JP3108350B2 - 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 basket-shaped drum for storing laundry such as clothes, and rotating the drum at a high speed about a horizontal axis to dehydrate the laundry or to remove a solvent for washing. The present invention relates to a centrifugal dehydrator for performing a liquid.

A drum-type centrifugal dehydrator has a structure in which laundry such as washed clothes is housed 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 peripheral wall of the drum, abnormalities occur due to imbalance in the mass distribution around the rotation axis. Vibration and abnormal noise are generated.

[0003] A centrifugal dehydrator for solving such a problem has been conventionally 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 inside the drum is evenly dispersed and arranged by low-speed rotation of the drum before performing a dehydration operation by high-speed rotation of the drum. More specifically, a two-stage rotation control is performed in which the drum is rotated at a low speed for a very short time, and then the drum is rotated at a rotation speed slightly higher than the rotation speed but sufficiently lower than the rotation speed during the spin-drying operation. The laundry is dispersed by combining them.

In this prior art, a vibration monitoring sensor is installed on a pedestal portion of the apparatus as means for detecting imbalance of laundry, and the rotational speed of a drum is increased to a high rotational speed for performing a dehydrating operation. When the vibration monitoring sensor detects an abnormal vibration when it is turned on, the rotation speed is reduced.

[0005]

However, even if the method for controlling the rotation of the drum as in the above-mentioned prior art is used, it is not always possible to surely and uniformly distribute the laundry by one low-speed rotation of the drum. If the drum is rotated at a high speed after trying to disperse the laundry by the low-speed rotation of the drum and abnormal vibration occurs, the dispersion must be executed again by the low-speed rotation. When the dispersion of the laundry by the low-speed rotation of the drum and the detection of the imbalance by the high-speed rotation of the drum are repeated a plurality of times, a problem arises that a long time is required for the dehydration process.

Further, when the drum is rotated so that the laundry is evenly dispersed as in the above-described prior art, particularly, a long-length garment is entangled while being located at the center of the drum, and a so-called tearing phenomenon occurs. May be caused. If the dehydration operation is continued in this state, the laundry may be torn.

The present applicant has proposed a centrifugal dehydrator for solving the above problem in Japanese Patent Application No. Hei 7-113628. In this new centrifugal dewatering device, a weight is added to a part of the inner peripheral wall so that the drum itself has an eccentric load, and the magnitude and position of the eccentric load including the eccentric load of the drum itself become predetermined. So that the laundry is rearranged.
As will be described in detail later, according to this device, the permissible range of the uneven load is widened when the laundry is dispersedly arranged, so that there is a great effect that the distributed arrangement becomes easy.

The present invention is a further improvement of the centrifugal dewatering apparatus according to the above-mentioned application, and an object of the present invention is to disperse and dispose laundry before dehydration operation so that abnormal vibration does not occur during dehydration operation. The present invention provides a centrifugal dewatering apparatus capable of performing efficient dewatering by performing the dehydration quickly and preventing the laundry from being torn due to a tearing phenomenon.

[0009]

According to a first aspect of the present invention, there is provided a centrifugal dehydrator for storing laundry such as clothes in a basket-shaped drum, and rotating the drum with a horizontal shaft. A centrifugal dewatering device for dewatering the laundry or dewatering the washing solvent by rotating about a) a) having an uneven load on a part of the inner peripheral wall, and the periphery of the position of the uneven load inward; A bulged cylindrical drum; b) a motor for rotating the drum; and c) detecting the magnitude and position of the eccentric load including the eccentric load of the laundry contained in the drum and the drum itself. Determining means for determining whether or not the magnitude of the unbalanced load is within a predetermined range and the position is near a position facing the unbalanced load of the drum itself by approximately 180 °; d) the drum itself From the state where the eccentric load of When the rotation speed of the drum is increased to a rotation speed at which the centrifugal force acting on the laundry exceeds gravity, and the magnitude and position of the eccentric load are determined to be as desired at the rotation speed Rotation speed control means for controlling the motor so as to rotate the drum at a rotation speed for performing a spin-drying or draining operation.

