JP2010082361A - Washing machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a washing machine for generating mist and preventing a fault in the circuit of an ultrasonic element. <P>SOLUTION: Frequency adjustment control is performed (periods TA, TB), where water is supplied (a circulation pump is ON) to a mist generator including the ultrasonic element during a mist control period (Twm), and a frequency to be oscillated by the ultrasonic element is adjusted. When the frequency adjustment control is terminated, stop control is performed (a period TC), where the frequency is set to be a value around an anti-resonance frequency, and then, the driving of a driving means is stopped. The water supply to the mist generator is made to continue even during the stop control, and then, stopped (the circulation pump is OFF) at a timing to stop the driving of the ultrasonic element. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a washing machine, and more particularly to a washing machine including a device that generates mist in accordance with ultrasonic vibration of an ultrasonic element.

  Conventionally, various washing machines for cleaning an object to be cleaned using ultrasonic vibration of an ultrasonic element have been proposed.

  Japanese Patent Application Laid-Open No. 2004-133620 discloses a method of cleaning an object to be cleaned partially by ultrasonic vibration by optimally controlling vibration of an ultrasonic element in a washing machine. Specifically, in Patent Document 1, in order to control the ultrasonic vibration of the ultrasonic element, the voltage of the power to the ultrasonic element so that the amplitude of the vibration of the ultrasonic element is an amplitude within a predetermined range. It is described that the frequency is controlled.

Patent Document 2 discloses a method in which mist is generated by ultrasonic vibration and the mist is sprayed on an object to be cleaned. Specifically, in the washing pretreatment step, the ultrasonic vibrator is driven to scatter the high-concentration detergent liquid to the inner tub, and the mist-like high-concentration detergent liquid is adhered to every corner of the clothing. It is described.
Japanese Patent Laid-Open No. 2007-232 JP 2005-118648 A

  However, in the invention of Patent Document 1, since the ultrasonic element is not for generating mist, the timing of water supply is not described, and the spray location is caused by the water supplied during the period when the ultrasonic vibrator is stopped. There is a problem of getting wet. Patent Document 2 does not disclose specific control of the ultrasonic element itself.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a washing machine capable of generating mist and preventing failure of the circuit of the ultrasonic element. Is to provide.

  A washing machine according to an aspect of the present invention includes an ultrasonic element for ultrasonic vibration, and drives the ultrasonic element with a mist generating unit that sprays the supplied liquid in a mist form according to the ultrasonic vibration of the ultrasonic element. Drive means, water supply means for supplying water to the mist generating means, and control means for performing control for washing the article to be cleaned, the control means, water supply control means for controlling the water supply means, And adjustment control means for executing adjustment control for adjusting the frequency at which the ultrasonic element vibrates ultrasonically with respect to the drive means when water is supplied to the mist generating means. The adjustment control means adjusts the frequency within the range of the resonance frequency where the impedance of the ultrasonic element is low and the anti-resonance frequency where the frequency is higher than the resonance frequency and the impedance of the ultrasonic element is high. A specific frequency representing the frequency is searched, and control for maintaining the searched specific frequency is performed. The control means further includes a stop control means for stopping the driving of the driving means after setting the frequency to a value near the anti-resonance frequency when the adjustment control is finished. The water supply control means stops water supply to the mist generating means at a timing when the drive of the drive means is stopped.

  Preferably, the adjustment control means adjusts the frequency so as to approach the resonance frequency side from the anti-resonance frequency side, and the stop control means performs control to return from a specific frequency to a value near the anti-resonance frequency.

  Preferably, the value near the anti-resonance frequency corresponds to the initial value of frequency adjustment in the adjustment control.

  Preferably, the stop control means adds the frequency stepwise with a width larger than the frequency adjustment width at the time of adjustment control, and determines that the frequency has reached a value near the anti-resonance frequency. Stop driving.

  Preferably, current detection means for detecting current flowing in the ultrasonic element is further provided, and the adjustment control means adjusts the frequency based on the current value detected by the current detection means.

  According to the present invention, when stopping the vibration of the ultrasonic element, the value is set to a value near the anti-resonance frequency and then stopped, so that the current flowing through the circuit of the ultrasonic element is sufficiently reduced before driving the ultrasonic element. Can be stopped. Therefore, failure of the ultrasonic element circuit can be prevented.

  In addition, according to the present invention, water supply to the mist generating means is stopped at the timing when the driving of the ultrasonic element is stopped, so that it is possible to stop the water that has not become mist from flowing into the water tank.

  Embodiments of the present invention will be described below with reference to the drawings. In the following description, the same parts and components are denoted by the same reference numerals. Their names and functions are also the same.

<About schematic configuration>
FIG. 1 is a diagram illustrating a schematic configuration viewed from the front side of the washing machine according to the embodiment of the present invention.

  With reference to FIG. 1, the washing machine 200 has substantially the same configuration as a conventional drum-type washing machine except for a mist generator 100 that generates and sprays mist, which will be described later, and a schematic configuration will be described.

  The outer box 216 has a rectangular parallelepiped shape and is formed of metal or synthetic resin, and a water tank 214 for introducing an object to be cleaned is provided therein. A rotatable drum (not shown) having an inner door 230 is provided inside the water tank 214. The water tank 214 and the rotating drum are in the shape of a cylindrical cup with an open front side, and are concentrically arranged with the water tank 214 on the outside and the rotating drum on the inside. Further, the water tank 214 and the rotating drum are arranged so that the rear surface portion is lower than the front surface portion (inner door side).

  A blower duct 212 through which hot air to be supplied into the rotating drum flows is arranged in the upper part of the space in the water tank 214. The air duct 212 is connected to a heater unit 242 for heating the air in the water tank 214.

  A drainage unit 206 is provided below the water tank 214. A drain outlet for draining the washing water is provided in the water tank 214, and the drain outlet is connected to the drain unit 206 via the drain duct 238. The drain unit 206 is provided with a drain valve that is electromagnetically opened and closed (not shown), and drains water from the water tank 214 to the drain hose 202. The drainage unit 206 is provided with a circulation pump 46, and the circulation pump 46 supplies water flowing into the drainage unit 206 via the drainage duct 238 into the water tank 214 again via the circulation hose 204. Specific examples of the water circulation path will be described later.

  The bottom of the water tank 214 is elastically supported by the three dampers 232, and the upper part of the water tank 214 is elastically supported by being connected to the upper part of the outer box 216 by a support spring 236.

  A water supply unit 220 for supplying water into the water tank 214 is provided above the water tank 214, and the water supply unit 220 and the water supply duct 208 are connected to supply water into the water tank 214.

