DE102008047535B4 - Exhaust gas cooling module for an internal combustion engine - Google Patents

Abstract

An exhaust gas cooling module for an internal combustion engine with a support part, via which the exhaust gas cooling module is attached to the cylinder head of the internal combustion engine, an exhaust gas cooler, which is attached to the support member, an exhaust gas control device which is attached to the support member and controls the exhaust gas flow in the exhaust gas cooling module and a thermostatic valve, which Coolant flow from the cylinder head into the exhaust gas cooling module controls, characterized in that the carrier part (2) has four flange levels (4, 6, 8, 10), wherein the first flange (4) is fixed to the cylinder head, the thermostatic valve (24) on the second flanged plane (6) is fastened, the exhaust gas control device (34) is fastened to the third flanged plane (8) and an exhaust gas flowed through housing (64) of the exhaust gas cooler (56) via at least one weld thermally coupled to the fourth flange plane (10) is attached wherein the exhaust gas control device (34) has an exhaust gas inlet opening (38), two Exhaust gas quantity control devices and two Abgasauslassöffnungen (40, 42), of which the first exhaust gas quantity control device controls the exhaust gas flow to the exhaust gas cooler (56) and the second exhaust gas quantity control device controls the exhaust gas flow to a bypass channel (54).

Description

The invention relates to an exhaust gas cooling module for an internal combustion engine with a support part, via which the exhaust gas cooling module is attached to the cylinder head of the internal combustion engine, an exhaust gas cooler, which is attached to the support member, an exhaust gas control device which is attached to the support member and controls the exhaust gas flow in the exhaust gas cooling module and a Thermostat valve, which controls the flow of coolant from the cylinder head into the exhaust gas cooling module.

The use of exhaust gas cooling devices in internal combustion engines is known and serves to reduce pollutant emissions. For this purpose, exhaust gas coolers of various types are used, with the cooling carrier present in the internal combustion engine cooling liquid compared to the air as a cooling carrier has proven to be advantageous because significantly better cooler efficiencies can be achieved. On the other hand, additional lines are required in steadily decreasing available space for guiding the coolant. Furthermore, the building demand for accommodating the exhaust gas cooler, in particular when using additional bypass ducts for faster heating of the internal combustion engine, and the associated exhaust gas recirculation lines.

Accordingly, exhaust gas cooling modules have been created in recent times, by means of which the number of lines for coolant and exhaust gas can be reduced. In addition, the required space is to be reduced by these modules, a high integration into the internal combustion engine can be achieved without having to accept losses in efficiency.

So will in the DE 10 2005 031 300 A1 an internal combustion engine with cooling system and exhaust gas recirculation system presented, in which the exhaust gas heat exchanger is attached directly to a coolant collection bar, which in turn is attached to the cylinder head cover. This eliminates coolant lines.

A with respect to the required lines and the space used additionally optimized exhaust gas cooling module of an internal combustion engine is in the EP 1 643 097 A1 described. This exhaust gas cooling module has a carrier plate, which is fastened to the cylinder head and formed in the exhaust gas recirculation lines. The module has two functional units, a first unit of which has an exhaust gas heat exchanger with an exhaust gas quantity regulating device arranged thereon and parts of the cooling circuit with a cooling water outlet housing and a thermostatic valve. The second functional unit is essentially formed by the support plate, on one side of which the first functional unit is fastened via a screw connection with the interposition of a seal and whose opposite side is thermally insulated on the cylinder block.

In addition is from the EP 1 793 115 A1 an exhaust gas cooling module with a support member with four flange levels known, with a first flange for attachment to the cylinder head, a second for mounting a radiator, a third for mounting a thermostatic valve and a fourth for mounting an exhaust gas recirculation valve.

These embodiments have the disadvantage that the hot exhaust gas from the internal combustion engine heats the carrier plate. Accordingly, a heat dissipation takes place only via the coolant in the exhaust gas cooler. An additional heat dissipation from the hot radiator housing is not possible due to the necessary intermediate layer of seals to the support plate. Furthermore, the accessibility of the individual components of the former module by the arrangement to each other is significantly limited. In particular, an exchange of individual components is thus made more difficult. A regulation of the temperature of the exhaust gas is also not possible.

