JPH0452419Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a catalytic converter used in a dual exhaust system of an automobile.

[Prior Art] Structures of catalytic converters used in dual exhaust systems that suppress interference between exhaust gases are disclosed in, for example, Japanese Utility Model Application Publications No. 104714/1983, No. 16312/1988,
It is disclosed in Japanese Utility Model Application No. 58-130017.

In the above-mentioned Japanese Utility Model Application Publication No. 55-104714, the catalytic converter (catalyst carrier) is placed in the exhaust pipe with a double pipe structure, and the area from the dual manifold to the front tube becomes a complete dual exhaust system. ing. On both front and rear end surfaces of the catalyst carrier,
A groove is formed into which a partition (inner pipe) for partitioning the exhaust gas passage is fitted. The groove and the partition come into contact with each other to prevent the catalytic converter from moving in the axial direction.

In the honeycomb type catalyst device for exhaust purification disclosed in Japanese Utility Model Application Publication No. 16312/1982, a spacer is interposed between the outlet end of the exhaust manifold and the honeycomb type catalyst, and each space is separated by a partition wall of the exhaust manifold. An opening corresponding to the exhaust passage is formed. A sealing member is attached to the spacer to tightly contact the end face of the honeycomb catalyst to seal the periphery of the opening.

The dual exhaust purification device using a monolith catalyst disclosed in Japanese Utility Model Application Publication No. 58-130017 has an inlet immediately upstream of the inlet of the monolith catalyst that guides the exhaust gases flowing into the purification device to the monolith catalyst without mixing them. A partition wall is provided. Furthermore, an outlet partition wall is provided immediately downstream of the outlet of the monolithic catalyst to dually exhaust the exhaust gases flowing out from the monolithic catalyst without mixing them.

However, in the catalytic converter of the above-mentioned Japanese Utility Model Publication No. 55-104717, grooves are formed on both front and rear end surfaces of the catalyst carrier to reliably prevent interference of exhaust gas, so when the inner tube thermally expands, This causes a problem in that stress is concentrated in the grooves, damaging the end faces of the catalyst carrier and reducing the durability of the catalytic converter.

In addition, in a structure in which partition walls are provided near the inlet and exit of the catalyst, as in the dual exhaust system of Utility Model Application Publication No. 58-130017, it is difficult to position the carrier and the partition, and the tip of the partition and the end face of the carrier It is easy to create gaps between them. Therefore, a large amount of exhaust gas leaks from this gap, making it impossible to reliably prevent exhaust gas interference within the catalytic converter.

By the way, as in Utility Model Application Publication No. 58-16312,
In a structure where the exhaust gas inlet is provided only on one side of the catalytic converter case, the carrier and other components can be inserted from one side, making assembly relatively easy. In a dual exhaust system catalytic converter in which two inlets and two exhaust gas outlets are provided in advance, the number of parts in the case increases, the ease of assembling the catalytic converter becomes poor, and the cost increases.

Therefore, the applicant previously proposed a dual exhaust system catalytic converter that can protect the catalyst carrier from external forces, eliminate the gap between the end face of the catalyst carrier and the partition wall, and is easy to assemble. (Utility Application No. 107069, Showa 62).

In this dual exhaust system catalytic converter, the case that houses the catalyst carrier and the retainer has a structure that can be divided into two in the direction perpendicular to the flow direction of exhaust gas, and each divided case has a A first partition wall that partitions the gas passage is formed, and a holding portion that holds the retainer is formed. The retainer is formed with a second partition wall that can be brought into close contact with the first partition wall of each case.

In the dual exhaust system catalytic converter configured in this manner, the exhaust passage is divided into two by the first partition wall of each case and the second partition wall formed in the retainer. In other words, by combining the vertically divided two cases, the first partition wall and the second partition wall come into close contact with each other, and independent exhaust gas passages are formed on the left and right sides with the partition wall as the center. The end face of the catalyst carrier is held by a retainer, and this retainer is held by a holding portion of the case, so that movement of the catalyst carrier in the axial direction with respect to the case is prevented.

Therefore, by arranging each storage part on one side of the case and covering it with the other case, the catalyst carrier can be held in a predetermined position and the first
The partition wall and the second partition wall are in close contact with each other, making assembly extremely easy.

