JP2016013361A - Drum-type washing machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a drum-type washing machine which reduces blackening of clothes after washed by suppressing re-attachment of dirt separated from the clothes to the washed clothes.SOLUTION: The drum-type washing machine includes: a dirt concentration detection unit 18 which detects dirt concentration of washing water in a washing tub 2; and a control unit 20. The control unit 20 includes an agitation step of washing clothes by rotationally driving a rotary drum in a washing step, and it also has a blackening suppression course separately from a standard course for performing a standard washing step. In the washing step of the blackening suppression course, a first time washing operation is performed in which a first agitation step is performed in first predetermined time T1 shorter than predetermined agitation step time in the washing step of the standard course and the washing water in the water tub 2 is drained. After that, new washing water is supplied, and additional washing operations are performed a predetermined number of times for performing the agitation step in second agitation step time T2 and draining water, and at the same time, dirt concentration of the washing water in the first agitation step is detected by the dirt concentration detection unit 18, and the number of times of additional washing operations is determined by the detected dirt level and the additional washing operations are performed.

Description

  The present invention relates to a drum type washing machine for washing clothes and the like.

  Conventionally, it has been considered that a drum-type washing machine of this type is provided with a darkening prevention course for improving the cleaning performance and preventing darkening of clothes and the like (for example, see Patent Documents 1 and 2).

  In the conventional drum-type washing machine described in Patent Document 1, when the darkening prevention course is selected, the water level corresponding to the cloth amount detected by the cloth amount detecting means and about twice the standard detergent amount corresponding to the water level. By displaying the amount of detergent, the washing performance is enhanced at a high detergent concentration to prevent darkening of clothing.

  In the conventional drum-type washing machine described in Patent Document 2, when the darkening prevention course is selected, after the amount of cloth is detected, the detergent is added to perform the pre-washing, and then the washing water used for the pre-washing is drained. In this case, the detergent is added again to perform the main washing, thereby improving the cleaning performance and preventing darkening of the clothes.

  In addition, an adsorbent that adsorbs sebum components is provided in the baffle of the rotating drum, and even when the amount of water during washing is small, sebum components washed out from clothing are adsorbed by the adsorbent, and yellowing and It is considered to suppress darkening (see, for example, Patent Document 3).

JP2012-077555 JP 2012-090829 A JP 2011-152247 A

  However, in the conventional configuration, the cleaning power is increased and the amount of water used in the washing process is small, so that the washing water around the laundry clothes also contains dirt including surfactant molecules removed from the clothes. The concentration of the substance increases and the removed dirt adheres again to the clothing during the washing process. In addition, when the amount of washing water is small, dirt substances adhere to the clothes again due to the drainage after the washing process, and in the intermediate dehydration process in which the drum is rotated at high speed, depending on the kind of dirt, it adheres to the clothes surface. The dirty dirt gets into the fiber with the washing water. As a result, dirt remains on the garment even at the end of washing, and repeated washing in such a state causes a problem that the garment becomes dark or yellows over time. In addition, a large amount of detergent is used, and it takes time to rinse. Further, when the adsorbent is used, maintenance such as replacement is necessary, and there is a problem that the usability is poor.

  The present invention solves the above-described conventional problems, and without using a large amount of detergent or using an adsorbent, the reattachment of dirt detached from the clothes is suppressed, and the clothes after washing are washed. An object of the present invention is to provide a drum type washing machine with reduced darkening.

In order to solve the above-described conventional problems, a drum-type washing machine of the present invention includes a housing, a water tank provided in the housing, a rotating drum that is rotatably provided in the water tank and stores clothing. A drive unit that rotationally drives the rotating drum, a water supply unit that supplies washing water into the water tub, a drainage unit that drains the washing water, a water level detection unit that detects a level of the washing water, and the washing A stain concentration detector for detecting the stain concentration of water, and a control unit for controlling a washing process, a rinsing process, a dehydrating process, and the like, and the control unit rotates the rotary drum in the washing process to rotate the clothing. In addition to the standard course for performing the standard washing process, the blackening suppression course is provided separately from the standard course for performing the standard washing process, and in the washing process of the blackening suppression course, the predetermined stirring in the washing process of the standard course The first agitation process is performed in a first agitation process time that is shorter than about a time, and the first washing operation for draining the washing water is performed. Thereafter, new washing water is supplied, and the second agitation process time is An additional washing operation for performing the stirring process and draining is performed a predetermined number of times, and the dirt concentration detection unit detects the dirt concentration of the washing water in the first stirring process, and the additional dirt action is performed based on the detected dirt level. The washing operation is determined and executed.

