JP3249474B2 - Drum type 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 drum type centrifugal dehydrator for storing laundry in a basket-shaped drum and rotating the drum at a high speed about a horizontal axis to perform dehydration. Here, the dehydration includes the dewatering in washing using a petroleum-based solvent or the like.

[0002]

2. Description of the Related Art A drum-type centrifugal dehydrator rotates a cylindrical basket-shaped drum containing wet laundry at a high speed around a horizontal axis to scatter and remove water contained in the laundry. Configuration. One of the major problems with such a centrifugal dehydrator is that when the drum is rotated at high speed in a state where the laundry is unevenly distributed on the inner peripheral wall of the drum, abnormal vibration occurs due to imbalance in the mass distribution around the rotation axis. Or abnormal noise.

On the other hand, the applicant of the present application has proposed a centrifugal dewatering device for the purpose of uniformly dispersing laundry on the inner periphery of a drum in a short time in the invention described in Japanese Patent Application Laid-Open No. 9-290089. . In this novel centrifugal dehydrator, the laundry is attached to the inner peripheral wall of the drum and rotated by rotating the drum at a rotational speed at which the centrifugal force acting on the laundry in the drum is slightly greater than the gravity. To do. In this state, the eccentric load caused by the uneven distribution of the laundry is detected, and when the eccentric amount is larger than a predetermined allowable value, when it is detected that the eccentric load has reached the vicinity of the upper portion of the drum, the load of the drum is detected. The rotation is quickly dropped for a short time to reduce the centrifugal force acting on the laundry, causing the laundry to drop. Then, the lump of laundry that caused the eccentric load is appropriately displaced and rearranged, and the eccentric amount of the entire drum is reduced.

[0004] Further, the centrifugal dehydrator is configured to perform the above-described balance adjustment operation in a state where water is accumulated at the bottom of the drum. According to this, when the laundry passes through the bottom of the drum, it absorbs water, and the laundry always contains a sufficient amount of water. For this reason, even for laundry, such as futons or blankets, which expand when a certain amount of water escapes and occupy the space in the drum, it is possible to appropriately disperse the laundry while keeping its volume small. it can.

[0005]

When the balance adjustment operation is performed in a state where water is accumulated at the bottom of the drum as described above, if the amount of water is too large, the water becomes a load for rotating the drum. Eccentric load cannot be measured. On the other hand, if the amount of water is too small, there is a possibility that proper balance adjustment may not be performed as described below.

[0006] There are two types of laundry: water is difficult to drain (dewatering is difficult), and conversely, water is easy to drain (dewatering is easy), depending on the type of fiber, the difference in weaving, and the thickness of the cloth. Generally, laundry that is easy to drain water loses weight at a considerable rate even when the drum is rotating at a relatively low rotation speed, and is light in weight. When such various types of laundry are mixed and stored in the drum, if the amount of water accumulated at the bottom of the drum is insufficient with respect to the amount of the laundry,
Some laundry absorbs water sufficiently, and some of the laundry cannot absorb water sufficiently, and conversely, water is drained by rotation.

Even if the balance is adjusted so that the amount of eccentricity is reduced in a state where the water absorption is unbalanced, the weight of the laundry that has sufficiently absorbed the water as the high-speed dehydration is started and the squeezing progresses. It is possible that the weight loss of laundry that does not absorb enough water does not decrease much. As a result, the amount of eccentricity is greatly increased from the point when the balance is adjusted with the progress of dehydration, and there is a possibility that vibrations may increase or noise may be generated.

SUMMARY OF THE INVENTION The present invention has been made to solve these problems, and an object of the present invention is to ensure that even when various types of laundry are mixed, abnormal vibration and noise during dehydration operation are generated. Another object of the present invention is to provide a drum-type centrifugal dehydrator that can be avoided.

