JP2003185765A - Stepping motor and electronic timepiece - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To rotate a rotor with small energy without deteriorating the basic characteristics of a stepping motor. <P>SOLUTION: Saturable parts 112 and 113 are magnetically saturated with the magnetic flux of the rotor 102 and held at high magnetic resistance, and areas 117 and 116 composed of the saturable parts 112 and 113 and positioning through holes 105 and 104 form a positioning part. When alternating signals are supplied to a coil 109 to produce magnetic flux in a stator 101, the saturable parts 110 and 111 are first saturated and attain high magnetic resistance, after which the rotor 102 is rotated 180 degrees at a time in the direction of the arrow B by the interaction of magnetic poles produced in the stator 101 and the magnetic poles of the rotor 102. <P>COPYRIGHT: (C)2003,JPO

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 an electronic timepiece using the stepping motor.

[0002]

2. Description of the Related Art Conventionally, a stator having a through hole for accommodating a rotor and a positioning portion for determining a stop position of the rotor,
The rotor is provided in the rotor housing through hole, and the coil is provided. The rotor is rotated by supplying an alternating signal to the coil to generate magnetic flux in the stator, and at the same time, to the positioning portion. A stepping motor that stops the rotor at a corresponding position is used.

FIG. 3 is a block diagram of a stepping motor conventionally used in an electronic timepiece. In FIG.
The stepping motor is integrated with a stator 301 having a rotor accommodating through hole 303, a rotor 302 rotatably accommodated in the rotor accommodating through hole 303 and magnetized into two poles (S pole and N pole), and the stator 301. The magnetic core 308 and the coil 309 wound around the magnetic core 308 are provided.

The stator 301 is provided with two recesses (outer notches) at positions facing each other with the rotor accommodating through hole 303 interposed therebetween.
306, 307 are provided and outer notches 306, 3
07 and the rotor accommodating through hole 303 between the saturable portion 31.
0 and 311 are formed. Further, the stator 301 is provided with two positioning recesses (inner notches) 304 and 305 which are continuous with the rotor housing through-hole 303 and are opposed to each other with the rotor housing through-hole 303 interposed therebetween. When the coil 309 is not excited, the rotor 302 is stably stopped at a position where the axis A is orthogonal to the line segment connecting the inner notches 304 and 305.

Now, a rectangular wave pulse signal is sent to the coil 309.
When the electric current i is supplied to the stator 301 in the arrow direction of FIG. 3, a magnetic flux is generated in the stator 301 in the arrow C direction. As a result, the saturable portions 310 and 311 are saturated first to have a high magnetic resistance, and thereafter, the interaction between the magnetic poles of the stator 301 and the magnetic poles of the rotor 302 causes the rotor 302 to move in the direction of arrow B in FIG. It rotates and stops stably.

Next, when a pulse signal having a rectangular wave of opposite polarity is supplied to the coil 309 and a current flows in the direction opposite to the arrow in FIG. 3, magnetic flux is generated in the stator 301 in the direction opposite to the arrow C. As a result, the saturable portions 310 and 311 are saturated first to have a high magnetic resistance, and thereafter, the interaction between the magnetic poles of the stator 301 and the magnetic poles of the rotor 302 causes the rotor 302 to move in the direction of arrow B in FIG. It rotates and stops stably. After that, by supplying signals having different polarities (alternating signals) to the coil 309 in this manner, the above-described operation is repeated, and the rotor 302 is rotated 18 times.
It can be continuously rotated in the direction of arrow B by 0 degree.

[0007]

By the way, the stable rotation of the stepping motor is ensured by the inner notch 3 formed continuously in the rotor accommodating through hole 303 of the stator 301.
The magnetic potential difference is generated by 04 and 305,
The rotor 302 is located at a position corresponding to the inner notches 304 and 305.
Is stable and stationary. In recent years, as the life of electronic timepieces has been extended, the rotor 302 is required to consume less energy
The need to rotate is emerging. for that purpose,
The magnetic potential difference is as small as possible and high accuracy is required. In order to generate a minute magnetic potential energy difference, the inner notches 304 and 305 are minimized, or the rotor 302 and the rotor housing through hole 30 are formed.
It is conceivable to increase the gap between the three.

