JPH10164813A - Coil bobbin fixing structure for layer-built stepping motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a coil bobbin fixing structure for a layer-built stepping motor, by which an open circuit in a winding end which is caused by the loosening and minute displacement of a component can be avoided. SOLUTION: A coil bobbin 17 is composed of a pair of annular side plates 17a and 17b which are in parallel with each other and a cylindrical body part with which both the side plates 17a and 17b are linked coaxially with each other. The side plates 17a and 17b and the cylindrical body part are integrally molded and a terminal attaching part 17c is made to protrude from one of the side plates outward in a radial direction. When respective stators A and B are piled, the respective terminal attaching parts 17c are so assembled as to be adjacent to each other. Boss parts 17h are made to protrude from the respective terminal attaching parts 17c in axial directions opposite to each other. Linking protrusions 17i are provided on the side surfaces of the respective terminal attaching parts 17c which are not adjacent to each other and tapered parts are provided on the side surfaces of the respective terminal attaching parts 17c which are adjacent to each other.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stepping motor and, more particularly, to a structure for fixing a coil bobbin used in a laminated stator type stepping motor or the like.

[0002]

2. Description of the Related Art Generally, a stepping motor is provided with a stator core, a coil, a rotor and the like constituting a stator in a housing. As shown in FIG. 10, a coil 116 has a coil bobbin 117, a winding 116a, and a terminal 113. And the coil bobbin 11
7, a terminal mounting portion 117c is formed, and the terminal 113 is press-fitted into the terminal mounting portion 117c. Further, as shown in FIG. 9, the terminal 116b at the end of the winding 116a is fixed and electrically joined by being entangled with the terminal 113 and soldered.

In assembling the components constituting the stepping motor, for example, in a stepping motor having a claw pole structure in which the components are stacked without using screws or the like, a projection is provided on a housing and a coil bobbin.
Further, the stator core is provided with fitting holes for fitting with the respective protrusions, and the respective protrusions and the fitting holes are fitted and laminated. As described above, the protrusions provided on the housing and the coil bobbin are fitted with the fitting holes provided on the stator core, thereby restricting the radial direction, thereby preventing the coil from vibrating due to excitation.

Further, in the thrust direction, as shown in FIG.
a, and the ribs 118a regulate the stacked stators.

In order to further prevent the terminal 113 from being displaced, as shown in FIG.
12a, the coil 116 is laminated, and the terminal 11
3 is disposed in the groove 112a of the housing 112. A groove 112 is formed between the housing 111 and the housing 112.
a and holding the terminal 113 disposed therebetween. Thus, the terminal 113 is restricted in the radial direction in the groove 112a.

[0006] As shown in FIG.
The terminal 113 may be pulled out by an external force because a tapered surface 112b is formed in the groove 112a formed in the terminal 113, and the tapered surface 112b is engaged with the tapered surface 113a of the terminal 113 to prevent the terminal 113 from coming off. However, in the groove 112a, the terminal 11
3 can be fixed.

However, when assembling the stepping motor, when positioning the protrusion formed on the coil bobbin with the fitting hole of the stator core, a clearance is provided in consideration of dimensional tolerance, workability, and linear expansion. The clearance causes play in the coil bobbin and the terminal.

Alternatively, as shown in FIG.
A housing 112 on which the housing 2a is formed;
At the mating surface with No. 1, the gap Y
Can be. At this time, since the thickness of the connecting portion 117j located between the side surface 117b of the coil bobbin 117 having the terminal mounting portion 117c and the terminal mounting portion 117c is thin, the coil 116 is formed by the gap Y between the housing 112 and the housing 111. The terminal 113 attached to is displaced.

Due to the looseness of the coil bobbin and the terminal generated in the stepping motor and the minute displacement of the terminal, the winding end portion 116b
And the wire is broken at the end of the winding.

[0010]

SUMMARY OF THE INVENTION In view of the above problems,
As a technique for preventing the backlash in the circumferential direction, Japanese Utility Model Laid-Open No. 5-2
No. 3788 is disclosed. This can prevent rattling in the circumferential direction by combining coil bobbins having inclined surfaces formed in the same shape, but cannot reduce rattling occurring in the thrust direction.

