JPH0596424U - Electrothermal catalyst carrier electrode mounting structure - Google Patents

Abstract

(57) [Abstract] [Object] The present invention relates to improvement of an electrode mounting structure in an electrothermal catalyst carrier of a metal catalytic converter mounted in an exhaust system of an internal combustion engine, particularly in an exhaust system of an automobile. It is an object of the present invention to prevent exhaust gas from leaking through a gap between a rod-shaped electrode and a hole of a ceramic cylindrical member mounted inside. A connecting portion 6 with which a base end portion 9A of a rod-shaped electrode 9 contacts is formed on a side surface of a metal catalyst carrier 3, and a metal plate member 10 is integrally provided on the rod-shaped electrode 9 via an insulating member 8 to form an electrode. The block 7 is formed, and the peripheral edge 10A of the metal plate member 10 of the electrode block 7 is placed in a container in a state where the base end portion 9A of the rod-shaped electrode 9 of the electrode block 7 is in contact with the connecting portion 6 of the metal catalyst carrier 3. 2 is welded on top.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an improvement of an electrode mounting structure in an electrothermal catalyst carrier of a metal catalytic converter mounted on an exhaust system of an internal combustion engine, particularly an exhaust system of an automobile.

[0002]

[Prior Art]

 In an exhaust system of an internal combustion engine, for example, an exhaust system of an automobile, it is required that the catalyst carrier in the metal catalytic converter be rapidly heated and warmed at the start of engine operation. For example, in a metal catalytic converter, an electrothermal catalyst carrier that carries an electric current and resistance heating is housed in a metal container, and this electrothermal catalytic carrier requires a pair of electrodes as terminals for passing an electric current. Become. The electrode is insulated from a metal container that houses the metal catalyst carrier, and an electrothermal catalyst carrier having such an electrode mounting structure is disclosed in, for example, Japanese Patent Laid-Open No. 3-245851 (shown in FIG. 3).

In the figure, a metal catalyst carrier 103 is housed in a metal cylindrical container 101 via a ceramic mat 102. Rod-shaped electrodes 104 and 105 are fixedly provided on both sides of the metal catalyst carrier 103, and the rod-shaped electrodes 104 and 105 penetrate the mounting holes of the ceramic mat 102 and the cylindrical container 101 to project to the outside of the cylindrical container 101 to form a rod-shaped electrode. The electrodes 104 and 105 are insulated from the mounting holes of the cylindrical container 101 via insulating bushes 106, respectively.

Further, as an electrode mounting structure of this type of electrothermal catalyst carrier, one shown in FIG. 4 is known. In the figure, a metallic catalyst carrier 112 is housed in a metallic cylindrical container 111, and a rod-shaped electrode 113 is fixed to the metallic catalyst carrier 112 so as to project.

Further, a cap member 114 is attached by welding around the attachment hole 111 A of the cylindrical container 111, and a ceramic cylindrical member 115 is enclosed in the cap member 114. It is inserted into the cylindrical container 111 by penetrating the mounting hole 111 A of the cylindrical container 111.

Then, the metal catalyst carrier 112, to which the rod-shaped electrode 113 is fixedly mounted, is assembled in the cylindrical container 111 by penetrating the rod-shaped electrode 113 through the hole 115A of the ceramic cylindrical member 115.

[0007]

[Problems to be solved by the device]

 However, in the conventional electrode mounting structure of the electrothermal catalyst carrier, the rod-shaped electrode 113 integrated with the metal catalyst carrier 112 is provided in the hole portion 115A of the ceramic cylindrical member 115 provided in the mounting hole 111A of the cylindrical container 111. Since the structure is such that the metal catalyst carrier 112 is inserted into the cylindrical container 111 by inserting, the position of the rod-shaped electrode 113 cannot be adjusted in the left-right direction. Therefore, in consideration of the possibility that the position of the rod-shaped electrode 113 does not coincide with the position of the mounting hole 111A of the cylindrical container 111 due to an assembly error, the hole diameter of the hole portion 115A of the ceramic cylindrical member 115 should be increased. As a result, a gap is created between the hole 115A of the ceramic cylindrical member 115 and the rod-shaped electrode 113, and the exhaust gas may leak from this gap. If the hole diameter of the hole 115A of the ceramic cylindrical member 115 is reduced so that there is no gap, if there is an assembly error, the rod-shaped electrode 113 integrated with the metal catalyst carrier 112 is made of ceramic. It becomes difficult to insert into the hole 115A of the cylindrical member 115.

