JP2002238226A - Miniature motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a miniature motor in which a bottomed tubular member being fitted in the hollow body section of a bobbin and passing magnetic flux can be manufactured easily and eddy current loss can be reduced in the bottomed tubular member. SOLUTION: The bobbin 4 of a miniature motor 1 has a tubular hollow body section 38 for winding an armature winding 5. A bottomed tubular member 10 having a function for passing magnetic flux 2 and a function for positioning the bobbin 4 is formed integrally of a magnetic material and fitted in the tubular hollow body section 38 of the bobbin 4 along the inner circumferential surface thereof while being connected magnetically with flux passage members 15 and 15a. The bottomed tubular member 10 is formed by making a plurality of planar bend pieces 50 integrally.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a small motor requiring low loss, low power consumption and long life.

[0002]

2. Description of the Related Art Small motors are widely used in various fields in addition to the above-mentioned various devices, and there is a demand for easy manufacturing of small motors and improvement of motor performance. In a small motor, an armature winding (hereinafter, referred to as a winding) is wound in a coil shape around a bobbin (a winding frame) to form an annular armature coil, and the bobbin having the armature coil is attached to the motor. There are cases. A general bobbin has a cylindrical hollow body around which a winding is wound and two flanges, an armature coil is housed between the two flanges, and a magnetic flux is applied to the hollow body. A core (iron core) for passing through is arranged.
In a conventional small motor, there has been proposed a core arranged at the center of the bobbin, which has a laminated structure to reduce eddy current loss.

[0003]

This conventional core has a laminated structure, and therefore has a rectangular cross section.
The hollow body of the bobbin also has a square cross section. Therefore, when winding the winding around the bobbin, a gap is formed between the hollow trunk portion and the winding, so that stack winding cannot be performed. As a result, it has been difficult to form a high-density armature coil in a small space. In order to avoid this problem, it is necessary to make the hollow body of the bobbin and the core circular in cross section. However, when manufacturing the core, it is necessary to perform post-processing so that the cross section becomes circular after lamination of the cores, so that the manufacturing process of the core has been complicated. Instead of performing post-processing, it is also possible to form a plate with a large number of dies so that the core has a circular cross section, and to laminate the plate. However, in this case, it is necessary to sequentially change the width dimension of the plate material by using various types of molds to form a core having a laminated structure having a circular cross section, and further require polishing after lamination. Therefore, manufacturing of the core becomes extremely difficult.

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and it is possible to easily manufacture a bottomed cylindrical member for fitting a hollow body of a bobbin and passing a magnetic flux,
It is another object of the present invention to provide a small motor capable of reducing eddy current loss in a bottomed cylindrical member.

[0005]

In order to achieve the above-mentioned object, a small motor according to the present invention comprises a field for generating a magnetic flux, and a plurality of bobbins each having an armature winding wound in a coil shape in a ring shape. And a gap is formed between a rotor facing portion of a plurality of magnetic flux path members formed of a magnetic material and constituting the armature, and a surface of the field. A small motor in which one of the field and the armature relatively rotates around a rotation center axis, wherein the bobbin is a cylindrical hollow for winding the armature winding. A bottomed cylindrical member integrally formed of a magnetic material and having at least a function of passing the magnetic flux and a function of positioning the bobbin, along the inner peripheral surface of the hollow body of the bobbin; For the magnetic flux path Are magnetically connected to the timber, the bottomed cylindrical member is formed by bending an integral multiple of bent pieces in the plate.

Preferably, the field rotates, the armature is mounted on a base provided on a stator side and formed of a magnetic material, and the bottomed cylindrical member is substantially aligned with the rotation center axis. It has a central axis in a parallel direction, and connects the base and the member for magnetic flux paths. As a preferred embodiment, the bottomed tubular member is formed integrally with a substantially circular or substantially polygonal bottom and an outer peripheral edge of the bottom,
A cylindrical portion formed by the plurality of bent pieces; and a flange portion integrally formed from one end of the cylindrical portion toward the outside in the radial direction, and formed by the plurality of bent pieces. Wherein the bottom portion is fixed to the base, the flange portion is magnetically engaged with the magnetic flux path member, and the bobbin is sandwiched between the base and the magnetic flux path member. It is arranged. It is preferable that the cross-sectional shape of the cylindrical portion of the bottomed cylindrical member is substantially circular or substantially polygonal. It is preferable that a gap is formed between the adjacent bent pieces. In addition, by disposing the plurality of bent pieces substantially evenly around the center axis of the bottomed tubular member, the plurality of gaps are substantially centered on the center axis of the bottomed tubular member. Preferably, the gaps are formed radially outward at the same angle and radially outward, and the gaps have substantially parallel gaps. As one embodiment, the small-sized motor has a configuration in which windings of the armature are respectively wound around a plurality of armature axes substantially parallel to the rotation center axis.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention can be applied to any small motor having a bobbin (winding frame) and a bottomed tubular member (corresponding to a core) arranged at the center of the bobbin. In this embodiment, a small motor in which a field rotates and an armature having a bobbin and a bottomed tubular member is provided on a stator side will be described as an example. In the following embodiment, an example of a small motor of a radial gap type (radial gap type) is shown.
The present invention can be applied to a small motor of an axial gap type (axial gap type). In a radial gap type small motor, a circumferential gap (air gap) is formed between the cylindrical surface of the field generating the magnetic flux and the armature, and the field or the armature moves around the rotation center axis. It is designed to rotate relative to. In the axial gap type small motor, an axial gap is formed between the disk-shaped surface of the field generating the magnetic flux and the armature, and the field or the armature rotates relatively around the rotation center axis. It is supposed to.

An embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is a front view of a small motor according to the present embodiment, and FIG. 2 is a II-II of FIG.
It is a line sectional perspective view. Note that the front side and the back side of the sheet of FIG. 1 will be described as the upward direction and the downward direction of the small motor, respectively. As shown in FIGS. 1 and 2, a small motor (hereinafter, referred to as a motor) 1 includes a field 3 that generates a magnetic flux 2 and an armature 7. In the armature 7, an armature winding (hereinafter, referred to as a winding) 5 is wound in a coil shape around a plurality (here, three) of the bobbins 4, thereby forming an annular (here, annular) armature. A coil 6 is configured. The field 3 rotates around the rotation center axis line CL.
The motor 1 has a configuration in which the windings 5 of the armature 7 are wound around a plurality (for example, three) of armature axes E parallel to the rotation center axis CL. In the present embodiment, the case where the field 3 rotates and the armature 7 is the brushless type motor 1 mounted on the base 12 on the stator side is shown.

Next, the configuration of the motor 1 will be described in detail. The motor 1 includes a base 12 as a first magnetic member. The field 3 constitutes a rotor 14 that is supported by the base 12 of the motor 1 and rotates. The armature 7 is provided on the base 12 at a position radially outward of the field 3. A gap B is formed between the field 3 and the armature 7. The gap B is formed between the cylindrical surface 8 as the surface of the field 3 and a plurality (three in this case) of rotor facing portions (corresponding to armature pole teeth) 16 and 30. A plurality (three in this case) of magnetic flux path members 15, 15 a, and 15 b as second magnetic members respectively constitute the armature 7. The rotor facing portion 16 is provided on the magnetic flux path member 15, and the other rotor facing portions 30, 30 are provided on the other magnetic flux path members 15a, 15b, respectively. The base 12 has a first plate-shaped portion 12a arranged in a plane direction orthogonal to the rotation center axis CL. Base 1
Numeral 2 is formed of a soft magnetic material (a material having a high magnetic permeability, for example, an iron plate) into a predetermined shape, and is disposed all around the rotation center axis CL in the circumferential direction.

The rotation center axis CL is arranged at a predetermined position eccentric from the center of the base 12. The three armature axes E are provided in parallel with the rotation center axis CL, and are disposed around the center with the rotation center axis CL offset. The three armature axes E are arranged at arbitrary positions around the rotation center axis CL. In the present embodiment, the three armature axes E are arranged at different angles from each other. Rotation center axis CL and armature axis E
Are substantially the same for the two armature axes E, but one armature axis E is different. A bearing support 17 is integrally formed on the base 12 so as to protrude upward and concentrically with the rotation center axis CL. A sliding bearing 18 is press-fitted and fixed inside the bearing support portion 17. The slide bearing 18 and the cover 1 attached to the base 12
The thrust bearing 20 arranged inside of 9 forms a bearing portion 21. The rotating shaft 13 is rotatably supported by the bearing 21 and extends in the direction of the rotation center axis CL.

The field 3 comprises a yoke 25 attached to the rotating shaft 13 and a plurality (two in this case) of magnets 2.
6, 26a. The motor 1 is a bipolar machine having two magnets 26 and 26a. The hollow cylindrical magnets 26 and 26 a are fixed to the yoke 25 and have a cylindrical surface 8. The magnets 26 and 26a are fixed to the outer surface of the cylindrical portion 27 of the yoke 25 about the rotation center axis CL. The outer peripheral surface of one magnet 26 is magnetized to the N pole. The other magnet 26a has its outer peripheral surface magnetized to the S pole. The rotating shaft 13 is press-fitted and fixed to the center of the yoke 25. Rotating shaft 13, yoke 25 and magnet 2
The rotor 14 is composed of the rotors 6 and 26a. The armature 7 is attached to an upper part of the plate-shaped portion 12a of the base 12,
Includes three armature units. The armature 7 separates the gap B concentric with the rotation center axis CL into magnets 26 and 26a.
Keep against. The armature 7 includes a plurality of magnetic flux path members 15, 15a, 15b and a bobbin 4
, An armature coil 6, and a bottomed tubular member (hereinafter, referred to as a core) 10.

The magnetic flux path members 15, 15a, 15b
It is formed of a soft magnetic material (for example, an iron plate). The magnetic flux path members 15, 15a, and 15b are arranged and separated from each other for each armature axis E, and at the position of the armature axis E, the base 1 via the core 10.
2 is attached in a magnetically connected state. One magnetic flux path member 15 is disposed at a predetermined position (the right position in FIG. 1) apart from the rotation center axis CL. The other pair of magnetic flux path members 15a and 15b are arranged on one side and the other side (upper and lower in FIG. 1) with the magnetic flux path member 15 interposed therebetween with the rotation center axis CL as the center. The magnetic flux path member 15 includes the rotor facing portion 16 and the second plate-like portion 28.
have. The other magnetic flux path members 15a and 15b
It has a rotor facing part 30 and a second plate-like part 29. Rotor facing portion 1 of magnetic flux path members 15, 15a, 15b
Reference numerals 6 and 30 denote members opposing the rotor 14 and opposing the magnets 26 and 26a via the gap B. That is, the partially cylindrical inner peripheral surfaces of the rotor facing portions 16 and 30 are
The gap B is maintained and opposed to the cylindrical outer peripheral surfaces of the magnets 26 and 26a.

