JP7204445B2 - Washing machine - Google Patents

Description

The technology disclosed relates to a washing machine in which a heater heats the water.

For example, Japanese Laid-Open Patent Application Publication No. 2002-100001 has proposed a number of washing machines in which washing water is heated by a heater in order to enhance the washing effect.

JP 2014-200422 A

Washing water used in the washing process or rinsing water used in the rinsing process is more effective when the temperature is high. Although the amount of water has decreased in recent years due to improvements in water-saving technology, at least the amount of water that sufficiently wets the laundry is necessary. Therefore, it is necessary to generate a large amount of heat with the heater in order to warm the wash water or the like to an appropriate temperature.

Furthermore, in the case of a washing machine, the heating time is limited from the viewpoint of convenience. Therefore, a large current is normally supplied to the heater during the hot water heating process. In particular, when the water temperature is low, such as in winter, a larger amount of heat is required, so a larger current must be supplied to the heater.

On the other hand, in the washing process and the rinsing process, it is necessary to rotate the drum by driving the motor. In particular, when starting, a large torque is required because the inertial force does not act. Therefore, when the heating by the heater and the driving of the motor overlap, an excessive current flows through the washing machine, which may cause the breaker to malfunction and stop the operation of the washing machine.

A main object of the technology disclosed is to suppress the inflow of overcurrent due to the combined use of heater heating and motor driving, and to realize stable operation of the washing machine.

The technology disclosed relates to a washing machine.

The washing machine includes a tub capable of storing water, a drum disposed inside the tub for storing laundry, a motor rotating the drum, a heater heating water stored inside the tub, and the motor. and a controller that controls the heater.

A water heating process in which the controller starts supplying electric power to the heater from a timing before driving the motor, and an electric power to the heater at a timing to start driving the motor during execution of the water heating process. and a hot water supply interruption process for temporarily restricting the supply.

That is, according to this washing machine, a heater is provided to heat the water accumulated inside the tub, and a water heating process is performed in which power supply to the heater is started before the motor is driven. As a result, the washing water and the rinsing water are warmed prior to the washing process and the rinsing process, so that the washing can be performed effectively while shortening the operation time.

Then, when the motor starts to be driven during the hot water heating process, the motor is required to generate a large torque at the time of start-up. As a result, the breaker may malfunction and stop the operation of the washing machine.

On the other hand, in this washing machine, the hot water supply interrupting process is executed to temporarily limit the electric power supply to the heater at the timing when the motor starts to be driven. Therefore, a rapid increase in the current value at startup is suppressed, and stable operation of the washing machine can be realized.

The washing machine also includes a current input path branched from the power supply side to supply a primary current to each of the heater and the motor, and the value of the primary current is set in advance during execution of the water heating interruption process. The controller may release restriction on the power supply to the heater when the power falls below a set predetermined value.

For example, a primary current sensor may be installed in the current input path, and the primary current sensor may be used to detect the value of the primary current.

Further, when an inverter is interposed between the current input path and the motor and supplies a drive current to the motor, the primary current is detected using a current sensor and a voltage sensor attached to the inverter. may be estimated.

In the washing machine, the controller may cancel restriction on power supply to the heater when the torque of the motor starts to decrease during the execution of the water heating interruption process.

In that case, it may be determined that the torque of the motor has started to decrease when the drive current that generates the torque in the motor is lower than a predetermined value.

The washing machine also detects the number of rotations of the motor using a rotation sensor attached to the motor, and detects when the number of rotations of the motor reaches a predetermined number of rotations during the execution of the water heating interruption process. , the controller may unrestrict power supply to the heater.

In the washing machine, the water heating interrupting process may be performed by controlling the power supply to the heater so that the value of the primary current falls within a predetermined range.

According to the disclosed technology, since the inflow of overcurrent can be suppressed, stable operation of the washing machine can be realized.

