JPH07283033A - Transformer - Google Patents

Abstract

PURPOSE:To provide a high quality transformer conformable to various safety regulations, being employed in various electric apparatus, at low price. CONSTITUTION:A protrusion for supporting an outside bobbin 2 is provided, while touching the inner face at the tubular part 5 thereof and projecting into the coil part, at the coil side end of a flange part 7 having an expanded part 9 planted with the pin terminals 13 of an inside bobbin 1. An engaging recess 26 for securing the outside bobbin 2 is provided at the lower end of the expanded part 9 and a protrusion 27 being fitted in the recess 26 is provided at a part of a flange part 15 having an opening for receiving the outside bobbin 2.

Description

Detailed Description of the Invention

[0001]

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

[0002]

2. Description of the Related Art A conventional transformer is shown in FIG.
The structure was as shown in the perspective view of the transformer body. Explaining with reference to the drawings, in the transformer body, the primary coil 3 is wound around the inner bobbin 1 and the secondary coil 4 is wound around the outer bobbin 2, and the primary lead wire 22 and the secondary lead wire 23 are drawn. Each pin terminal 13 is wound and soldered through the lead groove 11. Although not shown, an iron core 24 of a magnetic material of EE type or EI type is inserted to form a transformer body.

The transformer main body is housed in a case 29, a filler 25 is injected, and a bottom plate 30 is attached to complete the transformer. The inner bobbin 1 of the fitting bobbin has a hole 6 at the center into which an iron core 24 of a magnetic material is inserted, and a cylindrical portion 5 around which a coil is wound around the hole 6. Collar portions 7 and 8 having different sizes are provided on the outer edges of both ends of the tubular portion 5. The collar portion 8 is provided with a collar end surface c that comes into surface contact with the inner surface of the collar portion 14 of the outer bobbin 2, an enlarged portion 9 is formed at the lower end portion of the collar portion 7, and the enlarged end portion 9 is wound around the lower end surface. A plurality of lead-out lead grooves 11 for guiding the primary-side lead-out lead wire 22 from the primary coil 3 and a plurality of lead-out lead holding projections 12 are provided, and the pin terminal 1
Plural 3 are planted. Further, a protruding portion that forms the engaging recess 26 is provided at the lower end of the enlarged portion 9.

A cylindrical portion 5 around which the winding wire of the outer bobbin 2 is wound.
Collar portions 14 and 15 are provided on the outer edge portions of both ends of the. An enlarged portion 16 is formed at the lower end portion of the flange portion 14, and a lead-out lead groove 11 for guiding the lead-out lead wire 23 on the secondary side from the secondary coil 4 wound around the lower end surface and a lead-out lead holding projection 12 are provided. A plurality of pin terminals 13 are provided and a plurality of pin terminals 13 are planted, and an engaging protrusion 27 having a notch 28 fitted to an engaging recess 26 provided in the enlarged portion 9 of the inner bobbin 1 is provided at the lower end of the flange 15. To provide. 10 is an insulating wall provided on the enlarged portion 9 of the inner bobbin 1, 17 is an insulating wall provided on the outer surface of the collar portion 1, 1
Reference numeral 8 is an opening portion of the outer bobbin 2, and 19 is an iron core guide collar provided on the collar portion 7 of the inner bobbin 1 and the collar portion 14 of the outer bobbin 2.

After the primary coil 3 is wound around the inner bobbin 1 of the fitting bobbin, the flange end surface c of the collar portion 8 of the inner bobbin 1 is brought into close contact with the inner surface of the collar portion 14 of the outer bobbin 2, and
The engaging convex portion 27 provided on the outer bobbin 2 is press-fitted and fixed to the engaging concave portion 26 provided at the lower end of the enlarged portion 9 of the inner bobbin 1, the outer bobbin 2 is held and fixed, and the secondary coil 4 is wound. . The lead body 22, 23 wound around the base of the pin terminal 13 is connected by soldering, and the iron core 24 of a magnetic material is incorporated into the transformer body.

[0006]

Generally, a transformer is
Depending on the circuit conditions in which the transformer is used, various safety standards are applied according to the equipment. Looking at the demand for insulation distance in video equipment as an example, the following can be seen for domestic electrical appliances.
5 mm or more, UL in North America 1.6 mm or more, European IEC
Applies an insulation distance of 6.0 mm or more.