However, the rotor accommodating through-hole 303
The inner notches 304 and 305 are formed by pressing. Through hole 303 for housing rotor and inner notch 30
When forming Nos. 4 and 305 by press working, in order to simplify the shape of the press die and prolong the service life, the first step of forming the perfect circular rotor accommodating through hole 303 and the rotor accommodating through hole It is divided into a second step of forming inner notches 304 and 305 continuously with 303. Inner notch 30
The shape error of Nos. 4 and 305 is a factor that greatly affects the accuracy of the static torque value of the rotor 302, and high accuracy is required to bring the static torque to a predetermined value. Small inner notches 3 at consecutive positions
Forming 04 and 305 has a problem in that it is difficult to manufacture.

On the other hand, in the method of increasing the gap between the rotor 302 and the rotor accommodating through hole 303, such a difficulty does not occur, but the rotor 302 and the rotor accommodating through hole 303.
If the gap is increased, the magnetic loss is increased. Therefore, there is a problem in that the efficiency of the stepping motor is reduced, which leads to deterioration of basic characteristics such as an increase in current consumption of the stepping motor and a reduction in output.

The present invention has been made in view of the above problems, and an object thereof is to make it possible to rotate a rotor with a small amount of energy without deteriorating the basic characteristics of a stepping motor. Another object of the present invention is to provide an electronic timepiece that can be driven with a small amount of energy.

[0011]

According to the present invention, a stator having a through hole for accommodating a rotor and a positioning portion for determining a stop position of the rotor, a rotor arranged in the through hole for accommodating the rotor, and a coil. And a stepping motor configured to stop the rotor at a position corresponding to the positioning portion while rotating the rotor by supplying an alternating signal to the coil to generate magnetic flux in the stator, The positioning portion has a plurality of positioning through holes formed in the stator so as to form a first saturable portion having a first predetermined length from an end portion of the rotor housing through hole, A stepping motor is provided, wherein the first saturable portion is magnetically saturated by the magnetic flux of the rotor. The first saturable portion is magnetically saturated by the magnetic flux of the rotor to form a positioning portion.

Here, the plurality of positioning through holes are
The rotor accommodation through-holes may be provided so as to face each other with the through-holes interposed. Further, the stator is provided with a plurality of second saturable portions having a second predetermined length at positions facing each other with the rotor housing through hole interposed therebetween, and the second predetermined length is equal to the first predetermined length. The second saturable portion may be formed to be longer than a predetermined length of 1, and may be magnetically saturated by a magnetic flux generated in the stator by an alternating signal supplied to the coil.

The positioning through hole may be formed in a circular shape. Further, the positioning through hole may be formed in a polygonal shape. Further, according to the present invention, there is provided an electronic timepiece in which each of the stepping motors is used as the stepping motor in an electronic timepiece in which the time hand is rotationally driven by the driving force of the stepping motor. The time hand of the electronic timepiece is rotationally driven by the driving force of the stepping motor.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a configuration diagram of a stepping motor according to a first embodiment of the present invention, and shows an example of a stepping motor having a configuration particularly suitable for an electronic timepiece. In FIG. 1, the stepping motor includes a stator 10 having a rotor housing through hole 103.
1. A magnetic core 10 integrated with a rotor 102 and a stator 101, which are rotatably arranged in a rotor housing through hole 103.
8. A coil 109 wound around the magnetic core 108 is provided.

