A brush cutter cylinder cover with directional airflow cooling function

Abstract

This utility model belongs to the technical field of brush cutter engine parts, and relates to a brush cutter cylinder cover with directional airflow cooling function. The cylinder cover is installed outside the engine cylinder. A starter is located below the cylinder cover. An air filter is located on the right side of the cylinder, and a muffler is located on the left side. The rear side of the cylinder cover has several vents distributed laterally. A guide plate is provided on the side of the vents near the air filter to block part of the vents, so that the cooling airflow is restricted to flowing out only from the side of the vents near the muffler. The brush cutter cylinder cover with directional airflow cooling function provided by this utility model can better cool the brush cutter engine.

Description

Technical Field

[0001] This utility model belongs to the technical field of brush cutter engine parts, and relates to a brush cutter cylinder cover with directional airflow cooling function. Background Technology

[0002] A brush cutter is a portable gasoline engine-powered machine used by a single person. It is powered by a small two-stroke gasoline engine, which drives the blades or brush cutter head to rotate through a drive shaft to harvest plants and cut shrubs and weeds.

[0003] All handheld gasoline brush cutters must have cylinder covers installed on the outside of the engine cylinder. The purpose is twofold: first, to isolate the high-temperature cylinder from the outside environment, so as not to burn people or animals nearby; second, the special structure inside the cylinder cover allows the vortex generated by the flywheel to flow out through the cylinder blades and outer cylindrical surface, thus providing forced air cooling for the cylinder.

[0004] Chinese invention patent application CN114382587A (publication date: 2022-04-22) discloses a low-fuel-consumption engine for a portable brush cutter, including a cylinder, combustion chamber, piston, crankcase, spark plug, carburetor, choke seat, and air filter. The cylinder is provided with an air inlet, an exhaust port, and a scavenging port. The air inlet is connected to the crankcase and the carburetor. The choke seat is provided with an air inlet leading to the carburetor. A large baffle is provided between the choke seat and the air filter to prevent the atomized fuel mixture from being discharged to the air filter. An oil return groove is provided between the choke seat and the large baffle to store oil droplets formed by the liquefaction of the fuel mixture.

[0005] The aforementioned brush cutter engine has its vents horizontally positioned on the cylinder head, covering the entire cylinder to create a comprehensive ventilation system. The purpose of this is to allow for faster airflow, resulting in better cylinder cooling. However, this comprehensive ventilation system means that some cooling air bypasses the cylinder blades or outer cylindrical surface, flowing directly out from behind the cylinder head and failing to cool the cylinder effectively. More critically, this comprehensive ventilation system fails to cool the starter beneath the cylinder head. Starters, often made of nylon, are prone to sintering and damage if they don't receive sufficient cooling air during high-temperature engine operation. Utility Model Content

[0006] This invention addresses the shortcomings of existing technologies by providing a brush cutter cylinder cover with directional airflow cooling function, which can better cool the brush cutter's engine.

[0007] To solve the above-mentioned technical problems, the objective of this utility model is achieved through the following technical solution: A brush cutter cylinder cover with directional airflow cooling function is provided. The cylinder cover is installed outside the engine cylinder. A starter is installed below the cylinder cover. An air filter is installed on the right side of the cylinder and a muffler is installed on the left side. Several vents are arranged laterally on the rear side of the cylinder cover. A guide plate is provided on the side of the vents near the air filter to block part of the vents, so that the cooling airflow is restricted to flow out only from the side of the vents near the muffler.

[0008] In the above-mentioned brush cutter cylinder cover with directional airflow cooling function, the upper width of the air guide plate is smaller than the lower width, and the edge contour of its blocking area is a continuous sloping surface; the edge contour of the blocking area is the boundary contour between the air guide plate and the ventilation area.

[0009] In the above-mentioned brush cutter cylinder cover with directional airflow cooling function, the distribution center of the ventilation opening coincides with the center plane of the cylinder, and the upper end of the air guide plate is blocked at a position of 30-40% of the width of the ventilation opening; that is, the blocking area of ​​the upper end of the air guide plate is 30-40% of the area of ​​the ventilation opening.

