Search

EP-4740302-A1 - SENSOR DEVICE AND METHOD FOR PRODUCING A VEHICLE DOOR HANDLE HAVING A SENSOR DEVICE

EP4740302A1EP 4740302 A1EP4740302 A1EP 4740302A1EP-4740302-A1

Abstract

The invention relates to a sensor device (1), for example for a motor vehicle. The sensor device comprises a printed circuit board (2) with a sensor electrode (3), a cover plate (4) with a sensing area (6), and if necessary a spacer (5, 5'). A cavity (H) is formed between the sensor electrode (3) and the cover plate (4). A control and evaluation device (7) is present to provide the functionality. The cover plate (4) is coupled to the control and evaluation device (7), which can be used to switch over the electrical potential level of the cover plate (4). The sensor electrode presented can be used to sense pressure actuation performed on the outside (A) by an operator (B). The invention also presents a method for producing a vehicle door handle.

Inventors

  • BEXTERMÖLLER, HUBERT

Assignees

  • HUF Hülsbeck & Fürst GmbH & Co. KG

Dates

Publication Date
20260513
Application Date
20240606

Claims (15)

  1. 1. Sensor device (1), preferably for a motor vehicle, comprising a circuit board (2) with a sensor electrode (3), a cover plate (4) which is both mechanically flexible and electrically conductive, for covering the circuit board (2) from an exterior of the sensor device (1), wherein the cover plate (4) provides a touch area (6) for detecting a pressure actuation, wherein the touch area is designed to reduce the distance between the cover plate (4) and the circuit board (2) when the touch area (6) is press-actuated, wherein the sensor electrode (3) is coupled to a control and evaluation device (7) for determining a variable which is dependent on the capacitance of the sensor electrode (3) with respect to the cover plate (4), wherein the cover plate (4) is coupled to the control and evaluation device (7), and the control and evaluation device (7) is designed to switch the electrical potential level of the cover plate (4).
  2. 2. Sensor device (1) according to claim 1, wherein the touch area (6) is fixed at a defined distance from the circuit board (2) by means of a spacer (5, 5') or several spacers (5, 5') such that when the touch area (6) is pressed, the distance between the cover plate (4) and the circuit board (2) is reduced. 3. Sensor device (1) according to claim 1 or claim 2, wherein the control and evaluation device (7) is arranged in a pressure actuation detection mode to set the electrical potential level of the cover plate (4) to ground potential or a predetermined reference potential. and with the potential level of the cover plate (4) switched to ground potential or a predetermined reference potential, the pressure actuation in the sensing area (6) by determining the capacitance of the sensor electrode
  3. (3) relative to the cover plate (4) to detect a variable.
  4. 4. Sensor device (1) according to one of claims 1 to 3, wherein the control and evaluation device (7) is arranged to switch the cover plate (4) as a capacitive proximity detection electrode in a proximity detection mode.
  5. 5. Sensor device (1) according to claim 4, wherein the control and evaluation device (7) is set up to switch the sensor electrode (3) arranged on the circuit board (2) to be potential-free, that is to say "floating", in a proximity detection mode.
  6. 6. Sensor device (1) according to claim 4, wherein the control and evaluation device (7) is arranged to switch the sensor electrode (3) arranged on the circuit board (2) to a ground potential in a proximity detection mode.
  7. 7. Sensor device (1) according to one of the preceding claims, wherein a second sensor electrode (8) is arranged on the circuit board (2).
  8. 8. Sensor device (1) according to claim 7, wherein the second sensor electrode (8) is further spaced from the cover plate (4) than the first sensor electrode (3).
  9. 9. Sensor device (1) according to claim 7 or according to claim 8, wherein the control and evaluation device (7) is arranged is, in a proximity detection mode, the second sensor electrode (8) to a ground potential
  10. 10. Sensor device (1) according to one of claims 4 to 9, wherein the control and evaluation device (7) is arranged to switch the wiring of the sensor electrode and the cover plate (4) between a pressure actuation detection mode and a Proximity detection mode in time division multiplexing.
  11. 11. Sensor device (1) according to one of claims 4 to 10, wherein the control and evaluation device (7) is set up to operate the cover plate (4) in the proximity detection mode during regular operation and to switch on the pressure actuation mode after the cover plate (4) connected as a proximity electrode has detected an approach, or the control and evaluation device (7) is set up to operate the cover plate (4) in the proximity detection mode during regular operation when the pressure actuation mode is switched on at a first frequency per unit of time and to switch on the pressure actuation mode at a second frequency per unit of time after the cover plate (4) connected as a proximity electrode has detected an approach, wherein the second frequency per unit of time is greater than the first frequency per unit of time.
  12. 12. Sensor device (1) according to one of claims 4 to 11, wherein the control and evaluation device (7) is arranged to only recognize a detected pressure actuation under the condition that the pressure actuation is detected as plausible to specify that within a specified maximum period of time before the detected pressure actuation, at least one proximity detection, preferably a minimum number of proximity detections stored on the control and evaluation device (7), was detected, and otherwise the detected pressure actuation is rejected as a pressure actuation that was not detected with plausibility.
  13. 13. Sensor device (1) according to one of the preceding claims, wherein the spacer (5, 5') is an incompressible film or a PCB, preferably with a thickness of less than 2 mm, particularly preferably with a thickness of less than 1 mm.
  14. 14. A method for producing a vehicle door handle (9) with a sensor device (1) according to one of the preceding claims, comprising the steps: - providing a vehicle door handle body (9') with a cavity (10); - Positioning the sensor device (1) in the cavity (10) of the vehicle door handle body with alignment of the cover plate (4) to a with an outer touch pressure area (11) of the vehicle door handle corresponding inner wall (11') and then fixing the sensor device (1); - Filling a remaining gap between the cover plate (4) and the inner wall (11') with a hardening, electrically non-conductive casting material (12) of high mechanical hardness.
  15. 15. Method according to claim 14, characterized in that the potting material (12) is an epoxy resin

