JP3468011B2 - Startup control method for linear vibration motor - Google Patents

Startup control method for linear vibration motor

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Publication number
JP3468011B2
JP3468011B2 JP04123997A JP4123997A JP3468011B2 JP 3468011 B2 JP3468011 B2 JP 3468011B2 JP 04123997 A JP04123997 A JP 04123997A JP 4123997 A JP4123997 A JP 4123997A JP 3468011 B2 JP3468011 B2 JP 3468011B2
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Prior art keywords
amplitude
mover
output
electromagnet
coil
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JP04123997A
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Japanese (ja)
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JPH10243688A (en
Inventor
康夫 伊吹
多喜夫 前川
英俊 天谷
豊勝 岡本
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松下電工株式会社
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Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a starting control method for starting a linear vibration motor that generates reciprocating vibration with a linear motor. 2. Description of the Related Art Japanese Patent Application Laid-Open No. 2-52692 discloses that a linear motor is used as a source of reciprocating vibration. This linear vibration motor used as a drive source of a reciprocating electric shaver is composed of a movable element composed of a rod-shaped permanent magnet,
It is formed as a single-phase synchronous motor consisting of a stator with a coil wound around each piece of a U-shaped iron core, and supplies a DC voltage of twice the AC frequency to the coil by a full-wave rectifier circuit, The mover is reciprocating. In this case, a strong electromagnetic force is required to reciprocate the movable element to generate vibration. However, the movable element is configured as a spring vibration system by supporting the spring, and the natural vibration of the spring vibration system is set. If driving is performed at a frequency corresponding to the number, the energy required for driving can be reduced. However, when such a driving is performed, the amplitude of the reciprocating vibration is not stable under load. have. [0004] For this purpose, a stator comprising an electromagnet or a permanent magnet, a movable element provided with a permanent magnet or an electromagnet and supported by a spring, and at least one of displacement, velocity and acceleration of the movable element are detected. There is provided an apparatus including a detection unit and a control unit that controls power supplied to a coil of the electromagnet in accordance with an output of the detection unit. In this method, even if the amplitude changes for some reason, the amplitude change can be detected by the detecting means for detecting at least one of displacement, speed, and acceleration of the mover, and the amplitude change can be detected. By the appropriate power supply, the amplitude can be made constant, and reciprocating vibration with a stable amplitude can be reliably obtained. By the way, in the above linear vibration motor,
When control according to the output of the detection means cannot be performed,
That is, at the time of start-up, the current supply to the coil of the electromagnet by the PWM control or the like is operated with the maximum output pulse as shown in FIG. It was going to shift to control. In this case, an overrun in which the amplitude of the mover exceeds the specified amplitude S1 often occurs and overloads the components of the linear vibration motor. Also, if the maximum output pulse is given too much, the peak current of the current will increase too much and the load on the power supply and the driving element will increase. SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art, and it is an object of the present invention to provide a start-up control method for a linear vibration motor that can start up properly. . SUMMARY OF THE INVENTION The present invention provides a stator comprising an electromagnet or a permanent magnet, a movable element having a permanent magnet or an electromagnet and supported by a spring, a displacement and a velocity of the movable element. A start-up control method for a linear vibration motor, comprising: a detection unit that detects at least one of accelerations; and a control unit that controls power supplied to a coil of an electromagnet in accordance with an output of the detection unit. Is characterized by minimizing the output pulse at the initial stage of supply to the controller and sequentially increasing the output pulse