JPH0644532B2 - Small coil - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a small coil used in various electronic devices.

2. Description of the Related Art Conventionally, with this type of small coil, for example
The one described in Japanese Patent Publication No. 920 is configured as shown in FIGS.

That is, the coil 12 is wound around the drum-shaped core 11, and the bent magnetic alloy agent 13 having the cut-and-raised portion 14 protruding outward is formed on a part of the outer peripheral end surface of the drum-shaped core 11. The coil leads 12 are fixed in close contact with each other at positions facing each other, and the gap 15 between the facing magnetic alloy materials 13 causes the coil leads 12
a and 12b are drawn out, the coil leads 12a and 12b are connected and fixed to the side end surface portion 16 of the magnetic alloy material 13 by soldering or the like, and the magnetic alloy material 13 is fixed from the gap portion 15 with an adhesive or the like.

In the small coil shown in FIGS. 5A to 5E, two parallel terminal grooves 18a and 18b are provided on one brim of the drum core 18 having brims on both ends, and the terminal grooves 18a and 18b are provided.
The terminal 17 is fitted in and fixed with an adhesive or the like. A coil 19 is wound around the drum core 18, and coil leads 19a and 19b at both ends are respectively wound around the terminals 17 and wired to be soldered.

In the conventional example of FIG. 4 configured as described above, the coil 12 is wound around the drum core 11 and the cut-and-raised portion 14 that projects outward is provided on the outer peripheral end surface. Folded magnetic alloy material 1
3 are closely fixed on the circumferential side surfaces of the drum-shaped core 11 so as to face each other, and the coil leads 12a and 12b are drawn out from the gap portions 15 of the facing magnetic alloy material 13 to the side end surface portion 16 of the magnetic alloy material 13. As shown in FIG. 6, the drum core 1 has a substantially closed magnetic circuit structure in which the electric circuit is formed by connecting and fixing 12a and 12b by soldering or the like.
As shown in FIG. 7, the change in the inductance of the electrical performance is large due to the gap between the circumferential side surface of No. 1 and the inner side surface of the magnetic alloy material 13, and the inductance tolerance is 30% to 4%.
0% is required. Such an inductance tolerance causes a large variation as a signal circuit constant component, making it unusable. As a method of reducing the variation in the inductance, the magnetic alloy material 13 is removed to form an open magnetic circuit structure, the variation in the inductance is small, and the inductance tolerance can be about 5% to 10%, which can be used as a signal circuit constant component. However, by removing the magnetic alloy material 13, the coil leads 12a and 12b cannot be connected and fixed, and it is difficult to mount and connect the coil leads 12a and 12b to the printed circuit board, which is difficult to work. Is also at a disadvantage.

Further, in the conventional example shown in FIG. 5, two parallel terminal grooves 18a, 1 are provided on one brim of the drum type core 18 having brims on both ends.
8b is provided, the terminals 17 are fitted into the terminal grooves 18a, 18b and fixed with an adhesive or the like, the coil 19 is wound around the drum type core 18, and the coil leads 19a, 19b at both ends are provided.
In the open magnetic circuit structure in which each of the terminals is wound around and wired and soldered, there is little change in the inductance in the conventional example, and there is no problem, but the terminal 17 is the coil leads 19a, 1
The terminal grooves 18a and 18b of the drum-shaped core 18 are connected to the printed circuit board connecting terminals by the small mechanical stress when the printed circuit board is connected.
The ends of the coil 17 and the root of the drum-shaped core 18 of the terminal 17 are distorted by cracks or the like in the bonding portion fixed with an adhesive, and the coil leads 19a and 19b are cut. Further, in recent years, when the surface mounting has been progressing and the automatic mounting mounting is performed, when the opposite side of the terminal fixing end surface of the drum type core 18 is sucked by the suction nozzle and mounted on the printed circuit board, the drum type core 18 is mounted.
There were quality problems such as cracks and cracks in the brim of the adsorption part.