[0009]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides an outer tub, a basket-like drum rotatably disposed around a horizontal axis in the outer tub, A drum type centrifugal dehydrator having a motor for rotating a main shaft that cantileverly supports the drum, comprising: a) load amount detecting means for detecting an amount of laundry stored in the drum ; and b) water at a bottom of the drum. Perform balance adjustment operation with
A water level determining means for determining a water level for balance adjustment according to the load amount ; andc) a water supply / drainage means for supplying or draining water so that the water level in the outer tank becomes the water level for balance adjustment before starting dehydration. D) operation control means for performing a balance adjustment operation such that an eccentric load is reduced while rotating the drum in a state in which an amount of water corresponding to the balance adjustment water level is stored in the outer tank. It is characterized by:

In the drum type centrifugal dehydrator according to the present invention, the operation control means includes a rotation control means for controlling a motor so that the drum rotates at a rotation speed at which centrifugal force acting on the laundry exceeds gravity. An eccentric load detecting means for detecting a magnitude of an eccentric load caused by the uneven distribution of the laundry when the laundry is being pressed against the inner peripheral wall surface of the drum by centrifugal force, and detected by the detecting means. A determining means for determining whether or not the magnitude of the eccentric load exceeds a predetermined value, wherein the balance adjusting operation is performed when it is determined that the magnitude of the eccentric load is greater than the predetermined value.

Further, the operation control means includes position detection means for detecting that the position where the eccentric load exists has reached near a predetermined rotation position. During the balance adjustment operation, the rotation control means is provided on the laundry. The motor is controlled so that the acting centrifugal force rotates the drum at a rotational speed superior to gravity, and the drum is briefly rotated to a rotational speed such that the centrifugal force becomes smaller than gravity in accordance with the output timing of the position detecting means. A configuration in which the motor is controlled to reduce the speed may be adopted.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the drum type centrifugal dehydrator according to the present invention, the water level determining means determines the water level so that the larger the load, the higher the water level for balance adjustment. Before the start of the dehydration step, the water supply / drainage means performs additional water supply or drainage so that the level of the water stored in the outer tub becomes the balance adjustment water level. For example, in the case of performing dehydration following washing and rinsing, since water used for washing and rinsing is stored in the outer tank, it is usually unnecessary to supply additional water, and drainage is performed until the water level drops to a predetermined level. Will be.

When the rotation control means controls the motor so that the drum rotates at a rotational speed at which the centrifugal force acting on the laundry exceeds gravity, the laundry rotates while being pressed against the inner peripheral wall surface of the drum. Since water corresponding to the water level for balance adjustment is accumulated in the drum, the laundry comes into contact with the water and absorbs the water when passing near the bottom of the drum. Since water is present to some extent so that each laundry can absorb water sufficiently, each laundry is almost always in a state of sufficiently containing water.

For this reason, even a large laundry such as a futon or a blanket has a relatively small volume, a large space around the drum rotation axis is secured, and the laundry is easily dispersed. In addition, because the balance is adjusted in a state that all the laundry contains sufficient water, the influence of the variation in weight loss of each laundry during the subsequent dehydration is reduced, and the eccentric load is increased as the dehydration proceeds. The increase can be suppressed.

[0015] In the balance adjustment operation, the position detecting means detects that the layered portion of the laundry has reached above the drum, and at that time, the rotation control means decelerates the drum for a short period of time. Is controlled, the centrifugal force acting on the laundry is weakened, and the laundry on the side near the drum rotation axis of the stacked laundry drops due to gravity. Thus, the laundry causing the eccentric load can be appropriately dispersed on the inner circumference of the drum. Also at this time, since the laundry has sufficiently absorbed water and has a small volume, a space in which the laundry falls is sufficiently secured in the center, so that the dispersion of the laundry is not hindered.

