臥式數(shù)控加工中心回轉(zhuǎn)工作臺(tái)設(shè)計(jì)
喜歡這套資料就充值下載吧。資源目錄里展示的都可在線預(yù)覽哦。下載后都有，請(qǐng)放心下載，文件全都包含在內(nèi)，圖紙為CAD格式可編輯，有疑問(wèn)咨詢QQ:414951605 或 1304139763p
任務(wù)書
學(xué)院 專業(yè)
姓名 學(xué)號(hào)
設(shè)計(jì)題目： 臥式數(shù)控加工中心回轉(zhuǎn)工作臺(tái)設(shè)計(jì)
一、設(shè)計(jì)的內(nèi)容
隨著經(jīng)濟(jì)的不斷發(fā)展，客戶需求日益多樣化，對(duì)制造企業(yè)的生產(chǎn)模式提出了更高的要求，大批量的生產(chǎn)方式將逐漸被模塊化、柔性化的生產(chǎn)方式所取代。因此，企業(yè)對(duì)制造裝備提出了更高的要求，柔性化的數(shù)控加工設(shè)備將成為裝備制造業(yè)發(fā)展的主流。因此，將臥式數(shù)控加工中心的設(shè)計(jì)作為設(shè)計(jì)題目，迎合了裝備制造業(yè)發(fā)展趨勢(shì)。
臥式加工中心的回轉(zhuǎn)工作臺(tái)可以有效減少裝夾次數(shù)，提高加工中心的工序集中程度和加工效率。要求有較高的回轉(zhuǎn)定位精度。
二、設(shè)計(jì)的要求與數(shù)據(jù)
要求：收集加工中心設(shè)計(jì)資料，了解數(shù)控加工中心的工作原理，對(duì)典型立式數(shù)控加工中心的結(jié)構(gòu)進(jìn)行比較，提出本次設(shè)計(jì)的總體方案。了解加工中心進(jìn)給機(jī)構(gòu)的類型及工作原理，并對(duì)主軸箱部件進(jìn)行詳細(xì)設(shè)計(jì)。
設(shè)計(jì)參數(shù)如下：
加工中心的加工范圍為800×500×600，
主軸輸出功率10KW，
采用BT40標(biāo)準(zhǔn)刀柄。
三、設(shè)計(jì)應(yīng)完成的工作
1 設(shè)計(jì)說(shuō)明書1份（12000字）；
2 手工繪制圖、計(jì)算機(jī)打印圖紙若干張（折合A0圖紙3.0張以上）；其中，手工繪制圖或計(jì)算機(jī)打印圖紙不少于（折合A0圖一張）；
3 外文翻譯，漢字不少于5000字；
4 參考文獻(xiàn)：中文15篇，英文2篇。
四 設(shè)計(jì)進(jìn)程安排
序 號(hào)
設(shè)計(jì)各階段名稱
日 期
1
參考文獻(xiàn)查閱（綜述）、外文資料翻譯
寒假期間
2
畢業(yè)實(shí)習(xí)，資料收集
20XX.2.24-20XX.3.31
3
方案論證，繪制裝配圖
20XX.4.1-20XX.4.30
4
繪制零件圖
20XX.5.1-20XX.5.16
5
整理設(shè)計(jì)說(shuō)明書
20XX.5.17-20XX.6.4
五、參考資料及文獻(xiàn)查詢方向、范圍
1、 收集相關(guān)的機(jī)床設(shè)計(jì)資料，加工中心結(jié)構(gòu)、特別換刀機(jī)械手設(shè)計(jì)的資料。
2、 參考設(shè)計(jì)文獻(xiàn)有《機(jī)械制造裝備技術(shù)》、《數(shù)控機(jī)床》等。
3、 《機(jī)械設(shè)計(jì)手冊(cè)》。
設(shè)計(jì)開始日期 20XX年2月24 日 指導(dǎo)教師：
設(shè)計(jì)完成日期 20XX年6月 4 日 系 主 任：
院 長(zhǎng)：
20XX年2月24 日
題題 目目 臥式數(shù)控加工中心 回轉(zhuǎn)工作臺(tái)設(shè)計(jì) 學(xué)學(xué) 院院 專專 業(yè)業(yè) 班班 級(jí)級(jí) 學(xué)學(xué) 生生 學(xué)學(xué) 號(hào)號(hào) 指導(dǎo)教師指導(dǎo)教師 - I -摘 要 隨著無(wú)數(shù)科學(xué)家們努力的科學(xué)研究，科學(xué)技術(shù)在二十一世紀(jì)的今天可以說(shuō)是在日新月異的發(fā)生這變化。數(shù)控技術(shù)更是慢慢的登上了世界的舞臺(tái)，在制造業(yè)領(lǐng)域發(fā)揮了巨大的作用。而工作臺(tái)正是數(shù)控加工中心的一部分，隨著科學(xué)技術(shù)的不斷創(chuàng)新，數(shù)控回轉(zhuǎn)工作臺(tái)已經(jīng)得到普及。 本次設(shè)計(jì)的課題恰是數(shù)控回轉(zhuǎn)工作臺(tái)，經(jīng)過(guò)對(duì)該課題的設(shè)計(jì)，使我們靈活的運(yùn)用大學(xué)所學(xué)的知識(shí)，以及可以掌握一些機(jī)械設(shè)計(jì)的方法和步驟。該課題的主要內(nèi)容包括：確定設(shè)計(jì)方案、零件的設(shè)計(jì)計(jì)算與校核、繪制裝配圖和零件圖、寫設(shè)計(jì)說(shuō)明書。數(shù)控回轉(zhuǎn)工作臺(tái)實(shí)在普通工作臺(tái)的基礎(chǔ)上進(jìn)行改造的，在里面增加了渦輪蝸桿等傳動(dòng)機(jī)構(gòu)，使工作臺(tái)不僅能在 X、Y、Z 三個(gè)方向上進(jìn)行平面移動(dòng)，而且還能在繞著 Z軸做回轉(zhuǎn)運(yùn)動(dòng)，大提高了工作效率，節(jié)省了時(shí)間。8-10 關(guān)鍵詞：數(shù)控回轉(zhuǎn)工作臺(tái)；渦輪；蝸桿- II -ABSTRACTAlong with the science and research of countless scientists work, science and technology in twenty-first Century, today it can be said that this change change rapidly. Numerical control technology is more slowly on to the world stage, play a great role in the field of manufacturing industry. And the working table is part of a CNC machining center, with the continuous innovation of science and technology,NC rotary table has been popular.The graduation design topic is NC rotary table, through the design of the project,make us flexible use of university knowledge, and be able to grasp some of the methods and steps of mechanical design. The main contents of the paperinclude: to determine the design, parts design and checking, assembly drawing and parts, write design specification.Based on NC rotary table is really ordinary working table is modified, the worm and gear to increase on the inside, the table can not only move in a plane in X, Y,Z three directions, but also around the Z axis for rotary motion, greatly improves the work efficiency, saving time.Key words：NC rotary table；turbine；worm- III -目 錄摘要. .IABSTRACT.II1 前言.11.1 選題的背景和意義.1 1.1.1 國(guó)內(nèi)外現(xiàn)狀.1 1.1.2 選題的目的及意義.21.2 設(shè)計(jì)內(nèi)容.2 1.3 設(shè)計(jì)方案.22 數(shù)控回轉(zhuǎn)工作臺(tái)的設(shè)計(jì).52.1 電動(dòng)機(jī)的選擇及運(yùn)動(dòng)參數(shù)的計(jì)算.5 2.1.1 電動(dòng)機(jī)類型的選擇.5 2.1.2 電動(dòng)機(jī)功率的選擇.52.2 齒輪傳動(dòng)的設(shè)計(jì).62.2.1 選擇齒輪傳動(dòng)的類型和材料.62.2.2 按齒輪接觸疲勞強(qiáng)度設(shè)計(jì).62.2.3 按齒根彎曲強(qiáng)度設(shè)計(jì).82.2.4 幾何尺寸計(jì)算.92.3 渦輪及蝸桿的選用與校核.10 2.3.1 選用蝸桿傳動(dòng)類型.10 2.3.2 選擇材料.10 2.3.3 按齒面接觸疲勞強(qiáng)度進(jìn)行設(shè)計(jì).10 2.3.4 蝸桿與渦輪的主要參數(shù)與幾何尺寸.11 2.3.5 校核齒根彎曲疲勞強(qiáng)度.12 2.3.6 驗(yàn)算效率.122.4 軸的計(jì)算與校核.13 2.4.1 齒輪軸的設(shè)計(jì)與校核.13 2.4.2 蝸桿軸的設(shè)計(jì)與校核.172.5 軸承的計(jì)算與選用.21 2.5.1 軸承受到的載荷.22 2.5.2 驗(yàn)算軸承壽命.235 結(jié)論.24參考文獻(xiàn).25- IV -致謝.26- 1 -1 前言 二十一世紀(jì)的今天，社會(huì)在進(jìn)步，科技在創(chuàng)新，生產(chǎn)力水平也隨之快速發(fā)展。因而數(shù)控技術(shù)也隨之越來(lái)越廣泛的應(yīng)用于社會(huì)的各個(gè)領(lǐng)域。