Performance testing of automobiles
1. Engine cylinder tightness inspection
There are seven factors that affect the tightness of the cylinder, mainly including cylinder wear, piston ring damage, piston wear, valve seat damage, valve guide wear, cylinder gasket damage, valve clearance and other issues.
What are the commonly used diagnostic methods? It mainly includes measurement of cylinder pressure, crankcase blow-by gas, cylinder leakage and leakage rate, intake pipe vacuum, and vibration measurement of abnormal noise caused by excessive wear of cylinder piston group. The wear metal in the crankcase is the particle content. measurement.
For the measurement of cylinder compression pressure, it is mainly the pressure at the end of compression of a four-stroke engine. Due to the pressure of the cylinder, the viscosity of the oil and the coordination of the cylinder-piston group, whether the adjustment of the valve train is correct, the sealing performance of the cylinder gasket and other factors, when measuring the pressure of the engine cylinder, the cylinder-piston group can be diagnosed. If the sealing performance of the piston ring, valve and cylinder gasket is good, the clearance of the valve must be appropriate.
2. the muffler firmness test
The muffler is composed of an outer cylinder and an inner honeycomb part, and the two parts are combined by a mechanical wrapping process due to special environments such as high temperature and vibration. We know that the quality of this process depends on the precision of the design. If the combination is not firm, it will loosen or fall off due to high temperature, vibration and other factors in the use of the car. But let us rest assured that the relevant quality first departments have put forward quite strict requirements on this technical aspect.
For the actual testing method, the testing tools in the industry all use the universal material testing machine and the compression plate clamp to subject the two components of the muffler to the relevant shearing force up and down. The repetition error of the measured results should be less than 5%.
3. Interior inspection
The interior includes seat structure materials, interior box decoration materials and adhesives for bonding. Mainly test its safety: 1. Gas harmfulness 2. Flame retardancy.