WO2022236478A1

WO2022236478A1 - Stratified scavenging two-stroke engine

Info

Publication number: WO2022236478A1
Application number: PCT/CN2021/092404
Authority: WO
Inventors: 胡全宇
Original assignee: 永康市茂金园林机械有限公司
Priority date: 2021-05-08
Filing date: 2021-05-08
Publication date: 2022-11-17

Abstract

A stratified scavenging two-stroke engine, comprising an air filter (3), a carburettor (4), a silencer (17), a gas intake pipe (10), a cylinder (2), a piston (11), a crankshaft (12) and a crankcase (13). The piston (11) is arranged in the cylinder (2), and the piston (11) and a cylinder wall of the cylinder (2) form a combustion chamber (18). The crankshaft (12) and the crankcase (13) are arranged at lower edges of the cylinder (2) and the piston (11). The gas intake pipe (10) communicates with gas intake channels (8, 9) of the cylinder (2). The silencer (17) is connected to an exhaust channel (16) of the cylinder (2). The air filter (3) is connected to the end of the gas intake pipe (10) away from the cylinder (2). The cylinder (2) is provided with independent cylinder air storage chambers (22, 30) and cylinder mixed gas storage chambers (38, 39). The cylinder air storage chambers (22, 30) and the cylinder mixed gas storage chambers (38, 39) are configured to be completely separate and independent. The piston (11) is provided with a fully closed air channel. In actual use, the loss of mixed gas along with exhaust gas into an exhaust system can be reduced; moreover, the scavenging quality, the scavenging efficiency and the scavenging utilisation rate are improved, and the content of HC, CO and other compounds in the exhaust gas is reduced.

Description

A stratified scavenging two-stroke engine

technical field

The invention relates to the field of engines, in particular to a stratified scavenging two-stroke engine.

Background technique

At present, the cylinders of stratified scavenging two-stroke engines all adopt the method of pre-storing a part of air in the left and right scavenging passages of the cylinder. After the piston reaches the top dead center, it goes down. The scavenging ports on both sides of the cylinder are also gradually opened, and the air stored in the scavenging passage first enters the combustion chamber to scavenge first, reducing the uncombusted mixed gas that is discarded and discharged, thereby reducing the discharge of harmful gases such as HC and CO in the exhaust gas. For example ZL201610350517.2, the semi-closed inner channel provided by the piston pre-stores air. When the piston moves upward in the cylinder, the air enters the semi-closed channel of the piston from the intake channel, and then enters the scavenging channel, and then the mixed gas is released from the mixed gas. The channel enters the scavenging channel. When scavenging, the air will be cleaned first, and then the mixed gas will be cleaned. Gas efficiency, reducing the emission of harmful gases such as HC and CO in the exhaust gas.

However, the test shows that when the machine is running at high speed, only a small amount of pre-stored air in the semi-closed inner channel enters the scavenging channel for first scavenging, and the exhaust gas in the combustion chamber is not completely cleaned, and the mixed gas in the latter stage continues to clean the exhaust gas. Part of the mixed gas will be lost with the exhaust gas; and because the semi-closed channels on both sides of the piston are connected, the pre-stored air and mixed gas in the scavenging channel are communicated through the semi-closed channel of the piston, resulting in intermixing and mixing of the gases , when scavenging, not only air, but also unburned mixed gas participate in the exhaust gas discharge; and the asymmetry of the scavenging channel causes the airflow to be unbalanced, forming a vortex, and the unburned mixed gas will be discharged with the exhaust gas; as a result, the HC in the exhaust gas The purification of harmful compounds such as , CO, etc. is not very obvious, which is not conducive to environmental protection.

