JP2005204968A - Drum type washing machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a drum type washing machine that can optimally reduce an imbalanced state of laundries at the time of spin-drying in accordance with the actual usage. <P>SOLUTION: This drum type washing machine is made of a controlling microcomputer that calculates a variation value H indicating the fluctuation level of the rotating of a motor generated when the spin-drying operation is started, based on a q shaft current provided by the vector control (Steps S3, S4), and when it determines that the variation value H indicates approximately the minimum amount (Step S7, "YES"), it increases the rotating speed of the motor by maximum torque (Step S8). <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a drum-type washing machine having a configuration in which a rotating shaft of a rotating tub for storing laundry is arranged so as to be oriented substantially in the horizontal direction.

In the drum type washing machine, as shown in FIG. 16, in the drum D rotating at the angular velocity ω, the laundry positioned at the distance Ri from the center of rotation has the gravity g and the centrifugal force corresponding to the angular velocity ω and the distance Ri. F acts. As shown in FIG. 17A, when the laundry C is stuck to the inner peripheral wall of the drum D in an unbalanced state due to the distribution of other laundry (unbalanced state), Riω ² > When the rotational speed is gradually decreased from the state of g, the direction of the inequality sign is reversed earlier than other laundry because the distance from the center is short, and at that point the laundry C is peeled off from the inner peripheral wall and dropped. By doing so, the imbalance is resolved (see FIG. 17B).

Conventionally, when performing a dehydration operation in a drum-type washing machine, there is one that performs a balance adjustment operation in order to prevent the laundry in the drum from being dehydrated and rotated in an unbalanced state. For example, in Patent Document 1, when an acceleration sensor is arranged above the outside of the water tank containing the drum to detect the vibration state of the water tank, and the state where the vibration level is below a threshold value continues for a predetermined period of time. A technique is disclosed in which it is judged that the laundry distribution balance in the drum is in a good state (that is, the unbalance is minimized), and the number of revolutions of the drum is increased to perform the dehydration operation.
Japanese Patent No. 3442576

  However, in consideration of actual use conditions, the minimum unbalance amount that can be realized should be different in the amount of laundry and the quality of each laundry. Therefore, in the case where a method for determining a state in which the vibration level is equal to or lower than the threshold value as in the technique disclosed in Patent Document 1, in addition to such variation in use state, the assembly process of the washing machine In consideration of the unbalance that occurs in, the threshold value must be set higher. As a result, there has been a problem that dehydration operation cannot be performed in a state in which the imbalance is sufficiently eliminated.

  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 optimally eliminate the laundry unbalanced state during the dehydration operation according to the actual use state. There is.

The drum type washing machine of the present invention is arranged so that the rotation axis is oriented substantially in the horizontal direction, and a rotating tub for storing laundry,
A motor for rotating the rotating tank;
Control means for controlling the driving of the motor;
Fluctuation value output means for calculating and outputting a fluctuation value indicating a rotation fluctuation level of the motor generated when dehydration operation is started,
When the control means determines that the variation value is substantially the minimum, the control means increases the rotational speed of the motor by an acceleration larger than the previous acceleration.

  That is, the level of rotation fluctuation of the motor that occurs when the dehydrating operation is started reflects the unbalanced state of the laundry distribution accommodated in the rotating tub. Therefore, a large rotation fluctuation level indicates that the laundry is unevenly distributed inside the rotating tub and the unbalanced state is large. If the rotational fluctuation value shows a substantially minimum value, it can be estimated that the unbalanced state has been eliminated as much as possible, so that the rotational speed of the motor is increased at a higher acceleration than the previous acceleration from that point. For example, the state in which the distribution of the laundry is balanced, that is, the state in which the laundry is substantially uniformly attached to the inner peripheral wall surface of the rotating tub is fixed, and the dehydration operation is performed.

  According to the drum type washing machine of the present invention, it is possible to eliminate the imbalance of the laundry distribution accommodated in the rotary tub according to the actual operation state, so that noise and vibration are not generated during the dehydration operation. Further suppression is possible.

