KR102647723B1 - Transformer - Google Patents

Abstract

The present invention relates to a transformer, which includes a main body 100 and cores 210 and 220 coupled to the main body 100, and the main body 100 includes a first bobbin 110 and a second bobbin 130. In addition, the second bobbin 130 has winding parts 111 and 131 on which the coils 120 and 140 are wound, and upper flanges 112 and 132 extending outward to support the coils 120 and 140, respectively, between the winding parts 111 and 131. ) and lower flanges 113 and 133, and the upper flange 132 and lower flange 133 of the second bobbin 130 have ridges (s1, s2, s3) and valleys (v1, It includes an uneven portion 139 formed by repeating waves v2 and v3) in a wave shape. The present invention has the advantage of significantly improving insulation by improving creepage distance by applying wave-shaped uneven parts to the second bobbin where the secondary coil is wound.

Description

TRANSFORMER

The present invention relates to transformers, and more specifically, to transformers applied to electrical and electronic devices.

A transformer is a power supply conversion device that converts power to an appropriate voltage.

A transformer includes a primary coil and a secondary coil that are magnetically coupled, and the basic principle is that when current flows in the primary coil, current also flows in the secondary coil due to electromagnetic induction. The ratio of the voltage of the primary coil to the transmitted voltage of the secondary coil corresponds to the ratio of the number of turns around the coil.

In these transformers, the magnetic field surrounding the primary coil induces a voltage around the secondary coil, and the desired output voltage can be obtained by changing the ratio of the number of turns wound on the coil.

In addition, in order to obtain various types of output voltages from a single transformer, a transformer can wind several primary coils or secondary coils and obtain various different voltages by combining the primary coils and secondary coils.

However, in a conventional transformer, the primary and secondary coils are only insulated in a way that is not electrically insulated, so it is necessary to secure an insulation distance. To this end, the inner bobbin where the primary coil is wound and the outer bobbin where the secondary coil is wound are separated. There is a problem in that the size of the transformer increases because the thickness must be thick.

The purpose of the present invention is to provide a transformer that significantly improves insulation by improving the creepage distance by applying wave-shaped concavo-convex portions to the second bobbin where the secondary coil is wound in a structure that secures the insulation distance by molding.

A transformer according to an embodiment of the present invention for solving the above problems includes a main body and a core coupled to the main body, the main body includes a first bobbin and a second bobbin, and the second bobbin has a coil wound. It includes an upper flange and a lower flange extending outwardly to support the coil with the winding part sandwiched between the winding part, and the upper flange and the lower flange of the second bobbin have ridges and valleys on the inner surface in the extending direction. It includes uneven portions repeatedly formed in a wave shape.

The uneven portion of the upper flange and the uneven portion of the lower flange have shapes that are symmetrical to each other.

The uneven portion may further include mountain portions of different heights.

The uneven portion may have the highest height of the outermost mountain portion.

The concavo-convex portion may have a shape in which the top of the outermost mountain portion is inclined toward the winding portion.

Excluding the portion where the outermost ridge is formed, the thickness of the upper flange and the lower flange where the ridge is formed is the same as or smaller than the thickness of the upper flange and the lower flange at the portion where the concave-convex portion is not formed.

The uneven portion may be formed on the edges of the upper flange and the lower flange.

The uneven portion may have peaks and valleys formed side by side along the edges of the upper flange and the lower flange.

The first bobbin is coupled to the second bobbin, and a bobbin combination of the first bobbin and the second bobbin is molded by a molding unit.

The first bobbin is formed with an injection groove for filling the space between the first bobbin and the second bobbin with the molding part.

The present invention is a structure that secures the insulation distance through molding, so the insulation distance between the primary and secondary sides can be secured, thereby reducing the size of the transformer, and by applying a wave-shaped concavo-convex portion to the second bobbin where the secondary coil is wound. By increasing the creepage distance, additional insulation distance can be secured without increasing the size of the transformer, which has the effect of significantly improving insulation.

