可變氣門(mén)配氣相位和氣門(mén)升程電子控制系統(tǒng)VTEC技術(shù)解析

1、可變氣門(mén)配氣相位和氣門(mén)升程電子控制系統(tǒng)VTEC技術(shù)解析the camshaft and rocker arms, but unlike ordinary engine is the number and control method of cam and rocker arm. Medium and low speed with a small angle of the cam, two valve timing and lift different at low speed, this time a valve lift is very small, almost do not partic

2、ipate in the intake process, the air intake channel basically the equivalent of two valve engine, but due to the flow direction of an intake air barrier gas cylinder center, so it can produce intake eddy current, strong for low speed, especially in the cold car conditions conducive to improving the

3、mixture uniformity, increases the burning rate and decrease the effect of wall surface chilling effect and clearance, making the combustion more fully, thereby improving the economy, and significantly reduce HC and CO emissions; and at high speeds. Through to VTEC solenoid valve to control the hydra

4、ulic oil, so that the two intake rocker arms are connected as a whole and the intake cam from the opening of the longest and largest lift to drive the valve, this time two inlet valve according to the cam profile synchronization. Compared with the low speed operation, greatly increasing the inlet fl

5、ow area and opening duration, so as to improve the power of the engine at high speed. This two kinds of entirely different performance curve of output, Honda engineers so that they are implemented in the same engine, and vividly described as the usual soft driving and wartime intense driving.But VTE

6、C system for gas distribution phase change is still the stage, that is to say the change with gas phase only at a speed jump, but not in a speed range of continuous variable. In order to improve the performance of VTEC system, Honda constantly innovate, introduced the i-VTEC system.Simply put, the i

7、-VTEC system is based on VTEC, added a called VTC (Variable timing control variable timing control device) - a group of inlet valve camshaft timing variable control mechanisms, i.e. i-VTEC=VTEC VTC. At this point, the exhaust valve timing and overlapping time open is variable, controlled by VTC, int

8、o the VTC mechanism so that the engine can have suitable gas distribution phase in large range of speed, which improves the performance of the engine to a large extent.A typical VTC system by the VTC actuator, VTC oil control valve, all kinds of sensors and ECU components. The VTC actuator, VTC oil

9、control valve can generate action according to the ECU signal, the phase of inlet camshaft continuous change. VTC makes the valve overlap time more accurately, ensure the intake valve and exhaust valve, the best lap time, can improve engine power 20%.由本田汽車(chē)開(kāi)發(fā)的VTEC是世界上第一款能同時(shí)控制氣門(mén)開(kāi)閉 時(shí)間及升程兩種不同情況的氣門(mén)控制系統(tǒng)，現(xiàn)

10、在已演變成i-VTECo i-VTEC發(fā)動(dòng)機(jī)與普通發(fā)動(dòng)機(jī)最大的不同是，中低速和高速會(huì)用兩組 不同的氣門(mén)驅(qū)動(dòng)凸輪，并可通過(guò)電子系統(tǒng)自動(dòng)轉(zhuǎn)換。此外，發(fā)動(dòng)機(jī)還 可以根據(jù)行駛工況自動(dòng)改變氣門(mén)的開(kāi)啟時(shí)間和提升程度，即改變進(jìn)氣 量和排氣量，從而達(dá)到增大功率、降低油耗的目的。韓國(guó)的汽車(chē)工業(yè)一向不以技術(shù)先進(jìn)聞名，所以所用技術(shù)也多是借鑒 了德、日等國(guó)的經(jīng)驗(yàn)，而CVVT正是在VVT-i和 i-VTEC的基礎(chǔ)上研 發(fā)而來(lái)。以現(xiàn)代汽車(chē)的CVVT引擎為例，它能根據(jù)發(fā)動(dòng)機(jī)的實(shí)際工 況隨時(shí)控制氣門(mén)的開(kāi)閉，使燃料燃燒更充分，從而達(dá)到提升動(dòng)力、降 低油耗的目的。但是CVVT不會(huì)控制氣門(mén)的升程，也就是說(shuō)這種引 擎只是改變了吸、排

11、氣的時(shí)間。VTEC發(fā)動(dòng)機(jī)每缸有4氣門(mén)（2進(jìn)2排）、凸輪軸和搖臂等，但與普通 發(fā)動(dòng)機(jī)不同的是凸輪與搖臂的數(shù)目及控制方法。中、低轉(zhuǎn)速用小角度 凸輪，在中低轉(zhuǎn)速下兩氣門(mén)的配氣相位和升程不同，此時(shí)一個(gè)氣門(mén)升 程很小，幾乎不參與進(jìn)氣過(guò)程，進(jìn)氣通道基本上相當(dāng)于兩氣門(mén)發(fā)動(dòng)機(jī)， 但是由于進(jìn)氣的流動(dòng)方向不通過(guò)氣缸中心，故能產(chǎn)生較強(qiáng)的進(jìn)氣渦 流，對(duì)于低速，尤其是冷車(chē)條件下有利于提高混合氣均勻度、增大燃 燒速率、減少壁面激冷效應(yīng)和余隙的影響，使燃燒更加充分，從而提 高了經(jīng)濟(jì)性，并大幅降低了 HC、CO的排放；而在高轉(zhuǎn)速時(shí)，通過(guò) VTEC電磁閥控制液壓油的走向，使得兩進(jìn)氣搖臂連成一體并由開(kāi)啟 時(shí)間最長(zhǎng)、升程最大的進(jìn)氣

12、凸輪來(lái)驅(qū)動(dòng)氣門(mén)，此時(shí)兩進(jìn)氣門(mén)按照大凸輪的輪廓同步進(jìn)行。與低速運(yùn)行相比，大大增加了進(jìn)氣流通面積和開(kāi)啟持續(xù)時(shí)間，從而提高了發(fā)動(dòng)機(jī)高速時(shí)的動(dòng)力性。這兩種完全不同性 能表現(xiàn)的輸出曲線，本田的工程師使它們?cè)谕粋€(gè)發(fā)動(dòng)機(jī)上實(shí)現(xiàn)了， 并且形象地稱(chēng)之為“平時(shí)的柔和駕駛”與“戰(zhàn)時(shí)的激烈駕駛”。但是VTEC系統(tǒng)對(duì)于配氣相位的改變?nèi)匀皇请A段性的，也就是說(shuō)其改 變配氣相位只是在某一轉(zhuǎn)速下的跳躍，而不是在一段轉(zhuǎn)速范圍內(nèi)連續(xù) 可變。為了改善VTEC系統(tǒng)的性能，本田不斷進(jìn)行創(chuàng)新，推出了 i-VTEC 系統(tǒng)。簡(jiǎn)單地說(shuō)，i-VTEC系統(tǒng)是在VTEC系統(tǒng)的基礎(chǔ)上，增加了一個(gè)稱(chēng)為 VTC（Variable timing control4可變正時(shí)控制”）的裝置 一組進(jìn)氣門(mén) 凸輪軸正時(shí)可變控制機(jī)構(gòu)，即i-VTEC=VTEC+VTC。此時(shí)，排氣閥 門(mén)的正時(shí)與開(kāi)啟