JP2002176758A - Linear oscillator and electric toothbrush - Google Patents

Abstract

PROBLEM TO BE SOLVED: To attain low noise and miniaturization. SOLUTION: This device is provided with a plunger 1 of freely supporting axial reciprocation, a spring member 60 of taking a movable section including the plunger as an oscillating system, an electromagnetic drive means for reciprocating the movable section at resonance frequency with alternating current applied, and a regulating means for regulating the around-axis rotation of the movable section. Thus, axial reciprocating oscillation can be attained directly.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a linear oscillator and an electric toothbrush in which a movable portion performs reciprocating vibration in an axial direction.

[0002]

2. Description of the Related Art In an electric toothbrush, when a reciprocating vibration for bus polishing is performed on a brush portion of the electric toothbrush, a linear oscillator for causing a movable portion to reciprocate in an axial direction is used as a driving source. The one that converts the rotational motion of a motor into a reciprocating linear motion by using a motion direction converting mechanism is used. In addition, even if a linear oscillator is used as a vibration generating means for generating mechanical vibration by causing a movable portion to perform reciprocating vibration in the axial direction, a reciprocating linear motion is obtained by using a motion direction converting mechanism for rotating the motor. Many are converted to movement.

[0003]

In the apparatus using such a moving direction converting mechanism, there is a problem in that energy efficiency is reduced and noise is caused by mechanical loss generated in the moving direction converting mechanism, and furthermore, downsizing is difficult. is there. Further, in the electric toothbrush, since the direction of movement of the motor shaft and the direction of the brush portion (action point) are different, a bending moment is generated during operation, which adversely affects the driving characteristics.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a linear oscillator and an electric toothbrush which are low noise, energy efficient, and can be downsized.

[0005]

SUMMARY OF THE INVENTION A linear oscillator according to the present invention comprises a plunger supported so as to freely reciprocate in an axial direction, and a spring member having a movable portion including the plunger as a vibration system. The first feature is that an electromagnetic drive means for reciprocatingly driving the movable section at its resonance frequency by applying an alternating current and a regulating means for regulating the rotation of the movable section around an axis are provided. A plunger that is freely supported to reciprocate in the axial direction, a coil spring that uses a movable part including the plunger as a vibration system, and that the movable part has its resonance frequency And an electromagnetic drive means for reciprocating the movable portion, and the coil spring changes an axial position of one end fixed to the movable portion in accordance with an axial expansion and contraction due to reciprocal vibration of the movable portion. Special The it has.

According to the first feature, the reciprocating linear vibration in the axial direction can be directly obtained. According to the second feature, the reciprocating linear vibration in the axial direction can be directly obtained. A rotational movement around it can also be obtained.

The electric toothbrush according to the present invention uses a linear oscillator for causing an axially reciprocable shaft to reciprocate in an axial direction as a drive source, and is driven by the shaft near an axial extension of the shaft. It is characterized by having a brush for brushing teeth.

The brush is preferably driven by reciprocating vibration. In particular, as the linear oscillator, a plunger which is supported so as to freely reciprocate in the axial direction,
A spring member having a movable part including the plunger as a vibration system, an electromagnetic drive means for reciprocally driving the movable part at its resonance frequency by applying an alternating current, and a regulation for restricting rotation of the movable part about an axis. Means, or a plunger which is freely reciprocated in the axial direction, a coil spring having a movable part including the plunger as a vibration system, and the movable part which is applied with an alternating current. And an electromagnetic drive means for reciprocatingly driving the movable portion at the resonance frequency thereof. The coil spring preferably changes the position of one end fixed to the movable portion around the axis in accordance with the axial expansion and contraction due to the reciprocal vibration of the movable portion. be able to.

In addition, the axial vibration stroke of the linear oscillator may be variable, and may be provided with control means for changing the operation of the linear oscillator after a predetermined time has elapsed. May be provided with control means for gradually increasing.

[0010]

FIG. 1 shows an embodiment of the present invention. A cylindrical plunger 1 made of a magnetic material such as iron material has a large diameter near both ends in the axial direction. The center portion has a small diameter, a shaft 7 is attached, and an annular coil 5 is disposed on the outer periphery of the plunger 1. On both sides in the axial direction of the coil 5 fixed to the inner surface of the shield case 10, annular permanent magnets 40 and 41 symmetrically magnetized with respect to the coil 5 are provided. An annular second yoke 30, 31 is provided between the coil 41 and the coil 5, and the permanent magnet 4
Ring-shaped first yokes 20, 21 are arranged at positions opposite to the yokes 30, 31 of 0, 41.

