JP2018190910A - Reactor device and method for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inexpensive reactor device capable of enhancing productivity while securing reduction in the size and the weight, and a method for manufacturing the same.SOLUTION: A reactor device includes a dielectric component and a heat dissipation member that has a mounting surface and on which the dielectric component is arranged on the mounting surface, where the dielectric component has a reactor iron core formed by integrally connecting a plurality of split iron cores with a band and a coil having a winding part wound around the reactor iron core, the reactor iron core, the coil and the band are integrally fixed by a mold resin part, a fitting part is molded integrally with the mold resin part, and the dielectric component is arranged on the mounting surface of the heat dissipation member in a state in which the fitting part is fixed to the heat dissipation member.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a reactor device used in a power converter and a manufacturing method thereof.

  Conventionally, a reactor device has been used as a part of a power converter. For example, a reactor device has been used as a circuit component of a DC / DC voltage converter as an energy storage / release element. And when the power converter operates, heat is generated by energizing the coil of the reactor device. Therefore, the reactor is housed in a case attached to the heat sink, and a heat transfer sheet is disposed between the reactor and the inner bottom surface of the case, or the case is filled with mold resin to transfer heat generated by the reactor. Heat was transferred to the case through the heat sheet or the mold resin, further transferred to the heat radiating plate, and radiated to the outside.

  However, a case for storing the reactor is required, and there is a problem that reduction in size and weight and cost reduction cannot be avoided. Furthermore, since mold resin and a case with poor heat dissipation characteristics exist in the heat dissipation path of the reactor, there is a problem that heat generated in the reactor is not effectively dissipated.

  In view of such a situation, a reactor and a cooler having a holding part are provided, the core of the reactor is held in contact with the holding part and held by the cooler, and the heat transfer sheet is placed between the coil of the reactor and the cooler. An arranged conventional reactor device has been proposed (see, for example, Patent Document 1).

JP 2007-129146 A

  In the conventional reactor device according to Patent Document 1, the iron core structure of the reactor is not mentioned. However, the core of the reactor is configured by, for example, arranging a pair of split cores to face each other. Therefore, the reactor is assembled by connecting a pair of split iron cores with the coil attached thereto using an adhesive. Therefore, management of adhesive application amount, application thickness, application location, etc., equipment such as a furnace to cure the adhesive, and a heat treatment process are required, resulting in deterioration in productivity and cost reduction. .

  This invention was made in order to solve such a subject, Comprising: It aims at obtaining the inexpensive reactor apparatus which can improve productivity, and its manufacturing method, ensuring a small size and weight reduction.

  A reactor device according to the present invention includes a derivative component and a mounting surface, and the derivative component is disposed on the mounting surface, and the derivative component includes a plurality of divided iron cores integrated with a band. A reactor core configured by being connected, and a coil having a winding portion wound around the reactor core, and the reactor core, the coil and the band are integrally fixed by a mold resin portion, A mounting portion is formed integrally with the mold resin portion, and the derivative component is disposed on the mounting surface of the heat radiating member in a state where the mounting portion is fixed to the heat radiating member.

According to this invention, since the band for integrally connecting the plurality of divided iron cores is fixed together with the derivative part by the mold resin portion, an adhesive for integrally connecting the plurality of divided iron cores becomes unnecessary. This eliminates the need for management of the adhesive application amount, application thickness, application location, etc., equipment such as a furnace for curing the adhesive, and a heat treatment step, which increases productivity and reduces costs. .
In addition, a case for storing the derivative component is not required, and the size and weight can be reduced.

It is a perspective view which shows the reactor apparatus which concerns on Embodiment 1 of this invention. It is a bottom view of the reactor apparatus which concerns on Embodiment 1 of this invention. It is a disassembled perspective view explaining the structure of the reactor apparatus which concerns on Embodiment 1 of this invention. It is a perspective view which shows the state by which the reactor apparatus which concerns on Embodiment 1 of this invention was mounted in the heat radiating member. It is sectional drawing in the A-A 'surface of FIG. It is sectional drawing in the B-B 'surface of FIG. It is a perspective view which shows the derivative components of the reactor apparatus which concerns on Embodiment 1 of this invention. It is process drawing explaining the manufacturing method of the reactor apparatus which concerns on Embodiment 1 of this invention. It is a perspective view which shows the reactor apparatus which concerns on Embodiment 2 of this invention. It is sectional drawing which shows the reactor apparatus which concerns on Embodiment 2 of this invention.

