Heat dissipation structure and engine

Abstract

The invention 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 has a length direction and a height direction, and the heat dissipation structure is characterized by comprising two heat dissipation assemblies which are arranged in the length direction of the cylinder body in a spaced mode; 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 present invention relates to the technical field of engines, and in particular to a heat dissipation structure and an engine. Background Art

[0002] The heat dissipation method of the engine mainly depends on the cooling system, which can be liquid-cooled or air-cooled.

[0003] Liquid Cooling (Water Cooling): This is the most common cooling method in modern cars and many other types of engines. Liquid cooling systems pump coolant (usually a mixture of water and antifreeze) around the engine through a circulation system. The coolant absorbs the heat generated by the engine and is then directed to the radiator, where it is cooled by the outside air, releasing the heat, and then circulated back to the engine to continue the process.

[0004] Air cooling: Some small engines (such as motorcycles, lawn mowers, etc.) use air cooling systems to dissipate heat. This method uses a fan or natural wind to blow directly through the engine cylinder to remove excess heat. Today's high-power engines are difficult to keep their temperature within the optimal operating temperature range when they are in long standby mode, making it difficult to extend the service life of the engine. Summary of the invention

[0005] In view of the deficiencies in the prior art, the present invention provides a heat dissipation structure and an engine, which solve the technical problem of excessively high engine operating temperature in the prior art.

[0006] According to an embodiment of the present invention, the present invention adopts the following technical solution:

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

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

[0009] An air guide cover is covered in the width direction and the height direction of the cylinder body, a heat dissipation cavity is formed between the air guide cover and the cylinder body, and one of the heat dissipation components and the heat dissipation cavity is configured to form a first heat dissipation channel;

[0010] A muffler front cover is arranged at the end of the heat dissipation cavity along the height direction of the cylinder body, and another heat dissipation component and the muffler front cover are configured to form a second heat dissipation channel;

[0011] The first heat dissipation channel and the second heat dissipation channel are respectively merged into the muffler front cover along different end surfaces thereof and are discharged from the same end surface.

[0012] Preferably, one of the heat dissipation components includes a first exhaust fan arranged on one side of the cylinder body, and the first exhaust fan is provided with a first air inlet communicated with the heat dissipation cavity.

[0013] Preferably, the first exhaust fan is provided with an exhaust hood, and the plurality of groups of air inlets are arranged at intervals along the radial direction of the exhaust hood, and the cross-sectional area of ​​the air inlets gradually shrinks from the edge of the exhaust hood to the center thereof from the outside to the inside.

[0014] Preferably, the first exhaust fan has a blade assembly, and the blade assembly includes main blades and spoilers that are alternately arranged, and the spoiler is provided with a plurality of honeycomb holes.

[0015] Preferably, the cylinder body and / or the air guide cover is provided with a plurality of mounting protrusions, and the plurality of mounting protrusions are arranged at intervals in the heat dissipation cavity for dividing the first heat dissipation channel into a plurality of heat dissipation air ducts, and the ends of the plurality of heat dissipation air ducts all converge on the side of the muffler front cover.

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

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

[0018] Preferably, the other exhaust assembly includes a second exhaust fan arranged on the other side of the cylinder body, and the second exhaust fan is provided with a second air inlet connected to the muffler front cover.

[0019] Preferably, a first air outlet is provided on the side of the muffler front cover, and a second air outlet is provided on the bottom thereof, and 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 vertically.

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

[0022] The present invention also provides an engine, comprising the heat dissipation structure described above.

