JP2001340689A - Washing machine and detergent feeding method thereof - Google Patents

Abstract

(57) [Summary] PROBLEM TO BE SOLVED: To make the washing effect of a detergent evenly and easily to all of the laundry in a tub, and to prevent the detergent from being melted and remaining on the laundry without being melted until after the operation. To SOLUTION: The bath is rotated during the time when the detergent is fed from the detergent feeding device, so that the detergent is sprayed inside the bath (S5 to S9). In addition, during the time when the detergent is introduced, water is supplied by the water supply means, and the detergent is supplied into the tank by the water (S4). Further, the rotation of the tub during the detergent input time is performed at a rotation speed lower than the steady rotation speed of the tub during the dehydration operation and lower than the resonance rotation speed of the internal mechanism (S5).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a washing machine having a detergent feeding device and a method for supplying the detergent.

[0002]

2. Description of the Related Art Conventionally, a washing machine has been provided with a detergent feeding device. This detergent feeding device automatically feeds a detergent into the inside of a washing tub, and the put detergent is supplied to one place in the washing tub.

[0003]

According to the above-mentioned prior art, when the detergent is supplied to one portion in the washing tub, the detergent is apt to be left undissolved, and the washing effect of the detergent is reduced by the washing effect in the washing tub. There is a problem that it is difficult to evenly spread the objects, and uneven washing is likely to occur. In addition, there is a problem that the undissolved detergent may remain on the laundry without dissolving until the end of the operation in some cases, thereby impairing the washing effect.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object the main purpose of the present invention is to make it possible for the detergent effect to be uniformly applied to all the laundry in the tub.
An object of the present invention is to provide a washing machine and a method for supplying the detergent, which can reduce washing unevenness and prevent the detergent from being dissolved and remaining on the laundry without being melted until the end of the operation.

[0005]

In order to achieve the above object, a washing machine according to the present invention contains a tub for storing laundry, washing the stored laundry, and dewatering the tub, and a dehydrating tub. A water supply means for supplying water to the inside thereof, and a detergent feeding device for automatically and gradually feeding a detergent into the inside of the tank, and by rotating the tank during the time for feeding the detergent, the tank is A detergent is sprayed in the inside (the invention of claim 1). According to this, since the detergent can be sprayed into the inside of the tub, the cleaning effect of the detergent easily and evenly spreads over all the laundry in the tub. In addition, undissolved detergent is less likely to occur.

[0006] In this case, it is more preferable to supply water by a water supply means during the time when the detergent is charged, and to supply the detergent into the tank with the water (the invention of claim 2).
In this case, the detergent introduced from the detergent introduction device can be supplied into the tank while being dissolved in water.

It is preferable that the rotation of the tub during the detergent input time is performed at a lower rotation speed than the steady rotation speed of the tub during the dehydration operation (the invention of claim 3). In this case, it is possible to conveniently spray the detergent on the inside of the tank by appropriate rotation of the tank.

Further, it is preferable that the rotation of the tank during the detergent introduction time is performed at a rotation speed lower than the resonance rotation speed of the internal mechanism (the invention of claim 4). In this case, it is possible to spray the detergent on the inside of the tank while avoiding resonance of the internal mechanism.

A rotating stirrer, a clutch mechanism for switching the transmission of the driving force of the rotary stirrer between the stirrer and the stirrer;
A drain valve for draining water from the inside of the tank; and a common actuator for operating the drain valve and operating the clutch mechanism, and the actuator operates the clutch mechanism and the drain valve in a stepwise manner. It is preferable to do so (the invention of claim 5). In this case, the rotation of the tank during the detergent input time can be performed by the common actuator without opening the drain valve.

[0010] A detergent supply method for a washing machine according to the present invention comprises: a tub for storing laundry, washing the stored laundry, and dewatering; a water supply means for supplying water to the inside of the tub; And a detergent feeding device that automatically feeds a detergent into the inside of the container, and by rotating the tank during the time for feeding the detergent, the detergent is sprayed inside the tank. (The invention of claim 6). According to this method, the same operation as the washing machine of the first aspect can be obtained.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. First, FIG. 2 shows the appearance of a washing machine with a detergent supply device. An outer box 1 and a top cover 2 mounted on the top of the outer box 1 constitute an outer shell of the washing machine body. 1 is provided with a tank 3. This tub 3 is both a washing tub and a dehydration tub, and an outer tub 4 elastically supported and disposed inside the outer box 1.
As shown in FIG. 4, the laundry (not shown) is rotatably driven by a motor 5 (also shown in FIG. 4) which is a rotary drive source. Has become. A washing stirrer (also not shown) is disposed inside the tub 3 and is rotated by the motor 5 in the normal and reverse directions to wash the laundry. ing.

