transformer

Abstract

To provide a transformer in which a plurality of coils can be easily disposed in parallel.SOLUTION: A transformer comprises an annular frame body, a plurality of coils formed in the frame body by winding a lead wire in a circumferential direction, and an insulation wall separating the adjacent coils. The plurality of coils are composed of the one continuous lead wire, and the lead wire extending from a winding end portion of one coil formed at one face side of the insulation wall is continued over the insulation wall to a winding start portion of the other coil formed at the other face side of the insulation wall. A guide section for guiding the lead wire over the insulation wall is provided on the insulation wall, the plurality of coils are wound around the frame body while being aligned in a plurality of layers, and the lead wire extending from the guide section and the lead wire of the first layer constituting the other coil are adjacent to each other in an axial length direction of the frame body.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present disclosure relates to transformers. [Background technology]

[0002] Conventionally, a transformer is used for the purpose of voltage transformation or current transformation. A transformer may include an annular frame and multiple coils formed around the outer periphery of the frame. The multiple coils are aligned along the axial length of the frame, with an insulating wall interposed between adjacent coils over the entire periphery. This type of transformer is disclosed, for example, in Patent Document 1. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2020-188213 Summary of the Invention [Problem to be solved by the invention]

[0004] Each coil is individually formed by winding a conductor around a frame in the circumferential direction. After forming adjacent coils, the conductor extending from the end of one coil is connected to the conductor extending from the end of the other coil. Therefore, workers are forced to perform a complicated connection procedure to ensure the conductors are securely connected.

[0005] An object of the present disclosure is to provide a transformer in which multiple coils can be easily arranged in parallel. [Means for solving the problem]

[0006] A transformer according to the present disclosure includes an annular frame, a plurality of coils each formed on the outer periphery of the frame by winding a conductor in the circumferential direction and aligned in the axial direction of the frame, and an insulating wall erected on the outer periphery and separating adjacent coils over the entire circumference, wherein the plurality of coils are formed from a single continuous conductor, the conductor extending from the end of a winding of one coil formed on the outer periphery on one side of the insulating wall crosses over the insulating wall and continues to the start of a winding of another coil formed on the outer periphery on the other side of the insulating wall, the insulating wall is provided with a guide portion that guides the conductor crossing over the insulating wall, and the outer periphery on the other side of the insulating wall has a first surface extending in the circumferential direction and a second surface adjacent to the first surface in the circumferential direction and extending from the first surface the second surface has one inclined portion adjacent to the guide portion in the axial direction and inclined so that the downstream end of the conductor in the winding direction is located closer to the tip end of the insulating wall than the upstream end, and another inclined portion adjacent to the downstream side of the one inclined portion in the winding direction and inclined so that the downstream end in the winding direction is located closer to the base end of the insulating wall than the upstream end; each of the multiple coils is wound in a plurality of layers around the outer periphery, the conductor extending from the guide portion and the first layer of the conductor in contact with the other inclined portion are adjacent to each other in the axial direction; and the first surface extends in the circumferential direction from the downstream end of the other inclined portion in the winding direction to the upstream end of the one inclined portion in the winding direction and is a surface parallel to the circumferential direction.

[0007] In the present disclosure, multiple coils are made of a single continuous conductor, eliminating the need to connect the conductors together. This eliminates the need for a worker to perform a complicated connection procedure to reliably connect the conductors together, allowing multiple coils to be easily arranged side by side. The conductor that passes over the insulating wall is guided by the guide portion provided on the insulating wall, so that the conductor can pass over the insulating wall smoothly.

[0008] When a conductor is wound multiple times at the same position in the axial direction of the frame, the conductor that is farther away from the outer circumferential surface of the frame typically has a higher potential. Since each coil is wound in multiple layers, the potential of the conductor located in a higher layer among the conductors that make up the other coils is higher than the potential of the conductor located in a lower layer. Hereinafter, the axial direction of the frame will simply be referred to as the axial direction. The potential of the conductor that crosses over the insulating wall and enters the other side of the insulating wall (hereinafter referred to as the crossover wire) is equal to the potential of the conductor at the beginning of the winding of the other coil. In other words, the potential of the crossover wire is lower than the potential of the conductor that makes up the other coil. Therefore, if the crossover wire comes into contact with the high-potential conductor that makes up the other coil, there is a risk of insulation breakdown due to the large potential difference.

