Patent Description:
<CIT> (hereinafter referred to as a "related art") discloses a washing machine having a rotating drum installed in a water tank and having a circulation pump for circulating water discharged from the water tank.

Meanwhile, for effective washing, it is important to spray the circulating water in an appropriate pattern through an operation control of the circulation pump in addition to physical actions such as a fall of the laundry caused by the rotation of the drum and friction between the laundry and the drum or lifter, and it is necessary to optimize a washing method according to the amount of laundry.

<CIT> discloses a method for controlling a washing machine comprising the steps of: treating laundry with water supplied with a detergent; draining the used water, rotating the inner tub at high speed, and operating a pump to drain the water discharged from the laundry; rotating the inner tub at a first speed and supplying water into the inner tub via a dispenser; stopping the water supply through the dispenser, rotating the inner tub at a second speed, and supplying water into the inner tub through an injection nozzle; stopping the water supply through the injection nozzle and alternately rotating a pulsator at a third speed in both directions; stopping the rotation of the pulsator, rotating the inner tub at a second speed, and supplying water into the inner tub through the injection nozzle; operating the pump to drain the water from an outer tub; and rotating the inner tub at high speed, and operating the pump to drain the water discharged from the laundry.

The present disclosure provides a control method of a washing machine to improve washing performance by allowing detergent water to be effectively applied to laundry.

The present disclosure also provides a control method of a washing machine in which detergent water having a high concentration may be evenly applied to laundry during soaking at an initial stage of washing.

The present disclosure also provides a control method of a washing machine to simultaneously apply heat and chemical action based on high-temperature detergent water and mechanical force based on drum rotation to laundry at an initial stage of washing.

The present disclosure also provides a control method of a washing machine that optimizes a washing method according to the amount of laundry.

The present invention provides a washing machine as defined in independent claim <NUM>, and a control method of a washing machine as defined in independent claim <NUM>.

The washing machine includes a tub for storing water, a drum rotatably provided in the tub, a driving unit rotating the drum, a water supply unit supplying water supplied from an external water source to the tub, a pump having a pump motor and pressure-feeding water discharged from the tub, a nozzle spraying the water pressure-fed by the pump into the drum, a heater heating the water in the tub, and a controller controlling the driving unit, the water supply unit, and the pump motor, and the heater.

The washing machine may further include a casing forming an exterior of the washing machine. The tub may be disposed in the casing. The casing may include a cabinet having an open front surface, a left surface, a right surface, and a rear surface.

A central axis of rotation on which the drum rotates may be disposed on a straight line passing through the rear surface of the cabinet. The drum may be rotated about a horizontal axis of rotation in the tub.

The nozzle may be provided in plurality.

The water supply unit may include a water supply pipe receiving water from an external water source, a water supply valve controlling the water supply pipe, and a dispenser accommodating a detergent. The dispenser may be connected to the water supply pipe and the tub.

The controller controls the water supply unit to supply water by a first set amount to the tub. The controller controls the driving unit so that the drum rotates at a first drum rotation speed while water is supplied. The controller, while the drum rotates at the first drum rotation speed, rotates the pump motor at a first pump rotation speed. When supplying water to the tub, the controller may rotate the drum at least once at the first drum rotation speed, may rotate the pump motor at least once at the first pump rotation speed, and may control rotation of the pump motor and rotation of the drum to be synchronized with each other. When supplying the water by the first set amount to the tub, the controller may control the water supply valve to supply the water supplied to the water supply pipe to the tub via the dispenser. When water is supplied to the tub by the first set amount, the detergent accommodated in the dispenser and water are supplied to the tub together.

The controller operates the heater in a state in which the first set amount of water is supplied to the tub. The controller controls the driving unit to rotate the drum at the second drum rotation speed, while operating the heater. The controller operates the pump motor at a second pump rotation speed while the heater is operated and the drum rotates at the second drum rotation speed. The controller may control the start of the pump motor to be synchronized with the start of rotation of the drum when the heater is operated. When the heater is operated, a ratio of a stop time of the drum to a rotation time of the drum may be greater than a ratio of a stop time of the drum to a rotation time of the drum when water is supplied to the tub.

The controller may stop the operation of the heater. The controller controls the driving unit to rotate the drum at the third drum rotation speed in a state in which the operation of the heater is stopped. The controller rotates the pump motor at the third pump rotation speed while the operation of the heater is stopped and the drum rotates at the third drum rotation speed. A ratio of a stop time of the drum to a rotation time of the drum in a state in which the heater is stopped may be smaller than a ratio of a stop time of the drum to a rotation time of the drum when the heater is operated.

The first drum rotation speed, the second drum rotation speed, and the third drum rotation speed may be the same as each other. The first, second, and third drum rotation speeds may be the speeds at which laundry located at the lowest point in the drum rises to a certain height by rotation of the drum and then falls apart from an inner surface of the drum.

The first pump rotation speed and the third pump rotation speed may be the same as each other.

