JP2013244384A - Washing machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an energy-saving type washing machine in which clothing having light stain and sweat stain can be washed with fine finish, a washing process can be reduced in time, a water saving effect can be increased, and clothing damage can be reduced with fine finish.SOLUTION: A washing machine has a washing process for washing laundry in a washing tub, a draining process for draining washing water in the washing tub after the washing process, and a rinsing, dewatering and ending process for rinsing and dewatering to finish washing while injecting water after the draining process. The rinsing, dewatering and ending process has a former period dewatering process division, a middle period rinsing and dewatering process division, and a latter period dewatering process division. In the former period dewatering process division, the washing machine dewaters washing water contained in clothing while increasing the number of revolutions of the washing tub in a stepwise fashion. In the middle period rinsing dewatering process division, the washing machine performs shower water injection into the washing tub and performs rinsing and dewatering while rotating at the number of revolutions in the former period dewatering process division. In the latter period dewatering process division, the washing machine stops the shower water injection, further increases the number of revolutions of the washing tub in a stepwise fashion, and continues the dewatering revolutions at the maximum number of increased revolutions to finish this process division.

Description

  The present invention relates to a washing machine that performs centrifugal dewatering while irrigating showers and rinses with water, and relates to a washing machine suitable for washing clothes such as light dirt and sweat dirt.

  A washing machine equipped with this shower water rinsing method is described in, for example, Japanese Patent Application Laid-Open No. 2001-340690 (Patent Document 1).

  The washing machine shown in Patent Document 1 finishes high-speed dehydration of a washing tub after a washing operation, performs rotary shower water injection while rotating the washing tub at a medium speed, and then injects fresh water to rinse.

JP 2001-340690 A

  The shower water dehydration described above is a rinse in which fresh water is poured while the washing tub is rotated at about 150 RPM. Shower water dehydration rinsing requires less rinsing water than reservoir rinsing. Water saving and shortening of the rinsing time can be achieved by performing shower water dehydration rinsing once out of the two rinsing rinses that have been performed so far.

  While this water-saving, power-saving energy saving and shortening of the time required for washing (shortening of time) are proceeding, lightly sweated underwear, light dirt that only passed through the sleeves and clothes with little dirt in the washing machine with a small load Washing is becoming established.

  There already exist washing machines that automatically adjust the amount of washing water and detergent according to the amount of laundry, but in response to washing light and dirt-free clothing (such as sweat stains), water and power saving It is further required to save energy (such as energy saving) and to shorten the time required for washing (short time).

  The present invention addresses the above-described problems and provides a washing machine that can perform washing of light and dirty clothes with little stains with good finish, and that further saves energy and shortens the time required for washing (shorter time). With the goal.

  The present invention relates to a washing process for washing laundry in a washing tub, a draining process for draining the washing water in the washing tub after the washing process, and a rinsing operation by rinsing and dewatering while pouring water after the draining process. The dehydration end process includes the dehydration process section, the middle-stage rinse dehydration process section that follows this first-stage dehydration process section, and the late-stage dehydration process section that follows this medium-term rinse dehydration process section. In the first-stage dehydration step, the washing water contained in the clothes is dehydrated while gradually increasing the number of rotations of the washing tub. In the middle-term rinse dehydration step, the washing tub is rotated while rotating at the number of rotations in the first-stage dehydration step. Water is poured into the shower and rinsed and dehydrated. In the latter-stage dehydration process, the shower water is stopped, and the number of rotations of the washing tub is increased in stages to continue dewatering rotation at the increased maximum rotation speed. Thereby ends the process division from, characterized in that.

  According to the present invention, the washing water is dehydrated while gradually increasing the rotation speed of the washing tub in the first-stage dehydration process section, and the shower is displayed in the washing tub while maintaining the high rotation speed in the first-stage dehydration process section in the middle-term rinsing dehydration process section. Water is poured to rinse and dewater, and in the later stage of dewatering process, shower water is stopped, and the number of rotations of the washing tub is further gradually increased to complete dewatering at the maximum number of rotations. Thereby, the conventional rinsing process can be eliminated, and energy saving and shortening of washing time (shortening time) can be further estimated by saving water by washing laundry such as light dirt and sweat dirt.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a longitudinal sectional view of an entire washing machine according to an embodiment of the present invention. FIG. 1 is an external view of a washing machine main body according to an embodiment of the present invention. The partial expanded sectional view of the shower water injection dehydration according to the embodiment of the present invention is shown. The block diagram of a control means is based on the Example of this invention. It is a figure which concerns on the Example of this invention and compared and showed the process of the washing course. (A) is a driving | operation process of this invention, (b) shows the conventional driving | operation process. It is an operation | movement form figure which concerns on the Example of this invention, and showed the rinse dehydration completion process by time passage (horizontal axis) and the rotation speed (vertical axis) of the washing tub.

