EP2937539B1 - Exhaust manifold - Google Patents

Description

The invention relates to an exhaust manifold for attachment to a cylinder head of an internal combustion engine according to the features in the preamble of claim 1.

An exhaust manifold is a component of an exhaust system of internal combustion engines, in particular of internal combustion engines in motor vehicles. Attached directly to the cylinder head of the internal combustion engine, the exhaust manifold serves to merge the exiting from the individual cylinders exhaust and forward an exhaust gas outlet. An exhaust manifold is therefore often referred to as exhaust manifold.

An air gap insulated exhaust manifold counts by the US 5,729,975 A to the state of the art. This has an inner tube system and a surrounding the inner tube system at a distance outer shell and an inlet flange and an outlet flange. Likewise, the DE 101 02 637 A1 an exhaust manifold to Exhaust system. The exhaust manifold has an inner tube system, there formed as an inner shell, which is surrounded by an outer shell, so that between the inner shell and the outer shell, an air gap is formed. On the exhaust gas inlet side inlet flanges are provided with inlet openings. At a middle section of the exhaust manifold, the exhaust gases flowing in via the inlet flanges are brought together on a common outlet flange.

By the EP 2 207 950 B1 an air gap insulated exhaust manifold is known, which consists essentially of three components: an outer shell, an inner shell and a fixable on the cylinder head of the engine flange. The outer shell and the inner shell are each hood-shaped and each have a circumferential collar, wherein the outer shell collar is connected to the flange and the inner shell collar is clamped between outer shell collar and flange. To effect this clamping a plurality of knob-shaped or wave-shaped bulges are formed on the inner shell collar, which are punctiform supported against the outer shell collar and / or the flange.

The EP 1 206 631 B1 discloses an exhaust manifold having an exhaust manifold housing for receiving exhaust gas from the cylinder head having a sealing means disposed between the exhaust manifold housing and the cylinder head. The exhaust gas collecting housing is provided with recesses such that it can be connected directly to the cylinder head via fastening means, wherein movements caused by the action of heat between the exhaust gas collecting housing and the cylinder head are possible. Elaborate here is the additional sealing device between the outer system and exhaust manifold and the determination of the fastener.

Furthermore counts by the DE 103 59 073 A1 an exhaust manifold to the prior art, which is composed of an outer body and a two-part constructed inner body. Here, the two-piece inner body is attached to a flange such that parts of the inner body in a flange of the flange, which serves as a fixed bearing, are added.

The EP 1 389 267 B1 shows an air gap insulated exhaust manifold, which due to the thin wall of the gas guide channel and the air gap between the exhaust gas collecting housing and the gas guide channel the exhaust gas draws relatively little heat. For this purpose, the exhaust manifold is composed of a plurality of individual components, which should represent an improved thermal decoupling.

The DE 103 59 062 A1 further shows a bonnet manifold having a manifold and at least one hood. The manifold is composed in two parts of two half-shells, which are completely enclosed by the hood, with the use of at least two soft gaskets, the functionality of the component is to be maintained even at high operating temperatures.

The thin-walled exhaust manifold has the advantage that the thermal mass and thus the response of a downstream catalytic converter after cold start is improved. Furthermore, air gap-insulated exhaust manifolds have the advantage that the heat loss of the exhaust gas on the way to the catalyst can be reduced by the insulating effect of the air gap, whereby a rapid heating or achievement of the operating temperature of the catalyst is effected after the engine cold start.

In general, the aim is to simplify the known types of exhaust manifolds structurally. A particular challenge in this case are the high temperatures and temperature fluctuations, which are exposed to the component components of an exhaust manifold during operation and the resulting mechanical loads and the associated demands on the tightness and durability.

The invention is based on the object of the prior art to improve an exhaust manifold with a simple structure functionally.

The solution of this problem consists according to the invention in an exhaust manifold for an exhaust system of an internal combustion engine according to the features in claim 1.

Advantageous embodiments and further developments of the exhaust manifold according to the invention are the subject of the dependent claims 2 to 9.

The exhaust manifold according to the invention has a housing with a plurality of inlet openings and an outlet opening. The intake ports correspond to the cylinder outlets of the cylinder head of the internal combustion engine. The housing comprises an inner shell and an outer shell, wherein the outer shell surrounds the inner shell to form a gap. The gap may be a clean air gap or be filled with an insulating material, in particular a Dämmmattenkörper, filled gap. On the side facing the cylinder head side of the inner shell, so the cylinder head side, the inner shell is associated with a baffle. In the guide plate, the inlet openings are provided. On the circumference, at least on a part of the circumference of the inlet openings, guide elements are formed on the guide plate.

