Device for Detecting the Combustion-Chamber Pressure in an Internal Combustion Engine

Abstract

A device for detecting the pressure in a combustion chamber of an engine is designed in such a way that the combustion-chamber pressure can be detected reliably and reproducibly. For this purpose, a glow element in a glow plug, exposed to the combustion-chamber pressure, is fixedly mounted in a housing of the glow plug via a fastening element. A sensor is fixedly mounted in the housing of the glow plug using this fastener located at a distance from the fastening element. This sensor detects the elastic deformation of the glow element caused by the combustion-chamber pressure. This device is preferably used in the automobile industry.

1 - 12 . (canceled)  
   
   
       13 . A device for detecting a cylinder pressure in an internal combustion engine, comprising: 
 a glow plug having a housing adapted to be mounted in a cylinder head of the engine, the glow plug having a first end and a second end;    a glow element situated at the first end of the glow plug, which, when the glow plug is installed, at least partially protrudes into a combustion chamber of the engine;    a fastening element attaching the glow element to the glow plug; and    a sensor situated between the fastening element and the second end of the glow plug.    
   
   
       14 . The device according to  claim 13 , wherein the engine is a diesel engine.  
   
   
       15 . The device according to  claim 13 , wherein the sensor is separated from the fastening element of the glow element and is secured in the glow plug at least indirectly via a fastener.  
   
   
       16 . The device according to  claim 15 , wherein the sensor is connected to the glow element at least indirectly by friction lock.  
   
   
       17 . The device according to  claim 16 , wherein the at least indirect friction lock between the sensor and the glow element is implemented with pre-stress.  
   
   
       18 . The device according to  claim 15 , wherein the sensor is connected to the fastener at least indirectly by friction lock.  
   
   
       19 . The device according to  claim 18 , wherein the at least indirect friction lock between the sensor and the fastener is implemented with pre-stress.  
   
   
       20 . The device according to  claim 13 , wherein the sensor is separated from the glow element by at least one spacer.  
   
   
       21 . The device according to  claim 18 , wherein the sensor is separated from the fastening element by at least one spacer element.  
   
   
       22 . The device according to  claim 20 , wherein the spacer is an intermediate sleeve.  
   
   
       23 . The device according to  claim 21 , wherein the spacer element is an intermediate sleeve.  
   
   
       24 . The device according to  claim 22 , wherein the intermediate sleeve is made of graphite.  
   
   
       25 . The device according to  claim 23 , wherein the intermediate sleeve is made of graphite.  
   
   
       26 . The device according to  claim 15 , wherein the fastener is a sleeve caulked to the housing.  
   
   
       27 . The device according to  claim 13 , wherein the sensor is a force sensor designed as a piezoelectric ring.