Exhaust manifold

Abstract

An exhaust manifold for an exhaust system of an internal combustion engine is disclosed having a housing, an inlet flange which can be fixed to the cylinder head of the internal combustion engine and has a plurality of inlet openings, and an exhaust outlet. The housing comprises an inner shell and an outer shell, an insulating material being incorporated between the outer shell and the inner shell. A guide plate is provided on the inlet flange side of the inner shell and the outer shell. The guide plate has inflow openings which correspond with the inlet openings of the inlet flange and is joined to the inlet flange. The outer shell engages with its inlet flange-side edge around the guide plate and is joined to the inlet flange and the guide plate.

Claims

1. An exhaust manifold for an exhaust system of an internal combustion engine having a cylinder head, comprising: a housing, an inlet flange configured to be attached to the cylinder head of the internal combustion engine, said inlet flange having a plurality of inlet openings and an exhaust outlet, the housing further comprising an inner shell and an outer shell, an insulating material disposed between the outer shell and the inner shell, a guide plate disposed on an inlet flange side of the inner shell and the outer shell, the guide plate has inflow openings which correspond with the inlet openings of the inlet flange and is joined to the inlet flange, the outer shell having an inlet flange-side edge and engages around the guide plate, wherein the outer shell is joined to the inlet flange and the guide plate, the guide plate having positioning elements for positioning the inner shell, the inner shell being mounted in a floating manner relative to the guide plate and the outer shell, and wherein the inner shell is held in position by the insulating material and is pressed in interaction with the outer shell onto the guide plate in a direction of the inlet flange.

2. The exhaust manifold as claimed in claim 1, wherein the positioning elements are configured as guiding members which are formed on the guide plate on a circumferential side of the inflow openings.

3. The exhaust manifold as claimed in claim 1, wherein the positioning elements are of socket-shaped configuration.

4. The exhaust manifold as claimed in claim 1, wherein the inner shell has shell regions of complementary configuration with respect to the positioning elements.

5. The exhaust manifold as claimed in claim 1, wherein the guide plate has an outer flange which is bent over in a direction of the outer shell, and the outer shell engages around the flange.

6. The exhaust manifold as claimed in claim 1, wherein at least one welded opening is provided in the edge of the outer shell.

7. The exhaust manifold as claimed in claim 1, wherein the outer shell has formed recesses which protrude into the region between two inflow openings.

8. The exhaust manifold as claimed in claim 1, wherein a groove which is circumferential at a spacing from the outer edge of the guide plate is provided in the inlet flange.

9. The exhaust manifold as claimed in claim 8, wherein the spacing is dimensioned to be greater than the wall thickness of the outer shell.

10. The exhaust manifold as claimed in claim 9, wherein the inner shell and the outer shell have a connector for a pipe component for providing exhaust gas recirculation.

11. The exhaust manifold as claimed in claim 10, wherein the inner shell has inflow ports, and the inner shell is plugged with the inflow port onto the positioning elements of the guide plate and engages around them in a positively locking but positionally displaceable manner.

Description

(1) The invention is described in greater detail in the following text using exemplary embodiments which are shown in the drawings, in which:

(2) FIG. 1 shows the exhaust manifold with an exploded illustration of its essential components,

(3) FIG. 2 shows the exhaust manifold in a side view, partially in a longitudinal section,

(4) FIG. 3 shows the exhaust manifold in a view according to the arrow III, once again in a partially sectioned illustration,

(5) FIG. 4 shows an enlarged illustration of the detail A from FIG. 3,

(6) FIG. 5 shows an enlarged illustration of the detail B from FIG. 2,

(7) FIG. 6 shows an enlarged illustration of the detail C from FIG. 2, and

(8) FIG. 7 shows a vertical cross section through a further embodiment of an exhaust manifold.