It is an example of a washing machine to which the disclosed technology is applied. It is an electric circuit diagram regarding an inverter and a heater. 1 is a block diagram showing a controller and its main associated devices; FIG. It is a flow chart which shows an example of operation of a washing machine. It is a flow chart which shows an example of a washing process. It is a figure which shows the specific example of a hot-water-heating interruption process. The upper stage is a time chart of ON/OFF control of the heater, the middle stage is a time chart of the command value of the rotation speed of the motor, and the lower stage is the temporal change of the primary current corresponding thereto. 2 equivalent view of the washing machine of the modified example 1. FIG. It is a figure explaining the washing machine of the modification 2. FIG.

Embodiments of the disclosed technology will be described in detail below with reference to the drawings. However, the following description is essentially merely an example, and does not limit the present invention, its applications, or its uses.

<Washing machine structure>
FIG. 1 shows an example of a drum-type washing machine (hereinafter also simply referred to as washing machine 1) to which the technology disclosed is applied. The washing machine 1 mainly includes a housing 2, a tub 3, a drum 4, a motor 5, an inverter 6, a controller 7 and the like.

In this washing machine 1, a drum 4 containing laundry rotates around a horizontal axis J (an axis extending in a substantially horizontal direction or an inclined direction). The washing machine 1 is a so-called fully automatic washing machine, and is configured to automatically perform a series of washing processes including washing, rinsing, dehydration, and the like.

(Case)
The housing 2 is a box-shaped container made up of panels and frames, and constitutes an outer shell of the washing machine 1 . A circular loading slot 2a is formed on the front surface of the housing 2 for loading and unloading laundry. A door 2b having a transparent window is attached to the inlet 2a. The inlet 2a is opened and closed by a door 2b.

Above the inlet 2a of the housing 2, an operation unit 8 having switches and the like operated by the user is installed. A controller 7 and a power supply unit 9 connected to an external commercial power supply are installed on the upper rear side of the housing 2 . The power supply unit 9 supplies electric power corresponding to each electric device to each electric device inside the housing 2 such as the controller 7 and the inverter 6 .

(Tab 3)
Inside the housing 2, a tab 3 is installed that communicates with the inlet 2a. The tub 3 is a bottomed cylindrical container capable of storing water, and its opening is connected to the inlet 2a. The tab 3 is supported by a damper (not shown) provided inside the housing 2 so as to be stable in a posture in which the horizontal axis J passing through the center thereof is slightly inclined upward toward the front. .

A water supply device 10 including a water supply pipe 10a, a water supply valve 10b, a medicine injection device 10c, and the like is provided on the upper portion of the tub 3. As shown in FIG. An upstream end of the water supply pipe 10a protrudes outside the washing machine 1 and is connected to a water supply source (not shown). A downstream end of the water supply pipe 10 a is connected to a water supply port 3 a opening at the top of the tub 3 . The water supply valve 10b and the medicine injection device 10c are installed in the middle of the water supply pipe 10a in this order from the upstream side.

The medicine injection device 10c contains a medicine such as detergent and softener, and has a case that can be put in and taken out from the housing 2. As shown in FIG. Before washing, a medicine is put into the medicine injection device 10c. Thereby, the medicine injection device 10c injects the stored medicine into the tub 3 by mixing it with the water to be supplied.

A tray-shaped water reservoir 30 recessed downward is provided at the bottom of the tub 3 . A water level sensor 11 , a water temperature sensor 12 and a heater 31 are installed in the water reservoir 30 .

The water level sensor 11 detects the level of water accumulated in the tub 3 and outputs the detected water level to the controller 7 . A water temperature sensor 12 detects the temperature of water stored in the tub 3 and outputs the detected water temperature to the controller 7 . The heater 31 is composed of a sheathed heater or the like, and generates heat by being supplied with power from the power supply unit 9 to heat the water stored inside the tub 3 . The heater 31 is controlled by the controller 7, the details of which will be described later.

A drainage pump 20 is installed below the tub 3 . A water flow port is opened in the bottom surface of the water storage part 30 . The water passage is connected to the drainage pump 20 via the water passage pipe 34 . Water accumulated in the tub 3 is introduced into the drainage pump 20 through the water conduit 34 .