(First embodiment)
Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. First, in FIG. 10 showing the entire configuration of the drum type washing machine, a door 2 is provided at the center of the front side of the outer box 1 forming the outer shell of the drum type washing machine, and a number of switches and displays are provided at the top. An operation panel 3 having a unit (none of which is shown) is provided. The door 2 opens and closes a laundry entry / exit 4 formed in the center of the front portion of the outer box 1.

  A cylindrical water tank 5 is disposed inside the outer box 1. The water tank 5 is disposed in a horizontal axis shape in which the axial direction is the front-rear direction (the left-right direction in FIG. 10) and in an upwardly inclined shape, and is elastically supported by the elastic support device 6. Inside the water tank 5, a cylindrical drum (rotary tank) 7 is disposed coaxially with the water tank 5. The drum 7 functions as a common tank for dehydration and drying in addition to washing, and has a large number of small holes 8 (only part of which is shown in FIG. 10) formed in almost the entire region of the body. The part is provided with a plurality of baffles 9 (only one is shown in FIG. 10).

The aquarium 5 and the drum 7 have openings 10 and 11 for putting in and out the laundry on the front part, respectively. 7 opening 11 faces the opening 10 of the water tank 5. A balance ring 13 is provided around the opening 11 of the drum 7.
A motor 14 that rotationally drives the drum 7 is disposed on the back surface of the water tank 5. The motor 14 is an outer rotor type DC brushless motor, and a stator 15 is attached to an outer peripheral portion of a bearing housing 16 attached to a central portion of the back portion of the water tank 5. The rotor 17 is disposed so as to cover the stator 15 from the outside, and a rotating shaft 18 attached to the center is rotatably supported by the bearing housing 16 via a bearing 19. The front end portion of the rotating shaft 18 protruding from the bearing housing 16 is connected to the central portion of the back portion of the drum 7. That is, when the rotor 17 of the motor 14 is rotated, the drum 7 is also rotated integrally with the rotor 17.

A water reservoir 20 is provided on the lower surface of the water tank 5, and a heater 21 for washing water heating is disposed inside the water reservoir 20, and a drain hose is connected to the rear of the water reservoir 20 via a drain valve 22. 23 is connected.
A hot air generator 24 is provided at the top of the water tank 5, and a heat exchanger 25 is provided at the back. The hot air generating device 24 includes a hot air heater 27 disposed in a case 26, a fan 29 disposed in a casing 28, and a fan motor 31 that rotationally drives the fan 29 via a belt transmission mechanism 30. The case 26 and the casing 28 are communicated with each other. A duct 32 is connected to the front portion of the case 26, and the front end portion of the duct 32 protrudes to the front portion in the water tank 5 and faces the opening 12 of the drum 7.

  Here, warm air is generated by the warm air heater 27 and the fan 29, and the warm air is supplied into the drum 7 through the duct 32. The warm air supplied into the drum 7 heats the laundry in the drum 7 and removes moisture, and is discharged to the heat exchanger 25 side. The heat exchanger 25 has an upper part communicating with the inside of the casing 28 and a lower part communicating with the inside of the water tank 5, and water is poured from the upper part and flows down, thereby cooling water vapor in the air passing through the inside. It is a water-cooled type that condenses and dehumidifies. The air that has passed through the heat exchanger 25 is returned again to the hot air generator 24, where it is warmed and circulated.

  FIG. 9 is a functional block diagram showing the configuration of the control system of the drum type washing machine. This configuration is the same as that described in, for example, Japanese Patent Application No. 2002-212788, and will be described briefly below. The target speed command ωref is output from the control microcomputer 54 that controls the overall operation of the washing machine 11, and the subtractor 33 rotates the motor 14 detected by the target speed command ωref and the estimator 34. The result of subtraction from the speed ω is output.

  The speed PI control unit 35 performs PI control based on the difference between the target speed command ωref and the detected speed ω, and generates a q-axis current command value Iqref and a d-axis current command value Idref. The subtractors 36 and 37 output the subtraction result between the command values Iqref and Idref and the q-axis current value Iq and d-axis current value Id output from the αβ / dq converter 38 to the current PI controllers 39q and 39d. . The q-axis current value Iq is also given to the microcomputer 54.

