DE102019214264B4 - Exhaust flap valve with thermally insulated seal and internal combustion engine and motor vehicle herewith - Google Patents

Abstract

Having a flap valve (10) for an exhaust system (78) of an internal combustion engine (76).
- a flow-through valve housing (12),
- a flap shaft (14) on which a valve flap (20) is held for changing a flow cross section of the valve housing (12),
- a bearing bush (22) from which a first end (24) of the flap shaft (14) protrudes,
- A plain bearing (25) arranged between the flap shaft (14) and the bearing bush (22).
- a ring part (26) which is fastened to the first end (24) of the flap shaft (14) and the bearing bush (22) engages radially on the outside circumferentially,
- a radial seal (30), which is arranged between the bearing bush (22) and the ring part (26) and sealingly abuts the bearing bush (22) and the ring part (26) in the radial direction, for which purpose the bearing bush (22) has a radially outer lying sealing surface (32) and the ring part (26) has a radially inner sealing surface (34).

Description

The invention relates to a flap valve for an exhaust system of an internal combustion engine, in particular a motor vehicle, having a valve housing through which flow can take place, a flap shaft on which a valve flap for changing a cross-section of the valve housing through which flow can flow is held, and a bearing bush from which a first end of the flap shaft protrudes.

It is known to arrange a radial seal between the flap shaft and the bearing bush in such a flap valve, so that the radial seal bears sealingly on the flap shaft radially on the outside and on the bearing bush radially on the inside. Since the flap shaft is heated during operation of the flap valve by the exhaust gas flowing through the valve housing, the radial seal is also exposed to high temperatures. The temperature resistance of the radial seal therefore limits the permissible exhaust gas temperatures.

DE 10 2013 101 983 A1 describes a flap device with a flap body fastened on an actuating shaft. The control shaft is mounted in a flow housing via two carbon bearings, of which a first carbon bearing is arranged in a continuous housing bore through which the control shaft protrudes from the flow housing to the outside. A washer is fastened to the outwardly protruding end of the control shaft by means of a circumferential welded connection. On its outer circumference, the disk has a sleeve which extends towards the flow housing and partially radially surrounds the bearing area of the flow housing. An axial end of the carbon bearing protrudes axially slightly beyond the bearing area of the flow housing and rests against a sealing disk which radially surrounds the control shaft at a slight distance and whose surface facing the carbon bearing is flat. An axially opposite surface of the sealing washer is spherically curved in its radially outer region. This spherically shaped surface bears directly against a back wall of the pulley attached to the actuator shaft. The backplane has a negative spherical curvature.

Out DE 10 2016 221 401 A1 a valve device is known in which a lever arm is integrally connected to one end of a valve shaft which protrudes through a valve housing. A wave washer is arranged in the axial direction between the valve housing and the lever arm.

In DE 197 07 599 A1 describes a throttle valve device for an intake manifold system of an internal combustion engine.

A valve for an air supply system of an internal combustion engine is known from US 2013/0 186 378 A1. The valve may include a sleeve and a sealing element.

DE 10 2017 119 958 A1 discloses a valve assembly for regulating fluid flow in an internal combustion engine. The valve assembly includes a valve housing defining a bore with a first axis extending along the length of the bore, and a valve stem partially disposed within the bore along a second axis that is perpendicular to the first axis. In addition, the valve assembly includes a valve plate coupled to the valve stem and disposed within the bore, and a restricting device including a stop member and an engagement member.

It is the object of the invention to specify a reliably sealed flap valve with high temperature resistance. Furthermore, it is the object of the invention to specify an internal combustion engine and a motor vehicle with a reliably sealed flap valve with high temperature resistance.

This object is achieved according to the invention by a flap valve according to claim 1 and by an internal combustion engine according to claim 15 and a motor vehicle according to claim 16.

