JP2016123860A - Vibration reduction method in dewatering of washing machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To allow unbalance and a ball to oppose to each other accurately when rotation of a spin basket passes the resonance rotation number.SOLUTION: This is a vibration reduction method in dewatering of a washing machine 10 which includes a ball balancer 40 in a spin basket 20. The spin basket 20 is rotated at predetermined measurement rotational frequency N1. The vibration period T1 of the spin basket 20 which generates from a relative positional relationship between unbalance and a ball 42 generating in the spin basket 20 is measured. Acceleration start timing in which the ball 42 and the unbalance are in resonance time antiphase arrangement where they are opposed to each other when the rotational frequency of the spin basket 20 passes the resonance rotation number Nx is acquired based on the vibration period T1, in the case where acceleration is started from the measurement rotational frequency N1 at constant acceleration.SELECTED DRAWING: Figure 8

Description

  The present invention relates to a method for reducing vibration during dehydration of a washing machine.

  In the washing machine, there is a problem in that the spin basket is unbalanced due to uneven distribution of the laundry during dehydration, which generates large vibrations and noise. In order to cope with this problem, a ball balancer is installed in the spin basket to reduce its vibration.

  The ball balancer is an annular member, and a plurality of balls are housed in the inside thereof together with oil. When the spin basket is rotated at a speed higher than the resonance rotational speed at which resonance (primary resonance) occurs, the ball moves so as to face the unbalance (in opposite phase). Therefore, by installing a ball balancer in the spin basket, the imbalance is offset and vibration can be reduced.

  However, in order to increase the rotation speed of the spin basket to such a rotation speed, the spin basket must pass through the resonance rotation speed. At that time, if the ball is positioned on the unbalanced side, a very large vibration is generated. For this reason, when the rotation speed of the spin basket passes the resonance rotation speed, it is preferable to make the balls face each other in an unbalanced manner, and various methods have been proposed for arranging the balls in such a manner.

  For example, in Patent Document 1, when the spin basket is rotated at a rotation speed that is lower than the resonance rotation speed and the ball circulates, and the ball faces the unbalance in that state, the rotation speed exceeding the resonance rotation speed is increased at once. A method for increasing the rotational speed is disclosed.

  Patent Document 2 discloses a method of controlling the arrangement of balls by adjusting the acceleration of a rotating spin basket. Specifically, the spin basket is rotated at a rotational speed lower than the resonance rotational speed and the ball circulates, and in this state, information such as unbalance and the position of the ball is grasped. Based on the information, the acceleration is adjusted based on the unbalance during acceleration and the relative positional relationship of the ball, and the unbalance and the ball are controlled to face each other when the spin basket passes through the resonance rotational speed.

  Further, Patent Document 3 discloses a method for increasing the rotational speed from a state where the ball is biased to the bottom to a resonant rotational speed within a predetermined time based on conditions obtained from experimental results.

JP 2013-34686 A JP 2013-223621 A JP 2014-79487 A

  Variations in the amount of ball movement may occur due to changes in the viscosity of oil due to temperature changes, machine differences among washing machines, and the like. Therefore, when controlling the rotation of the ball, if such an external factor is not taken into consideration, the position of the ball when the spin basket passes through the resonance rotational speed is shifted and vibrations increase.

  In addition, while the optimal arrangement of the balls is pinpoint, the rotation speed of the balls when the spin basket passes the resonance rotational speed is high. It is not easy to make them face each other with high accuracy.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a washing machine that can make the unbalance and the ball face each other with high accuracy when the rotation of the spin basket passes through the resonance rotational speed, and can effectively reduce vibration during dehydration. There is.

  The present invention is a method of reducing vibration during dehydration of a washing machine having a ball balancer in a spin basket that accommodates laundry, wherein the ball of the ball balancer circulates at a lower rotational speed than the spin basket. A test rotation step of rotating at a predetermined measurement rotation number, and vibrations of the spin basket caused by a relative positional relationship between the unbalance generated in the spin basket and the ball due to the eccentric distribution of the laundry in the test rotation step A vibration period measuring step for measuring a period, and when the rotational speed of the spin basket passes the resonant rotational speed when accelerating from the measured rotational speed at a predetermined constant acceleration, the ball and the unbalance Acceleration start timing at which the opposite phase arrangement at the time of resonance is opposed to the vibration Including an acceleration start timing acquisition step of acquiring, based on the period, the.

