三維數(shù)控工作臺的設(shè)計與開發(fā)【含CAD高清圖紙和文檔】【GC系列】
【溫馨提示】=【1】設(shè)計包含CAD圖紙 和 DOC文檔,均可以在線預(yù)覽,所見即所得,dwg后綴的文件為CAD圖,超高清,可編輯,無任何水印,充值下載得到【資源目錄】里展示的所有文件=【2】若題目上備注三維,則表示文件里包含三維源文件,由于三維組成零件數(shù)量較多,為保證預(yù)覽的簡潔性,店家將三維文件夾進行了打包。三維預(yù)覽圖,均為店主電腦打開軟件進行截圖的,保證能夠打開,下載后解壓即可。=【3】特價促銷,拼團購買,均有不同程度的打折優(yōu)惠,詳情可咨詢QQ:1304139763 或者 414951605=【4】 題目最后的備注【GC系列】為店主整理分類的代號,與課題內(nèi)容無關(guān),請忽視
哈爾濱理工大學(xué)學(xué)士學(xué)位論文三維數(shù)控工作臺的設(shè)計與開發(fā)摘要在當前生產(chǎn)中的許多機械設(shè)備中均需要精密定位,而其中的三維精密定位工作臺作為關(guān)鍵部件將直接影響其整機的性能和精度。為保證機器性能,工作臺要在X方向和Y方向?qū)崿F(xiàn)快速準確的定位,并且要求在Z方向能夠?qū)崿F(xiàn)精確調(diào)整和定位,要實現(xiàn)快速和準確定位,必須對工作臺進行改裝,使用步進電機和控制卡。本文設(shè)計的工作臺就是基于單片機控制的三維數(shù)控工作臺。本次研究的課題的主要內(nèi)容包括:充分利用實驗室中廢舊的二維工作臺,通過對硬件諸如直線導(dǎo)軌,深溝球軸承,滾珠絲杠,步進電機等的選擇并對零件的整體連接結(jié)構(gòu)進行設(shè)計從而組裝出一臺可運轉(zhuǎn)的三維工作臺;利用三維建模軟件對所選擇的工作臺的各部分零件進行建模,裝配,并對裝配好的三維工作臺實現(xiàn)運動仿真;利用VB語言對插補程序進行軟件設(shè)計;需要完成對三維工作臺的控制系統(tǒng)的設(shè)計,主要包括對開閉環(huán)的選擇,對80C51單片機功能的充分認識并編寫控制程序,充分理解、學(xué)習(xí)插補技術(shù)在三維數(shù)控工作臺中的應(yīng)用。通過上述研究內(nèi)容,我們可以的到一臺經(jīng)濟,實用,精密度較高的三維數(shù)控工作臺,通過與普通工作臺的比較,我們可以從中得出插補技術(shù)對于數(shù)控工作臺的影響。可以說將插補技術(shù)應(yīng)用到現(xiàn)代數(shù)控加工已經(jīng)是一個不可逆轉(zhuǎn)的趨勢,因此本課題具有很高的研究價值。關(guān)鍵詞 數(shù)控系統(tǒng);三維工作臺;單片機;插補技術(shù)Design and development of 3D NC workbenchAbstractTo study the influence of the parameters of open NC servo feed systems and spatial geometry error on the precision and find methods to realize the high precision control of numerical control (NC) system, the development of the control system of a two-axis NC worktable ,consisting of ball screws and linear roller guides, was presented in this thesis. The system is based on an open architecture PMAC (Programmable multi-Axis controller) motion control card to realize real-time control. Some experiments concerning control test and error measurement and analysis can be carried out on the designed worktable. At first, the configuration of control system of the 3D NC worktable Was proposed ,and its software was developed. Modular software development concept featured the system design, which includes the following modules: machining position and speed sampled display module; file management module; parameters setting module; error diagnosis module; precision analysis module; manual debugging module; machine simulation module; help module.As one of focuses, the error measurement and precision analysis of the worktable were emphasized in the development of the system software. Series of experiments about system control and precision were made on the worktable. The precision characteristics of the half-loop and closed-loop position feedbacks were analyzed. Through comparing the theoretical analysis with the data collected from experiments ,a conclusion has been drawn that the smallest contour error will be got if the two axes have the same servo characteristics. The ball-bar ,which is considered to be more reliable than linearscales in measuring contour error, was used to measure the circular motion of the system. The experiment result showed that the contour error of the system was big .By analysis of the error source based on a mathematical model of the measuring system proposed in this thesis, it was found that it was the installation inclination of linear scales that caused so big error. By compensating the error with the measured result by the ball-bar ,the precision of the control system had been improved.Keywords Numerical Control System;three-dimensional NC workbench;SCM;Interpolation technique;III目錄摘要IAbstractII第1章 緒論11.1課題研究的意義11.2課題研究的現(xiàn)狀11.3課題研究的主要內(nèi)容2第2章 三維數(shù)控工作臺的硬件選擇及連接結(jié)構(gòu)32.1三維數(shù)控工作臺的工作原理介紹32.2三維數(shù)控工作臺的基本結(jié)構(gòu)32.3步進電機的選擇42.4絲杠的選型與校核52.4.1滾珠絲杠的簡單介紹52.4.2滾珠絲杠的選型72.4.3滾珠絲杠的校核82.5直線導(dǎo)軌的選型與計算92.5.1直線導(dǎo)軌的簡單介紹92.5.2直線導(dǎo)軌的選型102.6聯(lián)軸器的選型122.6.1聯(lián)軸器的簡介122.6.2聯(lián)軸器的選型132.7軸承選型142.8本章小結(jié)16第3章 三維數(shù)控工作臺的Pro/E三維建模173.1 Pro/E建模軟件簡介173.2 Pro/E界面介紹173.3零件三維建模實例介紹183.3.1新建文件183.3.2建立拉伸特征193.3.3建立螺旋特征203.3.4建立螺母副特征203.3.5進行顏色和外觀設(shè)計213.4其余零件三維建模圖展示223.5三維數(shù)控工作臺裝配233.6本章小結(jié)25第4章 三維工作臺的軟件及控制系統(tǒng)設(shè)計264.1逐點比較法直線插補的簡介264.2逐點比較法直線插補的計算步驟264.3數(shù)控插補仿真軟件的說明294.4開環(huán)系統(tǒng)控制原理304.5單片機設(shè)計304.6本章小結(jié)35結(jié)論36致謝37參考文獻38附錄一39附錄二491第1章 緒論1.1課題研究的意義目前在多種機械設(shè)備中均需要精密定位,而其中的三維精密定位工作臺作為關(guān)鍵部件將直接影響其整機的性能和精度。