CA2009396C - Catalytic converter with one piece housing - Google Patents
Catalytic converter with one piece housingInfo
- Publication number
- CA2009396C CA2009396C CA 2009396 CA2009396A CA2009396C CA 2009396 C CA2009396 C CA 2009396C CA 2009396 CA2009396 CA 2009396 CA 2009396 A CA2009396 A CA 2009396A CA 2009396 C CA2009396 C CA 2009396C
- Authority
- CA
- Canada
- Prior art keywords
- housing
- tube
- catalyst
- converter
- substrate
- 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
- 230000003197 catalytic effect Effects 0.000 title claims abstract description 15
- 239000003054 catalyst Substances 0.000 claims abstract description 43
- 229910052751 metal Inorganic materials 0.000 claims abstract description 20
- 239000002184 metal Substances 0.000 claims abstract description 20
- 239000000758 substrate Substances 0.000 claims description 56
- 238000007373 indentation Methods 0.000 claims description 30
- 230000002093 peripheral effect Effects 0.000 claims description 10
- 238000003825 pressing Methods 0.000 claims description 8
- 238000004519 manufacturing process Methods 0.000 claims description 7
- 239000000919 ceramic Substances 0.000 claims description 5
- 238000000034 method Methods 0.000 claims description 3
- 230000003647 oxidation Effects 0.000 claims description 3
- 238000007254 oxidation reaction Methods 0.000 claims description 3
- 239000000463 material Substances 0.000 claims description 2
- 238000005096 rolling process Methods 0.000 claims 1
- 239000007789 gas Substances 0.000 description 9
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 4
- 229930195733 hydrocarbon Natural products 0.000 description 4
- 150000002430 hydrocarbons Chemical class 0.000 description 4
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 2
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 description 2
- RTZKZFJDLAIYFH-UHFFFAOYSA-N Diethyl ether Chemical compound CCOCC RTZKZFJDLAIYFH-UHFFFAOYSA-N 0.000 description 2
- GQPLMRYTRLFLPF-UHFFFAOYSA-N Nitrous Oxide Chemical class [O-][N+]#N GQPLMRYTRLFLPF-UHFFFAOYSA-N 0.000 description 2
- 229910052799 carbon Inorganic materials 0.000 description 2
- 229910002092 carbon dioxide Inorganic materials 0.000 description 2
- 239000001569 carbon dioxide Substances 0.000 description 2
- 229910002091 carbon monoxide Inorganic materials 0.000 description 2
- 238000010276 construction Methods 0.000 description 2
- 238000003780 insertion Methods 0.000 description 2
- 230000037431 insertion Effects 0.000 description 2
- -1 ~ater Chemical compound 0.000 description 1
- 230000006835 compression Effects 0.000 description 1
- 238000007906 compression Methods 0.000 description 1
- 238000002788 crimping Methods 0.000 description 1
- 230000003628 erosive effect Effects 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
- 230000013011 mating Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- 235000012771 pancakes Nutrition 0.000 description 1
- 238000005192 partition Methods 0.000 description 1
- 229910052902 vermiculite Inorganic materials 0.000 description 1
- 235000019354 vermiculite Nutrition 0.000 description 1
- 239000010455 vermiculite Substances 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
- 238000003466 welding Methods 0.000 description 1
Landscapes
- Exhaust Gas After Treatment (AREA)
- Exhaust Silencers (AREA)
Abstract
A catalytic converter has a one piece housing and is made by inserting catalyst elements into opposite open ends of a sheet metal tube until their support mats abut against preformed annular ribs after which annular ribs are formed in the tube to engage the other ends of the support mats and the ends of the tube are pinched together to form sealed end closures with gas flow passages in them.
Description
2~93g6 Catalytic Converter with One Piece ~ousing This invention relates to catalytic converters useful in m~tor vehicle exhaust gas systems and, in particular, to converters of the type having one or more ceramic monoliths or substrates mounted inside of a sheet metal housing, the substrates containing a multiplicity of longitudinal straight-through-flow exhaust gas passages that are coated with catalyst.
.
Typically, the metal housings for commercially acceptable converters of the type just described are of the so-called "pancake" or "clamshell" design; i.e., they comprise stamped upper and lo~er shells, which are substantially identical to each other, and which have mating, peripheral, side flanges that are welded together to .lie in a plane containing the longitudinal axis of the housing. They are shaped to form an internal chamber in which the substrates are mounted. Another commercial form of catalytic converter housing comprises a tube with separate end cones welded at each end; i.e., a three-piece housing.
