JP2021150972A - Stator, stepping motor, movement, timepiece and method of manufacturing stator - Google Patents

Abstract

To provide a stator by which a magnetic flux can be easily obtained from a rotor magnet and sufficient strength can be obtained.SOLUTION: A stator includes: a magnetic plate material for the stator in which a through hole for a rotor is formed and a magnetic circuit is formed around the through hole for the rotor; and a non-magnetic region which is provided around the through hole and generates a magnetic pole around the through hole by excitation by a coil. The nonmagnetic region includes: a groove part whose cross-sectional area is reduced from one surface side of the magnetic plate material toward the other surface side along the thickness direction; and a foreign material layer which is fixed in the groove part and has permeability lower than that of the magnetic plate material.SELECTED DRAWING: Figure 5

Description

The present invention relates to a method for manufacturing a stator, a stepping motor, a movement, a timepiece, and a stator.

Conventionally, analog electronic clocks have been used in which pointers such as hour and minute hands are rotationally driven by a motor drive device. Further, in this type of analog electronic timepiece, a stepping motor is widely and generally used as a motor driving device.
The stepping motor includes a stator having a rotor through hole and a positioning portion (inner notch) for determining a rotor stop position, a rotor rotatably arranged in the rotor through hole, and a coil provided in the stator. Have.

Usually, in a stepping motor, an integrated stator is used in which narrow portions having a narrow width are provided at two places (180 degree intervals) around the through holes for the rotor to facilitate the saturation of magnetic flux. With this structure, it becomes easy to obtain the leakage magnetic flux that drives the rotor.

Conventionally, as this type of stator, the outer shape of the stator body is formed of a magnetic material, and a slit portion is formed in a portion of the stator body that minimizes the magnetic path cross-sectional area. There is known a structure in which a wire rod is pushed in and welded together (Patent Document 1).
Further, there is known a stator in which a stator is formed of a magnetic material and grooves are formed in the magnetically saturated portion of the stator from both the upper and lower surfaces at equal depths to form a thin-walled connecting portion (Patent Document 2).

Japanese Unexamined Patent Publication No. 5-056109 Japanese Unexamined Patent Publication No. 10-257949

However, according to the technique described in Patent Document 1, since a slit portion is formed which completely divides the stator body made of a magnetic material and the slit portion is filled with a wire rod, the stator body is magnetically formed through the slit portion. The structure is completely divided. In this case, the wider the slit portion, the higher the magnetic resistance, and there is a problem that magnetic flux leakage is likely to occur at that portion. As a result, there is a problem that the loss of magnetic flux from the rotor magnet and the coil increases and the magnetic efficiency decreases.
Further, although the magnetic efficiency can be maintained by narrowing the width of the slit portion, in this case, there is a problem that the process of forming and filling the narrow slit portion becomes difficult.
In the technique described in Patent Document 2, since a thin-walled connecting portion is provided in the magnetic saturation portion of the stator, the entire stator can be magnetically connected via the thin-walled connecting portion, but the thin-walled connecting portion is a machine. There is a problem that it becomes a weak part and is easily deformed by an external force.

In view of the above problems, the present invention can solve the problem that magnetic flux leakage is likely to occur in the magnetic saturation portion of the stator, and can easily obtain the magnetic flux from the rotor magnet and obtain sufficient strength. , A method of manufacturing a movement, a watch and a stator provided with the stator.

"1" In order to solve the above-mentioned problems, the stator according to one embodiment of the present invention includes a magnetic plate material for a stator in which a through hole for a rotor is formed and a magnetic path is formed around the through hole for the rotor. A non-magnetic region provided around the through hole and generating a magnetic pole around the through hole by excitation by a coil is provided, and the non-magnetic region is provided from one surface side of the magnetic plate material along the thickness direction of the other. It has a groove portion whose cross-sectional area is reduced toward the surface side, and a foreign matter layer which is fixed in the groove portion and has a magnetic permeability lower than that of the magnetic plate material.

In this embodiment, by providing the foreign matter layer in a part of the magnetic path, the magnetic flux consumed in the region can be significantly reduced, and the leakage magnetic flux for driving the rotor can be efficiently secured. In addition, the loss of magnetic potential can be prevented, and the holding force for magnetically stopping (stationing) and holding the rotor can be increased. Further, if the structure has a foreign matter layer fixed in the groove, the thickness of the magnetic plate material is reduced in the grooved portion, but the foreign matter layer reinforces and compensates for the decrease in the plate thickness, so that the mechanical strength of the stator is lowered. Can be supplemented.

"2" In the above-mentioned one form of the stator, the foreign matter layer may be formed of a non-magnetic material or a resin.

The foreign matter layer can be formed of a non-magnetic material or resin, but by providing these, the inside of the groove becomes a non-magnetic region, and magnetic poles can be generated around the through hole by excitation by a coil.

"3" In the stator of the one form, the bottom side of the groove does not reach the other surface of the magnetic plate material, and the foreign matter layer is placed on the bottom side of the groove and on the other surface side of the magnetic plate material. A configuration having a magnetic coupling portion that does not have can be adopted.

Since the magnetic coupling portion is provided on the bottom side of the groove, a magnetically stable stator can be provided due to the presence of the magnetic coupling portion. Further, if the structure has a non-magnetic molten portion in which the cross-sectional area decreases from one surface side of the magnetic plate material toward the other surface side along the thickness direction, the bottom side of the non-magnetic fused portion is narrowed. A magnetic proximity effect is generated in the portion, and a stator with improved magnetic stability can be provided.

"4" In the stator of the one form, it is possible to adopt a configuration in which the foreign matter layer is a melt-solidified portion containing an element different from the constituent elements of the magnetic plate material.

If a melt-solidified portion containing an element different from the constituent elements of the magnetic plate material is provided in the recess, the melt-solidified portion constitutes a non-magnetic region. For example, if the melt-solidified portion is formed by heating and melting by laser irradiation, the melted portion easily fits inside the recess, so that it is easy to obtain a structure in which the melt-solidified portion is securely housed in the recess.

