CA1333696C - Catalyzing system - Google Patents
Catalyzing systemInfo
- Publication number
- CA1333696C CA1333696C CA 603771 CA603771A CA1333696C CA 1333696 C CA1333696 C CA 1333696C CA 603771 CA603771 CA 603771 CA 603771 A CA603771 A CA 603771A CA 1333696 C CA1333696 C CA 1333696C
- Authority
- CA
- Canada
- Prior art keywords
- catalyst
- exhaust manifold
- primary
- case
- catalyzing system
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Landscapes
- Exhaust Gas After Treatment (AREA)
Abstract
Herein disclosed is a catalyzing system for an automotive engine, which comprises: a primary reducing catalyst and a secondary oxidizing catalyst arrayed in tandem just downstream of an exhaust manifold, the primary catalyst being accommodated in the exhaust manifold; and a catalyst case connected to the exhaust manifold and accommodating the secondary catalyst; and a secondary air inlet port formed in the flanged por-tions of the exhaust manifold and the catalyst case.
Alternatively, the catalyzing system comprises: a pri-mary reducing catalyst and a secondary oxidizing cata-lyst arrayed in tandem just downstream of an exhaust manifold, the primary catalyst being accommodated in the exhaust manifold; and a space defined between the primary and secondary catalysts by extending the ex-haust manifold at its primary catalyst holding portion to the secondary catalyst.
Alternatively, the catalyzing system comprises: a pri-mary reducing catalyst and a secondary oxidizing cata-lyst arrayed in tandem just downstream of an exhaust manifold, the primary catalyst being accommodated in the exhaust manifold; and a space defined between the primary and secondary catalysts by extending the ex-haust manifold at its primary catalyst holding portion to the secondary catalyst.
Description
1333~9~
CATALYZING SYSTEM
The present invention relates to a catalyzing system to be connected for use with an automotive engine.
Since an automotive engine exhausts a variety of noxious contents, various devices have been made to reduce the noxious contents to a predetermined level.
One method practised for the devices with satisfactory results is exemplified by using a catalyst. In this example, as shown in Fig. 7, a catalyzing system 1 is constructed such that there are arranged in tandem in a catalyst case 4 (which will be shortly referred to as the "case") a primary reducing catalyst 5 for mainly reducing nitrogen oxides,NOx,and a secondary oxidizing catalyst 6 for mainly oxidizing carbon monoxide CO and hydrocarbons HCand such that secondary air is supplied toward the oxidizing catalyst 6 from between the re-- 1 - ~ ,~,., 1333~3f;
ducing catalyst 5 and the oxidizing catalyst 6. This structure is known to give the satisfactory results (as disclosed in Japanese Utility Model Laid-Open No. Sho 58-118212).
In order to make this structure, according to the prior art, the case 4 is connected to an exhaust mani-fold 3, as shown in Fig. 7, and the reducing catalyst 5 and the oxidizing catalyst 6 are fitted in the case 4 through holding members 7 and 8. Since the oxidizing catalyst 6 of the two has to be supplied with secondary air, secondary air passages 9 and 10 are formed for both the exhaust manifold 3 and the case 4 so that the secondary air may be supplied through a not-shown se-condary air supply tube.
When the secondary oxidizing catalyst 6 is fitted in the case 4 of the catalyzing system of such struc-ture, the holding member 8 is wound around the oxi-dizing catalyst 6. Even with elaborate cares for the working, therefore, the holding member 8 is frequently caught by the outlet port (i.e., the downstream exist of the secondary air passage 10) of the secondary air so that the oxidizing catalyst 6 cannot be well press-fitted in the case 4. Another problem is that the holding force of the oxidizing catalyst 6 will drop.
CATALYZING SYSTEM
The present invention relates to a catalyzing system to be connected for use with an automotive engine.
Since an automotive engine exhausts a variety of noxious contents, various devices have been made to reduce the noxious contents to a predetermined level.
One method practised for the devices with satisfactory results is exemplified by using a catalyst. In this example, as shown in Fig. 7, a catalyzing system 1 is constructed such that there are arranged in tandem in a catalyst case 4 (which will be shortly referred to as the "case") a primary reducing catalyst 5 for mainly reducing nitrogen oxides,NOx,and a secondary oxidizing catalyst 6 for mainly oxidizing carbon monoxide CO and hydrocarbons HCand such that secondary air is supplied toward the oxidizing catalyst 6 from between the re-- 1 - ~ ,~,., 1333~3f;
ducing catalyst 5 and the oxidizing catalyst 6. This structure is known to give the satisfactory results (as disclosed in Japanese Utility Model Laid-Open No. Sho 58-118212).
