JPH0215332B2 - - Google Patents

Description

Detailed Description of the Invention A. Object of the Invention (1) Industrial Field of Application The present invention is directed to a cylindrical shell formed by welding together circumferential ends of a pair of shell halves each having an arcuate cross section. A plurality of catalyst carriers supporting a catalyst while allowing gas flow are housed and arranged on the same axis at intervals, and each catalyst carrier is placed on both axial end faces of each catalyst carrier. The present invention relates to a method of assembling a catalytic converter in which elastic rings for elastically holding the converter are abutted from both ends in the axial direction.

(2) Prior Art Conventionally, in such a catalytic converter, as shown in FIG. 5, a plurality of annular positioning grooves 26 protruding outward in the radial direction are provided at positions spaced apart in the axial direction of the shell 25. The catalyst carrier 2, which has elastic rings 13 in contact with the peripheral edges of both axial end faces thereof, is fitted into the positioning grooves 26.

(3) Problems to be Solved by the Invention Incidentally, the elastic ring 13 is compressed when fitting into the positioning groove 26 and holds the catalyst carrier 2 with its elastic force, but the elastic ring 13 is If it is too much, the catalyst carrier 2 may be damaged. For this reason, it is necessary to strictly define the axial length l1 of the positioning groove 26 and the length l2 of the catalyst carrier 2, but this is actually difficult in terms of production technology.

In addition, the purification characteristics of a catalytic converter in which a plurality of catalyst carriers 2 are arranged is greatly influenced by the spacing l3 between each catalyst carrier 2, but in the conventional type, since the shell 25 is pressed, the positioning groove is 26
Since the accuracy of the interval l4 cannot be expected to be very high, and the position of the catalyst carrier 2 is unstable as mentioned above,
The interval l3 is also unstable.

Further, the shell 25 has a constriction due to the positioning groove 26, and in order to ensure durability that can withstand stress concentration on the constriction, the thickness of the shell 25 must be relatively large. .

The present invention has been made to solve the above-mentioned conventional problems, and makes it possible to maintain a constant spacing between each catalyst carrier even if the dimensional accuracy of the shell is made relatively rough, and also prevents damage to the catalyst carriers. It is an object of the present invention to provide a method for assembling a catalytic converter that prevents the above problems and also provides durability and reliability even when the thickness of the shell is made relatively small.

B. Structure of the Invention (1) Means for Solving the Problems In the method of the present invention, a set plate is interposed between the elastic rings that contact the opposing end surfaces of mutually adjacent catalyst carriers, and a plurality of catalyst carriers are arranged. Arranged in a straight line, elastic rings are also brought into contact with the end faces of each catalyst carrier at both ends in the arrangement direction,
Construct an interpolation aggregate for storage in the shell,
Both ends of the insert assembly in the axial direction are fixed to the inner surfaces of both shell halves while the insert assembly is compressed with a constant load in the axial direction, and both shell halves are welded together to form a shell. I did it like that.

(2) Effect By compressing the insert assembly with a constant load in the axial direction, each catalyst carrier is held by the elastic rings on both sides under a constant load, and the elastic rings and the set By increasing the dimensional accuracy of the plates, the spacing between each catalyst carrier becomes constant. Moreover, since both ends of the interpolation assembly are fixed to both shell halves and both shell halves are joined, each catalyst carrier is housed within the shell while maintaining a constant interval between them, and the shell is also simply cylindrical. The thickness of the plate can be relatively thin.

(3) Embodiments Below, embodiments of the present invention will be explained with reference to the drawings. First, in FIG. 1 showing an embodiment of the present invention, this catalytic converter is installed, for example, in the middle of the exhaust system of a vehicle internal combustion engine. shall be done;
A plurality of catalyst carriers 2, 2, for example, a pair of catalyst carriers 2, 2 are housed and arranged coaxially within a casing 1 with an interval between them. Both catalyst carriers 2, 2 support the catalyst while allowing the flow of exhaust gas, and are formed in a cylindrical shape, and as the exhaust gas flows through these catalyst carriers 2, 2, the HC in the exhaust gas is reduced. Harmful components such as , CO and NOx are removed by promoting oxidation and reduction reactions.

