JP2023161330A - Manufacturing method of reactor - Google Patents

Abstract

To provide a manufacturing method of a reactor capable of suppressing crack of a core caused by a resin pressure during molding of a secondary mold resin.SOLUTION: A manufacturing method of a reactor includes the steps of: preparing a pair of cores 10 each having a U-shaped recess 14 and a mold coil 21 in which a cylindrical coil C1 is covered by a primary mold resin R1; assembling the pair of cores 10 and the mold coil 21 by abutting the pair of cores 10 while fitting the mold coil 21 into the recesses 14; and injecting a secondary mold resin R2 to the pair of cores 10 and the mold coils 21 which are assembled. In the prepared mold coil 21, an entire outer side face opposed to the recesses 14 of the pair of cores 10 is not covered by the primary mold resin R1 and the coil C1 is exposed.SELECTED DRAWING: Figure 1

Description

The present disclosure relates to a method for manufacturing a reactor.

A reactor is known in which a core is assembled to a coil, and the coil and core assembly is covered with resin.
For example, Patent Document 1 discloses a reactor manufacturing method including a primary molding process and a secondary molding process. When manufacturing the reactor, a common mold can be used for both primary molding and secondary molding.

Japanese Patent Application Publication No. 2013-149841

In the reactor manufacturing method disclosed in Patent Document 1 mentioned above, during molding of the secondary mold resin, the resin preferentially enters the outer periphery of the core having a U-shaped recess, and the resin acts on the core from the outer periphery. The pressure (resin pressure) increases, and there is a risk that cracks may occur in the core.

The present disclosure has been made in view of these circumstances, and provides a method for manufacturing a reactor that can suppress cracking of the core due to resin pressure during molding of the secondary mold resin.

The method for manufacturing a reactor according to the present disclosure includes:
preparing a molded coil in which a pair of cores having a U-shaped recess and a cylindrical coil are covered with a primary molding resin;
Assembling the pair of cores and the molded coil by butting the pair of cores together while fitting the molded coil into the recess;
injecting a secondary molding resin into the assembled pair of cores and the molded coil,
In the step of injecting, the secondary mold resin is filled into a gap between the recessed portion of the pair of cores and the coil, the method comprising:
In the prepared molded coil, the entire outer surfaces of the pair of cores facing the recesses are not covered with the primary molding resin, and the coil is exposed. be.

In the reactor manufacturing method according to the present disclosure, in the molded coil, the entire outer surface of the pair of cores facing the recessed portions is not covered with the primary molding resin, and the coil is exposed. Therefore, when injecting secondary molding resin into the core and molded coil, the resin is filled preferentially to the inner periphery of the core rather than the outer periphery of the core, and the resin pressure during molding of the secondary molding resin is reduced to the inside. This makes it possible to support the core from the outside, thereby preventing the core from cracking.

In the prepared molded coil, more than half of the end faces of the pair of cores facing the recesses may not be covered with the primary molding resin, and the coil may be exposed. With this configuration, the resin is filled preferentially to the inner circumference of the core rather than the outer circumference of the core, making it possible to support the resin pressure from the inside during molding of the secondary molding resin, and suppressing the core from cracking. can.

In the step of injecting, the core may be supported from the outside. With such a configuration, the secondary mold resin filled in the inner peripheral side of the core can suppress the resin pressure acting from the inside to the outside of the core, and can suppress cracking of the core.

preparing a molded coil in which a pair of cores having a U-shaped recess and a cylindrical coil are covered with a primary molding resin;
Assembling the pair of cores and the molded coil by butting the pair of cores together while fitting the molded coil into the recess;
injecting a secondary molding resin into the assembled pair of cores and the molded coil,
In the step of injecting, the secondary mold resin is filled into a gap between the recessed portion of the pair of cores and the coil, the method comprising:
In the prepared molded coil, more than half of the end faces of the pair of cores facing the recesses are not covered with the primary molding resin, and the coil is exposed. be.