On the other hand, the top cover 2 has a tank 3
A laundry doorway 6 facing the inside is formed, and for example, a two-fold lid 7 is provided to the laundry doorway 6 so as to be openable and closable. An operation panel 8 for operating the washing machine is provided at the front of the top cover 2, and a back cover 9 is provided at the rear. Further, on the rear surface of the outer box 1, both legs 10a of a stand 10 on which a clothes dryer can be installed are mounted on both left and right sides.

Further, a detergent introduction device 11 is attached to the back cover 9. As shown in detail in FIG. 3, the detergent charging device 11 has an outer case 13 around the hopper 12, and the claws 14, 15 formed on the lower left and right sides of the outer case 13 are backed. Claw hooks 1 formed on both right and left sides of detergent inlet 12 of cover 9
It is detachably attached to the back cover 9 by elastically engaging the members 7 and 18, respectively.

A detergent agitator 19 having a large number of projections is rotatably supported in the lower part of the hopper 12 of the detergent introduction device 11 so as to be rotatable on the horizontal axis. A detergent delivery body 20 is provided at the lower part. The detergent delivery body 20 is composed of a coil, in particular, a coil whose diameter gradually increases from the base end portion on the left side in the drawing to the middle portion, and is straight from the middle portion to the tip portion on the right side in the drawing. One of the projections of the detergent agitator 19 is engaged with the middle part of the body. Accordingly, when the detergent delivery body 20 is rotated, the detergent stirring body 19 is also rotated by sequentially feeding the projections engaged with the detergent delivery body 20 in accordance with the rotation.

Further, the lower end of the hopper 12 has a detergent outlet 21 at the right end in the figure, and the tip of the detergent delivery body 20 is located inside the outlet 21. The detergent outlet 21 is provided with a stopper 22 as an opening / closing member, and the stopper 22 can be rotated left and right by an opening / closing drive device (not shown) provided at the back of the hopper 12 and mainly composed of a motor. Is opened and closed.

On the other hand, the lower end of the hopper 12 has a bearing portion 24 at the left end in the figure, and a shaft 25 integrated with the base end portion of the detergent delivery body 20 is located inside the bearing portion 24. I have. A driven gear 26 is provided on the left side of the shaft 25 opposite to the detergent delivery body 20 side in the figure, and a driving gear 27 that meshes with the driven gear 26 and transmits a rotational force is attached to a rotating shaft of a motor 28. ing.

The motor 28 is disposed at a mounting base portion 29 located at a rear upper portion of the tub 3 and at a portion behind the laundry entrance 6 of the top cover 2, particularly at a left end portion in the drawing. In addition, the mounting base 29
A water supply pump 30, a water supply valve 31, and a water injection case 32 are disposed as water supply means for supplying water into the tank 3.

Here, the water supply pump 30 is provided with a motor 34 and an impeller 35 that is driven to rotate by the motor 34 inside a pump case 33. A water intake port that absorbs water by the rotation of the impeller 35 is provided. 36, and a water outlet (not shown) for discharging the absorbed water, of which the water inlet 36 is exposed upward from the back cover 9.

The water supply valve 31 has one water inlet 37 at an upper part and two first and second water outlets 38 and 39 at a front part thereof. 38, and from the water inlet 37 to the second water outlet 39.
A three-way valve that switches the opening of the flow path to the drive port by the driving force of a drive source such as a solenoid or a motor is provided.
Are exposed upward from the back cover 9.

The water injection case 32 is for injecting the water supplied by the water supply pump 30 and the water supply valve 31 into the tank 3, and only a part thereof is shown in FIG. It has a waterway to which the water outlet communicates, a waterway to which the first water outlet 38 of the water supply valve 31 communicates, and a waterway to which the second water outlet 39 communicates, of which the first water outlet 3 of the water supply valve 31 is provided.
The water flowing through the water channel 8 is indicated by an arrow A in FIG.

The water injection case 32 is formed with a detergent passage 40 located below the detergent outlet 21 of the detergent introduction device 11, and a first water outlet of the water supply valve 31 is formed below the detergent passage 40. Water flows through a water channel through which the water flows.

