CN212535844U

CN212535844U - Horizontal water-cooled scooter engine with side water tank

Info

Publication number: CN212535844U
Application number: CN202021678875.4U
Authority: CN
Inventors: 彭昌其
Original assignee: Zhejiang Geely Ming Industrial Co ltd
Current assignee: Zhejiang Geely Ming Industrial Co ltd
Priority date: 2020-08-13
Filing date: 2020-08-13
Publication date: 2021-02-12
Anticipated expiration: 2030-08-13

Abstract

The utility model belongs to the technical field of motorcycle engine, especially, relate to a horizontal water-cooling scooter engine of side water tank. The utility model discloses, to the poor problem of motorcycle engine forced air cooling effect among the prior art, provide a horizontal water-cooling scooter engine of side water tank, including engine subject and the motorcycle cylinder of connection in the engine subject, the motorcycle cylinder includes interconnect's cylinder head and cylinder body, has the combustion chamber in the cylinder body, still is equipped with in the cylinder body can take place the water-cooling cavity of heat exchange with the combustion chamber, still including the circulation water-cooling component who is used for cooling the combustion chamber, is equipped with inlet channel and outlet conduit between circulation water-cooling component and the water-cooling cavity. The utility model discloses be equipped with the circulation water cooling module with motorcycle cylinder intercommunication, the cooling water circulation in the circulation water cooling module passes through the motorcycle cylinder to take place the heat exchange with the motorcycle cylinder, thereby realize the water-cooling to the motorcycle cylinder, guarantee the cooling effect, prolonged the life of engine.

Description

Horizontal water-cooled scooter engine with side water tank

Technical Field

The utility model belongs to the technical field of motorcycle engine, especially, relate to a horizontal water-cooling scooter engine of side water tank.

Background

In modern cities, the motorcycle is used as a convenient and light mass vehicle, and the production technology is mature. However, the engine of the conventional motorcycle still has problems in terms of heat generation and maintenance during the operation process for the user. First, the duty cycle of a motorcycle engine is performed at a high temperature. The temperature of the piston, cylinder head and other parts can be raised by the friction heat generated by the friction of high-temperature gas and moving parts. The high temperature easily causes thermal deformation, reduces the mechanical strength of engine parts, and changes the normal fit clearance due to the excessive thermal expansion. If the motorcycle engine cannot effectively dissipate heat for a long time, the aging of engine parts can be accelerated, and the traveling safety of drivers is influenced. These problems not only affect the working life of the engine, but also greatly increase the workload and the working difficulty of motorcycle drivers in motorcycle maintenance.

Most motorcycles in the prior art are horizontal forced air cooling engines, but the air conductivity of the engine using environment is poor, the cooling effect of a forced air cooling mode is poor, the working temperature of the engine is still overhigh, and the engine is reliable and has poor durability.

For example, chinese utility model patent discloses a motorcycle engine [ application number: 201621049456.8], the utility model comprises a cylinder head, a cylinder body, a left crankcase and a right crankcase; the cylinder head is positioned at the upper part of the cylinder body and connected with the cylinder body, and the top surface of the cylinder head is an inclined cambered surface; the cylinder cooling fins are arranged in parallel on the periphery of the outer side of the cylinder block, and the two side surfaces of the cylinder head are provided with ventilation grooves which extend downwards from the top of the cylinder head to the positions of the cylinder cooling fins on the upper part of the cylinder block; the right crankcase body outer side surface is provided with a raised crankcase cooling fin.

The utility model discloses an adopt the refrigerated mode of forced air cooling promptly, though carried out certain repacking to the engine appearance, its radiating effect still remains to further improve.

SUMMERY OF THE UTILITY MODEL

The utility model aims at the above problem, a horizontal water-cooling scooter engine of side water tank is provided with a water circulative cooling, and the cooling effect is good.

In order to achieve the above purpose, the utility model adopts the following technical proposal:

a horizontal water-cooling scooter engine with a side water tank comprises an engine body and a motorcycle cylinder connected to the engine body, wherein the motorcycle cylinder comprises a cylinder head and a cylinder body which are connected with each other, a combustion chamber is arranged in the cylinder body, a water-cooling cavity capable of exchanging heat with the combustion chamber is further arranged in the cylinder body, the length of the water-cooling cavity is L1, the length of the cylinder body is L2, the cylinder body is integrally formed and L1 is more than 80% of L2, the horizontal water-cooling scooter engine further comprises a circulating water-cooling system for cooling the combustion chamber, a water inlet pipeline and a water outlet pipeline are arranged between the circulating water-cooling system and the water-cooling cavity, two ends of the water inlet pipeline and two ends of the water outlet pipeline are respectively communicated with the water-cooling cavity and the circulating water-cooling system, and cooling water flows into the water.

