JP7141848B2 - coil parts - Google Patents

Description

The present invention relates to coil components.

A coil component includes a bobbin that also serves as a terminal block and is called a substrate-mounted type that can be mounted on a substrate. 2. Description of the Related Art A bobbin for a substrate-mounted coil component is integrally formed with a winding shaft portion around which a coil winding is wound and a terminal block, and terminals protrude from the terminal block. The terminal consists of a linear conductor, and the intermediate part is embedded in the bobbin. One end of the terminal is a mounting terminal that is fixed to the board by soldering or the like when the coil component is mounted on the board, and the other end is where the winding start and end of the coil winding are wound. It is a so-called "tying terminal".

FIG. 1 shows an example of a bobbin 103 with a terminal block 32. As shown in FIG. The three directions of right and left, front and back, and up and down, which are orthogonal to each other, are defined, and the direction of the winding axis 100 of the coil is defined as the front and back direction. Furthermore, assuming that the coil component is mounted on the upper surface of the plane including the front-rear direction and the left-right direction, the bobbin 3 includes a hollow cylindrical winding shaft portion 31 having openings at the front end and the rear end. A terminal block 32 having a plurality of terminals 4 is integrally formed below 31 . Each terminal 4 is bent in an L shape, and a binding terminal 41 protrudes forward and backward from the front end and rear end of the terminal block 32, respectively, and is used as a mounting terminal (hereinafter referred to as a mounting terminal 42). ) protrudes downward.

By the way, not only coil components but also electronic components are required to be downsized to reduce the mounting area and to be low in height to suppress the vertical height when mounted. As for the height reduction of the coil component, the height of the coil component can be suppressed by adopting a "horizontal type" in which one direction parallel to the mounting surface is the winding axis direction of the coil. However, if the horizontal coil component handles high voltage, such as a gate drive transformer for an insulated gate bipolar transistor (IGBT) used as an automotive power transformer, it becomes difficult to reduce the size. .

Specifically, in coil parts such as IGBT gate drive transformers, the voltage between the coil windings or core and the terminals is varied according to the specifications such as the requirements from the electronic circuit side and the voltage value handled by the coil parts. A certain insulation distance must be provided. Since the winding of a coil is normally provided with a coating layer made of an insulating material on its surface, the insulation distance to be secured is the distance between the core and the terminals. The insulation distance includes the shortest space insulation distance that connects the core and the terminal through the space, and the shortest insulation distance along the surface of the insulation that is on the shortest path that connects the core and the terminal. There is also a creepage insulation distance that connects the core and the terminal at the shortest distance.

In a horizontal coil component, which is advantageous in reducing the height, the center leg of the core protrudes in the front-rear direction, so the core becomes wider in the front-rear direction. However, if the binding terminal protrudes forward and backward from the terminal block of the bobbin, the bobbin must be widened in the front-rear direction in order to secure a space insulation distance between the core that is wide in the front-rear direction and the binding terminal. There is a need to. That is, it is necessary to increase the distance between the core and the front and rear end surfaces of the bobbin where the binding terminal protrudes. Alternatively, it is necessary to increase the vertical distance between the position of the bobbin where the binding terminal protrudes and the core. However, if the distance in the vertical direction is increased, the effect of reducing the height of the horizontal type cannot be obtained. Therefore, some of the horizontal coil components are provided with a cover interposed on the path between the core and the terminal passing through the space to secure the insulation distance. Patent Document 1 below describes a "covered winding component" which is a coil component provided with a cover.

Japanese Patent Application Laid-Open No. 2006-237203

As described above, the coil component including the bobbin integrally formed with the terminal block is of a horizontal type in which the coil winding is wound around the longitudinal direction as the winding axis in order to achieve a low profile. there is In addition, in the conventional horizontal coil component, a cover that covers the upper part of the terminal is required in order to achieve miniaturization while ensuring the insulation distance. However, the cover of the conventional coil component has a frame-like structure so as to cover the terminals from above while being attached to the winding shaft of the bobbin. The cover is a molded product made of an insulating resin, and the frame-shaped molded product is likely to cause well-known welds that cause poor appearance and insufficient strength. In other words, there is a possibility that the yield of the conventional coil component will decrease.

