JP2001120881A - Drum type washing machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance the precision of unbalance detection and shorten the time required for the detection. SOLUTION: In spinning a fixed power is supplied to a motor (step Q1), and rotating speeds T0-T11 during rotation of the motor 1 are detected in this state (step Q3). An average value Tave is determined on the basis of the rotating speeds T0-T11 (step Q4), an integrated value S that is the parameter of degree of fluctuation is calculated (step Q5), and the unbalance rotation of a drum is detected according to this integrated value S (step Q6).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drum type washing machine for detecting imbalance.

[0002]

SUMMARY OF THE INVENTION In a drum type washing machine,
As is well known, a water tank is provided in an outer box, a drum is provided in the water tank so as to be rotatable around a substantially horizontal axis, and the rotation of the motor is transmitted to the drum via a belt transmission mechanism. There is. The belt transmission mechanism has a configuration including a driving pulley, a driven pulley, and a belt.

[0003] On the other hand, in this type of drum type washing machine, during dehydration, a state in which the laundry (object to be dehydrated) is stuck to the inner peripheral surface of the drum, and the laundry is attached to the inner peripheral surface of the drum. If the drum is unevenly distributed, the drum will rotate unbalanced. For this reason, detection of unbalance rotation of the drum at the time of dehydration is performed. That is, during a predetermined period of the spin-drying operation, the degree of change in the rotation speed of the drum (the rising state of the rotation speed) is detected, and the unbalance rotation of the drum is detected based on the degree of change.

However, in the above-described conventional apparatus, since the motor and the drum are transmitted by the belt, the drum vibrates or slips, and the unbalance state of the drum is directly changed as the degree of change in the rotation speed of the drum. There is a problem that the reliability of the unbalance detection accuracy is not always high. Although it is conceivable to detect the rotation speed of the motor, this is also difficult because the motor and the drum do not rotate synchronously. In addition, there is a problem that the time required for the detection becomes long because the state of change of the rotation speed during the rotation of the drum many times is observed. The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a drum-type washing machine that can improve the unbalance detection accuracy and contribute to shortening the detection time.

[0005]

According to a first aspect of the present invention, there is provided a drum for storing laundry, a motor for directly rotating the drum, and a state in which a predetermined constant power is supplied to the motor during spinning. An unbalance detecting means for detecting the degree of fluctuation of the rotation speed during one rotation of the motor and detecting the unbalance rotation of the drum according to the degree of fluctuation.

According to the first aspect of the present invention, since the drum is directly driven by the motor, there is no slip between the drum and the motor, and the vibration of the drum is small. The balance situation is favorably reflected on the rotation speed situation of the motor.
In addition, in the first aspect of the present invention, the unbalance detection method itself is also changed, so that the unbalance detection accuracy is improved. In other words, when the laundry is unevenly attached to the inner peripheral surface of the drum, and a predetermined constant power is supplied to the motor, a certain rotation angle region and another rotation angle region are generated during one rotation of the drum. It was found that the rotation speed of the drum was different, that is, the rotation speed fluctuated, and the degree of the fluctuation was larger as the degree of uneven distribution of the laundry, that is, the degree of imbalance was larger.

According to the first aspect of the present invention, when the motor is supplied with a predetermined constant power during dehydration,
Since the unbalance detection means for detecting the degree of fluctuation of the rotation speed during rotation and detecting the unbalanced rotation of the drum according to the degree of fluctuation is provided, the accuracy of unbalance detection is improved, and the time required for detection is shortened. . In addition, since the motor and the drum always rotate synchronously, there is no problem even if the rotation speed of the motor is detected as the rotation speed of the drum.
It is possible to make the device more compact than when detecting a large drum rotation speed.

According to a second aspect of the present invention, there is provided a drum for storing laundry, a motor for directly rotating the drum, and a predetermined constant electric power supplied to the motor during spin-drying. Detecting the degree of fluctuation of the rotation speed during one rotation of the motor, on condition that the rotation state is reached,
An imbalance detecting means for detecting an imbalance rotation of the drum according to the degree of the fluctuation.

According to the second aspect of the invention, the accuracy of unbalance detection can be further improved. That is, as described above, it is possible to improve the unbalance detection accuracy by detecting the degree of change in the rotation speed during one rotation of the drum. Is very different from
It is feared that the imbalance will change afterwards due to the movement of the laundry inside, but in situations where the current one rotation situation and the next one rotation situation are hardly different, the imbalance situation at that time Is expected to continue.

According to the second aspect of the present invention, a predetermined constant power is supplied to the motor, and the degree of fluctuation of the rotation speed during one rotation of the motor is determined on condition that the motor is in the same rotation state a plurality of times. Since the detection is performed and the unbalance rotation of the drum is detected according to the degree of the fluctuation, the accuracy of the unbalance detection is further improved.

