EP2118354B1

EP2118354B1 - Laundry machine for washing functional clothes or delicate clothes and controlling method of the same

Info

Publication number: EP2118354B1
Application number: EP08704954.0A
Authority: EP
Inventors: Soo Young Oh; Myong Hun Im; Jae Won Chang; Kyung Chul Woo; Kyeong Hwan Kim
Original assignee: LG Electronics Inc
Current assignee: LG Electronics Inc
Priority date: 2007-01-26
Filing date: 2008-01-25
Publication date: 2020-10-14
Anticipated expiration: 2028-01-25
Also published as: EP2118354A4; WO2008091124A2; WO2008091124A3; EP2118354A2

Description

Technical Field

The present invention relates to a washing machine having a steam supply unit. More specifically, the present invention relates to a washing course with steam.
In general, in the washing machines, there are pulsator type washing machines and drum type washing machines, and drying and washing machines which not only wash, but also dry laundry.

Background Art

In related art of washing machines, there are washing machines each having a steam supply unit which enhances a washing effect significantly and improves energy efficiency by performing washing with steam supplied from the steam supply unit.
FIG. 1 illustrates a drum type washing machine as an example of the related art washing machine.
Referring to FIG. 1, the washing machine is provided with a body 110, a tub 120, a drum 130, and a steam supply unit.
The body 110 forms an exterior of the drum type washing machine, and the tub 120 is suspended in the body 110.
The drum 130 is rotatably mounted in the tub 120, with an opening positioned to face a laundry opening 111 in the body 110.
Mounted to the laundry opening 111 of the body 110, there is a door for opening/ closing the laundry opening 111, and the laundry opening 111 has a rim 150 on an inside circumference for sealing between the door 140 and the laundry opening 111.
The drum 130 has a plurality of pass through holes in a circumferential surface for introduction of washing water and steam into the drum 130.
The steam supply unit is provided to supply a predetermined amount of steam to the drum 130.
The steam supply unit vaporizes water with heat to provide steam to the drum 130.
The steam supply unit is provided with a heat generating unit 210 for vaporizing water with heat, and a steam supply tube 220 which is a flow passage for introducing the steam from the heat generating unit 210 to the drum.
The steam supply unit is also provided with a spray nozzle 230 for spraying the steam through the steam supply tube 220 into the drum 130.
The spray nozzle 230 has a shape of a nozzle for smooth spray of the steam, and an end directed to an inside of the drum 130 for spray of the steam.
Though the spray nozzle in the above is directed to the inside of the drum directly, the spray nozzle can be mounted to be directed to an inside of the tub. The steam sprayed into the tub can be introduced into the drum through the pass through holes in the drum.
A related art normal washing course of the washing machine having the steam supply unit thus is provided with a washing step, a rinsing step, and a spinning step. As each of the steps are progressed, progressing of the step and a progressed or remained time period are displayed.
FIG. 2 illustrates a graph showing time versus a temperature in the drum (or the tub) in a washing step or a rinsing step of the related art normal washing course.
Referring to FIG. 2, in the related art normal washing course with steam, the washing step has a drum temperature set to approx. 40°C and a washing time period set to approx. 40 minutes. In the washing step, the drum rotates in a regular direction and a reverse direction alternately, with a on-time period and a off-time period set to 18 seconds and 6 seconds respectively at a ratio, which is a service ratio, of 3:1 as shown in FIG. 3.
The rinsing step is performed for three times for fixed time periods respectively, using cold water at a final rinsing. The spinning is performed at 800rpm of the drum rotation.
In this instance, in order to bring a temperature of the drum to a temperature (hereafter called as a washing temperature) set for the washing step, the steam is sprayed into the drum, or, if necessary, hot water is circulated with a circulating pump (not shown in FIG. 1) from the tub to the drum. In order to check whether the washing temperature is reached or not, a temperature of the drum or the tub is sensed with a temperature sensor.
By using steam rather than by using hot water only, water and energy is saved, and a washing performance is enhanced.
EP 1657 342 A1 discloses a method of controlling a washing machine. The washing machine includes a tub to contain laundry and a duct, having an outlet, through which air is circulated and dried before flowing back into the tub through the outlet during a drying cycle. The method has a wash cycle that includes the steps of heating water to generate steam and spraying the steam into the duct so that it flows into the tub through the outlet.

