Pressure Measuring Glow Plug

Abstract

The invention relates to a glow plug for diesel engines, having a glow plug body comprising an external thread for threading into a threaded hole of a diesel engine, a heating rod that is displaceable in an axial direction of the glow plug body and protrudes from it, a pressure measuring device for measuring a combustion chamber pressure acting on the heating rod, and a sealing membrane disposed between the glow plug body and the heating rod. It is provided according to the invention that an annular or sleeve-shaped vibration damper composed of a perfluorelastomer is disposed between the glow plug body and the heating rod for damping radial oscillations of the heating rod.

1 - 14 . (canceled) 
     
     
         15 . A glow plug for diesel engines, having a glow plug body comprising:
 an external thread for threading into a threaded hole of a diesel engine;   a heating rod that is displaceable in an axial direction of the glow plug body and protrudes from it   a pressure measuring device for measuring a combustion chamber pressure acting on the heating rod; and   a sealing membrane disposed between the glow plug body and the heating rod, wherein an annular or sleeve-shaped vibration damper composed of a perfluorelastomer is disposed between the glow plug body and the heating rod for damping radial oscillations of the heating rod.   
     
     
         16 . The glow plug according to  claim 15 , wherein the vibration damper is an O-ring. 
     
     
         17 . The glow plug according to  claim 15 , wherein the perfluoroelastomer is a perfluoro rubber. 
     
     
         18 . The glow plug according to  claim 16 , wherein the vibration damper is disposed on an antinodal point of the strongest radially acting harmonic. 
     
     
         19 . The glow plug according to  claim 18 , wherein the strongest radially acting harmonic is the third or fourth natural oscillation. 
     
     
         20 . The glow plug according to  claim 15 , wherein the vibration damper is disposed behind the sealing membrane, as viewed from the combustion chamber. 
     
     
         21 . The glow plug according to  claim 15 , wherein the heating rod is enclosed by at least two vibration dampers. 
     
     
         22 . The glow plug according to  claim 21 , wherein the two vibration dampers are disposed on the two strongest antinodal points of radially acting harmonics. 
     
     
         23 . The glow plug according to  claim 15 , wherein the at least one vibration damper has a higher elastic modulus in the radial direction than in the axial direction. 
     
     
         24 . The glow plug according to  claim 15 , wherein the sealing membrane is composed of metal. 
     
     
         25 . The glow plug according to  claim 15 , wherein the sealing membrane forms a bellows or a corrugated tube. 
     
     
         26 . The glow plug according to  claim 15 , wherein the vibration damper encloses a constriction of the heating rod. 
     
     
         27 . The glow plug according to  claim 15 , wherein the heating rod comprises an inner pole and a housing tube that encloses the inner pole, the housing tube being enclosed by the vibration damper. 
     
     
         28 . The glow plug according to  claim 27 , wherein the housing tube extends to the pressure measuring device.