WO2003038249A1

WO2003038249A1 - Internal combustion engine for motorcycle

Info

Publication number: WO2003038249A1
Application number: PCT/JP2002/009423
Authority: WO
Inventors: Yoshihiro Funayama; Mamoru Otsubo; Yoshinobu Sawamura; Toshiharu Akutsu
Original assignee: Honda Giken Kogyo Kabushiki Kaisha
Priority date: 2001-10-31
Filing date: 2002-09-13
Publication date: 2003-05-08
Also published as: CN1185411C; BR0206227A; JP3632848B2; MY129190A; EP1441114B1; CN1423043A; AR037163A1; ES2414863T3; EP1441114A1; BR0206227B1; KR20040044391A; EP1441114A4; JP2003138936A

Abstract

An internal combustion engine for a motor cycle, wherein the side face of a cylinder (10) is covered by leg shields (15) supported on a front frame (2) tilted from the upper part to the rear lower side of the motor cycle with the axis (C) of the cylinder (10) generally positioned horizontal and suspended across the front frame (2), first cooling fins (10a) and (11a) formed parallel with the axis (C) of the cylinder (10) are formed on the upper and lower surfaces of either or both of the cylinder (10) and a cylinder head (11), and second cooling fins (10b) and (11b) are formed on the right and left side surfaces of either or both of the cylinder (10) and the cylinder head (11) in the direction orthogonal to the axis (C) of the cylinder (10), whereby running wind can be passed through downward by the vertical second cooling fins (10b) and (11b) at the bottom part of a space formed of the internal combustion engine (8), the front frame (2), and the leg shields (15) suspended on the right and left sides of the front frame (2).

Description

Internal combustion engine technology for motorcycles

The present invention relates to an internal combustion engine for a motorcycle provided with a cooling fin. Background technology

As shown in Fig. 5, the internal combustion engine 01 of the small motorcycle is supported on a front frame 02 inclined downward from the top of the front fork to the rear of the motorcycle with the axis C of the cylinder being substantially horizontal. There is. Internal combustion engine 01 is mainly crankcase

It consists of 04, cylinder 05, and cylinder head 06. Of these, cylinder

The side surfaces of the 05 and the cylinder head 06 are covered with a redder shield 03 having a shape shown in FIG. 6 hanging down over the front frame 02.

In the case of the small motorcycle as described above, the space formed by the internal combustion engine 01, the front frame 02 and the red shield 03 suspended to the left and right is tapered, and Various types of equipment 07 are installed between the crankcase 04 of the part and the front frame 02. If it is possible to secure a space large enough to allow the wind to blow through easily in this part, as shown in Figure 5, the upper, lower, left and right surfaces of the cylinder 05, and the upper, lower, left and right surfaces of the cylinder head 06. The cooling fins 05 f and 06 f provided on the both are formed in a direction parallel to the cylinder axis C, and the traveling wind W passes between the cooling fins 05 f and 06 f in the cylinder axial direction to cool the internal combustion engine 01 Can be effective.

However, as the internal combustion engine 01 becomes larger, the crankcase 04 becomes larger accordingly, the equipment 07 disposed between the crankcase 04 and the front frame 02 becomes larger, and the number of equipment further increases. Even in this case, the width between the two drooping lower parts of the reservoir shield 03 can not be expanded due to the operability of operation, so the internal combustion engine 01, the front frame 02, and the regula Composed by In the innermost part of the space, it may not be possible to secure a space large enough to allow the wind to blow through easily. In this case, the traveling wind blown there loses a place to move to the rear of the vehicle in the above-mentioned space, and flows out with the cylinder 05 and the cylinder head 06 down the left and right sides.

In the above case, if the left and right sides of the cylinder 05 and the cylinder head 06 are provided with cooling fins 05 ί, 06 f parallel to the cylinder axis C as shown in FIG. It is not preferable because it obstructs the flow of air and impairs the effect of internal combustion engine cooling. According to the present invention, it is not possible to provide a space of a size that allows the wind to easily blow through at the deepest part of the space formed by the internal combustion engine, the front frame, and leg shoulders suspended to the left and right. An object of the present invention is to provide an internal combustion engine for a motorcycle having a cooling fin effective for cooling the internal combustion engine. Disclosure of invention

In order to achieve the above object, an internal combustion engine for a motorcycle according to the present invention has a front frame which is substantially horizontal from the top of a front fork of a two-wheeled motor vehicle to a front frame inclined downward to the rear of the two-wheeled motor vehicle. In a motorcycle internal combustion engine in which the side surface of the cylinder is covered with a cylinder supported by the front frame and suspended on a front frame, at least one of the cylinder and the head of the cylinder is provided with the cylinder A first cooling fin formed parallel to the axis, and a second cooling fin formed in a direction perpendicular or substantially perpendicular to the axis of the cylinder on at least one of the left and right sides of the cylinder and the cylinder head It is characterized by having