According to a second aspect of the present invention, there is provided a centrifugal dehydrator for storing laundry such as clothes in a basket-shaped drum and rotating the drum about a horizontal axis. A centrifugal dewatering device for dewatering the laundry or dewatering the washing solvent by: a) a cylinder having an uneven load on a part of the inner peripheral wall and having a rotational axis shifted in the direction of the position of the uneven load; A drum for rotating the drum; b) a motor for rotating the drum; and c) detecting the magnitude and position of the unbalanced load including the unbalanced load of the laundry contained in the drum and the drum itself. Determining means for determining whether or not the magnitude of the load is within a predetermined range and the position is in the vicinity of a position facing the eccentric load of the drum itself by approximately 180 °; d) the eccentric load of the drum itself is From the state facing the laundry, the laundry The rotational speed of the drum is increased to a rotational speed such that the centrifugal force to be used exceeds gravity, and when the magnitude and position of the unbalanced load are determined to be as desired at the rotational speed, dehydration or Rotation speed control means for controlling the motor so as to rotate the drum at a rotation speed for performing a liquid removing operation.

Further, in the centrifugal dehydrator according to the first or second aspect of the present invention, when the rotational speed control means determines that either the magnitude or position of the eccentric load is not as desired, Controlling the motor so as to temporarily stop or reduce the rotation speed of the drum to a rotation speed close to the stop, and then increase the rotation speed of the drum to a rotation speed for determining the unbalanced load again. Features.

It is preferable that the rotational speed for determining the unbalanced load by the determining means is slightly higher than the rotational speed at which the centrifugal force acting on the laundry inside the drum and gravity are balanced. .

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION The drum in the centrifugal dehydrator according to the first invention is subjected to an eccentric load by, for example, adding a weight to a part of the inner peripheral wall of the drum. The dehydration operation of rotating the drum at a high speed reduces the weight of the laundry but does not change the weight of the weight. Therefore, before the dehydrating operation, the laundry is dispersed and arranged around a position 180 ° opposite to the position of the weight so as to balance with the weight after the dehydrating operation. Therefore, the predetermined range, which is a criterion for judging the magnitude of the unbalanced load in the judgment means, takes into account the weight of the weight and the degree of reduction in the weight of the laundry due to the spin-drying operation, and takes into account the unevenness allowed after the spin-drying operation. It is preset based on the magnitude of the load, that is, an allowable range that does not cause abnormal vibration.

The judging means detects the magnitude of the eccentric load and the position on the inner peripheral wall of the drum based on, for example, the fluctuation of the motor current flowing when the motor is rotationally driven, and these are determined as described above. It is determined whether or not a desired state has been reached. The detection and determination of the unbalanced load can be performed when all the laundry in the drum is rotating while being pressed against the inner peripheral wall of the drum by centrifugal force.

When the drum is at first stopped, the laundry is solidified and stacked on the bottom of the drum by gravity. As the motor is started and the rotation of the drum gradually increases, centrifugal force starts to act on each laundry. Therefore, at the beginning of the rotation, the laundry lifted upward with the rotation of the drum falls downward during the rotation, but when the rotation speed increases, the laundry acts on the laundry stuck to the inner peripheral wall surface of the drum. The centrifugal force overcomes gravity and rotates with the drum without falling during rotation. However, with respect to laundry having the same rotation speed and the same weight, the centrifugal force acting at a position closer to the rotation axis of the drum is smaller, so that the laundry acts on the laundry located at a portion where the drum bulges inward. The resulting centrifugal force is smaller than the centrifugal force acting on the laundry located on the other inner peripheral wall surface of the drum.

Accordingly, there is a rotation speed at which the laundry located on the bulging portion falls during rotation, and the laundry located on the inner peripheral wall surface of the other drum sticks and rotates without falling. I do. As a result, the laundry is easily concentrated near the inner peripheral wall of the drum 180 ° opposite to the weight, and it is easy to keep the eccentric load within the desired range as described above.

In the centrifugal dehydrator according to the second aspect of the present invention, the rotating shaft of the cylindrical drum is formed so as to be shifted from the center of the circle. As a result, the distance from the horizontal rotation axis to the inner peripheral wall surface of the drum is not uniform, and a weight is added at the shortest position. Therefore, similarly to the centrifugal dehydrator according to the first aspect of the present invention, the laundry is less likely to be dispersed around the weight, and conversely, the laundry is more likely to concentrate near the inner peripheral wall of the drum 180 ° opposite the weight.

The above-described distributed arrangement of the laundry must be performed at a rotational speed at which the gravity exceeds the centrifugal force acting on some of the laundry. The centrifugal force acting on the laundry must also be performed at a rotational speed that exceeds the gravity. For this reason, in the unbalanced load determination, when the size and position are not as desired, the rotation speed of the drum is temporarily reduced to make all the laundry easy to move. Thereafter, the rotation speed is increased again to perform the dispersal arrangement of the laundry. As described above, in order to shorten the time required for re-executing the distributed arrangement of the laundry, it is preferable that the detection and determination of the unbalanced load be performed at a rotation speed as low as possible. The detection and determination of the unbalanced load is performed at a rotation speed slightly higher than the rotation speed at which the force and the gravity are balanced.

