JP6922514B2 - Reactor - Google Patents

Description

The techniques disclosed herein relate to reactors.

Electric vehicles, including hybrid vehicles, are equipped with a power conversion device that converts the output power of the battery into alternating current and supplies it to the traction motor. The power converter may include a voltage converter circuit that boosts the voltage of the battery, in addition to an inverter circuit that converts direct current to alternating current. The voltage converter circuit has a plurality of switching elements and reactors. Since a large current flows through the reactor and a large amount of heat is generated, the reactor is cooled by a cooler. Patent Documents 1 to 3 disclose an example of a cooler for cooling a reactor. In the technique disclosed in Patent Document 1, a cooler is arranged so as to surround the three side surfaces of the coil of the reactor, and a resin is filled between the cooler and the coil. In the techniques disclosed in Patent Documents 2 and 3, the coil and the cooler face each other with a gap between them on at least two of the three side surfaces of the coil.

JP-A-2015-170753 JP-A-2015-116040 Japanese Unexamined Patent Publication No. 2013-0388334

However, the techniques of Patent Documents 1 to 3 cannot be said to be sufficient techniques from the viewpoint of improving the cooling efficiency of the cooler. For example, in the technique of Patent Document 1, since resin is filled between the cooler and the coil, it is difficult to bring the cooler and the coil into close contact with each other to reduce the interfacial thermal resistance between them. .. In the techniques of Patent Documents 2 and 3, since a part of the cooler and the coil face each other with a gap in between, it cannot be said that the heat transfer property from the coil to the cooler is efficient. As described above, there is still room for improvement in the technique for improving the cooling efficiency of the cooler that cools the reactor.

The technique disclosed in the present specification has been made to solve the above-mentioned problems, and an object thereof is to improve the cooling efficiency of a cooler for cooling a reactor.

The technique disclosed in the present specification has been made to solve at least a part of the above-mentioned problems, and can be realized in the following forms.

According to a form of technology disclosed herein, a reactor is provided. This reactor includes a coil wound around a core, a first cooler, a second cooler, and a third cooler. The first cooler faces the side surface of the coil via a heat radiating member. The second cooler is arranged at a position facing the first cooler with the coil interposed therebetween, and faces another side surface of the coil via a heat radiating member. The third cooler is connected to the first cooler via the first connecting portion, and is connected to the second cooler via the second connecting portion, and is further connected to the coil via a heat radiating member. It faces the side surface. The first connecting portion and the second connecting portion can be expanded and contracted in the direction in which the first cooler and the second cooler face each other. The first cooler is configured to be displaceable in a direction closer to the third cooler and the coil by deformation of the first connecting portion in the opposite direction. The second cooler is configured to be displaceable in a direction closer to the third cooler and the coil by deformation of the second connecting portion in the opposite direction.

According to this configuration, the first cooler and the second cooler can be displaced in the direction closer to the third cooler and the coil, respectively, so that the first cooler and the second cooler can be brought into close contact with the coil. .. As a result, the interfacial thermal resistance between the first and second coolers and the coil can be reduced, and the cooling efficiency can be improved.

The technique disclosed in the present specification can be realized in various aspects, for example, a converter circuit including a reactor, a power conversion device including the converter circuit, a vehicle equipped with the power conversion device, and a reactor. It can be realized in the form of a cooling device, a reactor cooling method, a reactor manufacturing method, and the like.

It is a perspective view of a reactor. It is a top view of the reactor. It is a figure for demonstrating the structure of the connecting member. It is a figure for demonstrating the cooling method of a coil by a cooling device. It is a figure for demonstrating the reactor of the 2nd Embodiment. It is a figure for demonstrating the 1st connection part of 3rd Embodiment. It is a figure for demonstrating the reactor of 4th Embodiment.