According to the above configuration, the traveling air flowing into the top surface of the cylinder head of the internal combustion engine sandwiched between the redder shields is divided substantially up and down parallel to the cylinder head provided on the cylinder head and the upper and lower surfaces of the cylinder. The traveling wind flowing into the space formed by the internal combustion engine, the front frame, and the radar shield suspended to the left and right flows through the space between the first cooling fins. In the stopped state, when there is no space large enough for the wind to blow through easily, the vehicle goes to the rear It loses its place and splits on both sides of the cylinder head and cylinder, and flows downward between the second cooling fins in the direction perpendicular to the cylinder axis provided on the left and right sides of the cylinder.

As described above, in the internal combustion engine for a motorcycle according to the present invention, since the cooling fins having a shape extending in the direction of the air flow are provided according to the arrangement of the internal combustion engine and devices, the cooling effect of the internal combustion engine is enhanced. The oil temperature can be lowered to improve the durability of the internal combustion engine.

Preferably, the first cooling fin is formed in a straight line continuously in the front-rear direction of the motorcycle. In addition, it is desirable that the second cooling fins be formed linearly in a substantially vertical direction. Brief description of the drawings

FIG. 1 is a side view of a small-sized motorcycle on which an internal combustion engine according to an embodiment of the present invention is mounted.

FIG. 2 is a perspective view of the internal combustion engine of the above embodiment.

FIG. 3 is an external perspective view of the cylinder of the above embodiment.

FIG. 4 a is an operation explanatory view of the embodiment, and is a side view of an internal combustion engine portion.

FIG. 4 b is a cross-sectional view taken along line B-B of FIG. 4 a.

FIG. 5 is a perspective view of a conventional small-sized motorcycle internal combustion engine.

FIG. 6 is a perspective view of a leg shield used in the above-mentioned motorcycle. BEST MODE FOR CARRYING OUT THE INVENTION

FIG. 1 is a side view of a small-sized motorcycle 1 equipped with an internal combustion engine according to an embodiment of the present invention. The main part of the body frame connects the front frame 2 that descends rearward from the top of the front fork 5, and the rear frame 3 that is connected to the rear of the front frame and is curved obliquely upward toward the rear. Is configured. A head pipe 4 connected to the front of the front frame 2 rotatably supports an upper portion of the front fork 5. Front wheel on the lower part of the Freon fork 5 6 is pivotally supported, and a handle 7 is provided at the top of the front fork that extends left and right.

At the lower part of the front frame 2, an internal combustion engine 8 is supported with the axis C of the cylinder substantially horizontal. The internal combustion engine 8 is provided with a crankcase 9, a cylinder 10 and a cylinder head 11. A chain case 12 extends rearward from the crankcase 9 and a rear wheel 13 is pivotally supported at its rear end. The rear part of the chain case 12 is connected to the rear part of the rear frame 3 via a shock absorber 14. The cylinder 10 of the internal combustion engine 8 and the side surface of the cylinder head 11 are covered with a redder shield 15 hanging down over the front frame 2. In addition, Lyaframe 3 is covered by Lyacapa 16 and a sheet 17 is provided at the top of Lyacapa 1 16.

FIG. 2 is a perspective view of the internal combustion engine 8 of the above embodiment. In FIG. 2, the internal combustion engine is supported at the lower part of the front frame 2 with the axis C of the cylinder substantially horizontal in the longitudinal direction of the vehicle. The right side of the figure is the forward direction of travel. The internal combustion engine 8 is composed of a crankcase 9, a cylinder 10, a cylinder head 11, and various devices 18 mainly mounted on the top of the crankcase 9. Cooling fins are formed on the outer surfaces of the cylinder 10 and the cylinder head 11 that become hot.

In the cylinder 10 of the present embodiment, first cooling fins 10a parallel to the cylinder axis C (that is, in the front-rear direction) are formed on the upper and lower surfaces thereof, and right and left side surfaces thereof are orthogonal to the cylinder axis A second cooling fin 10b is formed in the direction or in the direction substantially orthogonal (that is, in the substantially vertical direction). Further, the same applies to the cylinder head 11 of the present embodiment, and the first cooling fin 11a parallel to the cylinder axis C is formed on the upper and lower surfaces thereof, and the right and left side surfaces are orthogonal to the cylinder axis. A second cooling fin lib is formed in the direction or almost orthogonal direction. The first and second cooling fins are formed in a straight line continuously.