In addition, in addition to the water channel through which the water outlet of the water supply pump 30 communicates and the water channel with which the second water outlet 39 of the water supply valve 31 communicates, the outlet is connected with the first water outlet 38 of the water supply valve 31. It is the same as the open channel and faces the inside of the tank 3.

Also, at the common outlet of those waterways,
A drawer 41 is attached so as to be able to be taken in and out from the front and rear. The drawer 41 has a storage portion for storing a washing auxiliary agent, for example, a soft finish, particularly in a water channel through which the second water outlet 39 of the water supply valve 31 communicates. And the stored soft finish is poured out by the water flowing through the water channel, for example, by a siphon method.

FIG. 4 shows the structure of the outer bottom of the water tank 4, and the motor 5 is arranged at the center of the outer bottom of the water tank 4. The motor 5 is, for example, an outer rotor type DC brushless motor that is controlled by an inverter, and has a clutch mechanism 42 therein, and the transmission of the driving force of the motor 5 is performed by the clutch mechanism 42 in the tub 3 (dehydration). Operation) and the stirring body (washing operation). In addition, an actuator for switching the clutch mechanism 42 as described above, in this case, a geared motor 43 and a switching lever mechanism 44 are disposed at the outer bottom of the water tank 4.

In addition, the outer bottom of the water tank 4 is provided with the tank 3
Drain valve 45 for draining water from the inside of the vehicle, an actuator for operating the drain valve 45, and a geared motor 46
And a coupling mechanism 47. FIG. 5 shows a control device 48 functioning as control means for controlling the overall operation of the washing machine, which is constituted by, for example, a microcomputer.

The control unit 48 includes the operation panel 8
In addition to input of operation signals from various operation switches 49 included in the above, a water level detection is input from a water level sensor 50 which is a water level detection means for detecting a stored water level in the tank 3. A rotation detection signal is inputted from a rotation sensor 51 which is a rotation detecting means for detecting the rotation of 5, and for example, a dirt detection signal is output from a dirt sensor 52 which detects the degree of contamination of the washing water at the drain valve 45 by the degree of light transmission. A water temperature detection signal is also input from a water temperature sensor 53 that detects the temperature of the washing water at the drain valve 45 as well.

Based on the above-mentioned various inputs and control programs stored in advance, the control unit 48 controls the various display units 54 of the operation panel 8, the drive source 31 a of the water supply valve 31, and the water supply pump 30. Motor 3
4, motor 5, geared motor 4 for clutch mechanism 42
3. A drive control signal is supplied to a geared motor 46 for the drain valve 45 and a drive circuit 55 for driving the motor 28 of the detergent dispenser 11.

Next, the operation of the above configuration will be described. First, before using the washing machine, the water inlet 37 of the water supply valve 31 is used.
And a water tap (not shown) are connected by a water supply hose (also not shown). When washing with the remaining hot water (bath water) of the bath, one end of a water absorption hose (not shown) is connected to the water inlet 36 of the water supply pump 30, and the other end of the water absorption hose is connected to a bathtub (not shown). Immerse in water. Further, a detergent (powder) for a plurality of washings is put in the hopper 12 of the detergent dispenser 11, and the lid 56
Close.

In this state, laundry (not shown) is put in the tub 3, the lid 7 is closed, and the operation of the washing machine is started.
Then, as shown in FIG. 1, the control device 48 first measures the laundry amount (step S1). The measurement of the amount of laundry is performed, for example, by a method in which a predetermined input is made to the motor 5 to rotate the stirring body in the tub 3 and the rotation speed of the motor 5 at this time is detected by the rotation sensor 51. The required water level is determined from the measurement results (step S2),
The supply amount of the detergent is determined (step S3).

Thereafter, the first water is supplied through the water inlet 37 of the water supply valve 31.
By opening the flow path to the water outlet 38, water is supplied into the tank 3 through the water channel of the water injection case 32 through which the first water outlet 38 communicates (step S4). Then, in this state, the clutch mechanism 42 is switched and the tank 3 is rotated by the motor 5 (step S5).

