WO2010020304A1

WO2010020304A1 - Exhaust gas seal

Info

Publication number: WO2010020304A1
Application number: PCT/EP2009/004592
Authority: WO
Inventors: Theofilos Chatziioannidis; Heinz Rosenau
Original assignee: Federal-Mogul Sealing Systems Gmbh
Priority date: 2008-08-20
Filing date: 2009-06-25
Publication date: 2010-02-25
Also published as: DE102008038460A1

Abstract

The invention relates to an exhaust gas seal for sealing two components of an internal combustion engine against each other, comprising a first sheet metal part (2), a through-hole (4), a gas seal (6) extending about the through-hole (4), at least two threaded holes (8) disposed on opposite sides of the gas seal (6) and at a distance therefrom, and at least one depression (10) in the first sheet metal part (2) at each of the two threaded holes (8) extending about each threaded hole (8), wherein the depressions (10) extend in an arc shape, and the depressions (10) extend about a partial region of the half or the entirety of the half of each threaded hole located tangentially opposite the through-hole.

Description

T / EP2009 / 004592

exhaust gasket

The present invention relates to a gasket for an exhaust system of an internal combustion engine, in particular a flange gasket for an exhaust manifold.

Such seals are used for example in the connection between the cylinder head and exhaust manifold and in the exhaust system. A conventional such seal is substantially flat with a passage for the exhaust gases. It has a gas seal which extends around the passage opening. This gas seal can be formed for example by a bead. Furthermore, a known seal has at least two screw holes which are arranged on opposite sides of the gas seal and spaced therefrom.

These seals are heavily loaded in modern engines. Depending on the engine type, exhaust gas temperatures of 650 to more than 1000 ⁰ C may arise. The exhaust manifold is therefore exposed to strong temperature changes, which lead to thermally induced delay, for example, on the manifold flange. During operation of the engine additional vibrations occur, in addition, the engine carries out depending on LäMZusiand in its Aufnängung movements, which are ultimately transmitted to the exhaust manifold.

Even under these conditions, a manifold flange gasket must maintain gas tightness. Gas leaks lead to failure of the seal. It is therefore necessary, inter alia, to maintain a certain pressure of the seal. When using fixing screws, ensure that a uniform screw force is exerted on the seal. Uneven bolt force, for example, due to a loss of screw power with only one mounting screw, can cause the manifold flange bends. Excessive bending, in particular plastic deformation of the manifold leads to leaks and ultimately failure of the seal. It is therefore the object of the present invention to provide an exhaust gasket having improved tightness and durability.

According to one aspect of the invention, an exhaust gasket is provided for sealing two components of an internal combustion engine against each other, comprising a first sheet; a passage opening; a gas seal extending around the through hole; two or more screw holes arranged on opposite sides of the gas seal and spaced therefrom; and at least one bead in the first sheet at each of the at least two screw holes extending around the respective screw hole; wherein - the beads (10) extend in a circular arc; and the beads (10) extend around a partial area of half or around the entire half of the respective screw hole, which lies tangentially opposite the passage opening.

In the exhaust gasket according to the invention beads are provided around the screw holes around in order to reduce in the installed state, the bending of a component to be sealed from the other. If one component, for example, the exhaust manifold and the other component is the exhaust system, so can be reduced by the exhaust gas seal according to the invention, the deflection of the connecting flanges.

The arrangement of the beads around the screw holes makes it possible to distribute the applied screw force, which is caused by the fastening screws, around the screw hole. The distribution can be adjusted so that the influence on the gas seal is kept very low or even the gas sealing force is increased by a redistribution of the screw force. According to one embodiment of the invention, the exhaust gasket further comprises a second plate. This second sheet may be a substantially flat carrier sheet for the first sheet, or also have additional beads, as explained below.

According to an embodiment of the invention, the exhaust gasket comprises a bead in the second sheet at each of the screw holes extending around the respective screw hole.

According to one embodiment of the invention, the exhaust gasket further comprises a third plate between the first and the second plate. This sheet may be a substantially flat carrier sheet for the first and the second sheet.

The use of two sheets with or without a third intermediate / carrier sheet has the advantage that on both sealing surfaces congruent or superimposed screw hole beads can be provided in a simple and cost-effective manner. Thus, the screw hole beads can be introduced into the two sheets (for example, by embossing), which are then joined together. With only one sheet, however, it is not possible to provide congruent Schraubloch-beads. In this case, the screw hole beads can be embossed sections in opposite directions.

According to one embodiment of the invention, the angle of arc of the screw-hole bead (s) is up to 180 °, preferably between 90 ° and 180 °, more preferably about 180 °. Since the screw-hole bead is not a sealing bead in the true sense, it does not necessarily completely surround the respective hole. Rather, by a section-wise arcuate design of the bead embossing can be selectively influenced on the force distribution and the Flanschdurchbiegung.

