The intake manifold of variable length

At 6-cylinder engine in the E 300 Diesel model set of variable length intake manifold. With two movable flaps in the intake system can change the oscillation frequency counter and charge air, which has a direct impact on the value of the engine torque. Due to both dampers in such a system produces three different modes of the airflow. The flaps are driven by a pneumatic vacuum chambers. Vacuum is supplied through the solenoid valves to a corresponding camera. Solenoid valves are controlled by the control unit.

When discharge air pistons create a strong vacuum, which when opened causes the intake valve in the air intake system. If suddenly the intake valves are closed, the air "spruzhinivaet" back - in the suction line occurs oscillation. Its frequency depends on the length of the suction pipe, the engine speed and the engine valve timing. If the vibrations are in resonance, a certain effect is achieved by injection. With dampers can create resonance conditions in a wide range of speeds.

1. If the number of revolutions to 2550 ^min -1, both valves are closed, the volume of air in the intake system can vary the section of the valve to control the pressure.

2. From 2550 to 3350 ^min -1 opens the hatch 1 (Fig. 4.74), the vibrations cease to hatch 1.

3. When the number of revolutions of 3350 ^min -1 over open valve 1 and 2, the vibrations reach the intake manifold.

This switch is used only in the full load of the engine. In order to achieve part load fuel consumption and low clean combustion, other combinations of frequencies required air volume and speed. Therefore, the estimated point of time as the electronic control activates the control valve, and the return of the exhaust gases.