JP3438201B2 - Coil bobbin - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coil bobbin of a small transformer with a cover used as, for example, a power transformer for audio.

[0002]

2. Description of the Related Art Conventionally, as a coil bobbin for a transformer of this type, there is JP-A-11-297535. 8 (a) and 8 (b) show an example thereof. In order to secure an insulation distance between the primary winding 31 and the secondary winding 32, resin is provided on the primary winding 31 side of the coil bobbin 30. There is a case in which a box-shaped insulating cover 33 made of metal is attached from above. This insulating cover 33 has a coil bobbin 3
In order to make it easy to cover the terminal portion 34 of
And a portion that covers the terminal portion 34 can be easily bent upward.

FIG. 9 shows another conventional example. In this conventional example, an insulating cover 4 made of a molded product or insulating paper is attached to the coil bobbin 40 on the primary winding side in the direction indicated by the arrow.

[0004]

Today, there is intense cost competition for products of this type, and it is always an issue how to reduce material costs. Another issue is how to improve the assemblability from the viewpoint of productivity and labor saving.

Under such a background, FIG.
In the conventional example shown in (a) and (b), there is a drawback in that the manufacturing of the insulating cover 33 is expensive and the cost cannot be reduced. Further, when the insulating cover 33 is attached to the coil bobbin 30, there is a drawback that the front part of the notch 35 needs to be bent upward, and the assembling property is deteriorated accordingly.

Further, the conventional example of FIG. 9 is a typical example, but according to this structure, the insulating cover 41 can be attached only in the direction of the arrow, and in some cases, it must be fixed by using a tape or the like. However, there are disadvantages that the number of partial points is increased and the workability is complicated accordingly.

The present invention has been proposed in view of the above circumstances, and an object thereof is to make the shape of the insulating cover simple and to assemble easily, suitable for mass production, and cost-effective coil bobbin. To provide.

[0008]

The present invention is directed to a winding drum portion 3
And an upper flange 4 and a lower flange 5 are formed on both ends of the winding barrel 3, respectively, and an intermediate flange 6 is formed between the upper flange 4 and the lower flange 5.
In the coil bobbin 1 in which the secondary winding area is formed,
Insulating cover mounting portions 9 and 10 for inserting the upper plate of the insulating cover having a substantially U-shaped cross section are formed on the upper flange 4, and an insulating cover for inserting the lower plate of the groove-shaped insulating cover is formed on the intermediate flange 6. The insert 12 is formed and the insulating cover is formed.
The ceiling surfaces of the mounting portions 9 and 10 and the insulating cover insertion portion 12
Protrusions 11 and 1 for press-fitting the upper and lower plates of the insulating cover on the ceiling surface
1a is formed to achieve the above object. In addition, the outer end portions of the flange 4 on the front surface side and the rear surface side.
The stepped portion 7 is formed on the concave portion 8 and the insulating cover is formed.
The bar attachments 9 and 10 are attached to the front and back ends, respectively.
A pair of insulating cover mounting portions 9, each of which is formed one by one,
The base portion 9a of the insulating cover attaching portion 9 on one end side of the
Insulating cover mounting portion provided on the step portion 7 on the other end side
The base 10a of 10 is positioned for the insulating cover that has been press-fitted.
It is characterized in that it is provided on the concave step portion 8 for the purpose . Furthermore, the insulating cover insertion parts 9 and 10 can insert an insulating cover from the front or the side.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, the insulating cover 2 is
Compared to the one in FIG. 8, it has a simple shape that is almost U-shaped,
The cost is reduced accordingly. In addition, the coil bobbin 1 is formed with the insulating cover attaching portions 9 and 10 having the projections 11 and 11a for preventing the insulating cover 2 from falling off, and the insulating cover 2 is simply inserted without using a fixing tape or the like. It can be easily fixed with, and the assemblability is good. Further, the insulating cover 2 is not only attached from the front side of the coil bobbin 1, but also after the core is attached, the insulating cover 2 can be easily inserted by inserting it from the lateral direction, thereby providing freedom in assembly.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a perspective view of an essential part of the present invention, and FIG. 2 is A in FIG.
It is an expanded sectional view of the A-line.

In the figure, reference numeral 1 is a coil bobbin formed of an insulating resin molded product, 2 is an insulating cover having a substantially U-shaped cross section, and the insulating cover 2 is a horizontally long rectangular main body 2a and the upper and lower portions thereof are perpendicular to each other. The upper plate 2b and the lower plate 2c are bent and formed to face each other.

As is well known, the coil bobbin 1 has a hollow cylindrical winding body portion 3 into which a center leg (not shown) of a core is inserted.
And an upper flange 4 and a lower flange 5 respectively formed on both ends of the winding drum portion 3, and an intermediate flange 6 formed between them. The line area 3a and the secondary winding area 3b are defined.

