JPH11319363A - Washing machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable a small and inexpensive capacitor induction motor to satisfy both of a spray washing system and an agitation washing system of a washing machine, which is equipped with a system to rotate a washing and dehydrating tub to bring up washing upward by centrifugal force and to spray waster into the washing and dehydrating tub and a system to wash washing by agitation of a pulsator, by making the capacitor induction motor to drive the pulsator or the washing and dehydrating tub produce the optimum torque for each system. SOLUTION: A pulsator 2 rotatably equipped with a washing and dehydrating tub 3 or the washing and dehydrating tub 3 is driven by a capacitor induction motor 7. A control means has a first process to rotate the pulsator 2 to wash and a second process to rotate the washing and dehydrating tub 6 equipped 3 to spray washing water from between a water receiver tank cover on the upper part of the water receiving tank 1 and the washing and dehydrating tub 3 to wash and changes capacity of the capacitor of the capacitor induction motor 7 in the first process and the second process.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of rotating a washing and dewatering tub to lift a washing liquid upward by centrifugal force and spraying water into the washing and dewatering tub, and a method of washing by stirring a pulsator. The present invention relates to a washing machine equipped with a washing machine.

[0002]

2. Description of the Related Art Conventionally, a washing machine rotates laundry in a washing and dewatering tub via water or by rotating a pulsator by directly contacting the laundry. Although the agitation method using the pulsator has a high detergency, there is a problem that the laundry is damaged because the laundry directly contacts the pulsator.

The inventor has developed a method of rotating a washing / dewatering tub to lift the washing liquid upward by the centrifugal force and sprinkling water into the washing / dewatering tub so as not to damage the laundry to be washed. We have proposed a combined washing machine that has both a washing method with high washing power and a new washing method that does not damage the laundry, and that can be used properly according to the laundry.

[0004]

However, when the pulsator or the washing and dewatering tub of this combined washing machine is driven by a condenser induction motor, the performance required of the condenser induction motor is to rotate the conventional pulsator. In the system, a large torque is required at a relatively high rotation speed, whereas in the system for rotating the washing and dewatering tub, a large torque is required at a low rotation speed. In order to satisfy both of these characteristics, a large capacitor induction motor is required, resulting in a problem that the cost is increased.

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems. A capacitor induction motor for driving a pulsator or a washing and dewatering tub is designed to generate an optimum torque for each system. It aims to satisfy the function of the method.

[0006]

According to the present invention, in order to achieve the above object, a washing and dewatering tub is rotatably disposed in a water receiving tub, and a pulsator is rotatably mounted on the bottom of the washing and dewatering tub. And a pulsator or a washing and dewatering tub is driven by a condenser induction motor. The control means controls the condenser induction motor and the like, performs a first step of washing by rotating the pulsator, and a washing and dewatering tub to rotate the washing and dewatering tub to provide a water receiving tub cover provided above the water receiving tub. A second step of sprinkling the washing liquid into the washing and dehydrating tub from between the water tanks and washing the laundry; and changing the capacitor capacity of the capacitor induction motor between the first step and the second step. Things.

[0007] Thereby, the capacitor induction motor for driving the pulsator or the washing and dewatering tub is designed to produce the optimum torque for each system, and the functions of both types can be satisfied with a small and inexpensive capacitor induction motor. it can.

[0008]

According to a first aspect of the present invention, there is provided a water receiving tank, a water receiving tank cover provided on the upper part of the water receiving tank, and a rotatably disposed water receiving tank. A washing and spin-drying tub, a pulsator rotatably disposed on the bottom surface of the washing and spin-drying tub, a capacitor induction motor for driving the pulsator or the washing and spin-drying tub, and control for controlling the capacitor induction motor and the like. Means for rotating the pulsator to perform washing in a first step, and rotating the washing and dewatering tub to rotate the washing and dewatering tub from between the water receiving tub cover and the washing and dewatering tub, and A second step of sprinkling the washing liquid to wash the washing machine, wherein the first step and the second step are configured to change the capacitance of the capacitor of the capacitor induction motor. Demand for capacitor induction motor The relatively large torque at a high rotational speed and the large torque at a low speed required for the capacitor induction motor in the second stroke can be satisfied with a small capacitor induction motor, and the first stroke can be performed at low cost. And a system for driving the second stroke.

