JP6576753B2 - Coil bobbin, coil and transformer provided with the coil - Google Patents

Description

  The present invention relates to a coil bobbin used for manufacturing a coil having an adjustable winding number in which a first winding and a second winding having a smaller number of turns than the first winding are connected in series via a tap, The present invention relates to a coil in which a coil is wound around a coil bobbin and a transformer including the coil.

  Conventionally, as a coil bobbin used for a coil for a transformer, it is composed of a frame having a rectangular ring shape, and a winding is wound around a side surface on the outer peripheral side of the frame (hereinafter referred to as “outer peripheral side surface”). Coil bobbins in which concave grooves are formed have been proposed.

  For example, in FIG. 1 of Patent Document 1, as a coil bobbin for a primary coil, a cross-sectional shape of an inner peripheral side surface (hereinafter referred to as “inner peripheral side surface”) of a frame having a rectangular ring shape is semicircular. In addition, a coil bobbin has been proposed in which a groove for winding winding having a U-shaped cross section is provided on the outer peripheral side surface.

JP 2001-203116 A

  In a coil bobbin composed of a frame with a semicircular cross section on the inner peripheral side, if the cross sectional shape of the winding winding groove formed on the outer peripheral side is made rectangular, the semicircular inner peripheral shape of the frame There is a problem in that the volume of the concave groove that can be formed in the frame body is limited, and the windings cannot be efficiently aligned and wound around the coil bobbin.

  For example, when the condition that the volume of the groove is maximized when the rectangular groove is formed on the outer peripheral side surface of the frame body is as follows.

As shown in FIG. 15, in the semicircular cross-sectional shape having a radius R ₁ of the frame 300, it is possible to form a concave groove 301 having a rectangular cross-sectional shape in a semicircular region AR having a radius R ₂ (<R ₁ ). . Rectangular cross-sectional shape of the groove 301, when changing the corners Q of the bottom side of the groove 301 is positioned on an arc of a radius R ₂ on the condition, the area S ₁ of the cross-sectional shape of the groove 301 When the length w of the upper and lower sides of the rectangle and the length d of the left and right sides are w: d = 2: 1, the maximum is obtained.

  This condition is that, in the rectangular cross-sectional shape of the concave groove 301, θ = 45 [when the angle between the line connecting the center position 0 on the upper side and the corner Q on the lower side and the upper side of the rectangle is θ [deg]. deg].

The ratio k = (S ₁ / S ₀ ) × 100 [%] with respect to the area S ₀ of the cross-sectional shape of the region AR when the area S ₁ of the cross-sectional shape of the concave groove 301 is maximum is S ₀ = (π · R _{Since 2} ² ) / 2 and S ₁ = 2 × R ₂ ² , k = (2 / π) × 100≈63.7 [%]. Therefore, when the cross-sectional shape of the concave groove 301 is rectangular, the coil bobbin The winding efficiency of the winding cannot be increased to 64 [%] or more.

  Patent Document 1 discloses an inner coil bobbin 11 having a U-shaped cross-sectional shape of a concave groove around which an inner winding corresponding to a primary winding is wound. There is no disclosure of a technique related to the cross-sectional shape of the groove for increasing the winding efficiency of the winding as much as possible.

  In a coil bobbin for manufacturing a coil having an adjustable winding number in which a first winding and a second winding having a smaller number of turns than the first winding are connected in series via a tap, If the volume of the concave groove around which the second winding is wound is made as large as possible, and the first winding and the second winding are not aligned and wound in the concave groove without any gap, the coil bobbin Increases the size of the primary coil using the coil bobbin.

  When the primary coil is enlarged, the secondary coil is also enlarged, which hinders downsizing of the transformer and cost reduction.

  The present invention has been made in view of the above-described problems. The volume of the concave groove around which the first and second windings are wound in the coil bobbin is made as large as possible, and the space factor of the winding in the coil bobbin is increased. An object of the present invention is to provide a coil bobbin having an improved height, a coil using the coil bobbin, and a transformer including the coil.

  The coil bobbin of the first invention has a shape in which the first winding is arranged concentrically outside the second winding having a smaller number of turns than the first winding, A coil bobbin used for forming a coil whose winding is adjustable and connected in series with a second winding via a tap, forming a frame, and a cross-sectional shape of a side surface on the inner peripheral side of the frame Is a semicircular shaped bobbin body, a first groove formed on the outer peripheral side surface of the frame for winding the first winding, and a bottom surface of the first groove A second groove for winding the second winding, the inner wall surface of the first groove facing the first groove is a second groove having a rectangular cross-sectional shape formed in the first groove. A coil bobbin characterized in that the opening is inclined with respect to the bottom surface so as to increase continuously or stepwise from the inner peripheral side to the outer peripheral side of the frame. A.

  The coil bobbin of the second invention is a coil bobbin characterized in that the inclination angle with respect to the bottom surface of the inner wall surface is 120 ± α ° (α: error within an allowable range).

  The coil bobbin according to the third aspect of the present invention is different from the second aspect in that at least one step is provided on the opposite inner wall surface, and the wall surface of each step is 120 ± α ° (α: within an allowable range) with respect to the bottom surface. The coil bobbin is characterized by being inclined at an inclination angle of (error).

  A coil according to a fourth invention is a coil used as a primary coil of a stationary induction device, and is formed by winding a winding in a layered manner in a concave groove of a coil bobbin according to any one of the first to third inventions. This is a feature coil.

  A transformer according to a sixth aspect of the invention is a transformer including the coil according to the fourth aspect of the invention as a primary coil.

  According to the coil bobbin or the like according to the present invention, the inner wall surface of the first groove where the first winding is wound faces the opening of the first groove from the inner peripheral side to the outer peripheral side of the frame body. Therefore, the volume of the first groove in the frame can be increased as much as possible.

  Thereby, the winding efficiency of the 1st, 2nd winding in a coil bobbin can be made high, and size reduction and cost reduction of a transformer using a coil bobbin and a coil bobbin can be aimed at.

The perspective view which shows the structure of the principal part of the transformer which concerns on this invention Diagram showing the circuit configuration of the transformer A front view of a first coil bobbin (coil bobbin according to the present invention) for producing a primary coil of the transformer The first coil bobbin is viewed from the right side XX sectional view in FIG. 4 of the first coil bobbin. The figure which shows the guide groove for guiding the alignment winding of the coil | winding for winding number adjustment formed in the bottom face of the 2nd recessed groove of the said 1st coil bobbin. The figure for demonstrating the conditions where an area becomes the maximum when the cross-sectional shape of the groove | channel for primary windings formed in the said 1st coil bobbin is made into a rectangle The figure for demonstrating the inclination-angle with respect to the bottom face of the inner wall face of the 1st ditch | groove of the 1st coil bobbin. The figure which shows the winding method of the main coil | winding to the concave groove of the said 1st coil bobbin, and the coil | winding for winding number adjustment A front view of the second coil bobbin for manufacturing the secondary coil of the transformer The second coil bobbin is viewed from the right side Sectional view taken along line YY in FIG. 10 of the second coil bobbin. The figure for explaining the manufacturing method of the coil part of the same transformer The figure which shows the modification of the cross-sectional shape of the ditch | groove formed in the 1st coil bobbin The figure for demonstrating the shape which maximizes the space factor of a coil | winding when the cross-sectional shape of the ditch | groove for winding a coil | wind is made rectangular.