Means for Solving the Problems In order to solve the above problems, the present invention provides a fixing portion and a terminal lead-out portion and a lead extended outward from both ends of the fixing portion at an angle of 45 degrees with respect to respective extension lines. The terminal consisting of the connecting part and the trapezoidal fixing part of the punched part consisting of the shearing part and the breaking part of the metal punching in the terminal groove formed in one brim of the drum type core is shaped like an inverted wedge to the terminal groove. A long hole is provided in the fixing part of this terminal, the tip of the lead wire connecting part is made into a substantially fan shape, and a substantially cylindrical non-magnetic ring for tightly fixing to the peripheral side surface of this drum core is inserted. It is configured to be fitted and fixed.

By configuring as above, the mechanical shearing area of the lead connection part of the terminal and the terminal lead-out part is separated, the mechanical shearing area of the adhesive fixation by the long hole of the terminal fixing part is improved, and the trapezoidal fixing part of the punched part is By fitting and fixing in a reverse wedge shape to the groove, the strength against cracks and cracks in the adhesive fixing part due to the mechanical stress of the terminal lead-out part is increased, and this makes it possible to solve the problem of cutting the coil lead. Cracks and cracks on the drum core due to magnetic ring insertion and fixation can be eliminated and automatic mounting and mounting can be done, and there is little change in inductance due to the open magnetic circuit configuration, and electrical performance as a signal circuit constant component can be improved .

Embodiment An embodiment of the present invention will be described below with reference to FIGS. 1 to 3. In FIG. 1, reference numeral 1 denotes a drum type core having flanges 1a and 1b at both ends (see FIG. 1b), and two concave terminal grooves are provided on an outer end surface of one flange 1a of the drum type core 1. 2 and 3 are formed. Fixing portions 4a and 5a fitted into the terminal grooves 2 and 3 and fixed to the terminal grooves 2 and 3 with an adhesive or the like, and a lead connecting portion protruding from one end of the fixing portions 4a and 5a at an angle of 45 degrees. 4b, 5b and terminals 4, 5 (see FIG. 1a) formed by terminal lead-out portions 4c, 5c projecting at an angle of 45 degrees at positions opposite to the other end on the opposite side are assembled and fixed. (See FIG. 1c).

The fixing portions 4a, 5a of the terminals 4, 5 are punched with an oblong hole 6 as shown in FIG. 3a, and project at an angle of 45 degrees from one end of the fixing portions 4a, 5a. As shown in FIG. 3, the lead connecting portions 4b and 5b are provided with a substantially fan-shaped portion 7 at the tip thereof.

The terminals 4 and 5 may be formed by punching a metal plate into individual pieces, but it is more advantageous to use a metal hoop material for mass production.

A coil 8 is wound around the drum type core 1 (see FIG. 1d).
The coil leads 8a and 8b at the beginning and end of the coil 8 are wound around the lead connecting portions 4b and 5b of the terminals 4 and 5 and connected by soldering or the like, as shown in FIG. 3b. In addition, since the lead connecting portions 4b and 5b have a short protruding portion from the end portion of the flange 1a of the drum core 1, the coil lead 8
When a and 8b are wound around the lead connecting portions 4b and 5b, there is a great risk that they will come off from the lead connecting portions 4b and 5b. Further, as shown in FIG. 3c, the fixing portions 4a, 5 of the terminals 4, 5 fitted in the concave terminal grooves 2, 3 on the outer surface of the one brim 1a of the drum core 1 are formed.
When the metal plate is punched in a, the punched surface is composed of a sheared surface and a fractured surface, and the punched portion of the metal plate has a trapezoidal shape, and the terminals 4 and 5 are fixed to the concave terminal grooves 2 and 3 of the drum core 1. When fitting the parts 4a, 5a, the punching surface side is provided with the terminal grooves 2, 3
When fixed by the adhesive 9 or the like by being fitted to the outside of
The fixing portions 4a and 5a of the terminal 1 are fixed to the terminal grooves 2 and 3 in an inverted wedge shape.

