WO2010067414A1

WO2010067414A1 - Reactor and method for manufacturing the same

Info

Publication number: WO2010067414A1
Application number: PCT/JP2008/072290
Authority: WO
Inventors: 佐藤豊幸
Original assignee: トヨタ自動車株式会社
Priority date: 2008-12-09
Filing date: 2008-12-09
Publication date: 2010-06-17

Abstract

A reactor and a method for manufacturing the reactor, in which a process for forming an insulating film around a coil can be eliminated, both vibration at the time of driving a reactor and noise caused by such vibration can be reduced effectively, and thereby a sealing resin body is not cracked easily. The reactor (10) comprises a reactor core (1) consisting of two U-shaped cores (11, 11) having a U-shaped plan view and a gap layer (12) interposed between the U-shaped cores (11, 11), a coil (2) formed in bobbinless posture on the outer circumference of the reactor core (1) while having a gap (G) to the circumferential surface of the reactor core (1), a film resin body (3) formed on the outer circumference of the reactor core (1) and that of the coil (2) and in the gap (G) between the reactor core (1) and the coil (2), and a sealing resin body (4) formed on the outer circumference of the film resin body (3). The film resin body (3) has a relatively low modulus of elasticity as compared with the sealing resin body (4).

Description

Reactor and its manufacturing method

The present invention relates to a reactor mounted on an electric vehicle, a hybrid vehicle, and the like and a method for manufacturing the reactor.

A reactor of a power conversion circuit is generally housed in a housing (case) in a posture in which a coil is formed at two longitudinal portions of a reactor ring that is substantially horizontally long in plan view. This reactor core is composed of a laminate of a plurality of magnetic steel sheets or a split core consisting of dust cores, and a gap plate made of a non-magnetic material is interposed between each split core. A reactor core is formed by being bonded and fixed with an adhesive.

A heat radiating plate (heat sink) is provided on the lower surface (bottom surface) of the housing, and a cooler for recirculating cooling water and air is provided below the heat sink. In general, a structure is used in which the air is discharged from the reactor core to the outside through the heat sink and the cooler. Here, a molded sealing resin body is formed between the housing and the reactor core accommodated in the housing, and heat from the coil or the reactor core is transmitted to the heat radiating plate through the sealing resin body. Be heated.

In a conventional reactor, a resin bobbin or insulating paper is interposed between the coil and the reactor core to prevent contact between them and to ensure heat dissipation. In the form in which the bobbin is interposed and the form in which the insulating paper is interposed, the process of separately manufacturing them and the process of installing them on a U-shaped core, for example, are included in the manufacturing process. It is necessary to prepare an injection molding die, and there has been a problem that the material cost and the manufacturing cost increase in order to produce these. In addition, it is necessary to insert the insulating paper into the outer periphery of the core. However, it is difficult to position the paper as compared with the bobbin, and it is difficult to obtain the dimensional accuracy. For these reasons, the production and installation on the core require labor and cost, leading to a decrease in production efficiency.

In addition, if the issues regarding the quality of the manufactured reactor are listed, cracks are likely to occur in the bobbin due to the heat shock in the usage environment of the reactor due to the difference in linear expansion between the bobbin and the core. There was a possibility that a defect occurred and this could lead to burning of the reactor.

Insulating paper materials such as PET (polyethylene terephthalate) and PEN (polyethylene naphthalate) are generally used, but their thermal conductivity is as low as around 0.2 (W / mK), which reduces the heat dissipation of the core. It was a hindrance. For this reason, when the reactor is under a high load, heat builds up between the core and the coil, the temperature of the insulating paper rises significantly, and the deterioration progresses, which may cause insulation failure. In particular, in a reactor mounted on an electric vehicle, a hybrid vehicle, or the like, this problem becomes significant because a large current is generally applied or a large voltage is applied.

Incidentally, for example, Patent Document 1 discloses a reactor in which a coil is formed in a bobbinless posture on the outer periphery of a reactor core. The reactor disclosed in Patent Document 1 is formed by arranging fins in parallel on the outer periphery of the insulating layer on the outer periphery of the coil, and filling and fixing the resin in the gap between the core and the coil and the gap between the coil and the cover. The present invention relates to a reactor excellent in heat dissipation performance.