為保證機器性能,工作臺要在X方向和Y方向?qū)崿F(xiàn)快速準確的定位,并且要求在Z方向能夠?qū)崿F(xiàn)精確調(diào)整和定位,要實現(xiàn)快速和準確定位,必須對工作臺進行改裝,使用步進電機和控制卡。插補技術(shù)是數(shù)控技術(shù)中的核心技術(shù),它的好壞直接影響著數(shù)控加工精度進而影響數(shù)控加工技術(shù)的優(yōu)劣,是目前數(shù)控技術(shù)急需提高、完善的環(huán)節(jié)之一,而插補算法的選擇直接影響到數(shù)控系統(tǒng)的加工精度和速度。而本實驗充分利用實驗室中廢舊的二維工作臺,并進行導(dǎo)軌,絲杠,電機,軸承等選型,在其基礎(chǔ)之上搭建成三維工作臺,實現(xiàn)對插補仿真技術(shù)的應(yīng)用研究,這樣既節(jié)約了成本實現(xiàn)了廢物回收再利用,又兼顧了插補技術(shù)的研究,因此具有十分廣泛而重要的現(xiàn)實意義1.2課題研究的現(xiàn)狀國內(nèi)數(shù)控技術(shù)發(fā)展,1996年,清華大學(xué)研制了PC-DSP主從式控制器,成功應(yīng)用于光驅(qū)高速數(shù)字符伺服控制系統(tǒng);南京四開電子公司與清華大學(xué)共同研制的基于32位CPU和通用計算機主從式SKY數(shù)控系統(tǒng)實現(xiàn)了完全國產(chǎn)化,通過江蘇省科委組織的科技成果鑒定并認為己達到當時國際先進水平。1999年,武漢華中理工大學(xué)利用TMS320F243定點DSP芯片設(shè)計了一款PC-DSP主從式多軸運動控制器,該控制器可以通過CAN總線與CNC系統(tǒng)中的上位PC機及其它一些具有不同功能的硬件模塊進行通訊,在2000年,又研制成功了一種基于TMS320C203的定點DSP的數(shù)值插補和通訊管理控制器。國際數(shù)控系統(tǒng)發(fā)展現(xiàn)狀:在80年代初,隨著計算機控制技術(shù)和先進制造技術(shù)的發(fā)展,基于PC的開放式數(shù)控系統(tǒng)就開始得以在世界范圍內(nèi)推廣。NGC (Next Generation Controller)”研究計劃,首先提出了開放體系結(jié)構(gòu)控制器的概念。自1990年開始,美國的幾個大的科研機構(gòu)對N GC計劃分別發(fā)表了相應(yīng)的研究內(nèi)容。其后由許多相關(guān)的研究計劃在世界各國相繼啟動,其中較有影響的有美國的OMAC、歐洲的OSACa和日本的ONE計劃。同時,發(fā)達國家將DSP運動控制技術(shù)融入了開放式數(shù)控機床的研究。1995年,Matsui, N在常規(guī)DSP速度和位置控制的研究中引入了自適應(yīng)控制、系統(tǒng)參數(shù)在線辯識技術(shù), Kolek, k提出了一種基于總線技術(shù)的浮點DSP控制器,該控制器增強了系統(tǒng)資料計算與處理的速度及控制的精度;1997年,Larsen, G/Cetinkunt在DSP控制器上提出并實現(xiàn)了一種基于小腦模型關(guān)節(jié)控制器的神經(jīng)網(wǎng)絡(luò)自學(xué)習(xí)伺服控制系統(tǒng),以補償鉆石精整加工過程中由于機械軸摩擦力造成的影響:同年,Han, S. H提出一種用于機器人操縱器的實時補償、自適應(yīng)算法的DSP控制器系統(tǒng); 1998年,Style, A. W. /Diana, G.開發(fā)了一種基于Mathworks Simulink/Realtimeworkshop的PC-DSP主從式系統(tǒng),用于運動控制系統(tǒng)的設(shè)計、仿真及實時控制形成了DSP運動控制系統(tǒng)的雛形;1999年,Brandstatter. W.創(chuàng)立了一種基于DSP的用于步進電機控制系統(tǒng)的方法,該系統(tǒng)包含了對PI電流控制和控制策略補償?shù)忍攸c,從而避免電機轉(zhuǎn)速的波動; Moynihan.J. F.將DSP作為專門的運算處理單元,用于計算高精度的位置、速度傳感器的信號,這是DSP在運動控制插補運算功能的典型應(yīng)用。1.3課題研究的主要內(nèi)容作者在實驗期間參考各種資料,完成了對數(shù)控系統(tǒng),伺服系統(tǒng),單片機程序開發(fā)的研究主要有以下幾個方面:(1)在原有的二維工作臺的基礎(chǔ)上通過對步進電機,滾珠絲杠,直 線導(dǎo)軌,深溝球軸承,十字滑塊聯(lián)軸器等的選型搭建一臺在技術(shù)性、經(jīng)濟性和實用性都比較良好三維工作臺。(2)對設(shè)計好的三維數(shù)控工作臺進行proe建模及其運動仿真。(3)借助此三維工作臺研究了插補仿真技術(shù)對數(shù)控工作臺精密度的影響,進行伺服系統(tǒng)的選擇,安裝與調(diào)試,編寫了插補仿真系統(tǒng)軟件上下位機程序。第2章 三維數(shù)控工作臺的硬件選擇及連接結(jié)構(gòu)三維數(shù)控工作臺的整體設(shè)計包括對步進電機,滾珠絲杠,直線導(dǎo)軌,深溝球軸承,十字滑塊聯(lián)軸器的型號選取及其連接結(jié)構(gòu)的確定。2.1三維數(shù)控工作臺的工作原理介紹三維數(shù)控工作臺的主要工作原理簡述如下:(1)在X極方向由步進電機控制聯(lián)軸器進而控制絲杠的轉(zhuǎn)動,絲杠的轉(zhuǎn)動帶動了絲杠螺母座的移動從而也就帶動了固定有Y極的連接板的運動。(2)在Y極方向由步進電機控制聯(lián)軸器進而控制絲杠的轉(zhuǎn)動,絲杠的轉(zhuǎn)動帶動了絲杠螺母座的移動從而也就帶動了固定有Z極的連接板的運動。(3)在Z極方向上由步進電機控制聯(lián)軸器進而控制絲杠的轉(zhuǎn)動,絲杠的轉(zhuǎn)動帶動了螺母座的移動,也就帶動了Z極上連接板的移動,進而完成了三維數(shù)控工作臺的整體移動。2.2三維數(shù)控工作臺的基本結(jié)構(gòu)為保證一定的傳動精度和平穩(wěn)性以及結(jié)構(gòu)的緊湊,采用滾珠絲杠螺母傳動副。為提高傳動剛度和消除間隙,采用有預(yù)加載荷的結(jié)構(gòu)。由于工作臺的運動部件重量和工作載荷不大,故選用滾動直線導(dǎo)軌副,從而減小工作臺的摩擦系數(shù),提高運動平穩(wěn)性??紤]電機步距角和絲杠導(dǎo)程只能按標準選取,為達到分辨率0.01mm的要求,以及考慮步進電機負載匹配,簡化結(jié)構(gòu),聯(lián)軸器將電機與絲杠直接連接。如圖2-1所示為三維數(shù)控工作臺的基本結(jié)構(gòu),根據(jù)所給出的要求所設(shè)計的三維工作臺應(yīng)該滿足行程及精密度要求,同時在運行時還有具有一定的穩(wěn)定性,盡可能的縮小誤差大小,設(shè)計時X軸,Y軸,Z軸采用相同的運動裝置,保證各接觸面精度以保證裝配精度。由于x、y、z各方向的配合面以及裝配關(guān)系直接影響到整體運行的精度,故對各裝配面以及運行部件的接觸表面都要求保持相應(yīng)的精度及定位精度。按上述結(jié)構(gòu)進行組裝就能設(shè)計制造出一臺符合要求,經(jīng)濟實惠,精確度高的三維數(shù)控工作臺。1-直線導(dǎo)軌;2-肋板;3-滾珠絲杠;4-連接板;5-十字滑塊聯(lián)軸器;6-步進電機圖2-1 三維數(shù)控工作臺基本結(jié)構(gòu)2.3步進電機的選擇根據(jù)三維數(shù)控工作臺的工作特性、工作環(huán)境、工作載荷的大小和性質(zhì)等條件,選擇電動機的種類、類型、結(jié)構(gòu)形式、功率和轉(zhuǎn)速,確定出電動機的型號根據(jù)電源種類(直流或交流)、工作條件(環(huán)境、溫度、空間位置等)及載荷性質(zhì)和大小、起動特性和過載情況來選擇。由于一般生產(chǎn)單位多采用三相交流電源,根據(jù)工作臺臺的工作特性,需選用步進電機。步進電機是將電脈沖信號轉(zhuǎn)變?yōu)榻俏灰苹蚓€位移的開環(huán)控制元步進電機件。在非超載的情況下,電機的轉(zhuǎn)速、停止的位置只取決于脈沖信號的頻率和脈沖數(shù),而不受負載變化的影響,當步進驅(qū)動器接收到一個脈沖信號,它就驅(qū)動步進電機按設(shè)定的方向轉(zhuǎn)動一個固定的角度,稱為“步距角”,它的旋轉(zhuǎn)是以固定的角度一步一步運行的??梢酝ㄟ^控制脈沖個數(shù)來控制角位移量,從而達到準確定位的目的;同時可以通過控制脈沖頻率來控制電機轉(zhuǎn)動的速度和加速度,從而達到調(diào)速的目的。主要有反應(yīng)式、永磁式和混合式三大類。在選擇的時候主要根據(jù)以下參數(shù)進行:步距角的選擇:電機的步距角取決于負載精度的要求,將負載的最小分辨率(當量)換算到電機軸上,每個當量電機應(yīng)走多少角度(包括減速)。電機的步距角應(yīng)等于或小于此角度。市場上步進電機的步距角一般有0.36度/0.72度(五相電機)、0.9度/1.8度(二、四相電機)、1.5度/3度 (三相電機)等。靜力矩的選擇:步進電機的動態(tài)力矩一下子很難確定,我們往往先確定電機的靜力矩。靜力矩選擇的依據(jù)是電機工作的負載,而負載可分為慣性負載和摩擦負載二種。