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

Description

Detailed Description of the Invention

[0001]

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 causes a linear motor to reciprocate.

[0002]

2. Description of the Related Art JP-A-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 has a mover made of a rod-shaped permanent magnet, and a U
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 a full-wave rectifier circuit supplies a DC voltage of twice the AC frequency to the coil. The mover is reciprocating.

In this case, a strong electromagnetic force is required to reciprocally move the mover to generate vibration, but the mover is supported by a spring to constitute a spring vibration system, and the natural vibration of this spring vibration system. Driving at a frequency that matches the number can reduce the energy required for driving. However, when such driving is performed, the amplitude of reciprocating vibration is not stable when a load is applied. have.

To this end, a stator composed of an electromagnet or a permanent magnet, a mover having a permanent magnet or an electromagnet and spring-supported, and at least one of displacement, speed, and acceleration of the mover are detected. What is provided is a detection means and a control means for controlling the electric power supplied to the coil of the electromagnet according to the output of the detection means. With this device, even if the amplitude changes for some reason, the amplitude change can be detected by the detection means that detects at least one of displacement, velocity, and acceleration of the mover. By supplying electric power in accordance with the above, it is possible to make the amplitude constant, and it is possible to reliably obtain a reciprocating vibration having a stable amplitude.

By the way, in the above linear vibration motor,
When the control according to the output of the detection means cannot be performed,
That is, at the time of start-up, current supply to the coil of the electromagnet by PWM control or the like is operated with the maximum output pulse as shown in FIG. 9, and if the amplitude of the mover reaches the specified amplitude S1, the output of the detection means is responded. I was trying to transfer to control.

[0006]

In this case, an overrun in which the amplitude of the mover exceeds the specified amplitude S1 often occurs, and an overload is often given to the components of the linear vibration motor. Further, 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 drive element will increase.

The present invention has been made in view of the above problems of the prior art, and an object thereof is to provide a start-up control method for a linear vibration motor which can appropriately perform start-up. .

[0008]

SUMMARY OF THE INVENTION The present invention, however, is directed to a stator composed of an electromagnet or a permanent magnet, a mover provided with a permanent magnet or an electromagnet and spring-supported, and displacement, speed, and acceleration of the mover. A start-up control method for a linear vibration motor, comprising: a detection means for detecting at least one of the detection means and a control means for controlling the electric power supplied to the coil of the electromagnet according to the output of the detection means. It is characterized in that the output pulse in the initial stage of start-up is set to the minimum value and the output pulse is successively increased from the previous output to increase the amplitude of the mover to the specified amplitude. Since the output is gradually increased, it does not fall into the state 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 is reduced when the amplitude of the mover reaches an amplitude slightly smaller than the specified amplitude, overrun can be surely prevented. The output pulse of the initial stage supplied to the coil is set to the minimum value, the output pulse is increased sequentially 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, the normal operation mode in which the electric power supplied to the coil of the electromagnet is controlled may be shifted.

Further, the output pulse at the initial stage of activation supplied to the coil is set to the minimum value, and the output pulse is successively increased from the previous output to increase the amplitude of the mover, and the amplitude is detected by the detecting means with respect to the mover. When the amplitude reaches a level at which the electric power can be controlled, the normal operation mode in which the electric power supplied to the coil of the electromagnet is controlled according to the output of the detection means may be entered.

Further, the output pulse to be supplied to the coil at the initial stage of activation is set to the minimum value, and the output pulse is successively increased from the previous output to increase the amplitude of the mover, and the amplitude is detected by the detecting means for the mover. After the time when the amplitude reaches the possible amplitude and before the amplitude of the mover reaches the specified amplitude, 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 is set. May be.

In either case, the maximum output is the first output pulse or the first several pulses in the initial stage of startup, and then the output pulse is gradually increased from the minimum value, thereby increasing the time required for startup. There is no passing.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION 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, in which a stator 1 and a mover 2 ( In the figure, two movers 21 and 2 are shown.
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 this yoke 10.
The coil 11 is wound around the central piece of the above, and pins 12 are provided so as to project from both end surfaces of the yoke 10. The frame 3 to which the stator 1 is fixed has a bottom plate 31, 31 between the lower parts of the ends of the pair of side plates 30, 30, respectively.
The stator 1 has its pins 12 fitted in fixing grooves 32 formed in the side plate 30 and fixed to the frame 3 by welding or caulking.

