Washing machine

Abstract

To provide a washing machine in which, in the case where water is stored in a washing tub at the starting time of a washing operation, when a detergent is contained in the water, the detergent is not supplied, and when the detergent is not contained in the water, the detergent is supplied.SOLUTION: When a washing operation is started, in the case where it is determined that water is stored in a washing tub based on the detection result of a water level detection part 206, a control part 201 detects electric conductivity of water in the washing tub by an electric conductivity detection part 60 and determines whether or not a detergent is contained in the water in the washing tub based on the detection result of the electricity conductivity. In the case where it is determined that the detergent is not contained in the water in the washing tub, in a washing step, the control part 201 allows a display part 204 to perform display regarding an input amount of detergent, and in the case where it is determined that the detergent is contained in the water in the washing tub, it does not allow the display part 204 to perform display regarding the input amount of the detergent, as detergent supply processing for supplying the detergent in the washing tub.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a washing machine. [Background technology]

[0002] In a washing machine, if the power is turned off during the washing cycle due to a power outage or the like, when the power is turned back on and the start operation is performed, the washing operation may start from the beginning with water containing detergent in the washing tub. In this case, if detergent is added to the washing tub by the user's hand or the automatic detergent dispenser, the washing operation will be performed with an excessive amount of detergent.

[0003] Therefore, in order to avoid excessive supply of detergent, Patent Document 1 describes a washing machine that performs the washing cycle without operating the detergent supply device (automatic detergent dispenser) when water is already stored in the washing tub (washing tub) at the start of operation. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 63-209697 Summary of the Invention [Problem to be solved by the invention]

[0005] If a user starts a washing operation after pouring leftover bath water or the like into the washing tub in advance, the washing operation may start with water still stored in the washing tub.

[0006] In such a case, the washing machine of Patent Document 1 may perform the washing process without supplying detergent.

[0007] To provide a washing machine that can supply detergent when water is stored in a washing tub at the start of a washing operation, without supplying detergent if the water contains detergent, and can supply detergent when the water does not contain detergent. [Means for solving the problem]

[0008] A washing machine according to a main aspect of the present invention includes a washing tub including an outer tub for storing water and an inner tub disposed within the outer tub for accommodating laundry, a water supply device for supplying water into the washing tub, a water level detection unit for detecting the water level in the washing tub, a conductivity detection unit for detecting the conductivity of the water stored in the washing tub, and a control unit for executing a washing operation including a washing cycle, a rinsing cycle, and a spin-drying cycle. When the washing operation is started, the control unit determines whether water is stored in the washing tub based on the detection result by the water level detection unit, and if it is determined that water is stored in the washing tub, detects the conductivity using the conductivity detection unit and determines whether the water in the washing tub contains detergent based on the conductivity detection result. If it is determined that the water in the washing tub does not contain detergent, the control unit performs a detergent supply process to supply detergent into the washing tub during the washing cycle. If it is determined that the water in the washing tub contains detergent, the control unit does not perform the detergent supply process during the washing cycle.

[0009] According to the washing machine of this aspect, when water is stored in the washing tub at the start of a washing operation, if the water contains detergent, the detergent is not supplied, and if the water does not contain detergent, the detergent is supplied.

[0010] The washing machine according to this aspect may further include a display unit. In this case, the detergent supply process may include a process in which the control unit causes the display unit to display an amount of detergent added.

[0011] According to the above configuration, when the water in the washing tub does not contain detergent, a display regarding the amount of detergent to be added is displayed, thereby urging the user to add detergent.

[0012] The washing machine according to this aspect may further include a detergent tank for storing detergent and an automatic detergent dispenser for automatically dispensing the detergent from the detergent tank into the washing tub. In this case, the detergent supply process may include a process in which the control unit operates the automatic detergent dispenser.

[0013] According to the above configuration, when the water in the washing tub does not contain detergent, the automatic detergent dispenser can automatically dispense detergent.

[0014] The washing machine according to this aspect may further include a display unit, an automatic detergent dispenser having a detergent tank for storing detergent and automatically dispensing the detergent from the detergent tank into the washing tub, and a memory unit. In this case, the washing machine may be configured to enable or disable a setting for automatically dispensing detergent by the automatic detergent dispenser. The memory unit may store detergent-added information indicating that water containing detergent dispensed from the automatic detergent dispenser is stored in the washing tub. The control unit may be configured to, when determining that water is stored in the washing tub at the start of the washing operation, cause the automatic detergent dispenser to automatically dispense detergent during the washing process if the automatic detergent dispenser setting is on and the control unit determines that the water in the washing tub does not contain detergent based on the fact that the detergent-added information is not stored in the memory unit, or not cause the automatic detergent dispenser to automatically dispense detergent during the washing process if the control unit determines that the water in the washing tub contains detergent based on the fact that the detergent-added information is stored in the memory unit. Furthermore, when the control unit determines that water is stored in the washing tub at the start of the washing operation, and when the automatic dispensing setting is off, if the control unit determines that the water in the washing tub does not contain detergent based on the conductivity detection result by the conductivity detection unit, it can be configured to cause the display unit to display information about the amount of detergent to be added as the detergent supply process, and if the control unit determines that the water in the washing tub contains detergent based on the conductivity detection result by the conductivity detection unit, it can be configured not to cause the display unit to display information about the amount of detergent to be added.

[0015] With the above configuration, when the automatic detergent dispensing setting is on and detergent-added information is available, the presence or absence of detergent in the water in the washing tub is determined based on whether or not the detergent-added information is stored, so that the presence or absence of detergent can be quickly determined without requiring time to measure the conductivity of the water in the washing tub. When the water in the washing tub does not contain detergent, the automatic detergent dispensing device can automatically dispense detergent into the washing tub.

[0016] Furthermore, when the automatic detergent dispensing setting is off and information on whether detergent has been dispensed is unavailable, the presence or absence of detergent in the washing tub is determined based on the conductivity detection result, so that even when the automatic detergent dispenser does not automatically dispense detergent, it is possible to determine whether detergent is present in the washing tub. When the water in the washing tub does not contain detergent, the display unit displays the amount of detergent to be dispensed, prompting the user to dispense detergent.