The casing 1 is made up of end cones 4 and 5 welded to both ends of a shell 3, and flanges 6 and 7 are fixed to both end cones 4 and 5 for joining to the middle of an exhaust pipe.

In FIG. 2, the shell 3 is formed into a cylindrical shape by welding shell halves 8 and 9 having semicircular cross sections to each other. That is, joint flanges 10 and 11 that abut each other are integrally provided at both ends in the circumferential direction of both shell halves 8 and 9.
Shell 3 is formed by abutting and welding 11.

A ring-shaped peripheral surface protection member 12 made of an elastic material is interposed between the outer peripheral surface of each catalyst carrier 2, 2 and the inner peripheral surface of the shell 3, respectively. This peripheral surface protection member 12 is formed by, for example, knitting thin metal wires in a mesh shape, and the catalyst carrier 2,
It functions to prevent the destruction of 2.

Elastic rings 13, 13 are in contact with the peripheral edges of opposing end surfaces of both catalyst carriers 2, 2, and a set plate 14 is placed between these elastic rings 13, 13.
is interposed. The set plate 14 is formed into a ring shape with a substantially U-shaped cross section that opens inward.

Further, elastic rings 13, 13 having the same shape as the elastic ring 13 are in contact with the peripheral edges of the end faces of both the catalyst carriers 2, 2 on the sides that are separated from each other. End face set plates 15, 15 fixed to the inner surfaces of both axial ends of the
supported by.

These end face setting plates 15, 15 are formed into a ring shape with a substantially L-shaped cross section, and are welded and fixed to the inner surface of the shell 3 at the position where each elastic ring 13 is compressed with a constant load. . As a result, each catalyst carrier 2, 2 is held with a constant elastic force from both ends in the axial direction.

Each part housed in the shell 3 is assembled into an insert assembly 16 for assembling the catalytic converter.
Configure. That is, the interpolation assembly 16 has elastic rings 1 on both sides of the central set plate 14.
3. The catalyst carrier 2, the elastic ring 13 and the end face set plate 15 are brought into contact with each other in this order.

Next, the operation of this embodiment will be explained.
When assembling the catalytic converter, the insert assembly 16 is prepared as shown in FIG.
Press and compress with a constant load. This compressive force is set to such an extent that damage to each catalyst carrier 2 due to the elastic force exerted by each elastic ring 13 can be avoided.

With the interpolation assembly 16 compressed in this way, the shell halves 8 and 9 are placed over the interpolation assembly 16 from both sides, and both end faces of the interpolation assembly 16 are set on the set plate 1.
5 and 15 are welded and fixed to the inner surfaces of both axial ends of the shell halves 8 and 9, and the two shell halves 8 and 9 are welded together to form the shell 3, and then pressed using pressing jigs 17 and 18. Release the pressed state.

When welding the end face set plates 15, 15 to the shell halves 8, 9,
A plurality of holes are bored at intervals in the circumferential direction at both ends of the end face setting plates 15, 15 from the outside.
Alternatively, spot welding may be used. Moreover, the central set plate 14 may be welded to both shell halves 8, 9, or may be left free relative to both shell halves 8, 9.

Thereafter, the end cones 4 and 5 having flanges 6 and 7 are welded to both axial ends of the shell 3, thereby completing the assembly process of the catalytic converter.

According to such an assembly procedure, the catalyst carriers 2, 2 can be held under a constant load, regardless of the processing accuracy of the shell 3, that is, the shell halves 8, 9, and the length of the catalyst carriers 2, 2. can,
Damage to the catalyst carriers 2, 2 can be prevented.

In addition, since the set plate 14 and each elastic ring 13 are formed by single-piece processing, high-precision processing is possible. The interval between them is always constant. Therefore, it is easy to set the interval to a value that can maximize the purification performance.

Further, the longitudinal dimensional accuracy of the shell 3 and the shell halves 8, 9 is relatively rough because both ends of the interpolation assembly 16 are welded and fixed to the shell halves 8, 9, which is advantageous in terms of production technology. be.

Furthermore, since the shell 3 is formed in a cylindrical shape, there is no constriction, and stress concentration does not occur, so that the plate thickness can be relatively thin.

