JP2012015382A - Reactor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To omit a case and to provide a reactor exhibiting excellent air cooling performance.SOLUTION: The reactor comprises: a coil 2 formed by winding a wire; a magnetic core 3 disposed at least inside of the coil 2; and a resin coating 5 which covers the outer periphery of an assembly 10 of the coil 2 and magnetic core 3. The resin coating 5 has a plurality of ventilation grooves 6 extending from one end side toward the other end side along the surface thereof, and all ventilation grooves 6 are formed in parallel with each other. Since contact area of the resin coating 5 and wind can be increased, and heat transfer rate of air can be prevented from lowering by preventing the wind velocity from lowering, heat generated from the assembly 10 can be discharged efficiently through the resin coating 5, and excellent air cooling performance is ensured.

Description

  The present invention relates to a reactor used for a component part of a power conversion device such as a vehicle-mounted DC-DC converter mounted on a vehicle such as a hybrid vehicle. In particular, it relates to a reactor with excellent heat dissipation performance.

  A reactor is one of the parts of a circuit that performs a voltage step-up operation or a voltage step-down operation. For example, as disclosed in Patent Document 1, the reactor is configured such that a coil formed by winding a winding and a core disposed inside the coil are housed in a high heat conduction case. . A reactor mounted on a hybrid vehicle or the like has a large current / high voltage specification, and therefore generates a large amount of heat in the coil and the core. Therefore, in Patent Document 1, the case where the coil and the core are housed is filled with the potting resin, and the heat generated from the coil and the core and transferred to the case through the potting resin is connected to the heat sink (cooling base). It is comprised so that it may discharge | release from.

Japanese Patent Laid-Open No. 2005-072198

  In general, a water-cooling type cooling structure in which cooling water is introduced into a cooling base is often used as a heat dissipation structure. However, depending on the usage environment of the device on which the reactor is mounted and the installation location, cooling may be performed by forced air cooling. Therefore, a reactor configuration that can dissipate heat more efficiently by cooling by air cooling is desired.

  Further, it is preferable to reduce the amount of materials used in order to realize cost reduction of the reactor.

  The present invention has been made in view of the above circumstances, and one of its purposes is to provide a reactor that omits the case and is excellent in air cooling performance.

  Moreover, the other objective of this invention is to provide the installation structure of the reactor which can utilize the said reactor of this invention efficiently.

  Furthermore, another object of the present invention is to provide a reactor manufacturing method capable of efficiently manufacturing the reactor of the present invention.

  When the reactor is cooled by forced air cooling such as a fan, the thermal resistance R between the reactor surface and air is expressed as 1 / (h × s) (h: heat transfer coefficient of air, s: heat dissipation area of the reactor). The heat transfer coefficient h of air is a function of its speed (wind speed) v. This invention achieves the said objective by making it a reactor which enlarges the thermal radiation area of the said reactor and prevents the fall of the heat transfer rate of air, and makes a thermal resistance small, and a case can be abbreviate | omitted.

  The present invention relates to a reactor comprising a coil formed by winding a winding, a magnetic core disposed at least on the inside of the coil, and a resin coating that covers an outer periphery of a combined body of the coil and the magnetic core. It is. The resin coating portion includes a plurality of ventilation grooves extending from one end side toward the other end side along the surface thereof, and all of these ventilation grooves are formed in parallel.

  According to the said structure, the surface area of a resin coating part can be increased by forming a ventilation groove in the surface of a resin coating part. Therefore, since the contact area with the wind can be increased, the heat generated in the combined body can be efficiently released through the resin coating portion, and the reactor of the present invention has excellent air cooling performance. In particular, since the reactor of the present invention is cooled by air cooling, it can be uniformly and efficiently air-cooled over most of the surface of the assembly. And when all the formed several ventilation grooves are parallel, when making the direction where the ventilation grooves extend, and a wind direction into the same direction, the fall of a wind speed can be prevented. Therefore, it is possible to prevent a decrease in the heat transfer coefficient of air. The wind from the air blowing means such as a fan is preferably cold air.

  Furthermore, when it is a straight line on the installation surface of the reactor of the present invention and the installation reference line serving as a reference for the installation direction of the reactor is defined, the ventilation groove is formed by a group of straight lines connecting any two points along the ventilation groove. The form currently formed so that the plane made and the said installation reference line may become parallel is mentioned.

  The reactor installation reference line is a straight line for determining the installation direction of the reactor along the wind direction when the reactor is installed on a blowing means such as a fan. The ventilation groove is in the above-mentioned form means that the ventilation groove is substantially along the installation reference line of the reactor and does not cross the installation reference line or meander the ventilation groove. That is, the ventilation groove is almost along the wind direction. According to the said structure, the increase with respect to the wind of the reactor which has a ventilation groove | channel can be prevented, and the fall of a wind speed can be prevented more effectively. Therefore, a local decrease in wind speed can be prevented, and a decrease in air heat transfer coefficient can be prevented.