Contents of the invention

In view of the above-mentioned defects of the prior art, the technical problem to be solved by the present invention is that the existing stratified scavenging two-stroke engine cannot completely isolate the air and the mixture due to its structural design, and cannot avoid During the process, the air and the mixed gas are mixed with each other, resulting in harmful compounds such as HC and CO in the unburned mixed gas being discharged with the tail gas, causing environmental pollution. The invention provides a layered scavenging two-stroke engine, which has mutually independent air intake passages, mixed gas intake passages, mutually independent air storage chambers, mixed gas storage chambers, and mutually independent fully closed passages, In this way, the air and the mixed gas are completely isolated before entering the combustion chamber of the cylinder, avoiding the intermixing and mixing between the air and the mixed gas, and effectively improving the efficiency of stratified scavenging during scavenging.

To achieve the above object, the invention provides a kind of stratified scavenging two-stroke engine, comprises air filter, carburetor, muffler, intake pipe, cylinder, piston, crankshaft and crankcase, and piston is arranged in cylinder, and The piston and the cylinder wall of the cylinder form a combustion chamber; the crankshaft and the crankcase are arranged on the lower edge of the cylinder and the piston, and the crankshaft is connected to the piston through the crankshaft connecting rod; the intake pipe communicates with the intake passage of the cylinder, and the muffler communicates with the cylinder The exhaust channel is connected, and the air filter is connected to the end of the intake pipe away from the cylinder;

Wherein, the cylinder is provided with an independent cylinder air storage chamber and a cylinder mixed gas storage chamber, which are completely separated and independent; the piston is provided with a fully closed air channel.

Further, the cylinder includes an air storage chamber and a mixed gas storage chamber, the air storage chamber is arranged above the mixed gas storage chamber, and the air storage chamber communicates with the inside of the cylinder through the air scavenging port;

The mixed gas storage chamber communicates with the inside of the cylinder through the mixed gas scavenging port, and the lower edge of the mixed gas storage chamber communicates with the mixed gas scavenging channel.

Further, the air storage chamber includes at least two, and the air storage chamber is arranged on the side of the cylinder, and arranged symmetrically;

The mixed gas storage chamber includes at least two, and the mixed gas storage chamber is arranged on the side of the cylinder, and is balanced and symmetrically arranged.

Further, the outer edge of the piston is provided with a fully closed air channel and a piston air storage chamber, the piston air storage room is located on the upper part of the fully closed air channel; the fully closed air channel is located at the intake side of the piston skirt.

Further, the fully-closed air passage is set to be connected to the tunnel mouth on the other side with the shortest irregular passage from the tunnel mouth on one side; Use the shortest irregular channel to connect to the tunnel entrance on the other side.

Further, there are at least two piston air storage chambers and fully enclosed air passages, which are arranged in a balanced and symmetrical manner.

Further, the number of piston air storage chambers and fully-closed air passages is the same as the number of cylinder air storage chambers and mixed gas storage chambers, the piston air storage chambers are arranged on the same side of the intake passage, and the piston air storage chambers are connected to the same side of the intake passage. The air storage chamber of the cylinder is in the angle relationship between the vertical bisector. .

Further, it also includes a scavenging air cover. One side of the scavenging air cover has a smooth arc surface and a layered rib structure, and cooperates with the cylinder block to form a complete cylinder air storage room and a cylinder mixed gas storage room.

Further, the intake pipe includes an upper layer air channel and a lower layer mixed gas channel, the middle of the upper layer air channel is provided with a multi-layer dividing plate, and the middle of the lower layer mixed gas channel is provided with a multi-layer dividing plate.

