JP2015005579A - Reactor and manufacturing method for reactor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a reactor that has satisfactory magnetic characteristics without degrading the characteristics even in a case where a core has a slide face formed by sliding over a die, and to provide a manufacturing method for it.SOLUTION: A reactor comprises: a plurality of leg parts 11; a core part 10 formed from a pair of yoke parts 12 connecting both ends of each of the leg parts 11; and a coil 20 attached to at least part of the core part 10. The leg parts 11 and yoke parts 12 are composed of compressed powder magnetic core obtained by press molding soft magnetic powder. Each yoke part 12 has a substantially flat face formed by pressing, and a slide face formed by sliding over a die. The substantially flat face includes a face 12a connected to the leg parts 11. Each yoke part 12 is arranged such that the face 12a connected to the leg part 11 is orthogonal to the direction of the shaft around which coil 20 is wound.

Description

  The present invention relates to a reactor including a core constituted by a dust core and a method for manufacturing the same.

  Reactors are used in various applications including drive systems for hybrid vehicles and electric vehicles. The reactor basically has an annular core composed of a pair of leg portions and a yoke portion connecting both ends thereof, and a pair of coils wound around each of the pair of leg portions. Recently, since a large current is superimposed, it has become mainstream to produce a core using a dust core.

  As a core using this type of powder magnetic core, for example, a core shown in Patent Document 1 is known. This core is a U-shaped core formed by press-molding soft magnetic powder to produce a block-shaped split core, and connecting a plurality of these split cores in an I-shape to form legs. The yoke part is composed of In this dust core, iron powder, alloys such as Sendust, amorphous alloy powder, etc. are used as the soft magnetic powder. In order to ensure the strength and magnetic properties of the core, the surface of the soft magnetic powder is insulated. It is common to form a coating.

Japanese Patent No. 4465635

  The powder magnetic core as described above is configured by filling soft magnetic powder in a mold and pressing it at a high pressure. Therefore, when molding is completed, the mold surface and the surface of the molded core are Touching with strong force. Therefore, when the core molded from the mold is taken out, if the core surface and the mold surface slide, the surface of the core is rubbed strongly, and the insulating coating formed on the surface of the soft magnetic powder in that portion The phenomenon of being scraped off occurs. When the insulating film of soft magnetic powder is lost, the soft magnetic powders are in direct contact with each other, and a thin metal layer is formed on the surface of the core, and eddy current loss occurs in that part due to the magnetic flux passing through the core. In addition, the loss of the reactor increases.

  In order to solve such problems, it is possible to reduce the loss by cutting or etching the connection surface damaged by sliding, but this increases the number of process steps and the production cost. This was not desirable from the viewpoint of mass productivity.

  On the other hand, when the molded core is taken out, the portion that does not slide with the mold surface, specifically, the surface of the core that is perpendicular to the direction of taking out from the mold, Since only the surface is crimped, such a problem does not occur. Therefore, when creating an annular core by connecting a plurality of cores, the magnetic flux passing through the annular core can be obtained by using a surface that does not slide with the mold surface as a connection surface with another core. It is preferable not to pass through the sliding surface.

  In this case, since the entire split core constituting the I-shaped core is substantially cubic or rectangular parallelepiped, it can be pressed from either direction of the core and can be taken out. However, as shown in FIG. 8, the U-shaped core constituting the yoke portion has both ends of the core projecting from the central portion, so that the thickness direction of the U-shaped core (I-shape formed at both ends of the core) From the direction parallel to the connecting surface 101 with the mold core, pressing and taking out the mold must be performed. Temporarily, in order to press the U-shaped core from the direction orthogonal to the connecting surface 101 with the I-shaped core, it is necessary to use a convex mold protruding from the center, and the soft mold filled in the mold is used. The pressure applied to the magnetic powder differs between the central protrusion and its surroundings, and the density of the molded core becomes uneven at each part, leading to a decrease in the magnetic characteristics of the reactor.

