Engine cooling system and farmland management machine power device

Abstract

The present invention relates to the technical field of agricultural machinery, and in particular to a farmland management machine. An engine cooling system comprises an engine case, a cylinder block, a starter disk and a centrifugal fan, and also comprises an air guide cover, an upper guide plate and a lower guide plate. The air guide cover is arranged on one side of the case and extends to the side of the cylinder head of the cylinder body. An air cavity for accommodating the centrifugal fan is arranged in the air guide cover, and a heat dissipation hole corresponding to the centrifugal fan is arranged on the side wall of the air cavity; the upper guide plate is installed above the cylinder head, and the lower guide plate is installed below the cylinder head. The sides of the upper guide plate and the lower guide plate are connected to the air guide cover to form an air guide channel connected to the air cavity. The centrifugal fan is driven to rotate in the opposite direction by the engine crankshaft to form a strong wind pressure. Under the action of the wind pressure, the heat generated by the engine cylinder head and the engine case is guided into the wind cavity and discharged to the external environment through the air guide channel formed by the upper guide plate, the lower guide plate and the air guide cover, which can significantly reduce the working temperature and ensure the stable and efficient operation of the power system.

Description

Technical Field

[0001] The present invention relates to the technical field of agricultural machinery, and in particular to a farmland management machine. Background Art

[0002] The farmland management machine is a small farmland farming machinery, which is mainly used in greenhouses, orchards, vegetable fields, greenhouses, hilly slopes and small plots of land (water and dry fields), to perform various tasks such as ditching, ridge forming, tillage, and film covering.

[0003] When operating in narrow or complex terrain, the farm management machine needs to be designed with a compact structure to ensure that the machine can flexibly shuttle between various terrains. However, this compact design often limits the power output mode of the machine. In addition, the farm management machine may need to adjust the speed or torque during operation to adapt to different soil conditions and operating requirements, and conventional forward power often cannot meet the above operating requirements. Therefore, it is necessary to design a reverse power system, that is, when working, the engine power output shaft rotates in the opposite direction. Reversing the power output shaft can make more efficient use of space and reduce unnecessary mechanical changes. Without changing the walking system and speed change system of the terminal product, it can meet the use and operation of the farm management machine, thereby reducing costs and complexity. The reverse function of the output shaft can also be combined with the gear shifting system to achieve more precise speed and torque control, improve operating efficiency and machine performance.

[0004] However, the cooling systems of existing farmland management machines are designed for forward power. When the power output shaft rotates in the opposite direction, the original cooling systems such as the air guide mechanism and the heat dissipation centrifugal fan that rotates synchronously with the engine crankshaft or countershaft will lose their original heat dissipation effect, resulting in excessively high oil temperature and cylinder head temperature, which will affect the service life. Summary of the invention

[0005] In order to solve the problem of poor heat dissipation effect of the reverse-powered farm management machine in the prior art, the present invention provides an engine cooling system and a farm management machine, which is suitable for the reverse-powered farm management machine and has the characteristics of good heat dissipation effect.

[0006] In order to achieve the above objectives, the following technical solutions are provided:

[0007] An engine cooling system comprises an engine case, a cylinder block, a starting disk and a centrifugal fan, and also comprises an air guide cover, an upper guide plate and a lower guide plate. The air guide cover is arranged on one side of the case and extends to the side of the cylinder head of the cylinder block. An air cavity for accommodating the centrifugal fan is arranged in the air guide cover, and heat dissipation holes corresponding to the centrifugal fan are arranged on the side wall of the air cavity. The upper guide plate is installed above the cylinder head, and the lower guide plate is installed below the cylinder head. The sides of the upper guide plate and the lower guide plate are connected to the air guide cover to form an air guide channel connected to the air cavity.

[0008] Furthermore, an involute airflow guide portion is provided at the lower side of the air guide cover extending to the position of the air cavity.

[0009] Furthermore, the lower guide plate is installed below the cylinder head and extends to a side of the cylinder head away from the air guide cover to form a barrier for the side surface of the cylinder head.