In the horizontal water-cooled scooter engine with the side water tank, the circulating water-cooling system comprises an installation shell and a water storage tank positioned in the installation shell, one end of the water storage tank is communicated with a water inlet pipeline, the other end of the water storage tank is communicated with a water outlet pipeline, a gas cooling assembly used for improving the gas flow rate on the surface of the water storage tank is further arranged in the installation shell, and the gas cooling assembly is positioned on one side of the water storage tank.

In foretell horizontal water-cooled scooter engine of side water tank, the installation shell body includes water tank dustcoat and right lid, be connected through a plurality of connecting columns between water tank dustcoat and the right lid, the installation cavity is located between water tank dustcoat and the right lid, storage water tank and air-cooled subassembly are all installed in the installation cavity, still have the air inlet window between two adjacent connecting columns, the installation cavity passes through air inlet window and external intercommunication.

In the horizontal water-cooled scooter engine with the side water tank, the air cooling assembly comprises a cooling fan, a crankshaft for driving the cooling fan to rotate, and a water pump communicated with the water inlet pipeline, wherein a pump driving shaft is in driving connection with the water pump, one end of the pump driving shaft, which is far away from the water pump, is meshed with a pump chain, and one end of the pump chain, which is far away from the pump driving shaft, is meshed with one end of the crankshaft, which is far away from the cooling fan; the crankshaft is meshed with the pump chain through the crankshaft driving teeth, the pump driving shaft is meshed with the pump chain through the pump driven teeth, and the gear ratio of the pump driven teeth to the crankshaft driving teeth is 1-1.3.

In the horizontal water-cooled scooter engine with the side water tank, the air cooling assembly further comprises a large starting tooth fixedly connected to the crankshaft, the large starting tooth is located between the crankshaft driving tooth and the cooling fan, the axial lead of the large starting tooth is coincident with the axial lead of the crankshaft, and a decelerating starting tooth is meshed with the side face of the large starting tooth.

In the engine of the horizontal water-cooled scooter with the side water tank, the length L1 of the water-cooled cavity is equal to the length L2 of the cylinder block; the outer surface of the combustion chamber is attached to the inner surface of the water-cooling cavity.

In the engine of the horizontal water-cooled scooter with the side water tank, the combustion chamber is in a hollow cylinder shape, the water-cooled cavities are connected end to end in a circular ring shape, and the ring width of the cross section of each water-cooled cavity is less than one third of the radius of the cross section of the combustion chamber.

In the horizontal water-cooled scooter engine with the side water tank, the water-cooled cavity is respectively communicated with a water inlet channel and a water outlet channel, the water inlet channel is sleeved on the water inlet channel and is communicated with the water inlet channel, the water outlet channel is sleeved on the water outlet channel and is communicated with the water outlet channel, the axial line of the water inlet channel is perpendicular to the axial line of the water-cooled cavity, and the water inlet channel is positioned below the water-cooled cavity.

In the engine of the horizontal water-cooled scooter with the side water tank, the surface of the cylinder body is also provided with a plurality of radiating fins in a protruding manner, and the radiating fins are sequentially arranged along the axial lead of the cylinder body; the radiating fins are connected end to form an annular shape, and the distance between every two adjacent radiating fins is equal.

Compared with the prior art, the utility model has the advantages of:

1. the utility model discloses be equipped with the circulation water cooling system with motorcycle cylinder intercommunication, the cooling water circulation in the circulation water cooling system passes through the motorcycle cylinder to take place the heat exchange with the motorcycle cylinder, thereby realize the water-cooling to the motorcycle cylinder, guarantee the cooling effect, prolonged the life of engine.

2. The utility model discloses still be equipped with the air cooling subassembly that is used for improving storage water tank surface gas flow rate, the air cooling subassembly can improve the radiating rate of storage water tank internal cooling water, reduces the temperature of cooling water, has further guaranteed the cooling effect.

3. The utility model discloses a cylinder block integrated into one piece makes, so compare in welded connection's mode and have better connection stability to make water-cooling cavity's length can be more than two-thirds of cylinder block length, in order to guarantee the heat transfer effect.

Drawings

FIG. 1 is a schematic view of the structure of a motorcycle engine;

FIG. 2 is an exploded view of a portion of the structure of the present invention;

FIG. 3 is a schematic structural view of a part of the structure of the present invention;

FIG. 4 is a schematic structural view of a cylinder of a motorcycle;

FIG. 5 is a cross-sectional view of a cylinder of the motorcycle;

FIG. 6 is an exploded view of a motorcycle cylinder;

in the figure: the motorcycle water cooling system comprises a motorcycle cylinder 1, a circulating water cooling system 2, a water inlet pipeline 3, a water outlet pipeline 4, a radiating fin 5, an ignition plug 6, a cylinder head 11, a cylinder block 12, a combustion chamber 13, a water cooling cavity 14, a water inlet channel 15, a water outlet channel 16, an end cover 17, a ventilation cavity 18, a ventilation opening 19, a mounting outer shell 21, a water storage tank 22, an air cooling assembly 23, an engine main body 100, a water tank outer cover 211, a right cover 212, a mounting cavity 213, a connecting upright post 214, an air inlet window 215, a cooling fan 231, a crankshaft 232, a water pump 233, a pump driving shaft 234, a pump chain 235, a crankshaft driving tooth 236, a pump driven tooth 237, a starting large tooth 238 and a starting.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings and specific embodiments.

Referring to fig. 1-5, a horizontal water-cooled scooter engine with a side water tank comprises an engine body 100 and a motorcycle cylinder 1 connected to the engine body 100, wherein the motorcycle cylinder 1 comprises a cylinder head 11 and a cylinder body 12 which are connected with each other, a combustion chamber 13 is arranged in the cylinder body 12, a water-cooled cavity 14 capable of exchanging heat with the combustion chamber 13 is further arranged in the cylinder body 12, the water-cooled cavity 14 is L1 in length, the cylinder body 12 is L2 in length, the cylinder body 12 is integrally formed and L1 is more than two thirds of L2, the horizontal water-cooled scooter engine further comprises a circulating water-cooling system 2 for cooling the combustion chamber 13, a water inlet pipeline 3 and a water outlet pipeline 4 are arranged between the circulating water-cooling system 2 and the water-cooled cavity 14, two ends of the water inlet pipeline 3 and the water outlet pipeline 4 are respectively communicated with the water-cooled cavity 14 and the circulating water-cooling system 2, and cooling water flows into the water-cooled cavity 14 through the water .

The utility model discloses, during the use, the cooling water in the circulating water cooling system 2 flows into motorcycle cylinder 1 through inlet channel 3 and takes place the heat exchange with combustion chamber 13 in water-cooling cavity 14 promptly, and 4 flows back to the circulating water cooling system 2 in of rethread outlet conduit. The event the utility model discloses be equipped with the circulation water cooling system 2 with motorcycle cylinder 1 intercommunication, the cooling water circulation in the circulation water cooling system 2 passes through motorcycle cylinder 1 to take place the heat exchange with motorcycle cylinder 1, thereby realize the water-cooling to motorcycle cylinder 1, guarantee the cooling effect, prolonged the life of engine.

As shown in fig. 2, the circulating water cooling system 2 includes an installation outer shell 21 and a water storage tank 22 located inside the installation outer shell 21, one end of the water storage tank 22 is communicated with the water inlet pipe 3, the other end is communicated with the water outlet pipe 4, a gas cooling assembly 23 for increasing the gas flow rate on the surface of the water storage tank 22 is further disposed inside the installation outer shell 21, and the gas cooling assembly 23 is located on one side of the water storage tank 22. The utility model discloses still be equipped with the air cooling subassembly 23 that is used for improving storage water tank 22 surface gas flow rate, air cooling subassembly 23 can improve the radiating rate of cooling water in storage water tank 22, reduces the temperature of cooling water, has further guaranteed the cooling effect.

Specifically, the air cooling assembly 23 includes a cooling fan 231, a crankshaft 232 for driving the cooling fan 231 to rotate, and a water pump 233 communicated with the water inlet pipe 3, wherein a pump driving shaft 234 is drivingly connected to the water pump 233, an end of the pump driving shaft 234 away from the water pump 233 is engaged with a pump chain 235, and an end of the pump chain 235 away from the pump driving shaft 234 is engaged with an end of the crankshaft 233 away from the cooling fan 231. The pump drive shaft 234 drives the water pump 233 to deliver cooling water through the water inlet conduit 3 into the motorcycle cylinder 1. The crankshaft 232 drives the cooling fan 231 to rotate, thereby driving the air flow and enhancing the air flow rate on the surface of the water storage tank 22. The pump chain 235 keeps the crankshaft 233 and the pump drive shaft 234 in an interlocked state, that is, the cooling water feed speed and the rotational speed of the cooling fan 231 are both within an appropriate ratio during use. The crankshaft 232 and the cooling fan 231 may be directly or indirectly connected, for example, the crankshaft 232 may drive the magnetic steel rotor to rotate so as to drive the cooling fan 231 to rotate.

