DE102008011701A1 - Exhaust gas recirculation valve for internal combustion engine of motor vehicle, has filter for purifying leakage gas in inner side of drive housing part and/or at outer side of outer wall of drive housing part - Google Patents

Abstract

The valve (1) has a pneumatic drive (5) for operating a control valve (3), and a drive housing part (45) fixedly connected with a line housing part (7). A through hole (51) is provided in an outer wall restricting the part (45) for discharge an exhaust gas arrived in the part (45) to an outer side of the outer wall, where the exhaust gas is leaked from an exhaust pipe (17). A filter is arranged for purifying the leakage gas in an inner side of the part (45) and/or at an outer side of the outer wall of the part (45). The exhaust pipe runs between a line inlet (11) and a line outlet (13).

Description

The The invention relates to an exhaust gas recirculation valve for an internal combustion engine, in particular a motor vehicle. An exhaust gas recirculation valve is generally used to a part of an exhaust gas resulting from combustion of the Internal combustion engine from the deliver to the atmosphere To divert exhaust stream and an intake air for combustion to mix in the internal combustion engine, so that the fuel-air mixture the engine is preheated, and that to the atmosphere to be dispensed exhaust gas can be at least partially cleaned.

An exhaust gas recirculation valve is for example off DE 197 27 875 C1 known in which a control valve with an actuating rod and an actuator attached to one end of an actuator rod can be displaced away from a valve seat to open a passage line in the exhaust gas recirculation valve. A pneumatic actuator causes the displacement, in which the control rod is moved back and forth in the axial direction.

It It was found that a relatively high refusal rate of the Exhaust gas recirculation valve, in particular on the drive side consists of the exhaust gas recirculation valve. Especially where vibration loads can cause voltage peaks Cracks form uncontrollably, resulting in failure of the respective Component led. Especially with pneumatic actuators for exhaust gas recirculation valve showed up the phenomenon in notches of the control rod. Also at a work and / or return chamber of the pneumatic actuator, which of the exhaust pipe additionally by a membrane is separated, corrosion damage not only showed up on the membrane but also for example on the return spiral spring.

It object of the invention, the disadvantages of the prior art to overcome, in particular an exhaust gas recirculation valve for an internal combustion engine, in particular a motor vehicle to provide with a significantly longer service life.

This object is solved by the features of claim 1. The exhaust gas recirculation valve according to the invention has a line housing, an exhaust line extending between a line inlet and a line exit of the exhaust gas recirculation valve, a control valve for at least partially interrupting and releasing an exhaust gas flow through the exhaust line, and a particularly pneumatic actuator for operating the exhaust gas recirculation valve. The exhaust gas recirculation valve also has a drive housing rigidly connected to the conduit housing. In an outer wall defining the drive housing, there is a through hole for discharging from the exhaust passage 17 leaking, reaching into the drive housing exhaust gas formed on an outer side of the outer wall. According to the invention a filter for cleaning this leakage exhaust gas inside the drive housing and / or arranged on the outside of the outer wall of the drive housing covering the through hole. It has been found by examination of the inventors of the subject of the application that the frequent failure rate of components of the exhaust gas recirculation valve drive was caused by vibration cracking corrosion. At profile jumps, such as notches and frequently mechanically loaded components, such as the return spring, a high concentration of exhaust gas components could be identified, which favor a Schwingungsrißkorrosion. Especially exhaust gas components of the seventh main group of the periodic table, enhance the corrosion behavior of mechanically stressed components.

With the inventive measure of use a filter for cleaning the leakage exhaust gas in the drive housing and / or on the outside could be a significant reduction the Schwingungsrißkorrosion be achieved. The filters have the property, the corrosion-enhancing exhaust gas components to formally attract and welcome without them the mechanically stressed components are exposed to this long. by virtue of this attraction of filters showed itself in the arrangement of a filter on the outside of the drive housing a good neutralization of the from the exhaust pipe into the drive housing reaching leakage exhaust gas can be achieved.

additionally results in addition to increasing the stability also the advantage that the leakage exhaust gas is not easy to Atmosphere is discharged, but by the use of the invention a filter is cleaned. With the invention Measure is thus ensured that even the Leaking leakage exhaust gas is filtered onto pollutants before it gets to the atmosphere is released. It turned out that a significant leakage exhaust gas flow from the exhaust pipe through the control valve to the pneumatic drive, even if sealing rings or other sealing measures in Range of the control rod are used. A complete, fluidic separation of the exhaust pipe from the pneumatic drive side, through which the control valve is operated is, if at all, very difficult to reach constructively.

