JPS5911724B2 - Exhaust gas catalytic converter for internal combustion engines - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates to the treatment of exhaust gas from internal combustion engines, and more particularly to a catalytic converter for treating exhaust gas to convert its undesirable components into harmless forms.

The catalytic converter is connected within the engine's exhaust system,
Exhaust gas from the engine is passed through a bed of catalytic material held in a converter that oxidizes carbon monoxide and unburned hydrocarbons in the exhaust gas to form carbon dioxide and water; or) reduce nitrogen oxides.

holding a catalyst inside a porous catalyst holder, accommodating this in a '□housing, and introducing the exhaust gas to be treated into a space formed by the upper part of the housing and the upper part of the catalyst holder; Various catalytic converters have been proposed in which exhaust gas passes through a porous catalyst holder by flowing the exhaust gas into a space formed by the lower part of the housing and the lower part of the catalyst holder, but none of them have been proposed. There are durability issues regarding gas leaks.

Examples of such known catalytic converters include catalyst retainers,
There are configurations of a perforated upper plate, a perforated lower plate, a vertical plate sealingly closing the upper and lower plates at their upstream ends, and a vertical plate similarly closing the downstream side.

In this case, the upper and lower plates extend transversely to the gas flow direction and are sandwiched between the flanges of the outer housing plate in order to allow the exhaust gas to flow past the catalyst holder. , the lower end of the vertical plate is in sealing contact with the housing at the upstream end, and similarly the upper end of the vertical plate is in sealing contact at the downstream end.

Due to the structure, it is necessary to achieve a sealed state through such a sealed contact (for example, U.S. Pat. No. 3,600,142).
.

Other known catalytic converters include, for example, U.S. Pat.
No. 6073, the invention shows a catalyst bed that is inclined with respect to the construction of the housing, the bed having a substantially uniform cross-section for gas flow at all points over the entire axial length of the transducer. I'm looking forward to it.

However, this converter does not have a catalyst retainer member whose ends are sandwiched between the flanges of the housing member and which are secured and sealed at the ends.

This patent also includes a catalyst retainer member extending imperforately into the inlet passageway at the bottom of the incoming exhaust gas and extending imperforately into the outlet passageway at the top of the exiting exhaust gas. do not have.

Furthermore, this patent does not have top and bottom retainer members forming a sloped catalyst bed with dish-shaped portions that respectively increase and decrease in depth from the exhaust gas inlet to the exhaust gas outlet.

The converter of this U.S. patent therefore addresses the issues of transducer sticking, sealing, flow uniformity, and durability in devices that withstand the thermal stress caused by the inevitable temperature gradients and rapid temperature changes in catalytic converters. lack of consideration.

However, since the catalytic converter is subject to such large temperature changes that the plates "warp" and "bend", it is practically impossible to maintain a sealed state with these known structures.

In other words, during use, such a sealed part can easily open due to the "warping" or "bending" of the plate, which becomes a leak path that circulates around the catalyst and releases harmful gases into the atmosphere. This becomes an obstacle to effective exhaust gas treatment.

Considering the basic function of a catalytic converter, the occurrence of a leak circulating through the catalyst means that the converter is unusable or damaged.

Therefore, known catalytic converters suffer from a lack of durability.

An object of the present invention is to obtain a catalytic converter for an internal combustion engine that has a strong structure, has no possibility of leakage circulating around the catalyst, and is highly durable.

The converter according to the invention provides uniform flow and low pressure drop to the exhaust gas through the catalyst bed.

Its low profile conforms to the limited space requirements for placement under the vehicle, and the upward and downward extensions of the converter retainer facilitate the inflow of exhaust gases. and leaks out.

Thus, the features of the invention ensure that the housing and retainer are secured and sealed together, providing low resistance to gas flow.

A sloped catalyst bed providing a uniform pressure gradient is obtained with a simple cage construction in which the depth of the dish in the top and bottom cage members increases and decreases, respectively, to provide a slight slope.

The present invention provides an exhaust gas catalytic converter for an internal combustion engine in which exhaust gases flow past a catalyst contained within a catalyst retainer within a housing, the housing having top and bottom housing members; The housing members each have a dish-shaped portion that encloses the catalyst retainer, and the dish-shaped portions each have a sump half forming a cylindrical exhaust gas inlet channel and an outlet channel. a cylindrical portion, the inlet flow path and the outlet flow path being each disposed axially spaced from a catalyst receiving portion of the catalyst holder; the catalyst retainer has a flange portion that is sandwiched between flange portions extending around the periphery of the housing member;
The catalyst retainer is formed by top and bottom retainer members, the top and bottom retainer members each having a dish-shaped portion forming the catalyst receptacle; is directly connected to the inlet side cylindrical member of the exhaust system, and is provided with an upward recessed portion integrally formed of the same material as the dish-shaped portion at one end thereof, and the upward recessed portion is connected to the catalyst housing portion. a portion of the upwardly recessed portion overlaps and extends axially into the inlet half cylinder of the top housing member; a cylindrical exhaust gas inlet barrel, in which both the top housing member and the catalyst retainer are directly connected to the inlet cylindrical member of the exhaust system; Among the container members, at least the bottom retainer member is provided with a downward recessed portion at the other end, which is directly connected to the outlet side cylindrical member of the exhaust system and is integrally formed of the same material as the dish-shaped portion. , the downward recess extends from the catalyst accommodating portion to the outlet flow path in a non-porous state, and a portion of the downward recess overlaps with the outlet semi-cylindrical portion of the top portion of the housing member and extends in the axial direction. extending to form a cylindrical exhaust gas outlet cylinder with the outlet semi-cylindrical portion of the bottom housing member, in which the bottom housing member and the catalyst retainer both extend into said outlet side cylinder of the exhaust system. The inlet semi-cylindrical part, the dish-shaped part and the outlet semi-cylindrical part constituting the top and bottom housing members are each integrally formed of the same material; The flange portion of the housing is integrally provided on the entire peripheral edge of the member except for the exhaust gas artificial edge and the outlet edge, and the exhaust gas artificial edge and the peripheral edge of the top and bottom retainer members are integrally provided. A flange portion of the catalyst holder is integrally provided over the entire periphery except for the outlet edge, and the flange portion provided on the periphery of both cage members is the flange portion provided on the periphery of both housing members. furthermore, the top and bottom retainer members (e.g., 26, 28) have a substantially uniform depth and extend upwardly from the exhaust gas inlet (e.g., 56) toward the exhaust gas outlet (e.g., 58). The dish-shaped portions of the top and bottom retainer members form a catalyst receiving space that is inclined in the direction of the exhaust gas inlet (eg 56) to the exhaust gas outlet (
For example, 58) is characterized by an increasing and decreasing depth, respectively.