單一的慣性負載和單一的摩擦負載是不存在的電流的選擇:靜力矩一樣的電機,由于電流參數(shù)不同,其運行特性差別很大,可依據(jù)矩頻特性曲線圖,判斷電機的電流。根據(jù)以上內(nèi)容,結(jié)合本課題,作者選擇北京時代超群有限公司生產(chǎn)的42HBS33BJ4-TR0型步進電機。具體參數(shù)如表2-1和圖2-2所示:表2-1 北京時代超群有限公司42式步進電機型號參數(shù)表型號相數(shù)步距角靜轉(zhuǎn)距(Nm)電流(A)相電阻()相電感(mH)繞組出軸長(mm)重量42HBS33BJ4-TR031.80.210.428.532串長22200圖2-2 步進電機參數(shù)圖2.4絲杠的選型與校核2.4.1滾珠絲杠的簡單介紹2.4.1.1簡介滾珠絲杠是將回轉(zhuǎn)運動轉(zhuǎn)化為直線運動,或?qū)⒅本€運動轉(zhuǎn)化為回轉(zhuǎn)運動的理想的產(chǎn)品。 滾珠絲杠由螺桿、螺母、鋼球、預(yù)壓片、反向器、防塵器組成。它的功能是將旋轉(zhuǎn)運動轉(zhuǎn)化成直線運動,這是艾克姆螺桿的進一步延伸和發(fā)展,這項發(fā)展的重要意義就是將軸承從滾動動作變成滑動動作。由于具有很小的摩擦阻力,滾珠絲杠被廣泛應(yīng)用于各種工業(yè)設(shè)備和精密儀器。滾珠絲杠是工具機和精密機械上最常使用的傳動元件,其主要功能是將旋轉(zhuǎn)運動轉(zhuǎn)換成線性運動,或?qū)⑴ぞ剞D(zhuǎn)換成軸向反覆作用力,同時兼具高精度、可逆性和高效率的特點。2.4.1.2類型常用的循環(huán)方式有兩種:外循環(huán)和內(nèi)循環(huán)。滾珠在循環(huán)過程中有時與絲杠脫離接觸的稱為外循環(huán);始終與絲杠保持接觸的稱為內(nèi)循環(huán)。滾珠每一個循環(huán)閉路稱為列,每個滾珠循環(huán)閉路內(nèi)所含導(dǎo)程數(shù)稱為圈數(shù)。內(nèi)循環(huán)滾珠絲杠副的每個螺母有2列、3列、4列、5列等幾種,每列只有一圈;外循環(huán)每列有1.5圈、2.5圈和3.5圈等幾種。(1)外循環(huán):外循環(huán)是滾珠在循環(huán)過程結(jié)束后通過螺母外表面的螺旋槽或插管返回絲杠螺母間重新進入循環(huán)。外循環(huán)滾珠絲杠螺母副按滾珠循環(huán)時的返回方式主要有端蓋式、插管式和螺旋槽式。 常用外循環(huán)方式有:端蓋式、插管式、螺旋槽式。端蓋式,在螺母上加工一個縱向孔,作為滾珠的回程通道,螺母兩端的蓋板上開有滾珠的回程口,滾珠由此進入回程管,形成循環(huán)。插管式,它用彎管作為返回管道,這種結(jié)構(gòu)工藝性好,但是由于管道突出螺母體外,徑向尺寸較大。螺旋槽式,它是在螺母外圓上銑出螺旋槽,槽的兩端鉆出通孔并與螺紋滾道相切,形成返回通道,這種結(jié)構(gòu)比插管式結(jié)構(gòu)徑向尺寸小,但制造較復(fù)雜。外循環(huán)滾珠絲杠外循環(huán)結(jié)構(gòu)和制造工藝簡單,使用廣泛。其缺點是滾道接縫處很難做得平滑,影響滾珠滾道的平穩(wěn)性。 (2 內(nèi)循環(huán):所示為內(nèi)循環(huán)滾珠絲杠。內(nèi)循環(huán)均采用反向器實現(xiàn)滾珠循環(huán),反向器有兩種類型。圓柱凸鍵反向器,它的圓柱部分嵌入螺母內(nèi),端部開有反向槽。反向槽靠圓柱外圓面及其上端的圓鍵定位,以保證對準螺紋滾道方向。扁圓鑲塊反向器,反向器為一般圓頭平鍵鑲塊,鑲塊嵌入螺母的切槽中,其端部開有反向槽,用鑲塊的外輪廓定位。兩種反向器比較,后者尺寸較小,從而減小了螺母的徑向尺寸及縮短了軸向尺寸。但這種反向器的外輪廓和螺母上的切槽尺寸精度要求較高。2.4.1.3特點(1)與滑動絲杠副相比驅(qū)動力矩為1/3: 由于滾珠絲杠副的絲杠軸與絲杠螺母之間有很多滾珠在做滾動運動,所以能得到較高的運動效率。與過去的滑動絲杠副相比驅(qū)動力矩達到1/3以下,即達到同樣運動結(jié)果所需的動力為使用滾動絲杠副的1/3。在省電方面很有幫助。 (2)高精度的保證: 滾珠絲杠副是一般是用世界最高水平的機械設(shè)備連貫生產(chǎn)出來的,特別是在研削、組裝、檢查各工序的工廠環(huán)境方面,對溫度、濕度進行了嚴格的控制,由于完善的品質(zhì)管理體制使精度得以充分保證。 (3)微進給可能 滾珠絲杠副由于是利用滾珠運動,所以啟動力矩極小,不會出現(xiàn)滑動運動那樣的爬行現(xiàn)象,能保證實現(xiàn)精確的微進給。(4)無側(cè)隙、剛性高 滾珠絲杠副可以加予壓,由于予壓力可使軸向間隙達到負值,進而得到較高的剛性。2.4.2滾珠絲杠的選型絲杠的選型過程中對于絲杠本身需要注意以下主要參數(shù):1-公稱直徑。即絲杠的外徑,常見規(guī)格有12,14,16,20,25,32,40,50,63,80,100,120.公稱直徑和負載成正比,公稱直徑越大,負載越大,而負載的大小直接影響滾珠絲杠的壽命,實際負荷與額定負荷比值越小,壽命越長。2-導(dǎo)程。也成螺距,即螺桿每旋轉(zhuǎn)一周螺紋上一點所移動的直線距離,常見的導(dǎo)程有1,2,4,6,8,10,12,16,20,25,30。導(dǎo)程與絲杠的直線速度有直接關(guān)系,輸入轉(zhuǎn)速一定的情況下,導(dǎo)程越大速度越快。3-長度。長度主要是只絲杠全長,設(shè)計師主要是根據(jù)工作長度及設(shè)計寬裕量而定的,一般廠家可以對所需絲杠進行切割,從而滿足客戶的要求。4-精度。滾珠絲杠按國家標準可以分為P類和T類,即傳動類和定位類,精度等級有1,2,3,4。國外產(chǎn)品一律以C0-C10來表示,一般來說普通機械一般選擇C7,高精度機械一般選擇C5以上,C3以下,光學(xué)或檢測機構(gòu)一般選擇C3以上,一般機械如本實驗中的三位工作臺,一般推薦為C7即可。根據(jù)以上內(nèi)容初選滾珠絲杠型號為SFUO1204-4的滾珠絲杠,其具體參數(shù)如表2-2和圖2-3所示:表2-2 滾珠絲杠型號參數(shù)表型號dIDaDABLWXHnCaCoaKSFUO1204-41242.524401040324.5304593112912圖2-3 滾珠絲杠型號參數(shù)圖初選X軸,Y軸,Z軸長度為337mm,其中工作長度為300mm。2.4.3滾珠絲杠的校核 絲杠的校核主要是工作載荷校核,剛度驗算,傳動效率的計算。2.4.3.1傳動效率計算滾珠絲杠計算步驟為: (2-1) 代入數(shù)值求得=0.9482符合要求2.4.3.2絲杠最大載荷計算絲杠上的工作載荷為走刀抗力,移動體重力和作用在導(dǎo)軌上的其他切削分力相關(guān)的摩擦力。由于選擇的導(dǎo)軌要求結(jié)構(gòu)簡單,間隙調(diào)整方便,摩損不做太多要求,有良好的可替換性且運動平穩(wěn),故選擇直線滑動導(dǎo)軌配合小壓板來替代有槽的滑動導(dǎo)軌,所以選擇最簡單的導(dǎo)軌塊,直線平導(dǎo)軌的實驗公式進行計算。 (2-2), 將所得數(shù)據(jù)代入上式有 :最大動負載C的計算及主要尺寸:絲杠最大動載荷: (2-3) 由機械設(shè)計手冊可知 (2-4)2.4.3.3剛度驗算 根據(jù)公式 (2-5) 絲杠副剛度的驗算 絲杠總變形量 變形量要少于定位精度得一半,即0.01/2=0.005 =0.0038YE,可用X方向走的總步數(shù)XE作為終點判別的依據(jù),如動點X等于終點XE則停止。當XEYE,則用Y方向走的總步數(shù)YE作為終點判別的依據(jù)。如圖4-1所示對直線上任意一點(x,y),則有直線方程 x/y = xe/ye (4-1)即 xey - xye =0 設(shè)P(x,y)為加工動點,則若P位于該加工直線上,有:xeyi - xiye- = 0若p位于該加工直線上方,有:xeyi - xiye 0若P位于該加工直線下方,有:xeyi - xiye 0由此定義偏差判別函數(shù)Fi為: Fi = xeyi - xiye當Fi = 0時,加工動點在直線上;當FI 0時,加工動點在直線上方;FI 0時,加工動點在直線下方。表1是在各個象限插補技術(shù)公式。直線插補器如圖4-2所示。圖4-1比較法直線插補示意圖表4-1插補計算公式象限坐 標 進 給偏 差 計 算F0F0F0F0+x+yFi+1=Fi-yeFi+1=Fi+x-x+y-x-y+x-y圖4-2直線插補器4.3數(shù)控插補仿真軟件的說明計算機上位機人機交互界面如下圖所示:圖4-3上位機人機交互界面在進行插補實驗時,操作步驟如下:1) 點選直線或圓弧。 2) 輸入直線或圓弧參數(shù)。3) 清屏。4) 開始。即是畫出實驗所需曲線。5) 點選實驗類型。界面的左邊實時顯示插補的路徑,右邊實時的更新插補器里的相關(guān)數(shù)據(jù)。4.4開環(huán)系統(tǒng)控制原理三維數(shù)控工作臺伺服系統(tǒng)控制分兩部分,一是:x-y部分控制,二是:z方向控制,首先通過STC12C5412型單片機控制X軸和Y軸的步進電機,然后通過89C51控制Z軸的單片機。STC12C5412型單片機有兩個PWM波發(fā)出口,可同時發(fā)出兩個脈沖來控制兩個步進電機,發(fā)出的兩個脈沖通過控制器放大信號來控制步進電機。89C51型單片機控制一個步進電機,通過控制器來放大信號達到驅(qū)動步進電機的目的。步進電機是將電脈沖信號轉(zhuǎn)變?yōu)榻俏灰苹蚓€位移的開環(huán)控制元件。