[0010] In the above-mentioned brush cutter cylinder cover with directional airflow cooling function, the lower end of the cylinder cover is closely connected to the starter, and the lower end of the air guide plate has the middle position of the starter as the sealing boundary; that is, the sealing area of ​​the lower end of the air guide plate is 50% of the ventilation area.

[0011] In the above-mentioned brush cutter cylinder cover with directional airflow cooling function, the cylinder cover, vent, and air guide plate are integrally formed; the cylinder cover can be made of plastic or metal.

[0012] In the above-mentioned brush cutter cylinder cover with directional airflow cooling function, the inner wall of the air guide plate is flush with the inner wall of the cylinder cover, forming a continuous airflow plane together.

[0013] In the above-mentioned brush cutter cylinder cover with directional airflow cooling function, a plurality of airflow guide grooves are provided on the airflow guide plane, and the outlet of the airflow guide grooves is oriented toward the starter.

[0014] This utility model also provides a brush cutter, which includes any of the above-mentioned brush cutter cylinder covers with directional airflow cooling function.

[0015] Compared with the prior art, this utility model has the following advantages: 1. This utility model provides a brush cutter cylinder cover with directional airflow cooling function. Based on the traditional ventilation structure, it innovatively adds an air guide plate structure, thereby physically blocking the shortest and most direct leakage path of cooling air. This design effectively forces the cooling air generated by the flywheel to fully flow through the high-temperature cylinder wall and undergo heat exchange before being discharged from the ventilation port near the muffler. This significantly reduces the "short-circuit" dissipation of cooling air, greatly improving the utilization efficiency of cooling air volume and the overall heat dissipation performance of the machine.

[0016] 2. The air guide plate of this utility model can also guide some airflow downwards to achieve directional cooling of the starter, further enhancing the thermal protection of key components. Addressing the temperature distribution characteristics of the cylinder—higher temperature at the top and lower temperature at the bottom—the air guide plate adopts a differentiated sealing area design: less sealing at the top ensures sufficient airflow to cool the high-temperature area; more sealing at the bottom effectively prevents leakage while also cooling the starter, thus making the cooling air distribution more reasonable and optimizing the overall thermal management performance of the system. Attached Figure Description

[0017] Figure 1 This is a perspective view of the present invention (with part of the cylinder cover removed); Figure 2 This is a perspective view of the cylinder cover of this utility model; Reference numerals: 1. Cylinder cover; 2. Cylinder; 3. Starter; 4. Air filter; 5. Muffler; 6. Vent; 7. Air guide plate. Detailed Implementation

[0018] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. See also: Figure 1-2 : A brush cutter cylinder cover with directional airflow cooling function is provided. The cylinder cover 1 covers the outside of the engine cylinder 2. A starter 3 is provided below the cylinder cover 1. An air filter 4 is provided on the right side of the cylinder 2 and a muffler 5 is provided on the left side. A number of vents 6 are arranged laterally on the rear side of the cylinder cover 1. A guide plate 7 is provided on the side of the vents 6 near the air filter 4 to block part of the vents 6, so that the cooling airflow is restricted to flow out only from the side of the vents 6 near the muffler 5.

[0019] like Figure 1 and Figure 2As shown, in this embodiment, based on the traditional cylinder head cover 1, a guide vane 7 is added to the side of the vent 6 near the air filter 4. This structure is essentially a baffle that blocks the cooling air that would otherwise leak directly from here. After adding this sealing structure, the leakage path of ineffective cooling air is effectively blocked, and the airflow is restricted to flowing through the high-temperature cylinder wall 2 for sufficient heat exchange before being discharged from the remaining open ventilation area. This structural modification greatly improves cooling efficiency.

[0020] Furthermore, to address the issue of the upper part of cylinder 2 having a higher temperature than the lower part, the air guide plate 7 employs a design with differentiated sealing areas at the top and bottom: the upper width of the air guide plate 7 is smaller than the lower width, and the edge contour of its sealing area is a continuous sloping surface; the edge contour of the sealing area refers to the boundary contour between the air guide plate 7 and the ventilation area. Through this structure, more cooling airflow can pass through the upper region of cylinder 2.

