JP6607808B2 - Coil bobbin, coil and transformer provided with the coil - Google Patents

Description

  The present invention relates to a coil bobbin, a coil in which a winding is wound around the coil bobbin, and a transformer including the coil.

  Conventionally, as a coil bobbin used for a coil for a transformer, it is made of a resin frame having a rectangular ring shape, and windings are wound around an outer peripheral side surface (hereinafter referred to as “outer peripheral side surface”) of the frame. 2. Description of the Related Art A coil bobbin in which a concave groove is formed is known.

  For example, in FIG. 6 of Patent Document 1, as the coil bobbin for the primary coil (high voltage coil), the inner wall surfaces of the both side walls are tapered on the outer peripheral side surface of a frame body having a rectangular ring shape so that the bottom surface side is tapered. A coil bobbin provided with a concave groove having an inclined cross-sectional shape is described. The long side portion of the frame body is a portion that becomes a leg portion to which a cylindrical iron core is attached after the primary coil is manufactured, and the inner peripheral side surface (hereinafter referred to as “inner peripheral side surface”) of the long side portion of the frame body. The cross-sectional shape of is called a semicircular shape. Moreover, the notch for drawing out the both ends of the coil | winding wound by the groove of the coil bobbin to the coil bobbin outside is provided in the short side part of the frame.

  In the coil bobbin described in FIG. 6 of Patent Document 1, the winding is drawn into the concave groove in a state in which one end is pulled out from the notch to the outside of the coil bobbin, and after repeating the aligned winding for a predetermined number of turns, The primary coil is created by drawing the end from the notch from the outside of the coil bobbin. Then, both end portions of the winding drawn out from the notch of the coil bobbin are connected to a pair of primary bushings (bushings to which a transformer primary voltage is applied) provided outside the coil bobbin.

JP-A-8-51034

  The coil bobbin functions as a guide member for winding the winding in a predetermined number of turns. Further, in the case of a structure in which a cylindrical iron core is attached in close contact with the leg portion of the primary coil, it functions as an insulating member that electrically insulates between the winding wound around the coil bobbin and the iron core.

  Therefore, the coil bobbin used for the coil of the transformer used outdoors needs to be insulated in consideration of the effect of lightning surge. For example, in the case of a 6600 [V] / 210-105 [V] transformer for power distribution, a lightning surge voltage of 60000 [V] or more may be applied to a primary coil to which a high voltage is applied. A coil bobbin for a coil requires an insulation design that can withstand the lightning surge voltage.

  A transformer in which a primary coil and a secondary coil are magnetically coupled with an iron core is generally used with the iron core set to a ground potential. For example, in a breakdown due to a lightning surge of a primary coil manufactured using a coil bobbin, discharge occurs through the coil bobbin that insulates between the winding position of the primary coil where the voltage is highest and the iron core. There is dielectric breakdown due to the occurrence. The position where the voltage of the primary coil is highest in the coil bobbin is the winding position at the end of the winding connected to the high voltage bushing, and is usually the winding start position or winding end position of the winding in the coil bobbin. Therefore, in the above design of dielectric breakdown, the thickness of the coil bobbin between the winding start position or the winding end position of the winding connected to the high voltage bushing and the iron core is a design parameter.

  In addition, dielectric breakdown due to lightning surge includes dielectric breakdown caused by discharging toward an iron core along a path along the surface of the coil bobbin from an arbitrary winding position of the primary coil. In the design of dielectric breakdown in this case, the creepage distance from an arbitrary winding position on the coil bobbin to the iron core is a design parameter.

  If the thickness of the coil bobbin (resin thickness) is increased, the creeping distance between the coil and the iron core generally tends to increase. Therefore, as a design for insulation against lightning surge, a method of sufficiently increasing the resin thickness of the coil bobbin is conceivable. However, when the resin thickness of the coil bobbin is increased, the coil bobbin is increased in size, weight, and cost. Therefore, it is desirable to design the resin thickness of the coil bobbin to be as thin as possible.

  If the resin thickness of the coil bobbin is designed to the minimum resin thickness that satisfies the specified dielectric strength, the creepage distance between the coil and the iron core may not be sufficient depending on the cross-sectional shape of the concave groove of the coil bobbin. is there.

  For example, as shown in FIG. 21, when the coil bobbin 100 for the high-voltage coil is fitted into the hole portion of the coil bobbin 200 for the secondary coil (low-voltage coil), the coil bobbin 100 is one of the concave grooves 101 of the coil bobbin 100. In this structure, the height of the side wall 102 from the bottom surface 101A is lower than the height of the other side wall 103 from the bottom surface 101A.

  For example, assuming that point A in FIG. 21 is the winding start position of the winding 105 of the high-voltage coil in the concave groove 101 and point B is the position of the iron core (not shown), the creepage distance from point A to point B is A After detouring the upper end of the side wall 102 along the inner wall surface of the concave groove 101 from the point, the distance of the path from the point to the point B along the outer wall surface of the side wall 102 is obtained. When the thickness of the side wall 102 is reduced, the creepage distance from the point A to the point B is shortened. However, when the height from the bottom surface 101A of the side wall 102 is reduced, the creepage distance is further shortened and the creepage distance on the side wall 102 is sufficiently large. It may become a design that cannot be taken.

  For example, when the groove 104 for drawing out the winding is provided on the side wall 102 of the coil bobbin 100 for the high voltage coil, the creeping distance in the groove 104 is the lower end of the groove 104 along the inner wall surface of the concave groove 104 from the point A. Since the distance of the path to the point B along the outer wall surface of the side wall 102 is obtained after detouring, it is difficult to secure a sufficient creepage distance at the formation position of the concave groove 104 on the side wall 102.

  The present invention has been made in view of the above problems, and a coil bobbin capable of an insulation design considering lightning surge without increasing its size and thickness more than necessary, and a coil in which a winding is wound around the coil bobbin And it aims at providing the transformer provided with the coil.

  A coil bobbin according to the present invention is a coil bobbin in which a concave groove is provided on the entire outer peripheral side surface of an annular frame, and a coil is wound around the concave groove to produce an annular coil. It is a coil bobbin provided with the insulation reinforcement part which reinforces insulation with the surface outside the side wall with the said coil and the iron core attached to the said coil.

  According to the above configuration, since the insulation reinforcing portion is provided on the outer surface of the side wall of the concave groove, the thickness of the coil bobbin interposed between the coil and the iron core is designed to be the minimum thickness that satisfies the specified withstand voltage. can do. Thereby, size reduction and weight reduction of a coil bobbin can be achieved.

  In the above-described coil bobbin, the insulation reinforcement portion may reinforce the insulation by increasing a creepage distance between the coil and the iron core.

  According to the above configuration, the insulation reinforcing portion reinforces the insulation between the coil and the iron core by increasing the creepage distance between the coil and the iron core attached to the leg portion of the coil. Even when the minimum thickness that satisfies the specified withstand voltage is designed, the withstand voltage due to the creepage distance can be sufficiently secured.

  In the coil bobbin described above, the insulation reinforcing portion may have a configuration in which any one of a concave portion, a convex portion, and a concave and convex portion is provided on the outer surface of the side wall.

  According to said structure, since either a recessed part, a convex part, or an uneven | corrugated | grooved part is provided in the outer surface of a side wall, from these coils to the iron core attached to the leg part of a coil from the coil wound by the groove The creepage distance along the surface of the coil bobbin can be increased.

  In the coil bobbin, the side wall of the concave groove includes a first side wall and a second side wall whose height from the bottom surface of the concave groove is lower than the height of the first side wall. The part may be configured to include one or two or more hook-shaped first protrusions protruding along the outer periphery of the frame body on the outer surface of the upper portion of the second side wall.

  According to said structure, when the height from the bottom face of the 2nd side wall is lower than the 1st side wall of a ditch | groove, it is 1 or 2 along the outer periphery of a frame on the surface outside a 2nd side wall. By projecting the above-described first ridge-shaped convex portion, it is possible to reinforce the insulation due to the creepage distance of the second side wall.

  In the above coil bobbin, the frame body has a rectangular frame shape, and the iron core is attached to a first frame side portion including a pair of opposite sides of the frame body, and the insulation The reinforcing portion may be provided in a second frame side portion including a pair of opposite sides of the frame body.

  According to said structure, the creeping distance between the part currently wound by the insulation reinforcement part on the 1st opposite side part of the coil bobbin of a coil and the iron core end surface of the iron core attached to the 2nd opposite side part of a coil bobbin is lengthened. Thus, the insulation can be reinforced.

  Further, in the coil bobbin, the insulation reinforcing portion is a hook-like second protruding from the inner peripheral side surface of the second frame side portion of the frame body along the inner periphery of the frame body. It is good to include a convex part.

  According to the above configuration, by providing the hook-shaped second convex portion along the inner periphery of the frame on the inner peripheral side surface of the second frame side portion of the frame, the first coil bobbin of the coil is provided. Insulation can be reinforced by increasing the creepage distance between the portion wound around the opposite side portion of 1 and the core end surface of the iron core attached to the second opposite side portion of the coil bobbin.

  The coil according to the present invention is a coil produced by aligning and winding a winding in the concave groove of the coil bobbin according to the present invention.