That is, it is difficult to absorb the displacement (assembly error) between the position of the rod-shaped electrode 113 integrated with the metallic catalyst carrier 112 and the position of the mounting hole 111A of the cylindrical container 111. The present invention has been made to solve the above-described problems, and its purpose is to exhaust gas from the gap between the rod-shaped electrode and the hole of the ceramic cylindrical member mounted in the mounting hole of the cylindrical container. An object is to provide an electrode attachment structure for an electrothermal catalyst carrier that can prevent the leakage of electricity.

[0009]

According to the present invention, a metal catalyst carrier is housed in a metal container, and a rod-shaped electrode that penetrates a mounting hole of a container and projects outside the container is housed in the metal catalyst carrier. In the attached electrothermal catalyst carrier, a connection part with which the base end of the rod-shaped electrode contacts is formed on the side surface of the metal catalyst carrier, and the metal plate is integrally provided on the rod-shaped electrode via an insulating member to form an electrode block. It is characterized in that the peripheral edge of the metal plate material of the electrode block is welded onto the container in a state where the base end portion of the rod-shaped electrode of the electrode block is in contact with the connection portion of the metal catalyst carrier. To do.

[0010]

[Action]

 In the present invention, the rod-shaped electrode of the electrode block is inserted into the container by penetrating through the mounting hole of the container, but the base end of the rod-shaped electrode of the electrode block contacts the connection part of the metal catalyst carrier. The mounting position of the electrode block is adjusted in the horizontal direction with respect to the mounting hole of the container.

Then, the peripheral edge of the metal plate material of the electrode block whose mounting position is determined is welded onto the container. Since the electrode block is attached to the container in this manner, there is no room for a gap between the rod-shaped electrode and the insulating member in the conventional example, and gas leakage is prevented.

Further, the electric current flowing through the metal catalyst carrier is transmitted to the base end portion of the rod-shaped electrode through the connecting portion.

[0013]

【Example】

 An embodiment of the present invention will be described below with reference to the drawings. An electrode mounting structure for an electrothermal catalyst carrier according to an embodiment of the present invention will be described with reference to FIGS.

In the figure, reference numeral 1 indicates a metal catalyst converter, and this metal catalyst converter 1 has a metallic cylindrical container 2, and a metallic catalyst carrier 3 is housed in the central portion of the cylindrical container 2. Has been done. The metal catalyst carrier 3 is formed by stacking a single corrugated plate and a flat plate on a strip, and is folded in a zigzag manner in multiple stages. Ceramic fiber cloth is placed between the layers of the metal catalyst carrier 3. Insulating members made of, for example, are arranged in layers.

Between the inner wall surface of the cylindrical container 2 and the outer surface of the metal catalyst carrier 3, the ceramic mats 4A, 4A and the washer wire meshes 4B, 4B and the ceramic mats 4A, 4A are arranged. A front ceramic tubular holding member 5A and a rear ceramic tubular holding member 5B located inside are provided.

On both side surfaces of the metal catalyst carrier 3, there are fixedly provided connecting portions each of which is composed of a short cylindrical boss portion 6 in which an internal thread 6A is cut on the inner peripheral wall surface. Reference numeral 7 denotes an electrode block. In this electrode block 7, a rod-shaped electrode 9 is integrally embedded in an inner peripheral surface of an insulating member made of a ceramic cylindrical holding member 8 and a circular metal plate member 10 is formed on an outer peripheral surface. The rod-shaped electrode 9 penetrates the ceramic cylindrical holding member 8 by being embedded integrally.