It is therefore an object of the invention to provide an exhaust gas cooling module, which achieves a higher cooling performance compared to the known designs and additionally improves the integration of the components and their accessibility.

This object is achieved by the characterizing part of the main claim. The support member has four flange planes, wherein the first flange plane is fixed to the cylinder head, the thermostat valve is attached to the second flange plane, the exhaust control device is attached to the third flange plane and an exhaust gas flowed through the housing of the exhaust gas cooler via a weld thermally coupled to the fourth flange plane is. By the weld, a thermal coupling of the cooler housing is achieved to the support member, whereby an additional heat dissipation from the radiator via the metallic connection to the housing and thus the cooling capacity of the exhaust gas cooling module is increased. Furthermore, the four different flange levels significantly simplify the assembly of the exhaust gas cooling module and improve the accessibility of the individual components. The exhaust gas control device has an exhaust gas inlet opening, two exhaust gas quantity regulating devices and two exhaust gas outlet openings. The first exhaust gas quantity regulating device preferably controls the exhaust gas flow to the exhaust gas cooler, while the second exhaust gas quantity regulating device controls the exhaust gas flow to a bypass channel. A Such an arrangement allows independent regulation of the two exhaust gas streams either into the exhaust gas conduit leading to the exhaust gas cooler or into the bypass conduit bypassing the cooler. Thus, the functions of an exhaust gas recirculation valve and a bypass flap are combined in the housing, whereby the required space is reduced. Additional space in the region of the exhaust gas cooler for accommodating a bypass flap is thus not required in such an embodiment.

In a further embodiment, in the support part is a coolant channel with a coolant inlet, which is fluidly connected to a coolant outlet opening of the cylinder head, with a first coolant outlet, which is fluidly connected to a coolant pipe, which leads to a main radiator of the internal combustion engine and with a second coolant outlet, the is fluidly connected to a coolant jacket of the exhaust gas cooler formed. As a result, a distribution of the coolant to the exhaust gas cooler, and the main radiator of the internal combustion engine takes place within a single component, which in turn saves space. An additional coolant outlet for connection to the passenger heater may also be provided.

Preferably, an exhaust gas inlet channel, an exhaust gas channel and a bypass channel are formed in the carrier part, whereby the laying of individual lines for the fluidic connection of the individual components can be dispensed with.

In a preferred embodiment, the support member has a first exhaust inlet fluidly connected to an exhaust gas outlet opening of the cylinder head and a first exhaust gas outlet fluidly connected to the exhaust gas inlet opening of the exhaust gas control device having second and third exhaust gas inlets fluidly connected to the two exhaust gas outlet openings of the exhaust gas control device and a second exhaust outlet fluidly connected to an exhaust gas inlet opening of the exhaust gas cooler and a fourth exhaust gas inlet fluidly connected to an exhaust gas outlet opening of the exhaust gas cooler and a third exhaust gas outlet connected to an exhaust gas recirculation line of the internal combustion engine. In this way, the modular construction with the four flange levels is realized and reinforced by the arrangement of the exhaust ducts in the support part, the cooling effect through the heat-conducting surfaces.

Advantageously, between the third exhaust gas inlet and the third exhaust gas outlet, a fluidic connection forming the bypass passage, between the second exhaust gas inlet and the second exhaust gas outlet, a fluidic connection forming an exhaust passage and between the first exhaust gas inlet and the first exhaust gas outlet an exhaust gas inlet channel is formed. This design enables a high degree of integration of the individual components.

The third exhaust gas outlet preferably serves both as an outlet of the bypass duct and as an outlet for the exhaust gas cooled in the exhaust gas cooler, as a result of which a duct part is used twice and thus space-saving advantages arise.

In a preferred embodiment, the exhaust gas quantity control devices can be driven via a common setting unit, as a result of which components are saved and, in turn, the required installation space is reduced.

Accordingly, an exhaust gas cooling module is created, which combines a variety of functions in itself, is very small and easy to install, while achieving significantly increased radiator efficiencies.

An embodiment is shown in the drawings and will be described below.

1 shows a plan view of an inventive exhaust gas cooling module.

2 shows one to 1 corresponding plan view of the exhaust gas cooling module according to the invention in a sectional view

3 again shows a to 1 corresponding plan view of the inventive exhaust gas cooling module in a sectional view with a relative to 2 deeper cutting plane.