In addition, with the drive housing-side arrangement of a filter according to the invention an actually meaningful pollutant balance for an internal combustion engine are created. It was shown that in the known exhaust gas recirculation valves, the Abgasleckagestömung was so large by the exhaust gas recirculation valve that a pollutant balance of an internal combustion engine has always been positive, as it is in reality. Because the leakage exhaust gas caused by the exhaust gas recirculation valve remains unconsidered in the pollutant emissions of internal combustion engines.

at A preferred embodiment of the invention is an active filter used. The active filter can be an annular body comprising an active filter material, such as activated carbon, Platinum or a conventional catalyst material formed is, which filters out the pollutants of the leakage exhaust gas flow and even attracts.

Preferably the filter is adjacent to a sliding bearing for axial guidance the control rod of the control valve arranged, in particular the sliding bearing the exhaust pipe structurally from the drive housing separates. In this case, a gap-like, by opposing Bearing surfaces of the control rod and the sliding bearing defined Off the exhaust pipe into the drive housing. Preferably is a drive-housing-side mouth of the way covered in the drive housing by the filter. It was clear that the plain bearing has a cylindrical passage can form, either through a bearing sleeve or through axially extending boundary surfaces of a housing and the adjusting rod can be formed.

at A preferred embodiment of the invention extends the drive housing side mouth of the way in essentially radially, thereby providing a good leakage exhaust gas flow velocity is achieved in the filter material.

at a development of the invention has the drive housing a radially inward and outward through housing sections limited intake for a filter body, the in only one axial direction actuator side for the Inserting the filter body is open.

Preferably the slide bearing is secured by an inside of the housing Bearing sleeve formed, the cylindrical inside a Slide bearing surface forms for the control rod.

at a development of the invention, the bearing sleeve has a Recording, in which an annular filter body is used. The recording is designed such that the annular body both the control rod as also touches the bearing sleeve, in particular axially on the adjusting rod and bears radially on the bearing sleeve, wherein the contact surfaces of the control rod and the bearing sleeve adjacent, in particular perpendicular, to each other.

alternative or additionally, the filter may be an annular one Have filter body on the compartment outer wall. Preferably, the annular filter body from a cross-sectionally L-shaped or U-shaped Guard ring surrounding, with the outer wall of the drive housing is firmly connected. This guard ring can the filter body and two adjacent radial mounting flanges of two drive housing parts one of which is directly connected to the cable housing is coupled. The mounting flanges are by a bead ring attached to each other.

at a development of the invention, the drive housing part divided into two drive housing parts, of which the one mainly in a working and / or restoring chamber and the other limit a compensation chamber. The filter can additionally to the above filter bodies or replacing them be formed by a filter body, which in the working and / or return chamber is arranged. It was found, that exhaust gas components also pass through the membrane the working and / or return chamber can get. With the arrangement of the filter in the working and / or return chamber These corrosive components can also be replaced by the Filter material from the mechanically loaded drive components kept away. Preferably, the filter body is adjacent arranged the membrane and / or the return spring.

The Membrane can be reinforced by a plate attached to it supports a return spring, which is used in the working and / or return chamber is arranged.

at a development of the invention is a housing part of Drive housing and the line housing from a Piece made, in particular of a plastic piece injected. On the housing piece can be a separated Drive housing part be attached, wherein between the separated drive housing part and the one-piece Housing the membrane is clamped fluid-tight.

Further Advantages, properties and features are given by the present Description of preferred embodiments of the invention based of the accompanying drawings, in which:

1 a cross-sectional view of an exhaust gas recirculation valve according to the invention in a first embodiment; and

2 a cross-sectional view of an exhaust gas recirculation valve according to the invention according to a second embodiment; and

3 a cross-sectional view of an exhaust gas recirculation valve according to the invention according to a third embodiment.

