EP1926906A1

EP1926906A1 - Device for controlling an exhaust gas stream

Info

Publication number: EP1926906A1
Application number: EP06776518A
Authority: EP
Inventors: Claus Beck; Karsten Emrich; Michael Halblaub; Dieter Werner
Original assignee: Behr GmbH and Co KG
Current assignee: Mahle Behr GmbH and Co KG
Priority date: 2005-09-08
Filing date: 2006-07-31
Publication date: 2008-06-04
Also published as: US20080216469A1; DE102005044088A1; WO2007028464A1

Abstract

The invention relates to a device for controlling an exhaust gas stream, in particular of an internal combustion engine in a passenger vehicle. Said device comprises a housing that can be traversed by exhaust gas (1) and a first displaceable actuating element (5) that is supported on the housing (1). The exhaust gas stream can be selectively guided into a first exhaust gas conduit (3) and/or a second exhaust gas conduit (4) by the displacement of the first actuating element (5). A second actuating element (15) is provided on the housing (1), said actuating element controlling a variable of the exhaust gas stream.

Description

Device for controlling an exhaust gas flow

The present invention relates to a device for controlling an exhaust gas flow according to the preamble of claim 1.

In modern internal combustion engines, especially diesel engines, exhaust gas recirculation systems are increasingly used to reduce pollutants. These and other systems require devices for regulating and controlling exhaust gas flows which, owing to the special requirements such as installation space (in particular in the case of passenger cars), temperature, cost and reliability, require independent developments.

DE 102 03 003 A1 describes an exhaust gas heat exchanger with a housing which is rectangular in cross-section and which comprises a heat exchanger flow area and a bypass flow area. A control flap which can be driven mechanically via a rotary shaft is provided on the heat exchanger, by means of which an inflowing exhaust gas flow can be conducted to either the heat exchanger area or the bypass area. Schematically also a downstream of the heat exchanger and structurally separate control valve is described, by means of which the total amount of an exhaust gas flow recirculated to the engine is adjustable.

It is the object of the invention to provide a device for controlling an exhaust gas flow, which occupies a particularly small space and has a high integration of components.

This object is achieved according erfindungsge- measure for a device mentioned above with the characterizing features of claim 1. The arrangement of the two adjusting elements in the same housing a significant reduction in space is possible. In addition, the housing with the two control elements is only a single unit, which brings logistic advantages and reduced costs. At the same time, the maintenance of two separate control elements, which on the one hand serve to adjust the total exhaust gas flow and, on the other hand, distribute the exhaust gas flow to two different exhaust gas passages, permits a particularly high level of flexibility in setting an exhaust gas guide, in particular an exhaust gas recirculation a passenger car diesel engine, to maintain.

In a preferred embodiment, the first of the exhaust ducts is connected to an exhaust gas cooler and the second of the exhaust ducts with a bypass line for bypassing the exhaust gas cooler. Particularly preferably, the bypass line is arranged in a common housing with the exhaust gas cooler. As a result, an exhaust-gas recirculation system is designed to be space-optimized in a simple manner, wherein an operation, for example by means of the bypass line, is achieved. is also possible with icing of the exhaust gas cooler by exhaust gas condensate.

In the interest of a simple mechanical realization of a device according to the invention, the adjusting element can be driven via a rotatable shaft supported on the housing. Further preferably, the rotatable shaft is driven via an actuator supported on the housing, so that the drive unit or the actuator of the first control element forms a structural unit with the device according to the invention.

Particularly preferably, a valve seat of the second actuating element is provided on the housing. Depending on the requirements of the tightness and the manufacturing cost of the valve seat can be formed during a casting of the housing, which optionally can be done post-processing. But it can also be the fixed attachment of a separate valve seat on the housing, either by pressing or positive connection. This is preferably the case when the material of the housing has no suitability for forming a valve seat. In this case, the second control element particularly preferably has a valve disk which corresponds to the valve seat and which is connected to an actuator via a slide rod. Particularly preferred is a comprehensive the slide rod and the valve seat assembly of the second actuating element releasably connected to the housing. As a result, the second actuator of its type is particularly well suited for metering the exhaust stream and at the same time easily accessible for maintenance.

In a preferred embodiment, the housing in the region of the first and the second exhaust passage on a comprehensive two channels, substantially rectangular cross-section. Alternatively, the cross section may also have a different shape. There are generally known exhaust gas cooler with integrated bypass channel, for example, by the aforementioned DE 102 03 003 A1, which are connectable in the region of the first and the second exhaust passage to the housing. Such a connection is made regularly by permanent welding, but can also be a detachable connection, optionally with the addition of a sealant and the manner of a screw-flange. Such a detachable connection would in particular make the first actuating element accessible to maintenance in a simple manner.

