DE102004051680B4 - Arrangement for fastening an exhaust manifold - Google Patents

Abstract

arrangement for mounting an exhaust manifold on a cylinder head of an internal combustion engine, comprising an exhaust pipe (4) with a connector body (5) and a connector body (5) against the cylinder head (1) pressing retaining element (6), wherein the holding element (6) over Clamping means detachable is attached to the cylinder head (1) and wherein the connecting body (5) Made of sheet metal and a radially encircling, issued to the outside Flange collar (8), wherein the connection body (5) with play through a passage opening (9) of the annular configured holding element (6) and extends from the flange collar (8) of the connection body (5) is engaged behind, characterized in that the flange collar (8) of the holding element (6) incorporating a seal (12) is pressed against the cylinder head (1) and the retaining element (6) a circumferential recess (10, 11) for receiving the flange collar (8), wherein the recess (10, 11) on both sides of the retaining element (6) is formed.

Description

The The invention relates to an arrangement for fastening an exhaust manifold a cylinder head of an internal combustion engine with the features in Preamble of claim 1.

The attachment of an exhaust manifold to a cylinder head of an internal combustion engine is generally carried out by screwing a head flange of the exhaust manifold with, for example, three screws per exhaust passage on the cylinder head. The type of attachment is crucial for the life of the components, since the high exhaust gas temperatures cause a very strong heating of the exhaust gas leading components. In addition, there is a relatively high temperature gradient in the transition region from the cylinder head to the exhaust gas leading components, since the cylinder head is permanently cooled. The thermal changes in length in the cylinder head and in the exhaust gas leading components are greatly different due to the large temperature gradient. In the hot sections of the exhaust manifold arise stresses that lead to the flow of the material and can significantly reduce the life of the exhaust manifold. In order to avoid such damage, for example, clamping compounds have been proposed ( DE 196 53 908 A1 ). Cast iron flanges as well as metal flanges count for example through the DE 296 15 840 U1 to the state of the art. Sheet metal flanges generally contribute to an increase in service life, since sheet metal has a greater elasticity than cast iron.

The exclusively screw-technical fixation of an exhaust manifold on the cylinder head leads in the As a rule, high thermal stresses in the transition area between the head flange and the manifold pipes and the exhaust manifold occur. The clamping fixation usually requires one increased Space. The with the use of flanges made of sheet metal forming technology Required radius of at least 3 mm causes manufacturing reasons additional Space for the head flange gasket is required. Kopfflanschdichtungen From sheet metal have the disadvantage that usually a two- or one three-layer head flange gasket must be used, since not It can be excluded that the head flange in critical areas Relieves relatively easily from the cylinder head.

From the DE 197 43 399 A1 goes out a flange for a multi-flow exhaust system of motor vehicles. The flange is arranged on the engine head and serves to transfer exhaust gases into several exhaust pipes. The flange is multilayered composed of several stamped and shaped parts. The durability of the joint is improved in that an additional stamped or formed part is provided from sheet metal, which goes off an exhaust pipe and rests against the engine block.

The DE 198 07 312 A1 also discloses a connection device for an exhaust pipe to an internal combustion engine. A sealing flange is pressed by incorporating a sealing element from a mounting flange against an engine block. In this way, exhaust gas from the engine block in an exhaust pipe can be transferred. The holding element has a recess for receiving the sealing flange.

The EP 0 178 430 A1 shows a connector body with a paragraph, which is connected to a flange and in which an exhaust pipe is inserted fluid-tight.

Of the Invention is based on the object, an arrangement for attachment an exhaust manifold to provide on a cylinder head of an internal combustion engine, which ensures a safe system of the exhaust manifold on the cylinder head and at the same time requires little space.

These Task is in an arrangement with the features of the claim 1 solved.

at the inventive arrangement the exhaust pipe comprises a connection body and a connection body against pushing the cylinder head Holding member. The holding element is releasably connected via clamping means attached to the cylinder head. The connection body consists of sheet metal and has a radially encircling, outwardly flared flange collar, of the holding element with inclusion of a seal against pressed the cylinder head becomes. In this case, the connecting body extends with clearance through a passage opening of the annular configured Retaining element and is engaged behind by the flange collar of the connection body.

