JPH0538826U - Fixed coil - Google Patents

Abstract

(57) [Summary] [Object] An object of the present invention is to provide a fixed coil which can be configured in a small size, has a small leakage magnetic flux, and is hard to cause magnetic saturation. [Structure] A base 11, a pot core 13 having a central core portion 13a made of a magnetic material fixedly held on the base by an adhesive 12, and a central core inside the pot core. An air-core coil 14 mounted so as to surround the portion, and after penetrating the lead terminals 14a and 14b of the air-core coil into the base, the adhesive is cured to form a pot-shaped core. The fixed coil 10 is configured to be fixed to the table.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a fixed coil which generates a relatively large electromagnetic field by a large current.

[0002]

[Prior Art]

 Conventionally, such a fixed coil is configured as shown in FIG. 6, for example. That is, in FIG. 6, the fixed coil 1 is such that a drum-shaped core 3 is mounted on a base 2, a coil winding 4 is wound around the core 3, and a lead wire of the coil winding 4 is provided. It is configured by connecting the end to the electrode portion 5 provided on the bottom surface of the base 2.

A fixed coil having a structure as shown in FIG. 7 is also used. That is, in FIG. 7, the fixed coil 6 is configured by winding the coil winding 8 around the ring-shaped core 7.

According to the fixed coils 1 and 6 configured as described above, a magnetic flux is generated in any of the fixed coils 1 and 6 by applying a large current to the coil windings 4 and 8. Therefore, a relatively large magnetic field can be obtained.

[0005]

[Problems to be solved by the device]

 However, among the conventional fixed coils 1 and 6 configured as described above, the fixed coil 1 shown in FIG. 6 is an open magnetic circuit type, and therefore the magnetic flux leaking to the outside is relatively large. However, there is a problem in that it must be used while considering the electromagnetic effect on the surroundings.

Further, in the fixed coil 6 shown in FIG. 7, since it is a closed magnetic circuit type, the magnetic flux is relatively small, but since a ring-shaped core is used, magnetic saturation occurs. Since it is easy to do so, the core itself has to be formed thick and there is a problem that the overall structure becomes large.

In view of the above points, the present invention has an object to provide a fixed coil which can be configured in a small size, has a small leakage magnetic flux, and is hard to cause magnetic saturation.

[0008]

[Means for Solving the Problems]

 According to the present invention, the above-described object is to fix and hold the base and the base by punching out a sheet-like adhesive or by using an adhesive provided by printing, coating, or the like. A core-shaped core having a central core made of a magnetic material, and an air-core coil mounted so as to surround the central core in the pot-shaped core. This is achieved by a fixed coil, characterized in that after the lead terminal is penetrated into the base, the adhesive is cured to fix the pot core to the base.

In the fixed coil, preferably, the adhesive contains a magnetic material, and more preferably, a conductor is disposed below and below the adhesive.

[0010]

[Action]

 According to the above configuration, by energizing the air-core coil, the central core portion of the pot-shaped core passes through the upper surface of the pot-shaped core, the outer peripheral surface of the pot-shaped core, and further the pot-shaped core. A substantially closed magnetic path is formed, which projects outward from the lower end of the core and enters from the lower end of the central core portion of the pot-shaped core again.

Therefore, since the leakage magnetic flux is small and the magnetic saturation is unlikely to occur due to its shape, it can be made compact, and the adhesive can be punched from the sheet-shaped adhesive to Alternatively, since it is provided by printing, coating, etc., it can be easily arranged, and therefore can be easily constructed, so that the manufacturing cost can be reduced.

Further, when the adhesive contains a magnetic material, it passes through the adhesive from the lower end of the outer peripheral portion of the pot-shaped core and enters the lower end of the central core portion of the pot-shaped core. Therefore, a completely closed magnetic path will be formed, and if a conductor is provided below the adhesive, the leakage magnetic flux can be further reduced.

[0013]

【Example】

 Hereinafter, the present invention will be described in detail with reference to the embodiments shown in the drawings. FIG. 1 shows an embodiment of a fixed coil according to the present invention. In FIG. 1, a fixed coil 10 is mounted in a base 11, a pot core 13 made of a magnetic material fixedly held on the base 11 via an adhesive 12, and the pot core 13. It is composed of an air-core coil 14.

