WO2008058737A1

WO2008058737A1 - Exhaust-gas recirculation device

Info

Publication number: WO2008058737A1
Application number: PCT/EP2007/009881
Authority: WO
Inventors: Torsten-Andre Kunz; Jens Ruckwied; Hans-Peter Klein; André GROSSPIETSCH
Original assignee: Behr Gmbh & Co. Kg; Behr Thermot-Tronik Gmbh
Priority date: 2006-11-15
Filing date: 2007-11-15
Publication date: 2008-05-22
Also published as: DE102006054225A1; DE102006054225B4

Abstract

The invention relates to an exhaust-gas recirculation device of an internal combustion engine, having an exhaust-gas recirculation valve device (1) for regulating an exhaust-gas flow, and having an exhaust-gas cooler (66) for cooling the exhaust-gas flow. In order to create an improved exhaust-gas recirculation device which is of simple construction and which can be produced cost-effectively, the exhaust-gas cooler (66) and the exhaust-gas recirculation valve device (1) are accommodated in a common housing (2).

Description

Exhaust gas recirculation device

The invention relates to an exhaust gas recirculation device of an internal combustion engine, with an exhaust gas recirculation valve device for regulating an exhaust gas flow, and with an exhaust gas cooler for cooling the exhaust gas flow.

In conventional exhaust gas recirculation systems, an exhaust gas control valve is used to regulate the exhaust gas flow. For distributing the exhaust gas, an exhaust valve is used, which directs the exhaust gas flow either through the radiator or through a bypass on the radiator.

The object of the invention is to provide an improved exhaust gas recirculation device according to the preamble of claim 1, which is simple in construction and inexpensive to produce.

The object is achieved with an exhaust gas recirculation device of an internal combustion engine, with an exhaust gas recirculation valve device for regulating an exhaust gas flow, and with an exhaust gas cooler for cooling the exhaust gas flow, in that the exhaust gas cooler and the exhaust gas recirculation valve device are accommodated in a common housing. Due to the common housing, the manufacturing costs can be reduced and space can be saved. A preferred embodiment of the exhaust gas recirculation device is characterized in that an exhaust gas recirculation valve insert is arranged in the housing. The exhaust gas recirculation valve insert is preferably inserted, pressed or cast into the housing.

A further preferred exemplary embodiment of the exhaust gas recirculation device is characterized in that the exhaust gas recirculation valve insert has two spaced-apart through-holes, in which an exhaust gas recirculation valve piston is guided to and fro. The through holes are preferably circular and aligned with each other. The exhaust gas recirculation valve piston preferably has essentially the shape of a closed circular cylinder.

A further preferred exemplary embodiment of the exhaust gas recirculation device is characterized in that the through holes are provided in a guide body of the exhaust gas recirculation valve insert with a guide body interior communicating with an exhaust gas inlet. Depending on the position of the exhaust gas recirculation valve piston, one of the through holes is at least partially released from the exhaust gas recirculation valve piston. In a zero position of the exhaust gas recirculation valve piston both through holes are closed.

A further preferred exemplary embodiment of the exhaust gas recirculation device is characterized in that the exhaust gas recirculation valve insert has a drive head with a through hole at a drive end, through which a drive element of a drive device for the exhaust recirculation valve piston extends. The drive element is, for example, a piston rod which starts from the exhaust gas recirculation valve piston.

A further preferred exemplary embodiment of the exhaust gas recirculation device is characterized in that the exhaust gas recirculation valve insert is connected to an exhaust gas outlet at an outlet end. The exhaust gas recirculation valve insert is preferably from its outlet end to the Drive end formed integrally with the drive head with the guide body. At the exhaust outlet, an exhaust gas recirculation line is connected.

A further preferred embodiment of the exhaust gas recirculation device is characterized in that an exhaust gas cooler insert is arranged in the housing. The exhaust gas cooler insert is preferably inserted or pressed into the housing with the interposition of a seal.

A further preferred exemplary embodiment of the exhaust gas recirculation device is characterized in that the exhaust gas cooler insert comprises pipes surrounded by a cooling medium. The cooling medium is, for example, cooling water. Through the pipes, the hot exhaust gas flows, which is cooled by means of the cooling medium.

A further preferred exemplary embodiment of the exhaust gas recirculation device is characterized in that in each case one end of the tubes faces the exhaust gas recirculation valve insert. The tubes preferably extend parallel to one another and transversely to the exhaust gas recirculation valve insert. Preferably, the other end of the tubes opens into a valve cover.

