Air flow meter for an automobile

#1. Field of the Invention

#The invention relates to air flow meters and more particularly to ion drag air flow meters for automobile applications.

#2. Description of the Known Technology

#FIG. 1 is a perspective view of an air flow meter embodying the principles of the present invention;

#FIG. 2 is another perspective view of the air flow meter of FIG. 1;

#FIG. 3 is rear view of the air flow meter of FIG. 1;

#Referring to FIGS. 1, 2, and 3, an air flow meter 10 is shown. The air flow meter 10 generally includes a tube 12 having an exterior surface 14 and an interior surface 16 generally defining an interior space 18. An electrically grounded metallic layer 19 is coupled to the exterior surface 14 of the tube 12. This electrically grounded metallic layer 19 provides a more stable environment for the charged ions that are within the interior space 18 of the air flow meter 10.

#A first collector 20 and a second collector 22 are disposed within the interior space 18. The first and second collectors 20 and 22 are preferably collector bars capable of collecting ions. As the collectors 20 and 22 collect ions, the collectors 20 and 22 output a first collector signal and a second collector signal, respectively. The first and second collector signals are independent, each representative of the air flow through the air flow meter 10, and are outputted to a control system 24, which may be located adjacent to the exterior surface 14 of the air flow meter 10. A further description of the control system 24 will be described later in this detailed description section.

#As stated previously, the first and second collectors 20 and 22 are capable of collecting ions and outputting signals indicative of the amount of ions collected by each collector. The transmission pins 26A-26D each have tips 27A-27D, respectively. These ions are generated by a plurality of transmission pins 26A-26D that protrude from the interior surface 16 of the tube 12. Generally, these transmission pins 26A-26D protrude from the interior surface 16 of the tube 12 between the first collector 20 and second collector 22. The tips 27A-27D of the plurality of transmission pins 26A-26D substantially point to a center point of the interior space 18. Additionally, the tips 27A-27D of the plurality of transmission pins are 26A-26D generally equally spaced along a diameter of the tube 12.