Then, a mounting hole 11 is bored in the cylindrical container 2, and the rod-shaped electrode 9 and the ceramic cylindrical holding member 8 penetrate through the mounting hole 11 and are inserted into the cylindrical container 2, In the state where the base end portion formed of the male screw 9A of the rod-shaped electrode 9 is screwed into the female screw 6A of the boss portion 6 of the catalyst carrier 3, the peripheral end edge 10A of the metal plate member 10 of the electrode block 7 is the cylindrical container 2 It is welded on.

The pair of electrodes 9, 9 are located at opposite sides, are insulated from the cylindrical container 2 via the ceramic cylindrical holding member 8 and project from the cylindrical container 2, and are not shown. It is connected via a power supply.

Therefore, in this embodiment, first, the metallic catalyst carrier 3 having the boss portion 6 fixed thereto is housed in the cylindrical container 3. Next, since the rod-shaped electrode 9 of the electrode block 7 is inserted into the tubular container 2 by penetrating the attachment hole 11 of the tubular container 2, the position of the rod-shaped electrode 9 and the attachment hole 11 are different from each other as in the conventional example. The mounting position of the electrode block 7 is such that the male screw 9A of the rod-shaped electrode 9 of the electrode block 7 is screwed into the boss portion 6 of the metal catalyst carrier 3 without making the position coincidence problem. The mounting hole 11 is adjusted in the left-right direction. The male screw 9A of the rod-shaped electrode 9 is screwed into the female screw 6A of the boss portion 6 and tightened.

Further, the peripheral edge 10A of the metal plate material 10 of the electrode block 7 whose attachment position is fixed is welded onto the cylindrical container 2. Then, the current flowing through the metallic catalyst carrier 3 is transmitted to the rod-shaped electrode 9 via the boss portion 6. At this time, since the male screw 9A of the rod-shaped electrode 9 is screwed into the female screw 6A of the boss portion 6, the contact area is increased, and melting damage due to local heat generation during conduction is prevented. At the start of engine operation, an electric current flows in a meandering manner along the longitudinal direction of the folded metallic catalyst carrier 3 between both electrodes 9, 9. By the resistance heating of this electric current, the metallic catalyst carrier 3 is wholly heated and rapidly heated.

According to the above configuration, the mounting position of the electrode block 7 is such that the male screw 9A of the rod-shaped electrode 9 of the electrode block 7 is screwed into contact with the boss portion 6 of the metal catalyst carrier 3. Can be adjusted in the left-right direction with respect to the mounting hole 11 of the cylindrical container 2.

Therefore, unlike the conventional example, the problem of assembly in which the position of the rod-shaped electrode 9 and the position of the mounting hole 11 of the cylindrical container 2 are matched is avoided, and the position of the electrode block 7 is set to the metal catalyst. After adjusting according to the boss portion 6 of the carrier 3, the electrode block 7 can be attached to the cylindrical container 2 to absorb an assembly error. That is, since the rod-shaped electrode 9 and the ceramic cylindrical holding member 8 are integrated, and the peripheral edge 10A of the metal plate material 10 is welded onto the cylindrical container 2, a gap is produced in the conventional example. There is no room, and it is possible to prevent the exhaust gas from leaking from around the rod-shaped electrode 9.

Further, since the electrode block 7 may be attached to the cylindrical container 2 by aligning the rod-shaped electrode 9 with the boss portion 6 integrated with the metal catalyst carrier 3, the metal catalyst carrier having the rod-shaped electrode 9 may be attached. It is possible to improve the assemblability with respect to the cylindrical container 2 of No. 3.