Embodiment 1 FIG.
1 is a perspective view showing a reactor device according to Embodiment 1 of the present invention, FIG. 2 is a bottom view of the reactor device according to Embodiment 1 of the present invention, and FIG. 3 is a reactor according to Embodiment 1 of the present invention. 4 is an exploded perspective view for explaining the configuration of the apparatus, FIG. 4 is a perspective view showing a state in which the reactor apparatus according to Embodiment 1 of the present invention is mounted on a heat radiating member, and FIG. 6 is a cross-sectional view taken along the plane BB ′ of FIG. 4, FIG. 7 is a perspective view showing a derivative component of the reactor device according to the first embodiment of the present invention, and FIG. 8 is a first embodiment of the present invention. It is process drawing explaining the manufacturing method of the reactor apparatus which concerns.

  As shown in FIG. 3, reactor device 100 is arranged between coil 1, reactor iron core 4 to which coil 1 is mounted, and between reactor iron core 4 and coil 1, and between reactor iron core 4 and coil 1. A dielectric part 10 having a pair of insulating bobbins 2 that secures electrical insulation, a band 8 (not shown) in which the dielectric part 10 is integrated, and heat transfer from the dielectric part 10 to the outside. A heat sheet 6 and a molded resin part 5 (not shown) for fixing the derivative component 10, the band 8 and the heat transfer sheet 6 together are provided.

The coil 1 is manufactured by winding a flat coil wire in an edgewise manner. Both end portions of the coil wire extend from the winding portion 1c to become the first terminal 1a and the second terminal 1b. The coil wire is a copper wire that is insulation-coated with an enamel material.
Each of the pair of insulating bobbins 2 includes a hollow cylindrical portion 2a and a flange portion 2b that protrudes radially outward from one axial end of the cylindrical portion 2a. Each insulating bobbin 2 is formed of a thermoplastic resin such as PPS (Polyphenylene Sulfide) resin, PBT (Poly Butylene Terephthalate) resin, and has electrical insulation.

The reactor core 4 is composed of a pair of split cores 3. The pair of split iron cores 3 includes a center leg 3a, a pair of outer legs 3b opposed to each other with the center leg 3a interposed therebetween and arranged in parallel to each other, a center leg 3a, and a pair of outer legs. It is comprised in the E type | mold which has the connection part 3c which connects the one end part of the length direction of the part 3b. The pair of split iron cores 3 are made of the same shape and the same size by a single processing device using a soft magnetic material. The split iron core 3 is, for example, a dust core made of a material such as iron dust, sendust, ferrite, or permalloy, or a laminated iron core made of an electromagnetic steel plate.
The band 8 is made of a nonmagnetic material and has elasticity. For the band 8, for example, a polyimide film tape, a binding band, or the like is used.

  And the cylindrical part 2a of a pair of insulation bobbin 2 is inserted in the winding part 1c from the both sides of the axial direction of the winding part 1c of the coil 1. FIG. Central leg portions 3 a of the pair of split iron cores 3 are inserted into the cylindrical portions 2 a of the pair of insulating bobbins 2 from both sides in the axial direction of the winding portion 1 c of the coil 1. And a pair of division | segmentation iron core 3 is arrange | positioned so that center leg part 3a and outer leg part 3b may be made to oppose. A winding portion 1 c of the coil 1 is attached to the central leg portion 3 a of the pair of split iron cores 3 via the cylindrical portions 2 a of the pair of insulating bobbins 2. Furthermore, the band 8 is extended and attached to the outer peripheral side of the pair of split iron cores 3 that are disposed to face each other. Accordingly, the opposing outer leg portions 3b are brought into contact with each other by the restoring force of the band 8, and the pair of split iron cores 3 are firmly connected. Further, the opposed cylindrical portions 2a are in contact with each other, the flange portions 2b are in contact with the connection portions 3c, and the pair of insulating bobbins 2 are mounted on the pair of split iron cores 3. At this time, a minute gap is formed between the opposed central leg portions 3a, but they may be in contact with each other. Thereby, the dielectric component 10 is assembled as shown in FIG.

