Tất cả tài liệu về bơm ECD-V (tài liệu đào tạo của Denso ECD): -Composition and Construction of ECD-V3 Pump System -Determining the Injection Timing -ECD-V Series -ECD-V4 Outline -ntake Restriction Control -Outline of Injection Ti
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The previous session covered the changes in the environment surrounding the diesel engine and described the ECD system (ECD-V series) and the common-rail system This session describes the types of systems in the ECD-V series and their system configurations
Although the injection pump has the same basic construction as the distribution type pump, the ECD-V3 includes the parts listed below due to the adoption of electronic control
• Solenoid spill valve (SPV) An actuator that controls the injection volume
• NE sensor (NE) A sensor that detects the cam position of the pump
• Fuel temperature sensor (THF) A sensor that detects the temperature of the fuel
• Correction resistor or ROM A part that corrects the injection volume and injection timing
• Timing control valve (TCV) An actuator that controls the injection timing
The V1 is the first of the ECD-V series, which appeared
in 1982 The V3, a swirl-chamber type diesel injection
system, appeared in 1985
The V3, which adopted a solenoid spill valve to control
fuel injection, enabled the control of the injection volume
on a cylinder-by-cylinder basis
Depending on the type of final injection volume
correction and the solenoid spill valve that are used,
three types of ECD-V3 are available: ECD-V3, ECD-V3
(ROM), and ECD-V3 direct-acting valve
The V4 direct-injection diesel fuel injection system for
small trucks and SUVs appeared in 1998
The V4 system, which uses an inner cam pumping mechanism, enables high-pressure injection at 1,300 bars The V5 direct-injection diesel fuel injection system for passenger vehicles appeared at about the same time The V5 system uses pilot injection to reduce the combustion noise of the engine
1-1 ECD-V Series
1-2 Injection Pump for ECD-V3
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The ECD-V4, which is based on the ECD-V3, is an electronically controlled distribution type pump that has adopted a completely new construction The combustion performance of the engine with the ECD-V4 has been improved (by atomizing the fuel into finer particles and optimizing the rise rate of the injection pressure), and providing the injection volume and injection timing with a higher level of precision and freedom With respect to the major changes that have been made from the ECD-V3, an inner cam mechanism, a highly responsive solenoid spill valve and EDU, and a correction ROM have been adopted
The ECD-V5, which is based on the ECD-V3, is a distribution type, electronically controlled fuel injection pump that offers higher injection performance and functionality It provides pilot injection to reduce the combustion noise of the engine
1-3 Injection Pump for ECD-V4
1-4 Injection Pump for ECD-V5
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The configuration of the ECD-V series system can be broadly classified into the following three systems: Intake air system, Fuel system, and Control system
Intake air system This system, which draws the air that is necessary for combustion, consists of the areas
from the air cleaner to the intake manifold
Fuel system This system, which injects the fuel that is necessary for combustion into the cylinders,
consists of the areas from the fuel tank to the injection pump and the nozzles
Control system This system, which controls the fuel injection volume and injection timing, consists of
sensors (detectors), computers, and actuators
After being filtered through the air cleaner, the intake air travels through the turbocharger and the venturi, passes through the intake manifold, and enters the cylinders
The venturi consists of a "main valve" and a "sub valve" The main valve opens and closes in unison with the accelerator pedal to draw the amount of air that is necessary for driving
The sub valve, which is located parallel to the main valve, is opened and closed by the diaphragm in order to restrict the intake air volume in accordance with the conditions of the engine
The fuel from the fuel tank travels to the fuel filter & sedimenter where it is filtered and its moisture is removed Then, it is drawn into the injection pump
As the fuel fills the injection pump, it lubricates and cools the moving parts in the injection pump After the fuel is pressurized, it is injected into the engine cylinder by the injection nozzle The excess fuel travels from the overflow valve to the return pipe and returns to the fuel tank
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2-1 Outline of Intake Air System
2-2 Outline of Fuel System
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The engine ECU uses various types of sensors to detect the engine speed, accelerator position, and switch signals These pieces of information are used for the engine ECU to determine the operating conditions of the engine and the driving conditions Then, the engine ECU calculates the fuel injection volume and the injection timing that are necessary for operating the engine in an optimal state, and actuates the valves
The control system can be broadly classified by their electrical components into the following three systems:
Sensor system, ECU, and Actuator system
Sensor system Detects the engine conditions and driving conditions and converts them into electrical
signals
ECU Performs calculations based on the signals received from various sensors and sends
signals to the actuators in order to operate the engine in an optimal condition
Actuator system Operates in accordance with the control signals received from the engine ECU
2-3 Outline of Control System
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