JP7394562B2 - Reactor and its manufacturing method - Google Patents

Description

The present invention relates to a reactor including a coil and a bus bar, and a method for manufacturing the same.

Reactors are used in a variety of applications, including drive systems for hybrid vehicles, electric vehicles, and fuel cell vehicles. For example, as a reactor used in an on-vehicle booster circuit, one is known in which the periphery of an annular core is covered by resin molding or the like, and a coil is attached to the outer periphery of the annular core.

This type of reactor includes a terminal block having a bus bar, which is a plate-shaped conductive member, in order to connect the coil to an external device. A cylindrical metal member such as a nut is provided below the bus bar of the terminal block, and a terminal of an external device is fixed to this metal member with a bolt or the like. The bus bar is connected at one end to the end of the coil and at the other end to a terminal of an external device. In this way, the reactor and external equipment are electrically connected via the bus bar.

Patent No. 6426798

One end of the bus bar and the end of the coil are often connected by welding. In order to avoid welding defects, it is necessary to accurately align the end faces of the welded parts of the busbar and the coil. On the other hand, a terminal block is usually manufactured by arranging a bus bar, a metal member, etc. in a mold, and injecting resin into the mold. That is, the terminal block is molded separately from the molded product around which the coil is wound, and is fixed to this molded product with bolts or the like. Therefore, when fixing the terminal block to the molded product, it is necessary to align the end faces of the welded parts of the coil and bus bar. However, it has been difficult to align the end faces of the coil and the bus bar and fix the terminal block.

Furthermore, if the terminal block is fixed in a state where the end faces of the welded parts of the coil and the bus bar are not aligned, a separate alignment operation is required. In this work, since the coil and bus bar are fixed in an aligned state, the arrangement position of the jig becomes complicated, which may lead to inefficiency of the welding work.

The present invention has been made to solve the above problems, and an object thereof is to provide a reactor that allows easy connection of a coil and a bus bar, and a method for manufacturing the reactor.

The reactor of the present invention includes a core, a first resin member in which the core is coated with resin, a coil attached to the first resin member, a bus bar connected to the coil, and a bus bar disposed below the bus bar. a metal member for fixing wiring of an external device, and a second resin member in which the core covered with the first resin member, the coil, the bus bar, and the metal member are integrally formed with resin. The first resin member has a housing portion for housing the metal member, and the housing portion is provided above the core and on a surface of the first resin member ; It is characterized by

Further, the reactor manufacturing method of the present invention includes: a core, a coil wound around the core, a busbar connected to the coil, a metal member disposed below the busbar and fixing wiring of an external device; A method for manufacturing a reactor, comprising: a first molding step of coating the core with resin and molding a housing portion for housing the metal member; and a step of molding the housing portion formed by the first molding step. a second molding step of integrally molding the accommodated metal member together with the bus bar and the coil; and a connecting step of connecting the bus bar and the coil; , provided above the core and on the surface of the resin .

According to the present invention, it is possible to provide a reactor that allows easy connection of a coil and a bus bar, and a method for manufacturing the reactor.

FIG. 1 is a perspective view showing the overall configuration of a reactor according to an embodiment. FIG. 3 is an exploded perspective view showing a core covered with a first resin member. It is a sectional view of a resin body in a state where a metal member is housed in a housing part. It is a sectional view of a resin body in a state where a metal member according to another embodiment is housed in a housing part.

(First embodiment)
The reactor of this embodiment will be explained with reference to the drawings. FIG. 1 is a perspective view showing the overall configuration of a reactor according to this embodiment. FIG. 2 is a perspective view of the core covered with the first resin member.

(Schematic configuration)
The reactor 100 is an electromagnetic component that converts electrical energy into magnetic energy, stores and releases it, and is used for increasing and decreasing voltage. The reactor 100 of this embodiment is a reactor used, for example, in a drive system of a hybrid vehicle or an electric vehicle.

As shown in FIGS. 1 and 2, the reactor 100 of this embodiment includes a core 1, a first resin member 2, a coil 3, a terminal portion 4, a sensor 5, and a second resin member 6. The core 1 is made of a magnetic material such as a dust core. The core 1 has an annular shape by joining the ends of two substantially U-shaped cores. There are two coils 3, and each coil 3 is wound around the core 1. The two coils 3 are arranged side by side with a gap in between so that the winding axis directions are parallel to each other. The outer periphery of the core 1 is covered with a first resin member 2. The first resin member 2 is interposed between the core 1 and the coil 3 to insulate the core 1 and the coil 3.

