WO2019230384A1

WO2019230384A1 - Washing machine

Info

Publication number: WO2019230384A1
Application number: PCT/JP2019/019201
Authority: WO
Inventors: 池水　麦平; 脇田　克也
Original assignee: パナソニックＩｐマネジメント株式会社
Priority date: 2018-05-29
Filing date: 2019-05-15
Publication date: 2019-12-05
Also published as: JPWO2019230384A1; TW202003957A

Abstract

A washing machine according to the present invention is provided with: a washing tub that is rotatably provided in a water tank; a water supply unit that supplies water into the water tank; a heating unit that heats the water stored in the water tank; a water level detection unit that detects the level of the water stored in the water tank; and a control unit that carries out a washing operation and a tank washing operation including a tank sterilization step in which the water stored in the water tank is heated by the heating unit, and the inside of the water tank is sterilized by means of steam generated through the heating. The control unit performs control, in the tank sterilization step, so as to set the first water level of the water stored in the water tank to be lower than the lowest water level set for the washing operation, and to be higher than a water level at which the lower end of the washing tub is in contact with the water surface.

Description

Washing machine

The present invention relates to a washing machine for washing clothes and the like.

Generally, in a washing machine, detergent residue or dirt accumulates on the inner surface of the water tub or the outer surface of the washing tub during long-term use. Fungi or molds propagate using detergent waste or dirt as a nutrient source or habitat. As a result, an unpleasant odor may be generated in the washing machine or from the clothes after washing, or a part of the above-mentioned dirt may adhere to the washed clothes.

Also, in order to improve the cleaning performance, there is a washing machine having a shower function that is a function of discharging washing water to the laundry in the washing tub. Some of these washing machines are provided with a circulation water channel for circulating the washing water in the water tub and discharging it into the washing tub. However, since the circulation channel is difficult to care for, dirt substances accumulate in the circulation channel, and fungi or molds tend to propagate using the deposit as a habitat. For this reason, clothing has been washed even though washing has occurred due to unpleasant odors in the circulation channel, bacteria or mold on the laundry, or metabolites or biofilms attached to it. May get dirty.

In order to solve the above-mentioned dirt, a washing machine for sterilizing the washing tub in the following procedure has been proposed (for example, see Patent Document 1). That is, after performing a tank cleaning process using a dedicated washing detergent for washing the washing tub, the air heated by the heating means is sent into the washing tub by the blowing means and the inside of the washing tub is heated to a high temperature. To. Further, a small amount of water is supplied to the heating means or the washing tub to make the washing tub a hot and humid environment, and the sterilization in the washing tub is performed.

Japanese Patent Laid-Open No. 2005-253584

However, in the above-described conventional configuration, members such as a water tub and a washing tub inside the washing machine, and water stored in the water tub are heated through the heated air. In addition, when heating a small amount of water supplied to the heating means or the tank, the member inside the washing machine is heated via the air. In these heating, since the thermal conductivity of air is lower than that of water or other substances, there is a problem that it takes time to raise the temperature in the entire water tank.

That is, when the water tub and the washing tub are heated via air, there is a problem that the temperature of the water tub and the washing tub is difficult to rise because of a large heat capacity. In particular, the washing tub provided in the water tub has a large heat capacity. Therefore, most of the heat generated by the heating means is used to increase the water temperature, and the water temperature rises faster than the temperature of the water tub and the washing tub. However, since various seal members and the like provided in the water tub and the washing tub have an upper limit on the usable temperature under heat resistant conditions, it is necessary to prevent an excessive increase in the water temperature. In addition, as the temperature of the water stored in the water tank increases, heat release from the washing machine to the outside of the washing machine increases through piping such as a drainage path or a circulation path connected to the bottom of the water tank. .

This invention solves the said conventional problem, and aims at providing the washing machine which can raise the temperature in a water tank rapidly and can perform sterilization in a water tank efficiently.

In order to solve the above-described conventional problems, a washing machine of the present invention heats water stored in a water tub, a water tub that supplies water in the water tub, a water tub that is rotatably provided in the water tub. Heating section, water level detection section for detecting the water level stored in the water tank, washing operation, and heating the water stored in the water tank to the heating section, and the steam generated by heating in the water tank And a control unit that executes a tank cleaning operation including a tank sterilization step for sterilization. In the tank sterilization step, the control unit lowers the first water level stored in the water tank lower than the lowest water level set in the washing operation and higher than the water level at which the lower end of the washing tank is in contact with the water surface. To control.

This allows heat to be transferred directly from the heated water to the washing tub, so that the washing tub can be efficiently heated. In particular, since the washing tub is a component having the largest mass and heat capacity among the members in the water tub of the washing machine, the temperature in the water tub can be quickly raised by efficiently heating the washing tub. Therefore, sterilization in the water tank can be performed efficiently. Further, in the tank sterilization step, the first water level of the water stored in the water tank is lower than the lowest water level set in the normal washing operation and higher than the water level at which the lower end of the washing tank is in contact with the water surface. The time and energy required for heating water can be reduced.

The washing machine of the present invention can efficiently disinfect the water tank.

