JP2841300B2 - Bonding structure of terminal pins for small winding parts - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fixing structure of a terminal pin for a small winding component such as a choke coil and a transformer.

[Prior Art] FIG. 4 shows a longitudinal sectional view of a conventional transformer. This transformer comprises a bobbin 1 having flanges on both sides of a cylindrical winding portion, two ferrite cores 2 of the same shape provided inside the bobbin 1,
3, a coil 4 wound around the bobbin 1, and a terminal pin 5 implanted and fixed to the thick portion of the flange of the bobbin 1.

FIG. 5 is an enlarged sectional view of the bobbin flange portion showing a portion where the terminal pin 5 is implanted, and FIG. 6 is a partially enlarged bottom view of the bobbin flange for inserting the terminal pin 5 therein.

As shown in these figures, in the conventional terminal pin fixing structure, a circular hole 6 is provided on the bottom surface of the flange portion of the bobbin 1, and a terminal pin 5 is formed with a crush 5a for preventing the terminal pin 5 from coming off in a part of the area where the terminal pin 5 is to be planted. The terminal pin 5 is press-fitted into the circular hole 6 to be fixed to a prismatic rod.

The end of the coil is tied to the terminal pin 5 implanted and fixed just above the bottom surface of the bobbin flange, and the kinked portion 5b is fixed by soldering.

In addition, since the above-mentioned transformer is used as a reflow type, the lower part of the barb 5b is bent into an L-shape. That is, this transformer is mounted on a predetermined portion such as a printed wiring board, and the bent portion of the terminal pin 5 is soldered by an automatic soldering device or the like and mounted.

"Problem to be Solved by the Invention" The conventional fixing structure described above has the following problems.

(1) Only the outer corners of the prismatic terminal pin 5 are in contact with the inner wall of the circular hole 6 provided in the thick portion 1a of the bobbin flange, and the contact area is extremely small. After the insertion and fixing, when an external force, an impact force, or the like is applied to the tip of the terminal pin 5 during various processes, the bent portion of the terminal pin 5 pivots according to the principle of leverage, and the terminal pin 5 is fixed. The part also rotates.

For this reason, the terminal pin 5 comes off from the thick portion 1a, and the coil end portion is pulled by the rotation of the terminal pin 5 to be disconnected, which causes a failure.

(2) Since the bent corners of the L-shaped terminal pins 5 are formed somewhat rounded, a step of soldering the coiled ends 5b after the coil ends are bent at the pin portions If the terminal pin 5 is swiveled before as described above, the end portion of the coil is loosened, and the loosened portion of the coil may come off from the rounded L-shaped corner.

"Means for Solving the Problems" The present invention has been developed in view of the above-described problems, and has a coil wound on a bobbin having a flange, is formed substantially in an L shape, and a vertical portion thereof is defined as a flange surface direction. A terminal pin implanted and fixed to the flange, wherein the coil end portion of the coil is fixed to a terminal pin portion close to the flange, wherein the bobbin flange has a rounded corner. A configuration in which a square hole is formed in the direction of the flange surface, the terminal pin is a prism having a quadrangular cross section, a crush portion is provided in a vertical portion thereof, and the vertical portion of the terminal pin is pressed into the square hole and fixed. The present invention proposes a structure for fixing a terminal pin for a small-sized winding component, characterized in that:

[Operation] The terminal pin fixing structure of the present invention press-fits and fixes a prismatic terminal pin into a square hole provided in a flange of a bobbin, so that the outer surface of the terminal pin is in close contact with the inner wall surface of the square hole.

The square hole is formed by rounding the corner so that a crack is not generated in the corner due to an impact when the terminal pin is inserted.

Such a terminal pin is not limited to a means for bending after being implanted, but it is also possible to implant an L-shaped one in advance, and the crushed portion of the terminal pin is formed before being fixed.

"Example" Next, an example of the present invention will be described with reference to the drawings.

FIG. 1 is an enlarged sectional view of a flange portion similar to FIG. 5, and as shown in FIG.
Has been planted. The terminal pin 7 has a prismatic shape as in the conventional example, and is provided with a crush 7a slightly below the tip of the area where the terminal is to be planted in order to prevent the terminal pin 7 from slipping out.

