JPS59181005A - Beads inductor and manufacture thereof - Google Patents

Abstract

PURPOSE:To facilitate the electrical connection by holding the conductor surely by forming the present inductor out of a ferrite core having a through-hole, a conductor arranged to be inserted in said through-hole and a pair of stopper parts being in contact tightly with the ferrite core surface. CONSTITUTION:A beads inductor 10 is an approximate rectangular parallelopiped as a whole. A ferrite core comprises a through-hole 11 whose cross section is a circule. A cylindrical conductor 13 so inserted that is projects slightly from the openings of the both ends of the through hole 11. A pair of L-shaped stopper parts 18 comprise cutouts 15 cut in U-shape which connected tightly to the parts of the conductor 13 which are projecting slightly from the both end openings of the through-hole 11, and it is closely in contact with the end surfaces 16 and the side surfaces 17 of the core 12. Then the conductor is held surely and it becomes possible to electrically connect the conductor alone by placing it on the print circuit board.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a small bead inductor used, for example, in a noise filter, and a method for manufacturing the same.

As shown in FIG. 1, a conventional bead inductor 1 includes a ferrite core 2 having an approximately rectangular parallelepiped shape as a whole.
A through hole 3 is bored along the longitudinal direction of the ferrite core 2, and a conductor 4 having approximately the same length as the through hole 3 is inserted between the end surface of the conductor 4 and the end surface of the ferrite core 2 where the through hole 3 opens. An electrode layer 5 is placed on the end surface of the ferrite core 2 in which the through hole 3 opens, the peripheral side surface near the end surface, and the end surface of the conductor 4 arranged so that the electrode layers 5 and 4 coincide with each other.
5 is formed.

However, since the bead inductor 1 having the above structure requires a plating process to form the electrode layers 5, 5, it has not been possible to consistently and automatically manufacture the bead inductor 1 using an automatic manufacturing machine. Furthermore, in the bead inductor 1 having the above configuration, the conductor 4 is held in the through hole 3 by the frictional force between the inner circumferential surface of the through hole 3 and the outer circumferential surface of the conductor 4, so that the through hole 3 can be drilled with high accuracy. Therefore, the ferrite core 2 cannot be easily processed.

In addition, if a 7-elite core 2 having a through hole 3 whose cross-sectional contour is larger than that of the conductor 4 is used, the conductor 4 will be held by the electrode layers 5, There is a risk that the conductor may break through the electrode layer 10 and fall out of the through hole 4 due to the impact.

The present invention has been made in view of the above circumstances, and provides a bead inductor that securely holds a conductor, a bead inductor that does not require a plating process or strict processing accuracy, and has an inexpensive and simple configuration, and a method for manufacturing the same. The purpose is to provide the following.

Next, the present invention will be explained by showing one embodiment along with the drawings.

As shown in FIG. 2, the bead inductor 10, which is an embodiment of the first invention in this application, has a generally rectangular parallelepiped shape (r). 11, and a cylindrical conductor 13 that is slightly longer than the length of the through hole 11 and is inserted into the through hole 11 so as to slightly protrude from both end openings of the through hole 11. , the conductor 13
The U-shape (in FIG. 2, for convenience of explanation, it is shown as a U-shape that is tightly engaged with a portion that slightly protrudes from both ends of the through hole 110 (hereinafter also referred to as the protrusion 14)). The ferrite core 12 has a notch 15 cut out at the end surface 16 of the ferrite core 12.
(the surface having the opening of the through hole 11) and a pair of L-shaped locking portions, such as locking plates 18, 18, which are in close contact with the longitudinal side surface 17 of the ferrite core 12.

As shown in FIG. 3, the through hole 11 has a diameter D1
is larger than the diameter D2 of the conductor 13.

Therefore, the diameter D1 of the through hole 11 is equal to that of the conductor 1.
The holes can be drilled without requiring strict machining accuracy to make the diameter D2 equal to the diameter D2 of No. 3. If strict processing accuracy is not an issue, the through hole 11 is
The diameter D1 may be formed to be equal to the diameter D2 of the conductor 13. The length 12 of the conductor 13 is larger than the length 11 of the ferrite core 12 in the longitudinal direction.

The conductor 13 is formed in this way by the ferrite core 1
The protruding portions 14 of the conductor 13 protruding from both end surfaces of the conductor 13 are fitted into the cutout portions 15 of the locking plate 18, whereby the conductor 130
This is to ensure positioning and retention within the through hole ll. Therefore, it is preferable that the notch 15 of the locking plate 18 is cut out in a U-shape into which the conductor 13 can be tightly fitted. Further, the locking plate 18 is connected to the end surface 1 of the ferrite core 12.
It is preferable that the shape and size of the locking plate 18 be adjusted so that the locking plate 18 is in close contact with the side surface 17 and a sufficient frictional force is exerted.It goes without saying that the locking plate 18 is made of metal. The conductor 13 can be held in the through hole 11 without wobbling by the locking plates 18, 18.In order to securely hold the conductor 13, a notch for locking the conductor 13 is provided. 15 may be subjected to appropriate means such as soldering or welding.

