Forced air cooling structure of motorcycle engine and motorcycle engine

Abstract

The utility model discloses a motorcycle engine forced air cooling structure which comprises an air cylinder body and an air cylinder head fixedly connected to the front end of the air cylinder body, the rear end of the air cylinder head and the front end of the air cylinder body are provided with a dome and a piston hole respectively, the dome and the piston hole can be folded to form a combustion chamber, and the outer side face of the air cylinder body protrudes to form a cylinder sleeve wound on the air cylinder body. A cooling air channel extending in the direction of the center line of the piston hole is formed between the cylinder sleeve and the cylinder body, an air channel inlet and an air channel outlet are formed in the positions, corresponding to the starting end and the tail end of the cooling air channel, of the cylinder sleeve respectively, a fan is fixedly connected to the cylinder head, and an air outlet of the fan is communicated with the air channel inlet of the cooling air channel. The utility model further discloses the motorcycle engine adopting the structure. The engine cooling device is simple in structure and easy to machine and manufacture, the size of the whole engine is reduced, the manufacturing cost is reduced, and meanwhile the cooling effect on the engine is good.

Description

Technical Field

[0001] The utility model relates to the technical field of motorcycle engines, in particular to a motorcycle engine forced air cooling structure and a motorcycle engine. Background Art

[0002] A motorcycle engine is a machine that ignites the fuel mixture that enters the cylinder and converts the heat energy generated by its combustion into mechanical energy, and the crankshaft transmits the power to the rear wheel of the motorcycle through the transmission mechanism to convert it into the driving power of the vehicle. The cooling technology of motorcycle engines is mainly divided into two types: air cooling and water cooling. The air cooling technology mainly dissipates heat through air convection. When the motorcycle is running, the air passes through the heat sink outside the cylinder head to take away the heat inside the cylinder. A cooling air duct is also set up in the cylinder head to assist in heat dissipation. However, if the motorcycle runs at a low speed for a long time, the air flow outside the engine alone is not enough to cool the engine. Excessive temperature will not only increase the failure rate of the engine, but also reduce its service life.

[0003] In order to solve the above problems, the utility model patent with application number 201120038599.X discloses an air guide device for a forced air-cooled vertical motorcycle engine, which has a simple structure, is easy to process, can improve the heat dissipation effect of the engine and is convenient for the installation of spark plugs. It includes a motorcycle engine case, a cylinder block, a cylinder head, a fan and an air guide cover. The fan is installed on one side of the engine case. The air guide cover roughly seals the fan, the cylinder block and the cylinder head therein and forms an air duct between the cover and the engine; the air guide cover is provided with an air inlet on one side of the fan and an air outlet on the other side. The fan actively cools the engine with air, but the air guide cover increases the volume of the entire engine in order to cover the fan, the cylinder block and the cylinder head therein, and the air duct formed also makes the structure more complicated, and also increases the manufacturing cost of the engine. Utility Model Content

[0004] In view of the above-mentioned deficiencies in the prior art, the technical problem to be solved by the utility model is: how to provide a motorcycle engine forced air cooling structure with simple structure, low processing and manufacturing cost and good engine heat dissipation effect.

[0005] In order to solve the above technical problems, the utility model adopts the following technical solutions:

[0006] A forced air cooling structure for a motorcycle engine comprises a cylinder block and a cylinder head fixedly connected to the front end of the cylinder block, the rear end of the cylinder head and the front end of the cylinder block are respectively provided with a dome and a piston hole which can be closed to form a combustion chamber, and the characteristic is that a cylinder sleeve which is wound around the cylinder block is formed on the outer side surface of the cylinder block, a cooling air duct extending around the center line direction of the piston hole is formed between the cylinder sleeve and the cylinder block, an air duct inlet and an air duct outlet are respectively provided at positions corresponding to the starting end and the end end of the cooling air duct on the cylinder sleeve, a fan is fixedly connected to the cylinder head, and the air outlet of the fan is connected to the air duct inlet of the cooling air duct.

