JP6277852B2 - Reactor - Google Patents

Description

  The present invention relates to a reactor having a core made of a magnetic powder mixed resin.

Some reactors have a core made of a magnetic powder mixed resin, a coil formed by winding a conductor wire, and a case in which the core and the coil are accommodated inside (Patent Document 1).
In such a reactor, it is required that the core and the coil be fixed and the core and the case be fixed securely. And these fixation is implement | achieved when the resin in the magnetic powder mixed resin which comprises a core closely_contact | adheres to a coil or a case.

JP 2006-4957 A

  However, if the close contact between the core and the lead portion of the coil or the close contact between the core and the case inner surface is insufficient near the core surface, the core and the lead portion or the case are peeled off from that point. There is also concern about inviting. Therefore, securing the close contact between the core and the lead portion or the case near the core surface is important for ensuring the durability of the reactor.

  This invention is made | formed in view of this background, and aims to provide the reactor excellent in durability.

One embodiment of the present invention includes a coil that generates magnetic flux when energized;
A core made of a magnetic powder mixed resin obtained by mixing a resin and magnetic powder and having the coil embedded therein;
A reactor comprising a case that houses the coil and the core inside,
The coil has a winding part and a lead part that is drawn from the winding part and includes a terminal part,
The drawer portion protrudes from the core surface of the core,
The resin constituting the magnetic powder mixed resin is formed so as to crawl up along the lead-out part or the case inner surface at a portion where at least one of the lead-out part and the case inner surface of the case intersects the core surface. and have a resin creep-up portion,
The resin scooping portion is in a reactor characterized by being substantially made only of the resin and not containing the magnetic powder .

  The reactor has the resin scooping-up portion at a portion where at least one of the drawer portion and the inner surface of the case intersects the core surface. Thereby, the adhesiveness between a core and any one of a drawer | drawing-out part and a case inner surface can be improved. That is, the fixing between the core and the coil and the fixing between the core and the case are realized by the resin in the magnetic powder mixed resin constituting the core being in close contact with the coil and the case. From the viewpoint of durability, adhesion in the vicinity of the core surface is important for fixing the core and the coil and fixing the core and the case.

  As described above, the reactor includes a resin scooping portion made of resin at a portion where at least one of the drawer portion and the case inner surface intersects the core surface. Therefore, it is possible to effectively improve the adhesion between the core and any one of the lead portion and the case inner surface. Thereby, at least one of the fixing force between the core and the coil and the fixing force between the core and the case can be improved. As a result, a reactor excellent in durability can be obtained.

  As described above, according to the present invention, a reactor having excellent durability can be provided.

Sectional explanatory drawing along the axial direction of the reactor in Example 1. FIG. Sectional explanatory drawing seen from the axial direction of the reactor in Example 1. FIG. Sectional explanatory drawing of the resin scooping up part around the drawer | drawing-out part in Example 1. FIG. FIG. 3 is a plan explanatory view of a resin scooping up portion around the drawer portion in the first embodiment. Sectional explanatory drawing of the resin scooping up part near the case inner surface in Example 1. FIG. In Example 1, (a) explanatory diagram of the step of arranging the coil and magnetic powder in the case, (b) explanatory diagram of the step of impregnating the magnetic powder arranged in the case with resin, (c) the magnetic powder Explanatory drawing of the state after impregnating resin. Cross-sectional explanatory drawing of the scooping part containing magnetic powder. Sectional explanatory drawing of the resin scooping up part in Example 1. FIG. Cross-sectional explanatory drawing along the axial direction of the reactor in Example 2. FIG. Cross-sectional explanatory drawing seen from the axial direction of the reactor in Example 2. FIG.

The resin creep-up portion is constituted by a resin in the magnetic powder mixed resin, the magnetic powder is not not contain substantially. However, the resin scooping-up portion may contain a slight amount of magnetic powder with a sufficiently low filling rate as compared with other portions (general portion) in the core.

  Further, the portion where the lead portion and the core surface intersect means the vicinity of the portion where the extended surface of the core surface and the lead portion intersect, and the portion where the case inner surface and the core surface intersect refers to the extended surface of the core surface. It means the vicinity of the part where the case inner surface intersects.

