Coil and coil production method

Abstract

To provide a coil that can obtain a desired output and can exhibit stable performance.SOLUTION: A coil 1 having a spiral structure is realized by cutting a single block of a conductive material into a spiral shape by machine cutting, or by processing the material by die casting, for example, such that the spiral structure is continuous from one side to the other side of the coil. The coil 1 is formed of a plurality of U-shaped turn parts T stacked in an axial direction Z, and slope parts S connecting the adjacent turn parts T. In each turn part T, a first long side a, a second long side b, and a short side c are positioned on the same plane orthogonal to the axial direction Z. A cross-sectional area of the first long side a and the second long side b is the same in each of the first turn part T1 to the tenth turn part T10. In a front view, the coil 1 forms a truncated square pyramid shape having the upper surface of the first turn part T1 as an upper base surface which has the largest dimension, and the lower surface of the tenth turn part T10 as a lower base surface which has the smallest dimension.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] This invention relates to coils respectively mounted on a plurality of teeth protruding from an annular stator core such as a motor.

Background Art

[0002] Conventionally, an edgewise coil in which a flat conductor is wound in a spiral shape is known. According to such an edgewise coil, the occupancy rate with respect to the core can be improved, and the motor efficiency can be improved.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, according to Patent Document 1 and Patent Document 2, the spiral coil is composed of a plurality of coil pieces, and these coil pieces are wound axially by fastening the ends of these coil pieces to each other. Examples of the fastening method include welding and press welding. By fastening a plurality of coil pieces, problems such as distortion occurring in the fastening portion and the cross-sectional area differing from the initial setting occur. There is a possibility that the desired output cannot be obtained due to the resistance generated by the distortion generated in the fastening portion and the change in the cross-sectional area in the fastening portion, and stable coil performance cannot be exhibited.

[0005] An object of this invention is to provide a coil that can obtain a desired output and exhibit stable performance.

Means for Solving the Problems

[0006] The first invention is a coil constituting a spiral structure, comprising a plurality of stacked turn portions and a slope portion located between one of the stacked turn portions and the other turn portion. The turn portion includes opposing first and second long sides and a short side located between the first and second long sides. The thickness dimensions of the first long side, the second long side, and the short side in one turn portion are equal, and the width dimensions of the first long side and the second long side are equal. The inner walls of the first long side and the second long side are parallel to the coil axis, and the outer walls are inclined with respect to the coil axis such that when a plurality of the turn portions are stacked, the outer walls of the turn portions are located on a straight line. The slope portion is located between the second long side of one of the stacked turn portions and the first long side of the other turn portion, and is inclined such that the thickness dimension increases from the second long side end portion toward the first long side end portion. In the plurality of stacked turn portions, the cross-sectional areas of the first long side and the second long side are equal and are less than the cross-sectional areas of the short side and the slope portion. In both the turn portion and the slope portion, there is no fastening portion because they are each constituted by a single conductor material.

[0007] The second invention is a method for manufacturing a coil having a spiral structure, the coil comprising: a plurality of stacked turn portions; and a slope portion located between one of the stacked turn portions and the other turn portion, the turn portion comprising opposing first and second long sides and a short side located between the first and second long sides, the thickness dimensions of the first long side, the second long side, and the short side in one of the turn portions being equal, and the width dimensions of the first long side and the second long side being equal, the inner walls of the first long side and the second long side being parallel to the coil axis, the outer walls being inclined with respect to the coil axis such that when a plurality of the turn portions are stacked, the outer walls of the turn portions are located in a straight line, the slope portion being located between the second long side of one of the stacked turn portions and the first long side of the other turn portion and being inclined such that the thickness dimension increases from the second long side end portion toward the first long side end portion, the cross-sectional areas of the first long side and the second long side in a plurality of the stacked turn portions being equal and being less than the cross-sectional areas of the short side and the slope portion, and the coil being formed from a single piece of conductive material by die casting.

Advantages of the Invention

[0008] According to the coil of this invention, a continuous and integral spiral structure can be formed without a fastening portion, so that a change in cross-sectional area due to fastening can be suppressed, and a desired output according to the initial setting can be obtained. Thereby, stable coil performance can be exhibited.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Embodiments for Carrying Out the Invention

[0010] Referring to FIGS. 1 to 4, the coil 1 has an axial direction Z in the same direction as the coil axis, and a lateral direction X and a longitudinal direction Y that are orthogonal to each other in the axial direction Z. The coil 1 exhibits a spiral structure having a center of the spiral in the axial direction Z. The coil 1 realizes a spiral structure that is integrally continuous from one end to the other end of the coil, for example, by machining cutting that cuts a single piece of conductor material or a die casting method. That is, for example, it does not form a spiral structure by winding a flat conductor around the coil axis or fastening a plurality of cut conductors. Therefore, there are no distortions due to winding or joints due to fastening, and a desired output can be obtained.

[0011] The coil 1 having a spiral structure is composed of a plurality of U-shaped turn portions T laminated in the axial direction Z and a slope portion S connecting between two adjacent turn portions T. In this embodiment, a first turn portion T1, a second turn portion T2, a third turn portion T3, a fourth turn portion T4, a fifth turn portion T5, a sixth turn portion T6, a seventh turn portion T7, an eighth turn portion T8, a ninth turn portion T9, and a tenth turn portion T10 are provided as the turn portions T. The first turn portion T1 to the tenth turn portion T10 can be formed in a U shape by including a first long side a and a second long side b that face each other with the coil axis interposed therebetween, and a short side c located between the first long side a and the second long side b. In each turn portion T, the first long side a, the second long side b, and the short side c are located on the same plane orthogonal to the axial direction Z.

[0012] Between the second long side T1b of the first turn portion T1 and the first long side T2a of the second turn portion T2, a first slope portion S1 is provided; between the second long side T2b of the second turn portion T2 and the first long side T3a of the third turn portion T3, a second slope portion S2 is provided; between the second long side T3b of the third turn portion T3 and the first long side T4a of the fourth turn portion T4, a third slope portion S3 is provided; between the second long side T4b of the fourth turn portion T4 and the first long side T5a of the fifth turn portion T5, a fourth slope portion S4 is provided; between the second long side T5b of the fifth turn portion T5 and the first long side T6a of the sixth turn portion T6, a fifth slope portion S5 is provided; between the second long side T6b of the sixth turn portion T6 and the first long side T7a of the seventh turn portion T7, a sixth slope portion S6 is provided; between the second long side T7b of the seventh turn portion T7 and the first long side T8a of the eighth turn portion T8, a seventh slope portion S7 is provided; between the second long side T8b of the eighth turn portion T8 and the first long side T9a of the ninth turn portion T9, an eighth slope portion S8 is provided; and between the second long side T9b of the ninth turn portion T9 and the first long side T10a of the tenth turn portion T10, a ninth slope portion S9 is provided.

[0013] The first long sides T1a to T10a of the first turn portion T1 to the tenth turn portion T10 are stacked at a predetermined interval in the axial direction Z, the second long sides T1b to T10b are also stacked at a predetermined interval, and similarly, the short sides T1c to T10c are stacked at a predetermined interval. Further, the first slope portion S1 to the ninth slope portion S9 are also stacked at a predetermined interval in the axial direction Z. The first turn portion T1 to the tenth turn portion T10 and the first slope portion S1 to the ninth slope portion S9 all have a rectangular cross-section and are strip-shaped conductors.

[0014] The first turn portion T1 has the same thickness in the axial direction Z, that is, the thickness dimension from the upper surface to the lower surface, at the first long side T1a, the second long side T1b, and the short side T1c. Similarly, in the second turn portion T2 to the tenth turn portion T10, the thickness dimensions at the first long side a, the second long side b, and the short side c are equal. Also, the thickness in the axial direction Z from the first turn portion T1 to the tenth turn portion T10, that is, the thickness dimension from the upper surface to the lower surface, is made to increase. Therefore, the thickness dimension is the smallest at the first turn portion T1, gradually increases at the second turn portion T2 and the third turn portion T3, and is the largest at the tenth turn portion T10.

[0015] In this embodiment, the thickness dimension in the axial direction Z is such that the first turn portion T1 is approximately 0.58 mm, the second turn portion T2 is approximately 0.60 mm, the third turn portion T3 is approximately 0.62 mm, the fourth turn portion T4 is approximately 0.65 mm, the fifth turn portion T5 is approximately 0.67 mm, the sixth turn portion T6 is approximately 0.71 mm, the seventh turn portion T7 is approximately 0.74 mm, the eighth turn portion T8 is approximately 0.79 mm, the ninth turn portion T9 is approximately 0.84 mm, and the tenth turn portion T10 is approximately 0.90 mm. The space formed in the axial direction Z between each turn portion is approximately 0.1 mm. The space is determined in consideration of the thickness of the insulating film treatment for the coil 1.

[0016] Figure 3 is a bottom view of the coil 1. In all of the first turn portion T1 to the tenth turn portion T10, the length in the longitudinal direction Y of the first long side a and the second long side b is equal. However, the first turn portion T1, which is the first turn, is provided with one end protruding portion 11 that protrudes from the first long side T1a, and the tenth turn portion T10, which is the last turn, is provided with the other end protruding portion 12 that protrudes from the second long side T10b. In this embodiment, the lengths of the first long side a and the second long side b are approximately 23.24 mm.

[0017] The width dimensions in the lateral direction X of the first long side a and the second long side b are the largest in the first turn portion T1 provided with the one end protruding portion 11 and the smallest in the tenth turn portion T10 provided with the other end protruding portion 12. These width dimensions gradually decrease toward the tenth turn portion T10, such that the second turn portion T2 is smaller than the first turn portion T1, the third end portion T3 is smaller than the second turn portion T2, and the fourth turn portion T4 is smaller than the third turn portion T3. In this embodiment, the width dimensions of the first long side a and the second long side b are such that the width of the first turn portion T1 is approximately 12.7 mm, the second turn portion T2 is approximately 12.46 mm, the third turn portion T3 is approximately 12.22 mm, the fourth turn portion T4 is approximately 11.97 mm, the fifth turn portion T5 is approximately 11.71 mm, the sixth turn portion T6 is approximately 11.43 mm, the seventh turn portion T7 is approximately 11.15 mm, the eighth turn portion T8 is approximately 10.86 mm, the ninth turn portion T9 is approximately 10.55 mm, and the tenth turn portion T10 is approximately 10.21 mm.

[0018] The cross-sectional areas of the first long side a and the second long side b are made equal in any of the first turn portion T1 to the tenth turn portion T10. That is, ((width dimension in the lateral direction X of the upper base + width dimension in the lateral direction X of the lower base) × thickness dimension in the axial direction Z) ÷ 2 in the cross-section is made equal. Also, in each turn portion T, the cross-sectional areas of the short side c and the slope portion S are made equal to or larger than the cross-sectional areas of the first long side a and the second long side b in that turn portion T.

[0019] In particular, referring to FIG. 2, for the first slope portion S1 to the ninth slope portion S9, the thickness dimension in the axial direction Z increases from the end on the second long side b side to the end on the first long side a side of the adjacent turn portions, and they are inclined so as to descend from the end on the second long side b side to the end on the first long side a side. For example, for the first slope portion S1, the thickness dimension is 0.58 mm at the end on the second long side T1b side of the first turn portion T1, and 0.60 mm at the end on the first long side T2a side of the second turn portion T2, and it is inclined to gradually increase. Similarly, for the second slope portion S2 to the ninth slope portion S9, they are also inclined to gradually increase from the boundary portion of the second long side Tb to the boundary portion of the first long side a. By providing the first slope portion S1 to the ninth slope portion S9 in this way, the first turn portion T1 to the tenth turn portion T10 are arranged parallel to each other, and the coil 1 can form a spiral structure as a whole.

[0020] Each first long side a and second long side b of each turn portion T have an inner wall d located on the coil axis side and an outer wall e located on the opposite side. The inner wall d in each turn portion T is parallel to the axial direction Z, and the outer wall e is inclined so as to become narrower from the upper surface toward the lower surface. Also, the lateral X width dimension of the upper surface of the other turn portion located below is slightly smaller than the lateral X width dimension of the lower surface of one turn portion located above in FIG. 2. Further, since a space is formed between the lower surface of one turn portion and the upper surface of the other turn portion, the lateral X width dimensions of the upper and lower surfaces of each turn portion are determined so that the outer walls e of the other turn and one turn are located in a straight line through this space. Specifically, the lateral X dimension of the upper surface of the second turn portion T2 is slightly smaller than the lateral X dimension of the lower surface of the first turn portion T1. The lateral X dimension of the lower surface of the second turn portion T2 is slightly smaller than the lateral X dimension of the upper surface of the third turn portion T3, and the same applies to the fourth turn portion T4 and subsequent turn portions. In this way, the coil 1 forms a frustum of a square pyramid having the upper surface of the first turn portion T1 as the uppermost surface with the largest dimension and the lower surface of the tenth turn portion T10 as the lowermost surface with the smallest dimension in the front view shown in FIG. 2 (see FIG. 2).

[0021] By making the coil 1 into a frustum of a square pyramid, the coil occupancy rate when mounted on an annular stator core can be increased. That is, by installing the coil 1 on a plurality of teeth so that the tenth turn portion T10 faces the stator core, an efficient arrangement with less gaps can be achieved, and the space volume ratio can be improved. By configuring the coil 1 with a turn portion T in which a spiral structure is formed on the same plane and a slope portion S located between and inclined with respect to the turn portions T, a coil 1 in which product variations are less likely to occur can be obtained.

[0022] The output of the coil depends on the part of the conductor where the resistance is the greatest. In this embodiment, it depends on the cross-sectional areas of the first long side a and the second long side b, which are the parts with the smallest cross-sectional area. Since there are no connecting parts or fastening parts in the coil 1 in this embodiment, the cross-sectional areas of the first long side a and the second long side b in all turn parts T can be made equal, and the generation of unintended resistance due to fastening can be suppressed. Therefore, a desired output according to the initial setting can be obtained, and stable coil performance can be exhibited. Also, since the fastening process is not required, the working process can be simplified accordingly.

[0023] In this embodiment, the cross-sectional areas of the first long side a and the second long side b are made larger than the cross-sectional areas of the short side c and the slope part S. By increasing the cross-sectional areas of the short side c and the slope part S, it is possible to prevent breakage and distortion during assembly. The cross-sectional areas of the first long side a and the second long side b may be made equal to the cross-sectional areas of the short side c and the slope part S. In this case, not only the cross-sectional area from one end to the other end of the coil 1 but also all the cross-sectional areas in between can be made equal, and material reduction and space saving during assembly can be achieved. The number and size of the turns T of the coil 1 can be appropriately changed according to the size of the coil, the intended use, etc.

[0024] The coil 1 as described above is preferably manufactured by die casting. Thereby, various materials such as copper can be used, and it becomes possible to mass-produce the coil 1 without voids.

Explanation of reference numerals

[0025] 1 Coil T Turn part T1 First turn part T2 Second turn part T3 Third turn part T4 Fourth turn part T5 Fifth turn part T6 Sixth turn part T7 Seventh turn part T8 Eighth turn part T9 Ninth turn part T10 Tenth turn part S Slope part S1 First slope part S2 Second slope part S3 Third slope part S4 Fourth slope part S5 Fifth slope part S6 Sixth slope part S7 Seventh slope part S8 Eighth slope part S9 Ninth slope part a First long side b Second long side c Short side d Inner wall e Outer wall X Horizontal direction Y Vertical direction Z Axis direction

Claims

1. A coil having a spiral structure, comprising: a plurality of stacked turn portions, and a slope portion located between one of the stacked turn portions and the other turn portion; each of the turn portions includes opposing first and second long sides, and a short side located between the first and second long sides, the thickness dimensions of the first long side, the second long side, and the short side in one of the turn portions being equal, and the width dimensions of the first long side and the second long side being equal, the inner walls of the first long side and the second long side being parallel to the coil axis, and the outer walls being inclined with respect to the coil axis such that when a plurality of the turn portions are stacked, the outer walls of the turn portions are located in a straight line; the slope portion is located between the second long side of one of the stacked turn portions and the first long side of the other turn portion, and is inclined such that the thickness dimension increases from the second long side end portion toward the first long side end portion; in the plurality of stacked turn portions, the cross-sectional areas of the first long side and the second long side are equal, and are less than the cross-sectional areas of the short side and the slope portion; the coil is characterized in that both the turn portion and the slope portion are composed of a single conductor material, so that there is no fastening portion.

2. A method for manufacturing a coil having a spiral structure, wherein: the coil includes a plurality of stacked turn portions, and a slope portion located between one of the stacked turn portions and the other turn portion; each of the turn portions includes opposing first and second long sides, and a short side located between the first and second long sides, the thickness dimensions of the first long side, the second long side, and the short side in one of the turn portions being equal, and the width dimensions of the first long side and the second long side being equal, the inner walls of the first long side and the second long side being parallel to the coil axis, and the outer walls being inclined with respect to the coil axis such that when a plurality of the turn portions are stacked, the outer walls of the turn portions are located in a straight line; the slope portion is located between the second long side of one of the stacked turn portions and the first long side of the other turn portion, and is inclined such that the thickness dimension increases from the second long side end portion toward the first long side end portion; in the plurality of stacked turn portions, the cross-sectional areas of the first long side and the second long side are equal, and are less than the cross-sectional areas of the short side and the slope portion; A method for manufacturing a coil, characterized by forming the coil from a single piece of conductor material by die casting.

Images