JPH0338811Y2 - - Google Patents

Description

[Detailed description of the invention] <Industrial field of application> This invention relates to an external lead wire connection structure for coils and bobbins constituting a transformer, and is particularly applicable to transformers having inner and outer coils and bobbins. This invention relates to a connection structure between a coil terminal and an external lead wire that is effective when applied to an inner coil bobbin.

<Prior art> Connection methods and connections aimed at improving workability and ensuring tensile strength through external lead wires when connecting both ends of a coil wound around a bobbin to external lead wires. Various structures have been proposed in the past.

These types can be categorized as follows: those in which a terminal block is formed at the axial end of the bobbin and terminal pins are provided on it; those in which a member is provided that bites against the outer lead wire sheathing; those in which the outer lead wire is forcibly attached They can be divided into three types: those that generate friction by bending, etc. However, these may be used in combination with each other.

First, those belonging to the above category are typically those shown in FIGS. 5A and 5B. This is introduced as a conventional example in Japanese Utility Model Publication No. 59-27604, and briefly described, it has the following structure.

The transformers in question each have an inner coil bobbin 20 molded from a suitable synthetic resin.
and an outer coil bobbin 10, and a distinctive external lead wire connection structure can be seen on the inner coil bobbin 20.

That is, a pair of thick terminal blocks 23, 23 protruding in the direction perpendicular to the axis is provided in the collar part 22 at one end of both ends facing each other in the axial direction with the winding part 21 of the coil (not shown) in between. A suitable number of terminal pins 24, 24 are formed to protrude in the axial direction.

Regarding the terminal blocks 23, 23, the terminal pins 24, 2
There is an L-shaped slit 2 on the side and side part of 4.
5 and 25 are cut, from which the winding start end and winding end end of the coil (not shown) are pulled out.
It is designed to be attached to terminal pins 24, 24.

The external lead wires 26, 26 are placed along the coil surface so as to fit into the recesses 27, 27 formed in the other flange and the slots 28, 28 of the flange 22 where the terminal block is located, and then coated. The stripped core wires are tied around the terminal pins 24, 24, and soldered together with the previously tied coil terminals as described above, thereby fixing them electrically and mechanically.

According to such a structure, the outer coil bobbin 10 is formed with a bag portion 11 in which the terminal block 23 and the terminal pin 24 are housed. The state in which they are assembled with each other is best shown in the cross-sectional view of FIG. 5B.

The method of connecting the external lead wires 12, 12 of the outer coil bobbin 10 is a primitive one, in which the core wires are simply twisted and soldered to the coil terminals 13, 13. An insulating plate 14 made of a suitable insulating material is sandwiched between the connecting portion and the coil surface.

On the other hand, structures that fall into the above category can be represented by the structure disclosed in the same Japanese Utility Model Publication No. 59-27604 as an improvement on the above structure.

This is as shown in FIGS. 6A and 6B, and the external lead wire connection structure, which is also unique in its design, is located between the outer coil bobbin 29 and the inner coil bobbin 30 that fit into each other, and This is applied to the coil bobbin 30.

A box portion 31 is formed at one end of the inner coil bobbin 30 in the axial direction. This box portion 31 is shown enlarged in FIG. 6B for easy understanding.

A groove 33 is formed in this to accommodate the external lead wires 32, 32 bent in an L-shape, and following the groove 33 is a recess 34 called a connection recess.

A slit 35 that continues to the coil winding surface is opened in the connection recess 32 , and after the coil terminal 36 is inserted into the connection recess 34 through this slit 35 , it is separated from the exposed core wire of the external lead wire 32 . It is fixed electrically and mechanically by soldering or the like.

In this structure, the L-shaped groove 33
There is a rib 37 on the side surface of the groove that bites into the covering of the external lead wire 32, and a narrow locking part 38 is formed at the opening of the groove. , to obtain tensile strength.

Finally, a typical example of the prior art that falls into the above category is the one disclosed in Japanese Unexamined Patent Publication No. 73107/1983.

This is a terminal block receiving part provided at one end of the inner coil bobbin, into which a separately prepared terminal block is fitted, and the structure of the terminal block is as shown in Figure 7. . However, in this figure, the inner coil bobbin and the terminal block receiving portion provided at one end thereof are not shown.

