JP2000342883A - Washing machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To shorten time for disentangling and rearranging eccentric laundry when starting dehydration. SOLUTION: At the time of dehydration after the end of washing or rinsing in water, a spinning tub 5 ad a pulsator 7 are integrally rotated at low speed without draining water used for washing or rinsing. Since non-uniformity rotation occurs when the laundry is positioned eccentrically inside the spinning tub 5, a pulse signal synchronous to the rotation of a motor 8 is provided by a rotation sensor added to the motor 8, and a speed change amount during one rotation of the spinning tub 5 is calculated from that pulse signal. The level of an eccentric load is judged on the basis of that speed change amount, and when it is judged the eccentric load is abnormally great, the laundry is moved and disentangled under water by rotating the spinning tub 5 or pulsator 7 on a prescribed procedure. When it is judged the eccentric load is a little, drainage is performed by opening a drain valve 15, and afterwards, dehydration is executed by rotting the spinning tub 5 at high speed. Thus, since water supply or drainage is not required in the case of disentangling operation, time and water can be economized.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a washing machine, and more particularly, to control for starting a spin-drying operation in a spiral washing machine.

[0002]

2. Description of the Related Art In a general spiral type fully automatic washing machine, a bottomed cylindrical outer tub is suspended and supported by a suspension rod for absorbing vibration, and a number of dehydration holes are formed inside the outer tub. A washing and dewatering tub is disposed rotatably. During the spin-drying operation, the spin-drying tub is rotated at a high speed (for example, about 1000 rpm), and the centrifugal force causes water to be discharged from the laundry contained in the spin-drying tub and scattered to the outer tub side through the spin-drying hole. I do.

If the laundry is unevenly distributed around the rotating shaft of the washing / dewatering tub and there is a so-called eccentric load, when the washing / dewatering tub is rotated, a swinging vibration is generated, and the outside of the washing / drying tub is extremely shaken. The tank comes into contact with the housing and generates loud noise. As a device for detecting such abnormal vibration in a conventional washing machine, a safety lever is swingably supported on an upper surface plate of a housing so as to have a predetermined gap with an outer peripheral surface of an outer tub in a normal state. When the outer tub swings greatly during the spin-drying operation and comes into contact with the safety lever, a switch attached to the safety lever is turned off, whereby abnormal vibration of the outer tub is detected.

[0004] Further, in the conventional general washing machine, when it is detected that abnormal vibration occurs during the spin-drying operation as described above, the spin-drying operation is interrupted in order to eliminate uneven distribution of the laundry. Relaxing driving is performed. Specifically, the rotation of the washing and dewatering tub is stopped, the drain valve is closed, a predetermined amount of water is supplied into the washing and dewatering tub, and the pulsator (stirring blade) is rotated to move the laundry in the water. .
After performing the loosening operation for a predetermined time, the water stored in the washing and dewatering tub is discharged, and the dehydration operation is tried again.

[0005]

The above-mentioned conventional washing machine has the following problems. In the case of the abnormal vibration detection method described above, the allowable range of the position of the safety lever, the dimensional accuracy, the sensitivity of the switch, the shape of the contact portion between the outer tank cover and the safety lever, and the like are small. The switch is activated, and the washing time may be unnecessarily prolonged. Conversely, the switch may not operate well despite the large vibration, and the outer tub may come into strong contact with the housing to generate loud noise.

Further, in recent years, the gap between the outer tub and the housing has been further narrowed due to large capacity and space saving, and the outer tub is likely to contact the housing even with a relatively small eccentric load. For this reason, measures such as molding the housing with a special material using cushioning materials have been taken to prevent the generation of loud impact noise even when the outer tub contacts the housing. Had contributed.

Further, if abnormal vibration occurs during the spin-drying operation, the laundry is rearranged in the order of water supply → loose operation → drainage, thereby significantly increasing the washing time. Therefore, in order to shorten the washing time, it is important to shorten the time required for the loosening operation as much as possible even when it is necessary to perform the loosening operation.

The present invention has been made in order to solve such problems, and a first object of the present invention is to provide a case where it is necessary to perform a loosening operation to eliminate uneven distribution of laundry during a spin-drying operation. Another object of the present invention is to provide a washing machine capable of suppressing an increase in washing time. A second object of the present invention is to provide a washing machine capable of more accurately detecting the vibration of the washing / dewatering tub at the start of spin-drying.

[0009]

Means for Solving the Problems, Embodiments of the Invention, and Effects In the washing machine according to the first aspect of the present invention which has been made to solve the above problems, a washing and dewatering tub is rotatably provided inside an outer tub. A) a motor for rotating a washing / dewatering tub, and b) all or a part of water used for washing or rinsing prior to the dewatering before washing. Eccentric load determining means for determining the magnitude of the eccentric load due to the uneven distribution of the laundry contained in the washing and dewatering tub in a state where the eccentric load is stored in the tub; andc) washing when the eccentric load is determined to be large. By controlling the motor to rotate the dehydration tub and / or the pulsator provided at the bottom of the washing and dewatering tub, the laundry is loosened in the water stored in the washing and dehydration tub. Operation control means for performing It is a symptom.

In this type of washing machine, in order to loosen a plurality of entangled laundry items, it is necessary to rotate the washing / dewatering tub or the pulsator in a state where at least water enough to soak the entire laundry is stored in the washing / dewatering tub. There is. In the washing machine according to claim 1, the magnitude of the eccentric load is checked while not discharging all the water used for washing and rinsing, but leaving at least a part of the water in the washing and dewatering tub. Is determined to be within an acceptable range. When it is determined that the eccentric load is large and loosening is necessary to eliminate the uneven distribution of the laundry, the operation control means rotates the washing dehydration tub and / or the pulsator to rotate the washing water. Promotes loosening by moving laundry inside. If necessary, water may be replenished into the washing and dewatering tub before loosening.

According to this configuration, even when the laundry is unevenly distributed in the washing and dewatering tub and the loosening operation is performed, the water used for washing and rinsing immediately before that remains in the washing and dewatering tub. It is not necessary to newly supply water, or even if water is supplied, only a small amount of water is required, and the time required for such water supply can be saved. In addition, since the eccentric load can be determined again without performing drainage after the loosening operation is performed, the time required for drainage can be saved. Therefore, the time required for dehydration can be shortened as a whole. Further, it is not necessary to supply water from the outside only for the loosening operation, or even if it is supplied, a small amount of water is sufficient, so that there is also a water saving effect that a small amount of water is used.

The washing machine according to claim 2 is the washing machine according to claim 1.
In the washing machine described in the above, the eccentric load determination means, when the washing dehydration tub is rotating at a predetermined low rotation speed,
It is characterized in that the magnitude of the eccentric load is determined in accordance with at least the fluctuation of the rotation speed during the period in which the washing and dewatering tub makes one rotation.