According to a third aspect of the present invention, there is provided a drum for storing laundry, a motor for directly rotating the drum, and feedback control for a predetermined time so that the motor has a rotational speed for unbalance detection during spin-drying. ,After this,
And an unbalance detecting means for supplying an average electric power at the time of the feedback control to the motor, detecting a degree of change in rotation speed during one rotation of the motor, and detecting an unbalanced rotation of the drum according to the degree of change. Be composed.

When the unbalance rotation of the drum is detected, it is premised that the laundry is stuck on the inner peripheral surface of the drum. It is preferable to rotate at an unbalance detection rotation speed. Then, the power to the motor is fixed and the unbalance is detected.
If the power is inappropriate, the rotational speed for unbalance detection will increase or decrease sequentially. According to the third aspect of the present invention, the control for keeping the rotation speed of the motor at the rotation speed for unbalance detection for a predetermined time by feedback control is performed, the power to the motor at this time is averaged, and the average power is kept constant. Since the electric power is used, the unbalance detection can be performed satisfactorily while keeping the drum at the rotational speed for the unbalance detection as a whole. By the way, feedback control means that when the rotation speed of the motor exceeds the rotation speed for unbalance detection, the power supply to the motor is reduced,
This is control for increasing the power supplied to the motor when the rotation speed falls below the unbalance detection rotation speed. In addition,
If the motor is driven by the last supply power during the feedback control, the motor rotation speed may increase or decrease. There is no.

According to a fourth aspect of the present invention, in any one of the first to third aspects of the present invention, the degree of rotation speed fluctuation is determined by determining an average rotation speed of one rotation of the motor and a rotation in a plurality of rotation angle regions during one rotation. It is characterized by being indicated by the integrated value of the difference from the speed. The magnitude of the fluctuation of the rotation speed is indicated by the difference between the average speed in one rotation and the rotation speed in a certain rotation angle region during one rotation. In this case, the rotation speed is detected in a plurality of rotation angle regions during one rotation, the difference between the plurality of rotation speeds and the average speed in one rotation is individually calculated, and the difference is integrated to obtain the rotation speed. Is more remarkably shown. As a result, the unbalance detection accuracy is further improved.

According to a fifth aspect of the present invention, in the invention of the fourth aspect, a difference between an average rotation speed of one rotation of the motor and rotation speeds in a plurality of rotation angle regions during the one rotation is defined as the average rotation speed. The feature is that the correction is made according to. When the rotation speed of the motor is generally high, the rotation speed in a plurality of rotation angle regions during one rotation is also high. Therefore, according to the fifth aspect of the present invention, the difference between the average rotation speed of one rotation of the motor and the rotation speed in a plurality of rotation angle regions during one rotation is corrected in accordance with the average rotation speed. Thus, the unbalance detection error can be reduced.

According to a sixth aspect of the present invention, in any one of the first to third aspects of the present invention, the rotation speed of the motor in one rotation in a predetermined rotation angle region and the rotation speed in the next rotation in the same predetermined rotation angle region. The difference is that when the difference is equal to or larger than a predetermined value, the detection of the unbalance rotation is performed again. If the overall rotational speed of the motor is increasing or decreasing, the imbalance situation may change. In such a situation, if unbalance detection is performed, an unbalance detection error may occur. . However, according to the invention of claim 6, when the difference between the rotation speed of the motor in the predetermined rotation angle region in one rotation and the rotation speed in the same rotation angle region in the next rotation is equal to or more than a predetermined value, When the overall rotation speed of the is slightly increasing or decreasing, the detection of the unbalance rotation is performed again, so that the unbalance detection accuracy is further improved.

A seventh aspect of the present invention is characterized in that in any one of the first to third aspects of the present invention, the unbalance detection is performed at at least two different unbalance detection rotational speeds lower than the maximum dehydration rotational speed. . The imbalance situation may also change depending on the rotation speed of the drum. For example, when the rotation speed is low, a part of the laundry may be located at the center of the drum and not in an unbalanced state. If the rotation speed of the drum is increased as it is, a large imbalance may occur when the rotation speed increases. However, in the invention of claim 7, since the unbalance detection is performed at at least two different rotation speeds for unbalance detection that is less than the maximum spinning rotation speed, the unbalance can be reliably detected.
It is possible to prevent the dehydration operation from being performed while the imbalance occurs.

According to an eighth aspect of the present invention, in the invention of the seventh aspect, the next unbalance detection rotation speed is determined according to the result of the unbalance detection at the first unbalance detection rotation speed. However, it has features. When the result of the unbalance detection is large, the unbalance correction processing for correcting the unbalance is performed. When the unbalance is medium or small, the unbalance correction processing is not performed. It is conceivable to start the rotation of the drum. In this case, as the degree of unbalance is smaller, the unbalance is less likely to occur, and even if it occurs, it occurs after the rotation speed of the drum is higher, and when the degree of unbalance is moderate, the started rotation speed is lower. It tends to occur sometimes due to a large imbalance. Therefore, according to the invention of claim 8, the next unbalance detection rotation speed is determined according to the result of the unbalance detection at the first unbalance detection rotation speed. Balance detection can be performed.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to FIGS. First, in FIG. 2, the outer box 1 of the drum type washing machine has a rectangular box shape as a whole, and a circular laundry entrance 2a is formed in a front plate portion 2 thereof. Inside the outer case 1, there are provided, for example, four sets (only two sets are shown) of suspensions 4 constituting a vibration damping mechanism.
, So that it is elastically supported.