[0010] The present invention also provides a power device of a farmland management machine, including an air filter and the above-mentioned engine cooling system, the air filter including an air filter housing, an upper air intake hood, an upper air permeable plate, an air intake pipe, a lower air permeable plate, a filter element and an oil cup; the upper air permeable plate is fixed inside the upper air intake hood, and the inner bottom of the air filter housing is provided with a supporting grid; the outer side of the air intake pipe is connected to the air filter housing, the upper end of the air intake pipe is connected to the upper air permeable plate, the lower end extends into the air filter housing and is connected to the supporting grid, and the oil cup is connected to the bottom of the air filter housing; the lower air permeable plate is connected to the outer side of the air intake pipe in the air filter housing; the filter element is arranged between the lower air permeable plate and the supporting grid; the upper cavity of the air filter housing is provided with an air intake hole connected to the intake manifold of the cylinder body and an exhaust hole connected to the valve chamber upper cover of the cylinder body; the air intake hole and the exhaust hole are located above the upper air permeable plate.

[0011] Furthermore, the filter element is a double-layer sponge, and the double-layer sponge sleeve is arranged on the outside of the air intake pipe.

[0012] Furthermore, it also includes an exhaust system, which includes an exhaust pipe, and the two ends of the exhaust pipe are respectively connected to a first exhaust bend pipe and a second exhaust bend pipe, one end of the first exhaust bend pipe is connected to the exhaust end of the cylinder body through an exhaust manifold, and the other end extends into the exhaust pipe; the second exhaust bend pipe extends out of the exhaust pipe, and the other end extends into the exhaust pipe, and a silencer chamber is provided between the first exhaust bend pipe and the second exhaust bend pipe; the inner end surfaces of the first exhaust bend pipe and the second exhaust bend pipe are both provided with mesh holes.

[0013] Furthermore, a protective cover is provided on the outside of the exhaust pipe, and a heat dissipation mesh is provided on the protective cover.

[0014] The beneficial effects of the present invention are:

[0015] 1. The engine crankshaft is used to drive the centrifugal fan to rotate in the opposite direction to form a strong wind pressure. Under the action of wind pressure, the heat generated by the engine cylinder head and the engine case is guided into the wind cavity and discharged to the external environment through the wind channel formed by the upper guide plate, the lower guide plate and the wind guide cover, which can significantly reduce the working temperature and ensure the stable and efficient operation of the power system.

[0016] 2. The air enters from the upper air intake cover, passes through the upper air permeable plate coarse filtration, the oil cup oil pool oil surface adsorption fine filtration, the lower air permeable plate secondary coarse filtration, and finally passes through the filter element fine filtration before entering the engine combustion chamber. This system greatly improves the filtration efficiency, extends the service life, and ensures the purity of the engine intake.

[0017] 3. The engine exhaust gas enters the exhaust pipe through the exhaust manifold, and is deeply silenced by the silencer chamber in the exhaust pipe and the mesh structure of the exhaust elbow. The airflow channel is long, the silencer effect is good, and the noise of the whole machine is greatly reduced, which meets the user's close-range operation needs and improves the operating comfort. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 The figure is a structural diagram of the power mechanism of the farmland management machine of the present invention;

[0019] Figure 2 This is a structural diagram of the power mechanism of the farmland management machine of the present invention from another angle;

[0020] Figure 3 It is a position structure diagram of the centrifugal fan in the farmland management machine of the present invention;

[0021] Figure 4 It is a structural diagram of the air guide cover and the centrifugal fan in the farmland management machine of the present invention;

[0022] Figure 5 It is a structural diagram of the air guide cover in the farmland management machine of the present invention;

[0023] Figure 6 It is a structural diagram of an air filter in a farmland management machine of the present invention;

[0024] Figure 7 A half-section structural diagram of an air filter in a farmland management machine of the present invention;

[0025] Figure 8 A half-section structural diagram of the exhaust system in the farmland management machine of the present invention

[0026] Fig. 9 It is a structural diagram of the engine case in the farmland management machine of the present invention;

[0027] Fig.10 This is a diagram showing the coordination of the starter flywheel and the igniter in the farmland management machine of the present invention;

