Flap device and drive system with such a flap device, as well as a vehicle with such a drive system

Abstract

Flap device (1) for controlling a gas flow through a pipeline (2), with a flap (3) connected to a shaft (4), at least one bearing (5, 6) for the shaft (4), an actuator (8) for actuating the flap (3) and a wire pressing cushion (7) as a damping element, characterized in that the wire pressing cushion (7) is arranged between the actuator (8) and the shaft (4), wherein the arrangement is designed such that the wire pressing cushion (7) only transmits axial forces between the shaft (4) and the actuator (8) and the wire pressing cushion (7) is arranged in a frictional connection between the actuator (8) and the shaft (4).

Description

[0001] The invention relates to a flap device for controlling a gas flow through a pipeline according to the type defined in the preamble of claim 1. Furthermore, the invention relates to a drive system with such a flap device and to a vehicle with such a drive system.

[0002] DE 10 2010 047 464 A1 describes a fastening arrangement in which a vibration-loaded component, for example, a damper flap in an exhaust pipe, is damped via a damping element between the flap and an actuator. The cited document proposes using a wire mesh as the damping element, which transmits both radial and axial forces and is capable of damping a pivoted flap as a temperature-stable damping element. This makes it possible, in principle, to use it, for example, in damper flaps in exhaust pipes of internal combustion engine drive systems, such as those used in vehicles.

[0003] Similar to a conventional spring, a simple wire mesh has a relatively low damping effect, which primarily dampens low-frequency noise from the flap, thus preventing rattling. A simple wire mesh, similar to a spring, has little effect on high-frequency excitations, for example, above 500 Hz.

[0004] For this reason, DE 10 2017 117 289 A1 proposes the use of a wire mesh pressed part or a so-called wire pressed cushion. This also allows the damping of the high-frequency squeaking noises mentioned above, which can be caused, for example, by so-called slip-stick effects, i.e., a brief persistence in static friction, a break into sliding friction, a renewed persistence in static friction, and so on. In this document, a wire pressed cushion is pressed into a cavity in the bearing area in such a way that it is compressed both in the axial direction and, due to its elasticity, in the radial direction, thus providing damping. The disadvantage of this design is that the compression, especially in the radial direction, ultimately increases friction because radial force components press the flap or a shaft on which the flap is mounted radially against the bearings.This creates a comparatively high level of friction, which further increases the slip-stick effects mentioned above, which in turn can lead to high-frequency squeaking noises.

[0005] DE 10 2010 055 382 A1, DE 10 2018 206 791 A1, and DE 10 2018 204 431 A1, each considered individually, show a flap device for controlling a gas flow through a pipeline, comprising a flap connected to a shaft, at least one bearing for the shaft, an actuator for actuating the flap, and a wire compression cushion as a damping element. The wire compression cushion is arranged between the actuator and the shaft, with the arrangement being designed such that the wire compression cushion only transmits axial forces between the shaft and the actuator.

[0006] The object of the present invention is to provide an improved flap device which avoids the aforementioned disadvantages.

[0007] According to the invention, this object is achieved by a flap device having the features of claim 1, and in particular in the characterizing part of claim 1. Advantageous embodiments and further developments emerge from the dependent claims. Furthermore, claim 4 specifies a drive system with such a flap, and claim 5 specifies a vehicle with such a drive system.

[0008] In the valve device according to the invention, the wire pressing cushion is arranged between the actuator and the shaft to which the valve is connected. The arrangement is designed such that the wire pressing cushion only transmits axial forces between the shaft and the actuator. The wire pressing cushion is therefore suitable for compensating for assembly and manufacturing tolerances between the actuator and the valve shaft. In particular, angular errors between the actuator and the valve shaft are also compensated for. Because the wire pressing cushion only transmits forces in the axial direction, always relative to the valve shaft, the valve shaft is pressed into the axial bearing. However, because no radial force component is transmitted, the valve shaft is prevented from pressing radially against its radial bearings, which are typically arranged opposite one another on either side of the pipeline.This design allows for very low friction and thus ultimately reduces the slip-stick effect. This effectively prevents squeaking caused by this effect, and the wire-pressed cushion also efficiently dampens high-frequency excitations, i.e., excitations with a frequency of more than 500 Hz, which are caused, for example, but not exclusively, by the aforementioned slip-stick effect.

[0009] The wire pressing cushion is arranged force-fitting between the actuator and the shaft in order to press the shaft into the axial bearing, but not to transmit radial forces, as described above.

[0010] A particularly advantageous development of the flap device according to the invention further provides that the wire pressing cushion is arranged on the side of a radial and axial bearing of the shaft, while on the opposite side of the pipeline, the shaft is accommodated in a radial bearing. Thus, the wire pressing cushion is located directly on the side of the portion of the radial and axial bearing that acts as an axial bearing, resulting in a compact and efficient structure in which the part of the shaft that interacts with the axial bearing is pressed directly in the axial direction via the wire pressing cushion, thus damping the structure in the desired manner.

