JPH11244570A - Washing machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To shorten washing time by performing first spin drying first rinse and second spin drying after washing revolving a wash and spin drying basket with maximum first number of revolutions in the first spin drying and revolving the wash and spin drying basket with the second number of revolutions which is more than the first number of revolutions. SOLUTION: When washing is fed in a wash and spin drying basket 4 and a start switch provided on an operation part 20 is operated, wash time, rinse time and spin drying time which are suitable for the quantity of the laundry and cloth quality of the laundry are determined and washing is carried out. At this time, the wash and spin drying basket is revolved and driven by a motor 7 at the time of spin, low speed revolution is divided into two stages of the numbers of revolutions x1, x2 for spin drying of one time and each stage is performed for each time t1, t2. Next, high speed revolution is controlled to be performed with the number of high speed revolutions x3 for time t3. By performing low speed revolution at first at the time of spin drying, the generation of bubble is suppressed. Subsequently, required spin drying can be contrived for short time by performing high speed revolution in a state that detergent is hardly left.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a washing machine in which washing, rinsing, and dewatering are performed in the same washing and dewatering tub, and more particularly to a method for controlling a washing machine during dehydration.

[0002]

2. Description of the Related Art In a conventional washing machine in which washing, rinsing and dewatering are performed in the same washing and dewatering tub, a washing and dewatering tub that rotates by a detergent remaining on the laundry during dehydration after washing and a water tub that covers the outer periphery thereof are provided. Generates bubbles in the gaps. When the generated amount of the foam is larger than the amount of the foam discharged from the drain port to the outside of the water tub, the space is filled with the foam, and a so-called foam constraint that is a resistance to the rotation of the washing and dewatering tub has occurred. . Foam restraint occurs when the rotation speed is higher than the rotation speed of the washing and dewatering tub suitable for the amount of remaining detergent, and when foam restraint occurs, the rotation speed of the washing and dewatering tub does not increase to a desired value, thereby reducing the dewatering effect. In order to reduce this, means for avoiding bubble restraint are disclosed in JP-A-5-7689 and JP-A-5-49782.

In Japanese Unexamined Patent Publication No. Hei 5-7689, foam restraint is detected by an increase in the number of revolutions per unit time of a motor for rotating a washing and dewatering tub, and the dewatering process is stopped to remove foam and residual water from the water tub. After discharging to the outside, the dehydration step is performed again. Also, in Japanese Patent Application Laid-Open No. 5-49782,
A method in which foam restraint is detected by detecting whether or not the number of rotations of a motor has reached a predetermined number of rotations within a predetermined time, the dehydration step is stopped, bubbles and residual water are discharged out of the water tank, and then the rinsing step and the dehydration step are performed again. It is.

[0004]

However, according to the above-mentioned method, when bubbles are generated at the beginning of the dehydration step,
Since the rotation speed of the motor is low, the rotation speed increases while having resistance due to the bubble restraint, so that the bubble restraint cannot be detected until a certain rotation speed is reached, or the bubble restraint cannot be detected until a predetermined time has elapsed. Such a trouble occurs. This not only requires unnecessary washing time, but also causes an overload on the motor.

Further, when the washing and dewatering tub is rotated by using a DC brushless motor controlled by an inverter device, a bubble is generated because the torque is larger than that of the conventional condenser run type induction motor. However, the rotational speed does not decrease and the detection of the rotational speed cannot detect the bubble restraint, so that the motor may be overloaded and cause a failure or the like.

According to the present invention, an increase in the washing time is prevented by controlling so as to prevent the occurrence of foam restraint, or by controlling so as to detect and avoid foam restraint promptly. It is an object of the present invention to provide a washing machine that prevents an overload of the washing machine.

[0007]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a washing machine for rotating, washing, rinsing and spinning a washing and dewatering tub in which laundry is put. Performing a first rinsing and a second dehydration and having a period during which the washing and dewatering tub is rotated at a maximum first rotation speed during the first dehydration, and wherein the washing and dewatering tub is rotated during the second dehydration. Has a period during which the motor rotates at a second rotation speed equal to or higher than the first rotation speed.

