JPH07251079A - Exhaust gas purification catalyst metal carrier and manufacturing method - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a metal carrier including a honeycomb body which is free from metal fatigue and damage due to heat. A catalyst for exhaust gas purification, comprising a honeycomb body 3 provided in the middle of an exhaust pipe 1 of an internal combustion engine and formed by laminating a flat plate and a corrugated plate, and an outer cylinder 4 in which the honeycomb body 3 can be installed. The metal carrier 3 is characterized in that an annular heat insulating layer 5 is provided in a portion on the exhaust gas inflow side of the honeycomb body 3 which is separated from the central axis by a predetermined distance. Thus, immediately after the internal combustion engine is started, the exhaust gas flows into the honeycomb body 3 through the exhaust pipe 1 and the inside of the honeycomb body 3 is heated, but the heat insulating layer 5 provided at a predetermined portion causes a portion around the heat insulating layer 5 of the honeycomb body 3. Is difficult to transfer heat to. Therefore, the honeycomb body 3
It is possible to prevent an excessive temperature rise of the outer peripheral portion 4c on the exhaust gas inflow side, and it is possible to prevent thermal deterioration.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a metal carrier for an exhaust gas purification catalyst and a manufacturing method.

[0002]

2. Description of the Related Art A conventional metal carrier is disclosed in, for example, JP-A-3-
80939. This is Figure 8
Which is a metal carrier 101 as shown in FIG. 1, and is formed by stacking a flat plate and a corrugated plate and winding them in a roll shape.
2 and an outer cylinder 103 that press-fits the honeycomb body 102 and is coaxially arranged on the outer periphery of the honeycomb body 102. FIG. 9 shows a DD cross section of FIG. 8. The honeycomb body 102 is formed by stacking a flat plate and a corrugated plate and winding them in a roll shape so that the wall surface 104 has a larger area than the wall surface of the flat plate. In addition, a catalytic material such as Pt, Pd, or Rh is uniformly carried on the wall surface 104 of the honeycomb body 102.

This metal carrier 101 is arranged in the middle of an exhaust passage 105 connected to an internal combustion engine (not shown), and exhaust gas is discharged from the internal combustion engine side when the internal combustion engine is started.
It is made to flow into 02. Then, the wall surface 104 of the honeycomb body 102 is heated by the heat of the exhaust gas, and when the temperature reaches a predetermined temperature, the catalytic substance carried on the wall surface 104 reaches the activation temperature, and a reaction for purifying harmful substances in the exhaust gas is started. , Purify exhaust gas. At this time, since the area of the wall surface 104 of the honeycomb body 102 is relatively large, the wall surface 1
It is possible to easily contact the exhaust gas with the exhaust gas 04, and to appropriately purify the exhaust gas.

[0004]

When the honeycomb body 102 has the above-described structure, the exhaust gas enters the honeycomb body 102 immediately after the internal combustion engine is started, and the heat of the exhaust gas causes the wall surface 104 of the honeycomb body 102 to move. Be heated. At this time, along with the flow velocity distribution of the exhaust gas in the honeycomb body 102, the central portion A of the radial cross section on the exhaust gas inflow side of the honeycomb body 102.
However, since the flow velocity and the flow rate of the exhaust gas are higher than those of the outer peripheral portion B, the central portion A of the honeycomb body 102 rises to the activation temperature of the catalytic substance fastest.

FIG. 10 is a diagram showing the temperature distribution in the honeycomb body when the internal combustion engine is idle approximately 14 seconds after the exhaust gas has flowed in. The left side of FIG. 10 is the exhaust gas inflow side and the horizontal axis is the axial direction of the honeycomb body. And the vertical axis represents the radial length of the honeycomb body. On the exhaust gas inflow side, the central portion A of the radial cross section of the honeycomb body has a higher exhaust gas flow rate than the outer peripheral portion B, so the temperature rises faster than the outer peripheral portion B, but the central portion A has a flow velocity of the inflowing exhaust gas. Since it is fast, heat is sent to the outflow side on the right side of FIG. 9 together with the exhaust gas, and more heat in the central portion A is transferred to the outflow side than to the outer peripheral portion B.

