JPH02265653A - Carrier matrix for exhaust gas purifier - Google Patents

Abstract

PURPOSE:To provide an excellent heat resistance and surface strength and improve the characteristic of imparting resistance to thermal fatigue and the purification efficiency of exhaust gases by making larger the thickness of the arranged at least in contact with a cylindrical metal honeycomb case than those of the other parts. CONSTITUTION:A honeycomb structure 1 is small in wall thickness and a case 2 is larger in wall thickness than the honeycomb structure. Of corrugated plates 3 or flat plates 4 in the honeycomb structure 1, the parts A arranged at least in contact with the case 2 are made larger in thickness than the other parts B such as central parts and smaller than the case 2. Such structure offers an excellent heat resistance and surface strength improving the characteristic of imparting resistance to thermal fatigue and the purification efficiency of exhaust gases. Also, difference in deformation amt. between the honeycomb structure and the case are decreased stepwise, thereby preventing the peeling-off.

Description

DETAILED DESCRIPTION OF THE INVENTION "Field of Industrial Application" The present invention relates to a supporting body for an exhaust gas purification device. That is, the present invention relates to a supporting body to which a catalyst is attached in a catalytic converter or the like that purifies exhaust gas from an automobile engine or the like.

"Prior Art" A honeycomb structure with a case has conventionally been used for such a supporting body. That is, as this type of support base, one is used that is composed of a roll-shaped honeycomb structure to which the catalyst is attached, and a cylindrical case in which the honeycomb structure is housed.

And as a honeycomb structure of such a supporting matrix,
There were two types: the first was made of ceramics, and the second was made of metal with a uniform thickness.

"Problems to be Solved by the Invention" By the way, the following problems have been pointed out in such conventional supporting bodies for exhaust gas purification devices.

First, an example using the first ceramic honeycomb structure is as follows.

In other words, this supporting matrix has a problem in that the ceramic honeycomb structure is easily damaged due to shocks and vibrations applied from the outside, or due to differences in deformation from the case due to heating and cooling during use.

As a countermeasure to this problem, a cushioning material has been interposed between the ceramic honeycomb structure and the case. However, since such a supporting body uses a buffer material, there are problems such as high cost, poor cleaning efficiency of exhaust gas, and increased ventilation resistance.

Next, an example using the second metal honeycomb structure having a uniform wall thickness is as follows. First, this supporting matrix does not require the above-mentioned cushioning material, and the problems pointed out in the above-mentioned example using the ceramic honeycomb structure are solved.

However, the thickness of the metal honeycomb structure and the metal case are extremely different, with the former being uniformly thin and the latter being uniformly thick. Furthermore, the structure of the former is that a corrugated sheet material and a flat sheet material are wound into a roll, whereas the latter is a single sheet that is cylindrical.

Due to such extreme changes in wall thickness and structural differences at the joints between the honeycomb structure and the case, the coefficients of thermal expansion and contraction of the honeycomb structure and the case are significantly different. Therefore, when this support base is used for purifying exhaust gas, the amount of expansion and contraction of the two due to repeated heating and cooling, that is, the amount of deformation due to expansion and contraction, will be greatly different.

Based on this difference in the amount of deformation, the bonding strength between the honeycomb structure and the case decreases and peeling occurs, cracks occur in the honeycomb structure, the attached catalyst peels off, and eventually clogging occurs. Occasionally this occurred. As described above, the support matrix using the metal honeycomb structure has a problem in terms of heat resistance strength, that is, thermal fatigue characteristics, and this also causes a problem in that the cleaning efficiency of exhaust gas is deteriorated.

This point was pointed out in the conventional example.

The present invention has been made in view of the above-mentioned circumstances to solve the problems of the conventional example, and is made by increasing the thickness of at least the portion of the metal honeycomb structure that contacts the case. The purpose of the present invention is to propose a support base for an exhaust gas purification device that has excellent heat resistance and strength, improves exhaust gas purification efficiency, prevents damage, reduces ventilation resistance, and is cost effective. do.

"Means for Solving the Problem" The technical means of the present invention to achieve this object are as follows.

This carrier for the exhaust gas purification device has the following honeycomb structure and case.

A honeycomb structure consists of a metal corrugated sheet material in which a band-shaped wave-shaped unevenness is continuously bent and a flat band-shaped metal plate material, which are alternately wound to form a roll shape. attached.

The case has a cylindrical shape and the honeycomb structure is housed therein, and its wall thickness is thicker than the corrugated plate material and the flat plate material of the honeycomb structure.