在非超載的情況下,電機的轉(zhuǎn)速、 停止的位置只取決于脈沖信號的頻率和脈沖數(shù),而不受負載變化的影響,即給電機加一個脈沖信號,電機 則轉(zhuǎn)過一個步距角。這一線性關(guān)系的存在,加上步進電機只有周期性的誤差而無累積誤差等特點。使得在速度、位置等控制領(lǐng)域用步進電機來控制變的非常的簡單。步進電機的運動特性與配套使用的驅(qū)動電源又密切的關(guān)系。驅(qū)動電源由脈沖分配器、功率放大器等組成。驅(qū)動電源是將變頻信號源送來的脈沖信號及方向信號按要求的配電方式自動的循環(huán)供給電動機各項繞組,以驅(qū)動電動機轉(zhuǎn)子正反轉(zhuǎn)。變頻信號源是可提供從幾赫到幾萬赫的頻率信號連續(xù)可調(diào)的脈沖信號發(fā)生器,只要控制輸入電脈沖的數(shù)量及頻率就可精確控制步進電機的轉(zhuǎn)角及轉(zhuǎn)速。如圖4-4步進電機開環(huán)伺服原理圖。圖4-4步進電機開環(huán)伺服原理圖 開環(huán)控制步驟如下所示: 輸入程序單片機脈沖分配器功率放大步進電機絲杠絲杠螺母及小壓板連接板4.5單片機設(shè)計 如圖4-5,圖4-6所示分別為51單片機硬件控制模塊電路圖和驅(qū)動模塊電路圖:圖4-5 單片機控制模塊電路圖圖4-6 單片機驅(qū)動模塊電路圖如圖4-7所示為STC12C5412單片機控制步進電機的接線圖。圖4-7單片機控制步進電機接線圖設(shè)計程序時,在RAM數(shù)據(jù)區(qū)分別存放終點坐標值XE,YE,動點坐標值X,Y,偏差FM。對8位機,一般可用2字節(jié),而行程較大時則需用3字節(jié)或4字節(jié)才能滿足長度和精度要求。此外,所有的數(shù)據(jù)區(qū)必須進行初始值X、Y向步進電機初態(tài)(控制字)。插補程序所用的內(nèi)存單元如表4-2所示:表4-2 內(nèi)存單元表28H29H2AH2BH2CH70HXEYEXYFM反轉(zhuǎn)電機正反轉(zhuǎn)控制字為:D7, D6,D5,D4,D3,D2,D1,D01D0為X向電機控制位。D0=1運行,D0=0停止;D1=1正轉(zhuǎn),D1=0反轉(zhuǎn)。D3D2為Y向電機控制位。D2=1運行,D2=0停止;D3=1正轉(zhuǎn),D3=0反轉(zhuǎn)。X-Y軸步進電機控制程序:ORG 2000HMAIN:MOV SP, #60HLP4: MOV 28H, #12CH; MOV 29H, #12CH; MOV 2AH, #00H; MOV 2BH, #00H; MOV 2CH, #00H; MOV 70H, #0AHLP3: MOV A, 2EH JB ACC.7, LP1 MOV A, 70H SETB ACC.0 CLR ACC.2 MOV 70H, A LCALL MOTR LCALL DELAY MOV A, 2EH哈爾濱理工大學(xué)學(xué)士學(xué)位論文三維數(shù)控工作臺的設(shè)計與開發(fā)摘要在當前生產(chǎn)中的許多機械設(shè)備中均需要精密定位,而其中的三維精密定位工作臺作為關(guān)鍵部件將直接影響其整機的性能和精度。為保證機器性能,工作臺要在X方向和Y方向?qū)崿F(xiàn)快速準確的定位,并且要求在Z方向能夠?qū)崿F(xiàn)精確調(diào)整和定位,要實現(xiàn)快速和準確定位,必須對工作臺進行改裝,使用步進電機和控制卡。本文設(shè)計的工作臺就是基于單片機控制的三維數(shù)控工作臺。本次研究的課題的主要內(nèi)容包括:充分利用實驗室中廢舊的二維工作臺,通過對硬件諸如直線導(dǎo)軌,深溝球軸承,滾珠絲杠,步進電機等的選擇并對零件的整體連接結(jié)構(gòu)進行設(shè)計從而組裝出一臺可運轉(zhuǎn)的三維工作臺;利用三維建模軟件對所選擇的工作臺的各部分零件進行建模,裝配,并對裝配好的三維工作臺實現(xiàn)運動仿真;利用VB語言對插補程序進行軟件設(shè)計;需要完成對三維工作臺的控制系統(tǒng)的設(shè)計,主要包括對開閉環(huán)的選擇,對80C51單片機功能的充分認識并編寫控制程序,充分理解、學(xué)習(xí)插補技術(shù)在三維數(shù)控工作臺中的應(yīng)用。通過上述研究內(nèi)容,我們可以的到一臺經(jīng)濟,實用,精密度較高的三維數(shù)控工作臺,通過與普通工作臺的比較,我們可以從中得出插補技術(shù)對于數(shù)控工作臺的影響。可以說將插補技術(shù)應(yīng)用到現(xiàn)代數(shù)控加工已經(jīng)是一個不可逆轉(zhuǎn)的趨勢,因此本課題具有很高的研究價值。關(guān)鍵詞 數(shù)控系統(tǒng);三維工作臺;單片機;插補技術(shù)Design and development of 3D NC workbenchAbstractTo study the influence of the parameters of open NC servo feed systems and spatial geometry error on the precision and find methods to realize the high precision control of numerical control (NC) system, the development of the control system of a two-axis NC worktable ,consisting of ball screws and linear roller guides, was presented in this thesis. The system is based on an open architecture PMAC (Programmable multi-Axis controller) motion control card to realize real-time control. Some experiments concerning control test and error measurement and analysis can be carried out on the designed worktable. At first, the configuration of control system of the 3D NC worktable Was proposed ,and its software was developed. Modular software development concept featured the system design, which includes the following modules: machining position and speed sampled display module; file management module; parameters setting module; error diagnosis module; precision analysis module; manual debugging module; machine simulation module; help module.As one of focuses, the error measurement and precision analysis of the worktable were emphasized in the development of the system software. Series of experiments about system control and precision were made on the worktable. The precision characteristics of the half-loop and closed-loop position feedbacks were analyzed. Through comparing the theoretical analysis with the data collected from experiments ,a conclusion has been drawn that the smallest contour error will be got if the two axes have the same servo characteristics. The ball-bar ,which is considered to be more reliable than linearscales in measuring contour error, was used to measure the circular motion of the system. The experiment result showed that the contour error of the system was big .By analysis of the error source based on a mathematical model of the measuring system proposed in this thesis, it was found that it was the installation inclination of linear scales that caused so big error. By compensating the