It is the purpose of the present invention to provide a converter of the type described above, and the method of making it, which has a one-piece, metal, tubular housing instead of a tw~-piece "clamshell"
housing or the three-piece end cone type housing. A converter according to the invention performs at least as well as one having a prior type housing but has a construction that is inherently more economical to produce and one that can be mass-manufactured in the large volumes required to supply original equipment converters directly to _ !
- 2~09396 manufacturers of automobiles and trucks for factory installation in exhaust systems.
The present invention involves the use of an open-ended metal tube that has a first annular indentation formed in it to serve as a locating and holding rib. The catalyst coated ceramic substrate with a circumferential support mat is placed inside of the tube so that the innermost end edge of the support mat abuts the first annular rib.
Thereafter, a second annular indentation is formed in the metal tube at a location in which it abuts the other or outermost end edge of the support mat so that it also serves as a locating and holding rib for the substrate. After the substrate is positioned in thé tube, the open ends of the tube are pinched together by radial deormation to close the ends of the tube and form an inlet aperture in one end and an outlet aperture in the other end. In a preferred embodiment, the above procedure is used to position two substrates in the housinq, one being coated with three way catalysts to convert nitrous oxides, carbon monoxide, and hydrocarbons and the other beinq coated with oxidation catalysts to convert carbon monoxide and hydrocarbons.
Other features and advantages of the invention will appear in the detailed description.
Description of the Drawings Fiqure 1 is a perspective view of a catalytic converter according to the invention;
Figure 2 is an end view of a round tube from which the housing of Figure 1 may be fabricated;
2~0Q939G
Figure 3 is an enlarged section along the line 3-3 of Figure 2 sho~ing that the tube is of uniform diameter and thickness and has smooth walls;
Figure 4 is an end view of the tube of Figure 1 after it has been shaped into an oval with ribs.
Figure 5 is an enlarged section along the line 5-5 of Figure 4;
Figure 6 is a view similar to Figure 5 but shows two catalyst coated substrates wrapped with support mats inserted into the tube to seat against the ribs;
Figure 7 is a view similar to Fi~lre 6 but shows the second set of ribs holding the substrates in place; and Figure 8 is a view similar to Figure 7 (and corresponds to a section along plane 8-8 of Figure 1) and shows the sec~nd set of ribs along with the pinched down ends of the tu~e from which the converter housing is formed.
Detailed Description of a Preferred Embodiment In accordance with the invention, a catalytic converter 1 has a one piece, tubular metal housing 3 with an inlet 5 at one end and an outlet 7 at the other end. A first substrate 9 with circumferentially surrounding and narrower band-like support mat 11 is positioned inside of the housing 3 adjacent the inlet 5 end of the housing. A second substrate 13 with its circumferentially surrounding and narrower band-like support mat 15 is positioned inside of the housing 3 adjacent the outlet 7 end of the housing and is longitudinally separated from substrate 9. The substrates 9 and 13 are of the same but smaller cross section as the housing 3 and their outer peripheral surfaces are 20Q~396 uniformly spaced radially in~ardly from tlle inner wall of the housing.
The ends of the support mats are located inwardly of the end faces of the substrates as shown in the drawings. The support mats are composed of a gas imyervious, vermiculite based material, available on the open market, which is intumescent and expands substantially upon heating.
The substrates 9 and 13 subdivide the space inside of the housing 3 into three chambers; i.e., an inlet chamber 17 bet~een the inlet 5 and the inlet side of the substrate 9, a central chamber 19 between the outlet side of substrate 9 and the inlet side of substrate 13, and an outlet chamber 21 between the outlet side of substrate 13 and the outlet 7. Though not illustrated, it is to be understood that each substrate has a great number of longitudinally extending straight-through flow gas passages and that these are coated with appropriate ea~a~ysts. Thus, gas can flow straight through the converter 1 from inlet passage 5 to outlet passage 7, being treated as it flows through the longitudinal passages in the catalyst elements defined by substrates 9 and 13. The substrate 9 may contain three-way catalysts to convert nitrous oxides, carbon n~noxide, and hydrocarbons to nitrogen, ~ater, and carbon dioxide. The substrate 13 may contain an oxidation catalyst and secondary air may be supplied to chamber 19 to convert carbon m~noxide and hydrocarbons to water and carbon dioxide. A secondary air inlet and conduit l9A is illustrated diagrammatically in Fi~ure 8.
In further accord with the invention, a substrate locating and holdiny means is provided in the form of a first and inner set of annular, rib-forming indentations 23 and 25 in the wall of the tubular housing 3 located adjacent opposite ends of central chamber 19. A
-~0093S6 second and outer set of similar annular rib-forming indentations 27 and 29 is also formed in housing 3 to cooperate, respectively, with ribs 23 and 25 in locating and holding the substrates 11 and 13, respectively, in place in the housing.
