JP2021034430A - Reactor unit - Google Patents

Abstract

To provide a structure with good assembly workability for a reactor unit in which a plurality of reactors are lined up at a narrow pitch.SOLUTION: A reactor unit 2 includes a plurality of reactors 10a and 10b with a plurality of legs 14 for fastening on the sides, and a cooling plate 20 in which the plurality of reactors 10a and 10b are fixed in a row. The plurality of legs 14 are arranged so as to surround the main bodies of the reactors 10a and 10b when viewed from the normal direction of the cooling plate 20, and at least two legs 14 protrude on both sides of the main body in the arrangement direction of the plurality of reactors 10a and 10b. The cooling plate 20 is provided with a fixing protrusion 21 that projects toward the leg 14 and fixes the leg 14, and a rib 23 that is located between adjacent reactors 10a and 10b. The height of the rib 23 and the fixing protrusion 21 is higher than the height of the leg 14.SELECTED DRAWING: Figure 6

Description

The technique disclosed herein relates to a reactor unit in which a plurality of reactors are fixed to a cooling plate.

Reactor units in which a plurality of reactors are fixed to a cooling plate are known (for example, Patent Documents 1 and 2). The reactor unit of Patent Document 1 is used for a power converter of an electric vehicle. The power converter is a device that converts the electric power of a power source into the driving power of a traveling motor. Multiple reactors are used in boost converters in power converters. Since the power converter of an electric vehicle handles a large amount of electric power, multiple reactors are connected in parallel to support the large amount of electric power. Since the reactor through which a large current flows has a large amount of heat generation, it is fixed to the cooling plate. The back surface of the cooling plate faces the refrigerant flow path, and a plurality of fins are provided on the back surface.

A plurality of legs for fixing the reactor to the cooling plate are provided on the side surface of the main body of the reactor. To stabilize the reactor, the legs are arranged so as to surround the body of the reactor when viewed from the normal direction of the cooling plate. A through hole is provided in the leg, and a bolt is inserted through the through hole to fix the bolt to the cooling plate. Multiple reactors are arranged side by side in a row. In the reactor unit of Patent Document 1, legs protrude on both sides of the reactor body in the direction in which the reactors are arranged.

JP-A-2017-174884 JP-A-2018-163846

For miniaturization, the distance between adjacent reactors should be narrow. On the other hand, if some legs protrude on both sides of the main body in the direction in which the reactors are arranged, the legs tend to interfere with the legs of the adjacent reactor when the reactor is assembled to the cooling plate, which makes the assembly work difficult. The present specification provides a structure having good assembly workability for a reactor unit in which a plurality of reactors are arranged at a narrow pitch.

The reactor unit disclosed herein includes a plurality of reactors and a cooling plate for fixing the reactors. A plurality of fastening legs are provided on the side surface of each reactor. The plurality of reactors are fixed in a row on one surface of the cooling plate. The plurality of legs are arranged so as to surround the main body of the reactor when viewed from the normal direction of the cooling plate (the normal direction of the surface to which the reactor is attached). At least two legs project from both sides of the reactor body in the direction in which the plurality of reactors are arranged. The cooling plate is provided with a fixing protrusion that projects toward the leg and fixes the leg. Further, the cooling plate is provided with ribs so as to be located between adjacent reactors. The heights of the ribs and the fixing protrusions are both higher than the height of the legs.

With the above configuration, the ribs and fixing protrusions approach the reactor to be attached before the leg of the reactor to be assembled interferes with the leg of the reactor already fixed to the cooling plate. The reactor to be assembled is guided to a position where the legs do not interfere with each other by the ribs and the fixing protrusions. Therefore, interference between the legs is avoided when assembling the reactor.

The tip of the rib should have a tapered shape when viewed from the direction intersecting the direction in which the reactors are arranged. The reactor to be assembled is smoothly guided to the planned position of the cooling plate.

A heat transfer sheet is sandwiched between each reactor and the cooling plate, and a plurality of heat radiation fins may be provided on the back surface of the cooling plate. In that case, the fins may be provided so as to overlap with the heat transfer sheet and not to overlap with the ribs when viewed from the normal direction of the cooling plate. By arranging the heat transfer sheet and the fins so as to overlap each other when viewed from the normal direction, the heat of the reactor is efficiently transferred to the fins.