"5" In the stator of the one form, a configuration in which the magnetic plate material contains a Ni—Fe alloy and the melt-solidified portion contains chromium can be adopted.

Since the magnetic plate material contains a Ni—Fe alloy, it can be made into a magnetic plate material having a high magnetic permeability, and a leakage magnetic field can be easily utilized by using a melt-solidified portion in a non-magnetic region. By containing chromium in the melt-solidified portion, the desired non-magnetic region can be obtained by utilizing the melt diffusion of chromium by laser irradiation.

"6" In the stator of the one form, it is possible to adopt a configuration in which the magnetic plate material has a main plate surface facing the main plate when assembled to the main plate of the movement, and a train wheel surface on the opposite side in the thickness direction.

"7" The stepping motor according to one embodiment of the present invention can adopt a configuration including the stator and a rotor arranged in the through hole.
"8" The watch movement according to one embodiment of the present invention can adopt a configuration including the stepping motor and a train wheel for transmitting the power of the stepping motor.
"9" The watch according to one embodiment of the present invention can adopt a configuration including the movement for the watch.

"10" The stator according to one embodiment of the present invention is provided with a magnetic plate material for a stator in which a through hole for a rotor is formed and a magnetic path is formed around the through hole for the rotor, and a magnetic plate material for the stator, and around the through hole. A non-magnetic region that generates a magnetic pole around the through hole by excitation by a coil is provided, and the non-magnetic region is located at a gap portion that divides a part of a magnetic path in the magnetic plate material and on both sides of the gap portion. It is characterized by having a metal-plated portion in which the ends of the magnetic plate material to be connected are connected to each other.

By providing a gap portion so as to divide a part of the magnetic path of the magnetic plate material, the gap portion can be made into a non-magnetic region. A part of the magnetic plate material is divided by providing the gap portion, but by providing the metal plating portion so as to bridge the gap portion, the ends of the magnetic plate material located on both sides of the gap portion are magnetically bonded to each other. .. Therefore, the magnetic flux consumed in the gap portion, which is the non-magnetic region, can be significantly reduced, the leakage magnetic flux for driving the rotor can be efficiently secured, and the magnetic efficiency can be improved. In addition, the loss of magnetic potential can be prevented, and the holding force for magnetically stopping (stationing) and holding the rotor can be increased.

"11" In the method for manufacturing a stator according to one embodiment of the present invention, the metal-plated portion can be formed by Ni plating.
Ni plating has excellent corrosion resistance, and there is no problem in the durability of the metal plated portion when the stator is applied for watches.

According to this embodiment, by providing the foreign matter layer in a part of the magnetic path, the magnetic flux consumed in the region can be significantly reduced, and a stator capable of efficiently securing the leakage magnetic flux for driving the rotor can be provided.
Further, it is possible to provide a stator capable of preventing loss of magnetic potential and increasing the holding force for magnetically stopping (stationing) and holding the rotor.
Further, if the structure has a foreign matter layer fixed in the groove, the thickness of the magnetic plate material is reduced in the grooved portion, but the foreign matter layer reinforces and compensates for the decrease in the plate thickness, so that the mechanical strength does not decrease. Can be provided.

It is a block diagram which shows the clock which includes the stator, the stepping motor, and the movement for a clock which concerns on 1st Embodiment. It is a perspective view which shows the schematic structure example of the stepping motor which concerns on 1st Embodiment. It is a front schematic diagram of the stator which concerns on 1st Embodiment. It is a front schematic diagram of the stepping motor which concerns on 1st Embodiment. It is sectional drawing of the main part of the stator. It is sectional drawing of the main part which shows the 2nd Embodiment of the stator. It is a process drawing which shows an example of the manufacturing method of the stator which concerns on 2nd Embodiment. It is a top view which shows the hoop material before the press punching process about the stator which concerns on 2nd Embodiment. It is sectional drawing of the main part which shows the modification in the case of manufacturing the stator which concerns on 2nd Embodiment. It is explanatory drawing which shows the magnetic field φR in the structure which formed the divided part in a part of a stator, and filled the said part with resin. It is explanatory drawing which shows the magnetic field φR in the stator which concerns on 1st Embodiment. It is a partial cross-sectional view which shows the stator which concerns on 3rd Embodiment. It is a partial cross-sectional view which shows the stator which concerns on 4th Embodiment. It is a partial cross-sectional view which shows the stator which concerns on 5th Embodiment. It is a partial cross-sectional view which shows the stator which concerns on 6th Embodiment. It is a partial cross-sectional view which shows the stator which concerns on 7th Embodiment.

Hereinafter, an example of a timepiece, a movement for a timepiece, a stepping motor, and a stator according to an embodiment of the present invention will be described with reference to the drawings. Further, in the drawings used in the following description, in order to make each member recognizable in size, the scale of each member may be appropriately changed and displayed.

"First Embodiment of a watch, a movement for a watch, a stepping motor, and a stator"
FIG. 1 is a block diagram showing a timepiece 1 using a stepping motor and a timepiece movement according to the first embodiment. In the present embodiment, an analog electronic clock will be illustrated and described as an example of the clock.
As shown in FIG. 1, the clock 1 includes a battery 2, an oscillation circuit 3, a frequency dividing circuit 4, a control circuit 5, a pulse drive circuit 6, a stepping motor 7, and an analog clock unit 8.
Further, the analog clock unit 8 includes a train wheel 11, an hour hand 12, a minute hand 13, a second hand 14, a calendar display unit 15, a clock case 81, and a clock movement 82 (hereinafter referred to as a movement 82). In the present embodiment, when one of the hour hand 12, the minute hand 13, the second hand 14, and the calendar display unit 15 is not specified, it is described as a guideline.