According to this configuration, the washing and dewatering tub rotates at a relatively high first rotation speed after washing, and the laundry containing a lot of foam is dehydrated. Next, rinsing is performed, and the laundry that does not contain much foam is dehydrated at the rotation speed of the washing and dewatering tub that is higher than the first rotation speed.

[0009] The present invention also provides a low-speed rotation speed lower than the first rotation speed before the washing and dewatering tub rotates at the first rotation speed during the first and second spin-drying. A rotation period, wherein the low-speed rotation period during the first dehydration is longer than the low-speed rotation period during the second dehydration.

According to this structure, the first dehydration is performed after the washing, and the washing and dehydrating tub is switched from the low rotation speed to the high first rotation speed, so that the laundry containing much foam is dehydrated.
Next, after the rinsing is performed, the second dehydration is performed, and the washing and dewatering tub is switched from a low rotation speed to a higher rotation speed than the first rotation speed, so that the laundry containing much foam is dewatered. You.
At this time, the low-speed rotation period during the first dehydration is longer than the low-speed rotation period during the second dehydration.

Further, the present invention has a washing amount detecting means for detecting an amount of the laundry in the washing and dewatering tub, and the low-speed rotation period at the time of the first and second dehydration is automatically determined by the amount of the laundry. It is set to be automatically. According to this configuration, at the time of washing, the amount of laundry is detected in advance by the laundry amount detection unit. Then, optimal low-speed spin times during the first and second spin-dry times obtained experimentally according to the amount of laundry are extracted from the database, and spin-dry at low spin speed is performed at that time.

Further, the present invention includes a setting means for allowing a user to set the low-speed rotation period during the first and second spin-drying. According to this configuration, the optimal first and second low-speed spin times during dehydration obtained experimentally according to the amount and type of the laundry are extracted from the database and displayed, and the user selects appropriate conditions. Then, the spinning at a low speed is performed in that time.

According to the present invention, in a washing machine in which a washing and dewatering tub into which laundry is put is rotated for washing, rinsing, and dewatering, current detecting means for detecting a current flowing to a motor for rotating the washing and dewatering tub. When the current value at the time of dehydration is equal to or more than a predetermined value, the rotation of the washing and dewatering tub is stopped, and after the water in the washing and dewatering tub is drained, dehydration or rinsing is performed.

According to this configuration, the fact that the bubbles are trapped during the dewatering is detected by the current flowing to the motor for rotating the washing and dewatering tub, the washing and dewatering tub is stopped, and after the drainage, the rinsing step or the dewatering step is performed again. Will be

Further, the present invention provides a washing and dewatering tub into which laundry is put, and a current detecting means for detecting a current flowing to a motor for rotating the washing and dewatering tub in a washing machine for washing, rinsing and spinning. The motor is stopped for a predetermined stop time when the current value during dehydration is equal to or more than a predetermined value.

According to this configuration, it is detected at an early stage that the bubbles are trapped during the dehydration by the current flowing to the motor for rotating the washing and dewatering tub, and the motor is stopped to perform the washing without applying a load to the motor. The dehydration tank is rotated by inertia to perform the dehydration step. At this time, the number of revolutions of the washing and dewatering tub decreases in accordance with the resistance of the foam restraint, so that the generation of foam is suppressed and the generated foam is discharged out of the water tub, so that the foam restraint is released after a predetermined time has elapsed.

According to another aspect of the present invention, in a washing machine in which a washing and dewatering tub into which laundry is put is rotated to wash, rinse, and spin, current detecting means for detecting a current flowing to a motor for rotating the washing and dewatering tub. When the current value at the time of dehydration is equal to or more than a predetermined value, the rotation speed of the motor is maintained or reduced.

According to this configuration, it is detected at the initial stage that the bubbles are trapped during dehydration by the current flowing through the motor that rotates the washing and dehydrating tub, and the rotational speed of the motor is maintained or reduced to load the motor. The spin-drying tub is rotated without applying the water to perform the spin-drying step. At this time, the generation of bubbles is suppressed and the generated bubbles are discharged out of the water tank, so that after a suitable time has elapsed, the restriction of the bubbles is released.