Since the periphery of the base 11 projects upward, the lower end portion of the pot-shaped core 13 can be clamped and held by the protruding portion, and the corner portion of the outer peripheral surface of the base 11 can be held. However, the chamfering at two locations makes it possible to easily determine the start and end of winding of the internal coil.

Further, the base 11 is provided with two terminal plates 11 a and 11 b, which serve as terminal electrodes corresponding to the lead terminals of the air-core coil 14, respectively, at end portions of the bottom surface facing each other. At the same time, it has two independent lead holes 11c and 11d penetrating vertically so that the lead terminals 14a and 14b do not contact each other.

The terminal plates 11 a and 11 b are attached to the base 11 so that they do not drop off from the base 11 and are partially embedded in the base 11 by, for example, integral molding or punching. It may be integrally formed, and as shown in FIGS. 2 and 3, the outer end portion thereof projects outward from the side edge of the bottom surface of the base 11. This facilitates soldering of the terminal boards 11a and 11b to the printed circuit board when mounting on the printed circuit board, and the soldering confirmation can be easily visually confirmed.

Further, the inner ends of the terminal plates 11a and 11b extend up to the vicinity of the lead holes 11c and 11d, and are directed upward so as to cover the side edges of the lead holes 11c and 11d. Is curved. As a result, the lead terminals 14a, 14b of the air-core coil 14 led out through the lead holes 11c, 11d are in contact with the terminal plates 11a, 11b at an acute angle so as not to be disconnected.

As shown in FIG. 3, the terminal plates 11a and 11b are bent upward in the vicinity of the center as seen from the side so as to bite into the base 11, and the curved portions are bent. The lead terminals 14a and 14b led out through the lead holes 11c and 11d are connected by soldering, welding, or the like.

The pot-shaped core 13 is formed of, for example, soft ferrite, a metal magnetic material, or a resin in which these are mixed into a hollow cylindrical shape having an open lower portion, and a central core projecting from above into a center thereof. It is provided with a part 13a. The lower end of the central core portion 13a is formed to be flush with the lower end surface of the outer peripheral portion or slightly shorter than the lower end surface of the outer peripheral portion. , Or not adhered at all.

Therefore, the pot core 13 can be adhered and fixed to the surface of the base 11 mainly by the bottom surface of the outer peripheral portion. As a result, the central core portion 13a is integrated with the outer peripheral portion of the pot core 13, and when an external force is applied to the pot core 13, the central core portion 13a is However, it does not move inside the pot-shaped core 13, the air core coil 14 abuts against the inner wall of the pot-shaped core 13 and is not damaged, and the central core portion 13a itself is not broken.

The air-core coil 14 is formed in advance by winding with an insulated enamel wire or the like, and then inserted into the inner space of the pot-shaped core 13, and the lead terminals 14 a and 14 b are The insulating film may be removed and the terminals 11a and 11b may be easily connected to each other by plating such as solder plating or flattening.

As shown in FIG. 4, the adhesive 12 is formed, for example, by punching a sheet-shaped adhesive so as to avoid the lead holes 11 c and 11 d of the base 11, and the pot type When the core 13 is bonded to the surface of the base 11, the adhesive 12 is melted by heat and compression.

The adhesive 12 may be provided on the lower surface of the pot-shaped core 13 or the surface of the base 11 by printing, coating, or the like, instead of the sheet-like adhesive. it is obvious.

The fixed coil 10 according to the present invention is constructed as described above, and the air-core coil 14 is first mounted in the vase-shaped core 13. At this time, the air-core coil 14 is fixed to the inner wall of the pot core 13 at least partially by an adhesive or the like in order to prevent vibration during operation in the pot core 13. Good. After that, while inserting the lead terminals 14a and 14b of the air-core coil 14 into the lead holes 11c and 11d of the base 11, the adhesive 12 is sandwiched and the pot core 13 is brought into contact with the surface of the base 11. . As a result, the pot-shaped core 13 is temporarily fixed to the base 11.

From this state, the lead terminals 14a and 14b protruding to the bottom surface of the base 11 are bent along the surfaces of the terminal boards 11a and 11b through the lead holes 11c and 11d of the base 11. At the same time, the terminal plates 11a and 11b are connected to each other at their curved portions by welding, soldering or the like.