The water supply unit may include a water supply pipe receiving water from an external water source, a water supply valve controlling the water supply pipe, and a dispenser accommodating a detergent and connected to the water supply pipe and the tub.

The controller may control the water supply valve to supply water supplied to the water supply pipe to the tub via the dispenser when water is supplied to the tub by the first set amount. When water is supplied to the tub by the first set amount, the detergent accommodated in the dispenser and water may be supplied to the tub together.

The controller may detect the amount of laundry put into the drum and control a rotation time of the drum based on the detected amount of laundry. When the detected amount of laundry is a first laundry amount, the controller may rotate the drum at the second drum rotation speed for a first time during operation of the heater, and when the detected amount of laundry is a second laundry amount greater than the first laundry amount, the controller may rotate the drum at the second drum rotation speed for a second drum driving time greater than the first drum driving time during the operation of the heater. When the detected amount of laundry is the first laundry amount, the controller may rotate the pump motor for a first pump driving time while the operation of the heater is stopped, and when the detected amount of amount is the second laundry amount greater than the first laundry amount, the controller may rotate the pump motor for a second pump driving time greater than the first pump driving time. The controller may control the driving unit such that a ratio of the stop time of the drum to the rotation time of the drum in a state in which the operation of the heater is stopped, when the detected amount of laundry is the second laundry amount is greater than a ratio of a stop time of the drum to a rotation time of the drum in a state in which the operation of the heater is stopped when the detected amount of the laundry is the first laundry amount.

The control method includes: (a) step of performing a first drum operation of supplying water by a first set amount together with a detergent into the tub and rotating the drum at a first drum rotation speed, while water is supplied, at least once and operating the pump at a first pump rotation speed at least once during the first drum operation; (b) step of operating a heater to heat water in the tub, performing a second drum operation of rotating the drum at the first drum rotation speed during the operation of the heater at least once, and operating the pump at a second pump rotation speed at least once during the second drum operation; and (c) step of stopping the operation of the heater, performing a third drum operation of rotating the drum at the first drum rotation speed at least once, and operating the pump at the first pump rotation speed at least once during the third drum operation.

In step (a), the operation of the pump may be controlled to be synchronized with the rotation of the drum.

In step (b), the start of the pump may be controlled to be synchronized with the start of the rotation of the drum.

While the drum is rotated at the first drum rotation speed, the laundry located at the lowest point in the drum may rise to a certain height by the rotation of the drum and then may be separated from an inner surface of the drum and fall.

The ratio of the stop time of the drum to the operation time of the drum in step (b) is greater than the ratio of the stop time of the drum to the operation time of the drum in step (a).

The ratio of the stop time of the drum to the operation time of the drum in step (c) may be smaller than the ratio of the stop time of the drum to the operation time in step (b).

First, the control method of a washing machine of the present disclosure has the effect of evenly applying the detergent water to the laundry in the drum by performing speed shifting operation on the circulation pump in the process of supplying the detergent water.

Second, since heating is performed in a state in which the detergent is evenly permeated into the laundry, heat and chemical action may directly affect the laundry, thereby improving washing power.

Third, by classifying a case in which the amount of laundry is large and a case in which the amount of laundry is small and differentiating control methods for a washing motor and a pump motor, an optimum washing power may be derived and energy consumption may be optimized.

Advantages and features of the invention and methods to achieve the same are described more fully hereinafter with reference to the accompanying drawings in which embodiments are shown. Rather, these embodiments are provided so that this disclosure is thorough, and will fully convey the scope of the invention to those skilled in the art and this invention is defined by the scope of the claims. Like reference numerals refer to like elements throughout the present specification.

<FIG> is a perspective view illustrating a washing machine according to an embodiment of the present disclosure. <FIG> is a side cross-sectional view illustrating an inside of the washing machine illustrated in <FIG>. <FIG> is a perspective view illustrating a coupling state of a gasket and a distribution pipe illustrated in <FIG>. <FIG> is a rear view of a gasket, illustrating positions of nozzles and a spray form of each nozzle.

Referring to <FIG>, a casing <NUM> forms an exterior of a washing machine, and an inlet <NUM> through which laundry is put is formed on a front surface. The casing <NUM> may include a cabinet <NUM> having an open front surface, a left surface, a right surface, and a rear surface and a front panel <NUM> coupled to the open front surface of the cabinet <NUM> and having the inlet <NUM> formed therein. Bottom and top surfaces of the cabinet <NUM> are open, and a horizontal base <NUM> supporting the washing machine may be coupled to the bottom surface. In addition, the casing <NUM> may further include a top plate <NUM> covering the open upper surface of the cabinet <NUM> and a control panel <NUM> disposed above the front panel <NUM>.

A tub <NUM> containing water may be disposed inside the casing <NUM>. The tub <NUM> has an entrance formed in the front so that laundry may be put therein. The cabinet <NUM> and the tub <NUM> are connected by an annular gasket <NUM>. A door <NUM> for opening and closing the inlet <NUM> may be rotatably coupled to the casing <NUM>.

