JPH09172765A - Structure of stator of steeping motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To position respective stator members of both phases with the high precision in a circumferential direction and combine both the stators with a stable strength. SOLUTION: Engaging protrusions 10 and engaging recesses 13 are formed on the circumferential edge 9 of a first stator member 4 of which a first stator 2 consists and the recesses 13 and the protrusions 10 are formed on the circumferential edge 9 of a first stator member 4 of which a second stator 3 consists at positions corresponding to the protrusions 10 and the recesses 13 of the first stator member 4 of the first stator 2. Spreading recesses 11 are formed in the respective protrusions 10 and engaging recesses 12 which engage the engaging pieces 17 of a second stator members 5 are formed continuously with the spreading recesses 11. Engaging pieces 18 which are placed in the recesses 13 when the engaging pieces 17 are engaged with the recesses 12 are formed on the second stator members 5. When the engaging pieces 18 are pushed into the spreading recesses 11, the protrusions 10 are spread in the circumferential direction and the engaging pieces 18 are retained with the recesses 13 in the axial direction of a rotary shaft.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a PM (Permanent
Magnet) type stepping motor stator structure,
In particular, the present invention relates to a stator structure suitable for a claw pole type stepping motor.

[0002]

2. Description of the Related Art In a claw pole type stepping motor, a cup-shaped stator member formed by pressing a plate material for pressing and a plate-shaped stator member similarly formed by pressing are combined together and A one-phase stator that houses the exciting coil is formed inside. Then, two stators for one phase thus formed are combined to form the entire stator having two phases. At this time, in each phase, the relative positions in the circumferential direction are positioned so that the inductors of each stator member are equiangularly spaced. The relative positions in the circumferential direction are positioned so that the phases are shifted by only.

Conventionally, as a method of manufacturing such a stator, first, a plate-shaped stator member is united with a cup-shaped stator member to form a stator of each phase. A method of joining the thus-formed stators of the respective phases by spot welding, adhesion, or the like has been performed.

However, in such an assembling method,
Since relatively long welding time and bonding time are required, the assembly time becomes long and the manufacturing cost becomes high. Therefore, in order to shorten the assembling time, a stator structure has been proposed which enables assembling without welding or adhesion. For example, in the stepping motor disclosed in JP-A-56-38953,
As shown in FIG. 14, one cup-shaped stator member 4
The reverse taper-shaped engaging convex portion 42 provided on the peripheral end of the first stator member 43 is provided on the reverse taper-shaped engaging concave portion 44 provided at the position opposite to the engaging convex portion 42 on the peripheral end of the other stator member 43. By engaging them, both the stator members 41 and 43 are positioned in the circumferential direction and are locked and coupled in the rotation axis direction. Further, a locking piece 46 is provided on the peripheral end of the plate-shaped stator member 45.
And the locking piece 46 is used as the cup-shaped stator member 4
By engaging the engaging projections 42 or the engaging recesses 47 provided at positions different from the engaging recesses 44 at the peripheral ends of the stators 1, 43, each stator member 45 in the circumferential direction relative to each stator member 41, 43. They are united in the state of being positioned at.

In this stator structure, the engagement convex portion 42 formed in the reverse taper shape is forcibly fitted into the engagement concave portion 44 formed in the reverse taper shape in the rotation axis direction. That is, the engagement convex portion 42 and the engagement concave portion 4 are engaged with each other.
4 is accompanied by both plastic deformations. For this reason, it is unavoidable that the engaging convex portion 42 and the engaging concave portion 44 are not accurately positioned in the circumferential direction, or that the strength of the coupling in the rotational axis direction is insufficient.

[0006] The stator members 41, 43 of the stator of each phase
Is not coupled with an appropriate strength, the magnetic resistance between the stator members 41, 43 and 45 in the formed magnetic circuit of the stator becomes large, so that the efficiency of the stepping motor becomes lower than the design value. Further, when the stator members 41, 45 of the stators of the respective phases or the stators of the respective phases are not arranged at a predetermined relative position, the position between the inductor and the rotor of the stator members 41, 43, 45 Since the relationship becomes improper, motor characteristics such as one-step accuracy, torque, and response frequency deteriorate.

