CN202659337U

CN202659337U - Two-stroke engine

Info

Publication number: CN202659337U
Application number: CN2012201406146U
Authority: CN
Inventors: 杜涛
Original assignee: TIANJIN INTERNAL-COMBUSTION ENGINE INST
Current assignee: TIANJIN INTERNAL-COMBUSTION ENGINE INST
Priority date: 2012-04-06
Filing date: 2012-04-06
Publication date: 2013-01-09
Anticipated expiration: 2022-04-06

Abstract

The utility model discloses a two-stroke engine. The engine comprises a gas path which communicates with a scavenging passage and an exhaust outlet at a predetermined piston position, and the gas path consists of the scavenging passage, the exhaust outlet and at least one grooved channel. The scavenging passage first uses EGR (exhaust gas recirculation) exhaust gas to scavenge waste gas and then uses oil-gas mixture to scavenge waste gas in order to better achieve the purpose of reducing the emission of the two-stroke engine.

Description

A kind of two stroke engine

Technical field

The utility model relates to a kind of two stroke engine, relates in particular to scavenging air belt and carries out scavenging with EGR waste gas first, and then carry out scavenging with fuel-air mixture, better to reach the two stroke engine that reduces the two stroke engine discharging.

Background technique

At present, two-stroke gasoline engine discharges that improved common control device has that catalytic converter, scavenge trunk structural dimension optimization, chamber structure in baffler or the outlet pipe is dimensionally-optimised, firing time, ignition energy optimization, adopt air guide's layered scavenging etc., reaches the purpose of the discharging that as far as possible reduces harmful gas by the escape amount that reduces empty G﹠O vapour mixed gas.

Except the technological means of above-mentioned several control two stroke engine exhaust emissions commonly used, the technological scheme of attempting further to study and realize reducing from the angle of improving engine piston structure exhaust index is arranged also in the art.US Patent No. 6691650B2 and Chinese patent CN1804379A disclose a kind of structure of similar two stroke engine, it mainly is by a passage is set at piston wall, air is sent to the scavenge trunk from the air inlet of air inlet side, make this scavenge trunk when scavenging, realize carrying out scavenging with pure air first, and then carry out scavenging with fuel-air mixture, thereby can effectively reduce the discharging of two stroke engine.

For prior art, the purpose of this utility model also is by a kind of two stroke engine is provided, this motor can realize that scavenging air belt carries out scavenging with EGR waste gas first, and then carries out scavenging with fuel-air mixture, better to reach the purpose that reduces the two stroke engine discharging.

The model utility content

In order to solve the problems of the technologies described above, the utility model discloses a kind of two stroke engine, comprise: cylinder, in described cylinder, there is one by the firing chamber of reciprocating pistons delimit, described piston is by the bent axle of connecting rod drive installation in crankcase, wherein said cylinder is provided with one for the relief opening of waste gas from the firing chamber discharge, described cylinder also is provided with at least one scavenge trunk that enters the firing chamber as air-fuel mixture gas from crankcase, one end opening of described scavenge trunk is to the firing chamber, the other end is communicated with crankcase, it is characterized in that, described motor also comprises one at predetermined piston position connection scavenge trunk and the gas path of relief opening, and described gas path comprises the scavenge trunk, relief opening and at least one recess channels that arranges at the side surface of described piston.

Described scavenge trunk is divided into the first scavenging air belt and the second scavenging air belt by a next door.

Described gas path does not comprise the second scavenging air belt.

Described recess channels is two.

The cross section of described recess channels is arc.

Compared with prior art, the beneficial effect of a kind of two stroke engine of the present utility model is:

By changing the structure of prior art engine piston, carry out scavenging with EGR waste gas first with the realization scavenging air belt, and then carry out scavenging with fuel-air mixture, better to reach the purpose that reduces the two stroke engine discharging.

Description of drawings

Fig. 1 is the structural representation that the utility model two stroke engine piston is positioned at the lower dead center state;

Fig. 2 is the structure sectional view of cylinder shown in Fig. 1;

Fig. 3 is the vertical profile structural representation of the two stroke engine when being positioned at predetermined piston position of piston shown in Fig. 1;

Fig. 4-the 1st, the cross-sectional structural representation of the two stroke engine of position shown in Fig. 3;

Fig. 4-the 2nd, other form of cross-sectional structural representation of the two stroke engine of position shown in Fig. 3;

Fig. 5-the 1st, the schematic representation of piston structure shown in Fig. 1;

Fig. 5-the 2nd, the cross-sectional structural representation of piston shown in Fig. 5-1;

Description of reference numerals: 1. cylinder; 2. firing chamber; 3. piston; 4. recess channels; 6. scavenge trunk; 61. the first scavenging air belt; 62. the second scavenging air belt; 10. suction port; 11. connecting rod; 12. crankcase; 13. relief opening; 14. bent axle; 20. next door.

