JP3662320B2 - Ignition transformer - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an ignition transformer provided in a high voltage generator or the like that generates a high voltage from an output terminal.
[0002]
[Prior art]
High voltage generators used as ignition sources for various combustion appliances such as oil fan heaters are constructed by inserting an iron core with a primary coil through the center hole of a coil bobbin with a secondary coil. It is known that the ignition transformer is mounted on a printed circuit board on which a charge / discharge capacitor or the like is assembled and is housed in a case together with an insulating resin.
[0003]
The general shape of an ignition transformer applied to such a configuration is such that an iron core with a primary coil is inserted into a central hole of a coil bobbin made of an insulating material with a secondary coil wound around the outer periphery. The coil bobbin is connected to a terminal pin planted on the side wall.
[0004]
[Problems to be solved by the invention]
By the way, in such a configuration, as shown in FIG. 7, the conventional ignition transformer t is sealed in an insulating mold material m such as urethane resin in the case. In addition, the insulating mold material repeatedly expands and contracts due to a thermal shock due to a temperature difference in the surrounding environment, and a gap s is likely to be formed along the bobbin surface f of the bobbin n. Since the voltage difference between c is a high voltage of about 15 to 19 KV, leakage between the terminal pin p and the secondary coil c is likely to occur due to the surface discharge propagating on the surface of the bobbin surface f.
[0005]
As one means corresponding to this, the height H of the fixed seat portion r formed on the side wall may be set to 10 mm or more, and the extended distance between the secondary coil c and the terminal pin p may be increased. However, there is a problem that the bobbin n is enlarged, the height of the entire high voltage device is increased, and the size is reduced.
An object of the present invention is to provide an ignition transformer having a configuration capable of preventing leakage between a terminal pin and a secondary coil as much as possible while maintaining a thin shape.
[0006]
[Means for Solving the Problems]
According to the present invention, an iron core with a primary coil wound is inserted into a center hole of a coil bobbin made of an insulating material with a secondary coil wound around the outer periphery, and the primary coil is inserted into a terminal pin implanted on the side wall of the coil bobbin. In the connected ignition transformer, the terminal pin is implanted in a fixed seat portion formed on the side wall, and the shortest path on the bobbin surface between the terminal pin and the secondary coil is formed on the fixed seat portion inside the terminal pin. It is characterized in that a transverse groove is formed.
[0007]
In the above-described configuration, since the creeping groove that crosses the shortest path between the terminal pin and the bobbin surface of the secondary coil is formed in the fixed seat, the creeping insulation distance between the terminal pin and the secondary coil becomes long. When the coil is mounted in the case and the sealing resin is molded in the case, the sealing resin is also filled in the creeping grooves. Thus, since the creeping insulation distance between the terminal pin and the secondary coil is extended by the creeping groove, even if a gap occurs later between the bobbin surface and the sealing resin, the terminal pin and the secondary coil Leakage is less likely to occur.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment in which the present invention is applied to a high voltage generator for discharge used in a petroleum fan heater or the like will be described with reference to the accompanying drawings.
[0009]
In FIG. 3, reference numeral 1 denotes a case having a substantially rectangular shape with an open bottom surface, and an insertion groove hole 2 that opens upward is formed at one side edge of the case, and a high-pressure cord (not shown) is formed in the insertion groove hole 2. ) Are fitted with needle-like secondary output terminals 3 respectively. A primary input / output terminal 5 projects from the upper surface of the other side edge of the case 1.
[0010]
In the case 1, the circuit unit 10 shown in FIGS. In this circuit unit 10, an ignition transformer 20 is mounted on one surface side of the printed circuit board 11 via terminal pins 12, 12, and 12 e that also serve as conduction terminals, and is interposed between the printed circuit board 11 and the ignition transformer 20. In the generated gap S (see FIG. 3), a circuit portion 13 made of chip parts such as resistors and diodes is disposed. Further, the charge / discharge capacitor 14 is mounted on the other surface side, whereby the respective members are arranged in a laminated manner on the front and back of the printed circuit board 11 to constitute the circuit unit 10.
[0011]
The ignition transformer 20 includes a center hole 22 formed through a center of a coil bobbin 21 made of a synthetic resin material, and an iron core 24 around which a primary coil 23 is wound. The divided circumferential groove formed around the coil bobbin 21 25, the secondary coil 26 is continuously wound between the divided circumferential grooves 25.
[0012]