Thus, for example, by the Schraubloch-beads with an arc angle of, for example, 180 °, a torque introduction significantly reduce the Flanschdurchbiegung, without negative impact on the function of the exhaust gas bead. 92

According to the invention, the angle value of the screw-hole corrugations can be adjusted within a wide range, therefore the reception and distribution of the screw force can be controlled very precisely above this value. An adjustment can be made easily and inexpensively by appropriate choice of the angle and thus the length of the beads. In addition, via the shape of the bead, e.g. Height and width of the cross section can be influenced. The applied in the installed state bolt force should be distributed primarily around the screw hole around, with the influence on the gas seal should be minimized.

In terms of shape and length, when designing the screw-hole bead, it is generally important to ensure that plastic deformation on the flange surfaces is prevented or minimized.

According to one embodiment of the invention, the angle of the arc of at least two beads is different. Thus, a locally different recording and distribution of the screw force can be achieved at two Schraublochsicken.

According to the invention, the beads extend around a portion of the half or around the entire half of the respective screw hole, which lies tangentially opposite the passage opening. For the purposes of the invention, the term "half which lies tangentially opposite the passage opening" is to be understood as follows: Two halves of the respective screw hole are defined by an imaginary line running parallel to the tangent to the passage opening the point of the through hole closest to the screw hole.These two halves defined in this way are understood to mean that "tangential to one another" which faces away from the through hole.

For passage openings, which at least partially have a radius of curvature

- For example, circular or other through-holes with at least partially rounded edge regions - the definition of the "tangentially opposite half" can also be done as follows: To the radius of curvature of the through hole, the passes through the respective screw hole, a vertical is thought through the center of the screw hole. Of the subdivided by these vertical two halves is in turn the one "tangentially opposite", which faces away from the through hole.

In an alternative embodiment, the beads are arranged on the side of the respective screw hole, which faces the gas seal.

According to one embodiment of the invention, the beads are full beads. The introduction of full beads in the or the sheet (s) can be done easily and inexpensively, for example by embossing. Alternatively, you can also use half beads.

According to one embodiment of the invention, the gas seal has a full bead. According to the invention, the gas seal can be effected by full or semi-beading in one or more layers. In the example of the figures shown, a half bead is used by way of example.

According to an embodiment of the invention, the beads in the first sheet are away from the beads in the second sheet.

According to one embodiment of the invention are in the installed state of the exhaust gasket, the components to be sealed only with the beads and the gas seal in contact.

According to one embodiment of the invention, the exhaust gasket is a seal between the internal combustion engine and the exhaust manifold.

Short description of the drawing

Fig. 1 shows a plan view of an embodiment of a seal according to the invention; 009/004592

Fig. 2 shows in a plan from possible embodiments of the Schraubloch-beads of the invention;

Fig. 3 shows a cross-sectional view of an embodiment of a seal according to the invention;

Fig. 4 shows the construction of the screwlock beads according to the invention;

Fig. 5 shows an alternative embodiment of the invention; and

Fig. 6 shows a further alternative embodiment of the invention.

Detailed description of the invention

Fig. 1 shows a seal according to the invention in plan view. The seal comprises a first sheet 2, which has a passage opening 4. A gas seal 6 runs around the passage opening 4. The gas seal 6 can be in the form of a full bead. The sheet 2 further has two screw holes 8, which are arranged on opposite sides of the gas seal 6 and spaced therefrom. In the sheet 2, a bead 10 is provided for each screw hole, which runs around in the form of a circular arc around the corresponding screw hole δ around. In the embodiment shown, the angle of the arc is about 180 °.

By Schraubloch-beads 10, the Flanschdurchbiegung can be reduced by means of seal according to the invention exhaust manifold flange.

The friction surface on the seal is reduced, i. the components to be sealed are in

Essentially only with the gas seal 6 and the Schraubloch-beads 10 in contact, which reduces the friction surface. The beads 10 are arranged around the screw holes 8 such that the applied screw force of fastening screws in the installed state is distributed to the beads 10 around the screw hole. Furthermore, this can reduce the influence of the screw force variance on the gas seal 6. The Distribution of the present Schraubenkralt on the gas seal 6 can be adjusted by appropriate choice of the beads 10.

2 shows in a plan view how the beads 10 can be formed in the gasket according to the invention. The angle α of the arc can be up to 180 °. The

Beads 10 are thus formed open to one side. Preferably, the angle is about

180 °. It can be initiated targeted moments to an adverse

Reduce flange deflection. According to the invention, the open side of the beads

10 tangentially in the direction of the gas seal, or the beads are arranged on the side of the screw hole, which faces away from the gas seal tangentially. The beads 10 can be made as full beads and introduced by embossing in the sheet 2.