The oscillation circuit 3, the frequency dividing circuit 4, the control circuit 5, the pulse drive circuit 6, the stepping motor 7, and the train wheel 11 are components of the movement 82. A module provided with a stepping motor 7 and a train wheel 11 can be referred to as a mechanical module. The train wheel 11 transmits the power of the stepping motor 7.
Generally, the mechanical body of a timepiece formed by a device such as the time reference of the timepiece 1 is referred to as a movement. Electronic ones are sometimes called modules. In its completed state as a watch, the movement is fitted with, for example, a dial and pointers and housed in a watch case.

The battery 2 is, for example, a lithium battery, a so-called button battery. The battery 2 may be a solar cell and a storage battery for storing the electric power generated by the solar cell. The battery 2 supplies electric power to the control circuit 5.

The oscillation circuit 3 is a passive element used to oscillate a predetermined frequency from its mechanical resonance, for example, by utilizing the piezoelectric phenomenon of quartz. Here, the predetermined frequency is, for example, 32 [kHz].
The frequency dividing circuit 4 divides the signal of a predetermined frequency output by the oscillation circuit 3 into a desired frequency, and outputs the divided signal to the control circuit 5.

The control circuit 5 measures the time using the divided signal output by the frequency dividing circuit 4, and generates a drive pulse based on the result over time. The control circuit 5 generates a drive pulse for forward rotation when the pointer is moved in the forward rotation direction. When the pointer is moved in the reverse direction, the control circuit 5 generates a drive pulse for reverse rotation. The control circuit 5 outputs the generated drive pulse to the pulse drive circuit 6.
The pulse drive circuit 6 generates a drive pulse for each pointer in response to a drive instruction output by the control circuit 5. The pulse drive circuit 6 outputs the generated drive pulse to the stepping motor 7.

The stepping motor 7 moves the pointers (hour hand 12, minute hand 13, second hand 14, calendar display unit 15) according to the drive pulse output by the pulse drive circuit 6. In the example shown in FIG. 1, for example, one stepping motor 7 is provided for each of the hour hand 12, the minute hand 13, the second hand 14, and the calendar display unit 15.

The hour hand 12, the minute hand 13, the second hand 14, and the calendar display unit 15 are each moved by the stepping motor 7.
The hour hand 12 makes one rotation in 12 hours when the pulse drive circuit 6 drives the stepping motor 7. The minute hand 13 makes one rotation in 60 minutes when the pulse drive circuit 6 drives the stepping motor 7. The second hand 14 makes one rotation in 60 seconds when the pulse drive circuit 6 drives the stepping motor 7. The calendar display unit 15 is, for example, a pointer for displaying a date, and the pulse drive circuit 6 drives the stepping motor 7 to make one rotation in 24 hours.

Next, a schematic configuration of the stepping motor 7 according to the present embodiment will be described.
FIG. 2 is a perspective view showing a schematic configuration of the stepping motor 7 according to the present embodiment. As shown in FIG. 2, the stepping motor 7 includes a stator 201, a rotor 202, a magnetic core 208, a coil 209, and a screw 220. As shown in FIG. 3, the stator 201 is composed of an elongated magnetic plate material 201A for forming an arm-shaped yoke, and mounting pieces 201B and 201C are formed on both ends of the magnetic plate material 201A in the length direction.
A through hole 203 for a rotor is formed in an intermediate portion of the stator 201 in the length direction, and a screw hole 218a and a screw hole 218b are formed in the mounting pieces 201B and 201C.
The rotor 202 is rotatably arranged in the rotor through hole 203.
The coil 209 is wound around the magnetic core 208.
When the stepping motor 7 is used for an analog electronic timepiece, the stator 201 and the magnetic core 208 are fixed to the main plate 51 of the movement 82 by screws 220 and magnetically joined to each other. In this embodiment, the screws are fixed for magnetic joining, but the screw fixing is not limited as long as the magnetic joining is possible.

Here, the stator 201 will be further described with reference to FIG.
FIG. 3 is a front schematic view of the stator 201 according to the present embodiment. In FIG. 3, the longitudinal direction of the stator 201 is the y-axis direction, and the lateral direction is the x-axis direction.
The stator 201 shown in FIG. 3 is manufactured by a method for manufacturing a motor stator, which will be described later. As shown in FIG. 3, notches 204 and 205 are formed in the rotor through hole 203. Further, the stator 201 is formed with narrow portions 210 and 211 so as to be located on both ends of the rotor through hole 203 in the X-axis direction.
The magnetic plate material 201A constituting the stator 201 is formed of a plate material made of a high magnetic permeability material such as an Fe—Ni (iron-nickel) alloy. Further, the narrow portions 210 and 211 are non-magnetic regions. The detailed structure of the non-magnetic region will be described in detail later.

When the stepping motor 7 is used for a timepiece, an example of each size of the stator 201 is described below. The hole diameter of the rotor through hole 203 is about 1.5 to 2 mm. The width of the narrowest portion of the narrow portions 210 and 211 is about 0.1 mm to 0.2 mm. The thickness of the stator 201 is about 0.5 mm ± 0.1 mm. The length in the longitudinal direction is about 10 mm.

Next, an outline of the stepping motor 7 according to the present embodiment will be described with reference to FIG.
FIG. 4 is a front schematic view of the stepping motor 7 according to the present embodiment.
The stepping motor 7 shown in FIG. 4 includes a rotor through hole 203, a stator 201, a rotor 202, a magnetic core 208, a coil 209, and narrow portions 210 and 211.

In the stator 201, a magnetic path R is formed around the rotor through hole 203. The rotor 202 is a two-pole rotor rotatably arranged in the rotor through hole 203. The magnetic core 208 is joined to the stator 201. The coil 209 is wound around a magnetic core 208.

The narrow portions 210 and 211 are provided in portions that do not interfere with the cutout portions 204 and 205 provided in the rotor through hole 203 in order to secure a stable position of the rotor 202. The coil 209 has a first terminal OUT1 and a second terminal OUT2.

