washing machine

Abstract

A technology is provided that can improve the performance of a washing machine by controlling the rotation of a washing tub and the amount of circulating water in a circulation path. [Solution] A washing machine comprises a washing tub, a communication passage arranged outside the washing tub and connecting the bottom of the washing tub to an upper part of the washing tub above the bottom, a pump that sends water in the communication passage from the bottom to the upper part, a motor that rotates the washing tub, and a control unit that performs a washing cycle on clothes in the washing tub, wherein the control unit drives the pump and the motor in a first period from the start of the washing cycle and a second period after the first period has elapsed until the end of the washing cycle, and during the second period, the total amount of water sent by the pump from the bottom to the upper part is less than during the first period, and the rotation speed of the washing tub is less than during the first period.

Description

[Technical Field]

[0001] The technology disclosed in this specification relates to a washing machine. [Background technology]

[0002] Patent Document 1 discloses a drum-type washing machine. The drum-type washing machine includes a washing tub that stores laundry and rotates, an outer tub that stores the washing tub, a motor that drives the washing tub, a water intake located at the bottom of the outer tub, a circulation path that is connected at one end to the water intake and guides the water to a discharge port that opens into the washing tub, and a circulation pump that takes in washing liquid into the circulation path and discharges it into the washing tub. If it is determined that there is a high amount of dirt in the washing liquid, the circulation pump is controlled to reduce the amount of washing liquid circulating in the circulation path. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-58243 Summary of the Invention [Problem to be solved by the invention]

[0004] In a washing machine, the washing liquid is circulated through a circulation path while the washing tub is rotated. There has been no research into how to control the rotation of the washing tub and the amount of circulating water in the circulation path in order to improve the performance of the washing machine. This specification provides a technology that can improve the performance of a washing machine by controlling the rotation of the washing tub and the amount of circulating water in the circulation path. [Means for solving the problem]

[0005] The technology disclosed in this specification relates to a washing machine including a washing tub, a communication passage disposed outside the washing tub and connecting a bottom of the washing tub to an upper portion of the washing tub above the bottom, a pump for sending water in the communication passage from the bottom to the upper portion, a motor for rotating the washing tub, and a controller for executing a washing cycle on clothes in the washing tub, wherein the controller drives the pump and the motor in a first period from the start of the washing cycle and a second period after the first period has elapsed until the end of the washing cycle, and the total amount of water sent from the bottom to the upper portion by the pump in the second period may be smaller than in the first period, and the number of rotations of the washing tub may be smaller than in the first period. [Brief explanation of the drawings]

[0006] [Figure 1] 1 is a front view schematically illustrating a washing machine according to an embodiment of the present invention; [Figure 2] FIG. 2 is a cross-sectional view schematically showing the II-II cross section of FIG. [Figure 3] 1 shows a flowchart of a laundry process according to an embodiment. [Figure 4] 10 is a timing chart showing the drive timing of the motor and the pump in the first normal washing step of the embodiment. [Figure 5] 10 is a timing chart showing the drive timing of the motor and the pump in the second normal washing step of the embodiment. [Figure 6] 4 is a timing chart showing the drive timing of the motor and the pump in a first normal rinsing step of the embodiment. [Figure 7] 10 is a timing chart showing the drive timing of the motor and the pump in the second normal rinsing step of the embodiment. [Figure 8] 10 is a timing chart showing the drive timing of the motor and the pump in the first soft washing step of the embodiment. [Figure 9] 10 is a timing chart showing the drive timing of the motor and the pump in the second soft washing step of the embodiment. [Figure 10]10 is a timing chart showing the drive timing of the motor and the pump in the first soft rinsing step of the embodiment. [Figure 11] 10 is a timing chart showing the drive timing of the motor and the pump in the second soft rinsing step of the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0007] 1 and 2, washing machine 2 includes housing 4 and washing tub 10 disposed within housing 4. Washing machine 2 further includes motor 14, water supply channel 50 connected to washing tub 10, circulating water channel 20, and drying air channel 30. Washing tub 10 includes water tub 11 and storage tub 12 disposed within water tub 11.

[0008] Housing 4 houses washing tub 10. An opening 42 is provided in the front of housing 4 for inserting and removing clothes from storage tub 12. Opening 42 communicates with the inside of water tub 11 and storage tub 12. In addition, a door 40 for opening and closing opening 42 is provided in the front of housing 4.

[0009] The water tub 11 and storage tub 12 within the housing 4 are arranged at an angle relative to the horizontal. The washing machine 2 of this embodiment has a so-called inclined drum configuration. The water tub 11 is capable of storing water for washing. The storage tub 12, which is arranged within the water tub 11, is capable of storing clothes during the washing and drying operations of the washing machine 2. The storage tub 12 is rotatably arranged within the water tub 11 and is driven to rotate by a motor 14 arranged within the housing 4. The motor 14 selectively rotates the storage tub 12 in either a clockwise or counterclockwise direction when the storage tub 12 is viewed through the opening 42.

[0010] The downstream end of water supply line 50 is connected to the top of water tank 11. The upstream end of water supply line 50 is connected to a water source (e.g., a water main). Water supply line 50 supplies water from the water source into water tank 11. Water supply line 50 is provided with a water supply valve 52, and water is supplied into water tank 11 when water supply valve 52 is opened.

[0011] Next, we will explain circulation water channel 20 connected to water tub 11. Circulation water channel 20 is a path that circulates water discharged from water tub 11 and returns it to water tub 11. Circulation water channel 20 can take water stored in water tub 11 from the bottom of water tub 11 (i.e., washing tub 10) and return it to water tub 11 (i.e., washing tub 10). Circulation water channel 20 includes internal drain hose 16, filter unit 17, circulation pump 21, water supply hose 22, and fountain nozzle 23.