error with the measured result by the ball-bar ,the precision of the control system had been improved.Keywords Numerical Control System;three-dimensional NC workbench;SCM;Interpolation technique;III目錄摘要IAbstractII第1章 緒論11.1課題研究的意義11.2課題研究的現(xiàn)狀11.3課題研究的主要內(nèi)容2第2章 三維數(shù)控工作臺的硬件選擇及連接結(jié)構(gòu)32.1三維數(shù)控工作臺的工作原理介紹32.2三維數(shù)控工作臺的基本結(jié)構(gòu)32.3步進電機的選擇42.4絲杠的選型與校核52.4.1滾珠絲杠的簡單介紹52.4.2滾珠絲杠的選型72.4.3滾珠絲杠的校核82.5直線導(dǎo)軌的選型與計算92.5.1直線導(dǎo)軌的簡單介紹92.5.2直線導(dǎo)軌的選型102.6聯(lián)軸器的選型122.6.1聯(lián)軸器的簡介122.6.2聯(lián)軸器的選型132.7軸承選型142.8本章小結(jié)16第3章 三維數(shù)控工作臺的Pro/E三維建模173.1 Pro/E建模軟件簡介173.2 Pro/E界面介紹173.3零件三維建模實例介紹183.3.1新建文件183.3.2建立拉伸特征193.3.3建立螺旋特征203.3.4建立螺母副特征203.3.5進行顏色和外觀設(shè)計213.4其余零件三維建模圖展示223.5三維數(shù)控工作臺裝配233.6本章小結(jié)25第4章 三維工作臺的軟件及控制系統(tǒng)設(shè)計264.1逐點比較法直線插補的簡介264.2逐點比較法直線插補的計算步驟264.3數(shù)控插補仿真軟件的說明294.4開環(huán)系統(tǒng)控制原理304.5單片機設(shè)計304.6本章小結(jié)35結(jié)論36致謝37參考文獻38附錄一39附錄二492附錄一Mechanical Engineering in the Information AgeIn the early 1980s,engineers thought that massive research would be needed to speed up product development.As it turns out ,less research is actually needed because shortened product development cycles encourage engineers to use available technology.Developing a revolutionary technology for use in a new product is risky and prone to failure .Taking shot steps is a safer and usually more successful approach to product development.Shorter product development cyclys are also beneficial in an engineering world in which both captical and labor are global.People who can design and manufacture various products can be found anywhere in the world,but containing a new idea is hard.Geographic distance is no longer a barrier to others finging out about your development six months into the process.If you are got a short development cycle,the situation is not catastrophic-as long as you maintain your lead,But if you are in the midist of a six-year development process and a competitor gets wind of your work,the project could be in more serious trouble. In one respect, manufacturing could be said to be coming full circle. The first manufacturing was a cottage industry: the designer was also the manufacturing, conceiving and fabricating products one at a time. Eventually, the concept of the interchangeability of parts was developed, production was separated into separated into specialized functions, and identical parts were produced thousands at a time.Today, although the designer and manufacturing may not become one again, the functions are being drawn close in the movement toward an integrated manufacturing system.It is perhaps ironic that, at a time when the market demands a high degree of product diversification, the necessity for increasing productivity and reducing cost is driving manufacturing toward integration into a coherent system, a continuous process in which parts do not spend as much as 95% of production time being moved around or waiting to be worked on.The computer is the key to each of these twin requirements. It is the only tool that can provide the quick reflexes, the flexibility and speed, to meet a diversified market. And it is the only tool that enables the detailed analysis and the accessibility of accurate data necessary for the integration of the manufacturing system.Today, nearly every market is a niche market, because customers are selective. If you ignore the potential for tailoring your product to specific customers needs, you will lose the major part of your market share perhaps all of it. Since these niche markets are transient, your company needs to be in a position to respond to them quickly.The emergence of niche markets and design on demand has altered the way engineers conduct research. Today, research is commonly directed toward solving particular problems. Although this situation is probably temporary, much uncommitted technology, developed at government expense or written off by major corporations, is available today at very low cost. Following modest modifications, such technology can often be used directly in product development, which allows many organizations to avoid the expense of an extensive research effort. Once the technology