KR19980041765A - Catalytic Built-in Muffler - Google Patents

Abstract

It is a task to obtain a catalyst-embedded muffler having a high effect of removing sound and effectively using a space to reduce back pressure, and having a cylindrical shape in which a pair of first and second hard plates 12 and 13 are disposed at both ends. It is provided through the muffler main body 14, the monolith catalyst 16 which is provided inside the muffler main body 14, and divides the inside of the muffler main body into the inlet chamber 14a and the outlet chamber 14b, and the 1st light plate 12. And a plurality of first inlet pipes 17a formed in the portion facing the inlet chamber 14a and a plurality of first through holes 17a formed in the portion facing the inlet chamber 14b and facing the outlet chamber 14b. One end is connected to the outlet pipe 18 in which the second through hole 18a is formed, and the end of the inlet pipe 17 facing the inlet chamber 14a, and the other end of the inlet chamber 14a of the muffler body 14 is formed. Equipped with an exhaust gas diffusion cone (19) bonded to the inner peripheral surface. The air-conditioning sound absorption chamber 14c which communicates with the 1st through-hole 17a is formed in the exterior of the exhaust-gas diffusion cone 19 of the inlet chamber 14a.

Description

Catalytic Built-in Muffler

1 is a longitudinal sectional view of a catalyst-embedded muffler of the present invention.

2A is a view corresponding to FIG. 1 showing a conventional example.

2 (b) is a view corresponding to FIG. 1 showing an improved conventional example.

* Description of the symbols for the main parts of the drawings *

12. First tablets 13. 2nd hard board

14. The muffler body 14a. Entrance room

14b. Exit room 14c. HVAC

16. Monolith Catalyst 17. Inlet pipe

17a. First vent hole 18. Outlet pipe

18a. Second vent hole 19. Exhaust Gas Diffusion Body

The present invention relates to a muffler for removing the exhaust noise of the engine. It also relates to a muffler provided with a catalyst in detail.

As shown in FIG. 2A, a muffler 1 for removing exhaust noise of a conventional engine has a tubular muffler body whose both ends are sealed by a pair of first and second hard plates 2 and 3 ( The inside of the cylindrical muffler body 4 whose interior of 4) is sealed by the 1st and 2nd hard plates 2 and 3 is made of the 1st and 2nd partitioning plates 5, 6 The first to third expansion chambers 4a, 4b, and 4c are partitioned so that the tip of the inlet pipe 7 is inserted into the first expansion chamber 4a from the first expansion 2, and the outlet pipe 8 It is known that the base end of) is inserted into the third expansion chamber 4c from the second hard plate 3. A plurality of first small holes 7a are formed in a portion of the inlet pipe 7 located in the first expansion chamber 4a, and a portion of the outlet pipe 8 located in the third expansion chamber 4c. A plurality of second small holes 8a are formed.

Further, a first through hole 5a is formed in the first partition plate 5 to communicate the first and second expansion chambers 4a and 4b, and the second and third partitions 6 and 3 are formed in the first partition plate 6. Second communication holes 6a communicating with the expansion chambers 4b and 4c are formed. The muffler 1 configured in this way is connected to the upstream side exhaust pipe of which the base end of the inlet pipe 7 is not shown, and is connected to the downstream side exhaust pipe of which the front end of the outlet pipe 8 is not shown.

On the other hand, it is known that the catalyst 9 is incorporated in the 2nd expansion chamber 4b by the request of the multipurpose use of the muffler 1 in recent years. The catalyst 9 is provided through a pair of brackets 9a and 9a as shown in the drawing, and enters the second expansion chamber 4b from the first through hole 5a of the first partition plate 5. All of the exhaust gas is configured to enter the third expansion chamber 4c via the through hole 6a of the second partitioning plate 6 through this catalyst 9. The catalyst 9 is formed by supporting a noble metal such as Pt or Pd on a metal carrier made of ceramic support or metal such as porous alumina formed in a honeycomb shape, and SOF (Soluble Organic Fraction) in exhaust gas is It is oxidized by this catalyst and is purified by carbon dioxide or water and discharged to the atmosphere.