In 1 is the exhaust gas recirculation valve generally by the reference numeral 1 Mistake. The exhaust gas recirculation valve 1 has a control valve 3 and a pneumatic actuator 5 wherein the control valve structure and the drive structure form an interconnected structural unit.

The control valve 3 has a cable housing 7 that has an entrance 11 and an exit 13 Are defined. The control valve 3 has a valve member 15 One of the entrance 11 with the exit 13 connecting exhaust pipe 17 interrupt or release. In 1 is the valve member 15 shown in a closed position.

The valve member 15 has a sealing surface forming a sealing ring 19 made of elastic material from a support disc 21 will be carried. The support disk 21 is via a swivel joint 23 with one end 25 a control rod 27 connected, which extends in the axial direction A. For adjusting the pressure forces on joint surfaces of the swivel joint 23 is a coil spring assembly 29 intended.

The control rod 27 is in a bearing sleeve 31 axially slidably guided in one pass 33 of the cable housing 7 is used on the drive side. The bearing sleeve 31 is about a snap ring 35 and a radial shoulder 37 mounted in the axial direction A, being between the passage 33 and the outside of the bearing sleeve 31 a sealing ring 39 to prevent leakage of exhaust gas along the control rod 27 is arranged.

The passage 33 limiting, reinforced housing section 41 of the cable housing 7 ends on the drive side in a mounting flange 43 and defines an exhaust gas side drive housing part 45 Made in one piece with the cable housing 7 is formed. On the mounting flange 43 of the drive housing part 45 lies a mounting edge 47 another separate actuator drive housing part 65 at, between the adjacent radial mounting edges 45 . 47 a membrane 49 the pneumatic drive 5 is trapped.

The exhaust line side drive housing part 45 limited together with the membrane 49 a compensation chamber 50 , The drive-side drive housing part 65 limited together with the membrane 49 a working and / or restoring chamber 52 ,

In the mounting land 43 with the reinforced housing section 41 of the housing part 7 connecting, conical outer wall portion of the drive housing part 45 is a leakage through hole 51 educated.

The membrane 49 is through a reinforcing plate 53 stiffened, at which a return spring 55 supported.

The control rod 27 extends into the drive housing part 45 and through the reinforcing plate 53 through, wherein at the drive end of the control rod 27 the reinforcement plate 53 including the membrane 49 are attached.

A separate, axial, hollow extension 57 closes at the control rod 27 and before it is mounted on the control rod 27 open on the rack side. In a cavity of the axial extension 57 is a bar magnet tapering at the ends 59 arranged, which for determining the position of the valve member 15 with a Hall sensor 61 cooperates in accordance with the operation.

The axial extension 57 is in one in the drive housing part 65 trained, blind hole-like cavity 63 axially guided. The extension 57 is with the control rod 27 via a pivoting or tilting joint mechanism 69 connected, so that the axial extension 57 from the axial alignment axis A of the control rod 27 is insensitive and pivotable.

According to the first embodiment of the invention is on the outside of the housing part 7 the exhaust gas recirculation valve a filter 71 fixed so that the leakage through hole 51 is completely covered by a filter body of active filter material, such as platinum, activated carbon or the like, so that all the exhaust gas leaving the leakage through hole is exposed to the filter material. The filter body touches the outside of the housing part 7 , It has been found that the active filter material enhances removal of the exhaust components from the drive housing so that the drive components disposed in the drive housing are no longer exposed to the exhaust components.

The filter body 73 is Stellventilseitig substantially axially adjacent to the flange edge 43 arranged and protected by a guard ring 75 completely surrounded, which also includes the adjacent flanged edges 47 . 43 surrounds that by a separate flared ring 77 attached to each other.

The execution according to 2 is the execution according to 1 with regard to the structure of the exhaust gas recirculation valve in many components identical or at least similar. In this respect, easy readability of the description of the figures is due to a repeated description of the exhaust gas recirculation management valve components omitted. For similar or identical components are in 2 the same reference numerals as in 1 used.

The execution according to 2 is different from the exhaust gas recirculation valve 1 according to 1 in that the filter body 73 within the exhaust line side drive housing part 45 is arranged, adjacent to the bearing sleeve 31 ,

A recording 81 is on the reinforced housing section 41 provided, which is limited in the radial direction R by housing portions and axially on the drive side for the mounting of the filter body 73 open.

