安全保護(hù)系統(tǒng).doc

第十章 安全保護(hù)系統(tǒng)Safety protection system規(guī)范性引用文件：1. GB 75882003 電梯制造與安裝安全規(guī)范（EN 811:1998，EQV）2. GB10060-2011電梯安裝驗(yàn)收規(guī)范3. GB8903-2005 電梯用鋼絲繩4. GB/T 100582009 電梯技術(shù)條件5. GB/T 100592009電梯試驗(yàn)方法6. GB/T 24474-2009電梯乘運(yùn)質(zhì)量測量7. TSG T7001-2009電梯監(jiān)督檢驗(yàn)和定期檢驗(yàn)規(guī)則-曳引與強(qiáng)制驅(qū)動電梯8. TSG T7001-2004電梯型式試驗(yàn)規(guī)程9. TSG T7004-2004無機(jī)房電梯型式試驗(yàn)細(xì)則10. TSG T7002-2005曳引和強(qiáng)制驅(qū)動式電梯型式試驗(yàn)細(xì)則11. GB/T 7024-2008電梯、自動扶梯、自動人行道術(shù)語12. GB50310-2002電梯工程施工質(zhì)量驗(yàn)收規(guī)范13. TSG T7011-2004電梯緩沖器型式試驗(yàn)細(xì)則14. TSG T7012-200電梯門鎖裝置型式試驗(yàn)細(xì)則15. TSG T7014-2004含電子元件的電梯安全電路型式試驗(yàn)細(xì)則16. TSG T7010-2005電梯安全鉗型式試驗(yàn)細(xì)則17. TSG T7009-2005電梯限速器型式試驗(yàn)細(xì)則18. TSG T7013-2005電梯轎廂上行超速保護(hù)裝置型式試驗(yàn)細(xì)則19. GB 24804-2009提高在用電梯安全性的規(guī)范20. 電梯安全要求 第1部分：電梯基本安全要求21. GB/T7025.1-2008電梯主參數(shù)及轎廂、井道、機(jī)房的型式與尺寸 第1部分：、類電梯0.1 總則電梯制造與安裝安全規(guī)范GB7588-20030.1.1 本標(biāo)準(zhǔn)從保護(hù)人員和貨物的觀點(diǎn)制定乘客電梯和載貨電梯的安全規(guī)范，防止發(fā)生與使用人員、電梯維護(hù)或緊急操作相關(guān)的事故的危險(xiǎn)。0.l.2 研究了電梯在下列方面的多種事故的可能性：0.1.2.1 可能因下列事故造成危險(xiǎn)：a)剪切；b)擠壓；c)墜落；d)撞擊；e)被困；f)火災(zāi)；g)電擊；h)由下列原因引起的材料失效：1)機(jī)械損傷；2)磨損；3)銹蝕。0.1.2.2 保護(hù)的人員：a)使用人員；b)維護(hù)和檢查人員；c)電梯井道、機(jī)房和滑輪間(如有)外面的人員。0.1.2.3 保護(hù)的物體：a)轎廂中的裝載物；b)電梯的零部件；c)安裝電梯的建筑。第一節(jié) 安全保護(hù)系統(tǒng)概述為了保證電梯運(yùn)行安全、可靠，電梯上設(shè)置了許多電氣、機(jī)械安全保護(hù)裝置。只要這些安全裝置能夠正常、有效地起到各自應(yīng)有的作用，就一定能保證電梯和乘客的絕對安全，做到萬無一失。To ensure lift to operate safely and reliably, electrical and mechanical safety devices are mounted on lift. Good function of these safety devices will guarantee the safety of lift and passengers.一、重要性電梯是頻繁載人的垂直運(yùn)輸工具，必須有足夠的安全性。電梯的安全，首先是對人員的保護(hù)，同時(shí)也要對電梯本身和所載物資以及安裝電梯的建筑物進(jìn)行保護(hù)。為了確保電梯運(yùn)行中的安全，在設(shè)計(jì)時(shí)設(shè)置了多種機(jī)械、電氣安全保護(hù)裝置。同時(shí)，電梯的維護(hù)和使用必須隨時(shí)注意，隨時(shí)檢查安全保護(hù)裝置的狀態(tài)是否正常有效，很多事故就是由于未能發(fā)現(xiàn)、檢查到電梯狀態(tài)不良和未能及時(shí)維護(hù)檢修，及不正確使用造成的。所以司機(jī)必須了解掌握電梯的工作原理，能及時(shí)發(fā)現(xiàn)隱患并正確合理地使用電梯。 二、基本結(jié)構(gòu)電梯安全保護(hù)系統(tǒng)中所配備的安全保護(hù)裝置一般由機(jī)械安全保護(hù)裝置和電氣安全保護(hù)裝置兩大部分組成。機(jī)械安全保護(hù)裝置主要有限速器、安全鉗、緩沖器、制動器、層門門鎖、轎門安全觸板、轎頂安全窗、轎頂防護(hù)欄桿、護(hù)腳板等。但有些機(jī)械安全保護(hù)裝置往往需要和電氣部分的功能配合和聯(lián)鎖才能實(shí)現(xiàn)其動作和功效的可靠性。例如層門的機(jī)械門鎖必須和電開關(guān)聯(lián)結(jié)在一起的聯(lián)鎖裝置。三、主要裝置 超越行程保護(hù)裝置:即端站保護(hù)裝置，由強(qiáng)迫減速、上下限位和終端極限開關(guān)三個(gè)終端開關(guān)及緩沖器組成。即：超越井道上、下極限工作位置時(shí)的保護(hù)裝置（上、下終端極限）；Protection device for upper and lower final limit in well, such as upper / lower final (terminal) limit； 超速保護(hù)裝置（限速器、安全鉗）：Overspeed protection device, such as overspeed governor, safety gear；。 