  In addition, mist generator 100 according to the embodiment of the present invention is provided in the upper part of water tank 214. The mist generator 100 is connected to the water supply unit 220 via the mist water supply hose 210.

  A control unit 218 for controlling the entire washing machine 200 is provided at the bottom of the outer box 216.

  FIG. 2 is a diagram illustrating a schematic configuration viewed from the side of washing machine 200 according to the embodiment of the present invention.

  Referring to FIG. 2, an operation panel 36 provided with various operation buttons of washing machine 200 is provided on the upper front side of outer box 216. An outer door 234 is provided on the front side of the outer box.

  A water supply unit 220 that houses the detergent case 222 is provided on the upper surface side of the outer box 216.

  Further, the water supply unit 220 is connected to the water supply valve 42. The water supply duct 208 is connected to the water supply unit 220.

  In addition, a mist water supply valve 44 connected to the water supply unit 220 is provided, and water or the like is supplied to the mist generator 100 by opening the mist water supply valve 44.

  1 and 2 show only the water supply path used for washing for the sake of simplicity of explanation, it is assumed that a water supply path for drying is separately provided in practice. The water supply path for drying is a path through which tap water flows directly to the water supply valve 44 for mist without passing through the water supply unit 220 containing the detergent case 222. Therefore, washing machine 200 in the present embodiment includes a drying water supply valve (not shown), and a drying water supply unit (not shown) provided between drying water valve and mist water supply valve 44. Further prepare. Further, the water in the drying water supply unit (not shown) can be directly supplied to the water tank 214 via the water supply duct 208. In addition, it is good also as supplying water to the water tank 214 from the water supply duct (not shown) different from the water supply duct 208. FIG.

  A drain outlet is provided at the bottom of the water tank 214, and wash water or the like that has flowed out of the water tank 214 flows into the drainage unit 206 through the drainage duct 238. The water flowing through the drain duct 238 is drained from the drain hose 202 by opening the drain valve. Alternatively, the water is supplied to the circulation nozzle 240 via the circulation hose 204 by the circulation pump 46, and water is supplied again from the circulation nozzle 240 provided at the upper end of the water tank 214 into the water supply unit 220. In the present embodiment, for example, the water pumped up through the circulation hose 204 is supplied to the mist generator 100 by opening the mist water supply valve 44 while the circulation pump 46 is ON. Thereby, the water in the water tank 214 can be repeatedly sprayed on the object to be cleaned as a mist.

  For example, a circulation valve (not shown) may be provided between the water supply unit 220 and the circulation nozzle 240. In that case, the valve may be closed so that the water in the water supply unit 220 does not flow backward to the circulation hose 204 while the circulation pump 46 is OFF.

  Moreover, in this Embodiment, although the circulation nozzle 240 was connected to the water supply unit 220, it is not necessarily required, and the circulation nozzle 240 may be directly connected to the mist water supply hose 210, for example. In this case, it is not essential to open the mist water supply valve 44 when the circulation pump 46 is ON.

  A drive mechanism 224 is provided outside the bottom of the water tank 214. The drive mechanism 224 is provided with a drum motor. When the drum motor is driven, a rotary drum (not shown) is driven to rotate.

  FIG. 3 is a schematic diagram illustrating control unit 218 and peripheral devices according to the embodiment of the present invention.

  Referring to FIG. 3, control unit 218 includes a CPU (Central Processing Unit) 60, a vibration unit control unit 62, a timer 64, and a memory 66.

The CPU 60 outputs necessary control instructions to various control parts in the washing machine 200.
The memory 66 stores information necessary for executing the calculation of the CPU 60 and stores a control program necessary for instructing a control instruction for controlling each peripheral device from the CPU.

The timer 64 outputs necessary time information in accordance with an instruction from the CPU 60.
The vibration unit controller 62 outputs an adjustment signal for adjusting the frequency of ultrasonic vibration of the ultrasonic element to the vibration unit 70 in accordance with an instruction from the CPU 60.

  As peripheral devices, here, as an example, an alarm device 40, a water supply valve 42, a mist water supply valve 44, a circulation pump 46, a thermistor 48, a heater 50, and a drying fan are provided in the washing machine 200. 52, a drum motor 54, and a vibration unit 70 are provided, and each peripheral device is controlled by a CPU 60.

  In addition, the CPU 60 outputs a predetermined control signal to each peripheral device in accordance with instructions from various operation buttons provided on the operation panel 36.

  When detecting an abnormality in various peripheral devices, the CPU 60 displays an error on the operation panel 36 and instructs the alarm device 40 to output an alarm sound.

  In addition, the CPU 60 instructs the water supply valve 42 that can be opened and closed electromagnetically (for washing) at a predetermined timing, and supplies water to the water supply unit 220 by opening the water supply valve 42. Then, water or the like is supplied from the water supply unit 220 into the water tank 214 via the water supply duct 208.

  In addition, the CPU 60 instructs the mist water supply valve 44 that can be electromagnetically opened and closed at a predetermined timing, and supplies water and the like from the water supply unit 220 to the mist generator 100 by opening the mist water supply valve 44. To do. Then, by driving the vibration element provided in the vibration unit 70, mist is generated from the mist generator 100, and the generated mist is supplied into the water tank 214. The water supply unit 220 is provided with a detergent case 222 and supplies water in which the detergent is dissolved by passing water through the detergent case 222 to the mist generator 100 via the mist water supply valve 44. To do. Accordingly, since the mist of the detergent water in which the detergent is dissolved is sprayed on the object to be cleaned, it is possible to supply the detergent water uniformly to the entire object to be cleaned.

  Further, the CPU 60 controls the circulation pump 46 provided in the drainage unit 206, and the circulation pump 46 again supplies water or the like from the circulation nozzle 240 into the water supply unit 220 via the circulation hose 204. In the present embodiment, the CPU 60 controls the mist water supply valve 44 to be opened and the water supply valve 42 to be closed when the circulation pump 46 is driven and controlled.

The CPU 60 is connected to the thermistor 48 and detects the temperature in the water tank 214.
Further, the CPU 60 controls the heater 50 that heats the air provided in the heater unit 242 and adjusts the temperature of the heater 50.

  Further, the CPU 60 controls the drying fan 52 provided in the heater unit 242, and supplies the air heated by the heater 50 into the water tank 214 through the blower duct 212 by the rotation of the drying fan 52.

Further, the CPU 60 controls the drum motor 54 to rotate the rotating drum.
In addition, the CPU 60 controls the vibration unit control unit 62, and the vibration unit control unit 62 controls the vibration unit 70 in accordance with an instruction from the CPU 60.

