JPH0754644A - Electric heating-type catalyst device - Google Patents

Abstract

PURPOSE:To contrive decrease in energy consumption by partially heating a catalyst support through a process of providing a partial heating part connected to the catalyst support so as to be partially electrified. CONSTITUTION:A metallic support 15 wherein a short-circuit passage 22 in the radial direction is formed is attached in the position of a first catalyst device 11 of a catalyst device 10, and only the metallic support 15 is connected to the power supply such as a battery. The short-circuit passage 22 is formed on the end surface on the upstream side, and electric resistance of the short-circuit passage 22 is smaller than that of a band-like body for constituting a honeycomb-like column 20, so large current flows to the short-circuit passage 22. Accordingly, the short-circuit passage 22 becomes a live to build a fire even in the relative narrow range, and action of the catalyst is started near there, and the reactive heat heats the other catalyst material, so as to raise the temperature successively, thereby the catalyst is activated. Thereby, warming of the whole of the catalyst device 10 is achieved in a short period by electric power smaller than the conventional one. Accordingly, the whole of the catalyst device 10 quickly and normally purifies exhaust gas after an engine is started, the discharging time of not purified exhaust gas is shortened, and the amount of contaminant is decreased.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a catalyst device for purifying exhaust gas of an internal combustion engine for automobiles and the like, and particularly to a catalyst device whose temperature is still low and reaches an activation temperature as immediately after starting the engine. The present invention relates to an improvement in an electrically heated catalyst device in which the temperature of the catalyst is raised by energizing the catalyst when it is not in operation, so that the catalyst is quickly activated.

[0002]

2. Description of the Related Art A metal foil laminated in a honeycomb shape is used as a catalyst carrier (called a metal carrier), the surface of the carrier is coated with a substance such as activated alumina, and the coating layer is formed of platinum or other noble metal. There is one in which a catalyst for purifying exhaust gas of an internal combustion engine is configured by supporting a catalyst substance. Then, when the temperature of the catalyst is low and the catalyst substance is not yet activated and the catalyst does not perform the exhaust gas purification function, such as when the engine is started, the metal carrier itself is energized to generate heat, so that the metal can be quickly heated. It has been conventionally attempted to raise the temperature of the carrier to about 350 ° C., which is the activation temperature of the catalyst substance, to enhance the exhaust gas purification function within a short time after the engine is started. Further, as an example of a conventional technique, Japanese Patent Application Laid-Open No. 3-72953 discloses that a thin metal foil is wound from a central portion toward an outer cylinder to form a metal carrier.

[0003]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
In the technique described in Japanese Patent No. 72953), a large amount of energy is required because the whole catalyst carrier is heated by electric energy. An object of the present invention is to reduce energy consumption by locally heating a catalyst carrier.

[0004]

According to a first aspect of the present invention, in an electrically heated catalyst device which is heated by energizing a catalyst carrier made of a conductive material, a local heat generating portion connected to the catalyst carrier so as to be locally energizable. Is provided. According to a second aspect of the present invention, in the first aspect, the local heat generating portion is provided on the exhaust gas upstream side in the exhaust passage of the internal combustion engine.

According to a third aspect of the present invention, in the first aspect, the local heat generating portion is provided so as to avoid the exhaust gas inflow end portion.
According to a fourth aspect of the present invention, in the first aspect, the catalyst carrier is a metal catalyst carrier formed by laminating metal foils via an insulating layer, and the local heat generating part locally joins the metal foils so that they can be electrically conducted. It is characterized by being formed by.

A fifth aspect of the present invention is characterized in that, in the fourth aspect, the local heat generating portion is formed as a local current path by connecting electrodes so that they can be continuously energized. According to a sixth aspect of the present invention, in the fourth aspect, the metal catalyst carrier is composed of a corrugated foil having an insulating layer on the surface thereof and a flat foil, and the corrugated foil is formed into a flat foil shape at the joint of the local heat generating portion. .

According to a seventh aspect, in the fourth aspect, the metal catalyst carrier comprises a corrugated foil having an insulating layer on the surface and a flat foil,
It is characterized in that a flat foil is further stacked between the corrugated foil and the flat foil at the joint portion of the local heat generating portion. An eighth aspect of the present invention is characterized in that, in the fourth aspect, an internal space is formed near the local heat generating portion inside the metal catalyst carrier.

According to a ninth aspect of the present invention, in the fourth aspect, the metal foil is connected to the center electrode via an insulating layer and wound to form a metal catalyst carrier, and the metal catalyst carrier is connected to the other electrode. It is housed in a case, and the local heating portion is formed only on a part of the metal catalyst carrier in the axial direction, and the connection between the metal catalyst carrier and the metal case is limited to a part of the axial direction. And

According to a tenth aspect of the present invention, in the fourth aspect, the metal foil is connected to the center electrode via an insulating layer and wound to form a metal catalyst carrier, and the metal catalyst carrier is connected to the other electrode. It is housed in a case, wherein the local heating portion is formed only on a part of the metal catalyst carrier in the axial direction, and the connection between the metal foil and the center electrode is limited to a part of the axial direction. To do.

According to a tenth aspect of the present invention, in the tenth aspect of the present invention, when viewed from the connecting portion of the center electrode to the power source, the central portion is formed so that the electric current does not flow downstream from a part of the axial direction where the local heating portion is formed. An insulating part is provided only in the middle of the electrode, and the connection between the metal foil and the center electrode is limited to a part in the axial direction. According to a twelfth aspect of the present invention, there is provided a metal catalyst carrier according to the fourth aspect, wherein a metal foil and a flat foil are combined and bonded to each other, and an insulating layer is provided on a surface of the combination foil, and the insulating layer is laminated. It is characterized in that the foils are locally joined to each other so as to be electrically conductive to form a local heat generating portion, and that the joining position or the joining area between the corrugated foil and the flat foil in the combination foil is arbitrarily changed.

According to a thirteenth aspect, when an insulating layer is provided on the surface of the combination foil obtained by combining and joining the metallic corrugated foil and the flat foil in the fourth aspect, and when the insulating layer is wound and laminated on the outer side of the corrugated foil, It is characterized in that the valley of the corrugated foil of the outermost peripheral combination foil and the combination foil adjacent to the outermost combination foil are locally joined by the joining means so as to be able to conduct electricity to form the local heat generating portion.

According to a fourteenth aspect of the present invention, there is provided a metal catalyst carrier according to the fourth aspect, wherein an insulating layer is provided on the surface of the combination foil obtained by combining and joining the metallic corrugated foil and the flat foil, and the insulating layer is laminated. When forming a local heat-generating part in which the combination foils are locally joined to each other from the outer side in the stacking direction by a joining means, either a corrugated foil or a flat foil of the combination foil at the position of the local heat-generating part is formed in advance. One of the features is that the outer foil on one side in the stacking direction is cut off.

A fifteenth aspect of the present invention is characterized in that, in the fourth aspect, an insulating layer is provided on the metal foils on both sides of the local heat generating portion. In a sixteenth aspect, according to the fourth aspect, a total of two adjacent corrugated foils and flat foils of a metal catalyst carrier in which a metallic corrugated foil having an insulating layer on the surface and a flat foil are alternately laminated are locally energized. It is characterized in that a local heating portion is formed by joining as possible.

According to a seventeenth aspect of the present invention, in the fourth aspect, the local heating portions are scattered, and the metal foil portion among the scattered metal foil portions is closest to the electrode so that the metal foil portion is electrically connected to the electrode. To do. According to claim 18, in claim 4, the local heat generating parts are scattered, and the joint length of the local heat generating parts in the axial direction of the metal catalyst carrier is changed according to the formation position of the local heat generating part on the metal catalyst carrier. Is characterized by.

According to a nineteenth aspect of the present invention, in the fourth aspect, the metal foil is a combination foil obtained by combining and joining the corrugated foil and the flat foil, and the corrugated foil and the flat foil are joined in the combination foil near the local heat generating portion.
It is characterized in that it has a flexible structure by reducing the number of bonding points as compared with the bonding of the corrugated foil and the flat foil in the combination foil in the other metal catalyst carrier portion. A twentieth aspect of the invention is characterized in that, in the first aspect, the local heat generating portion is formed to be extremely short with respect to the length of the catalyst carrier in the exhaust gas flow direction in the exhaust passage of the internal combustion engine.

A twenty-first aspect of the present invention is characterized in that, in the twentieth aspect, a slit is provided in the exhaust gas flow direction of the catalyst carrier, and the carrier portion locally left in the slit is used as a local heat generating portion. According to a twenty-second aspect, in the twenty-first aspect, the metal catalyst carrier is formed by laminating metal foils with an insulating layer interposed therebetween.
It is characterized in that the slit is provided in a non-bonding portion with an adjacent metal foil, and the insulating layer is fitted in the slit.

[0017]

According to the first aspect of the present invention, the electric current is concentrated in the local heat generating portion which is locally connected so as to be able to be energized and heat is generated, so that the power consumption is reduced. Further, since the heat is locally generated, the heat capacity is reduced and the temperature rising time is shortened. In claim 2, claim 1
In addition to the above effect, since there is a local heating portion on the upstream side of the exhaust gas, the heat and flow of the exhaust gas are used to sufficiently heat the downstream portion of the catalyst where the local heating portion is not provided.

In the third aspect, in addition to the function of the first aspect, the local heat generating portion is provided at the exhaust gas inflow end portion of the catalyst.
Poor heating performance due to poisoning caused by exhaust gas. In the fourth aspect, in addition to the action of the first aspect, the metal foil is locally bonded via the insulating layer, so that the metal foil is not easily displaced. In the fifth aspect, in addition to the effect of the fourth aspect, since the electrodes are continuously joined, it is more difficult for the metal foil between the electrodes to shift. In addition, the entire current path generates heat.

According to the sixth aspect, in addition to the function of the fourth aspect, since the corrugated foil has a flat foil shape, the corrugated foil is easily joined and the local heat generating portion can be easily formed. In the seventh aspect, in addition to the effect of the fourth aspect, since the flat foil is laid on the joint portion, the joint can be easily performed and the local heat generating portion can be easily formed. In the eighth aspect, in addition to the effect of the fourth aspect, the internal space near the local heat generating portion absorbs the thermal expansion of the local heat generating portion, so that the durability is improved.

In addition to the function of the fourth aspect, in the ninth aspect, the connection between the metal case provided with the electrode and the metal catalyst carrier is limited to the portion where the local heating portion is formed.
The current is more likely to concentrate on the local heat generating portion. In the tenth aspect, in addition to the effect of the fourth aspect, since the connection between the center electrode and the metal catalyst carrier is limited to the portion where the local heat generating portion is formed, the current is more likely to be concentrated in the local heat generating portion.

In the eleventh aspect, in addition to the function of the tenth aspect, since a part of the center electrode is an insulating part in the middle, no current flows in the electrode downstream of the insulating part, and the current is concentrated in the local heat generating part. In addition, since the center electrode is left long in the axial direction of the metal catalyst carrier, it is easy to connect the metal foil to the center electrode and stack them. In the twelfth aspect, in addition to the action of the fourth aspect, since the combination foil forming the local heat generating portion is formed by joining the corrugated foil and the flat foil, if the joining position or the joining area of them is changed, The electric resistance value up to the local heat generating part changes. By utilizing this, it is possible to obtain an electrically heated catalyst device having a predetermined electric resistance value.

In the thirteenth aspect, in addition to the function of the fourth aspect,
Since the corrugated foil side of the combination foil is wound outside, it is easy to join adjacent combination foils aiming at the valley of the corrugated foil from the outermost periphery. In claim 14, in addition to the effect of claim 4, of the corrugated foil and the flat foil of the combination foil in which the local heat generating portion is located in advance, the foil on the outer side in the stacking direction is cut off. Easy to join.

In the fifteenth aspect, in addition to the function of the fourth aspect,
Since the insulating portions (slits) are provided on the metal foils on both sides of the local heat generating portion, the current does not diffuse and flow to the surroundings due to the insulating portion, and the current is concentrated on the local heat generating portion and heat is easily generated. According to claim 16, in addition to the function of claim 4, since a total of two corrugated foils and a flat foil are locally joined so as to be able to conduct electricity to form a local heating portion, the total of the corrugated foil, the flat foil and the corrugated foil is formed. The heat capacity becomes smaller and the temperature rise time becomes shorter than when three sheets are joined.

