KR20050033843A - An air-gap manifold - Google Patents

Abstract

An air-gap manifold is provided to thermally expand an exhaust gas guide of an inner part by connecting the inner part by sliding-fit and to secure high airtightness of the air-gap manifold. In an air-gap manifold for connecting an exhaust gas outlet port of an engine to an exhaust gas inlet port of an exhaust gas system, the exhaust gas system is composed of an inner part(1) having a plurality of exhaust gas guides(2,3,4) connected to each other by sliding-fit; an outer part(5) produced by an airtight method to cover the inner part; and an air gap(6) formed between the inner and outer parts. At least a portion of the exhaust gas guides of the inner part is formed by shells connected to each other by a general reshaping of a rim, especially by folding.

Description

Air-Gap Manifolds {AN AIR-GAP MANIFOLD}

The present invention relates to an air-gap manifold that connects an exhaust gas exhaust port of an internal combustion engine, in particular an automobile engine, to an exhaust gas intake port of an exhaust gas system, wherein the air-gap manifolds are connected to each other in a sliding fit manner. An interior having a plurality of connected exhaust gas guides, an exterior surrounding the interior, an air-gap in a gastight state is formed between the interior and exterior, and at least some of the interior exhaust gas guides It is formed by shells interconnected by folding for general reforming, in particular to reduce manufacturing costs.

There may be several methods of manufacturing the air-gap manifold. Pipe bends are common and the pipes can be made particularly precisely by internal high pressure molding. However, this manufacturing method is relatively expensive. On the other hand, in order to comply with increasingly stringent exhaust regulations, manifolds must be manufactured outwardly airtight.

It is an object of the present invention to provide an air-gap manifold of the aforementioned kind which is easy to manufacture on the one hand and on the other hand can comply with the exhaust regulations.

This object is satisfied that at least a portion of the internal exhaust gas guide is formed by shells which are connected to one another by general reforming of the rim, in particular by folding.

Designing the internal exhaust gas guide using the shell is particularly advantageous in terms of manufacturing costs. On the one hand, the shell is preferable in terms of cost. On the other hand, connecting the shell by general reforming of the rim, in particular by folding, is particularly preferred for manufacturing. Many cost-benefit results for welded connections, especially when manufacturing without weld splashes, are required for exhaust manifolds for turbochargers. Expensive laser and inert arc welding techniques can be considered. The reforming connection of the shell according to the invention can be carried out on the one hand without a welding splash and on the other hand with little effort. Leakage prevention of the remodeling connection between the shells is sufficient because the outer shell of the manifold is completely airtight, so the low airtightness inside is not a problem.

The cost is further reduced if the outside is also configured as a shell. The exterior can also be manufactured at a relatively low cost. Assembly of the manifold is also simplified.

In particular, sheet metals can be considered as materials for the inner shell and / or the outer shell. The inner metal sheet thickness, unlike welding, can be kept relatively small because no minimum thickness is required to reshape the shell. Thus, different types of steel can be used, for example, austenitic steel.

In order to ensure sufficient rigidity of the exhaust gas guide despite the thin thickness of the material, a bead may be provided in the inner shell. The outer shell may also have beads to increase stiffness.

The outer shells are preferably welded to each other. This ensures a high level of leakage protection. The weld connection can be arranged outside because there is no risk of contamination of the interior of the exhaust manifold. This allows a more cost effective welding method to be used.

To prevent displacement of the inner shell in use, the inner shells can be latched together by separate spot welding. Since individual spot welding is only necessary to reliably prevent displacement, a simple spot welding position can be used for this without excessively increasing costs. Alternatively or additionally, the shells can be cast together.

The outside is preferably composed of two half-shells. The exhaust gas guide is also preferably composed of two half-shells each. Thus particularly preferred production and assembly are possible. It has also been found that it is desirable to dispose the separating faces of the inner shell and the outer shell at approximately right angles to each other.

The air-gap embodiment according to the invention is particularly preferred for use in an internal combustion engine with a turbocharger, since the manifold according to the invention can be produced particularly cost-effectively without welding splash.

In the air gap manifold according to the present invention, each of the inner shells forming one portion of the exhaust gas guide is fitted to each other in a sliding fit manner, and the shells forming the other portion of the exhaust gas guides are similarly fitted in the sliding fit manner. It is preferred that the combined shells of the exhaust gas guides, which are fitted together according to one another, are then reshaped, in particular folded, in pairs at the rim.

In the present invention, the exhaust gas guides formed by the above method are fitted to each other, for example, instead of the individual exhaust gas guides first assembled into each of the two shells, each half of the interior is separately connected to each other, and then all Two halves of the exhaust gas guide are connected to each other at the same time. In this way it can be ensured that the cross sections of the exhaust gas guides coincide with each other in the sliding fitting area. This avoids problems when joining the exhaust gas guides together, and it can be ensured that the individual exhaust gas guides are disposed without problems with each other in operation.