A further preferred exemplary embodiment of the exhaust gas recirculation device is characterized in that the exhaust gas recirculation valve insert has an exhaust gas cooler inlet section, of which a part, in particular half, of the pipes emanate and an exhaust gas cooler outlet section in which a part, in particular the other half, of the pipe opens. The exhaust stream is passed through one half of the tubes from the exhaust cooler inlet section and then preferably diverted into a valve cover. After the diversion, the exhaust stream is passed through the other half of the tubes to the exhaust cooler exit section.

A further preferred exemplary embodiment of the exhaust gas recirculation device is characterized in that the exhaust gas cooler inlet section can be brought into communication with the exhaust gas inlet via one of the through-holes, in which the exhaust gas recirculation valve piston is guided to and fro. The other of the through holes is through the Abgasrückführventilkol- closed. The exhaust stream is passed through the exhaust gas cooler.

A further preferred exemplary embodiment of the exhaust gas recirculation device is characterized in that the exhaust gas cooler outlet section can be brought into communication with the exhaust gas inlet via one of the through holes, in which the exhaust gas recirculation valve piston is guided to and fro. The other of the through holes is closed by the exhaust gas recirculation valve piston. In this position of the exhaust gas recirculation valve piston, the exhaust gas flow is directed from the exhaust gas inlet via the exhaust gas cooler outlet section to the exhaust gas outlet. In this case, the exhaust gas flow is not passed through the exhaust gas cooler.

A further preferred exemplary embodiment of the exhaust gas recirculation device is characterized in that an exhaust gas flow emerging from the tubes of the exhaust gas cooler inlet section is deflected into the tubes of the exhaust gas cooler outlet section in a housing cover which closes the housing. Thus, starting from the exhaust gas cooler inlet section, the exhaust gas flow is first passed through one half of the tubes, then deflected in the housing cover and passed through the other half of the tubes to the exhaust gas cooler outlet section.

Another preferred embodiment of the exhaust gas recirculation device is characterized in that the exhaust gas cooler output section extends between the drive end and the guide body. The guide body is integrally connected to the drive head at the drive end of the exhaust gas recirculation valve insert.

Another preferred embodiment of the exhaust gas recirculation device is characterized in that the exhaust gas cooler outlet section extends between the outlet end and the guide body. The guide body is integrally connected to the outlet end of the Abgasrückführventilein- set. Further advantages, features and details of the invention will become apparent from the following description in which, with reference to the drawings, an embodiment is described in detail. Show it:

Figure 1 is a perspective view of an exhaust gas recirculation valve device according to the invention;

Figure 2 shows the exhaust gas recirculation valve device of Figure 1 in side view;

3 shows the exhaust gas recirculation valve device of Figures 1 and 2 in front view and

4 shows the view of a section along the line IV-IV in Figure 3.

The performance of an internal combustion engine depends, among other things, on displacement, speed and average gas pressure. By charging the engine, the filling can be significantly improved and thus the engine power can be increased. The fuel-air mixture and the air are pre-compressed in whole or in part outside the cylinder. In an exhaust turbocharged engine, the exhaust gases drive the turbine and the compressor. The compressor takes over the intake and delivers a pre-compressed fresh gas charge to the engine. A charge air cooler or exhaust gas cooler in the charge line dissipates the heat of compression to the ambient air. As a result, the cylinder filling is further improved.

The exhaust gas recirculation serves to cool the exhaust gas as far as possible.

In particular, in one embodiment of the invention, the recirculated exhaust gas is returned to the combustion of the internal combustion engine.

In particular, in another embodiment of the invention, not shown, the recirculated exhaust gas no longer takes part in the combustion in the internal combustion engine, but heats up. Overall, the temperature in the internal combustion engine or the engine is lowered by the recirculated exhaust gas. Low temperatures in the engine can reduce the formation of nitrogen oxides, which is heavily dependent on the temperature in the engine. In particular, the exhaust gas recirculation leads to a reduction in the HC emissions, since in particular the proportion of oxygen decreases.

In FIGS. 1 to 4, an exhaust gas recirculation valve device according to the invention is shown in different views. The exhaust gas recirculation device 1 comprises a housing 2 with an exhaust gas inlet 4. Exhaust gas passes through the exhaust gas inlet 4 into the housing 2. The exhaust gas inlet 4 is recessed in an exhaust gas inlet flange 5 which protrudes from a side surface of the housing 2 and has four threaded blind holes 6, 7, 8, 9 has. The exhaust gas inlet flange serves to connect the exhaust gas recirculation valve device 1 to an exhaust gas recirculation line (not shown) of an internal combustion engine.