The drain pump 20 has a drain pipe 20a, and its drive is controlled by the controller 7. As shown in FIG. When the drainage pump 20 is driven, water accumulated in the tub 3 is discharged from the washing machine 1. - 特許庁

(drum 4)
The drum 4 consists of a cylindrical container slightly smaller in diameter than the tub 3 and is arranged inside the tub 3 with its center aligned with the tub 3 and its bottom facing rearward. A circular opening 41 facing the inlet 2a is formed in the front portion of the drum 4. As shown in FIG. The laundry is put into the drum 4 through the inlet 2 a and the opening 41 . A front portion of the drum 4 is rotatably supported by the inlet 2a.

A large number of dewatering holes 42 penetrating inside and outside are formed in the peripheral wall of the drum 4 over substantially the entire surface thereof. A plurality of lifters 43 are provided on the inner surface of the peripheral wall of the drum 4 .

(motor 5)
A motor 5 is installed at the rear of the tub 3 . A shaft 5 a of the motor 5 passes through the rear portion of the tab 3 and protrudes inside the tab 3 . The tip of the shaft 5a is fixed to the center of the rear portion of the drum 4. As shown in FIG.

That is, the rear portion of the drum 4 is supported by a shaft 5a, and the motor 5 directly drives the drum 4 under the control of the inverter 6 (so-called direct drive system). As a result, the drum 4 is rotated around the horizontal axis J by being driven by the motor 5 .

The inverter 6 is attached at a position adjacent to the motor 5 . Inverter 6 is controlled by controller 7 . The inverter 6 receives power from the power supply unit 9 and supplies a predetermined drive current to the motor 5 . That is, the inverter 6 forms alternating current (driving current) of three phases with different phases by performing PWM control or the like by switching a direct current of a predetermined voltage converted by an electric circuit 90 to be described later. By supplying these drive currents to the motor 5, the motor 5 rotates.

FIG. 2 shows an electric circuit diagram 90 relating to the inverter 6 and the heater 31, which consume a particularly large amount of power. The main body of the illustrated electric circuit 90 is provided in the power supply section 9 . The electric circuit 90 includes a pair of current input paths 91L and 91N, a rectifying section 92, a smoothing section 93, a pair of current output paths 94H and 94L, a branch path 95, and the like.

Inverter 6 is connected to motor 5 via wiring for outputting each of the three-phase alternating currents. A rotation sensor 13 such as a Hall sensor is attached to the motor 5 .

The current input paths 91L and 91N consist of a first current input path 91L connected to the live side of the commercial power supply and a second current input path 91N connected to the neutral side of the commercial power supply. The current output paths 94H and 94L are composed of a high voltage side path 94H connected to the high voltage side of the inverter 6 and a low voltage side path 94L connected to the low voltage side of the inverter 6. FIG.

The low voltage side path 94L is connected to a reference potential (so-called ground). A current sensor 14 (attached to the inverter 6) is installed in the low voltage side path 94L. A voltage sensor 15 (attached to the inverter 6) is installed in the high voltage side path 94H.

The smoothing section 93 has two capacitors 93a, 93a connected in series, and is provided between the high voltage side path 94H and the low voltage side path 94L. The rectifying section 92 has a diode and is connected to the first current input path 91L, the second current input path 91N, the high voltage side path 94H, and the low voltage side path 94L. The second current input path 91N is further connected to a portion of the smoothing section 93 between the two capacitors 93a, 93a.

The branch path 95 branches off from the first current input path 91L. The branch path 95 is connected to the heater 31 via a relay 96 capable of on/off control. The heater 31 is also connected to a reference potential (so-called earth). Therefore, the current (primary current) input from the commercial power supply through the first current input path 91L is distributed to both the motor 5 and the heater 31. FIG.

(Controller 7)
Controller 7 comprehensively controls the operation of washing machine 1 . The controller 7 is composed of hardware such as a CPU and memory, and software such as control programs and various data.