from the previous output to increase the amplitude of the mover to the specified amplitude. Since the output is gradually increased, there is no possibility of mechanical overload or electrical overload such as overrun. At this time, if the rate at which the output pulse is made larger than the previous output at the time when the amplitude of the mover reaches an amplitude slightly smaller than the specified amplitude is reduced, overrun can be reliably prevented. The initial output pulse supplied to the coil is set to the minimum value, the output pulse is sequentially increased from the previous output to increase the amplitude of the mover, and when the amplitude reaches a predetermined amplitude smaller than the specified amplitude, the output of the detection means is output. The control may be shifted to the normal operation mode in which the power supplied to the coil of the electromagnet is controlled accordingly. [0010] Further, the output pulse in the initial stage of starting supplied to the coil is minimized, the output pulse is sequentially increased from the previous output to increase the amplitude of the mover, and the amplitude is detected by the detection means. When the amplitude reaches the allowable amplitude, a transition may be made to a normal operation mode in which the power supplied to the coil of the electromagnet is controlled in accordance with the output of the detection means. Further, the output pulse at the initial stage of starting supplied to the coil is minimized, the output pulse is sequentially increased from the previous output to increase the amplitude of the mover, and the amplitude is detected by the detection means. After the time when the amplitude reaches the possible amplitude and until the amplitude of the mover reaches the specified amplitude, the mode is shifted to the normal operation mode in which the power supplied to the coil of the electromagnet is controlled according to the output of the detection means. You may. In any case, the first output pulse or the first few pulses at the beginning of the startup are set to the maximum output, and then the output pulses are sequentially increased from the minimum value, so that the time required for the startup becomes longer. It won't pass. DESCRIPTION OF THE PREFERRED EMBODIMENTS First, an example of the structure of a linear vibration motor will be described. FIGS. 6 and 7 show a linear vibration motor for a reciprocating electric shaver. Child 2 (two movable elements 21 and 2 in the figure)
2) and a frame 3. The stator 1 includes an E-shaped yoke 10 in which a sintered body of a magnetic material or an iron plate of a magnetic material is laminated,
And a coil 12 wound on a central piece of the yoke. Pins 12 project from both end surfaces of the yoke 10, respectively. The frame 3 to which the stator 1 is fixed is provided between the lower portions of the ends of the pair of side plates 30, 30, respectively.
The stator 1 is fixed to the frame 3 by welding or caulking with the pin 12 of the stator 1 fitted in a fixing groove 32 formed in the side plate 30. As shown in FIG. 7, the two types of movers 21 and 22 each have a reinforcing plate 25 made of a non-magnetic metal plate and a back yoke 26 on the lower surfaces of driven members 23 made of synthetic resin. The driven member 23 of the mover 21 has a planar shape formed in a square shape, and includes a reinforcing plate 25, a back yoke 26, and a permanent magnet 2.
0 is provided on each lower surface of both side pieces of the driven body 23,
The reinforcing plates 25 on both sides are formed integrally.
The reinforcing plate 25 is integrated with the driven body 23 by insert molding (outsert molding). In the figure, reference numeral 24 denotes a connecting portion provided integrally with the driven body 23 and connected to the inner blade of the reciprocating electric shaver. The two movers 21 and 22 are connected at both ends to the frame 3 via leaf springs 4 and 4. The leaf spring 4 here is formed by punching from a metal plate 4 ′, and a support plate 40 is attached to a fixed portion to the frame 3, and a connecting plate 43 is attached to a fixed portion to the movers 21 and 22, respectively. The center plate spring portion 41 connected to the mover 22 and a pair of left and right plate spring portions 42, 42 connected to the mover 21 are integrally connected at a portion of the support plate 40. 40 are fixed to both ends of the frame 3 by welding or the like, and each connecting plate 43 is fixed to the movable element 2.
