JP3253546B2 - 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 capable of detecting the presence or absence of abnormal vertical vibration of a dewatering tub during a dewatering process.

[0002]

For example, in a fully automatic washing machine, a series of steps of washing, rinsing, and spinning are automatically performed. However, spinning of a spinning tub containing laundry is performed at a high speed. In the process of dehydration and dehydration rinsing, there is a problem that unbalanced rotation of the dehydration tub occurs due to unevenness of the laundry and abnormal vibration occurs. in this case,
The abnormal vibration includes not only horizontal vibration of the dehydration tub but also vertical vibration.

[0003] Conventionally, abnormal lateral vibration of the dehydration tub is detected by an unbalance detection switch that operates when the lateral vibration (lateral vibration) of the dehydration tub increases. In recent years, together with this, in order to cope with abnormal vibration in the vertical direction of the dewatering tank, a rotation sensor that detects the number of rotations of the motor is used, and the degree of increase in the number of rotations of the motor in the initial stage of the dehydration process is determined. When the degree of increase in the rotation speed is low, it is also determined that longitudinal vibration is occurring. When it is determined that abnormal vibration has occurred, the execution of dehydration is temporarily suspended, and an imbalance correction process (for example, a process of supplying water into the dehydration tub to loosen laundry) is performed.

However, according to the research by the present inventors, the detection of the presence or absence of the vertical vibration based on the detection of the degree of increase in the number of rotations of the motor is performed even if the dewatering tub itself has a certain weight. In a relatively lightweight dehydration tub (eg, made of plastic), even if longitudinal vibration occurs, the rotation speed of the dehydration tub is not hindered so much and the rotation speed of the motor increases. It turned out that the degree was almost the same as in the normal case. Therefore, in the conventional case, when the dewatering tank is relatively lightweight,
The vertical vibration of the dewatering tank cannot be detected effectively,
If the operation is continued as it is, the vibration in the vertical direction of the dewatering tub increases, and abnormal vibration and noise may occur.

The present invention has been made in view of the above circumstances, and an object thereof is to effectively eliminate abnormal vibration caused by vertical vibration of a dewatering tub during a dewatering process even when the dewatering tub is relatively lightweight. An object of the present invention is to provide a washing machine capable of preventing the washing.

[0006]

SUMMARY OF THE INVENTION A washing machine according to the present invention comprises: a power supply control means for controlling power supplied to a motor serving as a drive source of a dehydration tub; a rotation number detection means for detecting a rotation number of the motor; at the start of the dehydrating operation, the motor is or deenergized to lower the power supplied to the motor upon reaching a predetermined detection start rotational speed, the rotational speed is Tokoro motor at that time
A detecting operation execution means for executing a detecting operation to detect <br/> the required time taken for drops to the constant detection finish rotational speed, compared with the criterion time required detected by execution of the detecting operation The required time is less than or equal to a reference value, and
Determining means for determining that abnormal vibration is present when the value is larger than the lower limit; and determining that abnormal vibration has occurred by the determining means.
Means for executing an imbalance correction process when the time is set (the invention of claim 1).

[0007] According to this, in the dehydration process, as the power supply to the motor is started, the rotation speed of the motor and eventually the dehydration tub gradually increases toward a predetermined high-speed rotation speed. However, the detection operation executing means causes the motor to be cut off or the supplied power to be reduced during the ascent. Then, the rotation speed of the spin-drying tub gradually decreases. At this time, if the spin-drying tub is rotating stably without vibration, stable coasting rotation is performed, and thus the spin-drying tub and thus the motor rotation speed. Decreases slowly. On the other hand, when the unbalanced rotation of the dewatering tub occurs, regardless of whether the vibration direction is the vertical direction or the horizontal direction, the rotation speed of the dewatering tub and, consequently, the motor rotation speed decreases relatively sharply. Become.

