JPH099603A - Stepping motor and its manufacture - Google Patents

Abstract

PURPOSE: To provide a stepping motor in which the shape of the cup of a stator can be changed, in which the productivity of the cup can be enhanced and which can reduce the number of production processes and production costs. CONSTITUTION: A stator 21 which is arranged around a rotor is constituted of two stator units 32 which are provided with a coil body 33, with cups 35 and with a plate 40. The cups 35 are provided with lid parts 36 which cover one end of the coil body 33, with an outer circumferential wall part which covers the outer circumferential face of the coil body 33 and with a plurality of magnetic pole teeth 38 which cover the inner circumferential face of the coil body 33. The plate 40 is provided with a lid part 41 which covers the other end of the coil body 33 and with a plurality of magnetic pole teeth 42 which are arranged by keeping an interval from the magnetic pole teeth 38 at the cup 35. The cups 35 are provided with insertion and passage recessed parts 37a which are formed from the tip of the outer circumferential wall part up to the lid part 36 in order to insert and pass a terminal part 33c protruding from the coil body 33 and with cutouts 37c which are arranged in symmetric positions of the insertion and passage recessed parts 37a and which are extended up to the lid part 36 from the tip of the outer circumferential wall part.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a step motor used for a flow control valve or the like for controlling an idle speed of an internal combustion engine, and more particularly to a PM type (permanent magnet) having a plurality of magnetic pole teeth arranged on a stator. Shape) relates to a step motor.

[0002]

2. Description of the Related Art A conventional stepping motor is known from Japanese Patent Application Laid-Open No. 63-274355, and a stator is arranged around a rotor in which permanent magnets are arranged. As shown in FIG. 9, the stator 1
However, it is composed of two substantially cylindrical stator units 2.2 that are laminated along the axial direction of the rotor.

Each stator unit 2 has a cylindrical coil body 3, a cup 5 and a plate 10.

As shown in FIGS. 9 and 10, the cup 5 has an annular lid portion 6 for covering one end face of the coil body 3, and a lid portion 6.
An outer peripheral wall portion 7 extending from the outer peripheral edge of the coil body 3 to cover the outer peripheral surface of the coil body 3, and a plurality of magnetic pole teeth 8 extending from the inner peripheral edge of the lid portion 6 to cover the inner peripheral surface of the coil body 3. Along with
The terminal portion 3 protruding from the coil body 3 on the outer peripheral wall portion 7.
It was provided with an insertion recess 7a for inserting c. In addition, 6a
Is a positioning hole into which a positioning protrusion (not shown) protruding from the coil body 3 is inserted, and 7b is a fitting concave portion into which the fitting convex portion 11a provided on the lid portion 11 of the plate 10 is fitted. Further, 11b and 11c are a positioning hole and a positioning protrusion for positioning with the plate 10 of the other stator unit 2.

The plate 10 has an annular lid portion 11 that covers the other end surface of the coil body 3, and extends from the inner peripheral edge of the lid portion 11 to cover the inner peripheral surface of the coil body 3 and the magnetic pole teeth 8 of the cup 5. And a plurality of magnetic pole teeth 12 arranged at intervals.

To manufacture the cup 5, as shown in FIG. 11, an iron plate is punched into a predetermined disk shape, drawn, cut at the peripheral edge, and then the peripheral edge is raised to adjust the shape.
Further, after the shape of the magnetic pole tooth 8 and the positioning hole 6a are punched out, the insertion recess 7a and the fitting recess 7b are cut, and then each magnetic pole tooth 8 is bent and manufactured.

Further, the plate 10 is punched from an iron plate while forming the shape of each magnetic pole tooth 12 in the expanded state, the fitting recess 11a, the positioning hole 11b, and the positioning protrusion 11c, and bending each magnetic pole tooth 12. Was manufactured.

Further, the coil body 3 is manufactured by winding a coil wire 3b around a bobbin 3a made of synthetic resin and arranging the terminal portion 3 therein.
It was manufactured by connecting to c and molding the synthetic resin covering portion 3d.