A gap-like path between the opposing mounting surfaces of the inside of the reinforced housing portion 41 and the outside of the bearing sleeve 31 discharges from the exhaust pipe 17 extending exclusively in the radial direction into the filter body 73 ,

The leakage through hole 51 is in 2 not apparent, because the sectional view is about 90 ° with respect to in 2 shown sectional view is rotated.

In 3 a further embodiment of the exhaust gas recirculation valve according to the invention is shown in cross section, the to the embodiments according to 1 and 2 is very similar, so that a repeated description of the identical or similar components is unnecessary. In this respect, for the similar or identical components of the exhaust gas recirculation valve, the same reference numerals as in 1 and 2 used. In the return exhaust valve 1 according to 3 is the filter 71 by two separate annular filter bodies 83 . 85 educated.

The one annular filter body is in the working and return chamber 52 arranged fluid-tight and is located on the reinforcing plate 53 adjacent the transition from the control rod 27 to the axial extension 57 , In this way, a close arrangement of the filter to the return spring 55 ensuring that exhaust gas components passing through the membrane 49 through, directly from the filter body 83 can be included.

The other ring body 85 is in a recording 87 Arranged by the outside of the control rod 27 and a recess in the bearing sleeve 31 is limited and the drive side is open. The annular filter body 50 has an L-shape in cross-section, with an L-leg completely in the receptacle 87 is received and the other L-leg extends radially outward.

The annular filter body 85 lies axially on the outside of the control rod 27 and radially on an adjacent to the actuating rod receiving surface of the bearing sleeve 31 at.

With the arrangement of the annular filter body 85 between the control rod 27 and the bearing sleeve 31 ensures the exhaust gas between the control rod 27 and the bearing sleeve 31 in the axial direction to the pneumatic drive 52 flows immediately before exiting into the compensation chamber 50 is caught by the filter material.

With regard to the embodiments described above, it is clear that the filter 71 by a combination of all filter bodies 73 . 83 . 85 can be formed. It is clear that only one filter body 73 . 83 . 85 can be arranged in the working and return chamber of the exhaust gas recirculation valve according to the invention, without the further filter body 73 . 83 . 85 are provided.

The same applies to the individual arrangement of an annular filter body 85 in the compensation chamber 50 ,

The in the foregoing description, figures and claims disclosed features can be used both individually and in any combination for the realization of the invention in the different embodiments. be significant.

1

Exhaust gas recirculation valve

3

Control valve

5

pneumatic drive

7

Line housing part

11

entrance

13

output

15

valve member

17

exhaust pipe

19

seal

21

carrying disc

23

Schwenkgleitgelenk

25

The End

27

control rod

29

Coil spring arrangement

31

bearing sleeve

33

passage

35

snap ring

37

radial shoulder

39

seal

41

housing section

43

mounting flange

45

Drive housing part

47

mounting edge

49

membrane

50

compensation chamber

51

Leakage through hole

52

working and / or return chamber

53

reinforcing plate

55

Return spring

57

extension

59

bar magnet

61

Hall sensor

63

cavity

65

Drive housing part

69

Swivel Kippgelenkmechanismus

71

filter

73

filter body

75

protective ring

77

Crimped

81

admission

83

filter body

85

filter body

87

admission

A

axially

R

radial direction

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• DE 19727875 C1 [0002]

Claims (18)