is free of major obstacles, the research effort can focus on overcoming the barriers to commercialization rather than on pursuing new and interesting, but undefined, alternatives.When viewed in this perspective, engineering research must focus primarily on removing the barriers to rapid commercialization of known technologies. Much of this effort must address quality and reliability concerns, which are foremost in the minds of today consumers. Clearly, a reputation for poor quality is synonymous with bad business. Everything possibleincluding thorough inspection at the end of the manufacturing line and automatic replacement of defective productsmust be done to assure that the customer receives a properly functioning product.Research has to focus on the cost benefit of factors such as reliability. As reliability increase, manufacturing costs and the final cost of the system will decrease. Having 30 percent junk at the end of a production line not only costs a fortune but also creates an opportunity for a competitor to take your idea and sell it to your customers.Central to the process of improving reliability and lowering costs is the intensive and widespread use of design software, witch allows engineers to speed up every stage of the design process. Shortening each stage, however, may not sufficiently reduce the time required for the entire process. Therefore, attention must also be devoted to concurrent engineering software with shared databases that can be accessed by all members of the design team.As we move more fully into the information Age, success will require that the engineer process some unique knowledge of and experience in both the development and the management of technology. Success will require broad knowledge and skills as well as expertise in some key social and economic factors at work in the marketplace. Increasingly, in the future, routine problems will not justify heavy engineering expenditures, and engineers will be expected to work cooperatively in solving more challenging, more demanding problems in substantially less time. We have begun a new phase in the practice of engineering. It offers great promise and excitement as more and more problem-solving capability is placed in the hands of the computerized and unquenched thirst for better products and systems must be matched by the joy of creation that marks all great engineering endeavors. Mechanical engineering is a great profession, and it will become even greater as we make the most of the opportunities offered by the Information Age.It may well be that, in the future, the computer may be essential to a companys survival. Many of todays businesses will fade away to be replaced by more productive combinations. Such more-productive combinations are super quality, super productivity plants. The goal is to design and operate a plant that would produce 100% satisfactory parts with good productivity.A sophisticated, competitive world is requiring that manufacturing begin to settle for more, to become itself sophisticated. To meet competition, for example, a company will have to meet the somewhat conflicting demands for greater product diversification, higher quality, improved productivity, and low prices.The company that seeks to meet these demands will need a sophisticated tool, one that will allow it to respond quickly to customer needs while getting the most out of its manufacturing resources.The computer is that tool.Becoming a “super quality, super productivity” plant requires the integration of an extremely complex system. This can be accomplished only when all elements of manufacturing-design, fabrication and assembly,quality assurance, management, materials handlingare computer integrated.In product design, for example, interactive computer-aided-design (CAD) systems allow the drawing and analysis tasks to be performed in a fraction of the time previously required and with greater accuracy. And programs for prototype testing and evaluation further speed the design process.In manufacturing planning, computer-aided process planning permits the selection, from thousands of possible sequences and schedules, of the optimum process.On the