門安全保護(hù)裝置：層門聯(lián)鎖Landing door interlock與轎門電氣聯(lián)鎖car door electrical interlock及門防夾人的裝置； 轎廂超載保護(hù)裝置 應(yīng)急救護(hù)裝置 即：停電或電氣系統(tǒng)故障時(shí)應(yīng)有轎廂慢速移動的救援措施（緊急救援設(shè)備）Rescue measures (emergency rescue device) should be provided for car to move slowly in case of power off or electrical failure. 各種裝置的狀態(tài)檢測保護(hù)裝置(如限速器斷繩開關(guān)、鋼帶斷帶開關(guān)) 確保功能完好下電梯工作以及電氣安全保護(hù)系統(tǒng)供電系統(tǒng)保護(hù)、電機(jī)過載、過流等裝置及報(bào)警裝置等。如: 供電系統(tǒng)斷、錯(cuò)相保護(hù)（只對交流電梯有效）Power cut-off, phase-reverse protection, only applicable to AC lift 底坑撞底緩沖器裝置（油壓緩沖器、彈簧緩沖器）Buffer in pit, such as oil buffer, spring buffer井道底坑有通道時(shí)，對重應(yīng)有防止超速或斷繩下落的裝置（對重側(cè)限速器、安全鉗）Counterweigh should be equipped with device which prevents overspeed or ruptured rope precipitation, such as overspeed governor and safety gear各類電氣安全保護(hù)裝置（電梯門口的光電開關(guān)等）；Various electrical safety protection devices (electro-optical switch located at entrance to landing door)；四電梯的安全鏈Lift safety chain將電梯的所有安全部件串在一起形成的安全回路俗稱為電梯的安全鏈。圖5-1為 蒂森TCM電梯的安全鏈，圖5-2為奧的斯SPEC60電梯的安全鏈。 Safety chain is referred to as safety circuit connected by all safety parts. In figure 5-1 is shown safety chain of Thyssen TCM lift; in figure 5-2 safety chain of Otis SPEC60.第二節(jié) 超越行程的保護(hù)裝置超越行程保護(hù)裝置即端站保護(hù)裝置，由強(qiáng)迫減（緩）速開關(guān)、上下限位開關(guān)和終端極限開關(guān)三個(gè)終端開關(guān)和緩沖器組成。緩沖器起到防止電梯蹲底的作用，是電梯的最后一道機(jī)械安全保護(hù)裝置。一、終端開關(guān)（組件）（一）基本結(jié)構(gòu)終端開關(guān)組件由終端開關(guān)盒、終端開關(guān)盒支架、壓導(dǎo)板、撞弓、撞弓支架、終端開關(guān)及其安裝板組成。 終端開關(guān)盒由面板、底板和連接板組裝而成，在井道的最上端和最下端各安裝一根，每根用至少兩個(gè)支架，安裝時(shí)每個(gè)支架的一端固定在導(dǎo)軌相應(yīng)位置上，另一端固定在終端開關(guān)盒相應(yīng)位置上。 每個(gè)終端開關(guān)盒上安裝3個(gè)終端開關(guān)，開關(guān)結(jié)構(gòu)完全一樣，只是由于電氣連接方式不一樣所以功能不同。按電梯運(yùn)行方向分別是快車限位開關(guān)（即強(qiáng)迫減速開關(guān)，上下各一）、慢車限位開關(guān)（即上下終端限位開關(guān)）和終端極限開關(guān)（上下各一），速度較高的電梯還會把減速開關(guān)分為一級減速開關(guān)和二級減速開關(guān)甚至更多。1. 強(qiáng)迫減速開關(guān)Forcingdecelerationswitch強(qiáng)迫減速開關(guān)安裝在電梯井道內(nèi)頂層和底層附近。當(dāng)電梯在正常減速點(diǎn)未減速時(shí)，安裝在轎廂上的上、下開關(guān)撞板將使強(qiáng)迫減速開關(guān)動作，強(qiáng)迫電梯減速。Forcingdecelerationswitchesaremountedneartopandbottominwell.Ifliftdoesnotdecelerateinnormaldecelerationpoint,upperandlowerswitchwillactivate,forcinglifttodecelerate.2. 限位開關(guān)Limitswitch限位開關(guān)安裝在強(qiáng)迫減速開關(guān)的后面，當(dāng)減速開關(guān)一旦失靈，電梯未能減速停車而越過上、下端站平層位置時(shí)，限位開關(guān)動作，迫使電梯停止運(yùn)行。限位開關(guān)動作后，如轎廂有層樓召喚，電梯仍能運(yùn)行。Limitswitchismountedbehindforcingdecelerationswitch.Ifthelatterfails,liftrunbeyondtoporbottomlevelingposition,itwillactivate,forcinglifttostop.3. 極限開關(guān)（終端極限開關(guān)）Finallimitswitch(terminallimitswitch)極限開關(guān)是電梯安全保護(hù)裝置中最后一道電氣安全保護(hù)裝置。極限開關(guān)有機(jī)械式和電氣式兩種。機(jī)械式常用于載貨電梯；電氣式常用于載客電梯中。Asthelastelectricalprotectiondevice,finallimitswitchisclassifiedintomechanicalandelectricaltypes;theformerisusedincargolift,whilethelatterinpassengerlift. 