蝸輪箱體工藝及夾具設(shè)計(jì)(鉆孔和鏜孔）【兩幅夾具含CAD圖紙】
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寧波大紅鷹學(xué)院畢業(yè)設(shè)計(jì)（論文）任務(wù)書
所在學(xué)院
機(jī)電學(xué)院
專業(yè)
機(jī)械設(shè)計(jì)制造及其自動(dòng)化
班級(jí)
08機(jī)6(本)
學(xué)生姓名
沈玉萍
學(xué)號(hào)
08141010626
指導(dǎo)教師
龔方
題 目
基于UG CAD/CAM的箱體wl制造
一、 畢業(yè)設(shè)計(jì)（論文）工作內(nèi)容與基本要求：
箱體零件為大批量生產(chǎn)。在對(duì)箱體零件進(jìn)行零件圖分析和工藝分析的基礎(chǔ)上，制定零件加工工藝規(guī)程，設(shè)計(jì)1-2套工裝夾具，數(shù)控編程。
具體要求：
1．查閱文獻(xiàn)資料不少于12篇，其中外文資料不少于2篇。文獻(xiàn)翻譯不少于2000字，文獻(xiàn)綜述不少于3000字。
2．繪制箱體零件和毛坯圖。
3．制定零件加工工藝規(guī)程。
4．設(shè)計(jì)工序加工中所采用工裝夾具1-2套，繪制2D、3D-CAD裝配圖及部分主要零件圖。
5．?dāng)?shù)控加工需手工或自動(dòng)編制數(shù)控加工程序。
6．撰寫1萬字以上設(shè)計(jì)說明書一份，繪圖量為三張A0圖紙。
二、畢業(yè)論文進(jìn)度計(jì)劃
畢業(yè)設(shè)計(jì)（論文）時(shí)間： 2011 年 07 月 01 日至 2012 年 02 月 01 日
其中：1、2011年09月，開學(xué)前完成文獻(xiàn)資料查閱。翻譯外文論文，撰寫文獻(xiàn)綜述。
2、2011年09月20日，提交開題報(bào)告。
3、2011年11月01日，完成畢業(yè)設(shè)計(jì)（論文）第一稿。
4、2011年12月01日，完成畢業(yè)設(shè)計(jì)（論文）第二稿。
計(jì) 劃 答 辯 時(shí) 間： 2011 年 04 月 01 日
三、專業(yè)（教研室）審批意見：
審批人（簽字）：
機(jī)械與電氣工程學(xué)院
畢業(yè)設(shè)計(jì)（論文）外文翻譯
所在學(xué)院： 機(jī)電學(xué)院
班 級(jí)： 08機(jī)自6班
姓 名： 沈玉萍
學(xué) 號(hào)： 08141010626
指導(dǎo)教師： 龔方
合作導(dǎo)師：
2011年 12 月 9 日
原文：
DCS-Based Process Control Simulating System
Abstract: A distributed control system (DCS) based on two-layer networks for experimental teaching is presented in this paper. Three sets of equipments are used as process objects with their parameters such as pressure, temperature, level and flow rate being controlled variables. This system has multiform training functions. Students can not only set up basic experiments about the process control, but can also design complicated control system. The result of 4 years' use shows: it is an ideal engineering simulating system for students major in industrial automation.
Key Words: DCS, process control, simulating system, experimental teaching, network
1.INTRODUCTION
Control education is an integral part of the community's activities and one of its most important mechanisms for transition and impact. In 1998, the National Science Foundation (NSF) and the IEEE Control Systems Society (CSS) jointly sponsored a workshop in control engineering education which made a number of recommendations for improving control education . One of them is about experiments. Experiments continue to form an important part of a control education and projects should form an integral part of the curriculum for both undergraduate and graduate students . The idea of using distributed control system for process control emerged in the 1970s. Now it is widely used in manufacturing,chemicalindustry,papermaking, textile, food processing,power,etc.DCS integrating advanced computer, control, communications and CRT technologies has played an important role in raising technological level, reducing cost, and making production more flexible and integrated. So, it is very important to establish a DCS simulating system in university. We have set up the system in 2002. The system can bring more understanding of real-world problems to the students.
2.SYSTEM BUILDUP
Most modern industrial process control system adopts two-layer network topological structure. The lower one- field bus comes close to the process and the upper one-Ethernet mainly locates inside control room. Such structure disperses control and centralizes management and operation. Our system bases just this structure with the benefits of letting students familiar with current industrial network control. As shown in Figure 1, our system consists of 16 operator stations, one I/O station and 3 sets of process equipments.
2.1 The Distributed Computer System
From Figure 1 we can see that the distributed computer system is connected by two-layer networks. The monitoring network is implemented via 10M/100M pen Ethernet. The TCP/IP protocol is used. The buses connected by I/O stations and operator stations are information channels for plantwide supervision and control. According to the specifications of a process, the web server linked to Internet can also be set to achieve remote monitor. This network is arranged redundantly so the system proves reliable. The field network interconnected by I/O station and its I/O modules uses Profibus-DP and transmits a variety of information and parameters in real time.
