JPH06333769A - Fixing structure for terminal pin in small-sized electric winding component - Google Patents

Abstract

PURPOSE:To prevent the generation of cracks of a bobbin part fixing a terminal pin for surely fixing the terminal pin in the fixing structure of the terminal pin in the small-sized electric winding components. CONSTITUTION:A pin insertion hole 52 is formed of an outer hole 52a near the bobbin outer face and an inner hole 52b communicating with the outer hole 52a and a terminal pin 53 is inserted from the outer hole 52a formed larger than a sectional shape of this terminal pin 53 for being pressed in and fixed by the inner hole 52b.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure for fixing terminal pins in small winding parts such as transformers and choke coils.

[0002]

2. Description of the Related Art FIG. 7 is a vertical sectional side view showing an example of a small transformer which has been widely known in the past. This transformer has a bobbin 1 and a bobbin 1 each having a collar on both sides of a cylindrical winding portion.
The two E-shaped ferrite cores 3 and 4 installed inside, the coil 5 wound around the bobbin 1, and the terminal pin 6 which is planted in the thick portion 2 of the bobbin collar and whose coil end is fixed. ing.

8A and 8B are partially enlarged front views of the bobbin thick portion 2 into which the terminal pin 6 is inserted. In the conventional fixing structure of the terminal pin 6, the thick portion 2 is provided with a circular hole 7 shown in FIG. 8 (A) or a rectangular hole 8 shown in FIG. 8 (B), and the terminal pin 6 has a prismatic rod body. The terminal pin 6 is press-fitted into the circular hole 7 or the rectangular hole 8 to be fixed. In the case of the square hole 8, the terminal pin 6 is shown in FIG.
As shown in (B), a crushed portion 6a is provided to prevent the crushed portion from coming off.

The terminal pin 6 fixed by being planted as described above is soldered with the coil end portion being entangled just before the outer surface 2a of the bobbin thick portion 2. In this transformer, the terminal pin 6 is inserted into a mounting hole provided at a predetermined position of the printed wiring board,
It is mounted by soldering on the printed wiring board or on the back surface side of the printed wiring board.

[0005]

The conventional terminal pin fixing structure described above has the following problems. When the terminal pin 6 is press-fitted into the pin insertion hole such as the circular hole 7 or the square hole 8 provided in the thick portion 2 of the bobbin 1, a crack is generated on the outer surface of the bobbin due to the impact at the time of press-fitting and the subsequent work process , The fixation of terminal pins may become unstable. That is, in this type of small transformer, the terminal pin 6 having a square cross section with a side of about 0.42 mm is used, and the bobbin thick portion 2 cannot have a sufficient thickness width. When the crack 2 occurs, the terminal pin 6 may rattle or come out.

Specifically, the pin insertion hole is shown in FIG.
In the case of the circular hole 7 as shown in (A), it is necessary to press the terminal pin into the circular hole 7 such that the four corners 6a of the prismatic terminal pin 6 are engaged with the inner wall of the circular hole 7. Therefore, the bobbin 1 is cracked on the outer surface 2a side of the thick portion 2 by the impact when the terminal pin 6 is press-fitted.

When the pin insertion hole is the square hole 8 shown in FIG. 8B, the outer surface of the prismatic terminal pin 6 is formed into the square hole 8.
Since the terminal pin 6 is attached so as to be in close contact with the inner wall surface of the terminal, the rectangular hole 8 is formed to have substantially the same size as the sectional shape of the terminal pin 6 (the sectional shape in the direction orthogonal to the longitudinal direction). Therefore, when the terminal pin 6 is press-fitted, the impact may cause a crack as shown in the figure on the outer surface 2a side of the bobbin thick portion 2 as described above.

Further, a plurality of terminal pins 6 are implanted in the transformer. When the transformer is mounted on a printed wiring board or the like, the mounting holes of the printed wiring board and the respective terminal pins 6 are mounted.
If the and are misaligned, the tip of the terminal pin 6 is pushed in the left-right direction to align the terminal pin with the mounting hole.
For this reason, the bent portion of the terminal pin 6 is swung by the lever principle, so that the fixed portion of the terminal pin 6 is also rotated, and the crack on the outer surface 2a side of the bobbin thick portion 2 causes the terminal pin 6 to move. Sticking becomes more unstable.

When the terminal pin 6 rotates, the terminal pin 6
The coil 5 may be broken or the terminal pin 6 may be pulled out from the thick portion 2 due to pulling at the end portion of the coil fixed to the.

Therefore, it is an object of the present invention to develop a terminal pin fixing structure in a small electric winding component which can securely fix the terminal pin without causing a crack or the like on the bobbin.

[0011]

In order to achieve the above object, in the present invention, a bobbin is provided with a pin insertion hole in advance, and a terminal pin is press-fitted and fixed in the pin insertion hole. In the terminal pin fixing structure in, the pin insertion hole is connected to the outer hole which is larger than the sectional shape of the terminal pin and communicates with the bobbin surface, and the hole diameter is smaller than the outer hole. And a terminal pin inserted into the pin insertion hole through the outer hole and press-fitted and fixed in the inner hole. To propose.