  As described above, the U-shaped core constituting the yoke portion is formed with respect to the upper and lower surfaces (the U-shaped surface) of the U-shaped core having a flat shape for the purpose of uniform density and the like. Since pressing was performed from the thickness direction of the letter-shaped core, there were the following problems. That is, the produced U-shaped core is insert-molded with respect to the resin-made coil bobbin, and then the I-shaped core is inserted into the coil bobbin, and the coil is mounted on the outer periphery of the coil bobbin. It is formed. The reactor body is fixed in an aluminum case. At the time of insert molding of the U-shaped core to the coil bobbin, a metal fitting (generally called a stay) for fixing the reactor body to the case is also insert-molded. The

  This stay is arranged with a slight gap above the U-shaped core at the time of insert molding. If the upper and lower surfaces of the U-shaped core are flat as described above, the stay and the upper surface of the core A member that supports the stay from below cannot be arranged between them. As a result, the stay can be held only from above, and the stay is deformed by the injection pressure at the time of resin molding, which causes a problem that the reactor cannot be accurately fixed to the case accommodating the reactor.

  The present invention has been made to solve the above-described problems. A first object is to provide a reactor having good magnetic characteristics without impairing the magnetic characteristics even if the core has a sliding surface formed by sliding with a mold, and a method for manufacturing the same. The second object is to provide a reactor capable of preventing the deformation of the fixing tool and installing the fixing tool with high accuracy when resin molding the core and the fixing tool as an insert product, and a method for manufacturing the same. .

The reactor of this invention has the following structures, It is characterized by the above-mentioned.
(1) An annular core comprising a plurality of leg portions and a pair of yoke portions connecting both ends of the leg portions.
(2) A coil mounted on at least a part of the annular core.
(3) The leg portion and the yoke portion are constituted by a powder magnetic core formed by press-molding soft magnetic powder.
(4) The yoke portion has a substantially flat surface formed by pressing and a sliding surface formed by sliding with a mold.
(5) The substantially flat surface includes a connection surface with the leg portion.
(6) The yoke portion is disposed so that the connection surface is orthogonal to the winding axis direction of the coil.

  In the present invention, the yoke portion may be provided with a notch portion on a surface orthogonal to the substantially flat surface.

  Moreover, the manufacturing method of the above reactors is also 1 aspect of this invention.

  According to the present invention, it is possible to suppress a loss and obtain a reactor having good magnetic characteristics. Moreover, when the notch part is provided in the yoke part, the deformation | transformation of a fixing tool can be prevented in the case of resin molding, and the reactor which can install a fixing tool with high precision can be obtained.

It is a perspective view which shows the whole structure of the reactor which concerns on 1st Embodiment. It is a disassembled perspective view which shows the whole structure of 1st Embodiment reactor. It is a disassembled perspective view which shows the core part in 1st Embodiment. It is the partial expanded side sectional view which looked at the coil bobbin in 1st Embodiment from the X direction. It is a figure which shows roughly the mode at the time of press-molding the yoke part of 1st Embodiment. (A) is sectional drawing seen from the Z direction, (b) is sectional drawing seen from the Y direction, (c) is a perspective view of the shape | molded yoke part 12. FIG. It is a photograph of the yoke part after removing from the fixed mold. (A) is a slide surface, (b) is a photograph of a press surface. It is a schematic diagram for demonstrating the resin mold molding process. (A) is a perspective view of a coil bobbin, (b) is the partial expanded side sectional view. It is a figure for demonstrating the conventional U-shaped core.

  Hereinafter, a reactor and a manufacturing method thereof according to an embodiment of the present invention will be described with reference to the drawings.

[First Embodiment]
[1-1. Constitution]
FIG. 1 is a perspective view showing the overall configuration of the reactor according to the present embodiment, and FIG. 2 is an exploded perspective view thereof. The reactor 1 is a large-capacity reactor used in, for example, a drive system for a hybrid vehicle or an electric vehicle. Reactor 1 is fixed in a heat radiating case (not shown) having a substantially rectangular parallelepiped housing space formed of a metal (for example, aluminum alloy) having high thermal conductivity and light weight. A gap is filled between the reactor 1 and the heat radiating case. As the filler, a relatively soft resin having a high thermal conductivity is suitable for ensuring the heat dissipation performance of the reactor 1 and reducing the vibration propagation from the reactor 1 to the heat dissipation case.

