JPS63138113A - Catalyst converter for automobile - Google Patents

Abstract

PURPOSE:To enable provision of capacity characteristics being sufficient enough to allow satisfaction of given demand characteristics, by a method wherein a catalyst carrier is divided into a plurality of parts, and division catalyst carriers are differed in a ratio surface area from each other. CONSTITUTION:A catalyst converter body 1 is provided on both sides with exhaust gas outlet and inlet ports 3 and 2, and is connected to a flange 5 of an exhaust muffler 5 through a flange 4 formed to the one end part. A catalyst carrier serving as a means facilitating retension of exhaust gas is situated in the catalyst converter body 1. In this case, a catalyst carrier is formed such that a plurality of division catalyst carriers S1-Sn are properly combined together. Each of the catalyst carries S1-Sn is formed by ceramic to form a porous substance having continuous void three-dimensional skeleton structure, and the size of each pore of the porous substance and the number of the pores are differed from each other. This constitution enables provision of capacity characteristics being sufficient enough to allow satisfaction of given demand characteristics.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an improvement in a catalytic converter used to efficiently oxidize or reduce harmful components contained in automobile exhaust gas and purify the exhaust gas.

[Circulating technology]

As is well known, catalytic converters are used to purify harmful components in automobile exhaust gas. A catalyst carrier is arranged inside the catalytic converter and comes into contact with the exhaust gas. The first requirement for this catalytic converter is the efficiency of removing harmful components, and the second requirement is that the exhaust efficiency of the engine is not inhibited. These mostly relate to catalyst supports. The first point concerns the specific surface area (surface area/volume) of the catalyst carrier. Since the area is large, the exhaust gas can remain sufficiently in the converter, and as a result, the chemical reaction for purification can be sufficiently carried out, and therefore the purification efficiency is improved. However, the second point is that as the specific surface area of the catalyst carrier becomes larger, the contact area between the exhaust gas and the catalyst carrier becomes larger, and as a result, the flow path resistance becomes larger and the exhaust efficiency decreases. That is, the harmful component removal efficiency and the exhaust efficiency are in a substantially inversely proportional relationship as shown in FIG. 8(A).

In this case, the vertical axis is exhaust efficiency R1, and the horizontal axis is harmful component removal efficiency r
shall be.

The catalytic converters currently in use include those with a single catalyst carrier such as a metal plate rust layer type, a fully curved particle type ceramic honeycomb structure, and recently, ceramic open-cell porous bodies with a three-dimensional skeleton structure. It has also been proposed to have a single catalyst carrier consisting of: This porous ceramic open-cell three-dimensional skeleton structure is produced by foaming soft urethane foam with a predetermined pore size, forming it into the required shape, and then impregnating the foamed urethane foam with liquid ceramic. It is then dried and finally baked to remove only the urethane foam.

None of the catalytic converters described in E above solve the basic relationship between harmful component removal efficiency and exhaust efficiency (inversely proportional relationship), but they can improve exhaust efficiency as much as possible in the mutual relationship of point 1.2 above. It has been found that the catalytic converter using the single open-cell ceramic porous body with a three-dimensional framework structure as the catalyst carrier is the most excellent as a device that can obtain the maximum harmful component removal efficiency without impairing the There is.

[Problem that the invention seeks to solve]

By the way, the required characteristics such as harmful component removal efficiency and exhaust efficiency required for automobiles differ depending on each vehicle type, usage conditions, environment, laws and regulations, and other various conditions. On the other hand, there are performance characteristics such as harmful component removal efficiency and exhaust efficiency that the catalytic converter side has that is applied to each car.

It is desirable to match the performance characteristics of the catalytic converter as much as possible with the characteristics required for the automobile. As shown by the dotted line in FIG. 8(B), it is determined uniformly. However, in Figure 8 (C
) As mentioned above, in the case of the required characteristics required from the automobile side, the required characteristics (indicated by the dashed-dotted line and the dashed-double-dotted line, respectively) depending on the vehicle type, usage conditions, etc. must be mutually satisfied. As a result, the finally required characteristics (indicated by the solid line) are not uniform as shown in FIG. 8(D).

Therefore, in many cases, the required characteristics of harmful component removal efficiency and exhaust efficiency on the automobile side do not match the similar performance characteristics of the catalytic converter applied to each car, and the required characteristics on the automobile side There was also a limit to the capacity characteristics of the catalytic converter that could be met. The difference between such required characteristics and performance characteristics is only widening now that various demands for automobiles are becoming higher and higher, and there is an urgent need for improvement.