[0017] In the washing machine according to this aspect, the control unit may be configured to detect the conductivity of the water in the washing tub that does not contain detergent using the conductivity detection unit as a reference conductivity, and determine that the water in the washing tub contains detergent if the difference between the conductivity detected at the start of the washing operation and the reference conductivity is greater than a threshold value.

[0018] According to the above configuration, even if the conductivity of the water supplied from the faucet to the washing machine varies depending on the region, season, etc., it is possible to accurately determine whether the water in the washing tub contains detergent.

[0019] The washing machine according to this aspect may further include a drain unit for draining water from the washing tub. In this case, when the washing operation starts with the rinsing step, if the control unit determines that the water in the washing tub contains detergent, the control unit drains water from the washing tub using the drain unit and then supplies water to the washing tub using the water supply device in the rinsing step, and if the control unit determines that the water in the washing tub does not contain detergent, the control unit supplies water to the washing tub using the water supply device in the rinsing step without draining water from the washing tub.

[0020] According to the above configuration, it is possible to prevent the laundry from being rinsed poorly due to rinsing with water containing detergent. [Effects of the Invention]

[0021] According to the present invention, when water is stored in a washing tub at the start of a washing operation, a washing machine can be provided in which, if the water contains detergent, the detergent is not supplied, and if the water does not contain detergent, the detergent is supplied.

[0022] The effects and significance of the present invention will become more apparent from the following description of the embodiments, however, the following embodiment is merely an example of how the present invention can be put into practice, and the present invention is not limited to the following embodiment. [Brief explanation of the drawings]

[0023] [Figure 1] FIG. 1 is a side cross-sectional view showing the configuration of a drum-type washing machine according to an embodiment. [Figure 2] FIG. 2 is a block diagram showing a configuration of a drum type washing machine according to an embodiment. [Figure 3] FIG. 3 is a flowchart showing a washing operation executed by the control unit according to the embodiment. [Figure 4] FIG. 4 is a flowchart showing a first water supply process that is performed in the washing step when there is no water in the washing tub at the start of a washing operation according to an embodiment. [Figure 5] FIG. 5 is a flowchart showing a detergent-added information storage process for storing information on whether detergent has been added in the storage unit according to the embodiment. [Figure 6] FIG. 6 is a flowchart showing the second water supply process that is performed in the washing step when water is stored in the washing tub at the start of a washing operation according to an embodiment. [Figure 7] FIG. 7 is a flowchart showing the third water supply process that is performed in the rinsing step when water is stored in the washing tub when the washing operation starts from the rinsing step according to the embodiment. [Figure 8] FIG. 8 is a flowchart showing the second water supply process according to the first modified example, which is carried out in the washing step when water is stored in the washing tub at the start of the washing operation. DETAILED DESCRIPTION OF THE INVENTION

[0024] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A drum-type washing machine, which is one embodiment of the washing machine of the present invention, will be described below with reference to the drawings.

[0025] FIG. 1 is a side cross-sectional view showing the configuration of a drum-type washing machine 1. As shown in FIG.

[0026] The drum type washing machine 1 has a rectangular housing 10. A circular loading opening 11 through which laundry is loaded is formed on the front of the housing 10. The loading opening 11 is covered by a door 12 that can be opened and closed.

[0027] An outer tub 20 is disposed within the housing 10. The outer tub 20 is elastically supported by a plurality of dampers 21 and springs 22. A horizontal-axis drum 23, which is an inner tub, is disposed within the outer tub 20 so as to be freely rotatable. The drum 23 rotates around a horizontal axis. The drum 23 has a circular opening 23a on its front surface. The drum 23 may rotate around an inclined axis that is inclined relative to the horizontal direction. The outer tub 20 and the drum 23 form a washing tub W.

[0028] The outer tub 20 has a circular opening 20a in front of the opening 23a of the drum 23. The peripheral edge of the opening 20a of the outer tub 20 and the peripheral edge of the loading port 11 of the housing 10 are connected by an annular door packing 24 made of an elastic material. The peripheral surface of the closed door 12 comes into contact with the door packing 24, and the space between the loading port 11 and the door 12 is watertight.

[0029] A large number of dewatering holes 23b are formed on the inner peripheral surface of the drum 23. In addition, three baffles 25, each having a substantially triangular prism shape, are provided on the inner peripheral surface of the drum 23 at equal intervals in the circumferential direction.

[0030] A drive motor 30 is disposed behind the outer tub 20, generating torque for rotating the drum 23. The drive motor 30 is, for example, an outer rotor DC brushless motor. During the washing and rinsing cycles, the drive motor 30 rotates the drum 23 at a rotation speed at which the centrifugal force acting on the laundry inside the drum 23 is smaller than the gravity, causing the laundry to tumble. On the other hand, during the spin cycle, the drive motor 30 rotates the drum 23 at a rotation speed at which the centrifugal force acting on the laundry inside the drum 23 is much larger than the gravity, causing the laundry to stick to the inner circumferential surface of the drum 23.

[0031] A drain outlet 20b is formed at the bottom of the outer tub 20. A drain unit 40, which drains water from the outer tub 20, is connected to the drain outlet 20b. The drain unit 40 is composed of a drain valve 41, a drain hose 42, and a drain filter 43. The drain filter 43 is connected to the drain outlet 20b. The drain valve 41 is provided downstream of the drain filter 43 and includes, for example, a valve and a torque motor for opening and closing the valve. The drain hose 42 is connected to the drain valve 41. When the drain valve 41 is opened, water stored in the outer tub 20 is discharged outside the machine through the drain outlet 20b, the drain filter 43, and the drain hose 42. Foreign matter such as lint is captured by the drain filter 43.

[0032] A water supply device 50 is disposed at the upper part of the housing 10. The water supply device 50 supplies water into the outer tub 20. The water supply device 50 also functions as an automatic detergent dispenser, and automatically dispenses liquid detergent and liquid fabric softener into the outer tub 20, i.e., the washing tub W.

[0033] The water supply device 50 includes a water supply valve unit 51, a water injection unit 52, and a nozzle unit 53.

[0034] The water supply valve unit 51 includes a water supply valve 110, a first water supply hose 120, and a second water supply hose 130. The water supply valve 110 has a first valve 111 and a second valve 112. A water supply port 113 of the water supply valve 110 is connected to a water faucet via a connecting hose (not shown).