Disclosure of invention

Technical Problem

Recently, as living standards improve, there has been much necessity for washing functional clothes, such as sports wears. Most of such a functional clothes are expensive because the functional clothes uses special cloth, for an example, having a waterproof function in which rain water can not infiltrate from an outside into an inside of the clothes, and a water repelling function in which sweat is repelled from the inside to the outside of the clothes.
However, because the conventional washing course is set to be suitable for general clothes, it is not suitable for washing the functional clothes. If the functional clothes is washed with the convetional washing course, the cloth is liable to be damaged to loss the function, or shrink, to spoil the expensive functional clothes. Due to the washing time period, the washing temperature, the service ratio of the motor, the on-time period and the off-time period of the motor, the number of times of rinsing, a rotation speed of the drum in the spin-drying step, and so on, the cloth of the functional clothes is liable to be shrinked or damaged to lose the function.
Due to those, it is the present situation in which the consumers leave washing of the functional clothes in hands of laundry shop. However, since there are many occasions in which the functional clothes, such as the sports wears, are put on two, or three times weekly, it is inconvenient to leave washing of the functional clothes in hands of laundry shop in view of time or cumbersome.
Moreover, washing clothes of delicate cloth, such as pure cotton, or linen, with the related art washing course causes damage to the clothes. Particularly, underwear of the pure cotton, or thin summer clothes of the linen are susceptible to be damaged due, not. only to the delicacy of the cloth, but also to the thinness and tenderness of the cloth.
In the meantime, through satisfactory in view of damage prevention of the cloth, a related art wool washing course is not adequate in view of washing effect compared to a general washing course.
Particularly, if the washing effect of the underwear is not adequate, the underwear is not good in view of hygiene. Moreover, the recent thin expensive underwear of delicate cloth, such as pure cotton, is tender in most cases. Therefore, though a washing course having an adequate washing effect and causes no damage problem has been in needs, there has been no such a washing course.
The present invention is for a new washing course which is suitable for washing functional clothes, such as sportswear, or delicate clothes of delicate cloth, such as pure cotton, or linen.

