JP2017209407A - Washing machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize a washing machine which does not require additional cost for components, which can bring the time of DC excitation performed when starting the rotation of a brushless motor to necessary minimum, and which does not make operation time of the washing machine unnecessarily long.SOLUTION: A washing machine includes a control device 7 for controlling: an inverter driven brushless motor 4 for driving a washing tub 3 and an agitation blade 2 provided at an inside bottom part of the washing tub 3 in a rotatable manner; water supply means 6 for supplying water; and drain means 5 for draining water. The washing machine has time for performing DC excitation with respect to the brushless motor 4 when starting the rotation of the brushless motor 4 by the control device 7, and the time for performing the DC excitation changes according to the magnitude of torque applied to the brushless motor 4. Thus, the time of DC excitation performed when starting the rotation of the brushless motor 4 can be shortened without requiring additional cost for components.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a washing machine that drives a motor by an inverter circuit.

  Conventionally, as a motor used in a washing tub of a washing machine, a brushless motor has been adopted in order to improve cleaning ability, and this is driven by an inverter circuit.

  On the other hand, a control device that drives a brushless motor without using a position sensor has been considered in order to reduce the cost of the washing machine (see, for example, Patent Document 1).

  FIG. 2 is a block diagram of the motor control device for the washing machine according to the first embodiment of the present invention. Since the conventional motor control device for the washing machine is also expressed in a similar manner, FIG. 2 is referred to. A conventional motor control device for a washing machine will be described.

  As shown in FIG. 2, the control device 7 is driven by a rectifier circuit 71 connected to a power source 8, an inverter circuit 72 that converts DC power of the rectifier circuit 71 into AC power, and drives a washing tub and the like. The brushless motor 4, the current detection means 73 for detecting the motor current of the brushless motor 4, the voltage detection means 74 for detecting the voltage input to the inverter circuit 72, and the motor current detected by the current detection means 73 as the magnetic flux of the rotor. Current converting means 76 for converting the current component in the direction and the current component perpendicular to the magnetic flux direction of the rotor, the current component in the magnetic flux direction of the rotor, the current component perpendicular to the magnetic flux direction of the rotor, and the voltage detected by the voltage detecting means 74. Rotor position detection means 77 for calculating the rotor angle of the brushless motor 4 and the rotor speed of the brushless motor 4, and rotor position detection Using the rotor speed of the brushless motor 4 calculated by the means 77, the speed control means 78 for calculating the current command corresponding to the torque command by performing the speed control, the current command corresponding to the torque command and the current conversion means 76 converted. Current control means for performing current control using a current component corresponding to the magnetic flux direction of the rotor and a current component perpendicular to the magnetic flux direction of the rotor to calculate a voltage command in the magnetic flux direction of the rotor and a voltage command perpendicular to the magnetic flux direction of the rotor 79, and a voltage conversion means 75 that converts a voltage command in the direction of the magnetic flux of the rotor and a voltage command perpendicular to the direction of the magnetic flux of the rotor into a voltage command to be applied to the brushless motor 4 and outputs the voltage command to the inverter circuit 72. The brushless motor 4 is configured to perform DC excitation and position the rotor when the brushless motor 4 starts rotating. That.

JP-A-11-187690

  However, in the conventional configuration, the DC excitation that is performed when the brushless motor 4 is started to rotate differs depending on the magnitude of the torque applied to the brushless motor 4, so that there is a margin regardless of the torque applied to the brushless motor 4. Therefore, there is a problem that the operation time of the washing machine is always long because direct current excitation is performed for a certain time.

  The present invention solves the above-mentioned conventional problems, does not require any additional cost of parts, minimizes the time of direct current excitation when the brushless motor 4 starts to rotate, and unnecessarily operates the washing machine. An object is to provide a washing machine that does not take a long time.

