JP3146545B2 - Unit swing engine swing case cooling structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a swing case cooling structure for a unit swing engine.

[0002]

2. Description of the Related Art A unit swing engine widely used for a scooter type vehicle and the like has a swing case connected to a crankcase of the engine, extending rearward, and supporting a rear wheel at a rear end portion. A belt transmission mechanism for shifting the output of the engine and transmitting the output to the rear wheels is built therein.

Since the belt transmission mechanism generates frictional heat during operation, the swing case has a cooling structure for introducing outside air for cooling.

In a conventional swing case cooling structure, a ventilation member such as a hose is connected to a swing case, and a free end of the ventilation member is connected to an air cleaner attached to a vehicle body. Outside air is sucked from the air cleaner to remove dust. After that, it passes through the ventilation member and enters the swing case to cool the belt speed change transmission mechanism.

[0005]

However, the conventional swing case cooling structure has a long ventilation path from the air intake to the inside of the swing case, requiring a large number of parts required for it, and increasing the cost. This requires a large space for arranging components and has a low degree of freedom in layout. Further, when the ventilation path is long, there is a problem that the ventilation resistance increases and the cooling effect in the swing case deteriorates.

Therefore, as disclosed in Japanese Utility Model Laid-Open Publication No. 59-195018, the outside air intake opening formed on the outer surface of the swing case is covered with a separate outside air introduction cover extending vertically, and this outside air introduction cover is provided. A short outside air introduction passage is formed inside the cover, one end of the outside air introduction passage is connected to the outside air suction port, an outside air intake is formed at the other end of the outside air introduction passage, and a filter element is provided in the middle of the outside air introduction passage. By providing the cooling device, there is a cooling device whose structure is simplified while improving the cooling performance.

However, in this cooling device, since the outside air introduction cover protrudes greatly from the upper surface of the swing case, an article storage room is provided above the unit swing engine as in a recent scooter type vehicle, and the swing case has In a vehicle body layout in which an engine air cleaner is installed on the upper part, the capacity of the article storage room and the air cleaner is sacrificed due to the upward projection of the outside air introduction cover, and the layout of the vehicle body also deteriorates.

Also, the number of parts is small because the outside air introduction cover is separate from the swing case, and a seal member such as a gasket or an O-ring needs to be interposed at the joint between the swing case and the outside air introduction cover. And it was not necessarily a simple structure. The seal member cannot be omitted because the joint between the swing case and the outside air introduction cover is exposed to the outside.

Further, in this cooling device, the outside air suction port and the filter element are positioned higher than the outside air suction port, so that the foreign matter such as moisture and dust once entering the outside air introduction passage is poorly discharged. For example, moisture blocked by the filter element may remain in the outside air introduction passage, enter into the swing case from the outside air suction port over time, or dust may accumulate on the upstream side of the filter element.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it has been made possible to shorten the length of the ventilation path from the air intake to the inside of the swing case, reduce the ventilation resistance, and reduce the cooling effect in the swing case. The layout can be improved by eliminating the risk of sacrifice of the air storage capacity of the article storage room and the engine of the scooter type vehicle, and the structure can be simplified by reducing the number of components. Further, it is an object of the present invention to provide a swing case cooling structure of a unit swing engine having a high discharge property of foreign matter that has entered a ventilation path.

[0011]

SUMMARY OF THE INVENTION To achieve the above object, a swing case cooling structure for a unit swing engine according to the present invention comprises introducing outside air into a swing case having a built-in belt shift transmission mechanism. In the swing case cooling structure of the unit swing engine that cools, a wind guide path extending substantially in the front-rear direction is integrally formed on the outer surface of the swing case cover that covers the outer surface of the swing case, and At the front end, a communication port communicating with the inside of the swing case is formed, and at the rear end of the air guide path, an air intake port that opens rearward to the outside is formed, and the communication port is positioned higher than the air intake port. An air filter is provided between the port and the air inlet, and the air filter is positioned lower than the communication port.