The corrugated plate material or the flat plate material of the honeycomb structure is formed so that at least a portion in contact with the case is thicker than other portions.

"Function" Since the supporting body for the exhaust gas purification device according to the present invention is constituted by such means, it functions as follows.

The exhaust gas is purified by passing through the purification device and reacting with the catalyst attached to the carrier.

Firstly, the thickness of this support matrix is thicker at least in the portion of the honeycomb structure that contacts the case than in other portions. This portion functions as a buffer between the honeycomb structure and the case, which have extremely different wall thicknesses, and eliminates the extreme change in wall thickness at the joint between the two.

Therefore, even if heating and cooling are repeated through use, the difference in the amount of expansion and contraction deformation between the honeycomb structure and the case is gradually alleviated. In other words, the heat transfer and the expansion/contraction difference between the two are absorbed and adjusted gradually, rather than abruptly, by interposing this thickened portion. As a result, this supporting matrix has excellent heat resistance and strength, improves thermal fatigue properties, and also improves exhaust gas cleaning efficiency.

Secondly, this supporting body uses a metal honeycomb structure and a case, and no cushioning material is required between the two.

Therefore, the difference in the amount of deformation between the supporting base bodies is alleviated, and even if shocks, vibrations, etc. are applied from the outside, damage to the honeycomb structure is prevented. In addition, since no buffering material is used, the exhaust gas cleaning efficiency is improved from this point of view as well, and there is no increase in ventilation resistance, which is advantageous in terms of cost.

"Example" The present invention will be described in detail below based on the example shown in the drawings. FIG. 1 is an explanatory front view showing an embodiment of the present invention.

First, the structure and the like will be explained in order of the outline of the supporting body and its wall thickness.

The outline of the carrier is as follows.

This supporting body for the exhaust gas purification device consists of a honeycomb structure 1 and a case 2. First, honeycomb structure 1
A metal corrugated sheet material 3 in which a band-shaped corrugated unevenness is continuously bent and a flat metal sheet material 4 in a band-like shape are wound alternately to form a roll, and a catalyst is coated. It is attached by etc.

The corrugated sheet material 3 is formed by corrugating metal foil or the like using a corrugating machine or the like to form a predetermined bend.

The honeycomb structure 1 shown in the figure is made of metal M each having a strip shape.
A corrugated sheet material 3 and a flat sheet material 4 made of aluminum are used, and are formed into a roll shape such as a circle or an ellipse by winding them alternately from a fixed center, overlapping them, and winding them multiple times. Corrugated sheet material 3
The top and the outside of the valley are joined to the flat plate material 4 by brazing filler metal or the like.

In this way, each space of the corrugated plate material 3 is divided into independent spaces by the flat plate material 4, thereby forming a honeycomb structure 1 which is a planar assembly of hollow columnar cells 5. The corrugated plate material 3 and the flat plate material 4 constitute the respective cell walls, and the catalyst is attached thereto.

The case 2 is a pipe-shaped outer cylinder, that is, an outer frame formed by processing a flat plate. That is, the case 2 has a cylindrical shape such as a circle or an ellipse, and the honeycomb structure 1 is inserted and housed therein, and the two are joined by a brazing material or the like. Further, the case 2 is thicker than the corrugated plate material 3 and the flat plate material 4 of the honeycomb structure l.

The outline of the supporting matrix is as follows.

Next, let's talk about the wall thickness.

In the supporting matrix, the honeycomb structure 1 has a thin wall thickness, and the case 2 has a thicker wall thickness. The corrugated plate material 3 or the flat plate material 4 of the honeycomb structure 1 is at least connected to the case 2.
The thickness of the portion A in contact with the case 2 is thicker than the portion B at the center thereof, and thinner than the case 2.

In the illustrated example, only the portion A in contact with the case 2, that is, the outermost circumference of the flat plate 4 that is joined to the case 2, is formed to have a large thickness.

However, the present invention is not limited to this, and various other embodiments can be considered as follows.

First, by placing the corrugated sheet material 3 on the outside of the flat sheet material 4, contrary to the illustrated example, the corrugated sheet material 3 is placed in the portion A that contacts the case 2, and the thickness of the corrugated sheet material 3 is may be made thicker than the other portion B. Second, in addition to increasing the wall thickness only to the part that contacts the case 2, that is, only the outermost circumference as specified, we also increase the thickness of the outer circumference in the vicinity of the adjacent 22.3 circumference several times according to this. The wall thickness may be increased. Thirdly, both the corrugated plate material 3 and the flat plate material 4 may have a predetermined outer circumference thickened as described above.