Further, in the stator structure proposed in Japanese Utility Model Laid-Open No. 5-84179, as shown in FIG. 15, the engaging protrusions 52 provided at the peripheral ends of one stator member 51 are used to form a stator for both phases. The stator 53 is circumferentially positioned by locking the member 53 in the circumferential direction and engaging the engaging convex portion 52 with the engaging concave portion 55 provided at the peripheral end of the other stator member 54. Further, an inverted V-shaped expanding portion 56 is provided at the tip of the engaging convex portion 52, while an inverse V-shaped protruding portion 57 is formed in the engaging concave portion 55. Then, the engaging convex portion 52 is engaged with the engaging concave portion 55, and the expanding portion 56 is pressed against the projecting portion 57 to expand in the circumferential direction, so that the engaging convex portion 52 with respect to the engaging concave portion 55. It is locked in the direction of the rotation axis. That is, when the engaging convex portion 52 engages with the engaging concave portion 55, the engaging convex portion 52 and the engaging concave portion 55 do not deform and engage as the expanding portion 56 is pressed by the protruding portion 57. Convex part 5
The distal end portion of the second member 2 is expanded in the circumferential direction so as to be locked in the engagement concave portion 55 in a state where it is not deformed.

Therefore, according to this stator structure, since the engaging projections 52 and the engaging recesses 55 are not deformed at the time of engagement, the engaging projections 52 can be circumferentially oriented with high accuracy with respect to the engaging recesses 55. Be positioned at. Then, as the engaging convex portion 52 engages with the engaging concave portion 55, the tip end portion expands and is locked in the undeformed engaging concave portion 55 in the rotation axis direction. And the engagement recess 55 is coupled with a stable strength.

[0009]

However, in the stator structure disclosed in Japanese Utility Model Laid-Open No. 5-084179, the two stator members 53 and 54 are connected to each other.
It is connected with sandwiching. Since the plate thickness of the stator member 53 formed by pressing is relatively inaccurate, the distance between the peripheral ends of the stator members 51 and 54 will vary. As a result, the length of engagement of the engaging projection 52 with the engaging recess 55 varies, so that the amount of deformation of the expanding portion 56 varies. Therefore, the engaging convex portion 52 and the engaging concave portion 5
Since the strength of the connection with the stator 5 varies, the stator members 51,
The strength of the bond between 54 becomes unstable.

The present invention has been made in order to solve the above problems, and an object thereof is to position each stator member of both phases with high accuracy in the circumferential direction and to fix both stators. It is an object of the present invention to provide a stator structure of a stepping motor that can be coupled with stable strength.

[0011]

In order to solve the above problems, the invention according to claim 1 comprises a first stator member formed in a cup shape and a second stator member formed in a plate shape. A first stator, and a second stator including a first stator member and a second stator member that are similarly formed. One first stator member is provided with an engaging protrusion, and the other first stator member is provided. Is provided with an engaging recess for engaging the engaging convex portion and positioning in the circumferential direction, and an expanding concave portion capable of expanding the engaging convex portion in the circumferential direction is provided on the tip end side of the engaging convex portion. The engaging recess is provided with an expanding portion that fits in the expanding recess to expand the engaging protrusion on both sides in the circumferential direction, and the engaging protrusion engages with the engaging recess to expand. By fitting the opening into the expanding recess, the engaging protrusion and the engaging recess are locked in the rotation axis direction. In the stator structure of the stepping motor, the engaging convex portion and the engaging concave portion are engaged in a state where the peripheral end of one first stator member and the peripheral end of the other first stator member are in contact with each other. A locking piece extending in the radial direction is provided at the peripheral end of each second stator member, and a first locking that locks the locking piece in the circumferential direction at the peripheral end of each first stator member. A recess was provided.

According to a second aspect of the present invention, in the first aspect of the present invention, the second stator member, which constitutes one stator together with the first stator member provided with the engagement recess, is formed. The locking piece is the expanding portion provided in the engaging concave portion of the first stator member, and the first locking concave portion formed in the first stator member having the engaging convex portion is the same. The expansion concave portion is provided on the engaging convex portion of the stator member.

According to a third aspect of the present invention, in the invention according to the second aspect, the first stator member provided with the engaging projection is provided with a base end side of the expanding recess. A second locking recess for circumferentially locking the locking piece formed on the second stator member that constitutes the stator together with the first stator member is formed continuously with the expansion recess.

According to a fourth aspect of the present invention, in the invention according to any one of the first to third aspects, the engaging recess and the peripheral end of the first stator member are formed with the engaging recess. When the engaging convex portion engages with the engaging concave portion, each boundary portion is brought into the engaging concave portion by the engaging convex portion, and the engaging convex portion within the engaging concave portion. Each of the protrusions is provided so as to lock in the direction of the rotation axis.

Therefore, according to the invention described in claim 1,
When the engagement protrusion of one first stator member engages with the engagement recess of the other first stator member, both stators are positioned in the circumferential direction. Further, when the engaging convex portion engages with the engaging concave portion, the expanding portion fits into the expanding concave portion, the engaging convex portion expands in the circumferential direction, and is engaged with the engaging concave portion in the rotation axis direction. Both stators are connected in the direction of the rotation axis because they are stopped. At this time, each second stator member is locked in the circumferential direction by locking the locking piece extending in the radial direction in the first locking recess provided at the peripheral end of the first stator member. The engaging protrusion engages with the engaging recess in a state where the peripheral ends of both the first stator members are in contact with each other, so that the length of the engaging protrusion engaging with the engaging recess is equal to the length of the second stator member. The thickness variation does not affect. As a result, the strength of the connection between the engagement protrusion and the engagement recess is stable.