[0019]

【Example】

Embodiment 1 Hereinafter, an embodiment of a centrifugal dehydrator according to the first invention (hereinafter, referred to as “embodiment 1”) will be described with reference to the drawings. FIGS. 1A and 1B are views showing the structure of a drum type washing machine equipped with a centrifugal dehydrator according to the first invention, wherein FIG. 1A is an overall cross-sectional view, FIG. 1B is a plan view of a drum part, and FIG. FIG. 3 is a diagram illustrating an example of a fluctuation component of a motor current, FIG. 4 is a diagram illustrating an example of a relationship between a magnitude of an eccentric load and a fluctuation amplitude of a motor current, and FIG.
FIG. 6 is a schematic diagram for explaining a difference in an allowable load range depending on whether or not a weight is added to a drum, FIG. 6 is a flowchart for explaining a procedure of a dewatering process, and FIG. 7 is a diagram in the drum type washing machine of FIG. It is a schematic diagram which shows the movement situation of the laundry inside a drum.

First, the overall structure of the drum type washing machine will be described with reference to FIG. An outer tub 52 is arranged inside a frame 50 of the drum type washing machine, and a drum 54 for storing laundry is supported by a main shaft 64 and installed inside the outer tub 52. A water passage 56 is formed in the peripheral wall of the drum 54, and the washing water supplied into the outer tank 52 is supplied to the water passage 5.
The water dewatered from the laundry in the drum 54 through the drum 6 is discharged to the outer tub 52. On the inner peripheral wall of the drum 54, baffles 58 for scraping up the laundry with the rotation are installed at two positions at an interval of a rotation angle of 120 °. A weight 60 is attached at a position separated by a rotation angle of 120 ° from the baffle 58, and a plate member 59 is provided near the weight 60 on the inner peripheral side of the drum 54. The weight 60 causes the drum 54 itself to have an unbalanced load. The laundry is stored in the drum 54 from the laundry input port 62.

The main shaft 64 has a bearing 66 mounted on the outer tub 52.
The main pulley 68 is attached to the tip. A motor 22 for rotating and driving the drum 54 is disposed below the outer tub 52, and a motor pulley 72 is attached to a rotating shaft of the motor 22. The rotation of the motor pulley 72 is transmitted to the main pulley 68 through the V-belt 70. The washing water and the rinsing water are supplied from the outside to the outer tub 52 through the water supply port 74, and the amount of water is adjusted by the water supply valve 76. The water after washing and rinsing is discharged through a drain port 78 opened and closed by a drain valve 80. A drive voltage is applied to the motor 22 from the circuit unit 82. The circuit unit 82 includes a control unit 10 and an inverter control circuit 20 which will be described later. The rotation sensor
The light emitting unit 24a installed on the outer wall of the outer tub 52 with the main pulley 68 interposed therebetween and the light receiving unit 24 installed on the inner wall of the frame 50
b. An opening 6 is provided in the ring-shaped portion of the main pulley 68 located between the light emitting portion 24a and the light receiving portion 24b.
The light from the light emitting unit 24a passes through the opening 69 and reaches the light receiving unit 24b only once during one rotation period of the drum 54. Accordingly, the light receiving unit 24b of the rotation sensor generates a detection signal synchronized with the rotation of the drum 54, that is, a rotation marker.

Next, the electrical configuration and operation of the circuit section 82 will be described with reference to FIG. The control unit 10 mainly composed of a microcomputer is a central control unit 1
2. It comprises a rotation speed control unit 14, an unbalanced load determination unit 16 and a memory 18. The offset load determination unit 16 includes a peak value detection unit 161, a position determination unit 162, an amplitude calculation unit 163, an amplitude determination unit 164, and an AND gate 165. In addition to the control unit 10, the inverter control circuit 2
0, a rotation sensor 24 and a motor current detection circuit 26 are provided.

The memory 18 stores in advance an operation program for performing each of the washing, rinsing and dehydrating steps. When the operator performs a key operation from an operation unit (not shown) to select a dehydration mode, for example, a type of a fiber of the clothes to be dehydrated, and then instructs a start of a dehydration process, the central control unit 1
2 reads out the corresponding operation program from the memory 18 and advances the dehydration process by executing the operation program.