  The current PI control units 39q and 39d perform PI control based on the difference between the q-axis current command value Iqref and the d-axis current command value Idref, and generate the q-axis voltage command value Vq and the d-axis voltage command value Vd. Output. The dq / αβ conversion unit 40 converts the voltage command values Vd and Vq into voltage command values Vα and Vβ based on the rotational phase angle (rotor position angle) θ of the secondary magnetic flux in the motor 14 detected by the estimator 34. To do.

The αβ / UVW conversion unit 41 converts the voltage command values Vα and Vβ into three-phase voltage command values Vu, Vv, and Vw and outputs them. The changeover switches 42u, 42v, 42w switch between the voltage command values Vu, Vv, Vw and the voltage command values Vus, Vvs, Vws for starting output from the initial pattern output unit 43 and output them.
The PWM forming unit 44 converts each phase PWM signal Vup (+, −), Vvp (+, −), Vwp (+, −) obtained by modulating a carrier wave of 16 kHz based on the voltage command values Vus, Vvs, Vws into the inverter circuit 45. Output to. The inverter circuit 45 is configured by connecting six IGBTs 46 in a three-phase bridge, and the emitters of the lower arm side U and V phase IGBTs 46 are connected to the ground via current detection shunt resistors 47 (u, v), respectively. Has been. The common connection point between the two is connected to the A / D converter 49 via an amplification / bias circuit (not shown). The inverter circuit 45 is applied with a DC voltage of about 280V obtained by double voltage full-wave rectification of a 100V AC power supply. The amplifier / bias circuit amplifies the terminal voltage of the shunt resistor 47 and applies a bias so that the output range of the amplified signal is within the positive side.

The A / D converter 49 outputs current data Iu and Iv obtained by A / D converting the output signal of the amplifier / bias circuit. The UVW / αβ converter 52 estimates W-phase current data Iw from the current data Iu, Iv, and converts the three-phase current data Iu, Iv, Iw into biaxial current data Iα, Iβ in an orthogonal coordinate system.
The αβ / dq converter 38 obtains the rotor position angle θ of the motor 14 from the estimator 34 during vector control and converts the biaxial current data Iα, Iβ into the d-axis current value Id, the q-axis current value Iq. Output every second. The estimator 34 estimates the position angle θ and the rotational speed ω of the rotor 17 based on the voltage command values Vd and Vq, the d-axis current value Id, and the q-axis current value Iq, and outputs them to each unit. In the above configuration, the configuration excluding the inverter circuit 45 is a function mainly realized by software of a DSP (Digital Signal Processor) 53.

  Next, the operation of the present embodiment will be described with reference to FIGS. FIG. 1 is a flowchart mainly showing an unbalance elimination determination process performed at the start of the dehydration operation, and is executed by the control microcomputer (control means, fluctuation value output means) 54. When the pre-process (step S1) such as “washing” and “rinsing” is performed, the control microcomputer 54 gradually increases the rotation speed of the motor 14 from zero, or increases the rotation speed once and then gradually decreases it. Then, unbalance correction is performed within the range of the rotational speed of 40 rpm to 80 rpm (step S2).

  Here, the upper limit of 80 rpm of the rotational speed range is a speed at which the laundry starts to stick to the uppermost point of the inner peripheral surface of the drum 7 by the action of centrifugal force in the process of the rotational speed gradually increasing. Further, the lower limit of 40 rpm of the rotation speed range is a rotation speed that is estimated to start the laundry from dropping from the uppermost point of the inner peripheral surface of the drum 7 in the process in which the rotation speed gradually decreases. That is, the range of the rotational speed corresponds to the vicinity of the rotational speed in which gravity and centrifugal force acting on the laundry in the drum 7 are balanced.

This unbalance correction operation is performed by vector control of the motor 14. In the rotation control, the output of the q-axis current value by the αβ / dq conversion unit 38 is performed at intervals of 128 μsec. Therefore, the rotation speed is controlled every 128 μsec in one rotation of the drum 7. Thereby, control is performed so that the rotation fluctuation during one rotation of the drum 7 is reduced.
That is, when the drum 7 is rotated at a relatively low speed in the drum type washing machine, the position of the laundry is easily changed because the laundry falls downward from the inner peripheral surface of the drum due to the action of gravity. Therefore, the laundry distribution balance can be adjusted to some extent by simply rotating the drum 7 at a relatively low speed. The details of the operation are described in, for example, Japanese Patent Application No. 2002-212788. Subsequently, the control microcomputer 54 reads the q-axis current Iq every 128 μs (step S3). In the next step S4, the q-axis current fluctuation value H is detected (step S4).

  Here, the detection process of the q-axis current fluctuation value H in step S4 will be described with reference to FIG. First, the detected q-axis current value is low-pass filtered by digital calculation to cut high-frequency components, and the number of detections is thinned at a predetermined thinning rate (step S21). Next, when the variation is extracted by high-pass filtering (step S22), the result is squared (step S23), and the high-frequency component of the squared result is removed by low-pass filtering (step S24). Then, since data as shown in FIG. 5B is obtained, this is set as a fluctuation value H of the q-axis current. The data of the fluctuation value H is written and stored in a memory inside the control microcomputer 54.

  Reference is again made to FIG. In step S5, it is determined whether or not the fluctuation value H is smaller than a predetermined threshold value Hk. That is, the fluctuation value H of the q-axis current reflects the load torque fluctuation of the motor 14. Therefore, a large fluctuation value H indicates that the rotation fluctuation of the drum 7 is large, and the unbalanced state of the laundry distribution in the drum 7 is large. In step S5, if the fluctuation value H is equal to or greater than the threshold value (determination value) Hk ("NO"), the process returns to step S2.

  As described above, when the fluctuation value H falls below the threshold value Hk while going through the loop of steps S2 to S5 (step S5, "YES"), the control microcomputer 54 determines the slope of the fluctuation value H ( (Time change rate) K is calculated (step S6). Since the calculation for obtaining the slope K here is performed every time the fluctuation value H is calculated, it is substantially performed by subtracting the previous value H (n−1) from the current value H (n). Is called.

  In subsequent step S7, the control microcomputer 54 determines whether or not the slope K is smaller than a predetermined value Δk near zero and the sign of the slope K is negative. If these two conditions are not satisfied simultaneously ("NO"), the process returns to step S2. If these two conditions are both satisfied (“YES”), the control microcomputer 54 rapidly accelerates the motor 14 with the maximum torque, and the drum 7 is set to the maximum rotational speed (for example, 900 rpm) during the dehydrating operation. Increase (step S8). After that, as in the general dehydration operation, the maximum rotation speed is maintained for a predetermined time and the dehydration operation is continued. When the predetermined time elapses, the motor rotation speed is reduced and the drum 7 is rotated. Stop.

  Here, FIG. 3 shows a change pattern of the rotational speed when the unbalance correction rotation in step S2 is performed gradually, and FIG. 4 shows a change pattern of the rotational speed when the correction rotation is performed gradually. Indicates. In addition, what is indicated by a broken line in these patterns is determined to be an unbalance correction failure when the rotation speed range exceeds the upper limit of 80 rpm or falls below the lower limit of 40 rpm while continuing the operation of step S2 in each figure. In this case, the rotation of the drum 7 is temporarily stopped (then, unbalance correction is performed again). Note that this processing portion is not reflected in FIG.

  In the process shown in FIG. 1, the reason for making the determination as in steps S5 to S7 will be described with reference to FIGS. FIG. 5 is an example in the case of performing balance control in the dehydration process. (A) drum vibration displacement, (b) change in fluctuation value H based on the vibration displacement, and (c) drum rotation speed. It shows a change. Note that the timing at which the number of revolutions of the drum is rapidly increased does not necessarily indicate the result of the present embodiment.