According to a second aspect of the present invention, in the first aspect of the present invention, the control means includes:
Is connected between a main winding and an auxiliary winding of a capacitor induction motor, and in a second step, a second predetermined capacitance is additionally connected to the first predetermined capacitance. Therefore, the capacitor having the second predetermined capacitance requires only a small capacitance, and the drive system can be constructed at low cost.

According to a third aspect of the present invention, in the second aspect of the present invention, the control means changes the second predetermined capacity according to the power supply frequency. , The required torque can be satisfied in the first and second strokes.

According to a fourth aspect of the present invention, in accordance with the first aspect of the present invention, there is provided a rotational speed detecting means for detecting a rotational speed of the capacitor induction motor, and the control means includes a step of: The drive power of the induction motor is controlled in phase or on / off to control the rotation speed to a predetermined rotation speed.Even if the power supply frequency or power supply voltage changes, the capacitor induction motor rotates at the predetermined rotation speed. Therefore, a certain amount of water can be secured.

According to a fifth aspect of the present invention, in the fourth aspect of the present invention, there is provided a water level detecting means for detecting a water level in a water receiver, and a cloth amount for detecting an amount of laundry in a washing and dewatering tub. Detecting means, and the control means changes the predetermined number of revolutions of the condenser induction motor based on at least one of information on a water level in the water receiving tub and an amount of laundry in the washing and dewatering tub. It is possible to maintain a constant level of watering even if the water level in the water receiving tub or the amount of laundry in the washing and dewatering tub changes, and to maintain the cleaning performance in the second step at a constant level. In addition, the amount of foam generated in the washing and dewatering tub can be suppressed to a predetermined amount or less.

[0013]

Embodiments of the present invention will be described below with reference to the drawings.

(Embodiment 1) As shown in FIG. 1, a water receiving tub 1 includes a washing and dewatering tub 3 in which a pulsator 2 is rotatably arranged at the bottom, and a washing machine outer frame is provided by hanging rods 4. Hanging on 5 A water receiving tank cover 6 is provided above the water receiving tank 1
The washing and dewatering tub 3 is rotated, and the washing liquid that has risen between the washing and dewatering tub 3 and the water receiving tub 1 is sprinkled into the washing and dewatering tub 3 in a waterfall manner.

A condenser induction motor (hereinafter referred to as a motor) 7 drives the pulsator 2 or the washing and dewatering tub 3 via a V-belt 8 and a speed reduction mechanism / clutch 9. The rotation speed of the motor 7 is controlled by the control device 10. The drain valve 11 drains the washing liquid in the washing and dewatering tub 3, and the water supply valve 12 supplies water to the washing and dewatering tub 3. The upper part of the washing and dewatering tub 3 is covered with a lid 13. The laundry 14 is put into the washing / dewatering tub 3.

The control device 10 is configured as shown in FIG. 2, and the control means 15 sequentially controls the respective steps of washing, rinsing and dehydration based on the setting contents inputted by the operation display means 16. The power switching means 17
, The motor 7, the drain valve 11, the water supply valve 12, and the like are sequentially controlled. The storage unit 18 stores data and the like necessary for the sequential control by the control unit 15.

The drive means 19 drives the opening / closing means 20 based on a command from the control means 15. The opening / closing means 20 is
A second predetermined capacitor 22 is connected or disconnected in parallel with the first predetermined capacitor 21.
The capacitor 21 having the first predetermined capacity is connected between the main winding and the auxiliary winding of the motor 7. Reference numeral 23 denotes a commercial power supply, and 24 denotes a power switch of the washing machine.

The operation of the above configuration will be described. The washing machine according to the present invention includes a first step of rotating the pulsator 2 to wash the laundry, and a step of rotating the washing and dewatering tub 3 to rotate the washing and dewatering tub 3 from between the water receiving tub cover 6 and the washing and dewatering tub 3. There is a second step of sprinkling the washing liquid into the dewatering tub 3 and washing the laundry by passing the washing liquid.

In the case of a very dirty laundry such as jeans, the laundry is washed in the first step, and in the case of a delicate and lightly stained laundry, the laundry is washed in the second step. The process to be used can be selected depending on the type. In addition, a course in which the first and second steps are mixed for underwear and the like is also prepared.