The housing 2 of the exhaust gas recirculation device 1 is bounded on its end face facing away from the exhaust gas inlet flange 5 by a housing flange 11 which protrudes outwardly beyond the housing 2 and has four through holes. The through holes serve to receive fastening means, such as screws, with the aid of which a cover flange 12 of a housing cover 13 can be fastened to the housing flange 11. Between the housing flange 11 and the cover flange 12, a seal 14 is arranged.

Externally, the housing 2 of the exhaust gas recirculation valve device 1 has two cooling water connecting pieces 16 (in FIG. 1) and 17 (in FIG. 2). Cooling water enters the interior of the housing 2 through one of the cooling-water connection sockets. The cooling-water connection pipe again leads the cooling-water out of the housing 2.

The exhaust gas supplied to the housing 2 through the exhaust gas inlet 4 is cooled in the housing 2 with the aid of the cooling water and exits the housing 2 at an exhaust gas outlet 18. As will be explained below, the exhaust gas can also be passed uncooled through the housing 2 become. For regulating the exhaust gas flow, which enters the housing 2 through the exhaust gas inlet 4, an exhaust gas recirculation valve insert 20 is arranged in the housing 2. The exhaust gas recirculation valve insert 20 is pressed into a corresponding receiving space of the housing 2. For this purpose, a plurality of (unspecified) fixing lugs are provided on the exhaust gas recirculation valve insert 20. The exhaust gas recirculation valve insert 20 can also be poured into the housing 2.

The exhaust gas recirculation valve insert 20 has a drive end 21 with a Anbskopf 22 which closes an opening in the housing 2. The drive head 22 serves to pass through a drive element 24 of a (only schematically indicated) drive device 25. The drive element 24 is, for example, a piston rod 26 which is guided through a central through hole 27 in the drive head 22. The piston rod 26 is based on an exhaust gas recirculation valve piston 28, which is also indicated only schematically and has substantially the shape of a vertical circular cylinder.

The exhaust gas recirculation valve piston 28 is guided into two through holes 31, 32, which are recessed in a substantially tubular guide body 34 of the exhaust gas recirculation valve insert 20. The tubular guide body 34 is hollow on the inside and comprises a guide body interior 35. The guide body interior 35 is open on one side (in FIG. 4, right) to the exhaust gas inlet 4. 4, the guide body interior 35 of the tubular guide body 34 is closed by an end wall 38. The end wall 38 abuts against a stop 40 fixed to the housing. Between the guide body 34 and the drive end 21, the exhaust gas recirculation valve insert 20 has an exhaust gas cooler inlet section 41 In the opposite direction, that is between the guide body 34 and an outlet end 44, the exhaust gas recirculation valve insert 20 has an exhaust gas cooler outlet section 42.

Between the exhaust gas recirculation valve insert 20 and the housing cover 13, a cooling water receiving space 50 is provided in the housing 2, in which an exhaust gas cooler insert 52 is received with the interposition of a seal 54. The exhaust cooler insert 52 includes several is taken. The exhaust cooler insert 52 comprises a plurality of inlet pipes 61, 62 and a plurality of outlet pipes 64, 65. The pipes 61, 62, 64, 65 are traversed by exhaust gas in dependence on the position of the exhaust gas recirculation valve piston 28. Furthermore, the tubes 61, 62, 64, 65 are surrounded by cooling water, which is conducted by means of the cooling water connecting pieces 16, 17 through the cooling water receiving space 50 past the tubes. The exhaust gas cooler insert 52 with the pipes 61, 62, 64, 65 flowing around through cooling water forms an exhaust gas cooler 66 in the housing 2. When the exhaust gas recirculation valve piston 28 is moved from the position shown in FIG. 4 towards the exhaust gas outlet 18, that is, downward in FIG , then the through hole 31 in the guide body 35, at least partially released. For this purpose, in particular control geometries can be arranged at the end of the exhaust gas recirculation valve piston 28, such as, for example, longitudinal grooves which can be attached to the end of the exhaust gas recirculation piston. When the through-hole 31 is at least partially released from the exhaust gas recirculation valve piston 28, exhaust gas may flow past the exhaust return valve piston 28, as indicated by an arrow 74.