[0012] The interior drain hose 16 is connected to a drain outlet 15 at the bottom of the water tub 11. Water in the water tub 11 is drained from the drain outlet 15 into the interior drain hose 16. The downstream end of the interior drain hose 16 is connected to a filter unit 17. The interior drain hose 16 guides water drained from the water tub 11 to the filter unit 17. Note that the water drained from the water tub 11 may contain a mixture of detergent, fabric softener, etc. In this specification, water containing a mixture is also referred to as water. The filter unit 17 collects lint contained in the water drained through the interior drain hose 16. A drain pipe 18 is connected to the filter unit 17. The downstream end of the drain pipe 18 is connected to a drain destination outside the machine (e.g., an external drain hose (not shown)). The drain pipe 18 is provided with a drain valve 19, and when the drain valve 19 opens, water is drained through the drain pipe 18. The water in the water tank 11 is discharged through the internal drain hose 16 and the drain pipe 18 to a drain destination (for example, an external drain hose).

[0013] A circulation pump 21 is provided at the rear end of filter unit 17, to which internal drain hose 16 is connected. The upstream end of water supply hose 22 is connected to circulation pump 21. Circulation pump 21 is configured to suck in water discharged through internal drain hose 16 and discharge it into water supply hose 22. The downstream end of water supply hose 22 is connected to a water fountain nozzle 23 provided on the top of water tank 11. Water supply hose 22 guides water discharged from circulation pump 21 to water fountain nozzle 23.

[0014] Fountain nozzle 23 is fixed to the upper front side of water tub 11. Fountain nozzle 23 is positioned near opening 10a of water tub 11 and is configured to spray water into water tub 11 through opening 10a. Water guided to fountain nozzle 23 through water supply hose 22 is sprayed from fountain nozzle 23 into water tub 11. When circulation pump 21 operates, water in water tub 11 is drained through internal drain hose 16, and the water is returned to water tub 11 from the top end of water tub 11 through water supply hose 22 and fountain nozzle 23.

[0015] Next, we will explain the drying air duct 30. The drying air duct 30 is a path through which air flows to dry clothes. The upstream end and downstream end of the drying air duct 30 are connected to the water tub 11. The drying air duct 30 can circulate the air discharged from the water tub 11 and return it to the water tub 11 again.

[0016] Drying air duct 30 includes, in order from the upstream side, exhaust air duct 31, heat exchange air duct 32, and intake air duct 33. The upstream end of exhaust air duct 31 is connected to exhaust port 71 provided at the top of water tub 11. During drying operation, air inside water tub 11 and storage tub 12 is discharged into exhaust air duct 31 through exhaust port 71. The downstream end of exhaust air duct 31 is connected to heat exchange air duct 32. Air flowing through exhaust air duct 31 is sent to heat exchange air duct 32.

[0017] The heat exchange air passage 32 is provided between the exhaust air passage 31 and the supply air passage 33. The upstream end of the heat exchange air passage 32 is connected to the exhaust air passage 31, and the downstream end of the heat exchange air passage 32 is connected to the supply air passage 33.

[0018] An evaporator and a condenser (neither shown) of heat pump 80 are disposed within heat exchange air passage 32. The evaporator and condenser of heat pump 80 dehumidify and heat the air flowing within heat exchange air passage 32. As a result, the air supplied to water tub 11 and storage tub 12 during the drying operation is dehumidified and heated. The principle of heat pump 80 is already known, so a detailed description thereof will be omitted.

[0019] A blower fan 81 is also disposed in heat exchange air duct 32. Blower fan 81 is rotatably disposed in heat exchange air duct 32 and is rotated by driving motor 83. As blower fan 81 rotates during the drying operation, air is sent from the upstream side to the downstream side of heat exchange air duct 32. The air that has flowed through heat exchange air duct 32 is sent to intake air duct 33.

[0020] The upstream end of intake air duct 33 is connected to heat exchange air duct 32, and the downstream end of intake air duct 33 is connected to air intake port 72 provided at the rear of water tub 11. During the drying operation, air flowing through intake air duct 33 is supplied into water tub 11 and storage tub 12 through air intake port 72. The air supplied into storage tub 12 dries the clothes in storage tub 12.

[0021] The washing machine 2 further includes a clothing sensor 62 and a control unit 100. The clothing sensor 62 detects whether the clothes in the storage tub 12 have been removed from the storage tub 12. The clothing sensor 62 is, for example, a weight sensor that can detect the weight of the clothes in the storage tub 12. In this case, if the weight detected by the clothing sensor 62 (weight sensor) changes from above a predetermined threshold to below the threshold, it is determined that the clothes in the storage tub 12 have been removed. On the other hand, if the weight detected by the clothing sensor 62 (weight sensor) does not change from above a predetermined threshold to below the threshold, it is determined that the clothes in the storage tub 12 have not been removed.

[0022] In a modified example, the clothing sensor 62 may be an open / close sensor that can detect the opening and closing of the door 40 provided on the housing 4 of the washing machine 2. In this case, if the clothing sensor 62 (open / close sensor) detects the opening and closing of the door 40 after the washing or drying operation is completed, it is determined that the clothes have been removed from the storage tub 12. On the other hand, if the clothing sensor 62 (open / close sensor) does not detect the opening and closing of the door 40 after the washing or drying operation is completed, it is determined that the clothes have not been removed from the storage tub 12.

