XK5040數(shù)控銑床主軸箱、進(jìn)給機(jī)構(gòu)及控制系統(tǒng)設(shè)計(jì)【說明書+CAD】
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畢業(yè)設(shè)計(jì)(論文)
題 目 XK5040數(shù)控銑床主軸箱、進(jìn)給機(jī)構(gòu)及控制系統(tǒng)設(shè)計(jì)
學(xué)院名稱 機(jī)械工程學(xué)院
指導(dǎo)教師 顏竟成
職 稱 教授
班 級 機(jī)械設(shè)計(jì)制造及自動(dòng)化 機(jī)械052班
學(xué) 號 20054410225
學(xué)生姓名 何文兵
2009年6月1日
南 華 大 學(xué)
畢業(yè)設(shè)計(jì)(論文)任務(wù)書
學(xué) 院： 機(jī)械工程學(xué)院
題 目： XK5040數(shù)控銑床主軸箱、進(jìn)給機(jī)構(gòu)及控制系統(tǒng)設(shè)計(jì)
起止時(shí)間： 2008年 12 月 9日至 2009年 6月 1日
學(xué) 生 姓 名： 何文兵
專 業(yè) 班 級： 機(jī)械設(shè)計(jì)制造及其自動(dòng)化052班
指 導(dǎo) 老 師：
教研室主任：
院 長：
2008年12月29日
南華大學(xué)本科生畢業(yè)設(shè)計(jì)任務(wù)書
（一） 題目：XK5040數(shù)控銑床主軸箱、進(jìn)給機(jī)構(gòu)及控制系統(tǒng)設(shè)計(jì)
給出條件：1、主運(yùn)動(dòng)部分：Z=18級
2、進(jìn)給運(yùn)動(dòng)部分：橫向、縱向脈沖當(dāng)量0.01mm
（二） 設(shè)計(jì)內(nèi)容
１、調(diào)查分析XK5040數(shù)控立式銑床的加工特點(diǎn)，確定新設(shè)計(jì)數(shù)控立式銑床的主要技術(shù)參數(shù)。
?。?、進(jìn)行數(shù)控立式銑床的總體方案設(shè)計(jì)。
?。?、完成住運(yùn)動(dòng)和進(jìn)給的機(jī)械結(jié)構(gòu)設(shè)計(jì)。
?。?、完成控制系統(tǒng)硬件設(shè)計(jì)。
（三） 任務(wù)和要求：
１、根據(jù)總體設(shè)計(jì)方案，繪制XK5040數(shù)控立式銑床總體外觀圖一張。
２、進(jìn)行主運(yùn)動(dòng)的運(yùn)動(dòng)、強(qiáng)度和動(dòng)力計(jì)算，繪制主軸箱部件展開圖一張（A0計(jì)算機(jī)圖一張）。
３、進(jìn)行進(jìn)給運(yùn)動(dòng)的運(yùn)動(dòng)和強(qiáng)度計(jì)算，繪制出縱向數(shù)控進(jìn)給和垂直進(jìn)給機(jī)構(gòu)部裝圖A0一張（A0計(jì)算機(jī)圖）。
４、繪制數(shù)控銑床主軸零件圖一張（A1手工圖）。
５、根據(jù)控制系統(tǒng)總體設(shè)計(jì)方案，繪制控制系統(tǒng)電路圖一張（A0或A1計(jì)算機(jī)圖）（由指導(dǎo)老師確定）。
6、科技譯文（不少于3000漢字，原文可自選或由指導(dǎo)教師提供）。
7、編寫畢業(yè)設(shè)計(jì)說明書一套（不少于二萬字，有英文摘要，全部用計(jì)算機(jī)打出）。
（四） 主要參考資料：
1、《機(jī)械設(shè)計(jì)手冊》，機(jī)械工業(yè)出版社。
2、《實(shí)用機(jī)床設(shè)計(jì)手冊》，遼寧科技出版社。
3、《機(jī)床設(shè)計(jì)圖冊》，上?？萍汲霭嫔?。
4、《TLT集成電路手冊》。
5、《存儲器手冊》。
6、《機(jī)床主軸變速箱設(shè)計(jì)指導(dǎo)》，機(jī)械工業(yè)出版社。
7、《機(jī)床數(shù)控系統(tǒng)設(shè)計(jì)指導(dǎo)書》，中國科技出版社。
8、《數(shù)控機(jī)床系統(tǒng)設(shè)計(jì)》，文懷興編著，化學(xué)工業(yè)出版社。
9、《數(shù)控銑床設(shè)計(jì)》，文懷興主編，化學(xué)工業(yè)出版社。
10、《機(jī)電綜合設(shè)計(jì)指導(dǎo)書》，中國人民大學(xué)出版社。
簽名：
年 月 日
南華大學(xué)本科生畢業(yè)設(shè)計(jì)（論文）開題報(bào)告
設(shè)計(jì)（論文）題目
XK5040數(shù)控銑床主軸箱、進(jìn)給機(jī)構(gòu)及控制系統(tǒng)設(shè)計(jì)
設(shè)計(jì)（論文）題目來源
自選
設(shè)計(jì)（論文）題目類型
工程設(shè)計(jì)類
起止時(shí)間
2008年12月29日至
2009年6月1日
一、設(shè)計(jì)（論文）依據(jù)及研究意義：
數(shù)控機(jī)床即數(shù)字程序控制機(jī)床，是自動(dòng)化機(jī)床的一種。最早出現(xiàn)的是數(shù)控銑床。60年代以后，點(diǎn)位控制的機(jī)床迅速發(fā)展，出現(xiàn)了數(shù)控鉆床、數(shù)控沖床和數(shù)控坐標(biāo)鏜床。這類機(jī)床不需要復(fù)雜的控制算法就可以實(shí)現(xiàn)加工。數(shù)控機(jī)床是現(xiàn)代制造業(yè)的關(guān)鍵設(shè)備，一個(gè)國家數(shù)控機(jī)床的產(chǎn)量和技術(shù)水平在某種程度上就代表這個(gè)國家的制造業(yè)水平和競爭力。近年來，我國數(shù)控機(jī)床的產(chǎn)量持續(xù)增長，數(shù)控化率也顯著提高。另一方面我國數(shù)控產(chǎn)品的技術(shù)水平和質(zhì)量也不斷提高。目前我國一部分普及型數(shù)控機(jī)床的生產(chǎn)已經(jīng)形成一定規(guī)模，產(chǎn)品技術(shù)性能指標(biāo)較為成熟，價(jià)格合理，在國際市場上具有一定的競爭力?！〉呛桶l(fā)達(dá)國家相比，我國數(shù)控機(jī)床行業(yè)在信息化技術(shù)應(yīng)用上仍然存在很多不足。數(shù)控機(jī)床是一種加工效率高、集成度高、用途廣泛的機(jī)床，現(xiàn)已廣泛應(yīng)用于各個(gè)領(lǐng)域。本次設(shè)計(jì)我選擇XK5040數(shù)控立式銑床設(shè)計(jì)及控制系統(tǒng)設(shè)計(jì)。對XK5040數(shù)控立式銑床的主運(yùn)動(dòng)系統(tǒng)和進(jìn)給系統(tǒng)的機(jī)械結(jié)構(gòu)進(jìn)行了設(shè)計(jì)和計(jì)算，并對其控制系統(tǒng)的硬件電路進(jìn)行了設(shè)計(jì)。
