JP2663215B2 - Exhaust muffler - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exhaust muffler used for a vehicle equipped with a diesel engine.

[0002]

2. Description of the Related Art Generally, in a vehicle equipped with a diesel engine, a catalytic converter is externally mounted on an exhaust muffler, or disposed in the middle of an exhaust pipe upstream of the exhaust muffler and used in an exhaust system. The exhaust resistance has been significantly increased and its diesel
In addition to the decrease in the output performance of the engine, the soot was increased, and the particulates tended to increase accordingly.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to make a catalytic converter replaceable so that it can be built-in, to make it compact and easily mountable on an automobile, to reduce exhaust resistance, and to suppress a decrease in engine output performance. Exhaust gas can be purified, and in addition, the noise reduction effect can be improved.

[0004]

SUMMARY OF THE INVENTION The present invention divides a cylindrical casing into a first-stage expansion chamber, an intermediate-stage expansion chamber, and a last-stage expansion chamber that are connected to each other by a plurality of partition plates. A catalyst converter package that incorporates a plurality of catalytic converters and is formed into a package having an internal expansion chamber portion between the catalytic converters, wherein a front and rear expansion chamber portion is formed in the intermediate stage expansion chamber; The catalytic converter purifies the exhaust of a diesel engine, and the middle stage expansion chamber, in which the catalytic converter package is located, effectively attenuates exhaust noise.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIGS. 1 to 6 show a specific embodiment 1 of an exhaust muffler according to the present invention which is disposed in the exhaust pipe 52 of a diesel engine 50 mounted on a truck. The exhaust muffler 1 is disposed at a predetermined interval in the axial direction within the cylindrical casing 2 having both ends closed by the front end wall 4 and the rear end wall 5, and Two partition plates 6 and 7 and three catalytic converters 1 forming a first-stage expansion chamber 8, an intermediate-stage expansion chamber 9, and a last-stage expansion chamber 10 in the cylindrical casing 2.
2, 13 and 14 are incorporated in the catalytic converter 1
2, 13 and 14, formed in a package having an internal expansion chamber portion 15 and disposed in the intermediate expansion chamber 9 to provide the front and rear expansion chamber portions 1 with the intermediate expansion chamber 9.
Catalytic converter package 11 forming 6, 17
And a number of small holes 36 are formed in the first-stage expansion chamber 8.
And the inlet pipe 18 arranged in the first-stage expansion chamber 8 when inserted into the first-stage expansion chamber 10. Similarly, the inlet pipe 18 is arranged in the last-stage expansion chamber 10 while being inserted into the last-stage expansion chamber 10 by forming a number of small holes 39. And the outlet pipe 19 provided.

The cylindrical casing 2 has the cylindrical wall 3 axially divided at an intermediate position in the axial direction of the intermediate-stage expansion chamber 9, and has flanges 20 and 21 at the divided ends, and The flanges 20 and 21 are connected to bolts and nuts 22 and 2.
It was assembled by tightening at 2. In particular, the cylindrical wall 3 and the front end wall 4 have a two-layer structure including glass felt.

The partition plates 6 and 7 have a plurality of holes 23 and 2
3 each and their diesel engine 50
Was pressed into the cylindrical casing 2 where it flows from the first-stage expansion chamber 8 to the middle-stage expansion chamber 9 and from the middle-stage expansion chamber 9 to the last-stage expansion chamber 10.