In order to make this structure, according to the prior art, the case 4 is connected to an exhaust mani-fold 3, as shown in Fig. 7, and the reducing catalyst 5 and the oxidizing catalyst 6 are fitted in the case 4 through holding members 7 and 8. Since the oxidizing catalyst 6 of the two has to be supplied with secondary air, secondary air passages 9 and 10 are formed for both the exhaust manifold 3 and the case 4 so that the secondary air may be supplied through a not-shown se-condary air supply tube.
When the secondary oxidizing catalyst 6 is fitted in the case 4 of the catalyzing system of such struc-ture, the holding member 8 is wound around the oxi-dizing catalyst 6. Even with elaborate cares for the working, therefore, the holding member 8 is frequently caught by the outlet port (i.e., the downstream exist of the secondary air passage 10) of the secondary air so that the oxidizing catalyst 6 cannot be well press-fitted in the case 4. Another problem is that the holding force of the oxidizing catalyst 6 will drop.
It is an object of the present invention to provide a system which obviates or mitigates at least one of the above-mentioned disadvantages.
According to an aspect of the present invention there is provided a catalyzing assembly for reducing noxious components from an engine exhaust manifold, comprising:
(a) a generally cylindrical housing comprising an integral extension portion of the exhaust manifold, said housing having an inner wall surface defining a chamber having an open end and including an integral annular flange extending radially outwardly therefrom;
(b) a primary reducing catalyst arranged and retained within said housing chamber via said open end and extending between the inner wall surface of said housing;
(c) a generally cylindrical case having an inner wall surface defining a chamber having an open end and including an integral annular flange extending radially outwardly therefrom;
(d) a secondary oxidizing catalyst arranged and retained within said case chamber via said open end and extending between the inner wall surface of said case;
(e) means for connecting said case and housing flanges together with said case and housing open ends facing each other and with said case and said housing chambers being arranged coaxially in spaced relation, thereby to define a space between said primary and secondary catalysts arranged in tandem; and (f) means for supplying secondary air to the space between said catalysts for an oxidation reaction of said secondary catalyst.
According to an aspect of the present invention there is provided a catalyzing assembly for reducing noxious components from an engine exhaust manifold, comprising:
(a) a generally cylindrical housing comprising an integral extension portion of the exhaust manifold, said housing having an inner wall surface defining a chamber having an open end and including an integral annular flange extending radially outwardly therefrom;
(b) a primary reducing catalyst arranged and retained within said housing chamber via said open end and extending between the inner wall surface of said housing;
(c) a generally cylindrical case having an inner wall surface defining a chamber having an open end and including an integral annular flange extending radially outwardly therefrom;
(d) a secondary oxidizing catalyst arranged and retained within said case chamber via said open end and extending between the inner wall surface of said case;
(e) means for connecting said case and housing flanges together with said case and housing open ends facing each other and with said case and said housing chambers being arranged coaxially in spaced relation, thereby to define a space between said primary and secondary catalysts arranged in tandem; and (f) means for supplying secondary air to the space between said catalysts for an oxidation reaction of said secondary catalyst.
A
According to another aspect of the present invention there is provided a catalyst system comprising: a primary reducing catalyst and a secondary oxidizing catalyst arrayed in tandem just downstream of an exhaust manifold, said primary catalyst being accommodated in said exhaust manifold; and a space defined between said primary and secondary catalysts by extending said exhaust manifold at its primary catalyst holding portion to said secondary catalyst.
Thanks to these structures, when the secondary oxidizing catalyst is to be accommodated in the (catalyst) case, its accommodated portion is positioned at end face of the case so that the holding member is kept away from contact with the outlet port of the secondary air unlike the prior art. In the second means, on the - 3a-A
other hand, the exhaust manifold extended to the oxi-dizing catalyst 6 performs the function of the spacer of the catalyzing system of the prior art so that the secondary air can be well distributed without providing any spacer separately.
Embodiments of the invention will be described with reference to the accompanying drawings in which:
Fig. 1 is a section showing one embodiment of the present invention;
Fig. 2 is a section showing another embodiment of the present invention;
Fig. 3 is a section taken along line III - III of Fig. 2;
Fig. 4 is a section showing an essential portion showing a modification of the embodiment of Fig. 3;
Fig. 5 is a section showing still another embodi-ment of the present invention;
Fig. 6 is a section taken along line VI - VI of Fig. 5; and Fig. 7 is a section showing the catalyzing system of the prior art.
The present invention will be described in the following in connection with its one embodiment with 133369~
reference to Fig. 1. As is apparent in comparison with Fig. 7, the primary reducing catalyst 5 is accommodated in the exhaust manifold 3. A secondary air supply tube 11 has its leading end inlet port lla opened in the flanged face between the exhaust manifold 3 and the case 4. In this embodiment, a spacer 13 is formed between the reducing catalyst 5 at the side of the exhaust manifold 3 and the oxidizing catalyst 6 at the side of the case 4 so that secondary air may be blown to the oxidizing catalyst 6 from pores 13a which are formed in the spacer 13. Designated at reference nume-ral 14 are bolts which fasten the exhaust manifold 3 and the case 4 at the flanged portions.