二、設(shè)計(jì)（論文）主要研究的內(nèi)容、預(yù)期目標(biāo)：（技術(shù)方案、路線）
主要研究的內(nèi)容：
1. 根據(jù)給出的技術(shù)要求和傳動(dòng)比，推導(dǎo)出轉(zhuǎn)速圖，并根據(jù)轉(zhuǎn)速圖設(shè)計(jì)各軸和齒輪；
2. 進(jìn)行脈沖當(dāng)量和進(jìn)給力的計(jì)算，設(shè)計(jì)進(jìn)給系統(tǒng)；
3. 控制系統(tǒng)的設(shè)計(jì)
技術(shù)路線：
1. 根據(jù)任務(wù)書上要求，搜集資料，對設(shè)計(jì)形成一個(gè)系統(tǒng)的、全局的認(rèn)識，找到設(shè)計(jì)切入點(diǎn)，確定設(shè)計(jì)路線：首先以傳統(tǒng)設(shè)計(jì)開始——根據(jù)現(xiàn)狀和已知條件進(jìn)行改進(jìn)設(shè)計(jì)——設(shè)計(jì)計(jì)算各齒輪和軸——驗(yàn)算和校核。
2. 齒輪幾何尺寸的設(shè)計(jì)；
3. 繪制全部的零件圖及其裝配圖；
三、設(shè)計(jì)（論文）的研究重點(diǎn)及難點(diǎn)：
1. 各齒輪齒數(shù)模數(shù)的確定；
2. 齒輪在各軸上的分布和主軸箱裝配圖的繪制；
3. 滾珠絲桿的設(shè)計(jì)；
4. 控制部分的設(shè)計(jì)。
四、設(shè)計(jì)（論文）研究方法及步驟（進(jìn)度安排）：
2008.12.29～2009.1.15日：參考有關(guān)書籍及外文資料，確定設(shè)計(jì)的總體方案。
1.16 ～2.5日：學(xué)習(xí)CAD 、CAXA、solidworks等軟件的用法，達(dá)到能上手的目的；
2.6～2.25日：收集相關(guān)設(shè)計(jì)資料，根據(jù)前面所學(xué)完成主軸箱的初步設(shè)計(jì)，經(jīng)檢驗(yàn)后完成最終設(shè)計(jì)；
2.26～3.19日：繪制主軸箱裝配圖草圖；
3.20～5.4日：用 CAD繪制全部的零件圖及其裝配圖；
5.5 ～6.1日：編寫說明書、整理資料、備答辯。
五、進(jìn)行設(shè)計(jì)（論文）所需條件：
1. 本項(xiàng)目有目前相對成熟的數(shù)控技術(shù)和實(shí)例支持；
2. 南華大學(xué)機(jī)械工程學(xué)院具有易普機(jī)械設(shè)計(jì)專家、機(jī)械設(shè)計(jì)手冊、MATLAB、SolidWorks、CAXA等先進(jìn)的應(yīng)用軟件；
3. 本項(xiàng)目實(shí)現(xiàn)預(yù)期目標(biāo)的軟、硬件基礎(chǔ)條件已經(jīng)具備。
六、指導(dǎo)教師意見：
簽名：
年 月 日
摘 要
數(shù)控機(jī)床即數(shù)字程序控制機(jī)床，是一種自動(dòng)化機(jī)床，數(shù)控技術(shù)是數(shù)控機(jī)床研究的核心，是制造業(yè)實(shí)現(xiàn)自動(dòng)化、網(wǎng)絡(luò)化、柔性化、集成化的基礎(chǔ)。隨著制造技術(shù)的發(fā)展，現(xiàn)代數(shù)控機(jī)床借助現(xiàn)代設(shè)計(jì)技術(shù)、工序集約化和新的功能部件使機(jī)床的加工范圍、動(dòng)態(tài)性能、加工精度和可靠性有了極大的提高。
本文主要對XK5040數(shù)控立式銑床及控制系統(tǒng)進(jìn)行設(shè)計(jì)，首先分析立式銑床的加工特點(diǎn)和加工要求確定其主參數(shù)，包括運(yùn)動(dòng)和動(dòng)力參數(shù)；根據(jù)主參數(shù)和設(shè)計(jì)要求進(jìn)行主運(yùn)動(dòng)系統(tǒng)、進(jìn)給系統(tǒng)和控制系統(tǒng)硬件電路設(shè)計(jì)。主要進(jìn)行主運(yùn)動(dòng)系統(tǒng)和進(jìn)給系統(tǒng)的機(jī)械結(jié)構(gòu)設(shè)計(jì)及滾珠絲杠和步進(jìn)電機(jī)的選型和校核；對于控制系統(tǒng)由于這里主要針對經(jīng)濟(jì)型數(shù)控銑床的設(shè)計(jì)，這里采用步進(jìn)電機(jī)開環(huán)控制，計(jì)算機(jī)系統(tǒng)采用高性能價(jià)格比的MCS-51系列單片擴(kuò)展系統(tǒng)，主要進(jìn)行中央處理單元的選擇、存儲器擴(kuò)展和接口電路設(shè)計(jì)。
關(guān)鍵詞 數(shù)控技術(shù)；立式銑床；設(shè)計(jì)
ABSTRACT