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 surface of driven bodies 23, 23 made of synthetic resin. The permanent magnet 20 is fixed to the driven body 23 of the mover 21 in a planar shape in a square shape, and the reinforcing plate 25, the back yoke 26, and the permanent magnet 2 are provided.
0 is provided on each lower surface of both side pieces of the driven body 23,
Further, the reinforcing plates 25 on both sides are integrally formed.
The reinforcing plate 25 is integrated with the driven body 23 by insert molding (outsert molding). Reference numeral 24 in the drawing denotes a connecting portion which is integrally provided on the driven body 23 and to which the inner blade of the reciprocating electric shaver is connected.

Both ends of the movers 21 and 22 are connected to the frame 3 via leaf springs 4 and 4. The leaf spring 4 here is formed by punching from the metal plate 4 ', and the support plate 40 is attached to the fixed portion to the frame 3 and the connecting plate 43 is attached to the fixed portion to the movers 21 and 22, respectively. The central plate spring part 41 connected to the mover 22 and the pair of left and right plate spring parts 42, 42 connected to the mover 21 are integrally connected at the support plate 40. 40 is fixed to both ends of the frame 3 by means such as welding, and each connecting plate 43 is attached to the mover 2
When fixed to the end portions of the reinforcing plates 25 of the Nos. 1 and 22 by means such as welding, both the movers 21 and 22 are suspended from the frame 3, and are placed inside the mover 21 having a square shape in plan view. The connecting portion 24 of the mover 22 is located. Also,
Between the spring bearing portions 26, 26 on the inner surface of the mover 21 and the spring bearing portions 27, 27 of the connecting portion 24 of the mover 22, a pair of compression coil springs are 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 vertically opposes the stator 1 with a predetermined gap, and the reciprocating direction of the mover 2 is increased and decreased. As shown in FIG. 4, the leaf spring 4 is bent and moved left and right in accordance with the direction of the current flowing through the coil 11 of the stator 1, as shown in FIG. By switching the direction at an appropriate timing, the mover 2 can be caused to perform reciprocating vibration.

Further, 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
1 and 22 perform reciprocating vibrations whose phases are different 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 the magnetic attraction force is further added). ing.

In vibrating the 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 bring it into a resonance state in order to realize stable vibration and drive energy. In order to perform such driving, here, in order to perform such driving, the sensing magnet 29 whose magnetic poles are arranged in the reciprocating direction of the movable element 2 is attached to the movable element 21 and is provided on the frame 3. The sensor 39 including the sensing winding shown in FIG. 4 is attached to the mounting portion 34, and the control output portion 5 causes the coil 11 to move based on the current (voltage) induced in the sensor 39 with the vibration of the mover 21. It controls the current flowing to the.

That is, as shown in FIG. 3, the voltage of the current induced in the sensor 39 changes according to the magnitude and position of the amplitude of the mover 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 its reciprocating motion, the movement of the magnet 29 stops and the change of the magnetic flux disappears, and the output of the sensor 39 becomes zero. The speed of No. 2 becomes maximum 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, the zero point can be detected as the moving direction reversal time (dead point arrival time), and the mover 2 can be detected from the polarity of the output of the sensor 39. The moving direction of can be detected.

An example is shown in FIG. The output voltage of the sensor 39 changes in a sine curve, which is amplified by the amplifier circuit 51 and then converted into a digital value by the A / D conversion circuit 52 so that the output voltage has passed a predetermined time (for example, t) 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 at which the output voltage reaches from zero to zero. The time when the moving direction is reversed can be detected from the time when the current becomes, and the direction in which the current flows changes depending on whether the moving direction of the mover 2 (magnet 29) is reciprocating. It is possible to detect which stroke of the reciprocating motion the movable element 2 has.

Here, when the control output unit 5 detects, for example, a decrease in amplitude due to an increase in load, from the detected speed of the mover 2, it increases the drive current amount (energization time T and maximum current value in the illustrated example). By doing so, the amplitude is maintained at a required value. In the illustrated example, the control of the drive current amount is based on the PWM control, and the current amount outputs the PWM pulse width stored in advance for the detected speed. Since velocity, displacement, and acceleration are correlated, displacement and acceleration may be detected instead of velocity.