  According to this vibration reduction method, the vibration period is measured by rotating the spin basket at the measured rotational speed. However, the vibration period is affected by changes in the viscosity of oil due to temperature changes and machine differences in the washing machine. Change. Therefore, by setting the acceleration start timing using this vibration cycle for each dehydration process, an external factor can be excluded from the setting of the acceleration start timing, and the anti-resonance phase arrangement can be obtained with high accuracy.

  And since it accelerates from a measurement rotation speed with the fixed acceleration set beforehand, the time (acceleration start time) from passing acceleration start to resonance rotation speed is specified. Since the acceleration start timing is acquired from the acceleration start time and the vibration period, even when the ball's orbiting speed is high, a highly accurate acceleration start timing can be acquired, and the rotation of the spin basket passes through the resonance rotation speed. Sometimes, the unbalance and the ball can be opposed to each other with high accuracy.

  Specifically, the measured rotational speed is preferably the rotational speed when rotation starts and the laundry is stuck on the inner peripheral surface of the spin basket and cannot move.

  If it does so, since a measurement rotation speed becomes the minimum and a vibration period becomes large, a vibration period is stabilized and a highly accurate vibration period can be acquired.

  More specifically, in the acceleration start timing acquisition step, the moving speed of the ball obtained from the equation of motion and the rotation speed of the spin basket are accelerated by the acceleration to reach the resonance rotation speed from the measured rotation speed. It is preferable to include a ball movement amount calculating step of calculating a movement amount of the ball having the anti-resonance phase arrangement by using the time required for the rotation.

  By doing so, the amount of movement of the ball is calculated based on a dynamic function, so that the amount of movement of the ball can be estimated with high accuracy even when the ball has a high revolving speed.

  Further, the acceleration start timing obtaining step calculates a ball movement amount calculating step for calculating a movement amount of the ball having an antiphase arrangement at the time of resonance using map information in which the vibration period and the resonance rotation speed are associated with each other. May be included.

  By doing so, since the amount of calculation processing can be reduced, it can be easily realized without a high processing speed and processing capability.

  Furthermore, an acceleration step of accelerating the rotation of the spin basket at the acceleration start timing, a vibration amount monitoring step of monitoring the vibration amount of the spin basket in the acceleration step, and when the vibration amount exceeds a predetermined value A deceleration step for decelerating the rotation of the spin basket to the measured rotational speed, a correction amount setting step for setting a correction amount for correcting the acceleration start timing, and correcting the acceleration start timing based on the correction amount Thus, a resetting step for newly setting the acceleration start timing and a reacceleration step for reacceleration without stopping the spin basket by the reset acceleration start timing may be included.

  In the case of this rotation control, the amount of vibration is monitored when the spin basket is accelerated, and when the amount of vibration exceeds a predetermined amount, the spin basket is decelerated to the measured rotational speed and reset based on the correction amount. At the new acceleration start timing, the spin basket is re-accelerated without stopping.

  In this way, when the amount of vibration of the spin basket increases, the spin basket is once decelerated and then the spin basket is re-established based on a new acceleration start timing reset to reduce the amount of vibration. Since the accuracy can be improved by re-acceleration, vibration at the time of passing through the resonance rotational speed can be further reduced.

  In addition, since such re-acceleration operation is performed without stopping the spin basket, the dehydration time is shortened compared to when the spin basket is stopped when the amount of vibration of the spin basket increases. it can.

In this case, the correction amount T3, the measured rotational speed N1, the rotational speed N2 of the spin basket when the vibration amount exceeds a predetermined amount, and the rotational speed N3 slightly lower than the resonant rotational speed (N1 <N3 <resonant) Satisfying the rotational speed and setting at a resonant rotational speed of about −10 rpm), the acceleration α is
T3 = (N3-N2) / α
It is better to set to satisfy the condition.

  By setting the correction amount T3 so as to satisfy the above-described conditional expression, the correction amount T3 can be set under an optimum condition that particularly takes into consideration the rotation speed N2 of the spin basket when the vibration amount exceeds a predetermined amount. it can.

  Furthermore, a storage unit for storing the correction amount may be provided, and the correction amount read from the storage unit may be used in the correction amount setting step.

  Since the correction amount is stored in the storage unit and the acceleration start timing read out and reset in the subsequent dehydration process can be used, the re-acceleration step can be omitted and the dehydration time can be shortened.

