JP2001210524A - Toroidal coil and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a toroidal coil having a configuration, where even though the number of turns of a coil part can be increased and thus the performance can be improved, lead terminals of the coil part can be inserted easily in the mounting holes of a mounting circuit board and mounted and its manufacturing method that allows mass production of the troidal coil with a high degree of efficiency. SOLUTION: This coil configured by coating the entire surface of a core part 19 with a bobbin 7 and by winding a coil part 8 around a core coating part 9 to coat the core part 19 in the bobbin 7. The coil part 8 is formed by means of a coil winding 20, whose cross section is rectangular and is shaped by twisting only both lead terminals 8a, 8b. In manufacturing, the coil winding 20 is shaped, by twisting both lead terminals 8a, 8b of the coil part 8 produced by winding in an air-cored shape, this coil part 8 is inserted into the core coating part 9 from a slit-shaped insertion part 10 in an outer fitted manner.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a toroidal coil used for a rectifier circuit, a noise prevention circuit, a resonance circuit or a high-frequency circuit in various AC circuits, and a manufacturing method capable of efficiently mass-producing the toroidal coil. Things.

[0002]

2. Description of the Related Art As shown in FIGS. 7 and 8, a conventional toroidal coil of this kind covers a whole surface of a core (not shown) with a donut-shaped bobbin 1 having an opening at the center. Generally, the bobbin 1 is formed by winding the coil portions 2 and 3 around the outer peripheral surface of the bobbin 1 by a manual operation of an operator. The toroidal coil shown in FIG.
The toroidal coil shown in FIG. 8 is formed by winding a coil having a rectangular cross section on a bobbin 1 to form a coil portion 3. Both coil parts 2,
3 is a diagram in which each winding is wound in a state of being separated for convenience of illustration, but in actuality, the entire outer peripheral surface of the windings of the coil units 2 and 3 is coated with an insulating resin, The parts 2 and 3 are wound around the bobbin 1 in a state in which the short circuit is prevented by the insulating resin coating and the windings are in close contact with each other.

[0003]

In the toroidal coil shown in FIG. 7, since the coil portion 2 is formed of a winding having a circular cross section, both lead terminals 2a and 2b of the coil portion 2 are inserted and soldered. Hole 4 of mounting circuit board 4 for mounting
There is an advantage that a and 4b can be round holes that can be easily processed, and that the lead terminals 2a and 2b having a round cross section can be easily bent in arbitrary directions and inserted into the mounting holes 4a and 4b. However, the coil portion 2 using the winding having a round cross section has a line contact between the windings even if the coil is wound in a close state with no gap between the windings adjacent to the bobbin 1.
Since a large gap is formed around the contact portion, the number of windings on the bobbin 1 having a predetermined shape is reduced, and there is a limit in improving the performance of the toroidal coil. On the other hand, coil part 2
In order to secure the predetermined number of turns, the size of the toroidal coil itself cannot be reduced.

On the other hand, in the toroidal coil shown in FIG. 8, since the coil portion 3 is formed by using a winding having a rectangular cross section, the number of windings can be increased by bringing the thin sides of the winding into close contact with each other. can do. However,
The mounting holes 4c and 4d of the mounting circuit board 4 for inserting and soldering the two lead terminals 3a and 3b of the coil portion 3 are as follows.
It is necessary to form a square hole which is difficult to machine as compared with a round hole, and it is not easy to position the lead terminals 3a, 3b having a rectangular cross section in the mounting holes 4c, 4d formed by the square holes. Is very difficult. This is because it is easy to bend the lead terminals 3a and 3b having a rectangular cross section in the direction of the thin arrow A, but it is very difficult to bend the lead terminals 3a and 3b in the direction of the thick arrow B.

In any of the toroidal coils described above, since the bobbin 1 has a donut shape, the coil portions 2, 3
However, there is a problem that the winding operation of the coil units 2 and 3 cannot be mechanized and mass-produced with high efficiency because the winding operation of the bobbin 1 cannot be depended on the manual operation of the operator.

In view of the above, the present invention has been made in view of the above-mentioned conventional problems, and the lead number of the coil portion is increased by increasing the number of turns of the coil portion to improve the performance and reduce the size. It is an object of the present invention to provide a toroidal coil having a configuration that can be easily inserted into the mounting hole and mounted thereon, and a manufacturing method capable of efficiently mass-producing the toroidal coil.

