyor is considered critical matter and requires rectification immediately to satisfy customer expectations. Considering the problems of the existing conveyor leg de- sign and the clients preferences, a new design for the conveyor leg was developed. Generally the stability and the strength of the legs were considered as the primary criteria for improve- ment in the new design proposal but other considerations were the simplicity of design, minimisation of overseas parts and ease of assembly at the point of commissioning. Figure 3 shows, the new design of the conveyors leg assembly, and Table 3 gives a description and the cost of each part. Figure 3 shows that the new design consists of only five main parts for the conveyors leg compared to eight main parts in the old design. In the old design, the plastic leg bracket, the leg tube plastic adjustment and the leg tube were the most expensive items accounting for 72% of the cost of leg assembly. In the new 555 Fig.3. New design for leg assembly with part names in Table 3 Table 3. Cost analysis for new design leg assembly Part no. Part description # of parts Qty Cost Source 1 Stainless steel angle (50503 mm) 2 2 $ 24.00 In-house 3 Leg plastic adjustment 2 2 $ 10.00 Overseas 4 Cross brassing 1 1 $ 7.00 In-house 5 Bolts 8 4 $ 4.00 In-house 2 Backing plate 2 2 $ 4.00 In-house Total assembly cost $ 10.00 In-house Total 15 11 $ 59.00 design, those parts have been replaced by a stainless steel angle and a new plastic leg adjustment reducing the cost of leg assem- bly by almost 50%. Thus the total numbers of parts in the leg have been reduced from 19 to 15 and the total cost per leg setup has been reduced by $ 55 in the new design. The new conveyor leg design, when tested, was found to be more secure and stable than the old design. The elimination of part number 1 and 5 from old conveyor design has made the new design more stable and rigid. In addition, the width of the cross bracing has also been increased with two bolts mount instead of one in old design. This has provided the entire conveyor leg setup an additional strength. 6 Redesign of the side frames The side frame is the primary support of a conveyor system that provides physical strength to conveyors and almost all the parts are mounted on it. The side frame is also expected to have a rigid strength to provide support to all the loads carried on the conveyor. It also accommodates all the associated conveyor components for the assembly. The critical considerations of side frame design are: Size of side frame (depth) Strength of the material Ease for assembly Ease for manufacturing Figure 4 shows the side frame dimension and parameters. The side frame used in existing design appears to be of rea- sonable depth in size (dimension H in Fig. 4). From the initial investigation, it was found that the distance between spacer bar holes and return shaft (dimensions G and F in Fig. 4) could be reduced, as there was some unnecessary gap between those two components. The important point to check before redefining the design parameters was to make sure that after bringing those two closer, the return chains would not catch the spacer bar while the conveyor is running. The model of the new side frame design was drawn on CAD to ensure all the specifications are sound and the parts are placed in the position to check the clearances and the fits. Using the principle of design for manufacturing the new side frame design was made symmetrical so that it applies to all types of side frames. This change is expected to reduce the size of side frame significantly for all sizes of chains. Table 4 shows a comparison of dimensions in the old design and the new design of side frames for the same chain type. It 556 Fig.4. Side frame dimensions Table 4. New and old side frame dimension parameters Old design Chain type A B C D E F G H I J K L 3.25 primeprime LF/SS STR/LBP/MAG 31 92 71 196 65 105 211 241 136 58 85 196 TAB 22 83 62 187 56 96 202 232 127 New design Chain type A B C D E F G H I J K L 3.25 primeprime LF/SS STR/LBP/MAG/TAB 31 100 73 173 67 107 167 199 92 58 85 152 is noted that the overall size (depth) of the conveyor has been reduced from 241 mm to 199 mm (dimension H), which gives a saving of 42 mm of stainless steel on every side frame manu- factured. Thus, from a stainless steel sheet 1500 3000 mm, the old design parameters allowed only six 3 m long side frames but with the new design parameter now it was possible to produce seven side frames of 3 m long from the same sheet size. The amount of material used for side frames was also re- viewed for further investigation. It is estimated that about 55% of the total cost of the conveyor system is spent on materials. The current material used for side frames is 2.5 mm thick stain- less steel food grade 304. Currently, there are other materials available in the market with alternative thickness that could be considered as an option. For this, a deflection analysis has been conducted to estimate if there was any other type of material suit- able to replace the existing material so that it does not fail its strength criteria. 6.1 Deflection analysis for side frames Figure 5 shows the experimental setup to determine the deflec- tion of new side frame in X and Y direction under different loading conditions. With the new design parameters a set of side frames were manufactured to investigate the deflection on 1.6 mm thick stainless steel side frames. A section of side frame bolted with spacer bar and return shaft was assembled for test- ing with the experiment. The