[0028] In the figure: 1. engine case; 2. cylinder block; 3. starting plate; 4. centrifugal fan; 5. air guide cover; 6. upper guide plate; 7. lower guide plate; 8. cylinder head; 9. air cavity; 10. heat dissipation hole; 11. involute air flow guide; 12. air filter housing; 13. upper air intake cover; 14. upper air permeable plate; 15. air intake pipe; 16. lower air permeable plate; 17. filter element; 18. oil cup; 19. support grid; 20. air intake hole; 21. exhaust hole; 22. exhaust pipe; 23. first exhaust elbow; 24. second exhaust elbow; 25. protective cover; 26. mesh silencer; 27. starting flywheel; 28. igniter; 29. ​​reduction gear; 30. crankshaft; 31. power shaft; 32. valve chamber cover. DETAILED DESCRIPTION

[0029] The following is a detailed description of an engine cooling system and a farmland management machine of the present invention in conjunction with specific embodiments.

[0030] like Figure 1 , Figure 2 , Figure 3 As shown, an engine cooling system includes an engine case 1, a cylinder block 2, a starter disk 3 and a centrifugal fan 4, and also includes an air guide cover 5, an upper guide plate 6 and a lower guide plate 7. The air guide cover 5 is arranged on one side of the case and extends to the side of a cylinder head 8 of the cylinder block 2. An air cavity 9 for accommodating the centrifugal fan 4 is provided in the air guide cover 5, and a side wall of the air cavity 9 is provided with heat dissipation holes 10 corresponding to the centrifugal fan 4; the upper guide plate 6 is installed above the cylinder head 8, and the lower guide plate 7 is installed below the cylinder head 8. The sides of the upper guide plate 6 and the lower guide plate 7 are connected to the air guide cover 5 to form an air guide channel connected to the air cavity 9.

[0031] like Figure 1 , Fig.10 As shown, when working, the starter disk 3 rotates the starter flywheel by manually pulling the handle, transmitting power to the engine crankshaft to start the engine. At the same time, the starter flywheel drives the magneto to rotate to generate high-voltage current, which is connected to the spark plug through the igniter 28. When the current reaches a certain level, the spark plug generates sparks to ignite the combustible mixture in the cylinder. The engine piston reciprocates under the pressure generated by the combustion of the combustible mixture, driving the crankshaft to rotate and putting the engine into working state. Among them, by redesigning the mechanical angle of the starter flywheel, changing from the existing positive 15° to the reverse 27°, the ignition advance angle of 24° is achieved, which meets the power performance and starting performance of the whole product.

[0032] In this embodiment, if Fig. 9As shown, the engine crankshaft is connected to the power shaft through a speed reduction mechanism, and a pair of speed reduction gears 29 with a difference of one tooth number are arranged in the engine housing 1. The speed reduction gear on the crankshaft has a small number of teeth, and the speed reduction gear on the power shaft has a large number of teeth. The speed reduction structure is compact and the transmission efficiency is high. A mesh is arranged on the shell of the start disk 3 to improve the heat dissipation effect. The power shaft of the engine is connected to the crankshaft in the engine, and the centrifugal fan 4 is connected to the crankshaft. As the power shaft rotates in the opposite direction, the centrifugal fan 4 is driven to rotate and generate wind pressure. The heat generated by the cylinder head 8 and the engine housing 1 enters the wind cavity 9 along the wind guide channel formed by the upper guide plate 6, the lower guide plate 7, and the wind guide cover 5 under the action of wind pressure. The heat is conducted to the external environment through the heat dissipation holes 10 on the start disk 3 by the centrifugal fan 4, which improves the cooling effect, is conducive to reducing the working temperature of the cylinder body 2, the engine housing 1 and the internal oil of the engine housing 1, and ensures the normal operation of the power system. The shape of the upper guide plate 6 matches the shape of the upper part of the cylinder head 8, and covers the upper part of the cylinder head 8, leaving an air guide gap between the upper guide plate 6 and the cylinder head 8; the lower guide plate 7 is installed below the cylinder head 8 and extends to the side of the cylinder head 8 away from the air guide cover 5 to form a side enclosure for the cylinder head 8. The lower guide plate 7 is located at the bottom of the cylinder head 8, and the side of the lower guide plate 7 extends to the side of the cylinder head 8, leaving an air guide gap between the bottom and side of the cylinder head 8.