According to the reactor disclosed in Patent Document 1 described above, a reactor having a bobbin-less structure that has both excellent heat dissipation performance can be obtained, while a resin to be molded and a mixed material mixed with the resin are specifically specified. Absent. According to the present inventors, due to the heat conduction performance of the resin and the mixture used, in some cases, heat is trapped between the coil and the core, thereby deteriorating the resin mold, and finally insulation failure Has been identified as being at risk. Moreover, when the sealing resin body cannot absorb the difference in linear expansion between the core and the coil, cracks are generated in the sealing resin body itself, which may lead to insulation failure. Furthermore, when these reactors are used as power conversion circuits, and these are installed in the above hybrid vehicles and electric vehicles that have recently been steadily expanding their production cost Since a coil having an insulating film such as an enamel film around the conductor is provided at the periphery of the reactor core, it is possible to manufacture a reactor at a lower cost by omitting the insulating film forming step of this coil. Technology development is also eagerly awaited.

Furthermore, in addition to reducing the manufacturing cost of the reactor as described above, the generation of vibration during the reactor drive and the generation of noise due to this, and further the suppression of cracks in the sealing resin body due to vibration, etc. It is also an important issue. Here, there is also known a reactor having a structure in which a reactor (in which a coil is formed) is surrounded only by a sealing resin body without using a housing (case). However, in the structure without the housing, since the sealing resin body is expected to have a relatively high rigidity because the housing does not exist, the flexibility of the sealing resin body is inevitably lowered. Therefore, there is a fatal problem that the vibration reduction effect cannot be sufficiently expected and the generated noise cannot be suppressed. Note that there is a reactor in which the sealing resin body filled between the housing (case) and the reactor core has a two-layer structure made of a different resin, and the amount of use of the epoxy resin having high heat resistance and relatively high cost is reduced. It is disclosed in Patent Document 2. However, even if this reactor is applied, the above-mentioned problem, that is, the insulating film manufacturing process around the coil still remains, and even if the sealing resin body has a two-layer structure of different resins, the vibration of the reactor driving It is still unclear whether the generation, the noise caused by this, and the occurrence of cracks that can occur in these sealing resin bodies due to this vibration can be effectively suppressed.
JP-A-8-222442 JP 2007-134374 A

The present invention has been made in view of the above-described problems, and in addition to the manufacturing process and assembly process of bobbins and insulating paper, the insulating film forming process around the coil can be omitted, and the vibration during the reactor driving can be reduced. It is an object of the present invention to provide a reactor that can effectively reduce both noises resulting from this, and a method for manufacturing the same, that is excellent in heat dissipation performance.

In order to achieve the above object, a reactor according to the present invention includes a reactor core and a reactor including at least two U-shaped cores in a plan view and a gap layer interposed between the U-shaped cores. The coil is formed on the outer periphery of the core with a clearance from the peripheral surface of the reactor core in a bobbin-less posture, the outer periphery of the reactor core and the outer periphery of the coil, and the clearance between the reactor core and the coil. A coating resin body and a sealing resin body formed on the outer periphery of the coating resin body, and the coating resin body has a relatively low elastic modulus compared to the sealing resin body. Is.

Here, the reactor core has a configuration in which two U-shaped cores having magnetism are bonded via a gap layer, or one or more I-type cores are similarly sandwiched between two U-shaped cores via a gap layer. There is a bonded form. Furthermore, although the reactor of the present invention is mainly intended for a structure (caseless) without a housing (or case), the reactor core is accommodated in the housing, and a sealing resin body is formed in the reactor core and the housing. This does not eliminate the reactor. Therefore, in this embodiment, a housing made of aluminum or an aluminum alloy thereof can be used.

The reactor of the present invention relates to a reactor having a bobbinless structure in which a resin bobbin or insulating paper is not interposed between a coil formed on the outer periphery of the reactor core and the core, and an insulating film such as an enamel film is provided around the reactor. Unlike the conventional coil formed on the coil, the coil without the insulation film (the coil wound without the coating of the conductive wire made of copper wire or the like) is provided around the reactor core in a bobbin-less posture It is.

In order to insulate between the coil and the reactor core after the bobbin-less structure is used and the insulation film around the coil is eliminated, the reactor of the present invention includes an outer periphery of the reactor core and an outer periphery of the coil, and an outer periphery of the reactor core and the coil. A film resin body is formed between the gaps.

