JP2012098054A - Step motor for chronometric use - Google Patents

Abstract

PROBLEM TO BE SOLVED: To address the problems that pointers tend to be forced out of alignment by temperature changes, faster turning of the pointers invites an increase in power consumption, stepwise pointer movement in addition to continuous pointer movement is impossible, and any load that may be imposed is difficult to be compensated for.SOLUTION: A step motor for chronometric use includes a first motor which has a structure to cause a holding torque to work and which is so controlled that application of a drive pulse causes a first rotor to turn by a prescribed angle in a prescribed rotational direction and a second motor which has a structure to cause no holding torque to work and which is so controlled that application of a control pulse results in control to judge whether or not a second rotor is to be turned; and the two motors are so superposed one over the other in the axial direction thereof that the rotors of the two motors are magnetically coupled to generate an attracting force or a repulsive force in the rotational direction. This configuration results in the ability of the pointers to operate reliably even under load in addition to being resistant to temperature variations, smaller in power consumption and permitting stepwise driving.

Description

  The present invention relates to a step motor driven by a reference signal such as a crystal resonator, and more particularly to a timepiece step motor for continuously rotating a pointer.

Generally known electronic analog timepieces often use a step motor for timepieces that uses a two-pole rotor magnet as a motor for the driving source of the hands. By using such a motor, the hands are intermittent. Move the needle.
On the other hand, there has been a demand for a sweeping hand clock having a pointer rotated smoothly. In particular, a step motor must be used to realize a small, thin, and low power consumption watch. Therefore, a mechanism that converts the intermittent motion of the step motor into a continuous motion is required to perform sweep hand movement. ing. Until now, in order to perform a continuous drive using a step motor, the technique using a viscous fluid as a speed control mechanism is proposed.

  An example of a technology that uses a viscous fluid as a speed control mechanism is to construct a magnetic coupling that separates the rotating shaft by the engagement of a permanent magnet via a viscous body, and converts the movement of the second indicator hand for intermittent feed into smooth continuous rotation. (For example, refer to Patent Document 1).

  Details of the prior art disclosed in Patent Document 1 will be described with reference to the cross-sectional view of FIG.

  In FIG. 14, the rotational motion is transmitted to the fourth gear 102 from the rotor which is omitted. In this case, the No. 4 axle 105 is intermittent feed of one step and one second for one rotation per minute. Normally, the second hand is attached to the second hand shaft 111 directly connected to the fourth wheel shaft 105 to give a second instruction. However, in the conventional technique shown in Patent Document 1, the fourth wheel shaft 105 is separated and the magnetic force is passed through the viscous body 113. It is structured to be indirectly connected with a joint.

  Two permanent magnets 115 for driving are supported in a radial direction on a magnet receiver 114 directly connected to the fourth axle 105 and engaged with a driven magnet 116 by magnetic attraction. The driven magnet 116 is housed in such a manner that the viscous body 113 is immersed in a part of a center bearing 117 that is a bearing for receiving the second wheel axle 108 and is rotatable.

  A follower magnet 118 made of a permanent magnet is attached to one end of the second hand shaft 111, and the tip of the shaft is supported by a bearing ruby 120 that also serves as a storage lid for a driven magnet.

  The drive permanent magnet 115 arranged so as to rotate integrally with the fourth axle 105 in the radial direction of the driven magnet 116 is the same as the driven magnet 116 as it is due to the intermittent rotation of the train wheel by attracting engagement between the magnets. The driven magnet 116 cannot immediately follow due to the resistance of the viscous body 113.

  For example, in the case where the driving permanent magnet 115 is instantaneous intermittent feed once per second, the movement of the driven magnet 116 is more viscous than the attractive force and the viscosity of each magnet are balanced, that is, more viscous than the attractive force. At the time when the resistance becomes weak, the rotation starts little by little and tries to be stabilized while being attracted to the stop position of the driving permanent magnet 115 that has already advanced while moving smoothly.

However, at that time, the driving side has already started the next step, and the driven magnet 116 repeats a smooth movement while exhibiting a substantially constant follow-up delay with respect to the driving permanent magnet 115. Thereafter, if the drive side repeats intermittent rotation by a certain angle for a certain period of time, the driven magnet 116 and the follower magnet 118 attached to one end of the second hand shaft 111 integrally rotate smoothly at a substantially constant speed. Therefore, the second hand attached to the second hand shaft 111 is a sweep hand movement.

  As described above, as explained using the prior art disclosed in Patent Document 1, in the timepiece pointer mechanism using the intermittently rotating drive magnet, it is easy to make a smooth hand movement due to the liquid viscosity and the magnetic coupling mechanism. Reliable motion conversion is achieved with a simple structure.