[0023] Compared with the prior art, the present invention has the following beneficial effects: the heat dissipation structure achieves multiple breakthroughs in efficient cooling, noise control and space optimization through dual-channel zoned heat dissipation, directional air flow guidance of the wind guide cover, and integrated design of the muffler front cover. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 A schematic diagram of an engine heat dissipation structure in one embodiment of the present invention;

[0025] Figure 2 It is a structural schematic diagram of another aspect of the engine heat dissipation structure in one embodiment of the present invention;

[0026] Figure 3 for Figure 2 Cross-sectional view of the middle BB;

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

[0028] Figure 5 for Figure 4 Cross-sectional view of the middle DD;

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

[0030] In the above drawings: 1. cylinder body; 2. air guide cover; 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 cover; 93. main blade; 94. spoiler; 10. mounting protrusion; 11. guide plate; 12. second exhaust fan; 13. second air inlet; 14. guide boss; 15. second heat dissipation channel. DETAILED DESCRIPTION

[0031] In order to make the purpose, technical solution and beneficial effects of the present invention more clearly understood, the technical solution of the present invention is further described below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

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

[0033] Two heat dissipation components are arranged at intervals along the length direction of the cylinder body 1;

[0034] An air guide cover 2 is covered on the cylinder body 1 in the width direction and the height direction, a heat dissipation cavity 21 is formed between the air guide cover 2 and the cylinder body 1, and the heat dissipation assembly and the heat dissipation cavity 21 form a first heat dissipation channel 3;

[0035] A muffler front cover 8 is arranged at the end of the heat dissipation cavity 21 along the height direction of the cylinder body 1, and another heat dissipation component and the muffler front cover 8 are configured to form a second heat dissipation channel 15;

[0036] The first heat dissipation channel 3 and the second heat dissipation channel 15 are respectively merged into the muffler front cover 8 along different end surfaces thereof, and are discharged from the same end surface.

[0037] In this embodiment, two heat dissipation components are arranged at intervals along the length direction of the cylinder body 1, the air guide cover 2 covers the width direction and the height direction of the cylinder body 1, and forms a heat dissipation cavity 21 between the cylinder body 1, a 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 direction of the cylinder body 1 and is connected to the end of the heat dissipation cavity 21, the first heat dissipation channel 3 and the second heat dissipation channel 15 respectively merge into the interior along different end surfaces of the muffler front cover 8 and are discharged from the same end surface. Specifically, a heat dissipation component dissipates the external Cold air is sucked into the heat dissipation cavity 21, carrying the heat of the engine cylinder body 1 to one end of the muffler front cover 8 and dissipating the hot air. Another heat dissipation component sucks the cold air from the outside into the other end of the muffler front cover 8, directly dissipating the heat of the muffler front cover 8. The cold air sucked into the second heat dissipation channel 15 can continuously dilute the hot air remaining in the muffler front cover 8, greatly improving the heat dissipation performance of the engine and the muffler; the two heat dissipation channels converge from different end faces of the muffler front cover 8 (such as the rear end and the lower end), and finally discharge from the same end face (such as the front end), which can integrate the airflow path and reduce turbulence, while combining the muffler function to reduce noise. At the same time, the muffler front cover 8 is arranged at the upper end of the cylinder body 1, following the principle of hot air upward, and can also prevent the discharged hot air from flowing back, thereby improving the heat dissipation effect.

[0038] One of the heat dissipation components includes a first exhaust fan 9 disposed on one side of the cylinder body 1, and the first exhaust fan 9 is provided with a first air inlet 91 connected to the heat dissipation cavity 21. Further, the first exhaust fan 9 is provided with an exhaust hood 92, and a plurality of groups of the air inlets are arranged radially and spaced apart from the exhaust hood 92, and the cross-sectional area of ​​the air inlet gradually shrinks from the edge position of the exhaust hood 92 to the center position from the outside to the inside. Further, the first exhaust fan 9 has a blade assembly, and the blade assembly includes alternating main blades 93 and spoilers 94, and the spoilers 94 are provided with a plurality of honeycomb holes.

