1、 Engine cylinder sealing test
There are seven factors affecting the sealing performance of the cylinder, mainly including cylinder wear, piston ring damage, piston wear, valve seat damage, valve guide wear, cylinder gasket damage, valve clearance, etc.
What are the common diagnostic methods? It mainly includes the vibration measurement of cylinder pressure, crankcase blowby, cylinder leakage and leakage rate, intake pipe vacuum, abnormal noise caused by cylinder piston group due to excessive wear. The wear metal in crankcase is the measurement of particle content.
For the measurement of cylinder compression pressure, it is mainly the pressure at the end of compression of the four stroke engine. Because of the cylinder pressure and the viscosity of the oil, as well as the compatibility of the cylinder piston group, whether the adjustment of the valve distribution mechanism is correct, the sealing of the cylinder gasket and other factors, when measuring the pressure of the engine cylinder, you can diagnose the sealing of the cylinder piston group. If the sealing of the piston ring, valve and cylinder gasket is good, the valve clearance must be appropriate.
2、 Silencer firmness test
The silencer is composed of an outer cylinder and an inner honeycomb part. The two parts are combined by mechanical buckle wrapping process due to high temperature, vibration and other special environments. We know that the quality of this process depends on the precision of the design. If it is not firmly combined, it will become loose or fall off due to high temperature, vibration and other factors in the use of the car. However, we can rest assured that the first quality department has put forward quite strict requirements on this technology.
For the actual testing method, the testing tools in the industry are all universal material testing machines, using compression disc clamps to subject the two components of the muffler to the upper and lower shear forces. The repetition error of the measured results shall be less than 5%.
3、 Interior inspection
The interior trim includes seat bonding materials, interior box decoration materials and adhesive. It mainly tests its safety: 1. harmful gas; 2. flame retardancy.