The rotation speed control unit 14 outputs a rotation speed designation signal including an instruction of the rotation direction of the drum 54 to the inverter control circuit 20 based on the operation program. The inverter control circuit 20 converts the rotation speed designation signal into a pulse width modulation (PWM) signal, and applies a drive voltage corresponding to the PWM signal to the motor 22. Therefore, the rotation speed control unit 1
4 and the inverter control circuit 20 function as a rotation speed control means.

The current flowing through the motor 22 is detected by a motor current detection circuit 26 and is input to the eccentric load determination unit 16. When the drum 54 has an uneven load, the motor current has a fluctuation component corresponding to the uneven load. FIG. 3 is an example of a waveform of the motor effective value current when there is an eccentric load. In the figure, the rotation marker is a signal indicating the cycle of one rotation of the drum 54, and is obtained based on the signal from the rotation sensor 24 as described above. As shown in FIG. 3, when there is an unbalanced load, the fluctuation of the motor current is synchronized with the rotation cycle of the drum 54. That is, the positive and negative peaks of the motor current fluctuation appear at substantially the same position for each rotation of the drum with respect to the rotation marker. This positive peak position indicates a position on the drum 54 where an unbalanced load exists. Further, the amplitude value of the fluctuation of the motor current is a value corresponding to the magnitude of the unbalanced load. FIG. 4 is an example of the result of measuring the relationship between the magnitude of the unbalanced load and the amplitude value of the motor current variation. Based on such a relationship, the magnitude of the unbalanced load can be estimated from the variation amplitude. Since the motor current fluctuation factor is not necessarily limited to the unbalanced load, in order to accurately obtain the fluctuation amplitude due to the influence of the unbalanced load, only the frequency component near the rotation speed of the drum 54 is selected from the motor current fluctuation components. It is desirable to carry out a filtering process.

The unbalanced load determination unit 16 detects and determines the unbalanced load based on the detection signal from the motor current detection circuit 26 as follows. That is, the peak value detection unit 161 detects positive and negative peaks of the fluctuation of the motor current at each interval of the rotation marker input from the rotation sensor 24, that is, at each rotation period of the drum 54. The position information of each of the detected positive and negative peaks is input to the position determination unit 162, and the peak value information is input to the amplitude calculation unit 163.

Since the positive peak position is the position where the eccentric load exists, the position determination unit 162 detects the lag time from the rotation marker to the positive peak position to detect the eccentric load on the inner peripheral wall of the drum 54. Detect position. Then, it is determined whether or not this position is within the range of the desired position,
A positive level signal is output when the signal is within the range of the desired position. Here, the desired position is a position 180 ° opposite to the mounting position of the weight 60, and an allowable range in which a position detection error, a variation in the arrangement of the laundry, and the like are set in the vicinity thereof is set in advance. You.

The amplitude calculator 163 calculates the fluctuation amplitude value of the motor current for each rotation period of the drum 54 from the positive and negative peak values. As shown in FIG. 4, the amplitude value is a value corresponding to the magnitude of the unbalanced load, and thus, determining the amplitude value has the same meaning as determining the magnitude of the unbalanced load. Therefore, the amplitude determination section 164 determines whether or not the amplitude value is within a predetermined range, and outputs a positive level signal when the amplitude value is within the predetermined range. here,
The predetermined range is, as described later, a range of an eccentric load allowed after dehydration, an allowable range set in advance according to the weight of the weight 60, and the like.

The AND gate 165 obtains the logical product of the results of the determination of the magnitude and position of the eccentric load, so that the magnitude of the eccentric load is within a predetermined range and the weight 60 is substantially 180 °.
When it is located at the opposing position, a positive level signal is input to the rotation speed control unit 14. The rotation speed control unit 14 receives the determination result of the unbalanced load when the motor 22 is controlled so that the drum 54 rotates at a predetermined rotation speed described later, and switches and outputs the rotation speed designation signal according to the result. I do.

Next, the difference in the allowable range of the unbalanced load between the case where the drum having the unbalanced load applied to the drum itself as in the present invention and the case where the conventional drum having no unbalanced load is used will be described. explain. Now, the unbalanced load after dehydration is 1
If it is within 00 [g], it is assumed that abnormal vibration does not occur during the dehydration operation. It is also assumed that the weight of the laundry after the dehydration is reduced to half that before the dehydration by the dehydration operation.