When the motor is controlled so that the washing / dewatering tub rotates at a predetermined constant rotation speed, if the laundry in the washing / dewatering tub is unevenly distributed around the rotation axis, uneven rotation occurs. Information corresponding to the rotation unevenness is extracted, and the magnitude of the eccentric load can be determined based on the information. Specifically, a pulse signal is obtained from a rotation sensor attached to the motor, and the signal is used to obtain a speed change amount and an index value corresponding thereto.

According to a third aspect of the present invention, in the washing machine according to the second aspect, the eccentric load determining unit determines that the eccentric load is eccentric when a speed fluctuation amount or an index value corresponding thereto exceeds a predetermined allowable value. It is characterized by determining that the load is large.

In this configuration, by appropriately setting the allowable value, it is possible to easily determine whether or not the vibration is large enough to cause a problem during dehydration.

According to a fourth aspect of the present invention, in the washing machine according to the third aspect, the eccentric load determining means includes:
The eccentric load is determined to be large when the number of times that the speed fluctuation amount or the index value corresponding thereto exceeds a predetermined allowable value reaches a predetermined number.

According to this configuration, when rotational unevenness occurs temporarily due to disturbance or the like, it is not immediately determined that the eccentric load is large, and a more accurate determination of the eccentric load can be achieved.

[0018] The washing machine according to the fifth aspect is characterized by the following:
Wherein the predetermined low-speed rotation speed is set to a rotation speed lower than the resonance frequency of the washing and dewatering tub.

According to this configuration, even when the eccentric load is abnormally large, the magnitude of the eccentric load can be determined before the washing and dewatering tub vibrates greatly.

The washing machine according to claim 6 is a washing machine according to claims 2-5.
In the washing machine according to any of the above, in order to reduce the ratio of the amount of water to the laundry, it is characterized in that the determination of the eccentric load is performed after discharging a part of the water stored in the washing dehydration tub I have.

As described above, when the eccentric load is detected in accordance with the uneven rotation of the washing and dewatering tub, if the amount of water is large, the influence of the uneven distribution of the laundry is hardly reflected on the uneven rotation. According to the configuration of claim 6, since the amount of water in the washing and dewatering tub is reduced before the operation of detecting the eccentric load, uneven rotation due to uneven distribution of the laundry appears more conspicuously. Can be detected more accurately. In addition, in the case where the reduction in the amount of water in the washing and dewatering tub causes a problem in performing the above-described loosening operation, the reduced water may be replenished before the loosening operation. If such replenishment is required, the amount is only a small part of the total water amount, so that a sufficient water saving effect and a time saving effect required for replenishment water supply can be obtained.

The washing machine according to claim 7 is the same as that of claims 2 to 5
In the washing machine according to any one of the above, the eccentric load of the eccentric load after discharging a part of the water stored in the washing dehydration tub according to the load amount so that the ratio of the water amount to the load amount is substantially the same. The determination is performed.

As described above, when the washing and dewatering tub is rotated while water is stored in the washing and dewatering tub, and the rotation unevenness is detected, the rotation unevenness depends on the load amount and the amount of water. That is, when the amount of water is relatively large with respect to the load, the rotation unevenness is reduced. In the washing machine according to the seventh aspect, before executing the determination of the eccentric load as described above, a part of the water stored in the washing and dewatering tub is discharged to the outside according to the load amount, so that the load is reduced. Make the ratio of the amount of water to the amount equal. Accordingly, the speed variation with respect to the same eccentric load is almost the same regardless of the load amount, and therefore, the allowable value for determining the eccentric load can be made the same regardless of the load amount. In addition, since the speed fluctuation becomes relatively large, the accuracy of the determination is improved.

The washing machine according to the eighth aspect of the present invention is the washing machine according to any one of the third to seventh aspects, wherein the eccentric load is set based on the load amount and the amount of water stored in the washing dewatering tub. It is characterized in that the allowable value for determination is changed.

[0025] The washing machine according to the ninth aspect provides the washing machine according to the first to eighth aspects.
In the washing machine according to any one of the above, when it is determined that the eccentric load is small, the operation control means performs drainage while continuing rotation of the washing and dewatering tub, and starts the dehydration operation after drainage is completed. It is characterized by.

In this configuration, if it is determined that the eccentric load is small in a state where water is stored in the washing and dewatering tub, the stored water is discharged, and then the washing and dewatering tub is rotated at a high speed. Thereby, dehydration is achieved.

The washing machine according to the tenth aspect is characterized in that the washing machine according to the first aspect
9. The washing machine according to any one of items 9, wherein the central axis of the washing and dewatering tub is provided to be inclined at a predetermined angle with respect to the vertical line.

According to this configuration, when the washing and dewatering tub is rotated at a low speed, a force for accelerating when the eccentric load proceeds downwardly on the slope acts and a force for decelerating when the eccentric load proceeds upwardly on the slope. Works. For this reason, since rotation unevenness appears remarkably, the eccentric load can be accurately determined.

The washing machine according to claim 11, wherein: a) a washing and dewatering tub having a bottomed cylindrical shape with an open upper end surface, the center axis of which is inclined at a predetermined angle with respect to a vertical line. B) a motor that rotationally drives the washing and dewatering tub, and c) determining means for detecting a change in the rotation speed of the motor and determining a degree of uneven distribution of the laundry in the washing and dewatering tub based on the change. , Are provided.

According to this configuration, since the washing and dewatering tub is provided at an angle, uneven rotation is remarkably exhibited when the laundry is unevenly distributed as described above. By using this rotation unevenness, the eccentric load can be accurately determined,
Undesirably large noise can be prevented from being generated. In addition, since the outer tub can be prevented from contacting the housing, it is not necessary to use a cushioning material for the housing, and the cost of the washing machine can be reduced.

The washing machine according to the twelfth aspect provides the washing machine according to the eleventh aspect.
In the washing machine described in the above, the determination unit, a position detection unit that outputs a pulse signal according to the rotation position of the motor, and a calculation unit that calculates an index value corresponding to the speed change amount based on the pulse signal And an eccentric load determining means for determining that the eccentric load is large when the index value exceeds a predetermined allowable value.

Usually, the position detecting means is attached to the motor, for example, for controlling the rotation speed of the motor. According to this configuration, the magnitude of the eccentric load can be reliably determined at low cost. .

The washing machine according to the thirteenth aspect provides the washing machine according to the twelfth aspect.
Is characterized in that the number of times that the index value exceeds an allowable value is counted, and when the count reaches a predetermined value, it is determined that the eccentric load is large.

According to this configuration, when rotational unevenness occurs temporarily due to disturbance or the like, it is not immediately determined that the eccentric load is large, and a more accurate determination of the eccentric load can be achieved.

Further, a washing machine according to a fourteenth aspect of the present invention is the washing machine according to the twelfth aspect, wherein the duty ratio of the pulse signal or the period ratio of two consecutive pulses is used as the index value. .

That is, when the rotation speed of the washing and dewatering tub changes due to the eccentric load, the duty ratio and the period ratio of the pulse signal also change. Therefore, it is possible to determine the magnitude of the eccentric load by using these. .

