JP2021188562A - Electric heating-type catalyst device - Google Patents

Abstract

To provide an electric heating-type catalyst device which can homogeneously heat a carrier via comb-shaped electrodes.SOLUTION: An electric heating-type catalyst device 1 comprises: a circular columnar carrier 10 at which a metal catalyst is carried; a pair of comb-shaped electrodes 5 having a plurality of wiring parts 51, a connection part 52 and an extension part 54; an underlayer 4 formed at an external peripheral face of the carrier 10, and interposed between the comb-shaped electrodes 5 and the carrier 10; and a fixing layer 6 for fixing the wiring parts 51 to the underlayer 4 by being joined to the underlayer 4 so as to cover a part of the wiring parts 51. A width C1 of the extension part 54 is narrower than a width B1 of the connection part 52 in a direction orthogonal to a width direction D1, and a width-expanded part 53 which is expanded in a width into a trapezoidal shape so as to approximate the width B1 of the connection part 52 from the width C1 of the extension part 54 as progressing toward the connection part 52 from the extension part 54 is formed between the extension part 54 and the connection part 52.SELECTED DRAWING: Figure 3

Description

The present invention relates to an electrically heated catalyst device including at least a carrier on which a catalyst is supported and an electrode attached to the carrier.

Conventionally, an electric heating type catalyst device that is energized and heated in order to purify exhaust gas has been known. For example, an electrically heated catalyst device includes a carrier on which a metal catalyst is supported and a comb-shaped electrode that is fixed to the carrier in order to energize the carrier. Here, the comb-shaped electrode energizes the carrier with a current from an external power source such as a battery, and the carrier is heated by being energized via the comb-shaped electrode to activate the metal catalyst supported on the carrier. do. According to the electric heating type catalyst device, it is possible to effectively purify the exhaust gas by forcibly heating the carrier by energization.

As such an electrically heated catalyst device, for example, in Patent Document 1, a comb-shaped electrode having a plurality of wiring portions extending along the circumferential direction of the carrier is formed on the carrier (on the carrier) via a fixed layer. An electrically heated catalyst device fixed to the base layer) is disclosed. Here, the plurality of wiring portions are connected to the connecting portion on one end side thereof, and a strip-shaped extending portion is formed toward the side opposite to the plurality of wiring portions side with respect to the connecting portion.

International Publication 2013/0384449

However, when fixing the comb-shaped electrode, each wiring is fixed to the base layer in a state where tension is applied to the wiring through the extending portion so that the wiring of the comb-shaped electrode follows the base layer on the peripheral surface of the carrier. However, at this time, the tension of each wiring may be non-uniform, and some wiring may rise from the base layer. As a result, when the floating wiring is fixed to the base layer via the fixing layer, a gap is generated between the base layer and the wiring. As a result, when a comb-shaped electrode of an electrically heated catalyst device is repeatedly energized, cracks may occur locally inside the fixed layer due to the thermal stress associated with the repetition. As a result, in the cracked portion, the carrier may not be energized from the wiring portion through the fixed layer, and the carrier may not be uniformly heated.

Further, when the carrier to which the comb-shaped electrode is fixed is attached to the exhaust pipe or the like, for example, if the extending portion is pulled, the tension of the extending portion is dispersed in each wiring, but the tension of the dispersed wiring is distributed. Acts unevenly. As a result, the wiring and the fixed layer on which relatively high tension acts may be damaged, and the carrier may not be heated uniformly.

The present invention has been made in view of these points, and an object of the present invention is to provide an electrically heated catalyst device capable of uniformly heating a carrier via a comb-shaped electrode.

In view of the above problems, the electrically heated catalyst device according to the present invention is arranged with a columnar carrier on which a metal catalyst is supported at intervals in the axial direction of the carrier, and is arranged along the circumferential direction of the carrier. A strip-shaped extension extending toward the side opposite to the plurality of wiring portions with respect to the connecting portion and the connecting portion connecting one end of the plurality of wiring portions. A pair of comb-shaped electrodes provided with a portion, a base layer formed on the outer peripheral surface of the carrier and interposed between the comb-shaped electrode and the carrier, and a part of each wiring portion. An electrically heated catalyst device including a fixed layer for fixing each wiring portion to the base layer by being joined to the base layer, and extending in a direction orthogonal to the axial direction. The width of the portion is narrower than the width of the connecting portion, and between the extending portion and the connecting portion, as the extension progresses from the extending portion to the connecting portion, the width of the extending portion increases to the connecting portion. It is characterized in that a widened portion having a widened width in a trapezoidal shape is formed so as to approach the width of the above.