機(jī)械式極限開關(guān)Mechanicallimitswitch此種開關(guān)僅用于低速載貨電梯。它的電氣開關(guān)部分被裝在機(jī)房內(nèi)與電源總開關(guān)串聯(lián)連接，控制著電源的總供電電源。機(jī)械控制部分被安裝在電梯井道內(nèi)，當(dāng)轎廂運(yùn)行到井道上、或下端站極限工作位置時(shí)，由于上、下端站強(qiáng)迫減速開關(guān)、限位開關(guān)相繼失效而使電梯超過平層位置50200mm時(shí)，轎廂開關(guān)撞板就與井道內(nèi)極限開關(guān)機(jī)械部分的上或下碰輪碰撞，并通過撞板及極限鋼絲繩拉動安裝在機(jī)房的極限開關(guān)，切斷電梯總供電電源，從而使轎廂停止運(yùn)行。由于該開關(guān)是非自動復(fù)位開關(guān)，因此每次動作后，需由維修人員查明動作原因，排除故障后，到機(jī)房才能用手動使其復(fù)位。Mechanicalfinallimitswitchisonlyusedincargolift.Itselectricalswitchpartisinstalledinmachineroomandinseriesconnectionwithpowerswitchtocontrolmainpowersupply;mechanicalcontrolpartisinstalledinwell.Shouldforcingdecelerationswitchandlimitswitchfailconsecutively,makingliferunbeyondlevelingpositionby50200mm,bumpingbarwillbumpwithupperorlowercamofmechanicalpartforlimitswitchinwellandpullfinallimitswitchtoactivate,cuttingoffmainpowersupplyandstoppingcar.Thisswitchisnon-autoresetswitch,therefore,techniciansshoulddetectthereasonafteritsactioneverytime;itcannotberesetmanuallyinmachineroomuntilfailureiseliminated.電氣式極限開關(guān)Electricalfinallimitswitch這種開關(guān)一般采用電氣行程開關(guān)，安裝在井道上、下限位開關(guān)的后面極限位置。當(dāng)電梯運(yùn)行快到行程的極限時(shí)，在強(qiáng)迫減速開關(guān)和限位開關(guān)均未起作用的情況下，撞板使此極限開關(guān)動作，切斷電梯控制回路電源，迫使電梯抱閘停車。該開關(guān)動作后電梯不能再啟動，經(jīng)查明原因排除故障后在機(jī)房將此開關(guān)短接，慢車離開此位置之后才能使電梯恢復(fù)運(yùn)行。這種開關(guān)通常用于快速和高速電梯中。極限開關(guān)必須在轎廂或?qū)χ匚从|及緩沖器之前動作。Asanelectricaltravelswitch,thisswitchismountedbehindupperandlowerlimitswitch.Beforeliftapproachestravellimit,shouldforcingdecelerationswitchandlimitswitchfailconsecutively,bumpingbarwillmakefinallimitswitchactivate,cuttingoffcontrolcircuitandforcingcartostopbymeansofbrake.Oncethisswitchactivates,liftwillstop.Afterfailureiseliminated,thisswitchwillbeshortcircuitedinmachineroom;liftwillrestartseveralminuteslaterafterslowcarleavesthisposition.Thisswitchisusuallyusedinfast-speedandhigh-speedlifts.Itmustactivatebeforecarorcounterweighttouchesbuffer.極限開關(guān)安裝在井道上端站和下端站附近相應(yīng)位置上如圖5-15所示。它是當(dāng)電梯轎廂運(yùn)行超過端站時(shí)，用于切斷控制電源的安全裝置。極限開關(guān)由碰板、碰輪及相應(yīng)的開關(guān)箱組成。典型的極限開關(guān)如圖5-16所示。 Limit switch is mounted in corresponding positions near upper terminal and lower terminal landing, as shown in figure 5-15. As a safety device, it is used to cut off control power when car runs by terminal landing. It is composed of bumping board, bumping cam and relevant switch box, as shown in figure 5-16, a typical limit switch. 帶碰輪的開關(guān)箱安裝在井道內(nèi)上、下端站附近的導(dǎo)軌開關(guān)支架上，碰板安裝在轎廂架上。其動作原理為，當(dāng)運(yùn)動的轎廂在上、下端站未能正常換速停車而繼續(xù)上行或下行到設(shè)定位置時(shí)，轎架上的碰板將與井道中開關(guān)箱上的碰輪相接觸，帶動碰輪臂使開關(guān)箱內(nèi)的開關(guān)動作，切斷控制電源，使曳引機(jī)停轉(zhuǎn)，制動器抱閘，轎廂停止運(yùn)行。