(9) An exhaust manifold 1 according to the invention for an exhaust system of an internal combustion engine is described using the illustrations of FIGS. 1 to 6. FIG. 7 shows a modification of the exhaust manifold 1. The exhaust manifold 1 can be fixed to a cylinder head (not shown here) of an internal combustion engine in a motor vehicle.

(10) The exhaust manifold 1 comprises a housing 2 with an inlet flange 3 and an exhaust outlet 4. The mounting of the exhaust manifold 1 on the cylinder head of the internal combustion engine takes place via the inlet flange 3. The inlet flange 3 has a plurality of inlet openings 5, via which the exhaust gas which exits from the individual cylinders is transferred into the exhaust manifold 1. The exhaust gas is fed via the exhaust outlet 4 to downstream components of the exhaust system, for example an exhaust gas turbocharger 6 as shown here.

(11) The housing 2 comprises an inner shell 7 and an outer shell 8. The inner shell 7 consists of two shell parts, namely an upper shell 9 and a lower shell 10. The outer shell 8 is also assembled from two shell parts, namely an upper shell 11 and a lower shell 12. The shell parts 9, 10 and 11, 12 of the inner shell 7 and the outer shell 8 are connected to one another at their edges which overlap one another in each case, usually joined using welding technology.

(12) The outer shell 8 surrounds the inner shell 7 with the formation of a gap 13. An insulating material 14 is incorporated in the gap 13. The insulating material 14 is provided in the form of a hood element 15. The hood element 15 is adapted configuratively on the outer side to the inner contour of the outer shell 8 and on the inner side to the outer contour of the inner shell 7.

(13) The exhaust outlet 4 is formed by an outlet port 16 in the upper shell 9 of the inner shell 7 and an outlet port 17 in the upper shell 11 of the outer shell 8. The insulating material 14 which is incorporated between the inner shell 7 and the outer shell 8 or the hood element 15 has a through opening 18 which is adapted configuratively to the outlet ports 16, 17. The outlet port 16 of the inner shell 7 engages through the through opening 18 and protrudes as far as into the outlet port 17 of the outer shell 8.

(14) A guide plate 20 is provided on the side 19 which faces the inlet flange 3, that is to say on the inlet flange side of the inner shell 7 and the outer shell 8. The guide plate 20 has inflow openings 21. The inflow openings 21 correspond with the inlet openings 5 in the inlet flange 3. Positioning elements 22 in the form of socket-shaped eyelets or sockets 23 which are formed on the guide plate 20 are configured on the circumferential side of the inflow openings 21. The positioning elements 22 serve to position the inner shell 7 in the housing 2 relative to the guide plate 20 and to the outer shell 8. Furthermore, the positioning elements 22 act as guiding members for the exhaust gas which comes from the cylinder outlets, flows in via the inflow openings 21 and is collected in the interior of the inner shell 7.

(15) The positioning elements 22 are formed in or on the guide plate 20 integrally and from one piece. This can advantageously take place during the production of the inflow openings 21. Here, the positioning elements 22 are formed in a socket-shaped manner or as sockets 23 in the manner of an eyelet from the plane of the guide plate 20. The positioning elements 22 are flared inward into the housing 2.

(16) The inner shell 7 has shell regions 24, 25 of complementary configuration with respect to the positioning elements 22. The shell regions 24, 25 of the upper shell 9 and lower shell 10 which complement one another form inflow ports 26 of the inner shell 7. The inner shell 7 is plugged by way of the inflow ports 26 onto the positioning elements 22 of the guide plate 20 and engages around said positioning elements 22 in a positively locking but positionally displaceable manner. The insulating material 14 holds the inner shell 7 in position, but nevertheless allows mechanical or thermal length changes without disadvantageous stresses occurring.

(17) The outer shell 8 or the upper shell 11 and the lower shell 12 of the outer shell 8 has/have formed recesses 27. The latter protrude into the region between two inflow openings 21. The accessibility of the lower mounting openings 28 in the inlet flange 3 is realized by the formed recesses 27 in the lower shell 12. Further mounting openings in the inlet flange 3 are designated by 29.

