JPH0576528U - Electrothermal catalyst carrier - Google Patents

Abstract

(57) [Abstract] [Objective] The present invention relates to an electrothermal catalyst carrier for a metal catalytic converter mounted in an exhaust system of an automobile,
More specifically, the present invention relates to an electrothermal catalyst carrier for heating by applying an electric current along the longitudinal direction of a strip-shaped metal honeycomb carrier, and an object thereof is to prevent the insulating member between each layer of the core part and the metal honeycomb carrier from peeling off. And [Structure] A plurality of ceramic spherical bodies 8 having a diameter larger than the dimension thereof are sandwiched between portions of the core portion 6 which are adjacent to each other and are adjacent to each other in each layer of the metal honeycomb carrier 5. The insulating ceramic layer 7 is formed.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an electrothermal catalyst carrier of a metal catalytic converter mounted in an exhaust system of an internal combustion engine, particularly an exhaust system of an automobile, and more specifically, a current is passed along a longitudinal direction of a strip-shaped metal honeycomb carrier. The present invention relates to an electrothermal catalyst carrier for heating by heating.

[0002]

[Prior Art]

 Generally, an exhaust system of an internal combustion engine, for example, an exhaust system of an automobile, is equipped with a metal catalyst converter, and this metal catalytic converter converts unburned components such as CO and HC components in exhaust gas. However, the exhaust gas is burned and removed by the heat of the exhaust gas, but the temperature of the exhaust gas is low especially at the start of engine operation 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 rise and the temperature is Low, combustion of unburned components in exhaust gas 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.

6 and 7 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 layered plate-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 plates 28 are interposed between the respective layers of the metallic honeycomb carrier 25 folded in a serpentine shape in multiple stages. The insulating plate 28 is for causing a current to flow between the electrodes 26, 27 in a meandering shape along the longitudinal direction of the metal honeycomb carrier 25 folded in a meandering shape. That is, this is to prevent a current short circuit between a predetermined step portion of the metallic 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 first aspect of the present invention, one strip-shaped metal honeycomb carrier having electrodes at both ends is folded in multiple stages along the longitudinal direction or is wound in multiple layers to make the metal carrier. In the electrothermal catalyst carrier, the core part is formed by layering the honeycomb carrier, and the core part is heated by passing an electric current along the longitudinal direction of the metallic honeycomb carrier between the electrodes at both ends of the metallic honeycomb carrier. Part of each layer, an insulating ceramic layer formed by sandwiching a plurality of ceramic spherical bodies having a diameter larger than the dimension between the portions of the metal honeycomb carrier facing each other in each layer is formed. It is characterized by

According to a second aspect of the present invention, a metal honeycomb carrier is layered by folding a strip-shaped metal honeycomb carrier having electrodes on both ends thereof in multiple stages along the longitudinal direction. In the electrothermal catalyst carrier in which the core portion is formed, and the core portion is heated by passing an electric current along the longitudinal direction of the metal honeycomb carrier between the electrodes at both ends of the metal honeycomb carrier, in each layer of the core portion. Insulating ceramic layer formed by sandwiching a ceramic rod-shaped body having a diameter larger than the dimension between the portions of the metal honeycomb carrier facing each other facing each other in the direction perpendicular to the flow of the exhaust gas. It is characterized by forming each.

[0014]

[Action]

 According to the first aspect of the present invention, portions of both sides of the metal honeycomb carrier facing each other in a predetermined layer of the core part are insulated by insulating ceramic strips, and between the electrodes at both ends of the metal honeycomb carrier. An electric current is applied to the metallic honeycomb carrier along its longitudinal direction to heat the core portion.

Since the diameter of the ceramic spherical body is larger than the size between the portions of the metal honeycomb carrier facing each other in each layer of the core portion, the ceramic spherical body has a predetermined diameter of the core portion. Are held under pressure between the portions on both sides of the metal honeycomb carrier facing each other in the layer.

The metal honeycomb carrier thermally expands and contracts, but since the ceramic spherical body is only sandwiched between the parts on both sides of the metal honeycomb carrier which are adjacent and face each other in each layer of the core part, the metal honeycomb carrier is made of metal. The honeycomb carrier is free to undergo thermal expansion / contraction.

The dimensional change of the metallic honeycomb carrier is not restricted by the ceramic spherical body. In the device according to the second aspect, the same action occurs.