Further, the intake channel of the cylinder includes a cylinder air channel and a cylinder mixed gas channel, and the cylinder air channel is arranged above the cylinder mixed gas channel; the upper air channel of the intake pipe communicates with the cylinder air channel, and the lower layer of the air intake pipe communicates with the cylinder air channel. Cylinder mixture passage communicates.

technical effect

A stratified scavenging two-stroke engine of the present invention has an independent air storage chamber and an air intake channel, including an independent cylinder air intake port, so as to ensure that the air and the mixed gas are completely separated before the air enters the cylinder Come, to avoid the incompletely combusted mixed gas connected to the exhaust gas to be discharged together during scavenging, resulting in short-circuit loss, resulting in high HC emissions. In a layered scavenging two-stroke engine of the present invention, during the upward movement of the piston, the piston fully seals the air channel and the air storage room of the piston, which increases the storage capacity of pure air in the cylinder air storage room; when scavenging, the two cylinders There is a large amount of pure air in the air storage room on the side to clean the exhaust gas first, and then the mixed gas is cleaned, which minimizes the loss of the mixed gas to the exhaust system along with the waste, and greatly improves the quality, efficiency and efficiency of the scavenging air. The gas utilization rate is greatly reduced, and the content of HC, CO and other compounds in the exhaust gas is greatly reduced.

The idea, specific structure and technical effects of the present invention will be further described below in conjunction with the accompanying drawings, so as to fully understand the purpose, features and effects of the present invention.

Description of drawings

Fig. 1 is the schematic diagram of a kind of stratified scavenging two-stroke engine of a preferred embodiment of the present invention;

Fig. 2 is a sectional view of a cylinder and a piston of a stratified scavenging two-stroke engine of a preferred embodiment of the present invention;

Fig. 3 is a sectional view of a cylinder of a stratified scavenging two-stroke engine of a preferred embodiment of the present invention;

Fig. 4 is a schematic cross-sectional view of a piston of a stratified scavenging two-stroke engine of a preferred embodiment of the present invention;

Fig. 5 is the left view of a kind of stratified scavenging two-stroke engine of a preferred embodiment of the present invention;

Fig. 6 is the right side view of a kind of stratified scavenging two-stroke engine of a preferred embodiment of the present invention;

Fig. 7 is another schematic cross-sectional view of a piston of a stratified scavenging two-stroke engine according to a preferred embodiment of the present invention;

Fig. 8 is another schematic cross-sectional view of a piston of a stratified scavenging two-stroke engine of a preferred embodiment of the present invention;

Fig. 9 is a schematic diagram of a piston of a stratified scavenging two-stroke engine of a preferred embodiment of the present invention;

Fig. 10 is a schematic perspective view of a piston of a stratified scavenging two-stroke engine according to a preferred embodiment of the present invention;

Fig. 11 is a schematic diagram of the crankshaft rotation direction of a stratified scavenging two-stroke engine according to a preferred embodiment of the present invention;

Fig. 12 is a comparison chart of emission values of a stratified scavenging two-stroke engine of a preferred embodiment of the present invention;

Fig. 13 is a cross-sectional view of a cylinder and a piston of a stratified scavenging two-stroke engine according to a preferred embodiment of the present invention.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

As shown in Figure 1, the embodiment of the present invention provides a kind of stratified scavenging two-stroke engine 1, comprises air filter 3, carburetor 4, muffler 17, intake pipe 10, cylinder 2, piston 11, crankshaft 12 And crankcase 13, piston 11 is arranged in cylinder 2, and the cylinder wall of piston 11 and cylinder 2 forms a combustion chamber 18; Crankshaft 12 and crankcase 13 are arranged on the lower edge of cylinder 2 and piston 11, and crankshaft 12 passes The crankshaft connecting rod 14 is connected with the piston 11; the intake pipe 10 is connected with the

intake passages

8 and 9 of the cylinder 2, the muffler 17 is connected with the exhaust passage 16 of the cylinder 2, and the air filter 3 is connected with the end of the intake pipe 10 away from the cylinder ;

Wherein, as shown in Fig. 5 and Fig. 6, cylinder 2 is provided with independent cylinder

air storage chamber

22,30 and cylinder mixed

gas storage chamber

38,39, cylinder

air storage chamber

22,30 and cylinder mixed

gas storage chamber

38,39 It is set to be completely separated and independent; as shown in FIG. 10 , the piston is provided with fully closed

air passages

24 and 32 . Piston molds with fully closed air passages require high mold opening technology, and blank molding is more complicated. When the piston with fully closed air channel is heated at high temperature, the shape of the outer circle is heated regularly and the heat dissipation is balanced; while the piston with open channel is concave on both sides, and the outer circle is easy to deform when heated at high temperature, which is more likely to cause the mixed gas and air to mix.