The water tank 3 has a body 5, a rear plate 6, and a front plate 7, all of which are formed of a metal plate, and the front plate 7 has a circular shape. Opening 7a is formed. The opening 7a and the laundry entrance 2a are connected so as to be communicated with each other by a generally cylindrical connecting member 8 made of an elastic material, for example, rubber, which has a cylindrical shape as a whole. The laundry entrance 2a is opened and closed by a door 9.

A drum 10 is rotatably provided inside the water tank 3. The drum 10 includes, for example, a body 11 formed of a metal plate and a rear member 12.
And the front plate 13. The torso 1
A large number of holes 11a are formed in one peripheral wall portion, and a circular opening 13a is formed in the front plate portion 13. Further, the rear surface member 12 is configured by attaching a porous plate member 12b to a frame member 12a having a plurality of ventilation holes.

A drum shaft 14 is attached to the center of the rear member 12 of the drum 10 so as to protrude rearward. The drum shaft 14 is attached through the rear plate 6 of the water tank 13. The bearing housing 15 is rotatably supported via a bearing 16, so that the drum 10 is rotatably provided.

Further, the drum 10 is directly driven by a washing machine motor (motor) 17 which is an outer rotor type and is a brushless motor. That is,
A rotor magnet 18a is provided at the rear end of the drum shaft 14.
The bearing housing 15 is provided with a stator 19 having a stator core and a coil so as to be located inside the rotor 18. Therefore, when the rotor 18 is rotated, the drum 10 is directly driven to rotate via the drum shaft 14.

Further, a drain valve 20 is provided at the bottom of the water tank 3, and when the drain valve 20 is opened, water in the water tank 3 is drained to the outside. Note that FIG.
Although not shown, a water supply valve (indicated by reference numeral 21 in FIG. 3) for supplying water into the water tank 3 is provided.

Next, the electrical configuration will be described with reference to FIG.
That is, both terminals of the AC power supply 22 are connected to the DC power supply circuit 2 having a voltage doubler rectifier circuit and a smoothing capacitor.
3 are connected. DC buses 23a and 23b are derived from output terminals of the DC power supply circuit 23, and an inverter main circuit 24 is connected to the DC buses 23a and 23b. The inverter main circuit 24 includes three-phase bridge-connected switching elements 25a to 25f made of, for example, IGBTs, and these switching elements 25a
To 25f are connected in parallel with freewheel diodes 26a to 26f, respectively. And
The output terminals 27u, 27v of this inverter main circuit 24,
27w is a three-phase winding 17u of the washing machine motor 17, 17
v, 17w. The control terminals (gates) of the switching elements 25a to 25f of the inverter main circuit 24 are connected to a drive circuit 28 composed of, for example, a photocoupler. The drive circuit 28 is controlled by a control signal from the control circuit 29 to perform on / off control of each of the switching elements 25a to 25f.

The position detection signals Ha and Hb output from the Hall ICs 30a and 30b, which are the position detection elements of the washing machine motor 17, are provided to the control circuit 29. The above two Hall ICs 30a, 30b
Are arranged such that the position detection signals Ha and Hb change every 90 degrees in the electrical angle of the rotor phase as shown in FIG. The Hall IC 30a is driven to a high level (0 to 180 electrical degrees) in synchronization with the U-phase induced voltage.
Degree), the positional relationship with the rotor 18 is set so as to output a low-level signal. That is, the U-phase winding 17u
The position relationship is such that a position detection signal Ha changing to a high level is obtained at a position where the magnetic pole of the rotor magnet 18a and the magnetic pole of the rotor magnet 18a face each other.

The control circuit 29 includes a microcomputer, has a program for driving the washing machine motor 17 to rotate, and controls the position detection signal H.
a, Hb based on the switching element 25a described above.
２５25f are turned on / off and PWM controlled so that each winding 17
PWM control and energization timing control of the applied voltage to u, 17v, and 17w are performed.
7 is rotationally controlled. Note that the above P
The power supplied to the washing machine motor 17 is controlled by the WM control. Further, the rotation speed of the washing machine motor 17 is also detected based on the position detection signal. Further, a switch signal is supplied to the control circuit 29 from a switch input unit 31 provided on an operation panel (not shown).

