JPH09140986A - Centrifugal dehydrator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent abnormal vibration as caused by imbalance of washings during the dehydrating operation. SOLUTION: A drum 54 has an unbalanced load with a weight 60 added thereto. A plate-shaped member 59 shortens the distance in substance from the inner circumferential wall to a horizontally rotating shaft of the drum 54 near the weight 60. With the dehydration, the weight of the washings decreases but as the weight of the weight 60 remains unchanged, more of the washings is arranged being scattered near the position facing the weight 60 at 180 deg. before the dehydration so that a balance is taken after the dehydration. When the drum 54 is rotated at a low speed, the centrifugal force working on the washings is small and the washings are not placed inside the plate-shaped member 59 but they gather easily near the position facing it at 180 deg.. Thus, the washings are placed easily to ensure that the unbalanced load is put as desired.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention stores laundry such as clothes in a basket-shaped drum and rotates the drum at a high speed around a horizontal axis to dehydrate the laundry or remove the solvent for washing. The present invention relates to a centrifugal dehydrator that performs liquid.

The drum type centrifugal dehydrator has a structure in which laundry such as washed clothes is housed inside a basket-shaped drum and the drum is rotated at high speed about a horizontal axis. One of the major problems in this type of centrifugal dehydrator is that when the drum is rotated at high speed in the state where the laundry is not evenly distributed on the inner peripheral wall surface of the drum, it is abnormal due to the imbalance of the mass distribution around the rotation axis. Vibration or abnormal noise is generated.

Conventionally, a centrifugal dehydrator for the purpose of solving such problems has been proposed. For example,
In the centrifugal dehydrator disclosed in Japanese Patent Laid-Open No. 6-254294, there is disclosed a method in which the laundry in the drum is uniformly distributed by the low speed rotation of the drum before the dehydration operation by the 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 an extremely short time, and then the drum is rotated at a speed slightly higher than the rotation speed but sufficiently slower than the rotation speed during the dehydration operation. Disperse the laundry by combining them.

Further, in this prior art, a vibration monitoring sensor is installed at the pedestal portion of the apparatus as a means for detecting the unbalance of the laundry, and the rotation speed of the drum is increased to a high rotation speed for dehydration operation. When the vibration monitoring sensor detects an abnormal vibration when it is turned on, the rotation speed thereof is reduced.

[0005]

However, even if the method of controlling the rotation of the drum as in the above-mentioned conventional technique is used, the laundry is not always uniformly distributed by one rotation of the drum at low speed. If abnormal vibration occurs when the drum is rotated at a high speed after an attempt is made to disperse the laundry by the low speed rotation of the drum, the dispersion must be performed by the low speed rotation again. As described above, 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, there arises a problem that the dehydration process takes a long time.

Further, when the drum is rotated so that the laundry is evenly distributed as in the above-mentioned prior art, particularly long clothes are entangled while the laundry is located at the center of the drum, which causes a so-called tearing phenomenon. There is a case to let. Then, if the dehydration operation is continued in this state, there is a possibility that the laundry may be torn.

The present applicant has proposed a centrifugal dehydrator for solving the above problems in Japanese Patent Application No. 7-113628. In this new centrifugal dehydrator, a weight is added in advance to a part of the inner peripheral wall surface so that the drum itself has an unbalanced load, and the size and position of the unbalanced load including the unbalanced load of the drum itself become predetermined. So the laundry is rearranged.
As will be described in detail later, according to this apparatus, since the allowable range of the unbalanced load is widened when the laundry is distributed, the distributed arrangement can be easily made.

The present invention is a further improvement of the centrifugal dewatering device according to the above-mentioned application, and an object thereof is to disperse and arrange the laundry in a state in which abnormal vibration is not generated during the dewatering operation before the dewatering operation. It is an object of the present invention to provide a centrifugal dewatering device capable of efficiently performing dewatering and quickly preventing the laundry from being torn due to a tearing phenomenon.

