JPH0510325Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Purpose of the Invention] (Field of Industrial Application) The present invention relates to an improvement of a toroidal coil device that can be widely used in various industrial fields.

(Prior Art) Among toroidal coil devices, there is one in which the toroidal coil is placed in a vertical position and stored semi-submerged in a box-shaped base, and is attached to, for example, a circuit board through this base. Are known.

In this type, when storing the toroidal coil in the base, a support surface (hereinafter referred to as a support curved surface) with a curvature that fits the coil circumferential surface is formed in advance at the bottom of the base, and the coil circumferential surface The coil is placed on this curved support surface with an adhesive interposed between them to fix them together, and in order to take out the leads related to this coil, two through holes are drilled in the center of the curved support surface in advance. A method is used in which the lead is taken out of the base through the through hole.

(Problems to be solved by the invention) In the toroidal coil device configured as described above, the lead through holes are formed directly on the supporting curved surface, so the adhesive interposed between the coil and the supporting curved surface is It also flows into the through hole, causing a phenomenon in which the lead is fixed in the through hole. Therefore, when the coil device in such a state is attached to a circuit board and soldered, both the leads and the base are firmly fixed to the circuit board.

Therefore, when this circuit board with a coil device is used in equipment that generates heat, for example, electrical equipment for automobiles such as an electric circuit for controlling fuel injection in an engine, the coil will heat up as the temperature inside the car increases. The base made of plastic and synthetic resin expands thermally, and stress is generated due to the difference in thermal expansion between the two, which acts on the coil side as a force that pulls the coil on the base away from the circuit board. However, in some cases, the copper foil may peel off from the circuit board while the leads, circuit board, and soldered part are still integrated, resulting in a situation where the quality of the electrical connection is significantly degraded. I will be inviting you.

This idea was made in view of this situation,
An object of the present invention is to provide a novel toroidal coil device that can maintain high quality electrical connection between a lead and a circuit board even if thermal expansion occurs in the coil or base.

[Structure of the invention] (Means for solving the problem) The structure of the invention for achieving this purpose is to attach a ring-shaped magnetic core to a box-shaped or table-shaped base with a recess for placing the coil. In a toroidal coil device in which a coil with toroidal winding is mounted vertically and the leads of the coil are passed through a lead extraction hole formed in the base and taken out below the base, the diameter of the lead extraction hole is It is formed to be larger than the lead diameter of the coil, and can prevent an adhesive for fixing the coil to the coil mounting recess from flowing into a region between the lead extraction hole and the coil mounting recess. The reason is that a structural adhesive inflow prevention part is provided.

(Function) The function of the present invention based on this configuration is that the adhesive for fixing the coil is not allowed to flow into the through hole when the coil lead is taken out below the base.

(Example) Hereinafter, the present invention will be described in detail based on an example shown in the drawings. Fig. 1 is a perspective external view of an embodiment of the present invention applied to a toroidal coil device with a box-shaped base, Fig. 2 is a sectional view taken along line X-X', and Fig. 3 is FIG. 1 is a top view of the box-shaped base, and FIG. 4 is a sectional view taken along YY' in FIG. 3.

In the figure, reference numeral 1 denotes a coil in which a toroidal winding is applied to a ring-shaped magnetic core, and its structure itself is the same as that of a known coil. 2 and 3 are leads of the coil 1 extending from the hollow part of the coil 1 to the lower left and right sides of the coil;
Reference numeral 4 denotes a box-shaped base that holds this coil 1, and is made of, for example, synthetic resin, and as shown in FIG. A recessed portion 4a and relief wall portions continuous to both ends thereof are formed.