1 is a schematic configuration diagram of a washing machine according to Embodiment 1 of the present invention. Block configuration diagram of the washing machine in Embodiment 1 of the present invention The time chart which shows operation | movement of the washing machine in Embodiment 1 of this invention The graph which shows the relationship between the water temperature and sanitization effect in Embodiment 1 of this invention The schematic block diagram of the principal part which shows the water level at the time of the tank washing | cleaning driving | operation of the washing machine in Embodiment 1 of this invention The schematic diagram which shows the water level and water flow at the time of the rinse step of the washing machine in Embodiment 1 of this invention. Schematic configuration diagram of a washing machine in Embodiment 2 of the present invention

The washing machine of the first invention includes a washing tub rotatably provided in the water tub, a water supply unit for supplying water into the water tub, a heating unit for heating water stored in the water tub, and a water tub. A water level detection unit that detects the water level of the stored water, a washing operation, and a tank sterilization step that causes the heating unit to heat the water stored in the water tank and disinfects the water tank with steam generated by heating. And a controller that executes a tank cleaning operation. In the sterilization step, the control unit is configured such that the first water level stored in the water tank is lower than the lowest water level set in the washing operation and higher than the water level at which the lower end of the washing tank is in contact with the water surface. To control.

Thus, by setting the first water level of the water stored in the water tub higher than the water level at which the lower end of the washing tub is in contact with the water surface, the water heated by the heating unit and the washing tub can be brought into contact with each other. Therefore, the heat of a heating part can be efficiently transmitted to a washing tub via heated water, and the temperature in a water tub can be raised rapidly. In particular, since the washing tub disposed in the water tub has a large mass and heat capacity, the temperature in the water tub can be quickly increased by efficiently heating the washing tub. As a result, the inside of the water tank can be sterilized efficiently. In addition, the first water level of the water stored in the water tank is lower than the lowest water level set in the normal washing operation and higher than the water level at which the lower end of the washing tank is in contact with the water surface, thereby heating the water. Time and energy can be reduced.

According to a second aspect of the invention, in particular, in the first aspect of the invention, the washing tub is driven to rotate about the horizontal axis, and the controller performs washing during the temperature rise of the water in the tub by the heating unit in the tank sterilization step. The tank is controlled to rotate.

This makes it possible to immerse the peripheral side surface of the washing tub in water one after another and efficiently heat the washing tub. Further, since the warm water stored in the water tub is agitated by the rotation of the washing tub, the evaporation of the warm water or the heat exchange between the warm water and the air is promoted. As a result, the temperature and humidity in the water tank can be efficiently increased, and the inside of the water tank can be effectively sterilized.

In a third aspect of the invention, in particular, in the second aspect of the invention, the washing tub is disposed at an inclination, the control unit further executes a rinsing step for washing the inside of the water tub in the tub washing operation, and the control unit is rinsed. In the step, the second water level of the water stored in the water tub is controlled so that the lower end of the washing tub is submerged, and the laundry tub is driven to rotate at a higher speed than in the sterilization step. To do.

In this way, in addition to being able to efficiently sterilize the water tank in the tank sanitization step, in the rinsing step, the washing tank is rotated at a high speed at the second water level to wash a wide area in the water tank. Is possible. In particular, when the washing tub is inclined, for example, when it is inclined so that the front side is higher, the laundry tub is rotated while the lower end of the front higher side of the washing tub is immersed in water. The entire peripheral side surface of the tank can be brought into contact with water. As a result, the cleaning effect in the water tank can be enhanced.

According to a fourth aspect of the invention, in particular, in any one of the first to third aspects of the invention, the tank and the washing tub are cleaned in the tank cleaning operation, and the control unit performs the tank sterilization step in the tank cleaning operation. A rinsing step for cleaning the inside of the water tank is performed later.

This makes it possible to increase the temperature and humidity in the aquarium by the steam generated in the aquarium, and to kill fungi or molds that inhabit the surface of the aquarium and the washing tub by the moist heat above a certain temperature. The bacteria, mold, biofilm, etc. killed in the tank sterilization step can be washed out and discharged out of the machine in the rinsing step executed after the tank sterilization step. As a result, it is possible to suppress the adhesion of bacteria, mold, biofilm, and the like from the water tub or the washing tub during the next washing operation, thereby suppressing the adhesion to the object to be cleaned and finishing the laundry cleanly.

According to a fifth aspect of the invention, in particular, in the fourth aspect of the invention, the washing machine circulates the water in the water tank through the circulation water path provided to guide the water in the water tank from the bottom of the water tank into the washing tank. In the tank cleaning operation, the control unit controls the pump to drive and circulate the water in the water tank through the circulation water channel.

This allows heated water to flow through the circulation channel and kill bacteria or molds that inhabit the circulation channel. And dirt, such as dead bacteria, mold, and biofilm, can be peeled off from the circulation channel and discharged out of the machine. Therefore, it is possible to clean the surface of the pipe around the water where the humidity is high and the habitat for fungi or mold, and to suppress the adhesion of dirt to the object to be cleaned during the washing operation.

In the sixth invention, in particular, in the third invention, the second water level is higher than the first water level.

This allows the cleaning range in the rinsing step to be wider than the sterilizing range in the tank sterilization step. As a result, the cleaning effect in the water tank can be enhanced.

