A Discussion on Valve Dynamic and Noise via Order Tracking and Enhanced Time Analysis
| Autor: | Han-Hsueh Liu, 劉翰學 |
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| Rok vydání: | 2004 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 92 This essay intends to delve into the order energy relations of valve dynamic behavior, revolving speed and noise with order tracking analysis technology. This study uses four-stroke automobile engine, with the exhaust volume in 125 cc as well as with the valve model in OHC single intake valve and single exhaust valve as the experimental platform. Furthermore, “Time Domain Averaging” technology is introduced into the “Order Tracking Analysis” technology as well as “Signal Enhancement” is applied to analyze the relations of valve dynamic behavior, noise and revolving speed more accurately. From 3490rpm to 6480rpm, these dynamic behaviors are expected to follow a prescribed motion which is determined by the cam shape ;In the measurement of 8830rpm, it is found that the valve produces floating phenomenon about 0.26mm; In the measurement of 10100rpm,we can find that the first bounce is caused by increased inertia force, in the meantime, the valve produces floating phenomenon about 0.56mm; When the tested bench is driven at 10200 rpm, the second bounce is produced by the higher impact velocity, meanwhile, the valve produces floating phenomenon about 0.68mm. The experimental results then reveal that the noise of engine along with the noise produced from a bumping of the valve against the valve seat will create the coupled phenomenon on order spectrum under a high revolution, thus making the noise value enhanced abruptly while the bumping of valve in high speed against the valve seat will result in producing higher order of noise. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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