DE102005041826A1 - Metallic flat gasket for thermally loaded connections of fluid-carrying lines - Google Patents

Abstract

The present invention relates to a metallic flat gasket for sealing connections between fluid-carrying lines, the gasket having at least one inner through opening for the fluid and the gasket comprising a carrier layer and a first functional layer which is attached to the carrier layer and has at least one bead, which runs around the inner through opening. The carrier layer and the first functional layer consist of different materials, and the carrier layer protrudes outward from the through opening beyond the functional layer.

Description

The The present invention relates to a metallic gasket for thermal highly loaded connections fluid-carrying lines. It concerns in particular an exhaust gasket for Internal combustion engines with high exhaust gas temperature.

seals for the Connection of exhaust parts such as turbocharger, catalytic converter, muffler, manifold and The like are exposed to high thermal loads. There one efficient combustion possible high temperatures require, these pressures increase in modern day Internal combustion engines on.

For example is an ever stronger Spreading more powerful Diesel engines to observe, due to their specific characteristics especially harmonize well with turbochargers. A turbocharger is due to the inevitable Position far ahead in the exhaust tract a good example of a thermal particularly stressed component. It can sometimes in operation come to the red heat of the turbocharger.

at pure suction motors can the particularly stressed components of the exhaust system on the engine side as far as possible one piece be manufactured, at least until today's catalytic converter, the usually flanged. With such one-piece exhaust sections is the choice of materials less critical. For turbo-charged engines sits the turbocharger between the catalytic converter and the engine, thus further ahead, where higher Exhaust gas temperatures are present. As is the turbocharger usually is a replaceable part, it must also flanged be, with the necessary seals far higher thermal loads have to withstand as the one located farther back in the exhaust tract.

Of the Material of the gasket must be adapted to the corresponding temperature become. The material costs thus increase with increasing flue gas / flange temperature at. Special materials such as Inconel 718 are therefore for them Seals needed. Because the materials are more expensive and sometimes less good or difficult to process, there is a need to to use these high-quality materials only there and only to the extent that so that a tightness with minimal use of materials still guaranteed can be.

It is therefore the object of the present invention, a metallic Flat gasket for to provide thermally highly loaded connections of fluid-carrying lines, which ensures the necessary tightness, and in which the use more expensive and possibly difficult to process materials can be minimized. Thereby can both the costs are significantly reduced, as well as the processing or manufacturing simplified and accelerated.

According to one Aspect of the invention is a metallic gasket for sealing of connections between fluid-conducting Lines provided. The seal has at least one inner Through opening for the Fluid, and comprises a carrier layer, a first functional layer which is mounted on the carrier layer and has at least one bead, which around the inner passage opening around runs.

there exist the carrier layer and the first functional layer of different materials. While the Functional layer consists of a high alloy material, which is particularly temperature-resistant, the carrier layer of a simpler and cheaper Material executed become. The carrier layer protrudes from the passage opening outward over the Functional position addition.

Thereby can in the inventive seal a use of the expensive and possibly difficult material to be processed is kept to a minimum, while the support layer from a cost-effective Material such as spring steel or the like can be made. The functional layer only covers the actual functional area or Sealing area, i. the area that has to withstand the highest temperatures while the carrier layer the rest Part of the seal forms.

In a preferred embodiment The seal further comprises a second functional layer, at least has a bead, which around the inner passage opening around runs, wherein the first and the second functional attitude on opposite surfaces the carrier layer are attached. Depending on the application, it may suffice Provide a functional position on one side, such as when the exhaust gas temperature decreases sharply and the following section of the exhaust tract anyway is cooler. If both sides of the seal are similarly heavily loaded, It may be useful on both sides of the particularly heavy duty Provide functional position.

In a preferred embodiment, the carrier layer is planar in the region which is covered by the first and / or second functional layer. As in the area covered by the functional layer (s), usually a higher temperature prevails, it is preferred that the carrier layer is executed here plan. This is advantageous because it can happen that the carrier layer "softens" at high temperature so that it could flatten out existing beads, which would worsen the sealing properties, whereas at the most a planar area is compressed or the material of the carrier layer becomes slightly compressed, which does not significantly affect the sealing properties.

In a preferred embodiment has the carrier layer in the area covered by the first and / or second functional layer will, a bead on. This can e.g. serve the functional condition form-fitting with the carrier layer connect to.

In a preferred embodiment has / show the first and / or the second functional layer at least two beads on. More than one bead can improve the sealing properties and also increase the stiffness of the seal here. This is however with an elevated one radial expansion at least the functional position bought.