  As shown in FIGS. 1 and 2, the reactor 1 of this embodiment includes a core portion 10, a coil 20, a coil bobbin 30, and a fixture 40. In the following description, the Z-axis positive direction may be called “up”, the Z-axis negative direction may be called “down”, and the X and Y directions may be called “left-right direction”.

(1) Core unit 10
FIG. 3 is a diagram showing the core unit 10. As shown in FIGS. 2 and 3, the core portion 10 includes two leg portions 11 arranged in parallel, and a pair of yoke portions 12 that connect the two leg portions 11 at both ends thereof. That is, the core portion 10 forms an annular closed magnetic circuit by the end portions of the pair of leg portions 11 being abutted against the pair of yoke portions 12. The leg 11 includes a plurality of substantially rectangular parallelepiped divided cores 11a and plate-like spacers 11b. The leg portion 11 has an I-shape extending in one direction with a spacer 11b sandwiched between the plurality of split cores 11a. In the present embodiment, spacers 11b are respectively arranged between the four divided cores 11a and are fixed with an adhesive. The leg portion 11 extends in the Y-axis direction in FIGS. 2 and 3.

  The split core 11a is a magnetic powder molded body made of a dust core. That is, a powder magnetic core formed by coating an insulating coating around the magnetic powder is pressed by a mold in the direction of arrow P and molded. Of the surfaces of the split core 11a, a surface orthogonal to the Y-axis direction (a surface parallel to the X-axis direction) is a press surface formed by pressing. This press surface serves as a connection surface with the other divided core 11a or the yoke portion 12. As the magnetic powder, pure iron powder or amorphous soft magnetic powder (hereinafter simply referred to as “soft magnetic powder”) can be used.

  The insulating film can be formed from, for example, glass and a binder resin. As the glass, bismuth-based, phosphoric acid-based, alkali-based, and vanadium-based low melting glass can be used. Examples of the binder resin include silicone resins and waxes.

  The spacer 11b is a plate material made of, for example, a non-magnetic material (various ceramics such as alumina or resin). A magnetic gap having a predetermined width is provided between the split cores 11a to prevent a reduction in reactor inductance. In addition, an air gap may be sufficient and the spacer 11b may not be provided.

  The yoke portion 12 is a square block-shaped member, and is a core having a shape with a chamfered corner on the side opposite to the surface connecting the leg portions 11, and is configured by a dust core similar to the divided core 11a. . The yoke portion 12 is molded using a mold and has a press surface formed by pressing and a sliding surface formed by sliding with the inner surface of the mold when taken out from the mold. The yoke part 12 includes a connection surface 12a of the leg part 11 with the split core 11a and a groove-shaped notch part 12b. The connection surface 12a is one of the press surfaces and is substantially flat, and the ends of the pair of leg portions 11 are connected to the connection surface 12a. As shown in FIG. 3, the yoke portion 12 is arranged so that its flat connection surface 12 a is perpendicular to the magnetic path direction A. The connecting surface 12a is preferably flat.

  The notch 12b is formed on a sliding surface perpendicular to the connection surface 12a. In FIG. 3, the yoke portion 12 is formed on the upper surface and the lower surface, respectively. The notch 12b is a groove-like portion extending in a direction orthogonal to the connection surface 12a (the Y direction in FIG. 3), and both ends thereof are connected to and open to the connection surface 12a and the surface facing the connection surface 12a. The notch 12b is used for installing the fixing tool 40 with high accuracy when the core 10 and the fixing tool 40 are resin-molded together to form the coil bobbin 30. The shape of the notch 12b, the depth of the groove, and the number thereof are arbitrary, and can be appropriately changed according to the shape of the slider 62 used in the resin molding.

(2) Coil 20
The coil 20 is an enameled copper wire. The coil 20 is wound around the leg portion 11 of the core portion 10 via a coil bobbin 30. Specifically, the coil 20 has a configuration in which linear coil portions 21 and 22 having the same structure are arranged in parallel and one ends thereof are connected by a connecting wire 25. The coil 20 may be aluminum. Further, the case where the linear coil portions 21 and 22 are not connected by the connecting wire 25 is also included in the coil 20.