  As a result, in the first washing operation with the washing water in which a predetermined amount of detergent has been introduced, the first agitation process time is shortened, and the washing water containing a large amount of dirt removed from the clothing is drained once, thereby making the dirt In addition to shortening the time that the clothes are immersed in the wash water, it is possible to surely release the dirt to the new wash water according to the dirt level of the wash water, thereby suppressing the reattachment of the dirt detached from the clothes. Thus, darkening of clothes after washing can be reduced.

  The drum type washing machine of the present invention can reduce the darkness of clothes after washing by suppressing the reattachment of dirt detached from the clothes.

1 is a schematic configuration diagram of a drum-type washing machine according to Embodiment 1 of the present invention. The block circuit diagram of the drum type washing machine in the embodiment of the present invention The time chart which shows the operation | movement of the washing process of the drum type washing machine in embodiment of this invention The figure which shows the repetition frequency of the additional washing operation according to the stain | pollution | contamination level of the washing water of the drum type washing machine in embodiment of this invention

  The first invention includes a housing, a water tank provided in the housing, a rotating drum that is rotatably provided in the water tank, and stores clothes, a drive unit that rotationally drives the rotating drum, A water supply unit for supplying washing water into the aquarium, a drainage unit for draining the washing water, a water level detection unit for detecting the level of the washing water, a stain concentration detection unit for detecting the stain concentration of the washing water, A control unit that controls a washing process, a rinsing process, a dehydration process, and the like, and the control unit includes a stirring process of rotating and driving the rotary drum in the washing process to stir and wash the clothes. A darkening suppression course is provided separately from the standard course for performing the cleansing process. In the washing process of the darkening suppression course, the first stirring process time is shorter than the predetermined stirring process time in the washing process of the standard course. Turbulence A first washing operation for draining the washing water by performing a process is performed, and then additional washing operation is performed for a predetermined number of times by supplying new washing water and performing a stirring process in the second stirring process time to drain the washing water. The stain concentration detector detects the stain concentration of the washing water in the first agitation step, and determines and executes the number of additional washing operations according to the detected stain level. Is.

With this configuration, in the first washing operation with the washing water in which a predetermined amount of detergent is introduced, the first stirring process time is shortened, and the washing water containing a lot of dirt removed from the clothes is drained. In addition to shortening the time that the clothes are immersed in the wash water, it is possible to surely release the dirt to the new wash water according to the dirt level of the wash water, thereby suppressing the reattachment of the dirt detached from the clothes. Thus, darkening of clothes after washing can be reduced.

  According to a second aspect of the invention, in particular, in the first aspect of the invention, the control unit classifies the level of contamination detected by the contamination concentration detection unit, and executes the additional washing operation a predetermined number of times when the contamination level is medium. It is comprised as follows. Thereby, in addition to the effects of the first invention, it is possible to provide a reference for the number of times of performing the additional washing operation, and to reliably release the dirt into the new washing water.

  In a third aspect of the invention, in particular, in the second aspect of the invention, the control unit is configured to perform the additional washing operation more than the predetermined number of times when the degree of dirt detected by the dirt concentration detector is large. It has been done. Thereby, in addition to the effect of 1st invention, discharge | release of the stain | pollution | contamination to a new wash water can be performed effectively.

  In a fourth aspect of the invention, in particular, in the second aspect of the invention, the controller is configured to execute the additional washing operation less than a predetermined number of times when the degree of dirt detected by the dirt concentration detector is small. It is a thing. Thereby, in addition to the effect of 1st invention, reduction of the amount of washing water and shortening of washing time can be aimed at.

  In a fifth aspect of the invention, in particular, in any one of the first to fourth aspects of the invention, the dirt concentration detector is constituted by a turbidity sensor. Thereby, the stain concentration of the washing water can be accurately detected with a simple configuration.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments.

(Embodiment 1)
FIG. 1 is a schematic configuration diagram of a drum-type washing machine according to Embodiment 1 of the present invention. FIG. 2 is a block circuit diagram of the drum type washing machine in the embodiment of the present invention. FIG. 3 is a time chart showing the operation of the washing process of the drum type washing machine in the embodiment of the present invention.