  According to the coil of the present invention, since the insulation reinforcing portion is provided on the outer surface of the side wall of the concave groove of the coil bobbin, the thickness of the coil bobbin interposed between the coil and the iron core is the minimum that satisfies the specified withstand voltage. The thickness can be designed. As a result, the coil bobbin can be reduced in size and weight, and as a result, the coil can be reduced in size, weight, and cost.

  The transformer according to the present invention includes a coil portion in which a second coil is concentrically arranged outside the first coil, and an iron core attached to one or both of the two leg portions opposite to each other of the coil portion. The first coil is manufactured by winding a winding around the concave groove of the coil bobbin according to any one of claims 1 to 6, and the second coil is formed of the coil bobbin. It is a transformer produced by winding a winding in a concave groove of a second coil bobbin that is externally fitted to the outside of the coil bobbin by fitting.

  According to the transformer of the present invention, since the insulation reinforcing portion is provided on the outer surface of the side wall of the concave groove of the coil bobbin, the thickness of the coil bobbin interposed between the coil and the iron core satisfies the specified withstand voltage. The minimum thickness can be designed. As a result, the coil bobbin can be reduced in size and weight, and as a result, the transformer including the coil manufactured using the coil bobbin can be reduced in size, weight, and cost.

  According to the coil bobbin and the like according to the present invention, the thickness of the coil bobbin interposed between the coil and the iron core can be designed to a minimum thickness that satisfies the specified withstand voltage, so that the coil bobbin can be reduced in size and weight. Can do. Thereby, size reduction, weight reduction, and cost reduction of the coil using the coil bobbin and the transformer including the coil can be achieved.

The perspective view which shows the structure of the transformer main body of the transformer provided with the coil produced using the coil bobbin which concerns on this invention. Diagram showing the circuit configuration of the transformer A front view of the first coil bobbin for producing the primary coil (high voltage coil) of the transformer The first coil bobbin is seen from the left side The top view of the first coil bobbin The first coil bobbin is viewed from below AA line sectional view of the first coil bobbin in FIG. BB sectional view of the first coil bobbin in FIG. Sectional drawing of the high voltage coil produced by winding the winding around the first coil bobbin A front view of the second coil bobbin for producing the secondary coil (low voltage coil) of the transformer The second coil bobbin is seen from the left side The top view of the second coil bobbin A view of the second coil bobbin seen from below CC sectional view of the second coil bobbin in FIG. The figure for demonstrating the manufacturing method of the coil part which has arrange | positioned the secondary coil concentrically outside the primary coil of the transformer Sectional view showing the structure of the coil section of the transformer The figure for demonstrating the effect | action and effect of the insulation reinforcement part provided in the said 1st coil bobbin. The figure which shows the modification of the insulation reinforcement part provided in the same 1st coil bobbin The figure for demonstrating the effect | action and effect of the other insulation reinforcement part provided in the said 1st coil bobbin. The figure which shows the modification of the other insulation reinforcement part provided in the said 1st coil bobbin Diagram for explaining creepage distance in coil bobbin insulation design

  Hereinafter, embodiments of a coil bobbin and the like according to the present invention will be described with reference to the drawings.

(Embodiment 1)
In the following description, a coil bobbin used for the primary coil and the secondary coil of the transformer will be described. The transformer according to the present embodiment has a structure in which a secondary coil is concentrically arranged outside the primary coil, and a cylindrical iron core is arranged outside the leg portions of both coils. 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 (transformer main body) of a transformer including a coil manufactured using a coil bobbin according to the present invention. FIG. 2 is a diagram showing a circuit configuration of the transformer.

  A transformer main body 1 shown in FIG. 1 includes an annular coil portion 2 in which a second coil 22 is disposed concentrically outside a first coil 21 (not visible in FIG. 1; see FIG. 15), and a coil portion. 2 and a cylindrical iron core 3 attached to each of two long side portions (hereinafter referred to as “leg portions”). The first coil 21 and the second coil 22 are manufactured using the first coil bobbin 4 (see FIGS. 3 to 8) and the second coil bobbin 5 (see FIGS. 10 to 14), respectively, as will be described later. ing.

  In the transformer main body 1, a high voltage of 6000 [V] or more from the power system is applied to the first coil 21, and a prescribed low voltage (for example, 100 [V] or 200 [] is supplied to the consumer from the second coil 22. V] is an example of a transformer body used for an oil-filled transformer for distribution (oil-cooled transformer).

  The transformer body 1 corresponds to a portion indicated by a dotted line in the circuit configuration of the transformer shown in FIG. The transformer main body 1 is accommodated in a tank (not shown) after the first coil 21 is connected to the tap changer TL attached to the transformer main body 1. The two high-pressure bushings BS1 (+), BS1 (−) and three low-pressure bushings BS2 (+), BS2 (−), BS2 (G) disposed in the tank are connected to a tap switch TL and a transformer. The second coil 22 of the main body 1 is electrically connected, and the tank is filled with insulating oil (not shown) to complete the transformer having the circuit configuration shown in FIG.

The two high-voltage bushings BS1 (+) and BS1 (−) are used to convert the primary voltage v ₁ (high voltage) (for example, 6300 to 6900 [V]) supplied from the high-voltage distribution line into the first coil of the transformer body 1. a bushing for applying 21, three low-pressure bushing BS2 (+), BS2 (- ), BS2 (G) is a secondary voltage ± _{v 2} to a low-voltage distribution line which is output from the transformer main body 1 This is a bushing for output.

Of the three low pressure bushings BS2 (+), BS2 (−) ₂ , BS2 (G), the low pressure bushing BS2 (G) is a grounded bushing, and the low pressure bushing BS2 (+) is a low pressure bushing. A low pressure of + v ₂ (for example, +100 [V]) is output to BS2 (G), and the low pressure bushing BS2 (−) is −v ₂ (for example, −100 [V] to the low pressure bushing BS2 (G). ]) Is a bushing for outputting a low pressure.

  In the following description, the first coil 21 will be referred to as a “high voltage coil 21” and the second coil 22 will be referred to as a “low voltage coil 22”. Further, in order to distinguish the first coil bobbin 4 for producing the high voltage coil 21 and the second coil bobbin 5 for producing the low voltage coil 22, the first coil bobbin 4 is referred to as "high voltage coil bobbin 4" and second The coil bobbin 5 will be referred to as a “low pressure coil bobbin 5”.

As shown in FIG. 2, the winding of the high-voltage coil 21 of the transformer body 1 (hereinafter referred to as “primary winding”) includes a main winding 211 that constitutes a main part of the total number of turns n ₁ , and the high-voltage coil 21. having a number of turns adjusting winding 212 constituting the total winding adjuster of turns n ₁ (the part for adjusting the number of turns of the total number of turns n ₁₎ of the.

Since the transformer body 1 is a step-down transformer, the total number of turns n ₂ of the winding of the low-voltage coil 22 (hereinafter referred to as “secondary winding”) is less than the total number of turns n ₁ of the primary winding. . Since the current flowing through the high voltage coil 21 is smaller than the current flowing through the low voltage coil 22, the wire diameter of the primary winding is smaller than the wire diameter of the secondary winding.

  The winding number adjusting winding 212 includes three small windings 212a, 212b, and 212c. The main winding 211 has a divided winding 211a and a divided winding 211b that are divided into two. As will be described later, the space of the concave groove 401 (see FIG. 4) for aligning the primary windings of the high voltage coil bobbin 4 (the main winding 211 and the winding number adjusting winding 212) is in the width direction (of the high voltage coil bobbin 4). It is divided into two in the thickness direction). The three small windings 212a, 212b, and 212c of the winding number adjustment winding 212 are aligned and wound in one space of the concave groove 401 (hereinafter referred to as “first space”). Part of the side connected to the winding number adjusting winding 212 is aligned and wound in the first space of the concave groove 401, and the rest is the other space of the concave groove 401 (hereinafter referred to as "second space"). Are aligned and wound.

  In the present embodiment, the portion wound in the first space and the portion wound in the second space of the concave groove 401 of the main winding 211 are connected in series outside the coil bobbin 4. is there. Therefore, the main winding 211 is divided into two, one divided winding 211a is aligned and wound in the first space of the groove 401, and the other divided winding 211b is aligned and wound in the second space of the groove 213. I am doing so.

  In the circuit configuration of the transformer body 1 shown in FIG. 2, three small windings 212a, 212b, and 212c are connected in series, and the small winding 212c and the main winding 211 of the winding number adjusting winding 212 are connected in series. Thus, the primary winding is configured. The connection points of the small winding 212a and the small winding 212b, the small winding 212b and the small winding 212c, the small winding 212c and the main winding 211, and the open terminals of the small winding 212a serve as taps.

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 high voltage bushing BS1 (+). Ends of Komaki line 212a is connected to the tap terminal P ₁ and the tap terminal _{P 2} respectively, at both ends of Komaki line 212b is connected to the tap terminal _{P 2} and the tap terminal _{P 3} respectively, opposite ends of Komaki line 212c, respectively It is connected to the tap terminals _{P 3} and the tap terminal _{P 4.} While each end and the other end of the split winding 211b tap terminal _{P 4} and the high-pressure bushing BS1 discrete winding wirings 211a (-) is connected to the other end and one end of the split winding 211b of the split winding 211a coil bobbin 4 Connected to each other outside.

