JP7490346B2 - Coil device - Google Patents

Description

The present invention relates to a coil device.

Some coil devices, such as reactors and transformers, are designed so that they can be mounted directly on the board of an electrical circuit. In this type of coil device, lead wires made of copper-clad steel wire (CP wire) or the like are used for the electrical wiring between the coil device and the board.

JP 2004-79573 A (Japan Patent Publication) discloses a substrate-mounted coil device (common mode choke coil) with lead terminals attached to a bobbin. The ends of the windings are wound around and soldered to the base of the lead terminals. The tips of the lead terminals are inserted into through holes in the printed circuit board and soldered to the printed circuit board. This fixes the coil device to the printed circuit board and electrically connects it.

In the common mode choke coil described in JP 2004-79573 A, the lead terminals are implanted on the bottom surface of the bobbin, and the ends of the windings are wound around the lead terminals on the bottom side of the bobbin. Therefore, when the lead terminals are inserted into the through holes of the printed circuit board to mount the coil device on the printed circuit board, the printed circuit board and the ends of the windings are positioned close to each other, making it impossible to ensure an insulating distance between the printed circuit board and the windings, and there is a risk of electric leakage from the windings to the wiring on the printed circuit board.

The present invention was made in consideration of the above circumstances, and its purpose is to provide a coil device that can ensure an insulation distance between the circuit board and the end of the coil.

The coil device according to one embodiment of the present invention is a coil device that can be mounted on a circuit board, and includes a coil having a winding portion and a lead wire drawn from the winding portion, and a terminal block having an insulating main body portion and a lead wire held by the main body portion. The lead wire also has a bottom side terminal that protrudes from the bottom surface of the main body portion that faces the circuit board and can be connected to the circuit board, and a side side terminal that protrudes from the side surface of the main body portion in a direction different from the protruding direction of the bottom side terminal and is connected to the end of the lead wire.

In one embodiment of the present invention, the side terminal may have a folded portion folded back toward the side, and the end of the lead wire may be gripped by the folded portion.

In one embodiment of the present invention, a gap may be provided between the tip of the folded portion of the lead wire and the side of the main body.

In one embodiment of the present invention, the pull-out wire may be a coated wire having a core wire mainly composed of aluminum, and the coating of the pull-out wire may be stripped off at the end of the pull-out wire. In this case, the coil device further includes a coating member that covers the end of the pull-out wire.

In one embodiment of the present invention, the connection point between the end of the lead wire and the side terminal may be covered with a cover member.

In one embodiment of the present invention, the end of the lead wire and the side terminal at the connection point may be connected by soldering, and the soldered end of the lead wire may be covered by a covering member.

In one embodiment of the present invention, the end of the lead wire may cross the side terminal in a state where it is hooked onto the outer peripheral surface of the side terminal.

In one embodiment of the present invention, the terminal block may have multiple lead wires, and the ends of the lead wires may be connected to the multiple lead wires.

In one embodiment of the present invention, the main body and the lead wire may be integrally molded, and the lead wire may have a curved portion embedded inside the main body.

In addition, in one embodiment of the present invention, the direction in which the bottom terminal protrudes from the bottom surface and the direction in which the side terminal protrudes from the side surface may be perpendicular to each other.

In one embodiment of the present invention, the winding section may be disposed on the opposite side of the main body section to the side terminal of the lead wire in the protruding direction of the side terminal, and the lead wire may be routed from the winding section to the side terminal through the bottom side of the main body section.

In one embodiment of the present invention, a groove parallel to the protruding direction may be provided on the bottom surface of the main body, and the lead wire may be routed through the groove.

In one embodiment of the present invention, the depth of the groove is greater than the outer diameter of the lead wire.

In one embodiment of the present invention, the portion of the lead wire passing through the groove may be located on the bottom side of the side terminal or at the same height as the side terminal in the depth direction of the groove, and the end of the lead wire at the connection point may be located on the opposite side of the side terminal from the bottom side.

In addition, in one embodiment of the present invention, the side terminals may be bent toward the side opposite the bottom side.

In one embodiment of the present invention, the winding section may be disposed on the surface opposite the bottom surface of the main body, and the lead wire drawn from the winding section may be routed from the winding section to the side terminal on the side opposite the bottom surface of the main body.

In one embodiment of the present invention, the end of the lead wire at the connection point may be located on the bottom side relative to the side terminal.

In one embodiment of the present invention, the side terminals may be bent toward the bottom side.

In the configuration of an embodiment of the present invention, the lead wire has a bottom side terminal and a side side terminal that protrude in different directions from the main body of the terminal block, and the bottom side terminal is connected to the circuit board, and the side side terminal is connected to the end of the coil. Therefore, when the coil device is mounted on the circuit board, the side side terminal can be positioned away from the circuit board, and an insulation distance can be secured between the end of the coil connected to the side side terminal and the circuit board.