The second plate-shaped portion 28 of one magnetic flux path member 15 is arranged substantially parallel to the base 12 apart from the base 12. The rotor facing portion 16 is provided substantially at right angles to the second plate-shaped portion 28. The second plate portion 28 and the rotor facing portion 16 are formed integrally by bending a plate material. Also in the two members 15a and 15b for magnetic flux paths,
The second plate-shaped portion 29 is arranged substantially parallel to the base 12 apart from the base 12. The rotor facing portion 30 is provided substantially perpendicular to the second plate-shaped portion 29. The second plate-shaped portion 29 and the rotor facing portion 30 are formed integrally by bending a plate material.

The armature 7 has a plurality of (here, three) cores 10 having a substantially U-shaped cross section integrally formed of a soft magnetic material (a material having a high magnetic permeability, for example, an iron plate). . The core 10 is disposed at the position of the armature axis E, and faces in a direction substantially parallel to the rotation center axis CL.
And the second plate portions 28, 29 of the magnetic flux path members 15, 15a, 15b. The core 10 is magnetically connected to the base 12 and the magnetic flux path members 15, 15a, 15b. The core 10 extends in the direction of the armature axis E, is fitted to the hollow body 38 of the bobbin 4, and is disposed at the center of the bobbin 4. The magnetic flux 2 passes between the base 12 and the second plate portions 28 and 29 via the core 10. At the position of the armature axis E, the base 12 is formed with protrusions 36 protruding upward, respectively.
A large-diameter through hole 37 is also formed in each of the holes 8 and 29. The base 1 is inserted into a small-diameter engagement hole 34 formed at the lower end of the core 10.
The core 10 is fixed to the base 12 by the engagement of the two protrusions 36. The upper part of the core 10 is inserted into the large-diameter through hole 37 of the second plate-shaped portions 28 and 29, and the flange portion has the second plate-shaped portions 28 and 29.
Are magnetically engaged.

The bobbin 4 has a cylindrical (in the present embodiment, cylindrical) hollow body 38 for winding the winding 5 around the outer periphery.
, A lower flange 39 and an upper flange 40. The lower flange 39 and the upper flange 40 are respectively formed at the lower end and the upper end of the hollow body 38 and are substantially parallel to each other. Lower collar 39
Is constituted by a plurality of (here, three) first fan-shaped plate portions, and the upper flange 40 is also constituted by a plurality of (here, three) second fan-shaped plate portions. The upper surface of the bobbin 4 (that is, the upper flange 40) contacts the second plate-shaped portions 28 and 29,
The lower surface of the bobbin 4 (that is, the lower flange 39) is in contact with the first plate portion 12a of the base 12. Bobbin 4 is core 1
0, the base 12 and the members 15 and 15 for magnetic flux paths
a and 15b, and are arranged substantially concentrically with the armature axis E. The bobbin 4 is integrally formed of an insulating material such as polyacetal.

The substantially annular holder 41 is fixed to the base 12, and a plurality (here, three) of the rotor facing portions 16,
30 (or may be in the vicinity thereof). Thus, the rotor facing portions 16 and 30 are fixed to the base 12 via the holder 41. Since the printed wiring board 42 is attached to the base 12 while being sandwiched between the holder 41 and the base 12, the printed wiring board 4
2 facilitates positioning and holding. The winding 5 and the Hall element are connected to the printed wiring board 42. The base 12 supports a rotating shaft 13, an armature 7 (here, rotor facing parts 16 and 30, a holder 41, a core 10, a bobbin 4, etc.), a printed wiring board 42, and the like.
, A second function as a mounting portion for mounting the motor 1 to a built-in mechanism, a third function constituting a part of a passage of the magnetic flux 2, and the like.

The motor 1 is provided with a magnetic pole sensor such as a Hall element. In the present embodiment, a plurality of (three in the present embodiment) Hall elements 44 are used to detect the positions of the magnets 26 and 26a constituting the rotor 14.
1 is attached. Based on the signal output from the Hall element 44, the current is controlled so as to generate a rotating magnetic field in the armature coil 6. Then, the magnets 26 and 26a of the rotor 14 existing in the rotating magnetic field are attracted and repelled by the magnetic force, and a rotating force is applied to the rotor 14 so that the rotor 14 is rotated.
Makes a rotating motion.

Next, the passage 43 of the magnetic flux 2 in the motor 1 will be described. This passage 43 is bent three-dimensionally a plurality of times at 90 degrees. For example, when the N-pole magnet 26 faces the rotor facing portion 16, the magnetic flux 2 generated by the magnet 26 enters the rotor facing portion 16 through the gap B. Next, the magnetic flux 2 is rotated by the rotation center axis CL.
After passing through the inside of the rotor facing portion 16 substantially parallel to
It bends substantially 90 degrees and passes through the second plate-shaped portion 28. That is, the magnetic flux 2 is applied to the second plate-like portion 2 as shown by the arrow F1.
8 passes in a direction substantially orthogonal to the rotation center axis CL.