On the other hand, FIG. 2 is a partially enlarged view of the flange bottom surface similar to FIG. 6, and as shown in the figure, a rectangular hole 8 having a rectangular shape is formed in the thick portion 1a of the bobbin flange in order to implant the terminal pin 7. It is formed. The square hole 8 is formed slightly smaller than the quadrangular cross-sectional area of the terminal pin 7 and each corner is rounded so that the corner is not broken by an impact when the terminal pin 7 is inserted.

By inserting the prismatic terminal pin 7 into the rectangular hole 8 formed in this way, the inner wall surface of the rectangular hole 8 and the outer surface of the terminal pin 7 are in close contact with a large contact area, and furthermore, they are square with each other. In addition, since the corners of the terminal pins 7 bite into the corners of the rectangular holes 8, the planted portions of the terminal pins 7 are securely fixed.

As a result, the terminal pins 7 hardly loosen or come off during the transformer production process or after assembly. In addition,
The terminal pin 7 inserted and fixed is bent into an L-shape as in the conventional example.

The terminal pins 7 are implanted and fixed in advance before the bobbin 1 is equipped with a coil, the ends of the coil are tied, and the kinked portion 7b is soldered and fixed.

The terminal pin 7 is provided with a crush 7c in the entire region or a partial region of the pin portion protruding from the bobbin 1 except for the fastening portion at the coil end.

As shown in FIG. 1, of the pin portion projecting from the thick portion 1a of the bobbin 1, a crush 7c including an L-shaped corner portion is provided slightly below the barb portion 5b. This crush 7c may be provided up to the tip of the terminal pin 7.

FIG. 3 is a partially enlarged view showing the side surface of the bobbin 1.

As can be seen from this figure, the width of the terminal pin 7 in the crushing portion 7c is widened, and the lashing portion 7b is loosened, thereby preventing the lashing portion 7c from coming off.

[Effect of the Invention] As described above, in the terminal pin fixing structure according to the present invention, the prismatic terminal pin is press-fitted and fixed in the square hole of the bobbin, so that the outer surface of the terminal pin is formed on the inner wall surface of the square hole of the bobbin. Since the terminal pins are securely in contact with each other, and are square with each other, and the corners of the terminal pins bite into the corners of the square holes of the bobbin flange, rotation of the terminal pins in the planting area is effectively prevented.

In addition, since the square hole of the bobbin flange has a rounded corner, the corner is not broken when the terminal pin is press-fitted.

Therefore, the terminal pins hardly come off even after the small winding component is assembled, as well as the production process of the small winding component, and the failure due to the disconnection of the coil end is extremely reduced.

[Brief description of the drawings]

The drawings show an embodiment in which the present invention is embodied as a small transformer. FIG. 1 is a partially enlarged sectional view of a bobbin provided in the transformer showing a terminal pin planting portion, and FIG. 2 is a flange bottom surface of the bobbin. FIG. 3 is a partial enlarged side view of the bobbin showing terminal pins implanted in the bobbin;
4 to 6 show a conventional example. FIG. 4 is a longitudinal sectional view of a conventional transformer, and FIG. FIG. 6 is a partially enlarged view showing a bottom surface of a flange of the bobbin. 1 ... bobbin 2, 3 ... core 4 ... coil 7 ... terminal pins 7a, 7c ... bushing 7b ... barbed part 8 ... square hole

Claims (1)

(57) [Claims] A coil wound around a bobbin having a flange;
A small pin formed substantially in an L-shape, having a terminal portion implanted and fixed to the flange with its vertical portion as a flange surface direction, wherein a coil end portion of the coil is fixed to a terminal pin portion close to the flange. In the wire part, the bobbin flange has a square hole with a rounded corner formed in the flange surface direction, the terminal pin has a rectangular column shape with a quadrilateral cross section, and a vertical portion provided with a crushed portion, A structure for fixing a terminal pin for a small winding component, wherein a vertical portion of the pin is press-fitted into the rectangular hole and fixed.