Catalytic converter

• US 4,235,843 A
• Filed: 08/10/1979
• Issued: 11/25/1980
• Est. Priority Date: 08/14/1978
• Status: Expired due to Term

• Current Assignee: Toyo Kogyo Co Ltd (Mazda Motor Corporation)
• Original Assignee: Toyo Kogyo Co Ltd (Mazda Motor Corporation)
• Inventors: Okimoto, Haruo, Tadokoro, Tomoo, Yoshii, Shinichi
• Primary Examiner(s): Cuchlinski, Jr., William A.
• Application Number:
  US06/065,744
• Time in Patent Office: 473 Days
• Field of Search: 422/170-172, 422/119, 60/299, 60/307, 55/DIG. 30
• US Class Current: 422/119
• CPC Class Codes: B01D 53/9472 in different zones
• CPC Class Codes: F01N 2330/08 Granular material
• CPC Class Codes: F01N 2450/20 by mechanical joints, e.g. by deforming housing, tube, baffle plate or parts thereof
• CPC Class Codes: F01N 2450/22 by welding or brazing
• CPC Class Codes: F01N 2470/08 Gas passages being formed between the walls of an outer shell and an inner chamber
• CPC Class Codes: F01N 3/2846 specially adapted for granular supports, e.g. pellets
• CPC Class Codes: F01N 3/34 using air conduits or jet air pumps, e.g. near the engine exhaust port
• CPC Class Codes: Y02A 50/20 Air quality improvement or preservation, e.g. vehicle emission control or emission reduction by using catalytic converters
• CPC Class Codes: Y02T 10/12 Improving ICE efficiencies

Abstract

A catalytic converter for removing noxious pollutants from exhaust gases particularly emitted from an automobile internal combustion engine comprises a housing having a pair of longitudinally spaced catalyst containers mounted therein between inlet and outlet. The housing is constituted by a top housing shell and a bottom housing shell positioned one above the other with respective flanges of the top and bottom housing shells joined together. Each of the catalyst containers is similarly constituted by an upper retainer plate and a lower retainer plate positioned one above the other with respective flanges of the upper and lower retainer plates joined together. The overlapped flanges of the upper and lower retainer plates for each catalyst container are sandwiched between the flanges of the top and bottom housing. A secondary air supply pipe is supported by the housing and projects into the intermediate chamber between the catalyst containers within the housing through the joint of the top and bottom housing shells.

