कला
सौंदर्य और कल्याण
हस्तशिल्प
संस्कृति और इतिहास
मनोरंजन
पर्यावरण
खाद्य और पेय
रिवर्स इंजीनियरिंग
विज्ञान
खेल
प्रौद्योगिकी
पहनने योग्य
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.
मध्यवर्ती
About 3 hours
निर्देश
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 नोटबुक लोड हो रही है…
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.
इस चरण के लिए सामग्री:
गत्ते की नली1 टुकड़ाआवश्यक उपकरण:
चाँदा
रूलर
पक्की स्याही का मार्कर4
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.
सामग्री
1- 1 टुकड़ाप्लेसहोल्डर
संबंधित ब्लूप्रिंट
ये ब्लूप्रिंट ज्ञान साझा करते हैं — तकनीक, सामग्री या सिद्धांत
Otto Four-Stroke Engine
Martin द्वारा
भौतिकी
46
0
0
0
0
0
The Crank and the Flywheel: Smoothing One Bang in Two Turns
Martin द्वारा
यांत्रिकी
9
0
0
0
0
0
The Piston Ring: Sealed by the Gas It Holds Back
Martin द्वारा
यांत्रिकी
7
0
0
0
0
0
The Carburettor: A Venturi, a Jet and a Float
Emma द्वारा
यांत्रिकी
8
0
0
0
0
0
Roots Blower
Karen द्वारा
यांत्रिकी
39
0
0
0
0
0
CC0 पब्लिक डोमेन
यह ब्लूप्रिंट CC0 के तहत जारी किया गया है। आप बिना अनुमति माँगे इस कार्य को किसी भी उद्देश्य के लिए कॉपी, संशोधित, वितरित और उपयोग करने के लिए स्वतंत्र हैं।
उनके ब्लूप्रिंट के माध्यम से उत्पाद खरीदकर मेकर का समर्थन करें जहाँ वे मेकर कमीशन कमाते हैं जो विक्रेताओं द्वारा निर्धारित होता है, या इस ब्लूप्रिंट का नया संस्करण बनाएँ और राजस्व साझा करने के लिए इसे अपने ब्लूप्रिंट में कनेक्शन के रूप में शामिल करें।