According to the present invention, between the extending portion and the connecting portion of the comb-shaped electrode, a trapezoidal shape is formed so as to approach the width of the connecting portion from the width of the extending portion as the extension portion progresses to the connecting portion. A widened portion with a wider width is formed. As a result, for example, even if tension acts on the extending portion of the comb-shaped electrode when mounting the electrically heated catalyst device, the tension is dispersed in the width direction at the widening portion, so that the tension is uniformly distributed to each wiring. Can be dispersed. As a result, the carrier can be uniformly heated via the comb-shaped electrode by suppressing damage to the wiring due to tension.

In a more preferable embodiment, the width of the connecting portion and the width of the widening portion on the connecting portion side are the same, and the width of the extending portion and the width of the widening portion on the extending portion side are the same. Are in agreement. According to this aspect, by satisfying the relationship of these widths, the tension acting on the extending portion of the comb-shaped electrode can be uniformly dispersed by each wiring.

As a further preferred embodiment, when the width of the connecting portion is B1 and the length of the widening portion in the direction orthogonal to the width direction of the connecting portion is H1, H1 / B1 is 0.28 to 1. It is in the range of .12. According to this aspect, when H1 / B1 satisfies the range of 0.28 to 1.12, the tension acting on the wiring can be more uniformly dispersed. Here, when H1 / B1 is less than 0.28, the tension dispersion action by the widening portion may not be sufficient, while when H1 / B1 exceeds 1.12, the tension is increased. Not only can the dispersive effect not be expected any more, but also the size of the widened portion becomes large, so that there may be space-like restrictions.

As a more preferable embodiment, an elongated hole extending from the extending portion toward the connecting portion is formed in the center of the widened portion in the width direction. According to this aspect, tension from the extending portion tends to act more in the center of the widening portion in the width direction than in other portions, but by providing a long hole in this portion, the width direction of the widening portion is provided. The tension acting in the center of the can be dispersed.

According to the present invention, the carrier can be uniformly heated via the comb-shaped electrode.

It is a schematic perspective view of the electric heating type catalyst apparatus which concerns on embodiment of this invention. It is sectional drawing of the state which attached the electric heating type catalyst apparatus shown in FIG. 1 to an exhaust pipe. It is a figure which showed the state before bending the comb-shaped electrode of the electric heating type catalyst apparatus shown in FIG. It is a schematic conceptual diagram which showed the molding state of the base layer among the manufacturing methods of the electric heating type catalyst apparatus shown in FIG. It is a schematic conceptual diagram which showed the arrangement state of the electrode in the manufacturing method of the electric heating type catalyst apparatus shown in FIG. It is a schematic conceptual diagram which showed the state before molding of the fixed layer among the manufacturing methods of the electric heating type catalyst apparatus shown in FIG. It is a schematic conceptual diagram which showed the state after molding of the fixed layer among the manufacturing methods of the electric heating type catalyst apparatus shown in FIG. It is a schematic conceptual diagram which showed the state after molding on the comb-shaped electrode in the manufacturing method of the electric heating type catalyst apparatus shown in FIG. It is a top view of the comb-shaped electrode which concerns on Example 1. FIG. It is a top view of the comb-shaped electrode which concerns on Example 2. FIG. It is a top view of the comb-shaped electrode which concerns on Example 3. FIG. It is a top view of the comb-shaped electrode which concerns on Example 4. FIG. It is a top view of the comb-shaped electrode which concerns on Example 5. FIG. It is a top view of the comb-shaped electrode which concerns on Comparative Example 1. FIG. It is a graph of the application distribution of the comb-shaped electrode which concerns on Examples 1-5 and Comparative Example 1. It is a top view of the electrode sheet corresponding to Example 3. FIG. This is the result of measuring the relationship between the position of the wiring of the comb-shaped electrode according to Example 6 and Comparative Example 2 and the size of the gap between the wiring and the base layer.

Hereinafter, the electrically heated catalyst device according to the embodiment of the present invention will be described with reference to FIGS. 1 to 3, and then, with reference to FIGS. 4A to 4E, the electrically heated catalyst shown in FIG. 1 will be described. The manufacturing method of the device will be briefly described.

1. 1. About the electric heating type catalyst device The electric heating type catalyst device 1 is a device provided on an exhaust path of, for example, an automobile or the like and purifies the exhaust gas discharged from the engine. As shown in FIG. 1, the electrically heated catalyst device 1 includes a carrier 10, a base layer 4, a comb-shaped electrode 5, and a fixed layer 6. As shown in FIG. 2, the electrically heated catalyst device 1 is inserted in the exhaust pipe 71 and is held in the exhaust pipe 71 via a holding mat 72 made of ceramics or the like.

1-1. About the carrier 10 As shown in FIG. 1, the carrier 10 is a porous member made of ceramics having a columnar outer diameter, and has a honeycomb structure 10a inside thereof, along the central axis CL of the carrier 10. Exhaust gas can pass through the inside of the carrier 10 due to the plurality of extending holes.

