The invention relates to a flat gasket, in particular to a cylinder head gasket or an exhaust flange gasket.
It is known for the cylinder head gaskets, which consist of several (metal) layers, how to connect to each other the layers, which, when necessary, can be differently built, by using appropriate joining technologies (e.g. clinching, welding). With the help of the so-called stopper members, which are built with additionally inserted rings, layers or stampings, the necessary height difference at the combustion chamber edge is adjusted to the edge surface area of the flat gasket.
A gasket configuration for a combustion engine can be taken from EP 0 538 628 A2, which contains a cylinder head, a motor block and a cylinder liner inserted in a drilled hole of the motor block and supported by it, a hollow cylindrical part, a sealing collar in the form of a ring stretching radially outwards from the cylindrical part, a piston bore and a collar joint surface essentially pointing to the cylinder head and containing further sealants which are engaged with the collar joint surface and a corresponding cylinder head sealing surface in order to prevent the escape of combustion gases from the piston bore. At least one of the two sealing surfaces is built in a frustroconical form and is extending continuously from a radially internal circumferential area to a radially external circumferential area, whereby the radially internal circumferential area is spaced apart farther from the other sealing surface than the radially external area.
The task of the invention is to propose a new sealing concept for flat gaskets in which profile elements that can function as a sealing element are used.
Another objective is to permit the targeted adjustment of the force distribution not only in the sealing system, but also in the remote periphery (hinterland) of the flat gasket which, as a rule, is determined by bolt forces.
The task is solved by means of a flat gasket, in particular a cylinder head gasket or an exhaust flange gasket, containing at least one layer provided with at least one through opening, whereby the through opening receives at least one elastically malleable profile element built as a profile wire with a ring form and with defined material thickness, whereby the full height of the undeformed profile element is larger than the thickness of the layer, and the layer in the area of the profile element and/or outside of the profile element is provided at least partially with material compression.
Other advantageous implementations of the object of the invention are provided in the subclaims.
The material compression can be provided depending on the implementation form by stamping or by adding a coating.
Also combined material compression (stamping+coating) is possible, as well as the applying of a stopper.
If the material compression is built with a coating, a polymer, in particular a thermoplastic or duroplastic material, can offer the same advantages.
It can be advantageous also when the coating contains particles and/or fibers. To this purpose, both metal and also mineral particles can be used individually or in combination, whereby the particles and/or the fibers should have certain thickness.
According to another idea of the invention, the coating can be applied over the respective area of the layer by screen printing.
The material compression can be applied on defined locations along the sections of the layer surrounding the through opening or be applied in such a way that a closed area with a wall thickness that can be specified is built.
It is of a particular advantage that the profile element, seen in radial direction, is built with areas of different material thickness. For example, here the cross section has the form of a banana in which the thickness of the material is largest in the middle area of the radial extension of the profile element and then decreases towards the peripheral areas. In this way, a central core area and an outside elastically deformable area are formed.
The profile body can be either partially connected at least partially with the layer or positioned in the through opening in a radially mobile manner.
It is of a particular advantage that material compression is provided also outside of the profile element. Here we have in mind the so-called hinterland which extends up to the edge areas of the flat gasket. The respective material compression can be provided partially or over larger surface areas in the hinterland and can, if needed, enclose at least partially the bolt through openings.
In this way, an optimal force distribution within the entire gasket can be ensured which affects positively the sealing behavior.
The purpose of the controlled adjustment of the force distribution, in particular the division between the profile element and the layer sections connected to it, is achieved, for example, by means of the height differences between the combustion chamber sealing and the media sealing. If the media sealing and the combustion chamber sealing have the same height (additional precondition: the used seals show the same tightness and rigidity), it can be proceeded from an equal load distribution. If the heights of the media sealing and the combustion chamber sealing are different, higher load can be partially generated. However, in order, for example, that the combustion chamber sealing could take over a higher portion of the bolt forces, it is worked with a supernatant of the combustion chamber sealing. This means that the combustion chamber sealing must be higher than the media sealing.
The height difference between the combustion chamber sealing and the media sealing can be adjusted precisely by means of applying flat or partial material compression on the layer. In this way, both the necessary and also topographic height differences can be implemented in order that, for example, to increase or decrease deliberately the hinterland (for example, by means of coatings with different materials and different particle sizes).
The object of the invention is presented in the figure and will be described in more details further below. The figure shows the following items:
The polymer must contain only a certain portion of particles and fibers which depends on the particle size (the larger the particles are, the higher their portion has to be).
Analogically to
Not shown but included in the protection scope is the point that the respective layer can be provided in a single-sided or double-sided plated form (e.g. aluminum), whereby the material compression can be obtained, for example, by embossment of at least one plated area (in the plating only).
By the use of material compressions either in the layer or in a plated layer, it is possible to prepare specified topographies both in height as well as in width.
Number | Date | Country | Kind |
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10 2008 029 543.4 | Jun 2008 | DE | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/DE2009/000842 | 6/19/2009 | WO | 00 | 12/21/2010 |