Exhaust gas recirculation valve for an internal combustion engine, in particular of a motor vehicle, comprising a line housing, one between a line input ( 11 ) and a line output ( 13 ) of the line housing extending exhaust pipe ( 17 ), a control valve ( 3 ) for at least partially interrupting and releasing an exhaust gas flow through the exhaust gas line ( 17 ), a particular pneumatic to drive ( 5 ) for operating the control valve ( 3 ), wherein a drive housing is rigidly connected to the line housing, and formed in an outer wall defining the drive housing through-hole ( 51 ) for discharging from the exhaust pipe ( 17 ) leaking, reaching into the drive housing exhaust gas to an outer side of the outer wall, characterized in that a filter ( 71 ) for cleaning the leakage exhaust gas inside the drive housing and / or on the outside of the outer wall of the drive housing, the through hole ( 51 ) is arranged covering. Exhaust gas recirculation valve according to Claim 1, characterized in that the filter ( 71 ) an annular body ( 78 ) of an active filter material, in particular of activated carbon. Exhaust gas recirculation valve according to one of the preceding claims, characterized in that the filter adjacent to a slide bearing for axially guiding an actuating rod ( 27 ) of the drive ( 5 ), wherein the sliding bearing the exhaust pipe ( 17 ) structurally separates from the drive housing. Exhaust gas recirculation valve according to the preceding claim, characterized in that a gap-like, by opposing bearing surfaces of the control rod ( 27 ) and the sliding bearing defined path from the exhaust pipe ( 17 ) opens into the drive housing and a drive-housing-side mouth of the path in the drive housing of the filter ( 71 ) is covered. Exhaust gas recirculation valve according to the preceding claim, characterized in that the housing-compartment-side orifice of the path substantially axially and / or radially towards the filter ( 71 ). Exhaust gas recirculation valve according to one of the preceding claims, characterized in that the housing compartment ( 45 ) a radially inwardly and outwardly by housing portions limited receptacle for a filter body ( 73 ), in the axial direction (A) actuator side for the insertion of the filter body ( 73 ) is open. Exhaust gas recirculation valve according to one of claims 3 to 6, characterized in that the sliding bearing is secured by a bearing sleeve ( 31 ) is formed, the cylindrical inner side of a sliding bearing surface for the control rod ( 27 ). Exhaust gas recirculation valve according to Claim 7, characterized in that the slide bearing sleeve has a receptacle ( 87 ) for an annular filter body ( 83 . 85 ), so that in the mounted state in the receptacle ( 87 ) the filter body ( 83 . 85 ) both the control rod ( 27 ) as well as the bearing sleeve ( 31 ), in particular axially on the control rod ( 27 ) and radially on the bearing sleeve ( 31 ) is present. Exhaust gas recirculation valve according to one of the preceding claims, characterized in that the filter ( 71 ) an attached to the outer wall of the drive housing, annular filter body ( 73 ) having. Exhaust gas recirculation valve according to the preceding claim, characterized in that the annular filter body ( 73 ) of a cross-section L- or U-shaped guard ring ( 75 ) is surrounded, which is firmly connected to the outer wall. Exhaust gas recirculation valve according to the preceding claim, characterized in that the protective ring ( 75 ) the filter body ( 73 ) and two adjacent radial mounting flanges ( 43 . 47 ) receives two drive housing parts, one of which is coupled directly to the line housing. Exhaust gas recirculation valve according to the preceding claim, characterized in that the mounting flanges ( 43 . 47 ) by a Umbördelring ( 77 ) are attached to each other. Exhaust gas recirculation valve according to one of the preceding claims, characterized in that the drive housing is replaced by a membrane ( 49 ) in two drive housing parts ( 45 . 65 ), namely in a working and / or restoring chamber ( 52 ) and a compensation chamber ( 50 ). Exhaust gas recirculation valve according to the preceding claim, characterized in that the drive housing part forming the compensation chamber ( 45 ) rigidly to the line housing ( 7 ) and the through-hole ( 51 ) having. Exhaust gas recirculation valve according to claim 13 or 14, characterized in that at least one filter body ( 73 ) of the filter ( 71 ) in the compensation chamber ( 50 ) in particular adjacent a housing passage from the drive housing in the line housing ( 7 ) is arranged. Exhaust gas recirculation valve according to one of the An Claims 13 to 15, characterized in that at least one filter body ( 73 ) in the working and / or restoring chamber ( 52 ) of the drive ( 5 ), in particular adjacent to the membrane ( 9 ) and / or a return spring ( 55 ). Exhaust gas recirculation valve according to one of Claims 13 to 15, characterized in that the membrane ( 49 ) through a plate ( 53 ) is strengthened, at which a return spring ( 55 ) in the working and / or restoring chamber ( 52 ) is arranged. Exhaust gas recirculation valve according to one of Claims 13 to 17, characterized in that a housing part ( 45 ) of the drive housing and the line housing are made of one piece, in particular plastic, on which a separated drive housing part ( 65 ), wherein between the separated drive housing part and the housing piece the membrane ( 49 ) is clamped fluid-tight.