JP2001297924A - Transformer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase the cross-section area of a coil and ensure an insulation distance without changing the outer diameter of the coil. SOLUTION: A transformer 1 has such a structure that a primary coil 3 and a secondary coil 4 are formed of an annular conductor plate and are laminated with an insulation member interposed, and a core 6 is inserted into the center of the coil. The respective annular conductor plates constituting the primary coil 3 and secondary coil 4 are provided with at least a pair of positioning projections 8 and 9 like a gear to position a coil against a core center 6a on their inner circumferences 3c and 4c. While the primary coil 3 and secondary coil 4 are laminated, the positioning projections 8 and 9 are arranged at such a position that they may be deviated with each other without facing.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transformer used for a switching power supply, and more particularly to a transformer having a structure in which a conductor plate is used for a primary coil and a secondary coil.

[0002]

2. Description of the Related Art Conventionally, in a transformer used for a switching power supply, in order to reduce an increase in copper loss due to an increase in current flowing through the coil, a sufficient effective sectional area is secured in a primary coil and a secondary coil. A transformer using a conductive plate that can be used is used. As this type of transformer, for example, there is a transformer shown in FIG.

In FIG. 7, a transformer 101 has a core 10
6, a primary coil 103 and a secondary coil 104 formed of a ring-shaped conductor plate are stacked and arranged via an insulating paper 105 with respect to a core central portion 106a.

FIG. 8 shows the primary coil 103 and the secondary coil 104 shown in FIG. 7, and the insulating paper 105 interposed therebetween is omitted. Primary coil 103 and secondary coil 104
Are coil terminals 103a, 103b and 104a, 10
4b are supported and fixed to a frame (not shown) so as to be concentric with the core central portion 106a.

[0005]

However, in a transformer using such a conventional conductor plate for a primary coil and a secondary coil, the primary coil 1
03 and the secondary coil 104 are supported and fixed to the coil terminal 103.
a, 103b and 104a, 104b, the position of the coil with respect to the core center 106a at the time of assembling the transformer does not become an ideal concentric arrangement as shown in FIG. It often shifts in the range.

In order to secure a sufficient insulation distance L even if a displacement occurs when the coils are arranged in the conventional transformer, the inner diameter of the conductor plate of each coil is increased as shown in FIG. taking it. By increasing the inner diameter of the conductor plate in this way, even if the primary coil 103 is shifted to the right as shown in FIG.
4 can secure a sufficient insulation distance L between the inner circumferences.

However, if the inside diameter of the conductor plate is increased to secure the insulation distance, the effective cross-sectional area of the conductor plate becomes small, and there is a problem that the loss of the transformer increases, which is solved. Therefore, when the outer diameter of the conductor plate is increased, there is a problem that the transformer becomes larger.

SUMMARY OF THE INVENTION An object of the present invention is to provide a transformer having a structure in which the coil cross-sectional area is increased and the insulation distance is secured without changing the coil outer diameter.

[0009]

In order to achieve this object, the present invention is configured as follows. First, the present invention has a structure in which a primary coil and a secondary coil are formed of a ring-shaped conductor plate, and the primary coil and the secondary coil are arranged so that a core passes through a center portion in a state of being laminated via an insulating member. Targets transformers.

[0010] With respect to such a transformer, the present invention provides at least one pair of gear-shaped projections and recesses on the inner periphery of each ring-shaped conductor plate serving as a primary coil and a secondary coil, which position the coil with respect to a core located at the center. Are formed, and the primary coil and the secondary coil are arranged in a stacked state at a position shifted from each other without the positioning projections facing each other.

Here, the positioning protrusions formed on the inner circumferences of the primary coil and the secondary coil have a distance from the inner circumference of another ring-shaped conductor opposed via an insulating member so as to secure a specified insulating distance. With.

As described above, according to the present invention, the positioning projections having gear-shaped irregularities are formed on the inner periphery of the conductor plate of the primary coil and the secondary coil and are arranged so as not to be opposed to each other. By contacting the core passing through the center,
The coil is positioned and fixed concentrically with respect to the core to prevent the coil conductor plate from shifting and to secure a specified insulation distance. At the same time, by reducing the inner diameter of the conductor plate and bringing the inner peripheral side closer to the core, the effective cross-sectional area of the conductor plate is increased, and the loss of the transformer is reduced.

[0013]

FIG. 1 is an explanatory view of an embodiment of the present invention.

Referring to FIG. 1, a transformer 1 according to the present invention comprises a primary coil 3 using a ring-shaped conductor plate on a transformer frame or a frame 2 formed of resin as a bobbin.
Similarly, a ring-shaped insulating paper 5 is interposed between the secondary coil 4 and the secondary coil 4, and the core 6 is arranged so that the center of the core passes through the inside of the coil.

The primary coil 3 has a pair of coil terminals 3a, 3
b is fitted in the recess of the frame 2 to support it in a cantilevered state. This is the same for the secondary coil 4, wherein the pair of coil terminals 4 a and 4 b are fitted in recesses on the opposite side of the frame 2 to support the frame in a cantilevered state.

As shown in FIG. 2A, the coil terminals 3a and 3b are connection terminals 10 having notched portions of the coil terminals 3a fixed to pads 11 of a substrate 13 by soldering.
And fixed by soldering 12 as shown in FIG. This is the same for the coil terminals 4a and 4b of the secondary coil 4. The coil terminals 3a, 3b, 4
The connection structure of the substrates a and 4b to the substrate is not limited to that shown in FIG. 2 and may be an appropriate structure such as setting pins on the substrate and soldering the coil terminals.