When fixed to the ends of the reinforcing plates 25 by welding or the like, the two movers 21 and 22 are suspended from the frame 3 and are placed in the mover 21 having a square shape in plan view. The connecting portion 24 of the mover 22 is located. Also,
Between the spring receiving portions 26, 26 on the inner surface of the mover 21 and the spring receiving portions 27, 27 of the connecting portion 24 of the mover 22, a pair of compression coil springs is formed in the reciprocating direction of the movers 21, 22. Spring members 28, 28 are provided. In the linear vibration motor constructed as described above, the permanent magnet 20 provided on the mover 2 is vertically opposed to the stator 1 via a predetermined gap, and the reciprocating direction of the mover 2 As shown in FIG. 4, according to the direction of the current flowing through the coil 11 of the stator 1, the plate spring 4 moves left and right while bending the leaf spring 4. By switching the direction at an appropriate timing, the reciprocating vibration of the mover 2 can be performed. Here, the arrangement of the magnetic poles of the permanent magnet 20 provided on the mover 21 and the permanent magnet 2 provided on the mover 22
Since the arrangement of the magnetic poles of 0 is reversed, both movers 2
Reciprocal vibrations of phases 1 and 22 differ by 180 °. At this time, since the spring members 28, 28 are compressed and expanded, the spring system shown in FIG. 6 is constituted by the leaf spring 4 and the spring member 28 (strictly, a spring constant component due to magnetic attraction is further added). ing. In vibrating a vibration system having such a spring system, it is necessary to vibrate in synchronization with the natural frequency of the vibration system, that is, to achieve a resonance state in order to achieve stable vibration and drive energy. Therefore, in order to perform such a drive, a magnet for sensing 29 whose magnetic poles are arranged in the reciprocating direction of the mover 2 is attached to the mover 21 and provided on the frame 3 in order to perform such driving. The sensor 39 made of the sensing winding shown in FIG. 4 is attached to the mounting portion 34, and the control output unit 5 controls the coil 11 based on the current (voltage) induced in the sensor 39 due to the vibration of the mover 21. To control the current flowing through it. That is, as shown in FIG. 3, the voltage of the current induced in the sensor 39 changes in accordance with the magnitude and position of the movable element 2, the speed of vibration, the direction of vibration, and the like.
That is, when the mover 2 reaches one end of the amplitude of the reciprocating motion, the output of the sensor 39 becomes zero because the movement of the magnet 29 stops and the magnetic flux does not change. 2 and the output voltage of the sensor 39 also becomes maximum. Therefore, if the maximum voltage is detected, the maximum speed of the mover 2 can be detected, and the above-mentioned zero point can be detected as the movement direction reversal point (dead point arrival point). Can be detected. FIG. 8 shows an example. Although the output voltage of the sensor 39 changes in a sine curve, the output voltage is amplified by an amplifier circuit 51, converted into a digital value by an A / D converter circuit 52, and a predetermined time (for example, t) elapses from zero. The maximum speed at the center of the amplitude of the mover 2 can be detected by detecting the subsequent voltage or detecting the maximum voltage of the output voltage from zero to zero. Can be detected from the point in time at which the current direction changes, and the direction in which the current flows varies depending on whether the moving direction of the mover 2 (magnet 29) is a reciprocating motion. It is possible to detect which stroke of the reciprocating motion the mover 2 is in. Here, from the detected speed of the mover 2, when the control output unit 5 detects, for example, a decrease in the amplitude due to an increase in the load, the control output unit 5 increases the drive current amount (the energizing time T and the maximum current value in the illustrated example). By doing so, the amplitude is maintained at a required value. In the illustrated example, the drive current amount is controlled by PWM control, and the current amount outputs a PWM pulse width stored in advance for the detected speed. Since the speed, the displacement, and the acceleration are correlated, the displacement or the acceleration may be detected instead of the speed. Further, by supplying a current in a direction corresponding to the detected moving direction, it is possible to prevent a situation in which the drive current becomes a brake. Further, by supplying a current at a timing of a predetermined time t from the detected movement direction reversal time t1, the required amount of current is suppressed by effectively utilizing the movement of the spring system to drive the mover 2. In other words, if a current for driving in the reverse direction is applied to the coil 11 before the reversal of the moving direction, the vibration will be braked, and the current in the moving direction will be applied after the mover exceeds the center point of the amplitude. Since the driving force due to the repulsive force of the spring system compressed by the vibration of the mover 2 is already weakened when the coil 11 is added, the synergistic force between the driving by the electromagnetic force and the driving force by the spring system is reduced. I can't get it. For this purpose, the start timing of the current supply to the coil 11 is set within the time from the point of reversal of the moving direction to the center of the amplitude. The point at which the amplitude reaches the center can be detected as the point at which the output of the sensor 39 becomes maximum. Here, the time t may be a value adjusted according to the detected speed or acceleration of the mover 2. FIG. 8 shows an example of a drive circuit for the coil 11 of the stator 1. Four FET type switching elements Q1 to Q