  Embodiments of a coil bobbin according to the present invention will be described below with reference to the drawings.

  In the following description, a coil bobbin used for the primary coil and the secondary coil of the transformer will be described. In the transformer according to the present embodiment, the secondary coil in which the secondary winding is aligned and wound is arranged concentrically outside the primary coil in which the primary winding is aligned and the cylindrical shape is formed outside the legs of both coils. It has a structure in which the iron core is arranged. The coil bobbin according to the present invention is particularly used for producing a primary coil of a transformer.

  FIG. 1 is a perspective view showing a configuration of a main part of a transformer according to the present invention. FIG. 2 is a diagram showing a circuit configuration of the transformer.

  A transformer A shown in FIG. 1 includes a coil portion B having a rectangular ring shape in which a second coil 2 is disposed concentrically outside a first coil 1 (not visible in FIG. 1; see FIG. 13). And a cylindrical iron core C attached to one of the two long side portions (leg portions) of the coil portion B. As will be described later, the first coil 1 and the second coil 2 are manufactured using a coil bobbin 101 (see FIGS. 3 and 4) and a coil bobbin 201 (see FIGS. 10 and 11), respectively.

  In the transformer A, a high voltage of 6000 [V] or more is applied to the first coil 1 from the power system, and a prescribed low voltage (for example, 100 [V] or 200 [V] is supplied to the consumer from the second coil 2. ] Is an example applied to a distribution transformer.

  In the transformer A, since a high voltage is input to the first coil 1 and a low voltage is output from the second coil 2, the first coil 1 of the transformer A becomes a primary coil and the second coil 2 becomes two. The next coil. Further, the first coil 1 of the transformer A is a high voltage coil, and the second coil 2 is a low voltage coil.

  The transformer A corresponds to a portion indicated by a dotted line in the circuit configuration of the transformer A shown in FIG. In the following description, the first coil 1 is referred to as “primary coil 1” or “high voltage coil 1”, and the second coil 2 is referred to as “secondary coil 2” or “low voltage coil 1”.

Since the transformer A is a step-down transformer, the number of turns n ₂ of the secondary winding 202 of the secondary coil (low voltage coil) ₂ is larger than the number of turns n ₁ of the primary winding 102 of the primary coil (high voltage coil) 1. Few. Since the primary current flowing through the primary coil (high voltage coil) 1 is smaller than the secondary current flowing through the secondary coil (low voltage coil) 2, the wire diameter of the primary winding 102 is larger than the wire diameter of the secondary winding 202. small.

As shown in FIG. 2, the primary coil 1 of the transformer A includes a main winding 1021 that constitutes a main part of the number of turns n ₁ of the primary winding 102, and a winding adjustment part (the number of turns n ₁ of the primary winding 102 ( having a number of turns adjusting winding 1022 which constitutes a part) for adjusting the number of turns of turns n _1. The winding number adjusting winding 1022 has three small windings 1022a, 1022b, and 1022c. The main winding 1021 corresponds to the first winding according to the present invention, and the winding number adjusting winding 1022 corresponds to the second winding according to the present invention.

  In the circuit configuration of the transformer A, the three small windings 1022a, 1022b, and 1022c are connected in series, and the small winding 1022c of the winding number adjusting winding 1022 and the main winding 1021 are connected in series. The connection points of the small winding 1022a and the small winding 1022b, the small winding 1022b and the small winding 1022c, the small winding 1022c and the main winding 1021, and the open terminals of the small winding 1022a become taps.

  The circuit configuration of the transformer A shown in FIG. 2 is required for the bushing disposed in the tank and the tap changer TL built in the tank. The electrical connection is completed.

The tank, the primary voltage _{v 1} pair of primary bushing BS1 for applying a (+), BS1 (-) and secondary voltage _{v 2} 3 pieces of secondary bushing BS2 for outputting (+), BS2 ( -) ₂ , BS2 (G) ((G) indicates a grounded bushing) is provided. The common terminal _Pc of the tap changer TL is connected to the primary bushing BS1 (+).

The tap changer TL is provided with four tap terminals P _{1 to} P ₄ and a common terminal P _c connected to any one of the tap terminals by the switching piece TC. The common terminal _Pc of the tap changer TL is connected to the primary bushing BS1 (+). Ends of Komaki line 1022a is connected to the tap terminal P ₁ and the tap terminal _{P 2} respectively, at both ends of Komaki line 1022b is connected to the tap terminal _{P 2} and the tap terminal _{P 3} respectively, opposite ends of Komaki line 1022c are respectively It is connected to the tap terminals _{P 3} and the tap terminal _{P 4.} Both ends of the main winding 1021 tap terminal _{P 4} and the primary bushing BS1 respectively - are connected to the ().

In FIG. 2, connection points T _{1 to} T ₅ are illustrated in order to indicate connection points between the main winding 1021 and the winding number adjustment winding 1022. Thus, in FIG. 2, to connect the two ends of the small roll line 1022a to each connection point _{T 1} and the connection point _{T 2,} and connecting both ends of the small roll line 1022b to each connection point _{T 2} and the connection point _{T 3,} Komaki connecting the two ends of the line 1022c to the connection point _{T 4} respectively connecting point _{T 3.} Also, connecting the two ends of the primary winding 1021 to the connection point _{T 5} respectively connecting point _{T 4.}

  As shown in FIG. 1, both ends of the main winding 1021 and both ends of the small windings 1022a, 1022b, and 1022c are drawn out from the coil portion B of the transformer A. Further, as shown in FIG. 13, both end portions of the secondary winding 202 and the intermediate position c are also drawn from the coil portion B of the transformer A1. In FIG. 1, both end portions of the secondary winding 202 drawn from the coil portion B and the portion at the intermediate position c are not visible.

The lead lines L _a1 and L _a2 shown in FIG. 1 are lines drawn from both ends of the small winding 1022a, and the lead lines L _b1 and L _b2 are lines drawn from both ends of the small winding 1022b, The lead lines L _c1 and L _c2 are lines drawn from both ends of the small winding 1022c. Lead lines L _d1 and L _d2 are lines drawn from both ends of the main winding 1021, and lead lines L _e1 and L _e2 shown in FIG. 12 are lines drawn from both ends of the secondary winding 202. The lead line L _e3 is a line drawn from the intermediate position c of the secondary winding 202.

When the transformer A is housed in the tank, the lead wires L _a1 , L _a2 , L _b1 , L _b2 , L _c1 , drawn from the three small windings 1022 a, 1022 b, 1022 c of the winding number adjustment winding 1022, L _c2 is lead lines _{L a1, L a2} is the tap terminals _{P 1} and the tap terminal _{P 2} of the tap changer TL, lead lines _{L b1, L b2} taps of the tap changer TL terminal _{P 2} and the tap terminal _{P 3} The lead lines L _c1 and L _c2 are connected to the tap terminal P ₃ and the tap terminal P ₄ of the tap switch TL, respectively.