  According to the vibration reducing method of the present invention, the unbalance and the ball can be opposed to each other with high accuracy when the rotation of the spin basket passes through the resonance rotational speed, so that vibration during dehydration is effectively reduced. A washing machine capable of being provided can be provided.

It is side surface sectional drawing which shows the structure of the washing machine in this embodiment. It is front sectional drawing of a balancer. It is side surface sectional drawing of a balancer. It is a block diagram which shows the main structures of a washing machine. It is a block diagram which shows the main structures of a calculating part. It is a figure explaining operation | movement of a spin basket and a ball balancer. It is a flowchart explaining 1st rotation control. It is a time chart explaining the 1st rotation operation. It is a figure explaining a vibration period. It is a flowchart explaining 2nd rotation control. It is a time chart explaining the 2nd rotation operation. It is the schematic which shows the relationship between the relative position of unbalance and a ball | bowl, and the code | symbol of the correction amount at that time (when T3> 0). It is the schematic which shows the relationship between the relative position of unbalance and a ball | bowl, and the code | symbol of the correction amount at that time (when T3 <0).

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. However, the following description is merely illustrative in nature and does not limit the present invention, its application, or its use.

<Structure of washing machine>
In FIG. 1, the washing machine of this embodiment is shown. The washing machine 10 is a fully automatic drum-type washing machine that can automatically perform a series of processes of washing, rinsing, and dewatering. The washing machine 10 is installed on a floor surface or the like, and has a housing 11 having a loading port on a front surface facing sideways (right side in FIG. 1), a tab 12 disposed inside the housing 11, and a tab 12 The spin basket 20 rotatably provided inside the motor and a motor 30 that rotates the spin basket 20 about the rotation axis L are provided.

  The tab 12 has a bottomed cylindrical shape with an opening formed on the front side, and is arranged so that its central axis is substantially parallel to the floor surface or the like. The tab 12 is supported by a plurality of springs 13 and dampers 14 inside the housing 11. A bearing 15 is provided on the bottom surface of the tab 12.

  The spin basket 20 includes a cylindrical side plate 21 in which a large number of drain holes are formed, and a front plate 22 and a rear plate 23 that are respectively coupled to the front and rear surfaces of the side plate 21. The front plate 22 is formed with an opening, and the laundry W can be taken in and out of the spin basket 20 through the opening.

  Further, on the rear side (left side in FIG. 1) of the rear plate 23, a main shaft 24 that allows the spin basket 20 to rotate about the rotation axis L is provided. The main shaft 24 is pivotally supported by the bearing 15 and is arranged so that the rotation axis L and the central axis of the tab 12 coincide. A ball balancer 40 is installed on the front plate 22 of the spin basket 20.

  As shown in FIGS. 2 and 3, the ball balancer 40 has a hollow annular race 41. Inside the race 41, oil 43 as a viscous fluid and a plurality of balls 42 (eight in FIG. 2). ) And is housed. The ball balancer 40 is disposed concentrically with the spin basket 20 around the rotation axis L, and is configured such that a plurality of balls 42 can circulate as the spin basket 20 rotates.

  The motor 30 is a DC motor, for example, and rotates the main shaft 24. A rotation speed sensor 31 for measuring the rotation speed, a current sensor 32 for measuring the drive current, a weight sensor 33 for measuring a weight change of the spin basket, and the like are attached to the motor 30. The weight of the laundry W before the dehydration process can be measured by using the weight sensor 33.

  Measurement values measured by these sensors are output to the control device 50 installed in the housing 11. The control device 50 controls the rotation of the motor 30 in each process of washing, rinsing, and dehydration by using these measured values.

  FIG. 4 shows a main configuration related to the control device 50. The control device 50 includes a rotation control unit 51, a vibration amount monitoring unit 52, a calculation unit 53, a storage unit 54, and the like. The rotation control unit 51 controls the rotation operation of the motor 30 using the measurement value or the like input from the rotation number sensor 31. The vibration amount monitoring unit 52 monitors the vibration amount of the spin basket 20 using a measurement value or the like input from the current sensor 32.

  The calculation unit 53 performs various data processing and calculations in cooperation with the vibration amount monitoring unit 52 and the storage unit 54, and controls the rotation of the motor 30 in cooperation with the rotation control unit 51. The storage unit 54 is composed of, for example, an EEPROM, stores various data such as acceleration, map data, and correction amount described later, and inputs / outputs information to / from the calculation unit 53.