One end of the shaft 7 is slidably held in the shield case 10 through a bearing 80 in the axial direction. As shown in FIG. By engaging with the protrusion provided on the case 10, rotation of the shaft 7 and the plunger 1 around the axis is restricted. The other end of the shaft 7 has a shield case 1
A spring 60 which is interposed between the inner surface of the plunger 1 and the end surface of the plunger 1 is provided. One end of the spring 60, which is a coil spring, is fixed to the shield case 10 and the other end is fixed to the plunger 1, and expands with the axial movement of the plunger 1 to apply a compression spring force and a tension spring force to the plunger 1. Let it work.

In this embodiment, when no current is applied to the coil 5, the permanent magnets 40, 41 are connected to the yokes 20, 30, 2,
Magnetic force and spring 6 acting on plunger 1 via 1, 31
The plunger 1 is stationary at the illustrated position where the spring force of 0 is balanced. When a one-way current is applied to the coil 5, the magnetic flux of one of the two permanent magnets 40 and 41 is weakened, and moves toward the other magnet against the spring 60, and the reverse current flows through the coil 5. , The spring 60
The plunger 1 reciprocates in the axial direction by passing an alternating current through the coil 5 at this time, and the spring constant of the spring 60 and the plunger 1 and the shaft The reciprocating vibration becomes a vibration in a resonance state by flowing an alternating current in the vicinity of a resonance frequency determined by the mass of the movable portion 7 to the coil 5.

FIG. 2 shows a spring 60 using a leaf spring having an outer periphery fixed to the shield case 10 and an inner periphery fixed to the shaft 7. The spring 60 functions as a member for preventing the shaft 7 from rotating. Also plays.

As shown in FIG. 3, a spring 61 is also arranged between the shield case 10 and the other side of the plunger 1 opposite to the spring 60 so that the two springs 60, 61 act on the plunger 1. Alternatively, as shown in FIG.
Each of the two springs 60 and 61 may be constituted by a leaf spring,
As shown in FIG. In this case, the operation is performed at the resonance frequency determined by the spring constant of the two springs 60 and 61 and the mass of the movable part. 4 and 5, the shaft 7 can be supported without the bearing 80.

The spring force for determining the resonance frequency may use a detent force. In this case, the spring 60 (61) is not required as shown in FIG.

FIG. 7 shows a spring 60 which is a coil spring in which one end is fixed to the shield case 10 and the other end of the spring 60 is also fixed to the plunger 1. In this case, the spring 60, which is a coil spring, not only exerts a spring force in the axial direction of the plunger 1, but also gives the plunger 1 a small-angle rotation around the axis with the expansion and contraction in the axial direction. Not only directional vibration but also reciprocal rotation at a small angle around the axis can be obtained. In addition, since the rotation around the axis is made as if a torsion spring is added, resonance can also be generated in the rotation direction. Note that a linear oscillator that can obtain such an output can be suitably used as a power source of an electric toothbrush that requires a bus operation and a rolling operation.

FIG. 8 shows an example in which the linear oscillator M, which is a linear vibration motor, is used as a power source for an electric toothbrush. A linear oscillator M is accommodated in an upper portion of a housing 11 formed in a thin cylindrical shape, and a battery (primary battery or secondary battery) 12 as a power source and a drive control circuit of the linear oscillator M are mounted in a lower portion of the housing 11. A circuit board 13 is housed, and a switch 14 is provided at the upper end. Then, one end of the shaft 7 in the linear oscillator M is made to protrude from the upper end of the housing 11,
A brush base 16 provided with a brush 17 on the tip side is connected to the upper end of the shaft 17. Axis 7 with linear oscillator M
The brush stand 16 connected so as to be aligned with the shaft 7 also vibrates in the axial direction. For this reason, the brush 17 in the brush stand 16 performs an operation for polishing the bus, and when the linear oscillator M shown in FIG. Operation will be performed.

FIG. 9 shows an example of a drive control circuit mounted on the circuit board 13. In a drive control circuit comprising a power supply block B1, a waveform generation circuit block B2, and a drive circuit block B3, the waveform shaping thereof is performed. The circuit block B2 incorporates a drive power control circuit for controlling the power supplied to the linear oscillator M.

For example, when this driving power control circuit outputs pulses of voltages a and -a at a period T shown in FIG. 10, a pulse whose duty ratio is changed as shown in FIG. That can output
One that can change the amplitude as shown in (b) (n is a multiple) and one that can change the type of waveform as shown in FIGS. 12 (a) and (b) can be used. . The driving power amount may be changed by an arbitrary combination of these. In any case, the displacement amount of the brush 17 can be changed by changing the driving power amount, so that the displacement amount of the brush 17 can be set to a user's preference.

