JPH0624973Y2 - Normal mode coil - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a normal mode coil for a noise filter.

[Prior Art] A conventional normal mode coil has a structure in which a winding is wound through a central hole of a toroidal core whose surface is insulated.

[Problems to be solved by the invention]

The conventional normal mode coil that uses a toroidal core has the problem that winding work is difficult and it is difficult to make it at low cost, and it is extremely difficult to handle the coil as it is with automated equipment such as automatic insertion material. There is a problem that is.

[Means for solving problems]

The present invention uses a ferrite core having a plurality of through holes formed at a predetermined pitch, and a lead frame composed of a strip-shaped frame portion and a comb-teeth-shaped lead terminal piece having a predetermined length. It is characterized in that the through holes are formed so as to penetrate in order.

〔Example〕

1 and 2 are an external perspective view of one embodiment according to the present invention and an explanatory view of the manufacturing process. In the figure, reference numeral 1 denotes a square plate-shaped ferrite core, and a plurality of two through holes (eight in the figure) parallel to the lateral lines are formed at a constant pitch. The lead frame 3 is formed of a band-shaped metal plate having high elasticity and good electrical conductivity by pressing, etching, or the like, and has a band-shaped frame portion 4 and a constant interval (through hole) in the length direction. (Same pitch as 2) and a large number of lead terminal pieces 5 formed in a comb tooth shape. Semicircular small projecting pieces 6 are formed on the frame portion 4 on the same side as the lead terminal pieces 5 and in the central portion between the lead terminal pieces 5. From the length of the through hole 2, the lead terminal piece 5
The size is slightly larger.

As shown in FIG. 2, the middle eight lead terminal pieces 5 of the lead frame 3 having ten lead terminal pieces 5 are attached to one small projecting piece from one of the through holes 2 (front side in the figure) of the ferrite core 1. 6 until they come into contact with the end face of the ferrite core 1, and from the other side of the through hole 2, the eight lead terminal pieces 5 of another lead frame 3 are stacked on the inserted lead terminal piece 5 and a small projecting piece. Insert 6 until the end face of the ferrite core 1 comes into contact. The tip of the lead terminal piece 5 inserted into the through hole 2 slightly protrudes from the through hole 2 and, as shown in FIG. 1 (only the front side is shown in the figure), is connected to the frame portion 4 of the opposite lead frame 3. It will overlap. The projecting portion of the lead terminal piece 5 and the frame portion 4 are all joined by spot welding or the like, and combined so that the lead frame 3 does not come off from the ferrite core 1.

Next, the portions indicated by broken lines in FIG. 2 are cut with a cutter, a laser, or the like so that the conductors of the two lead frames 3 pass through the through holes 2 in a zigzag order, and the lead terminal piece 5
A and the frame portion 4a portion (shown in black in the drawing) are cut off. The portion of the frame portion 4 excluding the lead terminal pieces 5a is used as an external connection terminal so that the horizontal portion is slightly lower than the bottom surface of the ferrite core 1 as shown in FIG.
Can be folded into a mold. As shown by the chain line in FIG. 1, a surface mount type normal mode coil is completed by being covered with a resin mold.

The small projecting piece 6 of the lead frame 3 is provided to separate the frame portion 4 from the end surface of the ferrite core 1 and to facilitate the cutting work of the frame portion 4.

FIG. 3 shows another embodiment of the present invention, in which the lead terminal piece 5 has two through holes 2 of the ferrite core 1 as shown by the chain line.
This is a structure in which the lead terminals 3 formed with a double pitch are used and the pin terminals 7 are joined as external connection terminals. This is a coil when it is inserted into a power supply line with a small current capacity.

[Effect of device]

The coil according to the present invention has no winding work and all the assembling work is simple, so it can be manufactured at low cost by using automated equipment. Further, since the coil has a simple shape, it can be mounted on a wiring board by using an automatic insertion material, which is effective for making circuit components at low cost.

[Brief description of drawings]

FIG. 1 is an external view showing an embodiment of a normal mode coil according to the present invention. FIG. 2 is an exploded perspective view for explaining the assembling process of the embodiment shown in FIG. FIG. 3 is an external view and a component diagram for explaining another embodiment of the present invention. 1 ... Ferrite core. 2 ... Through hole. 3 ... Lead frame. 4 ... Frame part. 5: Lead terminal piece. 6 ... Small projection piece. 7 ... Pin terminal. 8 ... Connection terminal.

Claims (1)

[Scope of utility model registration request] 1. A ferrite core having a plurality of through holes formed at a predetermined pitch, a strip-shaped frame portion, and a plurality of lead terminal pieces of a predetermined length provided in the frame portion in the shape of comb teeth. A lead frame, the lead terminal piece of the lead frame is inserted into the through hole of the core from both sides, and the projecting end portions of the lead terminal piece are joined to the frame portion, respectively, and the lead terminal piece is combined. A normal mode coil characterized in that it is configured such that a predetermined portion of the frame portion is cut off by penetrating the through hole.