The numerical control engine bed is the digital process control engine bed, is one kind of automated engine bed, the numerical control technology is the core which the numerical control engine bed studies, is the manufacturing industry realization automation, the network, the flexibility, the integrated foundation. Along with the manufacture technology development, the modern numerical control engine bed with the aid of the modern design technology, the working procedure intensification and the new function part caused the engine bed the processing scope, the dynamic performance, the processing precision and the reliability had the enormous enhancement .
This article mainly carries on the design to the XK5040 numerical control vertical milling machine and the control system, first analyzes the vertical milling machine the processing characteristic and the processing request determines its host parameter, including movement and dynamic parameter; Carry on the host kinematic scheme according to the host parameter and the design request, enters for the system and the control system hardware circuit design. Mainly carries on the host kinematic scheme and enters for the system mechanism design and the ball bearing guide screw and electric stepping motor shaping and the examination; Regarding control system because here mainly aims at the economy numerical control milling machine the design, here uses electric stepping motor open-loop control, the computer system uses the high performance price compared to the MCS-51 series monolithic expansion system, mainly carries on the central processing element the choice, the memory expansion and the connection circuit design .
Key words Numerical control technology; Vertical milling machine; Design
目 錄
引言 1
第一章 總體設(shè)計(jì) 2
1.1、銑床簡介 2
1.2、XK5040型數(shù)控銑床的主要技術(shù)參數(shù)及總傳動(dòng)圖 3
1.2.1 XK5040型數(shù)控銑床的主要技術(shù)參數(shù) 3
1.2.2 總傳動(dòng)系統(tǒng)圖 4
第二章 主運(yùn)動(dòng)系統(tǒng)設(shè)計(jì) 6
2.1 傳動(dòng)系統(tǒng)設(shè)計(jì) 6
2.1.1參數(shù)的擬定 6
2.1.2 傳動(dòng)結(jié)構(gòu)或結(jié)構(gòu)網(wǎng)的選擇 6
2.1.3 轉(zhuǎn)速圖擬定 8
2.1.4齒輪齒數(shù)的確定及傳動(dòng)系統(tǒng)圖的繪制 11
２.２ 傳動(dòng)件的估算與驗(yàn)算 15
2.2.1傳動(dòng)軸的估算和驗(yàn)算 15
２.２.２齒輪模數(shù)的估算 18
２.３ 展開圖設(shè)計(jì) 23
２.３.１結(jié)構(gòu)實(shí)際的內(nèi)容及技術(shù)要求 23
２.３.２ 齒輪塊的設(shè)計(jì) 25
２.３.３ 傳動(dòng)軸設(shè)計(jì) 27
２.３.４ 主軸組件設(shè)計(jì) 30
２.４ 制動(dòng)器設(shè)計(jì) 36
２.４.１ 按扭矩選擇 37
２.５ 截面圖設(shè)計(jì) 38
２.５.１ 軸的空間布置 38
２.５.２ 操縱機(jī)構(gòu) 39
２.５.３ 潤滑 39
２.５.４箱體設(shè)計(jì)的確有關(guān)問題 40
第三章 進(jìn)給系統(tǒng)設(shè)計(jì) 42
３.１ 總體方案設(shè)計(jì) 42
３.１.１對進(jìn)給伺服系統(tǒng)的基本要求 42
３.１.２進(jìn)給伺服系統(tǒng)的設(shè)計(jì)要求 42
３.１.３總體方案 43
３.２ 進(jìn)給伺服系統(tǒng)機(jī)械部分設(shè)計(jì) 44
３.２.１確定脈沖當(dāng)量，計(jì)算切削力 44
３.２.２滾珠絲桿螺母副的計(jì)算和造型 46
３.２.３齒輪傳動(dòng)比計(jì)算 55
３.２.４ 步進(jìn)電機(jī)的計(jì)算和選型 57
３.２.５ 進(jìn)給伺服系統(tǒng)機(jī)械部分結(jié)構(gòu)設(shè)計(jì) 65
參考文獻(xiàn) 70
致謝 71
iv
The open system merit of Computer Numerical Control