Further, by causing a current to flow in the direction corresponding to the detected moving direction, it is possible to prevent a situation in which the drive current becomes a brake. Furthermore, by flowing a current at a timing of a predetermined time t from the detected movement direction reversal t1, the movement of the mover 2 is effectively utilized by the movement of the spring system to suppress the necessary amount of current. In other words, if a reverse driving current is applied to the coil 11 before reversing 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. When the coil 11 is added, since the driving force due to the repulsive force of the spring system compressed by the vibration of the mover 2 is already weak, a synergistic force between the driving by the electromagnetic force and the driving force by the spring system is generated. Can't get For this reason, the start timing of the current supply to the coil 11 is set within the time from the time when the moving direction is reversed to the center of the amplitude. The time when the center of the amplitude is reached can be detected as the point where the output of the sensor 39 is maximized. The time t here may be a value adjusted according to the detected speed and 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
In the drive block 53 composed of four, the switching elements Q1 and Q3 are turned on at the same time, and the switching elements Q2 and Q4 are turned on at the same time to switch the direction of the current flowing through the coil 11 to reciprocate to the mover 2. Make a move.

By the way, in the above drive control, it is not always necessary to detect the moving direction and the 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 since it is synchronized with the natural frequency, energization is started at a required cycle. Because you can do it. However, if the above control corresponding to these detections is also performed, even if a temporary stop due to overload occurs, it is possible to flow current in an appropriate direction, and
The drive current is always properly applied to the coil 11 even if the natural frequency varies due to the individual difference of the mass of the mover 2 and the spring constant of the spring system, and therefore the vibration system is sure to generate the natural vibration. It converges to a number and vibrates with a constant amplitude.

As a detection means, a combination of a sensing magnet 29 capable of detecting the moving direction, a moving direction reversal time point, and a position (velocity or acceleration) and a sensor 39 composed of 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 moving direction reversal time point without being influenced by the variation in the magnetic force of the magnet 29 and the variation 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 of.

In addition, for example, a combination of a sensing magnet 29 and a magnetic 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 etc.
It can be used according to the detection target. However, a non-contact type that does not interfere with the vibration of the mover 2 is preferable.

In the linear vibration motor constructed as described above, the 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 start-up, the start-up procedure is set in advance in the start-up setting unit 50 shown in FIG. This start is shown in FIG.
As shown in, the output pulse in the initial stage of activation supplied to the coil 11 of the electromagnet 1 is set to the minimum value, and then the output pulse is successively increased from the previous output to increase the amplitude of the mover. The normal operation mode is shifted according to the output of.

At this time, if the output pulse is made larger than the previous output until the amplitude of the mover 2 reaches the specified amplitude S1 as shown in A of FIG. 1, as shown by the broken line from point a in the figure. However, since overrun is likely to occur, the output pulse is pre-output at the time b when the amplitude of the mover 2 reaches the amplitude S3 which is slightly smaller than the specified amplitude S1, as indicated by B in FIG. By decreasing the rate of increase and moving to the normal operation mode when reaching 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.

It is also possible to shift to the normal operation mode at the time point of b. In this case, the specified amplitude S1 is reached at the point e. Not at the point of time b, but at a time point f at which the detection means reaches the amplitude value S2 at which the amplitude of the mover 2 can be detected directly or indirectly, or after the point f and until the specified amplitude S1 is reached. At the time point h (t ′) of
You may shift to a normal operation mode. g and i respectively indicate the times when the prescribed amplitude S1 is reached.

By the way, if the initial output pulse in the initial stage of starting is small, the time required for starting is inevitably long. Therefore, as shown by C in FIG. Then, when the output pulse is successively increased from the minimum value, as shown in FIG.
As shown by j in FIG.
The time required for startup can be shortened.

[0032]

As described above, according to the present invention, the output pulse in the initial stage of starting the supply to the coil is set to the minimum value, and the output pulse is increased sequentially from the previous output to increase the amplitude of the mover to the specified amplitude. Yes, because the output is gradually increased, it does not fall into the state of mechanical overload or electrical overload such as overrun, and the life of the linear vibration motor can be maintained for a long time. Since the driving power is gradually increased from the above to the maximum power in the end, it can be started even in the state where the maximum load is applied.

At this time, when the amplitude of the mover reaches an amplitude slightly smaller than the specified amplitude, the rate of increasing the output pulse from the previous output is reduced to surely prevent the amplitude overrun. The output pulse of the initial stage supplied to the coil is set to the minimum value, the output pulse is increased sequentially 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, even if the normal operation mode in which the power supplied to the coil of the electromagnet is controlled is changed, overrun can be reliably prevented.

Further, the output pulse in the initial stage of activation supplied to the coil is set to the minimum value, the output pulse is successively increased from the previous output to increase the amplitude of the mover, and the amplitude is detected by the detecting means with respect to the mover. When the amplitude reaches a level at which the electric power can be controlled, the overrun can be surely prevented even by shifting to the normal operation mode in which the electric power supplied to the coil of the electromagnet is controlled according to the output of the detection means.

