JPH10199741A - Method of assembling coil device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent noise of a coil device and simplify an assembling method of the coil device. SOLUTION: In this assembling method of a coil device, a preheated center leg 3 of one core A is inserted into a cavity 6 of a bobbin 5, and after applying a hot-melt 13 preheated up to the melting point to a contact face of the center leg 3 of the core A, a preheated center leg 3 of the other core B is inserted into the cavity 6 of the bobbin 5. After that, each outside leg of a pair of core A and B is fixed, the hot-melt 13 is cooled and hardened, thereby the center legs 3 of a pair of core A and B are tightly bonded and fixed, and the pair of core A and B fixed. This makes it possible to prevent buzz noise generally caused by the vibration generated from the air gap between the center legs 3 of the pair of core A and B. Moreover, as the air gap at the contact face of each center leg 3 of a pair of core A and B is filled with an insulating resin, a mica paper and a bakelite plate are not needed, and resultingly the assembly of the core device becomes simplified. Therefore, this makes it possible to prevent buzz noise and simplify the assembling method of the coil device.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for assembling a coil device such as a transformer, a reactor or a mag amplifier (magnetic amplifier).

[0002]

2. Description of the Related Art Conventionally, a coil device in which a pair of cores having at least one middle leg between a pair of outer legs is inserted into a bobbin on which a winding is wound is conventionally known as a transformer, a reactor or a mag amplifier (magnetic amplifier). Widely used for etc. Each core is formed by laminating about 20 to 40 silicon steel sheets punched out by pressing or the like into an E-shape or eye-shape, or magnetic material such as ferrite is integrally formed into an E-shape or eye-shape cross-section Is usually used. Further, the pair of cores are fixed by surrounding their outer peripheral surfaces with insulating tape or sheet metal, or by welding the joints of the pair of outer legs of each core.

[0003]

By the way, in a coil device used in a high frequency region such as a transformer or a high-frequency reactor used for a switching power supply or the like, the center legs of a pair of cores are adjusted in order to adjust the inductance. A gap may be provided at the joint. In this case, the pair of cores vibrate due to the high-frequency current flowing through the winding, and noise such as a growling noise is generated from the gap at the joint of the center leg of each core. In practice, the noise can be reduced to some extent by inserting an insulating material such as mica paper or a bake plate into the gap between the joints of the middle legs of the pair of cores. And the number of parts increases, and the assembling work becomes complicated.

Accordingly, an object of the present invention is to provide a method of assembling a coil device which is easy to assemble and can prevent noise such as a growling sound.

[0005]

According to a method of assembling a coil device according to the present invention, a pair of cores having at least one middle leg between a pair of outer legs is to be applied to a joining surface of the middle leg. A step of preheating to the melting point temperature of the adhesive consisting of: a cavity for inserting the middle leg of the pair of cores; a pair of flanges formed at both ends of the cavity; and a coil wound between the pair of flanges. Inserting the hollow portion of the bobbin having a winding into the center leg of one of the preheated cores, and preheating to the melting temperature of the joining surface of the middle leg of the one core in the hollow portion of the bobbin. Applying the adhesive, inserting the middle leg of the other preheated core into the hollow portion of the bobbin, and fixing a pair of outer legs of each of the one and the other core, Middle leg of each of the one and other cores And a step of cooling curing the adhesive between the bonding surfaces. In the illustrated embodiment, the pair of cores has a fitting means that can be fitted to the joint of each pair of outer legs, and the hollow portion of the bobbin in which the middle leg of the one core is inserted. After the center leg of the other core is inserted, the pair of cores is pressed to fit the respective fitting means to each other.

