Variable
valve control system, such as the OBD2 Scanner Code Valvematic Honda VTEC, Toyota, Nissan
the VVEL and BMW Valvetronic and needed continuous transformation valve
lift. Addition to the continuously variable cam phase, they seem to have very advanced. But the distance of the word "perfect" there is a very long distance. The
ideal variable technology should be unrestricted and flexible transform
valve lift, in other words, that is, at any time, there should be
corresponding to the valve lift so as to achieve the desired combustion.
Nowadays any mechanical system is not able to achieve this level of function. Some
developers try to develop electromagnetic valve structure, but also
facing some technical problems, such as the size and weight of the
institutional problems, cost, reliability, and fuel consumption.
But
entered the 1990s as a VVT pioneer Fiat sees traditional mechanical
structure VVT lack of mobility and responsiveness, the research focus
to a more flexible and accurate control of electro-hydraulic control
system. After
overcoming many difficulties, the 2009 Geneva Motor Show, Fiat
officially released its variable valve technology research: Multiair
electro-hydraulic intake system. Their assembly the 1.4 FIRE series engine and the subsequent occurrence the 900CC-cylinder engine.
There is no doubt, MultiAir is the most flexible and accurate VVT system. Multiair
electrically controlled hydraulic intake system structure corresponding
to the different load state design for the five kinds of conditions, in
addition to the length of the basic open time, the head outside the low
transition, it can in the MaxiScan OBD2 Scanner intake stroke in the valve opening time
adjustment.
Analysis
of traditional DOHC Engine Valve DOHC VVT diagram we all know, the
ordinary engine valve train driven by a cam on the camshaft, valve to
open and close the mechanical rhythm, the accelerator pedal by the
intake manifold a throttle valve to adjust the flow rate of air. For
engine valve timing and lift technology, the size of the valve opening
(stroke), the timing (timing) can be determined by the camshaft and
control mechanism.
MultiAir
the biggest feature is pioneering the use of electronically controlled
hydraulic control system to drive the valve timing and lift, it is
driven by the camshaft through a set of electromagnetic hydraulic valve,
stepless adjustable intake valve lift and timing ,
though still is a structure of four valves OBDII Circuit Board per cylinder, but abolished
the side of the intake valve camshaft, and retain only the side of the
exhaust valve camshaft to drive intake and exhaust valves. Since
the valve opening degree and opening time are arbitrary adjustable, so
the system and BMW Valvetronic can be directly closed by the valve
opening size to control the flow rate of air therefore also canceled
throttle. Exhaust valve camshaft directly promote the intake valve through a set of solenoid hydraulic system for precise control.
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