Examples of the ceramics constituting the carrier 10 include a composite material composed of SiC (silicon carbide) particles and Si (silicon) particles, and the ceramics having conductivity are not limited to those obtained. No. Further, a metal catalyst such as platinum, palladium, or rhodium is supported on the wall surface of the carrier 10 that forms the honeycomb structure 10a.

On the outer peripheral surface 10b of the carrier 10, a base layer 4 for fixing the comb-shaped electrode 5 described later to the carrier 10 is formed. The base layer 4 is interposed between the comb-shaped electrode 5 and the carrier 10, and the pair of comb-shaped electrodes 5 are fixed via the fixing layer 6 described later.

In the present embodiment, the base layer 4 is a base layer for fixing each comb-shaped electrode 5, and is located on the opposite side of the outer peripheral surface 10b of the carrier 10 with the central axis CL interposed therebetween (the carrier 10 is the central axis). Two are formed at a position rotated by approximately 180 ° around the CL). A first base layer 4a formed on the outer peripheral surface 10b of the carrier 10 and a second base layer 4b formed on the first base layer 4a are provided. The first base layer 4a is made of a ceramic material having conductivity, and in the present embodiment, is a layer of a composite material composed of SiC (silicon carbide) particles and Si (silicon) particles.

Here, it is more preferable that the ratio of the SiC particles contained in the carrier 10 is higher than the ratio of the SiC particles constituting the first base layer 4a. As a result, the resistance value of the carrier 10 can be made higher than that of the first base layer 4a, and the heat generation property of the carrier 10 can be enhanced.

On the premise of such a relationship, when the total amount of SiC (silicon carbide) particles and Si (silicon) particles constituting the carrier 10 is 100%, the amount of SiC (silicon carbide) is 65% by volume to 75% by volume. Is preferable. On the other hand, when the total amount of SiC (silicon carbide) particles and Si (silicon) particles constituting the first base layer 4a is 100% by volume, the amount of SiC (silicon carbide) is 55% by volume to 65% by volume. % Is preferable.

1-2. About the base layer 4 The second base layer 4b is a layer in which oxide mineral particles made of oxide minerals are dispersed and the oxide mineral particles are connected by a metal matrix. Specifically, examples of the metal matrix include NiCr alloys and MCrAlY alloys (where M is at least one of Fe, Co, and Ni). The oxidized mineral contains _{an oxide such as SiO 2} or Al ₂ O ₃ as a main component, and is preferably composed of, for example, bentonite, mica, or a mixture thereof. In the present embodiment, the second base layer 4b is a layer obtained by spraying a mixed powder of a mixture of NiCr alloy particles serving as a metal matrix and bentonite particles serving as oxide mineral particles on the surface of the first base layer 4a.

In the present embodiment, the resistance values of the second base layer 4b, the resistance value of the first base layer 4a, and the resistance value of the carrier 10 increase in this order. Therefore, among these, the carrier 10 has the highest resistance value, so that the carrier 10 is easily heated when energized. Further, by lowering the resistance value of the second base layer 4b to be lower than the resistance value of the first base layer 4a, the current from the comb-shaped electrode 5 in the second base layer 4b can easily flow in the circumferential direction D2 of the carrier 10. can do. The first base layer 4a is a layer adjusted by the second base layer 4b as an intermediate resistance value so that the current flowing in the circumferential direction D2 of the carrier 10 (see FIG. 4A and the like) flows through the carrier 10. It has become.

1-3. About the comb-shaped electrode 5 In the present embodiment, as shown in FIG. 1, the electric heating type catalyst device 1 is a pair of comb-shaped electrodes 5 made of a conductive metal such as an Fe—Cr alloy (for example, stainless steel). It is equipped with 5. The pair of comb-shaped electrodes 5 and 5 are arranged at positions opposite to the outer peripheral surface 10b of the carrier 10 (positions in which the carrier 10 is rotated by 180 ° around the central axis CL) with the central axis CL interposed therebetween. ..

Each comb-shaped electrode 5 includes a plurality of wiring portions 51, a connecting portion 52, a widening portion 53, and an extending portion 54. The widening portion 53, which is a characteristic point of the comb-shaped electrode 5, will be described later.

The plurality of wiring portions 51 are arranged (paralleled) at intervals in the axial direction D1 of the carrier 10, and each wiring portion 51 extends along the circumferential direction D2 of the carrier 10. The connecting portion 52 is formed between the wiring portions 51 located at both ends in the axial direction D, and connects one ends of the plurality of wiring portions 51. In the present embodiment, the connecting portion 52 has a rectangular shape, and the width B1 of the connecting portion 52 along the axial direction D1 is the same. In the present embodiment, the connecting portion 52 has a rectangular shape, but the corner portion on the extending portion 54 side may be rounded.

