Rotation sensor device and method of manufacturing the same including a doubled up mounting bracket for electrical contact

An apparatus for measuring a rotational speed of a rotatable member, comprising:

• a toothed magnetic disk fixedly mounted on said rotatable member;
• a rotation sensor device disposed in opposition to said toothed magnetic disk mounted on said rotatable member;
• shaping circuit means connected to the output of said rotation sensor device for shaping an output signal of said rotation sensor device to thereby generate a pulse signal;
• and
• arithmetic means for determining the rotational speed of said rotatable member on the basis of said pulse signal;
• wherein said rotation sensor device comprises:
• a magneto-electric conversion element for detecting change of magnetic flux which takes place as said toothed magnetic disk rotates;
• a base made of a resin material for holding said magneto-electric conversion element;
• insert conductors embedded in said base using an insert molding process, said insert conductors being partially exposed on a surface of said base, said magneto-electric conversion element being electrically connected to said insert conductors;
• exposed mounting electrodes formed by bending said exposed portions of said insert conductors in a doubled-up structure, such that a respective mounting surface of the doubled-up structure of each of said exposed mounting electrodes lies along the surface of said base;
• at least one electronic part mounted on at least one of said exposed mounting electrodes, said at least one electronic part being electrically connected to said magneto-electric conversion element;
• and
• a connector portion having terminal electrodes formed by end portions of said insert conductors.

A method of manufacturing a rotation sensor device for detecting a rotational state of a rotatable magnetic member, comprising the steps of:

• forming an insert conductor strip having individual insert conductors interconnected by joint portions in a predetermined pattern using a press working;
• forming exposed mounting electrode portions by bending predetermined portions of said insert conductors in a doubled-up structure;
• embedding said insert conductor strip in a base made of a resin material using an insert molding process, such that a respective mounting surface of the doubled-up structure of each of said exposed mounting electrode portions is located along the surface of said base;
• cutting away unnecessary ones of said joint portions;
• forming an electric connection by connecting a magneto-electric conversion element to said insert conductors;
• mounting electronic parts on said exposed mounting electrodes of said insert conductors at predetermined locations;
• and
• accommodating said base in a casing and thermally staking an open end portion of said casing to thereby secure said base and said casing to each other.