1 is an external perspective view of a coil device according to a first embodiment of the present invention; 1 is an external perspective view of a coil device according to a first embodiment of the present invention; 1 is an exploded perspective view of a coil device according to a first embodiment of the present invention; 2 is a side view of the coil device according to the first embodiment of the present invention, in the vicinity of a lead wire. FIG. 2 is a side view of the coil device according to the first embodiment of the present invention, in the vicinity of a lead wire. FIG. 6A to 6C are diagrams illustrating another example of how to bend the lead wire according to the first embodiment of the present invention. FIG. 11 is an external perspective view of a coil device according to a second embodiment of the present invention. FIG. 6 is an exploded perspective view of a coil device according to a second embodiment of the present invention. FIG. 11 is a side view of the vicinity of a lead wire of a coil device according to a second embodiment of the present invention. FIG. 11 is a side view of the vicinity of a lead wire of a coil device according to a second embodiment of the present invention.

Below, an embodiment of the present invention will be described with reference to the drawings. In the following description, common or corresponding elements are denoted by the same or similar reference numerals, and duplicate descriptions will be omitted.

First Embodiment
Figures 1 and 2 are external perspective views of a coil device 1 according to a first embodiment of the present invention. Figures 1 and 2 are views of the same coil device 1 seen from different viewpoints. Figure 3 is an exploded perspective view of the coil device 1. Note that a covering member 70, which will be described later, is omitted in Figure 3. The coil device 1 of this embodiment is a board-mounted type reactor that can be directly mounted on a circuit board.

In the following explanation, the direction from the upper right to the lower left in FIG. 1 is defined as the X-axis direction, the direction from the upper left to the lower right as the Y-axis direction, and the direction from the lower to the upper Z-axis direction. For ease of explanation, the positive X-axis direction is referred to as the forward direction, and the negative X-axis direction is referred to as the rearward direction. The Y-axis direction is referred to as the left-right direction. The positive Z-axis direction is referred to as the upward direction, and the negative Z-axis direction is referred to as the downward direction. The X-axis direction is the axial direction of the coil 10, which will be described later. When using the coil device 1, the coil device 1 may be disposed facing in any direction.

The coil device 1 includes a coil 10, a bobbin 20, a core 30, and two terminal blocks 40. The coil device 1 is mounted on a circuit board arranged below the coil device 1 (negative side of the Z axis).

The coil 10 of this embodiment is formed of a coated wire 10A such as an enameled wire, in which the outer surface of the core wire 10A1 is covered with an insulating coating 10A2. For the purpose of reducing weight and cost, wire material mainly composed of aluminum is used for the core wire 10A1. The coil 10 has a winding section 11 formed by winding the coated wire 10A around a bobbin 20, and a lead wire 12 drawn out from the winding section 11. The outer surface of the winding section 11 is covered with an insulating protective member 13. At the end 12A of each lead wire 12, the coating 10A2 on the outer surface is peeled off. The end 12A of each lead wire 12 is connected to a lead wire 50, which will be described later.

The coil 10 is wound around the outer periphery of a cylindrical bobbin 20. The center leg 31A of the core 30, which will be described later, is inserted into the hollow portion 21 of the bobbin 20. The bobbin 20 is made of an insulating material such as phenolic resin, epoxy resin, unsaturated polyester resin, urethane resin, BMC (Bulk Molding Compound), PPS (Polyphenylene Sulfide), or PBT (Polybutylene Terephthalate).

The core 30 is made of a magnetic material having a relatively high magnetic permeability (e.g., a dust core, an amorphous core, a silicon steel plate, a nanocrystal core, a ferrite core, etc.). As shown in FIG. 3, the core 30 of this embodiment is a combination of an E-shaped core 31 and an I-shaped core 32. The middle leg 31A of the core 31 is passed through the hollow portion 21 of the bobbin 20, and the part of the core 31 other than the middle leg 31A and the core 32 are arranged to surround the coil 10. The core 30 is not limited to the configuration of this embodiment shown in FIG. 3. The core 30 may be, for example, a combination of two E-shaped cores. Depending on the type and use of the coil device 1, the coil device 1 may not have a core 30.

Each terminal block 40 (40A, 40B) has a main body 41 (41A, 41B) and a number of lead wires 50 (50A, 50B) held by the main body 41. Each lead wire 50 is molded integrally with the main body 41 by insert molding. The two terminal blocks 40A, 40B are respectively disposed in front and behind the bobbin 20 in the front-to-rear direction.

The main body 41 is made of an insulating material. Examples of the material for the main body 41 include phenolic resin, epoxy resin, unsaturated polyester resin, urethane resin, BMC, PPS, and PBT. In this embodiment, the two main bodies 41A and 41B are molded integrally with the bobbin 20 in order to reduce the number of parts in the coil device 1.