4 shows a front view of the exhaust gas cooling module according to the invention 1 in a cutaway view.

The exhaust gas cooling module shown in the figures consists of a support member 2 , which has four flange levels 4 . 6 . 8th . 10 having, at different ends of the support member 2 are designed for attachment of other components.

The first flange level 4 is to a cylinder head, not shown, of an internal combustion engine via four screws, which by on the support part 2 trained dome 12 with through holes 14 be plugged, fastened. In the carrier part 2 is an exhaust gas inlet duct 16 with an exhaust inlet 18 and a coolant channel 20 with a coolant inlet 22 formed, which correspond with appropriately designed exhaust or Kühlmittelauslassöffnungen of the cylinder head, so that an exhaust stream or a Coolant flow from the cylinder head into the carrier part 2 can flow in, in particular from 2 evident.

As in the 1 and 4 is visible at the to the coolant inlet 22 the first flange level 4 opposite flange plane 6 in the area of a first coolant outlet 23 the carrier part 2 a thermostatic valve 24 attached, via which a coolant flow through the coolant channel 20 across the carrier part 2 to one also at the flange level 6 attached coolant pipe 26 , which leads to a main radiator of the cooling circuit of the internal combustion engine, is blocked or released depending on the coolant temperature. To check the correct function of the thermostatic valve 24 is on the carrier part 2 in the area of the thermostatic valve 24 in addition a temperature sensor 28 arranged. On the coolant pipe 26 are two breather ports 30 formed, can be removed from the system via the resulting gases in the coolant flow.

Out 3 and 4 becomes the third flange level 8th seen at a first head end of the support member 2 substantially perpendicular to the first flange plane 2 and the second flange level 4 is arranged. At the third flange level 8th will turn over screws 32 an exhaust gas control device 34 attached. This consists of a housing 36 with an exhaust gas inlet opening 38 that with a first exhaust outlet 39 the carrier plate 2 fluidly connected, and two exhaust gas outlet openings 40 . 42 being between the exhaust gas inlet opening 38 and the two Abgasauslassöffnungen 40 . 42 each a valve seat is arranged, which is dominated by a respective exhaust gas quantity control device, not shown in the figures.

The two exhaust gas quantity control devices are via a common actuator 44 but operated separately. Thus, the exhaust gas flow is controlled from the exhaust gas inlet opening 38 either via the first exhaust outlet opening 40 to a second exhaust inlet 46 the carrier plate 2 via the second exhaust gas outlet openings 42 the exhaust control device 34 to a third exhaust inlet 48 the carrier plate 2 ,

During this second exhaust inlet 46 in an exhaust duct 50 the carrier part 2 and from here to a second exhaust outlet 52 leads, is via the third exhaust inlet 48 directed exhaust gas flow in a likewise in the carrier part 2 trained bypass channel 54 guided over the one at the fourth flange level 10 attached exhaust gas cooler 56 can be bypassed.

This fourth flange level 10 is essentially at the third flange level 8th opposite head of the support member 2 arranged and in particular in 3 to recognize. Accordingly, the second exhaust outlet 52 fluidic with an exhaust gas inlet opening 58 of the exhaust gas cooler 56 connected and an exhaust outlet 60 of the exhaust gas cooler 56 with a fourth exhaust inlet 62 the carrier plate 2 connected.

The exhaust gas cooler 56 consists of an exhaust gas flowed through the inner housing 64 and a this case 64 with the exception of the head end, where the exhaust inlet opening 58 and the exhaust outlet opening 60 are formed, surrounding outer housing 66 , Accordingly, it is a U-shaped exhaust gas flowed through exhaust gas cooler 56 in which between the inner housing 64 and the outer casing 66 a coolant jacket 68 is trained. This is with a first in the carrier part 2 trained coolant channel 69 , which is perpendicular to the coolant channel 20 branches off, in the carrier part 2 extends and at a second coolant outlet 70 ends, via an between inner casing 64 and outer casing 66 formed coolant inlet opening 72 fluidly connected. In addition to the inner housing 64 in the exhaust gas flowed through channel 74 of the exhaust gas cooler 56 protruding ribs 76 this has to realize the U-shaped flow through a middle wall 78 on that before the end of the exhaust gas cooler 56 ends and on its front a partition 80 essentially extends the exhaust duct 50 from the bypass channel 54 in the carrier part 2 separates.