Further, according to the present invention, an alarm is issued when the current value is equal to or more than the predetermined value after a predetermined driving time elapses by maintaining or decreasing the rotation speed of the motor. According to this configuration, it is detected in the initial stage that the foam is trapped during dehydration by the current flowing to the motor that rotates the washing and dehydrating tub, and the rotational speed of the motor is maintained or reduced to apply no load to the motor. The spin-drying tub is rotated to perform the spin-drying process. Thereafter, an alarm is issued if the current does not decrease even after a predetermined drive time has elapsed.

The present invention also provides a washing and dewatering tub for stopping the motor for a predetermined stop time when the current value is equal to or greater than the predetermined value after a predetermined driving time has elapsed after maintaining or decreasing the rotation speed of the motor. Is rotated by inertia.

According to this configuration, the fact that the bubbles are trapped during the dewatering is detected at an early stage by the current flowing through the motor that rotates the washing and dewatering tub, and the rotation speed of the motor is maintained or reduced to load the motor. The spin-drying tub is rotated without applying the water to perform the spin-drying step. Thereafter, if the current does not decrease even after a predetermined driving time has elapsed, the motor is stopped and the washing and spin-drying tub is rotated by inertia without applying a load to the motor to perform the spin-drying step. At this time, the number of revolutions of the washing and dewatering tub is reduced according to the resistance of the foam restraint, so that the generation of foam is suppressed and the generated foam is discharged out of the water tub, so that the foam restraint is eliminated after a predetermined stop time elapses. You.

Further, the present invention has a washing amount detecting means for detecting an amount of the laundry in the washing and dewatering tub, and the stop time is automatically set according to the washing amount. According to this configuration, the stop time is determined by extracting an appropriate stop time from a database obtained experimentally in advance based on the amount of laundry obtained from the washing amount detecting means.

In the present invention, the rotation speed of the motor is maintained or reduced, and after a predetermined driving time has elapsed, when the current value is equal to or greater than the predetermined value, the rotation of the washing / dewatering tub is stopped to stop the rotation. The water in the tank is drained and then dehydrated or rinsed.

According to this configuration, it is detected at the initial stage that the bubbles are trapped during dehydration by the current flowing through the motor that rotates the washing and dewatering tub, and the rotation speed of the motor is maintained or reduced to apply a load to the motor. The spin-drying tub is rotated without applying the water to perform the spin-drying step. Thereafter, when the current does not decrease even after a predetermined driving time has elapsed, the rotation of the washing and dewatering tub is stopped, and the water in the washing and dewatering tub is drained and then dewatered or rinsed.

According to the present invention, the rinsing method is a water rinsing. According to this configuration, it is detected in the initial stage that the foam is trapped during dehydration by the current flowing to the motor that rotates the washing and dehydrating tub, and the rotational speed of the motor is maintained or reduced to apply no load to the motor. The spin-drying tub is rotated to perform the spin-drying process. Thereafter, when the current does not decrease even after a predetermined driving time has elapsed, the rotation of the washing and dewatering tub is stopped, the water in the washing and dewatering tub is drained, and then water rinsing is performed.

[0026]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a washing machine according to the present invention will be described with reference to a side sectional view shown in FIG. In FIG. 1, a washing machine 30 is covered with an outer case 1, and a water tub 2 is suspended and fixed by an anti-vibration mechanism 3 inside the outer case 1, and a washing and dewatering tub 4 is provided inside the water tub 2. Is provided.
A motor 7 is provided below the water tank 2, and rotation of the motor 7 is transmitted to a center pulley 11 via a motor pulley 9 and a V-belt 10.

The tip of the mechanism 8 connected to the center pulley 11 projects into the water tub 2, and the stirring blade 5 and the washing and dewatering tub 4 are attached. The washing and dewatering tub 4 is switched so as to rotate during the spinning. Above the motor 7, a rotation speed detecting device 23 for detecting the rotation speed of the motor 7 is provided.

A drain port 2a is provided at the lower end of the water tank 2, and a drain valve 13 and a drain hose 14 are attached. The upper part of the outer box 1 is covered with a top plate 19. Behind the upper surface plate 19, a water level sensor 17 connected to the water tank 2,
A water supply valve 18 for supplying water to the water tank 2 is provided, and an operation unit 20 is provided in front of the water supply valve 18. The operation unit 20 includes a control circuit 21
Is attached to the back side of the upper plate 19.

