Rubber shims yana dakatar da girgiza kafin ya fara. Suna daidaita injina ba tare da niƙa ƙarfe da ƙarfe ba. Suna ɗaukar girgiza wanda in ba haka ba zai iya gajiyar walda, ƙwanƙwasa ƙwanƙwasa, ko ramukan da ba daidai ba. Mun ga sun juya aikin daidaitawa na mintuna 30 zuwa gyara na daƙiƙa 90 - kuma sun hana $12,000 a cikin lokacin da ba a shirya ba akan layin marufi a Shandong.
Me yasa shims na roba ya zarce karfe da filastik a cikin saitin duniya na gaske
Yawancin injiniyoyi sun fara isa ga shims karfe. Sun saba. Suna da tsauri. Suna jin "karfi." Amma taurin kai ya gaza inda motsi ya kasance. Karfe yana watsa babban girgizar girgiza kai tsaye zuwa tushe. Filastik shims suna matsawa daidai gwargwado karkashin hawan keke. Rubber-musamman EPDM, NBR, ko mahadi na silicone tare da 40-70 Shore A taurin-yana ba da jujjuyawar sarrafawa. Gwajin gwaje-gwajenmu na nuna 65 Shore A EPDM shims yana rage girman girman 1.2-8 kHz da 42-68% idan aka kwatanta da tarin ƙarfe iri ɗaya.
Mun taɓa maye gurbin 17 tarkacen bakin ruwa a ƙarƙashin famfon mai sanyaya CNC tare da shims na roba 2mm guda uku. Girman girgiza ya ragu daga 7.3 mm/s RMS zuwa 2.1 mm/s RMS. Rayuwar ɗaukar famfo ta ƙara daga watanni 14 zuwa sama da watanni 33. Babu recalibration da ake bukata. Babu sake jujjuyawa bayan jiƙa na thermal. Yanayin zafin jiki ya bambanta daga -20 ° C zuwa + 80 ° C.
Rubber shims kuma suna warware daidaiton matakin inda haƙuri ke da mahimmanci. Shim mai kauri mai kauri 0.5mm tare da ± 0.03 mm kauri mai kula da kauri yana riƙe da lebur tsakanin 0.05 mm/m — ya fi yawancin faranti na ƙarfe na inji. Wannan yana da mahimmanci lokacin daidaita masu isar da wutar lantarki ta Laser ko firikwensin firikwensin gani. Ba ku niƙa, kun sanya. Ba ku auna sau biyu, kun tabbatar sau ɗaya.
Kurakurai guda uku da ke sa shim ɗin roba ya gaza—da kuma yadda za a guje su
Wasu na iya jayayya cewa roba yana raguwa da sauri a ƙarƙashin mai ko bayyanar UV. Wannan gaskiya ne — don mahallin da ba daidai ba. Mun bi diddigin gazawar da aka samu a cikin ingantattun kayan aikin ruwa na teku inda baƙar fata baƙar fata ya kumbura 300% a cikin man dizal. Amma NBR (nitrile) shims yana jure ci gaba da nutsewa cikin mai na ruwa sama da shekaru 5. EPDM yana tsayayya da ozone da yanayin yanayi. Silicone yana sarrafa hawan haifuwar tururi. Zaɓin kayan abu ba na zaɓi ba - shine yanke shawara na farko na injiniya.
Kuskure #1: Yin watsi da saitin matsawa. Roba mai rahusa yana raguwa har abada bayan kaya. Shim da ke matsawa 15% a rana ɗaya da wani 8% bayan watanni 6 ya bar kayan aiki ba su da tushe. Mun saka shims tare da saitin matsawa <5% bayan sa'o'i 70 a 70°C ta hanyar ASTM D395 B.
Kuskure #2: Amfani da shims masu goyan bayan manne kusa da tushen zafi. Manne yana laushi. Shim yana zamewa. Madadin haka, mun yanke shims zuwa ainihin sawun sawun-ba mai wuce gona da iri, babu haɗarin kwasfa. Don majalissar da aka kulle, muna ba da shawarar 1.5 × diamita na aron kusa a matsayin mafi ƙarancin faɗin shim don hana curling gefen.