A bobbin cavity is inserted into the center leg of one of the cores which has been heated in advance, and an adhesive made of a thermoplastic resin preheated to the melting point temperature is joined to the joining surface of the center leg of the core in the bobbin cavity. After the agent is applied, the pre-heated middle leg of the other core is inserted into the hollow portion of the bobbin, so that the applied adhesive is applied between the joint surfaces of the pre-heated pair of cores. Spread evenly and evenly with each other. Then, by fixing the pair of outer legs of each of the one and the other cores, and cooling and hardening the adhesive between the joint surfaces of the respective middle legs of the one and the other cores, the respective middle legs of the pair of the cores are formed. It is firmly adhered and fixed, and a pair of cores is fixed.
Therefore, even when a high-frequency current flows through the winding, the pair of cores does not vibrate, and no growling noise is generated from the gap at the joint of the center leg of each core. Further, since the adhesive is cured, the gap between the joint surfaces of the respective middle legs of the pair of cores is filled with an insulating resin, so that an insulating material such as mica paper or a bake plate is inserted into the gap. There is no need, and the assembly work of the coil device is simplified. Therefore, it is possible to simplify the assembling work of the coil device and to prevent noise such as a growling noise. In the case where fitting means that can be fitted to each other are provided at the joints of the pair of outer legs of the pair of cores, these fitting means are fitted to each other to firmly fix the pair of cores. can do. Therefore, a fixing member for fixing the pair of cores and welding work are not required,
It is possible to further simplify the assembly operation of the coil device.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of a method of assembling a coil device according to the present invention will be described below with reference to FIGS. FIG. 1 shows a pair of cores A and B used in the present embodiment. That is, the pair of cores A and B shown in FIG. 1 are composed of both side extending portions 1b and both side extending portions 1b extending from both ends of the base 1a.
The two middle extension portions 1c extending from the base portion 1a between b are formed by stacking about 20 to 40 silicon steel sheets 1 each having a thickness of about 0.5 mm formed by press punching or the like. It is composed. The two extending portions 1b of the silicon steel plate 1 constitute a pair of outer legs 2 of a pair of cores A and B, and two middle extending portions 1b.
c constitutes two middle legs 3 of a pair of cores A and B. In the present embodiment, two middle legs 3 of one core A are provided in order to provide a gap at the joint between the middle legs 3 of the pair of cores A and B.
Is slightly shorter than the length of the pair of outer legs 2. A wedge-shaped projection 1d is formed at the tip of the both-side extending portion 1b of the silicon steel sheet 1 constituting one core A so as to project from the outside to the inside of the both-side extending portion 1b, respectively.
Wedge-shaped projections 1e are provided at both ends of the silicon steel plate 1 constituting the other core B at both ends thereof.
Is formed so as to protrude from the inside to the outside. The protrusions 1d and 1e constitute fitting protrusions 4a and 4b as fitting means that can be fitted to each other at the joints 2a and 2b of the outer legs 2 of the pair of cores A and B, respectively. Each of the silicon steel plates 1 constituting the pair of cores A and B is provided with a concave portion 1f for positioning and fixing when the silicon steel plates 1 are stacked by a press or the like. For this reason, by stacking several silicon steel plates 1 and caulking the recesses 1f, the stacked silicon steel plates 1 can be securely fixed without displacement. The bobbin 5 used in the present embodiment includes a hollow portion 6 for inserting the middle leg 3 of the core A (or B) as shown in FIG.
And two coil device bobbins 10 provided side by side with a pair of flanges 7 formed at both ends of the pair and a pair of terminal portions 9 formed at one end of each of the pair of flanges 7 and having a lead electrode 8. It is connected to. Although not shown for simplicity, at least one winding is wound between a pair of flanges 7 of the coil device bobbin 10 in advance, and both ends of the winding are wound around a pair of terminal portions 9. And is electrically connected to the lead electrode 8 by soldering or the like.