In FIG. 2, connection points T _{1 to} T ₅ and a relay terminal Q ₁ are shown to indicate connection points between the main winding 211 and the winding number adjustment winding 212. Thus, in FIG. 2, to connect the two ends of the small roll lines 212a to each connection point _{T 1} and the connection point _{T 2,} and connecting both ends of the small roll wire 212b to each connection point _{T 2} and the connection point _{T 3,} Komaki connecting the two ends of the line 212c to a connection point _{T 4} respectively connecting point _{T 3.} Also, connect the two ends of the split windings 211a to the connection point _{T 5} respectively connecting points _{T 4,} connect one end of the split winding 211b to the connection point _{T 5,} the other end of the split winding 211b relay terminal Q ₁ is connected.

  Although not shown in FIG. 1, both ends of the divided winding 211a, both ends of the divided winding 211b, and both ends of the small windings 212a, 212b, and 212c are drawn from the coil portion 2 of the transformer body 1. ing. Further, both ends of the winding (secondary winding) of the low voltage coil 22 and the intermediate position c are drawn out from the coil portion 2 of the transformer body 1.

In the transformer, the total number of turns n ₁ of the high-voltage coil 21 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 211a, 211b, respectively turns _n a of _211c, n b, and _{n c,} the number of turns of the primary winding 211 and _{n d,} total number of turns _{n 1} of the high pressure coil 21, _{(n a + n b + n c + n} d), (n b + n c + n d), it can be switched to four kinds of _{(n c + n d),} n d.

  In the following description, a case will be described in which the transformer body 1 according to the present embodiment is applied to a 6600 [V] / (210-105 [V] oil-filled transformer for power distribution.

Since the primary voltage input to the high voltage coil of the transformer varies greatly depending on the distance from the distribution substation around the customer where the 6600 [V] / (210-105) [V] transformer is arranged. In general, power is transmitted from the distribution substation at a voltage higher than 6600 [V]. Therefore, the primary voltage v ₁ input to the high voltage coil 21 of the transformer becomes a high voltage of 6600 [V] or more at a location near the distribution substation, and a high voltage of 6600 [V] or less at a location far from the distribution substation. May be.

Transformer body 1 adjusts the total number of turns _{n 1} of the high voltage coil 21 into four stages according to the size of the primary voltage _{v 1,} the secondary voltage _{v 2} of stable from the low pressure coil 22 (210-105) [V] Output is enabled. 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 body 1 is expressed by (v ₁ / v ₂ ) = (n ₁ / n ₂ ). Since v ₂ and n ₂ are fixed, the total number of turns n ₁ of the high voltage coil 21 is proportional to the primary voltage v ₁ . Therefore, the voltage v _A , v _B , v _C , v _D of each tap is applied to the number of turns of the high-voltage coil 21 (n _a + n _b + n _c + n _d ), (n _b + n _c + n _d ), (n _c + n _d ). , 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 212a, 212b, and 212c is the same.

  Next, the structure of the high voltage coil 21 and the low voltage coil 22 will be described. First, the structure of the high voltage coil 21 will be described with reference to FIGS.

  3 is a view of the high voltage coil bobbin 4 (coil bobbin according to the present invention) for producing the high voltage coil 21 of the transformer as viewed from the front, FIG. 4 is a view of the high voltage coil bobbin 4 as viewed from the left side, and FIG. FIG. 6 is a view of the high-voltage coil bobbin 4 seen from above, FIG. 6 is a view of the high-voltage coil bobbin 4 seen from below, FIG. 7 is a cross-sectional view taken along line AA in FIG. 4, and FIG. FIG. FIG. 9 is a cross-sectional view of a high voltage coil 21 produced by winding a primary winding around the high voltage coil bobbin 4.

  In the following description, in FIG. 3, the outer peripheral side surface of the annular high-voltage coil bobbin 4 is referred to as “outer peripheral side surface”, and the inner peripheral side surface is referred to as “inner peripheral side surface”. In the following description, the surface is referred to as “front”, and the left surface is referred to as “back”.

  The high voltage coil 21 is formed into a rectangular ring shape (ring shape) using the high voltage coil bobbin 4. As shown in FIGS. 3 and 4, the high-voltage coil bobbin 4 has a ring shape with a short rounded rectangular shape. The high voltage coil bobbin 4 is produced by molding a resin.

  The high-voltage coil bobbin 4 is provided with a concave groove 401 for winding the primary winding (the main winding 211 and the winding number adjusting winding 212) on the outer peripheral side surface. The two side walls 402 and 403 constituting both wall surfaces of the recessed groove 401 have a rounded rectangular ring shape. The outer dimension (L2 (length in the longitudinal direction) × W2 (length in the short direction)) of the side wall 403 on the back side (hereinafter referred to as “second side wall 403”) is the side wall 402 on the front side (hereinafter referred to as length in the short side direction). , “First side wall 402”) is set to a size smaller than the external dimension (L1 (length in the longitudinal direction) × W1 (length in the short direction)). This is because, as shown in FIG. 15, the high voltage coil bobbin 4 is fitted into the hole portion of the low voltage coil bobbin 5 to produce the coil part 2 in which the low voltage coil 22 is disposed concentrically outside the high voltage coil 21. .

  Accordingly, the outer dimension (L2 × W2) on the back side of the high-voltage coil bobbin 4 is the dimension of the hole portion of the low-voltage coil bobbin 5 (L4 (length in the longitudinal direction) × W4 (length in the short direction)) (FIG. 10). The size is set to be slightly smaller than the reference. On the other hand, the outer dimension (L1 × W1) on the front side of the high-voltage coil bobbin 4 is the outer dimension (L3 (length in the longitudinal direction) × W3 (length in the short direction) of the low-voltage coil bobbin 5 having a rounded rectangular ring shape. )) (See FIG. 10) is set to approximately the same dimensions.

  The inner peripheral side surface of the two short side portions 4A (see FIG. 3; hereinafter referred to as “first opposite side portion 4A”) in the opposite side relationship of the high voltage coil bobbin 4 is a flat surface (see FIG. 8). The inner peripheral side surface of two long side portions 4B (see FIG. 3; hereinafter referred to as “second opposite side portion 4B”) in the opposite side relationship of the coil bobbin 4 is a curved surface protruding in a semicircular shape inside. (See FIG. 7). Although the inner peripheral side surface of the first opposite side portion 4A of the high-voltage coil bobbin 4 is also a curved surface, a plate-like insulation reinforcing portion 410A is provided at the tip of the curved surface, so that the high-voltage coil bobbin 4 The surface facing the hole is a flat surface. The insulation reinforcing portion 410A will be described later.

  The reason why the cross-sectional shape of the inner peripheral side surface of the second opposite side portion 4B of the high voltage coil bobbin 4 is a semicircular shape is that a cylindrical iron core 3 is formed on the second opposite side portion 4B of the high voltage coil bobbin 4 as shown in FIG. This is because the inner surface of the circular hole of the iron core 3 is in close contact with the second opposite side portion 4B of the high-voltage coil bobbin 4. Accordingly, each long side of the second opposite side portion 4B of the high voltage coil bobbin 4 corresponds to a leg portion (a portion to which the iron core 3 is attached) of the high voltage coil 21. The radius of the curved cross-sectional shape of the portion corresponding to the leg portion of the high voltage coil bobbin 4 is set to be slightly smaller than the radius of the circular hole of the iron core 3.

  In the following description, for convenience of description, each long side portion of the second opposite side portion 4B of the high voltage coil bobbin 4 may be referred to as a “leg portion 4B”. The iron core 3 is attached to the leg portion 4B of the high-voltage coil bobbin 4 by, for example, attaching a belt-shaped electromagnetic steel plate around the leg portion 4B of the high-voltage coil bobbin 4.

  The concave groove 401 of the high voltage coil bobbin 4 includes a first concave groove 401A around which the main winding 211 is wound and a second concave groove 401B around which the winding number adjusting winding 212 is wound. The second concave groove 401B is formed in the center of the bottom surface 404 of the first concave groove 401A in the width direction (thickness direction of the high-voltage coil bobbin 4, lateral direction in FIG. 4).

  At the center of the bottom surface 405 of the second groove 401B, a dividing wall 406 (see FIG. 4) that divides the space of the groove 401 in the width direction is provided. For example, in FIG. 4, the right space (the space on the first side wall 402 side) of the groove 401 divided by the dividing wall 406 corresponds to the “first space”, and the left side space (the second side wall 403). Side space) corresponds to the “second space”.

  The dividing wall 406 is provided perpendicular to the bottom surface 405 of the second concave groove 401B. The dividing wall 406 is a thin plate-like member having a height from the bottom surface 405 to the vicinity of the upper end of the second side wall 403. The dividing wall 406 is provided on the bottom surface 405 of the high-voltage coil bobbin 4 by integral molding of resin.

  The shape of the second groove 401B is a shape (rectangular shape) in which the bottom surface 405 of the second groove 401B and the inner wall surfaces on both sides rise vertically (see FIGS. 4 and 5). This is because the number of turns when the three small windings 212a, 212b, and 212c are aligned and wound in two layers in the first space of the second concave groove 401B is the same.

  On the other hand, the first groove 401A has a shape (in which the inner wall surfaces on both sides rise from the bottom surface 404 of the first groove 401A with a predetermined inclination angle θ (for example, 120 [°]). Isosceles trapezoidal shape) (see FIG. 4).

