Causes of excessive absolute pressure of intake manifold

The reason why the intake manifold pressure of Pacific Auto Network engine is high is that the smaller the throttle opening, the greater the suction effect formed by the piston during intake, the greater the suction of the intake manifold and the greater the vacuum degree, that is, the lower the intake manifold pressure (at this time, the suction of the intake manifold is opposite to its suction).

Engine speed, the higher the engine speed, the greater the suction force formed by the piston during intake, the greater the suction force of the intake manifold and the greater the vacuum degree, that is, the smaller the intake manifold pressure;

Sealing performance, including the sealing performance of intake manifold and cylinder, the better the sealing performance, the greater the suction of intake manifold and the greater the vacuum degree, that is, the smaller the pressure of intake manifold.

The pressure sensor is based on piezoresistive effect. The pressure directly acts on the front surface of the ceramic diaphragm, resulting in slight deformation of the diaphragm. Thick film resistor is printed on the back of ceramic diaphragm and connected to form Wheatstone bridge. Due to the piezoresistive effect of the piezoresistive resistor, the bridge generates a highly linear voltage signal proportional to the pressure and excitation voltage. The standard signal is calibrated as 2.0/3.0/3.3mV/V according to different pressure ranges, which can be compared with the strain sensor. (Photo/Text/Photo: Pacific Auto Network Zhang Fengxue)