【正文】 (terminal) limit switch, final terminal limit switch will activate to cut off power, forcing car to stop. It should function before car or counterweight touches buffer, and remains in service state while buffer is pressed. Unable to reset automatically, it can not reset until car is removed and bumping board is released. In figure 518 is shown the illustration of three types of limit switches.（三）工藝流程(鋼板）：數(shù)剪→普沖→折彎→與底板、連接板焊接組裝→噴涂→與終端開關(guān)組裝→裝箱 （鋼板）：數(shù)剪→數(shù)沖→折彎→與面板、連接板焊接組裝 （鋼板）： 普沖→折彎→與面板、底板焊接組裝 （鋼板）：普沖→折彎→電鍍→與終端開關(guān)組裝 ∕支架：數(shù)剪→普沖→折彎→噴涂→裝配緊固件（壓導(dǎo)板和六角螺栓螺母）→裝箱 ：鋸床鋸料→搖臂鉆孔→淬火打壓（兩端都要）→焊接→噴涂→裝箱（四）技術(shù)要求①電梯應(yīng)設(shè)極限開關(guān).②極限開關(guān)應(yīng)設(shè)置在盡可能接近端站時(shí)起作用而無誤動作危險(xiǎn)的位置上。強(qiáng)制驅(qū)動電梯的極限開關(guān)動作后，應(yīng)當(dāng)以強(qiáng)制的機(jī)械方法直接切斷驅(qū)動主機(jī)和制動器的供電回路 正常的端站停止開關(guān)（限位開關(guān)）和極限開關(guān)必須采用分別的動作裝置。該連接裝置一旦斷裂或松弛，一個(gè)電氣安全裝置應(yīng)使電梯驅(qū)動主機(jī)停止運(yùn)轉(zhuǎn) ①對強(qiáng)制驅(qū)動的電梯，應(yīng)用強(qiáng)制的機(jī)械方法直接切斷電動機(jī)和制動器的供電回路.②對曳引驅(qū)動的單速或雙速電梯，極限開關(guān)應(yīng)能切斷主電路或主接觸器線圈電路.③對于可變電壓或連續(xù)調(diào)速電梯（交流調(diào)壓調(diào)速電梯和變頻調(diào)速電梯），極限開關(guān)應(yīng)能迅速地，即在與系統(tǒng)相適應(yīng)的最短時(shí)間內(nèi)使電梯驅(qū)動主機(jī)停止運(yùn)轉(zhuǎn) 極限開關(guān)動作應(yīng)能防止電梯在兩個(gè)方向的運(yùn)行，且不經(jīng)過稱職人員的調(diào)整電梯不能自動恢復(fù)運(yùn)行。 ，不能使用普通的行程開關(guān)和磁開關(guān)、干簧管開關(guān)等傳感裝置。緩沖器是電梯最后一道安全裝置。圖59為緩沖器位置示意圖。同一臺電梯的轎廂和對重緩沖器其結(jié)構(gòu)規(guī)格是相同的。 while counterweight buffer is on counterweight board below counterweight frame. For an individual lift, buffer structure of car is the same as that of counterweight.（二）緩沖器的種類Buffer types緩沖器一般按結(jié)構(gòu)分為彈簧緩沖器(蓄能)和油壓緩沖器（耗能）兩種（圖510）。由于彈簧的反力作用使轎廂或?qū)χ氐玫骄彌_、減速。因此彈簧緩沖器的特點(diǎn)是緩沖后存在回彈現(xiàn)象，存在著緩沖不平穩(wěn)的缺點(diǎn)，所以彈簧緩沖器僅適用于低速電梯。當(dāng)電梯運(yùn)行到井道下部時(shí)，因斷繩或超載等各種原因，使電梯超越底層停站繼續(xù)下行，但下行的速度未達(dá)到限速器動作速度，在下極限開關(guān)不起作用的情況下，將撞擊設(shè)置在底坑的緩沖器。彈簧緩沖器一般用于額定速度在1m/s以下的電梯。When shocked by car or counterweight, spring buffer will deform to absorb energy from car or counterweight. After approaching the lower part of well, if lift runs by the bottom landing to continue due to rope rupture or overload, meanwhile, neither lift reaches the speed which will activate overspeed governor nor lower limit switch functions, collision will be preset on buffer in pit. When car runs by the top landing to continue and upper limit switch fails to function, counterweight will collide with counterweight buffer which absorbs energy of car or counterweight to alleviate the shock from car or counterweight. Spring buffer is used in lifts with speed of less than 1m/s. In figure 511 are shown two types of spring buffers.①聚氨酯緩沖器是利用聚氨酯材料頁數(shù)的微孔氣泡結(jié)構(gòu)來吸能緩沖，在受沖擊過程中相當(dāng)于一個(gè)帶有多氣囊阻尼的彈簧； ②重量輕、安裝簡單、無須維修、緩沖效果好，耐沖擊、抗壓性能好，在緩沖過程無噪音、無火花、防爆性好，安全可靠、平穩(wěn)。 buffer彈簧緩沖器的特性是制動力隨著壓縮行程的增大而增大，而油壓緩沖器在制停期間的作用力近似常數(shù)，從而使柱塞近似做勻減速運(yùn)動。在使用條件相同的情況下，油壓緩沖器所需的行程可以比彈簧緩沖器減少一半。