[0007] The working process of a motorcycle engine is a cyclic process of converting fuel into power, that is, the fuel burns in the combustion chamber, and the reciprocating drive of the piston is realized by controlling the intake valve and the exhaust valve. The fuel burns in the combustion chamber, and the piston hole accounts for a large proportion in the combustion chamber, so the main heat is concentrated and radiated on the cylinder body. In the utility model, forced air cooling is mainly performed on the cylinder body with large heat, so a cylinder sleeve is arranged on the outer side of the cylinder body to form a cooling air duct extending around the piston hole between the cylinder body and the cylinder sleeve. After the fan is started, an air flow is formed in the cooling air duct to actively take away the heat. At the same time, the external air flow during the driving process of the motorcycle will also dissipate heat to the cylinder body and the cylinder head, further enhancing the heat dissipation effect. In addition, the cylinder head and the cylinder body are connected together. After the fan cools down the cylinder body, after the temperature of the cylinder head is higher than the temperature of the cylinder body, the cylinder head will also transfer heat to the cylinder body, and the cylinder body is used to enhance the heat dissipation.

[0008] As an optimization, a camshaft chamber is provided at the front end of the cylinder head, a camshaft is provided in the camshaft chamber, and both ends of the camshaft are rotatably connected to the wall of the camshaft chamber. The fan is correspondingly provided at one end of the camshaft along its axial direction, and the end of the camshaft corresponding to the fan side passes out of the cylinder head and extends into the fan to be connected to the fan's impeller. The up and down movement of the piston is connected to the camshaft through a series of gears or chains and drives the camshaft to rotate, and the rotation of the camshaft can drive the fan's impeller to rotate, so that as long as the engine is working, the fan will continue to run, and there is no need to set up a separate motor to drive the fan, which also reduces the volume of the entire engine.

[0009] As an optimization, the cylinder block and the cylinder head are fixedly connected together by fixing bolts, and the outer surface of the cylinder block and the position located in the cooling air duct are formed with a plurality of protrusions at intervals along the extension direction of the cooling air duct, and the protrusions are respectively formed as an integral structure with the cylinder block and the cylinder liner, and the position corresponding to the protrusion on the cylinder liner is provided with a connecting hole passing through the cylinder liner and the protrusion, and the fixing bolt passes through the connecting hole and is threadedly connected to the cylinder head. The protrusion is formed in the cooling air duct, and the cross-sectional area of ​​the cooling air duct at the position of the protrusion will become smaller. According to Bernoulli's principle, when a fluid passes through an area with a reduced cross-sectional area, in order to maintain mass conservation, the velocity of the fluid must increase, that is, the cooling effect on the cylinder block can be further improved.

[0010] As an optimization, the arc structure formed by the cooling air duct extending around the center line of the piston hole is an optimal arc structure, which increases the contact area with the cylinder body.

[0011] As an optimization, the front end of the cylinder block is convexly formed with a boss, the rear end of the cylinder head is provided with an abutting surface parallel to the top surface of the boss, a metal heat conductive pad having the same shape as the top surface of the boss is provided between the boss and the abutting surface, and the boss and the abutting surface are respectively pressed against the side surfaces of the metal heat conductive pad. When a temperature difference occurs between the cylinder block and the cylinder head, the metal heat conductive pad can better transfer the heat of the cylinder head to the cylinder block for heat dissipation.

[0012] As an optimization, the fan is a centrifugal fan.

[0013] As an optimization, a plurality of heat dissipation fins are protruded from the cylinder head and the cylinder body respectively to increase the heat dissipation capacity.

[0014] As an optimization, two valve holes connected to the dome are formed on the cavity wall of the camshaft chamber, an outlet flow channel is formed on the side of the cylinder head facing away from the fan and between the dome and the camshaft chamber, the outlet flow channel extends toward the side where the fan is located and passes through the position between the two valve holes, an outlet hole connected to the outlet flow channel is formed at the position of the cylinder head corresponding to the outlet end of the outlet flow channel, a spark plug hole connected to the dome is formed at the outlet hole, an inlet flow channel is formed at one end of the outlet flow channel facing the fan side and extending toward the upper end or the lower end of the cylinder head, and an inlet flow channel is formed at one end of the inlet flow channel away from the outlet flow channel, and an inlet end capable of inletting air through the front of the cylinder head is provided. The heat dissipation channel arranged inside the cylinder head can not only enhance the heat dissipation of the cylinder head, but also cool the piston installed at the spark plug hole, so that the resistance value of the spark plug remains stable, thereby ensuring that its ignition efficiency will not be attenuated due to the high temperature of the cylinder head.

[0015] The utility model also discloses a motorcycle engine, comprising the above-mentioned motorcycle engine forced air cooling structure.