Further, the output pulse in the initial stage of activation supplied to the coil is set to the minimum value, and the output pulse is increased sequentially from the previous output to increase the amplitude of the mover, and the amplitude is detected by the detecting means as to the mover. After the time when the amplitude reaches the possible amplitude and before the amplitude of the mover reaches the specified amplitude, 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 is set. However, overrun can be surely prevented.

In any case, the maximum output is the first output pulse or the first several pulses in the initial stage of startup, and then the output pulse is sequentially increased from the minimum value, thereby increasing the time required for startup. It will not pass by.

[Brief description of drawings]

FIG. 1 is a time chart showing an operation in each example of an exemplary embodiment of the present invention.

FIG. 2 is a time chart including a current waveform in the above example.

FIG. 3 is a time chart showing the operation in the normal operation mode of the above.

FIG. 4 is a schematic view of the above.

FIG. 5 is a block diagram of the same.

FIG. 6 is an exploded perspective view of the above specific example.

FIG. 7 is an exploded perspective view of the mover of the above.

FIG. 8 is a block circuit diagram of the above.

FIG. 9 is a time chart showing a conventional startup operation.

[Explanation of symbols]

1 stator 2 mover 3 frames 5 Control output section 11 coils 39 sensors

Front page continued (72) Inventor Yasuo Ibuki 1048, Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Works, Ltd. (56) Reference 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 (5)

(57) [Claims] 1. A stator comprising an electromagnet or a permanent magnet,
A mover that is provided with a permanent magnet or an electromagnet and is spring-supported, a detection unit that detects at least one of displacement, velocity, and acceleration of the mover, and a coil of the electromagnet according to the output of the detection unit. A start-up control method for a linear vibration motor, comprising a control means for controlling power supply,
Minimize the output pulse at the initial stage of supply to the coil,
Sequential output pulse is made larger than the previous output , and the amplitude of the mover is
Output pulse when the amplitude reaches a little smaller than the specified amplitude
A method of starting control of a linear vibration motor is characterized in that the amplitude of the mover is increased to a specified amplitude by decreasing the ratio of increasing the output power to the specified output . 2. A stator comprising an electromagnet or a permanent magnet,
It has a permanent magnet or electromagnet and is spring-supported.
The mover that has a smaller displacement, speed, or acceleration
A detection means for detecting at least one and an output of the detection means
Control means for controlling the electric power supplied to the coil of the electromagnet according to
A start-up control method for a linear vibration motor consisting of
Minimize the output pulse at the initial stage of supply to the coil,
Increase the amplitude of the mover by sequentially increasing the output pulse from the previous output.
As the amplitude is increased,
When the width is reached, the coil of the electromagnet is responsive to the output of the detection means.
To the normal operation mode that controls the power supplied to the
A starting control method for a linear vibration motor characterized by : 3. A stator comprising an electromagnet or a permanent magnet,
A mover that is provided with a permanent magnet or an electromagnet and is spring-supported, a detection unit that detects at least one of displacement, velocity, and acceleration of the mover, and a coil of the electromagnet according to the output of the detection unit. A start-up control method for a linear vibration motor, comprising a control means for controlling power supply,
Minimize the output pulse at the initial stage of supply to the coil,
The amplitude of the mover is increased by sequentially increasing the output pulse from the previous output, and the amplitude is moved by the detecting means.
A linear vibration motor characterized by shifting to a normal operation mode for controlling the electric power supplied to the coil of the electromagnet in accordance with the output of the detection means when the amplitude of the detection of the child is reached. Startup control method. 4. A stator comprising an electromagnet or a permanent magnet,
A start-up control method for a linear vibration motor, comprising: a mover provided with a permanent magnet or an electromagnet and spring-supported; and a detection means for detecting at least one of displacement, speed, and acceleration of the mover. The output pulse in the initial stage of start-up supplied to is set to the minimum value, and the output pulse is increased sequentially from the previous output to increase the amplitude of the mover, and the amplitude reaches the amplitude at which the detecting means can detect the mover. After that time , and the amplitude of the mover
A start-up control method for a linear vibration motor, which is characterized in that a normal operation mode in which the power supplied to the coil of the electromagnet is controlled according to the output of the detection means is reached before the width is reached . 5. The output pulse or the final output of the document in the initial stage of startup
Maximum output for the first few pulses, then minimum output pulse
The value is sequentially increased from a value.
4. The start control method for a linear vibration motor according to any one of 4 above .