JP2015187591A - Toroidal coil device and current measuring device using same - Google Patents

Abstract

The present invention provides a toroidal coil device capable of increasing the number of turns of a coil as compared with the conventional one and improving noise resistance, and a current measuring device using the toroidal coil device. A toroidal coil device (1A) includes a cut (21) provided between a conductor pattern (3) and a flexible substrate (10) having a plurality of conductor patterns (3) arranged in parallel and supported by a flat sheet-like flexible substrate (2). It is formed by bending three-dimensionally in a toroidal shape. The conductor pattern 3 becomes a one-turn coil by bending, and each adjacent one-turn coil is connected by connecting terminals 3a and 3b at both ends to form a multi-turn coil. The toroidal coil device 1A is formed in a toroidal shape from the flexible substrate 10 with a rotational symmetry by the notch 21. Based on the three-dimensional shape, a multi-turn coil can be formed from a one-turn coil. The area can be increased more than before, and noise resistance can be improved. [Selection] Figure 1

Description

  The present invention relates to a toroidal coil device and a current measuring device using the toroidal coil device.

  2. Description of the Related Art Conventionally, a toroidal coil device including an air-core toroidal coil that does not have a magnetic circuit has been used as a current sensor that measures an alternating current flowing through an electric wire passing through the center hole. The toroidal coil is formed by bending a linear air-core solenoid coil so that its central axis is circular, and to form a toroidal coil. An air-core toroidal coil as a current sensor is also called a Rogowski coil. A toroidal coil for a current sensor forms a sheet-shaped air-core solenoid coil by, for example, a conductive pattern formed on both surfaces of a flexible sheet-shaped substrate and a conductive through hole connecting these two surfaces. Is easily formed (see, for example, Patent Document 1). However, in the toroidal coil of Patent Document 1, the presence of the land pattern for securing the connection by the conductive through hole becomes a constraint condition for the increase in the density of the conductor pattern, and the number of turns of the coil is increased beyond a certain limit. I can't. Further, the area surrounded by each one-turn coil is the sectional area of the sheet-like base material itself, and there is a limit to increasing the area.

  By the way, a plurality of conductor patterns are integrally formed on a flexible support body, and one-turn coils for each conductor pattern formed by bending the support body are connected in series to form an inductor used in a transformer or the like. There is a known method (see, for example, Patent Document 2).

JP 2008-241479 A JP 2002-043138 A

  However, in the forming method as shown in Patent Document 2 described above, although it is possible to connect by solder without using the conductive through hole, since the fitting of the slit and the claw is used in each solder connection portion, it is still The increase in the number of turns of the coil is limited. In addition, the method of forming a coil in Patent Document 2 is to form a coil on one side of a quadrangle because the one-turn coil is three-dimensionally formed, so that the area surrounded by the coil can be increased. Symmetry cannot be imparted to the toroidal coil.

  The present invention solves the above-described problems, and a toroidal coil device capable of increasing the number of turns of the coil as compared with the conventional one and improving noise resistance with a simple configuration, and current measurement using the same. An object is to provide an apparatus.

  In order to achieve the above object, a toroidal coil device of the present invention is a toroidal coil device having a toroidal coil, and the toroidal coil is supported by a sheet-like flexible substrate and a flexible substrate. A flexible substrate having a toroidal shape having a plurality of conductor patterns arranged in parallel with each other, and the flexible substrate is bent from a flat plate shape to a toroidal shape using a notch provided between the parallel conductor patterns. Each of the conductor patterns has a connection terminal for connecting each in series, and each of the conductor patterns is formed into a one-turn coil by bending, and each of the one-turn coils is connected to the connection terminal. It is characterized by having a multi-turn coil.

  In this toroidal coil device, the conductor pattern is a portion in which the average gap between the conductor patterns arranged in parallel with each other is on the inner peripheral side with respect to the outer peripheral side of the toroidal coil in a state where the flexible substrate is developed in a flat plate shape. Is wide.

  In this toroidal coil device, the connection terminal may have a flying lead structure in which the conductor pattern protrudes from the end of the flexible substrate.

  In this toroidal coil device, the connection terminals connected to each other may be protected by a resin.

  In this toroidal coil device, the connection terminal may be disposed on the outer peripheral side of the toroidal shape.

  In this toroidal coil device, the conductor pattern may be formed in multiple layers on the flexible substrate.

  In this toroidal coil device, the flexible substrate may have a conductor layer for electromagnetic shielding.

  In this toroidal coil device, a conductor for electromagnetic shielding surrounding the toroidal coil may be provided, and the conductor may be electrically insulated from the conductor pattern.

  In this toroidal coil device, a magnetic body for magnetic shielding surrounding the toroidal coil may be provided.

  In this toroidal coil device, each of the one-turn coils may be arranged at a constant interval along the toroidal direction of the toroidal coil.

  In this toroidal coil device, each one-turn coil may be arranged in a plane including the central axis of the toroidal coil.

  In this toroidal coil device, the connection terminal may have an oblique shape that connects each of the adjacent one-turn coils.

  This toroidal coil device may include a toroidal core that supports the flexible substrate from its toroidal inner side.

  In this toroidal coil device, the core may be made of a heat resistant material that can withstand a heat load at a temperature of 260 ° C. or higher and a time of 10 seconds or longer.

  In this toroidal coil device, the core may have a cut along a plane including the central axis thereof, and may be separable or openable / closable by the cut.

  In this toroidal coil device, the core may have a clearance space for avoiding the generation of stress due to contact with the connection terminal.

  This toroidal coil device may include a toroidal case that houses the toroidal coil.

  In this toroidal coil device, the case may be fixed by pressing the flexible substrate from the outer surface side of the flexible substrate around the connection terminal to a member that supports the flexible substrate from its toroidal inner side.

  In this toroidal coil, the case may be divided along a plane including the central axis.

  The toroidal coil device may include a toroidal case that houses the toroidal coil, and the case, the flexible substrate, and the core may be freely opened and closed so as to enter the central axis side from the outer peripheral side.

  In this toroidal coil device, the case may have a partition wall that prevents the flexible substrate housed in the case from being exposed when the case is opened and closed.

  In this toroidal coil device, the case may have a structure that prevents the electric wire generating the magnetic field that becomes noise from approaching the toroidal coil below a predetermined distance.

  A current measuring device of the present invention includes any of the above-described toroidal coil devices and a circuit board electrically connected to the toroidal coil, and the circuit board is configured to generate a current flowing through an electric wire inserted through the toroidal coil. It has a circuit for outputting a corresponding signal.

  According to the toroidal coil device of the present invention, since the flexible substrate has a cut, it can be formed in a toroid shape, and based on the three-dimensional shape, a multi-turn coil can be formed by a series connection of one-turn coils. Can be increased as compared with the prior art.