In order to secure a larger insulation distance, the internal structure is complicated in the fitting bobbin system, and it becomes difficult to hold and fix the outer bobbin, which causes rattling of the outer bobbin when the bobbin is fitted, resulting in an insulation distance. However, as a countermeasure, the margin of the structural design becomes large and the shape of the transformer, especially the height of the transformer becomes high. Furthermore, in order to achieve both the insulating function and the holding / fixing function of the outer bobbin, the structure becomes more complicated, and highly accurate mold dimensions are required, resulting in an increase in mold cost and a decrease in mold life. It also has a big impact on the price of the transformer.

An object of the present invention is to solve the above-mentioned conventional problems and to provide a more inexpensive transformer which is compact and has a low profile.

[0009]

SUMMARY OF THE INVENTION In order to solve the above problems, the present invention provides a coil at an end of a flange portion on the coil side having an enlarged portion in which a pin terminal of an inner bobbin of a fitting bobbin is implanted. A protrusion for contacting and supporting the inner surface of the cylindrical portion of the outer bobbin so as to project to the portion and holding the outer bobbin is provided, and a recess for engagement for holding and fixing the outer bobbin is also provided at the lower end of the enlarged portion. The engaging convex part fitted in the concave part is provided in a part of the flange part forming the opening part of the outer bobbin.

[0010]

With the above structure, the contact-supporting convex portion provided so as to project to the coil portion is provided at the coil side end portion of the flange portion having the enlarged portion in which the pin terminal of the inner bobbin is implanted. , The end surface of the collar portion in which the opening portion of the outer bobbin is formed is brought into contact with the collar portion of the inner bobbin by the surface, and the contact support convex portion is Holds the inner surface of the tubular portion and holds the outer bobbin.
Further, the engaging convex portion provided on the collar portion of the outer bobbin is press-fitted into the engaging concave portion provided at the lower end of the enlarged portion where the pin terminal of the inner bobbin is implanted. The engaging convex portion is pressed by the engaging concave portion, the convex portion is press-fitted while being deformed, and after engagement, the original shape is restored and the outer bobbin is firmly fixed.

[0011]

【Example】

(Embodiment 1) An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view showing the internal structure,
2 is a perspective view showing the transformer body, and FIG. 3 is an enlarged view of a cross section showing the engaging portion.

That is, the inner bobbin 1 of the fitting bobbin is
A hole 6 into which an iron core 24 of a magnetic material is inserted is provided at the center, and a cylindrical portion 5 around which a coil is wound is formed on the outer periphery thereof. Collar portions 7 and 8 having different sizes are provided on the outer edges of both ends of the tubular portion 5. The shortest creeping distance reaching the iron core 24 along the outer periphery of the collar 8 from the coil side end surface of the outer edge of the collar 8 is 6.0 mm or more on the surface of the collar 8 that contacts the inner surface of the collar 14 of the outer bobbin 2. Thus, the annular insulating recess 21 surrounding the hole 6 into which the iron core 24 is inserted is provided.

An iron core guide collar 19 is provided on the end face of the upper end of the collar 7 which is in contact with the iron core 24, and an enlarged portion 9 is formed at the lower end of the collar 7, and the iron core at the upper end of the enlarged portion 9 is formed. An insulating wall 10 is provided on the end face in contact with 24, and a lead wire groove 11 for guiding the primary lead wire 22 from the primary coil 3 wound around the lower end face and a lead lead holding convex portion 1 are provided.
2 are provided in plurality, and a plurality of pin terminals 13 are planted.

Further, the end of the flange 7 having the enlarged portion 9 on the side of the primary coil 3 is brought into contact with the inner surface of the tubular portion 5 of the outer bobbin 2 so that the end of the collar 7 extends from the end on the coil side. A protrusion 31 for contact and support is provided along the outer circumference of which the shortest creeping distance reaching the iron core 24 is 6.0 mm or more and which projects toward the coil side.
Although not shown here, the collar portion 7 and the outer bobbin 2 are optional.
Insulating protrusions and recesses may be provided on the joint surface of the collar portion 15. A protruding engagement recess 26 is provided on the lower end surface of the enlarged portion 9.

A tubular portion 5 around which the winding wire of the outer bobbin 2 is wound.
Collar portions 14 and 15 are provided on the outer edge portions of both ends of the. An annular insulating recess 2 provided in the collar 8 of the inner bobbin 1 on the inner surface of the collar 14.
An insulative projection 20 to be fitted is provided at 1, and an enlarged portion 16 is provided at the lower end. An iron core guide collar 19 is provided on the end surface of the enlarged portion 16 in contact with the iron core 24, and a lead wire groove 11 for guiding the secondary lead wire 23 from the secondary coil 4 wound around the lower end surface. A plurality of protruding lead holding portions 12 are provided, and a plurality of pin terminals 13 are implanted.