  The direction in which the ventilation groove extends with respect to the combination can be a desired direction. That is, it is only necessary to provide a ventilation groove so that air can be cooled more effectively with respect to the constituent members of the combined body that are more effectively air-cooled. For example, if it is desired to air-cool the coil more effectively, it is only necessary to provide a ventilation groove along the axial direction of the coil. If it is desired to air-cool the magnetic core more effectively, the coil is aligned along the direction orthogonal to the axial direction of the coil. It is sufficient to provide a ventilation groove. For example, when the reactor is a rectangular parallelepiped, the surface of the reactor is perpendicular to the wind direction (front and rear as viewed from the fan or other blowing means), and the surface along the wind direction (side and top, but the reactor installation surface) (Except for the lower surface), the rear surface is less likely to be directly hit by the wind, and the air cooling performance is lower than the front and side surfaces. Therefore, it is preferable to provide the ventilation groove so that the constituent members of the combined body to be air-cooled more effectively are located on the surface side along the wind direction.

  As one form of this invention reactor, the form whose ventilation groove | channel is a linear groove | channel is mentioned.

  When the ventilation groove is a straight groove, when the wind flows along the longitudinal direction of the ventilation groove, an increase in resistance to the wind of the reactor having the ventilation groove can be prevented, and a decrease in the wind speed can be more effectively prevented. Can do. Therefore, a local decrease in wind speed can be prevented, and a decrease in air heat transfer coefficient can be prevented.

  As one form of this invention reactor, the form whose ventilation groove | channel is a curved groove | channel is mentioned.

  In the case where the resin coating portion has a streamline shape, for example, at least one end side of the resin coating portion may be a cone shape having a tapered surface or a substantially spindle shape. In that case, since the ventilation groove is a curved groove along the shape, an increase in resistance to the wind of the reactor having the ventilation groove can be prevented, and a decrease in wind speed can be more effectively prevented. Therefore, a local decrease in wind speed can be prevented, and a decrease in air heat transfer coefficient can be prevented.

  As one form of this invention reactor, the form whose at least one end side in a resin coating part is the taper-like shape which protruded rather than the surface of the said one end side of an assembly is mentioned.

  The streamline shape of the resin coating portion is particularly preferably formed on at least one end side of the ventilation groove. This one end side is the side facing the wind direction. The flow of wind can be improved by making the shape of the resin coating portion on the side facing the wind direction into a tapered shape protruding from the surface on the one end side of the combined body. According to the said structure, the resistance with respect to the wind of the reactor which has a ventilation groove can be reduced, and a wind speed can be raised compared with the case where the ventilation groove does not follow the installation reference line of a reactor. What is more effective is that the front surface of the combined body has the streamline shape as viewed from the air blowing means such as a fan. By doing so, compared with the case where the resin coating part is a plane, the heat transfer rate of air can be improved by the increase in a wind speed. If it is this form, both the thermal radiation area of a reactor and the heat transfer coefficient of air can be enlarged, and the air cooling performance of a reactor can further be improved.

  The reactor installation structure of the present invention is characterized in that, in a state where the reactor is installed on a fixed object, the reactor is fixed so that the ventilation groove follows the wind direction.

  When the ventilation groove is along the wind direction, it is possible to prevent a decrease in wind speed, a decrease in heat transfer coefficient of air, and an excellent air cooling performance. Further, when at least one end side of the resin coating portion is tapered so as to protrude from the surface of the one end side of the combined body, the protruded protruding portion is blown by a fan or the like on a surface orthogonal to the wind direction on the surface of the combined body. By providing it on the front as viewed from the means, the wind speed in the vicinity of the ventilation groove can be increased. Therefore, the heat transfer rate of air can be improved as compared with the case where the resin coating portion having the ventilation grooves is flat.

The manufacturing method of the reactor of this invention is equipped with the following process, It is characterized by the above-mentioned.
(1) Preparation step of preparing a combination of a coil formed by winding a winding and a magnetic core disposed at least inside the coil
(2) Arrangement step of preparing a mold comprising an outer container and an inner mold disposed in the outer container, and disposing the assembly in the inner mold
(3) Molding process to obtain a molded product integrating the assembly and resin by injecting resin into the inner mold and curing
(4) Extraction step of taking out the molded product from the inner mold In the arrangement step, the outer container has an opening and a plurality of extrusion holes in the bottom plate facing the opening, and the inner mold is filled with the resin. A plurality of divided pieces forming a space are provided, and at least one of the divided pieces has a protrusion for forming a ventilation groove along the surface of the molded product, and a plurality of protrusions are formed by combining these divided pieces. Are all formed in parallel.
In the extraction step, the inner mold is extruded from the outer container by applying a force to the inner mold through the extrusion hole, and each divided piece constituting the inner mold is removed from the molded product.

  Since this invention reactor is the uneven | corrugated shape by the ventilation groove | channel on an outer surface, this invention reactor can be efficiently manufactured by forming the inner side shaping | molding die which is a shaping | molding die of a resin coating part with a split piece.