Details of the techniques disclosed herein and further improvements will be described in the "Modes for Carrying Out the Invention" below.

It is a perspective view of a reactor (without a resin cover). It is a perspective view of a reactor (with a resin cover). It is an exploded perspective view of a reactor unit. It is a perspective view of a reactor unit. It is a top view of the reactor unit. It is a side view of a reactor unit. It is a top view of the cooling plate.

The reactor unit of the embodiment will be described with reference to the drawings. First, the reactor 10 will be described with reference to FIGS. 1 and 2. FIG. 1 is a perspective view of the reactor 10 excluding the resin cover 13, and FIG. 2 is a perspective view of the reactor 10 (with the resin cover). For convenience of explanation, the + Z direction of the coordinate system in the figure is defined as "up", and the -Z direction is defined as "down".

As shown in FIG. 1, the main body of the reactor 10 is composed of a ring-shaped core 11 and two coils 12. The two coils 12 are wound around the core so as to be parallel to each other. The two coils 12 are made of one flat wire, and can be electrically regarded as one coil. In FIG. 1, the lead wire of the coil 12 is not shown.

As shown in FIG. 2, the core 11 and the coil 12 are covered with a resin cover 13. A part of the coil 12 is exposed from the upper surface of the resin cover 13. The lower part of the coil 12 is also exposed from the resin cover 13. Although not visible in the figure, the lower surface of the portion of the core 11 protruding from the coil 12 is also exposed from the resin cover 13. The lead wire of the coil 12 extends outward from the resin cover 13, but the lead wire of the coil 12 is not shown in FIG. 2 as well.

A plurality of legs 14 for fixing the reactor project from the side surface of the resin cover 13. Although one leg is not visible in FIG. 2, the resin cover 13 is provided with three legs 14. Each leg 14 is provided with a through hole through which a bolt is inserted. For convenience of explanation, the resin cover 13 covering the core 11 and the coil 12 will be referred to as the main body 13 of the reactor 10 below. A plurality of legs 14 project from the side surface of the main body 13. The leg 14 is a protrusion protruding from the side surface of the main body 13. The legs 14 are integrally molded with the resin cover 13.

The reactor unit 2 will be described. FIG. 3 shows an exploded perspective view of the reactor unit 2, and FIG. 4 shows a perspective view of the reactor unit 2.

The reactor unit 2 is a device in which three reactors 10 are fixed to the cooling plate 20. In FIGS. 3 and 4, reference numerals are omitted for some parts.

The reactor unit 2 is used in a device that handles a large amount of power, for example, a boost converter that boosts the voltage of a power source to the drive voltage of a traveling motor in an electric vehicle. The three reactors 10 are connected in parallel to distribute a large amount of power. Alternatively, each of the three reactors 10 is used for each of the three boost converters. In FIGS. 3 and 4, the electrical wiring of the reactor is not shown.

The three reactors 10 are fixed to the cooling plate 20 side by side in the example. As described above, in the reactor 10, the lower portion of the coil 12 and the lower surface of the portion of the core 11 protruding from the coil 12 are exposed from the resin cover 13. The heat transfer sheet 25 is sandwiched between the lower surface of the coil 12 and the upper surface of the cooling plate 20. The core pedestal 22 projects from the upper surface of the cooling plate 20. The heat transfer sheet 26 is sandwiched between the lower surface of the core 11 and the core pedestal 22. In FIG. 4, the heat transfer sheets 25 and 26 are hidden by the reactor 10 and cannot be seen.

The core pedestal 22 is a portion protruding from the upper surface of the cooling plate 20, and has a height corresponding to the distance from the lower surface of the coil 12 to the exposed lower surface of the core 11. Therefore, both the heat transfer sheet 25 and the heat transfer sheet 26 are sandwiched between the reactor 10 and the cooling plate 20. The heat of the reactor 10 is transferred to the cooling plate 20 via the heat transfer sheets 25 and 26. The cooling plate 20 constitutes one side wall of the refrigerant flow path. A cooler (not shown) constituting the refrigerant flow path is located below the cooling plate 20. The cooling plate 20 is attached to the cooler and the refrigerant flow path is closed. A plurality of fins are provided on the lower surface of the cooling plate 20, and heat is released from the lower surface of the cooling plate 20 and the fins to the refrigerant. The fins are shown later in FIGS. 6 and 7.