The rotor 102 is magnetized to have two poles (S pole and N pole). Outer ends 118, 11 of the stator 101
In FIG. 9, a plurality of (two in the present embodiment) recesses (outer notches) are provided at positions facing each other with the rotor housing through hole 103 interposed therebetween.
106 and 107 are provided. Outer notches 106, 1
A plurality of saturable portions 110 and 111 (two in the present embodiment) forming the second saturable portion are formed between 07 and the rotor housing through hole 103. Saturable section 110,
111 has a second predetermined length. Further, the stator 101 is provided with a plurality of (two in the present embodiment) positioning through holes 104 and 105 at positions facing each other with the rotor housing through hole 103 interposed therebetween.

The line segment connecting the plurality of outer notches 106 and 107 and the line segment connecting the positioning through holes 104 and 105 are arranged so as to intersect with each other. Each positioning through hole 104,
A plurality of first predetermined lengths (two in this embodiment) extending from the ends of the positioning through holes 104, 105 to the rotor receiving through hole 103 are provided between the rotor receiving through hole 103 and the rotor receiving through hole 103. ), Saturable units 113 and 112 are provided. Each saturable section 112, 113 constitutes a first saturable section. The first predetermined length is configured to be shorter than the second predetermined length.

The saturable portions 112 and 113 are the rotor 102.
Of the saturable portion 112 and the positioning through-hole 105, and the saturable portion 1
13 and the region 116 formed by the through hole 104 for positioning, the saturable portions 112 and 113 are the rotor 102.
It is configured to perform substantially the same function as the inner notches 304 and 305 in FIG. 3 by being magnetically saturated by the magnetic flux of. That is, the regions 116 and 117 form a positioning portion. As a result, the coil 109
1 is not excited, the rotor 102 is in a position corresponding to the positioning portion as shown in FIG. 1, in other words, the axis A of the rotor 102 is orthogonal to the line segment connecting the regions 116 and 117. Stable in position and stopped.

On the other hand, the saturable portions 110 and 111 are not magnetically saturated by the magnetic flux of the rotor 102, but the coil 10
The magnetic flux is generated in the stator 101 by the alternating signal supplied to the magnetic pole 9 so as to be magnetically saturated. The stator 101 portion between each positioning through hole 104, 105 and the outer end portion 118, 119 of the stator 101 has a third portion.
Regions 114 and 115 having a predetermined length are formed. The third predetermined length is longer than the first predetermined length and the second predetermined length, and is not magnetically saturated by the magnetic flux of the rotor 102 and the magnetic flux generated when the coil 109 is excited. Is configured.

The operation of the stepping motor according to the first embodiment of the present invention constructed as above will be described.
As an initial state, it is assumed that the rotor 102 is stopped at the position corresponding to the positioning portion. In this state, when a rectangular wave pulse signal is supplied to the coil 109 and a current i is passed in the direction of the arrow in FIG. 1, a magnetic flux is generated in the stator 101 in the direction of the arrow C. The saturable portions 110 and 111, which are longer than the saturable portions 112 and 113, are magnetically saturated by the magnetic flux to have a high magnetic resistance, and then the stator 101.
Due to the interaction between the magnetic poles generated in 1) and the magnetic poles of the rotor 102, the rotor 102 rotates 180 degrees in the direction of arrow B in FIG. 1 and stably stops at the position corresponding to the positioning portion.

Next, when a pulse signal of a rectangular wave of opposite polarity is supplied to the coil 109 and a current is passed in the direction opposite to the arrow in FIG. 1, the saturable portions 110 and 111 are magnetically saturated in the same manner as described above. It becomes a high magnetic resistance, and thereafter, due to the interaction between the magnetic poles generated in the stator 101 and the magnetic poles of the rotor 102,
The rotor 102 rotates 180 degrees in the direction of arrow B in FIG. 1 and stably stops at the position corresponding to the positioning portion. After that, by supplying signals having different polarities (alternating signals) to the coil 109, the above-described operation is repeated, and the rotor 102 is continuously rotated by 180 degrees in the direction of arrow B, and at the same time the rotor 102 is It is possible to stably stop at a position corresponding to the positioning portion.