Further, as shown in FIG. 13, if driving is performed for a predetermined time t1 such as 120 seconds, the operation is stopped for a time t2 (for example, 0.3 seconds), operated for a time t3 (for example, 0.3 seconds), and operated for a time t4 (for example, 0.3 seconds). If, for example, 0.3 seconds) is stopped and then operated again for the time t1, it is possible to notify the user that the predetermined time t1 has elapsed. It is possible to know the elapsed time of brushing and prevent a situation such as insufficient brushing or excessive brushing.

In addition, as shown in FIG. 14, if the driving power is controlled so that the displacement of the brush 17 is increased stepwise from the time when the power is turned on, the brush 17 is coated with toothpaste or water. Turn the power on with the brush
It is possible to reduce the risk that the dentifrice or water will be scattered before the mouth 7 is contained in the mouth. T01, t02,
Preferably, t03 is, for example, about 0.6 seconds each, but is not limited thereto.

[0022]

As described above, the first feature of the linear oscillator according to the present invention is that the plunger is supported so as to be freely reciprocated in the axial direction, and that the linear oscillator includes the plunger. A spring member whose part is a vibration system,
Since an alternating current is applied, an electromagnetic drive unit that reciprocally drives the movable unit at its resonance frequency and a regulating unit that regulates rotation of the movable unit around an axis are provided, so that electric energy is directly planned. It can be converted to linear reciprocating motion of a movable part including a jar, and a motion conversion mechanism for converting rotary motion to linear motion is unnecessary. In particular, it is highly efficient because it utilizes resonance, and has low noise and Since it can be downsized, it can be suitably used for a drive unit for machine control, a drive unit for an electric razor or an electric toothbrush, and the like, and has a regulating means for regulating rotation around an axis, Only the reciprocating linear motion can be reliably performed by the movable portion.

In the second feature,
A plunger freely reciprocatingly supported in the axial direction, a coil spring having a movable part including the plunger as a vibration system, and reciprocal driving of the movable part at its resonance frequency by applying an alternating current. With the electromagnetic drive means, a motion conversion mechanism for converting a rotary motion into a linear motion is not required, and high efficiency is achieved because resonance is utilized. In addition to the above, in addition to the axial reciprocating linear vibration, the coil spring changes the position around the axis of one end fixed to the movable part with the axial expansion and contraction due to the reciprocating vibration of the movable part. It can also obtain a rotational movement about an axis synchronized with the reciprocating linear vibration, and can be suitably used for an electric toothbrush requiring a bus operation and a rolling operation.

In the electric toothbrush according to the present invention, the drive source is a linear oscillator that causes the shaft capable of reciprocating in the axial direction to reciprocate in the axial direction, and the shaft near the axial extension of the shaft. , The generation of a bending moment that adversely affects the driving characteristics can be reduced, and energy can be used efficiently. Here, the reciprocating vibration of the shaft is converted into rotation around the axis in a direction orthogonal to the shaft, and the rotation of the brush is included.

However, if the brush is driven by reciprocating vibration, the brush may be directly driven by the shaft. Therefore, it is possible to obtain a brush capable of performing efficient brush driving with a small number of parts. it can.

In particular, as a linear oscillator, a plunger which is supported so as to freely reciprocate in the axial direction, a spring member having a movable portion including the plunger as a vibration system, and By using an electromagnetic driving means for reciprocatingly driving the portion at its resonance frequency and a regulating means for regulating the rotation of the movable portion around the axis, it is possible to obtain a device which can surely make the brush perform only the rectilinear motion. I can do that.

Further, as a linear oscillator, a plunger which is supported so as to freely reciprocate in the axial direction, a coil spring having a movable part including the plunger as a vibration system, and an alternating current is applied to the linear oscillator. Electromagnetic drive means for reciprocatingly driving the movable part at its resonance frequency, and the coil spring is used for changing the position of one end fixed to the movable part around the axis as the movable part expands and contracts in the axial direction due to reciprocal vibration of the movable part. If this is the case, it is possible to easily obtain one that causes the brush to perform the bus operation and the rolling operation as described above.

In addition, if the axial oscillation stroke of the linear oscillator is variable, the movement of the brush can be adjusted to the user's preference.

[0029] Further, with the control means for changing the operation of the linear oscillator when a predetermined time elapses, the user can know the brushing time for brushing the teeth.

