Heat dissipation structure and engine

Abstract

The utility model provides a heat dissipation structure and an engine, the heat dissipation structure is applied to the engine, the engine comprises a cylinder body, the cylinder body is provided with a length direction and a height direction, the heat dissipation structure is characterized by comprising two heat dissipation assemblies which are arranged at intervals along the length direction of the cylinder body; the air guide cover is arranged in the width direction and the height direction of the cylinder body in a covering mode, a heat dissipation cavity is formed between the air guide cover and the cylinder body, and one heat dissipation assembly and the heat dissipation cavity form a first heat dissipation channel; the silencer front cover is arranged at the tail end of the heat dissipation cavity in the height direction of the cylinder body, and the other heat dissipation assembly and the silencer front cover form a second heat dissipation channel; wherein the first heat dissipation channel and the second heat dissipation channel are converged into the silencer front cover along different end faces of the silencer front cover respectively, and are discharged from the same end face. The technical problem that in the prior art, the working temperature of an engine is too high is solved.

Description

TECHNICAL FIELD

[0001] The utility model relates to an engine technical field especially relates to a heat dissipation structure and engine. BACKGROUND

[0002] The heat dissipation mode of engine mainly depends on cooling system, can be liquid cooling type, also can be air cooling type.

[0003] Liquid cooling type (water cooling type) : this is the most common cooling mode in modern cars and many other types of engine. Liquid cooling system pumps cooling liquid (usually a mixture of water and antifreeze) around the engine through a circulation system. Cooling liquid absorbs the heat generated by the engine, and then is guided to the radiator, where it is cooled by outside air, releases heat, and then recirculates back to the engine to continue the process.

[0004] Air cooling type: some small engines (such as motorcycles, lawn mowers, etc.) use air cooling system to dissipate heat. This way uses fan or natural wind to directly blow through the engine cylinder to take away excess heat. Now, high-power engines are difficult to keep their temperature within the optimal working temperature range during long standby operation, thus difficult to prolong the service life of the engine. SUMMARY

[0005] In view of the deficiencies in the prior art, the utility model provides a heat dissipation structure and engine, which solves the technical problem of high engine operating temperature in the prior art.

[0006] According to the embodiments of the utility model, the following technical scheme is adopted:

[0007] A heat dissipation structure applied to an engine, the engine comprising a cylinder body, the cylinder body having a length direction and a height direction, the heat dissipation structure comprising:

[0008] Two heat dissipation assemblies, arranged at intervals along the length direction of the cylinder body;

[0009] A wind deflector cover, covering the width direction and the height direction of the cylinder body, a heat dissipation cavity being formed between the wind deflector cover and the cylinder body, one of the heat dissipation assemblies and the heat dissipation cavity being configured as a first heat dissipation channel;

[0010] A muffler front cover, arranged at the end of the heat dissipation cavity along the height direction of the cylinder body, the other heat dissipation assembly and the muffler front cover being configured as a second heat dissipation channel;

[0011] Wherein, the first heat dissipation channel and the second heat dissipation channel respectively converge into the muffler front cover from different end faces thereof and discharge from the same end face.

[0012] Preferably, one of the heat dissipation components includes a first row of fans disposed on one side of the cylinder block, the first row of fans having a first air inlet communicating with the heat dissipation cavity.

[0013] Preferably, the first exhaust fan is provided with an exhaust hood, and multiple sets of air inlets are arranged radially at intervals along the exhaust hood, and the cross-sectional area of ​​the air inlets gradually decreases from the edge of the exhaust hood to the center.

[0014] Preferably, the first fan has a fan blade assembly, which includes alternating main blades and deflectors, and the deflectors are provided with a plurality of honeycomb holes.

[0015] Preferably, the cylinder body and / or the air guide shroud are provided with a plurality of mounting protrusions, which are spaced apart in the heat dissipation cavity to divide the first heat dissipation channel into a plurality of heat dissipation air ducts, and the ends of the plurality of heat dissipation air ducts converge on the side of the muffler front cover.

[0016] Preferably, the cross-sectional area of ​​the heat dissipation cavity gradually decreases from its first end to its last end; and / or

[0017] A guide plate is provided at the connection between the end of the heat dissipation cavity and the front cover of the muffler.

[0018] Preferably, another exhaust assembly includes a second exhaust fan located on the other side of the cylinder block, the second exhaust fan having a second air inlet communicating with the front cover of the muffler.