According to the invention, a flap valve is provided for an exhaust system of an internal combustion engine, in particular of a motor vehicle. The flap valve has a valve housing through which fluid can flow. During operation of the internal combustion engine, an exhaust gas flow from the internal combustion engine can be routed through the valve housing. The flap valve also has a flap shaft. In the context of the present invention, directional information such as radial and axial relates to a longitudinal axis of the flap shaft. A valve flap for changing a flow cross section of the valve housing is held on the flap shaft. The flow of exhaust gas through the valve body can be regulated by turning the butterfly valve shaft. The flap valve also has a bearing bush, from which a first end of the flap shaft protrudes. In other words, the flap shaft protrudes through the bearing bush. On a first side of the bearing bush (facing away from the valve housing), the first end of the flap shaft protrudes away from the valve housing beyond the bearing bush; The valve flap is arranged on the flap shaft on a second side of the bearing bush (facing the valve housing). The bearing bush is connected directly or preferably indirectly to the valve housing in a gas-tight manner. The bearing bush serves to preferably indirect support of the flap shaft on the valve housing.

A slide bearing, in particular a graphite bush, is arranged between the flap shaft and the bearing bush. The flap shaft can be mounted with low friction and precisely by means of the plain bearing. Furthermore, the sliding bearing can reduce heat input from the flap shaft into the bearing bush. Since the flap shaft is supported on the sliding bearing and is guided radially via this, a mechanical load on a radial seal can also be reduced. The plain bearing is typically pressed into the bearing bush so that the flap shaft can be rotated relative to the plain bearing.

According to the invention, the flap valve has an annular part which is fastened to the first end of the flap shaft and extends over the bearing bushing radially on the outside. In other words, the ring part extends in the axial direction at least in sections over the bearing bush. In particular, a collar of the annular part can encompass the bearing bush. The ring part, in particular its collar, continuously surrounds the bearing bush in the circumferential direction. The attachment of the ring part to the first end of the flap shaft is basically designed to be gas-tight. The ring part can be pressed with the butterfly valve shaft. The ring part is preferably welded to the flap shaft, in particular welded all around.

Furthermore, according to the invention, the flap valve has a radial seal which is arranged between the bearing bush and the ring part and bears sealingly against the bearing bush and the ring part in the radial direction. The radial seal thus rests radially on the outside on the bearing bush and radially on the inside on the annular part. The ring part has a radially inner sealing surface for contact with the radial seal. The bearing bush has a radially outer sealing surface for contact with the radial seal. Since the radial seal according to the invention does not bear directly against the flap shaft, but is separated from the flap shaft by the annular part and the bearing bush, heat input from the flap shaft into the radial seal can be reduced. Due to the arrangement of the radial seal according to the invention, neither the radial seal nor the sealing surfaces on the bearing bush and on the ring part are heated above a permissible temperature, even at very high exhaust gas temperatures. Since, according to the invention, the radial seal rests in a sealing manner on the bearing bush and the ring part, the flap valve is also very tight; in other words, a leakage flow of exhaust gas out of the valve housing can be kept extremely small, preferably negligible.

The bearing bush preferably has a shoulder on which the radial seal is supported in the axial direction. The radial seal can be precisely positioned over the shoulder. In addition, the contact with the shoulder simplifies the assembly of the radial seal on the bearing bush.

The radial seal can be held immovably on the bearing bush, in particular by resting against the shoulder. The radial seal thus provides a static seal against the bearing bush; there is dynamic sealing against the ring part.

Provision can be made for the radial seal to have two sealing wings projecting from a base part of the radial seal. Such a radial seal can compensate for certain eccentricities, out-of-roundness or other deviations in shape and/or position of the sealing surfaces on the annular part and the bearing bush. The sealing wings are preferably biased away from one another in the radial direction by an expanding element. As a result, the tightness can be further improved. The spreading element can be made of steel, in particular stainless steel.

The radial seal is preferably arranged in such a way that the sealing wings protrude away from the valve housing. When pressure is applied, the sealing wings of the radial seal are therefore pressed more strongly against the bearing bush and the ring part.

The radial seal can have a sealing body made of PTFE, in particular carbon-filled PTFE. PTFE has high temperature resistance, a low coefficient of friction and high chemical resistance.