  As shown in FIGS. 1 to 2, a water tank 2 elastically supported by a damper (not shown) or the like is provided in the housing 1. In the water tank 2, a bottomed cylindrical rotary drum 3 for storing laundry such as clothes (hereinafter referred to as clothes) is rotatably provided, and the rotary shaft 3a is provided substantially horizontally and in the front-rear direction.

  A plurality of small holes 5 communicating with the inside of the water tank 2 are provided on the peripheral wall surface of the rotating drum 3. In addition, a plurality of baffles 4 projecting inward toward the rotation center of the rotating drum 3 in the direction of the rotating shaft 3 a are provided on the inner side of the peripheral wall surface of the rotating drum 3. Further, an opening 6 through which clothes are taken in and out is provided on the front side of the rotary drum 3. An openable / closable door 1 a is provided on the front surface of the housing 1. The user can put in and take out clothes from the opening 6 of the rotary drum 3 by opening the door 1a.

  A motor 7 that rotationally drives the rotary drum 3 is attached to the rear surface of the water tank 2 as a drive unit. The motor 7 is composed of a brushless DC motor, and the rotation speed can be freely changed by inverter control.

  Above the water tank 2, a water supply section for supplying washing water into the water tank 2 is provided. The water supply unit includes a water supply pipe 8, a water supply valve 8 a, and a detergent storage unit 9. The water supply valve 8a is provided in the water supply piping 8 connected to the water supply etc. The supplied wash water is supplied into the water tank 2 through the detergent storage 9 provided downstream of the water supply valve 8a. The washing water is stored in the bottom of the water tank 2 and flows into the rotating drum 3 from the small hole 5.

  A water intake 10 a is provided at the lowest part on the rear side of the water tank 2. The intake pipe 10 is connected to the intake port 10a. The other end of the water intake pipe 10 is connected to a filter 11 that captures lint and dust. The tip of the filter 11 branches in two directions, and a drain pipe 12 for draining the washing water in the water tank 2 is connected to one branch. The drain pipe 12 has a drain valve 12a, and the washing water in the water tank 2 is discharged outside the machine through the drain pipe 12 when the drain valve 12a is opened.

  A circulation water channel 14 having a circulation pump 15 is connected to the other branch of the filter 11. The tip of the circulation water channel 14 is a discharge port 13 for discharging the wash water in the water tank 2 taken from the water intake port 10 a into the rotary drum 3 from the opening 6 of the rotary drum 3. It constitutes a circulation path that circulates. That is, the washing water in the water tank 2 is discharged from the discharge port 13 into the rotating drum 3 through the circulating water path 14 by driving the circulation pump 15 provided in the circulation path. It hangs on the clothes and flows down to the bottom of the water tank 2 and circulates.

  An overflow hole 16a is provided in the rear part of the water tank 2, and the overflow water channel 16 communicates the overflow hole 16a and the drain pipe 12. When the water level becomes higher than the overflow hole 16 a, the washing water enters the overflow water channel 16 through the overflow hole 16 a and is discharged outside the machine through the drain pipe 12. The water level detection unit 17 is disposed near the water intake 10 a of the water intake pipe 10 and detects the water level of the washing water supplied into the water tank 2.

  A dirt concentration detection unit 18 is provided in the circulation water channel 14 in front of the circulation pump 15. The dirt concentration detector 18 detects the dirt concentration of the wash water flowing through the circulation channel 14. The dirt concentration detection unit 18 includes a general turbidity sensor (not shown), and has a light emitting element such as an LED and a light receiving element such as a phototransistor facing each other. The light emitted from the light emitting element is received by the light receiving element through the washing water flowing through the circulation path 14, converted into a voltage, and output.

  A control device 19 is provided in the upper part of the front surface in the housing 1. As shown in FIG. 2, the control device 19 includes a control unit 20 configured by a microcomputer, and operates the motor 7, the water supply valve 8 a, the drain valve 12 a, the circulation pump 15, and the like via the power switching unit 21. The washing operation is executed by sequentially controlling a series of steps such as a washing step, a rinsing step, and a dehydrating step. In the washing process, the control unit 20 includes a water supply process, an agitation process for rotating and rotating the rotary drum 3 to agitate and wash the clothes inside, and a draining process. In addition, as a washing course, there is a darkening suppression course for easily darkening clothes apart from a standard course for performing a standard washing process.