[0007]

To achieve the above object, a toroidal coil according to the present invention comprises a core, a bobbin covering the entire surface of the core, and a core covering the core in the bobbin. And a coil portion wound around the covering portion.The coil portion is formed using a winding having a rectangular cross section, and is subjected to a shaping process in which only the two lead terminals are twisted. It is characterized by having.

In this toroidal coil, since the coil portion is formed by using a winding having a rectangular cross section, it is possible to improve the performance by increasing the number of turns of the winding of the coil portion on a relatively small bobbin. it can. Also, when mounting the mounting circuit board, the lead terminals subjected to the twisting shaping process can be freely and easily bent in any direction. It can be very easily inserted into the mounting hole.

In the toroidal coil of the present invention, it is preferable that both lead terminals of the coil portion are formed into a shape that is twisted in a spiral shape. Thus, the spirally twisted lead terminal can be freely and more easily bent in any direction.
In addition, since the lead terminal is deformed into a substantially circular cross section by twisting a winding having a rectangular cross section in a spiral shape, the mounting hole of the mounting circuit board can be a round hole,
There is an advantage that the boring of the circuit board is facilitated. In addition, the lead terminals are improved in bending strength by being twisted in a spiral shape, and are not easily deformed unless a force is applied, so that handling is easy.

[0010] The method for manufacturing a toroidal coil of the present invention comprises:
A step of manufacturing a substantially C-shaped core in plan view having a slit-shaped notch in a part of the cylindrical body; and a substantially C-shaped core in plan view covering the entire surface of the core. The covering portion, a cylindrical boss portion concentrically located inside the core covering portion, and the boss portion extending from one side surface of the slit-shaped insertion portion in the core covering portion to the boss portion in a flush arrangement. Manufacturing a bobbin integrally provided with a connecting portion that connects the core covering portion, and a process of manufacturing a coil portion in which windings are wound in an air core shape; Twisting and shaping, and fitting the coil portion from the slit-shaped insertion portion to the core coating portion of the bobbin attached to the bobbin support mechanism by fitting the boss portion to the support shaft portion. So that the coil part is moved to the core. It is characterized by comprising a step of winding the covering portion.

In this method of manufacturing a toroidal coil, the coil portion can be manufactured by winding the winding in a separate, mechanized process to form an air core, and then subjecting the lead terminal to a shaping process. The coil portion can be automatically wound by being inserted into the core coating portion of the bobbin attached to the support shaft portion of the bobbin support mechanism via the boss portion from the slit-shaped insertion portion to the outside. Therefore, in this toroidal coil, both the production of the coil portion and the winding of the coil portion around the bobbin can be performed by a simple automatic process that is mechanized, and the toroidal coil of the present invention can be mass-produced with high efficiency. .

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view showing a toroidal coil according to one embodiment of the present invention. The toroidal coil includes a C-shaped core portion described below in plan view and a bobbin 7 covering the entire surface of the core portion.
And a coil section 8 wound around a core section via a bobbin 7.

The bobbin 7 has a core covering portion 9 covering the core portion, and a slit-like insertion portion 10 formed in a part of the core covering portion 9 so as to correspond to the C-shaped core portion in plan view.
And a cylindrical boss portion 11 provided concentrically inside the core covering portion 9, and a connecting portion 12 connecting the boss portion 11 and the core covering portion 9 are integrally formed. The connecting portion 12 extends from the core covering portion 9 so as to be flush with one side surface of the slit-shaped insertion portion 10 and is connected to the boss portion 11. Locking pieces 13 and 14 that protrude outward along one side surface of the slit-shaped insertion portion 10 are integrally formed from both surfaces in the thickness direction of the core coating portion 9.

The bobbin 7 has a core coating 9
At a position near the other surface of the slit-shaped insertion portion 10 on one surface in the thickness direction, a protrusion 17 for a stopper having a triangular shape in a side view is formed so as to be inclined upward and inward. Further, the inner surface of the boss portion 11 has an engaging groove 1 extending along the cylinder center direction.
8 are provided. The bobbin 7 is formed integrally with a C-shaped core by insert molding with a resin. The toroidal coil of this embodiment is
With the above-described configuration of the bobbin 7, the assembling process can be automated and mass production can be performed with extremely high efficiency, which will be described later.