[0011] Alternatively, as disclosed in Japanese Utility Model Laid-Open No. 5-72107, a technique for improving the strength and supporting strength of the terminal and preventing the terminal from bending or falling has been disclosed. Because of the thinness, it is not possible to reduce the play generated in the thrust direction.

Further, as shown in Japanese Patent Publication No. 8-12818, by stacking coil bobbins having the same shape and having a tapered surface, the coil bobbin is reduced in size, and the root of the terminal pin is supported by the coil bobbin. Although a technique of firmly supporting the terminal pin by a matching structure has been disclosed, disconnection due to stress applied to the winding terminal due to minute displacement of the coil bobbin and the terminal cannot be prevented.

An object of the present invention is to provide a structure for fixing a coil bobbin of a laminated type stepping motor, which can prevent rattling of parts and disconnection at a winding terminal due to minute displacement in the laminated type stepping motor.

[0014]

A fixed structure of a coil bobbin of a laminated stepping motor according to the present invention is a laminated stepping motor in which a stator and a rotor are disposed between an upper housing and a lower housing. The stator has a structure in which at least two layers of a coil bobbin around which a winding is wound and held by a stator core having a convex magnetic pole are laminated and positioned in the lower housing, and the stator has a convex magnetic pole. One concave stator core is provided, and a plurality of coil bobbins and a convex stator core having convex magnetic poles are stacked on the concave stator core. Each of the coil bobbins is coaxial with a pair of mutually parallel annular side plates. And a cylindrical body connected thereto is integrally formed, and one of the side plates projects radially outward. A terminal mounting portion is formed, and when the respective stators are stacked, the terminal mounting portions are assembled adjacent to each other, and each of the terminal mounting portions extends in a direction opposite to the body portion in the axial direction. Boss portions are provided, engagement protrusions are provided on side surfaces of each terminal attachment portion that are not adjacent to each other, and a taper portion is formed on an adjacent side surface of each terminal attachment portion. .

Preferably, the tapered portion is formed on at least a part of an adjacent side surface.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the laminated stepping motor of this embodiment, stators A and B and a rotor 19 are disposed between an upper housing 11 and a lower housing 12. The stators A and B are wound coil bobbins 1 with windings 16a.
7 is sandwiched between stator cores having convex magnetic poles, and at least two layers are laminated and positioned in the lower housing 12. The stator B includes one concave stator core 14 having a convex magnetic pole 14a, and a convex stator core 15 having a plurality of coil bobbins 17 and convex magnetic poles 15a is laminated on the concave stator core 14.

Each coil bobbin 17 has a pair of mutually parallel annular side plates 17a, 17b and side plates 17a, 17b.
b is coaxially connected to a cylindrical body portion 17g, and a terminal mounting portion 17c is formed on the side plate 17b so as to protrude outward in the radial direction. The terminal mounting portions 17c are assembled adjacent to each other, and each of these terminal mounting portions 17c is provided with a boss portion 17h extending in a direction opposite to the body portion 17g in the axial direction. Engagement projections 17i are provided on the non-adjacent side surfaces of the terminal mounting portions 17c, respectively.
A tapered portion 17m is formed on an adjacent side surface of c.

As described above, in the coil bobbin 17 assembled so that the terminal mounting portion 17c is adjacent between the upper housing 11 and the lower housing 12, the boss portion 17h is formed in the terminal mounting portion 17c, and the stator A And when the stator B is stacked, the height is higher than the upper end surface 14 e of the concave stator core 14.

Thus, in order to join the upper housing 11 and the lower housing 12, one of the housings is pressed against the other housing, so that the members constituting the housing and the stators A and B are in close contact with each other. As a result, the coil bobbin 17 and the terminal 13 rattle or cause a minute displacement due to the vibration of the coil bobbin 17 due to the excitation of the coil 16.
It is possible to prevent disconnection due to stress applied to the winding terminal portion 16b.

[0020]

An embodiment of the present invention will be described below with reference to the drawings. The members, arrangements, and the like described below do not limit the present invention, and can be variously modified within the scope of the present invention.

