JP3416573B2 - Washing machine - Google Patents

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 during startup of a dehydration 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 large number of dewatering holes are drilled inside the outer tub. The washing / dehydrating tank is rotatably arranged. During the dehydration operation, this washing / dehydrating tub is rotated at a high speed (for example, about 1000 rpm), and the centrifugal force causes water to be discharged from the laundry stored in the washing / dehydrating tub and splashed to the outer tub side through the dewatering hole. To do.

If the laundry is non-uniformly distributed around the rotating shaft of the washing / dehydrating tub and a so-called eccentric load is present, a swing vibration is generated when the washing / dehydrating tub is rotated, and it is extremely oscillated. The tank comes into contact with the housing and makes loud noise. In a conventional washing machine, this type of abnormal vibration detection device is provided with a safety lever swingably supported on the top plate of the housing so as to have a predetermined gap with the outer peripheral surface of the outer tub in a normal state. When the outer tub shakes greatly during the dehydration operation and comes into contact with this safety lever, the switch attached to the safety lever is turned off, whereby abnormal vibration of the outer tub is detected.

Further, in the conventional general washing machine, when it is detected that abnormal vibration occurs during the dehydration operation as described above, the dehydration operation is interrupted in order to eliminate uneven distribution of the laundry. It is designed to be loosened. Specifically, the rotation of the washing / dehydrating tub is stopped, the drain valve is closed, a predetermined amount of water is supplied into the washing / dehydrating tub, and the pulsator (stirring blade) is rotated to move the laundry in the water. .
After performing the unraveling operation for a predetermined time, the water stored in the washing / dehydrating tank is discharged, and the dehydration operation is tried again.

[0005]

The conventional washing machine described above has the following problems. In the case of the abnormal vibration detection method described above, the allowable range of the safety lever position, dimensional accuracy, switch sensitivity, shape of the contact portion between the outer tank cover and the safety lever, etc. is small, and despite small vibration due to variations. The switch may be activated and the washing time may be prolonged more than necessary. On the contrary, there is a possibility that the switch does not work well despite the large vibration, and the outer tub comes into strong contact with the housing to generate a large noise.

Further, in recent years, the gap between the outer tank and the housing has become narrower due to the large capacity and space saving, and the outer tank easily comes into contact with the housing even with a relatively small eccentric load. Therefore, measures are taken to prevent the loud noise from being generated when the outer tub comes into contact with the housing, such as molding the housing with a special material that uses a cushioning material, which increases the cost of the washing machine. It was a factor.

Further, if abnormal vibration occurs during the dehydration operation, the laundry is rearranged by the procedure of water supply → unraveling operation → drainage, which considerably extends the washing time. Therefore, in order to shorten the washing time, it is important to shorten the time required for the disassembling operation even if it is necessary.

The present invention has been made to solve such a problem, and an object thereof is to perform a washing time even when a loosening operation is required to eliminate uneven distribution of laundry during a dehydration operation. It is to provide a washing machine capable of suppressing the extension of the washing machine .

[0009]

Means for Solving the Problems, Embodiments and Effects of the Invention A washing machine according to claim 1, which has been made to solve the above problems, has a washing and dehydrating tub rotatably provided inside an outer tub. In the single-tank washing machine described above, a) a motor that rotationally drives the washing / dehydrating tub, and b) prior to dehydration, all or part of the water used for washing or rinsing before the dehydration is washed / dehydrated. Eccentric load determination means for determining the magnitude of the eccentric load due to uneven distribution of the laundry stored in the washing / dehydrating tub in the state of being stored in the tub; and c) washing when the eccentric load is determined to be large. By loosening the laundry in the water stored in the washing / dehydrating tub by controlling the motor to rotate both or either of the dehydrating tub and the pulsator provided at the bottom of the washing / dehydrating tub and a driving control means for the polarization
The heart load determination means is such that the washing / dehydrating tub is at a predetermined low rotation speed.
The eccentric load increases depending on the rotation speed fluctuation during rotation.
This is to judge the speed, and the amount of speed fluctuation
The number of times the index value exceeds the predetermined allowable value has reached the predetermined number.
It is characterized in that the eccentric load is judged to be large in the case of In the washing machine according to claim 2, the washing / dehydrating tank is an outer tank.
In a one-tank type washing machine rotatably installed inside, a) a motor for rotating the washing / dehydrating tub, and b) prior to dehydration, by washing or rinsing before dehydration.
All or part of the water used was stored in the washing / dehydrating tank
The uneven distribution of the laundry stored in the washing / dehydrating tank.
Eccentric load determining means for determining the magnitude of the eccentric load by c) , c) When the eccentric load is determined to be large,
Both pulsators provided at the bottom of the washing and dewatering tub
Or control the motor to rotate either one
By doing so, in the water stored in the washing and dewatering tank
And a driving control means for loosening the laundry, the polarized
The heart load determination means is such that the washing / dehydrating tub is at a predetermined low rotation speed.
The eccentric load increases depending on the rotation speed fluctuation during rotation.
The predetermined low rotation speed is set to a rotation speed lower than the resonance frequency of the washing / dehydrating tub.