The open system merit is the system simple, the cost low, but the shortcoming is the precision is low. The reverse gap, the guide screw pitch error, stop inferiorly can affect the pointing accuracy by mistake. Following several kind of improvements measure may cause the pointing accuracy distinct improvement.
1. reverse gap error compensates
The numerical control engine bed processing cutting tool and the work piece relative motion is depends upon the drive impetus gear,the guide screw rotation, thus the impetus work floor and so on moves the part to produce moves realizes. As traditional part gear, guide screw although the manufacture precision is very high, but always unavoidably has the gap. As a result of this kind of gap existence, when movement direction change, starts the section time to be able to cause inevitably actuates the part wasting time, appears the instruction pulse to push the motionless functional element the aspect. This has affected the engine bed processing precision, namely the instruction pulse and actual enters for the step does not tally,has the processing error therefore, the split-ring numerical control system all establishes generally has the reverse gap error compensatory function, with by makes up which wastes time the step reverse gap difference compensates is first actual reverse enters for the error, converts the pulse equivalent number it, compensates the subroutine as the gap the output, when the computer judgment appears when instruction for counter motion, transfers the gap to compensate the subroutine immediately, compensates the pulse after the output to eliminate the reverse gap to carry on again normally inserts makes up the movement.
2. often the value systematic characteristic position error compensates
A kind of storehouse by transfers for the designer. Like this in the components design stage, the designer only must input the characteristic the parameter, the system direct production characteristic example model: We must save the related characteristic class in the database the structure information, the database table collection are use in saving this part of related information. According to the characteristic type definition need, we defined the characteristic class code table, the characteristic class edition information have outstanding shown the characteristic type; Defined the characteristic class structure outstanding to reach the characteristic class the structure; And relates through the components characteristic disposition table and the components characteristic level information. The characteristic level data sheet collection is this components model database design core, has