JPH0664721U - Electric heating catalyst carrier - Google Patents

Abstract

(57) [Abstract] [Object] The present invention relates to a catalyst carrier mounted on an automobile, an industrial vehicle or the like for purifying exhaust gas, and in particular, an electric device for heating a catalyst carrier by electricity. It is an object of the present invention to reliably prevent a current flow from being biased to a position inside a bent portion of a band-shaped heating catalyst carrier. [Configuration] Corrugated plate-shaped catalyst carrier 41 made of a conductive metal
The band-shaped body 31 and the band-shaped body 31 are laminated by bending the band-shaped body 31 formed by stacking
In the electrically heated catalyst carrier in which the insulator 35 is disposed between and, the portion of the catalyst carrier 41 located at the bent portion 31a of the strip 31 is formed into a flat plate shape.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a catalyst carrier mounted on an automobile, an industrial vehicle or the like for purifying exhaust gas, and more particularly to an electrically heated catalyst carrier adapted to heat a catalyst carrier by electricity.

[0002]

[Prior art]

 Generally, a catalytic converter is arranged in the exhaust system of an automobile in order to purify the exhaust gas.However, in such a catalytic converter, the catalyst is not activated when the temperature of the catalyst carrier is low, so that the catalytic converter is not activated. At the time of starting, there was a problem that it was difficult to sufficiently purify the exhaust gas.

Therefore, conventionally, as disclosed in, for example, Japanese Patent Publication No. 3-500911, the electricity used to heat the catalyst carrier by electricity when the temperature of the catalyst carrier is low and the engine or the like is started. Heated catalyst supports have been developed.

FIG. 6 shows an electrically heated catalyst carrier of this type. In this electrically heated catalyst carrier, a core portion 13 is formed by bending a single strip 11 into a zigzag shape and stacking the layers. Has been done.

An insulating material 15 made of, for example, a ceramic plate or a ceramic cloth is interposed between the strip-shaped bodies 11 adjacent to each other. As shown in FIG. 7, the strip 11 is formed by laminating a corrugated plate 17 and a flat plate 19 which are catalyst carriers.

A pair of electrodes 21 and 23 are arranged at both ends of the strip 11, and the electrodes 21 and 23 are welded to a flat plate 19 located outside the strip 11 by welding or the like. It is fixed.

In such an electrically heated catalyst carrier, when a voltage is applied between the electrode 21 on one side and the electrode 23 on the other side, the band-shaped body 11 is energized, and the band-shaped body 11 is removed by the electric resistance of the band-shaped body 11. Get fever.

[0008]

[Problems to be solved by the device]

 However, in such a conventional electrically heated catalyst carrier, in the bent portion 11a of the strip 11, the current flow is biased to a position inside the bent portion 11a, and only this portion is locally heated. There was a problem.

That is, in general, the current easily flows to the low resistance side, and in the bent portion 11a, the outer peripheral side has a long path length and the higher resistance, so that the current flows to the inner peripheral side with a shorter path length. Becomes easier to flow.

When the bent portion 11a is locally heated, the corrugated plate 17 and the flat plate 19 may be melted and damaged due to overheating, and since the outer peripheral side of the bent portion 11a does not generate heat, Air-gas purification efficiency is reduced.

The present invention has been made to solve the above-mentioned conventional problems, and an electric heating catalyst capable of reliably preventing a current flow from being biased to a position inside a bent portion of a strip. The purpose is to provide a carrier.

[0012]

[Means for Solving the Problems]

 The electrically heated catalyst carrier according to the present invention is formed by stacking a corrugated plate-shaped catalyst carrier made of a conductive metal into a zigzag shape to form a laminated band and a band. In an electrically heated catalyst carrier having an insulator disposed between the catalyst carrier and the catalyst carrier, the portion of the catalyst carrier located at the bent portion of the strip is flat.

[0013]

[Action]

 In the electrically heated catalyst carrier of the present invention, the portion of the catalyst carrier located at the bent portion of the strip is made flat, so that at the bent portion of the strip, the catalyst carrier located inside and the catalyst carrier located outside There is almost no difference in the path length of the catalyst carrier, and the bias of the current flow at the bent portion of the strip is eliminated.

[0014]

【Example】

 Hereinafter, the details of the present invention will be described with reference to the embodiments shown in the drawings. FIG. 1 shows one embodiment of the electrically heated catalyst carrier of the present invention. In this electrically heated catalyst carrier, a core member 33 is formed by bending a single strip 31 into a zigzag shape. Are formed.

An insulating material 35 is inserted between the adjacent strip-shaped bodies 31. A pair of electrodes 37, 39 are arranged at the ends of the strip 31, and these electrodes 37, 39 are fixed to the outside of the strip 31 by welding or the like.

In this embodiment, however, the strip-shaped body 31 is formed by laminating the strip-shaped catalyst support bodies 41 made of thin plates. As shown in FIG. 2, the catalyst carrier 41 is formed by alternately forming corrugated plate-shaped portions 41a and corrugated flat plate-shaped portions 41b.

