CN116353803A - Outboard engine cooling water circulation system - Google Patents

Abstract

The invention discloses an outboard engine cooling water circulation system, which comprises a cold water flowing part, a hot water flowing part and a water-air mixing flowing part; the cold water flowing part comprises a water inlet structure, the water inlet structure comprises a main water channel and an auxiliary water channel which are used for simultaneously feeding water, an included angle between the extending direction of the auxiliary water channel and the extending direction of the main water channel is an acute angle, and the main water channel and the auxiliary water channel are respectively connected with a water pump assembly for pressurizing; the fluid flows through the cold water flowing part, flows through the hot water flowing part and the water-air mixing flowing part for cooling, and is discharged from the outlet of the water-air mixing flowing part. The invention provides an outboard engine cooling water circulation system, which effectively solves the dilemma that the main water channel is blocked and cannot be filled with water through water inlet of the main water channel and the auxiliary water channel.

Description

A cooling water circulation system for an outboard engine

technical field

The invention relates to an outboard engine, in particular to an outboard engine cooling water circulation system.

Background technique

As the power system of water vehicles, outboard motors have been widely used in leisure and entertainment, commercial farming, domestic fishing, flood control and disaster relief, emergency rescue, transportation, water patrol and other fields; outboard motors are mainly composed of engines, transmission, operation , Suspension device and propeller, etc. Once there is insufficient cooling circulating water, or floating objects such as aquatic plants block the water inlet, it will lead to water shortage of the machine, resulting in high temperature of the engine, resulting in cylinder pulling, and the loss of power of the outboard motor. It is life-threatening to the occupants of the ship; in addition, the exhaust system of the outboard engine is quite special, through the internal exhaust channel of the outboard engine, the high-temperature exhaust gas passes through the exhaust pipe of the engine, passes through the water device and then to the underwater device, and finally exhausts the exhaust gas. To the water below 1 meter, this is also very important for the cooling of the exhaust system for the compact outboard motor, and the water circulation cooling system plays a decisive role in the service life of the outboard motor.

The cooling water inlets of traditional outboard motors are located on both sides of the underwater device, the draft is basically within the range of 1 to 2 meters, the cross-sectional area of the water inlet is small, and there is only one main waterway, especially in the complex environment of inland lakes and offshore waters In the process, sundries, floating objects, aquatic plants and other suspended objects are easily absorbed and blocked the water inlet, causing the machine to fail due to water shortage and high temperature, and cannot effectively cope with various complex hydrological environments; the exhaust is carried out through the built-in exhaust channel, and the exhaust pipe The exhaust temperature of the exhaust pipe is between 200°C and 600°C, and the cooling around the exhaust pipe is not good, resulting in high temperature of the underwater exhaust pipe, burning out the gaskets and other components connected to it, and the exhaust cooling is not in place, causing the water shell The local high temperature of the body will affect the service life of the outboard motor.

For example, a "exhaust cooling mechanism for outboard motor" disclosed in Chinese patent literature, its publication number CN215979545U, includes an oil pan and a cooling cylinder located on the upper side of the oil pan; The exhaust cooling mechanism of the outboard motor also includes an exhaust pipe; there is an air inlet on one side of the oil pan, an air outlet on the bottom, and an exhaust port on one side of the cooling cylinder. The air inlet is connected to the exhaust port through an exhaust pipe. The disadvantage is that there is only one main waterway, especially in the complex environment of inland lakes and offshore waters, where sundries, floating objects, aquatic plants and other suspended matter are easily absorbed and blocked the water inlet, causing the machine to fail due to water shortage and high temperature, and unable to effectively deal with various complex conditions. state of the hydrological environment.

Contents of the invention

The purpose of the present invention is to overcome the problem in the prior art that only one main channel water inlet is blocked, which leads to the failure of the machine due to lack of water and high temperature, and provides a cooling water circulation system for outboard motors, which effectively solves the The plight of the main waterway being blocked and unable to enter the water.