[0008] The catalytic converter package 11 comprises:
A cylindrical housing 24, a support plate 25, a cover plate 26, three catalytic converters 12, 13, 14 supported between the support plate 25 and the cover plate 26, and a space between the catalytic converters 12, 13, 14; and a internal expansion chamber portion 15 formed on and assembled to the package structure where forming the front and rear expansion chamber portion 16, 17 to Madan expansion chamber 9 therein. The support plate 25 has three elliptical holes 27, 27, 27 on the inner surface thereof.
7, 27, 27 at the positions associated with the three communication holes 28,
28, 28 are pressed, and one pipe receiving hole 29 is pressed. On the other hand, the cover plate 27 is provided with three lip-shaped elliptical holes 30, 30, 30 which are hole-flanged at positions corresponding to the elliptical holes 27, 27, 27 of the support plate 25. Also, the catalytic converters 12, 13, 14 are molded from ceramic powder, dried and fired, after which
A through-flow type elliptical ceramic honeycomb shell 31 carrying a catalyst on the surface and a half-pressed metal sheet are pressed, and the ceramic is interposed with cushioning materials 34, 34 and a sealing material 35. The outer shell of the honeycomb shell 31 and the flange 3
3 and 33 are assembled in a cartridge structure with the casing 32 spot-welded, and one end of the
Elliptical hole 3 with lip butted against 7, 27, 27
0, 30, and 30 were supported between the support plate 25 and the cover plate 26, and were assembled into an integral structure by welding. Of course, the catalyst contains CO, HC,
Normal substances that convert harmful components such as NO into CO ₂ , H ₂ O, N _{2 and the} like were used.

The inlet pipe 18 is connected to the first-stage expansion chamber 8.
The front end wall was inserted into the front end wall 4 and the partition plate 6 and the part was welded to the front end wall 4, and a flange 37 was welded to the front end extending outside the front end wall 4. In addition, the inlet pipe 18 has a pipe 38 extending at the rear end in the first-stage expansion chamber 8, and has a catalytic converter and / or a catalyst-converter disposed in the cylindrical casing 2 in the intermediate-stage expansion chamber 9.
The pipe 38 can be fitted into the pipe receiving hole 29 of the support plate 26 of the package 11. On the other hand, the outlet pipe 19 has its front end inserted into the final-stage expansion chamber 10, welds its part to the rear end wall 5 and the partition plate 7, and then extends to the outside of the rear end wall 5. The flange 40 was welded.

The exhaust muffler 1 assembled as described above is located immediately after the exhaust brake 53 arranged in the exhaust pipe 52 of the diesel engine 50 and at the rear end of the exhaust pipe 52 at the inlet pipe. Flange 18 and tail pipe (not shown)
The outlet pipe 19 was flanged and used for the exhaust system of the diesel engine 50.

Next, the exhaust muffler 1 thus incorporated into the exhaust system of the diesel engine 50
Will be described. When the diesel engine 50 is operated, exhaust flows from the exhaust manifold 51 to the exhaust pipe 52, and a portion of the exhaust is guided from the small hole 36 in the inlet pipe 18 into the first-stage expansion chamber 8, where it is located. Inflated. Next, the exhaust gas is supplied to the holes 2 of the partition plate 6.
It flows through 3 and 23 into the front expansion chamber part 16 of the intermediate-stage expansion chamber 9. On the other hand, the remaining part of the exhaust is led to the pipe 38 and the catalytic converter package 11
Flow from the inner expansion chamber portion 15 of the first expansion chamber portion 16 to the front expansion chamber portion 16 through the communication holes 28, 28, 28;
The oval hole 2 of the support plate 25 together with a part of the exhaust
7, 27, 27 to their catalytic converters 12, 13, 1
Flow to 4. In the catalytic converters 12, 13, and 14, harmful components such as CO, HC, and NO contained in the exhaust gas are converted into CO ₂ , H ₂ O, N _{2, and the} like. The exhaust gas thus purified by the catalytic converters 12, 13, 14 is supplied to the catalytic converters 12, 13, 14
Flows into the rear expansion chamber portion 17 and is then expanded. Further, the exhaust flows through the holes 23, 23 of the partition plate 7 to the final stage expansion chamber 10, where it is expanded again, and so the expansion is repeated so that the small pipe 39 has its outlet pipe. Flows into 19,
It flows from the outlet pipe 19 to the tail pipe and is released to the atmosphere.

In the exhaust muffler 1, when the exhaust gas passes through the catalytic converters 12, 13, and 14, harmful components are converted into harmless components, and in addition, the intermediate stage in which the catalytic converter package 11 is disposed. By the expansion chamber 9, that is, its catalytic converters 12, 13, 14
The exhaust sound is effectively attenuated by the internal expansion chamber portion and the front and rear expansion chamber portions 16 and 17. Further, since the cylindrical casing 2 has a split structure, the attachment and detachment of the catalytic converter package 11 is simplified, and accordingly, the exchange of the catalytic converters 12, 13, 14 is facilitated. Was.