Each reactor 10 is fixed to the cooling plate 20 with bolts 30. Corresponding to the three legs 14 of each reactor 10, the cooling plate 20 is provided with three fixing protrusions 21 for each reactor 10. The fixing protrusion 21 projects from the upper surface of the cooling plate 20 toward the leg 14. A bolt fixing hole is provided on the upper surface of the fixing protrusion 21. The lower surface of the leg 14 of the reactor 10 comes into contact with the upper surface of the fixing protrusion 21. The bolt 30 passes through the through hole of the leg 14 and is fixed to the bolt fixing hole of the fixing protrusion 21.

A rib 23 extending in the Y direction of the coordinate system in the drawing is provided on the upper surface of the cooling plate 20. The three reactors 10 are arranged along the X direction of the coordinate system in the drawing, and the ribs 23 are arranged in both the arrangement direction of the reactor 10 (X direction) and the normal direction of the cooling plate 20 (Z direction). It extends in the direction that intersects with. The rib 23 is located between adjacent reactors 10.

The relationship between the rib 23 provided on the cooling plate 20, the fixing protrusion 21, and the leg 14 provided on the main body 13 (resin cover 13) of the reactor 10 will be described. FIG. 5 shows a plan view of the reactor unit 2, and FIG. 6 shows a side view of the reactor unit 2. In FIGS. 5 and 6, a part of the reactor unit 2 is not shown. Further, in FIGS. 5 and 6, the reactor on the right side is represented by reference numeral 10a, and the reactor on the left side is represented by reference numeral 10b. In FIG. 6, the reactor 10b on the left side is drawn by removing it from the cooling plate 20. Further, when each leg is individually indicated, an alphabetic character is added after the reference numeral 14.

As shown in FIG. 5, each reactor 10 has three legs 14 for fixation. The three legs 14 are arranged so as to surround the main body 13 (resin cover 13) of the reactor 10 when viewed from the Z-axis direction. The Z direction corresponds to the normal direction of the upper surface of the cooling plate 20. By arranging the legs 14 for fixing the reactor 10 so as to surround the main body 13, the reactor 10 can be firmly fixed to the cooling plate 20.

The cooling plate 20 is provided with three fixing protrusions 21 corresponding to the three legs 14. The fixing protrusion 21 is also located so as to surround the reactor 10 when viewed from the Z direction (normal direction of the cooling plate 20).

On the other hand, the left back leg 14a of the right reactor 10a and the right back leg 14b of the left reactor 10b are close to each other. When the reactor unit 2 is miniaturized, the distance between adjacent reactors 10 becomes smaller. As a result, the work of attaching the reactor 10 becomes difficult. In the case of the reactor unit 2, as shown in FIGS. 5 and 6, the two legs 14a and 14c of the reactor 10a (the two legs 14b and 14d of the reactor 10b) are in the X direction (arrangement of a plurality of reactors 10). In the direction), it protrudes on both sides of the main body 13. Therefore, when the reactor 10b is attached to the cooling plate 20, the right rear leg 14b approaches the left rear leg 14a of the right rear reactor 10a that has already been attached. If the leg 14b comes into contact with the leg 14a during the mounting work, the leg may be damaged. Therefore, in the reactor unit 2, by adjusting the heights of the ribs 23 and the fixing protrusions 21, it is possible to prevent the legs from coming into contact with each other when the reactor 10 is assembled.

In the side view of FIG. 6, the height of the leg 14 is indicated by reference numeral H1, the height of the fixed protrusion 21 is indicated by reference numeral H2, and the height of the rib 23 is indicated by reference numeral H3. The width of the rib 23 is indicated by reference numeral W1. FIG. 6 also shows fins 29 provided on the back surface of the cooling plate 20.

