JP3148679B2 - Centrifugal dehydrator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for dewatering laundry or removing a solvent for washing by storing laundry in a basket-shaped drum and rotating the drum at high speed about a horizontal axis. The present invention relates to a centrifugal dehydrator to be executed (herein, it is referred to as a “centrifugal dehydrator” including a centrifugal dehydrator for a solvent). Needless to say, the present invention can be used for a washing machine or a washing / drying machine which continuously performs washing, dehydration, and drying.

[0002]

2. Description of the Related Art A drum type centrifugal dehydrator has a structure in which washed laundry is accommodated in a basket-shaped drum, and the drum is rotated at a high speed about a horizontal axis. One of the major problems with this type of centrifugal dehydrator is that when the drum is rotated at high speed while the laundry is not evenly distributed on the inner wall of the drum, abnormalities occur due to imbalance in the mass distribution around the rotation axis. Vibration and abnormal noise are generated. In a commercially available drum type washer / dryer equipped with such a centrifugal dehydrator, a weight is mounted around an outer tub in which a drum is installed in order to suppress the abnormal vibration. For this reason, this type of conventional washer-dryer was very heavy, and the installation place was limited, and it was difficult to move and transport.

[0003] Several drum-type centrifugal dehydrators for solving the above-mentioned problem of abnormal vibration have conventionally been proposed. For example, in the centrifugal dewatering device described in Japanese Patent Application Laid-Open No. 6-254294, a method is disclosed in which laundry is uniformly distributed and arranged on the inner peripheral wall of the drum by low-speed rotation of the drum before performing the dehydration operation by high-speed rotation of the drum. . More specifically, first rotate the drum at low speed for a very short time,
Then, the laundry is dispersed by a combination of two-stage rotation control of rotating the drum at a rotation speed slightly higher than the rotation speed but sufficiently lower than the rotation speed during the spin-drying operation.

In the above prior art, a vibration monitoring sensor is installed on a pedestal of the apparatus as means for detecting uneven distribution of laundry in a drum, and the rotation speed of the drum is increased to a high rotation speed for performing a dehydrating operation. Sometimes, when the vibration monitoring sensor detects abnormal vibration, the rotational speed is reduced.

[0005]

However, even if the method of controlling the rotation of the drum as in the above-mentioned prior art is used, the laundry is not always surely evenly distributed by one low-speed rotation of the drum. For this reason, after trying to disperse the laundry by low-speed rotation, the drum must be rotated at a high speed, and when abnormal vibration occurs, the rotational speed must be reduced again to re-distribute the laundry. If the dispersion of the laundry by the low-speed rotation of the drum and the detection of the eccentric load by the high-speed rotation are repeated a plurality of times in this manner, the dehydration time is prolonged.

[0006] For example, Japanese Patent Publication No. Hei 7-1000009 discloses a centrifugal dehydrator for adjusting the balance by adding a weight to a part of the inner peripheral wall of the drum. In this conventional centrifugal dehydrator, when the weight reaches the highest position of the drum, the laundry is determined to be in a position facing the weight with respect to the drum rotation axis due to gravity, and both are balanced. The drum shifts from low-speed rotation to high-speed dehydration rotation. However, even by such a method, it is not always possible to shift to the high-speed spinning rotation with the weight and the laundry being surely balanced, and it is not possible to completely prevent abnormal vibration during the spinning operation. Of course, it would be possible to balance by imposing strict conditions such as storing a predetermined weight of laundry in the drum according to the weight of the weight,
This is not practical in an actual centrifugal dehydrator.

In view of the above problems, the applicant of the present application has filed Japanese Patent Application
In JP-A-354520 and the like, a pocket-shaped liquid holding portion capable of temporarily holding water is formed in a part of a baffle of a drum, and a predetermined amount of water is injected into the liquid holding portion according to uneven distribution of laundry. Thus, a centrifugal dehydrator having a novel configuration for adjusting the balance of the entire drum has been proposed. In this centrifugal dehydrator, the drum is rotated at a rotation speed such that the centrifugal force acting on the laundry in the drum is slightly larger than the gravity, so that the laundry adheres to the inner peripheral wall of the drum and rotates. In this state, the magnitude of the eccentric load (the amount of eccentricity) is detected, and when the amount of eccentricity is within a predetermined value, the rotation speed of the drum is increased to shift to the dewatering operation. If the amount of eccentricity exceeds a predetermined value, the rotational speed of the drum is reduced, the laundry is loosened and rearranged, and the amount of eccentricity is detected again.

