2012年10月5日星期五

VTEC的彻底进化:HONDA AVTEC系统

See the diagram of the questions, If I believe that the vast majority of readers will not conceal his inner excitement, "Advanced VTEC" the words of the cover that red ornaments from the engine, they will know that it is the latest evolution of the VTEC system works. VTEC system since its introduction in 1989, has gone through the past two decades has seen its best days, early from the most complete performance DOHC VTEC, and then later in order to improve the fuel economy of the VTEC-E, and the first time in K20A variable valve timing system VTC aids as the i-VTEC system several upgrades, today, Honda improve their VTEC, but before this time is different, the big change completely beyond merely adding a "Advanced "so simple an English.AVTEC system, changes can be regarded as its make changes valve lift device. In the past, in order to change the valve lift at different speeds, Honda engineers are arranged on each valve camshaft three cam do with ordinary camshaft layout, the three level and open the overlap angle different cam are responsible with low rpm and high rpm valve opening depth between the cam and the valve at the same time adding a rocker switch what group of rocker oil pressure change reaches the switching speed of the instant, the original can be independent The activities of the two groups rocker tied to a cam driven by high-angle, so that the valve opening depth increases, this is the easiest VTEC System Works. When Honda the previous improvements VTEC system, did not this work too many adjustments and changes, improvements for the first time can be regarded as a low-level of improvement, the two intake valves per cylinder can occur one and a half to open a full or two of full actuation effect, which is considered from the fuel economy VTEC-E system, but the first to be equipped with the system is the F-series engine. To the the K20A era Integra Type-R (DC5) and CR-V, the second VTEC system evolution, Honda K series engine joined the VTC system for changes in the camshaft drive end, in order to achieve the valve change the function of the timing, but the i-VTEC commonly known as the black top and red top models are totally different in the layout of the gas distribution, the former only the intake camshaft with VTEC system, while the red roof intake and exhaust valve lift possess changes in the system.On the left, is the layout of the new VTEC system, the starker past. The image on the right is driven steplessly change gear for moving the transmission device.
Recalled some VTEC change history, start simple introduction of the the AVTEC concept, as mentioned above, the VTEC system between the camshaft and valve rocker arm to do the work to switch driven by hydraulic embolism or high or low cams intervention, but AVTEC is completely different from its complex structure of the valve rocker has been greatly simplify, the new system the rocker functionality has become relatively single, rocker internal nor any embolization device. Represented in the following figure, the Honda engineers originally complex rocker to give up, the variable part of the direct production into a similar camshaft sets of bodies wrapped camshaft, including institutions can be independent of the camshaft rotation realize different speed through a simple, not equal to the thickness of the slider engaged with the different heights of the cam, and the slider thickness variation is directly transmitted to the rocker, in order to achieve the valve lift changes.

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