[0016] Compared with the prior art, the utility model has the following beneficial effects: the utility model has a simple structure, is easy to manufacture, reduces the volume of the entire engine, reduces the manufacturing cost, and has a good cooling effect on the engine. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 The three-dimensional structure of the utility model is shown in FIG. Figure Ⅰ ;

[0018] Figure 2 The three-dimensional structure of the utility model is shown in FIG. Figure II ;

[0019] Figure 3 It is a cross-sectional schematic diagram of the cylinder body in the utility model;

[0020] Figure 4 It is a cross-sectional schematic diagram of the cylinder head in the utility model. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical scheme and advantages of the embodiment of the utility model clearer, the technical scheme in the embodiment of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiment of the utility model. Obviously, the described embodiment is a part of the embodiment of the utility model, not all of the embodiments. The components of the embodiment of the utility model generally described and shown in the drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiment of the utility model provided in the drawings is not intended to limit the scope of the utility model claimed for protection, but merely represents the selected embodiment of the utility model. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without making creative work belong to the scope of protection of the utility model.

[0022] It should be noted that similar numbers and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further defined and explained in the subsequent drawings. In the description of the utility model, it should be noted that the orientation or position relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inside", "outside", etc. is based on the orientation or position relationship shown in the drawings, or the orientation or position relationship in which the utility model product is usually placed when used, which is only for the convenience of describing the utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the utility model. In addition, the terms "first", "second", "third", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance. In addition, the terms "horizontal", "vertical", etc. do not mean that the components are absolutely horizontal or suspended, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly tilted. In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0023] like Figures 1 to 4 As shown, the forced air cooling structure of the motorcycle engine in this specific embodiment includes a cylinder block 1 and a cylinder head 2 fixedly connected to the front end of the cylinder block 1, the rear end of the cylinder head 2 and the front end of the cylinder block 1 are respectively provided with a dome and a piston hole 3 that can be closed to form a combustion chamber, the outer side surface of the cylinder block 1 is convexly formed with a cylinder sleeve 4 wound around the cylinder block, a cooling air duct 5 extending around the center line direction of the piston hole 3 is formed between the cylinder sleeve 4 and the cylinder block 1, the cylinder sleeve 4 is provided with an air duct inlet and an air duct outlet at the positions corresponding to the starting end and the end of the cooling air duct 5, respectively, the cylinder head 2 is fixedly connected with a fan 6, and the air outlet of the fan 6 is connected to the air duct inlet of the cooling air duct 5.

[0024] In this specific embodiment, a camshaft chamber 7 is provided at the front end of the cylinder head 2, and a camshaft 8 is provided in the camshaft chamber 7. Both ends of the camshaft 8 are rotatably connected to the cavity wall of the camshaft chamber 7. The fan 6 is correspondingly arranged at a position at one end of the camshaft 8 along its axial direction, and the end of the camshaft 8 corresponding to the side where the fan 6 is located passes out of the cylinder head 2 and extends into the fan 6 to be transmission-connected to the impeller of the fan 6.

[0025] In this specific embodiment, the cylinder block 1 and the cylinder head 2 are fixedly connected together by fixing bolts. The outer surface of the cylinder block 1 and the position located in the cooling air duct 5 are formed with a plurality of protrusions 9 at intervals along the extension direction of the cooling air duct 5. The protrusions 9 are respectively integrally formed with the cylinder block 1 and the cylinder liner 4. The cylinder liner 4 is provided with connecting holes that pass through the cylinder liner 4 and the protrusions 9 at positions corresponding to the protrusions 9. The fixing bolts pass through the connecting holes and are threadedly connected to the cylinder head 2.

[0026] In this specific implementation manner, the arc structure formed by the cooling air duct 5 extending around the center line direction of the piston hole 3 is a major arc structure.

[0027] In this specific embodiment, the front end of the cylinder body 1 is raised to form a boss, and the rear end of the cylinder head 2 is provided with an abutment surface parallel to the top surface of the boss, and a metal thermal conductive pad with the same shape as the top surface of the boss is provided between the boss and the abutment surface, and the boss and the abutment surface are respectively pressed against the side surfaces of the metal thermal conductive pad.

[0028] In this specific implementation, the fan 6 is a centrifugal fan.

[0029] In this specific implementation, a plurality of heat dissipation fins 10 are protruded and formed on the cylinder head 2 and the cylinder body 1 .