Japanese Examined Patent Publication No. 56-47512 (page 2-3, FIG. 1)

  In the prior art disclosed in Patent Document 1, in order to perform smooth continuous rotation, the movement of the second hand is made smooth by configuring a magnetic coupling in which the rotation shaft is separated by the engagement of a permanent magnet through a viscous body 113. To convert to continuous rotation.

  However, the speed control means using the viscous material has a problem that the viscous resistance of the viscous material is likely to change due to a temperature change. The prior art shown in Patent Document 1 is also the same, and the viscous resistance of the viscous body 113 is likely to change. For this reason, there exists a big subject that a needle | hook deviation | shift will occur easily.

  Further, the viscous resistance of the viscous body has a characteristic that it increases in proportion to the speed. For this reason, there is a problem that it is difficult to rotate the second hand shaft at high speed in continuous hand movement. That is, it takes a long time to rotate the hands to correct the time. Such a characteristic of viscous resistance that increases in proportion to the speed has a problem that even if a certain amount of high speed driving is performed, power consumption for driving is immediately increased.

  Furthermore, the pointer display in the speed control means using the viscous material is only continuous hand movement, and the step operation cannot be performed. That is, it is not possible to realize a sweeping hand that makes a smooth movement and a step movement that moves every second, for example, with a viscous body and a single magnetic coupling mechanism.

  In the prior art disclosed in Patent Document 1, a follower magnet 118 made of a permanent magnet is attached to one end of the second hand shaft 111, and the follower magnet 118 rotates together by a magnetic attractive force generated between the follower magnet 116. Do. However, since the magnetic attraction force acting between the follower magnet 118 and the driven magnet 116 is constant, a load greater than the magnetic attraction force acting between the follower magnet 118 and the driven magnet 116 is applied to the second hand shaft 111. The following magnet 118 and the driven magnet 116 are slipped and cannot rotate together. Another problem is that load compensation cannot be performed because the slip does not change when the excitation on the drive side is strengthened.

  The object of the present invention is to solve the above problems. Even when temperature changes occur, the pointer is unlikely to shift, and high-speed rotation of the pointer can be achieved with low power consumption, so the time can be adjusted with high-speed and low power consumption. Therefore, it is possible to provide a display function for notifying that the low power consumption mode can be set or that the remaining battery level is low. Another object of the present invention is to provide a stepping motor for a continuous hand-operated timepiece that can perform excitation compensation to drive a pointer when a load is applied to compensate the load.

  In order to solve the above problems, the timepiece step motor of the present invention employs the following configuration.

  In a timepiece stepping motor having a first motor and a second motor, the first motor includes a first rotor, a first yoke having a rotor hole into which the first rotor is inserted, and the first motor. A first coil wound around one yoke, and the second motor includes a second rotor, a second yoke having a rotor hole into which the second rotor is inserted, and the second yoke. The first and second motors are arranged so that their rotors are magnetically coupled to each other and overlapped in the axial direction, and drive pulses are applied to the first coil. When the first rotor rotates and the second rotor rotates by generating an attractive force or a repulsive force with respect to the first rotor, a control pulse is applied to the second coil to The rotor is continuously rotated in a predetermined direction.

  Thereby, continuous hand operation is possible without using a viscous body, and a step motor for a continuous hand timepiece that is not affected by temperature changes can be obtained.

  The holding torque applied to the first rotor of the first motor may be larger than the holding torque applied to the second rotor of the second motor.

  When the second rotor tries to rotate by the electromagnetic force from the first motor, if the holding torque applied to the second rotor is smaller than the holding torque applied to the first rotor, the rotation control of the second rotor is performed. When performing, since it can control by the control energy only of the difference of the holding torque, the power consumption concerning control can be reduced.

  Around the rotor hole of the first yoke, a pair of slits or magnetic flux saturation portions provided for applying a driving torque to the first rotor by a magnetic field by the first coil, and a holding torque acting on the first rotor A pair of inner notches provided for the purpose may be provided, and the second yoke may not be provided with a slit, a magnetic flux saturation portion, and an inner notch.

  Thereby, it can be set as the stepping motor for continuous hand clocks which can drive low power consumption.

  The first yoke and the second yoke may be demagnetized via a gap or a nonmagnetic spacer.

  Thereby, a magnetic force works efficiently and it can be set as the stepping motor for continuous hand clocks with low power consumption.

  A first control circuit for generating a drive pulse for controlling the first motor; and a second control circuit for generating a control pulse for controlling the second motor. Control is performed so that a drive pulse having a pulse width shorter than one second is applied to the first coil, and the second control circuit is configured to apply the drive pulse before application of the drive pulse and when the first rotor rotates by application of the drive pulse. A control pulse for controlling whether or not the second rotor can be rotated may be applied to the second coil.

  As a result, it is possible to control whether continuous operation or step operation is performed, so that low power consumption can be achieved by switching to the low power consumption mode.

  The second control circuit may have a function of stopping the output of the control pulse.