In this type of washing machine, in order to loosen a plurality of laundry items intertwined with each other, it is necessary to rotate the washing / dehydrating tub and the pulsator in a state where at least enough water to immerse the entire laundry is stored in the washing / dehydrating tub. There is. The washing machine according to claim 1 does not discharge all the water used for washing and rinsing, but checks the magnitude of the eccentric load with at least a part of the water left in the washing / dehydrating tank, Is determined to be within the allowable range. When the eccentric load is large and it is determined that the loosening is necessary to eliminate the uneven distribution of the laundry, the operation control unit rotates both or one of the washing / dehydrating tub and the pulsator to store the stored water. Promotes loosening by moving laundry inside. If necessary, water may be replenished into the washing / dehydrating tank before performing the loosening.

According to this structure, even when the laundry is unevenly distributed in the washing / dehydrating tub and the loosening operation is performed, the water used for washing or rinsing immediately before that remains in the washing / dehydrating tub. Without supplying new water, or even if water is supplied, only a small amount of water needs to be supplied, and the time required for such water supply can be saved. Further, since the eccentric load can be determined again without draining after performing the loosening operation once, the time required for draining 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 a small amount of water may be supplied, so that there is a water saving effect that the amount of water used is small.

[0012]

Further, when the motor is controlled so that the washing / dehydrating tub rotates at a predetermined constant rotational speed, uneven rotation occurs if the laundry in the washing / dehydrating tub is unevenly distributed around the rotation axis. , Take out information according to the uneven rotation,
The magnitude of the eccentric load can be determined based on the information. Specifically, a pulse signal can be obtained from a rotation sensor attached to the motor, and the signal can be used to obtain a speed change amount or an index value corresponding thereto.

[0014]

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

[0016]

Further, according to the first aspect of the present invention , when the rotational unevenness temporarily occurs due to disturbance or the like, it is not immediately judged that the eccentric load is large, and more accurate judgment of the eccentric load is achieved. it can.

[0018]

Further, according to the second aspect of the present invention, even if the eccentric load is abnormally large, the magnitude of the eccentric load can be determined before the washing / dehydrating tub vibrates significantly.

[0020]

[0021]

[0022]

[0023]

[0024]

[0025]

[0026]

[0027]

[0028]

[0029]

[0030]

[0031]

[0032]

[0033]

[0034]

[0035]

[0036]

[0037]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of a washing machine according to the present invention (hereinafter referred to as "embodiment 1") will be described below with reference to the drawings. FIG. 1 is a side sectional view showing the structure of the washing machine of this embodiment. Inside the casing 1 of this washing machine, the outer tub 2 having a bottomed cylindrical shape is provided with front suspension rods 3 and rear suspension rods 4 (each one is visible in the figure, but two each are actually present). It is suspended so as to incline toward the front. Corresponding to the forward protrusion of the outer tub 2, the upper front portion of the housing 1 also projects. Inside the outer tub 2, a washing and dewatering tub 5 having a large number of dewatering holes on its peripheral wall is rotatably supported around a main shaft 6. A pulsator 7 for stirring the laundry is arranged at the bottom of the washing / dehydrating tub 5, and the outer tub 2
The rotational power of the motor 8 attached to the lower surface of the motor 8 is transmitted to the washing / dehydrating tub 5 and the pulsator 7 via a power transmission mechanism 9 including a motor pulley, a V-belt, and a main pulley, and a power switching mechanism 10. The power switching mechanism 10 includes a clutch, and mainly rotates only the pulsator 7 in one direction or both directions during a washing operation or a rinsing operation. Switch) to rotate.

At the rear of the upper part of the outer tub 2, a water injection port 1 equipped with a detergent container 11a for introducing the detergent contained therein is provided.
1 is provided. A water supply pipe 12 provided with a water supply valve 13 in the middle is connected to the water injection port 11. When the water supply valve 13 is opened, water flows into the water injection port 11 from an external water tap or the like through the water supply pipe 12. , Lower outer tank 2
Water is discharged from the water injection port 11 toward the inside. One end of a drain pipe 14 is connected to the front end portion of the bottom of the outer tub 2, that is, the lowest portion, 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 groove via a drain hose that can stand upright. The opening / closing operation of the drain valve 15 is related to the switching operation of the power switching mechanism 10 described above, and when the attached torque motor (not shown in FIG. 1) is not operating, the drain valve 15 is closed and the pulsator is closed. 7 is separated from the washing / dehydrating tub 5 and can rotate independently. When the torque motor is operated to pull the wire partway, the pulsator 7 and the washing / dehydrating 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 / dehydrating tank 5 are connected.

As described above, in the washing machine of this embodiment, the outer tub 2 and the washing / dehydrating tub 5 are inclined forward,
The upper surface opening faces forward rather than vertically upward. That is, the central axis CL of the outer tub 2 is arranged so as to be inclined with respect to the vertical line VL by a predetermined inclination angle α. Therefore, the user standing in front of this washing machine can wash
The bottom part of the laundry can be easily seen and the laundry can be easily taken out. Here, if the inclination angle α is in the range of about 5 to 20 degrees, the laundry can be taken out sufficiently easily, 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 electric system configuration diagram of a main part of the washing machine of this embodiment. At the center of control, CPU, RAM, RO
A control unit 20 including M, a timer and the like is installed. 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 water level of the water stored inside the outer tub 2. To be 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 operations 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 corresponding to its rotation, and the pulse signal is input to the control unit 20. The rotation sensor 24 is configured to include, for example, a magnet provided on the rotor of the motor 8 and a Hall element provided at a predetermined position of the stator. Three types of pulse signals having different phases are obtained. This structure will be described in detail later.

FIG. 3 is a flow chart showing the flow of a standard washing process in the washing machine of this embodiment. The operation of the washing machine will be briefly described with reference to FIG. When the start of washing is instructed, before washing water is supplied, the washing / dehydrating tank 5
The amount of laundry, that is, the amount of load, is detected (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 due to the pulsator 7 continues. Of course, the load amount detection is not limited to this method, and any method may be used. In the present embodiment, by detecting the load amount, the load amount is classified into four types, that is, a large amount, a medium amount, a small amount and an extremely small amount, and the washing water level at the time of subsequent washing and pool rinsing is increased according to each load amount. Water level, medium water level,
Set low and very low water levels.

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

Next, dehydration rinsing is performed as the first rinsing (step S4). In the dehydration rinsing, while rotating the washing / dehydrating tank 5, water is poured from the water injection port 11 into the laundry in a shower shape so that the laundry absorbs clean water, and instead, the detergent water soaked in the laundry is washed. It's about to be pushed out. Then, after the laundry is sufficiently watered, the intermediate dehydration is performed by the process of step S5 similar to step S3, and the water soaked in the laundry is scattered. Further, as a second rinsing step S
By the same processing of steps S6 and S7 as 4 and S5, dehydration rinsing and intermediate dehydration are performed, and a predetermined amount of water is supplied into the washing / dehydrating tank 5, and the pulsator 7 is rotated as in step S2. Thus, the accumulated rinsing is executed (step S8). When the pool rinsing is completed, the water in the washing / dehydrating tub 5 is drained, and the final dewatering is performed by rotating the washing / dehydrating tub 5 and the pulsator 7 integrally at high speed similarly to the intermediate dewatering (step S9).

The above procedure is standard,
Depending on the type of laundry and the like, the procedure is appropriately changed, for example, a pool rinsing is performed instead of the dehydration rinsing, or a water pouring rinsing is performed instead of the pool rinsing.

In the washing machine of the first embodiment, the washing is performed after the end of the process of stirring the laundry in a state where a predetermined amount of water is stored in the washing / dehydrating tank 5, such as washing and pool rinsing (or water rinsing). It is characterized by the control during the dehydration process (steps S3 and S9).

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

At the time when the washing and the rinsing are completed, the water used for the washing and rinsing is stored in the washing / dehydrating tank 5. The laundry is in a state of being stacked on the bottom of the washing / dehydrating tank 5 in the water. When the dehydration process is started, the control unit 20
Uses the load amount data already determined as described above, and executes a process for draining a part of the stored water according to the load amount. That is, first, the torque motor 26 is operated to open the drain valve 15 and start draining (step S10). Next, it is determined whether or not there is a large load (step S11). If the load is a large load, the amount of water that is a high water level decreases, and the high and medium water levels are set approximately midway between the high water level and the medium water level. When it reaches (“Y” in step S12), the process proceeds to step S18, and the drain valve 1
Close 5 to stop draining. Further, when the load is medium (“Y” in step S13), when the amount of water as the medium water level decreases to reach the low water level (“Y” in step S14), the load is small. (“Y” in step S15) When the water amount that is a low water level decreases and reaches an extremely low water level (“Y” in step S16), if neither a large load, a medium load, or a small load, that is, When the load is extremely small, when the amount of water that is the extremely low water level decreases and reaches the ultra extremely low water level that is set at a position lower than the extremely low water level (“Y” in step S17), The drain valve 15 is closed to stop drainage (step S1).
8). Thus, in the above-mentioned processing, the smaller the load amount is, the larger the ratio of the drainage amount to the water amount is stored as the wash water level. The reason for performing such drainage control will be described later.

Next, the laundry laminated on the bottom of the washing / dehydrating tank 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).
Also, the torque motor 26 is operated to pull the wire partway, and the drain valve 15 is closed while the clutch 27 is being closed.
Thus, the washing / dehydrating tank 5 and the pulsator 7 are connected so as to rotate integrally (step S20). In this state, the control unit 20 activates the motor 8 via the inverter drive unit 23 to increase the rotation speed of the motor 8 to 30 rpm (step S21). At this time, the ratio (reduction ratio) of the rotation speed of the motor 8 and the rotation speed of the washing / dehydrating tub 5 is about 1.5. Therefore, the rotation speed of the washing and dewatering tank 5 is about 20r.
pm.

