JP6957207B2 - Manufacturing method of reactor and reactor - Google Patents

Description

The present invention relates to a reactor and a method for producing a reactor used in an electric circuit, and more particularly to a reactor and a method for producing a reactor having excellent heat dissipation at low cost.

In recent years, the introduction of clean new energy has been progressing in response to growing concerns about global warming countermeasures or nuclear power generation, and in particular, the spread of solar power generation and wind power generation is being promoted worldwide. .. Photovoltaic power generation is rapidly becoming widespread in Japan due to subsidy policies, etc., but in order to make it even more widespread in the future, it is necessary to reduce power generation costs.

As one method of reducing power generation costs, efforts are being made to improve the durability of the power conditioner, but for that purpose, it is essential to improve the durability of the parts used in the power conditioner, and the power conditioner Measures against dust and humidity are taken by sealing the housing. However, heat-generating parts such as reactors are also used inside the power conditioner, and when the temperature inside the housing rises by sealing the housing, the durability of the electronic parts inside the housing is reduced. It becomes contrary to the original purpose.

Therefore, there is a demand for a reactor having excellent heat dissipation that does not raise the temperature inside the power conditioner even if it is arranged in a closed space. Further, since the durability is improved to reduce the cost, a reactor having a low cost and excellent heat dissipation is required.

As a conventional technique for improving the heat dissipation of the reactor, a method of housing the reactor in an aluminum case and filling it with a resin having excellent heat dissipation is used. In Patent Document 1, which is one of such conventional techniques, a partition wall is provided between two coils of the reactor in order to reduce the amount of heat-dissipating resin used and to reduce the distance between the coil and the case. The structure provided with is used.

Japanese Unexamined Patent Publication No. 2006-41353

However, the conventional technique for improving the heat dissipation of the reactor has a problem that the structure of the case is complicated, which leads to an increase in cost, and when a partition wall is provided between the coils, the reactor becomes large.

Therefore, an object of the present invention is to provide a reactor and a method for producing the reactor, which can reduce the production cost while having excellent heat dissipation.

The reactor of the present invention is a reactor having a core, a coil mounted around the core, and a frame for holding the core to which the coil is mounted, and the frame is formed by bending the core. A holding portion for holding and an accommodating portion filled with a resin having heat dissipation are provided, a part of the coil is accommodated in the accommodating portion, and a part of the coil is filled in the accommodating portion. It is characterized in that it is buried in the resin.

The resin is an epoxy resin having a thermal conductivity of 2.0 W / m · K or more, and it is preferable that alumina is added to the resin, and the frame is preferably made of aluminum.

The ratio of the coil embedded in the resin is 10 to 30%.

The coil is further vacuum impregnated with a low viscosity epoxy resin.

The method for manufacturing a reactor of the present invention is a method for manufacturing a reactor having a core, a coil mounted around the core, and a frame for holding the core to which the coil is mounted, and a plate-shaped member is formed. It is bent to form the frame having a holding portion for holding the core and an accommodating portion filled with a heat-dissipating resin, a coil is mounted around the core, and the accommodating portion of the frame is placed above the accommodating portion. Then, a part of the coil mounted on the core is inserted, the accommodating portion is filled with a resin having heat dissipation property, a part of the coil is embedded in the resin, and then the resin is cured. It is characterized by that.

As the resin, it is preferable to use an epoxy resin having a heat transfer conductivity of 2.0 W / m · K or more, and it is preferable to add alumina to the resin, and it is preferable to use an aluminum plate as the plate-shaped member. ..

When the coil is inserted into the housing, 10 to 30% of the coil is placed in the housing.

After the resin is cured, the coil is vacuum impregnated with a low-viscosity epoxy resin.

The reactor of the present invention is a reactor having a core, a coil mounted around the core, and a frame for holding the core to which the coil is mounted, and the frame is formed by bending the core. A holding portion for holding and an accommodating portion filled with a resin having heat dissipation are provided, and a part of the coil is accommodated in the accommodating portion, and a part of the coil is filled in the accommodating portion. By being embedded in the resin, it can be processed based on the conventional frame, and heat can be dissipated with a small amount of resin. Therefore, a reactor having excellent heat dissipation can be realized without increasing the manufacturing cost. be able to.

Alumina is added to the resin, and the frame is made of aluminum, so that the coefficient of thermal expansion of the resin and the frame are brought close to each other to prevent the resin from peeling from the accommodating portion of the frame, and the durability is improved. It can enhance the sex.

Further, the coil is vacuum-impregnated with a low-viscosity epoxy resin, so that the heat dissipation of the entire coil can be improved.

The method for manufacturing a reactor of the present invention is a method for manufacturing a reactor having a core, a coil mounted around the core, and a frame for holding the core to which the coil is mounted, and a plate-shaped member is formed. It is bent to form the frame having a holding portion for holding the core and an accommodating portion filled with a heat-dissipating resin, a coil is mounted around the core, and the accommodating portion of the frame is placed above the accommodating portion. Then, a part of the coil mounted on the core is inserted, the accommodating portion is filled with a resin having heat dissipation property, a part of the coil is embedded in the resin, and then the resin is cured. As a result, it is possible to manufacture a reactor having excellent heat dissipation at low cost.