Description

Sensor device and method for producing a vehicle door handle with a sensor device The invention relates to a sensor device which can be used for applications in motor vehicles, for example. In particular, applications in motor vehicle door handles can be provided. The invention also relates to a method for producing a motor vehicle door handle with a sensor device. The sensor device which is the subject of the present invention provides a capacitive detection system. Capacitive detection systems for detecting approaches are known from practice. A measuring principle for detecting an approach or an actuation of a switch is based on the determination of a capacitance or a quantity dependent on the capacitance or on the change in the capacitance or a quantity dependent on the capacitance. There are commercially available sensors on the market which have a sensor electrode to which a thin, electrically conductive - in particular metallic - pressure element is arranged, which is at ground potential when the sensor is in operation. In practice, such sensors are referred to, for example, under the keyword "metal over capacitive". An example of such a sensor is the AN1325 from Microchip (see, for example, the link accessed on the filing date https : / /wwl . microchip . com/ downloads/ en/ Appnot es/ 01325A. pdf ). In such a sensor, the basic configuration is that the pressure element and the sensor electrode form a capacitor. This capacitor can be ideally viewed as a plate capacitor, which is why its capacitance is exactly or approximately reciprocal to the change in the distance between the Sensor electrode and the pressure element. The detection of the capacitance or the change in the capacitance, possibly indirectly via the measurement of a quantity dependent on the capacitance, can therefore serve as a basis for detecting pressure on the pressure element. Such systems are referred to below as metal-covered pressure sensors. Pressure sensors with a metal cover have a number of advantages. For example, they are easy to clean and therefore well suited for use in demanding environments, such as in the medical field, in food technology, or as part of a motor vehicle with partial contact with the outside and therefore exposure to environmental influences such as precipitation. The metal cover also prevents contamination from dust, dirt or penetrating liquids, or at least limits the extent of it. The presence of a metal cover also offers good conditions for providing a sensor with a high-quality appearance. A further advantage of the metal-covered pressure sensors is that due to the sensitive dependence of the capacitance on the distance between the metal cover and the sensor, namely with a factor of 1/d, pressure actuations can be detected even with low pressure forces and consequently small deflections of the cover plate, particularly with appropriately dimensioned small distances. Compared to systems with similar sensor performance, such as piezo sensors or inductive sensors, a metal-covered pressure sensor based on capacitance detection has the additional advantage that the implementation requires a lower Complexity in component provision is required, which keeps costs comparatively low. Modern vehicles and their operating systems require increasingly complex and flexible adaptation options. The invention is therefore based on the object of providing an improved sensor device whose functionality is based on the detection of capacitances or changes in capacitances or variables dependent thereon. The object is achieved with a sensor device having the features of claim 1. The object is further achieved with a method for producing a vehicle door handle having the features of claim 14. A sensor device is proposed. The sensor device can be intended for use in a motor vehicle, for example. The sensor device has: - a circuit board with a sensor electrode, as well as - a cover plate that is both mechanically flexible and electrically conductive. The cover plate serves to cover the circuit board from the outside of the sensor device, i.e. from a side facing away from the sensor electrode. The cover plate can be, for example, a thin metallic plate, for example with a thickness of between 0.05 mm and 1 mm, so that the desired combination of mechanical flexibility and electrical conductivity is provided by a combination of material, i.e., metallic material such as stainless steel, and provision as a thin plate. The mechanical flexibility means that the cover plate can be pressed with a finger of an operator to open its Distance from the sensor electrode is reduced, and When the finger is removed, the sensor returns to its original position. The precise dimensioning of the interaction between material, thickness of the cover plate and distance of the cover plate from the sensor electrode must be selected by the specialist implementing the system depending on the specific application and the desired properties, for example w