The fluctuation value H draws a gentle curve according to the vibration displacement of the drum, and the fluctuation value H also decreases as the vibration displacement decreases. Accordingly, the unbalance of the laundry distribution in the drum should be minimized when the variation value H is minimized. Therefore, in this embodiment, as shown in FIG. 6, when the fluctuation value H becomes smaller than a predetermined threshold value (step S5, “YES”), and the fluctuation value H decreases in that state. The point of time when the increase is about to be increased is grasped by the fact that the value T of the negative slope K first becomes smaller than Δk (step S7, “YES”), and the fluctuation value H shows a substantially minimum value. I am trying to judge. That is, it is actually difficult to detect the inclination K = 0.
Further, even when the variation value H is determined to be substantially minimum as described above, as shown in FIG. 7, the possibility that a smaller value will actually appear after that cannot be denied, but a smaller value appears. If not, the time required for control up to that point is wasted. Therefore, the above determination method is adopted in consideration of the control efficiency.

  FIG. 8 shows a case where unbalance cancellation is determined using only the threshold value in step S5, and a case where the minimum value determination (minimum value search) in step S7 is performed in addition to this, as in this embodiment. The difference of the vibration amplitude of the water tank 5 is compared. As is clear from this figure, by performing the minimum value determination of the fluctuation value H, the vibration amplitude is reduced to 1 mm or more and close to ½.

As described above, according to this embodiment, the control microcomputer 54 determines the fluctuation value H indicating the rotation fluctuation level of the motor 14 generated when the dehydrating operation is started based on the q-axis current obtained by the vector control. When it is calculated and it is determined that the fluctuation value H is substantially the minimum, the rotational speed of the motor 14 is increased by the maximum torque.
In other words, the rotation speed of the drum 7 is rapidly increased to the maximum rotation speed set in the dehydration operation when it is estimated that the imbalance of the laundry distribution in the interior is eliminated as much as possible. The state in which the laundry is substantially uniformly attached to the inner peripheral wall surface of the door is fixed as it is, and the dehydration operation is performed. Therefore, the unbalance of the laundry distribution accommodated in the drum 7 can be eliminated as much as possible according to the actual operation state, and the generation of noise and vibration during the dehydration operation can be further suppressed.

  When the control microcomputer 54 determines that the fluctuation value H is substantially minimum in a state where the fluctuation value H is below the predetermined threshold value, the rotation speed of the motor 14 is increased by the maximum torque. It can be avoided that it is determined to be substantially the minimum in a case where the fluctuation value H repeatedly changes up and down in a high region. Further, the control microcomputer 54 increases the rotational speed of the motor 14 with the maximum torque when it is determined that the fluctuation value H first shows a substantially minimum value based on the value of the slope K of the fluctuation value H and its sign. Therefore, it is possible to make a reasonable judgment at the time point at which the time is substantially minimum.

  In addition, when the rotational speed of the motor 14 is continuously increased or decreased, the control microcomputer 54 is in the vicinity of the rotational speed at which gravity and centrifugal force acting on the laundry accommodated in the drum 7 are balanced ( 40 rpm to 80 rpm), it is determined whether or not the fluctuation value H shows a substantially minimum value. Therefore, by making a determination in the range of the number of revolutions with a high probability that the unbalance is eliminated, the processing ability required for the control microcomputer 54 to make the determination can be reduced.

(Second embodiment)
11 to 15 show a second embodiment of the present invention. The same parts as those of the first embodiment are denoted by the same reference numerals and the description thereof is omitted, and only different parts will be described below. In the block diagram of the control system shown in FIG. 11, a control microcomputer (control means, variable value output means) 55 instead of the control microcomputer 54 is configured to perform control with reference to the d-axis current obtained by vector control. Has been.

  In the flowchart shown in FIG. 12, when the control microcomputer 55 detects the fluctuation value H in step S4, it reads the d-axis current value output by the αβ / dq converter 38 (step S11). Then, if the stator temperature of the motor 14 is estimated based on the d-axis current value (step S12), the rotor temperature is further estimated from the stator temperature (step S13). When the fluctuation value H is corrected based on the estimated rotor temperature (step S14), the process proceeds to step S5.