  As shown in FIG. 5, the calculation unit 53 includes a vibration cycle measurement unit 53a, a resonance rotation number calculation unit 53b, an acceleration start timing acquisition unit 53c, a correction amount setting unit 53d, and the like. The vibration period measuring unit 53a measures the vibration period T1 of the spin basket 20 that is generated from the relative positional relationship between the unbalance and the ball 42 when the spin basket 20 is rotating at the measurement rotational speed N1.

  The resonance rotation speed calculation unit 53b calculates the resonance rotation speed Nx of the spin basket 20 including the laundry W during the dehydration process. The acceleration start timing acquisition unit 53c accelerates from the measured rotational speed N1, and when the rotational speed of the spin basket 20 passes through the resonant rotational speed Nx, the ball 42 and the unbalance are opposed to each other. The start timing of acceleration that becomes (placement) is acquired. The correction amount setting unit 53d sets a correction amount T3 used for correcting the acceleration start timing.

(Start-up at the time of dehydration)
When the washing and rinsing processes are completed, the water inside the tub 12 and the spin basket 20 is drained to the outside, and the dehydration process is performed. In the dehydration process, the spin basket 20 is rotated for a certain time at a high rotation speed (target rotation speed) of, for example, 1000 RPM or more, and the laundry W is dehydrated by the action of centrifugal force.

  When the rotation speed of the spin basket 20 increases to some extent, the laundry W during the dehydration process sticks to the inner peripheral surface of the spin basket 20 and does not move. At that time, the position where the laundry W sticks is unspecified, and the laundry W is normally distributed in a biased state. Therefore, unbalance occurs in the spin basket 20 (in each figure, the laundry W represents the position of the unbalance in the circumferential direction). In order to cancel the unbalance, a ball balancer 40 is installed.

  When the spin basket 20 is not rotating, the balls 42 are gathered vertically downward by the action of gravity, and start to move up and down as the rotation of the spin basket 20 starts. Then, as the rotational speed of the spin basket 20 increases, the amount of movement of the ball 42 also increases. After that, when the centrifugal force overcomes gravity, the ball 42 rotates in the rotational direction of the spin basket 20 as shown in FIG. It turns around in the opposite direction (clockwise in FIG. 6) (counterclockwise in FIG. 6).

  At a rotational speed lower than the resonant rotational speed Nx, the moving speed of the ball 42 is slower than the unbalanced moving speed (the rotational speed of the spin basket 20), and the relative position in the circumferential direction of the unbalance and the ball 42 varies.

  At a rotational speed higher than the resonant rotational speed Nx, the ball 42 automatically moves so as to cancel the unbalance. Therefore, vibration and noise are reduced when the spin basket 20 is rotating at such a high speed.

  However, in the process of increasing the rotation speed of the spin basket 20 to the target rotation speed, the spin basket 20 must pass through the resonance rotation speed Nx. At that time, if the ball 42 is positioned on the unbalanced side, a very large vibration is generated. Therefore, in this washing machine 10, when the rotation speed of the spin basket 20 passes the resonance rotation speed Nx, the rotation of the spin basket 20 can be controlled with high accuracy so that the ball 42 and the unbalance face each other. It has become.

<First rotation control>
FIG. 7 shows the flow of rotation control (first rotation control) of the spin basket 20, and FIG. 8 shows a time chart of the rotation operation of the ball 42 during the control. The first control includes a test rotation step, a resonance rotation speed measurement step, a vibration cycle measurement step, an acceleration start timing acquisition step, an acceleration step, and the like.

(Test rotation step)
In the test rotation step, the spin basket 20 is rotated while being held at a predetermined measurement rotation speed N1 (step S10). The measured rotational speed N1 is a rotational speed at which the ball 42 goes around at a lower speed than the resonant rotational speed Nx, such as 100 RPM.

  The lower the rotation speed, the larger the vibration period T1 and the higher-accuracy vibration period T1 can be acquired. Therefore, the measured rotation speed N1 is preferably as low as possible. Therefore, in the washing machine 10, the rotation speed when the rotation starts and the laundry W sticks to the inner peripheral surface of the spin basket 20 and cannot move is set as the measurement rotation speed N1.

  At this time, as shown in FIG. 6, the ball 42 circulates at a constant speed in the direction opposite to the rotation direction of the spin basket 20.