FIG. 2 is a block diagram of a stepping motor according to a second embodiment of the present invention, showing an example of a stepping motor having a configuration particularly suitable for an electronic timepiece. Further, in FIG. 2, the same parts as those in FIG. 1 are designated by the same reference numerals. The difference between the second embodiment and the first embodiment is that the positioning through hole is circular in the first embodiment, but is different in the second embodiment. The point is that the positioning through holes 201 and 202 are used.

Also in the second embodiment, between the outer notches 106 and 107 and the rotor accommodating through hole 103, the ends of the outer notches 106 and 107 reach the rotor accommodating through hole 103. A plurality of (two in this embodiment) saturable units 110 and 111 having a second predetermined length are provided. Each saturable section 110, 111 constitutes a second saturable section. Between the plurality of (two in the present embodiment) positioning through-holes 201 and 202 formed in the stator 101 and the rotor housing through-hole 103, from the end of each positioning through-hole 201, 202 to the rotor. Through hole 103 for accommodation
A plurality of (two in the present embodiment) saturable portions 112 and 113 having a first predetermined length are provided to reach the end portion of. Each saturable section 112, 113 constitutes a first saturable section. The first predetermined length is formed shorter than the second predetermined length.

The saturable parts 112 and 113 are connected to the rotor 102.
Of the saturable portion 112 and the positioning through-hole 202 and the saturable portion 113 and the positioning through-hole 201. Since the saturable portions 112 and 113 are magnetically saturated by the magnetic flux of the rotor 102, the inner notch 3 in FIG.
It is configured to perform the same function as 04, 305. That is, the areas 203 and 204 form a positioning portion. As a result, when the coil 109 is not excited, the rotor 102 has a position corresponding to the positioning portion as shown in FIG. 1, in other words, the axis A of the rotor 302.
However, it is stably stopped at a position orthogonal to the line segment connecting the regions 203 and 204.

On the other hand, the saturable portions 110 and 111 are not magnetically saturated by the magnetic flux of the rotor 102, but the coil 10
The magnetic flux is generated in the stator 101 by the alternating signal supplied to the magnetic pole 9 so as to be magnetically saturated. Regions 114 and 115 are provided in the stator 101 portion between the positioning through holes 201 and 202 and the outer end portion of the stator 101.
Are formed. Each positioning through hole 201, 202
To the outer end of the stator 101 through the regions 114, 115
Has a third predetermined length longer than the second predetermined length, and the magnetic flux of the rotor 102 and the coil 109 are formed.
Is configured so as not to be magnetically saturated by the magnetic flux generated by exciting the.

The stepping motor according to the second embodiment having the above structure operates in the same manner as the first embodiment. That is, by supplying signals having different polarities (alternating signals) to the coil 109, the rotor 102 is continuously rotated by 180 degrees in the direction of arrow B, and the rotor 102 is stabilized at a position corresponding to the positioning portion. Can be stopped automatically.

As described above, the stepping motor according to the embodiment of the present invention has the rotor housing through hole 103.
And a stator 101 having a positioning portion for determining a stop position of the rotor 102, a rotor 102 arranged in the rotor housing through hole 103, and a coil 109, and an alternating signal is supplied to the coil 109 to supply the stator 101. In the stepping motor in which the rotor 102 is rotated by generating a magnetic flux at the same time, and the rotor 102 is stably stopped at the position corresponding to the positioning portion, the positioning portion includes the end of the through hole 103 for housing the rotor. A plurality of positioning through holes 104, 105, 201, 202 formed in the stator 101 so as to form first saturable portions 112, 113 having a first predetermined length from the
The first saturable portions 112 and 113 are characterized in that they are magnetically saturated by the magnetic flux of the rotor 102.