[0035] The inlet of the first water supply hose 120 is connected to the first valve 111, and the inlet of the second water supply hose 130 is connected to the second valve 112. When the first valve 111 is opened, water flows into the first water supply hose 120, and when the second valve 112 is opened, water flows into the second water supply hose 130.

[0036] The water injection unit 52 includes a water injection port member 140 that opens at the front, a liquid agent tank section 150 that is accommodated in the water injection port member 140 so that it can be pulled out, a water channel forming member 160 that is arranged on the upper surface of the water injection port member 140, and a pump unit 170 that is arranged on the rear surface of the water injection port member 140.

[0037] A water inlet 141 is formed at the bottom of the water inlet member 140. A water inlet pipe 54 extending from the water inlet 141 is connected to the outer tub 20.

[0038] The liquid agent tank section 150 has a detergent tank 151 in which a liquid detergent is stored and a fabric softener tank 152 in which a liquid fabric softener is stored. The liquid agent tank section 150 is accommodated in the water inlet member 140 through an accommodation opening 13 provided on the front surface of the housing 10. A lid 153 that closes the accommodation opening 13 is provided on the front surface of the liquid agent tank section 150.

[0039] Inside the water channel forming member 160, a first water channel to which the outlet of the first water supply hose 120 is connected and a second water channel to which the outlet of the second water supply hose 130 is connected are formed.

[0040] The pump unit 170 includes a detergent pump 171 that supplies the liquid detergent in the detergent tank 151 into the first water passage, and a fabric softener pump 172 that supplies the fabric softener in the fabric softener tank 152 into the first water passage (see FIG. 2).

[0041] Water supplied from first water supply hose 120 to water channel forming member 160 flows through the first water channel, is discharged to the bottom of water inlet member 140, and is supplied into outer tub 20, i.e., washing tub W, via water inlet 141 and water inlet pipe 54. Water inlet pipe 54 is a first water supply path that supplies water directly into outer tub 20 without passing through drum 23. Therefore, the supplied water is less likely to contain dirt adhering to the laundry in drum 23.

[0042] When liquid detergent or liquid fabric softener is automatically dispensed into the outer tub 20, the liquid detergent or liquid fabric softener is introduced into the first water passage from the liquid agent tank 150 by the pump unit 170 before the first valve 111 is opened. The liquid detergent or liquid fabric softener is mixed with water flowing through the first water passage and supplied into the outer tub 20.

[0043] Water supplied from the second water supply hose 130 to the water channel forming member 160 flows through the second water channel and is sent to the nozzle unit 53.

[0044] Nozzle unit 53 includes a shower nozzle 180 arranged inside the upper part of door gasket 24, and a water supply hose 181 extending from the second water channel of water channel forming member 160 and connected to shower nozzle 180.

[0045] The water outlet of shower nozzle 180 faces downward and rearward, i.e., toward the bottom of drum 23. Water flowing out from the second water passage passes through water supply hose 181 to shower nozzle 180, and is then sprayed in a shower-like manner from the outlet of shower nozzle 180 into drum 23. This causes water to splash on the laundry inside drum 23, making it easier for the water to penetrate into the laundry. Shower nozzle 180 is a second water supply path through which water is supplied into outer tub 20 via drum 23.

[0046] A conductivity detection unit 60 is disposed at the bottom of the outer tub 20. The conductivity detection unit 60 includes, for example, a pair of electrodes, and detects the conductivity of the water stored in the outer tub 20. The higher the concentration of detergent contained in the water in the outer tub 20, the higher the detected conductivity. When the water in the outer tub 20 contains detergent, the conductivity detection unit 60 detects the conductivity according to the detergent concentration, and when the water in the outer tub 20 does not contain detergent, it detects the conductivity of the water itself.

[0047] FIG. 2 is a block diagram showing the configuration of the drum type washing machine 1. As shown in FIG.

[0048] In addition to the above-described configuration, the drum type washing machine 1 includes a control unit 201, a memory unit 202, an operation unit 203, a display unit 204, a sound output unit 205, a water level detection unit 206, a motor drive unit 207, a water supply drive unit 208, a drain drive unit 209, and a pump drive unit 210.

[0049] The operation unit 203 includes a power button for turning the power on and off, a course selection button for selecting an operation course from a plurality of operation courses related to the washing operation, and a start button for starting and pausing the washing operation. The operation unit 203 outputs an input signal to the control unit 201 according to the button operated by the user.

[0050] Display unit 204 includes a display such as a light-emitting element such as an LED or a liquid crystal panel, and displays the selected operation course, the progress of the washing operation, notifies of abnormalities, displays the amount of detergent added, etc., in accordance with a control signal from control unit 201. Sound output unit 205 includes a speaker, and outputs sounds such as voice and alarm sounds from the speaker. Note that operation unit 203 and display unit 204 may be configured as an operation display unit such as a touch panel.

[0051] The water level detection unit 206 detects the water level in the outer tub 20, i.e., the washing tub W, and outputs a water level signal corresponding to the water level to the control unit 201. The conductivity detection unit 60 detects the conductivity of the water in the outer tub 20, i.e., the washing tub W, and outputs a detection signal corresponding to the conductivity to the control unit 201.

[0052] The motor drive unit 207 drives the drive motor 30 in accordance with a control signal from the control unit 201. The motor drive unit 207 includes a rotation sensor that detects the rotation speed of the drive motor 30, an inverter circuit, etc., and adjusts the drive power so that the drive motor 30 rotates at the rotation speed set by the control unit 201. Furthermore, the motor drive unit 207 includes a current sensor that detects the current flowing through the drive motor 30.

[0053] The water supply driving unit 208 drives the first valve 111 and the second valve 112 of the water supply valve 110 in accordance with a control signal from the control unit 201. The drain driving unit 209 drives the drain valve 41 in accordance with a control signal from the control unit 201. The pump driving unit 210 drives the detergent pump 171 and the fabric softener pump 172 of the pump unit 170 in accordance with a control signal from the control unit 201.

[0054] The storage unit 202 includes an EEPROM, a RAM, etc. Programs for executing various operation courses of the washing operation are stored in the storage unit 202. The storage unit 202 also stores various parameters and various control flags used in executing these programs.