In addition, the present invention has the effect of increasing the creepage distance without increasing the thickness of the transformer because the uneven portions are formed on both inner surfaces of the upper flange and the lower flange of the second bobbin.

In addition, the uneven portion of the present invention increases the injection bonding force with the molding portion that integrates the first bobbin and the second bobbin, thereby securing structural rigidity of the transformer and improving internal pressure.

Figure 1 is a perspective view showing a transformer according to an embodiment of the present invention.
Figure 2 is a perspective view of a transformer according to an embodiment of the present invention, showing the core being coupled to the main body.
FIG. 3 is a cross-sectional view taken along line AA of the main body of FIG. 2, and FIG. 4 is a perspective view showing a bobbin assembly in which the first bobbin and the second bobbin of FIG. 3 are combined.
Figure 5 is a perspective view showing the first and second bobbins of Figure 3 before they are combined, and Figure 6 is an enlarged view of the cross-section of Figure 3.
Figure 7 is a diagram comparing the creepage distance between the uneven portion (b) according to an embodiment of the present invention and the case without the uneven portion (a) as a comparative example.

Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings.

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

As shown in FIG. 1, the transformer 10 according to an embodiment of the present invention includes a main body 100 and a core 200 coupled to the main body 100. The main body 100 includes a coil inside and terminal pins 125 and 145 connected to the coil on the outside.

A plurality of terminal pins 125 and 145 are provided on one side and the other side of the main body 100, and each terminal pin 125 and 145 is spaced apart from each other and arranged in a row. In the embodiment, the terminal pin 125 arranged on one side of the main body 100 is an input terminal, and the terminal pin 145 arranged on the other side of the main body 100 is an output terminal.

Figure 2 is a perspective view of a transformer according to an embodiment of the present invention, showing the core being coupled to the main body.

As shown in FIG. 2, the main body 100 has molding flanges 101 and 102 formed on both sides and a core coupling portion 103 formed between them. The molding flanges 101 and 102 are formed by surrounding the bobbin assembly 150, which will be described later, with the molding portion 160 to a predetermined thickness. The core coupling portion 103 is a stepped portion between the molding flanges 101 and 102 on both sides. The core coupling portion 103 is formed with a first through hole 115 penetrating upward and downward in the central portion. The cores 210 and 220 are coupled to the first through hole 115 of the core coupling portion 103. The width and length of the core coupling portion 103 are designed in advance in consideration of the sizes of the cores 210 and 220 coupled to the core coupling portion 103.

Core 200 includes an upper core 210 and a lower core 220. The upper core 210 is coupled at the upper part of the main body 100 and the lower core 220 is coupled at the lower part of the main body 100. The upper core 210 and lower core 220 coupled at the top and bottom of the main body 100 surround the coil included in the main body 100 and form a magnetic path to control the electric flow of the coil. As an example, the main body 100 includes a primary coil 120 and a secondary coil 140, and the high voltage flowing into the primary coil 120 generates induced electromotive force in the adjacent secondary coil 140. It can be output at a low voltage.

The upper core 210 and lower core 220 are formed in a shape including a flat plate portion (a), both leg portions (b), and a central leg portion (c). Specifically, the upper core 210 and the lower core 220 have both leg portions (b) protruding vertically from both sides of the flat plate portion (a), and the central leg portion (c) is formed between the two leg portions (b). It is formed in an E-shaped cross-sectional shape that protrudes vertically from the.

The upper core 210 and the lower core 220 have a flat plate part (a) in close contact with the upper or lower surface of the core coupling part 103, and both leg parts (b) in close contact with both sides in the width direction of the core coupling part 103. It is coupled to the main body 100 in such a way that the central leg portion (c) is inserted into the first through hole 115.

The upper core 210 and lower core 220 are made of magnetic material. The magnetic material is made of ferromagnetic material that can produce strong magnetic flux, and a ferrite core with low loss at high frequencies can be used. As an example, a Mn-Zn ferrite core may be used as the magnetic material.

