JP2523743Y2 - Forced air-cooled engine cooling system for motorcycles - Google Patents

Description

[Detailed description of the invention] [Industrial application field] In this invention, a low-floor type step floor portion is provided in a lower curved portion of a body frame formed between front and rear wheels, and a forced air-cooled engine is provided behind the step floor portion. The present invention relates to a positioned step-through type motorcycle with improved engine cooling efficiency.

[Prior Art] Step-through type automatic 2 having the above structure
Wheel wheels are known. The fan of the forced air-cooled engine is surrounded by a fan cover provided on the side of the cylinder of the engine. Cooling air is sent to the cylinder. Examples of such a structure include Japanese Utility Model Laid-Open Nos. 57-29421 and 58-104726. Further, there is also known a device in which an opening is provided on the side of the front fender, and cooling air is guided to a rear air-cooled engine from a tunnel-shaped air passage provided below a step floor (JP-A-63-215471).

In the present application, the front, rear, left and right directions are based on the traveling direction.

[Problem to be Solved by the Invention] By the way, since the above fan cover is located behind the step floor, it is usual that the air intake is opened to the side of the vehicle body, so that it is difficult to use the traveling wind. It has become. Therefore, when increasing the fan cover, it is necessary to increase the air volume.
It is difficult to secure the air volume only from the side air intake, as in Nos. 57-29421 and 58-104726. For this reason, it is desired to improve the cooling efficiency by actively using the traveling wind.

Further, as in Japanese Patent Application Laid-Open No. 63-215471, when providing a wind guide path, it is necessary to provide the air intake in a portion where traveling wind gathers as much as possible. May be clogged by mud or the like jumped up by the front wheels. For this reason, Japanese Unexamined Patent Publication No.
In 215471, a part of the front end of the air guide path must be covered with an end plate, and as a result, the amount of air that can be introduced is reduced, and the clogging due to mud or the like cannot be reliably eliminated.

Accordingly, an object of the present invention is to provide a cooling device for a forced air-cooled engine that solves this problem.

[Means for Solving the Problems] In order to solve the above problems, in the step-through type motorcycle, the forced air-cooled engine cooling device of the present invention supports the step floor portion and guides the traveling wind backward. A wind guide member is provided in the front-rear direction of the vehicle body, and the wind guide member has a substantially U-shaped cross section opened downward, and a front end portion thereof covers a front wheel upper side and is connected to a step floor and is a front fender rearward of the front wheel and The step floor is opened inside the position near the connecting portion of the step floor, the rear end is directed to open near the air inlet of the fan cover, and the step floor covering above the air guide member is the air collecting portion of the fan cover. It is characterized by extending obliquely upward rearward to the vicinity of the entrance.

[Operation of the Invention] The traveling wind is guided by the wind guide member, flows out behind the step floor, enters the fan cover from the air inlet of the fan cover, and is blown by the fan to forcibly cool the engine.

At this time, the front end portion of the wind guide member opens above the front wheel and opens inside the position near the step floor connection portion of the front fender which covers the front wheel and is continuous with the step floor. Because the opening is directed to the mouth, a large amount of traveling wind can be taken in from near the front wheels behind the front fender where a lot of traveling wind gathers, and can be blown into the air intake of the fan cover. Improves the cooling efficiency.

Furthermore, since the baffle member has a substantially U-shaped cross section opened downward, even if mud or the like jumped up by the front wheel enters the baffle passage, it naturally falls and there is no danger of clogging. In addition, the rear end is directed to open near the air intake of the fan cover, and the step floor covering the upper side of the baffle member extends obliquely upward to the vicinity of the air intake of the fan cover. Therefore, a negative pressure is generated by the traveling wind flowing along the step floor, and it becomes difficult for the traveling wind taken into the air guide passage to escape from the open portion to the lower side due to the negative pressure, and the wind is efficiently guided. .