The coil portion 8 is formed by winding a winding having a rectangular cross section similar to that shown in FIG. 8 around the core coating portion 9 of the bobbin 7 so that the windings are in close contact with each other. . Both lead terminals 8a, 8b in the coil portion 8
Is twisted in a spiral shape, as if twisted. Therefore, in this toroidal coil, since the coil portion 8 is configured by using a winding having a rectangular cross section, the number of turns of the winding of the coil portion 8 on the bobbin 7 having a predetermined shape is increased to improve performance. In addition to achieving downsizing, the lead terminals 8a and 8b are spirally twisted, so that the lead terminals 8a and 8b are
8b can be bent freely and easily in any direction and can be very easily inserted into the mounting hole of the mounting circuit board.
Further, since the lead terminals 8a and 8b are deformed into a substantially circular cross section by spirally twisting a winding having a rectangular cross section, the mounting holes of the mounting circuit board can be round holes. There is an advantage that drilling is easy. Moreover,
Since the lead terminals 8a and 8b are twisted in a spiral shape, the bending strength is improved, and the lead terminals 8a and 8b are not easily deformed unless a force is applied.

Next, a method for manufacturing the toroidal coil will be described in the order of steps. FIG. 2 is a perspective view showing the core 19. The core portion 19 is formed of a material having a high relative magnetic permeability characteristic into a substantially cylindrical shape having a slit-shaped notch portion 19a and having a substantially C-shape in plan view. Although not shown, an epoxy or nylon paint or varnish as an electrical insulator is applied to the surface of the core portion 19 to a thickness not less than that required by the Electrical Appliance and Material Control Law, etc. A layer is formed.

FIG. 3A is a perspective view showing the bobbin 7 formed by insert formation so as to cover the entire surface of the core portion 19, and FIG. 3B is a partially cutaway perspective view of the bobbin 7. Show. The bobbin 7 includes the core coating 9 described above,
The slit-shaped insertion portion 10, the boss portion 11, the connection portion 12, the pair of locking pieces 13, 14, the stopper projection 17, and the engagement groove 18 are integrally formed. The resin for molding the bobbin 7 is a material suitable for insert molding the core portion 19 and suitable for electrically insulating the core portion 19 and the coil portion 8 from each other, and suitable for use environment. Any suitable molding resin may be used, such as PBT or PET as a heat-resistant resin.

FIG. 4A is a perspective view showing a manufacturing process of the coil unit 8, and FIG. 4B is a perspective view showing the coil unit 8 in a completed state. As shown in (a), the coil portion 8 includes a cylindrical jig 22 formed by a winding device (not shown) formed by a cylindrical winding member 21 through which a winding 20 having a rectangular cross section is inserted.
Is wound around the jig 22 to form an air-core shape. When the required number of windings of the winding 20 is completed, both ends of the portion to be the lead terminals 8a and 8b are sandwiched by a pair of chucking members 23a, 23b, 24a and 24b, respectively, and the leading end side is sandwiched. Chucking member 2
4a and 24b are rotated in one direction indicated by an arrow.

As a result, the lead terminals 8a and 8b are spirally twisted. Thereafter, when the jig 22 is pulled out, the air-core-shaped coil portion 8 shown in (b) is completed. The coil portion 8 is formed by using a winding 20 which is electrically insulated with an enamel or the like on a surface of a wire having a rectangular cross section as a general electric appliance. The winding 20 may have any of a rectangular cross section, a trapezoidal shape, and a rectangular cross section.
What is necessary is just to select the thing of the cross-sectional shape suitable for winding on the core coating part 9 of.

FIG. 5 is a perspective view showing a bobbin support mechanism 23 in a mounting device for mounting the coil portion 8 to the core covering portion 9 of the bobbin 7 so as to be externally fitted thereto, and the bobbin 7 before being mounted thereon. The bobbin support mechanism 23
A rotating shaft 24 having a diameter larger than the inner diameter of the through hole 16 of the cylindrical boss portion 11; an outer diameter that can be fitted into the through hole 16 of the boss portion 11; A spindle 27 having the same length and projecting concentrically from the upper end surface of the rotating shaft 24 and a female screw hole 28 formed from above in the center of the spindle 27. And a screw 29 for performing the operation. The shaft 27
On the outer surface, an engaging strip portion 30 which can be engaged with the engaging groove 18 of the boss portion 11 is formed along the axial direction.

The bobbin 7 covering the core 19
Are positioned in such a manner that the engagement grooves 18 are fitted so as to be able to fit into the engagement stripes 30, and the through holes 16 of the boss 11 are
The boss 11 is rotated while the support shaft 27 is inserted into the shaft 24.
The engagement groove 18 and the engagement strip portion 3
It is attached to the bobbin support mechanism 23 so as to rotate integrally with the rotation shaft 24 by engagement with the rotation shaft 24. At this time, the upper surfaces of the boss 11 and the support shaft 27 are substantially flush with each other. Further, the bobbin 7 has a screw 29 formed in the female screw hole 2 of the support shaft 27.
As shown in FIG. 6, by being screwed and fastened to 8, it is fixed to the bobbin support mechanism 23 so as not to come off.

