Kulukira kwa malo ndi njira yolumikizira mwachangu komanso yotsika mtengo. Ndi yoyenera kulumikiza zigawo zopyapyala ndi zolumikizira za m'chiuno zomwe sizifuna mpweya wokwanira. Pali mitundu yambiri ya kulukira kwa malo, monga kulukira kwa malo otsukira, kulukira kwa malo otsukira, kulukira kwa malo otsukira,kuwotcherera malo ophatikizika, ndi kuwotcherera malo a laser. Pakadali pano, kuwotcherera malo a resistance spot kumagwiritsidwa ntchito kwambiri popanga. Mwachitsanzo, makampani opanga magalimoto, amafunika malo odulira 3,000 mpaka 4,000 panthawi yosonkhanitsa zigawo za gulu la magalimoto, zomwe zimafuna maloboti 250 mpaka 300, pamodzi ndi makina othandizira owongolera ndi zida zina zothandizira. Komabe, kuwotcherera malo a resistance spot kuli ndi kusinthasintha kochepa. Ndi chitukuko chachuma chofulumira, kusintha kwa mawonekedwe ndi kapangidwe ka zigawo zamagalimoto kwakhala kochepa kwambiri. Kukweza zinthu zatsopano ndi mitundu kumafuna mtundu watsopano wa ukadaulo wowotcherera malo womwe ndi wothandiza komanso wosinthasintha. Chifukwa chake, ukadaulo wowotcherera malo a laser pang'onopang'ono wakhala chinthu chofunikira kwambiri ndipo akuyembekezeka kugwiritsidwa ntchito kwambiri popanga magalimoto. Mu gawo la ndege, kuwotcherera malo a laser kumayesedwanso ngati ukadaulo wina. Kwa nthawi yayitali, zolumikizira za zinthu zam'mlengalenga nthawi zambiri zakhala zikugwiritsa ntchito riveting, zomwe zimaphatikizapo njira zambiri zopangira ndi ntchito yambiri. Ndi kugwiritsa ntchito zinthu zatsopano monga aluminiyamu, titaniyamu, ndi zinthu zophatikizika, kugwiritsa ntchito ukadaulo watsopano wowotcherera kuti ulowe m'malo mwa njira zachikhalidwe zolumikizira kwakhala chizolowezi chachikulu. Izi sizimangowonjezera luso lopanga komanso zimachepetsa kulemera kwa kapangidwe kake ndikukwaniritsa zofunikira zatsopano pakupanga kapangidwe kake, zomwe ndizofunikira kwambiri pazinthu zam'mlengalenga. Kulondola kwambiri komanso kusinthasintha kwakukulu kwa laser spot welding kumapatsa ubwino waukulu pakupanga kothandiza, makamaka m'makampani opanga ndege, komwe kumatha kusintha njira zachikhalidwe monga resistance spot welding ndi riveting.
I. Tanthauzo ndi Makhalidwe a Laser Spot Welding
Tanthauzo
Kuwotcherera malo a laser kumatanthauza njira yosungunula ndi kulumikiza zida zogwirira ntchito pogwiritsa ntchito laser pulse imodzi (t > 1ms) kapena mndandanda wa ma laser pulses pamalo omwewo.
Kuwotcherera malo a laser kumafanana kwambiri ndi njira zina zowotcherera ma laser; kusiyana kokhako ndikuti palibe kusuntha pakati pa kuwala kwa laser ndi workpiece panthawi yowotcherera malo. Kuwotcherera malo a laser kumagawidwa m'mitundu iwiri: kuwotcherera kutentha ndi kuwotcherera ma keyhole. Mu kuwotcherera malo a thermal conduction, laser imatha kusungunula chitsulo popanda kuchitentha nthunzi. Njirayi ndi yoyenera kwambiri pa zitsulo zowotcherera zomwe zili ndi makulidwe osakwana 0.5mm, monga Nd:YAG laser spot welding ya zigawo zamagetsi. Mu kuwotcherera malo a keyhole laser, laser imatha kulowa mwachindunji mkati mwa zinthuzo kudzera mu keyhole, ndikuwonjezera kuchuluka kwa kugwiritsa ntchito mphamvu ya laser ndikufikira kuzama kwakukulu kolowera. Kuwotcherera malo achikhalidwe kumadzisungunula kuti apange ma weld spots pogwiritsa ntchito kutentha kolimba komwe kumapangidwa ndi magetsi, pomwe gwero la kutentha la kuwotcherera malo a laser limachokera ku kuwala kwa laser, zomwe zimapangitsa kuti pakhale mawonekedwe osiyana kwambiri a weld spot.