Further, the lead wire _{L d1} of one drawn from the main winding 1021 is connected to the connection point _{T 4} the tap changer TL, the other lead wire _{L d2} drawn from the main winding 1021, primary bushing BS1 Connected to (-). Lead lines L _e1 , L _e2 , and L _e3 drawn from the secondary coil 2 are connected to the primary bushing BS1 (+), the secondary bushing BS2 (−), and the secondary bushing BS2 (G), respectively.

In the transformer A, the number of turns n ₁ of the primary winding 102 can be switched in four stages by switching the tap terminals P _{1 to} P ₄ connected to the common terminal P _c with the tap switch TL. Three Komaki lines 1021a, 1021b, the respectively _n a number of turns of the _1021c, n b, and _{n c,} the number of turns of the primary winding 1021 and _{n d,} the number of turns _{n 1} of the primary winding 102, _{(n a + n b + n c + n} d), (n b + n c + n d), can be switched to four kinds of _{(n c + n d),} n d.

  In the following description, a case where the transformer A according to the present embodiment is applied to a 6600 [V] / (210-105 [V] transformer for power distribution will be described.

6600 [V] / (210-105) [V] Since the primary voltage input to the primary coil of the transformer largely fluctuates depending on the distance from the distribution substation in the vicinity of the customer where the transformer is disposed, From the distribution substation, power is transmitted at a voltage higher than 6600 [V]. Therefore, the primary voltage v ₁ input to the primary coil 1 of the transformer A has a high voltage of 6600 [V] or more at a location near the distribution substation, and is 6600 [V] or less at a location far from the distribution substation. May be high pressure.

The transformer A according to the present embodiment adjusts the number of turns of the primary coil 1 in four stages according to the magnitude of the primary voltage v ₁ , and stabilizes the secondary voltage of (210-105) [V] from the secondary coil 2. v ₂ can be output. Specifically, the primary voltage v ₁ is divided into four types of v _A , v _B , v _C , and v _D (v _A > v _B > v _C > v _D ), and four taps are associated with each voltage value. ing.

The transformation ratio of the transformer A is represented by (v ₁ / v ₂ ) = (n ₁ / n ₂ ). Since v ₂ and n ₂ are fixed, the number of turns n ₁ of the primary winding 102 is proportional to the primary voltage v ₁ . Therefore, the primary voltage v _A , v _B , v _C , v _D of each tap is added to the number of turns of the primary winding 102 (n _a + n _b + n _c + n _d ), (n _b + n _c + n _d ), (n _c + n _d ) and n _d correspond to each other.

The tap voltages v _A , v _B , v _C , and v _D are usually determined by standards, customer specifications, and the like. For example, when v _A = 6750 [V], v _B = 6600 [V], v _C = 6450 [V], and v _D = 6300 [V], v _A −v _B = v _B −v _C = _{v C -v} D = 150 because it is _[V], a _{n a = n b = n c} . That is, the number of turns of the three small windings 1022a, 1022b, and 1022c is the same.

  Next, the structure of the primary coil 1 and the secondary coil 2 is demonstrated. First, the structure of the primary coil 1 will be described with reference to FIGS.

In the following description, the case where the four tap voltages of the transformer A according to the present embodiment are set to 6750 [V], 6600 [V], 6450 [V], and 6300 [V] will be described as an example. In the example in this case, three Komaki lines 1022a, 1022b, the number of turns of 1022c and _{n s, v C / v D} = (n d + n s) / n d = from 6450/6300, primary winding 1021 the number of turns _{n d} and Komaki lines 1022a, 1022b, a relationship of _n d = 42 × _{n s} between the number of turns _{n s} of 1022c.

  3 is a front view of a coil bobbin 101 (coil bobbin according to the present invention) for manufacturing the primary coil 1 of the transformer A, FIG. 4 is a view of the coil bobbin 101 viewed from the right side, and FIG. FIG. 5 is a cross-sectional view of the coil bobbin 101 taken along line XX in FIG. 4.

  FIG. 6 is a view showing a guide groove 1016 for guiding the aligned winding of the winding number adjusting winding 1022 formed on the bottom surface 1014B of the second concave groove 1014. FIG. 7 shows a cross-sectional shape of the concave groove 1012. FIG. 8 is a diagram for explaining the condition that the area is maximized when it is rectangular, and FIG. 8 is a diagram for explaining the inclination angle θ of the inner wall surface 1013A of the first groove 1013 with respect to the bottom surface 1013B. FIG. 9 is a diagram for explaining a winding method of the main winding 1021 and the winding number adjusting winding 1022 in the concave groove 1012.

  In the following description, in order to distinguish the coil bobbin for manufacturing the primary coil 1 from the coil bobbin for manufacturing the secondary coil, the coil bobbin for the primary coil 1 is referred to as a “first coil bobbin” and used for the secondary coil 2. This coil bobbin is referred to as a “second coil bobbin”.

  3, the surface along the outer periphery of the ring shape is referred to as “outer peripheral side surface”, the surface along the inner periphery is referred to as “inner peripheral side surface”, and the left surface of the bobbin main body 1011 in FIG. In the description, the right side surface is referred to as the “rear surface”.

  The primary coil 1 is formed into a rectangular ring shape using a first coil bobbin 101. As shown in FIGS. 3 and 4, the first coil bobbin 101 includes a bobbin body 1011 having a short rectangular ring shape. The bobbin main body 1011 is manufactured by molding a resin.

  The bobbin main body 1011 is formed with a concave groove 1012 for winding the primary winding 102 (see FIG. 13) on the outer peripheral side surface, and the outer shape of the portion other than the outer peripheral side surface (the inner peripheral side surface portion of the bobbin main body 1011). The shape is shaped into a semicircular shape (see FIGS. 5 and 9).

  The reason why the outer shape of the inner peripheral side surface of the bobbin main body 1011 is semicircular is that a cylindrical iron core C is attached to one of the two long sides of the bobbin main body 1011 as shown in FIG. Therefore, the inner surface of the hole of the iron core C is in close contact with the bobbin main body 1011. Therefore, the radius of the part of the bobbin main body 1011 whose semicircular outer shape is set to a size slightly smaller than the radius of the hole in the iron core C.

  The concave groove 1012 formed on the outer peripheral side surface of the bobbin main body 1011 has a first concave groove 1013 around which the main winding 1021 is wound and a second concave groove 1014 around which the winding number adjusting winding 1022 is wound. . The second concave groove 1014 is formed in the center of the bottom surface 1013B of the first concave groove 1013 in the width direction (lateral direction in FIG. 4).

  The cross-sectional shape of the second groove 1014 taken along line XX in FIG. 4 (hereinafter, this shape is referred to as “cross-sectional shape”) is such that both inner wall surfaces 1014A have a bottom surface 1014B of the second groove 1014. It has a vertically rising shape (rectangular shape) (see FIG. 6). On the other hand, the cross-sectional shape of the first concave groove 1013 is such that both inner wall surfaces 1013A rise from the bottom surface 1013B of the first concave groove 1013 so as to incline outward at a predetermined inclination angle θ. (See FIGS. 5 and 8).

  The first coil bobbin 101 according to the present embodiment is characterized by the cross-sectional shape of the concave groove 1012. Details of the shape and size of the cross section of the concave groove 1012 will be described later.

