JPH11307382A - Manufacture of coil device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the deformation of a coil caused by forming pressure without having the mold cost increased. SOLUTION: A coil 12 which is wound on a bobbin 10 is formed of fusion lines 19 obtained by coating conductors 19A with thermosetting resins 19B having adhesive property. When the coil 12 is heated, the thermosetting resins 19B in integrated states by adhesion power are thermally set and the coil 12 is solidified. The coil 12 and the bobbin 10 are set in a mold for secondary formation and a melted forming material is injected. At that time, although a partially high forming pressure operates on the outer periphery of the coil 12 except the coil 12 is solidified. Thus, deformation is prevented by forming pressure.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for manufacturing a coil device.

[0002]

2. Description of the Related Art FIG. 6 shows a manufacturing process of a conventional coil device a disclosed in Japanese Patent Laid-Open No. Hei 5-190348. At the time of manufacture, first, a resin-formed bobbin b
, A terminal fitting e is attached to a terminal attaching portion d projecting from the bobbin b, and a terminal of a lead wire f extending from the coil c is connected to the terminal fitting e. Next, this is set in a secondary molding die g, and a molding material is injected, whereby a cylindrical protective layer portion h surrounding the outer peripheral surface of the coil c and a connector portion surrounding the terminal mounting portion d. and i. At the time of secondary molding, as shown in FIG. 7, gates j are provided at a plurality of locations along the outer circumference of the coil c, and the molding material injected into the mold g from these gates j is applied to the outer circumference of the coil c. And flows toward the terminal mounting portion d.

[0003]

Among the flow paths of the molding material, the path along the outer circumference of the coil c has a smooth arc shape, whereas the path from the coil c to the terminal mounting portion d is bent. As a result, the molding pressure is also increased, and there is a possibility that the coil is partially deformed into a chevron shape n as indicated by a chain line in FIG. As a means for avoiding the deformation of the coil c, it is conceivable to increase the number of gates j to reduce the molding pressure of the secondary molding die g. In the present application, not only does the structure of g become complicated and the mold cost increases, but also the problem that the material cost increases due to an increase in the amount of the liner that is hardened and discarded in the gate j and increases. The present invention has been made in view of the above circumstances, and has as its object to prevent deformation of a coil due to molding pressure without increasing die cost.

[0004]

According to a first aspect of the present invention, there is provided a method of manufacturing a coil device in which a coil is set in a mold and a molding material is injected to form an insulating protective layer on the outer periphery of the coil. In this case, the coil is solidified with a resin prior to the injection of the molding material. According to a second aspect of the present invention, in the first aspect, the coil is solidified while being wound around a bobbin, and the bobbin is positioned and set in the mold.

According to a third aspect of the present invention, in the second aspect of the invention, the bobbin has a structure in which a terminal mounting portion is provided.
The terminal fitting attached to the terminal attaching portion and the lead wire extending from the coil are connected and set in the mold. According to a fourth aspect of the present invention, in any one of the first to third aspects of the present invention, the resin is used to solidify the coil with the resin only in a region where a molding pressure is maximum in a flow path of the molding material along the coil. Configuration.

[0006] The invention of claim 5 is the invention of claims 1 to 3.
In any one of the inventions described above, the coil is formed into a fusion line formed by covering a conductor with a thermosetting resin having an adhesive, and the fusion line is heated to solidify the coil. According to a sixth aspect of the present invention, in any one of the first to fourth aspects, the resin is applied to an outer periphery of the coil and is impregnated in a gap between windings of the coil to solidify the coil. And

[0007]

<Operation and effect of the invention><Invention of claim 1> Since the coil is solidified by resin, deformation of the coil due to molding pressure can be prevented. In addition, since the coil is solidified, the molding pressure can be increased, and the number of gates can be reduced, and the amount of liner that is hardened in the gates and wasted can be reduced. <Invention of Claim 2> Since the coil is solidified in a state wound around the bobbin and is set in the mold, the positioning of the coil in the mold is ensured.

<Invention of Claim 3> Since the terminal fitting is fixed to the terminal mounting portion, the position of the terminal fitting in the mold is stabilized. <Invention of Claim 4> Compared with the case where the entire coil is solidified, the amount of resin used can be reduced. <Invention of claim 5> Since the coil can be solidified only by heating, the workability is good. <Invention of claim 6> Since the resin is applied to the outer periphery of the coil and impregnated into the gap between the windings, only the necessary portion of the coil can be partially solidified, and the cost of the resin can be reduced. It is possible.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First Embodiment A first embodiment of the present invention will be described below with reference to FIGS. As shown in a cross section in FIG. 2, the coil device A has a resin-made bobbin 10 having a cylindrical shape and having flanges 11 protruding at both ends, and a coil 12 wound around the outer periphery of the bobbin 10. From the flange portion 11 of FIG.
To an upper side in FIG. 3);
A terminal fitting 14 fixed to the terminal mounting portion 13, a lead 15 extending from both ends of the coil 12 and connected to the terminal fitting 14, and a resin protective layer 1 surrounding the coil 12.
6, terminal mounting portion 13 and lead wire 15 along the terminal mounting portion 13
And a connector 18 surrounding the terminal fittings 14.

