【正文】 臂上升 = ； 搖 臂下降 LPP AN AN = LD T0 ON AN AN = ；液壓分配電磁閥 LD = ；主軸 箱 /立柱夾緊 指示 LDN = ；主軸箱 /立柱松開 指示 LDN AN 27 = ；中間轉(zhuǎn)換信號 LDN AN = ；中間轉(zhuǎn)換信號 LD A = ；中間轉(zhuǎn)換信號 梯形圖： 主軸運(yùn)行 代替 T0 瞬動觸點(diǎn) 失電延時(shí) 液壓泵正轉(zhuǎn) 液壓泵反轉(zhuǎn) 28 41PLC控制程序梯形圖 改造中必須注意的幾個(gè)問題 在設(shè)計(jì)過程中，會由于缺少經(jīng)驗(yàn)或者考慮不周等各種原因，造成設(shè)計(jì)出的系統(tǒng)不能滿足 控制的要求，或者沒有按照設(shè)計(jì)的要求來運(yùn)行等問題主要來自于兩個(gè)方面：一個(gè)是機(jī)械結(jié)構(gòu)方面的原因；另一個(gè)是軟件設(shè)計(jì)方面的時(shí)序問題。 （ 1）選擇 PLC機(jī)型時(shí)，要留有一定的裕量，為日后系統(tǒng)的修改及工藝的變更提供方便。 （ 1） 程序編寫完成后，首先要進(jìn)行模擬仿真。電路中 3 個(gè)時(shí)間繼電器的延時(shí)時(shí)間各不相同，分別為斷電延時(shí)閉合型、為斷電延時(shí)斷開型、通電延時(shí)閉合型。 （ 2） 梯形圖中，對液壓泵電機(jī)正反轉(zhuǎn)控制進(jìn)行了互鎖保護(hù)，同時(shí) 結(jié)合正反轉(zhuǎn)接觸器常閉觸點(diǎn)在輸出電路的互鎖，實(shí)現(xiàn)雙重保護(hù)，避免電源短路，有效保證安全。 安裝調(diào)試方面的問題 雖然 PLC的抗干擾能力較強(qiáng)，但是，為了保證控制過程的可靠性，仍然需要采取一定的抗干擾措施，主要有以下幾項(xiàng)措施?？刹扇∑帘巫儔浩骱碗娫礊V波等方式預(yù)防。 （ 3） PLC布線要盡量遠(yuǎn)離 高壓和高頻等設(shè)備。在手動程序中，尤其要注意每一個(gè)動作是獨(dú)立的。 30 小 結(jié) 這次畢業(yè)設(shè)計(jì)是對我在畢業(yè)之前的最后一次綜合性的考核 ,它全面考察了自己三年來各學(xué)科知識間的綜合應(yīng)用 ,是對自己的一次綜合能力的全方 面檢閱。通過這次設(shè)計(jì)使我對 PLC 知識有了更全面的了解。當(dāng)然，通過這次設(shè)計(jì)我也對 PLC 基本設(shè)計(jì) 有了更深的了解。 在此，我向指導(dǎo)老師和在設(shè)計(jì)期間給我諸多建議和幫助的同學(xué)們表示衷心的感謝！ 31 參考文獻(xiàn) 1.《工廠電器控制技術(shù)》 殷建國 北 京：經(jīng)濟(jì)管理出版社 2020 公司， SIMATIC S7200 可編程控制器系統(tǒng)手冊。s first mechanical development of one of the countries. In ancient China there are many aspects of mechanical invention, the driving force in the use of mechanical and structural design has its own characteristics. Many of the mechanical design and special applications such as vehicle guidance and the earth was moving in the instrument and incense burner, and so on, are unique. 5000 BC, the Chinese appear primitive tools of arable land Lei Si. This is the first in the history of China National Machinery and mechanical. Over time, ancient Chinese metalworking techniques to start germination, then gradually mature and skilled. Shang and Zhou dynasties, such as the simple bronze forceful, fine bronze of the Spring and Autumn Period sophisticated form of ancient Chinese bronzes unique style. Have been found in the earliest Chinese bronzes, such as Gansu Dongxiang Majiayao unearthed copper knives, had lapsed since 4800 About history. China has about 40 to 50 million years ago, has emerged processing crude scrapers, choppers and three sharp prismlike device, such as primitive tools. 4 to 5 million years ago, grinding technology, a number of stone tools have been relatively smooth, also a sharp edge, as well as singleblade, doubleedged, convex edge, concave edge and a round of subedge. China 28,000 years ago in the bow and arrow, this is the first of the mechanical aspects of an invention。 tools appear in about 6000 BC to before 5000, with the exception of Stone knives, there are stone hoe, shovel rock, stone sickle, sickle mussels, bone and bone sickle Si. Stone axes and knives have been used on the hard sand grinding from the hole. Xia Xia ago and has not appeared in the Quan spoke and wheel spokes are。 canoe and raft, and other water transport has long been emerging one after another. The late Neolithic Age, people have been able to Dan Fan Fan and mud casting of simple tools and weapons. Business Yin period, with the development of handicraft production and technical level, forming a brilliant bronze culture. Bronze metallurgy technology is highly developed, and bronze casting SECRETARY mother FANG Ding E, weighing 875 kg, bronze castings of the Spring and Autumn Period Cenghou Yi Pan statue has been very fine. WEI Han to the Spring and Autumn Period (770 BC265 AD) is the ancient Chinese machinery to start a period of rapid development. Spring and Autumn Period and pig iron metallurgy technology began to emerge。 Spring and Autumn since the midinvented lost wax casting and low melting point solder alloy casting technology 。 the midWestern Han Dynasty have been a gray cast iron smelting, and there have been 3 to 5 mm in wall thickness of the thinwalled cast iron pieces. Cast iron 33 heat treatment technology development. Spring and Autumn Period crossbows appear to control the fire Nuji has a more ingenious mechanical devices. To the Han Dynasty, Nuji processing accuracy and surface finish has reached a very high level. Han crossbow with a ten stone to stone, and so on eight standards, these specifications indicate that the formation of machine building standards in the Han Dynasty have been initially established. Nuji to conduct their left, the blacksmith, mill workers, and other names. The spread of the Warring States period, Kao Gong Ji is the earliest existing crafts monographs, which have wheels in mind the manufacturing process. The stretch of the bow, arrows and speed of flight, have made the stability of the indepth exploration. Han has been a large number of various types of ships and three or four layers of the cabin floor boat. Some ships have been equipped with a rudder stern and efficient tool to promote the anizations. When was the Western Han Dynasty incense burner in the delicate structure, no matter how the ball rolling incense burner, the center of the hemisphere of the furnace can keep the state level. The next is to drive traffic and machinery, in 1980 unearthed the tomb of the First Qin Emperor Tong Juma on behalf of the casting technology of that time, metal processing and assembly processes. After the Eastern Han Dynasty, there have been recorded drum cars and car guide. Hutchison, a car slowed drum gear system, through the subdrum sound of the bracelet reported to the mileage. Ma Jun of the three countries created guidelines addition to the car with gear drive, there are automatic onoff device, technically and recorded wins in a drum car financing. The invention of automatic onoff device on gear transmission system has been developed to a considerable