Thereby, while being able to achieve low power consumption, it is possible to provide a caution display when the remaining battery level is low.

  The second control circuit may have a function of outputting a pulse that gives rotational torque to the second rotor.

  As a result, when a load is applied to the pointer and the pointer cannot be driven only by the magnetic force between the magnets, it is possible to reliably move the needle even in the case of a large load by generating a rotational torque.

  According to the present invention, since it is not necessary to use a viscous body, even when a temperature change occurs, it is difficult for the pointer to shift, and low power consumption can be achieved, and high-speed rotation of the pointer can be achieved with low power consumption. Therefore, the time can be corrected with high speed and low power consumption.

Furthermore, since step operation can be performed in addition to continuous operation, low power consumption mode can be achieved and a display function that notifies when the battery level is low can be achieved. it can.
In addition, when a load is applied, excitation can be performed and the load can be compensated for driving the pointer, so that stable driving can be performed even for a heavy load.

1 is a perspective view of a first embodiment of a timepiece stepping motor according to the present invention. It is a block diagram of the step motor control device for timepieces by this invention. It is a 1st drive circuit diagram of the step motor for timepieces by this invention. FIG. 6 is a second drive circuit diagram of the timepiece step motor according to the present invention. It is the drive pulse group of the step motor for timepieces by this invention, and a control pulse group. It is a figure explaining the 1st state of the step motor for timepieces by this invention. It is a figure explaining the 2nd state of the step motor for timepieces by this invention. It is a figure explaining the 3rd state of the step motor for timepieces by this invention. It is a figure explaining the 4th state of the step motor for timepieces by this invention. It is a figure explaining the 5th state of the step motor for timepieces by this invention. It is another drive pulse group of the step motor for timepieces by this invention, and a control pulse group. The drive pulse group and control pulse group explaining 2nd Embodiment of the step motor for timepieces by this invention. The drive pulse group and control pulse group explaining 3rd Embodiment of the step motor for timepieces by this invention. It is sectional drawing explaining the prior art shown in patent document 1. FIG.

The timepiece step motor of the present invention has a structure in which two first and second motors are stacked in the axial direction.
The two motors have a difference in holding torque. The first motor is a step motor that has a structure in which holding torque is applied and is controlled to rotate the first rotor by a predetermined angle in a predetermined rotation direction by applying a drive pulse.
The second motor has a structure in which the holding torque does not act, and whether or not the second rotor can rotate is controlled by applying a control pulse.
These two motors are overlapped in the axial direction so that the rotors are magnetically coupled to each other to generate an attractive force or a repulsive force in the rotational direction.

When the first rotor rotates by a predetermined angle, the magnetically coupled second rotor tries to rotate, but can be controlled from a state in which the rotation is limited by a control pulse to a state in which the rotation is permitted. In terms of concept, it is possible to control such that the force to be rotated is braked and released gradually. For this reason, the step motion of the first motor is a continuous rotational motion in the second motor.

  Thus, smooth continuous hand movement is realized by step-driving the first motor and controlling the second motor that rotates magnetically. The second motor that moves while being magnetically coupled to the first motor obtains rotational torque by the magnetic force received from the rotor of the first motor, and the rotational motion of the rotor of the second motor is The speed can be slowed down by a control pulse that excites the coil 19. For this reason, the rotation operation of the train wheel mechanism connected to the second motor can also be operated slowly, and the pointer can be continuously moved.

  Unlike the mechanism that converts the intermittent motion to the continuous motion using the conventionally known viscous material, the second motor can be directly controlled using the control pulse, so there is no influence of the temperature, and the pointer shift There is a feature that is difficult to occur. In addition, since the two motors have a difference in holding torque and the second motor can be structured such that the holding torque does not act, the control pulse is controlled according to the magnetic force from the first motor. Therefore, it is possible to set a control pulse with low power consumption.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the description, the drawing number is designated, but the drawings already explained should be referred to as appropriate. In the drawings, the same reference numerals are given to the same components, and duplicate descriptions are omitted.

  A first embodiment of a timepiece stepping motor will be described in detail with reference to FIG. FIG. 1 is a perspective view of a timepiece stepping motor according to the first embodiment, and is a perspective view in which a first motor and a second motor are disassembled in the axial direction.

[Description of Configuration of First Embodiment: FIG. 1]
In FIG. 1, 1 is a first motor, 3 is a second motor, 5 is a first rotor, 7 is a rotor hole, 9 is a first yoke, 11 is a first coil, and 13 is a second rotor. , 15 is a rotor hole, 17 is a second yoke, and 19 is a second coil. 21 is a magnetic flux saturation part, 23 is an inner notch. 25 is the fifth wheel, 27 is the fourth wheel, and 61 is the second hand.

  The first motor 1 is provided with a first yoke 9 and a first coil 11 for excitation, and the first yoke 9 and the first coil 11 are magnetically coupled to each other. A magnetic circuit is configured. The first yoke 9 has a rotor hole 7, and the first rotor 5 is rotatably disposed in the rotor hole 7.

