Mini_DV6 charge-air cooling and throttle valve
Overview of components and functions
The charge-air cooling and also the choke action of the fresh air take place in a shared component that is only interchangeable as a complete part. Both throttle valves - for choking the air and changing over the fresh air path - are fitted in a shared housing. The installation location (viewed in the direction of travel of the vehicle) is at the front right in the engine compartment on the top of the engine. This component enables the following functions:
- Choke action for the fresh-air supply by changing the angle of instance of the throttle valve. The adjustment range is 0 % (throttle valve fully opened) to 100 % (throttle valve completely closed). The target position for the throttle valve is calculated using, among other things, the function software for exhaust gas recirculation.
- Charge-air cooler bypass for cooling the air that is taken on changing over the throttle valve to charge-air cooling. If the throttle valve is switched over, the direct path of the fresh air is blocked by the component. The fresh air is then forced to take the longer air path through the charge-air cooling. As a consequence, the fresh air that is taken in reaches a lower temperature - the combustion in the cylinder is influenced by the changed filling in the cylinder. The main reason for the existence of charge-air cooling is the more complete combustion of the particles. As an additional consequence, the particle filter regeneration is more complete - the particle filter becomes less clogged.
At the side of the overall housing directed away from the engine, there are also the sensors for sensing charge-air pressure and charge-air temperature, see the following illustration:
- 1.) Charge-air cooler bypass throttle valve (selector switch) / charge-air cooler actuator
- 2.) Throttle valve (to choke the fresh air)
- 3.) Charge (air) pressure sensor
- 4.) Charge-air temperature sensor
(See also close-up in the following illustration ...):