[0023] The control unit 100 includes, for example, a CPU and memories such as a ROM and a RAM. The control unit 100 causes the washing machine 2 to execute processes in accordance with a computer program stored in the memory. The processes executed by the control unit 100 will be described later.

[0024] The washing machine 2 can perform a washing operation, a drying operation, and a tub cleaning operation. The washing operation is an operation in which clothes are washed while they are stored in the storage tub 12. The washing operation includes, for example, a washing process, a rinsing process, and a spin-drying process. The drying operation is an operation in which clothes are dried while they are stored in the storage tub 12.

[0025] The tub cleaning operation is an operation in which the water tub 11 and storage tub 12 are cleaned when no clothes are stored in the storage tub 12. In the tub cleaning operation, water is supplied into the water tub 11 through the water supply line 50. In the tub cleaning operation, water is stored in the water tub 11, and the circulation pump 21 is operated to circulate the water in the water tub 11. In the tub cleaning operation, the water in the water tub 11 circulates between the circulation water line 20 and the water tub 11, thereby cleaning the inside of the circulation water line 20 as well.

[0026] The washing machine 2 has an operation unit 3 on the front side of the housing 4 that is operated by a user. The operation unit 3 has a plurality of buttons. The user operates the buttons on the operation unit 3 to cause the washing machine 2 to execute a process. The plurality of buttons include buttons for executing a washing operation, a drying operation, and a tub cleaning operation. In a modified example, the operation unit 3 may have a liquid crystal panel. The user may operate buttons displayed on the liquid crystal panel to cause the washing machine 2 to execute a process. When an operation is performed on the operation unit 3, the control unit 100 executes a process corresponding to the operation.

[0027] (Washing process during washing operation) The process executed by the control unit 100 during the washing operation will be described with reference to Fig. 3. The control unit 100 executes the washing process when a predetermined operation for the washing operation is executed by the user on the operation unit 3. The control unit 100 may also execute the washing process when a predetermined time designated in advance by the user arrives.

[0028] In the washing process, in S12, the control unit 100 determines whether or not the normal wash cycle should be performed during the washing process. In the washing process, either the normal wash cycle or the soft wash cycle is selectively performed. The user can select either the normal wash cycle or the soft wash cycle by operating the operation unit 3. The soft wash cycle places less stress on the clothes than the normal wash cycle. Note that the washing process may be selectively performed other than the normal wash cycle and the soft wash cycle. If the normal wash cycle has been selected by the user, the control unit 100 determines that the normal wash cycle should be performed (YES in S12), and if the soft wash cycle has been selected, the control unit 100 determines that the soft wash cycle should be performed (NO in S12).

[0029] If the result of S12 is YES, in S20, the control unit 100 executes a water supply step. Specifically, the control unit 100 opens the water supply valve 52 to supply water into the water tub 11 in an amount corresponding to the amount of laundry contained in the storage tub 12. The control unit 100 drives the circulation pump 21 to send water from the bottom to the top of the water tub 11. The control unit 100 repeatedly executes a process of driving the circulation pump 21 at a rotation speed of PR0 rpm for a timing Tw1 second and stopping it for a timing Tw2 second. The control unit 100 also drives the motor 14 to rotate the storage tub 12. The control unit 100 repeatedly executes a process of driving the motor 14 at PM0 rpm for a timing Tw3 second and stopping it for a timing Tw4 second. The control unit 100 rotates the storage tub 12 alternately clockwise and counterclockwise. Although the rotation speed of the motor 14 does not coincide with the rotation speed of the storage tank 12, the higher the rotation speed of the motor 14, the higher the rotation speed of the storage tank 12. Timing Tw1 + Timing Tw2 = Timing Tw3 + Timing Tw4. ​​That is, the drive start timing of the circulation pump 21 coincides with the drive start timing of the motor 14. In the following, the rotation speed is expressed in rpm.

[0030] Next, in S22, control unit 100 executes the first normal wash cycle. Specifically, control unit 100 pours an amount of detergent into washing tub 10 corresponding to the amount of laundry contained in storage tub 12. Next, control unit 100 drives motor 14 to rotate storage tub 12, and drives circulation pump 21 to send water from the bottom to the top of water tub 11 through circulation water channel 20.

[0031] Fig. 4 shows a timing chart illustrating the change over time in the drive states of the circulation pump 21 and the motor 14. The upper part of Fig. 4 shows the drive state of the circulation pump 21. The lower part of Fig. 4 shows the drive state of the motor 14. The same applies to Figs. 5 to 11.

[0032] At time t0, when the first normal washing step begins, the control unit 100 drives the motor 14 to rotate the storage tub 12 clockwise. The rotation direction of the storage tub 12 is not particularly limited, and the storage tub 12 may be rotated counterclockwise. This also applies to the following washing and rinsing steps. The control unit 100 increases the rotation speed of the motor 14 to and maintains the rotation speed MR1. From time t0 to time t1, the circulation pump 21 is stopped. When time t1 arrives, the control unit 100 drives the circulation pump 21 at the rotation speed PR1. From time t1 to time t2, the motor 14 is maintained at the rotation speed MR1, and the circulation pump 21 is maintained at the rotation speed PR1. At time t2, the control unit 100 stops the circulation pump 21. From time t2 to time t3, the circulation pump 21 is stopped. The control unit 100 gradually reduces the rotation speed of the motor 14 so that the rotation of the storage tub 12 switches from clockwise to counterclockwise at time t3.

[0033] From timing t3 to timing t6, the circulation pump 21 is driven at the rotation speed PR1 at timing t4 and stopped at timing t5, similarly to timing t0 to timing t3. The motor 14 is driven in the same manner as from timing t0 to timing t3, except that the rotation direction of the storage tank 12 is reversed.