The rotor through hole 203 has a circular hole shape in which a plurality of (two in the example of FIG. 4) half-moon-shaped notches (inner notches) 204 and 205 are integrally formed at the facing portions of the through holes having a circular contour. It is configured in. These notch portions 204 and 205 are configured as positioning portions for determining the stop position or the stationary stable position of the rotor 202. For example, the notch (inner notch) 204 has an effect of stabilizing the position of the rotor by lowering its potential energy when the rotor is in a predetermined position.

The rotor 202 is magnetized in two poles (S pole and N pole).
In the state where the coil 209 is not excited, the rotor 202 is located at a position corresponding to the positioning portion as shown in FIG. 4, in other words, the magnetic pole axis A of the rotor 202 is a line segment connecting the cutout portions 204 and 205. It is stably stopped (stationary) at a position (angle θ _{0 position) orthogonal to the above.}

Narrow portions 210 and 211 in the non-magnetic region are formed in a part of the magnetic paths R (two places in the example of FIG. 4) provided around the through hole 203 for the rotor. Here, the width of the cross section of the narrow portion of the stator 201 is defined as the cross-sectional width t, and the width in the direction along the magnetic path is defined as the gap width w. The narrow portions 210 and 211 are formed in a region defined by a cross-sectional width t and a gap width w.
In the following description, in the stator 201, the outer circumference of the narrow portion 211 is referred to as a point a1, the inside of the narrow portion 211 is referred to as a point b1, the vicinity of the narrow portion 211 and the space between the outer circumference and the inner circumference of the magnetic path R is defined as a point c. Define.

Next, the operation of the stepping motor 7 according to the present embodiment will be described with reference to FIG.
First, a drive pulse signal is supplied from the pulse drive circuit 6 between the terminals OUT1 and OUT2 of the coil 209 (for example, the first terminal OUT1 side is the positive electrode and the second terminal OUT2 side is the negative electrode), and the current i is in the direction of the arrow in FIG. A magnetic flux is generated in the stator 201 in the direction of the broken line arrow.

In the present embodiment, the narrow portions 210 and 211, which are non-magnetic regions, are formed, and the magnetoresistance in the non-magnetic regions is increased. Therefore, it is not necessary to magnetically saturate the region corresponding to the conventional "narrow portion", and the leakage magnetic flux can be easily secured. After that, the interaction between the magnetic poles generated in the stator 201 and the magnetic poles of the rotor 202 causes the rotor 202. Rotates 180 degrees in the direction of the arrow in FIG. 4, and the magnetic flux axis stably stops (stationary) at an _{angle θ 1 position.}
It should be noted that the rotational direction (counterclockwise direction in FIG. 4) for rotating the stepping motor 7 to perform normal operation (hand movement operation because each embodiment of the present invention is an analog electronic clock) is in the positive direction. And the opposite (clockwise direction) is the reverse direction.

Next, the pulse drive circuit 6 supplies drive pulses of opposite polarity to the terminals OUT1 and OUT2 of the coil 209 (the first terminal OUT1 side is the negative electrode and the second terminal OUT2 side so as to have the opposite polarity to the drive). When a current is passed in the direction of the counter-arrow in FIG. 4, magnetic flux is generated in the stator 201 in the direction of the counter-dashed arrow.
After that, since the narrow portions 210 and 211 which are non-magnetic regions are formed as described above, the leakage magnetic flux can be easily secured, and the interaction between the magnetic poles generated in the stator 201 and the magnetic poles of the rotor 202 causes the magnetic flux to leak. , The rotor 202 rotates 180 degrees in the same direction (positive direction) as described above, and the magnetic flux axis stably stops (stationarily) at the angle θ0 position.

After that, by supplying signals having different polarities (alternating signals) to the coil 209 in this way, the operation is repeated, and the rotor 202 can be continuously rotated by 180 degrees in the arrow direction. ..

As described above, since the narrow portions 210 and 211 which are non-magnetic regions are formed in a part of the magnetic path R formed around the through hole 203 for the rotor, the magnetic flux consumed in the region is significantly increased. It is possible to efficiently secure the leakage magnetic flux that drives the rotor 202.
Further, by forming the narrow portions 210 and 211 which are non-magnetic regions in the portion which was conventionally regarded as the "narrow portion" to reduce the magnetic permeability, the magnetic flux generated from the rotor 202 itself is also the region. Consumption is suppressed. As a result, the loss of the magnetic potential can be prevented, and the holding force for magnetically stopping (stationing) and holding the rotor 202 can be increased.

Further, after the portion that was conventionally regarded as the "narrow portion" is saturated with the magnetic flux on the OUT1 side (negative electrode) and rotated, it occurs on the OUT1 side (negative electrode) to rotate on the OUT2 side (positive electrode). It was necessary to cancel the residual magnetic flux. However, according to the present embodiment, since the residual magnetic flux in the region is significantly reduced, the time required for canceling the residual magnetic flux is not required, and the time until the rotation is converged can be shortened. Therefore, according to the present embodiment, it is possible to maintain operational stability when performing high-speed hand movement, and it is possible to increase the drive frequency.

