JP4282461B2 - Drum washing machine - Google Patents

Description

  The present invention relates to a drum type washing machine that accommodates laundry in a drum and performs washing.

  2. Description of the Related Art Conventionally, there is known a drum type washing machine that accommodates laundry in a substantially cylindrical drum that can rotate around a rotation axis extending in a substantially horizontal direction and performs washing. For example, the drum is arranged in an outer tub that can store water during washing, and the drum is rotated by rotating the drum in a state where a certain amount of water is stored in the outer tub. Washing (tapping) can be performed by repeating the operation (tumbling) of lifting up by a baffle provided on the inner surface and allowing it to fall naturally from a certain height toward the water surface.

  When washing with a detergent (general laundry detergent that is not a low-foam detergent) in a drum-type washing machine that performs tapping washing as described above, by rotating the pulsator with water stored in the outer tub Bubbles are more likely to occur than a general washing machine that performs washing (so-called pulsator type washing machine). When foam is abnormally generated in the outer tub, a portion where the foam does not normally enter (for example, in a drum type washing machine having a function of supplying warm air into the outer tub and drying the laundry, There is a risk that bubbles may enter the air passage member for circulating the air in the outer tub and cause failure.

Therefore, a drum-type washing machine that detects the occurrence of bubbles in the outer tub and can remove bubbles or suppress the occurrence of bubbles when bubbles are generated abnormally. Has been proposed (see, for example, Patent Document 1). In the drum-type washing machine disclosed in Patent Document 1, bubbles reach an electrode provided at a predetermined position in the machine (a position where it is desired to detect rising of the bubble), and current flows through the electrode. It is possible to detect that bubbles are abnormally generated in the outer tank.
JP 2003-260290 A

However, the above prior art has a problem in that the cost is increased because an electrode must be provided in the machine in order to detect the occurrence of bubbles in the outer tank.
The present invention has been made under such a background, and an object thereof is to provide a drum type washing machine capable of detecting the generation of bubbles in an outer tub at a low cost.
Another object of the present invention is to detect the occurrence of bubbles in the outer tub at a low cost, and to reduce the generation of bubbles when it is detected that bubbles are abnormally generated in the outer tub. To provide a washing machine.

In order to achieve the above object, an invention according to claim 1 is provided in an outer tub capable of storing water during washing, and disposed in the outer tub, and is set within a predetermined angle range with respect to a horizontal direction during washing. and a drum which is rotated about an axis of rotation, and motor for rotating the drum, a drive current detection hand stage for detecting the driving current of the motor, the water of a constant water level in the outer tub The drum is rotated by rotating the motor at a constant speed, and the laundry in the drum is lifted along with the rotation, and the tumbling that is naturally dropped from a certain height is repeated to repeat the laundry. Based on the fact that a decrease in the driving current of the motor is detected by the driving current detecting means and the driving current detecting means, the bubble detecting means for detecting the generation of bubbles in the outer tub. When a drum-type washing machine, which comprises a.
According to a second aspect of the present invention, water supply is performed to compensate for the water level in the outer tub that is lowered by the water contained in the laundry being absorbed in the drum for a predetermined period after the start of the washing. 2. The apparatus according to claim 1, further comprising a makeup water executing means, wherein the foam detection means detects the generation of the bubbles after the washing and after the water supply is performed by the makeup water execution means. It is a drum type washing machine.
The invention described in claim 3 includes water supply means for supplying water into the outer tub at a fixed timing when the amount of laundry stored in the drum is equal to or less than a predetermined amount. The drum type according to claim 1, wherein the generation of the bubbles is detected based on a driving current before and after water is supplied into the outer tub by the water supply means during the washing. It is a washing machine.

For example, at the time of washing, by the drum in a state of accumulated a certain amount of water into the outer tub is rotated, lifted by baffles laundry in the drum is projected in the drum inner surface, a certain degree of height The so-called scrub washing is achieved by repeating the action (tumbling) of falling naturally from the water toward the water surface. When washing is performed using a detergent (a general laundry detergent that is not a low foam detergent), the water containing the detergent components in the outer tub is agitated when the laundry hits the water surface by tumbling, and foam is generated. .

  When foam is generated in the outer tub during washing, when the laundry naturally falls from a certain height by tumbling, the foam in the outer tub (in the drum) interferes with the laundry. The falling speed of the fabric is reduced, and the impact when the fallen laundry hits the inner surface or the water surface of the drum is alleviated. Therefore, when foam is generated in the outer tub during washing, the amount of load acting on the drum decreases, and the drive current of the motor for driving the drum to rotate decreases.