By switching on the switching elements Q1 and Q3 at the same time and simultaneously turning on the switching elements Q2 and Q4 in the drive block 53 composed of the drive block 4, the direction of the current flowing through the coil 11 is switched to reciprocate the movable element 2. Action. Incidentally, in the above-described drive control, it is not always necessary to detect the moving direction and the point of time when the moving direction is reversed. Since the moving direction of the mover 2 is known from the applied drive current, the direction of the next drive current may be sequentially switched, and the current is started at a required period since the current is synchronized with the natural frequency. That is because it is good. However, if the above control according to these detections is also performed, even if a temporary stop occurs due to overload, current can flow in an appropriate direction, and
The drive current is always appropriately applied to the coil 11 with respect to the variation of the natural frequency due to the individual difference of the mass of the mover 2 and the spring constant of the spring system. It converges to a number and vibrates at a constant amplitude. As a detecting means, a combination of a sensing magnet 29 capable of detecting all of the moving direction, the reversal time of the moving direction and the position (velocity or acceleration) and a sensor 39 comprising a sensing winding is used.
Although the speed is detected from the maximum value (absolute value) of the output, the speed may be detected from the time interval at which the current (voltage) becomes zero. The zero point can reliably detect the reversal point of the moving direction without being affected by variations in the magnetic force of the magnet 29 and variations in the gap between the magnet 29 and the sensor 39. The speed of the mover 2 can be detected more accurately from the time interval. In addition, for example, a combination of a sensing magnet 29 and a magnetically sensitive element, a slit plate 60 attached to the mover 2 shown in FIGS. 6 and 7, and a photo sensor for detecting the slit of the slit plate 60 38 mag,
It can be used according to the detection target. However, a non-contact type which does not hinder the vibration of the mover 2 is desirable. In the linear vibration motor configured as described above, control according to the detection result of the detection means cannot be used at the time of starting as described above. For this reason, at the time of startup, the startup is performed according to a startup procedure preset in the startup setting unit 50 shown in FIG. This activation is shown in FIG.
As shown in (1), the output pulse in the initial stage of startup supplied to the coil 11 of the electromagnet 1 is minimized, and then the output pulse is sequentially increased from the previous output to increase the amplitude of the mover. Is shifted to the normal operation mode according to the output of (1). At this time, if the output pulse is made larger than the previous output until the time when the amplitude of the mover 2 reaches the specified amplitude S1 as shown in FIG. 1A, as shown by a broken line from the point a in the figure. In addition, since an overrun is likely to occur, although slightly, an output pulse is pre-output at the time point b when the amplitude of the mover 2 reaches an amplitude S3 slightly smaller than the specified amplitude S1, as shown by B in FIG. If the rate of increase is reduced and the operation is shifted to the normal operation mode when reaching the point c in the figure, it is possible to smoothly connect to the normal operation mode in which the vibration of the specified amplitude S1 is performed. At the time point b, the operation may be shifted to the normal operation mode. In this case, the amplitude reaches the specified amplitude S1 at the point e. Instead of the time point b, any time point f or a point after the time point f when the detecting means reaches the amplitude value S2 at which the amplitude of the mover 2 can be directly or indirectly detected, and until the specified amplitude S1 is reached. At time h (t '),
The mode may be shifted to the normal operation mode. g and i indicate the time points at which the amplitude reaches the specified amplitude S1, respectively. By the way, if the first output pulse in the early stage of the start-up is small, the time required for the start-up is inevitably long. Therefore, as shown by C in FIG. If the output pulse is sequentially increased from the minimum value,
As shown by j in FIG.