FIG. 3 is a sectional view of FIG.
The primary coil 3 and the secondary coil 4 are stacked and arranged concentrically with respect to a. Core center 6a
An insulation structure, such as winding an insulation tape, is applied to the outside of the core, that is, around the core middle foot. Instead of using an insulating structure such as wrapping an insulating tape around the center foot of the core, a bobbin may be used.

FIG. 4 shows the primary coil 3 and the secondary coil 4 of FIG.
The insulating paper 5 is omitted and shown in a plane. The primary coil 3 and the secondary coil 4 have a structure shown in FIG.

FIG. 5A shows a primary coil 3, in which a coil inner circumference 3c has a small inner diameter close to the core center 6a, and a gear is located at a position facing the center through two centers of the coil inner circumference 3c. The positioning projection 8 is formed by a concave and convex shape, and the inner circumference 8a of the positioning projection 8 has the same inner diameter as the outer diameter of the core central portion 6a.

FIG. 5B shows the secondary coil 4. The inner circumference 4c of the coil has a small inner diameter close to the center 6a of the core, and the gear is located at a position facing the center of the two inner circumferences 4c of the coil. The positioning protrusion 9 is formed by a concave and convex shape, and the inner periphery 9a of the positioning protrusion 9 has the same inner diameter as the outer diameter of the core central portion 6a.

The positioning projections 9 of the secondary coil 4 are positioned such that the positioning projections 8 and 9 are shifted from each other without being opposed to each other when they are superimposed on the primary coil 3 as shown in FIG. They are formed at 90 ° different positions.

When the primary coil 3 and the secondary coil 4 having the positioning projections 8 and 9 having the shapes shown in FIG. 5 are stacked and arranged with respect to the core center 6a as shown in FIG. The primary coil 3 and the secondary coil 4 are positioned so as to be concentric with the center 9 of the core 6a. In this state, the coil terminals 3a, 3b and 4a, 4b are fixed to the frame 2 as shown in FIG. This provides a positioning structure that does not cause displacement of the coil.

The insulation distance between the inner circumference of the primary coil 3 and the inner circumference of the secondary coil 4 is, as shown in FIG. The insulation distance L between the coil 4c and the diameter of the coil inner circumference 4c can be arbitrarily set to secure a required insulation distance. This is the same for the insulation distance between the positioning protrusion 9 of the secondary coil 4 and the primary coil 3.

Further, a primary coil 3 and a secondary coil 4
The inner circumferences 3c and 4c of the above have a small inner diameter close to the core central portion 6a, so that the effective sectional area of the conductor plate is increased,
Reduce transformer losses.

FIG. 6 shows another embodiment of the present invention.
The first coil 3 and the second
It is characterized by comprising only the coil 4 and the core 6.
As shown in FIG.
a, 3b and 4a, 4b are fitted to the connection terminals 10 of the substrate 13 and soldered, and the core 6 is fixed by applying silicone rubber to the substrate. Alternatively, the first coil 3 and the second coil 4 may be fixed to the core 6 by impregnating with varnish.

In the above embodiment, the case where a pair of positioning projections are formed on the inner circumference of the coil is taken as an example. However, the number of positioning projections is further increased to three or four. May be increased.

In the above embodiment, the primary coil and the secondary coil
Although the case where the next coil has one turn has been described as an example, a plurality of turns may be used. In the case of a plurality of turns, two or more positioning protrusions may be formed in a specific turn.

[0028]

As described above, according to the present invention, 1
The positioning of the conductor plate used for the secondary coil and the secondary coil with respect to the core can be ensured, and the insulation distance can be secured without excessively increasing the inner diameter of the conductor plate. Loss can be reduced.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing an embodiment of the present invention.

FIG. 2 is an explanatory view of a structure for attaching the coil terminal of FIG. 1 to a substrate.

FIG. 3 is a sectional view of FIG. 1;

FIG. 4 is an explanatory view showing a stacked arrangement by taking out a first coil and a second coil of FIG. 3;

FIG. 5 is an explanatory view of a first coil and a second coil of the present invention.

FIG. 6 is an explanatory view showing another embodiment of the present invention which does not use a frame.

FIG. 7 is a sectional view of a conventional transformer.

FIG. 8 is an explanatory view showing the stacked arrangement by taking out the first coil and the second coil of FIG. 7;

FIG. 9 is a sectional view when the primary coil is displaced;

[Explanation of symbols]

 1: Transformer 2: Frame 3: Primary coil 3a, 3b, 4a, 4b: Coil terminal 3c, 4c: Inner circumference of coil 4: Secondary coil 5: Insulating paper 6: Core 6a: Core central part 8, 9: Positioning Projections 8a, 9a: Inner circumference of positioning projection 10: Connection terminal 11: Pad 12: Soldering 13: Board

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Claims (2)

[Claims] 1. A transformer having a structure in which a primary coil and a secondary coil are formed of a ring-shaped conductor plate, and the primary coil and the secondary coil are arranged on a core passing through a center portion in a state of being laminated via an insulating member. In at least one pair of positioning projections formed by gear-shaped irregularities for positioning the coil with respect to the core passing through a central portion, on the inner periphery of each ring-shaped conductor plate serving as the primary coil and the secondary coil, A transformer, wherein the positioning projections are arranged at positions shifted from each other without being opposed to each other in a stacked state of a primary coil and a secondary coil. 2. The transformer according to claim 1, wherein
The positioning protrusions formed on the inner periphery of the secondary coil and the secondary coil have a protrusion amount such that a distance from the inner periphery of another ring-shaped conductor opposed via the insulating member secures a specified insulation distance. And a transformer.