在數(shù)控技術(shù)上，數(shù)控機(jī)床的應(yīng)用最為普遍。而工作臺(tái)又是數(shù)控機(jī)床上必不可少的一部分，隨著科技的發(fā)展，科學(xué)家的研究，能夠?qū)崿F(xiàn)圓周進(jìn)給和分度運(yùn)動(dòng)的工作臺(tái)漸漸被使用于臥式的鏜床和數(shù)控加工中心上。數(shù)控回轉(zhuǎn)工作臺(tái)不僅提高了機(jī)床加工的工作效率，完成更多的加工工藝，主要的是它由伺服電機(jī)、齒輪、渦輪蝸桿以及工作臺(tái)等部分組成，里面還設(shè)計(jì)了鎖緊裝置，可以實(shí)現(xiàn)渦輪的加緊，所以說(shuō)數(shù)控回轉(zhuǎn)工作臺(tái)是一種很實(shí)用的加工工具，慢慢取代普通工作臺(tái)，已成為數(shù)控機(jī)床和數(shù)控加工中心上不可缺少的一部分。本次畢業(yè)課題的主要要求就是通過(guò)數(shù)控回轉(zhuǎn)工作臺(tái)的工作原理來(lái)進(jìn)行機(jī)械機(jī)構(gòu)的設(shè)計(jì)與各零部件的數(shù)據(jù)計(jì)算。設(shè)計(jì)思路是先原理后結(jié)構(gòu)，先整體后局部。811131.1 選題的背景和意義1.1.1. 國(guó)內(nèi)外現(xiàn)狀 目前，我國(guó)在數(shù)控機(jī)床行業(yè)飛速發(fā)展。其中，許多加工中心在加工精度上都已達(dá)到了一定的標(biāo)準(zhǔn)水平，可與許多發(fā)達(dá)國(guó)家的數(shù)控機(jī)床想媲美。而工作臺(tái)卻是機(jī)床上必不可少的一部分，隨著經(jīng)濟(jì)與科學(xué)技術(shù)的發(fā)展，數(shù)控回轉(zhuǎn)工作臺(tái)慢慢背普及，已經(jīng)被廣泛應(yīng)用于各種數(shù)控機(jī)床和和數(shù)控中心上。數(shù)控回轉(zhuǎn)工作臺(tái)是在普通工作臺(tái)的基礎(chǔ)上進(jìn)行改造的，但是由于我國(guó)機(jī)床附件廠的資金匱乏，造成了一些機(jī)床附件在技術(shù)創(chuàng)新和技術(shù)改造方面的力度不大，致使一些機(jī)床附件的發(fā)展水平停滯不前，成為了制約我國(guó)機(jī)床工業(yè)發(fā)展的瓶頸。12 然而，國(guó)外的數(shù)控機(jī)床已經(jīng)達(dá)到了很高的發(fā)展水平。能夠加工許多結(jié)構(gòu)復(fù)雜的零件，從而完成更多的工藝。9而數(shù)控回轉(zhuǎn)工作臺(tái)的應(yīng)用更是大大提高了數(shù)控機(jī)床或數(shù)控加工中心的工作效率，節(jié)省了更多的人力物力。1.1.2 選題目的及意義 隨著我國(guó)國(guó)民經(jīng)濟(jì)的迅速發(fā)展和國(guó)防建設(shè)的需要，對(duì)高檔數(shù)控機(jī)床提出了急迫的大需求。機(jī)床制造業(yè)是一國(guó)工業(yè)之基石，他為新技術(shù)、新產(chǎn)品的開發(fā)和現(xiàn)代工業(yè)生產(chǎn)提供重要的手段，是不可或缺的戰(zhàn)略性產(chǎn)業(yè)。即使是發(fā)達(dá)工業(yè)化國(guó)家，也無(wú)不高度重視。機(jī)床是一個(gè)國(guó)家制造業(yè)水平的象征。12 數(shù)控回轉(zhuǎn)工作臺(tái)不僅可以在 X、Y、Z 三個(gè)坐標(biāo)平面內(nèi)進(jìn)行水平移動(dòng)，還可以繞著 Z 軸做回轉(zhuǎn)運(yùn)動(dòng)，從而提高了機(jī)械加工效率，完成更多的加工工藝。數(shù)控回轉(zhuǎn)工- 2 -作臺(tái)有伺服電機(jī)帶動(dòng)，通過(guò)齒輪傳動(dòng)，渦輪蝸桿的傳動(dòng)，進(jìn)而帶動(dòng)工作臺(tái)做回轉(zhuǎn)運(yùn)動(dòng)10。1.2 設(shè)計(jì)內(nèi)容數(shù)控回轉(zhuǎn)工作臺(tái)是各種數(shù)控機(jī)床及數(shù)控加工中心的重要附件，它是由普通的工作臺(tái)改造而來(lái)，雖說(shuō)其外形與普通工作臺(tái)一樣，但它是由伺服系統(tǒng)進(jìn)行驅(qū)動(dòng)，再通過(guò)齒輪傳動(dòng)系統(tǒng)將動(dòng)力傳遞給渦輪蝸桿，再有渦輪帶動(dòng)工作臺(tái)轉(zhuǎn)動(dòng)。數(shù)控回轉(zhuǎn)工作臺(tái)的結(jié)構(gòu)：伺服電動(dòng)機(jī)、齒輪、渦輪蝸桿、工作臺(tái)等。數(shù)控回轉(zhuǎn)工作臺(tái)的功能；通過(guò)工作臺(tái)的繞 Z 軸的旋轉(zhuǎn)進(jìn)行加工一些形狀復(fù)雜的零件。1.3 設(shè)計(jì)方案 方案一：采用皮帶傳動(dòng)加渦輪蝸桿的傳動(dòng)方案。此方案缺點(diǎn)： 1. 滑動(dòng)損失：皮帶工作時(shí)，由于帶輪兩邊的拉力差以及相應(yīng)的變形經(jīng)差形成彈性滑動(dòng)，導(dǎo)致帶輪與從動(dòng)輪速度損失。打滑使運(yùn)動(dòng)處于不穩(wěn)定狀態(tài)，效率下降，摩擦加劇，影響皮帶壽命。1 2. 滯后損失：皮帶運(yùn)行時(shí)會(huì)產(chǎn)生反復(fù)伸縮，皮帶與帶輪的摩擦引起功率損失1。 3. 軸承的摩擦損失：皮帶工作時(shí)軸承受到皮帶的拉力，也引起轉(zhuǎn)矩。1圖 1.1 皮帶傳動(dòng)加渦輪蝸桿傳動(dòng)結(jié)構(gòu)簡(jiǎn)圖- 3 - 方案二：采用的是渦輪蝸桿加齒輪組的傳動(dòng)方案齒輪傳動(dòng)承載能力高，傳動(dòng)運(yùn)動(dòng)正確、平穩(wěn)，傳遞功率和圓周速度范圍很大，傳動(dòng)速率高，結(jié)構(gòu)緊湊。156 特點(diǎn)：1.尺寸小，結(jié)構(gòu)緊湊。 2.傳動(dòng)平穩(wěn)，噪聲低。 3.可以自鎖。 4.效率低、制造成本。圖 1.2 渦輪蝸桿加齒輪傳動(dòng)結(jié)構(gòu)簡(jiǎn)圖 方案三：采用的是齒輪傳動(dòng)和錐齒輪的傳動(dòng)方案 錐齒輪傳動(dòng)不具備自鎖功能。5- 4 -圖 1.3 齒輪和錐齒輪傳動(dòng)結(jié)構(gòu)簡(jiǎn)圖 設(shè)計(jì)中應(yīng)選最優(yōu)方案，故選擇方案二，其結(jié)構(gòu)圖如下：- 5 - 圖1.4 齒輪傳動(dòng)與渦輪蝸桿傳動(dòng)結(jié)構(gòu)圖2 數(shù)控回轉(zhuǎn)工作臺(tái)的設(shè)計(jì)2.1 電動(dòng)機(jī)的選擇及運(yùn)動(dòng)參數(shù)的計(jì)算在數(shù)控加工加工中心的許多機(jī)械加工都需要原動(dòng)力來(lái)進(jìn)行微量進(jìn)給，而要實(shí)現(xiàn)這些微量進(jìn)給的原動(dòng)力可以由步進(jìn)電機(jī)、直流伺服電機(jī)、或交流伺服電機(jī)這些可以作為驅(qū)動(dòng)元件來(lái)提供。22.1.1 電動(dòng)機(jī)類型的選擇- 6 -選擇電動(dòng)機(jī)的類型主要根據(jù)工作機(jī)械的工作載荷特性，有無(wú)沖擊，過(guò)載情況，調(diào)速范圍，起動(dòng)、制動(dòng)的頻繁程度以及電網(wǎng)供電狀況等。2對(duì)恒轉(zhuǎn)矩負(fù)載特性的機(jī)械，應(yīng)選用機(jī)械特性為硬特性的電動(dòng)機(jī)；對(duì)恒功率負(fù)載特性的機(jī)械，應(yīng)選用變速直流電動(dòng)機(jī)或帶機(jī)械變速的交流異步電動(dòng)機(jī)。24由于直流電動(dòng)機(jī)需要直流電源，結(jié)構(gòu)復(fù)雜，價(jià)格昂貴。因此，當(dāng)交流電動(dòng)機(jī)能滿足工作機(jī)械要求時(shí)，一般不采用直流電動(dòng)機(jī)?，F(xiàn)場(chǎng)一般采用三相交流電源如無(wú)特性要求均應(yīng)采用三相交流電動(dòng)機(jī)。當(dāng)電動(dòng)機(jī)需經(jīng)常起動(dòng)、制動(dòng)和正反轉(zhuǎn)時(shí)（例如起重機(jī)） ，要求電動(dòng)機(jī)有較小的轉(zhuǎn)動(dòng)慣量和較大的過(guò)載能力因此應(yīng)選用起重及冶金用三相異步電動(dòng)機(jī)，常用的為 YZ 或 YZR 系列。24此外，根據(jù)電動(dòng)機(jī)的工作環(huán)境條件，如環(huán)境濕度、溫度、通風(fēng)及有無(wú)防塵、防爆等特殊要求，選擇不同的防護(hù)性能的外殼結(jié)構(gòu)形式。根據(jù)電動(dòng)機(jī)與被驅(qū)動(dòng)機(jī)械的連接形式，決定其安裝方式，一般采用臥式。所以按照工作要求和工作環(huán)境條件選用交流伺服電動(dòng)機(jī)。22.1.2 電動(dòng)機(jī)功率的選擇標(biāo)準(zhǔn)電動(dòng)機(jī)的容量由額定功率表示。所選電動(dòng)機(jī)的額定功率應(yīng)等于或稍大于工作要求的功率。容量小于工作要求則不能保證工作機(jī)正常工作，或電動(dòng)機(jī)長(zhǎng)期過(guò)載、發(fā)熱大而過(guò)早損壞；容量大則增加成本，并且由于功率和功率因數(shù)低而造成浪費(fèi)。27電動(dòng)機(jī)的容量主要有運(yùn)行時(shí)發(fā)熱條件限定，在不變或變化很小的載荷下長(zhǎng)期連續(xù)運(yùn)行的機(jī)械，只要其電動(dòng)機(jī)的負(fù)載不超過(guò)額定值，電動(dòng)機(jī)便不會(huì)過(guò)熱，通常不必校驗(yàn)發(fā)熱和發(fā)起力矩。