WO2012036371A1

WO2012036371A1 - Transformer for adapters

Info

Publication number: WO2012036371A1
Application number: PCT/KR2011/004052
Authority: WO
Inventors: Hyun Jun Kim; Dae Young Youn; Hyun Soo Park; Eun Min Jeon
Original assignee: Smart Power Solutions, Inc.
Priority date: 2010-09-14
Filing date: 2011-06-02
Publication date: 2012-03-22
Also published as: KR20120028117A; KR101168323B1

Abstract

A transformer for adapters, which can be mounted on a PCB by an automatic process and can produce slim adapters. The transformer includes a bobbin having a hollow body provided with upper and lower flanges formed around upper and lower ends of the hollow body, a pin guide fitted over a lead pin bent from a side of the upper flange toward the lower flange and controlling the depth to which the lead pin is inserted when the lead pin is mounted to the PCB; and a subsidiary guide assembled with a side of the lower flange and supporting a side of the transformer when the lead pin is mounted to the PCB.

Description

TRANSFORMER FOR ADAPTERS

The present invention relates, in general, to transformers and, more particularly, to a transformer for adapters, which is mounted on a PCB for adapters and can produce a slim adapter.

Generally, a transformer is mounted on a PCB for electronic products and receives a low voltage and changes it to a high voltage, and applies the high voltage to an electronic circuit or, on the contrary, receives a high voltage and changes it to a low voltage.

To produce a transformer in the related art, a coil is wound around the outer circumferential surface of a bobbin made of a heat-resisting and insulating resin and, thereafter, is covered with an insulating film, and a ferrite core is inserted into the coil-wound bobbin and fixed thereto.

Fig. 1 is a view illustrating a PCB on which a conventional transformer is mounted.

As shown in Fig. 1, the conventional transformer 3 is arranged on the PCB 1 along with a variety of electronic devices 5 in a planar arrangement and is soldered thereto.

Generally, the transformer may be the biggest one of a plurality of electronic devices mounted on the PCB, so that the size of the transformer determines the size of a product in which the PCB is installed.

In the related art, the transformer 3 and the related electronic devices 5 are arranged on the PCB 1 in the planar arrangement described above, which increases the size of a product, such as an adapter, so that it is almost impossible to realize smallness and slimness of the product.

Another problem of the conventional transformer resides in that the transformer is mounted on a PCB by a manual soldering method, thus reducing the productivity and causing uneven soldering quality.

Accordingly, the present invention has been made keeping in mind the above problems occurring in the related art, and is intended to provide a transformer for adapters, which can be mounted on a PCB by an automated method and can produce a slim adapter.

The technical problems to be solved by the present invention are not limited to the above-mentioned problems, and those skilled in the art will glean from the following description that there are other technical problems which have not been described in this document.

In an aspect, the present invention provides a transformer for adapters, comprising: a bobbin including a hollow body having upper and lower flanges formed around upper and lower ends of the hollow body; a pin guide fitted over a lead pin bent from a side of the upper flange toward the lower flange and controlling a depth to which the lead pin is inserted when the lead pin is mounted to a PCB; and a subsidiary guide assembled with a side of the lower flange and supporting a side of the transformer when the lead pin is mounted to the PCB.

Described in detail, the pin guide may comprise: a guide body having a pin insert hole into which the lead pin is inserted; a locking block extending upwards from an end of the guide body and assembled with a pin holder; and a position control part extending downwards from a predetermined portion of the guide body and controlling the depth to which the lead pin is inserted.

Further, an end of the position control part may come into contact with a surface of the PCB when the lead pin is mounted to the PCB.

The subsidiary guide may comprise: a locking block assembled with the guide holder by a interference fitting method; and a support arm horizontally extending from an upper end of the locking block and coming into contact with a surface of the PCB and thereby supporting the side of the transformer when the lead pin is mounted to the PCB.

The transformer may be mounted to a through hole of the PCB and may be mounted on the PCB by a wave soldering method.

In another aspect, the present invention provides a transformer for adapters, a bobbin including a hollow body having upper and lower flanges formed around upper and lower ends of the hollow body; a pin holder provided at a side of the upper flange and having a lead pin bent in the direction of the lower flange; and a pin guide assembled with the pin holder by being fitted over the lead pin and controlling a depth to which the lead pin is inserted when the lead pin is mounted to a PCB (printed circuit board).