A step 4a is formed on the upper surface of the outer end of the upper flange 4.
A recessed step portion 4b whose upper surface is lowered downward by one step is formed, and substantially L-shaped insulating cover attaching portions 9 and 10 are formed at both ends of the step portion 4a.

The base portion 9a of the insulating cover attaching portion 9 on the one end side shown on the right side in FIG. 1 is located above the step portion 7, that is, the base portion 9a is formed at the outer end portion of the upper surface of the upper flange 4. Further, the insulating cover attaching portion 10 on the other end side shown on the left side is formed outside the step portion 7, that is, on the concave step portion 8.

This is because when the insulating cover 2 is inserted laterally in the direction of the arrow, that is, in the B direction, one end of the upper plate 2b of the insulating cover 2 is attached to the base 1 of the other insulating cover mounting portion 10.
This is because it is possible to easily position by abutting on 0a. When the positioning member is formed by a separate member, the other insulating cover mounting portion 10 may be provided on the stepped portion 7 like the one insulating cover mounting portion 9.

On the inner surfaces of the insulating cover mounting portions 9 and 10, projections 11 each having a substantially inverted triangular cross section are formed. The protrusion 11 is provided on the upper plate 2b of the insulating cover 2,
And presses the upper plate 2 of the insulating cover 2
b is press-fitted between the inner surfaces of the insulating cover attaching portions 9 and 10 and the top of the concave step portion 8 to be securely fixed.

An approximately U-shaped groove-shaped insulating cover insertion portion 12 is formed at approximately the center of the intermediate flange 6.
The lower plate 2c of the insulating cover 2 is inserted through the insulating cover insertion portion 12.

In this case, a projection 11a for pressing and securely fixing the upper surface of the lower plate 2c inserted through the ceiling surface of the insulating cover insertion portion 12 is also formed. This protrusion 11a
Is formed entirely along the length direction of the ceiling surface, but may be formed partially.

FIG. 3 is a plan view of the coil bobbin 1 of the present invention,
FIG. 4 shows a front view.

As shown in FIGS. 3 and 4, the insulating cover attaching portions 9 and 10 are formed in pairs at the front and rear ends of the upper flange 4, respectively.

Ribs 14 and 15 for positioning a core (not shown) are formed on both sides of the window 13 in the winding barrel 3. Inner side surface 9 of each insulating cover mounting portion 9, 10
b and 10b are formed almost on the extension lines of the ribs 14 and 15 and also serve as core positioning, so that the core is firmly positioned,
Can be fixed.

A lead-out wire (not shown) such as a winding start and winding end of the primary winding wound around the winding barrel 3 at an appropriate position on the left side of the upper flange 4 is drawn out to the outside. A plurality of grooves 16 are formed.

A plurality of columnar projections 17 for appropriately tying the lead wire are provided at appropriate positions in the vicinity of the drawing groove 16.

A reinforcing rib 18 is formed on the right side of the upper flange 4. The reinforcing rib 18 is tapered outward from the outer surface of the rib 14.

FIG. 5 shows a bottom view of the coil bobbin 1, and FIG. 6 shows a left side view.

Ribs 19 and 2 for positioning and fixing a core (not shown) at both ends of the window 13 on the lower flange 5 side.
0 is formed.

Further, a plurality of lead-out grooves 21 for leading the lead wire of the secondary winding (not shown) are formed at an appropriate position on the left side portion of the lower flange 5, and a pin terminal 22 is provided in the vicinity thereof. Has been. The projections 23 provided on both sides
Is surface mount.

A reinforcing rib 24 is formed on the right side portion on the opposite side. In addition, a notch 2 with a substantially U shape is formed at the outer end.
5 is formed.

FIG. 7 shows a coil bobbin 1 on the winding drum portion 3
The secondary and secondary windings 26 and 27 are respectively wound, and the core 2
8 is a schematic side sectional view showing a state in which 8 is incorporated.

The upper plate 2b and the lower plate 2c of the insulating cover 2 shown in FIG. 1 are assembled with the core 28, and then, from the front side in the vertical direction of the paper in FIG. 7, that is, the B side in FIG. The outer surface of the primary winding 26 should be covered with the insulating cover body 2a if it is press-fitted between the mounting portions 9 and 10 and the upper surface of the concave step portion 8 of the upper flange 4 and into the insulating cover insertion portion 12 of the intermediate flange 6. The primary winding and the secondary winding 2
A small transformer with a cover in which the insulating distance between 6, 27 and the core 28 is secured by the insulating cover 2 is configured.