  Around the rotor hole 7 of the first yoke 9, a pair of magnetic flux saturation portions 21 provided for applying a driving torque to the first rotor 5 by a magnetic field by the first coil 11, and a holding torque for the first rotor 5 and a pair of inner notches 23 provided for acting on 5.

  In addition, although a pair of magnetic flux saturation part 21 is a structure which provides a narrow part in the predetermined part of the rotor hole 7 of the 1st yoke 9, the same effect | action is acquired even if it provides a slit in this part. The slit can be constituted by an air gap or a nonmagnetic material.

The second motor 3 includes a second yoke 17 and a second coil 19 for exciting. The second yoke 17 and the second coil 19 are magnetically coupled to each other. A magnetic circuit is configured. The second yoke 17 has a rotor hole 15, and the second rotor 13 is rotatably disposed in the rotor hole 15.

The second yoke 17 of the second motor 3 is not provided with a magnetic flux saturation part and an inner notch. For this reason, the holding torque by the second yoke 17 can be substantially zero.
By doing so, since the control pulse applied to the second coil 19 may be a control pulse corresponding to the magnetic force from the first rotor 5, a control pulse with low power consumption can be set.
The structure around the first and second rotor holes 7 and 15 will be described later.

  As already described, in FIG. 1, the first motor 1 and the second motor 3 are disassembled vertically in the drawing, but the first rotor 5 and the second rotor 13 are coaxial. Is placed on top. And each is freely rotatable.

Although not shown, between the first motor 1 and the second motor 3, the positional relationship between the two is made correct by a gap or a nonmagnetic spacer, and both are demagnetized. Thereby, a magnetic force works efficiently and it can be set as the stepping motor for continuous hand clocks with low power consumption.
The fixing and positioning of the two stacked motors by the air gap and the nonmagnetic spacer are already known, and the description thereof will be omitted.

  The second rotor 13 is provided with a kana on its rotating shaft. A gear train mechanism such as a fifth gear 23 and a fourth gear 25 which are output gears is connected to the pinion, and a second indicator 61 is attached to the fourth gear 25. Note that the wheel train mechanism and the mechanism for holding the second hand 61 are omitted. Of course, the illustrated train wheel mechanism is an example.

[Description of Control Device of First Embodiment: FIG. 2]
Next, the outline of the control means for controlling the time step motor will be described. FIG. 2 is a block diagram showing a configuration of the timepiece step motor control apparatus of the present invention.

  As shown in FIG. 2, the control means is based on a pulse synthesizing circuit 31 that generates a reference pulse using a reference oscillation source such as a crystal oscillator 29, and various pulse signals output from the pulse synthesizing circuit 31. And a drive control circuit 33 for controlling the step motor. The drive control circuit 33 can be configured by a microcomputer or the like.

  The drive control circuit 33 has a function of supplying a drive pulse to the first coil 11 via the first control circuit 35. Also, it has a function of outputting a compensation pulse having a larger effective power than the drive pulse when the rotating body is not rotating.

  Further, the control pulse output is stopped after the drive pulse is output, and thereby, the continuous operation can be changed to the step operation, and the low power consumption mode can be set.

  In addition, since the frequency of the drive pulse can be increased in step operation, even a motor capable of sweep operation can be operated at high speed.

  The second coil 19 is controlled by the second drive circuit 37 connected to the drive control circuit 33.

The rotation detection circuit 39 connected to the drive control circuit 33 is supplied with a detection waveform that is a back electromotive voltage induced in the first coil 11 and the second coil 19. Rotation / non-rotation of the first rotor 5 and the second rotor 13 is determined by using a method such as determining the peak value level, determining a certain value or more, or capturing a phenomenon that the voltage value is reversed using the electromotive voltage. Can be done.

  In the rotation detection at this time, when a heavy load is applied to the needle and a change occurs in the detection waveform, which is a back electromotive voltage, a pulse output is applied to apply torque to the second rotor 13 to compensate the load. Can do.

[Description of Driving Circuit of First Embodiment: FIGS. 3 and 4]
Here, the first control circuit 35 and the second control circuit 37 described above will be described.
FIG. 3 is a diagram showing the configuration of the first control circuit 35 included in the control means described above, and FIG. 4 is a diagram showing the configuration of the second control circuit 37 included in the control means.

  As shown in FIG. 3, the first control circuit 35 connects an n-channel MOSFET 43a and a p-channel MOSFET 41a in series, connects an n-channel MOSFET 43b and a p-channel MOSFET 41b in series, and connects these series circuits in parallel. A bridge circuit configured as described above. The first coil 11 is connected so as to connect the connection midpoints of the n-channel MOSFET and the p-channel MOSFET of each series circuit.