An opening portion 18 for inserting the inner bobbin 1 is formed in the collar portion 15, and a notch 28 fitted at a lower end portion into an engaging concave portion 26 provided on a lower end surface of the enlarged portion 9 of the inner bobbin 1.
The engaging convex portion 27 having is provided. The primary coil 3 is wound around the inner bobbin 1 of the fitting bobbin, and the contact support convex portion 31 provided on the inner bobbin 1 is fitted from the opening 18 of the outer bobbin 2 to the inner surface of the tubular portion 5, and The engaging convex portion 27 provided on the flange portion 15 of the outer bobbin 2 is press-fitted into the engaging concave portion 26 provided on the lower end surface of the enlarged portion 9 of the inner bobbin 1 to hold and fix the outer bobbin 2. 2 for outer bobbin 2
The next coil 4 is wound.

Here, the primary coil 3 is moved to the outer bobbin 2,
The secondary coil 4 may be wound around the inner bobbin 1. The primary side lead wire 22 and the secondary side lead wire 23, which are wound around the respective pin terminals 13 through the lead wire groove 11, are connected by soldering, and an iron core 24 of a magnetic material of EE type or EI type is inserted. And configure the transformer body. The transformer main body is housed in the case 29, the filler 25 is injected, and the bottom plate 30 is attached to complete the transformer.

With the above structure, the bobbin can be firmly fitted and coupled, the insulation distance can be secured, and the height of the transformer can be suppressed to be low.

(Embodiment 2) Another embodiment of the present invention will be described below with reference to the drawings. FIG. 4 is an enlarged view of a cross section showing the engaging portion, and FIG. 5 is an enlarged view showing the engaging portion.
The inner bobbin 1 of the fitting bobbin according to the first embodiment has an end portion on the primary coil 3 side of the flange portion 7 in which the enlarged portion 9 is formed, and is smaller than the thickness of the flange portion 7 and parallel to the coil stacking direction. The height dimension of the contact support convex portion 31 is 0.5 mm or more higher than the height dimension a of the upper portion and the height dimension b of the lower portion, and the iron core 24 extends from the coil side end portion along the outer circumference of the collar portion 7. The contact support convex portion 31 is provided so as to project to the coil side having the shortest creepage distance reaching 6.0 mm or more.

Although not shown here, an insulating convex portion and a concave portion may be optionally provided on the joint surface between the collar portion 7 and the collar portion 15 of the outer bobbin 2. An engaging concave portion 26 for fixing is provided on the lower end surface of the enlarged portion 9 from the arbitrary position toward the coil side from the pin terminal 13 to the end surface on the primary coil 3 side. On the inner edge of the lower end of the collar 15 having the opening 18 of the outer bobbin 2,
An abutment support recess 32 is formed in the abutment support projection 31 and is fitted in an engagement recess 26 formed in the lower end surface of the enlarged portion 9 of the inner bobbin 1 at the lower end of the flange 15. An engaging convex portion 27 that abuts and engages on the surface is provided.

After the primary coil 3 is wound around the inner bobbin 1 of the fitting bobbin, the contact support convex portion 31 provided on the inner bobbin 1 is inserted from the opening 18 of the outer bobbin 2 to form the tubular portion. 5 is fitted to the inner surface of the contact bobbin 5 and the contact support recess 32, and the engaging projection 27 provided on the lower end of the flange 15 of the outer bobbin 2 is fitted to the engaging recess 26 provided on the lower end of the enlarged portion 9 of the inner bobbin 1. The outer bobbin 2 is held and fixed by press fitting.
A secondary coil 4 is wound around the outer bobbin 2.

Here, the primary coil 3 is moved to the outer bobbin 2,
The secondary coil 4 may be wound around the inner bobbin 1. The primary side lead wire 22 and the secondary side lead wire 23 are wound and solder-connected to the respective pin terminals 13 through the lead groove 11, and the EE type or EI type is used although not shown in the drawing.
The transformer main body is constructed by inserting the iron core 24 of a magnetic material made of a mold. The transformer body is housed in the case 29, the filler 25 is injected, and the bottom plate 30 is attached to complete the transformer.

With the above structure, the bobbin can be fitted and fixed more stably, and the insulation distance can be secured more reliably.

