JPH0576531U - Electrothermal catalyst carrier - Google Patents

Abstract

(57) [Summary] [Object] The present invention relates to an electrothermal catalyst carrier for a metal catalytic converter mounted in an exhaust system of an automobile. More specifically, a current is passed along a longitudinal direction of a strip-shaped metal honeycomb carrier. With respect to an electrothermal catalyst carrier that is heated by heating, it is an object of the present invention to prevent peeling between the insulating member between the layers of the core part and the metallic honeycomb carrier. [Structure] A strip-shaped metal honeycomb carrier 5 having electrodes 10 and 11 at both ends is formed with a core portion 6 via an insulating member 7, and the metal honeycomb carrier 5 is formed in the longitudinal direction thereof. In the electrothermal catalyst carrier that heats the core 6 by passing an electric current along the insulating member, the insulating member is composed of a ceramic fiber cloth 7, and the surface of the metallic honeycomb carrier 5 facing the ceramic fiber cloth 7 side is formed of a corrugated plate 5A. Of the core portion 6,
The ceramic fiber cloth 7 was sandwiched between the corrugated plate 5A portions of the metal honeycomb carriers 5 adjacent to each other in each layer.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an electrothermal catalyst carrier for a metal catalytic converter mounted in an exhaust system of an automobile, and more particularly, to an electrothermal catalyst carrier for heating by applying an electric current along the longitudinal direction of a strip-shaped metal honeycomb carrier.

[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 start of engine operation, especially when the outside air temperature is low, such as during the winter season. Combustion is 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 a metal catalytic converter, an electrothermal catalyst carrier for conducting resistance heating by passing an electric current through the honeycomb carrier made of metal is disclosed in JP-A-3-500911.

5 and 6 show an example of this type of metal catalytic converter. In the figure, reference numeral 21 indicates a metal catalyst converter, and this metal catalyst converter 21 has a cylindrical container 22 in which metal shells 22A, 22A are aligned in the middle, and the center of the cylindrical container 22 is formed. An electrothermal catalyst carrier 23 is housed in the portion. 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 cylindrical insulating material 24 and the cylindrical container 22 to form the cylindrical container 22. , And is connected via a power source (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 flowing an electric current between the electrodes 26 and 27 through 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, a 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 electrothermal catalyst carrier 23, in order to prevent a current short circuit between a predetermined step portion of the metal honeycomb carrier 25 and another adjacent step portion, the metal honeycomb carrier 25 is Insulating plates 28 are provided between the respective step portions, and the insulating plates 28 and the metallic 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 depends on the difference between the material of the metal honeycomb carrier 25 and the material 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 that the gas flow of the exhaust gas causes a problem such as displacement of the insulating plate 28 and slipping of the insulating plate 28. The present invention has been made to solve the above-mentioned problems, and an object thereof is to provide an electrothermal catalyst carrier capable of preventing peeling between an insulating member between respective layers of a core part and a metal honeycomb carrier. That is.

[0012]

[Means for Solving the Problems]

 According to the present invention, one strip-shaped metal honeycomb carrier having electrodes at both ends is made of metal by folding it in multiple stages along the longitudinal direction via an insulating member or winding it in multiple layers. In the electrothermal catalyst carrier, wherein a core portion formed by layering the honeycomb carrier is formed, and an electric current is applied to the metal honeycomb carrier between the electrodes at both ends of the metal honeycomb carrier along its longitudinal direction to heat the core member. The insulating member is made of ceramic fiber cloth, the surface of the metal honeycomb carrier facing the ceramic fiber cloth side is formed of corrugated plate, and the corrugated metal honeycomb carriers facing each other in each layer of the core part are formed. It is characterized in that a ceramic fiber cloth is sandwiched between the plate portions.

[0013]

[Action]

 In the present invention, the portions of the core portion on both sides of the metal honeycomb carrier facing each other in each layer are insulated by the ceramic fiber cloth, and the metal honeycomb carrier is extended along the longitudinal direction between the electrodes on both ends. Current is applied to heat the core.

Although the metal honeycomb carrier thermally expands and contracts, the ceramic fiber cloth has an inherent property of flexibly expanding and contracting with respect to an external force. Follow it and expand and contract freely.