FIG. 3 is a cross-sectional view taken along line A-A of the main body of FIG. 2, and FIG. 4 is a perspective view showing a bobbin assembly in which the first bobbin and the second bobbin of FIG. 3 are combined.

As shown in FIG. 3, the main body 100 uses two bobbins, winds a coil on each bobbin, and then fits the top and bottom to form a secondary coil 140 disposed outside the primary coil 120. It becomes a structure. The primary coil 120 and the secondary coil 140 are insulated with the bobbins 110 and 130 to reduce the leakage inductance (Lk) between the primary coil 120 and the secondary coil 140.

The main body 100 includes a first bobbin 110 and a second bobbin 130. The primary coil 120 is wound on the first bobbin 110 and the secondary coil 140 is wound on the second bobbin 130. When the first bobbin 110 on which the primary coil 120 is wound is coupled to the second bobbin 130 on which the secondary coil 140 is wound, a bobbin combination body 150 is formed. The bobbin combination 150 in which the first bobbin 110 and the second bobbin 130 are combined is molded by the molding unit 160. The molding portion 160 is made of an insulating material to insulate the primary coil 120 and the secondary coil 140 from the outside and protect the coils from moisture, etc. The primary coil 120 wound around the first bobbin 110 and the secondary coil 140 wound around the second bobbin 130 are finally insulated from the outside by the molding unit 160.

In addition, the portion where the primary coil 120 and the first terminal pin 125 are connected and the portion where the secondary coil 140 and the second terminal pin 145 are connected are molded by the molding unit 160 after soldering. are not exposed to the outside, and the end sides of the first terminal pin 125 and the second terminal pin 145 are exposed to the outside of the molding part 160 and can be mounted on the board.

As shown in FIGS. 3 and 4, the first bobbin 110 is provided with a first terminal pin 125 protruding downward on one side and a first through hole 115 is formed in the central portion. The central leg portion (c) of the upper core 210 and lower core 220 is coupled to the first through hole 115. A primary coil 120 is wound around the first bobbin 110. The end of the primary coil 120 wound on the first bobbin 110 is connected to the first terminal pin 125 by soldering. As an example, the end copper wire of the primary coil 120 wound on the first bobbin 110 can be wound and connected to the first terminal pin 125 and then fixed by soldering.

The second bobbin 130 is provided with a second terminal pin 145 protruding downward on the other side and a second through hole 135 is formed in the central portion. The first bobbin 110 is fitted into the second through hole 135 from top to bottom. A secondary coil 140 is wound around the second bobbin 130. The end of the secondary coil 140 wound on the second bobbin 130 is connected to the second terminal pin 145 by soldering. As an example, the end copper wire of the secondary coil 140 wound on the second bobbin 130 can be wound and connected to the second terminal pin 145 and then fixed by soldering.

Figure 5 is a perspective view showing the first and second bobbins of Figure 3 before they are combined, and Figure 6 is an enlarged view of the cross-section of Figure 3.

As shown in FIG. 5, the first bobbin 110 and the second bobbin 130 extend outward to support the coil, respectively, with the winding parts 111 and 131 on which the coil is wound, and the winding parts 111 and 131 interposed therebetween. It includes upper flanges 112 and 132 and lower flanges 113 and 133. The first bobbin 110 and the second bobbin 130 are made of an insulating material, and are preferably made of injection-molded plastic.

As shown in FIGS. 5 and 6, the first bobbin 110 and the second bobbin 130 overlap the upper and lower flanges 112 and 132 or the lower flanges 113 and 133 so that they can be well coupled when fitted together. A falling step is formed.