  As shown in FIGS. 1 and 2, the reactor device 100 is manufactured by molding the derivative component 10 to which the band 8 is attached and the heat transfer sheet 6. As a result, the dielectric component 10, the band 8, and the heat transfer sheet 6 are integrally fixed by the mold resin portion 5.

  The derivative component 10 and the band 8 are embedded in the mold resin portion 5 and their components are firmly connected. The first terminal 1 a and the second terminal 1 b which are both ends of the coil 1 protrude from the upper surface of the mold resin portion 5. An attachment portion 50 having an attachment hole 50 a is formed at the same time as molding of the mold resin portion 5 at the lower end of the opposed peripheral wall of the mold resin portion 5. One surface of the heat transfer sheet 6 is in contact with the lower surface of the winding portion 1 c of the coil 1 and the lower surface of the outer leg portion 3 b of the pair of split iron cores 3, and a part of the other surface is exposed from the lower surface of the mold resin portion 5. Embedded in the mold resin part 5. Here, the region on the other side of the heat transfer sheet 6 opposite to the winding portion 1c of the coil 1 is exposed from the lower surface of the mold resin portion 5, and the heat generated in the coil 1 is effectively applied to the heat sink 7 as a heat radiating member. Heat is transferred to. In order to effectively transfer heat generated in the split iron core 3 to the heat sink 7, a region of the other surface of the heat transfer sheet 6 opposite to the outer leg 3 b of the split iron core 3 is formed on the mold resin portion 5. It is preferable to expose from the lower surface.

  Here, the heat transfer sheet 6 has a function of ensuring electrical insulation between the coil 1 and the heat sink 7 and transferring heat generated in the coil 1 and the split iron core 3 to the heat sink 7. Therefore, the heat transfer sheet 6 is made into a sheet shape using, for example, a silicone resin mixed with a filler material having a high thermal conductivity, and has a higher thermal conductivity than the mold resin portion 5. Further, the heat transfer sheet 6 has a thickness that can secure an insulation distance between the winding portion 1c of the coil 1 and the heat sink 7 in order to ensure sufficient insulation and suppress the occurrence of product defects and failures. Is formed.

  Next, a method for manufacturing the reactor device 100 will be described with reference to FIG.

  First, the cylindrical portion 2a of the insulating bobbin 2 is inserted into the winding portion 1c of the coil 1 from both axial sides of the coil 1, and the pair of insulating bobbins 2 are attached to the coil 1 (S1). Next, the central leg 3a is inserted into the cylindrical portions 2a of the pair of insulating bobbins 2 from both axial sides of the coil 1, and the pair of split iron cores 3 are attached to the coil 1 (S2). Next, the band 8 is extended and attached so as to surround the outer peripheral side of the pair of split cores 3 arranged opposite to each other, and the pair of split cores 3 are integrally connected by the restoring force of the band 8 and the derivative part. 10 is assembled (S3). Next, the derivative component 10 is set in the casting mold (S4), and mold resin is injected into the casting mold (S5). As a result, the mold resin is filled around the derivative component 10 in the casting mold, and is filled in the divided core 3 and the coil 1. At this time, when a gap is formed between the pair of divided cores 3, the gap is impregnated with mold resin. Thus, the nonmagnetic material is disposed in the region that becomes the magnetic gap.

  Next, the casting mold is heated in a thermostatic chamber to cure the mold resin (S6). After the mold resin is cured, the derivative component 10 sealed with the mold resin portion 5 is taken out (S7), and the reactor device 100 shown in FIGS. 1 and 2 is manufactured.

  As shown in FIG. 4, the reactor device 100 thus manufactured is placed on the mounting surface 7 a of the heat sink 7, and a screw (not shown) is passed through the mounting hole 50 a of the mounting portion 50 to heat sink 7. And is attached to the heat sink 7. Thereby, as shown in FIGS. 5 and 6, the exposed portion of the heat transfer sheet 6 from the mold resin portion 5 is in contact with the mounting surface 7 a of the heat sink 7. Therefore, the lower surface of the winding portion 1 c of the coil 1 is thermally connected to the heat sink 7 via the heat transfer sheet 6. Further, the outer legs 3 b of the pair of split iron cores 3 are thermally connected to the heat sink 7 via the heat transfer sheet 6. The first terminal 1a and the second terminal 1b are electrically connected to a terminal block (not shown) provided on the heat sink 7 by welding, heat caulking, screws, or the like, and are used as a power converter. It is electrically connected to a power semiconductor element (not shown) on the primary side of the DC voltage converter. Thereby, the reactor apparatus 100 accumulate | stores or discharge | releases energy as a derivative | guide_body, and an electric current flows into the coil 1. FIG.