  As shown in FIG. 3, the darkening suppression course is a washing process in which a washing operation in which a water supply process, a stirring process, and a drainage process are combined is executed a plurality of times. Specifically, as the first washing operation, the first water supply process is performed, and then the first stirring process is performed at a first stirring process time T1 shorter than a predetermined stirring process time in the washing process of the standard course. Next, a first draining step for draining the washing water is performed. Thereafter, as an additional washing operation, a water supply process of supplying new washing water is performed, and the agitation process is performed at the second agitation process time T2 to perform the drainage process. Then, this additional washing operation is executed a predetermined number of times. That is, the first agitation process is performed in a shorter time than the agitation process of the standard course, the washing water containing a lot of dirt removed from the clothes is drained once, and the time during which the clothes are immersed in the dirty washing water is shortened. Then, the second and subsequent agitation steps are performed with the detergent components remaining after the new water supply, and dirt is released into the new washing water. Thereby, the dirt once detached from the clothes can be prevented from adhering to the clothes again, and the darkening of the clothes after washing can be reduced.

The control unit 20 further includes a washing water stain concentration database, and the first described above.
Based on the output signal from the stain concentration detector 18 that detects the stain of the wash water in the agitation step, it is determined at which stain level the stain concentration of the wash water is, for example, in three stages. And according to this dirt level, the frequency | count of repeating the additional washing operation performed by supplying new washing water mentioned above is determined.

  The input setting unit 22 sets a driving course or the like. The control unit 20 inputs information from the input setting unit 22, displays the information on the display unit 23 based on the information, and notifies the user. The storage unit 24 stores data necessary for control by the control unit 20 including the above-described database.

  The rotational speed detection unit 25 detects the rotational speed of the rotary drum 3. The control unit 20 controls the rotation number of the rotary drum 3 through the power switching unit 21 from the information of the rotation number detection unit 25. The drum type washing machine is supplied with power from the commercial power supply 26 and the power switch 27 is turned on, so that input from the input setting unit 22 becomes possible.

  About the drum type washing machine comprised as mentioned above, the operation | movement and an effect | action are demonstrated below. For example, the washing is performed in the order of a washing step, a rinsing step A, a rinsing step B, and a final dehydration step.

  The user first opens the door 28 provided on the front side of the housing 1 and puts clothes into the rotary drum 3 through the opening 6. Next, when the power switch 27 is turned on, the input setting unit 22 can input a washing course and the like. The washing course can be selected from a plurality of washing courses according to the purpose including the standard course and the darkening suppression course, and is displayed on the display unit 23.

  When the user sets a “darkening suppression course” and operates a start button (not shown) to start operation, a washing process as shown in FIG. 3 is started.

  In the washing step, the control unit 20 detects the amount of clothes first put in the rotary drum 3 by the cloth amount detection unit 29. The amount of clothing can be determined from the torque load applied to the motor 7, the current value of the motor 7, and the like by rotating the rotary drum 3.

  The control unit 20 determines a preset amount of washing water, a detergent amount, and the like according to the amount of clothing detected by the cloth amount detection unit 29, and displays it on the display unit 23 to notify the user. Thereafter, in consideration of the time for the user to add the detergent and softener, after a predetermined time (for example, 1 minute) has elapsed, water supply is started and the first washing operation is executed.

  The water that has passed through the water supply valve 8 a passes through the detergent container 9, and is stored in the water tank 2 as washing water together with the detergent that has been put into the detergent container 9. When the control unit 20 detects that the water level detection unit 17 has supplied water up to a predetermined amount of water level L1, the control unit 20 closes the water supply valve 8a and starts measuring the first stirring process time T1. At this time, the drain valve 12a is closed, and driving of the rotary drum 3 and the circulation pump 15 is stopped.

  When the water supply is completed, the control unit 20 performs a stirring process of rotating the rotating drum 3 to stir the stored clothes. The rotating drum 3 is rotationally driven by the motor 7 so that the tumbling operation can be performed when the clothes are lifted and dropped, for example, 50 r / min. At this time, the motor 7 may be driven so as to rotate the rotating drum 3 alternately forward and backward every predetermined time. For example, the driving is performed as follows: “right rotation 11 seconds → stop 4 seconds → left rotation 11 seconds → stop 4 seconds → right rotation 11 seconds”.

The controller 20 drives the circulation pump 15 together with the motor 7 in the stirring step.
By driving the circulation pump 15, the wash water in the water tank 2 flows into the circulation water channel 14 from the water intake 10 through the filter 11 and is discharged from the discharge port 13 toward the clothing in the rotary drum 3. .