[0009]

A centrifugal dehydrator according to a first aspect of the present invention, which has been made to solve the above-mentioned problems, accommodates laundry such as clothes in a basket-shaped drum, and uses the drum as a horizontal shaft. In a centrifugal dewatering device that spins the laundry around or spins the laundry to remove the washing solvent, a) a part of the inner peripheral wall has an eccentric load, and the periphery of the position of the eccentric load is inward. Detecting the size and position of the eccentric load, which is a combination of a bulging cylindrical drum, b) a motor that rotationally drives the drum, and c) the laundry contained in the drum and the eccentric load of the drum itself. And a means for determining whether or not the magnitude of the unbalanced load is within a predetermined range and the position is in the vicinity of a position facing the unbalanced load of the drum itself by about 180 °, and d) the drum itself. From the state where the unbalanced load that the When the rotational speed of the drum is increased to a rotational speed at which the centrifugal force acting on the laundry exceeds gravity, and the magnitude and position of the unbalanced load at the rotational speed are determined to be as desired. And a rotation speed control means for controlling the motor so as to rotate the drum at a rotation speed for performing the dehydration or dewatering operation.

A centrifugal dehydrator according to a second aspect of the present invention, which has been made to solve the above-mentioned problems, stores laundry such as clothes in a basket-shaped drum and rotates the drum about a horizontal axis. In a centrifugal dehydrator for dehydrating laundry or draining washing solvent by: a) a cylinder having an eccentric load on a part of the inner peripheral wall and having a rotational axis displaced in the position direction of the eccentric load. A drum having a shape, b) a motor for driving the drum to rotate, and c) the size and position of the unbalanced load, which is the combined unbalanced load of the laundry stored in the drum and the drum itself, and is detected. A 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 °; From the state of facing the laundry to the laundry When the rotational speed of the drum is increased to a rotational speed at which the centrifugal force used exceeds gravity, and the magnitude and position of the unbalanced load at the rotational speed are determined to be as desired, dehydration or Rotation speed control means for controlling the motor so as to rotate the drum at a rotation speed for performing the liquid removal operation.

Further, in the centrifugal dehydrator according to the first or second aspect of the invention, when the rotation speed control means determines that either the magnitude or the position of the unbalanced load is not as desired, Controlling the motor so as to raise the rotation speed of the drum to a rotation speed for judging the unbalanced load again after the drum is once stopped or reduced to a rotation speed close to the stop. It has a feature.

The rotation speed for determining the unbalanced load by the determination means is preferably a rotation speed slightly higher than the rotation speed at which the centrifugal force acting on the laundry inside the drum and the gravity balance. .

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION The drum in the centrifugal dehydrator according to the first aspect of the present invention is applied with an unbalanced load, for example, by adding a weight to a part of the inner peripheral wall of the drum. The dehydration operation in which the drum is rotated at a high speed reduces the weight of the laundry but does not change the weight of the weight. Therefore, in order to balance the weight after the dehydration operation, the laundry is distributed and arranged around the position facing the position of the weight 180 ° before the dehydration operation. Therefore, the predetermined range, which is the reference for determining the magnitude of the unbalanced load in the determination means, is the allowable deviation after the spin-drying operation in consideration of the weight of the weight and the degree of decrease in the weight of the laundry during the spin-drying operation. It is set in advance based on the magnitude of the load, that is, the allowable range that does not cause abnormal vibration.

The determining means detects the magnitude of the eccentric load and the position on the inner peripheral wall of the drum, for example, based on the fluctuation of the motor current flowing when the motor is rotationally driven, and these are determined as described above. It is determined whether it is in a desired state. The unbalanced load can be detected and determined when all the laundry in the drum is rotating while being pressed against the inner peripheral wall surface of the drum by the centrifugal force.

When the drum is initially stopped, the laundry is firmly stacked on the bottom of the drum due to gravity. When the motor is started and the rotation of the drum is gradually increased, centrifugal force begins to act on each laundry. Therefore, in the initial stage of rotation, the laundry that is lifted upward as the drum rotates drops downward during rotation, but when the rotation speed increases, it acts on the laundry that sticks to the inner wall surface of the drum. The centrifugal force that overcomes overcomes gravity and rotates with the drum without falling during rotation. However, since the centrifugal force acting on the laundry having the same rotation speed and the same weight at a position closer to the rotation axis of the drum is smaller, it acts on the laundry located at the portion where the drum bulges inward. The centrifugal force generated is smaller than the centrifugal force acting on the other laundry located on the inner peripheral wall surface of the drum.