(I) Allowable range of unbalanced load when there is no weight (drum itself does not have unbalanced load) As shown in FIG. 5A, the weights m1 and m2 before dehydration facing each other with respect to the center axis of the drum are determined. In the case where an unbalanced load occurs due to the imbalance of the laundry, the condition under which abnormal vibration does not occur during the spin-drying operation is expressed by the following equation (1). | M1−m2 | / 2 ≦ 100 (1) Therefore, from the expression (1), | m1−m2 | ≦ 200 (2) In the expression (2), the unbalanced load before dehydration is within 200 [g]. This indicates that if the laundry is arranged as described above, abnormal vibration during the spin-drying operation can be avoided.

(Ii) Allowable range of unbalanced load when a weight of M [g] is added As shown in FIG. 5 (b), laundry having weights m1 and m2 before dehydration facing each other with respect to the center axis of the drum and When an unbalanced load occurs due to the imbalance of the weight 60 having the weight M,
Conditions under which abnormal vibration does not occur during the dehydration operation are as follows (3) and (4)
It is shown by the formula. (m2 / 2)-[(m1 / 2) + M] ≦ 100 (3) [(m1 / 2) + M] − (m2 / 2) ≦ 100 (4) Now, for example, M = 300 [g]. Then, the equations (3) and (4) are summarized in the following equation (5). 400 ≦ m 2 −m 1 ≦ 800 (5) From Formula (5), the allowable range of unbalanced load before dehydration is given by the following Formula (6). 100 ≦ m2− (m1 + M) ≦ 500 (6)

(Iii) Difference in allowable range between case (i) and case (ii) Comparing equation (6) with equation (2), the addition of weight 60 allows the unbalanced load before dehydration. It can be seen that the range is doubled. Therefore, it is easy to keep the unbalanced load within the allowable range during the distributed operation of the laundry.

(Iv) (i) and (i) relating to detection accuracy of eccentric load
Difference in i) In the above-described unbalanced load detection based on the fluctuation of the motor current, the detection accuracy decreases when the unbalanced load is small, and when the unbalanced load is less than a certain unbalanced load, the detection becomes almost impossible due to disturbance or the like. For example, in the example shown in FIG. 4, detection is not possible when the eccentric load is 200 [g] or less, and detection is not possible when the eccentric load is 200 to 300 [g] (the range indicated by the broken line in FIG. 4). Poor accuracy and poor reliability. For this reason, it can be said that it is extremely difficult to actually re-arrange the laundry so as to satisfy the expression (2).

Assuming that the offset load can be reliably detected if the offset load is 300 [g] or more, the condition under which the offset load can be detected before dehydration in (ii) is shown by the following equation (7). It is. m2− (m1 + M) ≧ 300 (7) When M = 300 [g], before dehydration, which can detect an eccentric load from equations (6) and (7) and does not generate abnormal vibration. Is given by the following equation (8). 300 ≦ m2− (m1 + M) ≦ 500 (8) That is, by adding the weight 60, the unbalanced load allowable range before dehydration is moved to an area where the unbalanced load can be easily detected or can be detected more accurately. can do.

As described above, by adding the weight 60 and giving the drum 54 itself an uneven load in advance,
Has two effects. 1) When the laundry is distributedly operated, the possibility of falling within the allowable range is high because the allowable range of the unbalanced load is wide. In other words, the distributed operation of the laundry is facilitated. 2) Since the unbalanced load allowable range before dehydration is set in a region where the unbalanced load can be reliably detected, occurrence of abnormal vibration during dehydration operation due to missed detection can be avoided.

In the above description, the weight of the weight is 300
[g], but by appropriately selecting this, the unbalanced load allowable range before dehydration can be changed. Generally, when the unbalanced load after dehydration is set to P [g] or less, the unbalanced load allowable range before dehydration is expressed by the following equation (9). M−2P ≦ m2− (m1 + M) ≦ M + 2P (9) If the magnitude of the eccentric load is more than Q [g] and the magnitude can be reliably detected, the eccentric load can be detected and abnormal. The unbalanced load tolerance before dehydration that does not generate vibration is
The following equation (10) is obtained under the condition of Q ≧ M−2P. Q ≦ m2− (m1 + M) ≦ M + 2P (10) However, when laundry having a lighter weight than (M + Q) [g] is stored in the drum, the expression (10) is not satisfied. Therefore,
(M + Q) [g] is the minimum condition for the laundry input weight.