Each lead wire 50 (50A, 50B) has a metal core such as iron wire, steel wire, or copper wire. The outer surface of the core wire is plated with tin or an alloy containing tin so that solder containing tin can adhere easily. Each lead wire 50 is made of, for example, copper-clad steel wire (CP wire).

Figures 4 and 5 show side views of the coil device 1 near the terminal block 40A located at the front (positive X-axis direction). Figure 4 shows the state before the terminal 53A of the lead wire 50A is bent, and Figure 5 shows the state after the terminal 53A has been bent.

Each lead wire 50A of the terminal block 40A has a curved portion 51A embedded in the main body 41A and a pair of terminals (bottom surface side terminal 52A, side surface side terminal 53A) protruding from the main body 41A. The curved portion 51A is bent 90 degrees so that both ends face downward and forward, respectively. The bottom surface side terminal 52A (hereinafter referred to as "terminal 52A") is one end (lower end) of the lead wire 50A protruding downward from the bottom surface 42A of the main body 41A. The bottom surface 42A is the surface facing the circuit board arranged on the lower side (negative Z-axis side) of the main body 41A. The side surface side terminal 53A (hereinafter referred to as "side terminal 53A") is the other end (front end) of the lead wire 50A protruding forward from the side surface 43A on the front (positive X-axis side) of the main body 41A. The protruding direction of terminal 52A is perpendicular to the protruding direction of terminal 53A.

Each lead wire 50B of the terminal block 40B has a curved portion (not shown) embedded in the main body 41B and a pair of terminals 52B, 53B protruding from the main body 41B. The curved portion of the lead wire 50B is bent 90 degrees so that both ends face downward and rearward, respectively. The terminal 52B is one end (lower end) of the lead wire 50B protruding downward from the bottom surface 42B on the lower side (negative Z-axis direction side) of the main body 41B. The terminal 53B is the other end (rear end) of the lead wire 50B protruding rearward from the side surface 43B on the rear side (negative X-axis direction side) of the main body 41B. The protruding direction of the terminal 52B and the protruding direction of the terminal 53B are perpendicular to each other.

In this embodiment, the bottom surface 42A of the main body 41A is parallel to the XY plane, and the side surface 43A is parallel to the YZ plane. The bottom surface 42B of the main body 41B is parallel to the XY plane, and the side surface 43B is parallel to the YZ plane.

Of the pair of terminals 52A, 53A, the terminal 52A on the bottom surface 42A side is inserted into a cutout or through hole provided in a circuit board (not shown) and soldered. This fixes the coil device 1 to the circuit board and connects each lead wire 50A to the wiring on the circuit board. Of the lead wires 50A, the terminal 53A on the side surface 43A side is connected to the end 12A of the lead wire 12.

The multiple lead wires 50A and the multiple lead wires 50B are arranged side by side in the left-right direction (Y-axis direction) with a gap between them. Each main body 41A, 41B has a shape that is long in the left-right direction in order to hold the multiple lead wires 50A, 50B. The bottom surfaces 42A, 42B of each main body 41A, 41B are provided with grooves 44A, 44B that extend in the front-back direction (X-axis direction) between adjacent lead wires 50A, 50B. The grooves 44A, 44B are formed so that the dimension (width) C1 in the Y-axis direction (see FIG. 2) and the dimension (depth) C2 in the Z-axis direction (see FIG. 4) are larger than the outer diameter D of the lead wire 12.

In the front terminal block 40A, each of the lead wires 12 drawn from the winding section 11 is passed through one of the grooves 44A. Next, each of the lead wires 12 passed through the grooves 44A is drawn forward of the main body section 41A. At this time, the part of the lead wire 12 drawn forward from the groove 44A is disposed below the terminal 53A. Note that the part of the lead wire 12 drawn forward from the groove 44A may be disposed at approximately the same height as the terminal 53A. Next, the lead wire 12 is bent upward, and further bent left and right above the terminal 53A. At this time, the lead wire 12 and the terminal 53A cross each other when viewed from a viewpoint parallel to the Z axis. The part of the lead wire 12 from the part intersecting with the terminal 53A to the tip is the end 12A from which the coating 10A2 has been stripped.

After the lead wire 12 is bent and crossed with the terminal 53A, the terminal 53A is folded back to grip the end 12A of the lead wire 12, as shown in FIG. 5. This causes the lead wire 12 to be held in a state where it is gripped by the terminal 53A. Note that the outer surface coating 10A2 of the end 12A of the lead wire 12 has been stripped, so that the terminal 53A grips the end 12A, thereby electrically connecting the lead wire 50A and the lead wire 12 (i.e., the coil 10).

