Two-stroke gasoline engine cylinder

Abstract

The invention relates to a two-stroke gasoline engine cylinder. The cylinder comprises a cylinder body, a first side cover and a second side cover, wherein after the first side cover is matched with the cylinder body, one pure air storing chamber is formed; after the second side cover is matched with the cylinder body, another pure air storing chamber is formed; the cylinder body is provided witha pure air inlet, a mixer gas inlet, a scavenging port and an exhausting port; the installing flange positions, close to scavenging channels on the two sides, of the cylinder body are provided with aplurality of scavenging flow limiting holes; the structure of the scavenging flow limiting holes can limit the scavenging charge and increase the scavenging speed for mixed gas participating in scavenging, so that the mixed gas fast passes through the scavenging flow limiting holes to fast eject pure air in the pure air storing chambers into a combustion chamber, the charge of fresh gas in tail gas is faster occupied, and due to the fact that the tail gas exhausted out of the exhausting port of the cylinder body contains lots of fresh pure air, the content of THC and CO in the tail gas can begreatly lowered, and the purpose of energy saving and emission reducing is achieved.

Description

technical field [0001] The invention relates to the technical field of gasoline engines, in particular to a cylinder block of a two-stroke gasoline engine. Background technique [0002] For the stratified scavenging two-stroke gasoline engines currently available in the market, the cylinder scavenging passages are usually long and thin passages, some of which are designed to be symmetrical or asymmetrical. For gasoline engines with a displacement greater than 50cc, the emission regulations require The specific emission limit of HC+NOx is 72g / (kW·h). Although the implementation of this structure can meet the requirements of emission regulations without adding a catalyst to the muffler, the specific emission of HC+NOx is often close to the limit; For gasoline engines less than 50cc, the HC+NOx specific emission limit required by emission regulations is 50g / (kW h), affected by factors such as gasoline engine power and mixture gas combustion, it is usually difficult to achieve t...

AI Technical Summary

Problems solved by technology

[0003] In CN201420160669, a cylinder block of a stratified scavenging two-stroke gasoline engine is disclosed, which includes a cylinder body, a scavenging channel cover plate, and a throttle plate, and the throttle plate is placed in the auxiliary scavenging channel, and the throttle plate There are limited through-holes on it, and the invention expresses that the throttle plate structure is only provided in the auxiliary scavenging air passage, and the throttle plate is an independent unit with respect to the cylinder body and the scavenging air passage cover plate. The position is located in the middle and upper part of the auxiliary scavenging air channel, the throttle plate is closer to the scavenging air port, the pure air scavenging path is short, and the pure air cavity in the auxiliary scavenging air channel is small, causing the engine to enter the auxiliary scavenging through limited through holes when it is running at high speed There is less pure air in the air passage. Compared with the traditional stratified scavenging engine, it can reduce the harmful components in the exhaust gas to a certain extent, but the effect on the reduction of harmful components in the exhaust gas is limited; on the other hand, from the structural manufacturability And product cost considerations, the throttle plate described in this invention is an independent component, which needs to be made through a special mold, and the throttle plate needs to be placed in the corresponding position when assembling the cylinder body and the scavenging channel cover plate, and the operation Difficult, as mentioned above, the invention does not have certain economical and practical

[0004] In CN201220103042, a low-emission two-stroke gasoline engine cylinder block is disclosed, which is provided with a throttle hole at the joint surface of the side cover and the cylinder block, the throttle hole is located on the side cover, and the side cover is an integral structure, and the patent CN201420160669 The principle is similar. After the side cover is assembled to the cylinder body, the orifice is also located in the middle and upper part of the scavenging channel. The orifice is closer to the scavenging port, the pure air scavenging path is short, and the pure air cavity in the scavenging channel is smaller. When the engine is running at high speed, the pure air entering the scavenging passage is relatively small. Compared with the traditional stratified scavenging engine, it can reduce the harmful components in the exhaust gas to a certain extent, but the effect on reducing harmful components in the exhaust gas is limited; On the other hand, in terms of structural manufacturability and product cost, the throttle hole is set on the side cover. Due to the limitation of the mold structure, the throttle hole cannot be molded and can only be realized by machining, which will increase the processing cost

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