[0013]

As will be understood from the above description, the exhaust muffler of the present invention has both ends closed by the front end wall and the rear end wall.
Cylindrical casing and an axial direction inside the cylindrical casing.
It is arranged at a predetermined interval and is
Form the first-stage expansion chamber, intermediate-stage expansion chamber, and final-stage expansion chamber
Combining multiple partition plates and multiple catalytic converters
With an internal expansion chamber between the catalytic converters
Formed in a package, and placed in its middle stage expansion chamber.
Form front and rear expansion chambers in the middle expansion chamber
And replaces the internal expansion chamber portion with the front expansion chamber portion
Catalytic converter package open to many
A hole is drilled and placed in the first stage expansion chamber, and
Connected by a pipe to its internal expansion chamber part of its middle stage expansion chamber
Inlet pipe and numerous small holes are drilled
This includes the outlet pipe located in the final stage expansion chamber.
In the exhaust muffler according to the invention, part of the exhaust gas is supplied to the first stage expansion chamber.
Through the catalytic converter, and at the same time,
The remaining part is led to the internal expansion chamber part and the catalyst core
Flows around the inverter, keeping the catalyst at a high temperature,
And the rest of the exhaust is in the front expansion chamber
Back to the minute where it is mixed with some of its exhaust,
The temperature is increased and led to the catalytic converter,
The catalyst and its exhaust are kept at a high temperature,
Catalyst is activated and its exhaust gas can be purified efficiently.
In addition, the exhaust resistance is suppressed to a small extent, and the decrease in engine output performance is suppressed.In addition, the silencing effect is dramatically improved, and furthermore, the catalytic converter can be replaced for each package. It enables miniaturization, and become readily be mounted on an automobile, the binding
Result, it is very useful and practical for automobiles.

As apparent from the embodiments of the present invention described above with reference to the drawings, for those having ordinary knowledge in the art to which the present invention belongs, the contents of the present invention are as follows: In order to achieve the object of the invention, it is essential to the establishment of the invention and is derived from the technical essence of the invention, which is the nature of the invention, and is easily converted to an aspect that is objectively recognized as being inherent. Be replaced.

[Brief description of the drawings]

FIG. 1 is a schematic view showing a diesel engine of a truck incorporating a specific example of an exhaust muffler of the present invention and an exhaust system thereof.

FIG. 2 is an axial sectional view of the exhaust muffler shown in FIG.

FIG. 3 is a sectional view taken along line 3-3 in FIG. 2;

FIG. 4 is a sectional view taken along line 4-4 in FIG. 3;

FIG. 5 is a partially enlarged sectional view of FIG. 4;

FIG. 6 is a cross-sectional view of a catalytic converter used for an exhaust muffler.

FIG. 7 is a sectional view taken along the line 7-7 in FIG. 6;

[Explanation of symbols]

 2 cylindrical casing 6 partition plate 7 partition plate 8 first stage expansion chamber 9 intermediate stage expansion chamber 10 last stage expansion chamber 11 catalytic converter package 12 catalytic converter 13 catalytic converter 14 catalytic converter 15 internal expansion chamber part 16 front expansion chamber part 17 rear Expansion chamber part

Claims (1)

(57) [Claims] 1. A cylindrical casing having both ends closed by a front end wall and a rear end wall, and a first stage expansion disposed in the cylindrical casing at predetermined intervals in an axial direction. chamber, the intermediate stage expansion chamber, and a plurality of partition plates to form the final stage expansion chamber incorporates a plurality of catalytic converters is formed in a package with an internal expansion chamber portion between them catalytic converter, the intermediate stage expansion chamber And the front and rear expansion chambers are formed in the middle stage expansion chamber.
And replaces the internal expansion chamber portion with the front expansion chamber portion
A catalytic converter package which opens, is arranged in the first stage expansion chamber is opened a number of small holes, and,
Connected by a pipe to its internal expansion chamber part of its middle stage expansion chamber
An exhaust muffler that includes an inlet pipe that is provided and an outlet pipe that has a number of small holes drilled and disposed in its final stage expansion chamber.