The operator stations are general-purpose PCs. They act as engineering stations when used for off-line configuration, so 16 students can program at the same time. While for on-line use the students can monitor and control the process on these PCs. The I/O station is a domestic product developed by Beijing Hollysys Co., Ltd. Its design adopts standardization and modularization.The I/O station based on high-performance microprocessors and mature control algorithms can response as soon as possible to the internal and external events. It has 5 local modules i.e. two FM148 analog input cards, one FM151 analog output ard, one FM161 digital input card and one FM171 digital output card. Each card has particular microprocessor responsible for its control, test, calculation and diagnosis, thus, enhancing its selfcontrol level and dramatically improve its reliability and safety. The station or modules can be shifted without disturbance in case of trouble. Therefore, the system is able to control in real time and with high quality.
2.2Process Equipments
Process control is an important course of automatic major . After learning the theories in the classroom, the students have an eager for digesting and understanding. The control community has a strong history of impact on many important problems and industry involvement will be critical for the eventual success of the future directions. How to imitate industrial process is an important concern. We have built 3 sets of equipments representing pressure process, level process, temperature and flow rate process individually. The three sets of equipments can also be used for normal instrumentation control or direct digital control. All the connections are wired to the panel, so does the I/O station. The process equipments can be flexibly linked to different controller by plug contacts on the panels. There are different kinds of transducers installed on the process to provide a variety of signals such as tempera-ture, level, pressure and flow rate .These signals are analog inputs to DCS. The final operating elements include electric heater, switching components and control valves . DCS outputs analog or digital signals to the elements. The combination of the process equipments with the distributed computer system explores the frontiers of control, including increased use of computing, communications and networking, as well as exploration of control in application domains
3.SOFTWARE CONFIGURATION AND OPERATION
In the computer-control field, it has been customary to overcome some of the programming problems by providing table-driven software. A user of the DCS is provided with a configuration package that allows the user to generate a DCS system simply by configuring, so very little effort is needed to program. The package providing device, database, control scheme, graph and report forms configuration is run off-line on the engineering station. Configuration of the DCS is implemented from up to down by conforming to hardware structure. It is divided into the following 5 steps :
Devices registration to configure system hardware, including: the number of I/O stations or operator stations along with their network addresses and each I/O station's hardware such as data transmission card, I/O card;
Database configuration to define signal points and parameters set;
Control scheme configuration classified as conventional configuration which provides many control blocks like feedback, cascade, ratio and self-defined one that is programmed in real time control language similar to BASIC;
Graph configuration to make various pictures such as survey, standard display, adjust, control, trend, flow chart, alarm displayed on high-resolution color CRT and compound windows more abundant and menu-function more live; this configuration to configure diagrams for operator to monitor and control the process in real-time;
Report forms configuration to provide statistic report of the process. Before running the software, all the configurations must be compiled, linked and downloaded to the operators where several networked PC sharing the overall workload are able to monitor and control all aspects of process from a variety of live displays and friend interactions. Or the operator will run the system downloaded last time. The operator is extended with flat sealed film keyboard, touch screen, and global mouse to let operations easier. Through the man-machine interaction the process data can be collected, analyzed, recorded and controlled in real time; the system structure and configure loops can be modified on line; local breakdown can be fixed on line. Once the process is abnormal, the hardware will self diagnose and inform the operator stations that personnel around the field find the breakdown and that the indicator lamps on cards on I/O station shows the fault location. Such dual means of indication together with breakdown alarm and hot plug-in plug-out make it possible to fix breakdown on line and to run system safely and reliably.
4 .EXPERIMENTAL PROJECTS
Our DCS simulating system can train 16 students at the same time. The training functions are versatile from hardware and software configuration to complicated system design and debug. By I/O station 11 inputs from the 3 sets of equipments are measured and controlled, 7 control valves and 1 electric heater of the processes are manipulated in real time to implement temperature, pressure, level and flow rate control, breakdowns are detected and the system is maintained. Live measured values and status indications reveal the current situation. Process operators monitor and control the long-distance processes from their own consoles . The students operate the system as if they are in the real-world industrial automation. The flow chart of temperature and flow rate control sys-tem is shown in Figure 2. T1, T2 are measured temperature of the inner and outer water tank. FT1, FT2 are flow rate of the water into the inner and outer tank. WVL1 and WVL2 are two outputs from the I/O station to change the open range of the valves. ZK is a switch for turning on or off the electric heater. This system control is made up of 2 single variable closed-loops (T1-control and FTI Control),1cascade (T1-T2) and 1proportion(FT1-FT2) loop.All loops adopt normal PID which parameters can be dynamic adjusted from the operator station. The four control loops and main chart of the system can be easily shifted by pressing the buttons on the bottom of the graph as shown in Fig 2.
5 .CONCLUSION
The result of 4 years' use for both undergraduate and graduate shows: experimental training is especially efficient to help students understand the technique of industry process, the dynamic characters of the control system and to improve students' ability to operate and control the process. The convenient hardware connections make the DCS teaching system easily operated and the effortless software configuration renders different control algorithms implemented flexibly. Besides basic experiments about the process control, students have also designed complex control system to meet stricter product specifications.
