Integrated toppling-preventive fuel tank cap and carbon canister combination of small gasoline engine

Abstract

The invention provides a toppling-preventive fuel tank cap and carbon canister combination of a small gasoline engine. The toppling-preventive fuel tank cap and carbon canister combination comprises a fuel tank cap outer cover, a clamp ring with lugs, a compression spring and a fuel tank cap sealing pad; the carbon canister loaded with activated carbon is positioned in space formed by a locking framework and the fuel tank cap outer cover in an encircled manner; the carbon canister is hermetically connected with the locking framework; a guide sleeve is connected to the lower portion of the carbon canister, and a lower shell cap is connected to the lower end of the guide sleeve; a valve capable of sliding up and down is arranged in the guide sleeve, a valve spool which is in seal fit with a valve port is arranged at the upper end of the valve, and the valve port is formed in the wall of the carbon canister; a ball is arranged on the lower portion of the valve; the lower portion of a ball seat is connected with the lower shell cap, and the ball is positioned in a conical concave portion of the ball seat; the conical concave portion is communicated with an air inlet formed in the lower shell cap; air outlets are formed in the upper portion of the carbon canister and are communicated with the outside of a fuel tank via air vents formed in the fuel tank cap outer cover or the locking framework; when the toppling-preventive fuel tank cap and carbon canister combination is tilted, the ball in the conical concave portion pushes the valve to move, so that the valve port can be sealed by the valve spool. The toppling-preventive fuel tank cap and carbon canister combination has the advantages that functions of a fuel stop valve, functions of the activated carbon canister and functions of a fuel tank cap are integrated in the toppling-preventive fuel tank cap and carbon canister combination, and the toppling-preventive fuel tank cap and carbon canister combination is simple in structure.

Description

technical field [0001] The invention relates to a fuel tank cover for a small gasoline engine, in particular to an anti-dumping fuel tank cover carbon tank integrating a fuel tank cover, an active carbon tank and a fuel cut-off valve. Background technique [0002] A small gasoline engine is an engine with gasoline as fuel and a power of no more than 19KW. It is often used as a power source for motorcycles, generators, water pumps, lawn mowers and cutting machines. With the wide application of general-purpose small gasoline engines, gasoline volatiles discharged from the vent hole of the fuel tank cap become one of the main sources of air pollution. With global warming in today's world, energy conservation and emission reduction have become the consensus of the whole world. The control of fuel volatilization of general-purpose small gasoline engines has attracted great attention from various countries, especially European and American countries, which have formulated strict ...

AI Technical Summary

Problems solved by technology

Due to the compact structure of the small gasoline engine, the installation position of the carbon canister and the installation position of the fuel shut-off valve are limited

In particular, the best position is to install the fuel shut-off valve at the highest position of the fuel tank, but installing it at the highest position will affect the overall structure of the fuel tank and affect the opening and closing of the fuel tank cap. At present, most manufacturers install the fuel shut-off valve under the fuel tank. The disadvantage of this installation is that the pipeline connecting the fuel tank vent hole to the fuel cut-off valve will inevitably be full of oil when it is not working normally. When it returns to normal work, the oil will directly enter the carbon tank and erode the working ability of the carbon powder. , leading to excessive fuel evaporation emissions; another point is that the desorption of the above carbon canister mainly depends on the suction of the engine negative pressure to desorb the fuel vapor in the canister, which will enrich the gasoline concentration of the engine intake air, and eventually increase deterioration of exhaust emissions

Of course, if the evaporative emission is controlled by modifying the fuel tank, the fuel tank cover and increasing the oil pipe line, it will lead to more accessories, poor reliability, cumbersome installation and increased cost

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