Therefore, there is a rotation speed such that the laundry located in the bulging portion falls during the rotation and the other laundry located on the inner peripheral wall surface of the drum does not fall and sticks and rotates. To do. As a result, the laundry is likely to be concentrated near the drum inner peripheral wall which is opposed to the weight by 180 °, and the unbalanced load can be easily contained in the desired range as described above.

Further, in the centrifugal dehydrator according to the second aspect of the present invention, the rotating shaft itself of the cylindrical drum is formed off the center of the circle. As a result, the distance from the horizontal axis of rotation to the inner wall surface of the drum is non-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 be concentrated near the drum inner peripheral wall facing the weight by 180 °.

The distributed arrangement of the laundry as described above must be carried out at a rotation speed such that the gravity is greater than the centrifugal force acting on a part of the laundry, while the unbalanced load is detected and determined at any time. The centrifugal force that acts on the laundry must also be performed at a rotation speed that exceeds gravity. For this reason, when the size and the position are not as desired in the unbalanced load determination, the rotation speed of the drum is once reduced to make all the laundry easy to move. After that, the rotation speed is increased again to disperse and arrange the laundry. As described above, in order to reduce the time required to re-execute the distributed arrangement of the laundry, it is preferable to detect and determine the unbalanced load at a rotation speed as slow as possible. The unbalanced load is detected and determined at a rotational speed that is slightly higher than the rotational speed at which the force and gravity balance.

[0019]

【Example】

[Embodiment 1] Hereinafter, an embodiment (hereinafter referred to as "embodiment 1") of a centrifugal dehydrator according to the first invention will be described with reference to the drawings. 1A and 1B are views showing the configuration 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 portion, and FIG. 5 is a diagram showing an example of an electric system block diagram of the drum type washing machine, FIG. 3 is a diagram showing an example of a fluctuation component of the motor current, FIG. 4 is a diagram showing an example of a relationship between the magnitude of the unbalanced load and the fluctuation amplitude of the motor current, FIG.
FIG. 6 is a schematic diagram for explaining the difference in the unbalanced load allowable range depending on whether a weight is added to the drum, FIG. 6 is a flowchart for explaining the procedure of the dehydration process, and FIG. 7 is for the drum type washing machine of FIG. It is a schematic diagram which shows the movement condition of the laundry in a drum.

First, the overall construction 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 accommodating laundry is installed inside the outer tub 52 while being supported by a main shaft 64. Water passage holes 56 are formed in the peripheral wall of the drum 54, and the wash water supplied into the outer tub 52 is supplied through the water passage holes 5
The water flowing into the drum 54 through 6 and drained from the laundry in the drum 54 is discharged to the outer tub 52. On the inner peripheral wall of the drum 54, baffles 58 for scraping the laundry with the rotation are installed at two positions with a rotation angle of 120 °. Further, a weight 60 is attached at a position distant from the baffle 58 by an angle of rotation of 120 °, and a plate-like 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. Further, the laundry is stored in the drum 54 through the laundry input port 62.

The main shaft 64 is a bearing 66 mounted on the outer tub 52.
The main pulley 68 is attached to the tip of the main pulley 68. A motor 22 for rotatably driving the drum 54 is arranged below the outer tub 52, and a motor pulley 72 is attached to the rotation 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 wash water and the rinse water are externally supplied to the outer tub 52 through the water supply port 74, and the water amount is adjusted by the water supply valve 76. The water after cleaning 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 section 82. The circuit section 82 is composed of a control section 10, an inverter control circuit 20 and the like, which will be described later. The rotation sensor is
The light emitting portion 24a installed on the outer wall of the outer tank 52 and the light receiving portion 24 installed on the inner wall of the frame 50 with the main pulley 68 interposed therebetween.
b. The opening 6 is formed in the ring-shaped portion of the main pulley 68 located between the light emitting portion 24a and the light receiving portion 24b.
9 is provided, and the light from the light emitting portion 24a reaches the light receiving portion 24b through the opening 69 only once in one rotation period of the drum 54. As a result, the light receiving unit 24b of the rotation sensor generates a detection signal in synchronization with the rotation of the drum 54, that is, a rotation marker.

Next, the electrical configuration centering on the circuit portion 82 and its operation will be described with reference to FIG. The control unit 10 mainly composed of a microcomputer is a central control unit 1.
2, a rotation speed control unit 14, an unbalanced load determination unit 16 and a memory 18. The unbalanced 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.