The above effect is obtained by imparting the drum 54 with an unbalanced load. However, even if the unbalanced load allowable range before dehydration is relaxed, this condition is satisfied in order to perform dehydration efficiently. It is necessary to arrange the laundry as quickly as possible. For this reason, in the centrifugal dehydrator of Example 1, the weight 6
By attaching the plate-shaped member 59 to the inner peripheral wall surface of the drum 54 where 0 is located, the drum radius of that portion is substantially reduced.

That is, whether the laundry rotates together with the drum 54 while being stuck to the inner peripheral wall surface of the drum 54 or falls during the rotation depends mainly on the magnitude relationship between the centrifugal force acting on each laundry and the gravity. Depends on. If the centrifugal force is the same rotation speed and the same weight, since the laundry located near the center of the drum 54 is smaller, the laundry located inside the plate-shaped member 59 falls during rotation, and There is a rotation speed at which the laundry located on the inner peripheral wall of the drum 54 other than the other does not fall. Therefore, when the laundry is dispersedly arranged, by rotating the drum 54 at such a rotation speed, it becomes easy to collect the laundry near the position facing the weight 60 by 180 °.

Hereinafter, the control procedure of the dewatering process will be specifically described with reference to the flowchart of FIG. As in the above description, it is assumed that the weight of the weight is 300 [g] and the eccentric load allowed after dehydration is within 100 [g]. However, it is clear from the above description that this condition can be appropriately changed. It is.

Immediately before the start of the dewatering process, the laundry inside the drum 54 is in a state of being stacked on the bottom as shown in FIG. First, in order to carry out the distributed arrangement of the laundry, the rotation of the drum 54 is started from a stopped state in which the weight 60 is positioned almost directly above, and the rotation speed is gradually increased. The low rotation speed N1 is set (step S10). That is, the rotation speed control unit 1
In step 4, the designated value of the rotation speed designation signal is increased stepwise until it becomes a value corresponding to the low rotation speed N1, and the inverter control circuit 20 applies a drive voltage corresponding to this to the motor 22. The low rotation speed N1 is a rotation speed slightly higher than the rotation speed at which the centrifugal force acting on the laundry inside the drum 54 is balanced with the gravity, in other words, the laundry rotates while the laundry is pressed against the inner peripheral wall surface of the drum 54. The rotation speed is set to be as low as possible within the range that can be achieved, and is appropriately determined according to the drum diameter and the like. For example, when the drum diameter is 700 [mm], the low speed N1 is about 50 [rpm], and the drum diameter is 910 [mm].
In this case, the low speed N1 is set to about 86 [rpm].

Until the drum 54 reaches the low rotation speed N1, the centrifugal force acting on each laundry gradually increases, but as described above, in the range where the rotation speed is lower than the low rotation speed N1, The centrifugal force acting on the laundry located inside the plate-shaped member 59 is more favored by gravity, and the centrifugal force acting on the laundry located on the inner peripheral wall of the other drum 54 has a rotational speed that exceeds gravity. Exists. That is,
At this rotation speed, the laundry located inside the plate-like member 59 almost falls during the rotation (see FIG. 7B).
As a result, the laundry is removed from portions other than the plate-like member 59, especially the weight 60.
Gather around the position L2 that is 180 ° opposite to

When the rotation speed of the drum 54 is increased to the low rotation speed N1, the laundry can be appropriately dispersed under the following conditions. When the total weight of the laundry is 6 [kg], the drum diameter is 910 [mm], and the low-speed rotation speed N1 is 86 [rpm], the time required to reach the low-speed rotation speed N1 from the state where the drum 54 is stopped is one. .
The acceleration is set to be 1.2 to 2.4 [πr so that the time becomes 2 to 2.4 seconds.
ad / s ² ]. If the acceleration is too large, the laundry is not dispersed and remains solidified in the vicinity of the position L2, and the entire laundry shifts rearward in the rotational direction (the position L4 in FIG. 7B) due to rapid acceleration. A proper balance cannot be obtained. On the other hand, if the acceleration is too small, the laundry is dispersed, but at a rotation speed slightly lower than the rotation speed at which the centrifugal force acting on the laundry pressed against the inner peripheral wall of the drum 54 and the gravity balance, the position L2 The laundry in the vicinity is shifted forward (toward the position L3 in FIG. 7B) due to the influence of gravity, so that a proper balance cannot be obtained.