As shown in FIGS. 7A and 7B, the terminal block 40 has a groove 42 for bending and holding the external lead wire 41.
As shown particularly in FIG. 7B, the external lead wire 41 is inserted into the groove 42 from its tip and is folded back beyond the partition-like crosspiece 44 to be inserted through the hole 43. The external lead wire can be electrically and mechanically fixed by passing it through the hole 43, peeling off the coating from the part that comes out of the through hole 43, and connecting and soldering the coil terminal (not shown in this figure). The government is beginning to aim for this.

<Problems to be solved by the invention> The above-mentioned conventional examples all have advantages and disadvantages, and each includes problems that must be solved.

The conventional example shown in FIG. 5 related to the above category has a disadvantage in that it requires time and effort to embed and mold the terminal pins 24 in the terminal block 23. It is also disadvantageous that a metal member called the terminal pin 24 is required separately.

In addition, in recent years, a particularly thin transformer is often required. The height h must be set above a certain level, and therefore there is also a weakness in that this request cannot be satisfactorily met.

Furthermore, the thickness of the terminal pins 24 cannot be increased to meet the demand for miniaturization of transformers, and therefore, the strength thereof is also unsatisfactory.
If a large tensile force is applied to the external lead wire 26, the terminal pin 24 may easily break, and stress may be applied directly to the coil terminal.

Additionally, there is a conventional example in which the terminal pins are made to protrude laterally, but even in this case, the above-mentioned height problem only changes to a problem of the lateral overhang length, and the above-mentioned drawbacks are almost the same. ing.

On the other hand, in the conventional example shown in FIG.
Since stress is not directly applied to the coil terminals because of the ribs 37 and the locking portions 38,
It is undesirable for the locking portion 38 to bite into the sheath of the external lead wire 32.
In some cases, the core wire may be damaged, and if stress is applied, the wire is likely to break at this point.

Also, the tolerance of the diameter of the external lead wire is almost completely lost. If it is thin, the rib 37 or the locking part 3
There is no point in having the number 8,
On the other hand, if it is thick, it will not be able to fit into the groove 33 in the first place.

Furthermore, it cannot be said that the workability is high. This is because after the external lead wire 32 is bent and pushed into the groove, it is necessary to perform a tethering operation with the coil terminal 35 within the narrow connection recess 34.

In the conventional example shown in FIG. 7, the risk of damaging the sheathing of the external lead wire or locally concentrating stress is greatly reduced. However, as is obvious, the lead wire 41 is connected to the groove 4 as described above.
It is extremely troublesome to insert the tube into the through hole 43 from the hole 43 through the bending operation.

Furthermore, separately manufacturing the terminal block (integral molding is impossible due to mold cutting) is not only disadvantageous in terms of cost, but also complicates the bobbin structure and increases the number of assembly steps.

In view of the above-mentioned conventional situation, the main purpose of this proposal is to solve only the shortcomings of the above-mentioned conventional example when connecting the coil terminal wound on a coil bobbin to an external lead wire. It is something that

In other words, the purpose of the proposal can be formulated as follows.

The structure required for the coil bobbin should be as simple as possible.

No terminal pins are required.

It must also be applicable to thin coil bobbins.

Connection work must be easy to perform.

Avoid applying local stress to the external lead wire, especially its covering, due to ribs, etc.

<Means for Solving the Problems> In order to achieve the above objects, the present invention provides an external lead wire connection structure in a coil bobbin having the following configuration.

At the axial end of the coil bobbin on which the coil is wound, an overhang is provided so as to overhang in the direction perpendicular to the axis; a slit opening in the direction; a winding part of the core wire of the external lead wire rising in the axial direction from the overhanging part on the side of the open end of the slit; An external lead wire connection structure for a coil bobbin, characterized in that the external lead wire connection structure comprises: an external lead wire mooring section having a holding section; and;

<Function> The external lead wire connection structure of the above proposal is as follows:
It performs the following connection work functions. For the sake of understanding, each component is given the reference numeral used in the embodiment of the present invention described later.