In the reactor manufacturing method according to the present disclosure, in the molded coil, more than half of the end faces of the pair of cores facing the recesses are not covered with the primary molding resin, and the coil is exposed. Therefore, when injecting secondary molding resin into the core and molded coil, the resin is filled preferentially to the inner periphery of the core rather than the outer periphery of the core, and the resin pressure during molding of the secondary molding resin is reduced to the inside. This makes it possible to support the core from the outside, thereby preventing the core from cracking.

According to the present disclosure, it is possible to provide a method for manufacturing a reactor that can suppress cracking of the core due to resin pressure during molding of the secondary mold resin.

1 is a conceptual diagram of a method for manufacturing a reactor according to Embodiment 1. FIG. FIG. 2 is a plan view of a core used in the reactor manufacturing method according to the first embodiment. 3 is a vertical cross-sectional view passing through an opening N1 of the reactor 41 according to the first embodiment. FIG. 3 is a vertical cross-sectional view passing through an opening N2 of the reactor 41 according to the first embodiment. FIG. FIG. 3 is a cross-sectional view showing the internal state of the mold 15 used in the method for manufacturing the reactor 41 according to the first embodiment, that is, the manufactured reactor 41. FIG. It is a figure showing molded coil 20 used for a manufacturing method of a reactor concerning a comparative example concerning a comparative example. FIG. 4 is a vertical cross-sectional view passing through a hole h1 of a reactor 40 according to a comparative example. FIG. 3 is a vertical cross-sectional view passing through an opening N3 of a reactor 40 according to a comparative example. FIG. 3 is a cross-sectional view showing the internal state of a mold 25 used in a method for manufacturing a reactor 40 according to a comparative example, that is, a manufactured reactor 40. It is a schematic diagram which shows three cracking modes of the core 10 used for the manufacturing method of the reactor 40 based on a comparative example. FIG. 7 is a diagram showing the internal and external states of a mold 35 used in the reactor manufacturing method according to Embodiment 2. FIG.

(Embodiment 1)
<Reactor manufacturing method>
Hereinafter, a method for manufacturing a reactor according to Embodiment 1 will be described with reference to the drawings. In each drawing, the same or corresponding elements are denoted by the same reference numerals, and for clarity of explanation, redundant explanation will be omitted as necessary. Also, some symbols are omitted to avoid cluttering the drawings.
Note that, as a matter of course, the right-handed xyz orthogonal coordinates shown in the drawings are for convenience in explaining the positional relationships of the constituent elements. Usually, the positive direction of the z-axis is vertically upward, and the xy plane is a horizontal plane.

FIG. 1 is a conceptual diagram of a method for manufacturing a reactor according to a first embodiment.
First, as shown in FIG. 1, a pair of cores 10 having a U-shaped recess 14 and a molded coil 21 in which a cylindrical coil C1 is covered with a primary molding resin R1 are prepared.
Next, as shown in FIG. 1, while fitting the molded coil 21 into the recess 14 of the core 10, the pair of cores 10 are butted against each other, and the core 10 and the molded coil 21 are assembled.
Then, injection molding is performed so that the assembled core 10 and molded coil 21 are covered with secondary molding resin R2. A reactor is manufactured through the above steps.

Here, with reference to FIG. 1, the molded coil 21 according to the first embodiment will be described. The molded coil 21 includes a coil C1 and a primary mold resin R1 that covers the surfaces (outer surface, inner surface, and both end surfaces) of the coil C1. The coil C1 is a cylindrical conductive member as a whole, and is formed by winding a rectangular wire edgewise. In other words, the coil C1 is made by laminating rectangular wires in the x-axis direction in FIG.