Switch tank with bumping cam is mounted on rail switch frame of upper and lower terminal landings in well, and bumping boards on car frame. The mechanism of limit switch is as follows: when moving car fails to decelerate at the specific point but continues moving upwards or downwards, reaching a preset position, bumping board of car frame will contact bumping cam on switch box in well, driving bumping cam arm to make the switch inside box activate, cutting off control power, stopping traction machine, making brake engage, stopping car. 圖5-17為極限開關(guān)動作示意圖。In figure 5-17 is shown the operation of final (terminal) limit switch. 撞弓上下兩端有沖孔，并用支架固定在轎廂立柱上。撞弓用角鋼做成，其兩端需加工成一定的弧形。 終端開關(guān)盒面板上要壓出幾個(gè)凹圓形面供安裝開關(guān)時(shí)使用，但不可以壓穿。 受反繩輪位置及鋼絲繩路徑影響，有機(jī)房與無機(jī)房終端開關(guān)盒支架及撞弓支架的結(jié)構(gòu)形式有所差異。（二）原理作用一般電梯井道中上、下各設(shè)三級保護(hù)：強(qiáng)迫減速開關(guān)、終端限位開關(guān)、終端極限開關(guān)。強(qiáng)迫減速開關(guān)是防止電梯失控造成沖頂或蹲底的第一道防線，當(dāng)轎廂運(yùn)行至上、下端 站正常換速位置而未換速時(shí)，強(qiáng)迫換速開關(guān)將迫使轎廂換速停車。終端限位開關(guān)是防止電梯失控造成沖頂或蹲底的第二道防線。它們的安裝位置在強(qiáng)迫減速開關(guān)之后。當(dāng)轎廂經(jīng)過強(qiáng)迫減速開關(guān)仍未被強(qiáng)迫減速，限位開關(guān)將發(fā)揮作用迫使轎廂停車。Conventionally, three protections are arranged in upper and lower well respectively. They are forcing deceleration switch, terminal limit switch and final (terminal )limit switch.As the first protection, forcing deceleration switch is used to prevent lift from “colliding with ceiling” or “sinking on bottom” when car is out of control. When car fails to decelerate at the specific point before upper or lower terminal landings, forcing speed-shift switch will force car to decelerate until stop.As the second protection, final (terminal) limit switch is used to prevent lift from “colliding with ceiling” or “sinking on bottom”, when car is out of control. Mounted behind forcing limit switch, final (terminal) limit switch will activate to force car to stop when car fails doing so after passing forcing limit switch.終端極限開關(guān)是防止電梯失控造成沖頂或蹲底的最后一道防線。極限開關(guān)的位置在限位開關(guān)之后，當(dāng)強(qiáng)迫換速開關(guān)和終端限位開關(guān)均未起作用的情況下，終端極限開關(guān)動作切斷控制電源，使電梯失電停車。極限開關(guān)應(yīng)在轎廂或?qū)χ亟佑|緩沖器之前起作用，并在緩沖器被壓縮期間保持其動作狀態(tài)。極限開關(guān)動作后，不能自動復(fù)位，只由當(dāng)人為將轎廂移走脫開碰板后方能復(fù)位。圖5-18是上述開關(guān)的位置示意圖。As the last protection line, final terminal limit switch is used to prevent lift from “colliding with ceiling” or “sinking on bottom”, when car is out of control. Mounted behind final (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 compressed. Unable to reset automatically, it can not reset until car is removed and bumping board is released. In figure 5-18 is shown the illustration of three types of limit switches.