[0055] The control unit 201 includes a CPU and the like, and controls the display unit 204, sound output unit 205, motor drive unit 207, water supply drive unit 208, drainage drive unit 209, pump drive unit 210, etc., based on signals from the operation unit 203, water level detection unit 206, conductivity detection unit 60, etc., in accordance with a program stored in the memory unit 202.

[0056] In the drum type washing machine 1, various operation courses are performed under the control of the control unit 201 based on the user's operation of the operation unit 203. In the washing operation, a washing step, an intermediate spin-drying step, a rinsing step, and a final spin-drying step are performed in this order. Depending on the operation course, the rinsing step and the intermediate spin-drying step may be performed two or more times.

[0057] In the washing process, water containing detergent is filled in the outer tub 20 up to a predetermined washing water level, and laundry immersed in the water is tumbled by repeatedly rotating the drum 23 forward and backward. The detergent-containing water penetrates deep into the laundry, and the power of the detergent and the mechanical force of the tumbling remove dirt adhering to the surface and interior of the laundry.

[0058] In the rinsing process, the drum 23 rotates repeatedly in both forward and reverse directions while the outer tub 20 is filled with water up to a predetermined rinse level, tumbling the laundry. This causes the detergent contained in the laundry to be expelled along with the water, rinsing the laundry.

[0059] When supplying water during the washing and rinsing steps, the water supply device 50 supplies water into the outer tub 20 through the water inlet member 140 and the shower nozzle 180 .

[0060] In the drum type washing machine 1 of this embodiment, a predetermined setting operation is performed on the operation unit 203 to set the water supply unit 50, which also functions as an automatic detergent dispenser, to automatically dispense liquid detergent and liquid fabric softener, i.e., the automatic dispense setting can be switched on and off. When the automatic dispense setting is on, the water supply unit 50 automatically dispenses liquid detergent from the detergent tank 151 along with water supply during the washing process, and the water supply unit 50 automatically dispenses liquid fabric softener from the fabric softener tank 152 along with water supply during the rinsing process. When the rinsing process is performed two or more times, the liquid fabric softener is dispensed during the final rinsing process. When the automatic dispense setting is off, the water supply unit 50 does not automatically dispense liquid detergent and liquid fabric softener, and the display unit 204 displays the amounts of detergent and fabric softener dispensed.

[0061] If there is no water stored in the washing tub W at the start of the washing operation, the control unit 201 executes a first water supply process (described later) during the washing process to store water in the washing tub W. On the other hand, if there is water stored in the washing tub W at the start of the washing operation, the control unit 201 executes a second water supply process (described later) during the washing process to store water in the washing tub W.

[0062] In the intermediate spin-drying step and the final spin-drying step, drive motor 30 rotates in one direction at high speed, causing drum 23 to rotate in one direction at a rotation speed at which the centrifugal force acting on the laundry inside drum 23 is much greater than gravity. The centrifugal force presses the laundry against the inner circumferential surface of drum 23, causing it to be dewatered. In the final spin-drying step, drum 23 rotates at a rotation speed higher than that in the intermediate spin-drying step.

[0063] FIG. 3 is a flowchart showing the washing operation executed by the control unit 201.

[0064] When the washing operation starts, control unit 201 determines whether water is stored in outer tub 20, i.e., washing tub W, based on the detection result of water level detection unit 206 (S11). For example, control unit 201 determines that water is stored in washing tub W when water level detection unit 206 detects a water level higher than a specified water level. The specified water level is set to, for example, a water level lower than the wash water level.

[0065] When the control unit 201 determines that there is no water in the washing tub W (S11: NO), it detects the laundry load (S12). For example, the control unit 201 rotates the drum 23 by the drive motor 30 at a rotation speed that tumbles the laundry in the drum 23, and detects the load applied to the drum 23 during rotation from the value of the current flowing through the drive motor 30. The greater the laundry load, the greater the load applied to the drum 23, and the greater the value of the current flowing through the drive motor 30. The control unit 201 determines the load based on the magnitude of the current value. Then, based on the load, the control unit 201 determines the amount of detergent to be dispensed in the wash cycle and the amount of fabric softener to be dispensed in the rinse cycle (S13). The greater the load, the greater the amount to be dispensed.

[0066] Thereafter, the control unit 201 executes the washing process including the first water supply process (S14).

[0067] If the power is turned off during the washing or rinsing process due to a power outage or user operation, and then the power is turned on again and the washing operation is started from the beginning by the start operation, or if the user pours leftover bath water or the like into the washing tub W and then turns the power on and starts the washing operation by the start operation, water may already be stored in the washing tub W when the washing operation begins.

[0068] In S11, when the control unit 201 determines that water is stored in the washing tub W (S11: YES), the control unit 201 executes the washing process including the second water supply process (S15).

[0069] When the washing step is completed, the control unit 201 executes the intermediate spin-drying step, the rinsing step, and the final spin-drying step in this order (S16 to S18), thus completing the washing operation.

[0070] FIG. 4 is a flowchart showing the first water supply process that is carried out in the washing step when there is no water stored in the washing tub W at the start of the washing operation.

[0071] When the washing process is started with no water stored in the washing tub W, the control unit 201 determines whether the automatic water dispensing setting is on or off (S101). If the automatic water dispensing setting is on (S101: YES), the control unit 201 determines whether the reference conductivity has already been acquired and stored in the memory unit 202 (S102). The reference conductivity is the conductivity of water that does not contain detergent.

[0072] If the reference conductivity has not yet been acquired (S102: NO), control unit 201 opens first valve 111 (S103). Water is supplied from water supply pipe 54 of water supply device 50 without passing through drum 23, and water accumulates in washing tub W. When the water level in washing tub W reaches a predetermined detection water level (S104: YES), control unit 201 closes first valve 111 (S105). The detection water level is set to be lower than the bottom of drum 23 and to a level at which laundry in drum 23 is not submerged. In this way, by supplying water to outer tub 20 without passing through drum 23 and preventing laundry in drum 23 from being submerged in water, dirt adhering to the laundry is less likely to be contained in the water accumulated in washing tub W.

[0073] Control unit 201 causes conductivity detection unit 60 to detect the conductivity of the water stored in washing tub W as a reference conductivity, and stores the reference conductivity in memory unit 202 (S106). At this time, since the reference conductivity is less affected by dirt attached to the laundry, it is possible to detect the reference conductivity with high accuracy.

[0074] Next, the control unit 201 operates the detergent pump 171 (S107). The detergent pump 171 operates for a supply time during which the amount of detergent determined based on the load amount is supplied into the first water channel of the water channel forming member 160. Note that if the reference conductivity has been acquired (S102: YES), the control unit 201 immediately operates the detergent pump 171 (S107) without detecting the reference conductivity.

[0075] Thereafter, control unit 201 opens first valve 111 and second valve 112 (S108). Water is supplied into washing tub W from both water supply pipe 54 and shower nozzle 180. At this time, the detergent in the first water channel is washed away by the water and poured into washing tub W. When the water level in washing tub W reaches the wash water level (S109: YES), control unit 201 closes first valve 111 and second valve 112 (S110). Water supply stops, and water supply into washing tub W, including automatic detergent addition, is completed.

[0076] If the control unit 201 determines in S101 that the automatic dispensing setting is off (S101: NO), it causes the display unit 204 to display the amount of detergent to be dispensed (S111). The amount to be dispensed at this time is the amount determined based on the load amount in S13 of FIG. 3. The display of the amount to be dispensed can be, for example, a numerical indication of the approximate amount to be dispensed, or an illustration of the approximate amount to be dispensed. Thereafter, the control unit 201 waits for a predetermined waiting time to elapse in order to wait for the user to dispense detergent (S112).

[0077] The user opens the door 12 and pours the recommended amount of detergent into the drum 23. The detergent is usually poured onto the laundry contained in the drum 23, but does not reach the outside of the drum 23, i.e., the bottom of the outer tub 20.

[0078] When the standby time has elapsed (S112: YES), control unit 201 opens first valve 111 (S113). Water is supplied from water injection pipe 54 into outer tub 20 without passing through drum 23. When the water level in washing tub W reaches the detection water level (S114: YES), control unit 201 causes conductivity detection unit 60 to detect the conductivity of the water stored in washing tub W as a reference conductivity, and stores it in memory unit 202 (S115). If the reference conductivity has already been stored in memory unit 202, the reference conductivity is updated.

[0079] By supplying water into outer tub 20 without passing through drum 23 and preventing the laundry in drum 23 from being submerged in water, the water stored in washing tub W is less likely to contain dirt adhering to the laundry or detergent added to drum 23. This allows for highly accurate detection of the reference conductivity.

[0080] Thereafter, control unit 201 opens second valve 112 (S116). Then, when the water level in washing tub W reaches the wash water level (S109: YES), control unit 201 closes first valve 111 and second valve 112 (S110). Water supply stops, and water supply into washing tub W, including manual detergent addition by the user, is completed.

[0081] Note that control unit 201 may stop first valve 111 and detect the reference conductivity when the water level in washing tub W reaches the detection water level. In this case, control unit 201 opens first valve 111 and second valve 112 when detection of the reference conductivity is completed.

[0082] Furthermore, in the process of S115, if the detected reference conductivity is greater than the reference conductivity stored in the memory unit 202, the reference conductivity may not be updated. This is to prevent the reference conductivity from being stored in a case where the reference conductivity becomes greater due to detergent poured into the drum 23 leaking out of the drum 23 to the bottom of the outer tub 20.

[0083] Furthermore, when the automatic input setting is on, the reference conductivity may be detected every time or at predetermined intervals, not just when the reference conductivity is not obtained, and the reference conductivity in the memory unit 202 may be updated to a new value.

[0084] When the automatic detergent dispensing setting is in the on state, control unit 201 executes a detergent-added information storage process. The detergent-added information storage process is a process for storing detergent-added information, which indicates that water containing detergent dispensed from water supply device 50, which is an automatic detergent dispenser, is stored in washing tub W, in storage unit 202. The detergent-added information is used in the second water supply process.

[0085] FIG. 5 is a flowchart showing the detergent dispensed information storage process.

[0086] When the water supply device 50 automatically dispenses detergent into the washing tub W (S201: YES), the control unit 201 sets a detergent dispensed flag (S202). The detergent dispensed flag is provided in the memory unit 202. Setting the detergent dispensed flag means that information indicating that the detergent has been dispensed is stored in the memory unit 202.

[0087] Thereafter, when the washing step is completed (S203: YES), the control unit 201 resets the detergent-added flag (S204). Resetting the detergent-added flag means that the detergent-added information is erased from the storage unit 202.

[0088] If the power is turned off and the washing operation is stopped after detergent is added to the washing tub W but before the washing cycle is completed, the detergent added flag remains set. Therefore, when the washing operation is restarted from the beginning, the detergent added flag remains set.

[0089] FIG. 6 is a flowchart showing the second water supply process that is carried out in the washing step when water is stored in the washing tub W at the start of the washing operation.

[0090] When the washing process is started with water stored in the washing tub W, the control unit 201 determines whether the automatic dispensing setting is on or off (S301). If the automatic dispensing setting is on (S301: YES), the control unit 201 determines whether the detergent dispensed flag is set (S302).

[0091] If the water in the washing tub W does not contain the detergent that was automatically added in the washing step of the previous washing operation, the detergent addition flag is reset. In this case, detergent needs to be added to the washing tub W.

[0092] If the detergent dispensed flag is reset (S302: NO), the control unit 201 operates the detergent pump 171 for the dispense time (S303). As a result, the dispensed amount of detergent determined based on the load amount is supplied into the first water channel of the water channel forming member 160.

[0093] Thereafter, the control unit 201 opens the first valve 111 and the second valve 112 (S304), which causes the water supply device 50 to supply water into the washing tub W and automatically dispense the detergent.

[0094] On the other hand, if the water in the washing tub W contains detergent that was automatically added during the washing process of the previous washing operation, the detergent added flag is set. In this case, there is no need to add detergent to the washing tub W.

[0095] If the detergent-added flag is set (S302: YES), control unit 201 immediately opens first valve 111 and second valve 112 (S304). As a result, water supply device 50 supplies water into washing tub W without automatically adding detergent.

[0096] Thereafter, when the water level in washing tub W reaches the wash water level (S305: YES), control unit 201 closes first valve 111 and second valve 112 (S306). Water supply stops, and the supply of water into washing tub W is completed.

[0097] In addition, if water has already accumulated in the washing tub W up to the wash water level when the control unit 201 opens the first valve 111 and the second valve 112 in S304, the control unit 201 supplies water from the water supply device 50 for a period of time that allows detergent to be automatically dispensed into the washing tub W, and then closes the first valve 111 and the second valve 112.

[0098] At S301, when control unit 201 determines that the automatic dispensing setting is off (S301: NO), control unit 201 detects the conductivity of the water stored in washing tub W using conductivity detection unit 60 (S307). Then, control unit 201 calculates the difference between the detected conductivity and the reference conductivity (S308). The difference can be, for example, a difference value obtained by subtracting the reference conductivity from the detected conductivity, or a ratio value obtained by dividing the detected conductivity by the reference conductivity.

[0099] If the water stored in the washing tub W does not contain detergent, the detected conductivity will be approximately equal to the reference conductivity, and the difference will be equal to or less than the threshold. If the water stored in the washing tub W does not contain detergent, the detected conductivity will be greater than the reference conductivity, and the difference will be greater than the threshold.

[0100] If the difference is equal to or less than the threshold (S309: NO), control unit 201 determines that the water in washing tub W does not contain detergent and causes display unit 204 to display the amount of detergent to be dispensed (S310). If water is stored in washing tub W at the start of a wash cycle, the load amount detection in S12 of FIG. 3 and the dispense amount determination based on the load amount in S13 are not performed. Therefore, the dispense amount at this time is a dispense amount that is preset as the dispense amount when the load amount is not detected, such as a dispense amount corresponding to the rated load amount. Control unit 201 then waits for a standby time to elapse (S311). During the standby time, detergent is dispensed into drum 23, i.e., washing tub W. The process of causing display unit 204 to display the amount of detergent to be dispensed in S310 and the process of waiting for the standby time to elapse in S311 are detergent supply processes for supplying detergent into washing tub W.

[0101] When the standby time has elapsed (S311: YES), the control unit 201 opens the first valve 111 and the second valve 112 (S304), thereby starting the supply of water into the washing tub W.

[0102] On the other hand, if the difference is greater than the threshold value (S309: YES), the control unit 201 determines that the water in the washing tub W contains detergent, and opens the first valve 111 and the second valve 112 without displaying the amount of detergent added on the display unit 204, i.e., without performing the detergent supply process (S304).

[0103] When the water level in washing tub W reaches the wash water level (S305: YES), control unit 201 closes first valve 111 and second valve 112 (S306). Water supply stops, and the supply of water into washing tub W is completed.

[0104] Note that if water has already accumulated in washing tub W up to the wash water level before first valve 111 and second valve 112 are opened in S304, control unit 201 does not open first valve 111 and second valve 112.

[0105] FIG. 7 is a flowchart showing the third water supply process that is carried out in the rinsing step when water is stored in the washing tub when the washing operation starts from the rinsing step.

[0106] Depending on the operation course, the operation contents can be changed so that the washing process and intermediate spin-drying process are eliminated and a rinsing process and final spin-drying process are performed. In this case, the washing operation starts from the rinsing process. When the washing operation starts from the rinsing process, if water is already stored in the washing tub W at the start of the operation, the rinsing process is executed in which water is supplied into the washing tub W by the third water supply process.

[0107] 7, the control unit 201 determines whether the automatic dispensing setting is on or off (S401). If the automatic dispensing setting is on (S401: YES), the control unit 201 determines whether the detergent dispensing flag is set (S402).

[0108] If the water in the washing tub W contains detergent that was automatically added during the washing process of the previous washing operation, the detergent-added flag is set. In this case, the laundry in the washing tub W cannot be rinsed well with water containing detergent.

[0109] If the detergent-added flag is set (S402: YES), control unit 201 opens drain valve 41 (S403). This starts draining water from washing tub W. When draining water from washing tub W is completed (S404: YES), control unit 201 closes drain valve 41 (S405). For example, control unit 201 determines that draining is completed when a predetermined time has elapsed since water level detection unit 206 detected the lowest detectable water level.

[0110] On the other hand, if the water in the washing tub W does not contain the detergent that was automatically added in the washing step of the previous washing operation, the detergent-added flag is reset. In this case, rinsing can be performed satisfactorily with the water in the washing tub W. Therefore, if the detergent-added flag is reset (S402: NO), the control unit 201 does not perform the drainage-related processes of S403 to S405.

[0111] Next, control unit 201 operates fabric softener pump 172 for the dispensing time (S406). As a result, the detergent amount determined based on the load amount is supplied into the first water channel of water channel forming member 160. Thereafter, control unit 201 opens first valve 111 and second valve 112 (S407). As a result, water supply device 50 supplies water into washing tub W and automatically dispenses fabric softener.

[0112] When the water level in washing tub W reaches the rinse water level (S408: YES), control unit 201 closes first valve 111 and second valve 112 (S409). Water supply stops, and water supply into washing tub W is completed.

[0113] In addition, if water has already accumulated in the washing tub W up to the rinse level when the control unit 201 opens the first valve 111 and the second valve 112 in S407, the control unit 201 supplies water from the water supply device 50 into the washing tub W for a period of time that allows fabric softener to be automatically dispensed, and then closes the first valve 111 and the second valve 112.

[0114] Furthermore, if the rinsing cycle is performed multiple times, fabric softener is not dispensed in the first rinsing cycle, and therefore the control unit 201 does not perform the process of operating the fabric softener pump 172 in S406.

[0115] At S401, when the control unit 201 determines that the automatic dispensing setting is off (S401: NO), the control unit 201 detects the conductivity of the water stored in the washing tub W by the conductivity detection unit 60 (S410). Then, the control unit 201 calculates the difference between the detected conductivity and the reference conductivity (S411).

[0116] If the difference is greater than the threshold value (S412: YES), control unit 201 determines that the water in washing tub W contains detergent, and opens drain valve 41 to drain water from washing tub W (S403 to S405).