[0021] This embodiment further provides preferred embodiments of the above structure: Preferably, the distribution center of the vent 6 coincides with the center plane of the cylinder 2, and the upper end of the guide plate 7 has a sealing boundary at a position of 30-40% of the width of the vent 6; that is, the sealing area of ​​the upper end of the guide plate 7 is 30-40% of the area of ​​the vent 6. Preferably, the lower end of the cylinder cover 1 is closely connected to the starter 3, and the lower end of the guide plate 7 has a sealing boundary at the middle position of the starter 3; that is, the sealing area of ​​the lower end of the guide plate 7 is 50% of the area of ​​the vent 6.

[0022] In this embodiment, the cylinder cover 1, the vent 6, and the air guide plate 7 are integrally formed; the cylinder cover 1 can be made of plastic or metal.

[0023] To better cool the starter 3, this embodiment further adds a guiding structure to direct the cooling airflow to the starter 3: the inner wall of the air guide plate 7 is flush with the inner wall of the cylinder cover 1, forming a continuous air guide plane. When the cooling airflow hits the air guide plane, it flows along the air guide plane, thereby guiding a portion of the cooling airflow to the starter 3 below. Preferably, the air guide plane is provided with several air guide grooves, and the outlets of the air guide grooves are set towards the starter 3. By setting the air guide grooves, more cooling airflow can be directed to the starter 3. At the same time, the above structure can also smoothly guide the airflow to change direction, reduce flow resistance, and avoid local eddies or increased wind resistance caused by blocking the vent 6.

[0024] The above embodiments are merely preferred embodiments of the present utility model and are not intended to limit the scope of protection of the present utility model. Therefore, all equivalent changes made to the structure, shape, and principle of the present utility model should be covered within the scope of protection of the present utility model.

Claims

1. A brush cutter cylinder cover with directional air guide cooling function, the cylinder cover (1) covers the outside of the engine cylinder (2), a starter (3) is arranged below the cylinder cover (1), an air filter (4) is arranged on the right side of the cylinder (2), and a silencer (5) is arranged on the left side of the cylinder (2), characterized in that, The rear side of the cylinder cover (1) is provided with a number of vents (6) distributed laterally. A guide plate (7) is provided on the side of the vent (6) near the air filter (4) to block part of the ventilation area, so that the cooling airflow is restricted to flow out only from the side of the vent (6) near the muffler (5).

2. The brush cutter cylinder cover with directional air cooling function according to claim 1, characterized in that, The upper width of the air guide plate (7) is smaller than the lower width, and the edge contour of its blocking area is a continuous sloping surface.

3. The brush cutter cylinder cover with directional air cooling function according to claim 2, characterized in that, The distribution center of the vent (6) coincides with the center plane of the cylinder (2), and the upper end of the air guide plate (7) is blocked at a position of 30-40% of the width of the vent (6).

4. The brush cutter cylinder cover with directional air cooling function according to claim 2, characterized in that, The lower end of the cylinder cover (1) is closely connected to the starter (3), and the lower end of the air guide plate (7) is sealed off at the middle position of the starter (3).

5. The brush cutter cylinder cover with directional air cooling function according to claim 1, characterized in that, The cylinder cover (1), vent (6) and air guide plate (7) are integrally formed.

6. The brush cutter cylinder cover having a directional air cooling function according to claim 1, characterized in that, The inner wall of the air guide plate (7) is flush with the inner wall of the cylinder cover (1), forming a continuous air guide plane.

7. The brush cutter cylinder cover with directional air cooling function according to claim 6, characterized in that, The air guide plane is provided with several air guide grooves, and the outlet of the air guide groove is set towards the starter (3).

8. A brush cutter, characterized in that The brush cutter includes a brush cutter cylinder cover (1) with directional airflow cooling function as described in any one of claims 1-7.

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