JPH06204053A - Molded transformer - Google Patents

Abstract

PURPOSE:To obtain a transformer to be mounted in an electric circuit which is improved in electric dielectric strength properties between coils, and easy to assemble. CONSTITUTION:Molded air-core coils 2 are laminated in combination, which are formed by integrally molding by a sealing resin 6 an air-core coil 3 which are wound and set using insulation layers excellent in electric dielectric strength and wires having a surface viscosity property, and surface mount terminals 4 to which the winding terminals of the molded air-core 3, and the central magnetic leg of a split-type magnetic core 1 is inserted into a core central leg through-hole 7 of the molded air-core coil 2 and the magnetic core 1 is fixed by a core holder 5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transformer which constitutes an electronic circuit, and in particular, a plurality of coil molded bodies obtained by sealingly molding an air-core coil using a sealing resin are laminated to form a magnetic core in a central hole of the coil molded body. The present invention relates to a mold transformer having a stacked structure which is formed by inserting a magnetic leg and has an improved withstand voltage and is easily assembled.

[0002]

2. Description of the Related Art Conventionally, a transformer of this type has a structure in which a coil bobbin is used to wind a coil of a plurality of layers, a magnetic core is incorporated into the wound coil bobbin, and a varnish is impregnated in order to improve the electric withstand voltage. Etc., and the outer periphery is molded with a sealing resin. In the conventional transformer, the coil bobbin facilitates winding work, but it is necessary to separately prepare a coil bobbin for each transformer with different specifications. When using a coil bobbin, the winding is the primary winding. Since the insulating layer is wound on and the secondary side is directly wound, there arises a problem that the electrical withstand voltage characteristic sometimes shows a low value. Most of the lead wires at the winding ends are of a type that is inserted into the board, and not of the surface mounting type.

[0003]

SUMMARY OF THE INVENTION In order to solve these problems, the present invention forms a plurality of windings of an air-core coil in which the primary side and the secondary side are independent of each other in advance, and seals each coil. A resin is molded with a molding resin, and surface-mounted terminals are formed in advance on the coil that has been molded by encapsulation, and the resin molded coil is laid on top of one another. When the resin molded coil is constructed, the coil is formed on the side curved portion of the resin molded coil. A recess is provided to display the contents of each specification, and the coils that are combined depending on the position of the recess are made to be recesses at the same position to prevent incorrect assembly and stacking. Therefore, the purpose of the present invention is to provide a transformer that eliminates the withstand voltage failure of the electrical insulation characteristics and emphasizes high reliability and safety.

[0004]

SUMMARY OF THE INVENTION According to the present invention, a molded air-core coil having a high electrical withstand voltage characteristic, in which the primary side and the secondary side are resin-molded with independent molding resins, has a curved side surface. A recess is provided in the part, and the position and the number of the recess are varied according to the specifications of the number of turns to prevent erroneous assembly and stacking. For each coil, the coil is separated and insulated by the sealing resin. Unlike the conventional transformer in which the insulation distance from the secondary coil is increased and the coil winding is wound around the conventional coil bobbin, the transformer has eliminated electrical defects such as withstand voltage characteristics.

That is, the present invention is as follows. A mold air-core coil formed by connecting a winding end of a coil wound a plurality of times to a surface-mounting terminal, covering the coil with a sealing resin and integrally molding the surface-mounting terminal, and laminating a plurality of the mold air-core coils, The mold transformer is formed by inserting and combining the central magnetic leg of the split type magnetic core having the magnetic legs on both sides and the central magnetic leg into the core central through hole of the molded air-core coil, and locking both sides of the magnetic core by the core holder. 2. The mold transformer is characterized in that a concave portion for displaying the specifications of the coil is provided on the curved portions on both sides of the center of the molded air-core coil, and the concave air is combined with the molded air-core coil.

[0006]

The insulated wire around which the coil is wound uses 0 type of insulation-coated wire and is wound directly on the jig without using the coil bobbin to form a coil. Therefore, an extra space for the coil bobbin unlike the conventional case is not required. Therefore, the shape is small even with the same size and the same number of windings. In addition, since each coil is molded with an epoxy resin encapsulation resin to form a central hole for incorporating the central magnetic leg of the magnetic core in the center, the surfaces of the coils are laminated with each other to form a transformer, and the dielectric strength characteristics Can be an improved transformer. Further, since the coil bobbin is not used, coils having different winding specifications can be easily formed in an efficient space.

