Oil filler cap structure of positive pressure one-way valve

Abstract

The present invention provides an oil filler cap structure of a positive pressure one-way valve, which may reduce an evaporative emission limit value and decrease the false detection frequency of a fuel system of an OBD negative pressure detection scheme with low costs. The oil filler cap structure of the positive pressure one-way valve comprises a valve body and an upper cap. A lower portion of the valve body is provided with a valve element mounting cavity. The valve element is arranged in the valve element mounting cavity. The upper cap is disposed on an upper end face of the valve body. The oil filler cap structure is characterized in that a guide component cavity is formed vertically over the valve element mounting cavity, and an inner sealing element, a lower supporting plate and anupper supporting plate are arranged in the guide component cavity sequentially from bottom to top. The diameter of the guide component cavity is larger than the diameter of the top of the valve element mounting cavity. A lower end face of the inner sealing element seals a top region of the valve element mounting cavity. The lower supporting plate is pressed against an upper end face of the inner sealing element. Linear springs are arranged in vertically cavities of the lower supporting plate and the upper supporting plate, and the mounting cavities corresponding to the linear springs are particularly linear spring guide region cavities.

Description

technical field [0001] The invention relates to the technical field of stress relief for injection molding products, in particular to a fuel filler cap structure for a positive pressure check valve. Background technique [0002] At present, most of the fuel filler caps used in automobile fuel systems are positive pressure / negative pressure two-way valve structures. This is mainly because under certain conditions, the fuel system can balance the internal and external pressures through the fuel filler caps, thereby reducing the pressure on the fuel tank system. Deformation, improve the welding reliability of various valves and improve the service life of the fuel system as a whole. [0003] However, with the release of the draft regulations of the sixth phase of the country "Light-duty Vehicle Pollutant Emission Limits and Measurement Methods", on the one hand, the evaporative emission limits for Type IV tests have been strengthened; on the other hand, on-board diagnostic (OBD...

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Problems solved by technology

[0003] However, with the release of the sixth phase of the country's "Light Vehicle Pollutant Emission Limits and Measurement Methods" draft regulations, on the one hand, the evaporative emission limits for Type IV tests have been strengthened; on the other hand, on-board diagnostic (OBD) systems have been mandated

The traditional positive pressure / negative pressure two-way valve structure, because it is a two-way channel structure design, leads to an increase in the evaporative emission limit, which cannot meet the stricter National VI regulations.

At the same time, there are currently two main OBD detection solutions, namely positive pressure detection and negative pressure detection. The oil filler cap designed with positive pressure / negative pressure two-way valve structure can easily cause OBD detection errors under certain conditions. Alarm frequency, cause trouble

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