Operating device for a motor vehicle, comprising an operating element mounted by means of an aerostatic air bearing

Abstract

The invention relates to an operating device (1) for a motor vehicle, comprising an operating element (10) and a bearing shell (20) which surrounds some portions of the operating element (10) and on which the operating element (10) is mounted by means of an aerostatic air bearing so as to be freely rotatable about at least one axis of rotation (X, Y, Z), wherein a pressure chamber (31) that is delimited in portions by the bearing shell (20) is provided on a side of the bearing shell (20) that is remote from the operating element (10), into which pressure chamber an air feed (32) opens, wherein the bearing shell (20) is air-permeable and air can be conveyed as a lubricating medium via the air feed (32) and the pressure chamber (30) through the bearing shell (20) into an air cushion between the operating element (10) and the bearing shell (20).

Description

[0001] Operating device for a motor vehicle with an operating element mounted by aerostatic air bearings

[0002] Description:

[0003] The invention relates to an operating device for a motor vehicle with an operating element mounted by an aerostatic air bearing.

[0004] In principle, a large number of operating devices for motor vehicles are known from the state of the art, which are mounted in a variety of ways and are used, for example, to operate the vehicle's infotainment system.

[0005] However, a bearing based on contact between the bearing partners usually produces a stick-slip effect on the one hand, and a resistance – albeit slight – on the other, which is often noticeable to the operator when used in an operating device. If the operating device is intended to record precise, and especially small, inputs, this is made more difficult by the stick-slip effect.

[0006] Furthermore, the contact points or movement paths of bearing elements that directly touch the operating element of the operating device can leave permanent marks on the operating element that are perceptible to the operator.

[0007] In addition to various bearings that are based on direct contact between the bearing partners or on direct contact between the bearing partners and intermediate bearing elements, so-called gas or air bearings are also known, in which gas or air is used as a lubricating medium between the bearing partners.

[0008] In the present case, reference is made to air as a lubricant, whereby this is understood to include any gas suitable as a lubricant.

[0009] Air or gas bearings can be further divided into aerostatic and aerodynamic bearings, where the two bearings moving relative to each other are separated by a thin film of air or a thin air cushion. This ensures stick-slip and friction-free movement of the bearings.

[0010] Aerostatic bearings build up the necessary air film themselves when the bearing components move, so no air supply is required, but at least inertial friction is generated. In contrast, an aerodynamic bearing relies on a constant supply of air to fulfill its bearing function.

[0011] However, air bearings are atypical for operating devices, since an aerostatic bearing usually does not generate sufficient movement to build up the air film, and an aerodynamic bearing requires a constant supply of air, which requires additional components and is therefore cost-intensive.

[0012] Furthermore, the constant air supply also creates unfavorable acoustic effects, which is particularly disadvantageous for control devices in vehicles.

[0013] Irrespective of contact-based bearings and air bearings, a further disadvantage for operating devices is that haptic feedback or locking positions are often desired, which contradicts or excludes the possibility of fine and, in particular, free operability.

[0014] The invention is therefore based on the object of overcoming the aforementioned disadvantages and providing a smooth operating device suitable for fine operating inputs.

[0015] This problem is solved by the combination of features according to patent claim 1.

[0016] According to the invention, an operating device for a motor vehicle is therefore proposed. For this purpose, the operating device has an operating element and a bearing shell which partially surrounds or receives the operating element and on which the operating element is mounted by an aerostatic air bearing so that it can rotate freely, i.e. without limitation or stop, about at least one axis of rotation. On a side of the bearing shell facing away from the operating element, a pressure chamber is provided and in particular arranged or formed, which is partially delimited by the bearing shell and into which an air supply opens, which can be understood, for example, as a hose or pressure coupling. The bearing shell is permeable to air and, as explained below, is made in particular from a porous material and is therefore permeable to air.According to the invention, air can be conveyed as a lubricating medium via the air supply and the pressure chamber through the air-permeable bearing shell into an air cushion between the operating element and the bearing shell.