FIG. 5 is a partial cross-sectional view showing an example structure of narrow portions 210 and 211 having a non-magnetic region. From one surface 201a side of the magnetic plate material 201A constituting the stator 201 (upper surface side in FIG. 5; as an example, a train wheel surface) to the other surface 201b side (lower surface side in FIG. 5: along the thickness direction of the magnetic plate material 201A: As an example, a groove 201D is formed in which the cross-sectional area gradually decreases toward the main plate surface). In the example shown in FIG. 5, the groove 201D is formed in a V-shaped cross section. The train wheel surface and the main plate surface are formed on the magnetic plate material 201A so as to be located on opposite sides in the thickness direction.
Further, the groove 201D is formed with a foreign matter layer 206 formed of an insulator such as a non-magnetic material, a low magnetic permeability material, or a resin, which is a material different from the material constituting the magnetic plate material 201. The foreign matter layer 206 is filled inside the groove 201D so as to fill almost the entire groove 201D, and is fixed to the inside of the groove 201D. The bottom portion 201f of the groove portion 201D does not reach the other surface 201b of the magnetic plate material 201A. Therefore, a magnetic coupling portion 201G formed of a high magnetic permeability material constituting the magnetic plate material 201A is formed between the other surface 201b of the magnetic plate material 201A and the bottom portion 201f of the groove portion 201D (or the bottom portion 206a of the foreign matter layer 206). Has been done.

The depth of the groove 201D is preferably about 30% to 99% of the plate thickness of the magnetic plate material 201A. When the depth of the groove 201D is shallower than 30%, it becomes difficult to obtain the effect of providing the groove 201D to provide the non-magnetic region, and when the depth is deeper than 99%, the groove 201D substantially penetrates the magnetic plate member 201A. Therefore, the magnetic coupling between the high magnetic permeability materials located on both sides of the groove 201D becomes insufficient. In addition, since the bottom surface has a deformed portion, the assembling property is deteriorated.

FIG. 6 shows the stator 200 of the second embodiment, in which the stator 200 has a foreign matter layer (non-magnetic melted portion) 207 formed by a melt-solidified portion provided inside the groove portion 201E provided in the magnetic plate material 201A. Have.
In the foreign matter layer 207 shown in FIG. 6, the chromium paste in the recess formed on the surface 201a side of the magnetic plate material 201A is irradiated with a laser to melt the chromium paste, and the chromium is melted on the magnetic plate material 201A side by the manufacturing method described below. It is formed by diffusing and melting the melted portion and solidifying the melted portion.
The bottom 207a of the foreign body layer 207 has a narrowed shape, but the bottom 207a does not reach the other surface 201b. Therefore, in FIG. 6, a magnetic coupling portion 201G formed of a high magnetic permeability material constituting the magnetic plate material 201A is formed on the lower side of the bottom portion 207a.

<Manufacturing method of stator having non-magnetic molten part>
Hereinafter, an example of the method for manufacturing the stator 200 of the second embodiment will be described with reference to FIG. 7. FIG. 7 is a process diagram showing an example of a method for manufacturing the stator 200 according to the second embodiment.

(1st manufacturing process 1st press (creating guide holes))
In the first manufacturing process, a manufacturing system 300 equipped with a press working apparatus 302 is used. In FIG. 7, reference numeral 301 indicates a wound body before processing in which the hoop material 310 before pressing is wound. Reference numeral 303 indicates a wound body after processing in which the hoop material after pressing is wound. Reference numeral 310 indicates a hoop material after pressing. In FIG. 7, the longitudinal direction of the hoop material 310 is the x-axis direction, and the lateral direction is the y-axis direction. The width of the hoop material 310 in the lateral direction is, for example, 16.5 mm.

The press working apparatus 302 intermittently and continuously forms a plurality of positioning guide holes 312 and 313 at both ends in the width direction with respect to the magnetic plate material (plate material such as 38 permalloy) in the state of the hoop material. Further, in the press working apparatus 302, a V-shaped groove (groove portion) 305 is continuously press-formed on the magnetic plate material at a desired position in the y-axis direction at the same time as punching or separately from punching. Functions have been added. The desired position in the y-axis direction is a region for creating the narrow portions 210 and 211, which are non-magnetic regions in the stator 201 shown in FIG. The paste coating device 322 forms the V-shaped groove 305 in a line shape or an intermittent line shape at a desired position based on the position of the guide hole. The manufacturing system 300 winds up the hoop material after pressing to obtain a wound body 303.

(2nd manufacturing process non-magnetic region creation)
In the second manufacturing step, the manufacturing system 300 includes a paste coating device 322 for applying a paste of chromium (Cr), a drying device 323, a laser irradiation device 324, and a cleaning device 325. Further, reference numeral 321 indicates a wound body in which the hoop material after pressing is wound in the first manufacturing step. Reference numeral 326 indicates a wound body in which the hoop material 310 is wound after the non-magnetic region is created.

The paste coating device 322 continuously pastes and coats chrome on the hoop material at a desired position in the y-axis direction along the x-axis direction (coating step). The paste coating device 322 mixes, for example, chromium with a binder or a solvent to form a paste, and dispenses the paste. That is, the paste coating device 322 is a dispenser. The desired position in the y-axis direction is a region for creating the narrow portions 210 and 211, which are non-magnetic regions in the stator 201 shown in FIG. Therefore, the paste coating device 322 applies the chrome paste along the V-shaped groove 305 formed earlier.
The paste coating device 322 applies the chrome paste in a line shape or an intermittent line shape at a desired position based on the position of the guide hole. The coating thickness of the chrome paste is, for example, 150 to 200 μm. The drying device 323 dries the applied chrome paste. By this drying treatment, the solvent in the chrome paste is volatilized and the chrome paste layer is fixed. FIG. 9 shows an example of a state in which the chrome paste 331 is applied to the V-shaped groove 305.

Next, the laser irradiation device 324 irradiates the area coated with the chrome paste 331 with a laser (laser processing step). The laser is preferably a fiber laser having a deep discharge depth. As a result, the chrome in the applied chrome paste 331 is sufficiently dissolved in the base material (permalloy base material) side. Then, diffusion melting occurs between the applied chromium and the permalloy base material, and a region having a chromium weight ratio of 15% or more is formed inside the permalloy base material. The region where the chromium weight ratio is 15% or more is a guideline for reducing the magnetic permeability of the high magnetic permeability material constituting the magnetic plate material, and this region is a substantially non-magnetic region.
By laser irradiation, the coated area of the chromium paste 331 is heated to 1900 ° C. or higher, which is higher than the melting point of the permalloy material and chromium. The diameter of the incident side of the laser is about 0.3 to 0.5 mm. Further, it is preferable that the laser irradiation device 324 irradiates the laser in the x-axis direction at intervals of, for example, about 25 μm. As a result, the heat applied to the permalloy base material (hoop material) due to laser irradiation can be reduced.