The flat plate-shaped portion 41 b of the catalyst carrier 41 is arranged so as to be positioned at the portion of the strip-shaped body 31 located at the bent portion 31 a. The corrugations formed on the corrugated plate-shaped portion 41a are formed so as to be inclined at a predetermined angle with respect to the width direction of the catalyst carrier 41.

Further, as shown in FIG. 3, one side A or the other side B of the catalyst carrier 41 of the adjacent catalyst carriers 41 in the band-shaped body 31 is prevented so that the corrugations of the corrugated plate-like portions 41a do not overlap. It is arranged to face each other.

Further, the adjacent catalyst carriers 41 in the strip 31 are joined to each other by brazing or diffusion joining. It should be noted that both ends of the catalyst carrier 41 are formed into flat plate-shaped portions 41b, and the electrodes 37 and 39 are fixed to the flat plate-shaped portion 41b by welding or the like.

Further, in the catalyst carrier 41 described above, a band-shaped flat plate is continuously wave-shaped by a molding gear, and then the corrugations located in the flat plate-shaped portion 41b are molded into a flat plate, or It is manufactured by pressing a band-shaped flat plate to form corrugations on the corrugated plate-shaped portion 41a.

Although a gap is formed between the adjacent flat plate-like portions 41b in FIG. 1, this is for the purpose of explanation, and in reality, they are abutted against each other, and are brazed or diffusion-bonded. They are joined together.

In the electrically heated catalyst carrier described above, when a voltage is applied between the electrode 37 on one side and the electrode 39 on the other side, the catalyst carrier 41 of the strip 31 is energized and the catalyst carrier 41 is charged. The catalyst support 41 is heated by the air resistance.

In the above-mentioned electrically heated catalyst carrier, however, the portion of the catalyst carrier 41 located at the bent portion 31a of the belt-shaped body 31 is flat, so that the bent portion 31a of the belt-shaped body 31 is There is almost no difference in the path length between the catalyst carrier 41 located inside and the catalyst carrier 41 located outside, and it is ensured that the current flow is biased to the position inside the bent portion 31a of the strip 31. It becomes possible to prevent it.

In this embodiment, since the flat plate 19 conventionally arranged on the band-shaped body 31 is unnecessary, the band-shaped body conventionally composed of, for example, 5 corrugated plates and 6 flat plates is It can be configured by using five catalyst carriers 41, and the degree of concentration of electric current to the bent portion 31a can be further reduced.

Further, in the electrically heated catalyst carrier of this embodiment, the flat plate 19 conventionally arranged on the strip 31 is not required, so that the weight of the carrier can be significantly reduced as compared with the conventional carrier. Since the heat capacity of the carrier is reduced, the temperature rising rate of the carrier can be improved, and the cost of the carrier can be reduced.

Further, since the corrugated plate-shaped portion 41a of the catalyst carrier 41 is formed to have an inclined waveform, stirring of the exhaust gas is promoted and the purification performance can be improved. It should be noted that in the above-described embodiment, an example in which the waveform of the corrugated plate-like portion 41a is formed by simply inclining in one direction has been described, but the present invention is not limited to such an embodiment, and for example, FIG. Alternatively, as shown in FIG. 6, it goes without saying that it may be formed so as to be inclined in a plurality of directions.

Further, in the embodiment described above, an example in which the belt-shaped body 31 is formed by the same catalyst carrier 41 has been described, but the present invention is not limited to this embodiment, and a plurality of types of catalyst carriers may be supported. The band may be formed by a body, and in this case, it is needless to say that a simple flat plate 19 may be used for one type of catalyst carrier.

[0028]

[Effect of device]

 As described above, in the electrically heated catalyst carrier of the present invention, since the catalyst carrier of the portion located at the bent portion of the strip is made flat, the catalyst located inside the bent portion of the strip is formed. There is almost no difference in the path length between the carrier and the catalyst carrier located on the outer side, and it is possible to reliably prevent the current flow from being biased to the position inside the bent portion of the strip. is there.

[Brief description of drawings]

FIG. 1 is a front view showing an embodiment of an electrically heated catalyst carrier of the present invention.

2 is an explanatory view showing the catalyst carrier of FIG. 1. FIG.

FIG. 3 is an explanatory view showing a method of arranging a catalyst carrier on a strip.

FIG. 4 is a front view showing another example of the catalyst carrier.

FIG. 5 is a front view showing another example of the catalyst carrier.

FIG. 6 is a front view showing an example of a conventional electrically heated catalyst carrier.

FIG. 7 is an enlarged sectional view showing a bent portion of the belt-shaped body of FIG.

[Explanation of symbols]

 31 band-like body 31a bent portion 35 insulating material 41 catalyst carrier 41a corrugated plate-like portion 41b flat plate-like portion

Claims (1)

[Scope of utility model registration request] 1. A belt-shaped body (31) formed by laminating corrugated plate-shaped catalyst carriers (41) made of a conductive metal is bent and folded in a zigzag shape to form a laminated belt-shaped body (3).
An electrically heated catalyst carrier comprising an insulator (35) disposed between 1) and a strip (31), wherein the strip (31)
An electrically heated catalyst carrier, characterized in that the portion of the catalyst carrier (41) located at the bent portion (31a) is made flat.