5 and 6 are the box-shaped base 4 at the center portion of the outer surface of the base corresponding to both end surfaces of the coil 1;
A convex portion 7 is formed from the top surface to the bottom surface, and a blocking step portion 7 is formed on the inner surface of these two convex portions 5 and 6, and its position in the height direction is determined to fix the coil 1. The height H (height from the lowest part of the coil mounting recess 4a) is set so that the adhesive applied to the coil mounting recess 4a does not flow into the blocking step 7. Note that the upper space 7a of this blocking step 7
is formed upright upwardly of the box-shaped base 4 as a cylindrical space having a diameter larger than the diameter of a lead extraction hole 8, which will be described later.

Reference numeral 8 denotes lead extraction holes which are respectively drilled from the two blocking step portions 7 toward the lower surface (bottom surface) of the box-shaped base 4, and the diameter thereof is set to be somewhat larger than the diameter of the lead. Reference numeral 9 denotes a plurality of mounting terminals for supporting and fixing the entire coil device (specifically, the base 4) to a member to be mounted, such as a circuit board (not shown). It is formed as a pin that projects downward.

Next, a method of assembling a toroidal coil device having such a box-shaped base structure will be explained.

First, a suitable adhesive is applied to the coil mounting recess 4a of the box-shaped base 4 or a part of the circumferential surface of the coil 1, and the coil 1 is placed vertically and semi-submerged on the coil mounting recess 4a. Attach it in place and fix it by curing the adhesive. At this time, the two leads 2 and 3 are inserted into their respective lead extraction holes 8, pass through the holes 8, and are extracted to the lower surface of the box-shaped base 4.

The toroidal coil device in this state is
It is firmly supported and fixed to the circuit board to be mounted using the two mounting terminals 9, and the leads 2 and 3 are inserted into the lead insertion hole 8 formed in advance on the board side.
The ends of the leads 2 and 3 are soldered to the copper foil pattern of the circuit board on the back side or front side of the board.

In this embodiment, the blocking step 7 serves as an adhesive inflow blocking section, so even if the ambient temperature of the circuit board rises and the coil 1 or the box-shaped base 4 thermally expands, the coil 1 itself will be damaged by the circuit board. Even if the box-shaped base 4 and the lead 2,
3 and 3 only cause free "positional deviation" relative to each other at the lead extraction hole 8, and the stress acting force due to the difference in thermal expansion between the leads 2 and 3 does not reach the soldered portions of the leads 2 and 3.

It should be noted that the leads 2 and 3 are in a state where there is a margin in the length direction from the magnetic core hollow part of the coil 1, that is, the coil 1
Since it extends downward from the base with a predetermined gap with respect to the hollow part of the magnetic core and the end face of the coil, the above-mentioned "mutual misalignment" phenomenon with the box-shaped base 4 occurs. Even in such cases, the "misalignment" can be fully absorbed.

5 and 6 are a perspective external view and a sectional view taken along Z-Z' of an embodiment in which the present invention is applied to a table-like base.

In the figure, 4' has a coil mounting recess 4a on its upper surface.
The table-like bases 11a and 11b are ears formed protrudingly on both sides of the table-like base 4', and lead extraction holes 8 are formed therein.

12a and 12b are partition walls provided in the area between the ears 11a and 11b and the coil mounting recess 4a.

In this embodiment having such a configuration, the partition walls 12a and 12b serve as adhesive inflow prevention parts,
The coil leads 2 and 3 are guided to the lead extraction hole 8 after passing over the partition wall.

FIG. 7 is a perspective external view of an embodiment in which the present invention is applied to another platform base. In the figure,
4'' is a table-shaped base whose upper surface is a coil-placing recess 4a, and 21a and 21b are coil-placing recesses 4a on both sides of the table-shaped base 4''.
The ears are formed protrudingly in the outer region, and the height of the upper surface thereof is such that the coil fixing adhesive applied to the coil mounting recess 4a is the same as that of the ears 21a and 21b.
The height is set at such a height that the lead cannot flow into the lead extraction hole 8 formed in the lead.

In this embodiment with such a configuration, the height of the ear part becomes the adhesive inflow prevention part, and the leads 2 and 3 of the coil pass from the hollow part of the magnetic core to a position away from both end faces of the coil 1. It is guided to the extraction hole 8.

