Coil for static induction device, method and apparatus for manufacturing coil for static induction device

Abstract

To improve the workability of a coil winding work while achieving miniaturization as a whole.SOLUTION: A coil for a stationary induction device according to an embodiment is configured by continuously winding a conductor in a cylindrical shape so as to form a plurality of turns in an axial direction and a plurality of layers in the inner and outer peripheral directions, and a round wire portion in which the conductor has a round wire shape and a flat portion in which the conductor has a flat shape obtained by crushing the round wire are mixed, and the flat portion is arranged at least on the side portion accommodated in a window portion of an iron core.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] An embodiment of the present invention relates to a coil for a stationary induction device, and a method and apparatus for manufacturing a coil for a stationary induction device. [Background technology]

[0002] For example, a known coil used in a transformer for high-voltage power receiving and distribution equipment is one in which a rectangular wire with a flat cross section is wound in multiple layers to form a rectangular tube as a whole (see, for example, Patent Document 1). In this case, the use of rectangular wire as the conductor constituting the coil allows for a better space factor than when round wire is used. Patent Document 1 also discloses a so-called inclined continuous winding in which stepped down and up winding sections are alternately formed, thereby suppressing the voltage between the terminals. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 9-7852 Summary of the Invention [Problem to be solved by the invention]

[0004] As described above, when a flat wire is used as the coil conductor, the space factor can be increased by tightly winding the wire. However, during the coil winding process, the flat wire is easy to bend in one direction but difficult to bend in other directions. Therefore, there is a risk of damaging the surface insulation coating when trying to forcibly bend the flat wire at corners or stepped areas. In contrast, when a round wire is used as the coil conductor, the round wire can be bent in various directions, making winding easier, but as mentioned above, the space factor is inferior and it is not suitable for miniaturizing coils.

[0005] Therefore, the present invention provides a coil for a stationary induction device that can be made smaller overall while improving the workability of the coil winding work, as well as a method and apparatus for manufacturing the coil for a stationary induction device. [Means for solving the problem]

[0006] The inventors focused on the idea of ​​turning round wire, a conductor commonly used in coils for stationary induction equipment, into a flattened conductor by applying pressure and flattening it, and confirmed that by partially flattening round wire to create a flattened conductor and using it to wind a coil, it is possible to achieve both the workability of round wire and the high space factor of rectangular wire. The coil for a stationary induction device according to the embodiment is constructed by continuously winding a conductor in a cylindrical shape with multiple turns in the axial direction and multiple layers in the inner and outer circumferential directions, and the conductor is a mixture of round wire portions in which the conductor is in the shape of a round wire and flat portions in which the conductor is in a flattened shape formed by crushing the round wire, and the flat portions are arranged at least on the side portions that are accommodated within the window portion of the iron core.

[0007] A manufacturing method of a coil for a stationary induction device according to an embodiment is a method for carrying out a winding process in which a conductor supplied from a conductor supply unit is continuously wound in a cylindrical shape in a coil winding unit having a winding form so as to form multiple turns in the axial direction and multiple layers in the inner and outer circumferential directions, and includes a conductor feeding process in which the round wire conductor supplied from the conductor supply unit is flattened in necessary portions to form flat conductors, and the remaining portion remains in the round wire shape and is fed to the coil winding unit, and in the conductor feeding process, at least the conductor that constitutes the side portion to be accommodated in the window portion of the iron core is fed out as a flat conductor.

[0008] The manufacturing apparatus for coils for stationary induction devices according to the embodiment includes a conductor supply unit that supplies conductors, and a coil winding unit that continuously winds the conductors supplied from the conductor supply unit around a reel in a cylindrical shape so as to form multiple turns in the axial direction and multiple layers in the inner and outer circumferential directions. The manufacturing apparatus also includes a conductor deformation device that can convert the round wire conductors supplied from the conductor supply unit into flat conductors with a crushed shape, and a control device that controls the conductor deformation device to convert the necessary portions of the conductor into flat conductors and leave the remaining portions in the shape of round wires, and the control device controls the conductor deformation device so as to convert at least the conductors that make up the side portions that are accommodated in the window portions of the iron core into flat conductors. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a front view showing an outline of an appearance of a three-phase transformer according to an embodiment. [Figure 2] A perspective view showing the outline of one coil. [Figure 3] FIG. 1 is a diagram showing a schematic diagram of the overall configuration of a coil manufacturing apparatus; [Figure 4] Diagram showing the cross-sectional shape of the round wire part of the conductor [Figure 5] Diagram showing the cross-sectional shape of the rectangular wire part of the conductor [Figure 6] FIG. 1 is a cross-sectional view showing a state during the process of winding a conductor around a bobbin. [Figure 7] Cross-sectional view showing the state of the winding on the side surface (part E in Figure 6) [Figure 8] Cross-sectional view showing the winding at the corner (F in Figure 6) [Figure 9] FIG. 10 is a diagram showing a schematic view of a step-up portion being provided. [Figure 10] FIG. 10 is a diagram showing another embodiment, in which cross-sectional shapes of conductors are arranged side by side. DETAILED DESCRIPTION OF THE INVENTION

[0010] An embodiment in which the present invention is applied to a three-phase transformer as a stationary induction device will be described below with reference to Fig. 1 to Fig. 9. Fig. 1 shows the external configuration of three-phase transformer 1, which has an iron core 2 having three legs between upper and lower yoke parts, and three coils 3 according to this embodiment provided on each leg of iron core 2. Although detailed illustration and description are omitted, coil 3 includes a secondary coil on the inner periphery and a primary coil on the outer periphery, and the entire coil is resin-molded with epoxy resin or the like.

[0011] Here, the configuration of the coil 3 according to this embodiment will be described. The coil 3 is configured by continuously winding a conductor 4 (described in detail below) in a cylindrical shape, with multiple turns, e.g., 13 turns, in the axial direction and multiple layers, e.g., a dozen or so layers, in the inner and outer circumferential directions. As shown in FIG. 2 , the coil 3 is configured, for example, as a rectangular tube that is slightly elongated in the front-to-rear direction and has rounded corners. Therefore, the coil 3 has a front surface 5, a rear surface 6, left and right side surfaces 7 and 8, and four arc-shaped corners 9. Note that in FIG. 2 , the axial direction of the coil 3 is illustrated as the up-down direction. Hereinafter, when referring to the orientation of the coil 3, the up-down direction in FIG. 2 will be referred to as the up-down direction of the coil 3.

[0012] In this embodiment, the coil 3 is wound using a well-known so-called inclined continuous winding, in which stepped down portions and stepped up portions are alternately formed, as shown in Figures 7 and 8. In Figures 7 and 8, the order of turns when winding the conductor 4 is indicated by numbers. In this inclined continuous winding, as shown in an example in Figures 7 and 8, for example, in the first layer, the conductor 4 is wound from the top to the bottom, from the first turn to the sixth turn, and after the sixth turn, the conductor 4 moves up to the second layer, where it is wound from the seventh turn to the tenth turn, and after the tenth turn, it moves up to the third layer, where it is wound from the eleventh turn to the thirteenth turn, where it is wound from the eleventh turn to the thirteenth turn.

[0013] After the 13th turn, the 14th turn is wound below the 7th turn in the second layer, and after the 14th turn, the 15th and 16th turns are wound below the 6th turn in the first layer. After the 16th turn, the 17th turn is wound up to the second layer, and after the 17th turn, the 18th turn is wound up to the third layer, and after the 18th turn, the 19th and 20th turns are wound up to the fourth layer, and so on. Although not shown in the figures, insulating material such as insulating paper may be placed at the ends of the coil 3 and between the conductors 4, as needed.

[0014] At this time, the coil 3 is wound around a bobbin having a rectangular cylindrical outer shape with rounded corners, as will be described later. For example, at one specific corner 9 on the outer surface of the bobbin, for example, the portion corresponding to the left-front corner 9 in FIG. 6, the conductor 4 is wound so as to extend linearly in a direction perpendicular to the axial direction. In contrast, at the portion corresponding to the one corner 9, as shown in FIG. 9, the conductor 4 is wound at an inclination that is offset by one pitch in the axial direction as a whole. Therefore, a jumper section 10 is provided at this corner 9, and together with this, a step-up section 11 and a step-down section (not shown) are also provided. As shown in FIG. 9, at the jumper section 10, the conductor 4 is wound in the direction of arrow A in one layer, and then, after rising at the step-up section 11, in the next layer, the direction of the inclination changes and the conductor 4 is wound in the direction of arrow B.

[0015] Now, let us consider the conductor 4. This conductor 4 is made of a metal material such as copper, and its outer surface is coated with an insulating coating. The conductor 4 constituting the coil 3 is formed as a single, continuous, long wire. As shown in FIG. 4, the conductor 4 is a mixture of round wire 4A, which is a round wire portion that remains round, and rectangular wire 4B, which is a flattened conductor formed by compressing the cross section of the round wire in both the vertical and horizontal directions, as shown in FIG. 5. Hereinafter, when distinguishing between these shapes of conductor 4, they will be referred to as round wire 4A and rectangular wire 4B, respectively.

[0016] Specifically, the flat wire 4B as the flat portion is arranged at least on the side portions 7 and 8 of the coil 3 that are accommodated in the window portion of the iron core 2. In this embodiment, the front portion 5 and rear portion 6 of the coil 3 are also made of flat wire 4B. In contrast, in this embodiment, the four corner portions 9 of the coil 3 are made of round wire 4A. Therefore, the above-mentioned jumper portion 10, step-up portion 11, and step-down portion are made of round wire 4A. In this case, the portion of the coil 3 made of flat wire 4B can be wound almost densely without gaps, thereby increasing the space factor. Meanwhile, the portion made of round wire 4A has good workability, such as bending in multiple directions, making winding easier.

[0017] Next, a manufacturing method and apparatus according to this embodiment for manufacturing the coil 3 will be described. Figure 3 schematically shows the overall configuration of a manufacturing apparatus 21 for the coil 3 according to this embodiment. This manufacturing apparatus 21 is provided with a conductor supply unit 22 located on the right side of Figure 3 for supplying the conductor 4, and a coil winding unit 23 located on the left side of the figure, with a conveying path 24 connecting these units for feeding the conductor 4 in the direction of arrow C. A drum around which the conductor 4, in this case a round wire 4A, is wound is set in the conductor supply unit 22.

[0018] The transport path 24 is provided with a plurality of feed rollers 25 and a transport mechanism (not shown). Thus, the conductor 4 is drawn out from the conductor supply unit 22, transported, for example, at a predetermined speed in the direction of arrow C, and supplied to the coil winding unit 23. The coil winding unit 23 is provided with a reel 26 for winding the conductor 4. As shown in FIG. 6 , the reel 26 has a rectangular cylindrical shape with rounded corners, and is rotatable around a central axis O of the cylinder in the direction of arrow D with the axis O oriented horizontally. The outer circumferential surface of the reel 26 corresponds to the shape of the inner circumferential portion of the coil 3.

[0019] In the coil winding section 23, the conductor 4 supplied through the transport path 24 is wound around the outer peripheral surface of the reel 26 in a cylindrical shape, successively and in multiple turns in the axial direction and multiple layers in the inner and outer peripheral directions, thereby carrying out the winding process. As shown in Fig. 6, this winding is carried out, for example, in the order of the front surface 5 of the coil 3, the front right corner 9, the right side surface 8, the rear right corner 9, the rear surface 6, the rear left corner 9, the left side surface 7, the front left corner 9, and the front surface 5.

[0020] At this time, a jumper section 10, a step-up section 11, and a step-down section are provided in the conductor 4 at the front left corner section 9. In this embodiment, as described above, the inclined continuous winding shown in Figures 7 and 8 is performed. This results in a coil 3 having a rectangular cylindrical shape with rounded corners as a whole. After winding, the coil 3 is removed from the winding frame 26. The winding operation of the coil 3 at the coil winding section 23 may be performed automatically, or may be a so-called semi-automatic method in which a worker's manual work is performed in cooperation with a machine.

[0021] A flattening machine 29 serving as a conductor deformation device is provided midway along the conveying path 24. This flattening machine 29 is configured to apply pressure to the round wire 4A supplied from the conductor supplying section 22 in two directions, vertically and horizontally, to flatten the round wire 4A and send it out toward the coil winding section 23 as a flattened rectangular wire 4B (conductor sending step). At this time, the manufacturing apparatus 21 is provided with a control device 30 configured including a computer that controls the entire system in accordance with a preset control program, and the flattening machine 29 is controlled by the control device 30.

[0022] In this way, the control device 30 controls the flattening machine 29 so that the shape of the conductor 4 wound around the reel 26 in the coil winding section 23 is a rectangular wire 4B for the portions of the coil 3 located on the side sections 7, 8, front section 5, and rear section 6, and remains a round wire 4A for the portions of the coil 3 located on the four corner sections 9, including the crossover section 10, step-up section 11, and step-down section. At this time, a sensor 31 is provided at the outlet of the flattening machine 29 to detect the shape of the fed-out conductor 4, and the control device 30 is configured to perform feedback control based on the detection signal of the sensor 31.

[0023] Next, a method for manufacturing the coil 3 according to this embodiment will be described. The manufacturing apparatus 21 performs the following steps. Specifically, a conductor 4 is drawn from a conductor supply unit 22 and supplied to a coil winding unit 23 via a conveying path 24. A winding step is performed in which the conductor 4 is continuously wound around a reel 26 in a cylindrical shape, with multiple turns in the axial direction and multiple layers in the inner and outer circumferential directions. This winding step begins with, for example, the leading end of the conductor 4 temporarily fixed to a portion of the reel 26 of the coil winding unit 23 that corresponds to the front surface 5 of the coil 3. The conductor 4 is wound around the outer surface of the reel 26 in the following order: the front surface 5, the front right corner 9, the right side surface 8, the rear right corner 9, the rear surface 6, the rear left corner 9, the left side surface 7, the front left corner 9, and the front surface 5 of the coil 3.

[0024] At the same time as this winding process is being carried out, a conductor feeding process is carried out in which a flattening machine 29 located midway along the conveying path 24 flattens the round wire 4A supplied from the conductor supply unit 22 into a flat conductor, i.e., a rectangular wire 4B, in the required portions, and feeds the remaining portion as round wire 4A toward the coil winding unit 23. In this conductor feeding process, the flattening machine 29 is controlled by the control device 30, so that the conductor 4 is formed into rectangular wire 4B in the portions of the coil 3 that are to be arranged on the front surface 5, rear surface 6, and left and right side surface portions 7 and 8. Furthermore, the portions of the coil 3 that are to be arranged on the four corner portions 9, including the crossover portions 10, step-up portions 11, and step-down portions, remain as round wire 4A.

[0025] As a result, the resulting coil 3 contains a mixture of round wire 4A and rectangular wire 4B, and the rectangular wire 4B can be wound tightly and without gaps at least around the side portions 7, 8, front portion 5, and rear portion 6 of the coil 3, which are housed within the window portion of the core 2, thereby achieving a compact size. Meanwhile, the corner portion 9, which is made of round wire 4A, is easy to process, such as bending the conductor 4 in multiple directions, and the jumper portion 10, step-up portion 11, and step-down portion can be easily wound. In this case, the insulating coating on the surface of the conductor 4 can be prevented from being damaged when forming the step-up portion 11.

[0026] As described above, the coil 3 of this embodiment can achieve the following effects and advantages. Specifically, the conductor 4 constituting the coil 3 is a continuous mixture of round wire 4A (round wire portion) and rectangular wire 4B (flat portion formed by crushing the round wire). The rectangular wire 4B portion can be wound densely without gaps, so by arranging it at least on the left and right side portions 7 and 8 of the coil 3 that are housed within the window portions of the core 2, a high space factor can be achieved, thereby enabling the coil 3 and the entire transformer 1 to be made smaller.

[0027] On the other hand, by using the round wire 4A as it is for the corners 9, step-up portions 11, step-down portions, and jumper portions 10 of the coil 3, which require bending the conductor 4 in multiple directions, it is possible to take advantage of the ease of winding. In this case, it is possible to prevent damage to the insulating coating on the surface of the conductor 4 when forming the step-up portions 11 and step-down portions. As a result, the coil 3 of this embodiment has the excellent effect of enabling the coil 3 to be wound more easily while still achieving a smaller overall size.

[0028] In particular, in this embodiment, the flat portion of the conductor 4 is configured as a rectangular wire 4B, which is a round wire 4A that has been crushed in both the vertical and horizontal directions. This allows the flat portion to be made into a rectangular wire 4B with a shape closer to that of a rectangular wire, compared to when the crushing direction is only vertical, for example, and is therefore more effective in achieving a higher space factor. Furthermore, in this embodiment, the coil 3 is wound in an inclined continuous manner, which also has the advantage of suppressing the voltage between the terminals.

[0029] The manufacturing method and manufacturing apparatus 21 for the coil 3 according to this embodiment can achieve the following actions and effects. That is, a winding process is performed in which the conductor 4 supplied from the conductor supply unit 22 is continuously wound into a cylindrical shape in a manner that forms multiple turns in the axial direction and multiple layers in the inner and outer circumferential directions in a coil winding unit 23 having a winding frame 26. During this process, a conductor feeding process is performed in which the round wire 4A is passed through a flattening machine 29 to flatten necessary portions of the round wire 4A into rectangular wire 4B, and the remaining portion is fed to the coil winding unit 23 as round wire 4A.

[0030] In this conductor feeding process, depending on whether or not the round wire 4A is deformed by the flattening machine 29, both the round wire 4A and the rectangular wire 4B can be freely supplied in a continuous form, thereby easily and inexpensively changing the shape of the two types of conductor 4. Therefore, the rectangular wire 4B can be automatically supplied to the portions that form the left and right side portions 7, 8 of the coil 3, etc., and the portion of the coil 3 housed in the window portion of the iron core 2 can have a higher space factor, allowing for the miniaturization of the coil 3 and, ultimately, the entire transformer 1.

[0031] On the other hand, since the round wire 4A is supplied to the corners 9, step-up portions 11, step-down portions, and jumper portions 10 of the coil 3, which require bending the conductor 4 in multiple directions, workability can be improved. In this case, it is possible to prevent the insulating coating on the surface of the conductor 4 from being damaged when forming the step-up portions 11 and step-down portions. As a result, the manufacturing method and manufacturing apparatus 21 for the coil 3 of this embodiment can achieve excellent effects, such as improving the workability of the winding work for the coil 3 while achieving overall miniaturization.

[0032] FIG. 10 shows another embodiment. This embodiment differs from the previous embodiment in the shape of the conductor 41 that constitutes the coil 3. The conductor 41 is configured as a single, continuous, long wire. However, the conductor 41 is a mixture of round wire 41A, which is a round wire portion that remains round, and flat conductors 41B, which are formed by compressing the round wire 41A longitudinally to form flat shapes. The flat conductors 41B have an elliptical or oblong cross-sectional shape. In this case, too, by using flat conductors 41B for necessary portions, such as the left and right side portions of the coil, the gaps are smaller than in the case of round wire 41A, allowing for more dense winding, thereby increasing the space factor and enabling the coil to be made more compact.

[0033] In the above embodiment, the coil is a rectangular tube with rounded corners, but it may be a cylindrical or octagonal tube. In this case, too, by using a flat conductor for the portion disposed within the window of the core and a round wire for the remaining portion, it is possible to improve the space factor and achieve a compact design while improving the workability of the winding process. In addition, while the above embodiment employs inclined continuous winding, it is also possible to wind the coil layer by layer starting from the inner layer. Various modifications are possible for the winding method when using inclined continuous winding.

[0034] In addition, various modifications are possible to the overall configuration of the coil manufacturing apparatus, and it goes without saying that the invention can be applied not only to three-phase transformers but also to coils for other stationary induction devices. The above-described embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be embodied in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, as well as within the scope of the invention and its equivalents as set forth in the claims. [Explanation of symbols]

[0035] In the drawings, 1 is a transformer (static induction device), 2 is an iron core, 3 is a coil, 4 and 41 are conductors, 4A and 41A are round wires, 4B is rectangular wires (flat conductors), 41B is a flat conductor, 5 is a front portion, 6 is a rear portion, 7 is a left side portion, 8 is a right side portion, 9 is a corner portion, 10 is a transition portion, 11 is a stepped portion, 21 is a manufacturing device, 22 is a conductor supply portion, 23 is a coil winding portion, 26 is a reel, 29 is a flat machine (conductor deformation device), and 30 is a control device.

Claims

1. A coil for a stationary induction device, which is configured by continuously winding a conductor in a cylindrical shape so as to form a plurality of turns in the axial direction and a plurality of layers in the inner and outer circumferential directions, and has an overall rectangular cylindrical shape, the corners of which are corner portions, The conductor has a round wire portion in which the conductor has a round wire shape and a flat portion in which the conductor has a flattened shape obtained by crushing the round wire, The flat portion is disposed at least on a side surface portion that is accommodated in a window portion of the iron core, and the round wire portion is disposed on the corner portion.

2. 2. A coil for a stationary induction device according to claim 1, wherein the round wire portion of the conductor is arranged at least in a portion having a step-up portion from one layer to the next layer.

3. 3. A coil for a stationary induction device according to claim 1, wherein the flat portion of the conductor is formed in a rectangular wire shape obtained by flattening the round wire portion in both vertical and horizontal directions.

4. A method for manufacturing a coil for a stationary induction device, comprising: a winding step of continuously winding a conductor supplied from a conductor supply unit into a rectangular tube shape in a coil winding unit having a winding frame, the winding step being multiple turns in an axial direction and multiple layers in an inner and outer circumferential direction; a conductor feeding step of flattening a necessary portion of the round wire conductor supplied from the conductor supply unit into a flat conductor, and feeding the remaining portion of the round wire conductor to the coil winding unit, In the conductor feeding process, the conductor constituting at least the side portion housed within the window portion of the iron core is made into a flat conductor, and the conductor constituting the corner portion that becomes the corner of the square tube is fed out so as to remain in the shape of a round wire.

5. 5. A method for manufacturing a coil for a stationary induction device according to claim 4, wherein in said conductor feeding step, at least a portion of the conductor having a stepped portion from one layer toward the next layer is fed out in the form of a round wire.

6. 6. A method for manufacturing a coil for a stationary induction device according to claim 4 or 5, wherein in the conductor feeding step, when feeding out the flat conductor, the received round wire conductor is crushed in two directions, vertically and horizontally, to deform it into a rectangular wire before feeding out.

7. a conductor supply unit that supplies a conductor; a coil winding unit that continuously winds the conductor supplied from the conductor supply unit around a bobbin in a rectangular tube shape by a plurality of turns in the axial direction and by a plurality of layers in the inner and outer circumferential directions, a conductor deformation device capable of deforming the round wire-shaped conductor supplied from the conductor supply unit into a flat conductor having a crushed shape; a control device for controlling the conductor deformation device to make the necessary portion of the conductor into a flat conductor and leaving the remaining portion in a round wire shape; The control device is a manufacturing device for a coil for a stationary induction device, in which the control device flattens the conductor that constitutes at least the side portion that is housed within the window portion of the iron core, and controls the conductor deformation device so that the conductor that constitutes the corner portion that becomes the corner of the square tube remains in a round wire shape.

8. 8. The manufacturing apparatus for a coil for a stationary induction device according to claim 7, wherein the control device controls the conductor deformation device so that at least a portion of the conductor having a stepped portion extending from one layer to the next layer remains in a round wire shape.

9. 9. The manufacturing apparatus for coils for stationary induction devices according to claim 7 or 8, wherein the conductor deformation device is configured to be able to deform the received round wire conductor into a flat wire by crushing it in both vertical and horizontal directions and then feed it out.

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