FIGS. 1 to 5 show a specific embodiment according to the present invention. FIG. 1 is an exploded perspective view of a laminated stepping motor, FIG. 2 is an explanatory view of a coil bobbin, and FIG.
, FIG. 4 is a sectional explanatory view of the stepping motor, and FIG. 5 is a D view of FIG.

As shown in FIG. 1, the stepping motor M of this embodiment has, in two housings 11 and 12, one concave stator core 14 having a convex magnetic pole 14a constituting a stator, and a convex magnetic pole 15a. It is configured by assembling the convex stator core 15 and the coil 16, the plate 18, the rotor 19, the outer gear 21 and the internal gear 22 constituting the reduction gear 20, and the like.

An output side housing (upper side in FIG. 1,
A hole 11a is formed in the upper housing 11 to expose an outer gear 21 that constitutes a reduction gear 20 described later. On both outer sides of the upper housing 11, various stepping motors M are provided. The engaging positioning protrusion 11b (only one is shown) when assembling to the apparatus is formed so as to project laterally.

A housing (lower side in FIG. 1, hereinafter referred to as "lower side housing") located on the side opposite to the output side 12
Is composed of an extended portion 12a and a cylindrical concave portion 12b which is continuous with the extended portion 12a and accommodates the stator. A bearing concave portion (not shown) is formed at the center of the concave portion 12b. I have. Two positioning projections 12d (only one is shown) are formed at predetermined positions on the bottom surface of the side wall in the cylindrical concave portion 12b.

Further, a rib 12h is formed on the side wall inside the cylindrical concave portion 12 so as to protrude in the vertical direction. In this example, the three ribs 12h are provided at substantially equal intervals. However, as described later, when the concave stator core 14 is fitted into the concave portion 12b, the concave stator core 14
The number of ribs 12h is not limited to three in this example, as long as it is held with a sufficient pressure input in b.

A notch 12e for positioning the terminal 13 is formed on the side opposite to the extension 12a. The positioning projection 12d of the present example is
2e is formed at a predetermined position.

The notch 12e for positioning the terminal 13 has a groove 1 for supporting the terminal 13.
2 g are formed, and the groove 1 supporting the terminal 13 is formed.
2g, the inner opening width X1 is formed larger than the outer opening width X2 as shown in FIG.

On the side walls 12i, 12i located on both sides of the groove 12g, engaging recesses 12j, 12 for engaging an engaging protrusion formed on a coil bobbin described later are formed.
j is formed.

On the upper surface of the four corners of the lower housing 12, projections 12f, 12f,... For engaging with holes of the upper housing 11 and attaching by heat caulking are formed at four places.

As shown in FIG. 5, the terminal 13 used in this embodiment has an outer portion 13 extending outside the housing 12.
The inner part 13b connected to the coil 16 is made larger and thicker than the inner part 13b and the outer part 13b.
An engagement portion 13c is formed at the boundary of a. The engaging portion 13c is configured to match the shape of the groove 12g so as to match the groove 12g formed in the cutout 12e of the lower housing 12.

As shown in FIG. 1, the stator is composed of two layers, a stator A and a stator B.
It has a so-called claw pole type structure composed of a convex stator core 15 and a coil 16.

The upper stator core A is a convex stator core 1
The lower stator core B is laminated so that the coil 16 is sandwiched between the lower stator cores 5.
The coil 16 is sandwiched between the stator core 4 and the convex stator core 15.

That is, there is one concave stator core 14 on the lower housing 12 side.
Reference numeral 4 designates a predetermined number (six in this example) of convex magnetic poles 14a formed at a predetermined interval (60 in this example) toward the inside of the recess by sheet metal working.
゜), and the height of the concave stator core 14 is
The height is substantially the same as that of the lower housing 12 and the coil 16
The height is slightly lower than the height when the convex stator cores 15 are stacked.

The convex stator core 15 is provided with the above-mentioned convex magnetic pole 1.
The same number of convex magnetic poles 15a as 4a are formed at regular intervals (60 ° in this example) by sheet metal working.

The concave stator core 14 is formed with a notch 14b for positioning the terminal 13, and has positioning holes having different diameters of 82.5 ° and 97.5 °.
Two portions are formed at intervals of ゜. Among the positioning holes, a large-diameter hole (not shown) is formed on the wall at the position of the magnetic pole 14a, and this hole is formed by two positioning protrusions formed on the lower housing 12. 12
d at a predetermined position, and the other two holes 14d engage with two projections formed on a coil bobbin 17 of the coil 16 described later.