An operation program for advancing each process of cleaning, rinsing and dehydration is stored in the memory 18 in advance. When an operator performs a key operation from an operation unit (not shown) to select a dehydration mode, for example, the type of fibers of clothes to be dehydrated, and then gives an instruction to start the dehydration process, the central control unit 1
2 reads the corresponding operation program from the memory 18 and executes the operation program to advance the process of the dehydration process.

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

The current flowing through the motor 22 is detected by the motor current detection circuit 26 and input to the eccentric load determination unit 16. When the drum 54 has an eccentric load, the motor current has a fluctuation component corresponding to the eccentric load. FIG. 3 is an example of a waveform of the motor effective value current when there is an unbalanced 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 fluctuation of the motor current appear at substantially the same position for each rotation of the drum with respect to the rotation marker. This positive peak position indicates the position where an unbalanced load exists on the drum 54. Further, the amplitude value of the fluctuation of the motor current has 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 eccentric load and the amplitude value of the motor current fluctuation, and the magnitude of the eccentric load can be estimated from the fluctuation amplitude based on such a relationship. It should be noted that since the fluctuation factor of the motor current is not necessarily the eccentric load, only the frequency component in the vicinity of the rotation speed of the drum 54 is selected from the fluctuation components of the motor current in order to accurately obtain the fluctuation amplitude due to the influence of the eccentric load. It is desirable to carry out a filtering process.

The eccentric load determination unit 16 detects and determines the eccentric load based on the detection signal from the motor current detection circuit 26 as follows. That is, the peak value detecting unit 161 detects the positive and negative peaks of the fluctuation of the motor current for each interval of the rotation markers input from the rotation sensor 24, that is, for each one 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 unbalanced load exists, the position determination unit 162 detects the delay time from the rotation marker to the positive peak position to detect the unbalanced load on the inner peripheral wall of the drum 54. Detect the 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 position is within the desired position. Here, the desired position is a position that is opposed to the mounting position of the weight 60 by 180 °, and an allowable range in which a position detection error, a variation in the arrangement of laundry, and the like are taken into consideration is set in the vicinity of this position in advance. It

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, since the amplitude value is a value corresponding to the magnitude of the unbalanced load, determining the amplitude value has the same meaning as determining the magnitude of the unbalanced load. Therefore, the amplitude determination unit 164 determines whether or not the amplitude value is within the predetermined range, and when it is within the predetermined range, a positive level signal is output. here,
As will be described later, the predetermined range is an allowable range that is set in advance according to the range of the unbalanced load that is allowed after dehydration, the weight of the weight 60, and the like.

The AND gate 165 obtains the logical product of the determination results 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 has an angle of about 180 °.
When the positions are opposite to each other, 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 while the drum 54 is controlling the motor 22 to rotate at a predetermined rotation speed described later, and switches the rotation speed designation signal according to the determination result and outputs the signal. To do.

Next, the difference in the allowable range of the eccentric load between the case of using the drum having an eccentric load as in the present invention and the case of using the conventional drum having no eccentric load will be described. explain. Unbalanced load after dehydration is now 1
If it is within 00 [g], abnormal vibration does not occur during the dehydration operation. Further, it is assumed that the laundry weight after dehydration becomes half of that before dehydration by the dehydration operation.

(I) Unbalanced load allowable range when there is no weight (the drum itself has no unbalanced load) As shown in FIG. 5 (a), the pre-dewatering weights m1 and m2 facing each other with respect to the drum central axis are set as follows. When an unbalanced load is generated due to the unbalance of the laundry, the condition that abnormal vibration does not occur during the dehydration operation is expressed by the following equation (1). | M1-m2 | / 2 ≦ 100 (1) Therefore, from equation (1), | m1-m2 | ≦ 200 (2) Equation (2) has an unbalanced load within 200 [g] before dehydration. By arranging the laundry in this way, it is possible to avoid abnormal vibration during the dehydration operation.

