JPH0130575Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an exhaust muffler for a small general-purpose internal combustion engine.

[Conventional technology and its issues]

As is well known, the exhaust gas discharged from the combustion chamber of an internal combustion engine has a pressure of 2 to 3 atmospheres, so if it is released into the atmosphere as it is, it will generate a high pitched sound. Therefore, an exhaust muffler consists of a passage, or air pocket, that rapidly expands the exhaust gas, and many resistance plates, gradually lowering the pressure and temperature, muffling the sound, and releasing it into the atmosphere. The basic types of exhaust mufflers include absorption type, reflective expansion type, and resistance type, and exhaust mufflers for small internal combustion engines are constructed from a combination of these types.

On the other hand, pollution caused by internal combustion engines includes air pollution, noise, vibration, etc., and countermeasures have been taken for a long time to improve these noises and vibrations in small general-purpose internal combustion engines. However,
Air pollution from exhaust black smoke from small general-purpose internal combustion engines;
Particularly in regard to the trapping of fuel and oil particles, prevention of this has recently begun depending on the application and location of the internal combustion engine.

For this reason, some exhaust mufflers for general-purpose small gasoline engines are equipped with wire-shaped traps called spark arresters as a measure against black exhaust smoke.

In other words, the trap attached to the exhaust muffler of conventional general-purpose small gasoline engines has a structure in which the exhaust pipe that connects the engine body and the muffler body can be removed separately, and the trap is attached to this exhaust pipe. . However, the muffler body is generally produced integrally with the exhaust pipe, and at engine assembly plants the exhaust pipe, which is integrated with the muffler body, is simply assembled onto the engine body. In the conventional case, the muffler body and exhaust pipe had to be assembled, which reduced productivity. Moreover, the need for a trap is limited to vehicle engines (for example, Japanese Patent Laid-Open No. 58-82012
(Refer to Publication No.), it is not necessary for general-purpose small internal combustion engines depending on the purpose and place of use. It takes time and effort to
In particular, when the engine was running for a long period of time, it was difficult to determine whether there was clogging or not, and it was also difficult to confirm that the engine's back pressure was increasing, which could lead to a decrease in the reliability of the engine. .

In addition, regarding the exhaust muffler for general-purpose small gasoline engines equipped with the above-mentioned trap,
Publication No. 127811 presents the following proposal. In other words, the vertically long tea cylinder-shaped muffler body is divided into upper and lower centers by a vertical plate, and an exhaust pipe is exposed on the upper side, and an opening for releasing exhaust gas is provided on the lower side. shows a structure in which a cylindrical trap is inserted.

However, in this configuration, since the muffler is exclusively used for small working machines, if the engine is operated with this trap removed, it will not be able to function as an exhaust muffler at all. Therefore, in such a configuration, there is an inconvenience that a trap must always be provided.

[Means to solve problems]

Therefore, the present invention was devised to completely eliminate these problems of the prior art, and its gist is that at the end of the exhaust passage of an internal combustion engine,
Through the exhaust pipe 2, the muffler body 4
In the exhaust muffler for a small general-purpose internal combustion engine, the muffler body 4 is provided with an exhaust gas release opening 24, and a trap 19 is inserted through the opening 24. A large diameter outer pipe 15 having a portion 24 and an air pocket 18 formed on the opening 24 side is installed horizontally, and a small diameter porous pipe 1 is inserted into the outer pipe 15 through a sound deadening material.
7 are partially overlapped and arranged in series, the trap 19 is provided with a flange, the trap 19 is inserted into the air pocket 18, and the flange is detachably fixed to the outer periphery of the muffler body 4. Found in the exhaust muffler of an internal combustion engine.

〔Example〕

The structure of the present invention will be explained in detail with reference to embodiments shown in the accompanying drawings.

1 is a sectional view of this embodiment, FIG. 2 is a side view taken in the direction of the arrow A in FIG. 1, FIG. 3 is a sectional view of a main part, and FIG. 4 is a side view taken in the direction of the arrow B in FIG.

In these figures, 1 is the engine body, 2 is the exhaust pipe attached to the engine body 1 with bolts, and 3 is the internal combustion engine of this embodiment, which is a general-purpose small gasoline engine that is directly connected to the generator and is covered with a soundproof box. The box is shown here. Reference numeral 4 denotes a muffler body, which is constructed by combining upper and lower bowl bodies 5 and 6. Since this lower bowl body 6 is installed on the outer periphery of the generator 7, its bottom has an inclined surface 8. A cover plate 9 covers the outer periphery of the muffler main body 4 via an air jacket 10. Therefore, a plurality of convex portions 11 are provided to protrude inside the cover plate 9, and these convex portions 11
is welded to the muffler body 4. 12 and 13 are support plates melted into the muffler body, and these support plates 1
2 and 13 support the muffler body 4 on the outer periphery of the generator 7.

