Choke coil and manufacturing method thereof

Abstract

To provide a choke coil having a high space factor and high manufacturing efficiency, and a manufacturing method thereof.SOLUTION: A manufacturing method of a choke coil 10 according to the present invention includes a core preparation step of preparing an arcuate first core 30 and second core 40 that are insulated and coated with resin bobbins 31 and 41 and each have two edges, a first core winding step of winding a first winding 50a around the first core to obtain a first core component 3, a second core winding step of winding a second winding 50b around the second core to obtain a second core component 4, and a butt step of butting the end edges of the wound first core component and the second core component to form an annular shape.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a choke coil that is provided in rectifier circuits, noise suppression circuits, waveform shaping circuits, resonance circuits, power factor correction circuits, various switching circuits, and the like in AC devices such as power supply circuits and inverters, and a manufacturing method thereof; more specifically, the present invention relates to a choke coil that has a high space factor and high manufacturing efficiency, and a manufacturing method thereof. [Background technology]

[0002] Choke coils mounted on the circuits of various AC devices have a winding wound around an annular core covered with an electrically insulating bobbin (for example, see Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2012-59754 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, to wind the core, the winding must be repeatedly pulled out through the central window of the annular core, which is a process that is difficult to mechanize. In addition, when using a thin wire, the winding must be repeated several hundred times. In the case of a thick wire, the winding may be repeated a few times, but the wire is hard, making the process difficult.

[0005] An object of the present invention is to provide a choke coil having a high space factor and high manufacturing efficiency, and a method for manufacturing the same. [Means for solving the problem]

[0006] The method for manufacturing a choke coil according to the present invention includes the steps of: a core preparation step of preparing a first core and a second core, each of which is insulated by a resin bobbin and has two end edges and has an arc-shaped first core and a second core; a first core winding step of winding a first winding around the first core to obtain a first core component; a second core winding step of winding a second winding around the second core to obtain a second core component; and a butting process for butting edges of the first core part and the second core part on which the winding is provided against each other to form an annular shape; has.

[0007] The bobbin that insulates the first core and the second core may have a shape having a flange portion on the outer periphery of the end edge.

[0008] The core preparation step may be a step of insulating an annular core with the bobbin and then cutting the annular core to form the first core and the second core.

[0009] The second core winding step can be performed in a state in which an outer circumferential edge of one flange portion of the first core and an outer circumferential edge of one flange portion of the second core are brought close to each other.

[0010] a first A terminal is formed on one end edge of the first core part, and a winding start portion of the first winding in the first core winding process is electrically connected to the first A terminal; a winding end portion of the first winding is continuous with a winding start portion of the second winding, A second B terminal is formed on one end edge of the second core part, and a winding end portion of the second winding in the second core winding process can be electrically connected to the second B terminal.

[0011] The 1A terminal and the starting portion of the first winding in the first core winding process, and the 2B terminal and the ending portion of the second winding in the second core winding process can be electrically connected by welding or soldering.

[0012] The first core winding process and the second core winding process are outward processes of winding the first winding around the first core and winding the second winding around the second core in a state in which a winding end portion of the first winding is continuous with a winding start portion of the second winding, After the outward travel step, a third core winding process for winding a third return winding around the second core; and a fourth core winding process for winding a fourth return winding around the first core in a state in which the winding end portion of the third winding is continuous with the winding start portion of the fourth winding; The return process may include

[0013] a first A terminal is formed on one end edge of the first core part, and a winding start portion of the first winding in the first core winding process and a winding end portion of the fourth winding in the fourth core winding process are electrically connected to the first A terminal; A second B terminal is formed on one end edge of the second core part, and a winding end portion of the second winding in the second core winding process and a winding start portion of the third winding in the third core winding process may be electrically connected to the second B terminal.

[0014] The 1A terminal and the starting portion of the first winding in the first core winding process and the ending portion of the fourth winding in the fourth core winding process, and the 2B terminal and the ending portion of the second winding in the second core winding process and the starting portion of the third winding in the third core winding process can be electrically connected by a welding method or soldering.

[0015] a first A terminal is formed on one end edge of the first core part and a first B terminal is formed on the other end edge, and a winding start portion of the first winding in the first core winding process is electrically connected to the first A terminal and a winding end portion is electrically connected to the first B terminal; A second A terminal is formed on one end edge of the second core part, and a second B terminal is formed on the other end edge, and the winding start portion of the second winding in the second core winding process can be electrically connected to the second A terminal, and the winding end portion can be electrically connected to the second B terminal.