  Moreover, it is preferable that the said resin scooping-up part is formed in the site | part where the said drawer | drawing-out part and the said core surface cross | intersect at least. In this case, the fixing force between the core and the coil can be improved. Further, when the coil is embedded in the core made of the magnetic powder mixed resin, the rising portion of the magnetic powder mixed resin is likely to be formed at the portion where the drawn portion and the core surface intersect due to surface tension. If this scooping portion contains magnetic powder as in other parts of the core, the creepage distance between the terminal portion and the core will be shortened by the length of the scooping portion. On the other hand, if the scooping-up portion is the resin scooping-up portion made of resin, this portion can be substantially regarded as an insulator, so that the creeping distance between the terminal portion and the core can be increased. As a result, it is not necessary to keep the position of the terminal part in the lead-out part away from the core surface, and the entire reactor can be downsized.

Example 1
Examples of the reactor will be described with reference to FIGS.
As shown in FIGS. 1 and 2, the reactor 1 of this example includes a coil 2 that generates a magnetic flux when energized, a core 3 in which the coil 2 is embedded, and a case that accommodates the coil 2 and the core 3 inside. It consists of four. As shown in FIG. 3, the core 3 is made of a magnetic powder mixed resin 30 in which a resin 32 and a magnetic powder 33 are mixed.

As shown in FIGS. 1 and 2, the coil 2 includes a winding part 21 and a lead part 22 that is drawn from the winding part 21 and includes a terminal part 221. The lead-out portion 22 protrudes from the core surface 31 of the core 3.
In the reactor 1, the resin 32 constituting the magnetic powder mixed resin 30 crawls along the drawer portion 22 or the case inner surface 41 at a portion where the core surface 31 intersects at least one of the drawer portion 22 and the case inner surface 41 of the case 4. It has the resin scooping-up part 5 formed so that it may go up.

  In this example, the resin scooping-up portion 5 is formed at both the portion where the lead-out portion 22 and the core surface 31 intersect and the portion where the case inner surface 41 and the core surface 31 intersect. That is, in this example, as the resin scooping portion 5, the resin scooping portion 51 formed so that the resin 32 scoops up along the lead-out portion 22, and the resin 32 scoops up along the case inner surface 41. And a formed resin scooping portion 52.

  The coil 2 is formed by winding a conductor wire made of copper (Cu) to form a winding portion 21 and drawing both ends of the conductor wire from the winding portion 21 to form a lead-out portion 22. . The conductor wire is a flat conductive wire having a rectangular cross-section perpendicular to the longitudinal direction, and an insulating coating 224 is formed on the surface thereof. The leading end portion of the lead portion 22 is exposed from the insulating coating 224, and this portion becomes the terminal portion 221.

  The coil 2 includes two lead portions 22, and the two lead portions 22 protrude from the core surface 31. The terminal portion 221 is disposed outside the core 3, and the core surface 31 intersects the lead portion 22 at a portion where the insulating coating 224 is formed in the lead portion 22.

  The case 4 is made of a nonmagnetic metal such as aluminum. As shown in FIGS. 1 and 2, the case 4 includes a substantially cylindrical side wall portion 42 and a bottom wall portion 43 that closes one end side of the side wall portion 42. And the surface on the opposite side to the bottom wall part 43 in case 4 is open | released, and the core surface 31 is formed in this open surface side.

  The magnetic powder mixed resin 30 constituting the core 3 uses an epoxy resin as the resin 32 and iron powder as the magnetic powder 33, and these are mixed. The filling rate (content rate) of the magnetic powder 33 in the magnetic powder mixed resin 30 is, for example, 73 to 75% by volume, and the content rate of the resin 32 is, for example, 25 to 27% by volume. In the core 3, the magnetic powder 33 is arranged substantially evenly in the resin 32 except for the resin scooping-up portion 5.

  However, as shown in FIGS. 3 and 5, the resin scooping portion 5 is substantially composed of only the resin 32, and does not include the magnetic powder 33. Moreover, the resin scooping-up part 5 is the scooping height, ie, the protrusion direction of the drawer | drawing-out part 22, and the height in the standing direction of the side wall part 42 of case 4 is 1-3 mm, for example.

Further, the resin scooping-up portion 5 is formed in a concave shape with respect to the outside of the core surface 31.
Moreover, since the conductor wire which comprises the coil 2 is a rectangular conducting wire as mentioned above, as shown in FIG. 4, the drawer | drawing-out part 22 consists of a rectangular conducting wire whose cross-sectional shape orthogonal to a longitudinal direction is a rectangular shape. The resin scooping up portion 51 is formed so as to face at least the long side 222 of the lead-out portion 22. In this example, even when facing the short side 223 of the lead-out portion 22, the resin scooping-up portion 51 is formed.
Further, as shown in FIG. 2, the resin scooping portion 52 is formed over the entire circumference of the case inner surface 41 even at a position where the case inner surface 41 and the core surface 31 intersect.

