Fuel injectors with integral fiber optic pressure sensors and associated compensation and status monitoring devices

An internal combustion engine fuel injector having a fuel chamber therein, a fiber optic fuel pressure sensor in the injector, said fiber optic fuel pressure sensor including a diaphragm, the diaphragm being positioned for direct contact with fuel in the fuel chamber.

An internal combustion engine fuel injector having a fuel chamber therein, a channel formed in the fuel-injector separate from the fuel chamber, said channel open to an engine combustion chamber upon installation of the injector and a fiber optic combustion pressure sensor in said channel.

An internal combustion engine fuel injector having a fuel chamber therein, a fiber optic fuel pressure sensor in the injector, said fiber optic fuel pressure sensor in communication with the fuel chamber, a channel formed in the injector, said channel open to an engine combustion chamber upon installation of the injector and a fiber optic combustion pressure sensor in said channel,

• temperature sensing means mounted in at least one pressure sensor,
• circuit means in opto-electronic communication with the sensor having the temperature sensing means therein, said circuit means including means to inject light into the at least one pressure sensor, means to detect light arriving from the at least one pressure sensor and provide a response thereto and means to detect and respond to temperature induced changes in the temperature sensing means,
• means to combine the responses to the light detected and temperature induced changes and in response thereto to provide an output corrected for the temperature induced changes.

An internal combustion engine fuel injector having a fuel chamber therein, a fiber optic fuel pressure sensor in the injector, said fiber optic fuel pressure sensor in communication with the fuel chamber, a channel formed in the injector, said channel open to an engine combustion chamber upon installation of the injector and a fiber optic combustion pressure sensor in said channel,

• wherein at least one pressure sensor includes two pairs of optical fibers and a diaphragm, both said pair of optical fibers having tips in optical reflective communication with the diaphragm,
• the tip of one pair of optical fibers spaced from the diaphragm at a distance different from the tip of the other pair of optical fibers.