The convex stator core 15 is formed with two engaging holes 15b, 15b opposed to each other at 180 ° so as to be biased toward one of the magnetic poles by 7.5 ° between the magnetic poles 15a. In the example, two notches 15c are formed at a position of 82.5 ° with respect to the engagement holes 15b toward the notch 12e of the lower housing 12 at the time of lamination.

These engaging holes 15b are provided with engaging projections 17e formed on a coil bobbin 17 of the coil 16 described below.
And the notch 15c engages with the engaging projection 17d formed on the mounting portion 17c of the terminal 13. Then, the phase difference between the convex magnetic poles (pole teeth) 14a and 15a of the stator core is set to 30 °.

The coil 16 of the present embodiment comprises a coil bobbin 17
It comprises a winding 16a and a terminal 13. The coil bobbin 17 includes a side surface 17a having the terminal 13 and a side surface 17b having no terminal 13, and a winding 16a is wound around a body 17g located between the side surfaces 17a and 17b.
, And the winding end is wound around the terminal 13.

On the side face 17a provided with the terminal 13,
A terminal mounting portion 17c for mounting the terminal 13 is formed, and an engagement protrusion 17 that is higher than the thickness of the convex stator core 15 is formed inside the terminal mounting portion 17c.
One d is formed. In addition, one projection 17 e that is higher than the thickness of the convex stator core 15 is also provided on the upper surface of the side surface 17 a having the terminal 13.

As shown in FIGS. 1 and 2, the side face 17b having no terminal 13 has a concave stator core 14
Two protrusions 17f, 17f, which are smaller than the thickness, are formed so as to be engaged with holes 14d, 14d formed in the concave stator core 14 and not engaged with the lower housing 12.

Further, a boss 17h is formed on the terminal mounting portion 17c. As shown in FIGS. 2 and 3, the boss portion 17h is provided with a terminal mounting portion 17h.
17c of the coil bobbin 16 on the surface 17k of FIG.
And project in the opposite direction in the axial direction.
In the terminal mounting portion 17c, engagement protrusions 17i are provided on side surfaces that are not adjacent to each other when the coil bobbins 17 are stacked as described later.

The engaging projection 17i is provided with a minute clearance so as not to hinder stacking in the housing case.

The height of the boss 17h is set from the following viewpoint. That is, when the upper and lower stator cores A and B are laminated and the upper housing 11 and the lower housing 12 are thermally caulked, the upper housing 11 and
By forming the boss portion 17h so that the height when the stator A and the stator B are stacked is higher than the space formed between the lower housing 12 and the upper housing 12 in the stepping motor assembly. There is a gap between the housing 11 and the lower housing 12.

Further, a tapered portion 17m is formed in the terminal mounting portion 17c on the surface opposite to the surface on which the engaging projection 17i is formed. When the upper and lower stators A and B are assembled at the tapered portion 17m, the coil bobbins 17 constituting the respective stators are stacked so that the tapered portions m are adjacent to each other.

As will be described later, the coil bobbin 17
Since a member having a certain degree of elasticity such as engineer plastic is used, the upper housing 11 can be pressed toward the lower housing 12 to join the two housings 11 and 12 together to perform thermal caulking. Boss part 17
As described above, the height of h is such that the upper housing 11 and the lower housing 12 can be joined to each other so that a pressing force exceeding the elastic force of the coil bobbin 17 is not applied to the coil bobbin 17 during assembly. It is set.

This is, as described above, the lower housing 12
After the upper stator A and the lower stator B are stacked therein, the plate 18 is placed on the upper stator A, and when the upper housing 11 is fixed to the lower housing 12, the upper and lower stators A, This is because B sufficiently sinks into the lower housing 12.