  The reactor of the present invention can increase the surface area of the resin coating portion and can increase the contact area with the wind, so that the heat generated in the assembly can be efficiently released through the resin coating portion, Excellent air cooling performance. Further, since all the formed ventilation grooves are arranged in parallel, an increase in resistance to wind can be prevented, and a decrease in wind speed can be prevented. Therefore, it is possible to prevent a decrease in the heat transfer coefficient of air.

  In the reactor installation structure of the present invention, since the ventilation groove of the reactor of the present invention is along the wind direction, it is possible to prevent a decrease in wind speed, to prevent a decrease in air heat transfer coefficient, and to improve air cooling performance. Excellent.

  The reactor of the present invention can be efficiently manufactured by the method for manufacturing a reactor of the present invention.

1 is a schematic perspective view showing a reactor of Embodiment 1. FIG. FIG. 2 is an exploded perspective view showing an outline of a combination of a coil and a magnetic core provided in the reactor of the first embodiment. 1 shows a method for manufacturing a reactor according to the present invention according to Embodiment 1, (A) is a schematic perspective view of a split piece of an inner mold, (B) is a schematic perspective view of each configuration in an installation process, and (C) is a molding process. It is a schematic perspective view of each structure in FIG. The reactor of Embodiment 2 is shown, (A-a) and (A-b) are plan views, and (B-a) to (B-d) are side views. FIG. 6 shows a structure for forming a ventilation groove as an example of the reactor of Embodiment 2, wherein (A) is a cross-sectional view thereof, and (B) is a perspective view of a cross-section taken along the line AA in FIG. 5 (A).

  Hereinafter, a reactor according to an embodiment will be described with reference to the drawings. The same reference numerals in the figure indicate the same names.

<Embodiment 1>
A reactor 1 according to the present invention will be described with reference to FIGS. As shown in FIG. 1, the reactor 1 includes a coil 2 formed by winding a winding, a magnetic core 3 disposed at least inside the coil 2, and a combination 10 of the coil 2 and the magnetic core 3. And a resin coating portion 5 that covers the outer periphery. The resin coating portion 5 includes a plurality of ventilation grooves 6 extending from one end side toward the other end side along the surface thereof, and the ventilation grooves 6 are all formed in parallel. Hereinafter, each configuration of the reactor 1 will be described in more detail.

[Union]
A combination 10 composed of the coil 2 and the magnetic core 3 will be described with reference to FIG.

(coil)
The coil 2 has a pair of coil elements 2a and 2b formed by winding the winding 2w in a spiral shape. The two coil elements 2a and 2b are arranged side by side in parallel with the same number of turns so that the respective axial directions are parallel to each other. The winding 2w is preferably a coated wire having an insulating coating made of an insulating material on the outer periphery of a conductor made of a conductive material such as copper or aluminum. Here, the coil 2 is formed by edgewise winding a rectangular wire with a conductor made of a rectangular copper wire and an insulating coating made of enamel. As the winding 2w, in addition to a conductor made of a flat wire, various shapes such as a circular shape, an elliptical shape, and a polygonal shape can be used.

  Each of the coil elements 2a and 2b has a rectangular shape with rounded corners when viewed from the axial direction. As the end face shape, a rectangular shape, a circular shape or a polygonal shape other than a rectangular shape can be used. In addition, the coil elements 2a and 2b are joined to each other at one end of the windings by welding or the like via a connecting piece (see FIG. 1). This connecting piece is also formed of a covered rectangular wire similar to the winding 2w. Examples of the welding include TIG welding, laser welding, resistance welding, and the like. In addition, one end of the winding may be joined by crimping, cold welding, vibration welding, or the like. The coil 2 can also constitute the coil elements 2a and 2b with one continuous winding. In this case, the coil elements 2a and 2b are connected to each other by folding back a part of the winding. Here, the pair of coil elements 2a and 2b is configured to be provided in parallel, but the coil may be configured to include one coil element.

  Both ends of the winding 2w forming each coil element 2a, 2b are appropriately extended from the turn portion and drawn out to the outside of the resin coating portion 5 described later. A terminal member (not shown) made of a conductive material such as copper or aluminum is connected to the conductor portion exposed by peeling off the insulating coating. An external device (not shown) such as a power source for supplying power is connected to the coil via the terminal member. In addition to welding such as TIG welding, crimping or the like can be used to connect the conductor portion of the winding 2w and the terminal member.

(Magnetic core)
The magnetic core 3 has a pair of inner core portions 31 disposed inside the coil elements 2a and 2b, and a pair of outer core portions 32 exposed from the coil 2, respectively. Here, each inner core portion 31 and each outer core portion 32 have a rectangular parallelepiped shape. The magnetic core 3 has an outer core portion 32 disposed so as to sandwich the inner core portion 31 that is spaced apart, and is formed in an annular shape by contacting the end surface of each inner core portion 31 and the inner end surface of the outer core portion 32 Is done. The inner core portion 31 and the outer core portion 32 form a closed magnetic path when the coil 2 is excited.