As shown in FIG. 1, the entire outer surface of the molded coil 21 facing the recesses 14 of the pair of cores 10 is not covered with the primary molding resin R1, and the coil C1 is exposed. Further, more than half of the end faces of the pair of cores in the molded coil 21 facing the recessed portions 14 are not covered with the primary molding resin R1, and the coil C1 is exposed. Further, although not particularly limited, in the example shown in FIG. 1, the center portion of the upper surface of the molded coil 21 in the left-right direction (y-axis direction) is not covered with the primary molding resin R1, and the coil C1 is exposed. .

In FIG. 1, more than half of the end surfaces of the pair of cores in the molded coil 21 facing the recessed portions 14 may be covered with the primary molding resin R1.
Furthermore, in FIG. 1, a part of the outer surface of the pair of cores in the molded coil 21 facing the recessed portions 14 may be covered with the primary molding resin R1.

With reference to FIG. 1, the portion of the molded coil 21 that is not covered with the primary mold resin R1, that is, the exposed portion of the coil C1 according to the reactor manufacturing method of the first embodiment will be described in more detail. Here, the end face of the pair of cores in the molded coil 21 facing the recessed part 14 is not covered with the primary molding resin R1, and an opening N1 is formed in which the coil C1 is exposed. In the example shown in FIG. 1, in addition to the opening N1, a hole h1 is formed in the center of the end face in the vertical direction, but the hole h1 does not necessarily need to be formed.

In the example shown in FIG. 1, two openings N1 are formed vertically on the end faces of the pair of cores facing the recesses 14, but the invention is not necessarily limited to this. One or more openings N1 may be formed in the end surface. Furthermore, as shown in FIG. 1, in the end faces of the pair of cores facing the recesses 14, the area of the opening N1 and the hole h1 that is not covered with the primary mold resin R1 occupies more than half of the area.

On the other hand, as shown in FIG. 1, the entire outer surface of the molded coil 21 facing the recesses 14 of the pair of cores is not covered with the primary molding resin R1, and the coil C1 is exposed. That is, the opening N2 is formed on the entire outer surface of the molded coil 21 facing the recesses 14 of the pair of cores. Here, "the whole" does not necessarily mean 100%, but preferably includes 90% or more.

In the molded coil 21, the hole h1, the opening N1, and the opening N2 are provided at symmetrical positions with respect to a plane parallel to the xz plane that includes the central axis of the coil C1. Therefore, in the example shown in FIG. 1, the molded coil 21 is provided with four holes h1, eight openings N1, and two openings N2.

The openings N1 and N2 are formed by injecting the primary mold resin R1 onto the coil C1 while bringing a mold having a shape corresponding to the openings N1 and N2 into contact with the coil C1. At this time, the contact surface between the mold and the coil C1 having a shape corresponding to the openings N1 and N2 is not filled with the primary molding resin R1, so that the openings N1 and N2 are formed.

The primary mold resin R1 is not limited to one molded together with the coil C1 in a mold, and includes one molded separately from the coil C1. For example, the primary mold resin R1 may be injection molded separately from the coil C1 and then assembled to the coil C1.

FIG. 2 is a plan view of a core used in the reactor manufacturing method according to the first embodiment. FIG. 2 shows a pair of cores 10 whose surfaces with recesses 14 are butted against each other. The core 10 includes a base portion 11, a middle leg portion 12, outer leg portions 13a and 13b, and two recesses 14. The pair of cores 10 have a configuration that is plane symmetrical with respect to a butt plane parallel to the yz plane.
The middle leg portions 12 and the outer leg portions 13a and 13b of the pair of butted cores 10 are not in close contact with each other, and a gap is created.

As shown in FIG. 2, the base portion 11 includes a connecting portion 11a that connects the middle leg portion 12 and the outer leg portion 13a, and a connecting portion 11b that connects the middle leg portion 12 and the outer leg portion 13b. ing.