In this muffler 1, when the high-temperature or high-pressure exhaust gas discharged from the engine enters the first expansion chamber 4a from the first small hole 7a via the upstream side exhaust pipe and the inlet pipe 7, the first expansion chamber The pressure is reduced by expanding in (4a), and when the exhaust gas enters the second expansion chamber (4b) from the first through hole (5a) of the first partition plate (5), the sound is reduced. Removed. In the second expansion chamber 4b, the exhaust gas is purified by the catalyst 9 from the second expansion chamber 4b to the third expansion chamber 4c via the through hole 6a of the second partition plate 6. The pressure is also reduced when entering. In addition, the heat of the exhaust gas transmits the muffler body 4 having a large area and is dissipated to the atmosphere. As a result, the exhaust gas is purified and the exhaust sound is removed.

However, in the above-described catalyst-embedded muffler, the exhaust gas is complicated and the back pressure rises. That is, the exhaust gas entering the first expansion chamber 4a from the first small hole 7a through the inlet pipe 7 in the upstream exhaust pipe shown by the solid arrow marks in the drawing is the first of the first partition plate 5. It is necessary to penetrate into the second expansion chamber 4b from the through hole 5a and pass through the catalyst 9 supported by the bracket 9a, so that the back pressure rises due to the complicated flow of exhaust gas. In addition, due to this complexity, there is a problem that the exhaust gas does not pass evenly through the catalyst 9. In addition, the nonuniformity in the catalyst 9 also caused the tendency to raise the back pressure.

In order to solve this problem, as shown in FIG. 2 (b), the inlet pipe 7 is gently expanded toward the catalyst 9 and the exhaust gas is smoothed while the first expansion chamber 4a is removed. It is conceivable to lead to (9), but the effect of removing the sound of the muffler from the elimination of the first expansion chamber is reduced, and at the same time, the temperature is radiated from the enlarged inlet pipe to the outside to lower the catalytic performance and the inlet pipe. There is a problem that an unnecessary space is generated outside of (7).

An object of the present invention is to provide a catalyst-embedded muffler having a high effect of removing sound and reducing back pressure in order to eliminate unnecessary space generation.

The nickname according to claim 1 is a cylindrical muffler main body 14 and a muffler main body in which a pair of first and second hard plates 12 and 13 are disposed at both ends, as shown in FIG. (14) It is provided inside the monolith catalyst 16 which partitions the inside of the muffler main body 14 into the inlet chamber 14a and the outlet chamber 14b, and penetrates through the 1st light plate 12, and provides the inlet chamber 14a. Inlet pipe 17 having a plurality of first vent holes 17a formed in the facing portion, and a plurality of second vent holes 18a provided in the portion facing through the second hard plate 13 and facing the outlet chamber 14b. One end is connected to the formed outlet pipe 18 and the end of the inlet pipe 17 facing the inlet chamber 14a and the other end is attached to the inner circumferential surface of the inlet chamber 14a of the muffler body 14 for diffusion of exhaust gas. Catalyst formed in the air-conditioning and sound-absorbing chamber 14c which has the cone 19 and communicates with the 1st ventilation hole 17a outside the exhaust gas diffusion cone 19 of the inlet chamber 14a. A section muffler.

In the catalyst-embedded muffler 11 according to claim 1, when the exhaust gas enters the inlet chamber 14a through the inlet pipe 17, it expands from the first vent hole 17a to the air conditioning sound absorption chamber 14c. Sound is removed. The degassed exhaust gas is guided by the cone 19 in the inlet pipe 17 and smoothly transferred to the catalyst 16.

Next, embodiments of the present invention will be described in detail with reference to the drawings.

As shown in FIG. 1, the muffler 11 for removing the exhaust noise of the engine has a cylindrical muffler body 14 whose both ends are sealed by a pair of first and second hard plates 12 and 13. The monolith catalyst 16 is provided inside the muffler body 14. The monolith catalyst 16 exemplifies a catalyst of a ceramic carrier and a metal carrier. The monolith catalyst 16 is supported at both ends by a pair of brackets 16a and 16a, and the catalyst 16 is fixed by fixing the outer peripheral surfaces of the brackets 16a and 16a to the inner peripheral surface of the muffler body / 14. ) Is built into the muffler 1. In this embodiment, the catalyst 16 is an oxidation catalyst formed by dispersing and supporting Pt or Pd in a porous alumina carrier (not shown) formed in a honeycomb shape. In addition, by attaching in this way, the catalyst 16 partitions the inside of the muffler main body 14 into the inlet chamber 14a and the outlet chamber 14b.