[0017] In addition, it should be noted that preferably at least one displacement sensor, embodied, for example, as an optical sensor, can be provided, which is designed to detect, in particular contactlessly, a distance traveled by the operating element or a distance on a surface of the operating element about the at least one rotational axis, by which the operating element has been rotated about the rotational axis. "Distance" here refers to both the distance and the course of the distance.

[0018] Furthermore, and in particular when using a transparent material for the operating element, a lighting element can also be provided which is designed to couple light into the operating element and thereby illuminate it.

[0019] According to a further development of the invention, it can further be provided that the pressure chamber has a pressure outlet which is designed to be closable both by a plug which closes the pressure outlet in a pressure-tight manner and by an insert which can be referred to as a flow insert for flow control.

[0020] Furthermore, the plug or insert can be arranged in the pressure outlet and thus be part of the operating device.

[0021] An insert for flow control can be arranged in the pressure outlet and extend into the pressure chamber, so that at least one flow guide element and / or at least one flow channel can be formed in the pressure chamber by the insert. The insert, or its section extending into the pressure chamber, can also extend to the opening of the air supply into the pressure chamber and, if necessary, also connect to it in a pressure-tight manner.

[0022] Because both a plug and a flow insert can be inserted into the pressure outlet, the control device can be adapted to specific requirements and implemented in various variants according to a modular principle. For example, if the temporary fixation of the control element in the bearing shell (as explained below) is desired, a flow insert can be provided. If this function is not required, the pressure outlet is closed with the plug.

[0023] Furthermore, it can be provided that the operating device further comprises an actuator for closing and opening the pressure outlet, so that the closed pressure outlet is pressure-tight and fluidly closed and the open pressure outlet can be flowed through by fluid, specifically air or gas. Based on this, various variants can be implemented to create a negative pressure on the bearing shell and thereby temporarily fix the operating element in the bearing shell. For example, the pressure chamber with the air supply and the pressure outlet can be designed as a Venturi nozzle. Alternatively, the actuator itself can be designed as a Venturi nozzle. Furthermore, an insert or flow insert inserted into the pressure outlet can be designed as a Venturi nozzle.In each of the variants, the air flowing in at the air supply and out at the pressure outlet, controlled by the actuator, can generate a flow through the bearing shell into the pressure chamber and a negative pressure that fixes the control element to the bearing shell.

[0024] Although in the described variant an actuator and a separate Venturi nozzle or an actuator arranged outside the pressure outlet, which is designed as a Venturi nozzle, can be provided, a further variant of the invention provides that the operating device further comprises such an actuator for closing and opening the pressure outlet, wherein the actuator itself is designed as an insert or flow insert inserted into the pressure outlet and at the same time as a Venturi nozzle, so that in turn the air flowing in at the air supply and flowing out at the pressure outlet can be controlled by the actuator and a flow through the bearing shell into the pressure chamber and a negative pressure can be generated that fixes the operating element to the bearing shell. In this case, therefore, an actuator is not designed as a Venturi nozzle or flow insert and arranged at the pressure outlet, but in the pressure outlet.

[0025] In both variants, a respective flow insert on a side of the pressure outlet facing away from the operating element preferably has a form factor or external shape identical to the plug.

[0026] Furthermore, in both variants, the operating device can further comprise a control device for controlling the actuator, which is designed to control the actuator to generate a negative pressure for locking the operating element and / or for generating haptic feedback on the operating element and / or for simulating locking steps on the operating element. Each of the variants is to be understood as temporarily fixing the operating element to or in the bearing shell.

[0027] By locking the control element, the user or operator is shown and signalled that an operating input is currently not possible, i.e. for the duration of the lock.

[0028] Haptic feedback can, for example, be used to specifically vibrate the control element, indicating to the operator that a certain position has been reached or that a control input has been successfully completed. Since, for example, a detent on the control element is helpful when entering information in simple lists or in a matrix, as it allows the operator to see when jumping between the various list or matrix fields, a detent on the control element can be simulated depending on a display or the vehicle function to be operated. This detent temporarily and briefly locks the control element after a predetermined distance, e.g., for 500 ms.