A partition plate 14 is interposed between the upper bowl body 5 and the lower bowl body 6 of the muffler main body 4, and the opening of the exhaust pipe 2 is partitioned in half by the partition plate 14. This partition plate 14 has no holes on the exhaust pipe 2 side, and has porous holes on the other side.
Further, a cylindrical body 15' made of a partially overlapped double pipe is inserted into the lower bowl body 6 from the side opposite to the exhaust pipe 2. This cylindrical body 15' is constructed by fitting a small-diameter porous pipe 17 wrapped around a glass wool 16 into a large-diameter outer pipe 15 so that the glass wool 16 is partially polymerized. Because of this configuration, an air pocket 18 is formed in this cylindrical body 15'.

Exhaust gas release opening 2 of this outer pipe 15
4 has a trap 1 called a spark athlator.
9 is removably inserted. This trap 19
As shown in Figs. 3 and 4, it consists of an element 20 made of a metal rope in the shape of a tap, a funnel-shaped holder 21, and a plate-shaped stay 22 constituting a flange, which are integrally welded. ing. This holder 21 is pushed through the opening 24 of the outer pipe 15, and the bottom of the element 20 is positioned within the air pocket 18. The trap 19 is mounted by screwing a bolt into a hole in the stay 22 and a nut 23 (see FIG. 4) welded to the outside of the lower bowl body 6.

Since this embodiment is configured as described above,
To describe its function, exhaust gas from the engine flows from the exhaust pipe 2 into the upper bowl body 5 of the muffler body 4, where it is reflected and expanded, and then passes through the partition plate 14.
penetrate through the pores of At this time, the exhaust gas flows along the outer periphery of the cylindrical body 15' in a direction opposite to the inflow direction while being subjected to resistance, and flows into the porous pipe 17.
The flow is further constricted by the porous pipe 17, then expanded, and is discharged to the atmosphere from the opening 24 while being sound-absorbed by the glass wool 16. A trap 19 installed in the air pocket 18 of the outer pipe 15 traps fine particles of fuel and oil in the exhaust gas, and also traps sparks to prevent fire.

[Effect of idea]

According to the present invention, since a large-diameter outer pipe with an opening for exhaust gas release is installed horizontally, an air pocket can be formed in this outer pipe, and a trap can be installed in the dead space created by this air pocket, so that the trap can be removed easily. No extra space is required for mounting the device.

In particular, since it is composed of a large-diameter outer pipe and a small-diameter porous pipe that is partially polymerized and connected to this through a sound-deadening material, it can provide absorption and resistance functions as a muffler by itself. Even if the trap is removed, the function of the muffler will not be lost.

Since the trap is removably attached, it can be easily removed from the opening of the outer pipe in engines where a spark arrester is not required, making it possible to bring versatility to small general-purpose internal combustion engines.

Since the trap is inserted into the outer pipe through its opening and fixed by the flange, the outer pipe serves as a guide, and the trap fixing device can be simplified to a so-called cantilever shape.

[Brief explanation of the drawing]

1 is a sectional view of this embodiment, FIG. 2 is a side view taken in the direction of the arrow A in FIG. 1, FIG. 3 is a sectional view of a main part, and FIG. 4 is a side view taken in the direction of the arrow B in FIG. 2...Exhaust pipe, 4...Muffler body,
15...Outer pipe, 18...Air pocket, 19...
Trap device.

Claims (1)

[Claims for Utility Model Registration] A muffler body 4 is provided protrudingly from the end of an exhaust passage of an internal combustion engine via an exhaust pipe 2, an exhaust gas release opening 24 is provided in the muffler body 4, and the opening 24 In the exhaust muffler for a small general-purpose internal combustion engine in which a trap 19 is inserted, the muffler main body 4 is provided with a large diameter outer pipe 15 having the opening 24 and an air pocket 18 formed on the side of the opening 24. A small-diameter porous pipe 17 is installed horizontally and is connected to the outer pipe 15 through a sound deadening material.
are partially polymerized and connected, and the trap 1
9 is provided with a flange, the trap 19 is inserted into the air pocket 18, and the flange is inserted into the muffler body 4.
An exhaust muffler for a small general-purpose internal combustion engine that is removably fixed to the outer circumference of the engine.