In the seventeenth aspect, in addition to the function of the fourth aspect,
Among the local heat generating parts, the metal heat generating part closest to the electrode is electrically connected to the electrode, so that the local heat generating part and the electrode are electrically short-circuited, and the electrical resistance value between the local heat generating part and the electrode is The number of determining factors is reduced, and it is easy to set the electric resistance value of the entire metal catalyst carrier to a predetermined value. In the eighteenth aspect, in addition to the effect of the fourth aspect, since the joining length of the local heat generating portion is changed depending on the formation position of the local heat generating portion, the local heat generating portion having an arbitrary heat generation amount is formed at an arbitrary position. You can

In the nineteenth aspect, in addition to the function of the fourth aspect,
Since the joining of the corrugated foil and the flat foil in the combination foil in the vicinity of the local heat generating portion is made to be a softer structure than the portion where the local heat generating portion is not formed, it is possible to sufficiently absorb the thermal stress of the local heat generating portion,
The metal foil in the part where the local heat generating part is not formed is less likely to be displaced. In the twentieth aspect, in addition to the effect of the first aspect, since the local heating portion is formed very short in the exhaust flow direction, the metal foil portion having the same heat generation ability is formed longer at the same position in the exhalation flow direction. As a result, the cross-sectional area in the direction perpendicular to the exhaust flow is large, the contact area with the exhaust gas having a high temperature is large, and the temperature rise time of the local heat generating portion is shortened.

In the twenty-first aspect, in addition to the action of the twentieth aspect, the current is concentrated in the portion left by the slit, and heat is locally generated. In claim 22, in addition to the effect of claim 21, since the slit is provided in the non-joint portion with the adjacent metal foil,
The stress acting on the overlapping and contacting portions of the metal foils can be avoided, and since the insulating foil to be laminated together with the metal foils is fitted in the slits, the reduction in strength of the metal catalyst carrier can be suppressed.

[0027]

1 to 6 show an electrically heating type catalyst device 10 as a first embodiment of the present invention, and manufacturing steps and effects related thereto. The overall schematic configuration of the catalyst device 10 is shown in FIG.
As shown in FIG. 1, the catalyst device 10 is roughly divided into three parts connected in series. The direction of the exhaust flow of the internal combustion engine is shown by the arrows, but the one provided at the most upstream side of the exhaust flow is, for example, 100c.
First catalyst device 11 including a catalyst carrier having a small capacity of about c
A relatively large portion provided immediately downstream of the first catalytic device 11 is the second catalytic device 12. The portion having a significantly large capacity, which is provided further downstream of the second catalyst device 12, is the third catalyst device 13. These three parts, which constitute the catalyst device 10 in series, are sequentially arranged in series in the series of passages 14. Air is supplied from the upstream side of the catalyst device 10 by an air supply means 100 such as an air pump.

Since the first catalytic device 11 is a feature of the present invention represented by the first embodiment, as will be described later in detail, the two catalytic devices 12 and the downstream catalytic devices 12 are connected. 13 will be described first. The second catalyst device 12 has a capacity of about 200 cc when the first catalyst device 11 has a capacity of about 100 cc. However, in any case, the catalyst device has a small capacity, whereas the third catalyst device 13 has a significantly large capacity. Second catalytic device 12 and third catalytic device 1
3 has such a difference in size (capacity),
All of them are honeycomb-shaped ceramic carriers or metal carriers,
Alternatively, it has a commonly used catalyst carrier such as a pellet-shaped carrier, does not have electric heating means, etc., and has no particular feature except that it is divided into large and small. .

On the other hand, the first catalyst device 11 in the first embodiment has a very small capacity, for example, about 100 cc, but it has a honeycomb shape which can be energized and heated. A metal carrier 15 is provided. In the catalytic device 10 of the first embodiment, the completed metal carrier 15 constituting the first catalytic device 11 is shown in FIG. In the process of manufacturing the metal carrier 15, first, two heat-resistant and conductive flat metal foils 16 such as stainless steel are prepared as elongated strip-shaped sheets, and one of them is formed into a corrugated shape. The corrugated metal foil 17 is used. Then, as shown in FIG. 3, the flat metal foil 16 and the corrugated metal foil 17 are superposed one by one, and the corresponding peaks of the corrugated metal foil 17 and the corresponding portions of the flat metal foil 16 are in contact with each other. And at least a part of them are joined by spot welding or other method to form an integrated strip 18.

Next, an insulating layer such as an oxide film is formed on the surface of the band-shaped body 18, and one end of the band-shaped body 18 is attached to the rod-shaped center electrode 19 so as to be electrically connected to the center of the band-shaped body 18. It is wound up around the electrode 19 in a spiral shape, and is wound and fastened to form the band-shaped body 18 into a honeycomb-shaped columnar 20. Then, the honeycomb-shaped column 20 is pushed into and fixed to the outer cylinder 21 which also serves as a ground electrode, and the outer peripheral end of the strip 18 is electrically connected to the outer cylinder 21. The center electrode 19 and the outer cylinder 21 are connected to a power source, and when a current flows through the flat metal foil 16 and the corrugated metal foil 17 of the strip 18,
The metal foils 16 and 17 themselves generate heat to raise the temperature of the catalytic substance such as a noble metal carried by the coating layer such as activated alumina provided on the surface thereof.

Up to the above, the structure and manufacturing method of the metal carrier 15 used in the first catalyst device 11 are substantially the same as those conventionally known, but the first embodiment with respect to the prior art. Is characterized in that the end face of the honeycomb-shaped cylinder 20 made of metal foil laminated spirally, that is, the end face on the upstream side with respect to the flow of exhaust gas, is laser welded or brazed to the center electrode 19 and the outer surface. The point is that a narrow radial short-circuit path 22 that directly connects to the tube 21 is provided in a cross shape.

The metal carrier 15 on which the radial short circuit 22 is formed is connected to the first catalyst device 1 of the catalyst device 10 shown in FIG.
It is attached to the position 1 and only the metal carrier 15 is connected to a power source 26 such as a battery as shown in FIG. Further, a switch 27, which is controlled to be opened and closed by a control device for an automobile engine (not shown), is provided by being inserted into a circuit for supplying electric power to the metal carrier 15.

Since the catalyst device 10 of the first embodiment is constructed in this way, when the internal combustion engine is started, the switch 27 is immediately closed and the metal carrier 15 is energized from the power source 26 such as a battery. . In the case of the conventional metal carrier, an electric current flows evenly through the strip-shaped body 18 forming the honeycomb-shaped cylinder 20, and the entire cylinder 20 generates heat. However, in the metal carrier 15 of the first embodiment, it is upstream. A radial short-circuit path 22 is formed on the end face on the side of the radial short-circuit path 22 that forms an electric circuit parallel to the strip-shaped body 18 that forms the honeycomb column 20. Since the electric resistance is smaller, a large current flows through the short-circuit path 22, whereas a smaller current flows through the strip-shaped body 18 inside the honeycomb-shaped column 20 or at the downstream side portion.

A short circuit 2 in the radial direction where a large current is concentrated
2, the short-circuit passage 22 is heated strongly, and only the narrow cross-shaped region corresponding to the short-circuit passage 22 in the upstream end surface of the honeycomb column 20 rapidly rises in temperature and is supported in the vicinity thereof. Since the catalyst substance present reaches the activation temperature as soon as the engine is started, a reaction that oxidizes components such as HC and CO contained in the exhaust gas of the engine,
It will start in no time. This situation is shown in Figure 5.
Is shown in. The arrow indicates the progress of the reaction due to the short-circuit path 22 in the radial direction. The radial short-circuit path 22 has a small area, but since the temperature becomes high, the vicinity thereof becomes a spark (or heat spot), which helps maintain the catalytic reaction in the vicinity thereof.

Further, generally, a large amount of unburned pollutants such as HC tends to be temporarily discharged immediately after the start of the internal combustion engine. In the case of the embodiment, the engine HC discharge at the time of first idle The measured amount was about 0.2 g. C ₆ H ₁₄ or C ₈ H which is the main component of gasoline
_Since the calorific value of HC such as ₁₈ is about 10000 cal / g, if 0.2 g of HC all undergoes an oxidation reaction (combustion) in the first catalyst device 11, it will be about 2000.
An exotherm of cal is obtained.

That is, in a state where the air-fuel ratio on the intake side is rich, such as at the time of first idle, the exhaust gas contains a large amount of unburned HC. When the catalyst is activated in such a state and sufficient oxygen is supplied into the exhaust gas by the secondary air or the like, unburned HC is burned (oxidized) by the catalyst to generate heat. Due to the heat of reaction and the heat of exhaust gas, the first catalyst device 11
And further heating the second catalytic device 12 that follows,
These temperatures will be increased sequentially.

Even if all the heat generated by the combustion of the unburned material is not actually absorbed by the metal carrier 15, as described above, the radial short-circuit path 22 and the metal carrier 15 are energized.
Since the amount of heat given to the belt-like body 18 and the amount of heat taken out to the outside as the heat of exhaust of the combustion heat of the fuel in the combustion chamber of the engine are added, the metal carrier 15 of the first catalyst device 11 and The temperature of the second catalyst device 12 and the like may rapidly rise due to the heat generation of unburned components in the exhaust gas that have been ignited (oxidation reaction) by the fire species near the short-circuit path 22 in the radial direction, and may reach the activation temperature early. it can.

In the present invention, since unburned matter in the exhaust gas is conveniently used as fuel for catalyst warm-up, pollutants such as HC, which are generally large immediately after engine start up, are heated and activated with a relatively small volume. Sufficiently removed in the first catalyst device 11 and the second catalyst device 12, which are fast. The reaction heat generated thereby has a large capacity on the downstream side.
Needless to say, it is useful for warming up the catalyst device 13 of FIG.

As described above, even in a relatively narrow region immediately after the engine is started, the radial short-circuit path 22 of the metal carrier 15 becomes a spark and the action of the catalyst is started in the vicinity thereof, and the reaction heat is In order to activate the catalyst substance in the part of (1) by raising the temperature in a chained manner and activating the catalyst substance, the whole catalyst device 10 can be warmed up with a smaller electric power than 1 kw, which is lower than before. . As a result, the catalyst device 10 as a whole performs a normal exhaust gas purification action immediately after the engine is started, the time for discharging unpurified exhaust gas is shortened, and the amount of pollutants discharged is also small.

FIG. 6 shows the temporal change of the HC emission amount after the processing by the catalyst device 10 when the internal combustion engine is operated in the so-called LA # 4 mode in order to explain the effect of the first embodiment. It is measured and shown in correspondence with changes in vehicle speed. The curve a in the diagram showing the HC emission amount is according to the first embodiment, and the H curve is obtained immediately after the engine is started.
It can be seen that the amount of C emission is decreasing. The curve b is the case where the electric heating type catalyst device according to the prior art is used, and as a result of the catalyst warm-up being delayed as compared with the case of the first embodiment, it is not possible to reduce the HC emission amount immediately after the engine is started. The difference in the HC emission amount from the first embodiment is the amount corresponding to the shaded portion in FIG. Further, the power consumed by the metal carrier is much larger than that in the first embodiment, as described above. However, after a long time, both H
The amount of C emission is about the same.

Next, a second embodiment of the present invention shown in FIGS. 7 and 8 will be described. In many embodiments described below, parts that are substantially the same as those in the first embodiment are designated by the same reference numerals, and redundant description is omitted. The second embodiment is further provided with a metal carrier 1 than the first embodiment.
5 is intended to reduce the power consumption for heating, for which the radial length of the short circuit path 22 is
The heating range by the short circuit 22 is narrowed by making the length shorter than that of the embodiment. Specifically, in addition to forming the radial short-circuit path 22 on the upstream end surface of the honeycomb-shaped cylinder 20 made of laminated metal foils, as in the first embodiment, the outer cylinder having the same end surface is formed. Ring-shaped short-circuit surfaces 28 and 29 are formed on the portion along 21 and the outer periphery of the center electrode 19 by a method such as laser welding or brazing.

At the end face portion of the honeycomb-shaped cylinder 20 in which the annular short-circuit surfaces 28 and 29 are formed, the electric resistance becomes smaller than that of the short-circuit passage 22 in the radial direction, and as a result, almost no heat is generated at those portions. , The overall power consumption can be suppressed. Thus, the radial short circuit 2
Of the end surface along the outer cylinder 21 and the center electrode 1
Even if the heat generation in the portion close to the outer circumference of 9 is suppressed, the result that is not so different from the case of the first embodiment can be obtained.