Fourthly, the predetermined outer periphery of the part A, etc. in contact with the case 2 does not suddenly become thicker in a stepwise manner than the other parts;
The wall thickness of the other portions B may gradually change from that of the other portions B.Fifth, the portion A in contact with the case 2
Rather than integrally forming a predetermined outer periphery of a piece with a thickness that is thicker than the other part B, two or three pieces of the same thickness as the other part B are overlapped and joined. Therefore, it is also possible to use a material whose wall thickness is particularly thick.

Regarding the wall thickness, it is like this.

The above is the explanation of the configuration, etc.

The operation etc. will be explained below.

Exhaust gas from an automobile engine or the like is purified by passing through a purification device and reacting with a catalyst attached to a carrier. That is, the exhaust gas is purified by passing through each cell 5 of the honeycomb structure 1 of the support base and reacting with the catalyst attached to the corrugated plate material 3 and flat plate material 4 that constitute the cell walls.

Now, in this supporting matrix, the following 1st and 2nd results are obtained.

First, in this support matrix, at least the portion A of the honeycomb structure 1 that is in contact with the case 2 is thicker than the other portion B. This portion A functions as a buffer between the honeycomb structure 1 and the case 2, which have extremely different wall thicknesses. As a result, extreme changes in wall thickness at the joint between the two are eliminated.

Therefore, even if the honeycomb structure 1 and the case 2 are used for purifying exhaust gas and repeatedly heated and cooled, the difference in the amount of expansion and contraction deformation between the honeycomb structure 1 and the case 2 is gradually alleviated.

In other words, the difference in heat transfer and shrinkage between the two is absorbed by the presence of the thicker portion A, and is adjusted gradually rather than abruptly.

In this way, the honeycomb structure 1, case 2, etc.
Peeling, cracking, exfoliation, clogging, etc. do not occur, and this support matrix has improved heat resistance and strength, improving thermal fatigue properties and improving exhaust gas cleaning efficiency.

Secondly, this supporting body uses a metal honeycomb structure 1 and a case 2, and there is no need for a cushioning material between them as used in the conventional example.

Therefore, because the difference in the amount of deformation between the honeycomb structure 1 and the case 2 is alleviated, this supporting body is not susceptible to external shocks and vibrations, unlike the conventional case made of ceramic. Damage to the honeycomb structure 1 is also prevented. Also, since no buffering material is used, the cleaning efficiency of exhaust gas is improved from this point of view as well, and the honeycomb structure 1
There is no increase in ventilation resistance in each cell 5, and the cost is also excellent.

"Effects of the Invention" As explained above, the support base for the exhaust gas purification device according to the present invention is made by increasing the thickness of at least the part of the metal honeycomb structure that contacts the case, thereby achieving the following effects: Demonstrates the effect of

First, it has superior heat resistance and strength, and has improved thermal fatigue properties, as well as improved exhaust gas purification efficiency.

In other words, the difference in the amount of deformation between the honeycomb structure and the case is gradually alleviated, so the bonding strength between the two is improved, separation is prevented, and cracks do not occur in the honeycomb structure.
The adhering catalyst is also prevented from peeling off, and clogging is reliably avoided.

Second, damage is prevented, ventilation resistance is reduced, and the cost is excellent.

In other words, a metal honeycomb structure is used, and there is no cushioning material interposed between it and the case, which improves exhaust gas purification efficiency and prevents damage to the honeycomb structure. , there is no increase in ventilation resistance, and it is excellent in terms of cost.

In this way, the problems that existed in this type of conventional example are completely eliminated, and the effects of the present invention are remarkable and great.

[Brief explanation of drawings]

FIG. 1 is an explanatory front view showing an embodiment of a supporting body for an exhaust gas purification device according to the present invention. 1... 2... 3... 4... 5... A... B... Honeycomb structure case Corrugated plate material Flat plate material Part in contact with cell case Other parts

Claims (1)

[Scope of Claims] A metal corrugated plate material in which a band-shaped corrugated unevenness is continuously bent and a band-shaped flat metal plate material are alternately wound to form a roll shape, and a catalyst a honeycomb structure to which is attached; a cylindrical case in which the honeycomb structure is housed and whose wall thickness is thicker than the corrugated plate material and the flat plate material of the honeycomb structure; A support base for an exhaust gas purification device, characterized in that the corrugated plate material or the flat plate material has a wall thickness thicker at least in a portion in contact with the case than in other portions.