By adding alumina to the resin and using an aluminum plate as the plate-shaped member, the thermal expansion coefficients of the resin and the frame are brought close to each other, and the resin is prevented from peeling from the accommodating portion of the frame. , A highly durable reactor can be manufactured.

After the resin is cured, the coil is vacuum impregnated with a low-viscosity epoxy resin, thereby realizing a manufacturing method for enhancing the heat dissipation of the entire coil.

It is a perspective view of the reactor of this invention. It is a top view of the reactor of this invention. It is a side view of the reactor of this invention. It is sectional drawing of the reactor of this invention. It is a perspective view of the frame of the reactor of this invention. (A) is a plan view of the frame of the reactor of the present invention, and (b) is a developed view of a plate-shaped frame before processing.

Hereinafter, the reactor 1 of the present invention and the method for producing the reactor 1 will be described in detail with reference to the drawings. 1 is a perspective view of the reactor 1 of the present invention, FIG. 2 is a plan view, FIG. 3 is a side view, and FIG. 4 is a cross-sectional view. First, the reactor 1 of the present invention will be described.

As shown in FIGS. 1 to 3, the reactor 1 of the present invention has a core 2, two coils 3 mounted on the core 2, and a frame 4 for holding the core 2. The core 2 has two legs 21 and two connecting portions 22, and a coil 3 is wound around and mounted on each of the two legs 21 arranged in parallel with each other. Both ends of the leg portion 21 are fixed and connected by the connecting portion 22, respectively. When the coil 3 is attached to the leg portion 21, an insulating paper (not shown) is attached to the surface of the coil 3. The coil 3 is provided with two terminals 6, which are used for electrical connection of the reactor 1. The number of the terminals 6 is not limited to 2, and may be 4.

As shown in FIG. 5, the frame 4 is composed of a bottom surface 41, an accommodating portion 42, two holding portions 43, and four fixing portions 44, and is composed of a single plate-shaped member made of aluminum, iron, or the like. It is formed by bending. The two holding portions 43 are arranged so as to face each other, and the core 2 to which the coil 3 is mounted is sandwiched and held between them. At this time, the holding portions 43 are connected to each other by the fixing member 7. The accommodating portion 42 is a space provided on the bottom surface 41, and as shown in FIG. 4, a space in which a part of the coil 3 is inserted from above and filled with a resin 5 having heat dissipation. .. The fixing portion 44 is used for fixing the reactor 1 to a device or the like by using bolts or the like, and can be provided as needed, and the shape, position, number, and the like are particularly limited. It's not a thing.

As shown in FIGS. 1 and 4, the accommodating portion 42 is filled with a resin 5 in which a part of the coil 3 is inserted from above and has heat dissipation properties, whereby the cross-sectional view of FIG. 4 is taken. As shown in the above, since a part of the coil 3 is buried in the resin 5, the heat of the coil 3 is dissipated to the outside through the resin 5.

As described above, the reactor 1 of the present invention is new like a case by burying not the whole coil 3 but a part of the coil 3 in the resin 5 having heat dissipation by using the accommodating portion 42 of the frame 4. It is possible to secure a space for filling resin based on the frame used conventionally without providing a member, and to achieve the heat dissipation effect of the coil 3 with a small amount of resin, which greatly increases the cost. The reactor 1 having sufficient heat dissipation can be realized without any problem.

The resin 5 may be any resin having heat dissipation, but it is preferable to use an epoxy resin having a thermal conductivity of 2.0 W / m · K or more in order to improve heat dissipation. Further, it is preferable that alumina is added to the resin 5. The frame 4 is formed by processing a plate material such as aluminum or iron, and it is preferable to use aluminum as the material in consideration of the material of the resin 5. When aluminum is used for the frame 4, by adding alumina to the resin 5, the coefficient of thermal expansion of the frame 4 and the coefficient of thermal expansion of the resin 5 filled in the accommodating portion 42 of the frame 4 are increased. Since the resin 5 can be prevented from peeling off from the accommodating portion 42 of the frame 4, the durability of the reactor 1 can be improved.

The coil 3 may be partially embedded in the resin 5 instead of the whole, but the ratio of the coil 3 to be embedded is the amount of resin to be used and the obtained amount based on the height of the coil 3 in FIGS. Considering the heat dissipation effect, it is preferable to bury 10 to 30% of the coil 3 in the resin 5. As a result, both heat dissipation and low cost can be achieved at the same time.

In order to further enhance the heat dissipation of the reactor 1, it is also possible to vacuum impregnate the coil 3 in a state where the resin 5 is partially embedded with a low-viscosity epoxy resin. As a result, the heat dissipation effect of the reactor 1 can be improved by improving the heat dissipation of the coil 3.

Next, the method for producing the reactor of the present invention will be described. First, a method of processing the frame 4 of the reactor 1 will be described. FIG. 5 is a perspective view of the frame 4, FIG. 6 (a) is a plan view of the frame 4 after processing, and FIG. 6 (b) is a plate-shaped member before processing. It is a development view of the frame 4 in the state of.