[0034] In the first normal washing step, processing from timing t0 to t6 is repeatedly performed. The time from timing t0 to t3 is, for example, 30 seconds, and the time from timing t0 to t6 is, for example, 60 seconds. The time from timing t0 to t1, timing t2 to t3, timing t3 to t4, and timing t5 to t6 is, for example, 6 seconds, and the time from timing t1 to t2 and timing t4 to t5 is, for example, 18 seconds. The first normal washing step is performed for, for example, 4 minutes. The rotation speed PR1 is greater than the rotation speed PR0. The rotation speed MR1 is smaller than the rotation speed MR0.

[0035] When the first normal washing step is completed, in S24, the control unit 100 executes the second normal washing step. At the start of the second normal washing step, the circulation pump 21 and the motor 14 are stopped. The second normal washing step differs from the first normal washing step in the driving states of the circulation pump 21 and the motor 14. As shown in FIG. 5, at time t7 when the second normal washing step starts, the control unit 100 drives the motor 14 to rotate the storage tub 12 clockwise. The control unit 100 increases the rotation speed of the motor 14 to and maintains the rotation speed MR2. From time t7 to time t8, the circulation pump 21 is stopped. At time t8, the circulation pump 21 is driven at the rotation speed PR2. From time t8 to time t9, the motor 14 is maintained at the rotation speed MR2, and the circulation pump 21 is maintained at the rotation speed PR2. At time t9, the control unit 100 stops the circulation pump 21. Between timing t9 and timing t10, the circulation pump 21 is stopped. The control unit 100 gradually reduces the rotation speed of the motor 14 so that the rotation of the storage tank 12 switches from clockwise to counterclockwise at timing t10.

[0036] From timing t10 ​​to timing t13, the circulation pump 21 is driven at the rotation speed PR2 at timing t11, as in timing t7 to timing t10, and is stopped at timing t12. The motor 14 is driven in the same manner as in timing t7 to timing t10, except that the rotation direction of the storage tank 12 is reversed.

[0037] In the second normal washing step, processing from timing t7 to t13 is repeatedly performed. The time from timing t7 to t10 is, for example, 10 seconds, and the time from timing t7 to t13 is, for example, 20 seconds. The time from timing t7 to t8, timing t9 to t10, timing t10 ​​to t11, and timing t12 to t13 is, for example, 4 seconds, and the time from timing t8 to t9 and timing t11 to t12 is, for example, 4 seconds. The second normal washing step is performed for, for example, 6 minutes.

[0038] The normal washing process ends when the second normal washing process ends. The rotation speed PR2 of the circulation pump 21 in the second normal washing process is lower than the rotation speed PR1 of the circulation pump 21 in the first normal washing process. The proportion of the period during which the circulation pump 21 is driven in the entire second normal washing process is shorter than the proportion of the period during which the circulation pump 21 is driven in the entire first normal washing process. Therefore, the total amount of water circulated by the circulation pump 21 in the second normal washing process, i.e., the total amount of water delivered from the bottom to the top of the washing tub 10, is lower than the total amount of water delivered from the bottom to the top of the washing tub 10 in the first normal washing process.

[0039] In the first normal wash step at the beginning of the normal wash step, it is preferable to wash the clothes by rotating the storage tub 12, by penetrating the detergent into the clothes as early as possible. In the first normal wash step, the operating period of the circulation pump 21 is extended, thereby pouring detergent-containing water onto the clothes over a long period of time, thereby allowing the detergent to penetrate the clothes early. On the other hand, in the second normal wash step at the end of the normal wash step, the main purpose is to wash the clothes by rotating the storage tub 12. Therefore, by shortening the operating period of the circulation pump 21 in the second normal wash step, the noise generated by the circulation pump 21 can be reduced.

[0040] The rotation speed MR2 of motor 14 in the second normal wash cycle is higher than the rotation speed MR1 of motor 14 in the first normal wash cycle. The first normal wash cycle aims to pour detergent solution evenly onto the clothes so that they can be washed by mechanical force, i.e., the rotation of storage tub 12, in the second normal wash cycle. By controlling the rotation speed of motor 14 to a low value, the clothes in washing tub 10 are prevented from repelling water, which makes it easier for detergent to penetrate the clothes. Furthermore, by controlling the rotation speed of motor 14 to a low value, power consumption can be reduced. In the second normal wash cycle, the rotation speed of storage tub 12 is increased compared to the first normal wash cycle, thereby washing the clothes more powerfully. Furthermore, by shortening the interval between timings for switching the rotation direction of storage tub 12, tangling of the clothes in the next cycle is prevented.

[0041] In the first normal wash cycle, the drive switching timing at which circulation pump 21 is switched between drive and stop is linked to the direction switching timing at which the rotation direction of motor 14 is switched (i.e., timing t3, timing t6). Specifically, circulation pump 21 is stopped at the direction switching timing. Circulation pump 21 is driven while the rotation of motor 14, i.e., the rotation of storage tub 12, is stable. This allows the detergent-containing water delivered by circulation pump 21 to be evenly poured onto the laundry.

[0042] In the second normal washing step, the drive switching timing at which the circulation pump 21 is switched between being driven and being stopped is linked to the direction switching timing at which the rotation direction of the motor 14 is switched (i.e., timing t10, timing t13). Specifically, the circulation pump 21 is stopped at the direction switching timing. The circulation pump 21 is driven while the rotation of the motor 14, i.e., the rotation of the storage tub 12, is stable. This reduces the noise of the circulation pump 21 and allows the circulation pump 21 to be driven efficiently, compared to a configuration in which the circulation pump 21 is driven continuously.

