JPH0610135Y2 - Catalyst converter - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a catalytic converter, and more particularly to a catalytic converter made of metal.

(Prior Art) Among catalytic converters, there is one in which a catalyst carrier is made of metal as seen in Japanese Utility Model Publication No. 52-32753. This type is called a metal catalyst, and many studies have been made to put it into practical use because of its ease of manufacturing.

In such a situation, due to heat dissipation due to its thermal conductivity,
It has the disadvantage of poor heat retention.

It is considered effective to interpose a heat insulating material between the metal catalyst and the casing against such a problem.

However, if the heat insulating material is simply interposed, the exhaust gas may blow through the heat insulating material without being purified. Moreover, the gas attack of the exhaust gas may cause thermal insulation of the heat insulating material, which may further promote the blow-through.

Therefore, an object of the present invention is to provide a metal catalyst, that is, a catalytic converter that solves the above problems that occur when a heat insulating material is interposed between a metal catalyst carrier and a casing. .

(Means and Actions for Solving Problems) In order to achieve the above-mentioned object, in the present invention, in a catalytic converter in which a metal catalyst carrier is housed in a casing, the metal catalyst carrier has an outer periphery, A heat insulating material having thermal expansion characteristics is provided over substantially the entire axial center of the metal catalyst carrier, the heat insulating material is covered with a deformable metal seal plate, and the seal plate is the metal It is configured to be joined to the catalyst-made catalyst carrier at the outer circumference of the upstream end and the outer circumference of the downstream end.

With such a structure, the metal catalyst carrier is
Of course, the heat insulating material suppresses the heat dissipation,
This heat insulating material follows thermal expansion and the like, and secures a reliable sealing property even at high temperatures. Further, the thermal expansion property of the heat insulating material enhances the holding power of the metal catalyst carrier. Since the seal plate covering the heat-expandable heat insulating material is deformable, the seal plate does not suppress the heat expansion of the heat-expandable heat insulating material. Also, with this seal plate, there is no need to cover the heat-expandable heat insulating material and worry about blowout of exhaust gas, and since the heat-expandable heat insulating material does not come into direct contact with exhaust gas, heat deterioration due to gas attack is also avoided. Will be reduced.

Further, while covering the heat insulating material with a deformable metal seal plate, the seal plate is joined to the metal catalyst carrier at the upstream end outer circumference and the downstream end outer circumference, so that the heat insulating material is applied to the outer circumference. When the provided metal catalyst carrier is mounted on the casing, the heat insulating material can be protected and held, and the heat insulating material can be prevented from peeling off or shifting. Therefore, it is possible to easily mount the metal catalyst carrier having the heat insulating material on the outer periphery in the casing.

Embodiment An embodiment of the present invention will be described below with reference to the drawings.

FIG. 2 shows an exhaust system E of an automobile engine. The exhaust system E is composed of an exhaust manifold 1, an exhaust pipe 2, and a silencer 3 in this order from the engine body (not shown) side. The pipe 2 is provided with a catalytic converter 10 that purifies harmful components in the exhaust gas.

As shown in FIG. 1, the catalytic converter 10 has a casing 12, which is made of stainless steel, in which a catalyst 14 is accommodated via a heat insulating material 16.

First, the catalyst 14 will be described. As shown in FIG. 3, the core (carrier) 18 is formed by spirally winding a stack of a flat thin plate 20 and a corrugated thin plate 22 each formed in a strip shape from a stainless thin plate. Has been formed. The metal core 18 is provided with
Similar to the one disclosed in Japanese Patent No. 753, a catalyst (Pt, etc.) is formed by coating the front and back surfaces of the flat thin plate 20 and the corrugated thin plate 22.
Is carried.

As the heat insulating material 16, an interram mat is adopted here. As is known, the interram mat is made by adhering leucite to a ceramic fiber.
(vermiculite) is composed of hydrous magnesium silicate containing A and Fe, and its volume is about 6 to 2 at high temperature.
It has the characteristic of expanding to 0 times. The heat insulating material 16 having such a thermal expansion property is mounted here by forming the core 18 and then winding it around the outer peripheral surface thereof, and the outer surface of the heat insulating material 16 is covered with the seal plate 24. .

