Scavenging boost structure of two-stroke engine

Abstract

The invention provides a scavenging boost structure of a two-stroke engine. The scavenging boost structure comprises a cylinder body assembly and a crankcase assembly. According to the structure, a crankcase scavenging flow limiting hole is designed in a crankcase scavenging channel, a cylinder body scavenging flow limiting hole is designed in a cylinder body scavenging channel, and the effectivearea of the crankcase scavenging flow limiting hole is larger than that of the cylinder body scavenging flow limiting hole. When the engine works normally, mixed gas in the crankcase enters the cylinder body scavenging channel after being boosted by the crankcase scavenging flow limiting hole and then boosted again under the action of the cylinder body scavenging flow limiting hole, the two structures interact, the gas flow speed can be greatly increased, the scavenging efficiency in gas cylinders can be enhanced, the atomization effect on fuel can be promoted substantially, and the combustionefficiency can be improved, so that discharge of THC and NOx in tail gas is greatly reduced; and scavenging flow limiting holes, cylinder bodies and a crankcase body are set as an integrated structure, the scavenging flow limiting holes can be implemented by mold structures, processing procedures are not added, and the manufacturability and practicability are better.

Description

technical field [0001] The invention relates to the technical field of engines, in particular to a scavenging supercharging structure of a two-stroke engine. Background technique [0002] At present, the structure of low-emission two-stroke gasoline engines commonly seen in the market is divided into two types, one is the after-treatment structure, which adds a certain amount of catalyst in the muffler to make the exhaust gas undergo secondary combustion in the muffler to meet the requirements of reducing emissions. Due to cost constraints and safety temperature constraints on the side of the muffler, the catalyst content is often low, resulting in a high THC+NOx value, which is close to the emission limit; Influenced by factors such as gasoline engine power and mixed gas combustion, the original emission data of the traditional layered scavenging structure is usually difficult to meet the requirements of emission regulations. [0003] A cylinder block of a low-emission two...

AI Technical Summary

Problems solved by technology

Compared with the fully open infinite flow hole structure, this kind of single-layer restricting hole structure can increase a certain airflow velocity of the mixed gas, and also promote the atomization effect of part of the fuel, improve the combustion efficiency, and can reduce the exhaust gas to a certain extent. harmful components in exhaust gas, but the effect of reducing harmful components in exhaust gas is limited; on the other hand, considering the structural manufacturability and product cost, the throttle hole is set on the side cover, limited by the mold structure, the throttle hole cannot Mold forming can only be realized by machining, which will increase the processing cost

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