Next, the magnetic flux 2 concentrates on the core 10 and the arrow F
As shown in FIG. 2, the core 10 is substantially parallel to the armature axis E.
Pass down inside. The magnetic flux 2 bends at 90 degrees below the core 10 and branches in two directions. As shown by an arrow F3, a part of the branched magnetic fluxes 2
After passing through 0, it turns 90 degrees and rises through the inside of the core 10. Then, the magnetic flux 2 bends by 90 degrees, passes through the second plate-shaped portion 29, and returns to the other magnet 26a, as shown by the arrow F4. The remaining magnetic flux 2 branched at the lower part of the core 10 passes through the base 12 and passes through the lower part of the adjacent core 10 as shown by the arrow F5. And this magnetic flux 2
Turns 90 degrees and rises through the core 10,
As shown by the arrow F6, it passes through the inside of the second plate-shaped portion 29,
It will return to the other magnet 26a.

Next, the core 10 will be described. FIG.
4 is a perspective view showing the outer shape of the core 10 of the present invention, FIG. 4 is a view showing the core 10, FIG. 4 (A) is a longitudinal sectional view, and FIG. 4 (B) is a line IV-IV in FIG. 4 (A). It is sectional drawing. FIG. 5 shows a core (bottomed cylindrical member) 10a according to a first modification of the present embodiment.
5A is a longitudinal sectional view, and FIG. 5B is a view showing FIG.
It is a VV line sectional view of (A). 6A and 6B are views showing a core (bottomed cylindrical member) 10b according to a second modification of the present embodiment, where FIG. 6A is a longitudinal sectional view, and FIG.
It is a VI-VI line sectional view of (A). FIG. 7 is a diagram showing a core (bottomed tubular member) 60 according to a comparative example of the present invention.
7A is a longitudinal sectional view, and FIG. 7B is a VII in FIG. 7A.
FIG. 7 is a sectional view taken along line VII. FIG. 8 is a graph showing experimental data of the present embodiment.

As shown in FIG. 2 to FIG.
Are fitted to the hollow body 38 along the inner peripheral surface 38a of the hollow body 38 of the bobbin 4. The core 10 is formed in a cylindrical shape with a bottom by bending a plurality of (six in the present embodiment) bent pieces 50 in a plate shape, and has a direction substantially parallel to the rotation center axis CL. Has a central axis CL1. The core 10 has a substantially circular or substantially polygonal bottom 51.
And a cylindrical portion 52 and a flange portion 53. A small-diameter engagement hole 34 centering on the center axis CL1 is formed through the bottom 51. The tubular portion 52 is integrally bent from the outer peripheral edge of the bottom portion 51, and includes a plurality of bent pieces 50. The cross-sectional shape of the tubular portion 52 is substantially circular or substantially polygonal (in the present embodiment, a dodecagon including the chamfered portion). The flange portion 53 is integrally bent outward in the radial direction from an upper end portion 54 which is one end portion of the tubular portion 52, and includes a plurality of bent pieces 50. The bottom portion 51 is fixed to the base 12, and the flange portion 53 is provided with the magnetic flux path members 15, 15a. 15b is magnetically engaged. The bobbin 4 is interposed between the base 12 and the magnetic flux path members 15, 15a, 15b.

A plurality of (six in this embodiment) bent pieces 50 integrated with the bottom part 51 form a tubular part 52 and a flange part 53 integrally. A gap G is formed between adjacent bent pieces 50. Therefore,
The core 10 has a flower-like shape in which petals are separated from each other. The plurality of bent pieces 50 are arranged substantially evenly around the central axis CL1 of the core 10.
The plurality of gaps G are formed radially outward at substantially the same angle around the center axis CL1 of the core 10. The gap dimension d of one gap G and the other gap G
Are approximately the same. Opposite surfaces 55 (or 5) are provided on both sides of the bent piece 50 forming the cylindrical portion 52.
6) and a chamfered portion 58 are formed. Chamfer 58
Is formed so that the cylindrical portion 52 extends along the inner peripheral surface 38 a of the bobbin 4. The gap G is formed by one opposing surface 55 and the other opposing surface 56 of the adjacent bent pieces 50. Both opposing surfaces 55 and 56 are formed continuously from the cylindrical portion 52 to the flange portion 53 and are parallel to each other. Therefore, since each gap G has a substantially parallel gap in the cylindrical portion 52 and the flange 53,
There is little possibility that the adjacent bent pieces 50 come into contact with each other. When the core 10 is bent, a facing surface 55 (or 56) and a chamfered portion 58 are formed in advance in a portion corresponding to the cylindrical portion 52 of each bent piece 50 punched in a petal radial shape. It is preferable to keep it. The facing surface and the chamfered portion 58 may be formed after bending.