The reason is as follows.
That is, as shown in FIG. 8, the exhaust flow 30 in the honeycomb-shaped column 20 of the metal carrier 15 is not uniformly distributed on the cross section, but a portion close to the center electrode 19 and the outer cylinder 21. Since the flow velocity becomes almost zero, the flow velocity becomes maximum in the annular portion between the center electrode 19 and the outer cylinder 21. Therefore, even if heat is applied to the other portions by the short-circuit path 22 in the radial direction, the heat cannot effectively heat the downstream portion such as the metal carrier 15. Therefore, the heat can be effectively used in the radial short-circuit path 22 in order to intensively apply heat to a portion where the flow velocity of the exhaust gas flow 30 is the highest and suppress the supply of heat to other portions. The second embodiment is provided only in the area. In each of the first embodiment and the second embodiment, four short-circuit paths 22 in the radial direction are provided, but this number has no special meaning, so the number can be appropriately increased or decreased.

FIG. 9 shows an essential part of the third embodiment of the present invention. The feature of this embodiment is that a metal foil is used in place of the radial short circuit path 22 in the first and second embodiments. The spiral-shaped short-circuit path 31 is formed on the upstream end surface of the honeycomb-shaped cylinder 20 made of. Swirl type short circuit 3
The method of forming No. 1 is the same as that of the radial short-circuit path 22, and only the control pattern of the electrodes in the laser welding machine needs to be changed. When the short-circuit path 31 is formed in a spiral shape in this way, the fire species can be evenly distributed on the upstream end surface of the honeycomb column 20 of the metal carrier 15, thereby accelerating the activation of the catalyst device 10. You can Needless to say, the spiral may be multiple.

FIG. 10 shows an essential part of the fourth embodiment of the present invention. The feature of this embodiment is that the radial short-circuit paths 22 in the first and second embodiments are cut in the middle. Then, the shape is shifted in the direction of rotation. This forms radial short circuits 32 and 33. Since the radial short-circuit paths 32 and 33 are not directly connected to each other, in their gap 34 the current flows through a part of the strip 18 which forms the honeycomb column 20. Therefore, the electrical resistance increases in the region of the gap 34, and the gap 34 serves to limit the amount of current flowing through the radial short-circuit paths 32 and 33. In this case, the main current paths are the portions of the short-circuit paths 32 and 33 and the strip 18 in the portion shown as the area B in FIG. 10, and heat is also generated only in that portion. Therefore, the amount of current is adjusted by selecting the size of the gap 34, and the short circuit path 3 in the radial direction is adjusted.
It is possible to prevent the occurrence of a failure by preventing the load applied to the joining point between 2 and 33 and the honeycomb-shaped column 20 from becoming an excessive value.

FIG. 11 shows an essential part of the fifth embodiment of the present invention. The characteristic feature of this embodiment is that it is randomly distributed on the upstream end face of the honeycomb-shaped cylinder 20 made of metal foil. This is because a large number of short-circuit paths 35 such as islands having a wide area are provided. By doing so, the metal carrier 15 can be efficiently heated, and a part where the short-circuit path 35 is joined to the strip-shaped body 18 forming the honeycomb column 20 may be peeled off. However, since the remaining material can be a spark without being affected at all, there is an advantage that the spark can be reliably generated even if a part of the metal carrier 15 is damaged.

A sixth embodiment of the present invention is shown in FIGS.
The principal part of an Example is shown. As a feature of this embodiment, the short-circuit path 36 having a shape similar to the radial short-circuit path 22 in the first embodiment is an end face particularly on the downstream side of the honeycomb-shaped columnar 20 made of metal foil on which the metal carrier 15 is laminated. It is provided in. In this way, in the radial short-circuit path 36 provided on the end face on the downstream side, the heat generated by being energized can heat the metal carrier 15 itself by riding on the flow of exhaust gas in the direction of the arrow. However, since the heat is only transmitted to the upstream side by the heat conduction effect of the metal carrier 15 itself, the honeycomb-shaped columnar 2 as in the first to fifth embodiments.
Short circuit (fire type) 22, 31, 32, 3 on the upstream end face of 0
Although the heating effect is inferior to the case of forming 3,35, etc.,
When exhaust gas contains lead, phosphorus, etc., the upstream side of the catalyst generally tends to be poisoned first and loses its catalytic action. By providing the above as a spark, even if the upstream portion of the catalyst is deteriorated due to poisoning by lead, phosphorus or the like, there is an effect that it is possible to maintain the action in which the catalytic reaction is transmitted in a chain.

Needless to say, the same idea can be applied to the second to fifth embodiments to provide a short-circuit path having a similar shape to the downstream end face of the honeycomb column 20. Next, a seventh embodiment shown in FIGS. 13 and 14 will be described. The metal carrier 15 in each of the first to sixth embodiments is a strip 18 made of a metal foil.
The honeycomb-shaped cylinder 20 is manufactured by spirally winding and laminating the core electrode 19 around the center electrode 19. In this example, the honeycomb cylinder 20 is formed around the cylindrical slit holder 37 like comb teeth. A plurality of slits 38 are formed, and a laminated body 39, which is formed by folding the belt-shaped body 18 (see FIG. 3) made of the metal foil, is laminated on the slit holder 3
7, and the slit 18 at the turning point of the strip 18.
The metal carrier 40 is formed by inserting the metal carrier 40 into and fixing the metal carrier 40.

Since the metal carrier 40 does not have the central electrode 19 or the like, both ends of the strip-shaped body 18 constituting the laminated body 39 which is folded and laminated are lead wires passing through the holes 41 and 42 of the slit holder 37. It is connected to a power source such as an external battery or a switch. The lead wires are fixed in the holes 41 and 42 by, for example, a ceramic heat-resistant adhesive, so that the holes 41 and 42 are simultaneously sealed. Finally, the carrier is inserted into the outer cylinder that serves as the casing.

Corresponding to the characteristics of the present invention, the metal carrier 40 of the seventh embodiment is also formed on the upstream end face of the laminated body 39 by folding and stacking it by a method such as discharge welding as described above. Three short-circuit paths 43 as shown in 14 are provided. The short-circuit path 43 is a kind of ignition when the engine is started, like the short-circuit paths in each of the above-described embodiments, and various modifications can be considered regarding the shape and the number thereof. In addition, the short circuit 43
Similar to the sixth embodiment, a laminated body 39 that is folded and laminated
It goes without saying that it can be provided on the end face on the downstream side of.

In any of the above examples, the short-circuit path which becomes a fire by welding a part of the strips 18 on the upstream end face or the downstream end face of the metal carrier 15 or 40 by a method such as discharge welding. Formed, but
In each of the examples described below, an electric heater made of a material different from that of the catalyst carrier is attached to the end surface of the catalyst carrier so that it becomes a fire when it is energized.

First, in the eighth embodiment shown in FIG. 15, an end face (upstream side or downstream side) of a honeycomb-shaped catalyst carrier 44 made of ceramic or metal such as the metal carrier 15 described above.
In addition, a conductive heater 45 such as SiC formed in a circular shape is attached, and by energizing the heater 45, the heater 45 is used as a fire to burn combustible components such as HC and CO in the exhaust gas.
The heat heats the honeycomb-shaped catalyst carrier 44.
The reason why the heater 45 is circular is that the shape of the heater 45 is made to match with the case where the portion of the honeycomb-shaped catalyst carrier 44 where the most exhaust gas flows has an annular shape.

Various patterns are conceivable for the heater 45 in the eighth embodiment, but as a modification of the eighth embodiment, a case where a meandering heater 46 is used is shown in FIG. In this case, the heat of the meandering heater 46 can be evenly distributed over a wide range of the end surface of the honeycomb-shaped catalyst carrier 44, and the unburned components in the exhaust gas are reacted in the entire area of the honeycomb-shaped catalyst carrier 44. It will be possible.

17 to 19 show a ninth embodiment of the present invention. In an oxygen sensor (not shown) used in the exhaust system of an internal combustion engine, a heater such as a platinum print may be provided in order to heat the sensor at low temperature to ensure the operation, but in the ninth embodiment, By applying this technique, as shown in FIG. 17, a print heater 52 is formed in a meandering shape by platinum printing or the like on the end surface of a honeycomb catalyst carrier 51 made of ceramic or metal having an insulating coating formed on the surface. Is forming. FIG. 18 is an enlarged view of the portion of XVIII in FIG. 17, and most of the holes of the honeycomb-shaped catalyst carrier 51 are left unpainted by the print heater 52. When the platinum print is used as a heater, there is an advantage that the exhaust purification efficiency of the entire catalyst device is further increased because platinum itself has a catalytic action.

Although the pattern of the print heater 52 is arbitrary, FIG. 19 shows an example in which a double spiral print heater 53 is provided as a modification of the ninth embodiment. These heaters can be provided not only on the upstream end face of the honeycomb-shaped catalyst carrier 44 or 51, but also on the downstream end face in order to avoid damage due to heat shock and poisoning by lead or phosphorus. .

20 to 24, the first aspect of the present invention
An example of No. 0 will be described. Referring to FIG. 24, a metallic thin corrugated plate 101 and a flat plate 1 bonded to a positive electrode 104.
02 is overlapped and wound to form a spiral alternate layer,
A honeycomb-shaped metallic catalyst carrier 103 is formed. The corrugated plate 101 and the flat plate 102 are, for example, 20% Cr −5% A.
It is a foil material having a composition of l-75% Fe and a plate thickness of about 50 μm. In addition, the corrugated plate 101 and the flat plate 1 in the non-bonding region
On the surface of 02, an alumina layer which is an electrically insulating film is formed beforehand by an oxidation treatment.

Referring to FIGS. 20 and 23, the positive electrode 104 is provided at the center of the catalyst carrier 103 along the axial direction thereof.
Is arranged, and the positive electrode 104 is electrically connected to the catalyst carrier 103. The catalyst carrier 103 is inserted into a metallic cylindrical case 105 and fixed to the case 105 by brazing, for example, and the catalyst carrier 103 can be electrically connected to the case 105. As shown in FIG. 20, the negative electrode 106 is connected to the side surface of the case 105. As shown in FIG. 23, the positive electrode 104 is case 1
05 extends in the axial direction and is bent into an L shape to form the case 1
05 It penetrates the side. The positive electrode 104 is the insulating material 10
It is electrically insulated from the case 105 by 7.

Referring to FIGS. 20 to 22, a region 11 which is located downstream of the upper end of the catalyst carrier with respect to the gas flow.
At 0, valley 101aa of corrugated plate 101a and flat plate 1
02 and the ridge 101bb of the corrugated plate 101b adjacent to each other are joined by, for example, brazing, discharge welding, laser welding or the like in the exhaust gas flow direction by, for example, about 3 mm. Then, it flows from the center electrode to the case 105.

The catalyst carrier 103 formed as described above is coated with activated alumina or the like, and carries a precious metal (for example, Pt, Pd, Ph, etc.) as a catalyst component to form an electrically heated catalyst device. 20 to 24 is installed in the exhaust passage of the internal combustion engine, and the main catalyst device is installed in the exhaust passage downstream of the electrically heated catalyst device. The catalyst cannot exert the exhaust gas purifying action unless it becomes higher than the activation temperature. Therefore, when the engine is cold, electricity is supplied to the electrically heated catalyst device to heat it, and the catalyst on the honeycomb-shaped carrier is heated in a short time to an activation temperature or higher so that harmful components in exhaust gas can be purified. ing. Further, as shown in FIG. 22, in order to effectively use the heating energy, if there are, for example, about 20 heat sources of several mm in the exhaust gas flow direction in the vicinity of the upstream side with respect to the exhaust gas flow, the heat source is used as the ignition source. The unpurified gas such as HC emits heat of reaction and can rapidly heat the entire catalyst, and the electric power can be greatly reduced. Further, as shown in FIG. If the heat generating part is located upstream, the catalyst in the heat generating part will be poisoned by Pb, P, S, etc. due to use at high temperature, and the catalytic reaction power will decrease, and the catalyst will be discharged from the combustion chamber. There is a risk of damage due to electrical shorts in the heating part due to metallic objects
If a heating unit is provided on the downstream side, for example, about 1 mm from the upstream end,
It has been found that these problems can be solved and the catalyst performance can be sufficiently brought out.