This coating resin body further has a relatively low elastic modulus (and therefore is relatively soft and flexible or highly deformable) as compared with the sealing resin body formed around it. Insulation between the coil and the reactor core can be achieved, and vibration from the reactor core can be effectively absorbed by the film resin body having a relatively low elastic modulus (high deformability and high vibration absorption). Thus, it is possible to attenuate the vibration and reduce the vibration transmission to the outermost sealing resin body. It is easy to understand that the generated noise is reduced by reducing the vibration transmitted to the sealing resin body. In addition, regarding insulation between the coils (conductors) on which no insulating film is formed, even if the coating resin is in an energized state without entering between the conductors, the conductors are at the same potential. Insulation is not particularly required.

Here, the material of the coating resin body is an insulating material, and in relation to the sealing resin body, it may be any elastic modulus lower than that of the sealing resin body, and is not particularly limited. For example, a resin that exhibits a rubber shape at normal temperature or a resin that exhibits a gel shape while adjusting the crosslinking density of the resin, such as a soft epoxy resin, a urethane resin, a silicone resin (including a modified silicone resin), an olefin resin, etc. Can do.

Compared to the above-mentioned coating resin body, when the sealing resin body formed around it has a caseless structure, the sealing resin body is required to have an appropriate hardness. It can be molded from a hard epoxy resin, which is a hard resin, BMC (resin made of a mixed material such as unsaturated polyester, calcium carbonate and glass fiber).

According to the reactor of the present invention described above, since the insulating paper and the bobbin are eliminated, the manufacturing process thereof can be eliminated, the manufacturing cost can be reduced, and the coating resin having a relatively low elastic modulus is formed from the reactor core. By interposing between (and the coil) and the hard sealing resin body, it is possible to reduce the vibration from the reactor core and reduce the noise caused by this. And the outermost sealing resin body has desired hardness, and it is possible to obtain the reactor of a caseless structure.

Further, as a further effect exhibited by the reactor of the present invention, by disposing the insulating film on the outer periphery of the coil and providing a coating resin body, it becomes possible to mix a conductive filler into the resin for molding the sealing resin body, and therefore As compared with a conventional reactor in which only an insulating filler can be used as a resin for molding a sealing resin body, the heat dissipation can be further enhanced.

In a reactor having a conventional structure, a coil is formed by winding a conductive wire having an insulating film formed on its outer periphery, but there is a pinhole in one layer of thin insulating film, or potting of sealing resin, etc. If the insulation film is damaged by the external pressure acting when the sealing resin body containing a conductive filler is interposed between the coil and the reactor core, the insulation between the reactor core and the coil must be secured there. Will not be able to. Therefore, in the reactor of the conventional structure, the filler mixed in order to improve the heat dissipation of a sealing resin body was limited to the insulating filler which consists of boron nitride, a silica, etc.

On the other hand, by applying the structure of the reactor of the present invention, the insulation between the reactor core and the coil is sufficiently secured by the coating resin body, so that the resin material for the sealing resin body is iron or copper, The sealing resin body can be formed by mixing conductive fillers made of aluminum or an alloy thereof, and the heat dissipation can be remarkably improved.

Here, according to the verification by the present inventors, regarding the elastic modulus of the above-mentioned film resin body, the film resin body in the range of 100 kPa to 10 MPa is used, and further, the elastic modulus of the sealing resin body on the outer periphery thereof is used. It has been proved that a high effect of reducing both vibration and noise can be obtained by setting the elastic modulus higher than that of the coating resin body.

Furthermore, it has been demonstrated that even when the thickness of the above-described coating resin body is 1 mm or more, a high reduction effect of both vibration and noise can be obtained.

The reactor of the present invention described above has excellent heat dissipation performance as described above, and vibration and noise are remarkably low. It is most suitable for application to electric vehicles.

The reactor manufacturing method according to the present invention includes at least an outer periphery of a reactor core including a U-shaped core having two U-shaped planar views and a gap layer interposed between the U-shaped cores. A first step of forming a first intermediate having a coil and a bobbin-less posture with a clearance from the peripheral surface of the reactor core, an outer periphery of the reactor core and an outer periphery of the coil, and a reactor core and a coil A sealing resin body having a higher modulus of elasticity than the coating resin body on the outer periphery of the coating resin body, and a second step of forming a coating resin body in the gap between them to form a second intermediate And forming a reactor to form a reactor.