[0009] Therefore, the outer periphery of the frame has a first surface and a second surface. The second surface is located closer to the tip of the insulating wall than the first surface. In other words, the outer periphery of the frame has a configuration in which a portion in the circumferential direction rises toward the tip of the insulating wall. The first surface is a surface parallel to the circumferential direction. When viewed in the winding direction of the conductor (hereinafter simply referred to as the winding direction), one inclined portion of the second surface is inclined toward the tip end of the insulating wall, and the other inclined portion of the second surface is inclined toward the base end of the insulating wall. The one inclined portion is adjacent to the downstream side of the first surface and adjacent to the guide portion in the axial direction. The other inclined portion of the second surface is adjacent to the downstream side of the one inclined portion and adjacent to the upstream side of the first surface.

[0010] The crossover wire extending from the guide section and the first-layer conductor wire in contact with another inclined section are adjacent in the axial direction. Therefore, even if the crossover wire comes into contact with a conductor wire constituting another coil, the conductor wire with which the crossover wire comes into contact is a low-potential conductor wire located in the first layer. Therefore, the potential difference is small, preventing insulation breakdown due to a large potential difference. Since one inclined portion is adjacent to another inclined portion, the most elevated portion of the outer periphery of the frame does not extend far in the circumferential direction. Therefore, distortion of the other coils due to the outer periphery of the frame being uneven over the entire circumference is minimized. Therefore, there is no risk of the performance of the transformer being degraded due to distortion of the other coils.

[0011] The transformer according to the present disclosure is characterized in that the guide portion has an inclined groove having a guide slope as a bottom surface that extends downstream in the winding direction from the tip end of one surface of the insulating wall toward the base end of the other surface of the insulating wall.

[0012] In the present disclosure, the guide portion has an inclined groove. When the conductor passes over the insulating wall, the conductor is guided by the inclined groove from the tip end of one surface of the insulating wall to the base end of the other surface of the insulating wall. The guide slope of the inclined groove extends in the winding direction, which is particularly useful when, for example, the conductor is being wound by rotating the frame while the frame continues to rotate and the conductor passes over the insulating wall. The inner surface of the inclined groove prevents the conductor wire inside the inclined groove from falling out of the inclined groove toward the other coils. That is, the conductor wire inside the inclined groove is reliably insulated from the conductor wires that make up the other coils, even if the conductor wire is adjacent to the conductor wires that make up the other coils in the axial direction.

[0013] The transformer according to the present disclosure is characterized in that the boundary portion between the one inclined portion and the other inclined portion is provided at a position adjacent to the downstream end of the winding direction of the side wall of the inclined groove in the axial length direction.

[0014] In the present disclosure, the boundary between one inclined portion and another inclined portion of the second surface is located in a position adjacent to the downstream end of the side wall of the inclined groove in the winding direction in the axial direction. That is, the most elevated portion of the outer periphery of the frame is located at the same position as the exit of the inclined groove or further upstream in the winding direction than the position corresponding to the exit of the inclined groove. As a result, there is no need to extend the inclined groove downstream in the winding direction to a position where the jumper wire is adjacent to the first layer wire of another coil, so there is no risk of the inclined groove interfering with another coil.

[0015] The transformer according to the present disclosure is characterized in that the inclination angle of the guide slope is equal to the inclination angle of the other inclined portion.

[0016] In the present disclosure, the inclination angle of the guide slope, which is the bottom surface of the inclined groove, is equal to the inclination angle of the other inclined portions of the second surface. Therefore, the inclination angle of the crossover wire is equal to the inclination angle of the conductor extending downstream from the crossover wire and contacting the other inclined portions. Therefore, the boundary between the crossover wire and the conductor downstream of the crossover wire does not bend, causing the coil to bend. [Effects of the Invention]

[0017] According to the transformer of the present disclosure, multiple coils can be easily arranged in parallel. [Brief explanation of the drawings]

[0018] [Figure 1] FIG. 2 is an exploded perspective view of the transformer according to the embodiment. [Figure 2] FIG. [Figure 3] FIG. [Figure 4] FIG. [Figure 5] FIG. [Figure 6] 10A to 10C are schematic plan views for explaining a procedure for forming a coil. [Figure 7] 5 is a schematic cross-sectional view illustrating contact between a crossover wire and a conductor that constitutes a coil. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0019] In the following description, arrows indicating up and down, front and rear, and left and right are used in the drawings.

[0020] FIG. 1 is an exploded perspective view of a transformer according to an embodiment. In the figure, the transformer 1 is a transformer and includes a coil bobbin 11, two secondary coils 12 and 13, a cover 14, and two wound cores (not shown). The coil bobbin 11 includes a frame 2 and coils 31 to 34. The coils 31 to 34 are primary coils. Hereinafter, when the coils 31 to 34 are not to be distinguished from one another, they will simply be referred to as coils.

[0021] The frame 2 has a rectangular ring shape. The four corners of the frame 2 are curved in an arc shape. The frame 2 is made of an insulating material, such as synthetic resin. The left and right sides of the frame 2 are the two long sides of the frame 2, and the top and bottom sides of the frame 2 are the two short sides of the frame 2. The direction parallel to the long sides of the frame 2 corresponds to the up-down direction, and the direction parallel to the short sides of the frame 2 corresponds to the left-right direction. The axial length direction of the frame 2 corresponds to the front-rear direction. Hereinafter, the circumferential direction of the frame 2 will be simply referred to as the circumferential direction.

[0022] FIG. 2 is a perspective view of the upper side of the frame 2. FIG. 1 and 2, a groove 21 is provided on the outer periphery of the frame body 2. The groove 21 extends over the entire periphery of the frame body 2. A window portion 22 is provided in the front wall 21a of the groove 21 at each of the upper and lower sides of the frame 2. The window portion 22 has a rectangular shape, as if the front wall 21a is cut out from the top to the bottom. Similarly, a window portion 22 is provided in the rear wall 21b of the groove 21 at each of the upper and lower sides of the frame 2.

[0023] Three insulating walls 23 are arranged side by side in the front-rear direction between the front wall 21a and the rear wall 21b of the groove 21. Each insulating wall 23 extends around the entire periphery of the frame body 2, rising outward from the bottom surface of the groove 21 in the radial direction of the frame body 2. For example, at the upper side of the frame body 2, the tip end and base end of the insulating wall 23 are the upper end and lower end of the insulating wall 23.

[0024] The coils 31 to 34 are located inside the groove 21 and are lined up in this order from front to rear. Each of the coils 31 to 34 is formed by winding a conductor 3a (see FIGS. 3 and 6, which will be described later) in the circumferential direction around the bottom surface of the groove 21. The conductor 3a that constitutes each of the coils 31 to 34 is wound in an aligned manner in multiple layers (for example, five or more layers). The winding direction of the conducting wire 3a around the frame body 2 is a direction passing through the top, left, bottom, and right surfaces of the frame body 2 in that order. Hereinafter, the upstream side / downstream side of the winding direction around the frame body 2 will be simply referred to as the upstream side / downstream side. At the top edge of the frame body 2, the upstream side / downstream side is the right side / left side, and at the bottom edge of the frame body 2, the upstream side / downstream side is the left side / right side.

[0025] Coil 31 is disposed between front wall 21a and the front insulating wall 23. The front insulating wall 23 is interposed between coil 31 and coil 32. The central insulating wall 23 is interposed between coil 32 and coil 33. The last insulating wall 23 is interposed between coil 33 and coil 34. Coil 34 is disposed between the last insulating wall 23 and rear wall 21b of groove 21. Each of the coils 31 to 34 is made of a single continuous conductor 3a. That is, the coils 31 to 34 are connected in series to one another. Because each of the coils 31 to 34 is small in the front-to-rear direction, even if the ordered winding of the conductor 3a constituting one of the coils is partially disrupted, there is no risk of the voltage of the coils 31 to 34 changing significantly.

[0026] Fig. 3 is a plan view of frame 2. In Fig. 3, conductor 3a from the end of coil 31 to the start of coil 32 and conductor 3a from the end of coil 32 to the start of coil 33 are shown by two-dot chain lines.

[0027] The winding end of coil 31 contacts the front surface of front insulating wall 23. Conductor wire 3a extending from coil 31 passes over front insulating wall 23 and continues to the winding start of coil 32. The winding start of coil 32 contacts the rear surface of front insulating wall 23. Similarly, the winding end of coil 32 contacts the front surface of central insulating wall 23. Conductor 3a extending from coil 32 passes over central insulating wall 23 and continues to the winding start of coil 33. The winding start of coil 33 contacts the rear surface of central insulating wall 23. The winding end of coil 33 contacts the front surface of the last insulating wall 23. Conductor 3a extending from coil 33 passes over the last insulating wall 23 and continues to the winding start of coil 34. The winding start of coil 34 contacts the rear surface of the last insulating wall 23.

[0028] The conductor wire 3a constituting the coil 31 is generally parallel to the circumferential direction of the frame body 2. On the other hand, the conductor wire 3a constituting each of the coils 32 to 34 is partially curved toward the tip end of the insulating wall 23 at the upper side of the frame body 2, as will be described later.

[0029] As shown in Figure 1, secondary coil 12 has a rectangular ring shape and is housed radially inside coil bobbin 11. Secondary coil 13 has a rectangular ring shape. Coil bobbin 11 is housed radially inside secondary coil 13. Each of secondary coils 12 and 13 is formed, for example, by bending a rectangular wire.

[0030] The cover 14 includes two cover members 141. Each cover member 141 integrally includes two semi-cylinders adjacent to each other on the left and right, with the axial length direction of each semi-cylinder extending vertically. The two cover members 141 are combined to form the cover 14 having two cylinders. The left cylinder of the cover 14 passes inside the secondary coil 12 and covers the left side portions of the coil bobbin 11 and the secondary coils 12 and 13. Similarly, the right cylinder of the cover 14 covers the right side portions of the coil bobbin 11 and the secondary coils 12 and 13. A cylindrical wound core (not shown) is provided on the outer circumferential surface of each of the two cylinders of the cover 14.

[0031] Fig. 4 is a cross-sectional view of the frame 2. Fig. 4 shows a cross section perpendicular to the axial direction of the frame 2. The arrows in Fig. 4 indicate the winding direction of the conducting wire 3a around the frame 2. As shown in FIGS. 2 to 4, each insulating wall 23 is provided with an inclined groove 5. The inclined groove 5 extends generally in the left-right direction at the circumferential center of the insulating wall 23 at the upper side of the frame 2. The depth direction of the inclined groove 5 faces downward. One side of the inclined groove 5 in the length direction opens at the tip end of the front surface of the insulating wall 23. The other side of the inclined groove 5 in the length direction opens at the base end of the rear surface of the insulating wall 23.

[0032] The inclined groove 5 is a guide portion that guides the conductor 3a as it climbs over the insulating wall 23. The inclined groove 5 has a guide slope 51 and two inner surfaces 52 and 53. The guide slope 51 is the bottom surface of the inclined groove 5, and is an inclined surface that descends from the right end to the left end. The inner surfaces 52 and 53 rise from both widthwise ends of the guide slope 51. The inner surfaces 52 and 53 are adjacent to each other in the front-rear direction. Each of the inner surfaces 52 and 53 is an inclined surface that is positioned more forward as it moves from the right end to the left end.

[0033] A guide surface 521 extends leftward from the left end of the front inner surface 52. The guide surface 521 has the function of guiding the conductor 3a leftward from between the inner surfaces 52, 53 of the inclined groove 5 to the rear surface of the insulating wall 23. The guide surface 521 on the front insulating wall 23 guides the conductor 3a so that the winding start portion of the coil 32 contacts the rear surface of the front insulating wall 23 to the left of the inclined groove 5. Similarly, the guide surface 521 on the central (last) insulating wall 23 guides the conductor 3a so that the winding start portion of the coil 33 (coil 34) contacts the rear surface of the central (last) insulating wall 23 to the left of the inclined groove 5.

[0034] A guide surface 531 extends rightward from the right end of the rear inner surface 53. The guide surface 531 has the function of guiding the conductor 3a from the front surface of the insulating wall 23 leftward to between the inner surfaces 52, 53 of the inclined groove 5. The guide surface 531 on the front insulating wall 23 guides the conductor 3a extending from the winding end portion of the coil 31 between the inner surfaces 52, 53. Similarly, the guide surface 531 on the central (last) insulating wall 23 guides the conductor 3a extending from the winding end portion of the coil 32 (coil 33) between the inner surfaces 52, 53. The guide surfaces 521 and 531 are also guide portions that guide the conducting wire 3 a that passes over the insulating wall 23 .

[0035] 5 is an enlarged cross-sectional view of the frame 2. In FIG. 5, the vicinity of the inclined groove 5 is shown. As shown in FIGS. 4 and 5, on the rear side of the insulating wall 23, a part of the circumferential direction of the bottom surface of the groove 21 is a first surface 41, and the remaining part of the circumferential direction of the bottom surface of the groove 21 is a second surface . The first surface 41 is a surface that extends parallel to the circumferential direction. The second surface 42 extends in the circumferential direction from the downstream end of the first surface 41 to the upstream end of the first surface 41, and is located closer to the tip end of the insulating wall 23 than the first surface 41. In other words, the bottom surface of the groove 21 has a configuration in which a portion in the circumferential direction rises toward the tip end of the insulating wall 23.

[0036] More specifically, the second surface 42 has inclined portions 421 and 422. The inclined portion 421 is one inclined portion, and the inclined portion 422 is the other inclined portion. The upstream end of the inclined portion 421 is adjacent to the downstream end of the first surface 41, and the downstream end of the inclined portion 421 is adjacent to the upstream end of the inclined portion 422. The inclined portion 421 is inclined so that the upstream end is located closer to the tip end of the insulating wall 23 than the downstream end. The downstream end of the inclined portion 422 is adjacent to the upstream end of the first surface 41. The inclined portion 422 is inclined so that the upstream end is located closer to the base end of the insulating wall 23 than the downstream end.

[0037] The inclined portion 421 is adjacent to the inclined groove 5 in the front-rear direction. In this embodiment, the upstream end of the inclined portion 421 is adjacent to the upstream end of the guide slope 51 in the front-to-rear direction via the rear wall of the inclined groove 5, but it may also be adjacent to a predetermined position downstream of the upstream end of the guide slope 51 or to the guide surface 531. The boundary between the inclined portions 421 and 421 (i.e., the most elevated portion of the bottom surface of the groove 21) is adjacent in the front-to-rear direction to the downstream end of the inclined groove 5. In this embodiment, the boundary between the inclined portions 421 and 421 is adjacent to a predetermined position that is an appropriate length upstream of the downstream end of the rear wall of the inclined groove 5 (i.e., the outlet of the inclined groove 5), but it may also be adjacent to the downstream end of the rear wall of the inclined groove 5.

[0038] The downstream end of the inclined portion 422 is located at the corner between the upper side and the right side of the frame 2. The inclination angle of the guide slope 51 is equal to the inclination angle of the inclined portion 422. The guide slope 51 and the inclined portion 422 are provided integrally via an inclined surface that is flush with the guide slope 51 and extends from the guide slope 51.

[0039] 6A to 6D are schematic plan views for explaining the procedure for forming the coil. Each of Fig. 6A to Fig. 6D shows only one insulating wall 23 and the bottom surface of groove 21. For ease of viewing, insulating wall 23 is hatched in an upward sloping pattern. In the figure, reference numeral 6 denotes a coil forming device. An operator sets the frame body 2 in the coil forming device 6. The frame body 2 set in the coil forming device 6 is driven by a motor (not shown) provided in the coil forming device 6, causing it to rotate around its axis in the direction opposite to the direction indicated by the arrow in FIG. 4.

[0040] 1 to 4 are referred to as surface A, surface B, surface C, and surface D. The frame 2 set in the coil forming device 6 shown in Fig. 6 rotates so that surface A, surface B, surface C, surface D, surface A, etc. face upward in this order. 6A to 6D show a state in which surfaces A to D face upward, and Fig. 6E shows a state in which frame body 2 has made one revolution and surface A faces upward again. Coil forming device 6 is shown only schematically in Fig. 6A.

[0041] The coil forming device 6 includes a reel 61 and a traverse 62 . The reel 61 supplies the conductor 3a to be wound around the frame 2. The worker pulls out the conductor 3a from the reel 61 and guides it into the space between the front wall 21a of the frame 2, which is not yet rotating, and the foremost insulating wall 23. Next, the worker brings the conductor 3a into contact with the rear surface of the front wall 21a and pulls it out of the groove 21 through the window 22 in the front wall 21a. Furthermore, the worker temporarily fixes the starting end of the conductor 3a pulled out of the groove 21 to a jig (not shown) provided in the coil forming device 6.

[0042] After the conductive wire 3a is fixed, the frame 2 rotates, causing the conductive wire 3a to be continuously pulled out from the reel 61 and wound circumferentially in the order of side A, side B, side C, side D, side A, .... The upstream side / downstream side of side A is the side D / side B side, and the upstream side / downstream side of side C is the side B / side D side.

[0043] The traverse 62 is a roller whose axial length direction faces the front-rear direction and is provided so as to be able to move back and forth in the front-rear direction. An engagement groove is provided around the entire periphery of the traverse 62, and the conductor 3a located between the reel 61 and the frame body 2 engages with the engagement groove of the traverse 62. The traverse 62 moves back and forth in the front-rear direction with the engagement groove of the traverse 62 facing the outer periphery of the frame body 2, thereby adjusting the position where the conductor 3a is wound around the frame body 2 in the front-rear direction. The operation of the traverse 62 is controlled by a control unit (not shown) provided in the coil forming device 6.

[0044] The coils 31 to 34 are formed in this order. For ease of explanation, each of the coils 31 to 34 is formed by aligned winding of M layers, with N turns of the conductor wire 3a per layer (M and N are natural numbers). In FIGS. 6A to 6E, for example, the first turn of the first layer of the coil 32 is shown behind the insulating wall 23, but the first turn of the first layer of each of the coils 33 and 34 is similar. For ease of viewing, the start of the first turn of the first layer of the coil 32 is hatched downward to the right (see FIGS. 6A and 6E).

[0045] Here, the procedure for forming the coil 31 will be described. When forming the odd-numbered layers of the coil 31, the conductor 3a is wound once in the order of sides A to D while contacting the rear surface of the front wall 21a. When the wound conductor 3a reaches side A again, the traverse 62 moves rearward by the outer diameter of the conductor 3a. As a result, the second winding of the conductor 3a in the odd-numbered layers is adjacent to the right side of the first winding of the conductor 3a in the odd-numbered layers. On the A surface, the traverse 62 moves backward by the length of one conductor wire 3a while the conductor wire 3a is wound a predetermined N times, thereby forming an odd number of layers of the coil 31.

[0046] When forming the even-numbered layers of the coil 31, the conductor 3a is wound once in the order of sides A to D while in contact with the front surface of the foremost insulating wall 23. When the wound conductor 3a reaches side A again, the traverse 62 moves forward by the outer diameter of the conductor 3a. As a result, the second turn of the conductor 3a on the even-numbered layer is adjacent to the right side of the first turn of the conductor 3a on the even-numbered layer. On the A surface, the traverse 62 moves forward by the length of one conductor wire 3a while the conductor wire 3a is wound a predetermined N times, thereby forming an even number of layers of the coil 31.

[0047] When the Mth layer is formed, the winding of the coil 31 is completed. When winding of the coil 31 is finished, the traverse 62 moves rearward by a predetermined distance. As the traverse 62 moves rearward, a rearward external force is applied to the conductor 3a. This external force causes the conductor 3a to move from the front side of the foremost insulating wall 23 to the rear side and climb over the foremost insulating wall 23. As the conductor 3a climbs over the insulating wall 23, it is guided by the inclined groove 5.

[0048] Specifically, the conductor 3a extending from the winding end of the coil 31 is guided by the guide surface 531 and led between the inner surfaces 52 and 53 of the inclined groove 5, and is then guided by the guide slope 51 toward the base end side of the foremost insulating wall 23. Thereafter, the conductor 3a is guided by the guide surface 521 and led from between the inner surfaces 52 and 53 of the inclined groove 5 to the rear surface of the foremost insulating wall 23 (see FIG. 3). The inner surfaces 52 and 53 of the inclined groove 5 prevent the conducting wire 3 a from falling off the inclined groove 5 in the axial direction of the frame body 2 .

[0049] The coil 32 is formed by the conductor wire 3a that has climbed over the foremost insulating wall 23 in the above manner, using a procedure similar to that for forming the coil 31. When winding coil 32 to its final position, traverse 62 moves rearward by a predetermined distance, similar to when winding coil 31 to its final position. As a result, conductor 3a extending from the final portion of coil 32 is guided by inclined groove 5 and climbs over central insulating wall 23. After that, coil 33 is formed by conductor 3a that has climbed over central insulating wall 23.

[0050] After the coil 33 is formed, the conductor 3a extending from the end of the coil 33 is guided by the inclined groove 5 and led to the rear surface of the last insulating wall 23. The conductor 3a that has climbed over the last insulating wall 23 forms the coil 34. After the coil 34 is formed, the rotation of the frame 2 is stopped. The worker removes the frame 2 from the coil forming device 6.

[0051] According to the above-described manufacturing method for transformer 1, the work of connecting conductor wires 3a to each other is unnecessary. Therefore, the worker is not forced to perform a complicated connection procedure to reliably connect conductor wires 3a to each other, and multiple coils 31 to 34 can be easily arranged side by side. Moreover, because inclined grooves 5 extend in the direction in which conductor wire 3a is wound around frame 2, there is no need to stop the rotation of frame 2 while forming coils 31 to 34. Furthermore, the inclined grooves 5 provided in the insulating wall 23 guide the conducting wire 3a as it passes over the insulating wall 23, so that the conducting wire 3a can pass over the insulating wall 23 smoothly.

[0052] Here, the reason why the first surface 41 and the second surface 42 are provided on the bottom surface of the groove 21 will be described. Each of the coils 31 to 34 is wound in M ​​layers, where M is, for example, 5. Of the conductors 3a constituting each of the coils 31 to 34, the conductors 3a located in higher layers have a higher potential than the conductors 3a located in lower layers. For example, the potential of the conductors 3a at the start of the coil winding (i.e., the conductors 3a in the first layer) is lower than the potential of the conductors 3a in the second and subsequent layers.

[0053] 7 is a schematic cross-sectional view for explaining the contact between a crossover wire 3b (described later) and a conductor wire 3a constituting the coil. In FIG. 7, the rear side wall of the inclined groove 5 is indicated by a two-dot chain line. For example, the potential of the conductor 3a (hereinafter referred to as the crossover wire 3b) that passes over the insulating wall 23 from the winding end portion of the coil 31 and enters the rear side of the insulating wall 23 is equal to the potential of the conductor 3a at the winding start portion of the coil 32. In other words, the potential of the crossover wire 3b is equal to or lower than the potential of the conductor 3a that constitutes the coil 32.

[0054] Therefore, if the crossover wire 3b comes into contact with the high-potential conductor 3a that constitutes the coil 32, there is a risk of dielectric breakdown due to the large potential difference. Experiments have shown that when the crossover wire 3b comes into contact with the conductor 3a in the fifth or higher layer, the insulating layer (not shown) covering the surface of the conductor 3a can be destroyed. Contact between the crossover wire 3b with a destroyed insulating layer and the conductor 3a in the fifth or higher layer causes a short circuit, degrading the performance of the transformer 1. Such a problem may also occur in the coils 33 and 34.

[0055] As described above, the bottom surface of the groove 21 has a configuration in which a portion in the circumferential direction rises toward the tip end of the insulating wall 23 (see FIGS. 4 and 5). As shown in FIG. 7, the crossover wire 3b is guided by the inclined groove 5 and extends toward the bottom surface of the groove 21, and then extends out of the inclined groove 5 and is guided by the inclined portion 422 of the second surface . On the other hand, the conductor 3a extending downstream from the crossover wire 3b is guided by the first surface 41 and makes one turn around the frame body 2, and then is guided by the inclined portion 421 of the second surface 42 and extends toward the tip end of the insulating wall 23 (see the conductor 3a clearly shown in FIG. 7). Thereafter, the beginning of the second turn of the first layer is adjacent in the front-rear direction to the crossover wire 3b extending out from the inclined groove 5 near the exit of the inclined groove 5, and is guided by the inclined portion 422 of the second surface 42 and extends toward the base end of the insulating wall 23.

[0056] Therefore, even if the crossover wire 3b comes into contact with the conductor wire 3a that constitutes the coil 32, the conductor wire 3a that the crossover wire 3b comes into contact with is the conductor wire 3a located in the first layer and has a low potential. Therefore, the potential difference is small, so it is possible to prevent insulation breakdown due to a large potential difference. The crossover wire 3b extending from the inclined groove 5 is sufficiently far from the conductor wires 3a in the fifth layer or higher, so even if the crossover wire 3b is slightly misaligned, there is no risk of it coming into contact with the conductor wires 3a in the fifth layer or higher. The crossover wires 3b inside the inclined grooves 5 are insulated from the conductor wires 3a that make up the coil 32, and therefore there is no risk of them coming into contact with the conductor wires 3a in the fifth layer or higher.

[0057] Incidentally, when the coil 32 is formed, the conducting wire 3a travels from the surface D toward the surface A along the first surface 41, inclining toward the tip end of the insulating wall 23 along the inclined portion 421 of the second surface 42, and then travels toward the surface B while inclining toward the base end of the insulating wall 23 along the inclined portion 422 of the second surface 42. Therefore, it can be said that the coil 32 is partially distorted in the circumferential direction. However, since the inclined portions 421 and 422 are adjacent to each other, the most elevated portion of the bottom surface of the groove 21 does not extend far in the circumferential direction. In addition, since the inclined portion 421 extends far on the upper side of the frame 2, the inclination of the inclined portion 421 is gentle.

[0058] On the other hand, the inclination of inclined portion 422 is steeper than the inclination of inclined portion 421. However, the downstream end of inclined portion 422 is located at a corner of frame body 2. Even if the bottom surface of groove 21 has a surface similar to first surface 41 instead of second surface 42, the bottom surface of groove 21 at the corner of frame body 2 is inclined toward the base end side of insulating wall 23 when viewed from the bottom surface of groove 21 at the upper side of frame body 2. Therefore, the adverse effect of the inclination of inclined portion 422 on coil 32 can be ignored. As a result of the above, distortion of the coil 32 caused by the bottom surface of the groove 21 of the frame 2 not being flat all around is minimized. Therefore, there is no risk of the performance of the transformer 1 being degraded due to distortion of the coil 32.

[0059] Similarly, even if the crossover wire 3b of the coil 33 (or coil 34) comes into contact with the conductor wire 3a that constitutes the coil 33 (or coil 34), it is possible to prevent dielectric breakdown due to a large potential difference. Furthermore, there is no risk of the performance of the transformer 1 being degraded due to distortion of the coil 33 (or coil 34).

[0060] The highest point on the bottom surface of groove 21 is located upstream in the winding direction of the position corresponding to the exit of inclined groove 5. As a result, there is no need to extend inclined groove 5 downstream in the winding direction to the position where crossover wire 3b is adjacent to first layer conductor 3a of the coil, so there is no risk of inclined groove 5 interfering with the coil. This is also true when the highest point on the bottom surface of groove 21 is located at the position corresponding to the exit of inclined groove 5.

[0061] Because the inclination angle of guide slope 51 of inclined groove 5 is equal to the inclination angle of inclined portion 422 of second surface 42, the inclination angle of crossover wire 3b is equal to the inclination angle of conductor 3a extending downstream from crossover wire 3b and contacting inclined portion 422. Therefore, the boundary between crossover wire 3b and conductor wire 3a downstream of crossover wire 3b will not bend, causing distortion of the coil.

[0062] The configuration of the second surface 42 is not limited to the above configuration. For example, the inclined portions 421, 422 may be inclined more sharply or more gradually. A surface parallel to the circumferential direction may be present between the inclined portions 421 and 422. Grooves (see FIG. 3) for aligning the conductor wires 3a are provided on the first surface 41 and a part of the second surface, but the present invention is not limited to this. In addition, in order to remove weight from the frame body 2, recesses (see FIG. 4) are provided on the first surface 41 to the extent that they do not cause distortion in the coils 31 to 34, but the present invention is not limited to this. The transformer 1 may be for power or for instrumentation. The transformer 1 may also be a current transformer.

[0063] The embodiments disclosed herein are to be considered as illustrative in all respects and not restrictive. The scope of the present invention is intended to include not only the above-mentioned meaning but also the meaning equivalent to the claims and all modifications within the scope of the claims. [Explanation of symbols]

[0064] 1 transformer; 2 frame; 23 insulating wall; 31-34 coil; 3a conducting wire; 41 first surface; 42 second surface; 421 inclined portion (one inclined portion); 422 inclined portion (another inclined portion); 5 inclined groove (guide portion); 51 guide slope; 521, 531 guide surface (guide portion)

Claims

1. an annular frame; a plurality of coils each formed on the outer periphery of the frame by winding a conducting wire in a circumferential direction and arranged in an axial direction of the frame; an insulating wall erected on the outer periphery and separating adjacent coils over the entire periphery; In a transformer comprising: the plurality of coils are formed from one continuous piece of the conductor; the conducting wire extending from the winding end portion of one coil formed on the outer periphery on one surface side of the insulating wall crosses over the insulating wall and continues to the winding start portion of another coil formed on the outer periphery on the other surface side of the insulating wall, the insulating wall is provided with a guide portion that guides the conducting wire over the insulating wall, The outer periphery on the other side of the insulating wall is a first surface extending in the circumferential direction; a second surface that is adjacent to the first surface in the circumferential direction and is located closer to the tip end of the insulating wall than the first surface; and The second surface is an inclined portion adjacent to the guide portion in the axial direction and inclined so that a downstream end of the winding direction of the conductor is positioned closer to the tip end of the insulating wall than an upstream end of the winding direction of the conductor; another inclined portion that is adjacent to the downstream side of the one inclined portion in the winding direction and is inclined so that the downstream end in the winding direction is located closer to the base end of the insulating wall than the upstream end; and Each of the plurality of coils is wound in a plurality of layers around the outer periphery, the conducting wire extending from the guide portion and the conducting wire of the first layer in contact with the other inclined portion are adjacent to each other in the axial direction; A transformer characterized in that the first surface extends in the circumferential direction from the downstream end of the other inclined portion in the winding direction to the upstream end of the one inclined portion in the winding direction, and is a surface parallel to the circumferential direction.

2. 2. The transformer according to claim 1, wherein the guide portion has an inclined groove having a guide slope as a bottom surface that extends downstream in the winding direction from a tip end portion of the one surface of the insulating wall toward a base end portion of the other surface of the insulating wall.

3. The transformer according to claim 2, characterized in that the boundary portion between the one inclined portion and the other inclined portion is provided at a position adjacent to the downstream end of the winding direction of the side wall of the inclined groove in the axial length direction.

4. 4. The transformer according to claim 2, wherein the inclination angle of the guide slope is equal to the inclination angle of the other inclined portion.

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