  Next, a heat generation phenomenon when the coil 1 of the reactor device 100 is energized will be described.

  The reactor device 100 applied to the DC / DC voltage converter is configured so that the power semiconductor element of the DC / DC voltage converter is switched to be switched between an open state and a short-circuit state, so that the first terminal 1a of the coil 1 The potential difference with respect to the second terminal 1b is adjusted. By adjusting this potential difference, the amount of increase or decrease of the current flowing through the coil 1 is controlled, and further, the accumulation or release of energy stored in the reactor device 100 is adjusted, and the reactor device 100 converts the voltage. At this time, increase / decrease in the current flowing through the coil 1 or switching of the polarity occurs, and the amount of magnetic flux passing through the magnetic path in the pair of split cores 3 changes.

  The operating point of the pair of split iron cores 3 moves on the BH characteristic indicating the relationship between the magnetic flux density (B) and the magnetic field strength (H) by changing the amount of magnetic flux. At this time, a loss corresponding to the area of the region represented by the movement locus of the operating point is generated as a hysteresis loss of the pair of split iron cores 3 due to the magnetic hysteresis property. In addition, a vortex current that tries to moderate the magnetic flux change flows in the pair of split cores 3 with respect to the temporal change dΦcr / dt of the magnetic flux (Φcr) passing through the pair of split cores 3. A loss due to the eddy current flowing through the eddy current path is generated as an eddy current loss. The combined loss of hysteresis loss and eddy current loss is called iron loss, and the pair of split cores 3 generate heat.

  There are various measures to reduce eddy current loss in the pair of split cores 3. For example, when an electromagnetic steel sheet is used as the magnetic material of the split iron core 3, the loop diameter of the eddy current is reduced by laminating thin sheets of the electromagnetic steel sheet with an insulating coating formed on the surface layer, thereby reducing eddy current loss. Can do. Also, when using iron dust material as the magnetic material of the split iron core 3, the particle size of the iron dust material is reduced to about 100 μm or less, and an insulating coating is formed on the surface of each particle to insulate the particles. Thus, eddy current loss can be reduced.

  Further, when conducting current through the coil 1, a loss occurs due to the electrical resistance of the coil 1. This loss includes a DC component resulting from conduction of a direct current and an AC component resulting from conduction of an alternating current due to a change in increase or decrease in current. The cause of the AC component of the loss is the vortex generated inside the coil wire due to the temporal change dΦi / dt of the magnetic flux (Φi) induced in the coil wire of the coil 1 so as to prevent the current from increasing or decreasing. Due to the current, a phenomenon called a skin effect occurs in which the current is less likely to be conducted in the central portion of the coil wire. Moreover, in the winding part 1c of the coil 1, since the coil strands are adjacent to each other, a phenomenon called a proximity effect in which current flows to the surface portions of the coil strands is generated.

  Further, the leakage magnetic flux in the magnetic gap between the opposed central leg 3a and the outer leg 3b of the pair of split iron cores 3 is linked to the coil wire of the coil 1, thereby generating vortices generated in the coil wire. There is a phenomenon in which loss occurs due to current. The higher the current increase / decrease frequency, the higher the interlinkage frequency fs of the leakage magnetic flux. Thereby, the AC component of the loss of the coil 1 is increased. The total loss of the DC component and the AC component of the coil 1 is referred to as copper loss, which causes the coil 1 to generate heat.

.
Reactor device 100 applied to a power converter for an electric power train of an automobile is required to achieve higher power density and higher current density than reactor device 100 for other uses. However, if the current density is higher, the loss generated by the main body of the derivative component 10 is not reduced, and the temperature rise inside the derivative component 10 tends to increase. In this way, in order to handle a large amount of power while being small, the heat generated by the dielectric component 10 is efficiently radiated, and the deterioration of the insulating property of the enamel coating due to the temperature rise of the coil 1 is suppressed, so that the desired lifetime It is necessary not to cause a failure. The variation in the heat dissipation performance leads to individual variations in the temperature rise of the coil 1 and the mold resin part 5, and it is difficult to raise the instantaneous rating.