Further, although the retainer is normally fitted to the outer circumferential portion of the catalyst carrier, since the second partition is formed on the retainer, the catalyst carrier is held by the outer circumferential portion and the second partition. Stress is no longer concentrated in one part, and the durability of the catalyst carrier is increased.
Furthermore, by forming the second partition wall on the retainer, the gap between the second partition wall and the end face of the catalyst carrier can be made almost zero. Therefore, unlike the conventional structure, gas leakage does not occur from this portion, and exhaust interference within the catalytic converter is prevented.

[Problems to be solved by the invention] However, the catalytic converter of Utility Model Application No. 107069/1988 still has some problems. In other words, in order to keep the gap between the first partition wall and the second partition wall small, the dimensional accuracy of the case and retainer must be significantly increased, which makes the manufacturing technology difficult and increases the manufacturing cost. A problem arises. Further, when each partition wall is strained due to shock, vibration, or heat, the gap between the partition walls becomes large, causing interference of exhaust gas through the gap, resulting in a problem of deterioration of engine performance.

Focusing on the above problems, the present invention has been developed to protect the catalyst carrier from external forces, improve assembly ease, and minimize gas leakage from gaps between partition walls without increasing the dimensional accuracy of the case and retainer. The purpose of the present invention is to provide a dual exhaust catalytic converter that can be used.

[Means for Solving the Problems] A catalytic converter for a dual exhaust system of the present invention that meets this purpose has an end face of a catalyst carrier carrying a catalyst held in a case via a retainer, and In a dual exhaust system catalytic converter in which the exhaust gas passage in the catalytic converter is divided into two by a partition wall provided on the downstream side, the case can be divided into two in a direction perpendicular to the flow direction of the exhaust gas. In each case to be divided, a first partition wall defining an exhaust gas passage and a groove extending along the first partition wall are formed, and a holding portion for holding the retainer is formed, and a holding portion for holding the retainer is formed. , a second partition wall is formed extending along the first partition wall of each case, and an outer peripheral portion of the second partition wall is fitted into a groove of the first partition wall.

[Operation] In the dual exhaust system catalytic converter configured as described above, the exhaust passage is divided into two by the first partition wall of each case and the second partition wall formed in the retainer. In other words, by overlapping each of the vertically divided cases, the outer periphery of the second partition fits into the groove of the first partition, and independent exhaust gas passages are created on the left and right sides around this partition. It is formed.

In this case, since the outer circumferential portion of the second partition wall fits into the groove of the first partition wall, shocks, vibrations,
Even if each partition wall is distorted by heat, the gap between the first partition wall and the second partition wall does not increase. In other words, since the first partition wall and the second partition wall move relative to each other in the fitted state, the gap between the partition walls is maintained at approximately the same level as when assembled, and the exhaust gas leaking through the gap is substantially prevented. is suppressed to a negligible level.

[Embodiments] Hereinafter, preferred embodiments of the dual exhaust system catalytic converter according to the present invention will be described with reference to the drawings.

First Embodiment FIGS. 1 to 9 show a catalytic converter for a dual exhaust system according to a first embodiment of the present invention. In the figure, 1 indicates a catalytic converter, and the catalytic converter 1 is composed of a case 2, a catalyst carrier 3, a cushion member 4, and a retainer 5. The catalyst carrier 3 is, for example, a catalyst supported on ceramic or the like, and has a large number of cells 6 (pores) extending in the flow direction of the exhaust gas. The catalyst carrier 3 has an elliptical cross-sectional shape, and a cushion member 4 for elastically holding the catalyst carrier 3 is provided around the outer periphery of the catalyst carrier 3. The length of the cushion member 4 is slightly shorter than the length of the catalyst carrier 3.

Retainers 5 are attached to both end surfaces 3a of the catalyst carrier 3 to prevent movement of the catalyst carrier 3 in the axial direction. A fitting portion 5b extending in the circumferential direction and fitting into the end surface 3a of the catalyst carrier 3 is formed on the outer peripheral surface of the retainer 5, and a second fitting portion 5b extending in the flow direction of exhaust gas is formed in the center portion of the retainer 5. A partition wall 5a is formed. The outer peripheral portion 5d of the second partition 5a has a shape that follows a groove of the second partition 2d, which will be described later.