  The inner core portion 31 and the outer core portion 32 are entirely composed of a green compact, and no gap material, air gap, or adhesive is present.

  The green compact is typically obtained by molding a soft magnetic powder having an insulating coating on the surface and firing it at a temperature lower than the heat resistance temperature of the insulating coating. A mixed powder in which a binder is appropriately mixed in addition to the soft magnetic powder can be used, or a powder having a coating made of a silicone resin or the like can be used as the insulating coating. The saturation magnetic flux density of the green compact can be changed by adjusting the material of the soft magnetic powder, the mixing ratio of the soft magnetic powder and the binder, the amount of various coatings, and the like. For example, a powder compact with a high saturation magnetic flux density can be obtained by using a soft magnetic powder with a high saturation magnetic flux density or by increasing the proportion of the soft magnetic material by reducing the blending amount of the binder. In addition, the saturation magnetic flux density tends to be increased by increasing the molding pressure. It is preferable to select a soft magnetic powder and adjust a molding pressure so as to obtain a desired saturation magnetic flux density.

  The above soft magnetic powder includes Fe-based alloy powders such as Fe-Si, Fe-Ni, Fe-Al, Fe-Co, Fe-Cr, Fe-Si-Al as well as iron group metal powders such as Fe, Co and Ni. Or rare earth metal powder, ferrite powder, etc. can be used. In particular, the Fe-based alloy powder is easy to obtain a green compact with a high saturation magnetic flux density. Such a powder can be produced by an atomizing method (gas or water), a mechanical pulverization method, or the like. In particular, when a powder made of a nanocrystalline material whose crystals are nano-sized, preferably a powder made of an anisotropic nanocrystalline material, a compact with a high anisotropy and a low coercive force is obtained. Examples of the insulating coating formed on the soft magnetic powder include a phosphoric acid compound, a silicon compound, a zirconium compound, or a boron compound. Examples of the binder include thermoplastic resins, non-thermoplastic resins, and higher fatty acids. This binder disappears by the above baking, or changes to an insulator such as silica. The compacted body is a case in which an insulating material such as an insulating film is present so that soft magnetic powders are insulated from each other, eddy current loss can be reduced, and high-frequency power is applied to the coil. However, the loss can be reduced. A well-known thing may be utilized for a compacting body.

(Other components)
The combined body 10 is provided with a bobbin 4 between the coil 2 and the magnetic core 3 to enhance insulation. The bobbin 4 includes a configuration including a cylindrical bobbin 41 disposed on the outer periphery of the inner core portion 31 and a pair of frame-shaped bobbins 42 that are in contact with the end face of the coil 2. Here, the cylindrical bobbin 41 has an opening that passes through each surface, and the entire circumference of the inner core portion 31 is not covered by the cylindrical bobbin 41. The frame-shaped bobbin 42 has a rectangular plate shape. In this configuration, there are two openings, and the end portions of the inner core portions 31 are not entirely covered. As the constituent material of the bobbin 4, an insulating resin such as a polyphenylene sulfide (PPS) resin, a liquid crystal polymer (LCP), or a polytetrafluoroethylene (PTFE) resin can be suitably used. Furthermore, between the inner core portion 31 and each frame-shaped bobbin 42, a material having a lower magnetic permeability than the inner core portion 31, such as alumina, glass epoxy resin, unsaturated polyester, etc., typically a nonmagnetic material is used. The gap material 43 may be provided.

[Resin coating]
As shown in FIG. 1, the resin coating portion 5 covers the outer periphery of the assembly 10 with the resin coating portion 5. The resin coating 5 has various effects such as protection from the external environment such as dust and corrosion, mechanical protection such as strength, and ensuring insulation between the combination 10 and surrounding members. Play. In this case, the end 2e of the winding 2w is pulled out and exposed from the resin coating 5. The constituent material of the resin coating 5 is preferably excellent in electrical insulation, thermal conductivity, and impact resistance, and examples thereof include epoxy resin, urethane resin, and silicone resin. Further, as a constituent material of the resin coating portion 5, a filler having excellent insulation and thermal conductivity, for example, at least one ceramic selected from silicon nitride, alumina, aluminum nitride, boron nitride, mullite, and silicon carbide is used. If the filler which becomes becomes, heat dissipation is further improved.

  Here, the resin coating portion 5 has a substantially rectangular parallelepiped shape equivalent to the shape of the combination 10. The distance from the outer periphery of the combined body 10 to the surface of the resin coating portion 5 is preferably substantially uniform over the surface of the reactor 1 (excluding the lower surface, which is the installation surface of the reactor 1 here). The smaller this interval is, the easier the heat generated in the combined body 10 is released to the outside through the resin coating portion 5. The resin coating portion 5 includes a plurality of ventilation grooves 6 extending from one end side toward the other end side along the surface thereof. The ventilation grooves 6 are all formed in parallel.