A laser is irradiated to the area coated with the chromium paste 331, the chromium paste 331 is melted to diffuse and melt the chromium on the magnetic plate material 201A side, and the molten portion is solidified to form a foreign matter layer (non-magnetic) having a cross-sectional shape shown in FIG. Melted part) 207 is formed. The cross section of the foreign matter layer 207 has a lower constriction shape shown in FIG. 6 as an example. By laser irradiation, chromium diffuses and solidifies while melting in the plate thickness direction of the hoop material, so that the shape of the initially formed V-shaped groove 305 is not maintained and a foreign matter layer 207 larger than the V-shaped groove 305 is generated. .. In FIG. 6, the outline of the V-shaped groove 305 before the laser irradiation is drawn by a chain line.
The bottom portion 207a of the foreign matter layer 207 has a narrowed shape, but the bottom portion 207a does not reach the other surface 201b of the magnetic plate material 201A. Therefore, in FIG. 6, a magnetic coupling portion 201G formed of a high magnetic permeability material constituting the magnetic plate material 201A is formed on the lower side of the bottom portion 207a.

The cleaning device 325 removes unnecessary parts of the applied chrome paste by cleaning with a solvent. Reference numeral 310A is a plan view showing the hoop material after laser irradiation and cleaning. In the hoop material 310A, reference numeral 331 indicates a non-magnetic region. The width of the non-magnetic region in the y-axis direction is about 0.3 to 0.5 mm. As described above, in the second manufacturing step, a linear non-magnetic region continuous with respect to the hoop material in the x-axis direction is formed at a predetermined position in the y-axis direction. The time required for cleaning the hoop material 310A is, for example, 5 minutes.
After cleaning, the manufacturing system 300 winds up the hoop material 310A after forming the non-magnetic region to form a winding body 326.

(Third manufacturing process 2nd press (finishing))
In the third manufacturing process, the manufacturing system 300 includes a press punching device 342. Further, reference numeral 341 indicates a wound body in which the hoop material 310A after the second manufacturing step is wound. Reference numeral 343 indicates a wound body in which the hoop material after pressing through the third manufacturing step is wound.

As described above, as shown in FIG. 6, the foreign matter layer 207 whose cross-sectional area gradually decreases from one surface 201a side of the magnetic plate member 201A toward the other surface 201b side can be formed.

As described above, when the stepping motor 7 is used for an analog electronic timepiece, the stator 201 and the magnetic core 208 are fixed to the main plate 51 of the movement 82 by screws 220 as shown in FIG. Be joined.

The press punching device 342 uses the positions of the guide holes 312 and 313 of the hoop material 310A as a reference, and as shown in FIG. 8, for example, the width of the stator 201 is narrowed at a portion (melt diffusion region) where the chromium weight ratio is 15% or more. Press punching is performed so that the portions 210 and 211 are formed.
FIG. 8 is a plan view showing the hoop material 310A before press punching of the stator 201 according to the present embodiment. The stator 201'shown in FIG. 7 is a stator before magnetic annealing in the fourth manufacturing process. In FIG. 8, reference numeral 201 ″ indicates a position where press punching of the stator 201 ′ is performed. In the press punching, a part of the non-magnetic region is punched and processed into a shape surrounding the rotor 202 for the stepping motor 7. That is, the rotor through hole 203 can be formed at the same time by the third manufacturing step.
As a result, the outer shape of the stator 201'in which the chrome weight ratio differs between the narrow portion and the other portion is completed.

(4th manufacturing process magnetic annealing)
In the fourth manufacturing process, the manufacturing system 300 includes an annealing furnace 351.
The annealing furnace 351 performs a high temperature annealing treatment on the stator 201'. As a result, residual stress is removed / relaxed by press working in the third manufacturing process.

The manufacturing system 300 manufactures the stator 200 shown in FIG. 6 by the first to fourth manufacturing steps described above.
According to the stator 200 manufactured in the above manufacturing process, it is possible to reduce thermal deformation due to laser irradiation when forming a non-magnetic region.

Up to this point, the method of manufacturing the stator 200 shown in FIG. 6 having the foreign matter layer 207 has been described, but the stator 201 shown in FIG. 5 having the foreign matter layer 206 can be manufactured by using a part of the apparatus shown in FIG. ..
In the first manufacturing process, the same fixing as in the first manufacturing process described above is performed until the V-shaped groove 305 is created. When the stator 201 is manufactured, the chrome paste is not applied in the second manufacturing step, and a resin coating device is provided instead of the coating device. When the foreign matter layer 206 is made of resin by using this resin coating device, the V-shaped groove 305 is filled with a resin material such as an adhesive, a thermosetting resin, and an ultraviolet curable resin in the second manufacturing step. When filling a resin having a weak adhesive force, it is preferable to fill the resin layer after applying the adhesive layer.
When the thermosetting resin is applied, it is heated to a predetermined temperature by a separately provided heating device to cure the thermosetting resin. When an ultraviolet curable resin is used, the ultraviolet curable resin is cured by irradiating the ultraviolet with an ultraviolet irradiation device provided separately. When the adhesive is applied, the adhesive is cured under the curing conditions of the adhesive to form a foreign matter layer 206 formed of each resin.
When a non-magnetic material is filled as the foreign matter layer 206, a necessary non-magnetic material is filled in, and a joining method such as adhesion, pressure, heat pressure bonding, diffusion joining is carried out, and the foreign matter layer 206 is formed in the V-shaped groove 305. Should be formed.