  By controlling the control signal Pn1 of the n-channel MOSFET 43a, the control signal Pp1 of the p-channel MOSFET 41a, the control signal Pn2 of the n-channel MOSFET 43b, and the control signal Pp2 of the p-channel MOSFET 41b, the power supply supplies the first coil 11 of the step motor. It is possible to control the power supplied and change the direction of current flow.

  The second control circuit 37 shown in FIG. 4 has the same configuration as the first control circuit 35 shown in FIG. In other words, an n-channel MOSFET 47a and a p-channel MOSFET 45a are connected in series, an n-channel MOSFET 47b and a p-channel MOSFET 45b are connected in series, and a bridge circuit configured by connecting these series circuits in parallel is provided. The second coil 19 is connected so as to connect the connection midpoints of the n-channel MOSFET and the p-channel MOSFET of each series circuit.

  By controlling the control signal Pn1 of the n-channel MOSFET 47a, the control signal Pp3 of the p-channel MOSFET 45a, the control signal Pn2 of the n-channel MOSFET 47b, and the control signal Pp4 of the p-channel MOSFET 45b, the power source supplies the second coil 19 of the step motor. It is possible to control the power supplied and change the direction of current flow.

[Explanation of Drive Pulse and Control Pulse Group in First Embodiment: FIG. 5]
Next, the control pulse group and drive pulse of the timepiece step motor will be described.
The drive pulse 55 is a pulse that is output when rotational torque is applied to the first rotor 5, and continuously outputs pulses having an arbitrary duty at intervals of about 500 μs, and has a pulse width of several milliseconds in total. ing.

  For example, if the full pulse is 2.5 msec, a pulse of about 0.5 msec is output five times continuously. If the duty is a half pulse, a pulse of about 0.25 msec, which is half of a pulse of about 0.5 msec, is output, and then there is a non-output period of about 0.25 msec. A pulse of .25 ms is output, and then the non-output period of about 0.25 ms is repeated until 2.5 ms.

  The control pulse groups 57 and 59 are pulses that are output when the rotation of the second rotor 13 is controlled. The control pulse groups 57 and 59 include a first control pulse 57 and a second control pulse 59. The first control pulse 57 is a pulse having a width of several milliseconds by continuously outputting a plurality of pulses of about 500 μs, and the duty of each of the plurality of pulses constituting the first control pulse 57 is arbitrarily set. Is possible.

  The second control pulse 59 is composed of a plurality of pulse groups that continuously output a plurality of pulses of about 500 μs, and the interval a of each pulse group is constant. It is also possible to set so that the duty gradually decreases.

  The first to fifth states shown in FIG. 5 indicate the state of rotation of the rotor of the motor. Each state will be described in turn.

[Description of the first state in the first embodiment: FIGS. 1, 5, and 6]
Next, the operation of the timepiece step motor will be described with reference to FIGS. First, the first state shown in FIG. 5 will be described.
FIG. 6 is a plan view for explaining the state of the motor. FIG. 6A is an enlarged view of the rotor hole 7 portion showing the first state of the first motor 1, and FIG. FIG. 6 is an enlarged view of a rotor hole 15 portion showing a first state of the motor 3 of FIG.

As shown in FIG. 6, the first yoke 9 and the second yoke 17 are disposed with a predetermined angle. The angle of the second yoke 17 with respect to the first yoke 9 is an angle formed by the electromagnetic stable direction acting on the first rotor 5 by the first yoke 9 and the stationary stable direction of the first rotor 5 ( In this example, θ).
The stationary stable direction of the second rotor 13 is substantially coincident with the stationary stable direction of the first rotor 5 (first stationary stable direction 51 described later). The stationary stable direction of the first rotor 5 is determined by an inner notch 23 provided in the first yoke 9, and is inclined by θ from an electromagnetic stable direction (an electromagnetic stable direction 49 described later) by the first yoke 9. Yes.

  Thus, the first yoke 9 and the second yoke 17 are installed to have a predetermined angle (θ in this example), but this angle varies depending on the size and shape of the yoke and the rotor. Although the angle cannot be generally specified, it is, for example, 58 degrees.

  As shown in FIG. 6A, a drive torque is applied to the first rotor 5 by the first coil 11 around the rotor hole 7 of the first yoke 9 constituting the first motor 1. There is a pair of magnetic flux saturation portions 21 provided in the electromagnetic field, and the stable direction by the electromagnetic force that can be applied to the first rotor 5 by exciting the first coil 11 is defined as an electromagnetic stable direction 49, and the holding torque is A pair of inner notches 23 provided for acting on the first rotor 5 are provided.

  In the first state, as shown in FIG. 5, the drive pulse 55, the first control pulse 57, and the second control pulse 59 are not output together.