Preferably, the depth of the indentations is about half the thickness of the mats 11 and 15. This enables them to protect the ends of the non-metallic support mats to some degree from gas flowing in the converter and still allows some relative movement of the substrate with respect to the housing (due to resiliency in the mats) without contact with the substrate. The indentation 27 is spaced from the indentation 23 by a longitudinal distance that is about the same as or slightly less than the width of the mat 11 at the time of its insertion into the housing 3. The indentation 29 is longitudinally ~sp~ced from hte indentation 25 by a distance that is about the same as or slightly less than the width of the mat 15 at the time of its insertion into the housing 3.
As seen in Figures 1 and 8, at each end of the housing opposite sides are in engagement to close the ends of the housing. At the inlet end, the top and bottom of the tubular housing 3 are radially deformed or squeezed together to produce the inlet passage 5 and the pinched-together corners 31 and 33 on opposite sides of the passage 5.
The pinched corners 31 and 35 comprise a double thickness of metal and the two layers are preferably welded together to form and serve as closure means that seals the inlet end of the housing except for the formed passage 5. Similarly, at the outlet end the top and bottom of the tubular housing 3 are radially deformed to produce the outlet passage 7 and the pinched-together corners 35 and 37 on opposite sides of the passage 7. The two metal layers of the corners 35 and 37 are preferably welded together whereby they serve as closure means to seal the outlet end, of the housing except for the passage 7. Pinched-in end closures of this general type in exhaust gas mufflers are shown and described in U.S. patent 3,648,803 of March 14, 1972 of Robert A. Heath and Ronald J. Martoia owned by the assignee of the present invention.
In general, a converter embodying the invention may be of round cross section such as shown in Figure 1 or of other cross sections, such as oval. The oval cross section illustrated herein is ordinarily preferred for automotive exhaust systems because the converter can be shaped to occupy minimum vertical space beneath the vehicle. In making the converter 1 of this invention it is convenient ~ start with commercially available round metal tubing and radially compress it from opposite sides to form the oval shape of Figure 4. Preferably, this is done by means of dies ~hich simultaneously form the annular indentations 23 and 25 to produce the shape shown in Fkgure 5. The substrates 9 and 13 with their peripheral support mats 11 and 15 are of the same outer oval size as the inside of the ovalized housing 3 and they are stuffed into the opposite open ends of the housing until the inner end of mat 11 is pressed against indentation 23 and the inner end of mat 15 is pressed against indentation 25 as shown in Figure 6.
The next steps are to form the annular indentations 27 and 29 and the inlet end closure 45 (comprising corners 31 and 33 and inlet passage 5) and the outlet end closure 47 (comprising corners 35 and 37 and outlet passage 7~. While the indentations 27 and 29 can be rolled into 20~939 ~
the housing 3 before the end closures are formed, as shown in Figure 7, it is possible to simultaneously press-form the indentations 27 and/or 29 and the end closures. This eliminates one operation and also helps to protect the adjacent ends of the frangible substrates 9 and 13 from damage during crimping of the end closures. It appears that the ribs on the punch (not shown) for simultaneously pressing the indentations 23 and/or 25 and the end closures (or other parts of such punch) furnish radial support to the ends of the housing adjacent the substrate during pinch down of the housing ends and take some of the load to help avoid crushing of the adjacent corners of the substrate.
The indentations 27 and 29 can be rolled in together or separately.
Alternatively, the indentations 27 and 29 to~ether with respective end closures 45 and 47 can be formed one end at a ,,~irne or both simultaneously. Since the converter is symmetrical, the same tooling can be used to form one end at a time; it being necessary only to simply reverse the housing end for end to perform the desired operation.
The engagement of each combined substrate and mat with the housing is such as to permit them to be longitudinally stuffed into the housing 3. When used in an exhaust system the mats 11 and 15 are heated and expand to such a degree that they tightly hold the substrates in place without the need for mechanical assistance, ribs, or partitions.
Ordinarily, the peripheral outer surface of the substrates that engages the mat is rough so that the mat does not tend to slip longitudinally along the substrate even before heat expansion radially compresses it against the outer substrate surface. However, the inner wall of housing 3 is smooth and there is a possibility of slippage between the outer .