As the center portion A reaches the activation temperature,
The catalytic substance carried on the honeycomb body wall surface 104 starts the reaction to start purification of the exhaust gas. When the exhaust gas is purified, reaction heat is generated by the purification reaction, and the honeycomb body wall surface 104 is further heated and becomes higher than the temperature of the exhaust gas after a predetermined time. FIG. 11 is a diagram showing the temperature distribution in the honeycomb body 102 when the internal combustion engine is idle, approximately 50 seconds after the exhaust gas has flowed in. The display of the horizontal axis and the vertical axis of FIG. 11 is the same as that shown in FIG. Since the flow velocity is relatively high in the vicinity of the central axis of the honeycomb body 102, that is, in the vicinity of the horizontal axis in FIG. 11, heat is caused to flow to the outflow side of the honeycomb body 102 together with the exhaust gas, and a substantially uniform temperature distribution is exhibited.

However, the outer peripheral portion B of the honeycomb body 102
With respect to, the flow velocity of the inflowing exhaust gas is slower than that in the central portion A. Therefore, although the amount of heat taken to the outflow side together with the exhaust gas is small and the reaction heat is conducted from the central portion A to be heated, the amount of heat taken to the exhaust gas is small because the flow velocity of the inflowing exhaust gas is slow. Thus, as shown in FIG. 11, the temperature of the outer peripheral portion B on the exhaust gas inflow side is further increased. For example, the time change of the temperature of the honeycomb radial cross section at a distance of 10.125 mm in the axial direction from the exhaust gas inlet of the honeycomb body is represented as shown in FIG. 12
As can be seen from the figure, about 3 after the exhaust gas flows into the honeycomb body
The outer peripheral portion B becomes higher in temperature than the central portion A after 0 seconds.

The central portion P of the radial cross section on the outflow side of the central portion A is heated because the heat is conducted together with the exhaust gas from the central portion A and reaches the activation temperature of the catalytic substance,
Since the harmful substances in the exhaust gas are purified in the center part A,
At the outflow side central portion P, the purifying action does not occur as much as at the inflow side central portion A. Therefore, the reaction heat associated with the purifying action is not generated, so that the temperature of the central portion P does not become higher than that of the central portion A. Therefore, the heat conducted to the outer peripheral portion Q of the central portion P is smaller than the heat conducted to the outer peripheral portion B from the central portion A. That is, the temperature rises more markedly in the outer peripheral portion B on the exhaust gas inflow side of the honeycomb body.

On the wall surface 104 of the honeycomb body 102, as the temperature rises, the wall surface 104 also expands. When the honeycomb body 102 is provided by being press-fitted into the outer cylinder 103, or when the honeycomb body 102 is provided with a slight gap between the honeycomb body 102 and the outer cylinder 103 so as to come into contact with the outer cylinder when the honeycomb body 102 thermally expands, the honeycomb body 102 Since the expansion of the outer tube 102 is restricted by the outer tube 103, the outer tube 102 cannot expand beyond a predetermined amount. However, since the wall surface 104 continues to be heated, the wall surface 10 shown by the solid line in FIG.
4 receives the force of expansion and causes plastic deformation as shown by the broken line. Next, when an internal combustion engine (not shown) is stopped, the exhaust gas is not supplied to the honeycomb body 102, so that the purification effect of the exhaust gas does not occur and the honeycomb body 102 is cooled. Along with this, the honeycomb body 102 begins to shrink,
The central portion A that has not undergone plastic deformation is elastically restored and returns to its original state, but the outer peripheral portion B that has undergone plastic deformation cannot be elastically restored. As a result, the difference in the amount of deformation is concentrated on the boundary between the outer peripheral portion B that has undergone plastic deformation and the central portion A that has not caused plastic deformation, and accumulates as stress. Figure 1
When the contacting portion R between the flat plate 104a and the corrugated plate 104b is brazed in 3, the stress is remarkably accumulated.

