CN209800083U - Two-stroke gasoline engine - Google Patents

Abstract

The utility model provides a two-stroke gasoline engine belongs to gasoline engine technical field. It solves the technical problems of low fuel utilization rate of the two-stroke gasoline engine and the like. This two-stroke gasoline engine includes the cylinder, the combustion chamber has in the cylinder, the combustion chamber below has the crankcase, piston that can reciprocating motion has between combustion chamber and the crankcase, it has several scavenging route that the interval distributes to open on the inner wall of cylinder, the air inlet of scavenging route is located the crankcase, the gas outlet of scavenging route communicates to the combustion chamber, still be equipped with the gas vent on the inner wall of cylinder, the gas outlet slant of scavenging route upwards sets up, scavenging route's gas outlet orientation and the radial angle between the direction of piston are 35 at least. The utility model provides a two-stroke gasoline engine optimizes the structural design who sweeps the air flue, increases the gas outlet angle of elevation of sweeping the air flue, lets the gas outlet of sweeping the air flue get into cylinder fresh gas's initial direction towards the combustion chamber, rather than towards the gas vent, can reduce fresh gas's escape by to a great extent like this.

Description

Two-stroke gasoline engine

Technical Field

The utility model belongs to the technical field of the gasoline engine, a two-stroke gasoline engine is related to.

Background

The two-stroke gasoline engine completes one work cycle in two strokes, and the engine works once after the crankshaft rotates for one circle. The two-stroke gasoline engine is different from a four-stroke gasoline engine and has four stages of air intake, compression, combustion and exhaust, the two-stroke gasoline engine inhales air through an air inlet of a cylinder and enters a crankcase, the volume of the crankcase is reduced when a piston is pushed to move downwards by acting, and fresh gas is pressed into the cylinder through a scavenging passage to supply an oil-gas mixture of a combustion chamber by the crankcase. The high-end two-stroke small-displacement gasoline engines on the market examine four large indexes of durability, power, emission, fuel economy and the like, although the two-stroke gasoline engines can do work once per rotation, and the power is larger than four-stroke power; however, the scavenging port of the cylinder of the two-stroke gasoline engine in the prior art is closer to the exhaust port and farther from the combustion chamber due to the structural design, so that a part of newly-entered oil-gas mixture is directly carried out of the exhaust port of the cylinder by high-speed and high-pressure combustion waste gas each time, thereby not only leading part of fuel oil to be lost and reducing the power of the engine, but also leading unburned harmful gas components in the waste gas to be very high and polluting the air and being harmful to human bodies. Therefore, the exhaust emission of the two-stroke gasoline engine is generally far higher than that of the four-stroke gasoline engine with the same displacement.

For example, a Chinese patent (publication number: CN 200952421; published: 2007-09-26; published: A) discloses a two-stroke gasoline engine, which comprises a cylinder body, a piston, a cylinder cavity, a front half crankcase, a rear half crankcase, and a crank chamber consisting of the front half crankcase and the rear half crankcase, wherein the cylinder body is symmetrically provided with a scavenging passage for communicating the crank chamber with the cylinder cavity, the scavenging passage is provided with a guide rib, the scavenging passage is divided into a first scavenging passage and a second scavenging passage by the guide rib, and the cylinder body combination surface of the front half crankcase and the rear half crankcase is provided with an air squeezing hole; at least one pair of scavenging passages on the first scavenging passage and the second scavenging passage is provided with an air squeezing baffle to form a semi-closed structure.

In the gasoline engine disclosed in the above patent document, the angle of elevation of the scavenging passage is small, and the scavenging passage faces the exhaust port of the cylinder, so that fresh gas is likely to flow out from the exhaust port of the cylinder.

Disclosure of Invention

The utility model discloses to the above-mentioned problem that prior art exists, provide a two-stroke gasoline engine, the utility model aims to solve the technical problem that: how to reduce the loss of the newly-entering oil-gas mixture in the two-stroke gasoline engine.

The purpose of the utility model can be realized by the following technical proposal:

The utility model provides a two-stroke gasoline engine, includes the cylinder, the combustion chamber has in the cylinder, the combustion chamber below has the crankcase, piston that can reciprocating motion has between combustion chamber and the crankcase, it has several interval distribution's scavenging route to open on the inner wall of cylinder, scavenging route's air inlet is located the crankcase, scavenging route's gas outlet intercommunication extremely the combustion chamber, still be equipped with the gas vent on the inner wall of cylinder, its characterized in that, scavenging route's gas outlet slant upwards sets up, scavenging route's gas outlet orientation with contained angle between the radial direction of piston is 35 at least.

The working principle is as follows: the combustion chamber in the technical scheme combusts combustible mixed gas, a crankshaft is arranged in a crankcase, when a two-stroke gasoline engine works, a piston ignites from a top dead center to a bottom dead center, combustion in the combustion chamber applies work to push the piston and the crankshaft in the crankcase to act, and the piston exhausts after moving to an exhaust port; meanwhile, the crankcase closes the air inlet, and mixed fresh gas enters the combustion chamber of the cylinder from the upper part of the piston through the scavenging passage after the lower part of the piston is pressurized; and the piston closes all the air inlet and exhaust from the bottom dead center to the top dead center, and compresses the mixed fresh air in the combustion chamber.