FIG. 2 shows a control circuit 2 of the washing machine 30.
1 is a block diagram illustrating a control method according to Example 1. In the figure, the same members as those in FIG. 1 are denoted by the same reference numerals.
According to the figure, when the course of the washing condition is set from the button input unit 24 provided on the operation unit 20, the control circuit 21
The washing is performed in accordance with a program in which the microcomputer 22 is installed. The information of the water level sensor 17 is sent to the microcomputer 22 and the switching means 27 controls opening and closing of the water supply valve 18 and the drain valve 13.

Further, information on the number of revolutions of the motor 7 is sent from the revolution number detecting device 23 to the microcomputer 22, and the inverter control device 26 can control the number of revolutions of the motor 7 based on a control signal from the microcomputer 22. It has become. At this time, the current flowing through the motor 7 by the current detection device 28 is sent to the microcomputer 22. A DC brushless motor is used as the motor 7, and the duty cycle (= W / T) is changed by changing the pulse width W or period T of the drive signal, and the voltage applied by pulse width modulation is controlled to rotate. The number can be controlled.

In such a washing machine 30, when the user puts laundry into the washing and dewatering tub 4 and operates a start switch (not shown) provided on the operation unit 20, the stirring blade 5 is driven by the motor 7. Spin at low speed. At this time, if the amount of laundry is large, the load on the motor 7 is large.
The amount of the laundry can be determined by detecting the current flowing through the washing device by the current detecting means 28. When the motor 7 is a capacitor run type induction motor, the amount of laundry can be determined by the rotation speed detecting device 23, and the amount of laundry can be determined by measuring the weight of the laundry.

Next, when the water supply valve 18 is opened to supply water to the water tub 2 and water is supplied to an appropriate water level according to the washing amount described above, the water supply valve 18 is closed, and the stirring blade 5 is driven in reverse to wash for 1-2 minutes. The stirring blade 5 is stopped. Thereafter, the water level in the water tub 2 is detected by the water level sensor 17, and the quality of the laundry is determined based on the amount of decrease in the water level. When clothes such as cotton are large in the laundry, the water absorption rate is high and the water level is largely lowered. However, when clothes such as synthetic fibers are large, the water absorption rate is small and the water level is small. Accordingly, the laundry quality is determined, and a washing time, a rinsing time, and a dehydration time suitable for the amount of the laundry and the laundry quality are determined, and the laundry is performed.

At the time of spin-drying, the rotation of the motor 7 drives the washing and spin-drying tub 4, and the rotation speed of the washing and spin-drying tub 4 is controlled as shown in FIG. In FIG. 3, the vertical axis indicates the number of rotations of the washing and dewatering tub 4, and the horizontal axis indicates the dewatering time. According to the figure, two stages of low-speed rotations x1, x for one dehydration are shown.
2 are performed for periods t1 and t2, respectively, and the high-speed rotation speed x3
After the dehydration is performed for the time t3, the motor 7 is stopped, and the washing and dewatering tub 4 is rotated by the inertia and stopped.

FIG. 4 shows a dehydration step after washing (hereinafter referred to as "dehydration one step") and a dehydration after the first rinsing when the number of revolutions of the washing and dewatering tub 4 is controlled by a control method as shown in FIG. The conditions of the step (hereinafter referred to as “two steps of dehydration”) are shown. In the dehydration 1 step, the first and second low-speed rotation speeds x1 and x2
Are 250 rpm and 500 rpm, and the high-speed rotation speed × 3
Is 800 rpm. In the two dehydration steps, the first and second low-speed rotations x1 and x2 are 300 rpm and 600 rpm, and the high-speed rotation x3 is 1000 rpm.

As described above, when the high-speed rotation speed x3 (800 rpm) is reduced in the one step of dehydration in which the laundry contains the detergent, the generation of bubbles can be suppressed, and the generation of the restraint of the bubbles can be reduced. At the time of the two steps of dehydration, since almost no detergent remains in the laundry, the high-speed rotation speed x3 is increased to improve the dehydration effect. As shown in FIG. 5, the same effect can be obtained by rotating temporarily at the same high speed as the high speed x3 in the second spin-drying process or at a higher speed near the end of the high-speed spin period t3 in the first spin-drying process. . In FIG. 5, the vertical axis indicates the number of revolutions of the washing and dewatering tub 4, and the horizontal axis indicates the dewatering time.