  The linear coil portions 21 and 22 are edgewise coils, for example, obtained by bending a rectangular wire in a right angle direction at four locations per turn and winding it in a substantially square shape. As shown in FIG. 2, the air core portions of the linear coil portions 21 and 22 have R shapes at the four corners that appear when cut in a direction orthogonal to the winding axis direction (hereinafter referred to as air core portion shape). It has a substantially rectangular shape. Terminals 23 and 24 which are one ends of linear coil portions 21 and 22 are connected to a load.

  The above-described leg portion 11 is inserted and disposed in the air core portion of the linear coil portions 21 and 22, and the yoke portion 12 is disposed outside the linear coil portions 21 and 22. The winding direction (X-axis direction) of the linear coil portions 21 and 22 and the press surfaces of the split core 11a and the yoke portion 12 are parallel. In other words, the winding axis direction (magnetic path direction) of the linear coil portions 21 and 22 and the press surfaces of the split core 11a and the yoke portion 12 are orthogonal to each other.

(3) Coil bobbin 30
As shown in FIG. 2, the coil bobbin 30 has a cylindrical shape following the core portion 10 and has a substantially rectangular cross section so as to place the core portion 10 inside. The coil bobbin 30 insulates the core portion 10 and the coil 20 from each other. Examples of the main material include unsaturated polyester resins, urethane resins, epoxy resins, BMC (Bulk Molding Compound), PPS (Polyphenylene Sulphide), PBT (Polybutylene Terephthalate), and the like.

  The coil bobbin 30 is divided into two parts in a direction orthogonal to the axial direction of the legs 11. That is, the first yoke side bobbin 31 having a substantially U shape having a pair of cylindrical portions 31a and the second yoke side bobbin 32 having a substantially T shape are configured. The first and second yoke bobbins 31 and 32 include insert portions 31b and 32b, respectively. The yoke portion 12 and the fixture 40 are embedded in the insert portions 31b and 32b by a technique such as injection molding. In the cylindrical portion 31a of the first yoke-side bobbin 31, the split core 11a constituting the leg portion 11 is inserted when the reactor is assembled, and the coil 20 is fitted around the cylindrical portion 31a.

  A plurality of holes 33 are formed in the upper surfaces of the first yoke side bobbin 31 and the second yoke side bobbin 32. A hole 34 is formed in the first yoke side bobbin 32. As will be described later, these holes 33 and 34 are formed by a mold that presses the fixture 40 from above and below in the resin molding process. The hole 34 communicates with the notch portion 12 b of the yoke portion 12.

(4) Fixing tool 40
The fixture 40 is a metal plate, is set as an insert in the mold of the coil bobbin 30, and is configured integrally with the coil bobbin 30 by filling the mold with resin. That is, as shown in FIGS. 1 and 2, the fixture 40 has a central portion embedded in the resin forming the coil bobbin 30, and both ends projecting outward from the four corners of the coil bobbin 30. Bolt holes 41 are formed at both ends of the fixture 40. The reactor 1 is fastened and fixed to the heat radiating case with bolts through the bolt holes 41.

  As shown in FIG. 4, the fixture 40 is fixed 2 mm above the upper surface of the yoke portion 12. That is, when the coil bobbin 30 is formed, the fixture 40 is an insert product together with the yoke portion 12, and is injection-molded with the fixture 40 fixed above the upper surface of the yoke portion 12, and its position is fixed. Yes. Here, as an example, it is assumed that it is fixed 2 mm above the upper surface of the yoke portion 12, but how much it is positioned above the upper surface of the yoke portion 12 depends on the depth of the notch portion 12 b and the slider 62 described later. It is determined by the shape and the like, and is not particularly limited to 2 mm.

Next, the manufacturing process of the reactor having the above configuration will be described. The manufacturing process of the reactor of the present embodiment includes the following steps (a) to (d).
(A) Split core forming step (b) Yoke part forming step (c) Resin mold forming step (d) Closed magnetic path forming step

Hereinafter, each step will be described in detail.
(A) (b) Split core forming step and yoke portion forming step The split core forming step and the yoke portion forming step will be described. The split core 11a and the yoke portion 12 constituting the core portion 10 are formed by press molding. Both differ only in shape, and both have the same pressing direction. Since the formation process of the split core 11a and the yoke part 12 is the same, the press molding of the yoke part 12 will be described below as a representative.