FIG. 8 shows the manufacturing process of the retainer 5. First, as shown in A of the figure, an elliptical plate-shaped retainer 5 is punched out of a flat metal plate (not shown) using a press die or the like. Thereafter, as shown in FIG. Next, as shown in C of the figure, two cuts 5c are made along the fitting portion 5b.
The portions in which the cuts 5c have been made are each bent toward the center along the center line, as shown in FIG. The bent portion becomes the second partition wall 5a, and the outer peripheral portion 5d can be fitted into a groove 2i of the case 2, which will be described later.

The case 2 includes a catalyst carrier 3, a cushion member 4,
It holds and houses the retainer 5, and is made of, for example, a thin sheet metal. The case 2 is divided into two parts in a direction perpendicular to the flow direction of exhaust gas (up and down direction), and in this embodiment, the case 2 is divided into left-right symmetrical parts.

In FIG. 1, the upper case 2 includes a case body 2a that holds the catalyst carrier 3 via a cushion member 4, an exhaust gas inlet 2b, an exhaust gas outlet 2c, and a first partition wall 2d. It is formed. The first partition 2d is located above the case main body 2a,
The exhaust gas inflow section and the exhaust gas outflow section are each divided into two by the first partition wall 2d. The first partition wall 2 d on the exhaust gas inlet side is formed so as to separate the exhaust gas that has flowed into each exhaust gas inlet 2 c to the catalyst carrier 3 . Further, the first partition wall 2d on the exhaust gas outlet side is formed so as to discharge the exhaust gas flowing out from the catalyst carrier 3 while dividing the exhaust gas.

The cross-sectional shape of the first partition wall 2d is mountain-shaped, and the ridge line 2h of the first partition wall 2d includes
A groove 2i extending along h is formed. Groove 2
The curvature of the bottom surface of i is the outer circumference 5b of the second partition 5a.
The curvature of the groove 2I is almost the same as that of the groove 2I, and the groove width of the groove 2I is constant. That is, as shown in FIGS. 2 and 4, when the cases 2 are overlapped, the outer circumference 5d of the retainer 5 fits into the groove 2i along the ridge line 2h of the first wall 2d, and the first wall 2d
No gap is formed between the outer peripheral portion 5d of the retainer 5 and the outer peripheral portion 5d of the retainer 5.

The case 2 includes a holding part 2 that holds the retainer 5.
e is formed. The holding part 2e is a stepped part located between the case body part 2a and the first partition wall 2d, and this holding part 2e prevents the retainer 5 from moving in the vertical and horizontal directions and in the flow direction of exhaust gas. ing. The diameters of the ends of the exhaust gas inflow section 2d and the exhaust gas outflow section 2c are smaller than the diameter of the case main body section 2a, and the exhaust gas inflow section 2b and the exhaust gas outflow section 2c are connected from the case main body section 2a in the case 2. The area between them is formed into a smoothly curved surface.

FIG. 9 shows the manufacturing process of the case 2.
First, a flat thin metal plate (not shown) is pressed to form the case 2 shown in A of the figure. Although not completed in this state, the case main body portion 2a and the holding portion 2e are formed. Thereafter, the case 2 shown in A in the figure is pressed in a separate process and formed into the shape shown in D in the figure. In this step, drawing is performed, and although the exhaust gas inflow portion 2b, the exhaust gas outflow portion 2c, and the first partition wall 2d are formed, although they are not yet completed. Next, case 2 shown in figure D
is pressed in a further step to form the shape shown in C in the figure. In this state, a flat joint portion 2f that is continuous with the first partition wall 2d is formed between each exhaust gas inflow portion 2b. Similarly, joint portions 2f that are connected to the first partition wall 2d are formed between the respective exhaust gas outlet portions 2c. Further, flat joint portions 2g extending in the flow direction of exhaust gas are formed at both ends of the case 2.

The upper and lower cases 2 completed through the above-mentioned steps house the catalyst carrier 3, retainer 5, and cushion member 4, and then are joined by welding. The parts to be joined are a joint part 2f connected to the first partition wall 2d and a joint part 2g formed at both ends of the case.
It is. Note that the joining of the case 2 is not limited to the above-mentioned welding, but may also be joined by folding the joint 2g,
Alternatively, they may be joined by bolts.