A heater <NUM> for heating wash water may be provided in the tub <NUM>. The heater <NUM> may be disposed outside the drum <NUM>.

The gasket <NUM> is to prevent water contained in the tub <NUM> from leaking. The gasket <NUM> may extend from an annular front end to an annular rear end of the to form a tubular passage connecting the inlet <NUM> and the inlet of the tub <NUM>. The front end of the gasket <NUM> may be fixed to the front panel <NUM> of the casing <NUM>, and the rear end may be fixed around the entrance of the tub <NUM>.

The gasket <NUM> may be formed of a flexible or elastic material. The gasket <NUM> may be formed of natural rubber or synthetic resin. The gasket <NUM> may be formed of a flexible material such as rubber. The gasket <NUM> may be formed of a material such as ethylene propylene diene monomer (EPDM) or thermo plastic elastomer (TPE). Hereinafter, a portion defining the inside of the tubular shape of the gasket <NUM> is referred to as an inner circumferential portion (or an inner circumferential surface) of the gasket <NUM>, and the opposite portion is referred to as an outer circumferential portion (or an outer surface) of the gasket <NUM>.

A drum <NUM> accommodating laundry may be rotatably provided in the tub <NUM>. A plurality of through-holes <NUM> may be formed in the drum <NUM> so that water in the tub <NUM> may be introduced into the drum <NUM>.

The drum <NUM> is arranged so that the entrance into which the laundry is put is located at the front, and rotates about a substantially horizontal rotation center line C. However, "horizontal" is not a term used in a mathematically strict sense. That is, the rotation center line C inclined at a predetermined angle with respect to the horizontality as in the embodiment may be considered as being substantially horizontal because it is also closer to horizontality rather than verticality. In other words, the rotation center line C may pass through the rear surface of the cabinet <NUM>.

A plurality of lifters <NUM> may be provided on an inner surface of the drum <NUM>. The plurality of lifters <NUM> may be disposed at a predetermined angle with respect to a center of the drum <NUM>. When the drum <NUM> rotates, the laundry is lifted by the lifter <NUM> and then dropped repeatedly.

A driving unit <NUM> for rotating the drum <NUM> may be further provided, and a drive shaft 38a rotated by the driving unit <NUM> may pass through a rear surface of the tub <NUM> and be coupled to the drum <NUM>.

Preferably, the driving unit <NUM> may include a direct-connected washing motor, and the washing motor may include a stator fixed to the rear of the tub <NUM> and a rotor rotated by magnetic force acting between the rotor and the stator. The drive shaft 38a may rotate integrally with the rotor.

The tub <NUM> may be supported by a damper <NUM> installed on the base <NUM>. Vibration of the tub <NUM> induced when the drum <NUM> rotates is attenuated by the damper <NUM>. Although not shown, according to the embodiment, a hanger (e.g., a spring) for suspending the tub <NUM> in the casing <NUM> may be further provided.

The water supply unit may supply water supplied from an external water source such as a faucet to the tub <NUM> or the drum. The water supply unit may include a water supply hose (not shown) for guiding water supplied from an external water source such as a faucet, a water supply pipe <NUM> for guiding the water supplied through the water supply hose to a dispenser <NUM>, and a water supply valve <NUM> intermittently controlling the water supply pipe <NUM>.

The dispenser <NUM> supplies additives such as detergent and fabric softener into the tub <NUM> or the drum <NUM>. In the dispenser <NUM>, additives may be classified and accommodated according to their types. The dispenser <NUM> may include a detergent accommodating portion (not shown) for accommodating the detergent and a softener accommodating portion (not shown) for accommodating the fabric softener.

The water supply pipe <NUM> may include at least one water supply pipe (not shown) for selectively guiding water supplied through the water supply valve <NUM> to each accommodating portion of the dispenser <NUM>.

The gasket <NUM> may include a direct water nozzle <NUM> for spraying water into the drum <NUM>, and a direct water supply pipe <NUM> for guiding the water supplied through the water supply valve <NUM> to the direct water nozzle <NUM>.

Water discharged from the dispenser <NUM> is supplied to the tub <NUM> through a water supply bellows <NUM>. A water supply port (not shown) connected to the water supply bellows <NUM> may be formed on a side surface of the tub <NUM>.

A drain hole for discharging water may be formed in the tub <NUM>, and a drain bellows <NUM> may be connected to the drain hole. A pump <NUM> for pumping water discharged from the tub <NUM> through the drain bellows <NUM> may be provided. A drain valve (not shown) for controlling the drain bellows <NUM> may be further provided.

In the embodiment, the pump <NUM> is a circulation pump for drainage and selectively performs a function of pressure-feed water discharged through the drainage bellows <NUM> to a drain pipe <NUM> and a function of pressure-feed water to a circulation pipe <NUM>. Since a technique of selectively performing circulation and drainage using a single pump is already well known in the washing machine technology field, a detailed description thereof will be omitted.