[0030] In this specific embodiment, two valve holes connected to the dome are formed on the cavity wall of the camshaft chamber 7, and an outlet flow channel 11 is provided on the side surface of the cylinder head 2 facing away from the fan 6 and between the dome and the camshaft chamber 7. The outlet flow channel 11 extends toward the side where the fan 6 is located and passes through the position between the two valve holes. An outlet hole connected to the outlet flow channel 11 is recessed at the position of the cylinder head 2 corresponding to the outlet end of the outlet flow channel 11, and a spark plug hole 12 connected to the dome is formed at the outlet hole. An end of the outlet flow channel 11 facing the side where the fan 6 is located extends toward the upper end or the lower end of the cylinder head 2 to form an intake flow channel 13, and the end of the intake flow channel 13 away from the outlet flow channel has an intake end that can intake air through the front of the cylinder head 2.

[0031] A motorcycle engine comprises the above-mentioned motorcycle engine forced air cooling structure.

[0032] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the utility model rather than to limit the technical solution. Ordinary technicians in this field should understand that those modifications or equivalent replacements of the technical solution of the utility model without departing from the purpose and scope of the technical solution of the utility model should be included in the scope of the claims of the utility model.

Claims

1. A forced air cooling structure for a motorcycle engine, comprising a cylinder block and a cylinder head fixedly connected to the front end of the cylinder block, wherein the rear end of the cylinder head and the front end of the cylinder block are respectively provided with a dome and a piston hole that can be closed to form a combustion chamber, characterized in that: A cylinder liner is formed on the outer side surface of the cylinder body, and a cooling air duct extending around the center line of the piston hole is formed between the cylinder liner and the cylinder body. An air duct inlet and an air duct outlet are respectively provided on the cylinder liner corresponding to the starting end and the end end of the cooling air duct. A fan is fixedly connected to the cylinder head, and the air outlet of the fan is connected to the air duct inlet of the cooling air duct.

2. The motorcycle engine forced air cooling structure according to claim 1, characterized in that: A camshaft chamber is provided at the front end of the cylinder head, and a camshaft is provided in the camshaft chamber. Both ends of the camshaft are rotatably connected to the cavity wall of the camshaft chamber. The fan is correspondingly arranged at a position at one end of the camshaft along its axial direction. The end of the camshaft corresponding to the side where the fan is located passes out of the cylinder head and extends into the fan to be transmission-connected with the impeller of the fan.

3. The motorcycle engine forced air cooling structure according to claim 1, characterized in that: The cylinder block and the cylinder head are fixedly connected together by fixing bolts, and a plurality of protrusions are formed on the outer surface of the cylinder block and located in the cooling air duct at intervals along the extension direction of the cooling air duct, and the protrusions are respectively integrally formed with the cylinder block and the cylinder liner, and connecting holes passing through the cylinder liner and the protrusions are provided at positions corresponding to the protrusions on the cylinder liner, and the fixing bolts pass through the connecting holes and are threadedly connected to the cylinder head.

4. The motorcycle engine forced air cooling structure according to claim 1, characterized in that: The arc structure formed by the cooling air duct extending around the center line direction of the piston hole is a superior arc structure.

5. The motorcycle engine forced air cooling structure according to claim 1, characterized in that: The front end of the cylinder body is raised to form a boss, and the rear end of the cylinder head is provided with an abutment surface parallel to the top surface of the boss. A metal heat-conducting pad with the same shape as the top surface of the boss is provided between the boss and the abutment surface, and the boss and the abutment surface are respectively pressed against the side surfaces of the metal heat-conducting pad.

6. The motorcycle engine forced air cooling structure according to claim 1, characterized in that: The fan is a centrifugal fan.

7. The motorcycle engine forced air cooling structure according to claim 1, characterized in that: A plurality of heat dissipation fins are protruded and formed on the cylinder head and the cylinder body respectively.

8. The motorcycle engine forced air cooling structure according to claim 2, characterized in that: The camshaft chamber has two valve holes formed on its wall which are connected to the dome. An outlet passage is provided on a side surface of the cylinder head which faces away from the fan and between the dome and the camshaft chamber. The outlet passage extends toward the fan side and passes through a position between the two valve holes. An outlet hole connected to the outlet passage is recessed at a position of the cylinder head corresponding to the outlet end of the outlet passage. A spark plug hole connected to the dome is formed at the outlet hole. An end of the outlet passage which faces the fan side extends toward the upper end or the lower end of the cylinder head to form an inlet passage. An end of the inlet passage which is away from the outlet passage has an inlet end which can intake air through the front of the cylinder head.

9. A motorcycle engine, characterized in that: The invention comprises the forced air cooling structure for a motorcycle engine as claimed in any one of claims 1 to 8.

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