Further, as shown in FIG. 14, at least the flat plate on the exhaust gas inflow side S of the honeycomb body 102 and the corrugated plate are brazed so that the honeycomb body 102 is not press-fitted into the outer cylinder 103, or Even if the body 102 expands, it does not contact the outer cylinder 103, that is, the sealing material 10
Even when the honeycomb body 102 is fixed via 7, the expansion of the wall surface 104 of the honeycomb body 102 occurs. Since the expansion of the wall surface 104 is restricted at the joint point R by brazing the flat plate 104a and the corrugated plate 104b in FIG. 13, the outer peripheral portion is more likely to be heated over a predetermined temperature and is more likely to be plastically deformed than the central portion. When the outer peripheral portion undergoes plastic deformation, after the engine is stopped, when the honeycomb body is cooled, the central portion elastically restores but the outer peripheral portion cannot elastically restore. Therefore, the amount of deformation at the boundary between the central portion A and the outer peripheral portion B is reduced. Differences are concentrated and accumulated as stress. When this stress concentration is performed over a predetermined number of times, the wall surface 104 cannot withstand this stress and the honeycomb body 1
There was a problem of damaging 02.

The present invention has been made in view of the above problems, and is to reduce the heat transfer from the central portion of the radial cross section to the outer peripheral portion on the exhaust gas inflow side of the honeycomb body as compared with the conventional one.
Alternatively, another object is to prevent the temperature of the outer peripheral portion from rising above a predetermined value by radiating the heat of the outer peripheral portion of the honeycomb body on the exhaust gas inflow side.

[0012]

A metal carrier according to claim 1 of the present invention for solving the above-mentioned problems is provided in the middle of an exhaust passage of an internal combustion engine, and is formed by laminating a flat plate and a corrugated plate. A metal carrier for an exhaust gas purification catalyst, comprising a honeycomb body and an outer cylinder into which the honeycomb body can be provided, characterized by comprising a heat insulating layer on the exhaust gas inflow side of the honeycomb body.

A method of manufacturing a metal carrier according to a second aspect of the present invention comprises a step of forming a notch in a predetermined portion of a corrugated plate, and a step of stacking the corrugated plate and a flat plate and winding them in a roll to form a honeycomb body. And a step of coaxially providing the honeycomb body internally in the outer cylinder.

The metal carrier according to claim 3 of the present invention is provided in the middle of the exhaust passage of an internal combustion engine, and has a honeycomb body formed by laminating a flat plate and a corrugated plate, and an outer body in which the honeycomb body can be internally provided. An exhaust gas purifying catalyst metal carrier including a cylinder, characterized in that a heat dissipation means is provided on the outer periphery of the exhaust gas inflow side of the honeycomb body.

[0015]

The function of the metal carrier for exhaust gas purifying catalyst according to claim 1 of the present invention will be described. Immediately after starting the internal combustion engine, the exhaust gas flows into the metal carrier through the exhaust passage. Due to the distribution of the flow rate of the exhaust gas in the exhaust passage, the central portion of the radial cross section is heated by the heat of the exhaust gas on the exhaust gas inflow side of the honeycomb body where the flow rate of the exhaust gas is the largest. After the temperature of the wall surface of the honeycomb body is raised to a predetermined temperature, it becomes the activation temperature of the catalyst substance carried on the wall surface of the honeycomb body, and purification of the exhaust gas is started. The reaction heat accompanying the purification of the exhaust gas further heats the inside of the honeycomb body to raise the temperature.

While the engine is operating, exhaust gas is supplied into the honeycomb body at any time, and the catalytic substance purifies the exhaust gas. Therefore, heat is conducted from the exhaust gas inflow side of the honeycomb body to each part.
However, since the heat insulating layer is formed on the exhaust gas inflow side of the honeycomb body, heat is difficult to be conducted from the heat insulating layer to the outer peripheral portion of the honeycomb body on the exhaust gas inflow side.