Specifically, the first bobbin 110 has first step surfaces 117a and 117b formed along the outer edges of the bottom surfaces of the upper flange 112 and the lower flange 113, respectively, and the second bobbin 130 has the upper flange 113. Second step surfaces 137a and 137b are formed along the inner edges of the flange 132 and the lower flange 133, respectively. Accordingly, when the first bobbin 110 is inserted into the second through hole 135 of the second bobbin 130, the first step surfaces 117a and 117b on the bottom of the first bobbin 110 are formed on the second bobbin 130. ) overlaps vertically with the second step surfaces 137a and 137b on the upper surface, making it easy to fit and the combined state to be stable. For this purpose, the upper flange 112 of the first bobbin 110 of the embodiment extends further outward than the lower flange 113, and the lower flange 133 of the second bobbin 130 has a second through hole. It is extended to (135).

In the embodiment, the first bobbin 110 is fitted into the second through hole 135 of the second bobbin 130 from the top to the bottom, so that the first step surfaces 117a and 117b are connected to the first bobbin 110. is formed on the bottom of the upper flange 112 and lower flange 113, and second step surfaces 137a and 137b are formed on the upper surface of the upper flange 132 and lower flange 133 of the second bobbin 130. However, on the contrary, if the first bobbin 110 is manufactured in a structure in which the first bobbin 110 is fitted to the second bobbin 130 from the bottom to the top, the first step surfaces 117a and 117b are of the first bobbin 110. It is formed on the upper surface of the upper flange 112 and the lower flange 113, and the second step surfaces 137a and 137b are formed on the lower surface of the upper flange 132 and the lower flange 133 of the second bobbin 130. It may be possible.

An injection groove 118 is formed in the first bobbin 110 to fill the space between the first bobbin 110 and the second bobbin 130 with the molding part 160. The injection groove 118 forms a hole through which an insulating material (injected product) can be injected between the first bobbin 110 and the second bobbin 130.

The first bobbin 110 and the second bobbin 130 are integrated by injecting the injection product through the injection groove 118 of the first bobbin 110, and the primary coil 120 wound on the first bobbin 110 is integrated. A surrounding molding portion 160 is formed.

An injection hole 138 is formed in the lower flange 133 of the second bobbin 130. The injection hole 138 is formed at a position in communication with the injection groove 118 to fill the space between the first bobbin 110 and the second bobbin 130 with the molding portion 160. When the space between the first bobbin 110 and the second bobbin 130 is filled with the molding part 160 through two holes consisting of the injection groove 118 and the injection hole 138, the first bobbin 110 is formed without generating bubbles. ) and the second bobbin 130 can be uniformly filled with the molding part 160, thereby protecting the primary coil 120 from moisture, etc.

Meanwhile, as shown in FIGS. 5 and 6, the upper flange 132 and the lower flange 133 of the second bobbin 130 have irregularities formed by repeating ridges and valleys in a wave shape in the longitudinal direction on both inner surfaces. Includes (139).

The uneven portion 139 is intended to secure additional insulation distance by increasing the creepage distance. Creepage distance is the shortest distance along the surface of an insulating material between two conductors, and insulation distance is the shortest distance between two conductors in air, that is, clearance (air insulation distance).

The insulation distance to prevent leakage current in the transformer (10) is Degree 2 and 1.0mm in the case of an open structure when set as a contamination standard. In other words, when manufacturing a transformer with an open structure in which the coil of the winding part is exposed to the outside, the insulation distance (length (m) to the end of the second bobbin excluding the winding part where the secondary coil is wound) must be 1.0 mm or more.

Table 1 below shows the minimum air insulation distance according to pollution level.

Pollution degree
(see 13.1) X
mm One 0.25 2 1.0 3 1.5

In Table 1, the minimum air insulation distance refers to the space distance that must be secured to prevent contamination. Contamination refers to foreign substances that can reduce the electrical strength and surface resistance of an insulator.

The space distance can be reduced by using the molding part 160.