柱塞下部有一空腔，柱塞四壁有一組泄油孔，油缸體平滑無孔。 圖513所示的油壓緩沖器，其泄油孔在缸體壁上。隨著活塞的下降，缸壁泄油孔數(shù)目逐漸減少，油流動的節(jié)流作用也隨之增大 ，由此產(chǎn)生足夠的油壓使轎廂的運(yùn)動減速，直到平滑地停止。這樣油經(jīng)溢流孔從油腔重新流回油缸，活塞自動恢復(fù)到原來位置。 cylinder is smooth without holes. When plunder is pressed, the upper cylinder es to cover the oil leakage holes on plunder, reducing number and total area of oil leakage holes.In figure 513 is shown oil buffer whose oil leakage holes are on cylinder walls. Plunder moves downwards, entering cylinder filled with hydraulic oil which is forced to enter exterior oil cavity through oil overflow holes of cylinder walls. With plunder moving downwards, oil leakage holes on cylinder walls decrease, throttling of oil flow increases, producing enough oil pressure to make car decelerate until it stops smoothly.After car is removed from the buffer, pressing spring makes plunder return to normal position. Consequently, oil flows to cylinder via overflow holes from cavity, and plunder automatically returns to its original position.圖514是最常用的一種錐形柱和環(huán)狀孔的油壓緩沖器。隨著柱塞的向下， 環(huán)狀孔的開度逐漸減小，導(dǎo)致制停力恒定。In figure 514 is a typical coneshaped oil buffer with circular holes. When plunder is pressed downwards into cylinder, oil will flow into interior cavity of empty plunder via circular holes, and oil flow is controlled by cone. With plunder moving downwards, circular diameter decreases gradually, resulting in constant brake force. To avoid producing variation of deceleration in the momentary activation and deactivation of buffer, different cone degree can be designed for upper, middle and lower cone, making the whole process of buffer action rather smooth.緩沖器的頭部由橡膠墊及封蓋組成，橡膠墊中間有一個(gè)帶有T形通氣孔的緊固螺栓，將橡膠墊與封蓋連接，便于向缸體內(nèi)注油，并使柱塞能自動復(fù)位。由上述可見，各種油壓緩沖器的構(gòu)造雖有所不同，但基本原理相同。當(dāng)轎廂或?qū)χ仉x開緩沖器時(shí)，柱塞在復(fù)位彈簧的作用下向上復(fù)位。Head of buffer is posed of rubber washer and gasket. In the middle of the rubber washer is there a fastening bolts with T hole which connects rubber washer and gasket, facilitating to inject oil in cylinder and making plunder automatically reset. During buffer process, bumping board presses rubber washer, sealed T hole can not function, therefore, highspeed gas flow can be avoided to eject oil fog outwards.From above mentioned, different as they are in structure, oil buffers work in same mechanism. When car or counterweight collides with buffer, plunder will move downwards, pressing oil in cylinder, making oil flow via throttling holes。 ②油壓緩沖器是一種耗能型緩沖器，它是利用液體流動的阻尼作用緩沖轎廂或?qū)χ氐臎_擊?！? ② 工作原理當(dāng)油壓緩沖器受到轎廂和對重的沖擊時(shí)，柱塞向下運(yùn)動，壓縮缸體內(nèi)的油，油通過環(huán)形節(jié)流孔噴向柱塞腔。由于油壓緩沖器是以消耗能量的方式實(shí)行緩沖的，因此它是一種耗能型緩沖器，而且無回彈作用。因而，油壓緩沖器具有緩沖平穩(wěn)的優(yōu)點(diǎn)，在使用條件相同的情況下，油壓緩沖器所需的行程可以比彈簧緩沖器減少一半。 ④緩沖器油的粘度與緩沖器能承受的工作載荷有直接關(guān)系，一般要求采用有較低的凝固點(diǎn)和較高粘度指標(biāo)的高速機(jī)械油。（三）緩沖器的基本結(jié)構(gòu)和工藝流程，底梁中間或?qū)ΨQ的兩端沖有緩沖器座的安裝孔。加高臺上下兩端分別沖有幾個(gè)與底梁和緩沖器座連接固定的孔。立柱根據(jù)加高臺所需高度可以用幾個(gè)角鋼拼合焊接而成，