Here, in the first step, a method of forming the first intermediate body by interposing a spacer made of the same material as the coating resin body in a part between the reactor core and the coil can be applied. .

Further, in the second step, the second intermediate is performed by performing the step of immersing the first intermediate in a container containing a resin for molding the resin film body, taking it out and drying it one or more times. A method of forming a body can also be applied.

In the third step, the sealing resin body can be formed of a material in which a conductive filler is mixed with a resin material.

According to the reactor manufacturing method of the present invention described above, since the bobbin and the insulating paper can be made unnecessary, it is possible to reduce the processes and costs required for manufacturing them. In addition, the coating resin body can be applied with an extremely simple method in which the first intermediate is simply dipped in a resin for molding the coating resin body and dried, for example, by automating these operations. By using a robot hand or the like, the manufacturing efficiency can be further improved. The sealing resin body may be molded by storing the second intermediate body in a mold and potting the resin for the sealing resin body between the mold and the second intermediate body.

As can be understood from the above description, according to the reactor and the manufacturing method thereof of the present invention, it is possible to provide a reactor having excellent heat radiation performance, low vibration and low noise.

It is a longitudinal cross-sectional view of one embodiment of the reactor of the present invention. FIG. 2 is an II-II arrow view of FIG. 1. It is the graph which showed the experimental result which measured the vibration reduction value and the noise reduction value at the time of changing the elasticity modulus of a film resin body. It is the graph which showed the experimental result which measured the vibration reduction value and the noise reduction value at the time of changing the thickness of a film resin body.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Reactor core, 11 ... U-shaped core, 12 ... Gap layer, 2 ... Coil, 3 ... Coating resin body, 4 ... Sealing resin body, 5 ... Heat sink, 10 ... Reactor, G ... Gap between reactor core and coil

Embodiments of the present invention will be described below with reference to the drawings. The illustrated example shows a reactor core composed of two U-type cores and a gap layer, but an I-type core having one or more magnets is interposed between the U-type cores, Of course, it may be a reactor core in which a gap layer is interposed between the I-type core and the U-type core.

FIG. 1 is a longitudinal sectional view of an embodiment of a reactor according to the present invention, and FIG. 2 is a view taken in the direction of arrows II-II in FIG. Reactor 10 is an annular reactor core 1 formed by adhering ends of

U-shaped cores

11 and 11 having two U-shaped magnets in plan view with an adhesive via gap layers 12 and 12;

Coils

2 and 2 formed in a posture in which a gap G is provided on the outer periphery of the core of the reactor core 1, and the outer periphery of the reactor core 1 in which the coil 2 is formed and the coating resin body 3 formed on the outer periphery of the coil 2 The sealing resin body 4 formed on the outer periphery of the coating resin body 3 and the heat sink 5 disposed on the lower end of the coil 2 are roughly configured. Note that a structure in which a cooler or the like for circulating cooling water from a radiator or the like is provided below the heat sink 5 may be provided, and a housing (case) in which the illustrated reactor 10 is made of aluminum or an aluminum alloy thereof. The form accommodated in may be sufficient.

Here, the U-shaped core 11 may be formed of a laminate formed by laminating electromagnetic steel plates, and press-molds a magnetic powder in which a soft magnetic metal powder or a soft magnetic metal oxide powder is coated with a resin binder. It may be formed from a dust core. The soft magnetic metal powder includes iron, iron-silicon alloy, iron-nitrogen alloy, iron-nickel alloy, iron-carbon alloy, iron-boron alloy, iron-cobalt alloy, iron- Phosphorous alloys, iron-nickel-cobalt alloys, iron-aluminum-silicon alloys, and the like can be used. The gap layer 12 is formed of a gap plate or an air gap. When the gap layer 12 is formed from the gap plate, the gap layer 12 may be formed of ceramics such as alumina (Al ₂ O ₃ ) or zirconia (ZrO ₂ ). it can.

Here, the elastic modulus of the coating resin body 3 is set to be lower than that of the sealing resin body 4, and therefore the reactor core 1 and the coil 2 are formed by the coating resin body 3 having relatively excellent deformability. The entire structure is enclosed. In addition, as for the thickness of a film resin body, it is desirable that it is 1 mm or more from the experimental result mentioned later.