Accordingly, the presence or absence of abnormal vibration of the dewatering tub can be determined by detecting the degree of decrease in the number of rotations of the motor at that time and comparing the degree of decrease with the determination reference by the determination means. At this time, even when the dewatering tub is relatively light, when the vertical vibration is generated, the degree of decrease in the rotation speed of the motor is sharp, and the generation of the vertical vibration can be detected well. It was confirmed.

[0009] In this case, specifically, together configured to detect the time required for the rotation speed of the motor is required to be reduced from the detection start rotational speed to a predetermined detection finish rotational speed, its
Required time is equal to or less than the reference value, and can and benzalkonium be determined that there is an abnormal vibration when larger than a predetermined lower limit value
You.

According to this, the degree of decrease in the number of revolutions of the motor during the detection operation can be detected as the required time, and when the required time is equal to or less than the reference value, it can be determined that there is abnormal vibration. Here, in a washing machine, a configuration in which the rotational force of a motor is transmitted to a dehydration tub through a mechanism such as a belt transmission mechanism is generally used. Although the rotation speed of the motor does not increase, the rotation speed of the motor may increase,
In this case, the degree of decrease in the number of rotations of the motor during the detection operation becomes extremely large. Therefore, when the above-mentioned required time is abnormally small, it is considered that the above-mentioned slippage has occurred instead of the vibration of the dehydration tub, so by providing a predetermined lower limit, the case where the above-mentioned slippage has occurred is eliminated, It is possible to more accurately determine the presence or absence of vibration of the dehydration tank.

[0011] The detection start rotation speed can be set near the resonance rotation speed of the dehydration tub (the invention of claim 2 ). The detection operation can be performed before the abnormal vibration increases.

[0012] Also, by special operation of the keys on the operation panel.
Enter the correction mode, and operate the operation panel in the correction mode.
According to the third aspect of the present invention, it is possible to change the determination criterion by operating a key of the motor. , It is possible to change the criterion to an appropriate one, and it is possible to cope with variations between products.

A mechanism for transmitting the driving force of the motor to the dewatering tank
Depending on the change with time, the criterion can also be configured to be automatically corrected (invention of claim 4). According to this, it becomes possible to automatically respond to a temporal change of the mechanism section and the like.

Further, at the start of the dehydration process, the degree of increase in the number of revolutions of the motor until the motor reaches the number of revolutions to start detection is detected, and when the degree of increase is greater than a predetermined value, the detection operation is executed. It may be canceled (the invention of claim 5 ). According to this, when the degree of increase in the number of revolutions of the motor is equal to or more than a predetermined value, it is considered that the mechanical portion has slipped as described above. Can be prevented.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Several embodiments in which the present invention is applied to a so-called one-tab type fully automatic washing machine will be described below with reference to the drawings.

(1) First Embodiment First, a first embodiment (corresponding to claims 1, 2 and 3 ) of the present invention will be described with reference to FIGS.

FIG. 2 schematically shows the entire structure of the washing machine according to the present embodiment. Here, an outer box 1 having a rectangular box shape is shown.
Inside, an outer tub 2 is provided via an elastic suspension mechanism 3. A dehydration tub 4 also serving as a washing tub is rotatably provided in the outer tub 2.
A stirrer 5 for generating a water flow is provided. The outer bottom of the outer tub 2 is provided with, for example, a motor 6 composed of an induction motor, and the rotational force of the motor 6 is transmitted via a belt transmission mechanism 7 so that the dehydration tub 4 and the stirrer 5 are removed. A drive mechanism section 8 that is driven to rotate is provided.

Although not shown or described in detail, the belt transmission mechanism 7 is configured by a belt stretched between a pair of pulleys, and the drive mechanism section 8 includes a clutch mechanism,
It has a speed reduction mechanism, a brake mechanism, and the like.
Thus, the agitator 5 is rotated forward and reverse by the motor 6 and the drive mechanism 8 during the washing and rinsing steps, and during the dehydrating (and dehydrating rinsing) steps, The dehydration tub 4 is rotated at high speed in one direction together with the stirring body 5.

