【正文】 變化反應(yīng)現(xiàn)場設(shè)備的運(yùn)行狀態(tài),如閥門的開與關(guān),電機(jī)的啟動(dòng)與停止,位置開關(guān)的狀態(tài)等。（3）順序控制 順序控制是PLC最基本、,就是按照工藝流程的順序,在控制信號(hào)的作用下,、速度快、可靠性高、成本低、便于維護(hù)等優(yōu)點(diǎn),所以在實(shí)現(xiàn)單機(jī)控制、多機(jī)群控制、限位開關(guān)及其它現(xiàn)場給來的指令信號(hào)和傳感器信號(hào),控制機(jī)械運(yùn)動(dòng)部件進(jìn)行相應(yīng)的操作,、管道上電磁伐的自動(dòng)開啟和關(guān)閉、。（2）控制速度繼電器控制邏輯是依靠觸點(diǎn)的機(jī)械動(dòng)作實(shí)現(xiàn)控制，工作頻率低，毫秒級(jí)，機(jī)械觸點(diǎn)有抖動(dòng)現(xiàn)象。（4）PLC(可編程控制器)與MC(微機(jī))控制的區(qū)別微型計(jì)算機(jī)是在以往計(jì)算機(jī)與大規(guī)模集成電路的基礎(chǔ)上發(fā)展起來的，其最大特點(diǎn)是運(yùn)算速度快，功能強(qiáng)，應(yīng)用范圍廣，在科學(xué)計(jì)算，科學(xué)管理和工業(yè)控制中都得到廣泛應(yīng)用。而MC就必須根據(jù)實(shí)際需要考慮抗干擾問題及硬件軟件的設(shè)計(jì)，以適應(yīng)設(shè)備控制的專門需要。在一個(gè)控制系統(tǒng)中，PLC將集中于功能于功能控制上，而MC將集中于信息處理上。熟悉可編程序控制器、功能表圖及有關(guān)的編程語言有利于縮短編程時(shí)間，因此，工程設(shè)計(jì)選型和估算時(shí)，應(yīng)詳細(xì)分析工藝過程的特點(diǎn)、控制要求，明確控制任務(wù)和范圍確定所需的操作和動(dòng)作，然后根據(jù)控制要求，估算輸入輸出點(diǎn)數(shù)、所需存儲(chǔ)器容量、確定PLC的功能、外部設(shè)備特性等，最后選擇有較高性能價(jià)格比的PLC和設(shè)計(jì)相應(yīng)的控制系統(tǒng)。 、機(jī)型的選擇PLC按結(jié)構(gòu)分為整體型和模塊型兩類，按應(yīng)用環(huán)境分為現(xiàn)場安裝和控制室安裝兩類；按CPU字長分為1位、4位、8位、16位、32位、64位等。該編程器FX2N系列是PLC FX家族中最先進(jìn)的系列。工人把套上瓶蓋的瓶子放上輸送帶，此時(shí)按啟動(dòng)按鈕，旋蓋機(jī)開始工作。茂名學(xué)院本科畢業(yè)設(shè)計(jì)：某潤滑油小包裝生產(chǎn)線旋蓋機(jī)機(jī)械及控制系統(tǒng)設(shè)計(jì)結(jié)束語畢業(yè)設(shè)計(jì)是我們畢業(yè)前夕最后也是最重要的一份作業(yè)，是對我們?nèi)昵髮W(xué)的一個(gè)總結(jié)，包含了我們?nèi)曛兴鶎W(xué)知識(shí)的積累，更是提升我們能力的一種方式。系統(tǒng)的分析與設(shè)計(jì)過程也是對學(xué)習(xí)的總結(jié)過程，更是進(jìn)一步學(xué)習(xí)與探索的過程。在設(shè)計(jì)中，體會(huì)到理論必須和實(shí)際相結(jié)合。蔡老師在后來的研究進(jìn)程中為我指點(diǎn)迷津，幫助我開拓研究思路，精心點(diǎn)撥、熱忱鼓勵(lì)。在此，我要向諸位老師深深地鞠上一躬。 input Processing performance than the general automatic machine, high precision machining factors, can be suitable for processing and small batch, high accuracy and frequent flow, shape and plex workpiece, and can obtain good economic results.Along with the development of numerical control technology, the machine adopts CNC system, increasing variety lathes, milling, boring, grinding, drilling, gear cutting machine tools and electric spark machine tools, etc. In addition, can automatically change in one of the many process card processing center, turning centers, etc.Development historyIn 1948, the United States pasonce pany accept entrust us air propeller blades, airplane outline model processing equipment. Due to the plex and varied shapes, template, high precision machining equipment to general, and put forward the idea of puter controlled machine tools. In 1949, the pany at the Massachusetts institute of technology (MIT) servo laboratory, CNC, and began to study in 1952 successfully trialproduced by large vertical copy the milling modification of three coordinates CNC milling machine, soon started production, in 1957 formally put into use. It is in the process of development of manufacturing technology, marks an important breakthrough in nc machining era. Nc machining is the foundation of modern manufacture technology, this invention for manufacturing industry, has epochmaking meaning and farreaching influence. The world39。s machine industry is through the readjustment of industrial structure, product structure, improve the ability of independent innovation, development, change from the international advanced manufacturing technology, cultivate enterprise high levels of independent development and innovation ability. With precise, efficient and flexible, plete, green demand for direction, to reform, reorganization and transformation, annexing international brand enterprises and products, to improve the domestic market share, expanding machine machine tool product development space.China39。s market value to 70%, including 61 per cent of homemade numerical control machine, industry to raise % 62% of fixed assets investment pleted a yearonyear growth of 36%. Media reports, 2009 China first became the first big machine producer. Not only such, China also in eight successive years is the first large consumer machine and the first importer.At the beginning, the global economy to rebound in China that signs, center for structural adjustment of the machine tool, investment enterprise showed signs of rapid growth in order. Expected 2010 year machine tool industry growth will reach about 10%, metalcutting lathes will achieve a doubledigit growth in high, Metalworking machine tools will import and export growth restorative.Second, China machine industry , one is cheap product performance overcapacityDue to our whole industry in western industrialized countries behind the level of enterprise39。s economic construction of highgrade for nc machine mainly rely on imports, China has a plete industrial chain, but the development of upscale numericalcontrol CNC system and functions required from outside the main parts. China export。s first machine production, but still is the world39。t respectively in where?A machine industry in China, the world39。 Since 1960, relatively simple and economic position control CNC drilling machine, and linear control CNC milling machine, the rapid development of CNC machine in mechanical manufacturing departments obtain promotion gradually. China started in 1958, developed successfully trialproduced a CNC valve of the numerical control system with CNC machine, 1965 started mass production of CNC system with transistor three coordinates nc milling machine.In 1965, third generation of integrated circuit, control devices, small size, power consumption, and reliability, the price drops further, promote the nc machine tools and the development of production. At the end of the 1960s, successively appeared by puter directly control tool machine direct numerical control system (hereinafter referred to as DNC), also called the group control system, Using small puter control puter numerical control system (hereinafter referred to as CNC control unit), which entered into the characteristics of small puters in the first generation.In 1974, successfully developed using microprocessor and semiconductor CunZhuQi microputer control devices (hereinafter referred to as newsun focus), this is the fifth CNC system. Fifth, pared with the third generation of numerical control equipment, function doubled in volume is reduced to the original 1/20, lower prices for 3/4 and reliability have greatly improved.In the early 1980s, with the puter software and hardware technology development, the manmachine dialogue to automatic programming of CNC. The numerical control equipment installed in miniaturization, can directly on the machine, The automation of CNC machine, automatic monitoring and