CONSTRUCTION
Throttle Body
A DC motor type throttle body in which the diesel throttle control motor and the throttle position sensor are integrated is used.
In the diesel throttle control motor, a DC motor is used to control intake throttle.
A non-contact type throttle position sensor is used in the throttle body.
| *1 | Throttle Valve | *2 | Throttle Control Motor |
| *3 | Throttle Position Sensor | - | - |
Turbocharger
Variable nozzle vane type turbocharger consists primarily of a turbine, nozzle vane, unison ring, nozzle ring, and turbocharger variable nozzle motor (DC motor and nozzle vane position sensor).
This turbocharger has realized great improvements in low-speed torque, maximum output, fuel consumption, and emission reduction. These improvements have been accomplished through variable control of the nozzle vane position, and an optimal velocity of the exhaust gas inflow to the turbine at all times in response to the engine condition.
| *1 | Turbine | *2 | Nozzle Vane |
| *3 | Unison Ring | *4 | Nozzle Ring |
| *5 | Linkage | *6 | Turbocharger Variable Nozzle Motor |
| *7 | Nozzle Vane Position Sensor | - | - |
The exhaust gas from the exhaust manifold goes through the nozzle vane inside the turbocharger housing, and flows to the exhaust pipe through the turbine. The speed of the turbine (supercharging pressure) differs depending on the flow velocity of the exhaust gas going through the turbine and the flow velocity of the exhaust gas is controlled by the opening. When idling, the exhaust gas is less and the nozzle vane is fully closed, but as there is a slight clearance between the vanes, the exhaust gas flows through this clearance to the exhaust pipe. As this type of turbocharger has the nozzle vane operating in these ways, there is no bypass.
OPERATION
Turbo Charger (At Engine Low Speed Range)
When the engine is running in a low speed range, the turbocharger variable nozzle motor presses down the linkage by a signal from the ECM.
This results in increasing the velocity of the exhaust gas flowing to the turbine, as well as the speed of the turbine. As a result, torque is improved when the engine is running at low speeds.
Turbo Charger (At Engine Medium-to-High Speed Range)
When the engine is running in a medium-to-high speed range, the nozzle vanes are opened and the discharging pressure is maintained at a certain level.