Diaphragm and process for producing a diaphragm for an ultrasonic transducer

#The invention relates to a diaphragm and to a process for producing a diaphragm for an ultrasonic transducer of the type mentioned in the preamble of claims 1 and 12, respectively.

#Such a diaphragm for an ultrasonic transducer is already known from WO2005/024451 A2. The diaphragm comprises a pot-shaped diaphragm body which is made of aluminium and the base of which forms an oscillating diaphragm surface. The ultrasonic sensor is intended for use in parking assist systems of vehicles and, in the installed state, is fastened to an outer cladding part of the vehicle, with the diaphragm protruding out of the transducer housing, passing through an assembly opening in the cladding part and being arranged with the outer side of the diaphragm surface freely on the outer side of the vehicle.

#The outer side of the diaphragm surface thus forms part of the visible outer skin of the vehicle. So that the exposed diaphragm surface blends into the outer skin of the vehicle as aesthetically as possible, the outer side of the diaphragm surface is provided with a coating. In this respect, a dark-coloured powder coating is provided as the coating at least on the exposed diaphragm surface, it being possible for the powder coating to be painted over on the outside in the colour of the vehicle.

#In the illustration:

#FIG. 1 shows a section through a diaphragm for an ultrasonic transducer.

#FIG. 1 shows a section through a diaphragm 1 for an ultrasonic transducer for vehicles. The ultrasonic transducer, which is not shown in more detail, is intended for use as a distance sensor in parking assist systems of motor vehicles and comprises a transducer housing which, in the installed state, is fastened via an associated holder to an outer cladding part, such as for example a bumper, of the automobile. The outer cladding part is formed, in particular, by a trim strip which is integrated in a bumper and has a chrome-plated surface or a surface in chrome optics.

#The diaphragm 1 comprises a diaphragm body 2 which overall has a pot-shaped form and has a cylindrical circumferential wall 3 and a base region, which forms an oscillating diaphragm surface 4. The diaphragm surface 4 and the circumferential wall 3 merge into one another at their outer sides 5 and 6 at a transition region 7, the transition region 7 being formed by a radius. Alternatively, however, a transition region 7 with a bevel angle, for example, would also be possible.

#The oscillating diaphragm surface 4 is excited to oscillate via a piezo element (not shown) which is arranged, in the installed state, on the inner side of the diaphragm surface 4. A collar 9 is angled circumferentially away from the free end of the cylindrical circumferential wall 3 of the diaphragm body 2. The diaphragm body 2 has been produced from aluminium in one part and has been produced mechanically, in particular by material-removing machining, from a semi-finished product.