  Although not shown in FIGS. 4 to 6, at the four corners of the high-voltage coil bobbin 4, a winding position for aligning and winding the small winding 212 a on the bottom surface 405 of the second groove 401 </ b> B is guided. A guide groove is provided, and a guide groove for guiding a winding position for aligning and winding the divided winding 211a is provided on the bottom surface 404 of the first concave groove 401A. The guide groove is a groove having an arc-shaped cross section having a groove width shorter than ½ of the diameter of the primary winding. A predetermined number of guide grooves are formed in the bottom surface 404 and the bottom surface 405 in the width direction.

  Of the grooves 401 formed on the entire outer peripheral side surface of the high-voltage coil bobbin 4, the primary winding is wound around the grooves 401 (see the groove 401 shown in FIG. 4) formed on the second opposite side portion 4B. The second side wall 403 passes from the first side wall 402 through the bottom surface 405 of the second concave groove 401B in a direction intersecting with the direction (vertical direction in FIG. 4) (direction perpendicular to FIG. 4). A plurality of grooves 407A (see FIGS. 4 and 7) are provided. In the example of FIG. 4, six grooves 407 </ b> A are provided in two long side portions of the high-voltage coil bobbin 4 that face each other. By providing the groove 407A in the concave groove 401, as shown in FIG. 7, the resin thickness d1 of the portion where the groove 407A of the high voltage coil bobbin 4 is provided is thinner than the resin thickness d2 of the other portion.

  The plurality of grooves 407A minimizes the contact area where the lowermost winding contacts the bottom surface 405 of the second concave groove 401B when the primary winding is aligned in multiple layers in the concave groove 401. Thus, the contact area with the insulating oil of the high voltage coil 21 produced by aligning the primary windings around the high voltage coil bobbin 4 in multiple layers is made as wide as possible. The cooling of the transformer by the oil cooling method is performed by bringing the insulating oil into contact with the high-voltage coil 21 and the low-voltage coil 22 of the transformer main body 1 and transferring the heat generated in these coils 21 and 22 to the insulating oil, and the insulating oil is tanked. It is performed by discharging to the outside air with a cooling device (for example, a large number of fins attached to the side surface of the tank). Accordingly, the plurality of grooves 407A fulfill the function of increasing the heat receiving efficiency of the insulating oil by increasing the contact area of the insulating oil to the high voltage coil 21 as much as possible.

  Since the bottom surface 4071 (see FIG. 7) of the plurality of grooves 407A is lower than the bottom surface 405 of the second concave groove 401B, the lowermost winding wound in the concave groove 401 is the second winding of the high-voltage coil bobbin 4. In the opposite side portion 4B, only the portion 407B (see FIG. 4; hereinafter referred to as “winding support portion 407B”) between the adjacent grooves 407A is in contact with the bobbin, and the portion of the groove 407A is in contact with the bobbin. Do not touch.

  Accordingly, the high voltage coil 21 in which the primary winding is aligned and wound in multiple layers in the concave groove 401 is in a state of floating from the inner wall surface of the bobbin at the groove 407A in the second opposite side portion 4B of the high voltage coil bobbin 4 (the groove 407A A cavity is formed in the portion), and the contact area where the high voltage coil 21 contacts the inner wall surface of the concave groove 401 is smaller than the case where the groove 407A is not provided.

  In the present embodiment, the plurality of grooves 407A are formed in a direction orthogonal to the winding direction of the primary winding, but the plurality of grooves 407A are formed by the strip-shaped winding support portion 407B. As long as the direction intersects with the winding direction, it may be formed in any direction. In the present embodiment, six grooves 407A are provided in each long side portion of the high-voltage coil 21, but the number of grooves 407A is not limited to this. In the present embodiment, the shape of the groove 407A is a horizontally long rectangular shape, and the shape of the winding support portion 407B is a strip shape. However, the shape of the groove 407A and the winding support portion 407B is limited to these shapes. Any shape can be adopted as long as the contact area with the groove 401 of the high voltage coil 21 can be reduced.

  One short side portion of the first side wall 402 of the high-voltage coil bobbin 4 (upper short side portion in FIG. 3) and one short side portion of the second side wall 403 (upper short side portion in FIG. 3). Are each provided with four notches 408 (see FIG. 5). The four notches 408 are provided in the central portion of the short side portion of the high voltage coil bobbin 4. The four notches 408 in the first side wall 402 and the four notches 408 in the second side wall 403 are provided so that the notches 408 face each other.

  Four notches 408 provided in the first side wall 402 are divided windings 211 a of the main winding 211 and windings of the winding adjustment coil 212 that are aligned and wound in the first space of the groove 401. This is for pulling out both ends of the windings 212a, 212b, and 212c. The four notches 408 are slit-like notches extending from the upper end of the first side wall 402 (the outer peripheral end of the high-voltage coil bobbin 4) to the bottom surface 405 of the second concave groove 401B. The first space communicates with the outside of the first side wall 402 by four notches 408.

  In order to distinguish the four cutouts provided in the first side wall 402, the cutouts are labeled "408A", "408B", "408C", "408D", for example, in FIG. 4 notches 408A, 408B, 408C, 408D are arranged in order.

  For example, small windings 212a, 212b, and 212c are arranged in two layers from the bottom surface 405 in this order in the first space of the second concave groove 401B, and divided windings in the first space of the first concave groove 401A. When 211a is wound in multiple layers from the bottom surface 404, both ends of each winding are drawn from the high-voltage coil bobbin 4 as follows, for example.

  That is, both ends of the small winding 212a are drawn out of the high voltage coil bobbin 4 from the cutout 408A, and both ends of the small winding 212b are drawn out of the high voltage coil bobbin 4 from the cutout 408B. The portion is pulled out from the notch 408C to the outside of the high voltage coil bobbin 4. Then, both end portions of the divided winding 211a are drawn out of the high voltage coil bobbin 4 from the notch 408D.

  The four cutouts 408A, 408B, 408C, and 408D communicate the first space with the outside of the first side wall 402, so that only the function of pulling out both ends of the windings aligned and wound in the first space is used. And has a function of allowing the insulating oil to flow between the first space and the outside of the high-voltage coil bobbin 4. That is, the four notches 408A, 408B, 408C, and 408D are formed in the insulating oil groove 401 when the high voltage coil 21 produced by aligning and winding the primary windings in multiple layers on the high voltage coil bobbin 4 is cooled by the insulating oil. The function of improving the cooling efficiency of the transformer by the oil cooling system is improved by improving the convection efficiency to the inside and outside.

  The four cutouts 408 provided in the second side wall 403 are also both end portions of the windings aligned and wound in the second space, like the four cutouts 408 provided in the first side wall 402. And the function of allowing the insulating oil to flow between the second space and the outside of the high voltage coil bobbin 4 (function of improving convection efficiency). Note that the function of pulling out both ends of the winding wound in alignment in the second space has a function of one or two cutouts 408 out of the four cutouts 408.

  For example, in FIG. 5, among the four notches 408 provided on the second side wall 403, if the leftmost notch 408 is a notch 408E for drawing out the winding, the winding is aligned in the second space. Both ends of the divided winding 211b are drawn out from the notch 408E to the outside of the high voltage coil bobbin 4. Note that both ends of the divided winding 211b may be drawn out of the high-voltage coil bobbin 4 from the cutout 408E and the other cutout 408, respectively.

  On the other hand, the other short side portion (the lower short side portion in FIG. 3) of the first side wall 402 of the high voltage coil bobbin 4 may be referred to as four windows 409 (through holes 409). ) And four cutouts 408 (see FIG. 6) are provided on the other short side portion of the second side wall 403 (the lower short side portion in FIG. 3).

  The four windows 409 are for allowing the insulating oil to flow between the first space and the outside of the high voltage coil bobbin 4, and the four notches 408 are for the insulating oil to pass through the second space. This is for flowing between the high-voltage coil bobbin 4 and the outside. The four windows 409 on the first side wall 402 and the four notches 408 on the second side wall 403 are provided so that the windows 409 and the notches 408 face each other. Note that the four windows 409 provided in the first side wall 402 may be notched instead of the through holes.

  In the present embodiment, since the two iron cores 3 are attached to the second opposite side portion 4B of the high voltage coil bobbin 4, in order to avoid interference with the iron core 3, notches 408 for increasing the convection efficiency of the insulating oil and A window 409 is provided on the second opposite side portion 4 </ b> B of the high-voltage coil bobbin 4. In addition, in a transformer in which the transformer body is housed in a tank containing insulating oil, the insulating oil normally circulates from the top to the bottom in the periphery of the tank and from the bottom to the top in the center of the tank. Convection as you do. The transformer body 1 shown in FIG. 1 is housed in a tank with two iron cores 3 aligned horizontally, so that the convection of insulating oil when the transformer is operated efficiently passes through the concave groove 401 of the high-voltage coil bobbin 4. In this embodiment, a cutout 408 and a window 409 are provided in the lower short side portion and the upper short side portion of the high-voltage coil bobbin 4 so as to pass well.