In such a washing machine, the performance required for the motor 7 depends on the case where the pulsator 2 is driven for washing and the case where the washing and dewatering tub 3 is driven for sprinkling water from the upper part for washing. Will be different. FIG. 3 shows the relationship between the rotational speed and the torque among the required motor performances. In FIG. 3, a characteristic curve a is a representative characteristic (speed-torque characteristic) of the motor that rotates the pulsator 2.

First Rotating Pulsator 2 for Washing
In the case of the stroke, it is necessary to rotate the pulsator 2 at a rotation speed of about 140 r / min and a torque of 20 to 25 N · m. In order to realize this, the rotation speed of the motor 7 is reduced to 1.7: 1 by the V-belt 8 and reduced to 6: 1 by the reduction mechanism / clutch 9. Therefore, the motor 7
It must be operated at about 1400 r / min, 2 Nm.
The operation is performed at the point P1 of the characteristic curve a in FIG.

On the other hand, in the case of the second step of washing by rotating the washing and dewatering tub 3, the washing and dewatering tub needs to be rotated at a rotation speed of about 140 r / min with a torque of 5 N · m.
When the belt is decelerated to 1.7: 1, the characteristic required of the motor 7 is about 3 N · m at about 240 r / min. The operation is performed at the point P2 in FIG. However, as is clear from FIG. 3, the torque is insufficient in the characteristic curve a, so that the driving cannot be performed.

As a method for compensating for this, a characteristic curve c that satisfies both points P1 and P2 by increasing the motor 7
There is a method to obtain the characteristics of According to this method, the performance is sufficiently satisfied, but the size of the motor 7 is slightly larger and the cost is greatly increased.

The inventors paid attention to the fact that the characteristics can be changed by changing the capacitor capacity of the motor 7, and were able to increase the capacitor capacity and change the characteristic of the characteristic curve a to the characteristic curve b. As a result, the point P2 can be satisfied, so that the second step of rotating and washing the washing / dewatering tub 3 can be executed.

However, in the case of the characteristic curve b, when the rotational speed is 1400 r / min, the torque reaches the point P3, which is far short of the point P1, and the pulsator 2 cannot wash. Therefore, the first
A method of operating the washing machine by switching the capacitor capacity and switching the characteristic of the motor 7 between the characteristic curve a and the characteristic curve b in FIG. 3 between the time of executing the step and the time of executing the second step is established. did.

In order to switch the characteristic of the motor 7 from the characteristic curve a to the characteristic curve b, the capacitance of the capacitor always increases. Therefore, when the first stroke is performed, the first predetermined capacitance of the motor 7 is reduced. When the capacitor 21 is connected between the main winding and the auxiliary winding of the motor 7 to execute the second stroke, the opening / closing means 20 changes the capacitor 22 having the second predetermined capacity into the capacitor 21 having the first predetermined capacity. Additional connection to.

As described above, by connecting / disconnecting the small-capacity capacitor 21 having the second predetermined capacity by the opening / closing means 20, a motor having a commonly used size can be used in the first stroke and the second stroke. The second step can be performed, and a high value-added washing machine capable of performing the second step can be manufactured with only a small cost added to the conventional washing machine.

(Embodiment 2) The control means 15 shown in FIG.
The second predetermined capacity is changed according to the power supply frequency. Other configurations are the same as those in the first embodiment.

The operation of the above configuration will be described. FIG. 4 shows the rotation speed and torque characteristics of the motor 7 of the present embodiment. The characteristic curves a and b are the characteristics at 50 Hz, and the characteristic curves c, d and e are the characteristics at 60 Hz. The characteristic curves a and c show the case where the capacitor 21 having the first predetermined capacitance is connected between the main winding and the auxiliary winding of the motor 7, and the characteristic curves b and d show that the second predetermined capacitor 21 has the second predetermined capacitance. Capacitor 2 of predetermined capacity
2 is additionally connected, a characteristic curve e is a characteristic in a case where a capacitor having a third predetermined capacitance is additionally connected to the first predetermined capacitor 21 instead of the capacitor 22 having the second predetermined capacitance.