（三）工藝流程1.終端開關(guān)盒面板(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 2.終端開關(guān)盒底板（鋼板）：數(shù)剪數(shù)沖折彎與面板、連接板焊接組裝 3.終端開關(guān)盒連接板（鋼板）： 普沖折彎與面板、底板焊接組裝 4.終端開關(guān)安裝板（鋼板）：普沖折彎電鍍與終端開關(guān)組裝 5.終端開關(guān)盒撞弓支架：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 6.撞弓：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.設(shè)置電梯應(yīng)設(shè)極限開關(guān).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。井道上下兩端應(yīng)當(dāng)裝設(shè)極限開關(guān),極限開關(guān)應(yīng)在轎廂或?qū)χ?如有)接觸緩沖器之前起作用，并在緩沖器被壓縮期間保持其動作狀態(tài)。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 2.獨(dú)立設(shè)置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。3.動作的實(shí)現(xiàn)對于強(qiáng)制驅(qū)動的電梯，極限開關(guān)的動作應(yīng)由下述方式實(shí)現(xiàn)：a利用與電梯驅(qū)動主機(jī)的運(yùn)動相連接的一種裝置；或b利用處于井道頂部的轎廂和平衡重（如有）；或c如果沒有平衡重，利用處于井道頂部和底部的轎廂對于曳引驅(qū)動的電梯，極限開關(guān)的動作應(yīng)由下述方式實(shí)現(xiàn)：a直接利用處于井道的頂部和底部的轎廂；或b利用一個(gè)與轎廂連接的裝置，如：鋼絲繩、皮帶或鏈條。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) 4.作用方法對強(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.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.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)5.動作后電梯的狀態(tài) 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。 6.防越程保護(hù)開關(guān)都是由安裝在轎廂上的撞弓觸動的，撞弓必須保證有足夠的長度，在轎廂整個(gè)越程的范圍內(nèi)都能壓住開關(guān)，而且開關(guān)的控制電路要保證開關(guān)被壓住(斷開)時(shí)，電路始終不能接通。 7.限位開關(guān)和極限開關(guān)必須符合電氣安全觸點(diǎn)要求，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。二、緩沖器Buffer（一）功能作用緩沖器是由于某種原因，轎廂或?qū)χ爻綐O限位置發(fā)生蹲底時(shí)，用來吸收轎廂或?qū)χ貏幽艿闹仆Ｑb置。緩沖器是電梯最后一道安全裝置。緩沖器安裝在井道底坑的地面上，轎廂和對重的下方。圖5-9為緩沖器位置示意圖。對應(yīng)于轎架下梁緩沖板的緩沖器稱轎廂緩沖器；對應(yīng)于對重架下方緩沖板的緩沖器稱對重緩沖器。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。For some reasons, when car or counterweight runs by limit position, resulting in “sinking on bottom”, buffer is used as brake device to absorb car or counterweight dynamic energy. As the last safety device for lift, it is mounted on floor of pit in well, below car and counterweight, as shown in figure 5-9. Car buffer is on buffer board below car frame; 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5-10）。Buffer is classified into spring buffer and oil buffer according to structure, as shown in figure 5-10.1. 彈簧緩沖器Spring buffer彈簧緩沖器一般由緩沖橡皮、緩沖座、彈簧、彈簧座等組成，是一種蓄能型緩沖器，因彈簧緩沖器在受到?jīng)_擊后，它將轎廂或?qū)χ氐膭幽芎蛣菽苻D(zhuǎn)化為彈簧的彈性變形能(彈性勢能)。由于彈簧的反力作用使轎廂或?qū)χ氐玫骄彌_、減速。但當(dāng)彈簧壓縮到極限位置后，彈簧要釋放緩沖過程中的彈性變形能使轎廂反彈上升，撞擊速度越高，反彈速度越大，并反復(fù)進(jìn)行，直至彈力消失、能量耗盡，電梯才完全靜止。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。彈簧緩沖器受到轎廂或?qū)χ氐臎_擊時(shí)，依靠彈簧的變形來吸收轎廂或?qū)χ氐膭幽?。?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?