[0043] After the washing cycle is completed, the control unit 100 executes a water supplying step in S26. During the water supplying step in S26, water is supplied to the water tub 11 for the subsequent rinsing cycle. Specifically, the control unit 100 opens the water supply valve 52 to supply water into the water tub 11 in an amount corresponding to the amount of laundry contained in the storage tub 12. The control unit 100 drives the circulation pump 21 to send water from the bottom to the top of the water tub 11. The control unit 100 drives the circulation pump 21 at a rotation speed PR3. The control unit 100 also drives the motor 14 to rotate the storage tub 12. The control unit 100 drives the motor 14 at a rotation speed MR3 to rotate the storage tub 12 alternately clockwise and counterclockwise every Tw5 seconds. The rotation speed PR3 is higher than the rotation speed PR0. During the water supplying step, water can be absorbed into the laundry.

[0044] The control unit 100 may execute a shower rinsing process between the process of S24 and the process of S26. In the shower rinsing process, the control unit 100 may open the water supply valve 52 to supply water into the water tub 11, while continuously driving the circulation pump 21 and the motor 14 at a constant rotation speed.

[0045] After the water supply process is completed, in S28, the control unit 100 executes a first normal rinsing process. The first normal rinsing process differs from the first normal washing process and the second normal washing process in the drive states of the circulation pump 21 and the motor 14. As shown in FIG. 6, at timing t20, when the first normal rinsing process starts, the control unit 100 drives the motor 14 to rotate the storage tub 12 clockwise. The control unit 100 increases the rotation speed of the motor 14 to and maintains the rotation speed MR4. From timing t20 to timing t21, the circulation pump 21 is stopped. At timing t21, the control unit 100 drives the circulation pump 21 at the rotation speed PR4. From timing t21 to timing t22, the motor 14 is maintained at the rotation speed MR4, and the circulation pump 21 is maintained at the rotation speed PR4. At timing t22, the control unit 100 stops the circulation pump 21. From timing t22 to timing t23, the circulation pump 21 is stopped. The control unit 100 gradually reduces the rotation speed of the motor 14 so that the rotation of the storage tub 12 switches from clockwise to counterclockwise at timing t23.

[0046] From timing t23 to timing t26, the circulation pump 21 is driven at the rotation speed PR4 at timing t24, as in timing t20 to timing t23, and is stopped at timing t25. The motor 14 is driven in the same manner as in timing t23 to timing t26, except that the rotation direction of the storage tank 12 is reversed.

[0047] In the first normal rinsing step, processing from timing t20 to t26 is repeatedly performed. The time from timing t20 to t23 is, for example, 20 seconds, and the time from timing t20 to t26 is, for example, 40 seconds. The time from timing t20 to t21, timing t22 to t23, timing t23 to t24, and timing t25 to t26 is, for example, 2 seconds, and the time from timing t21 to t22 and timing t24 to t25 is, for example, 16 seconds. The first normal rinsing step is performed for, for example, 1 minute.

[0048] After the first normal rinsing step is completed, in S30, the control unit 100 executes the second normal rinsing step. The second normal rinsing step differs from the first, second, and first normal rinsing steps in the drive states of the circulation pump 21 and the motor 14. As shown in FIG. 7 , at timing t28 when the second normal rinsing step is started, the control unit 100 drives the circulation pump 21 at rotation speed PR5. During the second normal rinsing step, the circulation pump 21 is maintained at rotation speed PR5. At timing t28, the control unit 100 further increases the rotation speed of the motor 14 to rotation speed MR5 and maintains it there. At timing t29, the control unit 100 gradually reduces the rotation speed of the motor 14 so that the rotation of the storage tub 12 switches from clockwise to counterclockwise.

[0049] From timing t29 to timing t30, the motor 14 is driven in the same manner as in timing t28 to timing t29, except that the rotation direction of the storage tub 12 is reversed. The second normal rinsing step is performed for, for example, one minute.

[0050] In the second normal rinsing step, the process from timing t28 to t30 is repeatedly executed. The period from timing t27 to t28 is, for example, 5 seconds, and the period from timing t27 to t29 is, for example, 10 seconds.

[0051] The normal rinsing process ends when the second normal rinsing process ends. The rotation speed PR5 of circulation pump 21 in the second normal rinsing process is equal to the rotation speed PR4 of circulation pump 21 in the first normal rinsing process. Furthermore, circulation pump 21 continues to be driven throughout the entire second normal rinsing process. Therefore, the total amount of water circulated by circulation pump 21 in the second normal rinsing process, i.e., the total amount of water delivered from the bottom to the top of washing tub 10, is greater than the total amount of water delivered from the bottom to the top of washing tub 10 in the first normal rinsing process.

[0052] In the first normal rinsing step, which is the early stage of the normal rinsing step, by intermittently stopping circulation pump 21, it is possible to prevent a shortage of water at the bottom of water tub 11. In the first normal rinsing step, the drive switch timing at which circulation pump 21 is switched between being driven and being stopped is linked to the direction switch timing at which the rotation direction of motor 14 is switched (i.e., timing t23, timing t26). Specifically, circulation pump 21 is stopped at the direction switch timing. Circulation pump 21 is driven while the rotation of motor 14, i.e., the rotation of storage tub 12, is stable. This allows water delivered by circulation pump 21 to be evenly poured onto the clothes. This allows water to penetrate the clothes evenly during the rinsing step.