  With this configuration, in the high voltage coil bobbin 4 according to the present embodiment, the insulating oil enters the recessed groove 401 from the four notches 408 and the four windows 409 provided in the short side portion on the lower side of the high voltage coil bobbin 4. Flow into. The insulating oil that has flowed into the concave groove 401 passes through the left and right long side portions of the high voltage coil bobbin 4 and rises to the short side portion on the upper side of the high voltage coil bobbin 4. Then, the rising insulating oil flows out of the high-pressure coil bobbin 4 from the eight notches 408 provided on the upper short side portion of the high-voltage coil bobbin 4.

  The insulating oil receives the heat generated by the high voltage coil 21 by contacting the high voltage coil 21 while flowing in the concave groove 401 of the high voltage coil bobbin 4, so that the heat generated in the high voltage coil 21 by the convection described above is received by the high voltage coil bobbin 4. Can be efficiently discharged to the outside.

  Further, at the left and right long sides of the high voltage coil bobbin 4 in the concave groove 401, the contact area between the insulating oil and the high voltage coil 21 is made as much as possible by supporting the high voltage coil 21 with a plurality of winding support portions 407B. Since it is increased, the heat receiving efficiency of the insulating oil is improved. Therefore, in the high voltage coil bobbin 4 according to the present embodiment, the heat generated in the high voltage coil 21 can be efficiently discharged to the outside of the high voltage coil bobbin 4 by the synergistic effect of the improvement of the convection efficiency and the improvement of the heat receiving efficiency. .

  As described above, the eight cutouts 408 provided in one short side portion of the high voltage coil bobbin 4, the four cutouts 408 provided in the other short side portion of the high voltage coil bobbin 4, and the four windows 409 are provided. The number of the cutouts 408 and the windows 409 is not limited to the above-mentioned number because the insulating oil is mainly used to enter and exit between the outside of the high-pressure coil bobbin 4 and the inside of the groove 401. Absent.

  For example, in FIG. 3, the number of notches 408 and windows 409 provided in the lower short side portion of the high voltage coil bobbin 4 may be 3 or less, respectively, or 5 or more. Of the four cutouts 408 provided in the upper short side portion of the high-voltage coil bobbin 4, the number of cutouts mainly for insulating oil convection (for example, cutouts 408 other than the cutouts 408A to 408E) Is not limited to the above number, and can be set to any number. Further, the shape of the notch 408 for insulating oil convection is not limited to the shape on the slit, and any shape can be adopted.

  On the outer surface of the first opposite side portion 4A of the first side wall 402, the insulation between the high voltage coil 21 aligned and wound in the groove 401 and the iron core 3 attached to the leg portion of the high voltage coil bobbin 4 is reinforced. An insulation reinforcing portion 410 is provided.

The iron core 3 attached to the leg portion 4B of the high-voltage coil 21 and the high-voltage coil bobbin 4 aligned and wound in the concave groove 401 is configured to be electrically insulated by the interposition of the resin-made high-voltage coil bobbin 4. Usually, since the transformer is used with the iron core 3 set to the ground potential, the insulation design of the high voltage coil bobbin 4 takes into account the super high voltage in which the lightning surge voltage is superimposed on the high voltage v ₁ applied to the high voltage coil 21. it is necessary to design the thickness of the provisions of the breakdown voltage V _T at the legs 4B of the high-pressure coil bobbin 4 so as not to cause dielectric breakdown.

As shown in FIG. 7, the thickness of the groove 401 formed in the leg portion 4 </ b> B of the high-voltage coil bobbin 4 varies depending on the position of the inner wall surface of the groove 401. The voltage also varies from layer to layer. For example, when a lightning surge occurs in the circuit state shown in FIG. 2, the voltage at the end connected to the high voltage bushing BS1 (+) of the small winding 212a becomes an extremely high voltage. As will be described later, since the small winding 212a is wound in two layers on the bottom surface 405 of the second concave groove 401B, the small winding connected to the high voltage bushing BS1 (+) of the second concave groove 401B. The voltage at the position where the end of the wire 212a is drawn (winding drawing position) becomes the highest. Thus, the insulation design of the high-pressure coil bobbin 4, it is necessary that the resin thickness corresponding to the linear distance between the iron core 3 in the windings lead of Komaki line 212a is designed so as not to cause dielectric breakdown withstand voltage V _T . Note that the resin thickness of the high-voltage coil bobbin 4 at the winding lead position corresponds to the distance of the discharge path when discharge occurs in the iron core 3 through the high-voltage coil bobbin 4 at the winding lead position.

If increasing the resin thickness, increase can be obtained sufficient insulation performance for the provision of breakdown voltage V _T, the amount of resin is increased, an increase in the size of the high-pressure coil bobbin 4, with leads to weight reduction, manufacturing cost There is a problem of doing. Thus, the insulation design of the high-pressure coil bobbin 4, it would be desirable to design the minimum resin thickness D _min satisfying breakdown voltage V _T as much as possible the resin thickness.

In the insulation design of the high voltage coil bobbin 4, it is necessary to consider the creepage distance between the high voltage coil 21 and the iron core B as well as the design of the resin thickness of the high voltage coil bobbin 4. The creepage distance is the distance of the discharge path on the bobbin surface when a discharge occurs in the iron core B along the surface of the high voltage coil bobbin 4 from the high voltage coil 21. Even if you set the resin thickness to a minimum resin thickness D _min, when there is sufficient creepage distance can not be taken part in the high-pressure coil bobbin 4, in that part, a possibility that a discharge is generated at a lower voltage than breakdown voltage V _T There is. Insulation reinforcing portion 410 is intended to reinforce the strength of the insulating high-pressure coil bobbin 4 by lengthening the creepage distance of the portion that may be discharged at a voltage lower than the breakdown voltage V _T is generated.

As described above, a plurality of notches 408 and a plurality of windows 409 are provided on the first opposite side portion 4 </ b> A of the high-voltage coil bobbin 4. As shown in FIG. 1, when the transformer main body 1 is assembled, a plurality of notches 408 and windows 409 provided in the high voltage coil bobbin 4 are positioned to face the core end surface 3 </ b> A with respect to the iron core 3. In the portion where the notch 408 and the window 409 of the coil bobbin 4 are formed, there is a possibility that the creepage distance between the high voltage coil 21 and the iron core B cannot be sufficiently obtained.

  Therefore, in the present embodiment, an insulating reinforcing portion 410A made of a rod-shaped convex piece is provided at a portion between the notch 408 and the window 409 and the core end surface 3A of the iron core 3 of the first opposite side portion 4A of the high voltage coil bobbin 4. Provided. As shown in FIG. 8, the insulation reinforcing portion 410 </ b> A is provided by extending a plate-like member by integral molding at the distal end portion of the curved surface on the inner peripheral side surface of each short side portion of the high-voltage coil bobbin 4. Therefore, the first side wall 402 and the second side wall 403 of the high-voltage coil bobbin 4 are each provided with a member made of a square bar-like convex piece as the insulation reinforcing portion 410A. The operation and effect of the insulation reinforcing portion 410A will be described later.

The second side wall 403 of the high-voltage coil bobbin 4 is smaller in size than the first side wall 402 as shown in FIGS. 7 and 8, and the height h2 from the bottom surface 405 of the side wall on the back surface side of the concave groove 401. Is lower than the height h1 from the bottom surface 405 of the front side wall. For this reason, there is a possibility that the creepage distance between the high voltage coil 21 and the iron core B cannot be sufficiently obtained even at the peripheral portion of the second side wall 403 of the high voltage coil bobbin 4 (the portion constituting the side wall on the back side of the concave groove 401). is there.

  Therefore, in the present embodiment, an insulation reinforcing portion 410B (see FIG. 8) having a rectangular cross section along the outer periphery of the high voltage coil bobbin 4 is formed on the outer surface of the upper portion of the second side wall 403 of the high voltage coil bobbin 4. It is provided to go around.

  Note that, as shown in FIG. 8, a flange 4031 protruding outward is provided at the upper end of the second side wall 403 of the high-voltage coil bobbin 4. The flange 4031 is formed by fitting the high-voltage coil bobbin 4 (high-voltage coil 21) with the primary winding aligned in the hole of the low-voltage coil bobbin 5 (low-voltage coil 22) with the secondary winding aligned. It functions as an engagement member between the high voltage coil bobbin 4 and the low voltage coil bobbin 5 when the coil part 2 having the low voltage coil 22 concentrically arranged on the outside is manufactured.

  The protrusions of the insulation reinforcing portion 410B provided in parallel with the flange portion 4031 have the same shape as that of the flange portion 4031, and also function as an engagement member between the insulated auxiliary high voltage coil bobbin 4 and the low voltage coil bobbin 5. The operation and effect of the insulation reinforcing portion 410B will also be described later.

  Next, the winding method of the primary winding to the concave groove 401 of the high voltage coil bobbin 4 will be briefly described with reference to FIG. FIG. 9 is a sectional view showing a state in which the main winding 211 and the winding number adjustment winding 212 are aligned and wound in the concave groove 401 of the high-voltage coil bobbin 4.