(Ii) Permissible range of unbalanced load when a weight of M [g] is added: As shown in FIG. 5 (b), a laundry having pre-dewatering weights m1 and m2 facing each other with respect to the drum center axis, and When an unbalanced load is generated due to the imbalance of the weight 60 of the weight M,
The conditions for preventing abnormal vibration during 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, 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 the following formula (6). 100 ≦ m2− (m1 + M) ≦ 500 (6)

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

(Iv) (i) and (i
Difference of i) In the eccentric load detection based on the fluctuation of the motor current as described above, if the eccentric load is small, the detection accuracy is lowered, and if the eccentric load is less than a certain eccentric load, the detection becomes almost impossible due to the influence of disturbance or the like. For example, in the example shown in FIG. 4, it is impossible to detect in the range where the eccentric load is 200 [g] or less, and in the range where the eccentric load is 200 to 300 [g] (the range shown 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 rearrange the laundry so as to satisfy the formula (2).

Assuming that the unbalanced load can be surely detected if the unbalanced load is 300 [g] or more, the condition under which the unbalanced load can be detected before dehydration in (ii) is shown by the following equation (7). Be done. m2− (m1 + M) ≧ 300 (7) When M = 300 [g], it is possible to detect an unbalanced load from Eqs. (6) and (7), and before dehydration without abnormal vibration. The allowable range of unbalanced load is expressed 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 a region where the unbalanced load can be easily detected or more accurately detected. can do.

As described above, by adding the weight 60 to give the drum 54 itself an unbalanced load in advance, the following 2
Produces one effect. 1) When the laundry is distributed and operated, the allowable range of unbalanced load is wide, so the probability of falling within the allowable range is high. That is, the distributed arrangement operation of the laundry becomes easy. 2) Since the unbalanced load allowable range before dehydration is set to the region where unbalanced load can be reliably detected, it is possible to avoid the occurrence of abnormal vibration during dehydration operation due to missed detection.

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

If the drum 54 is provided with an eccentric load, the above-mentioned effects are obtained. However, even if the eccentric load allowable range before dehydration is relaxed, this condition is satisfied in order to perform dehydration efficiently. So it is necessary to place the laundry quickly. Therefore, in the centrifugal dehydrator of the first embodiment, the weight 6
By attaching the plate 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 is rotated together with the drum 54 while being attached to the inner peripheral wall surface of the drum 54 or dropped during the rotation mainly depends on the magnitude of the centrifugal force acting on each laundry and the gravity. Depends on. The centrifugal force is smaller for the laundry near the center of the drum 54 if the rotation speed is the same and the weight is the same. Therefore, the laundry located inside the plate member 59 falls during the rotation, Other than that, there is a rotation speed at which the laundry located on the inner wall surface of the drum 54 does not fall. Therefore, when the laundry is dispersed and 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 °.

The control procedure of the dehydration process will be specifically described below with reference to the flowchart of FIG. Similar to the above explanation, it is assumed that the weight of the weight is 300 [g] and the unbalanced load allowed after dehydration is within 100 [g]. However, it is clear from the above explanation that this condition can be changed appropriately. Is.

Immediately before the dewatering process is started, the laundry in the drum 54 is in a state of being stacked on the bottom as shown in FIG. 7 (a). First, in order to disperse and arrange this laundry, the rotation of the drum 54 is started from the stopped state in which the weight 60 is located almost right above, the rotation speed is gradually increased, and finally, the uneven load determination is performed. 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 gradually increased until it becomes a value corresponding to the low speed 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 that is slightly higher than the rotation speed at which the centrifugal force acting on the laundry inside the drum 54 balances with gravity, in other words, the laundry rotates while being pressed against the inner wall surface of the drum 54. The rotation speed is set as slow as possible within a possible range, and is appropriately determined according to the drum diameter and the like. For example, when the drum diameter is 700 [mm], the low speed rotation speed N1 is about 50 [rpm] and the drum diameter is 910 [mm].
At this time, the low speed rotation speed N1 is set to about 86 [rpm].

While the centrifugal force acting on each laundry gradually increases until the drum 54 reaches the low speed rotation speed N1, as described above, in the range where the rotation speed is slower than the low speed rotation speed N1. The gravity is superior to the centrifugal force acting on the laundry located inside the plate member 59, and the centrifugal force acting on the laundry located on the other inner peripheral wall of the drum 54 has a rotation speed superior to the 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).
In the end, the laundry is the portion other than the plate member 59, especially the weight 60.
Many gather around the position L2 which is 180 ° opposite to.