As shown in FIG. 2, the middle leg portion 12 and the outer leg portions 13a and 13b protrude from the base portion 11 in the same direction (x-axis direction). In FIG. 2, the y-axis direction is the longitudinal direction of the base portion 11 and the middle leg portion 12, and the x-axis direction is the longitudinal direction of the outer leg portions 13a and 13b.

As shown in FIG. 2, one of the recesses 14 is surrounded by the middle leg 12, the outer leg 13a, and the connecting part 11a, and has a U-shape in an xy plan view. The other concave portion 14 is similarly formed surrounded by the middle leg portion 12, the outer leg portion 13b, and the connecting portion 11b, and has a U-shape in an xy plan view. Since the core 10 includes two U-shaped recesses 14 in the left-right direction (y-axis direction), it has an E-shaped shape in an xy plan view. When the pair of cores 10 are butted against each other, a rectangular space surrounded by the recesses 14 in the pair of cores 10 is formed in an xy plane view. Therefore, the molded coil 21 can be fitted into the recess 14 of the core 10.

The core 10 has a predetermined thickness in the z-axis direction. The thickness of the core 10 is smaller than the inner diameter in the z-axis direction of the coil C1 in FIG. Therefore, when the molded coil 21 is assembled to the core 10, the middle leg portion 12 is stored inside the molded coil 21. On the other hand, the outer legs 13a and 13b are arranged outside the molded coil 21.

FIG. 3 is a vertical sectional view passing through the opening N1 of the reactor 41 according to the first embodiment. That is, FIG. 3 is a cross-sectional view of the reactor 41 in a plane parallel to the xz plane passing through the opening N1. The reactor 41 includes a core 10, a molded coil 21, and a secondary molded resin R2 covering the core 10 and the molded coil 21. When injection molding the secondary mold resin R2 to the molded coil 21 and the core 10, the molded coil 21 has an opening N1 having a dimension W1 in the height direction (z-axis direction) and an opening N1 having a dimension W1 in the height direction (z-axis direction). ) has a hole h1 having a dimension W3, the secondary molding resin R2 is filled into the gap between the core 10 and the coil C1 through the opening N1 and the hole h1.

FIG. 4 is a vertical cross-sectional view of the reactor 41 according to the first embodiment, passing through the opening N2. That is, FIG. 4 is a cross-sectional view of the reactor 41 in a plane parallel to the yz plane passing through the opening N2. When injection molding the secondary mold resin R2 to the mold coil 20 and the core 10, since the mold coil 21 has an opening N2 having a dimension W2 in the height direction (z-axis direction), the secondary mold resin R2 is filled into the gap between the core 10 and the coil C1 through the opening N2.
Hereinafter, the gap between the core 10 and the coil C1 will be referred to as the inner peripheral side of the core 10, and the opposite side will be referred to as the outer peripheral side of the core 10.

FIG. 5 is a sectional view showing the internal state of the mold 15 used in the method for manufacturing the reactor 41 according to the first embodiment, that is, the manufactured reactor 41. In FIG. 2, the z-axis direction is the height direction. The secondary mold resin R2 is injected, for example, in the negative direction of the z-axis.
A core 10 and a molded coil 21 are inserted into the mold 15. Then, the secondary molding resin R2 is injected into the core 10 and the molded coil 21, and injection molding is performed. During the injection molding process of the secondary mold resin R2, a hole h2, which is an insertion hole for a bolt or the like, is also formed in the flange portion for attachment.

Referring to FIG. 5, the resin flow path in the injection molding process of the secondary mold resin R2 will be described. The resin flow paths of the secondary mold resin R2 include inner flow paths 31a and 31b passing through the inner circumference of the core 10, an outer flow path 32 passing through the outer circumference of the core 10, and a flow passing between the pair of cores 10. 33. The inner flow paths 31a, 31b, the outer flow path 32, and the flow path 33 are continuous flow paths without interruption. Since the molded coil 21 has the opening N1 and the opening N2, the inner channels 31a and 31b are filled with the secondary mold resin R2 preferentially than the outer channel 32.