[0039] In this embodiment, the first exhaust assembly includes a first exhaust fan 9 provided on the cylinder body 1, and the first exhaust fan 9 is provided with a first air inlet 91 connected to the first heat dissipation channel 3. Multiple groups of radially spaced first air inlets 91 are arranged along the radial intervals of the exhaust cover 92 to form a ring-shaped or radial air intake array, which can avoid airflow concentration or local negative pressure caused by a single air inlet, so that the external air is evenly inhaled and the generation of vortexes is reduced; specifically, when the wind cover is circular, the air inlets are distributed at equal angles along the circumference (such as one is set every 30°), forming a "star-shaped" structure of multi-directional air intake to meet 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, and the Bernoulli effect in fluid mechanics is used to accelerate the airflow when it enters the wind guide cover 2, thereby increasing the air intake per unit time. At the same time, the tapered structure can reduce the risk of airflow separation, maintain the laminar state, and reduce flow noise. The tapered first air inlet 91 should match the rotation direction of the blades of the first exhaust fan 9 (e.g., the inclination angle of the first air inlet 91 is consistent with the inclination angle of the blades), further reducing the air intake resistance and improving the fan working efficiency. The tapered first air inlet 91 generates a dynamic pressure gain when the airflow is accelerated, which can compensate for the pressure loss of the long path heat dissipation cavity 21 and ensure that the airflow still has sufficient kinetic energy when it reaches the remote heat dissipation area. Specifically, 6 groups of first air inlets 91 can be evenly distributed around the exhaust hood 92, and the cross-sectional area of ​​each group of first air inlets 91 shrinks from outside to inside along the airflow direction according to the law of a quadratic curve, with a shrinkage ratio of 60%. Furthermore, the first row fan 9 has a blade assembly, which includes alternating main blades 93 and spoilers 94. The spoiler 94 is provided with a plurality of honeycomb holes (not shown). The main blades 93 and the spoilers 94 are alternately arranged, which can increase the complexity of air flow, make the airflow more uniform and stable, and reduce turbulence and noise. The main blades 93 are responsible for the suction and promotion of external cold air, while the spoilers 94 are used to adjust the direction and speed of the airflow, so that the entire heat dissipation process is more efficient. Specifically, the radial extension length of the main blades 93 can be set to L1, the length of the spoiler 94 can be L2, and L1 / L2=1.5-2.2 is satisfied. By designing the length relationship between the main blades 93 and the spoilers 94, alternating negative pressure zones and accelerated airflow zones can be formed behind the impeller, which greatly improves the air exchange rate in the high-temperature area of ​​the engine cylinder block 1 in the air guide cover 2.The main blades 93 and the spoilers 94 are arranged alternately. The main blades 93 bear the main airflow driving function. The airfoil design (such as arc or wing cross section) determines the wind pressure and flow rate of the fan. The spoiler 94 is located between two adjacent main blades 93, and the airflow is secondary regulated by the honeycomb hole structure. The spoiler 94 can be a flat plate or a slightly curved panel. Its thickness and inclination are complementary to the main blades 93. The main blades 93 and the spoilers 94 are arranged alternately to form a periodic flow pattern of main airflow channel (between main blades 93) → spoiler fine-tuning (spoiler 94 area), breaking the flow inertia of traditional uniform blades and reducing boundary layer separation. Preferably, the honeycomb hole aperture of the spoiler 94 is 0.5-3 mm, the opening rate is 15%-40%, and the spacing between adjacent spoilers 94 and the main blades 93 is 20%-30% of the blade chord length. The honeycomb holes form tiny vortices on the surface of the spoiler 94, which can accelerate the heat exchange between the airflow and the heat dissipation surface; the main blade 93 provides a stable mainstream, and the spoiler 94 generates controllable micro-turbulence through the honeycomb holes, which enhances the airflow's ability to penetrate the boundary layer on the surface of the cylinder 1 and improves the heat dissipation efficiency. This type of design can increase the local heat transfer coefficient by 10% to 15%. Of course, if the spacing between the spoiler 94 and the main blade 93 is too small, it may cause the airflow to interfere with each other. It is necessary to optimize the installation angle of the spoiler 94 (such as 10° to 15° toward the pressure surface of the main blade 93), and the aperture, hole spacing and opening rate of the honeycomb holes need to match the fan speed. For example: in high-speed fans (>5000RPM): small apertures (0.5 to 1mm) and high opening rates (30% to 40%) are used to suppress high-frequency noise; in low-speed fans (<2000RPM), large apertures (2 to 3mm) and low opening rates (15% to 20%) are used to enhance turbulent mixing.