In this embodiment, as shown in Figs. 1 and 2, each lead wire 12 is passed through a groove 44A arranged outside the terminal 53A to be connected in the left-right direction, so that the two lead wires 12 are bent from the outside to the inside above the terminal 53A so that their tips face each other, but the present invention is not limited to this configuration. The lead wires 12 may be arranged so as to be held by the terminal 53A. For example, when each lead wire 12 is passed through a groove 44A near the center in the left-right direction among the multiple grooves 44A and the connecting terminal 53A is arranged outside the groove 44A through which the lead wire 12 is passed, each lead wire 12 is bent from the inside to the outside above the terminal 53A. Even in this case, the lead wire 12 and the terminal 53A cross each other, so that the end 12A of the lead wire 12 can be held by the terminal 53A by folding back the terminal 53A.

With the end 12A of the lead wire 12 held by the terminal 53A, the connection point 60 between the lead wire 12 and the terminal 53A is soldered. When soldering, the connection point 60 is immersed in molten solder with the front side (positive X-axis side) of the coil device 1 facing vertically downward. This allows the gap between the lead wire 12 and the terminal 53A at the connection point 60 to be filled with solder. Note that the connection point 60 may be soldered using a soldering iron instead of being immersed in solder.

After the connection point 60 is soldered, it is covered with a covering member 70. The covering member 70 adheres to the lead wire 12 so as to cover at least the entire end 12A of the lead wire 12. The covering member 70 is applied to the connection point 60 in a liquid state, for example, and then hardens (so-called adhesive). This allows the covering member 70 to adhere to the connection point 60.

The covering member 70 is provided to prevent electrolytic corrosion from occurring at the location where the covering 10A2 of the covered wire 10A is peeled off when a current is passed through the coil 10. It is believed that electrolytic corrosion occurs when electricity is passed through a conductor with moisture attached thereto. For this reason, it is desirable that the material of the covering member 70 is insulating and waterproof. It is also desirable that the material of the covering member 70 is relatively resistant to deterioration due to heat. This prevents cracks from occurring in the covering member 70 due to heat generated when a current is passed through the coil 10, and prevents electrolytic corrosion from occurring due to moisture that has entered the cracks. For example, epoxy resin, silicone resin, urethane resin, etc. can be used for the covering member 70.

In addition, it is desirable that the covering member 70 covers not only the end 12A of the lead wire 12, but also the portion of the terminal 53A that grips the end 12A. This prevents the terminal 53A from coming into contact with an external member and causing a current leak. The terminal 53A is disposed between both ends of the main body 41A in the left-right direction. In addition, when the coil device 1 is mounted on a circuit board, the main body 41A is disposed behind the terminal 53A, and the circuit board is disposed below the terminal 53A. Therefore, it is unlikely that an external member will come into contact with the terminal 53A from the left-right direction, rear, or bottom. Therefore, the covering member 70 does not necessarily have to cover the left-right direction, rear, or bottom side of the terminal 53A.

According to this embodiment, the pair of terminals 52A, 53A of the lead wire 50A protrude in different directions (downward and forward) from the main body 41A. Therefore, the lower terminal 52A can be connected to the circuit board without the forward terminal 53A interfering with the circuit board. This ensures an insulation distance between the end 12A of the lead wire 12 held by the terminal 53A and the circuit board, and prevents leakage from the coil 10 to the circuit board. In this embodiment, since the terminal 53A protrudes forward parallel to the circuit board, the insulation distance between the end 12A of the lead wire 12 held by the terminal 53A and the circuit board can be more reliably ensured, regardless of the length of the terminal 53A in the front-rear direction.

In addition, according to this embodiment, the pair of terminals 52A, 53A of the lead wire 50A each protrude from surfaces (bottom surface 42A, side surface 43A) of the main body 41A that face in different directions. Therefore, when the main body 41A is positioned so that the bottom surface 42A faces the circuit board in order to mount the coil device 1 on the circuit board, the side surface 43A is positioned away from the circuit board. Therefore, the terminal 53A protruding from the side surface 43A can be positioned away from the circuit board. This makes it possible to more reliably ensure the insulation distance between the end 12A of the lead wire 12 held by the terminal 53A and the circuit board.

In addition, in this embodiment, since the terminal 53A of the lead wire 50A protrudes from the front side surface 43A of the main body 41A, it is possible to reduce the dimension of the terminal block 40A in the vertical direction (Z-axis direction), making it easier to make the coil device 1 thinner. Note that the side surface 43A does not have to be parallel to the YZ plane. The side surface 43A only needs to be provided so that the terminal 53A can protrude forward, and may be inclined from the YZ plane in the Y-axis direction or the Z-axis direction.

In addition, in this embodiment, the lead wire 50A has a curved portion 51A embedded inside the main body portion 41A. This configuration prevents the lead wire 50A from falling out of the main body portion 41A. The bending angle of the curved portion 51A is not limited to 90 degrees. The curved portion 51A may be bent so that the terminal 52A protrudes from the bottom surface 42A and the terminal 53A protrudes from the side surface 43A. If the bending angle of the curved portion 51A is less than 90 degrees, the protruding angle and length of the terminal 53A are adjusted so that the terminal 53A does not interfere with the circuit board when the coil device 1 is mounted on the circuit board.