The coil terminal 64 is inserted into the slit 56 formed in the overhanging portion 55 through an opening on the outside in the axially perpendicular direction, and is allowed to come out in the axial direction.

The tip core wire 63 of the external lead wire 61 with the sheath removed
is a mooring portion 57 formed on the overhang portion 55
The wire is wound around the winding portion 58 rising in the axial direction an arbitrary number of times, for example, about once.

After doing so, the core wire 63 of the external lead wire 61 and the coil terminal 64 are tied together in the remaining area of the overhanging portion 55, and the two are electrically connected by soldering or the like as appropriate.

As described above, according to the structure of the present invention, the connection work is extremely simple.

The tensile stress applied to the external lead wire 61 is not absorbed by the coating, but is counteracted by the core wire portion wound around the mooring portion or the winding portion 58 thereof.

Therefore, the coating does not shift or tear locally, and no stress is exerted on the coil terminal 64.

In addition, the formation of the overhanging portion 55 and the mooring portion 57 is as follows:
It does not require any special processing and can be easily formed using known and existing techniques, and the mold is not complicated.

Furthermore, the mooring portion 57 or the external lead wire 61
Regarding the height of the core wire winding portion 58, for example, compared to the conventional terminal pins,
Simply connect the core wire 63 of the external lead wire, for example, about once.
It is sufficient to have a height that can be wrapped around, so it can be made sufficiently low.

Note that the holding part 59 formed at the tip of the mooring part 57 and facing in the direction perpendicular to the axis is connected to the wrapping part 58 below.
To effectively prevent a core wire 63 wound around from coming off in the axial direction during the work process.

<Embodiment> FIGS. 1 to 4 show a coil/bobbin external lead wire connection structure as a preferred embodiment constructed in accordance with the idea of the present invention.

This embodiment shows the case where the present invention is applied to the inner coil bobbin in a transformer in which inner and outer coil bobbins, each molded from a suitable synthetic resin, are nested in the axial direction. 2 is a perspective view of the inner coil bobbin 50 to which the connection structure of the present invention is applied, and FIG. 3 is a plan view. It is shown in

The inner coil bobbin 50 has a coil winding part 51 around which a coil (not shown) is wound, and a core insertion hole 52 (also not shown) into which an iron core (not shown) is inserted is bored in the axial direction.

In this case, relatively thin integral flanges 53 and 54 are formed at both ends of the coil winding portion 51 in the axial direction, but in this embodiment, one of the flanges 53 shown at the top in the figure is Then, the coil winding part 51
A portion along one side of is an overhanging portion 55 that overhangs in the direction perpendicular to the axis in the present invention.

In this case, five slits 56 that are open in the direction perpendicular to the axis are cut in this projecting portion 55 at appropriate intervals.

A total of ten anchoring portions 57, one pair each, are formed along the sides of the opening of each slit 56, particularly along both sides thereof in this case.

The mooring portion 57 is composed of a rising portion or core wire winding portion 58 that rises in the axial direction from the surface of the overhanging portion 55, and a holding portion 59 that is bent back outward in the direction perpendicular to the axis from its tip.

However, in the case of this embodiment, by cutting a groove 60 horizontally from the outside in the direction perpendicular to the axis to the inside of the plate-shaped member rising from the overhanging part 55,
It looks like it is composed of a rising part 58 and a presser part 59.

In addition, in this example, as a desirable consideration,
A rear wall 66 is formed on the iron core side of the overhanging portion 55, and side walls 65, 65 are formed on both sides, and a recessed space in the axial direction is formed by these and the mooring portion group 57, . ing.

Furthermore, an external lead wire 6 is attached to the lower collar 54.
In order to pass the coils 1 and 61 along the coil in the axial direction, an appropriate number of depressions 62 are formed at appropriate intervals.

In such a structure, the connection work between the coil terminal 64 and the tip core wire 63 of the external lead wire 61 is as follows.
This is done as follows, as will be explained below with particular reference to FIG.

First, the coil terminal 64 is pulled out through the slit 56, which is convenient in position, so as to pass through the overhanging portion 55 in the axial direction.

Next, the coating on the tip of the external lead wire 61 is peeled off to expose the core wire 63.