According to the invention described in claim 2, according to claim 1
In addition to the operation of the invention described in (1), a second stator that constitutes one stator together with a first stator member provided with an engagement recess is provided.
The locking piece of the stator member is circumferentially locked by the expansion concave portion of the engaging convex portion of the first stator member that constitutes the other stator, and the expansion concave portion is also fixed to the locking piece. Is expanded in the circumferential direction. At this time, since the locking piece is formed as a separate member from the first stator member in which the engaging recess is formed, it slightly moves in the circumferential direction so as to fit comfortably into the expanding recess. For this reason, the engaging convex portion is always spread evenly in both circumferential directions. As a result, the strength of the connection between the engagement protrusion and the engagement recess is further stabilized.

According to the invention of claim 3, claim 2
In addition to the effect of the invention described in (1), both the second stator members are engaged with the engaging projections of one of the first stator members and locked in the circumferential direction, so that both the second stator members have high accuracy. Positioned in the circumferential direction.

According to the invention of claim 4, according to claim 1,
In addition to the effect of the invention according to any one of claims 3 to 4, the engaging protrusions engaged in the engaging recesses are locking pieces brought into the engaging recesses by the engaging protrusions. It is locked in the direction of the rotation axis. As a result, even if the sizes of the engaging concave portion and the engaging convex portion vary, each locking piece fills the gap between the engaging concave portion and the engaging convex portion, so that the engaging concave portion and the engaging convex portion are separated from each other. Combined with stable strength.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION

[First Embodiment] A first embodiment of the present invention will be described below with reference to FIGS.

As shown in FIG. 1, the stepping motor 1 of the present embodiment is a claw pole type stepping motor having two phases. That is, the stepping motor 1 is
A first stator 2 and a second stator 3 forming each phase,
It is composed of a rotor (not shown) that is excited by each of the stators 2 and 3.

As shown in FIG. 3, the first stator 2 is formed by pressing a plate material for pressing into a cup shape, and a first stator member 4 is also formed by pressing a plate material for pressing into a plate shape. The second stator member 5 is formed.

The first stator member 4 is provided with a disk-shaped side magnetic path plate 6, and a plurality of inductors 7 are formed at the inner peripheral end of the side magnetic path plate 6 so as to extend in the rotation axis direction. ing. A cylindrical outer peripheral magnetic path portion 8 is formed at the outer peripheral end of the side magnetic path plate 6. An annular exciting coil (not shown) is housed between each inductor 7 and the outer peripheral magnetic path portion 8, and a rotor is housed in the central portion surrounded by each inductor 7.

As shown in FIG. 4, the first stator member 4 is provided with engaging protrusions 10 at the peripheral ends 9 of the outer peripheral magnetic path portion 8 at positions facing each other with the axis of rotation interposed therebetween. ing. As shown in FIG. 2A, the engagement protrusion 10 is
It is formed so as to extend in the rotation axis direction from the peripheral end 9. At the center of the engaging projection 10 in the circumferential direction, on the front end side of the peripheral end 9, there is provided an expanding recess 11 as a first locking recess that can evenly expand the engaging projection 10 in the circumferential direction. Has been formed. Further, on the base end side of the engagement protrusion 10 with respect to the peripheral end 9,
A locking recess 12 as a second locking recess that is continuous with the expanding recess 11 is formed.

Further, in the first stator member 4, at the peripheral end 9 of the outer peripheral magnetic path portion 8, the engaging convex portions 10 to 9 are formed.
Engagement recesses 13 are formed at positions moved by 0 °. As shown in FIG. 2A, the engagement recess 13 is formed so as to extend from the peripheral end 9 in the rotational axis direction, and is formed on both sides of the base end thereof (that is, on the opposite side of the peripheral end 9 side) in the peripheral direction. Each of the extending locking portions 14 is formed.

As shown in FIG. 5, the second stator member 5 is provided with a disk-shaped side magnetic path plate 15, and a plurality of inductors 16 are formed at the inner peripheral end thereof so as to extend in the rotation axis direction. Has been done.

On the outer peripheral end of the side magnetic path plate 15 of the second stator member 5, engaging pieces 17 that radially protrude are formed at positions facing each other with the axis of rotation interposed therebetween. The respective positions correspond to the first stator member 4 and the second stator member 4.
With the stator member 5 positioned in the circumferential direction,
The engagement pieces 17 are located at positions facing the engagement protrusions 10. As shown in FIG. 2A, each engagement piece 17
Is formed into a shape that engages with each locking recess 12.

