JPH10299483A - Forced air-cooling device for muffler of motorcycle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a forced air-cooling device for muffler of a motorcycle capable of sufficiently improving cooling efficiency for a heat guard and reducing a cost. SOLUTION: In a forced air-cooling device for muffler of a motorcycle constituted such that a muffler 2 incorporating a catalyst 1 is cooled by utilizing cooling air to forcibly cool an engine E, a heat guard 3 to cover the periphery of the muffler 2 is arranged so as to be overlapped with at least a part of a catalyst 1 and a part of cooling air is blown in a space between the heat guard 3 and the outer wall surface of the muffler 2. The heat guard 3 is formed integrally with a foot rest bracket 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a muffler forced air cooling system for a motorcycle having a catalyst in the muffler.

[0002]

2. Description of the Related Art In a motorcycle having a catalyst inside a muffler, the muffler becomes extremely hot due to the reaction of the catalyst. In particular, when there is a catalyst in the muffler immediately below the footrest, the heat damage is particularly problematic.
In this case, a heat guard (muffler cover) is screwed to the muffler. However, even if such a heat guard is attached, a sufficient heat shielding effect cannot be obtained because the heat of the muffler is immediately transmitted to the heat guard.

[0003] For this reason, there is a configuration in which cooling air for forcibly cooling the engine is supplied between a muffler and a heat guard.

[0004]

However, even in the case of utilizing the cooling air as described above, there is a problem that the cooling efficiency for the heat guard is not sufficient and the cost is high.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and has as its object to improve the efficiency of cooling a heat guard and to reduce the cost. Is to provide.

[0006]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention relates to a muffler for a motorcycle constructed to cool a muffler containing a catalyst by using cooling air for forcibly cooling an engine. In the air cooling device, so as to overlap at least a part of the catalyst,
A heat guard that covers the periphery of the muffler is provided, and a part of the cooling air is blown between the heat guard and the outer wall surface of the muffler, and the heat guard is formed integrally with a footrest bracket. Features.

[0007] In the invention configured as described above, the heat guard can be cooled by the cooling air flowing between the heat guard and the outer wall surface of the muffler. Moreover, since the heat guard is formed integrally with the footrest bracket, and the heat guard does not contact the muffler, the heat transmitted from the muffler to the heat guard can be sufficiently suppressed. Therefore, the cooling efficiency for the heat guard can be improved.

Further, since the heat guard is formed integrally with the footrest bracket, compared with the conventional case where a separate heat guard is screwed to the muffler,
The number of parts and cost can be reduced.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. 1 to 8 show a first embodiment, and FIG. 9 shows a second embodiment.

First, a first embodiment will be described with reference to FIGS. As shown in FIGS. 1 to 8, the muffler forced air cooling device for a motorcycle shown in this embodiment uses cooling air for forcibly cooling the engine E of the motorcycle,
In a configuration in which a muffler 2 containing a catalyst pipe (catalyst) 1 is cooled, a heat guard 3 that covers an outer wall surface of the muffler 2 is provided so as to overlap a part of the catalyst pipe 1. A part of the cooling air is blown between the guard 3 and the outer wall surface of the muffler 2, and the heat guard 3 is attached to the footrest bracket 4.
It is characterized in that it is integrally formed.

As shown in FIGS. 7 and 8, the engine E includes a cooling fan E1 connected to a crankshaft (not shown).
And a cover E3 for guiding the cooling air obtained by the cooling fan E1 to the cylinder portion E2 of the engine E.

As shown in FIG. 3, a cooling air outlet E3a is provided below the cover E3. And
An air guide tube 5 is provided to connect the outlet E3a and the inside of the heat guard 3. One end of the air guide tube 5 is connected to the outlet E3a, and the other end is guided inside the front end side of the heat guard 3 as shown in FIG.

The heat guard 3 is located below the footrest bracket 4, extends in the front-rear direction along the longitudinal direction of the muffler 2, and has an arc shape in the left-right direction along the upper surface of the muffler 2. Is formed. FIG. 5 shows one end of the heat guard 3 in the left-right direction.
As shown in FIG. 1, a side wall 3a bent to approach the outer wall surface of the muffler 2 is provided. The muffler 2 is provided with an upright wall 2 a so as to be close to the footrest bracket 4. Therefore, the air guide tube 5
Cooling air supplied from the heat guard 3, muffler 2
Through the flow path surrounded by the outer wall surface and the vertical wall 2a. In addition, instead of the standing wall 2a,
As shown in FIG. 6, a side wall 3 b approaching the outer wall surface of the muffler 2 may be provided at the other end of the heat guard 3.