The front end of the inlet pipe 17 is provided in the first light plate 12, and the base end of the outlet pipe 18 is inserted into the outlet chamber 14b in the second light plate 13. One end of the exhaust gas diffusion cone body 19 is connected to an end of the inlet pipe 17 facing the inlet chamber 14a, and the other end of the cone body 19 is connected to the inner circumferential surface of the inlet chamber 14a of the muffler body 14. Are glued. The cone 19 is configured to be gently enlarged from the inlet pipe 17 toward the catalyst 16, and the other end is adhered to the inner circumferential surface of the inlet chamber 14a to repartition the inlet chamber 14a to form the cone body 19. The air conditioning sound absorption chamber 14c is formed in the outside. In addition, a plurality of first vent holes 17a are formed in a portion of the inlet pipe 17 facing the inlet chamber 14a, and the first vent holes 17a are formed inside the inlet pipe 17 and the air conditioning and sound absorbing chamber 14c. ).

The outlet chamber 14b is clogged by the partition plate 21, and the end of the outlet pipe 18 inserted into the second hard plate 13 is fixed to the partition plate 21. A plurality of second vent holes 18a are formed in the outer circumferential portion of the outlet pipe 18 that faces the outlet chamber 14b, and a vent hole 21a is formed in the partition plate 21. The muffler 11 is connected to an upstream exhaust pipe (not shown) connected to the exhaust manifold of the engine, and the base end of the inlet pipe 17 is connected to the front end of the outlet pipe 18. The downstream exhaust pipe is connected.

The operation of the catalyst built-in muffler configured as described above will be described.

In the muffler 11, when the high-temperature or high-pressure exhaust gas discharged from the engine enters the inlet chamber 14a through the upstream side exhaust pipe and the inlet pipe 17, the air-conditioning and sound-absorbing chamber 14c in the first vent hole 17a. The sound is removed by inflation. The exhaust gas from which the sound has been removed passes from the inlet pipe 17 to the cone body 19, and is guided by the cone body 19 as shown by the arrow in the figure, and smoothly delivered to the catalyst 16. When the exhaust gas which has reached the catalyst 16 passes through the inside of the catalyst 16, SOF in the exhaust gas is oxidized by this catalyst and purified by carbon dioxide or water. The exhaust gas which has passed through the catalyst 16 proceeds to the outlet chamber 14b, and when it passes through the through-hole 21a of the partition plate 21, the pressure is reduced again, and the atmosphere is exhausted from the downstream exhaust pipe through the outlet pipe 18. Is released. In addition, the heat of the exhaust gas transmits the muffler main body 14 having a large area and is dissipated to the atmosphere.

As described above, according to the present invention, a monolith catalyst for dividing the interior of the muffler main body into an inlet chamber and an outlet chamber, an inlet pipe having a plurality of first vent holes formed in a portion facing the inlet chamber, and one end of the inlet pipe facing the inlet chamber. This connection is provided with an exhaust gas diffusion cone, the other end of which is bonded to the inner circumferential surface of the inlet chamber of the muffler body, and an air-conditioning and soundproof chamber communicating with the first vent hole is formed outside the exhaust gas diffusion cone of the inlet chamber. When entering the inlet chamber via the inlet pipe, the sound is removed by expanding from the first vent hole to the air-conditioning and sound absorption chamber, and the exhaust gas from which the sound is removed is guided by the cone in the inlet pipe and smoothly delivered to the catalyst. As a result, the catalyst-embedded muffler according to the present invention has a high effect of removing sound and can reduce the back pressure so that unnecessary space does not occur.

Claims (1)

A cylindrical muffler body 14 having a pair of first and second hard plates 12 and 13 disposed at both ends thereof, A monolith catalyst 16 provided in the muffler body 14 and partitioning the muffler body 14 into an inlet chamber 14a and an outlet chamber 14b; An inlet pipe 17 provided through the first plate 12 and having a plurality of first through holes 17a in a portion facing the inlet chamber 14a; An outlet pipe 18 provided through the second mirror plate 13 and having a plurality of second through holes 18a formed in a portion facing the outlet chamber 14b; One end is connected to an end of the inlet pipe 17 facing the inlet chamber 14a and the other end is provided with an exhaust gas diffusion cone 19 bonded to the inner circumferential surface of the inlet chamber 14a of the muffler body 14, , A catalyst built-in muffler, characterized in that the air-conditioning sound absorbing chamber (14c) in communication with the first through hole (17a) is formed outside the exhaust gas diffusion cone (19) of the inlet chamber (14).