As shown in FIG. 3, in the state before the comb-shaped electrode 5 is bent, the extending portion 54 extends toward the connecting portion 52 toward the side opposite to the plurality of wiring portions 51 side. In the present embodiment, the extending portion 54 has a band shape, and the width C1 of the extending portion 54 is narrower than the width B1 of the connecting portion 52 in the direction orthogonal to the axial direction D1. The extending portion 54 is formed with a through hole 55a for connection, which is electrically connected to a terminal of a power supply (not shown).

1-4. About the fixed layer 6 As shown in FIGS. 1 to 3, the fixed layer 6 is joined to the base layer 4 so as to cover a part of each wiring portion 51 on both sides of each wiring portion 51. It is fixed to the base layer 4. That is, in the present embodiment, the wiring portion 51 is fixed to the base layer 4 (second base layer 4b) via the fixed layer 6. As shown in FIGS. 1 and 3, the plurality of fixing layers 6 for fixing each comb-shaped electrode 5 are arranged in a staggered manner along the circumferential direction D2. The fixed layers 6 may be arranged in parallel in a straight line. The fixed layer 6 is made of the material exemplified by the second base layer 4b, and may be made of the same material as the second base layer 4b in the present embodiment.

Here, the ratio of the oxide mineral (particles) such as bentonite contained in the second base layer 4b and the fixed layer 6 to the metal (matrix) such as NiCr alloy is the oxide mineral (particles) with respect to the total amount thereof. ) Is preferably 55 to 70% by volume. Here, the content ratio of the metal (matrix) in the fixed layer 6 is preferably smaller than that in the second base layer 4b. As a result, the coefficient of thermal expansion of the fixed layer 6 can be brought close to the coefficient of thermal expansion of the wiring portion 51, and the thermal stress acting on the fixed layer 6 due to the thermal shrinkage of the wiring portion 51 can be reduced.

Further, the fixed layer 6 has a rectangular shape when the outer peripheral surface 10b of the carrier 10 is viewed from a direction orthogonal to the central axis CL of the carrier 10 along the longitudinal direction D1. In the present embodiment, the fixed layer 6 has a square shape, but may have a rectangular shape.

1-5. About the widening portion 53 of the comb-shaped electrode 5 The widening portion 53 of the comb-shaped electrode 5 is formed between the extending portion 54 and the connecting portion 52. The widening portion 53 has a trapezoidal width so as to approach the width B1 of the connecting portion 52 from the width of the extending portion 54 as it advances from the extending portion 54 to the connecting portion 52. As a result, even if tension acts on the extending portion 54 of the comb-shaped electrode 5 when the electrically heated catalyst device 1 is attached, the tension is dispersed in the widening portion 53 in the width direction of the comb-shaped electrode 5. Therefore, it can be uniformly dispersed in each wiring portion 51. As a result, the carrier 10 can be uniformly heated via the comb-shaped electrode 5 by suppressing damage to the wiring portion 51 due to tension.

Further, in the present embodiment, the width B1 of the connecting portion 52 and the width of the widening portion 53 on the connecting portion 52 side are the same, and the width C1 of the extending portion 54 and the widening portion 53 on the extending portion 54 side Matches the width. By satisfying these width relationships, the side side of the connecting portion 52 and the hypotenuse of the trapezoidal shape of the widening portion 53 are continuously formed without a step, and the side side of the extending portion 54 and the trapezoidal shape of the widening portion 53 are formed. The hypotenuse of is continuously formed without a step. In this way, the tension acting on the extending portion 54 of the comb-shaped electrode 5 can be uniformly dispersed by each wiring portion 51. Further, the angle formed by the base of the trapezoidal widening portion 53 and the hypotenuse is preferably 45 ° or more. As a result, the force from the extending portion 54 can be dispersed and acted on all the wiring portions 51.

Further, in the present embodiment, when the width of the connecting portion 52 is B1 and the length of the widening portion 53 in the direction orthogonal to the width direction of the connecting portion 52 is H1, H1 / B1 is 0.28 to 1. It is in the range of .12. As is clear from the analysis results described later, when H1 / B1 satisfies the range of 0.28 to 1.12, the tension acting on the wiring portion 51 can be more uniformly dispersed. Here, when H1 / B1 is less than 0.28, the tension dispersion action by the widening portion 53 may not be sufficient, while when H1 / B1 exceeds 1.12, the tension may not be sufficient. Not only can the dispersal effect of the above be not expected any more, but also the size of the widening portion 53 becomes large, so that there may be space-like restrictions.