  The rectangular external dimension (L1 (length in the longitudinal direction) × W1 (length in the short direction)) of the front side of the bobbin body 1011 is the rectangular external dimension (L2 (longitudinal direction) in the back side of the bobbin body 1011). (Length) × W2 (length in the short direction))). As shown in FIG. 13, the first coil bobbin 101 is inserted into the hole portion of the second coil bobbin 201, and the structure of the coil part B is arranged concentrically outside the primary coil 1. It is for making it the structure made.

  Therefore, the rectangular outer dimension (L1 × W1) on the front side of the bobbin main body 1011 is equal to the rectangular dimension (L3 (length in the longitudinal direction) × W3 (length in the short direction) of the hole portion of the second coil bobbin 201. S)) The size is set slightly smaller than (see FIG. 10). On the other hand, the rectangular outer dimension (L2 × W2) on the back side of the bobbin main body 1011 is equal to the outer dimension of the second coil bobbin 201 having a rectangular ring shape (L4 (longitudinal length) × W4 (short direction). The length is set to be approximately the same as the length)) (see FIG. 10).

  Of the side surface on the front side of the bobbin main body 1011, five notches 1015A, 1015B, 1015C, 1015D, and 1015E are provided on one long side portion (the long side portion on the right side in FIG. 3). Yes.

Notches 1015A is one of the lead wire _{L a1} of regular winding is the Komaki line 1022a of the second groove 1014 drawer outside of the bobbin main body 1011, notches 1015B is the Komaki line 1022a other The lead wire L _a2 and one lead wire L _b1 of the small winding 1022b are pulled out to the outside of the bobbin main body 1011, and the notch portion 1015C is one of the other lead wire L _b2 of the small winding 1022b and the small winding 1022c. This is for drawing out the lead line L _c1 to the outside of the bobbin main body 1011.

Further, the notch 1015D pulls out the other lead line L _c2 of the small winding 1022c and one lead line L _d1 of the main winding 1021 wound around the first concave groove 1013 to the outside of the bobbin main body 1011. The notch 1015E is for drawing out the other lead line L _d2 of the main winding 1021 wound around the first concave groove 1013 to the outside of the bobbin main body 1011. In the following description, the notch portion is referred to as a “winding lead portion”.

  The three winding lead portions 1015A, 1015B, and 1015C have a depth from the outer peripheral side surface of the bobbin main body 1011 to the bottom surface 1014B of the second concave groove 1014, and the second concave groove from the front side of the bobbin main body 1011. It is formed so as to penetrate to 1014 (see FIG. 5).

  The winding lead portion 1015D has a depth from the outer peripheral side surface of the bobbin main body 1011 to the bottom surface 1013B of the first concave groove 1013, and is formed so as to penetrate from the front side of the bobbin main body 1011 to the first concave groove 1013. Has been. The winding lead portion 1015E has a depth from the outer peripheral side surface of the bobbin main body 1011 to the upper end position of the inclined inner wall 1013A of the first concave groove 1013, and the first concave groove 1013 from the front side of the bobbin main body 1011. (See FIG. 5).

  In order to increase the cooling effect of the primary coil 1 by the winding lead portions 1015A to 1015E, the winding lead portion 1015D and the winding lead portion 1015E are connected to the bobbin main body 1011 as shown by the phantom line in FIG. It may have a depth from the outer peripheral side surface to the bottom surface 1014B of the second concave groove 1014, and may penetrate from the front side of the bobbin main body 1011 to the second concave groove 1014.

One end of Komaki line 1022a drawn from the winding draw-out portion 1015A of the bobbin main body 1011 corresponds to the lead line _{L a1} in FIG. 1, Komaki line drawn from the winding draw-out portion 1015B of the bobbin main body 1011 The other end portion of 1022a and one end portion of the small winding 1022b correspond to the lead lines L _a2 and L _b1 in FIG. 1, respectively, and the small winding 1022b drawn from the winding lead portion 1015C of the bobbin main body 1011. The other end and one end of the small winding 1022c correspond to the lead lines L _b2 and L _c1 in FIG.

The other end of the small winding 1022c drawn from the winding lead portion 1015D of the bobbin main body 1011 and one end of the main winding 1021 correspond to the lead lines L _c2 and L _d1 of FIG. The other end portion of the main winding 1021 drawn from the winding lead portion 1015E of 1011 corresponds to the lead line L _d2 of FIG.

  Next, the cross-sectional shape and size of the first groove 1013 and the second groove 1014 will be described. First, the cross-sectional shape and size of the second concave groove 1014 will be described.

The second groove 1014, three Komaki lines 1022a, 1022b, in order to only regular winding respectively turns _{n s} a 1022c, and has a rectangular cross-sectional shape. As shown in FIG. 6, the bottom surface 1014B of the four corners of the bobbin main body 1011 of the second concave groove 1014 (the portion where the bottom surface 1014B of the second concave groove 1014 bends at right angles) is wound around the bottom surface 1014B. A first guide groove 1016 is provided for guiding the winding position so that the small windings 1022a are aligned.

In the present embodiment, as shown in FIG. 9, the small winding 1022 a arranged at one end of the primary winding 102 is wound around the second concave groove 1014 of the first coil bobbin 101 in a two-layer structure. Turned. Komaki line 1022a is opposite from the inner wall surface 1014A of the second groove 1014 along the first guide groove 1016 of one of the lead wire _{L a1} from the winding draw-out portion 1015A in the state pulled out to the outside of the bobbin main body 1011 It is wound up to the inner wall surface 1014A on the side. Thereafter, the small winding 1022a is folded and wound on the upper side of the wound small winding 1022a to the original inner wall surface 1014A (the inner wall surface 1014A having the winding lead portion 1015A), and then the other lead line L _a2 is drawn out of the bobbin main body 1011 from the winding lead-out portion 1015B.

  The reason why the number of the small windings 1022a is two is that the both ends of the small winding 1022a can be pulled out from the bobbin main body 1011 in the same direction. Therefore, the number of the small windings 1022a may be an even number layer and is not limited to two layers.

  The first layer of the small winding 1022a is wound around the bottom surface 1014B of the second concave groove 1014 along the first guide groove 1016. The second layer of the small winding 1022a is formed on the upper surface of the first layer. The dents between the windings to be wound are wound as a guide (see FIGS. 6 and 9). When a coil having a rectangular cross-sectional shape is manufactured by winding windings in multiple layers, the first pattern and even layer turns that have the same number of turns in the even layer and odd layer are used as the winding pattern of windings. A second pattern is known in which the number is one turn less than the number of turns in the odd layer.

In this embodiment mode, the small windings 1022a are stacked in a first pattern. When the small winding 1022a is aligned and wound in two layers in the first pattern, the number of turns of each layer of the small winding 1022a is n _s / 2 [turns]. Assuming that the wire diameter is φ ₁ [mm], the dimension in the width direction of the winding wound in an aligned manner in each layer is φ ₁ × n _s / 2.

The first guide groove 1016, the cross-sectional shape having a φ _1/2 [mm] shorter groove width than is arcuate groove (see FIG. 6). The first guide grooves 1016 are formed with n _s / 2 [pieces] at a pitch of φ ₁ [mm] in the width direction of the bottom surface 1014B of the second concave groove 1014.