The rotation of the tank 3 is, for example, 50 [rpm].
The rotation speed is lower than the steady rotation speed (for example, 900 [rpm]) of the tank 3 during the spin-drying operation, and the resonance rotation speed of the internal mechanism (for example, 2 rpm).
The rotation speed is lower than 00 to 300 [rpm].
In this case, the internal mechanism includes an outer tank 4 having elastic support, a tank 3 attached thereto, a motor 5, and geared motors 43 and 4.
6, the drain valve 45, the elastic support mechanism, and the like. These resonances are caused by the spring constant of the spring of the elastic support mechanism, the outer tub 4, the tub 3, the motor 5, the geared motor 43,
46, a drain valve 45, etc., which are generated at a resonance frequency determined by the mass of the whole supported by the elastic support mechanism, and the resonance rotation speed is a rotation speed at which the resonance occurs.

Thereafter, from the detection result of the water level sensor 10,
It is determined whether or not the detected water level Kw is equal to or greater than a predetermined value R (step S6). This determination is for determining whether or not water has entered the tank 3, and the predetermined value R is an extremely low water level, and as soon as it is determined that the water level is equal to or greater than the predetermined value R, the detergent is automatically determined. Injection is started (step S7).

The automatic introduction of the detergent is performed by the detergent introduction device 11.
Is opened by an open / close drive device (not shown), and the motor 28 is operated in that state. When the motor 28 is operated, the driving gear 27
The rotational force in the coil screwing direction is transmitted to the detergent sending body 20 through the hopper 1 and the detergent sending body 20 rotates.
The detergent put in the container 2 is automatically sent out little by little, that is, gradually from the detergent outlet 21 as shown by an arrow B in FIG.

Then, the sent out detergent flows into the detergent inlet 4 of the water injection case 32 located below the detergent outlet 21.
The water further flows down through the channel 7 into the channel below, is dissolved in the water flowing through the channel as described above, and is injected into the tank 3 from the outlet of the water injection case 32 together with the water. At this time, tank 3
Is rotated at the above-described rotation speed of, for example, 50 [rpm], whereby the detergent is sprayed in the tank 3.

At this time, in the hopper 12, the detergent agitating body 19 is rotated with the rotation of the detergent delivery body 20, so that the detergent in the hopper 12 is loosened.
In addition, the supply of such a detergent depends on the supply amount determined from the previous measurement result of the laundry amount, the detection result of the laundry dirt by the dirt sensor 52, the detection result of the water temperature by the water temperature sensor 53, and the like. , Is performed with the contents supplied the optimal amount.

After the supply of the optimum amount of detergent is completed, the motor 28 is stopped, and the stopper 22 is closed by an opening / closing drive (not shown) to terminate the automatic supply of detergent (step S8). .

Thereafter, the motor 5 is also stopped to stop the rotation of the tank 3 (step S9), and the process proceeds to the next step. Subsequent steps include the termination of water supply, execution of a washing (washing and rinsing) operation, execution of a dehydration operation, and the like.

In the case where the washing operation is performed with bath water (bath water course), after step S9, the supply of tap water (from the water inlet 37 of the water supply valve 31 to the first water supply port) is performed until the water supply ends.
Instead of opening the flow path to the water outlet 38 of
By activating the water supply pump 30, the bath water is sucked up from the bathtub through the water absorption hose, and the water supply pump 3
Bath water is supplied into the tank 3 through the water channel of the water injection case 32 through which the water outlet of No. 0 communicates.

Further, when the last rinsing stroke of the plurality of executions is reached, the water supply valve 31 opens the flow path from the water inlet 37 to the second water outlet 39 at this time. The water supplied from the tap of the water supply through the water supply valve 31 is supplied to the water channel of the water injection case 32 through the second water outlet 39 of the water supply valve 31 and the drawer 4 set in this water channel.
It is injected into the tank 3 through the storage unit 1. Therefore, at this time, if a washing auxiliary agent, for example, a soft finish is put in the storage portion of the drawer 41, the stored soft finish agent is injected into the tub 3 together with the water passing through the storage portion.

As described above, in this configuration, the tank 3 is rotated during the time when the detergent is automatically and gradually introduced into the inside of the tank 3 by the detergent introduction device 11, whereby the detergent is supplied to the tank 3. Will be sprayed inside. Therefore, compared with the conventional one in which the detergent is supplied to one place in the tub, the cleaning effect of the detergent is easily applied to all of the laundry in the tub 3, and unevenness in washing can be reduced. Tank 3
The detergent that is sprayed inside is less likely to remain undissolved, so that the detergent does not melt and remains on the laundry without dissolving until the end of operation, and the washing effect due to the remaining residue of the detergent The problem of spoiling can be eliminated.