[0053] The purpose of the first normal rinse step, which is the early stage of the normal rinse step, is to soak the clothes evenly in water, and then to prepare the clothes for rinsing by rotating storage tub 12 in the final stage of the normal rinse step. By soaking the clothes evenly in water in the first normal rinse step, the timing of switching the direction of motor 14 is shortened in the second normal rinse step, and the detergent is squeezed out of the clothes while the constantly driven circulation pump 21 continues to pour water onto the clothes, thereby improving rinsing performance.

[0054] The rotation speed MR5 of motor 14 in the second normal rinsing step is higher than the rotation speed MR4 of motor 14 in the first normal rinsing step. The first normal rinsing step aims to evenly pour water onto the clothes, thereby enabling the second normal rinsing step to mechanically squeeze detergent from the clothes. By controlling the rotation speed of motor 14 to a low value, the clothes in washing tub 10 are prevented from repelling water, which facilitates water penetration into the clothes. Furthermore, by controlling the rotation speed of motor 14 to a low value, power consumption can be reduced. In the second normal rinsing step, the rotation speed of storage tub 12 is increased compared to the first normal rinsing step, thereby rinsing the clothes more powerfully. Furthermore, by shortening the interval between timings for switching the rotation direction of storage tub 12, tangling of the clothes in the next step can be prevented.

[0055] When the normal rinsing step is completed, in S32, the control unit 100 executes the spin-drying step, and the washing process is completed. In the spin-drying step, the control unit 100 rotates the motor 14 at MR6.

[0056] If the result of S12 is NO, in S40, control unit 100 executes the same water supply step as in S20. Next, in S42, control unit 100 executes a first soft wash step. Specifically, control unit 100 dispenses an amount of detergent into washing tub 10 corresponding to the amount of laundry contained in storage tub 12. Next, control unit 100 drives motor 14 to rotate storage tub 12 and drives circulation pump 21 to send water from the bottom to the top of water tub 11 through circulation water channel 20.

[0057] 8, at timing t40 when the first soft wash step starts, the control unit 100 drives the motor 14 to rotate the storage tub 12 clockwise. The control unit 100 increases the rotation speed of the motor 14 to and maintains the rotation speed MR10. The control unit 100 controls the rotation speed of the motor 14 so that the motor 14 is stopped at timing t41. Between timing t40 and timing t41, the circulation pump 21 is stopped.

[0058] At time t42, the circulation pump 21 is driven at the rotation speed PR10. Between time t42 and time t43, the motor 14 is stopped and the circulation pump 21 is maintained at the rotation speed PR10. At time t43, the control unit 100 stops the circulation pump 21. Between time t43 and time t44, the circulation pump 21 and the motor 14 are both stopped.

[0059] From timing t44 to timing t48, the circulation pump 21 is driven at the rotation speed PR10 at timing t46, as in timing t40 to timing t44, and is stopped at timing t47. The motor 14 is driven in the same manner as in timing t40 to timing t44, except that the rotation direction of the storage tank 12 is reversed.

[0060] In the first soft washing step, the process from timing t40 to t48 is repeatedly executed. The time from timing t40 to t44 is, for example, 30 seconds, and the time from timing t40 to t48 is, for example, 60 seconds. The time from timing t40 to t41 and timing t44 to t45 is, for example, 5 seconds, and the time from timing t41 to t42 and timing t45 to t46 is, for example, 6 seconds. The time from timing t42 to t43 and timing t46 to t47 is, for example, 8 seconds, and the time from timing t43 to t44 and timing t47 to t48 is, for example, 11 seconds. The first soft washing step is executed for, for example, 4 minutes. The rotation speed PR10 is lower than both rotation speeds PR1 and PR2 in the normal washing step. The rotation speed MR10 is lower than both rotation speeds MR1 ​​and MR2 in the normal washing step.

[0061] When the first soft wash step is completed, in S44, the control unit 100 executes the second soft wash step. At the start of the second soft wash step, the circulation pump 21 and the motor 14 are stopped. The second soft wash step differs from the first soft wash step in the driving states of the circulation pump 21 and the motor 14. As shown in FIG. 9, at time t50 when the second soft wash step starts, the control unit 100 drives the motor 14 to rotate the storage tub 12 clockwise. The control unit 100 increases the rotation speed of the motor 14 to and maintains it at rotation speed MR11. The control unit 100 controls the rotation speed of the motor 14 so that the motor 14 is stopped at time t51. Between time t50 and time t51, the circulation pump 21 is stopped.

[0062] At time t52, the circulation pump 21 is driven at the rotation speed PR11. Between time t52 and time t53, the motor 14 is stopped and the circulation pump 21 is maintained at the rotation speed PR11. At time t53, the control unit 100 stops the circulation pump 21. Between time t53 and time t54, the circulation pump 21 and the motor 14 are both stopped.

[0063] From timing t54 to timing t58, the circulation pump 21 is driven at the rotation speed PR11 at timing t56, as in timing t50 to timing t54, and is stopped at timing t57. The motor 14 is driven in the same manner as in timing t50 to timing t54, except that the rotation direction of the storage tank 12 is reversed.

[0064] In the second soft wash step, the process from timing t50 to t58 is repeatedly performed. For example, the time from timing t50 to t54 is 20 seconds, and the time from timing t50 to t58 is 40 seconds. For example, the time from timing t50 to t51 and timing t54 to t55 is 5 seconds, and the time from timing t51 to t52 and timing t55 to t56 is 3 seconds. For example, the time from timing t52 to t53 and timing t56 to t57 is 4 seconds, and the time from timing t53 to t54 and timing t57 to t58 is 8 seconds. The second soft wash step is performed for, for example, 6 minutes. The rotation speed PR11 is smaller than both rotation speeds PR1 and PR2 in the normal wash step and is smaller than the rotation speed PR10. The rotation speed MR11 is smaller than both rotation speeds MR1 ​​and MR2 in the normal wash step and is smaller than the rotation speed MR10.