[0024]

As described above, according to the present invention, the contact support convex portion provided on the coil side end of the flange portion having the enlarged portion of the inner bobbin is fitted to the inner surface of the cylindrical portion of the outer bobbin. While holding the outer bobbin, the engaging convex portion provided on the flange portion of the outer bobbin is press-fitted into the engaging concave portion provided at the lower end of the enlarged portion of the inner bobbin, and the engaging convex portion is pressed to the engaging concave portion. The engaging projection is deformed and press-fitted to restore the original shape after the engagement, and the outer bobbin is firmly fixed to secure the insulation distance, so that the bobbin can be easily formed even if the bobbin shape becomes complicated. The outer bobbin can be firmly held and fixed to prevent rattling. Along with improving the safety of the transformer, it can be made smaller and have a lower profile. Further, since proper component clearance can be easily secured, it is possible to easily manufacture a die, reduce cost, and provide a low cost and high quality transformer.

[Brief description of drawings]

FIG. 1 is a sectional view of a transformer according to an embodiment of the present invention.

FIG. 2 is a perspective view showing a transformer body in the embodiment.

FIG. 3 is an enlarged cross-sectional view showing an engaging portion in the embodiment.

FIG. 4 is an enlarged cross-sectional view showing an engaging portion in another embodiment of the present invention.

FIG. 5 is an enlarged view showing an engaging portion according to another embodiment.

FIG. 6 is a sectional view of a transformer in a conventional example.

FIG. 7 is a perspective view showing a transformer body in a conventional example.

[Explanation of symbols]

 1 Inner bobbin 2 Outer bobbin 3 Primary coil 4 Secondary coil 5 Cylindrical part 6 Hole 7,8 Collar part 9 Enlarged part 10 Insulating wall 11 Lead-out lead groove 12 Pull-out lead holding convex part 13 Pin terminal 14, 15 Collar part 16 Enlarged Part 17 Insulating Wall 18 Opening 19 Iron Core Guide Collar 20 Insulating Convex 21 Insulating Cavity 22 Primary Side Lead Lead Wire 23 Secondary Side Lead Lead Wire 24 Iron Core 25 Filler 26 Engagement Recess 27 For Engagement Convex portion 28 Notch 29 Case 30 Bottom plate 31 Contact supporting convex portion 32 Contact supporting concave portion a Height of upper part b Height of lower part c Collar end face

Claims (2)

[Claims] 1. A flange portion having a different size is provided on each of outer edges of a cylindrical portion of an inner bobbin formed of a plastic molded product having a hole through which a magnetic material penetrates in the center, and one end of the tubular portion. A cylindrical part of the outer bobbin made of a plastic molded product in which an enlarged part is formed at the lower end of the collar part, a plurality of lead wire guide grooves are provided, a plurality of pin terminals are implanted, and the other coil is wound. Each of the two outer edges of the collar is provided with a collar portion, one of the collar portions is formed with an opening into which the inner bobbin is fitted, and the other end portion of the collar portion is provided with an enlarged portion to be provided with a plurality of lead wire guide grooves. Cylindrical terminal of the outer bobbin so as to project into the coil portion at the coil side end of the collar portion having the enlarged portion in which the pin terminal is implanted in the inner bobbin of the fitting bobbin. While forming a convex portion that contacts the inner surface of the and holds the outer bobbin, A concave portion for engagement is also provided on the lower end of the enlarged portion, and an engaging convex portion to be fitted in the concave portion is provided on a part of the flange portion having the opening portion of the outer bobbin, and the engaging portion is provided on the inner bobbin. The contact support projection is fitted to the inner surface of the tubular portion of the outer bobbin, and the engagement projection provided on the flange portion of the outer bobbin is press-fitted into the engagement recess provided at the lower end of the enlarged portion of the inner bobbin. A transformer in which an outer bobbin is held and fixed, a coil is wound around each of the fitting bobbins, and a transformer body in which a magnetic material is inserted is housed in a case made of a plastic molded product. 2. A convex portion for abutting and supporting the inner surface of the cylindrical portion of the outer bobbin so as to project to the coil portion at the coil side end portion of the flange portion having the enlarged portion in which the pin terminal of the inner bobbin is implanted. The height of the convex portion, which is parallel to the coil stacking direction, is 0.5 mm or more larger than the upper end side of the convex portion and the lower end side of the convex portion formed on the enlarged portion side where the pin terminals are implanted. At the same time, a contact support concave portion fitted to the convex portion on the lower end side is provided at the inner edge end portion of the flange portion forming the opening of the outer bobbin, and the engaging convex portion formed at the lower end portion of the flange portion is provided. 2. The transformer according to claim 1, which has a shape in which a surface of the inner bobbin abuts and engages with an engaging recess provided on a lower end surface of the enlarged portion.