Further, since the ceramic fiber cloth is sandwiched between the corrugated plates, the contact area between the ceramic fiber cloth and the corrugated plate is widened, and the resistance force to the exhaust gas flow due to friction is increased to increase the ceramic resistance. The fiber cloth is fixed between the corrugated plates of the metal honeycomb carrier and stopped.

[0016]

【Example】

 An embodiment of the present invention will be described below with reference to the drawings. An electrothermal catalyst carrier according to an embodiment of the present invention will be described with reference to FIGS. 1 to 4.

In FIG. 2, reference numeral 1 denotes a metal catalyst converter, and this metal catalyst converter 1 has a cylindrical container 2 in which metal shells 2A, 2A are fitted together in the middle. The electrothermal catalyst carrier 3 shown in FIG. 1 is housed in the central portion of 2. The electrothermal catalyst carrier 3 is arranged inside the cylindrical container 2 and is surrounded and held by a cylindrical insulating material 4 made of ceramic paper or the like.

The electrothermal catalyst carrier 3 is composed of a core portion 6 formed by folding a single strip-shaped metal honeycomb carrier 5 in a serpentine manner in multiple stages. Insulating members made of ceramic fiber cloth 7 impregnated with a ceramic adhesive having a coefficient of thermal expansion substantially the same as that of the honeycomb carrier 5 made of honeycomb are arranged in layers. The metal honeycomb carrier 5 is formed by stacking a metal corrugated plate 5A and a flat plate 5B.

As shown in FIGS. 3 and 4, the surface of the metallic honeycomb carrier 5 facing the ceramic fiber cloth 7 side is formed of a corrugated plate 5A. The ceramic fiber cloth 7 is sandwiched between the corrugated plates 5A of the metal honeycomb carrier 5 that face each other and are adjacent to each other in the core portion 6. The corrugated plate 5A of the metal honeycomb carrier 5 which is opposed to and is adjacent to the interlayer of the core portion 6 is insulated via the ceramic fiber cloth 7.

Then, electrodes 10 and 11 are provided at both ends of the metallic honeycomb carrier 5, and the electrodes 10 and 11 penetrate the cylindrical insulating material 4 and the cylindrical container 2 and the outside of the cylindrical container 2. It protrudes and is connected via a power supply (not shown). Insulating collars 10A and 11A are provided on the outer circumferences of the electrodes 10 and 11, respectively, to insulate the shell 2 from the electrodes 10 and 11.

When a voltage is applied between the electrodes 10 and 11, the predetermined step portion 5C of the metal honeycomb carrier 5 overlaps with the other step portion 5D adjacent to the predetermined step portion 5C, 5C is insulated from the other step portion 5D by the ceramic fiber cloth 7, and the predetermined step portion 5C of the metallic honeycomb carrier 5 is short-circuited with an adjacent other step portion 5D. Is prevented. Therefore, a current flows in a meandering manner along the longitudinal direction of the metallic honeycomb carrier 5 folded in a meandering manner between the electrodes 10 and 11 as shown by an arrow Y. Due to the resistance heating of this current, the core portion 6 is entirely heated and rapidly warmed.

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 burned. Can be fully performed. Then, when the temperature of the exhaust gas becomes high, the supply of current between the electrodes 10 and 11 is stopped.

Here, the metal honeycomb carrier 5 thermally expands and contracts, but the ceramic fiber cloth 7 has an inherent property of flexibly expanding and contracting with respect to an external force, so that the heat of the metal honeycomb carrier 5 is reduced. Freely expands and contracts following expansion and thermal contraction.

Further, since the ceramic fiber cloth 7 is sandwiched between the corrugated plates, the contact area between the ceramic fiber cloth 7 and the corrugated plate 5A is widened, and the frictional resistance to the exhaust gas flow is increased. However, the ceramic fiber cloth 7 is fixed between the corrugated plates 5A of the metallic honeycomb carrier 5 and stopped.