譯文：
基于DCS過程控制仿真系統(tǒng)
摘要
本文提出的是一個(gè)建立在實(shí)驗(yàn)教學(xué)雙層網(wǎng)絡(luò)上的分布式控制系統(tǒng)（DCS）。其中配備三套設(shè)備，用于監(jiān)測(cè)實(shí)驗(yàn)過程對(duì)象中自身的流量、水平、溫度的次數(shù)變量。該系統(tǒng)具有多種形式的培訓(xùn)職能，學(xué)生不僅可以設(shè)立有關(guān)控制程序的基本實(shí)驗(yàn)，而且還可以設(shè)計(jì)復(fù)雜的控制系統(tǒng)。經(jīng)過4年的使用結(jié)果表明：DCS過程控制仿真系統(tǒng)是一個(gè)非常理想的工程模擬系統(tǒng)，我們可以利用它做工業(yè)自動(dòng)化的學(xué)習(xí)研究。
關(guān)鍵詞：DCS、過程控制，仿真系統(tǒng)，實(shí)驗(yàn)教學(xué)，網(wǎng)絡(luò)
1. 緒論
控制系統(tǒng)的教育機(jī)構(gòu)是社會(huì)體系中的組成部分，在有舉足輕重的位置，它是一個(gè)重要的轉(zhuǎn)變和影響機(jī)制。在1998年，美國(guó)國(guó)家科學(xué)基金會(huì)（NSF）和電氣和電子工程師控制系統(tǒng)協(xié)會(huì)（CSS）聯(lián)合舉辦教育控制工程教育研討會(huì)，本提出了如何改善控制系統(tǒng)的教育機(jī)構(gòu)的若干建議，其中就有關(guān)于實(shí)驗(yàn)的提議。研究人員表明DCS過程控制系統(tǒng)應(yīng)當(dāng)始終作為控制系統(tǒng)學(xué)習(xí)的重要組成部分，應(yīng)作為對(duì)本科生和研究生課程的組成部分。上世紀(jì)70年代，分布式控制系統(tǒng)就出現(xiàn)在過程控制應(yīng)用之中。到現(xiàn)在，它被廣泛用于制造，化工，造紙，紡織，食品加工，電力等各種領(lǐng)域。分布式控制系統(tǒng)結(jié)合了先進(jìn)的計(jì)算機(jī)，控制，通信和CRT技術(shù)，為生產(chǎn)技術(shù)水平不斷提高，減少成本起到重要的作用，使得生產(chǎn)更具有靈活性和綜合性。如此看來，我們?cè)诖髮W(xué)期間，建立一個(gè)DCS仿真系統(tǒng)是非常重要的。在2002年，我們成功建立了這個(gè)系統(tǒng)。該系統(tǒng)的建立，可以讓學(xué)生更多的了解實(shí)際遇到的問題。
2. 系統(tǒng)建立
大多數(shù)現(xiàn)代工業(yè)過程控制系統(tǒng)都是采用兩層網(wǎng)絡(luò)拓?fù)浣Y(jié)構(gòu)。系統(tǒng)采用一個(gè)較低的現(xiàn)場(chǎng)總線來關(guān)閉進(jìn)程，用一個(gè)以太網(wǎng)來控制整個(gè)系統(tǒng)操作，使用這種分散式結(jié)構(gòu)控制和集中管理和運(yùn)作。我們的系統(tǒng)就是基于這樣的機(jī)構(gòu)上，可以更有利于學(xué)生熟悉目前的工業(yè)控制。如圖1，我們的系統(tǒng)包括16個(gè)操作站，一個(gè)I / O站和3套加工設(shè)備
2.1分布式計(jì)算機(jī)系統(tǒng)
我們從圖1的分布式計(jì)算機(jī)系統(tǒng)可以看出，分布式計(jì)算機(jī)系統(tǒng)是由2層網(wǎng)絡(luò)連接組成。該監(jiān)測(cè)網(wǎng)絡(luò)是通過10M/100M以太網(wǎng)實(shí)施控制，并在TCP / IP協(xié)議下使用。系統(tǒng)由總線連接各個(gè)I/O站點(diǎn)，操作員站連接所有信息渠道，可以在整個(gè)系統(tǒng)范圍進(jìn)行監(jiān)督和控制。依據(jù)整個(gè)過程的結(jié)構(gòu)，在網(wǎng)絡(luò)服務(wù)器鏈接到互聯(lián)網(wǎng)的
條件下，也可以設(shè)置實(shí)現(xiàn)遠(yuǎn)程控制。該網(wǎng)絡(luò)采用冗余安排，以便使得系統(tǒng)絕對(duì)的可靠。外部網(wǎng)絡(luò)通過I/O總站連接到系統(tǒng)，并在I/O模塊中使用現(xiàn)場(chǎng)總線段落準(zhǔn)確的傳輸各種信息和參數(shù)
操作站作為工程總站，通過主機(jī)的控制，在不在現(xiàn)場(chǎng)的情況下，可以讓16名學(xué)生同時(shí)進(jìn)行工程訓(xùn)練，而且學(xué)生可以使用電腦程序通過網(wǎng)絡(luò)對(duì)這些操作進(jìn)程監(jiān)視和控制。該系統(tǒng)I/O控制站是基于北京和利時(shí)發(fā)展有限公司的產(chǎn)品，它的設(shè)計(jì)采用標(biāo)準(zhǔn)化和模塊化。該I / O站的基于高性能微處理器和成熟的控制算法，能盡快回應(yīng)系統(tǒng)內(nèi)部和外部的各種操作。它由5個(gè)本地模塊組成，即兩個(gè)FM148模擬輸入卡，一FM151模擬輸出卡，一卡FM161數(shù)字輸入和一個(gè)FM171數(shù)字輸出卡。每個(gè)卡都具有其特定的微處理器，負(fù)責(zé)不同的控制，測(cè)試，計(jì)算和診斷，由此來加強(qiáng)系統(tǒng)自身的控制水平，大大提高了它的可靠性和安全性。在糟糕的情況下，這樣的控制站可以一直啟動(dòng)無干擾模式。由此可見，這樣的系統(tǒng)可以保證高品質(zhì)的且非常準(zhǔn)確的控制
2.2工藝設(shè)備
過程控制是一個(gè)非常重要并且艱巨的工程。學(xué)生通過課堂理論學(xué)習(xí)之后，需要進(jìn)一步去消化和理解。而這個(gè)控制系統(tǒng)在過去很多年里影響到很多重要事件，