After all of the shells fitted together are connected by general reforming of the rim, in particular by folding, the shells of each exhaust gas guide are latched to each other by spot welding, if necessary. Next, the inside is inserted into the outer shell and they are connected to each other in a gas tight manner by welding.

The inner shell is preferably made of sheet metal, in particular by deep drawing. It is desirable to cast the beads to increase the stiffness of the shell. In particular, two half shells are produced per exhaust gas guide and then connected to each other simultaneously with the other half shells.

Non-limiting embodiments of the invention are shown in the drawings and described below.

The illustrated air gap manifold is manufactured in an airtight manner by enclosing an interior 1 having a plurality of exhaust gas guides 2, 3, 4 fitted together with each other in a sliding fit manner, and surrounding the interior 1 in a spaced apart state. It includes the outer (5) being. This forms an air gap 6 between the inner 1 and the outer 5 and insulates the heat of the exhaust manifold.

The exhaust gas guides 2, 3, 4 are made of two half shells 2a and 2b, 3a and 3b, 4a and 4b, which are connected to each other on the rim side, respectively. The connection is a fold connection as shown in FIG. For this purpose the rim of one half shell 3a is curved around the rim of the other half shell 3b. The folds 7 are then arranged obliquely as shown by the dashed lines to increase the strength of the connections.

The exhaust gas guides 2, 3, 4 are fitted to each other in a sliding fitting manner as described above. For this purpose, the fold 7 ends at each end 2 ', 3' of the exhaust gas guides 2, 3 located in front of the end of each exhaust gas guide 2, 3. This forms a fold-free region 8 in which the combined ends 3 ", 4" of each adjacent exhaust gas guide 2, 3 are arranged in a sliding fit manner.

The other end 2 "of the exhaust gas guide 2 together with the outer shell 5 is connected in a hermetic manner to the first inlet flange 9. The second inlet flange 10 is the outer shell 5 and the exhaust It is hermetically connected to the end 11 ′ of the side branch 11 of the gas guide 3. Finally, the third and fourth inlet flanges 12, 13 are connected to the outer shell 5, and one rigid It is hermetically connected to the sleeves 14 and 14 ', respectively, and the sleeve 14 is positioned in a sliding fit within the side branch 15 of the exhaust gas guide 4 and also the sleeve 14' is also exhaust gas. It is positioned in a sliding fit manner in the second end 4 ′ of the guide 4.

The exhaust gas guide 4 has a second branch 16 into which an additional sleeve 17 is inserted therein in a sliding fit manner. The sleeve 17 is connected in an airtight manner to the outlet flange 18 with an outer 5. A continuous tube of a typical exhaust gas system may be connected to the outlet flange 18. Thus, the inlet flanges 9, 10, 12, 13 can be connected to the exhaust gas outlet of the internal combustion engine.

The outer 5 also has two half shells 5a, 5b. However, the separation surface I of the half shells 5a and 5b is approximately 90 degrees from the separation surface II of the half shells 2a, 2b, 3a, 3b, 4a and 4b of the interior 1, at an angle, and a flange. It extends approximately parallel to the (9, 10, 12, 13) plane.

The illustrated air gap manifold is made substantially so that both the first half shells 2a, 2b, 3a, 3b, 4a, 4b of the inner 1 and the half shells 5a, 5b of the outer 5 are manufactured. . Bead 19 can be inserted into the half shell in this process. Next, each one of the half shells 2a, 3a, 4a in the interior 1 is sandwiched with each other according to the desired sliding fitting arrangement. As a result, the half shells 2b, 3b, and 4b of the interior 1 are fitted to each other. After inserting the sleeves 14, 14 ′, the half shells 2a, 3a, 4a and 2b, 3b, 4b fitted together are inserted into the rebuild tool. Next, all the half shells 2a, 2b, 3a, 3b, 4a, 4b coupled to each other are connected to each other by folding on the rim side. If necessary, each of the half shells 2a, 2b, 3a, 3b, 4a, 4b in the interior 1 is latched to each other by separate spot welding. In this process, laser or MAG welding techniques are used to prevent weld splash damage.

The interior is thus completed, removed from the reshaping tool and inserted into the bottom shell 5b of the exterior 5. The interior 1 is connected in an airtight manner to the inlet flanges 9, 10, 12, 13 together with the outer bottom shell, in particular by welding. The sleeve 17 is hermetically welded to the outlet flange 18 together with the top shell 5a of the exterior 5. The upper shell 5a of the outer 5 is then placed on the lower shell 5b and the overlapping area is welded in an airtight manner. The two half shells 5a, 5b of the outer part 5 can be connected to each other by a general welding method because the weld seam is on the outside.