  Hereinafter, examples according to embodiments of the present invention will be described with reference to the drawings.

  First, the outline of the washing machine shown in FIG. 1 will be described with reference to FIGS. 1, 2, and 3.

  In the longitudinal sectional view of the washing machine shown in FIG. 1, the outer casing of the washing machine includes an outer frame 1, an outer frame base 2 that supports the outer frame 1 from below, a top cover 3 provided on the outer frame 1, a top The cover 3 has a lid 4 that can be freely opened and closed. The outer tub 5 is anti-vibrated and supported via the anti-vibration springs 21 on the hanging rods 7 suspended from the four corner support portions 8 provided in the upper side of the outer frame 1.

  The washing tub 9 is rotatably placed in the outer tub 5. A DC brushless motor as the washing and dehydrating motor 19 is provided on the bottom side lower surface of the outer tub 5. The washing / dehydrating motor 19 is firmly attached to the outer tub 5 using the flange 20. The rotation main shaft 33 of the washing / dehydrating motor 19 is fixed to the bottom flange 39 of the washing tub 9 and supports the washing tub 9.

  At the center of the rotation main shaft 33, an inner rotation shaft (not shown) for rotating the stirring blade 11 placed in the washing tub 9 so as to be rotatable is provided to the left and right. The washing / dehydrating motor 19 is switched by rotation transmission switching means (not shown). When the rotation transmission switching means is switched, the rotation of the washing and dehydrating motor 19 rotates the stirring blade 11 left and right, and washing is performed.

  When the rotation of the washing and dehydrating motor 19 is transmitted only to the inner rotation shaft, the stirring blade 11 is rotated and the laundry 38 in the washing tub 9 is washed. Further, when the rotation of the washing and dehydrating motor 19 is transmitted to the washing tub 9 by switching the rotation transmission switching means, the washing tub 9 rotates and the laundry 38 is subjected to centrifugal dehydration.

  In the dehydration of the laundry 38, the laundry dewatering motor 19 rotates at high speed, and centrifugal dewatering is performed from the dewatering hole 12 provided in the body of the washing tub 9. Since the washing tub 9 is provided with the balancer 10 at the upper part, the abnormal vibration at the time of imbalance due to the offset of the laundry 38 is alleviated during centrifugal dehydration.

  The control board 27 is provided on the front side of the top cover 3. The power switch 40 is provided on the control board 27. The power switch 40 is turned on, and various input switches provided on the display panel 36 are operated to set the washing conditions.

  The water level sensor 41 is provided on the front side of the top cover 3. The water level sensor 41 communicates with the air chamber 15 of the air trap 14 through the pressure tube 26. The water level of the washing water stored in the outer tub 5 is detected by the water level sensor 41 due to the change in the water pressure, and the water level information is provided to the control board 27 to control the water supply.

  A drain electromagnetic valve 22 as a drain means is provided in a drain passage 23 communicating with a drain port 22 a provided at the bottom of the outer tub 5. Water used for washing and rinsing is drained out of the machine through the drainage channel 23 when the drainage solenoid valve 22 is opened. Next, the dehydration operation in which dehydration is performed is performed with the drain electromagnetic valve 22 open. The control board 27 controls the opening / closing of the drain electromagnetic valve 22, the operation / stop of the washing / dehydrating motor 19, and the speed adjustment.

The water injection case 25 has a water supply electromagnetic valve 6 and a water supply connection port 24. The water supply connection port 24 is connected to a tap water supply faucet 30 via a water supply hose 31, and the tap water supplied from the tap 30 is poured into the washing tub 9 through the water injection case 25 by opening the water supply electromagnetic valve 6. It is.