  FIG. 5 is a view schematically showing press forming of the yoke portion 12 by the press forming die. 5A is a cross-sectional view of the press mold as viewed from the Z direction (upward), FIG. 5B is a cross-sectional view of the press mold as viewed from the Y direction, and FIG. 5C is formed. FIG. As shown in FIG. 5A, the press mold 50 includes a cylindrical fixed mold 51 that surrounds a unidirectional axis (Y axis), and a pair of movable molds 52 that block openings at both ends of the fixed mold 51. ing. A cavity defined by the fixed mold 51 and the pair of movable molds 52 is filled with an insulating-coated soft magnetic powder, which is a molding material. After the soft magnetic powder is filled, when the pair of movable dies 52 are relatively moved in a direction approaching each other (arrow P direction), the powder magnetic core in the cavity is compressed and the yoke portion 12 is formed. The fixed mold 51 and the movable mold 52 are fitted with a gap, for example.

  As shown in FIG. 5B, the fixed mold 51 has a convex portion 51a protruding inward (Z direction), and the shape of the convex portion 51a determines the shape of the notch portion 12b. In other words, the cutout portion 12 is formed by the shape of the convex portion 51a, and is not formed by pressing in the Z direction. By changing the shape and the number of the convex portions 51a as appropriate, the desired shape and the number of the notch portions 12b can be formed. In FIG.5 (c), the convex part 51a has the convex shape extended in the Y direction.

  As shown in FIG. 5C, a sliding surface S1 and a press surface Sp are formed on the molded yoke portion 12. That is, when the yoke portion 12 is molded by press molding, the yoke portion 12 that has become a molded body needs to be removed from the fixed mold 51. At that time, the sliding surface S1 in contact with the fixed mold 51 of the yoke portion 12 rubs against the fixed mold 51, so that the insulating coating around the magnetic powder on the sliding surface S1 is damaged. On the other hand, the press surface Sp is a surface formed by being pressed by the movable mold 52, and is a substantially flat surface. This press surface Sp does not face the fixed mold 51. That is, since the pressing direction and the demolding direction of the yoke portion 12 are the same, the press surface Sp is not rubbed when demolding from the fixed mold 51. Therefore, the insulating coating around the magnetic powder on the press surface Sp is not damaged. In the split core 11a, the surface in contact with the fixed die is the sliding surface S1, and the surface in contact with the movable die is the press surface Sp. Further, it is desirable that the press surfaces Sp of the split core 11a and the yoke portion 12 are flat.

FIG. 6 is a photograph of the yoke part 12 after being removed from the fixed mold 51. The photograph in FIG. 6 shows a range of 400 μm × 576 μm. The yoke part 12 is a mixture of pure iron powder having an average particle diameter of 40 μm having a SiO film around it and adding silicone resin (1.8 wt%), and filling the resulting mixture into the press mold 50. and, those which are molded by pressing at normal temperature of the mold at a pressure of ^{7ton / cm 2 ~9ton / cm 2} . FIG. 6A is a photograph of the sliding surface S1, and FIG. 6B is a photograph of the press surface Sp. In FIG. 6, roughly divided, there are a portion that looks white and a portion that looks black. The portion that appears white indicates pure iron powder (for example, symbol B), and the portion that appears black indicates an insulating coating or space. Of the portion that looks black, the relatively narrow portion of the boundary between the pure iron powders B is the insulating coating (for example, symbol C), and the relatively large portion is the space (for example, symbol D). In the sliding surface S1, it turns out that the insulating film C is damaged by sliding with the fixed mold | type 51. FIG. That is, it can be seen that pure iron powders are in direct contact with each other on the sliding surface S1, and a thin layer is formed. Therefore, a loss occurs on the sliding surface S1, and the magnetic characteristics deteriorate. For example, as indicated by reference numeral E, there are scratches on the top and bottom of the photograph, and it can be seen that the yoke portion 12 has been taken out in this direction. On the other hand, since the press surface Sp does not slide with the fixed mold 51, the insulating coating C remains as it is, and the magnetic characteristics remain good.