According to the configuration of the present invention, since the generation of bubbles can be detected based on the decrease in the drive current of the motor for rotating the drum, it is possible to reduce the cost without separately providing components such as electrodes. Generation of bubbles in the outer tub can be detected.
Invention according to claim 4, wherein said drive current detecting means (40,47,50, S8) is intended to the motor (12) detects the steady-state current when rotating at the constant speed as the drive current It is a drum type washing machine (1) according to any one of claims 1 to 3 characterized by things.

During washing, for example, the rotation and stoppage of the motor are repeated intermittently (intermittent operation). In this case, the motor drive current increases immediately after the motor starts rotating from the stopped state, and the drive current becomes steady after a predetermined time.
According to the configuration of the present invention, the steady current when the motor is rotating at a constant speed is detected as the drive current, and the generation of bubbles is detected based on the decrease in the drive current. The generation of bubbles can be detected well based on the current.

According to a fifth aspect of the present invention, the drive current detection means (40, 47, 50, S8) includes an average current during a predetermined period when the motor (12) rotates at the constant speed. Can be detected well as a drive current based on an appropriate drive current .

  In the state where the amount of the laundry accommodated in the drum is small (the state in which the laundry can be appropriately tumbled by the rotation of the drum), the inventor of the present application, when no foam is generated in the outer tub, As the amount of water in the tank increases, the motor drive current increases. On the other hand, if bubbles are generated in the outer tank, the motor drive current does not change much even if the amount of water in the outer tank increases. I found

According to the configuration of the present invention, when the amount of laundry in the drum is small, bubbles are abnormally generated in the outer tub based on the amount of increase in the drive current of the motor before and after supplying water into the outer tub. Since it is possible to detect whether or not there is a bubble, it is possible to more reliably detect the occurrence of a bubble abnormality .

The invention according to claim 6, wherein, when the bubble is detected to be abnormal in the outer tub by the upper Kiawah detecting means (40) (7) in the water has been accumulated in the outer tub Drum-type laundry according to any one of claims 1 to 3 , further comprising drainage control means (40, S11 to S13) for draining a fixed amount and reducing the water stored in the outer tub. Machine (1).

According to this configuration, when bubbles are abnormally generated, a certain amount of water in the outer tub is drained, so that the detergent components contained in the water in the outer tub can be reduced. Generation of bubbles can be satisfactorily suppressed.
The invention of claim 7, wherein, when the bubble is detected to be abnormal in the outer tub by the upper Kiawah detecting means (40) (7) within said rotationally driven by the motor (12) The drum type washing machine (1) according to any one of claims 1 to 3, further comprising drum rotation control means (40, 46) for reducing the rotation speed of the drum (10).

According to this configuration, when the foam is abnormally generated, the rotational speed of the drum is reduced, so that the falling speed of the laundry that naturally falls from a certain height by tumbling is reduced, and the dropped laundry is brought to the water surface. The impact when hitting is reduced. Therefore, since the amount of foam generated when the laundry hits the water surface can be suppressed, the generation of foam in the outer tub can be satisfactorily suppressed.
The invention according to claim 8, wherein, when the bubble is detected to be abnormal in the outer tub by the upper Kiawah detecting means (40) (7) in said motor (12) driving time during the washing The drum-type washing machine (1) according to any one of claims 1 to 3, further comprising a motor drive time shortening means (40, 46, S14) for shortening the speed.

According to this configuration, when bubbles are abnormally generated, the rotation time of the drum is shortened by reducing the driving time of the motor during washing, so the number of times the laundry hits the water surface by tumbling is reduced. To do. Therefore, since the amount of foam generated when the laundry hits the water surface can be suppressed, the generation of foam in the outer tub can be satisfactorily suppressed.
Including intermittent operation executing means (40, 46, S2, S7, S14) for executing intermittent operation for intermittently repeating rotation and stop of the motor (12) during washing, and the motor drive time shortening means (40, 46, S14) may shorten the rotation time of the motor in intermittent operation.

請 Motomeko 9 the described invention, the draining process execution means for executing the draining process for draining all the water has been accumulated on Kigaiso (7) in (40), the upper Kiawah detecting means (40 And a drainage time extending means (40) for extending the time of the drainage process to be executed after that when it is detected that bubbles are abnormally generated in the outer tank. It is a drum type washing machine (1) in any one of 1-3 .