Technical Solution

A controlling method of a washing machine according to the present invention includes a step of receiving a selection of a functional clothes course or a delicate clothes course, a washing step for washing laundry with steam, having a washing temperature set substantially to 27 ∼ 33°C, a rinsing step for rinsing the laundry, and a spin-drying
step for spin-drying the laundry, whereby the rinsing step includes two times of rinsing, and whereby each of said two times of rinsing is performed for a preset time period by using hot water at the first time of rinsing and cold water at the second time of rinsing.
According to the invention, the washing temperature is set to 27 ∼ 33°C, preferably 30°C.
Underwear has a large chance of secretions, including protein, from human body sticking thereto. In the cases, a washing effect of the underwear is poor if high temperatured water is used in the washing.
The control unit controls supplying of hot water and steam with checking a temperature of the drum sensed by a temperature sensor until the washing temperature is reached. For reaching the washing temperature, the drum may be rotated, and the hot water may be circulated from the tub with a circulating pump.
A case in which the washing temperature is reached by using steam and hot water is much more effective in view of time and energy than a case in which the washing temperature is reached by using the hot water only. It is more effective if the drum is rotated and the circulating pump is used.
Moreover, since the steam reaches to every corner of the laundry in the drum, the steam is effective for the washing effect.
In a case the functional clothes is washed, it is preferable that the drum is rotated in regular/reverse directions alternately with a motor service ratio of 1:2 in the washing step. In this instance, preferably, a motor on-time period is 11 ∼ 15 seconds. Or, the motor service ratio can be 13 seconds: 24 seconds.
In a case the delicate clothes is washed, it is preferable that the drum is rotated in regular/reverse directions alternately with a motor service ratio of 1:5 in the washing step. In this instance, preferably, a motor on-time period is 4 ∼ 6 seconds. Or, the motor service ratio can be 4.5 seconds: 19 seconds.
A washing time period in the washing step may be set to 21 ∼ 27 minutes, preferably 24 minutes.
The method for controlling a washing machine may further include a step for supplying detergent. The detergent supply step may be at an initial stage of a course.
The detergent supplied in the detergent supply step may be neutral detergent or alkali detergent. The alkali detergent can prevent the cloth form suffering from damage further. Preferably, the neutral detergent is used for functional clothes, such as sports wear, and the alkali detergent is used for delicate clothes, such as underwear.
The detergent box in the washing machine may have a partition for holding the alkali detergent and a partition for holding other kind of detergent. In this instance, the water flowing from the water supply valve to the detergent box is introduced to the alkali detergent partition and therefrom to the tub together with the alkali detergent. Or if the neutral detergent is used, the water is supplied to the neutral detergent partition, to supply the neutral detergent to the tub.
At the time of detergent supply, the control unit may give a message to the user to determine existence of the alkali detergent or the neutral detergent in the detergent box. For an example, a message may be displayed on an LCD screen requesting to check existence of the alkali detergent or the neutral detergent in the detergent box. If the user checks the detergent box, and takes a required action, the control unit may start water supply to supply the washing water together with the detergent. In this instance, the user's action may be an opening/closing of the detergent box (the washing machine may be provided with a sensor that can sense opening/closing of the detergent box), or user's pressing of a button, for an example, a start bottom.
Or, the step for receiving the neutral detergent or alkali detergent may be a step for introducing the detergent to the washing machine by the user. For this, the control unit may stand by for a preset time period while issuing a preset warning sound and displaying a preset warning message, and the user may supply the neutral or alkali detergent to the washing machine during the standby.
Preferably, the rinsing step includes two times of rinsing. The related art rinsing step has three times of rinsing or more.
The spin-drying step has a drum rotation speed of 360 ∼ 440 rpm, preferably, 400 rpm.
In washing delicate clothes of pure cotton or linen or functional clothes, such as sports wear, it is important to provide a good washing effect while preventing the cloth suffering from damage. The method for controlling a washing machine of the present invention can meet such requirements.
In the meantime, the washing machine of the present invention has the above decribed method.
In detail, the washing machine according the present invention includes a steam supply unit for supplying steam to a drum, and a controller to control the steam supply unit to perform by using the steam a washing step having a washing temperature set to 27 ∼ 33°C.
The controller controls the water supply valve to supply hot water to the tub, controls the steam generating unit to supply the steam, and checks a temperature with a temperature sensor provided for sensing a temperature in the drum to meet the washing temperature.
In order to control the washing machine by the control method according to the invention, the controller has a functional clothes course, or delicate clothes course as washing courses set according to control methods. The courses may be programmed at the controller.
A course selector may be provided to an input unit for enabling the user to select the course, the input unit enabling the user to select the washing course, and to input orders, such as starting of operation of the course.

Advantageous Effects

The present invention has following advantageous effects.
The present invention can provide a good washing effect while giving no damage to delicate clothes of delicate cloth, such as pure cotton or linen, or functional clothes such as sports clothes.
The present invention can provide significantly good washing effect while showing almost no difference in view of cloth damage compared to the conventional wool washing course.

Brief Description of the Drawings

The accompanying drawings, which are included to provide further understanding of the disclosure and are incorporated in and constitute a part of this application, illustrate embodiments of the disclosure and together with the description serve to explain the principle of the disclosure.
In the drawings:

FIG. 1 illustrates a related art washing machine;
FIG. 2 illustrates a related art 40°C normal course;
FIG. 3 illustrates a service ratio of a motor in a washing step of a related art 40°C normal course;
FIGS. 4 and 5 illustrate controlling methods in accordance with a first preferred embodiment of the present invention, respectively;
FIG. 6 illustrates a service ratio of a motor in a washing step of the embodiment in FIGS. 4 and 5;
FIG. 7 illustrates a controlling method in accordance with a second preferred embodiment of the present invention;
FIG. 8 illustrates a service ratio of a motor in a washing step of the embodiment in FIG. 7;
FIG. 9 illustrates a graph showing test results of washing effects for different courses; and
FIG. 10 illustrates a graph showing test results of shrinkages of cloth for different courses.