  In order to solve the above-described conventional problems, the washing machine of the present invention is an inverter-driven brushless that drives a washing tub rotatably provided in an outer tub and a stirring blade rotatably provided in an inner bottom portion of the washing tub. Control, motor, water supply means for supplying washing water into the washing tub, drainage means for draining the washing water in the washing tub, water supply means, brushless motor, drainage means, etc., washing, rinsing, dewatering A control device that sequentially controls the series of strokes, and when the brushless motor is rotationally started by the control device, the brushless motor has a time for direct current excitation, and the time for the direct current excitation is It is variable according to the magnitude of torque applied to the brushless motor.

  This eliminates the need for additional parts costs, minimizes the time required for DC excitation when the brushless motor starts rotating, and does not unnecessarily increase the operating time of the washing machine. Machine can be realized.

  The washing machine of the present invention does not require additional parts costs, and can minimize the time of direct current excitation when the brushless motor starts rotating, and unnecessarily increases the operation time of the washing machine. A washing machine can be realized.

Side sectional view of the washing machine according to Embodiment 1 of the present invention. Block diagram of motor control device of the washing machine The figure which shows the table which prescribed | regulated the relationship between the torque of the said washing machine, and DC excitation time Side sectional view of the washing machine according to Embodiment 2 of the present invention. The figure which shows the change of the amount of water in the washing tub in each process of washing, rinsing and dehydration of the washing machine The figure which shows the table which prescribed | regulated the relationship between the amount of water in the washing tub of the washing machine, and DC excitation time Side sectional view of the washing machine according to Embodiment 3 of the present invention. Operation flowchart for determining DC excitation time according to the amount of cloth in the washing tub of the washing machine The figure which shows the table which prescribed | regulated the relationship between the amount of cloth in the washing tub of the washing machine, and DC excitation time

  According to a first aspect of the present invention, there is provided a washing tub that is rotatably provided in an outer tub, an inverter-driven brushless motor that drives an agitating blade that is rotatably provided at an inner bottom of the washing tub, and washing water in the washing tub. A water supply means for supplying water, a drainage means for draining the wash water in the washing tub, a control device for controlling the water supply means, brushless motor, drainage means, etc., and sequentially controlling a series of steps of washing, rinsing and dehydration A time for performing DC excitation on the brushless motor when the brushless motor is rotationally started by the control device, and the time for performing the DC excitation depends on the magnitude of torque applied to the brushless motor. By making it variable, it is possible to minimize the DC excitation time required when starting the rotation of the brushless motor without the need for additional parts costs. That no washing machine operating time is longer can be achieved.

According to a second aspect of the present invention, in the first aspect of the invention, there is provided water amount detection means for detecting the amount of washing water in the washing tub, and the control device performs a DC excitation time when the brushless motor starts rotating. Is variable according to the amount of washing water in the washing tub detected by the water amount detecting means, so that no additional cost of parts is required and time for DC excitation to be performed when starting the rotation of the brushless motor is required. A washing machine that can be minimized and that does not unnecessarily increase the operation time of the washing machine can be realized.

  According to a third aspect of the present invention, in the first or second aspect of the invention, there is provided cloth amount detection means for detecting the amount of laundry in the washing tub, and the control device performs the rotation start of the brushless motor. By making the DC excitation time variable according to the amount of laundry in the washing tub detected by the cloth amount detection means, no additional cost of parts is required, and direct current is performed when the brushless motor starts rotating. The excitation time can be minimized, and a washing machine that does not unnecessarily increase the operation time of the washing machine can be realized.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments.

(Embodiment 1)
FIG. 1 is a side sectional view of a washing machine according to Embodiment 1 of the present invention, and FIG. 2 is a block diagram of a motor control device of the washing machine. As shown in FIGS. 1 and 2, the washing machine of the present embodiment includes a washing tub 3 that is rotatably provided in the outer tub 1, and a stirring blade 2 that is rotatably provided at the inner bottom of the washing tub 3. A brushless motor 4 for driving the washing tub 3 and the stirring blade 2, a water supply means 6 for supplying washing water into the washing tub 3, a draining means 5 for draining the washing water in the washing tub 3, a water supply means 6, A control device 7 is provided for controlling the brushless motor 4, the drainage means 5, etc., and sequentially controlling a series of steps of washing, rinsing and dehydration.