[0033] like Figure 1 , Figure 4 , Figure 5 As shown, an involute airflow guide portion 11 is provided at the lower side of the air guide cover 5 extending to the position of the air cavity 9. The involute airflow guide portion 11 helps to guide the airflow to flow into the air cavity 9 more smoothly, ensuring that more air flows through the engine cylinder head 8 and the engine case 1, improving the heat dissipation effect and reducing the heat load of the engine.

[0034] The present invention also provides a farmland management machine, such as Figure 1 , Figure 2 , Figure 6 , Figure 7 As shown, it includes an air filter; it also includes the above-mentioned engine cooling system, the air filter includes an air filter housing 12, an upper air intake cover 13, an upper air permeable plate 14, an air intake pipe 15, a lower air permeable plate 16, a filter element 17 and an oil cup 18; the upper air permeable plate 14 is fixed inside the upper air intake cover, and a support grid 19 is provided at the inner bottom of the air filter housing 12; the outer side of the air intake pipe 15 is connected to the air filter housing 12, the upper end of the air intake pipe 15 is connected to the upper air permeable plate 14, and the lower end extends into the air filter housing 12 The interior is connected to the supporting grid 19, and the oil cup 18 is connected to the bottom of the air filter housing 12; the lower air permeable plate 16 is connected to the outer side of the intake pipe 15 inside the air filter housing 12; the filter element 17 is arranged between the lower air permeable plate 16 and the supporting grid 19; the upper cavity of the air filter housing 12 is provided with an intake hole 20 connected to the intake manifold of the cylinder block 2 and an exhaust hole 21 connected to the valve chamber upper cover 32 of the cylinder block 2; the intake hole 20 and the exhaust hole 21 are located above the upper air permeable plate 14.

[0035] like Figure 6 , Figure 7 As shown, during the intake process of the engine, air enters from the upper air intake hood 13, is roughly filtered for dust and impurities in the air through the upper air permeable plate 14, and then passes through the oil pool of the oil cup 18 through the intake pipe 15, and uses the oil surface of the oil pool to absorb and filter smaller dust, and then is roughly filtered again through the lower air permeable plate 16, and is finely filtered through the filter element 17 before entering the cylinder combustion chamber through the intake manifold, which has the advantages of high filtration efficiency and long service life.

[0036] The oil cup 18 is located at the bottom, which can prevent the oil in the oil pool from splashing out and contaminating other equipment in a bumpy working environment.

[0037] The exhaust gas generated during the operation of the engine will return part of the exhaust gas to the air filter through the exhaust pipe, and after mixing with the fresh gas, it will re-enter the cylinder body to participate in combustion, which helps to lower the combustion temperature, reduce the generation of nitrogen oxides, and improve the emission performance of the engine.

[0038] The filter element 17 is a double-layer sponge, which is set on the outside of the air inlet pipe 15. Compared with the paper filter element 17 in the prior art, the sponge filter element 17 has good elasticity and porous structure, is not easy to be blocked, and can maintain stable filtering performance for a long time. The sponge material also has mobile water absorption and can dry the air to a certain extent, while the paper filter element 17 is thin and light, and is easily blocked and damaged by moisture.

[0039] like Figure 8 As shown, it also includes an exhaust system, which includes an exhaust pipe 22, and the two ends of the exhaust pipe are respectively connected to a first exhaust bend pipe 23 and a second exhaust bend pipe 24, one end of the first exhaust bend pipe 23 is connected to the exhaust end of the cylinder body 2 through the exhaust manifold, and the other end extends into the exhaust pipe 22; the second exhaust bend pipe 24 extends out of the exhaust pipe, and the other end extends into the exhaust pipe, and a silencer chamber is provided between the first exhaust bend pipe 23 and the second exhaust bend pipe 24; the inner end surfaces of the first exhaust bend pipe 23 and the second exhaust bend pipe 24 are both provided with meshes.

[0040] In this embodiment, three mesh silencer plates 26 are installed in the silencer cavity, dividing the entire exhaust pipe into four chambers. Exhaust gas generated during the operation of the engine enters the exhaust pipe through the exhaust manifold, and is silenced by the four chambers and mesh structure in the exhaust pipe. The air flow channel is long, the silencer effect is good, and the whole machine has the characteristics of low noise, which can meet the needs of users for close-range operation and comfortable experience.

