Pencil-type glow plug having an integrated combustion chamber pressure sensor
AssigneeRobert Bosch GmbH
InventorsChristoph Kern, Steffen Schott, Markus Ledermann, Pavlo Saltikov
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Abstract
A pencil-type glow plug for a self-igniting internal combustion engine is described. The pencil-type glow plug includes a plug body in which a combustion chamber pressure sensor is integrated, and a bar-shaped heating element that protrudes out from the plug body at one end, into the combustion chamber of the internal combustion engine. A force-measuring element of the combustion chamber pressure sensor is accommodated behind the heating element, which moves axially under the influence of force. The force-measuring element is sealed against combustion chamber gases by a steel diaphragm made of a stainless precipitation-hardened maraging steel.
Claims11
A pencil-type glow plug for a self-igniting internal combustion engine, comprising:
- a plug body in which a combustion chamber pressure sensor is integrated;
- a bar-shaped heating element that protrudes out at one end from the plug body and protrudes into a combustion chamber of the internal combustion engine;
- and
- a force-measuring element of the combustion chamber pressure sensor accommodated behind the heating element, which is capable of axial movement when acted on by pressure, the force-measuring element being sealed against combustion chamber gases by a steel diaphragm made of stainless precipitation-hardened maraging steel.
A combustion chamber pressure sensor for acquiring the pressure in a combustion chamber of an internal combustion engine, the sensor including a steel diaphragm that shields a force-measuring element against combustion chamber gases, the steel diaphragm being manufactured from a steel having the following composition:
- 11.0% by weight to 15.0% by weight Cr,
- 6.0% by weight to 9.0% by weight Ni,
- 0.1% by weight to 0.3% by weight Ti,
- 0.1% by weight to 0.3% by weight Be,
- 0.5% by weight to 1.5% by weight Mo,
- remainder iron.
Dependencies are inferred from the claim text.