  The control device 7 applies an AC voltage from the power supply 8 (AC power supply) to the rectifier circuit 71, the rectifier circuit 71 converts the DC voltage into a DC voltage, and applies the DC voltage to the inverter circuit 72.

  The inverter circuit 72 converts the DC power from the rectifier circuit 71 into AC power to drive the brushless motor 4, and is composed of a three-phase full-bridge inverter circuit composed of six power switching semiconductors and antiparallel diodes. Usually, it is composed of an insulated gate bipolar transistor (IGBT), an antiparallel diode, and an intelligent power module (IPM) incorporating a drive circuit and a protection circuit thereof. The power switching semiconductor may be composed of a metal oxide semiconductor field effect transistor (MOSFET) in addition to the IGBT. Since the configuration of the inverter circuit 72 is the same as that well known, detailed description thereof is omitted. The brushless motor 4 is connected to the output terminal of the inverter circuit 72 to drive the stirring blade 2 or the washing tub 3.

  The current detection means 73 detects motor currents Iu, Iv, Iw of the brushless motor 4. In the case of a three-phase motor, a method of obtaining a two-phase current (for example, Iu, Iv) using resistors 73a and 73b and obtaining a remaining one-phase current (Iw) from Kirchhoff's law (Iu + iv + Iw = 0) is common. It is.

  The voltage detection unit 74 detects a voltage input to the inverter circuit 72.

  From the output signal of the current detection means 73, the current conversion means 76 is a current component in the rotor magnetic flux direction (hereinafter referred to as d-axis current Id) and a current component perpendicular to the rotor magnetic flux direction (hereinafter referred to as q-axis current Iq). ) Has a structure for three-phase / two-phase conversion.

The rotor position detection means 77 can detect the rotor angle and speed from the voltage equation of the motor without a device for directly detecting the rotor position. In the motor voltage equation, the rotor angle and speed are calculated using the d-axis current Id, the q-axis current Iq, the voltage detected by the voltage detection means 74, and the applied voltage of the motor. In general, as the rotor speed increases, the higher the number of rotations of the rotor, the higher the voltage, so that the rotor position detection accuracy is improved. On the other hand, the lower the rotor rotational speed, the smaller the voltage, so that the rotor position detection accuracy is deteriorated.

  The speed control means 78 determines the q-axis current command value Iqs of the q-axis current Iq (torque current) which is a DC current component and the magnetic flux direction of the rotor from the rotor speed of the brushless motor 4 of the rotor position detection means 77.

  The current control means 79 compares the q-axis current command value Iqs from the speed control means 78 with the d-axis current Id calculated by the current conversion means 76 and the q-axis current Iq, respectively, so as to control the motor current. A voltage command Vd in the magnetic flux direction and a voltage command Vq perpendicular to the magnetic flux direction of the rotor are calculated. The d-axis current Id and the q-axis current Iq calculated by the current conversion unit 76 are updated each time conversion is performed.

  The voltage conversion means 75 converts the voltage command Vd in the rotor magnetic flux direction and the voltage command Vq perpendicular to the rotor magnetic flux direction into voltage commands Vu, Vv, and Vw to be applied to the brushless motor 4 and outputs them to the inverter circuit 72.

  About the washing machine comprised as mentioned above, the operation | movement at the time of the rotation start of the brushless motor 4 and an effect | action are demonstrated. When the brushless motor 4 is rotationally started, the control device 7 performs DC excitation on the brushless motor 4 to position the rotor. The DC excitation time for the brushless motor 4 necessary for positioning the rotor requires a longer time as the torque applied to the brushless motor 4 is larger. Conversely, the smaller the torque applied to the brushless motor 4, the shorter the DC excitation time required for positioning.