[0016] The winding direction of the first winding around the first core part and the winding direction of the second winding around the second core part may be the same.

[0017] The winding direction of the first winding around the first core part and the winding direction of the second winding around the second core part may be opposite to each other.

[0018] The winding may be a stranded wire.

[0019] The butting step can be performed by inserting an insulating spacer between at least one end edge of the first core and the second core.

[0020] After the step of manufacturing a choke coil by any one of the above manufacturing methods, The method may include a step of coating the obtained choke coil with a resin.

[0021] The choke coil according to the present invention comprises: a first core having an arc shape and two end edges, the first core being insulated and covered with a resin bobbin except for at least the end edges, the bobbin having a flange portion on the outer periphery of the end edges; a second core having an arc shape, the second core having two edges facing the edges of the first core, and the second core being insulated and covered with a resin bobbin except for at least the edges, the second core having a flange on the outer periphery of the edges; a first A terminal and a second B terminal respectively disposed on the flange portion of one of the opposing end edges of the first core and the second core; a winding electrically connected to the 1A terminal of the first core, wound around the first core, wound around the second core across the other end edge of the first core and the other end edge of the second core, and electrically connected to the 2B terminal of the second core; Equipped with.

[0022] The choke coil according to the present invention is a first core part including a first core having two end edges, the first core being arc-shaped with at least the end edges being insulated and covered with a resin bobbin, the bobbin having a flange on the outer periphery of the end edges, a first winding wound around the first core, a first A terminal electrically connected to a winding start portion of the first winding, and a first B terminal electrically connected to a winding end portion of the first winding; a second core part including a second core having two end edges, the second core being arc-shaped with at least the end edges being insulated and covered with a resin bobbin, the bobbin having a flange on the outer periphery of the end edges, a second winding wound around the second core, a second A terminal electrically connected to a winding start portion of the second winding, and a second B terminal electrically connected to a winding end portion of the second winding; Equipped with The end edges of the first core part and the end edges of the second core part are disposed opposite to each other.

[0023] In addition, the choke coil product of the present invention is The periphery of the above-described choke coil is coated with resin. Effect of the Invention

[0024] According to the manufacturing method of the choke coil of the present invention, the first and second windings are wound in advance so as to straddle the insulatingly coated arc-shaped first and second cores, and then the edges of the first and second cores are butted together to obtain a choke coil. Since the first and second cores are arc-shaped, winding the windings is much easier than with an annular core, and the manufacturing of the windings and choke coils can be automated, thereby increasing the manufacturing efficiency of the choke coil as much as possible. In addition, since the space factor of the windings can be increased compared to when the windings are wound around an annular core, the choke coil can be made smaller, lighter, more efficient, and with a smaller DC resistance.

[0025] According to the manufacturing method of the choke coil of the present invention, a first core part having a first winding wound around a first core and a second core part having a second winding wound around a second core are respectively produced, and a choke coil can be obtained by butting the edges of the first core part and the second core part together. Then, by electrically connecting the terminals of the first core and the second core, a one-phase choke coil for use in a PFC circuit or the like can be obtained when the first winding and the second winding are wound in the same direction, and a common mode choke coil can be obtained when the first winding and the second winding are wound in opposite directions.

[0026] In particular, for choke coils used for high-frequency applications that handle frequencies of 10 kHz or more, it is common to use Litz wire to suppress the skin effect, but since Litz wire is twisted, it has a poor winding space factor and is prone to unwinding, making winding difficult. Furthermore, the wire diameter and number of twists must be specially designed and prepared according to the frequency, which makes it unavoidable to both work and increase the cost. However, if the manufacturing method for the choke coil of the present invention is used, the Litz wire is not required due to the use of stranded wires, and since it is not twisted, the winding space factor is high and the number of wires can be set as desired. In addition, by winding the wire in one direction from the beginning to the end of the winding, the stray capacitance can be reduced, and high efficiency can be achieved, especially in high-frequency choke coils, by reducing the size, weight, and DC resistance. These factors allow for price reduction and even greater effects. [Brief description of the drawings]