Further, an insulating film such as an enamel film is not formed on the outer periphery of the conducting wire constituting the coil 2, and insulation between the two is ensured by interposing a film resin body 3 between the coil 2 and the reactor core 1. Has been.

In order to make the elastic modulus of the coating resin body 3 relatively low in comparison with that of the sealing resin body 4, by changing both raw material resins, both rigidity or deformability at normal temperature is made different. be able to. Here, the film resin body 3 is, for example, a resin that exhibits a rubber shape or a gel shape at room temperature while adjusting the cross-linking density of the resin, and is a soft epoxy resin, urethane resin, silicone resin (modified silicone resin). Including), an olefin resin, and the like. On the other hand, the sealing resin body 4 can be molded from a resin having a relatively high hardness at room temperature, for example, a hard epoxy resin, BMC (resin made of a mixed material such as unsaturated polyester, calcium carbonate, and glass fiber). it can. Further, the molding material of the sealing resin body 4 may contain conductive fillers such as iron, copper, and aluminum in these resin materials. Regarding the fact that the rigidity of the resin changes depending on the hardness, such as gel, rubber, or hard solid, for example, the degree of penetration, which is an index of hardness, is 10 or more, The degree can be defined as rubbery when the degree is less than 10, or Shore A hardness in the Asker C hardness tester is 100 or less, and hard solid when Shore D hardness is 50 or more.

According to the reactor 10 shown in the figure, since the coating resin body 3 having excellent insulating properties is interposed between the coil 2 and the reactor core 1, the resin for molding the sealing resin body 4 contains a conductive filler. And the heat dissipation performance is greatly improved. Further, the reactor resin 1 is interposed between the reactor resin 1 and the relatively hard sealing resin body 4 so that the film resin body 3 having relatively low elasticity (and therefore low rigidity and high deformation performance) is interposed. The film resin body 3 can effectively absorb the vibration at the time of one drive, and the film resin body 3 can reduce the vibration and also can reduce noise due to this. . Due to this vibration reduction, the outermost sealing resin body 4 is not transmitted with a relatively large vibration like a reactor having a conventional structure. Therefore, the hard sealing resin body 4 is cracked by the vibration. Problems such as occurrence are less likely to occur.

Next, a method for manufacturing the illustrated reactor 10 will be outlined.

First, the outer surface of the reactor core 1 and the gap G are formed on the outer periphery of the reactor core 1 including the two

U-shaped cores

11 and 11 and the gap layer 12 interposed between the

U-shaped cores

11 and 11. And forming a first intermediate body in which the coil is disposed in a bobbin-less posture (first step). Here, a predetermined gap G is formed between the coil 2 and the reactor core 1 by interposing a spacer made of the same material as the coating resin body 3 to be molded in a later process in a part between the reactor core 1 and the coil 2. A first intermediate (not shown) in which is formed can be manufactured.

Subsequently, the coating resin body 3 is formed in the outer periphery of the reactor core 1 and the outer periphery of the coil 2 and the gap G between the reactor core 1 and the coil 2 to form a second intermediate body (second step). Here, the resin for forming the coating resin body 3 is accommodated in a container (not shown), and the step of immersing the first intermediate body, taking it out and drying it is performed one or more times (for example, by repeating about three times). Thereby, the 2nd intermediate body not shown which has the membrane | film | coat resin body 3 of predetermined thickness can be manufactured.

Next, a mold is set on the periphery of the second intermediate body on which the coating resin body 3 is formed on the outer periphery, a sealing resin body resin is injected between the mold and the second intermediate body, and the curing is performed. After waiting, the reactor 10 shown in FIGS. 1 and 2 is manufactured (third step). In this step, it is desirable to form the sealing resin body using a material obtained by mixing a conductive filler such as iron with a resin material for the sealing resin body.

As is apparent from this manufacturing method, the insulating coating around the conductor forming the coil 2 is eliminated, and no bobbin or insulating paper is interposed between the coil 2 and the reactor core 1; Since the coating resin body 3 having a thickness of 1 is interposed between the outer periphery and the outer periphery thereof, it is possible to omit both the insulating film forming step on the outer periphery of the conductive wire and the manufacturing process of the bobbin, insulating paper and the like. Therefore, although the coating resin body forming process is required, the man-hours of the entire process can be reduced, and the process can be shortened.