Magawo osinthika a laser spot welding nthawi zambiri amaphatikizapo mphamvu ya laser, nthawi yolumikizira malo, ndi kuchuluka kwa defocus. Pa spot welding pogwiritsa ntchito pulse mode, magawo amaphatikizaponso pulse waveform, frequency, ndi duty cycle. Pakati pa izi, mphamvu ya laser imakhudza kwambiri kuzama kwa malo olumikizira, pomwe nthawi yolumikizira malo imakhudza kwambiri kukula kwa mbali ya malo olumikizira. Nthawi zambiri, nthawi yayitali ya laser, kukula kwa pamwamba ndi pansi pa malo olumikizira malo kumakulanso komanso kukula kwa malo olumikizira. Kusintha kwa kuchuluka kwa defocus kumakhudza kwambiri kukula kwa malo ndi kuchuluka kwa mphamvu zomwe zimagwira ntchito pamwamba pa workpiece, motero zimakhudza kwambiri mawonekedwe onse a malo olumikizira.
Makhalidwe
- Pogwiritsa ntchito laser ngati gwero la kutentha, kuwotcherera malo kumapereka liwiro lapamwamba, kulondola kwambiri, kutentha kochepa, komanso kusintha pang'ono kwa ntchito.
- Mlingo wa ufulu m'malo olumikizira malo umakwera kwambiri, zomwe zimathandiza kuti malo onse azilumikizana mosavuta komanso kuti zinthu ziyende bwino.kuwotcherera malo mbali imodzi, motero kumawonjezera kwambiri ufulu wopanga zinthu.
- Kuwotcherera malo a laser kuli ndi zofunikira zochepa pa kukula kwa malo olumikizirana. Pali zoletsa zochepa pazigawo monga kuchuluka kwa malo olumikizirana ndi mtunda pakati pa malo olumikizirana, ndipo palibe chifukwa choganizira momwe shunting yamagetsi imakhudzira.
- Pakulumikiza mbale zosafanana, zinthu zosiyana, ndi zipangizo zapadera (zopangira aluminiyamu, mapepala opangidwa ndi galvanized), kulumikiza malo opangidwa ndi laser kumagwira ntchito bwino kuposa njira zachikhalidwe zolumikizira malo.
- Sichifuna zida zambiri zothandizira, chimatha kusintha mwachangu malinga ndi kusintha kwa zinthu, ndikukwaniritsa zosowa zamsika.
II. Kusanthula Kwabwino kwa Zolakwika za Laser Spot Welding
Ming'alu, ma pores, ndi kutsika kwa makoma ndi zolakwika zomwe zimafala kwambiri pakuwotcherera malo a laser, zomwe zimasanthulidwa chimodzi ndi chimodzi pansipa.
1. Ming'alu
Ming'alu imagawidwa m'magawo a ming'alu pamwamba ndi ming'alu yayitali. Kuchuluka kwa kutentha ndi kuzizira panthawi yogwiritsa ntchito laser spot welding kumathamanga kwambiri, zomwe zimapangitsa kuti kutentha kukhale kwakukulu pakati pa malo otentha ndi chitsulo chozungulira, zomwe zimapangitsa kuti ming'alu ipangike mosavuta. Kupezeka kwa ming'alu kumagwirizana kwambiri ndi zinthuzo; mwachitsanzo, zitsulo zotayidwa ndi aluminiyamu zimakhala ndi chizolowezi chachikulu chophwanya ming'alu panthawi yogwiritsa ntchito laser spot welding kuposa chitsulo chosapanga dzimbiri. Njira yothandiza yochepetsera kupangika kwa ming'alu ndikuwongolera mawonekedwe a pulse waveform kuti azitha kuziziritsa nthawi yogwiritsira ntchito chitsulo ndikuchepetsa kupsinjika kwamkati.
2. Mabowo
Zofooka za mabowo (mabowo) mu ma laser spot welds zitha kugawidwa m'mabowo ang'onoang'ono ndi ma pores akuluakulu. Mabowo ang'onoang'ono amayamba chifukwa cha kuchepa kwa kusungunuka kwa haidrojeni mu chitsulo chamadzimadzi panthawi yolimba kwa chitsulo, komanso kutuluka kwa chitsulo mwachangu mu keybool ndi kusokonezeka kwa dziwe losungunuka. Mabowo akuluakulu amayamba chifukwa cha kuzizira mwachangu kwambiri panthawi yolumikiza ma laser spot, zomwe zimapangitsa kuti chitsulo chozungulira keybool chisadzazenso. Kawirikawiri, mabowo ang'onoang'ono amatha kupangidwa mu long-pulse spot weld, pomwe mabowo akuluakulu amatha kuchitika mu short-pulse spot weld.