(A) is a partially broken perspective view of a toroidal coil device according to an embodiment of the present invention, (b) is an external perspective view of the toroidal coil device, and (c) is a sectional view of the toroidal coil device. (A) is a development view of a flexible substrate constituting the toroidal coil of the toroidal coil device, (b) is a plan view of a solenoid coil formed by bending and electrically connecting the flexible substrate in a cylindrical shape, and (c). Side view. (A) is a cross-sectional view of the flexible substrate, (b) is a plan view of the flexible substrate illustrating a repeating element of a group of conductor patterns, and (c) is a plane illustrating the line and space of the conductor pattern. Figure. (A) is a top view of the connection terminal part of the flexible substrate, (b) is a plan view showing a state in which the connection terminals are stacked and electrically connected. (A) is sectional drawing of the connecting terminal part, (b) is sectional drawing of the state which connected the connecting terminal electrically, (c) is sectional drawing of the connecting terminal protected by resin. Sectional drawing of the connection terminal part which shows the modification of the flexible substrate. (A) is a perspective view of the core which supports a flexible substrate in a toroid form, (b) is a perspective view which shows the other example of the same core. (A) is a perspective view of the middle stage which makes a flexible substrate a toroid shape, (b) is a perspective view of the state which inserted the core in the flexible board of the middle stage. (A) is sectional drawing of the toroidal coil apparatus which has the same core in the inside of a toroidal coil, (b) opened the C-shape using the toroidal coil apparatus for the electric current measuring device which concerns on one Embodiment of this invention. Sectional drawing of a state. (A) is sectional drawing of the connection terminal part which shows the other example of the flexible substrate, (b) is sectional drawing of the state which electrically connected the connection terminal, (c) is a deformation | transformation of the flexible substrate of (a) Sectional drawing which shows an example. (A) is sectional drawing of the connecting terminal part which shows the other example of the flexible substrate, (b) is sectional drawing of the state which connected the connecting terminal electrically. (A) is sectional drawing of the connecting terminal part which shows the other example of the flexible substrate, (b) is sectional drawing of the state which connected the connecting terminal electrically. The expanded view of the flexible substrate which comprises the toroidal coil of the toroidal coil apparatus which concerns on other embodiment. The perspective view in the middle of making the flexible substrate into a toroidal toroidal coil. (A) is a perspective view which shows the example of the core which supports the flexible substrate, (b) is sectional drawing of the connection terminal part and core of a toroidal coil apparatus which has the flexible substrate supported by the core. (A) is the perspective view of the electric current measurement apparatus which concerns on other embodiment, (b) is the perspective view which looked at the electric current measurement apparatus from another angle. The perspective view of the state which opened the same electric current measuring apparatus in C shape. (A) is sectional drawing which shows a mode that the electric current measuring apparatus is opened in C shape, and an electric wire is made to enter / exit in the center part. Sectional drawing of the state which took in the electric wire in the center part of the current measuring device, and closed it. (A) is sectional drawing of the toroidal coil apparatus which concerns on other embodiment, (b) is F section detailed sectional drawing of (a). (A) is sectional drawing which shows the press structure of the connection terminal part in the modification of the toroidal coil apparatus, (b) is sectional drawing of the press state by the press structure. (A) is a perspective view of the toroidal coil of the toroidal coil apparatus which concerns on other embodiment, (b) is a development view of the flexible substrate which comprises the toroidal coil. Furthermore, the expanded view of the flexible substrate which comprises the toroidal coil of the toroidal coil apparatus which concerns on other embodiment. The top view of the back surface of the flexible substrate. The perspective view in the middle of making the flexible substrate into a toroidal toroidal coil. The top view of the part which connects the conductor pattern of the front and back of the flexible substrate. (A) is the II sectional view taken on the line of FIG. 26, (b) is sectional drawing of the state which connected the connecting terminal of (a) electrically. (A) is the II-II sectional view taken on the line of FIG. 26, (b) is sectional drawing of the state which connected the connecting terminal of (a) electrically. The top view of the state in which the flexible substrate has a board | substrate extension part. The top view of the flexible substrate which specified the substrate extension part. Furthermore, the expanded view of the flexible substrate which comprises the toroidal coil of the toroidal coil apparatus which concerns on other embodiment. The elements on larger scale of the connection terminal part in FIG. (A) is the top view which arranged the connection terminal mutually connected of the same flexible substrate, (b) is the top view of the state which connected the connection terminal. FIG. 33A is a sectional view taken along line I3-I3 in FIG. 33A, and FIG. 33B is a sectional view taken along line I5-I5 in FIG. FIG. 33A is a sectional view taken along line I4-I4 of FIG. 33A, and FIG. 33B is a sectional view taken along line I6-I6 of FIG. (A) is the top view which arranged the connection terminal mutually connected of the flexible substrate which comprises the toroidal coil of the toroidal coil apparatus which concerns on other embodiment, (b) is the I7-I7 line cross section of (a). Figure. (A) is a plan view illustrating the connection terminals connected to each other on the flexible substrate in an up-and-down manner, (b) is a plan view in which the connection terminals are overlapped with each other, and (c) is a plan view of (b). I8-I8 line sectional drawing, (d) is sectional drawing of the state which connected the connection terminal of (c) mutually electrically. (A) and (b) are perspective views of a toroidal coil device according to still another embodiment. (A) is a perspective view of the electric current measurement apparatus which concerns on other embodiment, (b) is sectional drawing of (a). (A) and (b) are sectional drawings which show the modification of the same current measuring device, respectively. (A) and (b) are perspective views explaining the relationship between current measurement using a general toroidal coil device and a disturbance magnetic field. The top view which looked at the toroidal coil of the toroidal coil device concerning other embodiments from the central axis direction. Furthermore, the perspective view which permeate | transmits and displays the 1 turn coil of the toroidal coil of the toroidal coil apparatus which concerns on other embodiment. (A) is a perspective view which shows the current measurement by the current measuring apparatus using the toroidal coil apparatus, (b) is sectional drawing which shows the magnetic field in current measurement. (A) is a perspective view which shows the current measurement by the same electric current measurement apparatus in case an adjacent electric wire exists, (b) is sectional drawing which shows the magnetic field by an adjacent electric wire.

  Hereinafter, a toroidal coil device according to an embodiment of the present invention and a current measuring device using the same will be described with reference to the drawings. 1 to 4 show a toroidal coil device 1A according to an embodiment. As shown in FIGS. 1A, 1B, and 1C, the toroidal coil device 1A includes a sheet-like flexible base material 2 and a plurality of conductor patterns that are supported by the flexible base material 2 and that are parallel to each other. 3 is provided with a toroidal coil 1 formed by bending a flexible substrate 10 having 3 in a toroidal shape. In these drawings and the drawings shown below, the conductor pattern 3 is appropriately omitted. The toroidal coil 1 has an electromagnetic configuration in which a solenoid coil is bent in an annular shape, and has two terminals 1a and 1b corresponding to both terminals of the solenoid coil.

  After patterning the conductor pattern 3 in a planar state, the flexible substrate 10 is bent into a cylindrical shape as indicated by an arrow R, and is further bent using a notch 21 provided between the conductor patterns 3 arranged in parallel. (The shape of the surface of the donut). The surface of the toroidal coil 1 can be divided into areas A and E on the outer peripheral side, area C on the inner peripheral side, and areas B and D on the upper and lower ends. The area C on the inner peripheral side has a smaller area than the sum of the areas A and E on the outer peripheral side. The upper and lower end regions B and D are transition regions whose area increases from the inner peripheral side toward the outer peripheral side. In order to cope with this change in area, cuts 21 are provided on the inner peripheral side and upper and lower ends of the toroidal coil 1. In the figure, a toroidal direction TD and a poloidal direction PD, which are characteristic directions in the toroid, are shown. The toroidal direction TD is a circumference around the central axis of the toroidal coil 1.

  Each of the conductor patterns 3 becomes a one-turn coil by bending the flexible substrate 10. Each of the conductor patterns 3 has connection terminals 3a and 3b for connecting them in series at both ends. Each one-turn coil is formed into a multi-turn coil by connecting the connection terminals 3a and 3b. The connection terminals 3a and 3b, and therefore the portion where they are connected (referred to as connection portion 30) are arranged on the outer peripheral side of the toroidal coil 1.

  As shown in FIG. 2A, the flexible substrate 10 has a substantially rectangular outer shape in a state of being developed in a planar shape. Since the flexible base material 2 cannot be expected to stretch, a cut 21 is used to bend the planar flexible substrate 10 into a toroidal shape that is a three-dimensional curved surface. The cuts 21 form openings in which the substrate material including the flexible base material 2 is removed from the planar flexible substrate 10. The regions A, B, C, D, and E are distributed from one side of the substantially rectangular sides of the flexible substrate 10 facing each other toward the other side, that is, along the toroidal direction TD. The cuts 21 are formed in parallel in the regions B, C, and D at equal intervals. The repeating element Pe of the group of conductor patterns 3 is defined by the parallel repeating pattern. That is, each of the conductor patterns 3 constitutes a set of repeating elements Pe by a plurality (seven in this example).

  Each of the conductor patterns 3 is arranged at equal intervals in the outer peripheral areas A and E except for some changed portions, and is grouped in groups (seven) in the inner peripheral area C. They are arranged at equal intervals in parallel at narrower intervals than the outer peripheral side. The conductor pattern 3 in the region A is a pattern having a skewed shape that changes in a crank shape so as to be transferred onto an extension line of the adjacent conductor pattern 3, and the flexible substrate 2 does not exist at the tip thereof. The connection terminal 3a has a flying lead structure. The conductor pattern 3 in the region E is linear, and the tip thereof is a connection terminal 3 b supported on the flexible substrate 2. Terminal terminals 1 a and 1 b supported by the flexible base material 2 are drawn out at two corners of the substantially square diagonal position of the flexible substrate 10. The conductor pattern 3 is covered with a protective film 2a such as a solder resist or a coverlay except for the connection terminals 3a and 3b. In addition, since the conductor patterns 3 parallel to each other continue in the regions A, E, and C for a long time, the toroid formed by the flexible substrate 10 has a long and elongated cylindrical shape.