  Since the first motor 1 does not excite the first coil 11 as shown in FIG. 6A, only the holding torque from the first yoke 9 acts on the first rotor 5. Due to the holding torque, the N pole and S pole directions are stationary in the first stationary stable direction 51 inclined by θ from the electromagnetic stable direction 49.

As already described, the magnetic flux saturation part and the inner notch are not provided around the rotor hole 15 of the second yoke 17 constituting the second motor 3.
Therefore, as shown in FIG. 6B, the second motor 13 is held by the electromagnetic force from the first rotor 5, so that the N pole and the S pole are the first rotor. It is in a state in which it is directed in the opposite direction to the N-pole and S-pole of No. 5, and is stationary in a second stationary stable direction 53 that substantially coincides with the first stationary stable direction 51.

[Description of Second State in First Embodiment: FIGS. 1, 5, and 7]
Next, the second state shown in FIG. 5 will be described with reference to FIGS.
FIG. 7 is a plan view for explaining the state of the motor, and is a plan view seen from the same direction as FIG. FIG. 7A is an enlarged view of the rotor hole 7 portion showing the second state of the first motor 1, and FIG. 7B is a rotor hole 15 showing the second state diagram of the second motor 3. It is an enlarged view of a part.

  In the second state, as shown in FIG. 5, the drive pulse 55 is not output and the first control pulse 57 is output.

  Since the first motor 1 does not excite the first coil 11 as shown in FIG. 7A, only the holding torque from the first yoke 9 acts on the first rotor 5. The first rotor 5 is in a stationary stable state in a first stationary stable direction 51 in which the N and S pole directions are inclined by θ from the electromagnetic stable direction 49 by the holding torque (this state is shown in FIG. It is the same as the state shown in a).

  Since the first control pulse 57 is output to the second motor 3, the second coil 19 is in an excited state, and as shown in FIG. The portion of the second rotor 13 facing the S pole is excited to the S pole. The second yoke 17 is excited with the N pole and the S pole in a second excitation stable direction 55 that is substantially coincident with the second stationary stability direction 53. In FIG. 7B, the second stationary stable direction 53 and the second excitation stable direction 55 are shown in parallel to make the drawing easier to see.

At this time, the N pole and the S pole of the second rotor 13 face the second stationary stability direction 53. However, in the second state, rotational torque acts on the second rotor 13 even when excited. do not do.
In addition, after the rotation starts, if the N pole and S pole of the second rotor 13 are before reaching the second stationary stable direction 53, the magnetic poles of the second rotor are attracted in the second stationary stable direction 53. Thus, if the N pole and S pole of the second rotor 13 are slightly past the second stationary stable direction 53, a torque acting as a brake action is applied and the second rotor 13 is actuated. Therefore, if the pulse of the second state is output at a constant period, the position of the first rotor is the next third position. In this state, it is possible to make the positions substantially the same, so that the torque acting from the first rotor can be made substantially equal.

[Description of Third State in First Embodiment: FIGS. 1, 5, and 8]
Next, the third state shown in FIG. 5 will be described with reference to FIGS. 1, 5, and 8.
FIG. 8 is a plan view for explaining the state of the motor, and is a plan view seen from the same direction as FIGS. 6 and 7. FIG. 8A is an enlarged view of the rotor hole 7 portion showing the third state of the first motor 1, and FIG. 8B is a rotor hole 15 showing the third state diagram of the second motor 3. It is an enlarged view of a part.

  In the third state, as shown in FIG. 5, the drive pulse 55 is applied to the first coil 11 of the first motor 1, and the first coil 19 of the second motor 3 is applied to the first coil 11. A control pulse 57 is applied.

As shown in FIG. 8A and FIG. 8B, the second yoke 17 is made of N of the second rotor 13.
Excitation is performed by the first control pulse 57 so that the position facing the pole becomes the S pole and the position facing the S pole of the second rotor 13 becomes the N pole. Then, the first yoke 9 flows a drive pulse 55 so that the right side of the rotor hole 7 is excited to the N pole on the right side and the S pole on the left side, so that the N pole of the first yoke 9 and the first rotor The N pole of 5 repels, the S pole of the first yoke 9 and the S pole of the first rotor 5 repel, and the first rotor 5 rotates counterclockwise in the drawing (indicated by the arrow in the drawing). Receiving torque and starting rotation, the state shown in FIG.

[Description of Fourth State in First Embodiment: FIGS. 1, 5, and 9]
Next, the 4th state shown in FIG. 5 is demonstrated using FIG.1, FIG5 and FIG.9.
FIG. 9 is a plan view for explaining the state of the motor, and is a plan view seen from the same direction as FIGS. FIG. 9A is an enlarged view of the rotor hole 7 portion showing the fourth state of the first motor 1, and FIG. 9B is a rotor hole 15 showing the fourth state diagram of the second motor 3. It is an enlarged view of a part.

  In the fourth state, as shown in FIG. 5, the drive pulse 55 is not applied to the first coil 11 of the first motor 1, and the second coil 19 of the second motor 3 has the second state. The control pulse 59 is applied.

