JPH0611839U - Metal catalytic converter - Google Patents

Abstract

(57) [Summary] [Object] The present invention relates to, for example, a metal catalytic converter mounted in an exhaust system of an automobile, and more specifically, a current is passed along a longitudinal direction of a strip-shaped metal honeycomb carrier to heat it. It is an object of the present invention to prevent peeling between the insulating member between the layers of the core and the metallic honeycomb carrier. [Structure] The insulating member is composed of a strip-shaped ceramic fiber cloth 5, and a folded-back holding plate 6 is sandwiched between the end portions of the ceramic fiber cloth 5 to be integrated, and the core portion 7 is made of metal which is opposed to and adjacent to each other in each layer. A ceramic fiber cloth 5 in which the folded-back holding plate 6 is integrated is sandwiched between portions of the honeycomb carrier 4, and the folded-back holding plate 6 is fixed to the metallic honeycomb carrier 4.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to, for example, a metal catalytic converter mounted in an exhaust system of an automobile, and more particularly to a metal catalytic converter in which a current is passed along a longitudinal direction of a strip-shaped metal honeycomb carrier to heat it.

[0002]

[Prior art]

 Generally, an exhaust system of an automobile is equipped with a metal catalytic converter, which removes unburned components such as CO and HC components in exhaust gas by burning the exhaust gas. However, the temperature of the exhaust gas is low at the beginning of engine operation, especially when the outside air temperature is low, such as during the winter, so the temperature of the catalyst carrier in the metal catalytic converter does not warm and the temperature is low. Combustion becomes insufficient.

Therefore, it is required to rapidly heat and warm the catalyst carrier in the metal catalytic converter at the start of engine operation. For example, in the metal catalytic converter, a metal catalytic converter in which an electric current is passed through the metallic honeycomb carrier to resistance-heat it is disclosed in Japanese Patent Laid-Open Publication No. 3-500911.

FIG. 10 and FIG. 11 show an example of this type of metal catalytic converter. In the figure, reference numeral 21 denotes a metal catalytic converter, and this metal catalytic converter 21 has a cylindrical container 22 in which metal shells 22A, 22A are aligned in the middle, and the central part of the cylindrical container 22 is provided. An electrothermal catalyst carrier 23 is housed. The electrothermal catalyst carrier 23 is arranged inside the cylindrical container 22 and is surrounded and held by a cylindrical insulating material 24 made of ceramic paper or the like.

The electrothermal catalyst carrier 23 is composed of a core portion 30 in which a strip-shaped metal honeycomb carrier 25 is folded in a meandering manner in multiple stages. The metal honeycomb carrier 25 includes a metal corrugated plate 25 A and a flat plate 25 B. It is configured by stacking.

Electrodes 26 and 27 are provided at both ends of the metallic honeycomb carrier 25. The electrodes 26 and 27 penetrate the tubular insulating material 24 and the tubular container 22 to form the tubular container 22. It projects outside and is connected via a power supply (not shown). Insulating collars 26A and 27A are provided on the outer circumferences of the electrodes 26 and 27, respectively, to insulate the shell 22 from the electrodes 26 and 27.

Insulating members made up of insulating plates 28 are interposed between the respective layers of the metallic honeycomb carrier 25 folded in a zigzag manner in multiple stages. The insulating plate 28 is for causing a current to flow between the electrodes 26 and 27 in a meandering shape in the metal honeycomb carrier 25 folded in a meandering shape along the longitudinal direction thereof. That is, this is to prevent a current short circuit between a predetermined step portion of the metal honeycomb carrier 25 and another adjacent step portion.

Therefore, when the engine is started, the current flows in a meandering shape along the longitudinal direction of the metallic honeycomb carrier 25 folded in a meandering shape between the electrodes 26 and 27 as indicated by an arrow X. . Due to the resistance heating of this current, the core portion 30 is wholly heated and rapidly heated.

[0009]

[Problems to be solved by the device]

 However, in the conventional metal catalyst converter, in order to prevent a current short circuit between a predetermined layer portion of the metal honeycomb carrier 25 and a portion of another adjacent layer, the metal honeycomb carrier 25 of the metal honeycomb carrier 25 is prevented. An insulating plate 28 is provided between each layer portion, and the insulating plate 28 and the metal honeycomb carrier 25 are adhered by a high temperature adhesive.

The metal honeycomb carrier 25 thermally expands and contracts in the longitudinal direction due to the change in the temperature of the exhaust gas. However, the coefficient of thermal expansion of the metal honeycomb carrier 25 differs from that of the insulating plate 28. The difference is that the metallic honeycomb carrier 25 and the insulating plate 28 are easily peeled off, and it is difficult to secure the holding of the insulating plate 28.