[0027] [Figure 1] FIG. 1 is a perspective view of a choke coil according to a first embodiment of the present invention. [Diagram 2] FIG. 2 is a perspective view of the annular core before being coated with resin. [Diagram 3] FIG. 3 is a perspective view of the annular core coated with resin, as viewed from the bottom side. [Figure 4] FIG. 4 is a perspective view of a resin-coated annular core cut into a first core and a second core. [Diagram 5]FIG. 5 is a perspective view of the cut first core and second core, which are opened and arranged side by side and have terminals attached. [Figure 6] FIG. 6 is a perspective view showing a state in which windings are wound around the first core and the second core. [Figure 7] 7 is a rear view of FIG. 6 as viewed from the flange side opposite to the terminals. [Figure 8] FIG. 8 is an explanatory diagram showing the winding direction, winding direction, and magnetic flux direction of windings in only one direction (only the forward path) provided on the first core and the second core. [Figure 9] FIG. 9 is an explanatory diagram showing the winding direction, winding direction, and magnetic flux direction of the return windings applied to the first core and the second core, where FIG. 9(a) shows the outward path and FIG. 9(b) shows the return path. [Figure 10] FIG. 10 is a perspective view showing a process of bringing the end edges of the first core part and the second core part into opposition to each other. [Figure 11] FIG. 11 is a perspective view showing a state in which the end edges of the first core part and the second core part face each other. [Figure 12] FIG. 12 is a plan view of the choke coil of the first embodiment. [Figure 13] FIG. 13 is a front view of the choke coil of the first embodiment. [Figure 14] FIG. 14 is a rear view of the choke coil of the first embodiment. [Figure 15] FIG. 15 is a bottom view of the choke coil of the first embodiment. [Figure 16] FIG. 16 is a left side view of the choke coil of the first embodiment. [Figure 17] FIG. 17 is a right side view of the choke coil of the first embodiment. [Figure 18] FIG. 18 is a perspective view of a choke coil product according to the first embodiment in which the obtained choke coil is housed in a casing by being covered with a resin. [Figure 19] FIG. 19 is a perspective view of FIG. 18 as seen from the bottom side. [Figure 20]FIG. 20 is a perspective view of a first core and a second core obtained by cutting the resin-coated annular core of the second embodiment. [Figure 21] FIG. 21 is a perspective view showing a state in which a first winding and a second winding are wound around a first core and a second core, respectively. [Figure 22] FIG. 22 is a perspective view of a first core part in which a 1A terminal and a 1B terminal are attached to a first winding, and a second core part in which a 2A terminal and a 2B terminal are attached to a second winding. [Diagram 23] FIG. 23 is a perspective view showing an assembly process of the choke coil in which the first core part and the second core part are placed on the base. [Figure 24] FIG. 24 is a perspective view of the choke coil of the second embodiment. [Diagram 25] FIG. 25 is a perspective view of a choke coil product in which the choke coil of the second embodiment is housed in a casing by being covered with resin, as viewed obliquely from below. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0028] Hereinafter, a choke coil 10 according to an embodiment of the present invention will be described with reference to the drawings.

[0029] First Embodiment Fig. 1 is an external perspective view of a choke coil 10 according to an embodiment of the present invention. As shown in the figure, the choke coil 10 includes a first core 30 and a second core 40, which are covered with electrically insulating bobbins 31 and 41, and is configured by winding a winding 50 (50a, 50b) around the cores 30 and 40. The bobbins 31 and 41 are formed with flanges 32, 33, 42, and 43, and the winding 50 is electrically connected to terminals 37a and 47b formed on the flanges 32 and 42.

[0030] The choke coil 10 of the first embodiment can be fabricated in the following manner.

[0031] <Annular core 20> As described below, the choke coil 10 of the present invention has an annular core 20 cut and installed inside. As shown in Fig. 2, the annular core 20 is an annular body formed from a magnetic material, and although it is illustrated as having a circular shape in a plan view, it may be an elliptical shape, a track shape, a rectangular shape, or the like. The cross-sectional shape of the annular core 20 is not limited, but is illustrated as being substantially rectangular. Examples of the annular core 20 include a dust core or a ferrite core formed by compacting and sintering magnetic powder.

[0032] <Coated annular core 22> As shown in FIG. 3, the annular core 20 is covered with a bobbin 21 made of an electrically insulating resin to produce a covered annular core 22. The resin covering can be performed by insert molding or the like. The bobbin 21 has protrusions 24, 25 formed at positions facing each other in the radial direction. The protrusions 24, 25 are divided into two in the subsequent cutting process to form the flanges 32, 33, 42, 43 of the first core 30 and the second core 40. In addition, terminal mounting parts 34, 44 (see also FIG. 4) that are the installation positions of the terminals 37a, 47b are formed on both sides of the outer periphery of one of the protrusions 24. Furthermore, positioning pieces 35, 45 can be protruded on the outer periphery between the protrusions 24, 25 as necessary for fixing and positioning the covered annular core 22 in the cutting process, and for positioning during insert molding of the casing 60 described later (FIGS. 11 and 12).

[0033] <Cutting process> The coated annular core 22 shown in Fig. 3 is cut so as to bisect the protrusions 24, 25 as shown in Fig. 4. The cutting can be performed, for example, by using a cutting wheel. Laser cutting, water jet cutting, etc. may also be used. By the cutting process, the coated annular core 22 is cut into an arc-shaped first core 30 and a second core 40 as shown in Fig. 4. The first core 30 has flanges 32, 33 formed by cutting the protrusions 24, 25 on the circumferential surfaces of the edges 30a, 30b of the core material, and the second core 40 has flanges 42, 43 formed by cutting the protrusions 24, 25 on the circumferential surfaces of the edges 40a, 40b of the core material. The first core 30 and the second core 40 each have a terminal attachment portion 34, 44 continuous with one of the flange portions 32, 42, and also have positioning pieces 35, 45 protruding from the outer periphery between the flange portions 32, 33 and the flange portions 42, 43, respectively.

[0034] <Terminal attachment process> 5, a first A terminal 37a and a second B terminal 47b are attached to terminal attachment portions 34, 44 of the cut first core 30 and second core 40, respectively. The terminals 37a, 47b can be composed of winding holding portions 38, 48 that sandwich the winding 50 (50a, 50b) and are electrically connected to the winding 50 (50a, 50b), and electrical contact portions 39, 49 for electrically connecting the choke coil 10 to other electrical circuits, such as a substrate, and electronic components.

[0035] <Winding process> As shown in Fig. 6 and Fig. 7, a winding 50 (50a, 50b) is wound around the first core 30 and the second core 40 to form the first core part 3 and the second core part 4. The winding 50 may be an insulating-coated conductive wire such as an enamel wire or a fusion wire. The winding 50 may be a solid wire, or may be an assembled wire (so-called parallel wire) in which a plurality of solid wires are arranged in parallel.

[0036] In this embodiment, the winding 50 is a continuous first winding 50a and second winding 50b. The winding 50 includes a forward process consisting of a first winding process in which the first winding 50a is wound around the first core 30, and a second winding process in which the second winding 50b is wound around the second core 40. More specifically, in the first winding process, the first winding 50a is wound around the first core 30 from a winding start portion 52 at the 1A terminal 37a arranged at one end of the first core 30 to a winding end portion 53 at the other end of the first core 30, thereby producing the first core component 3. In the second winding process following the first core winding process, the second winding 50b extends to the second core 40 so as to straddle the flanges 33 and 43, and is wound around the second core 40 in the same direction as the first core 30 from the winding start portion 54 of the second core 40 close to the winding end portion 53 of the first core 30 so that the second B terminal 47b becomes the winding end portion 55, thereby producing the second core part 4. The winding pattern of the forward process consisting of the first core winding process and the second core winding process is shown in FIG. 8. In FIG. 8 and FIG. 9 to be described next, the arrow indicating the winding direction indicates the winding direction as seen from the edge 30a side of the first core 30. When the winding 50 (50a, 50b) is wound as shown in FIG. 8, when a current is applied from the first A terminal 37a side, magnetic flux is generated in the first core part 3 and the second core part 4 in the same direction as shown by the arrow direction.

[0037] 9(a), the return process may include a third core winding process in which, after winding the winding 50 (50a, 50b) in the same manner as in FIG. 8, the second B terminal 47b is used as the winding start portion 55 (the winding end portion in the outward process), and the third winding 50c is wound around the second core 40 in the opposite winding direction to the outward winding, and a fourth core winding process in which the winding 50 reaches the first core 30 so as to straddle the flange portions 33, 43, and the fourth winding 50d is wound around the first core 30 in the opposite winding direction to the outward winding, so that the first A terminal 37a is used as the winding end portion 52 (the winding start portion in the outward process). 9, when a current is applied from the 1A terminal 37a side, magnetic flux is generated in the same direction in the forward and return paths in the first core component 3 and the second core component 4, as shown by the arrows in the figure. Note that it is preferable that the winding 50 is wound so that it extends to the terminals 37a, 47b at both winding start parts (winding end parts) 52, 55.

