JPH0652109U - Coil parts using toroidal core - Google Patents

Abstract

(57) [Abstract] [Purpose] In a coil component in which a winding is wound around a toroidal core, it has a rubber cover with a structure that does not cause misalignment due to winding of the winding, and thus has insulation for encapsulating and fixing the coil component. (EN) Provided is a coil component in which the function of alleviating the pressure on the core generated when the resin shrinks is uniformly exerted on the entire circumference of the core, and the variation in characteristics can be reduced. [Structure] A rubber cover 6 is covered in a core case 2 that houses a toroidal core 1. The rubber cover 6 has an outer peripheral surface portion 6a and both side surface portions 6b facing the outer peripheral surface and both side surfaces of the core case 2, respectively, and has an opening portion 6c in the both side surface portions. The opening 6c on the side surface is opened to cover the core case 2. The winding 3 is wound around the rubber cover 6.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a coil component using a toroidal core such as a noise filter or a choke coil, and more particularly to a component which is sealed and fixed by a resin in a case which is an exterior body.

[0002]

[Problems to be solved by conventional techniques and devices]

 A conventional coil component of this type is shown in FIG. This coil component is used as a choke coil for a noise filter. A toroidal core 1 made of a ferrite molded body is housed in an electrically insulating core case 2, a winding 3 is wound on the core case, and then the core is wound. The case 2 and the winding 3 are coated with a silicon resin to form a buffer layer 4 for alleviating the pressure when the insulating resin for sealing and fixing the coil components is contracted. Reference numeral 5 denotes a terminal material which is an example of a member to which the coil component is attached. A pair of mounting portions 2a projecting from the outer circumference of the core case 2 are provided in a mounting hole 5d in an intermediate portion of the terminal material 5 which is molded in resin. It shows an example of pressing and fixing.

Here, the reason why the buffer layer 4 is formed by applying a silicone resin will be described in more detail. This coil component is housed in a case (not shown) that is an exterior body of the coil component and the insulating resin is used as a case. In the case of filling and fixing by injecting into the inside and hardening, pressure is applied to the ferrite toroidal core 1 as shown by arrows X and Y in FIG. The radial compressive force shown is about twice as large as the axial force shown by the arrow Y, and the core 1 inner peripheral surface is not subject to core compressive force), and the inductance is significantly reduced. This is to prevent this.

As described above, conventionally, the molten silicon resin is applied after winding and dried to form the buffer layer 4, but it is possible to apply the buffer layer 4 to a uniform thickness. However, there is a problem in that the thickness is partially insufficient and the thickness of the buffer layer 4 varies among components, and the degree of reduction in inductance varies. In addition, there is a problem that coating work is required, workability is poor, and there are many management items such as time management for shifting to drying work and management to prevent mutual adhesion of parts during drying. there were.

In order to solve such a problem, the present inventor has developed a coil component with a rubber cover 6x as shown in FIGS. 3 (C) and 3 (D). No. 254 76 is proposed. The rubber cover 6x has an outer peripheral surface portion 6a and both side surface portions 6b facing the outer peripheral surface and both side surfaces of the core case 2, respectively, and is opened at a portion of the outer peripheral portion 6a corresponding to the mounting portion 2a of the core case 2. A portion 6d is provided, and the opening 6d of the outer peripheral portion 6a of the cover 6x is pushed open with a hand or a jig to cover the core case 2, and the winding 3 is passed through the side surface portion 6c of the cover 6 and Wrap it on the outside of the cover 6.

However, when the rubber cover 6X having this structure is used, when the winding 3 is wound, the tightening force of the winding 3 causes the opening 6d side of the rubber cover 6X to move to the winding 3 side as shown by the arrow a. The rubber cover 6X is attracted and displaced, and is deformed so that the top portion b of the rubber cover 6X swells. For this reason, there has been a problem that the stress relaxation action when the encapsulating and fixing insulating resin is contracted becomes non-uniform, which affects the characteristics (inductance) of the coil component. Further, since the top portion b of the rubber cover 6X swells, the top portion b cannot be covered with the encapsulating and fixing insulating resin and is exposed, resulting in a bad appearance.

In view of the above problems, the present invention has a rubber cover in a coil component in which a winding is wound around a toroidal core and has a structure that does not cause a deviation due to winding of the winding. To provide a coil component that has the function of alleviating the pressure on the core generated when the insulating resin for encapsulating and fixing the coil component is contracted uniformly over the entire circumference of the core case and reducing the variation in characteristics. To aim.

[0008]

[Means for Solving the Problems]

 In order to achieve the above object, the present invention provides a coil component using a toroidal core in which a toroidal core is housed in a core case made of a resin molding material, which includes a rubber cover that covers the core case. An outer peripheral surface and both side surfaces facing the outer peripheral surface and both side surfaces of the core case, and opening portions on the both side surface parts, and a winding wound around the outside of the rubber cover. Is characterized by.

[0009]

[Action]

 In the coil component of the present invention, the opening provided in the side surface of the rubber cover is opened to cover the core case so as to cover the entire outer circumference of the core case, and the winding is wound on the outer circumference. Since the rubber cover covers the entire circumference of the core case, the rubber cover does not slip when the winding is wound on the rubber cover.

