Hyundai Palisade: Exhaust Emission Control System / CVVT (Continuous Variable Valve Timing) System
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 consists of the CVVT Oil Control Valve (OCV) which supplies the
engine oil to the cam phaser or takes out the engine oil from the cam phaser
in accordance with the ECM PWM (Pulse With Modulation) control signal, the CVVT
Oil Temperature Sensor (OTS) which measures the engine oil temperature, and
the Cam Phaser which changes the cam phase by using the hydraulic force of the
engine oil.
The engine oil which is supplied from the CVVT oil control valve changes 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.
It increases the retarded amount compared to the default state to expand the
operating range of the variable valve timing system.
The cam phase is fixed mechanically so that it is locked at the middle position.
|
▷Effect
Improves fuel efficiency by approx. 1.7%.
Expands the intake CVVT operating range.
(Increases the retarded amount by up to 30° compared to the default state.)
∇
LIVC (Late Intake Valve Close)
∇
1. Improves fuel efficiency by reducing pumping loss.
2. Improves knocking characteristics by reducing compression ratio.
|
|
Default position : Middle
CVVT operates in advanced / retarded directions.
|
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.
• |
The variable force solenoid (VFS) changes its force depending
on the PWM duty to control the stroke of the OCV.
|
• |
It also controls the lock, unlock, advanced, retarded, and holding
functions.
|
|
1. |
Intake CVVT
|
2. |
Exhaust CVVT
|
[CVVT System Mode]
(1) Low Speed / Low Load
|
(2) Part Load
|
|
|
(3) Low Speed / High Load
|
(4) High Speed / High Load
|
|
|
Driving Condition
|
Exhaust Valve
|
Intake Valve
|
Valve Timing
|
Effect
|
Valve Timing
|
Effect
|
(1) Low Speed
/Low Load
|
Completely Advance
|
* Valve Under-lap
* Improvement of combustion stability
|
Completely Retard
|
* Valve Under-lap
* Improvement of combustion stability
|
(2) Part Load
|
Retard
|
* Increase of expansion work
* Reduction of pumping loss
* Reduction of HC
|
Retard
|
* Reduction of pumping loss
|
(3) Low Speed
/High Load
|
Retard
|
* Increase of expansion work
|
Advance
|
* Prevention of intake back flow (Improvement of volumetric efficiency)
|
(4) High Speed
/High Load
|
Advance
|
* Reduction of pumping loss
|
Retard
|
* Improvement of volumetric efficiency
|
Schematic diagrams
Variable Force Solenoind (VFS) |
Harness Connector
CVVT Oil Control Valve (OCV) |
Harness Connector
Repair procedures
Variable Force Solenoind (VFS) |
Refer to Engine Control / Fuel System - "E-CVVT Motor"
CVVT Oil Control Valve (OCV) |
Refer to Engine Control / Fuel System - "CVVT Oil Control Valve (OCV)"
Variable Force Solenoind (VFS) |
Refer to Engine Control / Fuel System - "E-CVVT Motor"
CVVT Oil Control Valve (OCV) |
Refer to Engine Control / Fuel System - "CVVT Oil Control Valve (OCV)"
Variable Force Solenoind (VFS) |
Refer to Engine Control / Fuel System - "E-CVVT Motor"
CVVT Oil Control Valve (OCV) |
Refer to Engine Control / Fuel System - "CVVT Oil Control Valve (OCV)"
Description and operation
Description
The catalytic converter of the gasoline engine is a three way catalyst. It oxidizes
carbon monoxide and hydrocarbons (HC), and separates oxygen from the oxides
of nitrogen (NOx)...
Other information:
Specifications
Fuel Delivery System
Items
Specification
Fuel Tank
Capacity
71L (18.7 U.S. gal., 75.0 U.S.qt., 61.7 lmp.qt.)
Fuel Filter
(Built into fuel pump assembly)
Type
Paper type
Fuel Pressure Regulator
(Built into fuel pump assembly)
Regulated Fuel Pressure
360 - 400 kPa (3...
Fan speed control
1. Press the rear climate control button
of the front climate control system.
2. The fan speed can be set to the
desired speed by pushing the fan
speed control button. The higher
the fan speed is, the more air is
delivered. Pressing the OFF button
turns off the fan...