  The vibration unit 70 includes an A / D converter 14, a D / A converter 16, a V / f converter 18, a vibrator 20, a detection circuit 22, a driver 26, a first transistor 28, and a second transistor 30. And a transformer 32 and a coil 34.

  The vibrator 20 is an element that receives ultrasonic power generated by the first transistor 28 and the second transistor 30 and vibrates ultrasonically (vibration with a frequency of 20000 Hz or more). The vibrator 20 according to the present embodiment is a piezoelectric ceramic vibrator.

  The detection circuit 22 includes a detection transformer 51 and a conversion circuit 53. The detection transformer 51 is an element that detects the value of current (also referred to as horn current) flowing through the vibrator 20. The conversion circuit 53 amplifies a current value flowing through the vibrator 20 detected by the detection transformer 51 as a horn current.

  The D / A converter 16 converts a digital signal which is a frequency setting instruction from the vibration unit control unit 62 into an analog signal and outputs the analog signal to the V / f converter 18.

  The V / f converter 18 converts the voltage signal converted into an analog signal by the D / A converter 16 into a frequency signal.

  The driver 26 outputs a PWM signal to the first transistor 28 and the second transistor 30 based on the frequency signal from the V / f converter 18.

  The first transistor 28 and the second transistor 30 are elements (a MOSFET (Metal Oxside Semiconductor Field Effect Transistor) in the present embodiment) that amplifies the PWM signal output from the driver 26.

  The transformer 32 is an element that transforms the voltage of the PWM signal amplified by the first transistor 28 and the second transistor 30. The coil 34 is an element that makes the resonance frequency of the circuit composed of the vibrator 20 and the coil 34 smaller than the resonance frequency of the vibrator 20.

  In the present embodiment, the power supply voltage (+ V) of the vibration unit, the step-up ratio of the transformer 32, and the inductance of the coil 34 are determined through experiments in advance when designing the vibrator 20 to operate satisfactorily.

  The A / D converter 14 converts the analog signal output from the detection circuit 22 into a digital signal and outputs the result to the vibration unit controller 62. In this example, it is assumed that the vibration unit 70 is provided in the mist generator 100 as an example. In particular, some or all of the components constituting the vibration unit 70 are provided in the mist generator 100. It is not necessary and can be provided in the vicinity of the outside thereof, or can be arranged at another location, and the arrangement is not particularly limited.

  FIG. 4 is a diagram illustrating an external configuration of mist generator 100 according to the embodiment of the present invention.

  Referring to FIG. 4, mist generator 100 according to the embodiment of the present invention includes vibrator 20 formed by bonding two piezoelectric bodies 131 and 132, and rear ultrasonic horn 133 bonded to the rear end face thereof. And a front ultrasonic horn 134 joined to the front end face of the vibrator 20.

  Electrodes 135 and 136 are respectively connected to the piezoelectric body 131 and the piezoelectric body 132, and the electrodes 135 and 136 are respectively connected to terminals (+ and −) in the vibration unit 70.

  The rear ultrasonic horn 133 and the front ultrasonic horn 134 are provided in order to amplify the vibration of the vibrator 20 and efficiently propagate the vibration to the front end of the front ultrasonic horn 134. Acts as an ultrasonic horn. These sandwich the piezoelectric bodies 131 and 132 with bolts 137 with a predetermined tightening torque.

  As a material for forming the front ultrasonic horn 134 and the rear ultrasonic horn 133, it is possible to use an alloy such as aluminum, titanium, and stainless steel.

  And mist is produced | generated when water is supplied to the front-end | tip part of the front ultrasonic horn 134, and a front-end | tip part ultrasonically vibrates. The generated mist is sprayed into the water tank 214 outside the mist generator 100.

  In addition, although not shown in figure about each component of the vibration unit 70 other than the vibrator | oscillator 20, in this example, it shall be provided in the mistake and the generator 100 as an example.

  FIG. 5 is a diagram for explaining the frequency characteristics of the vibrator 20 (piezoelectric ceramic vibrator) according to the present embodiment.

  Referring to FIG. 5, the vertical axis represents impedance, and the horizontal axis represents the frequency of vibrator 20.

  The frequency characteristics of the vibrator 20 (piezoelectric ceramic vibrator) are as follows. When the frequency given to the piezoelectric ceramic vibrator is the resonance frequency f (1) (in this embodiment, the value of the resonance frequency is 39.50 kHz), The impedance of the piezoelectric ceramic vibrator is minimized.

  Further, when the frequency applied to the vibrator 20 (piezoelectric ceramic vibrator) is the antiresonance frequency f (2) (in this embodiment, the value of the antiresonance frequency is 40.10 kHz), Impedance is maximized.

  In the case of using the vibrator 20 (piezoelectric ceramic vibrator), as described above, the frequency characteristics (resonance frequency f (1), anti-resonance frequency f (2), impedance, etc.) even if the piezoelectric ceramic vibrator has the same specifications. ) Varies from vibrator to vibrator, and the frequency characteristics of the piezoelectric ceramic vibrator change over time.

Therefore, it is necessary to execute optimal vibration control for each vibrator.
<Mist control sequence>
Here, FIG. 6 shows a mist control sequence in washing machine 200 in the present embodiment.

  Referring to FIG. 6, in the washing process (washing period) of the standard course, “water supply”, “familiarize”, “make-up water (1)”, “wash (1)”, “make-up water (2)”, “Washing (2)”, “Replenishing water (3)”, “Washing (3)”, and “Draining” are sequentially executed. Thereafter, the process proceeds to a rinsing process.

  In the present embodiment, the circulation pump 46 is turned on in the blending and each washing process (the period of such a process is referred to as a “washing period”), and the wet mist control is performed while the circulation pump 46 is on. Executed. In order for the mist generated by the mist generator 100 to spread over a wide range of the object to be cleaned during the cleaning period, water is supplied only to the extent that a part of the object to be cleaned is immersed.

  Note that, as shown in FIG. 6, in “wash 3”, the circulation pump 46 may be switched ON / OFF at predetermined intervals. This is because the object to be cleaned is considered to be sufficiently wet at this point, and it is not always necessary to spray water that has been misted (water in which the detergent is dissolved) during the washing period. For example, in the standard course, during the “wash 3” period, the ON period “j1” is 14 minutes and the OFF period “j2” is 22 minutes, and this is repeated.

  FIG. 7 is a timing chart of the wet mist control. FIG. 6 shows the timing of the frequency adjustment control in the period when the wet mist control is ON in FIG.