The stator 1 is manufactured by manufacturing the coil body 3
The two stator units 2 formed by housing the cup 5 and the plate 10 on the outside are set in the mold of the synthetic resin housing 18 with the cover 14 and the guide 16 arranged, and the housing 18 is injected. It was formed by molding and manufactured.

[0010]

However, in the conventional step motor, since the cup 5 is manufactured by utilizing the drawing process, the processing energy becomes large, and after the drawing process, the cup 5 is not formed. Since the shapes of the magnetic pole teeth 8 and the insertion recesses 7a were formed by various molds with a substantially external shape, it was difficult to produce them by continuous press working, and the productivity was poor.

The present invention is to solve the above-mentioned problems, and changes the shape of the cup of the stator, improves the productivity of the cup, and reduces the number of manufacturing steps and the manufacturing cost, and the manufacturing thereof. The purpose is to provide a method.

[0012]

A step motor according to the present invention comprises a plurality of substantially cylindrical stators in which stators arranged around a rotor provided with permanent magnets are laminated in the axial direction of the rotor. Each stator unit is configured to include a cylindrical coil body, a cup, and a plate, and the cup has an annular lid portion that covers one end surface of the coil body. When,
An outer peripheral wall portion extending from an outer peripheral edge of the lid portion to cover an outer peripheral surface of the coil body; and a plurality of magnetic pole teeth extending from an inner peripheral edge of the lid portion to cover an inner peripheral surface of the coil body. Along with the outer peripheral wall portion, an insertion recess for inserting the terminal portion protruding from the coil body is provided, and the plate has an annular lid portion that covers the other end surface of the coil body,
A step motor configured to include a plurality of magnetic pole teeth extending from an inner peripheral edge of the lid portion to cover an inner peripheral surface of the coil body and spaced apart from the magnetic pole teeth of the cup, The cup is provided with the insertion recess from the tip of the outer peripheral wall to the lid, and has a notch extending from the tip of the outer peripheral wall to the lid at a symmetrical position of the insertion recess. Characterize.

In the manufacturing method of the present invention, as the manufacturing of the cup of the stator, the outer peripheral wall is formed from the flat state in which the lid and the outer peripheral wall are connected to each other, and the insertion recess and the A notch that is disposed at a symmetrical position of the insertion recess and extends from the tip of the outer peripheral wall to the lid is punched out, and then the outer peripheral wall is bent by bending. Characterize.

Further, in the step motor according to the present invention, the stator unit arranged on the end face side is arranged on the outer side of the cup, the stator units are laminated on each other, and the end face side is formed. A cover for covering the insertion recess and the notch is arranged on the outer side of the cup lid portion of the stator unit, and each of the stacked stator units is injection molded with the gate portion arranged on the end face side. It is desirable to embed it in a synthetic resin housing formed by.

[0015]

In the step motor according to the present invention, the cup is
The insertion recess provided in the outer peripheral wall is provided from the tip of the outer peripheral wall to the lid, and a notch extending from the end of the outer peripheral wall to the lid is provided at a symmetrical position of the insertion recess.

Therefore, in the manufacture of the cup, the outer peripheral wall portion is formed such that the outer peripheral wall portion is formed in a flat plate-like expanded state in which the lid portion and the outer peripheral wall portion are connected to each other, and the outer peripheral wall portion is formed at the symmetrical position of the insertion concave portion and the insertion concave portion. After punching out an unnecessary portion for forming the notch extending from the tip of the wall portion to the lid portion, and then bending the outer peripheral wall portion by bending, an outer peripheral edge of the lid portion can be formed without using drawing. The raised outer peripheral wall portion can be easily formed.

Particularly, when bending the outer peripheral wall portion, the outer peripheral edge of the lid portion is bent so as to form an arc surface. The bendable outer peripheral wall portion is provided in advance from the tip of the outer peripheral wall portion to the lid portion. Since the unnecessary portion for forming the insertion concave portion and the notch provided at the symmetrical position to the outer peripheral wall portion from the tip of the outer peripheral wall portion to the lid portion is punched out, the bendable outer peripheral wall portion is wrinkled. It can be neatly processed without causing it.