  In the concave groove 401 of the high-voltage coil bobbin 4, first, the small winding 212a of the winding number adjustment winding 212 is wound in the second space of the second concave groove 401B in a two-layer structure. The small winding 212a is, for example, aligned and wound from the second side wall 403 side to the dividing wall 406 in a state where one end (portion serving as a lead wire) is pulled out from the notch 408A to the outside of the high voltage coil bobbin 4. The small winding 212a is folded back by the dividing wall 406, and is wound up to the second side wall 403 using a recess between the windings formed on the upper surface of the first layer of the small winding 212a as a guide. Then, the other end portion (portion serving as a lead wire) of the small winding 212a is pulled out from the notch 408A to the outside of the high voltage coil bobbin 4.

  Next, the small winding 212b of the winding number adjustment winding 212 is wound on the small winding 212a in a two-layer structure. The small winding 212b is wound in an aligned manner from the second side wall 403 side to the dividing wall 406 with one end portion (portion serving as a lead wire) pulled out from the notch 408B to the outside of the high voltage coil bobbin 4. The small winding 212b is folded back by the dividing wall 406, and is wound up to the second side wall 403 using a depression between the windings formed on the upper surface of the first layer of the small winding 212b as a guide. Then, the other end portion (portion serving as a lead wire) of the small winding 212b is drawn out of the high voltage coil bobbin 4 from the notch 408B.

  Next, the small winding 212c of the winding number adjustment winding 212 is wound on the small winding 212b in a two-layer structure. The small winding 212c is wound in an aligned manner from the second side wall 403 side to the dividing wall 406 with one end portion (portion serving as a lead wire) pulled out from the notch 408C to the outside of the high voltage coil bobbin 4. The small winding 212c is folded back by the dividing wall 406, and is wound up to the second side wall 403 using a recess between the windings formed on the upper surface of the first layer of the small winding 212b as a guide. Then, the other end portion (portion serving as the lead wire) of the small winding 212c is drawn out of the high voltage coil bobbin 4 from the notch 408C.

  Next, the split winding 211a of the main winding 211 is wound around the first concave groove 401A in a multilayer structure. Since the small winding 212c is wound on the upper end of the second concave groove 401B, the divided winding 211a is wound on the small winding 212c.

  The divided winding 211a is aligned and wound from the second side wall 403 side to the divided wall 406 in a state where one end (portion serving as a lead wire) is pulled out from the notch 408D to the outside of the high voltage coil bobbin 4. The divided winding 211a is folded back by the dividing wall 406, and is wound up to the second side wall 403 using a depression between the windings formed on the upper surface of the first layer of the divided winding 211a as a guide. Thereafter, the split winding 211a is folded while being folded each time it reaches the inner wall surface of the split wall 406 and the second side wall 403 by using a depression between the windings formed above the split winding 211a of each layer as a guide. It is wound until the number reaches a predetermined number. Then, the other end (portion serving as a lead wire) of the divided winding 211a is drawn out of the high voltage coil bobbin 4 from the notch 408D.

  Next, the divided winding 211b of the main winding 211 is wound in the first space of the concave groove 401 with a multilayer structure. The divided winding 211b is aligned and wound from the first side wall 402 side to the divided wall 406 in a state where one end portion (portion serving as a lead wire) is pulled out from the notch 408E to the outside of the high voltage coil bobbin 4. The divided winding 211b is folded back by the dividing wall 406, and is wound up to the first side wall 402 using a depression between the windings formed on the upper surface of the first layer of the divided winding 211b as a guide. After that, the divided winding 211b is folded while being folded each time it reaches the inner wall surface of the divided wall 406 and the first side wall 402 by using the depression between the windings formed above the divided winding 211b of each layer as a guide. It is wound until the number reaches a predetermined number. Then, the other end (portion to be a lead wire) of the divided winding 211b is pulled out from the notch 408E to the outside of the high voltage coil bobbin 4.

  Next, the structure of the low voltage coil 22 will be described with reference to FIGS.

  10 is a view of the low-voltage coil bobbin 5 for producing the low-voltage coil 22 of the transformer as viewed from the front, FIG. 11 is a view of the low-voltage coil bobbin 5 as viewed from the left side, and FIG. FIG. 13 is a view as seen from above, FIG. 13 is a view when the low-voltage coil bobbin 5 is seen from below, and FIG. 14 is a cross-sectional view taken along the line CC in FIG.

  The low voltage coil 22 is formed into a rectangular ring shape (ring shape) using the low voltage coil bobbin 5. As shown in FIGS. 10 and 11, the low-voltage coil bobbin 5 has a short rounded rectangular ring shape, and the shape viewed from the side surface of the low-voltage coil bobbin 5 is substantially bilaterally symmetric. The low-voltage coil bobbin 5 is also produced by molding a resin.

  In the following, for convenience of explanation, in FIG. 11, the surface along the outer periphery of the ring shape is referred to as “outer peripheral side surface”, and the surface along the inner periphery is referred to as “inner peripheral side surface”. The surface is referred to as “front”, and the left surface is referred to as “back”.

  The low voltage coil bobbin 5 has a height dimension (dimension in the width direction in FIG. 11) that is substantially the same as the high voltage coil bobbin 4. The low voltage coil bobbin 5 is formed with a concave groove 501 for winding the secondary winding on the outer peripheral side surface, and the shape of the hole portion of the low voltage coil bobbin 5 is formed into a rounded rectangular shape (see FIG. 10). The reason why the hole portion of the low-voltage coil bobbin 5 has a rounded rectangular shape is that, as shown in FIG. 15, the high-voltage coil bobbin 4 is fitted into the hole portion.

  The two side walls 502 and 503 constituting both wall surfaces of the concave groove 501 have a rounded rectangular shape when viewed from the front or the back. The dimension (L4 (length in the longitudinal direction) × W4 (length in the short direction)) of the hole portion of the side wall 502 on the front side (hereinafter referred to as “first side wall 502”) is the high voltage coil bobbin 4 The size is slightly larger than the dimension (L2 × W2) on the outer peripheral side of the second side wall 403. The dimension on the outer peripheral side of the side wall 502 (L3 (length in the longitudinal direction) × W3 (short) The length in the hand direction)) is set to be approximately the same as the dimension (L1 × W1) on the outer peripheral side of the first side wall 402 of the low-voltage coil bobbin 5 (see FIG. 3).

  Two long sides in the opposite-side relationship between the inner peripheral side surface of the two short-side portions 5A (see FIG. 10; hereinafter referred to as “first opposite-side portion 5A”) and the high-voltage coil bobbin 4 in the opposite-side relationship of the low-voltage coil bobbin 5 The inner peripheral side surface of the portion 5B (see FIG. 10, hereinafter referred to as “second opposite side portion 5B”) is a flat surface (see FIG. 14). This is because the high voltage coil bobbin 4 is fitted into the hole portion of the low voltage coil bobbin 5.

  In the following description, for convenience of description, the long side portions of the second opposite side portion 5B of the low-voltage coil bobbin 5 may be referred to as “leg portions 5B”.

  A rear side wall 503 (hereinafter referred to as “second side wall 503”) is used to fit the second side wall 403 of the high-voltage coil bobbin 4 when the high-voltage coil bobbin 4 is fitted into the low-pressure coil bobbin 5 in the hole portion. A fitting portion 503A (see FIGS. 10 and 14) is formed. The fitting portion 503A is formed in a ring shape along the inner periphery of the hole of the second side wall 503. The fitting portion 503A is formed by extending the wall surface of the second side wall 503 by a predetermined dimension inside the hole.

  On the inner surface of the fitting portion 503A (the surface facing the second side wall 403 of the high voltage coil bobbin 4 when the high voltage coil bobbin 4 is fitted in the hole of the low voltage coil bobbin 5), a narrow groove along the inner periphery of the hole 5031 and 5032 (see FIGS. 10 and 14) are provided. The grooves 5031 and 5032 are provided with a flange 4031 (see FIG. 7) and an insulation reinforcing portion 410B (see FIG. 7) provided on the first side wall 402 of the high voltage coil bobbin 4 when the high voltage coil bobbin 4 is fitted into the hole of the low voltage coil bobbin 5. Reference) is a groove for fitting.

  The fitting portion 503 </ b> A is provided with four notches 504 at two short sides of the second side wall 503. These notches 504 are eight notches 408 formed in two short side portions of the second side wall 403 of the high voltage coil bobbin 4 when the high voltage coil bobbin 4 is fitted into the hole of the low voltage coil bobbin 5. This is to prevent the second side wall 503 from being blocked. That is, the eight notches 504 are for preventing the insulating oil from entering and exiting the concave groove 401 of the high-voltage coil bobbin 4 when the transformer is manufactured.

  The widths of the eight notches 504 are substantially the same as the eight notches 504 provided on the second side wall 503. Also, the four notches 504 in one short side portion (the upper short side portion in FIG. 10) of the second side wall 503 are when the high voltage coil bobbin 4 is fitted into the hole of the low voltage coil bobbin 5. One short side of the second side wall 503 is arranged such that the four notches 408 provided in the upper short side portion of the second side wall 403 of the high voltage coil bobbin 4 overlap with the four notches 504, respectively. It is provided in the side part. Further, the four cutouts 504 in the other short side portion (the lower short side portion in FIG. 10) of the second side wall 503 are when the high voltage coil bobbin 4 is fitted in the hole of the low voltage coil bobbin 5. In addition, four notches 408 provided on the second side wall 403 of the high-voltage coil bobbin 4 are provided on the other short side portion of the second side wall 503 so as to overlap with the four notches 504, respectively. ing.