Additionally, it is desirable for gas flow through the catalyst bed to be substantially uniformly distributed throughout the bed for maximum catalyst life and optimum conversion; generally uniform distribution is achieved by the dished portions of the top and bottom retainer members. achieved.

This is because the dish-shaped portion defines a catalyst receptacle of substantially uniform depth which is oriented upwardly between the exhaust gas inlet and outlet.

This slightly sloped catalyst housing therefore reduces the overall height of the converter compared to a case where the inlet and outlet gas flow paths are of constant height.

In particular, the converter of the present invention has a low profile, high resistance to gas leaks that quickly pass through the catalyst, and does not restrict gas flow.

The low profile profile allows the top and bottom retainer members to be sandwiched between the top and bottom housing members, reducing the depth of the top and bottom retainer members... This is accomplished by defining a substantially uniform depth of the catalyst receptacle that is slightly inclined relative to the housing by varying inversely between

Durability is minimal (at least the top retainer member is non-porous and extends axially upward relative to the inlet flow path below the incoming exhaust gas, and at least the bottom retainer member is non-porous). This is achieved by extending axially downwards relative to the outlet passage above the exiting exhaust gas.

Durability is also achieved by sandwiching the laterally extending flange portions of the retainer member in an overlapping manner between integral flange portions of the housing member.

That is, the laterally extending flange portions of the retainer and the laterally extending portions of the top and bottom retainer members cooperate to prevent gas leaks that would quickly displace the catalyst and increase durability.

Minimizing gas flow restriction is also achieved by an elongated catalyst retainer structure that corresponds to the flow of gas into and out of the converter.

The structure of this catalytic converter provides a streamlined interior to allow exhaust gas to easily flow into and out of the converter.

The top and bottom retainer members are disposed at varying intervals inside the top and bottom housing members;
It constitutes a slightly inclined catalyst accommodating portion whose depth is approximately constant.

That is, the spacing between the top retainer member and the top housing member decreases progressively from the gas inlet to the outlet, thereby creating a progressively decreasing cross section for the incoming gas flow, resulting in an approximately constant pressure. Add gradient.

Similarly, the spacing between the bottom retainer member and the bottom housing member increases progressively from the gas inlet to the outlet, creating an increasing cross-section for the discharging gas, again providing a nearly constant pressure. Add gradient.

This is accomplished in the retainer of the invention by increasing and decreasing the depth of the dish-shaped portions of the top and bottom retainer members, respectively, from the gas inlet to the outlet.

The present invention and its implementation method will be explained in detail below with reference to the drawings.

In the figures, similar parts, apart from minor differences, are indicated by the same reference numerals.

4 to 12 show an embodiment of a catalytic converter connected to an exhaust system inlet cylindrical member 60 and an exhaust system outlet cylindrical member 62. A preferred embodiment of this catalytic converter has a nozzle 10. The housing 10 is preferably formed of high chrome stainless steel or coated or plated steel to resist the corrosive effects of hot salts and gases.

The housing 10 consists of a top housing member 12 and a bottom housing member 14, each having a respective dish-shaped portion, the dish-shaped portion having a generally vertical side wall portion 16.
It has 18.

The top housing member 12 has an inlet semi-cylindrical portion 64 (
6 and 12) on the downstream side, and an outlet semi-cylindrical portion 64 (on the right side in the same figure), which connects the dish-shaped portion of the top housing member 12, the inlet semi-cylindrical portion 64, and the outlet semi-cylindrical portion 64.
are integrally formed from the same material.

The bottom housing member 14 also has an inlet semi-cylindrical portion 6 on the upstream side.
6 (on the left in FIGS. 6 and 12), and an outlet semi-cylindrical portion 66 (on the right in FIGS. 6 and 12) on the downstream side, and the bottom housing member 14
The dish-shaped portion, the inlet semi-cylindrical portion 66, and the outlet semi-cylindrical portion 66 are integrally formed of the same material.