  The outer tank cover 13 is provided on the upper part of the outer tank 5. Even if the tap water flowing out from the water injection case 25 deviates to the outside of the washing tub 9, it is guided by the outer tub cover 13 and flows out of the machine so as not to wet the floor surface. Is poured into the washing tub 9.

  The detergent tray 16 is provided on the inner peripheral side of the balancer 10 so as to be located directly below the water injection case 25. The outlet of the detergent tray 16 opens toward the water injection case 25. A detergent flow path 17 that communicates with the detergent tray 16 extends downward along the body of the washing tub 9 and has a detergent discharge port 18 that opens to the outside of the bottom of the washing tub 9.

  The detergent is poured into the detergent tray 16 from the water pouring case 25, flows down the detergent flow path 17, accumulates in the outer tub 5 from the detergent outlet 18 located at the lower part of the washing tub 9, and is mixed with the washing water. Dissolve. It is possible to provide a high cleaning effect because it dissolves well and the chemical power of the detergent can be derived effectively.

  A water injection case 25 as a shower water injection means provides a shower-like shower water injection 28 and a detergent injection 29. Since the shower water injection 28 sprinkles water while rotating the washing tub 9 in one direction at a constant speed, it is sprinkled over the entire laundry 38. At the same time, the washing tub 9 is poured from the detergent pouring 29 into the detergent tray 16 every rotation. In addition, a liquid inlet 37 is provided on the front side of the top cover 3 shown in FIG.

  Description will be made with reference to a partially enlarged sectional view (mainly showing the washing tub and the outer tub 5) shown in FIG.

  A softener case 32 is provided in the vicinity of the water injection case 25 at the rear of the top cover 13. The softener charging case 32 includes a softener tank that stores the softener and a supply electromagnetic valve 6 a that controls water for supplying the softener in the softener tank into the washing tub 9. Usually, the supply electromagnetic valve 6a is closed. When the supply electromagnetic valve 6 a is opened at the time of rinsing, water is supplied into the softener case 32 and flows out into the washing tub 9.

  As shown in FIG. 3, when the washing is finished and the state after the drainage-dehydration step (after dehydration), the laundry 38 is uniformly pressed against the inner periphery of the laundry tub 9 by the high-speed rotation of the laundry tub 9. It is in the state. After dehydration is completed, the process proceeds to rinsing for low-speed dewatering while pouring water. In this rinsing, shower water injection 28 from the water injection case 25 is sprayed on the laundry 38 by the control to open the water supply electromagnetic valve 6. At this time, since the washing tub 9 is rotating, the shower water injection 28 is uniformly poured into the laundry 38. At the same time, fresh water is supplied to the softener case 32 by the control of the water supply electromagnetic valve 6a, and the softener mixed with the fresh water is poured into the laundry 38 in the washing tub 9.

  The shower water injection 28 penetrates the inside of the fiber from the surface of the laundry 38 and is centrifugally dehydrated. The detergent contained in the clothes of the laundry 38 is removed from the laundry 38 together with the water to be centrifugally dehydrated. The dewatering after draining, rinsing with water injection and final dehydration following the rinsing will be described in detail later.

  Next, the control circuit of the washing machine will be described with reference to FIG.

  The control circuit is provided in the control board 27 shown in FIG. The control circuit includes a control unit 61 mainly composed of a microcomputer, an input circuit unit 70, and an output drive circuit unit 71. The control unit 61 (control means) includes a CPU 60 (central control unit), a timer 63, a memory 64, an output port 65, and an input port 66. The CPU 60 includes a calculation unit 62a and a control unit 62b. The memory 64 has a RAM 64a and a ROM 64b.

  Connected to the input circuit section 70 are a power switch 40, a water level sensor 41, an IC Hall element 74, a lid opening / closing sensor 75, a fully automatic washing key 76, a manual setting key 77, and a cloth amount sensor 78. Information signals of various switches and sensors are input to the input circuit unit 70, and information is transmitted to the CPU 60 through the input circuit unit 70.

  The output drive circuit unit 71 is connected to a washing / dehydrating motor 19, which is a DC brushless motor, a water supply electromagnetic valve 6, a drainage electromagnetic valve 22, a lid lock solenoid 79, and an end buzzer 80. Various electric devices including the washing and dehydrating motor 19 and the drain electromagnetic valve 22 are operated by the electric power supplied through the output drive circuit unit 71 under the control of the control unit 61 (control means).

