METHOD FOR PRODUCING A DIAPHRAGM FOR AN ULTRASONIC SENSOR, AND DIAPHRAGM FOR AN ULTRASONIC TRANSDUCER

Abstract

A method for producing a diaphragm for an ultrasonic sensor. In the method, a diaphragm body made of metal material is first provided. Next, an external surface region of the diaphragm body is degreased. The external surface region of the diaphragm body is then pickled. To pre-activate the subsequently applied second passivation layer, a first passivation layer is also deposited on the external surface region as a first layer.

Claims

1-16. (canceled)

17. A method for producing at least one vehicle component, the method comprising the following steps: providing the vehicle component including an external surface made of metal material; degreasing the external surface region of the vehicle component; pickling the external surface region of the vehicle component; applying a second passivation layer to the external surface region of the vehicle component as a second layer; wherein, to pre-activate the subsequently applied second passivation layer, a first passivation layer is deposited on the external surface region as a first layer, using hexafluorotitanic acid.

18. The method as recited in claim 17, wherein the vehicle component produced is a diaphragm for an ultrasonic sensor.

19. The method as recited in recited claim 17, wherein the pickling of the external surface region and the depositing of the first passivation layer on the external surface region as the first layer are carried out simultaneously, in a pickling-passivation step.

20. The method as recited in claim 17, wherein a primer layer is applied to the second passivation layer as a third layer for protecting the metal material against corrosion.

21. The method as recited in claim 17, wherein, in the pickling, the degreased external surface region is treated with a chromium-free pickle liquor based on hydrogen fluoride and/or dihydrogen sulfate and/or trihydrogen phosphate, in a dipping process or in a spraying process.

22. The method as recited in claim 20, wherein a polyurethane-based wet coating is applied to the primer layer as a fourth layer.

23. A diaphragm for an ultrasonic transducer, comprising: a diaphragm body made of metal material; a second passivation layer arranged on an external, pickled surface region of the diaphragm body as a second layer, wherein to pre-activate the second passivation layer, a first passivation layer is arranged on the external, pickled surface region as a first layer.

24. The diaphragm as recited in claim 23, wherein a primer layer is arranged on the second passivation layer as a third layer configured to protect the metal material against corrosion.

25. The diaphragm as recited in claim 24, wherein the primer layer is epoxy-based or polyurethane-based.

26. The diaphragm as recited in claim 23, wherein the diaphragm body has an outer surface and an inner surface, and the first and the second passivation layers are arranged on the external surface region of the outer surface and of the inner surface of the diaphragm body.

27. The diaphragm as recited in claim 23, wherein the second passivation layer is configured as a zirconium silane compound or an organometallic compound.

28. The diaphragm as recited in claim 23, wherein, when combined, the first and the second passivation layers have a layer thickness in a range from 30 nm to 100 nm.

29. The diaphragm as recited in claim 24, wherein the primer layer has a layer thickness in a range from 30 μm to 40 μm.

30. The diaphragm as recited in claim 24, wherein a wet coating layer is arranged on the primer layer as a fourth layer.

31. The diaphragm as recited in claim 23, wherein the diaphragm body is formed as a diaphragm pot of the ultrasonic sensor, the diaphragm pot having an oscillatory diaphragm surface.

32. An ultrasonic sensor, comprising: a diaphragm including a diaphragm body made of metal material, and a second passivation layer arranged on an external, pickled surface region of the diaphragm body as a second layer, wherein to pre-activate the second passivation layer, a first passivation layer is arranged on the external, pickled surface region as a first layer.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0019] FIG. 1 shows a first specific example embodiment of a method for producing a diaphragm for an ultrasonic sensor as a vehicle component.

[0020] FIG. 2A shows a first specific example embodiment of a diaphragm for an ultrasonic transducer, comprising a diaphragm body made of metal material.

[0021] FIG. 2B shows a second specific example embodiment of a diaphragm for an ultrasonic transducer, comprising a diaphragm body made of metal material.

[0022] FIG. 2C shows a third specific example embodiment of a diaphragm for an ultrasonic transducer, comprising a diaphragm body made of metal material.

[0023] FIG. 2D shows a fourth specific example embodiment of a diaphragm for an ultrasonic transducer, comprising a diaphragm body made of metal material.

[0024] FIG. 3 shows a specific example embodiment of a diaphragm pot of an ultrasonic sensor comprising a diaphragm.

DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS

[0025] FIG. 1 shows a specific embodiment of a method for producing, in particular for coating, a vehicle component, in the form of a flowchart, in accordance with the present invention. To illustrate this better, the production of a diaphragm for an ultrasonic sensor is shown. In this context, in a first method step 10, a diaphragm body made of metal material, for example aluminum, is provided. In a subsequent method step 20, an external surface region of the metal diaphragm body is degreased. In this regard, the degreasing is carried out via treatment using alkaline dip degreasing, for example. Alternatively, the degreasing can also be carried out by acidic degreasing or spray degreasing. Once the surface has been degreased, the diaphragm body is rinsed to wash off the adherent bath solution. In a subsequent method step 30, the external surface region of the diaphragm body is pickled, so part of the external surface region of the diaphragm body is stripped away. When pickling the degreased surface region, in particular a chromium-free pickle liquor is used, for example based on hydrogen fluoride and/or dihydrogen sulfate and/or trihydrogen phosphate. The pickling process is carried out in particular in a dipping process or in a spraying process. In addition, the degreased surface region is deoxidized during the pickling. During deoxidation, the pickle liquor is adjusted such that the degreased surface region, which is alkaline after the degreasing process, is neutralized in the pickle liquor. In a subsequent method step 40, a first passivation layer is deposited on the external surface region as a first layer. In the process, the first passivation layer is deposited in particular using hexafluorotitanic acid. Next, the diaphragm body is rinsed again. The first passivation layer is for pre-activating the formation of a second passivation layer, which is applied to the first passivation layer in the subsequent method step 50. This produces a passivation layer composed of the first and the second passivation layer. Next, the diaphragm body is rinsed again and then dried. The method is then complete.

[0026] Optionally, method step 30 and method step 40 are carried out at the same time, in particular in a joint dipping bath in a pickling-passivation step.

[0027] In an optional method step 60 following method step 50, a primer layer is furthermore applied to the second passivation layer as a third layer for protecting the metal material of the diaphragm body against corrosion. In another optional method step 70, an in particular polyurethane-based wet coating is applied to the primer layer as a fourth layer. The wet coating is in particular a one-coat finishing coat as a final surface. Alternatively, the wet coating can also be a base coat having a clear-coat system applied thereto.

[0028] FIG. 2A schematically shows a diaphragm 101a for an ultrasonic transducer, comprising a diaphragm body 100 made of metal material. The diaphragm body 100 is configured as an oscillatory diaphragm surface made of metal material, in particular of aluminum. This figure schematically shows ultrasonic signals 150a emitted by the diaphragm body 100 and ultrasonic signals 150b received by it. A first passivation layer 105 is arranged on an external, pickled surface region 106 of the diaphragm body 100. This first passivation layer 105 is for pre-activating crystal formation of a second passivation layer 110 arranged directly on the first passivation layer 105. This results in a passivation layer 107 composed of the first passivation layer 105 and the second passivation layer 110. In this case, the second passivation layer 110 is configured as a zirconium silane compound. Alternatively, the second passivation layer 110 can also be configured as an organometallic compound. In this embodiment example, the passivation layer 107 composed of the first 105 and the second 110 passivation layer has a layer thickness 111 of substantially 40 nm.

[0029] In this first embodiment example of a diaphragm 101a for an ultrasonic transducer, comprising a diaphragm body 100, a primer layer 120 is arranged on the second passivation layer 110 as a third layer for protecting the metal material of the diaphragm body 100 against corrosion. In this case, this primer layer is epoxy-based. Alternatively, the primer layer can also be polyurethane-based. In this embodiment example, the primer layer 120 has a layer thickness 112 in a range from 30 μm to 40 μm.

[0030] Furthermore, in this first embodiment example, a wet coating layer 135 composed of a base-coat layer 130 and a clear-coat layer 140 is applied to the primer layer 120. In this case, the base-coat layer 130 has a layer thickness 113 in a range from 10 to 25 μm. In this case, the clear-coat layer 140 has a layer thickness 114 in a range from 25 to 35 μm.

[0031] FIG. 2B schematically shows a second embodiment example of a diaphragm 101b for an ultrasonic transducer, comprising a diaphragm body 100 made of metal material. In this case, the same layers as in the first embodiment example are arranged on an outer surface 109a of the diaphragm body 100. By contrast with the first embodiment example, in this case a further first passivation layer 151 is arranged on an inner surface 109b of the diaphragm body 100. In addition, a further second passivation layer 152 is applied to the further first passivation layer 151, such that a piezoceramic 125 adheres better to the further passivation layer 108 composed of the first 151 and the second 152 passivation layer.

[0032] FIG. 2C shows a third embodiment example of a diaphragm 101c for an ultrasonic transducer, comprising a diaphragm body 100 made of metal material. By contrast with the previous embodiment examples, in this case a powder coating layer 160 is arranged directly on the second passivation layer 110.

[0033] FIG. 2D shows a fourth embodiment example of a diaphragm 101d for an ultrasonic transducer, comprising a diaphragm body 100 made of metal material. By contrast with the previous embodiment examples, in this case a two-component water-based coating layer 170 is arranged directly on the second passivation layer 110.

[0034] FIG. 3 shows a diaphragm pot 201 as a diaphragm body of a diaphragm 200 of an ultrasonic sensor. In this case, the bottom 204 of the diaphragm pot 201 has an oscillatory diaphragm surface. When in the installed state on an external panel part of a vehicle, this oscillatory diaphragm surface is arranged in an unobstructed manner on the outside of the vehicle.

[0035] The diaphragm pot 201 is made of a metal material, in particular aluminum. In this case, an external, pickled surface region 203 of an outer surface 202 of the diaphragm pot 201 is directly coated with a first passivation layer 210 as a first layer. This first passivation layer 210 is for pre-activating a second passivation layer 215, which is again deposited directly on the first passivation layer 210 as a second layer. A primer layer 220 is again deposited directly on the second passivation layer 215 as a third layer for protecting the metal material of the diaphragm pot 201 against corrosion.