However, the present disclosure is not limited thereto, and a drain pump for pressure-feeding water to the drain pipe <NUM> and a circulation pump for pressure-feeding water to the circulation pipe <NUM> may be provided separately.

Hereinafter, water pressure-fed by the pump <NUM> and guided along the circulation pipe <NUM> is referred to as circulating water.

The pump <NUM> enables a variable flow rate (or discharge water pressure). A pump motor (not shown) rotating an impeller (not shown) of the pump <NUM> may be a variable speed motor enabling controlling of a rotation speed. The pump motor may be a brushless direct current motor (BLDC), but is not necessarily limited thereto. A driver for controlling a speed of the pump motor may be further provided, and the driver may be an inverter driver. The inverter driver converts AC power into DC power and inputs the DC power to the motor at a target frequency.

A controller (not shown) for controlling the pump motor may be further provided. The controller may include a proportional-integral (PI) controller, a proportional-integral-derivative (PID) controller, and the like. The controller may receive an output value (e.g., output current) of the pump motor as an input, and control an output value of the driver so that a rotation speed of the pump motor follows a preset target rotation speed based thereon. The controller may control not only the rotation speed of the pump motor, but also a rotation direction.

Meanwhile, it should be understood that the controller may control an overall operation of the washing machine as well as the pump motor and each portion mentioned below is controlled by the controller.

Meanwhile, a nozzle <NUM> may be disposed on an inner circumferential surface of the gasket <NUM>. The nozzles <NUM> may be provided in plurality. A plurality of protrusions <NUM> may be formed on an inner circumferential surface of the gasket <NUM>, and nozzles 650a, 650b, 650c, and 650d may be formed on the protrusions <NUM>, respectively.

A distribution pipe <NUM> for guiding the circulating water pressure-fed by the pump <NUM> to the plurality of nozzles <NUM> may be installed in the gasket <NUM>. The distribution pipe <NUM> may have an entrance connected to the circulation pipe <NUM> and may have a plurality of exits for guiding water guided through the entrance to the plurality of nozzles <NUM>.

The plurality of nozzles <NUM> may be classified into upper nozzles 650a and 650c and lower nozzles 650b and 650d according to a height from the gasket <NUM>. In the embodiment, four nozzles 650a, 650b, 650c, and 650d are provided, which may include a first lower nozzle 650b and a second lower nozzle 650d disposed below the gasket <NUM> and a first upper nozzle 650a and a second upper nozzle 650c disposed above the lower 650b and 650d.

A water flow injected through each of the nozzles 650a, 650b, 650c, and 650d reaches a deeper portion of the drum <NUM> as water pressure supplied from the pump <NUM> is higher. That is, by controlling a rotation speed of the pump motor (hereinafter referred to as 'pump rotation speed'), a range of the water flow sprayed from the nozzles 650a, 650b, 650c, and 650d in the drum <NUM> may be controlled.

Referring to <FIG>, when a spray width of a water stream sprayed through the nozzle <NUM> is defined as a spray width angle, a spray width angle β1 of the upper nozzles 650a and 650c may be smaller than a spray width angle β2 of the lower nozzles 650b and 650d.

A difference (β2-β1) between the spray width angle β2 of the lower nozzles 650b and 650d and the spray width angle β1 of the upper nozzles 650a and 650c is approximately <NUM> to <NUM> degrees, and preferably <NUM> degrees. At this time, β1 is approximately <NUM> to <NUM> degrees, preferably <NUM> degrees, and β2 is approximately <NUM> to <NUM> degrees, preferably <NUM> degrees.

Meanwhile, a spray direction of the upper nozzles 650a and 650c may form an upward deviation angle Φ upwardly with respect to a line (R, hereinafter, referred to as a 'nozzle arrangement line') connecting the upper nozzles 650a and 650c and the center O of the gasket 650a. The upward deviation angle Φ may be <NUM> to <NUM> degrees, preferably <NUM> degrees.

Due to various conditions such as the height, position, and spray width angle β1 of the upper nozzles 650a and 650c, in some cases, the spray is not performed with sufficient water pressure through the upper nozzles 650a and 650c, so the sprayed water flow may not be able to go straight to a distance. For this reason, by making a spray direction of the upper nozzles 650a and 650c upward by an upward deviation angle Φ from the nozzle arrangement line R, even when the water pressure of the upper nozzles 650a and 650c is insufficient, the water flow may reach a region that the nozzle arrangement line (R) passes through, and preferably, a shape of the water flow sprayed through the upper nozzles 650a and 650c as shown in <FIG> and a shape of the water flow sprayed through the lower nozzles 650b and 650d may be substantially symmetrical up and down.