[0065] The soft wash cycle ends when the second soft wash cycle ends. The rotation speed PR11 of the circulation pump 21 in the second soft wash cycle is lower than the rotation speed PR10 of the circulation pump 21 in the first soft wash cycle. The proportion of the period during which the circulation pump 21 is driven in the entire second soft wash cycle is shorter than the proportion of the period during which the circulation pump 21 is driven in the entire first soft wash cycle. Therefore, the total amount of water circulated by the circulation pump 21 in the second soft wash cycle, i.e., the total amount of water delivered from the bottom to the top of the washing tub 10, is lower than the total amount of water delivered from the bottom to the top of the washing tub 10 in the first soft wash cycle.

[0066] As a result, in the first soft wash step at the beginning, as in the normal wash step, the driving period of the circulation pump 21 is extended, so that detergent-containing water is poured onto the clothes over a long period of time, allowing the detergent to penetrate the clothes quickly. On the other hand, in the second soft wash step at the end of the normal wash step, the driving period of the circulation pump 21 is shortened, so that the noise generated by the circulation pump 21 can be suppressed.

[0067] The rotation speed MR11 of motor 14 in the second soft wash cycle is higher than the rotation speed MR10 of motor 14 in the first soft wash cycle. As a result, as in the normal wash cycle, by controlling the rotation speed of motor 14 to be lower in the first soft wash cycle, it is possible to prevent the clothes in washing tub 10 from repelling water. This makes it easier for detergent to penetrate the clothes. Furthermore, by controlling the rotation speed of motor 14 to be lower, it is possible to reduce power consumption. In the second soft wash cycle, the rotation speed of storage tub 12 is increased compared to the first soft wash cycle, so that the clothes can be washed by the rotation of storage tub 12.

[0068] In the first soft wash step and the second soft wash step, the circulation pump 21 is driven while the motor 14 is stopped. This makes it possible to suppress damage to the clothes and foaming of the detergent in the soft wash step.

[0069] When the soft wash cycle is completed, in S46, control unit 100 executes the water supply cycle, similar to S26. In the water supply cycle of S46, water is supplied to water tub 11 for the subsequent rinse cycle. The rotation speed MR14 of motor 14 in the water supply cycle of S46 is lower than the rotation speed MR3 of motor 14 in the water supply cycle of S46. This can reduce damage to clothes. Other control operations executed by control unit 100 in S46 are similar to those in S26.

[0070] When the water supply step is completed, in S48, the control unit 100 executes a first soft rinse step. The first soft rinse step differs from the first soft wash step and the second soft wash step in the drive states of the circulation pump 21 and the motor 14. As shown in FIG. 10, at timing t60 when the first soft rinse step starts, the control unit 100 drives the motor 14 to rotate the storage tub 12 clockwise. The control unit 100 increases the rotation speed of the motor 14 to and maintains the rotation speed MR12. The control unit 100 controls the rotation speed of the motor 14 so that the motor 14 is stopped at timing t61. Between timing t60 and timing t61, the circulation pump 21 is stopped.

[0071] At time t62, the circulation pump 21 is driven at the rotation speed PR12. Between time t62 and time t63, the motor 14 is stopped and the circulation pump 21 is maintained at the rotation speed PR12. At time t63, the control unit 100 stops the circulation pump 21. Between time t63 and time t64, the circulation pump 21 and the motor 14 are both stopped.

[0072] From timing t64 to timing t68, the circulation pump 21 is driven at the rotation speed PR12 at timing t66, as in timing t60 to timing t64, and is stopped at timing t67. The motor 14 is driven in the same manner as in timing t60 to timing t64, except that the rotation direction of the storage tank 12 is reversed.

[0073] In the first soft rinsing step, the process from timing t60 to t68 is repeatedly performed. For example, the time from timing t60 to t64 is 30 seconds, and the time from timing t60 to t68 is 60 seconds. For example, the time from timing t60 to t61 and timing t64 to t65 is 10 seconds, and the time from timing t61 to t62 and timing t65 to t66 is 6 seconds. For example, the time from timing t62 to t63 and timing t66 to t67 is 8 seconds, and the time from timing t63 to t64 and timing t67 to t68 is 11 seconds. The first soft washing step is performed for, for example, 1 minute. The rotation speed PR12 is lower than both rotation speeds PR4 and PR5 in the normal rinsing step. The rotation speed MR12 is lower than both rotation speeds MR4 and MR5 in the normal washing step.

[0074] When the first soft rinsing process is completed, in S50, the control unit 100 executes the second soft rinsing process. At the start of the second soft rinsing process, the circulation pump 21 and the motor 14 are stopped. The second soft rinsing process differs from the first soft rinsing process in the driving states of the circulation pump 21 and the motor 14. As shown in FIG. 11 , at time t70 when the second soft rinsing process starts, the control unit 100 drives the motor 14 to rotate the storage tub 12 clockwise. The control unit 100 increases the rotation speed of the motor 14 to and maintains it at rotation speed MR13. The control unit 100 controls the rotation speed of the motor 14 so that the motor 14 is stopped at time t71. Between time t70 and time t71, the circulation pump 21 is stopped.

[0075] At time t72, the circulation pump 21 is driven at the rotation speed PR 13. Between time t72 and time t73, the motor 14 is stopped and the circulation pump 21 is maintained at the rotation speed PR 13. At time t73, the control unit 100 stops the circulation pump 21. Between time t73 and time t74, the circulation pump 21 and the motor 14 are both stopped.