The types of resin that make up the first resin member 2 are epoxy resin, an unsaturated polyester resin, urethane resin, BMC (BULK Molding Compound), PPS (POLPHENYLENE SULFIDE), and PBT (PBT). YBUTYLENE TEREPHTHTHTHALATE) It will be done.

The terminal portion 4 includes a bus bar 41 that connects to the end portion 31 of the coil 3, and a metal member 42 that is provided at the bottom of the bus bar 41 and fixes the wiring of an external device. The bus bar 41 and the metal member 42 are in contact with each other. Thereby, by connecting the terminal of the external device to the metal member 42, the coil 3 and the external device are electrically connected via the bus bar 41 and the metal member 42. When power is supplied from an external device, current flows through the coil 3, magnetic flux is generated, and a closed magnetic circuit is formed within the core 1.

Sensor 5 detects the state of reactor 100. In this embodiment, the sensor 5 is a temperature sensor and detects the temperature of the reactor 100. Sensor 5 is arranged between coils 3. The core 1 covered with the first resin member 2 that constitutes the reactor 100, the coil 3, the bus bar 41 and the metal member 42 of the terminal portion 4, and the sensor 5 are integrated by the second resin member 6. It is molded into. The type of resin constituting the second resin member 6 includes the same type as the first resin member 2, and the same resin as the first resin member 2 may be used, or a different resin may be used. may also be used.

(Detailed configuration)
As shown in FIG. 2, the first resin member 2 is divided into two parts and has two resin bodies 21 and 22. The resin bodies 21 and 22 cover the roughly U-shaped core 1, respectively. That is, the resin bodies 21 and 22 have a pair of straight portions 23 and a connecting portion 24 that connects the straight portions, and are approximately U-shaped. The first resin member 2 is formed by joining the generally U-shaped resin bodies 21 and 22 with their ends facing each other. Note that this straight portion 23 is the location where the coil is wound.

An accommodating section 25 in which the metal member 42 is accommodated is provided on the upper surface of the connecting section 24 of the resin bodies 21 and 22. In other words, the housing portion 25 is provided above the core 1 . In this embodiment, the number of accommodating portions 25 is four in total, two for each connecting portion 24 of each resin body 21 and 22, but the number of accommodating portions 25 may be one. For example, the accommodating portion 25 may not be provided on the resin body 22, but only one may be provided on the connecting portion 24 of the resin body 21.

The accommodating portion 25 has a cylindrical shape with an upper opening and a bottom. That is, the accommodating portion 25 has a bottom portion 251 and a side wall 252 extending from the edge of the bottom portion 251, and has an open top surface. The metal member 42 is accommodated through this opening. In this way, by having the accommodating portion 25, the metal member 42 can be positioned simply by inserting the metal member 42 into the accommodating portion 25.

The inner peripheral surface of the accommodating portion 25 has a shape that follows the outer shape of the metal member 42 . That is, the bottom portion 251 and the side wall 252 define an internal space that follows the outer shape of the metal member 42. Therefore, when the metal member 42 is accommodated in the accommodating portion 25, the outer surface of the metal member 42 and the inner peripheral surface of the side wall 252 of the accommodating portion 42 are in contact with each other. This is because the side wall 252 can prevent the metal member 42 from moving due to the injection pressure of the resin when molding with the second resin member 6. Note that the shape in which the inner circumferential surface of the accommodating portion 25 follows the outer shape of the metal member 42 does not necessarily mean that the entire inner circumferential surface of the accommodating portion 25 follows the outer shape of the metal member 42; It would be good if it was followed. For example, only the upper and lower portions of the housing portion 25 may follow the outer shape of the metal member 42, and the metal member 42 and the upper and lower portions of the side wall 252 may be in contact with each other.

