O'TKAZIB BERING
Mahkamlagichlarga samarali xizmat ko'rsatish uchun vida iplari to'g'risida ishchi bilimga ega bo'lish muhimdir. Ip bu silindrning ichki qismida (yong'oq) yoki tashqarida (vida) hosil bo'lgan doimiy aylanma tizma. Bu Ridge deb ataladi toji . Har bir qirg'oqning o'rtasida ildiz deb nomlangan bo'sh joy mavjud . Iplar murvat yoki yong'oqning o'qiga burchak ostida o'rnatiladi. Ushbu qiyalik burchaklar burchagi deb nomlanadi . Burchakni yuqoriga yoki o'ngga (o'ng qo'l tishli vintlar uchun) yoki chapga (chap qo'l tishli vintlar uchun) egilgan bo'lishi kerak. Ip qirralarning orasidagi "V" shaklini hosil qiladi. Ushbu "V" burchagi ipning burchagi deb nomlanadi va uni mahkamlash muhandislari tomonidan belgilanadi. Velosipedda ishlatiladigan ko'p vintli iplar 60 graduslik burchak burchagidan foydalanadilar.
Tashqi iplar (murvat) uchun o'ng qo'l ipi o'ngga, lekin ichki o'ng qo'l ipi chapga egiladi. Tashqi chap iplar uchun iplar chapga, ichki chap iplar esa o'ngga egiladi. O'ng qo'l vintini soat yo'nalishi bo'yicha torting (o'ngga). Chap qo'l vintini soat yo'nalishi bo'yicha teskari tomonga torting (chapga). Velosipedda chap qo'l iplari pastki qavs va chap pedalning haydovchi tomonida ko'rinadi. Quyidagi pedallar iplaridagi iplarning qiyaliklariga e'tibor bering.
Iplar tashqi ipning asosiy diametri va o'lchovi bo'yicha belgilanadi yoki nomlanadi . Katta diametr ip iplarining yuqori qismidagi tashqi diametrdir. Ip o'lchamlari haqiqiy o'lchovda emas, balki nominal o'lchamlarda berilgan. Aniq o'lchov nomlangan yoki nominal hajmdan biroz pastroq. Masalan, 6mm murvat 5.8mm yoki 5.9mm o'lchashi mumkin, ammo u 6mm murvat deb ataladi. Bolt o'lchamidan oldin "M" dan foydalanish, masalan, 6 mm bo'lgan murvat uchun M6 kabi. Eslatma: Bolt yoki yong'oqning boshi uchun kalit hajmi ipning hajmini aniqlash uchun ishlatilmaydi. Masalan, 6 mm x 1mm ipdagi umumiy rozetkali boshcha vintida 5 mm uzunlikdagi kalit ishlatiladi, ammo ip 5 mm deb nomlanmaydi.
Mavzu pitch ip uzunligi bo'ylab o'lchagan boshqa ramziga bir ipdan toj masofa bo'ladi. Pitch eng yaxshi o'lchash ip yordamida o'lchanadi.
"Inglizcha", "Standart", "Imperial" yoki SAE iplari bir dyuymga qancha iplarni hisoblash chastotasi bilan belgilanadi. Bu "Bir dyuym boshiga" deb nomlanadi va "TPI" deb qisqartiriladi. Metrik iplar ipning o'qi bo'ylab o'lchanadigan qo'shni ip ipidan millimetrda to'g'ridan-to'g'ri o'lchash usulidan foydalanadi. SAE ipiga misol 9/16 ″ x 20 TPI (pedal iplar). Metrik ipning misoli 10mm 1mm bo'lishi mumkin (keng tarqalgan orqa derailleur murvat). Izoh: "Standart" iplar atamasi asosan AQShda qo'llaniladi. AQShda faraz shundan iboratki, umumiy SAE tishlari "standart" dir.
Odatda, agar ip TPI deb belgilangan pitchga ega bo'lsa, u SAE ipidir va diametri kasr dyuym o'lchamlarida beriladi. Agar maydon metrik standartlarga mos keladigan bo'lsa, diametri millimetrda beriladi. Biroq, ba'zi bir ip standartlari tpi ni metrik diametr bilan aralashtiradi. Ba'zi italiyalik ishlab chiqaruvchilar metrik diametrli iplar va SAE iplari uchun tayoqlardan foydalanadilar. Masalan, "Italiya" pastki qavs ip standarti 36 mm x 24 tpi, va ba'zi Italiyada ishlab chiqarilgan orqa akslar 10 mm x 26 tpi.
Threads are sometimes identified as “fine” or “coarse.” A fine thread will have a relatively small pitch measurement, and the threads will be closer together. A coarse thread has a relatively larger pitch measurement, and the threads will be further apart. Fine pitch threads are sometimes used to make adjustments. Derailleur adjusting screws are commonly a 0.75mm pitch. A quarter of a turn on a derailleur screw advances the screw end only 0.19mm. A fine thread will have less depth as compared to a coarse thread, and consequently are easier to strip. A coarse thread is more resistant to stripping but also less efficient in transmitting torque (turning) into thread tension. Generally, a fine pitch is easier to tighten in that tension is achieved at lower torques. In the image below, two bolts of the same diameter are magnified using an optical comparator. Notice the relatively coarser threads are deeper as compared to the fine threads.
LEFT: COARSE THREAD. RIGHT: FINE THREAD
For threads to interchange and match, both the diameter and pitch must match. Another critical aspect of thread fit and interchangeability is call pitch diameter. The pitch diameter is the diameter of the thread at a point where the width across the thread and the width across the groove between threads, are equal. Pitch diameter is difficult to measure directly without special instruments such as the optical comparator. For example, you may have one bottom bracket that seems to fit a bike shell easily. However, a replacement bottom bracket of a different brand may fit the same bike tightly. It is likely the two bottom brackets vary in pitch diameter.
Even when threads are properly sized, there will be play or slop between external and internal threads when engaged. This play is normal and disappears when the fastener is tightened. The thread can be a bit larger or smaller than ideal, and yet the part will still function adequately. However, if tolerances are exceeded, the part may require excessive force to install, or the fit may be quite sloppy, and the thread may fail during tightening.
Boltlar va vintlardek turli kuchlilik turlarida tayyorlanadi. Ko'pgina sanoat murvatini belgilash va aniqlash uchun foydalaniladigan reyting tizimi mavjud. Biroq, velosiped sanoati odatda biron bir belgisiz mulkiy boltlardan foydalanadi. SAE (Avtomobil muhandislari jamiyati) tizimi murvatlarni 1-sinfdan 8-sinfgacha baholaydi. Metrik murvat "mulk sinfi", o'nlik nuqta bilan ajratilgan ikkita sonli tizim bilan birga keladi.