The rotating shaft of the motor 6 includes:
As shown in FIG. 3, a rotation sensor 9 is provided as rotation number detecting means for detecting the rotation number of the motor 6. Although not shown in detail, the rotation sensor 9 is configured by, for example, providing a plurality of magnetic poles around a rotation axis of the motor 6 and arranging a Hall element in a fixed portion in the vicinity thereof.
A pulse signal corresponding to the number of rotations of the motor 6 (for example, eight pulses per rotation) is output.

A drain 10 for draining the water from the dewatering tub 4 is provided at the bottom of the outer tub 2. A drain hose 12 is connected to the drain 10 via a drain valve 11. I have. Further, at the bottom of the outer tub 2, a drain 13 for draining water from the outer tub is provided.
Are connected to the drain hose 12 via a drain passage (not shown).

On the other hand, a balance ring 14 is mounted on the upper end of the dewatering tub 4 and a dewatering hole 15 for discharging water from the dehydration tub 4 through the balance ring 14 during dehydration. Is provided. A substantially ring-shaped tub cover 1 is provided on the upper end of the outer tub 2.
The tub cover 16 is provided with an inner lid 17 for opening and closing the opening. The inner lid 17 has a concave portion 18 located on the rear side and having a number of water injection holes 18a.

Further, a top cover 19 is provided at the upper end of the outer box 1. The top cover 19 has a laundry entrance (not shown) and a lid 20 for opening and closing the entrance. A water supply valve 21 and a water supply mechanism 22 including a water injection case (not shown) having a detergent storage section are provided at a rear side portion of the top cover 19. With this,
With the opening of the water supply valve 21, water from a water supply source (tap water or bath water) passes through the water injection case, and the concave portion 18 of the inner lid 17.
The water is supplied into the dehydration tub 4 in the form of a shower from the water injection hole 18a.

On the rear side inside the top cover 19,
In the dehydration process (dehydration and dehydration rinsing process), an unbalance detection switch 23 for detecting abnormal lateral vibration of the dehydration tub 4 is provided. The unbalance detection switch 23 is composed of, for example, a micro switch, and is provided with a lever 24 positioned outside the upper end of the outer tank 2.
Is to be operated. Thus, when the outer tub 2 shakes sideways due to abnormal vibration (lateral shake) of the dewatering tub 4, the outer tub 2 comes into contact with the lever 24 and swings, so that the unbalance detection switch 23 is turned on. It has become.

Then, on the front side of the top cover 19,
An operation panel 25 (see FIG. 4) is provided on the upper surface, and a control device 26 is provided on the back surface thereof. The control device 26 includes a microcomputer, and controls a drive circuit, which will be described later, based on input of signals from the operation panel 25, the rotation sensor 9, the unbalance detection switch 23, a water level sensor (not shown), and the like. The motor 6 is controlled via the
1, the drain valve 11 and the like are controlled to execute the washing operation.

At this time, the operation panel 25 is
, A power key 27 for turning on / off the power, a start key 28 for starting and stopping the washing operation, a stroke key 29 for selecting a stroke,
A dry key 30 for selecting a dry mark course for clothing with a dry mark display is provided. Thus, based on the operation of the operation panel 25 by the user, a washing operation process such as washing, rinsing, and spin-drying is executed.

In addition, the operation panel 25 is provided with a stroke display section 31 for displaying a stroke and a detergent amount display section 32 for displaying an appropriate detergent amount. The process display unit 31 displays the processes of “washing”, “rinsing”, and “dehydration” with three LEDs 31a, 31b, and 31c, respectively.
The three LEDs 32a, 32b, 32c indicate "high", "medium", and "low" of the detergent amount, respectively. The displays on the display units 31 and 32 are also controlled by the control device 26.

