【正文】 35—38 區(qū))， 電磁鐵 YAl 一 YA4 有不同的通斷組 合，可得到工作臺(tái)各種不同的轉(zhuǎn)速。 時(shí)間繼電器 KT2 閉合后，經(jīng)過(guò)一定的時(shí)間，KT3 線圈通電閉合，使接觸 器 KMl、KMY 通電吸合，主拖動(dòng)電動(dòng)機(jī) M1 做短時(shí)啟動(dòng)運(yùn)行，促使變速齒 輪嚙合。按下橫梁上升按鈕 SBl5(68 區(qū))，中間繼電器 K12 線圈 通電吸合，繼而橫梁放松電磁鐵 YA6(33 區(qū))通電吸合，接通液壓系統(tǒng)油路， 橫梁夾緊機(jī)構(gòu)放松，然后行程開(kāi)關(guān) STSTSTSTl0(63 區(qū))復(fù)位閉合， 接觸器 KM9 線圈(64 區(qū))通電閉合，橫梁升降電動(dòng)機(jī) M3 正向啟動(dòng)運(yùn)轉(zhuǎn)，帶動(dòng) 橫梁上升。松開(kāi)按鈕 SBl4， 橫梁下降停止。松開(kāi)按鈕 SB8，右立刀架快速移動(dòng)電動(dòng)機(jī) M4 停轉(zhuǎn)。 2)右立刀架進(jìn)給控制。 (8)左、右立刀架快速移動(dòng)和工作進(jìn)給制動(dòng)控制。 左立刀架快速移動(dòng)和工作進(jìn)給制動(dòng)控制的工作過(guò)程相同。 如不 吸合，測(cè)量 2—15 是否有電壓。 看 Kl 是否吸合，如不吸合，可能是 K 的動(dòng)合觸點(diǎn)、SB4 觸點(diǎn)、SB3 及 STl 動(dòng)斷觸點(diǎn)接觸不良。 如對(duì)齒輪嚙合情況不甚了解， 可改用電壓法進(jìn)行檢查。 （1）工作臺(tái)變速故障 工作臺(tái)變速分四步進(jìn)行：第一步鎖桿抬起；第二步變速電磁鐵根據(jù) SAl 變速開(kāi)關(guān)接通情況，推動(dòng)齒輪動(dòng)作；第三步電動(dòng)機(jī)自動(dòng)伺服；第四步齒輪嚙 合后鎖桿復(fù)位。若不動(dòng) 作，可短接觸點(diǎn) SB7(8～32)、KM3 動(dòng)斷觸點(diǎn)(32～33)、KT4(33～34)和 K3 觸點(diǎn)(8～36)，這樣可以檢查出繼電器 K3 的故障。 經(jīng)檢查或看到鎖桿抬起，觀察變速電磁鐵是否在相應(yīng)位置動(dòng)作。如不動(dòng)作，可在按著 SBl4 的情況下， 短接 SBl4(72～86)。因橫梁下降接觸器 KMl0 的線圈電路中串聯(lián)的觸點(diǎn)較多、其中任一觸點(diǎn)接觸不良或不閉合，都會(huì)導(dǎo)致 KMl0 不吸合，用短接法檢查更為方便。特別強(qiáng)調(diào)，ST7～ STl0 是夾緊裝置控制的位置開(kāi)關(guān)，絕對(duì)不能用長(zhǎng)短接法短接標(biāo)號(hào) 73 至 77 來(lái) 檢查故障。 在這種情況下，可利用電氣控制柜和接線盒來(lái)檢查故障。 如不吸合， 可短接 SBll(3—203)、 KAl4(203—205)、KA8(202～12)，使可檢查出 KM7 不吸合的故障點(diǎn)。C5225 型立式車床的系統(tǒng)設(shè)計(jì)，C5225 型立 式車床機(jī)床適用于電機(jī)、水輪機(jī)、航空、軍工、礦山、冶金等機(jī)械行業(yè)，可 對(duì)回轉(zhuǎn)零件進(jìn)行內(nèi)、外圓柱面、端面、公英制螺紋、切槽、圓錐面的粗、精 加工。刀具 的快速移動(dòng)、 冷卻泵和液壓泵等常采用單獨(dú)的電動(dòng)機(jī)驅(qū)動(dòng)。在此，向蔣老師衷 心的表示感謝！同時(shí)，也要感謝其他老師和同學(xué)的熱心幫助！ 大學(xué)是我一生的重要階段，是學(xué)習(xí)專業(yè)知識(shí)及提高各方面能力為以謀 生發(fā)展的重要階段。在我們即將走向社會(huì)的時(shí)候，我們必須 對(duì)自己的職業(yè)生涯進(jìn)行規(guī)劃。愿借您的慧眼，開(kāi)拓我人生的旅程。 this information may be telephone conversation, instrument read or a pany’s accounts, but in each case the same main type of operation are involved: the processing, storage and transmission of information. in conventional electronic design these operations are bined at the function level。 the controller can be implemented as a generalpurpose microputer rather like a more robust version lf a hobby puter, or as a ‘packaged’ system, signed for replacing controllers based on older technologies such as electromagnetic relays. In the former case the system would probably be programmed in conventional programming languages such as the ones to9 be introduced later, while in the other case a specialpurpose language might be used, for example one which allowed the function of the controller to be described in terms of relay interconnections, In either case programs can be stored in RAM, which allows them to be altered to suit changes in application, but this makes the overall system vulnerable to loss lf power unless batteries are used to ensure continuity of supply. Alternatively programs can be stored in ROM, in which case they virtually bee part of the electronic ‘hardware’ and are often referred to as firmware. More sophisticated process controllers require miniputers for their 42 洛陽(yáng)理工學(xué)院畢業(yè)設(shè)計(jì)（論文） implementation, although the use lf large scale integrated circuits ‘the distinction controllers between mini of various and microputers, Products represent the