JP2550605Y2 - General purpose internal combustion engine silencer - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a silencer for a general purpose internal combustion engine having a function of purifying exhaust gas discharged from a general purpose internal combustion engine.

[0002]

2. Description of the Related Art From the viewpoint of environmental protection, HC, CO, and the like in exhaust gas discharged from a small general-purpose internal combustion engine as well as exhaust gas discharged from an internal combustion engine mounted on a vehicle are considered. There is an increasing demand for removing harmful gases such as NOx. In addition, general-purpose internal combustion engines have to be transported to various installation locations in a wide variety of applications, and auxiliary equipment such as fuel tanks and silencers must be compactly packed. If the purifying device is provided outside of these auxiliary machines, extra space is required by that amount, and it is difficult to reduce the size and weight of the engine.

[0003]

SUMMARY OF THE INVENTION The present invention relates to an improvement of a general-purpose internal combustion engine overcoming such difficulties, and in a muffler of a general-purpose internal combustion engine, a space inside the muffler is divided into two parts by a hollow separator. An inlet opening and an outlet opening for communicating the first and second chambers divided by the separator with the exhaust port of the internal combustion engine and the outside air are provided in the muffler, and are biased toward one of the spaces of the hollow separator. A communication port communicating with the first chamber is provided, and the second separator is biased toward the other of the space of the hollow separator.
A communication port communicating with the chamber is provided, and a fold of a wavy exhaust gas purification catalyst obtained by folding and folding a plate-like catalyst in a wave shape in the space of the hollow separator is directed in a direction connecting the both communication ports. The wavy exhaust gas purifying catalyst is provided.

According to the present invention, the exhaust gas discharged from the exhaust port of the general-purpose internal combustion engine and flowing into the first chamber through the inlet opening is connected to one of the hollow separators. After flowing into the space inside the hollow separator through the opening, and flowing toward the other communication port through the multiple branch passages partitioned by the wavy exhaust gas purifying catalyst, the second chamber flows from the other communication port to the second chamber. And is discharged to the atmosphere from an outlet opening of the second chamber.

As described above, in the present invention, during the passage from the first chamber to the second chamber through the branch passage, the expansion and the absorption by the wavy exhaust gas purifying catalyst in the hollow separator space are performed. Thus, exhaust noise is reduced.

In the present invention, since the exhaust gas discharged from the general-purpose internal combustion engine contacts the exhaust gas purifying catalyst in the hollow separator space over a wide contact area, even if the muffler is small, HC, CO, N in exhaust gas
Hazardous gases such as Ox are oxidized and reduced to be sufficiently removed.

Further, according to the present invention, even if a special exhaust gas purifying device is not separately provided, since the exhaust gas purifying function is provided, the layout of the auxiliary equipment of the general-purpose internal combustion engine which has been subjected to a pollution prevention measure can be simplified. The size and weight of the general-purpose internal combustion engine and the cost can be easily reduced.

[0008]

[Embodiment] An embodiment of the present invention shown in the drawings will be described below. The main body 2 of the silencer 1 having an exhaust gas purifying function is composed of an upper casing 3 and a lower casing 4 made of a thin steel plate which are divided into upper and lower parts, and an outer periphery of the hollow separator 5 is provided on a mating surface of the upper casing 3 and the lower casing 4. The upper casing 3 and the lower casing 4
As a result, the hollow separator 5 is integrally mounted on the main body 2, and the interior of the main body 2 is partitioned into a lower first chamber 6 and an upper second chamber 7 by the hollow separator 5.

Further, the hollow separator 5 is formed by superimposing partition plates 8, 9 in which the central portions of two upper and lower thin steel plates are bulged to the side and forming them in the middle by back-to-back superposition. Of the first chamber 6 in the partition plate 8 so as to be biased to one side of the space 10 of FIG.
A communication port 11 communicating with the second chamber 7 is provided in the partition plate 9 so as to be biased to the other side of the space 10.
Is provided.