[0037]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment (hereinafter referred to as "embodiment 1") of a washing machine according to the present invention will be described below with reference to the drawings. FIG. 1 is a side sectional view showing the configuration of the washing machine of the present embodiment. Inside the casing 1 of the washing machine, a cylindrical outer tub 2 having a bottom is provided with a front hanging rod 3 and a rear hanging rod 4 (one each of which is visible in the figure, but actually two each are present). ) So as to be inclined forward. Corresponding to the projection of the outer tub 2 forward and forward, the upper part of the front surface of the housing 1 also projects. Inside the outer tub 2, a washing and dewatering tub 5 having a large number of dehydration holes in a peripheral wall is rotatably supported about a main shaft 6. A pulsator 7 for stirring the laundry is arranged at the bottom of the washing and dewatering tub 5.
The rotational power of a motor 8 attached to the lower surface of the motor is transmitted to the washing and dewatering tub 5 and the pulsator 7 via a transmission mechanism 9 including a motor pulley, a V-belt, a main pulley, and the like, and a power switching mechanism 10. The power switching mechanism 10 includes a clutch and rotates only the pulsator 7 in one direction or both directions during a washing operation or a rinsing operation, and integrally rotates the washing / dewatering tub 5 and the pulsator 7 in one direction (a normal rotation direction) during a spin-drying operation. Switch) so as to rotate.

[0038] Behind the upper part of the outer tub 2 is a water inlet 1 provided with a detergent container 11a for charging a detergent or the like housed therein.
1 is provided. A water supply pipe 12 provided with a water supply valve 13 on the way is connected to the water supply port 11. When the water supply valve 13 is opened, water flows into the water supply port 11 from an external water tap through the water supply pipe 12. , Lower outer tank 2
Water is discharged from the water inlet 11 toward the inside. One end of a drain pipe 14 is connected to the front end of the bottom of the outer tub 2, that is, the lowest part, and the drain pipe 14 is opened and closed by a drain valve 15. Although not shown, the other end of the drain pipe 14 is connected to an external drain ditch via an upright drain hose. The opening and closing operation of the drain valve 15 is related to the switching operation of the power switching mechanism 10 described above. When the attached torque motor (omitted in FIG. 1) is not operating, the drain valve 15 is closed and the pulsator is closed. Numeral 7 is separated from the washing and dewatering tub 5 and can be rotated independently. When the torque motor is operated and the wire is pulled halfway, the pulsator 7 and the washing and dewatering tub 5 are connected with the drain valve 15 closed. When the wire is further pulled, the drain valve 15 is opened while the pulsator 7 and the washing / dewatering tub 5 are connected.

As described above, in the washing machine of this embodiment, the outer tub 2 and the washing / dewatering tub 5 are inclined forward to
The upper surface opening faces forward rather than vertically upward. That is, the center axis CL of the outer tub 2 is disposed so as to be inclined by a predetermined inclination angle α with respect to the vertical line VL. Therefore, a user standing in front of the washing machine can
It is easy to visually recognize the bottom of the garment and to take out the laundry easily. Here, if the inclination angle α is in the range of about 5 to 20 degrees, the laundry can be easily taken out sufficiently, and the protrusion of the housing 1 does not need to be too large. In this embodiment, the inclination angle α is set to about 10 degrees.

FIG. 2 is an electrical configuration diagram of a main part of the washing machine of this embodiment. CPU, RAM, RO at the center of control
A control unit 20 including M, a timer, and the like is provided. An operation signal is input to the control unit 20 from an operation unit 21 including a plurality of operation keys, and a water level detection signal is input from a water level sensor 22 for detecting the level of water stored in the outer tub 2. Is done. The control unit 20 controls the rotation of the motor 8 via the inverter drive unit 23 and controls the operations of the torque motor 26 and the water supply valve 13 via the load drive unit 25. The torque motor 26 controls the operation of the clutch 27 and the drain valve 15 as described above. The motor 8 is provided with a rotation sensor 24 that outputs a pulse signal according to the rotation, and the pulse signal is input to the control unit 20. The rotation sensor 24 includes, for example, a magnet provided on the rotor of the motor 8 and a Hall element provided at a predetermined position of the stator. In this embodiment, the rotation sensor 24 includes a Hall element provided at a predetermined angle from each other. Three types of pulse signals having different phases are obtained. This configuration will be described later in detail.

FIG. 3 is a flowchart showing a flow of a standard washing process in the washing machine of the present embodiment. The operation of the washing machine will be schematically described with reference to FIG. When the start of the washing is instructed, before the water is supplied, the washing and dewatering tub 5 is started.
Is detected, that is, the load amount of the laundry put into the hopper (step S1). Specifically, the pulsator 7 is rotated for a short time, and the load amount is determined according to the time during which the inertial rotation continues. Of course, the load amount detection is not limited to this method, and any method may be used. In the present embodiment, the load amount is classified into four types, that is, a large amount, a medium amount, a small amount, and a very small amount, based on such load amount detection, and the washing water level at the time of subsequent washing or pool rinsing is increased according to each load amount. Water level, medium water level,
Set low and extremely low water levels.

When the substantial washing is started, water is supplied to the washing water level determined as described above in the washing and dewatering tub 5, and the pulsator 7 is rotated in one direction or both directions at a predetermined speed. Washing is performed (step S
2). When the washing is completed, the water in the washing and dewatering tub 5 is drained, and the washing and dewatering tub 5 and the pulsator 7 are rotated at a high speed to perform intermediate dehydration (step S).
3). By this intermediate dewatering, detergent water soaked into the laundry is scattered and removed.

Next, dehydration rinsing is performed as the first rinsing (step S4). In the dehydration rinsing, water is poured onto the laundry in the form of a shower from the water inlet 11 while rotating the laundry dehydration tub 5 so that the laundry absorbs clean water, and instead, detergent water permeating the laundry is removed. They are trying to extrude. Then, after sufficient water is contained in the laundry, intermediate dehydration is performed by the process of step S5 similar to step S3, and the water soaked into the laundry is scattered. Further, step S is used as the second rinsing.
4, the dehydration rinsing and the intermediate dehydration are performed by the processing of steps S6 and S7 similar to S5, and a predetermined amount of water is supplied into the washing and dewatering tub 5, and the pulsator 7 is rotated as in step S2. Rinsing is performed (step S8). When the pool rinsing is completed, the water in the washing and dewatering tub 5 is drained, and the final dehydration is performed by rotating the washing and dewatering tub 5 and the pulsator 7 at a high speed as in the case of the intermediate dehydration (step S9).

The above procedure is a standard procedure,
Depending on the type of laundry, the procedure is appropriately changed, for example, such as performing pool rinsing instead of dehydration rinsing, or performing water rinsing instead of pool rinsing.

In the washing machine of the first embodiment, the washing is carried out after the end of the process of stirring the laundry in a state where a predetermined amount of water is stored in the washing / dewatering tub 5, such as washing, rinsing with a reservoir (or rinsing with water). It has a feature in the control in the dehydration process (steps S3 and S9).