  As shown in FIGS. 2B and 2C, the flexible substrate 10 is rounded into a flat cylindrical shape as indicated by an arrow R so that the one side and the other side belonging to the regions A and E are close to each other. Each of the conductor patterns 3 is electrically connected between the corresponding connection terminals 3a and 3b. The flexible substrate 10 becomes a solenoid coil 10a by this electrical connection. Here, referring to FIG. 2A described above, the electrical wiring constituting the solenoid coil 10a will be described through the connection between the terminals 1a and 1b and the connection terminals 3a and 3b. In the figure, the connection terminal x2 is a connection terminal 3a having a flying lead structure, and the connection terminals x1 and x3 are connection terminals 3b on the flexible substrate 2.

  In FIG. 2A, the wiring from the terminal 1a passes through the conductor pattern 3 connected to the terminal 1a to reach the connection terminal x1, and the connection terminal x1 is electrically connected to the connection terminal x2 of the adjacent conductor pattern 3. Connected to. Here, the flexible substrate 10 is in a state of being rounded into a cylindrical shape. The wiring from the connection terminal x2 passes through the conductor pattern 3 connected to the connection terminal x2, and reaches the connection terminal x3. Similarly, the connection terminal x3 is electrically connected to the terminal 1b, and the electrical wiring from the terminal 1a to the terminal 1b, that is, a solenoid coil in which a plurality of one-turn coils of one conductor pattern 3 are connected in series. 10a is formed.

  The flexible substrate 10 is manufactured by a general manufacturing process using, for example, a general flexible substrate having a copper foil layer on a resin sheet. The manufacturing process includes, for example, the formation of the conductor pattern 3 by patterning of copper foil, the formation of the protective film 2a by coating, laminating, patterning, etc., the formation of the cuts 21 and the outer shape, the terminals 1a, 1b and the connection terminals 3a, 3b. This is a step of performing plating or the like. The manufacture of the flexible substrate 10 is not limited to such a subtracting method of removing unnecessary copper foil by patterning, but an additive method of forming a conductive pattern 3 by adding a conductive material on the flexible base 2 or Can be performed by a combination of these. For example, a polyimide resin is used for the flexible substrate 2.

  The electrical connection between the connection terminals 3a and 3b is performed by, for example, rolling the flexible substrate 10 into a cylindrical shape so that the connection terminals 3a and 3b overlap each other with the solder paste applied to the connection terminals 3a and 3b. This can be done by soldering. Further, instead of using the solder paste, the connecting terminals 3a and 3b overlapping each other may be soldered by passing through a solder bath while contacting the solder solution. Further, the connection terminals 3a and 3b may be electrically connected using a conductive adhesive or an anisotropic conductive resin.

  FIG. 3A shows a cross-sectional structure of the flexible substrate 10. The flexible substrate 10 is configured by laminating a conductive layer of the conductor pattern 3 and an insulating resin layer of the protective film 2 a on the flexible base material 2. The connection terminal 3 a has a flying lead structure in which the conductor pattern 3 protrudes from the end portion of the flexible substrate 2. Such a structure can be formed, for example, by evaporating and removing the flexible substrate 2 using laser light. The connection terminal 3b is a normal terminal structure of a flexible substrate in which the entire lower surface is supported by the flexible base material 2.

  FIG. 3B shows a repetitive element Pe composed of a group of conductor patterns 3. In the conductor pattern 3, the ratio L / S between the pattern width (referred to as line L) and the gap between patterns (referred to as space S) is, for example, L / S = 1, that is, L = S.

  3 (b) and 3 (c) show that the average gap between the conductor patterns 3 arranged in parallel with each other is wider on the inner peripheral side than on the outer peripheral side of the toroid in the state where the flexible substrate 10 is developed in a plane. Is shown. Here, L = LO and S = SO within the width WO of the repeating element Pe in the outer peripheral areas A and E, and L = LI and S = SI within the width WI of the repeating element Pe in the inner peripheral area C. And Note that from the above L / S = 1, LO = SO, LI = SI. The average gap on the outer peripheral side, that is, in the areas A and E, is SO. In addition, the average gap on the inner peripheral side, that is, in the region C, is a gap (space) when the lines LI are rearranged at equal intervals in the width WO, and is indicated by Sa in the figure, and Sa> SO. is there. The result of Sa> SO is that there is an opening formed by the notch 21 shown in FIG. 2A described above, and the space of the opening is included in Sa when averaging. .

  4A and 4B show a state in which the connection terminals 3a and 3b of the flexible substrate 10 are brought close to each other and electrically connected in a state where they are overlapped with each other. The left and right repetitive elements Pe facing each other are both end portions belonging to the same repetitive element Pe. Of the plurality of connection terminals 3a and 3b in the repetitive element Pe, each one of the connection terminals 3a and 3b is not connected in its own repetitive element Pe, and each of the connection terminals 3a in another adjacent repetitive element Pe. , 3b. The repeating element Pe having the final terminals 1a and 1b is special, and the terminals 1a and 1b are terminated.

  5A, 5B, and 5C show how the connecting portion 30 is formed. That is, (a) the connection terminal 3a of the flying lead structure is brought close to and overlapped with the connection terminal 3b on the flexible substrate 2, (b) connected to each other by the solder 31, and finally (c) connected to each other. The connection terminals 3a and 3b are protected by the protective resin 32, and the connection portion 30 is formed.

  Since the protective resin 32 protects the connection portion 30, stress concentration does not occur in the conductive material such as solder or conductive resin of the connection portion 30, and reliability can be maintained. In addition to reinforcing the flexible substrate 2, the conductive material is prevented from being deteriorated. As the protective resin 32, an acrylic resin, an epoxy resin, a silicone resin, or the like can be used as one that prevents electrical continuity or can prevent a short circuit with an adjacent pattern. For example, when an anisotropic conductive resin is used as the conductive material, the anisotropic conductive resin also serves as the protective resin 32.

  FIG. 6 shows a modification of the flexible substrate 10. The flexible substrate 10 includes a conductor layer 33 for electromagnetic shielding. The conductor layer 33 is provided on the outer surface of the toroidal coil 1, that is, on the surface side of the flexible substrate 10 so as to include the conductor pattern 3 arranged in a toroid shape. In the toroidal coil 1, the conductor layer 33 forms a closed space, and the conductor pattern 3 is electromagnetically shielded in the closed space. The conductor layer 33 is set to a ground potential via an appropriate ground connection terminal, for example. What is necessary is just to form a ground connection terminal similarly to terminal 1a, 1b etc. in the edge part of the flexible substrate 10, for example. The flexible substrate 10 is electrically connected to the connection terminals 3a and 3b and is formed into a toroidal three-dimensional shape to form the toroidal coil 1. In this state, the toroidal coil device 1A can be used for current measurement and the like.

  According to the present embodiment, since the flexible substrate 10 has the cuts 21, a toroidal three-dimensional curved surface can be easily formed, and a multi-turn coil can be formed by serial connection of one-turn coils based on the shape. The number of turns can be increased than before. That is, the notch 21 makes it possible to bend the linear solenoid coil 10a into a toroid having a three-dimensional curved surface. The toroidal coil 1 (toroidal coil device 1A) formed in this manner can be excellent in symmetry around its central axis. Therefore, the toroidal coil device 1A can effectively cancel the noise magnetic field due to its rotational symmetry. Further, the solenoid coil 10a can be formed from the flexible substrate 10 by direct electrical connection between the connection terminals 3a and 3b of the conductor pattern 3 without forming vias or lands. The number of turns of the coil can be increased. Further, since the one-turn coil is formed in three dimensions, the area surrounded by the coil can be increased, and the sensitivity of the toroidal coil can be increased in the same manner as the number of turns.

  By the way, the elements that limit the increase in the number of turns in the structure of the toroidal coil 1 are, for example, the wiring pitch of the conductor pattern 3 on the inner surface (region C) of the toroid or the connection portion 30 formed on the outer periphery of the toroid. It is considered a formation structure. The wiring pitch of the conductor pattern 3 can be set to the minimum pitch according to the design rule for a normal flexible substrate. In general, the toroidal coil has a wider wiring pitch on the outer periphery than on the inner periphery. Therefore, by forming the connection portion 30 on the outer peripheral portion of the toroidal coil, a larger area than that on the inner surface of the toroid can be used, design rules can be greatly relaxed, and restrictions on the increase in the number of turns are relaxed. The Further, when the toroidal coil 1 is used as a current measuring sensor for electric wires passing through the center of the toroidal coil 1, since the magnitude and change of the magnetic field are large on the inner peripheral side and small on the outer peripheral side, the connecting portion 30 is formed on the outer peripheral portion. As a result, the influence of the displacement of the wiring on the measurement accuracy can be reduced.