(Embodiment 1)
FIG. 1 is a schematic configuration diagram of a washing machine according to the first embodiment of the present invention. FIG. 2 is a block diagram of the washing machine in the present embodiment. FIG. 3 is a time chart showing the operation at the time of the tank washing operation of the washing machine in the present embodiment. FIG. 4 is a graph showing the relationship between the water temperature and the sterilization effect in the present embodiment. FIG. 5 is a schematic configuration diagram of the main part showing the water level during the washing operation of the washing machine in the present embodiment. FIG. 6 is a schematic diagram showing a water level and a water flow during the rinsing step of the washing machine according to the present embodiment.

1 to 6, the washing machine of the present embodiment is a so-called drum type washing machine in which the rotation shaft 3a of the drum 3 serving as a washing tub is set in the horizontal direction (including inclination). A water tank 2 elastically supported in the housing 1 is provided. In the water tub 2, a bottomed cylindrical drum 3 as a washing tub is provided so as to be rotatable about a horizontal rotation shaft 3a. In the present embodiment, the rotation shaft 3a of the drum 3 has an angle θ (for example, 10 degrees), and the drum 3 is disposed so as to incline toward the front higher side with the front rising.

A plurality of baffles 4 projecting inward toward the rotation center of the drum 3 and a large number of small holes 5 communicating with the inside of the water tank 2 are provided on the inner peripheral side surface of the drum 3. An opening 6 is provided on the front side of the drum 3. The user uses the opening 6 to put laundry such as clothes (hereinafter referred to as an object to be cleaned) into and out of the drum 3. A motor 7 that rotationally drives the drum 3 is disposed on the rear surface of the water tank 2. The motor 7 is composed of a brushless DC motor, and the rotation speed can be freely changed by inverter control.

A water supply pipe 8 for supplying water into the water tank 2 is connected to a tap (not shown) of a water supply, and is provided with a water supply valve 9 which is a water supply section. The detergent case 10 into which the detergent is introduced is connected to the water supply pipe 8 in communication. The detergent case 10 is connected to the water tank 2 through the water supply path 11. Thereby, the water flowing from the water supply pipe 8 through the detergent case 10 and the water supply path 11 flows into the water tank 2.

The washing water in the water tank 2 is discharged out of the machine through the drainage path 12. The drainage path 12 includes a drainage valve 13 that is a drainage part and a drainage filter 14. Washing water is discharged from the drainage port 15 provided at the bottom of the aquarium 2 through the drainage filter 14 and through the opened drainage valve 13 to the outside of the machine. The drainage filter 14 is provided at a position where the washing water circulates during the washing operation, and collects a button or the like detached from the object to be cleaned. The drainage filter 14 is configured to be removable from the front side of the housing 1.

The circulating water channel 16 is provided so as to guide the washing water in the water tank 2 from the drain port 15 to the opening 6 side located at the front part in the water tank 2. The circulation channel 16 is provided with a pump 17 and a discharge port 18 for circulating the wash water. The pump 17 is installed at the bottom of the housing 1 and is disposed downstream of the drainage filter 14. The discharge port 18 discharges wash water into the drum 3 by driving the pump 17.

The heater 19 is a heating unit that heats the water stored in the water tank 2. The heater 19 is disposed at the bottom of the water tank 2 and is submerged when a predetermined amount of water is stored in the water tank 2. The water level detection unit 20 detects the water level of the washing water supplied into the water tank 2. The temperature detection unit 21 detects the temperature of the water in the water tank 2. The temperature detection unit 21 is composed of a thermistor or the like, and is disposed in a submerged portion at the lower part of the water tank 2.

The control unit 22 is provided in the housing 1 and controls various components based on input information to execute a washing operation, a tank washing operation, and the like. Specifically, as shown in the block configuration diagram of FIG. 2, the control unit 22 includes an amount of an object to be cleaned detected by the cloth amount detection unit 23, a washing water level detected by the water level detection unit 20, and The temperature of water detected by the temperature detector 21 and the driving amount (for example, the number of rotations) of the drum 3 detected by the rotation detector 24 are input as information. Based on these inputs, the control unit 22 controls the motor 7, the water supply valve 9, the drain valve 13, the pump 17, the heater 19, etc., and sequentially controls the washing step, the rinsing step, the dehydration step, etc. Execute.

Moreover, the control part 22 performs the tank cleaning operation which cleans the water tank 2 and the drum 3 so that it may mention later. The tank cleaning operation includes at least a tank sterilization step and a rinsing step. In the tank sterilization step, the water stored in the water tank 2 is heated by the heater 19 and the water tank 2 is sterilized with the generated steam. The rinsing step is performed after the tank sterilization step, and the water tank 2, the drum 3, the circulating water channel 16 and the like are washed.

The user can open and close the object to be cleaned from the opening 6 provided on the front surface side of the drum 3 by opening the door 25 that can be opened and closed provided on the front surface of the housing 1. In addition, an operation display unit 26 is provided in the upper part on the front side of the housing 1. The user can make settings for operating the washing machine by operating the operation display unit 26. The operation display unit 26 displays the setting contents, the operation status, and the like.

The operation and action of the washing machine configured as described above will be described below.