recorded characteristic example information and so on model design, craft. The characteristic structure table has recorded the characteristic geometry structure; The characteristic size table, the characteristic shape position table of limits, the characteristic surface roughness table has recorded the characteristic project semantics quotation; The size table, the shape position table of limits, the surface roughness table saved all components characteristic data message. In the characteristic level, using characteristic ID, geometry principal linkage and so on essential factor ID, size ID, common difference ID, roughness ID carries on the data retrieval. We apply this components information model database under the factory environment some module CAD in the AM integrative system, has realized CAD and the CAPP characteristic information sharing well. Main use ready-made CAD/the CAM software (Unigra phics 1I) carries on the product design and the NC programming in this system, and through carries on two times of developments gains components to this software the size information; At the same time uses the dialogue window which develops voluntarily, lets design the personnel to input other characteristic information alternately, realizes this software and the system sharing database connection. When assistance technological design, the technological design personnel through the procedure inquiry function, inquires the components information from the sharing database which needs, carries on the interactive technological design. Thus has facilitated the CAPP components information acquisition, enhanced the technological design efficiency. When carries on the NC programming using UG, may from the sharing database gain the craft and the manufacture information which needs, carries on various working procedures the knife axle design and the processing simulation establishes an absolute zero spot on the numerical control engine bed, the actual various coordinate axes syzygy completely position error, makes the curve in order to determined compensates the spot. Attempts l to show is an actual position error curve, (error) carries on this curve y-coordinate take the pulse equivalent as the unit the division, makes the horizontal line, each horizontal line and the curve point of intersection namely compensates the spot for the goal. Chart 1 the center 1 to 6 o'clock place position errors for, needs to do reduces the pulse to compensate; But needs to carry on 6 to 9 adds the pulse to compensate in the chart the shadow partially for to compensate the area. Compensates the range of points these to become the error