[0041] A protective cover 25 is provided on the outside of the exhaust pipe, and a heat dissipation mesh is provided on the protective cover 25. On the one hand, the protective cover 25 is used to prevent the exhaust pipe temperature from being too high and scalding the user, and on the other hand, the heat dissipation mesh does not affect the normal heat dissipation of the exhaust pipe.

Claims

1. An engine cooling system, comprising an engine case (1), a cylinder block (2), a starter disc (3) and a centrifugal fan (4), characterized in that: The invention also comprises an air guide cover (5), an upper guide plate (6) and a lower guide plate (7); the air guide cover (5) is arranged on one side of the box body and extends to the side of the cylinder head (8) of the cylinder body (2); an air cavity (9) for accommodating the centrifugal fan (4) is arranged in the air guide cover (5); a heat dissipation hole (10) corresponding to the centrifugal fan (4) is arranged on the side wall of the air cavity (9); the upper guide plate (6) is installed above the cylinder head (8), and the lower guide plate (7) is installed below the cylinder head (8); the side surfaces of the upper guide plate (6) and the lower guide plate (7) are connected to the air guide cover (5) to form an air guide channel connected to the air cavity (9).

2. The engine cooling system according to claim 1, characterized in that: An involute airflow guide portion (11) is provided at the lower side of the air guide cover (5) extending to the position of the air cavity (9).

3. The engine cooling system according to claim 1 or 2, characterized in that: The lower guide plate (7) is installed below the cylinder head (8) and extends to the side of the cylinder head (8) away from the air guide cover (5) to form a barrier on the side of the cylinder head (8).

4. A farmland management machine power device, including an air filter; characterized in that: It also includes the engine cooling system as claimed in any one of claims 1 to 3, wherein the air filter includes an air filter housing (12), an upper air intake cover (13), an upper air permeable plate (14), an air intake pipe (15), a lower air permeable plate (16), a filter element (17) and an oil cup (18); the upper air permeable plate (14) is fixed inside the upper air intake cover (13), and a supporting grid (19) is provided at the inner bottom of the air filter housing (12); the outer side of the air intake pipe (15) is connected to the air filter housing (12), the upper end of the air intake pipe (15) is connected to the upper air permeable plate (14), and the lower end extends into the air filter housing (12); 2) is connected to the support grid (19) inside, and the oil cup (18) is connected to the bottom of the air filter housing (12); the lower air permeable plate (16) is connected to the outer side of the intake pipe (15) inside the air filter housing (12); the filter element (17) is arranged between the lower air permeable plate (16) and the support grid (19); the upper cavity of the air filter housing (12) is provided with an intake hole (20) connected to the intake manifold of the cylinder body (2) and an exhaust hole (21) connected to the valve chamber upper cover (32) of the cylinder body (2); the intake hole (20) and the exhaust hole (21) are located above the upper air permeable plate (14).

5. The farmland management machine power device according to claim 4, characterized in that: The filter element (17) is a double-layer sponge, and the double-layer sponge sleeve is arranged on the outside of the air intake pipe (15).

6. The farmland management machine power device according to claim 4 or 5, characterized in that: The invention also includes an exhaust system, which includes an exhaust pipe (22), the two ends of the exhaust pipe are respectively connected with a first exhaust bend pipe (23) and a second exhaust bend pipe (24), one end of the first exhaust bend pipe (23) is connected with the exhaust end of the cylinder body (2) through the exhaust manifold, and the other end extends into the exhaust pipe (22); the second exhaust bend pipe (24) extends out of the exhaust pipe (22), and the other end extends into the exhaust pipe (22); a silencer chamber is provided between the first exhaust bend pipe (23) and the second exhaust bend pipe (24); mesh holes are provided on the inner end surfaces of the first exhaust bend pipe (23) and the second exhaust bend pipe (24).

7. The farmland management machine power device according to claim 4 or 5, characterized in that: A protective cover (25) is arranged on the outside of the exhaust pipe, and a heat dissipation mesh is arranged on the protective cover (25).

8. The farmland management machine power device according to claim 6, characterized in that: A protective cover (25) is arranged on the outside of the exhaust pipe, and a heat dissipation mesh is arranged on the protective cover (25).

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