The operation of the method for producing a metal carrier for an exhaust gas purification catalyst according to claim 2 of the present invention will be described. A notch is provided at a predetermined portion of the corrugated plate, and then the corrugated plate is overlapped with the flat plate and wound into a roll to form a honeycomb body. This can be easily obtained by forming a notch when molding the corrugated plate. After the honeycomb body is formed, the notch portion becomes a void. The position of the notch is adjusted so that the void is formed at a predetermined portion on the exhaust gas inflow side of the honeycomb body, which is separated from the central axis by a predetermined distance. In this way, it becomes possible to easily manufacture a metal carrier provided with a heat insulating layer composed of voids at appropriate positions.

The operation of the metal carrier for exhaust gas purifying catalyst according to claim 3 of the present invention will be described. Immediately after starting the internal combustion engine, the exhaust gas flows into the metal carrier through the exhaust passage.
The honeycomb body in the metal carrier is heated by the heat of this exhaust gas, and after the temperature rises to a predetermined temperature, it becomes the activation temperature of the catalyst substance carried on the wall surface of the honeycomb body, and purification of the exhaust gas is started. The temperature of the inside of the metal carrier further rises due to the reaction heat accompanying the exhaust gas purifying action. At this time, heat is conducted from the central part of the radial cross section to each part on the exhaust gas inflow side of the honeycomb body. Since the flow velocity of the exhaust gas at the outer peripheral portion of the honeycomb body on the exhaust gas inflow side is low, the heat transferred to the outer peripheral portion of the honeycomb body on the exhaust gas inflow side is difficult to be conducted to the exhaust gas outflow side of the honeycomb body. However, since heat is taken by the heat radiation means provided on the outer periphery of the honeycomb body on the exhaust gas inflow side, the outer peripheral portion of the honeycomb body on the exhaust gas inflow side does not reach a certain temperature or higher.

[0019]

EXAMPLE A first example of the present invention will be described below. FIG. 1 is a front view showing the overall structure of the metal carrier 2. Reference numeral 1 is an exhaust passage connected to an internal combustion engine (not shown) and has an inner diameter of 2r '.
2 is a metal carrier connected to the exhaust pipe 1 by welding at x, 3 is a honeycomb body disposed inside the metal carrier 2, and 3a is an end face into which exhaust gas flows. Further, 4 is an outer cylinder in which the honeycomb body 3 is installed, 5 is provided on the exhaust gas inflow side of the honeycomb body 3, and the distance r from the central axis is substantially the same as the radius r ′ of the exhaust pipe 1. A void portion which is a heat insulating layer is shown. FIG. 2 is a sectional view taken along line CC of FIG.
The voids 5 are formed by rolling the honeycomb body 3 in a roll shape.
It is formed in an annular shape at a position separated from the central axis by a distance r. It should be noted that the central portion, which is partitioned along the extension of the outer periphery of the exhaust pipe 1 and is the central portion in the radial direction near the central axis of the honeycomb body 3, is 3b, and the periphery of the void 5 is the outer peripheral portion 3c.

The operation of the first embodiment will be described below with reference to FIGS. 1 and 2. Exhaust gas flows into the metal carrier 2 from the left side of FIG. When the exhaust gas flows in, the end surface 3 of the metal carrier 2
Although it is introduced from a, the temperature of the wall surface of the central portion 3b is higher than that of the outer peripheral portion 3c due to the exhaust gas because it easily flows into the central portion 3b of the radial cross section on the exhaust gas inflow side and the flow velocity is high. Get higher Since the exhaust gas continuously flows in from the exhaust pipe 1, when the internal combustion engine starts, the temperature gradually rises and reaches a predetermined temperature, and the activation temperature of the catalyst substance carried on the wall surface of the central portion 3b of the honeycomb body 3 is reached. The action of purifying exhaust gas such as CO begins.