In the embodiment of the present invention, the coil portions of the first bobbin 110 and the second bobbin 130 are blocked by the molding part 160, so that the space distance can be designed to be 0.25 mm or more, which is Degree 1, since it has an insulating structure without contamination. . Therefore, in the present invention, the coil portion of the first bobbin 110 and the second bobbin 130 is molded with the molding part 160, the space distance is designed to be Degree 1, 0.25mm, and the uneven part 139 is applied to By increasing the creepage distance, additional insulation distance can be secured.

As shown in FIG. 6, the peaks (s1, s2, s3) and valleys (v1, v2, v3) of the uneven portion 139 of the upper flange 132 are of the uneven portion 139 of the lower flange 133. It has a symmetrical shape with the mountain parts (s1, s2, s3) and the valley parts (v1, v2, v3). If the concavo-convex portion 139 of the upper flange 132 and the concave-convex portion 139 of the lower flange 133 are formed in shapes that are symmetrical to each other, the second bobbin 130 can be easily formed into a shape and taken out.

The uneven portion 139 may have different heights of adjacent mountain portions s1, s2, and s3. The uneven portion 139 strengthens the overall structure of the main body 100 by improving the bonding force between the injection molding portion and the injection molding portion 160. If the heights of the mountain parts s1, s2, and s3 adjacent to each other in the uneven part 139 are different from each other, the injection bonding force is further improved, which is advantageous in strengthening the overall structure of the main body 100.

In the uneven portion 139, the outermost mountain portion s3 has the highest height. This makes the height of the winding section 131 lower on the outside than on the inside, allowing the coil to be wound around the winding section 131 with ample room, and preventing the coil wound on the winding section 131 from coming off arbitrarily. . In addition, the outermost mountain part (s3) protrudes more than the other mountain parts (s1, s2) to secure additional insulation distance, and the protruding height protrudes to the maximum possible level for automatic winding.

In addition, the uneven portion 139 is preferably shaped so that the top of the outermost ridge s3 is inclined inward, which means that even if the height of the outer side of the winding portion 131 is lower than that of the inner side, the coil can be wound. This is to facilitate automatic winding by ensuring that it is well inserted into the part 131. In other words, ensure that the coil is wound well and does not unwind.

The uneven portion 139 has the remaining ridges (s1, s2) excluding the outermost ridge (s3) within the thickness range of the upper flange (132) and the lower flange (133). ) forms a height that is equal to or relatively lower than the inner height of the Specifically, excluding the portion where the outermost mountain is formed, the thickness of the upper flange 132 and the lower flange 133 where the mountain is formed is the upper flange 132 and the lower flange ( 133) is equal to or smaller than the thickness. This is an advantage in that the uneven portion 139 is formed in a negative manner on the upper flange 132 and the lower flange 133, increasing the creepage distance and improving the injection bonding force with the injection molded product without adversely affecting the automatic winding of the coil. This is to ensure that

It is preferable that the uneven portions 139 are formed only on the edges of both inner surfaces of the upper flange 132 and the lower flange 133. Since the uneven portion 139 is formed to increase the creepage distance in the length (space distance) (m) to the end of the second bobbin 130 excluding the winding portion 131 where the secondary coil is directly wound, the uneven portion ( 139) is preferably formed vertically only at the edges of the inner surface in the extending direction of the upper flange 132 and the lower flange 133.

If the uneven portion 139 is formed even in the area where the coil is directly wound, it may be difficult to wind the coil stably. The inner surfaces on both sides of the upper flange 132 and the lower flange 133 corresponding to the winding part 131 where the secondary coil 140 is directly wound are formed flat so that the coil is press-fitted into the winding part 131, so that the coil is It is desirable to have a stable winding.

The uneven portion 139 may have a wave shape in which the heights and spacing of the peaks (s1, s2, s3) and valleys (v1, v2, and v3) are irregular. The height and spacing of the ridges (s1, s2, s3) and the valleys (v1, v2, v3) are irregular, but except for the outermost ridge (s3), the remaining ridges (s1, s2) are connected to the upper flange 132 and the lower flange. It is desirable to form a height that is the same as or relatively lower than the inner height of the upper flange 132 and the lower flange 133 within the thickness range of the flange 133.