As the stator, the stator unit arranged on the end face side is arranged with the cup on the outer side,
When the stator units are stacked on top of each other and a synthetic resin housing is formed around them by injection molding, a molding die for molding the peripheral edge of the terminal portion and forming a recess for arranging the rotor is used. Depending on the design, the gate part of the mold may be placed on the end face side of the stacked stator units.In that case, insert it on the outer side of the cup lid part of the stator unit on the end face side. A cover covering the recess and the notch is arranged and molded.

That is, in the lid portion of the cup arranged on the outer side of the stator unit on the end face side, the end portions of the insertion concave portion and the notch formed from the cup outer peripheral wall portion are open, and these Since the cover covers the opening, it is possible to prevent the molding material from directly injecting the coil body with injection pressure when the housing is molded.

[0020]

An embodiment of the present invention will be described below with reference to the drawings.

As shown in FIG. 6, the step motor M of the embodiment is used as a flow rate control valve V for controlling the idle speed of the internal combustion engine, and the flow rate control valve V is connected to the bypass line 21. The separation distance from the valve seat 21a is the valve body 23
Is to be adjusted.

Then, the rotor 30 of the step motor M
Is configured to move the valve shaft 24 having the valve body 23 arranged at the tip. Specifically, the rotor 30
Arranges a permanent magnet on the outer peripheral surface and
The valve shaft 24 is provided with a female screw corresponding to the male screw. Reference numeral 26 is a lid member fixed to a guide 46 fixed to the housing 48, 27 is a compression coil spring, and 28 is a bearing that rotatably holds the rotor 30. When the rotor 30 rotates by a predetermined angle, the valve shaft 24, the rotation of which is restricted by the through hole 26 a of the lid member 26, moves back and forth from the lid member 26.

As shown in FIGS. 1, 2, and 6, the stator 31 of the embodiment has two substantially cylindrical stator units 32 which are laminated along the axial direction of the rotor 30 as in the conventional case.
(32A / 32B), each stator unit 32 has a cylindrical coil body 33.
And a cup 35 and a plate 40. Stator unit 32A arranged on the end face side
Places the cup 35 on the outer side.

Further, each coil body 33 also has the same structure as the conventional one.
A bobbin 33a made of synthetic resin, a coil wire 33b wound around the bobbin 33a, a terminal portion 33c connected to the coil wire 33b, and a synthetic resin such as polyamide coating the outer peripheral surface of the coil wire 33b and the terminal portion 33c. Cover 3
3d and.

Further, each plate 40 is also made of an iron plate as in the conventional case, and has an annular lid portion 41 for covering the end surface of the coil body 33, and the coil body 33 extending from the inner peripheral edge of the lid portion 41.
And a plurality of magnetic pole teeth 42 which are arranged at a distance from the magnetic pole teeth 38 of the cup 35, which will be described later. The lid 41 has a fitting projection 41a that fits into a fitting recess 37b of the cup 35, which will be described later, and a positioning hole 41b for positioning the adjacent plate 40.
The positioning protrusion 41c is formed.

Further, similarly to the conventional case, the cup 35 is also made of sheet metal, and has an annular lid portion 36 that covers one end surface of the coil body 33, and an outer periphery of the coil body 33 that extends from the outer peripheral edge of the lid portion 36. An outer peripheral wall portion 37 that covers the surface and a plurality of magnetic pole teeth 38 that extend from the inner peripheral edge of the lid portion 36 and cover the inner peripheral surface of the coil body 33 are configured.

Further, the outer peripheral wall portion 37 has a structure shown in FIGS.
As shown in FIG. 5, although the insertion recess 37a for inserting the terminal portion 33c protruding from the coil body 33 is formed, the insertion recess 37a is provided from the tip of the outer peripheral wall portion 37 to the lid portion 36, Opening 36b in the lid 36
Is formed.