In addition, in this embodiment, the tip 12A of each lead wire 12 extends linearly, spans the terminals 53A of the two lead wires 50A, and is held by the terminals 53A of the two lead wires 50A. This increases the number of lead wires 50A through which current flows, and increases the contact area between the lead wires 12 and the lead wires 50A, making it possible to pass a large current through the coil 10. The number of lead wires 50A holding each lead wire 12 is not limited to two. For example, the lead wire 12 may be held by one lead wire 50A, or by three or more lead wires 50A. Holding the lead wire 12 by multiple lead wires 50A makes it possible to hold the lead wire 12 more stably.

In addition, in this embodiment, a predetermined gap G is provided between the side surface 43A of the main body 41A and the tip of the bent terminal 53A. By providing this gap G, the end 12A of the lead wire 12 is positioned away from the side surface 43A of the main body 41. As a result, when the connection point 60 is immersed in solder, a gap is secured between the side surface 43A of the main body 41A and the liquid surface of the molten solder. Since a resin material is used for the main body 41A, a gap is secured between the main body 41A and the liquid surface of the solder, preventing the main body 41A from melting due to the heat of the solder.

In addition, in this embodiment, the entire connection point 60 can be immersed in solder without contacting the main body 41A with the solder, so the lead wire 50A and the pull-out wire 12 at the connection point 60 can be reliably connected via solder.

In addition, in this embodiment, the end 12A of the lead wire 12 is held at a position away from the side surface 43A of the main body 41. Therefore, even when the end 12A of the lead wire 12 and the terminal 53A are connected by soldering or welding using a soldering iron, the main body 41A is prevented from melting due to heat generated by the soldering iron or welding.

In addition, in this embodiment, the terminal 53A of the lead wire 50A is bent so that the length L of the folded portion 53A1 in the X-axis direction is the same as or longer than the outer diameter D of the lead wire 12. This increases the contact area between the lead wire 12 and the lead wire 50A, and the lead wire 12 is firmly held. Furthermore, this increased contact area reduces the contact resistance between the lead wire 12 and the lead wire 50A, and the current that can be passed through the lead wire 12 (i.e., the coil 10) can be increased.

The gap G between the side surface 43A of the main body 41A and the tip of the terminal 53A is set to be, for example, approximately equal to or greater than the outer diameter D of the lead wire 12 (3.2 mm or greater when the coil 10 is formed from a coated wire 10A with a diameter of 3.2 mm). This allows the terminal 53A of the lead wire 50 to be folded back without interfering with the side surface 43A. Furthermore, it becomes difficult for the solder applied to the connection point 60 to come into contact with the main body 41A through the terminal 53A, which makes it possible to prevent the main body 41A from melting.

In addition, in this embodiment, as shown in Figures 4 and 5, the terminal 53A of the lead wire 50A is bent upward (i.e., toward the opposite side from the bottom surface 42A). This configuration prevents the terminal 53A of the lead wire 50A from interfering with the circuit board when the coil device 1 is mounted on the circuit board with the bottom surface 42 facing the circuit board. This configuration also allows the terminal 53A of the lead wire 50A to protrude forward from a relatively low position of the main body 41A. This reduces the vertical dimension (Z-axis direction) of the main body 41A, and the entire coil device 1 can be made thinner. In addition, the configuration in which the terminal 53A is bent upward ensures an insulation distance between the terminal 53A and the circuit board.

In addition, in this embodiment, the core wire 10A1 of the coated wire 10A that forms the coil 10 is made primarily of aluminum, not copper. Since aluminum is a cheaper material than copper, this embodiment makes it possible to manufacture the coil device 1 at a relatively low cost. Furthermore, since aluminum is lighter than copper, the use of the core wire 10A1 made primarily of aluminum makes it possible to reduce the weight of the coil device 1.

In addition, in the conventional coil device, one terminal is used for both connection to the circuit board and connection to the coil lead wire. Since the shape of the terminal needs to be kept rod-shaped so that it can be inserted into the through hole of the circuit board, in the conventional coil device, it was necessary to wind the coil around the terminal in order to connect the terminal and the coil. In contrast, in this embodiment, the bottom side terminal 52A connected to the circuit board and the side side terminal 53A to which the end 12A of the lead wire 12 is connected are provided separately. Therefore, it is not necessary to wind the lead wire 12 around the terminal 52A of the lead wire 50, and by folding back the terminal 53A, which has a higher rigidity than the lead wire 12, and holding the lead wire 12, it is possible to more reliably connect the terminal 53A and the coil 10 with fewer steps. In addition, the shape of the lead wire 12 at the connection point 60 is simplified, and the work of covering the end 12A of the lead wire 12 from which the coating 10A2 has been stripped with the coating member 70 is facilitated.

