JPH0141857Y2 - - Google Patents

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a muffler cooling device that cools a muffler body by supplying cooling air into a muffler cover.

<Prior Art> Conventionally, there is a device of this type as shown in FIG. 4, for example.

In the air-cooled engine 1, an exhaust inlet 22 is provided at the top of a vertically long muffler body 9, a ventilation space 10 is provided around the outer circumference of the muffler body 9, and a muffler cover 11 is provided to cover the muffler body 9, and a cooling air inlet is provided at the top of the muffler cover 11. 13 and a muffler cover 11
Open a cooling air outlet 23 in a part of the fan 28.
The cooling air generated by the cooling air is supplied to the ventilation space 10 from the cooling air inlet 13 and is discharged to the outside from the cooling air outlet 23. The cooling air forced from the fan 28 to the cooling air outlet 13 descends while cooling the muffler body 9, and is discharged to the outside from the cooling air outlet 23 provided at the lower part of the muffler cover 11. It's summery.

<Problems to be solved by the invention> In such a device, the cooling air that descends through the ventilation space 10 while cooling the muffler body 9 gradually warms up, becomes lighter, and tends to rise. There is a problem in that the back pressure of the supplied cooling air reduces the amount of cooling air, making it difficult to powerfully cool the muffler body 9.

Therefore, the present invention was proposed in order to solve the above problem, and its purpose is to reduce the back pressure of the cooling air sent to the ventilation space and to enable powerful cooling of the muffler body.

<Means for Solving the Problems> In order to achieve the above object, the present invention has a cooling air outlet 2 as shown in FIGS. 1 to 4, for example.
3 at the upper part of the peripheral wall of the muffler cover 11, an air inlet 25 at the lower part of the muffler cover 11, and an air outlet 24 at the lower side of the cooling air outlet 23 at the upper position of the peripheral wall of the muffler cover 11. This is how it was done.

<Function> The cooling air forced into the cooling air outlet 13 by the fan 28 powerfully cools the exhaust inlet 22 and the high temperature part of the upper part of the muffler body 9.
released to the outside.

Muffler body 9 below from cooling air outlet 23
As the air in the ventilation space 10 at its outer circumference is warmed and rises, it is cooled by the outside air sucked in from the air inlet 25. And ventilation space 10
The heated and raised air is discharged outward from the air outlet 24.

<Example> Hereinafter, an example of the present invention will be described based on the drawings.

FIG. 1 shows a vertical sectional side view of a muffler cover attached to a vertical air-cooled side valve type engine, and FIG. 2 shows an exploded perspective view of the muffler cover.

In the figure, reference numeral 1 indicates the entire side valve type engine, and this engine 1 includes a cylinder block 3 integrally formed above a crankcase 2, and a cylinder head 4 mounted and fixed on the upper surface of the cylinder block 3. An engine body 5 is formed.

An intake and exhaust block 6 is formed on the left side of the cylinder block 3, and a muffler device 8 is supported by an exhaust pipe 30 at an exhaust port 7 of the intake and exhaust block 6.
is installed.

This muffler device 8 consists of a muffler body 9 and a muffler cover 11 that covers the outer periphery of the muffler body 9 with a ventilation space 10 opened. 1
It is designed to be guided by a guide 14 provided on the outside of 3 and fed under pressure.

As shown in FIG. 3, the muffler main body 9 has a sound damping chamber 31 surrounded by a sound absorbing material 30, and a first expansion chamber 17, a second expansion chamber 18, and a third expansion chamber with spherical partition walls 15 and 16. Divided into 19 three chambers, first expansion chamber 1
7 and the second expansion chamber 18, and the second expansion chamber 18 and the third expansion chamber 19 are communicated through communication pipes 20 and 21, respectively,
Exhaust gas supplied from the exhaust inlet 22 opening into the first expansion chamber 17 is sent to the first expansion chamber 17, the communication pipe 20, and the second expansion chamber 17.
While flowing from the expansion chamber 18, the communication pipe 21, and the third expansion chamber 19 to the exhaust port 23, expansion and contraction are repeated to muffle the sound.