[0117] On the other hand, if the difference is less than or equal to the threshold value (S412: NO), the control unit 201 determines that the water in the washing tub W does not contain detergent, and opens the first valve 111 and the second valve 112 to supply water into the washing tub W without draining the water from the washing tub W (S407 to S409).

[0118] Note that if water has already accumulated in washing tub W up to the rinse level before first valve 111 and second valve 112 are opened in S407, control unit 201 does not open first valve 111 and second valve 112.

[0119] The drum type washing machine 1 of this embodiment may be provided with a drying device for drying laundry. In this case, the drying device includes, for example, a circulation path connected to the outer tub 20. A blower fan, a cooler, and a heater are arranged in the circulation path. Air heated by the heater circulates between the outer tub 20 and the circulation path by operation of the blower fan, and the laundry in the drum 23 dries. The air returning to the circulation path from the outer tub 20 is cooled and dehumidified by the cooler before being heated by the heater.

[0120] <Effects of the embodiment> According to this embodiment, when control unit 201 determines that water is stored in washing tub W based on the detection result by water level detection unit 206 when the washing operation is started, it causes conductivity detection unit 60 to detect the conductivity of the water in washing tub W and determines whether or not the water in washing tub W contains detergent based on the detection result of the conductivity. If control unit 201 determines that the water in washing tub W does not contain detergent, it causes display unit 204 to display the amount of detergent added as a detergent supply process for supplying detergent into washing tub W in the washing process, and if control unit 201 determines that the water in washing tub W contains detergent, it does not cause display unit 204 to display the amount of detergent added in the washing process.

[0121] According to this configuration, when water is stored in the washing tub W at the start of a washing operation, if the water contains detergent, the detergent is not supplied, and if the water does not contain detergent, the detergent is supplied.

[0122] Furthermore, according to the present embodiment, when control unit 201 determines that water is stored in washing tub W at the start of a washing operation and the automatic dispensing setting is on, if control unit 201 determines that the water in washing tub W does not contain detergent based on the fact that information indicating that detergent has been added being not stored in memory unit 202, it causes water supply device 50 to automatically dispense detergent in the washing process, and when control unit 201 determines that the water in washing tub W contains detergent based on the fact that information indicating that detergent has been added being stored in memory unit 202, it does not cause water supply device 50 to automatically dispense detergent in the washing process. On the other hand, when control unit 201 determines that water is stored in washing tub W at the start of a washing operation and the automatic dispensing setting is off, it causes display unit 204 to display the amount of detergent dispensed if it determines that the water in washing tub W does not contain detergent based on the detection result of the conductivity of the water in washing tub W by conductivity detection unit 60, and it does not cause display unit 204 to display the amount of detergent dispensed if it determines that the water in washing tub W contains detergent based on the detection result of the conductivity.

[0123] According to this configuration, when the automatic dispensing setting is on and information that detergent has been added is available, it is determined whether the water in washing tub W contains detergent based on whether the information that detergent has been added is stored, so that it is possible to quickly determine whether detergent is present without taking time to detect the conductivity of the water in washing tub W. Then, when detergent is not present in the water in washing tub W, detergent can be automatically dispensed into washing tub W from water supply device 50, which is an automatic detergent dispensing device.

[0124] Furthermore, when the automatic dispensing setting is off and information on whether detergent has been dispensed is unavailable, it is determined whether the water in washing tub W contains detergent based on the detection result of conductivity, so that it is possible to determine whether detergent is present even when detergent is not automatically dispensed by water supply device 50. When detergent is not present in the water in washing tub W, display unit 204 displays the amount of detergent to be dispensed, prompting the user to dispense detergent.

[0125] Furthermore, according to this embodiment, the control unit 201 detects the conductivity of the water in the washing tub W that does not contain detergent using the conductivity detection unit 60 as a reference conductivity, and determines that the water in the washing tub W contains detergent if the difference between the conductivity detected at the start of the washing operation and the reference conductivity is greater than a threshold value.

[0126] According to this configuration, even if the conductivity of the water supplied from the faucet to the drum type washing machine 1 varies depending on the region, season, etc., it is possible to accurately determine whether the water in the washing tub W contains detergent.

[0127] Furthermore, according to this embodiment, when the washing operation starts from the rinsing step, if control unit 201 determines that the water in washing tub W contains detergent, it causes drainage unit 40 to drain water from washing tub W and then causes water supply device 50 to supply water into washing tub W in the rinsing step, and if control unit 201 determines that the water in washing tub W does not contain detergent, it causes water supply device 50 to supply water into washing tub W in the rinsing step without draining water from washing tub W.

[0128] This configuration can prevent the laundry from being rinsed properly when rinsed with water containing detergent.

[0129] Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications to the embodiments of the present invention are possible.

[0130] <Change example 1> FIG. 8 is a flowchart showing the second water supply process according to the first modified example, which is carried out in the washing step when water is stored in the washing tub W at the start of the washing operation.

[0131] In this modified example, when water is stored in the washing tub W at the start of the washing operation, the control unit 201 determines whether the water contains detergent based on the conductivity of the water in the washing tub W, regardless of whether the automatic dispensing setting is on or off.

[0132] 8, control unit 201 detects the conductivity of the water in washing tub W (S501), and calculates the difference between the detected conductivity and a reference conductivity (S502). If control unit 201 determines that the difference is equal to or less than the threshold value and that the water in washing tub W does not contain detergent (S503: NO), control unit 201 determines whether the automatic detergent dispensing setting is on or off (S504).

[0133] If the automatic dispensing setting is on (S504: YES), control unit 201 operates detergent pump 171 for the dispensing time and then opens first valve 111 and second valve 112 (S505, S506), and causes water supply device 50, which is an automatic detergent dispenser, to automatically dispense detergent as a detergent supply process. Then, control unit 201 keeps first valve 111 and second valve 112 open until the water level in washing tub W reaches the wash water level, and supplies water into washing tub W (S507, S508).

[0134] On the other hand, if the automatic dispensing setting is off (S504: NO), control unit 201 causes display unit 204 to display the amount of detergent dispensed as a detergent supply process (S509). Then, when the standby time has elapsed (S510: YES), control unit 201 opens first valve 111 and second valve 112 to supply water into washing tub W up to the wash water level (S506 to S508).