The guide elements are designed so that the exhaust gas is directed or passed through the inner shell with low flow resistance. The targeted exhaust system causes a reduction of the exhaust backpressure. The exhaust stream coming from the cylinder head is directed into the inner shell, deflected and collected into the exhaust port.

The outer shell has on its cylinder head side edge on a converted to the outside flange. With the flange, the outer shell rests against the baffle and is joined to the baffle cohesively gas-tight. On the baffle opposite outside of the flange, a collar body is arranged. The collar body is externally guided over or around the outer shell and surrounds this. The collar body rests against the flange, in particular circumferentially and over the entire surface. The collar body has a greater strength than the baffle and also as the flange of the outer shell together. Preferably, the wall thickness of the collar body is greater than the wall thickness of the baffle and the wall thickness of the flange of the outer shell. In an advantageous practical embodiment, the baffle has a wall thickness of 1.2 mm to 1.5 mm. The inner shell has a wall thickness up to 2.0 mm, in particular up to 1.5 mm. The outer shell has a wall thickness of 1.5 mm to 2.0 mm. Also, the flange of the outer shell is 1.5 mm to 2.0 mm thick.

The collar body has a wall thickness of 5 mm and is thus thicker than the flange of the outer shell and the baffle together.

Cylinder head side, the tightness of the housing of the exhaust manifold is effected by the addition of baffle and outer shell. These are materially joined gas-tight together. In particular, the flange of the outer shell and the baffle are welded together. On the outside of the collar body is arranged. The collar body can be loosely placed and fixed by means of fasteners. It is also possible that the collar body is fixed on the outside of the flange, especially stapled by welding.

The inner shell is arranged floating overall in the outer shell. The inner shell is located on the cylinder head side on the baffle.

Particularly advantageously, the collar body is made in one piece and circumferentially along the flange. The collar body thus has an annular shape and is guided with its opening over the outer shell of the housing and abuts against the outside of the flange.

In the collar body, the flange and the baffle mutually corresponding mounting holes are provided. By means of fastening means, in particular bolts, which are guided through the mounting holes, the exhaust manifold is bolted to the cylinder head of an internal combustion engine. This can be done by incorporating a seal between baffle and cylinder head of the engine.

Particularly advantageously, an insulating material is incorporated in the gap between the inner shell and outer shell. In particular, the insulating material is a fiber material. Preferably, the insulating material is used in the form of a preformed cup-shaped Dämmmattenkörpers which is installed compressed between the inner shell and the outer shell. The Dämmmattenkörper serves or acts as a spring or spring unit and presses the inner shell against the baffle. Here, the Dämmmattenkörper supported on the outer shell.

The guide elements are uniform in material issued or molded from the baffle. This can be done in an advantageous manner in the production of the inlet openings. Here, the guide members are formed in the manner of a passage from the baffle.

The outer shell has an outlet. At the outlet of the outer shell, an outlet flange gas-tight material-joined, preferably welded. About the outlet flange of the exhaust manifold is connected to downstream components of the exhaust system, such as a turbocharger or the housing of a turbocharger or an exhaust pipe.

Another aspect of the invention is that the inner shell has an outlet. The outlet of the inner shell protrudes at least a piece into the outlet of the outer shell. Preferably, the outlet port of the inner shell lies with its protruding into the outlet nozzle length section inside the outlet of the outer shell. Of course, an embodiment is possible in which the outlet of the inner shell is not applied inside the outlet of the outer shell.

The outlet of the inner shell is also arranged to move freely in the outlet of the outer shell. About the arranged between the outer shell and inner shell insulating material, the inner shell is held in position. Length or shape changes as a result of operating temperatures or - changes are compensated in the system.

The exhaust manifold according to the invention is functionally improved, simple in construction, rational and also advantageous assembly technology. The exhaust manifold is also characterized by its lightweight construction. The assembly of the exhaust manifold on the cylinder head of the internal combustion engine via the mounting system, formed from the outer edge region of the baffle, the flange of the outer shell and the collar body. The collar body provides the essential part of the necessary mass for a stable mounting of the exhaust manifold on the cylinder head. In addition, the tightness of the system is ensured in a reliable and simple manner, without that it requires complex sealing means between the housing and the baffle.