(C) Resin mold molding process The resin mold molding process using the notch part 12b is demonstrated, referring FIG. FIGS. 7A and 7B are schematic views for explaining a process of performing resin injection molding by setting the yoke portion 12 and the fixture 40 as inserts in a mold. The mold includes an upper mold and a lower mold. A slider 62 is integrally formed with the lower mold, and a protrusion 64 is integrally formed with the upper mold. In FIGS. 7A and 7B, since the drawings are complicated, the illustration of these molds is omitted, and only the slider 62 and the protrusion 64 necessary for explanation are explicitly shown.

  The coil bobbin 30 is formed by filling a resin between an upper mold and a lower mold and solidifying the resin. The fixture 40 is fixedly installed in this process. The first and second yoke-side bobbins 31 and 32 are the same as the process itself except for the shapes, and the following description applies to both. The resin mold molding process is as follows (c1) to (c4).

(C1) The yoke portion 12 is set in the lower die, and is set so that the lower die slider 62 is positioned in the notch portion 12b on the upper surface of the yoke portion 12.
(C2) The fixture 40 is set on the flat surface 62a of the slider 62. That is, as shown in FIGS. 7A and 7B, the slider 62 has a stepped shape, and is set so that the flat surface 62 a lowered by one step is in contact with the back surface of the fixture 40.
(C3) The upper mold is set so that the two protrusions 64 of the upper mold are positioned on the upper surface of the fixture 40.
(C4) Resin is filled and solidified in a state where the fixture 40 is firmly sandwiched in the vertical direction at two locations by the protrusions 64 from above and at one location by the slider 62 from below.
The holes 33 and 34 of the coil bobbin 30 are holes formed without being filled with resin because the fixture 40 is pressed by the protrusion 64 and the slider 62. That is, the shapes of the holes 33 and the protrusions 64 are the same, and the shapes of the holes 34 and the slider 62 are the same. In the above description, the slider 62 and the protrusion 64 are integrated with the upper mold and the lower mold, but may be separate from the upper mold and the lower mold.

  The first yoke side bobbin 31 and the second yoke side bobbin 32 are formed through the steps (c1) to (c4). After the first yoke-side bobbin 31 and the second yoke-side bobbin 32 are formed, the leg portion 11 composed of the split core 11a and the spacer 11b is accommodated inside the cylindrical portion 31a of the first yoke-side bobbin 31. At the same time, the coil 20 is fitted around the cylindrical portion 31a. Thereafter, the end portions of the first yoke-side bobbin 31 and the second yoke-side bobbin 32 are abutted to constitute the coil bobbin 30.

(D) Closed magnetic circuit formation process Next, a closed magnetic circuit formation process is demonstrated. This step is a step of forming an annular closed magnetic path by abutting a pair of yoke portions 12 at both ends of two I-shaped leg portions 11 arranged in parallel.

  The split core 11a and the yoke portion 12 of the present embodiment are manufactured as in the above steps (a) and (b) only in the shape of the press mold 50, and the pressing direction is the same. The split core 11a and the yoke portion 12 are arranged so that the press surfaces Sp are parallel to each other, and the press surfaces Sp are connected to each other. In other words, the split core 11a and the yoke portion 12 are arranged and connected so that the press surface Sp to be connected is perpendicular to the magnetic path direction A. The press surface Sp of the split core 11a is a connection surface that is connected to another split core 11a or the yoke portion 12. Of the press surface Sp of the yoke portion 12, the press surface Sp facing the split core 11a is the connection surface 12a. A closed magnetic circuit is configured by the end portions of the two I-shaped leg portions 11 being abutted against the connection surfaces 12 a of the pair of yoke portions 12.