Next, the manufacturing process of the coil device A will be described. First, in a primary molding step, the bobbin 10 and the terminal mounting portion 13 are integrally formed using a mold (not shown), the coil 12 is wound around the bobbin 10, and the terminal fitting 14 is fixed to the tip of the terminal mounting portion 13, Further, the lead wire 15 extending from the coil 12 is connected to the terminal fitting 14 along the side surface of the terminal mounting portion 13. Here, the coil 12 will be described. As shown in FIG. 4A, the coil 12 is formed by winding a fusion wire 19 formed by covering a conductor 19A such as a copper wire with an adhesive thermosetting resin 19B in an annular shape. The thermosetting resins 19B of the adjacent fusion wires 19 are integrated with each other by an adhesive action. The coil 12 composed of the fusion wire 19 is
Is heat-treated in a state of being wound around. Then, FIG.
As shown in (b), the thermosetting resin 19B is thermoset in an integrated state, and the coil 12 is entirely solidified by the curing force of the thermosetting resin 19B. Also, the lead wire 15 made of the same fusion wire 19 as the coil 12 is solidified along the side surface of the terminal mounting portion 13.

After the coil 12 is solidified in this way, the bobbin 10 is set in the secondary molding die 20. The secondary molding die 20 includes a pair of male dies 21 and female dies 22. The male mold 21 has a cylindrical positioning portion 21A fitted on the inner periphery of the bobbin 10, and a connector portion forming cavity 21B for forming the connector portion 18. On the other hand, the female mold 22 has a concentric circular protective layer molding cavity 22A spaced a predetermined distance from the outer periphery of the coil 12, and an extension molding surrounding the terminal mounting portion 13 at a predetermined space. Cavity 22B and injection cylinder 23
Primary sprue 22C connected to the nozzle 23A, a pair of secondary sprues 22D extending from the primary sprue 22C in an arc shape concentric with the coil 12, and each secondary sprue 22C.
It has a tertiary sprue 22E extending concentrically inward from the tip of D, and a plurality of gates 22F extending from the tertiary sprue 22E to the protective layer molding cavity 22A (see FIG. 3).

When the bobbin 10 is set in the secondary molding die 20, as shown in FIG.
The bobbin 10 and the coil 12 are tightly fitted to the outside.
Are positioned in the radial direction with respect to the male mold 21. Also,
While the left end surface of the bobbin 10 contacts the female mold 22,
When the cover 13A fitted to the tip of the terminal mounting portion 13 abuts against the inner wall surface of the connector portion forming cavity 21B, the axial movement of the bobbin 10 is restricted. In this set state, the molding material melted from the injection cylinder 23 is supplied to the inside of each sprue 22C, 22D, 22E and the gate 2
A predetermined pressure is supplied through the 2F into the protective layer molding cavity 22A. The molding material supplied here passes through a cylindrical path between the inner wall surface of the protective layer portion forming cavity 22A and the outer peripheral surface of the coil 12, and the extension portion forming cavity 22B and the connector portion forming cavity 21B. Supplied inside. Then, after the molding material has hardened, if the molds 21 and 22 are opened, the coil device A shown in FIG. 2 is obtained.

The flow path of the injected molding material has a cylindrical shape in the protective layer portion forming cavity 22A, so that it can flow relatively smoothly.
Since the path from A to the extension forming cavity 22B is bent at substantially a right angle, the fluidity deteriorates. As a result, a high molding pressure is applied to the outer periphery of the coil 12 in the portion close to the extension forming cavity 22B. Works. But,
Since the coil 12 is composed of the fusion wire 19 and has already been solidified by heating, even if the molding pressure is high, the coil 12 will not be deformed due to it. Therefore, the thickness of the protective layer 16 surrounding the coil 12 becomes uniform over the entire circumference.

As described above, in the present embodiment, since the coil 12 is solidified before the secondary forming, deformation of the coil 12 due to the forming pressure can be prevented. Also, since the coil 12 is a fusion wire 19,
The coil 12 can be solidified only by heating, and the workability is good. Further, by preventing deformation of the coil 12, it is possible to increase the molding pressure, and as a result, it is possible to reduce the number of gates 22F. Reducing the number of the gates 22F means that the shape of the female mold 22 is simplified to reduce the cost of the mold, and the molding is hardened in the gate 22F after molding and is wasted and discarded. Since it means that the amount of the material is reduced, the material cost can be reduced. Further, since the coil 12 to be solidified is solidified while being wound around the bobbin 10, the coil 12 can be reliably positioned in the secondary molding die 20. Further, since the terminal fitting 14 is formed on the bobbin 10 and the terminal fitting 14 is fixed thereto, the terminal fitting 14 can be reliably positioned in the secondary molding die 20.