At this time, since the above-mentioned curved portion is retracted above the bottom surface of the base 11, the lead terminals 14a and 14b can be easily welded or soldered, and the welded portion or soldered The portion does not project downward from the bottom surface of the base 11, and therefore, when the main fixed coil 10 is mounted on a printed circuit board or the like, the bottom surface of the base 11 does not correspond to the printed board. The entire surface comes into contact with the surface of the substrate 11, so that it can be mounted reliably and easily.

After connecting the lead terminals 14a and 14b to the terminal boards 11a and 11b in this way, the adhesive 12 is melted by further performing heat compression processing, thereby melting the pot core 13 and the base. The platforms 11 will be able to be fixed to each other. At that time, since the pot-shaped core 13 and the base 11 are brought closer to each other, the lead terminals 14a and 14b of the air-core coil 14 are slightly slackened, and when the main fixed coil 10 is used. Therefore, deterioration of the lead terminals 14a and 14b due to expansion and contraction due to heat or the like can be prevented.

Further, when the melted adhesive 12 flows into the lead holes 11c and 11d of the base 11, the lead holes 11c and 11d are closed by the melted adhesive 12, and therefore, The inner air-core coil 14 can be protected.

The fixed coil 10 thus assembled is also referred to as an intermediate type between the conventional open coil type fixed coil 1 shown in FIG. 6 and the closed magnetic circuit type fixed coil 6 shown in FIG. Since the leakage flux is about one tenth to one thousandth as compared with the fixed coil 1 in FIG. 6, it is not necessary to consider the electromagnetic effect on the surroundings. As compared with the fixed coil 6 shown in FIG. 7, magnetic saturation is less likely to occur, so that it can be constructed in a relatively small size.

Here, the adhesive 12 can be made a further closed magnetic circuit by using a magnetic film, a magnetic rubber or the like as the core, or by mixing a magnetic powder into the adhesive to make it magnetic. In addition, the leakage magnetic flux can be further reduced by disposing the sheet-shaped or adhesive-made conductor 15 below the adhesive 12 as a so-called short ring.

In the above embodiment, the inner end portions of the terminal plates 11a and 11b are formed so as to surround the side edges of the lead holes 11c and 11d of the base 11, but as shown in FIG. May end before the side edges of the lead holes 11c and 11d, and in that case, the side edges of the lead holes 11c and 11d themselves are formed so as to be curved so that the lead terminal The disconnection of 14a and 14b can be prevented.

[0032]

[Effect of the device]

 As described above, according to the present invention, it is possible to provide an extremely excellent fixed coil which can be configured in a small size, has a small leakage magnetic flux, and is hard to cause magnetic saturation.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of a fixed coil according to the present invention.

2 is a bottom view of the fixed coil of FIG. 1. FIG.

FIG. 3 is a side view in which a part of the fixed coil of FIG. 1 is cut away.

FIG. 4 is an exploded perspective view of the fixed coil of FIG.

FIG. 5 is a sectional view showing another embodiment of a fixed coil according to the present invention.

FIG. 6 is a cross-sectional view showing an example of a conventional fixed coil.

FIG. 7 is a perspective view showing another example of a conventional fixed coil.

[Explanation of symbols]

 10 Fixed Coil 11 Base 11a Terminal Board 11b Terminal Board 11c Lead Hole 11d Lead Hole 12 Adhesive 13 Vase Core 13a Central Core 14 Air Core Coil 14a Lead Terminal 14b Lead Terminal 15 Conductor

Claims (5)

[Scope of utility model registration request] 1. A pot-shaped core provided with a base and a central core portion made of a magnetic material fixedly held on the base via an adhesive, and the central core portion in the pot-shaped core. An air-core coil mounted so as to surround the air-core coil. After penetrating a lead end of the air-core coil through the base, the adhesive is cured to fix the pot core to the base. A fixed coil, characterized in that 2. The fixed coil according to claim 1, wherein the adhesive is formed by stamping a sheet-shaped adhesive. 3. Fixed coil according to claim 1, characterized in that the adhesive is provided by printing, coating or the like. 4. Fixed coil according to claim 1, characterized in that the adhesive contains a magnetic material. 5. The fixed coil according to claim 1, further comprising a conductor disposed below and below the adhesive.