Further, the outer peripheral wall portion 37 has an insertion recess 37.
A notch 37c extending from the tip of the outer peripheral wall portion 37 to the lid portion 36 is formed at a symmetrical position of a. This notch 37
c also has an opening 36c formed in the lid 36.

Reference numeral 36a denotes the bobbin 3 of the coil body 33.
Reference numeral 37b denotes a positioning hole into which a positioning protrusion (not shown) protruding from 3a is inserted.
It is a fitting concave portion into which the fitting convex portion 41a provided in is fitted.

Further, the stator unit 3 on the end face side is also provided.
A substantially annular cover 44 made of an iron plate is arranged outside the lid portion 36 of the cup 35 in 2A, and the two stator units 32A and 32B are covered with a housing 48 made of synthetic resin such as saturated polyester resin. The stator 31
Are formed.

The cover 44 is provided with a sleeve portion 44a slidably supporting the upper end of the rotor 30 at the center thereof, and the bending portion 4 which bends slightly downward along the entire circumference of the outer peripheral edge.
4b, and has a shape that covers the openings 36b and 36c of the lid portion 36.

Reference numeral 46 is a substantially cylindrical guide made of an iron plate, and press-fits and fixes the lid member 26.

Further, reference numeral 48a denotes a connector portion in which the terminal portions 33c of the two coil bodies 33 are assembled.
8b, the flow control valve V to the bypass line 21 bolt 22
It is a flange portion provided with a mounting hole 48c for stopping.

The manufacture of the step motor M of the embodiment will be described. Since the coil bodies 33, the plates 40, and the rotor 30 of the stator 31 are formed in the same manner as in the conventional case, the description thereof will be omitted.

The manufacture of each cup 35 of the embodiment is as follows.
As shown in FIG. 3, the tape-shaped iron plate material 50 is sequentially fed and pressed to be continuously formed.

That is, first, in the first step, a plurality of pilot holes 51 and alignment holes 52 are sequentially formed in the iron plate material 50, and in the second step, unnecessary parts are punched out. This time,
While cutting unnecessary portions 55 and 56 for forming the insertion recess 37a and the notch 37c of the outer peripheral wall 37,
The remaining material portion 53 and the product portion 54 are connected to four connecting portions 57, 57.
Connect at 58 and 59. The connecting portion 58 is arranged at a portion forming the insertion recess 37a, and the connecting portion 59 is
The cutout 37c is arranged at a portion forming the cutout 37c.

In the third step, the connecting portions 57, 57 are cut off, and the outer peripheral wall portion 37 is formed by bending. At this time, the outer peripheral edge of the lid portion 36 of the cup 35 to be manufactured is bent so as to form an arc surface, and the bendable outer peripheral wall portion 37 is provided in advance from the tip of the outer peripheral wall portion 37 to the lid portion 36. The unnecessary portion 5 is formed so as to form the insertion concave portion 37a and the notch 37c which is provided at the symmetrical position and is similarly provided from the tip of the outer peripheral wall portion 37 to the lid portion 36.
5 and 56 are punched out, leaving connecting portions 58 and 59 that can be treated as residual material in a later step, and connecting portions 58 and 59
Since 59 is not bent, the bent outer peripheral wall portion 37 can be neatly processed without causing wrinkles or the like.

Then, in the fourth step, surface pressing for dimensioning is performed, in the fifth step, the fitting recess 37b is cut and formed, and in the sixth step, the positioning hole 36a is formed in the lid 36 and A plurality of magnetic pole teeth 38 in a developed state are punched out and formed in the central portion of the product portion 54.

In the seventh step, the magnetic pole teeth 38 are formed by bending, and in the eighth step, surface pressing for dimensioning is performed, and in the ninth step, the tips of the connecting portions 58 and 59 are cut. Then, the cup 35 as a product is taken out.