In order to achieve the above object, the present invention adopts the following technical solutions:

A cooling water circulation system for an outboard engine, comprising:

The cold water flow part, the cold water flow part includes a water inlet structure, and the water inlet structure includes a main water channel and an auxiliary water channel that simultaneously feed water, the angle between the extending direction of the auxiliary water channel and the extending direction of the main water channel is an acute angle, and the main water channel The water channel and the auxiliary water channel are respectively connected with the water pump assembly for pressurization;

The hot water flow part is used to cool down the working cylinder;

The water-air mixed flow part is used for cooling the exhaust pipe; the fluid first flows through the cold water flow part, then flows through the hot water flow part and the water-air mixed flow part for cooling and cooling, and is discharged from the outlet of the water-air mixed flow part.

By implementing the above-mentioned technical scheme, when the outboard motor starts to run, the engine works, drives the water pump assembly to run, pumps water through the water pump, and the water enters the outboard motor through two channels. The upper water channel (extending in the vertical direction) is transported to the water pump assembly, and the other way is entered by the auxiliary water channel inlet, and flows into the water pump assembly through the auxiliary water channel (auxiliary water channel upper water channel); the water channel in the tank of the hot water flow part Cool the working cylinder, cool down the heat generated by high-temperature and high-pressure combustion in the cylinder, maintain heat balance, and ensure the normal operation of the machine; when the fluid passes through the exhaust pipe of the water-air mixing flow part, it cools down the exhaust pipe ;After cooling the exhaust pipe, hot water and exhaust gas continue to flow downward together, discharged into the water, and then the exhaust gas is discharged into the atmosphere; the water enters through the main and auxiliary water channels, which effectively solves the dilemma that the main water channel is blocked and cannot enter water; On the basis of the original underwater device, an auxiliary waterway device is designed to allow water to continue to enter from the auxiliary waterway when the main waterway of the outboard engine is completely blocked, so as to ensure the normal entry of cooling water and the normal operation of the machine. Improve the service life of the machine.

Preferably, the auxiliary waterway includes an auxiliary waterway inlet pipe, the main waterway includes a main waterway cavity, and the auxiliary waterway cavity is formed in the auxiliary waterway inlet pipe, and the auxiliary waterway cavity communicates with the main waterway cavity. The auxiliary water channel scheme is added to the underwater device, and the auxiliary water channel inlet pipe is pressed into the auxiliary water channel inlet pipe by processing two inclined holes, forming an auxiliary water channel cavity in the auxiliary water channel inlet pipe, which is connected to the main water channel cavity; when the ship is operating normally, the outboard The engine of the machine works, the crankshaft drives the drive shaft to rotate, and the drive shaft runs to drive the water pump assembly to work. When the water pump is working, there are two ways of water entering the main water channel cavity to supply the water pump; one way is through the main water channel water inlet grille The river water is sucked into the cavity of the main waterway; the other way is through the inlet of the auxiliary waterway, through the inlet grille of the auxiliary waterway, through the inlet pipe of the auxiliary waterway, into the cavity of the auxiliary waterway, and then sucked into the cavity of the main waterway, and then pumped by the water pump assembly. The pressurized water flow enters the cooling circulation channel of the engine through the upper water port of the engine; when the machine runs at high speed and encounters debris or garbage and water plants blocking the water inlet grille of the main water channel, due to the high-speed operation, the water pump rotates at a higher speed , the pumping suction generated is very strong, and the blockage will be adsorbed on the surface of the water inlet grille of the main waterway, causing the water inlet of the main waterway to be unable to enter the water. The water inlet pipe enters the cavity of the auxiliary water channel. The inhaled water fills the cavity of the main water channel first, and then is pressurized by the water pump assembly, and the pressurized water flows into the cooling circulation channel of the engine through the upper nozzle of the engine; The phenomenon that the machine cannot supply water due to blockage greatly improves the adaptability of the outboard motor in complex waters, improves the service life of the machine, and adds a backup safety channel for the water inlet of the machine; run concurrently.