[0007]

FIG. 1 is a perspective view showing the completed appearance of a mold transformer according to the present invention, in which a central magnetic leg of a magnetic core 1 is vertically inserted with a molded air-core coil 2 and a core 1 is assembled by a core holder 5 from the vertical direction. Is locked. Figure 2
FIG. 3 is a rear view of the surface mount terminal shown in FIG. 1, and FIG. 3 is an exploded perspective view of the mold transformer according to the present invention. Core holder locking recesses 1a for fixing the magnetic core and the molded air-core coil 2 are formed at the four corners of the magnetic core 1, and the two molded air-core coils 2 obtained by molding the coil with a sealing resin are the magnetic core 1.
Placed between. FIG. 4 shows two molded air core coils 2
Shows an example in which the surface mount terminals 4 are arranged on both sides of each other, and the specification of the molded air-core coil is displayed according to the number and position of the recesses provided in the side surface curved portion of the molded air-core coil. At the center of the molded air-core coil 2, a core central through hole 7 for inserting a central magnetic leg (not shown) of the magnetic core 1 is provided, and the coil is wound around the core central through hole. Further, the surface mount terminals 4 are formed on the end faces, and the terminals become conductive to the board conductor when the molded air core coil and the magnetic core 1 are combined to form the molded transformer.

The cross-sectional shape of the molded air-core coil is shown in FIG. The surface mount terminal is a plate-shaped electrode and has a surface mount type structure.
The electric insulation coating is wound with 0 type adhesive copper wire, wound with a coil winding jig, and the lead wire 3a of the coil winding terminal is drawn out and connected to the surface mounting terminal 4. .
Therefore, the mold transformer according to the present invention is a molded air-core coil in which an air-core coil is resin-molded without using a coil bobbin, and the central magnetic leg of the ferrite core is inserted into the central through hole 7 of the stacked molded air-core coils.
The molded air-core coil is formed by using an adhesive electric wire whose surface has no electric coating, and the withstand voltage between the wires is 20.
A value of 00 V or more is guaranteed, and further, it is molded in a sealing resin, so that a high electric breakdown voltage is guaranteed between the built-in mold air core coils.

Although the embodiment of the present invention describes only the transformer, it goes without saying that the present invention can be implemented even when one molded air-core coil is incorporated in the magnetic core to form a choke coil.

[0010]

According to the mold transformer of the present invention, the air-core coil in which the primary coil and the secondary coil are separately wound is resin-molded by sealing and forming the resin-molded portion. A transformer is constructed by attaching a recess to the curved portion on the side to display the specifications of the coil and combining the recesses to prevent incorrect assembly. Moreover, since the primary coil and the secondary coil are independently wrapped around the air-core coil for resin molding, the insulation withstand voltage characteristic between the coils is improved, the withstand voltage characteristic is secured, and the mold is easy to assemble. I got a trance.

[Brief description of drawings]

FIG. 1 is an external perspective view of a mold transformer in which a mold air-core coil of the present invention is assembled.

FIG. 2 is an external perspective view showing the back surface of the surface mounting terminal of the molded air-core coil of the present invention.

FIG. 3 is an exploded perspective view of the mold transformer of the present invention.

FIG. 4 is an external perspective view showing a molded air-core coil of the present invention.

FIG. 5 is a vertical cross-sectional view of the molded air-core coil of the present invention.

[Explanation of symbols]

 1 magnetic core 1a core holder locking recess 2 molded air core coil 2a recess 3 air core coil 3a lead wire 4 surface mounting terminal 5 core holder 6 sealing resin 7 core center through hole

Claims (2)

[Claims] 1. A molded air-core coil in which a winding end of a coil wound a plurality of times is connected to a surface-mounting terminal, the coil is covered with a sealing resin, and the molded air-core coil is integrally molded with the surface-mounting terminal. A mold transformer in which a plurality of laminated magnetic cores each having a magnetic leg on both sides and a central magnetic leg are inserted into the core central through hole of a molded air-core coil, and both sides of the divided magnetic cores are locked by a core holder. . 2. The mold according to claim 1, wherein a concave portion for displaying the specifications of the coil is provided in the curved portions on both sides of the center of the molded air-core coil, and the concave air is combined with the molded air-core coil. Trance.