[Embodiment] An embodiment is shown in FIG. 1 to FIG. FIG. 1 is a partially cutaway side view of a step-through type motorcycle, FIG. 2 is a plan view of the step-through type motorcycle, and FIG. 3 is a rear view of the step-through type motorcycle (in the direction of arrow R in FIG. 1). FIG. 1 is a front wheel, 2 is a front fork, 3 is a handle, 4 is a seat, 5 is a seat post, 6 is a fuel tank, 7 is a vehicle body cover, 8 is a step floor formed on a part thereof, 9 is a power unit, and 10 is a power unit. The air cleaner 11 is a rear wheel. A concave portion 4a for gripping when the stand is operated is formed on the left and right of the bottom of the seat 4, and an article hanging portion 4b made of a gate-shaped wire is provided on the bottom surface.

As shown in FIGS. 2 and 3, a power unit 9 and an air cleaner 10 are arranged on the left side of the rear wheel 11, and a muffler 12 is arranged on the right side. Above the rear wheel 11 is a rear fender 13
Covered with.

As is clear from FIG. 1 and FIG. 4 from which the covers and a part of the rear side are omitted, one main frame 14 is provided at the front center of the vehicle body in the front-rear direction. The front of the main frame 14 is welded to the front fork side,
The rear portion extends obliquely downward to the rear of the front wheel 1, bends substantially horizontally, and forms a downward curved portion 15 that curves downward and forward of the rear wheel 11. To the rear end of the main frame 14 is connected a rear frame 16 which is branched into right and left branches and extends obliquely upward and rearward. The main frame 14 and the rear frame 16 constitute a body frame. A pair of air guide members 17 are provided on the left and right sides of the lower curved portion 15 to extend in the front-rear direction and support the step floor 8. These air guide members 17 are welded to the main frame 14 of the downward curved portion 15 via a cross member, and form a floor board for supporting the step floor 8. The wind guide member 17 is disposed so that the rear is slightly inclined upward, and its cross section has a channel shape shown in FIG. 5 which is a cross section taken along the line AA in FIG. It is reinforced to a high strength. Since the wind guide member 17 is open at both front and rear ends and below, the space 18
(FIG. 5) forms an air guide path for guiding the traveling wind to the rear of the step floor 8. The front end of the wind guide member 17 forms a part of the vehicle body cover 7 and covers above the front wheel 2 to cover the step floor 8.
The rear part 7b of the front fender 7a, which is continuous with the front fender, is open to the rear of the front wheel and inside the position near the connection with the step floor.

As shown in FIG. 4, a rear end 19 of the left air guide member 17 forms an air outlet, and a fan cover 20 provided on the front right side of the power unit 9 is located behind the air outlet. The opening is directed toward the vicinity of the air inlet 23 of the fan cover 20 (see FIGS. 8 and 9). The step floor 8 covering the wind guide member 17 extends with the rear side inclined upward in the front-rear direction of the vehicle body, and its rear end extends to the vicinity of the air inlet 23 of the fan cover 20. The wind guide member 17 is a fan cover 20
Is important, and in the case of the present embodiment, it may be provided only on the left side, and in this case, the right side may be a mere support member of the floor board, and may have no wind guiding structure.

FIG. 6 is a diagram showing the power unit 9 enlarged from the front, FIG. 7 is a diagram showing the left side shape of the power unit 9, FIG. 8 is a diagram showing the fan cover 20 from the side (in the direction of arrow S in FIG. 6),
FIG. 9 is a diagram showing a cross section taken along the line BB.

As is clear from FIG. 6, the fan cover 20 includes a lower portion 21 covering the right side of the crankcase 9a and an upper portion 22 covering the right side of the cylinder 9b. A louver-shaped air inlet 23 is formed at the center of the lower portion 21 (FIGS. 8 and 9).
Figure). The periphery of the air intake 23 is surrounded by an annular wall 24.
The annular wall 24 protrudes sideways, and the edge of the
An air inlet 25 cut out in a substantially V-shape is formed in a portion facing the rear end 19. A known fan 26 is housed in the fan cover 20.

As shown in FIG. 4, the upper portion 22 covers the cylinder 9b together with the shroud 27, and an air outlet 28 formed by projecting a part of the shroud 27 rearward is formed at a rear portion where the upper portion 22 and the shroud 27 are joined. ing. The shroud 27 has a plug hole 29 formed in the upper part, through which a spark plug 30 can be inserted and removed. On the rear side, a positioning projection 31 that projects upward is integrally formed.

Hereinafter, the detailed structure of each part in the motorcycle of the present embodiment will be further described.

