y*******n
发帖数: 10103 | |
y*******n
发帖数: 10103 | 2 lift、timing都能控制，而且可以每气缸独立控制，控制速度也很快。
结构也比较简单，不知道能承受多高的RPM。 |
c*********r
发帖数: 19468 | 3 theoretically better than Valvetronic & VVEL
Valvetronic & VVEL are DOHC with an extra control shaft
Multiair is SOHC without any extra control shaft
intake valves are controlled with a hydraulic mechanism
the system has even more freedom (e.g. you can indpendently operate each
cylinder. think about it, that means with some modifications for the exhaust
side
you can even use this system to achieve cylinder shut-off, as an example
although FIAT doesn't mention this)
the down side is: the operatio
【在 y*******n 的大作中提到】
: lift、timing都能控制，而且可以每气缸独立控制，控制速度也很快。
: 结构也比较简单，不知道能承受多高的RPM。
|
y*******n
发帖数: 10103 | 4 恩，液压系统的可靠性是个问题，漏油就猥琐了。
我觉得这个系统还是挺有创意的，用比较简单的方法实现了很多功能，ECU要做的东西
更多了，我看了一本杂志，好像现在有上双核、64bit的趋势。
exhaust
【在 c*********r 的大作中提到】
: theoretically better than Valvetronic & VVEL
: Valvetronic & VVEL are DOHC with an extra control shaft
: Multiair is SOHC without any extra control shaft
: intake valves are controlled with a hydraulic mechanism
: the system has even more freedom (e.g. you can indpendently operate each
: cylinder. think about it, that means with some modifications for the exhaust
: side
: you can even use this system to achieve cylinder shut-off, as an example
: although FIAT doesn't mention this)
: the down side is: the operatio
|
c*********r
发帖数: 19468 | 5 yes, this one is really flexible
I once watched a demo. they can even operate the two intake valves
independently
open them twice per intake stroke, or some other crazy things...
let's say this way:
traditionally, the profile of the valves is mainly determined by the shape
of the cams
(the modulation of the hydraulic lifters or whatever is basically passive)
with valvetronic/VVEL, you add extra modulation which is gained from the
control shaft
but it's still hard to modulate each individual valv
【在 y*******n 的大作中提到】
: 恩，液压系统的可靠性是个问题，漏油就猥琐了。
: 我觉得这个系统还是挺有创意的，用比较简单的方法实现了很多功能，ECU要做的东西
: 更多了，我看了一本杂志，好像现在有上双核、64bit的趋势。
:
: exhaust
|
c*********r
发帖数: 19468 | 6 but I'm quite worrying about the reliability
in the case of Valvetronic or VVEL, when the VVL mechanism goes wrong
the chance is you still get "normal" valve operation
just no VVL any more
but for Multiair, the intake valves probably won't open at all...
【在 c*********r 的大作中提到】
: yes, this one is really flexible
: I once watched a demo. they can even operate the two intake valves
: independently
: open them twice per intake stroke, or some other crazy things...
: let's say this way:
: traditionally, the profile of the valves is mainly determined by the shape
: of the cams
: (the modulation of the hydraulic lifters or whatever is basically passive)
: with valvetronic/VVEL, you add extra modulation which is gained from the
: control shaft
|