During the time when the detergent is charged, water is supplied by a water supply valve 31 and a water injection case 32 which are water supply means, and the detergent is supplied into the tank 3 by the water. The detergent supplied from the charging device 11 is
The detergent can be supplied into the tank 3 while being dissolved in water, so that the detergent remains undissolved and remains unremoved.
Moreover, in this case, the washing effect of the detergent on the laundry in the tub 3 can be promptly exhibited.
The stirring time for washing can be shortened, so-called cloth damage and cloth entanglement can be suppressed, and desired washing performance can be obtained.

Further, the rotation of the tank 3 during the detergent introduction time is performed at a rotation speed lower than the steady rotation speed of the tank 3 during the dehydrating operation. Since the detergent can be satisfactorily sprayed on the inside of the tub 3, the cleaning effect of the detergent can be more uniformly applied to all the laundry in the tub 3, and the washing unevenness can be further reduced. or,
In this case, it is possible to prevent the detergent supplied into the tank 3 from splashing and jumping out of the tank 3, so that the cleaning effect by the detergent can be fully exhibited. Further, in this case, it is possible to prevent the water in the tank 3 from splashing.

In addition, the rotation of the tank 3 during the detergent injection time is as follows:
The cleaning is performed at a rotation speed lower than the resonance rotation speed of the internal mechanism, whereby the detergent can be sprayed on the inside of the tank 3 while preventing the internal mechanism from causing resonance.

In addition, in the present configuration, the motor 5 is controlled by an inverter, so that, for example, even when the tank 3 is rotated at a low speed as described above when the detergent is supplied, the induction motor is controlled to be energized. The motor 5 can be operated quietly without generating a beating sound of the motor 5 as in the case where the motor 5 is rotated at a low speed.

The detergent is supplied from the detergent supply device 11 in a situation where it is determined that water has entered the tank 3. Otherwise, the detergent is supplied from the detergent supply device 11. Since the water supply is not performed, it is possible to prevent the detergent from being input by mistake when the water tap is closed.

6 to 8 show a second embodiment of the present invention. The same parts as those in the first embodiment are denoted by the same reference numerals, and their description will be omitted. Only the part will be described. In this case, the switching lever 61 for switching the clutch mechanism 42 (not shown in FIGS. 6 to 8) is connected to the wire 62, the connection frame 63, and the wire 64.
In this order, the geared motor 65 in this case as well.
And a switching lever 67 for switching (opening / closing) the drain valve 45 via a wire 66 is engaged with the geared motor 65 side (opposite the switching lever 61 side) of the connection frame 63.

In this configuration, the geared motor 65 pulls the wire 64 in two stages. By pulling the wire at the first stage, as shown in FIG. The switching lever 61 is rotated, whereby the clutch mechanism 42 is operated, and the motor 5
Is transmitted to the tank 3. At this time, the connection frame 63 is pulled by a distance that does not rotate the switching lever 67 for the drain valve.

Then, as shown in FIG. 8, the switching lever 67 is rotated by the connecting frame 63 by pulling in the next stage.
Thus, the drain valve 45 is opened. At this time, the switching lever 61 for the clutch mechanism is further rotated.
To be communicated to

That is, in this case, the clutch mechanism 42 and the drain valve 45 are connected to the common actuator 1
The motors 65 are operated in a stepwise manner.
In this case, the actuator is connected to two as in the first embodiment.
That is, the tank 3 can be rotated by the common actuator during the detergent introduction time without opening the drain valve 45 (state in FIG. 7). Therefore, not only is there no waste of water supply, but especially it can be realized with a reduced number of parts, and the product price can be reduced.

In addition, the present invention is not limited to the embodiment described above and shown in the drawings. In particular, as a washing machine, the horizontal axis or the oblique axis is used instead of the vertical axis type tub 3. It may be a drum type washing machine having a drum, and the rotation of the tub 3 during the introduction of the detergent is not limited to the entire time during the introduction of the detergent.
For example, it may be a part of the time and may be changed as appropriate without departing from the scope of the invention.

[0051]

The present invention is as described above.
The following effects are obtained. The washing machine according to claim 1, and claim 6.
According to the detergent supply method of the washing machine, the detergent introduced from the detergent introduction device can be sprayed into the inside of the tub, so that the washing effect by the detergent can be easily spread evenly on all the laundry in the tub, and the washing unevenness can be achieved. In addition, the detergent can be prevented from melting and remaining on the laundry without melting until after the operation is completed.