FIG. 3 shows the controller 7 and its main associated devices. A water level sensor 11, a water temperature sensor 12, a current sensor 14, a voltage sensor 15, a rotation sensor 13, an operation unit 8, an inverter 6, a water supply valve 10b, a heater 31, a drainage pump 20, and the like are electrically connected to the controller 7. there is

The current sensor 14 detects the current value input to the inverter 6 and outputs it to the controller 7 . The voltage sensor 15 detects the voltage value input to the inverter 6 and outputs it to the controller 7 . A rotation sensor 13 detects the rotation speed of the motor 5 and outputs it to the controller 7 .

The operation unit 8 outputs to the controller 7 instruction information such as operation start and operation mode selection input by the user. The controller 7 controls the inverter 6, the water supply valve 10b, the heater 31, the drainage pump 20, etc. based on these measured values and instruction information.

The controller 7 has a washing processing unit 71, a rotation control unit 72, and a warm water heating processing unit 73 as functional configurations. The laundry processing unit 71 executes a series of laundry processing including steps such as washing, rinsing, dehydration, etc. according to instructions. The rotation control unit 72 controls the rotation of the motor 5 (drum 4) by controlling the inverter 6 accompanying the washing process. The warm water heating unit 73 controls the heater 31 to warm the washing water and the rinse water (warm water heating process) in association with the washing process.

<Operation of washing machine 1>
FIG. 4 shows an example of operation of the washing machine 1. As shown in FIG.

When the laundry process is performed, first, the user puts the laundry into the drum 4 (step S1). In the case of this washing machine 1, at that time, the detergent or the like is also put into the chemical injection device 10c. Then, an instruction to start washing is input to the controller 7 by operating the operation unit 8 (Yes in step S2). As a result, the controller 7 (washing processing unit 71) automatically starts a series of operations including washing, rinsing, dehydration, and the like according to the instruction.

Prior to the washing process, the controller 7 rotates the drum 4 loaded with laundry to measure the amount of laundry in order to set the amount of water supply (step S3). Since the method for measuring the amount of laundry is known, the description thereof is omitted here.

After measuring the amount of laundry, the controller 7 starts the washing process (step S4). FIG. 5 illustrates the flow of processing in the washing process.

When the washing process starts, the controller 7 controls the water supply valve 10b to supply a predetermined amount of water according to the amount of laundry to the tub 3 (step S10). At that time, the detergent contained in the chemical injection device 10c is injected into the tub 3 together with the supplied water. As a result, a predetermined amount of wash water (mixed water of water and detergent) accumulates in the lower portion of the tub 3, and the water reservoir 30 is filled with water.

When the controller 7 (warm water processing unit 73) determines that the water storage unit 30 is filled with water based on the detection value input from the water level sensor 11, it executes the warm water processing. That is, the controller 7 is preset with predetermined determination water temperatures Ts1 and Ts2 (Ts1<Ts2, for example, around 60° C.) at which the cleaning effect increases.

Based on the detected value input from the water temperature sensor 12, the controller 7 turns on the heater 31 to dispense the washing water if the temperature of the water stored in the tub 3 is equal to or lower than the predetermined judgment water temperature Ts1 (Yes in step S11). Heat (step S12).

Specifically, as shown in FIG. 2, the controller 7 switches the relay 96 to turn on the heater 31 . As a result, the primary current from the commercial power source flows into the heater 31 through the first current input path 91L and the branch path 95, and the heater 31 generates heat. The heat generated by the heater 31 gradually increases the temperature of the water stored in the tub 3 .

The controller 7 determines whether the temperature of the water stored in the tub 3 has reached the determination water temperature Ts2 (step S13). As a result, when it is determined that the water temperature is equal to or higher than the determination water temperature Ts2, the controller 7 switches the relay 96 to turn off the heater 31 (step S14).

Until the washing process ends (No in step S15), if the temperature of the water stored in the tub 3 becomes equal to or lower than the judgment water temperature Ts1, the warm water heating process is performed again. The controller 7 repeats such processing until the washing process is completed.

When the amount of water is large, it takes time to reach the judgment water temperature Ts2. When the temperature of the washing water is low, such as in winter, it takes even longer. In some cases, the temperature may not reach the judgment water temperature Ts2.

