JP2540049Y2 - Exhaust gas purification device - Google Patents

Description

[Detailed description of the invention]

[0001]

INVENTION The present invention relates to a carbon monoxide contained in exhaust gas discharged from an internal combustion engine mounted on a vehicle such as a motorcycle (CO), nitrogen oxides (NO _X), carbide The present invention relates to an exhaust gas purifying apparatus for purifying toxic gas such as hydrogen (HC) by oxidation-reduction using a catalyst.

[0002]

2. Description of the Related Art In a conventional exhaust silencer described in Japanese Utility Model Publication No. 57-7767, a fibrous catalyst for purifying toxic gas in exhaust gas is penetrated through the rear wall of the expansion chamber, and is placed in the expansion chamber. Was wound around the outer periphery of a communication pipe with a small hole projecting from the fiber catalyst to cover the wire mesh on the fibrous catalyst.

[0003]

In the exhaust muffler described in the above-mentioned publication, since the catalyst attached to the communication pipe is fibrous, a holding means such as a wire mesh is required, which complicates the structure and reduces the productivity. Inexpensive, expensive, and likely to be scattered by the exhaust stream, low in durability, and the catalyst has parts that cannot be sufficiently contacted with the exhaust gas by holding means such as wire mesh. Was not high.

[0004]

SUMMARY OF THE INVENTION The present invention relates to an improvement of an exhaust gas purifying apparatus for an exhaust system overcoming such difficulties, and relates to an exhaust gas for purifying harmful gases in the exhaust gas by redox with a catalyst. In the gas purifying apparatus, the surface of the porous inner pipe loosely fitted to the inner surface of the exhaust outer pipe from the exhaust port of the internal combustion engine to the expansion chamber of the muffler with a space therebetween, the expansion chamber and a compartment behind the same. And a catalyst supported on the surface of the communication pipe supported by the rear wall of the expansion chamber.

In the present invention, since the catalyst carrier loosely fitted on the inner surface of the exhaust outer tube with a space therebetween is a porous inner tube, the surface area of the catalyst carrier is remarkably increased.
The catalyst supported on the porous inner tube not only comes into contact with the exhaust gas passing through the porous inner tube, but also passes through the porous inner tube and forms a space between the porous inner tube and the exhaust outer tube. Because it can touch exhaust gas that has entered the, it has high purification performance.
Further, since the porous inner pipe is loosely fitted to the exhaust outer pipe with a space therebetween, the porous inner pipe is exposed to the outside air and is maintained at a higher temperature than the exhaust outer pipe having a lower temperature. Maintained, and particularly at the time of starting the internal combustion engine, early activation of the catalyst becomes possible.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention shown in FIGS. 1 and 2 will be described below. Reference numeral 1 denotes a two-cycle internal combustion engine mounted on an on-road motorcycle. One end of an exhaust pipe 3 is fitted to an exhaust port 2 of the internal combustion engine 1.
The exhaust pipe 3 is provided with a stainless steel wool 5 for sound absorption and heat insulation along an inner surface of an outer plate 4 formed in a pipe shape.
Further, the suspension wool 5 is covered with a punching metal 6 having a large number of holes 7 so that the fibers of the suspension wool 5 are not scattered by the exhaust fluid.

At the end of the exhaust pipe 3 on the exhaust gas outflow side, one end of a diffuser pipe 8 formed so that its sectional area gradually increases as approaching the exhaust gas outflow side.

Further, a muffler 9 is detachably mounted so as to include the exhaust gas outflow end of the diffuser pipe 8. The outer plate of the muffler 9 The muffler outer plate 1
Numeral 0 is formed into two pieces by a press or the like on the surface oriented in the longitudinal direction, and is integrally attached to each other by seam welding or MIG welding. Covered with metal 6,
Further, partition plates 11 and 12 are integrally fixed to the inner wall of the muffler outer plate 10 by welding or the like, and the inside of the muffler 9 is separated by the partition plates 11 and 12 into a first compartment 13, a second compartment 14, and a third compartment 13. The first compartment 13 corresponds to the expansion chamber of the muffler in the claims for utility model registration.

