Cylinder head with connected exhaust manifold of an internal combustion engine

Abstract

A cylinder head with connected exhaust manifold of an internal combustion engine the cylinder head has an exhaust duct ending at a cylinder head connecting face to which the exhaust manifold is connected. A flange bushing insert having a bushing part and an end-side flange, is inserted into an exhaust gas duct of the cylinder head. The bushing part has a radially protruding, circumferential bead as a spacer and sealing element that bears against the exhaust duct inner wall. The flange projects at the end of the flange bushing insert and is clamped between the cylinder head connecting face and the exhaust manifold connecting face such that a circumferential insulating gap.

Claims

1. A cylinder head assembly of an internal combustion engine, comprising: a cylinder head having at least one exhaust duct that ends at an outer cylinder head connecting face; an exhaust manifold having an assigned exhaust manifold connecting face that is connected to the outer cylinder head connecting face of the cylinder head; at least one screw connection that connects the cylinder head to the exhaust manifold; a flange bushing insert inserted into the at least one exhaust duct of the cylinder head, having: a bushing part that has at least one radially protruding, circumferential bead as a spacer and sealing element with which the bushing part bears against an exhaust duct inner wall; and an end-side flange part that projects in an annular disc shape radially at an outer end of the flange bushing insert and is clamped between the outer cylinder head connecting face and the exhaust manifold connecting face, the flange part being supported axially with at least one circumferential, elastically formed bead, on the outer cylinder head connecting face, the flange part being clamped directly between the outer cylinder head connecting face and the exhaust manifold connecting face without intervening elements as at least one of a sealing flange and for axial bushing fixing, wherein the flange part projects axially in a direction of the exhaust manifold so that it clamps the flange part as a sealing element during mounting; and a circumferential thermally insulating gap that is uncoupled from an exhaust gas flow having a gap width corresponding to a bead height of the circumferential bead bounded by the exhaust duct inner wall, an outer wall of the bushing part, the flange part, and the at least one radially protruding, circumferential bead.

2. The cylinder head assembly according to claim 1, wherein the flange bushing insert is produced at least one of: in one piece; of uniform material; from a heat-resistant material; from an elastic material; and from a metallic substance.

3. The cylinder head assembly according to claim 1, wherein at least one of a thermal insulating element and a thermal insulating material is fitted at least in partial regions of the circumferential thermally insulating gap on the outer wall of the bushing part.

4. The cylinder head assembly according to claim 3, wherein the at least one of a thermal insulating element and a thermal insulating material is formed by at least one of a coating, an insulating material bushing, and at least one insulating material shell.

5. The cylinder head assembly according to claim 3, wherein the at least one of a thermal insulating element and a thermal insulating material is pushed on the bushing part.

6. The cylinder head assembly according to claim 1, wherein at least one bead is arranged in an axial bushing part end region of the bushing part opposite the flange part.

7. The cylinder head assembly according to claim 1, wherein a length of the bushing part substantially corresponds to a length of the at least one exhaust duct in the cylinder head.

8. The cylinder head assembly according to claim 1, wherein the flange part lies in an annular groove of the outer cylinder head connecting face.

9. The cylinder head assembly according to claim 8, wherein the flange part is supported axially with at least one circumferential, elastically formed bead in the annular groove of the outer cylinder head connecting face.

10. The cylinder head assembly according to claim 1, wherein a sealing ring that protrudes in a direction of the exhaust manifold is provided on the flange part.

11. The cylinder head assembly according to claim 1, wherein the at least one of a thermal insulating element and a thermal insulating material is fitted in the insulating gap width.

12. The cylinder head assembly according to claim 1, wherein a first face portion of the flange part is in direct contact with the outer cylinder head connecting face and a second face portion of the flange part, which is axially opposite the first face portion, is in direct contact with the exhaust manifold connecting face.

13. A vehicle, comprising: an internal combustion engine having: a cylinder head assembly, comprising: a cylinder head having at least one exhaust duct that ends at an outer cylinder head connecting face; an exhaust manifold having an assigned exhaust manifold connecting face that is connected to the outer cylinder head connecting face of the cylinder head; at least one screw connection that connects the cylinder head to the exhaust manifold; a flange bushing insert inserted into the at least one exhaust duct of the cylinder head, having: a bushing part that has at least one radially protruding, circumferential bead as a spacer and sealing element with which the bushing part bears against an exhaust duct inner wall; and an end-side flange part that projects in an annular disc shape radially at an outer end of the flange bushing insert and is clamped directly between the outer cylinder head connecting face and the exhaust manifold connecting face without intervening elements, the flange part being supported axially with at least one circumferential, elastically formed bead, on the outer cylinder head connecting face, the flange part is clamped between the outer cylinder head connecting face and the exhaust manifold connecting face as at least one of a sealing flange and for axial bushing fixing, wherein the flange part projects axially in a direction of the exhaust manifold so that it clamps the flange part as a sealing element during mounting; and a circumferential thermally insulating gap that is uncoupled from an exhaust gas flow having a gap width corresponding to a bead height of the circumferential bead bounded by the exhaust duct inner wall, an outer wall of the bushing part, the flange part, and the at least one radially protruding, circumferential bead.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention will be explained in greater detail further by way of example on the basis of a schematic drawing.