One aspect of the present invention for achieving the above object is to provide a
A coil component that includes terminals and is mounted on a surface that includes the front-rear and left-right directions,
A coil in which a wire is wound around a longitudinal axis, a core having a middle leg, a bobbin around which the wire is wound, and a cover made of an insulating material attached to the bobbin. prepared,
The bobbin has an opening in the front and the rear, and a terminal block is integrally formed below a hollow cylindrical winding shaft portion on which the winding is wound, and the terminals protrude from the front surface and the rear surface,
The core has the middle leg inserted through the hollow portion of the winding shaft,
The cover is formed in an H shape when viewed from the top and bottom by connecting eaves extending in the left-right direction to front and rear ends of the cover by connecting portions extending in the front-rear direction. configured to be able to be inserted into the
The connection portion is arranged in the hollow portion of the winding shaft portion in a state of being arranged below the middle leg of the core,
When viewed from the front-rear direction, both left and right ends of the eaves portion are bent downward to collectively cover the upper side of the terminal projecting from the terminal block and the left and right sides of the terminals at both the left and right ends.
The coil component is characterized by:

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a low-profile coil component with a secured insulation distance at a lower cost.

One aspect of the present invention for achieving the above object is to provide a
A coil component that includes terminals and is mounted on a surface that includes the front-rear and left-right directions,
A coil in which a wire is wound around a longitudinal axis, a core having a middle leg, a bobbin around which the wire is wound, and a cover made of an insulating material attached to the bobbin. prepared,
The bobbin has an opening in the front and the rear, and a terminal block is integrally formed below a hollow cylindrical winding shaft portion on which the winding is wound, and the terminals protrude from the front surface and the rear surface,
The core has the middle leg inserted through the hollow portion of the winding shaft,
The cover is formed in an H shape when viewed from the top and bottom by connecting eaves extending in the left-right direction to front and rear ends of the cover by connecting portions extending in the front-rear direction. configured to be able to be inserted into the
The connection portion is arranged in the hollow portion of the winding shaft portion in a state of being arranged below the middle leg of the core,
An upper part of the terminal protruding from the terminal block is covered with the eaves part,
The coil component is characterized by:

It is more preferable to form a coil component in which a groove extending in the front-rear direction is formed in the lower surface of the hollow portion of the winding shaft portion, and the connection portion is arranged in the groove.

ADVANTAGE OF THE INVENTION According to this invention, the low-height coil component which the insulation distance was ensured can be provided more cheaply. Other effects will be clarified in the following description.

FIG. 4 is an external view of a bobbin that constitutes the coil component; 1 is an external view of a coil component according to an embodiment of the present invention; FIG. It is an exploded perspective view of the coil component according to the above embodiment. It is a figure which shows the arrangement|positioning relationship of the bobbin and cover which comprise the coil components which concern on the said Example. It is a figure which shows the bobbin and cover which comprise the coil component which concerns on a comparative example. It is a figure for comparing the size of the coil component concerning the above-mentioned example, and the coil component concerning the above-mentioned comparative example. It is a figure which shows the modification of the bobbin which comprises the coil components which concern on the said Example.

Embodiments of the present invention will be described with reference to the accompanying drawings. In addition, in the drawings used for the following description, the same or similar parts may be denoted by the same reference numerals, and redundant description may be omitted. Depending on the drawing, unnecessary reference numerals may be omitted for explanation.

=== Example ===
FIG. 2 is an external view of the coil component 1 according to the embodiment of the invention. In the following description, the vertical, horizontal, and front/rear directions of the coil component 1 according to the embodiment of the present invention are defined in the same manner as the bobbin shown in FIG. 2A is a perspective view of the coil component 1 viewed from the upper right front, and FIG. 2B is a perspective view of the coil component 1 viewed from the lower right front. As shown in FIG. 2, the coil component 1 according to the embodiment includes a coil 6 having a winding shaft 100 in the front-rear direction, a bobbin 3 integrally formed with a terminal block 32 to which a terminal 4 is attached, a coil A core 2 surrounds 6 to form a closed magnetic circuit. In the coil component 1 shown in FIG. 2, the core 2 is composed of two core members (2a, 2b) facing each other in the front-rear direction. Each core member ( 2 a, 2 b ) has a trapezoidal notch at the lower end side so as to reduce the height of the coil component 1 and prevent contact with the binding terminal 41 . In other words, the binding terminal 41 is arranged in the trapezoidal notched region of the core members (2a, 2b). Thereby, the lower end position of the core 2 is lowered to near the lower end of the bobbin 3. A tape 5 is wound around the core 2 so that the two core members (2a, 2b) are not separated from each other. Then, as shown in FIG. 2(B), the coil component 1 has an insulating structure that covers the upper side of the binding terminal 41 in an eave shape in order to secure an insulating distance between the core 2 and the binding terminal 41 . is provided with a cover 7 of

FIG. 3 shows an exploded perspective view of the coil component 1 according to the embodiment. The core 2 is an EE type composed of two E-shaped core members (2a, 2b) facing each other in the front-rear direction. The bobbin 3 has a terminal block 32 integrally formed below a winding shaft portion 31 around which the winding of the coil 6 is wound. A binding terminal 41 protrudes forward and rearward. The winding shaft portion 31 is in the shape of a hollow rectangular tube that is open forward and backward, and a coil 6 is formed by winding a wire around the outer circumference of the winding shaft portion 31 . The middle legs 21 of the E-shaped cores (2a, 2b) are inserted through the hollow portion 33 of the winding shaft portion 31. As shown in FIG.