  Since the small winding 1022b of the winding adjustment winding 1022 has the same number of turns as that of the small winding 1022a, the winding is aligned in two layers in the same manner as the small winding 1022a above the second layer of the small winding 1022a. (See FIG. 9). Since the small winding 1022c of the winding adjustment winding 1022 has the same number of turns as the small winding 1022a, it is aligned and wound in two layers on the second layer above the small winding 1022b in the same manner as the small winding 1022a. (See FIG. 9).

Similarly to the small winding 1022a, the small windings 1022b and 1022c are aligned and wound in the first pattern, so that the dimension in the width direction of the windings aligned and wound in each layer is φ ₁ × n _s / 2. Yes. The regular winding of the first pattern, because the odd layer and even-numbered layers by phi _1/2 [mm] to each other position shifts, two-layer coiling Komaki line 1022a, the width direction of Komaki lines 1022b and Komaki line 1022c size becomes _{φ 1 × (n s / 2} ) + φ 1/2 = φ 1 × (n s +1) / 2 in.

Since the small winding 1022a, the small winding 1022b, and the small winding 1022c are wound around the second concave groove 1014 so as to be stacked with the same number of turns in the width direction, The surface shape is a rectangle in which both inner wall surfaces 1014A rise vertically to the bottom surface 1014B. Then, the width dimension _w 1 [mm] of the second groove 1014 (see FIG. 9) is set to _{φ 1 × (n s +1)} / 2.

In the second concave groove 1014, the winding number adjustment winding 1022 is wound so that the small windings 1022a, 1022b, and 1022c aligned and wound in three two layers are stacked in three stages (six layers). Therefore, the depth h ₁ [mm] of the depth of the second concave groove 1014 is approximately (the number of stacked layers −1) when the dimension of the overlapping portion of the windings of each layer is Δh ₁ [mm] (see FIG. 13). × (φ ₁ −Δh ₁ ) + φ ₁ = 5 × (φ ₁ −Δh ₁ ) + φ ₁ [mm] is set. In general, (φ ₁ −Δh ₁ ) can be set to 0.866 × φ _1, and therefore the depth dimension h ₁ of the second groove 1014 is set to about 5.33 × φ ₁ [mm]. Has been.

  Next, the cross-sectional shape and size of the first concave groove 1013 will be described.

  The first concave groove 1013 has an isosceles trapezoidal cross section in which the length of the upper base is longer than the length of the lower base, and the inner angles of both ends of the lower base are 120 ± α ° (α: error within an allowable range). It has a shape. That is, both the inner wall surfaces 1013A of the first groove 1013 are inclined with respect to the bottom surface 1013B so that the opening of the first groove 1013 becomes wider from the inner peripheral side surface of the bobbin main body 1011 toward the outer peripheral side surface. Inclined at 120 ± α °.

As shown in FIG. 7A, the radius of the semicircular cross-sectional shape of the inner peripheral side surface of the first coil bobbin 101 is R ₁ [mm], and the predetermined length D is larger than the radius R ₁ of the first coil bobbin 101. It is assumed that the groove 1012 can be formed in a region AR (region indicated by a one-dot chain line) having a radius R ₂ (<R ₁ ) that is as short as possible.

  The reason why the cross-sectional shape of the first concave groove 1013 is an isosceles trapezoidal shape is to make the space factor η of the primary winding 102 in the first coil bobbin 101 as high as possible.

When the concave groove 1012 is formed in the area AR, the cross-sectional shape of the concave groove 1012 corresponds to the coil cross section of the primary coil 1 of the primary winding 102 aligned and wound around the concave groove 1012. area of the cross-sectional shape (hereinafter, simply referred to as "area".) as the S _1, and the area of the cross-sectional shape of the primary coil 1 and S _L, the space factor of the primary coil 1 in the groove 1012 and eta ₁ The space factor η ₁ is represented by η ₁ = S _L / S ₁ . When the ratio (S ₁ / S ₀ ) of the area S ₁ of the groove 1012 in the area S ₀ of the area AR is η ₂ , the space factor η of the primary winding 102 in the area AR is η = S _L / S ₀ = (S _L / S ₁ ) × (S ₁ / S ₀ ) = η ₁ × η ₂

Therefore, in the present embodiment, the space factor of the primary winding 102 in the first coil bobbin 101 is set so that the primary winding 102 corresponds to the area S ₀ of the area AR when the primary winding 102 is aligned and wound in the area AR. The area S _L is defined by the ratio η.

For example, when the coil cross-sectional shape is rectangular, it is known that the space factor, which is the ratio of the cross-sectional area of the wound windings with respect to the coil cross-sectional area, can be 85% or more. According to this, since the space factor η ₁ can be assumed to be a fixed value of 85% or more when the primary winding 102 is aligned and wound in the concave groove 1012 having a rectangular cross section, the space factor η is In order to make it as high as possible, the cross-sectional shape of the concave groove 1012 in the region AR may be designed so that the ratio η ₂ is as high as possible.

  For example, when the cross-sectional shape of the groove 1012 is rectangular, in order to maximize the space factor η, as described with reference to FIG. 15, the length (width dimension) w of the upper and lower sides of the rectangle The length (depth dimension) d of the left and right sides may satisfy the condition of w: d = 2: 1.

In the present embodiment, since the second concave groove 1014 is formed on the bottom surface of the first concave groove 1013, the cross-sectional shape of the concave groove 1012 is not exactly rectangular. However, the number of turns 3n _s turns regulating winding ₁₀₂₂ from n d = 42 × _{n s,} because it is 1/14 (7% approximately) with respect to the number of turns _{n d} of the main windings 1021, the area of the groove 1012 Of S ₁ , the area of the first groove 1013 is dominant.

  Accordingly, when the cross-sectional shape of the first concave groove 1013 is a rectangle, when the width dimension w and the depth dimension d of the rectangle satisfy w: d = 2: 1, the occupation of the primary winding 102 in the area AR It can be considered that the product factor η is maximized.

  FIG. 7B is a diagram showing a cross-sectional shape of the concave groove 1012 when the cross-sectional shape of the first concave groove 1013 is a rectangle in which the width dimension w and the depth dimension d satisfy w: d = 2: 1. It is. As shown in the figure, when the cross-sectional shape of the first groove 1013 is rectangular, both sides of the first groove 1013 and the lower part of the bottom surface of the second groove 1014 (FIG. 7 ( A dead space is formed in the part (b) indicated by hatching, and the space factor η cannot be sufficiently increased.

In FIG. 7B, the area S ₀ of the region AR is S ₀ = (π × R ₂ ² ) / 2, the area S _A of the first groove 1013 is S _A = R ₂ ² , area _{S B} of the groove 1014, since it is ^{_{S B ≒ R 2 2/14}} , η 2 = [(15/14) × R 2 2] / ((π × R 2 2) / 2) = (1 + 1 /14)/(π/2)≈0.68 (68%). Therefore, when the cross-sectional shape of the first concave groove 1013 is rectangular, it is difficult to increase the space factor η of the primary winding 102 in the first coil bobbin 101 to 70% or more.