27 （1）電動(dòng)機(jī)的選擇按照以上工作要求和條件選用交流伺服電動(dòng)機(jī)。初步定電機(jī)轉(zhuǎn)速為960r/min。 （2）功率的計(jì)算T=FS=20009.820010=3920N.3回轉(zhuǎn)工作臺(tái)的轉(zhuǎn)速為：n=960/403=8r/min.電動(dòng)機(jī)的工作效率為：=0.97w工作所需功率： p =Tn/9950=39208/(99500.97)=3.3kw (3.17)ww電機(jī)所需的輸出功率為： p =p /0w- 7 -式中：為電機(jī)至工作臺(tái)之間的總效率。齒輪：=0.97 軸承：=0.9912蝸桿：=0.8 聯(lián)軸器：=0.96 34因此，總效率=0.970.99 0.80.96=0.69.126346 p =p /=3.3/0.69=4.8kw.0w則取電機(jī)額定功率為：p =5.5kw 電機(jī)轉(zhuǎn)速為：n=960r/min.m2.2 齒輪傳動(dòng)的設(shè)計(jì)一級(jí)傳動(dòng)為齒輪傳動(dòng)，其傳動(dòng)比為：i=32.2.1 選擇齒輪傳動(dòng)的類型和材料 1）選用直齒圓柱齒輪傳動(dòng)； 2）工作臺(tái)的轉(zhuǎn)速不高，故選用 7 級(jí)精度； 3）材料選擇。由機(jī)械設(shè)計(jì)中表(10-1)選擇小齒輪材料為 40Cr（調(diào)質(zhì)） ，硬度為 280HBS，大齒輪材料為 45 鋼（調(diào)質(zhì)） ，硬度為 240HBS。1 4）選小齒輪齒數(shù) Z =24，大齒輪齒數(shù)取 Z =72。122.2.2 按齒輪接觸疲勞強(qiáng)度設(shè)計(jì) 由機(jī)械設(shè)計(jì)中設(shè)計(jì)計(jì)算公式（10.9a）進(jìn)行計(jì)算，即 d 2.32 t 123).(1.HEdZuuKT（10.9a） （1）確定公式內(nèi)的各計(jì)算數(shù)值。 1）試選載荷系數(shù) K =1.3。t 2）計(jì)算小齒輪傳遞的轉(zhuǎn)矩。 T =95.510 5.5/960 (3.17)1nPm5105 .955 =5.45710 Nmm 4 3）由機(jī)械設(shè)計(jì)中表(10-7)選取齒寬系數(shù)=1。d 4）由機(jī)械設(shè)計(jì)中表(10-6)查的材料的彈性影響系數(shù) Z =189.8MPa 。1E21 5）由圖(10-21d)按齒面硬度查的小齒輪的接觸疲勞強(qiáng)度極限=600MPa。1limH- 8 -大齒輪的接觸疲勞強(qiáng)度極限=550MPa。12limH 6）由式（10.13）計(jì)算應(yīng)力循環(huán)次數(shù)。 N =60n j=609601(1282508)=1.8410 11hL9（10.13） N =N /3=0.61410219 7) 由圖(10-19)取接觸疲勞壽命系數(shù)=0.90；=0.95。1HNK2HNK 8) 計(jì)算接觸疲勞需用應(yīng)力。取失效概率為 1%，安全系數(shù) S=1，由式（10.12）得 =0.9600=540MPa H1SKHN1lim1（10.12） =0.95550=522.5MPa H2SKHN2lim2（10.12） （2） 計(jì)算 1) 試算小齒輪分度圓直徑 d ，代入中較小值。t 1Hd 2.32=2.32=53.86mmt 123).(1.HEdZuuKT324)5 .5228 .189(3411047. 53 . 1 2）計(jì)算圓周速度。=2.7m/s10006011ndt10006096086.53 3）計(jì)算齒寬 b.b=153.86=53.86mmtdd1 4）計(jì)算齒寬與齒高之比。hb模數(shù) =2.24mmtm11zdt2486.53齒高 =2.25=2.252.24=5.05mmhtm=10.67hb05. 586.53 5）計(jì)算載荷系數(shù)。- 9 -根據(jù)=2.7m/s，7 級(jí)精度，由機(jī)械設(shè)計(jì)中圖(10-8)查的動(dòng)載荷系數(shù)=1.12；K直齒輪，；11FaHaKK由機(jī)械設(shè)計(jì)中表(10-2)查的使用系數(shù)=1；AK小齒輪選用 7 級(jí)精度，=1.423。HK由=10.67，=1.423 查圖(10-13)得=1.35；故載荷系數(shù)1hbHKFK =11.1211.423=1.594 HHVAKKKKK （10.13） 6）按實(shí)際的載荷系數(shù)校正所算得的分度圓直徑，由式（）得a10.10 mm 65.573 . 1594. 186.533311ttKKdd（10.10a） 7）計(jì)算模數(shù)mmm，4 . 22465.5711zdm2.2.3 按齒根彎曲強(qiáng)度設(shè)計(jì) 由機(jī)械設(shè)計(jì)中式（10.5）得彎曲強(qiáng)度的設(shè)計(jì)公式為 3211)(2FSaFadYYzKTm（10.5） （1）確定公式內(nèi)的各計(jì)算數(shù)值 1）由機(jī)械設(shè)計(jì)中圖(10-20c)查得小齒輪的彎曲疲勞強(qiáng)度極限=500MPa；大齒輪的彎曲疲勞強(qiáng)度極限=380MPa；11FE2FE 2）由圖(10-18)取彎曲疲勞壽命系數(shù)=0.85，=0.88；11FNK2FNK 3）計(jì)算彎曲疲勞許用應(yīng)力。取彎曲疲勞安全系數(shù) S=1.4，由式（10.12）得 MPaSKFEFNF57.3034 . 150085. 0111（10.12）- 10 - MPaSKFEFEF86.2384 . 138088. 0222 4）計(jì)算載荷系數(shù)。K=FFVAKKKKK 512. 135. 1112. 11 5）查取齒形系數(shù)。由表 10-5 查得 ；。65. 21FaY226. 22FaY 6）查取應(yīng)力校正系數(shù)。由表 10-5 查得 ；。58. 11SaY764. 12SaY 7）計(jì)算大、小齒輪的并加以比較。FSaFaYY 01379. 057.30358. 165. 2111FSaFaYY（10.4） 01644. 086.238764. 1226. 2222FSaFaYY大齒輪的數(shù)值大。 (2)設(shè)計(jì)計(jì)算mmm68. 101644. 02411047. 5512. 12324取模數(shù)=mm,分度圓直徑mm，算出小齒輪齒數(shù)m5 . 265.571d245 . 265.5711mdz大齒輪齒數(shù) 722432z2.2.4 幾何尺寸計(jì)算 （1）計(jì)算分度圓直徑 由機(jī)械原理中表(5-1)得mm605 . 22411mzdmm1805 . 27222mzd （2）計(jì)算中心距- 11 -mm120218060221dda （3）計(jì)算齒輪寬度mm606011dbd取mm。6021 BB2.3 渦輪及蝸桿的選用與校核2.3.1 選用蝸桿傳動(dòng)類型 根據(jù) GB/T10085-1988 的推薦，采用漸開線蝸桿（ZI） 。1蝸桿轉(zhuǎn)速，其傳動(dòng)比，輸入功率為。min/3201rn 40ikwP52.3.2 選擇材料 因蝸桿的傳動(dòng)功率和速度不大，故蝸桿用鋼；因希望功率高些，耐磨性高45些，故蝸桿螺旋齒面要求淬火，硬度為。蝸桿用鑄錫磷青銅，HRC5545110PZCuSn金屬模鑄造。為了節(jié)約貴重的有色金屬，僅齒圈用青銅制造，而輪芯用灰鑄鐵 HT制造。11002.3.3 按齒面接觸疲勞強(qiáng)度進(jìn)行設(shè)計(jì)由機(jī)械設(shè)計(jì)中式（11.12） ，傳動(dòng)中心距 322)(HEZZKTa（11.12） （1）確定作用在渦輪上的轉(zhuǎn)矩2T 按，估計(jì)效率，則21z8 . 0 (3.17)4mmNinPnPT477500040/3208 . 051055. 9/1055. 91055. 96162262 （2）確定載荷系數(shù)K 取載荷系數(shù)；則1K15. 1AK05. 1K21. 105. 1115. 1vAKKKK （3）確定彈性影響系數(shù)EZ- 12 - 因選用的是鑄錫磷青銅渦輪和鋼蝸桿相配，故。121160MPaZE （4）確定接觸系數(shù)Z 由與的比值=，從圖()中可查得。11daad135. 018119 . 2Z （5）確定許用接觸應(yīng)力H從機(jī)械設(shè)計(jì)中表()查得渦輪的基本許用應(yīng)力。711MPaH268應(yīng)力循環(huán)次數(shù) 7210536. 182508816060hLjnN（10.13）壽命系數(shù)87710536. 110HNK95. 0則 MPaKHHNH6 .25426895. 0 （6）計(jì)算中心距 (11.12)mma297)2189 . 2160(477500021. 132 取中心距，因，故從文獻(xiàn)機(jī)械設(shè)計(jì)中表()1取模數(shù)amm35040i211，蝸桿分度圓直徑。這時(shí)，從圖()中可查得接觸mmm8mmd7012 . 01ad1811系數(shù)，因此，因此以上計(jì)算結(jié)果可用。174. 2ZZZ 2.3.4 蝸桿與渦輪的主要參數(shù)與幾何尺寸 （1）蝸桿 軸向齒距；直徑系數(shù)；齒頂圓直徑；齒根圓mmpa133.2510qmmda851直徑；分度圓導(dǎo)程角；蝸桿軸向齒厚。1mmdf6013618115664.12asmm（2）渦輪 渦輪齒數(shù)；變位系數(shù)；822Z5 . 02x 驗(yàn)算傳動(dòng)比，這時(shí)傳動(dòng)比誤差為，是允許的。4128212ZZi%5 . 2404041- 13 - 渦輪分度圓直徑65682822 mZdmm 渦輪的喉圓直徑672826562222aahddmm 渦輪齒根圓直徑mmhddff8 .63682 . 