JPH01193013A - Catalyst converter - Google Patents

Abstract

PURPOSE:To make it possible to form a hollow mixing room at the central part of a catalyst carrier by forming a cutout portion spreading from the central part of one side piece on the roll start end of a metal plate to many side pieces in a catalyst carrier which is formed through spirally rolling process of the metal plated coated with catalyst. CONSTITUTION:A catalyst carrier 6 contained in the cylindrical casing 4 of a catalyst converter 2 is constructed by spirally rolling duplicated body consisting of a plane-shaped metal plate 12 coated with catalyst on its surface and backface and corrugated metal plate 14 so as to keep a void for forming an exhaust channel 20. In this case, two metal plates 12, 14 are provided with cut out portion 16 cut in rectangular shape and having a prescribed length 1 and width (w) formed on the central part of the one side pieces 12a, 14a on roll-start end, from the one end pieces 12a, 14a to the other side pieces 12b, 14b on roll-end. During the rolling process, then, a hollow mixing room 18 is formed in the central part of the catalyst carrier 6.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a catalytic converter, and more particularly, to a catalytic converter having a metal catalyst carrier formed by rolling a metal plate coated with a catalyst into a spiral shape. It is related to.

(Prior art) Conventionally, catalysts were coated on the front and back sides of a flat metal plate and a corrugated metal plate, and these metal plates were polymerized and rolled into a spiral shape to form a metal catalyst carrier. A catalytic converter in which this catalyst carrier was held in a casing with its axial direction along the streamline direction of exhaust gas was developed in the 1970s.
This method is known from Japanese Patent No. 2-32753.

(Problem to be Solved by the Invention) Generally speaking, a catalytic converter has a mixing chamber formed inside the converter, and exhaust gas that has been purified by a catalyst carrier disposed upstream of the mixing chamber is mixed. It is known that after mixing in the chamber, the purification efficiency can be effectively improved by purifying the mixture again using a catalyst carrier disposed further downstream.

However, in order to form a mixing chamber in the conventional catalytic converter, a plurality of metal catalyst carriers must be arranged along the axial direction at predetermined intervals. Then, in order to restrict the movement of each catalyst carrier in the axial direction within the casing, annular or other locking members are required, which increases the number of parts and complicates the structure of the catalytic converter. Problems such as reduced productivity arise due to stricter dimensional accuracy control.

The present invention has been made in view of the above circumstances, and its purpose is to provide an economically efficient metal material that can form a mixing chamber inside while preventing a decrease in productivity as much as possible. An object of the present invention is to provide a catalytic converter having a catalyst carrier.

(Means for Solving the Problems) In order to solve the above-mentioned problems, the present invention forms a catalyst carrier by rolling a metal plate coated with a catalyst into a spiral shape with a gap left in between. In a catalytic converter that is held in a casing with its axial direction along the streamline direction of exhaust gas, the metal plate is attached to the metal plate at its winding start end to form a hollow mixing chamber approximately in the center of the catalyst carrier. A notch was provided from the center of one side to the other side at the end of the winding.

(Function) According to the present invention having the above configuration, a notch is provided in the center of one side of the metal plate at the start end of the winding, and is cut out from this side toward the other side of the end end of the winding. Therefore, when a metal catalyst carrier is formed by rolling a metal plate multiple times in a spiral shape, a hollow mixing chamber is integrally formed in the center of the carrier.

(Example) Hereinafter, a preferred example of the catalytic converter according to the present invention will be described in detail based on the accompanying drawings.

In FIG. 1, 2 is a catalytic converter, 4 is a cylindrical casing, and 6 is a metal catalyst carrier housed within the casing 4 and held therein.

The casing 4 has a central portion 4a in its longitudinal direction expanded in diameter so that the cross section is uniformly circular (or elliptical or oval) over a predetermined length; The catalyst carrier 6 is housed in the central portion 4a in close contact with the central portion 4a over its entire length. Further, both sides of the central portion 4a of the casing 4 are each successively reduced in diameter to form a cone shape, and both ends of the catalyst carrier are locked by the cone portions 4b and 4c. Further, an inlet vibe 8 and an outlet vibe 10 are connected to the tips of each cone portion 4b, 4c, respectively.

