Combustion pressure sensor and its assembly in an engine component of an internal combustion engine

[0069] In the cross section, figure 1 The combustion pressure sensor assembly installed in the surrounding engine component mounting structure 8 is schematically shown. In this example, the engine component mounting structure 8 may be a cylinder head of an internal combustion engine or a body of a fuel injector, or any other engine component, such as a spark plug or a glow plug. The combustion pressure sensor (CPS) has a sensor body 9, which can be conveniently made of materials such as quartz, ceramic materials or Kovar (Kovar, low CTE stainless steel). In the sensor body 9, the optical transmission fibers 1, 2, 3, 4 are arranged so that their ends face the deformable film 7.

[0070] The first central optical fiber 1 and the second central optical fiber 2 are positioned to detect the bending of the deformable film 7, which is mainly caused by pressure changes and only to a small extent due to temperature changes.

[0071] The first outer edge optical fiber 3 and the second outer e