FIG. 3 shows a configuration of a drive circuit of the motor 6. That is, a voltage / waveform detection circuit 34 for detecting the power supply voltage of the AC power supply 33, the zero crossing of the AC current waveform, and the power supply frequency is connected between one power supply line 33a and the other power supply line 33b of the AC power supply 33. Have been. The forward terminal 6a and the reverse terminal 6b of the motor 6 are connected to one power line 33a via triacs 35 and 36, respectively, and the common terminal 6c of the motor 6 is connected to the other power line 33b. .

The triacs 35 and 36 are turned on and off (off is naturally extinguished) by transistors 37 and 38, which are switching elements, respectively.
The transistors 37 and 38 are connected to the control device 26.
Is turned on and off. At this time, the control device 26 controls the power cut-off ratio (duty ratio) to the motor 6 to an arbitrary value by performing phase control that varies the timing (conduction angle) for turning on the triacs 35 and 36 in response to the detection of the zero-cross point. It can be controlled to a value, and thus functions as an energization control means for controlling the power supplied to the motor 6.

In the dehydration step (dehydration and dehydration rinsing steps), the control device 26 rotates the motor 6 at a predetermined high rotation speed to rotate the dehydration tank 4 at a high speed in the dehydration step (dehydration and dehydration rinsing steps). The dehydration operation is performed for a predetermined time (for example, about several minutes). At the start of the dehydration process, the motor 6 is fully energized (100% energized), as will be described in detail in the following flowchart. ,
When the motor 6 reaches a predetermined detection start rotation speed N1, the power supplied to the motor 6 is reduced, and a detection operation for detecting the degree of decrease in the rotation speed of the motor 6 at that time is executed. I have. At the same time, the presence / absence of abnormal vibration of the dewatering tub 4 is determined based on a comparison of the detected degree of descent with a determination reference. Therefore,
The control device 26 functions as a detection operation execution unit and a determination unit.

In this case, in this embodiment, as a manner of detecting the degree of decrease, the time required for the rotation speed of the motor 6 to decrease from the detection start rotation speed N1 to the predetermined detection end rotation speed N2 is detected. When the required time is equal to or less than the reference value t2 and is larger than a predetermined lower limit value t1, it is determined that there is abnormal vibration. When it is determined that abnormal vibration has occurred, the motor 6 is stopped, and an imbalance correction operation (for example, a process of supplying water into the dehydration tub 4 to loosen laundry) is performed.

Note that this detection operation is performed only during the initial 30 seconds of the start of the dehydration process, and thereafter, the operation is switched to full energization. Also, when the unbalance detection switch 23 is operated in the dehydration process, the motor 6 is stopped, and the unbalance correction process is performed.

More specifically, the above-mentioned detection start rotation speed N1 is set at 180 rpm, which is near the resonance rotation speed of the spin-drying tub 4.
And the detection end rotational speed N2 is set to 100 rpm from there.
It is set to 80 rpm, which decreases. And the reference value t
2 and the lower limit value t1 are obtained, for example, experimentally, and are set to 3.8 seconds and 1.0 seconds, respectively. Further, in the present embodiment, when the supply power is reduced, it is necessary to switch from full energization to two times.
The current is reduced to 0%. In this case,
The motor 6 may be turned off.

Further, as will be described later in the description of operation, in this embodiment, the operation panel 25 is operated by a special operation (a key operation which is not performed during normal use), as shown in FIG. It is possible to change (adjust) the reference value t2, which is a criterion, based on the correction table. This change is made at the time of factory shipment or at the time of maintenance by a service person.

Next, the operation of the above configuration will be described with reference to FIGS. The flowchart of FIG. 1 shows a procedure of a detection operation performed by the control device 26 in the dehydration process. When the dehydration process is started, first, a dehydration timer for measuring the dehydration time is started (Step S1), and full energization to the motor 6 is started (Step S2). By energizing the motor 6, the motor 6
As a result, the rotation speed of the dewatering tub 4 gradually increases. At this time, the rotation speed of the motor 6 is constantly monitored by the rotation sensor 9 (step S3).