According to the invention, the inner housing 64 of the exhaust gas cooler 56 at the fourth flange level 10 with the carrier part 2 , the fourth exhaust inlet 62 and the second exhaust outlet 52 surrounding welded, so that a thermal coupling between the support part 2 and the exhaust gas cooler 56 arises. Accordingly, heat from the exhaust gas cooler 56 or the exhaust gas flow into the carrier part 2 passed over the large surface in addition heat dissipation surface is discharged to the surrounding air. An additional cooling effect is obtained in that also in the carrier part 2 Coolant channels are formed and that by this cooling water when using a good conductive magnesium or aluminum die-casting for the production of the support member 2 this serves as a precooler with a large heat conduction surface. Thus, in comparison to the effect of the exhaust gas cooler alone, a more than 20% higher cooling efficiency of the exhaust gas cooling module can be achieved.

The outer housing 66 of the exhaust gas cooler 56 becomes at the fourth flange level 10 bolted and has a Kühlmittelauslassstutzen 82 for the removal of coolant from the coolant jacket 68 on.

After flowing through the exhaust gas cooler 56 the cooled exhaust gas passes through the exhaust outlet opening 60 and the fourth exhaust inlet 62 to a third exhaust outlet 84 , which branches off from a flue-carrying channel whose end facing the exhaust gas cooler end as a channel part 86 is used for the cooled exhaust gas and the exhaust gas control device 34 facing end as a bypass channel 54 serves. From this channel 86 . 54 branches this third exhaust outlet 84 from, which is connected to a leading to the intake manifold of the internal combustion engine exhaust gas recirculation line.

When using such an exhaust gas cooling module, coolant and exhaust gas pass from the cylinder head of the internal combustion engine into the exhaust gas inlet duct 16 or in the coolant channel 20 , While the coolant according to the position of the thermostatic valve 24 either only via the coolant channel 69 in the coolant jacket 68 of the exhaust gas cooler 56 flows or when the thermostatic valve is open 24 is conveyed to a large extent in the direction of the main radiator, as is the case in particular with sufficiently warm coolant after the starting phase, the exhaust gas from the exhaust gas inlet passage 16 via the first exhaust gas outlet arranged perpendicular thereto 39 to the exhaust control device 34 ,

During the starting phase of the engine, that is, when not yet heated coolant, the first exhaust gas quantity control device, which serves as an exhaust gas recirculation valve, usually in the closed position, while the second, serving as a bypass valve exhaust quantity control device is in a position releasing the valve seat. Thus, exhaust gas flows uncooled from the exhaust gas control device 34 in the bypass channel 54 and from here via the third exhaust outlet 84 in the exhaust gas recirculation channel.

After completion of the starting phase, the second exhaust gas quantity regulating device in the form of the bypass valve is closed, while the first exhaust gas quantity regulating device takes up its function as an exhaust gas recirculation valve. Thus, a defined exhaust gas flow, which is dependent on the position of the closing body of the second exhaust gas quantity regulating device, from the exhaust gas control device 34 over the exhaust duct 50 to the exhaust gas cooler 56 directed. While flowing through the carrier part 2 and here in particular the exhaust duct 50 The exhaust gas is already heat by the cooling water in the carrier part 2 deprived of cooled surfaces. The strongest cooling of the exhaust gas takes place in the exhaust gas cooler 56 by heat transfer from the exhaust gas to the coolant instead. The heat dissipation is not only about that from the coolant jacket 68 outflowing coolant instead, but is due to the thermal coupling of the inner housing 64 to the carrier part 2 additionally reinforced, as over the surfaces of the support member 2 Heat from the exhaust gas cooler 56 can be dissipated to the surrounding air. After flowing through the exhaust gas cooler 56 the now cooled exhaust gas passes through the third exhaust outlet 84 turn into the exhaust gas recirculation channel.

As a result of the embodiment shown and described, a significantly improved cooling performance is thus achieved in comparison with known designs, with only a small amount of installation space being used at the same time for integrating all essential components for the temperature and flow control of an exhaust system. All components remain easily accessible and easy to install.

