Triggering device for a safety device in an automotive vehicle

• US 7,845,677 B2
• Filed: 07/30/2008
• Issued: 12/07/2010
• Est. Priority Date: 07/31/2007
• Status: Active Grant

• Current Assignee: Tdk-Micronas Gmbh (TDK Corporation)
• Original Assignee: Micronas Gmbh (TDK Corporation)
• Inventors: Franke, Jörg
• Primary Examiner(s): Fleming; Faye M.
• Application Number:
  US12/182,658
• Publication Number:
  US 20090066066A1
• Time in Patent Office: 860 Days
• Field of Search: 280/735
• US Class Current: 280/735
• CPC Class Codes: B60R 2021/01006 Mounting of electrical components in vehicles
• CPC Class Codes: B60R 21/0136 responsive to actual contact with an obstacle , e.g. to vehicle deformation, bumper displacement or bumper velocity relative to the vehicle monitoring crash strength in combination with passenger seat detection B60R21/01558
• CPC Class Codes: G01D 11/245 Housings for sensors
• CPC Class Codes: G01D 11/30 Supports specially adapted for an instrument; Supports specially adapted for a set of instruments
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/49175 Parallel arrangements
• CPC Class Codes: H01L 2224/73265 Layer and wire connectors
• CPC Class Codes: H01L 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details

Abstract

A triggering device for a safety device in an automotive vehicle, in particular for an airbag, has an electrical component that has at least one force sensor and that is attached to the body of the automotive vehicle in such a way that a measurement signal that is dependent on the deformation of the body can be applied at a measurement signal output of the force sensor. An evaluation device for processing the measurement signal is connected to the measurement signal output. The force sensor has at least one piezo element, which is integrated into a CMOS chip together with the evaluation device.

Claims

1. A triggering device for a safety device in an automotive vehicle, the triggering device comprising:

an electrical component that has at least one force sensor and that is attached to the body of the automotive vehicle in such a way that a measurement signal that is dependent on the deformation of the body is applied at a measurement signal output of the force sensor; and

an evaluation device that is used to process the measurement signal and that is connected to the measurement signal output,

wherein the force sensor has at least one piezo element that, together with the evaluation device, is monolithically integrated into a CMOS chip,

wherein the evaluation device has a nonvolatile data memory in which at least one triggering characteristic value is stored, the evaluation device has a comparison device to compare the at least one triggering characteristic value with the measurement signal, and wherein the evaluation device is configured such that the triggering signal is generated depending on the result of this comparison.

2. The triggering device of claim 1, wherein the CMOS chip has a plurality of piezo elements that are connected to each other at a Wheatstone bridge circuit.

3. The triggering device of claim 1, wherein the CMOS chip has a plurality of piezo elements that are connected to the evaluation device Hand with which force measurement signals may be measured for at least two principal measurement directions that are arranged perpendicular to each other, and wherein the evaluation device is designed in such a way that the triggering signal is generated depending on the magnitude, the rate of change and/or the direction of a measurement signal resulting from the measurement signals that are produced.

4. The triggering device of claim 1, wherein it has at least two piezo elements that are arranged at an angle of about 45°

relative to reach other and at least one of these piezo elements is arranged so that its principal measurement direction is parallel to the orientation of the crystals in the CMOS chip and/or to a peripheral area and/or an edge of the CMOS chip.

5. The triggering device of claim 1, wherein the CMOS chip is connected in an essentially two-dimensional manner via an interference fit to a first surface region of the vehicle body by means of an adhesive layer that extends roughly parallel to the principal plane of extension of the chip, and the arrangement that is comprised of the CMOS chip and the at least one adhesive layer is covered with a solidified casting compound that is connected in a tightly sealing manner to a second surface region of the automotive body that laterally borders on the adhesive layer.

6. The triggering device of claim 1, wherein the CMOS chip is connected by means of the least two stacked adhesive layers to the first surface region of the automotive body, and a metal foil is located between these adhesive layers.

7. The triggering device of claim 1, wherein the CMOS chip is covered by a casting compound that surrounds it in a tightly sealing manner, and the casting compound has at least two holes that are separated laterally from each other and through which the fasteners are passed, by which means the electronic component that is comprised of the CMOS chip and the casting compound is connected to the body via an interference fit.

8. The triggering device of claim 1, wherein the CMOS chip is connected with via an interference fit to the body of the vehicle by means of a casting compound that adheres to the body, and the casting compound is located between the CMOS chip and the body and/or grasps the body from behind.

9. The triggering device of claim 1, wherein the component is covered by a plate-shaped retention part, and the retention part is clamped to the body at fastening points on both sides of the electronic component and is supported against the body between the fastening points across the electronic component.

10. The triggering device of claim 1, wherein the component is attached to a part of the outer skin of the body that forms the body wall at its back side facing away from exterior side of the vehicle.

11. The triggering device of claim 1, wherein a bus interface, which preferably is compatible with the PSI5-Standard, is integrated into the CMOS chip.

12. The triggering device of claim 1, wherein the triggering device has a diagnostic device that has means to detect a signal component that is contained in the measurement signal and that is caused by vibrations caused by an internal combustion engine powering the automotive vehicle.

13. The triggering device of claim 1, wherein at least one additional sensor that differs from the force sensor, in particular a temperature sensor, a sensor for measuring an electrical capacitance, a magnetic field sensor, and/or a moisture sensor, is integrated into the CMOS chip.

14. The triggering device of claim 1, wherein the at least one additional sensor comprises a pressure sensor and/or an acceleration sensor, and in that an output of the pressure sensor and/or the acceleration sensor is connected to an input of the evaluation devices.

15. The triggering device of claim 1, wherein a pressure sensor is integrated into the CMOS chip.

16. The triggering device of claim 1, wherein the evaluation device compares the measurement signal from the force sensor with an output signal of the pressure sensor.