JP2003206735A - Catalyst device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a catalyst device capable of suppressing the wind erosion of a catalyst body by effectively capturing a solid matter incapable of passing through the catalyst body. <P>SOLUTION: A catalyst device is provided with a catalyst carrier 1 equipped with a function purifying exhaust gas from an engine, a catalyst converter 2 storing the catalyst carrier 1 and a catalyst holding material 3 which is arranged between the catalyst carrier 1 and the catalyst converter 2 and held to by the catalyst converter 2 surrounding the catalyst carrier 1. The catalyst holding material 3 has a notch 4 capturing foreign matter A formed at the upstream side of the flow direction of the exhaust gas and flowing into with the exhaust gas, and prevents that foreign matters A incapable of passing through the catalyst carrier 1 repeatedly contacts to the upstream end of the flow direction of the catalyst carrier 1. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a catalyst device which is installed in an exhaust system of an automobile engine to purify exhaust gas.

[0002]

2. Description of the Related Art Generally,
An exhaust system of an automobile engine is provided with a catalytic converter (also referred to as a casing) immediately after the exhaust manifold or under the floor, and is incorporated in the catalytic converter via a holding member (also referred to as a catalyst holding material). for example, a three-way catalyst (also referred to as a catalyst body or catalyst support) by HC (hydrocarbon) in the exhaust gas, CO (carbon monoxide), are purified, reduced NO _X (nitrogen oxides) simultaneously.

By the way, in recent years, in order to improve the performance of the catalyst device, the catalyst main body (catalyst carrier) has been increased in cell density and wall thickness. That is, the exhaust gas performance is improved by increasing the surface area of the catalyst body. However, the strength of the catalyst body is reduced due to the thin wall, and welding spatter (metal dust) inside the exhaust system parts that flows in with the exhaust gas.
By repeatedly contacting solid matter (foreign matter) such as the above with the front end face portion of the catalyst body (the end face portion on the upstream side in the exhaust gas flow direction),
There was a problem that wind erosion of the catalyst body occurred.

Therefore, an object of the present invention is to provide a catalyst device capable of suppressing wind erosion of the catalyst body by effectively trapping solid substances that cannot pass through the catalyst body.

[0005]

To achieve the above object, a catalyst device according to the present invention comprises a catalyst body having a function of purifying exhaust gas from an engine, a casing for housing the catalyst body, In a catalyst device that is provided between the catalyst body and the casing, and includes a holding member that surrounds the catalyst body and holds the catalyst body in the casing, the holding member is provided on an upstream side in a flow direction of the exhaust gas. It has a capturing means for capturing the solid matter that is formed and flows in together with the exhaust gas, and prevents the solid matter that cannot pass through the catalyst body from repeatedly coming into contact with the upstream end face in the flow direction of the catalyst body. I decided to do it.

Further, the capturing means has a notch opening toward the upstream side in the flow direction, so that the structure is simplified.

Further, the trapping means is further provided with a discharge preventing portion for preventing the solid matter trapped in the cutout portion from being discharged to the outside, so that the trapping performance is improved.

Further, the upstream end in the flow direction of the holding member is provided at the downstream end in the flow direction with respect to the upstream end in the flow direction of the catalyst main body to obtain a double trapping function, An object is reliably prevented from repeatedly coming into contact with the upstream end of the catalyst body in the flow direction.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION A catalyst device according to the present invention will be described below in detail with reference to the accompanying drawings.

[First Embodiment] FIG. 1 is a perspective view of a catalyst device showing a first embodiment of the present invention, and FIG. 2 is a developed view of the catalyst holding material.

As shown in FIG. 1, a catalyst device provided in an exhaust system of an automobile engine has a catalyst carrier (catalyst body) 1 having a function of purifying exhaust gas from the engine, and the catalyst carrier 1. Converter housing (casing)
2 and a catalyst holding material (holding member) 3 which is disposed between the catalyst carrier 1 and the catalyst converter 2 and surrounds the catalyst carrier 1 and holds the catalyst carrier 2 in the catalyst converter 2.

The catalyst carrier 1 is formed of ceramics in the shape of a honeycomb cylinder, and has a high cell density and a thin wall.

The catalytic converter 2 is made of sheet metal,
An exhaust gas inlet 2b and an outlet 2c are provided in front of and behind the cylindrical storage portion 2a.
Is formed to have a diameter smaller than that of the cylindrical storage portion 2a.

The catalyst holding material 3 is formed of a heat-insulating and heat-resistant ceramic fiber into a cylindrical shape.
The rear both end surfaces (in the exhaust gas flow direction, the end surface on the downstream side) have a substantially trapezoidal shape (the end surface side is the upper side as a trapping means for capturing foreign matter (solid matter) b such as welding spatter flowing in together with the exhaust gas. A plurality of cutouts 4 (which serve as the bottom) are provided equidistantly in the circumferential direction.

The capturing means 4 may be provided only on the upstream side end face in the flow direction, but as shown in FIG. 2, if it is also provided on the downstream side end face in the flow direction, it is assembled. Sometimes it is easy because there is no constraint on the top and bottom (in the flow direction of the exhaust gas, downstream). Incidentally, 5a and 5b in FIG. 2 are fitting portions for assembling.