[0016]

According to the drum type centrifugal dewatering apparatus according to the present invention, the balance is adjusted so that the eccentric load of the entire drum is reduced in a state in which each of the laundry stored in the drum contains a sufficient amount of water. Driving is performed. Therefore, for example, even when laundry that is easily dehydrated and laundry that is not easily dewatered are mixed and stored in the drum, the eccentric load is reduced without being affected by the factor of the ease of dehydration. In this case, the influence of variations in weight loss can be relatively small. This reduces the possibility that the eccentric load becomes abnormally large as dehydration proceeds,
The occurrence of abnormal vibration and noise during dehydration can be further avoided than before.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A drum type washing machine provided with a centrifugal dehydrator according to one embodiment of the present invention will be described below with reference to FIGS.

FIG. 1 is a side sectional view showing the entire structure of the drum type washing machine. A cylindrical outer tub 2 is arranged inside the outer box 1, and a cylindrical drum 3 for storing laundry is supported by a main shaft 6 inside the outer tub 2. A door 17 for loading clothes is provided at the front opening of the drum 3 so as to be openable and closable, and a baffle 5 for scraping up laundry is mounted at an appropriate position on the inner peripheral wall of the drum 3. Further, a large number of water passage holes 4 are formed in the peripheral wall of the drum 3, and water supplied into the outer tub 2 at the time of washing and rinsing flows into the drum 3 through the water passage holes 4 and is centrifugally dehydrated. The water discharged from the laundry in the drum 3 is scattered to the outer tub 2 through the water holes 4.

The main shaft 6 is rotatably held by a bearing 7 mounted on the outer tub 2, and a main pulley 8 is attached to a tip of the main shaft 6. A motor 9 is installed at the bottom, and a motor pulley 10 is attached to a rotating shaft of the motor 9. The rotational power of the motor pulley 10 is transmitted to the main pulley 8 via a V-belt 11. Water for cleaning and rinsing is supplied to the outer tub 2 through a water supply port 12 opened and closed by a water supply valve 13. On the other hand, the water after washing and rinsing is discharged to the outside through a drain port 14 opened and closed by a drain valve 15. FIG.
Although not described, a hot water supply port for supplying hot water into the outer tub 2 is provided in parallel with the water supply port 12, so that washing can be performed using hot water.

The rotation sensor 16 is composed of a light-emitting unit installed on the rear wall of the outer tub 2 with the main pulley 8 interposed therebetween, and a light-receiving unit installed inside the rear wall of the outer box 1. The ring-shaped member of the main pulley 8 located between the light emitting unit and the light receiving unit is provided with one opening on the circumference, and is released from the light emitting unit only once during one rotation of the drum 3. The light passes through the opening and reaches the light receiving unit. The light receiving unit generates a later-described rotation pulse signal synchronized with the rotation of the drum 3 based on the light receiving signal.

FIG. 2 is a block diagram showing an electric system configuration of the drum type washing machine. A microcomputer (hereinafter, referred to as a “microcomputer”) 20 that controls the entire system includes a CPU 2.
4, an A / D converter 25, a RAM 26, a ROM 27, and the like. The ROM 27 stores an operation program for advancement of each washing process described later in advance. The microcomputer 20 includes an operation unit 30, a display unit 31, a valve driving unit 32, a water level sensor 33, an inverter control unit 34,
The motor current detector 35 and the like are connected. Operation unit 30
Comprises an operation panel provided on the front surface of the outer box 1, and outputs an input signal corresponding to an operation by a user to the microcomputer 20.
Give to. The display unit 31 also includes a display panel provided on the front surface of the outer box 1 and displays information corresponding to an operation and information related to a driving situation. The water level sensor 33 is attached to the outer tub 2 and detects the level of the water stored in the outer tub 2. Note that the water level is represented by, for example, the height from the bottom to the center of the outer tub 2 divided into ten equal parts.

The microcomputer 20 functionally includes a rotation speed control unit 21, an eccentric load measurement unit 22, and a load amount detection unit 23. The rotation speed control unit 21 sends a rotation speed instruction signal to the inverter control unit 34, and the inverter control unit 34 converts the instruction signal into a PWM signal and applies a drive voltage corresponding to the PWM signal to the motor 9. As a result, the motor 9 rotates at a desired rotation speed, and the drum 3 rotates at a reduced speed at a predetermined reduction ratio. Motor current detector 35
Detects the torque current component of the drive current supplied from the inverter control unit 34 to the motor 9.