When the core 10 is incorporated, first, the bobbin 4 containing the armature coil 6 is arranged on the upper surface of the base 12 so as to be substantially concentric with the armature axis E. Next, the core 10 is inserted downward from the large-diameter through holes 37 of the second plate-like portions 28 and 29 and fitted into the hollow body 38 of the bobbin 4. Then, the projecting portion 36 of the base 12 is
0 engaging hole 34. When the protruding portion 36 is deformed and swaged against the bottom portion 51, the core 10
Fixed to 2. Thus, the core 10 is positioned and fixed at a predetermined position such that the central axis CL1 coincides with the armature axis E. The protrusion 36 and the engagement hole 34
Without providing the core, the core may be fixed to the base by welding or the like. As a result, the lower surface 57 of the flange portion 53 is magnetically engaged with the second plate-shaped portions 28 and 29 and is brought into close contact therewith. As a result, the bobbin 4 is positioned and held in a state of being sandwiched between the base 12 and the second plate-like portions 28 and 29, and the hollow body 38
The cylindrical portion 52 of the core 10 is fitted into the core. Therefore,
The bobbin 4 is regulated so as not to move in the vertical and horizontal directions, and is accurately positioned around the armature axis E.

The core 10 has a first function of collecting the magnetic flux generated by the armature coil 6 and passing it between the magnetic flux path members 15, 15a, 15b and the base 12 (that is, the core of the armature 7 (iron core)). ), And a second function of passing the magnetic flux generated by the field 3 between the magnetic flux path members 15, 15a, 15b and the base 12 (that is, forming a part of the passage of the magnetic flux 2). Function). Magnetic flux path member 15,
The magnetic flux 2 passing through 15a and 15b concentrates on the core 10 having a particularly small sectional area as compared with the other members of the motor 1 (FIG. 2).
Arrow F2). Therefore, it is necessary to configure the core 10 so that the magnetic flux density is not saturated at the core 10. Further, the core 10 includes the magnetic flux path members 15, 15a,
A third function is to hold the bobbin 4 in which the armature coil 6 is housed, and a fourth function is to hold the bobbin 4 in which the armature coil 6 is housed, by holding the 15b on the base 12 by holding the 15b with the flange portion 53.

The core 60 according to the comparative example shown in FIGS. 7A and 7B has the same four functions as the core 10 of the present invention. It is integrally formed in the shape. The plate thickness t1 of the bottom 51 of the core 60 is
It is almost the same as the thickness of the material. However, because of the deep drawing, the tubular portion 61 is formed by being elongated, and the plate thickness t2 of the tubular portion 61 is smaller than the plate thickness t1 of the bottom portion 51. As a result, the cross-sectional area of the cylindrical portion 61 is reduced. When the magnetic flux 2 passes through the cylindrical portion 61 substantially in parallel with the central axis CL1, eddy currents A1 and A2 are generated, and eddy current loss occurs. The eddy current loss is “Joule loss caused by eddy current induced so as to prevent the fluctuation of the magnetic flux when the magnetic flux changes in the metal”. The eddy current includes a small eddy current A1 and a large eddy current A2 flowing around the center axis CL1.

In the core 60, since the cross-sectional area of the cylindrical portion 61 is small, the maximum magnetic flux density of the magnetic flux 2 passing through the cylindrical portion 61 is large. As a result, a large eddy current loss occurs. Since the gap G (FIG. 4B) as in the present invention is not formed, the eddy current loss due to the large eddy current A2 is particularly large. Further, if the core 60 is deep drawn, the thickness t2 of the cylindrical portion 61 becomes thin, so that the dimension (height dimension) H of the core 60 in the direction of the central axis CL1 cannot be increased so much. On the other hand, if the thickness of the material is increased in order to increase the thickness t2, deep drawing becomes difficult, and the thickness of the flange portion 62 also increases.
As a result, even when the number of turns of the winding 5 is increased to improve the performance of the small motor 1, the height 60 of the core 60 is limited, so that it is difficult to freely change the design. In addition, because of the deep drawing, the structure of the mold is complicated and the punching speed is low.

On the other hand, the core 10 of the present invention shown in FIGS. 1 to 4 is formed by bending a bent piece 50. Therefore, the core 10 can be easily manufactured with a mold having a simple structure, and the processing speed (the time required for processing one core) is several times (for example, three to five times) faster than the deep drawing. Since the core 10 is formed by bending, when the bottom portion 51 has a plate thickness t1, the cylindrical portion 52 is formed.
Have substantially the same plate thickness t1. That is, the thickness t1 of the tubular portion 52 of the present invention is larger than that of the tubular portion 61 of the core 60 formed by deep drawing. Therefore, the cross-sectional area of the cylindrical portion 52 can be increased. This allows
By reducing the maximum magnetic flux density of the magnetic flux 2 passing through the cylindrical portion 52,
The magnetic flux density can be prevented from being saturated and the eddy current loss can be reduced. Further, a gap G is formed in the core 10 so that adjacent bent pieces 50 are separated from each other. As a result, when compared with the core 60 of the comparative example, the small eddy current A1 may not be so different, but the large eddy current A2 (see FIG.
(B)) does not flow. As a result, eddy current loss can be significantly reduced.