The stator 200 or stator 201 manufactured as described above is incorporated in the stepping motor 7 as described above with reference to FIG. 2, and is incorporated in the movement 82 of the timepiece 1 as shown in FIG.
In the present embodiment, since the regions provided with the foreign matter layers 206 and 207 are continuously integrated by the magnetic coupling portion 201G adjacent to them, the portion provided with the foreign matter layers 206 and 207 has a mechanically weak portion. Not. Therefore, it is possible to provide the stators 200 and 201 which do not have a weak portion in strength in the region where the foreign matter layers 206 and 207 are provided.
Further, since the magnetic coupling portion 201G is provided on the bottom side of the foreign matter layers 206 and 207, it is possible to provide the stators 200 and 201 that are magnetically stable due to the presence of the magnetic coupling portion 201G. Further, if the structure has foreign matter layers 206 and 207 whose cross-sectional area decreases from one surface 201a side of the magnetic plate material 201A toward the other surface 201b side along the thickness direction, the non-magnetic molten portions 206 and 207 It is possible to provide the stators 200 and 201 in which the magnetic proximity effect is generated in the narrowed portion on the bottom side of the surface and the magnetic stability is enhanced.

As described in Patent Document 1 and the like, FIG. 10 shows a wire rod in which a divided portion that completely divides the magnetic plate material 201A constituting the stator in the thickness direction is formed, and the divided portion is formed of a non-magnetic material. The stator 400 of the conventional structure obtained by joining in 401 is shown.
When a rotor is incorporated into the stator 400 having the conventional structure, the width W of the wire rod 401 and the magnetic flux φR obtained from the rotor magnet are wide according to the width of the wire rod 401, as shown in FIG. As W becomes larger, it leaks to the outside of the magnetic circuit, so that the magnetic efficiency tends to decrease.

FIG. 11 shows the relationship between the width W of the groove 201D and φR obtained from the rotor magnet when the rotor is incorporated in the stator 201 provided with the foreign matter layer 206 in the lower constricted groove 201D. As shown in FIG. 11, according to the width W of the groove portion 201D, as the width W becomes larger, φR becomes closer to a constant value.
This is because, in the stator 400 having a magnetically completely divided portion, the wider the non-magnetic length, the higher the magnetoresistance, and the magnetic flux leakage at that portion is likely to occur, and the magnetic flux φR from the rotor magnet is increased. This is because it is difficult to obtain. On the other hand, in the structure shown in FIG. 11, since it has the magnetic coupling portion 201G, it is not magnetically divided in the peripheral region of the groove portion 201D, and the magnetic resistance remains low. Therefore, the structure shown in FIG. 11 has a structure in which the magnetic flux φR from the rotor magnet can be easily obtained regardless of the non-magnetic length.

"Third to sixth embodiment of the stator"
The groove portions 201D and the groove portions 305 formed in the stators 200 and 201 according to the first embodiment and the second embodiment are both groove portions having a simple V-shaped cross section, but the groove portions used in the present invention have these shapes. Not constrained by.
FIG. 12 shows the stator 402 according to the third embodiment in which the groove portion 201K is formed on the magnetic plate material 201A. It is formed by the formed bottom surface 201n. As shown in FIG. 12, the bottom surface 201n of the groove portion 201K may be a surface parallel to and flat with respect to the other surface 201b of the magnetic plate material 201A. The foreign matter layer 406 is filled inside the groove 201K.
In FIG. 12, a magnetic coupling portion 201H formed of a high magnetic permeability material constituting the magnetic plate material 201A is formed on the lower side of the bottom surface 201n.

FIG. 13 shows the stator 403 according to the fourth embodiment in which the groove portion 201L is formed on the magnetic plate material 201A. It is formed by the concave curved bottom surface 201p. As shown in FIG. 13, the bottom surface 201p of the groove portion 201L may have a concave curved surface shape. The inside of the groove 201L is filled with the foreign matter layer 407.
In FIG. 13, a magnetic coupling portion 201H formed of a high magnetic permeability material constituting the magnetic plate material 201A is formed on the lower side of the bottom surface 201p.

FIG. 14 shows the stator 404 according to the fifth embodiment in which the groove portion 201Q is formed on the magnetic plate material 201A, and the groove portion 201Q has two inner side surfaces 201r and 201r in the direction orthogonal to one surface 201a of the magnetic plate material 201A. And the concave curved bottom surface 201s formed on the bottom side of them. As shown in FIG. 14, the inner side surface 201r of the groove portion 201Q may not be inclined, and the bottom surface 201s may have a concave curved surface shape. The inside of the groove 201Q is filled with the foreign matter layer 408.
In FIG. 14, a magnetic coupling portion 201H formed of a high magnetic permeability material constituting the magnetic plate material 201A is formed on the lower side of the bottom surface 201s.

FIG. 15 shows the stator 405 according to the sixth embodiment in which the groove portion 201T is formed in the magnetic plate material 201A, and the groove portion 201T has two inner side surfaces 201r on the left and right in an direction orthogonal to one surface 201a of the magnetic plate material 201A. It is formed by 201r and a bottom surface 201u having a V-shaped cross section formed on the bottom side thereof. As shown in FIG. 15, the inner side surface 201r of the groove portion 201T may not be inclined, and the bottom surface 201u may be a sharp-pointed surface. The inside of the groove 201T is filled with the foreign matter layer 409.
In FIG. 15, a magnetic coupling portion 201H formed of a high magnetic permeability material constituting the magnetic plate material 201A is formed on the lower side of the bottom surface 201u.

Regardless of the shape of the groove and the shape of the foreign matter layer shown in FIGS. 12 to 15, since the magnetic coupling portion 201H is provided, the same action and effect as the structure described above with reference to FIG. 11 can be obtained.
As shown in FIGS. 12 to 15, various shapes can be adopted for the groove portion. In any case, if the groove portion has a magnetic coupling portion 201H and the groove portion has a downward constriction shape, the foreign matter layer gradually faces downward. As the value becomes smaller, the proximity effect in the case of magnetic coupling occurs as it goes downward, and it is possible to provide a stator that can efficiently secure the leakage magnetic flux.