2(~0~3~6 surface of the mat and the housing until heat is applied to and the mat expands. The pre-heat condition exists during the period between manufacture and actual use on a vehicle. During this period much handling of the converter occurs. Slippage at the interface between the mat and housing is avoided, however, by the holding means provided by rib sets 23, 27 and 25, 29. During actual use of the converter, these indentations or ribs reduce the end areas of the mats that are exposed to flowing gas and therefore tend to protect the mats from erosion. At the same time they are located radially outwardly of the substrates so that the full cross sectional areas of the substrates are available for gas flow and treatment. Ribs have been used heretofore in converters with "clamshell" housings in conjunction with metal mesh type substrate supports to help hold the supports in place during a~ct~l use of the converter. In this invention, radial compression in the support mats as a result of heat expansion holds them in place during actual use of the converter.
The converter illustrated contains two separate catalyst elements.
One of the elements could be omitted along with the appropriate pair of locating and holding ribs so that the converter would contain just one catalyst member but still embody the one piece housinc3 and rib construction described herein.
While the converter is shown as symmetrical about a longitudinal axis through the center lines of passages 5 and 7, it will be recognized tllat the structure and method described would also enable one or both passages to be transversely offset from the longitudinal axis. If ~0~93~6 desired, a known type of heat shield may be attached to the converter housing 3 by welding or otherwise.
Modifications may be made in the specific features shown and described without departing from the spirit and scope of the invention.
.
Typically, the metal housings for commercially acceptable converters of the type just described are of the so-called "pancake" or "clamshell" design; i.e., they comprise stamped upper and lo~er shells, which are substantially identical to each other, and which have mating, peripheral, side flanges that are welded together to .lie in a plane containing the longitudinal axis of the housing. They are shaped to form an internal chamber in which the substrates are mounted. Another commercial form of catalytic converter housing comprises a tube with separate end cones welded at each end; i.e., a three-piece housing.
It is the purpose of the present invention to provide a converter of the type described above, and the method of making it, which has a one-piece, metal, tubular housing instead of a tw~-piece "clamshell"
housing or the three-piece end cone type housing. A converter according to the invention performs at least as well as one having a prior type housing but has a construction that is inherently more economical to produce and one that can be mass-manufactured in the large volumes required to supply original equipment converters directly to _ !
- 2~09396 manufacturers of automobiles and trucks for factory installation in exhaust systems.
The present invention involves the use of an open-ended metal tube that has a first annular indentation formed in it to serve as a locating and holding rib. The catalyst coated ceramic substrate with a circumferential support mat is placed inside of the tube so that the innermost end edge of the support mat abuts the first annular rib.
Thereafter, a second annular indentation is formed in the metal tube at a location in which it abuts the other or outermost end edge of the support mat so that it also serves as a locating and holding rib for the substrate. After the substrate is positioned in thé tube, the open ends of the tube are pinched together by radial deormation to close the ends of the tube and form an inlet aperture in one end and an outlet aperture in the other end. In a preferred embodiment, the above procedure is used to position two substrates in the housinq, one being coated with three way catalysts to convert nitrous oxides, carbon monoxide, and hydrocarbons and the other beinq coated with oxidation catalysts to convert carbon monoxide and hydrocarbons.
Other features and advantages of the invention will appear in the detailed description.
Description of the Drawings Fiqure 1 is a perspective view of a catalytic converter according to the invention;
Figure 2 is an end view of a round tube from which the housing of Figure 1 may be fabricated;
2~0Q939G
Figure 3 is an enlarged section along the line 3-3 of Figure 2 sho~ing that the tube is of uniform diameter and thickness and has smooth walls;
Figure 4 is an end view of the tube of Figure 1 after it has been shaped into an oval with ribs.
Figure 5 is an enlarged section along the line 5-5 of Figure 4;
Figure 6 is a view similar to Figure 5 but shows two catalyst coated substrates wrapped with support mats inserted into the tube to seat against the ribs;
Figure 7 is a view similar to Fi~lre 6 but shows the second set of ribs holding the substrates in place; and Figure 8 is a view similar to Figure 7 (and corresponds to a section along plane 8-8 of Figure 1) and shows the sec~nd set of ribs along with the pinched down ends of the tu~e from which the converter housing is formed.
Detailed Description of a Preferred Embodiment In accordance with the invention, a catalytic converter 1 has a one piece, tubular metal housing 3 with an inlet 5 at one end and an outlet 7 at the other end. A first substrate 9 with circumferentially surrounding and narrower band-like support mat 11 is positioned inside of the housing 3 adjacent the inlet 5 end of the housing. A second substrate 13 with its circumferentially surrounding and narrower band-like support mat 15 is positioned inside of the housing 3 adjacent the outlet 7 end of the housing and is longitudinally separated from substrate 9. The substrates 9 and 13 are of the same but smaller cross section as the housing 3 and their outer peripheral surfaces are 20Q~396 uniformly spaced radially in~ardly from tlle inner wall of the housing.
