JP2016129174A - Transformer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a transformer capable of reducing a variation of output characteristics.SOLUTION: A transformer 20 as an embodiment comprises: a step part 45 that positions an insertion depth of a path core unit 60 to at least one of coil bobbins 40 for a primary coil 51 or a secondary coil 52. In the path core unit 60, a path core 63 is sandwiched in a sandwiched shape by a plurality of insulation plates 61 determined to have a predetermined dimension and is fixed. Thus, even if a size or the insertion depth of the path core 63 can be changed by, for example, difference of an electric specification of the transformer 20, a tip in an insertion direction of the path core unit 60 contacts to the step part 45, and the insertion depth is uniformly determined, when inserting the path core unit 60 between the coil bobbins 40 for the primary coil 51 and the secondary coil 52. Therefore, the position of the insertion depth of pass core 63 can be properly held, and the variation of output characteristics of the transformer 20 can be suppressed.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a transformer having a leaking iron core.

  A transformer with a leaking iron core, that is, a magnetic leakage transformer, prevents current from flowing to the secondary side when the current flows through the coil (winding) on the secondary side. Works. Such a transformer is also called a “leakage transformer”. For example, as a prior art regarding a magnetic leakage transformer for three-phase alternating current, there is a “transformer” disclosed in Patent Document 1 below.

  In this technology, the U-phase, V-phase, and W-phase AC voltages are input to the primary coil, and the iron core yoke and three leg (leg) magnetic paths through which the magnetic flux passes are transformed. A U-shaped path core (leakage iron core) that does not contribute to the action is placed so as to straddle the middle leg. That is, the pass core is inserted so that the U-shaped protrusion is inserted into each of the two iron core windows sandwiched between the three legs. As a result, a part of the magnetic flux passing through the legs on both sides can be bypassed via the U-shaped path core and returned to the primary side coil, thus making it possible to equalize the current generated in the secondary side coil.

JP-A-8-8131

  The prior art disclosed in Patent Document 1 described above suppresses the current imbalance of the secondary side coil excited for each phase of the three-phase alternating current and makes the current generated in the secondary side coil uniform. Is. However, as described in the same document, the current value of each phase of the secondary coil actually depends on the connection state of the load, the connection connection of the transformer, the variation in the electrical characteristics of the transformer, etc. There is not much that is the same (paragraph 0013 of Patent Document 1).

  On the other hand, the insertion position, size, and thickness of the path core (leakage core) inserted into the iron core window has a significant effect on the output characteristics in which the output voltage decreases as the secondary coil current increases. Can give. In particular, the position in the vertical direction with respect to the iron core window, that is, the position of the insertion depth of the pass core, is easily influenced by the size of the surface extending in the magnetic flux passage direction (leakage magnetic path formation direction) of the pass core, and has an effect on the output characteristics. large.

  For this reason, when the size and insertion depth of the pass core can be changed due to differences in the electrical specifications of the transformer, it is better to maintain the stabilization of the output characteristics by making the insertion position of the pass core appropriate. In many cases, priority is given to equalization of the current generated in the side coil.

  The present invention has been made to solve the above-described problems, and an object thereof is to provide a transformer that can suppress variations in output characteristics.

  In order to achieve the above object, a transformer according to the present invention includes a plurality of legs extending in the same direction in a comb-like shape, an iron core having yoke portions that close the tips of the plurality of legs, and the plurality of legs. A first bobbin having a first bobbin inserted into each base end side and a first winding portion having a first winding wound around these first bobbins, and inserted into the respective distal ends of the plurality of leg portions. A second winding portion having a second bobbin and a second winding wound around these second bobbins, and the plurality of legs interposed between the first winding portion and the second winding portion. A leakage iron core that forms a leakage magnetic path through which a leakage magnetic flux flows between adjacent legs of the portion, and at least one of the first bobbin and the second bobbin has an insertion depth of the leakage iron core A technical feature is that a step portion for determining the position of the step is formed.

  In the transformer of the present invention, at least one of the first bobbin around which the first winding is wound and the second bobbin around which the second winding is wound is formed with a step portion that determines the insertion depth of the leaking iron core. Has been. As a result, for example, even if the size and insertion depth of the leaking iron core can be changed due to differences in electrical specifications of the transformer, the position of the insertion depth of the leaking iron core can be maintained appropriately. Become.