In FIG. 5, the low-speed rotation speeds x1, x2 (250, 5), which are lower than the high-speed rotation speed x3 in one dehydration process, are shown.
If the periods t1 and t2 of (00 rpm) are lengthened to about 50 seconds, the water containing the detergent is dehydrated while suppressing the generation of bubbles, and the generation of the restriction of bubbles can be reduced. At the time of the two steps of dehydration, as in the above, almost no detergent remains in the laundry, so the high-speed rotation speed of one step of dehydration x 3 (800 rpm)
Lower speeds x1 ', x2' (300, 60
Even if the periods t1 ′ and t2 ′ of 0 rpm) are shortened to about 30 seconds, no bubble restriction occurs, and the washing time can be reduced.

As described above, the conditions of the dehydration step automatically determined by judging the amount of laundry and the quality of the laundry are as follows:
For example, conditions as shown in FIG. 6 are set. FIG. 6 (a) shows the dehydration conditions when the laundry is a small amount of synthetic fiber with a small amount of water absorption, and FIG. 6 (b) shows the dehydration conditions when the laundry is full with a large amount of water absorption such as cotton. I have.

In the case of synthetic fibers with a small amount of laundry and a small amount of water absorption, foam binding is less likely to occur than in the case of cotton with a large amount of laundry and a large amount of water absorption. The periods t1 and t2 of the low-speed rotations x1 and x1 may be shortened to about 30 to 20 seconds, and the washing time can be reduced. Also in this case, the high-speed rotation speed x3 is dehydrated 1
During the process, the speed is reduced to 800 rpm,
By making 1 and t2 longer in the first step of dehydration than in the second step of dehydration, the occurrence of bubble constraint is suppressed.

Further, the user may select a previously stored dehydration condition as shown in FIG. 7 using the operation unit 20 (see FIG. 1). FIG. 7A shows the dehydration conditions in the “standard course” of the standard clothing, and FIG. 7B shows the dehydration conditions in the “blanket course” when the amount of water absorption is extremely large such as a blanket or a futon. Alternatively, the dehydration conditions as shown in FIG. 6A may be selected by a name such as “short course”.

In the "blanket course", since a large amount of water is absorbed, a large amount of the detergent remains after washing, so that the foam is likely to be restrained. For this reason, the periods t1 and t of the low-speed rotation in the two dehydration processes
2 to about 60 seconds, and 75
By increasing the length to 90 seconds, the occurrence of bubble restraint is suppressed.

Next, during dewatering of the washing machine shown in FIG. 1 described above, a method of avoiding the case where the bubble is still restrained even if the rotation speed and the low-speed rotation time of the washing and dewatering tub 4 are optimized as described above. Will be described. When the bubble restraint occurs, the DC brushless motor has a large torque, so that the rotation speed does not decrease. However, the value of the current flowing through the motor 7 detected by the current detecting means 28 (see FIG. 2) becomes higher than the current value when no overload is applied, so that the occurrence of bubble restraint can be detected. ing.

In order to avoid the occurrence of the bubble restraint, the rotation speed of the washing and dewatering tub 4 is reduced when the rotation speed of the washing and dewatering tub 4 is high. The number of revolutions is further reduced according to the load. This allows the already generated foam to be drained out of the water tub 2 without increasing the amount of foam generated by the rotation of the washing and dewatering tub 4. When the load on the motor 7 is reduced and the current flowing through the motor 7 decreases, the program returns to the original program to perform dehydration (hereinafter, referred to as “first avoidance method”).

Further, upon detecting the bubble restraint, the power supply to the motor 7 is stopped, and the washing and dewatering tub 4 is rotated by the inertia force at a rotation speed corresponding to the resistance due to the bubble restraint. (Hereinafter referred to as “second avoidance method”). At this time, it is not possible to determine whether or not the bubble restraint has been canceled because no current is flowing through the motor 7, so the stop time of the motor 7 can be set based on data stored in advance according to the amount of laundry and the type of fabric. realizable.