Although several embodiments have been described above, the present invention is not limited thereto, and can be modified in various ways without changing the gist thereof.

For example, the shape and area of the blocking step/ear and the shape of the space above it may be other than the illustrated embodiment, and the material of the base is not limited to synthetic resin; It should be noted that the convex portions formed on both side surfaces of the base are formed as necessary and are not necessarily an essential condition of the present invention.

[Effects of the invention] As mentioned above, when using the present invention, a new toroidal type that can maintain high quality electrical connection between the leads and the circuit board even if thermal expansion occurs in the coil or base. A coil device can be realized.

[Brief explanation of drawings]

Fig. 1 is a perspective external view of an embodiment of the present invention applied to a toroidal coil device having a box-shaped base, Fig. 2 is a sectional view taken along line X-X' shown in Fig. Fig. 3 is a top view of the box-shaped base according to the present invention, Fig. 4 is a sectional view taken along YY' in Fig. 3, and Figs. 5 and 6 are diagrams of the case where the present invention is applied to a table-shaped base. FIG. 7 is a perspective external view of an embodiment of the present invention and a sectional view taken along the Z-Z' line thereof, and FIG. 7 is a perspective external view of an embodiment of the present invention applied to another table-shaped base. 1... Coil, 2, 3... Lead, 4... Box-shaped base, 4', 4''... Table-shaped base, 4a... Recessed part for placing the coil, 5, 6... Convex part, 7... Blocking step, 8...Lead extraction hole, 9...Mounting terminal,
11a, 11b... ears, 12a, 12b... partition walls, 21a, 21b... ears.

Claims (1)

[Claims for Utility Model Registration] (1) A coil consisting of a ring-shaped magnetic core and a toroidal winding is installed vertically on a box-shaped or table-shaped base with a recess for placing the coil, and the leads of the coil are In a toroidal coil device in which a lead is passed through a lead take-out hole formed in the base and taken out below the base, the diameter of the lead take-out hole is formed to be larger than the lead diameter of the coil; The toroidal device is characterized in that an adhesive inflow prevention portion is provided in a region between the coil placement recess and has a structure capable of preventing an adhesive from flowing in for fixing the coil to the coil placement recess. type coil device. (2) The adhesive inflow prevention portions provided on the box-shaped base are located on two inner surfaces of the box facing both end surfaces of the coil, and from the lowest part of the coil mounting recess. The toroidal coil device according to claim 1, which is provided as a blocking step having a predetermined height. (3) The adhesive inflow prevention portion provided on the box-shaped base is a portion protruding from both outer surfaces of the box-shaped base corresponding to both end surfaces of the coil,
The toroidal coil device according to claim 2, which is provided in a convex portion that is elongated from the top surface to the bottom surface of the base. (4) The adhesive inflow prevention portion provided on the table-shaped base is connected to the lead extraction hole provided in ears protruding from both outer surfaces of the table-like base corresponding to both end surfaces of the coil. The toroidal coil device according to claim 1, wherein the toroidal coil device is formed as a partition wall to prevent the adhesive from flowing into a region between the coil mounting recess and the coil mounting recess. (5) The adhesive inflow prevention portion provided on the table-shaped base is arranged so that the adhesive inflow prevention portion provided in the coil mounting recess is attached to ears protruding from both outer surfaces of the table-shaped base corresponding to both end surfaces of the coil. The toroidal coil device according to claim 1, which is provided as a blocking step having a predetermined height from the lowest portion. (6) The lead of the coil extends downward from the base with a predetermined gap between the hollow part of the coil's magnetic core and the end face of the coil. The toroidal coil device according to any one of Item 5. (7) The base is provided with a plurality of attachment terminals for supporting and fixing the base to the member to be attached, on a surface in contact with the member to be attached. 6th
The toroidal coil device according to any one of the above items.