shop floor, distributed intelligence in the form of microprocessors controlled machines, runs automated loading and unloading equipment, and collects data on current shop conditions.But such isolated revolutions are not enough. What is needed is a totally automated system, linked by common software from front door to back.The benefits range throughout the system. Essentially, computer integration provides widely and instantaneously available, accurate information, improving communication between departments, permitting tighter control, and generally enhancing the overall quality and efficiency of the entire system.Improved communication can mean, for example, designs that are more producible. The NC programmer and the tool designer have a chance to influence the product designer, and vice versa.Engineering changes, thus, can be reduced, and those that are required can be handled more efficiently. Not only dose the computer permit them to be specified more quickly, but it also alerts subsequent users of the data to the fact that a change has been made.The instantaneous updating of production-control data permits better planning and more effective scheduling. Expensive equipment, therefore, is used more productively, and parts move more efficiently through production, reducing work-in-process costs.Product quality, too, can be improved. Not only are more-accurate designs produced, for example, but the use of design data by the quality-assurance department helps eliminate errors due to misunderstandings.People are enabled to do their jobs better. By eliminating tedious calculations and paperworknot to mention time wasted searching for informationthe computer not only allows workers to be more productive but also frees then to do what only human beings can do: think creatively.Computer integration may also lure new people into manufacturing. People are attracted because they want to work in a modern, technologically sophisticated environment.In manufacturing engineering, CAD/CAM decreases tool design, NC-programming, and planning times while speeding the response rate, which will eventually permit in-house staff to perform work that is currently being contracted out.Computers have been used in nearly every manufacturing job. Computers improve the efficiency, accuracy, and productivity of many manufacturing processes. Just like the other tools and machines, computers extend human capabilities and make some jobs easier. Every department in manufacturing has found a use for computers.In the management department, supervisors and managers use computers to gather information about the progress of work in all the other departments. In marketing, researchers, advertisers, and sales people use computers to get data on potential buyers, to study market research, and to create advertisements.As we move more fully into the Information Age,success will require that the engineer possess some unique knowledge of and experience in both the development and the management of technology.Success will require broad knowledge and skills as well as expertise in some key technologies and disciplines;it will also require a keen awareness of the social and economica factors at work in the marketplace.Increasingly,in the future,routine problems will not justify heavy engineering expenditures,and engineers will be expected to work cooperatively in solving more challenging,more demanding problems in substantially less time.It offers great promise and excitement as more and more problem-solving capability is placed in the hands of the computerized and wired engineer.We have begun a new phase in the practice of engineering.Mechanical engineering is a great profession,ang it will become even greater as we make the most of the opportunities offered by the Information Age.信息時代的機械工程在80年代初工程師們曾經(jīng)認為要加快產(chǎn)品的研制開發(fā),必須進行大量的研究工作。結(jié)果是實際上只進行了較少的見就工作,這是因為產(chǎn)品開發(fā)周期的縮短,促使工程師們盡可能地利用現(xiàn)有的技術(shù)。研制開發(fā)一種創(chuàng)新行得技術(shù)并將其應(yīng)用在新產(chǎn)品上,是有風(fēng)險的,并且易于招致失敗。在產(chǎn)品開發(fā)過程中采用較少的步驟是一種安全的和易于成功的方法。對于資金和人力都處于全球性環(huán)境中的工程界而言,縮短產(chǎn)品研制開發(fā)周期也是有益的。能夠設(shè)計和制造各種產(chǎn)品的人可以在世界各地找到。但是,具有創(chuàng)新思想的人則比較難找。