In the second stator member 5, the engaging pieces 17 to 90 are provided at the outer peripheral end of the side magnetic path plate 15.
Locking pieces 18 that project in the radial direction are formed as expanded portions at the positions that have moved. Each of these positions is a position where each locking piece 18 opposes the center of each engagement recess 13 in a state where the first stator member 4 and the second stator member 5 are circumferentially positioned. There is. FIG.
As shown in (a), each locking piece 18 is provided with tapered surfaces 18a on both sides thereof, and the engaging projections 10 can be expanded in the circumferential direction by being fitted into the expanding recesses 11 by the tapered surfaces 18a. Is formed in.

On the other hand, as shown in FIG. 3, the second stator 3 has a first stator member 4 having substantially the same structure as the first stator member 4.
It is composed of a stator member 4 and a second stator member 5 having substantially the same structure as the second stator member 5. Therefore, the first stator member 4 and the second stator member 5 will be described below with the same reference numerals as those of the first stator member 4 and the second stator member 5.

The first stator member 4 includes the first stator 2
With the second stator 3 and the second stator 3 positioned in the circumferential direction,
Each engaging convex portion 1 of the first stator member 4 on the first stator 2 side
Engagement recesses 13 are formed at positions where 0s face each other. Similarly, the engaging protrusions 1 are provided at positions where the engaging recesses 13 of the first stator member 4 on the first stator 2 side face each other.
0 is formed.

The engaging projections 10 and the engaging recesses 13 facing each other are engaged with each other when the peripheral ends 9 of the first stator members 4 are in contact with each other. At this time, each engagement protrusion 10 is engaged with the engagement recess 17 by the engagement piece 17.
Is engaged with the engaging recessed portion 13. Further, the locking piece 18 arranged in the engaging recess 13
Engages with the expanding concave portion 11 of the engaging convex portion 10 in a state in which the engaging piece 17 is engaged with the locking concave portion 12, so that the engaging convex portion 10 can be expanded in the circumferential direction. .

Next, the operation of the stator structure of the stepping motor configured as above will be described. In order to assemble the stators 2 and 3, first, the engagement pieces 17 of the one second stator member 5 are fitted into the locking recesses 12 of the first stator member 4 of the first stator 2. As a result,
The second stator member 5 is joined to the first stator member 4 while being positioned in the circumferential direction. At this time, the second
Each locking piece 18 of the stator member 5 is formed by the first stator member 4
The engaging recesses 13 are arranged substantially at the center in the circumferential direction.

Similarly, the engaging pieces 17 of the other second stator member 5 are fitted into the engaging recesses 12 of the first stator member 4 of the second stator 3. As a result, the second stator member 5 is joined to the first stator member 4 while being positioned in the circumferential direction. At this time, each locking piece 18 of the second stator member 5 is arranged at the center in the circumferential direction of each engaging recess 13 of the first stator member 4.

Next, each engaging projection 10 on the first stator 2 side
To the engaging recesses 13 on the second stator 3 side, and the engaging protrusions 10 on the second stator 3 side to the engaging recesses 13 on the first stator 2 side. In this state, when the stators 2 and 3 are pressed in the rotation axis direction so as to approach each other, the locking pieces disposed in the engaging recesses 13 in the expanding recesses 11 of the engaging protrusions 10 face each other. 18 is press-fitted. Along with this, the engaging protrusions 10 are provided on both sides of the engaging recesses 1
In the state of being regulated by 3, the taper surfaces 18a are expanded and deformed in the circumferential direction. Due to this deformation, the engagement concave portion 13 is hardly deformed, so that the engagement convex portion 10 and the engagement piece 1 are not deformed.
It is press-fitted between 8 and. As a result, since the engagement protrusion 10 is supported in the circumferential direction with respect to the engagement recess 13, both stators 2 and 3 are positioned in the circumferential direction.

Further, a part of the tip of the engaging projection 10 deformed by engaging the engaging projection 10 with the engaging recess 13 enters each locking portion 14, so that the engaging projection 10 Are coupled to the engaging recess 13 in the rotation axis direction. As a result, the two stators 2 and 3 are connected in the direction of the rotation axis. At this time, the two stators 2 and 3 are coupled in a state where the peripheral ends 9 of the first stators 4 are in contact with each other. Therefore, each engaging recess 1
The length in the rotation axis direction of the engaging projection 10 that engages with 3 is irrelevant to the thickness of the second stator member 5. Therefore, the lengths of the engagement protrusions 10 that engage with the engagement recesses 13 do not vary, and the strength of engagement between the engagement recesses 13 and the engagement protrusions 10 is stable.