FIGS. 4 and 5 are control flowcharts during such a spin-drying process, FIG. 6 is a waveform diagram for explaining the operation of eccentric load determination during the spin-drying process, and FIGS. 7 and 8 are washing diagrams during the spin-drying process. It is a figure showing an example of change of rotation speed of a dehydration tank. Hereinafter, a control operation at the time of starting dehydration in the washing machine of the present embodiment will be described with reference to FIGS.

When the washing and the rinsing are completed, the water used for the washing and the rinsing is stored in the washing and dewatering tub 5. The laundry is stacked on the bottom of the washing and dewatering tub 5 in the water. When the dehydration process is started, the control unit 20
Executes a process for draining a part of the stored water in accordance with the load amount, using the load amount data already determined as described above. That is, first, the torque motor 26 is operated to open the drain valve 15 to start draining (step S10). Next, it is determined whether or not the load is a heavy load (step S11). If the load is a heavy load, the amount of water at the high water level is reduced to reach the high and middle water level that is set substantially between the high and middle water levels. When it reaches (“Y” in step S12), the process proceeds to step S18, and the drain valve 1
5 is closed to stop draining. When the load is a medium load (“Y” in step S13), the amount of water at the middle water level decreases and reaches a low water level (“Y” in step S14). ("Y" in step S15) When the water level at the low water level decreases and reaches the extremely low water level ("Y" in step S16), if it is not any of the heavy load, the medium load, or the small load, that is, When the load is extremely small, when the water amount at the extremely low water level decreases and reaches the ultra-low water level set at a position lower than the extremely low water level (“Y” in step S17), The drain valve 15 is closed to stop draining (step S1).
8). Thus, in the above-described processing, as the load is relatively small, the ratio of the drainage amount to the water amount stored as the washing water level is increased. The reason for performing such drainage control will be described later.

Next, the laundry laminated on the bottom of the washing and dewatering tub 5 is unevenly distributed around the rotation axis.
A process for determining the magnitude of the eccentric load is executed. That is, the control unit 20 resets the determination number counter value N1 and the abnormality number counter value N2 (step S19).
In addition, the torque motor 26 is operated to pull the wire halfway, and the clutch 27
Thereby, the washing and dewatering tub 5 and the pulsator 7 are connected so as to rotate integrally (step S20). In this state, the control unit 20 starts the motor 8 via the inverter driving unit 23 and increases the rotation speed of the motor 8 to 30 rpm (Step S21). At this time, the ratio (reduction ratio) between the rotation speed of the motor 8 and the rotation speed of the washing and dewatering tub 5 is about 1.5. Therefore, the rotation speed of the washing and dewatering tub 5 is about 20 r.
pm.

When the washing and dewatering tub 5 is rotated at a high speed at the start of dehydration after washing, the detergent water stored in the washing and dewatering tub 5 is vigorously stirred to generate an abnormally large amount of foam. There is a high possibility that bubbles will spout upward from a narrow gap with the washing and dewatering tub 5. According to the experiments performed by the inventors of the present application, if the rotation speed of the washing and dewatering tub 5 is about 30 rpm or less, such an abnormal occurrence of bubbles can be avoided. Therefore, it is preferable that the rotation speed be kept within the range. . In addition, it is not necessary to consider the problem of foaming at the start of dehydration after the end of the pool rinsing (since there is almost no detergent contained in the water), but the horizontal resonance frequency of the washing and dehydrating tub 5 is 65 to 100 rpm.
Therefore, it is preferable to set the rotation speed at least lower than the resonance frequency.

Immediately after turning on the motor 8 as described above, the control unit 20 starts counting time using a timer (step S2).
2). The rotation speed of the washing and dewatering tub 5 rises, for example, as shown by a solid line L1 or a dotted line L2 in FIGS.
When the speed reaches m, the speed is controlled to be substantially constant. Although the speed increase depends on the load amount, even when the load amount is large, the rotation speed of the washing and dewatering tub 5 has reached 20 rpm at the time when t1 has elapsed from the time when the motor 8 was turned on. When the timer counts the time t1 (“Y” in step S23), the control unit 20 starts calculating the speed change amount ΔV based on the pulse signal obtained from the rotation sensor 24 (step S24).

Regarding the method of calculating the speed change amount ΔV,
This will be described in detail with reference to FIG. As described above, the rotation sensor 24 includes three Hall elements whose mounting positions are different from each other with respect to the rotor of the motor 8, and each Hall element has a phase with each other during one rotation of the motor 8. A two-period square wave pulse signal that is different (having a phase shift of about 60 °) is output (see FIG. 6A). Assuming that the time of one cycle of the pulse signal is T, the reciprocal (1 / T) of T is the speed V.

If the laundry is unevenly distributed inside the washing and dewatering tub 5 arranged inclining as in the present embodiment, the eccentric load is accelerated as the rotation progresses downward with the rotation, and the eccentric load is increased. Is decelerated when traveling upward. Therefore, FIG.
As shown in (c), a speed fluctuation synchronized with the rotation of the washing and dewatering tub 5, that is, rotation unevenness occurs. Such acceleration and deceleration caused by the eccentric load become remarkable due to the configuration in which the washing and dewatering tub 5 is inclined. Since the friction between the rotating shaft and the bearing fluctuates when the washing and dewatering tub 5 swings in the horizontal direction, the rotation unevenness also occurs in synchronization with the rotation.

The speed V is determined by the rising edge timings of the three pulse signals (for example, P1 to P1 in FIG. 6B).
P10), the difference between the speed Vn obtained at a certain time point Pn and the speed Vn + 1 obtained at the next time point Pn + 1 is calculated, and this is used as the speed change amount ΔV. . That is, ΔV = Vn + 1−Vn.

When the speed V fluctuates as shown in FIG. 6C, the speed change amount ΔV fluctuates as shown in FIG. 6D. The greater the eccentric load, the greater the rotational unevenness, and therefore the greater the fluctuation amplitude of the speed change amount ΔV. Therefore, the difference between the maximum speed change amount ΔVmax and the minimum speed change amount ΔVmin during one rotation of the washing and dewatering tub 5 is used as the speed change amount maximum amplitude ΔA, which is used for determining the eccentric load. That is, ΔA = ΔVmax−ΔVmin.

Returning to the flowchart, the description will be continued. The control unit 20 continuously calculates the speed change amount ΔV ten times as described above (step S25). For example, in the example of FIG. 6, the speed change amount ΔV is calculated at timings P1 to P10. The time required for the washing and dewatering tub 5 to make one rotation is about 1.5 times the time required for the motor 8 to make one rotation (because the reduction ratio is about 1.5). When the number of times is calculated, the washing and dewatering tub 5 has turned at least once at that time. The control unit 20 determines whether or not the determination counter value N1 is 4 (Step S).
26) If it is less than 4, ΔVmax and ΔVmin among the 10 speed change amounts ΔV obtained by the above 10 calculations
Is calculated, and the speed change maximum amplitude ΔA is calculated (step S27). Then, it is determined whether or not the speed change maximum amplitude ΔA is larger than a predetermined threshold (step S28). This threshold is determined experimentally in advance.

