JP2001076942A - Transformer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a transformer which ensures a sufficient insulation distance between the primary and secondary windings and facilitates making it small- sized and mounting. SOLUTION: This transformer comprises an insulating protrusion T4, projecting fully beyond the winding width of a primary and secondary coils C1, C2 from the winding surface of a winding part B2, the protrusion T4 is located at pin terminals P21-P23 of a first flange B3 of a bobbin B1, and a lead wire CP2 of the secondary coil C2 is led out through guide grooves R11, R13 from the vicinity of a second flange B4, engaged with protrusions S2, S3, wound by a half turn around each of guide bosses T12, T13, engaged with bosses T1, T3, laid along the protruding face of the insulating protrusion T4 of the first flange B1 and connected to the pin terminals P21, P23.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transformer in which a primary coil and a secondary coil are electrically insulated.

[0002]

2. Description of the Related Art FIG. 4 is a sectional view showing a first example of a conventional transformer. As shown in FIG. 4, the bobbin 101 has a first flange portion 103 and a second flange portion 104 formed at both ends of a winding portion 102 around which the primary coil C1 and the secondary coil C2 are wound. I have. Winding section 102
, A primary coil C1 is wound, and a lead wire CP1 of the primary coil is connected to the pin terminal 105 from near the first flange portion 103 through a groove provided in the first flange portion 103. The secondary coil C is placed on the primary coil C1.
2 is further wound, and the lead wire CP of the secondary coil C2 is drawn.
2 is connected to the pin terminal 106 from the vicinity of the first flange portion 103 through a groove provided in the first flange portion 103. An E-shaped core (not shown) is mounted on the bobbin 101 from above and below to form a predetermined magnetic circuit.

FIG. 5 is a cross-sectional view showing a second example of a conventional transformer. As shown in FIG. 5, the bobbin 111 includes:
A first flange portion 113 and a second flange portion 114 are formed at both ends of a winding portion 112 around which the primary coil C1 and the secondary coil C2 are wound. 1 for the winding part 112
The secondary coil C1 is wound, and the lead wire CP1 of the primary coil C1 is connected from the vicinity of the first flange portion 113 to the pin terminal 115 through a groove provided in the first flange portion 113. It is soldered to the printed circuit board 121. Also, the secondary coil C2 is placed on the primary coil C1.
Is wound, and the lead wire CP2 of the secondary coil C2 is
And is soldered to the printed circuit board 121 directly. An E-shaped core (not shown) is mounted on the bobbin 101 from above and below to form a predetermined magnetic circuit.

[0004]

Generally, a transformer is
Various safety standards are determined according to the application and structure, etc.
For example, in the European standard EN60 335-1, when the charged part is a lacquered or enameled winding between the charged part and another metal part via reinforced insulation, the operating voltage is 250V or less for equipment. In contrast, the insulation distance is 6.0
A creepage distance of 6.0 mm and a spatial distance of 6.0 mm are defined.

For this reason, in the conventional transformer shown in FIG. 4, the insulation distance between the primary coil C1 and the secondary coil C2, that is, the distance between the pin terminal 106 to which the primary coil C1 and the secondary coil C2 are connected. In order to secure the insulation distance and satisfy the above safety standards, the length H of the groove provided in the first flange 103 is increased. Specifically, the length H of the groove needs to be set to 8 to 10 mm in consideration of the melting of the coating due to the soldering of the lead wire CP2 of the secondary coil C2. For this reason, the height of the transformer becomes very high, which hinders downsizing of the transformer.

In the conventional transformer shown in FIG. 5, the lead CP2 of the secondary coil C2 is soldered directly to the printed circuit board 121 at a position sufficiently distant from the primary coil C1 in order to satisfy the above safety standards. Was. The work of connecting such lead wires is poor in workability, and the work of mounting the transformer has been complicated.

An object of the present invention is to provide a transformer which can ensure a sufficient insulation distance between a primary coil and a secondary coil, and which can be reduced in size and easily mounted.