As shown in FIG. 22, in this embodiment, when a voltage is applied, the corrugated plate 101 joined from the positive electrode 104.
And a region 110 having an area smaller than that of the corrugated plate 101 and the flat plate 102.
Electric current concentrates on the heating part. The current makes a short cut from this region 110 to the corrugated plate 101 and the flat plate 102 from the positive electrode 104, the same operation is repeated, and the current flows to the negative electrode 106.

Therefore, when a voltage is applied to the area 110, the area 110 heats up to reach the catalyst activation temperature rapidly, and when the purification of the harmful substances in the exhaust gas is started, the area 1 is heated by the catalytic reaction heat.
All the catalyst carriers 103 other than 10 are heated, and the heat of the catalytic reaction can heat the main catalytic converter. As described above, according to the present embodiment, even when the engine is cold, the area 11
By electrically heating 0, the temperature of the catalyst carrier 103 can be immediately raised to the catalyst activation temperature, whereby the exhaust gas can be purified early. In addition, a large reduction in electric power, prevention of catalyst poisoning, and generally in the case of a metal carrier, by joining the regions 110, the catalyst carrier 1
Even when 03 is exposed to high-temperature exhaust gas, axial displacement does not occur, and the strength of the catalyst carrier 103 can be improved.

26 to 39 show the 11th to 19th embodiments which are different from the 10th embodiment. In the eleventh embodiment shown in FIG. 26, the heat-generating region 110 is limited to a partial (center) region in the radial direction to further reduce power consumption. Normally, the engine condition that requires electric heating in the region 110 is when the amount of exhaust gas immediately after starting is small, and at this time, the exhaust gas mainly flows in a doughnut-shaped intermediate portion in the radial direction of the catalyst carrier 103. Therefore, exhaust gas can be sufficiently purified by heating only this donut-shaped portion.

The twelfth embodiment shown in FIGS. 27 and 28 is a further development of the embodiment shown in FIG. 26, in which the flat plate and the corrugated plate other than the donut-shaped heat generating region 110 are non-localized by, for example, brazing. Resistance value is reduced by effective joining,
The non-heat generating portion 111 is formed. As a result, the non-heating part 1
The heat generation in 11 is eliminated, and the power can be further reduced.

29 and 30 show a thirteenth embodiment.
This embodiment is different from the embodiments of FIGS. 20 to 28 in that the heat generating portion 110 is formed in a cross shape around the center electrode 104. In the area of the heat generating portion 110, the corrugated plate 101,
The contact portion of the flat plate 102 is joined by brazing or welding. As a joining method, in the case of welding, laser welding, spot welding or the like while winding the corrugated sheet 101 and the flat plate 102, and in the case of brazing, the corrugated sheet 1 is used.
01, when the flat plate 102 is wound, a binder is previously applied to the corrugated plate 101 and the flat plate 102 of the heat generating portion 110 (preferably, the corrugated plate 101, the contact portion of the flat plate 102, or
It is desirable to attach it only to the shoulder portion of the corrugated plate 101 that is in contact with the flat plate 102. ) After winding, apply the brazing material to the joint by a method such as sprinkling the brazing material on it and heat-treating it. When performing brazing, the corrugated plate 101 and the flat plate 102 are used.
By removing only the part to be brazed on the surface of the insulating film in advance, the bonding strength by brazing can be improved.

The first aspect of the present invention is shown in FIGS. 31 (a) and 31 (b).
Four examples will be shown. A feature of this embodiment is that the short-circuit path 110 having a shape similar to the radial short-circuit path in the thirteenth embodiment.
Is provided on the end face particularly on the downstream side of the honeycomb-shaped metallic catalyst carrier 103 made of a metal foil in which a corrugated plate and a flat plate are laminated. As described above, in the radial short-circuit path 110 provided on the end face on the downstream side, heat generated by energizing the short-circuit path 110 can heat the corrugated plate and the flat plate itself by riding on the flow of exhaust gas in the direction of the arrow. However, the heating effect is inferior to the case where a short-circuit path is formed on the upstream end face of the honeycomb-shaped metallic catalyst carrier 103, because it is transmitted only to the upstream side by the heat conduction effect of the corrugated plate and the flat plate itself. If the exhaust contains lead, phosphorus, etc., the upstream side of the catalyst generally tends to be poisoned first and lose its catalytic action. By providing 110 as the ignition source, there is an effect that even if the upstream portion of the catalyst is deteriorated due to poisoning by lead, phosphorus or the like, the action of chain-catalyzing the catalytic reaction can be maintained.

A fifteenth embodiment is shown in FIGS. 32 and 33.
This embodiment is used when the capacity of the catalyst carrier is large, and is provided at several places in the axial direction (exhaust gas flow direction) of the heat generation region 10 to rapidly activate the entire catalyst carrier 3. A sixteenth embodiment is shown in FIGS. 34 and 35. In this embodiment, a slit 170 in the axial direction is formed in a part of the honeycomb, and the portion 110 where the slit 170 is not formed is heated.

36 and 37 show the seventeenth and eighteenth embodiments, respectively. In order to easily form the heat generating region 110, in FIG. 36, the corrugated plate 101 in the region 110 is partially made into a flat plate 121, and this part is laser-welded, for example, to simplify the production of the region 110. In FIG. 37, at least one flat plate 112 is added to the region 110, and this part is laser-welded, for example, to simplify the production of the region 110. 11 in these figures
5 represents an electric current.

A nineteenth embodiment is shown in FIGS. 38 and 39. In the present embodiment, the ceramic support 181 other than the opening 180 is provided downstream of the upstream end with respect to the exhaust gas flow direction of the ceramic carrier 103, and the metal wire 18 made of, for example, tungsten.
5 is provided to form a heat generation area. This embodiment is the eleventh
(FIG. 26) As in the twelfth embodiment (FIG. 27), the heat generation region is limited to a partial (center) region in the radial direction to reduce power. In addition, although the ceramic honeycomb structure is shown in this embodiment, the same effect can be obtained even with a granular catalyst which is usually called a pellet catalyst.

FIG. 40 is a front view showing a twentieth embodiment of the catalyst carrier of the electric heating type catalytic converter according to the present invention. 41 is a cross-sectional view taken along the line AA in FIG. 40, and the left side is the exhaust upstream. In these figures, 201 is a center electrode, and 202 is an outer cylinder which serves as the other electrode. Reference numeral 203 denotes a metal foil carrying a catalyst composed of a corrugated plate and a flat plate, one set or a plurality of sets of which are arranged from the center electrode 201 to the outer cylinder 2.
No. 02 is spirally laminated. The metal foil 203 is insulation-coated with alumina or the like, but the first annular portion 231 and the outer cylinder 202 near the center electrode 201 divided by the two-dot chain line.
The second annular portion 232 in the vicinity is short-circuited in the radial direction by discharge joining or the like in a relatively wide range. On the other hand, the third annular portion 233 between the annular portions 231 and 232 is shown in FIG.
41. In the same manner, only the four substantially rectangular specific portions 233a in the exhaust upstream side end cross-section indicated by dots in FIG. 41 are similarly short-circuited in the radial direction, and the other portions are maintained in the radial insulation by the insulating coating. .

An internal space 233b of the catalyst carrier is formed in the vicinity of the exhaust gas downstream side of each specific portion 233a. As shown in FIG. 41 and FIG. 44, which is a cross-sectional view taken along the line BB thereof, the internal space 233b has a specific portion 2 in the front direction.
It has a projected area almost equal to that of 33a, and is processed into the metal foil 203 before being laminated. In the catalyst carrier thus configured, when a voltage is applied to the center electrode 201 and the outer cylinder 202 that serves as the other electrode during cold start of the engine or the like, each specific portion 233 in the third annular portion 233.
Since parts other than a are insulated in the radial direction,
0 and as indicated by the arrow in FIG.
3a only in the radial direction, these specific parts 233a
Since the electric resistance of is considerably larger than that of the first and second annular portions 231, 232, only the specific portion 233a generates heat and the portion reaches the catalyst activation temperature. The exhaust gas at this time is purified by the specific portion 233a located upstream of the exhaust gas, the other portion of the catalyst carrier is also heated by the heat of the chemical reaction, and the entire catalyst carrier reaches the activation temperature in a relatively short time. The subsequent exhaust gas can be purified well.

In this embodiment, the specific portion 2 of the catalyst carrier is
Since only 33a generates heat, its power consumption becomes considerably smaller than that of all catalyst carriers that generate heat, and the battery can be miniaturized. Further, at this time, only the specific portion 233a thermally expands, but the expansion in the axial direction of the catalyst carrier is absorbed by the above-mentioned internal space 233b, and the stress in this direction is prevented from being generated in other portions. Internal stress in the catalyst carrier can cause the metal foil 203 to crack after a short period of use.
The cracks are fatal to the energization heat generation type catalytic converter because they cause a failure in energization, etc. However, according to the present embodiment, such a decrease in mechanical life of the catalyst carrier is improved.

FIG. 42 is a front view showing a twenty-first embodiment of the catalyst carrier of the electric heating type catalytic converter according to the present invention. 43 is a cross-sectional view taken along the line CC of FIG. 42, and the left side is the exhaust upstream, as in FIG. 41. Only differences from the 20th embodiment (FIGS. 40 and 41) described above will be described below. Specific portion 23 intended to generate heat in this embodiment
3a 'is provided inside the catalyst carrier downstream of the exhaust upstream side cross section. This is because the exhaust gas upstream side end portion of the catalyst carrier is likely to deteriorate due to the adherence of harmful substances and the like in the exhaust gas, so the exhaust gas purification performance is slightly lower than in the twentieth embodiment, but the catalyst carrier is used for a long period of time. This is because it is advantageous in enabling

The internal space 233b 'formed in the vicinity of the specific portion 233a' is specified as shown in FIG. 43, the DD sectional view thereof in FIG. 45, and the EE sectional view in FIG. It is formed so as to surround not only the downstream side of the portion 233a ′ but also its four side surfaces. The catalyst carrier thus constructed has the specific portion 2 as in the above-mentioned embodiment.
Only 33a 'can generate heat, and exhaust gas at the time of engine cold start can be satisfactorily purified with a small amount of power consumption, and the thermal expansion of the specific portion 233a' is caused by the internal space 23.
Since 3b ′ can absorb not only the extension of the catalyst carrier in the axial direction but also the extension in the radial direction and the circumferential direction, stress in any direction is not generated in the portion other than the specific portion 233a ′. The mechanical life of the catalyst carrier can be further improved as compared with the above-mentioned embodiments.

The catalyst carriers of these examples are strong in strength because the first and second annular portions 231 and 232 and the specific portion are joined in the radial direction, and have a small internal space. Even if the above is provided, the catalyst carrier is not deformed in the downstream direction by the exhaust gas. The position and shape of the internal space are not limited to those of the two illustrated embodiments,
For example, even in a space provided only near one side surface of a specific portion intended to generate heat, it is possible to absorb the thermal expansion of the specific portion in this direction, so that the catalyst carrier can be used in comparison with the conventional case. The stress generated can be relieved and its mechanical life can be improved.

FIG. 47 shows a sectional view of the catalyst with heater of the 22nd embodiment. Flat and corrugated metal foil 3 on the center electrode 301
02 is wound and stored in the outer cylinder 303. Flat foil 30
As shown in FIG. 48, the 2a and the corrugated foil 302b are laminated and wound, and the joint portion 304 includes the valley portion of the corrugated foil of the outer layer, the flat foil, and the peak portion of the corrugated foil of the inner layer. It is provided at a position where and intersect. Further, as shown in FIG. 49, the flat foil 302
a is thicker than the corrugated foil 302b. The operation of this embodiment will be described below. FIG. 50 shows an electrically equivalent circuit of the heater-equipped catalyst of this embodiment. The resistance of the joint 304 is indicated by R, and the resistance of the flat and corrugated foil between the joints 304 is indicated by r. Combined resistance R
_T is n · R + (n− when the number of joints 304 is n.
1) .r, and the amount of heat generated at the junction 304 is represented by Q.n.R / _RT when the input power is Q. As shown in this embodiment, by increasing the thickness of the flat foil 302a, the combined resistance R _T decreases, so that the amount of heat generated at the joint 304 can be increased when the input power is constant. Also, by thickening the flat foil 302a, the durability of the catalyst carrier is also improved.