By the way, even if you use a single catalyst carrier made of open-celled ceramic porous material with a three-dimensional skeleton structure, which is considered to be the best at present, it is possible to form a single catalyst carrier that has two or more different performance characteristics depending on the required characteristics. Although it seems that the above problems can be solved by doing so, there remain technical problems such as the inability to form layers of different phases during the foaming stage of the urethane foam, making it difficult to implement. .

Therefore, the object of the present invention is to: 1) provide an automotive vehicle using a porous ceramic open-cell three-dimensional framework structure as a catalyst carrier, which has extremely excellent performance characteristics in terms of the mutual relationship between harmful component removal efficiency and exhaust efficiency; Our objective is to provide a catalytic converter that can meet any required characteristics as much as possible, such as the above-mentioned harmful component removal efficiency and exhaust efficiency. The object of the present invention is to provide a catalytic converter that can be easily performed without using particularly advanced technology and can be realized at low cost.

[Means for solving problems]

The present invention solves the conventional problems and takes the following technical means to achieve the object described in J.

That is, in an automobile catalytic converter consisting of a converter casing main body having an exhaust gas inlet and an exhaust port, and a single catalyst carrier disposed within the main body, the catalyst carrier is a ceramic open-cell three-dimensional ceramic converter. Consisting of a skeletal structure, this catalyst carrier is divided into a plurality of parts, and each divided unit catalyst carrier has a different pore size and number of pores per unit length, depending on the automobile to which it is applied. According to the required characteristics of exhaust efficiency and the required characteristics of removal efficiency of harmful components in exhaust gas, the above-mentioned divided unit catalyst carriers that can provide performance characteristics that satisfy those required characteristics are combined and arranged inside. This is an automotive catalytic converter characterized by the following. Therefore, the individual performance characteristics of each divided unit catalyst carrier are determined by the pore size, the number of pores per unit length,
This is determined by factors such as thickness.

[Effect]

Three divided unit catalyst carriers S, s2, each having different performance characteristics in the relationship between exhaust efficiency and harmful component removal efficiency.
Prepare s3. The relationship between these specific surface areas is s, <s2
<s3. By the way, the required characteristics such as a certain harmful component removal efficiency for a certain exhaust efficiency on the automobile side are 0.
is required, each of the above divided unit catalyst carriers S
When t, S2+S3 are used alone in a catalytic converter, as shown in Figure 7 (A) and CB), if there is no one that matches the required characteristic 0 above, the required characteristic is as close to 0 as possible. Select and combine those with characteristics. In this case, as shown in FIG. 7(B), within a certain range, the dividing unit carrier S,
However, in other ranges, the divided unit carrier S3 has the required characteristic close to 0, so these two are selected.

Let's combine them. As a result, as shown in FIG. 7(C), it is easy to obtain a catalytic converter that exhibits performance characteristics that meet the above-mentioned required characteristics 0 required for automobiles as much as possible.

Thus, as shown in FIG. 1, the divided unit catalyst carrier S1
．． Exhaust gas introduced into the main body interior 9 of the catalytic converter equipped with S2 first passes through the divided unit catalyst carriers SI and then through the divided unit catalyst carriers S2. It is a porous body with a three-dimensional skeleton structure made of open cells made of ceramic with a large surface area, and the exhaust gas flow path is complicated, so the exhaust gas passes through it in a turbulent flow.

The effects that exhaust gas receives at each location are not uniform because the properties of each catalyst carrier are different, and the relationship between exhaust efficiency and purification efficiency changes in a variety of ways within a single catalytic converter. be. Therefore, by changing the combination of split unit catalyst carriers.

A single catalytic converter can have various exhaust efficiency and purification efficiency performance characteristics, and can meet any required characteristics.

In other words, the catalytic converter does not have performance characteristics that individually match the required characteristics such as having a certain purification efficiency for a certain exhaust efficiency required by the automobile, but by combining devices with arbitrary performance characteristics, it is possible to improve the catalytic converter. The performance characteristics as a whole will meet the required characteristics required by the automobile side.

〔Example〕

Hereinafter, preferred embodiments of the present invention will be described in detail based on the drawings.

First, a first embodiment will be explained based on FIGS. 1 to 4.

In Fig. 1, ■ indicates a main body of an automobile catalytic converter.This catalytic converter main body 1 has an exhaust gas inlet 3 on one side and an exhaust gas outlet 2 on the other side. A flange 4 formed at portion l' is connected to a flange 5' of an exhaust muffler 5 of an automobile. In this case, the catalytic converter main body 1 is made into a removable cylinder, so nuts and bolts are used as the connecting means. This continuous portion is provided with a sealing means (not shown). When the converter main body 1 and the muffler 5 communicate with each other in this manner, exhaust gas is introduced from the gas inlet 3 as shown by the arrow 7, and while it remains inside the converter main body 9, harmful components in the gas such as CO, l (C, No) are oxidized or reduced by the air introduced by an air introduction means (not shown), and are subsequently discharged from the gas outlet 2 on the other side as shown by arrow 6.