Generally preferred is a third exhaust passage is provided on the housing, which forms a supply or discharge of the entire exhaust gas flow of the first and second exhaust passage. In general, a device according to the invention can be used so that the adjusting elements are arranged downstream of a third exhaust duct or upstream. Depending on the specific requirements, one or the other arrangement of the device in an exhaust system may be preferred. For the purpose of a simple and inexpensive connection, the third exhaust gas duct preferably has a substantially circular cross section.

In order to enable a particularly space-optimized arrangement of the device according to the invention in an engine compartment of a motor vehicle, in particular a passenger car, according to requirements, the third exhaust gas line - A -

Nal in a connection region of the housing on a different direction than the first and second exhaust passage, in particular, the directions of the first and second exhaust passage are the same and the direction of the third exhaust passage for this purpose is angled approximately 90 °.

In the interest of a simple and space-optimized arrangement, the second actuating element, subsequently the first actuating element and then the first and the second exhaust gas channel, is initially arranged in the housing starting from the third exhaust gas duct.

Preferably, an actuator of the first control element and / or an actuator of the second control element is designed as a pressure cell. As a result, a drive of a respective actuating element can be provided in a cost-effective manner.

Preferably, an actuator of the first control element and / or an actuator of the second control element is designed as an electromechanical component. As a result, under certain circumstances, precise intermediate positions of the adjusting elements are made possible.

Further advantages and features will become apparent from the embodiment described below and from the dependent claims.

Hereinafter, a preferred embodiment of a device according to the invention will be described and explained in more detail with reference to the accompanying drawings.

Fig. 1 shows a perspective view of a total of the invention

Contraption. Fig. 2 shows the device of Fig. 1 from a different perspective.

FIG. 3 shows a further spatial view of the device from FIG. 1, wherein an assembly with parts of a second control element is shown separated. FIG. 4 is a plan view from the side of the device of FIG. 3. FIG.

The central element of the device according to the invention is a relatively complicated housing 1, which in the present case is produced as a one-piece component in a casting process. The housing may also be composed of several individual parts, in particular by means of welding or by means of detachable connections.

The housing 1 has an opening 2 of substantially rectangular cross-section, which is aligned according to FIG. 1 obliquely left from the plane of the drawing. This opening 2 forms the end of a first exhaust gas duct 3 and the end of a second exhaust gas duct 4. The two exhaust gas ducts 3, 4 are separated from one another by a first adjusting element 5 designed as a flap. An end baffle 5a of the control element 5 terminates in the region of the opening 2 and defines there the separation of the two exhaust channels 3, 4. The movable flap 5 is fixed on a rotatable shaft 6, which passes through an outer wall of the housing 1 and in the region of this passage against the housing 1 is supported rotatably supported. The movable flap 5 is located in end positions of their adjustment at each seat edge 5b. In each of these end positions, one of the exhaust ducts 3, 4 is completely closed and the other is completely open.

Outside the housing 1, the rotary shaft 6 is provided with a return spring 7, wherein an eccentric pin 8 of the rotary shaft 6 is connected via a push rod 9 with an actuator 10 of the first adjusting element 5. The actuator 10 is connected via a retaining plate 11 fixed to the housing 1. The actuator 10 is designed as a vacuum box with a vacuum connection 10 a.

As particularly shown in FIGS. 1 and 3, a rotation of the rotatable shaft 6 driven by the actuator 10 can cause such an adjustment of the control flap 5 that either the first exhaust duct 3 or the second exhaust duct 4 are completely or almost completely closed. But it is also the setting of an intermediate position possible, in which the Distribution of a total exhaust gas flow to the two exhaust channels 3, 4 takes place in a dependent on the position of the butterfly valve ratio.

An unillustrated exhaust gas cooler with a bypass line integrated therein has a substantially rectangular cross-section and is adapted to be connected to the rectangular opening 2 of the housing 1. In the present case, this connection is permanent and takes place by welding or brazing. This type of connection contributes to the generally high temperatures in the opening 2 account. For the formation of such an exhaust gas cooler with integrated bypass line reference is made in particular to the already mentioned at the beginning of DE 102 03 003 A1.

A third exhaust passage 12 of the housing 1 terminates in an opening 12a of circular cross-section. About this third exhaust passage 12, the housing 1 is connected via pipes, not shown, with a central exhaust pipe of an internal combustion engine of a car, wherein the connection is generally at a fixed branch.

After the circular connection opening 12a, the third exhaust duct has a curvature of 90 ° (see in particular Fig. 2) and then enters an expanded, substantially cylindrical portion 13 of the housing 1 a. In the region of section 13, a valve seat 14 of a second actuating element 15 is provided on the housing 1. In the present case, it is a post-processed area, which is formed of the same material as the rest of the housing 1. However, it can also be a pressed-in valve seat made of a different material.