As shown in Figures 5 and 6, the cylinder 2 includes

air storage chambers

22, 30 and mixed

gas storage chambers

38, 39, the

air storage chambers

22, 30 are arranged above the mixed

gas storage chambers

38, 39, the

air storage chambers

22, 30 communicates with the inside of the cylinder through the air scavenging port; the mixed

gas storage chamber

38, 39 communicates with the inside of the cylinder through the mixed gas scavenging port, and the lower edge of the mixed

gas storage chamber

38, 39 communicates with the mixed gas scavenging channel. The

air storage chambers

22 and 30 include at least two, and the air storage chambers are arranged on the side of the cylinder, and are arranged in a balanced and symmetrical manner; the mixed gas storage chambers include at least two, and the mixed gas storage chambers are arranged on the sides of the cylinder, and are arranged in a balanced and symmetrical manner . In this embodiment, there are two air storage chambers arranged symmetrically on the side of the cylinder and symmetrically with the axis of the cylinder; there are two mixed gas storage chambers arranged symmetrically on the side of the cylinder and symmetrically with the axis of the cylinder; and, The air storage chamber is arranged above the mixture storage chamber. The total volume range of the air storage chambers arranged on both sides of the cylinder: 0.8 to 3.5cc.

As shown in Figure 10, the outer edge of piston 11 is provided with fully closed

air channel

24,32 and piston

air storage chamber

23,37, and piston

air storage room

23,37 is positioned at the top of fully closed

air channel

24,32; The closed

air channels

24, 32 are located on the intake side of the piston 11 skirt. The fully closed

air passages

24, 32 are arranged to be connected to the other side of the tunnel mouth by the shortest irregular passage from the tunnel mouth on one side in the piston air intake direction. There are at least two piston air storage chambers and fully enclosed air passages, which are balanced and symmetrically arranged. In this embodiment, there are two piston air storage chambers and fully closed air passages, which are arranged symmetrically with the axial direction of the piston.

Among them, the number of the piston air storage chamber and the fully closed air passage is the same as that of the cylinder air storage chamber and the mixed gas storage chamber; the piston air storage chamber of the piston is in the same side direction as the intake passage of the cylinder, and the piston The air storage chamber and the cylinder air storage chamber of the cylinder are in an angle close to the vertical bisector, as shown in Figure 12. From the cross-section of the piston and the cylinder, it can be seen that the piston air storage chamber of the piston and the cylinder air of the cylinder The storage chamber is 90°; the piston air storage chamber of the piston and the mixed gas storage chamber of the cylinder form an angle close to the vertical bisector, and the mixed gas storage chamber of the cylinder is in the same side direction as the cylinder air storage chamber, and is arranged on the cylinder air storage chamber chamber below.

As shown in Figure 3, the outside of the cylinder also includes scavenging air covers 27, 28, one side of the scavenging air cover has a smooth arc surface and is formed by a layered rib structure, and cooperates with the cylinder body to form a complete cylinder

air storage chamber

22, 30 and cylinder mixture storage chamber.

As shown in Figure 1, the intake pipe 10 includes an upper air passage 10a and a lower mixed gas passage 10b, a multi-layer splitter is arranged in the middle of the upper air passage 10a, and a multi-layer splitter is arranged in the middle of the lower mixed gas passage 10b. The air intake channel includes an air channel 9 and a mixed gas channel 8, and the air channel 9 is arranged above the mixed gas channel 8; the upper air channel 10a of the intake pipe 10 communicates with the air channel 9, and the lower layer of the air channel 10b of the air intake pipe 10 communicates with the mixed gas channel 8. Air channel 8 communicates.