The structural design of optimizing scavenging route among this technical scheme increases the gas outlet angle of elevation of scavenging route, lets the initial direction that the gas outlet of scavenging route got into cylinder fresh gas towards the combustion chamber, rather than towards the gas vent, can reduce fresh gas's escape by a great extent like this.

In the two-stroke gasoline engine, the exhaust port is located in the middle of the cylinder, the air outlet of the scavenging passage and the exhaust port are located at the same height, and the air outlet of the scavenging passage and the exhaust port are located on the adjacent side surfaces of the cylinder respectively.

In the two-stroke gasoline engine, an included angle between the direction of the air outlet of the scavenging passage and the radial direction of the piston is at least 35-50 degrees. Preferably, the included angle is 40 ° or 45 °. The conventional scavenging elevation angle is about 5-20 degrees, the elevation angle of an air outlet of the scavenging passage in the technical scheme is obviously increased, so that the direct exhaust mixed gas is reduced by about 35-45 percent under the condition of ensuring that the power is not influenced, and the fuel economy and the tail gas emission value are greatly improved.

In the two-stroke gasoline engine, the air outlet of the scavenging passage is provided with a necking part, and the caliber of the air outlet of the scavenging passage is smaller than the radial size of the middle part of the scavenging passage. The gas outlet of scavenging route among this technical scheme is less than the size of the gas outlet among the prior art, through the minimum cross-sectional area that reduces the gas outlet of scavenging route, the pressure of driving the scavenging down when the piston is unchangeable, when scavenging flow also is unchangeable basically, the fresh gas of this scavenging route's gas outlet department can increase to the velocity of flow of combustion chamber, make fresh gas keep away from the gas vent fast, the part that is taken away directly is just further reduced to gas vent department removal, thereby reduce the emission of unburned gaseous, improve the fuel utilization ratio, reduce air pollution.

In the two-stroke gasoline engine, the scavenging ducts are symmetrically arranged on two sides of the cylinder, two scavenging ducts spaced side by side are arranged on each side, and the exhaust port is located between the scavenging ducts on the two sides.

Compared with the prior art, the utility model provides a two-stroke gasoline engine has following advantage:

1. the utility model provides a two-stroke gasoline engine optimizes the structural design who sweeps the air flue, increases the gas outlet angle of elevation of sweeping the air flue, lets the gas outlet of sweeping the air flue get into cylinder fresh gas's initial direction towards the combustion chamber, rather than towards the gas vent, can reduce fresh gas's escape by to a great extent like this.

2. The utility model provides a two-stroke gasoline engine makes fresh gas flow to the combustion chamber high efficiency through the minimum cross-sectional area that reduces the gas outlet of scavenging way, keeps away from the gas vent fast, and the mixed fresh gas that is taken away by directly will reduce to gas vent department's removal to reduce the direct emission of unburnt gas, improve the fuel utilization ratio, reduce air pollution.

Drawings

FIG. 1 is a schematic view of the two-stroke gasoline engine in a partial sectional view.

Fig. 2 is a cross-sectional view of the present two-stroke gasoline engine from another perspective.

In the figure, 1, cylinder; 11. a scavenging path; 11a, an air inlet; 11b, an air outlet; 12. A combustion chamber; 13. an exhaust port; 2. a crankcase; 3. a crankshaft; 4. a piston.

Detailed Description

The following are specific embodiments of the present invention and the accompanying drawings are used to further describe the technical solution of the present invention, but the present invention is not limited to these embodiments.

As shown in fig. 1 and 2, the two-stroke gasoline engine comprises a cylinder 1, a combustion chamber 12 is arranged in the cylinder 1, a crankcase 2 is arranged below the combustion chamber 12, a piston 4 capable of reciprocating between the combustion chamber 12 and the crankcase 2 is arranged, a plurality of scavenging passages 11 distributed at intervals are formed in the inner wall of the cylinder 1, air inlets 11a of the scavenging passages 11 are located in the crankcase 2, air outlets 11b of the scavenging passages 11 are communicated with the combustion chamber 12, exhaust ports 13 are further arranged in the inner wall of the cylinder 1, air outlets 11b of the scavenging passages 11 are arranged obliquely upwards, and the included angle between the air outlets 11b of the scavenging passages 11 and the radial direction of the piston 4 is at least 35 degrees; the gas vent 13 is located the middle part position of cylinder 1, and the gas outlet 11b and the gas vent 13 of scavenging route 11 are located same high position, and the gas outlet 11b and the gas vent 13 of scavenging route 11 are located the adjacent side of cylinder 1 respectively, and further, scavenging route 11 symmetry sets up in the both sides of cylinder 1, and every side is provided with two scavenging routes 11 of interval side by side, and gas vent 13 is located between the scavenging route 11 of both sides.