According to this configuration, when bubbles are abnormally generated, the time of the drainage process performed during washing is extended, so that the water and bubbles in the outer tub are discharged better. Therefore, since the amount of foam remaining in the outer tub after the drainage process can be reduced, the generation of foam in the outer tub can be satisfactorily suppressed .

Embodiments of the present invention will be specifically described below with reference to the drawings.
FIG. 1 is a longitudinal sectional view of a drum-type washing machine 1 according to an embodiment of the present invention, and shows a cross-section viewed from the front when cut along a vertical plane along the left-right direction. FIG. 2 is a longitudinal cross-sectional view of the drum type washing machine 1 and shows a cross-section viewed from the right side when cut along a vertical plane along the front-rear direction.

  Referring to FIGS. 1 and 2, the drum type washing machine 1 is partitioned by a casing 2 having an approximately rectangular parallelepiped shape. An opening 4 for taking in and out the laundry that can be opened and closed by the outer lid 2A is formed on the upper surface of the housing 2. Inside the housing 2, an outer tub 7 formed by closing both end faces of a substantially cylindrical peripheral wall 7C with end face walls (the left end face wall 7L and the right end face wall 7R) has its axis line left and right (substantially) (Horizontal). The outer tub 7 is supported by a plurality of dampers 5 at the lower part of the peripheral wall 7C (see FIG. 2).

Inside the outer tub 7, a drum 10 for storing laundry therein is arranged. The drum 10 is formed by closing both end faces of a substantially cylindrical peripheral wall 10C with end face walls (left end face wall 10L and right end face wall 10R), and is arranged so that its axis extends to the left and right (substantially horizontal). Has been.
Rotating shafts 11L and 11R extending along the axis of the drum 10 are attached to the left and right end face walls 10L and 10R of the drum 10, respectively. The rotary shafts 11L and 11R are rotatably attached to the left and right end face walls 7L and 7R of the outer tub 7. A drum driving motor 12 is connected to the left rotating shaft 11L by, for example, a DD (direct drive) system, and the drum 10 connected to the rotating shaft 11L is axially driven by rotating the motor 12. It is designed to rotate around at the same rotational speed. On the inner surface of the peripheral wall 10C of the drum 10, three baffles 10B for lifting the laundry in the drum 10 when the drum 10 rotates are spaced apart from each other at equal intervals in the circumferential direction (every 120 °). It protrudes so as to extend in the left-right direction.

  An opening 22 for taking in and out the laundry is formed in a part of the peripheral wall 10C of the drum 10. An opening 23 is formed in the peripheral wall 7 </ b> C of the outer tub 7 at a position facing the opening 4 of the housing 2. The opening 22 of the drum 10 can be opened and closed by a drum lid 25 that can rotate outward, and the opening 23 of the outer tub 7 can be opened and closed by an inner lid 26 that can rotate outward. It has become. By opening all of the outer lid 2A, the inner lid 26, and the drum lid 25, the laundry can be taken in and out of the drum 10 through the openings 4, 22, and 23.

  A water supply port 2B is formed at the rear of the upper surface of the housing 2 (see FIG. 2), and tap water (hereinafter simply referred to as “water”) from the outside water supply facility (such as a water tap) through the water supply port 2B. ")") Can be introduced. A water supply valve (not shown) is connected to the water supply port 2B, and water is introduced into the machine through the water supply port 2B by opening the water supply valve. The water introduced into the machine from the water supply port 2 </ b> B is supplied into the outer tub 7 from the rear end portion of the peripheral wall 7 </ b> C of the outer tub 7 through the water supply pipe 17.

  A drain port 19 is formed at the lower right side of the peripheral wall 7 </ b> C of the outer tub 7. By supplying water with the drain valve 18 connected to the drain port 19 closed, water can be stored in the outer tub 7. A large number of water passage holes (not shown) are formed in the peripheral wall 10C of the drum 10, and the water supplied into the outer tub 7 flows into the drum 10 through the water passage holes. It has become. The water stored in the outer tub 7 is discharged out of the machine through the drain port 19 and the drain hose 20 by opening the drain valve 18.

  When washing is performed in a normal operation course in the drum type washing machine 1, the washing process, the rinsing process, and the dehydrating process are executed in this order. In the washing process and the rinsing process, the drum 10 is rotated while water is stored in the outer tub 7 up to a certain water level, and the laundry in the drum 10 is lifted by the baffle 10B along with the rotation. The action (tumbling) of falling naturally from the top is repeated. By repeating the tumbling, the laundry is struck against the water surface of the water stored in the outer tub 7, and so-called tapping is achieved.