；虍?dāng)轎廂超越最高停站繼續(xù)上行，上極限開關(guān)不起作用的情況下，對重將撞擊底坑中的對重緩沖器，緩沖器將吸收轎廂或?qū)χ氐膭幽?，減緩轎廂或?qū)χ貙Φ卓拥臎_擊。彈簧緩沖器一般用于額定速度在1m/s以下的電梯。圖5-11所示兩種彈簧緩沖器示意圖。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 5-11 are shown two types of spring buffers.2.聚氨酯緩沖器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； 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)。已成為電梯行業(yè)首選緩沖器。3.油壓緩沖器Oil 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。油壓緩沖器是利用液體流動的阻尼，緩解轎廂或?qū)χ氐臎_擊，具有良好的緩沖性能。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。油壓緩沖器根據(jù)泄油孔的布置，可以設(shè)計(jì)成多種形式：圖5-12 為柱塞上帶有泄油孔的油壓緩沖器。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。當(dāng)柱塞被壓下時(shí)，缸體上部漸漸蓋住柱塞上的泄油孔，減少了泄油孔的數(shù)目和總泄油孔面積。 圖5-13所示的油壓緩沖器，其泄油孔在缸體壁上?；钊乱七M(jìn)入充滿液壓油的油缸中，油被迫從油缸壁的溢流孔進(jìn)入外部的儲油腔中。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。當(dāng)提起轎廂使緩沖器卸載時(shí)，壓縮彈簧使活塞回到正常位置。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。Spring buffer is characteristic of brake which increases with compressing advancement, while the brake of oil buffer remains approximately at constant value during brake process, therefore, plunder can be considered to decelerate at a constant value. Having good buffer effect, oil buffer takes advantage of fluid damper to alleviate shock from car or counterweight.Under same condition, oil buffer travels only half distance of spring buffer.According to oil leakage arrangement, oil buffer can be designed in several structures:In figure 5-12 is shown oil buffer with oil leakage holes on plunder. There is a cavity below the plunder and a group of oil leakage holes on walls of plunder; cylinder is smooth without holes. When plunder is compressed, the upper cylinder comes to cover the oil leakage holes on plunder, reducing number and total area of oil leakage holes.In figure 5-13 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, compressing 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5-14是最常用的一種錐形柱和環(huán)狀孔的油壓緩沖器。當(dāng)柱塞向下壓進(jìn)油缸中，油通過環(huán)狀孔流進(jìn)空柱塞的內(nèi)腔，流量由其中的錐形柱控制。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。為了使緩沖器作用瞬間和終止瞬間不致產(chǎn)生減速度的突變，可將錐形柱上端、中部和下端設(shè)計(jì)成不同的錐度，使緩沖器動作的全過程都較平穩(wěn)。In figure 5-14 is a typical cone-shaped oil buffer with circular holes. When plunder is compressed 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。而在緩沖過程中，撞擊板壓住橡膠墊，T形通氣孔被封住不起作用，可避免緩沖時(shí)排出的高速汽流向外噴射油霧。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刈矒艟彌_器時(shí)，柱塞向下運(yùn)動，壓縮油缸里的油，使油通過節(jié)流孔外溢，在制停轎廂或?qū)χ剡^程中，其動能轉(zhuǎn)化為油的熱能，即消耗了電梯的動能，使電梯以一定的減速度逐漸停下來。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。油壓緩沖器用于額定速度在1m/s以上的電梯。Head of buffer is composed 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 compre