[0019] Preferably, the side of the muffler front cover is provided with a first air outlet, and its bottom surface is provided with a second air outlet, wherein the first air outlet and the second air outlet are respectively connected to the ends of the first heat dissipation channel and the second heat dissipation channel; and / or

[0020] The first air outlet and the second air outlet are arranged perpendicularly.

[0021] Preferably, a plurality of guide protrusions are provided between the first air outlet and the second air outlet.

[0022] This utility model also provides an engine, including the heat dissipation structure described above.

[0023] Compared with the prior art, this utility model has the following beneficial effects: This heat dissipation structure achieves multiple breakthroughs in efficient cooling, noise control and space optimization through dual-channel partitioned heat dissipation, directional airflow guidance hood, and integrated design of silencer front cover. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the engine cooling structure in one embodiment of the present invention;

[0025] Figure 2 This is a schematic diagram of the engine cooling structure from another angle in one embodiment of the present invention;

[0026] Figure 3 for Figure 2 Sectional view of BB;

[0027] Figure 4 This is a schematic diagram of the second heat dissipation path in one embodiment of the present invention;

[0028] Figure 5 for Figure 4 Sectional view of DD;

[0029] Figure 6 This is a schematic diagram of the structure of the muffler cover in one embodiment of the present invention.

[0030] In the above attached figures: 1. Cylinder block; 2. Air guide shroud; 21. Heat dissipation cavity; 3. First heat dissipation channel; 4. First air duct; 5. Second air duct; 6. Third air duct; 7. Fourth air duct; 8. Muffler front cover; 81. First air outlet; 82. Second air outlet; 9. First exhaust fan; 91. First air inlet; 92. Exhaust shroud; 93. Main blade; 94. Baffle; 10. Mounting protrusion; 11. Guide plate; 12. Second exhaust fan; 13. Second air inlet; 14. Guide boss; 15. Second heat dissipation channel. Detailed Implementation

[0031] To make the objectives, technical solutions, and beneficial effects of this utility model clearer, the technical solutions of this utility model are further described below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of this utility model and are not intended to limit it.

[0032] See Figures 1 to 6 A heat dissipation structure is applied to an engine, the engine including a cylinder block 1 having a length direction and a height direction, the heat dissipation structure including:

[0033] Two heat dissipation components are spaced apart along the length of the cylinder 1;

[0034] A wind guide shroud 2 is provided on the cylinder body 1 in the width and height directions. A heat dissipation cavity 21 is formed between the wind guide shroud 2 and the cylinder body 1. One of the heat dissipation components and the heat dissipation cavity 21 are configured to form a first heat dissipation channel 3.

[0035] The muffler front cover 8 is located at the end of the heat dissipation cavity 21 along the height direction of the cylinder 1, and another heat dissipation component is constructed with the muffler front cover 8 to form a second heat dissipation channel 15.

[0036] The first heat dissipation channel 3 and the second heat dissipation channel 15 converge into the muffler front cover 8 along different end faces and discharge from the same end face.

[0037] In this embodiment, two heat dissipation components are spaced apart along the length of the cylinder 1. The air guide shroud 2 covers the width and height of the cylinder 1, forming a heat dissipation cavity 21 between it and the cylinder 1. One heat dissipation component and the heat dissipation cavity 21 constitute a first heat dissipation channel 3, and the other heat dissipation component and the muffler front cover 8 constitute a second heat dissipation channel 15. The muffler front cover 8 is arranged along the height of the cylinder 1 and connected to the end of the heat dissipation cavity 21. The first heat dissipation channel 3 and the second heat dissipation channel 15 converge at different end faces of the muffler front cover 8 and exit from the same end face. Specifically, one heat dissipation component... Cool air from the outside is drawn into the cooling cavity 21, carrying the heat from the engine block 1 to one end of the muffler front cover 8 and expelling the hot air. Another cooling component draws in cool air from the outside to the other end of the muffler front cover 8, directly cooling the muffler front cover 8. The cool air drawn in by the second cooling channel 15 continuously dilutes the residual hot air inside the muffler front cover 8, greatly improving the cooling performance of the engine and muffler. The two cooling channels converge from different end faces (such as the rear and lower ends) of the muffler front cover 8 and finally exit from the same end face, which can integrate the airflow path, reduce turbulence, and reduce noise in conjunction with the muffler function. At the same time, the muffler front cover 8 is located at the upper end of the cylinder block 1, following the principle of hot air rising, which can also prevent the exhaust hot air from flowing back in, improving the cooling effect.