Therefore, the heater 31 is configured to be supplied with a large value of primary current so as to increase the amount of heat generated. Since power is directly supplied to the heater 31 from the commercial power source, the amount of power supplied to the heater 31 per unit time is constant.

On the other hand, the controller 7 determines, for example, whether or not a predetermined time t0 has elapsed since the water supply was completed (step S16). As a result, when the predetermined time t0 has passed, the controller 7 (rotation control unit 72) drives the motor 5 and starts rotating the drum 4 without waiting for the temperature to rise to the judgment water temperature Ts2 (step S17). .

Specifically, as shown in FIG. 2 , the controller 7 controls the inverter 6 to start supplying power to the motor 5 . As a result, the primary current from the commercial power supply flows into the electric circuit 90 through the first current input path 91L and the second current input path 91N, and the power converted to direct current is input to the inverter 6. The electric power is converted into a predetermined drive current and output to the motor 5 . The motor 5 rotates at a direction and speed according to the drive current.

When the motor 5 starts to rotate, that is, when it starts, a large torque is required because inertial force does not act. That is, the drum 4 contains the laundry and the washing water is also stored. Since the drum 4 rotates while picking up wet laundry and accumulated water, a large torque is required to rotate the drum 4 from a stopped state.

On the other hand, the motor 5 is controlled to rotate at a predetermined number of revolutions. Therefore, when the motor 5 is started, a large primary current flows into the inverter 6 . At this time, if the water heating process is being executed, the output to the heater 31 side overlaps, so the value of the primary current flowing into the electric circuit 90 increases at once. As a result, in some cases, the breaker may malfunction and the washing machine 1 may stop operating.

Therefore, the washing machine 1 is devised to suppress malfunction of the breaker so that stable operation can be performed.

That is, when the motor 5 is started during execution of the water heating process (Yes in step S18), the controller 7 temporarily restricts the power supply to the heater 31 at the start timing (heating interruption process). ).

Specifically, the controller 7 is preset with an upper limit value Is of the primary current that can be input. The controller 7 obtains the value (total value) of the primary current flowing into the electric circuit 90 from the value of the primary current flowing into the motor 5 .

In this embodiment, the value of the primary current flowing into the electric circuit 90 is obtained by estimating it using the current sensor 14 and voltage sensor 15 attached to the inverter 6 . Specifically, the primary current flowing from the first current input path 91L flows through both the smoothing section 93 and the high voltage side path 94H.

The current value flowing into the high voltage side path 94</b>H is the current (motor current) supplied to the motor 5 via the inverter 6 and can be detected by the current sensor 14 . The current (capacitor current) flowing into the smoothing section 93 can be obtained by differentiating the detected value of the voltage sensor 15 .

The primary current can be estimated by multiplying each of the capacitor current and the motor current by a predetermined constant and adding them. If the value of the primary current is obtained in this way, it can be done only by changing the program, so there is no need to add new parts, and the cost can be reduced.

The obtained primary current value is compared with the upper limit value Is, and when the primary current value reaches the upper limit value Is (Yes in step S19), the controller 7 switches the relay 96 to turn off the heater 31 (step S20).

By doing so, the power supply to the heater 31 is stopped, so an increase in the primary current is suppressed. As a result, malfunction of the breaker is prevented, and stable operation can be performed.

Then, the controller 7 compares the value of the primary current with the upper limit Is, and when the value of the primary current becomes equal to or less than the upper limit Is (Yes in step S21), the controller 7 switches the relay 96 to turn on the heater 31. and release the restriction on the power supply to the heater 31 (step S22).

A large torque is required only for a short period of time (several seconds) at the start of rotation from a stopped state. Therefore, after that, even if power is supplied to both the heater 31 and the motor 5, stable operation can be performed.

The controller 7 controls the inverter 6 to rotate the motor 5 (drum 4) at a constant number of revolutions. Then, when the predetermined time t1 has passed (Yes in step S23), the controller 7 stops the motor 5 and reverses the rotation of the drum 4 (step S24).

A large torque is also required when starting the motor 5 again after the motor 5 has stopped. Therefore, if the water heating process is being performed, the controller 7 performs the water heating interruption process in the same manner as before (No in step S15). Since such a reversing process is repeatedly performed during the washing process, if the water heating process is being performed each time, the water heating interruption process is performed.

When the washing process is completed (Yes in step S15), the process returns to the main routine of FIG. 4 and shifts to the rinsing process.

Next, the controller 7 performs a rinsing process (step S5). In the rinsing process, first, the controller 7 drives the drain pump 20 to drain wash water accumulated in the tub 3 .

Next, the controller 7 performs water supply and agitation in the same manner as in the washing process. At that time, it is preferable to perform a warm water treatment, but it is not always necessary. When the warm water heating process is to be performed, the warm water heating interruption process is executed in the same manner as in the washing process. The rinsing process may be performed multiple times. The contents of the rinsing process can be appropriately set according to the specifications.

After the rinsing process is completed, the controller 7 executes the dewatering process (step S6). In the dewatering process, the drum 4 is rotated at high speed for a predetermined time. The laundry sticks to the inner surface of the drum 4 by centrifugal force. Water contained in the laundry flows out of the drum 4 through the dewatering holes 42 . The laundry is thereby dehydrated.

Water accumulated in the tub 3 due to dehydration is drained by the controller 7 driving the drain pump 20 . When the dehydration process is finished, the completion of washing is notified by sounding a predetermined buzzer, etc., and the operation of the washing machine 1 is finished.

(Specific example of water heating interruption processing)
FIG. 6 shows a specific example of the water heating interruption process. In FIG. 6, the upper stage is a time chart of ON/OFF control of the heater 31, the middle stage is a time chart of the command value of the rotation speed of the motor 5, and the lower stage is the temporal change of the primary current corresponding to these.

At the timing ta, the heater 31 is turned on and the water heating process is in progress. Then, at timing tb, a command value instructing rotation at the rotation speed Rs is output from the controller 7 to the inverter 6, and the motor 5 starts to be driven.

When the motor 5 starts to drive, the value of the primary current increases at once and reaches the upper limit value Is (timing tc). If the heater 31 remains ON (upper phantom line), the value of the primary current greatly exceeds the upper limit value Is (lower phantom line), and the operation of the washing machine 1 may stop. On the other hand, in this washing machine 1, the heater 31 is turned off at the same time as the upper limit value Is is reached. This suppresses an increase in primary current.

Then, when the torque required for the motor 5 decreases and the value of the primary current falls below the upper limit value Is (timing td), the restriction on the power supply to the heater 31 is lifted and the heater 31 is turned on again. to The period during which the heater 31 is turned off is short (several seconds). Since the torque of the rotating motor 5 is sufficiently smaller than the torque required at startup, there is no possibility that the value of the primary current will greatly exceed the upper limit value Is even if power is supplied to the heater 31 thereafter.

Therefore, according to this washing machine 1, it is possible to stably prevent an abnormal stop that may occur when the motor 5 is started. Since it is only necessary to prevent the primary current from exceeding the upper limit only for a moment at start-up, the total torque of the motor 5 at start-up can be increased as a result.

Further, originally, as indicated by the virtual line frame in FIG. 2, the first current input path 91L is generally provided with a reactor for suppressing the peak of the primary current. On the other hand, with this washing machine 1, the value of the primary current can be suppressed from exceeding the upper limit value Is, so the reactor can be omitted. Therefore, member costs can be reduced.

(Modification 1)
FIG. 7 shows a modification of the washing machine 1. As shown in FIG. FIG. 7 is a diagram corresponding to FIG. 2 and shows an electric circuit 90 of this modification. The electrical circuit 90 differs from the washing machine 1 of the above-described embodiment in that a primary current sensor 16 that detects the value of the primary current is installed in the first current input path 91L.

Since other configurations are the same as those of the washing machine 1 of the above-described embodiment, the same reference numerals are used for the same configurations, and the description thereof will be omitted. In this modification, the primary current value is directly detected by the primary current sensor 16 and output to the controller 7 . Therefore, the value of the primary current can be detected with high accuracy, so that even more stable operation is possible.