[0076] From timing t74 to timing t78, the circulation pump 21 is driven at the rotation speed PR13 at timing t76, as in timing t70 to timing t74, and is stopped at timing t77. The motor 14 is driven in the same manner as in timing t70 to timing t74, except that the rotation direction of the storage tank 12 is reversed.

[0077] In the second soft rinsing step, the process from timing t70 to t78 is repeatedly performed. For example, the time from timing t70 to t74 is 20 seconds, and the time from timing t70 to t78 is 40 seconds. For example, the time from timing t70 to t71 and timing t74 to t75 is 5 seconds, and the time from timing t71 to t72 and timing t75 to t76 is 3 seconds. For example, the time from timing t72 to t73 and timing t76 to t77 is 4 seconds, and the time from timing t73 to t74 and timing t77 to t78 is 8 seconds. The second soft rinsing step is performed for, for example, 1 minute. The rotation speed PR13 is smaller than both of the rotation speeds PR4 and PR5 in the normal rinsing step and is the same as the rotation speed PR12. In a modified example, the rotation speed PR13 may be different from the rotation speed PR12. The rotation speed MR13 is smaller than either of the rotation speeds MR4 and MR5 in the normal rinsing step, and is the same as the rotation speed MR12. Note that, in a modified example, the rotation speed MR13 may be different from the rotation speed MR12.

[0078] In the soft rinse step, the control unit 100 repeatedly executes the water supply step of S46, the first soft rinse step of S48, and the second soft rinse step of S50 a predetermined number of times (e.g., three times). The predetermined number of times may be a predetermined number of times, or may be determined appropriately by the control unit 100 according to the degree of rinsing. This allows the laundry to be rinsed while suppressing the rotation speed of the motor 14. This reduces damage to the laundry.

[0079] In the first soft rinse step and the second rinse step, similar to the soft wash step, the circulation pump 21 is driven while the motor 14 is stopped. This makes it possible to suppress damage to the clothes and foaming of the detergent in the soft wash step.

[0080] When the normal rinsing step is completed, in S52, the control unit 100 executes the spin-drying step, and the washing process is completed. In the spin-drying step, the control unit 100 rotates the motor 14 by the MR14.

[0081] (Correspondence) The period during which the first normal wash step is performed and the period during which the first soft wash step is performed are each an example of a "first period," and the period during which the second normal wash step and the second soft wash step are each an example of a "second period." The period during which the first normal rinse step is performed and the period during which the first soft rinse step is performed are each an example of a "third period," and the period during which the second normal rinse step and the second soft rinse step are each an example of a "fourth period."

[0082] (Variation) (1) In the normal rinsing process, the control unit 100 may control the motor 14 and the circulation pump 21 in the same manner in the first normal rinsing process and the second normal rinsing process. Similarly, in the soft rinsing process, the control unit 100 may control the motor 14 and the circulation pump 21 in the same manner in the first soft rinsing process and the second soft rinsing process.

[0083] (2) In the normal washing process, the control unit 100 may control the motor 14 and the circulation pump 21 in the same manner in the first normal washing process and the second normal washing process. Similarly, in the soft washing process, the control unit 100 may control the motor 14 and the circulation pump 21 in the same manner in the first soft washing process and the second soft washing process.

[0084] Although specific examples of the present invention have been described in detail above, these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and variations of the specific examples exemplified above. The technical elements described in this specification or drawings exhibit technical utility alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. Furthermore, the technology exemplified in this specification or drawings can achieve multiple objectives simultaneously, and achieving one of these objectives itself has technical utility. [Explanation of symbols]

[0085] 2: washing machine, 10: washing tub, 10a: opening, 11: water tub, 12: storage tub, 14: motor, 20: circulation water channel, 21: circulation pump, 100: control unit

Claims

1. A washing machine and a communication passage disposed outside the washing tub and communicating the bottom of the washing tub with an upper portion of the washing tub above the bottom; a pump that sends water in the communication passage from the bottom to the top; a motor for rotating the washing tub; a control unit that executes a washing process on the clothes in the washing tub, The control unit drives the pump and the motor during a first period from the start of the washing process and a second period after the first period has elapsed and until the end of the washing process, In the second period, the total amount of water pumped from the bottom to the top by the pump is smaller than in the first period, and the number of rotations of the washing tub is smaller than in the first period.

2. The motor is capable of switching the rotation direction of the washing tub, The washing machine according to claim 1 , wherein the control unit switches the rotation direction of the washing tub by the motor while the pump is stopped during at least one of the first period and the second period.

3. The washing machine according to claim 1 , wherein the control unit drives the pump while rotation of the washing tub by the motor is stopped during at least one of the first period and the second period.

4. The control unit Furthermore, a rinsing process is performed on the clothes in the washing tub, The pump and the motor are driven during a third period from the start of the rinsing step and a fourth period from the end of the rinsing step after the third period has elapsed, 4. The washing machine according to claim 1, wherein during the fourth period, a total amount of water pumped from the bottom portion to the upper portion by the pump is greater than during the third period, and a rotation speed of the washing tub is greater than during the third period.

5. A washing machine and a communication passage disposed outside the washing tub and communicating the bottom of the washing tub with an upper portion of the washing tub above the bottom; a pump that sends water in the communication passage from the bottom to the top; a motor for rotating the washing tub; a control unit that executes a rinsing process on the clothes in the washing tub, The control unit drives the pump and the motor during a third period from the start of the rinsing process and a fourth period from the end of the rinsing process after the third period has elapsed, In the fourth period, the total amount of water pumped from the bottom to the top by the pump is greater than in the third period, and the number of rotations of the washing tub is greater than in the third period.

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