Mode for the Invention

Reference will now be made in detail to the specific embodiments of the present invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts.
Referring to FIG. 4, once a functional clothes course is selected (S10), a series of steps set suitable for the course is performed, including a washing step S20, a rinsing step S30, a spinning step S40.
FIG. 5 illustrates time versus temperature in the washing step and the rinsing step.
Referring to FIG. 5, the washing step S20 is performed at a washing temperature of 30 C, a washing time period of 24 minutes, and a service ratio of 13 seconds:24 seconds, and so on.
In order to perform the washing at the washing temperature, the control unit puts the steam supply unit into operation, to supply the steam to the drum. In this instance, in the washing step, how water is used, and the circulating pump is operated to circulate the washing water to the tub.
The control unit supplies the hot water, circulates the washing water to the tub with the circulating pump, supplies the steam, and checks a temperature with a temperature sensor which can sense a temperature of the drum. If the control unit determines that the sensed temperature is 30°C, which is a set washing temperature, the control unit stops steam supply and keeps performing the washing step S20.
In the washing step S20, preferably, neutral detergent is used. The detergent box already has the detergent filled by the user, and the control unit controls to open the water supply valve such that the washing water is supplied to the tub together with the detergent as the washing water passes through the detergent box.
In the washing step S20, the drum rotates in regular/reverse directions alternately, with a service ratio of the motor set to 13 seconds:24 seconds. That is, power applying steps are repeated, in which the power is applied to the motor to rotate the motor in a regular direction for 13 seconds, to turn off the power for 24 seconds, and to rotate the motor in a reverse direction for 13 seconds. The drum may be controlled to rotate only in one direction. FIG. 6 illustrates a power wave form for above motor service ratio.
The washing step S20 is performed for a washing time period set to 24 minutes. Once the washing course is finished, the rinsing step is performed.
In the rinsing step S30, two times of rinsing is performed. Each time of the rinsing is performed for a preset time period, by using hot water at the first rinsing, and cold water at the second rinsing.
After the rinsing step S30, the spin-drying step is performed.
In the spin-drying step S40, a rotation speed of the drum is set to 400rpm. In order to prevent the functional clothes suffering from damage, it is preferable that the spinning of the drum is performed at a comparatively low speed.
Because the washing conditions set in the washing step is milder than the washing conditions in the related art washing course, only two times of rinsing is performed in the rinsing step, and spinning is set to be performed at a lower rotation speed of the drum, damage to the functional clothes can be prevented.
In the meantime, a delicate clothes course will be described with reference to FIG. 7. As shown, once the user selects the delicate clothes course (S110), a series of steps set suitable for the course is performed, including a washing step S120, a rinsing step S130, a spinning step S140. Time versus washing temperature in the washing step and the rinsing step are similar to FIG. 5.
The washing step S 120 is performed at a washing temperature of 30°C, a washing time period of 24 minutes, and a motor service ratio of 13 seconds:24 seconds, and so on.
In order to perform the washing at the washing temperature, the control unit puts the steam supply unit into operation, to supply the steam to the drum. In this instance, in the washing step, how water is used, and the circulating pump is operated to circulate the washing water to the tub.
The control unit supplies the hot water, circulates the washing water to the tub with the circulating pump, supplies the steam, and checks a temperature with a temperature sensor which can sense a temperature of the drum. If the control unit determines that the sensed temperature is 30°C, which is a set washing temperature, the control unit stops steam supply and keeps performing the washing step.
In the washing step S120, preferably, alkali detergent is used. The detergent box already has the detergent filled by the user, and the control unit controls to open the water supply valve to supply the washing water to the tub together with the detergent as the washing water passes through the detergent box. In this instance, the control unit may display a guide message on an LCD screen to verify presence of the alkali detergent in the detergent box.
In the washing step S120, the drum rotates in regular/reverse directions alternately, with a service ratio of the motor set to 4.5 seconds:19 seconds. That is, power applying steps are repeated, in which the power is applied to the motor to rotate the motor in a regular direction for 3 seconds, to turn off the power for 19 seconds, and, then, to rotate the motor in a reverse direction for 3 seconds. The drum may be controlled to rotate only in one direction. FIG. 6 illustrates a power wave form for above motor service ratio.
The washing step S120 is performed for a washing time period set to 24 minutes. Once the washing course is finished, the rinsing step is performed.
In the rinsing step S130, two times of rinsing is performed. Each time of the rinsing is performed for a preset time period, by using hot water at the first rinsing, and cold water at the second rinsing.
After the rinsing step S130, the spin-drying step is performed.
In the spin-drying step S140, a rotation speed of the drum is set to 400rpm. In order to prevent the delicate clothes suffering from damage, it is preferable that the spinning of the drum is performed at a comparatively low speed.
Because the washing conditions set in the washing step S120 is milder than the washing conditions in the related art washing course, only two times of rinsing is performed in the rinsing step S130, and spinning is set to be performed at a lower rotation speed of the drum, damage to the delicate clothes can be prevented.
FIGS. 9 and 10 illustrate graphs showing test results on washing effects and degrees of clothes damages in a related art general washing course (so called 40°C normal course) and a course for washing wool (so called wool course) and washing courses of the control methods of the foregoing embodiments, respectively.
Referring to FIG. 9, the washing course of the present invention has washing effects almost similar to the related art general washing course, and better than the related art wool course, significantly.
FIG. 10 illustrates a graph showing test results of shrinkages of delicate cloth for different courses. As shown, the 40°C normal course shows more than 5% of shrinkage of cloth, which is a degree unable to wear the clothes again, and the wool course shows shrinkage in a range of 3.24% which is acceptable, whereas the delicate clothes course or the functional clothes course shows shrinkage in a range of middle of 3% which is acceptable similar to the wool course.
In conclusion, the functional clothes course or the delicate clothes course minimizes damage to the cloth while having a washing effect in a range of the related art 40°C normal course.
In the meantime, since the washing machine in accordance with a preferred embodiment of the present invention has an exterior which is not different from the washing machine in FIG. 1 significantly, the present invention has been described focused on different points.
The washing machine in accordance with a preferred embodiment of the present invention has a control unit having a program for performing the foregoing control method.
An input unit, for allowing a user to select a washing course and to start operation of the course, is provided with a selecting unit for enabling selection to perform washing by the control method. That is, a selecting unit is provided to the input unit for enabling to select the functional clothes course, or the delicate clothes course.
According to this, if the user puts the laundry in the drum, selects a course through the input unit, and applies an operation start order, the control unit performs washing according to the foregoing control method.