The ends of the support mats are located inwardly of the end faces of the substrates as shown in the drawings. The support mats are composed of a gas imyervious, vermiculite based material, available on the open market, which is intumescent and expands substantially upon heating.
The substrates 9 and 13 subdivide the space inside of the housing 3 into three chambers; i.e., an inlet chamber 17 bet~een the inlet 5 and the inlet side of the substrate 9, a central chamber 19 between the outlet side of substrate 9 and the inlet side of substrate 13, and an outlet chamber 21 between the outlet side of substrate 13 and the outlet 7. Though not illustrated, it is to be understood that each substrate has a great number of longitudinally extending straight-through flow gas passages and that these are coated with appropriate ea~a~ysts. Thus, gas can flow straight through the converter 1 from inlet passage 5 to outlet passage 7, being treated as it flows through the longitudinal passages in the catalyst elements defined by substrates 9 and 13. The substrate 9 may contain three-way catalysts to convert nitrous oxides, carbon n~noxide, and hydrocarbons to nitrogen, ~ater, and carbon dioxide. The substrate 13 may contain an oxidation catalyst and secondary air may be supplied to chamber 19 to convert carbon m~noxide and hydrocarbons to water and carbon dioxide. A secondary air inlet and conduit l9A is illustrated diagrammatically in Fi~ure 8.
In further accord with the invention, a substrate locating and holdiny means is provided in the form of a first and inner set of annular, rib-forming indentations 23 and 25 in the wall of the tubular housing 3 located adjacent opposite ends of central chamber 19. A
-~0093S6 second and outer set of similar annular rib-forming indentations 27 and 29 is also formed in housing 3 to cooperate, respectively, with ribs 23 and 25 in locating and holding the substrates 11 and 13, respectively, in place in the housing.
Preferably, the depth of the indentations is about half the thickness of the mats 11 and 15. This enables them to protect the ends of the non-metallic support mats to some degree from gas flowing in the converter and still allows some relative movement of the substrate with respect to the housing (due to resiliency in the mats) without contact with the substrate. The indentation 27 is spaced from the indentation 23 by a longitudinal distance that is about the same as or slightly less than the width of the mat 11 at the time of its insertion into the housing 3. The indentation 29 is longitudinally ~sp~ced from hte indentation 25 by a distance that is about the same as or slightly less than the width of the mat 15 at the time of its insertion into the housing 3.
As seen in Figures 1 and 8, at each end of the housing opposite sides are in engagement to close the ends of the housing. At the inlet end, the top and bottom of the tubular housing 3 are radially deformed or squeezed together to produce the inlet passage 5 and the pinched-together corners 31 and 33 on opposite sides of the passage 5.
The pinched corners 31 and 35 comprise a double thickness of metal and the two layers are preferably welded together to form and serve as closure means that seals the inlet end of the housing except for the formed passage 5. Similarly, at the outlet end the top and bottom of the tubular housing 3 are radially deformed to produce the outlet passage 7 and the pinched-together corners 35 and 37 on opposite sides of the passage 7. The two metal layers of the corners 35 and 37 are preferably welded together whereby they serve as closure means to seal the outlet end, of the housing except for the passage 7. Pinched-in end closures of this general type in exhaust gas mufflers are shown and described in U.S. patent 3,648,803 of March 14, 1972 of Robert A. Heath and Ronald J. Martoia owned by the assignee of the present invention.
In general, a converter embodying the invention may be of round cross section such as shown in Figure 1 or of other cross sections, such as oval. The oval cross section illustrated herein is ordinarily preferred for automotive exhaust systems because the converter can be shaped to occupy minimum vertical space beneath the vehicle. In making the converter 1 of this invention it is convenient ~ start with commercially available round metal tubing and radially compress it from opposite sides to form the oval shape of Figure 4. Preferably, this is done by means of dies ~hich simultaneously form the annular indentations 23 and 25 to produce the shape shown in Fkgure 5. The substrates 9 and 13 with their peripheral support mats 11 and 15 are of the same outer oval size as the inside of the ovalized housing 3 and they are stuffed into the opposite open ends of the housing until the inner end of mat 11 is pressed against indentation 23 and the inner end of mat 15 is pressed against indentation 25 as shown in Figure 6.