[0038] When winding the winding 50, it is desirable to arrange the flanges 33, 43 without the terminals 37a, 47b close to each other so that the terminals 37a, 47b are located on both sides of the first core 30 and the second core 40, as shown in Fig. 5. In the forward process, the winding 50a is wound from the 1A terminal 37a through the first core winding process, straddling the flanges 33, 43, through the second core winding process, and to the 2B terminal 47b, by winding the second winding 50b. The return process can be selectively performed, and the winding is wound from the 2B terminal 47b as the winding start 54 through the third core winding process by the third winding 50c, straddling the flanges 33, 43, through the fourth winding process by the fourth winding 50d, and to the 1A terminal 37a.

[0039] As shown in Fig. 7, the winding 50 straddles the flanges 33, 43 when moving from the first core part 3 to the second core part 4, or from the second core part 4 to the first core part 3. Since the winding 50 has the same winding direction in the first core part 3 and the second core part 4 as shown in Figs. 8 and 9, the straddling part 51 of the winding 50 straddles the flanges 33, 43 so as to cross obliquely as shown in Fig. 7. At this time, it is preferable that the straddling part 51 straddles the flanges 33, 43 with a slight margin so that it is not pulled and cut when the edges 30a, 40a and edges 30b, 40b of the first core part 3 and the second core part 4 are butted against each other in the subsequent butting process.

[0040] In the winding process, since the first core part 3 and the second core part 4 are in an arc shape, not an annular shape as in the prior art, the winding 50 (50a, 50b) can be wound around the cores 30, 40, and does not need to be passed through a central window of the annular core as in the prior art. This has the advantage that the winding 50 can be wound extremely easily. In addition, since the winding 50 can be wound densely, the proportion of the central window formed when the first core part 3 and the second core part 4 are connected in an annular shape (space factor) can be increased as much as possible.

[0041] <Butting process> By winding the winding 50 in the winding process, the first core part 3 and the second core part 4 are connected by the winding 50 that straddles the flange parts 33, 43 via the straddling part 51, as shown in Fig. 6 and Fig. 7. From this state, as shown by the arrows in Fig. 10, the flange parts 32, 42 of the first core part 3 and the second core part 4 are brought close to each other so that the ends 30a, 40a on which the terminals 37a, 47b are formed face each other. Then, as shown in Fig. 11, the ends 30a, 40a and ends 30b, 40b of the first core part 3 and the second core part 4 are butted against each other, so that the first core part 3 and the second core part 4 have an annular shape. In addition, the core materials of the first core part 3 and the second core part 4 may be butted together so as to be in close contact with each other, or an insulating spacer may be inserted between the edges 30a, 40a and / or the edges 30b, 40b to form a gap.

[0042] <Winding-terminal connection process> After the first core part 3 and the second core part 4 are butted together in an annular shape, the insulating coating of the winding 50 is removed from the winding start parts 52, 54 and winding end parts 53, 55 which are to be connected to the terminals 37a, 47b, and the winding holding parts 38, 48 of the terminals 37a, 47b are bent as shown in Fig. 1 to be electrically connected to the terminals 37a, 47b. The removal of the insulating coating of the winding 50 and the electrical connection can be performed by various welding techniques such as resistance welding such as heat crimping or fusing, TIG welding, and plasma welding, or by soldering.

[0043] As a result of the above, it is possible to obtain a choke coil 10 in which the first core component 3 and the second core component 4 formed in an annular shape are wound with a winding 50 running from the 1A terminal 37a to the 2B terminal 47b as a forward path, or a one-phase choke coil 10 for use in normal mode in which a winding 50 is further wound with a return path from the 2B terminal 47b to the 1A terminal 37a.

[0044] The obtained choke coil 10 includes a first core part 3 and a second core part 4 in which a winding 50 is densely wound around a first core 30 and a second core 40, and the space factor of the winding 50 can be increased to 65% to 70% or more. By improving the space factor of the choke coil 10, the inductance can be increased, and the choke coil 10 itself can be made smaller, lighter, more efficient, and have a smaller DC resistance. In particular, the space factor of the winding 50 can be increased by using stranded wire instead of a Litz wire in addition to a single wire.

[0045] In addition, when winding 50 is wound in one direction from the start to the end, it is possible to wind without turning back, which makes it possible to suppress unnecessary stray capacitance during high frequency operation. Furthermore, it can fully withstand a high voltage of over 400V applied between the start and end of the winding, such as a choke coil used in a PFC circuit, which will be described later.

[0046] Furthermore, the windings 50a, 50b wound around the first core 30 and the second core 40 are electrically insulated by the flanges 32, 33, 42, 43, so that electrical contact or short circuit therebetween can be prevented.