As shown in FIG. 6, the footrest bracket 4 supports the footrest 6, and is fixed to the frame 7 with screws.

In the muffler forced air cooling device for a motorcycle constructed as described above, the cooling air obtained by the cooling fan E1 is directed upward to cool the cylinder portion E2, and a part of the cooling air is cooled by the air guide tube 5. As a result, it is sprayed on the inner surface of the heat guard 3. The blowing cooling air
It passes between the heat guard 3 and the muffler 2 and is discharged from the rear end of the heat guard 3.

Since the cooling air from the cooling fan E1 is used, the heat guard 3 and the muffler 2 can be reliably cooled even in an idling state where there is no running wind. Moreover, since the heat guard 3 and the muffler 2 are not in contact with each other, the heat shielding effect on the heat guard 3 is high. That is, the heat transmitted from the muffler 2 to the heat guard 3 can be sufficiently suppressed, and the cooling efficiency for the heat guard 3 can be sufficiently increased. Moreover, since the cooling efficiency is high, the distance between the muffler 2 and the heat guard 3 can be reduced. That is, compactness can be achieved.

Further, since the heat guard 3 is formed integrally with the footrest bracket 4, the number of parts and the cost can be reduced as compared with a conventional case where a separate heat guard is screwed to a muffler. Can be.

Next, a second embodiment of the present invention will be described with reference to FIG. However, the same components as those of the first embodiment are denoted by the same reference numerals, and description thereof will be omitted. The second embodiment is different from the first embodiment in that the front part of the heat guard 2 is inclined so as to be higher toward the front.

That is, the distance W1 between the inner surface of the front edge of the heat guard 3 and the outer wall surface of the muffler 2 is determined by the distance between the inner surface of the heat guard 3 and the outer wall surface of the muffler 2 where the air guide tube 5 is provided. It is configured to be larger than W2.

In the muffler forced air cooling system for a motorcycle constructed as described above, the flow velocity inside the heat guard 3 can be increased by using the ram pressure generated by the traveling wind F, so that the cooling efficiency is further improved. Can be done.

In each of the above embodiments, the cooling air passes through the air guide tube 5 as it is. However, a variable valve is provided in the air guide tube 5 so that the temperature of the muffler 2 and the heat guard 3 can be changed. Alternatively, the amount of air supplied to the heat guard 3 may be adjusted. Further, the heat guard 3 may be configured to be integrated with the footrest bracket 4 by fixing the heat guard 3 to the frame 7 by using the screw with the footrest bracket 4. Further, the heat guard 3 may be provided so as to cover the entire upper part of the catalyst pipe 1.

[0022]

According to the present invention, the heat guard can be cooled by the cooling air flowing between the heat guard and the outer wall surface of the muffler. Moreover, since the heat guard is formed integrally with the footrest bracket, and the heat guard does not contact the muffler, the heat transmitted from the muffler to the heat guard can be sufficiently suppressed. Therefore, the cooling efficiency for the heat guard can be improved.

Further, since the heat guard is formed integrally with the footrest bracket, compared with the conventional case where a separate heat guard is screwed to the muffler,
The number of parts and cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a side view showing a muffler forced air cooling device for a motorcycle shown as a first embodiment of the present invention.

FIG. 2 is an enlarged side view of a muffler forced air cooling device of the motorcycle.

FIG. 3 is a side view showing the internal structure of the muffler forced air cooling device of the motorcycle.

FIG. 4 is a diagram showing a muffler forced air cooling device of the motorcycle, and is a cross-sectional view taken along line AA of FIG. 2;

5 is a diagram showing a muffler forced air cooling device of the motorcycle, and is a cross-sectional view taken along line BB of FIG. 2;

6 is a diagram showing a muffler forced air cooling device of the motorcycle, and is a cross-sectional view taken along line CC of FIG. 3;

FIG. 7 is an exploded perspective view showing an engine in the muffler forced air cooling device of the motorcycle.

FIG. 8 is an exploded perspective view showing the engine in the muffler forced air cooling device of the motorcycle from the other side.

FIG. 9 is a side view showing a muffler forced air cooling device for a motorcycle shown as a second embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Catalyst (catalyst pipe) 2 Muffler 3 Heat guard 4 Footrest bracket E Engine

Claims (1)

[Claims] 1. A motorcycle muffler forced air cooling system configured to cool a muffler containing a catalyst by using cooling air for forced air cooling of an engine, wherein at least a part of the catalyst is overlapped. A heat guard is provided to cover the periphery of the muffler, and a part of the cooling air is blown between the heat guard and the outer wall surface of the muffler, and the heat guard is formed integrally with the footrest bracket. A muffler forced air cooling device for a motorcycle, characterized in that: