JP2003124020A - Electromagnetic coil, its manufacturing method, and coil bobbin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electromagnetic coil that can be used for a long period in an electric motor, solenoid-controlled valve, electromagnetic actuator, etc. SOLUTION: This electromagnetic coil is composed of a coil bobbin 3, a coil 4, and a coil case 5. The coil 4 is sealed with a molding resin. Recessed sections 22a, 22b, 22c, 22d, etc., up to the outer peripheral surfaces 25a, 26a, etc., of a core 20 are formed on the internal side faces of the flanges 21a and 21b of the coil bobbin 2. In addition, the molding resin 6 which seals the periphery of the winding 4 is packed in the internal space between the flanges 21a and 21b of the bobbin 2 and the coil case 5, recessed sections 22a, 22b, 22c, 22d, etc., of the flanges 21a and 21b, and the space (not shown in the Fig.) formed between the outer peripheral surfaces 25a, 26a, etc., of the core 20 and the coil 4 through vacuum defoaming treatment using the casting method.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention particularly relates to an electromagnetic coil used in an electric motor, an electromagnetic control valve, an electromagnetic actuator, etc., a method of manufacturing the same, and a coil bobbin.

[0002]

2. Description of the Related Art A conventional electromagnetic coil 1 has a hollow, substantially rectangular core as shown in FIG. 7 which is a vertical sectional view of the electromagnetic coil and FIG. 8 which is a vertical sectional view in a plane orthogonal to FIG. Two
Coil bobbin 2 having a pair of parallel flanges 21a, 21b facing each other at both ends of winding core 20
And a winding 4 made of a copper wire wound around the winding core 20 of the coil bobbin 2 and a pair of flanges 21a, 2 of the coil bobbin 2.
A coil case 5 fitted between the coil bobbin 1b and the coil bobbin 2 is wound around the winding core 20 of the coil bobbin 2.

However, in the conventional electromagnetic coil 1, when the winding 4 is wound around the outer periphery of the winding core 20 of the coil bobbin 2, the winding 4 does not come into close contact with the entire outer peripheral surface of the winding core 20 of the coil bobbin 2, and 7 and FIG. 8, a small space 24a is provided between the outer peripheral surface of the winding core 20 of the coil bobbin 2 and the winding 4.
24b, 24c, and 24d are formed.

The electromagnetic coil 1 having such spaces 24a to 24d formed therein has spaces 24a, 24b, 24c and 24d between the winding 4 and the outer peripheral surface of the winding core 20 of the coil bobbin 2.
When the winding 4 is energized, the air expands due to heat generation, and stops energizing and contracts after a while.

When the electromagnetic coil 1 is used for a long time, the windings 4 of the electromagnetic coil 1 may rub against each other due to repeated expansion and contraction of air in the spaces 24a to 24d. There was a risk of causing.

[0006]

In view of the above point, the first object of the present invention is to expand or contract the air in the space between the outer peripheral surface of the winding core of the coil bobbin and the winding due to heat generation of the winding. An object of the present invention is to provide an electromagnetic coil which does not repeat and the windings of the electromagnetic coil do not rub against each other even if the electromagnetic coil is used for a long period of time, and thus there is no possibility of causing a short circuit or a rare short circuit.

A second object of the present invention is to provide a method of manufacturing an electromagnetic coil capable of eliminating the air in the space formed between the outer circumference of the winding core of the coil bobbin and the winding.

A third object of the present invention is to provide a coil bobbin having an optimum shape for an electromagnetic coil.

[0009]

In order to achieve the above object, the present invention forms a plurality of recesses on the inner side surface of a flange of a coil bobbin, the recesses reaching the outer surface of the winding core, and these recesses form the winding core of the coil bobbin. The space formed between the outer circumference of the coil core of the coil bobbin and the winding is formed within the flange of the coil bobbin by providing an air vent passage for extracting air from the space formed between the outer circumference of the coil bobbin and the winding. Mold resin that is connected to the air vent passage formed on the side surface, and when the molding resin is injected, the air in the space escapes to the outside through the air vent passage on the inner surface of the flange of the coil bobbin and seals the periphery of the winding. Is injected into the space between the outer circumference of the winding core of the coil bobbin and the winding through the air vent passage of the flange of the coil bobbin.

In order to solve the above problems, an electromagnetic coil of the present invention has a hollow substantially rectangular core, and a coil bobbin in which a pair of parallel flanges are formed at opposite ends of the core, and which are parallel to each other. In an electromagnetic coil consisting of a winding wound around the core of the coil bobbin and a coil case fitted between a pair of flanges of the coil bobbin, the winding is wound around the outer circumference of the core of the coil bobbin and A plurality of air vent passages are formed on the side surface to reach the outer surface of the winding core, and are formed in the internal space between the coil bobbin flange and the coil case, the air vent passage of the coil bobbin flange, and the space between the outer circumference of the winding core and the winding. It was provided by filling a mold resin that seals around the winding.

In the electromagnetic coil of the present invention, the air vent passages are formed on both inner surfaces of the pair of flanges of the coil bobbin facing each other.

In the electromagnetic coil of the present invention, the air vent passage is formed corresponding to each surface of the winding core on the inner surface of the flange of the coil bobbin.

In order to solve the above problems, the method of manufacturing an electromagnetic coil according to the present invention is such that a winding is wound around a winding core of a coil bobbin having a plurality of recesses on the inner surface side of the flange portion that reach the outer surface of the winding core. As a formwork that fits a coil case between a pair of flanges of a coil bobbin to form an internal space surrounding a winding, and after injecting mold resin into the internal space of the formwork consisting of the coil bobbin flange and the coil case, The mold resin was heated and evacuated.

In order to solve the above-mentioned problems, a coil bobbin according to the present invention has a hollow substantially rectangular core, and a pair of parallel flanges facing each other is formed at both ends of the core. A plurality of recesses was formed on the inner surface to reach the outer surface of the winding core.

[0015]

DETAILED DESCRIPTION OF THE INVENTION The structure of an electromagnetic coil according to the present invention will be described below with reference to FIGS. FIG. 1 is an exploded perspective view for explaining the outline of the configuration of a coil bobbin forming an electromagnetic coil according to an embodiment of the present invention, FIG. 2 is an external perspective view of an electromagnetic coil according to an embodiment of the present invention, and FIG. FIG. 1 for explaining the structure of the electromagnetic coil of the invention.
3 is an enlarged cross-sectional view of a main part in the section of FIG. 3, and FIG. 4 is a diagram illustrating the structure of the electromagnetic coil of the present invention Fi of FIG. 1 and FIG.
FIG. 5 is a vertical cross-sectional view taken along the g4-Fig4 cross section, and FIG. 5 illustrates the structure of the electromagnetic coil of the present invention.
6 is a vertical cross-sectional view seen from the left in FIG.
1 and 2 for explaining the structure of the electromagnetic coil of the present invention.
FIG. 6 is a vertical cross-sectional view seen from the right in the FIG.

As shown in FIGS. 1 and 2, the electromagnetic coil 1 of the present invention has a pair of parallel flanges 21a, 2 facing each other at both ends of a hollow core 20 having a substantially rectangular tubular shape.
1b, a coil bobbin 2 formed of a copper wire wound around a winding core 20 of the coil bobbin 2, and a coil case 5 fitted between a pair of flanges 21a and 21b of the coil bobbin 2. .

As shown in FIGS. 1 to 6, the coil bobbin 2
Has a winding core 20 having a tubular shape with a substantially rectangular cross section, and horizontal walls 25a and 25b parallel to each other are provided above and below the winding core 20, respectively.
Vertical walls 26a and 26b parallel to each other are provided on the left and right. The four corners of each wall are rounded. A core insertion portion 27 for inserting a core (not shown) is formed inside the winding core 20 of the coil bobbin 2.

On the surface of the horizontal wall 25a located on the upper side of the winding core 20 on the side of the core insertion portion 27, two parallel ridges 28, 28 projecting downward along the longitudinal direction are formed.
On the surface of the horizontal wall 25b located on the lower side of 0 on the core insertion portion 27 side, two parallel engaging projections 29, 29 projecting obliquely upward along the longitudinal direction are formed.