The method of assembling the coil device having the above configuration is as follows. First, as shown in FIG. 3, a pair of cores A and B each formed by laminating about 20 to 40 silicon steel sheets 1 shown in FIG. 1 are placed on a hot plate 12 provided with a heater 11, respectively. By hot plate 1
2 is heated to preheat the pair of cores A and B to about 60 to 100 ° C. Next, as shown in FIG. 4, the two middle legs 3 of one preheated core A are attached to the two bobbins 5 shown in FIG.
The two cavities 6 are inserted. Then, as shown in FIG.
One core A 2 in the two cavities 6 of the bobbin 5
A hot melt (trade name) 13 as an adhesive made of a thermoplastic resin (polyamide) preheated to 180 ° C. on the joint surface of the middle leg 3 of the book is applied by a hot melt applicator 14 to 0.4 to 0.7 g /. Apply at two locations. The application of the hot melt 13 is performed by sequentially moving the hot melt applicator 14 in the direction of the arrow and disposing the nozzle 14a of the hot melt applicator 14 on the cavity 6 of the bobbin 5,
This is performed by dropping a required amount of the liquid hot melt 13 from the nozzle 14a onto the joint surface of the two middle legs 3 of one core A. After applying the hot melt 13 to the joint surface of the two middle legs 3 of one core A, the two cores B of the other core B preheated to the two hollow portions 6 of the bobbin 5 as shown in FIG. The leg 3 is inserted, and the other core B is pressed against one core A on which the bobbin 5 is mounted with a force of about 150 kg. As a result, the pair of outer legs 2 of the one and the other cores A and B are elastically deformed outward and inward, respectively, so that the fitting protrusion 4a of the one core A and the fitting protrusion 4b of the other core B are formed. The outer legs 2 of the pair of cores A and B are firmly fixed by fitting each other. At the same time, one core A
Hot melt 13 applied to the joint surface of the two middle legs 3
As shown in FIG. 7, the pre-heated cores A and B spread uniformly and evenly between the joint surfaces of the middle legs 3 of the pair of cores A and B. The hot melt 13 can be filled without gaps. After fixing each of the outer legs 2 of the pair of cores A and B, about 1
The hot melt 13 between the joint surfaces of the middle legs 3 of the pair of cores A and B is cooled and hardened for about 5 seconds. As a result, the hot melt 13 is cured to form an insulating resin, and the middle legs 3 of the pair of cores A and B are firmly adhered and fixed, thereby completing the assembly of the coil device.

As described above, in the present embodiment, the middle legs 3 of the pair of cores A and B are firmly adhered and fixed by the hot melt 13 filled in the gap without any gap. When the air flows, the pair of cores A and B do not vibrate, and no growling noise is generated from the gap at the joint of the middle legs 3 of the cores A and B. Further, as the hot melt 13 in the gap is hardened, the gap between the joining surfaces of the middle legs 3 of the pair of cores A and B is filled with an insulating resin. There is no need to insert an insulating material such as mica paper or a bake plate, and the assembling work of the coil device is simplified. Therefore, it is possible to simplify the assembling work of the coil device and to prevent noise such as a growling noise. Furthermore,
Fitting projection 4a at joint 2a of outer leg 2 of one core A
And the fitting protrusion 4b of the joint 2b of the outer leg 2 of the other core B are fitted to each other, so that a pair of cores A and
Since each outer leg 2 of B is firmly fixed, a pair of cores A,
Fixing members such as insulating tape or sheet metal for fixing B and welding work are not required, and the assembling work of the coil device is further simplified.

The embodiment of the present invention is not limited to the above embodiment, and various modifications are possible. For example, in the above-described embodiment, a pair of cores A and B are formed by stacking about 20 to 40 pieces of silicon steel sheets 1 each having the both-side extending portions 1b and the two middle-side extending portions 1c formed thereon. Although the embodiment has been described, a pair of cores A and B may be formed by integrally molding a magnetic material such as ferrite into the same cross-sectional shape as the shape of the silicon steel sheet 1. In the above embodiment, the fitting protrusion 4a at the joint 2a of the outer leg 2 of one core A and the outer leg 2 of the other core B
Although the outer leg 2 of each of the cores A and B is fixed by fitting the fitting projections 4b of the joints 2b with each other, the pair of fittings 4a and 4b is not provided as in the related art. Of the cores A, B is surrounded by insulating tape or sheet metal or the like, or the joints 2a, 2b of the pair of outer legs 2 of the cores A, B are welded to the outside of the cores A, B. Of course, it is also possible to fix the leg 2. Further, in the above-described embodiment, a case is shown in which wedge-shaped fitting protrusions 4a and 4b having the same shape are provided as fitting means at the joining portions 2a and 2b of the outer legs 2 of the pair of cores A and B, respectively. One of the joints 2a and 2b of the outer legs 2 of the pair of cores A and B may be provided with a protrusion, and the other may be provided with a notch that can be fitted with the protrusion. Furthermore, in the above-described embodiment, a so-called outer iron-type is provided in which a bobbin 5 in which two bobbins 10 for coil devices in which windings are wound around two middle legs 3 of a pair of cores A and B are connected side by side. Although the case of the coil device has been described, a so-called inner iron type coil device in which a bobbin for a coil device in which a winding is wound around each of a pair of outer legs of a pair of E-shaped cores such as a mag amplifier is attached. The present invention can be applied to the case.