According to the above-mentioned configuration, the metal honeycomb carrier 5 thermally expands and contracts in the longitudinal direction due to the change in the temperature of the exhaust gas, but the core portions 6 are adjacent to each other in each layer and face each other. Since the ceramic fiber cloth 7 is sandwiched between the portions of the corrugated plate 5A of the metallic honeycomb carrier 5, the contact area between the ceramic fiber cloth 7 and the corrugated plate 5A is widened, and the ceramics against the exhaust gas flow are increased. It is possible to prevent the fiber cloth 7 from slipping or peeling from the corrugated plate 5A.

That is, it is possible to avoid using a high-temperature adhesive that causes a difference in thermal expansion coefficient between the metal honeycomb carrier 5 and the ceramic fiber cloth 7, and to use the frictional force of the ceramic fiber cloth 7 against the metal honeycomb carrier 5. Thus, the ceramic fiber cloth 7 can be securely held, and the ceramic fiber cloth 7 can be prevented from being displaced or dropped from the metal honeycomb carrier 5.

Of course, portions of the core portion 6 on both sides of the metal honeycomb carrier 5 facing each other in each layer are insulated via the ceramic fiber cloth 7, and the metal honeycomb is interposed between the electrodes 10 and 11 at both ends. The core portion 6 can be heated by passing an electric current through the carrier 5 along its longitudinal direction.

In this embodiment, the core portion is formed by folding the metallic honeycomb carrier 5 in a meandering manner in multiple stages. By winding the metallic honeycomb carrier 5, the ceramic fiber cloth 7 is layered. The present invention can be applied to the electrothermal catalyst carrier described above.

Further, in the present embodiment, the ceramic fiber cloth 7 is impregnated with the ceramic-based adhesive, but even if the ceramic-based adhesive is not impregnated, the ceramic fiber cloth 7 is merely frictional force. Can be sandwiched between the corrugated plates 5A of the metallic honeycomb carrier 5, and the ceramic fiber cloth 7 can be locked between the corrugated plates 5A of the metallic honeycomb carrier 5 and stopped.

[0030]

[Effect of the 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 carrier which is adjacent to and faces each other in each layer of the core portion. Since the ceramic fiber cloth is sandwiched between the corrugated sheet parts of the honeycomb carrier made of honeycomb, the contact area between the ceramic fiber cloth and the corrugated sheet is widened, and the ceramic fiber cloth becomes corrugated sheet against exhaust gas flow. It can be prevented from slipping off or coming off.

That is, by 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 utilized by utilizing the frictional force of the ceramic fiber cloth against the metal honeycomb carrier. The effect of being able to reliably hold the ceramic fiber cloth and prevent the ceramic fiber cloth from slipping or falling off from the metal honeycomb carrier is obtained.

[Brief description of drawings]

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

FIG. 2 is an external view of the same metal catalytic converter.

FIG. 3 is a plan view of the ceramic fiber cloth of FIG.

FIG. 4 is an enlarged cross-sectional view of a main part of FIG.

FIG. 5 is a sectional view of a conventional metal catalytic converter.

FIG. 6 is an external view of the metal catalytic converter.

[Explanation of symbols]

 3 Electrothermal catalyst carrier 5 Metal honeycomb carrier 5A Corrugated plate 6 Core part 7 Ceramic fiber cloth 10 Electrode 11 Electrode

Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display area F01N 3/24 L 3/28 301 P

Claims (1)

[Scope of utility model registration request] 1. A single strip-shaped metal honeycomb carrier (5) having electrodes (10, 11) on both ends is folded in multiple stages along the longitudinal direction via an insulating member (7). Or by multiple winding to form a core portion (6) in which the metal honeycomb carrier (5) is layered, and between the electrodes (10, 10,
11) In an electrothermal catalyst carrier for heating an electric current along the longitudinal direction of a metallic honeycomb carrier (5) to heat the core part (6), the insulating member is composed of a ceramic fiber cloth (7), The corrugated plate (5A) is formed on the surface of the honeycomb carrier (5) facing the ceramic fiber cloth (7) side, and the facing and adjacent metal honeycomb carriers (5) in each layer of the core part (6) are formed. An electrothermal catalyst carrier characterized in that a ceramic fiber cloth (7) is sandwiched between corrugated plate (5A) portions.