FIG. 4 shows another embodiment of the present invention, and parts corresponding to those in the previous embodiment are given the same reference numerals.

The shell 3' is formed by welding together a pair of shell halves 8', 9', and these shell halves 8', 9' have a shoulder 2 at one end of the semi-cylindrical parts 19, 20.
Semi-conical portions 23 and 24 are integrally connected via 1 and 22.

In this embodiment, the interpolation assembly 16' is formed by omitting the end face set plate 15 at one end of the interpolation assembly 16 in the previous embodiment, and when assembled, the interpolation assembly 16' is The elastic ring 13 is brought into contact with the shoulders 21 and 22 of both shell halves 8' and 9', and the insert assembly 16' is pressed with a constant load from the other end. While maintaining the pressed state, the end face set plate 15 on the other end side of the insert assembly 16' is welded and fixed to the shell halves 8' and 9', and
The shell 3' is formed by welding and joining the two shell halves 8' and 9' to each other, and after releasing the pressed state, the end cone 5 is welded and joined to the other end of the shell 3' to complete the assembly process. finish.

This embodiment can also provide the same effects as the above-mentioned embodiments.

In each of the above embodiments, a catalytic converter having a pair of catalyst carriers has been described, but the present invention is also applicable to a converter having three or more catalyst carriers.

C. Effects of the Invention As described above, according to the method of the present invention, a plurality of catalyst carriers are arranged in a straight line by interposing a set plate between the elastic rings that contact the opposing end surfaces of mutually adjacent catalyst carriers. Elastic rings are also brought into contact with the end faces of each catalyst carrier at both ends in the arrangement direction to form an interpolated assembly to be housed in the shell, and the interpolated assembly is compressed with a constant load in the axial direction. In this state, both ends of the insert assembly in the axial direction are fixed to the inner surfaces of both shell halves, and both shell halves are welded together to form a shell. The carrier can be held under an appropriate load, the production technology is easy, quality can be stabilized, costs can be reduced, and damage to the catalyst carrier can be prevented. Further, the distance between the catalyst carriers can be kept constant, and the purification performance can be improved. Furthermore, the shell can be made into a simple cylindrical shape, thereby preventing the occurrence of stress concentration, so that the plate thickness can be made relatively thin, reducing overlap and reducing costs.

[Brief explanation of drawings]

1 to 3 show one embodiment of the present invention, in which FIG. 1 is a longitudinal cross-sectional side view of a catalytic converter, and FIG.
The figures are a cross-sectional view taken along the line -- of FIG. 1, FIG. 3 is a vertical cross-sectional view showing the assembled state, FIG. 4 is a vertical cross-sectional side view of a catalytic converter according to another embodiment of the present invention, and FIG. 5 is a conventional technique. FIG. 2... Catalyst carrier, 3,3'... Shell, 8,
8', 9, 9'... Shell half body, 13... Elastic ring, 14... Set plate, 16, 16'...
interpolation aggregate.

Claims (1)

[Claims] 1 A pair of shell halves 8 having an arcuate cross section,
In a cylindrical shell 3; 3' formed by welding the circumferential ends of 9; 8', 9' to each other, a plurality of catalyst carriers 2, 2 supporting a catalyst are mutually arranged to allow gas flow. are stored and arranged on the same axis with intervals,
In a method of assembling a catalytic converter, elastic rings 13 for elastically holding each catalyst carrier 2, 2 from both ends in the axial direction are brought into contact with each other on both axial end faces of each catalyst carrier 2, 2. A plurality of catalyst carriers 2, 2 are arranged in a straight line by interposing a set plate 14 between the elastic rings 13 which are in contact with the opposite end faces of the catalyst carriers 2, 2 adjacent to each other, and each of the catalyst carriers 2, 2 is arranged in a straight line. catalyst carrier 2,
Elastic rings 13 are also brought into contact with the end faces of the shells 3; 16' to be housed in the shell 3;
6; 16' is compressed with a constant load in the axial direction, and both ends of the insert assembly 16; 16' in the axial direction are fixed to the inner surfaces of the two shell halves 8, 9; A method of assembling a catalytic converter, characterized in that shell halves 8, 9; 8', 9' are welded together to form a shell 3; 3'.