<First Embodiment>
The overall configuration of the reactor 1 of the present embodiment will be described with reference to FIGS. 1 and 2. The XYZ coordinate system is shown in FIGS. 1 and 2, and the configuration of the reactor 1 will be described using the XYZ coordinate system as appropriate. FIG. 1 is a perspective view of the reactor 1. FIG. 2 is a plan view of the reactor 1, and the reactor 1 viewed from the upper side (Z-axis positive direction side) is shown.

The reactor 1 includes two coils 2 (2a, 2b), a bobbin 3, a core 4, a cooling device 5, and a heat radiating member 6. The reactor 1 is solidified with a resin containing magnetic particles (magnetic material mixed resin), and a rectangular parallelepiped-shaped sealing resin 8 is formed on the outside of the reactor 1. To aid understanding, the sealing resin 8 is drawn as a virtual line in FIGS. 1 and 2.

The two coils 2 (2a, 2b) are electrically connected in series and are each wound around a bobbin 3. The windings of the two coils 2 (2a, 2b) have a flat plate shape and are covered with an insulating film over the entire length. The bobbin 3 is made of resin, and two coils 2 (2a, 2b) are wound around it. Flange portions 31 are provided on both sides of the bobbin 3 in the coil axis direction (Z-axis direction), and the flange portions 31 regulate both ends of the coil 2. The end of the winding of the coil 2a is connected to the bus bar 21, and the end of the winding of the coil 2b is connected to the bus bar 22. The core 4 is composed of a U-shaped upper core member 4a and a lower core member 4b, respectively, and has a ring-shaped outer shape as a whole. A part of the core 4 is covered with a bobbin 3, and a coil 2 (2a, 2b) is further wound around the core 4.

The cooling device 5 includes a first cooler 51, a second cooler 52, a third cooler 53, a refrigerant supply port 54, and a refrigerant discharge port 55. In the cooling device 5, three coolers 51 to 53 are U-shaped so as to face the three side surfaces of the coil 2 (2a, 2b) so that the coil 2 (2a, 2b) can be cooled from three directions. Have been placed. In other words, the cooling device 5 is configured to sandwich the coil 2 inside the U-shape formed by the three coolers 51 to 53.

Each of the three coolers 51 to 53 is a cooling tube formed in a flat plate shape, and a flow path through which the refrigerant flows is formed therein. As shown in FIG. 2, the main surfaces (one of the surfaces having the largest area) of the coolers 51 to 53 are connected to the coils 2 (2a, 2b) via the heat radiating members 6 (6a, 6b, 6c, 6d), respectively. Facing. Specifically, the first cooler 51 is arranged on the left side (X-axis negative direction side) of the coil 2 (2a, 2b) and faces the left side surface of the coil 2a via the heat radiating member 6a. The second cooler 52 is arranged on the right side of the coil 2 (on the positive direction side of the X axis), faces the first cooler 51 with the two coils 2 interposed therebetween, and faces the right side surface of the coil 2b via the heat radiating member 6d. Facing. The third cooler 53 is arranged on the rear side (Y-axis negative direction side) of the coil 2 (2a, 2b), faces the rear side surface of the coil 2a via the heat radiating member 6b, and faces the rear side surface of the coil 2b. They face each other via the heat radiating member 6c. The heat radiating member 6 (6a, 6b, 6c, 6d) is a flat plate-shaped member arranged between the coil 2 and the coolers 51 to 53, and has an insulating property.

The coolers 51 to 53 are connected to each other by connecting members 7 (7a, 7b). Specifically, the first cooler 51 is connected to the third cooler 53 by the first connecting member 7a, and the second cooler 52 is connected to the third cooler 53 by the second connecting member 7b. ing. The connecting member 7 has a flow path through which the refrigerant flows, and communicates with the inside of each of the coolers on both sides of the connecting member 7. The cooling device 5 is configured so that the refrigerant flowing through one of the coolers connected to the connecting member 7 can move to the other cooler via the internal flow path of the connecting member 7. Specifically, in the cooling device 5, the refrigerant flowing into the inside of the first cooler 51 from the refrigerant supply port 54 moves to the inside of the third cooler 53 via the inside of the first connecting member 7a. It is configured. Then, the refrigerant flowing through the inside of the third cooler 53 moves to the inside of the second cooler 52 via the inside of the second connecting member 7b, and then is discharged from the refrigerant discharge port 55. ing.