When the washing / dehydrating tub 5 is rotated at a high speed when the dewatering is started after the washing is completed, the detergent water stored in the washing / dehydrating tub 5 is vigorously agitated, and an abnormally large amount of bubbles are generated. There is a high possibility that bubbles will spout upward from the narrow gap between the washing and dewatering tank 5. According to the experiments conducted by the inventors of the present application, such an abnormal occurrence of bubbles can be avoided if the rotation speed of the washing / dehydrating tank 5 is about 30 rpm or less. Therefore, it is preferable to keep the rotation speed within the range. . Further, although it is not necessary to consider the problem of generation of bubbles at the time of starting dehydration after the completion of pool rinsing (because there is almost no detergent contained in water), the transverse resonance frequency of the washing / dehydrating tank 5 is 65 to 100 rpm.
Therefore, it is preferable to set the rotation speed at least lower than the resonance frequency.

Immediately after the motor 8 is turned on as described above, the control unit 20 starts time counting by the timer (step S2).
2). The rotation speed of the washing / dehydrating tub 5 increases, for example, as shown by the solid line L1 or the dotted line L2 in FIGS.
When the speed reaches m, the speed is controlled to be almost constant. Although the speed increase depends on the load amount, even when the load amount is large, the rotation speed of the washing / dehydrating tub 5 reaches 20 rpm when t1 has elapsed since the motor 8 was turned on. The control unit 20 starts calculation of the speed change amount ΔV based on the pulse signal obtained from the rotation sensor 24 at the time when the timer counts t1 (“Y” in step S23) (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 relative to each other during one rotation of the motor 8. Square wave pulse signals of two different periods (shifted in phase by about 60 °) are output (see FIG. 6A). When the time of one cycle of this pulse signal is T, the reciprocal of T (1 / T) is the velocity V.

If the laundry is unevenly distributed inside the washing / dehydrating tub 5 arranged in an inclined manner as in the present embodiment, the eccentric load is accelerated as the rotation advances downward in the inclination, and the eccentric load is increased. Is decelerated as it goes up the slope. Therefore, FIG.
As shown in (c), speed fluctuations that are synchronized with the rotation of the washing / dehydrating tub 5, that is, uneven rotation, occur. Acceleration and deceleration due to such an eccentric load are remarkable due to the configuration in which the washing / dehydrating tub 5 is inclined, but even if the washing / dehydrating tub 5 is not inclined, the acceleration / deceleration is caused by the eccentric load. When the washing / dehydrating tub 5 swings in the horizontal direction, the friction between the rotating shaft and the bearing fluctuates, and thus uneven rotation in synchronization with the rotation similarly occurs.

The speed V is the timing of the rising edges of the pulse signals of three systems (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 taken as the speed change amount ΔV. . That is, .DELTA.V = Vn + 1-Vn.

When the speed V fluctuates as shown in FIG. 6 (c), the speed change amount ΔV fluctuates as shown in FIG. 6 (d). The larger the eccentric load, the larger the rotation unevenness, and the larger 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 / dehydrating tub 5 is calculated as the maximum speed change amount amplitude ΔA, which is used for the determination of 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 10 times as described above (step S25). For example, in the example of FIG. 6, the speed change amount ΔV is calculated at the timing of P1 to P10. Since the time required for the washing / dehydrating 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), the speed change amount ΔV is set to 10 When the number of times of calculation is calculated, the washing and dewatering tub 5 has rotated at least once at that time. The control unit 20 determines whether or not the determination number counter value N1 is 4 (step S
26) When it is less than 4, ΔVmax and ΔVmin among the 10 speed change amounts ΔV obtained by the above 10 calculations
And the maximum amplitude ΔA of the speed change amount is calculated (step S27). Then, it is determined whether or not the maximum velocity change amount amplitude ΔA is larger than a predetermined threshold value (step S28). This threshold is experimentally determined in advance.

As described above, the rotation speed of the washing / dehydrating tub 5 varies depending on the eccentric load caused by the uneven distribution of the laundry.
Water is stored inside the washing / dehydrating tank 5, and the occurrence of rotational unevenness is affected by this water. That is, when the amount of water is large, the influence of the eccentric load is reduced by the weight of the water, so even if the magnitude of the eccentric load due to uneven distribution of 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, as described above, the washing water level at the time of washing or pool rinsing, that is, the washing water amount is changed according to the load amount.The ratio of the water amount to the load amount shows that the water amount decreases as the load amount decreases. The ratio will increase. For this reason, if the above-described determination of the eccentric load is carried out while holding all the water supplied during washing or rinsing, the smaller the load is, the smaller the speed change becomes, and the accurate determination becomes difficult. Further, even with a large amount of load, the rotation unevenness is not so remarkable in the state where the high water level is maintained, and there is a possibility that the determination of the eccentric load may be inaccurate.