Muffler cover 11 that covers the outer periphery of muffler body 9
As shown in FIGS. 1, 2, and 4, there is a cooling air outlet 2 in the upper part of the front wall (peripheral wall) 11a.
3, an air outlet 24 is provided at the lower part near the cooling air outlet 23, and an air inlet 25 is provided at the lower part of the front surface 11a and the bottom wall (peripheral wall) 11b, and each of these openings 23, 24, 25 is formed with a long hole.

Then, an air outlet 24 and an air inlet 25
An exhaust outlet 26 is formed between the exhaust outlet 26 and the exhaust outlet 27 of the muffler main body 9 facing outside.

Further, the engine cooling device 12 that supplies a part of the engine cooling air to the cooling air inlet 13 is blown up by the rotation of a flywheel fan 28 provided on the front surface of the crankcase 2, as shown in FIG. Cooling air is sent to the cylinder block 3 using the fan case 29.
A guide 14 is configured to guide the cooling air to the cylinder head 4 by cutting out the exhaust port 7 portion of the fan case 29 and guiding a portion of the cooling air forced into the cylinder block 3 along the exhaust pipe 30.
The cooling air is supplied to the cooling air inlet 13 through the air.

The operation of the muffler cooling device configured as described above will be explained next.

Engine 1 is operated and flywheel fan 2
8 is rotated, the flywheel fan 28
Cooling air is generated within the fan case 29. The cooling air generated in this way is guided to the fan case 29, most of it is sent to the cylinder block 3 and cylinder head 4, and a part of it is passed through the guide 24 from the notch of the fan case 29 to the cooling air inlet. 13.

The cooling air forced into the ventilation space 10 from the cooling air outlet 13 strongly cools the exhaust pipe 22, which is particularly hot, in the muffler body 9, and is then discharged to the outside from the cooling air outlet 23. In this case, a portion of the cooling air may be discharged to the outside from the upper end of the air outlet 24.

On the other hand, in the muffler main body part below the cooling air outlet 23, the air in the surrounding ventilation space 10 is warmed by the heat of the muffler main body 9, becomes lighter and rises, and is discharged to the outside from the air convection outlet 24. It is cooled by convection that draws in outside air from the air inlet 25.

In the above embodiment, each opening of the cooling air outlet 23, the air outlet 24, and the air inlet 25 is formed as a long hole. It may be formed with a circular hole having a large diameter.

Further, the cooling air supplied to the ventilation space 10 is not limited to the engine cooling air blown by the flywheel fan 28, and a dedicated fan may be provided in the cooling air inlet 13.

<Effects of the invention> As described above, the present invention powerfully cools the upper part of the muffler body, which gets particularly hot, with the cooling air generated by the fan and discharges it from the cooling air outlet. The two halves are cooled by convection that enters from the air inlet and exits to the air outlet, so the two cooling winds do not interfere with each other. This allows the muffler body to be powerfully cooled with a large amount of cooling air.

[Brief explanation of drawings]

Figures 1 to 4 show an embodiment of the present invention, with Figure 1 being a partially cutaway longitudinal sectional front view of a vertical air-cooled side valve type engine, Figure 2 being an exploded perspective view of the muffler cover, and Figure 3 being an exploded perspective view of the muffler cover. 4 is a side view of the muffler cover, and FIG. 5 is a longitudinal sectional front view of the main parts of the conventional example. 9...muffler body, 10...ventilation space, 11...
...Muffler cover, 13...Cooling air inlet, 22
...Exhaust inlet, 23...Cooling air outlet, 24...
...Air outlet, 25...Air inlet, 28...
…Juan.

Claims (1)

[Scope of utility model registration request] An exhaust inlet 22 is provided at the top of the vertically long muffler main body 9, a ventilation space 10 is provided around the outer circumference of the muffler main body 9, and the muffler cover 11 is provided, and a cooling air inlet 13 is provided at the top of the muffler cover 11. A muffler cooling device configured such that a cooling air outlet 23 is opened in a part of the cooling air outlet 23, and cooling air generated by a fan 28 is supplied to the ventilation space 10 from the cooling air outlet 13 and discharged to the outside from the cooling air outlet 23. , a cooling air outlet 23 is provided in the upper part of the peripheral wall of the muffler cover 11 , an air inflow port 25 is provided in the lower part of the muffler cover 11 , and a cooling air outlet 23 is provided in the upper part of the peripheral wall of the muffler cover 11 on the lower side of the cooling air outlet 23 . A muffler cooling device characterized by having an air outlet 24.