In this embodiment, the terminal 53A of the lead wire 50A is provided on the opposite side of the terminal block 40A from the winding section 11. This configuration prevents the winding section 11 from interfering with the work of connecting the lead wire 12 to the terminal 53A, improving the workability when manufacturing the coil device 1. The lead wire 12 is also wired from the winding section 11 to the terminal 53A through the lower side (bottom surface 42A side) of the terminal block 40A. This configuration prevents the lead wire 12 from interfering with the core 30. This configuration also prevents the lead wire 12 from being disposed within the area between the terminal block 40A and the circuit board when the coil device 1 is mounted on the circuit board. Therefore, it is prevented that the cover 10A2 of the lead wire 12 is peeled off due to the lead wire 12 coming into contact with an external member, causing a leakage current.

In addition, in this embodiment, the lead wire 12 is passed through the groove 44A of the terminal block 40A. Therefore, the groove 44A acts as a guide for the lead wire 12, making wiring the lead wire 12 easier. In addition, the lead wire 12 arranged in the groove 44A is protected by the terminal block 40A. Therefore, the lead wire 12 is more reliably prevented from coming into contact with external components.

In this embodiment, an upward force is applied to the lead wire 12 passing through the groove 44A when the lead wire 12 is bent upward in front of the terminal block 40A. This upward force pulls the lead wire 12 upward in the groove 44A, and the lead wire 12 is positioned close to the bottom of the groove 44A. Since the vertical dimension (depth) C2 of the groove 44A is larger than the outer diameter D of the lead wire 12, a gap is provided between the lead wire 12 pulled upward and the bottom surface 42A of the terminal block 40A. When the coil device 1 is mounted on the circuit board in this state, a gap is provided between the lead wire 12 positioned close to the bottom of the groove 44A and the circuit board, and an insulation distance between the lead wire 12 and the circuit board can be ensured.

In addition, in this embodiment, the draw-out wire 12 is hooked onto the outer peripheral surface of the terminal 53A of the lead wire 50A. This allows the draw-out wire 12 to be stably held, facilitating the connection work between the draw-out wire 12 and the lead wire 50A.

In addition, in this embodiment, the draw-out wire 12 is bent left and right while hooked onto the lead wire 50A, so that the end 12A of the draw-out wire 12 and the terminal 53A of the lead wire 50A cross each other. This makes it possible to hold the lead wire 50A with the folded-back terminal 53A.

In the configuration shown in FIG. 5, the terminal 53A of the lead wire 50A is bent into a U-shape, but the configuration of this embodiment is not limited to this. FIG. 6 shows another example of how to bend the terminal 53A of the lead wire 50A. As shown in FIG. 6, the terminal 53A of the lead wire 50A may be bent so as to be wrapped around the draw-out wire 12 (i.e., at an angle of 180° or more). This makes it possible to hold the draw-out wire 12 more stably, and to more reliably connect the draw-out wire 12 and the lead wire 50A so that they are conductively connected.

In addition, in this embodiment, the draw-out wire 12 and the lead wire 50A need only be connected to be conductive, and the connection method is not limited to soldering. For example, the draw-out wire 12 and the lead wire 50A may be welded in a state where the lead wire 50A is gripping the draw-out wire 12.

Second Embodiment
A coil device according to a second embodiment of the present invention will be described below. Fig. 7 is an external perspective view of a coil device 101 according to the second embodiment of the present invention. Fig. 8 is an exploded perspective view of the coil device 101. Note that in Fig. 8, a covering member 170, which will be described later, is omitted from the illustration.

The coil device 101 of the second embodiment includes a coil 110, a bobbin 120, a core 130, and two terminal blocks 140 (140A, 140B). The coil device 101 of the second embodiment differs from the coil device 1 of the first embodiment in the orientation of the coil axis.

The coil 110 is formed from the same coated wire 10A as the coil 10 of the first embodiment. The coil 110 has a winding section 111 arranged with its axis facing up and down (Z-axis direction), and two pull-out wires 112 pulled out from both ends of the winding section 111. The outer circumferential surface of the winding section 111 is covered with a protective member 113 having insulating properties. In this embodiment, the pull-out wires 112 are pulled out from the upper part of the winding section 111.

The bobbin 120 has a cylindrical shape. The coil 110 is wound around the outer circumferential surface of the bobbin 120. The hollow portion 121 of the bobbin 120 penetrates in the vertical direction. A part of the core 130 is inserted into this hollow portion 121.

The core 130 is a combination of an E-shaped core 131 and an I-shaped core 132. The middle leg 131A of the core 131 is passed through the hollow portion 121 of the bobbin 120, and the part of the core 131 other than the middle leg 131A and the core 132 are arranged to surround the coil 110.