When the rotation speed of the drum 54 is a low rotation speed N1
When the laundry reaches the drum 54
It rotates while being pressed against the inner peripheral wall surface (see FIG. 7
(C)). At this time, as described above, the eccentric load determination unit 1
In step 6, the magnitude and position of the eccentric load are determined. That is,
The magnitude and position of the eccentric load are detected based on the fluctuation component of the motor current detected by the motor current detection circuit 26, and the magnitude of the eccentric load is in the range of 300 to 500 [g] and the position is L2. It is determined whether it is within a predetermined range in the vicinity (step S11).

Now, assuming that laundry of weight 1 kg containing water is stored in the drum 54, the positions L1, L2, L3
And L4, for example, 0 [g], 800 [g],
If the laundry is dispersed so as to have a weight distribution of 100 [g] and 100 [g], an unbalanced load having a size of 500 [g] will be near the position L2. In this case, the unbalanced load determination unit 16 outputs a positive level signal to the rotation speed control unit 14. Thereby, the step proceeds from S11 to S13, and the medium-speed dehydration rotation is executed. That is, when the rotation speed control unit 14 receives a positive level signal from the unbalanced load determination unit 16, the rotation speed control unit 14 outputs a rotation speed designation signal such that the rotation speed of the drum 54 becomes the middle rotation speed N 2, and the inverter control circuit 20 Applies a drive voltage corresponding to this to the motor 22. Here, for example, the medium rotation speed N2 is set to about 500 [rpm]. The rough drawing is performed by rotating the drum 54 at the medium rotation speed N2 for a predetermined time.

If it is determined in step S11 that the magnitude of the eccentric load is not within the predetermined range or is not in the vicinity of the position L2, the process proceeds to step S12, in which the rotational speed is reduced to such a low speed that the drum 54 stops. After that, the speed is gradually increased again to the low rotation speed N1 (step S10). In this process, the laundry is agitated and rearranged, and it is determined again whether or not the unbalanced load is as desired (step S11).

After the medium-speed spinning, the process proceeds to step S14, where the high-speed spinning is performed. That is, the rotation speed control unit 14 determines that the rotation speed of the drum 54 is high-speed rotation speed N3.
And the inverter control circuit 20 applies a drive voltage corresponding to the rotation speed signal to the motor 22. The high-speed rotation speed N3 is preferably a value according to the type of fiber of the laundry, and is generally set to a value according to the dehydration mode specified by the operator. Typically, it is set to, for example, about 700 [rpm]. When the drum 54 is rotated at the high rotation speed N3 for a predetermined time, complete dehydration is performed, and the dehydration process ends.

[Embodiment 2] Next, an embodiment (hereinafter referred to as "embodiment 2") of a centrifugal dehydrator according to the second invention will be described with reference to the configuration diagram of FIG. In the second embodiment,
Instead of the plate member 59 being provided in the drum 54 as in the first embodiment, the main shaft 64 itself is attached at a position shifted from the center axis of the drum 54 in the direction of the weight 60. That is, the drum 54 is rotated about the eccentric rotation axis. For this reason, the drum 54
The distance to the inner peripheral wall differs depending on the position, and the weight 60
The position of the baffle 58 where the is installed is the shortest distance, and the position opposite to the weight 60 by 180 ° is the longest distance.

Since the drum 54 having such a structure already has an eccentric load due to the rotation shaft being displaced from the center point of the drum 54, the weight 60 takes into consideration the eccentric load, that is, the weight of the first embodiment. Heavier weight than the case.

When the dewatering process is executed according to the flowchart of FIG. 6, the laundry located on the inner peripheral wall surface of the drum 54 near the weight 60 in the range of the rotation speed lower than the low speed N1 in step S10. Gravity exceeds the acting centrifugal force, and there is a rotational speed at which the centrifugal force acting on the laundry near the position facing the weight 60 by 180 ° exceeds the gravity. Therefore, as in the first embodiment, the laundry is distributed around the position facing the weight 60 by 180 °, so that the magnitude and position of the eccentric load can easily fall within a desired range.

Although the above embodiment has been described with reference to a drum type washing machine, it is apparent that the present invention can be applied to a dry cleaner using a petroleum solvent or the like.

Further, as a method of detecting the uneven distribution of the laundry in the drum, for example, a mercury switch or an acceleration sensor may be used in addition to the method of detecting the motor current.

[0053]

As described above, according to the centrifugal dehydrators according to the first and second aspects of the present invention, the allowable range of the unbalanced load before dehydration or dewatering is widened, and furthermore, the condition of the allowable range The laundry is distributed so that is easily filled. For this reason, it is possible to reliably avoid occurrence of abnormal vibration and abnormal noise during the dehydration or dewatering operation, to prevent the dehydration or dewatering time from being prolonged, and to perform efficient dehydration or dewatering operation. it can.