Further, in the present embodiment, a long hole 53a extending from the extending portion 54 toward the connecting portion 52 is formed in the center of the widening portion 53 in the width direction. The elongated hole 53a may be formed only in the widening portion 53, and may extend to, for example, one or both of the connecting portion 52 and the extending portion 54. At the center of the widening portion 53 in the width direction, the tension from the extending portion 54 tends to act more than other parts, but by providing the elongated hole 53a in this portion, the center of the widening portion 53 in the width direction. The tension acting on the can be dispersed.

As shown in FIG. 3, the comb-shaped electrode 5 fixed to the base layer 4 is bent at the connecting portion 52 along the width direction (axial direction D1), and the boundary line between the widening portion 53 and the extending portion 54. It is further bent at. The tip end side portion of the extending portion 54 is inserted into the power supply box 73 and connected to a terminal (not shown) on the power supply side.

2. 2. About the manufacturing method of the electric heating type catalyst device 1 The manufacturing method of the electric heating type catalyst device 1 shown in FIG. 1 will be described below with reference to FIGS. 4A to 4E.

2-1. Regarding the Step of Forming the Underlayer 4 First, as shown in FIG. 4A, the underlayer 4 is formed on the outer peripheral surface 10b of the carrier 10 made of ceramics. In the step of molding the base layer 4, a pair of base layers 4 and 4 are molded. Specifically, first, a carrier 10 on which the above-mentioned metal catalyst is supported is prepared, and SiC (silicon carbide) particles and Si (silicon) particles are dispersed on the outer peripheral surface 10b of the carrier 10 with a dispersion medium. The first base layer 4a and 4a are formed by applying a material and firing the material. Here, the paste material may be applied by screen printing. After this, a metal catalyst is supported.

Next, a metal masking material (not shown) having openings corresponding to the shapes of the second base layers 4b and 4b is arranged on the first base layers 4a and 4a. Next, a powder obtained by mixing NiCr alloy particles and bentonite particles is sprayed toward this opening by spraying such as gas frame spraying or plasma spraying to melt the NiCr alloy, and the second base layer 4b, Mold 4b.

2-2. Regarding the step of arranging the electrode sheet 50 on the base layer 4, next, as shown in FIG. 4B, a plurality of wiring portions 51 are formed so that the plurality of wiring portions 51 extend along the circumferential direction D2 of the carrier 10. An electrode sheet 50 including the comb-shaped electrode 5 is arranged on the surface of the base layer 4.

Here, the electrode sheet 50 will be described. The electrode sheet 50 is a metal sheet having conductivity and flexibility such as Fe—Cr alloy (for example, stainless steel). The electrode sheet 50 has the following structure and is molded by face-to-face molding or the like. The electrode sheet 50 has a plurality of wiring portions 51 arranged at intervals, a first connecting portion 52A that connects one end of the plurality of wiring portions 51, and a second connecting portion that connects the other ends of the plurality of wiring portions 51. It is provided with a portion 52B. The electrode sheet 50 has a strip-shaped first extending portion 54A extending on the side opposite to the plurality of wiring portions 51 side with respect to the first connecting portion 52A, and a plurality of wiring portions 51 with respect to the first connecting portion 52A. It is provided with a band-shaped second extending portion 54B extending on the side opposite to the side.

The width of the first extending portion 54A is narrower than the width of the first connecting portion 52A, and the width of the second extending portion 54B is narrower than the width of the second connecting portion 52B. Between the first extending portion 54A and the first connecting portion 52A, the width of the first connecting portion 52A from the width of the first extending portion 54A as the first extending portion 54A progresses to the first connecting portion 52A. A first widening portion 53A having a trapezoidal width is formed so as to approach. Further, between the second extending portion 54B and the second connecting portion 52B, as the second extending portion 54B proceeds to the second connecting portion 52B, the width of the second extending portion 54B increases to the second connecting portion 52B. A second widening portion 53B having a trapezoidal width is formed so as to approach the width of the above.

When the electrode sheet 50 having such a structure is arranged on the surface of the base layer 4, the plurality of wiring portions 51 are attached to the carrier 10 while pulling the electrode sheet 50 so that tension is applied to the plurality of wiring portions 51. It is made to imitate the surface of the base layer 4 along the circumferential direction D2. Specifically, while pulling the first extending portion 54A and the second extending portion 54B in a direction away from each other, the plurality of wiring portions 51 are curved so as to imitate the surface of the base layer 4.

Here, the comb-shaped electrode 5 included in the electrode sheet 50 is a wiring portion 51, a first connecting portion 52A, a first widening portion 53A, and a first extending portion 54A. The first connecting portion 52A corresponds to the connecting portion 52 of the comb-shaped electrode 5, the first widening portion 53A corresponds to the widening portion 53 of the comb-shaped electrode 5, and the first extending portion 54A corresponds to the extending portion 54. Corresponds to. Note that FIG. 7 shows a plan view of the electrode sheet 50 used in the following examples.