  Here, the reason why the variation value H is corrected by the rotor temperature will be described. As shown in FIG. 13, as the motor temperature (here, the temperature of the stator) increases, the value of the fluctuation value H (before correction) tends to increase. This mechanism is presumed as follows. As for the magnet used for the rotor which constitutes brushless motor 14, it is known that when temperature rises, output magnetic flux will fall slightly (about several percent of commas). When the output magnetic flux of the magnet is reduced, the output torque of the motor 14 is reduced by that amount. In order to compensate for the reduction of the torque, it is considered that the reason is that the amount of current flowing to the stator coil is increased in the closed loop control. It is done.

Therefore, it is ideal if the temperature of the rotor can be directly detected for correction. However, since it is difficult to measure the temperature of the rotating rotor, the temperature of the stator at a position close to the rotor is detected. . As shown in FIG. 14, since there is a correlation between the stator temperature and the rotor temperature, the rotor temperature can be estimated based on the stator temperature.
The temperature of the stator can also be detected directly using a temperature sensor or the like, but the d-axis current in vector control is an exciting current component, and is therefore substantially equal to the amount of current that is passed through the stator coil. If the amount of current supplied to the stator coil is known, it can be predicted in advance how much heat is generated according to the resistance of the coil. In FIG. 15, the vertical axis represents the d-axis current value and the horizontal axis represents the stator temperature, and both are in an inversely proportional relationship.

Therefore, when the control microcomputer 55 obtains the d-axis current value when a predetermined voltage is output, the control microcomputer 55 estimates the stator temperature from the current value based on the data table of FIG. 15, and further based on the data table of FIG. To estimate the rotor temperature. In step S14, the fluctuation value H is corrected by the following equation.
Hc = H / (ΔB (T−20) +1)
Here, Hc is the corrected fluctuation value, ΔB is the temperature coefficient of the rotor magnet, and T is the temperature (° C.). In other words, the correction is performed at a ratio with the temperature of 20 ° C. as the reference “1”. By performing the correction as described above, as shown in FIG. 13, the corrected fluctuation value Hc does not increase with an increase in temperature, and shows a substantially flat value. Therefore, the fluctuation value H used in steps S5 and S6 is actually the fluctuation value Hc after correction.

  As described above, according to the second embodiment, the control microcomputer 55 corrects the fluctuation value H based on the rotor temperature, so that an accurate fluctuation value can be obtained even when the operating environment temperature of the motor 14 changes. Thus, unbalance correction can be performed with higher accuracy. Since the control microcomputer 55 detects the temperature of the stator coil of the motor 14 and estimates the temperature of the rotor from the coil temperature, the temperature can be appropriately determined without directly detecting the temperature of the rotating rotor. Can be estimated.

  Further, the control microcomputer 55 estimates the rotor temperature based on the d-axis current obtained in the vector control, and calculates the fluctuation value H based on the q-axis current. Therefore, without using a temperature sensor or a vibration sensor. The rotation variation state of the drum 7 can be detected, and the temperature correction of the variation value H can be performed.

The present invention is not limited to the embodiments described above and shown in the drawings, and the following modifications or expansions are possible.
Only one of the two unbalance correction operation patterns shown in FIGS. 3 and 4 may be performed. If the unbalance is not resolved even if any one of the unbalance correction operation patterns is performed, the other The driving pattern may be executed.
The unbalance cancellation determination is not necessarily performed in the rotation speed range of 40 rpm to 80 rpm, and may be performed over other ranges.

  For example, if it is known in advance that the amount of laundry to be input is relatively small by performing a separate laundry weight determination process, step S5 is deleted and only unbalanced at step S7. You may perform cancellation determination. That is, when the amount of laundry is relatively small, the laundry is likely to stick uniformly to the inner peripheral surface of the drum 7, and there is little possibility that the balance state once once becomes substantially uniform will be lost. It is because it is assumed that the tendency to decrease simply is shown.