The next steps are to form the annular indentations 27 and 29 and the inlet end closure 45 (comprising corners 31 and 33 and inlet passage 5) and the outlet end closure 47 (comprising corners 35 and 37 and outlet passage 7~. While the indentations 27 and 29 can be rolled into 20~939 ~
the housing 3 before the end closures are formed, as shown in Figure 7, it is possible to simultaneously press-form the indentations 27 and/or 29 and the end closures. This eliminates one operation and also helps to protect the adjacent ends of the frangible substrates 9 and 13 from damage during crimping of the end closures. It appears that the ribs on the punch (not shown) for simultaneously pressing the indentations 23 and/or 25 and the end closures (or other parts of such punch) furnish radial support to the ends of the housing adjacent the substrate during pinch down of the housing ends and take some of the load to help avoid crushing of the adjacent corners of the substrate.
The indentations 27 and 29 can be rolled in together or separately.
Alternatively, the indentations 27 and 29 to~ether with respective end closures 45 and 47 can be formed one end at a ,,~irne or both simultaneously. Since the converter is symmetrical, the same tooling can be used to form one end at a time; it being necessary only to simply reverse the housing end for end to perform the desired operation.
The engagement of each combined substrate and mat with the housing is such as to permit them to be longitudinally stuffed into the housing 3. When used in an exhaust system the mats 11 and 15 are heated and expand to such a degree that they tightly hold the substrates in place without the need for mechanical assistance, ribs, or partitions.
Ordinarily, the peripheral outer surface of the substrates that engages the mat is rough so that the mat does not tend to slip longitudinally along the substrate even before heat expansion radially compresses it against the outer substrate surface. However, the inner wall of housing 3 is smooth and there is a possibility of slippage between the outer .
2(~0~3~6 surface of the mat and the housing until heat is applied to and the mat expands. The pre-heat condition exists during the period between manufacture and actual use on a vehicle. During this period much handling of the converter occurs. Slippage at the interface between the mat and housing is avoided, however, by the holding means provided by rib sets 23, 27 and 25, 29. During actual use of the converter, these indentations or ribs reduce the end areas of the mats that are exposed to flowing gas and therefore tend to protect the mats from erosion. At the same time they are located radially outwardly of the substrates so that the full cross sectional areas of the substrates are available for gas flow and treatment. Ribs have been used heretofore in converters with "clamshell" housings in conjunction with metal mesh type substrate supports to help hold the supports in place during a~ct~l use of the converter. In this invention, radial compression in the support mats as a result of heat expansion holds them in place during actual use of the converter.
The converter illustrated contains two separate catalyst elements.
One of the elements could be omitted along with the appropriate pair of locating and holding ribs so that the converter would contain just one catalyst member but still embody the one piece housinc3 and rib construction described herein.
While the converter is shown as symmetrical about a longitudinal axis through the center lines of passages 5 and 7, it will be recognized tllat the structure and method described would also enable one or both passages to be transversely offset from the longitudinal axis. If ~0~93~6 desired, a known type of heat shield may be attached to the converter housing 3 by welding or otherwise.
Modifications may be made in the specific features shown and described without departing from the spirit and scope of the invention.
Claims (20)
1. A catalytic converter of the type used in the exhaust systems of motor vehicles comprising a one piece sheet metal housing of elongated tubular shape and having a longitudinal axis and opposite ends extending transversely to said longitudinal axis, one of said ends being the gas inlet end for the converter and the other of said ends being the gas outlet end for the converter, opposite sides of said housing at said inlet end being in engagement to form an inlet end closure for the inlet end of the housing, said inlet end closure having a gas inlet passage for gas to flow into the housing, opposite sides of said housing at said outlet end being in engagement to form an outlet end closure for the outlet end of the housing, said outlet end closure having a gas outlet passage for gas to flow out of the housing, said end closures being formed by material of said sheet metal housing and serving to seal the opposite ends of the tubular housing except for said gas inlet and gas outlet passages, a gas treatment catalyst means in the housing in the path of gas flowing from the gas inlet passage to the gas outlet passage; and longitudinally separated indentations formed in the said metal housing and engaging opposite sides of said catalyst means to hold and locate said catalyst means in substantially fixed longitudinal position in the housing.
2. A catalytic converter as set forth in claim 1, wherein said catalyst means comprises a ceramic monolith substrate having longitudinal gas flow passages coated with catalyst, said substrate having an outer peripheral surface of the same shape as the inside of the tubular housing but spaced inwardly from the housing and an annular intumescent support band having an inside surface extending around and engaging said outer peripheral surface of the substrate and an outside surface engaging the inside of the tubular housing.
