Function of automobile intake pipe

The intake manifold is a component of the engine, which is located between the throttle valve and the intake valve. It is called manifold because when air enters the manifold through the throttle valve, the manifold buffer system will branch the air flow channel into the number corresponding to the number of engine cylinders. For example, a four-cylinder engine has four cylinders and a five-cylinder engine has five cylinders, and air will be introduced into each cylinder separately. For naturally aspirated engines, the intake pipe is located behind the throttle. When the throttle opening of the engine is small, enough air can not be sucked into the cylinder, which will lead to a high vacuum degree of the manifold. When the engine throttle opening is large, the vacuum in the intake manifold will become smaller. Therefore, installing a pressure gauge on the intake manifold can provide the signal of engine load for the electronic control unit (ECU), so as to determine the appropriate fuel injection quantity. Besides the pressure signal used to judge the engine load, manifold vacuum has other uses. Braking also needs the vacuum assistance of the engine, so when the engine is started, the brake pedal will become lighter due to the vacuum assistance. Some forms of constant speed control mechanisms also utilize manifold vacuum. However, if these vacuum tubes leak or are improperly modified, the engine control will be out of control and the braking effect will be affected. Therefore, readers are advised not to improperly modify the vacuum tube to maintain driving safety.