Preferably, the water inlet of the main waterway is provided with a main waterway inlet, the water inlet of the auxiliary waterway is provided with an auxiliary waterway inlet, the cold water flow part also includes a base and a drainage side cover, and the hot water flow part It includes a box body, a box cover and an outer cover of a cylinder, and the water-air mixing flow part includes an above-water casing and an underwater casing. When the outboard motor starts to run, the engine works, drives the water pump assembly to run, pumps water through the water pump, and the water enters the outboard motor through two channels. The other path enters from the entrance of the auxiliary water channel, and flows into the water pump assembly through the upper water channel of the auxiliary water channel; the water pump assembly continues to run, and the water drawn from the two water inlets is transported to the base through the water inlet pipe, and the continuously pressurized water flows from the water pump in the base. The circulation water channel enters the drainage side cover, and the water flowing out of the drainage side cover is divided into two parts. 1% of the water flows out through the base and flows into the atmosphere; The cylinder is cooled to cool down the heat generated by high-temperature and high-pressure combustion in the cylinder to maintain heat balance and ensure the normal operation of the machine; the water continues to flow through the tank cover. The water flows out from the thermostat, passes through the outer cover of the cylinder, and then returns to the base, and continues to flow downward through the water casing from the drainage channel of the base, and cools down the exhaust pipe in the water casing while flowing down; After the trachea, the hot water and exhaust gas continue to flow down to the underwater shell, and after passing through the underwater shell, they are discharged into the water through the propeller exhaust channel, and then the exhaust gas is discharged into the atmosphere.

Preferably, a thermostat is provided on the outer cover of the cylinder. The thermostat is a wax-type thermostat. Through the use of the wax-type thermostat, the engine can be quickly heated up in a short period of time through a small circulation system when the engine is running in a cold state, and the abnormal wear of the machine in a cold state can be reduced; in the engine case cover When the water temperature is greater than or equal to 52°C, the thermostat is opened, and the cooling water in the engine circulates into a large cycle. After the thermostat is opened, it flows out to cool down quickly. At the same time, the hot water is removed and flows through the outer wall of the exhaust pipe to cool the exhaust pipe. .

Preferably, an exhaust pipe is provided between the base and the water casing.

Preferably, the water pump assembly is connected to the base through a water inlet pipe, and the base is provided with a drain side cover, and the drain side cover is respectively connected with the base observation water structure and the box, and the base observation water structure is provided with a base Looking at the water, the box is provided with a working cylinder that generates a large amount of heat. Through the use of high-performance water pump assembly components (the water pump components will be dry-grinded and easily damaged under the condition of water shortage, when the cooling effect is good), the wear resistance and mechanical strength of the impeller material of the water pump can be improved, and the whole machine can be improved reliability and durability.

Preferably, the water pump assembly includes a casing, a water pump impeller assembly and a drive shaft, the drive shaft is connected to the engine through a crankshaft spline, the water pump impeller assembly is connected to the drive shaft through a half-round key, and the casing includes shell and a water pump shell, the water pump inner shell is installed in the water pump shell, and the water pump shell is fixed on the underwater shell. The pump impeller assembly is installed in the water pump inner shell, and the water pump assembly is formed by the water pump cover plate and the water pump cover plate gasket; through the rotation of the drive shaft, the water pump impeller assembly also rotates synchronously in the water pump inner shell, and the water flow in the water inlet channel Inhaled and continuously pressurized, it is delivered to the engine through the water inlet pipe to participate in the cooling cycle.