First, I will explain the laundry operation. The washing operation includes at least a washing step, a rinsing step, and a dewatering step.

The user opens the door 25 and puts an object to be cleaned into the drum 3 through the opening 6. Then, the user turns on the power switch (not shown) of the operation display unit 26 and operates the start switch (not shown) to start operation.

First, a washing step is executed. When the operation starts, the control unit 22 detects the amount of the object to be cleaned put into the drum 3 by the cloth amount detection unit 23. The amount of the object to be cleaned can be detected from the amount of torque applied to the motor 7 or the current value of the motor 7 when the drum 3 rotates. The control unit 22 sets the amount of water to be supplied into the water tank 2 according to the detected amount of the object to be cleaned. Moreover, the control part 22 sets the time which performs each step of washing operation. Further, the control unit 22 determines a standard detergent amount from a preset detergent amount according to the amount of the object to be cleaned, and displays it on the operation display unit 26. The user puts the detergent into the detergent case 10 according to the displayed detergent amount.

Next, the control unit 22 opens the water supply valve 9. As a result, water from the water supply is supplied into the water tank 2 via the detergent case 10. The water that has entered the detergent case 10 through the water supply pipe 8 dissolves the detergent put in the detergent case 10 and is supplied into the water tank 2 as washing water. At this time, since the drain valve 13 is closed, the washing water accumulates at the bottom of the water tank 2. Washing water collected at the bottom of the water tank 2 flows into the drum 3 through the small holes 5.

Next, the control unit 22 detects the amount of water supplied into the water tank 2 by the water level detection unit 20. When the controller 22 determines that the amount of water supplied has reached a predetermined amount of water set according to the amount of the object to be cleaned, the controller 22 closes the water supply valve 9. Note that the control unit 22 rotationally drives the drum 3 in one direction at a rotation speed (for example, 20 rpm) at which the object to be cleaned rolls in the drum 3 during water supply. This accelerates the penetration of the wash water into the object to be cleaned. In addition, the water level of the washing water in the water tank 2 is lowered from the set water level due to the water absorption of the washing water to be washed. Then, the control part 22 opens the water supply valve 9 again, replenishes in the washing tub 2, and returns the water level of washing water to a setting water level.

Next, the control unit 22 drives the pump 17 when the water supply is finished. As a result, the water accumulated at the bottom of the water tank 2 is guided from the drain port 15 to the circulation channel 16. The water flowing into the circulation water channel 16 flows through the circulation water channel 16 and is discharged from the discharge port 18 into the drum 3. As a result, the washing water that has permeated the article to be cleaned flows out from the small hole 5 into the water tank 2 and circulates along the route passing from the drain port 15 through the circulation channel 16.

Next, the control unit 22 drives the drum 3 to rotate in the forward and reverse directions alternately at a predetermined number of rotations (for example, 42 rpm) by the motor 7 every predetermined time, and executes washing of the object to be cleaned. In the tapping cleaning, the object to be cleaned is lifted in the rotating direction of the drum 3 by the baffle 4 and then dropped from the upper part in the drum 3 for cleaning. The control unit 22 executes the washing step for a predetermined time (for example, 10 minutes). Thereafter, the control unit 22 opens the drain valve 13 to discharge the washing water to the outside of the machine, and ends the washing step. After the washing step, the control unit 22 executes the rinsing step and the dehydrating step in this order, and finishes the washing operation. Detailed descriptions of the rinsing step and the dehydrating step are omitted.

In addition, the above-mentioned washing water is a general term for water used in a washing machine. That is, the washing water includes water that does not include the detergent supplied to the washing machine, washing water that includes the detergent that has been added, and rinse water that rinses away detergent components and dirt in the rinsing step.

Next, the tank cleaning operation will be described. The tank washing operation is performed separately from the washing operation, and the water tank 2, the drum 3, the circulating water channel 16 and the like are washed. The tank cleaning operation includes at least a tank sterilization step, a drainage step, a rinse step, and a drainage step, and these steps are executed in order.

The user turns on the power switch (not shown) of the operation display unit 26, sets the tank cleaning operation, and then operates the start switch (not shown) to start the operation. First, a tank sterilization step is performed.

Control part 22 will open the water supply valve 9, as shown in the time chart of FIG. 3, if a tank sanitization step is started. Thereby, water from the water supply is supplied into the water tank 2 through the water supply pipe 8 and the detergent case 10. At this time, since the detergent is not put into the detergent case 10, water not containing the detergent is supplied into the water tank 2. Water accumulated at the bottom of the water tank 2 flows into the drum 3 through the small holes 5.

Next, the control unit 22 detects the amount of water supplied into the water tank 2 with the water level detection unit 20. Based on the output of the water level detection unit 20, the control unit 22 supplies water to a predetermined water level L1 and closes the water supply valve 9. The water level L1 is set to a water level that is higher than the water level at which the lower end 3b on the rear side of the drum 3 is in contact with the water surface (see FIG. 5) and lower than the lowest water level that is supplied in a normal washing operation. The water level L1 is a water level at which the heater 19 is submerged.