That is, except for the portion where the outermost peak s3 is formed, the thickness of the upper flange 132 and the lower flange 133 where the peak portions s1 and s2 are formed is the upper portion where the uneven portion 139 is not formed. It is preferable that the thickness is equal to or smaller than the thickness of the flange 132 and the lower flange 133.

These uneven portions 139 may have peaks and valleys formed side by side along the edges of the upper flange 132 and the lower flange 133.

Figure 7 is a diagram comparing the creepage distance between the uneven portion (b) according to an embodiment of the present invention and the case without the uneven portion (a) as a comparative example.

For example, as shown in FIG. 7, the length (space distance) (m) to the end of the second bobbin 130 excluding the winding portion 131 where the secondary coil 140 is directly wound is 2.5 mm. In the case of design and no unevenness (a), the creepage distance is calculated to be 4.43mm. The part where the creepage distance was calculated is shown in bold color.

On the other hand, the length (space distance) (m) to the end of the second bobbin 130 excluding the winding part 131 where the secondary coil 140 is directly wound is designed to be 2.5 mm and the uneven part 139 is applied. In case (b), the creepage distance is calculated to be 5.72mm.

These uneven portions 139 are applied in the same size as the existing secondary bobbin 130 and increase the creepage distance to secure additional insulation distance, thereby contributing to miniaturization of the transformer, ensuring safety, and improving product reliability. do.

In addition, the uneven portion 139 is formed on the inner surface of the upper flange 132 and the lower flange 133 of the second bobbin 130, so there is no need to increase the size of the transformer to improve insulation performance, thereby reducing the size of the transformer. can also contribute.

Hereinafter, the operation of the present invention will be described.

The transformer (10) of the present invention has an insulating structure without contamination by applying the molding part (160), so it can be recognized by the certification body when designing the space distance to 0.25 mm or more, which is Degree 1, and the size of the transformer (10) can be reduced.

In addition, the transformer 10 of the present invention increases the creepage distance by applying uneven portions 139 to both inner surfaces of the upper flange 132 and the lower flange 133 of the second bobbin 130, so that the transformer 10 Additional insulation distance can be secured without increasing the size, greatly improving insulation.

In addition, the uneven portion 139 is formed not on the outer surface of the upper flange 132 and the lower flange 133 but on the inner surface, so that the overall height of the transformer 10 can be lowered. It is possible to secure additional insulation distance by forming the uneven portion 139 on the outer surface of the upper flange 132 and the lower flange 133, but in this case, the height of the transformer increases. That is, the embodiment of the present invention can additionally secure the insulation distance without increasing the height of the transformer 10.

In addition, the uneven portion 139 can increase the injection bonding force with the molding portion 160 to secure the structural rigidity of the transformer 10 and improve internal pressure.

In addition, in the present invention, since the first bobbin 110 is completely sealed by the molding part 160 in the state of being coupled to the second bobbin 130, stable winding of the primary coil 120 and the secondary coil 140 is maintained. and insulation can be secured.

In addition, in the present invention, since the first bobbin 110 and the second bobbin 130 form an integrated structure by the molding part 160, assembly of the cores 210 and 220 is easy and the manufacturing process is simple, thereby increasing productivity. .

In addition, in the present invention, the portion where the terminal pins (125, 145) and the copper wires at the ends of the coils (120, 140) are connected are molded by the molding portion (160), thereby preventing short circuit of the connecting portion of the coils (120, 140) and the terminal pins (125, 145). This can improve product reliability.

The above-described transformer can be installed in TVs, monitors, LED drive power supplies, PC power supplies, etc. to ensure stable power supply. The uneven part applied to the transformer can be applied to various devices to secure the insulation distance while miniaturizing the size.