The time required for activation can be shortened. As described above, in the present invention, the initial output pulse supplied to the coil is minimized, the output pulse is sequentially increased from the previous output, and the amplitude of the mover is increased to the specified amplitude. Since the output is gradually increased, the life of the linear vibration motor can be maintained longer without falling into mechanical overload or electrical overload such as overrun. In addition, since the drive power is gradually increased from the start of the start and finally the maximum power is supplied, the start can be performed even when the maximum load is applied. At this time, when the rate of increasing the output pulse from the previous output at the time when the amplitude of the mover reaches an amplitude slightly smaller than the specified amplitude is reduced, overrun of the amplitude can be reliably prevented. The initial output pulse supplied to the coil is set to the minimum value, the output pulse is sequentially increased from the previous output to increase the amplitude of the mover, and when the amplitude reaches a predetermined amplitude smaller than the specified amplitude, the output of the detection means is output. Accordingly, overrun can be reliably prevented even when the operation mode is shifted to the normal operation mode in which the power supplied to the coil of the electromagnet is controlled. The output pulse supplied to the coil at the initial stage of startup is minimized, the output pulse is sequentially increased from the previous output to increase the amplitude of the mover, and the amplitude is detected by the detection means. When the amplitude reaches a possible amplitude, overrun can be reliably prevented even if the operation is shifted to the normal operation mode in which the power supplied to the coil of the electromagnet is controlled in accordance with the output of the detection means. Further, the output pulse at the initial stage of starting supplied to the coil is minimized, the output pulse is sequentially increased from the previous output to increase the amplitude of the mover, and the amplitude is detected by the detection means. After the time when the amplitude reaches the possible amplitude and until the amplitude of the mover reaches the specified amplitude, the mode is shifted to the normal operation mode in which the power supplied to the coil of the electromagnet is controlled according to the output of the detection means. However, overrun can be reliably prevented. In any case, the first output pulse or the first few pulses at the beginning of the startup are set to the maximum output, and then the output pulses are sequentially increased from the minimum value, so that the time required for the startup becomes longer. It will not be too long.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a time chart showing an operation in each example of an embodiment of the present invention. FIG. 2 is a time chart including a current waveform in the example of the above. FIG. 3 is a time chart showing an operation in a normal operation mode according to the first embodiment; FIG. 4 is a schematic diagram of the above. FIG. 5 is a block diagram of the above. FIG. 6 is an exploded perspective view of the above specific example. FIG. 7 is an exploded perspective view of the above mover. FIG. 8 is a block circuit diagram of the same. FIG. 9 is a time chart showing an operation at the time of conventional startup. [Description of Signs] 1 Stator 2 Mover 3 Frame 5 Control output unit 11 Coil 39 Sensor

Continuation of the front page (72) Inventor Yasuo Ibuki 1048 Kazuma Kadoma, Kadoma-shi, Osaka Matsushita Electric Works, Ltd. (56) References JP-A-8-331828 (JP, A) JP-A-62-244810 (JP, A) JP-A-2-52692 (JP, A) JP-B 64-9827 (JP, B2) JP-B-6-55235 (JP, B2) (58) Fields investigated (Int. Cl. 7 , DB name) H02P 7/00 101 H02P 5/00 101 H02K 33/00

Claims (1)

  1. (57) [Claims 1] A stator comprising an electromagnet or a permanent magnet;
    A mover having a permanent magnet or an electromagnet and supported by a spring, a detecting means for detecting at least one of displacement, speed, and acceleration of the mover, and a coil for the electromagnet in accordance with an output of the detecting means. A start-up control method for a linear vibration motor, comprising a control unit for controlling supply power,
    The initial output pulse supplied to the coil is set to the minimum value,
    Larger than before outputting sequentially output pulses, the amplitude of the movable element
    Output pulse when the amplitude reaches a little smaller than the specified amplitude
    A starter control method for a linear vibration motor, characterized in that the amplitude of the mover is increased to a specified amplitude by decreasing the ratio of increasing the amplitude of the mover to the previous output . 2. A stator comprising an electromagnet or a permanent magnet,
    Equipped with permanent magnet or electromagnet and supported by spring
    Mover and the displacement, speed and acceleration of the mover
    Detecting means for detecting at least one, and an output of the detecting means
    Control means for controlling the power supplied to the coil of the electromagnet according to
    A start control method for a linear vibration motor comprising:
    The initial output pulse supplied to the coil is set to the minimum value,
    Make the output pulse larger than the previous output to increase the amplitude of the mover.
