DE102004040817B4 - Exhaust flap means - Google Patents

Abstract

Exhaust flap means for motor vehicles, with one in a housing (10) arranged exhaust flap (12), one with the exhaust flap (12) connected flap shaft (14) and one with the flap shaft (14) connected adjusting device (20) for pivoting the exhaust flap, wherein an output shaft (1) of the adjusting device (20) with the flap shaft (14) is aligned, and wherein the adjusting device (20) in the vicinity of the exhaust flap (12) is arranged, characterized in that the adjusting device (20) about a coupling (16) which can be coupled in and out during operation directly with the flap shaft (14) is connected, such that in decoupled State a heat transfer is avoidable.

Description

The The invention relates to an exhaust flap device for motor vehicles.

Especially at large volume Engines are known to turn off individual cylinders to operate in specific Driving situations to save fuel. To turn off even when Cylinders to ensure a sufficient back pressure in the exhaust line, Exhaust flaps are provided in individual exhaust pipes. With help the exhaust flaps can individual exhaust pipes are partially or completely closed. Further Such exhaust valves are provided to turn off even when Cylinders an engine noise to be able to simulate that the engine noise corresponds, if all Cylinders are turned on. To operate the exhaust valves, the directly in an exhaust pipe or in the exhaust pipe used casing are arranged, the exhaust valves are pivotable via flap shafts stored. With one end of the flap shaft is an adjusting device connected. The connection of the actuator with the valve shaft via a linkage or a Bowden cable, so that the adjusting device in a certain Distance to the exhaust system can be arranged. This is required because the high temperatures in the area of the exhaust line, the adjusting device would damage. The Provide a linkage or a Bowden cable, however, has the disadvantage that it is difficult is the exhaust flap in a well-defined angle or a to arrange given position, since the tolerances add up can and For example, by deformation length changes in the linkage or in the Bowden cable to a falsification to lead.

From the DE 100 34 489 A1 Now, an actuator for switching flaps is known, which is driven by an electric motor with a rotary magnet as a rotor. The drive shaft can be locked in this case in a certain position.

From the DE 103 21 653 B3 is also an electric actuator for actuators known which is connected via a coupling with the output shaft.

However, the closest prior art forms the EP 1 245 820 A1 , which discloses an exhaust valve device whose actuator is disposed in the vicinity of the exhaust valve.

Of the Disadvantage of these embodiments however, lies in the high heat load the components, in particular the adjusting device.

In order to It is an object of the invention to provide an exhaust valve device, through the exhaust flap in a simple manner in different positions can be arranged exactly, with too high heat load should be avoided.

The solution The object is achieved according to the invention by the features of the claim 1.

The Setting device is arranged such that an output shaft the adjusting device is aligned with the flap shaft. The adjusting device is thus close arranged the exhaust flap and not via a linkage or a Bowden cable connected to the valve shaft.

According to the invention is between the adjusting device and the flap shaft one in operation on and provide disengageable coupling. The coupling is preferably designed such that in a simple manner a coupling and decoupling, d. H. a connection of the output shaft with the flap shaft or a release the connection possible is. This has the advantage that it is possible, for example, only for pivoting the exhaust flap a connection between the Make output shaft and the valve shaft. Thus, too only during this short period of heat transfer over the Damper shaft to the output shaft and thus to the actuator.

Around when solved Clutch ensure that the position of the exhaust flap does not change due to the exhaust gas flow, a holding element is preferably provided. In the holding element can For example, it is a braking device, a locking device or the like acting directly or indirectly with the Valve shaft cooperates or is engaged as soon as a Uncoupling takes place.

at the adjusting device is preferably an electric motor. This has the advantage that, for example, by providing a stepper motor an exact pivoting of the valve shaft is possible. Furthermore, with a shaft of the electric motor, a position sensor for detection a rotation angle can be easily connected.

Preferably is additional or instead of the coupling between the output shaft and the flap shaft an intermediate element for heat decoupling intended. This can be an intermediate element of a Trade material that has a low thermal conductivity.

In order to shield also radiant heat from the actuator as possible, is preferably between the actuator and the housing in which the exhaust valve is arranged, a Wärmeab screen element, for example in the form of a shielding plate provided.

following the invention will be described with reference to a preferred embodiment explained in more detail in the accompanying drawings.

It demonstrate:

1 a schematic perspective view of the exhaust valve device, and

2 an enlarged view of the connection between the actuator and the flap shaft.

The exhaust valve device has a housing 10 on, in which an exhaust flap 12 is arranged. The exhaust flap 12 is in the illustrated embodiment with a flap shaft 14 connected and over the flap shaft 14 stored on one side. The flap shaft 14 is about a clutch 16 ( 2 ) with an output shaft 18 and an adjusting device designed in particular as an electric motor 20 connected.

Here is the output shaft 18 According to the invention, arranged such that it faces the flap shaft 14 is aligned or coaxially arranged.

The electric motor 20 is in the illustrated embodiment of an L-shaped support element 22 attached. The carrier element 22 at the same time serves as a shielding element to heat radiation emitted from the exhaust line relative to the electric motor 20 shield.

The coupling 16 , in the 2 is shown in engaged position, to heat transfer from the valve shaft 14 on the output shaft 18 to be disconnected. In the uncoupled state, a pivoting of the exhaust flap 12 due to the through the housing 10 To avoid flowing exhaust stream is not shown holding member, such as a brake provided. The brake, for example, acts directly on the valve shaft 14 ,

For protection is the clutch 16 with a sleeve 24 ( 1 ) surround.

Claims (5)

Exhaust flap device for motor vehicles, with one in a housing ( 10 ) arranged exhaust flap ( 12 ), one with the exhaust flap ( 12 ) connected flap shaft ( 14 ) and one with the flap shaft ( 14 ) associated actuating device ( 20 ) for pivoting the exhaust flap, wherein an output shaft ( 1 ) the actuator ( 20 ) with the flap shaft ( 14 ) is aligned, and wherein the adjusting device ( 20 ) near the exhaust flap ( 12 ), characterized in that the adjusting device ( 20 ) via a coupling which can be coupled in and out during operation ( 16 ) directly with the flap shaft ( 14 ) is connected, such that in the decoupled state heat transfer is avoidable. Exhaust valve device according to claim 1, characterized by a holding element for fixing the position of the exhaust flap ( 12 ) with disengaged clutch ( 16 ). Exhaust valve device according to one of the claims 1 or 2, characterized in that the adjusting device ( 20 ) has an electric motor. Exhaust valve device according to one of claims 1-3, characterized in that between the output shaft ( 18 ) and the flap shaft ( 14 ) is provided an intermediate element for heat decoupling. Exhaust valve device according to one of claims 1-4, characterized in that between the adjusting device ( 20 ) and the housing ( 10 ) a heat shielding element ( 22 ) is provided.