Since the above-mentioned predetermined value for determining the amount of eccentricity is a criterion for determining whether or not to shift to the dehydrating operation, if this criterion is too loose, abnormal vibration may occur during the dehydrating operation. Conversely, if the criterion is too strict, the eccentric state does not fall within the criterion even if the loosening operation is performed many times, and the dewatering operation is significantly prolonged, and the dewatering operation may not even end forever. Therefore, the reference value is set so that the vibration of the outer tub or outer box that houses the drum when the drum is rotated at a high speed is equal to or less than a predetermined amount, and that various types and amounts of clothing are appropriately loosened. It is determined in advance by a thorough experimentation so that the operation value will be less than the reference value in most cases. However, in practice, it is considerably difficult to determine an appropriate standard, and depending on the conditions for putting clothes, it is inevitable that the vibration increases during high-speed rotation and that the dehydration time is prolonged.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to accurately determine the amount of eccentricity before shifting to the dehydrating operation, thereby enabling an abnormality in the dehydrating operation. It is an object of the present invention to provide a centrifugal dewatering device capable of reliably preventing vibration and preventing a prolonged time required for dehydration due to too strict determination criteria.

[0010]

According to a first aspect of the present invention, there is provided a laundry machine in which laundry is accommodated in a basket-shaped drum and the drum is rotated about a horizontal axis. In a centrifugal dewatering device for dewatering goods, a) load amount detecting means for determining the amount of laundry stored in the drum, and b) eccentricity for detecting the amount of eccentricity which is the magnitude of the eccentric load of the drum. An amount detecting means, c) a deviation in detection due to a difference in the amount of laundry when detecting the amount of eccentricity in the eccentric amount detecting means, and a weight of the laundry when the drum is rotated at a high speed. In consideration of the vibration suppression effect, according to the amount of the laundry detected by the load amount detecting means, the amount of vibration when the drum is rotated at a high speed is substantially the same even if the amount of the laundry is different. Correcting means for correcting the amount of eccentricity detected by the eccentric load detecting means d) an eccentricity amount determining means for determining whether the eccentricity amount corrected by the correcting means is equal to or more than a predetermined reference value; ande) an eccentricity amount less than the reference value by the eccentricity amount determining means. And rotating control means for controlling a motor for rotating the drum so as to rotate the drum at a high speed when it is determined that the drum is present.

A second invention is a centrifugal dewatering device for storing laundry in a basket-shaped drum and rotating the drum about a horizontal axis to dewater the laundry. Load amount detecting means for determining the amount of laundry stored; b) eccentric amount detecting means for detecting an eccentric amount which is the magnitude of the eccentric load of the drum; c) eccentric amount detecting means. Considering the deviation of detection due to the difference in the amount of laundry when detecting the amount of eccentricity, and the effect of suppressing vibration due to the weight of the laundry when the drum is rotated at high speed, the amount of laundry is different. Even when the drum is rotated at a high speed, the reference value for determining the eccentric amount according to the amount of the laundry detected by the load amount detecting means is corrected so that the vibration amount when the drum is rotated at a high speed is substantially the same. And d) the eccentricity detected by the eccentricity detecting means is corrected. An eccentricity amount determining means for determining whether or not the eccentricity amount is equal to or more than a reference value corrected by the step; e) when the eccentricity amount is determined to be less than a predetermined value, the drum is driven at a high speed. And a rotation control means for controlling a motor for rotating the drum so as to rotate the drum.

In the centrifugal dehydrator according to the first and second inventions, the rotation control means rotates the drum at a rotational speed such that the laundry adheres to the inner wall surface of the drum by centrifugal force and rotates. In this case, the motor is controlled so that the eccentricity detecting means obtains the eccentricity based on the fluctuation component of the motor driving current accompanying rotation.

The rotation control means rotates the drum at a low speed in order to loosen and disperse the laundry when the eccentricity determination means determines that the eccentricity is equal to or larger than the reference value. And

Further, the load amount detecting means injects a predetermined amount of water into a drum in which the laundry is stored, detects the water level in the drum after allowing the laundry to contain water, and detects a water level due to water absorption. A configuration may be adopted in which the amount of laundry is determined according to the decrease.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS When a drum having an eccentric load is driven to rotate, when the eccentric load is lifted upward against the gravity, the gravity acting on the eccentric load is rotated. Acts in the opposite direction, so acts to slow down the rotational speed. On the other hand, after the eccentric load passes through the highest position of the drum, the gravitational force acting on the eccentric load acts in the same direction as the rotation direction, and thus acts to increase the rotation speed. For this reason, when the motor is controlled so as to maintain the rotation speed constant, the drive current of the motor fluctuates according to the eccentric load. That is, the fluctuation amplitude of the drive current corresponding to the rotation of the drum reflects the amount of eccentricity.