When the stratified scavenging two-stroke engine of the embodiment of the present invention is running, the pure air enters the upper air channel of the intake pipe through the air filter and the carburetor when the piston moves upward in sequence. The air first enters the piston air storage chamber for pre-storage; the piston continues upward, and the pure air in the air intake pipe is sucked into the fully closed air channel of the piston and stored in the cylinder air storage chamber; the piston continues upward, and the mixed gas enters the lower layer of the intake pipe The channel opens the intake port of the cylinder mixture gas, and the mixture gas communicates with the cylinder mixture gas passage through the crank chamber and is stored in the cylinder mixture gas storage chamber.

Then, the piston goes down, and the upper edge of the piston opens the exhaust port and the air scavenging port in the cylinder in sequence. When the mixed gas scavenging port is opened, the stratified air is cleaned first, and then the mixed gas is cleaned; the opening time of the air scavenging port is shorter than that of the exhaust The port opening time is α later than the crank angle, α=2-12 degrees; the mixed air scavenging port opening time is β later than the air scavenging port opening time, β=0.5-13 degrees.

The specific implementation process of a stratified scavenging two-stroke engine of the present embodiment will be described below in conjunction with Fig. 1-10:

In the corresponding position shown in Figure 1-10, when the piston 11 moves upward, the combustible gas mixture in the cylinder body is compressed, and at the same time, the volume of the crank chamber 15 along the lower edge 25 of the piston becomes larger, forming a negative pressure.

After the piston 11 ascends to the

upper edge

42, 43 of the piston air storage chamber in sequence and combines with the

air inlets

33, 34, and the

air inlet passages

9, 44, the pure air passes through the air filter 3 and the carburetor under the action of atmospheric pressure. The choke valve 5 of 4, the connecting piece 6, the air channel 10a above the throttle valve 7 and the upper floor of the intake pipe 10 enter into the piston

air storage chamber

23,37 for pre-stored.

When the piston 11 continues to move upwards to the

upper edges

40, 41 of the air intake end of the fully closed passageway of the piston and combines with the

air inlets

33, 34, the pure air pre-existing in the piston

air storage chambers

23, 37 will enter with the air. The pure air in the

gas channel

9,44 is sucked into the cylinder

air storage chamber

22,30 through the piston fully

closed air channel

24,32 for compression storage.

When the piston 11 continues to move up in sequence, the lower edge 25 of the piston opens the mixed gas inlet port 35, and after the mixed gas inlet channel 8 is combined, the combustible mixed gas passes through the resistance of the air filter 3 and the carburetor 4 under the action of atmospheric pressure. The gas mixture channel 10b below the damper 5, the connecting piece 6, the throttle valve 7, and the lower layer of the intake pipe 10 is sucked into the crank chamber 15.

When the piston 11 continues to move up to the top dead center in sequence, the spark plug 45 emits electric sparks to ignite the mixed gas compressed into the combustion chamber 18, and the high-temperature and high-pressure gas after combustion forces the piston 11 to go down, closing the mixed gas in turn. Intake port 35,

air intake port

33, 34, here, the combustible mixed gas inhaled into crank chamber 15 is pre-compressed due to the downward movement of piston 11, positive pressure is formed in crank chamber 15, and combustible mixed gas in crank chamber 15 It is compressed into the

cylinder mixture passages

26, 29 and stored in the cylinder

mixture storage chambers

38, 39.