Further, when the locking piece 18 is press-fitted into the expanding recess 11, the locking piece 18 is not accurately arranged in the center of the engaging recess 13 due to the dimensional variation of the stator members 4 and 5. However, since the locking piece 18 is formed as a separate member from the engaging recess 13, it slightly moves in the circumferential direction so as to engage with the expanding recess 11 without difficulty. As a result, the engaging protrusion 10
Since it always spreads evenly on both sides in the circumferential direction, the engagement strength does not vary due to dimensional variation.

Further, each engaging convex portion 1 of each first stator member 4
0 because both second stator members 5 are engaged, the second
The stator members 5 are positioned with high accuracy in the circumferential direction. Moreover, the engagement protrusions 10 are formed on both the first stator members 4, and the second protrusions 10 are formed on the engagement protrusions 10.
Since the stator members 5 are engaged, each first stator member 4 is positioned with high accuracy in the circumferential direction with respect to both the second stator members 5.

As described above in detail, according to the stator structure of the stepping motor of the present embodiment, the following effects can be obtained. (A) The engaging protrusions 10 of one first stator member 4 engage with the engaging recesses 13 of the other first stator member 4 in a state where the peripheral ends 9 of both first stator members 4 are in contact with each other. To do.
At this time, as the engaging convex portion 10 engages with the engaging concave portion 13, the locking piece 18 fits into the expanding concave portion 11 and the engaging convex portion 1
Expand 0 in the circumferential direction. Then, the engaging projection 10 is locked to the engaging recess 13 in the rotation axis direction by expanding the engaging projection 10 in the circumferential direction. As a result, the engaging recess 13 is not deformed at the time of engagement, so that the engaging protrusion 10 is positioned with respect to the engaging recess 13 in the circumferential direction with high accuracy. or,
Since the second stator member 5 is not sandwiched between the peripheral ends 9 of both the first stator members 4, the engaging protrusions 1 that engage with the engaging recesses 13 are formed.
The length of 0 in the rotation axis direction is not affected by the variation in the thickness of the second stator member 5. As a result, the engagement protrusion 10 is coupled to the engagement recess 13 with stable strength,
Both stators 2 and 3 are coupled with stable strength. Therefore, both the stators 2 and 3 can be positioned in the circumferential direction with high accuracy and can be coupled with a stable strength in the rotation axis direction, so that stable efficiency and various characteristics of the stepping motor 1 can be obtained. it can.

(B) Spreading concave portion 11 of each engaging convex portion 10
Is expanded by the locking piece 18 of the second stator 5 which is a member different from the first stator member 4 in which the engagement recess 13 is formed. Therefore, even if the locking piece 18 is not accurately arranged at the center of the engagement recess 13 due to the dimensional variation of the stator members 4 and 5, the locking piece 18 can be reasonably engaged with the expansion recess 11. 18 moves in the circumferential direction. as a result,
Since the engaging protrusions 10 are always spread evenly on both sides in the circumferential direction, variations in the coupling strength of the engaging protrusions 10 with the engaging recesses 13 due to dimensional variations are suppressed. Therefore, both stators 2 and 3 can be coupled with more stable strength, and thus more stable efficiency of the stepping motor 1 can be obtained.

(C) Since both second stator members 5 are circumferentially locked together on the same engaging projection 10 of the first stator member 4, both second stator members 5 are circumferentially aligned with high accuracy. Be positioned at. Therefore, more stable motor characteristics can be obtained.

(D) Engagement protrusions 10 are formed on the respective first stator members 4, and the second protrusions 10 are formed on the engagement protrusions 10.
Since the stator members 5 are locked, each first stator member 4 is positioned in the circumferential direction with high accuracy with respect to both the second stator members 5. Therefore, more stable motor characteristics can be obtained.

[Second Embodiment] Next, a second embodiment of the present invention will be described with reference to FIGS. In addition, in the present embodiment, as shown in FIG.
The engaging convex portion 10 and the engaging concave portion 13 of the embodiment
The only change is the shape of the
This embodiment is different from the embodiment. Therefore, the same components as those in the first embodiment are designated by the same reference numerals, and the description thereof will be omitted. Only the engagement protrusion 10 and the engagement recess 13 will be described in detail.

As shown in FIG. 8, the first stator member 4 is provided with engaging protrusions 10 at the peripheral ends of the outer peripheral magnetic path portion 8 at positions facing each other with the axis of rotation interposed therebetween. There is. As shown in FIG. 7A, the engagement protrusion 10 is formed so as to extend from the peripheral end 9 in the rotation axis direction, and the engagement protrusion 10 is located at the center of the periphery in a direction closer to the tip than the peripheral end 9. Expansion recess 1 capable of uniformly expanding the tip of the part 10 in the circumferential direction
1 is formed. The engaging convex portion 10 of this embodiment is not provided with the engaging concave portion 12 of the first embodiment.