Each terminal block 140 (140A, 140B) has a resin body 141 (141A, 141B) and a number of lead wires 150 (150A, 150B). Each lead wire 150 is molded integrally with the body 141 by insert molding. The two terminal blocks 140A, 140B are disposed in front of and behind the bobbin 120 in the front-rear direction (X-axis direction). In this embodiment, the terminal blocks 140A, 140B are molded integrally with the bobbin 120.

Figure 9 shows a side view of the coil device 101 near the terminal block 140A located at the front (positive X-axis direction). Figure 9 shows the state before the terminal 153A of the lead wire 150A is bent, and Figure 10 shows the state after the terminal 153A of the lead wire 150A has been bent.

Each lead wire 150A of the terminal block 140A has a curved portion 151A embedded in the main body 141 and a pair of terminals (bottom surface side terminal 152A, side surface side terminal 153A) protruding from the main body 141A. The curved portion 151A is bent 90 degrees so that both ends face downward and forward, respectively. The bottom surface side terminal 152A (hereinafter referred to as "terminal 152A") is one end (lower end) of the lead wire 150A protruding downward from the bottom surface 142A on the lower side (negative Z-axis direction side) of the main body 141A. The side surface side terminal 153A (hereinafter referred to as "side terminal 153A") is the other end (front end) of the lead wire 150A protruding forward from the side surface 143A on the front (positive X-axis direction side) of the main body 141A.

Each lead wire 112 of the coil 110 is drawn out from the upper part of the winding section 111 and pulled downward. Next, the end 112A of the lead wire 112 is hooked onto the terminal 153A and bent in the left-right direction. As a result, the end 112A of the lead wire 112 and the terminal 153A cross each other in a cross shape. In this state, the terminal 153A is folded back toward the rear so as to grasp the end 112A of the lead wire 112. As a result, the end 112A of the lead wire 112 is held in a state where it is gripped by the terminal 153A.

With the end 112A of the pull-out wire 112 held by the terminal 153A, the connection point 160 between the end 112A and the terminal 153A is soldered. After the connection point 160 is soldered, it is covered with a covering member 170. The covering member 170 is in close contact with the pull-out wire 112 so as to cover at least the entire area where the covering 10A2 of the covered wire 10A has been peeled off (i.e., the end 112A of the pull-out wire 112).

In this embodiment, the direction in which the terminal 153A is bent is different from the direction in which the terminal 53A is bent in the first embodiment. In this embodiment, the end 112A of the lead wire 112 is disposed below the terminal 153A so as to intersect with the terminal 153A. Therefore, in order to grasp the end 112A of the lead wire 112, the terminal 153A is bent downward (i.e., toward the bottom surface 142A) and then folded back.

In this embodiment, the coil 110 is arranged so as to be placed on the upper surface of the terminal block 140. Therefore, by drawing out the lead wire 112 from the upper part of the winding part 111, interference between the lead wire 112 and the terminal block 140 is prevented. Furthermore, if the lead wire 112 is drawn out from the lower part of the winding part 111, the distance from the winding part 111 to the terminal 153A is short, so the length of the lead wire 112 is short, and there is a possibility that the lead wire 112 may become difficult to handle. However, in this embodiment, since the lead wire 112 is drawn out from the upper part of the winding part 111, the length of the lead wire 112 can be secured, and wiring of the lead wire 112 is easy.

The above is an explanation of exemplary embodiments of the present invention. The embodiments of the present invention are not limited to those described above, and various modifications are possible within the scope of the technical concept of the present invention. For example, configurations that appropriately combine embodiments, etc., explicitly shown as examples in the specification, or obvious embodiments, etc., are also included in the embodiments of the present invention.

(Modification)
For example, in the above-described embodiment, the coil device 1, 101 is described as a reactor, but the coil device of the embodiment of the present invention is not limited to a reactor. The coil device may be, for example, a device having a coil such as a transformer or a choke coil.

In addition, in the first and second embodiments described above, both of the two pull-out wires 12, 112 are connected to the lead wires 50A, 150A of the front terminal blocks 40A, 140A, respectively, but the embodiment of the present invention is not limited to this configuration. The choice of which of the front and rear lead wires 50, 150 each pull-out wire 12, 112 is connected to can be changed depending on the coil device 1, 101 and the wiring of the circuit board on which the coil device 1, 101 is mounted, etc.

For example, in the first embodiment, two pull-out wires 12 are pulled out from the front lower end of the winding section 11, but depending on the configuration of the coil 10, one of the pull-out wires 12 may be pulled out from the front lower end of the winding section 11 and the other from the rear lower end of the winding section 11. In this case, the wiring distance of the pull-out wires 12 can be shortened by connecting one of the pull-out wires 12 to the front lead wire 50A and connecting the other pull-out wire 12 to the rear lead wire 50B.

In addition, when the coil device 1, 101 has multiple coils, the number of lead wires increases according to the number of coils. In this case, if all of the lead wires are connected to either the front or rear lead wire 50, 150, there is a possibility that the lead wires may interfere with each other. Therefore, when the coil device 1, 101 has multiple coils, the multiple lead wires can be divided into those that are led to the front and those that are led to the rear, thereby preventing the lead wires from interfering with each other.