[0011] In principle, any type of actuator is suitable. However, according to an extremely advantageous development of the concept, the actuator is designed as an electric actuator, which moves the flap to the desired position according to a command from a control and / or regulation system.

[0012] According to the invention, a drive system can be provided that is equipped with an internal combustion engine, wherein the flap of the flap device is designed as a damper flap in an exhaust pipe of the internal combustion engine. In these applications in particular, the damping of both low-frequency and high-frequency squeaking and rattling noises is particularly useful. The use of a wire compression cushion ideally enables this, even at correspondingly high temperatures, since the wire compression cushion allows damping largely independent of the temperature level, especially at the high temperatures present in the exhaust gas of an internal combustion engine.

[0013] The drive system with the internal combustion engine can preferably be provided as the internal combustion engine drive system of a vehicle, for example, a passenger car, a commercial vehicle, a bus, or the like. In principle, it can also be used in other vehicles, such as rail vehicles or watercraft.

[0014] Further advantageous embodiments of the flap device according to the invention also emerge from the exemplary embodiment which is illustrated in more detail below with reference to the figure.

[0015] The only attached figure shows a schematic representation of a flap device according to the invention.

[0016] The figure shows a flap device 1, such as can be used for a backflow flap in an internal combustion engine, for example in a vehicle. The actual flap 3 is arranged in an exhaust pipe 2. This is firmly connected to a shaft 4, which projects through the pipe of the pipe 2 in the axial direction a of the shaft 4, which is typically perpendicular to the longitudinal direction of the pipe 2. In the illustration at the bottom of the figure there is a radial bearing 5 for the shaft 4, while in the figure at the top there is a combined radial and axial bearing 6 for the shaft 4. The shaft 4 is then connected on its side facing away from the pipe 2 via a wire press cushion 7 to an actuator 8, for example an electrical one.

[0017] The connection is implemented in such a way that the wire press cushion 7 sits in a frictional connection between the actuator 8 and the shaft 4 of the flap 3. The wire press cushion 7 compensates for assembly and manufacturing tolerances, in particular angular errors between the actuator 8 and the flap 3 or its shaft 4. The wire press cushion 7 only transmits axial forces in order to press the shaft 4 of the flap 3 into the axial bearing portion of the combined radial and axial bearing 6. No radial force components occur that press the shaft 4 of the flap 3 radially against the radial bearing 5 and the radial portion of the combined radial and axial bearing 6. This reduces friction and prevents the occurrence of a possible slip-stick effect.In addition to damping low-frequency flap noise, which can already be very effectively damped by an optional spring (not shown here), the wire compression cushion 7 can also be used to dampen high-frequency excitations with frequencies above 500 Hz, against which the spring would have no effect. By preferably replacing the spring with the wire compression cushion 7, ideal damping can be achieved with an appropriate design of the wire compression cushion.

[0018] When designing the wire compression cushion 7, it is important to ensure that the necessary spring force is achieved to reliably press the flap 3 or its shaft 4 into the axial bearing, and that the wire compression cushion 7 has sufficient volume to dissipate the energy of the high-frequency vibrations that are to be damped. By compensating for the angular tolerances between the actuator 8 and the flap 3 or its shaft 4 and eliminating the transmission of radial forces, friction is reduced accordingly, as already mentioned, which leads to a reduction in slip-stick effects and thus to a further reduction in squeaking noises.

Claims

[1] Flap device (1) for controlling a gas flow through a pipeline (2), with a flap (3) connected to a shaft (4), at least one bearing (5, 6) for the shaft (4), an actuator (8) for actuating the flap (3) and a wire press cushion (7) as a damping element, characterized by that the wire pressing cushion (7) is arranged between the actuator (8) and the shaft (4), wherein the arrangement is designed such that the wire pressing cushion (7) only transmits axial forces between the shaft (4) and the actuator (8) and the wire pressing cushion (7) is arranged in a frictional connection between the actuator (8) and the shaft (4). [2] Flap device (1) according to claim 1, characterized by that the wire pressing cushion (7) is arranged on the side of a radial and axial bearing (6) of the shaft (4), while on the opposite side of the pipe (2) the shaft (4) is received in a radial bearing (5). [3] Flap device (1) according to claim 1 or 2, characterized by that the actuator (8) is designed as an electrical actuator. [4] Drive system with an internal combustion engine and a flap device (1) according to one of claims 1 to 3, wherein the flap (3) is designed as a damper flap in a pipeline designed as an exhaust pipe. [5] Vehicle having a drive system with an internal combustion engine according to claim 4.

Images