The flanges 21a, 21 of the coil bobbin 20
On the inner side surface of b, eight recessed concave portions 22a to 22 which serve as a plurality of air vent passages reaching the four outer surfaces of the winding core 20.
h is formed.

That is, as shown in FIG. 5, the flange 2
1a includes horizontal walls 25a and 25b of the winding core 20 and a vertical wall 2
Recesses 22a, 22c, 22e, 22g reaching the surfaces of 6a, 26b, that is, the outer surface of the winding core 20, are formed so as to reach the outer peripheral edge of the flange 21a, respectively.

Similarly, as shown in FIG. 6, the flange 21
In b, recesses 22b, 22 reaching the outer surface of the core 20 are provided.
d, 22f and 22h are formed so as to reach the outer peripheral edge of the flange 21b.

The coil bobbin 2 is made of a synthetic resin material such as polybutylene terephthalate (PBT).
It is formed by injection molding.

The coil bobbin 2 is formed by injecting a synthetic resin into the cavity of the mold. In order to smoothly open the mold after molding the coil bobbin 2, the coil bobbin 2
And the recesses 22a and 22c on the inner surface of the flange 21a of
2e and 22g are formed along the mold opening direction of the mold, and recesses 22b and 22d are formed on the inner surface of the flange 21b.
22f and 22h are formed along the mold opening direction.

A space 24a is provided between the winding 4 wound around the outer circumference of the winding core 20 of the coil bobbin 2 and the outer circumference of the winding core 20.
24d is formed.

Recesses 22a to 22g of the flange 21a and recesses 22b to 22h of the flange 21b are connected to both ends of the spaces 24a to 24d, respectively. That is,
The space 24a is formed by the recesses 22a and 22b, and the space 24b is formed by the recesses 22e. 22F, the space 24c becomes a recess 22c,
The space 24d is communicated to the outside by the recess 22g and 22h.

As shown in FIGS. 1 and 2, a thick-walled reinforcing boss 30 projecting outward is integrally formed on the outer surface near the middle between the upper edge and the lower edge of the flange 21a. ,
Two through holes are provided in the reinforcing boss 30 of the flange 21a of the coil bobbin 2. The lead wire 41a and the lead wire 41b are provided at one end and the other end of the winding wire 4 wound around the outer circumference of the winding core 20 of the coil bobbin 2 of the electromagnetic coil 1.
Are connected to each other and are drawn out to the outside from a through hole provided in the reinforcing boss 30.

The flanges 21a and 21b of the coil bobbin 2
Mold resin 6 is injected into the internal space 23 formed by the coil case 5 and the coil case 5 to seal the periphery of the winding 4. Mold resin 6 is filled by injection into the recesses 22a to 22h formed in the flanges 21a and 21b of the coil bobbin 2 and the spaces 24a to 24d formed between the outer circumference of the winding core 20 and the winding wire 4.

As shown in FIGS. 1, 5, and 6, the coil case 5 of the electromagnetic coil 1 has an end wall 50 that closes between the upper edge of the flange 21a and the upper edge of the flange 21b.
And a pair of parallel side walls 5 that face each other and close between both side edges of the flange 21a and both sides of the flange 21b.
It has 1,51.

The coil case 5 of the electromagnetic coil 1 is formed of a synthetic resin material such as polybutylene terephthalate (PBT) by injection molding.

A coil case 5 is fitted between a pair of flanges 21a and 21b of the coil bobbin 2 around which the coil 4 is wound, and a mold 7 for injecting the molding resin 6 from the coil bobbin 2 and the coil case 5 is formed. Is formed, formwork 7
Is opened downward.

A method of manufacturing the electromagnetic coil 1 using such a coil bobbin 2 will be described below.