The control circuit 29 functions as a rotation speed detecting means and also functions as a dehydrating control means and an unbalance detecting means at the time of dehydrating, which will be described. First, the function as the rotation speed detecting means will be described. As shown in FIG.
0a is a one pole pair of the rotor magnet 18a of the rotor 18, which generates a position detection signal Ha for one cycle.
Accordingly, twelve rising signals Hah are generated for one rotation of the washing machine motor 17. And the Hall IC 30b
Generates the rising signal Hbh 12 times with a delay of 90 electrical degrees from the position detection signal Ha. The control circuit 29 generates pulses at 2 μsec intervals from the rising signals Hah to Hbh and counts them.

That is, the electrical angle between the rising signals Hah and Hbh is 90 degrees, and one electrical angle (360 degrees)
The rotation speed of the washing machine motor 17 is 1/12 rotation. Therefore, every time the washing machine motor 17 rotates 1/12 rotation, the rotation speed in the 1/48 angle region E (n) is indicated by the count number T (n). In this case, n is one rotation of the washing machine motor 17
The rotation angle region is divided into two equal parts, which are 0 to 11 (12
Position) (see FIG. 5). Note that the above count T
The smaller (n), the lower the rotation speed. By the way, when the rotation speed of the washing machine motor 17 is 100 rpm in a state where there is no uneven rotation, the rising signal Hah changes to H
The time up to bh (elapsed time for 1/48 rotation) is 0.0125 seconds, which is expressed in units of 2 μsec (0.000
002 seconds), the count value T (n)
= 6250.

The functions of the dehydration control means and the imbalance detection means will be described with reference to FIG. In step Q1, the washing machine motor 17 is started, and the rotation speed of the washing machine motor 17 (this is the count value T
(Detected with (n)) is controlled so as to start up until 100 rpm. In this case, 4
The count value T (n) is read every 0 ms, and P is set so that predetermined power is sequentially supplied to the washing machine motor 17.
Perform WM control (change the on-duty ratio.
In this case, the position detection signal H is sequentially increased).
Based on a and Hb, the timing of energizing each phase winding 17u, 17v, 17w is determined and commutating.

Thereafter, in step Q2, the on-duty ratio of the PWM control is fixed at a constant value, and the washing machine motor 1
7 is fixed to a predetermined constant value and output (open control, not feedback control). Next, in step Q3, a count value T (n) which is a rotation speed of each rotation angle region E (n) in one rotation of the washing machine motor 17, that is, T0 to T11 is detected. FIG. 7 shows an example of the count value T (n). FIG. 7 also shows the rotational speed indicated by the count value and the absolute value Ta of the difference between an average value Tave and each count value T (n) described later.

In the next step Q4, the washing machine motor 17
Count value T corresponding to the average rotation speed of one rotation of
ave is calculated by the following equation. Tave = (T (0) + T (1) +... + T (11)) / 1
2

In step Q5, the absolute value Ta of the difference between the average value Tave and each count value T (n) is determined, and the absolute value S is integrated. At this time, the integrated value S is the washing machine motor 1
7 shows the degree of fluctuation of the rotation speed during one rotation, and is expressed by the following equation (1).

(Equation 1) In step Q6, the integrated value S is equal to a reference value for determining imbalance, for example, “768” (this is 30 in hexadecimal).
0H, which is replaced by a hexadecimal number in the processing of the microcomputer). If the integrated value S is equal to or greater than the reference value "768", it is determined that imbalance has occurred, and the process proceeds to step Q7 to perform an imbalance correction process. This imbalance correction process reduces the rotation speed of the washing machine motor 17 for a predetermined time. Thereafter, the process returns to step Q1.

If it is determined in step Q6 that the integrated value S is less than the reference value "768", that is, if it is determined that unbalance rotation has not occurred, the process proceeds to step Q8, in which the motor 17 of the washing machine motor 17 is controlled. Increase the rotation speed to the target rotation speed. Then, the flow proceeds to step Q9, and when it is determined that the set dehydration time has elapsed, the flow proceeds to step Q10, in which the rotation of the washing machine motor 17 is stopped, the dehydration operation is ended, and the flow proceeds to the next stroke control. .

According to the above-described embodiment, since the drum 10 is directly driven by the washing machine motor 17, there is no slip between the drum 10 and the washing machine motor 17 and the vibration of the drum 10 As a result, the unbalanced state of the drum 10 is
Satisfactorily reflected on the rotational speed condition of the motor. Moreover,
In this embodiment, the unbalance detection method itself is different from the conventional method, so that the unbalance detection accuracy can be improved.

That is, when laundry is unevenly attached to the inner peripheral surface of the drum 10 and a predetermined constant electric power is supplied to the washing machine motor 17, a certain rotation angle is obtained during one rotation of the drum 10. It has been found that the rotation speed of the drum is different between the region and the other rotation angle region, that is, the rotation speed is fluctuated.

