CN108625109B

CN108625109B - Washing machine

Info

Publication number: CN108625109B
Application number: CN201711381042.4A
Authority: CN
Inventors: 世渡智和
Original assignee: Toshiba Lifestyle Products and Services Corp
Current assignee: Toshiba Lifestyle Products and Services Corp
Priority date: 2017-03-24
Filing date: 2017-12-20
Publication date: 2020-11-06
Anticipated expiration: 2037-12-20
Also published as: CN108625109A; JP2018161190A

Abstract

The invention effectively protects the winding of the motor and the switching element of the driving circuit under the abnormal temperature. The washing machine of the embodiment includes: a motor; an inverter circuit including a switching element for driving the motor; a control device for controlling the motor to execute washing operation including a washing stroke; an element temperature detection device that detects a temperature of the switching element; and a motor temperature determination device that determines a temperature of the motor, the control device controlling the motor based on the element temperature detected by the element temperature detection device and the motor temperature determined by the motor temperature determination device.

Description

Washing machine

Technical Field

The present invention relates to a washing machine.

Background

As for the washing machine, there are currently provided: a washing machine using a three-phase brushless DC motor as a drive source and driving the motor by an inverter circuit. In such a washing machine, a winding of a motor and a switching element of an inverter circuit are included as portions which cause a problem of temperature rise during operation. Therefore, the following proposals have been made: in a motor control device, the temperature of a winding of a motor and an inverter circuit is detected, and when the detected temperature exceeds a threshold value, the current flowing through the inverter circuit is limited, thereby suppressing the temperature rise of the winding of the motor and the inverter circuit (for example, see patent document 1).

Patent document

Patent document 1: japanese patent laid-open publication No. 2010-172124

Disclosure of Invention

The winding of the motor of the washing machine and the switching elements of the inverter circuit have different characteristics of temperature change. For example, the windings of the motor have characteristics of being easily heated and easily cooled, and the switching elements have characteristics of being not easily heated and not easily cooled. In addition, although the washing machine performs the washing, rinsing, and dehydration processes, there is a characteristic case in which the temperature of the motor is likely to rise in the washing process compared to other processes. Therefore, it is desirable to effectively protect both the windings of the motor and the switching elements of the inverter circuit in the washing machine.

Accordingly, a washing machine capable of effectively protecting the winding of the motor and the switching element of the inverter circuit in the event of a temperature abnormality is provided.

The washing machine of the embodiment includes: a motor; an inverter circuit including a switching element for driving the motor; a control device for controlling the motor to execute washing operation including a washing stroke; an element temperature detection device that detects a temperature of the switching element; and a motor temperature determination device that determines a temperature of the motor, the control device controlling the washing operation based on the element temperature detected by the element temperature detection device and the motor temperature determined by the motor temperature determination device.

According to the above configuration, since the control device controls the washing operation using both the motor temperature of the motor and the element temperature of the inverter circuit, it is possible to prevent an abnormal temperature rise and to operate the inverter circuit and the motor with maximum performance until the respective temperatures approach the limit values. As a result, the winding of the motor and the switching element of the inverter circuit can be effectively protected against temperature abnormality.

Drawings

Fig. 1 is a longitudinal sectional side view schematically showing the structure of a washing machine according to an embodiment.

Fig. 2 is a rear view of the washing machine shown with the cover removed.

Fig. 3 is a diagram schematically showing an electrical configuration of a control system of a washing machine.

Fig. 4 is a longitudinal sectional side view showing a configuration of a main part of the electronic unit.

Fig. 5 is a diagram showing a temperature change in the washing operation performed 3 times in succession.

Fig. 6 is a diagram showing a temperature rise when the initial temperature in the washing stroke is low.

Fig. 7 is a diagram showing a temperature rise when the initial temperature in the washing stroke is high.

Fig. 8 is a flowchart schematically showing a processing procedure executed by the control device in the inspection mode.

Description of the symbols:

1 … washing machine, 2 … outer box, 6 … water bucket, 11 … rotary bucket, 13 … stirring body, 17 … driving mechanism part, 18 … motor, 21 … clutch mechanism, 30 … electronic unit, 33 … inverter circuit, 34 … control device (motor temperature determination device), 35 a-35 f … IGBT (switching element), 42 a-42 f … element temperature detection device, 52 … power module, 54 … cooling fin, 55 … cooling fan and 56 … storage part.

Detailed Description

Hereinafter, an embodiment applied to a so-called vertical axis type washing machine (full automatic washing machine) will be described with reference to the drawings. First, the overall configuration of the washing machine 1 according to the present embodiment will be described with reference to fig. 1 and 2. The washing machine 1 includes an outer casing 2 formed of, for example, a steel plate and having a rectangular shape as a whole. A bottom plate 4 having 4 legs 3 is provided on the bottom of the outer box 2. The rear plate of the outer box 2 is formed in a rectangular frame shape, and an opening 2a for inspection is formed inside the rear plate. The opening 2a is detachably closed by a cover 5 (see fig. 1).

The detail of fig. 2 also shows that inside the outer box 2, a water tub 6 for storing washing water is provided: is elastically suspended and supported by an elastic suspension mechanism 7 (refer to fig. 1) of a well-known structure. As shown in fig. 1, a drain port 8 is formed in the bottom of the water tub 6, and a drain passage 10 having an electronically controlled drain valve 9 is connected to the drain port 8. Although not shown in detail, an air trap (air trap) is provided at the bottom of the water tub 6, and an air pipe connected to the air trap is provided with: a water level sensor (not shown) for detecting the water level in the water tub 6 (the rotary tub 11).

Inside the water tub 6 are rotatably provided: the rotary tub 11 is a vertical shaft type rotary tub having a substantially bottomed cylindrical shape and serving as both a washing tub and a spin-drying tub. A liquid-filled rotary balancer 12, for example, is attached to an upper end of the rotary tub 11. In addition, a dewatering hole 11a is formed in the peripheral wall of the rotary tub 11. An agitator (pulsator) 13 is disposed at the inner bottom of the rotary tub 11. Laundry, not shown, is stored in the rotary tub 11, and the laundry is washed, rinsed, dehydrated, and dried.

A water barrel cover 14 is installed on the upper portion of the water barrel 6. The water bucket cover 14 is composed of: an opening 14a for taking in and out laundry is provided at a substantially central portion thereof, and an inner lid 15 for opening and closing the opening 14a is attached thereto. A water supply port 16 for supplying water is provided at the rear of the upper surface of the tub cover 14. As shown in fig. 1, a drive mechanism 17 is disposed at a lower portion (outer bottom portion) of the water tub 6.

The drive mechanism 17 includes: a motor 18, the motor 18 being an outer rotor type DC three-phase brushless motor; a hollow tub shaft 19; a stirring shaft 20, the stirring shaft 20 penetrating through the barrel shaft 19; and a clutch mechanism 21 (shown only in fig. 3), the clutch mechanism 21 selectively transmitting the rotational driving force of the motor 18 to the

shafts

19, 20, and the like. The rotary tub 11 is connected to an upper end of the tub shaft 19, and the stirring body 13 is connected to an upper end of the stirring shaft 20.

The clutch mechanism 21 has a well-known structure using, for example, a solenoid as a drive source, and is switched and controlled by a control device to be described later. The clutch mechanism 21 transmits the driving force of the motor 18 to the agitator 13 via the agitating shaft 20 in a state where the rotary tub 11 is fixed (stopped) during washing and rinsing (washing stroke), and directly drives the agitator 13 to rotate forward and backward at a low speed. In the dewatering process (dewatering stroke), the driving force of the motor 18 is transmitted to the rotary tub 11 via the tub shaft 19 in a state where the tub shaft 19 is coupled to the stirring shaft 20, and the rotary tub 11 (and the stirring body 13) is directly driven to rotate at high speed in one direction.

On the other hand, fig. 2 also shows that: a top cover 22 made of synthetic resin and having a thin hollow box shape. A substantially circular laundry entrance (not shown) is formed in the center of the upper surface of the top cover 22 so as to be positioned above the rotary tub 11, and a double-folding cover 23 (only shown in fig. 1) for opening and closing the laundry entrance is provided. Although not shown, the top cover 22 includes, in a front upper surface portion: an operation panel for the user to select the washing operation course and indicate the operation start.

The top cover 22 is provided at its rear portion with: a water supply mechanism 24 for supplying water into the water tub 6. The water supply mechanism 24 includes a water supply valve 25, a water filling box 26, and a water supply pipe 27 having flexibility, and a tip end portion of the water supply pipe 27 is connected to the water supply port 16. Water supply valve 25 includes a water supply inlet 25a, and to water supply inlet 25 a: a tip end portion of a connection pipe connected to a tap of tap water, not shown. When the water supply valve 25 is opened, water supplied from tap water is supplied from the water supply port 16 into the rotary tub 11 and the water tub 6 through the water filling box 26 and the water supply pipe 27.

In the present embodiment, the electronic unit 30 is provided so as to be positioned at a lower portion of the back wall side in the outer box 2, in this case, at a lower portion of the opening 2 a. Although not shown in detail, the electronic unit 30 is configured to: a power supply circuit 32, an inverter circuit 33 for driving the motor 18, a control device 34, and the like are provided in a case 31 (see fig. 4) having a horizontally long rectangular shape with a thin front-rear direction. The control device 34 is configured to control the entire washing machine 1 mainly by a computer including a CPU, ROM, RAM, and the like.

Although not described in detail, the controller 34 controls the water supply valve 25, the water discharge valve 9, the clutch mechanism 21, the motor 18, and the like based on an operation signal from the operation panel and signals from various sensors, and performs a washing operation including a washing, rinsing, and spin-drying stroke. In the washing stroke, the motor 18 performs forward and reverse rotation at 100 to 150rpm every 1 second to several seconds. In this washing stroke, although the rotation speed is low, the load torque is large and the motor current increases. In the dehydration step, the motor 18 is rotated at about 900rpm at maximum. In this dehydration stroke, although the rotation speed is high, the load torque is small and the motor current is reduced.

Fig. 3 schematically shows the configuration of the control system of the motor 18, and the motor 18 has three-

phase windings

18u, 18v, and 18w, and is driven and controlled by an inverter circuit 33 of a PWM method. The inverter circuit 33 is configured to: three-phase bridging together 6 IGBTs 35a to 35f as semiconductor switching elements; flywheel diodes 36a to 36f are connected between the collector and emitter of each IGBT35a to 35 f. The

phase output terminals

37u, 37v, and 37w of the inverter circuit 33 are connected to the phase terminals (the

phase windings

18u, 18v, and 18w) of the motor 18.

Emitters of the

IGBTs

35d, 35e, and 35f on the lower arm side of the inverter circuit 33 are connected to a dc power supply line 39b (ground line) via shunt resistors (current detection resistors) 38u, 38v, and 38w, respectively. The interconnection points between the emitters of the

IGBTs

35d, 35e, 35f and the

shunt resistors

38u, 38v, 38w are connected to a level shift circuit 40 and an overcurrent comparison circuit 41.

The level shift circuit 40 is configured to: the terminal voltages of the

shunt resistors

38u, 38v, and 38w are level-shifted and amplified, and are supplied to the control device 34 in the form of a current detection signal. In this case, when the

IGBTs

35d, 35e, and 35f on the lower arm side are turned on, the terminal voltages of the

shunt resistors

38u, 38v, and 38w are read into the control device 34. In the present embodiment, the controller 34 determines the temperature of the motor 18 (winding) based on the current value flowing through each phase winding of the motor 18, and constitutes a temperature determination device. In addition, the over-current comparison circuit 41 is configured to: for detecting an overcurrent generated when, for example, the upper and lower arms of the inverter circuit 33 are short-circuited, and when an overcurrent state is detected based on the terminal voltages of the

shunt resistors

38u, 38v, and 38w, an overcurrent detection signal is output to the control device 34.

In the present embodiment, each of the IGBTs 35a to 35f includes: and element temperature detection devices 42a to 42f for directly detecting the temperatures of the IGBTs 35a to 35 f. The element temperature detection devices 42a to 42f are composed of, for example, thermistors, and temperature detection signals thereof are input to the control device 34. Further, the motor 18 is provided with: and a position sensor 43 composed of 3 hall ICs for detecting the rotational position of the rotor. Detection signals of these position sensors 43 are input to the control device 34, and the control device 34 can detect the rotational direction and the rotational position of the motor 18 based on the sensor signals.

A power supply circuit 32 is connected to an input side of the inverter circuit 33. The power supply circuit 32 is configured to: the 100V ac power supply 44 is full-wave rectified by a full-wave rectifier circuit 45 composed of a diode bridge and 2 capacitors 46a and 46b connected in series, and a dc voltage of about 280V is output to the dc

power supply lines

39a and 39 b. The dc power supply line 39b is connected to the ground. The inverter circuit 33 is connected between the dc

power supply lines

39a and 39 b.

The first power supply circuit 47 steps down the driving power of about 280V supplied to the inverter circuit 33 to generate a 15V power, and supplies the 15V power to the control device 34 and the driving circuit 48. The second power supply circuit 49 (control power supply circuit) is: and a three-terminal regulator for generating a control power supply of 3.3V by stepping down the driving power supply and supplying the control power supply to the control device 34. The high voltage excitation circuit 50 is configured to: for driving the upper arm side IGBTs 35 a-35 c in the inverter circuit 33. A series circuit of

resistance elements

51a and 51b is connected between dc

power supply lines

39a and 39b, and a common connection point of both is connected to an input terminal of control device 34.

The controller 34 detects the current flowing through each phase of the inverter circuit 33, that is, the current flowing through each phase winding of the motor 18, via the level shift circuit 40, and performs vector control of the motor 18 based on the detected current value, a speed command supplied from the outside, and the like. At this time, the control device 34 performs voltage phase control to generate PWM signals (energization control signals) of three upper and lower phases of which the voltage rates are changed into sine waves, thereby controlling the inverter circuit 33. In this case, the controller 34 outputs the generated PWM signal to the gates of the IGBTs 35a to 35f of the inverter circuit 33 via the drive circuit 48 and the upper high-voltage excitation circuit 50.

In the present embodiment, the inverter circuit 33, the drive circuit 48, the high-voltage excitation circuit 50, and the like are configured as, for example, 1 power module (IPM) 52. The respective element temperature detection devices 42a to 42f are also included in the power module 52. As shown in fig. 4, the power module 52 is provided to be mounted on the circuit board 53 in the housing 31 of the electronic unit 30. At the same time, heat radiation silicon, not shown, is applied to a heat radiation surface on the outer surface of the power module 52, and a heat sink 54 made of, for example, aluminum is attached through the heat radiation silicon. Although not shown in detail, the housing 31 includes: and a cooling fan 55 (see fig. 3) for supplying cooling air toward the heat sink 54 and the like.

In the present embodiment, as shown in fig. 3, the controller 34 controls the motor 18 via the inverter circuit 33, and controls the drain valve 9, the clutch mechanism 21, the water supply valve 25, the cooling fan 55, and the like. In this case, the control device 34 controls the above-described respective mechanisms mainly by the configuration of software (execution of an operation control program) thereof based on input signals from the respective sensors and the like, and executes a washing operation including, for example, a washing, rinsing, and spin-drying stroke.

As described in the following explanation of the operation, in the present embodiment, the temperatures of the IGBTs 35a to 35f (hereinafter, element temperatures) detected by the element temperature detection devices 42a to 42f are input to the control device 34. At the same time, the controller 34 determines the temperature of the motor 18 (winding) (hereinafter, motor temperature) based on the current values flowing through the

respective phase windings

18u, 18v, and 18w of the motor 18. The control device 34 controls the washing operation based on the element temperature and the motor temperature. Specifically, when one or both of the element temperature and the motor temperature is a high temperature equal to or higher than a threshold value, the control device 34 performs the change control so as to reduce the operation of the motor 18.

As the threshold value, for example, 100 ℃ is used for the element temperature, and 110 ℃ is used for the motor temperature. When the motor temperature is equal to or higher than the threshold value, as control for reducing the operation of the motor 18, the following is performed: setting a stop time of the motor 18, shortening an operation time, performing a dehydration stroke for a long time, and the like. When the element temperature is equal to or higher than the threshold value, as control for reducing the operation of the motor 18, the following is executed: prolonging the time of stoppage (stop) of the motor 18, increasing the air volume of the cooling fan 55, and the like.

In the present embodiment, the controller 34 estimates, based on the element temperature and the motor temperature at the initial stage of the washing stroke: before the washing stroke is completed, whether or not at least one of the motor 18 and the IGBTs 35a to 35f of the inverter circuit 33 exceeds the limit value is determined. If it is predicted that the limit value is exceeded, the control device 34 controls the operation of the motor 18 so that the limit value is not exceeded from the middle of the washing stroke. In this case, when the control device 34 estimates the temperature increase values of the motor 18 and the IGBTs 35a to 35f of the inverter circuit 33, data of the temperature fluctuation of each of the motor 18 and the IGBTs 35a to 35f expected in the washing stroke is stored in the storage unit 56 (see fig. 3) in advance.

Based on the temperature fluctuation data of the IGBTs 35a to 35f stored in the storage unit 56, the control device 34 estimates how much the element temperature rises before the end of the washing stroke, from the element temperature detected in the initial stage of the washing stroke. Similarly, the control device 34 estimates how much the motor temperature rises before the end of the washing stroke, based on the motor temperature detected in the initial stage of the washing stroke, based on the temperature variation data of the motor 18 stored in the storage unit 56. As the limit value, a value equivalent to the above threshold value may be used, for example, 100 ℃ for the element temperature and 110 ℃ for the motor temperature. As the control for reducing the operation of the motor 18, the same control as described above, such as extending the pause (stop) time of the motor 18, may be adopted.

In the present embodiment, the controller 34 is configured to: the inspection mode is executed based on, for example, an operation instruction in the operation panel. In the inspection mode, the control device 34 executes an aging operation (aging) operation to determine whether or not there is an abnormality based on the rise degree of the element temperature and the motor temperature. Whether there is an abnormality is determined by whether or not the element temperature and the motor temperature exceed predetermined ranges. The control device 34 is configured to: if it is determined that there is an abnormality, for example, a warning notification corresponding to the type of the abnormality is given to the operation panel.

More specifically, in the case of the IGBTs 35a to 35f, the IGBT is used in a range of-30 to 130 ℃, and the range is a predetermined range. In the case of the motor 18, it is assumed that the motor is used in a range of-30 to 150 ℃, and the range is a predetermined range. When only the element temperature exceeds the predetermined range, it is determined that the power module 52 or the heat sink 54 is not properly mounted (the heat sink silicon is not properly applied), and the notification is given. When only the motor temperature exceeds the predetermined range, it is determined that there is an abnormality such as a short circuit of the winding in the motor 18, and notification of the abnormality is prompted. When both the element temperature and the motor temperature exceed the predetermined ranges, it is determined that there is a defect (failure) in the bearings of the drive mechanism 17, and the notification of the defect is prompted.

Next, the operation of the washing machine 1 configured as described above will be described with reference to fig. 5 to 8. In the washing machine 1 configured as described above, the element temperatures of the IGBTs 35a to 35f of the inverter circuit 33 are detected, and the motor temperature of the motor 18 is determined by the control device 34. The control device 34 controls the motor 18 based on these element temperatures and the motor temperature, and performs the washing operation. At this time, since the control can be performed using both the element temperature and the motor temperature, the control device 34 can prevent abnormal temperature increases of the IGBTs 35a to 35f and the winding of the motor 18, and can operate the IGBTs 35a to 35f and the motor 18 with maximum performance until each temperature approaches the limit value.

Here, there are characteristic situations in the washing machine 1 in which control can be performed in consideration of these situations. That is, the windings of the motor 18 have characteristics of being easily heated and easily cooled, and the IGBTs 35a to 35f of the inverter circuit 33 have characteristics of being not easily heated and not easily cooled. In addition, during the washing operation, there are cases where: although the washing, rinsing, and dewatering processes are performed, the temperature of the motor 18 is more likely to rise in the washing process than in the dewatering process, and the temperature rising in the washing process can be naturally reduced by the motor 18 receiving, for example, cooling air due to the rotation of the rotary tub 11 in the dewatering process.

Fig. 5 shows an example of the results obtained by examining the change in the element temperature and the motor temperature when the washing operation is continuously repeated 3 times in the washing machine 1. From this fig. 5 it can also be understood that: the temperature of the motor 18 is likely to rise during the washing stroke; the temperature of the motor is reduced in the dehydration stroke; and a second temperature higher than the first temperature and a third temperature higher than the second temperature for both the element temperature and the motor temperature.

In this case, the washing machine 1 is designed as follows: even if the continuous operation is performed 3 times, the element temperature is suppressed to be not more than the threshold value (100 ℃) and the motor temperature is suppressed to be not more than the threshold value (110 ℃). However, the element temperature or the motor temperature may be equal to or higher than a threshold value due to an external environment, aged deterioration of components, a failure, a user's use method, or the like. For example, in the case where the user uses a method of performing only the washing stroke and then performing the washing stroke, the temperature of the motor may be increased more significantly than that in fig. 5.

Then, when at least one of the element temperature and the motor temperature is equal to or higher than the threshold value, the controller 34 performs the following control: the control of the washing operation is changed mainly by reducing the operation of the motor 18. For example, when the motor temperature is increased, the motor temperature can be effectively lowered by extending the time of the dehydration stroke or the off time of the motor 18. When the element temperature is high, the temperature of the IGBTs 35a to 35f can be effectively lowered by prolonging the time for which the motor 18 is not energized, such as by prolonging the water supply time, or by increasing the air volume of the cooling fan 55 for cooling the power module 52.

As described above, the controller 34 estimates the degree of temperature increase of the IGBTs 35a to 35f of the motor 18 and the inverter circuit 33 before the end of the washing stroke, based on the element temperature detected in the initial stage of the washing stroke (for example, in the initial 1/3 time period with respect to the time of the entire washing stroke), the motor temperature, and the temperature fluctuation data stored in the storage unit 56. When it is predicted that at least one of the motor 18 and the IGBTs 35a to 35f exceeds the limit value (threshold value), the control device 34 performs control to reduce the operation of the motor 18 so as not to exceed the limit value from the middle of the washing stroke (for example, after 1/3 has elapsed with respect to the time of the entire washing stroke).

Here, fig. 6 shows the variation of the element temperature and the motor temperature in the washing stroke of about 15 minutes when the first washing stroke is performed, for example. The element temperature and the motor temperature at the initial stage of the washing stroke were both about 30 ℃, and based on these temperatures, the following were determined: both the element temperature and the motor temperature can be controlled in a normal manner without any problem in the washing stroke. Therefore, in this case, the control for reducing the operation of the motor 18 is not necessary.

In contrast, fig. 7 shows the variation of the element temperature and the motor temperature in the first washing stroke when the washing operation is repeated, for example. Here, the motor temperature is high, about 40 ℃, and the element temperature is as high as approximately 50 ℃ in the initial stage of the washing stroke. In this case, the prediction is: if the usual control is continued, the motor temperature may exceed a limit value (110 c), for example. Therefore, the controller 34 performs control to reduce the operation of the motor 18, for example, control to make the pause (stop) time of the motor 18 longer than normal from the middle of the washing stroke, for example, from the left and right of 5 minutes shown by symbol a in the figure. Thus, even when the motor temperature (or the element temperature) at the initial stage of the washing stroke is high, abnormal temperature increases of the motor 18 and the IGBTs 35a to 35f can be prevented.

In the present embodiment, for example, in the inspection step before shipment of the product, based on an input operation of the operation panel by the operator, the control device 34 executes: and an inspection mode for inspecting a temperature rise of the motor 18 and the IGBTs 35a to 35 f. The flowchart of fig. 8 shows a processing sequence executed by the control device 34 in the inspection mode. That is, when the inspection mode is input in step S1, the burn-in operation is executed in step S2 to check the element temperature and the motor temperature after the burn-in operation.

In the next step S3, it is determined whether or not only the element temperature exceeds a predetermined range (for example, a range of-30 to 130 degrees celsius) set in advance. When the element temperature exceeds the predetermined range (Yes in step S3), in step S4, for example, an operation panel is displayed to prompt notification of: with the contents of the power module 52 or the heat sink 54 being improperly installed. In step S5, it is determined whether only the motor temperature exceeds a predetermined range (e.g., a range of-30 to 150 ℃ C.). When the motor temperature exceeds the predetermined range (Yes in step S5), in step S6, for example, an operation panel is displayed to prompt notification of: the motor 18 or the wire has the content of an undesirable condition.

In step S7, it is determined whether both the element temperature and the motor temperature exceed a predetermined range. If both the element temperature and the motor temperature exceed the predetermined ranges (Yes in step S7), in step S8, for example, an indication of a defect in the bearing or the wire harness of the driving mechanism 17 is notified by a display on the operation panel. If the temperature of the element and the temperature of the motor do not exceed the predetermined ranges (No in step S7), it is determined to be normal, and the inspection mode is ended as it is. In this way, in the inspection mode, when an abnormality is determined, the operator can promptly take appropriate measures because the operator performs the notification of the abnormality in accordance with the type of the abnormality.

Thus, according to the washing machine 1 of the present embodiment, the following effects can be obtained. That is, in the present embodiment, the control device 34 controls the washing operation using both the motor temperature of the motor 18 and the element temperatures of the IGBTs 35a to 35f of the inverter circuit 33, and therefore, it is possible to prevent an abnormal temperature rise and to operate the inverter circuit 33 and the motor 18 with maximum performance until the respective temperatures approach the limit values. As a result, according to the present embodiment, the winding of the motor 18 and the IGBTs 35a to 35f of the inverter circuit 33 can be effectively protected against temperature abnormality.

At this time, the controller 34 changes the control so as to reduce the operation of the motor 18 when the temperature is high, in which one or both of the element temperature and the motor temperature are equal to or higher than the threshold value. This can effectively reduce the temperature of the motor 18 and the IGBTs 35a to 35f of the inverter circuit 33, and can protect the motor 18 and the inverter circuit 33.

In particular, in the present embodiment, the controller 34 is configured to: whether at least one of the element temperature and the motor temperature exceeds a limit value before the end of the washing stroke is estimated based on the element temperature and the motor temperature at the initial stage of the washing stroke, and if the limit value is predicted to be exceeded, the control is changed from the middle of the washing stroke so as to weaken the operation of the motor. This prevents abnormal temperature increases in the motor 18 and the IGBTs 35a to 35f, and enables the washing stroke to be performed efficiently with high power.

In particular, in the present embodiment, the controller 34 is configured to: in the inspection mode, an abnormality is determined based on the temperature of the element and the degree of increase in the temperature of the motor, and a notification corresponding to the type of the abnormality is given. Thus, it is possible to determine an abnormality with high certainty based on the degree of increase in the element temperature and the motor temperature, and if it is determined that an abnormality has occurred, a notification is given in accordance with the type of the abnormality, so that appropriate measures can be taken quickly.

In the above-described embodiment, the control device is configured to determine the motor temperature based on the current value flowing in the motor (winding), but a configuration may be adopted in which the temperature of the motor is directly detected by a sensor or the like. The limit value and the threshold value are set to the same temperature, but the threshold value may be set to a value smaller than the limit value. Although the above embodiment is applied to a vertical axis type washing machine, the present invention may be applied to a horizontal axis type (so-called drum type) washing machine. The specific values of temperature, time, and the like described in the above embodiments are merely examples, and may be implemented by appropriately changing the values.

The above embodiments are presented as examples and are not intended to limit the scope of the invention. These new embodiments may be implemented in other various forms, and various omissions, substitutions, and changes may be made without departing from the spirit of the invention. The present embodiment and its modifications are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalent scope thereof.

Claims

1. A washing machine, characterized by comprising:

a motor;

an inverter circuit including a switching element for driving the motor;

a control device for controlling the motor to execute washing operation including a washing stroke and a dewatering stroke;

an element temperature detection device that detects a temperature of the switching element; and

a motor temperature determination device that determines a temperature of the motor,

the control means controls the washing operation based on the element temperature detected by the element temperature detecting means and the motor temperature determined by the motor temperature determining device,

when the motor temperature is equal to or higher than a threshold value, control is performed to extend the time of the dehydration stroke.

2. A washing machine, characterized by comprising:

a motor;

an inverter circuit including a switching element for driving the motor;

a control device for controlling the motor to execute washing operation including a washing stroke;

the control device estimates whether or not at least one of the motor temperature and the element temperature exceeds a limit value before the end of a washing stroke based on temperature fluctuations of the motor and the switching element, respectively, which are expected during the washing stroke, and the element temperature and the motor temperature at the initial stage of the washing stroke, and controls the operation of the motor so as not to exceed the limit value from the middle of the washing stroke when the limit value is predicted to be exceeded.

3. A washing machine according to claim 1 or 2,

the control device changes control so as to reduce the operation of the motor when either or both of the element temperature and the motor temperature is a high temperature equal to or higher than a threshold value.

4. A washing machine according to claim 1 or 2,

the control device judges the abnormality according to the rising degree of the element temperature and the motor temperature, and prompts and informs corresponding to the abnormal type.

5. A washing machine according to claim 3,