Industrial Applicability

The present invention relates to a washing machine having a steam supply unit. More specifically, the present invention relates to a washing course with steam. The present invention can provide a washing effect the same as the related art washing course while giving no damage to delicate clothes of delicate cloth, such as pure cotton or linen, or functional clothes such as sports clothes.

Claims

A method for controlling a washing machine comprising:
a step of receiving a selection of a functional clothes course or a delicate clothes course;

a washing step for washing laundry with steam, having a washing temperature set substantially to 27°C - 33°C,

a rinsing step for rinsing the laundry; and

a spinning step for spinning the laundry,
characterized in that the rinsing step includes two times of rinsing, whereby each of said two times of rinsing is performed for a preset time period by using hot water at the first time of rinsing

and cold water at the second time of rinsing.
The method as claimed in claim 1, wherein in the washing step, a time ratio between a motor-on time and a motor-off time is 1 : 2, substantially.
The method as claimed in claim 2, wherein the time ratio includes a motor turn on time period of 11 ∼ 15 seconds, substantially.
The method as claimed in claim 1, wherein in the washing step, a time ratio between a motor-on and a motor-off time is 13 seconds : 24 seconds, substantially.
The method as claimed in claim 1, wherein in the washing step, a time ratio between a motor-on and a motor-off time is 1 : 5, substantially.
The method as claimed in claim 5, wherein the time ratio includes a motor on-time period of 11 ∼ 15 seconds, substantially.
The method as claimed in claim 1, wherein in the washing step, a time ratio between a motor-on and a motor-off time is 4.5 seconds : 19 seconds, substantially.
The method as claimed in one of claims 1 to 7, wherein the washing step has a washing time period set to 21 ∼ 27 minutes.
The method as claimed in one of claims 1 to 7, wherein the spinning step has a drum rotation speed of 360 ∼ 440 rpm, substantially.
The method as claimed in one of claims 1 to 7, wherein the washing step includes a step of supplying alkali detergent.
The method as claimed in one of claims 1 to 7, further comprising a step for displaying a guide message to guide a user to check existence of alkali detergent in a detergent box, before the washing step.