The bead inductor 10 configured as described above can be manufactured without requiring strict processing accuracy, and since the locking plate 18 acts as an electrode, the bead inductor 10 can be mounted on a printed wiring board. It can be easily integrated into the circuit.

Next, a method for manufacturing a bead inductor, which is the second invention of the application filed by , will be explained.

First, as shown in FIG. 3, a conductor 13 having a length Ij2 larger than the length lI of the through hole 11 is inserted into the through hole 11 of a ferrite core 12 having a through hole 11 having a diameter D1. As shown in FIG. 4, the conductor 13 is positioned so that both ends of the conductor 13 form protrusions 14 and 14.

In this case, the ferrite core 12 can be easily formed because it is not necessary to make the diameter Dl of the through hole 11 exactly match the diameter D2 of the conductor 13. Further, after using a conductor 13 having an appropriate length larger than the length of the through hole 11 and arranging the conductor 13 so that both ends of the conductor 130 protrude from the opening of the through hole 11, the length of the conductor 13 is 12 The protrusion 14 may be formed by cutting both ends of the conductor 130 so that

Next, as shown in FIG. 5, a frame body (hereinafter referred to as ,
Also called lead frame. )21 is formed. After this,
As shown in FIG. 4, the end surface contact portion 19 is raised straight.

The lead frame 21 can be easily formed by punching with a punching machine or the like. Note that it goes without saying that the mutual spacing between the end face abutting portions 19 which are straightly raised is equal to the mutual spacing between the end faces where the through holes 11 of the ferrite core 12 open.

Next, by fitting the protruding part 14 of the conductor 13 inserted into the through hole 11 into the notch part 15 of the end surface abutting part 19,
The ferrite core 12 is attached to the lead frame 21.

Next, the connecting portion 22 between the lead frame 21 and the side contact portion 20 is cut using an appropriate cutting means. After cutting, the side abutting portion 20 extends in the opposite direction to the side surface of the ferrite core 12, so the side abutting portion 20 is aligned with the boundary line between the side abutting portion 20 and the end face abutting portion 19. The bead inductor shown in the second figure has an L-shaped locking plate 18 formed by bending the conductor 13 by 180° at 23, and firmly holds the conductor 13 by bringing the side abutment '2dS20 into close contact with the end face of the ferrite core 12. Get 10.

According to the manufacturing method described above, the bead inductor 10 shown in FIG. 2 can be manufactured by simple process operations such as insertion, punching, mounting, cutting, and bending without requiring a plating process to form an electrode layer. can be manufactured. With the above manufacturing method, the bead inductor 10 can be easily mass-produced using an automatic assembly machine.

Although one embodiment of the invention of this application has been described in detail above, the invention of this application is not limited to the above embodiment, and may be modified as appropriate without changing the gist of the invention of this application. Needless to say, the present invention can be modified and implemented.

In the embodiment described above, the holding of the conductor 13 by the locking plate 1B is achieved by fitting the end of the conductor 13 into the U-shaped notch 15 provided in the locking plate 18.
Alternatively, this may be achieved by connecting the locking plate 18 with or without the notch 15 and the end face of the conductor 13 by soldering or welding (furthermore, the notch 15 conductor 1 to the person who opened it in the locking part that does not have
This may be achieved by inserting the ends of the holes 3 and then crimping the holes.

As detailed above, according to the invention related to this 1gK,
A bead inductor with a simple configuration that does not require lead wires, which can securely hold the conductor and simply place it on a printed wiring board for electrical connection, and rigorous processing using an automatic assembly machine that eliminates the need for a plating process. It is possible to provide a method for manufacturing a bead inductor that is inexpensive and easy to manufacture without requiring precision.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing a conventional bead inductor, FIG. 2 is a perspective view showing a bead inductor as an embodiment of the present invention, and FIGS. 3 to 5 are beads as an embodiment of the present invention. FIG. 3 is a perspective view showing a method of manufacturing an inductor. 10... Bead inductor, 11... Penetrator L
1 frame).

Claims (3)

[Claims] (1) A ferrite core having a through hole, a conductor having protrusions protruding from openings at both ends of the through hole and inserted into the through hole, and providing the opening while holding the protrusions. A bead inductor characterized by having a pair of locking portions that are in close contact with a ferrite core surface. (2) The ferrite core is cylindrical, and both end faces of the conductor and the locking portion are electrically connected to each other by soldering or welding. bead inductor. (3) The bead inductor according to claim 1, wherein the locking portion inserts a protruding portion of the conductor and holds it by caulking. (4) A conductor longer than the length of the through hole is inserted into the through hole of a ferrite core having a through hole, and the conductor is arranged in the through hole such that both ends of the conductor protrude from both end openings of the through hole. Then, the ends of the conductor protruding from the openings at both ends of the ferrite core are held by a pair of locking portions facing each other on the frame, and then the frame and the locking portions are cut. A method for manufacturing a bead inductor characterized by: