Washing machine

Abstract

The present invention provides a washing machine that can maintain the cleanliness of a water tank and a washing tub without excessively increasing the electricity cost. The washing machine includes: a water tank; a washing tub rotatably supported within the water tank; a motor (17) that rotationally drives the washing tub; a heater (19) that heats the water within the water tank; a sensor (33) that detects the temperature within the water tank or the washing tub; and a control unit (21) that controls the driving of the heater (19). The control unit (21) is controlled to automatically perform a first steam cleaning and a second steam cleaning regularly. The first steam cleaning generates water vapor through the heater (19) to make the temperature within the washing tub reach a first temperature, and the second steam cleaning generates water vapor through the heater (19) to make the temperature within the washing tub reach a second temperature higher than the first temperature.

Description

Technical Field

[0001] The present invention relates to a washing machine having a sterilization function for a washing tub. Background Art

[0002] As a washing machine having a sterilization function, for example, there has been proposed a washing and drying machine in which "in a washing and drying machine equipped with a heating unit, a blowing unit, a water supply unit, a temperature detection unit, etc., the temperature in the washing tub is increased by using the heating unit and the blowing unit, and water is supplied to the heating unit or the washing tub, etc. for humidification, thereby performing cleaning and sterilization control of the washing tub" (see Patent Document 1).

[0003] Prior Art Documents

[0004] Patent Documents

[0005] Patent Document 1: Japanese Patent Laid-Open No. 2005-253584

[0006] However, if the user forgets to perform the cleaning and sterilization operation of the washing tub, molds and bacteria will be generated in the washing tub. In addition, once molds are generated, it is difficult to easily remove them.

[0007] On the other hand, if cleaning and sterilization are automatically performed every time after the washing operation, the electricity cost required to make the inside of the washing tub a high-temperature and high-humidity environment increases. Summary of the Invention

[0008] The present invention has been made to solve the above problems, and an object thereof is to provide a washing machine that can maintain the cleanliness of the water tank and the washing tub without excessively increasing the electricity cost.

[0009] The washing machine according to one aspect of the present invention includes: a water tank; a washing tub rotatably supported in the water tank; a motor that rotationally drives the washing tub; a heater that heats the water in the water tank; a sensor that detects the temperature in the water tank or the washing tub; and a control unit that controls the driving of the heater, and the control unit controls to automatically perform a first steam cleaning and a second steam cleaning periodically. In the first steam cleaning, water vapor is generated by the heater to make the temperature in the washing tub a first temperature, and in the second steam cleaning, water vapor is generated by the heater to make the temperature in the washing tub a second temperature higher than the first temperature.

[0010] Advantages of the Invention

[0011] The washing machine according to the above aspect can maintain the cleanliness of the water tank and the washing tub without excessively increasing the electricity cost. Brief Description of the Drawings

[0012] Figure 1 is a schematic perspective view showing the external structure of the washing machine according to the first embodiment.

[0013] Figure 2 is a first schematic cross-sectional view showing the internal structure of the washing machine.

[0014] Figure 3 is a second schematic cross-sectional view showing the internal structure of the washing machine.

[0015] Figure 4 is a block diagram showing a part of the structure related to the control of the washing machine.

[0016] Figure 5 is a flowchart of the cleaning process executed by the control unit of the washing machine.

[0017] Figure 6 is a flowchart of the first steam cleaning process executed by the control unit of the washing machine.

[0018] Figure 7 is a flowchart of the second steam cleaning process executed by the control unit of the washing machine.

[0019] Figure 8 is a block diagram showing a part of the structure related to the control of the washing machine according to the second embodiment.

[0020] Figure 9 is a flowchart of the cleaning process executed by the control unit.

[0021] Symbol Explanation

[0022] 1 Washing machine

[0023] 10 Housing

[0024] 13 Water tank

[0025] 15 Washing tub

[0026] 17 Motor

[0027] 19 Heater

[0028] 21 Control unit Detailed Embodiment

[0029] (Overview)

[0030] A first washing machine according to one embodiment includes: a water tank; a washing tub rotatably supported within the water tank; a motor that rotationally drives the washing tub; a heater that heats water within the water tank; a sensor that detects the temperature within the water tank or within the washing tub; and a control unit that controls the driving of the heater. The control unit is configured to automatically perform a first steam cleaning and a second steam cleaning periodically. The first steam cleaning generates steam by the heater to make the temperature within the washing tub reach a first temperature, and the second steam cleaning generates steam by the heater to make the temperature within the washing tub reach a second temperature higher than the first temperature. Thus, the steam cleaning is automatically performed periodically regardless of the presence or absence of user operation, so that the washing tub and the water tank can be kept clean. In addition, by performing the first steam cleaning with a certain (specified) cleaning effect at regular intervals and the second steam cleaning with an expected higher effect, the cleanliness of the washing tub and the interior of the water tank can be maintained. Furthermore, the expressions "make the temperature within the washing tub reach the first temperature" and "make the temperature within the washing tub reach the second temperature" mentioned here have the same meaning as "make the temperature within the water tank reach the first temperature" and "make the temperature within the water tank reach the second temperature".

[0031] A second washing machine according to another embodiment of the present invention is the first washing machine, wherein the control unit maintains the state at the first temperature during the first steam cleaning for a first time period or longer, and maintains the state at the second temperature during the second steam cleaning for a second time period or longer, and the second time period is longer than the first time period. Thus, the first steam cleaning can be completed in a short time. By performing the second steam cleaning, which has a higher electricity cost, less frequently, the electricity cost (operating cost) can be reduced.

[0032] A third washing machine according to another embodiment of the present invention is the first or second washing machine, wherein the control unit performs the first steam cleaning at a first cycle and the second steam cleaning at a second cycle, and the second cycle is longer than the first cycle. Thus, the steam cleaning is automatically performed periodically regardless of the presence or absence of user operation, so that the washing tub and the water tank can be kept clean. By performing the first steam cleaning with a certain cleaning effect at regular intervals and the second steam cleaning with an expected higher effect, the cleanliness of the washing tub and the interior of the water tank can be maintained.

[0033] A fourth washing machine according to another embodiment of the present invention is the third washing machine, wherein the length of the second cycle is three times or more the length of the first cycle. Thus, the electricity cost can be reduced.

[0034] The fifth washing machine related to other embodiments is any one of the first to fourth washing machines, where the control unit controls water supply and drainage. During the first steam cleaning and the second steam cleaning, water in the range of 1.9 L or more and 2.3 L or less is supplied to the water tank. Thereby, it is possible to suppress mold and the like with a smaller amount of water, and it is possible to suppress water and electricity bills. In addition, since less water is heated, the temperature can be raised in a short time.

[0035] The sixth washing machine related to other embodiments is any one of the first to fourth washing machines, where the control unit controls water supply and drainage. During the first steam cleaning and the second steam cleaning, water is supplied to the water tank such that the water level in the water tank is in the range of 5 mm or more and 15 mm or less with respect to the upper surface of the heater. Thereby, it is possible to suppress mold and the like with a smaller amount of water, and it is possible to suppress water and electricity bills. Since less water is heated, the temperature can be raised in a short time. Since the water covers the heater, it is possible to prevent dry burning of the heater and to reliably perform steam cleaning.

[0036] The seventh washing machine related to other embodiments is any one of the first to fourth washing machines, where the rotation axis of the washing machine is horizontal or inclined within a range of 10 degrees or less with respect to the horizontal. The control unit controls water supply and drainage. During the first steam cleaning and the second steam cleaning, water is supplied to the water tank in a range where the washing tub does not immerse. Thereby, it is possible to suppress mold and the like with a smaller amount of water, and it is possible to suppress water and electricity bills. Since less water is heated, the temperature can be raised in a short time. Although the amount of water is small, it is also possible to prevent dry burning of the heater. Since the supplied water does not contact the washing tub, the heat energy during heating is not taken away by the washing tub, and the water can be effectively heated, so that the cost can be suppressed.

[0037] The eighth washing machine related to other embodiments is any one of the first to seventh washing machines, and the water level of the water tank is detected by a semiconductor type water level sensor. Thereby, even a small amount of water can be detected with high precision for the water supply amount.

[0038] The ninth washing machine related to other embodiments is any one of the first to eighth washing machines, and the control unit rotates the washing tub during the first steam cleaning and the second steam cleaning. Thereby, the generated water vapor can be evenly diffused in a short time. That is, a uniform humid-heat environment can be achieved.

[0039] The tenth washing machine related to other embodiments of the embodiment is any one of the first to eighth washing machines. In the first steam cleaning and the second steam cleaning, the control unit rotates the washing tub within a range of 300 rpm or more and 500 rpm or less. Thereby, the time required to optimize and achieve a uniform hot and humid environment can be achieved.

[0040] The eleventh washing machine related to other embodiments of the embodiment is any one of the first to tenth washing machines. In the first steam cleaning and the second steam cleaning, when starting the cleaning operation, the control unit causes the notification unit to notify of this operation. Thereby, the user can visually recognize that the steam cleaning is automatically started regularly.

[0041] The twelfth washing machine related to other embodiments of the embodiment is the eleventh washing machine. In the first steam cleaning and the second steam cleaning, the control unit causes the notification unit to notify in different notification manners. Thereby, the user can grasp that the steam cleaning is automatically started regularly, and whether the steam cleaning is the first steam cleaning or the second steam cleaning.

[0042] <First Embodiment>

[0043] 1. Schematic Structure

[0044] Use Figures 1 to 3 The schematic structure of the washing machine 1 according to the first embodiment will be described.

[0045] In addition to the washing function (in some cases, including the dehydration function), the washing machine 1 also has a steam cleaning function using steam. There are a first steam cleaning and a second steam cleaning, and these cleaning processes are automatically performed regularly. In addition, when it is not necessary to distinguish between the first steam cleaning and the second steam cleaning, it is simply referred to as steam cleaning.

[0046] Here, the washing machine 1 is a so-called drum type (horizontal type) in which the central axis of the washing tub 15 is arranged in the horizontal direction. In addition, the steam cleaning can also be implemented in a vertical washing machine, but considering the heating efficiency during cleaning, a drum type with high airtightness inside the machine is preferred.

[0047] As Figure 1 shown, the washing machine 1 includes a housing 3 having a substantially rectangular parallelepiped shape. A door 5 for opening and closing the opening of the washing tub 15 is provided on the front surface of the housing 3.

[0048] An interface unit 7 and a detergent input unit 8 are provided above the door 5 of the housing 3. Only a part of the interface unit 7 is exposed on the front upper surface of the housing 3. The interface unit 7 has an operation unit 9 for the user to operate the washing operation, and a display unit 11 for displaying the user's operation input content, operation status (including steam cleaning operation), and the like.

[0049] The operation unit 9 has functions such as power on / off, operation start / pause, and selection of the washing process. In addition, since the steam cleaning is automatic, there is no operation (selection) device for the user to operate (select). However, an operation device for manually performing steam cleaning may be further provided.

[0050] The display unit 11 has a notification device 12 for notifying the steam cleaning operation. Here, an LED is used as the notification device 12, which lights up (“first display”) during the first steam cleaning operation and blinks (“second display”) during the second steam cleaning operation, enabling the user to identify which steam cleaning the washing machine 1 is performing.

[0051] As Figure 2 、 Figure 3 shown, inside the housing 3, at least the following are accommodated: a water tank 13 for storing washing water, etc., a washing tub 15 rotatably supported inside the water tank 13 into which the laundry is put, a motor 17 for rotationally driving the washing tub 15, a heater 19 for heating the water in the water tank 13, and a control unit 21 for performing rotation control of the motor 17, heating control of the heater 19, etc. In addition, to distinguish from the drying heater described later, the heater 19 is designated as a hot water heater 19.

[0052] As Figure 2 and Figure 3 shown, the hot water heater 19 is arranged inside the water tank 13 and outside the washing tub 15. That is, it is provided between the peripheral wall of the water tank 13 and the peripheral wall of the washing tub 15 and at the lowermost part of the water tank 13. Thereby, the water in the water tank 13 can be effectively heated. The hot water heater 19 uses a sheathed heater, for example, and is arranged in a manner extending parallel to the rotation axis of the washing tub 15. When viewed from above, the sheathed heater is, for example, in a “W” shape.

[0053] In addition to the washing function, dehydration function, and cleaning function (including steam cleaning), the washing machine 1 also has a drying function. As Figure 2 and Figure 3 shown, inside the housing 3, there are provided: a blower fan 25, a blower duct 27, a drying heater, a heat exchanger 29, an air filter, etc.

[0054] The steam cleaning function is performed by generating steam in the machine body using the hot water heater 19. In addition, the steam cleaning will be described later.

[0055] The driving power for the motor 17, hot water heater 19, air supply fan 25, drying heater, display unit 11, control unit 21, etc. for realizing functions such as washing is supplied by the power supply unit 34. The washing operation and drying operation are performed after the power switch (selection device) of the operation unit 9 is turned on, but the cleaning function is configured to be able to receive power from the power supply unit 34 even in the state where the power switch is turned off (OFF). In addition, during a power outage, power is supplied from the battery 35 to the calendar unit 45 of the control unit 21.

[0056] To realize the above functions, or at least the washing function and the cleaning function, the washing machine 1 is provided with a water level sensor 31, a temperature sensor 33, etc.

[0057] The water level sensor 31 is provided in the interface unit 7, and here, a semiconductor type water level sensor is used. Thus, even when the water level is low (the amount of water is small), the water level can be detected with high accuracy.

[0058] The temperature sensor 33 is provided in the water tank 13 and detects the ambient temperature and water temperature inside the washing tank 15 (or a part equivalent to the inside of the washing tank 15).

[0059] 2. Control of the washing machine 1

[0060] (1) Outline

[0061] Here, the control regarding steam cleaning is described.

[0062] The control unit 21 performs steam cleaning processing for cleaning the water tank 13 and the washing tank 15 by generating water vapor through the hot water heater 19. That is, it controls the water supply and drainage to the water tank 13 and the driving (turning on or off) of the hot water heater 19. Since this steam cleaning processing is performed while rotating the washing tank 15, the control unit 21 controls the driving of the motor 17, etc. (turning on, turning off, rotation speed).

[0063] During steam cleaning, there are a first steam cleaning that makes the temperature inside the washing tank 15 (or a part equivalent to the inside) the first temperature, and a second steam cleaning that makes the temperature inside the washing tank 15 (or a part equivalent to the inside) a second temperature higher than the first temperature.

[0064] More specifically, the temperature inside the washing tank 15 is controlled using the temperature sensor 33 provided in the water tank 13 (refer to Figure 4 ), and the temperatures in the water tank 13 corresponding to the first temperature and the second temperature are set in advance through experiments, etc. (for example, temperatures higher than the first temperature and the second temperature).

[0065] Here, the first temperature is the temperature capable of sterilizing molds, and the second temperature is the temperature capable of removing yeasts, etc., in other words, the temperature capable of preventing or suppressing the formation of biofilms due to yeasts, etc. As an example, the first temperature is 50 °C and the second temperature is 60 °C. Thus, it is possible to sterilize the generated molds or prevent (suppress) the formation of biofilms.

[0066] The control unit 21 performs the first steam cleaning process and the second steam cleaning process regularly and automatically. Here, "regularly" means before the molds cannot be removed in the first steam cleaning process and before biofilms are likely to form in the second steam cleaning process. Thus, steam cleaning can be performed without the operation of the user, and the sink 13 and the washing tank 15 can be maintained clean.

[0067] In the first steam cleaning, the control unit 21 maintains the state at the first temperature for more than the first time, and in the second steam cleaning, it maintains the state at the second temperature for more than the second time. Here, the second time is longer than the first time. The first time is the time capable of removing molds. The second time is the time capable of removing bacteria other than yeasts and molds (such as yeasts) that cannot be removed in the first steam cleaning, suppressing the formation of biofilms by yeasts, etc., and also the time for killing molds that are not killed in the first steam cleaning.

[0068] The first time also includes 0 seconds. For example, the hot water heater 19 can also be turned off at the moment when the first temperature is detected. That is, the first time can also be 0 seconds.

[0069] As an example of the first time and the second time, the first time is 0 seconds and the second time is 10 minutes.

[0070] When the first temperature is 50 °C, molds are usually killed in the state of reaching this 50 °C, so it is possible to sterilize molds effectively and economically. When the second temperature is 60 °C, by maintaining this 60 °C for 10 minutes, it is possible to remove yeasts, etc. other than molds that could not be cleaned thoroughly in the first steam cleaning, and prevent the formation of biofilms from yeasts, etc. on the sink 13 or / and the washing tank 15. In addition, even if a biofilm is formed by chance, it is possible to effectively kill the molds that have penetrated into the biofilm, so it is possible to prevent the generation of black molds or prevent the proliferation of the biofilm itself by removing yeasts, etc.

[0071] The control unit 21 performs the first steam cleaning process and the second steam cleaning process periodically. Specifically, the first steam cleaning process is performed at the first cycle, and the second steam cleaning process is performed at the second cycle. Here, the second cycle is longer than the first cycle. The second cycle is preferably more than three times the first cycle.

[0072] The first cycle is preferably within the range of more than three days and less than seven days (one week). If it is longer than one week, even if the first steam cleaning is carried out at 50 °C, more mildew remains due to attachment to the laundry, etc. If it is shorter than three days, although mildew can be sterilized, the economic burden (electricity cost) increases.

[0073] The second cycle is preferably within the range of more than three weeks and less than five weeks. If it is longer than five weeks, biofilms form over a large area in the water tank 13 or / and the washing tank 15, increasing the likelihood of black mildew generation. If it is shorter than three weeks, although the formation of biofilms can be inhibited, the economic burden (electricity cost) increases.

[0074] As an example, the first cycle is one week, the second cycle is four weeks, and the second cycle is four times the first cycle. In addition, when the first cycle and the second cycle overlap, the second steam cleaning is preferentially carried out.

[0075] In the control of water supply and drainage, the control unit 21 supplies a water volume in the range of 1.9 L or more and 2.3 L or less for the first steam cleaning process and the second steam cleaning process, for example. Thereby, the water for steam cleaning can be ensured, and steam cleaning can be reliably carried out. In addition, while suppressing the electricity / water cost (reducing costs), steam can be generated in a short time. In this case, the structure of the water tank 13 in which the hot water heater 19 is completely immersed in the supplied water and also completely immersed after steam generation is required.

[0076] The control unit 21 supplies a water volume in the range of 5 mm or more and 15 mm or less above the upper surface of the hot water heater 19 to the water level in the water tank 13 for the first steam cleaning process and the second steam cleaning process. Thereby, regardless of the capacity of the water tank 13, dry burning of the hot water heater 19 can be prevented, and safety can be improved.

[0077] In the first steam cleaning process and the second steam cleaning process, the control unit 21 supplies a water volume in a range where the washing tank 15 is not immersed. Thereby, the heating energy of the hot water heater 19 can be prevented from being conducted to the washing tank 15 side, and steam can be generated effectively and economically.

[0078] The control unit 21 controls water supply and drainage via the water supply valve 36 and the drain valve 37.

[0079] The control unit 21 rotates the washing tub 15 during the first steam cleaning process and the second steam cleaning process. Thereby, it is possible to clean the entire water tank 13 and the washing tub 15. In addition, it is possible to equalize the temperature inside the water tank 13 and the washing tub 15, and obtain a sterilization effect over a large range of the entire water tank 13 and the washing tub 15. The rotation of the washing tub 15 is preferably in the range of 300 rpm or more and 500 rpm or less. As an example, it rotates at 400 rpm. Thereby, it is possible to reduce the temperature unevenness inside the water tank 13 and the washing tub 15.

[0080] (2) Structure

[0081] Use Figure 4 Describe the structure related to the control of the washing machine 1. In addition, in Figure 4 It is illustrated centering on the structure related to the steam cleaning process of the washing machine 1.

[0082] As Figure 4 shown, signals are input to the control unit 21 from the operation unit 9, the water level sensor 31, and the temperature sensor 33 in a timely manner. Based on the input signals, the control unit 21 outputs signals to the motor 17, the hot water heater 19, the display unit 11, the water supply valve 36, and the drain valve 37 in a timely manner. In addition, the control unit 21 receives power supply from the power supply unit 34. In addition, the calendar unit 45 receives power supply from the battery 35 when there is no power supply from the power supply unit 34.

[0083] The control unit 21 includes: a control unit 41, a storage unit 43, a calendar unit 45, and a timer 47. The control unit is configured to include a CPU and the like. The control unit 41 executes a corresponding program according to the operation of the user on the operation unit 9. The storage unit 43 is configured to include an EEPROM, a RAM, a ROM, and the like. The storage unit 43 stores programs and data for washing, dehydrating, drying, and steam cleaning.

[0084] The calendar unit 45 has a clock function, can count the year, month, and day by measuring time, detect a first period for performing the first steam cleaning operation and a second period for performing the second steam operation set in advance, and output to the control unit 41. In addition, as Figure 5 shown, when the calendar unit 45 here becomes the first period, it outputs a first signal to the control unit 41 notifying that it has become the period for performing the first steam cleaning, and when it becomes the second period, it outputs a second signal to the control unit 41 notifying that it has become the period for performing the second steam cleaning.

[0085] (3) Process

[0086] (3-1) Overall

[0087] Use Figure 5 Describe the cleaning process performed by the control unit 21.

[0088] The timing of cleaning is illustrated with specific examples. The first steam cleaning process is performed once a week, and the second steam cleaning process is performed once every four weeks. In this example, the 3rd, 10th, 17th, and 24th of May on Monday are the periods for the first steam cleaning process, and the 24th of May, which is the Monday of the fourth week of May, is the period for the second steam cleaning process. In addition, May 24th is the period for the first steam cleaning process, but in the case where the periods of the first steam cleaning process and the second steam cleaning process overlap, only the second steam cleaning process is implemented.

[0089] The calendar unit 45 is configured to be able to process independently of the control unit 41.

[0090] When it reaches May 3rd, the calendar unit 45 determines that it is not the second period (May 24th) ( "No" in S1) but determines that it is the first period (May 3rd) ( "Yes" ) in step S2, so it outputs the first signal to the control unit 41 (S4). Similarly, when it reaches May 10th and 17th, the first signal is output to the control unit 41 in step S4 (S4).

[0091] When it reaches May 24th, the calendar unit 45 determines that it is the second period (May 24th) ( "Yes" ) in step S1, so it outputs the second signal to the control unit 41 (S3).

[0092] When the second signal is output in step S3, it returns to step S1. The calendar unit 45 only executes once at a specified time of day (for example, 16:00). Figure 5 The shown process. Thus, it is possible to prevent the same signal from being output to the control unit 41 and to prevent the first signal from being output during the second period (May 24th) that overlaps with the first period.

[0093] When the control unit 41 determines that there is a signal input in step S11 ( "Yes" ), it confirms whether it is in the middle of washing. In addition, the washing here includes washing, dehydration, drying, etc.

[0094] In the case of being in the middle of washing ( "Yes" in S13), it waits until the washing is over ( "No" in S14), and if the washing is over ( "Yes" in S14), it determines whether the input signal from the calendar unit 45 is the first signal or the second signal (S15).

[0095] In the case where the determination in step S15 is the first signal ( "No" ), it performs the first steam cleaning process described later (S16), resets the input signal (S18), and returns to step S11. In addition, the reset of the input signal is for preventing the steam cleaning process from being performed again because it is determined that there is an input signal in step S11 after the steam cleaning process is over.

[0096] In the case where the determination in step S15 is the second signal ("Yes"), the subsequent second steam cleaning process (S17) is performed, the input signal is reset (S18), and the process returns to step S11.

[0097] (3-2) First steam cleaning process

[0098] Use Figure 6 To describe the first steam cleaning process.

[0099] When the first steam cleaning process starts, the control unit 41 causes the notification device 12 of the display unit 11 to start displaying (notifying) the first display during the operation of the first steam cleaning (S21). Specifically, for example, the LED as an example of the notification device 12 is lit.

[0100] The control unit 41 supplies a predetermined amount of water into the water tank 13 (S22). Specifically, it is performed by opening and closing the water supply valve 36 and the drain valve 37 and the water level sensor.

[0101] When the water supply ends, the control unit 41 starts (turns on) the hot water heater 19 and the rotation of the washing tank 15 to generate steam, and when the detected temperature of the temperature sensor 33 reaches the first temperature (for example, 50 °C) ("Yes" in S24), it stops (turns off) the rotation of the hot water heater 19 and the washing tank 15 (S25).

[0102] After that, the control unit 41 causes the notification device 12 of the display unit 11 to end the first display (S26), drains the water in the water tank 13 (S27), and returns to Figure 5 step S16.

[0103] (3-3) Second steam cleaning process

[0104] Use Figure 7 To describe the second steam cleaning process.

[0105] When the second steam cleaning process starts, the control unit 41 causes the notification device 12 of the display unit 11 to start displaying (notifying) the second display during the operation of the second steam cleaning (S31). Specifically, the LED as an example of the notification device 12 is caused to blink.

[0106] In step S32, when a predetermined amount of water is supplied into the water tank 13, the rotation of the hot water heater 19 and the washing tank 15 is started (S33) to generate steam, and when the detected temperature of the temperature sensor 33 becomes the second temperature (for example, 60 °C) ("Yes" in S34), the hot water heater 19 is turned off (S35).

[0107] In step S36, the timer 47 is started, and until the elapse of a second time (e.g., 10 minutes) (No in S37), the hot water heater 19 is repeatedly turned on / off to maintain the temperature in the washing tub 15 (S41). When the second time has elapsed (Yes in S37), the timer 47 is turned off, and the hot water heater 19 and the rotation of the washing tub 15 are stopped (S38).

[0108] After that, the control unit 41 causes the notification device 12 of the display unit 11 to end the second display (S39), discharges the water in the water tank 13 (S42), and returns to Figure 5 step S17.

[0109] <Second Embodiment>

[0110] The control unit 21 of the first embodiment includes a calendar unit 45. When it becomes the first period or the second period, the calendar unit 45 outputs a first signal or a second signal to the control unit 41. However, it may also be configured such that the first steam cleaning process and the second steam cleaning process are performed regularly and automatically without having a calendar unit. This method is taken as the second embodiment and is described using Figure 8 and Figure 9 for explanation.

[0111] 1. Structure of the Control Unit

[0112] As Figure 8 shown, the control unit 121 has: a control unit 141, a storage unit 43, a first timer 145, a second timer 146, and a timer 47.

[0113] The first timer 145 and the second timer 146 correspond to the calendar unit 45 of the first embodiment. Similarly to the first embodiment, the control unit 141 is configured to include a CPU or the like, and selectively performs the first steam cleaning process and the second steam cleaning process based on the time measured by the first timer 145 and the second timer 146.

[0114] The first timer 145 and the second timer 146 receive driving power from the battery 35 in the absence of power supply from the power supply unit 34. The first timer 145 is used to notify the period for performing the first steam cleaning process, and the second timer 146 is used to notify the period for performing the second steam cleaning process.

[0115] 2. Second Steam Cleaning Process

[0116] Using Figure 9 to explain the cleaning process performed by the control unit 121.

[0117] The timing of cleaning is described using specific examples. The first steam cleaning process is performed once every 168 hours, which is equivalent to one week. When 168 hours have elapsed, it is the first period, and 168 hours is the first interval. The second steam cleaning process is performed once every 672 hours, which is equivalent to four weeks. When 672 hours have elapsed, it is the second period, and 672 hours is the second interval.

[0118] In step S101, the control unit 141 clears and then starts the first timer 145 and the second timer 146.

[0119] In step S102, it is determined whether the time measured by the second timer 146 has passed the second interval. If it has not passed the second interval ("no"), the process proceeds to step S110. If it has passed the second interval ("yes"), the process proceeds to step S103.

[0120] In step S110, it is determined whether the time measured by the first timer 145 has passed the first interval. If it has not passed the first interval ("no"), the process proceeds to step S102. If it has passed the first interval ("yes"), the process proceeds to step S111.

[0121] In step S111, if it is in the middle of washing ("yes"), after the washing is completed, the process proceeds to step S113. If it is not in the middle of washing ("no"), the process proceeds to step S113.

[0122] In step S113, the first steam cleaning process is performed. After resetting the first timer 145 and then starting it (S114), the process returns to step S102.

[0123] In step S102, if the time measured by the second counter 145 has passed the second interval ("yes"), the process proceeds to step S103. In step S103, if it is in the middle of washing ("yes"), after the washing is completed, the process proceeds to step S105. If it is not in the middle of washing ("no"), the process proceeds to step S105.

[0124] In step S105, the second steam cleaning process is performed. After resetting the first timer 145 and the second timer 146 and then starting them (S106), the process returns to step S102.

[0125] As described above, the first and second embodiments have been explained, but the present invention is not limited to these embodiments. For example, the following modified examples are also possible. In addition, the embodiments can be combined with the modified examples and the modified examples can be combined with each other.

[0126] In addition, examples not described in the embodiments and modified examples, and design changes within the scope that do not depart from the gist are also included in the present invention.

[0127] <Modified Example>

[0128] 1. Washing machine

[0129] In an embodiment, the rotation axis of the washing tub 15 is provided parallel to the horizontal direction, but it may also be inclined upwardly forward with respect to the horizontal direction. The inclination angle is in the range of 1 degree or more and 10 degrees or less.

[0130] In an embodiment, the washing machine has a drying function, but it may also not have a drying function.

[0131] In an embodiment, one LED is used as the notification device for performing the first display or the second display, but for example, two LEDs with different emission colors may be used and lit in cooperation with the corresponding steam cleaning. In addition, a device that emits a beeping sound, music, etc. may also be used as the notification device.

[0132] Although the calendar section is not particularly described, a wireless communication section may be provided instead of the clock function of the calendar section, and the current date, etc. may be obtained using WiFi, etc.

[0133] 2. Steam cleaning

[0134] (1) Number of times

[0135] In an embodiment, the steam cleaning includes the first steam cleaning and the second steam cleaning, but for example, it may also include the first steam cleaning, the second steam cleaning, and the third steam cleaning. In this case, the third temperature during the third steam cleaning may be set higher than the second temperature. When the third temperature is higher than the second temperature, the cycle (period) of the third steam cleaning may be set longer than the second cycle of the second steam cleaning, and when the third temperature is lower than the second temperature, the cycle (period) of the third steam cleaning may be set shorter than the second cycle of the second steam cleaning.

[0136] (2) Temperature

[0137] (2-1) First temperature

[0138] In an embodiment, the first temperature is constant at 50°C, but from the viewpoint of sterilizing mold, it is preferably 50°C or higher. The first temperature may also be appropriately determined within the range capable of killing mold according to the relationship with the first cycle, the first time, the rotation of the washing tub 15, etc.

[0139] In an embodiment, the first temperature is constant, but for example, the first temperature may be increased as time passes. Taking “2. Control of the washing machine 1 (3) Processing” in the first embodiment as an example, the first temperature of the first steam cleaning performed on May 3 may be set at 50°C, the first temperature of the first steam cleaning performed on the 10th may be set at 55°C, and the first temperature of the first steam cleaning performed on the 17th may be set at 60°C.

[0140] (2-2) Second temperature

[0141] In an embodiment, the second temperature is 60 °C. However, from the viewpoints of sterilizing molds, suppressing the generation of black molds, and preventing the formation of biofilms by bacteria or yeasts other than molds, a temperature of 60 °C or higher is preferred. However, considering safety, a temperature of 70 °C or lower is preferred.

[0142] The second temperature can also be appropriately determined within a range capable of suppressing the formation of biofilms according to its relationship with the second cycle, second time, rotation of the washing tank 15, etc.

[0143] (3) Time

[0144] (3-1) First time

[0145] In an embodiment, when the first temperature is 50 °C, the first time is 0 seconds. However, when the washing tank 15 does not rotate, the first time can also be 1200 seconds (20 minutes) or more. Thereby, molds can be effectively killed.

[0146] As a standard, when the washing tank rotates, when the first temperature is 50 °C or higher, the first time is 0 seconds or more, and when the first temperature is 45 °C, the first time is 3 minutes or more.

[0147] In addition, the first time can also be appropriately determined within a range capable of killing molds according to its relationship with the first temperature, first cycle, rotation of the washing tank 15, etc.

[0148] (3-2) Second time

[0149] In an embodiment, when the washing tank rotates and the second temperature is 60 °C, the second time is 10 minutes. However, when the washing tank 15 does not rotate, the second time can also be 30 minutes or more. Thereby, molds can be effectively killed. However, considering power consumption, it is preferred to rotate the washing tank 15 and keep the second temperature within the range of 60 °C or higher to shorten the second time.

[0150] In addition, the second time can also be appropriately determined within a range capable of suppressing the formation of biofilms according to its relationship with the second temperature, second cycle, rotation of the washing tank 15, etc.

[0151] (4) Cycle

[0152] (4-1) First cycle

[0153] In an embodiment, when the first temperature is 50°C, the first cycle is one week. However, for example, when the first temperature is within a range lower than 50°C and is a temperature capable of killing molds, the first cycle can also be set shorter than one week, such as 3 days. Conversely, when the first temperature is higher than 50°C, the first cycle can be set longer than one week, such as 10 days.

[0154] In addition, the first cycle can also be appropriately determined within the range capable of killing molds according to the relationship between the first temperature, the first time, the rotation of the washing tub 15, etc.

[0155] In an embodiment, the first cycle is constant, but for example, the period of the first cycle can also be shortened as time passes. Taking “2. Regarding the control (3) process of the washing machine 1” in the first embodiment as an example, it can also be configured such that the first steam cleaning after the second steam cleaning is performed 10 days after the second steam cleaning, the second cleaning is performed 7 days after the first steam cleaning for the first time, and the third cleaning is performed 4 days after the second steam cleaning for the first time.

[0156] (4-2) The second cycle

[0157] In an embodiment, when the second temperature is 60°C, the second cycle is four weeks. However, for example, when the second temperature is within a range lower than 60°C and is a temperature capable of inhibiting the formation of biofilms, the second cycle can also be set shorter than four weeks, such as three weeks. Conversely, when the second temperature is higher than 60°C, the second cycle can be set longer than four weeks, such as five weeks.

[0158] In addition, the second cycle can also be appropriately determined within the range capable of inhibiting the formation of biofilms according to the relationship between the second temperature, the second cycle, the rotation of the washing tub 15, etc.

[0159] (5) Rotation of the washing tub

[0160] In an embodiment, the rotation of the washing tub 15 is the same as that of the first steam cleaning and the second steam cleaning, but it can also be different. In addition, the rotation of the washing tub 15 during the first steam cleaning is constant, but for example, the rotation speed can be increased or decreased as time passes.

[0161] (6) Water supply

[0162] In an embodiment, the amount of water supplied in the first steam cleaning and the second steam cleaning is the same, but different amounts of water may also be used. In this case, since the second temperature of the second steam cleaning is higher than the first temperature and the second time is longer than the first time, the amount of water during the second steam cleaning may be more than that during the first steam cleaning. Thereby, the amount of water used during use can be optimized, and the amount of water used in steam cleaning can be reduced.

Claims

1. A washing machine, characterized in that, Comprising: A water tank; A washing trough rotatably supported within the water tank; A motor that rotationally drives the washing trough; A heater that heats the water within the water tank; A sensor that detects the temperature within the water tank or within the washing trough; And A control unit that controls the driving of the motor, The control unit is controlled to perform a first steam cleaning and a second steam cleaning automatically at regular intervals. The first steam cleaning generates water vapor through the heater to make the temperature within the washing trough reach a first temperature and maintain the state of reaching the first temperature for more than a first period of time. The second steam cleaning generates water vapor through the heater to make the temperature within the washing trough reach a second temperature higher than the first temperature and maintain the state of reaching the second temperature for more than a second period of time longer than the first period of time. The control unit performs the first steam cleaning in a first cycle and performs the second steam cleaning in a second cycle longer than the first cycle. When the periods of the first steam cleaning and the second steam cleaning overlap, only the second steam cleaning is implemented.

2. The washing machine according to claim 1, wherein The length of the second cycle is three times or more the first cycle.

3. The washing machine according to claim 1 or 2, wherein The control unit controls water supply and drainage, and in the first steam cleaning and the second steam cleaning, supplies a water volume within the range of 1.9 L or more and 2.3 L or less to the water tank.

4. The washing machine according to claim 1 or 2, wherein The control unit controls water supply and drainage, and in the first steam cleaning and the second steam cleaning, supplies a water volume such that the water level within the water tank is within the range of 5 mm or more and 15 mm or less relative to the upper surface of the heater.

5. The washing machine according to claim 1 or 2, wherein The rotation axis of the washing machine is horizontal or inclined within a range of within 10 degrees relative to the horizontal, The control unit controls water supply and drainage, and in the first steam cleaning and the second steam cleaning, supplies a water volume within the range where the washing trough does not immerse.

6. The washing machine according to claim 4, wherein The water level of the water tank is detected by a semiconductor type water level sensor.

7. The washing machine according to claim 1 or 2, wherein The control unit rotates the washing trough during the first steam cleaning and the second steam cleaning.

8. The washing machine according to claim 7, wherein The control unit rotates the washing trough within the range of 300 rpm or more and 500 rpm or less during the first steam cleaning and the second steam cleaning.

9. The washing machine according to claim 1 or 2, wherein The control unit causes a notification unit to notify of the operation when starting the cleaning operation during the first steam cleaning and the second steam cleaning.

10. The washing machine according to claim 9, wherein In the first steam cleaning and the second steam cleaning, the control unit causes the notification unit to notify in different notification manners.

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