Additionally, the transformer may further comprise: a guide holder protruding from another side of the lower flange; and a subsidiary guide assembled with the guide holder and supporting a side of the transformer when the lead pin is mounted to the PCB.

Described in detail, the pin guide may comprise: a guide body having a pin insert hole into which the lead pin is inserted; a locking block extending upwards from an end of the guide body and assembled with the pin holder; and a position control part extending downwards from a predetermined portion of the guide body and controlling the depth to which the lead pin is inserted.

Further, the subsidiary guide comprises: a locking block assembled with the guide holder by a interference fitting method and controlling a horizontal height of the transformer according to an assembled position thereof when the lead pin is mounted to the PCB; and a support arm horizontally extending from an upper end of the locking block and coming into contact with a surface of the PCB and thereby supporting the side of the transformer when the lead pin is mounted to the PCB.

As described above, the present invention uses both a pin guide and a subsidiary guide so that the present invention can allow a wave soldering method to be used in the PCB through-hole mounting, such as the conventional DIP mounting, and can realize slimness of adapters due to the PCB through-hole mounting.

Further, the present invention using both the pin guide and the subsidiary guide can control the depth to which a transformer is inserted into the through hole of a PCB and thereby control the degree of slimness of a product without requiring changes to the basic shape of the transformer so that the structure of the desired slim product can be realized.

Because the present invention uses both the pin guide and the subsidiary guide as described above, an automated method, such as a wave soldering method, can be adapted to the PCB through-hole mounting, thus increasing the productivity and assembly quality of products.

Fig. 1 is a view illustrating a PCB on which a conventional transformer is mounted;

Figs. 2 and 3 are an exploded perspective view and an assembled perspective view illustrating a transformer for adapters according to an embodiment of the present invention;

Fig. 4 is a perspective view illustrating the construction of a pin guide according to the embodiment of the present invention shown in Fig. 2;

Fig. 5 is a perspective view illustrating the construction of a subsidiary guide according to the embodiment of the present invention shown in Fig. 2;

Figs. 6 through 9 are views illustrating a method of assembling the transformer for adapters according to the embodiment of the present invention; and

Figs. 10 and 11 are an exploded perspective view illustrating the transformer according to the present invention, which is mounted on a PCB, and a sectional view of the transformer which has been mounted on the PCB, respectively.

Hereinbelow, a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

Wherever possible, the same reference numerals will be used throughout the drawings and the description to refer to the same or like parts.

Further, it is to be noted that, when the functions and structures of conventional elements and the detailed description of elements related with the present invention may make the gist of the present invention unclear, the detailed description of those elements will be omitted.

Figs. 2 and 3 are an exploded perspective view and an assembled perspective view illustrating a transformer for adapters according to an embodiment of the present invention.

As shown in the drawings, the transformer 100 includes a bobbin 110, a pin holder 120,

cores

140 and 145, a pin guide 150, a guide holder 160, and a subsidiary guide 170.

The bobbin 110 includes a hollow body 111 having an upper flange 113 and a lower flange 115, which are formed around the upper and lower ends of the hollow body 111, with a coil (not shown) wound around the hollow body 111.

The bobbin 110 is made of an insulating material and is fabricated in the form of an I-shaped hollow structure having a central bore.

The pin holder 120 is provided at a side of the upper flange 113, and a plurality of lead pins 130 are mounted to the pin holder 120 and are bent downwards to the lower flange 115 at angles of 90 degrees.

In other words, each of the lead pins 130 comes off of a side surface of the pin holder 120 and is bent downwards to the lower flange 115, thus forming an L-shape.

The lead pins 130 are also connected to the coil wound around the bobbin 110.

The

cores

140 and 145 include an E-shaped first core 140 and an I-shaped second core 145 having a shape coinciding with the shape of the first core 140.

Each of the two

cores

140 and 145 is made of a ferrite material and, when an alternating current is applied to the coil, the two

cores

140 and 145 form a magnetic path.

The first core 140 includes a base part 141, a magnetic path forming part 142 extending from the base part 141 toward the second core 145 and forming the magnetic path, and a bobbin holding part 143 inserted into the central bore of the bobbin 110.

The bobbin holding part 143 may function to form the magnetic path along with the magnetic path forming part 142.

The magnetic path forming part 142 protrudes upwards from opposite edges of the base part 141 to a predetermined height.

The bobbin holding part 143 is a cylindrical part, which protrudes upwards from the central portion of the base part 141 toward the second core 145 by a predetermined height.

The second core 145 may have only a flat base part.

However, it should be understood that the second core 145 may be designed to have both a magnetic path forming part and a bobbin holding part in the same manner as those described in the first core 140 when necessary.

In this case, the core may be selected from EE-type cores.

The pin guide 150 is securely assembled with the pin holder 120 by inserting the lead pins 130 into respective pin insert holes of the pin guide 150.

When the lead pins 130 are mounted to the PCB, the depth to which the lead pins 130 are inserted into the pin insert holes of the pin guide 150 can be controlled.

As shown in Fig. 4, the pin guide 150 includes a guide body 151, a locking block 155 and a position control part 159.

The guide body 151 is provided with a plurality of pin insert holes 152, which are formed in the guide body 151 at regular intervals and receive the respective lead pins 130 therein.

The locking block 155 extends upwards from each end of the guide body 151 and engages with an associated locking protrusion 121 provided on each end surface of the pin holder 120.

The position control part 159 extends downwards from a predetermined portion of the guide body 151 and controls the depth to which the lead pins 130 are inserted when the lead pins 130 are mounted to the PCB.

In the embodiment, one or more position control parts 159 are formed on the lower end of the guide body 151 at regular intervals such that, when the lead pins 130 are mounted to the PCB, the ends of the position control parts 159 come into contact with the upper surface of the PCB.

The guide holder 160 protrudes from a side surface of the lower flange 115, which is opposite from the pin holder 120.

The subsidiary guide 170 engages with the guide holder 160 such that, when the lead pins 130 are mounted to the PCB, the subsidiary guide 170 can control the horizontal height of the transformer 100 and can support one end of the transformer 100.

Here, the subsidiary guide 170 includes a locking block 171 and a support arm 175, as shown in Fig. 5.

The locking block 171 is assembled with the guide holder 160 by a interference fitting method and, when the lead pins 130 are mounted to the PCB, the locking block 171 controls the horizontal height of the transformer according to the assembled position thereof relative to the guide holder 160.

The support arm 175 horizontally extends from the upper end of the locking block 171 and, when the lead pins 130 are mounted to the PCB, the support arm 175 comes into contact with the surface of the PCB and thereby supports an associated side of the transformer 100.

The above-mentioned pin guide 150 is assembled with the pin holder 120 by inserting the lead pins 130 into the respective pin insert holes 152 and thereby holds the lead pins 130, and, when the lead pins 130 are mounted to the pin mounting holes of the PCB, the pin guide 150 controls the depth to which the lead pins 130 are inserted.

Further, the subsidiary guide 170 is assembled with the guide holder 160 which is formed on a predetermined portion of the edge of the lower flange 115 of the bobbin 110 and, when the lead pins 130 are mounted to the pin mounting holes of the PCB, the subsidiary guide 170 controls the horizontal height of the transformer 100.

In the present invention, the bobbin 110, the pin guide 150 and the subsidiary guide 170 are made of an insulating material, such as plastic.

The above-mentioned transformer 100 is a PCB through-hole mounting type transformer, which can be mounted on a PCB 10 for adapters by being inserted into a through hole 15 of the PCB 10, as shown in Fig. 10, and can realize slimness of the adapters.

Figs. 6 through 11 are views illustrating a method of assembling and mounting the transformer for adapters according to the embodiment of the present invention.

Hereinbelow, the method of assembling and mounting the transformer 100 will be described in detail with reference to the drawings.

As shown in Fig. 6, the bobbin 110 includes the hollow body 111, the upper flange 113 and the lower flange 115, with the pin holder 120 formed on a predetermined portion of the edge of the upper flange 113 and the lead pins 130 horizontally coming off of a surface of the pin holder 120.

Both a first coil and a second coil are wound around the outer circumferential surface of the hollow body 111 of the bobbin 110 in such a way that the first and second coils are spaced apart from each other by a predetermined interval.

After winding the coils around the bobbin, ends of the coils are connected to the lead pins 130 through the pin holder 120.

Thereafter, the first core 140 and the second core 145 are assembled with each other such that they cover the upper flange 113 and the lower flange 115 of the bobbin 110, as shown in Fig. 7.

After assembling the first and

second cores

140 and 145, the lead pins 130 coming off of the surface of the upper flange are bent toward the lower flange 115 in the form of a ㄱ-shape.

Thereafter, the pin guide 150 is securely assembled with the pin holder 120 by fitting the pin insert holes 152 of the guide body 151 over the lead pins 130, as shown in Fig. 8, and by engaging the locking block 155 of the pin guide 150 with the locking protrusion 121 of the pin holder 120 by a interference fitting method.

After the pin guide 150 is fitted over the lead pins 130, the locking block 172 of the subsidiary guide 170 is assembled with the guide holder 160 formed on the predetermined portion of the lower flange 115 by a interference fitting method, so that the subsidiary guide 170 can be securely assembled with the guide holder 160.

Fig. 9 shows an assembled state in which the pin guide 150 and the subsidiary guide 170 have been assembled with the lead pins 130 and the guide holder 160, respectively.

The assembled transformer 100 can be automatically mounted to the through hole 15 of a PCB 10 by a wave soldering method using a soldering device, as shown in Fig. 10.

In the related art, the mounting, in which the transformer 100 is mounted into the through hole 15 of the PCB 10 as shown in Figs. 10 and 11, has been denoted as PCB through-hole mounting.

When the transformer 100 is mounted to the through hole 15, both the lower end of the first core 140 and the guide holder 160 are inserted into the through hole 15 of the PCB 10, while the lower end of the second core 145 is located above the PCB in a direction opposite to the inserted direction of the first core 140 based on the PCB 10, as shown in Fig. 11.

The PCB 10 used in the present invention has

devices

51 and 55 on opposite surfaces thereof, so that, when the depth to which the transformer 100 is inserted into the through hole is designed to be leveled with the maximum height of the device 55 mounted on the lower surface of the PCB 10, the present invention can realize the greatest slimness of a product, such as an adapter.

Of course, it is preferable that the inserted position of the transformer 100 be determined so that the spatial interference between the transformer and the devices is minimized and that the slim shape of the product is realized in consideration of the

devices

51 and 55 being mounted on the upper and lower surfaces of the PCB 10.

Here, the inserted position of the transformer 100 relative to the through hole 15 is determined both by the height of the position control part 159 of the pin guide 150 and by the assembled position of the subsidiary guide 170 relative to the guide holder 160.

In other words, the depth to which the lead pins 130 are inserted is equal to the inserted position of the transformer 100 relative to the through hole 15.

Of course, both the mounted position of the subsidiary guide 170 relative to the guide holder 160 and the height of the position control part 159 of the pin guide 150 may be adjusted as desired.

This means that the inserted position of the transformer 100 relative to the through hole can be controlled.

For example, when the lead pins 130 of the transformer 100 are deeply inserted into the pin insert holes of the pin guide, the length of the position control part 159 of the pin guide 150 becomes shorter and, furthermore, the assembled position of the subsidiary guide 170 relative to the guide holder 160 is moved upwards.

On the contrary, when the lead pins 130 of the transformer 100 are shallowly inserted into the pin insert holes of the pin guide, the length of the position control part 159 of the pin guide 150 becomes longer and, furthermore, the assembled position of the subsidiary guide 170 relative to the guide holder 160 is moved downwards.

Here, both the assembled position of the subsidiary guide 170 relative to the guide holder 160 and the length of the position control part 159 of the pin guide 150 are determined in cooperation with each other such that, when the transformer 100 is mounted on the PCB 10, the transformer 100 can be horizontal relative to the PCB 10.

As described above, both the position control part 159 of the pin guide 150 and the support arm 175 of the subsidiary guide 170 are located on the same horizontal line of the transformer 100, so that, when the transformer 100 is inserted into the through hole 15 as shown in Fig. 11, both the lower surface of the position control part 159 and the lower surface of the support arm 175 come into contact with the PCB.