In order to sufficiently carry out the above oxidation or reduction reaction and improve the harmful component removal efficiency (harmful component purification efficiency), a means for making it easier for gas to remain inside the converter main body 1 is required. As a means for this purpose, a catalyst carrier is provided inside the converter main body l as shown in FIG. The catalyst carrier is not a single one but a plurality of divided unit catalyst carriers Sl.
+32.

...-3n, and FIG. 1 shows a case in which it is composed of two divided unit catalyst carriers s, , s2. In addition, each divided unit catalyst carrier s,, s2 is made of ceramic and the second
As shown in Figures (A) to (C), it is a porous body having an open-cell three-dimensional skeleton structure, and as shown in Figure 3, the first step is to foam a soft urethane foam, a second step of cutting into a shape, a third step of liquefying the ceramic raw material, a fourth step of adjusting the viscosity of the liquid ceramic raw material, a fifth step of impregnating the urethane foam with the liquid ceramic raw material, It is formed through a sixth step in which the liquid ceramic raw material is dried and solidified, and a seventh step in which the solidified ceramic raw material is baked to remove the urethane foam.

In addition, each of the divided unit catalyst carriers s, s2 has the same characteristics as shown in FIG. 2 (A) depending on the foaming conditions in the first step or the viscosity conditions in the fourth step.
) and (C), the holes 10 are formed to have different sizes, number of holes per unit length, or thickness. That is,
Each unit catalyst carrier has a different specific surface area. Therefore, although not shown in the drawings, it is also possible to form catalyst carriers with larger or smaller pores than the divided unit catalyst carriers s, s2, with more or fewer pores per unit length, that is, with larger or smaller specific surface areas. be.

Divided unit catalyst carriers s, , s2 constituting the catalyst carrier written as
The number of -3n or the specific surface area of each divided unit catalyst carrier can be freely combined. In this case, depending on the exhaust efficiency required characteristics required by the automobile to which the vehicle is applied and the required characteristics required for the removal efficiency of harmful components in exhaust gas, the combinations are made so as to produce performance characteristics that satisfy these required characteristics.

Therefore, if the required characteristics cannot be met even by combining two divided unit catalyst carriers s, , s2 with different specific surface areas as shown in FIG. 1, three divided units with different specific surface areas as shown in FIG. Catalyst carrier SI+S2. This is done in combination with S3. In this case the side split unit catalyst carriers s,
The arrangement of s2 and s3 is not limited in any way,
Further, in this embodiment, as shown in FIGS. 1 and 4, spaces 8 are provided between the individual divided unit catalyst carriers.

The above divided unit catalyst carriers s,, s2, S3 φ...Sn
As described in 1, since it is formed of a porous body having a three-dimensional skeleton structure of ceramic open cells, the exhaust gas introduced into the catalytic converter main body 1 flows through the divided unit catalyst carriers s, , s2 +33. When passing through each, it passes through a complicated communication channel, which causes turbulence.
By providing the space 8, the flow of the exhaust gas can be rectified once, and it can be smoothly transferred to the next divided unit catalyst carrier, so that the exhaust efficiency is not inhibited more than necessary.

As mentioned above, the space 8 is additionally provided according to the required characteristics required for the automobile, and is not an absolute condition.
When arranging the second unit in the catalytic converter main body l, it is necessary to securely fix it, but in this case, the fixing method or positioning method is not particularly limited. This is achieved by placing a metal O-ring between the carriers and positioning the carrier.

A second preferred embodiment of the second invention described in claim 2 will be described in detail below with reference to FIG. 5.6.

In the second embodiment, as shown in FIG. 5, three divided unit catalyst carriers S1 each having a different specific surface area are provided inside 9 of the catalytic converter main body 1 shown in the first embodiment.

s2. s3 is installed. As described in the first embodiment, the number of divided unit catalyst carriers and the difference in specific surface area of each divided unit catalyst carrier (depending on the size of the pores, the number of pores per unit length, etc.) can be freely selected. and can be combined.

Now, in the second embodiment, the individual divided unit catalyst carriers s,, s
Nickel is a copper-based material for controlling the flow rate of exhaust gas between each of 2 and 33.

