JPH04307907A - Coil - Google Patents

Abstract

PURPOSE:To get a coil where the temperature rise of a conductive wire is small by providing a plurality of gaps in the magnetic core to be inserted in the axial hole of a bobbin thereby lessening the heat generation of the conductive wire due to the leakage of a magnetic field. CONSTITUTION:In a coil 1 where a conductive wire is wound on a drum 2a of a bobbin 2 and a magnetic core 3 is inserted in an axial hole 2b of the bottin 2, the magnetic core 3 inserted in the axial hole 2b of the bottin 2 is provided with a plurality of gaps 5. For example, the foot 3a on the side of being inserted in the axial hole 2b of the magnetic core 3 is made short, and a bar-shaped magnetic core member 6 is arranged between the feet 3a, and gaps are provided between both ends of the magnetic core member 6 and both feet 3a. And the position of the gap 5 is set so that the length L1 of the feet 3a may be equal to that L2 of the bar-shaped member 6. By providing two or more gaps 5 in the above-mentioned way, the leaked magnetic flux of the winding part is divided into two or more, the heat generation of the winding part becomes smaller than conventional transformers, and also the leaked magnetic flux to outside becomes small, and the adverse effect on the peripheral equipment also becomes small.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coil used in a transformer or the like. In particular, the present invention relates to a coil in which the conductor generates little heat due to leakage of the magnetic field from the gap in the magnetic core.

0002

[Prior Art] Conventionally, as shown in FIG. 4, a coil 101
A conducting wire is wound around a winding trunk 102a of a bobbin 102 to form a winding part 104, and a magnetic core 103 is inserted into a shaft hole 102b of the winding trunk 102a. This coil 101 is connected to the shaft hole 1
One gap 105 is provided in the magnetic core 103 inserted through the core 02b. Then, leakage magnetic flux 106 is generated to increase current capacity and linearity of magnetic flux density and coercive force.

0003

[Problems to be Solved by the Invention] However, in the above-mentioned conventional coil, the magnetic field leaks in the gap portion of the magnetic core, generating eddy current in the conductor wire and generating heat, increasing the amount of heat generated in the conductor wire in the gap portion, and causing the temperature to rise. Rise.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a coil in which the temperature rise of the conducting wire is small.

[0005]

[Means for Solving the Problems] In a coil in which a conductor is wound around the winding body of a bobbin and a magnetic core is inserted into the shaft hole of the bobbin, a plurality of gaps are provided in the magnetic core which is inserted into the shaft hole of the bobbin. It is characterized by

[0006]

[Function] By dividing the gap of the magnetic core of the winding portion into a plurality of parts as described above, the present invention reduces the leakage magnetic flux to the outside per point from the winding portion, and the gap between the magnetic cores is reduced. The eddy current generated in the conductor due to the magnetic field leaking from the wire is divided into multiple parts, the heat generated by the winding is divided, and the temperature rise per part of the winding is reduced.

[0007]

Embodiments Hereinafter, embodiments of the present invention will be explained based on the drawings. FIG. 1 is a diagram illustrating an embodiment of a coil according to the present invention. In the figure, 1 is a coil, and bobbin 2
A conductive wire is wound around the winding trunk 2a to form the winding part 4, and the magnetic core 3 is inserted into the shaft hole 2b of the bobbin 2 from both ends.
Two gaps 5 are provided.

The leg portion 3a on the side that is inserted into the shaft hole 2b of the magnetic core 3
A rod-shaped magnetic core member 6 is arranged between the leg portions 3a, and two gaps 5 are provided between both ends of the magnetic core member 6 and both leg portions 3a. The position of this gap 5 is shown in Figure 1(b).
), the length L1 of the leg portion 3a is set to be equal to the length L2 of the magnetic core member 6. By providing two or more gaps 5 as described above, the leakage magnetic flux from the winding section is dispersed into two, making the heat generation of the winding section smaller than that of conventional transformers, and also reducing the leakage magnetic flux to the outside. The negative impact on peripheral devices is also reduced. In particular, the length L2 of the magnetic core member 6, which is the gap distance, is not limited, but
A larger one is preferable in that more heat is radiated and the additional temperature rise is small. The gap 5 may be secured by, for example, interposing a resin with good heat resistance such as polypropylene resin or polyimide resin as a spacer between the leg portion 3a and the magnetic core member 6, or by interposing the spacer between the leg portion 3a and the magnetic core member 6. This may be ensured by providing a stopper in the shaft hole 2b.

FIG. 2 is a diagram illustrating another embodiment of the coil according to the present invention. In the figure, 11 is a coil, and a conductor is wound around the winding trunk 12a of the bobbin 12.
A magnetic core 13 is inserted into the shaft hole 12b of the bobbin 12 from both ends, and a bar-shaped magnetic core member 16 is arranged between the legs 13a of the magnetic core 13 to provide two gaps 15. This embodiment differs from the above embodiments in the shape of the magnetic core, but the rest is the same, so the explanation will be omitted.

The coil according to the present invention and the conventional coil were heated at a frequency of 100 KHz in a constant temperature bath at 60°C.
A comparison was made in a temperature rise test when the frequency was set to 1 MHz. In this example, the temperature was measured at the locations shown in FIG. The position of the gap L1 was set to 1/2 of the length of L2, and the clearance of the gap was set to be the same as the apparent magnetic permeability of the conventional example shown in FIG. The gap of the conventional example was shorter than the total of the two gaps of the present example. The temperature measurement points of the conventional example for comparison are the center part of the magnetic core (A) in the cross section of the gap corresponding to the measurement points of the present example, the part closer to the magnetic core of the winding part (B), and the center of the winding part. Section (C) (FIG. 4(b)). Table 1 shows the comparison results of the temperature rise test.

[0011]

[Table 1]

According to this embodiment, the frequency is 100KHz.
, 1MHz, the temperature rise is small. From this result, since the gap is divided into two locations as in the above conditions, heat generation can be suppressed, and heat radiation is effectively performed to reduce the temperature rise of the conductor. In the above embodiment, an example was shown in which two gaps were provided, but there may be more than two gaps. Further, although a gap perpendicular to the axis of the magnetic core is shown, a gap along the axis of the magnetic core may also be provided. In addition, the present invention can be implemented with various changes and modifications without departing from the gist thereof.

[0013]

[Effects of the Invention] According to the coil of the present invention, the leakage magnetic flux from the gap of the magnetic core is dispersed into multiple parts, so that the heat generation of the conductor due to the leakage of the magnetic field can be reduced, and the leakage magnetic flux to the outside is also reduced, so that the leakage flux to the peripheral equipment is reduced. The negative effects will also be smaller.

[0014]

[Brief explanation of drawings]

FIG. 1 is a diagram showing an embodiment of a coil according to the present invention;
(a) is a perspective view thereof, and (b) is a longitudinal sectional view thereof.

FIG. 2 is a longitudinal sectional view showing another embodiment of the coil according to the present invention.

FIG. 3 is a longitudinal cross-sectional view showing measurement points in a temperature rise test of a coil according to the present invention.

FIG. 4 is a diagram showing a conventional coil, in which (a) is a perspective view thereof, and (b) is a longitudinal sectional view thereof.

[Explanation of symbols]

1,11 Coil 2,12 Bobbin 2b, 12b Shaft hole 3,13 Magnetic core 5,15 Gap

Claims (1)

[Claims] Claim 1: A coil in which a conductive wire is wound around a winding body of a bobbin and a magnetic core is inserted into an axial hole of the bobbin, characterized in that a plurality of gaps are provided in the magnetic core to be inserted into the axial hole of the bobbin. coil.