The best embodiments of the present invention are disclosed in the drawings and specification. Here, specific terms are used, but they are used only for the purpose of describing the present invention and are not used to limit the meaning or scope of the present invention described in the claims. Therefore, those skilled in the art will understand that various modifications and equivalent embodiments of the present invention are possible therefrom. Therefore, the true technical scope of the present invention should be determined by the technical spirit of the attached claims.

10: Transformer 100: Body
101,102: molding flange 103: core joint
110: first bobbin 111: winding section
112: upper flange 113: lower flange
115: first through hole 117a, 117b: first step surface
118: Injection groove 120: Primary coil
125: 1st terminal pin 130: 2nd bobbin
131: winding part 132: upper flange
133: lower flange 135: second through hole
137a, 137b: second step surface 138: injection groove
139: uneven part s1, s2, s3: mountain part
v1, v2, v3: valley 140: secondary coil
145: Second terminal pin

Claims (10)

main body; and
a core coupled to the main body;
Including,
The body is
Includes a first bobbin and a second bobbin,
The second bobbin is
A winding section where a coil is wound;
It includes an upper flange and a lower flange extending outward to support the coil, with the winding part interposed therebetween,
The upper flange and the lower flange of the second bobbin include uneven portions formed by repeating ridges and valleys in a wave shape on the inner surface in the extending direction,
A transformer in which the uneven portion of the upper flange and the uneven portion of the lower flange are symmetrical to each other. delete According to paragraph 1,
A transformer wherein the uneven portion further includes mountain portions of different heights. main body; and
a core coupled to the main body;
Including,
The body is
Includes a first bobbin and a second bobbin,
The second bobbin is
A winding section where a coil is wound;
It includes an upper flange and a lower flange extending outward to support the coil, with the winding part interposed therebetween,
The upper flange and the lower flange of the second bobbin include uneven portions formed by repeating ridges and valleys in a wave shape on the inner surface in the extending direction,
The uneven portion is a transformer in which the height of the outermost ridge is the highest. main body; and
a core coupled to the main body;
Including,
The body is
Includes a first bobbin and a second bobbin,
The second bobbin is
A winding section where a coil is wound;
It includes an upper flange and a lower flange extending outward to support the coil, with the winding part interposed therebetween,
The upper flange and the lower flange of the second bobbin include uneven portions formed by repeating ridges and valleys in a wave shape on the inner surface in the extending direction,
The uneven portion is a transformer in which the top of the outermost peak is inclined toward the winding portion. main body; and
a core coupled to the main body;
Including,
The body is
Includes a first bobbin and a second bobbin,
The second bobbin is
A winding section where a coil is wound;
It includes an upper flange and a lower flange extending outward to support the coil, with the winding part interposed therebetween,
The upper flange and the lower flange of the second bobbin include uneven portions formed by repeating ridges and valleys in a wave shape on the inner surface in the extending direction,
The thickness of the upper flange and the lower flange on which the ridge is formed, excluding the portion where the outermost ridge is formed, is,
A transformer that is equal to or smaller than the thickness of the upper flange and the lower flange in the portion where the uneven portion is not formed. According to paragraph 1,
A transformer wherein the uneven portion is formed on the edges of the upper flange and the lower flange. main body; and
a core coupled to the main body;
Including,
The body is
Includes a first bobbin and a second bobbin,
The second bobbin is
A winding section where a coil is wound;
It includes an upper flange and a lower flange extending outward to support the coil, with the winding part interposed therebetween,
The upper flange and the lower flange of the second bobbin include uneven portions formed by repeating ridges and valleys in a wave shape on the inner surface in the extending direction,
The uneven portion is a transformer in which peaks and valleys are formed side by side along the edges of the upper flange and the lower flange. According to paragraph 1,
The first bobbin is coupled to the second bobbin,
A transformer in which the bobbin combination of the first bobbin and the second bobbin is molded by a molding unit. According to clause 9,
The first bobbin is a transformer in which an injection groove is formed to fill the space between the first bobbin and the second bobbin with the molding part.