而在未來的發(fā)展方向主要與各個(gè)行業(yè)的合作，這將是最終取得成功的關(guān)鍵。如何去模仿工業(yè)過程是一個(gè)重要的問題。我們已建立3個(gè)獨(dú)立設(shè)備，分別用于代表壓力加工設(shè)備，工藝水平，溫度和流量水平。并且這3套的設(shè)備也可用于正常儀表控制或直接數(shù)字控制。所有設(shè)備都通過線路連接到控制面板，同時(shí)也連接到I/O站點(diǎn)，并且可以自由的與控制面板上的任何插頭連接。在過程控制系統(tǒng)中安裝有各種不同的傳感器，用于監(jiān)測(cè)如溫度，真實(shí)姿態(tài)，液位，壓力和流量，給控制站反饋多種信息。這些信息通過模擬輸入到DCS，然后通過電熱水器，開關(guān)元件，和控制閥等操作元件控制整個(gè)過程，形成一個(gè)反饋系統(tǒng)。然后集散控制系統(tǒng)輸出模擬或數(shù)字信號(hào)的元素。這套控制系統(tǒng)設(shè)備是與分布式計(jì)算機(jī)控制系統(tǒng)結(jié)合而進(jìn)行的前沿探索，包括增加使用的計(jì)算，通信和網(wǎng)絡(luò)，以及在應(yīng)用程序的控制等等。
3. 軟件配置和運(yùn)行
在計(jì)算機(jī)控制領(lǐng)域，已經(jīng)克服了驅(qū)動(dòng)軟件編程的一些問題。DCS系統(tǒng)為用戶提供一個(gè)配置包，允許生成一個(gè)簡(jiǎn)單的DCS系統(tǒng)配置，所以用戶可以很輕松的設(shè)計(jì)方案。這個(gè)提供有設(shè)備，數(shù)據(jù)庫(kù)，控制計(jì)劃，圖形和報(bào)表配置的系統(tǒng)包在工程站內(nèi)可以離線運(yùn)行，DCS的配置是順應(yīng)硬件結(jié)構(gòu)從上網(wǎng)下實(shí)現(xiàn)的。它分為一下5個(gè)步驟：
設(shè)備登記系統(tǒng)硬件配置，其中包括跟蹤其網(wǎng)絡(luò)的I / O站或操作站地址和每個(gè)I / O站的硬件，如數(shù)據(jù)傳輸卡，I / O卡
數(shù)據(jù)庫(kù)配置來定義信號(hào)點(diǎn)和參數(shù)設(shè)置
控制計(jì)劃配置列為常規(guī)配置，提供許多反饋控制塊，梯級(jí)，比率和自定義，這是類十余BASIC語(yǔ)言的實(shí)施控制程序。
用圖像來顯示各種諸如調(diào)查，標(biāo)準(zhǔn)顯示，調(diào)整，控制，趨勢(shì)，流程圖的數(shù)據(jù)，然后用高分辨率彩色顯像管和更豐富的復(fù)合窗口和菜單功能顯示操作現(xiàn)場(chǎng)，用此配置來配置運(yùn)行圖，一檢查和控制實(shí)時(shí)處理。
報(bào)告提供的統(tǒng)計(jì)表格配置的進(jìn)程。在運(yùn)行該軟件下，所有的配置都將被編譯，鏈接并下載到運(yùn)營(yíng)商，這個(gè)運(yùn)行商必須有幾個(gè)聯(lián)網(wǎng)的電腦用于共享整體工作情況，以便可以監(jiān)視和控制現(xiàn)場(chǎng)展示各種進(jìn)程的所有方面。或者經(jīng)營(yíng)者將運(yùn)行系統(tǒng)下載最后一次。經(jīng)營(yíng)者擴(kuò)展了平面密封薄膜鍵盤，觸摸屏和鼠標(biāo)，讓所有行動(dòng)更容易。通過人機(jī)互動(dòng)的過程中可以收集數(shù)據(jù)，分析，記錄和實(shí)時(shí)控制;該系統(tǒng)結(jié)構(gòu)和配置的循環(huán)可以被修改，在線，本地故障可在線修復(fù)。一旦這個(gè)過程是不正常的，硬件會(huì)自動(dòng)診斷并通知操作員站，現(xiàn)場(chǎng)工作人員圍繞故障進(jìn)行查找，并在卡片上我指示燈/ O站顯示故障位置。這種雙重手段的跡象說明具有連接故障報(bào)警和熱插件插件可以實(shí)現(xiàn)在線修正線路故障，使得系統(tǒng)運(yùn)行的更加安全可靠。
4. 實(shí)驗(yàn)項(xiàng)目
我們的DCS仿真培訓(xùn)系統(tǒng)可以讓16名學(xué)生同時(shí)操作。培訓(xùn)職能對(duì)硬件和軟件配置復(fù)雜的系統(tǒng)設(shè)計(jì)和調(diào)試都是通用的。I / O站的11個(gè)輸入點(diǎn)由3臺(tái)進(jìn)行測(cè)量和控制的設(shè)備，7個(gè)控制閥和一個(gè)電加熱器的進(jìn)程實(shí)現(xiàn)的。用于實(shí)時(shí)操作執(zhí)行溫度，壓力，液位，流量的控制和故障檢測(cè)和系統(tǒng)的維護(hù)。現(xiàn)場(chǎng)測(cè)量值和狀態(tài)的跡象表明目前系統(tǒng)的運(yùn)行狀況。自身的操作站可以處理系統(tǒng)運(yùn)行的過程監(jiān)控和控制，學(xué)生操作該系統(tǒng)，猶如他們是在現(xiàn)實(shí)工業(yè)自動(dòng)化操作中。溫度和流量控制系統(tǒng)，透射電鏡流程圖如圖2所示：T1和T2用來測(cè)量的內(nèi)，外水箱的溫度。FT1和FT2 用來顯示內(nèi)外水箱的水流流速。WVL1 and WVL2 是兩個(gè)從I/O站輸出的數(shù)值，控制閥門開啟程度。ZK是一個(gè)打開或關(guān)閉電加熱器的開關(guān)。該系統(tǒng)的控制是由2個(gè)單變量閉合回路（T1控制和FTI控制）、一個(gè)串聯(lián)(T1-T2)、一個(gè)比例循環(huán)(FT1-FT2)構(gòu)成。所有的回路采用從操作站動(dòng)態(tài)調(diào)整的常規(guī)PID。四個(gè)控制回路和系統(tǒng)的主要圖表可以很容易地轉(zhuǎn)向按本圖底部的按鈕，如圖2所示。
5.結(jié)論
