Catalytic converter and substrate support with one piece housing

Claim 2

In a catalyst converter for use in a motor vehicle exhaust system, said converter including a tubular body having an inlet and outlet means for the gas flow inside the tube, a catalyst substrate having a tubular central portion positioned inside the body, and a support mat surrounding the central portion of the substrate, the improvement wherein said tubular body is one-piece and has a central, generally cylindrical, reduced diameter portion radially compressed against the mat and the mat radially compressed against the substrate to hold and locate the substrate in a substantially fixed longitudinal position in the body, said reduced diameter portion comprising first portions compressed radially inwardly by a first predetermined amount, and longitudinal second portions compressed radially inwardly from said first portions by a second predetermined amount and making line contact with the outer periphery of the mat.

Claim 3

The improvement as claimed in claim 1 wherein said first portions define rib means that are parallel to the longitudinal axis of said tubular body.

Claim 4

The improvement as claimed in claim 2 wherein each of said rib means and each of said second portions have a lateral width that is substantially equal.

Claim 5

The improvement as claimed in claim 1 wherein said mat is composed of a material that expands significantly upon heating and thereby increases the radial compression between the substrate and reduced diameter portion.

Claim 6

The improvement as claimed in claim 1 wherein said mat and said substrate extend longitudinally, said mat is composed of fibrous material, and the length of the mat is about 50-90% of the length of the substrate.

Claim 7

The improvement as claimed in claim 5 wherein the longitudinal extension of said mat is about 70% of the longitudinal extension of the substrate.

Claim 8

The improvement as claimed in claim 1 wherein the ends of said body are formed to define said gas inlet means at one end and said gas outlet means at the other end.

Claim 9

The improvement as claimed in claim 1 wherein said body and said substrate are oval in cross section.

Claim 10

The improvement as claimed in claim 1 wherein said reduced diameter portion is deformed radially inwardly relative to the support mat by an amount that is sufficient to compress the support mat to about one-half the original or free-state thickness of the mat.

Claim 11

The improvement as claimed in claim 1 wherein said mat and said reduced diameter portion comprise the only means for supporting yet allowing some relative movement of said substrate with respect to the body without contact with the substrate.

Claim 12

The improvement as claimed in claim 1 wherein said mat is composed of a heat expandable fibrous material and extends longitudinally by an amount that is about 50-90% of the length of said substrate, said mat being compressed by said central reduced diameter portion to about one-half the original or free state thickness thereof.

Claim 13

A catalytic converter for use in 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 defining a gas inlet end for the converter and the other of said ends defining a gas outlet end for the converter, opposite sides of said housing at said gas inlet end being in engagement to form an inlet end closure for said gas 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 gas outlet end being in engagement to form an outlet end closure for said gas outlet end of the housing, said outlet end closure having a gas outlet passage for gas to flow out of the housing, the sheet metal of said housing forming said inlet and outlet end closures and serving to seal the opposite ends of the tubular housing except for said gas inlet passage and said gas outlet passage, and a gas treatment catalyst means positioned in the housing for treating exhaust gases flowing from the gas inlet passage to the gas outlet passage, said gas treatment catalyst means having an outer periphery and being supported by a substantially uniformly radially reduced diameter portion of said housing, said reduced diameter portion being generally cylindrical and including a plurality of circumferentially separated longitudinal ribs which engage the outer periphery of said catalyst means to hold and locate said catalyst means in substantially fixed position in said housing.

Claim 14

A catalytic converter for use in 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 defining a gas inlet end for the converter and the other of said ends defining a gas outlet end for the converter, opposite sides of said housing at said gas inlet end being in engagement to form an inlet end closure for said gas 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 gas outlet end being in engagement to form an outlet end closure for said gas outlet end of the housing, said outlet end closure having a gas outlet passage for gas to flow out of the housing, the sheet metal of said housing forming said inlet and outlet end closures and serving to seal the opposite ends of the tubular housing except for said gas inlet passage and said gas outlet passage, and a gas treatment catalyst means positioned in the housing for treating exhaust gases flowing from the gas inlet passage to the gas outlet passage, said gas treatment catalyst means having an outer periphery and being supported by a substantially uniformly radially reduced diameter portion of said housing, said reduced diameter portion being generally cylindrical and including a plurality of circumferentially separated longitudinal ribs which engage the outer periphery of said catalyst means to hold and locate said catalyst means in substantially fixed position in said housing.

Claim 15

The improvement as claimed in claim 12 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 substantially the same shape as and corresponding in cross-section to the cross-section defining the inside surface of the tubular housing, and said outer peripheral surface being spaced inwardly from the inside surface of said housing, and an annular intumescent support band having an inside surface extending around and engaging said outer peripheral surface of said substrate and an outside surface engaging the inside surface of said tubular housing.

Claim 16

The improvement as claimed in claim 13 wherein said support band is wrapped about said substrate and both extend longitudinally, said support band being shorter than the substrate and having opposite longitudinal ends spaced inwardly from and disposed adjacent to the respective opposite longitudinal ends of said substrate.

Claim 17

The improvement as claimed in claim 14 wherein said reduced diameter portion is deformed radially inwardly by an amount that is sufficient to compress the support band to about one-half the original or free-state thickness of the band.

Claim 18

The improvement as claimed in claim 12 comprising means to resist deformation formed in a nonreduced diameter portion of said housing, surrounding said substrate during formation of said inlet and outlet end closures.

Claim 19

The improvement as claimed in claim 16 wherein said deformation resisting means comprises a pair of raised transverse annular ribs formed in said housing, with one rib near each of said housing.

Claim 20

The improvement as claimed in claim 17 wherein said catalyst means includes an inlet face, and one of said annular ribs is located at a point on said housing corresponding to the inlet face of said catalyst means.

Claim 21

The improvement as claimed in claim 18 wherein said catalyst means includes an outlet face and the other of said annular ribs is located at a point on said housing corresponding to the outlet face of said catalyst means.

Claim 22

The improvement as claimed in claim 16 wherein said deformation resisting means comprises a pair of radially projecting transverse annular ribs formed in said housing, with one rib near each of said housing.

Claim 23

The improvement as claimed in claim 20 wherein said catalyst means includes a gas inlet face and a gas outlet face, and one of said annular ribs is located at a point on said housing substantially corresponding to the inlet face of said catalyst means and the other of said annular ribs is located at a point on said housing substantially corresponding to the outlet face of said catalyst means.

Claim 24

The improvement as claimed in claim 12 wherein said housing and catalyst means are oval in cross section.

Claim 25

The improvement as claimed in claim 12 wherein said catalyst means comprises a first catalyst member located near the inlet end of said housing and a second catalyst member located near the outlet end of said housing, said first and second catalyst members being longitudinally spaced from each other and the space between the first and second catalyst members forming a central chamber in said housing.

Claim 26

The improvement as claimed in claim 23 including means for injecting secondary air into said central chamber, said second catalyst member comprising an oxidation catalyst.

Claim 27

The improvement as claimed in claim 23 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 said outer peripheral surface of said first substrate and an outside surface engaging the inside surface of said 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 said outer peripheral surface of said second substrate and an outside surface engaging the inside surface of said tubular housing, and wherein said reduced diameter portion of said tubular housing engages said first and second support mats to hold said first and second substrates in said housing.

Claim 28

The improvement as claimed in claim 12 wherein adjacent ones of said longitudinal ribs are spaced apart by a portion of said reduced diameter portion.