(Toroidal coil device with a supporting core)
7, 8, and 9 show a toroidal coil device 1 </ b> A including a toroidal core that supports the toroidal flexible substrate 10 from the inner space side. As shown in FIGS. 7 (a) and 7 (b), the core 4 divided into two or four or generally any number can be used as a member for supporting the toroidal flexible substrate 10 from the inside. The dividing surface of the core 4 is preferably formed so as to be along a plane including the central axis of the toroid. In addition, the core 4 is not limited to being completely separable, and may be opened and closed by a cut as a state in which a part of the core 4 is left as a skin. In this case, it becomes easy to maintain the core 4 as a toroid, and handling becomes easy.

  The core 4 is formed by resin molding, for example. When the toroidal coil device 1A is used as a current measurement sensor, the core 4 is not limited to resin, but can be formed of a non-magnetic material having a magnetic property that does not affect the performance of the sensor. The core 4 is formed of a heat resistant material that can withstand a heat load at a temperature of 260 ° C. or higher and a time of 10 seconds or longer, for example. Thereby, for example, when the flexible substrate 10 is soldered, it can be effectively used as a jig. When the core 4 has a deformation heat resistance of 260 ° C. and 10 seconds or more, for example, Sn—Ag—Cu soldering can be performed.

  As shown in FIGS. 8A and 8B, when the flexible substrate 10 is bent from the state of the solenoid coil 10a into a toroid shape, the cores 4 divided from the toroid shape are sequentially inserted into the solenoid coil 10a. By doing so, the toroidal coil 1 is formed. At the time of this insertion, the core 4 can be divided or opened and closed, so that the insertion work is possible and easy. In order to facilitate the insertion, the core 4 is preferably formed using a resin having good lubricity.

  FIG. 9A shows a toroidal coil device 1 </ b> A having the divided core 4 inside the toroidal coil 1. In the toroidal coil device 1A, the position of the split surface of the core 4 is made to coincide with the portion where the cylindrical end of the solenoid coil 10a faces. As shown in FIG. 9B, since the notch 21 exists in the flexible substrate 10 from the inner peripheral side and the inner peripheral side of the toroidal coil 1 to the upper part and the lower part, and the core 4 has a split surface, the toroidal The coil device 1A can be opened in a C shape. The terminals 1a and 1b are located at different ends of the C shape. The shape of the toroidal coil device 1A is stably maintained by the core 4, and the opening / closing function allows the electric wire 9 to enter and exit from the outer peripheral side to the central axis side (central hole portion). Therefore, the circuit board 6 is provided in the toroidal coil device 1 </ b> A, and the terminals 1 a and 1 b are electrically connected to the circuit board 6, whereby the current measuring device 1 </ b> B that is detachable from the electric wire 9 can be configured. With such an opening / closing function, it can be used for the purpose of measuring the current of an already installed electric wire. In this case, the circuit board 6 has an electric circuit for obtaining a current value based on a measured value of an alternating magnetic field around the electric wire 9 by an alternating current flowing through the electric wire 9.

(Multilayer flexible substrate)
10, FIG. 11, and FIG. 12 show other examples of the flexible substrate 10. FIG. 10A and 10B show a flexible substrate 10 having a conductive pattern 3 having a two-layer structure. This flexible substrate 10 has a connection terminal 3a having a flying lead structure and a connection terminal 3b on the flexible base material 2 on the front and back of one end of the flexible substrate 10, respectively, and the same connection is made on the other end. Each of the terminals 3a and 3b has a reverse arrangement from the one end side. These conductor patterns 3 are connected to the connection terminals 3a and 3b with, for example, solder 31 to form solenoid coils on the front surface and the back surface of the flexible base material 2, respectively. Thereafter, two solenoid coils on the front and back are connected in series and bent in a toroidal shape to form a toroidal coil 1 having a double coil structure. The series connection of the two solenoid coils may be performed before or after the toroidal shape. Since the front and back connecting portions 30 are concentrated at substantially the same position, the connecting operation can be efficiently performed by batch processing.

  A flexible substrate 10 shown in FIG. 10C is provided with a conductor layer 33 for electromagnetic shielding on the flexible substrate 10 having the conductor pattern 3 having the two-layer structure described above. The conductor layer 33 forms a closed space in the toroidal coil 1, and the two-layered conductor pattern 3 is accommodated in the closed space for electromagnetic shielding. The conductor layer 33 is set to the ground potential via an appropriate connection terminal, for example. This can prevent a problem that the coil serves as an antenna to pick up electromagnetic noise.

  FIGS. 11A and 11B show a flexible substrate 10 having a conductor pattern 3 having a four-layer structure, generally a multilayer structure. This flexible substrate 10 has one connection terminal 3a having a flying lead structure and three connection terminals 3b on the flexible base material 2 on one end side of the flexible substrate 10, respectively, and on the other end side, Similar connection terminals 3a and 3b are provided in the reverse arrangement from the one end side. The configuration of connecting the connection terminals 3a and 3b on the front surface and the back surface with the solder 31 is the same as the configuration shown in FIG. In the inner conductor pattern 3, the same type of connection terminals 3 b are connected by the solder 31. These electrical connections are not limited to the solder 31, and can be performed using a conductive material such as a conductive adhesive or an anisotropic conductive resin. The whole of these connection parts is protected by the protective resin 32, and the connection part 30 is formed. The flexible substrate 10 having such a multi-layered conductor pattern 3 can also be provided with a conductor layer 33 for electromagnetic shielding as described above. Further, since the locations of the electrical connections are concentrated at substantially the same position, the connection work can be performed efficiently by batch processing. By using the conductor pattern 3 having a multilayer structure, the number of turns of the toroidal coil 1 can be increased.

  12 (a) and 12 (b) show a protective substrate 2b obtained by extending a part of the flexible substrate 2 below the connection terminal 3b in the flexible substrate 10 shown in FIGS. 11 (a) and 11 (b). The flexible substrate 10 which has is shown. In the flexible substrate 10, the connection portions of the connection terminals 3 b are separated by the protective base material 2 b, so that the insulation between the solders 31 can be more reliably performed.

  Generally speaking, the connection part 30 is formed by connection terminals 3a and 3b, which are parts without a solder resist or a cover lay in a general flexible substrate and partly without a flexible base material. ing. Further, the connection portion 30 includes a connection terminal 3 b in which the tip of the conductor pattern 3 is made to coincide with or retract from the end face position of the flexible base material 2, and the conductor pattern from the end face position of the flexible base material 2. In some cases, the connecting terminals 3a of the flying lead structure protruding 3 are overlapped with each other. By connecting the connection terminals 3a and 3b in such a manner that the connection terminals 3b and 3b are overlapped with each other, the connection area can be increased as compared with the connection using vias. And reliability. According to such a connection part 30, the formation process of the connection part 30 is easy in the single-sided, double-sided, generally multi-layered flexible substrate 10, the productivity can be improved, and the cost can be reduced.

  Moreover, each connection part 30 mentioned above is formed by abutting the end surfaces of the flexible substrate 10 and overlapping the conductors of the conductor pattern 3, and a portion without the flexible base material 2 is formed. If there is such a gap portion without the flexible base material 2 and the degree of short-circuiting of adjacent turns due to conductor bending in the appearance inspection of the connection part 30 of the double-sided pattern, it can be easily performed by looking from one side. it can. Further, since the gap is open, it is possible to prevent thermal stress in the pruning direction from being applied to the conductor of the connecting portion 30.

(Other embodiments)
13, 14 and 15 show a toroidal coil 1 according to another embodiment. As shown in FIGS. 13 and 14, the flexible substrate 10 of the toroidal coil 1 has the conductor pattern 3 symmetrically on the front and back. That is, when the flexible substrate 10 is turned over so as to be turned upside down in this figure, the pattern before turning over and the pattern after turning over are the same. The flexible substrate 10 is obtained by adding the conductor pattern 3 to the back surface side and connecting the terminal 1b to the conductor pattern 3 on the back surface side in the flexible substrate 10 shown in FIG. The other configurations are almost the same. The terminals 1a and 1b are arranged on the same side, not on the diagonal position of the substantially rectangular flexible substrate 10 in the unfolded state. The conductor pattern 3 on the back side is shown as a perspective view by a dotted line.

  The terminal 1a and the connection terminals x1 to x5 belong to the conductor pattern 3 on the front surface side, and the terminal 1b and the connection terminals y1 to y5 belong to the conductor pattern 3 on the back surface side. The connection terminals x2, x4, y2, and y4 are connection terminals 3a having a flying lead structure, and the connection terminals x1, x3, x5, y1, y3, and y5 are connection terminals 3b on the flexible substrate 2.