[0008]

Means for Solving the Problems and Effects of the Invention (1)
1st invention The transformer which concerns on 1st invention WHEREIN: 1st and 2nd flange parts are formed in the both ends of the winding part of a bobbin, and the 1st and 2nd coil are wound around the winding part of a bobbin. A plurality of first pin terminals to which the lead wire of the first coil is connected are implanted on one side of the first flange portion, and the lead wire of the second coil is provided on the other side of the first flange portion. A plurality of second pin terminals to be connected are implanted, and an insulation distance between the first coil and the second coil satisfies a predetermined insulation distance.
An insulating protrusion projecting beyond the winding thickness of the first and second coils from the winding surface of the winding part of the bobbin has a first protrusion between the first and second coils and the second pin terminal. It is formed on the other side of the flange portion.

[0009] The transformer according to the present invention has an insulating portion formed on the other side of the first flange portion so that an insulating distance between the first coil and the second pin terminal satisfies a predetermined insulating distance. Since the projecting portion projects from the winding surface of the winding portion of the bobbin beyond the winding thickness of the first and second coils and between the first and second coils and the second pin terminal, it is used for insulation. The upper surface and side surfaces of the protruding portion can be used as insulating surfaces, and a sufficient insulating distance between the first and second coils can be secured. Further, since the upper and side surfaces of the insulating protrusion are used as insulating surfaces, it is not necessary to increase the height of the insulating protrusion, and the first flange provided with the insulating protrusion is reduced in size. Therefore, the size of the entire transformer can be reduced. Further, since the lead wire of the second coil is connected to the second pin terminal, it is not necessary to directly solder the lead wire of the second coil to a printed circuit board, and the transformer can be easily mounted. Can be.

(2) Second invention A transformer according to a second invention is the transformer according to the first invention, wherein a second pin terminal is arranged on the second pin terminal side of the second flange portion. A plurality of guide protrusions for guiding the second coil are formed between the guide protrusions by arranging the plurality of guide protrusions along the direction. The first protrusion is formed, the second protrusion is formed on the protruding surface of the insulating protrusion, and the lead wire of the second coil is drawn out from the vicinity of the second flange through the guide groove for the second coil. After being locked by the first projection and wound around the guide projection at least half a turn, the second projection is locked by the second projection and connected to the second pin terminal.

In this case, the lead wire of the second coil is drawn out from the vicinity of the second flange through the guide groove for the second coil, is locked by the first projection, and is wound around the guide projection at least half a turn. After being turned, it is locked to the second convex portion and connected to the second pin terminal, so that the second coil can be easily pulled out and drawn, and the transformer can be easily manufactured.

(3) Third invention A transformer according to a third invention is the transformer according to the first or second invention, wherein a magnetic core is mounted on the bobbin, and the second pin terminal is connected to the second pin terminal. The insulation distance between the first coil and the second pin terminal excluding the non-insulation distance of the lead wire of the second coil due to the soldering of the lead wire of the coil to the second pin terminal is equal to the magnetic core and the second pin terminal. Are implanted in the first flange portion so as to be substantially equal to the insulation distance between the pin terminals.

In this case, between the first coil and the second pin terminal except for the non-insulated distance of the lead of the second coil by soldering the lead of the second coil to the second pin terminal. The second pin terminal is implanted in the first flange portion so that the insulation distance between the first and second pin terminals is substantially equal to the insulation distance between the magnetic core and the second pin terminal.
In consideration of shortening of the insulation distance between the first coil and the second pin terminal, the size of the insulating protrusion is adjusted to the insulation distance between the first coil and the second pin terminal and the magnetic core. The required insulation distance between the second pin terminal and the second pin terminal can be minimized, and a smaller transformer can be realized.

(4) Fourth Invention A transformer according to a fourth invention is the transformer according to the third invention, wherein the first coil is a primary coil, and the first coil is a first coil. A plurality of first coil guide grooves for pulling out the first coil are arranged in the pin terminal side along the direction in which the first pin terminals are arranged, and the lead wire of the primary coil is connected to the first flange portion. It is pulled out from the vicinity through the first coil guide groove and connected to the first pin terminal. The second coil is a secondary coil composed of a three-layer insulated wire, and is connected between the primary coil and the secondary coil. Has a creepage distance and a space distance of not less than 6.0 mm, and a creepage distance and a space distance between the magnetic core and the secondary coil of not less than 6.0 mm.