As a result of the experiment, the inventors of the present invention have found that the contribution of the eccentricity to the rotation speed as described above is not an absolute one depending only on the value of the eccentricity, but the load, that is, the load of the laundry. It was found to be relative depending on the amount. That is, when the load is large, the contribution of the eccentric amount is relatively small as compared with the case where the load is small. For this reason, the fluctuation amplitude of the drive current due to the eccentric load becomes smaller, and the degree of increase of the fluctuation amplitude with respect to the increase of the eccentric amount also becomes smaller. That is, the fluctuation amplitude is affected by the load amount and does not accurately reflect the eccentric amount (absolute amount). On the other hand, it has also been found that when the drum is rotating at a high speed for dehydration, the vibration is smaller when the load is larger, even with the same eccentricity, mainly due to the flywheel effect. As described above, the load affects the two correspondences, that is, the relationship between the eccentricity and the fluctuation amplitude of the drive current, and the relationship between the eccentricity and the vibration amplitude of the outer box during the dehydration operation. Turned out to be. For this reason,
Even if the fluctuation amplitude of the drive current is the same before shifting to the dehydration operation, the vibration amplitude of the outer case during the dehydration operation differs depending on the load amount.

Therefore, in the centrifugal dewatering device according to the first invention, based on the above-mentioned relationship which has been examined in advance, when the drum is rotated at a high speed, the vibration amplitude is substantially the same even if the load amount is different. The correction amount of the eccentricity amount (or the fluctuation amplitude of the drive current) according to the load amount is obtained in advance, and the correcting unit determines the eccentricity actually detected according to the load amount detected by the load amount detecting unit. Correct the amount. Then, the eccentricity amount determining means includes:
By determining whether the corrected eccentric amount is less than a predetermined reference value, it is determined whether the vibration amplitude falls within a predetermined range during the spin-drying operation.

In the centrifugal dehydrator according to the second aspect of the present invention, based on the above-mentioned relationship which has been checked in advance, when the drum is rotated at a high speed, the vibration amplitude becomes substantially the same even if the load differs. In addition, a correction amount of the reference value according to the load amount is obtained in advance, and the correction unit corrects the reference value itself according to the load amount detected by the load amount detection unit. The eccentricity determining unit determines whether the vibration amplitude falls within a predetermined range during the dehydrating operation by determining whether the detected eccentricity is less than the corrected reference value. .

In the centrifugal dehydrator according to any of the first and second aspects of the invention, the rotation control means rotates the drum at a high speed when the eccentricity determining means determines that the eccentricity is less than the reference value. To perform the dehydration operation. Accordingly, both the detection deviation of the eccentric amount depending on the load amount at the time of detecting the eccentric amount and the difference in the vibration suppression effect depending on the load amount during the spin-drying operation are eliminated at the same time, without depending on the load amount. During the spin-drying operation, the vibration amplitude is kept within a predetermined range. Therefore, occurrence of abnormal vibration and abnormal noise during the dehydration operation can be reliably prevented.

Since the determination of the amount of eccentricity for shifting to the dehydrating operation is appropriately performed in accordance with the load, the amount of eccentricity may be within the predetermined range during the dehydrating operation. There is no danger of being determined to be greater than or equal to the reference value.
For this reason, it is possible to prevent the balance adjustment before shifting to the spin-drying operation from being undesirably prolonged, so that the spin-drying time and the washing time can be reduced.

In the centrifugal dewatering device, when it is determined that the amount of eccentricity is equal to or larger than the reference value, it is possible to determine that if the operation proceeds to the dewatering operation as it is, there is a high possibility that the vibration is too large. The rotational speed of the drum is reduced to a rotational speed at which stirring is performed, thereby eliminating the eccentric load. Therefore, the balance of the laundry in the drum can be quickly adjusted, and the operation can be shifted to the dehydration operation in a short time.

Generally, since the centrifugal dehydrator is integrated with a washing machine, a predetermined amount of water is poured into a drum containing laundry at the start of washing, and the drum is rotated to wash the laundry. If the water level in the drum is detected by the water level detecting means after sufficient water is contained, and the load amount is detected based on the decrease in the water level, the amount of laundry can be easily detected.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the centrifugal dehydrator according to the first and second inventions will be described below with reference to the drawings. First, the structure of one embodiment of a drum type washing machine provided with a centrifugal dewatering device according to the first and second inventions will be described with reference to FIGS.
FIG. 1 is a side sectional view of the washing machine, and FIG. 2 is a rear perspective view of the washing machine.

An outer tub 32 is suspended by a spring 34 and a damper 36 inside the outer box 30, and a drum 38 for containing laundry is supported by a main shaft 44 inside the outer tub 32.
Numerous water holes 40 are provided in the peripheral wall of the drum 38, and water supplied to the outer tub 32 flows into the drum 38 through the water holes 40, and conversely, The water dehydrated from the water is scattered to the outer tub 32 through the water passage hole 40. A baffle 42 is provided at an appropriate location on the inner periphery of the drum 38 for scraping up the laundry as it rotates. A door 46 for opening and closing the front opening of the outer tub 32 is provided on the front surface of the outer box 30, and the laundry is stored inside the drum 38 by opening the door 46.

