Needle position indicator for a fuel injector nozzle holder

A needle position indicator for a fuel injector nozzle holder which includes

• a needle having upper and lower ends;
• a needle seat for engaging the lower end of the needle;
• a chamber having an upper end and a lower end through which the upper end of the needle extends;
• a cylindrical spring including a central passageway and positioned within the chamber for exerting a force against the upper end of the needle to bias the needle against the needle seat;
• said needle position indicator comprising:
• (a) a permanent magnet positioned within the cavity for generating a magnetic field within the cavity;
• (b) a mounting bracket coupled in a fixed position within the central passageway of the spring and adjacent the lower end of the spring;
• and
• (c) a Hall Effect sensor coupled to the lower end of said mounting bracket for detecting changes in the strength of the magnetic field within the cavity caused by relative displacements between the needle and said Hall Effect sensor.

A needle position indicator for a fuel injector nozzle holder which includes

• a needle having upper and lower ends;
• a needle seat for engaging the lower end of the needle;
• a chamber having an upper end and a lower end through which the upper end of the needle extends;
• a generally cylindrical spring including a central passageway and positioned within the chamber for exerting a force against the upper end of the chamber and against the upper end of the needle to bias the needle against the needle seat;
• said needle position indicator comprising:
• (a) a permanent magnet positioned within the cavity and coupled to the upper end of the needle for generating a magnetic field within the cavity;
• (b) a mounting bracket having an upper end toward the upper end of the cavity, and extending downwardly in the central cavity of the spring and including a lower end opposing the permanent magnet;
• (c) a Hall Effect sensor coupled to the lower end of said mounting bracket at a point above and in alignment with the upper end of the needle and the permanent magnet;
• (d) means coupled to said Hall Effect sensor for transmitting the electrical output signal from said sensor to a point on the exterior surface of the nozzle holder;
• and
• (e) means coupled to said receptacle for converting the electrical output signal of said Hall Effect sensor into a signal representative of the needle position.

Apparatus for sensing the beginning of fuel injection in an internal combustion engine, said apparatus comprising:

• a fuel injector nozzle holder having a chamber with a needle and a spring in said chamber, said spring biasing said needle into a seat for preventing fuel flow until said spring bias is overcome to permit fuel flow;
• means including a magnet within said chamber for generating a magnetic field which changes with the movement of said needle from said seat;
• and
• means including a a bracket positioned within and extending through said spring in said chamber and a Hall Effect sensor carried by said bracket adjacent said magnet for detecting said changes in said magnetic field.