A pair of engaging recesses 13 is formed in the first stator member 4. As shown in FIG.
The engagement recess 13 is formed so as to extend from the peripheral end 9 in the direction of the rotation axis, and is formed in a shape that expands in a taper shape from the peripheral end 9 side toward the base end side.

As shown in FIG. 9, only a pair of locking pieces 18 are formed on the outer peripheral end of the second stator member 5.
Similarly, the first stator member 4 of the second stator 3 is formed with a pair of engaging concave portions 13 and a pair of engaging convex portions 10, and the second stator member 5 is formed with a pair of locking pieces 18. There is. Each locking piece 18 has a tapered surface 18a on both sides thereof.
It has.

The engaging projections 10 and the engaging recesses 13 facing each other between the first stator 2 and the second stator 3 are in contact with each other at the peripheral ends 9 of the first stator members 4. It is adapted to be engaged in the state. The locking pieces 18 arranged in each of the engaging recesses 13 are the recesses 11 for expanding the engaging protrusions 10.
The engaging projection 10 can be expanded in the circumferential direction by engaging with the.

Next, the operation of the stator structure of the stepping motor configured as above will be described. First, the second stator member 5 is assembled with the first stator member 4 of each of the stators 2 and 3 while being positioned in the circumferential direction. As a result, each locking piece 18 of each second stator member 5 is arranged substantially at the center in the circumferential direction of each engagement recess 13 of the associated first stator member 4.

Next, each engaging projection 10 on the first stator 2 side
To the engaging recesses 13 on the second stator 3 side, and the engaging protrusions 10 on the second stator 3 side to the engaging recesses 13 on the first stator 2 side. In this state, when the stators 2 and 3 are pressed in the rotation axis direction so as to approach each other, the locking pieces 18 that face each other are press-fitted into the expansion recesses 11 of the engagement protrusions 10. Along with this, the engaging convex portion 10 is expanded and deformed in the circumferential direction, and the engaging convex portion 10 includes the engaging concave portion 13 and the locking piece 18 with almost no deformation of the engaging concave portion 13. Is pressed in between. As a result,
Since the engaging convex portion 10 is supported in the circumferential direction with respect to the engaging concave portion 13, both the stators 2 and 3 are positioned in the circumferential direction.

Further, since the engaging convex portion 10 expands in a tapered shape in accordance with the engaging concave portion 13 having the inverse taper shape, the engaging convex portion 10
And the engaging recess 13 are coupled to each other in the rotation axis direction. At this time, since the stators 2 and 3 are coupled in a state in which the peripheral ends 9 are in contact with each other, the coupling strength between the engagement protrusion 10 and the engagement recess 13 is stable.

Further, when the locking pieces 18 are fitted into the respective expansion recesses 11, the locking pieces 18 are slightly moved in the circumferential direction so as to be naturally engaged with the expansion recesses 11, so that the engagement projections are formed. Part 10
Always spread evenly on both sides in the circumferential direction.

As described in detail above, the effects described in (a) and (b) in the first embodiment can be obtained also by the stator structure of the stepping motor of the present embodiment.

[Third Embodiment] Next, a third embodiment of the present invention will be described with reference to FIGS. The present embodiment differs from the first embodiment only in that the shapes of the engaging projection 10 and the engaging recess 13 are changed and the projecting piece 19 is further provided in the first embodiment. different. Therefore, the same components as those in the first embodiment are designated by the same reference numerals, and the description thereof will be omitted. Only the engagement protrusion 10 and the engagement recess 13 will be described in detail.

As shown in FIG. 10, the engaging convex portion 10 is formed so as to extend from the peripheral end 9 in the direction of the rotation axis, and both sides are formed in a taper shape which expands outward from the peripheral end 9. . At the center of the engaging projection 10 in the circumferential direction, the circumferential end 9
On the front end side, there is formed an expanding recess 11 capable of expanding the end of the engaging projection 10 evenly in the circumferential direction. Further, a locking recess 12 continuous with the expanding recess 11 is formed on the base end side of the engaging projection 10 with respect to the peripheral end 9.

Similarly, as shown in FIG. 10, the engaging recess 13
Is formed in a tapered shape that widens from the peripheral end 9 toward the base end side. The circumferential length of the engaging concave portion 13 on the circumferential end 9 side is formed to be larger than the circumferential length of the engaging convex portion 10 on the tip end side. Therefore, in this engaging recess 13,
The engaging convex portion 10 can be engaged in the rotation axis direction.

Further, at each boundary between the open end of the engaging recess 13 and the peripheral end 9, projection pieces 19 extending outward from the peripheral end 9 and extending toward each other are formed. . When the engaging protrusion 10 is engaged with the engaging recess 13 in the rotation axis direction, the protrusions 19 are brought into the engaging recess 13 by the engaging protrusion 10 and the engaging recess 13 inside the engaging recess 13. The engaging projection 10 is locked in the direction of the rotation axis.