  Thus, the split iron core 3 and the coil 1 which are magnetic bodies generate heat. In the conventional reactor device, the heat transfer sheet 6 disposed so as to be in contact with the outer leg portion 3 b of the split iron core 3 and the winding portion of the coil 1 is completely embedded in the mold resin portion 5. Therefore, the heat generated in the split iron core 3 and the coil 1, which are magnetic materials, is transferred to the heat sink 7 through the heat transfer sheet 6 and the mold resin portion 5, and is radiated from the heat sink 7.

In the first embodiment, the mold resin portion 5 is such that the heat transfer sheet 6 is in contact with the outer leg portion 3 b of the split iron core 3 and the winding portion 1 c of the coil 1 and a part thereof is exposed from the mold resin portion 5. Embedded in. The reactor device 100 is attached to the heat sink 7 so that the exposed portion of the heat transfer sheet 6 from the mold resin portion 5 is in contact with the heat sink 7. Therefore, heat generated in the split iron core 3 and the coil 1 is transferred to the heat sink 7 via the heat transfer sheet 6 and is radiated from the heat sink 7. Thus, in reactor device 100, compared with the conventional reactor device, the heat dissipation path is reduced, and the heat dissipation performance of derivative component 10 is improved.
Moreover, since the heat generated in the split iron core 3 and the coil 1 is radiated to the outside air through the mold resin portion 5 that covers the outside of the derivative component 10, the heat dissipation of the derivative component 10 is improved.

  Since the reactor device 100 does not require a case for housing the derivative component 10, it is possible to reduce the size and weight and to reduce the cost.

As described above, the reactor device 100 can ensure the excellent heat dissipation of the derivative component 10, and therefore suppresses the temperature rise of the derivative component 10 even when applied to a power converter for an electric powertrain of an automobile that handles large electric power. And high reliability can be ensured.
Moreover, since the dielectric component 10 is integrally covered with the mold resin portion 5, magnetostriction and the like are suppressed with respect to the silence required by the reactor device 100 applied to a power converter for an electric power train of an automobile. It becomes possible.

In addition, since the mounting portion 50 for mounting the reactor device 100 to the heat sink 7 is provided integrally with the mold resin portion 5, the mounting portion 50 is not displaced with respect to vibration in each direction during operation. The reactor device 100 can be stably held on the heat sink 7.
Further, since a part of the heat transfer sheet 6 in contact with the split iron core 3 and the coil 1 is exposed on the mounting surface of the mold resin portion 5 on the heat sink 7, only by mounting the reactor device 100 on the heat sink 7, a derivative component Ten heat dissipation structures can be constructed.

  Prior to the sealing step by the mold resin portion 5, the pair of split iron cores 3 are fastened and fixed using a band 8. Thereby, the adhesive agent for fixing a pair of division | segmentation iron cores 3 mutually required which was required in the prior art becomes unnecessary. Accordingly, the management of the adhesive application amount, application thickness, application location, etc., the furnace for curing the adhesive, the heat treatment process, etc. can be omitted, so that the process can be simplified and the productivity is increased. At the same time, the cost can be reduced.

  In the reactor device 100, the heat generated in the coil 1 and the split iron core 3 is transferred to the heat sink 7 via the heat transfer sheet 6, so that the mold resin portion 5 is not required to have thermal conductivity. Therefore, an inexpensive material can be used as the mold resin portion 5, and the cost of the reactor device 100 can be reduced. Here, if a material exhibiting high rigidity after curing is also used as the mold resin portion 5, the mechanical strength of the reactor device 100 can be increased. In addition, if a low-viscosity material that makes it difficult to transmit the vibration of the split iron core 3 or a high-specific gravity material that requires energy for vibration is used as the mold resin portion 5, the electromagnetic noise of the reactor device 100 can be reduced.

Embodiment 2. FIG.
9 is a perspective view showing a reactor device according to Embodiment 2 of the present invention, and FIG. 10 is a cross-sectional view showing the reactor device according to Embodiment 2 of the present invention.