[0018]

【Example】

 An embodiment of the present invention will be described below with reference to the drawings. In this embodiment, the present invention is applied to a catalytic converter for automobiles.

An electrothermal catalyst carrier according to a first embodiment of the present invention will be described with reference to FIGS. 1 to 3. In FIG. 2, reference numeral 1 indicates a metal catalyst converter, and this metal catalyst converter 1 has a cylindrical container 2 in which metal shells 2A, 2A are aligned in the middle, and the center of the cylindrical container 2 is shown. The electrothermal catalyst carrier 3 shown in FIG. 1 is housed in the portion. 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 obtained by folding a single strip-shaped metal honeycomb carrier 5 in a serpentine manner in multiple stages. The metal honeycomb carrier 5 is formed by stacking a metal corrugated plate 5A and a flat plate 5B.

As shown in FIGS. 1 and 3, an insulating ceramic layer 7 is formed between the portions of the core portion 6 of the honeycomb carrier 5 made of metal and facing each other in each layer. It is layered.

The insulating ceramic layer 7 includes a plurality of ceramic spherical bodies 8 having a dimension L larger than the dimension L 1 between both portions of the metal honeycomb carrier 5 of the core portion 6 which face each other and are adjacent to each other. It is sandwiched in the pressed state. The ceramic spherical body 8 includes not only a perfect sphere but also an elliptical sphere or the like.

Then, the portions of the metal honeycomb carrier 5 that are opposed to and adjacent to each other between the layers of the core portion 6 are insulated via the insulating ceramic layer 7. Further, electrodes 9 and 10 are provided at both ends of the metallic honeycomb carrier 5, and the electrodes 9 and 10 penetrate the cylindrical insulating material 4 and the cylindrical container 2 and project to the outside of the cylindrical container 2. , Are connected via a power source (not shown). Insulating colors 9A and 10A are provided on the outer circumferences of the electrodes 9 and 10, respectively, to insulate the shell 2 from the electrodes 9 and 10.

When a voltage is applied between the electrodes 9 and 10, 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, but the predetermined step portion is not formed. The portion 5C of the metal honeycomb carrier 5 is insulated from the portion 5D of the other step by the insulating ceramic layer 7. Therefore, the portion 5C of the predetermined step of the metallic honeycomb carrier 5 does not have to be adjacent to the other adjacent portion 5C even if there is no insulating plate as in the conventional example. A current short circuit is prevented with respect to the step portion 5D. Therefore, the electric current flows in the meandering shape along the longitudinal direction of the metallic honeycomb carrier 5 folded in the meandering shape at the electrodes 9 and 10 as shown by the arrow Y. Due to the resistance heating of this current, the core portion 10 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 burned. Can be fully performed. Then, when the temperature of the exhaust gas becomes high, the supply of current between the electrodes 9 and 10 is stopped.

Since the diameter of the ceramic spherical body 8 is larger than the distance between the portions of the metal honeycomb carrier 5 that face each other in each layer of the core portion 6, the ceramic spherical body 8 is The core portion 6 is held in a pressurized state between the portions on both sides of the metal honeycomb carrier 5 that are opposed to and adjacent to each other in a predetermined layer.

Further, although the metallic honeycomb carrier 5 thermally expands and contracts due to the temperature change of the exhaust gas, the ceramic spherical bodies 8 of the metallic honeycomb carrier 5 adjacent to each other in each layer of the core portion 6 face each other. Since the metal honeycomb carrier 5 is only sandwiched between the portions on both sides, the metal honeycomb carrier 5 is free to thermally expand and contract. The dimensional change of the metallic honeycomb carrier 5 is not restricted by the ceramic spherical body 8.

According to the above-mentioned configuration, the metal honeycomb carrier 5 thermally expands and contracts particularly in the longitudinal direction due to the change in the exhaust gas temperature, but the core portions 6 of the adjacent metal in each layer are opposed to each other. Since the insulating ceramic layer 7 is formed between the portions of the honeycomb carrier 5 made of ceramics in a state of being pressed with a plurality of ceramic spherical bodies 8 having a diameter larger than those dimensions, the insulating ceramic layers 7 are formed in layers. The ceramic spherical body 8 is sandwiched in a state of being pressed between the portions on both sides of the metal honeycomb carrier 5 which are opposed to each other, and the thermal expansion coefficient of the metal honeycomb carrier 5 and the ceramic spherical body 8 is The problem of peeling due to the difference can be avoided, the ceramic spherical body 8 can be reliably held, and the insulating ceramic layer 7 can be prevented from falling off from the metal honeycomb carrier 5.