Preferably, the crankshaft 233 is engaged with the pump chain 235 through the crankshaft driving teeth 236, the pump driving shaft 234 is engaged with the pump chain 235 through the pump driven teeth 237, and the gear ratio of the pump driven teeth 237 to the crankshaft driving teeth 236 is 1-1.3.

As shown in fig. 3, the air cooling assembly 23 further includes a large start tooth 238 fixedly connected to the crankshaft 232, the large start tooth 238 is located between the crankshaft driving tooth 236 and the cooling fan 231, and the axis of the large start tooth 238 coincides with the axis of the crankshaft 232, so that the driving stability can be ensured. The large start tooth 238 is engaged with a start deceleration tooth 239 on the side. The start reduction teeth 239 may reduce the speed and increase the torque to meet the operating requirements.

As shown in fig. 3, the mounting outer casing 21 includes a water tank housing 211 and a right cover 212, the water tank housing 211 and the right cover 212 are connected by a plurality of connecting posts 214, a mounting cavity 213 is located between the water tank housing 211 and the right cover 212, the water storage tank 22 and the air cooling module 23 are both mounted in the mounting cavity 213, an air inlet window 215 is further provided between two adjacent connecting posts 214, and the mounting cavity 213 is communicated with the outside through the air inlet window 215. That is, the installation cavity 213 is an open cavity, so that the air in the installation cavity 213 can be easily circulated to the outside, thereby enhancing the cooling efficiency of the water storage tank 22.

Preferably, the axes of each connecting post 214 are parallel to each other, which ensures that the support forces provided are parallel to each other, thereby creating a greater resultant force.

As shown in fig. 4-5, the water-cooled cavity 14 has a length L1 equal to the length L2 of the cylinder block 12. Therefore, the heat exchange area can be further enlarged, and the heat exchange effect is improved. The equality of L1 and L2 as used herein is to be understood as being approximately equal, not absolutely equal, because the two ends of the water-cooled cavity 14 are also left with a certain thickness so that the two ends of the water-cooled cavity 14 are closed.

As shown in fig. 5, the outer surface of the combustion chamber 13 is in contact with the inner surface of the water-cooled cavity 14. This can reduce the heat transfer path and improve the heat transfer efficiency.

Preferably, the combustion chamber 13 is a hollow cylinder, the water-cooling cavities 14 are connected end to form a circular ring shape, and the ring width of the cross section of the water-cooling cavity 14 is less than one third of the radius of the cross section of the combustion chamber 13. Thus, a water ring with a larger surface area and a smaller thickness is formed when the cooling water enters the water-cooling cavity 14, and the heat exchange efficiency is ensured.

Referring to fig. 1 and 4, the water-cooling cavity 14 is respectively communicated with a water inlet channel 15 and a water outlet channel 16, the water inlet channel 15 is sleeved with the water inlet pipeline 3 and is communicated with the water inlet channel 15, and the water outlet channel 16 is sleeved with the water outlet pipeline 4 and is communicated with the water outlet channel 16.

When the circulating water cooling system is used, cooling water in the circulating water cooling system 2 flows into the water cooling cavity 14 through the water inlet pipeline 3 and the water inlet channel 15 to exchange heat with the combustion chamber 13, and then flows back into the circulating water cooling system 2 through the water outlet channel 16 and the water outlet pipeline 4. The recirculating water cooling system 2 may be a chilled water storage tank. The utility model discloses be equipped with the circulation water cooling system 2 with motorcycle cylinder 1 intercommunication, the cooling water circulation in the circulation water cooling system 2 passes through motorcycle cylinder 1 to take place the heat exchange with motorcycle cylinder 1, thereby realize the water-cooling to motorcycle cylinder 1, guarantee the cooling effect, prolonged the life of engine.

Preferably, the axis of the water inlet channel 15 is perpendicular to the axis of the water-cooling cavity 14, and the water inlet channel 15 is located below the water-cooling cavity 14. The 90-degree lower end water inlet design can ensure that water inlet is more uniformly distributed, heat exchange is free of dead angles, and installation is facilitated.