The cup 35 manufactured in this manner is arranged on one end side of the coil body 33, which is manufactured in advance, and the plate 40 is arranged on the other end side of the coil body 33. And stack them on top of each other, and further cover 44 and guide 46
Is placed at a predetermined position and set on the set pin 62b of the split mold 62 in the mold opening state of the injection molding mold 60 shown in FIG. The molding die 60 has a predetermined die surface 61a.
Two split molds 61 and 62 with 62a and housing 4
8 and a slide core 63 forming the inner peripheral surface of the connector portion 48a, and the mold is opened and closed in the vertical direction shown in FIG.

After the stator units 32A, 32B, the cover 44, and the guide 46 are set in the mold 60 in the mold open state, the mold is clamped and the molding material for the housing 48 is injected into the cavity 60a from the gate portion 60b. After curing, if the mold is opened and released, the stator 31 can be manufactured.

By disposing the rotor 30 having the valve shaft 24 having the valve body 23, the lid member 26, the coil spring 27, and the bearing 28 assembled therein in the stator 31, the step motor M can be manufactured and The flow control valve V can be manufactured.

Thereafter, the flange portion 48 of the housing 48
The plurality of mounting holes 48c in
If stopped, the flow rate control valve V can be arranged at a predetermined position in the bypass conduit 21.

As described above, the step motor M of the embodiment is
In the cup 35, the insertion concave portion 37a provided in the outer peripheral wall portion 37 is provided from the tip of the outer peripheral wall portion 37a to the lid portion 36, and at the symmetrical position of the insertion concave portion 37a, from the tip of the outer peripheral wall portion 37 to the lid portion 36. It has a notch 37c extending up to.

Therefore, in the manufacture of the cup 35, the outer peripheral wall portion 37 is formed so that the insertion concave portion 37a and the insertion concave portion 37a are symmetrical with respect to each other from the flat plate-like expanded state in which the lid portion 36 and the outer peripheral wall portion 37 are connected. After punching out unnecessary portions 55 and 56 for forming the notch 37c which is arranged at the position and extends from the tip of the outer peripheral wall portion 37 to the lid portion 36, the outer peripheral wall portion 37 is formed.
Since the bending can be performed by bending, the outer peripheral wall portion 37 raised from the outer peripheral edge of the lid portion 36 can be easily formed without using conventional drawing processing.

In particular, as shown in steps 2 and 3 of FIG.
When bending the outer peripheral wall portion 37, the outer peripheral edge of the lid portion 36 is bent so as to form an arc surface. The bendable outer peripheral wall portion 37 is provided in advance from the tip of the outer peripheral wall portion 37 to the lid portion 36. The insertion recess 37a and the notch 37c that is provided at the symmetrical position and is similarly provided from the tip of the outer peripheral wall 37 to the lid 37 are formed.
6 is punched out, leaving connection parts 58 and 59 that can be treated as residual materials in a later step, and these connection parts 58 and 59.
Since it is not bent, it can be neatly processed without causing wrinkles or the like on the bendable outer peripheral wall portion 37.

Therefore, in the step motor M and the method of manufacturing the same of the embodiment, when the cup 35 is manufactured, the tape-shaped iron plate material 50 can be sequentially fed to manufacture the cup 35, which improves the productivity. It is possible to reduce the manufacturing steps and manufacturing cost of the step motor M. By the way, compared with the conventional cup 5, in the cup 35 of the embodiment, the number of manufacturing steps can be reduced by 80%, and the manufacturing cost can be reduced by 80%. As for the step motor M, the number of manufacturing steps can be reduced by 5% and the manufacturing cost can be reduced by 5% as compared with the conventional case.

