光電開關(guān)檢測(cè)技術(shù)教學(xué)課件

光電開關(guān)檢測(cè)技術(shù)光電開關(guān)檢測(cè)技術(shù)光電開關(guān)檢測(cè)技術(shù)檢測(cè)技術(shù)光電開關(guān)檢測(cè)技術(shù)

光電開關(guān)光電開關(guān)漫反射式光電開關(guān)鏡反射式光電開關(guān)對(duì)射式光電開關(guān)槽式光電開關(guān)光纖式光電開關(guān)光電開關(guān)光電開關(guān)-工作原理

光電開關(guān)（光電傳感器）是利用被檢測(cè)物體對(duì)光束的遮光或反射，由同步回路選通而檢測(cè)物體的有無(wú)，所檢測(cè)的物體不限于金屬，對(duì)所有能反射光線的物體均可檢測(cè)。

光電開關(guān)-工作原理

PrincipleofPhotoelectricSensorPrincipleofPhotoelectricSensorEmittingmethodPulse-modulated

Mostofthephotoelectricsensorsemitabeamwhichispulse-modulated.Inthismethod,astrongopticalsignaloffixedwidthisemittedatafixedtimeinterval.Thishelpsthereceivertodistinguishthesignalfromextraneouslightandtoachievealongsensingrange.

PrincipleofPhotoelectricSensorPrincipleofPhotoelectricSensorUnmodulated

Thehigh-speedfibersensorFX2-A3RandthecolormarksensorLX-12Nseriesuseanunmodulatedbeam.Inthismethod,thebeamisemittedconstantlyatafixedintensity.Thisenableshigh-speedresponse,althoughthesensorsarealittlesusceptibletoextraneouslightascomparedtothesensorsusingamodulatedbeam.

PrincipleofPhotoelectricSensor光電開關(guān)-漫反射式光電開關(guān)漫反射光電開關(guān)是一種集發(fā)射器和接收器于一體的傳感器，當(dāng)有被檢測(cè)物體經(jīng)過時(shí)，將光電開關(guān)發(fā)射器發(fā)射的足夠量的光線反射到接收器，于是光電開關(guān)就產(chǎn)生了開關(guān)信號(hào)。當(dāng)被檢測(cè)物體的表面光亮或其反光率極高時(shí)，漫反射式的光電開關(guān)是首選的檢測(cè)模式。

光電開關(guān)-漫反射式光電開關(guān)漫反射式光電開關(guān)引起理想漫反射的光度分布

局部較強(qiáng)漫反射時(shí)的光度分布

Reflectivetype

光電開關(guān)-對(duì)射式光電開關(guān)

對(duì)射式光電開關(guān)的發(fā)射器和接收器是分離的，發(fā)射器發(fā)出的光線直接進(jìn)入接收器。當(dāng)被檢測(cè)物體經(jīng)過發(fā)射器和接收器之間且阻斷光線時(shí)，光電開關(guān)就產(chǎn)生了開關(guān)信號(hào)。當(dāng)檢測(cè)物體是不透明時(shí)，對(duì)射式光電開關(guān)是最可靠的檢測(cè)模式。Thru-beamtypeGeneraluse光電開關(guān)-槽式光電開關(guān)槽式光電開關(guān)通常是標(biāo)準(zhǔn)的U字型結(jié)構(gòu)，其發(fā)射器和接收器分別位于U型槽的兩邊，并形成一光軸，當(dāng)被檢測(cè)物體經(jīng)過U型槽且阻斷光軸時(shí)，光電開關(guān)就產(chǎn)生了檢測(cè)到的開關(guān)量信號(hào)。槽式光電開關(guān)比較安全可靠，適合檢測(cè)高速變化，分辨透明與半透明物體。U-shaped光電開關(guān)-鏡反射式光電開關(guān)