Furthermore, the top and bottom housing members 12 and 14 have flange portions 20, 12 and 14 extending over the entire periphery of the top and bottom housing members 12 and 14, excluding the exhaust gas port edge and the outlet edge, for clamping the flange of the retainer member, which will be described later. 22 are integrally provided.

Mounted within the housing 10 is a sloped catalyst retainer 24 consisting of a top retainer member 26 and a bottom retainer member 28 (the tilt is discussed below). 46 , the dish of the top retainer member 26 is spaced apart from the dish of the top nozzle member 12 .
0 and the top pore is large, approximately 1/16 inch (approximately 1/16 inch)
．． 6 mm) with a plurality of regularly spaced small holes 32'.

Similarly, the dished portion of the bottom retainer member 28 has a bottom porous portion 34 spaced apart from the dished portion of the bottom retainer member 140, with a small hole 36' formed therethrough.

The openings 32', 36' may be of other configurations.

For example, they may be in the form of holes extending through the top or bottom retainer members, or projecting outwardly from the top or bottom retainer members and recessed in the direction of the incident gas flow (Figs.
The embodiment illustrated in FIG. 3 may be formed as a lance-shaped aperture forming a dovetail, as indicated at 32.36, or alternatively the preferred embodiment illustrated in FIGS. 4-11. and (2) an armor window 32' made by cutting a metal section out of the plane of the plate and pressing the section to form several rows of regularly spaced arcuate armor windows;
36' (approximately 0.065 inches high and approximately 0.15 inches wide).
m) and approximately 0.5' (7 inches (12,7 mm) in length,
The spacing between successive aligned armor windows should be approximately 0.25 inches (
6,35 mm) and the spacing between each row is 0.15 inch (3
, 81 mm).

Catalyst housing 46 is filled with a desired catalyst material 48, which is packaged therein to form a catalyst bed, as will be described below.

The catalyst may be used in any form, but is preferably in the form of large approximately 14 inch (3.17 mm) pellets, extrudates or spheres, with or without a support or carrier. Good too.

The catalyst is also preferably distributed on or impregnated with a support or carrier, which may or may not contribute to the catalytic activity of the material.

The catalyst may be any suitable oxidation or reduction catalyst, or a catalyst that can perform both oxidation and reduction and is effective for a long period of time up to an operating temperature of 870°C.

It is desirable that the catalyst bed be relatively shallow to minimize back pressure within the exhaust system.

A bed approximately 2 inches (50,8 mm) deep has been found to be suitable.

As shown in FIG. 8, the catalytic material 48 occupies the space between each arcuate shroud window 32', but is of sufficient size so that it is confined by and does not pass through the opening formed by the shroud window.

The upstream ends of the top retainer member 26 and the bottom retainer member 28 (on the left in FIGS. 6 and 12) are provided with upward recesses that are directly connected to the inlet cylindrical member 60 of the exhaust system, respectively. The upward concave portion is integrally formed of the same material as each dish-shaped portion (Fig. 12), and as is clear from Fig. 12, this upward concave portion has no opening for gas passage and is a non-porous hole. It is something.

The upwardly recessed portion of the top retainer member 26 has a semi-cylindrical portion 68 and a joining portion between the semi-cylindrical portion 68 and the dish-shaped portion.

Similarly, the upward concave portion of the bottom retainer member 28 also has a semi-cylindrical portion 70.
and a portion connecting the semi-cylindrical portion 70 and the dish-shaped portion.

The downstream ends of the top retainer member 26 and the bottom retainer member 28 (right side in FIGS. 6 and 12) are provided with downward recesses that are directly connected to the outlet side cylindrical member 62 of the exhaust system, respectively. The downward concave portion is integrally formed of the same material as each dish-shaped portion (Fig. 12), and as is clear from Fig. 12, this downward concave portion has no opening for gas passage and is a non-porous hole. It is something.

The downwardly recessed portion of the top retainer member 26 has a semi-cylindrical portion 72 and a connecting portion between the semi-cylindrical portion 72 and the dish-shaped portion.

Similarly, the downward concave portion of the bottom retainer member 2B also has a semi-cylindrical portion 74.
and a portion connecting the semi-cylindrical portion 74 and the dish-shaped portion.

As previously mentioned, the top housing member 12 includes semi-cylindrical sections 64 on the upstream and downstream sides, as best seen in FIG.

The bottom housing member 14 also includes semi-cylindrical portions 66 on the upstream and downstream sides.

As shown in FIG. 6 (left side), on the upstream side, portions of the upward recesses of both retainer members overlap and extend axially with the inlet semi-cylindrical portion 66 of the bottom housing member 14; Together with the inlet semi-cylindrical portion 64 of the housing member 12, a cylindrical exhaust gas inlet cylinder 56 is formed.

Accordingly, the top housing member 12 and the catalyst retainer 24
both have at their ends the inlet side cylindrical member 6 of the exhaust system.
0 by a weld 106 (FIGS. 4 and 6).

On the other hand, on the downstream side, as shown on the right side of FIG. 6, a portion of the downward recessed portions of both retainer members overlaps the outlet semi-cylindrical portion 64 of the top housing member 12 and extends in the axial direction, Together with the outlet half cylinder 66 of the bottom housing member 14, a cylindrical exhaust gas outlet cylinder 58 is formed.

Thus, bottom housing member 14 and catalyst retainer 24
both have at their ends the outlet side cylindrical member 6 of the exhaust system.
2 by a weld 106 (FIGS. 4 and 6).

