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خوبصورتی اور تندرستی
دستکاری
ثقافت اور تاریخ
تفریح
ماحول
خوراک اور مشروبات
ریورس انجینئرنگ
سائنسز
کھیل
ٹیکنالوجی
پہننے والے آلات
The Two-Stroke Engine: The Piston Is the Valve
The four-stroke engine fires once every two turns and needs cams, springs and valves to breathe. Joseph Day's engine of 1891–95 fires every turn and has none of them: the piston itself opens and closes ports in the cylinder wall, and the sealed crankcase under the piston acts as a pump that pre-compresses the fresh charge.
Its own specification puts it simply: the piston *"serves as a slide-valve"*, doing away with *"eccentrics, cams, valve-rods"*. That makes it light, cheap and powerful for its size — the engine of chainsaws, mopeds and outboard motors.
This rung computes its port timing from the crank geometry and cuts the ports into a card cylinder on the slider-crank model to watch them open.
درمیانہ
About 3 hours
ہدایات
1
1
Read Day's patent
Read Day's patent
US 543,614, 'Gas Engine', Joseph Day, patented 30 July 1895. The aim is *"a gas-engine in which eccentrics, cams, valve-rods, and other positively-actuated"* parts are done away with, *"the piston itself"* serving *"as a slide-valve"*. The explosive mixture is drawn into the crankcase chamber by the up-stroke, compressed there by the down-stroke, and delivered into the upper part of the cylinder when the piston uncovers the port; the piston also uncovers the exhaust port. Day's drawing still shows a valve admitting the charge to the crankcase — look for it.
2
2
Port timing from the geometry
Port timing from the geometry
Jupyter نوٹ بک لوڈ ہو رہی ہے…
3
3
Cut ports and watch them open
Cut ports and watch them open
On the slider-crank model from the crank rung, wrap a card tube round the slider's path as a 'cylinder' and mark on it the piston crown's position at top dead centre. Cut an exhaust window starting 60 % of the stroke below that mark, and a transfer window starting 72 % down, on the opposite side.
Turn the crank slowly with the protractor underneath and note the angle at which the crown first uncovers each window, and when it covers it again. Compare with the notebook.
اس مرحلے کے لیے مواد:
گتے کی نلکی1 ٹکڑادرکار اوزار:
زاویہ پیما
پیمانہ
پکی سیاہی کا مارکر4
4
History and context
History and context
**US 543,614, 'Gas Engine', Joseph Day, patented 30 July 1895.** Day was an engineer in Bath, England, and had patented crankcase compression in Britain before this US patent; the two-stroke spread quickly to motorcycles and small boats.
**Honest limits.** The ports are open together, so some fresh charge escapes with the exhaust — wasteful and polluting in a carburetted engine. The crankcase carries the charge, so lubricating oil is usually mixed into the fuel and burned. The two-stroke survives where power for its weight matters more than economy.
مواد
1- 1 ٹکڑاپلیس ہولڈر
درکار اوزار
3- پلیس ہولڈر
- پلیس ہولڈر
- پلیس ہولڈر
متعلقہ بلیو پرنٹ
یہ بلیو پرنٹ علم بانٹتے ہیں — تکنیک، مواد یا اصول
Otto Four-Stroke Engine
Martin کی طرف سے
طبیعیات
46
0
0
0
0
0
The Crank and the Flywheel: Smoothing One Bang in Two Turns
Martin کی طرف سے
میکانکس
13
0
0
0
0
0
The Piston Ring: Sealed by the Gas It Holds Back
Martin کی طرف سے
میکانکس
11
0
0
0
0
0
The Carburettor: A Venturi, a Jet and a Float
Emma کی طرف سے
میکانکس
11
0
0
0
0
0
Roots Blower
Karen کی طرف سے
میکانکس
39
0
0
0
0
0
CC0 پبلک ڈومین
یہ بلیو پرنٹ CC0 کے تحت جاری کیا گیا ہے۔ آپ اجازت لیے بغیر اس کام کو نقل، ترمیم، تقسیم اور کسی بھی مقصد کے لیے استعمال کرنے کے لیے آزاد ہیں۔
میکر کی حمایت کریں ان کے بلیو پرنٹ کے ذریعے پروڈکٹس خرید کر جہاں وہ میکر کمیشن وینڈرز کی طرف سے مقرر، کماتے ہیں، یا اس بلیو پرنٹ کی نئی تکرار بنائیں اور آمدنی شیئر کرنے کے لیے اسے اپنے بلیو پرنٹ میں کنکشن کے طور پر شامل کریں۔