9 and 10, the derivative component 10 is molded so that the upper side thereof is exposed from the mold resin portion 5 in a state where the band 8 is mounted.
Other configurations are the same as those in the first embodiment.

  In reactor device 200 according to the second embodiment, a case for housing derivative component 10 is not required. The attachment portion 50 is formed integrally with the mold resin portion 5. The band 8 is fixed to the mold resin portion 5 together with the derivative component 10. One surface of the heat transfer sheet 6 is in contact with the outer leg portion 3b of the split iron core 3 and the lower surface of the winding portion 1c of the coil 1, and the region opposite to the winding portion 1c of the coil 1 on the other surface is exposed. Further, it is embedded in the mold resin portion 5. Therefore, also in the second embodiment, the same effect as in the first embodiment can be obtained.

According to the second embodiment, the upper part side of the derivative component 10, that is, the part opposite to the mounting surface 7 a of the pair of split iron cores 3 and the winding part 1 c of the coil 1 is exposed from the mold resin part 5. Therefore, the amount of the mold resin portion 5 is reduced, and weight reduction and cost reduction are achieved. Furthermore, since the invention with the split iron core 3 and the coil 1 is directly radiated to the air, the heat dissipation of the derivative component 10 is improved.
Here, the height H of the mold resin portion 5 is a height at which the dielectric component 10 can be stably held against vibrations in each direction during operation.

In each of the above-described embodiments, the reactor core is configured with a pair of E-type split cores facing each other. However, the reactor core has an I-type split core and an E-type split core outside the pair of outer sides. You may arrange | position and comprise so that a leg part may be connected.
Moreover, in each said embodiment, although the reactor core is divided | segmented into two division | segmentation iron cores, the division | segmentation number of an iron core is not limited to two.
Moreover, in each said embodiment, although the attachment part made from a mold resin is integrally formed in the mold resin part, it is good also as an attachment part by insert-molding an attachment metal fitting to a mold resin part.

In each of the above embodiments, an outer iron core is used as the reactor core, but an inner iron core may be used.
Further, in each of the above embodiments, the mold resin is impregnated in the gap formed between the pair of split iron cores at the time of molding the derivative part. However, prior to molding, a pair of non-magnetic materials such as ceramics is used. You may arrange | position in the clearance gap between these division | segmentation iron cores.

  DESCRIPTION OF SYMBOLS 1 Coil, 1c winding part, 3 division | segmentation iron core, 5 Mold resin part, 6 Heat-transfer sheet | seat, 7 Heat sink (heat radiating member), 7a Mounting surface, 8 bands, 10 derivative parts, 50 attachment part.

Claims (6)

Derivative parts,
A heat dissipating member having a mounting surface, and the derivative component disposed on the mounting surface,
The derivative component includes a reactor core configured by integrally connecting a plurality of divided iron cores with a band, and a coil having a winding portion wound around the reactor core,
The reactor core, the coil, and the band are fixed integrally by a mold resin portion,
The mounting part is molded integrally with the mold resin part,
The derivative component is a reactor device disposed on the mounting surface of the heat dissipation member in a state where the attachment portion is fixed to the heat dissipation member. A heat transfer sheet embedded in the mold resin part in a state in contact with the winding part,
The reactor device according to claim 1, wherein a part of the heat transfer sheet is exposed from the mold resin portion and is in contact with the mounting surface.   The reactor device according to claim 2, wherein the heat transfer sheet is in contact with the reactor core.   The reactor device according to any one of claims 1 to 3, wherein a portion of the reactor iron core and the winding portion opposite to the mounting surface are exposed from the mold resin portion.   The reactor device according to any one of claims 1 to 4, wherein the attachment portion is formed on the mounting surface side of the peripheral wall of the mold resin portion. In the method of manufacturing a reactor device produced by molding a derivative part having a reactor core composed of a plurality of split cores and a coil wound around the reactor core,
Prior to the molding process of the reactor core and the coil wound around the reactor core, stretchable bands are stretched and attached to the plurality of split cores, and the plurality of the cores are restored by the restoring force of the bands. The manufacturing method of the reactor apparatus which has the process of connecting a division | segmentation iron core integrally.

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