JPH0624168B2 - Transformer - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transformer used in various audio equipment, video equipment, industrial equipment, and the like.

Structure of conventional example and its problems In recent years, electronic devices have become more and more synonymous with the term "light, thin, short and small" by making full use of ICs and LSIs to achieve high functionality and high density to realize light weight and small size, and the progress has stopped. I don't know where.

The electronic components that form the basis of it all meet the demand. ICs, LSIs, LCR components, etc. are being made into chips in order to support lighter, thinner, shorter, and smaller products, and mounting on a printed circuit board is progressing from an insertion type to a so-called sticking type in which solder is placed on the printed circuit board.

A conventional transformer will be described below with reference to the drawings.

FIG. 1 shows a winding frame seen from above used in a conventional transformer, FIG. 2 shows a conventional winding frame seen from the pin side, and FIG. 3 shows the transformer mounted on a printed circuit board.

Reference numeral 1a is a lower end flange of the reel 1, 2 is a metal pin terminal implanted on the lower surface of the lower flange 1a, 3 is a reel barrel of the reel 1, and 4 is a lead wire of a coil wound on the reel 1. 5 is a drawer groove, 6
Is a projection for hooking a lead, 7 is an iron core made of a magnetic material, 8
Is a case, 9 is a printed circuit board to be mounted, 10 is solder, 1
Reference numeral 1 represents a coil wound around a winding frame, and 12 represents a protruding pin. The conventional reel 1 includes a reel barrel 3, a lower end collar 1a, and a lower end collar 1a.
It is composed of a metal pin terminal 2 embedded in. Reel body 3
The lead wire 4 of the coil 11 wound around is wound around the metal pin terminal 2 which is planted in the lower end collar 1a which is hooked on the protrusion 6 provided on the side surface of the lower end collar 1a through the lead-out groove 5. Then, the lead wire 4 and the metal pin terminal 2 are soldered, the iron core 7 is inserted, and the assembly is completed.

The method of attaching the transformer to the printed circuit board 9 is as shown in FIG. The metal pin terminals 2 are inserted into the holes provided in the printed board 9, and the metal pin terminals 12 protruding from the printed board 9 are soldered and fixed to the metal pin terminals 12. Therefore, the metal pin terminal 12 protruding from the printed board 9 is cut so that the metal pin terminal 12 does not come into contact with other circuits, a large dimension is secured in design, and an insulator is inserted. ing. In addition, the transformer structure requires a size for winding the REIT wire 4 around the root of the metal pin terminal 2 planted in the lower end collar 1a, and there is a large loss due to the restriction of the height size and the set itself becomes large. It is a factor. Further, in terms of cost, there are many drawbacks such as cutting man-hours, man-hours for inserting an insulator, cost of insulating material, and increase in material cost due to increase in size. With such a background, a method of putting components on the printed board 9 and soldering them to the printed board 9 is being adopted on the set side. An example is shown in FIG. It is impossible to attach as it is by the conventional method, and even if the temporary metal pin terminal 2 is deformed by bending or the like, a load is applied to the lead wire 4 wound around the base of the metal pin terminal 2 and soldered, which causes disconnection. This will cause it to occur. Further, when the metal pin terminal 2 is processed, the hole of the plastics molded product in which the metal pin terminal 2 is implanted is deformed, and the strength of the metal pin terminal 2 itself around which the lead wire 4 is wound deteriorates and the metal pin terminal 2 is weak against impact There was a defect that it became a bowl.

SUMMARY OF THE INVENTION In view of the above-mentioned drawbacks, the present invention provides a transformer capable of automatic winding wiring, easily attached and soldered to a printed circuit board with high impact resistance, and capable of realizing a light, thin, short and small set and cost reduction. It is intended to be provided.

In order to achieve this object, the transformer of the present invention has a plate-shaped metal terminal having at least a side surface portion and a bottom surface portion fixed to a terminal portion provided at a lower end portion of a collar of a winding frame around which a coil is wound. , The lead of the coil is connected to the metal terminal, and an iron core is incorporated in the winding frame. With this structure, a part of the metal terminal is printed in advance with a solder paste to attach a printed circuit board. The soldering can be performed by contacting with and passing through a reflow furnace set to a specified temperature.

Description of Embodiments Embodiments of the present invention will be described below with reference to the drawings. 4 is a reel of the present invention seen from above, FIG. 5 is a reel of the present invention seen from below, FIG. 6 shows an example of a metal terminal, and FIG. 7 is a printed circuit board of the present invention. Shows the transformer mounted in.