126562222 渦輪咽喉母圓半徑mmdarag6 .318 .6362135021222.3.5 校核齒根彎曲疲勞強(qiáng)度53. 12212FFaFYYmddKT 當(dāng)量齒數(shù) 96.86)31.11(cos82cos3322zzv 根據(jù)，從文獻(xiàn)機(jī)械設(shè)計(jì)中圖()中可查的齒形系96.86, 5 . 022vzx1911數(shù)。87. 22FaY 螺旋角系數(shù)9192. 014031.1111401Y 許用彎曲應(yīng)力 FNFFK 從表(）中查得由制造的渦輪的基本許用彎曲應(yīng)力811110PZCuSn。1MPaF56 壽命系數(shù) 644. 01022. 510976FNKMPaMPaF086.36644. 05648.439192. 087. 2865670477500021. 153. 1FMPa彎曲強(qiáng)度是滿足的。2.3.6 驗(yàn)算效率 )tan(tan)96. 095. 0(v（11.20a)- 14 - 已知；與相對(duì)滑動(dòng)速度有關(guān)。31.11vvfarctanvfsv smndvs/45. 231.11cos10006032070cos10006011（11.12） 從機(jī)械設(shè)計(jì)中表()用插值法查得、；代入式18110204. 0vf1687. 1v中得，大于原估計(jì)值，因此，符合要求。184. 0 軸的計(jì)算與校核4 . 2 齒輪軸的設(shè)計(jì)與校核1 . 4 . 2 . 求輸入軸上的功率，轉(zhuǎn)速和轉(zhuǎn)矩11P1n1T 取軸承效率=，聯(lián)軸器效率 則199. 096. 02211PP 2 . 596. 099. 05 . 5kwmin/9601rn (3.17)mmNnPT2 .517299602 . 595500009550000111 . 求作用在齒輪上的力2 已知高速小齒輪的分度圓直徑為1dmm60 齒輪軸所受的力如下圖所示：- 15 -圖 齒輪軸受力圖1 . 2NdTFt31.1724602 .5817292211NFFtr6 .62720tan31.172420tan0aF 初步確定齒輪軸的最小直徑. 3 齒輪軸的結(jié)構(gòu)如下圖：圖 齒輪軸的結(jié)構(gòu)圖2 . 2 選取軸的材料為鋼，進(jìn)行調(diào)質(zhì)處理。根據(jù)文獻(xiàn)機(jī)械設(shè)計(jì)中表()，45315- 16 -取，于是得1120A (15.2)mmnPAd209602 . 511233110min 輸入軸的最小處安裝聯(lián)軸器，為了使所選軸直徑與聯(lián)軸器的孔徑相-d-d適應(yīng)，故需同時(shí)選取聯(lián)軸器的型號(hào)。 聯(lián)軸器的計(jì)算轉(zhuǎn)矩，查機(jī)械設(shè)計(jì)中表()，取,則：1TKTAca1143 . 1AKmmNTKTAca96.642472 .517293 . 11 查標(biāo)準(zhǔn)，選用型凸緣聯(lián)軸器，其公稱轉(zhuǎn)矩為20035843/TGB4GYH。半聯(lián)軸器的孔徑，故取，半聯(lián)軸器長(zhǎng)度mmN 224000mmd30-dmm30，半聯(lián)軸器與軸配合的轂孔長(zhǎng)度。1mmL82mmL501 . 軸的機(jī)構(gòu)設(shè)計(jì)4 (1) 擬定軸上零件的裝配方案 (2) 根據(jù)軸向定位的要求確定軸的各段直徑和長(zhǎng)度 mm40-dmmL52- mmd48-mmL38- mmd64-mmL8- mmd48-mmL32- mmd40-mmL56- mmd30-mmL54- （3）軸上零件的周向定位 齒輪、半聯(lián)軸器與軸的周向定位均采用平鍵連接。按由文獻(xiàn)機(jī)械設(shè)計(jì)-d中表()1得。同時(shí)為了保證齒輪與軸的配合有良好的對(duì)中16mmlhb28914性，故選擇齒輪輪轂與軸的配合為，同樣半聯(lián)軸器與軸連接，選用平鍵為67nH，半聯(lián)軸器與軸的配合為。滾動(dòng)軸承與軸的周向定位是由mmlhb327867kH- 17 -過(guò)度配合來(lái)保證的，為。167mH （4）確定軸的倒角尺寸參照機(jī)械設(shè)計(jì)表()，取軸端倒角為。215455 . 1 5. 求軸上的載荷 齒輪軸上的應(yīng)力分析圖如下 - 18 -圖 齒輪軸應(yīng)力分析3 . 2 從軸的受力情況可以看出截面是軸的危險(xiǎn)截面?，F(xiàn)將計(jì)算出截面上的、BHM及的值列于下表VMM表 齒輪軸危險(xiǎn)截面應(yīng)力1 . 2載荷水平面H垂直面H力F，NFNH2 .1801NFNH7 .4772，NFNV5 .651NFNV45.1732彎矩MmmNMH2 .2866mmNMV7 .1040總彎矩mmNMMMVH10.306822扭矩TmmNT17846 6. 按彎扭合成應(yīng)力校核軸的強(qiáng)度 只需校核軸的危險(xiǎn)截面，故取，軸的計(jì)算用力6 . 0 (15.5) MPaWTMca6 . 3351 . 0)178466 . 0(10.3068)(32222 前已選定軸的材料為鋼，調(diào)質(zhì)處理，由機(jī)械設(shè)計(jì)軸表()查的45115。因此，故安全。1MPa6011ca2.4.2 蝸桿軸的設(shè)計(jì)與校核 1. 求輸出軸上的功率、轉(zhuǎn)速和轉(zhuǎn)矩。2P2n2T齒輪的傳動(dòng)效率為，軸承為，則97. 0199. 02kwPP0 . 599. 097. 02 . 52112min/320396012rinn mmNnPT75.1492183200 . 595500009550000222（3.17） 2. 求作用在齒輪上的力 大齒輪的分度圓直徑為mmd1802- 19 -NdTFt165818075.1492182222NFFtr5 .60320tan165820tan0aF 3. 初步確定軸的最小直徑 先估計(jì)軸的最小直徑。選取軸的材料為鋼，進(jìn)行調(diào)質(zhì)處理。1根據(jù)表（45)，取,于是得3151120A (15.2)mmnPAd283200 . 511233220min取mmd40min取軸兩端直徑為mm45 4. 軸的結(jié)構(gòu)設(shè)計(jì) (1) 擬定軸的結(jié)構(gòu)圖圖 蝸桿軸結(jié)構(gòu)圖4 . 2 (2). 確定軸的各段直徑和長(zhǎng)度- -dmm40lmm132- -dmm45lmm90- -dmm54lmm80- -dmm85lmm240- -dmm54lmm80- -dmm45lmm14- 20 - -dmm40lmm73 (3). 軸端倒角為。455 . 1 5. 軸的受力分析 蝸桿軸的受力分析如下圖:圖 蝸桿軸受力圖5 . 2根據(jù)機(jī)械設(shè)計(jì)中式（11.7)、 （11.8）和（11.9）得 （11.7）1122dTFt1 2222dTFa（11.8） tan22trFF（11.9）代入數(shù)值計(jì)算得：NFt6 .12632NFa7 .6352NFr9 .4592蝸桿軸的應(yīng)力分析如下圖:- 21 - 圖 2.6 蝸桿軸應(yīng)力分析圖 從軸的受力情況可以看出截面是軸的危險(xiǎn)截面?，F(xiàn)將計(jì)算出的截面處的B- 22 -、及值列于下表，如下表所示：HMVMM表 蝸桿軸的危險(xiǎn)截面應(yīng)力2 . 2載荷水平面H垂直面V力F，NFNH8 .9951NFNH8 .7362，NFNV73.551NFNV17.2342彎矩1MNMH6 .1242981NMV48.395041總彎矩MNMMMVHH1304242121扭矩TNT50643 . 按彎扭合成應(yīng)力校核軸的強(qiáng)度5 只需校核危險(xiǎn)截面，故取，軸的計(jì)算應(yīng)力6 . 0 MPaWTMca0 . 6)8 .60(1 . 0)506436 . 0(130424)(3222221（15.5） 前已選定軸的材料為鋼，調(diào)質(zhì)處理，由機(jī)械設(shè)計(jì)中表（）查的45115，因此，故安全。1MPa6011ca2.5 軸承的計(jì)算與選用 以蝸桿為例，蝸桿軸選用圓錐滾子軸承 30309 其基本額定動(dòng)載荷 Cr=130KN，基本額定靜載荷 C0r=158KN 蝸桿軸所受到的軸向力，切向力，徑向力如下圖：- 23 -圖 2.7 蝸桿軸受力圖2.5.1 軸承受到的載荷 1）由軸的計(jì)算結(jié)果得，軸承受到載荷FNH1=995.8N FNH2=736.8NFNV1=55.73N FV2=234.17N Fr1=FN1=N 7 .99773.558 .995222121NVNHFF（13.3） Fr2=FN2=N 77317.2348 .736222222NVNHFF 軸承所受的力如下圖：圖 2.8 軸承受力圖FA=6357NFr1=997N Fr2=773NFd1=eFr1=0.4997=398.8N Fd2=eFr2=0.4773=309.2N FA+Fd2Fd1 所以：1.壓緊 2.放松 Fa1=FA+Fd2=6357+309.2=6666.2N （13.11a) Fa2=Fd2=309.2N (13.12b) 3）球軸承當(dāng)量動(dòng)載荷 P1和 P2eFFra69. 69972 .666611- 24 -eFFra2 .3092 .30922 由機(jī)械設(shè)計(jì)中表(13-5)分別進(jìn)行查表或插值計(jì)算得徑向載荷系數(shù)和軸向載荷系數(shù)為 對(duì)軸承 1 對(duì)軸承 2 4 . 01x5 . 11y4 . 02x5 . 12y 按表(13-6)，取 fp=1.5 P1=fp(x1Fr1+y1Fa1)=1.5(0.4997+1.56666.2)=15597.2N (13.8a)P2=fp(x2Fr2+y2Fa2)=1.5(0.4773+1.5309.2)=1159.5N2.5.2 驗(yàn)算軸承壽命 P1P2，所以按軸承 1 的受力大小驗(yàn)算 (13.5)hhLhPCnL156215)2 .1559710130(3206010)(60103103616故選用軸承滿足壽命要求。