Further, upon detecting the foam restriction, the rotation of the washing and dewatering tub 4 may be stopped, and the dewatering may be performed again after draining (hereinafter referred to as a "third avoidance method"). The rotation of 4 may be stopped, rinsed again after drainage, and dewatering may be performed (hereinafter, referred to as “fourth avoidance method”). At this time, the rinsing step may be performed in addition to the original program, or if there is a next rinsing step, the program may be skipped to the next rinsing step and the subsequent dehydration step may be performed. Further, the effect of eliminating the bubble constraint can be further improved by rinsing with water (hereinafter, referred to as “fifth avoidance method”).

In any of the first to fifth avoidance methods, the original program is executed when the current flowing through the motor 7 decreases or a predetermined time elapses, thereby avoiding bubble restraint. The load on the motor 7 can be reduced, and the process does not stop abnormally during the washing, so that the user is not anxious.

If the first avoidance method can eliminate the slight bubble restraint and return to the original program, the motor 7 is not stopped, so that time loss is small. Therefore, if the first avoidance method is performed first, and then any of the second to fifth avoidance methods is continuously performed only when the bubble constraint cannot be avoided, the efficiency can be efficiently increased according to the degree of the bubble constraint. It is possible to eliminate bubble restraint. This prevents the washing time from becoming unnecessarily long. Also in this case, whether or not the bubble restraint has been eliminated can be detected by the value of the current flowing through the motor 7.

Further, when the current value of the motor 7 does not decrease after the first avoidance method is performed and the bubble is in the confined state, the method is switched to another avoidance method, and an alarm is generated to cause an abnormality to occur to the user. Is alerted to the user, and when the motor is overloaded in addition to the restraint of the foam, the user can take an abnormal measure, which is desirable.

[0048]

According to the first aspect of the present invention, it is possible to suppress the occurrence of foam restraint by suppressing the maximum number of revolutions of the washing and dewatering tub at the time of dehydration in a state where the detergent still remains. Overload can be prevented.

According to the second aspect of the present invention, by increasing the low-speed rotation time of the washing and dewatering tub during dewatering while the detergent is still left, it is possible to suppress the occurrence of foam restraint, and to overload the motor. Can be prevented.

According to the third aspect of the present invention, since the conditions for dehydration are automatically set in accordance with the amount of the laundry, the occurrence of foam restraint is suppressed, and the washing time is prevented from becoming unnecessarily long.

According to the fourth aspect of the present invention, since the conditions for dehydration are set by the user in accordance with the amount of the laundry, the occurrence of foam restraint is suppressed, and the washing time is prevented from becoming unnecessarily long.

According to the fifth aspect of the present invention, even when a DC brushless motor or the like having a large torque is used when the bubble restraint occurs, the bubble restraint can be detected by the current flowing through the motor. As a result, the rotation of the washing and dewatering tub is stopped, and dewatering or rinsing is performed after drainage to avoid foam restraint, thereby preventing overload of the motor.

According to the sixth aspect of the invention, even when a DC brushless motor or the like having a large torque is used when the bubble restraint occurs, the bubble restraint can be detected by the current flowing through the motor. As a result, the overload of the motor can be prevented by stopping the power supply to the motor and rotating the washing and dewatering tub by inertia according to the resistance of the foam restraint to avoid the foam restraint.

According to the seventh aspect of the invention, even when a DC brushless motor or the like having a large torque is used when the bubble restraint occurs, the bubble restraint can be detected by the current flowing through the motor. As a result, the rotation speed of the washing and dewatering tub is maintained or reduced to easily avoid the bubble restraint, thereby preventing the motor from being overloaded and preventing the washing time from becoming unnecessarily long.

According to the eighth aspect of the present invention, when the number of rotations of the washing and dewatering tub is not maintained or reduced, it is possible to alert the user when bubbles cannot be avoided and eliminate the cause by the user.

According to any one of the ninth to twelfth aspects of the present invention, only when the number of rotations of the washing and dewatering tub cannot be avoided even if the rotation speed of the tub is maintained or reduced, another avoiding means is continuously performed. Washing can be performed with a minimum necessary washing time.

[Brief description of the drawings]

FIG. 1 is a side view showing a washing machine of the present invention.