對于你已經(jīng)進行了6個月的研制開發(fā)工作,地理上的距離已經(jīng)不再是其他人發(fā)現(xiàn)他的障礙。如果你的研制周期較短,只要你仍然保持領(lǐng)先,這種情況并不會造成嚴重后果。但如果你正處于一個長達6年的研制開發(fā)過程的中期,一個競爭對手了解到你的研究工作的一些信息,這個項目將面臨比較大的麻煩。從某一方面可以說,制造業(yè)正在完成一個循環(huán)。最初的制造業(yè)是家庭手工業(yè):設(shè)計者本身也是制造者,產(chǎn)品的構(gòu)思和加工由同一個人來完成。后來,形成了零件的互換性這個概念,生產(chǎn)被依照專業(yè)功能分割開來,可以成批地生產(chǎn)數(shù)以千計的相同零件。今天,盡管設(shè)計者與制造者不可能再是同一個人,但在向集成制造系統(tǒng)前進的途中,這兩種功能已經(jīng)越來越靠近了。可能具有諷刺意味的是,在市場需求高度多樣化產(chǎn)品的時候,提高生產(chǎn)率和降低成本的必要性促使制造業(yè)朝著集成為單調(diào)關(guān)聯(lián)系統(tǒng)方向變化。這是一個連續(xù)的過程,在其中零件不需要花費多達95%的生產(chǎn)時間用在運輸和等待加工上。計算機是滿足這兩項要求中的任何一項的關(guān)鍵。它是能夠提供快速反應(yīng)能力、柔性和滿足多樣化市場的唯一工具。而且,它是實現(xiàn)制造系統(tǒng)集成所需要的、能夠進行詳細分析和利用精確數(shù)據(jù)的唯一工具。將來,計算機可能是一個企業(yè)生存的基本條件,許多現(xiàn)今的獎杯生產(chǎn)能力更高的企業(yè)組合所取代。這些生產(chǎn)能力更高的企業(yè)組合是一些具有非常高的質(zhì)量、非常高的生產(chǎn)率的工廠。目標是的設(shè)計和運行一個能以高生產(chǎn)率的方式生產(chǎn)100%合格產(chǎn)品的工廠。一個采用先進技術(shù)的、競爭的世界正在促進制造業(yè)開始做更多的工作,使其本身采用先進的技術(shù)。為了適應(yīng)競爭,一個公司會滿足一些在某種程度上相互矛盾的要求,諸如產(chǎn)品多樣化、提高質(zhì)量、增加生產(chǎn)率、降低價格。在努力滿足這些要求的過程中,公司需要一個采用先進技術(shù)的工具,一個能夠?qū)︻櫩偷男枨笞龀隹焖俜磻?yīng),而且從制造資源中獲得最大收益的工具。計算機就是這個工具。成為一個具有“非常高的質(zhì)量、非常高的生產(chǎn)率”的工廠,需要對一個非常復(fù)雜的系統(tǒng)進行集成。這只是通過采用計算機對機械制造的所有組成部分設(shè)計、加工、裝配、質(zhì)量保證、管理和材料裝卸及輸送進行集成才能完成。例如,在產(chǎn)品設(shè)計期間,交互式的計算機輔助設(shè)計系統(tǒng)使得完成繪圖和和分析工作所需要的時間比原來減少,而且精確程度得到了很大的提高。此外,樣機的實驗與評價程序進一步加快了設(shè)計進程。 在制定制造計劃時,計算機輔助編制工藝規(guī)程可以從數(shù)以千計的工序和加工過程中選擇最好的加工方案。在車間里,分布式智能以微機處理器這種方式來控制機床、從總自動裝卸設(shè)備和收集關(guān)于當前車間狀態(tài)的信息。但是這些各自獨立的改革還遠遠不夠。我沒所需要的是由一個通用軟件從始端到終端進行控制的全部自動化的系統(tǒng)。整個系統(tǒng)都會從中受益?;旧希嬎銠C集成可以提供廣泛的、及時地和精確度的信息,可以改進各部門之間的交流與溝通,實施更嚴格的控制,而且通常能夠增強整個系統(tǒng)的全面質(zhì)量和效率。例如,改進交流和溝通意味著會使設(shè)計具有更好的可制造性。數(shù)控編程人員和工藝裝配設(shè)計人員有機會向產(chǎn)品設(shè)計人員提出意見,反之亦然。因而可以減少技術(shù)方面的變更,而對于那些必要的變更,可以更有效地進行處理。計算機不僅能夠更快地對變更之處做出詳細的說明,而且還能夠把變更之后的數(shù)據(jù)告訴隨后的使用者。利用及時更新的生產(chǎn)控制數(shù)據(jù)可以制定更好的工藝規(guī)程和更有效率的生產(chǎn)進度。因而,可使昂貴的設(shè)備得到更好的利用,提高零件在生產(chǎn)過程中的運送效率,減少在制品的成本。產(chǎn)品質(zhì)量也可得到改進。例如,不僅可以提高設(shè)計精度,還可以是質(zhì)量保證部門利用設(shè)計數(shù)據(jù),避免由于誤解而產(chǎn)生錯誤。可使人們更好的完成他們的工作。通過避免冗長的計算和書寫工作這還不算查找資料所浪費的時間計算機不僅使人們更有效的工作,而且還能把他們解放出來去做只有人類才能做的工作:創(chuàng)造性的思考計算機集成制造還會吸引新的人才進入制造業(yè)。人才被吸引過來的原因是他們希望到一個現(xiàn)代化的、技術(shù)先進的環(huán)境中工作。在制造工程中,CAD/CAM減少了工藝裝備設(shè)計、數(shù)控編程和編制工藝規(guī)程所需要的時間。同時加快了響應(yīng)速度,這最終將會使目前外圍加工的工作由公司內(nèi)部人員來完成。今天,因為顧客們有較大的選擇余地,幾乎所有市場都是特殊定向產(chǎn)品市場。如果你不能使你的產(chǎn)品滿足某些特定客戶的要求,你將失掉你的市場份額中的一大部分,或者失掉全部份額。由于這些定向產(chǎn)品市場是經(jīng)常變化的,你的公司應(yīng)該對市場的變化做出快速的反應(yīng)。定向產(chǎn)品市場和根據(jù)客戶要求進行設(shè)計這種現(xiàn)象的出現(xiàn)改變了工程師的研究工作的方式。今天,研究工作通常是針對解決特定問題進行的 ?,F(xiàn)在許多由政府資助或者由大公司出資開發(fā)的技術(shù)可以在非常低的成本下被自由使用,盡管這種情況可能是暫時的。在對這些技術(shù)進行適當改進后,他們通常能夠被直接用于產(chǎn)品開發(fā),這使得許多公司可以節(jié)省昂貴的研究經(jīng)費。在主要的技術(shù)障礙被克服后,研究工作應(yīng)該主要致力于產(chǎn)品的商品化方面,而不是開發(fā)新的、有趣的、不確定的替代產(chǎn)品。采用上述觀點看問題,工程研究應(yīng)該致力于消除將已知技術(shù)快速商品化的障礙。工作的重點是產(chǎn)品的可靠性,這些在當今顧客的頭腦中是最重要的。很明顯,一個質(zhì)量差的聲譽是一個不好企業(yè)的代名詞。企業(yè)應(yīng)該盡最大努力來保證顧客得到合格的產(chǎn)品,這個努力包括在生產(chǎn)線的終端對產(chǎn)品進行嚴格的檢驗和自動更換有缺陷的產(chǎn)品。研究工作應(yīng)該著重考慮諸如可靠性等因素對成本帶來的益處。當可靠性提高時,制造成本和系統(tǒng)的最終成本將會降低。如果在生產(chǎn)線的終端產(chǎn)生了30%的廢品,這不僅會浪費金錢,也會給你的競爭對手創(chuàng)造一個利用你的想法制造產(chǎn)品,并將其銷售給你的客戶的良機。提高可靠性和降低成本這個過程的關(guān)鍵是深入、廣泛地利用設(shè)計軟件。設(shè)計軟件可以使工程師們加快每一階段的設(shè)計工作。然而,僅僅縮短每一階段的設(shè)計時間,可能不會顯著地縮短整個設(shè)計過程的時間。因而,必須致力于采用并行工程軟件,這樣可以使所有設(shè)計組的成員都能使用共今天,因為顧客們有較大的選擇余地,幾乎所有市場都是特殊定向產(chǎn)品市場。如果你不能使你的產(chǎn)品滿足某些特定客戶的要求,你將失掉你的市場份額中的一大部分,或者失掉全部份額。由于這些定向產(chǎn)品市場是經(jīng)常變化的,你的公司應(yīng)該對市場的變化做出快速的反應(yīng)。根據(jù)工具與制造工程師手冊,工藝設(shè)計就是系統(tǒng)地確定能夠經(jīng)濟的和有競爭力的將產(chǎn)品制造出來的方法。它主要由選擇、計算和建立工藝文件組成。對加工方法、機床、刀具、工序和順序必須進行選擇。對于一些參數(shù)如進給量、速度、公差、尺寸和成本等應(yīng)該進行計算。最后,應(yīng)該建立加工說明、帶工序簡圖的工藝過程卡和加工路線等方面的工藝文件。工藝設(shè)計是產(chǎn)品設(shè)計和制造的中間環(huán)節(jié)。那么,它是如何將設(shè)計與制造連接起來的呢?大部分制造工程師都會同意這個看法,即如果10個不同的工藝人員進行同一個零件的工藝設(shè)計,他們很可能得出10種不同的方案。顯然,所有這些方案都不能反映最適當?shù)闹圃旆椒ǎ遥聦嵣弦膊荒鼙WC它們中的任何一個方案是由加工這個零件的最好的方法組成的。隨著我們步入信息時代,要取得成功,工程師們在技術(shù)開發(fā)和技術(shù)管理方面都應(yīng)該具有一些獨特的知識和經(jīng)驗。成功的工程師們不但應(yīng)該具有寬廣的知識和技能,而且還應(yīng)該是某些關(guān)鍵技術(shù)或?qū)W科的專家,他們還應(yīng)該在社會因素和經(jīng)濟因素對市場影響方面有敏銳洞察能力。將來,花在解決日常工程問題上的費用將會減少,工程師們將會在一些更富有挑戰(zhàn)行,更急需解決的問題上協(xié)同工作,大大縮短解決這些問題所需要的時間。計算機和網(wǎng)絡(luò)使工程師們具有了越來越多的解決問題的能力,這也給他們的工作帶來很大的希望和喜悅。我們已經(jīng)開始了工程實踐的新階段。機械工程是一個偉大的行業(yè),當我們充分利用了信息時代所提供的及預(yù)后,他將變得更加偉大。
收藏