- 25 - 5 結(jié) 論 經(jīng)過(guò)此次長(zhǎng)達(dá)幾個(gè)月的設(shè)計(jì)，讓我體會(huì)到了那些設(shè)計(jì)師們的艱辛。僅僅一次的設(shè)計(jì)，我就感到有一些力不從心。雖然再設(shè)計(jì)過(guò)程中出現(xiàn)了很多問(wèn)題，但通過(guò)老師的細(xì)心講解與自己的不懈努力，最終完成了這次可以說(shuō)是一個(gè)人生轉(zhuǎn)折點(diǎn)的設(shè)計(jì)。這次的設(shè)計(jì)，讓我將這大學(xué)四年來(lái)所學(xué)的只是得到了很好的運(yùn)用，并將其進(jìn)行了一個(gè)系統(tǒng)化的整理，高興的是我還沒(méi)有將這些知識(shí)忘掉，而這次的設(shè)計(jì)又將我所學(xué)的知識(shí)進(jìn)行了鞏固，我想這是學(xué)校讓我們做設(shè)計(jì)的一個(gè)重要的目的吧。讓即將進(jìn)入社會(huì)的我們可以有一個(gè)對(duì)所學(xué)專業(yè)的重新認(rèn)識(shí)，給我們以后的工作打下堅(jiān)實(shí)的基礎(chǔ)。我所設(shè)計(jì)的課題（數(shù)控回轉(zhuǎn)工作臺(tái)）聽起來(lái)很簡(jiǎn)單，但當(dāng)我拿到這個(gè)課題的時(shí)候，有種無(wú)從下手的感覺，但在導(dǎo)師的講解下和和通過(guò)自己對(duì)資料的查找，明白了數(shù)控回轉(zhuǎn)工作臺(tái)的工作原理，通過(guò)自己的設(shè)計(jì)，時(shí)期在通用工作臺(tái)的基礎(chǔ)上增加了齒輪傳動(dòng)與渦輪蝸桿傳動(dòng)機(jī)構(gòu)，再在原動(dòng)力（伺服電機(jī)）的驅(qū)動(dòng)下使工作臺(tái)進(jìn)行了旋轉(zhuǎn)，從而有普通的工作臺(tái)變成了回轉(zhuǎn)工作臺(tái)。 通過(guò)此次設(shè)計(jì)，我明白了所有的東西并不都是很完美，都是通過(guò)不斷地改進(jìn)和完善才能使其做到盡量的完美。使其性能越來(lái)越好，更能體現(xiàn)他的價(jià)值。- 26 -參 考 文 獻(xiàn)1 濮良貴,紀(jì)名剛.機(jī)械設(shè)計(jì)M,第八版.北京:高等教育出版社,2006:186-3832 吳宗澤,高志.機(jī)械設(shè)計(jì)課程設(shè)計(jì)手冊(cè)M,第四版.北京:高等教育出版社,2006:58-1023 羅良武,趙勤,王嫦娟.畫法幾何及工程制圖M,第二版.北京:機(jī)械工業(yè)出版社,2008:80-2574 馮清秀,鄧星鐘.機(jī)電傳動(dòng)控制M,第五版.武漢:華中科技大學(xué)出版社,2011:11-505 鄭文偉,吳克堅(jiān).機(jī)械原理M,第七版.北京:高等教育出版社,2005:52-1526 鄭金星.機(jī)械制造裝備設(shè)計(jì)M.哈爾濱:哈爾濱工程大學(xué)出版社,2006:14-1527 薛蒲昌.基于 PID 的數(shù)控機(jī)床工作臺(tái)電液位置伺服系統(tǒng)分析J.信息技術(shù),2009,(6):107-1098 崔旭芳.數(shù)控回轉(zhuǎn)工作臺(tái)的原理與設(shè)計(jì)J.技術(shù)交流,2008,(3):102-1039 顧華鋒.數(shù)控機(jī)床回轉(zhuǎn)工作臺(tái)動(dòng)態(tài)性能分析與仿真J.機(jī)床與液壓,2008,(36):216-22010 王友林.數(shù)控雙轉(zhuǎn)軸式回轉(zhuǎn)工作臺(tái)的結(jié)構(gòu)與工作原理J.煤礦機(jī)械,2009,(30):102-10311 張立瑩.數(shù)控回轉(zhuǎn)工作臺(tái)加緊機(jī)械淺析J.制造技術(shù),2001,(3):102-10312 鐘雯.機(jī)械類設(shè)計(jì)課題精選M.北京:化學(xué)工業(yè)出版社,2010:10-4513 楊萍.數(shù)控工作臺(tái)設(shè)計(jì)J.組合機(jī)床自動(dòng)化加工技術(shù),1996,(8):18-4214 Duke K. Improving Gear Pump Relief Groove DesignJ.Prec. Natl. Conf. Fluid Power,2007:7-3015 Xiaojin Fu,Guohua Yan.The Fuzzy Optimization Design of the Gear PumpJ.Interational Conference on Agile Manufacturing(ICAM 2003),2003:337-341- 27 -致 謝四年的大學(xué)生活即將結(jié)束，在大學(xué)的最后一段時(shí)間里，我們完成了設(shè)計(jì)。在這里，我非常感謝我的導(dǎo)師和陪我在一起做設(shè)計(jì)的同學(xué)們，是你們陪我度過(guò)了大學(xué)的最后一段時(shí)光。我很感謝我的導(dǎo)師，你不辭辛苦為我們精心的講解，在此次設(shè)計(jì)中，由于所學(xué)知識(shí)不系統(tǒng)，無(wú)法運(yùn)用到實(shí)際中，因此遇到了很多的問(wèn)題，使我感到很迷茫。而您總是耐心的給我們講解，講解其中的設(shè)計(jì)原理，當(dāng)你發(fā)現(xiàn)我們的錯(cuò)誤時(shí)，及時(shí)為我們糾正，讓我們少走了很多彎路。再就是我也感謝我的同學(xué)們，你們的幫助也是我解決了不少設(shè)計(jì)中的技術(shù)難題。最后感謝學(xué)校在我們即將離校，步入社會(huì)時(shí)給了我們這次實(shí)踐機(jī)會(huì)，還給我們提供了良好的學(xué)習(xí)環(huán)境，同時(shí)感謝評(píng)閱老師們，在炎熱的夏季抽出寶貴的時(shí)間來(lái)評(píng)閱這片設(shè)計(jì)。Part program automatic check for three axis CNC machines Roberto Licaria,*, Ernesto Lo Valvob, Mario PiacentiniaaUniversita di Palermo, Palazzo Steri Piazza Marina, 61-90133 Palermo, ItalybUniversita di Catania, Catania, ItalyAbstractThe simulation and verification of NC codes for CNC machining is a very important task. The aim of this work is to limit the number ofcutting tests needed to verify the right writing of the part program for a CN milling machine in the intent of saving time, human resourcesand money. This is obtained through the Boolean operation among solids, in AutoCAD environment, of the volume covered by the toolduring the operations ruled by the part program. # 2001 Published by Elsevier Science B.V.Keywords: CNC machines; AutoCAD; Part program1. IntroductionWe have recently attendedtothe irreversibledevelopmentof computers, that now are cheaper, more friendly and,consequently, more diffused in modern industries. Compu-ters have been used in the industry sector for several years indifferent stages: in the design stage using CAD systems;in the process planning stage using CAPP systems; in theproduction stage using CAM systems.Since afewyearsago,thesethreestages were isolated oneby another and each stage should have answered specificproblems and questions. Sometimes it happened that theproduction stage imposed some essential conditions to theother stages (as an example, when the designer establishesthe tolerance for the piece; or when it is necessary to makesome change to the piece during the production stage sincethere is an impossible or difficult machine production), butthe three stages were strictly separated.Moreover, it was thought that it was impossible fordifferent programs, written