Second Embodiment Next, a second embodiment of the present invention will be described with reference to FIG. In this embodiment,
The means for solidifying the coil has a configuration different from that of the first embodiment. Other configurations are the same as those in the first embodiment, and thus the same configurations are denoted by the same reference numerals, and description of the structures, operations, and effects will be omitted. The coil 25 of the second embodiment is formed by winding a commonly used copper wire 26 (a winding which is a constituent element of the present invention). As a resin 27 for solidifying the coil 25, for example, an epoxy resin or the like is used. A thermosetting resin or the like is used, and the resin 27 is applied only to a necessary portion (for example, a portion where the molding pressure becomes high) on the outer periphery of the coil 25 while being kept in a fluid state. Here, when a part of the coil 25 is shown in an enlarged cross section, before the resin 27 is applied, there is a slight gap between the adjacent copper wires 26 as shown in the lower side of FIG. I have. Therefore, the resin 27 applied to the outer periphery of the coil 25 impregnates the gap between the copper wires 26,
The state shown in the upper part of FIG. 5 is obtained. Thereafter, the hardening of the resin 27 is awaited by performing processing such as heating. When the resin 27 is cured, the copper wires 26 are integrated with each other by this curing force, and the coil 25 is solidified. In the present embodiment, the coil 25
Is applied to the outer periphery of the coil 25, for example, it is possible to partially solidify only the portion where the molding pressure is maximum. As a result, it is not necessary to solidify even the region that does not need to be solidified, and it is possible to reduce the material cost by suppressing the consumption of the resin 27 to the necessary minimum.

<Other Embodiments> The present invention is not limited to the embodiments described above and illustrated in the drawings. For example, the following embodiments are also included in the technical scope of the present invention. In addition, various changes can be made without departing from the scope of the invention. (1) In the above embodiment, the secondary molding is performed while the coil is wound around the bobbin. However, according to the present invention, only the coil may be set in the secondary molding die without using the bobbin. .

(2) In the above embodiment, the terminal mounting portion is provided on the bobbin and the terminal fitting is fixed thereto. However, according to the present invention, a bobbin having no terminal mounting portion can be used. (3) In the second embodiment, only the portion where the molding pressure of the coil is maximum is solidified. However, according to the present invention, the entire coil may be solidified in the second embodiment.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a molding process according to a first embodiment.

FIG. 2 is a cross-sectional view of the coil device according to the first embodiment.

FIG. 3 is a front view of a mold according to the first embodiment.

FIG. 4 is a partially enlarged view of a coil according to the first embodiment;
(A) shows a state before the coil is solidified, and (b) shows a state where the coil is solidified.

FIG. 5 is a partially enlarged cross-sectional view of a coil according to a second embodiment.

FIG. 6 is a sectional view of a conventional coil device.

FIG. 7 is a front view showing a conventional mold.

[Explanation of symbols]

 A: Coil device 10: Bobbin 12: Coil 13: Terminal mounting part 14: Terminal fitting 15: Lead wire 16: Protective layer part 19A: Conductor 19B: Thermosetting resin (resin) 20: Secondary mold 25 Coil 26: Copper wire (winding wire) 27: Resin

Claims (6)

[Claims] 1. A method of manufacturing a coil device, comprising setting a coil in a mold, injecting a molding material, and forming an insulating protective layer portion on the outer periphery of the coil, wherein the coil material is injected prior to the injection of the molding material. And a method of manufacturing a coil device, wherein the coil is solidified with a resin. 2. The method for manufacturing a coil device according to claim 1, wherein the coil is solidified while being wound around a bobbin, and the bobbin is positioned and set in the mold. 3. A structure in which a terminal mounting portion is provided on the bobbin, and a terminal fitting mounted on the terminal mounting portion and a lead wire extending from the coil are connected and set in the mold. 3. The method for manufacturing a coil device according to claim 2, wherein: 4. The coil is solidified with the resin only in a region where a molding pressure is maximum in a flow path of the molding material along the coil.
A method of manufacturing the coil device according to claim 3. 5. The method according to claim 1, wherein the coil is a fusion wire formed by covering a conductor with a thermosetting resin having adhesiveness, and the fusion wire is heated to solidify the coil. A method for manufacturing the coil device according to claim 1. 6. The coil according to claim 1, wherein the resin is applied to an outer periphery of the coil and is impregnated in a gap between windings of the coil to solidify the coil. Of manufacturing a coil device.