The exposed core wire 63 is held by the holding part 59 of the mooring part 57.
Wrap it around the lower wrapping portion 58 an appropriate number of times, generally about once.

After this, the tip portion remaining beyond the winding portion 58 and the coil terminal 64 that was previously passed through the slit 56 are connected to the remaining area of the overhang portion 55, that is, in this case, the rear wall 66 and the side wall 65.
They are intertwined with each other in the hollow space surrounded by 65.

After that, if soldering or the like is performed as necessary, the connection structure of the present invention can be fully utilized.

The outer coil bobbin into which the inner coil bobbin 50 is inserted is formed with a bag portion 71 for receiving the external lead wire connection structure in the projecting portion 55, as shown in the outer coil bobbin 70 shown in FIG. 4, for example. It's good to leave it as is.

In such a structure, the aforementioned rear wall 66 and side walls 65, 65 work together with the bag portion 71 to increase the creepage distance. Simply put, it provides sufficient insulation for the iron core.

In the embodiments described above, the external lead wire connection structure according to the present invention is provided only on one side of one collar 53, but it can of course be provided on the opposite side if necessary, or on the other side. It can also be provided on the collar 54 of.

Further, the number of mooring portions 57 and the number of slits 56 are arbitrary matters, and it is not necessary that a pair of mooring portions 57 be placed on both sides of the opening of the slit 56. Regarding the shape of the mooring portion 57, in the case shown in the figure, it is a plate shape that is easiest to form, and by forming a groove 60 therein, the winding portion 58
Although the holding portion 59 is formed, other shapes may be used, for example, a cylindrical wrapping portion and a disc-shaped holding portion whose diameter is expanded at the tip thereof.

In the case of the illustrated embodiment, the slit 56 is also cut in the direction perpendicular to the axis and perpendicular to the nearest iron core surface. It's okay if it's cut.
Even so, as long as this slit 56 is formed in the overhanging portion 55, it will still extend in the direction perpendicular to the axis.

Furthermore, the external lead wire connection structure of the present invention is particularly effective when applied to the inner coil/bobbin 50 due to its compactness, but it may of course be applied to the outer coil/bobbin. - Instead of a bobbin structure, it can also be used for transformers with a structure in which multiple coils are wound around a single coil bobbin.

<Effects of the invention> According to the present invention, all of the purposes of the invention described above can be achieved.

In other words, it does not require separate or different types of parts such as terminal pins, and has an extremely simple structure.
Ribs, etc. do not apply local stress to the external lead wire, especially its coating, and therefore the coil terminal is not affected by this stress, allowing efficient work to remove the external lead wire. and the coil terminal can be electrically and mechanically connected.

In addition, it is possible to design the structure so that the height required for the mooring part of the external lead wire is sufficiently low.
It can also be applied to thin coil bobbins.

[Brief explanation of the drawing]

FIG. 1 is an enlarged view of essential parts of a preferred embodiment of the external lead wire connection structure of the present invention, FIG. 2 is a perspective view of an inner coil bobbin to which the external lead wire connection structure shown in FIG. 1 is applied, and FIG. The figure is a plan view of the inner coil bobbin, FIG. 4 is a vertical cross-sectional view taken along the line of FIG. 3 showing the combination with the outer coil bobbin, and FIGS.
FIG. 2 is an explanatory diagram of a conventional external lead wire connection structure. In the figure, 50 is the inner coil bobbin, 53, 54
is the tsuba, 55 is the overhang, 56 is the slit, 57
58 is a mooring portion, 58 is a winding portion for the outer lead wire core wire, 59 is a holding portion for the wound core wire, 61 is an outer lead wire, 63 is the core wire, and 64 is a coil terminal.

Claims (1)

[Claims for Utility Model Registration] A projecting portion provided in the axial end of the coil bobbin around which the coil is wound, projecting in a direction perpendicular to the axis; a slit opening outward in the direction perpendicular to the axis for passing the wire in the axial direction; a winding portion of the core wire of the external lead wire rising in the axial direction from the overhanging portion on the side of the open end of the slit; An external lead wire connection structure for a coil/bobbin, comprising: an external lead wire mooring part having a holding part facing in an axis perpendicular direction from the tip of the part;