[0038] One of the heat dissipation components includes a first exhaust fan 9 disposed on one side of the cylinder block 1. The first exhaust fan 9 has a first air inlet 91 communicating with the heat dissipation cavity 21. Further, the first exhaust fan 9 has an exhaust shroud 92, and multiple sets of air inlets are radially spaced along the exhaust shroud 92, with the cross-sectional area of ​​the air inlets gradually decreasing from the edge of the exhaust shroud 92 to the center. Further, the first exhaust fan 9 has a fan blade assembly, which includes alternating main blades 93 and baffles 94, with the baffles 94 having multiple honeycomb holes.

[0039] In this embodiment, the first exhaust assembly includes a first exhaust fan 9 disposed on the cylinder 1. The first exhaust fan 9 has a first air inlet 91 connected to the first heat dissipation channel 3. Multiple sets of radially spaced first air inlets 91 are arranged radially at intervals along the exhaust shroud 92, forming an annular or radial air intake array. This avoids airflow concentration or local negative pressure caused by a single air inlet, allowing external air to be drawn in evenly and reducing eddy current generation. Specifically, when the shroud is circular, the air inlets are distributed at equal angles along the circumference (e.g., one every 30°), forming a multi-directional air intake "star" structure to adapt to the air intake requirements under different installation angles. The cross-sectional area of ​​the first air inlet 91 gradually shrinks from the edge to the center. Utilizing the Bernoulli effect in fluid mechanics, the airflow is accelerated when it enters the air guide shroud 2, increasing the air intake volume per unit time. At the same time, the tapering structure can reduce the risk of airflow separation, maintain laminar flow, and reduce flow noise. The tapered first air inlet 91 should match the rotation direction of the first exhaust fan 9 blades (e.g., the tilt angle of the first air inlet 91 is consistent with the blade tilt angle) to further reduce intake resistance and improve fan efficiency. The tapered first air inlet 91 generates dynamic pressure gain when the airflow accelerates, which can compensate for the pressure loss of the long-path heat dissipation cavity 21, ensuring that the airflow still has sufficient kinetic energy when it reaches the far-end heat dissipation area. Specifically, six sets of first air inlets 91 can be evenly distributed around the circumference of the exhaust hood 92. The cross-sectional area of ​​each set of first air inlets 91 contracts from the outside to the inside along the airflow direction according to a quadratic curve law, with a contraction ratio of 60%. Furthermore, the first row of fans 9 has a fan blade assembly, which includes alternating main blades 93 and deflectors 94. The deflectors 94 have multiple honeycomb holes (not shown). The alternating arrangement of the main blades 93 and deflectors 94 can increase the complexity of airflow, making the airflow more uniform and stable, reducing turbulence and noise. The main blades 93 are responsible for driving the intake of external cold air, while the deflectors 94 are used to adjust the airflow direction and speed, making the entire heat dissipation process more efficient. Specifically, the radial extension length of the main blades 93 can be set to L1, and the length of the deflectors 94 can be L2, satisfying L1 / L2 = 1.5-2.2. Through the length relationship design of the main blades 93 and deflectors 94, alternating negative pressure zones and accelerated airflow zones can be formed behind the impeller, greatly improving the air exchange rate in the high-temperature area of ​​the engine block 1 inside the air guide shroud 2.The main blades 93 and spoilers 94 are alternately arranged. The main blades 93 undertake the main airflow driving function. Their airfoil design (such as arc or airfoil cross section) determines the fan's air pressure and flow rate. The spoilers 94 are located between two adjacent main blades 93. They perform secondary airflow regulation through a honeycomb structure. The spoilers 94 can be flat or slightly curved panels. Their thickness and tilt angle complement the main blades 93. The alternating arrangement of the main blades 93 and spoilers 94 forms a periodic flow pattern of main airflow channel (between the main blades 93) → turbulence fine-tuning (spoiler area 94). This breaks the flow inertia of traditional uniform blades and reduces boundary layer separation. Specifically, the honeycomb aperture of the spoilers 94 is 0.5 to 3 mm, the opening ratio is 15% to 40%, and the distance between adjacent spoilers 94 and main blades 93 is 20% to 30% of the blade chord length. The honeycomb holes create micro-vortices on the surface of the baffle 94, accelerating heat exchange between the airflow and the heat dissipation surface. A stable mainstream is provided by the main blade 93, while the baffle 94 generates controllable micro-turbulence through the honeycomb holes, enhancing the airflow's penetration into the boundary layer of the cylinder block 1 and improving heat dissipation efficiency. This design can increase the local heat transfer coefficient by 10%–15%. However, if the distance between the baffle 94 and the main blade 93 is too small, airflow interference may occur. Therefore, the installation angle of the baffle 94 needs to be optimized (e.g., offset towards the pressure surface of the main blade 93 by 10°–15°). The honeycomb hole diameter, hole spacing, and opening ratio must be matched to the fan speed. For example, in high-speed fans (>5000 RPM): small hole diameter (0.5–1 mm) and high opening ratio (30%–40%) are used to suppress high-frequency noise; in low-speed fans (<2000 RPM), large hole diameter (2–3 mm) and low opening ratio (15%–20%) are used to enhance turbulent mixing.