  In the present embodiment, the space of the primary winding 102 in the first coil bobbin 101 is obtained by inclining both inner wall surfaces 1013A of the first groove 1013 with respect to the bottom surface 1013B at an inclination angle θ = 120 ± α °. The rate η is set to 70% or more.

  The inclination angle θ with respect to the bottom surface 1013B of both inner wall surfaces 1013A of the first groove 1013 is 120 ± α °, as shown in FIG. This is to prevent a gap from occurring between 1013A.

  The main winding 1021 aligned and wound in layers is aligned and wound with the upper layer winding as a guide by using the depression of the lower aligned winding as a guide, so that the windings and inner wall surfaces of each layer are formed on both inner wall surfaces 1013A. In order to prevent a gap from being generated between 1013A, the inner wall surface 1013A may be aligned with the tangent of the winding located at the end of each layer.

As shown in FIG. 8, the winding positioned at the end of the lower aligned winding and the winding positioned at the end of the upper aligned winding are shifted from each other by φ _1/2 in the width direction. The tangent of the winding located at the end is inclined at 120 ± α ° with respect to the bottom surface 1013B.

  The cross-sectional shape of the concave groove 1012 shown in FIG. 5 is such that both inner wall surfaces 1013A of the first concave groove 1013 are outward with respect to the bottom surface 1013B with respect to the cross-sectional shape of the concave groove 1012 shown in FIG. Inclined at an inclination angle θ = 120 ± α °. In FIG. 5, the inclined sides corresponding to both inner wall surfaces 1013A of the cross-sectional shape of the first concave groove 1013 are up to the position M intersecting with the arc line indicating the area AR, and above the position M. The part is a vertical side.

As shown in FIG. 9, the main winding 1021 is connected to the second lead wire L _d1 from the inner wall surface 1013A of the first groove 1013 with the second lead wire L _d1 drawn out from the winding lead portion 1015D to the outside of the bobbin main body 1011. It is wound along the guide groove 1017. When the main winding 1021 is wound up to the inner wall surface 1013A on which the winding lead portion 1015E is formed, the main winding 1021 is folded and is a depression between the windings formed on the upper side of the first-layer main winding 1021 that is aligned and wound. To the original inner wall surface 1013A (inner wall surface 1014A having the winding lead portion 1015D). After that, the main winding 1021 is folded each time it reaches the inner wall surface 1013A with a depression between the windings formed on the upper side of the main winding 1021 of each layer wound in an aligned manner as a guide. The other lead wire L _d2 is drawn out of the bobbin main body 1011 from the winding lead portion 1015E.

Since both inner wall surfaces 1013A of the first concave groove 1013 are inclined outward at an inclination angle θ = 120 ± α ° with respect to the bottom surface 1013B, the first concave groove is formed in the portion where both inner wall surfaces 1013A are inclined. The number of turns of each layer of the main winding 1021 aligned and wound in layers in 1013 is the number of turns in the upper layer relative to the number of turns N _{k in the} lower layer (k is the number of the layer, k = 1, 2, 3,... M). The number N _{k + 1} satisfies the relationship N _{k + 1} = N _k +1. Further, in the portion where both inner wall surfaces 1013A are vertical, the number of turns of each layer of the main winding 1021 is all (N _m1 +1).

The number of layers and the number of turns in the portion where both inner wall surfaces 1013A of the first concave groove 1013 are inclined are m ₁ and n _d1, and the number of layers and the number of turns in the portion where both inner wall surfaces 1013A are vertical are m ₂ and n _d2 . Then, n _d1 = N ₁ + N ₂ +... + N _m1 = N ₁ + (N ₁ +1) +... + (N ₁ + m ₁ −1) = m ₁ × N ₁ + (m ₁ −1) (where N 1 _{Since 1} > n _s / 2) and n _d2 = (N _m1 +1) × m ₂ = (N ₁ + m ₁ ) × m ₂ , the number of turns n _d of the first groove 1013 is n _d = n _d1 + n _d2 = m ₁ × N ₁ + (m ₁ −1) + (N ₁ + m ₁ ) × m ₂ = (m ₁ + m ₂ ) × N ₁ + m ₁ × (m ₂ +1) −1 .

In the example of FIG. 5, the area S _A of the first groove 1013 _'is increased by the area S _C of the portion indicated by oblique lines shown in FIG. 7 (b) than the case shown in FIG. 7 (b). The area _{S C} is approximately 28.3% of the rectangular area _{S A} of the first groove 1013 illustrated in FIG. 7 (b). Therefore, the area _{S A} of the first groove 1013, since the approximately 1.28 times in the case of the cross-sectional shape of the first groove 1013 in a rectangular, groove 1012 to the area _{S 0} of the region AR The ratio η ₂ of the area S ₁ is η ₂ = (1.28 + 1/14) / (π / 2) ≈0.862 (approximately 86.2%).

For example, in the present embodiment, when the space factor η ₁ of the main winding 1021 and the turn adjustment winding 1022 in the concave groove 1012 is 0.85, the space factor η of the primary winding 102 in the first coil bobbin 101 is Can be set to 0.85 × 0.862≈0.73 (approximately 73%).

  Similarly to the bottom surface 1014B of the second concave groove 1014, the main winding 1021 wound around the first concave groove 1013 is aligned with the bottom surface 1013B of the four corners of the bobbin main body 1011 of the first concave groove 1013. A second guide groove 1017 for guiding the winding position is provided.

The second guide groove 1017 is a groove having an arcuate cross-sectional shape that is the same size as the first guide groove 1016. Similarly to the first guide groove 1016, the second guide groove 1017 is formed in the bottom surface 1013B of the first concave groove 1013 at a pitch of φ ₁ [mm] in the width direction (see FIG. 8).

Since the main winding 1021 is aligned and wound in the (m ₁ + m ₂ ) layer in the first concave groove 1013, the depth dimension h ₂ [mm] of the first concave groove 1013 (see FIG. 9) is When the dimension of the overlapping portion of each layer is Δh [mm], it is set to approximately (m ₁ + m ₂ −1) × (φ ₁ −Δh) + φ ₁ [mm].

  In the first coil bobbin 101 according to the first embodiment, since the iron core C is wound around the left leg portion when viewed from the front, the winding lead-out portions 1015A to 1015A to the portion corresponding to the right leg portion when viewed from the front. 1015E is formed, but winding lead-out portions 1015A to 1015E may be formed in a portion corresponding to the left leg portion when viewed from the front, and the iron core C may be wound around the right leg portion when viewed from the front. .

  In the first coil bobbin 101 according to the first embodiment, the winding lead portions 1015A to 1015E are formed on the front side surface (left side surface), but the back side surface (right side surface). Winding lead-out portions 1015A to 1015E may be formed. That is, in FIG. 4, the winding lead portions 1015A to 1015E may be formed on the right side surface.

  Next, the structure of the secondary coil 2 will be described with reference to FIGS.

  FIG. 10 is a view of the second coil bobbin 201 for producing the secondary coil 2 of the transformer A as viewed from the front, FIG. 11 is a view of the second coil bobbin 201 as viewed from the right side, and FIG. FIG. 11 is a cross-sectional view of the second coil bobbin 201 taken along line YY in FIG.