[0029] To provide air or compressed air or, as already mentioned in the introduction, a gas in general, the operating device can also further comprise a pump for providing a continuous air flow to the air supply, wherein the pump can be connected directly, i.e. immediately, to the air supply or via a flow channel and, for example, a hose. In this case, it is already sufficient and preferably provided if the pump provides a pressure of less than 1 bar and in particular between 0.3 and 0.8 bar, wherein a volume flow of less than 10 l / min and in particular between 3 and 6 l / min can be generated by this or is sufficient for the functions mentioned.

[0030] A simple diaphragm pump, for example, can serve as the pump, although it is advantageous if the pump can be switched with regard to its flow direction. When switching the flow direction, a variant can be implemented in which no Venturi nozzle is necessary, but rather the pump directly generates the negative pressure that implements the above-mentioned functions, which in turn enables the control element to be locked and / or haptic feedback to be generated on the control element and / or detent steps to be simulated on the control element. A further variant is advantageous in which the air supply and the pressure outlet are identical to one another, so that, following the modular principle, the pump can also be connected to the pressure outlet and the air supply can be closed off with a plug or insert.

[0031] According to a further variant, the bearing shell can have a concave wall section for receiving and gripping the operating element, which in particular corresponds to the outer surface of the operating element and more preferably corresponds to a spherical segment. The wall section has a constant or uniform wall thickness and / or a locally limited material weakening in a geometric center of the wall section and / or a main bearing point. The locally limited material weakening can preferably extend in the form of a recess from the side of the bearing shell facing away from the operating element to the side facing the operating element, wherein the recess is in turn preferably conical, truncated cone-shaped, or channel-shaped. The wall thickness, which may be constant or uniform with the exception of the material weakening, is also preferably less than 5 mm and in particular in a range between 2 and 4 mm.

[0032] The recess or material weakening serves to provide an increased air flow in the main bearing point of the control element in the bearing shell compared to the adjacent areas.

[0033] Regarding the material of the bearing shell, it can be made of graphite, aluminum, or plastic, for example. The air permeability of the bearing shell can be achieved, for example, by a plurality of holes arranged in a predetermined pattern, but preferably and optionally additionally by a porosity of the material or the bearing shell. Although the air cushion for lubrication or mounting of the control element in the bearing shell could also be realized through a single hole, a porous bearing shell has the particular advantage of also acting as a silencer, so that the air flowing out of the bearing shell generates little or no noise.

[0034] With regard to the operating element, which may, for example, be cylindrical or disc-shaped or spherical or cylindrical or frustoconical, it should be noted that this may in particular be made of steel or glass or plastic, wherein an operating element made of glass or plastic is further preferably transparent or at least translucent and thus allows light to pass through, enabling illumination.

[0035] Furthermore, the operating device can have a housing into which the bearing shell can be inserted and which delimits the pressure chamber in sections, so that the pressure chamber is preferably formed by the bearing shell and the pressure chamber. The housing has a first section for receiving the bearing shell and a second section for holding the operating element on the bearing shell, wherein holding the operating element in the bearing shell means that the operating element is movable, for example rotatable, on or in the bearing shell while maintaining a predetermined air gap for forming the air cushion. For this purpose, a first clamping element for fixing the bearing shell in the housing is arranged in and / or on the second section. Additionally or alternatively, a second clamping element for holding the operating element in the housing is arranged in and / or on the second section.

[0036] In the second section, a pressure equalization channel can also be provided, in or on which a silencer can be formed or arranged, so that air flowing from the second section into the pressure chamber can be sucked in through the pressure equalization channel and air flowing from the pressure chamber into the second section can escape through the pressure equalization channel.

[0037] If a housing is provided, this can also preferably be spring-loaded in exactly one direction, so that the operating element is spring-loaded together with the housing when pressure or an input is applied to the operating element, which can be detected by a sensor and evaluated as an operating input.

[0038] The features disclosed above can be combined as desired, as long as this is technically possible and they do not contradict each other.

[0039] Other advantageous developments of the invention are characterized in the subclaims or are presented in more detail below, together with the description of the preferred embodiment of the invention, with reference to the figures. They show:

[0040] Fig. 1 shows an operating device in section;

[0041] Fig. 2 shows a bearing shell of an operating device in section.