FIG. 3 is a cross-sectional view of the resin body 22 with the metal member 42 housed in the housing portion 25. The bottom portion 251 of the accommodating portion 25 is interposed between the core 1 and the metal member 42, as shown in FIG. The bottom portion 251 has a bulge portion 251a. The bulging portion 251a is a portion that bulges out from the surface of the first resin member 2 that covers the top surface of the core 1, that is, a portion that protrudes from the top surface of the bottom portion 251. The upper surface of the bottom portion 251 is a portion indicated by a broken line in FIG. 3, and is located substantially on the same plane as the surface of the resin member 2 covering the upper surface of the core 1. The bulging portion 251a bulges out from the upper surface of the bottom portion 251 in the same direction as the extending direction of the side wall 252. When the metal member 42 is accommodated in the accommodating portion 25, the bulging portion 251a comes into contact with the lower surface of the metal member 42.

The bulging portion 251a is provided within a region surrounded by the side wall 252, but is not in contact with the side wall 252. That is, there is a gap 253 between the periphery of the bulge 251a and the side wall 252. That is, the outer diameter of the bulging portion 251a is smaller than the inner diameter of the bottom portion 251. Further, it is preferable that the upper surface of the bulging portion 251a is flat. In this embodiment, the gap 253 is provided between the bulge 251a and the side wall 252, but the bulge 251a may be in contact with the side wall 252 without providing the gap 253.

The upper end of the side wall 252 is preferably lower than the upper surface of the metal member 42 housed in the housing section 25 and higher than the center of the metal member 42 . The central portion of the metal member 42 refers to a point that is half the length from the top surface to the bottom surface of the metal member 42 when the metal member 42 is accommodated in the housing portion 25 . If the upper end of the side wall 252 is the same as the upper surface of the metal member 42, the metal member 42 will not be able to be held down by the mold, and the metal member 42 and the bus bar 41 will be damaged by the injection pressure during molding, as will be described later. , there is a risk of it being fixed diagonally. On the other hand, if it is lower than the central portion, it becomes difficult to support the metal member 42 by the side walls 252.

The bus bar 41 is, for example, a conductive member such as copper. The bus bar 6 has a plate-like shape. One end 411 of the bus bar 6 has a hole, which is arranged on the upper surface of the metal member 42 and fixed by the second resin member 6. The bus bar 41 extends from one end 411 toward the end 31 of the coil 3, and the other end 412 is joined to the end 31 of the coil 3 by welding. Note that as the metal member 42, a known member such as a general-purpose hexagonal nut can be used.

(Reactor manufacturing method)
A method for manufacturing a reactor according to this embodiment will be described. The reactor manufacturing method of this embodiment includes (1) a first molding process, (2) an assembly process, (3) a second molding process, and (4) a connecting process.

(1) First molding process The first molding process is a process of covering the core 1 with the first resin member 2 and molding the housing part. At this time, it is preferable that the thickness T1 of the bulging part 251a of the accommodating part 25 shown in FIG. 3 be formed to be 1 mm or more and 4 mm or less. The thickness T1 of the bulging portion 251a refers to the distance from the upper surface of the bottom portion 251 to the end surface of the first resin member 2 that contacts the metal member 42 when the metal member 42 is accommodated in the housing portion 25. That is, the thickness T1 of the bottom portion 251 in this embodiment is the distance from the top surface of the bottom portion 251 to the top surface of the bulge portion 251a. If it is thinner than 1 mm, it may be difficult for the resin to flow in, and there is a possibility that the bulged portion 251a may not be formed. On the other hand, if it is thicker than 4 mm, resin sink marks may occur and unevenness may occur on the mounting surface of the metal member 42, and there is a risk that the metal member 42 may be accommodated in the accommodating portion 25 tilted. In other words, by setting the height to 1 mm or more and 4 mm or less, the upper surface of the bulging portion 251a is formed flat, and the metal member 42 can be accommodated in the accommodating portion 25 without being tilted.

(2) Assembly process The assembly process is a process of assembling the constituent members to be fixed in the second molding process and setting them in a mold. The metal member 42 is accommodated in the housing portion 25, the bus bar 41 is placed on top of the metal member 42, and the bus bar 41 and the metal member 42 are pressed down with a mold. When pressed with this mold, the end surface of the other end 412 of the bus bar 41 and the end surface of the end 31 of the coil 3 are made flush.

The lower surface of the metal member 42 is in contact with a first resin member made of resin. Therefore, even if the metal member 42 is pressed down with a mold, the resin deforms before the metal member 42 deforms, so deformation of the metal member 42 can be suppressed.