Further, in the step motor M of the embodiment,
As the stator 31, the stator unit 32A arranged on the end face side is arranged with the cup 35 on the outer side, the respective stator units 32A and 32B are laminated on each other, and the housing 48 made of synthetic resin is arranged around them. The molding die 60 is formed by injection molding, but at this time, the molding die 60 is designed in consideration of the molding of the connector portion 48a around the terminal portion 33c and the design of the molding die 60 for forming the recess 48d in which the rotor 30 is arranged. Although the gate portion 60b is disposed on the end face side of the laminated stator unit 32, the cover extends from the insertion recess 37a and the notch 37c to the outer side of the cup lid portion 36 of the stator unit 32A on the end face side. Part 36
A cover 44 is arranged to cover the openings 36b and 36c.

That is, the stator unit 32 on the end surface side
In the lid portion 36 of the cup 35 arranged on the outer side of A, the end portions of the insertion concave portion 37a formed by the cup outer peripheral wall portion 37 and the notch 37c are open, and the openings 36b thereof are formed.
-Since the cover 44 covers the 36c, the molding material is directly injected into the coil body 33 facing the gate portion 60b through the openings 36b and 36c at the time of molding the housing 48 through injection pressure (500 to 600 Kgf / cm ^2,) prevents the application of, it is possible to prevent damage to the coil body 33.

In order to obtain this effect, it is sufficient to cover the openings 36b and 36c facing the gate portion 60b. Therefore, as shown in FIG. 7, the openings 36b and 36c can be provided without providing the punch portion 44b. So that you can cover
A substantially annular cover 74 having an outer diameter slightly larger than the outer diameter of the coil body 33 may be used.

Further, when protecting the coil body 33 from the injection pressure, as shown in FIG.
The second cup 35 and the plate 40 may be reversed so that the openings 36b and 36c of the cup lid portion 35 are not exposed to the end face side. By the way, in this case, the positioning hole 41b and the positioning protrusion 41c may be provided on the cup 35 side to perform the alignment when the stator units 32 are stacked. In addition, the plate 40 includes
Since the opening that causes damage to the coil body 33 is not formed, it is possible to use a small cover 14 having a sleeve portion 14a capable of supporting the rotor 30 as in the conventional case.

In the manufacturing method of the embodiment, the iron plate material 5
In order to progressively process 0, the product part 54 is not completely punched out, but the remaining material part 53 and the connecting parts 57, 58, 59 are used.
The connection parts 57, 58,
The unnecessary portions 55 and 56 may be cut without providing 59, the product portion 54 may be punched out, and the product portion 54 may be held to bend the outer peripheral wall portion 37 or form the magnetic pole teeth 38. . In this case as well, since there is no drawing process as in the prior art, the effect of the present invention can be obtained, although the effect of reducing the manufacturing man-hours and cost of the cup is less than that of the manufacturing method of the embodiment in which progressive feeding is possible.

[0053]

As described above, in the step motor according to the present invention, since the cup has the predetermined insertion concave portion and the notch in the outer peripheral wall portion, the outer peripheral wall portion is formed during the manufacturing of the cup. From the flat plate-like developed state in which the lid and the outer peripheral wall are connected, after punching out the unnecessary part of the boundary between the insertion recess and the notch, if the bending is performed to bend the outer peripheral wall, drawing can be used. Even if it is unnecessary, the outer peripheral wall portion raised from the outer peripheral edge of the lid portion can be formed neatly and easily, the productivity of the cup can be improved, and the number of manufacturing steps and the manufacturing cost can be reduced.

Further, as a stator, if a cover for covering the insertion concave portion and the notch is arranged on the outer side of the cup lid portion of the stator unit on the end face side, the stator units are laminated on each other and When forming the synthetic resin housing around the by injection molding,
Even when arranged on the end face side of the laminated stator units, at the time of molding the housing, the gate portion, the opening of the end portion of the insertion recess and the notch provided in the lid portion of the stator unit on the end side, Since it is possible to prevent the molding material from directly injecting the coil body with injection pressure, the damage to the coil body can be prevented.

[Brief description of drawings]

FIG. 1 is a sectional view of a stator showing an embodiment of the present invention.

FIG. 2 is an exploded perspective view of a cup plate and a cover of each stator unit in the stator of the embodiment.

FIG. 3 is a plan view showing a manufacturing process of the cup of the embodiment.