Therefore, in the present washing machine, as described above, when the load amount is large, a relatively small amount of water among the water stored in the washing / dehydrating tank 5 is discharged, and the smaller the load amount is, , The relative proportion of the amount of wastewater is increased. This reduces the water volume overall,
The ratio of the amount of water to the amount of load is kept almost constant regardless of the amount of load. As a result, even when the load amount is relatively small, the eccentric load is likely to be reflected in the rotation unevenness, and moreover, the same threshold value can be used to determine the maximum velocity change amount amplitude ΔA.

The control unit 20 determines that the eccentric load is abnormally large when the maximum velocity change amount amplitude ΔA is larger than the threshold value thus determined, and the abnormality 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 judgment number counter value N1 is incremented (step S31), and the process returns to step S24. If it is determined in step S28 that the maximum velocity change amount amplitude ΔA is equal to or less than the threshold value, the determination count counter value N1 is incremented without incrementing the abnormality count counter value N2, and the process returns to step S24.

Now, assume that the laundry is actually unevenly distributed and the eccentric load is abnormally large. In this case, when the judgment number counter value N1 is "0", the above step S
After the abnormality number counter value N2 becomes "1" by the processes of 24 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 abnormality number counter value N2 becomes "2", and step S3
At 0, it is determined that this N2 is 2, and the process proceeds to step S32. Steps S32 to S36 are processes of a loosening process for eliminating uneven distribution of laundry.

When it is determined in step S28 that the maximum speed change amount amplitude ΔA exceeds the threshold value, the speed change amount maximum amplitude ΔA does not reach the threshold value by using the abnormality counter without immediately proceeding to the loosening process. When it is judged that it is over, the loosening process is performed. Therefore, it is undesired when the speed does not actually fluctuate due to the eccentric load, for example, when the maximum amplitude ΔA of the speed change amount exceeds the threshold value due to a very short time disturbance or electrical noise. It is possible to prevent the loosening operation from being performed.

In the loosening process, the control unit 20 once turns off the motor 8 to stop the washing / dehydrating 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 the above step S
Water supply is continued until the original water level before the wastewater treatment of 10 to S18 is restored (step S34). After returning to the original water level, the water supply valve 13 is closed (step S35). Here, the reason why the water level is restored by water supply is that if the amount of water is too small in the subsequent loosening operation, the laundry does not move sufficiently in the water, and it is difficult to obtain the desired loosening effect. In this washing machine, a small amount of water is discharged before the eccentric load is judged, and the reduced amount of water is replenished after the eccentric load is judged. Since the total amount of water stored in the washing / dehydrating tank 5 is small, the water used for washing and rinsing can be effectively reused.
Also, the time required for water supply is short.

After the water is supplied as described above, first, the washing / dehydrating tank 5 and the pulsator 7 are integrally united in the forward rotation direction to about 1 degree.
The washing / dehydrating tub 5 and the pulsator 7 are disengaged from each other, and the pulsator 7 is rotated about one revolution in the reverse direction. At this time, since the washing / dehydrating tub 5 is rotating in the normal direction by inertia, the washing / dehydrating tub 5 and the pulsator 7 rotate in mutually opposite directions, 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 water to facilitate loosening. After that, the pulsator 7 is rotated for a predetermined time (about 2 minutes) while being reversed in both the forward and reverse directions for a short time. As a result, the entangled laundry is loosened and dispersed evenly around the rotation axis. After performing such a loosening operation, the process returns to step S19, and the eccentric load determination operation is executed again.

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

When no abnormality is detected and the above determination is repeated four times, the determination number counter value N is determined in step S26.
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 / dehydrating tank 5 is continuously rotated at about 20 rpm. By performing drainage while rotating the washing / dehydrating tub 5 in this manner, it is possible to prevent the laundry from moving toward the connection portion side of the drain pipe 14 due to the effect of the drained water flow.

The control unit 20 detects the water level in the washing / dehydrating tub 5 by the water level sensor 22, and if the water level has dropped to the reset water level set at a position close to the bottom of the washing / dehydrating tub 5 (in step S38, " Y "), the motor 8 is turned off to stop the rotation of the washing / dehydrating tub 5 (step S39). By stopping the rotation of the washing / dehydrating tub 5, the water remaining at the bottom of the outer tub 2 is smoothly discharged. Then, 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 / dehydrating tub 5 (step S41) to execute dehydration (step S41). Step S42). As shown in FIG. 7, the rotation speed of the washing and dewatering tub 5 is a predetermined dewatering rotation speed (1000
After being increased to about rpm), it is maintained almost constant. Then, if the predetermined dehydration time has elapsed (step S4
3, the control unit 20 turns off the motor 8 and ends the dehydration process (step S44).

In the case of a conventional washing machine, in order to perform the above-described loosening operation, it is necessary to once perform water supply up to a predetermined water level, perform the loosening operation, and then drain all the water. However, in the washing machine of Example 1 above,
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 tank 5, it is not necessary to perform a large amount of water supply or drain even when performing the loosening operation. Therefore, the time required for loosening operation can be shortened.