FIG. 51 shows a sectional view of the catalyst with heater of the 23rd embodiment. In the twenty-second embodiment described above, the joint 304
As shown in FIG. 48, the inner corrugated foil 302b and the flat foil 30 are
It was provided at the position where 2a and the outer corrugated foil 302b intersect. On the other hand, in this embodiment, the flat foil 321 and the corrugated foil 322 are used.
The joint portion 304 is provided at the position where the contact is made.
The operation will be described below. Compared with the 22nd embodiment, the number of foils to be joined is reduced from 3 to 2, so that the heat capacity of the joining portion 304 becomes 2/3, and the temperature raising time can be made much shorter. As a result, the rate of temperature rise of the catalyst carrier is also increased, and it is possible to accelerate the purification start time of HC after startup.

Further, since the resistance value at the joint 304 also becomes large, when the heater-equipped catalyst is operated under the constant voltage control,
There is also an advantage that the number of joints 304 can be increased. 52-
Reference numeral 53 shows a twenty-fourth embodiment of the heater-equipped catalyst of the present invention. In this embodiment, when the flat and corrugated metal foil 302 is wound around the center electrode 301 and stored in the outer cylinder 303, as shown in FIG.
As shown in (3), the corrugated foil 302a is wound so that it is on the outside.
A front view of the completed carrier is shown in FIG. Junction 304
Is provided at a position where the valley portion 321c of the outer corrugated foil and the peak portion 322c of the lower corrugated foil are aligned. FIG. 54 shows a method of forming the joint portion 304 of the carrier thus configured.
In FIG. 54, a laser welder 305 is used to join the joint 3
In the case of forming 04, the valley portion of the corrugated foil of the outer layer is welded by the laser beam 306. The flat and corrugated foil 302 is wound, and the joint portion 304 is sequentially formed. Such joining is possible because the corrugated foil is located outside the flat foil in the portion where the joining portion 304 is provided. As described above, in the present embodiment, the flat plate inside the carrier and the corrugated plate are joined to each other to form the heating part become. Further, the strength of the carrier is improved when only the outermost periphery is made of a flat plate and is joined to the outer cylinder 303.

55 (a) and 55 (b) are sectional views showing the radial and axial arrangement of the joints of the catalyst with heater of the twenty-fifth embodiment. A flat and corrugated combination metal foil is wound around the center electrode 301 and stored in the outer cylinder 303.
The joining portions 304-a and 304-b are joined by laser welding when winding the metal foil. The joint 304-a is installed relatively upstream of the catalyst carrier 302, and the joint 304-b is installed near the center of the catalyst carrier 302. Also the joint 3
04-b is located substantially in the middle in the radial direction of the joint 304-a. The operation is shown below. Center electrode 30
1. When electric current is applied between the outer cylinder 303 and the joint portion 304-a, 3
04-b generates heat. When the exhaust gas condition is rich, there are many unburned gas components, so if the joint 304-a is installed only on the upstream side, the reaction heat is sufficiently transmitted to the downstream side of the carrier,
The entire carrier is activated in a short time. On the other hand, when the exhaust gas condition approaches the stoichiometric air-fuel ratio, the unburned gas component decreases and the reaction heat decreases, resulting in poor heat spread. Therefore, FIG.
As shown in, the joints 304-a and 304-b are
By providing two stages, the entire catalyst carrier can be easily activated. FIG. 56 shows a modification of the 25th embodiment. In this modification, the joint portion 304-b at the central portion is provided close to the joint portion 304-a at the upstream portion, and when the number of joint portions is relatively large, the same effect as the embodiment of FIG. 55 is obtained. Can be obtained.

FIG. 57 is a sectional view showing the radial arrangement of the joints of the catalyst with heater according to the 26th embodiment. Metal flat and corrugated foil wound around the center electrode 301 are alternately laminated and housed in the outer cylinder 3. Center electrode 30
1 and the vicinity of the outer cylinder 303, a joint region 302-where both end surfaces are joined to each other by electrical discharge machining welding and the contact portions of the flat wave foil are joined.
a, 302-b. In the vicinity A and B of the joining regions 302-a and 302-b of the inner joining portion 304, the ends 304-a and 304-b of the inner joining portion are electrically connected to the joining regions 302-a and 302-b, respectively. For,
The joint portions 304 are respectively connected to the joint regions 302-a and 302.
It is provided in the radial direction toward -b. The operation and effects will be described below. The end of the joint 304 is joined to the joint region 302-a,
When not conducting to 302-b, the resistance of the catalyst with heater is as shown in FIG. 58 (a), and the resistance from the end of the joint 304 to the joint regions 302-a and 302-b passes through the flat and corrugated foil. Current flows, the resistances r ′ and r ″ of the flat and corrugated foils become uncertain factors, and the resistance R _H of the catalyst with heater cannot be controlled. The end portions of the joint portion 304 are connected to the joint regions 302-a, 3
When it is connected to 02-b as shown in FIG.
_H becomes a function of only the resistance R of the joint, the flatness between the joints, and the resistance r of the corrugated foil, and the resistance R _H can be managed with high accuracy.

59 to 61, the twenty-seventh aspect of the present invention is shown.
Examples will be described. In the metal foil energization type catalyst with heater, a heater 401 composed of a flat plate 401a and a corrugated plate 401b as shown in FIG. 59 is formed with an insulating film on its surface, and then a center electrode 402 is formed as shown in FIG. A hot spot is formed by laser welding 412 while wrapping around. However, the hot spot can be formed in FIG.
As shown in (b), there is a problem that hot spots cannot be formed at arbitrary positions only at the locations where the crests 403 of the corrugated sheet and the troughs 404 of the corrugated sheet meet, and the manufacturability is poor. In the present embodiment, it is possible to form a hot spot at an arbitrary position by previously forming a cut on the corrugated plate of the heater and joining a flat plate at a position matching the cut when the heater is wound. It is a thing. The structure will be described. As shown in FIG. 61, the corrugated plate 401b of the heater is partially cut to form a cut 405 (FIG. 61 (a)). Next, the flat plate 406 is joined to the inner heater portion adjacent to the cut 405 when the heater is wound (FIG. 61B). After this, as shown in FIG. 61C, hot spots 407 are formed in the cuts 405 by laser welding. A hot spot can be created at an arbitrary position, and positioning of the laser 412 can be facilitated.

62 and 63, the second embodiment of the present invention
8 examples will be described. Only the points different from the 27th embodiment will be described. As shown in FIG. 62, a notch 425 is made near the apex 424 on the corrugated plate on which a hot spot is to be formed. Corrugated plate 426 and flat plate 427
Are joined only at the laser weld 428. All the hot spots are set to have a structure as shown in FIG. 62, and hot spots are formed by laser welding while winding the heater. FIG. 63A shows a part of the current path at the time of completion. When a voltage is applied to the center electrode, a current 429 flows from the center electrode toward the outer cylinder. At this time, heat is generated in the hot spot portion 430 having a high resistance value. FIG. 63 (b) shows a current path in the case where there is no notch 425 as described above. In this case, unlike the case of FIG. 63 (a), since the flat plate and the corrugated plate are sufficiently joined, the resistance value is small. Hotspot part 43
Only 1 will produce heat. As described above, according to the present embodiment, the number of hot spots can be increased by forming hot spots also at the joint between the flat plate and the corrugated plate, and the catalyst can be easily activated.

64-70, the twenty-ninth aspect of the present invention is shown.
Examples will be described. 64-67, the flat plate 50 wound around the positive electrode 501.
5. A large number of resistance adjusting holes 507 are provided in the area B of the corrugated plate 506. Further, these adjustment holes 507 are installed in a partial region (B) in the axial direction, that is, in the flow direction of exhaust gas, from the winding start to the winding end of the flat plate 505 and the corrugated plate 506 on the upstream side and the downstream side. .

FIG. 65 shows the positive electrode 501 and the case 503.
A simple equivalent circuit in the case of applying a DC voltage between and is shown. The area B and the area A are connected in parallel. In the region B, the electric current path is limited by the adjustment hole 507, so that the electric resistance value R _B is much higher than the electric resistance value R _A in the region A, and therefore, almost no heat is generated. On the other hand, in the area A, the electric resistance value R _A becomes low, so that almost all the current flows through the area A by energization and becomes a heat generating portion. The heat generation amounts Q _A and Q _B of the regions A and B during energization are Q _A = V ² / _RA and Q _B = V ² /
It becomes R _B (Q _A > Q _B ).

When a voltage is applied, the area A generates heat and quickly reaches the catalyst activation temperature, so that harmful substances in exhaust gas can be purified. Further, when the area A reaches the catalyst activation temperature and purification of harmful substances in the exhaust gas is started, the temperature of the areas other than the area A is also raised by the heat of catalytic reaction. Further, when the catalytic reaction of the electric heating catalytic converter proceeds, the catalytic reaction heat can heat the main catalytic converter.

As described above, according to the present embodiment, even when the engine is cold, the area A can be immediately heated to the catalyst activation temperature by heating the area A by energization. It can be purified early. Further, since only a part of the catalyst carrier 502, that is, the region A is electrically heated, the amount of electric power required to heat the catalyst carrier can be significantly reduced.

68 to 70, a third heating area is different from the third heating area.
0 Example is shown. Only the points different from the 29th embodiment will be described. In this embodiment, the adjustment hole 507 is not provided in the area C ′ in the vicinity of the positive electrode 501 and the outer peripheral area C ″ of the catalyst carrier 502. That is, flat plate 5
05 'and the corrugated plate 506' are formed as shown in FIGS. 69 and 70 and wound around the positive electrode 501. Therefore, in the regions C ′ and C ″, the current density in the region A is the same as that in the region B, the region does not generate heat, the region to be heated is smaller than that in the 29th embodiment, and the power consumption is further reduced. Can be achieved. Further, in the twenty-ninth and thirtieth embodiments, the shape of the adjusting hole is circular, but it is obvious that it may be rectangular or slit-shaped. Thus, the 29th
And in the thirtieth embodiment, when the catalyst carrier is energized, it partially generates heat, so that it is possible to reduce the amount of power consumption required to heat the catalyst carrier.

71 and 72 show the 31st embodiment of the present invention. In this embodiment, a slit is formed in the axial direction of a portion of the catalyst which is not desired to generate heat, thereby cutting off the current passage,
Power saving is achieved by making only a part (upstream side) in the axial direction generate heat. That is, in FIG. 71, several flat and corrugated metal foils 502 are wound around the center electrode 501 and housed in the outer cylinder 503. Center electrode 5
01 is taken out through the insulating material 504.
FIG. 72 shows a developed view of the metal foil 502 joined to the center electrode 501. In both the corrugated foil and the flat foil, some slits 510 are provided in the axial direction from the downstream side to the upstream side. Such slits 510 are formed before winding the metal foil (corrugated foil, flat foil).

The operation will be described below. Center electrode 501, outer cylinder 5
When energized during 03, a current flows as shown by arrow A in FIG. Therefore, the part that mainly generates heat is the part where the current density is high, that is, the part on the upstream side indicated by the region B. Since the current concentrates and flows in the region B where the heat mass is small, it is possible to obtain a fast temperature rise of the catalyst with a low electric power. If the upstream side of the catalyst reaches the activation temperature quickly, the unburned gas components in the exhaust gas can be burned quickly, and the entire catalyst quickly reaches the activation temperature.

FIG. 73 shows a 32nd embodiment of the present invention. When manufacturing the heater, the flat foil 1a and the corrugated foil 1b are joined to each other one by one to form spot welding points (FIG. 73 (b)).
When the temperature of the engine is increased and the heater is exposed to high temperature, the thermal expansion of the heater causes large thermal stress, which causes crushing of cells and bending of flat foil. obtain. On the contrary, if the flat foils 1a and the corrugated foils 1b are all joined at wide intervals, for example, by joining them in five crests (see FIG. 73 (c)), the rigidity in the radial direction is reduced to form a flexible structure and the heater is There is a problem that the scoping phenomenon occurs due to the exhaust gas pressure retreating to the downstream side.

