TWO-STAGE TURBO CONTROL [SKYACTIV-D 2.2]
id0140z7987800
Outline
Fuel injector (2pin type)
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• By switching the air charging between the large-type turbocharger and small-type turbocharger, driveability under a wide range of conditions and emission performance have been improved.
• The following 3 solenoid valves are driven according to the engine operation conditions to switch the air charging between the large-type turbocharger and small-type turbocharger.
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― Compressor bypass solenoid valve
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• The compressor bypass valve opens/closes according to the on/off signal from the PCM.
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― Regulating solenoid valve
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• The regulating valve opens/closes according to the duty signal from the PCM.
― Wastegate solenoid valve
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• The wastegate valve opens/closes according to the duty signal from the PCM.
Fuel injector (6pin type)
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• The PCM controls the boost pressure efficiently in the range from low engine speed to high engine speed, achieving low emission, low fuel consumption, high torque, and high response according to the following operations.
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― Either one of the large-type and small-type turbochargers is used correctly
― The opening angle of the variable nozzles for the large-type turbocharger is adjusted correctly
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• The PCM operates the following 3 actuators to obtain optimum boost pressure according to the engine operation conditions.
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― Compressor bypass solenoid valve
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• The compressor bypass valve opens/closes according to the on/off signal from the PCM.
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― Regulating valve actuator
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• The regulating valve is controlled according to the duty signal from the PCM.
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― Variable turbine geometry turbocharger actuator
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• The variable nozzle is controlled according to the signal from the PCM.
Block diagram
Fuel injector (2pin type)
Fuel injector (6pin type)
Operation
Fuel injector (2pin type)
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• The two-stage turbocharger control is divided between the large and small-type turbochargers in mainly 5 ranges.
OFF: No energization
ON: Energization (on control)
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Item
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Operation conditions
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Compressor bypass solenoid valve
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Regulating solenoid valve*1
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Wastegate solenoid valve*2
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Turbo charging condition
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(1) Engine start/partial warm-up range
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ON (open)
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Duty 0% (open)
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Duty 0% (open)
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No turbo charging
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(2) Low engine speed range
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OFF (closed)
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Duty 50—95% (closed)
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Duty 60—95% (closed)
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Two-stage turbo charging
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(3) Middle engine speed range
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OFF (closed)
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Duty 0 to 95% (closed ↔ open)
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Duty 60—95% (closed)
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Single-stage turbo charging to two-stage turbo charging based on large-type turbocharger
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(4) High engine speed range
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ON (open)
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Duty 0% (open)
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Duty 60—95% (closed)
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Single-stage turbo charging based on large-type turbocharger
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(5) Air charging control range at wastegate valve
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ON (open)
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Duty 0% (open)
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Duty 0 to 95% (closed ↔ open)
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Single-stage turbo charging based on no turbo charging to large-type turbocharger
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*1 :The required duty value to close the regulating valve is 50%, however, if it is difficult to close the regulating valve because of the exhaust gas pressure, the PCM increases the duty value.
*2 :The required duty value to close the wastegate valve is 60%, however, if it is difficult to close the wastegate valve because of the exhaust gas pressure, the PCM increases the duty value.
Fuel injector (6pin type)
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• The two-stage turbocharger control is divided between the large and small-type turbochargers in mainly 5 ranges.
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Item
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Operation conditions
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Compressor bypass valve
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Regulating valve
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Variable nozzle
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Turbo charging condition
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(1) Low engine speed range
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Fully closed
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Fully closed
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Fully open*1
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Single-stage turbo charging based on small-type turbocharger
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(2) Middle engine speed range
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Fully closed
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Fully open*1
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Fully open*1
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Two-stage turbo charging
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(3) High engine speed range
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Fully open
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Fully open
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Open↔Fully open
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Single-stage turbo charging based on large-type turbocharger
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*1 :The opening angle changes depending on the target boost pressure/exhaust pressure