[0012]

When the swing case cooling structure of the unit swing engine is configured as described above, the length of the ventilation path from the air intake to the inside of the swing case is shortened, the ventilation resistance is reduced, and the cooling effect in the swing case is enhanced. . In addition, since the air guide path is integrated with the swing case cover and no seal member or the like is required, the number of components is reduced and the structure is simplified.

Further, since the air guide path does not protrude above the swing case, the capacity of the article storage room in the scooter type vehicle and the air cleaner of the engine is not sacrificed. Furthermore, since the communication port to the swing case is higher than the air intake port, the discharge property of foreign matter that has entered the air guide passage is increased, and since the air filter is lower than the communication port, the air filter is lower. There is no danger that foreign matter blocked by the filter will enter the swing case over time.

[0014]

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a left side view of a scooter type vehicle to which a swing case cooling structure for a unit swing engine according to the present invention is applied. In the scooter type vehicle 1, a unit swing engine 4 is pivotally supported at a lower center portion of a body frame 2 via a link 3 so as to be swingable around a horizontal support shaft 5, and a rear portion of the unit swing engine 4 and the body frame 2 The rear part is connected by a telescopic shock absorber 6.

The unit swing engine 4 has an engine 7 at the front. A swing case 8 extending rearward is integrally connected to a crankcase of the engine 7, and a rear wheel is attached to a rear end of the swing case 8. 9 is pivotally supported.

Inside the swing case 8, an engine 7 is provided.
A belt speed change transmission mechanism for shifting the output of the swing case 8 and transmitting the output to the rear wheel 9 is built in, and the swing case cover 11 is detachably provided so as to cover an opening on the outer side surface (here, left side) of the swing case 8. A swing case cooling structure according to the present invention is provided.

FIG. 2 is a left side view of the swing case cover 11, and FIG. 3 is a perspective view.

On the outer surface of the swing case cover 11,
A groove-shaped air duct 12 extending outward (left side) and extending substantially in the front-rear direction is integrally formed. This air duct 1
An air inlet 13 is formed at the rear end of the air passage 13 and opens rearward to the outside. The engine center 14 is the center of a crankshaft (not shown) of the engine 7. The crankshaft has a fan 15
Are provided integrally with the rotation. Also, the bottom surface 1 of the air guide channel 12
6 are provided with a plurality of drain holes 17.

FIG. 4 is an enlarged view of the air guide path 12, FIG. 5 is a sectional view taken along the line V--V in FIG. 4, and FIG. 6 is a perspective view of the air guide path 12 viewed from the back side of the swing case cover 11. It is.

A seal plate 18 is provided on the back side of the air duct 12.
Are fixed with screws 19, and the air guide path 12 is connected to the swing case 8
And a closed conduit. As shown in FIGS. 4 and 6, the seal plate 18 does not cover the portion where the air guide path 12 is arranged in the engine center 14, and thus the seal plate 18 has a communication port 21 through which the air guide path 12 communicates into the swing case 8. Becomes

The communication port 21 is positioned higher than the air inlet 13, and an air filter 22 is provided in the air guide path 12 between the communication port 21 and the air inlet 13. The air filter 22 is positioned immediately upstream (on the air intake 13 side) of the communication port 21 and lower than the communication port 21. For example, a plurality of the air filters 22 are provided upright in the air guide path 12 before and after the air filter 22. It is supported between the fins 23 and is prevented from being pulled out by the seal plate 18.

At the rear end of the swing case cover 11, an exhaust port 24 as shown in FIGS. 2 and 3 is opened downward.

Thus, when the scooter type vehicle 1 travels,
The fan 15 rotates together with the crankshaft of the engine 7, and a negative pressure is applied to the communication port 21 that connects the air guide path 12 to the inside of the swing case 8. For this reason, outside air flows into the air guide passage 12 from the air inlet 13, and this outside air is
After the dust has been removed and purified, the fluid flows into the swing case 8, cools the frictional heat of the belt transmission mechanism that operates in the swing case 8, and is discharged from the exhaust port 24.

When water enters the air duct 12 through the air inlet 13 during running on rainy weather or the like, the water exits through the drain hole 17, so that water does not enter the swing case 8. Absent.