The main shaft 44 has a bearing 48 mounted on the outer tub 32.
, And a main pulley 50 is attached to the tip. A motor 52 is disposed on the lower surface of the outer tub 32, and the rotational driving force of the motor 52 is a motor pulley 54,
The power is transmitted to the main pulley 50 via the V-belt 56. In addition, water supplied to the water supply port 58 from an external tap, etc.
Water is injected into the outer tank 32 through the water supply valve 60. On the other hand, the water accumulated in the outer tub 32 is discharged outside through a drain port 64 opened and closed by a drain valve 62. An opening is provided on the ring portion of the main pulley 50 at one location on the circumference, and a light emitting unit 66 and a light receiving unit 68 are arranged on both sides of the ring portion. As a result, the light emitted from the light emitting section 66 only once during the rotation of the drum 38 reaches the light receiving section 68 through the opening. A rotation sensor described later outputs a detection signal (rotation marker) synchronized with the rotation of the drum 38 based on the light receiving signal. Drum 3
The rotation ratio between the motor 8 and the motor 52 is determined by the ratio of the diameters of the main pulley 50 and the motor pulley 54. For example, the rotation of the motor 52 is transmitted to the drum 38 at a reduced speed of about 1/3.

Next, an electrical configuration of a portion related to centrifugal dehydration in the washing machine will be described with reference to FIG. The control unit 10 mainly composed of a microcomputer includes a central control unit 11, a phase control unit 12, an eccentric load detection unit 13, and a load amount detection unit 14. The central control unit 11 includes a memory in which an operation program for performing the dehydration operation is stored in advance, receives information on the eccentric load and information on the load amount from the eccentric load detection unit 13 and the load amount detection unit 14, respectively, and And an instruction signal Np of the target rotation speed of the motor 52 corresponding to the desired drum rotation speed.
Is given to the phase control unit 12. The motor drive unit 20 includes an AC power supply 201 and a switch unit 202, and functions as a rotation speed control unit of the motor 52 together with the phase control unit 12. The rotation speed detector 22 is attached to the motor 52,
A detection signal Nr (for example, a pulse signal of a number corresponding to the rotation) reflecting the actual rotation speed is fed back to the phase control unit 12.

Next, the operation of the rotation control of the motor 52 centering on the phase control unit 12 and the motor drive unit 20 will be described with reference to FIG.
It will be described in detail with reference to FIG. The phase control unit 12 calculates a control angle α based on a difference between the target rotation speed instruction signal Np and the detection signal Nr, and inputs the control angle α to the switch unit 202. The switch unit 202 is composed of a gate-controlled semiconductor switch such as a triac, and a sine-wave single-phase AC current as shown in FIG. The switch unit 202 generates a pulse signal at a position delayed by the control angle α from the reference position at a phase angle of 0 ° as shown in FIG. The gate control type semiconductor switch is turned on / off so as to allow the current to pass during the phase cutoff and the phase angle α to 180 degrees. As a result, an intermittent current in a range shown by hatching in FIG. 4C is supplied to the motor 52 as a drive current. In other words, the larger the area of the hatched area is,
2 is large, and the rotational torque of the motor 52 is high. Therefore, the phase control unit 12
2 is accelerated, the control angle α is reduced, and conversely, when it is decelerated, the control angle α is increased.

The current detecting section 21 extracts a fluctuation component of the driving current flowing through the motor 52 near the drum rotation speed, converts the extracted component into a voltage value, and supplies the voltage value to the eccentric load detecting section 13. That is,
The drive current includes a fluctuation component depending on the power supply frequency as shown in FIG. 4C and a fluctuation component due to a factor of the motor 52 itself (for example, friction between the motor shaft and the bearing). By doing so, such unwanted components are removed. FIG. 5 is a diagram illustrating an example of a drive current fluctuation component obtained as a result of such processing. In the figure, a rotation marker M is a marker based on a signal indicating one rotation cycle of the drum 38 obtained by the rotation sensor 23. If an eccentric load exists on the drum 38, the motor 52
, The drive current has a fluctuation component corresponding to the eccentric load, as shown in FIG. The peak of the fluctuation component appears when the load torque is maximized within one rotation period of the drum 38, that is, when the eccentric load is to be lifted upward against the gravity, and the fluctuation amplitude L is It corresponds to the magnitude of the eccentric load.

The eccentric load detecting unit 13 receives the signal of the fluctuation component of the driving current as shown in FIG. 5 and outputs the maximum peak and the minimum peak at every interval of the rotation marker M, that is, every one rotation period of the drum 38. Is detected. Then, the difference (fluctuation amplitude L) between the maximum and minimum peaks is calculated. The internal memory stores the correspondence between the fluctuation amplitude L and the amount of eccentricity, which is checked in advance through experiments or the like. Accordingly, the amount of eccentricity can be obtained from the fluctuation amplitude L with reference to this correspondence. Further, based on the timing at which the maximum peak appears (for example, the delay time from the immediately preceding rotation marker M), the drum 3
Eight eccentric positions on the inner peripheral wall surface can be detected.