As shown in fig. 4, a plurality of radiating fins 5 are protruded from the surface of the cylinder block 12, and the radiating fins 5 are sequentially arranged along the axial line of the cylinder block 12. The heat radiation fins 5 can increase the surface area of the entire cylinder block 12 and increase the heat exchange rate.

Preferably, the radiating fins 5 are connected end to form a ring shape, and the distance between two adjacent radiating fins 5 is equal.

As shown in fig. 4, an ignition plug 6 is further connected to an outer wall of the cylinder block 12 or the cylinder head 11, one end of the ignition plug 6 extends into the combustion chamber 13, and an end cover 17 for closing the combustion chamber 13 is disposed at an end of the cylinder head 11 away from the cylinder block 12. The gas in the combustion chamber 13 is ignited by the ignition plug 6. The provision of the ignition plug 6 on the outer wall of the cylinder block 12 or the cylinder head 11 can facilitate replacement and maintenance of the ignition plug 6.

As shown in fig. 6, a ventilation cavity 18 is further provided in the cylinder block 12 and the cylinder head 11, the ventilation cavity 18 is isolated from the water-cooling cavity 14, a ventilation port 19 is provided on the side wall of the cylinder head 11, one end of the ventilation cavity 18 penetrates through the surface of the cylinder block 12 and is communicated with the outside, and the other end is communicated with the outside through the ventilation port 19. The ventilation hole 19 and the ventilation cavity 18 of external gas accessible circulate promptly, also can play the effect of supplementary heat transfer, nevertheless the utility model discloses the heat transfer process of coolant and combustion chamber 13 in the main heat transfer way still water-cooling cavity 14.

The utility model discloses a theory of operation is: the pump driving shaft 234 drives the water pump 233 to make the cooling water in the water storage tank 22 flow into the water-cooling cavity 14 through the water inlet pipe 3 and the water inlet channel 15 to exchange heat with the combustion chamber 13 under the transportation of the water pump 233, and then flow back into the water storage tank 22 through the water outlet channel 16 and the water outlet pipe 4, the crankshaft 232 drives the cooling fan 231 to increase the air circulation rate in the installation cavity 213 to accelerate the reduction rate of the cooling water temperature in the water storage tank 22, and the above steps are repeated to realize the circulating cooling. The event the utility model discloses be equipped with the circulation water cooling system 2 with motorcycle cylinder 1 intercommunication, the cooling water circulation in the circulation water cooling system 2 passes through motorcycle cylinder 1 to take place the heat exchange with motorcycle cylinder 1, thereby realize the water-cooling to motorcycle cylinder 1, guarantee the cooling effect, prolonged the life of engine.

The specific embodiments described herein are merely illustrative of the spirit of the invention. Various modifications, additions and substitutions for the specific embodiments described herein may be made by those skilled in the art without departing from the spirit of the invention or exceeding the scope of the invention as defined in the accompanying claims.

Although the terms of the motorcycle cylinder 1, the water circulation cooling system 2, the water inlet pipe 3, the water outlet pipe 4, the heat radiating fin 5, the ignition plug 6, the cylinder head 11, the cylinder block 12, the combustion chamber 13, the water cooling cavity 14, the water inlet passage 15, the water outlet passage 16, the end cover 17, the breather cavity 18, the air vent 19, the mounting outer housing 21, the water storage tank 22, the air-cooled component 23, the engine main body 100, the water tank outer cover 211, the right cover 212, the mounting cavity 213, the connecting pillar 214, the air inlet window 215, the cooling fan 231, the crankshaft 232, the water pump 233, the pump drive shaft 234, the pump chain 235, the crankshaft drive teeth 236, the pump driven teeth 237, the start large teeth 238, the start reduction teeth 239, and the like are used more herein, the possibility of using other terms is. These terms are used merely to more conveniently describe and explain the nature of the present invention; they are to be construed in a manner that is inconsistent with the spirit of the invention.

Claims

1. The utility model provides a horizontal water-cooled scooter engine of side water tank, includes engine subject (100) and motorcycle cylinder (1) of connection on engine subject (100), motorcycle cylinder (1) is including interconnect's cylinder head (11) and cylinder block (12), has combustion chamber (13) in cylinder block (12), its characterized in that: still be equipped with in cylinder block (12) and take place water-cooling cavity (14) of heat exchange with combustion chamber (13), the length of water-cooling cavity (14) is L1, and the length of cylinder block (12) is L2, cylinder block (12) integrated into one piece makes and L1 is more than 80% of L2, still including circulating water cooling system (2) that are used for cooling off combustion chamber (13), be equipped with inlet channel (3) and outlet conduit (4) between circulating water cooling system (2) and water-cooling cavity (14), the both ends of inlet channel (3) and outlet conduit (4) are equallyd divide and are do not linked together with water-cooling cavity (14) and circulating water cooling system (2), and cooling water flows into water-cooling cavity (14) through inlet channel (3) and flows back to circulating water cooling system (2) from outlet conduit (4).