When the piston 11 descends sequentially, the upper edge 19 of the piston opens the exhaust port 36, and part of the exhaust gas flows into the muffler 17 through the exhaust passage 16 and is discharged into the atmosphere, and the piston 11 continues to descend sequentially. The upper edge 19 of the piston opens the

air scavenging ports

21, 31 , at this time, the pure air pre-stored in the cylinder

air storage chambers

22 and 30 in the cylinder 2 first enters the combustion chamber 18 to clean the exhaust gas first, and then the upper edge 19 of the piston opens the mixed gas scavenging port 20, and the cylinder mixed gas storage room in the cylinder 2 38, 39 The pre-stored combustible mixed gas enters the combustion chamber 18 and then scavenges. Since the exclusive cylinder

air storage chambers

22, 30 and the exclusive cylinder mixed

gas storage chambers

38, 39 are symmetrically arranged on both sides of the cylinder 2, they are mutually independent and balanced to avoid The pure air and combustible mixed gas are mixed with each other, which can greatly increase the pure air storage capacity of the cylinder

air storage chambers

22 and 30, and there are symmetrical dedicated

air scavenging ports

21 and 31 and exclusive mixed gas scavenging ports 20 on both sides of the cylinder 2 The structure is arranged in a balanced manner, which greatly improves the good scavenging efficiency and reduces the phenomenon that the incompletely combusted mixed gas is discharged with the exhaust gas, thereby effectively reducing harmful compounds such as HC and CO in the exhaust gas.

As shown in Figures 11 and 12, for an engine with a displacement of less than 50cc, the Euro 5 emission regulations require a HC+NOx ratio emission limit of 50g/kw.h. Stroke engine structure, at the optimal design point, when the opening time of the air scavenging port is α later than the opening time of the exhaust port in the crank angle, α=6.9 degrees; when the opening time of the air scavenging port is 1 The crankshaft angle is higher than β, β=10.3 degrees; when the total volume of the air storage chambers on both sides of the cylinder is: 2.15cc, the optimal emission value HC+NOx: 37~42g/kw.h, lower than the provisions of the Euro V emission law .

The use principle of the existing stratified scavenging two-stroke engine is that air is pre-stored in the scavenging channel, and in the scavenging channel, it is divided from top to bottom: air, mixed gas of air and mixed gas, mixed gas, in When the calculation is perfect, when scavenging, the air in the scavenging channel is swept into the combustion chamber first, and then enters the mixture of air and mixed gas. However, in practical applications, the calculation cannot be very accurate and cannot be achieved. This ideal state. Moreover, due to the large negative pressure at the exhaust port, when the unburned mixture enters the combustion chamber through the scavenging port, due to the large negative pressure at the exhaust port, the unburned mixture will still If it does not reach the bottom of the combustion chamber, it will be discharged out of the exhaust port, causing environmental pollution. And a kind of layered scavenging two-stroke engine of the embodiment of the present invention, when running, the pure air prestored in the air storage chamber is first input into the combustion chamber, and when the upper edge of the piston is opened the mixed gas scavenging port, the load of the exhaust port At this time, the mixed gas enters the combustion chamber, which can effectively prevent the mixed gas from being discharged without fully burning.

Therefore, a kind of stratified scavenging two-stroke engine of the embodiment of the present invention has exclusive pure air storage room and exclusive mixed gas storage room in the cylinder body, isolates pure air and combustible mixed gas intermingled with each other, pure The air is communicated through the air storage chamber of the piston and the fully enclosed air passage of the piston, which increases the pure air storage capacity in the cylinder air storage chamber in the cylinder, and there are exclusive air scavenging ports and exclusive mixed air scavenging ports in the cylinder body. To achieve stratification, a large amount of pure air is cleaned first, and then the mixed gas is cleaned, which greatly improves the scavenging quality, scavenging efficiency, and scavenging utilization rate, and reduces the phenomenon that combustible mixed gas is discharged with the exhaust gas, thereby greatly reducing HC and CO in the exhaust gas. and other harmful compounds.

The preferred specific embodiments of the present invention have been described in detail above. It should be understood that those skilled in the art can make many modifications and changes according to the concept of the present invention without creative effort. Therefore, all technical solutions that can be obtained by those skilled in the art based on the concept of the present invention through logical analysis, reasoning or limited experiments on the basis of the prior art shall be within the scope of protection defined by the claims.