The inventors of the present application have found that the fluctuation component of the drive current generated when the rotation control of the motor 52 is performed as described above does not accurately reflect the absolute amount of the eccentricity. The result of the experiment was found. Hereinafter, the experimental method and the result will be described. First, as shown in FIG.
N which looks like laundry almost uniformly along the inner peripheral wall of No. 8
(Kg) weight 381 is attached. For example, if an 8 kg weight is attached as shown in FIG. 6, it can be considered that the laundry having a load of 8 kg is uniformly distributed on the inner peripheral wall surface of the drum 38. To this uniform weight 381, an M (kg) weight 382 is attached to a part of the drum 38 as an eccentric load. The weight N (kg) of the load weight 381 and the weight M (kg) of the eccentric load weight 382
And the relationship between the weight M (kg) and the fluctuation amplitude L of the drive current, and the relationship between the weight M (kg) and the vibration amplitude of the outer box 30 during spin-drying were measured.

The inner diameter of the drum 38 is 470 mm,
8 at 130 rpm, the weight M (k
g) That is, FIG. 8A shows the measurement result of the relationship between the eccentricity and the fluctuation amplitude of the drive current. It is clear from FIG. 8A that even with the same amount of eccentricity, the smaller the load amount, the larger the fluctuation amplitude. Even with the same increase in the eccentric amount, the smaller the load amount, the larger the fluctuation amplitude. It will be noticeable. This is considered to be due to the following reasons.

That is, even with the same amount of eccentricity, the ratio of the amount of eccentricity to the weight of the entire weight inside the drum 38 decreases as the load increases. For example, when the load is 4 kg and the eccentricity is 1 kg, the eccentricity accounts for 20% of the whole.
When the load is 16 kg and the eccentricity is 1 kg, the eccentricity is only about 6%. When the eccentric load rotates with the rotation of the drum 38 and the eccentric load is to be lifted above the drum 38, the gravity acting on the eccentric load is, as shown in FIG. Acts in the opposite direction to the rotation of the drum 38, so that the rotation speed of the drum 38 is reduced. On the other hand, when the eccentric load passes through the highest position of the drum 38 and is going to be lowered, the gravity acting on the eccentric load is in the same direction as the rotation of the drum 38 as shown in FIG. As a result, the rotation speed of the drum 38 is increased. The drive current fluctuates so as to keep the speed change caused by such load fluctuation constant, but when the load amount is large, a large torque is required to rotate the load, and a relatively large drive current is required. Need to shed. For this reason, the fluctuation of the torque due to the eccentric load becomes relatively small, and the fluctuation of the driving current is not remarkable.

On the other hand, when the rotational speed of the drum 38 is 970 rpm
FIG. 8B shows the measurement results of the relationship between the eccentricity and the vibration amplitude of the outer case 30 when m is set. What is clear from FIG. 8B is that even with the same eccentricity, the larger the load, the more the vibration is suppressed. That is, when a certain constant vibration amplitude is allowed during the spin-drying operation, a larger eccentric amount can be allowed as the load amount increases. For example, assuming that a vibration amplitude of 1 mm is allowed during the dehydration operation, 4
With a load of kg, an eccentricity of 0.6 kg is the maximum allowable value, whereas with a load of 16 kg, an eccentricity of 1.2 to 1.3 kg, which is twice or more, can be tolerated. this is,
It is considered that the larger the load amount, the greater the flywheel effect and the greater the weight of the outer tub 32, thereby suppressing vibration.

Here, if the inclination of the straight line at each load amount is the same or almost the same in FIGS. 8A and 8B, there is no need to perform the correction as described later. because,
In that case, the detection deviation of the eccentricity amount depending on the load amount with respect to a certain value of the fluctuation amplitude of the drive current (the difference in the horizontal axis direction of the straight line with respect to two kinds of load amounts in FIG. 8A) And the difference in the vibration suppression effect depending on the load amount (the difference in the horizontal axis direction of the straight line with respect to certain two types of load amounts in FIG. 8B) is canceled out.
This is because the effect of the load amount does not appear at all. However, the relationship between FIGS. 8 (a) and 8 (b)
Friction between main shaft 44 and bearing 48, spring 34 and damper 36
Because it depends on many structural parameters, such as elasticity, it is practically impossible to design the above state. Therefore, in the centrifugal dehydrator according to the present invention, by simultaneously electrically correcting the detection deviation of the eccentric amount and the difference in the vibration suppression effect as described above, regardless of the load amount, the vibration amplitude during the dehydration operation can be increased. Is set to a certain value.

First, the processing procedure of the embodiment of the centrifugal dehydrator according to the first invention will be described with reference to the flowcharts of FIGS. 9 and 10. In the following description, a numerical value when the diameter of the drum is set to 470 mm is taken as an example, but it is possible to cope with a case where the drum diameter is different by appropriately changing the numerical value of each rotation speed. It is obvious.