Generally, when the laundry is unevenly distributed on the inner circumference of the drum 3, the load torque fluctuates during one rotation of the drum 3, so that the torque current component is changed according to the eccentric load caused by the uneven distribution of the laundry. fluctuate. FIG. 3 is a timing chart showing an example of the rotation pulse signal obtained by the rotation sensor 16 and the fluctuation of the torque current component due to the eccentric load. The maximum peak Vmax of the torque current component appears when the load torque becomes maximum within one rotation period of the drum 3. The load torque is maximized when the laundry, which causes the eccentric load, is lifted above the drum 3 against the gravity.
Therefore, normally, when the eccentric load exists in the angle range of about 90 ° on the near side from the highest position in the drum 3, the maximum peak Vm
ax appears. The position of the eccentric load on the inner circumference of the drum 3 is
The maximum peak Vmax (or the minimum peak Vmin) in the range of 0 to 360 ° with the rising of the rotation pulse as the reference 0 °.
Can be represented by the phase angle at which.

On the other hand, the fluctuation amplitude of the torque current component, that is, the difference between the maximum peak value and the minimum peak value (Vmax-Vmin) reflects the magnitude of the eccentric load (the amount of eccentricity). Therefore, the relationship between the amount of eccentricity and the fluctuation amplitude of the torque current component is checked in advance, and the determination criterion is determined in advance so that the magnitude relationship of the eccentricity as described later can be determined by the determination of the fluctuation amplitude. Keep it. During the dewatering process, the eccentric load measuring unit 22
3B receives the waveform shown in FIG. 3B from the motor current detector 35, detects the maximum peak Vmax and the minimum peak Vmin during one rotation period of the drum 3, respectively, and calculates the fluctuation amplitude from the difference between the two peaks. Then, it is determined whether or not the amount of eccentricity is equal to or less than an allowable value by comparing the fluctuation amplitude with the above-described determination criterion.

Next, the flow of the entire washing process in the drum type washing machine will be schematically described with reference to the flowchart of FIG. In the following description, the inner diameter of the drum 3 is 61
Although the numerical value of the rotation speed is shown for the case of 0 mm, when the inner diameter of the drum 3 is different, it is possible to cope by changing the numerical value appropriately.

When washing is started, water supply and hot water supply are performed up to a water level preset in the outer tub 2 (step S).
1). In addition, a detergent is supplied at an appropriate time during the process. After the end of the water supply / hot water supply, the drum 3 is rotated so that the laundry stored in the drum 3 is stirred (rotation speed 4).
Thus, the laundry is washed (step S2). When the predetermined cleaning operation time has elapsed, the drain valve 15 is opened, the rotation speed of the drum 3 is increased to about 200 rpm, and intermediate dehydration is performed for about 20 to 30 seconds (step S3). The rotation speed at the time of such intermediate dehydration is determined in consideration of that the vibration amplitude of the drum 3 and the outer tub 2 falls below a certain fixed value even if the laundry stored in the drum 3 is unevenly distributed. I have.

After the intermediate dehydration, a load amount detection process is performed to determine which of the three types of the amount of laundry (that is, the load amount) contained in the drum 3 belongs to the large, medium, and small categories. Further, the balance adjustment water level during the balance adjustment operation described later is determined according to the load amount (step S4). The details of the load amount detection processing will be described later.

Thereafter, water is supplied to the outer tub 2 in the same manner as in steps S1 and S2, and the first rinsing is performed by rotating the drum 3 (step S5). After the first rinse, an intermediate dehydration is performed,
The rinsing water seeping into the laundry is scattered (step S6). Further, a second rinsing is performed in the same manner (step S7). After that, before the final dehydration, a balance adjustment operation is performed to distribute the laundry on the inner circumference of the drum 3 so as to reduce the eccentric load (Step S8). As will be described in detail later, during this balance adjustment operation, drainage or water supply is controlled so that the water level in the drum 3 becomes the balance adjustment water level previously determined according to the load amount.