A metal perforated plate made of alloy such as chromium or molybdenum is provided. Moreover, this metal porous plate alone has the function of a catalyst carrier.

Figure 5 shows the space between the divided unit catalyst carriers s, , s2, and S2+
A case is shown in which two metal porous plates 11a and llb are provided between S3. The metal porous plate 11a,
As shown in FIG. 6(A) and FIG. 6(B), llb has different hole sizes and numbers of holes, and although not shown, it can be formed other than the metal porous plates 11a and 11b. Individual split unit catalyst carrier S1.

s2. What kind of metal perforated plate should be combined during s3?
Similar to the case of combining split unit catalyst carriers, combinations are made to produce running characteristics that meet the requirements of the automobile to which it is applied, such as exhaust efficiency and efficiency of removing harmful components from exhaust gas (purification efficiency). Ru. Moreover, these metal porous plates 11
a, llb are divided into unit catalyst carriers S,, s2, s3
5, they are placed in contact with each other without providing the space 8 shown in the first embodiment, as shown in FIG.

Next, I will explain the series of operations.

Three divided unit catalyst carriers s,, s2 + each having different performance characteristics in the relationship between exhaust efficiency and harmful component removal efficiency.
Prepare 53. The diagram in FIG. 7(B) shows this. The relationship between these specific surface areas is S! ＞S2＞
33. By the way, when the required characteristic 0 such as having a certain harmful component removal efficiency for a certain exhaust efficiency on the automobile side is required as shown in FIG. When S3 is used alone in a catalytic converter, if there is no one that matches the above required characteristic O as shown in FIGS. 7(A) and (B), the performance characteristic is as close to the required characteristic 0 as possible. Select the one that has
Combine. In this case, as shown in FIG. 7(B), since the divided unit carrier S1 has the required characteristic close to 0 in a certain range and the divided unit carrier S2 has the required characteristic close to 0 in another range, these two are selected and combined. As a result, as shown in FIG. 7 CC'), a catalytic converter can be easily obtained that can meet the above-mentioned required characteristic 0 required for automobiles as much as possible. FIG. 7(C) is a performance diagram of the entire catalytic converter as a result of the above-mentioned selected combinations.

Thus, as shown in FIG. 1, the divided unit catalyst carrier S,
, S2, the exhaust gas introduced into the interior 9 of the catalytic converter main body 1 first passes through the divided unit catalyst carriers SI and then through the divided unit catalyst carriers S2. is a porous body with a three-dimensional skeleton structure of ceramic open cells each having a different specific surface area,
The exhaust gas flow path is complicated, and therefore the exhaust gas passes through it in a turbulent flow. At this time, a space 8 is provided between the divided unit catalyst carriers s, s2. In this case, the exhaust gas is once rectified by this space 8, so that it can smoothly enter the divided unit catalyst carrier S2. When such a metal porous plate is provided, the metal porous plate itself acts as a catalyst carrier to allow the exhaust gas to remain.

The effect that such exhaust gas receives at each location is not uniform because the properties of each catalyst carrier are different.

The relationship between exhaust efficiency and purification efficiency changes in a variety of ways within a single catalytic converter. Therefore, by changing the combination of divided unit catalyst carriers, a single catalytic converter can have various performance characteristics of purification efficiency with respect to exhaust efficiency, and can meet any required characteristics.

In other words, the catalytic converter does not have performance characteristics that individually match the required characteristics such as having a certain purification efficiency for a certain exhaust efficiency required by the automobile, but by combining devices with arbitrary performance characteristics, it is possible to improve the catalytic converter. The performance characteristics as a whole will meet the required characteristics required by the automobile side.

〔Effect of the invention〕

As can be seen from the above, the present invention provides a catalytic converter that has performance characteristics that can appropriately meet the required characteristics such as a certain purification efficiency (toxic component removal efficiency) for a certain exhaust efficiency required by an automobile. can do.

In other words, the characteristics required for automobiles, such as exhaust efficiency and purification efficiency, vary depending on various conditions.On the other hand, porous bodies made of ceramic with an open-cell three-dimensional skeleton structure are excellent as catalyst carriers for use in catalytic converters. Due to technical problems, it was difficult to vary the specific surface area in parts of a single catalytic converter, so only uniform performance characteristics could be exhibited. The catalyst carrier is divided into multiple parts, and each divided unit catalyst carrier has a different specific surface area, so that performance characteristics can be achieved that satisfy the required characteristics such as exhaust efficiency and harmful component removal efficiency required by the automobile to which it is applied. This is because the above-mentioned divided unit catalyst carriers are appropriately combined.