(Modification 2)
The water heating interruption process may be performed by controlling the power supply to the heater 31 so that the value of the primary current falls within a predetermined range.

That is, as shown in the upper part (a) of FIG. 8, in the washing machine 1 of the above-described embodiment, the heater 31 is turned off for a predetermined period, but in this washing machine 1, as shown in the lower part (b) of FIG. , the controller 7 intermittently switches the relay 96 to intermittently turn ON or OFF the heater 31 so that the value of the primary current falls within a range not exceeding the upper limit value Is. According to this, since the OFF time of the heater 31 can be shortened, heating of the water can be promoted.

Note that the washing machine according to the technology disclosed is not limited to the above-described embodiments, and includes various other configurations.

For example, the restriction on power supply to the heater 31 may be released when the torque of the motor 5 starts to decrease. Since the value of the primary current rises sharply when the torque of the motor 5 increases greatly, when the torque of the motor 5 starts to decrease, the power supplied to the motor 5 also decreases, and the value of the primary current also decreases. . Therefore, it is also possible to release the restriction on the power supply to the heater 31 at this timing.

Specifically, when the drive current (so-called q-axis current) that causes the motor 5 to generate torque drops below a predetermined value, it can be determined that the torque of the motor 5 has started to decrease. The drive current value can be obtained based on the detected value of the current sensor 14 .

The restriction on the power supply to the heater 31 may also be released when the number of revolutions of the motor 5 reaches a predetermined number of revolutions. By using the rotation sensor 13, the rotation speed of the motor 5 can be detected. As the motor 5 rotates, the required torque decreases. Therefore, when the number of rotations of the motor 5 reaches a predetermined number of rotations, the value of the primary current also drops below a predetermined value. Therefore, if an appropriate timing is selected, it is also possible to use the number of rotations of the motor 5 to release the restriction on the power supply to the heater 31 .

The technology disclosed is applicable not only to drum-type washing machines but also to vertical washing machines.

1 washing machine 3 tub 4 drum 5 motor 6 inverter 7 controller 31 heater 71 washing processing unit 72 rotation control unit 73 warm water processing unit 90 electric circuit 91L first current input path 91N second current input path 95 branch path 96 relay

Claims (7)

a washing machine,
a water-storable tub;
a drum disposed inside the tub for containing laundry;
a motor for rotating the drum;
a heater for heating water stored inside the tub;
a controller that controls the motor and the heater;
with
the controller
A water heating process for starting power supply to the heater from a timing before driving the motor;
a water heating interrupting process for temporarily restricting the power supply to the heater at the timing of starting the driving of the motor during the water heating process;
and run
further comprising a current input path branching from the power supply side and supplying a primary current to each of the heater and the motor;
The washing machine according to claim 1, wherein the controller cancels restriction on power supply to the heater when the value of the primary current becomes equal to or less than a predetermined value set in advance during execution of the water heating interruption process . In the washing machine according to claim 1,
A primary current sensor is installed in the current input path,
A washing machine, wherein the primary current sensor is used to detect the value of the primary current. In the washing machine according to claim 1,
an inverter interposed between the current input path and the motor and supplying a drive current to the motor;
A washing machine that estimates the value of the primary current using a current sensor and a voltage sensor attached to the inverter. In the washing machine according to claim 1,
The washing machine, wherein the controller cancels restriction on power supply to the heater when torque of the motor starts to decrease during execution of the water heating interruption process. In the washing machine according to claim 4,
A washing machine that determines that the torque of the motor has started to decrease when a drive current that generates torque in the motor is lower than a predetermined value. In the washing machine according to claim 1,
detecting the rotation speed of the motor using a rotation sensor attached to the motor;
The washing machine according to claim 1, wherein the controller cancels restriction on power supply to the heater when the number of revolutions of the motor reaches a predetermined number of revolutions during execution of the water heating interruption process. In the washing machine according to claim 2 or claim 3,
The washing machine according to claim 1, wherein the water heating interrupting process is performed by on/off controlling power supply to the heater so that the value of the primary current falls within a predetermined range.

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