As shown in the figure, since the first and second widening portions 53A and 53B are formed on the electrode sheet 50, a plurality of electrode sheets 50 are pulled from both sides so that tension is applied to the plurality of wiring portions 51. When the wiring portion 51 of the above is made to follow the surface of the base layer 4 along the circumferential direction of the carrier 10, the tension is uniformly distributed to the plurality of wiring portions 51. As a result, the fixed layer 6 can be joined to the base layer 4 in a state where each wiring portion 51 is prevented from floating from the base layer 4 and the plurality of wiring portions 51 are made to imitate the surface of the base layer 4. As a result, it is possible to suppress the generation of a gap between the base layer 4 and the wiring portion 51, and even when a comb-shaped electrode 5 is repeatedly energized, it is fixed by the thermal stress associated with the repetition. It is possible to suppress the occurrence of local cracks inside the layer 6.

In the present embodiment, the width B1 of the first connecting portion 52A and the width of the first widening portion 53A on the first connecting portion 52A side are the same, and the width C1 of the first extending portion 54A and the first extension The width of the first widening portion 53A on the existing portion 54A side is the same as that of the first widening portion 53A. The width of the second connecting portion 52B and the width of the second widening portion 53B on the second connecting portion 52B side match, and the width of the second extending portion 54B and the second on the second extending portion 54B side. It matches the width of the widening portion 53B.

By satisfying these width relationships, the side side of the first connecting portion 52A and the trapezoidal hypotenuse of the first widening portion 53A are continuously formed without a step, and the side side of the first extending portion 54A. The hypotenuse of the trapezoidal shape of the first widening portion 53A is continuously formed without a step. The side side of the second connecting portion 52B and the hypotenuse of the trapezoidal shape of the second widening portion 53B are continuously formed without a step, and the side side of the second extending portion 54B and the hypotenuse of the trapezoidal shape of the second widening portion 53B are formed. And are continuously formed without steps. In this way, when tension is applied to the wiring portion 51 from both sides of the first extending portion 54A and the second extending portion 54B of the electrode sheet 50, the tension can be uniformly dispersed by each wiring portion 51. ..

Further, in the present embodiment, when the width of the first connecting portion 52A is B1 and the length of the first widening portion 53A in the direction orthogonal to the width of the first connecting portion 52A is H1, H1 / B1 is determined. It is in the range of 0.28 to 1.12. When the width of the second connecting portion 52B is B2 and the length of the second widening portion 53B in the direction orthogonal to the width of the second connecting portion 52B is H2, H2 / B2 is 0.28 to 1.12. Is in the range of.

By satisfying the relationship of these widths, H1 / B1 and H2 / B2 satisfy the range of 0.28 to 1.12, so that the tension acting on the wiring portion 51 can be more uniformly dispersed. Here, when H1 / B1 and H2 / B2 are less than 0.28, the tension dispersion action by the first and second widening portions 53A and 53B may not be sufficient, while H1 / B1 and H2 When / B2 exceeds 1.12, the tension dispersion action cannot be expected any more. In particular, when H2 / B2 exceeds 1.12, the size of the first widening portion 53A of the comb-shaped electrode 5 becomes large, so that there may be space-like restrictions.

Further, at the center of the first widening portion 53A in the width direction, a first elongated hole 53a extending from the first extending portion 54A toward the first connecting portion 52A is formed, and the width of the second widening portion 53B is formed. At the center of the direction, a second elongated hole 53b extending from the second extending portion 54B toward the second connecting portion 52B is formed. In the center of the first and second widening portions 53A and 53B in the width direction, the tension from the first and second extending portions 54A and 54B is likely to act more than other portions, but the tension from the first and second extending portions 54A and 54B is likely to act on these portions. By providing the first and second elongated holes 53a and 53b, the tension acting on the center of the first and second widening portions 53A and 53B in the width direction can be dispersed.

2-3. About the step of fixing the wiring portion 51 to the base layer 4 Next, in the step of fixing the wiring portion 51 to the base layer 4, a part of each wiring portion 51 is formed in a state where the plurality of wiring portions 51 follow the surface of the base layer 4. The fixing layer 6 is joined to the base layer 4 so as to cover the base layer 4, and each wiring portion 51 is fixed to the base layer 4.

In this step, first, as shown in FIG. 4C, the masking material 8 is arranged on the outer peripheral surface 10b of the carrier 10 on which the electrode sheet 50 is arranged. The masking material 8 is formed with rectangular openings 81 according to the shape of each fixed layer 6 and their arrangement state, and the outer periphery thereof is exposed so that the wiring portion 51 of the electrode sheet 50 is exposed in each opening 81. The masking material 8 is arranged on the surface 10b.