After the balance adjustment operation is completed, the rotation speed of the drum 3 is increased to about 200 rpm, and temporary dehydration is performed to disperse a part of the water seeping into the laundry (step S9). The diaphragm is lightly squeezed by this temporary dewatering, and thereafter the eccentric amount is measured, and the final dewatering rotation speed is determined based on the eccentric amount. Then, the final dehydration is executed by increasing the rotation speed of the drum 3 to the final dehydration rotation speed (step S10). The number of times of rinsing may be further increased.

Next, the load detection process in step S4 will be described in detail with reference to FIGS. FIG. 5 is a flowchart of the load amount detection process, and FIG. 6 is a timing chart for explaining the load amount determination operation.

In the drum-type washing machine of this embodiment, the rotation of the drum 3 is controlled so that the laundry is deviated in the drum 3 intentionally, and the load is determined by using an index value corresponding to the eccentricity generated at that time. Judge the quantity. At the start of the load amount detection processing, the laundry in the drum 3 is in a state of being slightly dehydrated by the intermediate dehydration immediately before.

First, the rotation speed controller 21 controls the rotation speed N1 (about 40 to 50 rpm) via the inverter controller 34 so that the centrifugal force acting on the laundry is smaller than gravity.
To control the rotation of the motor 9 to rotate the drum 3 (step S11). At this time, the laundry is scraped up by the baffle 5 and falls to the bottom, so that most of the laundry exists at the bottom of the drum 3.

After several seconds, the rotation speed control unit 21
Performs slow acceleration up to a rotation speed N2 (about 80 to 100 rpm) at which the centrifugal force acting on the laundry slightly exceeds gravity (step S12). As a result, the laundry is pressed against the inner peripheral wall of the drum 3 by centrifugal force,
As the drum 3 rotates, the drum 3 integrally rotates. When the amount of laundry is small, the laundry rolls on the inner periphery of the drum 3 due to slow acceleration, and the laundry is moderately scattered. However, when the amount of laundry is large, the laundry is difficult to roll and becomes a relatively large lump. 3 Stick to the inner wall. Therefore, a relatively large eccentric load is generated. At that time, the torque current component changes in synchronization with the rotation of the drum 3.

After maintaining the above rotation state for a while, the rotation speed control unit 21 determines that the rotation speed of the drum 3 is N3 (160 to 2).
(Approximately 00 rpm) (step S13), and immediately after that, the rotational speed is rapidly reduced to the rotational speed N2 (step S14). Since this rapid deceleration is performed by regenerative braking, a large regenerative current flows through the motor 9 during deceleration as shown in FIG. The load amount detecting unit 23 detects an amplitude value Vrg corresponding to the regenerative current from the torque current component detected by the motor current detecting unit 35 (Step S1).
5). As the amount of laundry is large and the generated eccentric load is large, a large regenerative current flows. By comparing the amplitude value Vrg of this regenerative current with a predetermined value, the load amount is large, medium or small. It is determined whether it belongs to the category (step S16). Further, the balance adjustment water level is set to a depth of 5 degrees, corresponding to a large, medium or small load, respectively.
It is determined three times (step S17). As described above, the load amount detection processing ends.

Note that the load amount detection method is not necessarily limited to the above method. For example, a predetermined amount of water may be supplied into the outer tub 2 at the beginning of the washing process, and at that time, a water level that is reduced due to the absorption of the laundry may be detected, and the load amount may be determined according to the reduced water level. .

Next, the balance adjustment operation and the dewatering process in steps S8 to S10 will be described in detail with reference to FIGS. 7 and 8 are flowcharts, and FIG. 9 is a schematic diagram showing the arrangement of the laundry in the drum.

