Kia Picanto: 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 valves in accordance with the ECM
control signal 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). CVVT improves
engine performance by reducing pump loss and internal EGR effect,
improving combustion stability and volumetric efficiency, and increasing
expansion work.
This system consists of:
–
| 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, |
–
| the CVVT Oil Temperature Sensor (OTS) which measures the engine oil temperature, |
–
| and the Cam Phaser which varies the cam phase by using the hydraulic force of the engine oil. |
The
engine oil released from the CVVT oil control valve varies the cam
phase in the direction (Intake Advance/Exhaust Retard) or in the
opposite direction (Intake Retard/Exhaust Advance) of the engine
rotation by rotating the rotor connected to the camshaft inside the cam
phaser.
The
CVVT has the mechanism of rotating the rotor vane by hydraulic force
generated by the engine oil supplied to the advance or retard chamber in
accordance with the CVVT oil control valve control.
(1) Low Speed / Low Load
| (2) Partial 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
|
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 t ...
Specifications
Specifications
Fuel Delivery System
Items
Specification
Fuel Tank Capacity 35 L (9.2 U.S. gal, 37.0 U.S. qt, ...
Other information:
Components and components location
Components
1. ESC control module connector 2. ESC control module 3. ESC bracket
Repair procedures
Removal
1.Turn ignition OFF and disconnect the negative (-) battery cable.
2.Remove the brake fluid from the master cylinder reservoir with ...
Components and components location
Component Location
1. Steering column shroud upper panel 2. Steering column shroud lower panel
Repair procedures
Replacement
Put on gloves to protect your hands.
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