In the present embodiment focusing on this point, the integrated value S, which is the degree of fluctuation of the rotation speed during one rotation of the washing machine motor 17 in a state where a predetermined constant power is supplied to the washing machine motor 17 during spin-drying, is calculated. Since the detection is performed and the unbalance rotation of the drum 10 is detected according to the integrated value S, the accuracy of the unbalance detection can be improved, and the time required for the detection can be shortened. In addition, since the washing machine motor 17 and the drum 10 always rotate in synchronization, there is no problem even if the rotation speed of the washing machine motor 17 is detected as the rotation speed of the drum 10. The configuration can be made more compact as compared with the case where the rotation speed of the large drum 10 is detected.

In this case, according to the present embodiment, the Hall IC 30a, which is a position detecting means provided in the washing machine motor 10,
Since 30b is used as a part of the rotation speed detecting means,
As a result, it is possible to further reduce the size and cost.

In particular, according to the present embodiment, as described above, the rotation speed fluctuation degree is determined by the average rotation speed Tave of one rotation of the washing machine motor 17 and the plurality of rotation angle regions E (n) during one rotation. ), The degree of change in the rotational speed becomes more prominent, and as a result, the unbalance detection accuracy is further improved.

FIGS. 8 to 10 show a second embodiment of the present invention, which differs from the first embodiment in the following points. That is, step R1, step R
2 correspond to steps Q1 and Q in FIG. 1 of the first embodiment.
The control is the same as step 2, and the control from the next step R3 to step R7 is characteristic. That is, after the power supplied to the washing machine motor 17 is fixed to a predetermined value in step R2, in step R3, the washing machine motor 17
Rotation speed T in the region E (0) of one rotation of
(0) (in this case, T01, see FIG. 9), and
In the next step R4, the rotation speed T (0) (T02 in this case) in the same area E (0) in the next one rotation is detected.

In step R5, it is determined whether or not the absolute value of the difference between the first rotation speed T01 and the second rotation speed T02 is equal to or less than a predetermined fluctuation range "40" (pulse count value). If not, the process proceeds to step R6 to detect the rotation speed T (0) of the same area E (0) (T03 in this case) in the next one rotation. The second rotation speed T02 and the third rotation speed T
It is determined whether or not the absolute value of the difference from 03 is equal to or smaller than a predetermined fluctuation range “40” (pulse count value).
That is, if the fluctuation of the rotation speed in the same region E (0) is twice or less continuously “40” or less, the fluctuation detection and the unbalance detection in step R8 and thereafter (step Q8 in the first embodiment) are performed.
3 to step Q10). If "NO" is determined in the steps R5 and R7, the process returns to the step R3.

In the second embodiment, the unbalance detection accuracy can be further improved. That is,
As described above, it is possible to improve the unbalance detection accuracy by detecting the degree of change (integrated value S) of the rotation speed during one rotation of the washing machine drum 17,
In a situation in which the current one rotation situation is greatly different from the next one rotation situation, there is a concern that the laundry may move inside and the imbalance situation may change thereafter. However, it is expected that the imbalance state at that time will continue in a situation where the current one rotation situation and the next one rotation situation are hardly different. FIG. 10 shows a state in which the rotation state is stabilized after supplying a constant power to the washing machine motor 17. In this case, the rotation status is stabilized at the time Tk, and the process proceeds to step R8.

According to the second embodiment, however, a predetermined constant power is supplied to the washing machine motor 17, and the washing machine motor 17 is rotated almost twice (rotation speed is detected three times).
Under such a condition, the degree of change (integrated value S) of the rotation speed during one rotation of the motor is detected, and the unbalance rotation of the drum 10 is detected according to the degree of change. The detection accuracy is further improved. The detection of the rotation status is not limited to the area E (0), and may be any of the other areas E (1) to E (11). The number of times of detection of the rotation status is not limited to two, but may be three or more.

FIGS. 11 and 12 show a third embodiment of the present invention, which differs from the first embodiment in the following points. That is, in step S2,
Unbalance detection rotational speed In this case, feedback control is performed for a predetermined time, for example, approximately 8 seconds so as to keep 100 rpm. FIG. 12 shows the contents of this feedback control as a subroutine. In step W1 of FIG. 12, one of the rotation speeds of the area E (n) is detected every 40 ms. In step W2, it is determined whether or not the rotation speed is 100 rpm or more. If it is, the process proceeds to step W3 to appropriately reduce the on-duty ratio of the PWM control to reduce the supply power. Then, the power supply is increased by appropriately increasing the on-duty ratio of the PWM control.

In the next step W5, the duty ratio is integrated. Thereafter, the process shifts to step W6 to judge whether or not the control up to this time has reached 20 times, and if less than 20 times, returns to step W1. In this way, when the number of times reaches 20 times (approximately 8 seconds have elapsed), the process shifts to step W7, and the average duty ratio is calculated by dividing the duty ratio integrated in step W4 by 20 times to calculate the average supply power. calculate. Thereafter, the process shifts to step S3 of FIG. 11 to supply the average supply power to the washing machine motor 17. Then, similarly to Steps Q3 to Q10 of the first embodiment, detection of the degree of fluctuation and detection of imbalance are performed.

The third embodiment focuses on the following points. That is, when the unbalance rotation of the drum 10 is detected, it is assumed that the laundry is stuck on the inner peripheral surface of the drum 10. Therefore, before the detection of the unbalance rotation, the drum 10 is rotated in consideration of the rotation. Speed, that is, rotational speed for unbalance detection (for example, 100 rpm
Preferably, it is rotated in m). Then, the power to the washing machine motor 17 is fixed to perform the unbalance detection. If the power is inappropriate, the rotational speed for the unbalance detection increases or decreases sequentially.

According to the third embodiment, however, the control for keeping the rotation speed of the washing machine motor 17 at the rotation speed for unbalance detection for a predetermined time by the feedback control is performed. Since the power is averaged and the average power is set to a constant power, unbalance detection can be performed satisfactorily while keeping the drum 10 at the rotational speed for unbalance detection as a whole.

FIGS. 13 and 14 show a fourth embodiment of the present invention. This embodiment differs from the first embodiment in the following points. That is, in step U5 of FIG. 13, the average rotation speed Tave (pulse count value) obtained in step U4
And a difference Ta (see FIG. 14) between the count value and each count value T (n). In step U6, the current average rotational speed T
The difference Ta obtained in step U5 is corrected in accordance with the ratio between av and the total pulse count value “6250” corresponding to 100 rpm, which is the unbalance detection rotation speed (correction value T
a ').

6250: Tave = Ta ': Ta Ta' = 6250.Ta / Tave Then, in step U7, the corrected difference Ta 'is integrated to obtain an integrated value S'. Thereafter, the process shifts to step U8 to add the integrated value S 'to the reference value "76" for the unbalance determination.
8 "to determine the presence or absence of unbalance rotation.

The fourth embodiment focuses on the following points. That is, when the rotation speed of the washing machine motor 17 is generally high, the rotation speed in a plurality of rotation angle regions during one rotation is also high. Here, the reference value (“768” in this case) of the unbalance determination is such that when the drum 10 rotates on average at the unbalance detection rotation speed (100 rpm in this case), the unbalance is appropriately determined based on the integrated value S. It is determined so that it can be determined (determined experimentally), and even if the degree of imbalance is the same, if the average rotation speed of the drum 10 is different, the integrated value S is also different. However, according to the fourth embodiment, the difference Ta between the average rotation speed Tave of one rotation of the washing machine motor 17 and the rotation speeds T (n) in a plurality of rotation angle regions during this one rotation is determined by imbalance. The detected rotation speed “100 rpm” and the actual average rotation speed t
By correcting according to the ratio to ave, the unbalance detection error can be reduced.

FIG. 15 shows a fifth embodiment of the present invention. This embodiment has the following features. That is, as can be seen from steps V3 to V5, the rotation speed T0 in one rotation of the washing machine motor 17 in the predetermined rotation angle region and the same rotation angle region T01 in the next rotation are used.
The difference from the rotation speed at is a predetermined value as an absolute value. In this case, "40"
In the above case, step V3 is redone, that is, the unbalance rotation detection is redone.

The fifth embodiment focuses on the following points. That is, when the overall rotation speed of the washing machine motor 17 is increasing or decreasing, it is conceivable that the unbalance situation changes. In such a situation, when the unbalance detection is performed, the unbalance detection error occurs. May be caused. However, according to this embodiment,
If the difference between the rotation speed T01 in one rotation of the washing machine motor 17 in the predetermined rotation angle region and the rotation speed t11 in the next rotation in the same predetermined rotation angle region is equal to or greater than the absolute value of the predetermined value "40", Thus, it can be determined that the overall rotation speed of the motor is rising or falling, and at this time, the detection of the unbalance rotation is performed again, so that the unbalance detection accuracy is further improved.

FIGS. 16 to 18 show a sixth embodiment of the present invention. In the sixth embodiment, the following points are set forth in the first embodiment.
Is different from the embodiment. That is, a plurality of rotational speeds for detecting imbalance are provided below the final target rotational speed (maximum dehydration rotational speed). The first is at 100 rpm and the second is at 500 or 600 rpm.
Furthermore, when unbalance is detected,
The determination is made as any of small unbalance (including no unbalance), medium unbalance, and large unbalance.

Now, in step X3, control for detecting the degree of fluctuation is performed. This control is shown as a subroutine in FIG. 17, which is the same as steps Q3 to Q5 in the flowchart of the first embodiment. When the integrated value S is calculated in the subroutine of FIG. 17 (step Y3), the process proceeds to step X4 of FIG. In Steps X4 and X5, it is determined from the integrated value S whether the imbalance is small (including no imbalance), during imbalance, or large.
That is, as can be seen from FIG. 18, the small imbalance in step X4 is determined based on the fact that the integrated value S is less than “512” (200H in hexadecimal), and during the unbalance in step X5, the integrated value S is small. Is "512" or more and "76"
8 "(300H in hexadecimal), and the large imbalance is determined by the fact that the integrated value S is" 768 "or more.

If the imbalance is small, the process proceeds to step X7, and the rotation speed of the washing machine motor 17 is increased to the next rotation speed for detecting imbalance, "600 rpm". If unbalanced, step X8
Then, the rotation speed of the washing machine motor 17 is increased to "500 rpm" which is the next rotation speed for unbalance detection. That is, the rotational speed for unbalance detection is determined according to the result of unbalance detection. When the unbalance is large, the unbalance correction processing (step X6) is performed, and the process returns to step X1.

After step X7 or step X8, the process proceeds to step X9 to supply a constant electric power to the washing machine motor 17 (this differs depending on the preceding stage at 500 rpm and 600 rpm). Thereafter, in step X10 (subroutine steps Y1 to Y3), the integrated value S is calculated, and the imbalance state is determined again (step X1).
1 or step X12). Here, when the imbalance is small, the washing machine motor 17 is raised to the final target rotation speed (step X14), and the process proceeds to step X15 and step X16. If the balance is being imbalanced, the rotation speed is kept as it is (600 rpm), and the process proceeds to step X15 and step X16. When the imbalance is large, the imbalance correction processing (step X13)
And returns to step X1.

The sixth embodiment focuses on the following points. That is, the unbalanced state is determined by the drum 10
It may also change depending on the rotation speed of. For example, when the rotation speed is low, a portion of the laundry may be located at the center of the drum 10 and may not be in an unbalanced state. If the rotation speed of the drum 10 is increased as it is, a large imbalance may occur when the rotation speed increases. However, according to this embodiment, the unbalance detection is performed at a different rotation speed for unbalance detection below the final target rotation speed, so that the unbalance can be reliably detected, and the unbalance occurrence state can be maintained. It is possible to prevent the dehydration operation from being performed.

In particular, in the sixth embodiment, the next unbalance detection rotation speed is determined according to the result of the unbalance detection at the first unbalance detection rotation speed (step X4 or step X5) (step X7). Alternatively, since the step X8) is performed, the following effects can be obtained. That is, if the result of the unbalance detection is large, the unbalance correction processing for correcting the unbalance is performed. However, if the unbalance is medium or small, the unbalance correction operation is not performed. Next, it is conceivable to start the rotation of the drum.
In this case, as the degree of unbalance is smaller, the unbalance is less likely to occur, and even if it occurs, it occurs after the rotation speed of the drum is higher, and when the degree of unbalance is moderate, the started rotation speed is lower. It tends to occur sometimes due to a large imbalance. However, in the sixth embodiment, as described above, the next unbalance detection rotation speed is determined according to the unbalance detection result at the first unbalance detection rotation speed. Unbalance detection can be performed at an appropriate time.

The rotational speeds for detecting the unbalance are 100 rpm, 500 rpm, and 600 rpm, respectively.
The number of times of unbalance detection is not limited to two as shown in this embodiment, and may be three or more.

[0059]

As apparent from the above description, the present invention has the following effects.

According to the first aspect of the present invention, since the drum is directly driven by the motor, there is no slip between the drum and the motor, and the vibration of the drum is small. The balance state can be properly reflected on the rotation speed state of the motor, and the degree of rotation speed fluctuation during one rotation of the motor is detected while a predetermined constant power is supplied to the motor during dehydration. The imbalance detection means that detects the unbalance rotation of the drum is provided accordingly, improving the unbalance detection accuracy and shortening the time required for detection.
Further, it is possible to make the rotation speed detection configuration more compact than when detecting the rotation speed of a large drum.

According to the second aspect of the present invention, a predetermined constant power is supplied to the motor, and the degree of fluctuation of the rotation speed during one rotation of the motor is determined on the condition that the motor is in the same rotation state a plurality of times. Since the detection is performed and the unbalance rotation of the drum is detected according to the degree of the fluctuation, the accuracy of the unbalance detection can be further improved.

According to the third aspect of the present invention, the control for keeping the rotation speed of the motor at the rotation speed for unbalance detection for a predetermined time by feedback control is performed, and the power to the motor at this time is averaged. Since the power is kept constant, unbalance detection can be performed satisfactorily while keeping the drum at the rotational speed for unbalance detection as a whole. According to the invention of claim 4, the degree of rotation speed fluctuation is indicated by an integrated value of a difference between an average rotation speed of one rotation of the motor and rotation speeds in a plurality of rotation angle regions during one rotation. And the unbalance detection accuracy is further improved.