The seal plate 24 is made of an ultra-thin stainless steel plate, and its upstream end 24a (left side in FIG. 1) and downstream end 24b (right side in FIG. 1) are spot-welded to the outer peripheral surface of the core 18.

The heat insulating material 16 and the seal plate 24 thus attached to the outer peripheral surface of the core 18 are attached to the casing 12 in a compressed state.

In the above configuration, heat transfer from the metal core 18 (catalyst 14) to the casing 12 is suppressed by the heat insulating material 16, and the heat retention of the catalyst 14 is secured. And
At high temperatures, the thermal expansion of the heat insulating material 16 strengthens the integrity of the casing 12 and the catalyst 14 via the heat insulating material 16, and the holding force of the catalyst 14 is increased. Further, since the seal plate 24 is formed of an extremely thin material, it is possible to sufficiently follow the thermal expansion of the heat insulating material 16 due to its deformability, and the thermal expansion of the heat insulating material 16 is not suppressed. Further, since the heat insulating material 16 is not directly exposed to the exhaust gas by the seal plate 24, the risk of thermal deterioration is reduced, and in addition, it is possible to reliably prevent the exhaust gas from blowing through. To be done.

Further, while the heat insulating material 16 is covered with a deformable metal seal plate 24, the seal plate 2
4 is spot-welded to the core 18 at the outer circumference of the upstream end and the outer circumference of the downstream end.
When it is mounted on the second heat insulating member 16, the heat insulating member 16 can be protected and held, and the heat insulating member 16 can be prevented from peeling off, shifting, and the like. Therefore, it is possible to easily attach the core 18 having the heat insulating material 16 on the outer periphery to the casing 12.

FIG. 4 shows a second embodiment. The same elements as those in the above embodiment are designated by the same reference numerals to omit the description thereof, and only the characteristic portions of the present embodiment will be described below.

In this embodiment, when the core 18 is formed, the flat thin plate 20
A heat insulating material 16 sufficient to sufficiently cover the outer periphery of the core 18 is attached to the inner surface of the winding end portion 20a of the flat plate 20
By simply winding a stack of the corrugated thin plate 22 and
The core 18 is formed with the heat insulating material 16 on the outer periphery thereof. In this case, the winding end portion 20 of the flat thin plate 20
a also serves as the seal plate 24 in the first embodiment. Then, the upstream end and the downstream end of the winding end portion 20a of the flat thin plate 20 and the winding end 20b are spot-welded. Thereby, the ease of manufacture can be obtained.

(Effect of the Invention) As is apparent from the above description, according to the present invention, it is of course possible to ensure the heat retention of the metal catalyst carrier.
Various effects such as reliably preventing blow-through of outside air gas by using a heat insulating material, increasing the holding power of the metal catalyst carrier at high temperature, and reducing heat deterioration of the heat insulating material can be obtained. It becomes possible.

Further, it is possible to easily mount the metal catalyst carrier having the heat insulating material on the outer periphery to the casing.

[Brief description of drawings]

1 to 3 show the first embodiment, FIG. 1 is a sectional view of a catalytic converter, FIG. 2 is an overall configuration diagram of an exhaust system of an engine, and FIG. 3 is III shown in FIG. It is a III-line sectional view. FIG. 4 shows the second embodiment and is an explanatory view of the main part thereof. 10: catalytic converter 12: metal catalyst carrier 16: heat insulating material 24: seal plate 24a: upstream end of seal plate 24b: downstream end of seal plate

Claims (1)

[Scope of utility model registration request] 1. A catalytic converter in which a metal catalyst carrier is housed in a casing, wherein the metal catalyst carrier has a thermal expansion property on the outer periphery of the metal catalyst carrier over substantially the entire axial direction of the metal catalyst carrier. A heat insulating material is provided, the heat insulating material is covered with a deformable metal seal plate, and the seal plate is joined to the metal catalyst carrier at an upstream end outer circumference and a downstream end outer circumference. Characteristic catalytic converter.