<Method for manufacturing reactor according to comparative example>
Next, a method for manufacturing a reactor according to a comparative example will be described with reference to the drawings. The method for manufacturing the reactor according to the comparative example is similar to the method for manufacturing the reactor according to the first embodiment, by fitting the molded coil 20 into the recess 14 of the core 10 and butting the pair of cores 10 against each other. Assemble. Then, the reactor is manufactured by injection molding the secondary mold resin R2 onto the core 10 and the molded coil 20.
Hereinafter, a description will be given focusing on the differences from the reactor manufacturing method according to the first embodiment described above, that is, the molded coil 20.

FIG. 6 is a diagram showing a molded coil 20 used in a method for manufacturing a reactor according to a comparative example. The molded coil 20 in FIG. 6 and the molded coil 21 in FIG. 1 differ in the portion covered with the primary molding resin R1. Here, with reference to FIG. 6, a portion of the molded coil 20 that is not covered with the primary molding resin R1, that is, an exposed portion of the coil C1 will be described.

The molded coil 20 includes a coil C1 and a primary mold resin R1 that covers the coil C1. The upper and lower sides of the outer surfaces of the molded coil 20 facing the recesses 14 of the pair of cores are covered with the primary molding resin R1, and the coil C1 is exposed at the center in the vertical direction (z-axis direction). In other words, the opening N3 is provided at the center of the outer surfaces of the pair of cores that face the recesses 14.

On the other hand, the end faces of the pair of cores in the molded coil 20 that face the recesses 14 are covered with the primary mold resin R1 except for the holes h1 on the end faces. In the example shown in FIG. 1, three holes h1 are formed side by side in the vertical direction (z-axis direction), but the central hole h1 in the vertical direction does not necessarily need to be provided.

In the molded coil 20 shown in FIG. 6, the area of the hole h1 that is not covered with the primary molding resin R1 is less than half of the area of the hole h1 that is not covered with the primary molding resin R1 on the end faces of the pair of cores facing the recessed portions 14.

On the other hand, the opening N3 in the molded coil 20 shown in FIG. 6 is smaller than the opening N2 in the molded coil 21 shown in FIG. In other words, in the molded coil 21 shown in FIG. 1, the entire outer surfaces of the pair of cores facing the recesses 14 are not covered with the primary molding resin R1. In contrast, in the molded coil 20 shown in FIG. 6, a portion of the outer surfaces of the pair of cores facing the recesses 14 are covered with the primary molding resin R1.

FIG. 7 is a vertical sectional view passing through the hole h1 of the reactor 40 according to the comparative example. The reactor 40 includes a core 10, a molded coil 20, and a secondary molded resin R2. Molded coil 20 and core 10 are covered with secondary molding resin R2. When injection molding the secondary mold resin R2 to the mold coil 20 and the core 10, the mold coil 20 has a hole h1 having a dimension W3 in the height direction (z-axis direction), so the secondary mold resin R2 The gap between the core 10 and the coil C1 is filled through the hole h1.

FIG. 8 is a vertical cross-sectional view passing through the opening N3 of the reactor 40 according to the comparative example. When injection molding the secondary mold resin R2 to the mold coil 20 and the core 10, the mold coil 20 has an opening N3 having a dimension W4 in the height direction (z-axis direction), so the secondary mold resin R2 is filled into the gap between the core 10 and the coil C1 through the opening N3.

FIG. 9 is a sectional view showing the internal state of the mold 25 used in the method for manufacturing a reactor 40 according to a comparative example, that is, the manufactured reactor 40. The core 10 and the molded coil 20 are inserted into the mold 25. Then, the secondary molding resin R2 is injected into the core 10 and the molded coil 20, and injection molding is performed. At this time, most of the outer surfaces and end surfaces of the pair of cores in the molded coil 20 facing the recessed portions 14 are covered with the primary resin mold R1. The covering portion formed by the primary resin mold R1 prevents the inner channels 31a and 31b from being filled with the secondary mold resin R2. Therefore, in the mold 25, the outer flow path 32 is preferentially filled with the secondary mold resin R2 than the inner flow paths 31a and 31b. Therefore, the core 10 in FIG. 9 is pressurized by the resin pressure of the secondary molding resin R2 from the outside to the inside as shown by the arrow, causing a problem that the core 10 will crack.