在4年的本科和研究生的使用結(jié)果表明：實(shí)驗(yàn)培訓(xùn)可以非常有效的讓學(xué)生了解產(chǎn)業(yè)的工藝技術(shù)，而這個(gè)控制系統(tǒng)的動(dòng)態(tài)特性，更可以提高學(xué)生的操作和控過程的能力。便捷的連接，使DCS的硬件教學(xué)系統(tǒng)操作非常簡(jiǎn)便，同時(shí)簡(jiǎn)便的軟件配置使得實(shí)施不同的控制算法變的非常靈活。除了對(duì)于過程控制的基本實(shí)驗(yàn)，學(xué)生們還設(shè)計(jì)了復(fù)雜的控制系統(tǒng)，以滿足更嚴(yán)格的產(chǎn)品規(guī)格。
機(jī)械與電氣工程學(xué)院
畢業(yè)設(shè)計(jì)（論文）外文翻譯
所在學(xué)院： 機(jī)電學(xué)院
班 級(jí)： 08機(jī)自6班
姓 名： 沈玉萍
學(xué) 號(hào)： 08141010626
指導(dǎo)教師： 龔方
合作導(dǎo)師：
2011年 12 月 9 日
原文：
DESIGN AND USE OF AN EDDY CURRENT RETARDER
IN AN AUTOMOBILE
C. Y. LIU*, K. J. JIANG and Y. ZHANG
School of Automobile Engineering, Jiangsu Teachers University of Technology, Changzhou 213001, China
(Received 21 January 2010; Revised 13 December 2010)
ABSTRACT?In this study, the structure and working principles of an eddy current retarder acting as an auxiliary brake set is introduced in detail. Based on the principle of energy conservation, a mathematical model was developed to design a retarder whose nominal brake torque is 1, 900 N·m. According to the characteristics of the eddy current retarder, an exclusive test bed was developed and used for brake performance measurements. The main technical parameters, such as the brake characteristics, temperature characteristics and power consumption, were measured with the test bed. The test data show that the brake torque of the eddy current retarder obviously decreased in the continuous braking stage and that there is a certain amount of brake torque in the normal driving state because of the remnant magnetism of the rotor plate. The mathematical model could be used to design an eddy current retarder. The exclusive test bed could be used for optimization of an eddy current retarder as well as for R&D of a series of products.
KEY WORDS : Auxiliary brake, Eddy current retarder, Mathematical model, Design, Test
1. INTRODUCTION
Modern automobile design is focused on driving safety,comfort and environmental protection. With the increase in driving speeds and loads, the main brake system is no longer satisfactory for meeting the braking requirements of heavyduty vehicles and buses. Because of space constraints, it is hard to increase the braking efficiency of the main brake system through improved design. Traffic accidents usually occur when brake plates or brake drums become overheated after the main brake system has been working for a long time. This is especially true for long downhill routes.Technology laws have been put in place in many nations requiring that auxiliary braking devices must be installed for specific vehicles. Auxiliary braking devices include exhaust brakes, eddy current retarders, engine brakes and hydraulic retarders. The eddy current retarder is the most common type of auxiliary braking device.
