AIR CHARGING SYSTEM [SKYACTIV-D 2.2]

id0113z7706400

Purpose, Outline

• To realize low emission, low fuel consumption, high torque, and high response, either one of the two turbochargers is used depending on the driving range.

• To attain efficient, high boost pressure in various driving ranges, two-stage boost is performed in the low engine speed range using the large-type turbocharger and the small-type turbocharger, and boost is performed in the high engine speed range only using the large-type turbocharger.

System diagram

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Structure

• The two-stage boost system consists of the following parts.

Part name

Reference

Turbocharger

Large-type turbocharger

(See TURBOCHARGER [SKYACTIV-D 2.2].)

Small-type turbocharger

Compressor bypass valve

Compressor bypass valve actuator

Regulating valve

Regulating valve actuator

Variable turbine geometry turbocharger actuator

Compressor bypass solenoid valve

(See COMPRESSOR BYPASS SOLENOID VALVE [SKYACTIV-D 2.2].)

Check valve

(See CHECK VALVE [SKYACTIV-D 2.2].)

Charge air cooler

(See CHARGE AIR COOLER [SKYACTIV-D 2.2].)

Part name	Reference
Turbocharger	Large-type turbocharger	(See TURBOCHARGER [SKYACTIV-D 2.2].)
Small-type turbocharger
Compressor bypass valve
Compressor bypass valve actuator
Regulating valve
Regulating valve actuator
Variable turbine geometry turbocharger actuator
Compressor bypass solenoid valve	(See COMPRESSOR BYPASS SOLENOID VALVE [SKYACTIV-D 2.2].)
Check valve	(See CHECK VALVE [SKYACTIV-D 2.2].)
Charge air cooler	(See CHARGE AIR COOLER [SKYACTIV-D 2.2].)

Operation

• The two-stage boost system is divided between the large-type turbocharger and small-type turbocharger for control in mainly 3 regions.

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1. Low engine speed range

• Because the amount of the exhaust gas introduced to the turbine in the low engine speed range is low, boost pressure is assured by connecting the small-type turbocharger and the large-type turbocharger in tandem and having the air charged by the large-type compressor further charged at the small-type compressor, and low emission, low fuel consumption, high torque, and high response are achieved.

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2. Middle engine speed range

• In the range bordering where the operation switches between the two turbochargers, the regulating valve opening angle is controlled according to the conditions. High pressure boost is maintained by controlling the amount of exhaust gas introduced to the small-type turbocharger.

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3. High engine speed range

• In the high engine speed range, only the large-type turbocharger performs air charging because a larger amount of air is required. By circumventing the small-type turbocharger, intake air resistance is small, and the charged air is efficiently taken in.

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