First, although not shown in FIG. 9, the amount of laundry (load amount) is detected in the following procedure before the washing step of washing. That is, after the dry laundry is stored in the drum 38, a predetermined amount of water is poured into the outer tub 32. Next, the drum 38 is rotated at a rotation speed during the washing process (for example, about 55 rpm) for a predetermined time and then temporarily stopped. Since the dried laundry absorbs water when the drum 38 rotates, the water level in the outer tub 32 decreases by the amount of the absorbed laundry. When the amount of laundry is large, the water level drop is large. Therefore, the load amount detection unit 14 detects the water level drop amount by a water level sensor attached to the outer tub 32, and determines the load amount based on the detected amount. . The load amount can be used for controlling the amount of water injected during the washing step, for example, in addition to the dehydration step.

When the dewatering process is started, the laundry in the drum 38 is piled up on the bottom of the drum 38. When the start of the dehydration process is instructed by the user from the operation unit 24, the motor 52 is started and the eccentric load detection rotation is executed (step S1). At this time, the drum 38 rotates in one direction at a rotation speed N1 (for example, about 130 rpm) that is faster than the rotation speed at which the centrifugal force acting on the laundry and the gravity balance, but lower than the rotation speed at which resonance occurs (about 200 rpm). Is done.

By the above rotation, all the laundry rotates while being pressed against the inner peripheral wall of the drum 38 by centrifugal force. When the laundry is unevenly distributed on the inner peripheral wall surface of the drum 38, the driving current of the motor varies as shown in FIG. Therefore, the eccentric load detection unit 13 detects the fluctuation amplitude L of the drive current as described above (Step S2).
Then, the eccentricity X is calculated based on the predetermined relationship between the fluctuation amplitude L and the eccentricity (step S3). Here, a straight line with a load amount of 4 kg in FIG. 8A is used as the correspondence between the fluctuation amplitude L of the drive current and the eccentric amount X. Therefore, for example, if the index value corresponding to the fluctuation amplitude L is 15, the eccentric amount X is obtained as 600 g. However,
As described above, the eccentric amount X obtained here does not accurately reflect the absolute eccentric amount due to the uneven distribution of the laundry.
Therefore, the eccentricity is corrected as follows.

For example, in FIG.
Comparing the amount of eccentricity with respect to the same fluctuation amplitude when the load is 16 kg and when the load is 16 kg, about 3.
It has tripled. In other words, when the load amount is 16 kg, even if the same fluctuation amplitude appears when the load amount is 4 kg,
The actual amount of eccentricity is as large as 3.3 times. On the other hand, in FIG. 8B, when comparing the eccentricity for the same vibration amplitude when the load is 4 kg and 16 kg, the eccentricity is about 2.1 times when the load is 16 kg. That is, when the load amount is 16 kg, even when the eccentric amount is 2.1 times larger than that when the load amount is 4 kg, only the same vibration is generated during the spinning rotation.

Therefore, when a certain vibration amplitude is allowed during the spinning operation, a value obtained by multiplying the eccentricity X obtained from the fluctuation amplitude of the current by 3.3 / 2.1 = 1.57 is used as the load amount. This is a converted value for a load of 4 kg, which cancels out the dependent deviation of the eccentricity and the effect of suppressing vibration. For example, as described above, the fluctuation amplitude index value is 15 and the eccentricity X is 600
g, when the load is 4 kg, the actual eccentricity is also 600 g, but when the load is 16 kg, the actual eccentricity is 2000 g, and the eccentricity corrected as described above is obtained. The core weight is 940 g.

Since it is necessary to correct the eccentricity X according to the load as described above, the load coefficient and the correction coefficient C are determined based on the previously measured correspondence between FIGS. 8A and 8B. Define the relationship. In this embodiment, the load amount is divided into four stages according to the ratio to the rated load amount as described below, and an appropriate correction coefficient C is determined for each division.

First, the central control unit 11 determines whether the load is 80% or more of the rated load (step S).
4) If it is determined that the load amount is 80% or more, the correction coefficient C is set to 1.5 (step S7). Step S
If it is determined in Step 4 that the load is less than 80%, it is determined whether the load is 60% or more of the rated load (Step S5), and the load is 60% or more (that is, 60%). (Less than 80%), the correction coefficient C is set to 1.3.
(Step S8). If it is determined in step S5 that the load is less than 60%, it is determined whether the load is 40% or more of the rated load (step S5).
6) If it is determined that the load amount is 40% or more (that is, 40% or more and less than 60%), the correction coefficient C is set to 1.1 (step S9). 40% load in step S6
If it is determined that the difference is less than 1, the correction coefficient C is set to 1.0 (step S10).

