作者: skyripper (rev higher feels better) 站內: Corner_Speed
標題: Re: [影片] S2k上四喉直噴
時間: Wed Feb 25 20:32:32 2004
這一篇也蠻有趣的, 我隨便翻翻大家參考看看...
原作者 Suprdave 於 honda-tech
...進氣行程時油汽順著runner高速流入汽缸頭, 然而當氣門關閉時氣體的慣性仍然
會推向氣門, 這時在氣門後方的區域會產生壓力, 當氣門重新打開時這時壓力才得以
釋放平衡(就好像這股壓力硬把空氣推入汽缸)。 問題來了, 在傳統的IM設計中,
所有的runner都是相連到蓄氣室的, 當其中一缸為進氣行程時, 被吸入油汽後的IM內
壓力降低, 這時該低壓區域為了平衡壓力(釋放真空), 必須從別的地方吸進空氣...
所以可能會透過節氣門, 亦或者是runner內於氣門後的正壓區來中和, 便抑制了我們
開始所提到的慣性進氣效應... 雖然這都決定於IM的runner長度和rod-ratio(主要跟
活塞運動速度有關) 但這可能對 power band 內的輸出造成極大的影響。
(註)我為了怕中文名稱"歧管"這個字詞混淆所以用了部分英文
IM = intake manifold = 進氣歧管
runner = 蓄氣室後方進入汽缸頭的管路
所以路徑是: 節氣門(TB) -> 蓄氣室 -> runner -> 汽缸頭
原文:
o'h ya and the guy that was talking about the manifold design is right about
the larger runners having less velocity. but it all come's down to the inertia
of the intake charge and the pressure zones created by it. (this is kind of a
long explanation but it will be easer to understand) after each intake cycle
the air in the intake runner will be traveling down the intake runner at a
high speed. when the valve closes the inertia of the air will still be forcing
it towards the valve, this will create a high pressure zone behind the valve,
when the valve opens again the pressure will be released into the cylinder
(almost like force feeding it). the problome with a single throttle body mani-
fold is the fact that all the runners are connected. when the intake cycle of
one cylinder is pulling air it creates a low preshure zone in the intake ple-
num, now the manifold wants the pressure to be even all over, so when that low
pressure zone wants to be relived of it's vacuum it will have to pull air from
somewhere else.. so it can pull air in through the throttle body which will
take the force of pulling the air.. or the runner with the high pressure zone
behind the valves can release it's pressure into the plenum, thus taken away
from our force feeding effect. although this is all dependent of the manifold
runner length and rod-ratios(piston speed) it can vary on where it takes the
most effect on the power band.
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╭┼ Origin: 玩車人的天地 ˙東吳機研站 scumotor.com.tw ┼╯ Author: skyripper從 68-169-135-112.arcdca.adelphia.net 發表
→ skyripper推：會不會太難? :p 看的懂英文的話看原文比較清楚 04/02/25