Further, in the apparatus provided with the control means for gradually increasing the axial vibration stroke when the linear oscillator is started, even if the power is turned on before the brush is put in the mouth, the dentifrice and water attached to the brush are scattered. There is no.

[Brief description of the drawings]

FIG. 1 shows an example of an embodiment of the present invention, in which (a)
Is a sectional view, and (b) is a partial sectional view.

FIG. 2 is a sectional view of another example of the above.

FIG. 3 is a sectional view of still another example of the above.

FIG. 4 is a sectional view of another example of the above.

FIG. 5 is a sectional view of still another example of the above.

FIG. 6 is a sectional view of another example of the above.

FIG. 7 is a sectional view of another example of the above.

FIG. 8 is a cross-sectional view of an example of the electric toothbrush.

FIG. 9 is a block circuit diagram of the above.

FIG. 10 is a time chart showing a driving waveform of the above.

FIGS. 11A and 11B are time charts showing other driving waveforms of the above.

FIGS. 12A and 12B are time charts showing still another driving waveform according to the first embodiment.

FIG. 13 is an explanatory diagram of the operation of the above.

FIG. 14 is another operation explanatory view of the above embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Plunger 5 Coil 7 axis 10 Shield case 20, 21 First yoke 30, 31 Second yoke 40, 41 Permanent magnet

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Eiichi Yabuuchi 1048 Kadoma Kadoma, Osaka Prefecture Matsushita Electric Works, Ltd. (72) Inventor Hiromiki Inoue 1048 Kadoma Kadoma, Kadoma, Osaka Prefecture Matsushita Electric Works, Ltd. (72) Inventor: Masayuki Suzuki 1048, Kadoma, Kadoma, Osaka Pref.Matsushita Electric Works, Ltd. Matsushita Electric Works Co., Ltd., 1048, Kadoma, Kadoma, Fumonma-shi (72) Inventor Katsuhiro Hirata 1048, Kadoma, Kadoma, Kadoma, Osaka, Japan Inside the Electric Works Co., Ltd. (72) Inventor Yoshitaka Ichii 1048 Kazuma Kadoma, Kadoma-shi, Osaka F-term inside the Matsushita Electric Works Co., Ltd. 3B202 AA06 B C08 BE09 5H633 BB07 BB10 GG02 GG04 GG05 GG09 GG12 HH02 HH06 JA02 JA09 JB05

Claims (9)

[Claims] 1. A plunger movably supported in a reciprocating motion in an axial direction, a spring member having a movable portion including the plunger as a vibration system, and the movable portion being moved by applying an alternating current to the plunger. Electromagnetic driving means for reciprocatingly driving at a resonance frequency;
A linear oscillator, comprising: a restricting means for restricting rotation of the movable portion around an axis. 2. A plunger which is supported so as to freely reciprocate in an axial direction, a coil spring having a movable portion including the plunger as a vibration system, and the movable portion is moved by applying an alternating current thereto. Electromagnetic drive means for reciprocatingly driving at a resonance frequency, and wherein the coil spring changes an axial position of one end fixed to the movable part with axial expansion and contraction due to reciprocal vibration of the movable part. And a linear oscillator. 3. A tooth brush which is driven by a linear oscillator which causes an axially reciprocable shaft to reciprocally vibrate in an axial direction as a drive source, and which is provided near the axial extension of the shaft. An electric toothbrush comprising: 4. The electric toothbrush according to claim 3, wherein the brush is driven by reciprocating vibration. 5. A linear oscillator, comprising: a plunger supported so as to freely reciprocate in an axial direction; a spring member having a movable portion including the plunger as a vibration system; 5. The electric toothbrush according to claim 3, further comprising: an electromagnetic driving means for reciprocatingly driving the movable portion at its resonance frequency; and a restricting means for restricting rotation of the movable portion around an axis. 6. A linear oscillator, comprising: a plunger supported so as to freely reciprocate in an axial direction; a coil spring having a movable portion including the plunger as a vibration system; An electromagnetic drive means for reciprocatingly driving the movable portion at its resonance frequency, wherein the coil spring changes an axial position of one end fixed to the movable portion with an axial expansion and contraction due to reciprocal vibration of the movable portion. The electric toothbrush according to claim 3 or 4, wherein: 7. The electric toothbrush according to claim 3, wherein an axial vibration stroke of the linear oscillator is variable. 8. The electric toothbrush according to claim 3, further comprising control means for changing the operation of the linear oscillator when a predetermined time has elapsed. 9. The electric toothbrush according to claim 3, further comprising control means for gradually increasing the axial vibration stroke when starting the linear oscillator.