  Next, wiring formed by rounding the flexible substrate 10 into a cylindrical shape and electrically connecting the terminals 1a and 1b and the connection terminals x1 to x5 and y1 to y5 will be described. First, on the surface, the wiring from the terminal 1a passes through the conductor pattern 3 connected to the terminal 1a and reaches the connection terminal x1, and the connection terminal x1 is electrically connected to the connection terminal x2 of the adjacent conductor pattern 3. Is done. Similarly, from the connection terminal x3 to the connection terminal x5 through the connection terminal x4. The connection terminal x5 on the front surface is connected to the connection terminal y1 closest to the back surface thereof by an appropriate connection means such as an external wiring or a via structure, whereby a front-back connection is made.

  Subsequently, on the back surface, it passes through the conductor pattern 3 of the connection terminal y1 to reach the connection terminal y2, from the connection terminal y2 to the connection terminal y3 via the adjacent conductor pattern 3 in sequence, and so on. Thus, the connection terminal y3 is connected to the connection terminal y5 via the connection terminal y4. The connection terminal y5 passes through the conductor pattern 3 connected to the connection terminal y5, and reaches the terminal 1b that is the end thereof. These electrical connections can be collectively made in the manner described in relation to FIGS. 10 (a) and 10 (b).

  By the electrical connection of each of the connection terminals described above, the solenoid coil formed by the conductor pattern 3 on the front surface of the cylindrical flexible substrate 10 and the solenoid coil formed by the conductor pattern 3 on the back surface are formed in a state of being connected in series with each other. The In these coils, for example, the front side solenoid coil is called a lead coil, and the back side solenoid coil is called a return coil. These can be compared to a combination of right and left threads. The flexible substrate 10 formed in a cylindrical shape is further bent into a toroid shape to form a toroidal coil 1. This toroidal coil 1 has a double-coil structure, and has a coil with twice the number of turns as in the case of only one side.

  As is well known, the toroidal coil 1 having such a lead coil and a return coil is in the toroidal direction TD (the large circumferential direction of the donut) existing in the toroidal coil 1 shown in FIGS. One turn coil is deleted. Further, due to the presence of the return coil, the terminals 1a and 1b are not located diagonally to each other, but are located on the same side of the substantially rectangular flexible substrate 10.

  FIGS. 15A and 15B show a toroidal device 1A including a core 4 that supports the toroidal coil 1 having the conductor pattern 3 having the above-described two-layer structure. The core 4 has a recess 4a at a position corresponding to the position where the connection portion 30 is arranged so as not to contact the connection portion 30 facing the back surface side of the flexible substrate 10, that is, the closed space side formed by the toroid. doing. Due to the clearance space formed by the recess 4a, it is possible to avoid the generation of stress due to contact with the connection portion 30 and thus the connection terminals 3a and 3b constituting the connection portion 30. Thereby, the connection part 30 can be protected. In addition, the core 4 is illustrated as a three-divided configuration composed of one of two divisions and two of four divisions, but can generally be any division and division number.

  Moreover, when using the toroidal coil 1 as a highly accurate sensor for current measurement, the symmetry of the whole toroidal coil 1 and the symmetry between each one-turn coil are calculated | required. This is because the current of the electric wire passing through the central hole portion of the toroidal coil 1 is a measurement target, but the influence of the magnetic field due to the current not passing through the central hole and the external magnetic field due to other factors is canceled by the symmetry of the toroidal coil 1. Because. In this case, the relief space formed by the recess 4 a can maintain the symmetry of the coil without being affected by the thickness variation of the connection portion 30. Thereby, the measurement performance such as current measurement by the toroidal coil 1 can be improved without the shape variation of the connecting portion 30 affecting the rotational symmetry of the toroidal coil 1.

(Toroidal coil device with case and current measuring device)
16 to 19 show a toroidal coil device 1A and a current measuring device 1B according to still another embodiment. As shown in FIGS. 16A, 16B, 17 and 18, the toroidal coil device 1A includes a toroidal case 5 for housing the toroidal coil 1 formed using the flexible substrate 10. Is. More specifically, this toroidal coil device 1A is obtained by housing the toroidal coil device 1A having the toroidal coil 1 and the core 4 shown in FIGS. 13, 14, and 15 in a case 5. The case 5 has a substrate storage portion 51 for storing the circuit board 6 in addition to the toroidal main body portion 50. The circuit board 6 includes a circuit that is electrically connected to the toroidal coil 1 formed of the flexible board 10 and processes an output from the toroidal coil 1. The toroidal coil device 1 </ b> A becomes a current measuring device 1 </ b> B by including the circuit board 6.

  The main body 50 is divided into two divided bodies along a dividing surface 50a that is a plane including the central axis, and one of the two divided bodies is further divided along the same dividing surface 50a to form a four-divided body. It has become. Each of the four divided bodies is connected to the two divided bodies by a hinge 5a in the outer peripheral portion of the toroid so as to be freely opened and closed. Both quadrants have a claw 5b and a hook 5c that engage each other to maintain the closed state. The dividing surface 50a of the case 5 is provided with a partition wall 52 for protecting the flexible substrate 10 accommodated in the case 5 from being exposed when the case 5 is opened. The partition wall 52 has, for example, a bellows structure that is flexibly deformed at the hinge 5a. The partition wall 52 can be formed by attaching a sheet material, providing a coating film, or filling a sealing material.

  A toroidal coil 1 made of a flexible substrate 10 is supported by a core 4 that is divided into two or four parts, and is housed in a case 5 that can be divided. The toroidal coil device 1A is configured to ensure the symmetry of the toroidal coil 1 (symmetry around its rotation axis, symmetry between each one-turn coil, symmetry of pitch between coils, etc.). For example, each divided surface is configured to be joined with a flatness equal to or less than the pitch between the coils. Further, the partition 52 is made as thin as possible in order to make the pitch between the coils close to a constant value. In addition, the case 5 may be provided with an engaging concavo-convex structure that can be positioned or a fitting structure in place of the plane division surface so that the positional deviation of the opening / closing surface does not occur.

  The current measuring device 1B including such a toroidal coil device 1A can be attached to and detached from the electric wire and used to measure an alternating current flowing through the electric wire. In this case, electronic elements necessary for current detection, such as a transistor and an integrator, are mounted on the circuit board 6 in the board housing portion 51. The board storage 51 is provided with a socket 51 a having terminal pins for inputting power to the circuit board 6 and inputting and outputting signals. The terminals 1 a and 1 b of the flexible substrate 10 are electrically connected to the circuit board 6 by wiring that passes through the main body 50 and reaches the circuit board 6 in the substrate housing 51.

  As shown in FIG. 18, the case 5, the flexible substrate 10 (toroidal coil 1) housed in the main body 50 of the case 5, and the core 4 that supports the flexible substrate 10 constitute a toroidal coil device 1 </ b> A. The case 5 is integrally opened and closed as the C shape of the case 5 is opened and closed. These opening / closing operations can be performed by the presence of the cuts 21 in the flexible substrate 10 and the split structure of the core 4 and the case 5. The opening / closing function allows the electric wire 9 to enter and exit from the outer peripheral side of the toroidal coil device 1A to the central axis side. Thereby, it can use for the use which measures the electric power of the electric wire already installed. Moreover, since it has the hinge 5a and the nail | claw 5b and the hook 5c, when changing the electric wire used as the object of electric power measurement, the same individual | organism | solid can be used repeatedly repeatedly. FIG. 19 shows a state in which the electric wire 9 is taken into the central hole of the toroidal coil device 1A and the toroidal coil device 1A is closed. The current measuring device 1B outputs a signal corresponding to a time change of the magnetic field H based on a change in the current flowing through the electric wire 9 inserted through the central hole as a current measurement result to the outside through the circuit board 6 and the socket 51a. To do.

(Still another embodiment)
20A and 20B show a toroidal coil device 1A according to still another embodiment. This toroidal coil device 1A includes the flexible substrate 10, the core 4, and the case 5 shown in FIGS. 13, 15, and 16 described above, and further has a connection portion 30 formed by connecting connection terminals 3a and 3b. Is provided with a pressing structure that fixes the peripheral flexible substrate 10 therebetween. That is, the case 5 fixes the flexible substrate 10 by pressing the flexible substrate 10 against the core 4 which is a member that supports the flexible substrate 10 from the inside of the toroidal shape, from the outer surface side of the flexible substrate 10 around the connection portion 30. doing.

  The core 4 has a concave portion 4a on the surface where the connecting portion 30 is located, and has a convex portion 4b at a position close to the opening edge of the concave portion 4a. The concave portion 4a forms a circumferential groove, and the convex portion 4b is formed in a bank shape on both sides of the groove formed by the concave portion 4a.