Preferably, the exhaust pipe includes a top of the exhaust pipe and a branch-shaped water guide plate, and the top of the exhaust pipe is provided with a first round hole, a second round hole, a third round hole and a fourth round hole. After passing through the drainage channel of the base, the hot water flowing down passes through the top of the exhaust pipe. The gas passing through the exhaust pipe is engine exhaust gas, and the temperature is very high, generally between 200°C and 600°C. Such a high temperature, in the exhaust The inner cavity of the pipe passes through, and the parts such as the exhaust pipe and the water casing are transferred through heat conduction, and high temperature is transferred, resulting in a reduction in the reliability and life of the machine; but through the present invention, the hot water flowing out of the engine can continue to flow down and pass through The branch-shaped deflector on the outer wall of the pipe forms a hysteresis and slows down the water flow, which completely solves the cooling problem of the exhaust pipe. The structure is ingenious, the cost is low, and the reliability is good; an exhaust pipe device is designed to effectively solve the cooling of the exhaust pipe. Cool down, completely solve the problem of insufficient local high-temperature cooling of the exhaust pipe, and improve the durable service life of the water device.

Preferably, the hot water flows down through the first round hole, the second round hole, the third round hole and the fourth round hole on the exhaust pipe to form hot water droplets. Hot water flows down through the first circular hole, the second circular hole, the third circular hole and the fourth circular hole in the water tank at the upper end of the exhaust pipe to form hot water droplets.

Preferably, the branch-shaped water guide plates are arranged alternately in sequence, and the water flows down slowly in a stepped manner. The hot water droplets are wrapped by the cavity of the water shell, and alternately follow the branch-shaped water guide plates on the exhaust pipe, showing a step-like flow down slowly. Because of the unique structural shape of the branch-shaped water guide plates, the return speed of the hot water droplets is slowed down. At the same time, the alternate layout of the water guide plates of the dendritic structure effectively realizes the cooling of the surface of the exhaust pipe; the design of the exhaust pipe of the dendritic deflector effectively realizes the cooling of the water flow on the outer wall of the exhaust pipe and blocks the heat source from being transferred to the exhaust pipe. The water shell realizes the heat insulation effect and forms a water jacket wrapping cooling.

The invention has the following beneficial effects: (1) Water is fed through the main and auxiliary water channels, effectively solving the dilemma that the main water channels are blocked and unable to enter water. On the basis of the original underwater device, an auxiliary waterway device is designed to allow water to continue to enter from the auxiliary waterway when the main waterway of the outboard engine is completely blocked, so as to ensure the normal entry of cooling water and the normal operation of the machine. Improve the service life of the machine; (2) Design an exhaust pipe device to effectively solve the cooling of the exhaust pipe, completely solve the problem of insufficient local high-temperature cooling of the exhaust pipe, and improve the durable service life of the water device; (3) pass The use of wax-type thermostat controls the engine to heat up rapidly in a short period of time through a small circulation system when the engine is running in a cold state, reducing abnormal wear and tear of the machine in a cold state; after the engine is warmed up, when the water temperature is above 52°C, the thermostat is opened, The cooling water in the engine circulates into a large cycle, and flows out after opening the thermostat for rapid cooling. At the same time, the hot water is discharged and flows through the outer wall of the exhaust pipe to cool the exhaust pipe; (4) through the high-performance water pump assembly Use, improve the wear resistance and mechanical strength of the pump impeller material, and improve the reliability and durability of the whole machine.

Description of drawings

The present invention will be further described below in conjunction with accompanying drawings and examples.

Fig. 1 is an exploded view of the present invention;

Fig. 2 is a working principle diagram of the cooling water circulation of the present invention;

Fig. 3 is the exploded view of water pump in the present invention;

Fig. 4 is the structural representation of exhaust pipe among the present invention;

Fig. 5 is a cooling water circulation working figure of the present invention;

Fig. 6 is a schematic structural view of the secondary channel in the present invention.

