Injector closed loop control
An electrical connector includes two lateral mounting bush. A knock sensor which delivers data representative of the operation of a fuel injector is integrally overmoulded in one of the mounting bush. The knock sensor includes a piezoelectric member arranged between a base member and a seismic member.
1. An electrical connector comprising:
a plastic moulded body defining a central main member for engaging a complementary connector, and also defining two lateral mounting bush which are each provided with a hole for engaging a fixation screw tightened in a face of a fuel injector; and
a knock sensor adapted to deliver data representative of operation of said fuel injector and integrally overmoulded in one of the lateral mounting bush, said knock sensor comprising a piezoelectric member arranged between a base member and a seismic member.
2. An electrical connector as claimed in claim 1 , wherein said piezoelectric member, said base member, and said seismic member have a washer-like shape defining a hole extending throughout the knock sensor and arranged aligned with the bush hole so that the fixation screw extends through the knock sensor.
3. An electrical connector as claimed in claim 2 , wherein the fixation screw generates a compression force in the piezoelectric member.
4. An electrical connector as claimed in claim 1 , wherein the base member is arranged against the face of the fuel injector and, the seismic member is arranged to be under the head of the fixation screw.
5. An electrical connector as claimed in claim 1 , wherein said electrical connector includes processing circuitry connected to said knock sensor and adapted to process data from said sensor.
6. An electrical connector as claimed in claim 1 , further comprising memory storage means for storing data characteristic of the fuel injector and raw or processed sensor data.
7. An electrical connector as claimed in claim 1 , further comprising connection means to supply processed or raw sensor data to an engine control or diagnostic unit.
8. A fuel injector comprising:
an elongated body extending along a main axis from a top end to an injection tip end, said elongated body housing a needle valve member axially moving, in use, under the influence of pressure differences generated by the displacement of an electrovalve opening or closing a spill orifice, the needle valve member moving between a closed position wherein a closing face of the needle valve member abuts a seat of the elongated body and a fully open position wherein said closing face is lifted away from said seat; and
an electrical connector comprising:
a plastic moulded body defining a central main member for engaging a complementary connector, and also defining two lateral mounting bush which are each provided with a hole for engaging a fixation screw tightened in a face of said fuel injector;
a knock sensor adapted to deliver data representative of operation of said fuel injector and integrally overmoulded in one of the lateral mounting bush, said knock sensor comprising a piezoelectric member arranged between a base member and a seismic member; and
terminals electrically connected to the electrovalve;
wherein the electrical connector is connected to an electronic unit and the knock sensor is configured to deliver a signal representative of a knock generated by abutment of the closing face against the seat when the needle valve member reaches the closed position.
9. A fuel injector as claimed in claim 8 , wherein the knock sensor is configured to detect another knock generated when the valve needle member hits a face of the elongated body when the needle valve member reaches the fully open position.
10. A fuel injector as claimed in claim 8 , wherein said electrical connector is arranged so that the fixation screws extend in parallel to the main axis.
11. A fuel injector as claimed claim 8 , wherein said electrical connector is arranged on a top end face of the elongated body, the central main member of the electrical connector being aligned to the main axis.
12. A fuel injector as claimed in claim 8 , wherein said fuel injector is a diesel injector.
13. A method for controlling a fuel injector as set forth in claim 8 , said method comprising:
computing a command signal sent to the electrovalve as a function of the signal received from the knock sensor.
14. A fuel injector as claimed in claim 8 , wherein said piezoelectric member, said base member, and said seismic member have a washer-like shape defining a hole extending throughout the knock sensor and arranged aligned with the bush hole so that one of the fixation screws extends through the knock sensor.
15. A fuel injector as claimed in claim 14 , wherein the fixation screw which extends through the knock sensor generates a compression force in the piezoelectric member.
16. An electrical connector as claimed in claim 1 , wherein the fixation screw generates a compression force in the piezoelectric member.
17. A fuel injector as claimed in claim 8 , wherein the fixation screw generates a compression force in the piezoelectric member.