The holding element has a circumferential recess for receiving the flange collar. The recess may be formed on both sides of the retaining element. The recess makes it possible to bring the holding element closer to the cylinder head, wherein for clamping, in particular for screwing, the retaining element with the cylinder head, a gap between the holding element and the cylinder head must remain. In the recess, the flange collar is guided exactly. The inner diameter of the recess is chosen larger than the outer diameter of the flange collar. If recesses are arranged on both sides of the holding element, the holding element is a turning component, that is mutually applicable. In this case, the holding member can be manufactured with only one tool set for an internal combustion engine. This is for example advantageous in V6 engines, in which exhaust manifold on both sides of the engine featured see are.

These embodiment is extremely compact and has the advantage of having an elastic transition area created between the exhaust pipe and the cylinder head, which positively affects the life of the exhaust manifold. critical Among other things, the connection body is made of sheet metal. by virtue of the clamping fixation of issued flared collar can the material thickness of the tinny connection body be relatively low. in principle it is sufficient if the connection body has the same wall thickness like the exhaust pipe. At low wall thicknesses are also low bending radii realizable. In the context of the inventive arrangement is located the bending radius in the immediate vicinity of the outlet channel and not as with flanges made of sheet metal components with welded exhaust pipes at a greater distance to Outlet channel. This is a more compact design than head flanges made of sheet metal components possible. Furthermore occur in the transition area between connection body and cylinder head due to the tight bending radius only very small disorders the exhaust stream on.

Essential is also that the connection body the passage opening interspersed with game. In this way, an increased elasticity in the transition region the exhaust pipe to the cylinder head exists, whereby the life the exhaust manifold elevated becomes.

advantageous Embodiments of the invention are the subject of the dependent claims.

Of the connection body can be made directly from the exhaust pipe of the exhaust manifold, wherein the Holding element for mounting previously on the exhaust pipe or on the the exhaust pipe in one piece trained connection body is postponed. If the pipe run of the exhaust pipe allows it, the Retaining element also subsequently, However, before assembling the individual exhaust pipes on a individual exhaust pipe are pushed.

Basically It is also conceivable that the holding element with the flange collar for Example by spot welding or soldering connected is. For cylinder heads with several outlet channels it is conceivable that the holding element has a plurality of through holes for one having corresponding number of connection bodies and exhaust pipes. The inventive arrangement is for different outlet channel cross sections suitable, such as round, oval or kidney-shaped Outlet cross.

In a further embodiment has the connection body leading an exhaust Middle part on which on the one hand, the flange collar connects and to on the other hand, the exhaust pipe fluid-tight as a separate component followed. The For this purpose, the exhaust pipe can be welded to the sheet metal connection body. But it is also possible that the exhaust pipe in a receiving portion enlarged in diameter of the connector engaging. Also, the reverse configuration, in which the exhaust pipe the connector externally surrounds, is possible. For this purpose, a correspondingly enlarged receiving portion on the exhaust pipe be provided.

Essential is that elasticity in the transition area to the cylinder head is maintained, regardless of how the exhaust pipe is attached to the formed as a separate component connector body. If an enlarged diameter receiving portion of the exhaust pipe or on the fitting is provided, the inner diameter of the central passage opening of the Be holding element larger as the outer diameter of the recording section to the required game and thus the desired elasticity to ensure.

The invention will be explained in more detail with reference to the embodiment schematically illustrated in the figure. The figure shows a portion of a cylinder head 1 an internal combustion engine in the region of an exhaust passage 2 , The from the exhaust duct 2 exiting exhaust gases are in an exhaust manifold 3 passed, which is shown only partially. The exhaust manifold 3 includes an exhaust pipe 4 and one with the exhaust pipe 4 fluid-tight connection body 5 , exhaust pipe 4 and connection body 5 are welded together in a manner not shown. The connection body 5 is via a retaining element 6 on the cylinder head 1 attached. This is in the retaining element 6 at least one through hole 7 provided, in which a screw not shown, can be used. Other non-illustrated through holes 7 lie outside the cutting plane.