The operation of the stator structure of the stepping motor configured as above will be described. The tip end of each engagement protrusion 10 on the first stator side is made to face each engagement recess 13 on the second stator side, and each engagement protrusion 10 on the second stator side is engaged with each engagement member on the first stator side. It is made to face the fitting recess 13. In this state, when the two stators are pressed in the direction of the rotation axis so as to approach each other, the tips of the engaging protrusions 10 deform the protruding pieces 19 and bring them into the engaging recesses 13 while engaging the engaging recesses 13. Engage. At the same time, the locking piece 18 is press-fitted into the expanding concave portion 11 of the engaging convex portion 10 to expand the engaging convex portion 10 in the circumferential direction. As a result, the engagement protrusion 10 is locked to the engagement recess 13 in the circumferential direction and the rotation axis direction.

At this time, the deformed projection pieces 19 are inserted between the circumferential sides of the engaging projection 10 and the circumferential sides of the engaging recess 13, respectively. Even when the size of 13 varies and a gap is formed between the two, the gap is filled with each protrusion piece 19. Therefore, the engaging convex portion 10 and the engaging concave portion 13 are coupled with stable strength.

As described in detail above, according to the stator structure of the stepping motor of the present embodiment, the following effects can be obtained in addition to the effects (a) to (d) of the first embodiment. it can.

(A) The projection piece 19 provided at the opening end of the engagement recess 13 is brought into the engagement recess 13 by the engagement projection 10 at the time of engagement so that the engagement projection 10 is located on both sides of the engagement recess 13. The projection pieces 19 are engaged with each other in a biting state. As a result, due to variations in component dimensions, the engaging protrusion 1
Even when the size of 0 is smaller than the size of the engaging concave portion 13, both gaps are filled with the respective projecting pieces 19, so that the engaging convex portion 10 and the engaging concave portion 13 are stable. Combined in strength.

It should be noted that the present invention is not limited to the above-described embodiment, but may be configured as follows. (1) In each of the first to third embodiments, instead of the locking piece 18 of the second stator member 5, a protrusion integrally provided on the first stator member 4 at the central position of the engaging recess 13. May be used as the expansion portion. In this case, the peripheral edge 9 of the first stator member 4 is provided with a first locking concave portion for locking the locking piece 18 at a position other than the position where the engaging concave portion 13 and the engaging convex portion 10 are formed. . Also with this configuration, both stators 2 and 3 can be positioned in the circumferential direction with high accuracy, and both stators 2 and 3 can be coupled with stable strength.

(2) In the first or third embodiment, the engaging projection 10 is provided only on one of the first stator members 4, and only the engaging recess 13 is provided on the other first stator member 4. The configuration may be different. With this configuration as well, the effects (a) to (c) in the first embodiment can be obtained.

(3) The shape of the engaging projection 10 is not limited to the above-mentioned shapes, and for example, as shown in FIG.
2 and the expansion recess 11 may be formed in a tapered shape. In this configuration, the second stator member 5 and the first stator member 5
Since each locking piece 18 engages with the locking recess 12 along the tapered surface when the stator member 4 is coupled, the locking piece 18
The galling between and the engaging convex portion 10 is eliminated. As a result, the engagement protrusion 10 and the locking piece 18 are prevented from being damaged, so that the first stator member 4 and the second stator member 5 can be positioned with high accuracy.

(4) The locking pieces 18 are tapered on both sides.
Although it is formed in a tapered shape having a, it may be formed in another shape, for example, a semi-cylindrical shape. (5) The protrusion piece 19 provided in the engagement recess 13 may be formed with a larger volume than the protrusion piece 19, as shown in FIG. In this case, even if the gap between the engagement concave portion 13 and the engagement convex portion 10 becomes large, the coupling can be performed with stable strength.

(6) The number of connecting portions formed by the engaging projections 10 and the engaging recesses 13 provided between the stators 2 and 3 is not limited to four. At this time, the number of the engaging projections 10 or the number of the engaging recesses 13 provided on one of the first stator members 4 is not limited to two, and may be one or three or more.

(7) The engaging portion formed by the engaging convex portion 10 and the engaging concave portion 13 may be provided at a position that is not equiangularly spaced with respect to the rotation axis. The technical ideas other than the claims that can be grasped from the embodiment will be described below together with their effects.

(1) In the stator structure for a stepping motor according to a third aspect, the engaging protrusions 10 are provided on the first stator members 4 of the stators 2 and 3, respectively. According to such a configuration, both second stator members 5 are positioned in the circumferential direction with high accuracy, and both second stator members 5 are positioned.
On the other hand, since each first stator member 4 is positioned in the circumferential direction with high accuracy, each stator member 4, 5 is positioned in the circumferential direction with high accuracy.