Because it is a non-contact, continuous type of brake set,the eddy current retarder can improve comfort, especially in the automobiles used in the urban setting that need to brake frequently in the normal course of driving. This device is not used for stopping an automobile; it is only used as a complement to the main brake system. After an eddy current retarder is installed in an automobile, the frequency of main brake system use decreases, so the life of the brakes is extended. Because most of brake load is taken on by the eddy current retarder, the temperature rise in the brake disc or drum is reduced, and the braking efficiency of the main brake system is improved. Therefore, the safety of the automobile is also enhanced. Because the main brake system gets used rarely, the brake noise and dust can also be reduced, so this system benefits the environment. Currently, in heavy automobiles and large-scale passenger cars, the eddy current retarder has a standard configuration. However, the design technology of eddy current retarders needs to be perfected and developed further.
2. ANALYSIS MODEL
2.1. Structure and Working Principle An eddy current retarder is made up of eight cores, an air gap, coils and rotor plates, as shown in Figure 1. A coil is installed on the cylindrical surface of a core. The coil creates the windings. There is an even number of windings,and they are distributed equally around the circumference of the core. When the windings of the eddy current retarder are electrified, the kinetic or potential energy of the automobile can be transformed into thermal energy and dissipated into the atmosphere by a wind tunnel cast in the rotor plate, according to the electromagnetic principle.
3 TESTING AND ANALYSIS
3.1. Test-bed Structure and Operation The developed test bed was made up of a frequency conversion DC motor, a raising gearbox, an adjustable inertia flywheel group, a speed regulating device, and a series of sensors, such as a temperature sensor and a current sensor. The principle diagram of the test bed is shown in Figure 4. A DC motor was used for driving the raising gearbox. The eddy current retarder was connected with the transmission shaft. When an automobile is in a normal driving state, its kinetic energy is equivalent to the kinetic energy of the raising gearbox and the adjustable inertia flywheel group, so the developed test bed could model an automobile under different loads. Three temperature sensors were used for measuring the temperature rise of the two rotor plates and the windings. The torque and speed sensor was used for measuring the brake torque generated in the braking process and the rotational speed of the main shaft. The excitation voltage and excitation current was Figure 3. Design example of an eddy current retarder.Table 1. Calculated values of the brake characteristics for the eddy current retarder.
Characteristics Rotational speed (r/min) 200 400 600 800 1 000 1 200 Brake torque (N·m) 956 1468 1515 1529 1526 1506 Brake power (kW) 20.1 61.6 95.4 128.4 160.2 193.5 Figure 4. Principle diagram of the test bed。614 C. Y. LIU, K. J. JIANG and Y. ZHANG measured in order to study the excitation power and the power consumption characteristics of the eddy current retarder. Fans were used to simulate the wind speed in the process of running, and they also made it possible to simulate the actual thermal conditions of the eddy current retarder and could be used to cool the eddy current retarder rapidly. Test data were collected by the computercentralized control.
The test bed is shown in Figure 5. The test-bed operation process was as follows: First, the DC motor was started to drag the main shaft up to the intended rotational speed. The moment of inertia of the flywheel group was used to simulate the equivalent kinetic energy of running an automobile as an energy input of the eddy current retarder.Second, the windings were electrified in different shifts for field excitation,then the parameters, including the brake torque performance, the temperature performance and others, were measured.
3.2. Testing Capabilities and Test Items
The inertia of a 3~20 T full-load automobile could be simulated in the test bed. The rotational speed range of the main shaft was 0-3000 r/min. The following test items were performed on the test-bed. ① The brake torque rotational speed performance test: the brake torque generated by the eddy current retarder varied with the rotor speed. ② The brake torque–time characteristic, namely, the continuous brake performance test: the brake torque of the eddy current retarder varied with time at a constant rotational speed. ③ The temperature rise-time performance test: the temperature in the rotor plates and the stator changed with time as the eddy current retarder worked. ④ The brake torque-temperature performance test: the brake torque changed with temperature in the rotor plate. ⑤ The power consumption performance test: the working current and voltage in the windings varied with time as the eddy current retarder worked.
3.3.Analysis of the Test Results
The test ambient temperature was 20oC, and the air pressure was 0.1 MPa. The fourth brake shift of the retarder was used. From Figures 6 and 7, as the brake time
increased, the temperature in the rotor plate went up rapidly and then rose slowly. Joule heat generated by the eddy current in the rotor plate reached its steady state with the heat dissipating capacity of the blades. The maximum temperature on the latter rotor plate surface was approximately 505.6oC, and the temperature on the stator went up slowly compared with that on the rotor plate.When the wire was selected, a certain level of temperature tolerance must be considered.
4 CONCLUSION
A mathematical model of the eddy current retarder was developed. Based on this model, a brake torque retarder was designed. Many performance parameters were measured in an exclusive test bed. The major conclusions obtained are given below:
(1) The eddy current retarder that was designed met the requirements, which indicates that the mathematical model of brake torque developed in this study could be helpful for designing the product.
(2) Many performance parameters of the eddy current retarder could be measured in the test bed, and the test bed that was developed was based on design optimization of an eddy current retarder and R&D on a series of products.
(3) The brake torque dropped by approximately 40% after the temperature in the rotor plate reached its maximum value on the continuous stage. On the one hand, an excessive decline in the brake torque had a serious effect on the braking stability. On the other hand, the temperature rise in the rotor plate affected the life of the eddy current retarder. Meanwhile, it was adverse to safe driving. Certain actions must be taken to limit the temperature rise, such as implementing temperature
protection or time protection.
