JPH1110008A - Catalyst converter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a catalytic convertor capable of improving exhaust gas purifying performance by avoiding the opening phenomenon of a core. SOLUTION: In a structure in which the honeycomb shaped core 3 formed by laminating the catalyst carriers 5 consisting of corrugated metallic thin plates to form cells at the laminated part is formed and arranged in a shell 2, plural numbers of grooves 6 in the cylindrical direction formed toward the cylindrical peripheral direction on the inner surface of the shell 2, the catalyst carrier 5 is engaged with the grooves 6 at the outer peripheral side of the core 3 in the laminated direction to restrict the mutual detachment of the catalyst carriers 5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a catalytic converter provided in an exhaust system or the like of an automobile and purifying harmful components in the exhaust gas through a catalytic reaction by passing the exhaust gas.

[0002]

2. Description of the Related Art In a catalytic converter, for example, as shown in Japanese Patent Application Laid-Open No. 1-236948, a corrugated catalyst carrier made of a thin metal plate is overlapped to form a cell in the overlapped portion. There is known a structure in which a honeycomb core is provided in an outer cylinder.

[0003]

As described above, in the case where the honeycomb core is formed by laminating the corrugated catalyst carriers, the honeycomb carrier is formed by winding the corrugated catalyst carriers in a spiral shape. Unlike the one in which the core is formed, it is possible to avoid a so-called film-out phenomenon in which the catalyst carrier jumps backward from the center portion in a spiral shape by the inflow pressure of the exhaust gas, but receives the pressure of the exhaust gas at the inlet side of the core. As a result, a so-called opening phenomenon in which the superposed catalyst carriers are separated from each other occurs, and particularly when the catalyst carriers are provided close to the exhaust manifold, the phenomenon becomes conspicuous, and the exhaust gas purification performance decreases. there is a possibility.

Accordingly, the present invention can prevent the opening and closing phenomenon caused by the separation of the superposed corrugated catalyst carriers due to the pressure of the exhaust gas on the core inlet side, thereby improving the purification performance of the exhaust gas. An object of the present invention is to provide a catalytic converter that can be further improved.

[0005]

According to the first aspect of the present invention, a catalyst-shaped core made of corrugated metal sheets is overlapped to form a honeycomb-shaped core having cells formed in the overlapped portion. In the structure disposed in the cylinder, on the inner surface of the outer cylinder, a plurality of grooves in the cylinder length direction are formed in the cylinder circumferential direction,
The catalyst carrier is engaged with the groove in the overlapping direction on the outer peripheral side of the core, thereby restraining the catalyst carriers from being separated from each other.

According to a second aspect of the present invention, there is provided the catalytic converter according to the first aspect, wherein the groove is provided at least on the inlet side of the core of the outer cylinder.

A third aspect of the present invention is the catalytic converter according to the first or second aspect, wherein the groove is formed by providing serrations on an inner surface of the outer cylinder.

According to a fourth aspect of the present invention, there is provided the catalytic converter according to the first or second aspect, wherein the groove is formed by a corrugated plate fixed in the outer cylinder.

According to a fifth aspect of the present invention, there is provided the catalytic converter according to any one of the first to fourth aspects, wherein the groove carries a catalyst on a surface thereof.

According to a sixth aspect of the present invention, there is provided the catalytic converter according to any one of the first to fifth aspects, wherein the core is formed by continuously folding one catalyst carrier in an S-shape in a waveform direction to form a honeycomb. It is characterized in that it is configured by overlapping in a shape.

According to a seventh aspect of the present invention, there is provided the catalytic converter according to any one of the first to sixth aspects, wherein the catalyst carrier has a sloping wall that forms a ridge and a valley of the waveform on the ridge of the waveform. While a plurality of cut and raised valleys cut and raised in the reverse direction from the middle position are provided in the fold direction of the waveform, the valleys of the waveform are cut and raised in the reverse direction from the middle position of the inclined wall. It is characterized in that a plurality of cut-and-raised ridges are provided in the direction of the fold of the waveform.

According to an eighth aspect of the present invention, there is provided the catalytic converter according to the seventh aspect, wherein the cut and raised valley and the cut and raised ridge form a sloped wall that forms a corrugated peak and a valley of the catalyst carrier. Characterized by being cut and raised from the center position of.