The incoming exhaust gas is indicated by an arrow 71, the exiting exhaust gas is indicated by an arrow 72. The flowing through the through hole 31 exhaust gas, which is indicated by the arrow 74, passes through the exhaust gas cooler inlet portion 41 into the inlet pipes 61, 62 of the exhaust gas cooler insert 52, as indicated by an arrow 75. An arrow 76 indicates that the exhaust gas emerging from the inlet pipes 61, 62 is deflected in the housing cover 13. The diverted exhaust gas passes through the exit tubes 64, 65 into the exhaust cooler exit section 42, as indicated by an arrow 77. The cooled exhaust gas then exits the housing 2 at the exhaust outlet 18, as indicated by the arrow 72.

An arrow 79 indicates that the exhaust gas entering the guide body interior 35 through the exhaust gas inlet 4 also passes uncooled via the exhaust gas cooler outlet section 42 to the exhaust gas outlet 18 when the exhaust gas recirculation valve piston 28 is in the position shown in FIG. ment from the exhaust outlet 18 away, that is, in Figure 4 upwards, is moved. Then, at least a part of the through-hole 32 is released from the exhaust gas recirculation valve piston 28.

Claims

Patent claims

1. exhaust gas recirculation device of an internal combustion engine, with an exhaust gas recirculation valve device (1) for regulating an exhaust gas flow, and with an exhaust gas cooler (66) for cooling the exhaust stream, characterized in that the exhaust gas cooler (66) and the Abgasrückführven- tileinrichtung (1) in a common housing (2) are housed.

2. Exhaust gas recirculation device according to claim 1, characterized in that in the housing (2) an exhaust gas recirculation valve insert (20) is arranged.

3. Exhaust gas recirculation device according to claim 2, characterized in that the exhaust gas recirculation valve insert (20) has two spaced apart through holes (31, 32), in which an exhaust gas recirculation valve piston (28) is guided to and fro movable.

4. Exhaust gas recirculation device according to claim 3, characterized in that the through holes (31, 32) are provided in a guide body (34) of the exhaust gas recirculation valve insert (20) with a guide body interior space (35) which is connected to an exhaust gas inlet (18). bond stands.

5. Exhaust gas recirculation device according to one of claims 2 to 4, characterized in that the exhaust gas recirculation valve insert (20) at a drive end (21) has a drive head (22) with a through hole (27) through which a drive element (24) of a drive device (25) for the exhaust gas recirculation valve piston (28) extends therethrough.

6. exhaust gas recirculation device according to one of claims 2 to 5, characterized in that the exhaust gas recirculation valve insert (20) on a

Outlet end (44) with an exhaust gas outlet (18) is in communication.

7. Exhaust gas recirculation device according to one of claims 2 to 6, characterized in that in the housing (2) an exhaust gas cooler insert (52) is arranged.

8. Exhaust gas recirculation device according to claim 7, characterized in that the exhaust gas cooler insert (52) of a cooling medium flows around pipes (61, 62,64,65).

9. exhaust gas recirculation device according to claim 8, characterized in that in each case one end of the tubes (61, 62,64,65) faces the exhaust gas recirculation valve insert (20).

10. Exhaust gas recirculation device according to claim 9, characterized in that the exhaust gas recirculation valve insert (20) has a Abgaskühlerein- gangsabschnitt (41) from which a part, in particular a half, the pipes (61, 62) go out.

11. Exhaust gas recirculation device according to claim 10, characterized in that the exhaust gas recirculation valve insert (20) has an exhaust gas cooler outlet section (42) in which a part, in particular the other half, of the pipes (64, 65) opens.

12. Exhaust gas recirculation device according to claim 11, characterized in that the exhaust gas cooler input portion (41) via one of the through holes (31), in which the exhaust gas recirculation valve piston (28) is guided reciprocally movable, with the exhaust gas inlet (4) can be brought into connection.

13. Exhaust gas recirculation device according to claim 11 or 12, characterized in that the exhaust gas cooler outlet section (42) via one of the through holes (32), in which the Abgasrückführventilkol- ben (28) is guided back and forth, with the exhaust gas inlet (4) in connection can be brought.

14, exhaust gas recirculation device according to one of claims 11 to 13, characterized in that one of the tubes (61, 62) of the exhaust gas cooler inlet portion (41) exiting exhaust gas flow in a housing cover (13) which closes the housing (2), in the pipes

(64,65) of the exhaust gas cooler output section (42) is deflected.

15. Exhaust gas recirculation device according to one of claims 11 to 14, characterized in that the exhaust gas cooler input portion (41) extends between the drive end (21) and the guide body (34).

16. Exhaust gas recirculation device according to one of claims 11 to 15, characterized in that the exhaust gas cooler outlet section (42) extends between the outlet end (44) and the guide body (34).