[0047] <Resin coating process> In the above-mentioned choke coil 10, because the first core part 3 and the second core part 4 are not fixed relative to each other, a gap occurs at the butt joint of the cores 30, 40, causing an opening. Therefore, as shown in Figs. 18 and 19, the choke coil 10 can be resin-coated by insert molding, resin casting (potting), or the like, and placed inside a casing 60 to produce a choke coil product 12. By housing the choke coil 10 inside the casing 60, it is possible to improve the heat dissipation characteristics and achieve uniform heat distribution. Furthermore, by flattening the top surface of the casing 60 as shown in Fig. 18 and increasing the area that comes into contact with a heat sink or the like, it is possible to further improve the heat dissipation characteristics.

[0048] 1 and other figures, the choke coil 10 has positioning pieces 35, 45 protruding from its circumferential surface, so that when the choke coil 10 is housed in a mold, the positioning pieces 35, 45 can be placed against the inner surface of the mold to position and fix the choke coil 10. Then, insert molding can be performed so that the electrical contacts 39, 49 of the terminals 37a, 47b protrude from the bottom surface of the casing 60. By providing a space between the first core part 3 and the second core part 4, the edges 30a, 40a, and / or the edges 30b, 40b when the choke coil 10 is placed in the mold, a gap can be formed between the edges when the resin coating is performed.

[0049] The illustrated choke coil product 12 has a QR code (registered trademark) or a data matrix 61 printed on a casing 60, and describes the product characteristics of the choke coil 10. In addition, reinforcing dummy pins 62, 62 are integrally formed on the underside of the casing 60, in addition to the electrical contact portions 39, 49.

[0050] The choke coil product 12 having the above configuration is mounted on a substrate or the like and can be used as a choke coil for noise prevention circuits, waveform shaping circuits, resonance circuits, various switching circuits, etc. in AC devices such as power supply circuits and inverters. The choke coil product 12 of the present invention can be suitably used as a choke coil used to counter high-frequency distortion currents in circuits equipped with a power factor correction circuit in switching power supplies and the like used as high-frequency choke coil products exceeding 10 kHz, and can also be used as an impedance matching, high-frequency smoothing choke coil.

[0051] In the choke coil 10 and choke coil product 12 of the present invention, the coated annular core 22 is cut into the arc-shaped first core 30 and second core 40, so that the winding 50 can be wound extremely easily. The winding 50 can be wound automatically using a flyer-type winding machine or the like. Therefore, the winding 50 can be wound precisely, and mechanical winding has the advantage of allowing the number of turns (turns) to be accurately controlled. Furthermore, when winding the winding 50 using a flyer-type winding machine, if multiple windings 50 are set on the nozzle of the winding machine and wound, the windings 50 can be twisted and wound into a Litz wire.

[0052] In the above embodiment, the coated annular core 22 is completely cut into two pieces in the cutting process to obtain the first core 30 and the second core 40. However, as a modified example, the tip of the protrusion 25 may be left uncut, and the first core 30 and the second core 40 may be opened with the flange portions 33, 43 connected in a hinge-like shape, and the winding 50 may be wound therearound, and the hinge portion may be folded to butt the first core 30 and the second core 40 together.

[0053] Furthermore, the number of windings 50 (number of cores) wound around the first core 30 and the second core 40 can be set appropriately according to the frequency. For example, when winding multiple windings 50, the multiple windings 50 can be wound in parallel by repeating the forward process, or the forward process and the return process, multiple times.

[0054] <Second embodiment> In the first embodiment, the winding 50 (50a, 50b) spanning from the first core component 3 to the second core component 4 is wound around the first core 30 and the second core 40. In contrast, in the second embodiment, the first core component 3 having the winding 50a wound around the first core 30 and the second core component 4 having the winding 50b wound around the second core 40 are fabricated separately, and these are placed on a base 63 to obtain a choke coil product 12. Note that the same or similar members as those in the first embodiment are denoted by the same reference numerals, and descriptions thereof will be omitted as appropriate.

[0055] The first core 30 and the second core 40 of the second embodiment can be obtained by resin-coating the annular core 20 (see FIG. 2) and cutting it to form the flanges 32, 33, 42, 43 as shown in FIG. 20 (cutting process). The flanges 32, 33, 42, 43 are provided with locking receiving portions 32a, 42a, etc. for mounting the first core part 3 and the second core part 4 to a flange locking portion 64 of a base 63, which will be described later. In the illustrated embodiment, the locking receiving portions 32a, 42a are vertical cuts.