According to a ninth aspect of the present invention, there is provided the catalytic converter according to the seventh aspect, wherein the center of the inclined wall forming the peak and the valley of the waveform of the catalyst carrier is formed along the direction of the fold of the waveform. A shelf is formed, and a cut-and-raised valley formed in each adjacent ridge and a cut-and-raised ridge formed in a valley are cut and raised with the shelf as a boundary to form an adjacent cut. An interval of a shelf width is set in a waveform direction between the cut and raised toes of the raised valley and the cut and raised ridge.

According to a tenth aspect of the present invention, there is provided the catalytic converter according to any one of the seventh to ninth aspects, wherein the cut-and-raised valley formed at the peak of the waveform of the catalyst carrier and the cut formed at the valley. The raised ridges are formed offset in the direction of the fold of the waveform, and a necessary space is formed between the adjacent raised and cut valleys and the cut and raised toes of the raised and raised ridges at the crease of the waveform. It is characterized by having been set.

[0015]

According to the first aspect of the present invention, the separation of the catalyst carriers is restricted by engaging the overlapped catalyst carriers with the grooves. The opening phenomenon in which the catalyst carriers are separated from each other from the center of the core or the like can be prevented, and the honeycomb shape in which a large number of cells are gathered can be prevented from being deformed, so that the exhaust gas purification performance can be further improved.

According to the invention of claim 2, in addition to the effect of the invention of claim 1, it is possible to reliably prevent the opening phenomenon in which the catalyst carriers are separated from each other on the inlet side of the core.

According to the third aspect of the present invention, in addition to the effects of the first or second aspect of the invention, the opening phenomenon can be reliably prevented by firmly engaging the catalyst carrier with the serration. Also, the grooves can be formed by simply processing the inner surface of the outer cylinder, and the formation of the grooves is extremely easy.

According to the invention of claim 4, in addition to the effect of the invention of claim 1 or 2, the catalyst carrier is engaged by the corrugated plate, and the opening phenomenon can be reliably prevented. Also, since the groove can be formed only by fixing the corrugated sheet in the outer cylinder,
The degree of freedom such as the set position increases.

According to the fifth aspect of the present invention, in addition to the effects of any one of the first to fourth aspects, the surface of the groove can also be used as a catalytically active surface. This significantly increases the exhaust gas purification performance.

According to the sixth aspect, in addition to the effects of the first to eighth aspects, a core is formed by folding one catalyst carrier continuously in an S-shape in a waveform direction and overlapping in a honeycomb shape. Therefore, the core can be easily configured,
The film-out phenomenon in which the catalyst carrier jumps backward due to the inflow pressure of the exhaust gas can be prevented.

According to the seventh aspect, in addition to the effects of the first to sixth aspects, in addition to the effects of the first to sixth aspects, the catalyst carrier has a plurality of cut-and-raised valleys formed by cutting and raising in the direction opposite to the peak of the waveform in the direction of the fold of the waveform. In addition, the valleys of the corrugations are provided with a plurality of ridges which are formed in the opposite direction in the valleys of the corrugations. In addition to the fact that exhaust gas can be circulated, the exhaust gas can be brought into sufficient contact with the catalyst on the surface of the catalyst carrier and the catalytic reaction can be actively carried out, Since the cells can be secured by preventing the adjacent catalyst carriers from contacting each other due to the presence of the portion, the purification performance of the exhaust gas can be improved.

Further, since the exhaust gas can be circulated between the cells formed between the superposed catalyst carriers, the pressure distribution of the exhaust gas can be made substantially uniform as a whole, and Durability can also be improved.

Further, by forming the cut and raised valleys and the cut and raised ridges, the rigidity of the catalyst carrier can be increased.

According to the eighth aspect, in addition to the effect of the seventh aspect, in addition to the effect of the seventh aspect, the cut and raised valley and the cut and raised ridge are formed at the center of the inclined wall which forms the corrugated peak and the valley of the catalyst carrier. Since the cut and raised portion is formed from the position, the cut and raised opening area of the cut and raised valley portion and the cut and raised portion can be increased, and the flow of exhaust gas between cells can be improved. it can.