  Support portions 505A and 505B (see FIG. 11) are provided in pairs on one short side portion (FIG. 10 is the upper short side portion) of the first side wall 502 and the second side wall 503, respectively. It has been. The two support portions 505A and 505B are plate-like members for attaching the tap changer TL. The support portions 505A and 505B are provided on the first side wall 502 and the second side wall 503 by integral molding of resin. The support portion 505A is formed so that the plate member protrudes outward from the outer periphery of the first side wall 502 (in FIG. 11, the plate member protrudes upward from the upper end of the first side wall 502). Similarly, the support portion 505B is formed so that the plate member protrudes outward from the outer periphery of the second side wall 503 (in FIG. 11, the plate member protrudes upward from the upper end of the second side wall 503). .

  A winding lead-out portion 506 for pulling out the secondary winding is provided at an appropriate position on the portion of the first side wall 502 where the support portion 505A is provided. The winding lead portion 506 is formed by a notch extending from the upper end of the first side wall 502 to the bottom surface 5011 of the groove 501.

  The concave groove 501 has a shape (rectangular cross-sectional shape) in which both inner wall surfaces rise perpendicularly to the bottom surface 5011 of the concave groove 501 (see FIG. 11). At the four corners of the low-voltage coil bobbin 5, similarly to the high-voltage coil bobbin 4, guide grooves 5012 (see FIGS. 11 to 13) that guide the winding position for winding the secondary winding on the bottom surface 5011 of the concave groove 501. ) Is provided. The guide groove 5012 is a groove whose cross-sectional shape having a groove width shorter than ½ of the diameter of the secondary winding is an arc shape.

  Next, the winding method of the secondary winding to the concave groove 501 of the low voltage coil bobbin 5 will be briefly described.

  The secondary winding is wound around the concave groove 501 with a multilayer structure. The secondary winding is wound in an aligned manner from the first side wall 502 side to the second side wall 503 with one end portion (portion serving as a lead wire) drawn out from the winding lead portion 506 to the outside of the low voltage coil bobbin 5. The The secondary winding is folded at the second side wall 503, and is wound up to the first side wall 502 using a depression between the windings formed on the upper surface of the first layer of the secondary winding as a guide. After that, the secondary winding is folded each time it reaches the inner wall surface of the second side wall 503 and the first side wall 402 with the depression between the windings formed above the windings of each layer as a guide. It is wound until the number reaches a predetermined number. Then, the other end of the secondary winding (portion serving as the lead wire) is drawn out of the low-voltage coil bobbin 5 from the winding lead-out portion 506.

  The high voltage coil 21 produced by aligning the primary winding in the concave groove 401 of the high voltage coil bobbin 4 is compared with the low voltage coil 22 produced by aligning the secondary winding in the concave groove 501 of the low voltage coil bobbin 5. As shown in FIG. 15, the high voltage coil bobbin 4 is fitted into the hole portion of the low voltage coil bobbin 5 from the front side and integrated.

  When the back side of the high-voltage coil bobbin 4 is fitted into the hole portion of the low-voltage coil bobbin 5 from the front side of the low-voltage coil bobbin 5, the peripheral portion of the second side wall 503 of the high-voltage coil bobbin 4 is It contacts the fitting portion 503A. Thereafter, when the high-voltage coil bobbin 4 is further pushed into the low-voltage coil bobbin 5 side, as shown in FIG. 16, the flange portion 4031 formed on the outer surface of the peripheral portion of the second side wall 503 and the insulation reinforcing portion 410B (projection strip member) ) Are respectively fitted in the grooves 5031 and 5032 of the fitting portion 503A, and the high-voltage coil bobbin 4 is fixed to the low-voltage coil bobbin 5. Thereby, the coil part 2 by which the low voltage coil 22 is concentrically arranged outside the high voltage coil 21 is produced.

  Next, the operation and effect of the insulation reinforcing portion 410 which is a characteristic configuration of the high voltage coil bobbin 4 according to the present embodiment will be described. As described above, the high-voltage coil bobbin 4 according to the present embodiment is provided with the two types of insulating reinforcing portions 410, that is, the insulating reinforcing portion 410A and the insulating reinforcing portion 410B. In the following description, in order to distinguish between the two insulation reinforcement portions 410A and 410B, the insulation reinforcement portion 410A is referred to as a “first insulation reinforcement portion 410A”, and the insulation reinforcement portion 410B is referred to as a “second insulation reinforcement portion 410B”. I will explain.

  First, the operation and effect of the first insulation reinforcing portion 410A will be described with reference to FIG.

  FIG. 17 is a cross-sectional view of the high voltage coil 21 cut at the position of the notch 408A. In addition, although the primary winding is wound in multiple layers in the concave groove 401 of the high voltage coil bobbin 4, FIG. 17 shows a part of the primary winding for convenience of drawing. Moreover, in FIG. 17, the part of 3 A of iron core end surfaces when the iron core 3 is attached to two leg parts of the coil part 2 is drawn with the virtual line.

In the circuit configuration shown in FIG. 2, the ground voltage at the position connected to the high voltage bushing BS1 (+) or the high voltage bushing BS1 (−) in the primary winding constituting the high voltage coil 21 is the highest. For example, the state (circuit state shown in FIG. 2) of the tap changer TL connects the common terminal P _c and tap terminal P _1, an end portion or divided windings is connected to the tap terminal P ₁ of Komaki line 212a The voltage to ground at the end connected to the high voltage bushing BS1 (−) of 211b is the highest.

A high voltage of 6000 [V] to 7000 [V] is applied to the high voltage bushing BS1 (+) at the time of electric power transmission. It becomes so, the end or dividing the winding 211b of the high-voltage bushing BS1 is connected to the tap terminal P ₁ of Komaki line 212a - will be ultra high pressure end connected to is applied ().

For example, the end connected to the tap terminal P _{1 of the} small winding 212 a is drawn out of the high voltage coil bobbin 4 from the notch 408 A of the concave groove 401 of the high voltage coil bobbin 4. For this reason, in the concave groove 401 of the high voltage coil bobbin 4 when the ultra high voltage superimposed with the lightning surge voltage is applied to the high voltage bushing BS1 (+), the small winding 212a is drawn into the concave groove 401 from the notch 408A. Accordingly, the voltage at the winding start position P where the aligned winding is performed becomes the highest.

Therefore, as described above, to design the resin thickness of the high-pressure coil bobbins 4 in as much as possible minimum resin thickness D _min, the position P of the groove 401 of the high-pressure coil bobbins 4 in the following provisions of withstand voltage V _T It is necessary to design insulation reinforcement so that discharge does not occur in the path from the core surface 3A of the wound core 3 to the bobbin surface.

In the above description, a case has been described in which the tap changer TL connects the common terminal P _c and tap terminal P _1, tap changer TL is a common terminal P _c and tap terminal P ₂ to P ₄ The same applies when connected. If the common terminal _{P c} connecting the tap terminal _P 2 to P _4, the position P is Komaki line 212b that discharge occurs, Komaki line 212c, becomes a winding start position of the divided windings 211a, Since the winding start positions of these windings 212b, 212c, and 211a are the positions where the notches 408B, 408C, and 408D of the concave groove 401 are provided, the positions near the winding start position P of the small winding 212a and Become.

Therefore, if the insulation reinforcement is designed for the creeping distance of the path along the bobbin surface from the winding start position P of the small winding 212a to the core end surface 3A of the winding core 3, the tap terminal connected to the common terminal _Pc is set to P even when switching to ₂ to P ₄ can be obtained the effect.

  The same applies to the end portion of the divided winding 211b connected to the high voltage bushing BS1 (-). That is, the path along the bobbin surface from the position where the end connected to the high voltage bushing BS1 (−) of the divided winding 211b is drawn from the notch 408E of the concave groove 401 of the high voltage coil bobbin 4 to the core end surface 3A of the wound core 3 If insulation reinforcement is designed for the creepage distance, insulation reinforcement can be performed.

  In the high-voltage coil bobbin 4 according to the present embodiment, as shown in FIG. 17, between the notch 408 of the first opposite side portion 4A and the hole (the tip of the curved inner peripheral side surface inside the first opposite side portion 4A). 410A of the 1st insulation reinforcement part which consists of a rod-shaped convex piece of a part) is provided. The path along the bobbin surface from the position P of the recessed groove 401 to the core end surface 3A of the wound core 3 when the first insulation reinforcing portion 410A is not provided is a path R1 indicated by an imaginary line. When the reinforcing portion 410A is provided, a route along the bobbin surface from the position P of the groove 401 to the core end surface 3A of the wound core 3 is a route R2 (route indicated by a thick solid line) that bypasses the surface of the convex piece. Accordingly, the creepage distance LS of the path R2 from the position P when the first insulation reinforcing portion 410A is provided to the core end surface 3A of the wound core 3 can be made longer than the creepage distance of the path R1 indicated by the phantom line. .

  Thus, by providing the notch 408 in the first opposite side portion 4A of the high-voltage coil bobbin 4, the creepage distance of the path from the position P to the core end surface 3A of the wound core 3 is shortened, and even if the insulation strength is reduced, The insulation strength can be reinforced by providing one insulation reinforcing portion 410A.