  Referring to FIG. 7, when circulation pump 46 is turned on, wet mist control is started. When the period of wet mist control is expressed as “Twm”, this period Twm is a period predetermined for each course (standard, extraordinary, etc.) and process (washing 1, washing 2, etc.). For example, if it is a period of “wash 1” of the standard course, the period Twm is, for example, 5 minutes.

  In FIG. 7, of the frequency adjustment control (tuning) of the vibrator 20, the time required for optimal value search control is represented by “TA”, and the control period based on the optimum value is represented by “TB”. During the control period TB, the vibrator 20 is driven at the optimum value, so that mist is generated satisfactorily (sufficiently). In the control period TB, it is also possible to change the load due to the detergent water, so it is preferable to execute error monitoring control. The error monitoring control may be a tuning process similar to the search control.

  Since the control period Twm is fixed as described above, the optimum control period TB becomes longer as the search control time TA is shorter. That is, if the optimum frequency is searched for early, the period during which mist is suitably generated becomes longer. Therefore, it can be said that it is an indispensable condition to end the frequency adjustment control at an early stage in order to improve the cleaning accuracy of the object to be cleaned.

  Therefore, the following processing is performed in the present embodiment. That is, as shown in FIG. 7, the search control is not started until a predetermined time, for example, 2 seconds elapses after the start of the wet mist control. Thus, in the present embodiment, the search control is not performed simultaneously with the start of the wet mist control, but is performed after a predetermined time has elapsed. This predetermined time represents the time required from when the circulation pump 46 is driven to when water is supplied to the tip of the front ultrasonic horn 134 of the transducer 20 and is predetermined. . Thereby, the search control can be started in a state where the load on the vibrator 20 is substantially constant. As a result, the search control can be terminated early. That is, it is possible to search for the optimum frequency of the vibrator 20 in a short period.

  By the way, when the control period Twm ends (that is, when the frequency adjustment control is ended because a predetermined time has elapsed since the start of the wet mist control), when the driving of the vibrator 20 is stopped immediately, the vibrator 20 is operated at the optimum frequency. Will stop driving. As a result, an excessive current may flow through the control circuit of the vibrator 20 and the circuit may break down. For this reason, in the present embodiment, as the stop control of the vibrator 20, the process of stopping the drive is performed after the horn current is reduced. Specifically, for example, control is performed to increase the frequency of the vibrator 20 to a value near the anti-resonance frequency (for example, a predetermined value or a value within a predetermined range). Such a stop control period is represented by a period “TC” in FIG.

  In the present embodiment, it is assumed that the circulation pump 46 remains ON even during the stop control period TC. That is, it is preferable that water is supplied to the front end portion of the front ultrasonic horn 134 of the vibrator 20 even during the stop control period TC. By doing so, the heat of the horn generated by the oscillation can be cooled.

  In FIG. 7, the driving of the vibrator 20 is started together with the start of the frequency adjustment control (search control). However, the driving of the vibrator 20 may be performed from the start of the wet mist control.

  The wet mist control period Twm is fixed for each combination of course and process. For example, when an error is determined a predetermined number of times, the wet mist control may be performed again after the elapsed time is reset.

  The washing machine 200 in the present embodiment may perform mist water supply control during the “water supply” period shown in FIG. 6. Specifically, the mist may be controlled during washing water supply, and water supply by mist may be performed in addition to normal water supply.

FIG. 8 is a timing chart of mist water supply control.
Referring to FIG. 8, at the same time as the drying water supply valve (not shown) is opened, the mist water supply valve 44 is also opened, and the mist water supply control is executed. Even in the mist water supply control, the search control is not started immediately, but is started after a predetermined time, for example, 2 seconds, as in the above-described wet mist control. As a result, similarly to the above, since the search control can be started in a state where the load on the vibrator 20 is constant, the search control can be ended early.

  Also, in the mist water supply control, as in the wet mist control, when the frequency adjustment control (optimum control) is finished, the driving of the vibrator 20 is not stopped immediately, but the frequency is increased to near the anti-resonance frequency. The drive of the vibrator 20 is stopped. Thereby, the failure of the circuit of the vibrator 20 can be prevented in the same manner as described above.

  In this way, by performing mist water supply in parallel with the initial water supply, the object to be cleaned can be moistened as a whole at the initial stage. As a result, the cleaning efficiency of the object to be cleaned can be improved.

  In the rinsing process performed after the washing process shown in FIG. 6, the process shown in FIG. 7 may be performed.

<About operation>
Next, the mist output control executed in the mist control period (for example, the period Twm in FIG. 7) and the mist stop control executed after the mist control period will be described in detail.

(Mist output control)
FIG. 9 is a flowchart illustrating control of the vibrator for executing mist output control according to the embodiment of the present invention. In the following description, the wet mist control (mist control in each cleaning period) shown in FIG. 7 is assumed. However, unless otherwise noted, the mist water supply control shown in FIG. 8 is also applicable.

  Referring to FIG. 9, first, water is supplied to the ultrasonic horn (step S1). Specifically, the CPU 60 opens the mist water supply valve 44 at the same time as starting to drive the circulation pump 46. Thereby, the water in the water tank 214 is supplied to the water supply unit 220 via the circulation hose 204. Then, the water in which the detergent is dissolved is supplied from the mist water supply hose 210 to the tip of the front ultrasonic horn 134. Thus, during wet mist control, water is supplied to the mist generator 100 by the circulation pump 46, the circulation hose 204, the water supply unit 220, the water supply valve 44, and the like.

  In the case of the mist water supply control shown in FIG. 8, the CPU 60 controls the drying water supply valve (not shown) and the mist water supply valve 44 to open both. Thereby, tap water is supplied from the mist water supply hose 210 to the tip of the front ultrasonic horn 134. In this way, in the water supply mist control, water is supplied to the mist generator 100 by the drying water supply valve (not shown), the drying water supply unit (not shown), the mist water supply valve 44, and the like. .

  Then, it is determined (detected) whether or not the water supply to the horn is completed (step S2). If it is determined in step S2 that the water supply to the horn has been completed, the process proceeds to step S3. Specifically, the determination is made based on whether or not a predetermined time has elapsed from when the mist water supply valve 44 is opened until the front ultrasonic horn 134 is supplied with water through the mist water supply hose 210. It is possible.

  In the present embodiment, it is determined whether or not the water supply to the horn has been completed based on a predetermined time by an experiment or the like, but the vibrator 20 (specifically, the front ultrasonic horn 134). As long as the water supply to the tip of the water can be detected, the determination is not limited to time.

The following processing is mainly processing in the vibration unit control unit 62.
In step S3, an initial setting process is executed.

FIG. 10 is a flowchart for explaining the initial setting process.
Referring to FIG. 10, first, as an initial setting process, the frequency is set to the upper limit value on the high frequency side (step S21).