  As in the case of the core 4, the case 5 has a concave portion 5 d on the surface where the connecting portion 30 is located, and has a convex portion 5 e in a position close to the opening edge of the concave portion 5 d. As in the case of the core 4, the concave portion 5 d forms a circumferential groove, and the convex portion 5 e is formed in a bank shape on both sides of the groove formed by the concave portion 5 d. The convex part 4b of the core 4 and the convex part 5e of the case 5 are in positions that face each other and face each other.

  The flexible substrate 10 is sandwiched around the connection portion 30 by the convex portions 4b of the core 4 and the convex portions 5e of the case 5 that face each other, and the position in the case 5 is fixed. That is, the convex portion 5 e of the case 5 presses the outer surface of the flexible substrate 10 around the connection portion 30, and the convex portion 4 b of the core 4 that is a supporting member disposed on the inner surface side of the flexible substrate 10. A pressing structure is configured to fix the flexible substrate in between. As a result, the connection portion 30 is not in close contact with the case 5, and even when a force is applied to the case 5 from the outside, the connection portion 30 is not directly subjected to stress, and reliability can be ensured.

  The assembly of the toroidal coil device 1A is performed by first forming the flexible substrate 10 in a solenoid shape, then inserting the core 4 into a toroid shape, and installing the flexible substrate 10 supported by the core 4 in the case 5. Is called. For example, the case 5 is divided into inner and outer cylinders and the flexible substrate 10 is installed in the case 5 in order to facilitate the installation and finally bring the outer surface of the flexible substrate 10 into pressure contact with the convex portion 5e. After that, the pressing force may be applied between the inner and outer cylinders. Further, a core may be used in which a cavity is provided in the core 4 along the large circumferential direction of the toroid, that is, the toroidal direction, and the convex portion 4b of the core 4 can be moved back and forth in the cavity direction. In this case, the flexible substrate 10 and the core 4 are inserted into the case 5 with the convex portion 4b retracted, and after these insertions, the convex portion 4b is projected by filling the cavity of the core 4. It may be.

  FIGS. 21A and 21B show a modification of the pressing structure by the convex portion 5e of the case 5 described above. In this modification, the convex portion 5 e is movable toward the core 4. A hole 5f is provided in the outer wall of the case 5, and the hole 5f is provided with a movable body 53 that is movable in the direction perpendicular to the outer wall, and the tip of the movable body 53 is a convex portion 5e. As shown in FIG. 21A, when the flexible substrate 10 and the core 4 are inserted into the case 5, the moving body 53 is moved backward. Further, as shown in FIG. 21B, when the flexible substrate 10 is fixed, the moving body 53 may be advanced to apply pressure. The pressure can be applied in any way. For example, the movable body 53 is made of an elastic body such as rubber, and the flexible substrate 10 can be pressed with its elasticity by pushing the movable body 53 against the frictional force with the hole 5f. The holes 5f and the moving body 53 do not need to be continuous in the toroidal direction, and may be provided in a jumping manner to fix the flexible substrate 10 at an appropriate interval.

(Still another embodiment)
22 (a) and 22 (b) show a toroidal coil 1 according to still another embodiment. The toroidal coil 1 includes a connection portion 30 that electrically connects the connection terminals 3a and 3b to the inner peripheral side by positioning the connection terminals 3a and 3b on the inner peripheral side of the toroid. The flexible substrate 10 developed in a planar shape has a substantially rectangular outer shape, and has a linear notch 21 that does not form an opening therein. The other configuration is the same as that of the toroidal coil 1 including the flexible substrate 10 in which the connection terminals 3a and 3b are arranged on the outer peripheral side shown in FIGS.

(Still another embodiment)
23 to 28 show a toroidal coil 1 according to still another embodiment. As shown in FIGS. 23, 24, and 25, the toroidal coil 1 has a conductor pattern 3 on both the front and back surfaces, like the flexible substrate 10 shown in FIGS. 13 and 14 described above. The conductor pattern 3 on the back side is shown as a perspective view by a dotted line.

  The toroidal coil 1 by the flexible substrate 10 is configured to wind from one side (solid arrow) and to wind back from the other side (dotted arrow). The connection from the winding surface to the rewinding surface is performed by directly connecting the conductor patterns 3 on the front surface and the back surface by soldering or the like. In order to perform this direct connection, a notch 22 is formed in a part of the flexible substrate 2. Further, the electrodes of the terminals 1a and 1b at the start and end of winding are both connected via a flexible base 2 or a protective film 2a such as a solder resist or a coverlay so as not to generate noise due to an external magnetic field. The electrode patterns overlap each other. The circuit board that processes the output from the toroidal coil 1 is connected with both the winding start and winding end terminals 1a and 1b arranged at the same position on the circuit board. Thus, when the toroidal coil 1 is used as a current sensor that measures the alternating current of the electric wire passing through the central hole as a measurement target, an external magnetic field against a disturbance magnetic field such as a magnetic field or other magnetic field other than the measurement target. Resistance can be ensured.

  Wiring formed by electrical connection from the terminal 1a to the terminal 1b through the conductor pattern 3 will be described with reference to FIG. First, the wiring from the terminal 1a on the front surface passes through the conductor pattern 3 connected to the terminal 1a to reach the connection terminal x2, and the connection terminal x2 is electrically connected to the connection terminal x3 of the adjacent conductor pattern 3. The Similarly, from the connection terminal x4 to the connection terminal x6 through the connection terminal x5. The conductor at the tip of the connection terminal x6 is connected to the connection terminal x7, and the conductor 1c in the middle of the connection terminal x6 is overlaid on the connection terminal y2 extended from the conductor pattern 3 on the back surface. Connected directly to 1d. The connection between the conductors 1c and 1d forms a front / back connection.

  Subsequently, on the back surface, the conductor pattern 3 of the connection terminal y2 is passed to the connection terminal y3, and the connection terminal y3 is sequentially passed through the adjacent conductor pattern 3 to the connection terminal y4. Thus, the connection terminal y4, the connection terminal y5, and the connection terminal y6 are reached. The connection terminal y6 passes through the conductor pattern 3 connected to the connection terminal y6, and reaches the terminal 1b that is the end thereof.

  The connection part of the above-described electrical connection will be further described. As shown in FIG. 26, due to the presence of the notch 22, when the end portions of the flexible substrate 10 are butted and the connection terminals x6 and y2 are overlapped, the conductors 1c and 1d of the connection terminals x6 and y2 face each other directly. It becomes a state. Accordingly, as shown in FIGS. 27A and 27B, the connection portion 30 that performs electrical connection from the front surface side to the back surface side is easily formed using only the flexible substrate 10. The connection terminal x7 is a dummy terminal used for reinforcement and shape alignment. Further, as shown in FIGS. 27A and 27B, the connection between the conductor patterns 3 on the front surface and the connection between the conductor patterns 3 on the back surface are performed. The electrical connection between the front and back surfaces, between the front and back surfaces, and between the back and back surfaces can be performed collectively in the manner described with reference to FIGS. 10 (a) and 10 (b).

  29 and 30 show an example in which the flexible substrate 10 includes a substrate extension 7 for protecting the flying leads. When manufacturing the toroidal coil from the flexible substrate 10 and the flexible substrate 10, if the terminal end of the connection terminal 3 a of the flying lead structure is in a floating free state, the risk of the connection terminal being bent or damaged There is. Therefore, the flexible substrate 10 is provided with a substrate extension 7 formed by extending the flexible base material 2 for protecting and holding the connection terminal 3a having the flying lead structure. The substrate extension 7 is provided with a plurality of positioning holes 7a for positioning and handling the flexible substrate 10. For example, in a joining process such as soldering for forming a solenoid coil, the positioning and the flexible substrate 10 are stretched and held using the positioning holes 7a. The board extension 7 is removed by cutting after soldering or the like.

  31 to 34 show a flexible substrate 10 for a toroidal coil according to still another embodiment. The flexible substrate 10 is different in the shape of the conductor pattern 3 and the shape of the connection terminals x2, x3, y3, y4, etc. in the flexible substrate 10 shown in FIG. That is, as shown in FIGS. 31 and 32, the flexible substrate 10 has a skew shape in which the connection terminals 3a and 3b connect the conductor patterns 3 adjacent to each other, that is, the one-turn coils. In other words, in the flexible substrate 10, the connection terminals x 2, x 3, y 3, y 4, etc. (with the exception of the connection terminals x 6, x 7, y 2) in the flexible substrate 10 shown in FIG. The exceptional connection terminals x6, x7, and y2 are linear connection terminals that connect between the conductor patterns 3 on the front surface and the back surface. The connection terminal 3a, which is a flying lead, has a skewed shape that is bent once in a boomerang shape, and the connection terminal 3a supported on the flexible substrate 2 is bent twice in a crank shape and ends. It has a skew shape.