Further, it is possible to make the crests and cuts and ridges of the catalyst carrier and the valleys and cut and raise valleys of the waveform the same amount of protrusion, so that the close contact between the catalyst carriers is reliably prevented. Can be.

According to the ninth aspect, in addition to the effect of the seventh aspect, the cut and raised valley and the cut and raised ridge are formed at the center of the inclined wall forming the corrugated peak and the valley of the catalyst carrier. Since the cut-and-raised portion is formed with the ledge formed at the position as a boundary, the cut-and-raised portion and the cut-and-raised portion can be increased in the opening area, and the exhaust gas between the cells can be increased. Distribution can be improved.

Further, it is possible to make the corrugated peaks and ridges of the catalyst carrier and the corrugated valleys and cut and raised valleys the same amount of protrusion, thereby reliably preventing the catalyst carriers from sticking to each other. Can be.

Further, a gap of the width of the ledge is secured between the cut and raised toes of the adjacent cut and raised valleys and the cut and raised ridges. It is possible to avoid tearing between the raised ends.

According to the tenth aspect, in addition to the effects of the seventh to ninth aspects, a required space is provided between the cut and raised toes of the cut and raised valley and the cut and raised ridge in the crease direction of the waveform. Since the interval is set, it is possible to reliably prevent the cut-and-raised toe from being torn due to the difference in the thermal expansion coefficient.

[0030]

Embodiments of the present invention will be described below in detail with reference to the drawings.

(First Embodiment) In FIGS. 1 and 2, reference numeral 1 denotes a catalytic converter, which comprises a metal outer cylinder 2 formed in an elliptical cross section, and a honeycomb core 3 disposed in the outer cylinder 2. It has.

The diffusers 4 at both ends of the outer cylinder 2 are formed separately, and these diffusers 4 and 4 are fitted and fixed in both ends of the outer cylinder 2.

Reference numeral 5 denotes a catalyst carrier constituting the core 3, which is formed into a corrugated shape by a thin metal plate such as stainless steel having a catalyst carried on the surface thereof. Although the cells are continuously folded in a letter shape and overlapped in a honeycomb shape to form cells in each overlapped portion, a plurality of catalyst carriers 5 may be stacked to form a honeycomb-shaped core 3. .

On the other hand, in the present embodiment, a plurality of grooves 6 are formed in the inner surface of the outer cylinder 2 in the cylinder length direction (left and right directions in FIG. 2) in the cylinder circumferential direction. The folded portion 5g of the carrier 5 is engaged in the overlapping direction (the left-right direction in FIG. 1), and restricts the separation of the catalyst carriers 5 from each other.

The groove 6 is provided at least on the inlet side of the core 3 of the outer cylinder 2. In the first embodiment, as shown in FIG. 2, both the inlet side and the outlet side of the core 3 are provided. A groove 6 is provided.

The groove 6 is formed by providing a serration 7 on the inner surface of the outer cylinder 2 as shown in FIG. And
A catalyst is carried on the surface of each groove 6.

In view of the fact that the groove 6 is particularly likely to open at the center of the core 3 (the center on the left and right in FIG. 1), the catalyst carrier 5 is engaged with the groove 6 at least on the center. It can also be configured as follows.

As the catalyst carrier 5, those shown in FIGS. 4, 5 or 6 to 8 are used.

Each of the catalyst carriers 5 shown in these figures is formed by cutting and raising in the opposite direction from the midway position of the inclined wall 5c forming the crest 5a and the valley 5b of the corrugation on the crest 5a of the corrugation. While a plurality of cut-and-raised valleys 5d are provided in the direction of the fold of the waveform, the valley 5b of the waveform has a cut-and-raised ridge 5e formed by being raised and raised in the opposite direction from an intermediate position of the inclined wall 5c. A plurality is provided in the fold direction of the waveform.