When the exhaust gas purifying action such as CO oxidation starts, the reaction heat of the exhaust gas purifying action further raises the temperature of the wall surface of the honeycomb body 3 and becomes higher than the exhaust gas temperature. Exhaust gas is supplied into the honeycomb body 3 at any time during engine operation, and the exhaust gas is purified by the catalytic substance, so that heat is conducted to each part of the honeycomb body 3. However, since the void portion 5 which is a heat insulating layer is formed around the central portion 3b of the honeycomb body 3, it is difficult to conduct heat to the outer peripheral portion 3c.

FIG. 3 shows an axial length of 120 mm and a diameter of 80.
Fig. 3 shows the temperature distribution inside the honeycomb body about 50 seconds after the inflow of exhaust gas when a cylindrical honeycomb body of mm was connected to an exhaust pipe having an inner diameter of about 50 mm. Reference numeral 5 indicates a portion where a void is provided. As a comparative example, FIG. 11 shows a temperature distribution of a honeycomb body having the same configuration except that the void portion 5 is not provided. Comparing FIG. 3 with FIG. 11, it is possible to prevent an excessive temperature rise in the outer peripheral portion B of the honeycomb body on the exhaust gas inflow side. As a result, it becomes possible to prevent thermal deterioration of the inner wall 3d of the honeycomb body due to the conventional excessive temperature rise.

Further, as can be seen from FIG. 11, an excessive temperature rise occurs from the exhaust gas inflow port toward the outflow side up to about 20 mm and outside the radius of 25 mm of the exhaust pipe. Therefore, it is preferable to form the annular void portion 5 at a position 20 mm from the exhaust gas inflow side toward the outflow side and 25 mm from the central axis. The honeycomb body 3 of the present embodiment is formed by winding a flat plate and a corrugated plate in a roll shape, but the present invention is not limited to this, and is formed by stacking and laminating the flat plate and the corrugated plate. Even if a honeycomb body is used, the same effect can be obtained. Further, the annular void portion 5 of the present embodiment has a substantially circular shape, but is not limited to this, and a polygonal shape such as a triangle, a quadrangle or a pentagon, or a star shape has the same effect. . In addition to this, it is possible to raise the wall surface of the honeycomb body to the activation temperature of the catalyst early after the internal combustion engine is started by providing the above-mentioned void portion 5, that is, in the honeycomb 14 seconds after the inflow of exhaust gas. It can be seen from FIG. 4 showing the temperature distribution in the body and FIG. 10 under the same conditions using the conventional honeycomb body.

Further, since the heat insulating layer is the void, even if the wall surface of the honeycomb body is heated by the temperature of the exhaust gas to cause thermal expansion, the void has an effect of absorbing and relaxing the deformation. Further, the thermal conduction can be reduced as compared with the conventional metal carrier by spraying and coating alumina on the inner wall of the honeycomb body at the above-mentioned void portion or by providing a layer of ceramic fiber.

Another form of the first embodiment is a metal carrier 9 shown in FIG. In this metal carrier 9, the honeycomb body 3 is joined to the outer cylinder 4 on the exhaust gas outflow side via a seal material 10. A flat plate and a corrugated plate are brazed on at least the wall surface T of the honeycomb body 3 on the exhaust gas inflow side, and the honeycomb body 3 is formed on the exhaust gas inflow side of the honeycomb body 3.
An annular notch 5 is provided at a position separated from the central axis of the above by a predetermined distance. With the shape as shown in FIG. 5, it is possible to obtain the same effect as the metal carrier 2 having the shape shown in FIG.

The second embodiment of the present invention will be described below. FIG. 6 shows the flat plate 6 and the corrugated plate 7 before forming the honeycomb body. This flat plate 6 is 4.25 m in the vertical direction and 120 m in the horizontal direction in FIG.
It is a rectangle with a size of m. The corrugated plate 7 has a substantially rectangular shape with dimensions of 4.25 m in the vertical direction and 120 mm in the horizontal direction in FIG. 3, 160 mm in the vertical direction and 25 mm in the horizontal direction.
The rectangular notch is provided.