[1-2. Effect]
(1) In the reactor 1 of the present embodiment, the connection surface connected to each other between the press surface Sp of the leg portion 11 and the press surface Sp of the yoke portion 12 is orthogonal to the winding axis direction (magnetic path direction) of the coil 20. In addition, the closed magnetic circuit was configured by abutting the connecting surface of the leg portion 11 arranged in parallel with one connecting surface 12a of the yoke portion 12. Thereby, the flat connection surface formed by pressing the leg portion 11 and the yoke portion 12 is perpendicular to the coil winding axis direction (magnetic path direction), and the sliding surface S1 does not intersect the magnetic path direction. An increase can be suppressed and a reactor having good magnetic properties can be obtained.

(2) Further, since the sliding surface S1 does not cross the closed magnetic path, it is not necessary to perform cutting or etching on the sliding surface S1. Furthermore, the addition of the lubricating resin to the inner surface of the press mold 50 can be omitted. Therefore, it is possible to provide a high-mass productivity reactor with low cost and a small number of processes.

(3) A groove-shaped notch 12 b is provided on a surface orthogonal to the press surface Sp that is abutted against the leg portion 11 of the yoke portion 12. As a result, when forming the coil bobbin 30, the yoke portion 12 and the fixture 40 can be set as inserts in the mold, and the fixture 40 can be sandwiched by the slider 62 and the protrusion 64 from the front and back surfaces. The tool 40 can be fixed and installed with high accuracy. As a result, the accuracy of fixing the position of the reactor 1 to the heat radiating case is improved. Further, conventionally, due to the space, the fixture 40 can only be pressed from above, and the fixture 40 has been deformed downward in the process of resin molding, but by forming the notch 12b, Since the fixing device 40 can be pressed from below, the deformation of the fixing device 40 can be prevented.

(4) According to the reactor manufacturing method of the present embodiment, the notched portions 12b can be formed on the upper surface and the lower surface of the yoke portion 12 because the pressing directions of the split core 11a and the yoke portion 12 are the same. . That is, it was theoretically possible to form the notch portion in the past, but the conventional yoke portion was a U-shaped core, and the pressing direction was a vertical direction perpendicular to the pressing direction of the split core 11. . Therefore, in order to provide notches on the upper and lower surfaces of the U-shaped core, it is common to press with a complicated and costly multi-stage mold with protrusions in order to make a step. The pressure applied to the molding material differs depending on whether the part is attached or not. For this reason, the density of the U-shaped core is non-uniform and there is a problem that it is difficult to establish a usable product. On the other hand, in the present invention, the pair of leg portions of the U-shaped core is eliminated, and the pressing directions of the split core 11a and the yoke portion 12 are made the same. Thereby, the notch 12b can be formed not by a press but by the shape of the fixed die 51, and the density of the yoke 12 does not become non-uniform as in the prior art.

[Other Embodiments]
(1) Although the leg part 11 of 1st Embodiment was supposed to have the some division | segmentation core 11a, the division | segmentation core 11a of the leg part 11 may be one.
(2) The yoke portion 12 shown in FIG. 3 of the first embodiment has a substantially hexagonal cross section, but is not limited thereto, and the cross section may be a polygonal shape such as a semicircular shape or a quadrangular shape. .
(3) The corners of the split core 11a and the yoke portion 12 may be rounded and rounded.

(4) The groove-shaped notch portion 12b of the yoke portion 12 has a groove that leads to the connection surface 12a and the press surface facing the surface, and both ends of the groove may be open, or only one end of the groove You may open to the press surface which faces the connection surface 12a. It suffices that the slider 62 slides to the lower side of the fixture 40.
(5) The notch part 12b should just be provided in the surface of the yoke part 12 which faces the fixing tool 40, and can also be made only into either an upper surface or a lower surface.
(6) The position and shape of the fixture 40 may be different from those illustrated, or different fixtures 40 may be used for the first yoke side bobbin 31 and the second yoke side bobbin 32.

(7) The leg portion 11 and the yoke portion 12 may be bonded by an adhesive, or may be connected by being crimped and held by the first and second yoke-side bobbins 31 and 32 instead of being bonded.
(8) In the first embodiment, no spacer is disposed between the leg portion 11 and the yoke portion 12, but they may be connected via a spacer.

(9) In the first embodiment, the core portion 10 has a substantially rectangular annular shape by abutting two leg portions 11 arranged in parallel with each other and a pair of yoke portions 12 from both end sides thereof. However, it is not limited to this. Three or more leg portions 11 may be arranged in parallel and the core portion 10 may be configured by abutting a pair of yoke portions 12 from both ends thereof.