by different programmers withdifferent logics, to speak to each other. Recently,different programs tried to communicate in order to solvesome problems, but this is very difficult to be achieved.There exist a number of programs which are able toperform that way, but they are not universal programs:they are very specialized programs which can be used onlyin specific fields using powerful computers. As a matter offact,itisnecessarytodevelopauniversalsoftwareeasytobeused by a simple, common and very cheap PC.Numerical Control machines are very commonly used fortheir ability to help industries to achieve an increase inproductivity and in quality at the lowest costs. As a matter offact, NC machines are faster and more precise than tradi-tional ones and they work very accurate surfaces, but aremore expensive and it is more difficult to use them than thetraditional ones.Moreover, it is necessary to compile a specific program tobe read by the machine control unit in order to obtain thedata needed to exactly move the tool. This program (calledpart program) is written using a particular programminglanguage that can be read by every NC machine (machineshave to be similar: turning machines, end milling machines,etc.).The first problem we meet using NC machines is thatwhen the programmer makes a mistake in writing the partprogram, the piece will not be realized the way we want, butit will have a different shape or different features. But itcould be more dangerous (and also expensive) if the pro-grammingmistakegivesthetoolamotioncommandthatcangenerate a collision between the tool and the fixed parts ofthe machine, because of the speed of the NC machine tool ishigher than that of the traditional machine tool.We have other problems using NC machines, for examplehow to choose the right depth or feed rate or how to choosethe shape of the workpiece in order to minimize the materialwaste. As a rule, in order to solve these problems somecutting tests are realized, but they are very expensive to beimplemented since they are a waste of human resources,time, materials and money.Moreover, not all the problems are very easy to be solvedbyimplementingonetestonly,sothatthetesthastobemadeagain over and over. It should be really useful to makevirtual cutting tests using computers instead of NCmachines and as much useful should be the possibility toJournal of Materials Processing Technology 109 (2001) 290293*Corresponding author.0924-0136/01/$ see front matter # 2001 Published by Elsevier Science B.V.PII: S0924-0136(00)00812-8display the space regions crossed by the machine tool duringthe processing work.The diffusion of electronic realistic representation sys-temsofmechanicalpiecessuggestsustousetheminordertorealize a virtual simulation of the cutting tests for the threeaxis end milling machine 15.Our task was to create a software which can directly readand interpret the part program and display it using theAutoCAD solid modeler. Our software makes it possibleto compare the tested piece on the screen either with theproject piece or with the workpiece, and it shows the toolpath, so that dangerous collisions can be monitored.2. The cutting processThe cutting process is the result of an interferencebetween the tool and the workpiece, and it can be simulatedby a number of Boolean operations between primitives.The tool, an end milling tool, can be represented by arevolution AutoCAD solid. The tools swept volume canbe represented by surfaces, while edges and vertexes of thisvolume are created by the tool motion. Every primitivecreates its own swept volume, depending on the motiondirection. For example, a cylindric tool can move followinga line which can be parallel or orthogonal to the tool axis. Inthe first case,the swept volume is a higher cylinder, in thesecond case the swept volume is a combination of a boxand two half cylinders.A cutting process on a circular line can be represented bythe motion of a closed polyline (the tools cross-section)around a revolution axis (Fig. 1). These solids can besubtracted from the solid representing the workpiece, inorder to simulate the end milling cutting process.3. AutoCADAutodesks AutoCAD was the most popular and verypowerful CAD software for PC since it was introduced in1982. It has always been providing AutoLISP and ADSprogramming interfaces in order to develop customizedapplications. ADS is more efficient and easier to be usedthan LISP and it has been offered as an alternative interfacesince version R11. ADS uses