The first compartment 13 and the third compartment 15 are communicated with each other by a communication tube 16 penetrating the partition plates 11 and 12, and the third compartment 15 and the third compartment 15 are connected by a communication tube 17 penetrating the partition plate 11. The two compartments 14 are communicated with each other, and the outside air is communicated with the second compartment 14 by a tail pipe 18 that penetrates through the partition plate 12 and the rear wall 10a of the muffler outer plate 10.

Further, the outer plate 4, the punched metal 6, the diffuser pipe 8, the muffler outer plate 10, the partition plate 11, the partition plate 12,
The communication pipe 16, the communication pipe 17, and the tail pipe 18 carry a catalyst 19 made of platinum or the like as described below.

That is, the outer plate 4, the diffuser pipe 8, and the muffler outer plate 10 have a punching metal 6 on the inner surface.
Are on both planes and on the inner peripheral surface of the hole, the diaphragm 11, the diaphragm 12, and the communication pipe.
16, the communication pipe 17, and the tail pipe 18 are coated with a powder of silica (SiO ₂ ), alumina (aluminum oxide) or the like on the entire surface of the member, and then baked to apply a ceramic coating having an uneven surface, After that, a catalyst such as platinum, palladium, and rhodium is deposited, and then baked, fitted, and fixed, and the catalyst 19 is coated on the ceramic coating.
Is carried.

Since the embodiment shown in FIGS. 1 and 2 is constructed as described above, the exhaust gas discharged from the internal combustion engine 1 passes through the exhaust pipe 3 and the diffuser pipe 8 and then passes through the muffler 9. After flowing into the first compartment 13 of the first through the communication pipe 16, into the third compartment 15, further through the communication pipe 17 into the second compartment 14, after passing through the tail pipe 18 into the atmosphere When the exhaust gas passes through these exhaust systems, the exhaust gas touches the catalyst 19 carried on the uneven surface of the member, causing toxic gas such as carbon monoxide and nitrogen compounds contained in the exhaust gas. Is redox.

Further, since a commonly used part is coated with a ceramic coating and the catalyst 19 is supported thereon, it is not necessary to change the structure of the exhaust system, which may affect the arrangement of other parts. No, and the increase in body gravity is also a minor factor.

Further, the exhaust gas is supplied to the exhaust pipe 3 and the first compartment.
When passing through 13, a part of the exhaust noise is absorbed by the suspension wool 5 disposed between the punching metal 6 and the outer plate,
By entering and exiting the first compartment 13, the third compartment 15, and the second compartment 14, the energy of exhaust sound waves is absorbed by expansion, reflection, resonance, and the like, and the volume of exhaust noise is reduced.

Also, in the embodiment shown in FIGS. 1 and 2, the suspension wool 5 is attached to the inner surface of the outer plate 4 of the exhaust pipe 3 and covered with the punching metal 6, but as shown in FIG. An exhaust pipe 20 in which the metal 5 and the punching metal 6 are not provided may be used.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional side view illustrating an embodiment of the present invention.

FIG. 2 is an enlarged vertical sectional side view of a main part of FIG.

FIG. 3 is an enlarged vertical sectional side view of a main part illustrating another embodiment.

[Description of Signs] 1 ... internal combustion engine, 2 ... exhaust port, 3 ... exhaust pipe, 4 ... outer plate, 5
... Sus wool, 6 ... Punched metal, 7 ... Hole, 8 ... Diffuser pipe, 9 ... Muffler, 10 ... Muffler outer plate, 11, 12 ... Separator plate, 13 ... First compartment, 14 ... Second compartment, 15 ...
Third compartment, 16, 17… Communication pipe, 18… Tail pipe, 19… Catalyst, 20… Exhaust pipe.

Claims (1)

(57) [Scope of request for utility model registration] 1. An exhaust gas purifying apparatus for purifying harmful gas in exhaust gas by oxidation-reduction with a catalyst, wherein the exhaust gas purifying device has a gap between an exhaust port of an internal combustion engine and an expansion chamber of a muffler with an interval therebetween. A catalyst is supported on the surface of the fitted porous inner tube, and on the surface of the communication tube supported on the rear wall of the expansion chamber while interconnecting the expansion chamber and the rear compartment. Exhaust gas purifying device.