In manufacturing the reactor 1, for example, the following procedure is performed.
First, as shown in FIG. 6A, after the coil 2 is placed at a predetermined position in the case 4, a predetermined amount of magnetic powder 33 is placed in the case 4. Next, the case 4 containing the coil 2 and the magnetic powder 33 is placed in a vacuum chamber (not shown) and the pressure is reduced to 1000 Pa. Under reduced pressure, as shown in FIG. 6B, a predetermined amount of liquid resin 32 is poured onto the aggregate of the magnetic powder 33 in the case 4 by the dropping funnel 71. Thereafter, the inside of the vacuum chamber is returned to atmospheric pressure, and the aggregate of the magnetic powder 33 is impregnated with the resin 32 by atmospheric pressure. As a result, as shown in FIG. 6C, the magnetic powder mixed resin 30 in a state where the aggregate of the magnetic powder 33 is dispersed and encapsulated in the insulating resin 32 is produced in the case 4. In this state, the lead-out portion 22 of the coil 2 protrudes from the magnetic powder mixed resin 30.

  Thereafter, the magnetic powder mixed resin 30 is heated together with the case 4 and the coil 2 to cure the magnetic powder mixed resin 30. Thereby, as shown in FIG. 1, the core 3 which embedded the coil 2 inside is formed, and the reactor 1 is obtained. The core surface 31 intersects the case inner surface 41 and the pair of coil terminals 22. And the resin scooping-up part 5 (51, 52) is formed in these parts.

  The resin scooping portion 5 is formed by the surface tension of the resin 32, and the shape thereof is determined based on the contact angle with the drawing portion 22 or the case 4. For example, when the resin 32 is epoxy and the insulating coating 224 that forms the surface of the lead-out portion 22 is polyamideimide, the resin scooping-up portion 51 has a concave shape on the outside of the core surface 31 as shown in FIG. It becomes a shape. Further, when the resin 32 is made of epoxy and the case 3 is made of aluminum, similarly, as shown in FIG. 5, the resin scooping portion 52 has a concave shape outside the core surface 31.

Next, the function and effect of this example will be described.
The reactor 1 has a resin scooping-up portion 5 at a portion where the drawing portion 22 and the case inner surface 41 and the core surface 31 intersect. Thereby, the adhesiveness between the core 3 and the drawer | drawing-out part 22 and the case inner surface 41 can be improved. That is, the fixing between the core 3 and the coil 2 and the fixing between the core 3 and the case 4 are such that the resin 32 in the magnetic powder mixed resin 30 constituting the core 3 is in close contact with the coil 3 and the case 4. It is realized by. From the viewpoint of durability, the adhesiveness in the vicinity of the core surface 31 is important for fixing the core 3 and the coil 2 and fixing the core 3 and the case 4.

  As described above, the reactor 1 includes the resin scooping portion 5 made of the resin 32 at a portion where the lead portion 22 and the case inner surface 41 intersect with the core surface 31. Therefore, it is possible to effectively improve the adhesion between the core 3 and the lead portion 22 and the case inner surface 41. Thereby, the fixing force between the core 3 and the coil 2 and the fixing force between the core 3 and the case 4 can be improved. As a result, the reactor 1 excellent in durability can be obtained.

  Moreover, since the resin scooping-up part 51 is formed in the site | part where the drawer | drawing-out part 22 and the core surface 31 cross, it becomes easy to ensure the creeping distance between the terminal part 221 of the coil 2, and the core 3. FIG. That is, when the coil 2 is embedded in the core 3 made of the magnetic powder mixed resin 30, the rising portion of the magnetic powder mixed resin 30 is easily formed at the portion where the lead-out portion 22 and the core surface 31 intersect due to surface tension. . As shown in FIG. 7, if the creeping portion 95 contains the magnetic powder 33 in the same manner as other portions of the core 3, the creepage distance between the terminal portion 221 and the core 3 rises. The portion 95 is shortened by the length L. On the other hand, as shown in FIG. 8, if the scooping-up portion is a resin scooping-up portion 5 made of the resin 32, this portion can be substantially regarded as an insulator, so that the portion between the terminal portion 221 and the core 3 can be considered. The creepage distance can be earned for the length L. As a result, the position of the terminal portion 221 in the lead-out portion 22 does not need to be moved away from the core surface 31, and the reactor 1 as a whole can be downsized.