Here, in the catalyst carrier 5 shown in FIGS. 4 to 6, a ledge 5f is formed at the center position of each sloping wall 5c of the corrugation along the fold direction of the corrugation, and each adjacent peak is formed. Part 5a
The cut-and-raised valley portion 5d formed in the valley portion 5b and the cut-and-raised ridge portion 5e formed in the valley portion 5b are cut and raised with the shelf portion 5f as a boundary, and cut with the adjacent cut-and-raised valley portion 5d. between the cut-and-raised toe of raised ridges 5e is set apart S ₁ of the width of the shelf portion 5f in the waveform direction.

In the example shown in FIGS. 4 and 5, the peak 5a and the cut-and-raised valley 5d adjacent to the peak 5a are formed to have the same length, and the regularity is set such that the pinch is shifted by one pinch in the fold direction of the waveform. In the example shown in FIG. 6, the peaks 5a and the valleys 5b, the cut-and-raised valleys 5d, and the cut-and-raised ridges 5e are formed to have the same length, and the adjacent peaks are formed. 5a
e, and the adjacent valleys 5b and the raised valleys 5d are regularly formed in a state shifted by one pitch in the fold direction of the waveform. The ridges 5e are formed in such a manner as to be offset in the fold direction of the waveform without such a rule, and between the adjacent cut-and-raised valleys 5d and the cut-and-raised toes of the cut-and-raised ridges 5e. Alternatively, a required interval may be set in the fold direction of the waveform.

The catalyst carrier 5 shown in FIGS. 7 and 8 is formed such that the adjacent cut and raised valleys 5d and the cut and raised ridges 5e are offset from each other in the direction of the fold of the waveform. between each cut-and-raised toe electromotive City valley 5d and-lifted crests 5e, it is set the required interval S ₂ in the fold direction of the waveform.

In the example shown in FIG. 7, the cut and raised valley portion 5d and the cut and raised ridge portion 5e are formed by cutting and raising the center position of the inclined wall 5c in the opposite direction. In the example shown in FIG. 5, the cut and raised valley 5d is formed shallower than the corrugated valley 5b, and the cut and raised valley 5e is formed lower than the corrugated ridge 5a, so that the adjacent cut and raised valley 5d is formed. other spacing S ₂ of the fold direction of the aforementioned waveform between the cut-and-lifted toe of the cut-and-raised ridges 5e,
Required interval S ₃ in the waveform direction are to be set.

Next, the operation will be described. Normally, the exhaust gas flowing into the catalytic converter 1 from an exhaust pipe (not shown) having a diameter smaller than that of the core 3 flows into a substantially entire cell on the inlet side of the core 3 by the diffusion action of the diffuser 4 on the inlet side. Nevertheless, the exhaust gas flowing from the exhaust pipe tends to concentrate at the center of the core 3, and the catalyst carriers 5 superposed at the center of the core 3 tend to be separated from each other.
Further, due to this separation, the end face of the catalyst carrier 5 tends to be deformed, or the catalyst carrier 5 tends to be inclined with respect to the outer cylinder 2.

However, as described above, since the folded portion 5g of the catalyst carrier 5 engages with the groove 6 on the outer peripheral side of the core 3, mutual separation of the catalyst carriers 5 is restricted, and the catalyst carrier 5 is closed at the entrance side of the core 3. It is possible to prevent the opening and closing phenomenon in which the catalyst carriers 5 are separated from each other from the central portion of the core 3 by the inflow pressure of the exhaust gas, and to eliminate the deformation of the honeycomb shape in which a large number of cells are assembled, thereby purifying the exhaust gas. Performance can be improved.

In this embodiment, since the groove 6 is also provided on the outlet side of the core 3, the opening phenomenon can be prevented and the shape of the entire core 3 can be maintained. Also, the exhaust gas purification performance can be improved.

Further, normally, when deformation such as opening of the core 3 occurs, a gap is formed between the outer peripheral side of the core 3 and the inner surface of the outer cylinder 2, and gas is short-circuited to the rear side from this gap. And the purification performance tends to decrease because the catalyst cannot contact the catalyst. However, as mentioned above,
Since the opening of the core 3 is prevented and the catalyst is also carried on the inner surface of the groove 6, the reaction can be sufficiently performed even in this portion, and the catalyst active area is significantly improved. Purification performance can be improved.