Therefore, there is a problem in that the gas flow of the exhaust gas causes a problem such as displacement and dropout of the insulating plate 28. The present invention has been made to solve the above-mentioned problems, and an object thereof is to provide a metal catalytic converter capable of preventing the insulating member between the respective layers of the core part and the metal honeycomb carrier from being separated from each other. That is.

[0012]

[Means for Solving the Problems]

 According to the first aspect of the present invention, a single honeycomb honeycomb carrier made of a strip plate having electrodes at both ends is folded in multiple stages along the longitudinal direction via an insulating member to form a metallic honeycomb carrier. In a metal catalytic converter for forming a layered core part and heating the core part by passing an electric current along the longitudinal direction of the metal honeycomb carrier between electrodes at both ends of the metal honeycomb carrier, It is composed of a strip of ceramic fiber cloth, and a folded-back holding plate is sandwiched between the ends of the ceramic fiber cloth to integrate them, and folded-back is held between the portions of the core section that face each other and are adjacent to each other in the honeycomb carrier made of metal. It is characterized in that the plate is integrated with a ceramic fiber cloth and the folded back holding plate is fixed to a metal honeycomb carrier.

According to a second aspect of the present invention, in the first aspect of the present invention, a burring hole is formed in the folded-back holding plate, and the folded-back holding plate is integrated with the end portion of the ceramic fiber cloth through the burring hole. It is characterized by having done.

[0014]

[Action]

 In the invention according to claim 1, portions of the core portion on both sides of the metal honeycomb carrier facing each other in each layer are insulated by a ceramic fiber cloth, and a metal honeycomb carrier is formed between electrodes at both ends. A core is heated by passing an electric current along the longitudinal direction.

The metal honeycomb carrier thermally expands and contracts, but due to frictional force, the ceramic fiber cloth freely expands and contracts following the thermal expansion and contraction of the metal honeycomb carrier. Here, a ceramic fiber cloth in which a folded-back holding plate is integrated is sandwiched between the facing and adjacent portions of the metal honeycomb carrier in each layer of the core, and the folded-back holding plate is fixed to the metallic honeycomb carrier. Therefore, the ceramic fiber cloth is held between the folded-back holding plates by the holding force of the fixed folded-back holding plates.

Therefore, the ceramic fiber cloth is brought into close contact between the portions of the metal honeycomb carriers facing each other in each layer through the folded-back holding plate, and the ceramic fiber cloth is not attached to the exhaust gas flow. Remains stuck to between.

According to the second aspect of the present invention, the fold holding plate is formed with a burring hole, and the wrap holding plate is integrated with the end of the ceramic fiber cloth through the burring hole. And the ceramic fiber cloth are reliably integrated.

[0018]

【Example】

 Hereinafter, the application of the present invention to an automobile catalytic converter will be described with reference to the drawings.

1 to 7 show a metal catalytic converter according to an embodiment of the present invention. 1 to 3, reference numeral 1 denotes a metal catalytic converter, and the metal catalytic converter 1 has a cylindrical container 2 having metal shells 2A and 2A aligned in the middle thereof. The electrothermal catalyst carrier 3 is housed in the central portion. This electrothermal catalyst carrier 3 is surrounded and held by insulating members 2B, 2B and washer wire meshes 2C, 2C arranged inside the cylindrical container 2.

The electrothermal catalyst carrier 3 is composed of a metal honeycomb carrier 4, an insulating member made of a strip-shaped ceramic fiber cloth 5, and a core portion 7 composed of a folded-back holding plate 6 fitted into an end of the ceramic fiber cloth 5. have.

More specifically, the metal honeycomb carrier 4 is formed by stacking metal corrugated plates 4A and flat plates 4B, and the ceramic fiber cloth 5 is made of metal in a state of being bent in a U shape. The honeycomb carrier 4 is covered on the U-shaped portion of each layer.

As shown in FIGS. 6 and 7, a burring hole 8 is formed in the folded-back holding plate 6, the burring hole 8 bites into the ceramic fiber cloth 5, and is folded and held at the end of the ceramic fiber cloth 5. The plate 6 is securely integrated. This is obtained by sandwiching the end portion of the ceramic fiber cloth 5 shown in FIG. 5 in the folded-back holding plate 6 and pressing it.

Then, as shown in FIG. 4, the ceramic fiber cloth 5 in which the folded-back holding plate 6 is integrated is sandwiched between the portions of the metal honeycomb carrier 4 of the core portion 7 which face each other and are adjacent to each other. The outer side surface of the folded back holding plate 6 is fixed to the metallic honeycomb carrier 4 by brazing.