Further, according to the present invention, a crushed portion can be provided in the terminal pin portion to be inserted into the inner hole of the pin insertion hole.

[0013]

In the terminal pin fixing structure of the present invention, the bobbin pin insertion hole is composed of an outer hole communicating with the outer surface of the bobbin and an inner hole communicating with the outer hole, and is formed larger than the sectional shape of the terminal pin. The terminal pin is inserted through the outer hole, and the terminal pin is press-fitted and fixed in the inner hole smaller than the outer hole.

Thus, since the terminal pin implantation portion is formed deeper than the bobbin outer surface, no impact is applied to the bobbin outer surface when the terminal pin is pressed and inserted, and the terminal pin implantation is performed. After that, even if external force is applied to the tip of the terminal pin during various processes, no impact is applied to the bobbin outer surface. As a result, it is possible to surely prevent the conventional bobbin from cracking.

By providing a crushed portion in the terminal pin portion inserted into the inner hole, the terminal pin is more firmly fixed to the bobbin, and even if external force is applied to the terminal pin, The rotation and retaining are securely prevented.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an example in which the present invention is applied to a small transformer will be described with reference to the drawings. 1 and 2 show a first embodiment of the present invention. FIG. 1 is a vertical sectional side view of a thick portion of a bobbin showing an enlarged portion of a terminal pin, and FIG. 2 is a bobbin meat for inserting the terminal pin. It is a partially expanded front view of a thick part.

As shown in these drawings, the pin insertion hole 52 formed in the thick portion 51 of the bobbin 50 is communicated with the outer hole 52a close to the outer surface of the bobbin and the outer hole 52a, and is smaller than the outer hole 52a. The inner hole 52b is formed to have a diameter, and a taper 52c for connecting the inner wall of the outer hole 52a and the inner wall of the inner hole 52b is provided.

The outer hole 52a and the inner hole 52b are
As shown in FIG. 2, the outer hole 52a is circular and the inner hole 52a is
b has a rectangular shape, the hole diameter of the outer hole 52a is larger than the cross-sectional shape of the prismatic terminal pin 53 (cross-sectional shape orthogonal to the pin axis), and the hole diameter of the inner hole 52b is the terminal pin 53.
It has almost the same size as the cross-sectional shape.

The bobbin 50 having the pin insertion hole 52 as described above is formed by molding a synthetic resin material. The pin insertion hole 52 is formed in the same manner as the pin insertion hole 52 in advance. A mold of a size is made, this mold is embedded in a predetermined position of a mold for molding the bobbin 50, and after the bobbin 50 is molded, this mold is pulled out to form.

The terminal pin 5 is inserted into the pin insertion hole 52 described above.
Terminal pin 53 from outer hole 52a larger than the sectional shape of 3
Is inserted, and the terminal pin 53 is strongly pushed deep into the inner hole 52b. At that time, the terminal pin 53 inserted through the outer hole 52a can be easily attached to the inner hole 5 by the taper 52c.
Guided to 2b.

With respect to the terminal pin 53 and the inner hole 52b, which are formed in a rectangular shape, the outer surface of the terminal pin 53 comes into close contact with the inner wall surface of the inner hole 52b, and the terminal pin 53 is securely fixed.

By constructing the pin insertion hole 52 in this way, the terminal pin 53 is fixed in the thick wall portion 51 of the bobbin, so that no shock is applied to the outer surface of the bobbin when the terminal pin 53 is attached. A crack on the outer surface of the thick portion 51 caused by the pin insertion hole 52 is reliably prevented.

When the terminal pin 53 is bent in an L-shape as shown in the drawing, an external force in the axial direction of the pin insertion hole 52 (horizontal direction in FIG. 1) is hardly applied. Therefore, the prismatic terminal pin 53 can be securely fixed only by press-fitting the prismatic terminal pin 53.

FIG. 3 shows a modification of the above embodiment, in which both the outer hole 54a and the inner hole 54b of the pin insertion hole 54 are formed in a circular shape.

That is, the pin insertion hole 54 has a circular outer hole 54a larger than the sectional shape of the prismatic terminal pin 53.
And a circular inner hole 54 into which the terminal pin 53 can be press fitted.
b, and a taper 54c for connecting the inner peripheral surfaces of the outer hole 54a and the inner hole 54b.

When the prismatic terminal pin 53 is press-fitted into the pin insertion hole 54, each corner of the terminal pin 53 bites into the inner wall of the circular inner hole 54b, so that the terminal pin is fixed. When the terminal pin is bent into the L shape as described above, the external force in the axial direction of the pin insertion hole 54 is not applied, so that the terminal pin does not come out.

Further, since there is almost no impact on the outer surface of the bobbin when the terminal pin 53 is attached, the bobbin thick portion 51 does not crack as in the above embodiment.

The shape of the pin insertion holes 52 and 54 shown in the first embodiment and the modification is not limited to these, and both the inner hole and the outer hole may be formed in a square shape, or the outer hole may be formed in a square shape. The inner hole may be formed in a circular shape or its configuration is arbitrary.