Next, after supplying water, the control unit 22 controls energization to the heater 19 based on the output of the temperature detection unit 21 and heats the water stored at the bottom of the water tank 2. As a result, steam is generated in the water tank 2. At this time, since the heated water and the lower part of the drum 3 are in contact with each other, the drum 3 is directly heated with warm water. Accordingly, the drum 3 having a large mass and heat capacity can be efficiently heated, and the temperature in the water tank 2 can be quickly raised.

Then, the control unit 22 drives the drum 3 to rotate at a low speed (for example, 20 rpm) almost simultaneously with the energization of the heater 19 or before and after. Thereby, the peripheral side surface of the drum 3 can be heated entirely with warm water. In addition, heated water can be agitated to promote the generation of steam. That is, the drum 3 is rotationally driven during the temperature rise by heating the water in the water tank 2, and the water tank 2 can be quickly heated from the low temperature stage.

Thus, the inside of the water tank 2 can be sterilized by heating the inside of the water tank 2. It is desirable to raise the temperature in the water tank 2 for sterilization to 50 degrees or more and 90 degrees or less. In general, mold or fungus sterilization is more advantageous at higher temperatures. However, if the temperature is set to a predetermined temperature or higher, it is necessary to consider the heat resistant temperature of the resin material that is the structure of the washing machine. In addition, it takes time to heat the supplied water to a high temperature. Therefore, in order to realize the same sterilization effect even at a low temperature for a short time and at a low temperature, as described above, the temperature in the water tank 2 is desirably raised to 50 degrees or more and 90 degrees or less.

FIG. 4 shows the relationship between the heating temperature and holding time for mold (horizontal axis) and the sterilization effect (vertical axis). The relationship of the heating temperature is temperature a <temperature b <temperature c in FIG. For example, temperature a = 45 degrees, temperature b = 48 degrees, and temperature c = 50 degrees.

¡The lower the heating temperature, the longer it takes to kill mold or fungi. In order to reduce the number of molds or fungi that inhabit in a shorter time, it is confirmed that higher heating temperature is more advantageous.

For example, the time required to reduce the number of bacteria from 1.0E + 07 to 1.0E + 05 is compared. The temperature a is over 10 minutes, while the temperature c is shortened to less than 5 minutes. In addition, the number of bacteria that decrease with the same retention time is compared. During the retention time of 0 to 5 minutes, the number of bacteria decreases from 1.0E + 07 to about 1.0E + 06 at temperature a, whereas the number of bacteria decreases from 1.0E + 07 to less than 1.0E + 02 at temperature c. Therefore, in the present embodiment, the heating temperature for mold is 50 degrees.

The control unit 22 detects the water temperature of the washing water in the water tank 2 by the temperature detection unit 21. When the controller 22 detects that the water temperature has reached the set temperature T1, the controller 22 controls the heater 19 to maintain the temperature near the set temperature T1 for a predetermined time. For example, when the set temperature T1 is 55 degrees, the control unit 22 turns off the heater 19 when the water temperature reaches 55 degrees. Further, the controller 22 turns on the heater 19 when the water temperature drops to 53 degrees. As described above, the temperature in the water tank 2 can be maintained at 50 degrees or more by turning the heater 19 on or off. Note that the controller 22 continues to rotate the drum 3 until the tank sterilization step is completed even after the water temperature reaches the set temperature T1.

Further, the controller 22 drives the pump 17 when the water temperature reaches the set temperature T1. Thereby, the heated water in the water tank 2 flows and circulates in the circulation water channel 16 as follows. The heated water in the water tank 2 is sucked from a drain port 15 provided at the bottom of the water tank 2, passes through a drain filter 14, and is guided to a circulation channel 16. The water flowing into the circulation water channel 16 is discharged from the discharge port 18 into the drum 3. Then, the water discharged into the drum 3 flows out from the small hole 5 into the water tank 2 and circulates along a route passing through the circulation water channel 16 from the drain port 15.

As described above, the heated water flows and circulates through the path passing through the circulation channel 16, so that the bacteria or mold that inhabit the path passing through the circulation channel 16 can be killed and sterilized. At this time, it is preferable that the control unit 22 drives the pump 17 at a low speed so that bacteria and fungi are brought into contact with the heated water for a long time. Specifically, the heated water may be circulated at a speed that allows the heated water to flow without staying in the route passing through the circulating water channel 16. The drive of the pump 17 may be continuous or intermittent.

The control unit 22 executes the above-described tank sterilization step for a predetermined time (for example, 10 minutes after the water temperature reaches the set temperature T1), and stops energization of the heater 19.

Next, the control unit 22 executes a tank sterilization step followed by a drainage step. In the drainage step, the heated water used in the tank sterilization step is drained. For this purpose, the control unit 22 opens the drain valve 13. As a result, the heated water is drained from the drain port 15 through the drain path 12 to the outside of the apparatus.

Next, the control unit 22 executes a rinsing step following the tank sterilization step and the drainage step. In the rinsing step, dirt such as bacteria, mold, biofilm, etc. killed in the tank sterilization step is peeled off from the wall surface of the water tank 2 or the drum 3 and washed away. Hereinafter, the details of the rinsing step will be described.