Figur 1

einen erfindungsgemäßen Abgaskrümmer in einer Seitenansicht;

Figur 2

den Abgaskrümmer gemäß der Darstellung der Figur 1 in einem Längsschnitt;

Figur 3

den Abgaskrümmer mit einer explosionsartig auseinandergezogenen Darstellung seiner Bauteile;

Figur 4

einen Querschnitt durch den Abgaskrümmer;

Figur 5

eine Ansicht auf den Abgaskrümmer von unten;

Figur 6

das Leitblech eines Abgaskrümmers in einer perspektivischen Darstellung und

Figur 7

einen Querschnitt durch den Abgaskrümmer im Bereich des Austrittsflanschs.

The invention is explained in more detail with reference to an embodiment shown in the drawings. Show it:

FIG. 1

an exhaust manifold according to the invention in a side view;

FIG. 2

the exhaust manifold according to the illustration of FIG. 1 in a longitudinal section;

FIG. 3

the exhaust manifold with an exploded view of its components;

FIG. 4

a cross section through the exhaust manifold;

FIG. 5

a view of the exhaust manifold from below;

FIG. 6

the baffle of an exhaust manifold in a perspective view and

FIG. 7

a cross section through the exhaust manifold in the region of the outlet flange.

Based on the representations of FIGS. 1 to 7 an exhaust manifold 1 according to the invention for an exhaust system of an internal combustion engine is described. The exhaust manifold 1 is mounted or mounted on a cylinder head, not shown here, of an internal combustion engine in a motor vehicle.

The exhaust manifold 1 comprises a housing 2 which has a plurality of inlet openings 3, 4, 5 and an outlet opening 6. The housing 2 consists of an inner shell 7 and an outer shell 8. The outer shell 8 surrounds the inner shell 7 to form a gap 9. Cylinder head side of the inner shell 7, a baffle 10 is arranged. On the baffle 10, the inlet openings 3, 4, 5 are formed. Circumferential side of the inlet openings 3, 4, 5 are guide members 11, 12, 13 issued in the form of exhibitions from the baffle 10 inwardly into the housing 2. The guide members 11, 12, 13 perform this from the Zylinderauslässen Coming via the inlet openings 3, 4, 5 incoming exhaust gas in the interior 14 of the inner shell 7 together and direct the Abgasström directed in the direction of the outlet opening. 6

The outer shell 8 has on its cylinder-head-side edge 15 to a peripheral circumscribed flange 16. The flange 16 abuts against the baffle 10 and is connected to the guide plate 10 peripherally cohesively via a weld 17 gas-tight. In particular, the joining takes place thermally by means of laser welding.

On the baffle 10 opposite outer side 18 of the flange 16, a collar body 19 is arranged. The collar body 19 is made in one piece and runs closed along the flange 16 around the outer shell 8 around. On the flange 16, the collar body 19 may be fixed, in particular be stapled by welding. It is also possible a continuous continuous welding between collar body 19 and flange 16th

In gap 9 between inner shell 7 and outer shell 8, an insulating material 20 is incorporated. The insulating material 20 is designed as a prefabricated cup-shaped Dämmmattenkörper 21. The insulating mat body 21 has a configuration adapted to the inner contour or outer contour of the outer shell 8 or inner shell 7. The insulating material 20 has both sound insulating and thermal insulating properties.

The guide members 11, 12, 13 are of the same material from the baffle 10 issued in one piece. Due to the contour of the guide elements 11, 12, 13, the inlet openings 3, 4, 5 taper from the baffle 10 to the end of the Leitorgange 11, 12, 13 out. This has a positive influence on the flow conditions in the inner shell 7 and the directed exhaust gas flow during the deflection from the inlet openings 3, 4, 5 to the outlet opening 6.

The FIG. 4 illustrates that the inner shell 7 has on its cylinder head side edge 22 an outwardly converted collar 23. With the collar 23, the inner shell 7 is on the guide plate 10. This is also in the FIG. 7 clear. It can further be seen that the guide elements 11, 12, 13 protrude inwards into the inner shell 7. In the FIG. 4 one recognizes further that the guide member 13, the inner shell. 7 contacted inside, so that here is a positional orientation of the inner shell 7 by the guide member 13.