FIG. 3 is a diagram for explaining the configuration of the connecting member 7 (7a, 7b). Here, as an example, the configuration of the first connecting member 7a arranged between the first cooler 51 and the third cooler 53 will be described. The second connecting member 7b (FIG. 2) has the same configuration as the first connecting member 7a, and description thereof will be omitted here. As shown in FIG. 3A, the connecting member 7 (first connecting member 7a) includes a tubular female member 71 and a male member 72, respectively. As shown in FIG. 3B, in the first connecting member 7a, the male member 72 is inserted inside the female member 71, and the axial direction of the connecting member 7 depends on the degree to which the male member 72 is inserted (FIG. 3). It can be expanded and contracted in the vertical direction). As a result, as shown in FIG. 3C, the first connecting member 7a is deformed (reduced) so that the length in the axial direction becomes smaller, so that the first cooler 51 approaches the third cooler 53. Can be displaced in the direction. In FIG. 3B, the axial length of the connecting member 7 is L1, but in FIG. 3C, the axial length of the connecting member 7 is L2, which is shorter than L1. There is. Similarly, the second cooler 52 can be displaced in the direction closer to the third cooler 53 by deforming the second connecting member 7b (see FIG. 2) so that the length in the axial direction becomes smaller. In other words, the cooling device 5 can reduce the U-shaped inner portion formed by the three coolers 51 to 53 by reducing and deforming the two connecting members 7 (7a, 7b).

Hereinafter, as shown in FIG. 3C, in addition to the first connecting member 7a, the peripheral portion connected to the first connecting member 7a of the first cooler 51, and the third cooler 53. The whole including the peripheral portion connected to the first connecting member 7a is also referred to as "first connecting portion JA1". Further, in addition to the second connecting member 7b, a peripheral portion connected to the second connecting member 7b of the second cooler 52 and a peripheral portion connected to the second connecting member 7b of the third cooler 53. The whole including the whole is also called "second connecting portion JA2" (not shown). In the present embodiment, the first cooler 51 can be displaced in the direction approaching the third cooler 53 by the deformation of the first connecting member 7a in the first connecting portion JA1. Further, the second cooler 52 can be displaced in the direction approaching the third cooler 53 by the deformation of the second connecting member 7b in the second connecting portion JA2. The first cooler 51 may be displaced in a direction closer to the third cooler 53 due to deformation of a portion of the first connecting portion JA1 other than the first connecting member 7a. The same applies to the second connecting portion JA2. Hereinafter, the first connecting portion JA1 and the second connecting portion JA2 are collectively referred to simply as "connecting portion JA". As described above, the connecting portion JA includes not only the connecting member 7 but also a part of the cooler connected to the connecting member 7.

FIG. 4 is a diagram for explaining a method of cooling the coil 2 (2a, 2b) by the cooling device 5. As described above, in the cooling device 5, the refrigerant flowing into the first cooler 51 from the refrigerant supply port 54 is discharged from the refrigerant discharge port 55 via the third cooler 53 and the second cooler 52. It is configured. A part of the heat generated from the coil 2a is absorbed by the refrigerant flowing inside the first cooler 51 via the heat radiating member 6a. Further, it is absorbed by the refrigerant flowing inside the third cooler 53 via the heat radiating member 6b. A part of the heat generated from the coil 2b is absorbed by the refrigerant flowing inside the third cooler 53 via the heat radiating member 6c. Further, it is absorbed by the refrigerant flowing inside the second cooler 52 via the heat radiating member 6d.