Meanwhile, assuming that an angle from the lowest point of the gasket <NUM> to the lower nozzles 650b and 650d is α1, the upper nozzles 650a and 650c are between a highest point H of the gasket <NUM> from a position corresponding to the angle α1 but it may be located above a point corresponding to an angle obtained by dividing <NUM>-α1 into equal parts. That is, in <FIG>, α2 has a larger value than α3. α2-α3 may be <NUM> degrees to <NUM> degrees, preferably <NUM> degrees. In this case, α2 may be <NUM> degrees to <NUM> degrees, preferably <NUM> degrees.

Meanwhile, the lower nozzles 650b and 650d may be positioned at about <NUM>/<NUM> point (<NUM>/<NUM>) of the height H of the gasket <NUM>. In this case, α2 is preferably set in a range in which the upper nozzles 650a and 650c are located higher than <NUM>/<NUM> (<NUM>/<NUM>) of the height of the gasket <NUM>. In this case, α2 may be <NUM> degrees.

In order to evenly spray the circulating water up and down in the drum <NUM>, the upper nozzles 650a and 650c and the lower nozzles 650b and 650d are preferably arranged at equal intervals in the height direction, but in this case, there is a problem in that the water flow sprayed from the upper nozzles 650a and 650c actually reaches a lower region than that geometrically predicted due to deflection of the water flow. Therefore, when considering the deflection of the water flow due to gravity, the upper nozzles 650a and 650c need to be disposed higher than <NUM>/<NUM>.

Meanwhile, when the pump <NUM> is operated and the circulating water is sprayed through the lower nozzles 650b and 650d, a water level in the tub <NUM> preferably does not exceed the <NUM>/<NUM> point.

The method for controlling a washing machine according to the present disclosure may include detecting the amount of laundry put into the drum <NUM>, and a first washing mode and a second washing mode may be selectively performed according to the detected amount of laundry. Here, the first washing mode is performed when the detected amount of laundry is a first laundry amount (e.g., middle amount of cloth), and when the detected amount of laundry is a second laundry amount (e.g., large amount of cloth) that is greater than the first laundry amount, the second washing mode is performed.

Hereinafter, the first washing mode will be described with reference to <FIG> and <FIG>, and the second washing mode will be described with reference to <FIG>.

<FIG> is graphs referenced to describe a control method (the first washing mode) of a washing machine according to an embodiment of the present disclosure, in which (a) is current (W), (b) is electric power, (c) is a rotation speed of the drum, (d) is the amount of supplied water, and (e) represents electrical energy Wh. In particular, the current (a), the electric power (c), and the electrical energy Wh indicate a total amount consumed by the washing motor, the pump motor, and the heater <NUM>.

<FIG> is a table summarizing data referenced to describe a control method (the first washing mode) of a washing machine according to an embodiment of the present disclosure. Hereinafter, a control method of a washing machine according to an embodiment of the present disclosure will be described with reference to <FIG> and <FIG>.

The control method of a washing machine according to an embodiment of the present disclosure may include a washing cycle (S1), a first rinsing cycle (S2), a second rinsing cycle (S3), and a spin-drying cycle (S4).

The first washing cycle (S1) may include washing water supply (S11), heat washing (S12), and post-washing (S13). The washing water supply (S11) is a step of supplying water into the tub <NUM>, in which the water supply valve <NUM> is opened under the control of a controller (not shown). Water is supplied to the dispenser <NUM> through the water supply pipe <NUM>, and the additive (detergent) contained in the dispenser <NUM> is discharged together with the water.

The controller may control various electric devices constituting the washing machine and may include a memory for storing a coded program and a processor for processing data by reading the memory. Hereinafter, it should be understood that 'control' is performed by the controller even if there is no particular mention.

At the time of washing water supply (S11), a first set amount (e.g., <NUM> liters (l)) of water is supplied into the tub <NUM>, and a first drum operation is performed while the water is supplied in this manner. During the first drum operation, rotating the drum <NUM> at a first drum rotation speed (<NUM> rpm in the table of <FIG>) is performed at least once. In addition, operating the pump <NUM> at a first pump rotation speed during the first drum operation may be performed at least once. When a current of <NUM>. 8A is applied to the pump motor, the pump motor may be rotated at a first pump rotation speed. A time required for the washing water supply (S11) may be about <NUM> minutes.

While the drum <NUM> is rotated at the first drum rotation speed, the laundry located at the lowest point in the drum <NUM> may rise to a certain height by the rotation of the drum <NUM> and may be separated from the inner surface of the drum <NUM> to fall. Hereinafter, this type of laundry flow is referred to as a tumbling motion.

The rotation of the drum <NUM> (i.e., rotation at the first drum rotation speed) during the washing water supply (S11) may be repeated a plurality of times. In this case, a ratio (t11 :t12) of the time t11 for which the drum <NUM> is rotated once and the time t12 for which the drum <NUM> is stopped once may be <NUM>:<NUM>. For example, a pattern in which current is applied to the washing motor for <NUM> seconds and then cut off for <NUM> seconds may be repeated.

The rotation of the pump motor may be controlled to be synchronized with the washing motor. That is, the pump motor may be started in response to the starting of the washing motor, and the pump motor may also be stopped in response to the stopping of the washing motor.