  As shown in FIG. 9A, the first motor 1 does not excite the first coil 11, and the first rotor 5 is in the same state as shown in FIG. 8A.

In the second motor 3, as shown in FIG. 9B, the rotor 13 of the second motor 3 tries to rotate as the first rotor 5 of the first motor 1 rotates. At this time, since the second control pulse 59 is applied, the second yoke 17 can be excited to excite the N pole and the S pole around the rotor hole 15, and the second control pulse 59 is a pulse. Since a narrow pulse is output at a constant interval a, the time during which torque is applied to the second rotor 13 by the excitation by the second control pulse 59 and the time during which no torque is applied to the second rotor 13 are alternated. Can be made.
For this reason, the second rotor 13 is excited by the second control pulse 59, and the torque applied during the time during which the torque is applied is weak, and the torque applied from the first rotor 5 during the time during which the torque is applied. The second rotor 13 receives a force to rotate counterclockwise in the drawing (indicated by the arrow in the drawing).

[Description of Fifth State in First Embodiment: FIGS. 1, 5, and 10]
Next, the 5th state shown in FIG. 5 is demonstrated using FIG.1, FIG5 and FIG.10.
FIG. 10 is a plan view for explaining the state of the motor, and is a plan view seen from the same direction as FIGS. FIG. 10A is an enlarged view of the rotor hole 7 portion showing the fifth state of the first motor 1, and FIG. 10B is a rotor hole 15 showing the fifth state diagram of the second motor 3. It is an enlarged view of a part.

  In the fifth state, as shown in FIG. 5, as in the first state, the drive pulse 55, the first control pulse 57, and the second control pulse 59 are not output.

  As shown in FIG. 10 (a), the first motor 1 receives a holding torque acting from the first yoke 9 in a state where the first rotor 5 is excited and the N pole is directed leftward in the drawing. It rotates in the counterclockwise direction of the drawing (shown by the arrow in the drawing), and rotates so that the magnetic pole faces in the first stationary stable direction 51.

As shown in FIG. 10B, the second motor 3 applies the second control pulse 59 that gradually weakens the excitation, as described in the fourth state. The torque to be held decreases, and therefore, the influence of the rotational torque received from the first rotor 5 of the first motor 1 increases, so that the rotation gradually starts counterclockwise in the drawing (indicated by the arrow in the drawing). Then, the magnetic poles of the second rotor 13 face in the stationary stable direction.

As described above, the second rotor 13 of the second motor 3 obtains rotational torque by the magnetic force received from the first rotor 5 of the first motor 1, and the rotational motion of the second rotor 13 is Since the speed can be slowed by the control for exciting the second coil 19 of the second motor 3, the rotation operation of the gear train mechanism (5th gear, 4th gear) connected to the second rotor 13 is also slow. The second hand 61 can be moved continuously.
In addition, after the fifth state, the rotation returns to the first state, and the polarity of the pulse changes, so that continuous rotation can be continued.

[Explanation of another control pulse group in the first embodiment: FIG. 11]
Next, another control pulse group of the timepiece step motor will be described mainly with reference to FIG. The drive pulse is similar to the example already described.

The control pulse group includes a first control pulse 57 and a third control pulse 63.
As described above, the first control pulse 57 is a pulse having a width of several milliseconds by continuously outputting a plurality of pulses of about 500 μs, and the duty of each of the plurality of pulses can be arbitrarily set.

The third control pulse 63 is composed of a plurality of pulse groups that continuously output a plurality of pulses of about 500 μs, and the interval between each pulse group is arbitrarily set. The first pulse group and the second pulse group When the interval between the first pulse group and the second pulse group and the third pulse group is a2,
a1 <a2
Have a relationship. Thus, the relationship between the nth pulse interval and the (n + 1) th pulse interval is
an <an + 1
So that the interval gradually increases.
In the example illustrated in FIG. 11, the third control pulse 63 illustrates six pulse groups.

  As a result, even when the duty of the pulses constituting the pulse group cannot be lowered, the torque applied to the second rotor 13 can be optimally controlled by widening the pulse group interval, and the control to rotate slowly becomes possible. .

[Explanation of drive pulse and control pulse when performing step hand movement: FIG. 12]
Next, as a second embodiment of the timepiece stepping motor, the case of stepping will be described with reference to FIG.
In the configuration using the previously known viscous material that has already been described, stepping cannot be performed, but in this embodiment, it is easily realized by turning off the control pulse for controlling the second motor 3. it can.

  As shown in FIG. 12, in order to perform the step operation, the second rotor 13 obtains the rotational torque only by the magnetic force from the first rotor 5 by turning off the control pulse. Similarly to the first rotor 5, the second rotor 13 can be stepped.