In particular, in this embodiment, the bottom surface 251 has a bulging portion 251a bulging from the upper surface. By having this bulging portion 251a, the upper end of the side wall 252 can be easily aligned with the upper end of the metal member 42. For example, if the upper end of the metal member 42 and the upper end of the side wall 252 do not match the desired position depending on the manufactured mold, the height of the side wall 252 may be changed or the thickness of the bottom portion 251 may be changed. In order to change the overall thickness of the first resin member 2 covering the upper surface of the mold, it is necessary to make the mold again. In other words, it is necessary to make major modifications to the mold.

On the other hand, by providing the bulging portion 251a, the alignment between the upper end of the metal member 42 and the upper end of the side wall 252 can be adjusted depending on the thickness of the bulging portion 251a. Therefore, since it is only necessary to modify the mold in the portion corresponding to the dimensions of the bulging portion 251a, there is no need for large-scale modification of the mold, and the upper end of the metal member 42 and the upper end of the side wall 252 can be easily aligned. be able to.

The thickness T1 of the bottom portion 251 after the assembly process is thinner than the thickness formed in the first molding process because the bulging portion 251a is pressed and crushed by the metal member 42. That is, after passing through this step, the thickness becomes thinner than the thickness of the bottom portion 251 molded in the first molding step.

(3) Second molding process The second molding process is a process in which resin that will become the second resin member 6 is injected into the mold that has undergone the assembly process, and the members that constitute the reactor 100 are fixed. Through the second molding process, the core 1, coil 3, bus bar 41, metal member 42, and sensor 5 covered with the first resin member 2 are integrally molded, and each member is fixed.

At this time, since the metal member 42 is supported by the side wall 252 and pressed down by the mold, movement of the metal member 42 due to the injection pressure of injecting the resin into the mold is suppressed. Therefore, the bus bar 41 disposed on the upper surface of the metal member 42 is also integrally molded without moving. Therefore, after the assembly process, the end face of the other end 412 of the bus bar 41 and the end face of the end 31 of the coil 3 are integrally molded in a flush state.

(4) Connection process The connection process is a process of connecting the end 31 of the coil 3 and the other end 412 of the bus bar 41 by welding. This welding is performed only on the end face of the end portion 31 of the coil 3 and the end face of the other end portion 412 of the bus bar 41. Therefore, in this connection process, it is necessary to clamp the end surface of the end portion 31 of the coil 3 and the end surface of the other end portion 412 of the bus bar 41 so that they are flush with each other.

In the present embodiment, the molded product that has undergone the second molding process is integrally molded with the end surface of the other end 412 of the bus bar 41 and the end surface of the end of the coil 3 flush with each other, so that the clamping work is easy. can be easily performed, improving the work efficiency of the welding process.

In addition, it is possible to eliminate the process of molding the terminal block and the process of fixing the terminal block, which was required in the past when a terminal block with a bus bar fixed separately is fixed to a molded product with bolts, etc. The number of processes can be reduced.

(effect)
The reactor 100 according to the present embodiment includes a core 1, a first resin member 2 in which the core 1 is coated with resin, a coil 3 attached to the first resin member 2, and a bus bar 41 connected to the coil 3. , a metal member 42 that is placed at the bottom of the bus bar 41 and fixes the wiring of external equipment, the core 1 covered with the first resin member 2, the coil 3, the bus bar 41, and the metal member 42 are integrally formed of resin. A second resin member 6 is provided, and the first resin member 2 has an accommodating portion 25 that accommodates the metal member 42.

Thereby, the metal member 42 can be easily positioned, improving work efficiency. Further, when integrally molded using the second resin member 6, the coil 3 and the bus bar 41 can be positioned. Therefore, the coil 3 and the bus bar 41 can be integrally molded in a state where they are aligned so that the welding surfaces that are connected by welding are flush with each other. Therefore, the clamping work can be easily performed, the other end 412 of the bus bar 41 and the end 31 of the coil 3 can be easily welded, and workability is improved. Furthermore, there is no need to separately mold the terminal block and fix the terminal block, so the number of work steps can be reduced.

The accommodating portion 25 is provided above the core 1 . For example, if the accommodating portion 25 is provided outside the end face of the connecting portion 24 that is perpendicular to the winding axis direction of the coil 3, the length of the reactor in the winding axis direction becomes long, leading to an increase in size. However, in this embodiment, the accommodating portion 25 is provided on the upper surface of the core 1. Thereby, the accommodating portion 25 can be provided while keeping the reactor 100 compact.