Heat washing (S12) may be performed in a state in which the first set amount of water is supplied into the tub <NUM> by the washing water supply (S11). During heat washing (S12), the heater <NUM> is operated, and the second drum operation is performed while the heater <NUM> is operated. In the second drum operation, the drum <NUM> may be rotated at the same speed (a first drum rotation speed) as in the first drum operation.

During heat washing (S12), a ratio (t22/t21 = <NUM>/<NUM>) of one stop time (t22) to one rotation time (t21) of the drum <NUM> is greater than a value (<NUM>/<NUM>) at the time of washing water supply (S11). Since the heater <NUM> consumes a large amount of current during heat washing (S12), an operation rate of the washing motor is lowered (that is, a ratio of the one-time stop time of the washing motor is increased) to suppress consumption of total power.

During heat washing (S12), the start of the pump <NUM> may be controlled to be synchronized with the start of rotation of the drum <NUM>. The one-time operation time of the pump <NUM> may be <NUM> seconds. For example, when the washing motor is started (on), the pump motor may be started (on), it is stopped (off) after being operated for <NUM> seconds, and then when the washing motor is started again, the operation pattern of the pump motor described above may be repeated again.

Meanwhile, during heat washing (S12), the pump <NUM> is operated at a lower speed than during washing supply water (S11). For example, during heat washing (S12), a current of <NUM>. 5A may be applied to the pump <NUM>.

Heat washing (S12) may be carried out for a longer time (about <NUM> minutes) than washing water (S11).

The post-washing (S13) is performed in a state in which the operation of the heater <NUM> is stopped after the heat washing (S12). In the post-washing (S13), a third drum operation in which the drum <NUM> is rotated at the first drum rotation speed (e.g., <NUM> rpm) is performed at least once. Operating the pump <NUM> at the first pump rotation speed is performed at least once during the third drum operation.

In post-washing (S13), a ratio (t32/t31 =<NUM>/<NUM>) of one stop time (t32) to one rotation time (t31) of the drum <NUM> may be smaller than the value (<NUM>/<NUM>) during the heat washing (S12). Since the post-washing (S13) is performed in a state in which the operation of the heater <NUM> is stopped, the operation rate of the washing motor is increased (that is, the ratio of one rotation time of the washing motor is increased) to improve washing power.

A ratio (t41: t42) of a time (t41) for which the pump <NUM> is rotated once (t41) and a time (t42) for which the pump <NUM> is stopped once during the post-washing (S13) may be <NUM>:<NUM>.

A ratio (t32/t31 = <NUM>/<NUM>) of a stop time (t32) to an operation time (t31) of the drum <NUM> in the post-washing (S13) may be smaller than the value (<NUM>/<NUM>) in the heat washing (S12).

The post-washing (S13) may be performed longer (e.g., <NUM> minutes) than the heat washing (S12).

The first rinsing cycle (S2) may include rinsing and spin-drying (S21) and water supply (S22).

The rinsing and spin-drying step (S21) may be a step of spin-drying laundry by rotating the drum <NUM> at a preset spin-drying speed. As the laundry rotates while being adhered to the inner surface of the drum <NUM>, spin-drying is performed.

The pump <NUM> may be operated in an open state of the drain valve. At this time, the pump <NUM> may be operated in the drain mode to discharge wash water through the drain pipe <NUM>. In the rinsing and spin-drying step (S21), the drum <NUM> may be accelerated by stages to reach a spin-drying speed. However, the spin-drying speed may be accelerated at a time without being limited thereto. The spin-drying speed is preferably <NUM> rpm, but is not necessarily limited thereto. The time required for the rinsing and spin-drying (S21) may be approximately <NUM> minutes.

After the rinsing and spin-drying step (S21), the water supply step (S22) may be performed. In the water supply step (S22), water as much as a second set amount (e.g., <NUM> liters (l)) is supplied into the tub <NUM>, and in this process, operating the drum <NUM> at the first drum rotation speed (<FIG>) (<NUM> rpm in the table of <FIG>) may be performed at least once.

A ratio (t51:t52) of a time t51 for which the drum <NUM> is rotated once and a time t52 for which the drum <NUM> is rotated once during water supply (S22) may be <NUM>:<NUM>.

A ratio (t61:t62) of a time t61 for which the pump <NUM> is rotated once and a time t62 for which the pump <NUM> is rotated once during water supply (S22) may be <NUM>:<NUM>. At this time, the pump <NUM> may be operated at the first pump rotation speed.

Water supply (S22) may be carried out for about <NUM> minutes.

The second rinsing cycle (S3) may include rinsing and spin-drying (S31) and water supply (S32). The drum <NUM> and the pump <NUM> are operated in substantially the same manner as the rinsing and spin-drying (S31) and the water supply (S22), respectively, in the rinsing and spin-drying (S31) and the water supply (S32). However, the rinsing and spin-drying (S31) is performed for a shorter time (approximately <NUM> minutes) than the rinsing and spin-drying (S21), and the water supply (S32) may also be performed for a shorter time (approximately <NUM> minutes) than the water supply (S22). In addition, the amount of water supplied at the time of water supply (S32) may be smaller than that of water supply (S22). For example, <NUM> liters (l) may be supplied at the time of water supply (S32).