The power unit 9 includes a forced air-cooled engine and a belt transmission. As shown in FIG. 1, a front portion of the power unit 9 is swingably supported by a stay 32 welded to a rear end of the lower curved portion 15. 33 is an exhaust pipe, 34 is a vaporizer, 35 is a connecting tube, and 36 is a rear cushion. Further, a stand bracket 37 is provided at the rear of the downward curved portion 15 to extend obliquely downward to the rear, and a main stand 38 is supported so as to be able to move up and down. A stopper rubber 39 is attached to the main stand 38. When the main stand 38 is raised, it comes into contact with the lower side of the muffler 12 and is buffered at that time.
If a member similar to the stopper rubber 39 is attached to a bracket 12a for supporting the muffler 12, for example, on the contact partner side, the shock at the time of contact with the main stand is further reduced.

As shown in FIG. 4, reference numeral 40 denotes a transmission case integrally extending rearward from the left case of the crankcase 9a, 41 denotes a transmission cover, and 42 denotes a rear cover. Also, the transmission case 40
Bosses 43 and 44 are provided at the upper joint of the transmission cover 41 and bosses 45 to 47 are provided at the upper joint of the transmission case 40, the transmission cover 41, and the rear cover 42. . Further, a cushion mounting boss 48 is provided at an upper portion of the transmission case 40 at an intermediate portion of these bosses, and bosses 49 and 50 for fender mounting are respectively provided at a joint portion of the transmission case 40 and the rear end upper portion of the rear cover 42. Is provided.

As shown in FIG. 7, the boss 44 (43) is
Are fastened together with bolts 52 together with stays 51 extending downward and forward. Boss 47 (46, 45) is an air cleaner
It is fastened together with a bolt 54 together with a stay 53 projecting rearward and downward from the lower part of 10. Further, a mounting arm 55 extending downward from the rear fender 13 is fastened to the boss 50 (49) together with a bolt 56. FIG. 1 shows a state in which the air cleaner 10 and the rear fender 13 are attached. Therefore, the transmission cover 41 and the like can be fastened together with the attachment of the air cleaner 10 and the rear fender 13, so that the number of assembling steps is reduced.

Reference numeral 57 in FIGS. 1, 3, and 7 denotes a breather tube, which communicates with the inside of the air cleaner 10 from the transmission room.

FIG. 10 is a diagram showing a planar shape of the rear fender 13 associated with the shroud 27 and the air cleaner 10, and a front portion of the rear fender 13 overlaps a rear portion of an upper surface of the shroud 27, and the overlapping portion includes a positioning protrusion 31 of the shroud 27. An engaging notch 58 is formed. FIG. 11 is an enlarged sectional view taken along the line CC of FIG. 10 showing the engaged state. In this way, when the rear fender 13 is mounted on the power unit 9 side, first, the positioning can be performed by engaging the notch 58 with the positioning projection 31, so that the mounting operation is facilitated.

The upper part of the mounting arm 55 of the rear fender 13 forms an inclined wall 59 that changes to a tapered shape in a plan view, and a tongue piece 60 formed along the inclined wall 59 extends integrally from the inside of the air cleaner 10. Have been. Further, a cover portion 61 that covers the outer surface of the connecting tube 35 extending from the front portion of the air cleaner 10 is integrally formed to extend forward from the outside of the air cleaner 10 to prevent excessive cooling of the intake air.

Next, the operation of the present embodiment will be described. As shown in FIG. 1, the traveling wind enters the space 18 forming the air guide path from the front of the wind guide member 17 below the step floor 8, passes through the space 18, and flows out from the rear end 19 thereof. As shown in the figure, the air flows into the fan cover 20 from an air inlet 25 provided in the lower front part of the fan cover 20 and, together with the air from the air inlet 23 as shown in FIGS. Then, the inside of the fan cover 20 is blown by the fan 26 to the cylinder 9b (FIG. 6). Thereafter, as shown in FIG. 4, the internal cylinder is cooled while circulating in the shroud 27, and the air flows out from the air outlet 28 to the outside. Therefore, a large amount of traveling air can be taken in from near the rear of the front wheel, which is the rear part 7b of the front fender 7a where a large amount of traveling wind gathers, and can be blown to the air intake 23 of the fan cover 20, so that the air from the side air intake 23 In addition, since the traveling wind can be positively used, the amount of cooling air is increased, and the cooling efficiency of the engine is improved. Therefore, since the traveling wind is originally blocked by the front step floor 8, the forced cooling using the traveling wind can be performed in spite of the step-through type in which the traveling wind is not so much expected for cooling the engine. Therefore, it is easy to increase the size of the fan cover 20 to increase the capacity.