The calibration corrections stores the computer, when work table by zero displacement in position, installs sends out the absolute zero point localization signal in the absolute zero point micros witch, later computer as necessary will send out the goal to compensate to compensate the signal, will carry on the position error to the engine bed to compensate. The cosine generator assigns slide guage initiation signal a electricity and by step of transmission.
3. feedbacks compensates the open-loop control
Chart 2 has produced this kind of system schematic diagram. This system surveys two parts by the open-loop control and the induction synchromesh direct position to be composed. Here position examination does not serve as the position the feedback, but is compensates the feedback as the position error. Its cardinal principle is: Installs the instruction pulse by the engine bed numerical control which CNC sends out, on the one hand the supplies open system, the control step-by-steps the electrical machinery according to the instruction revolution, and the direct drive platen moves, constitutes the open-loop control; On the other hand this instruction pulse supplies the induction synchromesh the measurement system (namely digitally, cosine generator), as position demand signal a by. The work in the warning way induction synchromesh this time not only is the position sensor, also is the comparator, it by, The cosine generator assigns slide guage initiation signal a electricity and by step of transmission.
4. conclusions
Under the CIMS environment the technology which develops unceasingly based on characteristic components information modeling, how enhances the components order of complexity which the characteristic design can complete; How causes question and so on request which the characteristic design adoption trick recognition, the characteristic semantics transforms also to wait for the people to solve. This article introduced the characteristic technology in the components information modeling application, describes this components data model database realization with emphasis; Establishes the components information database system may satisfy the CIMS system well to the letter.
Reference:
[1].Zhang Huashu under. parallel environment based on characteristic components definition model [J]. mechanical science with technology, 1,999, 18 (1): 14l 144.
[2].forest morning star, Du full text, Xu Jianxin. characteristic and (',M)/CAPP/CAM integrative system [J]. the computer-aided design and makes, 1998, 28 (5): 5155.
[3].Zeng Hui E, Zhou Qingzhong. studied J based on the characteristic mechanical product modelling ]. the machinery to suppose Counts with the manufacture [ the regulation, 1,999, 28 (2): 12 ~ l4.