The flap valve can have a spring element which pretensions the flap shaft in the axial direction relative to the valve housing. Thermal size changes, in particular of the flap shaft and the valve housing, can be compensated for via the spring element. The spring element can cause the flap shaft to rest without play on a bearing body of a bearing arrangement of the flap valve. The spring element can in particular bias the annular part away from the valve housing. As a result, contact between the ring part and the bearing bush can be avoided. The spring element can be designed as a compression spring, in particular a preferably cylindrical helical compression spring. The spring element can be supported directly or preferably indirectly on the ring part. The spring element can directly or preferably As indirectly supported via a support element on the valve housing.

A torque introduction device can be provided at the first end of the flap shaft. An actuator can adjust the valve flap by means of the flap shaft via the torque introduction device. The torque introduction device is preferably attached to the ring part. As a result, the butterfly valve can be made compact in the axial direction. The torque initiating device may include a pulley assembly. The flap valve can then be operated flexibly via a cable pull. Alternatively, the torque introduction device can have a lever mechanism. The actuator can then be a linear actuator.

The radial seal and the sliding bearing can be arranged so that they overlap in the axial direction. As a result, the thermal load on the radial seal can be further reduced. In addition, with this arrangement, a precise alignment of a sealing surface on the bearing bush relative to the flap shaft can be obtained.

The bearing bush can be attached to an insert sleeve in a sealing manner. This can simplify the assembly of the flapper valve. In particular, it can be provided that first the insert sleeve is fastened to the valve housing and then the bearing bush is fastened to the insert sleeve. Furthermore, the insert sleeve can contribute to the thermal insulation of the bearing bush from the valve housing.

The insert sleeve is preferably inserted into a through-opening of the valve housing in a sealing manner. The insert sleeve can therefore bring about a gas-tight connection between the valve housing and the bearing sleeve.

The insert sleeve can protrude through the through-opening. This can simplify the assembly of the insert sleeve on the valve housing. The valve flap preferably has a recess which at least partially follows a contour of the insert sleeve which projects into the valve housing. As a result, in a closed position, the valve flap can largely reduce a flow cross section of the valve housing, in particular almost completely prevent flow through the valve housing.

A second end of the flapper shaft can be supported on the valve housing via a bearing arrangement. In this way, a particularly precise mounting of the flap shaft on the valve housing can be set up. The position arrangement can have one or preferably two bearing bodies, in particular one or two graphite bushes.

Provision is preferably made for the bearing arrangement to have a further insert sleeve which is inserted in a sealing manner into a further through-opening in the valve housing. In this way, the location assembly can be easily and precisely attached to the valve housing. In addition, leakage between the valve housing and the additional insert sleeve can be avoided.

The additional insert sleeve can protrude through the additional through-opening. The valve flap can have a further recess which at least partially follows a contour of the further insert sleeve which projects into the valve housing. As a result, in a closed position, the valve flap can largely reduce a flow cross section of the valve housing, in particular almost completely prevent flow through the valve housing.

A support ring is preferably attached to the second end of the flap shaft for axial support on a bearing body of the bearing arrangement. An axial position of the flap shaft can be set up in a defined manner by means of the support ring. A spring element, which pretensions the flap shaft, typically causes the support ring to be pressed against the bearing body of the bearing arrangement.

The bearing arrangement particularly preferably forms a static seal for the second end of the flap shaft. A leak at the second end of the flap shaft can be avoided in a particularly effective and permanently reliable manner by means of a static seal. To form the static seal, the second end of the flap shaft can be encompassed in a cap-like manner by the further insert sleeve, an intermediate sleeve and/or a cover cap, with the aforementioned elements being fastened to one another or to the valve housing in a sealing manner.

An internal combustion engine with an exhaust system with a flap valve according to the invention as described above also falls within the scope of the present invention. The flapper valve can be part of a muffler arrangement of the exhaust system. In motor vehicles in particular, which have flap exhaust systems for use on the road and in sports, very high exhaust gas temperatures occur, so that the advantages of the thermally insulated radial seal are of particular importance. Alternatively, the flap valve can be part of an exhaust gas recirculation system of the exhaust system. Particularly high exhaust gas temperatures also occur in exhaust gas recirculation systems, so that the advantages of thermal insulation arranged radial seal appear particularly effective.