Claims

A stratified scavenging two-stroke engine comprises an air filter, a carburetor, a muffler, an intake pipe, a cylinder, a piston, a crankshaft and a crankcase, the piston is arranged in the cylinder, and the piston and the The cylinder wall of the cylinder forms a combustion chamber; the crankshaft and the crankcase are arranged on the lower edge of the cylinder and the piston, and the crankshaft is connected with the piston through a crankshaft connecting rod; The air pipe is in communication with the intake passage of the cylinder, the muffler is connected with the exhaust passage of the cylinder, and the air filter is connected with the end of the intake pipe away from the cylinder;

It is characterized in that the cylinder is provided with an independent cylinder air storage chamber and a cylinder mixed gas storage chamber, and the cylinder air storage chamber and the cylinder mixed gas storage chamber are set to be independent and completely separated from each other; the piston is provided with a fully closed air channel.
A stratified scavenging two-stroke engine according to claim 1, wherein the cylinder comprises a cylinder air storage chamber and a cylinder mixture storage chamber, and the cylinder air storage chamber is arranged in the cylinder mixture storage chamber. Above the chamber, the cylinder air storage chamber communicates with the interior of the cylinder through the air scavenging port;

The cylinder mixed gas storage chamber communicates with the inside of the cylinder through the mixed gas scavenging port, and the lower edge of the cylinder mixed gas storage chamber communicates with the mixed gas scavenging channel.
A stratified scavenging two-stroke engine according to claim 2, wherein the cylinder air storage chamber comprises at least two, and the cylinder air storage chamber is arranged on the side of the cylinder, and is balanced and symmetrical arrangement;

The cylinder mixture storage chamber includes at least two, and the cylinder mixture storage chamber is arranged on the side of the cylinder, and arranged symmetrically.
A kind of stratified scavenging two-stroke engine as claimed in claim 1, it is characterized in that, the outer edge of described piston is provided with fully closed air channel and piston air storage room, and described piston air storage room is located at the The upper part of the closed air channel; the fully closed air channel is located on the intake side of the piston skirt.
A kind of stratified scavenging two-stroke engine as claimed in claim 4, it is characterized in that, said fully closed air channel is arranged to connect to the other side tunnel mouth with the shortest irregular channel from one side tunnel mouth .
The stratified-scavenging two-stroke engine according to claim 4, wherein the piston air storage chamber and the fully-closed air passage comprise at least two, and are arranged in a balanced and symmetrical manner.
A stratified scavenging two-stroke engine according to claim 6, wherein the number of the piston air storage chamber and the fully closed air passage is the same as the number of the air storage chamber and the number of the cylinder The number of the mixed gas storage chambers is the same; the piston air storage chamber is arranged on the same side of the intake passage, and the piston air storage chamber and the air storage chamber of the cylinder form an angle relationship between a vertical bisector.
A kind of stratified air-scavenging two-stroke engine as claimed in claim 1, is characterized in that, also comprises air-scavenging cover, and one side of described air-scavenging cover is smooth arc-shaped surface and has layered rib structure to form, and cylinder cylinder The body cooperates to form a complete cylinder air storage chamber and a cylinder mixed gas storage chamber.
A kind of stratified scavenging two-stroke engine as claimed in claim 1, it is characterized in that, described intake pipe comprises upper layer air passage and lower layer mixed gas passage, and the middle of described upper layer air passage is provided with multi-layer dividing plate, A multi-layer splitter is arranged in the middle of the mixed gas channel in the lower layer.
A kind of stratified scavenging two-stroke engine as claimed in claim 9, is characterized in that, the intake passage of described cylinder comprises cylinder air passage and cylinder mixed gas passage, and described cylinder air passage is arranged in the cylinder mixed gas passage. Above the passage; the upper layer air passage of the intake pipe communicates with the cylinder air passage, and the lower mixture gas passage of the intake pipe communicates with the cylinder mixture passage.