As described above, the rotation speed of the washing and dewatering tub 5 varies depending on the eccentric load caused by the uneven distribution of the laundry.
Water is stored inside the washing and dewatering tub 5, and the occurrence of uneven rotation is affected by the water. That is, if the amount of water is large, the influence of the eccentric load is reduced by the weight of the water, so that even if the magnitude of the eccentric load due to the uneven distribution of the laundry is the same, the ratio of the amount of water to the load is The larger the value, the smaller the rotation unevenness. In this washing machine, the washing water level, that is, the washing water amount at the time of washing or pool rinsing is changed according to the load amount, as described above, but in terms of the ratio of the water amount to the load amount, the smaller the load amount, the more the water amount. The percentage increases. For this reason, if it is attempted to determine the eccentric load as described above while holding all the water supplied during washing and rinsing, the smaller the load amount, the smaller the speed change and the more difficult the accurate determination. In addition, even with a large load, when the high water level is maintained, the rotational unevenness is not so remarkable, and the eccentric load determination may lack accuracy.

Therefore, in the present washing machine, as described above, when the load is large, a relatively small amount of water among the water stored in the washing and dewatering tub 5 is drained. However, the relative proportion of the amount of wastewater is set to be large. This reduces the amount of water as a whole,
The ratio of the amount of water to the amount of load is made substantially constant irrespective of the amount of load. As a result, even when the load amount is relatively small, the eccentric load is easily reflected on the rotation unevenness, and the maximum amplitude ΔA of the speed change amount can be determined using the same threshold value.

The controller 20 determines that the eccentric load is abnormally large when the speed change maximum amplitude ΔA is larger than the threshold value determined in this way, and the abnormal number counter value N
2 is incremented (step S29), and the value is 2
Is determined (step S30). If N2 is smaller than 2, the determination counter value N1 is incremented (step S31), and the process returns to step S24. If it is determined in step S28 that the speed change maximum amplitude ΔA is equal to or smaller than the threshold value, the determination number counter value N1 is incremented without incrementing the abnormality number counter value N2, and the process returns to step S24.

Now, it is assumed that the laundry is actually unevenly distributed and the eccentric load is abnormally large. In this case, when the determination number counter value N1 is "0", the above-described step S is performed.
After the abnormal number counter value N2 has become "1" through the processing of steps S24 to S29, the determination number counter value N1 becomes "1" in step S31, and the process returns to step S24. Then, when the processes of steps S24 to S29 are performed next, the abnormal frequency counter value N2 becomes "2", and the process proceeds to step S3.
If it is 0, it is determined that N2 is 2, and the process proceeds to step S32. Steps S32 to S36 are processing of a loosening process for eliminating uneven distribution of the laundry.

When it is determined in step S28 that the maximum speed change amount amplitude ΔA exceeds the threshold value, the process does not immediately proceed to the loosening process. The loosening process is performed when there are two determinations that the value has been exceeded. Therefore, for example, when the speed variation maximum amplitude ΔA exceeds a threshold value due to a very short-time disturbance or electric noise, the speed is undesirably undesired when the speed does not actually fluctuate due to the eccentric load. Execution of the loosening operation can be avoided.

In the unraveling process, the control unit 20 once turns off the motor 8 to stop the washing / dewatering tub 5 (Step S).
32). Next, the water supply valve 13 is opened (step S3).
3) The water level detected by the water level sensor 22 is equal to the value in step S.
Water supply is continued until the water level returns to the original water level before the wastewater treatment of 10 to S18 (step S34). When returning to the original water level, the water supply valve 13 is closed (step S35). Here, the reason why the water level is recovered by supplying water is that if the amount of water is too small during the subsequent loosening operation, the laundry does not move sufficiently in the water, and it is difficult to obtain a desired loosening effect. In this washing machine, a small amount of water is discharged before the determination of the eccentric load, and the reduced water is replenished after the determination of the eccentric load. Since the total amount of water stored in the washing and dewatering tub 5 is small, the water used for washing and rinsing can be effectively reused.
Also, the time required for water supply is short.

After water is supplied as described above, first, the washing and dewatering tub 5 and the pulsator 7 are integrally moved in the forward direction for approximately one hour.
The pulsator 7 is rotated about one rotation, and then the pulsator 7 is rotated about one rotation in the reverse direction by releasing the interlock between the washing and dewatering tub 5 and the pulsator 7. At this time, since the washing and dewatering tub 5 is rotating in the normal rotation direction due to inertia, the washing and dewatering tub 5 and the pulsator 7 are rotated in opposite directions to each other, and the water flow is greatly disturbed to generate a vertical water flow. As a result, the laundry that has been entangled and formed into a large lump can be turned upside down in the water to facilitate loosening. Thereafter, the pulsator 7 is rotated for a predetermined period of time (about 2 minutes) while reversing the pulsator 7 in both the forward and reverse directions for a short time. As a result, the entangled laundry is loosened and dispersed on average around the rotation axis. After performing the loosening operation, the process returns to step S19, and the eccentric load determination operation is performed again.

In step S28, the speed change maximum amplitude Δ
Even if it is determined that A is equal to or less than the threshold value, step S
Until it is determined at 26 that the number-of-times counter value N1 has reached 4, the processes of steps S24 to S31 are repeated. Therefore, if the speed change maximum amplitude ΔA exceeds the threshold twice during such a determination is repeated four times, the process proceeds to the above-described loosening process.

If no abnormality is detected and the above-described determination is repeated four times, in step S26 the determination counter value N
It is determined that 1 is 4. Then, the control unit 20 operates the torque motor 26 to open the drain valve 15 and start draining (step S37). At this time, the washing and dewatering tub 5 is continuously rotated at about 20 rpm. By draining the laundry while rotating the washing / dewatering tub 5, it is possible to prevent the laundry from moving toward the connection of the drain pipe 14 due to the flow of the drained water.

The control unit 20 detects the water level in the washing and dewatering tub 5 by the water level sensor 22, and if the water level falls to the reset water level set at a position near the bottom of the washing and dewatering tub 5 ("S" in step S38). Y "), the motor 8 is turned off, and the rotation of the washing and dewatering tub 5 is stopped (step S39). By stopping the rotation of the washing and dewatering tub 5, the water remaining at the bottom of the outer tub 2 is smoothly discharged. When the timer counts t2 ("Y" in step S40), the control unit 20 turns on the motor 8 again to increase the rotation speed of the washing and dewatering tub 5 (step S41), and executes dehydration (step S41). Step S42). As shown in FIG. 7, the rotation speed of the washing dehydration tub 5 is a predetermined dehydration rotation speed (1000
(about rpm) and is maintained substantially constant. Then, if the predetermined dehydration time has elapsed (step S4
The control unit 20 turns off the motor 8 and ends the spin-drying process (step S44).