A plate 18 is provided between the upper housing 11 and the lower housing 12. The outer diameter of the plate 18 is substantially the same as that of the lower housing 12, and the plate 18 is made of a material containing carbon, for example, 70% polyphenylene sulfide and 30% carbon in this example. It is also a thing. That is, the plate 18 is formed with a hole 18a serving as a bearing for the rotor 19, and a side portion of the hole 18a is provided with a protruding shaft 18b and a protruding shaft 18b for supporting the internal gear 22 constituting the reduction gear 20. Internal gear 2 at base
2 is formed to support the boss 18c. Further, on the side of the boss 18c, a protruding shaft 18d for supporting the outer gear 21 and the boss 1 for supporting the outer gear 21 are provided.
8e are formed.

The rotor 19 of this embodiment has a rotor body 19a made of a plastic magnet, and the rotor body 19a.
And a rotor shaft 19b integrally formed. A gear portion 19c is formed on the output side of the rotor shaft 19b, that is, on the end side of the rotor shaft on the plate 18 side. The gear portion 19c meshes with an internal gear 22 of the reduction gear 20 described below.

The speed reducer 20 is composed of an internal gear 22 and an outer gear 21 each having two upper and lower gears. The internal gear 22 is supported by a protruding shaft 18b of the plate 18 and a boss 18c.

Next, the assembling of the members having the above-described configuration will be described with reference to FIG. In the assembly, first, the other components of the lower stator B are sequentially stacked in one concave stator core 14, and the respective components of the upper stator A are sequentially stacked. Then, the rotor 19, the plate 18, the reduction gear 2
0 and the upper housing 11 are laminated in this order.

First, the coil 16 is placed in one concave stator core 14, and a projection 17 f (not shown on the lower stator B side) formed on the coil bobbin 17 is engaged with a hole 14 d of the concave stator core 14. . Next, the convex stator cores 15 are stacked. At this time, the convex stator core 1
5 and the engagement protrusion 17e of the bobbin 17, and the notch 15c of the convex stator core 15 and the engagement protrusion 17d formed in the terminal mounting portion 17c. Thereby, in assembling the lower stator B, each magnetic pole 14a of the concave stator core 14 and each magnetic pole 15a of the convex stator core 15 can be arranged at a constant interval (30 ° in this example).

Next, when the upper stator A is assembled, the protruding stator core 15 is mounted on the protruding stator core 15 constituting the lower stator B in the opposite direction.
At this time, the engaging hole 15b of the convex stator core 15 is aligned with the projection 17e of the coil bobbin 17 forming the lower stator B, and the notch 1 of the convex stator core 15 is formed.
5c and terminal mounting portion 17 constituting lower stator B
The protrusion-shaped stator core 15 is positioned by matching with the engagement protrusion 17d formed in c.

Further, the coil 16 is placed. At this time, the protrusion 1 of the coil bobbin 17 in the lower stator B
7e, the engagement hole 1 of the convex stator core 15 which is not engaged.
5b and the protrusion 17 of the coil bobbin 17 of the upper stator A
e (not shown on the upper stator A side) and the engagement protrusion 1 formed on the terminal mounting portion 17c.
The coil 16 is positioned by aligning 7d (not shown on the upper stator A side) with the notch 15c of the convex stator core 15.

By stacking in this manner, the coil bobbins 17 constituting the upper stators A and B are stacked such that the respective terminal mounting portions 17c are adjacent to each other at the tapered portion 17m.

Next, the convex stator core 15 is connected to the convex magnetic pole 1.
Place it with 5a facing down. In this manner, similarly to the above-described stacking engagement with the coil, the upper stator A can also arrange the convex magnetic poles 15a of each convex stator core 15 at a constant interval (30 ° in this example). Each of the four stator cores can be stacked at a position shifted by a fixed interval (15 ° in this example).

Then, the rotor 19 is inserted through the washer 23 from the side of the rotor shaft without the gear 19c.

Next, the stator laminated as described above is placed in the lower housing 12 in the concave stator core 14.
Is pressed in with the concave portion facing upward. At this time, the notch 14 b of the concave stator core 14 is
e, and the projection 12d of the housing is engaged with the larger-diameter hole formed in the concave stator core 14. As described above, the concave stator core 14 is provided with a positioning hole. Since one of the diameters is larger than the other, it is possible to assemble without any mistake in assembling.

Next, the plate 18 is placed. At this time, in this example, the convex stator core 1 of the laminated stator is used.
5 is located closer to the plate 18 than the concave stator core 14.