In this embodiment, since the base end of the rod-shaped electrode 9 is brought into contact with the connecting portion of the metallic catalyst carrier 3, the connecting portion of the metallic catalyst carrier 3 is constituted by the boss portion 6 and The base end portion of the electrode 9 is formed of a male screw 9A, and the female screw 6A of the boss portion 6 is screwed with the male screw 9A of the rod-shaped electrode 9. However, the present invention is not limited to this mode, and for example, a rod-shaped electrode It is also possible to configure the base end portion of 9 as a mortar-shaped recess and the connection portion of the metal catalyst carrier as a triangular pyramid shape that matches the mortar-shaped recess, or the base end portion of the rod-shaped electrode 9 In addition to being composed of a plurality of projecting pieces, the connecting portion of the metal catalyst carrier 3 may be composed of a plurality of contactors that are in surface contact with the side surfaces of the plurality of projecting pieces.

In the present embodiment, the male screw 9A of the rod-shaped electrode 9 of the electrode block 7 is preliminarily wrapped with the sheet-shaped brazing material, and the male screw 9A is screwed onto the female screw 6A of the boss portion 6. Alternatively, the brazing material can be melted by heat treatment to ensure contact.

Furthermore, in the present embodiment, an example in which the present invention is applied to a catalytic converter for an automobile has been described, but the present invention is not limited to the above-mentioned embodiment and can be widely applied to a catalytic converter of an internal combustion engine.

[0027]

[Effect of the device]

 As described above, according to the present invention, the mounting position of the electrode block is set to the mounting hole of the container so that the base end portion of the rod-shaped electrode of the electrode block contacts the connection portion of the metal catalyst carrier. It can be adjusted in the left-right direction.

That is, the problem of assembling the position of the rod-shaped electrode and the position of the mounting hole of the container is avoided, and the position of the electrode block is adjusted according to the connecting portion of the metal catalyst carrier, and then the electrode block is adjusted. Can be attached to the container to absorb the assembly error. Therefore, there is no room for a gap between the rod-shaped electrode and the insulating member in the conventional example, and the leakage of exhaust gas from the rod-shaped electrode can be prevented.

Further, since the electrode block may be attached to the container by aligning the rod-shaped electrode with the connecting portion of the metal catalyst carrier, it is possible to improve the assemblability of the metal catalyst carrier having the rod-shaped electrode with respect to the container. Play.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing an electrothermal catalyst carrier according to an embodiment of the present invention.

FIG. 2 is an enlarged sectional view of an essential part of the electrode mounting structure of the electrothermal catalyst carrier.

FIG. 3 is a cross-sectional view showing a conventional electrode mounting structure for an electrothermal catalyst carrier.

FIG. 4 is an enlarged sectional view of an essential part showing another conventional electrode mounting structure for an electrothermal catalyst carrier.

[Explanation of symbols]

 2 Cylindrical container 3 Metal catalyst carrier 6 Boss part (connection part) 7 Electrode block 8 Ceramic cylindrical holding member (insulating member) 9 Rod electrode 9A Male screw (base end) 10 Metal plate material 10A Peripheral edge 11 Mounting hole

Claims (1)

[Scope of utility model registration request] 1. A metal catalyst carrier (3) is housed in a metal container (2), and a mounting hole (11) for the container (2) is attached to the metal catalyst carrier (3).
In a electrothermal catalyst carrier having a rod-shaped electrode (9) penetrating through the container and protruding to the outside of the container (2), the base end portion (9A) of the rod-shaped electrode (9) is provided on the side surface of the metal catalyst carrier (3). A metal plate material (10) is integrally formed on the rod-shaped electrode (9) via an insulating member (8) to form an electrode block (7) by forming a contacting portion (6) in contact with the metal catalyst carrier ( The peripheral edge of the metal plate material (10) of the electrode block (7) with the base end portion (9A) of the rod-shaped electrode (9) of the electrode block (7) being in contact with the connection portion (6) of 3). (10A) is welded onto a container (2), which is an electrode mounting structure for an electrothermal catalyst carrier.