ANSI-C as the programminglanguage since it has been the most widely accepted lan-guage for the development of miscellaneous applications. Itcan also use all portable ANSI-C libraries.We developed our software in 1996 using AutoCAD R12.At that time AutoCAD used AME for solid modeling, but ithas switched to ACIS standard since version R13. With thenewly released R14, we decided to upgrade our softwarebecause of the ACISs faster computing efficiency and moreprecise description of solids. Moreover, it reduces the size ofthe drawing files. As a consequence, ACIS is able to handlevery complicated models much better than AME can.4. The developed softwareOursoftwareiswrittenusingClanguagetobeexecutedinAutoCAD ADS environment with some instructions pecu-liar to AutoCAD commands execution 6,7.The software is divided into two fundamental parts:? The first part creates an interface between the part pro-gram and the AutoCAD ambient.? The second part makes the part program data ready to beread and interpreted.The part program contains some instructions about thetool path (Gxx instructions), geometrical characteristics(like points coordinates or joint radius), technological char-acteristics (feed rate, spindle speed, etc.): the softwareinterprets the geometrical instructions only.The software runs inside AutoCAD and the operator candraw the workpiece or load it as an external file, choose thetool shape (there are four types of tool: cylindric, cylindricball-end, half sphere, sphere) and its dimensions: the soft-ware calculate and draw the cross-section of the tool that isan AutoCAD polyline (Fig. 2). Now the operator has to loadthe part program and the simulation can start.Fig. 1. Tools swept volume.Fig. 2. Tool options.R. Licari et al./Journal of Materials Processing Technology 109 (2001) 290293291The procedure, first of all, analyses the geometricalcharacteristics and organizes them in a chronological order(for example: the X-coordinate of the start point of a genericmotion is called oldX, the X-coordinate of the end point iscalled valX.After this first step, the software interprets the motioninstructions (G00, G01, G02 and G03) given by the partprogram and draws them through the AutoCAD commandsExtrude and Revolve. The Extrude AutoCAD com-mand can add the 3D to a 2D closed polyline, whereas theRevolve AutoCAD command realizes a revolution solidfrom a 2D closed polyline.TheG00instructionrepresentsthemotionsofthetoolwhenit does not touch theworkpiece: in our work it is representedby a prismatic AutoCAD solid. The cross-section of thissolid is the same as the tool and it is obtained by Extrudecommand. The simulation of this motionis useful in order toverify the possibility of a collision with fixturing.The G01 instruction represents the motions of the toolwhen it touches the workpiece: in our work it is representedby a prismatic AutoCAD solid. The cross-section of thissolid is still the same as the tool and it is obtained by theExtrude command. The Extrude AutoCAD commanduses a segment; its start point has oldX, oldY, oldZas coordinates and its end point has valX, valY, valZas coordinates.NoticethatinordertoexecutetheExtrudecommand,itisnecessary tohave the Z-axis aligned with that segmentandthe polyline lying on the XY plane. For this reason we havecreated the same instructions to change the AutoCADcoordinate system (UCS: user coordinate system).The G02 and the G03 instructions are represented byrevolution solids. These solids are created by the rotation ofthe cross-section of the tool around a revolution axis. Thisaxis starts from the center of the fillet and is perpendicular tothe XY plane.As the part program does not include the informationsneeded by AutoCAD in order to draw this solid, it wasnecessary for us to realize some calculation subroutines inorder to obtain the essential information from the partprogram data. Now the operator can start the simulation.Hechoosestheworkpiece(orhedrawsit)andhechoosestheshape and the dimension of the tool; the software automa-tically draws a polyline and puts it in the so-called restpoint, far away from the workpiece. The tool has aprogramming point: it is the point that follows the partprogram trajectory (Fig. 3).When our software processes a G00 or G01 instruction, ithas two options:1. The start point Z-coordinate is different from the endpoint Z-coordinate: we have a vertical motion and thesoftware draws a cylinder with the same radius of thetool and h ? ?Z2? Z1?.2. The start point Z-coordinate is the