In this embodiment, the material of the case 2 and the retainer 5 is a thin sheet metal, but the material is not limited to a thin sheet metal, and may be made of a cast product, ceramics, or the like. Furthermore, the catalyst carrier may be constructed from a metal carrier catalyst in which a flat plate and a corrugated plate made of thin metal sheets are laminated.

Next, the operation in the first embodiment will be explained.

Exhaust gas discharged from the engine flows into each exhaust gas inlet portion 2b of the catalytic converter 1 via each exhaust pipe (not shown). The exhaust gas that has flowed into each exhaust gas inlet 2b passes through the cells 6 of the catalyst carrier 3, and is discharged from each exhaust gas outlet 2c to each exhaust pipe (not shown). In this case, both end surfaces 3a of the catalyst carrier 3 are partitioned by a second partition wall 5a formed in the retainer 5, so that the exhaust gas flowing in from one exhaust gas inlet 2b is transferred to the other exhaust gas. Interference with the exhaust gas flowing in from the gas inflow portion 2b is prevented. In other words, in the present invention, the retainer 5 that holds the catalyst carrier 3 has a second
Since the partition wall 5a is formed, the gap between the end surface 3a of the catalyst carrier 3 and the second partition wall 5a can be made almost zero, and gas leakage from this portion can be prevented. Since each retainer 5 is held by the holding part 2e of the case 2, the case 2
Movement of the retainer 5 relative to the holder 5 is also reliably prevented.
Note that in a catalytic converter in which the carrier is a metal carrier instead of a ceramic carrier, the second partition wall 5a prevents the metal carrier from shifting in the axial direction.

In addition, when the upper and lower cases 2 are stacked and joined together, the outer circumference 5d of the second partition 5a on the retainer 5 side is fitted into the groove 2i of the first partition 2d, so each partition 2d, Even if 5a is deformed due to thermal expansion or the like, gas leakage from this portion is suppressed to a minimum, and exhaust interference within the catalytic converter 1 is prevented.

Furthermore, since the section from the case body 2a of the case 2 to the exhaust gas inflow section 2b and the exhaust gas outflow section 2c is a smoothly curved surface, the flow path resistance within the catalytic converter 1 is reduced.
Exhaust gas flows smoothly. This keeps exhaust pressure low and improves engine performance.

In this way, by simply arranging the catalyst carrier etc. in one case 2 and stacking the other case 2 on top of one case, each storage member is reliably positioned at once, and gaps caused by gas leakage can be avoided. It can be made almost zero. Therefore, ease of assembly is greatly improved compared to the conventional structure, and assembly costs are reduced.

Second Embodiment FIGS. 10 to 13 show a second embodiment of the present invention. The second embodiment differs from the first embodiment only in the shape of the groove of the first partition wall and the shape of the second partition wall. By assigning the same reference numerals as in the examples, descriptions of corresponding parts are omitted,
Only the different parts will be explained.

In FIGS. 10 to 13, 2j indicates a groove formed in the first partition wall 2d of the case 2. In FIGS. In the first embodiment, the groove 2i was formed to have a constant width, but in this embodiment, the groove 2j is formed in the holding part 2.
The groove width is formed to increase as it approaches e. That is, the groove 2j has a substantially triangular planar shape.

The curvature of the outer peripheral portion 5f of the second partition wall 5e of the retainer 5 is formed to be approximately the same as the shape of the bottom surface of the groove 2j. In the first embodiment, the second partition wall 5a was constructed by bending the two plates in parallel in the region where the cut was made, but in this embodiment, the two boards forming the second partition wall 5e were Board has groove 2j
It is slightly wider than the width of the . During assembly, the distance between the two plates is compressed, and the second partition wall 5e presses against the side surface of the groove 2j by its own elastic force.

In the second embodiment configured in this way,
The second partition wall 5e is in close contact with the wall surface of the groove 2j due to its own elastic force, and almost no gap is formed between the first partition wall 2d and the second partition wall 5e. That is, during thermal deformation, etc., the outer circumferential portion 5f of the second partition 5e and the wall surface of the groove 2j move relative to each other while slidingly contacting each other, so that the two plates at the notched portion as in the first embodiment Retainer 5 bent in parallel
This makes it possible to further suppress the amount of exhaust gas leakage than when using a Other operations are similar to those in the first embodiment.