鏡反射式光電開關(guān)是集發(fā)射器與接收器于一體，光電開關(guān)發(fā)射器發(fā)出的光線經(jīng)過反射鏡，反射回接收器，當(dāng)被檢測(cè)物體經(jīng)過且完全阻斷光線時(shí)，光電開關(guān)就產(chǎn)生了檢測(cè)開關(guān)信號(hào)。RetroreflectivetypeGeneraluseWithpolarizingfiltersWithpolarizingfiltersWithpolarizingfiltersWithpolarizingfilters

Oppositetypesofpolarizingfiltersareplacedinfrontoftheemittingandreceivingelements.Ahorizontalpolarizingfilterplacedinfrontoftheemittingelementpassesonlyhorizontallypolarizedlightandaverticalpolarizingfilterplacedinfrontofthereceiverensuresthatonlyverticallypolarizedlightisreceived.Usingthisconfiguration,evenspecularobjectscanbereliablydetected.Withpolarizingfilters1NormalunpolarizedbeamemittedfromtheLEDoscillatesinarandommanner.Asitpassesthroughthehorizontalpolarizingfilter,theoscillationisalignedhorizontallyandthebeamishorizontallypolarized.2Whenthepolarizedbeamfallsonthereflector,itspolarizationisdestroyedandthereflectedbeamoscillatesinarandommanner.So,thereflectedbeamcanpassthroughtheverticalpolarizingfilterandreachthereceivingelement.

However,aspecularobjectdoesnotdestroythepolarization.Thereflectedbeamoscillateshorizontally,asbefore,andcannotpassthroughtheverticalpolarizingfilter.Withpolarizingfilters光電開關(guān)-光纖式光電開關(guān)光纖式光電開關(guān)采用塑料或玻璃光纖傳感器來(lái)引導(dǎo)光線，以實(shí)現(xiàn)被檢測(cè)物體不在相近區(qū)域的檢測(cè)。通常光纖傳感器分為對(duì)射式和漫反射式。優(yōu)點(diǎn)：體積小。PrincipleofopticalfiberPrincipleofopticalfiberWhenlightisincidentonthecore,itpropagatesinthecorebybeingtotallyreflectedattheboundarybetweenthecoreandthecladding.Aftertravelingthroughthefiber,lightspreadsatanangleofapprox.60°atthecableendandisdirectedonthesensingobject.

FibercablestructureFibercablestructureFibersensorsareclassifiedbroadlyintotwogroupsthrubeamtypeandreflectivetype.Thethru-beamtypehastwofibercables:theemittingcableandthereceivingcable.Thereflectivetypehasonefibercablethatcontains,both,theemittingpartandthereceivingpart.

光電開關(guān)的接線方式三線式光電開關(guān)的接線方式二線式光電開關(guān)的使用注意事項(xiàng)紅外線光電開關(guān)在環(huán)境照度高的情況下能穩(wěn)定工作，但原則上應(yīng)回避將傳感器光軸正對(duì)太陽(yáng)光等強(qiáng)光源。2.

當(dāng)使用感性負(fù)載（如燈、電動(dòng)機(jī)等）時(shí)，其瞬態(tài)沖擊電流較大，可能劣化或損壞交流二線的光電開關(guān)，在這種情況下，請(qǐng)經(jīng)過交流繼電器作為負(fù)載來(lái)轉(zhuǎn)換使用。3.紅外線光電開關(guān)的透鏡可用擦鏡紙擦拭，禁用稀釋溶劑等化學(xué)品，以免永久損壞塑料鏡。光電開關(guān)應(yīng)用舉例材料邊的控制倉(cāng)庫(kù)門警衛(wèi)高度辨別氣流量的監(jiān)測(cè)光電開關(guān)應(yīng)用舉例沖壓床安全監(jiān)視自動(dòng)注料物體倒置辨別料位控制光電開關(guān)應(yīng)用舉例進(jìn)出檢測(cè)不合格的檢出物體前后控制煙霧檢測(cè)光電開關(guān)應(yīng)用舉例圍墻警戒轉(zhuǎn)速檢測(cè)斷裂檢測(cè)直徑限制光電開關(guān)

應(yīng)用舉例定位剪切電動(dòng)扶