A plurality of second saturable portions 11 having a second predetermined length are provided in the stator 101 so as to face each other with the rotor accommodating through holes 104, 105, 201, 202 interposed therebetween.
0 and 111 are provided, and the second predetermined length is formed to be longer than the first predetermined length. The second saturable unit 110 and 111 is configured to receive the alternating signal supplied to the coil 109. It is characterized in that it is magnetically saturated by the magnetic flux generated in the stator 101.

Therefore, since the through holes can be formed with high accuracy and stability and easily, the positioning through holes 104, 105, 201 and 202 can be formed with high accuracy, stability and easily. Therefore, the rotor housing through hole 303 and the rotor positioning through hole 104,
It becomes possible to easily form 105, 201, and 202 with high precision. Therefore, since a minute magnetic potential difference can be created with high accuracy, the gap between the rotor housing through hole 103 and the rotor 102 can be reduced, and the magnetic efficiency can be improved.

Further, the control of the magnetic potential difference depending on the lengths of the saturable regions 112 and 113 has an effect of facilitating fine adjustment because the formation of a desired shape and the accuracy control are convenient. In addition, the magnetic loss is reduced, the efficiency of the stepping motor is improved, the consumption current of the stepping motor is reduced, and the output can be increased. It is possible to rotate the rotor 302.

Further, in an electronic timepiece in which a time hand such as an hour hand and a minute hand is rotationally driven by a driving force of a stepping motor, if the stepping motor is used as the stepping motor for driving the time hand, it can be driven with a small energy. It becomes possible to provide a possible electronic timepiece. In each of the above-described embodiments, circular rotor positioning through holes 104, 10 are used as the rotor positioning through holes.
5 and the example of the rotor positioning through holes 201 and 202 having a rectangular shape have been described, various modifications such as a polygonal shape such as a triangular shape are possible.

[0031]

According to the present invention, the rotor can be rotated with a small amount of energy without deteriorating the basic characteristics of the stepping motor. Further, according to the present invention, it becomes possible to provide an electronic timepiece capable of driving the time hand with a small amount of energy.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a stepping motor according to a first embodiment of the present invention.

FIG. 2 is a configuration diagram of a stepping motor according to a second embodiment of the present invention.

FIG. 3 is a configuration diagram of a conventional stepping motor.

[Explanation of symbols]

101 ... Stator 102 ... Rotor 103 ... Rotor housing through holes 104, 105, 201, 202 ... Rotor positioning through holes 106, 107 ... Recesses (outer notches) 108 ... Magnetic core 109 ... Coil 110, 111 ... Second saturable section 112, 113 ... First saturable section 114, 115, 116, 117, 203, 204 ...
·region

Claims (6)

[Claims] 1. A stator having a rotor accommodating through hole and a positioning portion for determining a stop position of the rotor, a rotor disposed in the rotor accommodating through hole, and a coil, and an alternating signal to the coil. Is supplied to generate magnetic flux in the stator to rotate the rotor and stop the rotor at a position corresponding to the positioning portion. A plurality of positioning through holes formed in the stator so as to form a first saturable portion having a first predetermined length from the end of the hole;
The stepping motor according to claim 1, wherein the first saturable portion is magnetically saturated by the magnetic flux of the rotor. 2. The stepping motor according to claim 1, wherein the plurality of positioning through holes are provided at positions facing each other with the rotor housing through hole interposed therebetween. 3. The stator is provided with a plurality of second saturable portions having a second predetermined length at positions facing each other with the rotor housing through hole interposed therebetween, and the second predetermined length. Is formed to be longer than the first predetermined length, and the second saturable portion is magnetically saturated by the magnetic flux generated in the stator by the alternating signal supplied to the coil. Alternatively, the stepping motor according to item 2. 4. The stepping motor according to claim 1, wherein the positioning through hole is formed in a circular shape. 5. The stepping motor according to claim 1, wherein the positioning through hole is formed in a polygonal shape. 6. An electronic timepiece in which a time hand is rotationally driven by a driving force of a stepping motor, wherein the stepping motor according to any one of claims 1 to 5 is used as the stepping motor. .