Patent ID: 8950247
Filing Date: 2015-02-10
Classification: F02D,G01L,G01M

Abstract:
1. A pressure-measuring plug for a combustion engine comprising: a plug body comprising an external thread section for mounting the plug body into a cylinder head of the combustion engine and a body tip section facing in use the combustion chamber and comprising a passage; a ring-shaped sensing structure comprising an outer section, an inner section and an annular diaphragm, the plug body being attached to the outer section, wherein the ring-shaped sensing structure allows the inner section to move relatively to the outer section along a cylinder axis of the ring-shaped sensing structure by deformation of the diaphragm, a circular membrane comprising an outer part coupled to the outer section and an inner part coupled to the inner section, the membrane provides a sealing protecting the annular diaphragm against the harsh environment in a combustion chamber; and, a plug chamber formed by the circular membrane and the body tip section wherein the passage of the body tip section provides an open connection between the plug chamber and the combustion chamber, the pressure-measuring plug further comprising a channel structure forming the open connection between combustion chamber and the plug chamber, wherein the channel structure is configured to guide in use a gas flow from the combustion chamber to the plug chamber along a path, the path comprises a bend preventing direct line of sight between the combustion chamber and parts of the diaphragm positioned between the inner section and the outer section.