Pali malo awiri omwe ma pores amapezeka kwambiri mu laser spot welding: limodzi lili pafupi ndi fusion zone pakati pa weld spot, ndipo lina lili pa muzu wa weld. Zithunzi zosungunuka zomwe zajambulidwa ndi X-ray zikusonyeza kuti ma pores pafupi ndi fusion zone amayamba chifukwa cha kutsekeka kwa khosi pamene keybool itseka; pa ma pores omwe ali pa muzu wa weld, amapangidwa makamaka ndi kugwa kwa keybool chifukwa cha kutha msanga kwa laser pambuyo pa keybool.
3. Kutsika
Kutsika kwa madzi ndi chinthu chodziwikiratu mu laser spot welding. Kutsika kwa madzi pakati pa malo osungunula madzi ndi kusonkhana kwa zitsulo mozungulira kumachitika chifukwa cha mphamvu yobwerera m'mbuyo yomwe imapangidwa ndi nthunzi yachitsulo yomwe imakankhira chitsulo chamadzimadzi kupita pamwamba pa malo osungunula madzi. Panthawi yozizira, chitsulo chomwe chimasonkhanitsidwa pamwamba chimauma mwachangu ndipo sichingadzazidwenso mokwanira. Kuphatikiza apo, kutayika kwa zinthu komwe kumachitika chifukwa cha kusungunuka kwa madzi mwachangu ndi kufalikira kwa madzi ndi chinthu china chomwe chimapangitsa kuti pakati pawo pakhale kutsika kwa madzi. Nthawi ya pulse imakhudza kwambiri kutsika kwa madzi pamwamba pa malo osungunula madzi komanso mapangidwe a ma pores. Madontho okhutiritsa a weld amapezeka mwa kukonza mawonekedwe a pulse waveform ndi nthawi.
4. Zotsatira za Kuchuluka kwa Defocus pa Malo Omwe Amasefedwa
Kusintha kwa kuchuluka kwa defocus kumasintha mwachindunji kukula kwa malo ndi kuchuluka kwa mphamvu. Pamene kuchuluka kwa defocus kukuwonjezeka mbali zonse ziwiri zoyipa ndi zabwino, zikutanthauza kuti kukula kwa malo kumawonjezeka ndipo kuchuluka kwa mphamvu kumachepa. Pakuwotcherera malo a laser, pali ubale wofanana pakati pa kukula kwa malo ndi kukula kwa bowo loyambira lomwe limapangidwa ndi chochitika cha laser pa chidutswa choyesera, pomwe kuchuluka kwa mphamvu kumatsimikiza kuchuluka kwa kukula kwa dziwe losungunuka. Pamene mtengo wokwanira wa kuchuluka kwa defocus uli wochepa, kukula kwa malo a laser ndi kochepa, kuchuluka kwa mphamvu ya laser kumakhala kwakukulu, ndipo kuchuluka kwa kukula kwa dziwe losungunuka ndi lothamanga, koma kukula kwa bowo loyambira ndi kochepa. M'malo mwake, pamene kuchuluka kwa defocus kuli kwakukulu, kukula kwa bowo loyambira ndi kwakukulu, koma kuchuluka kwa kukula kwa dziwe losungunuka kumachepa, ndipo kukula kwa malo osungunuka sikungakhale kwakukulu. Chifukwa chake, panthawi yosintha kuchuluka kwa defocus, zotsatira zonse za kukula kwa malo ndi kuchuluka kwa mphamvu pamwamba pa malo osungunuka zimatsimikiza kukula kwa malo osungunuka.