  Therefore, if sufficient DC excitation time necessary for positioning the rotor is ensured regardless of the state of the torque applied to the brushless motor 4, the operation time for washing and drying becomes unnecessarily long.

  Therefore, in the washing machine of the present embodiment, when the brushless motor 4 is rotationally started by the control device 7, the time for performing DC excitation on the brushless motor 4 can be varied according to the magnitude of torque applied to the brushless motor 4. did. Hereinafter, a specific example will be described with reference to the drawings.

  FIG. 3 is a view showing a table that defines the relationship between the torque of the washing machine of this embodiment and the DC excitation time. The control device 7 has a table as shown in FIG. 3 in the storage means (not shown) in advance, and the current of the brushless motor 4, for example, at the initial stage of the start of the driving course washed by the user. The torque applied to the brushless motor 4 is measured using the value, the DC excitation time is determined with reference to the table of FIG. 3 according to the value, and the DC excitation at the start of the rotation of the brushless motor 4 in each subsequent process. Apply as time. For example, if the measured torque is 8 to 11 N · m, the DC excitation time is 5 seconds. The determined DC excitation time is reset at the end of the operation course.

  Further, the torque fluctuates in each step of washing, rinsing, and dehydration, and the DC excitation time may be made more finely corresponding to this. The torque is measured using the current value of the brushless motor 4 at the beginning of each stroke, and the DC excitation time is determined according to the value in accordance with the table shown in FIG. 3, and the DC excitation time when the brushless motor 4 starts rotating. It may be applied as

As described above, according to the washing machine of the present embodiment, when the brushless motor 4 is rotationally started by the control device 7, the time for performing DC excitation on the brushless motor 4 is the magnitude of the torque applied to the brushless motor 4. Therefore, the DC excitation time when starting the rotation of the brushless motor 4 can be shortened to the minimum necessary without the additional cost of parts, and the operation time of the washing machine is reduced. It will not be long as necessary.

(Embodiment 2)
FIG. 4 is a side sectional view of the washing machine according to the second embodiment of the present invention. As shown in FIG. 4, the washing machine of the present embodiment has water amount detection means 9 that detects the amount of washing water in the washing tub 3. Other configurations are the same as those of the first embodiment, and detailed description thereof is omitted.

  The washing machine performs washing by sequentially performing washing, rinsing, part of dehydration, or a plurality of processes. In general, a certain amount of washing water is accumulated in the washing tub 3 in the rinsing process. On the other hand, in the dehydration process, the laundry is dehydrated by rotating the washing tub 3 in a state where there is no washing water in the washing tub 3.

  When the amount of water in the washing tub 3 is large, the torque applied to the brushless motor 4 increases, and the DC excitation time required for positioning the rotor becomes longer. On the contrary, when the amount of water in the washing tub 3 is small, the torque applied to the brushless motor 4 is small, and the DC excitation time necessary for positioning the rotor is shortened.

  In the washing machine of the present embodiment, when the brushless motor 4 is rotationally started by the control device 7, the time for performing DC excitation on the brushless motor 4 is variable according to the amount of washing water in the washing tub 3. Hereinafter, a specific example will be described with reference to the drawings.

  FIG. 5 is a diagram showing a change in the amount of water in the washing tub in each of the washing, rinsing, and dewatering steps of the washing machine of this embodiment, and FIG. It is a figure which shows the table which prescribed | regulated the relationship with time.

  As shown in FIG. 5, the amount of water is generally large (for example, 51 L) in the washing step, and the amount of water is 0 L in the cloth amount determination or the dehydration step, and the difference is a considerable amount. Further, the amount of water is changed finely according to the operation stage in each stroke.

  Therefore, a table as shown in FIG. 6 is stored in advance in the storage means (not shown) of the control device 7, and the water amount in the washing tub 3 is measured by the water amount detecting means 9 at the initial stage of each process start. The DC excitation time is determined with reference to the table of FIG. 6 according to the value, and is applied as the DC excitation time when the brushless motor 4 starts rotating in the stroke.