(Ventilation groove)
By providing the ventilation groove 6 on the surface of the resin coating portion 5, the surface area of the resin coating portion 5 can be increased and the contact area with the wind can be increased. The direction in which the ventilation groove 6 extends can be changed depending on the object to be air-cooled more effectively. Here, a ventilation groove 6 is provided along the axial direction of the coil 2, and the coil 2 is configured to be more effectively air-cooled by flowing air from the direction indicated by the arrow in FIG. The outer peripheral surface of the assembly 10 is parallel to the axial direction of the coil 2 (excluding the side surface, the upper surface, and the lower surface that is the reactor installation surface), and the surface orthogonal to the axial direction of the coil 2 (one is the front surface and the other is the rear surface). ), The ventilation groove 6 is formed on the surface of the resin coating portion 5 covering the three surfaces of the side surface and the upper surface. Here, since the surface of the resin coating portion 5 is not curved and is the ventilation groove 6 along the axial direction of the coil, the ventilation groove 6 is a straight groove. Here, as for the surface of the resin coating | coated part 5, a side surface and an upper surface are uneven surfaces, and a front surface and a rear surface are planes.

  Examples of the cross-sectional shape of the ventilation groove 6 include a curved surface shape such as a semicircular shape, a rectangular shape, a V shape, and other polygonal shapes. Here, the cross-sectional shape of the ventilation groove 6 is a semicircular curved surface shape. The resin-coated portion 5 having the ventilation grooves 6 has a corrugated uneven shape when viewed in cross-sectional shape. In this case, the wave formation pitch and the like may be appropriately selected. The number of ventilation grooves 6 and the difference between the peak and valley portions of the ventilation grooves 6 take into account the moldability of the resin coating part 5 and the surface area of the resin coating part 5 is increased compared to the case where it is a flat surface. Such a value is preferable.

  Here, although the ventilation groove 6 is provided substantially along the axial direction of the coil 2, the ventilation groove 6 may be provided along a direction substantially orthogonal to the axial direction of the coil 2. In this case, the magnetic core 3, particularly the outer core portion 32 (see FIG. 2) can be air-cooled more effectively.

  When the reactor 1 of the first embodiment is installed on a fixed object, if the ventilation groove 6 is installed so as to follow the wind direction by a blowing means such as a fan, an increase in resistance to the wind with respect to the resin coating portion 5 having the ventilation groove 6 is prevented. be able to. Moreover, since the fall of a wind speed can be prevented and the fall of the heat transfer rate of air can be prevented, it is excellent in air cooling performance. The wind from the air blowing means such as a fan is preferably cold air.

[Reactor manufacturing method]
A method of manufacturing the reactor 1 having the above configuration will be described in detail below based on FIG.

(Preparation process)
The coil 2, the inner core 31, and the outer core 32 (see FIG. 2) described above are combined to prepare the combined body 10.

(Arrangement process)
The arranging step includes an outer container 100 and an inner mold 200 arranged in the outer container 100, and the combined body 10 prepared in the preparing step is arranged in the inner mold 200.

≪Outer container≫
The outer container 100 is used to fix the inner mold 200, which will be described later, so that the divided pieces 210 of the inner mold 200 are not separated because the inner mold 200 is formed of the divided pieces 210. As shown in FIG. 3B, the outer container 100 includes an opening 110 and a plurality of extrusion holes 130 in the bottom plate 120 facing the opening 110. Here, the outer container 100 has a rectangular parallelepiped shape, and has an opening 110 on the upper surface. Four extrusion holes 130 are provided in the bottom plate 120 facing the opening 110. The extrusion hole 130 is used in a take-out process described later.

≪Inner mold ≫
The inner mold 200 is used to form the resin coating portion 5 (see FIG. 1) having the ventilation grooves 6 on the outer periphery of the combined body 10. As shown in FIG. 3 (A), the inner mold 200 is formed of a plurality of divided pieces 210 that form a resin filling space to be the resin coating portion 5. At least one of the divided pieces 210 has a protrusion 220 for forming the ventilation groove 6 (see FIG. 1) along the surface of the molded product (reactor 1). Further, at least one of the divided pieces 210 has a resin injection hole 230 for injecting the resin into the filling space. The resin injection hole 230 can inject a resin into the filling space, and the size and location of the resin injection hole 230 are not particularly limited as long as the formation of the resin coating portion 5 is not affected. Further, in the molded product (reactor 1), the terminal hole 240 through which the winding end 2e is passed in order to draw the end 2e of the winding 2w from the assembly 10 and expose it from the resin coating 5 (see FIG. 1). Are provided on the split piece 210 by the number of the winding end portions 2e. The terminal hole 240 may have a size such that the winding end 2e is inserted and does not wobble. Since the location of the end 2e is determined, the split piece 210 is formed so that the terminal hole 240 is located at the location corresponding to the location.