The ceramic fiber cloth 5 is used to insulate the adjacent portions of the metal honeycomb carrier 4 between the layers of the core portion 7 which face each other. Then, electrodes 9 and 10 are provided at both ends of the metallic honeycomb carrier 4, and the electrodes 9 and 10 penetrate the cylindrical container 2 and project to the outside of the cylindrical container 2 to supply a power source (not shown). Connected through. Insulating collars 9A and 10A are provided on the outer circumferences of the electrodes 9 and 10 to insulate the shell 2 from the electrodes 9 and 10.

Then, when a voltage is applied between the electrodes 9 and 10, the portion 4C of a predetermined layer of the metal honeycomb carrier 4 overlaps with the portion 4D of another layer adjacent to it, but The portion 4C of the metal honeycomb carrier 4 is insulated from the portion 4D of the other layer by the ceramic fiber cloth 5, and the portion 4C of the predetermined layer of the metal honeycomb carrier 4 is electrically connected to the portion 4D of the other adjacent layer. Short circuit is prevented. Therefore, an electric current flows in a meandering shape between the electrodes 9 and 10 in the metal honeycomb carrier 4 folded in a meandering shape along the longitudinal direction thereof. Due to the resistance heating of this current, the core portion 7 is entirely heated and rapidly heated.

As a result, at the start of engine operation when the outside air temperature is low, such as in winter, the electrothermal catalyst carrier 3 in the metal catalyst converter 1 is rapidly heated and warmed, and the unburned components in the exhaust gas are sufficiently burned. Can be done When the temperature of the exhaust gas becomes high, the supply of current between the electrodes 9 and 10 is stopped.

Here, the ceramic fiber cloth 5 in which the folded-back holding plates 6 are integrated is sandwiched between the metal honeycomb carriers 4 of the core portion 7 which are adjacent and face each other in each layer, and the folded-back holding plates 6 are Since it is fixed to the metal honeycomb carrier 4, the ceramic fiber cloth 5 is held between the folded-back holding plates 6 by the holding force of the folded-back holding plates 6.

Therefore, the ceramic fiber cloth 5 is closely adhered between the metal honeycomb carriers 4 facing each other in each layer through the folded-back holding plate 6, and the ceramic fiber cloth 5 is made of a metal against the exhaust gas flow. The fixed state remains between the manufactured honeycomb carriers 4.

According to the above-mentioned configuration, the metallic honeycomb carrier 4 thermally expands and contracts in the longitudinal direction due to the change in the temperature of the exhaust gas, but the core portions 7 are adjacent to each other in each layer and face each other. A ceramic fiber cloth 5 in which a folded back holding plate 6 is integrated is sandwiched between portions of the metallic honeycomb carrier 4, and the folded back holding plate 6 is fixed to the metallic honeycomb carrier 4, so that the folded back holding is performed. The ceramic fiber cloth 5 is held between the folded back holding plates 6 by the clamping force of the plates 6.

Therefore, the ceramic fiber cloth 5 can be tightly held between the metal honeycomb carriers 4 facing each other in each layer through the folded-back holding plate 6 and can be securely held, and the ceramic fiber cloth 5 is displaced. Can be prevented.

Further, avoiding the use of an adhesive for high temperature which causes a difference in the coefficient of thermal expansion between the metal honeycomb carrier 4 and the ceramic fiber cloth 5, the ceramic fiber cloth 5 is folded and held by the metal honeycomb through the holding plate 6. It is possible to prevent the ceramic fiber cloth 5 from slipping and falling off from the metallic honeycomb carrier 4 by mechanically bonding to the carrier 4 to ensure fixation.

In this embodiment, the fold-back holding plate 6 is provided with a burring hole 8 and the burring hole 8 integrates the fold-back holding plate 6 with the end of the ceramic fiber cloth 5. It is also possible to integrate the folding-back holding plate 6 with the end portion of the ceramic fiber cloth 5 only by the clamping force of the folding-back holding plate 6 without the number 8.