  Each of the conductor patterns 3 of the present embodiment transfers to the adjacent conductor pattern 3 at the end of the conductor pattern 3, that is, at the positions of the connection terminals 3a and 3b. Therefore, these conductor patterns 3 are linear except for the portions where the pattern interval and the pattern shape in the regions B and D of the flexible substrate 10 change and the portions of the connecting terminals 3a and 3b at both ends. That is, the conductor pattern 3 of this embodiment does not have a crank-shaped pattern that exists between both ends of the above-described conductor pattern 3 of FIG.

  The electrical wiring from the terminal 1a to the terminal 1b through each conductor pattern 3 is the same as in the case of FIG. 33 (a), 33 (b), 34 (a), and 34 (b) show the connection portion 30 between the one-turn coils on the front and back of the flexible substrate 10. FIG. These figures correspond to FIGS. 26, 27 (a) and 27 (b) described above. FIGS. 35 (a) and 35 (b) and FIGS. 33 (a) and 33 (b) show the electrical connection between the one-turn coils on the surface of the flexible substrate 10 and the connection portion 30 between the one-turn coils on the back surface. . The boomerang-shaped connection terminal 3a (for example, the connection terminal x4) is superimposed on the crank-shaped connection terminal 3b (for example, the connection terminal x5) and is electrically connected by the solder 31 or the like. These figures correspond to FIGS. 28 (a) and 28 (b) described above. Note that the flexible substrate 10 of the present embodiment has the same structure, that is, a front / back symmetry structure, even if it is turned upside down.

  According to the toroidal coil 1 of the present embodiment, as shown in FIG. 31, the conductor pattern 3 can be uniformly arranged over the entire surface in the toroidal direction TD on both surfaces of the flexible substrate 10. That is, according to the present embodiment, in the flexible substrate 10 shown in FIG. 23 described above, the conductor patterns 3 on both the front and back surfaces in the toroidal direction (vertical direction in the figure) are missing and non-uniform. Can be improved. Moreover, the pattern between the both ends of each conductor pattern 3 can be made into a simple shape, and the symmetry of the toroidal coil 1 can be improved. According to this embodiment, compared to the case of FIG. 23, the conductor pattern 3 does not come off along the toroidal direction TD of the toroidal coil 1, and the toroidal coil 1 has a high noise canceling effect on the external magnetic field. A current sensor can be realized.

  36 and 37 show still another embodiment. In this embodiment, as shown in FIGS. 36 (a) and 36 (b), a conductive substrate having the above-described skew-shaped connection terminals 3a and 3b on a flexible substrate 10 having a multilayer (four layers in this example) wiring layer. The body pattern 3 is formed. At the end of the flexible substrate 10, a connection terminal 3 a which is a boomerang-shaped flying lead, a crank-shaped connection terminal 3 b, a boomerang-shaped connection terminal 3 b, and a crank-shaped connection terminal 3 b are arranged stepwise in order. Has been. This flexible substrate 10 has a front-back symmetrical structure that is the same structure even when turned upside down. Each of the connection terminals 3a and 3b is overlapped with each other as shown in FIGS. 37 (a), (b), and (c), and is electrically connected with solder 31 or the like as shown in FIG. 37 (d).

  38 (a) and 38 (b) show a toroidal coil device 1A according to still another embodiment. A toroidal coil device 1 </ b> A shown in FIG. 38A includes a conductor 101 for electromagnetic shielding that surrounds the toroidal coil 1. The conductor 101 is electrically insulated from the conductor pattern 3 and is, for example, an electrically floating potential. For example, when the toroidal coil device 1A is used as a sensor that measures an alternating current flowing through the electric wire 9, the conductor 101 shields a high-frequency magnetic field that becomes noise generated by the adjacent electric wire 9x outside the toroidal coil device 1A. For example, when a pulsed current noise is applied to the electric wire 9x and a high-frequency magnetic field is generated, the conductor 101 generates a vortex-induced current in the conductor due to the electromagnetic induction effect, and shields the high-frequency magnetic field by eddy current loss. . The toroidal coil device 1 </ b> A can accurately measure the current flowing through the measurement target electric wire 9 by reducing the influence of the external magnetic field by the conductor 101.

  A toroidal coil device 1 </ b> A shown in FIG. 38 (b) includes a magnetic body 102 for magnetic shielding that surrounds the toroidal coil 1. The magnetic body 102 is made of a material having high magnetic permeability (for example, nickel). The magnetic body 102 shields an external magnetic field generated by an alternating current flowing through the electric wire 9x adjacent to the toroidal coil device 1A. The toroidal coil device 1A can accurately measure the current flowing through the measurement target electric wire 9 by shielding an external magnetic field. The electromagnetic shield conductor 101 and the magnetic shield magnetic body 102 may be used in combination. Moreover, these can be comprised by the divided | segmented several components, and can be comprised so that opening and closing is possible similarly to the core 4 and case 5 of the toroidal coil apparatus 1A in FIG. 18 mentioned above, and it uses in combination with these. be able to.

  39 to 41 show a current measuring device 1B according to still another embodiment. As shown in FIGS. 39 (a) and 39 (b), the current measuring device 1B according to the present embodiment has a structure in which the electric wire 9x that generates a magnetic field that becomes noise is kept away from the toroidal coil 1 so as not to approach a predetermined distance or less. A case 5 is provided. This current measuring device 1B is used as a device for measuring an alternating current flowing through the electric wire 9. A circuit board 6 connected to the toroidal coil 1 is housed in a case 5 of the toroidal coil device 1A. The circuit board 6 has an IC that processes the output from the toroidal coil 1, and is connected to the toroidal coil 1 by connection wiring 61. The connection wiring 61 constitutes a twisted pair wire so as to cancel common mode noise. The case 5 secures a space so that the adjacent electric wire 9x is away from the toroidal coil 1 by a distance L1 or more and from the connection wiring 61 by a distance L2 or more. The distances L1 and L2 are set based on the generation state of the magnetic field that becomes noise due to the electric wire 9x and the current measurement accuracy required as the current measuring device.

  40A and 40B show the configuration of the case 5 in consideration of the influence of the electric wire 9x on the circuit board 6. FIG. Since the circuit board 6 usually has a two-dimensional wiring along the board surface, it can be considered that a coil that causes electromagnetic induction exists in the board surface. The magnetic field in the direction orthogonal to the circuit board 6 induces noise in the electric circuit in the circuit board 6 due to the coil parasitic on such wiring. For example, in FIGS. 41 (a) and 41 (b), the influence of the disturbance magnetic field Hx that becomes noise on the current measurement is greater in the case of FIG. 41 (a) than in the case of FIG. 41 (b). In any case, as shown in FIGS. 40 (a) and 40 (b), the external structure of the case 5 is set according to the arrangement and shape of the circuit board 6, and the external electric wire 9x is connected to the circuit board 6. By moving away, the influence of the disturbance magnetic field Hx can be reduced.

  FIG. 42 shows still another embodiment. In the toroidal coil 1 of this embodiment, each of the one-turn coils CL is arranged at a constant interval along the toroidal direction TD. In other words, each one-turn coil CL is formed by the conductor pattern 3, and each conductor pattern 3 is arranged at regular intervals along the circumferential toroidal direction TD. In any cross section orthogonal to the central axis AX of the toroidal coil 1, each of the conductor patterns 3 exists on the circumference at regular intervals.

  The above-described constant interval differs between the inner circumferential side interval p1 and the outer circumferential side interval p2 of the toroidal coil 1 (p1 ≦ p2), and generally differs when the cross-sectional position is different. Here, the intervals p1 and p2 are defined by the distance between the center positions of the widths of the respective conductor patterns 3, for example. In addition, the center of the width of each conductor pattern 3 will appear at a different position if the cross-sectional position is different due to the presence of a crank-like pattern and connection terminals for connecting each one-turn coil CL, The interval on the circumference in each cross section is constant.

  In addition to FIG. 42, as shown in FIG. 43, in the flexible substrate 10 (toroidal coil 1) of the present embodiment, each one-turn coil CL is disposed in a plane PL including the central axis AX. The conductor pattern 3 constituting each one-turn coil CL is located in the plane PL except for a transition pattern 3c which is a crank-shaped pattern for connecting the one-turn coils. When one 1-turn coil CL on the flexible substrate 10 is viewed from the position of the central axis AX, the conductor pattern 3 on the inner side and the conductor pattern 3 on the outer side of the one-turn coil CL appear to overlap each other.