數(shù)控機(jī)床開環(huán)控制伺服系統(tǒng)
開環(huán)系統(tǒng)的優(yōu)點(diǎn)是系統(tǒng)簡單、成本低，但缺點(diǎn)是精度不高。反向間隙、絲杠螺距誤差、起停誤差等都會影響定位精度。下面幾種改進(jìn)措施可以使定位精度明顯改善。
1 反向間隙誤差補(bǔ)償
數(shù)控機(jī)床加工刀具與工件的相對運(yùn)動(dòng)是依靠驅(qū)動(dòng)裝置帶動(dòng)齒輪、絲杠轉(zhuǎn)動(dòng)，從而推動(dòng)工作臺面等移動(dòng)部件產(chǎn)生位移來實(shí)現(xiàn)的。作為傳統(tǒng)元件的齒輪、絲杠盡管制造精度很高，但總免不了存在間隙。由于這種間隙存在，當(dāng)運(yùn)動(dòng)的方向改變時(shí)，開始段時(shí)間必然會引起驅(qū)動(dòng)元件的空走，出現(xiàn)指令脈沖推不動(dòng)執(zhí)行元件的局面。這就影響了機(jī)床的加工精度，即指令脈沖與實(shí)際進(jìn)給步數(shù)不相符合，產(chǎn)生加工誤差 因此，開環(huán)數(shù)控系統(tǒng)一般都設(shè)置有反向間隙誤差補(bǔ)償功能，用以補(bǔ)足空走的步數(shù)反向間隙差補(bǔ)償就是首先實(shí)測反向進(jìn)給的誤差，把它折算成脈沖當(dāng)量數(shù)，作為間隙補(bǔ)償子程序的輸出量，當(dāng)計(jì)算機(jī)判斷出現(xiàn)的指令為反向運(yùn)動(dòng)時(shí)，隨即調(diào)用間隙補(bǔ)償子程序，通過輸出補(bǔ)償脈沖消除反向間隙后再進(jìn)行正常的插補(bǔ)運(yùn)行。
2 常值系統(tǒng)性定位誤差補(bǔ)償
類庫以供設(shè)計(jì)者調(diào)用。這樣在零件的設(shè)計(jì)階段，設(shè)計(jì)者只需輸入特征的參數(shù)，系統(tǒng)直接生成特征的實(shí)例模型：在數(shù)據(jù)庫中我們必須存儲相關(guān)的特征類的結(jié)構(gòu)信息，數(shù)據(jù)庫表集就是用于存儲這一部分的相關(guān)信息。根據(jù)特征類型定義的需要，我們定義了特征類編碼表、特征類版本信息表表示特征類型；定義了特征類構(gòu)造表表達(dá)特征類的結(jié)構(gòu)；并通過零件特征配置表與零件的特征層信息聯(lián)系起來。特征層數(shù)據(jù)表集是本零件模型數(shù)據(jù)庫設(shè)計(jì)的核心，記錄了特征實(shí)例模型的設(shè)計(jì)、工藝等信息。特征構(gòu)造表記錄了特征的幾何結(jié)構(gòu)；特征尺寸表、特征形位公差表、特征表面粗糙度表記錄了特征的工程語義引用；尺寸表、形位公差表、表面粗糙度表存儲了所有零件特征的數(shù)據(jù)信息。在特征層，利用特征ID、幾何要素ID、尺寸ID、公差I(lǐng)D、粗糙度ID等主鍵進(jìn)行數(shù)據(jù)檢索。我們將該零件信息模型的數(shù)據(jù)庫應(yīng)用于工廠環(huán)境下某型組件的CAD AM 集成系統(tǒng)中，較好地實(shí)現(xiàn)了CAD與CAPP的特征信息共享。在該系統(tǒng)中主要使用現(xiàn)成的CAD／CAM 軟件(Unigraphics 1I)進(jìn)行產(chǎn)品設(shè)計(jì)和NC編程，并通過對該軟件進(jìn)行二次開發(fā)獲取零件的尺寸信息；同時(shí)利用自行開發(fā)的對話窗體，讓設(shè)計(jì)人員交互輸入其它特征信息，實(shí)現(xiàn)該軟件與系統(tǒng)的共享數(shù)據(jù)庫的連接。