In a preferred embodiment has the carrier layer in the area over the functional position protrudes, at least one bead. Thereby becomes in the "cold area" of the seal a additional Tightness achieved, with no risk that the Beading due to the not very high thermal loadable material the carrier layer soft and flattened or even leveled at high temperatures becomes. The penetration of foreign bodies, gases and liquids from the outside is effectively prevented.

In a preferred embodiment is the carrier layer folded around the edge of the first functional layer, which faces the passage opening. As a result, the carrier layer acts as a stopper for the Functional position, i. due to the material thickening as a result of the folding over a leveling of the bead (s) of the functional position (s) is prevented.

In a preferred embodiment, the carrier layer in the region which projects beyond the functional layer, fastening means for attaching a heat shield. The advantages of a heat shield or the ability to attach such, are associated with 3 described.

In a preferred embodiment The seal further comprises a heat shield attached to the carrier layer attached, e.g. with the above. In a further preferred embodiment are carrier layer and heat shield in one piece educated.

In a preferred embodiment the seal further includes a coating on the first and / or the second functional layer is applied to the micro-density properties to improve.

In a preferred embodiment is the first functional layer folded around the edge of the carrier layer, which is the Through opening is facing. This will be the direct contact between carrier layer and fluid medium prevented. Since the carrier layer less resistant to the This may be due to the action of the fluid (e.g., spring steel) the inner edge of the carrier layer protected.

1 shows a flat gasket according to the invention in a plan view;

2a - 2e show embodiments of the flat gasket according to the invention, in a sectional view along the line AA in 1 ; and

3 shows a further embodiment of the flat gasket according to the invention.

It It should be noted that the following description in the first Line refers to exhaust systems of internal combustion engines, wherein the seal according to the invention but also for all comparable sealing tasks are suitable, i. for all situations, in which thermally highly loaded connections between fluid-carrying Lines must be sealed, i.e. the corresponding fluids have very high temperatures. While in internal combustion engines, the fluids are gaseous exhaust gases, works the seal according to the invention in other situations as well with liquids or equivalent Mixtures.

1 is a plan view of a flat gasket according to the invention 1 , which in this example a through hole 6 for a fluid, for example exhaust gases of a turbo diesel engine. Similarly, seals with more than one such opening are possible in an analogous manner. On a carrier layer 2 is a functional situation 4 attached, wherein the carrier layer 2 about the functional situation 4 protrudes outwards. The functional position 4 So covers only a part of the carrier layer, but is closed in any case around the passage opening around.

Two mounting holes 8th are for the attachment of the seal eg on a turbocharger and the rest of an exhaust system in the carrier layer 2 intended. The carrier layer 2 and the functional position 4 consist of different materials, the functional position 4 made of a high alloy material such as Inconel 718, where whereas the carrier layer is made of a simpler material such as spring steel. The functional position 4 So covers only the actual functional area, while the remaining area of the carrier layer 2 is covered.

This makes it possible, the higher quality and thus usually more expensive and, depending on the nature of consuming more machinable material of the functional position 4 to use only in the functional area, while the rest of the seal can be made of a simpler but cheaper material. So it is also possible, among other things, the fasteners 8th To provide holes for fastening bolts or screws, in the cheaper and possibly easier to work material, and not in the high-quality functional position.

The 2a to 2e show various embodiments of the gasket according to the invention, all representing sectional views taken along the line AA of 1 are included. In each case, the right side in the figure, the inward-facing, ie the fluid exposed side (indicated by the dashed lines). In 3 this is the other way around the left side.

In 2a a variant is shown in which the functional position 4 has two full beads for improved sealing. The carrier layer 2 also has a full bead here. The area of the carrier layer 2 which of the functional position 4 is covered, is plan executed. The bead in the area of the carrier layer pointing to the outside 2 assumes an additional sealing function in the "cold" outdoor area.

2 B represents a variant in which the functional position 4 has a half bead. In the carrier layer 2 is a corresponding half bead available. As in the embodiment of 2a is the carrier layer 2 provided with a full bead outside.

2c is essentially identical to the variant of 2a , wherein the bead in the outer region of the carrier layer 2 here, however, is designed as a half bead.

2d represents a simplified version of the seal of 2c in which the functional position 4 instead of two full beads only one full bead has. The number of beads can be varied depending on the desired sealing properties, with more beads providing improved sealing, while fewer beads provide a correspondingly smaller radial expansion of the functional layer.