In the case of the conventional washing machine, in order to perform the loosening operation as described above, it is necessary to supply water up to a predetermined water level, execute the loosening operation, and further drain all the water. However, in the washing machine of the first embodiment,
Since the eccentric load is determined in a state where most of the water used for washing and rinsing is stored in the washing and dewatering tub 5, even when performing the loosening operation, it is not necessary to perform a large amount of water supply and drainage. The time required for loosening operation is shorter by that much.

In the above embodiment, as described above, in order to set the threshold value for determining the speed change maximum amplitude ΔA to the same value irrespective of the load amount, the remaining water amount is firstly drained. Is adjusted. Of course, instead of draining first, the threshold value for determining the speed change maximum amplitude ΔA may be changed according to the load amount. That is,
In this case, if the load amount is small, the ratio of the water amount to the load amount becomes relatively large, and it becomes difficult for the eccentric load to be reflected on the rotation unevenness due to the influence of the water. The eccentric load may be determined to be abnormal.

Next, a description will be given of a washing machine according to a second embodiment (hereinafter, referred to as “embodiment 2”) according to the present invention. The configuration of this washing machine is the same as that of the washing machine according to the first embodiment, and the description is omitted. In the washing machine according to the second embodiment, unlike the washing machine according to the first embodiment, after the washing and the pool rinsing are completed, all the water remaining in the washing and dewatering tub 5 is once discharged to start the dehydrating operation, and the operation is started. The eccentric load is determined on the basis of the rotational unevenness of the motor 8 at the beginning of the process.

FIG. 12 is a diagram showing a change in the basic rotation speed during the spin-drying process in the washing machine of the second embodiment. As described above, in this type of washing machine, the washing and dewatering tub 5 has a horizontal resonance frequency and a vertical resonance frequency, and the horizontal resonance frequency is determined by the rotation speed of the washing and dewatering tub 5. 65-1
About 00 rpm, vertical resonance frequency is 130-200
rpm. Of course, this value also depends on the size, weight, load, and the like of the washing and dewatering tub 5. Since the vibration of the outer tub 2 increases in the vicinity of such a resonance frequency, when increasing the rotation speed, it is preferable to pass the vicinity of the resonance frequency as quickly as possible. Therefore,
In this washing machine, after starting the motor 8 to start the rotation of the washing and dewatering tub 5, the motor 8 is accelerated so as to quickly pass the rotation speed corresponding to the resonance frequency in the lateral direction. Then, control is performed so that the rotation speed of the washing and dewatering tub 5 is maintained substantially constant at a rotation speed of about 120 rpm, which is between the horizontal resonance point and the vertical resonance frequency, and the eccentric load is determined in that state. . At this time, if it is determined that the eccentric load is small, then the motor 8 is accelerated so as to quickly pass the rotation speed corresponding to the resonance frequency in the vertical direction, and after passing the rotation speed, the motor 8 is washed and removed at approximately 240 rpm. The rotation speed of the water tank 5 is controlled to be kept substantially constant. In this state, the eccentric load is determined again, and if it is determined that the eccentric load is small, the rotation speed is further increased.

FIGS. 9 to 11 are flow charts showing the procedure at the time of the dehydration process for realizing the above-described rotation control. Hereinafter, the control operation of the dehydration process of the washing machine according to the second embodiment will be described with reference to FIGS.

When the washing and the pool rinsing are completed, the control unit 20
Operates the torque motor 26 to open the drain valve 15 (step S50). Thereby, the water stored in the outer tub 2 is discharged to the outside. When a predetermined drain time has elapsed, the control unit 20 starts the motor 8 via the inverter driving unit 23, and the rotation speed of the motor 8 is set to 180 rpm.
Control is performed so as to increase the rotation speed of the washing / dewatering tub 5 to about 120 rpm (step S51).

Immediately after turning on the motor 8 as described above,
The control unit 20 starts counting time using a timer (step S5).
2) The calculation of the speed change amount ΔV is started based on the pulse signal obtained from the rotation sensor 24 (step S5).
3). The method of calculating the speed change amount ΔV is the same as that described in the first embodiment. After that, the judgment number counter value N1 and the abnormality number counter value N2 are reset (Step S).
54) It is determined whether or not the counting of the timer has exceeded t1 (step S55). Until t1 has elapsed, it is determined whether or not the rotation speed V 'of the washing and dewatering tub 5 has reached a predetermined rotation speed Va (120 rpm in this example) (step S).
56) The acceleration control is performed until the rotation speed V 'reaches Va (step S57). Thereby, the rotation speed increases as shown in FIG.

As described above, in order to obtain the speed change amount ΔV during the period in which the washing and dewatering tub 5 makes at least one rotation, the speed change amount ΔV is calculated ten times consecutively (step S6).
4). Thereafter, it is determined whether or not the number-of-determinations counter value N1 is 10 (step S65). If it is less than 10, the minimum of the 10 speed change amounts ΔV obtained by the above 10 calculations is determined. It is determined whether or not the speed change amount ΔVmin is larger than a predetermined threshold value (step S6).
6). This threshold is determined experimentally in advance.

If the minimum speed change amount ΔVmin is larger than the threshold value, it is determined that the eccentric load is abnormally large, and the abnormal number counter value N2 is incremented (step S6).
7) It is determined whether the value has reached 3 (step S68). If the value of N2 is smaller than 3, the determination counter value N1 is incremented (step S6).
9) Return to step S55. If it is determined in step S66 that the minimum speed change amount ΔVmin is equal to or smaller than the threshold value, the determination counter value N1 is incremented without incrementing the abnormality counter value N2 (step S69), and the process returns to step S55.

Now, it is assumed that the laundry is actually unevenly distributed and the eccentric load is abnormally large. In this case, when the determination number counter value N1 is "0", the above-described step S is performed.
After the number-of-abnormalities counter value N2 becomes "1" by the processing of 55 to S57 and S64 to S67, N1 becomes "1" in step S69, and the process returns to step S55. Then, the abnormal number counter value N2 becomes "2" by the processing of steps S55 to S57 and S64 to S67. This is repeated, and if it is determined in step S68 that the abnormal number counter value N2 is 3, the process proceeds to step S70, where a loosening process for eliminating uneven distribution of the laundry is executed. In the loosening process, the motor 8 is stopped (step S
70), the drain valve 15 is closed (step S7)
1). Then, the water supply valve 13 is opened (step S
72), after water is supplied until the water level in the washing and dewatering tub 5 reaches the predetermined water level ("Y" in step S73), the above-described rotation control of the washing and dewatering tub 5 and the pulsator 7 is performed in the unraveling operation. (Step S74). Thereafter, the torque motor 26 is operated to open the drain valve 15 (step S75). If a predetermined drain time has elapsed (“Y” in step S76), the process returns to step S51 and starts the dehydration operation again. I do.