Further, the present invention uses both the pin guide 150 and the subsidiary guide 170, so that the present invention can use the wave soldering method in PCB through-hole mounting, and can realize slimness of adapters due to the PCB through-hole mounting.

Further, the present invention can control the depth to which the transformer 100 is inserted into the through hole 15 of the PCB using both the pin guide 150 and the subsidiary guide 170 and thereby control the degree of slimness of a product without requiring changes to the basic shape of the transformer to realize the structure of the desired slim product.

As described above, in the PCB through-hole mounting, the present invention can use an automatic process, such as a wave soldering process, using both the pin guide 150 and the subsidiary guide 170, thus improving the productivity and the assembly quality of products.

In the above description, although the transformer of the present invention has been described as one being used in adapters, the transformer of the present invention may of course be used in a variety of electronic products in addition to the adapters.

Although the embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.

Claims

A transformer for adapters, comprising:

a bobbin including a hollow body having upper and lower flanges formed around upper and lower ends of the hollow body;

a pin guide fitted over a lead pin bent from a side of the upper flange toward the lower flange and controlling a depth to which the lead pin is inserted when the lead pin is mounted to a PCB (printed circuit board); and

a subsidiary guide assembled with a side of the lower flange and supporting a side of the transformer when the lead pin is mounted to the PCB.
The transformer for adapters as set forth in claim 1, wherein the pin guide comprises: a guide body having a pin insert hole into which the lead pin is inserted; a locking block extending upwards from an end of the guide body and assembled with a pin holder; and a position control part extending downwards from a predetermined portion of the guide body and controlling the depth to which the lead pin is inserted.
The transformer for adapters as set forth in claim 2, wherein the position control part comes at an end thereof into contact with a surface of the PCB when the lead pin is mounted to the PCB.
The transformer for adapters as set forth in claim 1, wherein the subsidiary guide is assembled with a guide holder protruding from the side of the lower flange.
The transformer for adapters as set forth in claim 4, wherein the subsidiary guide comprises: a locking block assembled with the guide holder by a interference fitting method; and a support arm horizontally extending from an upper end of the locking block and coming into contact with a surface of the PCB and thereby supporting the side of the transformer when the lead pin is mounted to the PCB.
The transformer for adapters as set forth in claim 5, wherein the locking block controls a horizontal height of the transformer by controlling an assembled position thereof when the lead pin is mounted to the PCB.
The transformer for adapters as set forth in claim 5, wherein both the position control part of the pin guide and the support arm of the subsidiary guide are located on a same horizontal line.
The transformer for adapters as set forth in claim 1, wherein the transformer is mounted to a through hole of the PCB.
The transformer for adapters as set forth in claim 1, wherein the transformer is mounted on the PCB by a wave soldering method.
A transformer for adapters, comprising:

a bobbin including a hollow body having upper and lower flanges formed around upper and lower ends of the hollow body;

a pin holder provided at a side of the upper flange and having a lead pin bent towards the lower flange; and

a pin guide assembled with the pin holder by being fitted over the lead pin and controlling a depth to which the lead pin is inserted when the lead pin is mounted to a PCB (printed circuit board).
The transformer for adapters as set forth in claim 10, wherein the pin guide comprises: a guide body having a pin insert hole into which the lead pin is inserted; a locking block extending upwards from an end of the guide body and assembled with the pin holder; and a position control part extending downwards from a predetermined portion of the guide body and controlling the depth to which the lead pin is inserted.
The transformer for adapters as set forth in claim 11, wherein an end of the position control part comes into contact with a surface of the PCB when the lead pin is mounted to the PCB.
The transformer for adapters as set forth in claim 10, further comprising: a guide holder protruding from another side of the lower flange; and a subsidiary guide assembled with the guide holder and supporting a side of the transformer when the lead pin is mounted to the PCB.
The transformer for adapters as set forth in claim 13, wherein the subsidiary guide comprises: a locking block assembled with the guide holder by a interference fitting method and controlling a horizontal height of the transformer according to an assembled position thereof when the lead pin is mounted to the PCB; and a support arm horizontally extending from an upper end of the locking block and coming into contact with a surface of the PCB and thereby supporting the side of the transformer when the lead pin is mounted to the PCB.