Thus, in this embodiment, the bottom retainer member 28 is attached to the top retainer member 26 by the weld 106 on the inlet side and is also connected to the inlet cylindrical member 60 of the exhaust system, and on the outlet side. In this case, the top retainer member 26 is attached to the bottom retainer member 28 by the weld 106 and is also connected to the outlet cylindrical member 62 of the exhaust system.

Next, the top and bottom retainer members 26 of the catalyst retainer 24,
28 is integrally provided with flange portions 42 and 44 that are to be clamped by the flanges 20 and 22 over the entire periphery except for the exhaust gas inlet edge and outlet edge. The members 2628 each have imperforate sidewalls 38,40 that extend laterally therefrom to the flange portion 4244, the depth of which extends from one end of the top retainer member 26 to the other. It increases toward the end and decreases from the one end side to the other end side of the bottom retainer member 28, and when both retainer members 26 and 28 are combined with each other, a catalyst containing portion 46 is formed between them. As shown in FIGS. 6 and 11, the accommodating portion has approximately the same depth, but is inclined with respect to both housing members 12.14 so that the inlet and exhaust gases can flow together with each other. A filling chamber of decreasing cross-section is provided for the gas, thereby ensuring a fairly constant pressure gradient, and conversely a filling chamber of progressively increasing cross-section is provided for the exiting exhaust gas, thereby ensuring an approximately constant pressure gradient. It is designed to give a slope.

Said flange portions 20 of top and bottom housing members 12.14 and top and bottom retainer members 26, 28
, 22, 42, 44 are outwardly projecting surfaces 20', 20 that are interengaging with these members over substantially their entire circumference.
2', 42', 44' (Fig. 12) are given.

As shown in FIG. 6, FIG. 7, and FIG. The sandwich inch is suitably sealed by a substantially continuous circumferential weld 50 to provide internal and external sealing.

Therefore, the flange portions 42.44 provided on the peripheries of both retainer members 26.28 are clamped by the flange portions 20.22 provided on the peripheries of both housing members.

The catalytic material within the catalyst retainer 24 is thus retained within the housing 10, with the side wall portions 38, 40 at at least both ends of the catalyst retainer 24 being spaced inwardly from the side wall portions 16, 18 of the housing 10. Spaces 52 and 54 (Fig. 6) are carved between the two.

The upward concave portion, the downward concave portion, and the flange portion together with the porous portion of the holder 24 allow the exhaust gas introduced into the gas inlet to pass through the catalyst 4 accommodated in the catalyst holder 24.
8.

In a preferred form, the exhaust gas inlet cylinder 56 is displaced slightly upward relative to the axial direction of the catalytic converter, while the exhaust gas outlet cylinder 58 is displaced slightly downward to smooth the gas flow. It looks like this.

The angle of displacement between the exhaust gas inlet cylinder 56 and the outlet cylinder 58 may vary depending on the position of the catalytic converter within the exhaust system.

With this configuration, as shown in FIGS. 6 and 7, an inlet filling chamber 76 is formed in the Ujifugu 10 and communicates with the exhaust gas inlet cylindrical portion 56, which is connected to the top retainer member 26.
It includes a space 52 extending around the .

Similarly, an outlet fill chamber 78 is formed within the housing 10 that communicates with the exhaust gas outlet barrel 58 and includes a space 54 that extends around the bottom retainer member 28 .

The catalytic converter described above has an inclined catalyst bed which slopes upwardly from the inlet cylinder 56 to the outlet cylinder 58 as shown in FIG. Exhaust gas enters from the inlet plenum 16 into both retainer members 26,28 and the catalytic material 4 held therein.
8 and should pass downward.

In general, the lower part of the passenger compartment of a car is lower than the lower part of the trunk. Because the catalyst bed is relatively shallow in depth but relatively large in volume, its height is relatively small compared to its length, making it suitable for use in locations within the exhaust gas system relatively close to the engine. This creates a catalytic converter that can be easily installed on the vehicle, which is effective because it ensures rapid warm-up of the catalytic converter compared to a catalytic converter that must be placed in the normal exhaust muffler location. It is possible to perform exhaust gas treatment (that satisfies exhaust gas regulation standards).

The slanted catalyst bed and downward flow of exhaust gas ensure an even flow distribution of exhaust gas within the catalytic converter while minimizing fluidization and movement of catalyst particles.

Although the catalytic converter was described above as having exhaust gas flowing downwardly through an upwardly sloping catalyst bed from inlet to outlet, the gas flow can be reversed so that exhaust gas flows downwardly from inlet to outlet. The flow may flow upwardly through a downwardly sloping bed.

As shown in FIGS. 5-10, the top clamp member 12 and bottom housing member 14 include a plurality of recesses 8.
0 is formed through which an aperture 82 extends, the recess being a top and bottom retainer member 26 having a corresponding aperture 83.
．． 28 (Fig. 10).

Support studs 84 are connected to catalyst retainer 24 , catalyst 48 , opening 83 in catalyst retainer 24 and recess 80 in housing 10 .
It passes through the opening 82 of.

Each end of the stud 84 is formed with a shoulder 86 upon which the top and bottom porous portions 30.34 of both retainer members 26.28 are seated.

Openings 82 are located at the top and bottom...clamping members 12.14.
It is surrounded by an annular lip portion 88 extending outwardly from the bottom.