Here, with reference to FIG. 2, the damaged portion of the core 10 will be explained. In the core 10, the width of the outer legs 13a and 13b in the y-axis direction is narrower than the width of the middle leg 12 in the y-axis direction. Further, the width of the connecting portions 11a and 11b in the x-axis direction is narrower than the width of the middle leg portion 12 in the x-axis direction. When manufacturing a reactor with a smaller size, the outer legs 13a, 13b and the connecting parts 11a, 11b become thinner, and there is a possibility that the outer legs 13a, 13b and the connecting parts 11a, 11b will break during molding. There is.

In order to prevent the core 10 from cracking, the inventors investigated the cracking mode of the core 10 by changing the dimensions of the inner channels 31a, 31b, the outer channels 32, and the channels 33. FIG. 10 is a schematic diagram showing three cracking modes of the core 10 used in the method for manufacturing the reactor 40 according to the comparative example. Mode 1 occurs when the secondary mold resin R2 is filled from the outer flow path 32 first. In mode 1, the outer legs 13a and 13b are pressurized by the secondary mold resin R2 in the y-axis direction as shown by the arrow, and high stress is generated in the region X1. A possible cause of mode 1 is that there is no support mechanism inside the outer legs 13a and 13b.

Mode 2 also occurs when the secondary mold resin R2 resin is filled from the outer flow path 32 first. In mode 2, the connecting portions 11a and 11b are pressurized in the x-axis direction as shown by the arrow, and high stress is generated at the portion X2. A possible cause of mode 2 is that there is no support mechanism inside the connecting portions 11a and 11b.

Mode 3 occurs when the secondary mold resin R2 resin is filled from the upper side of the core 10 first. In mode 3, the core 10 is pressurized downward as indicated by the arrow, and high stress is generated at the portion X3. A possible cause of mode 3 is that there is no support mechanism below the core 10 (for example, on the negative side of the z-axis).

From the above study, it is considered that cracking of the core 10 can be prevented by preferentially filling the inner channels 31a and 31b with the secondary molding resin R2 than the outer channel 32.

<Effects of the reactor manufacturing method according to Embodiment 1>
Next, the effects of the reactor manufacturing method according to the first embodiment will be explained.
Comparing the dimension W1 of the opening N1 in the molded coil 21 in FIG. 3 and the dimension W3 of the hole h1 in the molded coil 20 in FIG. 8, the dimension W1 of the opening N1 is larger than the dimension W3 of the hole h1. big. Therefore, in the reactor manufacturing method according to the first embodiment, the secondary molding resin R2 is preferentially filled on the inner circumferential side of the core 10 than on the outer circumferential side of the core 10.

Comparing the dimension W2 of the opening N2 in the molded coil 21 in FIG. 4 with the dimension W4 of the opening N3 in the molded coil 20 in FIG. It is larger than the dimension W4 of the opening N3 in 20. Therefore, in the reactor manufacturing method according to the first embodiment, the secondary molding resin R2 is preferentially filled on the inner circumferential side of the core 10 than on the outer circumferential side of the core 10.