[0056] 21, the first core component 3 is obtained by winding the first winding 50a around the first core 30, and similarly the second core component 4 is obtained by winding the second winding 50b around the second core 40 (winding process). The first winding 50a and the second winding 50b are not continuous windings, but are each composed of separate windings or winding groups.

[0057] Specifically, the first winding 50a is wound around the first core component 3 such that the flange 32 of the first core 30 is the winding start portion 52 and the flange 33 is the winding end portion 53. The second core component 4 is wound with the second winding 50b such that the flange 43 of the second core 40 is the winding start portion 54 and the flange 42 is the winding end portion 53. The winding directions of the windings around the first core component 3 and the second core component 4 will be described later.

[0058] In the first embodiment, the winding 50 needs to be wound so as to straddle from the first core 30 to the second core 40, but according to this embodiment, the windings 50a, 50b only need to be wound around the arc-shaped first core 30 and second core 40, respectively, making the winding work extremely easy and also making it extremely easy to automate the winding.

[0059] 22, the first A terminal 37a and the first B terminal 37b are connected to the winding start portion 52 and the winding end portion 53 of the first winding 50a of the first core component 3, and the second A terminal 47a and the second B terminal 47b are connected to the winding start portion 54 and the winding end portion 55 of the second winding 50b of the second core component 4 (terminal attachment process, winding-terminal connection process). The connections between the terminals 37a, 37b and the first winding 50a, and between the terminals 47a, 47b and the second winding 50b can be made by various welding techniques such as resistance welding such as heat crimping and fusing, TIG welding and plasma welding, or soldering.

[0060] As shown in Figure 22, the terminals can be configured so that the first A terminal 37a and the first B terminal 37b protrude downward from the first core component 3, and the second A terminal 47a and the second B terminal 47b protrude downward from the second core component 4.

[0061] As described above, the first core component 3 and the second core component 4 are not connected by the windings but are independent components, and therefore are very easy to handle. When the windings 50a, 50b of the first core component 3 and the second core component 4 are wound in the same direction, the first core component 3 and the second core component 4 can have the same configuration.

[0062] 23, the first core part 3 and the second core part 4 are placed on the base 63 by bringing the flanges 32, 42 and 33, 43 close to each other so that they face each other (butting process). The base 63 is formed with flange locking parts 64 into which the lock receiving parts 32a, 42a of the flanges 32, 33, 42, 43 fit. In the illustrated embodiment, the flange locking parts 64 are protrusions into which the lock receiving parts 32a, 42a fit. The first core part 3 and the second core part 4 can be attached to the base 63 by engaging the flanges 32, 42 and 33, 43 with the flange locking parts 64, respectively. It is preferable that the base 63 is provided with claw pieces 65 for hooking onto the flange portions 32, 33, 42, 43, and that the flange portions are engaged with the claw pieces 65 so that the first core part 3 and the second core part 4 do not fall off the base 63.

[0063] 23, the base 63 is formed with cutouts avoiding the terminals 37a, 37b, 47a, and 47b, and terminal engagement pieces 66 that engage with the terminals 37a, 37b, 47a, and 47b are protruding from the cutouts. Then, as shown in FIG. 24, the first core part 3 and the second core part 4 are mounted on the base 63, and the terminals 37a, 37b, 47a, and 47b are engaged with the terminal engagement pieces 66, whereby these terminals protrude below the base 63 and are fixed.

[0064] 25, the choke coil 10 is resin-coated by insert molding, resin casting (potting), or the like, and then housed in a casing 60 (resin coating process), thereby obtaining a choke coil product 12 with terminals 37a, 37b, 47a, and 47b exposed downward. In the case of this embodiment, dummy pins as in the first embodiment are not necessary.

[0065] The obtained choke coil product 12 can be mounted on a substrate or the like and used as a choke coil for noise prevention circuits, waveform shaping circuits, resonance circuits, various switching circuits, and the like in AC devices such as power circuits and inverters. For example, by connecting terminal 37b and terminal 47b in series, choke coil product 12 can be used as a one-phase choke coil. Also, by connecting terminal 37a and terminal 47a, and terminal 37b and terminal 47b in parallel, it can be used as a two-phase choke coil.

[0066] Furthermore, by reversing the winding directions of the first winding 50a and the second winding 50b of the first core component 3 and the second core component 4 and connecting the terminals 37a and 47b, and the terminals 37b and 47a in parallel, the choke coil product 12 can be used as a common mode choke coil.