  The dirt concentration detection unit 18 detects the dirt concentration of the washing water before the stirring process is completed. The control unit 20 determines the dirt level of the detected dirt concentration of the washing water based on the database of the dirt concentration of the washing water, supplies the new washing water, agitates again, and performs the number of additional washing operations to drain. To decide. It should be noted that the detection of the dirt concentration is desirably performed immediately before the stirring process is completed as much as possible.

  When measuring that the first stirring process time T1 (for example, 7 minutes) has elapsed, the control unit 20 stops the motor 7 and the circulation pump 15, opens the drain valve 12a, and opens the drain pipe 12 to the inside of the water tank 2. Drain dirty wash water.

  The first stirring process time T1 is set shorter than the predetermined stirring process time in the standard course corresponding to the amount of clothing. In the present embodiment, it is further set to a time that is half or more of the predetermined stirring process time. For example, when the predetermined stirring process time corresponding to the amount of normal clothing is 10 minutes, the first stirring is performed. The process time T1 is not less than 5 minutes and less than 10 minutes, specifically, for example, 7 minutes. As described above, by setting the time shorter than the predetermined stirring process time in the standard course, the contact time between the dirty washing water and the clothes is shortened. In the present embodiment, even if it is shortened, it is set to a time that is half or more of the predetermined stirring process time, so that the removal of dirt by the detergent into which the predetermined amount has been added does not become insufficient.

  The number of repetitions of the additional washing operation performed after the first washing operation is determined by the stain concentration of the washing water detected by the stain concentration detector 18. For example, when the stain level according to the stain concentration of the wash water is divided into three stages, it is determined as the number of repetitions of the additional washing operation corresponding to the stain level of the wash water shown in FIG.

  The predetermined number of times of performing the additional washing operation is, for example, twice based on the dirt level 2 (medium degree of dirt). On the other hand, when the dirt level is 3 (large degree of dirt), the number of repetitions of the additional washing operation performed after the first washing operation is three, which is one more than the predetermined number of times. When the dirt level is 1 (small dirt level), the number of repetitions of the additional washing operation performed after the first washing operation is one less than the predetermined number of times. It should be noted that the number of dirt level categories, the predetermined number of times, and the number of repetitions depending on the degree of dirt are not limited to those described above, but may vary depending on the type of clothing fibers, type of detergent, amount of washing water, temperature, etc. Accordingly, it may be arbitrarily determined.

  As an example of FIG. 4, the case of the dirt level 3 (large dirt degree) will be described with reference to FIG. In the case of the dirt level 3 (large degree of dirt), as shown in FIG. 3, the additional washing operation is repeated three times after the first washing operation. When the first washing operation ends, the control unit 20 performs the second washing operation (additional washing operation first time). In the second washing operation, the control unit 20 opens the water supply valve 8a to perform a water supply process, and stores washing water in the water tank 2 through the detergent storage unit 9. At this time, the drain valve 12a is closed, and driving of the rotary drum 3 and the circulation pump 15 is stopped.

  When the control unit 20 detects that water has been supplied to a predetermined amount of water level L2 set in advance by the water level detection unit 17, the control unit 20 closes the water supply valve 8a and starts measuring the second stirring step time T2. In this water supply process, the detergent is already no longer in the detergent container 9 and only water is supplied, so that the detergent component is only permeated into the clothing, and the detergent concentration in the water tank 2 is reduced.

  When the water supply is completed, the control unit 20 performs a stirring process of rotating the rotating drum 3 to stir the stored clothes. The rotating drum 3 is rotationally driven by the motor 7 so that the tumbling operation can be performed when the clothes are lifted and dropped, for example, 50 r / min. At this time, the motor 7 may be driven so as to rotate the rotating drum 3 alternately forward and backward every predetermined time. For example, the driving is performed as follows: “right rotation 11 seconds → stop 4 seconds → left rotation 11 seconds → stop 4 seconds → right rotation 11 seconds”.

  The controller 20 drives the circulation pump 15 together with the motor 7 in the stirring step. By driving the circulation pump 15, the wash water in the water tank 2 flows into the circulation water channel 14 from the water intake 10 through the filter 11 and is discharged from the discharge port 13 toward the clothing in the rotary drum 3. .