In step S66, the minimum speed change amount ΔVmi
Even if it is determined that n is equal to or less than the threshold value, even if the
Steps S55 to S57, S64 to S64 until it is determined in S64 that the determination counter value N1 has reached 10.
The process of S69 is repeated. Therefore, if the abnormality is detected three times while the determination is repeated ten times, the process proceeds to the above-described loosening process.

If no abnormality is detected and the above-described determination is repeated 10 times, the number-of-times-of-determination counter value N1 is determined in step S65.
Is determined to be 10, and the process returns to step S54. When the rotation speed V 'reaches Va, the process proceeds from step S56 to S60, and constant speed control is performed so as to maintain the rotation speed V' near Va. During the period of the constant speed control, the speed change amount ΔV is calculated ten times (step S77). Then, it is determined whether or not the number-of-determinations counter value N1 is 10 (step S78).
The maximum speed change amount ΔVmax and the minimum speed change amount ΔVmin are found among the ten speed change amounts ΔV obtained by the ten calculations, and the speed change maximum amplitude ΔA is calculated (step S79). The processes of steps S79 to S83 are the same as steps S28 to S31 of the first embodiment except that the threshold for determining N2 is different.

When it is determined that there is an abnormal eccentric load based on the maximum speed change amplitude ΔA while the rotation speed V ′ is maintained near Va, the loosening stroke is executed. When the timer counts t1 (step S55)
Then, the control unit 20 determines whether or not the time has elapsed t2 (step S58). Until the time reaches t2, it is determined whether or not the rotation speed V 'of the washing and dewatering tub 5 is Vb (step S59), and a predetermined acceleration control is executed until the rotation speed V' reaches Vb (step S57). At that time, the eccentric load is determined in the same manner as at the time of acceleration up to the rotation speed Va. After the rotation speed V 'has reached Vb ("Y" in step S59), constant speed control is performed (step S60), and the eccentric load is determined in the same manner as in the case of the constant speed.

The threshold for determining the minimum speed change amount ΔVmin in step S66 is changed between when accelerating to Va and when accelerating to Vb. This is because, even with the same eccentric load, the speed change state differs depending on the rotation speed. The threshold value for determining the maximum amplitude ΔA of the speed change amount in step S80 is also changed between the constant speed near Va and the constant speed near Vb for the same reason.

When the timer reaches t2 without determining that there is an abnormal eccentric load ("Y" in step S58), the rotation speed of the washing / dewatering tub 5 is reduced to the dehydration rotation speed Vc. The motor 8 is controlled so as to rise up to the maximum, and dehydration is executed (step S61). Then, when the time counted by the timer reaches a predetermined dehydration time t3 ("Y" in step S62), the motor 8 is turned off (step S6).
3) End the dewatering process.

Next, a description will be given of a washing machine according to a third embodiment of the present invention (hereinafter, referred to as “third embodiment”). The basic configuration of the washing machine is the same as that of the washing machines according to the first and second embodiments, and therefore the description thereof is omitted. The washing machine according to the third embodiment differs from the above two embodiments in the method of detecting uneven rotation.

Therefore, this detection method is first described with reference to FIGS.
This will be described with reference to FIG. As shown in FIG. 13, the pulse signal obtained from the Hall element of the rotation sensor 24
Is rotating at a constant speed, its duty ratio (W1
/ T1) is approximately 0.5. However, when the motor 8 has uneven rotation, the duty ratio fluctuates. When the duty ratio of any one of the pulse signals is continuously measured, the duty ratio also fluctuates about 0.5 in synchronization with the rotation of the washing and dewatering tub 5, as shown in FIG. The fluctuation width ΔD corresponds to the magnitude of the rotation unevenness, that is, the magnitude of the eccentric load. Therefore, when the duty ratio exceeds a certain threshold value, it can be estimated that the eccentric load is abnormally large.

In place of the duty ratio, the period ratio of two consecutive pulse signals, that is, T1 / (T1 + T
2) may be used. If the period ratio is used, it is possible to apply even a configuration in which the duty ratio of the pulse signal does not become 0.5 at a constant rotation speed.

In the washing machine according to the third embodiment, when starting the spin-drying operation, the rotation speed of the spin-drying tub 5 is controlled as shown in FIG. FIG. 15 and FIG. 16 are flowcharts showing a procedure at the time of the spin-drying process of the washing machine of the third embodiment. Hereinafter, with reference to FIG. 15 and FIG. 16, a control operation of the dehydration process of the washing machine of the third embodiment will be described.

When the washing and the pool rinsing are completed, the control unit 20
Operates the torque motor 26 to open the drain valve 15 (step S100). Thereby, the water stored in the outer tub 2 is discharged to the outside. When the predetermined drainage time has elapsed, the control unit 20 starts the motor 8 via the inverter driving unit 23, and the rotation speed of the motor 8 becomes 180 rpm
m (about 120 rpm at the rotation speed of the washing and dewatering tub 5) (step S101).

Immediately after turning on the motor 8 as described above,
The control unit 20 starts counting time using a timer (step S1).
02), reset the abnormal frequency counter value N2 (step S103), and determine whether or not the timer has counted t1 (step S104). Until t1 has elapsed, it is determined whether or not the rotation speed V 'of the washing and dewatering tub 5 has reached a predetermined rotation speed Va (120 rpm in this example) (step S105), and the rotation speed V' reaches Va. Until, acceleration control is performed (step S106), and step S1
Return to 04.

When the rotation speed V 'reaches Va, step S is performed.
From 105 to S109, constant speed control is performed so as to maintain the rotation speed V 'near Va. During the period of the constant speed control, the duty ratio D of the pulse signal from the rotation sensor 24 is calculated as described above (step S11).
3) It is determined whether or not the duty ratio D exceeds a threshold (step S114). If it exceeds the threshold value, the abnormal number counter value N2 is incremented (step S115), and it is determined whether or not the N2 has reached a predetermined value P (step S116). If N2 has not reached P, the process returns to step S104. If the duty ratio D is equal to or smaller than the threshold in step S114, the process returns to step S104 without incrementing N2. Therefore, the duty ratio D of the pulse signal is compared with the threshold value only during the period when the washing and dewatering tub 5 is maintained at a constant speed,
The number of times exceeding the threshold is added up.

If the laundry is actually unevenly distributed and the eccentric load is abnormally large, the abnormal number counter value N2
Reaches a predetermined value P, steps S116 to S117
Then, a loosening process for eliminating uneven distribution of the laundry is performed. In the loosening process, the above-described steps S70 to S7
Steps S117 to S123 similar to step 6 are executed.