[0042] The figures are schematic examples. Identical reference numerals in the figures indicate identical functional and / or structural features, whereby the bearing shell 20 according to Figure 2 can correspond in particular to the bearing shell 20 of the operating device 1 according to Figure 1.

[0043] Figure 1 shows a perspective and sectioned view of an operating device 1 for a motor vehicle. An operator can make operating inputs by rotating a spherical operating element 10 about the X, Y, and Z axes, thereby operating, for example, an infotainment system of the motor vehicle. To allow fine operating inputs without noticeable resistance, the operating element 10 is mounted on an air bearing. For this purpose, an air-permeable bearing shell 20 made of porous material surrounds the operating element 10 in sections, so that the bearing shell 20 has a wall section 21 corresponding to the operating element 10 and correspondingly concave, and an air cushion can be formed between the wall section 21 and the operating element 10.The air cushion serving for the bearing is supplied with air from a pressure chamber 31 through the air-permeable bearing shell 20, wherein the pressure chamber 31 is formed on a side of the bearing shell 20 facing away from the operating element 10.

[0044] To provide the air in the pressure chamber 31, an air supply 32 opens into it, to which a diaphragm pump can be connected, for example, via a hose line.

[0045] Since the air from the pressure chamber 31 does not flow through the bearing shell 20 only at one or a small number of points, but rather a substantially uniform flow through the entire wall section 21 is realized by the porous material and the bearing shell 20 itself acts like a silencer due to the porous material, the air can be provided to the control element 10 or for the air cushion with extremely low noise.

[0046] However, in order to be able to support the operating element 10 in the main load direction as best as possible, as can be clearly seen in Figure 2, a conical recess is provided as a locally limited material weakening 22 at a main bearing or main support point of the bearing shell 20 according to Figure 2, ie in the geometric center of the wall section 21 of the bearing shell 20 shown in Figure 2, so that the bearing shell 20 in the area of ​​the material weakening 22 can be flowed through more easily and more strongly by air than in the adjacent or surrounding area of ​​the wall section 21.

[0047] According to the embodiment of the operating device 1 shown in Figure 1, it further comprises a housing 40 in which the bearing shell 20 is received in a first section 41 and fixed by a first clamping element 43. Accordingly, the pressure chamber 31 is completely defined or formed by the housing 40 and the bearing shell 20.

[0048] The operating element 10, which is designed as a ball, is also surrounded by the housing 40 up to a center plane of the operating element 10, is received in a second section 42 of the housing 40 and is held therein by a second clamping element 44, so that the operating element 10 cannot be removed from the housing 40 without releasing the second clamping element 44, but the intended air cushion can be formed between the operating element 10 and the bearing shell 20.

[0049] In order to be able to record the path traveled on the surface of the operating element 20 in terms of the path course and the distance traveled, a path sensor 46 designed as an optical sensor and thus operating without contact is also arranged in the second section 42 of the housing 40, by means of which the operating inputs made by the operator on the operating element 10 can be translated into corresponding electronic signals and transmitted to a control unit of the motor vehicle.

[0050] Since acoustics play a key role, particularly in motor vehicle use, and air flowing through the bearing shell 20 should not be acoustically perceptible to the operator, a pressure equalization channel 45 is also provided in the second section 42 of the housing 40. Compared to a seal between the second clamping element 44 and the operating element 10, the pressure equalization channel 45 has a lower flow resistance, so that a large portion of the air flowing into or out of the second section 42 will flow through the pressure equalization channel 45.

[0051] As can be seen in Figure 1, an air supply 32 opens into the pressure chamber 31, wherein a pressure outlet 33 is also provided, which is closed with a plug 34. The pressure outlet 33 and the air supply 32 or a connection for connecting the air supply

[0052] 32 must be identical to the pressure chamber, so that the air supply 32 designed as a hose coupling can also be connected to the pressure outlet

[0053] 33 could be screwed in.

[0054] A further aspect of the invention can be realized by the pressure outlet 33, since it is preferably designed to accommodate both the plug 34 and an alternative, but not shown, flow insert. The flow insert or insert can form a Venturi nozzle, through which—controlled by an actuator (not shown)—a negative pressure can be generated that attracts the operating element 10 instead of an overpressure feeding the air cushion in the pressure chamber, so that the operating element 10 can be sucked onto the bearing shell 20 and thus temporarily fixed on or in it.