3. A converter as set forth in claim 2, wherein said support band is the only support connection between the substrate and the housing, said means to hold and locate said catalyst means being formed in said tubular housing for engagement with said support band to locate the longitudinal position of the substrate in the housing and hold the substrate in said longitudinal position.
4. A converter as set forth in claim 2, wherein said support band is narrower than the length of the substrate and said indentations include a transverse annular rib engaging the innermost end of the support band.
5. A converter as set forth in claim 4, wherein said annular rib has a depth that is substantially one-half the thickness of the support band.
6. A converter as set forth in claim 2, wherein said longitudinally separated indentations in said housing are at opposite longitudinal ends of the support band.
7. A converter as set forth in claim 6, wherein said indentations comprise transverse annular ribs.
8. A converter as set forth in claim 7, wherein said annular ribs each have depths that are substantially one-half the thickness of the support band whereby they also provide protection to the ends of the support band but are out of contact with the substrate and allow limited relative movement in a transverse direction between the housing and the substrate.
9. A converter as set forth in claim 1, wherein said housing and catalyst means are oval in cross section.
10. A converter as set forth in claim 1, wherein said catalyst means comprises a first catalyst member located in the inlet end of said housing and a second catalyst member located in the outlet end of the housing, said first and second catalyst members being longitudinally separated from each other and the space in the housing between the first and second catalyst members forming a central chamber in the housing.
11. A converter as set forth in claim 10, including means for injecting secondary air into said central chamber, said second catalyst member comprising an oxidation catalyst.
12. A converter as set forth in claim 10, wherein said first catalyst member comprises a first ceramic monolith substrate having longitudinal gas flow passages coated with catalyst and an outer peripheral surface, said first catalyst member including a first annular intumescent support mat having an inside surface extending around and engaging the outer peripheral surface of the first substrate and an outside surface engaging the inside of the tubular housing, said second catalyst member comprising a second ceramic monolith substrate having longitudinal gas flow passages coated with catalyst and an outer peripheral surface, said second catalyst member including a second annular intumescent support mat having an inside surface extending around and engaging the outer peripheral surface of the second substrate and an outside surface engaging the inside of the tubular housing, said longitudinally separated indentations including a first pair of indentations for engagement with said first support mat to locate the longitudinal positions of the first substrate in the housing and hold the first substrate in such longitudinal position, and a second pair of indentations formed in said tubular housing for engagement with said second support mat to locate the longitudinal position of the second substrate in the housing and hold the second substrate in such longitudinal position.
13. A converter as set forth in claim 12, wherein said first pair of indentations includes a first inner transverse annular rib formed in the tubular housing and engaging the inner end of the first support mat, said second pair of indentations including a first inner transverse annular rib formed in the tubular housing and engaging the inner end of the second support mat.
14. A converter as set forth in claim 13, wherein said first pair of indentations includes a second inner transverse annular rib formed in the tubular housing and engaging the outer end of the first support mat, said second pair of indentations including a second inner transverse annular rib formed in the tubular housing and engaging the outer end of the second support mat.
15. The method of working a catalytic converter which comprises forming a first transverse rib in the wall of an open-ended sheet metal tube, inserting a monolith type catalyst member into the open end of the tube and moving it longitudinally relative to the tube until its inner end abuts the first transverse rib, thereafter forming a second transverse rib in the wall of the tube so that it is substantially in engagement with the outer end of the catalyst member to hold the catalyst member in longitudinal position wherein it abuts the first transverse rib, and closing the open end of the tube except for a gas flow passage by pressing opposite sides of the end of the tube together to form a double metal layer end closure containing a gas flow passage.
16. A method of making a catalytic converter as set forth in claim 15, comprising rolling said second transverse rib into the wall of the tube so that it is substantially annular.
17. A method of making a catalytic converter as set forth in claim 15, comprising pressing said opposite sides of the end of the tube to form said end closure and simultaneously pressing opposite sides of the tube to form said second transverse rib.
18. The method of making a catalytic converter containing a monolith type catalyst element having a support mat wrapped around its outer periphery which comprises forming a first annular rib in the wall of an elongated open-ended sheet metal tube, inserting the combined catalyst element and support mat into the open end of said tube and moving it longitudinally until the inner end of the support mat engages the first annular rib, thereafter forming a second annular rib in the wall of the tube so that it is substantially in engagement with the outer end of the support mat, and closing the open end of the tube except for a gas flow passage.