  The operation process will be described with reference to FIG. FIG. 5A shows the operation process of this embodiment, and FIG. 5B shows the conventional operation process.

  As shown in FIG. 5 (b), the conventional operation process includes water supply (A), washing (B), drainage (C), dehydration (D), water supply (E), rinse (F), and drainage (G). The final dehydration (H) transitions to the end of the entire washing process.

  On the other hand, as shown in FIG. 5 (a), the operation process of this embodiment is a water supply (a), washing (b), drainage (c), rinsing and dehydration ending process in which dehydration is completed while rinsing and washing is completed. Transition to (d) and finish all the washing steps. It is characterized in that all the washing steps are completed by the rinsing dehydration end step (d) in which dehydration is completed while rinsing.

  The present embodiment omits the conventional water supply (E), rinse (F), drainage (G), and final dehydration (H), and instead of rinsing, the dehydration is completed while rinsing and the washing process is completed. By stepping d), it is possible to perform washing of laundry with little fabric damage and light dirt and little dirt, as well as further rinsing water saving (water saving) and shortening of washing time (shortening of time). Can save power.

  The rinse dehydration end step (d) according to the present embodiment will be described in detail with reference to FIG. The rinsing dehydration end process (d) includes the first-stage dehydration process classification (I), the middle-term rinsing dehydration process classification (II) following this first-period dehydration process classification, and the latter-stage dehydration process classification ( III).

  In the rinsing dehydration end step (d), the total time is about 5 minutes. The operation time of the first-stage dehydration process section (I) is about 0.85 minutes. Mid-term rinse dehydration process category (II) is about 1.5 minutes. Late dehydration process category (III) is about 2.7 minutes.

  When the process proceeds to SR4 after the end of SR3 in the first-stage dehydration process section (I), the number of revolutions of the washing tub 9 is increased to about 350 RPM, and the washing water in the clothes is dehydrated. The rotation speed of the first-stage dehydration process section (I) is SR1, SR2, SR3, and is about 250 RPM at the time, and SR4 of the medium-term rinse dewatering process section (II) is set to 350 RPM. In this way, by dehydrating while increasing the rotational speed of the washing tub 9 stepwise, the washing water contained in the laundry is not rapidly dehydrated when dehydrating, so that the laundry containing the dehydrated detergent is contained. Foaming by the liquid can be suppressed and dehydration can be made smooth.

  The weight of the laundry after washing (b) and draining with drainage (c) contains moisture, so depending on the quality of the clothing (cotton or synthetic fiber), but for cotton clothing 4-5 times the weight of dry clothes before washing. For this reason, in the case of cotton, when the dry clothing weight is 10 kg, the clothing weight after draining is 40 to 50 kg. This is because 30 to 40 L (liters) of moisture is contained in the clothing.

  When the dehydration rotation of the laundry containing a large amount of water is rapidly increased, the dehydrating liquid containing the detergent is rapidly dehydrated, and the balance with the drainage capacity is lost, so that there is a remarkable difference between the outer tub 5 and the washing tub 9. Foaming occurs.

  In addition, there is a problem that the foam filling the space between the washing tub 9 and the outer tub 5 becomes a large resistance to turn the washing tub 9, and the dehydration rotation does not increase and the washing / dehydrating motor 19 generates heat due to an applied load. In order to suppress this foaming, the rotational speed of the first-stage dehydration process section (I) is controlled to prevent the foaming by balancing the drainage and the dewatering by performing the dewatering step by step with the low SR3 rotation shown in FIG. Further, if foaming can be suppressed, the number of stages of rotation increase may be more or less than SR4.

  In the medium-term rinsing dehydration step (II), tap water is poured into the washing tub 9 while rinsing and dewatering while maintaining a high rotational speed (SR4). The high rotational speed (SR4) is not necessarily 350 RPM. The high rotational speed (SR4) includes a range of 250 to 500 RPM. In the medium-term rinsing dehydration step (II), dehydration is performed while maintaining a high rotational speed (SR4) while pouring shower water.