Claims

1. A catalytic converter which comprises, in combination:

a generally elongated housing structure including a generally upwardly dished top housing shell having a top peripheral flange protruding outwards therefrom, and a generally downwardly dished bottom housing shell having a bottom peripheral flange protruding outwards therefrom, said top and bottom housing shells being positioned one above the other, with the top and bottom peripheral flanges connected to each other, to define a gas flow compartment therein, said top housing shell also having first and second semicylindrical recesses opposed to each other and respectively defined at the opposed portions of the top peripheral flange, said bottom housing shell also having first and second semicylindrical recesses opposed to each other and respectively defined at the opposed portions of the bottom peripheral flange, said first and second semicylindrical recesses in the top peripheral flange and said first and second semicylindrical recesses in the bottom peripheral flange being so recessed upwardly and downwardly, respectively, as to define inlet and outlet openings at the opposed ends of the housing structure when the top and bottom housing shells are assembled together to define the gas flow compartment, first and second catalyst containers housed within the gas flow compartment adjacent the inlet and outlet openings, respectively, and spaced a distance from each other in a direction longitudinally of the housing structure, each of said first and second catalyst containers being adapted to hold a bed of catalyst material therein for removal of noxious pollutants from exhaust gases which may be introduced into the converter through the inlet opening and discharged therefrom through the outlet opening, said first and second catalyst containers so housed within the gas flow compartment dividing said gas flow compartment into an upstream chamber positioned between the inlet opening and the first catalyst container, a substantially intermediate chamber positioned between the first and second catalyst containers and a downstream chamber positioned between the second catalyst container and the outlet opening, each of said first and second catalyst containers being constituted by an upper retainer plate and a lower retainer plate, said upper retainer plate including a perforated top wall having a plurality of apertures defined therein, first and second side walls opposed to each other and having respective flanges remote from the perforated top wall of the upper retainer plate, and first and second end walls opposed to each other and having respective flanges remote from the perforated top wall of the upper retainer plate, said lower retainer plate including a perforated top wall having a plurality of apertures defined therein, first and second side walls opposed to each other and having respective flanges remote from the perforated top wall of the lower retainer plate, and first and second end walls opposed to each other and having respective flanges remote from the perforated top wall of the lower retainer plate, said upper and lower retainer plates for each of the first and second catalyst containers being positioned one above the other with the flanges of said side and end walls of the respective upper and lower retainer plates, thereby defining a catalyst retainer space for the accommodation of the corresponding catalyst bed, said upstream chamber being communicated to the intermediate chamber through the catalyst bed within the first catalyst container and said downstream chamber being also communicated to the intermediate chamber through the catalyst bed within the second catalyst container, the overlapped opposed side walls of the respective upper and lower retainer plates for each of the first and second catalyst containers being sandwiched between other respective portions of the top and bottom peripheral flanges than said opposed portions where the semicylindrical recesses are defined, respectively, inlet and outlet tubular members respectively inserted in the inlet and outlet openings, the first end walls of the upper and lower retainer plates of the first catalyst container being sandwiched in position between the outer peripheral surface of the inlet tubular member and that portion of the flange of the bottom housing shell where the first semicylindrical recess is defined whereas the second end walls of the upper and lower retainer plates of the second catalyst container are sandwiched in position between the outer peripheral surface of the outlet tubular member and that portion of the flange of the top housing shell where the second semicylindrical recess is defined, the second end walls of the upper and lower retainer plates of the first catalyst container being secured to the top housing shell whereas the first end walls of the upper and lower retainer plates of the second catalyst container are secured to the bottom housing shell, and a substantially elongated nozzle means protruding through the joint between the flanges of the top and bottom housing shells into the intermediate chamber in a direction generally perpendicular to the longitudinal axis of the housing structure, said nozzle means being utilized to inject a secondary air therethrough into the intermediate chamber to mix with the exhaust gases flowing therein.

2. A catalytic converter as claimed in claim 1, wherein a portion of the flange of at least one of the top and bottom housing shells, which is located on one side of the housing structure, is formed with a first concave portion complemental in cross sectional shape to the nozzle means, said nozzle means sealingly extending through said concave portion and secured to that portion of the flange of the housing shell on one side of the housing structure.

3. A catalyst converter as claimed in claim 1, wherein that portion of the flange of the bottom housing shell where the first semicylindrical recess is defined and the first end wall of the upper retainer plate of the first catalyst container are welded to the outer peripheral surface of the inlet tubular member while the first end wall of the lower retainer plate of the first catalyst container is loosely sandwiched between the first end wall of the upper retainer plate of the first catalyst container and that portion of the flange of the bottom housing shell where the first semicylindrical recess is defined.

4. A catalyst converter as claimed in claim 1, wherein that portion of the flange of the bottom housing shell where the first semicylindrical recess is defined is welded to the outer peripheral surface of the inlet tubular member while the first end walls of the upper and lower retainer plates of the first catalyst container is loosely sandwiched between the inlet tubular member and that portion of the flange jof the bottom housing shell where the first semicylindrical recess is defined.

5. A catalytic converter as claimed in claim 1, further comprising at least one supporting stud for each of the first and second catalyst containers, said supporting stud extending between the top and bottom housing shells through the corresponding catalyst container to keep the upper and lower retainer plates of said corresponding catalyst container in constantly spaced relation to each other.

6. A catalytic converter as claimed in claim 5, wherein said supporting stud has a pair of opposed end portions reduced in diameter relative to the substantially intermediate portion thereof, said intermediate portion of the supporting stud being positioned between the upper and lower retainer plates, the extremities of said respective end portions of the supporting stud being rigidly connected to the top and bottom housing shells, respectively.

7. A catalytic converter as claimed in claim 6, further comprising a pair of spacer members for each supporting stud, said spacer members being mounted on the reduced end portions of the supporting stud and positioned between the top housing shell and the upper retainer plate and between the bottom housing shell and the lower retainer plate, respectively.

8. A catalytic converter as claimed in claim 1, further comprising a substantially elongated temperature sensor projecting into the intermediate chamber in axial alignment with the nozzle means for detecting the temperature inside the converter.