The spin-drying (S4) may include main spin-drying (S41) and unwinding (S42). The main spin-drying (S41) may be a step of spin-drying laundry by rotating the drum <NUM> at a preset spin-drying speed. As the laundry rotates while being adhered to the inner surface of the drum <NUM>, spin-drying is performed.

The pump <NUM> may be operated in an open state of the drain valve. At this time, the pump <NUM> may be operated in the drain mode to discharge wash water through the drain pipe <NUM>. In the main spin-drying (S41), the drum <NUM> may be accelerated by stages to reach the spin-drying speed. However, the spin-drying speed may be accelerated at a time without being limited thereto. The spin-drying speed is preferably <NUM> rpm, but is not necessarily limited thereto. A time required for the main spin-drying (S41) may be approximately <NUM> minutes.

The cloth unwinding (S42) is to untangle the laundry (cloth) that has been completely spin-dried, and the drum <NUM> may be rotated to induce a tumbling motion. Specifically, the drum <NUM> may be rotated at the first drum rotation speed. In this case, a ratio (t71: t72) of a time t71 for which the drum <NUM> is rotated once and a time t72 for which the drum <NUM> is stopped once may be <NUM>:<NUM>. For example, a pattern in which current is applied to the washing motor for <NUM> seconds and then cut off for <NUM> seconds may be repeated. The cloth unwinding (S42) may be performed for about <NUM> minute.

<FIG> is graphs referenced to describe a control method (a second washing mode) of a washing machine according to an embodiment of the present disclosure, in which (a) is current (W), (b) is electric power, (c) is a rotation speed of the drum, (d) is the amount of supplied water, and (e) represents electrical energy (Wh). In particular, the current (a), the electric power (c), and the electrical energy Wh indicate a total amount consumed by the washing motor, the pump motor, and the heater <NUM>.

<FIG> is a table summarizing data referenced to describe a control method (the second washing mode) of a washing machine according to an embodiment of the present disclosure. Hereinafter, a control method of a washing machine according to another embodiment of the present disclosure will be described with reference to <FIG> and <FIG>.

The method for controlling a washing machine according to another embodiment of the present disclosure may include a washing cycle (S1), a first rinsing cycle (S2), a second rinsing cycle (S3), and a spin-drying cycle (S4).

The first washing cycle (S1) may include washing water supply (S11), heat washing (S12), post-washing (S13), and simple rinsing (S14). The washing water supply (S11) is a step of supplying water into the tub <NUM>, in which the water supply valve <NUM> is opened under the control of a controller (not shown). Water is supplied to the dispenser <NUM> through the water supply pipe <NUM>, and the additive (detergent) contained in the dispenser <NUM> may be discharged together with the water.

At the time of washing water supply (S11), a first set amount (e.g., <NUM> liters (l)) of water is supplied into the tub <NUM>, and a first drum operation is performed while the water is supplied in this manner. During the first drum operation, rotating the drum <NUM> at a first drum rotation speed (<NUM> rpm in the table of <FIG>) is performed at least once. Also, while the first drum operation is performed, operating the pump <NUM> at the first pump rotation speed is performed at least once. When a current of <NUM>. 8A is applied to the pump motor, the pump motor may be rotated at the first pump rotation speed. A time required for the washing water supply (S11) may be approximately <NUM> minutes.

The rotation of the drum <NUM> (i.e., rotation at the first drum rotation speed) during the washing water supply (S11) may be repeated a plurality of times. In this case, a ratio (t11:t12) of the time t11 for which the drum <NUM> is rotated once and the time t12 for which the drum <NUM> is stopped once may be <NUM>:<NUM>. For example, a pattern in which current is applied to the washing motor for <NUM> seconds and then cut off for <NUM> seconds may be repeated.

During heat washing (S12), a ratio (t22/t21 = <NUM>/<NUM>) of one stop time (t22) to one rotation time (t21) of the drum <NUM> may be greater than a value (<NUM>/<NUM>) at the time of washing water supply (S11). Since the heater <NUM> consumes a large amount of current during heat washing (S12), an operation rate of the washing motor is lowered (that is, a ratio of the one-time stop time of the washing motor is increased) to suppress consumption of total power.

Meanwhile, during heat washing (S12), the pump <NUM> may be operated at a lower speed than during washing supply water (S11). For example, during heat washing (S12), a current of <NUM>. 5A may be applied to the pump <NUM>.

Heat washing (S12) may be carried out for longer (about <NUM> minutes) than washing water (S11). In addition, it may be carried out for a longer time (e.g., <NUM> minutes) than the heat washing (S12, see <FIG>. ) in the embodiment described above with reference to <FIG> and <FIG> described above.