Since the serrations 7 project from the inner surface of the outer cylinder 2, when the diffusers 4 are fitted to the front and rear of the outer cylinder 2, the diffusers 4 can be abutted against the serrations 7 and positioned easily. .

Next, in the present embodiment, as the above-mentioned catalyst carrier 5, a cut-and-raised valley 5d formed by cutting and raising in the opposite direction to the corrugated peak 5a as shown in FIGS. And a plurality of cut-and-raised ridges 5e formed in the corrugated valley 5b in the opposite direction in the fold direction of the corrugation. 5
As shown by arrows in FIG. 4, the exhaust gas can flow between the cells formed mutually, so that the exhaust gas is sufficiently brought into contact with the catalyst on the surface of the catalyst carrier 5 to activate the catalytic reaction. In addition to the above, the presence of the cut and raised valley portion 5d and the cut and raised ridge portion 5e can prevent the adjacent catalyst carriers 5 from contacting each other and secure cells, so that the exhaust gas Purification performance can be further improved.

Further, the catalyst carriers 5 thus superposed are overlapped.
The exhaust gas can be circulated between the cells formed between the cores 3. Therefore, the pressure distribution of the exhaust gas can be made substantially uniform over the entire core 3, and the durability of the core 3 is improved. be able to.

Further, by forming the cut and raised valleys 5d and the cut and raised ridges 5e, the rigidity of the catalyst carrier 5 itself can be increased, and the sense of quality and reliability can be improved.

Here, if the catalyst carrier 5 shown in FIGS. 4 to 6 is used, the cut-and-raised valley 5d and the cut-and-raised peak 5e are connected to the corrugated peak 5a and the valley 5b of the catalyst carrier 5. Since it is formed with the ledge 5f formed at the center position of the sloped wall 5c to be formed as a boundary, the cut and raised valley 5d and the cut and raised ridge 5e can have a larger opening area. As a result, the flow of exhaust gas between the cells can be improved.

Further, the corrugated peaks 5a and the raised ridges 5e and the corrugated valleys 5b and the raised valleys 5d of the catalyst carrier 5 can be made to have the same protrusion amount, so that the catalyst carriers 5 are in close contact with each other. Can be reliably prevented.

Further, between the cut-and-raised ends of the adjacent cut-and-valley portions 5d and the cut-and-raised ridge portions 5e, the shelves 5f are arranged in the waveform direction.
The interval S ₁ of the width of is ensured, may be between the cut-and-raised toe by the difference in thermal expansion rate to avoid to manufacturing cross.

When the catalyst carrier 5 shown in FIG. 7 is used, it is possible to obtain the same exhaust purification performance as when using the catalyst carrier shown in FIGS. and between each cut-and-raised toe of the mountain portion 5e, so the fold direction of the waveform is set a required distance S _2, between the cut-and-raised toe by the difference in thermal expansion rate in this case is Seidan Can be avoided.

Further, if the catalyst carrier 5 shown in FIG. 8 is used,
In addition to obtaining substantially the same exhaust purification performance as the case of using the one shown in FIG. 7, a wavy crease is provided between the cut and raised toes of the cut and raised valley 5d and the cut and raised ridge 5e. Required spacing S in the direction
_2, because is set the required interval S ₃ to the waveform direction can this be reliably avoid manufacturing cross between raised toe and chopped by the difference in thermal expansion coefficient.

(Second Embodiment) FIG. 9 is an enlarged sectional view of a main part corresponding to FIG. 3 according to a second embodiment of the present invention.
The components corresponding to those of the first embodiment are denoted by the same reference numerals, and the description thereof will not be repeated.

In this embodiment, the groove 6 is formed by the corrugated plate 8 fixed in the outer cylinder 2. The corrugated sheet 8 is formed of stainless steel or the like.
The respective tops 8a are fixed by brazing, diffusion bonding, or the like. The end of the corrugated sheet 8 is closed by the diffuser 4, and the exhaust gas does not pass between the corrugated sheet 8 and the outer cylinder 2 in a short-circuit manner. Other configurations are substantially the same as those of the first embodiment.