  In this way, the detergent concentration is reduced, but the dirt remaining on the clothing dissolves into the newly supplied wash water along with the detergent components. As a result, the dirt that causes darkening of the clothes is reduced in the time it is in contact with the clothes and is released into the new washing water. Darkening of clothes can be reduced.

  When measuring that the second stirring process time T2 (for example, 5 minutes) has elapsed, the control unit 20 stops the motor 7 and the circulation pump 15, opens the drain valve 12a, and performs the second drain, The washing water in the water tank 2 is drained from 12.

  In this way, the detergent concentration is reduced, but the dirt remaining on the clothing dissolves into the newly supplied wash water along with the detergent components. As a result, the dirt that causes darkening of the clothes is reduced in the time it is in contact with the clothes and is released into the new washing water. Darkening of clothes can be reduced.

When the second washing operation ends, similarly, the third washing operation (additional washing operation second time) is performed as the third stirring step time T3 (for example, 5 minutes), and the fourth washing operation (additional washing operation). The third operation) is sequentially performed as the fourth stirring step time T4 (for example, 5 minutes).
In any additional washing operation, since there is no detergent in the detergent storage unit 9 and only water is supplied, the detergent concentration in the water tank 2 is decreased. However, the dirt released from the garment becomes thinner and thinner, so that the redeposition of the dirt detached from the garment can be effectively suppressed and the darkening of the garment after washing can be reduced.

  When the fourth washing operation is finished, the control unit 20 finishes the washing process.

  Although not shown in the figure, a rinsing step and a final dewatering step are performed following the washing step. When the rinsing process is set twice, the control unit 20 starts the intermediate dehydration of the first rinsing operation as the rinsing process A, rotates the rotating drum 3, and has a predetermined rotational speed through balance control. For example, the rotational speed of the rotary drum 3 is increased to 900 r / min and stopped after a predetermined time. By this intermediate dehydration, the washing water remaining in the clothing at the end of the washing process is discharged outside the machine, and the washing water contained in the clothing is reduced.

  Water supply is performed following the intermediate dehydration. The control unit 20 opens the water supply valve 8a to supply water, and stores washing water in the water tank 2 through the detergent storage unit. When the water level detector 17 detects that water has been supplied to a predetermined water level, the water supply valve 8a is closed.

When the water supply is completed, the control unit 20 performs agitation to rotate the rotating drum 3 and agitate the housed clothes. Similar to the washing step, the rotary drum 3 is driven to rotate by the motor 7 so that the tumbling operation can be performed when the clothes are lifted and dropped, for example, 50 r / min. At this time, the motor 7 may be driven so as to rotate the rotating drum 3 alternately forward and backward every predetermined time. The control unit 20 drives the circulation pump 15 together with the motor 7. By driving the circulation pump 15, the wash water in the water tank 2 flows into the circulation water channel 14 from the water intake 10 through the filter 11 and is discharged from the discharge port 13 toward the clothing in the rotary drum 3. . When a predetermined rinsing time has elapsed, the drain valve 12a is opened to drain the washing water used for rinsing in the water tank 2.

  When the drainage of the rinsing process A is finished, the rinsing process B is performed in the same manner as the rinsing process A.

  Following the two rinse steps, a final dewatering step is performed. In the final dewatering step, the rotating drum 3 is rotated, the rotating speed of the rotating drum 3 is increased to a predetermined rotating speed, for example, 900 r / min through balance control, and stopped after a predetermined time. By this final dehydration step, the washing water remaining in the clothing at the end of the rinsing step is discharged outside the machine, and the washing water contained in the clothing is reduced. When the rotating drum 3 is stopped, a series of washing operations are completed.

  Although not described in detail, in the case of the dirt level 1 (low dirt level), the number of repetitions of the additional washing operation performed after the first washing operation is one time less than the predetermined number of times. It is. As a result, even if the number of repetitions of the washing operation is reduced, it is possible to reduce the darkening of the clothes after washing by suppressing the reattachment of the dirt detached from the clothes because the dirt is originally small. Furthermore, the amount of washing water can be reduced and the washing time can be shortened.