[Effects of the Invention] As explained above, when using the catalytic converter for a dual exhaust system of the present invention, the following effects can be obtained.

(a) Since the second partition wall that partitions the catalyst carrier is formed on the retainer that holds the catalyst carrier,
The gap between the end face of the catalyst carrier and the second partition wall can be made almost zero, and exhaust interference can be prevented. Further, since the outer circumferential portion of the second partition wall of the retainer is fitted into the groove extending along the first partition wall of the case, the first partition wall and the second partition wall may be separated by thermal deformation, for example. Even if the partition walls move relative to each other, the gap between the partition walls remains extremely small. Therefore, exhaust interference in this portion can be prevented and engine performance can be improved without significantly increasing the dimensional accuracy of the case and retainer.

Furthermore, by forming the second partition wall on the retainer, heat from the second partition wall can be released to the case side through the retainer, and thermal deformation and thermal deterioration of the second partition wall can be suppressed.

(b) Since the case is formed with a first partition wall that can be fitted with the holding part that holds the retainer and the second partition wall on the retainer side, each member can be stored in the case simply by overlapping the cases. can be reliably positioned at once, significantly reducing assembly costs.

(c) Since the catalyst carrier is held in the case via both the retainer and the second partition, the impact resistance of the catalyst carrier can be improved. In addition, the load acting on the end face of the catalyst carrier due to thermal expansion of the second partition wall is also distributed to the outer periphery of the retainer, so stress concentration on specific parts can be avoided and damage to the catalyst carrier can also be prevented. can.

(d) Furthermore, if part of the case is formed into a curved surface that curves smoothly along the flow of exhaust gas,
The flow of exhaust gas within the catalytic converter becomes smooth, and exhaust pressure can be reduced. Thereby, engine performance can be improved.

[Brief explanation of the drawing]

FIG. 1 is an exploded perspective view of the catalytic converter for dual exhaust system according to the first embodiment of the present invention, and FIG. 3 is a side view of FIG. 2, FIG. 4 is a plan view of the vicinity of the retainer in the catalytic converter of FIG. 1, and FIG. 5 is a perspective view of the vicinity of the groove of the case of the catalytic converter of FIG. 1; 6 is a sectional view taken along the - line in FIG. 5, FIG. 7 is a sectional view taken along the - line in FIG. 5, FIG. 8 A to E are manufacturing process diagrams of the retainer in FIG. 1, and FIG. A to C are manufacturing process diagrams of the case in FIG. 1, FIG. 10 is a plan view of the vicinity of the retainer in the dual exhaust system catalytic converter according to the second embodiment of the present invention, and FIG. 11 is the catalytic converter shown in FIG. 10. A perspective view of the vicinity of the groove in the case,
12 is a sectional view taken along the line XX in FIG. 11, and FIG. 13 is a sectional view taken along the line XX in FIG. 11. 1...Catalytic converter, 2...Case, 2a...
...Case body, 2b...Exhaust gas inlet, 2c...
...Exhaust gas outlet, 2d...First partition, 2e...
...Holding part, 2i, 2j...Groove, 3...Catalyst carrier,
5... Retainer, 5a, 5e... Second partition.

Claims (1)

[Scope of utility model registration request] A dual system in which the end face of a catalyst carrier carrying a catalyst is held in a case via a retainer, and the exhaust gas passage in the catalytic converter is divided into two by partition walls provided on the upstream and downstream sides of the catalyst carrier. In the exhaust system catalytic converter, the case has a structure that can be divided into two parts in a direction perpendicular to the flow direction of exhaust gas, and each divided case has a first partition wall that partitions an exhaust gas passage, and a first partition wall that partitions an exhaust gas passage; forming a groove extending along the partition wall of the case and forming a holding portion for holding the retainer; forming a second partition wall in the retainer extending along the first partition wall of each case; The outer peripheral part of the partition wall is
A catalytic converter for a dual exhaust system, characterized in that it fits into a groove in a partition wall.