After setting the correction coefficient C as described above,
The correction amount C1 is calculated by multiplying the correction amount C by the correction amount C (step S11). Then, the correction eccentric amount X1
Is smaller than a predetermined reference value A (step S12). The reference value A is predetermined in accordance with an allowable vibration amplitude of the outer case 30 during the spinning operation. For example, when it is desired to suppress the vibration amplitude to about 1.2 mm or less, FIG.
From the straight line with a load of 4 kg in (b), the reference value A is 750 g.
It is determined.

If it is determined in step S12 that the corrected eccentric amount X1 is smaller than the predetermined reference value A, the flow advances to step S14 to increase the rotation speed of the drum 38 to a predetermined high rotation speed N2. The high-speed rotation speed N2 can be set to about 1000 rpm. However, in order to protect the laundry which is liable to damage the cloth, a washing course specified by the user (for example, a blanket washing course, a clothes washing course exclusively for drying, etc.). It is preferable to limit to the upper limit value according to. When the drum 38 is rotated at such a high rotation speed, the water that has soaked into the laundry exudes and scatters. Then, when a predetermined time elapses, the rotation of the drum 38 is stopped, and the dewatering process ends.

If it is determined in step S12 that the corrected eccentric amount X1 is equal to or larger than the predetermined reference value A, it can be determined that the vibration amplitude during the spinning rotation is likely to exceed the allowable value. Then, the process proceeds to step S13, and the laundry is loosened.

FIG. 10 is a flowchart showing the rotation control during the loosening operation in step S13. When the loosening operation is performed, a large number of laundry items are often entangled with each other and are hardly peeled off. Therefore, first, the rotation of the drum 38 is temporarily stopped or reduced to the extent that it is almost stopped (step S21). Next, the drum 38
Is rotated leftward at a rotation speed during the washing process (for example, about 55 rpm) (step S22), and then the rotation direction is reversed to rotate the drum 38 rightward at the same rotation speed (step S23). Then, the left-right reversal is repeated until a predetermined time elapses (step S24), and the loosening operation ends. As a result, the laundry is stirred inside the drum 38, so that the tangled laundry is loosened,
Each piece of laundry is easily separated from each other. Therefore, when returning to step S1 and the rotation speed of the drum 38 is increased to the rotation speed N1, the loosened laundry is
8, it is easy to disperse evenly on the inner peripheral wall surface, and the possibility that the eccentric amount becomes small increases.

Next, the processing procedure of the embodiment of the centrifugal dehydrator according to the second invention will be described with reference to the flowchart of FIG. In the above embodiment, the eccentricity X obtained from the fluctuation amplitude of the current is corrected, and the reference value A, which is the reference for comparison, is fixed. On the other hand, in the present embodiment, the eccentricity X obtained from the fluctuation amplitude of the current is fixed, and the reference value A is corrected so that the influence of the load is offset.

That is, step S is performed in the same manner as in the above embodiment.
After calculating the amount of eccentricity X in 3, the load amount becomes 8 of the rated load amount.
It is determined whether it is 0% or more (step S4). If it is determined that the load amount is 80% or more, the correction coefficient D is set to 0.
It is set to 67 (step S37). If it is determined in step S4 that the load is less than 80%, it is determined whether the load is 60% or more of the rated load (step S5), and if the load is 60% or more. When it is determined, the correction coefficient D is set to 0.77 (step S38). If it is determined in step S5 that the load is less than 60%, it is determined whether the load is 40% or more of the rated load (step S6), and if the load is 40% or more. If determined, the correction coefficient D is set to 0.9 (step S
39). If it is determined in step S6 that the load is less than 40%, the correction coefficient D is set to 1.0 (step S40). As is already clear, since the eccentricity and the reference value are in a relative relationship, the correction coefficient D is the reciprocal of the correction coefficient C of the previous embodiment.

After the correction coefficient D is determined as described above,
As in the above embodiment, the correction reference value A1 is calculated by multiplying the reference value A obtained from FIG. 8B by the correction coefficient D (step S41). For example, when it is desired to suppress the vibration amplitude to about 1.2 mm or less, the reference value A is set to 750 g, and when the correction coefficient D is set to 0.77, the correction reference value A1 becomes 5
80 g. Then, it is determined whether or not the eccentricity amount X is smaller than the correction reference value A1 (step S42).
Is increased to a predetermined high-speed rotation speed N2 to perform dehydration.

As described above, the above two embodiments are different only in that the eccentricity for comparing the magnitude relation or the reference value is corrected in accordance with the load. This achieves the same purpose of canceling out the effect of suppressing the detection deviation of the eccentric amount and the vibration.

The above embodiment is merely an example, and it is apparent that changes and modifications can be made within the spirit of the present invention. Although the above embodiment has been described with reference to a drum-type washing machine, it is apparent that the present invention is also applicable to a dry cleaner using a petroleum-based solvent or the like.

[Brief description of the drawings]

FIG. 1 is a side sectional view of a drum type washing machine having a centrifugal dehydrator according to an embodiment of the present invention.