13 is a reel made of a synthetic resin molded product.
Collars 15 and 16 are provided at both ends of the bobbin barrel 14, and terminal portions 17 are integrally provided at the lower ends of the collars 15 and 16,
Several lead lead-out grooves 18 are provided in this terminal portion 17, and several plate-shaped metal terminals 19 are attached. That is, a horizontal fixing hole 20 is provided on the outer side surface of the terminal portion 17, and a vertical engaging hole 21 is provided on the lower end surface. The metal terminal 19 is attached to the fixing hole 20 and the engaging hole 21. ing. The metal terminal 19 has a fixing portion 19a that fits into the fixing hole 20, a side surface portion 19b that is continuous with the fixing portion 19a, and a bottom surface portion 19c that is continuous with the side surface portion 19b.
And the engaging hole 2 that rises upward at the tip of the bottom surface portion 19c.
1 is formed by an engaging portion 19d that fits in, and the side surface portion 19b is provided with a lead connecting piece 22 by cutting and raising so as to project outward. By fitting the fixing portion 19a into the fixing member 20 and fully inserting the fixing portion 19a, the engaging portion 19d fits into the engaging hole 21 and is firmly fixed. For this reason, it is desirable that the metal terminal 19 be composed of an elastic metal plate.

A coil 23 is wound around such a winding frame 13, and the coil lead 24 at the beginning and end of the winding of the coil 23 is drawn out through the lead drawing groove 18, and the connecting piece 22 of the metal terminal 19 is drawn.
Wrapped around, soldered and connected.

An EI-type or EE-type iron core 25 made of ferrite or a laminated iron core is incorporated in the winding frame 13, and an outer case 26 is put over the whole to form a transformer.

The mounting method in the set is shown in FIG. A portion of the printed board 27 that is connected to the transformer is preliminarily printed with solder paste, and the transformer having the metal terminals 19 is placed thereon. And controlled by a predetermined temperature,
By passing through the reflow furnace, the transformer and the circuit of the printed board 27 are soldered and connected by the solder 28. The soldering area can be increased, and the winding frame 13 itself is strengthened by fitting the metal terminal 19 and the molded product to each other, so that the transformer is resistant to shock such as vibration and drop.

In addition to the above-described embodiment, the metal terminal 19 may be configured to have a side surface portion and a bottom surface portion welded to the terminal portion 17.

EFFECTS OF THE INVENTION As described above, the present invention has a structure in which a part of the metal terminal attached to the terminal portion of the reel directly contacts the circuit of the printed circuit board and is passed through the reflow furnace for soldering connection. The front and back of the printed circuit board can be used, and the soldering process becomes easier. In addition, since the coil lead is connected to the connection piece provided on the side surface of the metal terminal, the transformer main body uses the bottom surface without the connection piece after the metal terminal is soldered to the printed circuit board without breaking the wire. Since it is connected to the printed circuit board, it does not float above the printed circuit board, and the mounting strength becomes a solid and stable structure, which is expected to contribute to the lightweight, compact size, high strength, high functionality, and cost reduction of recent electronic devices. The effect is great.

Further, in terms of the manufacturing of the transformer as well, it has an advantage that it can provide a transformer having a structure that allows automatic winding wiring, has a strong terminal strength, and is excellent in quality, and is of great industrial value.

[Brief description of drawings]

FIG. 1 is a perspective view of a reel used in a conventional transformer, FIG. 2 is a perspective view of a main part of the reel seen from below, and FIG. 3 is mounting of the transformer in a conventional set on a printed circuit board. FIG. 4 is a cross-sectional view showing the state, FIG. 4 is a perspective view of a bobbin used in the transformer of one embodiment of the present invention, FIG. 5 is a perspective view of the main part of the bobbin seen from the lower surface, and FIG. 6 is the same metal. Exploded perspective view explaining the terminal installation,
FIG. 7 is a sectional view showing a mounting state of the transformer set of the present invention on a printed circuit board. 13 ... reel, 14 ... reel barrel, 15, 16 ... Tsuba, 1
7 ... Terminal part, 18 ... Lead lead-out groove, 19 ... Metal terminal, 19a ... Fixing part, 19b ... Side part, 19c ...
... Bottom part, 19d ... Engaging part, 20 ... Fixing hole, 21 ...
… Engagement hole, 22 …… Connecting piece, 23 …… Coil, 24 ……
Reed, 25 ... Iron core, 26 ... Case.

Claims (1)

[Claims] 1. A terminal portion provided at a lower end portion of a brim of a winding frame around which a coil is wound has at least a side surface portion and a bottom surface portion, and a connecting piece formed by cutting and raising the side surface portion is projected outward. A transformer in which the plate-shaped metal terminal thus provided is fixed, the lead of the coil is connected to the connecting piece of the metal terminal, and the iron core is incorporated in the winding frame.