FIG. 4 is a plan view showing a state before stacking the stator units of the embodiment and setting them in a mold.

FIG. 5 is a cross-sectional view showing a stator of the same embodiment at the time of molding.

FIG. 6 is a sectional view showing a mode of use of the step motor of the embodiment.

FIG. 7 is a perspective view showing a modified example of the cover.

FIG. 8 is a cross-sectional view showing a modified example of the stator.

FIG. 9 is a cross-sectional view showing a conventional stator.

FIG. 10 is an exploded perspective view of a cup plate and a cover of each stator unit in a conventional stator.

FIG. 11 is a diagram showing a conventional cup manufacturing process.

[Explanation of symbols]

 1.31 ... Stator, 2.32 ... Stator unit, 3.33 ... Coil body, 3c.33c ... Terminal part, 5.35 ... Cup, 6.36 ... Lid part, 7.37 ... Outer peripheral wall part, 7a. 37a ... Insertion concave part, 8.38 ... Magnetic pole tooth, 10.40 ... Plate, 11.41 ... Lid part, 12.42 ... Magnetic pole tooth, 14.44 ... Cover, 18.48 ... Housing, 30 ... Rotor, 37c ... Notch, 55, 56 ... Unnecessary portion, 60 ... Injection mold, 60b ... Gate portion.

Claims (3)

[Claims] 1. A stator arranged around a rotor having permanent magnets is composed of a plurality of substantially cylindrical stator units stacked along the axial direction of the rotor, and each stator unit is A cylindrical coil body, a cup, and a plate, wherein the cup extends from an outer peripheral edge of the annular lid portion that covers one end surface of the coil body, and An outer peripheral wall portion covering the outer peripheral surface of the coil body, and a plurality of magnetic pole teeth extending from the inner peripheral edge of the lid portion to cover the inner peripheral surface of the coil body, and the outer peripheral wall portion, An annular recess for inserting the terminal portion protruding from the coil body, the plate covering the other end surface of the coil body; and an inner recess of the coil body extending from an inner peripheral edge of the cover portion. Cover the circumference of the cup A magnetic pole tooth and a plurality of magnetic pole teeth spaced apart from each other, wherein the cup has the insertion recess from the tip of the outer peripheral wall portion to the lid portion. A step motor having a notch extending from the tip of the outer peripheral wall portion to the lid portion at a symmetrical position of the insertion recess. 2. A stator arranged around a rotor provided with permanent magnets is composed of a plurality of substantially cylindrical stator units stacked along the axial direction of the rotor, each stator unit being a cylinder. A coil body, a cup, and a plate, the cup body having an annular lid portion covering one end surface of the coil body, and the coil body extending from an outer peripheral edge of the lid portion. And a plurality of magnetic pole teeth that extend from the inner peripheral edge of the lid portion and cover the inner peripheral surface of the coil body, and the outer peripheral wall portion includes the coil. An annular recess that covers the other end surface of the coil body; and an inner peripheral surface of the coil body that extends from the inner peripheral edge of the cover portion. Cover the magnetic pole teeth of the cup A step motor manufacturing method comprising a plurality of magnetic pole teeth arranged at intervals, wherein the outer peripheral wall portion of the cup is formed by connecting the lid portion and the outer peripheral wall portion. After punching out an unnecessary portion for forming the insertion recess and the notch extending from the tip of the outer peripheral wall portion to the lid portion at the symmetrical position of the insertion recess from the flattened expanded state The step motor manufacturing method is characterized in that the step motor is formed by bending the outer peripheral wall portion. 3. The stator unit arranged on the end face side has the cup arranged on the outer side, and the respective stator units are stacked on each other, and the stator unit on the end face side is outside the cup lid portion of the stator unit. A cover that covers the insertion recess and the notch is arranged on one side, and the stacked stator units are formed by injection molding in which a gate portion is arranged on the end face side and are made of synthetic resin. The step motor according to claim 1, wherein the step motor is embedded inside.