Further, in the present embodiment, the outer side surface of the folded-back holding plate 6 is fixed to the metallic honeycomb carrier 4 by brazing, but the fixedness between the folded-back holding plate 6 and the metallic honeycomb carrier 4 is as described above. The examples shown below are not limited to brazing. (1) The folded back holding plate 6 and the metal honeycomb carrier 4 can be fixed to each other by diffusion bonding. (2) It is also possible to provide burring holes protruding inside and outside of the folded-back holding plate 6 and fix the folded-back holding plate 6 and the metal honeycomb carrier 4 through the burring holes projected outside. (3) As shown in FIG. 8, flange portions 11A and 11A are formed on both sides of the folded-back holding plate 11 having no burring holes, and the folded-back holding plate 11 is sandwiched between the layers of the metallic honeycomb carrier 4. For example, the folded-back holding plate 11 can be fixed between the front end face 4E and the rear end face 4F of the metallic honeycomb carrier 4 by the flange portions 11A, 11A. (4) As shown in FIG. 9, even if there is no means for fixing to the metal honeycomb carrier 4 on the side of the metal carrier 4 for holding the folded carrier plate 12 having no burring holes, And the two sides 12A, 12A of the folded-back holding plate 12 are positioned between the washer wire meshes 2C, 2C, and the folded-back holding plate is held on the metallic honeycomb carrier 4 by the nipping force of the metallic honeycomb carrier 4. 12 can also be fixed. In this case, since the holding force of the folded-back holding plate 12 is inferior to the above-mentioned various fixing methods, when the metal honeycomb carrier 4 is housed in the metal shells 2A, 2A, the metal honeycomb carrier is stored. This is effective when the washer wire meshes 2C, 2C are to be accommodated in the outer peripheral corner of No. 4 (see FIG. 2).・ Mesh 2C, 2C serves as a stopper to prevent misalignment.

Furthermore, the present invention is not limited to the above-described embodiment, but can be widely applied to a catalytic converter of an internal combustion engine.

[0035]

[Effect of device]

 As described above, according to the present invention, the metal honeycomb carrier thermally expands and contracts in the longitudinal direction due to the change in the temperature of the exhaust gas, but the metal honeycomb carriers are adjacent to each other in each layer of the core part. The ceramic fiber cloth with the folded-back holding plate integrated is sandwiched between the parts of the metal honeycomb carrier to be held, and the folded-back holding plate is fixed to the metal honeycomb carrier. , A ceramic fiber cloth is held between the folded back holding plates.

Therefore, the ceramic fiber cloth can be firmly held by being tightly held between the portions of the metal honeycomb carriers facing each other in each layer through the folded-back holding plate, and the deviation of the ceramic fiber cloth can be prevented. can do.

Further, avoiding the use of a high-temperature adhesive that causes a difference in the coefficient of thermal expansion between the metal honeycomb carrier and the ceramic fiber cloth, the ceramic fiber cloth is attached to the metal honeycomb carrier through the folded back holding plate. There is an effect that it is possible to prevent the ceramic fiber cloth from slipping or falling off from the metal honeycomb carrier by mechanically bonding and ensuring the fixation.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a metal catalytic converter according to an embodiment of the present invention.

FIG. 2 is a vertical cross-sectional view showing the same metal catalytic converter.

3 is a perspective view showing an upper portion of the electrothermal catalyst carrier of FIG. 1. FIG.

FIG. 4 is a perspective view showing a sandwiched state of the ceramic fiber cloth of FIG.

FIG. 5 is a perspective view showing the ceramic fiber cloth and the folded-back holding plate of FIG.

6 is a perspective view showing a folded-back holding plate integrated with the ceramic fiber cloth of FIG.

FIG. 7 is a cross-sectional view showing a folded-back holding plate integrated with the ceramic fiber cloth of FIG.

FIG. 8 is a perspective view showing a first modified example of the folded-back holding plate.

FIG. 9 is a perspective view showing a second modification of the folded back holding plate.

FIG. 10 is a cross-sectional view of a conventional metal catalytic converter.

FIG. 11 is an external view of the same metal catalytic converter.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Metal catalyst converter 3 Electrothermal catalyst carrier 4 Metal honeycomb carrier 5 Ceramic fiber cloth 6 Folding holding plate 7 Core part 8 Burring hole 9 Electrode 10 Electrode

Claims (2)

[Scope of utility model registration request] 1. A metal honeycomb carrier (4) in the form of a strip plate, which has electrodes (9, 10) on both ends, is folded in multiple stages along the longitudinal direction with an insulating member interposed between the electrodes to form a metal film. A core portion (7) formed by layering the honeycomb carrier (4) is formed, and the metal honeycomb carrier (4) is formed between the electrodes (9, 10) at both ends of the metal honeycomb carrier (4) in the longitudinal direction thereof. A metal catalytic converter for heating a core part (7) by passing an electric current along the insulating member, wherein the insulating member is composed of a strip-shaped ceramic fiber cloth (5), and a folded-back holding plate () is provided at an end of the ceramic fiber cloth (5). The ceramic fiber cloth (5) in which the folded-back holding plate (6) is integrated between the facing and adjacent metal honeycomb carriers (4) in each layer of the core part (7) by sandwiching and integrating the above (6). ) Is sandwiched and folded back Metal catalytic converter bets (6), characterized by being fixed in a metal honeycomb carrier (4). 2. The fold-back holding plate (6) is formed with a burring hole (8), and the fold-back holding plate (6) is integrated with the end of the ceramic fiber cloth (5) through the burring hole (8). The metal catalytic converter according to claim 1, wherein