  The reason why the shower water injection is not used together in the first-stage dehydration process section (I) is to suppress the increase in foaming. In SR1-SR3 of the first-stage dehydration process category (I), the dehydration rate of the laundry proceeds to about 40-50%. When water is poured into a place where the dehydration rate is 40 to 50% and the water is dehydrated, the balance of drainage is lost due to the dehydrated dehydrated liquid and the water poured into the shower, and foaming increases between the outer tub 5 and the washing tub 9, As described above, the foam filling the space between the washing tub 9 and the outer tub 5 becomes a great resistance to turn the washing tub 9, and the dehydration rotation does not increase, and the washing / dehydrating motor 19 generates heat and burns due to an applied load. There is a bug to do. For this reason, water injection in the previous dehydration process section (I) was stopped, and water injection was performed in the intermediate rinse dewatering process section (II).

  When the dehydration rotation of SR3 is finished and the process proceeds to the dehydration rotation of SR4, which is the medium-term rinsing dehydration process section (II), the dehydration rate is about 60%. In the medium-term rinsing dehydration process category (II), the dehydration rate is already about 60%, so even if shower water is poured, the injected water is balanced with the drainage capacity and is not drained and foamed. While maintaining the dehydration speed, the dehydration rotation proceeds smoothly and rinsing is performed well.

  In the medium-term rinsing dehydration step (II), the dehydration speed was set to 250 to 500 RPM. The reason for this is that the washing machine has a resonance region where the outer tub 5 swings greatly at a dehydration speed of 180 to 250 RPM, and in this region it is necessary to pass the resonance point quickly. On the other hand, when the dehydration rotation speed exceeds 500 RPM, the water poured into the shower jumps by the washing tub 9 that rotates at high speed. And the floor surface gets wet or the effect of rinsing shower water is reduced by the shower water splashed on the surface of the clothes without passing through the clothes.

  In order to eliminate this resonance region, floor wetting, and decrease in rinsing efficiency, the shower irrigation dehydration operation was carried out while maintaining the dehydration speed of 250 to 500 RPM in the medium-term rinsing dehydration process section (II).

  The shower water injection in the medium-term rinsing and dehydration process section (II) takes 1.5 minutes of water supply (20 L / min). The amount of water injection is 30L. Since 30 L of shower water infiltrate the inside of the fiber from the surface of the clothes for 1.5 minutes and is centrifugally dehydrated, the detergent contained in the clothes is removed, so that rinsing is performed effectively even with one rinse dehydration. .

  In the conventional rinsing, the water supply amount is 75 L, so that the water saving is less than half in the present invention. In addition, although the water supply time for rinsing and rinsing (the amount of water supplied is 75 L) takes 3.75 minutes, in this embodiment, the water supply time is unnecessary, so the time is shortened to 3.75 minutes. Thereby, it is possible to realize time saving, water saving and energy saving.

In the late dehydration process section (III), dehydration is carried out by accelerating the dehydration speed stepwise from 350 RPM to 750 RPM. The maximum number of revolutions can be 1100 RPM exceeding 750 RPM. Since the dehydration speed is accelerated stepwise from 350 RPM to 750 RPM, foaming due to a sudden increase in dehydration is suppressed, and resistance that prevents the washing tub 9 from turning can be kept low. For this reason, the dehydration operation for increasing the dehydration speed smoothly proceeds and the dehydration is performed well. Dehydration in the late dehydration process category (III) exceeds 65% as the dehydration rate.
In the rinsing dehydration end process (d), the first-stage dehydration process section (I), the medium-term rinsing dehydration process section (II), and the latter-stage dehydration process section (III) proceed in succession.

  As described above, the amount of water used for shower water injection in the medium-term rinsing and dehydration step (II) is 30 L because it is 1.5 minutes at 20 L / min. When shower water is poured for 60 seconds continuously, the amount of water injected becomes 20L. When 20 L of water is continuously poured into a shower and centrifugally dehydrated in 60 seconds, the balance with the drainage is lost, resistance to the dehydration rotation becomes impossible, and the dehydration rotation of 350 RPM cannot be maintained, resulting in a decrease in the rotation speed. In order to prevent this, the shower water injection is made intermittent to maintain the balance between shower water injection and drainage so that it does not become the resistance of the washing tub 9, thereby suppressing the decrease in the dewatering rotation speed and the 350 RPM dehydration rotation. Be maintained. Thereby, since stable dehydration rinsing is performed, rinsing efficiency is improved.