Subsequently, as shown in FIG. 6, the bobbin 7 in the fixed state is rotated by the rotation shaft 24 of the bobbin support mechanism 23 in the direction of the arrow, so that the rotation shaft 2
4 and is rotated in the direction of the arrow. On the other hand, the air-core-shaped coil portion 8 is transported in the direction of the arrow while being held by a feed mechanism (not shown), and is inserted into the core coating portion 9 from the slit-shaped insertion portion 10 of the bobbin 7 in an externally fitted state. . At this time, the coil portion 8 smoothly and sequentially climbs over the stopper projection 17 while sliding on the inclined surface of the stopper projection 17 that has an upward slope in the transfer direction of the coil portion 8.

The rotating shaft 24 starts rotating at a preset timing and at a predetermined rotational speed with respect to the start of the transfer of the coil unit 8, and rotates and stops for a preset time. When the rotation shaft 24 stops rotating, the leading end of the coil portion 8 in the transfer direction is a pair of locking pieces 1.
The rear end of the coil portion 8 in the transfer direction rides over the stopper projection 17 and contacts the end face of the stopper projection 17. Therefore, the coil portion 8
Both ends are prevented from falling off by a pair of locking pieces 13 and 14 and a stopper projection 17, and are held in a state of being fitted to the core coating 9. This makes it possible to completely automate the step of winding the coil portion 8 around the core covering portion 9 of the bobbin 7. Finally, the bobbin 7 around which the coil portion 8 is wound is removed from the spindle portion 27 by loosening the screw 29 and then removed from the spindle portion 27, and the coil portion 8 is shaped into a required shape. Thus, the toroidal coil of the embodiment shown in FIG. 1 is obtained. The bobbin support mechanism 23 has the following bobbin 7
Are attached in the same procedure as described above, and thereafter, the same steps as described above are repeated.

In the above-described method for manufacturing a toroidal coil,
An air-core coil portion 8 formed in a separate mechanized process is
Since the core portion 19 can be automatically wound around the core covering portion 9 of the bobbin 7 obtained by insert molding by a mechanized process, there is no need for a manual process by an operator, and the toroidal coil can be efficiently manufactured. Mass production is possible. Further, the bobbin 7 is attached to the bobbin support mechanism 23 in a state where the winding of the coil portion 8 is not hindered by the boss portion 11 integrally formed using the internal space of the core covering portion 9 around which the coil portion 8 is wound. And is positioned so as to rotate integrally with the rotation shaft 24 by the engagement groove 18 formed in the boss portion 11. The coil portion 8 wound around the core covering portion 9 is held in a state of being prevented from falling off from the core covering portion 9 by a pair of locking pieces 13 and 14 and a projection 17 for stopper. Therefore, by utilizing various shapes integrally formed on the bobbin 7, mechanization of the assembling process of the toroidal coil can be achieved, and a required toroidal coil can be obtained by a simple process.

As the means for fixing the bobbin 7 attached to the bobbin support mechanism 23, the case where the screw 29 is used in the above embodiment is exemplified, but the attachment and detachment to the support shaft 27 is easier than the screw 29. The mass productivity can be further improved by using other known means.

The protruding lengths C and D of the two locking pieces 13 and 14 of the bobbin 7 shown in FIG.
If the thickness of the coil portion 8 is set to be larger than that of the coil portion 8, it is possible to more reliably prevent the coil portion 8 from coming off from the core coating portion 9 and to mount the completed toroidal coil on the mounting circuit board 4 or the like. In addition, since the coil portion 8 can be supported in a state of being floated from the surface of the mounting circuit board 4, there is an advantage that the heat radiation characteristics of the coil portion 8 are improved. Further, the provision of the two locking pieces 13 and 14 protruding on both sides of the core covering portion 9 as in the above-described embodiment, however, makes the mounting surface for mounting the toroidal coil on the mounting circuit board 4 or the like. Is obtained.