In the catalyzing system 1 thus constructed, the primary reducing catalyst 5 can be easily mounted from the opening at the side of the exhaust manifold 3, and the secondary oxidizing catalyst 6 can also be easily mounted from the opening at the side of the case 4.
After these two catalysts 5 and 6 have been mounted, the spacer 13 is sandwiched, and the flanged portions are fastened by means of the bolts 14. The secondary air is introduced into the spacer 13 through the inlet port lla at the leading end of the secondary air supply tube 11.
Fig. 2 shows another embodiment of the present 133369~
invention. In this embodiment, the primary catalyst 5 is accommodated in the exhaust manifold 3, and this holding portion of the manifold 3 is extended to the secondary catalyst 6 to define a space between the two catalysts 5 and 6. As a result, this embodiment can dispense with the spacer 13 which was required by the embodiment of Fig. 1. In this embodiment, the flanged portion of the case 4 is extended upward, as shown in Fig. 3, to open a connecting port 15 for the secondary air supply tube 11 (as shown in Fig. 1). As shown in Fig. 4, on the other hand, the flanged portion of the exhaust manifold 3 may be extended to form the connec-ting portion 15.
Fig. 5 shows still another embodiment of the pre-sent invention. In this embodiment, the exhaust mani-fold 3 is extended toward the secondary catalyst 6, and the case 4 is extended around the extension of the manifold 3 to form inbetween an annular passage 16 for the secondary air (as shown in Fig. 6). This passage 16 is connected at the connecting port of the flanged portions to the secondary air supply tube 11 (as shown in Fig. 1). With this structure, the secondary air supplied from the connecting port 15 is swirled, while it is passing through the annular passage, so that it is uniformly supplied to the oxidizing catalyst 6.
Since the first embodiment of the present inven-tion provides the catalyzing system having the struc-ture thus far described, the primary reducing catalyst and secondary oxidizing catalyst can be easily mounted from the openings at the sides of the exhaust manifold and the case, respectively, before the exhaust manifold and the case are connected for the assembly. Unlike the prior art, the holding member is neither caught nor peeled because the two catalysts are not sequentially inserted from the common opening. In addition to the above-specified effect, according to the second embodi-ment, the portion of the exhaust manifold extended to the oxidizing catalyst performs the function of the spacer of the catalyzing system of the prior art so that the secondary air can be sufficiently distributed without providing any spacer separately.
According to another aspect of the present invention there is provided a catalyst system comprising: a primary reducing catalyst and a secondary oxidizing catalyst arrayed in tandem just downstream of an exhaust manifold, said primary catalyst being accommodated in said exhaust manifold; and a space defined between said primary and secondary catalysts by extending said exhaust manifold at its primary catalyst holding portion to said secondary catalyst.
Thanks to these structures, when the secondary oxidizing catalyst is to be accommodated in the (catalyst) case, its accommodated portion is positioned at end face of the case so that the holding member is kept away from contact with the outlet port of the secondary air unlike the prior art. In the second means, on the - 3a-A
other hand, the exhaust manifold extended to the oxi-dizing catalyst 6 performs the function of the spacer of the catalyzing system of the prior art so that the secondary air can be well distributed without providing any spacer separately.
Embodiments of the invention will be described with reference to the accompanying drawings in which:
Fig. 1 is a section showing one embodiment of the present invention;
Fig. 2 is a section showing another embodiment of the present invention;
Fig. 3 is a section taken along line III - III of Fig. 2;
Fig. 4 is a section showing an essential portion showing a modification of the embodiment of Fig. 3;
Fig. 5 is a section showing still another embodi-ment of the present invention;
Fig. 6 is a section taken along line VI - VI of Fig. 5; and Fig. 7 is a section showing the catalyzing system of the prior art.
The present invention will be described in the following in connection with its one embodiment with 133369~
reference to Fig. 1. As is apparent in comparison with Fig. 7, the primary reducing catalyst 5 is accommodated in the exhaust manifold 3. A secondary air supply tube 11 has its leading end inlet port lla opened in the flanged face between the exhaust manifold 3 and the case 4. In this embodiment, a spacer 13 is formed between the reducing catalyst 5 at the side of the exhaust manifold 3 and the oxidizing catalyst 6 at the side of the case 4 so that secondary air may be blown to the oxidizing catalyst 6 from pores 13a which are formed in the spacer 13. Designated at reference nume-ral 14 are bolts which fasten the exhaust manifold 3 and the case 4 at the flanged portions.
In the catalyzing system 1 thus constructed, the primary reducing catalyst 5 can be easily mounted from the opening at the side of the exhaust manifold 3, and the secondary oxidizing catalyst 6 can also be easily mounted from the opening at the side of the case 4.