Specifically, the vibration unit controller 62 sets the frequency in the vicinity of the anti-resonance frequency.
Next, the tuning mode is set to a reduction mode that is a mode for reducing the frequency (step S22).

  Next, frequency output processing is started (step S23). Specifically, the vibration unit control unit 62 controls the vibration unit 70 to vibrate at the set vibration frequency of the upper limit value on the high frequency side.

Then, the initial setting process ends (END).
Referring again to FIG. 9, next, a pre-tuning confirmation process is executed (step S4).

FIG. 11 is a flowchart for explaining the pre-tuning confirmation process.
Referring to FIG. 11, first, the horn current is detected (step S30). Specifically, the vibration unit controller 62 receives the input of the horn current detected by the detection circuit 22.

  Next, it is determined whether or not a time of 32 msec has elapsed (step S31).

  The detection of the horn current in step S30 is repeated until the time of 32 msec elapses. Accordingly, a plurality of horn current values are input to the vibration unit controller 62 until the time of 32 msec has elapsed. Whether or not 32 msec has elapsed is measured using the timer 64. The same applies to the following time passage determination processing.

Next, the average value of the horn current Ih is calculated (step S32).
It is assumed that horn current detection requires 2 msec per time. Therefore, it is assumed that 16 horn currents can be detected during a time of 32 msec.

Then, the average value of the 16 horn currents is calculated as the horn current Ih.
Next, the currently calculated horn current Ih and the previously calculated horn current Ih # are compared, and it is determined whether or not the absolute value of the difference is equal to or less than a predetermined threshold value.

  Specifically, it is determined whether or not the condition of −50 mA <Ih−Ih # ≦ 50 mA is satisfied (step S34).

  That is, if it is determined that the difference between the current calculated horn current and the previous calculated horn current is small, that is, there is almost no fluctuation, the pre-tuning confirmation process is terminated (step S35). Go to the next step. When there is no horn current Ih # calculated last time, a preset initial value is set.

  On the other hand, in step S34, the condition of −50 mA <Ih−Ih # ≦ 50 mA is not satisfied, that is, the difference between the currently calculated horn current and the previously calculated horn current is large, in other words, the fluctuation. Is determined to be large, the horn current Ih is set to the previously calculated horn current Ih # (step S36).

Then, it is determined whether or not 1 sec has elapsed (step S37).
If the time of 1 sec has not elapsed, the process returns to step S30 again and the above processing is repeated.

  On the other hand, if it is determined in step S37 that the fluctuation of the horn current is large even when the time of 1 sec has elapsed, the horn current is not stable, so it is determined to be abnormal, and error processing is performed (step S38). . And it progresses to step S9 mentioned later.

  Referring to FIG. 9 again, after the pre-tuning confirmation process is completed, a tuning mode start process is executed (step S5).

  Specifically, in this example, as an example, one of the tuning modes of the reduction mode, the increase mode, and the fine adjustment mode in which the frequency is adjusted based on the detected horn current value is executed.

  The reduction mode is a mode when tuning is performed in a direction of lowering the frequency by the previous tuning.

  The ascending mode is a mode when tuning is performed in the direction of increasing the frequency by the previous tuning.

  The fine adjustment mode is a mode in which it is not necessary to adjust the frequency by the previous tuning or the frequency is finely adjusted.

  In this example, the frequency is tuned so that a horn current greater than 340 mA and less than 360 mA is detected as the frequency target range.

FIG. 12 is a flowchart for explaining processing in the reduction mode as the tuning mode.
FIG. 13 is a flowchart for explaining processing in the ascending mode as the tuning mode.

FIG. 14 is a flowchart for explaining processing in the fine adjustment mode as the tuning mode.
(Reduction mode)
Referring to FIG. 12, in the reduction mode process, first, the currently calculated horn current Ih is compared with the value obtained by subtracting 50 mA from the previously calculated horn current Ia #, and this time the calculated horn current Ih is calculated. It is determined whether or not the horn current Ih is equal to or greater than a value obtained by subtracting 50 mA from the previously calculated horn current Ia #. As an example, the initial value of the horn current Ia # is set to a horn current value corresponding to the anti-resonance frequency at which the impedance of the piezoelectric ceramic vibrator is maximum. That is, the current value is set to the minimum value.

  Specifically, it is determined whether or not the condition of Ih ≧ Ia # −50 mA is satisfied (step S40). The comparison with the value obtained by subtracting 50 mA from the previously calculated horn current Ia # is based on the offset as the fluctuation of the current value.

  That is, if it is determined that the currently calculated horn current is equal to or greater than the value calculated by subtracting 50 mA from the previously calculated horn current Ia #, the process proceeds to step S41. In other words, the current calculated horn current and the previously calculated horn current Ia # are compared to determine whether the current calculated horn current value has increased by reducing the frequency. If it is determined that the frequency has increased, the frequency is determined to be within the range of the resonance frequency and the anti-resonance frequency.

  In step S41, it is determined whether or not the currently calculated horn current value Ih is 100 mA or less.

  In step S41, when the currently calculated horn current value Ih is 100 mA or less, the frequency is subtracted by 350 Hz (step S42). When it is determined that the horn current value Ih is small, the current frequency is considered to be in the vicinity of the anti-resonance frequency (f (2)), so the frequency is tuned greatly.

Then, the tuning state is set to the reduction mode (step S43).
Next, the calculated horn current Ih is set to the previous horn current Ia # (step S44).

  Then, the process ends (END). By this processing, it is possible to approach the target frequency corresponding to a horn current of greater than 300 mA and less than 360 mA from the antiresonance frequency side.

  In step S41, if the currently calculated horn current value Ih is greater than 100 mA, it is next determined whether or not the currently calculated horn current value Ih is greater than 100 mA and not greater than 300 mA. Judgment is made (step S45).

  In step S45, if the currently calculated horn current value Ih is greater than 100 mA and less than or equal to 300 mA, then the frequency is subtracted by 70 Hz (step S46). When the horn current value Ih is slightly smaller than the target value, the current frequency is considered to be slightly higher than the target frequency, and the frequency is tuned to be small.

  Then, the tuning state is set to the reduction mode (step S43), the currently calculated horn current Ih is set to the previous horn current Ia # (step S44), and the process ends (end). By this processing, it is possible to approach the target frequency corresponding to a horn current of greater than 300 mA and less than 360 mA from the antiresonance frequency side.

  On the other hand, in step S45, if the currently calculated horn current value Ih is greater than 100 mA and not less than 300 mA, that is, greater than 300 mA, then the presently calculated horn current value Ih. Is greater than 300 mA and less than 400 mA (step S47).