  For example, as shown in FIG. 5, if the amount of water measured in the first stage of the washing process (washing stirring 1) is 35 L, the amount of water in washing stirring 2 that is the maximum amount of water in the washing process is predicted to be 51 L, and washing is performed. The DC excitation time in the process is 9 seconds. Similarly, in the rinsing process, the DC excitation time is set to 7 seconds for the predicted maximum water volume of 45L, and in the dehydration process, the DC excitation time is set to 3 seconds for the water volume of 0L, and the brushless motor 4 is started to rotate. The determined DC excitation time is reset at the end of the operation course.

  Further, as described above, the amount of water is finely changed in accordance with the operation stage even in the steps of washing, rinsing, and dehydration, and the DC excitation time may be made finer in response to this. At each operation stage in each stroke, the amount of water in the washing tub 3 is measured by the water amount detecting means 9, and the DC excitation time is determined by the table of FIG. 6 according to the value, and the DC excitation at the start of the rotation of the brushless motor 4 Apply as time. For example, in the case of FIG. 5, in the washing tub rotation 1, the DC excitation time is 3 seconds for 0 L of water, the washing stirring 1 is 5 seconds for 35 L, the washing stirring 2 is 9 seconds for 51 L, and the rinsing stirring 1 is 22 L 4 seconds, 3 seconds for 0L in the washing tub rotation 2, and 7 seconds for 45L in the rinse stirring 2 are set and executed.

  As described above, according to the washing machine of the present embodiment, when the brushless motor 4 is rotationally started by the control device 7, the time for performing DC excitation on the brushless motor 4 is set to the amount of washing water in the washing tub 3. Therefore, the DC excitation time when the brushless motor 4 is started to rotate can be reduced to the minimum necessary without any additional parts cost, and the washing machine operation time is reduced. It will not be long as necessary.

(Embodiment 3)
FIG. 7 is a side sectional view of the washing machine according to the third embodiment of the present invention. As shown in FIG. 7, the washing machine according to the present embodiment includes a cloth amount detection unit 10 that detects the amount of laundry in the washing tub 3. Other configurations are the same as those of the first embodiment, and detailed description thereof is omitted.

  The amount of laundry to be washed at one time varies depending on the family structure and lifestyle of the user who uses the washing machine.

  When the amount of laundry in the washing tub 3 is large, the torque applied to the brushless motor 4 increases, and the DC excitation time necessary for positioning the rotor becomes longer. Conversely, when the amount of laundry in the washing tub 3 is small, the torque applied to the brushless motor 4 is small, and the DC excitation time necessary for positioning the rotor is shortened.

  Therefore, in the washing machine of the present embodiment, when the brushless motor 4 is rotationally started by the control device 7, the time for performing DC excitation on the brushless motor 4 can be made variable according to the amount of laundry in the washing tub 3. did. Hereinafter, a specific example will be described with reference to the drawings.

  FIG. 8 is an operation flowchart for determining the DC excitation time according to the amount of cloth in the washing tub of the washing machine of this embodiment. FIG. 9 is the amount of cloth in the washing tub of the washing machine of this embodiment (the amount of laundry). It is a figure which shows the table which prescribed | regulated the relationship between quantity) and DC excitation time.

  In recent washing machines, the amount (weight) of laundry is measured and judged (cloth amount sensing) for the purpose of saving power, saving water, protecting the environment, and shortening the washing time. An increasing number of washing machines have a function of changing washing conditions such as the amount of water to be supplied, the amount of detergent, the time for washing and dehydration, and the number of times of rinsing.

  As shown in FIG. 8, the washing machine according to the present embodiment measures the amount of cloth in the washing tub 3 by the cloth amount detecting means 10 and determines the DC excitation time for the brushless motor 4 according to the result. To perform the operation. The control device 7 has a table as shown in FIG. 9 in the storage means (not shown) in advance, and direct current excitation is performed with reference to the table of FIG. 9 according to the measured cloth amount. The time is determined and applied as the DC excitation time when the brushless motor 4 starts rotating.