In the next step S4, it is determined whether or not the rotation speed of the motor 6 has reached the detection start rotation speed N1 (for example, 180 rpm). When the rotation speed has reached the detection start rotation speed N1 (Yes), the required time is determined. At the same time as the detection timer for measuring the time is started (step S5), the power supplied to the motor 6 is reduced to 20% energization (step S5).
6). Due to such a decrease in the power supplied to the motor 6,
This time, the rotation speed of the motor 6 and eventually the dehydration tub 4 gradually decreases. Also at this time, the rotation speed of the motor 6 is constantly monitored by the rotation sensor 9 (step S7).

Next, when the rotation speed of the motor 6 decreases to the detection end rotation speed N2 (for example, 80 rpm) (step S8).
In step S9, it is determined whether the required time (time measured by the detection timer) is greater than the lower limit value t1 and equal to or less than the reference value t2.

Here, if the dehydration tub 4 has been rotating in a well-balanced manner without vibration at the time when the detection start rotation speed N1 has been reached, the inertia rotation of the dehydration tub 4 and thus the motor 6 continues for a relatively long time. Therefore, the rotation speed of the motor 6 gradually decreases, and as a result, the required time should be longer than the reference value t2. On the other hand, when the unbalanced rotation of the dewatering tub 4 occurs, the rotation speed of the dewatering tub 4 and thus the motor 6 decreases relatively sharply regardless of whether the vibration direction is the vertical method or the horizontal direction. Then, the required time becomes equal to or less than the reference value t2.

In this case, according to a study by the present inventors, when the dewatering tub 4 is relatively lightweight, the rate of increase in the number of revolutions of the motor 6 is normal (even when longitudinal vibration occurs). Although there is almost no change compared with the case where there is no vibration), when the degree of decrease in the rotation speed of the motor 6 is thus determined,
Even if the dewatering tub 4 is relatively light, it is confirmed that the descending degree becomes sufficiently large as compared with the normal state, and that the influence of the longitudinal vibration appears remarkably.

Therefore, if the required time exceeds the reference value t2, it can be determined that a normal dehydration operation is being performed. If the required time is less than the reference value t2, the dehydration operation including the longitudinal vibration can be performed with sufficient certainty. It can be determined that abnormal vibration of the water tank 4 is occurring. In the present embodiment, the lower limit
The value t1 is provided to determine that abnormal vibration of the dewatering tub 4 has occurred on the condition that the required time exceeds the lower limit value t1, and if the required time is less than the lower limit value t1, It was not determined that vibration was generated in the dewatering tank 4. The reason is as follows.

That is, as described above, the rotational force of the motor 6 is transmitted to the dewatering tub 4 via the belt transmission mechanism 7 and the drive mechanism section 8. If this occurs, the rotation speed of the motor 6 may increase even though the rotation speed of the spin-drying tub 4 does not increase, and the motor 6 may detect the influence of the inertial rotation of the spin-drying tub 4 during the detection operation. Otherwise, the number of revolutions suddenly drops. Especially motor 6
In the early stage of the energization of the belt (the initial stage of the dehydration process), the belt transmission mechanism 7 may easily slip. When such a slip occurs, the required time is much smaller than when the vibration occurs,
By providing the lower limit value t1, it is possible to eliminate the case where such slippage occurs.

When it is determined that vibration is generated in the dewatering tub 4 in this way (Yes in step S9)
s), the power supply to the motor 6 is stopped (step S1).
0) Then, an imbalance correction process is executed (step S11). After the unbalance correction process is performed, the process returns to step S1, and the dehydration process is performed again. On the other hand, when it is determined that vibration has not occurred in the dewatering tank 4 (No in step S9), the next step S9
At 12, it is determined whether the elapsed time from the start of dehydration measured by the dehydration timer is 30 seconds or less. If it is less than 30 seconds (No), the detection operation from step S2 is repeated again. .