In the embodiment, the combustion chamber 12 combusts combustible mixed gas, a crankshaft is arranged in the crankcase 2, when the two-stroke gasoline engine works, the piston 4 ignites from the top dead center to the bottom dead center, the combustion in the combustion chamber 12 does work to push the piston 4 and the crankshaft 3 in the crankcase 2 to act, and the piston 4 exhausts after moving to the exhaust port 13; meanwhile, the crankcase 2 closes the air inlet, and the mixed fresh gas enters the combustion chamber 12 of the cylinder from the upper part of the piston 4 through the scavenging passage 11 after the lower part of the piston 4 is pressurized; from bottom dead center to top dead center, piston 4 closes all intake and exhaust gases and compresses the mixed fresh gas in combustion chamber 12.

In the embodiment, the structural design of the scavenging passage 11 is optimized, the elevation angle of the air outlet 11b of the scavenging passage 11 is increased, and the initial direction of the fresh air entering the cylinder 1 from the air outlet 11b of the scavenging passage 11 faces the combustion chamber 12 instead of the exhaust port 13, so that the escape of the fresh air can be greatly reduced.

As shown in fig. 1, the outlet 11b of the scavenging path 11 is oriented at an angle X with respect to the radial direction of the piston 4, where X is at least 35 ° to 50 °. Preferably, the angle X is 40 ° or 45 °. The conventional scavenging elevation angle is about 5-20 degrees, the elevation angle of the air outlet 11b of the scavenging passage 11 in the embodiment is obviously increased, so that the direct-exhaust mixed gas can be reduced by about 35-45 percent under the condition of ensuring that the power is not influenced, and the fuel economy and the tail gas emission value can be greatly improved.

In the technical scheme, the air outlet 11b of the scavenging passage 11 is provided with a necking part, the radial size of the necking part is Y, and the caliber Y of the air outlet 11b of the scavenging passage 11 is smaller than the radial size of the middle part of the scavenging passage 11. In the embodiment, the size of the air outlet 11b of the scavenging passage 11 is smaller than that of the air outlet 11b in the prior art, and by reducing the minimum cross-sectional area of the air outlet 11b of the scavenging passage 11, when the pressure of scavenging driven by the piston 4 in a downward direction is unchanged and the scavenging flow is basically unchanged, the flow rate of the fresh air at the air outlet 11b of the scavenging passage 11 to the combustion chamber 12 is increased, so that the fresh air is quickly far away from the exhaust port 13, and the part of the fresh air directly taken away by moving to the exhaust port 13 is further reduced, thereby reducing the emission of unburned air, improving the fuel utilization rate and reducing air pollution.

the specific embodiments described herein are merely illustrative of the spirit of the invention. Various modifications or additions may be made to the described embodiments or alternatives may be employed by those skilled in the art without departing from the spirit or ambit of the invention as defined in the appended claims.

Claims (5)

1. A two-stroke gasoline engine comprises a cylinder (1), a combustion chamber (12) is arranged in the cylinder (1), a crankcase (2) is arranged below the combustion chamber (12), a piston (4) capable of reciprocating is arranged between the combustion chamber (12) and the crankcase (2), the inner wall of the cylinder (1) is provided with a plurality of scavenging ducts (11) which are distributed at intervals, an air inlet (11a) of the scavenging duct (11) is positioned in the crankcase (2), an air outlet (11b) of the scavenging passage (11) is communicated with the combustion chamber (12), an exhaust port (13) is also arranged on the inner wall of the cylinder (1), it is characterized in that the air outlet (11b) of the scavenging passage (11) is arranged obliquely upwards, and the direction of an air outlet (11b) of the scavenging passage (11) and the radial direction of the piston (4) form an included angle of at least 35 degrees.

2. The two-stroke gasoline engine according to claim 1, characterized in that the exhaust port (13) is located at the middle position of the cylinder (1), the air outlet (11b) of the scavenging passage (11) is located at the same height position as the exhaust port (13), and the air outlet (11b) of the scavenging passage (11) and the exhaust port (13) are respectively located on the adjacent sides of the cylinder (1).

3. A two-stroke gasoline engine as claimed in claim 1 or 2, characterized in that the outlet opening (11b) of the scavenging duct (11) is directed at an angle of at least 35 ° to 50 ° to the radial direction of the piston (4).

4. The two-stroke gasoline engine as defined in claim 1 or 2, characterized in that the outlet (11b) of the scavenging passage (11) has a constricted portion, and the diameter of the outlet (11b) of the scavenging passage (11) is smaller than the radial dimension of the middle portion of the scavenging passage (11).

5. A two-stroke gasoline engine according to claim 1 or 2, characterized in that the scavenging ducts (11) are symmetrically arranged on both sides of the cylinder (1), two scavenging ducts (11) are arranged on each side in a side-by-side spaced relationship, and the exhaust port (13) is located between the scavenging ducts (11) on both sides.