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

[0041] In this embodiment, the mounting protrusion 10 is arranged in the heat dissipation cavity 21 of the cylinder body 1 or the air guide cover 2, and can be a rib, a columnar boss or a guide block. Its height and spacing match the depth of the heat dissipation cavity 21. Multiple mounting protrusions 10 are arranged at intervals to divide the first heat dissipation channel 3 into four independent air ducts to form a "parallel diversion" structure. For example, the mounting protrusions 10 can be evenly distributed along the length direction of the cylinder body 1 to form a transverse air duct. The specific four air ducts are arranged at intervals along the up and down directions to dissipate heat and blow air to different positions of the engine cylinder body 1 (such as up and down, left and right along the cylinder body) (such as the combustion chamber of the cylinder body 1, the piston connecting rod area, and the injector installation position), to achieve precise heat dissipation of "one zone and one air duct". For another example, the cross-sectional area of ​​the air duct in the high heat load area should be the largest, and the ends of the four air ducts should converge into the same side of the muffler front cover 8 to form a centralized exhaust port. The porous silencer structure inside the muffler front cover 8 can be used to simultaneously reduce noise during the exhaust process, while reducing turbulent interference caused by independent exhaust of multiple air ducts.

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

[0043] In this embodiment, the cross-sectional area of ​​the heat dissipation cavity 21 gradually decreases from the head end to the tail end. The airflow is accelerated during the flow due to the reduction in the cross-sectional area of ​​the channel, thereby enhancing the forced convection heat exchange capacity on the surface of the cylinder body 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 the heat exchange efficiency. The guide plate 11 is arranged at the connection between the end of the heat dissipation cavity 21 and the muffler front cover 8. Setting it at an inclination angle (such as 30°~45°) or a curved surface shape (such as an arc transition) can correct the airflow direction and avoid vortices or backflows due to sudden changes in the cross-section.

[0044] Another exhaust assembly includes a second exhaust fan 12 disposed on the other side of the cylinder body 1, and the second exhaust fan 12 is provided with a second air inlet 13 connected to the muffler front cover 8. Further, the side of the muffler front cover 8 is provided with a first air outlet 81, and the bottom surface thereof is provided with a second air outlet 82, and the first air outlet 81 and the second air outlet 82 are respectively connected to the first heat dissipation channel 3 and the second heat dissipation end; the first air outlet 81 and the second air outlet 82 are arranged vertically. Further, a plurality of guide bosses 14 are provided between the first air outlet 81 and the second air outlet 82.

[0045] In this embodiment, a second exhaust fan 12 is arranged on the right side of the cylinder body 1. The specific structure of the second exhaust fan 12 refers to the first exhaust fan 9. The second exhaust fan 12 can be connected to the second air inlet 13 of the muffler front cover 8, which is used to deliver cold air to the muffler front cover 8. The wind of the first exhaust fan 9 is used to dissipate heat to various parts of the engine cylinder body 1. The wind of the second exhaust fan 12 dissipates heat to the air outlet duct in the muffler front cover 8 and the muffler front cover 8 (the air outlet duct is connected to the inside of the engine cylinder) (and takes away the residual wind of the first exhaust fan 9). A first air outlet 81 is arranged on the side of the muffler front cover 8, and a second air outlet 82 is arranged 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. Further, a guide boss 14 is arranged between the first air outlet 81 and the second air outlet 82, which is used to guide the wind discharged from the second air outlet 82 to prevent it from backflowing into the heat dissipation cavity 21.