In the above embodiment, as described above, in order to make the threshold value for judging the maximum amplitude ΔA of speed change amount the same value irrespective of the load amount, the amount of remaining water is first drained. Is being adjusted. Of course, instead of first performing the drainage, the threshold value for determining the maximum speed change amount amplitude ΔA may be changed according to the load amount. That is,
In this case, when the load amount is small, the ratio of the water amount to the load amount becomes relatively large, and the influence of water makes it difficult for the eccentric load to be reflected in the rotation unevenness. Therefore, the threshold value is made smaller, and the smaller maximum speed variation amplitude ΔA Therefore, it may be determined that the eccentric load is abnormal.

Next, a washing machine according to a second embodiment of the present invention (hereinafter referred to as "embodiment 2") will be described. Since the structure of this washing machine is the same as that of the washing machine according to the first embodiment, its explanation 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 finished, all the water remaining in the washing / dehydrating tank 5 is once discharged to start the dewatering operation, and the operation is performed. The eccentric load is determined based on the uneven rotation of the motor 8 in the initial stage of.

FIG. 12 is a diagram showing changes in the basic rotation speed during the dehydration process in the washing machine of the second embodiment. As described above, in this type of washing machine, the washing / dehydrating tub 5 has a horizontal resonance frequency and a vertical resonance frequency, and the horizontal resonance frequency is the rotational speed of the washing / dehydrating tub 5. 65-1
About 00 rpm, longitudinal resonance frequency is 130-200
It is about rpm. Of course, this value also depends on the size, weight, load amount, etc. of the washing / dehydrating tank 5. Since the vibration of the outer tub 2 becomes large in the vicinity of such a resonance frequency, it is preferable to pass the vicinity of these resonance frequencies as quickly as possible when increasing the rotation speed. Therefore,
In this washing machine, after the motor 8 is started to start the rotation of the washing / dehydrating 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, the rotational speed of the washing / dehydrating tub 5 is controlled to be substantially constant at a rotational speed of about 120 rpm, which is between the resonance point in the horizontal direction and the resonance frequency in the vertical direction, and the eccentric load is determined in that state. . At this time, if it is determined that the eccentric load is small, the motor 8 is accelerated so as to quickly pass the rotation speed corresponding to the longitudinal resonance frequency, and after passing the rotation speed, the laundry removal speed is about 240 rpm. The rotation speed of the water tank 5 is controlled so as to be maintained 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.

9 to 11 are flowcharts showing the procedure at the time of the dehydration process for realizing the rotation control as described above. Hereinafter, the control operation of the dehydration process of the washing machine of the second embodiment will be described with reference to FIGS. 9 to 12.

Upon completion of washing and rinsing, the control unit 20
Operates the torque motor 26 to open the drain valve 15 (step S50). As a result, the water stored in the outer tub 2 is discharged to the outside. When the predetermined drainage time has elapsed, the control unit 20 activates the motor 8 via the inverter drive unit 23, and the rotation speed of the motor 8 is 180 rpm.
The control is performed so as to increase to (about 120 rpm at the rotation speed of the washing / dehydrating tank 5) (step S51).

Immediately after turning on the motor 8 as described above,
The control unit 20 starts time counting by the 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 time measured by the timer has passed t1 (step S55). Until the time t1 elapses, it is determined whether the rotation speed V'of the washing / dehydrating tank 5 has reached a predetermined rotation speed Va (120 rpm in this example) (step S
56), acceleration control is performed until the rotation speed V ′ reaches Va (step S57). As a result, the rotation speed increases as shown in FIG.

As described above, the speed change amount ΔV is calculated 10 times in succession in order to obtain the speed change amount ΔV during the period in which the washing / dehydrating tub 5 makes at least one rotation (step S6).
4). After that, it is determined whether or not the determination number counter value N1 is 10 (step S65), and when it is less than 10, it is the minimum of the 10 speed change amounts ΔV obtained by the above 10 times of calculation. It is determined whether or not the speed change amount ΔVmin is larger than a predetermined threshold value (step S6).
6). This threshold is experimentally determined in advance.

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

Now, assume that the laundry is actually unevenly distributed and the eccentric load is abnormally large. In this case, when the judgment number counter value N1 is "0", the above step S
After the abnormality number 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 count value N2 becomes "2" by the processing of steps S55 to S57 and S64 to S67. When this is repeated and it is determined in step S68 that the abnormality number counter value N2 is 3, the process proceeds to step S70, and a loosening process for eliminating uneven distribution of laundry is executed. In the loosening process, the motor 8 is stopped (step S
70) and close the drain valve 15 (step S7).
1). Then, the water supply valve 13 is opened (step S
72) After supplying water until the water level in the washing / dehydrating tub 5 reaches a predetermined water level (“Y” in step S73), the rotation control of the washing / dehydrating tub 5 and the pulsator 7 as described above is executed in the loosening operation. (Step S74). After that, the torque motor 26 is operated to open the drainage valve 15 (step S75), and when a predetermined drainage time has elapsed (“Y” in step S76), the process returns to step S51 to restart the dehydration operation. To do.