Comparing the molded coil 21 shown in FIG. 5 and the molded coil 20 shown in FIG. 9, the molded coil 21 shown in FIG. 5 has an opening N1 and an opening N2. Therefore, when the molded coil 21 shown in FIG. 5 is used, the filling of the secondary molded resin R2 into the inner channels 31a and 31b is less likely to be inhibited, compared to the case where the molded coil 20 shown in FIG. 9 is used. In other words, when the molded coil 21 shown in FIG. 5 is used, the inner channels 31a and 31b are filled with the secondary mold resin R2 preferentially than the outer channel 32. Therefore, the resin pressure of the secondary mold resin R2 in injection molding can be applied from the inside to the outside as shown by the arrow in FIG. 5, and cracking of the core 10 can be suppressed.

As described above, the method for manufacturing a reactor according to the first embodiment is such that the entire outer surface of the molded coil 21 facing the recess 14 of the pair of cores 10 or more than half of the end surface facing the recess 14 of the pair of cores 10 However, the coil C1 is not covered with the primary mold resin R1, and the coil C1 is exposed. Therefore, when injecting the secondary mold resin R2 into the core 10 and the molded coil 21, the resin is preferentially filled into the core inner circumference side than the core outer circumference side, and when the secondary mold resin R2 is molded. It becomes possible to support the resin pressure from the inside, and it is possible to suppress cracking of the core 10.

(Embodiment 2)
Next, with reference to FIG. 11, a method for manufacturing a reactor according to the second embodiment will be described.
The method for manufacturing a reactor according to the second embodiment differs from the method for manufacturing a reactor according to the first embodiment in the mold used for manufacturing the reactor. FIG. 11 is a diagram showing the inside and outside states of the mold 35 used in the reactor manufacturing method according to the second embodiment. The internal structure of the mold 35 is the same as that of the mold 25 according to the first embodiment, so a description thereof will be omitted. Here, core support pins 16a, 16b, 16c, 16d, 16e, 16f, and 16g will be explained.

The mold 35 includes core support pins 16a, 16b, 16c, 16d, 16e, 16f, and 16g. The mold 35 may further include a hydraulic device (not shown) that controls the position and pressure of the core support pins 16a, 16b, 16c, 16d, 16e, 16f, and 16g.

The core support pins 16a, 16b, 16c, 16d, 16e, 16f, and 16g are provided on the outer peripheral side of the core 10 so as to support the pair of cores 10 from the outside. The core support pins 16a, 16b, 16c, 16d, 16e, 16f, and 16g have a predetermined thickness (y-axis direction), depth (x-axis direction), and height enough to support the pair of cores 10 from the outside. (z-axis direction).

The core support pins 16f and 16g are provided at positions facing the opening N1 in the molded coil 21 via the connecting portions 11a and 11b. In the example shown in FIG. 11, the core support pins 16f and 16g support only one side of the core 10 because they have flanges with holes h2 that are insertion holes for mounting bolts and the like.

Further, the core support pins 16a, 16b, 16c, and 16d are provided at positions facing the opening N2 in the molded coil 21 via the outer leg portions 13a and 13b. That is, core support pins 16a, 16b, 16c, 16d, 16f, and 16g are provided at positions facing openings N1 and N2 in molded coil 21 via core 10.

Note that some of the core support pins 16e may not be arranged at positions facing the openings N1 and N2. In the example shown in FIG. 11, the core support pin 16e is provided between flanges having holes h2. The positions of the core support pins 16a, 16b, 16c, 16d, 16e, 16f, and 16g in the height direction (z-axis direction) are preferably the same in order to evenly support the core 10 from the outside.

When the secondary mold resin R2 is injected into the core 10 and the molded coil 21, the parts where the core 10 and the core support pins 16a, 16b, 16c, 16d, 16e, 16f, and 16g are in contact are filled with secondary resin. Since mold resin R2 is not filled, openings corresponding to the shapes of core support pins 16a, 16b, 16c, 16d, 16e, 16f, and 16g are formed in the manufactured reactor.

