Exhaust manifold is one of the components of automobile engine, and its performance is required to be air tight, because if there is air leakage in the exhaust manifold

Then it will affect the engine, such as the power performance, emission performance and noise of the whole engine; So the exhaust manifold needs to be full

The sealing conditions of high temperature and high pressure are satisfied.

The progress of the times and the development of detection technology, for the traditional engine exhaust manifold air tightness detection---Both immersion and smear methods have been applied

I've been eliminated. In order to improve the detection efficiency and accuracy, hiris automation technology company has developed a common technology for this standard气密性

检测仪The working principle of differential pressure method for air tightness detection is used to meet the demand of intelligent detection for air tightness of parts in mass production line.

thatAir tightness test by differential pressure methodWhat's your job like? In fact, the gas flow formula is used to calculate by measuring the pressure change in the container

There are four processes in the detection of leakage

（1）Inflation process: set the system pressure to the test pressure, and then open the inflation valve, leak detection valve, standard container and workpiece to be tested

When the force is equal to the test pressure of compressed air, due to the influence of gas flow, the internal pressure and temperature of the system will fluctuate, so it must be continuously inflated

Until the standard container and the tested workpiece are fully inflated.

（2）Balance process: close the charging valve and leak detection valve, cut off the passage between the gas source and the standard container and the workpiece to be measured

The action will cause the pulsation of the gas pressure in the container, resulting in the instability of the differential pressure between the standard container and the measured workpiece, showing irregular changes,

It must be delayed for a period of time until the differential pressure value is stable before measuring the differential pressure change.

（3）Detection process: detect the output of differential pressure sensor. The pressure drop caused by leakage is approximately proportional to the time near the test pressure，

Therefore, the change value of differential pressure can be measured in a certain period of time.

（four）Exhaust process: after the change value of differential pressure is measured, the residual gas in the standard container and the measured workpiece is discharged to the atmosphere through the gas valve, and the exhaust is finished

It's a testing process.