  In the transformer of the present invention, the first bobbin and / or the second bobbin in which the stepped portion is formed are orthogonal to the insertion depth direction of the leaking iron core. The present invention is characterized in that a guide portion for guiding the position is formed.

  As a result, in addition to the position of the insertion depth of the leaking iron core, the insertion position of the leaking iron core can be kept appropriate for the position in the direction orthogonal to the insertion depth direction. Note that “and / or” is an expression that can select either “and” or “or”.

  Furthermore, the transformer of the present invention is the transformer of each of the above inventions, wherein the leakage iron core is sandwiched between a plurality of insulating plates having a predetermined size, and the leakage between the insulating plates It is technically characterized in that it is positioned and fixed in the insertion depth direction of the iron core and in the direction perpendicular thereto.

  As a result, the size of the surface and the thickness (height) of the leakage core that expands in the magnetic flux passage direction (leakage magnetic path formation direction) may vary depending on the electrical specifications of the transformer. However, the size of the insulating plate that sandwiches the leaked iron core in a sandwich shape is set to a predetermined dimension and does not vary. Therefore, various first bobbins and second bobbins are prepared according to the size of the leaking iron core by forming a stepped portion and a guide portion on the first bobbin and the second bobbin according to the size of the insulating plate. It is possible to cope with one type of first bobbin and second bobbin.

  In the present invention, since the insertion position of the leaking iron core can be properly maintained, variations in the output characteristics of the transformer can be suppressed.

It is a perspective view showing composition of a transformer concerning an embodiment of the present invention. It is a top view which shows the structure of the transformer of this embodiment. It is a front view which shows the structure of the transformer of this embodiment. It is a circuit diagram which shows the structure of the transformer of this embodiment. 5A is a cross-sectional view taken along line 5A-5A shown in FIG. 3, and FIG. 5B is a cross-sectional view taken along line 5B-5B shown in FIG. FIG. 6 corresponds to the cross-sectional view shown in FIG. 5 (B) and is an explanatory view showing a process of inserting a pass core unit. FIG. 7A is a perspective view showing the configuration of the pass core unit, and FIG. 7B is an exploded view showing the configuration of the pass core unit. FIG. 8A is a perspective view showing the configuration of the coil bobbin, and FIG. 8B is an explanatory diagram showing the positional relationship between the coil bobbin and the pass core unit. FIG. 9A is a plan view, FIG. 9B is a left side view, FIG. 9C is a front view, FIG. 9D is a rear view, and FIG. E) is a bottom view. 10A is a cross-sectional view taken along the line 10A-10A shown in FIG. 9A, and FIG. 10B is a cross-sectional view taken along the line 10B-10B shown in FIG. 9A. 9C is a cross-sectional view taken along the line 10C-10C shown in FIG. 9A, FIG. 10D is a cross-sectional view taken along the line 10D-10D shown in FIG. 9A, and FIG. It is sectional drawing by the 10E-10E line shown to 9 (A). FIG. 11A is a cross-sectional view illustrating a configuration example of a transformer when a modified coil bobbin is used, and corresponds to FIG. FIG. 11B is a cross-sectional view taken along the YZ plane from the center in the X-axis direction of the EI core of the transformer. 12A is a perspective view showing the configuration of the coil bobbin of the transformer shown in FIG. 11, and FIG. 12B is an explanatory view showing the positional relationship between the coil bobbin and the pass core unit. It is a figure which shows the external appearance structure of the coil bobbin of the trans | transformer shown in FIG. 11, FIG. 13 (A) is a top view, FIG. 13 (B) is a left view, FIG. 13 (C) is a front view, FIG. FIG. 13E is a rear view, and FIG. 14A is a cross-sectional view taken along line 14A-14A shown in FIG. 13A, and FIG. 14B is a cross-sectional view taken along line 14B-14B shown in FIG. (C) is a sectional view taken along line 14C-14C shown in FIG. 13 (A), FIG. 14 (D) is a sectional view taken along line 14D-14D shown in FIG. 13 (A), and FIG. FIG. 14 is a cross-sectional view taken along line 14E-14E shown in FIG.