At the time of dehydration, the drum 10 is rotated at a high speed (for example, 300 to 1000 rpm), so that water contained in the laundry in the drum 10 is squeezed out by centrifugal force. Then, the water squeezed out from the laundry is scattered to the outer tub 7 side through the water passage hole of the drum 10 and is discharged from the drain port 19.
The drum type washing machine 1 also has a function of drying the dehydrated laundry, and a drying unit 3 for the drying function is attached to the right end surface wall 7R of the outer tub 7 from the outside (see FIG. 1). The drying unit 3 warms the air in the outer tub 7 sucked through an air passage member (not shown) communicating with the inside of the outer tub 7 by the two drying heaters 34, and then the right end wall of the outer tub 7. It is led into the outer tub 7 from the blower port 31 formed at the center of 7R toward the left.

At the time of drying, by rotating the drum 10 while sending warm air from the drying unit 3 into the outer tub 7, the operation of lifting the laundry in the drum 10 by the baffle 10B and dropping it naturally from a certain height is repeated. It is. Thereby, the laundry in the drum 10 can be uniformly exposed to warm air, and the laundry can be dried well.
FIG. 3 is a block diagram showing an electrical configuration of the drum type washing machine 1.

  The operation of the drum type washing machine 1 is controlled by a control unit 40 including a microcomputer. The control unit 40 includes a CPU 41, a RAM 42, a ROM 43, an A / D converter 44, and the like. In addition, the control unit 40 functionally includes a water level measurement unit 45, a rotation speed control unit 46, a current measurement unit 47, and the like by the microcomputer executing program processing.

  For example, an operation display panel 6 provided on the upper surface of the housing 2 is attached to the control unit 40 so that input / output is possible. The user can perform various settings (such as setting the water level stored in the outer tub 7 during washing) by operating the operation display panel 6, and a signal based on the operation of the operation display panel 6 is input to the control unit 40. It has come to be. Further, the control unit 40 can display the operation status and setting contents of the drum type washing machine 1 on the operation display panel 6 by outputting a signal to the operation display panel 6.

  The control unit 40 is connected to the water supply valve 13 and the drain valve 18 described above via a valve driving unit 48. In addition, a signal from the water level sensor S <b> 1 for detecting the water level stored in the outer tub 7 is input to the control unit 40. The control unit 40 measures the water level in the outer tub 7 based on the signal from the water level sensor S1 by the water level measuring unit 45, and opens and closes the water supply valve 13 or the drain valve 18 to thereby change the water in the outer tub 7. The desired water level can be obtained.

In addition, the motor 12 described above is connected to the control unit 40 via an inverter control unit 49. The rotation speed control unit 46 of the control unit 40 can inverter-control the rotation speed of the motor 12 via the inverter control unit 49.
A current detection circuit 50 is connected to a middle portion of the wiring connecting the inverter control unit 49 and the motor 12. The current detection circuit 50 is for detecting the drive current of the motor 12 flowing from the inverter control unit 49 to the motor 12. When a signal representing the drive current of the motor 12 detected by the current detection circuit 50 is input to the control unit 40, the current measurement unit 47 of the control unit 40 measures the drive current of the motor 12 based on the input signal. Will be.

  FIG. 4 is a diagram illustrating a change in the drive current of the motor 12 when washing is performed without using a detergent. FIG. 5 is a diagram showing a change in driving current of the motor 12 when washing is performed using a detergent (a general laundry detergent that is not a low foam detergent). 4 and 5 respectively show that 3 kg of laundry is stored in the drum 10 and water is stored in the outer tub 7 up to a certain water level, and the motor 12 is rotated forward at 45 rpm for 10 seconds (in FIG. 2). (Clockwise rotation), the motor 12 is stopped for 3 seconds, then the motor 12 is reversed at 45 rpm for 10 seconds (counterclockwise in FIG. 2), and the motor 12 is stopped again for 3 seconds (intermittent) The change of the drive current of the motor 12 when the operation is repeated is shown.

As shown in FIGS. 4 and 5, immediately after the motor 12 starts rotating from the stopped state, the drive current of the motor 12 increases to 4 A or more, and a predetermined time (for example, about 3 seconds) elapses from the start of rotation. At that time, the driving current of the motor 12 becomes steady at about 2A.
When washing is performed without using a detergent as shown in FIG. 4, that is, when no bubbles are generated in the outer tub 7, the driving current of the motor 12 in a steady state is obtained even when intermittent operation is repeated a plurality of times. The (steady current) is about 2A and is almost constant. On the other hand, when washing is performed using a detergent as shown in FIG. 5, that is, when bubbles are generated in the outer tub 7, the steady current of the motor 12 gradually decreases as the intermittent operation is repeated a plurality of times. To do.