In addition, in the above-mentioned embodiment, the coil device 1, 101 has the lead wires 50A, 150A having terminals protruding forward and the lead wires 50B, 150B having terminals protruding rearward, but the embodiment of the present invention is not limited to this configuration. For example, in the above-mentioned first and second embodiments, the lead wires 12, 112 are connected to the front lead wires 50A, 150A, respectively, so the rear lead wires 50B, 150B may not have terminals protruding rearward. Alternatively, the coil device 1, 101 may not have the rear lead wires 50B, 150B. Furthermore, all the lead wires 50A, 150A provided on the front terminal blocks 40A, 140A may not have terminals 53A, 153A protruding forward. Only the lead wires 50A, 150A connected to the pull-out wires 12, 112 have terminals 53A, 153A, and the other lead wires 50A, 150A may only have terminals 52A, 152A connected to the circuit board.

In addition, while the terminal 53A of the lead wire 50A in the first embodiment is bent upward, and the terminal 153A of the lead wire 150A in the second embodiment is bent downward, the embodiment of the present invention is not limited to this configuration. For example, the terminals 53A, 153A may be bent in the left-right direction. Even in this configuration, the lead wires 12, 112 can be gripped by the terminals 53A, 153A.

The coil device 1, 101 may also be provided with lead wires having terminals that protrude in the left-right direction from the main body portion 41, 141.

Claims (16)

A coil device that can be mounted on a circuit board,
A coil having a winding portion and a lead wire drawn out from the winding portion;
A terminal block having an insulating main body and a lead wire that is a CP wire held by the main body;
Equipped with
The lead wire is
a bottom surface side terminal protruding from a bottom surface of the main body portion facing the circuit board and connectable to the circuit board;
a side surface side terminal protruding from a side surface of the main body in a direction different from the protruding direction of the bottom surface side terminal and connected to an end of the lead wire;
having
the side-face terminal has a folded-back portion folded back toward the side face,
the end of the lead wire extends linearly, is bridged across the side terminals of the plurality of lead wires, and is connected to the plurality of lead wires by being gripped by the folded-back portions of the plurality of lead wires;
Coil device. A gap is provided between the tip of the folded portion of the lead wire and the side surface of the main body.
The coil device according to claim 1 . The lead wire is a coated wire having a core wire mainly composed of aluminum,
the coating of the lead wire is stripped at the end of the lead wire;
The wire further includes a covering member that covers the end of the lead wire.
The coil device according to claim 1 or 2. a connection portion between the end of the lead wire and the side terminal is covered with the covering member;
The coil device according to claim 3 . At the connection point, the end of the lead wire and the side terminal are connected by soldering,
the end of the soldered lead wire is covered with the covering member;
The coil device according to claim 4 . the end of the lead wire is hooked onto an outer peripheral surface of the side terminal and crosses the side terminal in a crisscross shape;
The coil device according to any one of claims 1 to 5. The main body and the lead wire are integrally formed,
The lead wire has a curved portion embedded inside the body portion.
The coil device according to any one of claims 1 to 6 . a direction in which the bottom surface side terminals protrude from the bottom surface and a direction in which the side surface side terminals protrude from the side surfaces are perpendicular to each other;
The coil device according to any one of claims 1 to 7 . the winding portion is disposed on an opposite side to the side terminal with respect to the main body portion in a protruding direction in which the side terminal of the lead wire protrudes,
The lead wire is routed from the winding portion to the side terminal through the bottom side of the main body.
The coil device according to any one of claims 1 to 8 . A groove parallel to the protruding direction is provided on the bottom surface of the main body,
The lead wire is routed through the groove.
The coil device according to claim 9 . The depth of the groove is greater than the outer diameter of the lead wire.
The coil device according to claim 10 . a portion of the lead wire passing through the groove is disposed on the bottom surface side with respect to the side surface side terminal or at the same height as the side surface side terminal in a depth direction of the groove,
the end of the lead wire at the portion connected to the side surface terminal is disposed on the opposite side to the bottom surface side with respect to the side surface terminal;
The coil device according to claim 10 or 11 . The side surface terminals are bent toward the opposite side to the bottom surface.
The coil device according to any one of claims 9 to 12 . the winding portion is disposed on a surface of the main body opposite to the bottom surface,
The lead wire drawn from the winding portion is routed from the winding portion to the side terminal on the opposite side to the bottom side of the main body.
The coil device according to any one of claims 1 to 8 . the end of the lead wire at the portion connected to the side surface terminal is disposed on the bottom surface side with respect to the side surface terminal;
The coil arrangement according to claim 14 . The side surface terminals are bent toward the bottom surface.
The coil device according to claim 14 or 15 .

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