  Hereinafter, embodiments of a transformer of the present invention will be described with reference to the drawings. First, the structure of the transformer 20 according to the embodiment of the present invention will be described with reference to FIGS. 1 is a perspective view showing the configuration of the transformer 20, FIG. 2 is a plan view showing the configuration of the transformer 20, FIG. 3 is a front view showing the configuration of the transformer 20, and FIG. 4 is a circuit showing the configuration of the transformer 20. Figures are respectively shown.

  As shown in FIG. 1, the transformer 20 mainly includes an iron core portion 21, a primary winding portion 23, a secondary winding portion 25, and a leaking iron core portion 27. The transformer 20 of the present embodiment is a leakage transformer (magnetic leakage transformer) for three-phase AC. Therefore, in addition to the three primary windings 23 and the three secondary windings 25 corresponding to each of the U-phase, V-phase, and W-phase of the three-phase alternating current, the leakage core 27 is provided. doing.

  In the present embodiment, the iron core portion 21 is configured to exhibit a shape as if a Japanese character “day” is lying on its side. For example, an E-type core having three leg portions 31, 32, 33, and an I-type core that is a yoke portion 34 that closes the open side ends (tips) of these three leg portions 31-33, The iron core portion 21 is configured by combining the above. Therefore, in the present embodiment, it should be noted that the iron core portion 21 may be expressed as “EI core 30”. A window portion 35 is formed between the leg portion 31 and the leg portion 32, and a window portion 36 is formed between the leg portion 32 and the leg portion 33.

  The iron core 21 is formed by laminating a plurality of electromagnetic steel plates such as silicon steel plates. These electromagnetic steel sheets are, for example, laminated with E-shaped E-shaped steel sheets and I-shaped I-shaped steel sheets that are alternately changed in direction so that the E-shape is reversed every few sheets. The iron core 21 is pressed in the stacking direction by unillustrated bolts and nuts so that the stacked state can be maintained.

  The core part 21 configured in this manner has a primary winding part 23 and a secondary winding part 25 wound around its leg parts 31 to 33. In the present embodiment, for example, the primary winding portion 23 is disposed on the upper side of the iron core portion 21 (the Z-axis arrow side in the coordinate system shown in FIG. 1), and the lower side of the iron core portion 21 (in the coordinate system shown in FIG. 1). The secondary winding portion 25 is disposed on the base side of the Z axis). 2 and 3, the primary winding portion 23 is configured by winding a primary coil around a coil bobbin 40, and the secondary winding portion 25 is configured as a coil bobbin as shown in FIG. The secondary coil is wound around 40.

  Note that lead wires with terminals represented by reference numerals 53 a, 53 b, and 53 c indicate input lines connected to the primary coil constituting the primary winding portion 23. Further, lead wires with terminals represented by reference numerals 54 a, 54 b and 54 c indicate output lines connected to the secondary coil constituting the secondary winding portion 25. It should be noted that the primary coil and the secondary coil are not indicated by reference numerals in FIGS. 1 to 3 because the surface of the wound wire is covered with the insulating paper 59.

  As shown in FIG. 2, when the transformer 20 is viewed from the upper surface, the positions of the three primary windings 23 and the input lines 53a, 53b, 53c and the output lines 54a, 54b, 54c arranged in the front-rear direction thereof. I understand the relationship. As shown in FIG. 3, when the transformer 20 is viewed from the front, a gap SP is formed between the primary winding portion 23 and the secondary winding portion 25, and the window portion 35, of the gap SP, It can be seen that the path core unit 60 is disposed inside the inner space 36. The pass core unit 60 will be described in detail later. In FIG. 2 and FIG. 3, the input terminal connected to each of the input lines 53a, 53b and 53c is denoted by reference numeral 57, and is connected to each of the output lines 54a, 54b and 54c. Reference numeral 58 is attached to the output terminal.

  Such a transformer 20 can be expressed by a circuit diagram (connection diagram) as shown in FIG. In this figure, corresponding to each of the U-phase, V-phase, and W-phase, three primary coils 51 wound around the coil bobbin 40 and constituting the primary winding portion 23, and wound around the coil bobbin 40 are shown. Three secondary coils 52 constituting the secondary winding portion 25 are expressed by coil circuit symbols. The three input lines 53a are connected to the primary coil 51 when the input voltage is different, and an appropriate input corresponding to the number of turns of the primary coil 51 according to the voltage (for example, 200V, 220V, 240V). This is to make the terminal selectable. The same applies to the input lines 53b and 53c.