A motor vehicle, preferably a motorcycle, with an internal combustion engine according to the invention as described above also falls within the scope of the invention. By suitably arranging the internal combustion engine and the exhaust system on the motorcycle, the flap valve can be cooled particularly effectively, particularly in the area of the radial seal. As a result, the flap valve can be exposed to even higher exhaust gas temperatures.

Further advantages of the invention result from the description and the drawing. According to the invention, the features mentioned above and those detailed below can be used individually or collectively in any desired, expedient combination. The embodiments shown and described are not to be understood as an exhaustive list, but rather have an exemplary character for the description of the invention.

character list

• 1 ein erfindungsgemäßes Klappenventil mit einer Radialdichtung, die zwischen einer gehäusefesten Lagerbuchse und einem an einer Klappenwelle gehaltenen, die Lagerbuchse übergreifenden Ringteil angeordnet ist, in einer schematischen Schnittansicht;
• 2 eine vergrößerte Detailansicht des Klappenventils von 1 im Bereich der Radialdichtung;
• 3 ein erfindungsgemäßes Kraftfahrzeug in Form eines Motorrads mit einem erfindungsgemäßen Verbrennungsmotor aufweisend ein erfindungsgemäßes Klappenventil.

The invention is illustrated in the drawing and is explained in more detail using an exemplary embodiment. Show it:

• 1 a flap valve according to the invention with a radial seal, which is arranged between a bearing bush fixed to the housing and a ring part which is held on a flap shaft and overlaps the bearing bush, in a schematic sectional view;
• 2 an enlarged detail view of the flap valve of 1 in the area of the radial seal;
• 3 a motor vehicle according to the invention in the form of a motorcycle with an internal combustion engine according to the invention having a flap valve according to the invention.

1 shows a flap valve 10. The flap valve 10 has a valve housing 12 through which a flow can flow. A flap shaft 14 of the flap valve 10 protrudes through the valve housing 12. The flap shaft 14 extends along a longitudinal axis 15. The flap shaft 14 enters the valve housing 12 and exits the valve housing 12 at two through-openings 16, 18. A valve flap 20 is held on the flap shaft 14 . By rotating the flap shaft 14 with the valve flap 20, a flow cross section of the valve housing 12 can be changed.

The flap valve 10 has a bearing bush 22 . The flap shaft 14 protrudes through the bearing bush 22 . A first end 24 of the flap shaft 14 projects out of the bearing bush 22 facing away from the valve housing 12 . In the bearing bush 22 is a plain bearing 25, here in the form of a graphite bush, is arranged. The plain bearing 25 can be pressed into the bearing bush 22 . The flap shaft 14 is supported on the bearing bush 22 via the plain bearing 25 in the radial direction with respect to the longitudinal axis 15 . In principle, the plain bearing 25 is not in gas-tight contact with the flap shaft 14 .

A ring member 26 is attached to the first end 24 of the flap shaft 14 . The annular part 26 can be welded to the flap shaft 14 all around. The ring part 26 overlaps the bearing bush 22 radially on the outside. For this purpose, the ring part 26 can have a collar 28 which is designed to run around in the circumferential direction.

The area A off 1 with the ring part 26 and the bearing bush 22 is in 2 shown enlarged. The following is on 2 additionally referenced.

The flap valve 10 has a radial seal 30 . The radial seal 30 is arranged in the radial direction with respect to the longitudinal axis 15 between the bearing bush 22 and the ring part 26, in particular its collar 28. The radial seal 30 is arranged here so that it overlaps the slide bearing 25 in the axial direction. The radial seal 30 bears sealingly against the bearing bushing 22 and the annular part 26 in the radial direction. For this purpose, the bearing bush 22 has a radially outer sealing surface 32 . The ring part 26 has a radially inner sealing surface 34 . The sealing surface 34 is formed here on the collar 28 of the ring part 26 .

The radial seal 30 has a foot part 36 and two sealing wings 38 protruding from the foot part 36 . The foot part 36 is supported in the axial direction with respect to the longitudinal axis 15 on a shoulder 39 of the bearing bush 22 . The sealing wings 38 are spread apart in the radial direction by a spreading element 40 which runs around in the circumferential direction and is arranged between the sealing wings 38 . The sealing wings 38 are consequently pressed against the sealing surfaces 32 and 34 by the expanding element 40 .