(Resonance speed measurement step)
In the resonance speed measurement step, the resonance speed Nx of the spin basket 20 including the laundry W is acquired by the resonance speed calculation unit 53b (step S11). Specifically, the weight M0 of the laundry W from which most of the water has been removed is measured by the weight sensor 33, and the weight M0, the weight M of the spin basket 20, the spring constant k, and the following equation (1) are obtained. By using this, the resonance rotational speed Nx is acquired.

(Vibration cycle measurement step)
In the vibration cycle measurement step, the vibration cycle measurement unit 53a performs a process of measuring the vibration cycle T1 of the spin basket 20 resulting from the relative positional relationship between the unbalance and the ball 42 in the test rotation step (step S12). . The vibration period measurement unit 53a measures the vibration period T1 of the spin basket 20 from the change in the drive current input from the current sensor 32.

  FIG. 9 shows an example of the change in the drive current. In the test rotation step, since both the unbalance and the ball 42 orbit at a constant speed, the relative position changes periodically. When the unbalance and the ball 42 are located on the same side (same phase), the vibration is maximized, and the amplitude of the drive current is also maximized. On the other hand, when the unbalance and the ball 42 face each other (opposite phase), the vibration is minimized and the amplitude of the drive current is also minimized. Since such a change occurs at a constant period, the vibration period measurement unit 53a measures the vibration period T1, such as the time from peak to peak.

  The vibration period T1 changes under the influence of a change in the viscosity of the oil 43 due to a temperature change, a machine difference of the washing machine 10, and the like. Therefore, by setting the acceleration start timing using this vibration period T1 for each dehydration process, it is possible to eliminate external factors from the setting of the acceleration start timing, and to acquire the anti-resonance phase arrangement with high accuracy. .

(Acceleration start timing acquisition step)
In the acceleration start timing acquisition step, when the acceleration start timing acquisition unit 53c accelerates from the measured rotational speed N1 at a constant acceleration preset in the storage unit 54, the acceleration start timing that becomes the reverse phase arrangement at resonance is obtained. A process of obtaining based on the vibration period T1 is performed (step S13).

  Specifically, using the moving speed of the ball 42 obtained from the equation of motion and the time ΔT required for the rotational speed of the spin basket 20 to be accelerated to reach the resonant rotational speed Nx from the measured rotational speed N1, the resonance is achieved. A process of calculating the movement amount of the ball 42 in the time-reverse phase arrangement is performed (ball movement amount calculation step).

  The storage unit 54 stores the following expressions (2), (3), and (4).

  Expression (2) is an equation of motion of the ball 42 that goes around the race 41. μ is the friction coefficient of the race 41, R is the radius of rotation of the ball 42 (the radius of the race 41), m is the mass of the ball 42, A is the acceleration, and ωBall represents the moving speed of the ball 42.

  Expression (3) is an expression for calculating a time (acceleration start time) ΔT required for the rotation speed of the spin basket 20 to be accelerated to reach the resonance rotation speed Nx from the measurement rotation speed N1. Since the acceleration A is constant, the acceleration start time ΔT is specified by the measured rotation speed N1 and the resonance rotation speed Nx, and can be easily calculated from these.

  Equation (4) uses the acceleration start time ΔT calculated by Equation (3), and the amount of movement Δθ of the ball 42 that is in antiphase arrangement during resonance, that is, from the position where the ball 42 exists at the acceleration start timing, This is an equation for calculating the movement amount Δθ of the ball 42 up to a position where the unbalance and the ball 42 face each other (the phase difference becomes π) when the rotation speed of the spin basket 20 passes the resonance rotation speed Nx.

  The acceleration start timing acquisition unit 53c performs calculations using these equations (2) to (4) to acquire the movement amount Δθ of the ball 42.

  When the movement amount of the ball 42 is larger than π, the ball 42 passes through the unbalance near the resonance rotational speed Nx and the vibration becomes larger. Therefore, the movement amount Δθ of the ball 42 should be smaller than π. preferable. Therefore, in the washing machine 10, the acceleration A is set higher than a predetermined lower limit value.

  Specifically, the lower limit value of the acceleration A is acquired using Expression (3) and the following Expressions (5) and (6).

  α · Nx (0 <α <1) is a rotational speed in the vicinity of the resonant rotational speed Nx that generates a large vibration when the unbalance and the ball 42 are in the same phase at a rotational speed higher than this, and is obtained by testing or the like. It is done. By using these equations, the lower limit value of the acceleration A can be calculated.