[0067] According to the second embodiment, the first core component 3 and the second core component 4 are arc-shaped, which makes it easy to wind the windings 50a, 50b, and also enables automation of the manufacture of the windings and the choke coil product 12, thereby making it possible to maximize the manufacturing efficiency of the choke coil product 12. Also, since the space factor of the windings can be increased compared to when the windings are wound around an annular core, the choke coil product 12 can be made smaller, lighter, more efficient, and with lower DC resistance.

[0068] The above description is for the purpose of explaining the present invention, and should not be interpreted as limiting the invention described in the claims or restricting the scope of the invention. Furthermore, the configuration of each part of the present invention is not limited to the above embodiment, and various modifications are possible within the technical scope described in the claims. [Explanation of symbols]

[0069] 10 Choke coil 12 Choke coil products 3. First core part 30 First Core 32,33 Flange 37a 1st A terminal 37b 1B terminal 4. Second core part 40 Second Core 42,43 Flange 47a 2nd A terminal 47b 2nd B terminal 50 Windings 51 Straddle

Claims

1. A core preparation process for preparing a first core and a second core, each of which is arc-shaped and insulated with a resin bobbin and has two end edges; a winding process for winding the first core and the second core; a butting process for butting edges of the first core part and the second core part on which the winding is provided against each other to form an annular shape; A method for manufacturing a choke coil, comprising: The winding process includes: a first core winding step for winding a first winding of an outward path so that one end edge side of the first core is a first winding start portion and the other end edge side is a first winding end portion to obtain a first core component, and a second core winding step for winding a second winding of an outward path so that one end edge side of the second core is a second winding start portion and the other end edge side is a second winding end portion to obtain a second core component; a third core winding step of winding a third return winding from the third winding start part to the third winding end part, with the second winding end part of the second core as a third winding start part and the second winding start part as a third winding end part, and a fourth core winding step of winding a fourth return winding from the fourth winding start part to the fourth winding end part, with the first winding end part of the first core as a fourth winding start part and the first winding start part as a fourth winding end part, In the forward process, the first winding and the second winding are wound in a state in which the first winding end portion is continuous with the second winding start portion, In the return process, the third winding and the fourth winding are wound in a state in which the third winding end portion is continuous with the fourth winding start portion. A method for manufacturing a choke coil.

2. The bobbin that insulates the first core and the second core has a shape having a flange portion on the outer periphery of the end edge. A method for manufacturing the choke coil according to claim 1.

3. The core preparation step is a step of insulating an annular core with the bobbin and then cutting the annular core to form the first core and the second core. A method for manufacturing the choke coil according to claim 1 or 2.

4. The second core winding step is performed in a state in which an outer circumferential edge of one flange portion of the first core and an outer circumferential edge of one flange portion of the second core are brought close to each other. A method for manufacturing the choke coil according to claim 2.

5. a first A terminal is formed on one end edge of the first core part, and the first winding start portion and the fourth winding end portion are electrically connected to the first A terminal; a second B terminal is formed on the other end edge of the second core part, and the second winding end portion and the third winding start portion are electrically connected to the second B terminal. A method for manufacturing the choke coil according to any one of claims 1 to 4.

6. The first winding start portion and the fourth winding end portion are electrically connected to the first A terminal, and the second winding end portion and the third winding start portion are electrically connected to the second B terminal by welding or soldering. A method for manufacturing the choke coil according to claim 5.

7. The winding direction of the first winding as viewed from the first winding start side is opposite to the winding direction of the third winding, The winding direction of the second winding as viewed from the second winding start portion side is opposite to the winding direction of the fourth winding. A method for manufacturing the choke coil according to any one of claims 1 to 6.

8. the winding direction of the first winding as viewed from the first winding start portion side is the same as the winding direction of the second winding as viewed from the second winding start portion side. A method for manufacturing the choke coil according to claim 7.

9. the winding direction of the first winding as viewed from the first winding start portion side is opposite to the winding direction of the second winding as viewed from the second winding start portion side. A method for manufacturing the choke coil according to claim 7.

10. The winding is a stranded wire. A method for manufacturing the choke coil according to any one of claims 1 to 9.

11. The butting step is performed by inserting an insulating spacer between at least one end edge of the first core and the second core. A method for manufacturing a choke coil according to any one of claims 1 to 10.

12. After the step of manufacturing a choke coil by the manufacturing method according to any one of claims 1 to 11, and a step of coating the obtained choke coil with a resin. Manufacturing method for choke coil products.

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