In post-washing (S13), a ratio (t32/t31=<NUM>/<NUM>) of one stop time (t32) to one rotation time (t31) of the drum <NUM> may be smaller than the value (<NUM>/<NUM>) during the heat washing (S12). Since the post-washing (S13) is performed in a state in which the operation of the heater <NUM> is stopped, the operation rate of the washing motor is increased (that is, the ratio of one rotation time of the washing motor is increased) to improve washing power.

After the post-washing (S13), simple rinsing (S14) may be performed. Water is fed into the drum <NUM> so that the laundry may be rinsed. The simple rinsing (S14) may be performed for about <NUM> minute.

The first rinsing cycle (S2) may include rinsing and spin-drying (S21), water supply (S22), and rinsing (S23).

After water supply (S22), rinsing (S23) may be performed. Water is fed into the drum <NUM> so that the laundry may be rinsed. The rinsing (S22) may be performed for about <NUM> minute.

A ratio (t71: t72) of a time t71 for which the drum <NUM> is rotated once and a time t72 for which the drum <NUM> is rotated once during rinsing (S23) may be <NUM>:<NUM>.

A ratio (t81:t82) of a time t81 for which the pump <NUM> is rotated once and a time t82 for which the pump <NUM> is rotated once during rinsing (S23) may be <NUM>:<NUM>. At this time, the pump <NUM> may be operated at the first pump rotation speed.

The second rinsing cycle (S3) may include rinsing and spin-drying (S31), water supply (S32), and rinsing (S33). The rinsing and spin-drying (S31), water supply (S32), and rinsing (S33) are performed by the drum <NUM> and the pump <NUM> in substantially the same manner as the aforementioned rinsing and spin-drying (S21), water supply (S22), and rinsing (S23), respectively. However, the rinsing and spin-drying (S31) may be performed for a shorter time (approximately <NUM> minutes) than the rinsing and spin-drying (S21), and the amount of water supplied at the time of water supply (S32) may be smaller than that of the water supply (S22). For example, <NUM> liters (l) may be supplied during the water supply (S32).

The spin-drying process (S4) may include main spin-drying (S41) and cloth unwinding (S42). The main spin-drying (S41) may be a step of spin-drying laundry by rotating the drum <NUM> at a preset spin-drying speed. As the laundry rotates while being adhered to the inner surface of the drum <NUM>, spin-drying is performed.

The pump <NUM> may be operated in a state in which the drain valve is opened. At this time, the pump <NUM> may be operated in the drain mode to discharge the wash water through the drain pipe <NUM>. In the main spin-drying (S41), the drum <NUM> may be accelerated by stages to reach the spin-drying speed. However, the spin-drying speed may be accelerated at a time without being limited thereto. The spin-drying speed is preferably <NUM> rpm, but is not necessarily limited thereto. A time required for the main spin-drying (S41) may be approximately <NUM> minutes.

Claim 1:
A washing machine comprising:
a tub (<NUM>) for storing water;
a drum (<NUM>) rotatably provided in the tub (<NUM>);
a driving unit (<NUM>) rotating the drum (<NUM>);
a water supply unit supplying water supplied from an external water source to the tub (<NUM>);
a pump (<NUM>) having a pump motor and pressure-feeding water discharged from the tub (<NUM>);
a nozzle (<NUM>) spraying the water pressure-fed by the pump into the drum (<NUM>);
a heater (<NUM>) heating the water in the tub (<NUM>); and
a controller controlling the driving unit (<NUM>), the water supply unit, the pump motor, and the heater (<NUM>),
wherein
the controller controls the water supply unit to supply water by a first set amount together with a detergent to the tub (<NUM>), controls the driving unit (<NUM>) to rotate the drum (<NUM>) at a first drum rotation speed while water is being supplied, rotates the pump motor at a first pump rotation speed during the rotation of the drum (<NUM>) at the first drum rotation speed,
operates the heater (<NUM>) in a state in which the first set amount of water is supplied to the tub (<NUM>), controls the driving unit (<NUM>) to rotate the drum (<NUM>) at the second drum rotation speed during the operation of the heater (<NUM>), and operates the pump motor at a second pump rotation speed during the rotation of the drum (<NUM>) at the second drum rotation speed, the second pump rotation speed being lower than the first pump rotation speed,
stops the operation of the heater (<NUM>), controls the driving unit (<NUM>) to rotate the drum (<NUM>) at the third drum rotation speed in a state in which the operation of the heater (<NUM>) is stopped, and rotates the pump motor at the third pump rotation speed during the rotation of the drum (<NUM>) at the third drum rotation speed in a state in which the operation of the heater (<NUM>) is stopped,
wherein a ratio of a stop time (t22) of the drum (<NUM>) to a rotation time (t21) of the drum (<NUM>) when the heater (<NUM>) is operated is greater than a ratio of a stop time of the drum (<NUM>) to a rotation time of the drum (<NUM>) when water is supplied to the tub (<NUM>).