FIG. 2 is a rear perspective view of the drum type washing machine of FIG. 1;

FIG. 3 is an electrical configuration diagram of the centrifugal dehydrator of the present embodiment.

FIG. 4 is a waveform chart for explaining a rotation control operation of a motor in the centrifugal dehydrator of the present embodiment.

FIG. 5 is a waveform chart showing an example of a change in motor drive current due to the influence of an eccentric load.

FIG. 6 is a schematic diagram of the internal structure of a drum for examining the effect of a load amount on eccentricity detection.

FIG. 7 is a schematic diagram showing a rotation state of a drum when an eccentric load exists.

FIG. 8A is a diagram showing the correspondence between the amount of eccentricity and the fluctuation amplitude of the drive current of the motor, and FIG. 8B is a diagram showing the correspondence between the amount of eccentricity and the vibration amplitude of the outer box during spin-drying.

FIG. 9 is a flowchart showing a control operation at the time of a dehydration operation in the embodiment of the centrifugal dehydrator of the first invention.

FIG. 10 is a flowchart showing a control operation at the time of a dehydration operation in the embodiment of the centrifugal dehydrator of the first invention.

FIG. 11 is a flowchart showing a control operation at the time of a dehydration operation in the embodiment of the centrifugal dehydrator of the second invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 ... Control part 11 ... Central control part 12 ... Phase control part 13 ... Eccentric load detection part 14 ... Load amount detection part 20 ... Motor drive part 201 ... AC power supply 202 ... Switch part 21 ... Current detection part 22 ... Rotation speed detection Container 23 ... Rotation sensor 30 ... Outer box 32 ... Outer tub 38 ... Drum 52 ... Motor

Continuation of front page (58) Field surveyed (Int.Cl. ⁷ , DB name) D06F 25/00-37/42 D06F 49/00-49/06

Claims (5)

(57) [Claims] 1. A centrifugal dewatering device for storing laundry in a basket-shaped drum and rotating the drum about a horizontal axis to dehydrate the laundry. Load amount detecting means for determining the amount; b) eccentric amount detecting means for detecting an eccentric amount which is the magnitude of the eccentric load of the drum; c) detecting the eccentric amount with the eccentric amount detecting means. In consideration of the deviation of the detection due to the difference in the amount of laundry at the time, and the effect of suppressing the vibration due to the weight of the laundry when the drum is rotated at high speed, the drum is operated at a high speed even if the amount of the laundry is different. Correction means for correcting the amount of eccentricity detected by the eccentric load detection means according to the amount of laundry detected by the load amount detection means so that the amount of vibration when rotated is substantially the same. D) whether the amount of eccentricity corrected by the correction means is equal to or larger than a predetermined reference value An eccentricity amount determining means for determining whether or not the motor is rotatively driven to rotate the drum at a high speed when the eccentricity amount determining means determines that the eccentricity amount is less than a reference value; A centrifugal dewatering device, comprising: 2. A centrifugal dehydrator for storing laundry in a basket-shaped drum and rotating the drum about a horizontal axis to dehydrate the laundry, comprising: a) removing the laundry stored in the drum; Load amount detecting means for judging the amount; b) eccentric amount detecting means for detecting an eccentric amount which is the magnitude of the eccentric load of the drum; c) detecting the eccentric amount with the eccentric amount detecting means. In consideration of the deviation of the detection due to the difference in the amount of laundry at the time, and the effect of suppressing the vibration due to the weight of the laundry when the drum is rotated at high speed, the drum is operated at a high speed even if the amount of the laundry is different. Correction means for correcting a reference value for determining the amount of eccentricity according to the amount of laundry detected by the load amount detection means so that the amount of vibration when rotated is the same, d. The eccentricity detected by the eccentricity detecting means is corrected by the correcting means. Eccentricity amount determining means for determining whether or not the eccentricity amount is equal to or greater than the reference value, and e) when the eccentricity amount is determined to be less than the reference value by the eccentricity amount determining means, to rotate the drum at a high speed. A centrifugal dehydrator, comprising: a rotation control unit that controls a motor that rotationally drives the drum. 3. The rotation control means controls a motor to rotate the drum at a rotation speed such that the laundry sticks to the inner wall surface of the drum by centrifugal force and rotates, and at this time, the eccentricity detection means 3. The centrifugal dewatering apparatus according to claim 1, wherein the eccentricity is obtained based on a fluctuation component of a motor drive current accompanying rotation. 4. The apparatus according to claim 1, wherein the rotation control means rotates the drum at a low speed in order to loosen and disperse the laundry when the eccentricity determination means determines that the eccentricity is equal to or greater than a reference value. The centrifugal dehydrator according to claim 1 or 2, wherein 5. The load amount detecting means injects a predetermined amount of water into a drum in which laundry is stored, detects the water level in the drum after the laundry is impregnated with water, and lowers the water level due to water absorption. The centrifugal dehydrator according to claim 1 or 2, wherein the amount of the laundry is determined according to the following.