First, the control unit 22 opens the water supply valve 9 and supplies water into the water tank 2 up to a predetermined water level L2 based on the output of the water level detection unit 20. This is shown in the schematic block diagram of FIG. The predetermined water level L2 is higher than the predetermined water level L1 at the time of the tank sterilization step. For example, in the drum 3 inclined so that the front side (left side in FIG. 5) becomes higher, the water level L2 is set to a water level at which the lower end 3c on the higher side is submerged.

The control unit 22 detects the amount of water supplied into the water tank 2 with the water level detection unit 20. Based on the output of the water level detection unit 20, the control unit 22 supplies water to a predetermined water level L2 and closes the water supply valve 9. When water is stored in the water tank 2 up to the predetermined water level L2, the lower part of the drum 3 is sufficiently immersed in the water. The water level detection unit 20 may detect the water levels L1 and L2 by detecting the amount of water supplied into the water tank 2.

When the water is accumulated up to the predetermined water level L2, the control unit 22 drives the drum 3 to rotate at a higher speed (for example, 100 rpm) than in the tank sterilization step. Thereby, the water in the water tank 2 is wound upward by the high speed rotation of the drum 3 and reaches the upper surface of the water tank 2. As shown in FIG. 6, in the drum 3 whose front side (left side in FIG. 6) is inclined upward, the lower end 3c on the higher side is immersed in water, so that the entire drum 3 can be cleaned.

As described above, the control unit 22 executes the rinsing step after the tank sterilization step. Thereby, dirt, such as bacteria, mold, biofilm, etc. killed in the tank sterilization step can be peeled off from the wall surface of the water tank 2 or the drum 3 and washed away.

At this time, when the water level detection unit 20 detects the predetermined water level L2, the control unit 22 closes the water supply valve 9 and drives the pump 17. Thereby, the water in the water tank 2 flows and circulates in the circulation channel 16, and dirt such as bacteria, molds, biofilms, etc. killed in the sterilization step can be peeled off from the wall surface in the circulation channel 16. The control unit 22 executes the above rinsing step for a predetermined time (for example, 30 minutes) set in advance, and stops the rotation driving of the drum 3.

Finally, the control unit 22 executes a draining step following the rinsing step. In the draining step, the water in the water tank 2 and the circulation channel 16 is drained outside the apparatus. The water in the water tank 2 and the circulating water channel 16 contains dirt such as bacteria, molds, biofilms, etc., killed in the tank disinfection step.

The control unit 22 opens the drain valve 13 to drain the water in the water tank 2 and the circulation water channel 16. Thereafter, the drum 3 is rotated at a high speed (for example, 300 rpm) for a short time. As a result, water droplets and the like adhering to the drum 3 are discharged outside the apparatus, and the control unit 22 ends the draining step and completes the tank cleaning operation.

As described above, the washing machine according to the present embodiment has a drum 3 rotatably provided in the water tank 2, a water supply valve 9 for supplying water into the water tank 2, and water stored in the water tank 2. The heater 19 for heating, the water level detecting unit 20 for detecting the water level stored in the water tank 2, the washing operation, and the water stored in the water tank are heated by the heating unit, and steam generated by heating is used. And a control unit 22 that executes a tank cleaning operation including a tank sterilization step for sterilizing the inside of the water tank. In the tank sterilization step, the control unit 22 sets the first water level L1 of the water stored in the water tank 2 to be lower than the minimum water level set in the washing operation, and from the water level at which the lower end 3b of the drum 3 is in contact with the water surface. Control to be higher. When the drum 3 is inclined, the first water level L1 is higher than the water level at which the lower end of the drum 3 is in contact with the water surface.

Thus, the water heated by the heater 19 and the drum 3 come into contact with each other, so that the heat of the heater 19 can be efficiently transmitted to the drum 3. And the temperature in the water tank 2 can be quickly raised by the heat radiation of the drum 3. As a result, the inside of the water tank 2 can be sterilized efficiently. In particular, since the drum 3 disposed in the water tank 2 has a large mass and heat capacity, the temperature in the water tank 2 can be rapidly increased by efficiently heating the drum 3. Further, in the tank sterilization step, the water level stored in the water tank 2 is lower than the lowest water level set in the normal washing operation and higher than the water level at which the lower end 3b of the drum 3 is in contact with the water surface, The time and energy required for heating the water can be reduced.

The drum 3 is rotationally driven around the horizontal axis, and the control unit 22 controls the drum 3 to be rotationally driven during the temperature rise of the water in the water tank 2 in the tank sterilization step.

Thus, the peripheral side surface of the drum 3 can be sequentially immersed in water, and the drum 3 can be heated efficiently. Moreover, since warm water can be stirred by rotation of the drum 3, evaporation of warm water or heat exchange between warm water and air is promoted. As a result, the temperature and humidity in the water tank 2 can be increased efficiently, and the inside of the water tank 2 can be effectively sterilized.

Further, the drum 3 is disposed at an inclination, and the control unit 22 further executes a rinsing step for cleaning the inside of the water tank 2 in the tank cleaning operation. In the rinsing step, water is supplied to the second water level L2 where the lower end 3c on the higher side of the drum 3 is submerged, and the drum 3 is driven to rotate at a higher speed than in the tank sterilization step.