The height H3 of the rib 23 and the height H2 of the fixing protrusion 21 are both higher than the height H1 of the leg 14. This height relationship provides the following advantages: When the reactor 10b is brought closer to the cooling plate 20, the main body 13 of the reactor 10b approaches the three fixing protrusions 21 and the ribs 23 before the legs 14b approach the legs 14a. The three fixing protrusions 21 corresponding to the reactor 10b are arranged so as to surround the main body 13 of the reactor 10b. Therefore, the main body 13 of the reactor 10b is guided by the three fixing protrusions 21 and approaches the center of the range surrounded by the three fixing protrusions 21, that is, the planned mounting position. Further, the ribs 23 are arranged so as to separate the adjacent reactors 10a and 10b. With such ribs 23, when the leg 14b of the reactor 10b approaches the leg 14a of the reactor 10a, the reactor 10b does not approach the reactor 10a closer than the planned distance. By setting the height H3 of the rib 23 and the height H2 of the fixing protrusion 21 in this way, the leg 14b of the reactor 10b to be assembled interferes with the leg 14a of the reactor 10a already fixed to the cooling plate 20. Before this, the main body 13 of the reactor 10b to be assembled is guided to a position where the legs do not interfere with each other. Therefore, interference between the legs can be avoided when assembling the reactor 10b.

As shown in FIGS. 3 and 6, the tip of the rib 23 is from the Y direction of the coordinate system in the figure (the direction in which the plurality of reactors 10 are arranged and the direction intersecting the normal direction of the cooling plate 20). It's tapered. The tapered rib 23 also contributes to smoothly guiding the reactor 10b to be attached to the correct position.

FIG. 7 shows a plan view of the cooling plate 20. In FIG. 7, the fins 29 provided on the back surface of the cooling plate 20 are shown by broken lines. Further, in FIG. 7, the heat transfer sheet 25 sandwiched between the coil 12 of the reactor 10 and the cooling plate 20 is shown in gray.

As shown in FIGS. 6 and 7, the fin 29 is sandwiched between the heat transfer sheet 25 (coil 12 and the cooling plate 20) when viewed from the Z direction (normal direction of the cooling plate 20) of the coordinate system in the drawing. It is provided so as to overlap with the heat transfer sheet 25) and not to overlap with the rib 23. In other words, the fin 29 is located directly below the coil 12 and the heat transfer sheet 25. With such a structure, heat is effectively transferred from the coil 12 to the fins 29.

The points to be noted regarding the technique described in the examples will be described. The reactor unit 2 of the embodiment has a structure in which three reactors 10 are arranged in a row on the cooling plate 20. The number of reactors fixed to the cooling plate may be two or more. Further, a plurality of reactors may be arranged in two rows (or more rows). When they are arranged in a plurality of columns, it is sufficient that the structure of the embodiment is realized in any of the columns.

The main body 13 of the reactor 10 is provided with three legs 14. The number of legs is not limited to three. The plurality of legs are provided on the side surface of the main body 13 of the reactor. The plurality of legs surround the main body of the reactor when viewed from the normal direction of the cooling plate, and at least two legs need to project to both sides of the main body in the direction in which the reactors are arranged.

Although specific examples of the present invention 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 specific examples illustrated above. The technical elements described herein or in the drawings exhibit their 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 illustrated in the present specification or drawings can achieve a plurality of purposes at the same time, and achieving one of the purposes itself has technical usefulness.

2: Reactor unit 10, 10a, 10b: Reactor 11: Core 12: Coil 13: Resin cover (main body) 14, 14a-14d: Leg 20: Cooling plate 21: Fixed protrusion 22: Core pedestal 23: Rib 25, 26: Heat transfer sheet 29: Fin 30: Bolt

Claims (3)

Multiple reactors with multiple fastening legs on the sides,
A cooling plate in which the plurality of reactors are fixed in a row, and
Is equipped with
The plurality of legs are arranged so as to surround the main body of the reactor when viewed from the normal direction of the cooling plate, and at least two of the legs are arranged on both sides of the main body in the arrangement direction of the plurality of reactors. Protruding,
The cooling plate is provided with a rib that protrudes toward the leg and fixes the leg, and a rib that is located between the adjacent reactors.
The height of the rib and the fixing protrusion is higher than the height of the leg.
Reactor unit. The reactor unit according to claim 1, wherein the ribs are tapered when viewed from a direction intersecting the alignment direction. A heat transfer sheet sandwiched between each of the reactors and the cooling plate,
A plurality of heat radiation fins provided on the back surface of the cooling plate, and
Is further equipped with
The reactor unit according to claim 1 or 2, wherein the fins are provided so as to overlap the heat transfer sheet and not to overlap the ribs when viewed from the normal direction.

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