    The predetermined amplitude is increased and the amplitude is smaller than the specified amplitude.
    If the width is reached, the coil of the electromagnet will be
    To normal operation mode to control the power supply to the
    And a method for controlling activation of a linear vibration motor. 3. A stator comprising an electromagnet or a permanent magnet;
    A mover having a permanent magnet or an electromagnet and supported by a spring, a detecting means for detecting at least one of displacement, speed, and acceleration of the mover, and a coil for the electromagnet in accordance with an output of the detecting means. A start-up control method for a linear vibration motor, comprising a control unit for controlling supply power,
    The initial output pulse supplied to the coil is set to the minimum value,
    The output pulse is sequentially increased from the previous output to increase the amplitude of the mover, and the amplitude is controlled by the detection means.
    A linear vibration motor for shifting to a normal operation mode in which the power supplied to the coil of the electromagnet is controlled in accordance with the output of the detection means at the time when the amplitude relating to the child has been detected. Startup control method. 4. A stator comprising an electromagnet or a permanent magnet,
    A starting control method for a linear vibration motor, comprising: a movable element including a permanent magnet or an electromagnet and supported by a spring; and a detecting unit configured to detect at least one of displacement, speed, and acceleration of the movable element, And the output pulse at the initial stage of supply is supplied to the minimum value, the output pulse is sequentially increased from the previous output to increase the amplitude of the mover, and the amplitude reaches the amplitude at which the detection of the mover by the detection means is possible. and the amplitude of the movable element is defined vibration at the time or later
    A method for controlling activation of a linear vibration motor, wherein a transition is made to a normal operation mode in which power supplied to a coil of an electromagnet is controlled in accordance with an output of the detection means at a point in time when the width reaches a width . 5. An output pulse or a repetition pulse of a detailed book at the beginning of startup.
    The first few pulses are the maximum output, then the output pulse is the minimum
    2. The method according to claim 1, wherein the value is sequentially increased from the value.
    5. The method for controlling the activation of a linear vibration motor according to any one of 4 .
JP04123997A 1997-02-25 1997-02-25 Startup control method for linear vibration motor Expired - Fee Related JP3468011B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP04123997A JP3468011B2 (en) 1997-02-25 1997-02-25 Startup control method for linear vibration motor

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP04123997A JP3468011B2 (en) 1997-02-25 1997-02-25 Startup control method for linear vibration motor

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JPH10243688A JPH10243688A (en) 1998-09-11
JP3468011B2 true JP3468011B2 (en) 2003-11-17

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Publication number Priority date Publication date Assignee Title
JP2005261173A (en) * 2004-03-14 2005-09-22 Mutsuo Hirano Reciprocating linear driver
JP2006271178A (en) * 2005-03-20 2006-10-05 Mutsuo Hirano Reciprocating linear engine
EP2410641A1 (en) 2010-07-23 2012-01-25 Braun GmbH Linear electric motor
US9154025B2 (en) 2010-07-23 2015-10-06 Braun Gmbh Personal care device
JP2012218077A (en) * 2011-04-05 2012-11-12 Makita Corp Electric power tool with linear motor
CA2841901A1 (en) 2011-07-25 2013-01-31 Braun Gmbh Linear electro-polymer motors and devices having the same
ES2451021T3 (en) 2011-07-25 2014-03-26 Braun Gmbh magnetic connection between a toothbrush handle and a brush head
PL2550938T3 (en) 2011-07-25 2015-06-30 Braun Gmbh Oral hygiene device
CN106849593B (en) * 2017-03-02 2018-11-02 歌尔股份有限公司 More driving linear vibration motors and electronic equipment

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