[Brief description of the drawings]

FIG. 1 is an overall sectional view (a) showing a configuration of a drum type washing machine equipped with a centrifugal dehydrator according to a first invention, and a configuration diagram around a drum (b).

FIG. 2 is an electric block diagram of the drum type washing machine of FIG. 1;

FIG. 3 is a diagram showing an example of a fluctuation component of a motor current.

FIG. 4 is a diagram illustrating an example of a relationship between the magnitude of an eccentric load and a fluctuation amplitude of a motor current.

FIG. 5 is a schematic diagram for explaining a difference in an eccentric load allowable range depending on whether a weight is added to a drum.

FIG. 6 is a flowchart for explaining a procedure of drum rotation control.

FIG. 7 is a schematic diagram showing the movement of laundry inside the drum.

FIGS. 8A and 8B are an overall cross-sectional view showing a configuration of a drum type washing machine equipped with a centrifugal dehydrator according to a second invention, and a configuration diagram around a drum, FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 ... Control part 12 ... Central control part 14 ... Rotation speed control part 16 ... Uneven load determination part 161 ... Peak value detection part 162 ... Position determination part 163 ... Amplitude calculation part 164 ... Amplification determination part 165 ... AND gate 20 ... Inverter control Circuit 22: Motor 24: Rotation sensor 26: Motor current detection circuit 54: Drum 59: Plate member 60: Weight 64: Spindle

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-2-195988 (JP, A) JP-A-4-166192 (JP, A) JP-A-61-90694 (JP, A) JP-A-1- 268597 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) D06F 33/02 D06F 23/02 D06F 49/04

Claims (4)

(57) [Claims] 1. A centrifugal dehydrator for storing laundry such as clothes in a basket-shaped drum and rotating the drum about a horizontal axis to dehydrate the laundry or remove a washing solvent. A) a cylindrical drum having a partial load on a part of the inner peripheral wall and having a peripheral portion bulging inward around the position of the partial load; b) a motor for driving the drum to rotate; Detecting the magnitude and position of the eccentric load including the eccentric load of the stored laundry and the drum itself, and the magnitude of the eccentric load is within a predetermined range, and the eccentric load of the drum itself is included in the position. And d) a centrifugal force acting on the laundry due to gravity from a state in which the unbalanced load of the drum itself is opposed to the laundry. Increase the rotation speed of the drum to a rotation speed that exceeds When the magnitude and position of the unbalanced load are determined to be as desired at the rotation speed, the motor is controlled to rotate the drum at a rotation speed for performing the dehydration or dewatering operation. A centrifugal dehydrator, comprising: a rotation speed control unit. 2. A centrifugal dehydrator for storing laundry such as clothes in a basket-shaped drum and rotating the drum about a horizontal axis to dewater the laundry or remove a washing solvent. A) a cylindrical drum provided with a partial load on a part of the inner peripheral wall and having a rotational axis shifted in the direction of the position of the partial load; b) a motor for driving the drum to rotate; Detecting the magnitude and position of the eccentric load including the eccentric load of the laundry contained in the drum and the drum itself, and determining that the magnitude of the eccentric load is within a predetermined range and the position of the eccentric load of the drum itself. Determining means for determining whether or not the position is in the vicinity of a load substantially 180 ° opposite to the load; d) the centrifugal force acting on the laundry is changed by gravity from the state in which the unbalanced load of the drum itself is opposed to the laundry. The rotation speed of the drum up to the rotation speed that exceeds When the magnitude and position of the unbalanced load are determined to be as desired at the rotation speed, the motor is controlled to rotate the drum at a rotation speed for performing the dehydrating or draining operation. A centrifugal dewatering device, comprising: 3. The centrifugal dehydrator according to claim 1, wherein the rotation speed control means is configured to determine whether any of the magnitude or position of the eccentric load is not as desired. After the drum is temporarily stopped or reduced to a rotation speed close to the stop, the motor is controlled so as to increase the rotation speed of the drum again to a rotation speed for determining the unbalanced load. Centrifugal dehydrator. 4. The centrifugal dewatering device according to claim 1, wherein the rotational speed for determining the unbalanced load by the determining means is such that the centrifugal force acting on the laundry inside the drum and gravity are balanced. A centrifugal dehydrator having a rotation speed slightly higher than the rotation speed.