Structure and production process for secondary voltage detector for engine

A secondary voltage detector mounted on a high tension cord, for forming a capacitance with the high tension cord and thereby detecting a waveform of a secondary voltage supplied through the high tension cord to a spark plug of a gasoline engine, said secondary voltage detector comprising:

• an insulating tube which is mounted on the high tension cord, and which comprises a plurality of insulating members joined together;
• a detecting electrode embedded in at least one of said insulating members;
• and
• an electric shielding means enclosing said insulating tube,
• wherein said detecting electrode comprises an embedded portion embedded in a first insulating member which is one of said insulating members, and a bare end projecting from a joint surface of said first insulating member, and
• wherein a lead wire is connected to said bare end of said detecting electrode, said first insulating member is joined to a second insulating member which is another of said insulating members of said insulating tube, and said lead wire and said bare end of said detecting electrode are covered by said second insulating member.

A production process for producing a secondary voltage detector, mounted on a high tension cord, for forming a capacitance with the high tension cord, and thereby detecting a waveform of a secondary voltage supplied through the high tension cord to a spark plug of a gasoline engine, said production process comprising:

• a first step of forming a first insulating member in which a detecting electrode is embedded, leaving a first electrode portion of said detecting electrode exposed;
• a second step of connecting a lead wire to said first electrode portion of said detecting electrode after said first step;
• a third step of forming an insulating tube mounted on the high tension cord, after said second step, by joining said first insulating member on one side of the high tension cord and a second insulating member on the other side of the high tension cord together by an adhesive so as to cover said lead wire and said first electrode portion of said detecting electrode;
• and
• a fourth step of enclosing said insulating tube with an electric shielding layer after said third step.