When accelerating the motor 14 when it is determined that the unbalance is eliminated, it is not always necessary to perform the maximum torque (that is, the maximum acceleration), but at least. What is necessary is just to give a bigger acceleration than the acceleration in an unbalance correction driving | operation.
The variation value may be detected using a vibration sensor, and the stator temperature may be detected using a temperature sensor.

Further, the temperature of the rotor may be directly detected using an infrared sensor or the like.
The motor drive control is not limited to vector control, but may be PI (proportional integration) control, for example.

The flowchart which is 1st Example of this invention and shows mainly the imbalance cancellation determination process performed at the time of dehydration operation start. The flowchart which shows the detection process of the q-axis current fluctuation value H in step S4 of FIG. The figure which shows the change pattern of rotation speed when the unbalance correction rotation in step S2 of FIG. The figure which shows the change pattern of a rotation speed when the same unbalance correction rotation is performed by a gradual fall. It is an example at the time of performing balance control in a spin-drying | dehydration process, (a) shows the vibration displacement of a drum, (b) shows the change of the fluctuation value H based on the vibration displacement, (c) shows the change of the rotation speed of a drum. Figure The figure which shows the state which performs the minimum determination about the fluctuation value H The figure which shows the case where a smaller value appears after determining the minimum of the fluctuation value H first. The figure which compared the difference in the vibration amplitude of a water tank with the case where determination of imbalance cancellation is performed only using the threshold value in step S5, and in addition, when the minimum value determination of step S7 is performed. Functional block diagram showing the configuration of the control system of the drum type washing machine Longitudinal side view showing the overall configuration of the drum type washing machine FIG. 9 equivalent view showing a second embodiment of the present invention. 1 equivalent diagram The figure which shows the fluctuation value H which is not temperature-corrected, and the fluctuation value H which was temperature-corrected Diagram showing correlation between rotor temperature and stator temperature in motor Diagram showing the relationship between d-axis current value and stator temperature The figure which shows the force which acts on the laundry in a rotating drum in a general drum type washing machine (A) is a state where the distribution of some laundry is biased, (b) is a diagram showing a state where the bias of (a) is eliminated

Explanation of symbols

In the drawings, 7 is a drum (rotating tank), 14 is a motor, and 54 and 55 are control microcomputers (control means, fluctuation value output means).

Claims (7)

A rotating tub for accommodating laundry, the rotating shaft being arranged so as to be oriented substantially in the horizontal direction;
A motor for rotating the rotating tank;
Control means for controlling the driving of the motor;
Fluctuation value output means for calculating and outputting a fluctuation value indicating a rotation fluctuation level of the motor generated when dehydration operation is started,
When the control means determines that the variation value is substantially minimum, the control means increases the rotational speed of the motor by an acceleration larger than the acceleration so far.   2. The drum type washing machine according to claim 1, wherein the control means increases the rotational speed of the motor at a larger acceleration when it is determined that the fluctuation value is substantially minimized in a state where the fluctuation value is below a predetermined determination value.   Based on the value of the time change rate of the fluctuation value and the sign indicated by the time change rate, the control means increases the rotation speed of the motor at a higher acceleration when it is determined that the fluctuation value first shows a substantially minimum value. The drum type washing machine according to claim 1 or 2, wherein   When the rotational speed of the motor is continuously increased or decreased, the control means has a fluctuation value that is substantially minimum in the vicinity of the rotational speed at which gravity and centrifugal force acting on the laundry contained in the rotating tub are balanced. The drum type washing machine according to any one of claims 1 to 3, wherein it is determined whether or not to show.   The drum type washing machine according to any one of claims 1 to 4, wherein the fluctuation value output means corrects the fluctuation value based on a temperature of the rotor.   6. The drum type washing machine according to claim 5, wherein the fluctuation value output means detects the winding temperature of the motor and estimates the rotor temperature from the winding temperature. The control means is configured to vector control the motor,
7. The drum type laundry according to claim 5, wherein the fluctuation value output means estimates the rotor temperature based on the d-axis current obtained in vector control and calculates the fluctuation value based on the q-axis current. Machine.

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