  When these divided pieces 210 are combined, the divided pieces 210 are configured such that the plurality of protrusions 220 are all formed in parallel. Here, the divided piece 210 includes an uneven plate serving as both side surfaces, a flat plate serving as a front and back surfaces, a fixed plate serving as a bottom surface, and a top plate serving as a lid. A plurality of protrusions 220 are formed in parallel on the concavo-convex plate and the top plate, and inclined surfaces that are compatible with each other are formed on the upper edge portion of the concavo-convex plate and the side edge portion of the top plate. The upper surface of the fixed plate has a rectangular frame-shaped notch at the peripheral edge thereof, and an uneven plate and a flat plate are arranged in the notch to position them. The inner mold 200 is formed by fixing a concavo-convex plate and a flat plate on a fixed plate so as to face each other, and placing a top plate on the fixed plate so as to face the fixed plate. At this time, the protrusions 220 formed on the inner surface of the inner mold 200 are all parallel.

  In the arranging step, first, the fixing plate, the concavo-convex plate, and the flat plate are fixed in each position in the outer container 100, and each plate is formed into a box-like body. Next, the combined body 10 is put in the box-shaped body. At this time, it arrange | positions so that the direction of the ventilation groove | channel 6 formed in the resin coating | coated part 5 of a molding (reactor 1) may turn into a desired direction. Here, since it is desired to form the ventilation groove 6 along the axial direction of the coil 2, the axial direction of the coil 2 and all the protrusions 220 are arranged in parallel. Then, the box-shaped body containing the combined body 10 is covered with a top plate. At this time, the winding end 2e is inserted into the terminal hole 240. As described above, the combined body 10 can be stably installed in the inner mold 200 as shown in FIG. The inner mold 200 is formed without gaps by the divided pieces 210, but it is preferable to connect the divided pieces 210 so that the divided pieces 210 can be easily disassembled in a subsequent removal step.

(Molding process)
It is possible to obtain a molded product (reactor 1) by integrating the assembly 10 and the resin by press-fitting a thermosetting resin from the resin injection hole 230 into the inner mold 200 having the assembly 10 therein, and curing the resin. it can. When the resin is injected from the resin injection hole 230 into the inner mold 200, the terminal hole 240 can also be used as an air vent hole for extracting air from the resin.

(Removal process)
Finally, the molded product (reactor 1) is taken out from the inner mold 200. First, the inner mold 200 is taken out from the outer container 100. The method applies a force to the inner mold 200 through the extrusion holes 130 formed in the bottom plate 120 of the outer container 100. For example, the inner mold 200 can be taken out from the outer container 100 by extruding with a rod-shaped body having a thickness that can be inserted into the extrusion hole 130. As long as the inner mold 200 can be taken out from the outer container 100, the size and number of the extrusion holes 130 are not particularly limited. Next, the molded product (reactor 1) can be taken out of the inner mold 200 by removing the divided pieces 210 constituting the inner mold 200 from the molded product (reactor 1).

[effect]
The reactor 1 of the present invention can increase the surface area of the resin coating portion 5 by forming the ventilation groove 6 on the surface of the resin coating portion 5. Therefore, since the contact area with the wind can be increased, the heat generated in the combined body 10 can be efficiently released through the resin coating portion 5. Further, by forming all the ventilation grooves 6 in parallel, it is possible to prevent a decrease in wind speed and a decrease in heat transfer coefficient of air. Therefore, the reactor 1 of the present invention is excellent in air cooling performance.

  In the manufacturing method of the reactor 1 of the present invention, since the outer surface of the reactor 1 of the present invention has an uneven shape by the ventilation groove 6, the inner mold 200 that is a molding die of the resin coating portion 5 is formed by the divided pieces 210. Thus, the reactor 1 of the present invention can be manufactured efficiently. Since the inner mold 200 is formed of the divided pieces 210, the reactor 1 having a large number of ventilation grooves 5 in the resin coating portion 5 can be easily taken out from the inner mold 200.

<Embodiment 2>
Next, the reactor 1a of the second embodiment will be described with reference to FIG. The reactor 1a of the second embodiment is different from the first embodiment in the shape of the resin coating portion 5 that covers the outer periphery of the combined body 10. Hereinafter, this difference will be mainly described, and the other configuration is the same as that of the reactor 1 of the first embodiment, and the description thereof will be omitted.

