Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
  • F01N13/00—Exhaust or silencing apparatus characterised by constructional features ; Exhaust or silencing apparatus, or parts thereof, having pertinent characteristics not provided for in, or of interest apart from, groups F01N1/00 - F01N5/00, F01N9/00, F01N11/00
  • F01N13/08—Other arrangements or adaptations of exhaust conduits
  • F01N13/10—Other arrangements or adaptations of exhaust conduits of exhaust manifolds
  • F01N13/102—Other arrangements or adaptations of exhaust conduits of exhaust manifolds having thermal insulation
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
  • F01N13/00—Exhaust or silencing apparatus characterised by constructional features ; Exhaust or silencing apparatus, or parts thereof, having pertinent characteristics not provided for in, or of interest apart from, groups F01N1/00 - F01N5/00, F01N9/00, F01N11/00
  • F01N13/18—Construction facilitating manufacture, assembly, or disassembly
  • F01N13/1861—Construction facilitating manufacture, assembly, or disassembly the assembly using parts formed by casting or moulding
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
  • F01N2260/00—Exhaust treating devices having provisions not otherwise provided for
  • F01N2260/10—Exhaust treating devices having provisions not otherwise provided for for avoiding stress caused by expansions or contractions due to temperature variations

Definitions

• the invention relates to a double wall exhaust manifold for a motor vehicle.
• the invention more particularly relates to a double wall exhaust manifold for a motor vehicle, of the type which comprises at least one internal collector element and an external collector element, of the type in which the internal collector element comprises at least two coaxial tubes slidably fitted one inside the other and of the type in which the outer collector member is integrally molded around the inner collector member with which it determines an internal insulation cavity arranged between the inner collector member and the outer collector member.
• the document US Pat. No. 4,182,122 describes and represents a collector of the type previously described in which the internal collector element comprises at least one internal T-shaped tube whose central branch is connected to an exhaust duct. of the yoke and whose symmetrical branches, of axis intersecting with the axis of the central branch, are each slidably connected to at least one other inner tube.
• the inner connector member is separated from the outer collector member by a "T" -shaped and two-part insulator mounted with clearance between the inner collector member and the outer collector member.
• the insulation makes it possible to prevent the external collector element from being subjected to too high temperatures.
• it concentrates the heat resulting from the temperature rise of the internal collector element around the latter.
• the "T" shape of the inner tube mentioned above subjects it to high mechanical stresses when it expands due to the temperature rise of the internal collector element. This expansion, which is not controlled between the central branch and the symmetrical branches of the inner tube "T", can lead to its rupture.
• the invention overcomes these drawbacks by proposing a collector in which, on the one hand, the outer collector element is isolated from the inner collector element and, on the other hand, in which all the internal tubes of the collector internal collector element are generally elongate tubes slidably mounted in each other so as to absorb the deformations resulting from the temperature rise of the collector during its use.
• the invention proposes a collector of the type described above, characterized in that the internal collector element comprises at least a first straight rectilinear tube, a first end of which is arranged in the extension of an exhaust duct.
• a yoke of an associated heat engine and a second end of which is slidably fitted with an intermediate portion of at least one downstream tube of axis intersecting with the axis of said first upstream tube to allow the expansion of said internal element of collector during the temperature rise of the collector.
• the exhaust manifold comprises at least a second bent upstream tube whose first end is arranged in the extension of an exhaust duct of the cylinder head and whose second end, of axis intersecting with that of the first end, is slidably fitted with the end of a downstream tube,
• the exhaust manifold comprises at least two downstream tubes, one end of a downstream tube being slidably fitted with the end of the other downstream tube; the outer collector element is molded so as to trap at least a first end of an upstream tube and an end of a downstream tube,
• the external collector element comprises a bore which communicates with the internal insulation cavity to allow the evacuation of a sand core enabling the isolation cavity to be produced during the molding of said external collector element;
• the tubes of the internal collector element are made of steel.
• the invention also proposes a method for manufacturing an exhaust manifold of the type described above, characterized in that it comprises at least:
• a fourth step of casting said sand core a fifth step during which the tubes of the inner collector member and the sand core are placed in a mold having an impression of the outer collector member,
• FIG. 1 is a schematic longitudinal sectional view of a collector according to the invention.
• FIG. 2 is a schematic cross-sectional view of the collector of Figure 1.
• FIG. 3 is a schematic longitudinal sectional view of a collector according to an alternative embodiment;
• FIG. 4 is a diagrammatic cross-sectional view of the collector of FIG.
• the figures show the assembly of a double-wall exhaust manifold 10 for a motor vehicle.
• the collector 10 comprises at least one internal collector element 12 and an external collector element 14.
• the outer collector member 14 has a first flange 13 which is intended to be fixed to the yoke (not shown) of an associated engine, and a second flange 15 which is intended to be attached to an exhaust line (not shown). represented) of the vehicle.