(2) FIG. 1 is a section through an exhaust duct of a cylinder head with connected exhaust manifold, and

(3) FIGS. 2a and 2b are two exemplary embodiments of a flange bushing insert inserted into an exhaust duct.

DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENTS

(4) A longitudinal section through an exhaust duct 1 of a cylinder head 2 of an internal combustion engine is represented in FIG. 1. Exhaust duct 1 lies on the outflow side downstream of an outlet valve 3 and is partially surrounded by cooling ducts 4, 5 through which cooling medium flows.

(5) Exhaust duct 1 ends at an outer cylinder head connecting face 6, to which here, by way of example by several screw connections or screw joints 7, an exhaust manifold 8 is connected in an exhaust gas-impervious manner with its assigned exhaust manifold connecting face 9.

(6) A flange bushing insert 10, which is represented in an enlarged form with further details in FIGS. 2a and 2b, is inserted into exhaust duct 1 in a linear region:

(7) Here, flange bushing insert 10 is constructed from a bushing part 11 and an end-side flange part 12.

(8) In a first embodiment according to FIG. 2a (upper region of FIG. 2), bushing part 11 has, opposite flange part 12, two beads 13a, 13b lying next to one another as spacers and sealing elements with which bushing part 11 bears against the exhaust duct inner wall. As a result, a thermally insulating, circumferential insulating gap 14 is formed as an air gap in accordance with the bead height between flange part 12 and bead 13b.

(9) In a second, alternative embodiment according to FIG. 2b (lower region of FIG. 2), only one circumferential bead is fitted opposite flange part 12 as a spacer and sealing element and the bushing part has on the outside a thermal insulating element and/or material, here, for example, a coating 16 with thermally insulating material that fills the air gap of the first embodiment according to FIG. 2a and is also extended into the region of flange part 12 only by way of example here. Alternatively to the coating, an insulating material bushing that can be pushed on or at least one insulating material shell could also be provided, which is then of substantially the same design as coating 16 in terms of the shown installation state.

(10) By way of example here in the case of the two embodiments according to FIG. 2a and FIG. 2b, flange part 12 lies in each case in an annular groove 17 of cylinder head connecting face 6. In the first embodiment according to FIG. 2a, flange part 12 is supported axially with a circumferential, elastic bead 18 on cylinder head connecting face 6 or in annular groove 17 of cylinder head connecting face 6 and projects axially in the direction of exhaust manifold 8 or protrudes so that it clamps flange part 12 as a sealing element during mounting. In the embodiment according to FIG. 2b, a sealing ring 19 protruding in the direction of exhaust manifold 8, possibly with a uniform material to coating 16, is fitted here by way of example on flange part 12. It will be obvious that the sealing solutions (bead 18 and sealing ring 19) on cylinder part 12 can also be used in combination with one another here and can also be swapped, i.e. sealing ring 19 in combination with the configuration in the upper region of FIG. 2b and bead solution 18 in combination with the configuration in the lower region of FIG. 2b.

(11) With flange bushing insert 10, here, two functions, namely the thermal insulation of exhaust duct 1 with bushing part 11 and sealing of exhaust manifold 8 with flange part 12, are combined in a single component, the production and mounting of which is possible in a very simple manner.

(12) Thus, while there have shown and described and pointed out fundamental novel features of the invention as applied to a preferred embodiment thereof, it will be understood that various omissions and substitutions and changes in the form and details of the devices illustrated, and in their operation, may be made by those skilled in the art without departing from the spirit of the invention. For example, it is expressly intended that all combinations of those elements and/or method steps which perform substantially the same function in substantially the same way to achieve the same results are within the scope of the invention. Moreover, it should be recognized that structures and/or elements and/or method steps shown and/or described in connection with any disclosed form or embodiment of the invention may be incorporated in any other disclosed or described or suggested form or embodiment as a general matter of design choice. It is the intention, therefore, to be limited only as indicated by the scope of the claims appended hereto.