  When washing is performed using a detergent as shown in FIG. 5, water containing the detergent component in the outer tub 7 is stirred when the laundry hits the water surface by tumbling, and bubbles are generated in the outer tub 7. When bubbles are generated in the outer tub 7 during washing, the bubbles in the outer tub 7 (in the drum 10) interfere with the laundry when the laundry naturally falls from a certain height by tumbling. As a result, the falling speed of the laundry is reduced, and the impact when the dropped laundry hits the inner surface or the water surface of the drum 10 is alleviated. Therefore, when foam is generated in the outer tub 7 during washing, the amount of load acting on the drum 10 decreases, and the drive current of the motor 12 for driving the drum 10 to rotate decreases.

  In this embodiment, when the motor 12 is rotating at a constant speed (for example, 45 rpm) during washing (for example, during the washing process), when the drive current of the motor 12 is decreased by a predetermined rate or more, that is, the motor 12 is rotated. When the drive current reduction amount D with respect to the steady current (about 2 A) of the motor 12 at the initial stage of a predetermined sequence to be controlled (for example, a second sequence to be described later) is a predetermined ratio (for example, 50% (about 1 A)) or more. In addition, it is detected that bubbles are abnormally generated in the outer tub 7 (in the drum 10), and processing (bubble suppression processing) for suppressing the generation of bubbles in the outer tub 7 is executed. Yes.

As described above, according to the configuration in which the steady current when the motor 12 is rotating at the constant speed is detected as the drive current, and the occurrence of the bubble abnormality is detected based on the decrease in the drive current, It is possible to satisfactorily detect the occurrence of bubble abnormality based on a more appropriate driving current.
However, the present invention is not limited to the above configuration, and an average current during a certain period when the motor 12 is rotating at the constant speed (for example, a period from when the driving current of the motor 12 is in a steady state to when it is stopped). (About 7 seconds from when the motor 12 starts to rotate until about 3 seconds elapses until the motor 12 starts rotating and about 10 seconds elapses until the motor 12 stops) Even if it is configured to detect the occurrence of bubble abnormality based on the decrease in the drive current, the average occurrence of bubbles is detected well based on the appropriate drive current. can do.

FIG. 6 is a flowchart showing a flow of control by the control unit 40 during the washing process. In FIG. 6, a driving course in which the washing process is executed for 12 minutes will be described as an example.
With reference to FIG. 6, when the washing process is started, the control unit 40 first opens the water supply valve 13 and supplies water into the outer tub 7 to the water level set by the operation of the operation display panel 6. After (step S1), rotation control of the motor 12 in the first sequence is started (step S2). In the first sequence, the motor 12 is normally rotated at 45 rpm for 2 seconds, the motor 12 is stopped for 3 seconds, the motor 12 is then reversed at 45 rpm for 2 seconds, and the motor 12 is stopped again for 3 seconds. Such intermittent operation is repeated. Thereby, the laundry in the drum 10 is moved by the baffle 10B at the bottom of the drum 10, and the water stored in the outer tub 7 (in the drum 10) is well absorbed by the laundry.

  When 1 minute has elapsed since the start of the first sequence (YES in step S3), the control unit 40 has the water level of the water stored in the outer tub 7 lowered based on the input signal from the water level sensor S1. It is determined whether or not (step S4). When the water level in the outer tub 7 is lowered (YES in step S4), the control unit 40 supplies water to the set water level by opening the water supply valve 13 for a certain time (makeup water; step S5). ). On the other hand, when the water level in the outer tub 7 is not lowered (NO in step S4), the makeup water is not performed.

If the replenishment water has been finished (step S5) or when it has been determined that the water level in the outer tub 7 has not decreased (NO in step S4), 6 minutes have not passed since the start of the washing process (step S6). In step S3), the control unit 40 continues the first sequence while determining again whether one minute has elapsed since that time (step S3).
In this way, it is determined whether or not the water level in the outer tub 7 is lowered a total of 6 times, and when the water level is lowered, makeup water is supplied so that 6 minutes from the start of the washing process. (YES in step S6), the control unit 40 ends the first sequence and starts the second sequence (step S7). In the second sequence, the motor 12 is normally rotated at 45 rpm for 10 seconds, the motor 12 is stopped for 3 seconds, and then the motor 12 is reversed at 45 rpm for 10 seconds, and then the motor 12 is stopped again for 3 seconds. Such intermittent operation is repeated.