According to this small transformer, the insulating cover 2
Is securely held by the projections 11 and 11a and does not come out. Therefore, it is not necessary to fix it with tape or the like.

It should be noted that the insulating cover 2 can be pressed in from the front, that is, the direction indicated by the arrow C in FIG. 1 before the core 28 is assembled, and in the present invention, the assembling procedure has a degree of freedom. There is.

[0033]

As described above, according to the present invention, since the insulating cover attaching portions 9 and 10 are formed on the upper flange 4 and the groove-like insulating cover inserting portion 12 is formed on the intermediate flange 6, the insulating cover is easily insulated. The cover 2 can be attached and workability is good.

Further, the projections 11 and 11a for pressing are provided on the ceiling surfaces of the insulating cover attaching portions 9 and 10 and the insulating cover inserting portion 12.
Since the press-fitted insulating cover 2 does not come out, the labor of fixing the insulating cover 2 by using a separate fixing means such as an adhesive or a tape can be reduced, and the material cost is also reduced. It can be reduced, suitable for mass production, and can contribute to cost reduction.

Further, a pair of insulating cover attaching portions 9 and 10 are provided, and a step portion 7 is formed on the upper flange 4 to form a concave step portion 8. The base portion 9 of the insulating cover attaching portion 9 on one end side is formed.
a is formed on the step portion 7, and the insulating cover attachment portion 1 on the other end side is formed.
Since the base portion 10a of 0 is provided on the concave step portion 8, when the insulating cover 2 is press-fitted from the one end side, the inner surface of the base portion 10a of the insulating cover mounting portion 10 on the other end side serves as a stopper.
The insulating cover 2 can be positioned and attached at a predetermined position.

Further, the insulating cover 2 can be attached to the coil bobbin 1 from either the front side or the side thereof, so that the assembling procedure has a degree of freedom.

[Brief description of drawings]

FIG. 1 is a perspective view of an essential part of an embodiment of the present invention.

FIG. 2 is a sectional view taken along the line A-A ′ in FIG.

FIG. 3 is a plan view of a coil bobbin according to an embodiment of the present invention.

FIG. 4 is a front view of the same.

FIG. 5 is a bottom view of the same.

FIG. 6 is a left side view of the same.

FIG. 7 is a schematic partial cross-sectional view in an assembled state.

FIG. 8A is a side view of a conventional example before assembly, and FIG.
Shows a side view after assembly.

FIG. 9 shows a schematic perspective view of another conventional example.

[Explanation of symbols]

1 coil bobbin 2 Insulation cover 2a body 2b Upper plate 2c Lower plate 3 winding body 3a Primary winding part 3b Secondary winding part 4 Upper flange 5 Lower flange 6 Intermediate flange 7 steps 8 concave steps 9, 10 Insulation cover mounting part 11, 11a protrusion 12 Insulation cover insertion part 13 windows 14, 15 ribs 16 Leader 17 Projection 18 Reinforcing ribs 19, 20 ribs 21 Drawout groove 22 pin terminal 23 Projection 24 Reinforcing ribs 25 notches 26 Primary winding 27 Secondary winding 28 cores

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Claims (3)

(57) [Claims] 1. A winding barrel (3), an upper flange (4) and a lower flange (5) formed at both ends of the winding barrel (3), and the upper flange (4) and the lower flange. Intermediate flange (6) is formed between (5) and
In a coil bobbin (1) in which a secondary winding region is defined and formed, insulating cover attaching portions (9), (10) for inserting an upper plate of an insulating cover having a substantially U-shaped cross section on the upper flange (4).
And an insulating cover insertion portion (12) for inserting a lower plate of a groove-shaped insulating cover in the intermediate flange (6), and the ceiling surface of the insulating cover attachment portions (9), (10) ,
An insulating cover is attached to the ceiling surface of the insulating cover insertion portion (12).
A coil bobbin formed with protrusions (11) and (11a) for press-fitting an upper plate and a lower plate . 2. A front side of the flange (4) and
A step (7) is formed at the outer end on the back side to form a concave step (8).
And the insulating cover mounting portions (9) and (10) are formed
One pair is formed on each of the front and back sides.
One of the pair of insulating cover mounting parts (9) and (10)
The base portion (9a) of the insulating cover attaching portion (9) on the end side is the above-mentioned.
Insulation cover attachment part provided on the step (7) and on the other end side
The base (10a) of (10) is an insulation cover that has been press-fitted.
Provided on the concave step (8) for positioning
1. The coil bobbin described in 1. 3. Insulating cover insertion parts (9), (10) are
Claim that the insulating cover can be inserted from the front or side of
The coil bobbin according to Item 1.