When the second rinsing is completed, the rotation speed control unit 21 reversely rotates the drum 3 at a rotation speed of about 40 to 50 rpm, thereby loosening the laundry (step S20). Thereafter, the microcomputer 20 detects the water level in the outer tub 2 by the water level sensor 33, and determines whether or not the detected water level is equal to or higher than the previously determined balance adjustment water level (step S21). Normally, water having a water depth of 5 or more is used for rinsing, so that the detected water level should be equal to or higher than the balance adjustment water level. In that case (“Y” in step S21), the drain valve 15 is opened via the valve drive unit 32 (step S22). And
If the detected water level has reached the balance adjustment water level ("Y" in step S23), the drain valve 15 is closed (step S24).

On the other hand, if it is determined in step S21 that the detected water level is lower than the balance adjustment water level ("N" in step S20), the water supply valve 13 is opened via the valve drive unit 32 to supply water. Start (Step S2
5). When the detected water level reaches the balance adjustment water level (step S26), the water supply valve 13 is closed (step S27).

When an amount of water corresponding to the balance adjustment water level is stored in the outer tub 2 in this way, the amount of eccentricity due to uneven distribution of the laundry is measured (step S28). That is, the rotation speed control unit 21 uses the inverter control unit 34 to control the rotation speed such that the centrifugal force acting on the laundry slightly exceeds the gravity (for example, the rotation speed N2 = 80 to 100 rpm).
In step m), the motor 9 is controlled to rotate the drum 3 in one direction. When the drum 3 reaches the rotation speed, all the laundry rotates while being lightly pressed against the inner peripheral wall of the drum 3 by centrifugal force. At this time, since the water up to the balance adjustment water level is stored in the outer tub 2, the laundry that is attached to the inner peripheral wall of the drum 3 and rotates passes through the bottom of the drum 3 as shown in FIG. When you come in contact with water and absorb water.

As described above, since the balance adjustment water level is set at a height corresponding to the load amount, the laundry is irrespective of the thickness of the laundry stuck to the inner peripheral wall of the drum 3. It almost completely absorbs water. At this time, since the centrifugal force is not so large, the ratio of water discharged from the laundry to the outside during one rotation of the drum 3 is small. Therefore,
The laundry located anywhere on the inner circumference of the drum 3 rotates with a sufficient amount of water. For this reason, even a laundry such as a futon or a blanket, which easily expands when water absorption is small, keeps a relatively small volume.

In such a state, based on the torque current component detected by the motor current detection unit 35 as described above, the eccentric load measurement unit 22 determines that the amount of eccentricity occurring at that time is less than the allowable value. It is determined whether or not there is (step S29). This allowable value is set in advance in accordance with the amount of vibration (amplitude) that can be tolerated during high-speed spinning to be described later. In addition,
If the amount of water in the outer tub 2 is too large, the water becomes a load on the rotation of the drum 3 and it is difficult to accurately measure the eccentric load. However, since the water level is set appropriately as described above. Such an effect hardly occurs. In addition, since each laundry has sufficiently absorbed water, the amount of eccentricity is not determined to be equal to or less than the allowable value in a state where water is drained from some of the laundry. For this reason, the possibility of the increase of the eccentric amount accompanying the progress of dehydration can be reduced.

If it is determined in step S29 that the amount of eccentricity exceeds the allowable value, a balance adjustment operation is performed (step S30). In the balance adjustment operation, the rotation speed control unit 21 controls the motor 9 so that the rotation speed is maintained such that the laundry is lightly pressed against the inner peripheral wall of the drum 3 by the centrifugal force and rotates. Then, the fluctuation of the torque current component as shown in FIG. 3 (b) is monitored, and the drum 3 is decelerated for a very short time at a predetermined phase angle before the point of occurrence of the maximum peak Vmax. The rotation speed after deceleration is a rotation speed at which the gravity slightly exceeds the centrifugal force acting on the laundry.