In the figure: main waterway entrance 1, main waterway 2, auxiliary waterway entrance 3, auxiliary waterway 4, main waterway inlet grill 4.1, auxiliary waterway inlet grille 4.2, auxiliary waterway inlet pipe 4.3, main waterway cavity 4.4, engine Upper nozzle 4.5, drive shaft 4.6, underwater device 4.7, auxiliary channel cavity 4.8, water pump assembly 5, semicircle key 5.1, drive shaft 5.2, water pump cover plate gasket 5.3, water pump cover plate 5.4, water pump impeller assembly 5.5, inside the water pump Shell 5.6, water pump shell 5.7, water inlet pipe 6, base 7, drain side cover 8, box body 9, box cover 10, thermostat 11, cylinder cover 12, base observation water 13, water shell 14, underwater shell Body 15, propeller exhaust duct 16, exhaust pipe 17, first round hole 17.1, second round hole 17.2, third round hole 17.3, fourth round hole 17.4, exhaust pipe top 17.5, engine exhaust gas 17.6, hot water drop 17.8, branch type water guide plate 17.9, thermostat 18.

Detailed ways

Specific embodiment one:

As shown in Figure 1 or Figure 2 or Figure 5, a cooling water circulation system for an outboard motor, when the outboard motor starts to run, the engine works, drives the water pump assembly 5 to run, pumps water through the water pump, and the water enters the outboard through two channels One way is entered by the main waterway inlet 1, and delivered to the water pump assembly 5 through the main waterway 2 (main waterway upper water channel), and the other way is entered by the auxiliary waterway inlet 3, through the auxiliary waterway 4 (secondary waterway upper water channel) It flows into the water pump assembly 5; the water pump assembly 5 continues to run, and the water drawn from the two water inlets is transported to the base 7 through the water inlet pipe 6, and the continuously pressurized water flows into the drain side cover 8 through the circulation channel in the base 7, and the drain side The moisture that lid 8 flows out has two parts, and the water of 1% flows out through base observation water 13, flows into the atmosphere. 99% of the cooling water enters the tank 9, and cools the working cylinder in the water channel of the tank 9, cools the heat generated by the high temperature and high pressure combustion in the cylinder, maintains the heat balance, and ensures the normal operation of the machine. The water flow continues to flow through the tank cover 10. When the water temperature in the engine tank cover is greater than or equal to 52°C, the thermostat 11 is opened, and the hot water flows out from the thermostat 11, passes through the cylinder outer cover 12, and then flows back to the base 7. From the base 7 The drain channel continues to flow down through the water casing 14, and while flowing down, the exhaust pipe 17 in the water casing 14 is cooled; after cooling the exhaust pipe 17, hot water and exhaust gas continue to flow down to the water The lower casing 15 is discharged into the water through the propeller exhaust channel 16 after passing through the underwater casing 15, and then the waste gas is discharged into the atmosphere. Through the use of thermostat 18 (wax-type thermostat), the engine can be controlled to heat up rapidly in a short period of time through a small circulation system when the engine is running in a cold state, reducing the abnormal wear of the machine in a cold state; after the engine is warmed up, the water temperature is above 52°C When the thermostat 18 is opened, the cooling water in the engine circulates into a large cycle, and the thermostat is opened to flow out for rapid cooling, and at the same time, the hot water is discharged and flows through the outer wall of the exhaust pipe to cool the exhaust pipe; according to Figure 1 As shown in FIG. 2 , the cavity of the exhaust pipe cooling system is formed by the base 7 , the water shell 14 , and the exhaust pipe 17 ; the working principle of the exhaust pipe cooling is shown in FIG. 4 .

Specific embodiment two:

As shown in Figure 3, on the basis of Embodiment 1, when the engine is running, the drive shaft 5.2 is splined through the crankshaft to drive the drive shaft 5.2 to rotate, the water pump inner shell 5.6 is installed in the water pump shell 5.7, and the water pump shell 5.7 is fixed on the On the underwater housing 15. The water pump impeller assembly 5.5 is connected with the drive shaft 5.2 through the half-round key 5.1, the water pump impeller assembly 5.5 is installed in the water pump inner shell 5.6, and the water pump assembly 5 is formed by the water pump cover plate 5.4 and the water pump cover plate gasket 5.3. Through the rotation of the drive shaft 5.2, the water pump impeller assembly 5.5 also rotates synchronously in the water pump inner casing 5.6, sucks the water flow in the water inlet channel and continuously pressurizes it, and delivers it to the engine through the water inlet pipe 6 to participate in the cooling cycle.