  The secondary coil 2 is formed into a rectangular ring shape using the second coil bobbin 201. As shown in FIGS. 10 and 11, the second coil bobbin 201 includes a bobbin main body 2011 having a short rectangular ring shape. The bobbin body 2011 has a height dimension (dimension in the width direction in FIG. 12) that is substantially the same as the bobbin body 1011.

  The shape viewed from the side surface of the bobbin main body 2011 is substantially bilaterally symmetric. However, in the following, for convenience of explanation, in FIG. 10, the surface along the outer periphery of the ring shape is referred to as the “outer peripheral side surface” and extends along the inner periphery. The surface is referred to as an “inner peripheral side surface”, and in FIG. 11, the left surface of the bobbin main body 2011 is referred to as “front”, and the right surface is referred to as “rear surface”.

  The bobbin main body 2011 is formed with a concave groove 2012 for winding the secondary winding 202 (see FIG. 13) on the outer peripheral side surface, and the shape of the hole portion is formed in a rectangular parallelepiped shape (FIG. 10). FIG. 11). The reason why the shape of the hole portion of the bobbin main body 2011 is a rectangular parallelepiped shape is that the bobbin main body 1011 is fitted and attached to the hole portion as shown in FIG.

  The rectangular dimension (L3 (length in the longitudinal direction) × W3 (length in the short direction)) of the hole portion of the bobbin body 2011 is the rectangular outer dimension (L1 on the front side of the bobbin body 1011 as described above. × W1) is set slightly larger than the size. Further, the rectangular external dimensions (L4 (length in the longitudinal direction) × W4 (length in the short direction)) of the outer peripheral side surface of the bobbin main body 2011 are the rectangular external dimensions on the back side of the bobbin main body 1011 as described above. The dimension is set to be approximately the same as the dimension (L2 × W2).

  Of the ring-shaped side surface on the front side of the bobbin main body 2011, one notch portion 2013 is provided at the center portion of one long side (the long side portion on the left side in FIG. 10). The notch 1013 is for pulling out both ends of the secondary winding 202 wound around the concave groove 2012 and the intermediate position c to the outside of the bobbin main body 2011. In the following description, the notch portion of the bobbin main body 2011 is also referred to as “winding lead portion”.

The winding lead portion 2013 has a depth from the outer peripheral side surface of the bobbin main body 2011 to the bottom surface 2012B of the concave groove 2012, and is formed so as to penetrate from the front side of the bobbin main body 2011 to the concave groove 2012. Both end portions of the secondary winding 202 drawn out from the winding lead-out portion 2013 of the bobbin main body 2011 correspond to the above-described lead lines L _e1 and L _e2 in FIG.

  The concave groove 2012 has a shape (rectangular cross-sectional shape) in which both inner wall surfaces 2012A rise perpendicularly to the bottom surface 2012B of the concave groove 2012 (see FIG. 12). Winding positions are set so that the secondary winding 202 wound around the bottom surface 2014B is aligned with the bottom surface 2012B of the four corners of the bobbin main body 2011 of the concave groove 2012 (the portion where the bottom surface 2012B of the concave groove 2012 is bent at a right angle). A guide groove (not shown) for guiding is provided.

The secondary winding 202 is wound along the guide groove 2014 from the inner wall surface 2012 </ b> A of the concave groove 2012 in a state where one lead wire _{Le <b> 1} is drawn out of the bobbin main body 1011 from the winding lead portion 2013. When the secondary winding 202 is wound up to the inner wall surface 2012A on the opposite side, the secondary winding 202 is folded back, and a recess between the windings formed on the upper side of the aligned secondary winding 202 is used as a guide. To the inner wall surface 2012A (the inner wall surface 2012A having the winding lead portion 2013). Thereafter, the secondary winding 202 is folded each time it reaches the inner wall surface 2012A with a depression between the windings formed on the upper side of the secondary winding 202 of each layer that has been aligned aligned as a guide. The other lead wire _Le1 is drawn from the winding lead portion 2013 to the outside of the bobbin main body 2011.

The first layer of the secondary winding 202 is wound around the bottom surface 2012B of the concave groove 2012 along the guide groove 2014. The second layer of the secondary winding 202 is a winding formed on the top surface of the first layer. It can be wound with a hollow between each other as a guide. When the number of turns of each layer of the secondary winding 202 is n _t [turns] and the wire diameter of the winding used for the secondary winding 202 is φ ₂ (> φ ₁ ) [mm], the bottom surface of the concave groove 2012 The dimension in the width direction of 2012B is set to φ ₂ (= n _t +1/2).

Further, if j is the number of laminated secondary windings 202 in the concave groove 2012, there is a relationship of n ₂ = n _t × j, and the depth dimension h ₂ [mm] of the concave groove 2012 is an overlapping portion of each layer. When the dimensions and Δh ₂ [mm], is set to approximately (j-1) × (φ 2 -Δh 2) + φ 2 [mm].

In the concave groove 2012 of the bobbin main body 2011, the secondary winding 202 wound around each layer can be wound while being aligned at a pitch of the wire diameter φ _{2 in} the width direction of the concave groove 2012.

  The primary coil 1 manufactured by aligning and winding the primary winding 102 in the concave groove 1012 of the first coil bobbin 101 having a rectangular ring shape is a second coil bobbin 201 having a secondary ring 202 having a rectangular ring shape. As shown in FIG. 13, the first coil bobbin 101 is fitted into the hole portion of the second coil bobbin 201 from the front side and integrated with the secondary coil 2 manufactured by aligning and winding in the concave groove 2012. It becomes. Thereby, the coil part B which has arrange | positioned the secondary winding 202 concentrically on the outer side of the primary winding 102 is manufactured.

  As described above, according to the first coil bobbin 101 according to the present embodiment, the three small windings 1022a, 1022c, and 1022c of the winding number adjusting winding 1022 are formed in two layers in the second concave groove 1014, respectively. Since both ends of each of the windings 1022a, 1022c, and 1022c are drawn out of the first coil bobbin 101 from the winding lead portions 1015A, 1015B, 1015C, and 1015D, respectively, the three small windings 1022a, The position of the connection point connecting 1022b and 1022c in series does not occur in the middle of the aligned winding of the winding number adjusting winding 1022.

  Therefore, when the winding adjustment winding 1022 is aligned and wound in layers in the second concave groove 1014, no step is generated in any layer by drawing the winding in the middle, and the winding is wound in all layers. Can be aligned and wound with no gap.

  In addition, since the first guide groove 1016 for aligning and winding the small winding 1022a is provided on the bottom surface 1014B of the second concave groove 1014, the small winding 1022a is easily aligned with the first coil bobbin 101 without a gap. Can be wound. Then, the small windings 1022a located on the basis of the lamination are aligned and wound without gaps, so that the small windings 1022b and 1022b laminated on the outside of the small windings 1022a can be easily wound without gaps.

Further, since the depth h ₁ of the second concave groove 1014 is set to a height dimension when the three small windings 1022a, 1022c, and 1022c are laminated in a total of six layers, two layers are laminated. Further, the upper surface of the winding number adjusting winding 1022 substantially coincides with the position of the bottom surface 1013B of the first concave groove 1013.