Therefore, it can be easily implemented without using particularly advanced technology. A suitable combination of the divided unit catalyst carriers can be easily determined experimentally. Furthermore, according to the second invention described in claim 2, a metal porous plate is provided between the divided unit catalyst carriers on each side, so that the combination of a plurality of divided unit catalyst carriers alone cannot be used. Even when special required characteristics are required, by changing the metal porous plate to one with a different pore diameter, number of holes, etc., it is possible to exhibit more diverse performance characteristics, and the catalyst can meet the above-mentioned special required characteristics. converter can be provided.

As described above, the present invention has the advantage that it is easy to produce because it is only necessary to prepare split unit catalyst carriers with different performance characteristics in advance, and there is no need to prepare only specific ones that have been thoroughly investigated in advance. It is something.

[Brief explanation of the drawing]

The attached drawings Figures 1 to 7 are examples, and Figures 1 to 4 are examples.
The figure shows the first embodiment, and FIGS. 5 to 7 show the second embodiment, and FIG. 1 is a sectional view showing the main body of the catalytic converter.
Figure 2 (A) is a cross-sectional view taken along the line x-X of the divided unit catalyst carrier, Figure 2 (B) is an enlarged view of the same part, and Figure 2 (C) is the same
A line sectional view, FIG. 3 is a manufacturing process diagram of a divided unit catalyst carrier, FIG. 4 is a sectional view showing another example of a catalytic converter main body, and FIG. 5 is a catalytic converter main body in a second embodiment. 6(A) is a sectional view taken along the line V-V showing the perforated metal plate, FIG. 6 CB) is a sectional view taken along the line W-W showing the perforated metal plate,
Figure 7 (A) is a required characteristic diagram for the automobile, (B) is a performance characteristic diagram of the divided unit catalyst carrier, and (C) is a performance characteristic diagram of the entire catalytic converter after selecting the combination. Figure 8 (A) is a diagram to explain that exhaust efficiency and harmful component removal efficiency are inversely proportional to each other, Figure 8 (B) is a diagram of the performance characteristics uniformly determined for a conventional single-layer catalyst carrier, Figure 8 (C
) is a diagram showing that there are various characteristics required by automobiles,
Fig. 8 (CD) is a diagram showing an example of a desirable characteristic diagram to be obtained. Catalytic converter body, 290. Exhaust gas outlet #9 Miko F 389. Exhaust gas inlet. s, , S2 , S3 , , are divided unit catalyst carriers. Rod 2 Garden (A) Fu 2 Garden (C) Rod 3 Flash porous catalyst 4gL, (Basic 4 Garden Fu 5 Ward Graduation 6 Ward (A) Fu 6 @ (B) Rod 7 Doctor (A) *Shutyu Yusame moaning rod 7 reasons (C) Haya 8 Kuni A, moving to the earpiece 8 A C Shoulder harm anreito yohei procedure? fi official book (method) % formula % 2 Name of invention Automotive catalyst Converter 3 Relationship with the case of the person making the amendment Patent applicant Address: 35 Teratani Shinden, Iwata City, Shizuoka Prefecture Name: Suzuki
Kenji 4 Agent 〒220

Claims (2)

[Claims] (1) An automotive catalytic converter consisting of a converter casing body having an exhaust gas inlet and an exhaust port, and a catalyst carrier disposed within the body, wherein the catalyst carrier has an open-cell three-dimensional skeletal structure made of ceramics. This catalyst carrier is divided into a plurality of parts, and each divided unit catalyst carrier has a different pore size and number of pores per unit length, and the exhaust efficiency of the automobile to which it is applied is different. In accordance with the required characteristics and the required characteristics for the removal efficiency of harmful components in exhaust gas, the divided unit catalyst carriers described above are combined and arranged internally so that the ability characteristics that satisfy those required characteristics can be obtained. An automotive catalytic converter featuring: (2) A catalytic converter for an automobile consisting of a converter casing main body having an automobile exhaust gas inlet and an exhaust port, and a catalyst carrier disposed within the main body, the catalyst carrier having an open-cell three-dimensional skeletal structure made of ceramic. This catalyst carrier is divided into a plurality of parts, and each divided unit catalyst carrier has a different pore size and number of pores per unit length, and the exhaust efficiency of the automobile to which it is applied is different. According to the required characteristics and the required characteristics for removal of harmful components in exhaust gas, the above-mentioned divided unit catalyst carriers are combined and arranged inside so that the ability characteristics that satisfy those required characteristics can be obtained. A catalytic converter for an automobile, characterized in that a metal porous plate is disposed between each of the divided unit catalyst carriers.