Specific embodiment three:

On the basis of Embodiment 1, through the drainage channel of the base 7, the hot water flowing down passes through the top 17.5 of the exhaust pipe (see Figure 4), as shown in Figure 4: the hot water passes through the first water tank in the upper end of the exhaust pipe 17. The round hole 17.1, the second round hole 17.2, the third round hole 17.3 and the fourth round hole 17.4 flow down to form a hot water drop 17.8, and the hot water drop 17.8 is wrapped by the cavity of the water shell 14 and flows along the branch-shaped guide on the exhaust pipe. The water plates 17.9 alternate in turn, presenting a step-like flow down slowly. Because of the unique structural shape of the branch-shaped water guide plates 17.9, the return speed of the hot water droplets 17.8 is slowed down. The cooling of the pipe surface, the gas passing through the exhaust pipe is engine exhaust gas 17.6, the temperature is very high, generally between 200°C and 600°C, such a high temperature, passing through the inner cavity of the exhaust pipe, is harmful to the exhaust pipe and the water shell Parts such as the body are subjected to high temperature transfer through heat conduction, resulting in a reduction in the reliability and life of the machine. But in the present invention, the design of the exhaust pipe 17 of the dendritic deflector 17.9 effectively realizes the cooling of the water flow on the outer wall of the exhaust pipe, blocks the heat source from being transmitted to the water shell 14, realizes the heat insulation effect, and forms a water Wrapped cooling; at the same time, the hot water flowing out of the engine can continue to flow down, and the branch-shaped deflector on the outer wall of the exhaust pipe forms a hysteresis and slows down the water flow, which completely solves the cooling problem of the exhaust pipe. The structure is ingenious and the cost is low. Good reliability.

Specific embodiment four:

On the basis of Embodiment 1, as shown in the schematic diagram of the auxiliary waterway device in Figure 6: the auxiliary waterway scheme is added to the underwater device 4.7, and the auxiliary waterway inlet pipe 4.3 is pressed into the auxiliary waterway inlet pipe by processing two oblique holes. 4.3 forms an auxiliary channel cavity 4.8, which communicates with the main channel cavity 4.4. When the ship is running normally, the engine of the outboard motor works, and the crankshaft drives the drive shaft 4.6 to rotate, and the drive shaft 4.6 runs to drive the water pump assembly 5 to work. When the water pump is working, two channels of water enter the main water channel cavity 4.4 at the same time Supply to the water pump. One way is to suck river water into the main waterway cavity 4.4 through the main waterway inlet grille 4.1; the other way is to pass through the auxiliary waterway inlet 3, pass through the auxiliary waterway inlet grille 4.2, pass through the auxiliary waterway inlet pipe 4.3, and enter the auxiliary waterway cavity 4.8 Then, it is sucked into the main water channel cavity 4.4, and then pressurized by the water pump assembly 5, and the pressurized water flow enters the cooling circulation water channel of the engine through the engine upper nozzle 4.5.

When the machine is running at high speed and there are sundries or rubbish, aquatic plants, etc. blocking the water inlet grille 4.1 of the main waterway, due to the high-speed operation and the high speed of the water pump, the suction force generated is very strong, and the blockage will be adsorbed on the main waterway The surface of the water inlet grille 4.1 prevents water from entering the water inlet of the main waterway. At this time, through the auxiliary waterway inlet 3, through the auxiliary waterway inlet grille 4.2, through the auxiliary waterway inlet pipe 4.3, into the auxiliary waterway cavity 4.8, and is The inhaled water first fills the main water channel cavity 4.4, then pressurizes through the water pump assembly 5, and the pressurized water flow enters the cooling circulation water channel of the engine through the engine upper water port 4.5. In this way, it can effectively avoid the phenomenon that the machine cannot supply water due to the blockage of the main waterway, greatly improve the adaptability of the outboard motor to operate in complex waters, improve the service life of the machine, and add a backup safety channel for the water intake of the machine. The main and auxiliary water channels can be operated independently or simultaneously.