The lead-out ends 23 and 23 on both sides of the primary coil 23 are connected to the terminal pins 12 and 12 that also serve as the conduction terminals, and are provided on the charge / discharge capacitor 14 and the printed board 11 via the terminal pins 12 and 12. It is electrically connected to a circuit unit 13 (see FIG. 3) made of chip parts or the like. This circuit unit 13 is connected to the primary side input / output terminal 5 and connected to an AC power source. Also, one lead end 26a of the secondary coil 26 is connected to the secondary output terminal 3 via the connection terminal 27, and the other lead end 26b is connected to the earth via the terminal pin 12e and the required electric circuit. Is done.
[0013]
Next, the main part of the present invention will be described with reference to FIGS.
In the ignition transformer 20, the terminal pins 12, 12 electrically connected to the primary coil 23 are implanted in a fixed seat 31 that bulges outward from the side wall 30 of the coil bobbin 21. In the fixed seat 31, a creeping groove 32 is formed in the transverse direction along the side wall 30 inside the terminal pin 12. For this reason, since the creeping groove 32 is formed on the surface of the side wall 30 in the direction of blocking the shortest path between the terminal pin 12 and the secondary coil 26, the creeping insulation distance between the two becomes long.
[0014]
Then, the circuit unit 10 is housed in the case 1 and the printed circuit board 11 is housed in a positional relationship orthogonal to the installation surface L (see FIG. 3) for the combustion appliance, and an insulating molding material 35 such as urethane resin is stored. And a lid 36 is attached to the opening of the case 1 to constitute a high voltage generator. Then, as shown in FIG. 4, the insulating mold material 35 is also filled in the creeping groove 32.
[0015]
In such a configuration, the insulating molding material 35 repeatedly expands and contracts due to the heat generated in the ignition transformer 20, and as shown in FIG. 4, there may be a gap s along the side wall of the coil bobbin. Moreover, the voltage difference between the terminal pin 12 connected to the primary coil 23 and the secondary coil 26 is about 15 to 19 KV. However, as described above, the creeping groove 32 increases the creeping insulation distance between the terminal pin 12 and the secondary coil 26. Therefore, creeping discharge that occurs along the side wall surface due to the voltage difference between the terminal pin 12 and the secondary coil 26 is prevented as much as possible. For this reason, leakage hardly occurs between the terminal pin 12 connected to the primary coil 23 and the secondary coil 26.
[0016]
In the above configuration, only one creeping groove 32 is formed in the transverse direction inside the terminal pin 12 on the upper surface of the fixed seat 31. However, the creeping groove 32 may be formed in the transverse direction of the fixed seat 31. Therefore, it can be formed on the inner surface of the fixed seat 31 as shown in FIG. Further, as shown in FIG. 6, a number of creeping grooves 32 may be formed on the upper surface and / or the inner side surface of the fixed seat portion 31. Furthermore, the creeping groove 32 may be inclined as long as it crosses the shortest distance between the terminal pin 12 and the secondary coil 26.
[0017]
【The invention's effect】
As described above, the present invention provides the shortest path of the bobbin surface between the terminal pin and the secondary coil inside the terminal pin on the fixed seat portion where the terminal pin connected to the primary coil of the coil bobbin of the ignition transformer is implanted. The creepage groove that crosses the terminal pin and the creepage insulation distance between the terminal pin and the secondary coil are increased, so that even if a gap is generated between the side wall surface of the coil bobbin and the sealing resin, the leakage between the terminal pin and the secondary coil There is an excellent effect such that it is difficult to occur.
[Brief description of the drawings]
FIG. 1 is a side view of a circuit unit 10 including an ignition transformer 20 of the present invention.
FIG. 2 is an exploded perspective view of the ignition transformer 20;
FIG. 3 is a longitudinal side view of a high voltage generator.
FIG. 4 is a longitudinal side view showing the operation of the creeping groove 32;
FIG. 5 is a longitudinal side view of a main part showing a creeping groove 32 of a second embodiment.
FIG. 6 is a longitudinal side view of a main part showing a creeping groove 32 of a third embodiment.
FIG. 7 is a longitudinal side view showing a problem of a conventional configuration.
[Explanation of symbols]
1 Case 12 Terminal Pin 20 Ignition Transformer 21 Coil Bobbin 23 Primary Coil 26 Secondary Coil 30 Side Wall 31 Adhering Seat 32 Creeping Groove 35 Insulating Mold Material

Claims (1)

An ignition transformer in which an iron core wound with a primary coil is inserted into a central hole of a coil bobbin made of an insulating material wound around an outer periphery of a secondary coil, and the primary coil is connected to a terminal pin implanted on a side wall of the coil bobbin. In
The terminal pin is planted in a fixed seat portion formed on a side wall, and a creeping groove is formed in the fixed seat portion across the shortest path of the bobbin surface between the terminal pin and the secondary coil inside the terminal pin. An ignition transformer characterized by that.

Images