According to the swing case cooling structure configured as described above, the ventilation path from the air inlet 13 to the inside of the swing case 8 (the air guide path 12) is extremely short, so that the ventilation resistance is small. Sufficient cooling air flows in for effective cooling.

Further, since it is not necessary to arrange the ventilation path components such as hoses and air cleaners on the vehicle body as in the prior art, the layout of the vehicle body is improved and the aesthetic appearance is improved. Does not protrude upward, the capacity of the article storage room (see FIG. 1) of the scooter type vehicle 1 and the capacity of an air cleaner (not shown) of the engine 7 is not sacrificed.

In addition, since the air guide path 12 is formed integrally with the swing case cover 11, a cover member forming the air guide path 12 can be prepared as a separate component, or the cover member and the swing case cover 11 can be provided separately. There is no need to interpose a seal member or the like at the joint, and no hose or air cleaner is required as described above, so the number of components of the entire cooling device is reduced, the structure is simplified, and the cost is reduced. Down can be planned. Since the seal plate 18 is installed inside the swing case cover 11, there is no need to interpose a seal member between the seal plate 18 and the swing case cover 11.

Further, the communication port 21 is provided above the air inlet 13 and the plurality of drain holes 17 are formed in the bottom surface 16 of the air guide path 12, so that the inside of the air guide path 12 is formed. Since the foreign matter such as moisture or dust that has entered is highly dischargeable, and the air filter 22 is provided below the communication port 21, the foreign matter blocked by the air filter 22 may enter the swing case 8 over time. No, swing case 8
The soundness of the belt speed change transmission mechanism operating in the inside can be kept good.

[0030]

As described above, the swing case cooling structure of the unit swing engine according to the present invention is a unit swing that cools the belt speed change transmission mechanism by introducing outside air into the swing case including the belt speed change transmission mechanism. In the cooling structure of the swing case of the engine, an air guide path extending substantially in the front-rear direction is integrally formed on the outer surface of the swing case cover that covers the outer surface of the swing case, and a front end of the swing case is formed at a front end of the air guide path. Forming an air inlet that opens rearward to the outside at the rear end of the air guide path, and positioning the communication port higher than the air inlet; and forming a communication port and an air inlet. An air filter is installed between the air filter and the air filter, and the air filter is positioned lower than the communication port.

According to this configuration, the length of the ventilation path from the air intake to the inside of the swing case is shortened to reduce the ventilation resistance, and the cooling effect in the swing case is enhanced.
The layout of the vehicle body can be enhanced without fear of sacrificing the capacity of the article storage room or the air cleaner of the engine in the scooter type vehicle. In addition, the number of components can be reduced to simplify the structure, and at the same time, the ability to discharge foreign substances that have entered the ventilation path can be improved.

[Brief description of the drawings]

FIG. 1 is a left side view of a scooter type vehicle to which a cooling structure for a unit swing engine according to the present invention is applied.

FIG. 2 is a left side view of the swing case cover.

FIG. 3 is a perspective view of a swing case cover.

FIG. 4 is an enlarged view of a wind guide path showing one embodiment of the present invention.

FIG. 5 is a sectional view taken along the line VV in FIG. 4;

FIG. 6 is a perspective view of the air guide path viewed from the back side of the swing case cover.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Scooter type vehicle 4 Unit swing engine 7 Engine 8 Swing case 11 Swing case cover 12 Air guideway 13 Air intake 18 Seal plate 21 Communication opening 22 Air filter 23 Fin

Claims (1)

(57) [Claims] In a swing case cooling structure of a unit swing engine for cooling the belt transmission mechanism by introducing outside air into a swing case having a built-in belt transmission mechanism, a swing covering an outer surface of the swing case. An air guide path (12) extending substantially in the front-rear direction is integrally formed on the outer surface of the case cover (11), and a communication port communicating with the front end of the air guide path (12) in the swing case (8). While forming (21), an air inlet (13) is formed at the rear end of the air guide path (12) so as to open backward to the outside,
The communication port (21) is positioned higher than the air intake (13), and an air filter (22) is installed between the communication port (21) and the air intake (13). ) Is positioned lower than the communication port (21).