If 30 seconds or more have elapsed (Yes in step S12), full energization of the motor 6 is performed (step S13), and thereafter, the motor 6 is driven at a predetermined top rotational speed (for example, 1000 rpm). Is reached, control is performed to maintain the rotation speed (step S14),
In other words, a normal dehydration operation is performed. This dehydration operation is performed for a predetermined dehydration time (step S15),
When the predetermined dehydration time has elapsed (Yes), the motor 6 is turned off (step S16), and the dehydration process ends.

By the way, a belt transmission mechanism 7 and a drive mechanism 8 for transmitting the rotational force of the motor 6 to the dewatering tub 4 are provided.
It is inevitable that the friction coefficient and the like of each part in the above-mentioned parts slightly vary among products, and there is a possibility that the easiness of the inertia rotation may also vary. Also, with respect to a single product, the easiness of the inertia rotation may vary due to a change with time such as a loose belt or a change in viscosity of grease. For this reason, if the reference value t2, which serves as a criterion for determining the occurrence of vibration as described above, is fixed, it may not be possible to cope with variations between products and changes over time.

Therefore, in this embodiment, the reference value t2 can be corrected by a special operation (hidden operation) of the operation panel 25 when the product is shipped from the factory or when maintenance is performed by a service person. It is. That is, as shown in FIG.
(3.8 seconds in this case), some correction values are represented by ranks, and by changing the ranks, the reference value t2 can be corrected. For example, if the current rank is “rank 7”, the reference value t2 is 3.8 seconds (correction value ± 0), but if this is changed to “rank 8”, the reference value t2 is 4.0 seconds ( The correction value is corrected to (+0.2 seconds).

The special operation to enter the correction mode is, for example, while simultaneously pressing the stroke key 29 and the start key 28,
This is performed by turning on the power key 27. After entering the correction mode, the rank changes one by one each time the start key 28 is pressed. At this time, four digits are displayed by using the LEDs constituting the display units 31 and 32. It is designed to display binary numbers. That is, as shown in FIG. 6, the LED 31a is the fourth digit,
31b is the third digit, LED32a is the second digit, LED32c
Corresponds to the first digit, and the rank is represented by a binary number.
Is lit (shown with hatching in FIG. 6 for convenience), and 0
Is turned off (indicated by a white circle in FIG. 6). Therefore, in the example of FIG. 6A, the rank is 7 at [0111], and in the example of FIG. 6B, the rank is 6 at [0110].

As described above, according to this embodiment, the presence or absence of vibration of the dewatering tub 4 is determined based on the degree of decrease in the number of revolutions of the motor 6 at the start of the dewatering stroke. Unlike the case in which the presence or absence of vibration of the dewatering tub is determined based on the degree of increase in the rotation speed, even when the dewatering tub 4 is relatively light, the vertical vibration of the dewatering tub 4 can be detected well. It is possible to prevent abnormal vibration and noise caused by vibration of the dewatering tank 4 beforehand.

Further, in the present embodiment, the lower limit value t1 is also used for judging the vibration, so that the occurrence of the vibration can be more reliably determined by eliminating the case where the mechanical portion slips. . In this embodiment, the detection start rotation speed N
Since 1 is set to 180 rpm, which is near the resonance frequency of the dewatering tub 4, even if abnormal vibration of the dewatering tub 4 occurs, the detecting operation can be completed before the abnormal vibration becomes large. Further, in the present embodiment, the judgment criterion (reference value t2) for judging the presence or absence of vibration can be corrected, so that it is always possible to make an accurate judgment by coping with variations between products and aging of the mechanism. Can be obtained.

(2) Other Embodiments Next, other embodiments (second to fifth embodiments) of the present invention will be described below in order. It should be noted that these second to fifth embodiments can be said to be modifications of the above-described first embodiment, and portions common to the above-described first embodiment are denoted by the same reference numerals and are newly added. The illustration and the detailed description are omitted, and different points will be mainly described.