The coolers 51 to 53 are sealed by the sealing resin 8 in a state of being pressurized so as to be pressed against the coils 2 (2a, 2b). That is, the first cooler 51 is pressurized in the direction approaching the coil 2a (X-axis positive direction), and the second cooler 52 is pressurized in the direction approaching the coil 2b (X-axis negative direction). The cooler 53 is pressurized in the direction (Y-axis positive direction) approaching the two coils 2 (2a, 2b). As described above, the first cooler 51 is configured to be displaceable in the direction approaching the third cooler 53 due to the deformation (reduction) of the first connecting member 7a. Therefore, the first cooler 51 is sealed (fixed) in a state of being displaced in the direction (X-axis positive direction) approaching the third cooler 53 and the coil 2a. Further, as described above, the second cooler 52 is configured to be displaceable in a direction approaching the third cooler 53 by deformation (reduction) of the second connecting member 7b. Therefore, the second cooler 52 is sealed (fixed) in a state of being displaced in the direction (X-axis negative direction) approaching the third cooler 53 and the coil 2b. In other words, the cooling device 5 is sealed (fixed) in a state in which the two connecting members 7 are reduced and deformed, that is, the U-shaped inner portion formed by the three coolers 51 to 53 is reduced. ) Has been done.

Since the first cooler 51 is sealed in a state of being pressed against the heat radiating member 6a so as to be in close contact with the coil 2a, the interfacial thermal resistance between the first cooler 51 and the coil 2a can be reduced. can. The interfacial thermal resistance between the first cooler 51 and the coil 2a includes the interfacial thermal resistance between the first cooler 51 and the heat radiating member 6a and the interfacial thermal resistance between the radiating member 6a and the coil 2a. Is included. Further, since the second cooler 52 is sealed in a state of being pressed against the heat radiating member 6d so as to be in close contact with the coil 2b, the interfacial thermal resistance between the second cooler 52 and the coil 2b is reduced. be able to. The interfacial thermal resistance between the second cooler 52 and the coil 2b includes the interfacial thermal resistance between the second cooler 52 and the heat radiating member 6d and the interfacial thermal resistance between the radiating member 6d and the coil 2b. Is included. Further, since the third cooler 53 is sealed in a state of being pressed against the heat radiating member 6b and the heat radiating member 6c so as to be in close contact with the two coils 2 (2a, 2b), the third coolers 53 and 2 The interfacial thermal resistance between the two coils 2 can be reduced.

<Effect of this embodiment>
According to the reactor 1 of the present embodiment described above, the first cooler 51 and the second cooler 52 can be displaced in the direction closer to the third cooler 53 and the coil 2, respectively, by the connecting member 7. It is configured. Therefore, the first cooler 51 and the second cooler 52 can be sealed (fixed) in a state (displaced state) close to the third cooler 53 and the coil 2. As a result, the first cooler 51 and the second cooler 52 can be brought into close contact with the coil 2, and the interfacial thermal resistance between the first cooler 51 and the second cooler 52 and the coil 2 can be reduced. Can be done. By reducing the interfacial thermal resistance between the cooler and the coil, it is possible to improve the cooling efficiency of the coil by the cooler.

Conventionally, a reactor in which a cooler is arranged so as to surround three side surfaces of a coil and the coil and the cooler are sealed with a resin is known. However, in the conventional technique, since the cooler cannot be displaced to the coil side, the coil and the cooler cannot be sufficiently brought into close contact with each other. If the cooler can be brought into close contact with the coil, the cooling efficiency of the coil by the cooler can be improved. According to the reactor 1 of the present embodiment, since the first cooler 51 and the second cooler 52 are configured to be displaceable in the direction approaching the coil 2, respectively, the first cooler 51 and the second cooler 52 The 52 can be sealed in a state of being displaced so as to be in close contact with the coil 2. This reduces the interfacial thermal resistance between the cooler and the coil and improves the cooling efficiency of the coil by the cooler.

