Sensor device for the examination of surfaces

Abstract

A sensor device for the examination of the surfaces of a work piece, in particular with regard to burrs, is provided. The device comprises a plurality of coils, a detector head having at least one sensor element in the form of a coil and an evaluating device for the sensor signals. The detector head is adapted to be coupled electromagnetically to a work piece and/or the work piece is adapted to be irradiated by an electromagnetic signal from the detector head.

1 . A sensor device for examination of surfaces of a work piece, comprising: 
 a plurality of coils;    a detector head having at least one sensor element in the form of a coil; and    an evaluating device for evaluating sensor signals;    wherein:    the detector head is adapted to be coupled electromagnetically to a work piece and/or the work piece is adapted to be acted upon by an electromagnetic signal from the detector head;    at least a first coil and a second coil are arranged next to one another in the detector head; and    the first coil and the second coil are arranged in a difference circuit and/or an evaluation of the difference between signals from the first coil and the second coil is effected and/or the first coil and the second coil are triggered differentially.    
   
   
       2 . A sensor device in accordance with  claim 1 , wherein the first coil and the second coil are substantially identical.  
   
   
       3 . A sensor device in accordance with  claim 1 , wherein the first coil and the second coil are at an equal distance with respect to an effective surface of the sensor.  
   
   
       4 . A sensor device in accordance with  claim 1 , wherein: 
 the first coil and the second coil comprise said at least one sensor element;    the first coil and the second coil have substantially identical directions of sight.    
   
   
       5 . A sensor device in accordance with  claim 1 , wherein: 
 the first coil and the second coil comprise said at least one sensor element;    the first coil and the second coil have neighbouring fields of view.    
   
   
       6 . A sensor device in accordance with  claim 1 , wherein an end of the first coil facing an effective surface of the sensor and a corresponding end of the second coil lie in a substantially identical plane.  
   
   
       7 . A sensor device in accordance with  claim 1 , wherein: 
 a projection of a coil surface of the first coil onto a surface of the detector head and a projection of a corresponding sensor surface of the second coil onto the surface of the detector head, are located next to one another; and    the projections determine an effective sensor area of the detector head.    
   
   
       8 . A sensor device in accordance with  claim 7 , wherein the projections are spaced.  
   
   
       9 . A sensor device in accordance with  claim 7 , wherein the projections are located next to one another.  
   
   
       10 . A sensor device in accordance with  claim 1 , wherein an evaluation of at least one of an effective inductance and a Q-factor of the coils is effected.  
   
   
       11 . A sensor device in accordance with  claim 1 , wherein the first coil and the second coil are arranged in a bridge circuit.  
   
   
       12 . A sensor device in accordance with  claim 1 , wherein a transmission coil device and a receiving coil device are provided.  
   
   
       13 . A sensor device in accordance with  claim 12 , wherein the transmission coil device comprises the first coil and the second coil as transmitting coils.  
   
   
       14 . A sensor device in accordance with  claim 12 , wherein the first coil and the second coil are triggered or driven differentially.  
   
   
       15 . A sensor device in accordance with  claim 12 , wherein the receiving coil device comprises the first coil and the second coil as sensor elements.  
   
   
       16 . A sensor device in accordance with  claim 15 , wherein a differential evaluation of the signals from the first coil and the second coil is effected.  
   
   
       17 . A sensor device in accordance with  claim 1 , wherein a transmission coil and a receiving coil which is spaced therefrom in the axial direction are provided.  
   
   
       18 . A sensor device in accordance with  claim 17 , wherein the transmission coil and the receiving coil comprise respective active surfaces whose projection includes projected active surfaces of the first coil and the second coil.  
   
   
       19 . A sensor device in accordance with  claim 1 , wherein an amplitude and a frequency for a transmission coil are fixed.  
   
   
       20 . A sensor device in accordance with  claim 1 , wherein an evaluation in regard to an amplitude of the signal is effected in the case of a receiving coil.  
   
   
       21 . A sensor device in accordance with  claim 1 , wherein an evaluation in regard to a phase angle is effected in the case of a receiving coil.