Central component of the arrangement for fastening the exhaust manifold 3 on the cylinder head 1 is the connection body 5 , The connection body 5 is a separate, consisting of sheet metal component with a radially encircling, issued flared collar 8th , The connection body 5 interspersed with game a central through hole 9 of the annular configured holding element 6 , The outer diameter A of the flange collar 8th is larger than the inner diameter I of the central passage opening 9 so that the flange collar 8th the holding element 6 engages behind. The flange collar 8th lies here in a circumferential recess 10 whose inner diameter I1 is significantly larger is the outer diameter A of the flange collar 8th , As a result, manufacturing tolerances can be compensated within certain limits. In this embodiment, another recess 11 on the cylinder head 1 opposite side of the retaining element 6 educated. The holding element 6 is mirror-symmetrical with respect to its in the image plane vertically extending central transverse plane MQE, so that the holding element 6 can be used as a turning component.

Between the flange collar 8th and the cylinder head 1 is a seal 12 held clamped. The connection body 5 has in this embodiment an exhaust gas leading cylindrical middle part 13 , whose inner diameter I2 the inner diameter of the exhaust pipe 4 and the inner diameter of the exhaust passage 2 in the cylinder head 1 equivalent. At the cylindrical middle part 13 closes over a bending radius on the cylinder head side of the flared by 90 ° flared flange collar 8th at. On the cylinder head 1 opposite side of the middle part 3 closes a diameter enlarged receiving section 14 in which the exhaust pipe 4 intervenes. The outer diameter A1 of the receiving portion 14 is smaller than the inner diameter I of the through hole 9 , The recording section 14 closes as close as possible to the passage opening 9 and begins in this embodiment immediately after the holding element 6 , In this embodiment, which is located between the middle part 13 and the receiving section 14 extending and funnel-shaped widening transition section 15 almost completely within the passage opening 9 of the holding element 6 ,

1

cylinder head

2

Exhaust duct in 1

3

exhaust manifold

4

Exhaust pipe v. 3

5

Connection body v. 3

6

Holding element v. 3

7

Through hole in 6

8th

Flange collar v. 5

9

Passage opening in 6

10

Recess in 6

11

Recess in 6

12

poetry

13

Middle section v. 5

14

Receiving section v. 5

15

Transitional section v. 5

A

Outside diameter v. 8th

A1

Outside diameter v. 14

I

Inner diameter v. 9

I1

Inner diameter v. 10

I2

Inner diameter v. 13

MQE

Median transverse plane v. 6

Claims (5)

Arrangement for fastening an exhaust manifold to a cylinder head of an internal combustion engine, comprising an exhaust pipe ( 4 ) with a connection body ( 5 ) as well as the connection body ( 5 ) against the cylinder head ( 1 ) pressing retaining element ( 6 ), wherein the retaining element ( 6 ) via clamping means releasably on the cylinder head ( 1 ) and wherein the connection body ( 5 ) consists of sheet metal and a radially encircling, flared flange collar ( 8th ), wherein the connecting body ( 5 ) with play through a through hole ( 9 ) of the annularly configured retaining element ( 6 ) and from the flange collar ( 8th ) of the connection body ( 5 ) is engaged behind, characterized in that the flange collar ( 8th ) of the retaining element ( 6 ) under inclusion of a seal ( 12 ) against the cylinder head ( 1 ) and the retaining element ( 6 ) a circumferential recess ( 10 . 11 ) for receiving the flange collar ( 8th ), wherein the recess ( 10 . 11 ) on both sides of the retaining element ( 6 ) is trained. Arrangement according to claim 1, characterized the retaining element surrounds two or more connecting bodies. Arrangement according to claim 1 or 2, characterized in that the connecting body ( 5 ) an exhaust gas leading middle part ( 13 ), on which on the one hand the flange collar ( 8th ) and on which, on the other hand, an exhaust pipe ( 4 ) is fluid-tightly connected as a separate component. Arrangement according to claim 3, characterized in that the exhaust pipe ( 4 ) in a diametrically enlarged receiving portion ( 14 ) of the connection body ( 5 ) intervenes. Arrangement according to claim 4, characterized in that the inner diameter (I) of the central passage opening ( 9 ) of the retaining element ( 6 ) is greater than the outer diameter (A1) of the receiving portion ( 14 ).