[Resin coating]
The resin coating portion 5 has a streamline shape. The shape is a tapered shape in which at least one end side of the resin coating portion 5 protrudes from the surface of the one end side of the assembly 10. For example, the protruding portion may be a cone shape having a tapered surface or a substantially spindle shape. FIG. 4 shows the case of a substantially spindle shape. In this case, in the plan view of the reactor 1a, as shown in FIG. 4 (Aa), the resin coating portion 5 is generally streamlined and has an oval shape. As another shape, as shown in FIG. 4 (Ab), both end sides of the resin coating portion 5 are tapered and projecting from the surface of the combined body 10, and the resin coating portion The side surface of 5 is a flat surface. Here, the both end sides of the resin coating portion 5 are the sides that cover the outer peripheral surface of the combined body 10 and the surfaces perpendicular to the axial direction of the coil 2 (one on the front surface and the other on the rear surface). The side surface side of the resin coating portion 5 is the side covering the surface parallel to the axial direction of the coil 2 (here, excluding the upper surface of the resin coating portion 5) on the outer peripheral surface of the combined body 10. Further, as shown in FIG. 4 (Ba), the side view of the reactor 1a includes a shape in which the protruding portion tapers toward a substantially central axis connecting both surfaces from the front surface and the rear surface of the combined body 10. As another shape, as shown in FIG. 4 (Bb), in the reactor 1a shown in FIG. 4 (Ba), the resin coating portion that covers the surface (upper surface) parallel to the axial direction of the coil 2 on the outer peripheral surface of the combined body 10 5 includes a shape that is a flat surface along the surface of the combined body 10. As another shape, as shown in FIGS. 4 (Bc) and 4 (Bd), there is a shape in which the protruding portions taper from the front surface and the rear surface of the combined body 10 toward the installation surface of the reactor 1a. As an overall form of the reactor 1a, each combination of a plan view of the reactor 1a (Fig. 4 (Aa), Fig. 4 (Ab)) and a side view of the reactor 1a (Figs. 4 (Ba) to 4 (Bd)) ( Here, there are 8 ways).

  In FIG. 4, the both ends of the resin coating portion 5 on both ends of the one end side and the other end side have been described to have a tapered shape that protrudes from the respective surfaces of the assembly 10. The other end side may be a flat surface along the surface of the combined body 10, for example. It is easier to obtain the effect when the protruding portion is provided on the front surface of the combined body 10 when viewed from a blowing means such as a fan.

(Ventilation groove)
With reference to FIG. 5, an example of the reactor 1a according to the second embodiment is shown, and the structure of the ventilation groove 6 formed in the reactor 1a will be described. Reactor 1a shown in FIG. 5 is a reactor depicted in FIG. 4 by a combination of plan view 4 (Aa) and side view 4 (Bc) of reactor 1a, and a combination of a coil and a magnetic core is omitted. ing. That is, the reactor 1a shown in FIG. 5 has a half-oval shape in which the resin coating portion 5 is generally streamlined. FIG. 5 (A) shows a cross-sectional view of the reactor 1a. The ventilation groove 6 formed in the resin coating portion 5 of the reactor 1a is a curved groove along the surface shape of the resin coating portion 5. FIG. As shown in FIG. 5 (B), one ventilation groove 6 forms a single plane 8 formed by a straight line group 9 connecting any two points along the ventilation groove 6, and this plane 8 and the later-described The installation reference line 7 is formed in parallel. That is, each ventilation groove 6 has a curved shape along the surface of the resin coating portion 5, but the ventilation groove 6 is substantially along the installation reference line 7 and does not meander. Therefore, in FIG. 4, when the wind flows from the direction indicated by the arrow, if the reactor is installed so that the installation reference line 7 is along the wind direction, the ventilation groove 6 is almost along the wind. As shown in FIG. 5 (A), when the installation reference line 7 is defined at the center in the width direction on the installation surface of the reactor 1a, both the one end side and the other end side of the ventilation groove 6 are on the installation reference line 7. The form formed so that it may concentrate is mentioned. In this case, the ventilation groove is radially formed along the surface from the tapered portion of the tip portion of the resin coating portion 5 toward the one end side of the combined body 10. In addition, there is a form in which each ventilation groove 6 is an arc groove formed on a plane parallel to the installation reference line 7 and perpendicular to the installation surface of the reactor 1a. In addition, as long as the ventilation groove has a curved shape along the surface of the resin coating portion 5, the length of the ventilation groove is not particularly limited. For example, the ventilation groove 6 may be formed not only over the entire length from one end of the resin coating portion 5 to the other end but only in the middle of the surface of the resin coating portion 5.

(Installation reference line)
The installation reference line 7 is a straight line on the installation surface of the reactor 1a, and is a straight line that serves as a reference for the installation direction of the reactor 1a. When the reactor 1a is installed with respect to a blowing means such as a fan, the reactor 1a is installed so that the installation reference line 7 is along the wind direction.

  In the case where at least one end side of the resin coating portion 5 has a tapered shape projecting from the surface of the one end side of the assembly 10, the flow of wind is improved without forming a ventilation groove in the projecting projecting portion. It leads to. Of course, it is more preferable to form a ventilation groove.

  Here, although the form which provided the ventilation groove | channel along the axial direction of the coil 2 was demonstrated, you may provide a ventilation groove | channel along the direction orthogonal to the axial direction of a coil substantially. In this case, the magnetic core 3 can be air-cooled more effectively.

[effect]
In the reactor 1a according to the second embodiment, the resin coating portion 5 has a streamline shape, and in particular, at least one end side of the resin coating portion 5 is tapered so as to protrude from the surface of the one end side of the combined body 10. The resistance to the wind can be reduced, and the wind speed in the vicinity of the surface of the resin coating can be increased. Furthermore, when the protruding portion of the resin coating portion 5 is provided on the front surface of the combined body 10 when viewed from the air blowing means such as a fan, the flow of wind can be improved and the wind speed can be increased in the entire reactor 1a. By preventing an increase in resistance to the wind of the resin coating portion 5 having the ventilation grooves, the wind speed can be increased, and the heat transfer rate of air can be improved. Therefore, the reactor 1a of the second embodiment can increase both the heat radiation area of the resin coating portion 5 and the heat transfer coefficient of air, and can further improve the air cooling performance.