First, the first step of washing the laundry by rotating the pulsator 2 and the washing and dewatering tub 3 are rotated to rotate the washing and dewatering tub 3 between the water receiving tub cover 6 and the washing and dewatering tub 3. In the case where the second step of sprinkling the washing liquid into the washing liquid and washing the laundry by passing the washing liquid is executed, when the power supply frequency is 50 HZ, the characteristic curve of FIG. The first step is executed at point P1 of a, and the second step is executed at point P2 of the characteristic curve b.

Next, when the power supply frequency is 60 Hz,
When the power supply frequency changes, the characteristic curves a and b change like the characteristic curves c and d. By the way, point P
The torque of the characteristic curve c at the rotation speed n2 of 1 is the point P
1 and there is no problem in executing the first stroke, but the torque of the characteristic curve d at the rotation speed n1 at the point P2 is insufficient at the point P2, and the second stroke cannot be executed. .

Therefore, in this embodiment, the characteristic curve e is obtained by replacing the capacity of the capacitor 22 with the second predetermined capacity with the increased third capacity, and the torque at the point P2 is secured. As described above, by changing the capacitance of the second predetermined capacitor according to the power supply frequency, it is possible to easily cope with the power supply frequency.

In this embodiment, the capacitor having the third predetermined capacity is replaced with the capacitor having the third predetermined capacity instead of the capacitor having the second predetermined capacity. May be added.

(Embodiment 3) As shown in FIG. 5, the control means 26 constituting the control device 25 sequentially performs each of the washing, rinsing and dewatering steps based on the setting contents inputted by the operation display means 27. The motor 7, the drain valve 11, the water supply valve 12, and the like are sequentially controlled via the power switching means 28. The storage unit 29 stores data and the like necessary for the sequential control by the control unit 26.

The drive means 30 drives the opening / closing means 31 based on a command from the control means 26. The opening / closing means 31
A second predetermined capacitor 22 is connected or disconnected in parallel with the first predetermined capacitor 21.
The capacitor 21 having the first predetermined capacity is connected between the main winding and the auxiliary winding of the motor 7.

The motor 7 is provided with a rotation detecting means 32 for detecting the number of rotations. The output of the rotation detecting means 32 is counted by a rotation number counting means 33 for a predetermined time and is inputted to the control means 26. In the second step, the control means 26 controls the phase of the drive power source of the motor 7 to control the rotation speed to a predetermined rotation speed. Other configurations are the same as those in the first embodiment.

The operation of the above configuration will be described. The rotation speed of the motor 7 changes depending on the frequency of the power supply, the voltage, and the load of the motor. Originally, it is preferable to control the rotation speed of the motor 7 to a predetermined rotation speed in all the operations of the washing machine. However, for that purpose, control of an inverter or the like is required, which is too costly and expensive. Therefore, it is preferable to control the minimum number of rotations at the minimum.

Then, the washing and dewatering tub 3 is rotated to rotate the washing and dewatering tub 3 from between the water receiving tub cover 6 and the washing and dewatering tub 3.
The number of revolutions of the motor 7 is controlled only in the second step in which the washing liquid is sprinkled inside and the laundry is washed by passing the washing liquid.
As a result, the object was almost achieved only by controlling the number of revolutions near a predetermined value by the phase control. It was also confirmed that practically compromised control could be achieved by on-off control of about 1 second instead of phase control.

By adopting these simple controls, it is possible to make the structure inexpensive while securing the cleaning performance.

(Embodiment 4) As shown in FIG. 6, the control means 35 constituting the control device 34 sequentially executes each of the washing, rinsing and dewatering steps based on the setting contents inputted by the operation display means 36. The motor 7, the drain valve 11, the water supply valve 12, and the like are sequentially controlled via the power switching means 37. The storage unit 38 stores data and the like necessary for the sequential control by the control unit 34.

The drive means 39 drives the opening / closing means 40 based on a command from the control means 35. The opening / closing means 40 is
A second predetermined capacitor 22 is connected or disconnected in parallel with the first predetermined capacitor 21.
The capacitor 21 having the first predetermined capacity is connected between the main winding and the auxiliary winding of the motor 7.

The motor 7 is provided with a rotation detecting means 32 for detecting the number of rotations. The output of the rotation detecting means 32 is counted by a rotation number counting means 41 for a predetermined time and is inputted to a control means 35. Further, the rotation number counting means 41 inputs the data at the time of detecting the cloth amount to the cloth amount detecting means 42, and outputs the data to the cloth amount detecting means 42.
Inputs the determined amount of the laundry in the washing and dewatering tub 3 to the control means 35. The water level detecting means 43 detects and determines the water level of the water receiving tank 1 and inputs the same to the control means 35.

