Bơm ECD-V - P - Determining the Injection Timing

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

The engine ECU determines the "Target Injection Timing" by using the signals received from the various sensors to correct the "Basic Target Injection Timing" This is calculated from the engine speed and accelerator position The

"Actual Injection Timing" is also calculated, based on the crankshaft angle standard position signal (TDC signal) In order to make the "Actual Injection Timing" match the "Target Injection Timing", the duty ratio of the timing control valve is calculated Feedback control is performed to make the injection timing the same as the target value

• Calculating the Injection Timing

Target injection timing formula

• Basic Target Injection Timing

The engine ECU calculates the engine load from the

engine speed and accelerator position signals, and

determines the "Basic Target Injection Timing" The

higher the engine speed, or the larger the accelerator

position, the longer the advance

Target Injection Timing = Basic Target Injection Timing + Intake Air Pressure Correction + Coolant Temperature Correction + Intake Air Temperature Correction

1 Determining the Injection Timing

The engine ECU compares the "Target Injection Timing" and "Actual Injection Timing" that have been calculated It then performs duty actuation on the timing control valve (TCV) in order to match the two timing values As a result, the injection pump roller ring turns, and the injection timing changes

2 Injection Timing Control Method

Crankshaft Position Signal

Crankshaft Position Signal

Engine Speed Sensor Signal

Target Injection Timing

Actual Injection Timing

Signal from Engine ECU

Engine Speed Sensor Signal

Signal from Engine ECU

(Retard Condition)

(Actuating the Advance Side)

Actual Injection Timing

Target Injection Timing

Transfer

Retard

Timing Control Valve

(Duty Ratio: Large) [Present Condition]

(Duty Ratio: Medium) [After Control]

#0

#0

Injection Timing Control

Timing Control Valve Advance

In addition to fuel injection volume and timing control, the ECD system performs other types of control to enable the comfortable operation of the engine and the vehicle

• Idling Speed Control

• EGR Control

• Intake Restriction Control

• Glow Control

• Others

3 Various System Controls

Main System Controls

This control function minimizes the variation in the idling speed caused by changes in the engine load A

"Target Speed" is calculated to meet the engine and driving conditions, which is used to control speed when the engine is idling.

The engine ECU detects the "Refrigerant Temperature, Shift Position, Air Conditioner Operation" signals, and compares the calculated "Target Speed" with the engine speed (engine speed sensor signal) at that time If the engine speed is different, the fuel injection volume is adjusted, and feedback control is performed in order to match it with the target idling speed.

• Engine speed is lower than target speed - - - -Injection volume is increased

• Engine speed is higher than target speed - - - -Injection volume is decreased

The "Target Engine Speed" for each engine

condition has already been stored in the engine ECU

memory When the ECU receives information about

the engine conditions from the sensors and

switches, it searches its memory and determines

the appropriate target value.

4 Idling Speed Control (ISC)

Detection of Idling Conditions

Idling Speed Control