<Example of trial calculation>
[Calculation conditions]
The contact area between the resin coating portion and the wind was calculated using a reactor having a ventilation groove formed on the surface of the resin coating portion, and the thermal resistance between the reactor and air was determined. Moreover, the same calculation was performed using the reactor which does not have a ventilation groove | channel on the surface of a resin coating part.

  As a trial calculation example, the reactor of Fig. 1 was used. When the cross-sectional shape of the resin-coated portion having the ventilation groove is seen, it has a corrugated uneven shape, the wavelength is 10 mm, and the amplitude is 5 mm. And five ventilation grooves were formed on each surface.

  The comparative example has the same form as the trial calculation example except that the surface of the resin coating portion is a flat surface not provided with a ventilation groove.

[result]
The surface area of the resin coating portion in the trial calculation example was 23864 mm ² , while the surface area of the resin coating portion in the comparative example was 15200 mm ² . Therefore, the heat radiation area could be increased by about 57% by forming the ventilation groove in the resin coating portion. Therefore, when the wind speed on the surface of the reactor is the same, forming a ventilation groove has an effect of reducing the thermal resistance between the reactor and the wind by about 36%.

  The reason why the trial calculation example was able to reduce the thermal resistance as compared with the comparative example is considered to be that the heat radiation area of the reactor could be increased by forming the ventilation groove in the resin coating portion. Further, since all the plurality of formed ventilation grooves are parallel to each other, it is possible to prevent a local decrease in the wind speed, which is considered to be due to the prevention of a decrease in the air heat transfer coefficient.

  The above-described embodiment can be appropriately changed without departing from the gist of the present invention, and is not limited to the above-described configuration.

  The reactor of the present invention can be suitably used for a component part of a power conversion device such as a vehicle-mounted converter mounted on a vehicle such as a hybrid vehicle, an electric vehicle, or a fuel cell vehicle.

1,1a reactor
2 Coil 2a, 2b Coil element 2w Winding 2e Winding end
3 Magnetic core 31 Inner core 32 Outer core
4 Bobbin 41 Cylindrical bobbin 42 Frame bobbin 43 Gap material
5 Resin coating
6 Ventilation groove
7 Installation reference line 8 Plane 9 Line group
10 Union
100 Outer container 110 Opening 120 Bottom plate 130 Extrusion hole
200 Inner mold 210 Divided piece 220 Projection 230 Resin injection hole 240 Terminal hole

Claims (7)

A reactor comprising a coil formed by winding a winding, a magnetic core disposed at least inside the coil, and a resin coating that covers an outer periphery of the combined body of the coil and the magnetic core,
A plurality of ventilation grooves extending from one end side toward the other end side along the surface of the resin coating portion,
A reactor characterized in that all the ventilation grooves are formed in parallel. When the installation reference line that is a straight line on the installation surface of the reactor and defines the reference of the installation direction of the reactor,
2. The ventilation groove according to claim 1, wherein a plane formed by a group of straight lines connecting any two points along the ventilation groove and the installation reference line are parallel to each other. Reactor.   3. The reactor according to claim 1, wherein the ventilation groove is a straight groove.   3. The reactor according to claim 1, wherein the ventilation groove is a curved groove.   5. The reactor according to any one of claims 1 to 4, wherein at least one end side of the resin coating portion has a tapered shape protruding from a surface of the one end side of the combined body. In the state where the reactor according to any one of claims 1 to 5 is installed on a fixed object,
The reactor installation structure, wherein the reactor is fixed so that the ventilation groove is along the wind direction. A reactor manufacturing method for manufacturing a reactor by covering the outer periphery of a combination of a coil and a magnetic core with a resin coating,
A preparation step of preparing a combination of a coil formed by winding a winding and a magnetic core disposed at least inside the coil;
Preparing a mold comprising an outer container and an inner mold disposed in the outer container, and arranging the assembly in the inner mold; and
A molding step of obtaining a molded product in which the assembly and the resin are integrated by injecting a resin into the inner mold and curing the resin;
A removal step of removing the molded product from the inner mold,
In the arrangement step,
The outer container has a plurality of extrusion holes in the opening and the bottom plate facing the opening,
The inner mold includes a plurality of divided pieces forming the resin filling space, and at least one of the divided pieces has a protrusion for forming a ventilation groove along the surface of the molded product, A plurality of protrusions are formed in parallel by combining one piece,
In the removing step, the inner mold is pushed out from the outer container by applying a force to the inner mold through the extrusion hole, and each divided piece constituting the inner mold is removed from the molded product.
A reactor manufacturing method characterized by the above.

Images