Next, the internal gear 22 is connected to the protruding shaft 18b.
, And mesh with the gear 19 c of the rotor 19. Then, the outer gear 21 is supported by the protruding shaft 18d.

Finally, the upper housing 11 is placed, and the upper and lower housings are caulked by heat to integrate the upper and lower housings.

In the stepping motor of this embodiment, the boss 17h formed on the terminal mounting portion 17c is provided.
As a result, as shown in FIG.
Of the space formed between the housing 11 and the housing 12 is equal to or greater than the height h2 of the space formed between the housing 11 and the housing 12.

Therefore, before the upper housing 11 is placed and the upper and lower housings are thermally caulked, a small gap is naturally formed between the upper housing 11 and the lower housing 12. As described above, since the coil bobbin 17 is formed of a member having elasticity, if the upper housing 11 is pressed toward the lower housing 12, the upper housing 11 and the lower housing 12 can be easily joined. Yes, heat caulking may be performed in this state. Since the upper and lower housings 11 and 12 are thermally caulked while a slight pressing force is applied to the coil bobbin 17 as described above, the members constituting the respective stators are almost in close contact with each other inside the housings 11 and 12.

The components constituting the stator positioned between the upper housing 11 and the lower housing 12 having the above-described structure are in close contact with each other without any gap, so that there is no play in the coil bobbin 17 and the terminal 13. In addition, a minute displacement of the coil bobbin 17 and the terminal 13 can be avoided, and disconnection at the winding end 16b can be prevented.

Further, as described above, the coil bobbin 17 is provided with the engaging projection 17i, and the projection is formed so as to fit into the engaging recess 12j provided in the housing 12. When the stepping motor is assembled, the heights h1 of the stacked stators A and B are higher than the height h2 of the space formed by the housings 11 and 12, so that the housings 11 and 12 are heated. Stators A and B stacked by caulking and joining
Is pressed.

At this time, the tapered portions 17m formed on the terminal mounting portion 17c slide with each other, and the laminated stators A and B are brought into close contact with no gap and pressed against the housing 12 in the direction E in FIG. In the engagement portion with the coil 16, the engagement protrusion 17i formed on the terminal attachment portion 17c is pressed toward the housing 12. The engagement recess 12j thus formed in the housing 12
The engaging projection 17i is pressed against the
Is held in.

By the engagement between the engaging projections 17i and the engaging recesses 12j, the coil bobbin 17 can be held in both the thrust direction and the radial direction, and can be more securely assembled.

FIG. 6 is an explanatory view showing another embodiment of the terminal mounting portion 17c. In the above embodiment, the upper stator A
In addition, although an example is shown in which the side surface on the adjacent side in the terminal mounting portion 17c of the coil bobbin 17 constituting the lower stator B is formed in a tapered shape, in this embodiment, this side surface is formed in a stepped portion. At this time, the upper stator A,
B is pressed when the housings 11 and 12 are assembled by heat caulking and is securely held by the housing 12, so that it is necessary to partially provide a tapered portion.

Further, in the above embodiment, the terminals 13 are arranged side by side in the adjacent terminal mounting portions 17c. However, the present invention is not limited to this.

The engaging projection 17i formed on the coil bobbin 17 has a semicircular cross section in this embodiment, but has a rectangular or triangular cross section.
If it matches 2j, it may be formed in any shape.

In the above embodiment, the boss 17h for reducing the backlash in the thrust direction is formed on the terminal mounting portion 17c. However, the boss 17h may be provided on the housing 11, 12 side. Similarly, the engaging protrusion 17i may be formed on the housing 12 side, but in this case, an engaging recess engaging with the engaging protrusion formed on the housing 12 is formed on the terminal mounting portion 17c side. There is a need.

On the other hand, by adopting the method of attaching the winding end 16b to the terminal 13 as shown in FIG. 7, a structure that is more resistant to disconnection can be obtained. Next, a method of attaching the terminal will be described.

