How Do You Design an Extension Helical Spring That Won't Fail?

Njira yanu yobwerera ikuwoneka yofooka, ndi akasupe akulefuka. Izi zimabweretsa ndalama zogulira waranti, kukonzanso kwazinthu, ndi kuonongeka mbiri ya mtundu wanu.

Mapangidwe osalephera amayang'ana pa zinthu zitatu: kufotokoza kukhazikika koyenera koyambirira kwa "feel".," kupanga mbedza zolimba zomwe zimayendetsa bwino kupsinjika, ndi kusankha zinthu zoyenera katundu ndi chilengedwe. Kupeza zinthu zitatu izi moyenera ndiye chinsinsi cha kudalirika.

I've been manufacturing custom springs for over 14 zaka, and the most common failure I see in extension springs isn't in the spring's body—it's in the design process itself. Nthaŵi ina injiniya wina ananditumizira chithunzi cha kasupe kuti ndikachigwiritse ntchito m’chida chodziŵira matenda. Makinawa anali osalimba, koma masika omwe adafotokoza anali ndi vuto lalikulu loyambira. Pamene iwo ali ndi ma prototypes, the machine's small motor couldn't even begin to stretch the spring. Ntchitoyi inachedwa kwa milungu ingapo. Anangoyang'ana pa mphamvu yomaliza, completely ignoring the force needed just to get the spring started. This is why understanding the details is so critical.

What Is Initial Tension and Why Does It Matter So Much?

Masimpe aanu aatali kabotu, or it's too hard to start pulling. Izi zimapangitsa kuti katundu wanu asamvepo kanthu, mtengo, ndizovuta kwa wogwiritsa ntchito kumapeto.

Kukangana koyambirira ndi mphamvu yokhazikika, created by twisting the wire as the spring is coiled. It holds the coils tightly together and must be overcome before the spring begins to stretch. Kutchula mphamvuyi moyenera ndikofunikira pa chinthu chomwe chimagwira ntchito momwe chimafunira.

Think of it as the spring's "preload." Ndi mphamvu yobisika yomwe imapereka kasupe wowonjezera kumva kwake kwapadera. Ndidagwira ntchito yopangira kasitomala wamagalimoto omwe amapanga latch yatsopano yapakati. Mtundu woyamba udagwiritsa ntchito kasupe popanda zovuta zoyambira. Latch imakhala yomasuka komanso yozungulira. Kwa chitsanzo chachiwiri, tinawonjezera zovuta zoyamba. Latch tsopano idagwiridwa molimba, ndipo zinali zokhutiritsa, wapamwamba kwambiri "snap" pamene chinatsegula ndi kutseka. We didn't change the spring rate or the final force, kokha kukangana koyamba. That small change completely transformed the user's perception of the product's quality. It's a perfect example of how this one specification can make or break the design.

Momwe Kuvuta Kwambiri Kumayendetsedwa ndi Kufotokozera

Mphamvu imeneyi singochitika mwangozi; ndi gawo lofunika kwambiri lopanga.

• Njira Yopangira Coiling: Timapanga zovuta zoyambira panthawi yopanga. Pamene waya wamasika ukukulungidwa pa arbor, timagwiritsa ntchito kupsinjika koyendetsedwa ndi torsional kwa izo. Kupsinjika uku kumapangitsa kuti ma koyilo omalizidwa azikanikizana. Kuchuluka kwa kupsinjika komwe timagwiritsa ntchito kumawongolera mwachindunji kuchuluka kwa zovuta zoyambira.
• Why It's Important for Design: Kukangana koyambirira kumatsimikizira katundu womwe kasupe akuyamba kukulirakulira. Ngati mukufuna makina kuti mukhale otsekedwa mpaka mphamvu inayake itagwiritsidwa ntchito (ngati latch kapena chitseko cha batri), kupsinjika koyamba ndi komwe kumatsekereza. It ensures there is no looseness or play in the system when the spring is at rest.
• Malire: There is a limit to how much initial tension a spring can have, which is based on the wire diameter and coil index. Trying to specify too much initial tension can result in a spring that is brittle and prone to failure.

Why Are the Hooks the Most Common Point of Failure?

Thupi la masika anu lili bwino, koma mbedza zimangothyoka kapena kupunduka. This single weak point is causing your entire product to fail in the field, kubweretsa zobweza zodula.

Njoka ndi pamene mphamvu yonse yokoka imakhazikika kukhala yaying'ono, malo opsinjika kwambiri. Kupindika kuchokera ku thupi la kasupe kupita ku mbedza kumapangitsa kuti pakhale kupanikizika. Popanda mapangidwe oyenera komanso mpumulo wa nkhawa, mfundo imeneyi adzalephera zitsulo kutopa kalekale pamaso masika coils kuchita.

I once had a client developing a new piece of exercise equipment. Ma prototypes awo anali kulephera patangodutsa mazana ochepa chabe - mbedza pa akasupe awo otambasulidwa zinali kung'ambika.. Iwo ankagwiritsa ntchito mbedza yokhazikika ya makina, which has a sharp bend and a significant stress point. Ndinayang'ana pa ntchito yawo ndipo ndinawona kuti kasupe nayenso akukumana ndi zopindika. Ndinawalimbikitsa kuti asinthe mbedza ya crossover. Mapangidwe awa amabweretsa waya pakati pa masika, zomwe zimagawira kupsinjika kwambiri mofanana komanso kumagwira kupotoza bwino. Tinapanga ma prototypes atsopano okhala ndi ma crossover hooks, ndipo adapambana mayeso ozungulira 100,000 popanda kulephera. It's a classic case where a small change in hook geometry made all the difference.