  For example, if the amount of cloth (the weight of the laundry) is 3.0 to 5.0 kg, the DC excitation time is 9 seconds. The determined DC excitation time is reset at the end of the operation course.

  In addition, the amount of cloth (more precisely, the weight of the laundry) varies in each process of washing, rinsing, and dehydration, and the DC excitation time may be made finer in response to this. At the initial stage of each stroke, the cloth amount (the weight of the laundry) is measured by the cloth amount detecting means 10, and the DC excitation time is determined by the table shown in FIG. 9 according to the measured value. The DC excitation time may be applied.

Moreover, it is also possible to use it together with the method of determining the DC excitation time according to the amount of water in the washing tub 3 measured by the water amount detecting means 9 described in the second embodiment.

  Furthermore, in a washing machine having a function of automatically or manually selecting the amount of water supplied to the washing tub 3 from a plurality of water amounts prepared in advance according to the measured amount of cloth (the weight of the laundry), the amount of cloth is detected. The amount of cloth in the washing tub 3 is measured by the means 10, and based on the amount of water selected according to the result, a brushless table is used to define the relationship between the amount of water in the washing tub and the DC excitation time as shown in FIG. The DC excitation time for the motor 4 may be determined and the rotor positioning may be executed.

  As described above, according to the washing machine of the present embodiment, when the brushless motor 4 is rotationally started by the control device 7, the time during which DC excitation is performed on the brushless motor 4 is the amount of laundry in the washing tub 3. It is possible to reduce the DC excitation time when rotating the brushless motor 4 to the minimum necessary without making additional costs for parts by making it variable according to the need for operation time of the washing machine. It will never be long.

  In each of the above embodiments, a so-called pulsator-type washing machine having a stirring blade in the washing tub is used, but for a rotating drum type washing machine that does not have a stirring wing and rotates the washing tub at a low speed even during washing. The present invention is also applicable. Moreover, the washing-drying machine provided with the drying function may be sufficient.

  As described above, the washing machine according to the present invention does not require the additional cost of parts, and can reduce the time of direct current excitation when rotating the brushless motor to the minimum necessary. It is useful as a washing machine that drives a brushless motor, and a washing / drying machine.

DESCRIPTION OF SYMBOLS 1 Outer tub 2 Agitation blade 3 Washing tub 4 Brushless motor 5 Drainage means 6 Water supply means 7 Control device 8 Power supply 9 Water amount detection means 10 Cloth amount detection means 71 Rectifier circuit 72 Inverter circuit 73 Current detection means 74 Voltage detection means 75 Voltage conversion means 76 Current conversion means 77 Rotor position detection means 78 Speed control means 79 Current control means

Claims (3)

An inverter-driven brushless motor that drives a washing tub rotatably provided in the outer tub and an agitating blade provided rotatably at the inner bottom of the washing tub, and water supply means for supplying washing water into the washing tub, A drainage means for draining the washing water in the washing tub; and a control device for controlling the water supply means, brushless motor, drainage means, etc., and sequentially controlling a series of steps of washing, rinsing and dewatering, and the control device. When the brushless motor is started to rotate, the brushless motor has a time for performing DC excitation, and the time for performing the DC excitation is variable according to the magnitude of torque applied to the brushless motor. Washing machine. Water amount detecting means for detecting the amount of washing water in the washing tub is provided, and the control device detects the time of DC excitation performed when the brushless motor is rotated and started by the water amount detecting means. 2. The washing machine according to claim 1, wherein the washing machine is variable according to the amount of washing water. The laundry tub has a cloth amount detecting means for detecting the amount of laundry in the washing tub, and the control device detects the time of DC excitation performed when the brushless motor is rotated and started by the cloth amount detecting means. The washing machine according to claim 1 or 2, wherein the washing machine is variable according to the amount of laundry in the washing machine.

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