Overflow cut-off valve

Abstract

The invention discloses an overflow cut-off valve. Under the condition that a fuel tank is positioned at normal air pressure, gas inside the fuel tank exchanges with external gas through a gas outlet hole; under the condition that greater negative air pressure exists inside the fuel tank, the external gas bursts through a rubber assembly to enable each gas inlet channel to be conducted with a pressure-maintaining plastic part inner cavity; the external gas enters the fuel tank through the gas inlet channels. According to the overflow cut-off valve disclosed by the invention, gas outlet channels and the gas inlet channels are separated without mutual influence; the sizes of the gas outlet channels and the gas inlet channels can be respectively designed, so that the gas inlet channels and the gas outlet channels can be suitable for fuel tanks of vehicles with different powers and different sizes. The fuel tanks of the vehicles with the different sizes have little influence on a gas outlet hole in an annular convex rib because the fueling speed of the fuel tank cannot change due to the change of the size of the fuel tank. The gas inlet channels and the rubber assembly commonly influence the gas inlet speed at negative pressure, so that the air inlet speed can be slightly adjusted according to the gas inlet channels and the rubber assembly to meet the requirements on the fuel tanks with the different sizes.

Description

technical field [0001] The invention relates to a valve body, in particular to an overflow cut-off valve. Background technique [0002] An overflow cut-off valve is usually installed on the vehicle fuel tank, which has the following functions: 1) When the vehicle fuel tank is filled with oil, the vehicle fuel tank and the atmosphere have a certain passage through the overflow cut-off valve; and when the vehicle fuel tank is filled with fuel, The spill shut-off valve automatically closes to prevent fuel from spilling out of the spill shut-off valve. 2) The last important thing is that when the position of the fuel tank changes suddenly (such as the vehicle overturns), the overflow cut-off valve will prevent the fuel from flowing out, such as the patent No. 201210229757.9 published on October 17, 2012. Shut-off valve", including pressure-holding plastic parts and pressure-holding thin rubber, [0003] The periphery of the pressure-holding rubber is pressed between the annul...

AI Technical Summary

Problems solved by technology

[0004] The overflow cut-off valve of this structure has the following problems: the inlet channel of the overflow valve under normal air pressure is the same channel as the outlet channel when the pressure is relatively large, and this channel is the gap between the pressure-holding thin rubber and other components. gap

The small gap when the air is out and the limited deformation of the rubber due to the pressure jointly determine that the intake passage of the relief valve is relatively small when the negative air pressure is relatively large, and the valve is only suitable for small fuel tanks

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