Claims (10)

1. A cooling water circulation system for an outboard engine, characterized in that it comprises: The cold water flow part, the cold water flow part includes a water inlet structure, and the water inlet structure includes a main water channel (2) and an auxiliary water channel (4) that simultaneously feed water, and the extension direction of the auxiliary water channel (4) is the same as that of the main water channel (2) The included angle between the extension direction of is an acute angle, and the main waterway (2) and the auxiliary waterway (4) are respectively connected with the water pump assembly (5) for pressurization; The hot water flow part is used to cool down the working cylinder; The water-air mixed flow part is used for cooling the exhaust pipe; the fluid first flows through the cold water flow part, then flows through the hot water flow part and the water-air mixed flow part for cooling and cooling, and is discharged from the outlet of the water-air mixed flow part. 2. A cooling water circulation system for an outboard engine according to claim 1, characterized in that the auxiliary water channel (4) includes an auxiliary water channel inlet pipe (4.3), and the main water channel (2) includes a main water channel cavity (4.4), the auxiliary waterway cavity (4.8) is formed in the auxiliary waterway inlet pipe (4.3), and the auxiliary waterway cavity (4.8) is connected to the main waterway cavity (4.4). 3. The cooling water circulation system for outboard motors according to claim 2, characterized in that, the water inlet of the main waterway (2) is provided with a main waterway inlet (1), and the secondary waterway (4) is An auxiliary channel inlet (3) is provided at the water inlet, the cold water flow part also includes a base (7) and a drain side cover (8), and the hot water flow part includes a box body (9), a box cover (10) and The cylinder cover (12), the water-air mixed flow part includes an above-water casing (14) and an underwater casing (15). 4. The cooling water circulation system of an outboard engine according to claim 3, characterized in that, a thermostat (11) is provided on the outer cover of the cylinder (12). 5. A cooling water circulation system for an outboard engine according to claim 3 or 4, characterized in that an exhaust pipe (17) is provided between the base (7) and the water shell (14). 6. A cooling water circulation system for an outboard engine according to claim 1 or 2 or 3 or 4, characterized in that the water pump assembly (5) is connected to the base (7) through a water inlet pipe (6), and the The base (7) is provided with a drainage side cover (8), and the drainage side cover (8) is respectively connected with the base observation water structure and the box body (9), and the base observation water structure is provided with a base observation water (13 ), the box body (9) is provided with a working cylinder that generates a large amount of heat. 7. A cooling water circulation system for an outboard engine according to claim 1 or 2 or 3 or 4, characterized in that the water pump assembly (5) includes a housing, a water pump impeller assembly (5.5) and a drive shaft (5.2 ), the drive shaft (5.2) is connected to the engine through a crankshaft spline, the water pump impeller assembly (5.5) is connected to the drive shaft (5.2) through a half-round key (5.1), and the housing includes the water pump inner housing (5.6) and the water pump casing (5.7), the water pump inner casing (5.6) is installed in the water pump casing (5.7), and the water pump casing (5.7) is fixed on the underwater casing (15). 8. A cooling water circulation system for an outboard engine according to claim 5, characterized in that the exhaust pipe (17) includes the top of the exhaust pipe (17.5) and a branch-shaped water guide plate (17.9), the The top of the exhaust pipe (17) is provided with a first round hole (17.1), a second round hole (17.2), a third round hole (17.3) and a fourth round hole (17.4). 9. A cooling water circulation system for an outboard engine according to claim 8, characterized in that hot water passes through the first round hole (17.1), the second round hole (17.2), and the second round hole on the exhaust pipe (7). Three circular holes (17.3) and the fourth circular hole (17.4) flow down to form hot water droplets (8). 10. The cooling water circulation system of an outboard engine according to claim 9, characterized in that, the branch-shaped water guide plates (17.9) are arranged alternately in sequence, and the water flows down slowly in a stepped manner.

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