In this case, the lead wire of the primary coil is connected to the first coil.
Pull out from the vicinity of the flange of the first through the guide groove
, The lead wire of the primary coil can be easily connected to the first pin terminal, and a three-layer insulated wire is used as the secondary coil.
Since the creepage distance and the space distance between the primary coil and the magnetic core and the secondary coil are each 6.0 mm or more, it is possible to realize a small transformer that satisfies the safety standards stipulated in the European standard EN60335-1, etc. it can.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a transformer according to an embodiment of the present invention will be described with reference to the drawings. FIG.
3 is a perspective view of a transformer according to an embodiment of the present invention, FIG. 2 is a front view of the transformer shown in FIG.
FIG. 3 is a sectional view taken along line AA ′ of the transformer illustrated in FIG. 2. The transformer of the present invention is a small transformer that is suitably used for various power supply devices, chargers, and the like.

The transformer shown in FIGS.
1, primary coil C1, secondary coil C2, E-type core EC
1, EC2 and pin terminals P11-P15, P21-P
23.

The bobbin B1 includes a winding portion B2 around which the primary coil C1 and the secondary coil C2 are wound, a first flange portion B3 integrally formed at a lower end of the winding portion B2, and a winding portion. And a second flange portion B4 formed integrally with the upper end of B2.

The pin terminals P21 to P21 of the first flange portion B3
The P23 side is formed on an insulating protruding portion T4 projecting sufficiently beyond the winding thickness of the primary coil C1 and the secondary coil C2 from the winding surface of the winding portion B2, and on a protruding surface of the insulating protruding portion T4. And three convex portions T1 to T3. The width of the insulating protrusion T4 in the arrangement direction of the pin terminals P21 to P23 is:
Exceeding the width of the secondary coil C2 in the same direction, in the present embodiment, it substantially matches the width of the E-shaped core EC2 in the same direction. Therefore, the pin terminals P21 to P21 of the first flange portion B3
On the 23 side, there is not formed a wiring groove for a lead wire unlike a conventional transformer. Three pin terminals P21 to P2 are provided on the lower surface of the insulating protrusion T4 of the first flange B3.
3 are implanted by press fitting or integral molding.

The shape of the insulating protruding portion is not particularly limited to the shape shown in the drawing. If the insulating distance described below is satisfied, the ribs, grooves, and the like may be appropriately formed in consideration of resin sinking during bobbin molding. It may be provided. In addition, the shape and size of the protrusion formed on the insulating protrusion are not particularly limited to the shape and size shown in the drawing, as long as the secondary coil C2 can be easily routed. It may be in shape and size.

The pin terminals P21 to P21 of the second flange portion B4
On the P23 side, four guide protrusions T11 to T14 are arranged in line along the arrangement direction of the pin terminals P21 to P23,
The guide protrusions T11 to T14 protrude beyond the winding thickness of the primary coil C1 and the secondary coil C2. Guide grooves R11 to R13 for arranging the lead wire CP2 of the secondary coil C2 are formed between the guide protrusions T11 to T14. Protrusions S1 to S4 are formed on the upper surfaces of the guide protrusions T11 to T14 so as to wind and lock the lead wire CP2 of the secondary coil C2 at least half a turn.

The shape and number of the guide protrusions are not particularly limited to the shapes and numbers shown in the drawings, and a guide groove can be formed so that the secondary coil C2 can be easily pulled out.
Other shapes and numbers may be used as long as the configuration enables easy routing of the next coil C2. In addition, the shape and size of the projection formed on the guide projection are not particularly limited to the shapes and sizes shown in the drawing, as long as the secondary coil C2 can be easily routed. It may be in shape and size.