It is to be noted that, even if only one of the locking pieces 13 and 14 is not provided or the locking piece 13 is not provided at all, the position of the distal end of the coil portion 8 which is externally fitted to the core coating portion 9 and the prevention of withdrawal are as follows. Since it can be performed by the connecting portion 12, no particular trouble occurs. Further, if the height E of the contact surface of the stopper projection 17 having the inclined surface with which the coil portion 8 comes into contact is set to at least 1/10 or more of the thickness of the coil portion 8, the coil portion 8 can be securely pulled out. I can stop it.

[0028]

As described above, according to the toroidal coil of the present invention, since the coil portion is formed by using a winding having a rectangular cross section, the number of turns of the winding is increased to improve the performance. The miniaturization can be achieved and, in addition, the lead terminal of the coil portion is shaped by twisting, so that the lead terminal can be freely and easily bent in an arbitrary direction to form the mounting circuit board. It can be very easily inserted into the mounting hole.

Further, according to the method of manufacturing a toroidal coil of the present invention, the coil portion is formed into an air-core shape by winding a coil in another mechanized process, and then twisted to the lead terminal portion. The coil part is automatically wound by inserting the coil part from the slit-shaped insertion part into the outside fitting state to the core coating part of the bobbin attached to the spindle part of the bobbin support mechanism via the boss part. Can be worn. Therefore, in this toroidal coil, both the production of the coil portion and the winding of the coil portion around the bobbin can be performed by a simple automatic process that is mechanized, and the toroidal coil of the present invention can be mass-produced with high efficiency. .

[Brief description of the drawings]

FIG. 1 is a perspective view showing a toroidal coil according to an embodiment of the present invention.

FIG. 2 is a perspective view showing a core part in the toroidal coil.

FIG. 3A is a perspective view showing a bobbin in the toroidal coil, and FIG. 3B is a partially broken perspective view of the bobbin.

FIG. 4A is a perspective view showing a manufacturing process of a coil part in the toroidal coil, and FIG. 4B is a perspective view showing the coil part in a completed manufacturing state.

FIG. 5 is a perspective view showing a state in which the bobbin is attached to the bobbin support mechanism in the process of manufacturing the toroidal coil.

FIG. 6 is a perspective view showing a state where the coil unit is attached to the bobbin in the process of manufacturing the toroidal coil.

FIG. 7 is a perspective view showing a state in which a conventional toroidal coil is mounted on a mounting circuit board.

FIG. 8 is a perspective view showing a state in which another conventional toroidal coil is mounted on a mounting circuit board.

[Explanation of symbols]

 Reference Signs List 7 bobbin 8 coil part 8a, 8b lead terminal 9 core covering part 10 slit-like insertion part 11 boss part 12 connecting part 19 core part 19a slit-like notch part 20 winding 23 bobbin support mechanism 27 support shaft part

Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat II (Reference) H01F 41/06 H01F 41/06 A (72) Inventor Yozo Ishimura 1006 Ojidoma, Kazuma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (72) Inventor Shinichi Sakai 1006 Kazuma Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (72) Inventor ▲ Yoshi ▼ Morihira 6-25 Koumecho, Kita-ku, Osaka F-term (Reference) 5E002 AB01 AB04 AD01 5E043 AA06 AB01 EA01 EA02 EA10 5E070 AA01 AB10 BA15 CA16 CA20 DA03 DA20 EA06

Claims (3)

[Claims] 1. A coil comprising: a core; a bobbin covering the entire surface of the core; and a coil wound around a core covering portion of the bobbin covering the core. The toroidal coil, wherein the portion is formed using a winding having a rectangular cross section, and a shaping process for twisting only both lead terminals is performed. 2. The toroidal coil according to claim 1, wherein both lead terminals of the coil portion are formed into a spiral shape by twisting. 3. A step of manufacturing a core portion having a substantially C-shape in plan view having a slit-shaped notch portion in a part of a cylindrical body, and a substantially planar view covering the entire surface of the core portion. A C-shaped core covering portion, a cylindrical boss portion concentrically located inside the core covering portion, and a flat surface extending from one side surface of the slit-shaped insertion portion to the boss portion in the core covering portion. Manufacturing a bobbin integrally provided with a connecting portion for connecting the boss portion and the core covering portion; and manufacturing a coil portion having windings wound in an air-core shape; and Applying a twisting process to both of the lead terminals, and inserting the coil portion through the slit-shaped portion through the core coating portion of the bobbin attached to the bobbin support mechanism by externally fitting the boss portion to a support shaft portion. By transferring to fit outside from the part, Method for manufacturing a toroidal coil, characterized in that it comprises a step of winding the pole tip on the core covering portion.