Here, if the secondary mold resin R2 is injected into the core 10 and the molded coil 21 at a high injection speed, the core 10 will be injected to the outside as shown by the arrows in the x-axis direction and the y-axis direction in FIG. It is pressurized by the resin pressure of the secondary molding resin R2 acting toward the cylinder. Therefore, there is a possibility that the outer leg portions 13a and 13b or the connecting portions 11a and 11b may break due to the resin pressure of the secondary mold resin R2 that is preferentially filled on the inner peripheral side of the core.

The core support pins 16a, 16b, 16c, and 16d support the outer legs 13a and 13b from the outside, and control the resin pressure shown by the arrow in the y-axis direction that is applied when injection molding the secondary mold resin R2. suppress. The core support pins 16e, 16f, and 16g support the connecting portions 11a and 11b from the outside, and suppress the resin pressure shown by the arrow in the x-axis direction that is applied when injection molding the secondary mold resin R2. That is, the core support pins 16a, 16b, 16c, 16d, 16e, 16f, and 16g support the core 10 from the outside while contacting the core 10, so that the secondary mold resin R2 preferentially flows into the inner channels 31a and 31b. The resin pressure acting from the inside to the outside of the core 10 when being filled is suppressed.

Note that the mold 35 may include a hydraulic device (not shown) that controls the pressure of the core support pins 16a, 16b, 16c, 16d, 16e, 16f, and 16g. , 16d, 16e, 16f, and 16g to suppress the resin pressure of the secondary mold resin R2 is the resin pressure acting from the inside to the outside of the core 10 that changes according to the injection speed of the secondary mold resin R2. It can be controlled according to the

In this manner, the reactor manufacturing method according to the second embodiment includes core support pins 16a, 16b, 16c, 16d, 16e, 16f, and 16g that support the core 10 from the outside. Therefore, the secondary mold resin R2 filled in the inner peripheral side of the core can suppress the resin pressure acting from the inside to the outside of the core 10, and can suppress the core 10 from cracking.

Note that the present disclosure is not limited to the above embodiments, and can be modified as appropriate without departing from the spirit.

10 Core 11 Base part 11a, 11b Connection part 12 Middle leg part 13a, 13b Outer leg part 14 Recessed part 15, 25, 35 Mold 16a, 16b, 16c, 16d, 16e, 16f, 16g Core support pin 20, 21 Molded coil 31a, 31b Inner channel 32 Outer channel 33 Channels 40, 41 Reactor C1 Coil h1, h2 Hole N1, N2, N3 Opening R1 Primary mold resin R2 Secondary mold resin X1, X2, X3 Part

Claims (4)

preparing a molded coil in which a pair of cores having a U-shaped recess and a cylindrical coil are covered with a primary molding resin;
Assembling the pair of cores and the molded coil by butting the pair of cores together while fitting the molded coil into the recess;
injecting a secondary molding resin into the assembled pair of cores and the molded coil,
In the step of injecting, the secondary mold resin is filled into a gap between the recessed portion of the pair of cores and the coil, the method comprising:
In the prepared molded coil, the entire outer surfaces of the pair of cores facing the recesses are not covered with the primary molding resin, and the coil is exposed.
How to manufacture a reactor. In the prepared molded coil, more than half of the end surfaces of the pair of cores facing the recessed portions are not covered with the primary molding resin, and the coil is exposed.
A method for manufacturing a reactor according to claim 1. supporting the core from the outside in the injection step;
A method for manufacturing a reactor according to claim 1 or 2. preparing a molded coil in which a pair of cores having a U-shaped recess and a cylindrical coil are covered with a primary molding resin;
Assembling the pair of cores and the molded coil by butting the pair of cores together while fitting the molded coil into the recess;
injecting a secondary molding resin into the assembled pair of cores and the molded coil,
In the step of injecting, the secondary mold resin is filled into a gap between the recessed portion of the pair of cores and the coil, the method comprising:
In the prepared molded coil, more than half of the end surfaces of the pair of cores facing the recessed portions are not covered with the primary molding resin, and the coil is exposed.
How to manufacture a reactor.

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