[0049] Figure 7 is a second embodiment of the present invention (Claim 4
). In this embodiment, the criterion (reference value t2) is automatically corrected in accordance with the elapse of the operation period of the washing machine. That is, as described in the first embodiment, the driving force of the motor 6 is reduced by the dehydrating tub 4.
In the mechanism for transmitting to the motor, there is a case where the easiness of the inertia rotation is changed due to the aging change such as the looseness of the belt and the change of the viscosity of the grease, but in this embodiment, the software configuration of the control device 26 is used. Thus, the reference value t2 is increased by 0.2 seconds after the number of times of operation has elapsed twice, and the reference value t2 is increased by 0.4 seconds after the number of times of operation has elapsed 50 times.

According to this, there is an advantage that it is possible to automatically cope with a temporal change of the mechanism section and the like, and it is possible to always accurately determine the occurrence of vibration.

[0051] Figure 8 is a third embodiment of the present invention (Claim 5
). In this embodiment, at the start of the dehydration process, instead of immediately executing the above-described detection operation, first, the degree of increase in the rotation speed of the motor 6 is detected, and when the degree of increase is equal to or greater than a predetermined value, The belt transmission mechanism 7 is configured not to proceed to the detection operation by judging that the belt has slipped.

That is, when the dehydration process is started and the motor 6 is fully energized (step S2), the rate of increase in the number of revolutions of the motor 6 is determined in the next step S21.
Then, in step S22, it is determined whether or not the rate of increase is equal to or greater than a predetermined value R. If it is smaller than the predetermined value R (No), the same detection operation as in the first embodiment (step S3) is performed. After that) is executed.

Here, if the belt of the belt transmission mechanism 7 has slipped, the rate of increase in the rotation speed of the motor 6 becomes abnormally large. (Yes in step S22), when the rotation speed reaches N1 without proceeding to the detection operation (step S2).
3, S24), the power supplied to the motor 6 is reduced (step S25), and when the number of revolutions falls to the predetermined value N3 (steps S26, S27), the process returns to step S2 again. .

According to such a configuration, the detection operation is not performed when it is considered that the mechanical portion has slipped as described above, so that erroneous detection can be prevented, and the detection can be performed more reliably. It is possible to determine the occurrence of vibration.

FIG. 9 shows a fourth embodiment of the present invention. In this embodiment, in consideration of the fact that the belt is likely to slip in the belt transmission mechanism 7 at the beginning of the energization of the motor 6, the determination of the occurrence of vibration is not performed for a predetermined time t4 from the start of the dewatering process. In addition, the configuration is such that the determination as to whether or not vibration has occurred in the dewatering tub 4 is performed only after a predetermined time t4 has elapsed.

That is, when the dewatering process is started, the first
The detection operation is performed in the same manner as in the first embodiment (steps S1 to S8), but when the rotation speed of the motor 6 decreases to the detection end rotation speed N2 (80 rpm) (Y in step S8).
es) In the next step S31, it is determined whether or not a predetermined time t4 has elapsed since the start of the dewatering process.

If the predetermined time t4 has elapsed (Yes in step S31), step S9 is continued.
Is determined, if the predetermined time t4 has not yet elapsed from the start of the dehydration process (No), the process returns to step S2 without performing the determination. According to this, erroneous detection can be prevented even if there is a situation where the belt is likely to slip in the belt transmission mechanism 7 at the beginning of the energization of the motor 6.

FIG. 10 shows a fifth embodiment of the present invention. In this embodiment, the above criterion (reference value t
2) as shown in the figure, the power supply frequency (50 Hz or 60H
z?), the amount of laundry (either large, medium, or small) detected at the start of the washing operation, and the power supply voltage (three stages shown)
It is configured to change by: According to this, the determination of the occurrence of vibration can be performed more finely.

The present invention is not limited to the embodiments described above and shown in the drawings. For example , the present invention does not use a belt transmission mechanism for transmitting the driving force of the motor to the dewatering tub (so-called direct transmission). For example, the present invention can be applied to a drive-type washing machine, and can be appropriately modified and implemented without departing from the gist of the invention.