exact the majority of and process kinds presentday on one’s microputer applications, figures depending interpretation of the word ‘product’. Virtually all engineering and scientific uses of microputers can be assigned to one or other of these categories. But in the system we most study Pressure and Pressure Transmitters. Pressure arises when a force is applied over an area. Provided the force is one Newton and uniformly over the area of one square meters, the pressure has been designated one Pascal. Pressure is a universal processing condition. It is also a condition of life on the planet: we live at the bottom of an atmospheric ocean that extends upward for many miles. This mass of air has weight, and this weight pressing downward causes atmospheric pressure. Water, a fundamental necessity of life, is supplied to most of us under pressure. In the typical process plant, pressure influences boiling point temperatures, condensing point temperatures, process efficiency, costs, and other important factors. The measurement and control of pressure or lack of itvacuumin the typical process plant is critical. The working instruments in the plant usually include simple pressure gauges, precision recorders and indicators, and pneumatic and electronic pressure transmitters. A pressure transmitter makes a pressure measurement and generates either a pneumatic or electrical signal output that is proportional to the pressure being sensed. In the process plant, it is impractical to locate the control instruments out in the place near the process. It is also true that most measurements are not easily transmitted from some remote location. Pressure measurement is an exception, but if a high pressure of some dangerous chemical is to be indicated or recorded several hundred feet from the point of measurement, a hazard may be from the pressure or from the chemical carried. To eliminate this problem, a signal transmission system was developed. 43 洛陽(yáng)理工學(xué)院畢業(yè)設(shè)計(jì)（論文） This system is usually either pneumatic or electrical. And control instruments in one location. This makes it practical for a minimum number of operators to run the plant efficiently. When a pneumatic transmission system is employed, the measurement signal is converted into pneumatic signal by the transmitter scaled from 0 to 100 percent of the measurement value. This transmitter is mounted close to the point of measurement in the process. The transmitter outputair pressure for a pneumatic transmitteris piped to the recording or control instrument. The standard output range for a pneumatic transmitter is 20 to 100kPa, which is almost universally used. When an electronic pressure transmitter is used, the pressure is converted to electrical signal that may be current or voltage. Its standard range is from 4 to 20mA DC for current signal or from 1 to 5V DC for voltage signal. Nowadays, another type of electrical signal, which is being mon, is the digital or discrete signal. The use of instruments and control systems based on puter or forcing increased use of this type of signal. Sometimes it is important for analysis to obtain the parameters that describe the sensor/transmitter behavior. The gain is fairly simple to obtain once the span is known. Consider an electronic pressure transmitter with a 20 mA ? 4mA 16 mA mA