Further, unlike the conventional example, the insulating plate provided between the respective layers of the metallic honeycomb carrier is not required, and inconveniences such as displacement and dropout of the insulating plate can be prevented.

In this embodiment, the core portion 6 is formed by folding the metal honeycomb carrier 5 in a meandering manner in multiple stages. By winding the metal honeycomb carrier 5, the insulating ceramic layer is formed. The present invention can be applied to an electrothermal catalyst carrier in which 7 is layered.

Further, in the present embodiment, the surface of the metal honeycomb carrier 5 is flat, but it is also possible to form a concave portion for the ceramic spherical body 8 to lock on the surface.

FIG. 4 shows an electrothermal catalyst carrier according to a second embodiment of the present invention. The second embodiment has the same structure as that of the first embodiment, and only the difference will be described. The description of the same components as those of the first embodiment will be omitted.

As shown in the figure, between the portions of the core portion 6 of the metal honeycomb carrier 5 which are adjacent and face each other in each layer, a ceramic rod-shaped body having a diameter larger than the dimension between the portions. Insulating ceramic layers 12 are formed by sandwiching 11 in the direction perpendicular to the flow of exhaust gas.

According to the second embodiment, the same effect as the first embodiment can be obtained. The present invention is not limited to the above embodiment, but can be widely applied to a catalytic converter of an internal combustion engine.

[0035]

[Effect of the device]

 As described above, according to the invention of claim 1, the metal honeycomb carrier thermally expands / contracts particularly in the longitudinal direction due to the change of the exhaust temperature, but the metal honeycomb carrier faces each other in each layer of the core part. The ceramic spheres are sandwiched between the adjacent metal honeycomb carrier parts in a pressed state. By avoiding this, the ceramic spherical body can be reliably held, and the insulating ceramic layer can be prevented from falling off from the metal honeycomb carrier.

Further, unlike the conventional example, it is possible to eliminate the need for an insulating plate provided between the layers of the metal honeycomb carrier, and thus to prevent problems such as displacement and dropout of the insulating plate. Play.

[Brief description of drawings]

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

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

3 is an enlarged view of an essential part near the insulating ceramic layer of the core part of FIG.

FIG. 4 is a sectional view of a metal catalytic converter according to a second embodiment of the present invention.

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 6 Core Part 7 Insulating Ceramic Layer 8 Ceramic Spherical Body 9 Electrode 10 Electrode

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI technical display location F01N 3/28 301 P

Claims (2)

[Scope of utility model registration request] 1. A single strip-shaped metal honeycomb carrier (5) having electrodes (9, 10) at both ends is folded in multiple stages along the longitudinal direction or is wound in multiple layers. Forming a core portion (6) formed by layering the metal honeycomb carrier (5), and extending the metal honeycomb carrier (5) between the electrodes (9, 10) at both ends of the metal honeycomb carrier (5). In an electrothermal catalyst carrier that heats the core part (6) by passing an electric current along a direction, the core part (6) is sandwiched between the portions of the metal honeycomb carrier (5) adjacent to each other in each layer. Ceramic spherical body with a diameter larger than that dimension between parts (8)
An electrothermal catalyst carrier comprising an insulating ceramic layer (7) formed by sandwiching a plurality of electrodes. 2. A metal honeycomb carrier (5) is obtained by folding a single strip-shaped metal honeycomb carrier (5) having electrodes (9, 10) at both ends thereof in multiple stages along the longitudinal direction. A core portion (6) is formed, and a current is applied to the metallic honeycomb carrier (5) along the longitudinal direction between the electrodes (9, 10) at both ends of the metallic honeycomb carrier (5). In the electrothermal catalyst carrier for heating the core portion (6) by means of the core portion (6), between the portions of the metal honeycomb carrier (5) facing each other in each layer, the distance between the portions is smaller than the dimension thereof. Ceramic rods with large diameter (1
An electrothermal catalyst carrier characterized in that an insulating ceramic layer (12) is formed by sandwiching 1) in a direction perpendicular to the flow of exhaust gas.