[0010]

【Example】

 1A is a side view showing an embodiment of a coil component according to the present invention, FIG. 1B is a partially cutaway plan view thereof, and FIG. 1C is a sectional view taken along line EE of FIG. FIG. 2 is a perspective view showing the component structure of this embodiment. 1 and 2, the same reference numerals as those in FIG. 3 indicate the same components, and the core case 2 made of an electrically insulating resin molding has a single-sided opening and a winding 3 at the center as shown in FIG. A cylindrical portion 2b to be inserted is provided, and a pair of push-fitting mounting portions 2a are provided on the outer peripheral surface so as to project, and a ridge 2c for preventing the winding 3 from being displaced is formed on the outer periphery. 2d is a lid of the core case, the core case 2 is made of an electrically insulating resin, and the ferrite toroidal core 1 is housed in the core case 2 and then the stepped fitting portion 2e of the opening surface of the core case 2 is provided. It is fitted to close the opening surface.

Reference numeral 6 denotes a rubber cover according to the present invention, which has an outer peripheral surface portion 6a and both side surface portions 6b facing the outer peripheral surface and both side surfaces of the core case 2 including the lid 2d, Moreover, an opening 6c having an inner diameter substantially equal to the diameter of the cylindrical portion 2b is provided on both side surface portions 6b.

The rubber cover 6 is mounted by accommodating the toroidal core 1 in the core case 2, then closing the opening surface of the core case 2 with the lid 2d, and opening the opening portion 6c of the side surface portion 6b of the rubber cover 6. It is performed by opening with a hand or a jig and covering the entire core case 2. Note that this work may be performed using an automatic mounting machine. Then, as shown in FIG. 1, the winding 3 is wound from above the rubber cover 6, and the attachment portion 2a covered with the cover 6 is attached to the attachment hole 5d of the rectangular portion 5c of the intermediate portion of the terminal material 5. Press fit. In this case, the mounting portion 2a is covered with the rubber cover 6, but since the cover 6 has elasticity, the cover 6 covering the mounting portion 2a contracts and pushes when it is pressed into the mounting hole 5d. Can be fitted. Insert both ends 3a, 3b of the winding 3 into predetermined holes provided in the terminal material 5 and solder them, and set this coil part together with other parts in a predetermined mold and melt it in the mold. The resin is injected and cured to mold. In this case, since the mounting portion 2a of the core case 2 of the coil component is fixed to the terminal material 5, the coil component is not displaced on the terminal material 5 due to the resin injection pressure. After molding the terminal material 5, the terminals 5a and 5b connected to both ends of the winding 3 are formed by cutting the terminal material 5 at the position shown by the line 7 in FIG. 1 (B).

As described above, by covering the core case 2 with the rubber cover 6, the force generated when the mold resin contracts is mainly absorbed by the contraction of the rubber cover 6, and the reduction of the inductance of the core 1 is prevented. It To give a specific example, for a ferrite core with an outer diameter of 13 mm and a width of 6 mm, when only the core case 2 is attached and the rubber cover 6 is not attached, the inductance reduction before and after molding is reduced by about 60%. However, when a rubber cover 6 with a wall thickness of about 1 mm and a JIS hardness standard of about 55 was mounted on the core case 2, the inductance reduction was about 30%, and the JIS hardness standard was about With 35, the reduction was 0%, and a remarkable effect was obtained. From these results, the strength of the rubber used as the cover 6 is preferably about 10 to 50 according to JIS hardness standard.

The present invention can also be used in a common mode choke coil or the like in which a pair of windings 3 are provided on a toroidal core 1.

[0015]

[Effect of device]

 In the present invention, a rubber cover is used to relieve pressure when the resin contracts, and since a rubber cover with a uniform thickness can be obtained, the pressure relieving action does not vary among the parts, and the rubber cover does not vary. The manufactured cover will not be displaced by the windings, a uniform inductance reduction prevention effect will be obtained over the entire circumference of the core case, and reliability will be improved.

Further, since the rubber cover core case is mounted on the core case, it does not require manual work such as resin coating, and can be easily assembled to the core case. There is no need for troublesome management.

[Brief description of drawings]

1A is a side view showing an embodiment of a coil component according to the present invention, FIG. 1B is a partially cutaway plan view thereof, and FIG. 1C is a sectional view taken along line EE of FIG.

FIG. 2 is an exploded perspective view of the present embodiment.

3A is a front view of a conventional coil component, FIG. 3B is an explanatory view of stress applied to a core, and FIG. 3C is a perspective view showing a rubber cover already developed by the present inventor. D) is a front view of a coil component for explaining the problems of the rubber cover.

[Explanation of symbols]

 1 toroidal core 2 core case 2a mounting portion 3 winding 5 terminal material 6 rubber cover 6a outer peripheral surface portion 6b side surface portion 6c opening

Claims (1)

[Scope of utility model registration request] 1. A coil component using a toroidal core in which a toroidal core is housed in a core case made of a resin molding material, comprising a rubber cover for covering the core case, the rubber cover being an outer peripheral surface of the core case. And an outer peripheral surface portion and both side surface portions respectively facing each other and opening portions on both side surface portions, and a winding is wound around the outside of the rubber cover. Coil parts.