The pin terminals P11 to P11 of the first flange portion B3
On the P15 side, like the conventional transformer, the primary coil C
A guide groove for wiring one lead line CP1 is formed, and the bottom surface of this guide groove is flush with the winding surface of the winding part B2. On the lower surface of the first flange portion B3, 3
The pin terminals P21 to P23 are implanted by press-fitting or integral molding. Further, like the conventional transformer, the primary coil C1 and the secondary coil C2 are provided on the pin terminals P11 to P15 side of the second flange portion B4 in order to facilitate the winding of the primary coil C1 and the secondary coil C2. The protrusion is provided beyond the winding thickness of the coil C2.

E-shaped cores EC1 and EC2, which are magnetic cores from above and below, are mounted on the bobbin B1 to form a predetermined magnetic circuit. The shape of the core is not particularly limited to this example, and a core having another shape such as a combination of an E-shaped core and an I-shaped core may be used.

As the primary coil C1, for example, an electric wire such as an enameled wire is used. The primary coil C1 has a winding portion B
2 and the lead wires CP1 at both ends are connected to the pin terminals P1.
It is pulled out from the vicinity of the first flange portion B3 on the side of 1 to P15, passes through the groove, and is connected to the pin terminals P12 and P14 by soldering.

The secondary coil C2 is made of a three-layer insulated wire whose insulation is regarded as reinforced insulation. For example, a Furukawa Electric three-layer insulated wire Furukawatex (TEX-E) can be used. The secondary coil C2 is further wound on the primary coil C1. One of the lead lines CP2 is pulled out from the vicinity of the second flange portion B4 through the guide groove R11, is locked by the convex portion S2, is wound around the guide protrusion T12 by half a turn, and is then locked by the convex portion T1. The first flange portion B3 is wired along the protruding surface of the insulating protruding portion T4, and is connected to the pin terminal P21 by soldering. The other end of the lead wire CP2 is pulled out from the vicinity of the second flange portion B4 through the guide groove R12, locked by the convex portion S3, wound around the guide protrusion T13 by half a turn, and then locked by the convex portion T3. Is wired along the protruding surface of the insulating protruding portion T4 of the first flange portion B3, and is soldered to the pin terminal P23.
Connected to.

The wiring paths of the primary coil and the secondary coil are not particularly limited to the above example, and other wiring paths via other guide grooves or the like may be used as long as wiring is easy. The number of pin terminals and the like are not particularly limited to the above examples.
In addition, from the viewpoint of assemblability and the like, an insulating tape or the like may be added between the primary coil and the secondary coil, on the surface of the secondary coil, and the like. Also, the numbers of the primary coils and the secondary coils are not particularly limited to the above example, and a plurality of primary coils and secondary coils may be used.

In the present embodiment configured as described above, the shortest insulation distance between the primary coil C1 and the secondary coil C2, that is, the pin terminal to which the lead CP2 of the primary coil C1 and the secondary coil C2 is connected. As shown in FIG. 3, the insulation distance (creeping distance and space distance) from P21 and P23 is as follows.
If the coating of the lead wire CP2 of the coil C2 is melted by the distance B by soldering, the distance becomes the distance A. Therefore, the upper surface and the outer side surface of the insulating protrusion T4 can be used as the insulation distance A, and the insulation distance between the primary coil C1 and the pin terminals P21 and P23 can be sufficiently ensured. Specifically, the distance B is set to 3 mm or more, and the insulation distance A is set to 6.5 mm or more.

The shortest insulation distance between the E-shaped cores EC1 and EC2 and the secondary coil C2, that is, the pin terminal P to which the lead-out line CP2 of the E-shaped core EC2 and the secondary coil C2 is connected.
The insulation distance (creepage distance and space distance) between P21 and P23 is the distance C shown in FIG. Therefore, the inner side surface and the lower surface of the insulating protrusion T4 can be used as the insulating distance C, and the E-shaped core EC2 and the pin terminal P2 can be used.
1, an insulation distance from P23 can be sufficiently ensured. Specifically, the insulation distance C is set to 6.5 mm or more.