The flat plate 6 and the corrugated plate 7 are stacked and then wound in a roll shape in the vertical direction of FIG. At this time, the flat plate 6 and the corrugated plate 7
A brazing material is applied to a predetermined portion between the flat plate 6 and the corrugated plate 7 by this brazing material at a portion in contact with each other. As a result, a honeycomb body having a heat insulating layer composed of voids at predetermined positions is formed as shown in FIG. Next, this honeycomb body is inserted so as to be coaxially arranged in the outer cylinder to form a metal carrier. In this way, it becomes possible to easily manufacture the metal carrier provided with the heat insulating layer as shown in FIGS. 1 and 2.

The third embodiment of the present invention will be described below. FIG. 7 shows the overall construction of the third embodiment, and 8 is a cooling water passage as a heat radiating means provided at a predetermined position on the outer periphery of the honeycomb body 3 on the exhaust gas inflow side. The cooling water passage is connected to a cooling water supply means (not shown), and the cooling water supply means can supply the cooling water into the cooling water passage 8.

Next, the operation of the third embodiment will be described below. After starting the internal combustion engine (not shown), the honeycomb body 3 is heated by the heat of the exhaust gas flowing from the engine side. When heated to a predetermined temperature, the catalyst substance carried on the wall surface 3d of the honeycomb body 3 reacts, and purification of exhaust gas such as CO starts. The honeycomb body 3 is further heated by the reaction heat due to the exhaust gas purifying action. At this time, the central portion 3b of the radial cross section on the exhaust gas inflow side of the honeycomb body 3 has a relatively large flow rate of the exhaust gas and a high flow velocity, so that it is flown together with the exhaust gas to the outflow side and does not rise above a predetermined temperature.

However, since the flow rate of the exhaust gas in the outer peripheral portion 3c on the exhaust gas inflow side of the honeycomb body 3 is relatively small,
The heat of the outer peripheral portion 3c does not flow to the outflow side and the temperature rises. At this time, the cooling water is supplied into the cooling water passage 7 by the cooling water supply means (not shown), and the cooling water does not take heat to heat the outer peripheral portion 3c too much. Therefore, the temperature of the outer peripheral portion 3c does not exceed a certain temperature. . In this way, it is possible to prevent the outer peripheral portion 3c of the honeycomb body 3 from being damaged by heat, and it is possible to appropriately purify the exhaust gas. The present embodiment is not limited to this, and in addition to this, even if a cooling fin as a heat radiating means is provided at the position of the cooling water passage 7 and the heat of the outer peripheral portion 3c of the honeycomb body 3 is radiated, the same effect can be obtained. The effect of can be obtained.

[0031]

As described in detail above, according to the metal carrier of the exhaust gas purifying catalyst of claim 1 of the present invention, the central axis of the honeycomb body is provided on the exhaust gas inflow side of the honeycomb body provided inside the metal carrier. A ring-shaped heat insulating layer is provided at a position separated by a predetermined distance from. This heat insulating layer reduces the amount of heat conducted from the central portion of the radial cross section to the outer peripheral portion on the exhaust gas inflow side of the honeycomb body as compared with the conventional case, thereby preventing an excessive temperature rise of the outer peripheral portion on the honeycomb body exhaust gas inflow side. . As a result, it is possible to prevent metal fatigue deterioration of the honeycomb wall surface due to heat of the outer peripheral portion of the honeycomb body on the exhaust gas inflow side and damage of the plate due to thermal stress.

According to the method for producing a metal carrier for an exhaust gas purifying catalyst according to claim 2 of the present invention, a honeycomb body is formed by forming a notch at a predetermined portion of a corrugated sheet and stacking the corrugated sheet on a flat plate and winding the cut sheet in a roll shape. . Next, the formed honeycomb body is provided inside the outer cylinder to form a metal carrier. By this method, it is possible to easily manufacture the metal carrier in which the space layer is provided in the predetermined portion which is separated from the central axis of the metal carrier by the predetermined distance on the exhaust gas inflow side of the honeycomb body.