[0046] Through the heat dissipation structure, the overall temperature of the engine can be kept within a reasonable operating range. Specifically, two engines are used for testing, one is an engine without the heat dissipation structure, and the other is an engine with the heat dissipation structure:

[0047] The operating temperature of the upper cylinder head of the old engine was 91°C, while the temperature of the upper cylinder head of the new engine was 77°C;

[0048] The cylinder head temperature of the old engine was 68 degrees Celsius, and the cylinder head temperature of the new engine was 49 degrees Celsius;

[0049] The temperature of the breather cover plate of the old engine is 65°C, and the temperature of the breather cover plate of the new engine is 48°C;

[0050] The coupling surface temperature of the old engine cylinder head is 87°C, and the original muffler surface temperature of the new engine cylinder head is 73°C.

[0051] The overall test results show that the new engine with heat dissipation structure wind is 12-15℃ lower than the original engine at the same test position.

[0052] The present embodiment also provides an engine, including the heat dissipation structure described above. The specific structure of the engine refers to the above embodiment. Since the present engine adopts all the technical solutions of the above embodiment, it has at least all the beneficial effects brought by the technical solutions of the above embodiment, which will not be described one by one here.

[0053] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the purpose and scope of the technical solution of the present invention, which should be included in the scope of the claims of the present invention.

Claims

1. A heat dissipation structure, applied to an engine, the engine comprising a cylinder block, the cylinder block having a length direction and a height direction, characterized in that: The heat dissipation structure comprises: Two heat dissipation components are arranged at intervals along the length direction of the cylinder body; An air guide cover is covered in the width direction and the height direction of the cylinder body, a heat dissipation cavity is formed between the air guide cover and the cylinder body, and one of the heat dissipation components and the heat dissipation cavity is configured to form a first heat dissipation channel; A muffler front cover is arranged at the end of the heat dissipation cavity along the height direction of the cylinder body, and another heat dissipation component and the muffler front cover are configured to form a second heat dissipation channel; The first heat dissipation channel and the second heat dissipation channel are respectively merged into the muffler front cover along different end surfaces thereof and are discharged from the same end surface.

2. A heat dissipation structure according to claim 1, characterized in that: One of the heat dissipation components includes a first exhaust fan arranged on one side of the cylinder body, and the first exhaust fan is provided with a first air inlet communicated with the heat dissipation cavity.

3. A heat dissipation structure according to claim 2, characterized in that: The first exhaust fan is provided with an exhaust cover, and a plurality of groups of air inlets are arranged at intervals along the radial direction of the exhaust cover, and the cross-sectional area of ​​the air inlets gradually shrinks from the edge position of the exhaust cover to the center position from the outside to the inside.

4. A heat dissipation structure according to claim 2, characterized in that: The first exhaust fan has a blade assembly, which includes main blades and spoilers that are alternately arranged, and the spoiler is provided with a plurality of honeycomb holes.

5. A heat dissipation structure according to any one of claims 1 to 4, characterized in that: The cylinder body and / or the air guide cover are provided with a plurality of mounting protrusions, and the plurality of mounting protrusions are arranged at intervals in the heat dissipation cavity for dividing the first heat dissipation channel into a plurality of heat dissipation air ducts, and the ends of the plurality of heat dissipation air ducts all 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 head end to the tail end; and / or A guide plate is provided at the connection between the end of the heat dissipation cavity and the muffler front cover.

7. The heat dissipation structure according to claim 1, characterized in that: Another of the exhaust components includes a second exhaust fan arranged on the other side of the cylinder body, and the second exhaust fan is provided with a second air inlet connected to the muffler front cover.

8. The heat dissipation structure according to claim 1, characterized in that: A first air outlet is provided on the side of the muffler front cover, and a second air outlet is provided on the bottom thereof, 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 The first air outlet and the second air outlet are arranged vertically.

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

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

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