L28/32 intake valve seat introduces intake valve characteristics

The intake valve is composed of a valve body, a rotary check valve, a butterfly valve and a control cylinder. The rotary check valve comes with a counterweight and a fluorine rubber sealing ring. When the compressor is turned on, the main body of the compressor sucks in air. Due to the pressure difference, the check valve opens quickly; when the stop, the pressure difference is lost, and it is controlled by the counterweight to check The valve can be closed tightly in time to ensure that there is no stoppage of oil. The opening and closing of the butterfly valve is controlled by the control cylinder. According to the extension of the piston of the control cylinder, the butterfly valve opens or closes to adjust the compressor air intake.

Severe wear and improvement of intake valve and valve seat

Introduction to the characteristics of wear

In a supercharged four-stroke diesel engine, with the increase in supercharging, the average effective pressure is getting higher and higher, and the wear of the intake valve and valve seat is getting worse. Therefore, attention has gradually been paid to the wear of intake valves and valve seats at home and abroad.

It is preliminarily believed that the main cause of wear is friction-related sliding between the valve and the valve seat. This slippage is caused by the flexural deformation of the valve and cylinder head. Under the action of the burst pressure, the pressure of the air valve on the valve seat is very high. It is conceivable that under high pressure, even small sliding, dry friction will cause wear. Similarly, the cylinder head and air valve are deformed. Why is the wear of the exhaust valve and valve seat much lighter than the intake valve? This is because there is a very thin non-metallic layer on the working surface of the exhaust valve and the valve seat. These things are composed of engine oil, ash and smoke particles remaining in the exhaust gas. It prevents metal contact between the air valve and the working surface of the valve seat, so that the friction movement does not cause damage. However, on the intake valve surface, the blowing of the charge air prevents oil from sucking in the valve guide on the one hand, and the other On the one hand, the residual oil and ash on the intake valve surface and the seat surface are blown clean to cause dry friction and damage.