Transformer for igniter

A transformer for an igniter in which a primary coil and a secondary coil are wound around a bobbin, comprising:

• a plurality of disk-shaped partition walls disposed on the bobbin, around which the primary coil and the secondary coil are wound, so as to protrude from all circumferential surface of the bobbin in a radial direction of the bobbin and to form a plurality of coil winding grooves in layers;
• and
• a plurality of cut-out portions functioning as a coil taking-in portion and a plurality of coil delivery portions of the disk-shaped partition walls;
• wherein each of the cut-out portions functioning as the coil taking-in portion and the coil delivery portions of the disk-shaped partition walls does not reach the bottom surface of the corresponding coil winding groove of the bobbin, and each cut-out portion and the bottom surface of the corresponding coil winding groove are connected with each other by a coil escape groove becoming hollow on one side surface of the corresponding partition wall in a thickness direction of the corresponding partition wall.

A transformer for an igniter in which a primary coil and a secondary coil are wound around a bobbin, comprising:

• a plurality of disk-shaped partition walls disposed on the bobbin, around which the primary coil and the secondary coil are wound, so as to protrude from all circumferential surface of the bobbin in a radial direction of the bobbin and to form a plurality of coil winding grooves in layers;
• and
• a plurality of cut-out portions functioning as a coil taking-in portion and a plurality of coil delivery portions of the disk-shaped partition walls;
• wherein the coil taking-in portion is formed by cutting out the corresponding partition wall to take a winding start end of the secondary coil connected to a high voltage terminal in the corresponding coil winding groove, and a rib-shaped edge portion projected in an axial direction of the corresponding partition wall is disposed on either a whole circumferential edge of the coil taking-in portion or at least a part of the circumferential edge of the coil taking-in portion making contact with the secondary coil.

A transformer for an igniter in which a primary coil and a secondary coil are wound around a bobbin, comprising:

• a plurality of disk-shaped partition walls disposed on the bobbin, around which the primary coil and the secondary coil are wound, so as to protrude from all circumferential surface of the bobbin in a radial direction of the bobbin and to form a plurality of coil winding grooves in layers;
• and
• a plurality of cut-out portions functioning as a coil taking-in portion and a plurality of coil delivery portions of the disk-shaped partition walls;
• wherein whole circumferential edge portions of the cut-out portions functioning as the coil taking-in portion and the coil delivery portions of the disk-shaped partition walls or at least corner portions of circumferential edge portions of the cut-out portions making contact with the secondary coil are respectively formed in a curved shape or are respectively chamfered.

A transformer for an igniter in which a primary coil and a secondary coil are wound around a bobbin, comprising:

• a plurality of partition walls disposed on the bobbin so as to form a plurality of coil winding grooves corresponding to the secondary coil ranging from a low voltage step to a high voltage step in layers;
• and
• a plurality of resin leading grooves disposed on a plurality of side surfaces of the partition walls to input resin, thereby disposing a lamination layer on the primary and secondary coils, after the winding of the primary and secondary coils;
• wherein the resin leading grooves reach bottom surfaces of the coil winding grooves, and a line directed in an extension direction of each resin leading groove does not intersect an axial line of the bobbin.

A transformer for an igniter in which a primary coil and a secondary coil are wound around a bobbin, comprising:

• a plurality of disk-shaped partition walls disposed on the bobbin, around which the primary coil and the secondary coil are wound, so as to protrude from all circumferential surface of the bobbin in a radial direction of the bobbin and to form a plurality of coil winding grooves in layers;
• and
• a plurality of cut-out portions functioning as a coil taking-in portion and a plurality of coil delivery portions of the disk-shaped partition walls;
• wherein resin is injected into a peripheral space of the bobbin, the partition walls are disposed on the bobbin so as to form the coil winding grooves corresponding to the secondary coil ranging from a low voltage step to a high voltage step in layers, and a diameter of a most-outer circumference of a part of each partition wall is changed in a circumferential direction of the partition wall.

A transformer for an igniter in which a primary coil and a secondary coil are wound around a bobbin, comprising:

• a plurality of disk-shaped partition walls disposed on the bobbin, around which the primary coil and the secondary coil are wound, so as to protrude from all circumferential surface of the bobbin in a radial direction of the bobbin and to form a plurality of coil winding grooves in layers;
• a plurality of cut-out portions functioning as a coil taking-in portion and a plurality of coil delivery portions of the disk-shaped partition walls;
• and
• a pair of twining protrusive portions, which are protruded from either a most-outer circumferential wall of a low voltage side end portion of the bobbin or an arbitrary point near to the most-outer circumferential wall of the low voltage side end portion of the bobbin in both tangent directions to the most-outer circumferential wall of the low voltage side end portion of the bobbin respectively to twine a winding finish end of the secondary coil, which is wound in the layers of coil winding grooves, and both a winding start end and a winding finish end of the primary coil, which is wound around an outer circumferential portion of the secondary coil, around the twining protrusive portions, wherein a total length of the twining protrusive portions is set to be equal to or lower than the diameter of the most-outer circumferential wall of the low voltage side end portion.

A transformer for an igniter in which a primary coil and a secondary coil are wound around a bobbin, comprising:

• a plurality of disk-shaped partition walls disposed on the bobbin, around which the primary coil and the secondary coil are wound, so as to protrude from all circumferential surface of the bobbin in a radial direction of the bobbin and to form a plurality of coil winding grooves in layers;
• a plurality of cut-out portions functioning as a coil taking-in portion and a plurality of coil delivery portions of the disk-shaped partition walls;
• and
• a secondary coil taking-in slit which is disposed in a direction perpendicular to a bending direction of a top end of a high voltage terminal around which the secondary coil is twined, wherein the transformer is used for a vehicle head lamp control device comprising a high intensity discharge bulb disposed in a head lamp of an automobile, a ballast for supplying an alternating current power from a battery power source to the high intensity discharge bulb, an igniter for generating a high voltage pulse to start the discharge of the high intensity discharge bulb and the high voltage terminal for supplying a high voltage to the high intensity discharge bulb, and the high voltage terminal penetrates through a central area of the bobbin.