Patent ID: 7722132
Filing Date: 2010-05-25
Classification: B60T

Abstract:
1. Internal combustion engine of the Otto type comprising: an induction pipe in conjunction with the engine's cylinders, a brake servo unit, a valve arrangement, and a flow connection for evacuating air from the brake servo unit to the induction pipe for the purpose of building up a vacuum inside the brake servo unit, in conjunction with which a Venturi unit is arranged in the flow connection to assist with the building up of the aforementioned vacuum, the flow connection comprising a bypass line having a lower flow resistance than the Venturi unit, the bypass line extending from two ends of the valve arrangement, the valve arrangement including a valve body which closes the entrance from the valve arrangement to the portion of the bypass line between the valve arrangement and the brake servo unit for the purpose of conducting air through the Venturi unit, and which opens the entrance from the valve arrangement to the portion of the bypass line between the valve arrangement and the brake servo unit for the purpose of conducting air through the bypass line for the purpose of conducting the evacuated air past the Venturi unit in the event of a transient vacuum in the induction pipe, characterized in that the valve body moves to an open position in conjunction with load alternations from a vacuum to a positive pressure in the induction pipe, and the valve body moves to a closed position in conjunction with load alternations from a positive pressure to a vacuum in the induction pipe, the moving of the valve body to a closed position taking place at a speed such that pressure equalization, between the induction pipe and the brake servo unit in the event of a transient vacuum in the induction pipe, has sufficient time to take place before the valve body has reached a closed position.