  After starting the second sequence, the control unit 40 measures the steady current (drive current) of the motor 12 during the first motor rotation based on the input signal from the current detection circuit 50 (step S8), and the measured drive Current data is stored in the RAM 42. Thereafter, the control unit 40 continues the current of the motor 12 when the motor 12 rotates (forward or reverse) at 45 rpm until 12 minutes have elapsed from the start of the washing process (until YES in step S16). (Drive current) is compared with the drive current of the motor 12 at the time of the first motor rotation stored in the RAM 42 to determine whether the drive current of the motor 12 is reduced by 50% or more (step S9). ), The second sequence is continued. If 12 minutes have passed without the drive current of the motor 12 decreasing by 50% or more (YES in step S16), the control unit 40 ends the washing process at that time.

  On the other hand, when the drive current of the motor 12 has decreased by 50% or more by 12 minutes after the start of the washing process (YES in step S9), the control unit 40 has abnormally generated bubbles in the outer tub 7. The bubble suppression process is executed. That is, the control unit 40 stops driving the motor 12 and stops the rotation of the drum 10 (step S10), and then opens the drain valve 18 (step S11) and is stored in the outer tub 7. Reduce water. When the control unit 40 detects that the water level in the outer tub 7 has decreased to a predetermined water level based on the input signal from the water level sensor S1 (YES in step S12), it closes the drain valve 18 (step S13). ), The first sequence similar to the control content in step S2 is started (step S14).

Thereafter, the control unit 40 continues the first sequence until 12 minutes have elapsed from the start of the washing process, and ends the washing process when 12 minutes have elapsed from the start of the washing process (YES in step S15).
In this embodiment, since the generation of bubbles can be detected based on the decrease in the drive current of the motor 12 for driving the drum 10 to rotate, it is possible to reduce the cost without separately providing parts such as electrodes. Generation of bubbles in the tank 7 can be detected.

In particular, since the occurrence of bubble abnormality is detected based on the reduction amount D of the drive current when the motor 12 is rotating at a constant speed (for example, 45 rpm), the motor 12 is controlled according to the load amount acting on the drum 10. Even when the drive current changes, it is possible to satisfactorily detect the occurrence of bubble abnormality based on the decrease D of the drive current with respect to the drive current of the motor 12 according to the load amount.
As in the above embodiment, the second sequence is performed when the laundry in the drum 10 is sufficiently absorbed to supply water and the drop in the water level in the outer tub 7 is reduced (or the drop in water level is eliminated). The driving current of the motor 12 due to the change in the amount of water in the outer tub 7 and the fact that water is not sufficiently absorbed by the laundry. It is possible to prevent variation from occurring. Therefore, it is possible to better detect the occurrence of bubbles.

  However, as in the above embodiment, when the reduction amount D of the drive current when the motor 12 is rotating at a constant speed (for example, 45 rpm) is greater than or equal to a predetermined ratio (for example, 50%), the outer tub 7 For example, the amount of decrease D in the drive current when the motor 12 is rotating at the constant speed is not less than a predetermined value (for example, 1A). In some cases, it may be configured to detect that bubbles are abnormally generated in the outer tub 7.

  In addition, the present invention is not limited to the configuration in which the occurrence of bubble abnormality is detected based on the reduction amount D of the drive current when the motor 12 is rotating at a constant speed (for example, 45 rpm). A configuration may be adopted in which it is detected that bubbles are abnormally generated in the outer tub 7 based on the fact that the drive current when rotating at a predetermined value (for example, 1 A) or less has been reduced.

In this embodiment, when it is further detected that bubbles are abnormally generated in the outer tub 7 (YES in step S9), the drain valve 18 is opened and a certain amount of water in the outer tub 7 is drained. Therefore (steps S11 to S13), the detergent component contained in the water in the outer tub 7 can be reduced, and the generation of bubbles in the outer tub 7 can be satisfactorily suppressed.
In this embodiment, when it is detected that bubbles are abnormally generated in the outer tub 7 (YES in step S9), the rotation control of the motor 12 by the control unit 40 is changed from the second sequence to the first sequence. Switching is made (step S14). In the second sequence, the rotation time of the motor 12 in the intermittent operation is 10 seconds, whereas in the first sequence, the rotation time of the motor 12 in the intermittent operation is 2 seconds. Therefore, when bubbles occur abnormally, the rotation time (driving time) of the motor 12 during washing is shortened and the rotation time of the drum 10 is shortened, so the number of times the laundry hits the water surface by tumbling. Decrease. Therefore, since the amount of foam generated when the laundry hits the water surface can be suppressed, the generation of foam in the outer tub 7 can be satisfactorily suppressed.