It should be understood that the scope of the claims is not limited to the embodiment described. Thus, in particular, the structure of the exhaust gas cooler or the exhaust gas control device can be changed. If another exhaust gas cooler is used, the thermal coupling through the weld seam should accordingly not be forced on the inner housing, but on another housing part through which the exhaust gas flows. In addition, the different flange levels can be moved depending on the requirements and available installation space.

Claims (7)

An exhaust gas cooling module for an internal combustion engine with a support part, via which the exhaust gas cooling module is attached to the cylinder head of the internal combustion engine, an exhaust gas cooler, which is attached to the support member, an exhaust gas control device which is attached to the support member and controls the exhaust gas flow in the exhaust gas cooling module and a thermostatic valve, which Coolant flow from the cylinder head into the exhaust gas cooling module controls, characterized in that the carrier part ( 2 ) four flange levels ( 4 . 6 . 8th . 10 ), wherein the first flange plane ( 4 ) is attached to the cylinder head, the thermostatic valve ( 24 ) at the second flange level ( 6 ), the exhaust control device ( 34 ) at the third flange level ( 8th ) is attached and a exhaust gas flowed through housing ( 64 ) of the exhaust gas cooler ( 56 ) via at least one weld thermally coupled to the fourth flange plane ( 10 ), wherein the exhaust gas control device ( 34 ) an exhaust gas inlet opening ( 38 ), two exhaust gas quantity control devices and two exhaust gas outlet openings ( 40 . 42 of which the first exhaust gas quantity regulating device controls the exhaust gas flow to the exhaust gas cooler ( 56 ) and the second exhaust gas quantity control device controls the exhaust gas flow to a bypass channel ( 54 ) controls. Exhaust gas cooling module for an internal combustion engine according to claim 1, characterized in that in the carrier part ( 2 ) a coolant channel ( 20 . 64 ) with a coolant inlet ( 22 ), which is fluidically connected to a coolant outlet opening of the cylinder head, with a first coolant outlet ( 23 ) fitted with a coolant tube ( 26 ), which leads to a main cooler of the internal combustion engine and with a second coolant outlet ( 70 ), which with a coolant jacket ( 68 ) of the exhaust gas cooler ( 56 ) is fluidically connected, is formed. Exhaust gas cooling module for an internal combustion engine according to one of the preceding claims, characterized in that in the support part ( 2 ) an exhaust gas inlet duct ( 16 ), an exhaust duct ( 50 ) and a bypass channel ( 54 ) are formed. Exhaust cooling module for an internal combustion engine according to one of the preceding claims, characterized in that the carrier part has a first exhaust gas inlet ( 18 ), which is fluidically connected to an exhaust gas outlet opening of the cylinder head and a first exhaust gas outlet ( 39 ) connected to the exhaust gas inlet opening ( 38 ) of the exhaust gas control device ( 34 ) is fluidly connected, a second and a third exhaust gas inlet ( 46 . 48 ), which are fluidically connected to the two exhaust gas outlet openings ( 40 . 42 ) of the exhaust gas control device ( 34 ) and a second exhaust outlet ( 52 ), which with an exhaust gas inlet opening ( 58 ) of the exhaust gas cooler ( 56 ) is fluidly connected and a fourth exhaust inlet ( 62 ), which is connected to an exhaust gas outlet opening of the exhaust gas cooler ( 60 ) is fluidly connected and a third exhaust outlet ( 84 ), which is connected to an exhaust gas recirculation line of the internal combustion engine has. Exhaust cooling module for an internal combustion engine according to claim 4, characterized in that between the third exhaust gas inlet ( 48 ) and the third exhaust outlet ( 84 ) there is a fluidic connection connecting the bypass channel ( 54 ), between the second exhaust inlet ( 46 ) and the second exhaust outlet ( 52 ) there is a fluidic connection connecting the exhaust duct ( 50 ) and between the first exhaust inlet ( 18 ) and the first exhaust outlet ( 39 ) an exhaust gas inlet duct ( 16 ) is trained. Exhaust gas cooling module for an internal combustion engine according to one of the preceding claims, characterized in that the third exhaust gas outlet ( 84 ) both as an outlet of the bypass channel ( 54 ) as well as an outlet for the exhaust gas cooler ( 56 ) cooled exhaust gas is used. Exhaust gas cooling module for an internal combustion engine according to one of the preceding claims, characterized in that the exhaust gas quantity control devices via a common control unit ( 44 ) are drivable.

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