A single plate of aluminum or iron is prepared, and cutting or punching is performed according to the shape of the frame 4 as shown in FIG. 6 (b). FIG. 6B is a developed view of a single plate-shaped frame 4 in which only cutting or punching is performed, and then bending is performed. In FIG. 6B, the portion described by the dotted line is the portion to be subjected to the valley bending process, and the portion described by the alternate long and short dash line is the portion to be subjected to the mountain bending process. When the bending process is performed according to the bending line, as shown in FIG. 5, a housing portion 42 surrounded on four sides is formed on the bottom surface 41, and two holding portions 43 facing each other are further formed. , The frame 4 is completed.

The coil 3 was wound around the two legs 21 of the core 2 and mounted, and then both ends of the two legs 21 were connected and fixed by the connecting portions 22, so that the coil 3 was mounted on the core 2. Make it a state. At this time, it is also possible to attach the insulating paper to the surface of the leg portion 21 and arrange the insulating paper or the like between the adjacent coils 3. Then, two terminals 6 used for electrical connection of the reactor 1 are attached to the coil 3.

In this way, when the frame 4 and the core 2 to which the coil 3 is mounted are prepared, the core 2 to which the coil 3 is mounted is placed in the accommodating portion 42 of the frame 4 from above. A part of the coil 3 is inserted, the core 2 is arranged between the two holding portions 43 of the frame 4, the core 2 is sandwiched by the holding portion 42, and the core 2 is placed in the frame 4. Hold and fix by. At this time, the core 2 can be firmly fixed by connecting and fixing the two holding portions 43 to each other by the fixing member 7.

After fixing the core 2 to the frame 4, the accommodating portion 42 of the frame 4 is filled with a resin 5 having heat dissipation, and a part of the coil 3 is embedded in the resin 5. Then, when the resin 5 is cured, the reactor 1 is completed.

Alumina can be added to the resin 5 if necessary. By using aluminum as the material of the frame 4, it is possible to bring the thermal expansion coefficients of the resin 5 and the frame 4 close to each other and prevent the resin 5 from peeling from the accommodating portion 42 of the frame 4. be. Further, the ratio of burying the core 3 is preferably 10 to 30% as described above, and can be appropriately adjusted in consideration of heat dissipation and manufacturing cost.

The coil 3 can be vacuum-impregnated with a low-viscosity epoxy resin after being embedded in the resin 5. This makes it possible to further improve the heat dissipation of the coil 3. In consideration of cost, it is conceivable to appropriately select and perform such an additional step.

The reactor manufacturing method of the present invention can reduce the amount of resin as compared with the conventional manufacturing method, and the step of forming the accommodating portion 42 filled with the resin 5 is also from the step of forming the conventional frame. Since it can be carried out without major changes, it is possible to manufacture a reactor having sufficient heat dissipation at a lower cost.

1 Reactor 2 Core 3 Coil 4 Frame 5 Resin 6 Terminal 7 Fixing member 21 Leg 22 Connecting part 41 Bottom surface 42 Accommodating part 43 Holding part 44 Fixing part

Claims (12)

A reactor having a core, a coil mounted around the core, and a frame holding the core to which the coil is mounted.
The frame is provided with two holding portions for holding the core and an accommodating portion filled with a heat-dissipating resin by bending.
The two holding portions are arranged so as to project upward from the accommodating portion and face each other.
A part of the coil is housed in the housing part, a part of the coil is embedded in the resin filled in the housing part, and the core held in the two holding parts is the resin. A reactor characterized by not being buried in. The reactor according to claim 1, wherein the resin is an epoxy resin having a thermal conductivity of 2.0 W / m · K or more. The reactor according to claim 1 or 2, wherein alumina is added to the resin. The reactor according to any one of claims 1 to 3, wherein the ratio of the coil embedded in the resin is 10 to 30%. The reactor according to any one of claims 1 to 4, wherein the frame is made of aluminum. The reactor according to any one of claims 1 to 5, wherein the coil is further vacuum-impregnated with an epoxy resin. The method for producing a reactor according to any one of claims 1 to 6.
The plate-shaped member is bent to form the frame having two holding portions for holding the core and an accommodating portion filled with a resin having heat dissipation.
A coil is mounted around the core,
A part of the coil mounted on the core is inserted into the accommodating portion of the frame from above, and the core is held by the two holding portions.
A method for producing a reactor, which comprises filling the accommodating portion with a resin having heat dissipation property, burying a part of the coil in the resin, and then curing the resin. The method for producing a reactor according to claim 7, wherein an epoxy resin having a thermal conductivity of 2.0 W / m · K or more is used as the resin. The method for producing a reactor according to claim 7 or 8, wherein alumina is added to the resin. The method for manufacturing a reactor according to any one of claims 7 to 9, wherein 10 to 30% of the coil is arranged in the accommodating portion when the coil is inserted into the accommodating portion. The method for manufacturing a reactor according to any one of claims 7 to 10, wherein an aluminum plate is used as the plate-shaped member. The method for producing a reactor according to any one of claims 7 to 11, wherein the coil is vacuum-impregnated with an epoxy resin after the resin is cured.

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