JDMEK4COUPE
11-04-2009, 11:15 PM
Honda's pictorial representation of the VTC mechanism illustrates very clearly the operating principle of generic VVT - ie turning the camshaft in relation to the driving sprocket. However the actual VTC mechanism is unclear from the diagram. Readers should bear in mind that the generic VVT mechanism I described on the iVTEC article is just that - generic. Different manufacturers will implement the mechanism using different details. However, the important part is the introduction of a mechanism to isolate the camshaft from its driving sprocket and which also allows the relative rotational alignment between the two to be accurately controlled and continously changed.
From what little is available from the Honda illustration, it seems that Honda may have opted to use a gear and tooth mechanism on the sprocket itself to implement the ability to rotate the sprocket in relation to the camshaft (or vice versa depending on how you look at it.)
http://asia.vtec.net/article/k20a/11_04.gif
The VTC actuator, installed on the intake camshaft, is controlled by oil pressure, to allow for dynamic and continuous valve timing to fit the load of the engine.
From what little is available from the Honda illustration, it seems that Honda may have opted to use a gear and tooth mechanism on the sprocket itself to implement the ability to rotate the sprocket in relation to the camshaft (or vice versa depending on how you look at it.)
http://asia.vtec.net/article/k20a/11_04.gif
The VTC actuator, installed on the intake camshaft, is controlled by oil pressure, to allow for dynamic and continuous valve timing to fit the load of the engine.