  In the present embodiment, the first insulating reinforcing portion 410A made of one convex piece is provided between the notch 408 of the first opposite side portion 4A and the hole, but the first insulating reinforcing portion 410A is As shown in FIG. 18A, a plurality of convex pieces may be used. Further, as shown in FIG. 18B, the first insulation reinforcing portion 410A may be constituted by a groove instead of the convex piece. And the cross-sectional shape of a convex piece or a groove | channel is not limited to a rectangle, Arbitrary shapes, such as a triangle, an ellipse, and a trapezoid, are employable.

  Furthermore, as shown in FIG. 18C, the first insulation reinforcing portion 410A may be constituted by a concavo-convex portion in which a concave portion and a convex portion are repeated. Also in this case, the cross-sectional shape of the concavo-convex portion is not limited to the sine wave shape, and any wave shape such as a triangular shape or a rectangular wave shape can be adopted. Further, the position where the first insulation reinforcing portion 410A is provided can be set to an arbitrary position as long as the creepage distance LS is long.

  Next, the operation and effect of the second insulation reinforcing portion 410B will be described with reference to FIG.

  FIG. 19 is a cross-sectional view of the leg portion 4 </ b> B of the high voltage coil 21. In addition, although the primary winding is arranged in multiple layers in the concave groove 401 of the high voltage coil bobbin 4, FIG. 19 shows a part of the primary winding for convenience of drawing. Further, in FIG. 19, the iron core 3 </ b> A when the iron core 3 is attached to the leg portion of the coil portion 2 is drawn with virtual lines.

  In the leg portion 4B of the high-voltage coil bobbin 4, the discharge path from the winding start position P of the small winding 212a on the bottom surface 405 to the iron core B along the bobbin surface is a path R3 indicated by a bold line in FIG. The discharge path from the winding start position Q of the split winding 211b on the bottom surface 405 to the iron core B along the bobbin surface is as a path R4 indicated by a thick line in FIG.

  In the actual use state (energized state), the creepage distances of the discharge paths R3 and R4 starting from the position P or the position Q may be designed. However, in the “non-grounding test” of the lightning impulse test of the transformer, the high-voltage side is connected in a lump, and the low-voltage side, the iron core, and the earth of the metal fitting are all grounded and a predetermined test voltage is applied. Under the test conditions, the creeping distance of the discharge steep road starting from the position U in FIG. 19 is the shortest. Therefore, in the design of the creepage distance of the high-voltage coil bobbin 4, the creepage distance of the discharge ramp with the position U as the starting point is designed to be greater than the minimum creepage distance required.

  Since the height h2 from the bottom surface 405 of the second side wall 403 of the high voltage coil bobbin 4 is lower than the height h1 from the bottom surface 405 of the first side wall 402, even if the creepage distance of the route R3 is sufficient, The creepage distance may not be sufficient.

  In the high voltage coil bobbin 4 according to the present embodiment, the outer surface of the peripheral portion of the second side wall 403 is fitted to the fitting portion 503A of the low voltage coil bobbin 5, and is disposed outside the high voltage coil bobbin 4 and the high voltage coil bobbin 4. The low voltage coil bobbin 5 is fixed. For this reason, the creeping distance of the path R4 is increased by using a protrusion fitting member to the fitting portion 503A of the second side wall 403.

  As shown in FIG. 19, the path R4 passes through the surface of the flange 4031 which is a fitting member from the inner wall surface of the second side wall 403 of the groove 401 to the fitting portion 503A, and is outside the second side wall 403. After coming out to the wall surface, it reaches the iron core 3 through the outer wall surface, but in this embodiment, a protruding insulation reinforcement portion 410B is added on the path R4 of the outer wall surface of the second side wall 403. With this configuration, the path R4 has a creepage distance LS that is increased by the amount of passage through the surface of the convex insulation reinforcing portion 410B, and the insulation on the second side wall 403 is reinforced.

  As described above, the insulation reinforcing portion 410B can reinforce the fitting and fixing strength between the high-voltage coil bobbin 4 and the low-voltage coil bobbin 5, and the second side wall from which the height h2 from the bottom surface 405 of the concave groove 401 cannot be sufficiently obtained. There is an effect that the insulation at 403 can be reinforced.

  In the present embodiment, only one protrusion is provided as the insulation reinforcing portion 410B. However, as shown in FIG. 20A, the insulation reinforcing portion 410B may be formed of a plurality of protrusions. . Moreover, as shown in FIG.20 (b), you may comprise the insulation reinforcement part 410B instead of a protruding item | line with a concave strip. And the cross-sectional shape of a protrusion or a groove is not limited to a rectangle, Arbitrary shapes can be employ | adopted.

Furthermore, as shown in FIG. 20C, the insulation reinforcing portion 410 </ b> B may be configured by an uneven strip member (a member having a corrugated cross-sectional shape) in which convex strips and concave strips are repeated. In this case as well, the cross-sectional shape of the concavo-convex portion is not limited to the rectangular wave shape, and any wave shape such as a sine wave shape can be adopted.

As described above, according to the high voltage coil bobbin 4 according to the present embodiment, a rod-like protrusion is formed on the portion of the first opposite side portion 4A between the notch 408 and the window 409 and the core end surface 3A of the iron core 3. The insulation reinforcement part 410A which consists of a piece is provided, and the insulation reinforcement part 410B which consists of a protrusion with a rectangular cross section is provided on the outer surface of the upper part of the second side wall 403 so as to circulate along the outer periphery of the high voltage coil bobbin 4. Therefore, the insulation by the creepage distance of said part can be reinforced. Thereby, the resin thickness of the high voltage coil bobbin 4 can be designed to the minimum resin thickness _Dmin , and the high voltage coil bobbin 4 can be reduced in size, weight, and cost. As a result, it is possible to reduce the size, weight, and cost of the coil unit 2 using the high-voltage coil bobbin 4 and the low-voltage coil bobbin 5 and the transformer using the coil unit 2.

  In the above embodiment, the dividing wall 406 is provided in the concave groove 401 of the high-voltage coil bobbin 4. However, the dividing wall 406 is not necessarily required, and the present invention is also applied to a high-voltage coil bobbin without the dividing wall 406. be able to.

  In the above embodiment, since the voltage output to the low voltage coil wound around the low voltage coil bobbin 5 is low voltage, the insulation reinforcing portion 410 is provided only on the high voltage coil bobbin 4. In the case where there is a place where insulation reinforcement by the creepage distance is required, an insulation reinforcement portion including a convex portion or a concave portion may be provided at that location.

  In said embodiment, although the coil part 2 used for the transformer main body 1 was demonstrated, this invention is not limited to a transformer, It is widely applied to the static induction apparatus using the coil part which has the same structure. Can be used.

DESCRIPTION OF SYMBOLS 1 Transformer body 2 Coil part 21 1st coil (high voltage coil)
211 Main winding 212 Winding adjustment winding 3 Iron core 4 First coil bobbin (high voltage coil bobbin)
4A 1st opposite side part 4B 2nd opposite side part 401 Concave groove 401A 1st concave groove 401B 2nd concave groove 402 1st side wall 403 2nd side wall 4031 ridge part 404 Bottom surface of 1st concave groove 404A Guide Groove 405 bottom surface of second concave groove 405A guide groove 406 dividing wall 407A groove 407B winding support portion 4071 bottom surface of groove 408 notch 409 window 410, 410A, 410B insulation reinforcing portion 5 second coil bobbin (low voltage coil bobbin)
5A First opposite side portion 5B Second opposite side portion 501 Concave groove 5011 Concave groove bottom surface 5012 Guide groove 502 First side wall 503 Second side wall 503A Fitting portion 504 Notch 505A, 505B Support portion 505 Second concave Bottom of groove 506 Winding lead

Claims (5)

A coil bobbin in which a groove is provided on the entire outer peripheral side surface of the annular frame, and a coil is wound around the groove to produce an annular coil.
An insulation reinforcing portion for reinforcing insulation between the coil and the iron core attached to the coil is provided on the outer surface of the side wall of the concave groove ,
The frame has a rectangular frame shape,
The iron core is attached to a first frame side portion composed of a pair of opposite sides of the frame body,
The insulation reinforcing portion is a hook-like convex portion that protrudes along the inner periphery of the frame body on the inner peripheral side surface of the second frame side portion that consists of a pair of opposite sides of the frame body. including,
Coil bobbin.   The coil bobbin according to claim 1, wherein the insulation reinforcement portion reinforces the insulation by increasing a creepage distance between the coil and the iron core. The side wall of the groove is composed of a first side wall and a second side wall whose height from the bottom surface of the groove is lower than the height of the first side wall,
The said insulation reinforcement part is an outer surface of the upper part of a said 2nd side wall, The 1 or 2 or more collar-shaped convex part protruded along the outer periphery of the said frame is Claim 1 or Claim. The coil bobbin according to 2 . The coil produced by winding a coil | winding to the concave groove of the coil bobbin as described in any one of Claims 1 thru | or 3 . A coil part in which a second coil is concentrically arranged outside the first coil;
An iron core attached to one or both of the two leg portions in the opposite side relationship of the coil portion,
The first coil is produced by winding a coil around a concave groove of the coil bobbin according to any one of claims 1 to 3 .
The second coil is manufactured by winding a winding around a concave groove of a second coil bobbin that is externally mounted on the outside of the coil bobbin by fitting the coil bobbin.
Transformer.

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