Therefore, in this embodiment, the catalyst is provided with a rigid structure portion and a flexible structure portion, and the flexible structure portion absorbs thermal expansion to improve the cold heat durability. That is, as shown in FIG. 73, the outer cylinder and the regions A and C in the vicinity of the center electrode are spot-bonded for each peak (see FIG. 73 (c)) to form a rigid structure (see FIG. 73 (b)). 5 in the middle area B between the cylinder and the center electrode
Spot-join each mountain to make a flexible structure. When exposed to high temperature, the flexible structure B can absorb the thermal expansion P generated in the rigid structures A and C to prevent the cells from collapsing, and the rigid structure B allows the heater to operate by the pressure of the exhaust gas. It is possible to prevent the scoping which is retracted to the downstream side.

FIG. 74 shows a 33rd embodiment of the present invention. The basic structure of this embodiment is similar to that of the embodiment shown in FIG. Parts common to the embodiment of FIG. 5 are designated by common reference numerals, and only different points will be described. The center electrode 19 in contact with the catalyst 20 has a conducting portion 19a only near the upstream end where the short circuit 22 is formed, and an insulating layer 19b is formed at the other portion to insulate the catalyst 20 from the catalyst. .
Similarly, in the outer cylinder 21 that contacts the catalyst 20, only the vicinity of the upstream end where the short-circuit path 22 is formed is used as the conductive portion 21a, and the insulating layer 21b is formed in the other portions to form the catalyst 20.
Insulate between and. As a result, electricity can be concentrated and flowed only in a narrow area of the catalyst to be locally heated.

FIG. 75 shows a thirty-fourth embodiment of the present invention. As in the 33rd embodiment described above, the center electrode 19 contacting the catalyst 20 is connected to the catalyst 20 only in the region where the heat generating portion 22 is formed, so that the center electrode 19 is provided in the middle of the center electrode 19.
5 (a), a space 19c is formed, or as shown in FIG.
As shown in FIG. 5 (b), the insulator 19d is inserted to interrupt the current path. Alternatively, as shown in FIG. 75 (c), a space 19c is formed in the middle of the center electrode 19 to form the center electrode 19
The current path inside the catalyst 20 by forming a radial slit 19e on the downstream side of the heat generating portion 22 of the catalyst 20, which is formed by laminating a flat foil and a corrugated foil and winding the foil around the central electrode. By limiting the path only to the upstream side, the electric circuit becomes short and heat can be efficiently generated.

As described above, in the thirty-third and thirty-fourth embodiments, power consumption can be reduced by making the electric circuit narrow or short. FIG. 76 shows a thirty-fifth embodiment of the present invention. In the structure in which the flat metal foil 1a subjected to the oxidation treatment and the corrugated foil 1b are overlapped and spot-bonded at every 5 peaks (position A), and such a combined foil is wound / laminated around the center electrode, In this case, the combined foils are laser-bonded at arbitrary positions. That is, at the B position with the illustrated combination foil, the corrugated foil (valley) of the combination foil, the flat foil and the peaks of the corrugated foil of the combination foil are joined, and with the combination foil at the C position, the combination foil The corrugated foil (valley) and the flat foil and the corrugated foil (peak) of the combination foil are joined.

In this case, if a current flows from the combination foil side to the side, in the intermediate combination foil, the current flows only between the A position and the B position close to the C position, that is, only the interval (a). It does not flow, and the electric resistance value changes depending on the laser bonding position. Therefore, a stable electric resistance value can be obtained by predetermining the distance between laser bonding (positions B and C), the position and number of spot bonding (position A).

FIG. 77 shows a 36th embodiment of the present invention. In this embodiment, when the flat foil 1a and the corrugated foil 1b, or a combination of these foils are used to form an axial heat generating portion (hot spot) 22 by laser welding or the like, the hot spot 22 is formed depending on the location. The length in the axial direction is changed. For example, as shown in the drawing, the axial length of the hot spot 22 is made longer in the region closer to the center electrode 19, and conversely, the axial length of the heat spot 22 is made shorter in the region closer to the metal case 21. As a result, it is possible to give an arbitrary amount of heat generation in an arbitrary area of the catalyst. That is, FIG. 78 shows the length of the hot spot and its resistance value. The longer the hot spot length, the lower the resistance value and the larger the amount of heat generation.
Further, FIG. 79 shows the heat generation amount of the hot spot and the optimum interval of the hot spots, but it is understood that the hot spots may be arranged so that the larger the heat generation amount, the larger the interval.

80 (a) and 80 (b) show the thirty-seventh aspect of the present invention.
An example is shown. As shown by the hatched portion in FIG. 80 (a), the heat generating portion 22 is formed by slightly bending a substantially cross shape into an approximately S shape on the catalyst upstream end surface. In this way, the heat generating portion 22 can have any shape. Figure 80
(C) is a modified example of the thirty-seventh embodiment, in which the heat generating portion 22 is provided with a plurality of portions 22a having small axial dimensions (that is, portions having a short joint length), and heat is generated in these portions. The heat generation is made to be larger than that of the other portions of the portion 22.

FIG. 81 shows a thirty-eighth embodiment of the present invention in which a plurality of portions 22b having a reduced width are provided in the substantially cruciform heat generating portion 22, that is, the electric passage, and heat is locally generated at these portions. To create a place where the catalytic reaction takes place quickly. In this way, by locally forming a portion having a large calorific value, it is possible to locally accelerate the catalytic reaction and achieve higher performance and lower power consumption.

82 (a), 82 (b) and 83 show the 39th embodiment of the present invention. In this embodiment, when the heat generating passage 22 having an arbitrary shape is formed on the upstream end surface of the catalyst 20 as the surface layer heating portion, the heat generating portion 22 is projected upstream of the non-heat generating portion to reduce heat escape. Heating part 2
It promotes the heating of 2. Such a heating unit 22
In order to form the protrusions, as shown in FIG. 83, the protrusions 2 are formed in advance on the metal foil (combined foil in the case of combining the flat foil and the corrugated foil) around the center electrode 19.
It is desirable that 2'is provided so that when the metal foil is wound and laminated, these protruding portions 22 'are continuously connected to form a protruding heat generating passage 22.

84 to 88 show the 40th embodiment of the present invention. Corrugated foil of at least one of the flat foil 1a and / or corrugated foil (corrugated foil 1b in the illustrated embodiment) of at least one layer of a plurality of combination foils in a catalyst with a heater in which the flat foil 1a and the corrugated foil 1b are laminated or wound. In the portion A where the flat foil and the flat foil are not in contact with each other, an insulating space 562 is provided by cutting off the axial upstream end by several mm (hereinafter, such a space 56
A portion A provided with 2 is referred to as a bridge portion), and a reinforcing foil 560 having a protruding portion 564 that fits in this space and having a surface insulated with an oxide film or the like is brought into contact with the corrugated foil 1b to be laminated. Alternatively, the structure should be such that it is held by the wound body.

As shown in FIG. 86, at least one layer of a laminate obtained by winding and laminating the flat foil 1a and the corrugated foil 1b around the center electrode 19, for example, the corrugated foil 1b shown in the figure and the area a shown in the figure. A bridge portion is formed in the flat foil 1a portion of the above. FIG. 87 is an enlarged view of the area a of FIG. 86.
Although the reinforcing foil 560 is not shown in the figure, the current path cross-sectional area of the bridge portion of one layer of the corrugated foil 1b is narrowed, and the bridge of a part of the flat foil 1a of the portion a where one corrugated foil layer overlaps one another is overlapped. By narrowing the current path cross-sectional area of the portion, the current flowing from the center electrode (positive electrode) 19 to the outer cylinder (negative electrode) 21 is concentrated in the bridge portion to generate heat. The current is configured so as not to flow to the ground (outer cylinder) 21 unless it always passes through the bridge portion. The hatched portion in FIG. 87 is a portion where the insulating space 562 is provided, that is, a portion where the current path is narrowed.

FIG. 88 is a diagram for comparing and explaining the case where such a bridge portion is not provided (a) and the case where such a bridge portion is provided (b). In FIG. 88 (a), since the joint portion of the corrugated foil and the flat foil and the portion of the heat spot where the current path is narrowed and generates heat as a heater are the same, the joint area is ensured in order to secure the joint force in terms of structural durability. While I want to take a big
There is a problem to reduce the cross-sectional area of the current path in order to reduce the power consumption. Due to the structure, the depth t of the heat spot is required to be 3.0 mm or more. Since L is the thickness of the foil, two foils are used, L = 100 μm = 0.1 mm, and the width W of the heat spot has a width of 50 μm to 200 μm, which is observed to vary depending on the pressure applied when wound.

The resistance value R is represented by the following equation: R = Pr (L / W · t) 1 / N Pr is the specific resistance (Ωcm), N is the number of current paths W has a variation. As a result, the heater cannot be heated uniformly. Also, L
Since it is determined by the thickness of the foil, if it is attempted to increase the resistance R, there is a limit to the means for increasing the number of junctions in series in the radial direction. That is, there is a limit to the catalyst cross-sectional area or radius.

If t is large, it is advantageous in terms of structural durability, but it goes against power reduction. Further, there is a possibility that the resistance R may fluctuate depending on the width accuracy of the bonding foil brazing material that determines t. By the way, when the current path at one spot heater point is calculated, R = 0.004 × 0.01 / (0.005-0.020) × 0.3 = 0.027-0.007 (Ω), which is a four-fold variation. There is a possibility of

When a current path is formed in the foil bridge portion as shown in FIG. 88 (b), it is not affected by the pressure force of the foil, so R = 0.004 × 0.05 / 0.005 × 0. 3 = 0.133 (Ω), the resistance value can be made large, and the variation in W value is the thickness of the foil itself, so the variation is small.

89 to 92 show a forty-first embodiment of the present invention. In the combination foil of flat foil and corrugated foil, the width of the flat foil is made short and the combination foil 602 (FIG. 89 (a)) in which a portion without the flat foil is provided on the upstream side, and the width of the flat foil is made short and the downstream side is formed. The combination foil 603 (FIG.
(B)) and the center electrode 6 as shown in FIG. 89 (c).
01 is alternately joined and wound. As a result, the combination foils 602 and 603 overlap as shown in FIG.
When the hot spot 607 is formed by laser welding or the like, as shown in FIG. 91, as shown in FIG. 91, the combination foil (that is, corrugated foil) 602, 603 in the portion without the flat foil is aimed at the position 6.
Laser irradiation or the like is performed on 07. As a result, the flat foil of the combination foil located on the lower side or the inner side is joined. As a result, as shown in FIG. 92, the heat spots 607 are alternately formed on the upstream side and the downstream side inside the catalyst. When the heat spots 607 are to be formed alternately at the upstream side and the intermediate position, it is necessary to make the width of the flat foil of the combination foil 603 narrower.

FIG. 93 shows the 42nd embodiment of the present invention. FIG. 94 is an enlarged view of part B of FIG. 93. When a current path is formed on the side end surface of the catalyst, for example, as shown in FIG. 93, the brazing material 611 and the corrugated foil 612 and the corrugated foil 612 are formed on the surface of the portion indicated by the hatched portion A in FIG. It is applied so as to cover the flat foil 613. As a result, FIG.
As shown in, a current 616 flows from the battery 614 through the center electrode 615 toward the outer cylinder 617.

95 to 98 are for explaining the 43rd embodiment of the present invention. A metal thin plate on which an insulating film is formed, that is, a flat foil 1a and a corrugated foil 1b are spirally wound around a center electrode 19, and these thin plates are locally joined by laser welding or the like to generate a heat. In the case of forming 22, it is necessary to arrange the heat generating portions 22 at equal intervals in order to uniformly heat the entire surface of the catalyst, but heat is generated because the current path is formed from the catalyst central portion to the outside. Part 22
However, the arrangement has a problem that the inside cannot be uniformly heated because the inside is dense and the outside is rough. For example, when three sets of combinations of the flat foil 1a and the corrugated foil 1b are wound around three positions at equal angular intervals around the center electrode 19 to form a catalyst laminate, the corrugated foils 1b are spaced at equal intervals (for example, When laser joining is performed at intervals of 5 peaks, as shown in FIG. 96, the current c always tries to flow from the center electrode 19 to the outer cylinder 21 by connecting the joining points that are at the shortest distance to each other. As shown in FIG. 97, the outer peripheral side is sparser.