Further, by increasing the number of turns of the winding 5,
In the case of improving the performance of the core 10, the bending height is changed to a desired height dimension H by simply changing the punching dimension of the rising portion of the bent piece 50 punched into a plurality of petal radial shapes at the time of bending. The design can be changed. Core 1
The height t of the cylindrical portion 52 can be increased even if the height H of 0 is increased.
Does not become thin. Further, since the cross section of the core 10 is substantially hexagonal and the chamfered portion 58 is also formed, the core 10 can be fitted along the inner peripheral surface 38 a of the bobbin 4. Bobbin 4
Can be formed into a cylindrical shape, so that the winding 5 can be laminated and wound, and as a result, the armature coil 6 with a small space and a high density can be formed. Flange part 5
Numeral 3 extends in a petal shape radially outward. Therefore, the contact area with the second plate-like portions 28 and 29 increases, so that the magnetic flux 2 can be satisfactorily passed through the contact portions. Further, since the bent pieces 50 are separated from each other, the core 10 also exerts a heat radiation effect.

FIG. 8 shows experimental data of the motor M1 of the present invention having the core 10 shown in FIGS. 1 to 4 and the motor M2 of the comparative example having the core 60 of the comparative example shown in FIG. ing. The two motors M1, M2 have a core 10,
Configurations other than 60 are exactly the same. 8, the horizontal axis represents the rotation speed of the motors M1 and M2, the left vertical axis represents the no-load current, and the right vertical axis represents the power. In the figure, curves I1 and W1 indicate the no-load current and power of the motor M1, respectively. Curves I2 and W2 show the no-load current and power of the motor M2, respectively. In this experiment, the motors M1 and M2 were operated under no load, the applied voltage was changed to change the rotation speed of the motors M1 and M2, and the no-load current and power (power = applied voltage x current) at each rotation speed were measured. did. Motor M1, M2
Was measured three times each, and the average of the three measurements is shown in the graph. Motor M1, M2 with no load
, The no-load current and the power
1, which corresponds to the no-load loss of M2 (effective input when the electric device is operated with no load). Therefore, the difference between the no-load current and the difference between the powers of the two motors M1 and M2 is
It can be seen that the difference in the configuration of the cores 10 and 60 (that is, mainly the difference in eddy current loss) is the cause.

A comparison of the curves I1 and I2 shows that the motor M1 of the present invention has a smaller no-load current than the motor M2 of the comparative example. On the other hand, regarding the electric power, when the curves W1 and W2 are compared, it can be seen that the electric power of the motor M1 is lower than that of the motor M2. Moreover, as the rotation speed increases, the difference between the motor M1 of the present invention and the motor M2 of the comparative example increases. This indicates that the core 10 of the present invention is particularly effective in a small motor having a high rotation speed (for example, a rotation speed of about 7,000 to about 8,000 min ^-1 ) which has been particularly required in recent years. . As described above, in the motor M1 of the present invention, the no-load current and the electric power are reduced as compared with the motor M2 of the comparative example. This is because in the core 10 of the present invention, the cylindrical portion 5
2 and a large eddy current A
This is because the occurrence of No. 2 was prevented, the eddy current loss was reduced, and the no-load loss was reduced. Therefore, the eddy current loss can be considerably reduced even if the core 10 does not have a laminated structure.

Next, first and second modifications of the present embodiment will be described with reference to FIGS. The same or corresponding parts as those of the above embodiment are denoted by the same reference numerals, and the description thereof will be omitted. Only different parts will be described. FIG.
A core 10a according to a first modified example shown in FIGS.
Is formed into a bottomed cylindrical shape by bending a plurality of plate-shaped integral bent pieces 50a. Core 10a
Has the same function as the core 10 and is integrally formed of a magnetic material. The core 10a is provided on the inner peripheral surface 3 of the bobbin 4.
8a along with the magnetic flux path members 15,
15a, 15b are magnetically connected. Core 10a
Has a central axis line CL1 and connects the base 12 and the members for magnetic flux paths 15, 15a, 15b. The core 10a
A substantially circular bottom portion 51a, a tubular portion 52a integrally formed from an outer peripheral edge of the bottom portion 51a and formed by a plurality of bent pieces 50a, and one end portion (here, an upper end portion) of the tubular portion 52a. And a flange portion 5 which is integrally bent outwardly in the radial direction and is constituted by a plurality of bent pieces 50a.
3a. The bottom portion 51a is fixed to the base 12, and the flange portion 53a is provided with the magnetic flux path members 15, 15a,
15b is magnetically engaged. The bobbin 4 has a base 12
And the magnetic flux path members 15, 15a, 15b.

In the core 10a, the cross-sectional shape of the cylindrical portion 52a is substantially circular (FIG. 5B). Therefore, before forming (or after forming) the tubular portion 52a and the flange portion 53a, it is necessary to bend the bent piece 50a into a circle around the center axis CL1. Tubular part 52
a, the outer peripheral surface of the cylindrical portion 52a is brought very close to the inner peripheral surface 38a of the bobbin 4 so that the bobbin 4
Can be satisfactorily passed through the cylindrical portion 52a. A gap G is formed between adjacent bent pieces 50a. Further, the plurality of bent pieces 50a are connected to the central axis line CL1.
Are arranged almost evenly around. Accordingly, the plurality of gaps G are formed radially outward at substantially the same angle apart from the center axis CL1 and have substantially the same gap dimension d. Also in this core 10a, the same operation and effect as in the above-described embodiment are exerted.