FIG. 2 is a block diagram showing control of the washing machine of the present invention.

FIG. 3 is a diagram illustrating a method for controlling a spin-drying step of the washing machine according to the present invention.

FIG. 4 is a diagram showing dehydration conditions of the washing machine of the present invention.

FIG. 5 is a diagram illustrating a method for controlling a spin-drying step of the washing machine of the present invention.

FIG. 6 is a view showing dehydrating conditions of the washing machine of the present invention.

FIG. 7 is a diagram showing dehydration conditions of the washing machine of the present invention.

[Explanation of symbols]

 2 Water tank 4 Washing and dewatering tank 7 Motor 13 Drain valve 19 Water supply valve 20 Operation unit 21 Control circuit 23 Rotation speed detection device

Claims (12)

[Claims] 1. A washing machine for rotating, washing, rinsing and dehydrating a washing and dehydrating tub into which laundry is put, wherein the first dehydrating, the first rinsing and the second dehydrating are performed after the washing and the first dehydrating is performed. During the dehydration, the washing and dewatering tub has a period in which the washing and dewatering tub is rotated at the maximum first rotation speed, and in the second dehydration, the washing and dewatering tub is rotated at the second rotation speed that is equal to or more than the first rotation speed A washing machine having a period. 2. A low-speed rotation period in which the washing and dewatering tub rotates at a rotation speed lower than the first rotation speed before the washing and dewatering tub rotates at the first rotation speed during the first and second spin-drying. The washing machine according to claim 1, wherein the low-speed rotation period during the first dehydration is longer than the low-speed rotation period during the second dehydration. 3. A washing amount detecting means for detecting an amount of the laundry in the washing and spin-drying tub, wherein the low-speed rotation period during the first and second spin-drying is automatically set according to the amount of the laundry. The washing machine according to claim 1 or 2, wherein the washing is performed. 4. The washing machine according to claim 1, further comprising setting means for allowing a user to set the low-speed rotation period during the first and second spin-drying. 5. A washing machine for rotating, washing, rinsing, and spinning a washing and dewatering tub into which laundry is put, wherein the washing and dewatering tub has current detecting means for detecting a current flowing to a motor for rotating the washing and dewatering tub. A washing machine wherein the rotation of the washing and dewatering tub is stopped when the current value at the time of dehydration is equal to or more than a predetermined value, and then the water in the washing and dewatering tub is drained and then dewatered or rinsed. 6. A washing machine for rotating, washing, rinsing and spinning a washing and dewatering tub into which laundry is put, wherein the washing and dewatering tub has current detecting means for detecting a current flowing to a motor for rotating the washing and dewatering tub. A washing machine wherein the motor is stopped for a predetermined stop time when the current value at the time of dehydration is equal to or more than a predetermined value, and the washing and dewatering tub is rotated by inertia. 7. A washing machine for rotating, washing, rinsing and spinning a washing / dewatering tub into which laundry is put, wherein the washing / dehydrating tub has current detecting means for detecting a current flowing to a motor for rotating the washing / dewatering tub. A washing machine for maintaining or decreasing the rotation speed of the motor when the current value during dehydration is equal to or greater than a predetermined value. 8. The washing machine according to claim 7, wherein an alarm is issued when the current value is equal to or more than the predetermined value after a predetermined driving time elapses after maintaining or decreasing the rotation speed of the motor. . 9. After a predetermined driving time elapses after maintaining or decreasing the rotation speed of the motor, when the current value is equal to or more than the predetermined value, the motor is stopped for a predetermined stop time, and the washing and dewatering tub is driven by inertia. The washing machine according to claim 7, wherein the washing machine is rotated. 10. A washing amount detecting means for detecting an amount of laundry in the washing and dewatering tub, wherein the stop time is automatically set according to the amount of washing. Item 10. A washing machine according to item 9. 11. After a predetermined driving time elapses after maintaining or decreasing the rotation speed of the motor, when the current value is equal to or more than the predetermined value, the rotation of the washing and dewatering tub is stopped, and The washing machine according to claim 7, wherein dewatering or rinsing is performed after draining the water. 12. The washing machine according to claim 5, wherein the rinsing method is a water rinsing.