The bearing bush 22 is attached to an insert sleeve 42 in a sealing manner. Here the bearing bush 22 and insert sleeve 42 are welded together. The insert sleeve 42 protrudes through the through-opening 16 of the valve housing 12. The insert sleeve 42 and the valve housing 12 are also tightly connected to one another, here welded to one another. The valve flap 20 has a recess 44 which follows a contour of the section of the insert sleeve 42 which projects into the valve housing 12 .

A torque introduction device 46 , here in the form of a pulley arrangement 48 , is arranged at the first end 24 of the flap shaft. The cable pulley arrangement 48 has a first, here flat, disk 50 and a second, here cranked, disk 52 . Between the two discs 50, 52 is a receiving groove 54 for a cable, not shown, such as the inner core of a cable, is formed. The two discs 50, 52 are firmly connected to one another, preferably welded to one another. Torque initiating device 46 may be attached to ring portion 26 . Here the first disc 50 is welded to the ring part 26 . Alternatively, the first and/or the second disc 50, 52 could be welded directly to the flap shaft 14 (not shown in detail).

The flap valve 10 has a bearing arrangement 56 for a second end 58 of the flap shaft 14 . The second end 58 of the flap shaft 14 is supported on the valve housing 12 via the bearing arrangement 56 . The flap shaft 14 is thus mounted at both ends.

The bearing arrangement 56 has a first and a second bearing body 60, 62, each in the form of a graphite bushing here. The first bearing body 60 is accommodated in a further insert sleeve 64 . The further insert sleeve 64 protrudes through the through-opening 18 of the valve housing 12. The further insert sleeve 64 and the valve housing 12 are tightly connected to one another, here welded to one another. The valve flap 20 has a further recess 66 which follows a contour of the section of the further insert sleeve 64 which projects into the valve housing 12 .

The second bearing body 62 is accommodated in an intermediate sleeve 68 . The intermediate sleeve 68 is tightly connected to the additional insert sleeve 64 . Here the intermediate sleeve 68 and the additional insert sleeve 64 are welded together. The two bearing bodies 60, 62 are spaced apart from one another in a defined manner via the intermediate sleeve 68.

A cover cap 69 overlaps the intermediate sleeve 68 and seals the layer arrangement 56 from the outside. The covering cap 69 can be welded to the intermediate sleeve 68 . The second end 58 of the flap shaft 14 is overlapped like a cap by the further insert sleeve 64, the intermediate sleeve 68 and the cover cap 69 of the position arrangement 56. The bearing arrangement 56 forms a static seal for the second end 58 of the flap shaft 14 by means of the aforementioned elements.

A support ring 70 is attached to the second end 58 of the flap shaft 14 . The support ring 70 can be pressed onto the flap shaft 14 or, preferably, welded. The support ring 70 bears against the second bearing body 62 of the bearing arrangement 56 in the axial direction.

The flap valve 10 has a spring element 72 . The spring element 72 prestresses the flap shaft 14 in relation to the valve housing 12 in the axial direction with respect to the longitudinal axis 15 . The annular part 26 is prestressed away from the valve housing 12 by means of spring learning 72 . The spring element 72 is designed here as a cylindrical helical spring. The spring element 72 is supported on the one hand on the torque introduction device 46, here on its first disk 50, from. On the other hand, the spring element 72 can be supported on a support element 73 (in a manner not shown in detail here). Alternatively, the spring element 72 can be supported on an intermediate element, not shown in detail, which can be attached to the support element 73 . A cable pull, also not shown in detail, for actuating the flap valve 10 can be guided on the intermediate element. The support element 73 is arranged on the outside of the valve housing 12 . The flap valve 10 can be held on an internal combustion engine or an exhaust system via the support element 73 . The support ring 70 is pressed against the second bearing body 62 in the axial direction by the prestressing of the spring element 72 . As a result, a defined contact and alignment of the flap shaft 14 with respect to the valve housing 12 is set up independently of thermal expansions.