  Further, the resin scooping up portion 51 is formed so as to face at least the long side 222 of the lead-out portion 22. Thereby, since the resin scooping up part 51 will support the drawer | drawing-out part 22 from the thickness direction, a deformation | transformation of the drawer | drawing-out part 22 can be suppressed and the positional accuracy of the terminal part 221 can be improved.

  As described above, according to this example, a reactor having excellent durability can be provided.

(Example 2)
As shown in FIGS. 9 and 10, this example is an example of a reactor 1 including a case 4 having a core portion 44 standing inside from a bottom wall portion 43.
The middle core portion 44 is formed so as to be erected from the center of the bottom wall portion 43 to the same side as the erection direction of the side wall portion 42. The core portion 44 is disposed on the inner peripheral side of the coil 2.

  In the case of this example, the case 4 has a space for accommodating the coil 2 and the core 3 between the bottom wall portion 43, the side wall portion 42, and the center core portion 44. Therefore, as the case inner surface 41, in addition to the inner surface 421 of the side wall portion 42, an outer peripheral surface 441 of the center core portion 44 also exists. The resin scooping-up portion 5 (53) is also formed at a portion where the outer peripheral surface 441 of the core portion 44, which is a part of the case inner surface 41, and the core surface 31 intersect.

  Others are the same as in the first embodiment. Of the reference numerals used in this example or the drawings relating to this example, the same reference numerals as those used in the first embodiment denote the same components as in the first embodiment unless otherwise specified.

  In the case of this example, since the resin scooping portion 53 is also formed at the portion where the outer peripheral surface 441 of the core portion 44 and the core surface 31 intersect, the adhesion between the case 4 and the core 3 is further improved. Will be improved. In addition, the same effects as those of the first embodiment are obtained.

  In addition, this invention is not restricted to the structure shown in the said Example, A various aspect can be taken. For example, in the said Example, although the protrusion direction of the extraction | drawer part 22 from the core surface 31 and the axial direction of the coil 2 (winding part 21) were shown as the same direction, the axial direction of the coil 2 was shown. It can also be set as the aspect made into the direction orthogonal to the protrusion direction of the drawer | drawing-out part 22 from the core surface 31. FIG.

DESCRIPTION OF SYMBOLS 1 Reactor 2 Coil 21 Winding part 22 Pull-out part 221 Terminal part 3 Core 30 Magnetic powder mixed resin 31 Core surface 32 Resin 33 Magnetic powder 4 Case 41 Case inner surface 5, 51, 52, 53 Resin rising part

Claims (4)

A coil (2) that generates magnetic flux when energized;
A core (3) comprising a magnetic powder mixed resin (30) obtained by mixing a resin (32) and a magnetic powder (33) and having the coil (2) embedded therein;
A reactor (1) comprising a case (4) for accommodating the coil (2) and the core (3) inside;
The coil (2) has a winding part (21) and a lead part (22) that is drawn from the winding part (21) and has a terminal part,
The lead-out part (22) protrudes from the core surface (31) of the core (3),
The resin (32) constituting the magnetic powder mixed resin (30) is provided at a portion where at least one of the lead portion (22) and the case inner surface (41) of the case (4) intersects the core surface (31). ) is closed the lead portion (22) or high up so formed resin wicking portion along the inner surface of the case (41) and (5,51,52,53),
The reactor (1) characterized in that the resin scooping part (5, 51, 52, 53) is substantially composed only of the resin (32) and does not contain the magnetic powder (33 ).   The reactor (1) according to claim 1, wherein the resin scooping-up portion (5, 51) is formed at a portion where at least the lead-out portion (22) and the core surface (31) intersect. .   The lead-out portion (22) is a flat conductive wire having a rectangular cross-section perpendicular to the longitudinal direction, and the resin scooping-up portion (5, 51) is at least the long side (222) in the lead-out portion (22). The reactor (1) according to claim 2, wherein the reactor (1) is formed facing the above.   The said resin scooping up part (5, 52, 53) is formed in the site | part which the said case inner surface (41) and the said core surface (31) cross at least. The reactor (1) according to one item.

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