[Experiment and results of measurement of vibration reduction value and noise reduction value when the elastic modulus of the coating resin body and the thickness of the coating resin body were changed]
The inventors changed the elastic modulus of the coating resin body, manufactured a plurality of reactors as shown in FIGS. 1 and 2, and measured the vibration reduction value and noise reduction value of each reactor.

In this experiment, the reactor sealing resin body to be manufactured was molded from BMC having a flexural modulus of 15 GPa. On the other hand, regarding the coating resin bodies having different elastic moduli, as shown in Table 1 below, four reactors having an elastic modulus in the range of 100 kPa to 10 MPa are referred to as Examples 1 to 4, and a reactor having an elastic modulus of less than 100 kPa is a comparative example. Reactors having an elastic modulus of 1 to 3 and an elastic modulus exceeding 10 MPa are shown as Comparative Examples 4 to 6 (however, Comparative Example 6 has no coating resin body), and the vibration reduction value and noise reduction value of each reactor are shown. Here, the resin materials for molding the respective film resin bodies of Examples 1 to 4 and Comparative Examples 1 to 5 are as follows.

Example 1 is a silicone gel (so-called tough gel), Example 2 is a urethane resin, Example 3 is a rubber silicone resin, Example 4 is an olefin resin, Comparative Examples 1 to 3 are silicone gels, and Comparative Example 4 is a polyamide Resin and Comparative Example 5 use PPS resin, respectively, and change their elastic modulus.

In this experiment, a current of 80 A is passed through a coil of a test body whose reactor temperature is adjusted to 60 ° C. to excite vibration. In addition, each reactor is fixed on a test plate placed on the floor via a rubber support, and an acceleration pick is installed on the test plate to measure the vibration when each reactor is driven. A sound collecting microphone was installed at a predetermined distance above the position, and the noise during driving of the reactor was measured. And the vibration reduction value and noise reduction value of each Example and the comparative example with respect to the measured vibration value and noise value of the comparative example 4 corresponding to the reactor of the conventional structure without a film resin body were calculated | required.

The elastic modulus, vibration reduction value, and noise reduction value of each example and comparative example are shown in the following Table 1 and FIG. In the figure, X1 to X4 correspond to Examples 1 to 4, respectively, and Y1 to Y6 correspond to Comparative Examples 1 to 6, respectively.

From Table 1 and FIG. 3, when the elastic modulus is less than 100 kPa (Example 1) or exceeds 10 MPa, it is demonstrated that both the vibration reduction value and the noise reduction value rapidly decrease, and thus the elastic modulus is 100 kPa. It was specified that a reactor having a coating resin body in the range of 10 MPa is desirable. In addition, although the comparative example 1 has a film resin body with the lowest elastic modulus, in the comparative example 1, the film resin body is too soft and easily deformed at the time of molding, so that it is difficult to secure a desired thickness. This is considered to be one factor that the vibration reduction effect is not obtained because there is a portion where the desired thickness cannot be ensured even in the actual specimen.

The inventors further manufactured a plurality of reactors by changing the thickness of the coating resin body, and conducted an experiment for obtaining the vibration reduction value and the noise reduction value of each reactor.

Similar to the above experiment, both the reactor sealing resin bodies to be manufactured were molded from BMC having a flexural modulus of 15 GPa, and the coating resin had an elastic modulus of 3 MPa in the range of 100 kPa to 10 MPa as described above. Therefore, the reactor was manufactured by changing the thickness in the range of 0 to 2 mm. The experimental results are shown in FIG.

In FIG. 4, X5 is an example in which the thickness of the coating resin body is 1 mm, X6 is an example in which the thickness is 1.5 mm, X7 is an example in which the thickness is 2 mm, and Y5 is a comparative example in which the thickness is 0.7 mm. Y6 represents a comparative example having a thickness of 0.2 mm, and Y7 represents a comparative example having a thickness of 0 mm (no coating resin body).

From the result of FIG. 4, it was demonstrated that the thickness of the coating resin body is 1 mm and the inflection point. When the thickness is less than 1 mm, both the vibration reduction value and the noise reduction value rapidly decrease. Therefore, it was demonstrated that it is desirable to apply a film resin body having a thickness of at least 1 mm or more.