3 shows a motor vehicle, namely a motorcycle 74. The motorcycle 74 has an internal combustion engine 76 with an exhaust system 78. FIG. The exhaust system 78 includes a flapper valve 10 as shown in FIGS 1 and 2 shown and described above. The flap valve 10 is part of a silencer arrangement 82 of the exhaust system 78 here. The silencer arrangement 82 can be connected to the internal combustion engine 76 via an exhaust pipe 80 of the exhaust system 78 .

Reference List

10

flap valve

12

valve body

14

flap shaft

15

longitudinal axis

16, 18

through-holes

20

valve flap

22

bearing bush

24

first end of the flap shaft 14

25

bearings

26

ring part

28

collar

30

radial seal

32

Sealing surface on the bearing bush 22

34

Sealing surface on the ring part 26

36

footboard

38

sealing wing

39

shoulder

40

spreading element

42

insert sleeve

44

withdrawal

46

Torque initiating device

48

sheave assembly

50

first slice

52

second disc

54

receiving groove

56

bearing arrangement

58

second end of the flap shaft 14

60

first bearing body

62

second bearing body

64

further insert sleeve

66

further withdrawal

68

intermediate sleeve

69

cover cap

70

support ring

72

spring element

73

support element

74

motorcycle

76

combustion engine

78

exhaust system

80

exhaust pipe

82

muffler assembly

Claims (16)

Having a flap valve (10) for an exhaust system (78) of an internal combustion engine (76). - a flow-through valve housing (12), - a flap shaft (14) on which a valve flap (20) is held for changing a flow cross section of the valve housing (12), - a bearing bush (22) from which a first end (24) of the flap shaft (14) protrudes, - A plain bearing (25) arranged between the flap shaft (14) and the bearing bush (22). - a ring part (26) which is fastened to the first end (24) of the flap shaft (14) and the bearing bush (22) engages radially on the outside circumferentially, - a radial seal (30), which is arranged between the bearing bush (22) and the ring part (26) and sealingly abuts the bearing bush (22) and the ring part (26) in the radial direction, for which purpose the bearing bush (22) has a radially outer lying sealing surface (32) and the ring part (26) has a radially inner sealing surface (34). flap valve (10). claim 1 , characterized in that the bearing bush (22) has a shoulder (39) on which the radial seal (30) is supported in the axial direction. Flap valve (10) according to one of the preceding claims, characterized in that the radial seal (30) has two sealing wings (38) projecting from a foot part (36) of the radial seal (30). Flap valve (10) according to one of the preceding claims, characterized in that a spring element (72) pretensions the flap shaft (14) in the axial direction relative to the valve housing (12). Flap valve (10) according to one of the preceding claims, characterized in that a torque introduction device (46) is provided at the first end (24) of the flap shaft (14). Flap valve (10) according to one of the preceding claims, characterized in that the plain bearing (25) is a graphite bush. flap valve (10). claim 6 , characterized in that the radial seal (30) and the slide bearing (25) are arranged overlapping in the axial direction. Flap valve (10) according to one of the preceding claims, characterized in that the bearing bush (22) is fixed to an insert sleeve (42) in a sealing manner. flap valve (10). claim 8 , characterized in that the insert sleeve (42) is inserted into a through-opening (16) of the valve housing (12) in a sealing manner. flap valve (10). claim 9 , characterized in that the insert sleeve (42) protrudes through the through-opening (16). Flap valve (10) according to one of the preceding claims, characterized in that a second end (58) of the flap shaft (14) is supported on the valve housing (12) via a bearing arrangement (56). flap valve (10). claim 11 , characterized in that the bearing arrangement (56) has a further insert sleeve (64) which is sealingly inserted into a further through-opening (18) of the valve housing (12). flap valve (10). claim 11 or 12 , characterized in that at the second end (58) of the flap shaft (14) a support ring (70) for axial support on a bearing body (62) of the bearing assembly (56) is attached. Flap valve (10) according to one of Claims 11 until 13 , characterized in that the bearing arrangement (56) forms a static seal for the second end (58) of the flap shaft (14). Internal combustion engine (76) with an exhaust system (78) with a flap valve (10) according to one of the preceding claims. Motor vehicle with an internal combustion engine (76). claim 15 .

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