Device and method for monitoring the air pressure of a vehicle tyre

摘要

A device for monitoring the air pressure in a pneumatic tyre which is borne by the rim of a vehicle wheel and has a sensing element which is arranged on the ring of the rim, can be acted on by the pressure of the tyre and deformed and has a permanent magnet as measured value sensor in whose area of rotation a measured value sensor which is fixed to the vehicle and connected to an evaluation circuit is arranged, is intended to operate reliably and be of uncomplicated design. To this end, the sensing element is constructed as a folding bellows (36) and attached in a direction of movement approximately parallel to the axis and is connected to the permanent magnet (40) which can be displaced parallel to the axis as a function of the tyre pressure at the outside of the tyre, the said permanent magnet (40) resting under normal tyre pressure (P) in a position near to the measured value sensor (50) and this distance being larger when the tyre pressure is reduced. In addition, the folding bellows (36) is intended to project into the air space (25) of the tyre from a shoulder housing of the ring (21) on the rim and to be connected to a bistable rocker via an axial rod or the like, it being possible for a permanent magnet which is attached parallel to the axis to be moved by the said rocker.