  This point will be described in detail using a specific example. In addition, since it will become complicated if the moving speed of the ball | bowl 42 is calculated from an equation of motion, in the description, the moving speed of the ball | bowl 42 is handled as (omega) 0 (constant).

  From the equation (5), the following equation (7) is obtained.

  By substituting the equations (3) and (6) into this, the following equation (8) is obtained, and the inequality (9) is obtained as the solution.

  Here, when the vibration period T1 is 40 seconds, the moving speed of the ball is expressed by the following equation (10).

  Assuming that the measured rotational speed N1 is 100 RPM, the resonant rotational speed Nx is 170 RPM, and α is 0.3, the lower limit value of the acceleration A is obtained by the following equation (11).

(Acceleration step)
In the acceleration step, the rotation control unit 51 determines whether or not a specific acceleration start timing based on the movement amount Δθ of the ball 42 has been reached (step S14). The acceleration of the spin basket 20 is started at a constant acceleration A (step S15).

  By doing so, when the rotation speed of the spin basket 20 passes the resonance rotation speed Nx, the ball 42 and the unbalance can be opposed to each other with high accuracy, and vibration during dehydration can be effectively reduced.

<Second rotation control>
Further, the washing machine 10 is configured to perform rotation control (second rotation control) that corrects the acceleration start timing to increase accuracy. The rotation control will be described with reference to FIGS.

  In the test rotation step, in order to correct the acceleration start timing, the acceleration start timing acquisition unit 53c reads the correction amount T3 stored in the storage unit 54, and updates the acceleration start time T2 based on the correction amount T3. Then, a new acceleration start time T2 ′ is set (step S104).

  In the first dehydration process, since the correction amount T3 is not stored in the storage unit 54, the acceleration start time T2 ′ = T2, but thereafter, the acceleration start time T2 ′ considering the correction amount T3 is set from the beginning. Can be used.

  When the acceleration start timing is reached (YES in step S105), the rotation control unit 51 controls the motor 30 to accelerate the spin basket 20 with the acceleration A (step S106).

  The vibration amount monitoring unit 52 monitors the vibration amount S of the spin basket 20, and determines whether the vibration amount S exceeds a predetermined amount X1 when the rotation speed of the spin basket 20 passes the resonance rotation speed Nx. (Step S107). If the vibration amount S does not exceed the predetermined amount X1, the correction amount T3 at this time is written in the storage unit 54, and the process is terminated (step S111).

  When the vibration amount S exceeds the predetermined amount X1, the rotation control unit 51 controls the motor 30 to decelerate the rotational speed of the spin basket 20 to the measured rotational speed N1 (step S108). In FIG. 11, the ball 42 passes through the opposite phase position with respect to the unbalance and moves toward the same phase position with the unbalance, and the amount of vibration is larger than the predetermined amount X1, so that the ball 42 is decelerated.

  Then, the correction amount T3 is calculated by substituting the rotational speed N2 of the spin basket 20 when the vibration amount S exceeds the predetermined amount X1 into the following conditional expression (1) (step S109).

T3 = (N3-N2) / α (1)
Here, N3 is a rotational speed slightly lower than the resonant rotational speed Nx, and α is an acceleration for accelerating the spin basket 20 from the rotational speed N1 to the rotational speed N2.

  Based on the calculated correction amount T3, the acceleration start time T2 'is updated and reset (step S110).

  In the present embodiment, when the spin basket 20 is accelerated at the acceleration start time T2 ', the ball 42 passes through the unbalanced facing position. Therefore, at the time of reacceleration, the acceleration start time T2 ′ is shortened by setting the sign of the correction amount T3 to be minus so that the acceleration is started before the acceleration timing of the spin basket 20 (FIG. 12B). reference).

  On the other hand, when the spin basket 20 is accelerated at the acceleration start time T2 ′ and the ball 42 does not pass through the unbalanced opposing position, the reacceleration is performed after the acceleration timing of the spin basket 20. The acceleration start time T2 ′ is lengthened by setting the sign of the correction amount T3 to be plus so that the acceleration starts from (see FIG. 12A).

  After the acceleration start time T2 'is reset in step S110, the spin basket 20 is reaccelerated using the new acceleration start time T2', and the subsequent processing is continued.