[0135] In S503, if the control unit 201 determines that the difference is greater than the threshold value and that the water in the washing tub W contains detergent (S503: YES), it immediately opens the first valve 111 and the second valve 112 and supplies water into the washing tub W up to the wash water level (S506 to S508).

[0136] In this modification, the detergent dispensed information storage process of FIG. 5 is not executed.

[0137] In this modified example, as in the above embodiment, when water is stored in the washing tub W at the start of the washing operation, if the water contains detergent, detergent will not be supplied, and if the water does not contain detergent, detergent will be supplied.

[0138] <Other change examples> In the above embodiment, the water supply device 50 is configured to function as the automatic detergent dispenser. However, the automatic detergent dispenser may be provided separately from the water supply device 50. In this case, the automatic detergent dispenser may be configured to dispense liquid detergent and liquid fabric softener directly into the washing tub W from the detergent tank and fabric softener tank.

[0139] Furthermore, a storage section for storing a single dose of detergent such as powder detergent may be provided in liquid agent tank section 150 of water supply device 50. In this case, a third valve and a third water passage may be provided in water supply device 50, and a configuration may be adopted in which water from the third valve passes through the third water passage and the storage section and is discharged to the bottom of water inlet member 140. When the automatic dispensing setting is off, detergent is dispensed into the storage section, and the third valve is opened together with second valve 112.

[0140] Furthermore, the automatic detergent dispenser may be configured to automatically dispense only liquid detergent and not liquid fabric softener.

[0141] Furthermore, the drum type washing machine 1 may be configured so that the water supply device 50 does not have the function of an automatic detergent dispenser, i.e., the automatic detergent dispenser is not provided. If the automatic detergent dispenser is not provided, the determination of whether the water in the washing tub W contains detergent is made only based on the result of the conductivity detection by the conductivity detection unit 60.

[0142] Furthermore, in the above embodiment, a drum type washing machine 1 has been described. However, the present invention can also be applied to washing machines other than the drum type washing machine 1, for example, a fully automatic washing machine having a vertical axis type washing and spin-drying tub as an inner tub inside an outer tub. The fully automatic washing machine may be a fully automatic washer-dryer having a drying function.

[0143] In addition, the embodiments of the present invention can be modified in various ways as appropriate within the scope of the technical ideas set forth in the claims. [Explanation of symbols]

[0144] 1. Drum washing machine 20 Outer tank 23 Drum (inner tank) W Washing tub 40 Drainage section 50 Water supply device (automatic detergent dispenser) 60 Conductivity detector 151 Detergent tank 201 Control Unit 202 Storage section 204 Display section 206 Water level detection unit

Claims

1. a washing tub including an outer tub for storing water and an inner tub disposed within the outer tub for storing laundry; a water supply device for supplying water into the washing tub; a water level detection unit that detects the water level in the washing tub; a conductivity detection unit that detects the conductivity of water stored in the washing tub; a control unit that executes a washing operation including a washing step, a rinsing step, and a spin-drying step; The control unit When the washing operation is started, it is determined whether water is stored in the washing tub based on the detection result by the water level detection unit, When it is determined that water is stored in the washing tub, the conductivity detection unit detects the conductivity, and determines whether the water in the washing tub contains detergent based on the detection result of the conductivity. When it is determined that the water in the washing tub does not contain detergent, a detergent supply process is performed to supply detergent into the washing tub in the washing step. When it is determined that the water in the washing tub contains detergent, the detergent supply process is not performed in the washing step. A washing machine characterized by:

2. The washing machine according to claim 1, Further comprising a display unit, The detergent supply process includes a process in which the control unit causes the display unit to display an amount of detergent dispensed. A washing machine characterized by:

3. The washing machine according to claim 1, The washing machine further includes an automatic detergent dispenser having a detergent tank for storing detergent and automatically dispensing the detergent in the detergent tank into the washing tub, The detergent supply process includes a process in which the control unit operates the automatic detergent dispenser. A washing machine characterized by:

4. The washing machine according to claim 1, A display unit; an automatic detergent dispenser having a detergent tank for storing detergent and automatically dispensing the detergent in the detergent tank into the washing tub; a storage unit, A setting as to whether or not the automatic detergent dispenser automatically dispenses detergent can be turned on and off, The memory unit stores detergent-added information indicating that water containing detergent added from the automatic detergent dispenser is stored in the washing tub, The control unit When it is determined that water is stored in the washing tub at the start of the washing operation, if the automatic water supply setting is on, When it is determined that the water in the washing tub does not contain detergent based on the fact that the detergent-added information is not stored in the memory unit, the automatic detergent dispenser is caused to automatically dispense the detergent in the washing process; When it is determined that the water in the washing tub contains detergent based on the fact that the detergent-added information is stored in the memory unit, the automatic detergent dispenser is not caused to automatically dispense the detergent in the washing process, When it is determined that water is stored in the washing tub at the start of the washing operation, if the automatic water supply setting is off, When it is determined that the water in the washing tub does not contain detergent based on the detection result of the conductivity by the conductivity detection unit, as the detergent supply process, the display unit is caused to display an amount of detergent to be added; When it is determined that the water in the washing tub contains detergent based on the detection result of the conductivity by the conductivity detection unit, the display unit is not caused to display information regarding the amount of detergent to be added. A washing machine characterized by:

5. The washing machine according to any one of claims 1 to 4, The control unit The conductivity detection unit detects the conductivity of the water in the washing tub that does not contain detergent as a reference conductivity, When a difference between the conductivity detected at the start of the washing operation and the reference conductivity is greater than a threshold, it is determined that the water in the washing tub contains detergent. A washing machine characterized by:

6. The washing machine according to any one of claims 1 to 4, Further provided is a drainage unit for draining water from the washing tub, When the washing operation starts from the rinsing step, if water is stored in the washing tub, When it is determined that the water in the washing tub contains detergent, in the rinsing step, the drain unit drains water from the washing tub, and then the water supply device supplies water into the washing tub, When it is determined that the water in the washing tub does not contain detergent, in the rinsing step, water is supplied into the washing tub by the water supply device without draining the water from the washing tub. A washing machine characterized by:

Images