  In addition, intermittent shower water injection also saves water by rinsing water. For example, controlling the opening and closing of the water supply electromagnetic valve 6 and intermittent water injection with ON 3 seconds (water injection) and OFF 4 seconds (water injection stop) will be 9.6 times in the case of 60 seconds per 20 L / min. The amount of water to be injected is 6.7 L, and water saving of rinsing water is achieved.

  As described above, the dewatering rotation of the washing tub 9 is increased stepwise in the first-stage dehydration process section (I) and the second-stage dewatering process section (III) of the rinse dehydration end process (d). You may make it raise the spin-drying | dehydration rotation of the washing tub 9 gradually (steplessly). Operation control of the washing and dehydrating motor 19 that increases the dehydrating speed stepwise or gradually (steplessly) is performed by the control means. It is desirable that the operation control be stepped rather than stepless.

  As described above, this embodiment provides a suitable washing machine that improves the water-saving effect while shortening the operation process time for washing clothes such as light dirt and sweat dirt.

  In washing clothes such as light and sweat stains, the amount of detergent used is modest, and there is little stain on the wash water after washing away the stains. For this reason, after draining the washing water, the rinsing dehydration end process (d) having the first-stage dehydration process section (I), the middle-stage dewatering process section (II), and the latter-stage dewatering process section (III) is executed. There are few bruises and the washing finish is improved.

  At the same time, energy saving and shortening of washing time (shorter time) can be further estimated. This washing is also effective for a little washing that is relatively unclean. By providing this washing course (method) in a conventional washing machine, usability of the washing machine is further improved.

5 outer tub 6 water supply electromagnetic valve 9 washing tub 12 dewatering hole 19 washing dewatering motor 22 drainage electromagnetic valve 23 drainage channel 25 water supply case 28 shower water supply 61 control unit (control means)

Claims (3)

A washing tub for washing the stored laundry; an electric motor for rotationally driving the washing tub; a shower irrigating means for injecting water into the washing tub; a draining means for draining water accumulated in the washing tub; the electric motor; In the washing machine provided with a control means for controlling the operation of the water supply means and the drainage means,
The washing machine has a washing process of washing laundry in the washing tub, a draining process of draining the washing water of the washing tub after the washing process, and rinsing and dehydrating while pouring water after the draining process to finish the washing. With a rinsing dehydration end process,
The rinse dehydration end process has a first period dehydration process section, a medium period rinse dehydration process section that follows this first period dehydration process section, and a later stage dehydration process section that follows this medium period rinse dehydration process section,
In the previous dehydration process category, the washing water contained in the clothes is dehydrated while gradually increasing the number of rotations of the washing tub,
In the medium-term rinsing dehydration process, the shower is poured into the washing tub while rotating the washing tub at the number of rotations in the previous dehydration process, and the rinsing dehydration is performed.
In the late dehydration process section, shower water injection is stopped, the number of rotations of the washing tub is further increased stepwise, and the process section is terminated after the dehydration rotation at the increased maximum rotation speed is continued. Machine. A washing tub for washing the stored laundry; an electric motor for rotationally driving the washing tub; a shower irrigating means for injecting water into the washing tub; a draining means for draining water accumulated in the washing tub; the electric motor; In the washing machine provided with a control means for controlling the operation of the water supply means and the drainage means,
The washing machine includes a washing step of washing the laundry in the washing tub, a draining step of draining the washing water in the washing tub after the washing step, and dehydrating while rinsing the laundry after the draining step. Rinsing and dehydration finishing process is completed.
The rinse dehydration end process has a first period dehydration process section, a medium period rinse dehydration process section that follows this first period dehydration process section, and a later stage dehydration process section that follows this medium period rinse dehydration process section,
In the first half of the dehydration process, the washing water contained in the clothing is gradually dehydrated while gradually increasing the number of rotations of the washing tub.
In the medium-term rinsing dehydration process, the shower is poured into the washing tub while rotating the washing tub at a high rotational speed in the first-stage dehydration process,
The washing machine is characterized in that in the latter-stage dewatering process section, shower water injection is stopped, the rotation speed of the washing tub is gradually increased, and the dewatering rotation is continued at the increased maximum rotation speed before the process section is ended. The washing machine according to claim 1 or 2,
The washing machine characterized by intermittently repeating the shower water pouring between 250 RPM and 500 RPM for the rotation speed of the washing tub in the medium-term rinsing dehydration step.