  As described above, according to the second rotation control, when the vibration amount S of the spin basket 20 becomes large, the rotational speed of the spin basket 20 is once decelerated and then re-started to reduce the vibration amount S. Since the spin basket 20 is re-accelerated based on the set new acceleration start time T2 ′, vibration when passing through the resonance rotational speed Nx can be reduced.

  In addition, since such a reacceleration operation is performed without stopping the spin basket 20, compared to a case where an operation for stopping the spin basket 20 when the vibration amount S of the spin basket 20 is increased, The time for dehydration can be shortened.

  The vibration reducing method according to the present invention is not limited to the above-described embodiment, and includes various other configurations.

  In the embodiment, the equation of motion or the like is used in calculating the movement amount Δθ of the ball 42 that has an antiphase arrangement at the time of resonance, but the present invention is not limited thereto. For example, map information in which the vibration period T1 and the resonance rotational speed Nx are associated with each other is stored in the storage unit 54, and the movement amount Δθ of the ball 42 having an anti-phase arrangement at resonance is calculated using the map information. May be.

  Further, the equation of motion may be substituted by the following equation (12).

α is an adjustment coefficient. Since the amount of calculation processing can be reduced, it can be easily realized without a high processing speed and processing capability.

  The vibration period T1 may be measured by a vibration sensor. The acceleration start timing can also be acquired based on the amplitude of the vibration period T1 instead of the time of the vibration period T1.

DESCRIPTION OF SYMBOLS 10 Washing machine 20 Spin basket 30 Motor 40 Ball balancer 42 Ball 50 Controller W Laundry

Claims (7)

A method for reducing vibration during dehydration of a washing machine having a ball balancer in a spin basket for storing laundry,
A test rotation step in which the spin basket is rotated at a predetermined measurement rotation speed that a ball of the ball balancer goes around lower than a resonance rotation speed;
In the test rotation step, a vibration period measuring step for measuring a vibration period of the spin basket resulting from a relative positional relationship between an unbalance generated in the spin basket due to an eccentric distribution of the laundry and the ball;
When accelerating from the measured rotational speed at a predetermined constant acceleration, the ball and the unbalance are opposed to each other when the rotational speed of the spin basket passes the resonant rotational speed. An acceleration start timing acquisition step for acquiring the acceleration start timing based on the vibration period;
A method for reducing vibration including: The vibration reduction method according to claim 1,
The measured rotation number is a vibration reduction method that is a rotation number when rotation starts and the laundry is stuck to the inner peripheral surface of the spin basket and cannot move. In the vibration reducing method according to claim 1 or 2,
The acceleration start timing acquisition step includes the movement speed of the ball obtained from the equation of motion, the time required for the rotation speed of the spin basket to be accelerated by the acceleration and reach the resonance rotation speed from the measurement rotation speed, A vibration reduction method including a ball movement amount calculation step of calculating a movement amount of the ball having the anti-phase arrangement at the time of resonance by using the method. In the vibration reducing method according to claim 1 or 2,
The acceleration start timing acquisition step includes a ball movement amount calculation step of calculating a movement amount of the ball having the anti-phase arrangement at the time of resonance using map information in which the vibration period and the resonance rotation speed are associated with each other. Vibration reduction method. In the vibration reducing method according to claim 1 or 2,
An acceleration step of accelerating the rotation of the spin basket at the acceleration start timing;
A vibration amount monitoring step for monitoring a vibration amount of the spin basket in the acceleration step;
A decelerating step of decelerating the rotation of the spin basket to the measured rotational speed when the amount of vibration exceeds a predetermined value;
A correction amount setting step for setting a correction amount for correcting the acceleration start timing;
A resetting step for newly setting the acceleration start timing by correcting the acceleration start timing based on the correction amount;
And a re-acceleration step that re-accelerates the spin basket without stopping at the re-set acceleration start timing. The vibration reduction method according to claim 5,
The correction amount T3, the measured rotational speed N1, the rotational speed N2 of the spin basket when the vibration amount exceeds a predetermined amount, the rotational speed N3 slightly lower than the resonant rotational speed, and the acceleration α
T3 = (N3-N2) / α
Vibration reduction method that is set to satisfy the condition. In the vibration reduction method according to claim 5 or 6,
A storage unit for storing the correction amount;
A vibration reduction method in which the correction amount read from the storage unit is used in the correction amount setting step.

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