(18) During the manufacture of an exhaust manifold 1, the guide plate 20 is joined at the inlet flange 3. Subsequently, the inner shell 7 is placed onto it and is positioned via the positioning elements 22. Afterward, the insulating material 14 is laid or placed around the inner shell 7. The hood element 15 comprising the insulating material 14 has, as has already been stated, a configuration which is adapted to the inner contour or outer contour of the outer shell 8 or the inner shell 7, respectively. The insulating material 14 has both sound absorbing and thermally insulating properties.

(19) The outer shell 8 is placed over the arrangement comprising guide plate 20, inner shell 7 and insulating material 14. With its edge 30 which is directed toward the inlet flange 3, that is to say the inlet flange-side edge 30, the outer shell 8 is placed over the guide plate 20 and engages around the latter. Here, the inner wall 31 of the edge 30 bears against the outer edge 32 of the guide plate 20. Subsequently, the outer shell 8 is joined to the inlet flange 3 and the guide plate 20. This takes place by way of welding. Here, the join is made circumferentially around the outer shell 8. A circumferential groove 33 which is arranged at a spacing a from the outer edge 32 of the guide plate 20 is provided in the inlet flange 3. As FIG. 3 and FIG. 7 show, the spacing a is greater than the wall thickness s of the outer shell 8. The groove 33 is provided in order to assist the welded joining between the inlet flange 3 and the outer shell 8.

(20) Furthermore, welded openings 34 which are distributed on the circumference are provided in the edge 30 of the outer shell 8. The guide plate 20 is also welded in said regions to the inlet flange 3 and the outer shell 8 via the welded openings 34 during the welding operation. The welded openings 34 are closed in a gas-tight manner during the welding operation.

(21) The inner shell 7 is held in position by the insulating material 14 and is pressed in the direction of the inlet flange 3 in interaction with the outer shell 8.

(22) FIG. 3 and the detailed illustration of FIG. 4 show that the guide plate 20 has an outer flange 35 which is bent over in the direction of the outer shell 8. The flange 35 is engaged around by the edge 30 of the outer shell 8 or the outer shell 8 is plugged with its edge 30 over the flange 35. The inner wall 31 in the region of the edge 30 of the outer shell 8 bears against the flange 35 on the outside. Subsequently, the outer shell 8 is welded to the inlet flange 3 and the guide plate 20. The flange 35 assists stable holding and joining of the outer shell 8 to the guide plate 20 and the inlet flange 3.

(23) In that design variant of the exhaust manifold 1 which is shown in FIG. 7, the outer edge 32 of the guide plate 20 butts obtusely against the inner wall 31 of the outer shell 8. Otherwise, the illustration corresponds to the above-described embodiment of the exhaust manifold 1.

(24) Furthermore, the inner shell 7 and the outer shell 8 also have a connector 36 for a pipe component 37 of the exhaust gas recirculation means. The pipe component 37 is incorporated between the connector 36 and an opening 38 in the inlet flange 3.

LIST OF DESIGNATIONS

(25) 1Exhaust manifold 2Housing 3Inlet flange 4Exhaust outlet 5Inlet opening 6Exhaust gas turbocharger 7Inner shell 8Outer shell 9Upper shell of 7 10Lower shell of 7 11Upper shell of 8 12Lower shell of 8 13Gap 14Insulating material 15Hood element 16Outlet port of 7 17Outlet port of 8 18Through opening 19Side of 7, 8 20Guide plate 21Inflow opening 22Positioning element 23Socket 24Shell region 25Shell region 26Inflow port 27Formed recess 28Mounting opening 29Mounting opening 30Edge of 8 31Inner wall of 30 32Outer edge of 20 33Groove 34Welded opening 35Flange 36Connector 37Pipe component 38Opening aSpacing sWall thickness of 8