At step S66, the minimum speed change amount ΔVmi
Even if it is determined that n is less than or equal to the threshold, step S
Until it is determined at 64 that the determination count counter value N1 has reached 10, the steps S55 to S57 and S64 to
The process of S69 is repeated. Therefore, if the abnormality is detected three times while the determination is repeated ten times, the above-described loosening process is performed.

When no abnormality is detected and the above determination is repeated 10 times, the determination number 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 this constant speed control period, the speed change amount ΔV is calculated 10 times (step S77). Then, it is determined whether or not the determination count counter value N1 is 10 (step S78), and if it is less than 10,
The maximum speed change amount ΔVmax and the minimum speed change amount ΔVmin are found among the 10 speed change amounts ΔV obtained by the above 10 calculations, and the maximum speed change amount amplitude ΔA is calculated (step S79). The process of steps S79 to S83 is the same as steps S28 to S31 of the first embodiment except that the threshold value for determining N2 is different.

When it is determined that there is an abnormal eccentric load based on the maximum speed variation amplitude ΔA while the rotational speed V ′ is maintained near Va, the loosening stroke is executed. When the time measured by the timer exceeds t1 (step S55
Then, "Y"), and the control unit 20 next determines whether or not the time has passed t2 (step S58). Until the time reaches t2, it is determined whether or not the rotation speed V'of the washing / dehydrating tub 5 is Vb (step S59), and predetermined acceleration control is executed until it reaches Vb (step S57). At that time, the eccentric load is determined in the same manner as in the previous acceleration to the rotational 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 the previous constant speed.

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

When the timer reaches t2 without determining that there is an abnormal eccentric load ("Y" in step S58), the rotation speed of the washing / dehydrating tank 5 is the dehydration rotation speed Vc. The motor 8 is controlled so as to ascend to and dehydration is performed (step S61). Then, when the time measured by the timer reaches the predetermined dehydration time t3 ("Y" in step S62), the motor 8 is turned off (step S6).
3), the dehydration process is completed.

Next, a washing machine according to a third embodiment of the present invention (hereinafter referred to as "embodiment 3") will be described. Since the basic structure of this washing machine is the same as that of the washing machines according to the above-mentioned first and second embodiments, a description thereof will be omitted. The washing machine according to the third embodiment is different from the above-described two embodiments in the method of detecting uneven rotation.

Therefore, first, this detection method will be 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 the motor 8
Is rotating at a constant speed, its duty ratio (W1
/ T1) is almost 0.5. However, when the motor 8 has uneven rotation, the duty ratio changes. When the duty ratio of any of the pulse signals is continuously measured, as shown in FIG. 14, the duty ratio fluctuates about 0.5 in synchronization with the rotation of the washing / dehydrating tub 5. The fluctuation width ΔD corresponds to the size of the rotation unevenness, that is, the size of the eccentric load. Therefore, when the duty ratio exceeds a certain threshold, it can be estimated that the eccentric load is abnormally large.

Further, instead of the duty ratio, the cycle ratio of two consecutive pulse signals, that is, T1 / (T1 + T
2) may be used. If the cycle ratio is used, even a configuration in which the duty ratio of the pulse signal does not become 0.5 at a constant rotation speed can be applied.

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

Upon completion of washing and pool rinsing, the control unit 20
Operates the torque motor 26 to open the drain valve 15 (step S100). As a result, 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 drive unit 23, and the rotation speed of the motor 8 is 180 rp.
It is controlled so as to rise to m (about 120 rpm at the rotation speed of the washing / dehydrating tank 5) (step S101).

Immediately after turning on the motor 8 as described above,
The control unit 20 starts time counting by the timer (step S1
02), the abnormality number counter value N2 is reset (step S103), and it is determined whether the time measured by the timer has passed t1 (step S104). Until t1 elapses, it is determined whether or not the rotation speed V'of the washing / dehydrating tank 5 has reached a predetermined rotation speed Va (120 rpm in this example) (step S105), and the rotation speed V'reaches Va. Up to step S1 (step S106), and step S1
Return to 04.

When the rotation speed V ′ reaches Va, step S
The routine proceeds from 105 to S109, where constant speed control is performed so as to maintain the rotation speed V ′ near Va. During the constant speed control period, 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 the duty ratio D exceeds a threshold value (step S114). If it exceeds the threshold value, the abnormality number counter value N2 is incremented (step S115), and it is determined whether the N2 has reached the predetermined value P (step S116). If N2 has not reached P, the process returns to step S104. If the duty ratio D is less than or equal to the threshold value 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 while the washing / dehydrating tub 5 is maintained at a constant speed.
The number of times the threshold is exceeded is integrated.

Now, when the uneven distribution of laundry is actually serious and the eccentric load is abnormally large, the abnormality count counter value N2
Reaches a predetermined value P, steps S116 to S117
Proceed to and perform a loosening process to eliminate uneven distribution of laundry. In the loosening process, the above steps S70 to S7.
The processing of steps S117 to S123 similar to 6 is executed.