Therefore, in the present embodiment, substantially the same functions and effects as those of the first embodiment can be obtained. Further, in the present embodiment, since the corrugated sheet 8 which is separate from the outer cylinder 2 is fixed by brazing or the like, it is easy to adjust the setting position of the corrugated sheet 8 with respect to the outer cylinder 2 and the flow of the exhaust gas. The number to be installed in the direction can also be appropriately selected,
The degree of freedom increases.

Although the grooves 6 are provided on the inlet side and the outlet side of the cell 3 in each of the above embodiments, they may be provided only on the inlet side. Further, it can be provided from the entrance to the entire exit, and if it can prevent the opening, it can also be disposed behind the entrance.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view showing a first embodiment of the present invention, taken along line AA of FIG. 2;

FIG. 2 is a schematic sectional view showing the entire structure of the first embodiment.

FIG. 3 is an enlarged sectional view of a main part according to the first embodiment.

FIG. 4 is a perspective view of a catalyst carrier used in each embodiment.

FIG. 5 is an explanatory view of the catalyst carrier shown in FIG.

FIG. 6 is an explanatory view showing a different example of a catalyst carrier.

FIG. 7 is an explanatory view showing another example of a catalyst carrier.

FIG. 8 is an explanatory view showing a different example of a catalyst carrier.

FIG. 9 is an enlarged sectional view of a main part according to a second embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Catalytic converter 2 Outer cylinder 3 Core 5 Catalyst carrier 5a Wave-shaped peak 5b Wave-shaped valley 5c Sloping wall 5d Cut and raised valley 5e Cut and raised ridge 5f Shelf 6 Groove 7 Serration 8 Corrugated plate

Claims (10)

[Claims] 1. A structure in which a catalyst carrier made of a corrugated metal sheet is overlapped to form a honeycomb core having cells formed in the overlapped portion, and the core is disposed in an outer cylinder. On the inner surface of the cylinder, a plurality of grooves in the cylinder length direction are formed in the cylinder circumferential direction, and the catalyst carriers are engaged with the grooves in the overlapping direction on the outer peripheral side of the core to restrict the separation of the catalyst carriers. A catalytic converter characterized by the following. 2. The catalytic converter according to claim 1, wherein the groove is provided at least on an inlet side of a core of the outer cylinder. 3. The catalytic converter according to claim 1, wherein the groove is formed by providing serrations on an inner surface of the outer cylinder. 4. The catalytic converter according to claim 1, wherein the groove is formed by a corrugated plate fixed in the outer cylinder. 5. The catalytic converter according to claim 1, wherein the groove has a surface on which a catalyst is supported. 6. The catalytic converter according to claim 1, wherein the core is formed by continuously folding one catalyst carrier in an S-shape in a waveform direction and overlapping the honeycomb in a honeycomb shape. A catalytic converter, comprising: 7. The catalytic converter according to claim 1, wherein the catalyst carrier is formed on the corrugated peak from an intermediate position of a slope wall forming the corrugated peak and valley. While a plurality of cut and raised valleys are formed in the fold direction of the waveform, the cut and raised valleys are formed by cutting and raising in the opposite direction from the middle position of the inclined wall. A catalytic converter comprising a plurality of peaks in the direction of a fold of a waveform. 8. The catalytic converter according to claim 7, wherein the cut-and-raised valley and the cut-and-raised ridge are cut from a center position of a slope wall forming a wave-shaped peak and a valley of the catalyst carrier. A catalytic converter characterized by being raised and formed. 9. The catalytic converter according to claim 7, wherein a shelf is formed along a fold direction of the waveform at a center position of the inclined wall forming a peak and a valley of the waveform of the catalyst carrier. The cut-and-raised valley formed in each adjacent peak and the cut-and-raised ridge formed in the valley are cut and raised with this shelf as a boundary,
A catalytic converter characterized in that an interval of a shelf width is set in a waveform direction between adjacent cut and raised toes of a cut and raised valley and a cut and raised ridge. 10. The catalytic converter according to claim 7, wherein a cut-and-raised valley formed at a peak of a waveform of the catalyst carrier, and a cut-and-raised peak formed at the valley. Are formed offset in the direction of the fold of the waveform, and a necessary interval is set between the cut and raised toes of the adjacent cut and raised valleys and the cut and raised ridges. And a catalytic converter.