same as the end pointZ-coordinate: the tool moves on the XY plane and thesoftware makes a copy of the polyline cross-section ofthe tool and moves it towards the start point of themotion. The software changes the UCS (the Z-axis isaligned with the segment from the start point to the endpoint) and rotates the polyline since it has to beperpendicular to the Z-axis. Now the polyline can beextruded and the software draws a solid representing thetool motion (Fig. 4).When our software processes a G02 or a G03 instruction,the tool moves on the XY plane and the software makes acopy of the polyline cross-section of the tool and moves ittowards the end point (G02) or the start point (G03) of themotion. The result of this procedure is the revolution axis,the revolution of the polyline and the drawing of a solidrepresenting the tool motion (Fig. 5).At the end of the simulation, the operator can see on themonitor of his PC the complete tool path. But he has now aFig. 3. Tools programming point.Fig. 4. G01 command simulation.292R. Licari et al./Journal of Materials Processing Technology 109 (2001) 290293CAD file: this tool path is an AutoCAD solid, which can bemeasured, which perspective can be changed, which volumecan be calculated. He can also use another AutoCADcommand: the Subtract command by which he obtainsthe final shape of the workpiece and he can measure it, hecan change the viewpoint or obtain geometric informationon volume, center of gravity and so on.We have tested our software using some part program andthe results have been very flattering: it was very easy, fastand cheap to make these simulations. In Fig. 6 is reported asample image obtained with our software.Thesamplerepresentsaworkpieceof300mm?300mm ? 50mm mold-base steel with a central hole (dia-meter of 175 mm). The image shows the fixturing and themachinedpart witha ball-endtool (diameter of40 mm).Theapproximated simulation time for this piece is less than1 min using a Personal Computer equipped with a Pentium133 MHz processor and 32 MB memory RAM. So it ispossible to repeat the cutting simulation by changing thegeometrical parameters in a few minutes, in order to opti-mize the programming stage.5. ConclusionsThe part program check is very expensivein terms of timeand human resources if it is manually made. Thanks to theability to correct programming mistakes after the post-processing stage, many cutting tests can be cancelled, andthe machine functionally used. The developed software is avalid support to easily and quickly verify the part program.As a matter of fact, it can be integrated with a powerfulcommon CAD software that can manage a solid modeler.Thanks to it, the designerprogrammer is able to immedi-ately see the piece and the mistakes of the shape or of thecutting process. Moreover, since the rendering image ofsimulated results can closely represent the machined part,this software provides a better approach for NC simulationand verification on Personal Computer.The simulated figure is a solid model that can give all thatgeometric information impossible to be produced by anyother simulation procedures (such as volume, center ofgravity, etc.). In addition, the solid model can also bedisplayed from different perspectives able to give a realisticrepresentation of the piece. The model can also be manipu-lated for further application. Moreover, this software cansimulate complicated part programs in a few minutes usinga cheap Personal Computer and a very common CADsoftware.References1 W.P. Wang, K.K. Wang, Geometric Modeling for Swept Volume ofMoving Solids, IEEE CG&A, 1986, pp. 817.2 W.P. Wang, Solid modeling for optimizing metal removal of three-dimensional NC end milling, J. Manuf. Syst. 7 (1) (1988) 5765.3 C. Leu, S.H. Park, K.K. Wang, Geometric representation of translationswept volumes and its applications, J. Eng. Ind. 108/113 (1986) 113119.4 C.B. Kim, S.H. Park, M.Y. Yang, Verification of NC tool path andmanual automatic editing of NC code, Int. J. Prod. Res. 33 (3) (1995)659673.5 W.R. Jong, J.S. Chen, The simulation and verification of NC-paths bysolid modeler interface, in: Proceedings of the Fourth InternationalConference on Automation Technology, 1996, pp. 331337.6 Autodesk, ADS AutoCAD Development System ProgrammersReference Manual, 1992.7 Autodesk, AutoLISP and API under AME Release 2.1 ReferenceManual, 1992.Fig. 5. G02 command simulation.Fig. 6. Rendered image of a simulation.R. Licari et al./Journal of Materials Processing Technology 109 (2001) 290293293
收藏