Embodiment

The flesh and blood of the two stroke engine that the utility model relates to is: how to realize that scavenging air belt carries out scavenging with EGR waste gas first, and then carry out scavenging with fuel-air mixture, reduce the two stroke engine discharging better to reach.Below in conjunction with the drawings and specific embodiments the utility model is described in further detail.

As shown in figures 1 and 3, the utility model two stroke engine comprises cylinder 1, firing chamber 2, piston 3 and crankcase 12, described firing chamber 2 is defined by reciprocating piston 3, described piston 3 is by on the bent axle 14 of connecting rod 11 drive installations in crankcase 12, described cylinder 1 is provided with one for the relief opening 13 of waste gas from the firing chamber discharge, be provided with a suction port 10 of fuel oil and air fuel-air mixture being introduced crankcase 12 on the cylinder 1 of relief opening 13 relative sides, also be provided with two scavenge trunks 6 that are communicated with firing chamber 2 and crankcase 12 on the described cylinder 1, one end opening of described scavenge trunk 6 is to the firing chamber 2, and the other end is communicated with crankcase 12.Shown in Fig. 5-1 and Fig. 5-2, be provided with two symmetrical recess channels 4 on the side surface of described piston 3, the cross section of described recess channels 4 is arc.

When piston 3 is in predetermined piston position (as shown in Figure 3), described recess channels 4 is communicated with respectively two the symmetrical scavenge trunks 6 between engine exhaust port 13 and firing chamber 2 and the crankcase 12, shown in Fig. 4-1, at this moment, the part of the waste gas that stops at relief opening 13 can enter scavenge trunk 6 by recess channels 4, when piston 3 moves downward certain position, relief opening 13 is opened first, gas after the burning is discharged from relief opening 13, piston 3 continues to move downward, scavenging port is opened subsequently, at this moment, because moving downward, piston 3 causes the compressed malleation that becomes of crankcase 12 interior gases, when scavenging port was opened, the EGR waste gas that accumulates in the scavenge trunk 6 was introduced into firing chamber 2 from scavenging port, entered firing chamber 2 by scavenge trunk 6 from scavenging port with Rear Crank Case 12 interior fuel-air mixtures, then piston 3 is up, compresses.

The benefit of this structure is because utilized before this EGR waste gas that imports from relief opening 13 in the scavenge trunk 6 to carry out scavenging, can reduce like this fuel-air mixture of participating in scavenging in the back and enter the amount of relief opening 13, thereby engine emission is improved.

In another embodiment, shown in Fig. 4-2, scavenge trunk 6 is divided into the first scavenging air belt 61 and the second scavenging air belt 62 by next door 20, when piston 3 is in predetermined piston position, described recess channels 4 is communicated with respectively two symmetrical the first scavenging air belts 61 between engine exhaust port 13 and firing chamber 2 and the crankcase 12, thereby making the first scavenging air belt 61 realize at first using the scavenging of EGR waste gas, then is that the air-fuel mixture gas of fuel oil and air carries out scavenging.And EGR waste gas can not enter the second scavenging air belt 62, thereby the second scavenging air belt 62 uses mixed gas to carry out scavenging always.

Although the above is described the utility model in conjunction with figure; but the utility model is not limited to above-mentioned embodiment; above-mentioned embodiment only is schematic; rather than restrictive; those of ordinary skill in the art is under enlightenment of the present utility model; in the situation that does not break away from the utility model aim, can also make a lot of distortion, these all belong within the protection of the present utility model.

Claims

1. two stroke engine, comprise: cylinder (1), a firing chamber (2) of being defined by reciprocating piston (3) is arranged in described cylinder (1), described piston (3) is by the bent axle (14) of connecting rod (11) drive installation in crankcase (12), wherein said cylinder (1) is provided with one for the relief opening (13) of waste gas from the firing chamber discharge, described cylinder (1) also is provided with at least one scavenge trunk (6) that enters firing chamber (2) as air-fuel mixture gas from crankcase (12), one end opening of described scavenge trunk (6) is to the firing chamber (2), the other end is communicated with crankcase (12), it is characterized in that, described motor comprises that also one is communicated with the gas path of scavenge trunk (6) and relief opening (13) at predetermined piston position, and described gas path comprises scavenge trunk (6), relief opening (13) and at least one recess channels (4) that arranges at the side surface of described piston (3).

2. two stroke engine according to claim 1 is characterized in that, described scavenge trunk (6) are divided into the first scavenging air belt (61) and the second scavenging air belt (62) by a next door (20).

3. two stroke engine according to claim 2 is characterized in that, described gas path does not comprise the second scavenging air belt (62).

4. according to claim 1 or 3 described two stroke engines, it is characterized in that described recess channels (4) is two.

5. two stroke engine according to claim 1 is characterized in that, the cross section of described recess channels (4) is arc.