As shown in FIG. 7, a guide groove (recess) 40 is formed on the side surface of the terminal mounting portion 17c of the coil bobbin 17 around which the winding 16a is wound. The lead portion 16c, which is a portion between the winding start portion and the winding end portion of the winding 16a and the leading end of the winding, is inserted into the guide groove 40.
, And is loosely wound around a columnar projection 50, and then soldered to the terminal 13.

According to the above-described method, a part (intermediate portion) of the lead portion 16c of the winding 16a is wound around the winding-off projection 50 formed on the terminal mounting portion 17c.
The vibration of the lead portion 16c of 6a is prevented, and even if it vibrates, the amplitude of the vibration becomes extremely small because the abandonment protrusion 50 can be used as a node. Therefore, the durability up to fatigue failure can be remarkably improved by repeated bending of the winding 16a.

With the above configuration, in the stepping motor according to the present invention, the boss portion 17h is formed in the terminal mounting portion 17c, so that the coil 16 in the concave stator core 14 and the convex stator core 15
Is formed higher than the upper end surface of the concave stator core 14, and in order to join the upper housing 11 and the lower housing 12, one of the housings is pressed against the other housing. Of the coil 16 is not closely contacted with the coil bobbin 17 due to the vibration of the coil 16 due to the excitation of the coil 16, and a small displacement of the terminal does not occur. By avoiding this, disconnection can be prevented.

Further, the tapered portion 17 is formed on the coil bobbin 17.
m, when the stators A and B are pressed by the housings 11 and 12, the coil bobbin 1
7 are pressed in the radial direction in the housing, and the engaging projections 17 formed on the terminal mounting portion 17c are formed.
i engages with an engagement recess 12j formed in the housing 12, and the coil bobbin 17 is held in the housing 12.

[0076]

As described above, according to the present invention, by providing the boss portion and the engaging projection on the terminal mounting portion, one housing is pressed against the other housing, and the components constituting the stator are separated from each other. It is possible to prevent looseness at the coil bobbin and the terminal and disconnection at the winding terminal due to minute displacement.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of a stepping motor according to the present invention.

FIG. 2 is an explanatory diagram of a coil bobbin according to the present invention.

FIG. 3 is a view as viewed from C in FIG. 2;

FIG. 4 is an explanatory sectional view of a stepping motor according to the present invention.

FIG. 5 is a view as viewed in the direction D in FIG. 4;

FIG. 6 is an explanatory view showing another embodiment of the coil bobbin.

FIG. 7 is an explanatory diagram showing a winding method in a terminal.

FIG. 8 is an explanatory diagram showing a conventional example.

FIG. 9 is an explanatory diagram showing a conventional example.

FIG. 10 is an explanatory diagram showing a conventional example.

FIG. 11 is an explanatory diagram showing a conventional example.

[Explanation of symbols]

 11 Upper Housing 12 Lower Housing 13 Terminal 14 Concave Stator Core 15 Convex Stator Core 16 Coil 16a Winding 16b Winding End 17 Coil Bobbin 17c Terminal Attachment 17h Boss 17i Engagement Projection 17m Taper 18 Plate Housing 19 Rotor 20 Deceleration Device A Upper stator B Lower stator

Claims (2)

[Claims] 1. A laminated stepping motor in which a stator and a rotor are disposed between an upper housing and a lower housing, wherein the stator includes a coil bobbin on which a winding is wound, and a stator core having a convex magnetic pole. And at least two layers are positioned in the lower housing. The stator has a convex magnetic pole.
A plurality of coil bobbins and a convex stator core having a convex magnetic pole are laminated on the concave stator core, and each of the coil bobbins has a pair of mutually parallel annular side plates, and the side plates are coaxial. A cylindrical body portion to be connected is integrally formed, and one of the side plates is formed with a terminal mounting portion protruding radially outward, and the terminal mounting portion is formed when the respective stators are stacked. Each of the terminal mounting portions is provided with a boss portion extending in a direction opposite to the body portion in the axial direction, and each of the terminal mounting portions is provided on a non-adjacent side surface of each terminal mounting portion. An engaging projection is provided, and a tapered portion is formed on an adjacent side surface of each terminal mounting portion. The coil bobbin fixed structure of Gumota. 2. A coil bobbin fixing structure for a laminated stepping motor, wherein the tapered portion is formed on at least a part of an adjacent side surface.