The housing portion 25 has a side wall 252 and a bottom portion 251 that define an internal space that follows the outer shape of the metal member 42 . As a result, even if the metal member 42 is pressed down with a mold when integrally molded with the second resin member 6, since the resin is interposed between the metal member 42 and the core 1, the metal member 42 will not be deformed. can be prevented. Further, since the internal space of the housing portion 25 has a shape that follows the outer shape of the metal member 42, the metal member 42 can also be fixed by the side wall 252. Therefore, a large-scale jig for fixing the metal member 42 is not required, which reduces costs, simplifies the arrangement of the jig, and improves workability.

The bottom portion 251 has a bulging portion 251a that bulges in the same direction as the extending direction of the side wall 252, and the bulging portion 251a has a gap between the side wall 252 and the bulging portion 251a and is in contact with the side wall 252. Not yet. Thereby, the bulging portion 251a is easily crushed, and deformation of the metal member 42 can be further suppressed.

Further, in the reactor manufacturing method of the present embodiment, the thickness T1 of the bulging portion 251a of the accommodating portion 25 molded in the first molding step is 1 mm or more and 4 mm or less. As a result, the upper surface of the bulging portion 251a can be formed flat, so that the metal member 42 can be accommodated in the accommodating portion 25 without being tilted. .

(Other embodiments)
Although embodiments according to the present invention have been described in this specification, these embodiments are presented as examples and are not intended to limit the scope of the invention. The embodiments described above can be implemented in various other forms, and various omissions, substitutions, and changes can be made without departing from the scope of the invention. The embodiments and their modifications are included within the scope and gist of the invention as well as within the scope of the invention described in the claims and its equivalents.

In this embodiment, the bottom portion 251 has the bulge portion 251a, but as shown in FIG. It may have substantially the same thickness as the first resin member 2.

In this embodiment, as shown in FIG. 2, the side wall 252 stands up from the entire periphery of the bottom 251. However, if the side wall 252 can support the metal member 42, You don't have to be on the edge. For example, it may be possible to stand up from only the four corner portions of the roughly rectangular bottom portion 251 and provide the side walls with gaps between them without contacting each other.

100 Reactor 1 Core 2 First resin member 21 Resin body 22 Resin body 23 Straight part 24 Connection part 25 Accommodation part 251 Bottom part 251a Swelling part 252 Side wall 253 Gap 3 Coil 31 End part 4 Terminal part 41 Bus bar 411 One end part 412 Other end portion 42 Metal member 5 Sensor 6 Second resin member

Claims (5)

core and
a first resin member in which the core is coated with resin;
a coil attached to the first resin member;
a bus bar connected to the coil;
a metal member disposed at the bottom of the bus bar and fixing wiring of an external device;
a second resin member that integrally covers the core, the coil, the bus bar, and the metal member covered with the first resin member with resin;
Equipped with
The first resin member has a housing portion that houses the metal member,
The accommodation portion is provided above the core and on the surface of the first resin member ;
A reactor featuring The accommodating portion has a side wall and a bottom portion defining an internal space that follows the outer shape of the metal member;
The reactor according to claim 1, characterized by: The bottom portion has a bulge portion that bulges in the same direction as the extending direction of the side wall,
the metal member is provided on the upper surface of the bulge;
The reactor according to claim 2 , characterized in that: A method for manufacturing a reactor comprising a core, a coil wound around the core, a busbar connected to the coil, and a metal member disposed below the busbar to fix wiring of an external device,
a first molding step of coating the core with resin and molding a housing portion for housing the metal member;
a second molding step of integrally molding the metal member accommodated in the housing portion molded in the first molding step together with the bus bar and the coil;
a connecting step of connecting the bus bar and the coil;
Equipped with
The accommodating portion molded in the first molding step is provided above the core and on the surface of the resin ;
A method for manufacturing a reactor characterized by: The accommodating portion formed by the first molding step has a side wall and a bottom portion defining an internal space that follows the outer shape of the metal member,
The bottom portion has a bulge portion that bulges in the same direction as the extending direction of the side wall,
The thickness of the bulge is 1 mm or more and 4 mm or less,
The method for manufacturing a reactor according to claim 4 , characterized in that:

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