In 2e a special embodiment of the seal is shown. Here the carrier layer acts 2 in addition, as a stopper for the gesickte functional position 4 , By crimping the carrier layer 2 around the inner edge of the functional position 4 Effectively prevents the beads in the functional position 4 be completely leveled so that their function is maintained.

In an embodiment not shown can in an analogous manner, the functional position around the carrier layer be folded around, reducing the backing layer, which consists of a less resistant material can exist, even better be called Exhaust gases or the like protected is.

3 is a sectional view of an extended embodiment of the seal according to the invention, which is further a heat shield 12 having. Such a heat shield 12 can be used, for example, to protect temperature-sensitive components on a vehicle from heat radiation and convection. Since, for example, a turbocharger can be brought to red-hot, this is depending on the location of other components a factor not negligible. Plastic sheathed cables, hoses or the like, for example, should not be exposed to high temperatures. However, especially in tight spaces, it may be unavoidable to lay them in the vicinity of hot components such as turbochargers, catalysts or the like. In such cases, an additional heat shield can prevent damage.

Two components are to be connected according to this example, such as a turbocharger 10 ' with another part 10 the exhaust tract. The seal according to the invention has a carrier layer in this embodiment 2 with two functional layers on opposite sides 4 and 4 ' on. At the carrier layer 2 However, here are additional fasteners 14 for fixing a heat shield 12 intended. In the example shown, these are holes in which the heat shield 12 is fastened by means of rivets, screws or the like. Also possible are training to mechanically engage the heat shield, or other known attachment mechanisms.

Since highly heat-resistant materials (such as MICA) for the functional position (s) are partially such that a mounting of a heat shield is not possible, this embodiment of the seal according to the invention, in contrast, the possibility to easily mount such a shield or mounting options for it provided. In the carrier layer, which consists for example of a spring steel, fastening means can be provided easily. In a further embodiment, the carrier layer itself as Heat shield to be trained, or is integrally connected with this.

at the seal according to the invention can the individual layers are connected to each other, for example by spot or laser welding, or you can a form-fitting Have connection. The functional position (s) can / additionally with be provided a coating through which the micro-density properties be improved, i. about microscopic unevenness of the material the functional position are compensated.

Claims (12)

Metallic flat gasket ( 1 ) for sealing connections between fluid-carrying lines ( 10 . 10 ' ), the seal ( 1 ) at least one inner passage opening ( 6 ) for the fluid, and wherein the seal ( 1 ) comprises: - a carrier layer ( 2 ); A first functional position ( 4 ), which are on the carrier layer ( 2 ) and has at least one bead, which around the inner through hole ( 6 ) runs around; wherein - the carrier layer ( 2 ) and the first functional position ( 4 ) consist of different materials; and - the carrier layer ( 2 ) from the passage opening ( 6 ) to the outside via the functional position ( 4 protrudes). Seal according to claim 1, further comprising: - a second functional layer ( 4 ' ) having at least one bead, which around the inner through hole ( 6 ) runs around; wherein the first and the second functional position ( 4 . 4 ' ) on opposite surfaces of the carrier layer ( 2 ) are mounted. Seal according to claim 1, wherein - the carrier layer ( 2 ) in the region that is dependent on the first and / or second functional position ( 4 . 4 ' ) is covered, is plan. Seal according to claim 1, wherein - the carrier layer ( 2 ) in the region that is dependent on the first and / or second functional position ( 4 . 4 ' ) is covered, having a bead. Seal according to one of the preceding claims, wherein - the first and / or the second functional position ( 4 . 4 ' ) has / have at least two beads. Seal according to one of the preceding claims, wherein - the carrier layer ( 2 ) in the area that is above the first functional location ( 4 ) protrudes, having at least one bead. Seal according to one of the preceding claims, wherein the carrier layer ( 2 ) around the edge of the first functional layer ( 4 ), which is the passage opening ( 6 ) is facing. Seal according to one of the preceding claims, wherein - the carrier layer ( 2 ) in the area that is above the first functional location ( 4 protrudes, fasteners ( 14 ) for attaching a heat shield ( 12 ) having. Seal according to one of the preceding claims, further comprising: - a heat shield ( 12 ), which at the carrier layer ( 2 ) is attached. Seal according to claim 9, wherein - the carrier layer ( 2 ) and the heat shield ( 12 ) are integrally formed. Seal according to one of the preceding claims, further comprising: - a coating, which on the first and / or the second functional layer ( 4 . 4 ' ) is applied to improve the micro-density properties. Seal according to one of the preceding claims, wherein the first functional layer ( 4 ) around the edge of the carrier layer ( 2 ), which is the passage opening ( 6 ) is facing.