The lip portion 88 is shaped so that the fit between it and the stud 84 is relatively loose, the lip portion 88 is welded to the stud 84, and a recess around the annular lip portion 88 is then formed. A reinforcing washer 90 is fitted within 80 and secured by a continuous annular weld 94 (FIG. 9), thereby welding the two members together.

Housing 1 by using studs and reinforcing washers
0 and the catalyst holder is considerably strengthened, resulting in a structure with high strength and resistance to deformation even at high temperatures and pressures.

As shown in other embodiments of the invention illustrated in FIGS. 2 and 3, the top and bottom porous portions 30, 34 of the retainer members 26, 28 optionally include stiffening ribs 96.
may be formed.

However, it has been found that the sagging of the catalyst retainer 24 and the obstruction of the exhaust gas flow under high temperatures can also be reduced by not using the ribs but by reducing the number of shutter windows 32', as shown in FIG. are doing.

A top cover 98 is provided above the top housing member 12 and therebetween is a material such as ceramic wool to protect the catalytic converter from heat loss and to protect the lower body of the vehicle from the heat of the catalytic converter. A thermal insulation layer 100 is interposed.

Similarly, a bottom cover 9 is also provided below the bottom housing member 14.
9 are provided, and a bottom housing member 14 and a bottom cover 9 are provided.
A further thermal insulation layer 101 is interposed between 9 to reduce heat losses through the catalytic converter bottom.

The top cover 98 is provided with a U-shaped flange 102 and the bottom cover 99 is provided with a flange portion 97 that connects the edge-sealed flange portion 20.22 of the housing 10 and the flange portion 97 of the bottom cover 99. the top and bottom covers 9
8.99 is appropriately fixed to the housing 10.

Top cover 98 also includes ribs 103 to increase its rigidity.
It is equipped with

In manufacturing and assembling the catalytic converter described above, the top housing member 12 and the bottom housing member 14 of the housing 10 are formed as substantially identical stampings, including the recess 80 and its through opening 82, as a single piece. Since the two parts that can be made by the same die forming operation are substantially identical, they may be formed using similar dies as appropriate, and in this case the parts can be produced and stored economically.

Both cage parts 26, 28 may likewise be formed from the same die, in which case both cage parts are interchangeable during assembly.

If desired, the retainer members and covers 98, 99 on one of the housing members 12,14 and closer thereto are removed prior to assembly.
holes 104, 105, 107 are provided in the side walls, respectively, as shown in FIG. 12, through which probes can be passed after assembly to monitor the temperature and activity of the catalyst bed. You may also do so.

In the preferred embodiment of the invention, this is the only point in which these members differ from each other.

Next, when the four members 12, 14 and 26, 28 are assembled through the studs 84 and set in the mounting device, the surfaces 20', 22', 42', and 44' of the flange portions abut, forming a four-layer sandwich inch. It is formed and then sealed by a single substantially continuous peripheral weld on its outer periphery to provide an internal and external seal.

The welding sequence is preferably automatic, with the parts standing sideways on a mounting device with their periphery exposed facing a vertically mounted electron beam welder, and turning the parts to create a nearly continuous welding process. A weld is formed.

Next, the washer 90 is placed in position and the welded portion 9 of the lip portion 88 is
4 to stud 84 and lip portion 88, preferably by electron beam welding.

Next, the inlet and outlet side cylindrical members 60.6 of the exhaust system
2 into the inlet cylindrical portion 56 and outlet cylindrical portion 58 of the transducer, respectively, and then a continuous peripheral weld is made (106).
4), in the inlet cylindrical portion 56, the inlet side cylindrical member 60 is connected to the top housing member 12 and the top retainer member 26.
, directly connected to each of the bottom retainer member 28 and the bottom housing member 14 by welding (left end in FIG. 6),
On the other hand, in the outlet cylindrical portion 58, the outlet side cylindrical member 662 is directly connected to each of the bottom housing member 14, the top retainer member 26, the bottom retainer member 28, and the top housing member 12 by welding (the sixth right side of the figure).

This allows the top retainer member 26 and the bottom retainer member 28 to
The catalyst holder 2 is connected by continuous welding around its entire circumference.
This will constitute 4.

Finally, the catalyst substance 48 is put into the catalyst housing part 46 of the catalyst holder 24 through the filling hole 108 (FIGS. 6 and 12),
A threaded bushing 109 is fixed within the filling socket by welding.

Preferably, the catalytic converter is vibrated during the charging operation to ensure complete packing of the material therein.

Next, if the removable plug 110 is screwed into the bushing, even when the catalytic converter is installed in an automobile, the catalyst can be replaced by providing the plug at the bottom of the catalytic converter.

Next, after installing insulation layers 100° 101 on the top and bottom of the housing 10, the U-shaped 72 of the top cover 98 is placed around the periphery of the weld 50 and the flange portion 97 of the bottom cover 99.
72 parts 102 may be crimped.

In operation, gas from the internal combustion engine is directed into the inlet cylindrical portion 56 and into the inlet filling chamber 7 by the inlet side cylindrical member 60.
6, the gas encapsulates the top retainer member 26 of the catalyst retainer 24 and then flows downwardly through the openings 32 in the top porous portion 30 of the catalyst retainer 24, passing through and within the catalyst material 48. Oxidation and/or reduction reactions occur.