According to the second aspect of the present invention, the detergent introduced from the detergent introduction device can be supplied into the tub while being dissolved in water, so that the undissolved and unattached detergent can be eliminated more reliably. The cleaning effect by the detergent can be promptly exhibited.

According to the washing machine of the third aspect, the detergent can be sprayed on the inside of the tub by the proper rotation of the tub, so that the washing effect by the detergent is more evenly distributed to all the laundry in the tub. And unevenness in washing can be further reduced.
Further, in this case, it is possible to prevent the detergent supplied into the tank from splashing and jumping out of the tank, and also prevent the water in the tank from splashing.

According to the washing machine of the fourth aspect, it is possible to spray the detergent on the inside of the tub while avoiding resonance of the internal mechanism. According to the washing machine of claim 5, with the actuator common to the clutch mechanism and the drain valve, rotation of the tub during the detergent input time can be performed without opening the drain valve,
Therefore, not only is there no waste of water supply, but also it can be realized with a reduced number of parts.

[Brief description of the drawings]

FIG. 1 is a flowchart illustrating an operation of a first embodiment of the present invention.

FIG. 2 is an overall perspective view.

FIG. 3 is a longitudinal sectional front view of a main part.

FIG. 4 is a cutaway bottom view of the internal mechanism.

FIG. 5 is a block diagram of an electrical configuration.

FIG. 6 is a bottom view of a mechanism showing a second embodiment of the present invention.

FIG. 7 is a bottom view showing a first stage operation state of a mechanism portion.

FIG. 8 is a bottom view showing a next stage operation state of the mechanism portion.

[Explanation of symbols]

3 is a tank, 5 is a motor (rotary drive source), 11 is a detergent injection device, 31 is a water supply valve (water supply means), 32 is a water injection case (water supply means), 42 is a clutch mechanism, 45 is a drain valve, and 61 is a switch. Lever, 63 is a connection frame, 65 is a geared motor (actuator), and 67 is a switching lever.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Koji Kuno, Inventor 991 Anada-cho, Seto-shi, Aichi Prefecture Toshiba Corporation Aichi Factory (72) Inventor Shoji Wada 991, Anada-cho, Seto-shi, Aichi Prefecture Toshiba Corporation Inside the Aichi Plant (72) Inventor Morimasa Komatsu 991 Anada-cho, Seto-shi, Aichi F-term in the Ashi Plant, Toshiba 3B155 AA17 AA21 BB08 CA06 GB05 GB09 HB10 KA02 KA12 KA15 KA19 LA02 LA11 LB02 LB04 LB18 LB29 LB31 LB34 LC07 LC08 LC28 MA01 MA02 MA06 MA08

Claims (6)

[Claims] 1. A tub for storing laundry, washing the stored laundry, and dewatering, water supply means for supplying water to the inside of the tub, and automatically supplying a detergent to the inside of the tub. A washing machine, comprising: a detergent feeding device for gradually feeding the detergent; and rotating the tub during the time for feeding the detergent to spray the detergent inside the tub. 2. The washing machine according to claim 1, wherein water is supplied by a water supply means during a period when the detergent is charged, and the detergent is supplied into the tub by the water. 3. The washing machine according to claim 1, wherein the rotation of the tub during the detergent introduction time is performed at a lower rotation speed than the steady rotation speed of the tub during the dehydration operation. 4. The washing machine according to claim 1, wherein the rotation of the tub during the detergent introduction time is performed at a rotation speed lower than a resonance rotation speed of the internal mechanism. 5. A stirrer for washing is provided inside the tub, a rotary drive source, a clutch mechanism for switching transmission of the driving force of the rotary drive source between the tub and the stirrer, and drainage from the inside of the tub. A drain valve for operating the clutch mechanism and operating the drain valve in a stepwise manner by operating the drain valve and the clutch mechanism. Item 7. The washing machine according to Item 1. 6. A tub for storing laundry, washing the stored laundry and dewatering, a water supply means for supplying water to the inside of the tub, and automatically supplying a detergent to the inside of the tub. A detergent supply method for a washing machine, comprising: a detergent supply device for supplying the detergent; and rotating the tub during the time for supplying the detergent to spray the detergent into the tub.