Next, from the state shown in FIG. 4C, a powder obtained by mixing NiCr alloy particles and bentonite particles is sprayed toward each opening 81 in the same manner as in the second base layer 4b, for example, by gas flame spraying or plasma spraying. It is sprayed by thermal spraying to melt the NiCr alloy and form the fixed layer 6. As a result, as shown in FIG. 4D, the fixed layer 6 is formed so as to cover a part of each wiring portion 51 and to be joined to the base layer 4 in a state where the masking material 8 is removed, whereby the fixed layer 6 is formed. Each wiring portion 51 is fixed to the base layer 4 via the above.

2-4. About the step of separating a part of the electrode sheet 50 A part of the electrode sheet 50 is separated from the electrode sheet 50 so that the comb-shaped electrode 5 remains on the base layer 4. Specifically, the portion other than the comb-shaped electrode 5 is cut from the electrode sheet 50 so that the comb-shaped electrode 5 remains on the base layer 4.

With respect to the electrically heated catalyst device 1 thus obtained, the comb-shaped electrode 5 is bent at the connecting portion 52 along the width direction (axial direction D1), and the widening portion 53 and the extending portion 54 are formed. It is further bent at the boundary line and inserted into the exhaust pipe 71. After that, the tip end side portion of the extending portion 54 is inserted into the power supply box 73 and connected to a terminal (not shown) on the power supply side.

Examples of the present invention will be described below.

Stress analysis was performed on the comb-shaped electrodes having the shapes shown in FIGS. 5A to 5F. The comb-shaped electrodes 5A to 5F shown in FIGS. 5A to 5F correspond to Examples 1 to 5 and Comparative Example 1, respectively.

Unlike the comb-shaped electrodes 5F of Comparative Example 1, the comb-shaped electrodes 5A to 5E of Examples 1 to 5 have in common that they are connected from the extending portion 54 between the extending portion 54 and the connecting portion 52. It is a point that the widening portion 53 having a trapezoidal width is formed so as to approach the width of the connecting portion 52 from the width of the extending portion 54 toward the portion 52. The comb-shaped electrodes 5A to 5E of Examples 1 to 5 have different shapes of the widening portions 53.

Unlike the comb-shaped electrodes 5E of the fifth embodiment, the comb-shaped electrodes 5A to 5D of the first to fourth embodiments have one common point: the width of the connecting portion 52 and the width of the widening portion 53 on the connecting portion 52 side. This is the point we are doing. Table 1 shows the values of H1 / B1 when the width of the connecting portion 52 of each comb-shaped electrode 5A to 5E is B1 and the length of the widening portion 53 in the direction orthogonal to the width direction of the connecting portion 52 is H1. show. Since the comb-shaped electrode 5F of Comparative Example 1 does not have the widening portion 53, H1 / B1 is calculated with H1 = 0.

FIG. 6 shows the stress distribution when the extending portion 54 is pulled with the tips of the wiring portions 51 of the comb-shaped electrodes 5A to 5F according to Examples 1 to 5 and Comparative Example 1 fixed. It is a graph showing the value of the stress (maximum) acting on the wiring portion 51, the "end" is the wiring portion 51 at the end of the comb-shaped electrodes 5A to 5F, and the "center" is the comb-shaped electrode 5A to 5F. The central wiring portion 51.

As shown in FIG. 6, the stress of the wiring portion of the comb-shaped electrode of the comparative example decreased toward the end side. Further, in the order of Examples 1 to 4, the stress of the wiring portion of the comb-shaped electrode was difficult to decrease even if it proceeded to the end side, and the stress of the wiring portion from the center to the end became uniform. This is a trapezoidal width between the extending portion 54 and the connecting portion 52 so that the width of the extending portion 54 approaches the width of the connecting portion 52 as the extending portion 54 progresses to the connecting portion 52. It is considered that this is because the stress is uniformly dispersed in each wiring portion 51 by providing the widened portion 53. In particular, as shown in Examples 2 to 4, when H1 / B1 is 0.28 or more, it becomes more uniform. Although not shown here, when H1 / B1 exceeds 1.12, not only the tension dispersion effect cannot be expected any more, but also the size of the widening portion 53 becomes large, so that the space is formed. May be restricted by.

H1 / B1 of the comb-shaped electrode 5C of Example 3 and H1 / B1 of the comb-shaped electrode 5D of Example 5 are the same, but the comb-shaped electrode 5C of Example 3 stresses each wiring portion 51. Are evenly dispersed. It is considered that this is because the width of the connecting portion 52 and the width of the widening portion 53 on the connecting portion 52 side match, so that the stress acts uniformly on the wiring portions 51 on both sides.