[Experiment and results on heat dissipation performance of reactor]
The present inventors further have a reactor as shown in FIGS. 1 and 2 using only BMC as a resin for a sealing resin (thermal conductivity: λ = 1 W / mK), and PPS ( Polyphenylene sulfide (carbon-based) filler containing λ = 10 W / mK) and BMC containing LCP (liquid crystal polymer (carbon-based) filler, λ = 23 W / mK), Each was used to mold a sealing resin body, and both reactors having a film resin body with an elastic modulus of 3 MPa and a thickness of 1 mm were manufactured, and a thermocouple was installed on the upper surface of the coil to measure the temperature.

A reactor having a sealing resin body molded from a material containing PPS in BMC and a material containing LCP in BMC with respect to the measurement temperature of the thermocouple in the reactor having a sealing resin body made only of BMC The temperature reduction value of each reactor having a sealing resin body molded from the above was determined.

As a result, a reactor having a sealing resin body made of a material containing PPS has a temperature drop of 21 ° C., and a reactor having a sealing resin body made of a material containing LCP has a temperature drop of 39 ° C., both It has been demonstrated that a high temperature reduction effect, that is, a high heat dissipation effect can be obtained.

According to the reactor of the present invention described above, a film resin body having a relatively low elastic modulus is interposed between the reactor core and the sealing resin body, thereby obtaining a high vibration reduction effect and a noise reduction effect. Therefore, the generation of cracks in the sealing resin body can be effectively suppressed. Furthermore, since the insulation between the coil and the reactor core is sufficiently secured by the coating resin body, the sealing resin body can be molded from a resin material containing a conductive filler, resulting in heat dissipation performance. Can be significantly improved. This high-quality, high-performance reactor is optimal for application to recent hybrid vehicles, electric vehicles, and the like that require higher performance in the on-board equipment.

The embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration is not limited to this embodiment, and there are design changes and the like without departing from the gist of the present invention. They are also included in the present invention.

Claims

A reactor core comprising at least two U-shaped cores in a plan view and a gap layer interposed between the U-shaped cores;
A coil formed in a bobbin-less posture with a clearance from the peripheral surface of the reactor core on the outer periphery of the reactor core;
A coating resin body formed on the outer periphery of the reactor core and the outer periphery of the coil, and the gap between the reactor core and the coil,
A sealing resin body formed on the outer periphery of the coating resin body,
A reactor in which the coating resin body has a relatively low elastic modulus as compared with the sealing resin body.
The reactor according to claim 1, wherein the elastic modulus of the coating resin body is in a range of 100 kPa to 10 MPa.
The reactor according to claim 1 or 2, wherein the thickness of the coating resin body is 1 mm or more.
The reactor according to any one of claims 1 to 3, wherein the sealing resin body is formed from a mixed material of a resin material and a conductive filler.
At least two planar views each having a U-shaped core and a gap layer interposed between the U-shaped cores, the outer periphery of the reactor core having a clearance from the peripheral surface of the reactor core, and A first step of forming a first intermediate formed by disposing a coil in a bobbin-less posture;
A second step of forming a second intermediate body by forming a coating resin body in the outer periphery of the reactor core and the outer periphery of the coil and in the gap between the reactor core and the coil;
A reactor manufacturing method comprising: a third step of manufacturing a reactor by forming a sealing resin body having an elastic modulus higher than that of the coating resin body on the outer periphery of the coating resin body.
The reactor production according to claim 5, wherein in the first step, the first intermediate body is formed by interposing a spacer made of the same material as that of the coating resin body in a part between the reactor core and the coil. Method.
In the second step, the step of immersing the first intermediate in a container in which a resin for forming a resin film body is accommodated, taking it out and drying it is performed one or more times to thereby remove the second intermediate. The manufacturing method of the reactor of Claim 5 or 6 formed.
The method for manufacturing a reactor according to any one of claims 5 to 7, wherein, in the third step, the sealing resin body is formed of a material in which a conductive filler is mixed with a resin material.
The method for manufacturing a reactor according to any one of claims 5 to 8, wherein an elastic modulus of the coating resin body is in a range of 100 kPa to 10 MPa.
The method for manufacturing a reactor according to any one of claims 5 to 9, wherein the thickness of the coating resin body is 1 mm or more.