The control means 35 changes the predetermined number of revolutions of the motor 7 based on at least one of the water level in the water receiving tub 1 and the amount of the laundry in the washing and dewatering tub 3. Other configurations are the same as those in the first embodiment.

The operation of the above configuration will be described. The characteristics of the amount of washing liquid sprinkling when the washing and spinning tub 3 is rotated in the second step will be described. FIG. 7 shows the relationship between the number of rotations of the washing and spinning tub 3 and the amount of washing liquid sprinkling. The characteristic curve a is for a high water level, the characteristic curve b is for a medium water level, and the characteristic curve c is for a low water level. As is clear from FIG. 7, the amount of washing liquid sprinkled varies depending on the water level, but the amount of sprinkled washing liquid can be controlled by the number of rotations.

FIG. 8 shows the relationship between the amount of laundry (cloth amount) in the washing and dewatering tub 3 and the amount of washing liquid sprinkled when the rotation speed of the washing and dewatering tub 3 is kept constant. The characteristic curve a is for a high water level, the characteristic curve b is for a middle water level, and the characteristic curve c is for a low water level. Thus, the amount of water sprayed with the washing liquid is a function of the amount of cloth and the water level.

By the way, the greater the amount of washing liquid sprinkled, the better in terms of detergency. Conversely, in order to prevent the adverse effects of foaming in the washing and dewatering tub 3, it is necessary to suppress the amount of sprinkling to a predetermined amount. The predetermined watering amount varies depending on the water level, the amount of cloth, the quality and amount of dirt, the type and amount of detergent, the water temperature, and the like. The predetermined watering amount when the dirt is light at the middle water level and the detergent water temperature is standard is shown in FIG. w
It is displayed as 1.

When this w1 is compared with the characteristic curve b of the middle water level, it is necessary to control the rotation speed of the washing and dewatering tub 3 between the cloth amounts n1 and n2 since the water spray amount exceeds the w1. When the amount of cloth is n2 or more, there is no bubble problem, but the cleaning power is reduced. Therefore, it is necessary to increase the number of revolutions so that the amount of sprayed washing liquid approaches w1.

In this embodiment, the control amount is determined experimentally, the table is written into the storage means 38, and the control means 35 controls the information of the rotation number counting means 41 and the cloth amount detection means 4
Then, the information of the water level detecting means 43 is compared with the information of the table and the switching timing is instructed to the power switching means 37 to control the washing water spray amount to be w1.

As described above, it is extremely important to determine the level of the predetermined watering amount. In the present embodiment, the quality and amount of the stain, the type and amount of the detergent, and the water temperature are determined as the conditions under which bubbles are most likely to occur. The water level is changed with the water level information and the cloth amount information. Originally, it is better to change the level of the prescribed watering amount with all information, but the minimum control is preferable when considering cost performance, and the inventors control with the water level and the cloth amount By establishing a system, it was possible to control the amount of washing water sprinkling to ensure a predetermined detergency by preventing the adverse effects of foam generation with minimum cost.

[0050]

As described above, according to the first aspect of the present invention, the water receiving tank, the water receiving tank cover provided on the upper part of the water receiving tank, and the water receiving tank rotating inside the water receiving tank. A washing and dewatering tub freely disposed, a pulsator rotatably disposed on the bottom of the washing and dewatering tub, a capacitor induction motor for driving the pulsator or the washing and dehydration tub, the condenser induction motor, and the like. A first step of rotating the pulsator for washing, and a step of rotating the washing and dewatering tub to wash between the water receiving tub cover and the washing and dewatering tub. A second step of sprinkling the washing liquid into the spin-drying tub and washing the water; washing is performed in the first step and the second step so that the capacitor capacity of the capacitor induction motor is changed; The process and the second
The torque required for the capacitor induction motor in the process of
Can be satisfied with a small capacitor induction motor,
A system that drives the first and second strokes at low cost can be realized.