[0060]

As is apparent from the above description, according to the washing machine of the present invention, the detecting operation is executed in the early stage of the spin-drying process, and the spin-drying tub is operated based on the degree of decrease in the rotation speed of the motor at that time. Since the presence or absence of vibration is determined, even when the dewatering tub is relatively lightweight, it is possible to effectively prevent abnormal vibration caused by vertical vibration of the dewatering tub during the dewatering process. It has a practical effect.

[Brief description of the drawings]

FIG. 1 shows a first embodiment of the present invention, and is a flowchart showing a procedure of a detection operation in a dehydration process.

FIG. 2 is a longitudinal sectional side view showing the entire configuration of the washing machine.

FIG. 3 is an electric circuit diagram of a main part.

FIG. 4 is a plan view of an operation panel.

FIG. 5 is a diagram illustrating a relationship between a rank of a reference value and a correction value.

FIG. 6 is a plan view of a main part of an operation panel for explaining a method of changing a reference value.

FIG. 7 is a view showing a second embodiment of the present invention and showing a relationship between the number of times of operation and a correction value of a reference value.

FIG. 8 is a view corresponding to FIG. 1, showing a third embodiment of the present invention.

FIG. 9 is a view corresponding to FIG. 1, showing a fourth embodiment of the present invention.

FIG. 10 is a view showing a fifth embodiment of the present invention and showing a relationship between each condition and a reference value.

[Explanation of symbols]

In the drawings, 1 is an outer box, 2 is an outer tub, 4 is a dehydration tub, 6 is a motor, 7 is a belt transmission mechanism, 8 is a driving mechanism, 9 is a rotation sensor (rotation speed detecting means), and 23 is unbalance detection A switch, 25 indicates an operation panel, and 26 indicates a control device (power supply control means, detection operation execution means, determination means).

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Michiaki Ito 991, Anata-cho, Seto-shi, Aichi Prefecture, Toshiba Aichi Factory Co., Ltd. 72) Inventor Satoru Matsumoto 2-33-10, Meishi, Nishi-ku, Nagoya-shi Toshiba Abu E Co., Ltd. Nagoya Office (56) References JP-A-7-112094 (JP, A) JP-A-8-318085 (JP, A) JP-A-6-218180 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) D06F 33/02

Claims (5)

(57) [Claims] 1. A motor for driving a motor to rotate a dehydration tub to perform a dehydration process, comprising: an energization control unit for controlling electric power supplied to the motor; and a rotation speed detection unit for detecting a rotation speed of the motor. At the start of the dehydration process, when the motor reaches a predetermined detection start rotation speed, the power supplied to the motor is reduced or cut off, and the rotation speed of the motor at that time is detected by a predetermined detection speed.
A detecting operation execution means for executing a detecting operation to detect a required time required for the drop to finish rotational speed, comparing the required time detected by the execution of the detecting operation and determine <br/> constant reference, the The required time is below the reference value, and
One, a and <br/> determination means is abnormal vibration when greater than a predetermined lower limit value, the abnormal vibration is determined to have occurred by the judging means
Means for performing an imbalance correction process when the washing machine is in operation. 2. The detection start rotation speed is the resonance rotation speed of the dehydration tank.
The washing machine according to claim 1, wherein the washing machine is set near . 3. A correction by a special operation of a key on an operation panel.
Mode of the operation panel in the correction mode.
The washing machine according to claim 1 , wherein a criterion can be changed by a key operation . 4. A mechanism for transmitting a driving force of a motor to a dewatering tank.
The washing machine according to any one of claims 1 to 3, wherein the criterion is automatically corrected according to a change with time of the part . 5. The motor is detected at the start of the dehydration process.
The number of rotations of the motor until it reaches
The degree of rise was detected, and it was determined that the rise was
The washing machine according to any one of claims 1 to 4 , wherein execution of the detecting operation is stopped when the washing operation is performed.