[0040] The cylinder body 1 and the air guide shroud 2 are provided with a plurality of mounting protrusions 10, which are spaced apart in the heat dissipation cavity 21 to divide the first heat dissipation channel 3 into a plurality of heat dissipation air ducts. The ends of the plurality of heat dissipation air ducts converge on the side of the muffler front cover 8.

[0041] In this embodiment, the mounting protrusions 10 are located within the heat dissipation cavity 21 of the cylinder block 1 or the air guide shroud 2. These protrusions can be ribs, columnar bosses, or guide blocks, with their height and spacing matching the depth of the heat dissipation cavity 21. Multiple mounting protrusions 10 are arranged at intervals, dividing the first heat dissipation channel 3 into four independent air ducts, forming a "parallel flow" structure. For example, the mounting protrusions 10 can be equidistantly distributed along the length of the cylinder block 1, forming a transverse air duct. Specifically, the four air ducts are spaced apart vertically to dissipate heat at different locations on the engine cylinder block 1 (such as the combustion chamber, piston connecting rod area, and injector mounting position), achieving precise heat dissipation of "one area, one air duct". Furthermore, for example, the air duct in the high heat load area has the largest cross-sectional area. The ends of the four air ducts converge on the same side of the muffler front cover 8, forming a concentrated exhaust port. Utilizing the porous sound-absorbing structure inside the muffler front cover 8, noise is simultaneously reduced during exhaust, while also reducing turbulence interference caused by independent exhaust from multiple air ducts.

[0042] The cross-sectional area of ​​the heat dissipation cavity 21 gradually decreases from the front end to the rear end; a guide plate 11 is provided at the connection between the rear end of the heat dissipation cavity 21 and the front cover 8 of the muffler.

[0043] In this embodiment, the cross-sectional area of ​​the heat dissipation cavity 21 gradually decreases from the first end to the last end. The airflow accelerates during the flow process due to the decrease in the cross-sectional area of ​​the channel, enhancing the forced convection heat transfer capability on the surface of the cylinder 1. The tapered structure can balance the airflow pressure loss caused by friction and diversion, ensuring that the airflow at the end still has sufficient kinetic energy to enter the muffler front cover 8, thereby improving heat transfer efficiency.

[0044] The guide plate 11 is located at the connection between the end of the heat dissipation cavity 21 and the front cover 8 of the muffler. Setting it at an angle (such as 30° to 45°) or a curved shape (such as a circular arc transition) can correct the airflow direction and avoid eddies or backflow caused by abrupt changes in cross-section.

[0045] Another exhaust assembly includes a second exhaust fan 12 located on the other side of the cylinder 1. The second exhaust fan 12 has a second air inlet 13 that communicates with the muffler front cover 8. Further, the muffler front cover 8 has a first air outlet 81 on its side and a second air outlet 82 on its bottom surface. The first air outlet 81 and the second air outlet 82 are respectively connected to the ends of the first heat dissipation channel 3 and the second heat dissipation channel; the first air outlet 81 and the second air outlet 82 are arranged perpendicularly to each other. Further, a plurality of guide protrusions 14 are provided between the first air outlet 81 and the second air outlet 82.

[0046] In this embodiment, a second row of fans 12 is provided on the right side of the cylinder block 1. The specific structure of the second row of fans 12 is the same as that of the first row of fans 9. The second row of fans 12 can be connected to the second air intake 13 of the muffler front cover 8 to deliver cool air into the muffler front cover 8. The air from the first row of fans 9 is used to dissipate heat from various parts of the engine cylinder block 1. The air from the second row of fans 12 dissipates heat from the air outlet duct and the muffler front cover 8 (the air outlet duct connects to the inside of the engine cylinder) (and removes the residual air from the first row of fans 9). A first air outlet 81 is provided on the side of the muffler front cover 8, and a second air outlet 82 is provided on the bottom. The axes of the two air outlets are orthogonal to avoid mutual interference of exhaust airflow and reduce the risk of backflow. Furthermore, a guide boss 14 is provided between the first air outlet 81 and the second air outlet 82 to guide the air discharged from the second air outlet 82 and prevent it from flowing back into the heat dissipation cavity 21.

