DE4241436A1 - Resettable sensor for triggering occupant restraint in motor vehicle - functions by penetration of needles through oppositely polarised conductive layers when side door is impacted - Google Patents

Abstract

The sensor (5) fills the space between a deformation-resistant abutment (4) and the panel (3) of a side door. It consists of alternate very thin conductive layers (12-14) with different electric polarisation (35,36), and intermediate elastic penetrable fabric (15). A row of needles (17) extends from the abutment side into a pad of penetrable insulating foam (20) between the innermost conductive layer (12) and a readily deformable thin package film (16). The foam exerts sufficient restoring force for holes made by the needles to be self-healed. ADVANTAGE - A simple device can be mfd. at favourable cost, and reverts to its initial condition after activation.

Description

The invention relates to a sensor for security Direction in vehicles according to the preamble of claim 1.

A triggering device for a safety system in motor vehicles is from EP-A2 0 305 655 based on capacity changes knows. Electrodes are attached to the inside of the door or body ordered to the buckling speed of those affected by the impact Detect parts. The detection signals serve as trigger signals for security systems such as airbags or belt tensioners. A micropro zessor evaluates the capacity changes with regard to the buckling speed, volume, location and change sequence in time or Order. The entire collision process is thus reproduced bar. However, the wiring is very extensive. The field strength Adjustment is particularly important for repairs in the body area Question asked so that a new adjustment must be made.

A collision sensor to activate a restraint for Occupants in vehicles in the event of an accidental vehicle deceleration known from DE-OS 22 12 190. For this purpose, contact strips are all around the vehicle and arranged outside. In a plastic casing three contact elements with projections are made of elastic material embedded. If the contact strip is deformed, this first contacts outer with the middle contact element. With more deformation the inner contact element is also activated. The latter contact leads to the release of the restraint system. With such a col lision sensor is the relative speed of opponents, however, the geometry of the opponent cannot be determined. The geome The counterparty provides one of the most important statements about the Risk of collision.  

The object of the invention is to propose a sensor according to returns to its starting position after becoming active. Its on construction should be simple and inexpensive.

The task is according to the characteristic feature of the Anspru ches 1 solved. Further refinements and developments of the Erfin dung emerge from the subclaims.

The more detailed explanations are given in the following description Nes embodiment and in the single figure of the drawing given. The drawing shows a cross section through a sensor.

Part of a side door 1 of a motor vehicle, not shown, consists of an outer side 3 , a deformation-resistant abutment 4 , which is stably supported on the side door 1 in a manner not shown, and a sensor 5 . The sensor 5 fills the intermediate space between the abutment 4 and the outside 3 .

The sensor 5 consists of alternating, electrically thin, very thin conductor layers 12 to 14 and interposed elastic, penetrable tissue 15 . Furthermore, an elastic, penetrable insulating foam 20 with a corresponding restoring force for the needles 17 is provided between an easily deformable, thin packaging film 16 and the conductor layer 12 .

With a deformation of the outside 3 , the sensor 5 is moved against the Wi derlager 4 . In this case, the conductor layers 12 to 14 vapor-deposited on the fabric with the fabric 15 thorn onto the needles 17 .

If the outside 3 returns to its drawn starting position, for example by bulging or in the event of an elastic deformation, the sensor 5 also takes up the drawn position again.

After the fabric 15 is woven from a special warp and weft, the holes created by the needles 17 in the conductor layers 12 to 14 and in the fabric 15 close completely. The sensor 5 is thus ready for use again.

The resetting of the sensor 5 into the drawn starting position, he follows through the elastic insulating foam 20 , which has a corresponding restoring force.

When the sensor 5 is thorned out, the needles 17 close the conductor layers 12 to 14 successively electrically short, as a result of which there is a corresponding signal for triggering safety devices in a vehicle.

The conductor layer can consist of a very thin film, of metal dust or, as already described, of a vapor-deposited metal film on the fabric 15 .

Claims (4)

1. Sensor for a safety device in vehicles with detectors arranged in the doors and the body for triggering occupant protection devices, characterized in that
that a plurality of electrical contact layers ( 12 to 14 ) with insulating intermediate layers ( 15 ) and needles ( 17 ) for contacting the contact layers ( 12 to 14 ) are covered with an elastic protective jacket ( 16 ),
at least one contact layer ( 12 to 14 ) is connected to the intermediate layer consisting of elastic, penetrable tissue ( 15 ), the tissue ( 15 ) with the contact layer ( 12 to 14 ) closing again after the needle ( 17 ) has been withdrawn. 2. Sensor according to claim 1, characterized in that the contact layer ( 12 to 14 ) consists of a very thin film of metal dust or a vapor-deposited metal film. 3. Sensor according to claim 1, characterized in that the needles ( 17 ) by an elastic, penetrable insulating foam ( 20 ) with a restoring force for the needles ( 17 ) or for the layers ( 12 to 15 ) at a distance ( 40 ) are held by the first contact layer ( 12 ). 4. Sensor according to claim 1, characterized in that the needles ( 17 ) have a slim shape.