According to the metal carrier of the exhaust gas purifying catalyst of the third aspect of the present invention, the heat dissipation means is provided on the outer periphery of the exhaust gas inflow side of the honeycomb body provided inside the metal carrier. By this heat radiating means, the heat of the outer peripheral portion of the honeycomb body conducted from the radial center portion on the exhaust gas inflow side of the honeycomb body is taken and the heat is released through the outer cylinder. Can be prevented.

[Brief description of drawings]

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

FIG. 2 is a sectional view taken along line CC of FIG.

FIG. 3 uses the honeycomb body of the first embodiment of the present invention,
It is a figure which shows the temperature distribution inside a honeycomb body about 50 second after an exhaust gas inflow.

[Fig. 4] Fig. 4 is a diagram showing the use of the honeycomb body of the first embodiment of the present invention.
It is a figure which shows the temperature distribution inside a honeycomb body about 14 seconds after inflowing exhaust gas.

FIG. 5 is a front view showing another shape of the honeycomb body of the first embodiment of the present invention.

FIG. 6 is a diagram illustrating a flat plate and a corrugated plate before forming a honeycomb body according to the second embodiment of the present invention.

FIG. 7 is a front view showing the overall structure of the metal carrier according to the third embodiment of the present invention.

FIG. 8 is a front view showing the overall configuration of a conventional metal carrier.

9 is a sectional view taken along line DD of FIG.

FIG. 10 is a diagram showing a temperature distribution inside the honeycomb body about 14 seconds after the inflow of exhaust gas, using the honeycomb body of the conventional technique.

FIG. 11 is a diagram showing a temperature distribution inside the honeycomb body about 50 seconds after the inflow of exhaust gas, using the honeycomb body of the conventional technique.

[Fig. 12] Fig. 12 is a view showing a time change of a temperature in the vicinity of an exhaust gas inlet of the honeycomb body using the honeycomb body of the conventional technique.

FIG. 13 is a front view showing an overall configuration of another shape of a conventional metal carrier.

FIG. 14 is an enlarged view of the wall surface of the honeycomb body as viewed from the axial direction.

[Simple explanation of the sign]

 DESCRIPTION OF SYMBOLS 1 Exhaust pipe 2 Metal carrier 3 Honeycomb body 3a Exhaust gas inflow side end face 3b Exhaust gas inflow side radial center 3c Exhaust gas inflow side radial outer periphery 3d Honeycomb body wall 4 Outer cylinder 5 Gap 6 Flat plate 7 Corrugated plate 8 Cooling Water passage

Continuation of the front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display location B01D 53/86 ZAB F23J 15/00

Claims (3)

[Claims] 1. A metal for an exhaust gas purifying catalyst, which is provided in the exhaust passage of an internal combustion engine and includes a honeycomb body formed by laminating a flat plate and a corrugated plate, and an outer cylinder in which the honeycomb body can be provided. The metal carrier for an exhaust gas purification catalyst, which is a carrier and is provided with a heat insulating layer on the exhaust gas inflow side of the honeycomb body. 2. A step of forming a notch in a predetermined portion of a corrugated plate, a step of stacking the corrugated plate and a flat plate and rolling them into a roll to form a honeycomb body, and the honeycomb body being coaxially placed in an outer cylinder. A method of manufacturing a metal carrier for an exhaust gas purification catalyst, comprising the step of: 3. A metal for an exhaust gas purifying catalyst, which is provided in the middle of an exhaust passage of an internal combustion engine and includes a honeycomb body formed by laminating a flat plate and a corrugated plate, and an outer cylinder in which the honeycomb body can be provided. The exhaust gas purifying catalyst metal carrier, wherein the exhaust gas purifying catalyst is provided with a heat radiating means on the outer periphery of the honeycomb body on the exhaust gas inflow side.