[0047] This heat dissipation structure helps maintain the overall engine temperature within a reasonable operating range. Specifically, two engines were tested: one without this heat dissipation structure and the other with it.

[0048] The operating temperature of the upper part of the cylinder head of the old engine is 91℃, while the temperature of the upper part of the cylinder head of the new engine is 77℃.

[0049] The cylinder head temperature of the old engine is 68 degrees Celsius, while the cylinder head temperature of the new engine is 49 degrees Celsius.

[0050] The temperature of the breather cover of the old engine is 65℃, while the temperature of the breather cover of the new engine is 48℃.

[0051] The surface temperature of the cylinder head coupling of the old engine is 87℃, while the surface temperature of the original muffler of the new engine cylinder head is 73℃.

[0052] Overall test results: The new engine with its cooling structure has a temperature 12-15°C lower than the original engine at all the same test locations.

[0053] This embodiment also provides an engine, including the heat dissipation structure described above. The specific structure of the engine is as described in the above embodiment. Since this engine adopts all the technical solutions of the above embodiments, it has at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be described in detail here.

[0054] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model and are not intended to limit it. Although this utility model has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of this utility model without departing from the spirit and scope of the technical solutions of this utility model, and all such modifications or substitutions should be covered within the scope of the claims of this utility model.

Claims

1. A heat dissipation structure applied to an engine, the engine including a cylinder block having a length direction and a height direction, characterized in that, The heat dissipation structure includes: two heat dissipation components spaced apart along the length of the cylinder; an air guide shroud covering the width and height of the cylinder, with a heat dissipation cavity formed between the air guide shroud and the cylinder, one of the heat dissipation components forming a first heat dissipation channel with the heat dissipation cavity; and a muffler front cover located at the end of the heat dissipation cavity along the height of the cylinder, with the other heat dissipation component forming a second heat dissipation channel with the muffler front cover; wherein the first heat dissipation channel and the second heat dissipation channel converge into the muffler front cover along different end faces and exit from the same end face.

2. The heat dissipation structure according to claim 1, characterized in that, One of the heat dissipation components includes a first row of fans disposed on one side of the cylinder block, the first row of fans having a first air inlet communicating with the heat dissipation cavity.

3. The heat dissipation structure according to claim 2, characterized in that, The first exhaust fan is provided with an exhaust hood, and multiple sets of air inlets are arranged radially at intervals along the exhaust hood, and the cross-sectional area of ​​the air inlets gradually decreases from the edge of the exhaust hood to the center.

4. A heat dissipation structure according to claim 2, characterized in that, The first fan has a fan blade assembly, which includes alternating main blades and baffles, and the baffles are provided with multiple honeycomb holes.

5. A heat dissipation structure according to any one of claims 1-4, characterized in that, The cylinder body and / or the air guide shroud are provided with multiple mounting protrusions, which are spaced apart in the heat dissipation cavity to divide the first heat dissipation channel into multiple heat dissipation air ducts. The ends of the multiple heat dissipation air ducts converge on the side of the muffler front cover.

6. A heat dissipation structure according to claim 5, characterized in that, The cross-sectional area of ​​the heat dissipation cavity gradually decreases from the front end to the rear end; and / or a guide plate is provided at the connection between the rear end of the heat dissipation cavity and the front cover of the muffler.

7. A heat dissipation structure according to claim 2, characterized in that, Another heat dissipation component includes a second row of fans located on the other side of the cylinder block, the second row of fans having a second air inlet connected to the front cover of the muffler.

8. A heat dissipation structure according to claim 2, characterized in that, The muffler front cover has a first air outlet on its side and a second air outlet on its bottom surface. The first air outlet and the second air outlet are respectively connected to the ends of the first heat dissipation channel and the second heat dissipation channel; and / or the first air outlet and the second air outlet are arranged perpendicularly to each other.

9. A heat dissipation structure according to claim 8, characterized in that, Multiple guide protrusions are provided between the first air outlet and the second air outlet.

10. An engine, characterized in that, include: The heat dissipation structure according to any one of claims 1-9.

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