<Second Embodiment>
FIG. 5 is a diagram for explaining the reactor 1a of the second embodiment. In the reactor 1 (FIG. 2) of the first embodiment, the coolers 51 to 53 were pressurized by the sealing resin 8 and these were brought into close contact with the coil 2. However, the cooling device 5 may pressurize the coolers 51 to 53 with a configuration other than the sealing resin 8. For example, the reactor 1a of the second embodiment includes three leaf springs 9 (9a, 9b, 9c) instead of the sealing resin 8. A support member (for example, a side wall of a case accommodating the reactor 1a) (for example, a side wall of a case accommodating the reactor 1a) is provided on the left side of the first leaf spring 9a, the lower side of the second leaf spring 9b, and the right side of the third leaf spring 9c, respectively. Have been placed. The first leaf spring 9a is arranged on the left side (X-axis negative direction side) of the first cooler 51, and presses the first cooler 51 in the right direction (X-axis positive direction). The second leaf spring 9b is arranged on the rear side (Y-axis negative direction side) of the third cooler 53, and presses the third cooler 53 in the forward direction (Y-axis positive direction). The third leaf spring 9c is arranged on the right side (X-axis positive direction side) of the second cooler 52, and presses the second cooler 52 in the left direction (X-axis negative direction).

Even with such a configuration, since the first cooler 51 is fixed in a state of being pressed against the heat radiating member 6a so as to be in close contact with the coil 2a, the first cooler 51 is between the first cooler 51 and the coil 2a. The interfacial thermal resistance can be reduced. Further, since the second cooler 52 is fixed in a state of being pressed against the heat radiating member 6d so as to be in close contact with the coil 2b, the interfacial thermal resistance between the second cooler 52 and the coil 2b is reduced. Can be done. Further, since the third cooler 53 is fixed in a state of being pressed against the heat radiating member 6b and the heat radiating member 6c so as to be in close contact with the two coils 2, it is between the third cooler 53 and the two coils 2. The interfacial thermal resistance of the coil can be reduced. Therefore, it is possible to improve the cooling efficiency of the coil by the cooler as in the first embodiment.

<Third Embodiment>
FIG. 6 is a diagram for explaining the first connecting portion JB1 of the third embodiment. The reactor 1 of the first embodiment is configured to be displaceable so that the first cooler 51 approaches the coil 2 due to deformation (reduction) of the first connecting member 7a of the first connecting portion JA1. However, the first connecting portion JA1 may be configured to be displaceable so that the first cooler 51 approaches the coil 2 due to the deformation of the portion other than the first connecting member 7a. For example, as shown in FIGS. 6A and 6B, the first connecting portion JB1 of the third embodiment has a peripheral portion connected to the first connecting member 7c of the first cooler 51, and a peripheral portion. , Groove GP is formed in each of the peripheral portions connected to the first connecting member 7c of the third cooler 53. The groove portion GP is a portion where the wall thickness is relatively thin in each of the first cooler 51 and the third cooler 53, and has a ring-shaped outer shape so as to surround the connection portion with the first connecting member 7c. Have. On the other hand, in the first connecting member 7c of the third embodiment, the male member 72 and the female member 71 are joined by laser welding or brazing, and cannot be expanded or contracted in the axial direction. As shown in FIG. 6C, when the first cooler 51 is pressurized in the direction closer to the third cooler 53, the groove GPs provided in the first cooler 51 and the third cooler 53 are plastically deformed. Thereby, the first cooler 51 can be displaced in the direction approaching the third cooler 53. In FIG. 6B, the distance between the first cooler 51 and the third cooler 53 sandwiching the connecting member 7 was L3, but in FIG. 6C, the first cooler 51 and the third cooler 53 are the same. The distance between the three coolers 53 is L4, which is shorter than L3.