First, the winding wire 4 is wound around the outer circumference of the winding core 20 of the coil bobbin 2, and the lead wires 41a inserted into the through holes formed in the reinforcing boss 30 of the flange 21a at both ends of the winding wire 4,
41b is connected by, for example, soldering, and then the coil case 5 is inserted between the flanges 21a and 21b of the coil bobbin 2.
7 for fitting the inner wall 23 to form the inner space 23 surrounding the winding 4.
And

Next, the opening of the mold 7 is directed upward, and the flanges 21a and 21b of the coil bobbin 2 and the coil case 5 are arranged.
In the internal space 23 of the mold 7 made of, for example, epoxy (E
P) After the mold resin 6 made of a synthetic resin material such as a resin is cast, the mold resin 6 is heated and evacuated, that is, a vacuum defoaming process is performed by a so-called casting method.

By this process, the air in the space 23 is removed, the resin is filled and hardened to seal the periphery of the winding 4, and the air in the spaces 24a to 24d functions as an air vent passage. The gas is discharged through the recesses 22a to 22h, and the spaces 24a to 24d and the recesses 2 are discharged.
Mold resin 6 is filled in 2a to 22h.

In this way, the flanges 21a, 21b
And an inner space 23 formed by the coil case 5, the spaces 24a to 24d, and the recesses 22a to 22.
The electromagnetic coil 1 is manufactured by filling h with the mold resin 6 that seals around the winding 4.

Next, the operation of the embodiment of the present invention will be described. The lead wires 41a, 4 are attached to the winding 4 of the electromagnetic coil 1.
When energized via 1b, a magnetic field is generated around the winding 4 of the electromagnetic coil 1. Since the spaces 24a to 24d are filled with the mold resin 6 that seals the periphery of the winding wire 4, even if the winding wire 4 of the electromagnetic coil 1 generates heat, the space between the outer circumference of the winding core 20 and the winding wire 4 is reduced. Since there is no air in the spaces 24a to 24d, there is no possibility that the windings 4 rub against each other due to the expansion and contraction of air, and it is possible to reliably prevent short-circuiting or rare short-circuiting of the windings 4.

[0037]

As described above, according to the electromagnetic coil of the present invention, by forming a plurality of air vent passages on the inner surface of the flange of the coil bobbin to reach the outer surface of the core, the coil core of the coil bobbin is formed. The space between the outer circumference of the coil and the winding is communicated with the air vent passage on the inner surface of the flange of the coil bobbin, and the molding resin that seals the periphery of the coil is wound on the coil bobbin via the air vent passage on the flange of the coil bobbin. The space between the outer circumference of the core and the winding can be filled, and the mold resin enters the space between the outer circumference of the winding core of the coil bobbin and the winding. The air in the space can be discharged to the outside through the air vent passage on the inner surface of the flange of the coil bobbin, and even if the winding of the electromagnetic coil heats up when the winding of the electromagnetic coil is energized, The air in the space between the outer peripheral surface of the winding core of the coil bobbin and the winding will no longer expand due to the heat generated by the winding, and even if the electromagnetic coil is used for a long time, When they rub against each other, there is no possibility of causing a short circuit or a rare short circuit.

According to the electromagnetic coil of the present invention, since the air vent passages are formed on both inner surfaces of the pair of flanges of the coil bobbin facing each other, the air vent passage between the outer circumference of the winding core of the coil bobbin and the winding wire is formed. Since the air in the space smoothly escapes through the air vent passages on the inner surfaces of the pair of flanges of the coil bobbin, the air does not remain in the space between the outer periphery of the winding core of the coil bobbin and the winding.

According to the electromagnetic coil of the present invention, since the air vent passage is formed corresponding to each surface of the core on the inner surface of the flange, the air vent passage of the flange of the coil bobbin is provided on the outer circumference of the core of the coil bobbin. And the space between the windings can be connected.

According to the method for manufacturing an electromagnetic coil of the present invention,
After the mold resin is cast into the inner space of the frame consisting of the coil bobbin flange and the coil case, the mold resin is heated and evacuated, and the circumference of the winding wound around the coil bobbin core is surrounded by the mold resin. At the same time as sealing with, the air in the space between the outer circumference of the coil bobbin core and the winding can be extracted through the air vent passage, and this space can be filled with mold resin. Since the air in the space between the windings is eliminated by the molding resin, it is possible to prevent the occurrence of short circuits and rare shorts due to the expansion and contraction of the air in the windings of the electromagnetic coil, and the electromagnetic coil can be used for a long time. .