2. The lateral water tank horizontal water-cooled scooter engine as claimed in claim 1, wherein: the circulating water cooling system (2) comprises an installation outer shell (21) and a water storage tank (22) located in the installation outer shell (21), one end of the water storage tank (22) is communicated with a water inlet pipeline (3), the other end of the water storage tank is communicated with a water outlet pipeline (4), a gas cooling assembly (23) used for improving the surface gas flow rate of the water storage tank (22) is further arranged in the installation outer shell (21), and the gas cooling assembly (23) is located on one side of the water storage tank (22).

3. The lateral water tank horizontal water-cooled scooter engine as claimed in claim 2, wherein: the installation shell body (21) comprises a water tank outer cover (211) and a right cover (212), the water tank outer cover (211) and the right cover (212) are connected through a plurality of connecting upright posts (214), an installation cavity (213) is located between the water tank outer cover (211) and the right cover (212), the water storage tank (22) and the air cooling assembly (23) are installed in the installation cavity (213), an air inlet window (215) is further arranged between two adjacent connecting upright posts (214), and the installation cavity (213) is communicated with the outside through the air inlet window (215).

4. The lateral water tank horizontal water-cooled scooter engine as claimed in claim 2, wherein: the air cooling assembly (23) comprises a cooling fan (231), a crankshaft (232) used for driving the cooling fan (231) to rotate, and a water pump (233) communicated with the water inlet pipeline (3), wherein a pump driving shaft (234) is in driving connection with the water pump (233), one end, far away from the water pump (233), of the pump driving shaft (234) is meshed with a pump chain (235), and one end, far away from the pump driving shaft (234), of the pump chain (235) is meshed with one end, far away from the cooling fan (231), of the crankshaft (232); the crankshaft (232) is meshed with a pump chain (235) through a crankshaft driving tooth (236), the pump driving shaft (234) is meshed with the pump chain (235) through a pump driven tooth (237), and the tooth ratio of the pump driven tooth (237) to the crankshaft driving tooth (236) is 1-1.3.

5. The side water tank horizontal water-cooled scooter engine as claimed in claim 4, wherein: the air cooling assembly (23) further comprises a large starting tooth (238) fixedly connected to the crankshaft (232), the large starting tooth (238) is located between the crankshaft driving tooth (236) and the cooling fan (231), the axial lead of the large starting tooth (238) is coincident with the axial lead of the crankshaft (232), and a large starting reduction tooth (239) is meshed with the side face of the large starting tooth (238).

6. The lateral water tank horizontal water-cooled scooter engine as claimed in claim 1, wherein: the length L1 of the water-cooling cavity (14) is equal to the length L2 of the cylinder block (12); the outer surface of the combustion chamber (13) is attached to the inner surface of the water-cooling cavity (14).

7. The lateral water tank horizontal water-cooled scooter engine as claimed in claim 6, wherein: the combustion chamber (13) is in a hollow cylindrical shape, the water-cooling cavities (14) are connected end to end in a circular ring shape, and the ring width of the cross section of each water-cooling cavity (14) is less than one third of the radius of the cross section of the combustion chamber (13).

8. The lateral water tank horizontal water-cooled scooter engine as claimed in claim 1, wherein: water-cooling cavity (14) communicate respectively has inhalant canal (15) and exhalant canal (16), and inlet channel (3) cover is established on inhalant canal (15) and is linked together with inhalant canal (15), and exhalant canal (4) cover is established on exhalant canal (16) and is linked together with exhalant canal (16), the axial lead and water-cooling cavity (14) axial lead mutually perpendicular of inhalant canal (15) and inhalant canal (15) are located water-cooling cavity (14) below.

9. The lateral water tank horizontal water-cooled scooter engine as claimed in claim 1, wherein: the surface of the cylinder body (12) is also provided with a plurality of radiating fins (5) in a protruding mode, and the radiating fins (5) are sequentially arranged along the axial lead of the cylinder body (12); the radiating fins (5) are connected end to form an annular shape, and the distance between every two adjacent radiating fins (5) is equal.