The cover 7 is an integral member in which eaves 71 extending in the left-right direction forward and rearward are connected by connecting portions 72 extending in the front-rear direction, and has an H shape when viewed from above and below. is doing. The lateral width W1 of the eaves portion 71 is set to be greater than or equal to the width W2 that allows the hollow portion 33 of the winding shaft portion 31 to be inserted in the front-rear direction, and also allows the plurality of binding terminals 41 arranged in the lateral direction to be collectively covered. ing. In this embodiment, the lateral width W1 of the eaves portion 71, the lateral width W2 of the region where the binding terminal 41 is formed, and the lateral width W3 of the hollow portion 33 have a relationship of W3>W1>W2. there is As a result, the cover 7 can be easily inserted into the hollow portion 33 and the area where the binding terminal 41 is formed can be reliably covered by the eaves portion 71 . In this embodiment, the shape of the opening of the hollow portion 33 is oval. Even if the length is less than W1, the cover 7 can be inserted into the hollow portion 33 if the length of the diagonal line of the hollow portion 33 is larger than the lateral width W3 of the eaves portion 71 . Of course, the cover 7 may be made of elastic resin, and the cover 7 may be inserted into the hollow portion 33 of the winding shaft portion 31 when the eaves portion 71 is bent. In any case, it is sufficient that the cover 7 is configured to be able to be inserted into the hollow portion 33 of the winding shaft portion 31 .

Both the left and right ends of the eaves portion 71 are bent downward so as to cover the sides of the binding terminals 41 on the left and right ends. As a result, the eaves 71 cover the left and right side surfaces of the binding terminals 41 arranged at the left and right ends, so that the core 2 and the binding terminals 41 are more reliably insulated.

By the way, in the coil component 1 of the present embodiment, a groove 34 extending in the front-rear direction is formed in the lower surface of the hollow portion 33 of the winding shaft portion 31 . By arranging the connecting portion 72 of the cover 7 along the groove 34, the cover 7 is prevented from shifting in the left-right direction. In this embodiment, the lateral width W4 of the groove 34 is substantially the same as the lateral width of the connecting portion W5, and the connecting portion 72 is fitted in the groove 34 without play.

Next, a procedure for assembling the coil component 1 according to the embodiment will be described. First, a wire is wound around the winding shaft portion 31 of the bobbin 3 to form the coil 6 , and then the ends of the wire are wound around the binding terminal 41 . Next, the cover 7 is inserted through the hollow portion 33 of the winding shaft portion 31 . The connecting portion 72 of the cover 7 is fitted into the groove 34 inside the hollow portion 33 . As a result, as shown in FIG. 4, the eaves 71 collectively cover the upper sides of the four binding terminals 41 protruding forward and backward, and the left and right sides of the binding terminals 41a at both left and right ends. . Then, the middle legs 21 of the core members (2a, 2b) are inserted into the hollow portion 33 of the winding shaft portion 31 of the bobbin 3 to form the EE type core 2, and the tape 5 is wound around the core 2. The two core members (2a, 2b) are thereby fixed. Thus, the coil component 1 is completed.

As described above, in the coil component 1 of this embodiment, the H-shaped cover 7 covers the binding terminal 41 from above. Therefore, unlike a frame-shaped cover, welds do not occur, and it is possible to suppress a decrease in yield due to poor appearance and insufficient strength. Furthermore, the coil component 1 according to the embodiment is provided with the H-shaped cover 7, thereby achieving a lower profile than the coil component provided with the frame-shaped cover.

Next, a coil component having a frame-like cover will be taken as a comparative example in order to explain how the coil component 1 according to the embodiment is reduced in height. FIG. 5 shows the frame-like cover 8 and the bobbin 103 included in the coil component according to the comparative example. 5A shows the bobbin 103 and the cover 8 separately, and FIG. 5B shows the state where the cover 8 is attached to the bobbin 103. FIG. As shown in FIG. 5, the bobbin 103 of the coil component according to the comparative example is the same as the bobbin 103 shown in FIG. Both have almost the same configuration. However, in bobbin 103 of the coil component according to the comparative example, groove 34 is not formed in the lower surface of hollow portion 33 .

In the coil component according to the comparative example, as shown in FIG. 5A, the cover 8 has a frame-like shape with an opening in the vertical direction, and has a shape in which the left and right central portions of the flat plate-like frame are bent into a trapezoidal shape. ing. Then, as shown in FIG. 5B, when the winding shaft portion 31 of the bobbin 103 is inserted into the opening 81 of the frame-shaped cover 8, the trapezoidal region collectively covers the binding terminal 41 from above. .