When the time measured by the timer has passed t1 ("Y" in step S104), the control unit 20 next measures the time t.
It is determined whether 2 has passed (step S107).
Until the time reaches t2, it is determined whether or not the rotation speed V'of the washing / dehydrating tub 5 is Vb (step S108),
Predetermined acceleration control is executed until Vb is reached (step S106). After the rotation speed V ′ reaches 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 in the same manner as in the previous constant speed. It If the abnormal number counter value N2 accumulated during the two constant speed control does not reach the predetermined value P, it is determined that there is no abnormally large eccentric load, and at the time when the timer reaches t2 (at step S107). "Y"), the rotation speed of the washing and dewatering tank 5 is the dewatering rotation speed Vc
The motor 8 is controlled so that the temperature rises up to (step S110). Then, when the time measured by the timer reaches t3 which is a predetermined dehydration time (step S111)
Then, the motor 8 is turned off (step S112), and the dehydration process ends.

As described above, in the washing machines of Embodiments 2 and 3, the magnitude of the eccentric load is determined based on the rotation unevenness of the washing / dehydrating tub when the dewatering operation is started, and when the eccentric load is large, The loosening operation is executed, and the high-speed dewatering operation is executed when the eccentric load is small. 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 dehydration operation.

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

[Brief description of 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 electrical system configuration diagram of a main part of the washing machine of the first embodiment.

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

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

FIG. 5 is a control flowchart for a dehydration process in the washing machine according to the first embodiment.

FIG. 6 is a waveform diagram for explaining the operation of eccentric load determination during the dehydration process in the washing machine of the first embodiment.

FIG. 7 is a diagram showing an example of changes in the rotation speed of the washing / dehydrating tub during the dewatering process in the washing machine of the first embodiment.

FIG. 8 is a diagram showing an example of changes in the rotation speed of the washing / dehydrating tub during the dewatering process in the washing machine of the first embodiment.

FIG. 9 is a control flowchart for a dehydration process in the washing machine according to the second embodiment.

FIG. 10 is a control flowchart for a dehydration process in the washing machine according to the second embodiment.

FIG. 11 is a control flowchart for a dehydration process in the washing machine according to the second embodiment.

FIG. 12 is a diagram showing an example of changes in the rotation speed of the washing / dehydrating tub during the dewatering process in the washing machine of the second embodiment.

FIG. 13 is a diagram for explaining the operation of eccentric load determination during the dehydration process in the washing machine of the third embodiment.

FIG. 14 is a diagram for explaining the operation of eccentric load determination during the dehydration process in the washing machine of the third embodiment.

FIG. 15 is a control flowchart for a dehydration process in the washing machine according to the third embodiment.

FIG. 16 is a control flowchart for a dehydration process in the washing machine according to the third embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Housing 2 ... Outer tub 5 ... Washing / dehydrating tub 7 ... Pulsator 8 ... Motor 11 ... Water injection port 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 (2)

(57) [Claims] 1. A one-tank type washing machine in which a washing / dehydrating tub is rotatably provided inside an outer tub, wherein: a) a motor for rotationally driving the washing / dehydrating tub; and b) prior to dewatering. Eccentricity to determine the magnitude of eccentric load due to uneven distribution of the laundry stored in the washing / dehydrating tub when all or part of the water used for washing or rinsing before dehydration is stored in the washing / dehydrating tub Load determining means, and c) by controlling the motor so as to rotate either or both of the washing / dehydrating tub and the pulsator provided at the bottom of the washing / dehydrating tub when it is determined that the eccentric load is large. And operation control means for unraveling the laundry in the water stored in the washing / dehydrating tub , wherein the eccentric load determining means causes the washing / dehydrating tub to rotate at a predetermined low speed.
Eccentric load according to the rotation speed fluctuation when rotating at speed
It is to judge the size of the weight,
The number of times that the index value according to
The washing machine is characterized in that it is determined that the eccentric load is large when it reaches the limit . 2. A washing / dehydrating tub is rotatably provided inside the outer tub.
In a single-tank washing machine equipped with a scraper , a) a motor for rotating the washing and dewatering tub, and b) prior to dewatering, by washing or rinsing before dewatering.
All or part of the water used was stored in the washing / dehydrating tank
The uneven distribution of the laundry stored in the washing / dehydrating tank.
Eccentric load determining means for determining the magnitude of the eccentric load by c) , c) When the eccentric load is determined to be large,
Both pulsators provided at the bottom of the washing and dewatering tub
Or control the motor to rotate either one
By doing so, in the water stored in the washing and dewatering tank
Operation control means for unraveling the laundry, wherein the eccentric load determination means is such that the washing / dehydrating tub rotates at a predetermined low speed.
Eccentric load according to the rotation speed fluctuation when rotating at speed
This is to determine the size of the weight, and furthermore, the predetermined low speed rotation speed depends on the resonance frequency of the washing and dewatering tank.
A washing machine characterized by being set at a rotation speed that is even lower .