在輔助工藝設(shè)計(jì)時(shí)，工藝設(shè)計(jì)人員通過程序的查詢功能，從共享數(shù)據(jù)庫中查詢所需的零件信息，進(jìn)行交互工藝設(shè)計(jì)。從而方便了CAPP的零件信息獲取，提高了工藝設(shè)計(jì)的效率。在利用UG進(jìn)行NC編程時(shí)，可以從共享數(shù)據(jù)庫中獲取所需的工藝及制造信息，進(jìn)行各工序的刀軌設(shè)計(jì)與加工仿真在數(shù)控機(jī)床上建立一個(gè)絕對零點(diǎn)，實(shí)測出各坐標(biāo)軸相對點(diǎn)的全部定位誤差，做出曲線以便確定補(bǔ)償點(diǎn)。圖l所示是一個(gè)實(shí)測的定位誤差曲線，把這個(gè)曲線的縱坐標(biāo)(誤差)以脈沖當(dāng)量為單位進(jìn)行分割，作出橫線，每個(gè)橫線與曲線的交點(diǎn)即為目標(biāo)補(bǔ)償點(diǎn)。圖1中的1到6點(diǎn)處的定位誤差為正，需要作減脈沖補(bǔ)償；而6至9處需要進(jìn)行加脈沖補(bǔ)償圖中陰影部分為補(bǔ)償區(qū)。把這些補(bǔ)償點(diǎn)列成誤差.修正表存入計(jì)算機(jī)，當(dāng)工作臺由零點(diǎn)位置移動(dòng)時(shí)，安裝在絕對原點(diǎn)處的微動(dòng)開關(guān)發(fā)出絕對原點(diǎn)定位信號，以后計(jì)算機(jī)將隨時(shí)發(fā)出目標(biāo)補(bǔ)償點(diǎn)的補(bǔ)償信號，對機(jī)床進(jìn)行定位誤差補(bǔ)償。
3 反饋補(bǔ)償開環(huán)控制
該系統(tǒng)由開環(huán)控制和感應(yīng)同步器直接位置測量兩個(gè)部分組成。這里的位置檢測不用作位置的反饋，而是作為位置誤差的補(bǔ)償反饋。其基本的原理是：由機(jī)床數(shù)控裝置CNC發(fā)出的指令脈沖，一方面供給開環(huán)系統(tǒng)，控制步進(jìn)電機(jī)按指令運(yùn)轉(zhuǎn)，并直接驅(qū)動(dòng)機(jī)床工作臺移動(dòng)，構(gòu)成開環(huán)控制；另一方面該指令脈沖又供給感應(yīng)同步器的測量系統(tǒng)(即數(shù)字式正、余弦發(fā)生器)，作為位置給定信號。工作在鑒幅方式的感應(yīng)同步器此時(shí)既是位置檢測器，又是比較器，它把由正、余弦發(fā)生器給定的滑尺激磁信號傳送給步進(jìn)電機(jī)。
4 結(jié) 論
CIMS環(huán)境下基于特征的零件信息建模還是一門不斷發(fā)展的技術(shù)，怎樣提高特征設(shè)計(jì)所能完成的零件復(fù)雜度；如何使特征設(shè)計(jì)適應(yīng)特征識別、特征語義轉(zhuǎn)換的要求等問題還有待人們?nèi)ソ鉀Q。本文介紹了特征技術(shù)在零件信息建模中的應(yīng)用，重點(diǎn)描述該零件數(shù)據(jù)模型的數(shù)據(jù)庫實(shí)現(xiàn)；所建立的零件信息數(shù)據(jù)庫系統(tǒng)可以較好地滿足CIMS系統(tǒng)對信。
參考文獻(xiàn)：
[1]. 張華書．并行環(huán)境下基于特征的零件定義模型 [J]．機(jī)械科學(xué)與技術(shù)，1999，18(1)：14l 144．
[2]. 林曉星，杜全文，許建新．特征與(M)／CAPP／CAM 集成系統(tǒng) [J]．計(jì)算機(jī)輔助設(shè)計(jì)與制造，1998，28(5)：51 55．
[3]. 曾慧娥，周慶忠．基于特征的機(jī)械產(chǎn)品造型研究 [J]．機(jī)械設(shè)計(jì)與制造 [程，1999，28(2)：1 2～l4．
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