FIG. 6 shows the difference in outer dimensions between the coil component according to the example (hereinafter also referred to as Example 1) and the coil component according to the comparative example (hereinafter also referred to as Comparative Example 101). FIG. 6 shows a side view of Example 1 and Comparative Example 101 viewed from the left and right. Also, the covers (7, 8) are indicated by diagonal hatching.

Example 1 and Comparative Example 101 use the same core 2, and the size of each coil component (1, 101) in the front-back direction and the size in the left-right direction are defined by the size of the core 2. 1 and Comparative Example 101 have the same size when viewed in the vertical direction. However, as shown in FIG. 6, in Comparative Example 101, since the frame-shaped cover 8 is used, the frame portions of the cover 8 are arranged on the left and right sides of the trapezoidal region covering the binding terminal 41. It will be. Therefore, in Comparative Example 101, it is necessary to make the vertical size of the terminal block 32 of the bobbin 103 slightly larger than that of the bobbin 3 of Example 1 so that the frame portion is arranged below the core 2. be. Therefore, even if the vertical size of the core 2 is the same between Example 1 and Comparative Example 101, the vertical size of Example 1 is smaller.

===Other Examples===
In the coil component 1 according to the embodiment, the connection portion 72 of the cover 7 is fitted into the groove 34 formed inside the hollow portion 33 of the winding shaft portion 31 . Therefore, the middle leg 21 of the core 2 can be inserted through the hollow portion 33 without increasing the vertical size of the hollow portion 33 of the winding shaft portion 31 . That is, the coil component 1 according to the embodiment has the groove 34 formed in the hollow portion 33, and thus has a structure more suitable for thinning. Of course, the groove 34 may not be formed in the hollow portion 33 of the bobbin 3 . If there is concern about the positional displacement of the cover 7, the positional displacement may be prevented by adhering the cover 7 to the bobbin 3 or the like.

In the coil component 1 according to the above-described embodiment, the eaves portion 71 of the cover 7 covers the upper side of the binding terminal 41, but a bobbin having a structure in which the binding terminal 41 does not protrude from both front and rear ends of the terminal block 32 is also conceivable. . For example, like the bobbin 203 shown in FIG. 7, the binding terminals 41 project downward from the terminal block 32, and the mounting terminals 42 project forward and backward from the front and rear end surfaces of the terminal block 32, while the tips thereof are downward. For example, when it is bent to Even in such a case, the upper part of the mounting terminal 42 protruding from the terminal block 32 in the front-rear direction may be covered with the eaves part 71 of the cover 7 . In any case, the eaves portion 71 of the cover 7 only needs to cover the terminals 4 projecting forward and rearward from the front and rear end surfaces of the terminal block 32 .

In the coil component 1 according to the above embodiment, the structure of the core 2 is of the EE type.

Although the cover 7 of the coil component 1 according to the embodiment is made of resin having elasticity, it may of course be made of an insulating material having higher rigidity as long as it is of a size that allows insertion into the core 2 .

1,101 coil component, 2 core, 2a, 2b core member,
3, 103, 203 bobbin, 4 terminal, 41 binding terminal, 42 mounting terminal,
5 tape, 6 coil, 7, 8 cover, 21 middle leg of core, 31 winding shaft,
32 terminal block, 33 hollow portion, 71 eaves portion, 72 connection portion, 81 opening, 100 winding shaft

Claims (2)

Assuming that each of the front-rear, left-right, and up-down directions are orthogonal to each other,
A coil component that includes terminals and is mounted on a surface that includes the front-rear and left-right directions,
A coil in which a wire is wound around a longitudinal axis, a core having a middle leg, a bobbin around which the wire is wound, and a cover made of an insulating material attached to the bobbin. prepared,
The bobbin has an opening in the front and the rear, and a terminal block is integrally formed below a hollow cylindrical winding shaft portion on which the winding is wound, and the terminals protrude from the front surface and the rear surface,
The core has the middle leg inserted through the hollow portion of the winding shaft,
The cover is formed in an H shape when viewed from the top and bottom by connecting eaves extending in the left-right direction to front and rear ends of the cover by connecting portions extending in the front-rear direction. configured to be able to be inserted into the
The connection portion is arranged in the hollow portion of the winding shaft portion in a state of being arranged below the middle leg of the core,
When viewed from the front-rear direction, both left and right ends of the eaves portion are bent downward to collectively cover the upper side of the terminal projecting from the terminal block and the left and right sides of the terminals at both the left and right ends.
A coil component characterized by: The coil component according to claim 1,
A groove extending in the front-rear direction is formed in the lower surface of the hollow portion of the winding shaft portion,
wherein the connecting portion is disposed within the groove;
A coil component characterized by:

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