Thereby, in the tank sterilization step, the inside of the water tank 2 can be sterilized efficiently. In the rinsing step, a wide range in the water tank 2 can be washed by rotating at a high water level and high speed. As a result, the cleaning effect in the water tank 2 can be enhanced. In particular, when the drum 3 is inclined, for example, when it is inclined so that the front side is higher, the drum 3 rotates while the lower end 3c on the front higher side of the drum 3 is immersed in water. The entire peripheral side surface of the drum 3 can be brought into contact with water.

Further, in the tank cleaning operation, the water tank 2 and the drum 3 are cleaned, and the control unit 22 executes a rinsing step after the tank sterilization step in the tank cleaning operation.

This allows bacteria, mold, biofilm, etc. killed in the tank sterilization step to be washed away in the rinse step and discharged out of the machine. As a result, it is possible to suppress the adhesion of bacteria, mold, biofilm, and the like from the water tank 2 or the drum 3 during the next washing operation, thereby suppressing adhesion to the object to be cleaned, and finishing the laundry cleanly.

The washing machine has a circulation channel 16 provided to guide the water in the aquarium 2 from the bottom of the aquarium 2 into the drum 3, and a pump 17 for circulating the water in the aquarium 2 through the circulation channel 16. In the tank cleaning operation, the control unit 22 controls the pump 17 to drive and circulate the water in the water tank 2 through the circulation water channel 16.

By flowing heated water through the circulation channel 16, the bacteria or mold that inhabit the circulation channel 16 are killed, and the dead bacteria, mold, biofilm, etc. are removed from the circulation channel 16. It can be discharged out of the machine. Therefore, it is possible to clean the surface of the pipe around the water where the humidity is high and the habitat for fungi or mold, and to suppress the adhesion of dirt to the object to be cleaned during the washing operation.

Further, the second water level L2 of the rinsing step is higher than the first water level L1 of the tank sterilization step.

This allows the cleaning range in the rinsing step to be wider than the sterilizing range in the tank sterilization step. As a result, the cleaning effect in the water tank 2 can be enhanced.

(Embodiment 2)
FIG. 7 is a schematic configuration diagram of a washing machine according to the second embodiment of the present invention. A feature of the present embodiment is that a part of the washing machine according to the first embodiment is applied to a so-called vertical washing machine in which the rotation axis of the washing tub 3 is set in the vertical direction (vertical direction in FIG. 7). It is. In the configuration according to the present embodiment, the same components as those of the first embodiment are denoted by the same reference numerals, and the detailed description of the first embodiment is used.

In FIG. 7, a washing tub 3 is rotatably provided in the water tub 2. A stirring blade 27 is rotatably provided at the bottom of the washing tub 3. The stirring blade 27 is rotationally driven by the motor 7 and stirs the washing water stored in the water tank 2.

Also in the vertical washing machine of the present embodiment, similarly to the first embodiment, the control unit 22 controls the tank cleaning operation for cleaning the water tank 2, the washing tank 3, and the like. The tank cleaning operation is performed separately from the washing operation, and includes at least a tank sterilization step, a drainage step, a rinse step, and a drainage step, and these steps are executed in order.

In the tank sterilization step, the control unit 22 detects the amount of water supplied into the water tank 2 by the water level detection unit 20. Based on the output of the water level detection unit 20, the control unit 22 supplies water to the predetermined water level L <b> 1 in the water tank 2 and closes the water supply valve 9. The predetermined water level L1 is set to a water level that is higher than the water level at which the lower end of the washing tub 3 is in contact with the water surface and lower than the lowest water level that is supplied in a normal washing operation.

Control part 22 controls energization to heater 19 based on the output of temperature detection part 21 after water supply, and heats the water stored in the bottom of water tank 2. As a result, steam is generated in the water tank 2. At this time, since the heated water and the lower part of the washing tub 3 are in contact, the washing tub 3 is directly heated with warm water. Therefore, the washing tub 3 having a large mass and heat capacity can be efficiently heated, and the temperature in the water tub 2 can be quickly raised.

Then, the control unit 22 rotationally drives the stirring blade 27 almost simultaneously with the energization of the heater 19 or before and after. By this rotational drive, the washing water stored in the water tank 2 is agitated. Thereby, the surrounding side surface of the washing tub 3 can be heated entirely with warm water. In addition, heated water can be agitated to promote the generation of steam. That is, the water tank 2 can be quickly heated from the low temperature stage during the temperature increase by heating the water in the water tank 2. Thus, the inside of the water tank 2 can be sterilized by heating the inside of the water tank 2.

And the control part 22 detects the water temperature of the wash water in the water tank 2 by the temperature detection part 21. FIG. When the controller 22 detects that the water temperature has reached the set temperature T1, the control unit 22 controls the heater 19 to be turned on or off, and maintains the temperature near the set temperature T1 for a predetermined time. In this way, the inside of the water tank 2 is heated to kill the fungi and molds that inhabit the wall surfaces of the water tank 2 and the washing tank 3.

The control unit 22 executes the tank sterilization step described above for a predetermined time (for example, 10 minutes after reaching the set temperature T1), and stops energization of the heater 19.

Next, the control unit 22 executes a tank sterilization step followed by a drainage step. In the drainage step, the heated water used in the tank sterilization step is drained. For this purpose, the control unit 22 opens the drain valve 13. As a result, the heated water is drained from the drainage port (not shown) through the drainage path 12 to the outside of the apparatus.