(Example 6)
According to the procedure shown in FIGS. 4A to 4E, an electrically heated catalyst device as shown in FIG. 1 was manufactured using the electrode sheet shown in FIG. 7 corresponding to the third embodiment. First, a carrier mainly composed of SiC particles having a diameter of 80 mm and a length of 65 mm and Si particles was prepared, and a metal catalyst was supported on the carrier. The SiC particles are 70% by volume and the Si particles are 30% by volume with respect to the total amount of the single SiC particles and the Si particles. A paste material containing SiC particles and Si particles was applied to the peripheral surface of the carrier, and the paste material was fired to form a first base layer. The SiC particles are 60% by volume and the Si particles are 40% by volume with respect to the total amount of the SiC particles and the Si particles in the fixed layer. The first base layer was a porous layer having a porosity of 40% by volume and a thickness of 0.23 mm with respect to the entire first base layer. Next, on the first base layer, a sprayed powder obtained by mixing NiCr particles (32% by volume) and bentonite particles (68% by volume) made of Ni-50Cr was sprayed by plasma spraying to perform a second lower porous surface. The formation was formed (see FIG. 4A). The second base layer was a porous layer having a porosity of 10% by volume and a thickness of 0.1 mm with respect to the entire second base layer.

Next, an electrode made of stainless steel (Fe-20Cr-5Al) having 15 wiring portions having a width of 1 mm was prepared, placed on the second base layer as shown in FIG. 4B, and then shown in FIG. 4C. As described above, it was covered with a masking material having a rectangular opening of 3 mm × 3 mm. Next, the fixed layer was formed in the same manner as the second base layer. After molding the fixed layer, the masking material was removed, the excess portion was cut off, and one comb-shaped electrode was fixed to the base layer via the fixed layer. Further, the carrier 10 was rotated by 180 ° around the central axis CL, and the other comb-shaped electrode was fixed by the same step to obtain an electrically heated catalyst device.

(Comparative Example 2)
An electrically heated catalyst device was produced in the same manner as in Example 6. The difference from Example 6 is that an electrically heated catalyst device is manufactured from an electrode sheet corresponding to the comb-shaped electrode 5F according to Comparative Example 1 in FIG. 5F.

The relationship between the positions of the comb-shaped electrodes according to Example 6 and Comparative Example 2 and the size of the gap between the wiring portion and the base layer was measured. The result is shown in FIG. From this result, it was found that the gap of Comparative Example 2 had a larger variation than that of Example 6. From this result, it is considered that, as compared with Comparative Example 2, in Example 6, the wiring portion could be fixed by the fixed layer while applying a relatively stable tension to each wiring portion.

Although one embodiment of the present invention has been described in detail above, the present invention is not limited to the above-described embodiment, and various aspects are described within the scope of the claims as long as the spirit of the present invention is not deviated. It is possible to make design changes.

1: Electric heating type catalyst device, 4: Underlayer, 5-5F: Comb-shaped electrode, 6: Fixed layer, 10: Carrier, 50: Electrode sheet, 51: Wiring part, 52: Connection part, 52A: First connection Part, 52B: 2nd connecting part, 53: widening part, 53A: 1st widening part, 53B: 2nd widening part, 54: extending part, 54A: 1st extending part, 54B: 2nd extending part.

Claims (4)

A columnar carrier carrying a metal catalyst and
A plurality of wiring portions arranged at intervals in the axial direction of the carrier and extending along the circumferential direction of the carrier, a connecting portion connecting one end of the plurality of wiring portions, and the connecting portion. On the other hand, a pair of comb-shaped electrodes provided with a strip-shaped extending portion extending toward the side opposite to the plurality of wiring portions side.
An underlayer formed on the outer peripheral surface of the carrier and interposed between the comb-shaped electrode and the carrier,
An electrically heated catalyst device including a fixed layer for fixing each wiring portion to the base layer by being joined to the base layer so as to cover a part of each wiring portion.
In the direction orthogonal to the axial direction, the width of the extending portion is narrower than the width of the connecting portion.
The width between the extending portion and the connecting portion is widened in a trapezoidal shape so as to approach the width of the connecting portion from the width of the extending portion as the extension progresses from the extending portion to the connecting portion. An electrically heated catalyst device characterized in that a widened portion is formed. The width of the connecting portion and the width of the widening portion on the connecting portion side are the same.
The electrically heated catalyst device according to claim 1, wherein the width of the extending portion and the width of the widening portion on the extending portion side match. When the width of the connecting portion is B1 and the length of the widening portion in the direction orthogonal to the width direction of the connecting portion is H1, H1 / B1 is in the range of 0.28 to 1.12. The electrically heated catalyst device according to claim 2. The electricity according to any one of claims 1 to 3, wherein an elongated hole extending from the extending portion toward the connecting portion is formed in the center of the widening portion in the width direction. Heated catalyst device.

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