FIG. 16 shows the stator 410 according to the seventh embodiment in which the groove portion 201W is formed in the magnetic plate material 201A, and the groove portion 201W has a gap having a constant width so as to reach from one surface 201a of the magnetic plate material 201A to the other surface 201b. It is formed so as to open a part G.
Further, a metal plating portion 410 formed by Ni plating is formed on the other surface 201b of the magnetic plate material 201A so as to connect the other surfaces 201b of the magnetic plate material 201A located on both sides of the gap portion G. A portion of the metal-plated portion 411 adjacent to the gap portion G constitutes a magnetic coupling portion. Since the portion of the metal plating portion 411 adjacent to the gap portion G constitutes the magnetic coupling portion 411H, the metal plating portion is preferably a metal material having a high magnetic permeability and is formed of a metal material that can be formed by plating. ..

The metal plating portion 411 may cover the entire other surface 201b of the magnetic plate material 201A, but may mainly cover a position adjacent to the gap portion G.
Further, when nothing is filled inside the gap layer G, air exists inside the gap layer G, and this air layer constitutes the filling layer. A foreign matter layer (not shown) may be provided so as to fill the gap portion G. Further, the gap portion G may be formed with a taper in which the upper side shown in FIG. 16 is wide and the lower side is narrow.

Even with the structure shown in FIG. 16, by providing a foreign matter layer in a part of the magnetic path, the magnetic flux consumed in the region can be significantly reduced, and the leakage magnetic flux for driving the rotor can be efficiently secured. Can be provided.
Further, it is possible to provide the stator 410 which can prevent the loss of the magnetic potential and can increase the holding force for magnetically stopping (stationing) and holding the rotor.
Further, when a structure in which the foreign matter layer is fixed in the groove is adopted, the foreign matter layer reinforces and compensates for the decrease in the plate thickness, so that it is possible to provide a stator in which the mechanical strength does not decrease.
The metal-plated portion 411 may be formed of any material as long as it has a high magnetic permeability. For example, it may be any of plating formed of a material other than Ni, paste of a material having a high magnetic permeability, a thin plate, and a thin magnetic sheet.
Further, in the example described with reference to FIGS. 2 to 4, the stepping motor 7 is a one-coil motor, and an example in which the stator 201 corresponding to the stepping motor 7 is applied has been described, but the stepping motor is not limited to the one-coil motor. .. For example, the stepping motor may be a two-coil motor.

1 ... Clock, 7 ... Stepping motor, 11 ... Wheel train, 51 ... Main plate, 82 ... Movement, 201 ... Stator, 201A ... Magnetic plate material, 201a ... Surface, 201b ... Surface, 201D, 201E, 201K, 201L, 201Q, 201T ... Groove, 202 ... Rotor, 203 ... Rotor through hole, 204 ... Notch, 205 ... Notch, 206, 207, 406, 407, 408, 409 ... Foreign matter layer, 201G, 201H ... Magnetic coupling, 207 ... Melt solidification part (foreign matter layer, non-magnetic melt part), 208 ... Magnetic core, 209 ... Coil, 210, 211 ... Narrow part, 305 ... V-shaped groove (groove part), 311 ... Chrome paste coating area, 324 ... Laser irradiation Device, 340 ... Press device (pressing device), R ... Magnetic path.

Claims (12)

A magnetic plate material for a stator in which a through hole for a rotor is formed and a magnetic path is formed around the through hole for a rotor,
A non-magnetic region provided around the through hole and generating a magnetic pole around the through hole by excitation by a coil is provided.
The non-magnetic region is fixed in the groove portion whose cross-sectional area is reduced from one surface side of the magnetic plate material toward the other surface side along the thickness direction, and the magnetic permeability of the magnetic plate material is increased. Stator with a foreign matter layer that also has low magnetic permeability. The stator according to claim 1, wherein the foreign matter layer is formed of a non-magnetic material or a resin. A claim that the bottom side of the groove portion does not reach the other surface of the magnetic plate material, and the bottom side of the groove portion has a magnetic coupling portion that does not have the foreign matter layer on the other surface side of the magnetic plate material. The stator according to claim 1 or 2. The stator according to any one of claims 1 to 3, wherein the foreign matter layer is a melt-solidified portion containing an element different from the constituent elements of the magnetic plate material. The stator according to claim 4, wherein the magnetic plate material contains a Ni—Fe alloy, and the melt-solidified portion contains chromium. Claims 1 to claim that the other surface of the magnetic plate material is a main plate surface facing the main plate when assembled to the main plate of the movement, and the one surface of the magnetic plate material is a train wheel surface. Item 5. The stator according to any one of Item 5. A stepping motor including the stator according to any one of claims 1 to 6 and a rotor arranged in the through hole. A watch movement including the stepping motor according to claim 7 and a train wheel for transmitting the power of the stepping motor. A timepiece comprising the timepiece movement according to claim 8. A magnetic plate material for a stator in which a through hole for a rotor is formed and a magnetic path is formed around the through hole for a rotor,
A non-magnetic region provided around the through hole and generating a magnetic pole around the through hole by excitation by a coil is provided.
A stator in which the non-magnetic region has a gap portion that divides a part of a magnetic path in the magnetic plate material and a metal-plated portion that connects the ends of the magnetic plate material located on both sides of the gap portion. The method for manufacturing a stator according to claim 10.
A gap portion that divides the magnetic path is formed in a part of the magnetic path of the magnetic plate material.
A method for manufacturing a stator, which forms a magnetic coupling portion that magnetically couples the ends of the magnetic plate material that sandwich the gap portion. The method for manufacturing a stator according to claim 11, wherein the magnetic coupling portion is formed by Ni plating.

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