[0066]

As described above in detail, according to the first aspect of the invention, the stator members of both phases can be positioned in the circumferential direction with high accuracy, and the strength of both stators is stable. Can be combined with. Therefore, stable motor efficiency and various characteristics can be obtained.

According to the invention described in claim 2, according to claim 1
In addition to the effect of the invention described in (1), since both stators can be coupled with more stable strength, more stable motor efficiency can be obtained.

According to the invention of claim 3, according to claim 2,
In addition to the effect of the invention described in (1), since the second stator members are positioned with high accuracy in the circumferential direction, more stable motor characteristics can be obtained.

According to the invention of claim 4, according to claim 1,
In addition to the effect of the invention according to any one of claims 3 to 3, even if the size of each stator member varies, both stators can be coupled with a stable strength, and therefore stable regardless of the size variation. It is possible to obtain various motor characteristics.

[Brief description of the drawings]

FIG. 1 is a front view showing a stepping motor according to a first embodiment.

2A is a front view of an engagement protrusion and an engagement recess before engagement, and FIG. 2B is a front view of an engagement protrusion and an engagement recess after engagement.

FIG. 3 is an exploded perspective view showing a configuration of a stator.

FIG. 4 is a front view of a first stator member.

FIG. 5 is a front view of a second stator member.

FIG. 6 is a front view of a stepping motor according to a second embodiment.

FIG. 7A is a front view of an engagement protrusion and an engagement recess before engagement, and FIG. 7B is a front view of an engagement protrusion and an engagement recess after engagement.

FIG. 8 is a front view of the first stator.

FIG. 9 is a front view of a second stator.

FIG. 10 is a front view of an engagement protrusion and an engagement recess before engagement according to the third embodiment.

FIG. 11 is a front view of the engagement protrusion and the engagement recess after engagement.

FIG. 12 is a front view of an engagement recess of another example.

FIG. 13 is a front view of the engaging recess.

FIG. 14 is a front view showing a stator structure of a conventional stepping motor.

FIG. 15 is a perspective view showing a stator structure of another stepping motor.

[Explanation of symbols]

2 ... First stator, 3 ... Second stator, 4 ... First stator member, 5 ... Second stator member, 9 ... Peripheral end, 10 ... Engaging protrusion, 11 ... For expanding as first engaging recess Recess, 12 ...
Locking recess as second locking recess, 13 ... Engaging recess, 17
... engaging piece, 18 ... locking piece as an expanding portion, 19 ... projecting piece.

Claims (4)

[Claims] 1. A first stator comprising a cup-shaped first stator member and a plate-shaped second stator member, and a first stator member and a second stator which are similarly formed.
A second stator including a stator member, one first stator member is provided with an engaging protrusion, and the other first stator member is engaged with the engaging protrusion to position in the circumferential direction. An engaging concave portion is provided, and an expanding concave portion capable of expanding the engaging convex portion in the circumferential direction is provided on the tip end side of the engaging convex portion, and the engaging concave portion is fitted into the expanding concave portion. By providing an expanding portion that expands the engaging convex portion on both sides in the circumferential direction, the engaging convex portion is engaged with the engaging concave portion, and the expanding portion is fitted into the expanding concave portion, thereby forming the engaging convex portion. In a stator structure of a stepping motor in which an engaging concave portion is locked in the rotation axis direction, the engaging convex portion and the engaging concave portion are a peripheral end of one first stator member and the other first stator. Engage in a state of abutting the peripheral edge of the member, and extend radially in the peripheral edge of each second stator member. That the locking piece is provided, each on a peripheral edge of the first stator member, the stator structure of the stepping motor provided with a first locking recess for locking the locking pieces in the circumferential direction. 2. The engaging piece formed on the second stator member that constitutes one stator together with the first stator member having the engaging recess is provided in the engaging recess of the first stator member. And the first locking recess formed in the first stator member provided with the engagement protrusion, and the expansion recess provided in the engagement protrusion of the first stator member. The stator structure for a stepping motor according to claim 1. 3. The first stator member provided with the engaging projection is provided with a first stator member at a base end side of the expanding recess.
A second device for circumferentially locking the locking piece formed on the second stator member that constitutes a stator together with the stator member.
The stator structure of the stepping motor according to claim 2, wherein the locking recess is formed continuously with the expanding recess. 4. The engaging projection is provided at each boundary between the engaging recess and the peripheral end of the first stator member where the engaging recess is formed, when the engaging projection engages with the engaging recess. Any one of claims 1 to 3, wherein projections that are brought into the engagement recess by the engagement projection and that lock the engagement projection in the rotation axis direction are provided in the engagement recess. The stator structure of the stepping motor according to claim 1.