Further, the upstream end in the flow direction of the catalyst holding member 3 is provided in a stepwise manner with respect to the upstream end in the flow direction of the catalyst carrier 1 so as to fall to the downstream side in the flow direction. In the illustrated example, the downstream end of the catalyst holding material 3 in the flow direction is also provided in a stepped manner by dropping from the downstream end of the catalyst carrier 1 in the flow direction to the upstream side in the flow direction, but this is particularly necessary. Absent.

With such a configuration, the foreign matter a mixed in the exhaust gas from the engine and flowing into the catalytic converter 2 through the inlet 2b has a size that can pass through the cells of the catalyst carrier 1. It passes through the cells of the catalyst carrier 1 as it is and flows out of the catalytic converter 2 through the outlet 2c.

On the other hand, as shown by the arrow in FIG. 1, the foreign matter a having a size that cannot pass through the cells of the catalyst carrier 1 is first of all the upstream end of the catalyst carrier 1 in the flow direction and the catalyst holding material. Three
Are trapped in the gap between the inner peripheral wall of the catalytic converter 2 and the outer peripheral wall of the catalyst carrier 1, which is formed by the step difference from the upstream end of the flow direction.

After that, the foreign matter a trapped in the gap is flown into and trapped in the notch 4, and the inside of the notch 4 is formed by the above-mentioned shape of the notch 4 (substantially trapezoidal shape that does not easily come out when entering). The foreign matter B that has flowed into and captured in the notch 4
Stay inside. That is, the acute-angled portion 4a (the emission prevention portion) on the upper bottom side formed by the shape of the cutout portion 4 prevents the foreign matter a that has flowed into and trapped in the cutout portion 4 from being discharged to the outside, and thus the foreign matter a. Will stay in the notch 4.

This prevents foreign matter B, which cannot pass through the cells of the catalyst carrier 1, from repeatedly contacting the end face of the catalyst carrier 1 on the upstream side in the flow direction, and suppresses wind erosion of the catalyst carrier 1. .

[Second Embodiment] FIG. 3 is an explanatory view of the shape of a capturing means showing a second embodiment of the present invention.

In order to make the shape of the notch 4A as the trapping means in the first embodiment into a shape that is easy to enter and difficult to come out, the trapped foreign matter a is discharged to the outside in the middle of the rectangular notch 4A. Portion 4a as a release preventing portion for preventing
Is an example in which is provided.

According to this, the trapping performance of the foreign matter B is further improved.

The present invention is not limited to the above embodiments,
It goes without saying that various changes such as changing the shape of the capturing means can be made without departing from the scope of the present invention.

[0025]

As described above, according to the invention of claim 1, a catalyst body having a function of purifying exhaust gas from an engine, a casing for housing the catalyst body, the catalyst body and the casing. And a holding member that surrounds the catalyst body and holds the catalyst body in the casing, the holding member being formed on the upstream side in the flow direction of the exhaust gas, Since it is configured to have a capture means for capturing the solid matter that flows in together with the gas, it is possible to prevent the solid matter that cannot pass through the catalyst body from repeatedly contacting the flow-direction upstream end surface portion of the catalyst body, Wind erosion of the catalyst body is suppressed.

Further, according to the invention of claim 2, since the capturing means is constituted by the notch portion which opens toward the upstream side in the flow direction, the structure can be simplified.

Further, according to the invention of claim 3, the capturing means is further provided with a release preventing portion for preventing the release of the solid matter captured in the cutout portion to the outside. The performance can be improved.

Further, according to the invention of claim 4, the upstream end in the flow direction of the holding member is provided at the downstream side in the flow direction with respect to the upstream end in the flow direction of the catalyst body. , Double trap function is obtained.

[Brief description of drawings]

FIG. 1 is a perspective view of a catalyst device showing a first embodiment of the present invention.

FIG. 2 is also a development view of a catalyst holding material.

FIG. 3 is an explanatory view of the shape of a capturing means showing a second embodiment of the present invention.

[Explanation of symbols]

1 Catalyst carrier 2 catalytic converter 3 Catalyst holding material 4,4A notch 4a Constriction A foreign body

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 3G091 AA02 AB03 BA07 GA06 HA27                       HA28                 4D048 AA06 AA13 AA18 AB01 AB02                       BB02 BC08 CA01 CC03 CC08                       CC10                 4G069 AA03 AA15 CA03 CA07 CA08                       CA09 DA06 EA19 EB03

Claims (4)

[Claims] 1. A catalyst body having a function of purifying exhaust gas from an engine, a casing accommodating the catalyst body, and arranged between the catalyst body and the casing to surround the catalyst body. And a holding member for holding the casing in the casing, the holding member is formed on an upstream side in a flow direction of the exhaust gas, and a trapping unit that traps a solid matter that flows in together with the exhaust gas. A catalyst device having. 2. The catalyst device according to claim 1, wherein the trapping unit includes a notch opening toward the upstream side in the flow direction. 3. The catalyst device according to claim 2, wherein the trapping means is further provided with a discharge prevention portion for preventing the solid matter trapped in the cutout portion from being discharged to the outside. . 4. The upstream end in the flow direction of the holding member is provided at a step downstream in the flow direction with respect to the upstream end in the flow direction of the catalyst body. , 2 or 3 catalyst device.