After these two catalysts 5 and 6 have been mounted, the spacer 13 is sandwiched, and the flanged portions are fastened by means of the bolts 14. The secondary air is introduced into the spacer 13 through the inlet port lla at the leading end of the secondary air supply tube 11.
Fig. 2 shows another embodiment of the present 133369~
invention. In this embodiment, the primary catalyst 5 is accommodated in the exhaust manifold 3, and this holding portion of the manifold 3 is extended to the secondary catalyst 6 to define a space between the two catalysts 5 and 6. As a result, this embodiment can dispense with the spacer 13 which was required by the embodiment of Fig. 1. In this embodiment, the flanged portion of the case 4 is extended upward, as shown in Fig. 3, to open a connecting port 15 for the secondary air supply tube 11 (as shown in Fig. 1). As shown in Fig. 4, on the other hand, the flanged portion of the exhaust manifold 3 may be extended to form the connec-ting portion 15.
Fig. 5 shows still another embodiment of the pre-sent invention. In this embodiment, the exhaust mani-fold 3 is extended toward the secondary catalyst 6, and the case 4 is extended around the extension of the manifold 3 to form inbetween an annular passage 16 for the secondary air (as shown in Fig. 6). This passage 16 is connected at the connecting port of the flanged portions to the secondary air supply tube 11 (as shown in Fig. 1). With this structure, the secondary air supplied from the connecting port 15 is swirled, while it is passing through the annular passage, so that it is uniformly supplied to the oxidizing catalyst 6.
Since the first embodiment of the present inven-tion provides the catalyzing system having the struc-ture thus far described, the primary reducing catalyst and secondary oxidizing catalyst can be easily mounted from the openings at the sides of the exhaust manifold and the case, respectively, before the exhaust manifold and the case are connected for the assembly. Unlike the prior art, the holding member is neither caught nor peeled because the two catalysts are not sequentially inserted from the common opening. In addition to the above-specified effect, according to the second embodi-ment, the portion of the exhaust manifold extended to the oxidizing catalyst performs the function of the spacer of the catalyzing system of the prior art so that the secondary air can be sufficiently distributed without providing any spacer separately.
Claims (4)
1. A catalyzing system in a primary reducing catalyst and a secondary oxidizing catalyst arrayed in tandem just downstream of an exhaust manifold, comprising:
an accommodation portion provided on the downstream of the exhaust manifold to accommodate the primary catalyst, a flange provided on the downstream edge of the exhaust manifold, a case for the secondary catalyst having a flange to be connected to the above flange, an air-permeable spacer interposed between the primary catalyst and the secondary catalyst when those catalysts are accommodated in the accommodation portion and in the case respectively and the flanges are connected to each other in order to form a space between the primary catalyst and the secondary catalyst; and a secondary air inlet provided on one of the flanges which is in communication with the space.
an accommodation portion provided on the downstream of the exhaust manifold to accommodate the primary catalyst, a flange provided on the downstream edge of the exhaust manifold, a case for the secondary catalyst having a flange to be connected to the above flange, an air-permeable spacer interposed between the primary catalyst and the secondary catalyst when those catalysts are accommodated in the accommodation portion and in the case respectively and the flanges are connected to each other in order to form a space between the primary catalyst and the secondary catalyst; and a secondary air inlet provided on one of the flanges which is in communication with the space.
2. A catalyzing system according to claim 1, wherein the spacer is formed by the extended portion from the edge of the exhaust manifold.
3. A catalyzing system according to claim 1, wherein the flange of the exhaust manifold is located on the side of the accommodation portion and the flange of the secondary catalyst is extended coaxially with the accommodation portion maintaining an annular space therebetween.
4. A catalyzing system according to claim 1, wherein the spacer has a plurality of pores to allow air flow to the secondary catalyst.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JPSHO63-83580 | 1988-06-24 | ||
| JP8358088U JPH024920U (en) | 1988-06-24 | 1988-06-24 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1333696C true CA1333696C (en) | 1994-12-27 |
Family
ID=13806435
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 603771 Expired - Fee Related CA1333696C (en) | 1988-06-24 | 1989-06-23 | Catalyzing system |
Country Status (2)
| Country | Link |
|---|---|
| JP (1) | JPH024920U (en) |
| CA (1) | CA1333696C (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP3716588B2 (en) * | 1997-12-11 | 2005-11-16 | 日産自動車株式会社 | Catalytic converter device in internal combustion engine |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5425564B2 (en) * | 1974-04-03 | 1979-08-29 |
-
1988
- 1988-06-24 JP JP8358088U patent/JPH024920U/ja active Pending
-
1989
- 1989-06-23 CA CA 603771 patent/CA1333696C/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPH024920U (en) | 1990-01-12 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKLA | Lapsed |