When the rapid deceleration is performed as described above, FIG.
As shown in (b), when the laundry piled up on the inner wall surface of the drum 3 just causing the eccentric load reaches above the drum 3, the gravity exceeds the centrifugal force,
The laundry falls so as to be thrown out. At this time, since a larger centrifugal force is acting on the laundry located on the outer peripheral side, the drum 3 is decelerated by performing appropriate deceleration.
While the laundry on the inner peripheral wall side is rotated while being adhered to the surface, only the laundry on the rotating shaft side can be dropped. Since the volume of the laundry such as a futon or a blanket is relatively small as described above, a large space in the drum 3 is secured, and the laundry is easily dropped by the deceleration.

Appropriate parameters for such a fall (rotational speed before and after deceleration, deceleration time, etc.) can be determined in advance by experiments. Further, if the amount of laundry is different, the radius of rotation to the laundry located closest to the rotation axis in the drum 3 is different. Therefore, if the above parameters are modified according to the load, more appropriate dispersion can be achieved. Can be performed.

After the laundry is uniformly dispersed by such a balance adjustment operation, the rotational speed of the drum 3 is again maintained at N2, and the amount of eccentricity is measured again (step S3).
1) It is determined whether or not the eccentric amount at that time is equal to or less than an allowable value (step S32). If the amount of eccentricity exceeds the allowable value, it is determined whether or not the balance adjustment operation is the fifth time (step S33). Until the balance adjustment operation reaches the fifth time, the process returns to step S30 to perform the balance adjustment operation. Try. When the number of repetitions of the balance adjustment operation reaches five, it is determined that the balance adjustment is difficult, and the process proceeds to step S.
Proceed to 39.

If it is determined in step S29 or S32 that the amount of eccentricity is equal to or less than the allowable value, the drain valve 15 is opened (step S34). If the detected water level has dropped to 0 degrees, the rotation speed control is performed. The unit 21 controls the motor 9 so that the rotation speed of the drum 3 rotates at a predetermined rotation speed N4 (200 rpm). The rotation speed at this time is set so that a portion of the water contained in the laundry is scattered, that is, lightly squeezed (step S35).

After performing the temporary dehydration at the above rotation speed for 20 seconds, the rotation speed of the drum 3 is reduced again to N2 and the eccentric amount is measured (step S36). By the temporary dehydration, about 1/3 to 1/2 of the water contained in the laundry is discharged. Therefore, if the amount of eccentricity is small after the temporary dewatering, it can be estimated that imbalance is unlikely to occur even if the squeezing is performed more strongly thereafter. On the other hand, for example, when laundry having a significantly different water absorption rate is located at a distant position on the inner circumference of the drum 3, the amount of eccentricity may increase due to temporary dehydration. In such a case, if the strong dehydration is performed, the imbalance further progresses, and the vibration of the drum 3 may increase. Thus, the final spin speed is determined according to the eccentricity measured at this time (actually, the fluctuation amplitude of the torque current component) (step S37). For example, the maximum spin speed is 800 rpm and the minimum spin speed is 300 r.
pm, and the spin-drying speed is determined in the range of 800 to 300 rpm according to the amount of eccentricity. And the rotation speed control unit 2
1 controls the motor 6 so that the rotation speed of the drum 3 rises to this rotation speed (Step S38).

If it is determined in step S33 that the balance adjustment operation is the fifth time, the uniform dispersion of the laundry by the balance adjustment operation is abandoned, the drain valve 15 is opened (step S39), and the rotation of the drum is started. Speed 2
The speed is increased to 00 rpm (step S40). And
Regardless of whether the rotation speed of the drum 3 is increased in any of steps S38 and S39, the drum 3 is maintained at the rotation speed until the predetermined spin-drying time elapses (until “Y” in step S41). Do. Thereafter, the rotation speed of the drum 3 is reduced to about 40 to 50 rpm to perform reverse rotation, and the laundry is loosened (step S4).
2) End dehydration.