Next, the control unit 22 executes a rinsing step following the tank sterilization step and the drainage step. In the rinsing step, dirt such as bacteria, molds, biofilms, etc. killed in the tank sterilization step are peeled off from the wall surface of the water tub 2 or the washing tub 3 and washed away.

First, the control unit 22 opens the water supply valve 9, supplies water into the water tank 2 to the predetermined water level L2 based on the output of the water level detection unit 20, and closes the water supply valve 9. And the control part 22 rotationally drives the stirring blade 27 at high speed. By this rotational drive, a water flow is generated in the water tank 2. And the circumference | surroundings of a water surface rise in V shape, and wash away dirt, such as a microbe, mold | fungi, biofilm, etc. which were killed at the tank sanitization step. At this time, the water level L2 of the water stored in the water tank 2 is preferably higher than the water level L1 of the water stored in the water tank 2 in the tank sterilization step.

Finally, the control unit 22 executes a draining step following the rinsing step and ends the tank cleaning operation. In the draining step, the water in the water tank 2 is drained outside the apparatus. The water in the water tank 2 includes dirt such as bacteria, molds, biofilms, etc. that have been killed in the tank disinfection step. The control unit 22 opens the drain valve 13 to drain the water in the water tank 2. The stirring blade 27 may be driven to rotate integrally with the washing tub 3.

As described above, the washing machine of the present embodiment includes the washing tub 3 that is rotatably provided in the water tub 2, the water supply valve 9 that supplies water to the water tub 2, and the water stored in the water tub 2. The heater 19 for heating the water, the water level detection unit 20 for detecting the water level stored in the water tank 2, the washing operation, and the water generated in the water tank are heated by the heating unit, and steam generated by heating And a control unit 22 that executes a tank cleaning operation including a tank sterilization step for sterilizing the inside of the water tank. In the tank sterilization step, the control unit 22 sets the first water level L1 of water stored in the water tank 2 to be lower than the lowest water level set in the washing operation, and from the water level at which the lower end of the washing tank 3 is in contact with the water surface. Control to be higher.

Thus, the water heated by the heater 19 and the washing tub 3 come into contact with each other, whereby the heat of the heater 19 can be efficiently transmitted to the washing tub 3. And the temperature in the water tub 2 can be raised rapidly by the heat radiation of the washing tub 3. As a result, the inside of the water tank 2 can be sterilized efficiently. In particular, since the washing tub 3 disposed in the water tub 2 has a large mass and heat capacity, the temperature in the water tub 2 can be quickly raised by efficiently heating the washing tub 3. Further, in the tank sterilization step, the water level stored in the water tank 2 is lower than the lowest water level set in the normal washing operation and higher than the water level at which the lower end of the washing tank 3 is in contact with the water surface. The time and energy required for heating can be reduced.

As described above, the washing machine according to the present invention is useful as a washing machine because it can efficiently disinfect the water tank.

2 Water tank 3 Drum (washing tub)
7 Motor 9 Water supply valve (Water supply part)
13 Drain valve (drainage part)
16 Circulating water channel 17 Pump 19 Heater (heating part)
20 Water level detection part 21 Temperature detection part 22 Control part 27 Stirring blade

Claims

A washing tub provided rotatably in the water tub;
A water supply unit for supplying water into the water tank;
A heating unit for heating the water stored in the water tank;
A water level detection unit for detecting the water level of the water stored in the water tank;
A control unit that executes a washing operation and a tank washing operation including a tank sterilization step in which the water stored in the water tank is heated by the heating unit and the inside of the water tank is sterilized with steam generated by the heating. And
In the tank sterilization step, the control unit is configured such that the first water level stored in the water tank is lower than the lowest water level set in the washing operation, and the lower end of the washing tank is on the water surface. A washing machine that controls the water level so that it is higher than the water level.
The washing tub is driven to rotate around a horizontal axis,
2. The washing machine according to claim 1, wherein, in the tank sterilization step, the control unit controls the laundry tub to be rotationally driven while the water in the water tub is heated by the heating unit.
The washing tub is disposed at an inclination,
The control unit further performs a rinsing step of cleaning the inside of the water tank in the tank cleaning operation,
In the rinsing step, the control unit controls a second water level of the water stored in the water tub so that a lower end on a higher side of the washing tub is submerged, and the washing tub is removed from the tub. The washing machine according to claim 2, wherein the washing machine is controlled to rotate at a higher speed than at the time of the bacteria step.
In the tank cleaning operation, the water tank and the washing tank are cleaned,
The washing machine according to any one of claims 1 to 3, wherein the control unit executes a rinsing step of cleaning the inside of the water tank after the tank sterilization step in the tank cleaning operation.
The washing machine has a circulating water channel provided to guide the water in the water tub from the bottom of the water tub to the washing tub, and a pump for circulating the water in the water tub through the circulating water channel. ,
5. The washing machine according to claim 4, wherein, in the tank cleaning operation, the controller controls the pump to drive and circulate the water in the water tank through the circulation channel.
The washing machine according to claim 3, wherein the second water level is higher than the first water level.