The treated gas flows out of the opening 36 in the bottom porous portion 34 of the catalyst retainer 24 and is collected in the outlet plenum 78, and then the treated gas flows from the outlet cylindrical portion 58 to the outlet side cylindrical member 6.
2 and is discharged into the atmosphere through the tail pipe of the exhaust system.

The embodiments of the present invention shown in FIGS. 1 to 3 are as shown in FIGS. 4 to 12.
A lip 96 similar to the embodiment shown, but pressed into the catalyst retainer with a bottom cover plate and a thermally insulating layer.
Further, as is clear from FIGS. 1 and 2, the exhaust gas inlet edge of the bottom retainer member does not reach the exhaust gas inlet edge of the top retainer member and the bottom housing member,
In this embodiment, the bottom retainer member is attached to the top retainer member by being sandwiched between the top retainer member and the bottom housing member near the exhaust edge of the bottom retainer member; The gas outlet edge does not extend to the exhaust gas outlet edges of the bottom retainer member and the top housing member, and in this embodiment the top retainer member is adjacent to the bottom retainer member and the top housing member near its exhaust gas outlet edges. The two layers are each welded to the cylindrical member of the exhaust system at the lower left and upper right in FIG. 1, respectively.

That is, only the top retainer member 26 has an upward recess that is directly connected to the inlet cylindrical member 60 of the exhaust system, and the bottom retainer member has a downward recess that is directly connected to the outlet cylindrical member 62 of the exhaust system. Only 28 have it.

Also, the exhaust gas outlet edge of the flange portion of the bottom retainer member does not reach the exhaust gas outlet edge of the flange portion of the top retainer member and the bottom housing member, and the exhaust gas outlet edge of the flange portion of the top retainer member The part also does not reach the exhaust gas outlet edge of the flange part of the bottom retainer member and the top housing member, so that on the inlet side only the flange part of the top retainer member is still present, while on the outlet side only the flange part of the bottom retainer member Only the flange portion of the housing member is narrowed by the flange portions of the top and bottom housing members.

In this case, the top retainer member and the bottom retainer member are not continuously welded to each other at the exhaust gas port edge and the exhaust outlet edge, but even if a gas leak occurs in this area, the leak circulating around the catalyst will There is no problem because it will not happen.

The other points and the parts other than the fish flesh mentioned in the description of the embodiments in FIGS. 4 to 12 are the same as the embodiments in FIGS. 4 to 12.

The effects of the present invention will be explained below.

According to the invention, first of all, a transducer having a low profile and a relatively shallow depth can be changed.

That is, (1) as shown in the claims, the top and bottom retainer members have a substantially uniform depth and a catalyst housing that slopes upwardly from the exhaust gas inlet to the exhaust gas outlet; form a section.

This advantage is extremely important.

This is because this converter is designed to be mounted on the underside of a passenger car.

That is, since the bottom of the passenger area is lower than the bottom of the trunk, a shallow transducer is required to avoid hitting obstacles on the ground.

The catalyst housing of the present invention is simply formed by assembling four members: top and bottom retainer members and top and bottom housing members.

This combination provides a relatively large capacity catalyst bed at a relatively shallow depth, and the converter's housing is constructed with a relatively low height relative to its length, making this converter comparable to engines. It can be easily installed in the vehicle at a desired location within the exhaust gas system in close proximity to the vehicle, allowing for faster and more effective warm-up of the converter than with catalytic converters, which normally have to be located as part of the exhaust muffler. Exhaust gas treatment is possible.

Second, the converter of the present invention provides a uniform pressure gradient and reduced resistance to gas flow due to the slightly sloped catalyst bed.

That is, (1) the dish-shaped portions of the top and bottom retainer members increase and decrease in depth, respectively, from the exhaust gas inlet to the outlet.

This advantage is important.

This is because gas flow through the catalyst bed is nearly uniformly distributed for maximum catalyst life and optimal catalytic conversion.

The top and bottom retainer members define slightly sloping catalyst receptacles of approximately uniform depth, with varying spacing from the top and bottom housing members.

The spacing between the top retainer member and the top housing portion decreases sequentially from the exhaust gas inlet to the outlet, forming a progressively decreasing cross section for the incoming exhaust gas flow, creating an approximately constant pressure gradient. Give.

Similarly, the spacing between the bottom retainer member and the bottom housing member increases progressively from the gas inlet to the outlet, creating a progressively increasing cross section for the incoming exhaust gas flow and imparting a more or less constant pressure gradient. do.

Reducing the resistance to gas flow is also achieved by extending retainer structures at the inlet and outlet sections that define the flow of gas into and out of the protector.

The structure of this catalytic converter creates a streamlined gas flow,
Facilitates the inflow and outflow of flowing exhaust gas.

In the present invention, these effects are achieved in that the dish-shaped portions of the top and bottom retainer members increase and decrease in depth, respectively, from the exhaust gas inlet to the outlet.

Third, in the converter of the present invention, there is no leakage that circulates around the catalyst housed in the slightly inclined catalyst housing.