As described above, since the distance between the hot spots 22 is larger toward the outer side, the heat generation amount of the hot spots 22 is larger toward the outer periphery side as shown by the circle size of each hot spot 22 in FIG. is doing. As a method of changing the heat generation amount of the hot spot 22, as shown in FIG. 78, the resistance value is changed by changing the welding length in the exhaust gas flow direction in the laser welding for forming the heat generation portion. Can be changed. Therefore, similar to the embodiment shown in FIG. 77, the length of the laser welded portion (hot spot) is shortened toward the outer side, the resistance value is increased, and the heat generation amount (power) determined by the resistance and the current (Ri ² ) is increased. .

FIG. 98 shows the case where the laser bonding portions are provided at equal intervals as described above (a) and the case where the hot spots 22 are arranged substantially uniformly by changing the arrangement interval of the laser bonding portions (b). ) And. In the case of (a), the hot spot 22 has a radial interval b that increases toward the outer peripheral side with respect to a substantially circumferential interval a, but in the case of (b), a ′ vs b ′.
Can be approximately equal.

[0110]

According to the first aspect of the present invention, the current is concentrated in the local heat generating portion which is locally connected so as to be able to conduct electricity, and heat is generated.
Since the power consumption is reduced and heat is locally generated, the heat capacity is reduced, the temperature rising time is shortened, and an electrically heated catalytic device with good thermal efficiency can be obtained.

Further, in the second aspect, since the local heat generating portion is provided on the upstream side of the exhaust gas, the downstream portion of the catalyst can be sufficiently heated by utilizing the heat and flow of the exhaust gas, and the entire catalyst can be uniformly heated. There is an effect. According to the third aspect, since the local heat generating portion is provided at the exhaust gas inflow end portion of the catalyst, poisoning caused by the exhaust gas can be prevented and the deterioration of the heating performance due to this can be minimized.

According to the fourth aspect, since the metal foil is locally bonded via the insulating layer, the metal foil is less likely to be displaced and the durability can be improved.
According to the fifth aspect, since the electrodes are continuously joined, the metal foil between the electrodes is more unlikely to shift, the durability can be improved, and the entire current path can generate heat.

According to the sixth aspect, since the corrugated foil is in the shape of a flat foil, the corrugated foil can be easily joined and the local heating portion can be easily formed. According to the seventh aspect, since the flat foil is laid on the joining portion, the joining can be performed easily and the local heat generating portion can be easily formed. In claim 8,
Since the internal space near the local heat generating portion absorbs the thermal expansion of the local heat generating portion, the durability can be improved.

In the ninth aspect, since the connection between the metal case forming the electrode and the metal catalyst carrier is limited to the portion where the local heat generating portion is formed, the current is more likely to concentrate on the local heat generating portion, Power consumption can be reduced. In claim 10,
Since the connection between the center electrode and the metal catalyst carrier is limited to the portion where the local heat generating portion is formed, the current is more likely to concentrate on the local heat generating portion, and the power consumption can be saved.

In the eleventh aspect of the present invention, since the middle part of the center electrode is the insulating part only partially, no current flows in the electrode downstream of the insulating part, and the current is likely to concentrate in the local heat generating part, thus reducing power consumption. At the same time, since the center electrode remains long in the axial direction of the metal catalyst carrier, it becomes easy to connect the metal foil to the center electrode and stack them. In claim 12, since the combination foil forming the local heating portion is formed by joining the corrugated foil and the flat foil, if the joining position or the joining area between them is changed,
The electric resistance value up to the local heat generating portion is changed, and the one having a predetermined electric resistance value can be easily configured.

In the thirteenth aspect, since the corrugated foil side of the combination foil is wound outside, aiming at the valley of the corrugated foil from the outermost periphery,
It is easy to join the adjacent combination foils to each other, which facilitates manufacturing. In claim 14, of the corrugated foil and the flat foil of the combination foil in which the local heat generating portion is located in advance, the foil on the outer side in the laminating direction is cut off, so that the adjoining combination foils are easily joined from the outer side in the laminating direction, and the manufacturing is easy. Become.

According to the fifteenth aspect, since the insulating portions (slits) are provided on the metal foils on both sides of the local heat generating portion, the current does not diffuse and flow to the surroundings by the insulating portion, and the current is concentrated in the local heat generating portion to easily generate heat. Therefore, it leads to reduction of power consumption. Claim 16
Then, since a total of two corrugated foils and a flat foil are locally joined to each other so as to be able to conduct electricity to form a local heat generating portion, it is possible to reduce the heat capacity and shorten the heating time.

In the seventeenth aspect, among the local heat generating portions, the metal heat generating portion closest to the electrode is connected to the electrode so as to be electrically conductive.
The local heat generating portion and the electrode are electrically short-circuited electrically, the uncertain factor of the electric resistance value between the local heat generating portion and the electrode is reduced, and it becomes easy to set the electric resistance value of the entire metal catalyst carrier to a predetermined value. In the eighteenth aspect, since the joining length of the local heat generating portion is changed depending on the formation position of the local heat generating portion, the local heat generating portion having an arbitrary heat generation amount can be easily formed at an arbitrary position.

In claim 19, since the joining of the corrugated foil and the flat foil in the combination foil in the vicinity of the local heat generating portion is made to be a flexible structure more than the portion where the local heat generating portion is not formed, the thermal stress of the local heat generating portion is sufficiently absorbed. At the same time, the metal foil in the portion where the local heat generating portion is not formed is less likely to be displaced, and the durability is improved. In the twentieth aspect, since the local heat generating portion is formed very short in the exhaust gas flow direction, the cross-sectional area in the direction perpendicular to the exhaust gas flow is large, and the contact area with the exhaust gas having a high temperature is large. The temperature rising time can be shortened.

In the twenty-first aspect, since the current is concentrated in the portion left by the slit and the heat is locally generated, the temperature rising time becomes short and the power consumption can be reduced. In claim 22, since the slit is provided in the non-bonding portion with the adjacent metal foil, stress acting on the overlapping contact portion of the metal foils can be avoided, and the insulating foil laminated with the metal foil can be fitted in the slit. Since it is incorporated, the strength of the metal catalyst carrier can be prevented from lowering and the durability can be improved.

[Brief description of drawings]

FIG. 1 is a perspective view showing a metal carrier according to a first embodiment of the present invention.

FIG. 2 is a vertical cross-sectional view of the metal carrier of FIG.

FIG. 3 is a perspective view showing a part of a process of manufacturing the metal carrier of FIG.

FIG. 4 is a vertical cross-sectional view schematically showing the configuration of the entire catalyst device.

FIG. 5 is a vertical sectional view showing an operating state of the metal carrier in the first embodiment.

FIG. 6 is a characteristic diagram showing an effect of the first embodiment.

FIG. 7 is a plan view showing a metal carrier according to a second embodiment.

FIG. 8 is a vertical sectional view showing the operation of the second embodiment.

FIG. 9 is a plan view showing a metal carrier according to a third embodiment.

FIG. 10 is a plan view showing a metal carrier according to a fourth embodiment.

FIG. 11 is a plan view showing a metal carrier according to a fifth embodiment.

FIG. 12 shows a sixth embodiment, (a) is a longitudinal sectional view,
(B) is a plan view.

FIG. 13 is a perspective view showing a process of manufacturing a metal carrier in the seventh embodiment.

FIG. 14 is a plan view showing a metal carrier according to a seventh embodiment.

FIG. 15 is a perspective view showing a catalyst carrier of an eighth embodiment.

FIG. 16 is a perspective view showing a modified example of the catalyst carrier of the eighth embodiment.

FIG. 17 is a perspective view showing a catalyst carrier of a ninth embodiment.

FIG. 18 is a perspective view showing a part of FIG. 17 in an enlarged manner.

FIG. 19 is a plan view showing a modified example of the catalyst carrier of the ninth embodiment.

FIG. 20 is a partially cutaway perspective view of a catalyst carrier according to a tenth embodiment.

FIG. 21 is a diagram showing how a current flows at a local junction of the device of FIG. 20.

22 is a diagram showing how a current flows through a local junction in the device of FIG. 20. FIG.

23 is a vertical cross-sectional view of the device of FIG.

24. When manufacturing the device of FIG. 20, a metallic thin corrugated plate joined to a positive electrode and a flat plate are overlapped and rolled up to form spiral spiral alternating layers, and a honeycomb metallic catalyst carrier is formed. It is a figure which shows a mode that it forms.

FIG. 25 is a graph showing the relationship between the distance from the upstream end and the exhaust gas purification performance of the electrically heated catalyst device.

FIG. 26 is a plan view of an eleventh embodiment in which the heat generating area is limited to the central portion in the radial direction.

FIG. 27 is a plan view of a twelfth embodiment in which the resistance value of the flat plate and the corrugated plate in the portion other than the donut-shaped heat generating region in the middle portion in the radial direction of the catalyst carrier is reduced by the non-local joint portion.

28 is an enlarged view of a non-local joint portion of the flat plate and the corrugated plate of FIG. 27. FIG.

FIG. 29 is a plan view of a thirteenth embodiment in which a region for generating heat is formed in a cross shape around the center electrode.

30 is a schematic cross-sectional view taken along the line AA in FIG.

FIG. 31 shows a fourteenth embodiment in which a heat generating region is provided in a cross shape around the center electrode and at the downstream end of the catalyst carrier,
(A) is a longitudinal sectional view and (b) is a plan view.

FIG. 32 is a partially cutaway perspective view of a fifteenth embodiment in which a plurality of heat generating parts are provided in the exhaust gas flow direction.

33 is a vertical cross-sectional view taken along the line AA of the device shown in FIG.

[Fig. 34] An axial slit is formed in a part of the honeycomb,
It is the perspective view which showed the corrugated board of 16th Example and the flat plate which were made to heat the remaining part, and were wound.

35 is a vertical cross-sectional view of the device made as in FIG. 34.

FIG. 36 is a view showing a state of a seventeenth embodiment in which a part of the corrugated plate is a flat plate for the purpose of facilitating local bonding of the corrugated plate and the flat plate;

FIG. 37 is a diagram showing a state of an eighteenth embodiment in which at least one flat plate is added between the corrugated plate and the flat plate in order to facilitate the local bonding of the flat plate and the flat plate.

FIG. 38 is a perspective view of a nineteenth embodiment in which a tungsten wire heating element is provided on the honeycomb-shaped ceramic carrier.

39 is a cross-sectional view taken along the line AA in FIG.

FIG. 40 is a front view of a catalyst carrier of an electric heating type catalytic converter according to a twentieth embodiment.

41 is a cross-sectional view taken along the line AA in FIG. 40.

FIG. 42 is a front view of a catalyst carrier of an electric heating type catalytic converter according to a twenty-first embodiment.

43 is a sectional view taken along line CC of FIG. 42.

44 is a sectional view taken along line BB of FIG. 41.

45 is a cross-sectional view taken along line DD of FIG. 43.

FIG. 46 is a sectional view taken along line EE of FIG. 43.

[FIG. 47] A schematic cross-sectional view in the axial direction of an electrically heated catalyst according to a twenty-second embodiment.

48 is a partial front view of the catalyst carrier of the embodiment of FIG. 47. FIG.

FIG. 49 is a view showing a part of FIG. 48 in a further enlarged manner.

FIG. 50 is a diagram showing an equivalent circuit of an electric heating type catalyst according to a twenty-second embodiment.

FIG. 51 is a partial front view of the electrically heated catalyst according to the 23rd embodiment.

FIG. 52 is a schematic view showing a method for forming an electrically heated catalyst according to the twenty-fourth embodiment.

FIG. 53 is a front view (a) and a partially enlarged view (b) for explaining a joint portion of the metal foil of the electric heating catalyst of the example.

FIG. 54 is a view showing a laser-bonded state of metal foils of the electric heating catalyst of the example.

FIG. 55 is a front view (a) and an axial sectional view (b) of an electric heating catalyst of the 25th embodiment.

FIG. 56 is an axial sectional view showing a modification of the embodiment of FIG. 45.

FIG. 57 is a front view of an electrically heated catalyst according to a 26th embodiment.

58 (a) and 58 (b) are diagrams showing an equivalent circuit of a heat generating portion of a catalyst carrier.

FIG. 59 is a perspective view of a combination foil composed of flat foil and corrugated foil for explaining the 27th embodiment.

FIG. 60 is a diagram showing a laser-bonded state of metal foils of the electric heating catalyst of the example.

FIG. 61 is a view showing a part of a metal foil of an electrically heated catalyst according to a twenty-seventh embodiment, (a) showing a cut;
(B) is a figure which shows the state which laminate | stacks a metal foil, (c) is a figure which shows a laser joining state.