[0055] Such temporary fixation enables various functions that are typically impossible with air bearings. For example, by appropriately controlling the actuator or the Venturi nozzle, the control element 10 can be locked, haptic feedback—such as vibration—can be generated on the control element 10, and detent steps on the control element 10 can be simulated.

[0056] * * * * *

Claims

Patent claims 1. Operating device (1) for a motor vehicle, comprising an operating element (10) and a bearing shell (20) which partially surrounds the operating element (10) and on which the operating element (10) is mounted by an aerostatic air bearing so as to be freely rotatable about at least one axis of rotation (X, Y, Z), wherein on a side of the bearing shell (20) facing away from the operating element (10), a pressure chamber (31) is provided which is partially delimited by the bearing shell (20), into which chamber an air supply (32) opens, wherein the bearing shell (20) is designed to be permeable to air, and air can be conveyed as a lubricating medium via the air supply (32) and the pressure chamber (30) through the bearing shell (20) into an air cushion between the operating element (10) and the bearing shell (20).

2. Operating device according to claim 1, wherein the pressure chamber (31) has a pressure outlet (33) which is designed to be closable both by a plug (34) which closes the pressure outlet (33) in a pressure-tight manner and by an insert for flow control.

3. Operating device according to the preceding claim, further comprising an actuator for closing and opening the pressure outlet (33), wherein the pressure chamber (31) with the air supply (32) and the pressure outlet (33) is designed as a Venturi nozzle, or the actuator is designed as a Venturi nozzle, or an insert inserted into the pressure outlet (33) is designed as a Venturi nozzle, so that in each case by the Air flowing in through the air supply (32) and out through the pressure outlet (33) is controlled by the actuator, a flow through the bearing shell (20) into the pressure chamber (31) and a negative pressure can be generated which fixes the operating element (10) to the bearing shell (20).

4. Operating device according to claim 2, further comprising an actuator for closing and opening the pressure outlet (33), wherein the actuator is designed as an insert inserted into the pressure outlet (33) and as a Venturi nozzle, so that by the air flowing in at the air supply (32) and flowing out at the pressure outlet (33) controlled by the actuator, a flow through the bearing shell (20) into the pressure chamber (31) and a negative pressure fixing the operating element (10) to the bearing shell (20) can be generated.

5. Operating device according to claim 3 or 4, comprising a control device for controlling the actuator, which is designed to control the actuator to generate a negative pressure for locking the operating element (10) and / or for generating haptic feedback on the operating element (10) and / or for simulating locking steps on the operating element (10).

6. Operating device according to one of the preceding claims, further comprising a pump for providing a continuous air flow at the air supply (32).

7. Operating device according to one of the preceding claims, wherein the bearing shell (20) for receiving and encompassing the operating element (10) has a concave wall section (21) which has a constant wall thickness and / or a locally limited material weakening (22) in a geometric center of the wall section (21).

8. Operating device according to one of the preceding claims, wherein the bearing shell (20) is made of graphite or aluminum or plastic, wherein the bearing shell (20) has a plurality of holes arranged according to a predetermined pattern and / or is porous, wherein the operating element (10) is made of steel or glass or plastic.

9. Operating device according to one of the preceding claims, further comprising a housing (40) into which the bearing shell (20) can be inserted and which delimits the pressure chamber (31) in sections, wherein the housing (40) has a first section (41) for receiving the bearing shell (20) and a second section (42) for holding the operating element (10) on the bearing shell (20), wherein in and / or on the second section (42) a first clamping element (43) for fixing the bearing shell (20) in the housing (40) is arranged and / or wherein in and / or on the second section (42) a second clamping element (44) for holding the operating element (10) in the housing (40) is arranged.

10. Operating device according to the preceding claim, wherein a pressure equalization channel (45) is provided in the second section (42), through which air flowing from the pressure chamber (31) into the second section (42) can escape and air sucked from the second section (42) into the pressure chamber (31) can flow. * * * * *

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