In the present embodiment, the insulation distances A and C
In both cases, the positions of the pin terminals P21 to P23 are set such that the insulation distance A and the insulation distance C are approximately equal to or greater than 6.0 mm. Therefore, the size of the insulating protrusion T4 can be reduced to the minimum necessary size in consideration of the shortening of the insulation distance (distance B) due to soldering, and the transformer can be further reduced in size. Become.

Further, in the present embodiment, as described above, a three-layer insulated wire serving as reinforced insulation is used as the secondary coil C2, and the primary coil C1 and the E-shaped core EC2 are connected to the pin terminals P21 and P23. Creepage distance and clearance distance of 6.0 mm or more, respectively.
0 335-1 etc. can be satisfied.

In this embodiment, the first flange portion on the pin terminal side of the secondary coil is provided with an insulating protruding portion. An insulating protrusion or the like may be provided on the first flange portion on the terminal side, or an insulating protrusion or the like may be provided on both sides of the first flange portion. In these cases, the same effect as described above can be obtained. Obtainable.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a configuration of a transformer according to an embodiment of the present invention.

FIG. 2 is a front view of the transformer shown in FIG.

FIG. 3 is a sectional view taken along line AA ′ of the transformer shown in FIG. 2;

FIG. 4 is a cross-sectional view showing a first example of a conventional transformer.

FIG. 5 is a cross-sectional view showing a second example of a conventional transformer.

[Explanation of symbols]

 B1 Bobbin B2 Winding B3 First Flange B4 Second Flange T1 to T3 Convex T4 Insulation Projection T11 to T14 Guide Projection S1 to S4 Projection R11 to R13 Guide Groove C1 Primary Coil C2 Secondary coil CP1 Lead wire of primary coil CP2 Lead wire of secondary coil P11 to P15, P21 to P23 Pin terminals

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01F 31/00 H

Claims (4)

[Claims] A first and a second terminal are provided at both ends of a winding portion of a bobbin.
Are formed, a first coil and a second coil are wound around a winding portion of the bobbin, and a lead wire of the first coil is connected to one side of the first flange portion. A first pin terminal is implanted, and a plurality of second pin terminals to which a lead wire of the second coil is connected are implanted on the other side of the first flange portion. An insulation projecting beyond the winding thickness of the first and second coils from the winding surface of the winding portion of the bobbin so that the insulation distance between the second coil and the second coil satisfies a predetermined insulation distance. A transformer, wherein a protrusion is formed on the other side of the first flange portion between the first and second coils and the second pin terminal. 2. The second coil, wherein a plurality of guide protruding portions are arranged in a row along the direction in which the second pin terminals are arranged on the second pin terminal side of the second flange portion. A plurality of second coil guide grooves for extracting the second protrusion are formed between the guide protrusions, a first protrusion is formed on the guide protrusion, and a second protrusion is formed on a protrusion surface of the insulation protrusion. The lead of the second coil is drawn out from the vicinity of the second flange through the guide groove for the second coil, and is locked by the first protrusion to guide the lead. 2. The transformer according to claim 1, wherein after being wound at least half a round around the projecting portion, the transformer is locked by the second projecting portion and connected to the second pin terminal. 3. 3. The bobbin is provided with a magnetic core,
The pin terminals of the first coil and the second pin exclude the non-insulating distance of the lead wire of the second coil by soldering the lead wire of the second coil to the second pin terminal. The insulation distance between the magnetic core and the second
So that it is almost equal to the insulation distance between
The transformer according to claim 2, wherein the transformer is implanted in the first flange portion. 4. The first coil is a primary coil, and the first coil is arranged on the first pin terminal side of the first flange portion along a direction in which the first pin terminals are arranged. A plurality of first coil guide grooves for pulling out the first coil are arranged in line, and a lead wire of the primary coil is drawn out from the vicinity of the first flange portion through the first coil guide groove, and the first coil guide groove is drawn. The second coil is connected to a pin terminal, and the second coil is a secondary coil made of a three-layer insulated wire, and a creepage distance and a space distance between the primary coil and the secondary coil are 6.0 mm or more. 4. The transformer according to claim 3, wherein a creepage distance and a space distance between the magnetic core and the secondary coil are 6.0 mm or more.