Fig. 3 shows the layer structure of an embodiment of the seal according to the invention in cross section. In this embodiment, the seal of a first sheet 2, a second plate 22 and a support plate 12 is constructed. The seal has a through opening 4 and two screw holes 8, each extending through all three sheets. The carrier sheet 12 is substantially flat. The first sheet 2 and the second sheet 22 each have, facing outwardly, a closed full bead 6 extending around the through-opening and forming the gas seal.

In alternative embodiments, the seal according to the invention has only the first sheet 2 and the second sheet 22. In these embodiments, no carrier sheet is provided between the first and second sheets.

Around the screw holes 8 are provided in both sheets 2 and 22 full beads 10, which in this embodiment shown, in contrast to Gasabdichtungssickc 6 not completely or closed to the respective screw holes 8 around. Instead, the beads 10 are open on the side of the respective screw hole 8, which faces the gas seal 6. In other words, the beads 10 are arranged on the side of the respective screw hole, which faces away from the gas seal. The beads 10 extend substantially in the form of a circular arc (not visible in this cross section), which may include an angle α <180 °.

4 shows the course of the screw-hole beads according to the invention. The beads are located exclusively in an area around half of the respective screw hole, which lies tangentially opposite the passage opening. However, the beads do not have to run around the entire half, but can only run around a portion of the half. In the area of the other half, i. the half, which is tangential to the passage opening, do not run any beads.

The term "half, which lies tangentially opposite the passage opening" is to be understood in accordance with the invention as shown in Fig. 4. Two halves of the respective screw hole are defined by a line 34 which extends parallel to the tangent 32 to the passage opening. In this case, this tangent 32 runs through the point of the passage opening which is closest to the screw hole 2. The two halves defined in this way are understood to mean "tangentially opposite", which faces away from the passage opening, and the "tangential facing", the de Passage opening faces.

In through-holes which at least partially have a radius of curvature - for example circular through-holes as shown in Fig. 4, or through-holes with a shape like a stadium or a peanut shell as in Figs. 5 and 6 - the definition of the two halves can also be made as follows , The radius of curvature is defined as the radius of the circle of curvature to a certain point P, which best approximates the curve at that point. To the line 30, which is an extension of the radius of curvature of the through-hole and which passes through the center of curvature of the through-hole and the center of the respective screw hole, a vertical 34 is constructed through the center of the screw hole. This perpendicular 34 in turn defines the two tangentially facing away or facing halves. EP2009 / 004592

In Figures 5 and 6 alternative embodiments of the exhaust gasket of the invention are shown. In the example shown in Fig. 5, the through-hole has approximately the shape of a stadium, i. it is basically rectangular with strongly rounded corners. FIG. 6 shows an exemplary embodiment with a passage opening in the form of a peanut shell. In both examples, the screwlock beads are constructed as shown in Fig. 4, i. they each revolve half of the screw holes, which is tangent to the respective portion of the through hole, while extending around the tangentially facing half no part of the beads.

Claims

/ Claims

1. A gas seal for sealing two components of an internal combustion engine against each other, comprising - a first sheet (2); a passage opening (4); a gas seal (6) extending around the passage opening (4); at least two screw holes (8) on opposite sides of the

Gas seal (6) and spaced therefrom are arranged; and - at least one bead (10) in the first sheet (2) at each of the at least two screw holes (8) extending around the respective screw hole (8); wherein the beads (10) extend in a circular arc; and the beads (10) extend around a portion of the half or the entire half of the respective screw hole, which is tangentially opposite the through hole.

2. A gasket according to claim 1, further comprising a second plate (12, 22).

3. A gasket according to claim 2, further comprising a bead (10) in the second plate (22) on each of the at least two screw holes (8) which extends around the respective screw hole (8).

4. Exhaust gasket according to claim 3, further comprising a third plate (12) between the first (2) and the second plate (22).

5. Exhaust gas seal according to one of the preceding claims, wherein the angle of the circular arc of at least two beads (10) is different.

6. Exhaust gasket according to one of the preceding claims, wherein the beads (10) Are full.

7. Exhaust gas seal according to one of the preceding claims, wherein the gas seal (6) has a full or half bead.

8. Exhaust gasket according to claim 2 or one of claims 3 to 1 1, when dependent on claim 2, wherein the beads (10) in the first sheet (2) of the beads (10) in the second plate (22) point away.

9. exhaust gasket according to one of the preceding claims, wherein in the installed state of the exhaust gasket, the components to be sealed only with the beads (10) and the gas seal (6) are in contact.

10. Exhaust gasket according to one of the preceding claims, wherein the exhaust gasket has a seal for use between internal combustion engine and

Exhaust manifold is.