According to the fifth aspect of the present invention, the difference between the average rotation speed of one rotation of the motor and the rotation speed in a plurality of rotation angle regions during one rotation is corrected according to the average rotation speed. Therefore, the unbalance detection error can be reduced. According to the invention of claim 6, when the difference between the rotation speed in one rotation angle region of the motor in the predetermined rotation angle region and the rotation speed in the next predetermined rotation angle region in the next rotation is equal to or greater than the predetermined value, the unbalanced rotation Is detected again, so that when the overall rotation speed of the motor is increasing or decreasing, the unbalanced rotation can be detected again, and the unbalance detection accuracy is further improved.

According to the seventh aspect of the present invention, the unbalance detection is performed at at least two different rotational speeds for detecting imbalance, which are lower than the maximum spinning rotational speed.
It is possible to reliably detect the imbalance and prevent the dehydration operation from being performed while the imbalance is occurring. According to the eighth aspect of the present invention, the next unbalance detection rotation speed is determined according to the result of the unbalance detection at the first unbalance detection rotation speed. Can be performed.

[Brief description of the drawings]

FIG. 1 is a flowchart of dehydration control contents showing a first embodiment of the present invention.

FIG. 2 is a longitudinal sectional side view of a drum type washing machine.

FIG. 3 is a block diagram of an electrical configuration.

FIG. 4 is a diagram showing a relationship between an induced voltage and a position detection signal.

FIG. 5 is a diagram showing a rotation angle region for detecting a rotation speed;

FIG. 6 is a diagram showing a state of fluctuation of a rotation speed of a drum.

FIG. 7 is a diagram showing a relationship between a count value, a difference, and a rotation speed.

FIG. 8 is a flowchart of dehydration control contents showing a second embodiment of the present invention.

FIG. 9 is a diagram corresponding to FIG. 6;

FIG. 10 is a diagram showing a state of a change in rotation speed.

FIG. 11 is a flowchart of dehydration control contents showing a third embodiment of the present invention.

FIG. 12 is a flowchart of 100 rpm keep control.

FIG. 13 is a flowchart of dehydration control contents showing a fourth embodiment of the present invention.

FIG. 14 is a diagram showing a relationship between a count value, a difference, and a correction value.

FIG. 15 is a flowchart of dehydration control contents showing a fifth embodiment of the present invention.

FIG. 16 is a flowchart of dehydration control contents showing a sixth embodiment of the present invention.

FIG. 17 is a flowchart of fluctuation degree detection control.

FIG. 18 is a diagram illustrating a relationship between a threshold value of unbalance detection and a detection result;

[Explanation of symbols]

Reference numeral 3 denotes a water tank, 10 denotes a drum, 17 denotes a washing machine motor (motor), 24 denotes an inverter main circuit, 30a and 30b denote position detecting elements, and 29 denotes a control circuit (unbalance detecting means).

Claims (8)

[Claims] 1. A drum for storing laundry, a motor for directly rotating the drum, and a degree of fluctuation of a rotation speed during one rotation of the motor while a predetermined constant power is supplied to the motor during dehydration. A drum-type washing machine comprising: an unbalance detecting unit that detects the unbalance rotation of the drum according to the degree of the fluctuation. 2. A drum for accommodating laundry, a motor for directly rotating the drum, and a predetermined constant electric power supplied to the motor during spin-drying, so that the motor is substantially in the same rotational state a plurality of times. A drum type washing machine comprising: an unbalance detection unit that detects a degree of change in rotation speed during one rotation of the motor and detects an unbalanced rotation of the drum in accordance with the degree of change. 3. A drum for storing laundry, a motor for directly rotating the drum, and a feedback control for a predetermined time so that the motor has a rotational speed for unbalance detection during spin-drying. And an unbalance detecting means for supplying an average electric power at the time of feedback control to the motor, detecting a degree of change in rotation speed during one rotation of the motor, and detecting an unbalanced rotation of the drum according to the degree of change. Drum type washing machine. 4. The rotation speed fluctuation degree is indicated by an integrated value of a difference between an average rotation speed of one rotation of the motor and rotation speeds in a plurality of rotation angle regions during one rotation. 4. The drum type washing machine according to any one of 1 to 3. 5. The average rotation speed of one rotation of the motor and the average rotation speed
5. The drum type washing machine according to claim 4, wherein a difference between the rotation speeds in a plurality of rotation angle ranges during rotation is corrected according to the average rotation speed. 6. When the difference between the rotation speed of one rotation of the motor in a predetermined rotation angle region and the rotation speed of the next rotation in the predetermined rotation angle region is equal to or larger than a predetermined value, detection of unbalanced rotation is performed again. The drum type washing machine according to any one of claims 1 to 3, wherein the drum type washing machine is configured as described above. 7. The drum type washing machine according to claim 1, wherein the unbalance detection is performed at at least two different rotation speeds for detecting imbalance, which are lower than the maximum spinning rotation speed. 8. The drum-type drum according to claim 7, wherein the next unbalance detection rotation speed is determined according to the result of the unbalance detection at the first unbalance detection rotation speed. Washing machine.