[0010] In a further space 10 of the hollow separator 5, a thin steel sheet was folded bent multiplexed Al ₂ O ₃ was coated in a wave catalyst carrier comprising a wavy, platinum, rhodium, rare earth metals, Se Li um etc. Is filled in the space 10 of the hollow separator 5 by directing the fold 14 in the direction connecting the communication port 11 and the communication port 12 with the noble metal catalyst supported thereon. I have.

Further, bulging portions 15 and 16 bulging laterally in an L-shape are formed at end portions of the cutting plates 8 and 9 near the communication port 12, and a communication port 17 is provided in the bulging section 16. The ends of the bulging portions 15 and 16 of the partition plates 8 and 9 are formed with an exhaust outlet opening 18 communicating with the atmosphere.

Further, an exhaust pipe 19 whose upstream end is connected to an exhaust port of a general-purpose internal combustion engine (not shown) penetrates the lower casing 4 and is integrally attached to the lower casing 4. An exhaust inlet opening 20 communicating therewith is provided.

Since the illustrated embodiment is configured as described above, when a general-purpose internal combustion engine (not shown) starts operating, the exhaust port is opened via an exhaust pipe 19 through the exhaust port.
Exhaust gas is guided from 20 to the first chamber 6 in the lower casing 4 of the muffler 1, flows into one end side of the space 10 of the hollow separator 5 from the communication port 11 opened in the first chamber 6, The air flows in the space 10 toward the other end, flows from the communication port 12 at the other end to the second chamber 7, and further flows from the second chamber 7 through the communication port 17 to the bulging portions 15 and 16. , And is discharged from the space through the exhaust outlet opening 18 into the atmosphere.

As described above, the exhaust gas is supplied to the first chamber 6,
It flows while expanding in a stepwise manner with the first chamber 6 and the second chamber 7 of the hollow separator 5, and further restricts the communication ports 11, 12 and 17, and the exhaust gas purifying catalyst 13 in the first chamber 6. The level of exhaust noise is reduced by absorption.

When the exhaust gas passes through the space 10 of the hollow separator 5, the fold of the wavy exhaust gas purifying catalyst 13
Is oriented in the direction connecting the communication holes 11 and 12.
Therefore, since the exhaust gas comes into contact with the wavy exhaust gas purification catalyst 13 over a wide area, required oxidation and reduction reactions are performed,
Harmful gases such as HC, CO and NOx in the exhaust gas are sufficiently removed.

Since the muffler 1 has an exhaust gas purifying function, there is no need to provide a separate exhaust gas purifying device, and the size, weight and cost of a general-purpose internal combustion engine can be reduced.

[Brief description of the drawings]

FIG. 1 is a cross-sectional side view illustrating a silencer of a general-purpose internal combustion engine according to an embodiment of the present invention.

FIG. 2 is a longitudinal sectional front view thereof.

FIG. 3 is an enlarged exploded perspective view of the main part.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Silencer, 2 ... Main body, 3 ... Upper casing, 4 ... Lower casing, 5 ... Hollow separator, 6 ... First chamber, 7 ... Second chamber, 8, 9 ... Partition plate, 10 ... Space,
11, 12: communication port, 13: corrugated exhaust gas purification catalyst, 14: fold, 15, 16: bulging portion, 17: communication port, 18: exhaust outlet opening,
19: Exhaust pipe, 20: Exhaust inlet opening.

Claims (1)

(57) [Scope of request for utility model registration] 1. A silencer for a general-purpose internal combustion engine, wherein the internal space of the silencer is divided into two by a hollow separator, and first and second chambers divided by the separator communicate with an exhaust port of the internal combustion engine and outside air. An inlet opening and an outlet opening are provided in the muffler, and a communication port communicating with the first chamber is provided biased to one of the spaces of the hollow separator, and the communication port is biased to the other of the space of the hollow separator. A communication port communicating with the two chambers is provided, and in the space of the hollow separator, a fold of a wavy exhaust gas purification catalyst obtained by folding and folding a plate-like catalyst in a wave shape in a direction connecting the two communication ports. A muffler for a general-purpose internal combustion engine, wherein the exhaust gas purifying catalyst is disposed so as to be directed.