  Each of the primary coil 51 and the secondary coil 52 is star-connected to three coils. That is, for the primary coil 51, the end portions on the side where the input lines 53a, 53b, and 53c are not connected are connected together (reference numeral 55), and also for the secondary coil 52, the output lines 54a and 54b are connected. , 54c are connected together at their ends (reference numeral 56). These are shown as the input side connection part 55 and the output side connection part 56 in FIG. 2 and FIG.

  When the transformer 20 is represented by its equivalent circuit, the leakage core 27 (see FIG. 4) is connected to the input lines 53a, 53b, 53c of the primary coil 51 or the output lines 54a, 54b, 54c of the secondary coil 52 shown in FIG. The choke coil corresponding to the leakage inductance by the pass core of the pass core unit 60 is represented as being connected in series.

  Next, the path core unit 60 inserted into the gap SP between the primary winding portion 23 and the secondary winding portion 25 will be described with reference to FIGS. FIG. 5 shows a cross-sectional view of the transformer 20. 5A shows a cross-sectional view taken along line 5A-5A shown in FIG. 3, and FIG. 5B shows a cross-sectional view taken along line 5B-5B shown in FIG. FIG. 6 shows an explanatory view showing the process of inserting the pass core unit 60 corresponding to the cross-sectional view shown in FIG. FIG. 7A shows a perspective view showing the configuration of the pass core unit 60, and FIG. 7B shows an exploded view showing the configuration of the pass core unit 60.

  As shown in FIG. 5A, in the transformer 20 of this embodiment, the insertion depth of the pass core unit 60 can be positioned on the coil bobbin 40 constituting the primary winding part 23 and the secondary winding part 25. A step 45 is provided. In other words, in this embodiment, the stepped portion 45 formed by providing the thick portion 46 on a part of the coil bobbin 40 is used for alignment of the pass core unit 60. Here, the path core unit 60 will be described, and the stepped portion 45 will be described in detail later with reference to FIGS. 5 and 6.

  As shown in FIG. 5B and FIG. 7, a pass core 63 as a leaking iron core portion 27 is sandwiched between two insulating plates 61 in the pass core unit 60. The pass core 63 is formed by laminating one core plate 65 or a plurality of core plates 65. The core plate 65 is formed by, for example, forming an electromagnetic steel plate such as a silicon steel plate into a strip shape or a rectangular shape.

  In the present embodiment, the size of the surface of the core plate 65 extending in the magnetic flux passage direction (leakage magnetic path formation direction) is between the leg portion 31 and the leg portion 32 of the EI core 30 or the EI core 30. Between the leg part 32 and the leg part 33, it is set as what is necessary in order to be able to form the leakage magnetic path through which leakage magnetic flux flows. Specifically, the size (longitudinal direction, short direction) of the core plate 65 is determined based on the results of experiments and computer simulations so that desired characteristics of the output voltage and output current can be obtained according to the electrical specifications of the transformer 20. And thickness) and the material of the electrical steel sheet.

  The number of core plates 65 required is also set to a number necessary to form such a leakage magnetic path based on the results of experiments and computer simulations. When there are a plurality of core plates 65, a pass core 63 is configured by stacking the required number of core plates 65. The laminated core plates 65 are, for example, bound with an adhesive tape and fixed in a block shape. The core plate 65 is laminated to a thickness corresponding to an interval obtained by subtracting the thickness of two insulating plates 61 from the interval of the gap SP formed between the primary winding portion 23 and the secondary winding portion 25. Is acceptable. In other words, the gap SP is set to be equal to or greater than the maximum thickness of the path core unit 60 planned from the electrical specifications of the transformer 20.

  On the other hand, the insulating plate 61 covering the core plate 65 is obtained by, for example, laminating insulating paper (aramid insulating paper) made of an aramid (fully aromatic polyamide) polymer in a flat plate shape. The size is set to a predetermined size larger than the size of the surface of the insulating plate 61 that expands in the direction in which the leakage magnetic path is formed. Aramid polymer is excellent in durability, mechanical and electrical characteristics in a high temperature environment, and is also used for insulating paper 59 covering the coil surface of the transformer. In the present embodiment, the thickness of the core plate 65 is set in a range of 0.5 mm (millimeters) or more and 1.5 mm (millimeters) or less, for example.