A core 10b according to a second modification shown in FIGS. 6A and 6B has the same function as the core 10, and is integrally formed of a magnetic material. The core 10b is
It fits along the inner peripheral surface 38a of the bobbin 4 and is magnetically connected to the magnetic flux path members 15, 15a, 15b. The core 10b is formed in a bottomed cylindrical shape by bending a plurality of (six in this case) bent pieces 50b which are plate-shaped and integral. The core 10b has a central axis CL
1 and the base 12 and the magnetic flux path members 15, 15a, 1
5b are connected. The core 10b includes a substantially polygonal (here, hexagonal) bottom portion 51b, a tubular portion 52b integrally formed from an outer peripheral edge of the bottom portion 51b, and a plurality of bent pieces 50b. The end portion 52b has a flange portion 53b that is integrally bent outward from the one end (the upper end in this example) in the radial direction and includes a plurality of bent pieces 50b. The bottom portion 51b is fixed to the base 12, and the flange portion 53b is provided with the magnetic flux path members 15,15.
a and 15b are magnetically engaged. The bobbin 4 is disposed between the base 12 and the magnetic flux path member. The cross-sectional shape of the cylindrical portion 52b is substantially polygonal (here,
Hexagon).

In the core 10b, the bent piece 50b is
It is not necessary to process into a curved surface as shown in (B).
It is not necessary to form the facing surface 55 (or 56) and the chamfered portion 58 as shown in FIG. Therefore, it can be manufactured more easily than the cores 10 and 10a. Although no gap is formed between the adjacent bent pieces 50b, the bent pieces 50b are in point contact or line contact or slightly apart, so that eddy current loss can be reduced to some extent. For other effects,
It is the same as the cores 10 and 10a.

As shown in FIGS. 1 and 2, in the motor 1, the windings 5 are respectively wound around a plurality of armature axes E parallel to the rotation center axis CL. as a result,
The magnetic flux passage 43 is three-dimensionally bent a plurality of times in a direction substantially parallel to the rotation center axis CL, a direction substantially perpendicular to the rotation center axis CL, and a predetermined direction. As a result, the dimension D in the bulk direction of the winding portion that increases or decreases according to the number of turns of the winding 5 changes in a direction orthogonal to the rotation center axis CL.
Can be increased. The output torque of the motor 1 is proportional to the product of the amount of magnetic flux interlinked with the winding 5 generated by the magnets 26 and 26a, the number of turns of the winding 5, and the current flowing through the armature 7. According to the present invention, the number of turns of the winding 5 can be increased as desired, so that the cost can be reduced by using the low-performance magnets 26 and 26a without increasing the amount of magnetic flux by using an expensive high-performance magnet. Thus, a desired output torque can be obtained. The number of windings of the winding 5 can be increased without increasing the dimension (total length of the motor) in the direction parallel to the rotation center axis CL of the motor 1. Therefore, the overall thickness of the motor 1 can be reduced, and the output torque can be increased to a desired value.

According to the motor 1 configured as described above, the shape of the base 12 and the position of the rotation center axis CL can be freely adjusted and designed according to the space for mounting the motor 1. This allows the entire motor to have any shape,
The motor can be set well in the space. In the present invention, the dimension D in the bulk direction of the winding portion can be changed radially outward by the number of turns of the armature winding. Therefore, like the motor 1, the radial shape of the base 12 can be freely designed. Motor 1
At the time of manufacturing the magnetic flux path members 15, 15a, 15b
Can be separated from the base 12 respectively. Therefore, after winding the winding 5 around each bobbin 4, the bobbin 4 and the magnetic flux path members 15, 15a, 15b can be easily attached to the base 12. Thereby, the rotation center axis C
Even if the motor L is eccentric from the center of the base 12, the winding 1 can be easily wound around the bobbin 4 and the motor 1 can be easily manufactured.

In this embodiment, a plurality of armature axes E
Shows a case in which it is arranged at an arbitrary position around the rotation center axis CL. As another example, the rotation center axis CL is disposed, for example, at the center of a circular base, and a plurality (for example, three) of armature axes E are separated by the same angle about the rotation center axis CL, and , Rotation center axis C
There is a case where they are arranged at the same distance (radius) from L. In the present embodiment, a plurality of magnets 2 forming the field 3
6, 26a are arranged continuously. It should be noted that there may be a case where there is a space between adjacent magnets. In this case, the field surface forming a gap in opposition to the armature has a partially cylindrical shape. This field surface is also included in the cylindrical surface of the field in the present invention. Although the armature axis E has been described as being parallel to the rotation center axis CL, the armature axis E may be slightly inclined or substantially parallel to the rotation center axis CL. Although the case where the first plate-shaped portion 12a and the second plate-shaped portions 28 and 29 are formed of flat plates having a uniform thickness has been shown, a plate having a taper, or the flat plate or the tapered plate is used. It may be a slightly twisted plate.

According to the present invention, it is possible to increase the volume of the winding part by increasing the number of turns of the winding 5. Therefore, for example, the present invention can provide a motor having an optimal structure in a case where there is room for expanding the outer dimensions of the motor in a radially outward direction, and there is a strong demand for a reduction in the thickness and cost of the entire motor. it can. Further, since the number of turns of the armature winding can be easily increased, the output torque can be increased to a desired value, and the motor characteristics can be improved.