The outer shell 8 has an outlet nozzle 24. The outlet opening 6 is arranged in the outlet connection 24 of the outer shell 8. At the outlet port 24, an outlet flange 25 is gas-tight cohesively joined, in particular tightly welded. The outlet flange 25 serves to connect the exhaust manifold 1 with downstream component components of the exhaust system.

Especially in the FIG. 7 it can be seen that the inner shell 7 has an outlet 26. The outlet port 26 of the inner shell 7 is located inside the outlet port 24 of the outer shell 8. In particular, the outlet port 26 of the inner shell 7 is tight against the inner periphery of the outlet port 24 of the outer shell 8, but movable, so that it can move along the inner circumference.

In the collar body 19, the flange 16 and the baffle 10 mutually corresponding mounting holes 27 are provided. About fastening means in the form of bolts, which are guided through the mounting holes 27 and screwed into threaded holes in the cylinder head, the exhaust manifold 1 can be set and braced on the cylinder head of an internal combustion engine.

The exhaust manifold 1 is characterized by its low weight due to its lightweight construction. The outer shell 8 and the baffle 10 form the outer system, which is gas-tight connected by welding. By a steering or directed guidance of the exhaust gas flow from the cylinder head into the inner shell 7 by means of the guide members 11, 12, 13 in the guide plate 10, a low back pressure is generated or the exhaust gas back pressure is reduced.

Reference numerals:

• 1 - Exhaust manifold
• 2 - housing
• 3 - inlet opening
• 4 - inlet opening
• 5 - inlet opening
• 6 - outlet opening
• 7 - inner shell
• 8 - outer shell
• 9 - gap
• 10- baffle
• 11 - Guide organ
• 12-Leitorgan
• 13- guide organ
• 14- interior of 7
• 15- edge of 8
• 16- flange
• 17- weld
• 18- outside of 16
• 19- Bund body
• 20 - Insulating material
• 21 - insulating mat body
• 22 - edge of 7
• 23 - collar
• 24 - outlet of 8
• 25 - outlet flange
• 26 - outlet nozzle of 7
• 27 - Mounting hole

Claims (9)

1. An exhaust manifold for installation onto a cylinder head of an internal combustion engine, the exhaust manifold comprising a housing (2) having multiple inlet openings (3, 4, 5) and an outlet opening (6), the housing having an inner shell (7) and an outer shell (8), the inner shell (7) being floatingly arranged in the outer shell (8) and the outer shell (8) surrounding the inner shell (7) so as to define a gap (9) therebetween, and a guide plate (10) associated with the inner shell (7) at a side of the cylinder head, the guide plate configured to form the inlet openings (3, 4, 5), wherein guide members (11, 12, 13) are arranged on the guide plate (10) at a respective circumference of the inlet openings (3, 4, 5), and the outer shell (8) has a cylinder-head-proximal marginal region (15) formed with an outwardly bent flange (16), the flange (16) being configured to rest upon the guide plate (10), characterized in that the flange (16) is joined in a gastight manner to the guide plate (10) by a material joint, and the inner shell (7) is configured to rest upon the guide plate (10) at a side of the cylinder head, and a collar (19) is arranged on an outer side (18) of the flange (16) opposite of the guide plate (10).
2. The exhaust manifold according to claim 1, characterized in that the flange (16) of the outer shell (8) and the guide plate (10) are welded together.
3. The exhaust manifold according to claim 1 or 2, characterized in that the collar (19) is secured to the flange (16).
4. The exhaust manifold according to at least one of claims 1 to 3, characterized in that the collar (19) is formed in one piece and extends about the flange (16).
5. The exhaust manifold according to at least one of claims 1 to 4, characterized in that the collar (19), the flange (16) and the guide plate (10) have complementing mounting holes (27).
6. The exhaust manifold according to at least one of claims 1 to 4, characterized in that an insulation material (20) is received in the gap (9) between the inner shell (7) and the outer shell (8).
7. The exhaust manifold according to at least one of claims 1 to 6, characterized in that the guide members (11, 12, 13) are integrally formed with the guide plate (10) so as to be of the same material.
8. The exhaust manifold according to at least one of claims 1 to 7, characterized in that the outer shell (8) has an outlet neck (24), and an outlet flange (25) is joined by a material joint with the outlet neck (24) in a gastight manner.
9. The exhaust manifold according to claim 8, characterized in that the inner shell (7) has an outlet neck (26), the outlet neck (26) of the inner shell (7) being configured to project into the outlet neck (24) of the outer shell (8).

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