  However, as in the above-described embodiment, when it is detected that bubbles are abnormally generated in the outer tub 7, the configuration is not limited to shortening the rotation time of the motor 12, but for example, the motor 12 in intermittent operation Even if the configuration is such that the stop time is extended, the amount of foam that disappears during the stop time of the motor 12 (during the stop time of the drum 10) increases, so that the generation of bubbles in the outer tub 7 is well suppressed. it can.

  In addition, when it is detected that bubbles are abnormally generated in the outer tub 7, the rotational speed of the motor 12 (the rotational speed of the drum 10) at least during forward rotation and reverse rotation is reduced. However, tumbling reduces the falling speed of the laundry that falls naturally from a certain height, and the impact when the falling laundry hits the water surface is alleviated, so the foam generated when the laundry hits the water surface is reduced. The amount can be suppressed, and the generation of bubbles in the outer tub 7 can be satisfactorily suppressed.

  In this embodiment, when the washing process is completed, the drain valve 18 is opened to drain all the water in the outer tub 7, and then the water is again supplied into the outer tub 7 and the rinsing process is performed. It has come to be. Accordingly, when it is detected that bubbles are abnormally generated in the outer tub 7 during the washing process, the water in the outer tub 7 and Since the bubbles are discharged more favorably and the amount of bubbles remaining in the outer tub 7 after the drainage process can be reduced, the generation of bubbles in the outer tub 7 can be satisfactorily suppressed.

In addition, when it is detected that bubbles are abnormally generated in the outer tub 7 during the washing process, even if it is configured to increase the number of executions of the rinsing process (add and execute the rinsing process), Since the detergent component contained in the laundry can be diluted more favorably, the generation of bubbles in the outer tub 7 can be satisfactorily suppressed.
In the above embodiment, the drive current of the motor 12 is measured after starting the second sequence in step S7 of FIG. 6 (step S8), and the occurrence of a bubble abnormality is generated based on the reduction amount D of the drive current of the motor 12 at that time. However, the present invention is not limited to this configuration (or in addition to such a configuration), and when the amount of laundry in the drum 10 is small, for example, it is sufficient for laundry. After the water is absorbed into the outer tank 7, the driving current of the motor 12 is measured. Thereafter, the water is supplied into the outer tub 7, the water level in the outer tub 7 is raised, and the driving current of the motor 12 is measured again. A configuration may be adopted in which the occurrence of bubble abnormality is detected when the increase amount of the drive current is a predetermined value (for example, 0.3 A) or less.

  In this case, whether or not the amount of the laundry in the drum 10 is small can be determined based on the number of makeup water until the water level in the outer tub 7 is not lowered. For example, when the water level in the outer tub 7 is not lowered before the replenishing water is performed the maximum number of times (for example, 6 times), it is determined that the amount of laundry in the drum 10 is small, and the sixth water level Immediately before the detection of the decrease, the motor 12 is rotationally controlled in the second sequence, and the drive current of the motor 12 at that time is measured. When 6 minutes have passed since the start of the washing process, the water supply valve 13 is opened, a fixed amount (for example, about 1 liter) of water is supplied into the outer tub 7, and the drive current of the motor 12 whose rotation is controlled in the second sequence Is measured again. When the increase amount of the driving current of the motor 12 measured in this way is a predetermined value (for example, 0.3 A) or less, it is detected that bubbles are abnormally generated in the outer tub 7, and bubble suppression is performed. Processing is executed.

  In the case where the amount of the laundry stored in the drum 10 is small (the state in which the laundry can be appropriately tumbled by the rotation of the drum 10), the inventor of the present application has no foam in the outer tub 7. As the amount of water in the outer tub 7 increases, the drive current of the motor 12 increases. On the other hand, when bubbles are abnormally generated in the outer tub 7, the motor 12 I discovered that the drive current does not change much. Therefore, when the amount of laundry in the drum 10 is small, bubbles are abnormally generated in the outer tub 7 based on the amount of increase in the drive current of the motor 12 before and after supplying water into the outer tub 7 as described above. By adopting a configuration that detects whether or not the bubble is detected, it is possible to more reliably detect the occurrence of the bubble abnormality.