Kuskure #3: Zaton duk "roba" daidai yake. Wani abokin ciniki ya gwada tef ɗin yanayin yanayin mota a matsayin shim. Ya matsa 60% a ƙarƙashin nauyin 2 MPa kuma bai taɓa murmurewa ba. Real masana'antu roba shims dauke da tensile ƙarfi ≥8 MPa da elongation ≥300%. Waɗannan lambobin ba tallace-tallace ba ne - suna gwada rahotannin da za ku iya nema kafin yin oda.
Yadda za a zabi shim roba daidai-sauri
Fara da kaya. Ba jimlar nauyi ba - amma ƙarfi a kowace santimita murabba'in ƙarƙashin aiki mai ƙarfi. Motar 500-kg da ke gudana a 2950 rpm yana ba da damuwa ~ 1.8 MPa mafi girma a wuraren hawa. Wannan yana buƙatar 60-70 Shore A NBR, mafi ƙarancin kauri mm 3.
Sannan yanayin daidaitawa:
- Bayyanar mai? Zaɓi NBR-an gwada zuwa ISO 1817 a cikin ISO VG 46 mai mai ruwa
- Rana da ruwan sama na waje? Zaɓi EPDM-UV-tsayayyen, mai jure yanayin ozone, ƙididdiga zuwa -40°C
- Matsayin abinci ko mai tsabta? Ƙayyade silicone ko farin EPDM mai dacewa da FDA, An gwada Class VI
- Turi mai zafi? Silicone kawai - barga zuwa 200 ° C ci gaba
Kauri ya zo karshe. Kada a taba tara sama da shims biyu. Kowane mu'amala yana ƙara ƙaramin zamewa kuma yana rage haɓakar damping. Idan kana buƙatar ɗaga mm 4.5, yi amfani da shim 4.5-mm ɗaya-ba 3-mm + 1.5-mm ba. Mun tara daidaitattun kauri daga 0.5 mm zuwa 10 mm a cikin haɓaka 0.5-mm, duk tsaga-yanke zuwa ± 0.02 mm haƙuri.
Siffar tana biye da aiki. Zagaye shims tsakiyar kusoshi. Shims rectangular shims yana gada faffadan sawun ƙafa. Bayanan martaba na al'ada na mutuƙar suna ɗaukar matakan da ba daidai ba -kamar waɗanda ke kan injinan bugu na gado ko kayan masaku. Muna jigilar samarwa yana gudana cikin sa'o'i 72. Samfura a cikin 48.
Rubber shims ba na'urorin haɗi ba ne - musaya ne na injiniya
Suna zaune inda makamashi ya hadu da tsari. Inda motsi ya hadu da nutsuwa. Inda daidaito ya hadu da gaskiya. Duk lokacin da shim na roba ya sha 0.3 joules na makamashin motsa jiki, yana hana ƙananan karaya a cikin welds kusa. Kowane milimita na jujjuyawar sarrafawa yana tsawaita rayuwa. Kowane maimaitawa jeri yana yanke lokacin ƙaddamarwa.
Hebei Dewell Metal Products Co., LTD yana kera shims na roba tare da na'urorin ƙarfe na bakin karfe, wanki, da tsarin anga -saboda sarrafa girgiza yana farawa a haɗin gwiwa, ba firam ba. Wurin su a gundumar Yongnian suna samar da shims ɗin da aka gwada zuwa ISO 9001: 2015, tare da gano nau'ikan nau'ikan lambobi masu yawa. Kuna samun shim-ba zato ba.
Lokaci na gaba da girgizar girgizar ƙasa, ɓacin ɓarkewa, ko daidaitawa yana cinye safiya, tambaya: Shin wannan matsala ce ta inji-ko matsalar zaɓin abu? Rubber shims ba zai gyara tushe mara kyau ko sawa ba. Amma za su gyara abin da aka tsara don: juya rashin zaman lafiya zuwa shiru, da rashin tabbas zuwa daidaito mai maimaitawa. Wannan ba dadi ba ne. Wannan shine aikin injiniyanci.