The cylindrical portion 13 has in its wall an opening 16, which is followed by the further Gehäuseausformung, wherein behind the opening 16 is an expansion of the cross section of the third exhaust passage. In this housing region, the adjustable division of the exhaust gas flow of the third exhaust gas passage to the first exhaust passage 3 and the second exhaust passage takes place by means of the adjusting flap. 5 At the end of the cylindrical portion 13, a flange 17 is provided, with which an assembly of the second actuating element 15 is sealingly screwed. This assembly of the second control element 15 includes a second actuator 18 and a standing with the actuator 18, translationally movable slide rod 19 with an end of the slide rod 19 fixed valve disc 20 and a mating flange 21. The actuator 18 is also a vacuum box with a Pressure port 18 a designed. An electrical connection 18b is used for the controlled control of the actuator 18, wherein in the actuator 18, a control valve, not shown, is provided for the negative pressure.

When the assembly with the flange 17 is sealingly connected via a counter-bottle 21 connected to the actuator 18, the slide rod 19 projects with the valve disk into the cylindrical portion 13 of the housing 1. In this case, the slide rod 19 when fully extended from the actuator 18, the valve plate 20 sealingly press into the valve seat 14, so that no exhaust gas, the cylindrical portion 13 and the opening 16 can happen more. Likewise, by controlled retraction of the slide rod 19, a defined and metered release of an opening is possible, so that a total exhaust gas flow of the device according to the invention by the second actuator 15 is adjustable. The valve 14, 19, 20 is pressurized in the presently preferred arrangement on a motor vehicle in the opening direction through the exhaust gas flow. But it can also be pressurized in the closing direction.

As can be seen from the spatial representations in particular according to FIG. 1 and FIG. 2, in the present embodiment, the opening 12a of the third exhaust duct 12 is oriented in a direction substantially perpendicular to the direction of the parallel exhaust ducts 3, 4. As a result, a specific specification of a space in a car engine compartment is taken into account. It can be seen that by a suitable modification of the connection region of the third exhaust gas duct 12 and a modification of the housing 1, in particular with regard to the orientation of the cylindrical region 13 relative to the exhaust ducts 3, 4, another specification of a construction space can be taken into account.

Claims

Patent claims

1. A device for controlling an exhaust gas flow, in particular a passenger car internal combustion engine, comprising a housing (1) through which exhaust gas can flow, a movable first actuating element (5) supported on the housing (1), the exhaust gas flow being regulated by an adjustment of the first actuating element (5 ) optionally in a first exhaust duct (3) and / or a second exhaust duct (4) can be guided, characterized in that a second adjusting element (15) for regulating a size of the exhaust gas flow to the housing (1) is arranged.

2. Device according to claim 1, characterized in that the first of the exhaust ducts (3) is connected to an exhaust gas cooler and that the second of the exhaust ducts (4) is connected to a bypass line for bypassing the exhaust gas cooler.

3. Apparatus according to claim 2, characterized in that the bypass line is arranged in a common housing with the exhaust gas cooler.

4. Device according to one of the preceding claims, character- ized in that the first adjusting element (5) via a on the housing (1) supported rotatable shaft (6) can be driven.

5. Apparatus according to claim 4, characterized in that the rotatable shaft (6) via a preferably on the housing (1) supported actuator (10) is drivable.

6. Device according to one of the preceding claims, characterized in that a valve seat (14) of the second actuating element (15) on the housing (1) is provided.

7. The device according to claim 6, characterized in that the second adjusting element (15) to the valve seat (14) corresponding valve disc (20) which is connected via a slide rod (19) with an actuator (18).

8. The device according to claim 7, characterized in that a slide rod (19) and the valve seat (14) comprehensive assembly of the second actuating element releasably connected to the housing (1) is connectable.

9. Device according to one of the preceding claims, characterized in that the housing (1) in the region of the first and the second exhaust passage (3, 4) comprises a two channels, substantially rectangular cross-section (2).

10. Device according to one of the preceding claims, characterized in that a third exhaust passage (12) is provided on the housing, which forms a supply or discharge of the entire exhaust gas flow of the first and second exhaust passage (3, 4).

11. The device according to claim 10, characterized in that the third exhaust gas channel (12) has a substantially circular cross section (12 a).

12. The device according to claim 10 or 11, characterized in that the third exhaust duct (12) in a connection region (12a) of the

Housing has a different direction than the first and second exhaust passage (3, 4), in particular, the directions of the first and second exhaust passage are the same and the direction of the third exhaust passage for this purpose is angled approximately 90 degrees.

13. Device according to one of claims 10 to 12, characterized in that in the housing (1) starting from the third exhaust passage (12), first the second control element (15), subsequently the first control element (5) and then the first and second exhaust duct (3, 4) are arranged.

14. Device according to one of the preceding claims, characterized in that an actuator (10) of the first adjusting element (5) and / or an actuator (18) of the second adjusting element (15) are formed as a pressure box.