• the internal collector element 12 comprises at least two coaxial tubes 16, 18 slidably nested one inside the other, in order to allow a determined dilation of the internal collector member 12 when it is subjected to a rise in temperature.
• the external collector element 14 is molded integrally around the internal collector element 12 with which it determines an internal insulation cavity 20 arranged between the internal collector element 12 and the external collector element 14.
• This cavity 20 allows, by a so-called "air knife” phenomenon, to isolate the external collector element 14 from the heat generated by the internal collector element 12 during the temperature rise of the collector 10, without interposing a any insulating coating between the two collector elements 12, 14 which might concentrate the heat on the internal collector element 12.
• the internal collector element 12 comprises at least a first rectilinear first pipe 22, a first end 24 of which is arranged in the extension of a duct (not shown) of exhaust of a cylinder head of an associated engine and a second end 26 is slidably engaged with an intermediate portion 28 of at least one downstream tube 16, 18 of axis "B" intersecting with the axis "A of said upstream tube 22 to allow the expansion of said internal collector element 12 during the temperature rise of the collector 10.
• the exhaust manifold 10 comprises at least a second bent upstream tube 30, a first end 32 of which is arranged in the extension of an exhaust duct (not shown) of the cylinder head and whose second end 34, secant axis "B" with T'axe "A" of the first end is slidably engaged with the end 36 of a downstream tube 18.
• the exhaust manifold 10 comprises at least two downstream tubes 16, 18, end 38 of a downstream tube 16 is slidably engaged with the end 40 of the other downstream tube 18.
• the collector 10 comprises two straight upstream first tubes 22, a second one upstream tube 30 bent, and two downstream tubes 16, 18 whose intermediate parts 28 receive the first two upstream tubes 22.
• An end 42 of the downstream tube 16 communicates with an outlet 44 of the manifold 10.
• the external collector element 14 is molded so as to trap at least a first end 24, 32 of an upstream tube 22, 30 and an end 42 of a downstream tube 16.
• This configuration obtained during the molding of the outer collector element 14 makes it possible to simply and effectively connect the element 12 of the internal collector to the element 14 of the external collector. It is then the external collector element 14 which is connected respectively to the cylinder head of the associated engine and to the rest of the exhaust system of the vehicle.
• the tubes 16, 18, 22, 30 of the inner collector member are made of steel to facilitate the trapping of their ends by the outer collector element 14.
• the external collector element 14 has a bore 46 which communicates with the internal insulation cavity 20 to allow the evacuation of a sand core enabling the insulation cavity 20 to be produced during the molding of said element. 14 external collector.
• the exhaust manifold 10 can be made very simply by a method which comprises at least:
• the invention thus makes it possible to simply and efficiently produce a "double-walled" exhaust manifold 10 in which the expansion of the tubes 16, 18, 22, 30 of the internal element 12 is absorbed by mechanical clearances in all directions, so as not to affect the resistance of said collector 10.
• the end (24) of the first straight rectilinear tube (22) and the first end (32) of the second bent up tube (30) can extend to the first face (13) of the outer collector member (14).
• the end (42) of the downstream tube (16) can extend to the second face (15) of the outer collector member (14).
• This variant makes it possible to no longer trap at least a first end 24, 32 of an upstream tube 22, 30 and an end 42 of a downstream tube 16, as described above with reference to FIGS. 1 and 2.
• the ends 24 and 32 which extend to the first face 13 of the outer member 14 may be in contact with the ends of the exhaust ducts of the cylinder head.
• the end 42 extending to the second face 15 of the outer member 14 may be in contact with one end of the exhaust line of the engine. This configuration ensures a seal to the exhaust gas of the engine.
• the external element 14 is not in direct contact with the exhaust gas, there is no risk of corrosion.
• the tubes 22, 30 and 16 are positioned, with respect to the mold used to form the external element 14, in such a way that they protrude from this external element 14 once this molding operation has been completed.
• the collector 10 may comprise means for preventing the axial displacement of the ends 24, 32 and 42 of the upstream tubes 22, 30 and downstream 16 which extend to the faces 1 3 and 15 of the external element 14. It may for example be grooves or annular shoulders made on the upstream tubes 22, 30 and downstream 16 at the sections that are in contact with the outer member 14, so that, during the casting of the outer element 14, the molten material defines a complementary shape of these means for prevent axial displacement.
• the ends 24, 32 and 42 will therefore be fixed relative to the outer member 14, and can still ensure contact with the ends of the exhaust ducts of the cylinder head and the exhaust line.

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• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Exhaust Silencers (AREA)

Applications Claiming Priority (3)

Publications (1)

Family

ID=35457970

Family Applications (1)

Country Status (4)

Families Citing this family (6)

Family Cites Families (8)

• 2005
  • 2005-09-29 EP EP05800624A patent/EP1797294A1/de not_active Withdrawn
  • 2005-09-29 US US11/575,713 patent/US20080083216A1/en not_active Abandoned
  • 2005-09-29 JP JP2007534062A patent/JP2008514863A/ja not_active Withdrawn
  • 2005-09-29 WO PCT/FR2005/050792 patent/WO2006035188A1/fr active Application Filing

Non-Patent Citations (1)

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