According to the second aspect of the present invention, the control means connects the capacitor having the first predetermined capacity between the main winding and the auxiliary winding of the capacitor induction motor in the first step. In the second step, the second predetermined capacitance is additionally connected to the capacitor having the first predetermined capacitance. Therefore, the capacitor having the second predetermined capacitance has a small capacitance, and the drive system can be constructed at a low cost. it can.

According to the third aspect of the present invention, in the second aspect of the present invention, the control means changes the second predetermined capacity according to the power supply frequency.
Even if the power supply frequency changes, the required torque can be satisfied in the first stroke and the second stroke.

According to a fourth aspect of the present invention, there is provided a rotation speed detecting means for detecting a rotation speed of the capacitor induction motor, and the control means controls the drive power of the capacitor induction motor in the second stroke. Since the rotation speed is controlled to a predetermined rotation speed by phase control or on / off control, even if the power supply frequency or the power supply voltage changes, the capacitor induction motor rotates at the predetermined rotation speed, so that a constant amount of watering is performed. Can be secured.

According to the fifth aspect of the present invention, there is provided a water level detecting means for detecting a water level in a water receiver, and a cloth amount detecting means for detecting an amount of laundry in a washing and dewatering tub. The control means changes the predetermined number of revolutions of the condenser induction motor based on at least one of the water level in the water receiving tub and the amount of the laundry in the washing and dewatering tub. Even if the water level and the amount of laundry in the washing and dewatering tub change, the watering amount can be kept constant, and the washing performance in the second step can be kept at a constant level. The generation amount of bubbles in the inside can also be suppressed to a predetermined amount or less.

[Brief description of the drawings]

FIG. 1 is a sectional view of a washing machine according to a first embodiment of the present invention.

FIG. 2 is a block circuit diagram of the washing machine.

FIG. 3 is a characteristic diagram of a condenser induction motor of the washing machine.

FIG. 4 is a characteristic diagram of a condenser induction motor of a washing machine according to a second embodiment of the present invention.

FIG. 5 is a block circuit diagram of a washing machine according to a third embodiment of the present invention.

FIG. 6 is a block circuit diagram of a washing machine according to a fourth embodiment of the present invention.

FIG. 7 is a characteristic diagram showing the relationship between the number of revolutions of the washing and dewatering tub of the washing machine and the amount of washing liquid sprinkled.

FIG. 8 is a characteristic diagram showing a relationship between a cloth amount, a water level, and a washing liquid sprinkling amount of the washing machine.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Water receiving tank 2 Pulsator 3 Washing and dewatering tank 6 Water receiving tank cover 7 Condenser induction motor 15 Control means

Claims (5)

[Claims] 1. A water receiving tank, a water receiving tank cover provided on an upper portion of the water receiving tank, a washing and dewatering tank rotatably disposed in the water receiving tank, and a bottom surface of the washing and dewatering tank. A pulsator rotatably disposed on the pulsator, a condenser induction motor for driving the pulsator or the washing and dewatering tub, and control means for controlling the condenser induction motor and the like, wherein the control means rotates the pulsator. A first step of washing and washing, and a second step of rotating the washing and spin-drying tub and sprinkling the washing liquid into the washing and spin-drying tub from between the water receiving tub cover and the washing and spin-drying tub to wash. A washing machine comprising: a first step and a second step configured to change a capacitor capacity of the capacitor induction motor. The control means connects a capacitor having a first predetermined capacity between a main winding and an auxiliary winding of a capacitor induction motor in a first stroke, and sets a second predetermined capacity in a second stroke. The washing machine according to claim 1, wherein the washing machine is configured to be additionally connected to the capacitor having the first predetermined capacity. 3. The washing machine according to claim 2, wherein the control means changes the second predetermined capacity according to a power supply frequency. 4. A method according to claim 1, further comprising a rotation speed detecting means for detecting a rotation speed of the capacitor induction motor, wherein the control means includes:
2. The washing machine according to claim 1, wherein the drive power of the condenser induction motor is controlled in phase or on / off to control the rotation speed to a predetermined rotation speed. 5. A washing machine comprising: a water level detecting means for detecting a water level in a water receiver; and a cloth amount detecting means for detecting an amount of laundry in the washing and dewatering tub; 5. The washing machine according to claim 4, wherein the predetermined number of revolutions of the condenser induction motor is changed based on at least one of the information on the amount of the laundry in the washing and dewatering tub.