The exhaust gas guides 2, 3, and 4 can be connected in a sliding fit manner by the above-described manufacturing method, and the exhaust gas guides 2, 3, and 4 are different in structure from the half shell but are fitted very tightly. Can lose. Since the exhaust gas guides 2, 3 and 4 do not need to be connected to each other in a folded state, the ends 2 ', 3 "and 3' and 4" of the associated exhaust gas guides 2, 3 and 4 are not connected. Problems due to non-uniform rounding or cross section also do not occur.

Due to the illustration of the other aspects and the structure of the interior connected in a sliding fit manner, the exhaust gas guides 2, 3, 4 of the interior 1 are substantially free of thermal expansion, in particular the exterior 5, in a known manner. More heating of the interior 1 to) can lead to greater thermal expansion. On the other hand, the outer 5 ensures high airtightness of the air gap manifold. In this way, suitable air gap manifolds can be manufactured at relatively low cost.

1 is a plan view of an air gap manifold according to the present invention with the upper outer shell removed.

2 is a cross-sectional view of the air gap manifold according to the present invention, taken along line A-A of FIG.

3 is a cross-sectional view of the air gap manifold according to the present invention taken along line C-C of FIG. 2.

4 is an enlarged view of detail B of FIG. 3.

Claims (15)

In an air gap manifold that connects an exhaust gas outlet of an internal combustion engine, in particular an automobile engine, to an exhaust gas inlet of an exhaust gas system, The exhaust gas system comprises an interior 1 having a plurality of exhaust gas guides 2, 3, 4 connected to each other in a sliding fit manner, an exterior 5 surrounding the interior 1 and manufactured in a hermetic manner. And an air gap 6 between the inner 1 and the outer 5, At least some of the exhaust gas guides 2, 3, 4 of the interior 1 are shells 2a, 2b, 3a, 3b, 4a, 4b connected to each other by normal reshaping, in particular folding, in the rim. ) Formed Air gap manifold. The method of claim 1, Air gap manifold, characterized in that the outer part (5) also consists of shells (5a, 5b). The method according to claim 1 or 2, The air gap manifold, characterized in that the shells 2a, 2b, 3a, 3b, 4a, 4b of the interior 1 and / or the shells 5a, 5b of the exterior 5 are made of sheet metal. Fold. The method according to any one of claims 1 to 3, The shells 2a, 2b, 3a, 3b, 4a, 4b of the inside 1 and / or the shells 5a, 5b of the outside 5 have beads 19. Air gap manifold. The method according to claim 3 or 4, Air gap manifold, characterized in that the shell (5a, 5b) of the outer (5) is welded to each other. The method according to any one of claims 1 to 5, The shell (2a, 2b, 3a, 3b, 4a, 4b) of the interior (1) is in particular latched on each other by separate spot welding. The method according to any one of claims 1 to 6, Air gap manifold, characterized in that the outer part (5) consists of two half shells (5a, 5b). The method according to any one of claims 1 to 7, Air gap manifold, characterized in that the shell (2a, 2b, 3a, 3b, 4a, 4b) in the interior (1) is a half shell. The method of claim 8, Air gap manifold, characterized in that the separating surface (I) of the outer shell (5) and the separating surface (II) of the inner shell (1) are approximately perpendicular to each other. The method according to any one of claims 1 to 9, An air gap manifold, which is used for an internal combustion engine having a turbocharger. In the method of manufacturing the air gap manifold according to claim 1, The shells 2a, 3a, 4a of the interior 1 which respectively form part of the exhaust gas guides 2, 3, 4 are first connected to each other according to the sliding fitting method, and then the exhaust gas guides 2, 3 And connecting the shells 2b, 3b and 4b, which respectively form the other part of 4), to each other according to a sliding fit manner, This allows the combined shells 2a, 2b, 3a, 3b, 4a, 4b of the exhaust gas guides 2, 3, 4 to be reshaped, in particular folded and joined to each other in a rim. Method of manufacturing air gap manifolds. The method of claim 11, And said shell (2a, 2b, 3a, 3b, 4a, 4b) in said interior (1) is latched to each other by separate spot welding. The method according to claim 11 or 12, wherein The shell (5a, 5b) of the outer (5) is welded to each other in an airtight manner, characterized in that the air gap manifold manufacturing method. The method according to any one of claims 11 to 13, The air gap manifold, characterized in that the shells 2a, 2b, 3a, 3b, 4a, 4b of the interior 1 and / or the shells 5a, 5b of the exterior 5 are made of sheet metal. Method of manufacturing folds. The method according to any one of claims 11 to 14, Air gap manifolds, characterized in that beads are provided in the shells 2a, 2b, 3a, 3b, 4a, 4b of the interior 1 and / or the shells 5a, 5b of the exterior 5. Manufacturing method.