A resin ring 1 as a substantially cylindrical non-magnetic ring shown in FIG. 1e from the side opposite to the terminal fixing end surface of the drum core 1.
0 so that the cutout window portion 10c and the gap portion 10d are located in the terminal lead-out portions 4c and 5c, and the cutout window portions 10a and 10b of the substantially cylindrical resin ring 10 are connected to the lead connecting portions 4b and 5b. The cutout window portion 10 is fitted so as to be located at
An adhesive or the like is applied to and fixed to a and 10b to complete a small coil as shown in FIG.

EFFECTS OF THE INVENTION As described above, the small coil of the present invention is provided with an elongated hole in the fixing portion that is adhesively bonded to the terminal groove as a terminal to be attached to the terminal groove on the outer end surface of one of the drum-shaped cores. ,
The punched surface is fitted and fixed to the outside of the terminal groove, and a lead connecting portion having a substantially fan-shaped tip projecting outward from one end of the fixing portion at an angle of 45 degrees with respect to the extension line, and the fixing portion. Since it has a terminal lead-out portion that protrudes outward at an angle of 45 degrees from the other end, the coil lead connection terminal portion and the printed circuit connection terminal portion can be separated, and the tip has a substantially fan shape. It is possible to prevent the coil lead from coming off,
Extending the shear cross-sectional area of the adhesive bond and fixing part by providing elongated holes for the terminal fixing part and connecting the trapezoidal fixing part of the punching part composed of the shearing part and the breaking part of the metal punching in a reverse wedge shape. Depending on the mounting method, the problem of disconnection due to the mechanical stress of the coil lead due to the reverse wedge effect against the peeling of the fixed part is solved, and high quality and high reliability can be obtained.

Further, by inserting a substantially cylindrical non-magnetic ring on the outer peripheral side surface of the drum core, the brim portion on the upper surface of the drum core is reinforced, and cracks and cracks in the upper brim during automatic mounting on the printed circuit board are also possible. In addition, because of the substantially cylindrical resin ring, the variation of the inductance is 5% to 1 in the open magnetic circuit structure.
A tolerance of 0% is possible, a large effect as a signal circuit constant component is obtained in terms of electrical performance, and cost reduction is also achieved by automation, which is of great industrial value.

[Brief description of drawings]

1A to 1E are perspective views of a small coil according to an embodiment of the present invention during assembly, FIG. 2 is a perspective view of the completed product, and FIGS.
Is a partially enlarged perspective view and partially enlarged cross-sectional view of the same coil, FIGS. 4a to 4c and 5a to 5e are perspective views of a conventional small coil during assembly and a finished product, and FIG. 6 is a portion of a conventional example. FIG. 7 is an enlarged view of the assembly and FIG. 7 is a diagram showing the relationship between the inductance and the gap size. 1 ... drum type core, 1a, 1b ... brim, 2, 3 ...
Terminal groove, 4, 5 ... Terminal, 4a, 5a ... Fixed part, 4
b, 5b ... Lead connecting part, 4c, 5c ... Terminal lead-out part, 6 ... Oblong hole, 7 ... Substantially fan-shaped part, 8 ... Coil, 8
a, 8b ... coil winding start, winding end lead, 9 ... adhesive fixing portion, 10 ... substantially cylindrical resin ring, 10a, 10
b, 10c ... Notched window portion, 10d ... Notched window gap portion.

Claims (1)

[Claims] 1. A long hole is provided in a fixing portion fitted in the terminal groove and fixed with an adhesive in two terminal grooves provided on the outer end surface of one flange of a drum type core having flanges at both ends. A terminal lead-out portion extending outward from one end of the fixing portion at an angle of 45 degrees with respect to the extension line, and an outwardly projecting portion from the other end of the fixing portion at an angle of 45 degrees with respect to the extension line. Each of the terminals consisting of a lead connection part with a substantially fan-shaped tip is fitted with a trapezoidal fixed part of the punched part composed of a metal punching shearing part and a breaking part in a reverse wedge shape to the terminal groove. A substantially cylindrical non-magnetic ring is fitted to a coil body formed by connecting the leads of the coil wound around the drum-shaped core to the lead connecting portions of the terminals. A small coil that does.