譯文：
在汽車中一個(gè)電渦流緩速器的設(shè)計(jì)與應(yīng)用
C. Y.劉*，K. J.江和Y張
中國(guó)常州江蘇技術(shù)師范學(xué)院，汽車工程學(xué)院
（2010年1月21日，2010年12月13日修訂）
摘要-在這項(xiàng)研究中,結(jié)構(gòu)和工作原理及一個(gè)電渦流緩速器制動(dòng)組表演作為一種輔助進(jìn)行了詳細(xì)的介紹。根據(jù)能量守恒原理,開發(fā)了一個(gè)數(shù)學(xué)模型,設(shè)計(jì)了一種緩速器制動(dòng)力矩的名義為1,900 N米。根據(jù)電渦流緩速器的特點(diǎn),研制了專用實(shí)驗(yàn)床并用于制動(dòng)性能的測(cè)量。主要技術(shù)參數(shù),如制動(dòng)特性、溫度特性和能量消耗,與試驗(yàn)測(cè)定了床上。試驗(yàn)數(shù)據(jù)表明,制動(dòng)器制動(dòng)力矩的明顯降低電渦流緩速器制動(dòng)階段連續(xù)且有一定的制動(dòng)力矩在正常的駕駛狀態(tài)因?yàn)闅埖拇呸D(zhuǎn)子盤。該數(shù)學(xué)模型可用于電渦流緩速器設(shè)計(jì)。獨(dú)家測(cè)試床可以用于電渦流緩速器的優(yōu)化，以及用于研發(fā)的系列產(chǎn)品。
關(guān)鍵詞:輔助剎車,電渦流緩速器的數(shù)學(xué)模型,設(shè)計(jì)、測(cè)試
1． 介紹
現(xiàn)代汽車的設(shè)計(jì)是集中在行車安全、舒適、環(huán)保。新增的駕駛速度和荷載作用下,不再是主要制動(dòng)系統(tǒng)的制動(dòng)要求滿足會(huì)議的heavyduty車輛和公共汽車。由于篇幅的限制,很難提高制動(dòng)效率的主要制動(dòng)系統(tǒng),通過完善的設(shè)計(jì)。交通事故通常發(fā)生在主剎車系統(tǒng)已經(jīng)很長(zhǎng)一段時(shí)間的工作時(shí)，剎車片或制動(dòng)鼓過熱。這尤其適用于長(zhǎng)坡的路線?？萍挤梢呀?jīng)到位, 需要特定的車輛必須安裝輔助制動(dòng)裝置的，許多國(guó)家尤其如此。輔助制動(dòng)裝置包括排氣制動(dòng)器，電渦流緩速器，發(fā)動(dòng)機(jī)制動(dòng)系統(tǒng)和液壓緩凝劑。電渦流緩速器輔助制動(dòng)裝置為最常見的類型。
因?yàn)樗且环N非接觸式，連續(xù)式制動(dòng)設(shè)置，電渦流緩速器可以提高舒適度，尤其是在城市環(huán)境中，需要在正常駕駛過程中經(jīng)常剎車的汽車。此設(shè)備是用于停車的汽車;只用它作為主剎車系統(tǒng)的補(bǔ)充。經(jīng)過電渦流緩速器是安裝在汽車的制動(dòng)系統(tǒng)使用跌幅的頻率，所以剎車的壽命延長(zhǎng)。由于大部分制動(dòng)負(fù)載是電渦流緩速，剎車盤或鼓的溫升降低，主剎車系統(tǒng)的制動(dòng)效率提高。因此，汽車的安全性也增強(qiáng)。由于主制動(dòng)系統(tǒng)很少被使用，剎車也可以減少噪音和灰塵，使這一制度有利于環(huán)境。目前，重型汽車和大型客車，電渦流緩速器的標(biāo)準(zhǔn)配置。然而，電渦流緩速器的設(shè)計(jì)技術(shù)需要進(jìn)一步完善和發(fā)展。
2． 分析模型
2.1。結(jié)構(gòu)及工作原理的電渦流緩速器是由八個(gè)內(nèi)核，氣隙，線圈和轉(zhuǎn)子板，如圖1所示。線圈安裝在圓柱表面的一個(gè)核心。線圈創(chuàng)建繞組。有一個(gè)繞組的偶數(shù)，和他們同樣圍繞核心的圓周分布。當(dāng)繞組的電渦流緩速器是電氣化，汽車的動(dòng)能或勢(shì)能可以轉(zhuǎn)化為熱能消散到大氣中，在轉(zhuǎn)子上的板蒙上了風(fēng)洞，根據(jù)電磁原理。
3．測(cè)試與分析
3.1試驗(yàn)臺(tái)的結(jié)構(gòu)和操作測(cè)試床是由一個(gè)直流電機(jī),變頻調(diào)速,可提高齒輪轉(zhuǎn)動(dòng)慣量飛輪組,調(diào)速裝置,以及一系列的傳感器,如溫度傳感器和一個(gè)電流傳感器。原理圖測(cè)試床被顯示在圖4。一個(gè)直流電機(jī)驅(qū)動(dòng)的用于提高變速箱。電渦流緩速器并與傳動(dòng)軸。當(dāng)一輛汽車是在一個(gè)正常的駕駛狀態(tài),其動(dòng)能等效為動(dòng)能增加變速箱和可調(diào)整的慣性飛輪集團(tuán),所以發(fā)達(dá)測(cè)試床可以在不同負(fù)荷模型汽車。三個(gè)溫度傳感器,用于測(cè)量的兩個(gè)轉(zhuǎn)子溫升板和繞組。的扭矩和速度傳感器用于測(cè)量制動(dòng)器制動(dòng)力矩和制動(dòng)過程中產(chǎn)生的主軸轉(zhuǎn)速。激勵(lì)電壓和勵(lì)磁電流圖3。設(shè)計(jì)一個(gè)電渦流緩速器的例子。表1。理論計(jì)算的制動(dòng)特性的電渦流緩速器。