According to the coil bobbin of the present invention, it is possible to provide an optimum coil bobbin for constructing an electromagnetic coil only by forming a plurality of recesses on the inner surface of the pair of flanges to reach the outer surface of the winding core.

[Brief description of drawings]

FIG. 1 is a perspective view illustrating a shape of a coil bobbin of an electromagnetic coil according to an embodiment of the present invention.

FIG. 2 is a perspective view illustrating an external shape of an electromagnetic coil according to the embodiment of the present invention.

FIG. 3 is an enlarged cross-sectional view taken along line FIG3-Fig3 of FIG. 1 for explaining the configuration of the main part of the electromagnetic coil of the present invention.

FIG. 4 is a cross-sectional view taken along line FIG4-Fig4 of FIGS. 1 and 2 for explaining a configuration of a main part of an electromagnetic coil of the present invention.

FIG. 5 illustrates the configuration of the electromagnetic coil of the present invention,
FIG. 3 is a sectional view taken along the line FIG5--FIG5 in FIG.

FIG. 6 is a view for explaining the configuration of an electromagnetic coil of the present invention,
FIG. 3 is a cross-sectional view taken along line FIG6--FIG6 of FIG.

FIG. 7 is a sectional view illustrating the structure of a conventional electromagnetic coil.

FIG. 8 is a sectional view taken along a plane orthogonal to FIG.

[Explanation of symbols] 1 electromagnetic coil 2 coil bobbins 20 winding core 21a, 21b flange 22a-22h recess 23 Internal space 24a-24d space 25a, 25b horizontal wall 26a, 26b Vertical wall 27 Core insertion part 28 convex stripes 29 Engaging protrusion 30 Reinforcing boss 4 windings 41a, 41b Lead wire 5 coil case 50 end wall 51 side wall 6 Mold resin 7 Formwork

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Tadashi Kabayama             Setagaya-ku, Tokyo Todoroki 7-1724 shares             Ceremony company Fuji Kouki F term (reference) 3H106 DA23 DB02 DB12 GA10 GB03                       JJ02                 5E044 AD06 BA01 BB02 BB06 BB08                       BC02 CA03 CA04 CA05                 5E048 AB01 CB01 CB05

Claims (5)

[Claims] 1. A coil bobbin having a hollow, substantially rectangular core and a pair of parallel flanges formed on opposite ends of the core, the coil bobbin wound around the core of the coil bobbin.
In an electromagnetic coil consisting of a coil case fitted between a pair of flanges of a coil bobbin, a plurality of windings are wound around the outer circumference of the core of the coil bobbin and reach the outer surface of the core on the inner surface of the flange of the coil bobbin. A mold resin that forms an air vent passage and seals the winding periphery in the internal space between the coil bobbin flange and the coil case, the air vent passage of the coil bobbin flange, and the space between the outer circumference of the winding core and the winding. An electromagnetic coil characterized by being provided by filling. 2. The electromagnetic coil according to claim 1, wherein the air vent passages are formed on both inner surfaces of a pair of flanges of the coil bobbin facing each other. 3. The electromagnetic coil according to claim 1, wherein the air vent passage is formed corresponding to each surface of the winding core on the inner surface of the flange of the coil bobbin. 4. A winding is wound around a winding core of a coil bobbin having a plurality of recesses reaching the outer surface of the winding core on the inner surface side of the flange portion, and a coil case is fitted between a pair of flanges of the coil bobbin. As a formwork that forms an internal space surrounding the winding,
A method for manufacturing an electromagnetic coil, which comprises injecting a mold resin into an inner space of a mold frame including a flange of a coil bobbin and a coil case, and then heating and vacuuming the mold resin. 5. A plurality of hollow cores each having a substantially rectangular shape, wherein a pair of parallel flanges facing each other are formed at both ends of the core, and a plurality of inner flanges reach the outer surface of the core. A coil bobbin having a recess.