Also, by forming the air guide member 17 into a channel shape,
This is advantageous because both the strength improvement as the strength member for the step floor 8 and the formation of the air guide path can be realized at the same time.

Moreover, since the baffle member 17 has a substantially U-shaped cross section opened downward, even if mud or the like jumped up by the front wheel 1 enters the space 18 of the baffle passage 17, it naturally falls and becomes clogged. There is no danger of doing so. In addition, since the step floor 8 is provided with the rear side inclined upward in the front-rear direction of the vehicle body and the rear end thereof is extended to the vicinity of the air intake 23 of the fan cover 20,
The traveling wind flowing along the step floor 8 generates a negative pressure, and the traveling pressure taken into the air guide path 17 is less likely to escape from the open portion to the lower side by the negative pressure, thereby making the guiding more efficient. be able to.

The present invention is not limited to the above-described embodiment. For example, the air inlet 25 may be a hole-shaped opening formed in the front part of the fan cover 20.

[Effects of the Invention] In the present invention, a wind guide member for supporting the step floor is provided in the front-rear direction, a fan cover is arranged behind the wind guide member, and the front end of the wind guide member covers the front wheel and is continuous with the step floor. Open the front fender behind the front wheel and inside the position near the step floor connection, and
Since the air intake of the fan cover is oriented and opened, a large amount of traveling air can be taken in from the vicinity of the front wheel rear of the front fender where a lot of traveling wind gathers and blown to the air intake of the fan cover, and the traveling wind is positively increased. Utilization can improve the cooling efficiency.

Furthermore, since the baffle member has a substantially U-shaped cross section opened downward, even if mud or the like jumped up by the front wheel enters the baffle passage, it naturally falls and there is no danger of clogging. Moreover, since the wind guide member is provided with the rear side inclined upward in the front-rear direction of the vehicle body, a negative pressure is generated by the traveling wind flowing along the wind guide path, and the negative pressure is taken into the wind guide path by the negative pressure. It is difficult for the traveling wind to escape from the opening to the lower side, and the wind can be guided more efficiently.

[Brief description of the drawings]

1 to 11 show an embodiment, FIG. 1 is a partially cutaway side view of a motorcycle, FIG. 2 is a plan view thereof, FIG. 3 is a rear view thereof, and FIG. FIG. 5 is an enlarged cross-sectional view taken along line AA of FIG. 4, FIG. 6 is an enlarged view showing the power unit from the front, FIG. 7 is a left side view thereof,
FIG. 8 is an external side view of the fan cover, and FIG.
FIG. 10 is a cross-sectional view taken along a line B-B, FIG. 10 is a plan view of a main part, and FIG. (Explanation of reference numerals) 1 ... front wheel, 8 ... step floor, 9 ... power unit, 9a ... crankcase, 9b ... cylinder, 11 ...
Rear wheel, 14: Main frame that constitutes the front part of the vehicle body frame, 15: Downward curved portion, 17: Wind guide member, 19: Rear end that forms an air outlet, 20: Fan cover, 25 ... ... air inlet, 26 ... fan.

Claims (1)

(57) [Scope of request for utility model registration] 1. A step floor portion supported by a downward curved portion of a body frame formed between front and rear wheels, an air-cooled engine disposed behind the step floor portion and supported by the body frame, and A motorcycle provided with a cooling fan and a fan cover for covering the cooling fan, wherein a wind guiding member for supporting the step floor portion and guiding the traveling wind backward is provided in the front-rear direction of the vehicle body; The wind member has a substantially U-shaped cross section that is open downward, and its front end is open to the rear of the front wheel and inside the position near the step floor connection portion of the front fender that covers the front wheel and is continuous with the step floor. The end is directed to open near the air intake of the fan cover, and the step floor covering above the air guide member is located near the air intake of the fan cover. In forced air-cooled engine cooling system of a motorcycle, characterized in that it extends obliquely upward to the rear.