特性轉(zhuǎn)速（轉(zhuǎn)/分）200 400 600800 1 0001200制動(dòng)力矩（牛頓?米）95614681515152915261506制動(dòng)功率（kW）20.161.695.4128.4160.2193.5圖4。 614 CY劉江，KJ和Y張?jiān)韴D的試驗(yàn)床。測(cè)量，以研究的勵(lì)磁功率和電渦流緩速器的功耗特性。球迷們用來模擬在運(yùn)行過程中的風(fēng)速，他們還提出了它可以模擬電渦流緩速器的實(shí)際熱條件，可用于電渦流緩速迅速冷卻。測(cè)試數(shù)據(jù)收集由計(jì)算機(jī)集中控制。
測(cè)試床如圖5所示。試驗(yàn)臺(tái)的操作過程如下：首先，開始拖動(dòng)直流電動(dòng)機(jī)主軸轉(zhuǎn)速達(dá)到了預(yù)期的。慣性飛輪組的時(shí)候，是用來模擬運(yùn)行作為汽車電渦流緩速器的能量輸入相當(dāng)于動(dòng)能。二，繞組在倒班工作現(xiàn)場(chǎng)勵(lì)磁,然后參數(shù),包括制動(dòng)器制動(dòng)力矩性能、溫度特性以及其他人都進(jìn)行了測(cè)量。
3.2 測(cè)試能力和測(cè)試項(xiàng)目
3?20噸的滿負(fù)荷的汽車的慣性可以在模擬試驗(yàn)臺(tái)。主軸轉(zhuǎn)速范圍0-3000轉(zhuǎn)/分。下面的測(cè)試項(xiàng)目進(jìn)行測(cè)試床。 ①制動(dòng)轉(zhuǎn)矩轉(zhuǎn)速性能測(cè)試:制動(dòng)器制動(dòng)力矩產(chǎn)生的電渦流緩速器轉(zhuǎn)子速度不同。②制動(dòng)轉(zhuǎn)矩時(shí)的特點(diǎn)，即連續(xù)制動(dòng)性能測(cè)試:制動(dòng)器制動(dòng)力矩的電渦流緩速器性能隨時(shí)間在恒定轉(zhuǎn)速上升。③溫度性能測(cè)試溫度在轉(zhuǎn)子和定子板隨時(shí)間不斷變化的電渦流緩速器的制動(dòng)轉(zhuǎn)矩溫度。④工作性能測(cè)試:制動(dòng)器制動(dòng)力矩隨溫度變化在轉(zhuǎn)子盤。⑤電耗性能測(cè)試:工作電流、電壓隨時(shí)間在繞組電渦流緩速器的工作。
3.3測(cè)試結(jié)果分析
測(cè)試環(huán)境溫度為20℃，空氣壓力為0.1 MPa。第四緩速制動(dòng)轉(zhuǎn)向使用。從圖6和7的制動(dòng)時(shí)間增加，在轉(zhuǎn)子盤的溫度上升迅速，然后緩慢上升。由渦流產(chǎn)生的焦耳熱轉(zhuǎn)子盤與刀片的散熱能力達(dá)到穩(wěn)定狀態(tài)。后者轉(zhuǎn)子鋼板表面的最高溫度約為505.6攝氏度，定子溫度上升緩慢相比，轉(zhuǎn)子盤電線被選中，一定程度的溫度公差必須考慮。
4結(jié)論
電渦流緩速器的一個(gè)數(shù)學(xué)模型的開發(fā)?；谶@個(gè)模型，設(shè)計(jì)一個(gè)制動(dòng)力矩緩速。許多性能參數(shù)測(cè)定在專用的試驗(yàn)床。所取得的主要結(jié)論如下：
（1）電渦流緩速器的設(shè)計(jì)符合要求，這表明，在這項(xiàng)研究中開發(fā)的制動(dòng)力矩的數(shù)學(xué)模型可能有助于設(shè)計(jì)的產(chǎn)品。
（2）許多性能參數(shù)可以衡量電渦流緩速器性能的測(cè)試,并對(duì)試驗(yàn)床床上進(jìn)行開發(fā)的基于優(yōu)化設(shè)計(jì)的電渦流緩速器和研發(fā)的一系列產(chǎn)品。
（3）制動(dòng)力矩在轉(zhuǎn)子板后溫度下降約40％，達(dá)到連續(xù)舞臺(tái)上的最大價(jià)值。一方面，在制動(dòng)力矩的過度下降嚴(yán)重影響了制動(dòng)穩(wěn)定性。另一方面，在轉(zhuǎn)子盤的溫度上升影響電渦流緩速器的使用壽命。同時(shí)，對(duì)安全駕駛不利。必須采取某些行動(dòng)限制溫度的上升,實(shí)現(xiàn)溫度等。
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