As described above, in the drum type washing machine of the present embodiment, final dehydration is performed at a rotation speed as high as possible within a range where vibration and noise do not occur due to the eccentric load. Therefore, without sacrificing dehydration performance,
Generation of vibration and noise can be avoided.

It should be noted that each numerical value in the above embodiment is an example, and the present invention is not limited to this. In the above embodiment, the centrifugal dehydrator using water has been described. However, it is apparent that the present invention can be applied to a dry cleaner using a petroleum-based solvent or the like. Further, the above-described embodiment is merely an example, and it is apparent that the embodiment can be appropriately modified and modified within the scope of the present invention.

[Brief description of the drawings]

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

FIG. 2 is a block diagram showing an electric configuration of the drum type washing machine.

FIG. 3 is a timing chart showing an example of a rotation pulse signal and a variation of a torque current component due to an eccentric load.

FIG. 4 is a flowchart of the entire washing process of the drum type washing machine.

FIG. 5 is a flowchart of a load amount detection process.

FIG. 6 is a timing chart for explaining a load amount determination operation.

FIG. 7 is a flowchart (part 1) of a balance adjustment operation and a dehydration process.

FIG. 8 is a flowchart of a balance adjustment operation and a dehydration process (part 2).

FIG. 9 is a schematic diagram showing an arrangement state of laundry in a drum.

[Explanation of symbols]

 2 ... Outer tank 3 ... Drum 9 ... Motor 12 ... Water supply valve 15 ... Drain valve 16 ... Rotation sensor 20 ... Microcomputer 21 ... Rotation speed control unit 22 ... Eccentric load measurement unit 23 ... Load amount detection unit 24 ... CPU 25 ... A / D converter 26 RAM 27 ROM 33 Water level sensor 34 Inverter controller 35 Motor current detector

Continuation of the front page (72) Inventor Masafumi Nishino 2-5-5 Keihanhondori, Moriguchi-shi, Osaka Sanyo Electric Co., Ltd. (56) References JP-A-9-290089 (JP, A) JP-A-4- 141192 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) D06F 23/00-25/00 D06F 33/02 D06F 49/00-49/04

Claims (3)

(57) [Claims] 1. A drum type having an outer tub, a basket-shaped drum disposed rotatably about a horizontal axis in the outer tub, and a motor for rotating and driving a main shaft for cantilevering the drum. In the centrifugal dehydrator, a) a load amount detecting means for detecting the amount of laundry stored in the drum , and b) a balance adjustment operation in a state where water is stored at the bottom of the drum.
The balancing water level for cormorants, a level determining means for determining in accordance with said load, c) prior to the start dehydration, plumbing means for performing the water supply or waste water, as the water level in the outer tub is balancing water level And d) operation control means for performing a balance adjustment operation such that the eccentric load is reduced while rotating the drum in a state where the amount of water corresponding to the balance adjustment water level is accumulated in the outer tank. Drum type centrifugal dehydrator characterized by the above-mentioned. 2. The operation control means includes: a rotation control means for controlling a motor such that a centrifugal force acting on the laundry exceeds a gravity at which the drum rotates at a rotational speed; Eccentric load detecting means for detecting the magnitude of the eccentric load caused by the uneven distribution of the laundry while being pressed against the wall surface, and the magnitude of the eccentric load detected by the detecting means exceeds a predetermined value. The centrifugal dewatering device according to claim 1, further comprising: a determination unit configured to determine whether or not the eccentric load is larger than a predetermined value. apparatus. 3. The operation control means includes position detection means for detecting that a position where an eccentric load exists has reached a position near a predetermined rotation position. During the balance adjustment operation, the rotation control means includes: The motor is controlled so that the drum rotates at a rotation speed at which the centrifugal force acting on
The drum type centrifugal dewatering apparatus according to claim 2, wherein a motor is controlled so as to reduce the drum for a short time to a rotation speed such that a centrifugal force becomes smaller than gravity according to an output timing of the position detecting means. .