The present invention is not limited to the contents of the above embodiments, and various modifications can be made within the scope of the claims.
For example, the drive current of the motor 12 is not limited to a configuration that detects that bubbles are abnormally generated in the outer tub 7 based on a decrease in a predetermined amount or more or a decrease in a predetermined value or less. The configuration may be such that the generation amount of bubbles can be detected according to the drive current value of the motor 12 or the decrease amount of the drive current.

The drum 10 is not limited to a configuration in which the axis extends in the left-right direction, and may be configured to extend in the front-rear direction, for example. In this case, the axis of the drum is not limited to a configuration extending substantially in the horizontal direction, and may be inclined within a predetermined angle range (for example, up to about 30 °) with respect to the horizontal direction.
The present invention is not limited to a so-called top open type drum-type washing machine in which laundry is put in and out of the drum 10 through an opening 22 formed in a part of the peripheral wall 10C of the drum 10. The present invention can also be applied to a drum type washing machine of a type in which laundry is taken in and out of the drum through an opening formed in the end face wall.

It is the longitudinal cross-sectional view of the drum type washing machine which concerns on one Embodiment of this invention, Comprising: The figure which looked at the cross section when cut | disconnected by the vertical surface along the left-right direction is shown from the front. It is the longitudinal cross-sectional view of a drum-type washing machine, Comprising: The figure which looked at the cross section when cut | disconnected by the vertical surface along the front-back direction is shown from the right side. It is a block diagram which shows the electric constitution of this drum type washing machine. It is a figure which shows the change of the drive current of the motor at the time of washing without using a detergent. It is a figure which shows the change of the drive current of a motor at the time of washing using detergent (general laundry detergent which is not a low foaming detergent). It is a flowchart which shows the flow of control by the control part in the washing process.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Drum type washing machine 7 Outer tub 10 Drum 11L, 11R Rotating shaft 12 Motor 40 Control part 46 Rotational speed control part 47 Current measurement part 50 Current detection circuit

Claims (9)

An outer tub that can store water during washing;
A drum disposed in the outer tub and rotated around a rotation axis set within a predetermined angle range with respect to the horizontal direction during washing;
A motor for rotationally driving the drum;
Drive current detection means for detecting the drive current of the motor;
The water is stored in a constant water level in the outer tub and the drum is rotated by rotating the motor at a constant speed, and the laundry in the drum is lifted along with the rotation and is naturally dropped from a certain height. A washing control means for repeatedly washing the laundry by tumbling;
Based on the detection of a decrease in the drive current of the motor by the drive current detection means during the washing, a foam detection means for detecting the generation of bubbles in the outer tub,
A drum-type washing machine comprising:   A replenishment water execution means for supplying water in order to compensate for the water level in the outer tub that is lowered by absorbing water by the laundry contained in the drum for a predetermined period after the start of the washing;
  The drum type washing machine according to claim 1, wherein the foam detection means detects the generation of the foam during the washing and after water supply is performed by the makeup water execution means.   Water supply means for supplying water into the outer tub at a certain timing when the laundry stored in the drum is below a predetermined amount;
  The foam detection means detects the generation of the foam based on a driving current before and after water is supplied into the outer tub by the water supply means during the washing. The drum-type washing machine according to 1. It said drive current detecting means, a drum type washing machine according to any of claims 1-3, characterized in that in order to detect the steady-state current of the motor as the drive current. It said drive current detecting means, a drum type washing machine according to any of claims 1-3, characterized in that in order to detect the average current over a period of time of the motor as the drive current. When the bubble to the outer tank by the upper Kiawah detecting means is detected to be abnormal, it is accumulated in the outer tub in the drained water being accumulated in the outer tub by a predetermined amount The drum type washing machine according to any one of claims 1 to 3, further comprising drainage control means for reducing the amount of water. When it is detected that the foam to the outer tank is abnormally generated by the upper Kiawah detecting means, and characterized in that it comprises a drum rotation control means for reducing the rotational speed of the drum which is rotated by the motor The drum type washing machine according to any one of claims 1 to 3 . When it is detected that the foam to the outer tank is abnormally generated by the upper Kiawah detection means, according to claim characterized in that it comprises a motor driving time shortening means for shortening the driving time of the above SL motor 1 The drum type washing machine according to any one of 3 above. And draining process execution means for executing the draining process for draining all the water has been accumulated on Symbol outer tub,
When the bubble to the outer tank by the upper Kiawah detecting means is detected to be abnormal, claims, characterized in that it comprises a drainage time extension means for extending the time of the drainage process which is executed thereafter Item 4. The drum type washing machine according to any one of Items 1 to 3 .

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