[0011]

According to the present invention, each middle leg of a pair of cores is firmly adhered to by an adhesive filled in the gap without any gap.
Since it is fixed, even a coil device used in a high frequency region can prevent noise such as a growling noise due to the vibration of the pair of cores. In addition, since the adhesive filled in the gap without any gap is hardened, an insulating resin is formed between the joint surfaces of the middle legs of the pair of cores, so that an insulating material such as a mica paper or a bake plate is formed. Need not be inserted into the gap, and the assembly operation of the coil device is simplified. Therefore,
It is possible to obtain a coil device that is easy to assemble and quiet even in a high frequency range. Furthermore, since the pair of outer legs of each core is firmly fixed by fitting the fitting means provided at the joint portion of each outer leg of the pair of cores to each other, the fixing means for fixing the pair of cores is provided. A fixing member such as an insulating tape or a sheet metal or a welding operation is not required, and the assembling operation of the coil device can be further simplified.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a pair of cores used in an embodiment of the present invention.

FIG. 2 is a perspective view showing a bobbin used in an embodiment of the present invention.

FIG. 3 is a front sectional view showing a step of preheating a pair of cores.

FIG. 4 is a perspective view showing a step of inserting a bobbin into one core.

FIG. 5 is a front sectional view showing a step of applying a hot melt to a joint surface of a middle leg of one core;

FIG. 6 is a perspective view showing a step of inserting another core into a bobbin on which one core is inserted.

FIG. 7 is a front sectional view showing the coil device that has been assembled.

[Explanation of symbols]

1. . . Silicon steel sheet, 1a. . . Base, 1b. . . Extension on both sides, 1c. . . Middle extension, 1d, 1e. . . Protrusion, 1
f. . . Recess, 2. . . Outer legs, 2a, 2b. . . Joints,
3. . . , Middle leg, 4a, 4b. . . 4. fitting projection (fitting means); . . Bobbins, 6. . . 6. cavity, . . Flange, 8. . . 8. lead electrode; . . Terminal part, 1
0. . . 10. bobbin for coil device; . . Heater, 1
2. . . Hot plate, 13. . . 13. hot melt (adhesive); . . Hot melt applicator, 14
a. . . Nozzle, A. . . One core, B.I. . . The other core

Claims (2)

[Claims] 1. A step of preheating a pair of cores having at least one middle leg between a pair of outer legs to a melting point temperature of an adhesive made of a thermoplastic resin to be applied to a joint surface of the middle leg. The hollow portion of the bobbin having a hollow portion into which the center leg of the pair of cores is inserted, a pair of flanges formed at both ends of the hollow portion, and a winding wound between the pair of flanges is preheated. Inserting the adhesive pre-heated to the melting point to the joining surface of the middle leg of the one core in the hollow portion of the bobbin; Inserting the middle leg of the other core pre-heated to the outside; fixing the pair of outer legs of each of the one and other cores; and joining surfaces of the middle legs of the one and the other cores. Cooling and curing the adhesive between Method of assembling a coil apparatus which comprises a. 2. The pair of cores have fitting means that can be fitted to each other at a joint of the pair of outer legs, and the pair of cores is provided in a hollow portion of the bobbin in which the middle leg of the one core is inserted. The method for assembling a coil device according to claim 1, further comprising a step of pressing the pair of cores to fit the respective fitting means to each other after inserting the middle leg of the other core.