  By aligning the longitudinal direction (or short direction) of the insulating plate 61 and the longitudinal direction (or short direction) of the pass core 63 so that the long sides of both are aligned on one side, two sheets are aligned. The insulating plate 61 sandwiches the path core 63 from both sides. Such alignment of the pass core 63 may be performed after being sandwiched between the insulating plates 61. When the alignment is completed, for example, as shown in FIG. 7A, the path core 63 is shifted to one side (one side of the long side) in the short direction of the insulating plate 61 between the two insulating plates 61. Be placed. In the pass core unit 60, in order to fix the pass core 63 aligned between the insulating plates 61 in the insulating plate 61, for example, a double-sided tape is applied to both surfaces of the pass core 63 on the plane side, or an adhesive, an insulating varnish, or the like is applied. The pass core 63 is attached to the insulating plate 61 by painting.

  In the present embodiment, the path core unit 60 configured in this way is used as a gap SP between the primary winding portion 23 and the secondary winding portion 25, that is, a coil bobbin 40 for the primary coil 51 and a coil bobbin for the secondary coil 52. Insert between 40. The path core unit 60 on the left side (Y-axis arrow side) in FIG. 5A represents a middle stage of insertion in the gap SP, whereas the right side in FIG. 5A. The path core unit 60 on the (Y-axis root side) represents the one after completion of insertion into the gap SP. It can be seen that the insertion end of the insulating plate 61 in the pass core unit 60 after the insertion is in contact with the stepped portion 45 of the coil bobbin 40.

  In the present embodiment, among the three legs 31 to 33 provided on the EI core 30, the path core unit 60 is positioned so that the core plate 65 is closest to the middle leg 32. doing. That is, in the pass core unit 60, as described above, the pass core 63 is disposed so as to be offset toward one side (one side of the long side) of the insulating plate 61 in the short direction. Therefore, in this embodiment, the path core unit 60 is inserted into the gap SP with the side of the path core 63 offset, that is, the side closer to the path core 63 facing the leg portion 32. Thereby, since the core plate 65 approaches the leg part 32 located in the middle of the three, the formation of the leakage magnetic path is stabilized.

  When the pass core unit 60 is inserted into the gap SP and the assembly of the transformer 20 is completed, the insulating varnish is applied to almost the entire surface of the transformer 20. At this time, the insulating varnish also enters the periphery of the pass core unit 60 inserted in the gap SP. Thereby, since the pass core unit 60 is fixed in the gap SP by drying and hardening of the insulating varnish, the pass core 63 (leakage iron core portion 27) of the pass core unit 60 is fixed at an appropriate position. Here, the configuration of the coil bobbin 40 will be described with reference to FIG. 8A is a perspective view showing the configuration of the coil bobbin 40, and FIG. 8B is an explanatory view showing the positional relationship between the coil bobbin 40 and the path core unit 60. . Note that the coil bobbin 40 with the top and bottom facing in opposite directions is shown in both figures of FIG.

  As shown in FIG. 8, the coil bobbin 40 can be used for any of the leg portions 31 to 33, and a part of the shape of the opening portion 49 of the square tube portion 41 is slightly smaller than the outer peripheral shape of the cross section of the leg portions 31 to 33. Is set to a small value. In the present embodiment, for example, the facing interval of the short sides of the opening 49 facing the longitudinal direction of the cross-sectional shape of the legs 31 to 33 is set slightly smaller than the longitudinal width of the legs 31 to 33. Yes. In this embodiment, a plurality of (three) linear grooves 42 are formed on the inner surface of the opening 49 in the short side direction. Thereby, compared with the case where such a linear groove 42 is not formed, the gap between the leg portions 31 to 33 and the coil bobbin 40 can be secured and the both can be firmly fixed by the insulating varnish entering the gap. I have to.

  At both ends of the square tube portion 41 where such an opening 49 is formed, an upper collar portion 43 and a lower collar portion 44 are formed that extend outward. In FIG. 8, since the top and bottom are reversed, the upper collar portion 43 is located on the lower side of the paper surface, and the lower collar portion 44 is located on the upper side of the paper surface. The difference between the upper flange portion 43 and the lower flange portion 44 is whether or not the stepped portion 45 and the thick portion 46 are formed. Both of the portions are provided with a notch portion 44a. It has a U shape. The notch 44a is used when the input lines 53a, 53b, 53c of the primary winding part 23 and the output lines 54a, 54b, 54c of the secondary winding part 25 are pulled out in the vertical direction (Z-axis direction). It is provided to prevent the part from becoming an obstacle (obstruction).

  In the present embodiment, in the lower collar portion 44, a thick portion 46 is provided in a part of the lower collar portion 44 where the notch portion 44a is not provided, and the pass core unit 60 in the thick portion 46 is disposed. A step 45 is formed so as to exclude (enclose) the range. As shown in FIGS. 5 and 6, only the coil bobbin 40 around which the primary coil 51 of the primary winding portion 23 is wound contributes to the positioning of the pass core unit 60 in the depth direction (X-axis direction). A transformer 20 ′ shown in FIG. 6 (A) is a stage before the insertion of the path core unit 60, and a transformer 20 ″ shown in FIG. 6 (B) is a path core in the arrow direction shown in FIG. 6 (A). It is a stage in the middle of inserting the unit 60. From these drawings, the position of the pass core unit 60 in the depth direction (the X-axis direction, the longitudinal direction of the pass core unit 60) is determined by the step portion 45. Understandable.

  The height (depth) of the stepped portion 45 is, for example, greater than or equal to the thickness of one insulating plate 61 constituting the pass core unit 60 and less than the thickness of two (for example, a thickness of 1.5). ) Is set. If the thickness of the insulating plate 61 is less than the thickness of one sheet, the insertion direction tip of the pass core unit 60 may not be in contact with the stepped portion 45. This is because the thickness of the lower flange portion 44 forming the portion 46 may be thicker than necessary, which may lead to an increase in manufacturing cost.

  In the present embodiment, the step 45 is provided on the lower flange 44 of the coil bobbin 40 of the primary winding part 23, and the step 45 is not provided on the upper flange 43 of the coil bobbin 40 of the secondary winding 25. Are the following two.

  (1) On the side where the output line 54a and the like of the secondary winding portion 25 are drawn out, that is, on the side where the cutout portion 44a is formed in the coil bobbin 40 for the secondary coil 52, the upward direction (the arrow direction of the Z axis) This is because a part of the output line 54a or the like that rises in the path becomes a hindrance (disturbance) when the pass core unit 60 is inserted, and the pass core unit 60 cannot be inserted into the gap SP.

  (2) When a step portion is formed on the upper flange portion 43 of the coil bobbin 40 of the secondary winding portion 25 in accordance with the step portion 45 of the lower flange portion 44 of the coil bobbin 40 of the primary winding portion 23, This is because the thick portion 46 is provided in the vicinity of the notch portion 44a of the portion 43, so that it is necessary to prepare two types of coil bobbins, leading to an increase in manufacturing cost.

  If the thickness of the pass core unit 60 is smaller (smaller) than the gap SP between the primary winding portion 23 and the secondary winding portion 25, the secondary winding in which the step portion 45 is not formed. The insulating plate 61 is inserted between the coil bobbin 40 of the portion 25 and the pass core unit 60 by an insufficient thickness. Thereby, it is suppressed that the position of the insertion depth of the pass core unit 60 positioned by the coil bobbin 40 of the primary winding part 23 fluctuates.

  The overall shape of the coil bobbin 40 configured as described above can be grasped from a perspective view shown in FIG. 8A, a plan view shown in FIG. 9 and the like, and a sectional view shown in FIG. FIG. 8 (A) is a perspective view seen from the front right upper side when the lower flange portion 44 of the coil bobbin 40 is on the upper side and the direction in which the notch portion 44a of the flange portion is located in front.

  9A is a plan view of the coil bobbin 40, FIG. 9B is a left side view of the coil bobbin 40, FIG. 9C is a front view of the coil bobbin 40, and FIG. FIG. 9E is a bottom view of the coil bobbin 40. FIG. In this case, FIG. 8B is a perspective view showing a state (use example) in which the path core unit 60 is aligned with the stepped portion 45 formed in the lower flange portion 44 of the coil bobbin 40. 10A is a cross-sectional view taken along the line 10A-10A shown in FIG. 9A, and FIG. 10B is a cross-sectional view taken along the line 10B-10B shown in FIG. 9A. 9C is a cross-sectional view taken along the line 10C-10C shown in FIG. 9A, FIG. 10D is a cross-sectional view taken along the line 10D-10D shown in FIG. 9A, and FIG. It is sectional drawing by the 10E-10E line shown to 9 (A). Note that the right side view of the coil bobbin 40 is omitted because it appears in the same manner as the left side view thereof.

  As a modification of the coil bobbin 40, a guide part 77 may be provided as shown in FIG. 12 (coil bobbin 70). That is, in the transformer 120 using the coil bobbin 70 instead of the coil bobbin 40, as shown in FIG. 11, the position in the direction (Y-axis direction) orthogonal to the insertion depth direction (X-axis base direction) of the pass core unit 60 Are provided on both sides (long side) of the opening 79 of the coil bobbin 70 in the short direction. In the portion where the guide portion 77 is provided, a thick portion 76 having a thickness similar to that of the thick portion 46 is formed.

  Thereby, in addition to positioning of the insertion depth of the pass core unit 60 by the stepped portion 45, the pass core unit is also used for the position in the direction orthogonal to the insertion depth direction (Y-axis direction, short direction of the pass core unit 60). It becomes possible to keep the insertion position of 60 appropriate.

  FIG. 11 (A) shows a cross-sectional view of the configuration of the transformer 120 when the modified coil bobbin 70 is used, corresponding to FIG. 5 (A). FIG. 11B is a cross-sectional view of the EI core 30 of the transformer 120 cut along the YZ plane from the center in the X-axis direction.

  The overall shape of the coil bobbin 70 configured as described above can be grasped from a perspective view shown in FIG. 12A, a plan view shown in FIG. 13, and a sectional view shown in FIG. FIG. 12A is a perspective view seen from the upper right of the front when the lower flange portion 44 of the coil bobbin 70 is on the upper side and the direction in which the notch portion 44a of the flange portion is in front.

  13 (A) is a plan view of the coil bobbin 70, FIG. 13 (B) is a left side view of the coil bobbin 70, FIG. 13 (C) is a front view of the coil bobbin 70, and FIG. FIG. 13E is a bottom view of the coil bobbin 70. FIG. In this case, FIG. 12B is a perspective view showing a state (use example) in which the path core unit 60 is aligned with the stepped portion 45 and the guide portion 77 formed in the lower flange portion 44 of the coil bobbin 70. is there. 14A is a cross-sectional view taken along line 14A-14A shown in FIG. 13A, and FIG. 14B is a cross-sectional view taken along line 14B-14B shown in FIG. (C) is a sectional view taken along line 14C-14C shown in FIG. 13 (A), FIG. 14 (D) is a sectional view taken along line 14D-14D shown in FIG. 13 (A), and FIG. It is sectional drawing by the 14E-14E line shown to 13 (A). The right side view of the coil bobbin 70 is omitted because it appears in the same manner as the left side view.

  As described above, in the transformers 20 and 120 of the present embodiment, the EI having the plurality of leg portions 31 to 33 extending in the same direction in a comb-like shape and the yoke portions 34 that close the tips of the plurality of leg portions 31 to 33 are provided. The primary winding which has the core 30 (iron core part 21), the coil bobbins 40 and 70 penetrated by each base end side of the some leg parts 31-33, and the primary coil 51 wound by these coil bobbins 40 and 70 A secondary winding portion 25 having a portion 23, coil bobbins 40, 70 inserted into the respective distal ends of the plurality of leg portions 31-33, and a secondary coil 52 wound around the coil bobbins 40, 70; Leakage magnetic flux flows between the adjacent leg portions 31 and 32 (or the leg portions 32 and 33) of the plurality of leg portions 31 to 33 interposed between the primary winding portion 23 and the secondary winding portion 25. Form leakage magnetic path That the path core 63, and a. A step 45 that determines the position of the insertion depth of the pass core 63 is formed on at least one of the coil bobbins 40 and 70 for the primary coil 51 or the secondary coil 52. Thereby, for example, even if the size and insertion depth of the pass core 63 may be changed due to differences in electrical specifications of the transformer 20, the position of the insertion depth of the pass core 63 can be maintained appropriately. Become. Therefore, variation in output characteristics of the transformers 20 and 120 can be suppressed.

  In the transformers 20 and 120 of the present embodiment, the path core 63 is sandwiched between a plurality of insulating plates 61 having a predetermined size, and the insertion depth of the path core 63 is between the insulating plates 61. It is positioned and fixed in the direction and the direction orthogonal thereto. As a result, the size of the surface of the pass core 63 that extends in the magnetic flux passage direction (the direction in which the leakage magnetic path is formed) and the thickness (height) of the pass core 63 may vary depending on the electrical specifications of the transformer 20. However, the size of the insulating plate 61 that sandwiches the pass core 63 in a sandwich shape is set to a predetermined dimension and does not vary. Therefore, in accordance with the size of the insulating plate 61, the step portions 45 and the guide portions 77 are formed on the coil bobbins 40 and 70 for the primary coil 51 and / or the secondary coil 52, so that the size of the pass core 63 is met. It is possible to cope with one type of coil bobbins 40 and 70 without preparing various coil bobbins. Therefore, it is possible to suppress variations in the output characteristics of the transformer 20 at a lower cost than when various coil bobbins are prepared according to the size of the path core 63.

  Furthermore, in the transformer 120 of the present embodiment, the coil bobbin 70 for the primary coil 51 and / or the secondary coil 52 has a direction (Y-axis direction) orthogonal to the insertion depth direction of the pass core 63 (X-axis root direction). ) Is formed. Thereby, in addition to the position of the insertion depth of the pass core 63, the insertion position of the pass core 63 can be properly maintained for the position in the direction (Y axis direction) orthogonal to the insertion depth direction (base direction of the X axis). It becomes possible. Therefore, since the insertion position of the path core 63 can be kept more appropriate, variations in the output characteristics of the transformer 120 can be further suppressed.

  In the above-described embodiment, the stepped portion 45 and the guide portion 77 are provided only on the lower flange portion 44 of the coil bobbins 40 and 70. However, similarly to the lower flange portion 44, the upper flange portion 43 also includes the stepped portion 45 and A guide part 77 may be provided. In this case, similarly to the lower collar part 44, the thick part 46 and the thick part 76 are formed in a part of the upper collar part 43 where the notch part 44a is not formed. In addition, the transformers 20 and 120 have been described by exemplifying the three-phase AC cores having three legs, but if the number of legs is plural, the legs may be iron cores having other configurations. Good.

  Specific examples of the present invention have been described in detail above, but these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications or changes of the specific examples described above. In addition, the technical elements described in the present specification or drawings exhibit technical usefulness alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. Furthermore, the technology illustrated in this specification or the drawings achieves a plurality of objects at the same time, and has technical utility by achieving one of the objects. Note that the description in parentheses in the [Explanation of Symbols] clearly shows the correspondence between the terms used in the above-described embodiments and the terms described in the claims.

20, 120 ... Transformer
21 ... Iron core (iron core)
23 ... Primary winding part (first winding part)
25 ... Secondary winding part (second winding part)
27 ... Leak core (leak core)
30 ... EI core (iron core)
31-33 ... Legs (multiple legs)
34 ... yoke part 35, 36 ... window part 40, 70 ... coil bobbin (first bobbin, second bobbin)
45 ... Step 51 ... Primary coil (first winding)
52 ... Secondary coil (second winding)
60 ... pass core unit 61 ... insulating plate (insulating plate)
63 ... Pass core (leakage iron core)
65 ... Core plate 77 ... Guide part

Claims (3)

An iron core having a plurality of leg portions extending in the same direction in a comb-tooth shape and a yoke portion that closes the ends of the plurality of leg portions;
A first winding portion having a first bobbin inserted into each base end side of the plurality of leg portions and a first winding wound around these first bobbins;
A second bobbin having a second bobbin inserted into the tip side of each of the plurality of legs and a second winding wound around these second bobbins;
A leakage iron core that is interposed between the first winding portion and the second winding portion to form a leakage magnetic path through which leakage magnetic flux flows between adjacent legs of the plurality of legs. ,
At least one of the first bobbin and the second bobbin is formed with a step portion that determines the position of the insertion depth of the leaking iron core.   The first bobbin and / or the second bobbin in which the step portion is formed is characterized in that a guide portion for guiding a position in a direction perpendicular to the insertion depth direction of the leaking iron core is formed. The transformer according to claim 1.   The leaking iron core is sandwiched between a plurality of insulating plates having a predetermined size, and is positioned and fixed within the insulating plate in the insertion depth direction of the leaking iron core and in a direction perpendicular thereto. The transformer according to claim 1, wherein the transformer is provided.