Even with such a configuration, the first cooler 51 and the coil 2a can be sealed (fixed) in a state of being pressed against the heat radiating member 6a so as to be in close contact with the coil 2a. The interfacial thermal resistance between and can be reduced. The second connecting portion JB2 (not shown) has the same configuration as the first connecting portion JB1 so that the second cooler 52 is sealed in a state of being pressed against the heat radiating member 6d so as to be in close contact with the coil 2b. Since it can be fixed), the interfacial thermal resistance between the second cooler 52 and the coil 2b can be reduced. Note that JB2 (not shown) is a portion including a connecting portion between the second cooler 52 and the third cooler 53 and its surroundings.

<Fourth Embodiment>
FIG. 7 is a diagram for explaining the reactor 1b of the fourth embodiment. In the first embodiment, the sealing resin 8 pressurizes the three coolers 51 to 53, and in the second embodiment, the three leaf springs 9 (9a, 9b, 9c) press the three coolers 51 to 53. Is pressurizing. However, the cooling device 5 may combine a plurality of types of pressurizing means. For example, in the cooling device 5 of the fourth embodiment, the first cooler 51 and the second cooler 52 are sealed in a state of being pressurized by the sealing resin 8, and the third cooler 53 is a leaf spring 9 (9b). ) Is fixed in a pressurized state. The leaf spring 9 (9b) is supported from below by a support member (not shown). Even with such a configuration, the interfacial thermal resistance between the first cooler 51 and the coil 2a and the interfacial thermal resistance between the second cooler 52 and the coil 2b can be reduced, respectively.

<Modified example of this embodiment>
The technique disclosed in the present specification is not limited to the above-described embodiment, and can be implemented in various aspects without departing from the gist thereof, and for example, the following modifications are also possible.

[Modification 1] The connecting member 7 of the first embodiment is configured to be expandable and contractible by inserting the male member 72 into the female member 71. However, the connecting member 7 may be configured to be expandable and contractible in the axial direction by a method other than this. For example, the connecting member 7 may include a stretchable bellows (bellows) portion, and may be configured so that the length in the axial direction changes as the bellows portion expands and contracts.

[Modification 2] The cooling device 5 may be sealed with the sealing resin 8 in a state of being pressurized by the leaf spring 9 for at least one of the coolers 51 to 53.

Although the embodiments have been described in detail above, these are merely examples and do not limit the scope of claims. The techniques described in the claims include various modifications and modifications of the above-described embodiments. In addition, the technical elements described in the present specification or the drawings exhibit technical usefulness alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the techniques described in this specification or drawings achieve a plurality of objectives at the same time, and achieving one of the objectives itself has technical usefulness.

1 ... Reactor 2 ... Coil 3 ... Bobbin 31 ... Flange part 4 ... Core 5 ... Cooling device 6 ... Heat dissipation member 7 ... Connecting member 8 ... Sealing resin 9 ... Leaf spring 51 ... 1st cooler 52 ... 2nd cooler 53 … Third cooler 54… Refrigerant supply port 55… Refrigerant discharge port 71… Female member 72… Male member GP… Groove part JA1, JB1… First connection part JA2, JB2… Second connection part

Claims (1)

It ’s a reactor,
The coil wound around the core and
A first cooler facing the side surface of the coil via a heat radiating member,
A second cooler, which is arranged at a position facing the first cooler with the coil in between, and faces the side surface of the coil via a heat radiating member.
A third that is connected to the first cooler via the first connecting portion and is connected to the second cooler via the second connecting portion and faces the side surface of the coil via the heat radiating member. Equipped with a cooler,
The first connecting portion and the second connecting portion can be expanded and contracted in the direction in which the first cooler and the second cooler face each other.
The first cooler is configured to be displaceable in a direction approaching the third cooler and the coil by deformation of the first connecting portion in the opposite direction.
The reactor is characterized in that the second cooler is configured to be displaceable in a direction approaching the third cooler and the coil by deformation of the second connecting portion in the opposite direction.

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