Terminal fitment for lead wire connection and high-voltage variable resistor unit with relay terminal fitment

A high-voltage variable resistor unit comprising:

• a casing made of an insulating resin material;
• said casing being formed on one side thereof with an opening and having a variable resistance circuit board receiving chamber, a fixed resistance circuit board receiving chamber and a capacitor receiving chamber defined therein;
• a variable resistance circuit board received in said variable resistance circuit board receiving chamber while keeping a rear surface thereof facing said opening and provided on a front surface thereof with a variable resistance circuit pattern including an input electrode, a ground electrode and at least one output electrode;
• an input terminal fitment arranged on a rear surface of said variable resistance circuit board and electrically connected to said input electrode;
• a fixed resistance circuit board received in said fixed resistance circuit board receiving chamber and formed on a front surface thereof with a fixed resistance circuit pattern including first and second connection electrodes to which first and second fixed resistance circuit board lead wires are respectively connected;
• a relay terminal fitment arranged in any one of said fixed resistance circuit board receiving chamber and capacitor receiving chamber or in a boundary region between said fixed resistance circuit board receiving chamber and said capacitor receiving chamber and including a connection terminal section extending toward said opening of said casing and a lead wire connection section to which said lead wires are connected;
• a capacitor including first and second capacitor lead wires and received in said capacitor receiving chamber;
• said first fixed resistance circuit board lead wire and second fixed resistance circuit board lead wire of said fixed resistance circuit board being connected to said input terminal fitment and said lead wire connection section of said relay terminal fitment, respectively;
• said first capacitor lead wire and second capacitor lead wire of said capacitor being connected to said lead wire connection section of said relay terminal fitment and a terminal fitment fixed in said casing;
• said relay terminal fitment being made by subjecting a metal plate to machining;
• said lead wire connection section being formed with a lead wire press fit groove in which said second fixed resistance circuit board lead wire and first capacitor lead wire are press-fitted;
• said lead wire press fit groove including a lead wire insertion port open toward said opening of said casing and being arranged so as be open on both sides of said metal plate in a thickness direction thereof and extend in a direction from said lead wire insertion port toward a wall of said metal plate opposite to said opening;
• said metal plate having a pair of inner surfaces defining said lead wire press fit groove therebetween;
• said inner surfaces of said metal plate being formed thereon with a plurality of projections and recesses engaged with an outer periphery of said lead wires;
• said projections being arranged so as to form a plurality of pairs in such a manner that each pair of projections are opposite to each other;
• said projections being arranged so that a space defined between said projections opposite to each other is stepwise reduced in width as a distance of said lead wire press fit groove from said lead wire insertion hole is increased.