FIG. 3 is an external perspective view of the cylinder 10 of the above embodiment. The alternate long and short dash line C indicates the cylinder axis, and the arrows on the periphery of the figure indicate the upward U, lower D, left L, and right R directions when the cylinder 10 is mounted on a motorcycle, respectively. There is. The top, bottom, left side and right side of the cylinder in FIG. 3 are defined corresponding to the directions of the arrows. Siri The bottom axis C is a rotational symmetry axis of the cylinder bore 10c. Next to the cylinder hole 10c, there is provided a chain chamber 10d for passing a cam chain for driving the overhead cam shaft. In addition, a tensioner lifter mounting hole 10 e is provided which communicates the chain chamber 10 d with the upper surface of the cylinder 10. The tensioner lifter is a device for applying tension to the cam chain. At the periphery of the cylinder 10, there is provided a connecting port through hole 10f for connecting the crank case 9, the cylinder 10 and the cylinder head 11.

As described above, the first cooling fin 10a parallel to the cylinder axis C is provided on the upper surface and the lower surface of the cylinder 10, and the left side and the side surface are orthogonal or substantially orthogonal to the cylinder axis C. A second cooling fin 10b is provided which extends. In any of these cases, when the cylinder 10 is made of aluminum, it is integrally formed with the cylinder. The first cooling fins 11a and the second cooling fins l i b of the cylinder head 11 are also integrally formed when the cylinder head 11 is made of an aluminum material.

Fig. 4a and Fig. 4b are operation explanatory views of the above embodiment, Fig. 4a is a side view of the internal combustion engine, and Fig. 4b is a cross-sectional view taken along line B-B of Fig. 4a. An internal combustion engine 8 is suspended on the front frame 2. The main members of the internal combustion engine 8 within the illustrated range are the crank case 9, the cylinder 10, the cylinder head 11, and the devices 18 disposed between the front frame 2 and the crank case 9. In order to protect the driver's legs from the high temperature on both sides of the internal combustion engine 8, the front shield 2 is suspended from the radar shield 15. In Fig. 4a, the front side of the redder shield 15 is removed. The space between the front frame 2, the lid shield 15, and the crankcase 9 is occupied by the above-mentioned devices 18 and there is almost no gap through which air flows. Of the traveling air flowing from the front of the vehicle into the space between the front frame 2 and the radar shield 15, the traveling air W a flowing into the top of the cylinder head 11 of the internal combustion engine is roughly divided into upper and lower parts. It flows between the respective first cooling fins 11 a and 10 a parallel to the cylinder axis provided on the upper and lower surfaces of the The traveling wind W b flowing into the space between the front frame 2 and the cylinder head 11 is at the back As the deepest part is almost closed as it invades toward the vehicle, it loses a place to go to the rear of the vehicle, and splits on both sides, orthogonal to the cylinder axis provided on the left and right sides of cylinder head 11 and cylinder 10 It flows downward through between the second cooling fins 11 b and 10 b in the substantially orthogonal direction. The air which has flowed between the first cooling fins lia, 10a parallel to the cylinder axis also flows downwards finally through the left and right side surfaces of the cylinder 10.

As described above, since the second cooling fins lib and 10b in the direction orthogonal to the cylinder axis C are formed on the left and right side surfaces of the cylinder head 11 and the cylinder 10, the vehicle head space is The air, which has lost its place, also flows downward through the space between the second cooling fins lib, 10b formed in the cylinder head 11 and the cylinder 10. Therefore, the traveling wind can effectively cool the internal combustion engine 8 to reduce the temperature of the lubricating oil, and the durability of the internal combustion engine itself can be improved.

In the embodiment described above, the second cooling fins lib, 10b are formed in a linear shape, but may be formed in a partially curved shape to achieve a smooth flow of air.

Claims

The scope of the claims

1. The axis (C) of the cylinder is supported substantially horizontally on the front frame (2) inclined from the top of the front fork (5) of the motorcycle to the lower rear of the motorcycle, and the front frame ( 2) In a motorcycle internal combustion engine in which the side surface of the cylinder (10) is covered with a recess (15) hanging down across at least one of the upper and lower surfaces of the cylinder (10) and the cylinder head (11), A first cooling fin (10a, 11a) formed parallel to the axis (C) of the cylinder (10), and at least one of the left and right sides of the cylinder (10) and the cylinder head (11) (C) an interior of a motorcycle comprising a second cooling fin (10b, lib) formed in a direction orthogonal to or substantially orthogonal to (C);

2. The internal combustion engine for a motorcycle according to claim 1, wherein the first cooling fin (10a, 11a) is continuously formed in a straight line in the front-rear direction of the motorcycle.

3. The internal combustion engine for a motorcycle according to claim 1 or 2, wherein the second cooling fin (10b, lib) is formed in a substantially straight line in the substantially vertical direction.