Since the wheel train mechanism is connected to the second rotor 13, the second hand 61 can be stepped. At this time, since the control pulse is OFF, it can be used as a low power consumption mode. For example, it is possible to automatically switch to step operation when the remaining battery level is low and to function as a mode for notifying the user of the low battery level.

In addition, if the time interval f during step operation is 1 second, normal step operation display is performed. However, high-speed operation can also be performed by performing this at short time intervals.
This is convenient because the hands can be quickly set to a predetermined time even when the time is set.

  The above control can be performed by the drive control circuit 33 shown in FIG. As already described, since the control circuit 33 can be configured by a microcomputer or the like, it can be easily implemented by a control program.

[Explanatory diagram of drive pulse and control pulse when performing load compensation: FIG. 13]
Next, as a third embodiment of the timepiece step motor, when a heavy load is applied to the hands and the hands cannot be driven only by the magnetic force between the magnets, a remaining force for surely moving the hands is required. This will be described with reference to FIG.

When a load is applied to the pointer, a control pulse is applied so that the second rotor 13 generates a rotational torque.
In FIG. 13, the drive pulse 55 is the same as before. When a load is applied to the pointer and rotation of the second rotor 13 is difficult, a control pulse group 65 having a polarity opposite to that of the previous control pulse is output. Thus, the second rotor 13 can obtain a large rotational torque, and even if a heavy load is applied to the pointer, it can be moved.

  Such a large load applied to the pointer is generated, for example, when the calendar mechanism is driven once a day. Whether or not a load is applied can be determined by detecting the presence or absence of a front waveform and a back waveform as usual in the back electromotive current waveform induced in the first coil 11. Even in such a case, the pointer can be driven accurately. It can be performed by the drive control circuit 33 shown in FIG.

  The step motor for a timepiece of the present invention is suitable for a timepiece that is installed in a place where the temperature change in the usage environment is large, because even if a temperature change occurs, it is difficult for the pointer to shift.

DESCRIPTION OF SYMBOLS 1 1st motor 3 2nd motor 5 1st rotor 7, 15 Rotor hole 9 1st yoke 11 1st coil 13 2nd rotor 17 2nd yoke 19 2nd coil 21 Magnetic saturation part 23 Notch 25 5th gear 27 4th gear 29 Crystal resonator 31 Pulse synthesis circuit 33 Drive control circuit 35 First drive circuit 37 Second drive circuit 39 Rotation detection circuit 41a, 41b p-channel MOSFET
43a, 43b n-channel MOSFET
45a, 45b p-channel MOSFET
47a, 47b n-channel MOSFET
49 Electromagnetic stable direction 51 First stationary stable direction 53 Second stationary stable direction 55 Drive pulse 57 Control pulse 59 Second control pulse 61 Second pointer 63 Third control pulse

Claims (7)

In a timepiece stepping motor having a first motor and a second motor,
The first motor includes a first rotor, a first yoke having a rotor hole into which the first rotor is inserted, and a first coil wound around the first yoke,
The second motor includes a second rotor, a second yoke having a rotor hole into which the second rotor is inserted, and a second coil wound around the second yoke,
The first and second motors are arranged so that their rotors are magnetically coupled to each other and overlap in the axial direction,
When the first rotor rotates by applying a driving pulse to the first coil and the second rotor rotates by generating an attractive force or a repulsive force with respect to the first rotor, the second rotor A step motor for a timepiece characterized in that the second rotor is continuously rotated in a predetermined direction by applying a control pulse to the coil.   2. The timepiece stepping motor according to claim 1, wherein a holding torque applied to the first rotor of the first motor is larger than a holding torque applied to the second rotor of the second motor. . Around the rotor hole of the first yoke, a pair of slits or magnetic flux saturation portions provided for applying a driving torque to the first rotor by a magnetic field generated by the first coil, and a holding torque are provided to the first yoke. A pair of inner notches provided to act on the rotor of the
The timepiece stepping motor according to claim 2, wherein the second yoke is not provided with a slit, a magnetic flux saturation portion, and an inner notch.   4. The timepiece stepping motor according to claim 1, wherein the first yoke and the second yoke are demagnetized through a gap or a non-magnetic spacer. 5. . A first control circuit for generating the drive pulse for controlling the first motor; and a second control circuit for generating the control pulse for controlling the second motor;
The first control circuit performs control so that the driving pulse having a pulse width shorter than 1 second is applied to the first coil;
The second control circuit outputs a control pulse for controlling whether or not the second rotor can be rotated before the driving pulse is applied and when the first rotor is rotated by the application of the driving pulse. 5. The timepiece stepping motor according to claim 1, wherein the stepping motor is applied to two coils.   6. The time step motor according to claim 5, wherein the second control circuit has a function of stopping output of the control pulse. 6. The timepiece stepping motor according to claim 5, wherein the second control circuit has a function of outputting a pulse that gives rotational torque to the second rotor.

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