  As described above, in the present embodiment, the rotating drum 3 that is rotatably provided in the water tank 2, the drive unit 7 that rotationally drives the rotating drum 3, and the water supply unit that supplies the washing water to the water tank 2 ( Water supply valve 8 a), drainage part (drainage valve 12 a) for draining the wash water in the water tank 2, water level detection part 17 for detecting the water level of the wash water in the water tank 2, and dirt concentration of the wash water in the water tank 2 And a control unit 20 for controlling each process such as washing, rinsing, and dehydration. When the darkening suppression course is set, the control unit 20 in the standard course The first washing process is performed in the first stirring process time shorter than the stirring process time of the predetermined washing process, and the first washing operation for draining the washing water in the water tank 2 is performed, and then new washing water is supplied. Then, the stirring process is performed in the second stirring process time The additional washing operation of watering is executed a predetermined number of times, and the stain concentration detector 18 detects the stain concentration of the washing water in the first stirring step, and determines the number of additional washing operations based on the detected stain level. Are configured to be executed.

  With this configuration, in the first washing operation with the washing water into which a predetermined amount of detergent has been introduced, the first stirring process time is shortened to once drain the washing water containing a lot of dirt removed from the clothing, It reduces the time that clothes are immersed in dirty washing water, and it can reliably release dirt to new washing water according to the level of dirt in the washing water. It can suppress and reduce the darkening of the clothes after washing.

  In addition, the greater the degree of contamination detected by the soil concentration detection unit 18, the greater the number of additional washing operations for supplying, stirring and draining new washing water, and the smaller the degree of contamination, the greater the number of additional washing operations. As a result, it is possible to reliably release the dirt to the new washing water.

In addition, the timing of the water supply in each process of washing and rinsing, the discharge of the washing water from the discharge port 13 and the rotation of the rotary drum 3 is not particularly limited. For example, the clothes may be agitated by rotating the rotating drum 3 at a low speed at the time of supplying the washing water into the water tank 2. Alternatively, the circulating pump 15 may be driven while supplying water to discharge the washing water to the rotating drum 3. Further, the number of revolutions of the rotating drum 3 is not particularly limited as long as stirring and dehydration are maintained.

  Also, in the washing process, the process of supplying new washing water, stirring, and draining is repeated, so that the amount of detergent contained in the clothes is reduced, and intermediate dehydration may be omitted in the first rinsing process. Good.

  In the present embodiment, the water tank 2 and the rotating drum 3 are arranged horizontally, but may be inclined upward.

  As described above, the drum-type washing machine according to the present invention is useful as a drum-type washing machine because it can suppress redeposition of dirt detached from clothes and reduce darkening of clothes after washing.

DESCRIPTION OF SYMBOLS 1 Case 2 Water tank 3 Rotating drum 7 Motor (drive part)
8 Water supply piping (water supply section)
8a Water supply valve (water supply part)
9 Detergent storage section (water supply section)
12 Drainage pipe (drainage section)
12a Drain valve (drainage part)
17 Water Level Detection Unit 18 Dirt Concentration Detection Unit 20 Control Unit

Claims (5)

A housing, a water tank provided in the housing, a rotary drum rotatably provided in the water tank, housing clothes, a driving unit for rotationally driving the rotary drum, and washing water in the water tank A water supply unit for supplying water, a drainage unit for draining the wash water, a water level detection unit for detecting the level of the wash water, a stain concentration detection unit for detecting the stain concentration of the wash water, a washing step, a rinsing step, A control unit that controls a dehydration process and the like, and the control unit includes a stirring process of rotating and driving the rotary drum in the washing process to stir and wash the clothes and performing a standard washing process A darkening suppression course is provided separately from the course, and in the washing step of the darkening suppression course, the first stirring step is performed with a first stirring step time shorter than a predetermined stirring step time in the washing step of the standard course. The first washing operation for draining the washing water is performed, and then the new washing water is supplied, and the additional washing operation for draining by performing the stirring process in the second stirring process time is performed a predetermined number of times, A drum-type washing machine configured to detect the dirt concentration of the washing water in the first stirring step by the dirt concentration detector, and to determine and execute the number of additional washing operations according to the detected dirt level. . 2. The drum type laundry according to claim 1, wherein the controller is configured to classify a dirt level detected by the dirt density detector and to perform the additional washing operation a predetermined number of times when the dirt level is medium. Machine. 3. The drum type washing machine according to claim 2, wherein the control unit is configured to perform the additional washing operation more than the predetermined number of times when the degree of dirt detected by the dirt density detection unit is large. The drum type washing machine according to claim 2, wherein the control unit is configured to execute the additional washing operation less than the predetermined number of times when the degree of dirt detected by the dirt density detection unit is small. The drum type washing machine according to any one of claims 1 to 4, wherein the dirt concentration detection unit is configured by a turbidity sensor.

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