  For example, when there are three leg portions 11, one end of each leg portion 11 is connected to the connection surface 12a of one yoke portion 12, and the other end of each leg portion 11 is connected to the connection surface 12a of the other yoke portion 12. The core unit 10 is configured. In this case, for example, two closed magnetic paths are formed by attaching a coil to the central leg 11. That is, one is a closed magnetic path in which the magnetic flux is directed in the direction of the central leg 11 → the one yoke part 12 → the one outer leg part 11 → the other yoke part 12 → the central leg part 11. The other is a closed magnetic path in which the magnetic flux is directed in the direction of the center leg 11 → the one yoke part 12 → the other outer leg part 11 → the other yoke part 12 → the center leg part 11. Alternatively, a coil may be attached to each of the two outer legs 11 to form two closed magnetic paths. Further, a configuration may be adopted in which a coil is attached to each leg portion 11 to form two closed magnetic paths. In addition, the location where the coil is mounted on the leg portion 11 can be appropriately changed on the user side according to the specification. Further, the coil may be mounted on the yoke portion 12, and the mounting position can be changed as appropriate according to the specification.

DESCRIPTION OF SYMBOLS 10 Core part 11 Leg part 11a Split core 11b Spacer 12 Yoke part 12a Connection surface 12b Notch part 20 Coil 21 Linear coil part 22 Linear coil part 23 Terminal 24 Terminal 25 Connecting wire 30 Coil bobbin 31 1st yoke side bobbin 31a Cylindrical part 31b Insert portion 32 Second yoke side bobbin 32b Insert portion 33 Hole 34 Hole 40 Fixture 41 Bolt hole 50 Press molding die 51 Fixed die 51a Convex portion 52 Movable die 62 Slider 62a Plane 64 Protrusion A Magnetic path direction B Pure iron powder C Insulating coating D Space E Scratch S1 Sliding surface Sp Press surface

Claims (5)

An annular core comprising a plurality of leg portions and a pair of yoke portions connecting both ends of the leg portions;
A coil mounted on at least a part of the annular core,
The leg portion and the yoke portion are constituted by a powder magnetic core formed by press-molding soft magnetic powder,
The yoke portion has a substantially flat surface formed by pressing, and a sliding surface formed by sliding with a mold,
The substantially flat surface includes a connection surface with the leg,
The said yoke part is arrange | positioned so that the said connection surface may orthogonally cross the winding axis direction of the said coil, The reactor characterized by the above-mentioned.   The reactor according to claim 1, wherein the yoke portion is provided with a notch on a surface orthogonal to the substantially flat surface. A split core molding step of pressing a molding material filled in a mold from a predetermined direction and forming a split core having a substantially flat surface formed by the press;
A yoke part that presses a molding material filled in a mold from a predetermined direction and has a substantially flat surface formed by the pressing, and forms a yoke part disposed outside the coil air core part of the coil. Molding process;
A split core placement step of placing the split core in a coil air core portion of the coil with a substantially flat surface connected to the yoke portion oriented in a direction perpendicular to the coil winding axis direction;
The yoke portion is oriented so that a substantially flat surface connected to the divided core is a surface orthogonal to the winding axis direction of the coil, and the substantially flat surfaces of the plurality of divided cores are on the substantially flat surface. A closed magnetic circuit forming step of connecting each to form a closed magnetic circuit,
The method of manufacturing a reactor, wherein the split core forming step and the yoke portion forming step have the same pressing direction when forming the split core and the yoke portion.   The said yoke part formation process forms a notch part in the surface orthogonal to the substantially flat surface connected with the said division | segmentation core, The manufacturing method of the reactor of Claim 3 characterized by the above-mentioned. Further comprising a resin molding step of resin molding the yoke part and the fixture as an insert product,
The resin mold molding process includes:
5. The resin molding is performed according to claim 4, wherein the fixing tool positioned above the cutout portion of the yoke portion is resin-molded in a state of being sandwiched from both the front surface and the back surface of the fixing device. Reactor manufacturing method.