The working principle of automobile fuel tank cover mainly involves sealing, pressure adjustment and protecting the inside of fuel tank from external pollution. The fuel tank cover is designed to ensure the normal operation of the fuel system, and at the same time, to prevent gasoline volatilization and external impurities from entering. The following is a detailed explanation of the working principle of the fuel tank cover:

“Sealing design: The oil tank cover is usually composed of a metal shell and a gasket, and the sealing is realized through the close contact between the metal shell and the gasket. When the oil tank cover is closed, the metal shell is in close contact with the gasket, and the gasket compresses the oil tank mouth, thus achieving the purpose of sealing. This design effectively prevents the gasoline in the fuel tank from volatilizing, at the same time prevents external impurities from entering the fuel tank and keeps the interior of the fuel tank clean. one Pressure adjustment: The fuel tank cover of an automobile is not completely sealed, but plays a role in balancing the internal pressure of the fuel tank. The fuel tank cover is an air pressure regulating valve. When the pressure inside the fuel tank rises, the pressure inside the fuel tank will be higher than the external atmospheric pressure and the elastic force of the spring inside the fuel tank. At this time, the fuel tank cover will open and release some gases in the atmosphere. If the fuel tank cover is sealed, the internal pressure of the fuel tank will increase, which will cause the fuel nozzle to spray more fuel, thus causing the mixture to be too rich and causing the car to stall. Therefore, the function of the fuel tank cover is to control the pressure inside the fuel tank and prevent excessive pressure from adversely affecting the performance of the vehicle. ‌2 Special design: the fuel tank cover of some cars is designed as a one-way valve, using the principle of atmospheric negative pressure in physics. When the negative pressure of the fuel tank reaches a certain value, the valve on the cover will be automatically sucked open, and the outside air can be directly replenished, thus avoiding the problem that the vacuum degree of the automobile fuel tank is too high. In this design, the tank cover is opened before refueling to solve part of the vacuum degree, and then refueling is carried out. three Filtration and protection: the enclosed fuel tank is filled with inert gas at a certain pressure to reduce the content of air, moisture and impurities. The oil tank is equipped with two screens to filter the oil flow, and is equipped with an oil level gauge and an acousto-optic signal to monitor the oil quantity. This design ensures the tightness and filtering effect of the fuel tank, and at the same time monitors the oil level and discharges waste gas.”