  For this reason, even when the main winding 1021 is aligned and wound in the first concave groove 1013, the bottom surface 1013B of the first concave groove 1013 and the top surface of the laminated winding number adjusting winding 1022 are substantially horizontal, and the main winding When the wire 1021 is aligned and wound in the first concave groove 1013 in a layered manner, there is no step in the first layer, and all the layers can be aligned and wound without any gap.

  In addition, since the second guide groove 1017 for aligning and winding the small winding 1022 is provided on the bottom surface 1013B and the inner wall surfaces 1013A of the first concave groove 1013, the main winding 1021 is connected to the first coil bobbin 101. Can be easily aligned and wound without gaps.

  Further, since the cross-sectional shape of the first concave groove 1013 is an isosceles trapezoid whose upper base is longer than the lower base and the inner angles of both ends of the lower base are 120 ± α °, the main winding 1021 The wall surface 1013A can be aligned and wound so that there is no gap between the winding of each layer and the inner wall surface 1013A, and the space factor η of the primary winding 102 in the first coil bobbin 101 is made as much as possible. Can be high. Thereby, the primary coil 1 using the first coil bobbin 101 can be made compact, and the transformer A using the primary coil 1 can be made compact and the cost can be reduced.

Cross-sectional shape of the groove 1012 shown in Figure 5, cross-sectional shape is an isosceles trapezoid in a position where the area S _A in the case where the cross-sectional shape of the first groove 1013 has a rectangular becomes maximum in the region AR The first concave groove 1013 is disposed, and the second concave groove 1014 having a rectangular cross section is disposed at the center in the width direction of the bottom surface 1013B of the first concave groove 1013. The cross-sectional shape of 1012 may be modified as shown in FIG.

  The cross-sectional shape of the concave groove 1012 shown in FIG. 14A is such that the two corners Q ′ on the bottom surface side of the second concave groove 1014 are positioned on the arc of the area AR. The position in the area AR of the cross-sectional shape is shifted. In FIG. 14A, the cross-sectional shape of the concave groove 1012 indicated by a dotted line is the example shown in FIG. FIG. 14B shows a cross-sectional shape of the concave groove 1012 shown in FIG. 14A in which a step 1013C is provided on the hypotenuse portion of the cross-sectional shape of the first concave groove 1013.

  In the example shown in FIG. 14A, the position of the second concave groove 1014 in the area AR is as close to the inner peripheral side as possible, so the example shown in FIG. 5 (the cross-sectional shape of the concave groove 1012 indicated by the dotted line is shown). The dead space generated on the lower side of the first concave groove 1013 can be reduced.

  In the example of FIG. 14A, since the hypotenuse of the cross-sectional shape of the first concave groove 1013 is inside the hypotenuse indicated by the dotted line (example shown in FIG. 5), the cross-sectional shape of the first concave groove 1013 The thickness of the bobbin main body 101 at the oblique side is slightly thicker than the example shown in FIG. However, since the increase in thickness is not large, the space factor η of the primary winding 102 in the first coil bobbin 101 can be set to 70% or more even in the example shown in FIG.

  In the example shown in FIG. 14 (b), the thickness of the bobbin main body 101 is made more comprehensive than in the example shown in FIG. 14 (a) by providing a step 1013C in the oblique side portion of the cross-sectional shape of the first concave groove 1013. Can be made closer to D [mm], so that the space factor η of the primary winding 102 in the first coil bobbin 101 can be made better than the example shown in FIG.

  Further, since the variation in the overall thickness of the portion of the bobbin main body 101 where the concave groove 1012 is formed is reduced, the distance between the main winding 1021 and the winding adjustment winding 1022 wound in the concave groove 1012 and the iron core C can be reduced. Uniformity can be achieved. Thereby, the insulation characteristic of the primary winding 102 can be improved.

  In FIG. 14B, only one step 1013C is provided on both inner wall surfaces 1013A of the first groove 1013, but two or more steps 1013C may be provided.

  In the above embodiment, the case where the winding adjustment winding 1022 has a configuration in which three small windings 1022a, 1022b, and 1022c are connected in series has been described as an example. The number of lines 1022 is not limited to three, but may be one or four or more.

  The transformer A shown in the above embodiment has a structure in which only one cylindrical iron core C is provided on one leg portion of the coil part B. A structure in which each of the legs is provided with a cylindrical iron core C may be used. In this case, the winding lead portions 1015A to 1015E may be provided on the short side portion of the first coil bobbin 101, and the winding lead portion 2013 may be provided on the short side portion of the second coil bobbin 201.

  In the above embodiment, the coil part B used for the transformer A has been described. However, the present invention is not limited to the transformer, and is widely used for static induction equipment using a coil part having the same structure. can do.

A transformer B coil part C iron core 1 primary coil 101 first coil bobbin 1011 bobbin main body 1012 concave groove 1013 first concave groove 1013A inner wall surface of the first concave groove 1013B bottom surface of the first concave groove 1013C step 1014 second Groove 1014A Inner wall surface of first groove 1014B Bottom surface of second groove 1015A, 1015B, 1015C, 1015D, 1015E Notch (winding lead-out portion)
1016 First guide groove 1017 Second guide groove 102 Primary winding 1021 Main winding (first winding)
1022 Winding adjustment winding (second winding)
1022a, 1022b, 1022c Small winding 2 Secondary coil 201 Second coil bobbin 2011 Bobbin main body 2012 Concave groove 2012A Inner wall surface 2012B Bottom surface 2013 Notch portion 2014 Guide groove 202 Secondary winding BS1 (+), BS1 (-) Primary Bushing BS2 (+), BS2 (−), BS2 (G) Secondary bushing L _a1 , L _a2 , L _b1 , L _b2 , L _c1 , L _c2 , L _d1 , L _d2 Primary coil lead lines L _e1 , L _{e2, L e3} lead wire of the secondary coil P ₁ to P _4-tap terminal P _c common terminal T ₁ through T ₅ connection point TL tap changer

Claims (3)

The first winding has a shape arranged concentrically outside the second winding having a smaller number of turns than the first winding, and the first winding and the second winding Is a coil bobbin used for forming a winding adjustable coil connected in series via a tap,
A bobbin body that forms a frame and the cross-sectional shape of the side surface on the inner peripheral side of the frame is shaped into a semicircular shape;
A first groove formed on the outer peripheral side surface of the frame body for winding the first winding;
A second concave groove for winding the second winding, having a rectangular cross-sectional shape drilled in the bottom surface of the first concave groove;
With
It said inner wall surface facing the first groove, the so opening of the first groove becomes large phased toward the outer side from the inner peripheral side of the frame, inclined relative to the bottom surface And
The inclination angle of the inner wall surface with respect to the bottom surface is 120 ± α ° (α: an error within an allowable range),
A coil bobbin in which at least one step is provided on each of the opposed inner wall surfaces, and the wall surface of each step is inclined at an inclination angle of 120 ± α ° (α: an error within an allowable range) with respect to the bottom surface . A coil used as a primary coil of a stationary induction device,
A coil comprising the windings arranged in layers in the concave groove of the coil bobbin according to claim 1 . A transformer comprising the coil according to claim 2 as a primary coil.

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