That is, (1) as shown in the claims, one of the two retainer members (both the top retainer member has an upward concave portion at one end and is directly connected to the cylindrical member on the inlet side of the exhaust system); The upwardly recessed portion is integrally formed of the same material as the dish-shaped portion, and the upwardly recessed portion extends from the catalyst receiving portion to the inlet channel in a non-perforated state, and a portion of the upwardly recessed portion is formed in the inlet semi-cylindrical portion of the bottom housing member. extending axially with the inlet half cylinder of the top housing member to form a cylindrical exhaust gas inlet cylinder, in which both the top housing member and the catalyst retainer are connected to the exhaust gas inlet cylinder. at least the bottom retainer member is directly connected to the outlet cylindrical member of the exhaust system and is made of the same material as the dish-shaped portion thereof; A downward recess integrally formed with the top housing is provided at the other end, and the downward recess extends in a non-porous manner from the catalyst receiving portion to the outlet flow path, and a portion of the downward recess is formed in the top housing. overlapping and axially extending with the outlet semi-cylindrical portion of the member to form, together with the outlet semi-cylindrical portion of the bottom housing member, a cylindrical exhaust gas outlet cylinder; Both catalyst retainers are directly connected to the outlet side cylindrical member of the exhaust system; the flange portion of the retainer member is sandwiched between the housing members.

and (2) as claimed in the claims, wherein the top and bottom retainer members form a sloped catalyst receiving portion of substantially uniform depth that slopes upwardly from the exhaust gas inlet to the exhaust gas outlet. and the dish-shaped portions of the top and bottom retainer members have depths that increase and decrease, respectively, from the exhaust gas inlet to the outlet.

This advantage is extremely important.

In other words, (1) If a leak circulating around the catalyst occurs around the catalyst holder, harmful untreated gases will be emitted as they are to the outside air. Extend.

Fourthly, the converter of the present invention solves the following problem.

(1) The catalyst retainer is firmly supported within the housing. (2) The retainer and both housing members are directly connected to the exhaust system.

This promotes strong support, and since there is no leakage that would quickly circulate the catalyst, it is possible to reliably separate the harmful exhaust gases at the inlet from the clean exhaust gases at the outlet.

That is, (1) As described in the claims, the upward concave portion
・A cylindrical exhaust gas inlet cylindrical portion is formed together with the inlet semi-cylindrical portion of the housing member, and in the inlet cylindrical portion, the top...
Both the housing member and the catalyst retainer are adapted to be directly connected to the inlet side cylindrical member of the exhaust system; and the downwardly directed recess forms a cylindrical exhaust gas outlet cylindrical portion together with the outlet semi-cylindrical portion of the bottom housing. , in the outlet cylindrical portion, both the bottom housing member and the catalyst retainer are directly connected to the outlet cylindrical member of the exhaust system.

This advantage is extremely important.

That is, (1) being strong is an important requirement for the self-supporting nature of the converter and proper support within the exhaust system.

This is because the inlet of the transducer moves with the vibrations of the engine relative to the vehicle frame, to which the outlet of the transducer is directly connected.

The catalyst retainer is directly attached to one of the cylindrical members of the exhaust system by welding.
The catalytic converter is made self-supporting by connecting each housing member directly to one of the cylindrical members of the exhaust system by welding.

This results in increased rigidity of the exhaust system and increased durability of the self-supporting catalyst holder itself.

(iD) The stiffness of self-supporting catalytic converters is improved by the retainer reinforcing the housing and preventing housing damage due to relative movement between the engine and the vehicle frame.

This) housing reinforcement has an extension at each top and bottom that is directly connected to the extension of the catalyst holder, and at which the converter is connected to the cylindrical member of the exhaust system. This is achieved by

At each end, the extensions of the catalyst retainer extend axially, overlapping with respective extensions of the housing member, which are welded directly at each end to the cylindrical member of the exhaust system. The rigidity is further strengthened by the connection.

The invention also has new and important features.

The holder extends upstream beyond the catalyst accommodating part under the inflowing exhaust gas, without thereby reducing the catalyst accommodating space, and the holder extends beyond the catalyst accommodating part above the exhaust gas. It extends in the downstream direction without holes, thereby not reducing the catalyst accommodating portion, thereby maintaining a sufficient effective volume of the catalyst holding space, and preventing leakage of exhaust gas from passing around the catalyst.

A) The extension part has (1) appropriate catalyst capacity, (2) combined with the flange part, the exhaust gas flows into the gas inlet and always passes through the catalyst, and (3) the inevitable temperature gradient and sudden temperature gradient in the catalytic converter. To provide an extremely robust device that can sufficiently withstand thermal stress caused by severe temperature changes.

B) The top and bottom retainer members (1) combine with the top and bottom housing members to provide a slightly sloped catalyst housing, and (2) increase and decrease in depth, respectively, from the exhaust gas inlet to the outlet. The transducer has a dish-shaped portion which cooperates with the extension to allow easy flow into and out of the transducer.

This feature provides less resistance to gas inflow.

Since the catalytic converter according to the invention can be manufactured by simply assembling four main parts in its final assembly stage, the number of connections and therefore the number of seams can be reduced to a minimum.

This reduces the possibility of wear-and-tear damage and the possibility of leaks that can rapidly deactivate the catalyst.

Furthermore, the simple structure and design reduce the amount of steel used.
Reduces warm-up time to warm up the catalyst and reach effective operating temperature.

However, the simple structure reduces the possibility of errors in mass production.

As described above, the present invention relates to the invention described in the claims, and further has one or more of the following features in practice.

(1) The top and bottom retainer members have upward recesses and downward recesses.

(2) Each retaining member is made of a single integral piece of material.

(3) The perforated portion of the cage is a part of the cage formed by pressing into an arc shape.