FIG. 62 is a perspective view showing a part of a metal foil of an electric heating catalyst according to the 28th embodiment.

FIG. 63 is a diagram for explaining a current flow in the example, where (a) shows a case without a break and (b) shows a case with a break.

FIG. 64 is an axial cross-sectional view of an electric heating catalyst according to the 29th embodiment.

FIG. 65 is an equivalent circuit diagram of a heat generating portion of the electric heating catalyst of the example.

FIG. 66 is a perspective view of a flat plate in the example.

FIG. 67 is a perspective view of a corrugated plate in the example.

FIG. 68 is an axial sectional view of an electric heating catalyst according to the 30th embodiment.

FIG. 69 is a perspective view of a flat plate in the same example.

FIG. 70 is a perspective view of a corrugated plate in the example.

FIG. 71 is an axial sectional view of an electric heating catalyst according to the 31st embodiment.

FIG. 72 is a view showing a state in which the metal foil of the electric heating catalyst of the example is developed.

FIG. 73 shows a perspective view (a), a rigid metal foil portion (b), and a flexible metal foil portion (c) of an electric heating catalyst according to the thirty-second embodiment.

FIG. 74 is an axial sectional view of an electric heating catalyst according to the 33rd embodiment.

FIG. 75 is an axial sectional view (a) of the electric heating type catalyst according to the thirty-fourth embodiment, (b) showing a part of the center electrode, and (c) an axial direction sectional view of the electric heating type catalyst of the modified example. Is.

FIG. 76 is a view showing a mode of joining metal foils of the electric heating catalyst of the 35th Example.

FIG. 77 is a partial cross-sectional perspective view showing a part of an upstream end portion of an electric heating catalyst according to the 36th embodiment.

FIG. 78 is a diagram showing the relationship between the length of a hot spot and the resistance value.

FIG. 79 is a diagram showing the relationship between the hot spot heat generation amount and the optimum interval.

[FIG. 80] A front view (a) and an axial sectional view (b) of an electric heating catalyst according to a thirty-seventh embodiment, and an axial sectional view (c) of a modified electric catalyst according to a modification.

81 is a front view of an electric heating type catalyst according to the 38th embodiment. FIG.

82 is a front view (a) and an axial cross-sectional view (b) of an electric heating type catalyst according to a 39th embodiment. FIG.

FIG. 83 is a developed view of the metal foil in the example.

FIG. 84 is a partial perspective view of a metal foil of an electric heating catalyst according to the 40th embodiment.

FIG. 85 is a view of the bridge portion of the metal foil in the same example as seen from three directions.

FIG. 86 is a plan view of an electric heating type catalyst in the example.

87 is a diagram showing a bridge portion by enlarging a part of FIG. 86. FIG.

88 is a case where no bridge portion is formed (a),
It is a figure for demonstrating the effect of (b) when a bridge part is formed like the same Example.

FIG. 89 is a plan view showing one (a) and the other (b) of the metal foil of a pair of the electric heating catalyst according to the forty-first embodiment, and a diagram (c) showing a state of winding the metal foil.

FIG. 90 is a perspective view showing a state of winding the metal foil according to the example.

FIG. 91 is a perspective view showing a joint portion of the metal foil according to the example.

FIG. 92 is a schematic cross-sectional view in the axial direction of the completed catalyst carrier according to the example.

FIG. 93 is a perspective view of a metal catalyst carrier according to a forty-second embodiment.

94 is an enlarged view of portion B in FIG. 93 showing a brazed joint.

FIG. 95 is a front view of a metal catalyst carrier according to a 43rd embodiment.

FIG. 96 is a view showing a part of an end face of the metal catalyst carrier in the example.

FIG. 97 is a view showing an arrangement of hot spots on a metal catalyst carrier in the example.

FIG. 98 shows a hot spot arrangement (a) when the metal foils of the metal catalyst carrier are bonded at equal intervals and a hot spot arrangement (b) when the interval is variable. It

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Catalyst device (whole) 11 ... 1st catalyst device 15 ... Metal carrier 19 ... Center electrode 20 ... Honeycomb-shaped cylinder 21 consisting of metal foil 21 ... Outer cylinder (ground electrode) 22 ... Radial short circuit path 25, 26 ... Power supply 28, 29 ... Annular short-circuit surface 31 ... Spiral-shaped short-circuit path 32, 33 ... Radial-direction short-circuit path 35 ... Randomly distributed short-circuit path 36 ... Radial-direction short-circuit path 43 provided on the end face on the downstream side ... Short circuit 52,53 ... Print heater

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display location B01J 35/04 321 A 8017-4G (31) Priority claim number Japanese Patent Application No. 5-140855 (32) Priority Hihei 5 (1993) June 11 (33) Priority claiming country Japan (JP) (72) Inventor Yoshi ▲ Naga ▼ 14 Iwatani, Shimohakaku-cho, Nishio-shi, Aichi Prefecture Japan Auto Parts Research Institute, Inc. (72) Inventor Yoshihiko Watanabe 14 Iwatani, Shimohakaku-cho, Nishio-shi, Aichi Japan Auto Parts Research Institute, Inc. (72) Inventor Yukihiro Shinohara 14 Iwatani, Shimohakaku-cho, Nishio-shi, Aichi Stocks Japan Auto Parts Research Institute (72) Inventor Yasuyuki Kawabe 14 Iwatani, Shimohakaku-cho, Nishio-shi, Aichi Japan Auto Parts Research Institute, Inc. (72) Inventor Hiroaki Ichikawa Shimohakaku-cho, Nishio-shi, Aichi 14th Tani Japan Automotive Parts Research Institute, Inc. (72) Inventor Yoshi ▲ Kaki ▼ Koji 1 Toyota-cho, Toyota-shi, Aichi Prefecture Toyota Motor Corporation (72) Inventor Tetsuo Nagami 1 Toyota-cho, Toyota-shi, Aichi Address: Toyota Motor Corporation (72) Inventor, Toshihiko Inoka, 14 Iwatani, Shimohakaku-cho, Nishio-shi, Aichi Japan Auto Parts Research Institute (72) Inventor, Hiroshi Hirayama 1-cho, Toyota-cho, Aichi Prefecture Toyota Auto Car Co., Ltd. (72) Inventor Ito ▲ Takashi Akira, Toyota City, Aichi Prefecture, 1st Toyota Town, Toyota Motor Co., Ltd. (72) Inventor, Masakatsu Sanada, Toyota City, Aichi Prefecture 1 Toyota Town, Toyota Motor Co., Ltd. ( 72) Inventor Akihiro Izawa 14 Iwatani, Shimohakaku-cho, Nishio-shi, Aichi Japan Auto Parts Research Institute, Inc.

Claims (22)

[Claims] 1. An electric heating type catalyst device which is heated by energizing a catalyst carrier made of a conductive material, wherein the catalyst carrier is provided with a local heat generating portion locally energizable. Heating catalyst device. 2. The electrically heated catalyst device according to claim 1, wherein the local heat generating portion is provided on the exhaust gas upstream side in the exhaust passage of the internal combustion engine. 3. The electrically heated catalyst device according to claim 1, wherein the local heating portion is provided so as to avoid the exhaust gas inflow end portion. 4. The catalyst carrier is a metal catalyst carrier formed by laminating metal foils with an insulating layer interposed therebetween, and the local heat generating portion is formed by locally bonding the metal foils so that they can be electrically conducted. The electrically heated catalyst device according to claim 1, which is characterized in that. 5. The electric heating type catalyst device according to claim 4, wherein the local heat generating portion is formed as a local current path by connecting electrodes so that they can be continuously energized. 6. The metal catalyst carrier is composed of a corrugated foil having an insulating layer on the surface and a flat foil, and the corrugated foil has a flat foil shape at the joint of the local heat generating portion. Electric heating catalyst device. 7. The metal catalyst carrier is composed of a corrugated foil having an insulating layer on the surface and a flat foil, and a flat foil is further stacked between the corrugated foil and the flat foil at the joint of the local heat generating portion. The electrically heated catalyst device according to claim 4. 8. The electrically heated catalyst device according to claim 4, wherein an internal space is formed in the vicinity of the local heating portion inside the metal catalyst carrier. 9. A metal foil is connected to a center electrode via an insulating layer and wound to form a metal catalyst carrier, and the metal catalyst carrier is housed in a metal case to which the other electrode is connected. The local heating portion is formed only on a part of the metal catalyst carrier in the axial direction, and the connection between the metal catalyst carrier and the metal case is limited to a part of the axial direction. Electric heating type catalyst device. 10. A metal foil is connected to a center electrode via an insulating layer and wound to form a metal catalyst carrier, and the metal catalyst carrier is housed in a metal case to which the other electrode is connected. The local heating portion is formed only on a part of the metal catalyst carrier in the axial direction, and the connection between the metal foil and the center electrode is limited to a part of the axial direction. Heating catalyst device. 11. Viewed from the connection of the center electrode to the power supply,
An insulating part is provided only in the middle of the center electrode so that current does not flow downstream of the part of the axial direction where the local heat generating part is formed, and the connection between the metal foil and the center electrode is part of the axial direction. The electrically heated catalytic device according to claim 10, wherein the electrically heated catalytic device is limited to 12. A metal catalyst carrier formed by providing an insulating layer on a surface of a combination foil, which is obtained by combining and joining a corrugated metal foil and a flat foil, and locally forming the combination foil between the combination foils. 5. The electric heating type according to claim 4, wherein a local heat generating portion is formed by electrically connecting to each other, and a joining position or a joining area between the corrugated foil and the flat foil in the combination foil is arbitrarily changed. Catalytic device. 13. An insulating layer is provided on the surface of a combination foil in which a metallic corrugated foil and a flat foil are combined and joined, and when the insulating layer is wound and laminated on the outside of the corrugated foil, the outermost circumference to the outermost circumference are bonded by a bonding means. 5. The electric heating type according to claim 4, wherein a valley of the corrugated foil of the combination foil and a combination foil adjacent to the outermost combination foil are locally joined so as to be able to conduct electricity to form a local heat generating portion. Catalytic device. 14. A metal catalyst carrier formed by providing an insulating layer on the surface of a combination foil, which is formed by combining and joining a corrugated metal foil and a flat foil, and is a metal catalyst carrier formed by laminating the combination foils. When forming a local heat generating portion that is locally energizable by joining means from the outside, of the combination foil at the position of the local heat generating portion, one of the corrugated foil and the flat foil is laminated on the outer side in the laminating direction. The electrically heated catalyst device according to claim 4, which is cut off. 15. The electrically heated catalyst device according to claim 4, wherein an insulating layer is provided on the metal foil on both sides of the local heat generating portion. 16. A total of two adjacent corrugated foils and flat foils of a metal catalyst carrier in which a metallic corrugated foil having an insulating layer on its surface and a flat foil are alternately laminated are locally energized and joined. The electrically heated catalyst device according to claim 4, wherein a local heating portion is formed. 17. The electricity according to claim 4, wherein the local heating portions are scattered, and the scattered metal foil portion is connected to the electrode so that the metal foil portion closest to the electrode can be energized. Heating catalyst device. 18. The local heating portions are scattered, and the joint length of the local heating portions in the axial direction of the metal catalyst carrier is changed according to the formation position of the local heating portions on the metal catalyst carrier. Item 4. The electrically heated catalyst device according to Item 4. 19. A combination foil in which a corrugated foil and a flat foil are combined and joined together, and the corrugated foil and the flat foil in the combination foil near the local heating portion are joined together in the combination foil in another metal catalyst carrier portion. 5. The electrically heated catalyst device according to claim 4, wherein the number of joints is reduced to form a flexible structure rather than the corrugated foil and the flat foil. 20. The electrically heated catalyst device according to claim 1, wherein the local heat generating portion is formed to be very short with respect to the length of the catalyst carrier in the exhaust gas flow direction in the exhaust passage of the internal combustion engine. 21. The electrically heated catalyst device according to claim 20, wherein a slit is provided in the exhaust gas flow direction of the catalyst carrier, and the carrier part left locally in the slit is used as a local heat generating part. 22. A metal catalyst carrier comprising a metal foil laminated via an insulating layer, wherein the slit is provided at a non-joint portion with an adjacent metal foil, and the insulating layer is fitted in the slit. 22. The electrically heated catalyst device according to claim 21, wherein: