JPH0471354A - Manufacture of cylindrical coil - Google Patents

Abstract

PURPOSE:To manufacture a cylindrical coil having high accuracy and a high space factor by preparing an internal cylindrical body having approximately the same length as an external cylindrical body and the outside diameter smaller than the inside diameter of the external cylindrical body and composed of the same blank as the external cylindrical body. CONSTITUTION:An internal cylindrical body 20 having approximately the same length as an external cylindrical body 10 and the outside diameter smaller than the inside diameter of the external cylindrical body 10 is manufactured by the same blank. A plurality of spiral slits are formed to sections except both upper and lower end sections of the external cylindrical body 10, and a plurality of sections except both upper and lower end sections of a spiral external coil element piece are formed. Likewise, a plurality of one parts of spiral internal coil element pieces separated by the slits are shaped. The internal cylindrical body 20 is housed in the external cylindrical body 10 while interposing electric insulating layers, and both upper and lower end sections of coil element pieces on the inside and the outside are superposed in the circumferential direction. The slits are extended up to both upper and lower end faces of each cylindrical body, thus completing coil element pieces on the inside and the outside. Opposed coil element pieces in the circumferential direction in the coil element pieces on the inside and the outside are welded mutually at upper end sections and lower end sections, and coupled electrically and mechanically.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method of manufacturing a cylindrical coil used in a rotary electro-mechanical energy conversion device such as a motor or a generator.

(Prior technology) A general-purpose brushless DC motor detects the rotational position of a rotor magnet inside a cylindrical coil using a magnetic sensor, etc., and sequentially passes current through multiple phase coils inside the cylindrical coil in synchronization with this rotational position. By moving, a rotating magnetic field is generated,
The rotor magnet is configured to generate continuous rotational torque. For details on the operating principle and structure of this brushless DC motor, please refer to the Japanese Patent Publication No. 57
-14110 etc.

Methods for manufacturing cylindrical coils used in such brushless DC motors include the above-mentioned patent publications and Japanese Patent Application Laid-Open No. 1988-62.
244251, and a method of processing a helical sheet as disclosed in Japanese Patent Publication No. 6o-35900, etc. are known.

Another manufacturing method for cylindrical coils is disclosed in Japanese Patent Application Laid-open No. 1986-10.
934, by twisting a cylindrical body in which linear coil pieces are arranged around its axis,
Some coil pieces cause spiral deformation.

That is, as shown in the perspective view of FIG. 10, by twisting the outer cylindrical body 5o, in which linear coil pieces 51, 52, 531 are arranged with an electrically insulating layer interposed therebetween, around its central axis (A ), coil pieces 51, 52, 53...
A spiral deformation is caused in (B). Further, as shown in FIG. 11, a linear coil piece 61. ．． 62.63・
By twisting the inner cylindrical body 60, which has a diameter smaller than the inner diameter of the cylindrical bodies arranged with an electrically insulating layer interposed therebetween, in the opposite direction around its central axis (A), the coil pieces 61° 62.6
3. causes a spiral deformation (B).

Next, as shown in FIG. 12, the inner cylindrical body 60 is inserted into the outer cylindrical body 50 with an electrically insulating layer interposed therebetween, and the upper and lower ends of the opposing coil pieces are electrically and mechanically connected by welding or the like. Connect to.

When the center lines of the inner and outer coil pieces are laid out on a plane, the result is as shown in FIG. 13. However, in this figure, only a part of the coil segment group constituting one layer of coils is shown to avoid complexity. When the coil is energized, currents flow in opposite directions to the adjacent inner and outer coil pieces, so N poles and S poles appear alternately between the two pieces.

A rotating magnetic field that rotates in the circumferential direction can be generated by sequentially passing a current through the coils of each layer formed to be shifted in the circumferential direction.

(Problems to be Solved by the Invention) Among the conventional cylindrical coil manufacturing methods described above, those that process windings and helical sheets generate unnecessary bending parts, making it difficult to improve shape accuracy and space factor. There is a problem.

In addition, even with the manufacturing method in which linear coil pieces are arranged in a cylindrical shape and twisted, it is not possible to give a uniform twist due to variations in the material of the coil pieces, resulting in improved shape accuracy and space factor. The problem is that it is difficult.

(Means for Solving the Problems) A method for manufacturing a cylindrical coil according to the present invention includes a step of creating an outer cylindrical body made of a conductor, a length approximately the same as that of the outer cylindrical body, and an inner diameter of the outer cylindrical body. A process of creating an inner cylindrical body having an outer diameter smaller than that of the outer cylindrical body and made of the same material as the outer cylindrical body, and forming a plurality of spiral slits at a predetermined pitch in the outer cylindrical body except for the upper and lower ends. forming a plurality of parts of the spiral outer coil pieces separated by the slits, and forming a plurality of parts of the outer cylindrical body at the predetermined pitch in a portion other than the upper and lower ends of the inner cylindrical body. A step of forming a plurality of spiral inner coil pieces separated by the spiral slit by forming a spiral slit in the opposite direction to the spiral slit, and interposing an electrically insulating layer inside the outer cylinder. accommodating the inner cylindrical body and overlapping both the upper and lower ends of the inner and outer coil pieces in the circumferential direction, and arranging the upper and lower ends of these overlapping slits along the axial direction of each cylindrical body. The process of completing the inner and outer coil pieces by extending them to both the upper and lower end surfaces, and the process of forming the inner and outer coil pieces before and after completion, which are opposite or circumferentially adjacent to each other, at their upper and lower ends. The method includes a step of electrically connecting the coil at the section, and is configured to enable manufacturing of a cylindrical coil with high precision and a high space factor.

Hereinafter, the operation of the present invention will be explained in detail together with examples.

(Example) First, as shown in FIG. 1(A), an external cylindrical body 10 of an appropriate length and thickness is made of a conductor such as a copper alloy or an aluminum alloy. Around this time, Figure 1 (
As shown in B), an inner cylindrical body 20 having substantially the same length as the outer cylindrical body 10 and an outer diameter smaller than its inner diameter is made of the same material.

Next, as shown in FIG. 2(A), spiral-shaped sleeves) S
A plurality of +, S2, S, l... are formed. These slits are formed by fixing the external cylindrical body 10 to a turntable, rotating the turntable at a constant speed, and irradiating a high-energy laser beam in the direction of the central axis while moving vertically at a constant speed. It is done by doing, etc. With the formation of this slit, each slit S, , S2 . Excluding both upper and lower ends of the spiral outer coil pieces 11, 12, 13... separated by S,... (multiple parts are formed. At this stage, separation of the coil pieces is To prevent this, slits are not formed at both the upper and lower ends.

Similarly, as shown in FIG. 2(R), the inner cylindrical body 2
By forming a plurality of spiral slits S+, 32, S3, etc. at the same pitch as the outer piece in the part excluding both the upper and lower ends of 0, the spiral slits separated by each slit 5Sz, S3, etc. Inner coil piece 21, 22.2
Form a plurality of parts of 3.... The maximum turning angle between the upper and lower ends of this inner coil piece is the same as that of the outer coil piece, but the turning direction is opposite to that of the outer coil piece.

Subsequently, as shown in FIG. 3, the inner cylindrical body 20 is accommodated in the outer cylindrical body 10 with an electrically insulating layer interposed therebetween, and the upper and lower ends of the inner and outer coil pieces are overlapped in the circumferential direction. As the electrical insulating layer, an epoxy resin adhesive or the like is selected so that it also serves as an adhesive.

Next, as shown in Fig. 4, the upper and lower ends of the slits on each of the stacked cylinders are extended along the axial direction of each cylinder to the upper and lower end surfaces of the inner and outer coil elements. Complete the pieces. In this case, since the coil pieces on each cylindrical body are adhered to each other, the completed coil pieces are not separated from each other.

Finally, as shown in Fig. 5, by welding the inner and outer coil pieces that face each other in the circumferential direction at their respective upper and lower ends as indicated by 31.3233... Connect electrically and mechanically.

The outer cylindrical body 10 and the inner cylindrical body 20 are bonded together with a thin adhesive layer 40 that also serves as an electrical insulating layer, as shown in the cross-sectional view of FIG.

As another structure, as shown in the cross-sectional view of FIG. Alternatively, they may be separated through a gap, and may also be in contact with each other through flanges at both upper and lower ends. In this structure that does not use adhesive, in order to prevent these coil pieces from separating at the same time as the inner and outer coil pieces are completed due to the extension of the slit explained in Fig. 5, each coil piece is Welded portions 30 are formed at the upper and lower ends of the coil piece. In this structure, since no adhesive layer is interposed between the inner and outer coil pieces, welding of both the upper and lower ends becomes easy. Instead of forming thick portions that protrude inward at both upper and lower ends of the outer cylindrical body 10, thick portions that protrude outward may be formed at both upper and lower ends of the inner cylindrical body 20.

FIG. 8 is a plan view of the structure shown in FIG. 5 viewed from directly above, and FIG. 9 is a developed view showing the inner and outer coil pieces shown in FIG. 8 developed on a plane. However, the inner coil element group shown in the upper part of FIG. 9 is shown upside down.

A three-phase U, V, and W electric path is formed by the inner and outer coil pieces. Groups of coil pieces forming electric circuits for each phase of U, V, and W are shown in the same order by solid black or hatching), addition of dots, and white outline. The reference symbols U, V, and W attached to each coil piece represent U phase and ■ phase, respectively.

This indicates that this is a group of coil pieces forming a W-phase electrical path. Further, the numbers added below U, V, and W indicate the number of the coil element forming the electric path of each phase. Furthermore, the dash added to the top of the reference symbol indicates the lower end of the coil segment to which this reference symbol is attached.

In the TJ phase electric circuit, a current flows into one end of the first coil element tJ, flows from its lower ends u and l to the lower end U2' of the second coil element, and from its upper end IJ2. 3
The current flows to the second coil element U3. Similarly, the current that has passed around the cylinder once flows through the outer coil element UIO and into the inner coil element LJ++. The current that has gone around the cylinder one more time passes through the outer coil element U2° and then reaches the inner coil element U21.
flows to In this way, the current that has passed around the cylinder five times is
The last outer coil piece LJ. flows out from the upper end of the A pair of N and S poles (two poles) is formed by a set of adjacent inner coil segment groups and an outer coil segment group,
Since there are a total of 5 sets of such coil element groups, a total of 10 poles are formed. The same applies to the circuits of the (2) phase and the W phase. Therefore, in the examples shown in Figures 8 and 9, the three-phase and one-phase
A cylindrical coil with 0 poles and 5 turns for each phase is formed.

Maximum turning angle (twist angle) of each coil piece in the circumferential direction
Assuming that θ is the number of poles and m is the number of poles, the relationship θ#360° 7m holds true as a rough guide. In the case of two poles, which is the minimum number of poles, the maximum turning angle is approximately 1800.

Here, if we take the U-phase electric circuit as an example, the outer coil element U1°, into which the current that has made one circuit around the cylinder will flow next, is offset from the inner coil element U by one pitch in the counterclockwise direction. Please note. Because of this one-pitch deviation, the outer coil element U1° faces the inner coil element Ul+ to which it should be electrically connected, making it impossible to complete this electrical connection by mechanical connection such as welding. It becomes possible. That is,
Without giving this one pitch deviation, the outer coil pieces U, o
When facing the inner coil piece U, the outer coil piece U. A complicated work is required to diagonally connect the coil element U11 and the inner coil element U11 with a wire-shaped or plate-shaped conductor interposed therebetween. In addition, in such a structure in which wire-shaped or plate-shaped conductors are interposed and connected diagonally, the mechanical bonding force between the inner and outer coil pieces is insufficient, so another strong mechanical coupling mechanism is required. is required.

Similarly, the outer coil outer side LJzo, into which the current that has made one more round on the cylinder flows next, is arranged so as to be offset from the inner coil element U11 by one pitch and to face the inner coil element U21. The same applies to the circuits of the (2) phase and the W phase. In this way, there are 15 inner coil segment groups U1 to W41 that include one input/output end of the electrical circuit for each phase, and 15 outer coil segments that include the other input/output end of the electrical circuit for each phase. Group U Io −
By arranging the wires W 5° so as to be shifted by one pitch in the circumferential direction, diagonal connections via electric wires, conductor plates, etc. are no longer necessary, and electrical connections that also serve as mechanical connections such as welding become possible.

In a preferred embodiment of the invention, each one of the input and output terminals, including the input and output ends, is
The rotation angles of the five inner coil segment groups and the outer coil segment group are arranged so that the rotation angles of the five inner coil segment groups and the outer coil segment group are smaller by an amount corresponding to one pitch than the rotation angles of other parts.

The cylindrical coil according to the manufacturing method of the present invention can be applied not only to brushless DC motors but also to electric-mechanical energy conversion devices including DC generators, induction machines, synchronous machines, etc., and electromagnets. be.

(Effects of the Invention) Since the method for manufacturing a cylindrical coil according to the present invention is configured as described above, it is possible to manufacture a cylindrical coil with high precision and a high space factor.

In addition, since the manufacturing method of the present invention does not require winding or twisting linear coil pieces, a wide range of conductors, including conductors made of brittle materials such as superconductors, can be used as coil pieces. It also has the advantage of being able to be used as

[Brief explanation of drawings]

1 to 5 are perspective views illustrating each step of a method for manufacturing a cylindrical coil according to an embodiment of the present invention, and FIGS.
The figure is a cross-sectional view illustrating a method of connecting the inner cylindrical body and the outer cylindrical body, and FIGS. 8 and 9 are plan views illustrating an example of the arrangement and electrical connection of the coil element group of the completed cylindrical coil. 10 to 12 are perspective views for explaining a conventional method of manufacturing a cylindrical coil, and FIG. 13 is a conceptual diagram for explaining an example of the operation of a general cylindrical coil. 10... Outer cylindrical body, 11, 12. 13... Spiral coil piece formed in the outer cylindrical body, 20...
Inner cylindrical body, 21, 22, 23... Spiral coil pieces formed in the inner cylindrical body, Sl, S2. S3...
・Spiral slit formed on each cylinder, 30.3
1, 32. 33... Welded part electrically and mechanically connects the upper ends of the inner and outer coil pieces, 40... Electrically insulating adhesive interposed between the inner and outer cylindrical bodies . Patent applicant Honda Motor Co., Ltd.

Claims (3)

[Claims] (1) A step of creating an outer cylindrical body made of a conductor; A step of creating an inner cylindrical body made of a raw material, and forming a plurality of spiral slits at a predetermined pitch in a portion of the outer cylindrical body excluding both upper and lower ends, thereby forming a spiral outer coil separated by the slits. forming a plurality of pieces, and forming spiral slits at the predetermined pitch in a portion of the inner cylindrical body excluding both upper and lower ends thereof and having a direction opposite to that of the spiral slits formed in the outer cylindrical body. forming a plurality of spiral inner coil pieces separated by the slit; and accommodating the inner cylindrical body with an electrically insulating layer interposed in the outer cylindrical body, and accommodating the inner and outer coil pieces. By overlapping the upper and lower ends of the coil pieces in the circumferential direction, and by extending the upper and lower ends of the circumferentially overlapped slits along the axial direction of each cylinder to the upper and lower end surfaces of each cylinder. A step of completing the inner and outer coil pieces, and electrically connecting the inner and outer coil pieces that are opposite or circumferentially adjacent to each other before or after completion at their respective upper and lower ends. A method for manufacturing a cylindrical coil, the method comprising: connecting the coil to the cylindrical coil. (2) The portions of the inner and outer coil segment groups that include the input and output ends are arranged with a one-pitch shift in the circumferential direction, and between the opposing inner and outer coil segments. 2. The method of manufacturing a cylindrical coil according to claim 1, wherein the electrical connection is made only at the cylindrical coil. (3) The method for manufacturing a cylindrical coil according to claims 1 and 2, wherein the step of forming the spiral slit is performed by irradiation with a laser beam.