19. The method of making a catalytic converter containing a monolith type catalyst element having a support mat wrapped around its outer periphery which comprises pressing a round open-ended sheet metal tube into an oval shape and at the same time pressing a first annular oval rib in the wall of the tube, inserting the combined catalyst element and support mat into the open end of said tube and moving it longitudinally until the inner end of the support mat engages the first annular rib, thereafter forming a second annular rib in the wall of the tube so that it is substantially in engagement with the outer end of the support mat, and closing the open end of the tube except for a gas flow passage by pressing opposite sides of the end of the tube together to form a double metal layer end closure containing a gas flow passage.
20. The method of making a catalytic converter containing two monolith type catalyst elements each having a support mat wrapped around its outer periphery which comprises forming a pair of first annular ribs in a central position of an elongated sheet metal tube that is open at opposite ends, inserting one of the combined catalyst elements and support mats into one open end of said tube and moving it longitudinally until the inner end of its support mat engages one of said first annular ribs, inserting the other of the combined catalyst elements and support mats into the other open end of said tube and moving it longitudinally until the inner end of its support mat engages the other of said first annular ribs, thereafter forming a pair of second annular ribs in said tube with one of said second ribs being located to be substantially in engagement with the outer end of said one of said combined catalyst elements and support mats and the other of said second ribs being located to be substantially in engagement with the outer end of said other of said combined catalyst elements and support mats, and pressing opposite sides of the ends of the tube together to form an end closure at one end containing an inlet gas flow passage and an end closure at the other end containing an outlet gas flow passage.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US30691589A | 1989-02-06 | 1989-02-06 | |
| US306,915 | 1989-02-06 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CA2009396A1 CA2009396A1 (en) | 1990-08-06 |
| CA2009396C true CA2009396C (en) | 1995-03-28 |
Family
ID=23187447
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2009396 Expired - Fee Related CA2009396C (en) | 1989-02-06 | 1990-02-06 | Catalytic converter with one piece housing |
Country Status (3)
| Country | Link |
|---|---|
| JP (1) | JP2679857B2 (en) |
| AU (2) | AU632788B2 (en) |
| CA (1) | CA2009396C (en) |
Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP3585064B2 (en) * | 1995-10-12 | 2004-11-04 | トヨタ自動車株式会社 | Monolithic catalytic converter and method of manufacturing the same |
| JP4576025B2 (en) * | 2000-06-01 | 2010-11-04 | 三恵技研工業株式会社 | Method for manufacturing catalytic converter |
| EP1188910B1 (en) | 2000-09-18 | 2004-06-16 | Toyota Jidosha Kabushiki Kaisha | Method for Production of an Exhaust Gas Purifying Catalyst |
| JP2002161726A (en) * | 2000-11-29 | 2002-06-07 | Ibiden Co Ltd | Exhaust gas purification device and method for manufacturing the same, and housing structure for ceramic honeycomb structure |
| JP4506931B2 (en) * | 2003-06-03 | 2010-07-21 | トヨタ自動車株式会社 | Reduced tube forming apparatus, reduced tube forming method, and catalytic converter manufactured using the same |
| WO2020213108A1 (en) * | 2019-04-17 | 2020-10-22 | 江崎工業株式会社 | Method of arranging functional member |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| NZ203943A (en) * | 1983-04-19 | 1986-06-11 | R M B Sanderson | Silencer having an outer shell free of lingitudinal creasing and with baffle to body joints free of welding |
| FI74522C (en) * | 1986-04-29 | 1988-02-08 | Kemira Oy | FOERFARANDE FOER INKAPSLING AV EN KATALYTCELL AVSEDD FOER RENING AV AVGAS. |
| US5216809A (en) * | 1990-07-02 | 1993-06-08 | Tennessee Gas Pipeline Company | Acoustic muffler with one-piece housing |
-
1990
- 1990-02-06 CA CA 2009396 patent/CA2009396C/en not_active Expired - Fee Related
- 1990-02-06 JP JP2699190A patent/JP2679857B2/en not_active Expired - Lifetime
- 1990-02-07 AU AU49233/90A patent/AU632788B2/en not_active Ceased
-
1992
- 1992-11-27 AU AU29721/92A patent/AU652300B2/en not_active Ceased
Also Published As
| Publication number | Publication date |
|---|---|
| JP2679857B2 (en) | 1997-11-19 |
| AU2972192A (en) | 1993-02-11 |
| JPH02264110A (en) | 1990-10-26 |
| AU632788B2 (en) | 1993-01-14 |
| AU652300B2 (en) | 1994-08-18 |
| CA2009396A1 (en) | 1990-08-06 |
| AU4923390A (en) | 1990-08-09 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EEER | Examination request | ||
| MKLA | Lapsed |