  In step S47, if the currently calculated horn current value Ih is greater than 300 mA and less than or equal to 400 mA, the tuning state is set to the fine adjustment mode (step S48). Then, the horn current Ih calculated this time is set to the previous horn current Ia # (step S44), and the process ends (end). If it is determined by the processing that the current frequency is near the target frequency, the frequency is finely adjusted in a fine adjustment mode to be described later, so that the horn is larger than 300 mA from the antiresonant frequency side and lower than 360 mA. It can be made closer to the frequency of the target corresponding to the current.

  On the other hand, in step S47, if the currently calculated horn current value Ih is greater than 300 mA and not less than 400 mA, that is, greater than 400 mA, then the presently calculated horn current value Ih. Is greater than 400 mA and less than 450 mA (step S49).

  If the currently calculated horn current value Ih is greater than 400 mA and 450 mA or less in step S49, then the frequency is added by 70 Hz (step S50). When the horn current value Ih is slightly larger than the target value, the current frequency is considered to be slightly smaller than the target frequency, and the frequency is tuned to be small.

  Then, the tuning state is set to the ascending mode (step S51), the currently calculated horn current Ih is set to the previous horn current Ia # (step S44), and the process ends (end). By this processing, it is possible to approach the target frequency corresponding to a horn current of greater than 300 mA and less than 360 mA from the antiresonance frequency side.

  On the other hand, if the currently calculated horn current value Ih is greater than 400 mA and not less than 450 mA in step S49, error processing is performed (step S57). Then, the process ends (END). In this case, an abnormal current flows as the horn current, and it is determined that an uncontrollable current flows, so that error processing is performed.

  On the other hand, if it is determined in step S40 that the currently calculated horn current value is smaller than the value obtained by subtracting 50 mA from the previously calculated horn current Ia #, the process proceeds to step S52. That is, the current calculated horn current is compared with the previously calculated horn current Ia # to determine whether the current calculated horn current value has increased by reducing the frequency. When it is determined that the current value has decreased, it is considered that the frequency has become lower than the resonance frequency. In this case, it is determined how much the frequency has decreased from the resonance frequency according to the horn current value.

  In step S52, it is determined whether or not the currently calculated horn current value is 250 mA or less.

  If it is determined in step S52 that the currently calculated horn current value is 250 mA or less, then the frequency is added by 350 Hz (step S53).

  Then, the tuning state is set to the ascending mode (step S56), the currently calculated horn current Ih is set to the previous horn current Ia # (step S44), and the process ends (end).

  On the other hand, if the currently calculated horn current value is greater than 250 mA in step S52, then whether or not the currently calculated horn current value Ih is greater than 250 mA and equal to or less than 450 mA. Is determined (step S54).

  In step S45, if the currently calculated horn current value Ih is greater than 250 mA and less than 450 mA, then the frequency is added by 100 Hz (step S55).

  Then, the tuning state is set to the ascending mode (step S56), the currently calculated horn current Ih is set to the previous horn current Ia # (step S44), and the process ends (end).

  In steps S52 and S54 described above, the horn current value is divided into a case where the horn current value is 250 mA or less and a case where the horn current value is greater than 250 mA and 450 mA or less. As shown in FIG. 5, the frequency characteristics of the vibrator 20 in the case of a frequency smaller than the resonance frequency have a smaller impedance at a frequency close to the resonance frequency, and a larger impedance at a frequency farther than the resonance frequency. Therefore, when the value of the horn current is 250 mA or less, it is considered that the frequency is far from the resonance frequency. Therefore, when the frequency is tuned greatly, and the value of the horn current is greater than 250 mA and 450 mA or less. Since the frequency is considered to be close to the resonance frequency, the frequency is tuned small.

  On the other hand, if the currently calculated horn current value Ih is greater than 250 mA and not less than 450 mA in step S54, error processing is performed (step S57). Then, the process ends (END). In this case, an abnormal current flows as the horn current, and it is determined that an uncontrollable current flows, so that error processing is performed.

(Rise mode)
Referring to FIG. 13, in the ascending mode process, first, the currently calculated horn current Ih is compared with the value obtained by adding 50 mA from the previously calculated horn current Ia #, and this time calculated. It is determined whether or not the horn current Ih is equal to or less than a value obtained by adding 50 mA from the previously calculated horn current Ia #.

  Specifically, it is determined whether or not the condition of Ih ≦ Ia # + 50 mA is satisfied (step S60). The comparison with the value obtained by adding 50 mA from the previously calculated horn current Ia # is due to the offset taken into account as the fluctuation of the current value.

  That is, it is determined whether or not the currently calculated horn current is less than a value obtained by adding a predetermined value from the previously calculated horn current, and the currently calculated horn current value is the previously calculated horn current. If it is determined that the value is equal to or less than the value obtained by adding 50 mA from Ia #, the process proceeds to step S61. In other words, the current calculated horn current is compared with the previously calculated horn current Ia # to determine whether the current calculated horn current value has decreased by increasing the frequency. If it is determined that the frequency has decreased, the frequency is determined to be within the range of the resonance frequency and the anti-resonance frequency.

  On the other hand, if it is determined in step S60 that the value of the horn current calculated this time is larger than the value obtained by adding 50 mA from the previously calculated horn current Ia #, the process proceeds to step S72 to perform error processing. . Then, the process ends (END). That is, the current calculated horn current is compared with the previously calculated horn current Ia # to determine whether the current calculated horn current value has decreased by increasing the frequency. When it is determined that the current value has increased, it is considered that the frequency has become higher than the antiresonance frequency. In this case, since the frequency is greatly deviated from the target frequency range, error processing is performed.

  Since the processes in steps S61 to S71 are the same as the processes described in steps S41 to S51 described in FIG. 12, detailed description thereof will not be repeated. That is, the frequency is tuned based on the horn current value.

  In step S69, if the currently calculated horn current value Ih is larger than 450 mA, error processing is performed (step S72). Then, the process ends (END). In this case, an abnormal current flows as the horn current, and it is determined that an uncontrollable current flows, so that error processing is performed.

(Fine adjustment mode)
Referring to FIG. 14, in the fine adjustment mode process, first, it is determined whether or not the currently calculated horn current Ih is 100 mA or less (step S82).

  If it is determined in step S82 that the current is 100 mA or less, error processing is performed (step S83). Then, the process ends (END). In any of the reduction mode, the ascending mode, and the fine adjustment mode, if the horn current Ih is not larger than 100 mA, the fine adjustment mode is not set. Therefore, when the calculated horn current value is 100 mA or less. It is considered that a failure has occurred, and it is determined that error processing has occurred.