When the timer counts t1 ("Y" in step S104), the control unit 20 next determines that the count has reached t1.
It is determined whether or not 2 has elapsed (step S107).
Until the time reaches t2, it is determined whether or not the rotation speed V 'of the washing and dewatering tub 5 is Vb (step S108).
Predetermined acceleration control is performed until Vb is reached (step S106). After the rotation speed V 'has reached Vb ("Y" in step S108), constant speed control is performed (step S109), and the duty ratio D of the pulse signal is compared with the threshold value as in the case of the constant speed. You. If the abnormal number counter value N2 integrated during the two constant speed controls does not reach the predetermined value P, it is determined that there is no abnormally large eccentric load, and when the timer count reaches t2 (step S107). "Y"), the rotation speed of the washing and dewatering tub 5 is equal to the dehydration rotation speed Vc.
The motor 8 is controlled so as to rise up to the maximum, and dehydration is executed (step S110). Then, when the time measured by the timer reaches a predetermined dehydration time t3 (step S111).
"Y"), the motor 8 is turned off (step S112), and the dewatering process ends.

As described above, in the washing machines of the second and third embodiments, the magnitude of the eccentric load is determined based on the uneven rotation of the washing and dewatering tub at the start of the spin-drying operation. The loosening operation is performed, and when the eccentric load is small, the high-speed dehydrating operation is performed. Therefore, it is possible to prevent the outer tub 2 from swinging largely and coming into contact with the housing 1 in advance during the high-speed dehydrating operation.

The above embodiment is merely an example, and it is apparent that changes and modifications can be made within the spirit of the present invention.

[Brief description of the drawings]

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

FIG. 2 is an electric configuration diagram of a main part of the washing machine according to the first embodiment.

FIG. 3 is a flowchart illustrating a flow of a standard washing process in the washing machine according to the first embodiment.

FIG. 4 is a control flowchart at the time of a dehydration process in the washing machine of the first embodiment.

FIG. 5 is a control flowchart at the time of a dehydration process in the washing machine of the first embodiment.

FIG. 6 is a waveform diagram for explaining an operation of determining an eccentric load during a spin-drying process in the washing machine of the first embodiment.

FIG. 7 is a diagram illustrating an example of a change in the rotation speed of the washing / dewatering tub during the spinning cycle in the washing machine of the first embodiment.

FIG. 8 is a view showing an example of a change in the rotation speed of the washing and dewatering tub during the dehydration step in the washing machine of the first embodiment.

FIG. 9 is a control flowchart at the time of a dehydration process in the washing machine of the second embodiment.

FIG. 10 is a control flowchart at the time of a spin-drying process in the washing machine of the second embodiment.

FIG. 11 is a control flowchart at the time of a dehydration process in the washing machine of the second embodiment.

FIG. 12 is a diagram illustrating an example of a change in a rotation speed of a washing / dewatering tub during a spinning cycle in the washing machine according to the second embodiment.

FIG. 13 is a diagram illustrating an operation of determining an eccentric load during a spin-drying process in the washing machine according to the third embodiment.

FIG. 14 is a diagram illustrating an operation of determining an eccentric load during a spin-drying process in the washing machine according to the third embodiment.

FIG. 15 is a control flowchart at the time of a spin-drying process in the washing machine of the third embodiment.

FIG. 16 is a control flowchart at the time of a dehydration process in the washing machine of the third embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Housing | casing 2 ... Outer tub 5 ... Washing dehydration tub 7 ... Pulsator 8 ... Motor 11 ... Water inlet 13 ... Water supply valve 15 ... Drain valve 20 ... Control part 23 ... Inverter drive part 24 ... Rotation sensor 25 ... Load drive part 26 ... torque motor 27 ... clutch

Claims (14)

[Claims] 1. A single-tub type washing machine in which a washing and dewatering tub is rotatably provided inside an outer tub, comprising: a) a motor for rotating and driving the washing and dehydrating tub; Eccentricity to determine the magnitude of the eccentric load due to uneven distribution of the laundry contained in the washing and dewatering tub in a state where all or part of the water used in washing or rinsing before dehydration is stored in the washing and dehydrating tub Load determining means, c) when the eccentric load is determined to be large, by controlling the motor to rotate both or one of the washing and dewatering tub and the pulsator provided at the bottom of the washing and dewatering tub. And an operation control means for unraveling the laundry in the water stored in the washing and dewatering tub. 2. The washing machine according to claim 1, wherein the eccentric load determining means is configured to rotate the washing / dewatering tub at a predetermined low rotation speed at least during a period in which the washing / dewatering tub makes one rotation. A washing machine characterized in that the magnitude of an eccentric load is determined according to a change in a rotation speed. 3. The washing machine according to claim 2, wherein the eccentric load determining means determines that the eccentric load is large when the speed fluctuation amount or an index value corresponding thereto exceeds a predetermined allowable value. Features washing machine. 4. The washing machine according to claim 3, wherein the eccentric load determining means is configured to execute the eccentric load when the number of times that the speed fluctuation amount or an index value corresponding thereto exceeds a predetermined allowable value reaches a predetermined number. A washing machine characterized in that the washing machine is judged to be large. 5. The washing machine according to claim 2, wherein the predetermined low-speed rotation speed is set to a rotation speed lower than a resonance frequency of the washing and dewatering tub. 6. The washing machine according to claim 2, wherein the ratio of the amount of water to the laundry is reduced.
A washing machine for determining an eccentric load after draining a part of water stored in a washing and dewatering tub. 7. The washing machine according to claim 2, wherein the amount of water stored in the washing / dehydrating tub according to the load amount is set so that the ratio of the water amount to the load amount is substantially the same. A washing machine characterized in that a determination of an eccentric load is performed after a part is discharged. 8. The washing machine according to claim 3, wherein an allowable value for determining the eccentric load is changed based on the load amount and the amount of water stored in the washing / dewatering tub. A washing machine characterized by the following. 9. The washing machine according to claim 1, wherein the operation control means, when it is determined that the eccentric load is small, performs drainage while continuing rotation of the washing and dewatering tub. A washing machine characterized by starting a spin-drying operation after finishing. 10. The washing machine according to claim 1, wherein a central axis of the washing and dewatering tub is inclined at a predetermined angle with respect to a vertical line. 11. A washing and dewatering tub having: a) a cylindrical shape having a bottom with an open upper end surface, the central axis of which is inclined at a predetermined angle with respect to a vertical line; A motor that rotationally drives the motor; andc) determining means for detecting a change in the rotational speed of the motor and determining the degree of uneven distribution of the laundry in the washing and dewatering tub based on the change. Washing machine. 12. The washing machine according to claim 11, wherein
The determination unit includes a position detection unit that outputs a pulse signal corresponding to the rotation position of the motor, a calculation unit that calculates an index value corresponding to a speed change amount based on the pulse signal, and the index value is a predetermined value. An eccentric load determining means for determining that an eccentric load is large when the eccentric load exceeds an allowable value. 13. The washing machine according to claim 12, wherein
A washing machine characterized by counting the number of times that the index value exceeds an allowable value, and determining that the eccentric load is large when the count reaches a predetermined value. 14. The washing machine according to claim 12, wherein
A washing machine characterized by using a duty ratio of a pulse signal or a period ratio of two consecutive pulses as an index value.