  Further, the number of one-turn coils CL, and hence the number of conductor patterns 3 may be an odd number. However, as shown in FIG. 43, in the case of an even number, two one-turn coils CL exist in the plane PL. It is more preferable in terms of symmetry than in the case of an odd number. Furthermore, the configuration in which each of the one-turn coils CL is arranged at a constant interval along the toroidal direction TD or arranged in the plane PL including the central axis AX is a toroidal using the multilayer flexible substrate 10. It can also be applied to the coil 1. In this case, the conductor patterns 3 and the one-turn coil CL formed on both surfaces or a plurality of conductor layers are arranged at regular intervals for each conductor layer in the flexible substrate 10 or include the central axis AX. What is necessary is just to set it as the structure arrange | positioned in the plane PL.

  As described above, each of the one-turn coils CL is arranged at a constant interval along the toroidal direction TD, or arranged in the plane PL including the central axis AX. The advantages will be described with reference to FIGS. 44 (a) and 44 (b) and FIGS. 45 (a) and 45 (b). 44A and 44B show a state in which the current of the electric wire 9 is measured by the current measuring device 1B using the toroidal coil 1. FIG. In a state where the electric wire 9 is inserted through the center position of the toroidal coil 1, a magnetic field H is generated by the current flowing through the electric wire 9, and the intensity change of the magnetic field H induces a voltage in each one-turn coil CL of the toroidal coil 1. The current is measured based on the voltage. The magnetic field H is generated in the toroidal direction TD in the same manner (in the same direction) with respect to each one-turn coil CL, whereby the function of the toroidal coil 1 is exhibited.

  Incidentally, as shown in FIGS. 45 (a) and 45 (b), the disturbance magnetic field Hx due to the electric wire 9x outside the toroidal coil 1 is in the same direction, for example, at a position K1 far from the electric wire 9x and a position K2 close to it. Therefore, it penetrates in the opposite direction to each one-turn coil CL. The magnetic field at the distant position K1 is weaker than the magnetic field at the position K2, but the number of one-turn coils (number of turns) through which the disturbance magnetic field Hx passes is larger than that at the position K2. As described above, the disturbance magnetic field Hx caused by the external electric wire 9x is originally a magnetic field having a property of canceling each other to some extent with respect to the toroidal coil 1. Therefore, by providing the toroidal coil 1 with the maximum symmetry, it is possible to suppress the influence of the disturbance magnetic field Hx to the minimum influence by using such a property of the disturbance magnetic field Hx. . In other words, the winding pattern of each one-turn coil is made uniform as shown in FIGS. 42 and 43, thereby reducing the influence of the external magnetic field Hx. it can.

  The present invention is not limited to the above-described configuration, and various modifications can be made. For example, the configurations of the above-described embodiments can be combined with each other. Further, instead of using the single flexible substrate 10 as the toroidal coil 1, for example, a plurality of flexible substrates 10 divided in the toroidal direction or poloidal direction may be used as the toroidal coil 1. In addition to the flexible substrate 10 itself having a multilayer structure, the flexible substrate 10 may be stacked in multiple layers, that is, the toroidal coil 1 may be formed in a nested state. The number of turns of the coil can be increased by multiplexing the flexible substrate 10.

  The core 4 is not limited to the one that supports the flexible substrate 10 from the inside to secure the symmetry of the toroidal coil 1, but the flexible substrate 10 is supported from the outside to secure the symmetry of the toroidal coil 1. It may be. For example, an external support is configured such that a toroid-like space is formed in a non-magnetic block having an arbitrary outer shape, the flexible substrate 10 is accommodated in the space, and is supported along the inner wall of the toroid-like space. May be. In this case, the case 5 described above can also be used as this external support. As a method of placing the flexible substrate 10 along the inner wall of the toroidal space, for example, a method in which the flexible substrate 10 is regarded as a tire and a stretchable inner tube is inserted therein is used. The flexible substrate 10 may be pressed against the inner wall by expanding the inner tube. A method of simply inserting a stuffing or foam into the flexible substrate 10 may be used.

DESCRIPTION OF SYMBOLS 1 Toroidal coil 1A Toroidal coil apparatus 1B Current measuring apparatus 10 Flexible board 101 Conductor for electromagnetic shield 102 Magnetic body for magnetic shield 2 Flexible base material 21 Cut 3 Conductor pattern 3a Connection terminal (flying lead structure)
3b connection terminal 32 protective resin 33 conductor layer xo, x1, x3, x5, x7, yo, y1, y3, y5 connection terminal xe, x2, x4, x6, ye, y2, y4, y6 connection terminal (flying lead structure )
4 Core (supporting member)
4a Concave (relief space)
5 Case 51 Substrate storage part 52 Bulkhead 6 Circuit board 9 Electric wire AX Central axis CL 1 turn coil PL Plane including central axis Sa Average gap

Claims (23)

A toroidal coil device having a toroidal coil,
The toroidal coil includes a toroidal flexible substrate having a sheet-like flexible base material and a plurality of conductor patterns parallel to each other supported by the flexible base material,
The flexible substrate is bent using a notch provided between the parallel conductor patterns and is changed from a flat plate shape to a toroid shape,
Each of the conductor patterns has a connection terminal for connecting each in series,
Each of the conductor patterns becomes a one-turn coil by the bending,
Each of the one-turn coils is formed into a multi-turn coil by connecting the connection terminals.   In the state where the flexible substrate is developed in a flat plate shape, the conductor pattern has a wider average gap between the conductor patterns arranged in parallel to each other on the inner peripheral side than on the outer peripheral side of the toroidal coil. The toroidal coil device according to claim 1.   The toroidal coil device according to claim 1, wherein the connection terminal has a flying lead structure in which the conductor pattern protrudes from an end portion of the flexible base material.   The toroidal coil device according to any one of claims 1 to 3, wherein the connection terminals connected to each other are protected by a resin.   The toroidal coil device according to any one of claims 1 to 4, wherein the connection terminal is disposed on a portion of the flexible substrate that is on an outer peripheral side of the toroidal coil.   The toroidal coil device according to any one of claims 1 to 5, wherein the conductor pattern is formed in multiple layers on the flexible base material.   The toroidal coil device according to any one of claims 1 to 6, wherein the flexible substrate has a conductor layer for electromagnetic shielding.   The toroidal coil according to any one of claims 1 to 7, further comprising an electromagnetic shield conductor surrounding the toroidal coil, wherein the conductor is electrically insulated from the conductor pattern. apparatus.   The toroidal coil device according to any one of claims 1 to 8, further comprising a magnetic body for magnetic shielding surrounding the toroidal coil.   10. The toroidal coil device according to claim 1, wherein each of the one-turn coils is arranged at a constant interval along the toroidal direction of the toroidal coil.   11. The toroidal coil device according to claim 1, wherein each of the one-turn coils is disposed in a plane including a central axis of the toroidal coil.   The toroidal coil device according to claim 11, wherein the connection terminal has an oblique shape that connects the one-turn coils adjacent to each other.   The toroidal coil device according to any one of claims 1 to 12, further comprising a toroidal core that supports the flexible substrate from an inner side of the toroidal shape.   The toroidal coil device according to claim 13, wherein the core is made of a heat-resistant material that can withstand a thermal load at a temperature of 260 ° C or higher and a time of 10 seconds or longer.   The toroidal according to any one of claims 13 to 14, wherein the core has a cut along a plane including a central axis thereof, and can be separated or opened / closed by the cut. Coil device.   The toroidal coil device according to claim 13 or 15, wherein the core has a clearance space for avoiding generation of stress due to contact with the connection terminal.   The toroidal coil device according to any one of claims 1 to 16, further comprising a toroidal case that houses the toroidal coil.   The case is characterized in that the flexible substrate is pressed and fixed to a member that supports the flexible substrate from the inside of the toroidal shape, from the outer surface side of the flexible substrate around the connection terminal. The toroidal coil device according to claim 17.   The toroidal coil device according to claim 17 or 18, wherein the case can be divided along a plane including a central axis thereof. A toroidal case for housing the toroidal coil;
The case, the flexible substrate, and the core are openable and closable so that they can enter the central axis side from the outer peripheral side thereof. The toroidal coil device described in 1.   21. The toroidal coil device according to claim 20, wherein the case has a partition wall for preventing the flexible substrate housed in the case from being exposed when the case is opened and closed.   The said case has a structure which prevents the electric wire which generate | occur | produces the magnetic field used as noise from the said toroidal coil below predetermined distance, The Claim 21 thru | or 21 characterized by the above-mentioned. Toroidal coil device. A toroidal coil device according to any one of claims 1 to 22,
A circuit board electrically connected to the toroidal coil,
The circuit board has a circuit for outputting a signal corresponding to a current flowing through an electric wire inserted through the toroidal coil.

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