The small motor of the present invention may be a stepping motor in addition to the above-described brushless motor 1. Further, as long as it is a small motor having a bobbin and a bottomed cylindrical member, an AC motor may be used in addition to a DC motor. In the present embodiment, the motor 1 in which the bobbin 4 of the armature 7 and the cores 10, 10a, 10b are provided on the stator side.
However, a small motor having a bobbin and a core provided on the rotor side may be used. That is, the armature having the bobbin and the core may or may not rotate, and is not limited to a small motor having a specific number of poles or grooves. In the drawings, the same reference numerals indicate the same or corresponding parts.

[0040]

Since the present invention is constructed as described above, it is possible to easily manufacture a bottomed cylindrical member for passing a magnetic flux by fitting it into the hollow body of the bobbin. Eddy current loss in the shape member can be reduced.

[Brief description of the drawings]

1 to 8 show an example of an embodiment of the present invention, and FIG. 1 is a front view of a small motor.

FIG. 2 is a sectional perspective view taken along line II-II of FIG.

FIG. 3 is a perspective view showing an outer shape of a bottomed tubular member of the present invention.

FIG. 4 is a sectional view of the bottomed tubular member.

FIG. 5 is a cross-sectional view of a bottomed tubular member according to a first modification of the present embodiment.

FIG. 6 is a cross-sectional view of a bottomed tubular member according to a second modification of the present embodiment.

FIG. 7 is a sectional view of a bottomed tubular member according to a comparative example of the present invention.

FIG. 8 is a graph showing experimental data of the present embodiment.

[Explanation of symbols]

 Reference Signs List 1 small motor (motor) 2 magnetic flux 3 field 4 bobbin 5 armature winding 6 armature coil 7 armature 8 cylindrical surface (field surface) 10, 10a, 10b bottomed cylindrical member 12 base 15, 15a, 15b Magnetic flux path member 16, 30 Rotor facing part 38 Hollow body part 38a Inner peripheral surface 50, 50a, 50b Folded piece 51, 51a, 51b Bottom part 52, 52a, 52b Cylindrical part 53, 53a, 53b Flange part 54 Upper end (one end of the cylindrical portion) B Gap CL Rotation center axis CL1 Center axis of bottomed cylindrical member E Armature axis G Gap

Continued on front page F term (reference) 5H002 AA04 AA09 AB02 AB05 AB06 AC06 AE07 AE08 5H604 AA08 BB01 CC02 PB03 PC05 PD02 QA01 QA03 QB04 5H621 GA02 GA07 GA14 GA16 GA17 GB10 JK02 JK04 JK05 JK07 5H622 CA01 CA05 PP

Claims (7)

[Claims] A field (3) for generating a magnetic flux (2);
An armature (7) in which an annular armature coil (6) is formed by winding an armature winding (5) in a coil shape around each of the plurality of bobbins (4); A gap (B) is formed between a rotor facing portion (16, 30) of a plurality of magnetic flux path members (15, 15a, 15b) formed of a magnetic material and a surface (8) of the field (3). ) Is formed, and one of the field (3) and the armature (7) is rotated by the rotation center axis (C
L), wherein the bobbin (4) has a cylindrical hollow body (38) for winding the armature winding (5). A bottomed cylindrical member (10, 10a, 10b) integrally formed of a magnetic material and having at least a function of passing the magnetic flux (2) and a function of positioning the bobbin (4); 4) The inner peripheral surface (38a) of the hollow body (38)
And is magnetically connected to the magnetic flux path member. The bottomed cylindrical member (10, 10a, 10b) is a plate-shaped integral bent piece (50, 50a, 50b) is formed by bending the small motor. 2. The field (3) rotates, and the armature (7) is attached to a base (12) provided on a stator side and formed of a magnetic material, and the bottomed cylindrical member is provided. (10, 10a, 10b) has a central axis (CL) in a direction substantially parallel to the rotation central axis (CL).
2. The small motor according to claim 1, further comprising: 1), wherein the base (12) and the magnetic flux path members (15, 15 a, 15 b) are connected. 3. The bottomed tubular member (10, 10a, 10
b) is a substantially circular or substantially polygonal bottom (51, 51).
a, 51b) and a tubular portion (52, 52a, 52b) integrally formed from the outer peripheral edge of the bottom portion and constituted by the plurality of bent pieces (50, 50a, 50b). A flange portion (53, 53a, 53b) formed integrally from one end of the cylindrical portion radially outward and formed by the plurality of bent pieces; The flange portion is fixed to the base (12), the flange portion magnetically engages with the magnetic flux path member, and the bobbin is disposed between the base and the magnetic flux path member. The small motor according to claim 2, wherein: 4. The cylindrical member having a bottom (10, 10a, 10a).
4. The small motor according to claim 3, wherein the cross-sectional shape of the cylindrical portion (b) is substantially circular or substantially polygonal. 5. The small motor according to claim 1, wherein a gap (G) is formed between the adjacent bent pieces (50, 50a). . 6. A center axis (CL1) of the plurality of bent pieces (50, 50a) of the bottomed tubular member (10, 10a).
Are arranged substantially evenly around the center axis (C) of the bottomed tubular member.
6. The gap according to claim 5, wherein the gaps are radially formed radially outward at substantially the same angle about L1), and the gaps have substantially parallel gaps. Small motor. 7. The small motor (1) includes a winding (5) of the armature (7) arranged around a plurality of armature axes (E) substantially parallel to the rotation center axis (CL). The small motor according to any one of claims 1 to 6, wherein each of the small motors has a wound configuration.