  On the other hand, if it is determined in step S82 that the current is not less than 100 mA, that is, if the current calculated horn current value Ih is larger than 100 mA in step S82, then the current calculated horn current is It is determined whether or not the value Ih is larger than 100 mA and smaller than 280 mA (step S84).

  In step S84, when the currently calculated horn current value Ih is greater than 100 mA and equal to or less than 280 mA, the frequency is subtracted by -170 Hz (step S85). When the horn current value Ih is slightly smaller than the target value, the current frequency is considered to be slightly higher than the target frequency, and the frequency is tuned to be small.

  Then, the tuning state is set to the reduction mode (step S86), the currently calculated horn current Ih is set to the previous horn current Ia # (step S87), and the process is ended (END).

  On the other hand, in step S84, if the currently calculated horn current value Ih is greater than 100 mA and not less than 280 mA, that is, greater than 280 mA, then the presently calculated horn current value Ih. Is greater than 280 mA and less than 340 mA (step S88).

  In step S88, if the currently calculated horn current value Ih is greater than 280 mA and less than or equal to 340 mA, then the frequency is subtracted by -17 Hz (step S89). When the value Ih of the horn current is slightly smaller than the target value, the current frequency is considered to be slightly larger than the target frequency, so that the frequency is finely tuned.

  Then, the tuning state is set to the fine adjustment mode (step S90). Then, the process ends (END). By this processing, it is possible to gradually approach the frequency of the target corresponding to the horn current larger than 340 mA and 360 mA or less from the antiresonance frequency side.

  On the other hand, in step S88, if the currently calculated horn current value Ih is greater than 280 mA and not less than 340 mA, that is, greater than 340 mA, then the presently calculated horn current value Ih. Is greater than 340 mA and less than 360 mA (step S91).

  In step S91, if the currently calculated horn current value Ih is greater than 340 mA and less than 360 mA, the tuning state is set to the fine adjustment mode without adding or subtracting the frequency (step S90). ). Then, the process ends (END). Since the current frequency is included in the target frequency range, tuning is performed so that the frequency is included in the frequency range. When the horn current value Ih is determined to be greater than 340 mA and less than 360 mA for the first time after the wet mist control is started, the search control (optimum value search mode) shown in FIG. 7 is terminated. Thereafter, the fine adjustment mode is continued, whereby the error monitoring control, that is, the optimum control shown in FIG. 7 is executed.

  On the other hand, if the currently calculated horn current value Ih is greater than 340 mA and not less than 360 mA, that is, greater than 360 mA in step S91, then the presently calculated horn current value Ih. Is greater than 360 mA and less than or equal to 400 mA (step S92).

  In step S92, if the currently calculated horn current value Ih is greater than 360 mA and less than or equal to 400 mA, the frequency is added by 17 Hz (step S93). When the horn current value Ih is slightly larger than the target value, the current frequency is considered to be slightly smaller than the target frequency, and the frequency is finely tuned.

  Then, the tuning state is set to the fine adjustment mode (step S90). Then, the process ends (END). By this processing, it is possible to gradually approach the frequency of the target corresponding to the horn current larger than 340 mA and 360 mA or less from the antiresonance frequency side.

  On the other hand, in step S92, if the currently calculated horn current value Ih is greater than 360 mA and not less than 400 mA, that is, greater than 400 mA, then the presently calculated horn current value Ih. Is greater than 400 mA and less than 460 mA (step S94).

  In step S94, when the currently calculated horn current value Ih is greater than 400 mA and equal to or less than 460 mA, the frequency is added by 50 Hz (step S95). When the horn current value Ih is slightly larger than the target value, the current frequency is considered to be slightly smaller than the target frequency, and the frequency is tuned to be small.

  Then, the tuning state is set to the ascending mode (step S96), the currently calculated horn current Ih is set to the previous horn current Ia # (step S87), and the process ends (end).

  On the other hand, if the calculated horn current value Ih is greater than 400 mA and not less than 460 mA in step S94, error processing is performed (step S97). Then, the process ends (END). In this case, an abnormal current flows as the horn current, and it is determined that an uncontrollable current flows, so that error processing is performed.

  Referring to FIG. 9 again, in step S5, after any one of the reduction mode, the increase mode, and the fine adjustment mode as the tuning mode is executed, it is next determined whether or not the error processing is set (step S6).

If it is an error process in step S6, the process proceeds to step S9.
Then, it is determined whether or not the error processing has been executed a predetermined number of times (step S9).

  If it is determined in step S9 that the error process has not been performed a predetermined number of times, the process proceeds to step S3 again, and the processes in steps S3 to S6 are repeated again to determine whether or not the error process has occurred.

  If the error process is executed a predetermined number of times in step S9, the stop process is executed because the error continues (step S10). That is, the vibration unit control unit 62 instructs the vibration unit 70 to stop the ultrasonic vibration of the vibrator 20.

  If it is determined in step S6 that it is not an error process, it is next determined whether or not the tuning is completed (step S8).

  If the tuning is not finished, the process returns to step S4 again, and the processes of steps S4 to S8 are repeated until the tuning is finished.

  Specifically, the vibration unit control unit 62 continuously performs tuning while controlling the vibrator 20 in the vibration unit 70, and instructs to stop the mist output control according to the instruction from the CPU 60. Is input, it is determined that the tuning is completed, and the process is terminated (END).

  In the present embodiment, the mist stop control shown in FIG. 15 is started simultaneously with the end of the mist output control.

  In the method according to the embodiment of the present invention, three modes of the reduction mode, the ascending mode, and the fine adjustment mode are executed, and as an example, the frequency of the target at which a horn current greater than 340 mA and less than 360 mA is detected is detected. Tune.

  When tuning each mode, a pre-tuning confirmation process (step S4) is executed for each mode tuning.

  As described above, in the confirmation process before tuning, an average value of 16 horn currents is calculated during a time of 32 msec, and a difference from the average value of horn currents during the previous 32 msec is calculated. When it is determined that the current difference is small, that is, there is almost no fluctuation, tuning processing based on the horn current is executed.

  By executing the pre-tuning confirmation process before starting the tuning mode, the tuning process can be performed based on the result of the sudden current fluctuation, and the tuning process based on the stable horn current can be performed with high accuracy. Tuning processing can be executed.

  In addition, since the tuning process is executed based on the frequency characteristics of the vibrator 20, a highly accurate tuning process can be executed.

  In the confirmation process before tuning, the time of 32 msec is given as an example, but the above time is an example, and can be designed freely. Moreover, although the case where the average of the detection result of 16 times was calculated in order to calculate a horn current was demonstrated, it is not restricted to especially 16 times, It is possible to design freely. Although the threshold value is set to 50 mA, it is not limited to this value and can be set to an optimum value.

