Sensor system for a vacuum brake booster

Abstract

The invention relates to a sensor arrangement ( 10 ) for a vacuum brake booster with a brake booster housing comprising at least one vacuum chamber ( 54 ) and one working chamber ( 26 ), which is separated from the latter by a moveable wall ( 20 ) and is connectable either to vacuum or at least atmospheric pressure, as well as a bore ( 18 ) disposed in the brake booster housing. The sensor arrangement ( 10 ) comprises a first partition ( 38 ), which seals the brake booster housing off from the ambient atmosphere when the sensor arrangement ( 10 ) is assembled. The sensor arrangement ( 10 ) also comprises a housing ( 12 ) with a first housing portion ( 13 ) which projects into the brake booster housing. The first housing portion ( 13 ) is divided by a second partition ( 40 ) into a first chamber ( 44 ) and a second chamber ( 46 ). When the sensor arrangement ( 10 ) is assembled the first housing portion ( 13 ) extends into the brake booster housing to an extent such that the first chamber ( 44 ) is directly connected to the vacuum chamber ( 54 ) of the brake booster via a first pressure inlet opening ( 52 ) and the second chamber ( 46 ) is directly connected to the working chamber ( 26 ) of the brake booster via a second pressure inlet opening ( 56 ). At least one pressure sensor ( 48, 50, 70 ) is disposed in the first housing portion ( 13 ).

1 . Sensor arrangement ( 10 ) for a vacuum brake booster comprising a brake booster housing with at least one vacuum chamber ( 54 ) and one working chamber ( 26 ), which is separated from the latter by a moveable wall ( 20 ) and is connectable either to vacuum or at least atmospheric pressure, as well as a bore ( 18 ) disposed in the brake booster housing, wherein the sensor arrangement ( 10 ) comprises: 
 a first partition ( 38 ), which seals the brake booster housing off from the ambient atmosphere when the sensor arrangement ( 10 ) is assembled,    a housing ( 12 ) with a first housing portion ( 13 ) which projects into the brake booster housing and is divided by a second partition ( 40 ) into a first chamber ( 44 ) and a second chamber ( 46 ), wherein, when the sensor arrangement ( 10 ) is assembled, the first housing portion ( 13 ) extends into the brake booster housing to an extent such that the first chamber ( 44 ) is directly connected to the vacuum chamber ( 54 ) of the brake booster via a first pressure inlet opening ( 52 ) and the second chamber ( 46 ) is directly connected to the working chamber ( 26 ) of the brake booster via a second pressure inlet opening ( 56 ), and    at least one pressure sensor ( 48 ,  50 ,  70 ) disposed in the first housing portion ( 13 ).    
     
     
         2 . Sensor arrangement according to  claim 1 , 
 characterized in that a pressure sensor ( 48 ,  50 ) is disposed in each of the two chambers ( 44 ,  46 ) of the first housing portion ( 13 ).    
     
     
         3 . Sensor arrangement according to  claim 2 , 
 characterized in that the pressure sensors ( 48 ,  50 ) are absolute pressure sensors.    
     
     
         4 . Sensor arrangement according to one of the preceding Claims, 
 characterized in that the first partition ( 38 ) and the second partition ( 40 ) constitute part of a one-piece housing insert ( 36 ) which is disposed in the first housing portion ( 13 ).    
     
     
         5 . Sensor arrangement according to one of the preceding Claims, 
 characterized in that the first housing portion ( 13 ) is of a hollow cylindrical form.    
     
     
         6 . Sensor arrangement according to  claim 5 , 
 characterized in that the first partition ( 38 ) and the second partition ( 40 ) are of a diameter which is smaller than the inside diameter of the first housing portion ( 13 ), and a sealing element ( 47   a,    47   b ), in particular an O-ring, is disposed between each partition ( 38 ,  40 ) and an inner wall ( 42 ) of the first housing portion ( 13 ).    
     
     
         7 . Sensor arrangement according to  claim 1 , 
 characterized in that a pressure sensor ( 70 ) formed as a differential pressure sensor is disposed just in one of the two chambers ( 44 ,  46 ) of the first housing portion ( 13 ) and is connected to the first chamber ( 44 ) of the first housing portion ( 13 ) via a third pressure inlet opening ( 76 ) and to the second chamber ( 46 ) of the first housing portion ( 13 ) via a fourth pressure inlet opening ( 78 ).    
     
     
         8 . Sensor arrangement according to  claim 7 , 
 characterized in that the second partition ( 40 ) is formed by an outer portion ( 74   b ) of the differential pressure sensor ( 70 ) which is sealingly connected to an inner wall ( 42 ) of the first housing portion ( 13 ).    
     
     
         9 . Sensor arrangement according to one of  claims 1  to  3  or  5  to  8 , 
 characterized in that the first partition ( 38 ) is sealingly connected to an inner wall ( 66 ) of a second housing portion ( 14 ) disposed outside of the brake booster housing.  
 
     
     
         10 . Sensor arrangement according to one of the preceding Claims, 
 characterized in that the, at least one, pressure sensor ( 48 ,  50 ,  70 ) is electrically connected via at least one connecting line ( 78 ) which is passed through the first partition ( 38 ) or the partitions ( 38 ,  40 ) in a sealed fashion.    
     
     
         11 . Sensor arrangement according to one of  claims 1  to  9 , 
 characterized in that at least one carrier element ( 58 ,  60 ) for the, at least one, pressure sensor ( 48 ,  50 ,  70 ) consists of electrically conductive material and is passed through the first partition ( 38 ) or the partitions ( 38 ,  40 ) in sealed fashion.  
 
     
     
         12 . Sensor arrangement according to  claim 10 , 
 characterized in that the, at least one, connecting line ( 78 ) is led to a connector ( 62 ) disposed outside of the brake booster housing.    
     
     
         13 . Sensor arrangement according to  claim 11 , 
 characterized in that the, at least one, carrier element ( 58 ,  60 ) is led to a connector ( 62 ) disposed outside of the brake booster housing.    
     
     
         14 . Sensor arrangement according to one of  claims 1  to  3 ,  5 ,  7  or  9  to  13 , 
 characterized in that the first partition ( 38 ) is part of a housing of an electronic controller, in which an electronic printed circuit board is disposed, this being connected in electrically conductive manner to the, at least one, pressure sensor ( 48 ,  50 ,  70 ).  
 
     
     
         15 . Vacuum brake booster with a brake booster housing containing at least one vacuum chamber ( 54 ) and one working chamber ( 26 ), which is separated from the latter by a moveable wall ( 20 ) and is connectable either to vacuum or at least atmospheric pressure, 
 characterized by a sensor arrangement ( 10 ) according to one of  claims 1  to  14 .