Kusankha Hook Imene Idzapulumuka

Mapeto a kasupe ndi ofunika kwambiri kuposa apakati.

• Kumvetsetsa Zomwe Zimayambitsa Kupsinjika Maganizo: Tangoganizani mphamvu ikuyenda ngati madzi kudzera muwaya wamasika. Kupinda kwakuthwa kwa waya kuli ngati mwala wakuthwa mumtsinje—kumayambitsa chipwirikiti ndi kuthamanga kwambiri. Mu zitsulo, izi "pressure" amatchedwa kupsinjika maganizo. Popita nthawi, kupsinjika mobwerezabwereza kumapangitsa kuti mng'alu wowoneka bwino upangike panthawiyo, zomwe pamapeto pake zimabweretsa kulephera.
• Hook Design Nkhani: Mitundu yosiyanasiyana ya mbedza imayendetsa kupsinjika uku m'njira zosiyanasiyana. Lupu lathunthu ndilolimba kwambiri chifukwa lilibe mapindikidwe akuthwa ndipo kupsinjika kumayenda bwino. Chingwe cha makina ndichofala kwambiri komanso chofooka kwambiri. Crossover hook ndi mgwirizano wabwino, kupereka mphamvu yabwino kuposa mbedza ya makina.
• Kuchepetsa Kupsinjika Ndikofunikira: Akasupe atakulungidwa ndipo mbedza zimapangidwa, iyenera kutenthedwa. Njira iyi, kutchedwa kuchepetsa nkhawa, imachepetsa kupsinjika kwamkati mu waya omwe adapangidwa panthawi yopanga. Kudumpha kapena kuchita molakwika sitepe iyi ndi chitsimikizo cha kulephera kwa mbedza msanga.

Which Material Is Right for Your Spring's Environment?

Kasupe wanu amagwira ntchito bwino mu labu, but it's rusting or breaking in the real world. Kasupe wopangidwa kuchokera ku zinthu zolakwika adzalephera akakhala ndi chinyezi, kutentha kwambiri, kapena mankhwala owononga.

The material choice must match the spring's operating environment. Waya wanyimbo ndi wamphamvu komanso wotsika mtengo koma umachita dzimbiri mosavuta. Chitsulo chosapanga dzimbiri chimapereka kukana kwa dzimbiri. Kwa mikhalidwe yovuta kwambiri, ma aloyi apadera akhoza kukhala njira yokhayo.

Chitsanzo chabwino cha izi chinali kasupe omwe tidapangira kampani yomwe imapanga zida zamabwato opha nsomba m'madzi amchere. Mapangidwe awo apachiyambi adagwiritsa ntchito waya wa waya wopangidwa ndi zinc kuti apange makina a latch. Zinkawoneka bwino kuchokera m'bokosi, koma patangopita milungu ingapo panyanja, zitsulo za zinki zidzatha ndipo akasupe amadzimbirira ndi kusweka. Malo opopera mchere anali ovuta kwambiri. Yankho lake linali losavuta: tinapanganso masika omwewo pogwiritsa ntchito 302 chitsulo chosapanga dzimbiri. Zinali zokwera mtengo pang'ono, koma idathetsa vuto la dzimbiri. Phunziro ndiloti mapangidwe a kasupe ndi theka la nkhondo; sayansi yakuthupi ndi theka lina.

Chitsogozo cha Common Spring Wire Materials

The wire is the foundation of the spring's performance and lifespan.

• Waya wa nyimbo (ASTM A228): Izi ndizomwe zimagwira ntchito pakampani yamasika. It's a high-carbon steel that is very strong, ali ndi moyo wotopa kwambiri, ndipo ndi yotsika mtengo. Kufooka kwake kwakukulu ndikuti alibe pafupifupi kukana dzimbiri. Iyenera kutetezedwa ndi zokutira ngati zinc plating kapena mafuta.
• Chitsulo chosapanga dzimbiri 302/304 (Chithunzi cha ASTM A313): Ichi ndi chitsulo chosapanga dzimbiri chodziwika bwino cha akasupe. Ili ndi mphamvu yabwino komanso kukana kwa dzimbiri, kuzipanga kukhala zangwiro pazida zamankhwala, kukonza chakudya, ndi ntchito zakunja. It's more expensive than music wire.
• Chitsulo chosapanga dzimbiri 17-7 Cho (Chithunzi cha ASTM A313): Izi ndizochita bwino kwambiri, mvula-kuumitsa chitsulo chosapanga dzimbiri. Pambuyo kutentha mankhwala, imatha kufikira milingo yamphamvu yofananira ndi waya wanyimbo pomwe imakhalanso ndi kukana kwambiri kwa dzimbiri ndikuchita pa kutentha kwambiri. Amagwiritsidwa ntchito muzamlengalenga komanso mafakitale apamwamba kwambiri.

Mapeto

Chitsime chodalirika cha kasupe chimafuna kukhazikika koyenera koyambira, mbedza zolimba, ndi zinthu zoyenera. Yang'anani mbali zitatu izi pamapangidwe anu kuti muwonetsetse kuti mukugwira ntchito kwanthawi yayitali ndikupewa zolephera zomwe wamba.