When the prismatic terminal pin has a rectangular cross section, the square portion of the pin insertion hole is formed in a rectangular shape, and the circular portion is an oblong shape in which an ellipse or a corner is rounded. I wish I had it.

Next, a second embodiment of the present invention will be described. 4 is a partially enlarged vertical side view of the bobbin thick portion similar to FIG. 1, and FIG. 5 is a vertical side view similar to FIG. 4 showing a state before the terminal pin is inserted.

The pin insertion hole 57 formed in the thick portion 56 of the bobbin 55 is formed of a circular outer hole 57a, a rectangular inner hole 57b and a taper 57c similar to the first embodiment.

On the other hand, in the prismatic terminal pin 58, the crushed portion 58 is slightly closer to the center than the tip end portion in the insertion direction of the terminal pin 58.
a is provided. That is, the crushed portion 58a is provided at the terminal pin portion inserted into the inner hole 57b.

When the terminal pin 58 having such a crushed portion 58a is inserted into the pin insertion hole 57, the crushed portion 58a
Dig into the inner wall of the inner hole 57b, so that the terminal pin 58 is more firmly fixed.

Therefore, by carrying out in this way, the terminal pin 58 can be prevented from coming off with respect to the external force of the pin insertion hole 57 in the axial direction of the hole (left and right direction in FIG. 4). As a result, the terminal pin 58 is not limited to the one bent in the L-shape as described above, but can be securely fixed even if it is linear.

In the description of the second embodiment, the pin insertion hole 57 has a circular outer hole 57a and a square inner hole 57b, but both the outer hole and the inner hole are circular or square. Alternatively, the outer hole may be rectangular and the inner hole may be circular. Further, in carrying out the present invention, as shown in FIG. 6, a pin insertion hole 7 formed by an outer hole 70 and an inner hole 71 which are tapered.
3 may be provided on the bobbin thick portion 74. Further, the present invention is not limited to the terminal pin having a rectangular cross section, but can be implemented for a terminal pin having a circular cross section. In the case of carrying out in this way, it is necessary to provide a crushed portion in the pin portion to be press-fitted into the inner hole of the pin insertion hole.

[0036]

As described above, the fixing structure of the terminal pin according to the present invention has the pin insertion hole including the outer hole near the outer surface of the bobbin and the inner hole communicating with the outer hole, and the sectional shape of the terminal pin. Since the terminal pin is inserted through the larger outer hole and press-fitted and fixed in the inner hole, it is possible to reliably prevent the bobbin from cracking when the terminal pin is inserted or in the subsequent working process.

Further, by providing the crushed portion in the terminal pin portion inserted into the inner hole of the pin insertion hole, the terminal pin is more firmly fixed, and the coil end portion fixed to the terminal pin is disconnected or the terminal pin is fixed. Can be prevented from coming out.

[Brief description of drawings]

FIG. 1 is a partially enlarged vertical side view of a bobbin showing a first embodiment of the present invention and showing an example in which the present invention is applied to a small transformer.

FIG. 2 is a partially enlarged front view of the bobbin.

FIG. 3 is a partial enlarged front view of a bobbin provided in a small transformer according to a modification of the first embodiment.

FIG. 4 is a partial enlarged vertical side view of the bobbin provided in the small transformer according to the second embodiment of the present invention.

FIG. 5 is a vertical cross-sectional side view similar to FIG. 4, showing a state before the terminal pin is attached to the bobbin.

FIG. 6 is a partial enlarged vertical side view of a transbobbin showing another embodiment of the present invention.

FIG. 7 is a vertical sectional side view of a conventional small transformer.

FIG. 8A is a partially enlarged front view of a bobbin showing a conventional example in which a terminal pin insertion hole is circular. Figure 8
(B) is a partial enlarged front view of a bobbin showing a conventional example in which the insertion holes of the terminal pins are made rectangular.

FIG. 9 (A) is an enlarged side view of a terminal pin shown as a conventional example. FIG. 9B is an enlarged bottom view of the terminal pin.

[Explanation of symbols]

 50, 55 bobbin 51, 56 thick part 52, 57 pin insertion hole 52a, 57a outer hole 52b, 57b inner hole 53, 58 terminal pin 58a crushed part

Claims (2)

[Claims] 1. A terminal pin fixing structure in a small electric winding component having a structure in which a bobbin is provided with a pin inserting hole in advance and the terminal pin is press-fitted and fixed to the pin inserting hole. It is formed by an outer hole that is larger than the cross-sectional shape of the pin and that communicates with the bobbin surface, and an inner hole that communicates with this outer hole and has a smaller diameter than this outer hole. A structure for fixing a terminal pin in a small electric winding component, characterized in that the terminal pin inserted in the mounting hole is press-fitted and fixed in the inner hole. 2. A fixing structure for a terminal pin in a small electric winding component, characterized in that a crushed portion is provided at a terminal pin portion to be press-fitted into an inner hole of the pin insertion hole.