As shown in FIG. 2, the catalyst carrier 6 is made by superposing a flat metal plate 12 and a corrugated metal plate 14, each coated with a catalyst on the front and back sides, with a gap forming an exhaust gas passage 20. It is formed by multiple roll processing into a spiral shape. At this time, the two metal plates 12, 14 are provided with a wire extending from the negative side 12a, 14a to the end of the winding over a predetermined length β in the center of one side 12a, 14a of each winding start end. A rectangular notch 16 having a predetermined width W is provided in advance toward the other sides 12b and 14b. In other words, each metal plate 12, 14 is formed in advance into a concave shape. For this reason, these metal plates 12.
As shown in FIGS. 1 and 4, a hollow mixing chamber 18 is integrally formed in the central portion of the catalyst carrier 6 after rolling the catalyst carrier 14 into a spiral shape. On the other hand, on the upstream and downstream sides of the mixing chamber 18, as shown in FIG. Exhaust gas purification sections 22 and 24 are formed.

Therefore, in the catalytic converter 2 constructed in this manner, when the catalyst carrier 6 is roll-molded, the mixing chamber 18 is integrally formed therein, so a locking member for locking the catalyst carrier 6 is specially provided. It is not necessary to install a mixing chamber 1 in the catalytic converter 2 with a simple structure without increasing the number of parts.
8 can be provided. Further, since the number of parts is small, it becomes easy to manage the dimensional accuracy of each part, and the variation in the capacity of the mixing chamber 18 between products is minimized. Therefore, productivity can be improved as much as possible, and the quality of assembled products can be made as uniform as possible.

Next, a modified embodiment of the present invention will be described with reference to FIG. 1 and FIGS. 5 and 6.

As shown in the figure, in this modified embodiment, the corrugated metal plate 14A forming the catalyst carrier 6A is superimposed only on the downstream side of the notch 16 of the flat metal plate 12.

Therefore, when the catalyst carrier 6A is formed by rolling these metal plates 12 and 14 in multiple spiral shapes, the mixing chamber 18
The cross section of the exhaust gas purification section 22A on the upstream side is as shown in FIG. The heat capacity is reduced by the absence of the corrugated metal plate.

That is, by doing this, the exhaust gas purification section 2 on the upstream side
The 2A catalyst can be warmed up quickly, thereby improving the purification performance during cold start. In addition, the flow path cross-sectional area (opening area) at the most upstream end of the catalyst carrier 6A
Since this increases, the clogging that occurs here can be reduced as much as possible. Furthermore, since flow path resistance can be alleviated, engine output loss due to exhaust resistance can be reduced.

In addition, in the explanation so far, each metal plate 12.14 (or 14A) is formed by superposing the flat metal plate 12 and the corrugated metal plate 14 (or 14A) and rolling them into a spiral shape. Although the metal catalyst carrier 6 (or 6A) is exemplified with a gap forming an exhaust gas passage 20' therebetween, the present invention is not limited to this. A metal catalyst carrier may also be used, in which an exhaust gas passage is secured by rolling a single metal plate having concavities and convexities into a spiral shape.

(Effects) In summary, according to the present invention, a notch is formed from the center of one side of the catalyst-coated metal plate at the winding start end to the other side at the winding end. When a metal catalyst carrier is formed by rolling a metal plate into a spiral shape, a mixing chamber can be integrally formed inside the catalyst carrier. Therefore, the mixing chamber can be provided in the catalytic converter with a simple structure without particularly providing a locking member for locking the catalyst carrier, and a decrease in productivity can be prevented as much as possible.

[Brief explanation of the drawing]

FIG. 1 is a side sectional view showing a preferred embodiment of the catalytic converter according to the present invention, FIG. 2 is a perspective view of the catalyst carrier shown in FIG. 1 during roll processing, and FIG. 3 is the same as that shown in FIG. 1. FIG. 4 is a cross-sectional view of the catalyst carrier taken along the line IV--IV in FIG. 1, and FIG. 5 is a cross-sectional view of the catalyst carrier taken along the line IV--IV in FIG. A perspective view during molding, and FIG. 6 is a cross-sectional view corresponding to the cross section taken along the line ■--■ of the catalyst carrier in the modified embodiment of FIG. 2...Catalytic converter 4...Casing 6...Catalyst carrier 12...Flat metal plate 12a...One side 12b on the winding start side ...Other side 14 on the winding end side...Corrugated metal plate 14a...One side 14b on the winding start end...Other side 16 on the winding end side... ...Notch 18...Mixing chamber 20...Exhaust gas passage as a gap Patent Applicant: Mazda Co., Ltd. Representative Patent attorney - Kensuke Iro Patent attorney Masatoshi Matsumoto

Claims (1)

[Claims] A catalytic converter in which a catalyst carrier is formed by rolling a metal plate coated with a catalyst into a spiral shape with gaps left in between, and the catalyst carrier is held in a casing with its axial direction along the streamline direction of exhaust gas. In order to form a hollow mixing chamber approximately in the center of the catalyst carrier, the metal plate is provided with:
A catalytic converter characterized in that a notch is provided from the center of one side of the winding start end to the other side of the winding end.