(4) a top cover overlying the top housing member having a peripheral flange crimped onto the sealed peripheral ends of the housing member and retainer member and a layer 100 of thermally insulating material;
is located between the top cover and the crimp member.

(5) A bottom cover is attached to the bottom crimp member and a layer of thermally insulating material is placed between the bottom crimp member and the bottom cover.

[Brief explanation of drawings]

Fig. 1 is a partially sectional side view (II sectional view in Fig. 2) of an embodiment of a catalytic converter according to the present invention, and Fig. 2 is a reduced plan view of Fig. 1 to show the internal structure. Partially cut away figure, 3rd
1, FIG. 4 is a side view of another preferred embodiment of the catalytic converter according to the present invention, and FIG.
The figure is a plan view of Fig. 4, with a part cut away to show the internal structure, and Fig. 6 is a cross-sectional view taken along the line Vl-Vl of Fig. 5.
Figure 7 is a sectional view taken along the line ■-■ in Figure 4, Figure 8 is an enlarged fragmentary sectional view taken along the line ■-■ in Figure 5, and Figure 9 is an enlarged plan view of a part of Figure 5. A diagram showing some of the internal welding,
FIG. 10 is a cross-sectional view taken along line X-X in FIG. 9, FIG. 11 is an enlarged fragmentary side view taken along line xt-xt in FIG. 5, and FIG. 12 is a cross-sectional view of the catalyst shown in FIGS. 4 to 11. FIG. 3 is an exploded perspective view of a transducer embodiment. Explanation of reference symbols of main parts 10...Crimp, 12. '14...Top and bottom housing members, 24...Catalyst retainer, 26.28...Top and bottom retainer members, 30.34...Porous portion, 4
6... Catalyst housing section, 48... Catalyst material, 56...
Exhaust gas inlet cylindrical part, 58...exhaust gas outlet cylindrical part,
64... Semi-cylindrical part of the top housing member, 66...
Semi-cylindrical portion of bottom housing member, 60... Cylindrical member on the inlet side of the exhaust system, 62... Cylindrical member on the outlet side of the exhaust system, 20°22... Flange portion of the housing, 42.4
4...Flange part of the catalyst holder.

Claims (1)

Claims: 1. Exhaust gas flows past a catalyst contained within a catalyst retainer within a housing, the housing having top and bottom housing members each having a dish-shaped portion. and surrounding the catalyst holder with the two dish-shaped parts:
The plate-shaped portions have a semi-cylindrical portion forming a cylindrical exhaust gas inlet passage and an outlet passage, the inlet passage and the outlet passage being axially away from the catalyst receiving portion of the catalyst holder. The catalyst accommodating portion of the catalyst holder has a porous portion forming an exhaust gas passage passing through the catalyst, and
Further, in an exhaust gas catalytic converter for an internal combustion engine, wherein the catalyst retainer has a flange portion sandwiched between flange portions extending around the periphery of a housing member: the catalyst retainer (e.g. 24) includes top and bottom retainers; the top and bottom cage members each have a dish-shaped portion forming the catalyst housing, and the top cage member of both cage members is provided with an exhaust system. directly connected to the inlet side cylindrical member of the inlet side cylindrical member, and
An upward concave portion integrally formed of the same material as the dish-shaped portion is provided at one end thereof, and the upward concave portion extends from the catalyst accommodating portion into the inlet channel in a non-perforated state. A portion of the recess overlaps and extends axially with said inlet half cylinder (e.g. 66) of a bottom housing member (e.g. 14) to form an inlet half cylinder (e.g. 64) of a top housing member (e.g. 12). ) together with a cylindrical exhaust gas inlet cylinder (e.g. 56
), and in the inlet cylindrical part, both the top housing member and the catalyst retainer are directly connected to the inlet side cylindrical member of the exhaust system: the bottom retainer of both retainer members The other end of the member is provided with a downward recess that is directly connected to the cylindrical member on the outlet side of the exhaust system and is formed integrally with the same material as the dish-shaped portion, and the downward recess is connected to the catalyst. extending imperforately from the receiving portion to the outlet flow path, a portion of the downwardly recessed portion overlapping and axially extending the outlet semi-cylindrical portion (e.g. 64) of the top housing member (e.g. 12); to form a cylindrical exhaust gas outlet cylinder (e.g. 58) together with the outlet semi-cylindrical portion (e.g. 66) of the bottom housing member (e.g. 14), in which both the bottom housing member and the catalyst retainer are disposed. is directly connected to the outlet side cylindrical member of the exhaust system, and the artificial semi-cylindrical part, the dish-shaped part and the outlet semi-cylindrical part constituting the top and bottom housing members are each integrally made of the same material. A flange portion of the housing is integrally provided on the peripheral edge portions of the two top and bottom housing members formed so as to cover the entire periphery excluding the exhaust gas port edge and the outlet edge,
Furthermore, the flange portion of the catalyst holder is integrally provided on the entire periphery of the top and bottom cage members except for the exhaust gas manifold edge and the outlet edge, and a flange portion provided on the housing member is sandwiched between flange portions provided on the peripheral edge portions of both housing members;
Additionally, the top and bottom retainer members (e.g. 26.28 are
have a substantially uniform depth and an exhaust gas inlet (e.g. 5
6) to the exhaust gas outlet (e.g. 58); ) Exhaust gas catalytic converter for an internal combustion engine, characterized in that the depth increases and decreases, respectively, towards.