(Mist stop control)
FIG. 15 is a flowchart illustrating control of the vibrator for executing mist stop control according to the embodiment of the present invention. As described above, this control is started simultaneously with the end of the mist output control. The mist output control is terminated when, for example, a predetermined period (period Twm) has elapsed from the start of the mist output control (wet mist control).

  Referring to FIG. 15, first, the vibration unit controller 62 adds a frequency of 500 Hz (step S102). Next, it is determined whether or not the frequency has reached an upper limit value on the high frequency side, that is, a value near the anti-resonance frequency (step S104). The upper limit value here may be, for example, the initial frequency of mist output control. That is, it may be the upper limit value set in step S21 of FIG. Here, it is determined whether or not the value is a predetermined upper limit value, but it may be determined whether or not the value is within a predetermined range near the anti-resonance frequency.

  If it is determined that the frequency has not reached the upper limit on the high frequency side (NO in step S104), it is determined whether 50 msec has elapsed (step S106). Wait until 50 msec elapses (NO in step S106). If it is determined that elapses (YES in step S106), the process returns to step S102.

  Thus, the frequency is increased in units of, for example, 500 Hz until the frequency reaches a value near the anti-resonance frequency (a predetermined value). In the mist output control described above, the frequency is gradually and gradually reduced from a value near the anti-resonance frequency (predetermined value), whereas in the mist stop control, a width larger than the frequency adjustment width in the mist output control. The frequency is raised.

  On the other hand, when it is determined in step S104 that the frequency has reached the upper limit on the high frequency side (YES in step S104), for example, after waiting for 100 msec (step S108), the frequency output is stopped (step S110). ). Specifically, driving of the vibrator 20 is stopped.

  Further, water supply to the horn is stopped (step S112). That is, the driving of the circulation pump 46 is stopped and the mist water supply valve 44 is closed.

  The water supply stop to the horn may be executed immediately after it is determined in step S104 that the frequency has reached the upper limit on the high frequency side.

  As described above, in this embodiment, since the drive of the vibrator 20 is stopped after the frequency reaches a value near the anti-resonance frequency (predetermined value), the current hardly flows to the control circuit of the vibrator 20. The driving of the vibrator 20 can be stopped. Thereby, failure (damage) of the control circuit of the vibrator 20 can be prevented.

  In the present embodiment, the water of the horn generated by the oscillation can be cooled by supplying water to the front ultrasonic horn 134 while the vibration frequency of the vibrator 20 is detected.

  Similar to the mist output control, when the frequency approaches the upper limit value on the high frequency side, the interval for increasing the frequency may be narrowed.

  In addition, the washing machine 200 in this Embodiment may perform dry mist control at a drying process. Dry mist control is performed to reduce wrinkles in the second half of the drying process. That is, dry mist control represents control for spraying mist on clothes once dried. Also in such dry mist control, the same processing as the wet mist control may be executed.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

It is a figure explaining the schematic structure seen from the front side of the washing machine according to embodiment of this invention. It is a figure explaining the schematic structure seen from the side surface side of the washing machine according to embodiment of this invention. It is the schematic explaining the control part and peripheral device according to embodiment of this invention. It is a figure explaining the external appearance structure of the mist generator according to embodiment of this invention. It is a figure explaining the frequency characteristic of a vibrator (piezoelectric ceramic vibrator) concerning an embodiment of the invention. It is a figure which shows the mist control sequence in embodiment of this invention. It is a timing chart of wet mist control. It is a timing chart of mist water supply control. It is a flowchart explaining control of a vibrator for performing mist output control according to an embodiment of the present invention. It is a flowchart explaining an initial setting process. It is a flowchart explaining the pre-tuning confirmation process. It is a flowchart explaining the process of reduction mode as tuning mode. It is a flowchart explaining the process of a raise mode as tuning mode. It is a flowchart explaining the process of fine adjustment mode as tuning mode. It is a flowchart explaining control of the vibrator for performing mist stop control according to an embodiment of the invention.

Explanation of symbols

  20 vibrator, 36 operation panel, 40 alarm device, 42 water supply valve, 44 water supply valve for mist, 46 circulation pump, 48 thermistor, 50 heater, 52 drying fan, 54 drum motor, 70 vibration unit, 100 mist generator, 200 Washing machine, 202 drainage hose, 204 circulation pump, 206 drainage unit, 208 water supply duct, 210 mist water supply hose, 212 air duct, 214 water tank, 216 outer box, 218 control unit, 220 water supply unit, 230 inner door, 232 damper, 236 support spring, 238 drainage duct, 240 circulation nozzle, 242 heater part.

Claims (5)

Mist generating means including an ultrasonic element for ultrasonic vibration, and spraying the supplied liquid in a mist form according to the ultrasonic vibration of the ultrasonic element;
Driving means for driving the ultrasonic element;
Water supply means for supplying water to the mist generating means;
Control means for performing control for washing the article to be cleaned,
The control means includes
Water supply control means for controlling the water supply means;
Adjustment control means for performing adjustment control for adjusting the frequency at which the ultrasonic element vibrates ultrasonically with respect to the drive means when water is supplied to the mist generation means,
The adjustment control means adjusts the frequency within a range of a resonance frequency where the impedance of the ultrasonic element is low and an anti-resonance frequency where the frequency is higher than the resonance frequency and the impedance of the ultrasonic element is high. And searching for a specific frequency representing the optimum frequency, and performing control to maintain the searched specific frequency,
The control means further includes a stop control means for stopping the driving of the driving means after setting the frequency to a value near the anti-resonance frequency when the adjustment control is finished,
The said water supply control means is a washing machine which stops the water supply to the said mist production | generation means at the timing when the drive of the said drive means is stopped. The adjustment control means adjusts the frequency so as to approach the resonance frequency side from the anti-resonance frequency side,
The washing machine according to claim 1, wherein the stop control means performs control to return the specific frequency to a value near the anti-resonance frequency.   The washing machine according to claim 1 or 2, wherein the value near the anti-resonance frequency corresponds to an initial value of frequency adjustment in the adjustment control.   The stop control means adds the frequency stepwise with a width larger than the frequency adjustment width in the adjustment control, and determines that the frequency has reached a value near the anti-resonance frequency. The washing machine according to claim 2, wherein the driving of the washing machine is stopped. A current detecting means for detecting a current flowing through the ultrasonic element;
The washing machine according to any one of claims 1 to 4, wherein the adjustment control unit adjusts a frequency based on a current value detected by the current detection unit.

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