Hyundai Santa Fe: Cylinder Head Assembly / CVVT & Camshaft. Description and operation
Continuous Variable Valve Timing (CVVT) system advances or retards the valve
timing of the intake and exhaust valve in accordance with the ECM control signal
which is calculated by the engine speed and load.
By controlling CVVT, the valve over-lap or under-lap occurs, which makes better
fuel economy and reduces exhaust gases (NOx, HC) and improves engine performance
through reduction of pumping loss, internal EGR effect, improvement of combustion
stability, improvement of volumetric efficiency, and increase of expansion work.
This system consist of
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the CVVT Oil Control Valve (OCV) which supplies the engine oil to the
cam phaser or runs out the engine oil from the cam phaser in accordance
with the ECM PWM (Pulse With Modulation) control signal,
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and the Cam Phaser which varies the cam phase by using the hydraulic
force of the engine oil.
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The engine oil getting out of the CVVT oil control valve varies the cam phase
in the direction (Intake Advance/Exhaust Retard) or opposite direction (Intake
Retard/Exhaust Advance) of the engine rotation by rotating the rotor connected
with the camshaft inside the cam phaser.
The CVVT has the mechanism rotating the rotor vane with hydraulic force generated
by the engine oil supplied to the advance or retard chamber in accordance with
the CVVT oil control valve control.
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The variable force solenoid (VFS) changes its force depending
on the PWM duty to control the stroke of the OCV.
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•
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It also controls the lock, unlock, advanced, retarded, and holding
functions.
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(1) Low Speed / Low Load
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(2) Part Load
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(3) Low Speed / High Load
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(4) High Speed / High Load
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Driving
Condition
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Exhaust Valve
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Intake Valve
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Valve
Timing
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Effect
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Valve
Timing
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Effect
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(1) Low Speed
/Low Load
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Completely
Advance
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* Valve Under-lap
* Improvement of combustion stability
|
Completely
Retard
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* Valve Under-lap
* Improvement of combustion stability
|
(2) Part Load
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Retard
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* Increase of expansion work
* Reduction of pumping loss
* Reduction of HC
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Retard
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* Reduction of pumping loss
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(3) Low Speed
/High Load
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Retard
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* Increase of expansion work
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Advance
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* Prevention of intake back flow (Improvement of volumetric efficiency)
|
(4) High Speed
/High Load
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Advance
|
* Reduction of pumping loss
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Retard
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* Improvement of volumetric efficiency
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Removal
1.
Disconnect the battery negative terminal.
2.
Remove the engine cover.
•
Remove the engine cover on room temperature...
Removal
•
Be careful not to damage the parts located under the vehicle
(floor under cover, fuel filter, fuel tank and canister) when
raising the vehicle using the lift...
Other information:
Vehicle Identification Number (VIN)
The vehicle identification number (VIN) is the number used in registering your
vehicle and in all legal matters pertaining to its ownership, etc.
The number is punched on the floor under the passenger seat. To check the number,
open the cover...
Adjustment
1.
Turn ignition switch OFF and disconnect the negative (-) battery cable.
2.
Remove the lower crash pad.
(Refer to Body - "Crash Pad")
3...
Categories
Speedometer
The speedometer indicates the speed of the vehicle and is calibrated in miles
per hour (MPH) and/or kilometers per hour (km/h).
Tachometer
read more