III. Kugwiritsa Ntchito Ukadaulo Wowotcherera wa Laser Spot
Kuwotcherera malo a laser kumakhala ndi liwiro lalikulu, kuzama kwakukulu, kusintha kochepa, ndipo kumatha kuchitika kutentha kwa chipinda kapena pansi pazikhalidwe zapadera pogwiritsa ntchito zida zosavuta zowotcherera. Kuphatikiza apo, kuonekera kwa ma laser a pulse othamanga kwambiri (okhala ndi ma frequency opitilira 40 pulses pa sekondi) kwathandiza kugwiritsa ntchito kwambiri kuwotcherera malo a laser posonkhanitsa ndi kuwotcherera zinthu zazing'ono ndi zazing'ono popanga zinthu zodziyimira pawokha. Powotcherera zinthu zazing'ono zamagetsi zomwe zimafuna malo ang'onoang'ono omwe amakhudzidwa ndi kutentha—monga kulumikizana pakati pa galasi ndi chitsulo, kulumikizana kwa maulumikizidwe m'mabwalo a semiconductor omwe amakhudzidwa ndi kutentha, komanso kulumikizana pakati pa zitsulo zosiyanasiyana mu mawaya—wotcherera malo a laser ndi wopindulitsa kwambiri kuposa njira zachikhalidwe zowotcherera malo (monga, kuwotcherera malo otsutsa), okhala ndi ma weld osaipitsidwa komanso mtundu wapamwamba wa kuwotcherera. Chithunzi 6-60 chikuwonetsa chitsanzo chogwiritsira ntchito kuwotcherera malo a laser popanga magetsi agalimoto: laser ya 500W solid-state pulse imapanga ma weld anayi ofanana ndi ma pulse othamanga kwambiri.
Pochita ntchito yolumikiza malo olondola kwambiri pa ma microstructure pogwiritsa ntchito mphamvu ya pulse yambiri, ma laser a pulsed Nd:YAG ali ndi ubwino waukadaulo komanso wachuma. Mu ntchito zambiri zolumikizira malo ogwirira ntchito m'mafakitale, ma laser a pulsed solid-state okhala ndi mphamvu yapakati ya 50W ndi mphamvu ya pulse yoposa 2kW amagwiritsidwa ntchito. Laser imatha kugwira ntchito mwachindunji pa workpiece kudzera mu ulusi wa optical kapena ma lens ophatikizana.
Kuwotcherera malo pogwiritsa ntchito laser kungagwiritsidwe ntchito pazinthu zosiyanasiyana. Mwachitsanzo, powotcherera mabatire a Li pogwiritsa ntchito Nd:Ukadaulo wowotcherera malo a laser wa YAGKulumikiza zitsulo zosiyanasiyana n'kothandiza kwambiri kuposa TIG welding ndi resistance spot welding. Makamaka, popeza ulusi wa kuwala umagwiritsidwa ntchito kutumiza ma laser panthawi yopanga, ndikosavuta kusuntha mwachangu komanso mosinthasintha pakati pa mabenchi osiyanasiyana ogwirira ntchito.
Mwachidule, laser spot welding ili ndi makhalidwe awa:
- Ndi kuwonjezeka kwa mphamvu ya laser, kukula kwa pamwamba pa malo olumikizirana kumasinthasintha mmwamba ndi pansi, pomwe kukula kwa pamwamba pa malo olumikizirana ndi pansi kumawonjezeka pang'onopang'ono. Kusintha kwa mawonekedwe a malo olumikizirana sikuonekeratu. Pamene nthawi ikuwonjezeka, kukula kwa malo olumikizirana kumawonjezeka mwachangu, ndipo kuchuluka kwa kusintha kwa kukula kwa pamwamba pa malo olumikizirana kumakhala kwakukulu kuposa kwa mainchesi apamwamba ndi otsika. Kusintha kwa kuchuluka kwa defocus kumakhudza kwambiri kukula kwa malo olumikizirana. Kumasintha mwachindunji mainchesi a malo ndi kuchuluka kwa mphamvu ya laser, ndipo zotsatira zonse za zinthu ziwirizi zimatsimikiza kukula kwa malo olumikizirana.
- Ngati kuwala kwa laser kwalowa mokwanira, pamakhala kutsetsereka koonekeratu pamwamba pa laser spot weld. Mphamvu ya laser ikawonjezeka komanso nthawi yake, kutsetsereka kwa malo a laser kumawonjezeka. Pamene kutalika kapena kukula kwa mpata kuli kwakukulu, pansi pake pakhoza kuwonetsanso kupindika.
- Pamene mpata ukuwonjezeka, kusintha konse kwa malo owetera, kutsika kwapakati, ndi kukhazikika kwa magetsi kumakhala koonekeratu. Malo osakanikirana amachepa, ndipo mphamvu imachepa mofulumira. Pakadali pano, pakuwotcherera ma resistors, mabatire, ndi gawo la zamagetsi, njira yowotcherera malo awiri nthawi imodzi imagwiritsidwa ntchito kwambiri, zomwe nthawi zambiri zimagwiritsa ntchito kapangidwe ka magwero awiri a kuwala kwa laser.
Nthawi yotumizira: Okutobala-27-2025
