Low-discharge two-stroke gasoline engine

Abstract

The invention discloses a low emission two-stroke gasoline engine, comprising a cylinder body, a piston, a cylinder cavity, a first half crankcase and a second half crankcase, and a crank chamber formed by the first half crankcase and the second half crankcase. The two-stroke gasoline engine is characterized in that scavenging air belts which communicates the crank chamber with the cylinder cavity are symmetrically arranged at the cylinder body, the scavenging air belts feature a closed type structure, and the closed type structure is realized by arranging end covers at the two sides of the cylinder body; gas partition walls are arranged at the scavenging air belts, the gas partition walls divide the scavenging air belts into a scavenging air belt 1 and a scavenging air belt 2 and the angle of the scavenging air belts is designed to be alpha; throttling holes are arranged at a cylinder body combination surface of the first half crankcase and the second half crankcase, and the throttling holes turn the gas flow in the lower reach of the scavenging air belts into impingiment flow, thus effectively reducing content of injurious ingredient (HC and NOx), improving initial discharge, effectively lowering fuel consumption rate of the gasoline engine, and improving economic performance.

Description

technical field [0001] The invention relates to the technical field of gasoline engines, in particular to a small general-purpose two-stroke gasoline engine. Background technique [0002] Two-stroke gasoline engines are widely used in many product fields such as agriculture, forestry, gardening, and households due to their remarkable advantages such as compact structure, small size, light weight, and fast operation speed. The gasoline engine is composed of cylinder block, crankshaft connecting rod assembly, moving parts, magneto, carburetor and other parts. An air intake port, an exhaust port and two scavenging ports are set in the trunk part of the cylinder block. These air ports Both are opened or closed by the movement of the piston. A working cycle of a gasoline engine is completed by two strokes of piston movement, and there is no special setting for intake stroke and exhaust stroke. [0003] When the piston rises to close the intake port, exhaust port, and scavenging...

AI Technical Summary

Problems solved by technology

However, the combustible mixture used for scavenging is easy to mix with the combustion exhaust gas, so that this part of the combustible mixture is discharged without being burned. Therefore, compared with the four-stroke gasoline engine, the two-stroke gasoline engine not only has poor fuel economy performance, but also Exhaust gas contains a large number of harmful components, such as HC and CO

Therefore, although the displacement of the two-stroke gasoline engine is not large, the impact on harmful components in air pollutants is significant.

In addition, the existing two-stroke gasoline engines usually cannot meet the increasingly stringent emission regulations formulated by administrative agencies, especially the HC (hydrocarbons) index in the exhaust gas, which exceeds the limit value of the emission regulations by a lot

[0004] At present, the solution is usually to reduce the HC content in the exhaust gas by adding a catalyst. However, the use of a catalyst not only increases additional costs, but also causes the machine to overheat due to the large amount of heat generated during the chemical reaction of the catalyst, thus reducing the original HC content in the exhaust gas. Emission is a technical problem that those skilled in the art have been trying to overcome but have not yet overcome

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