When increasing the rotation speed of the drum 54 to the low rotation speed N1, specifically, for example, 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 in which the drum 54 is stopped is 1 ．
Acceleration of 1.2 to 2.4 [πr
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 sudden acceleration causes the entire laundry to shift backward (in the direction of the position L4 in FIG. 7B) in the rotation direction, The proper balance cannot be achieved. On the other hand, if the acceleration is too small, the laundry is dispersed, but at a rotational speed slightly lower than the rotational speed at which the centrifugal force acting on the laundry pressed against the inner peripheral wall surface of the drum 54 and the gravity balance, the position L2 Laundry in the vicinity shifts to the front (at the position L3 side in FIG. 7B) due to the influence of gravity, and similarly, proper balance cannot be obtained.

The rotation speed of the drum 54 is a low rotation speed N1.
When all the laundry reaches the drum 54 due to centrifugal force.
Rotates while being pressed against the inner wall surface ((Fig. 7
(C)). At this time, as described above, the unbalanced load determination unit 1
At 6, the magnitude and position of the unbalanced load is 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, the magnitude of the eccentric load is within the range of 300 to 500 [g], and the position is L2. It is determined whether or not it is within a predetermined range in the vicinity (step S11).

Assuming that the laundry containing water and having a weight of 1 kg is accommodated in the drum 54, the positions L1, L2, L3 are stored.
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 magnitude of 500 [g] is near the position L2. In this case, the eccentric load determination unit 16 outputs a positive level signal to the rotation speed control unit 14. As a result, the step proceeds from S11 to S13, and the medium speed dewatering 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 medium rotation speed N2, and the inverter control circuit 20. Applies a drive voltage corresponding to this to the motor 22. Here, for example, the medium speed N2 is about 500 [rpm]. Coarse drawing is performed by rotating the drum 54 at a medium speed N2 for a predetermined time.

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

After the medium speed dewatering rotation, the step proceeds to S14 to execute the high speed dewatering rotation. That is, the rotation speed control unit 14 determines that the rotation speed of the drum 54 is the high rotation speed N3.
Then, the inverter control circuit 20 applies a drive voltage corresponding to the rotation speed signal to the motor 22. This high-speed rotation speed N3 is preferably a value that matches the type of fibers in the laundry, and thus is generally a value that corresponds to the dehydration mode designated by the operator. The standard value is, for example, about 700 [rpm]. The drum 54 is rotated at a high rotation speed N3 for a predetermined period of time to perform complete dehydration, and the dehydration process is completed.

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

Since the drum 54 having such a configuration already has an unbalanced load due to the rotation axis deviating from the center point of the drum 54, the weight 60 has a weight in consideration of the unbalanced load, that is, in the first embodiment. It is heavier than the case.

When the dehydration process is executed according to the flow chart 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 rotation speed N1 in step S10. Gravity is greater than the centrifugal force that acts, and the centrifugal force that acts on the laundry in the vicinity of the position facing the weight 60 by 180 ° has a rotation speed that exceeds gravity. Therefore, as in the case of the first embodiment, the laundry is dispersedly arranged around the position facing the weight 60 by 180 °, so that the magnitude and position of the eccentric load are likely to be within the desired range.

Although the above embodiments have been described with respect to the drum type washing machine, it is obvious that the present invention can be applied to a dry cleaner using a petroleum solvent or the like.

Further, as a method of detecting uneven distribution of 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 dehydrator according to the first and second aspects of the present invention, the allowable range of the unbalanced load before dehydration or drainage is widened, and the conditions of the allowable range are further increased. The laundry is distributed so that it can be easily filled. Therefore, it is possible to reliably avoid the occurrence of abnormal vibration or abnormal noise during the dehydration or dewatering operation, and prevent the dehydration or dewatering time from being prolonged so that the efficient dehydration or dewatering operation can be performed. 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 aspect of the invention and a configuration diagram around a drum (b).

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

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

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

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

FIG. 8 is an overall sectional view (a) showing a configuration of a drum type washing machine equipped with a centrifugal dehydrator according to a second aspect of the invention and a configuration diagram (b) around a drum.

[Explanation of symbols]

10 ... Control part 12 ... Central control part 14 ... Rotation speed control part 16 ... Unbalanced load determination part 161 ... Peak value detection part 162 ... Position determination part 163 ... Amplitude calculation part 164 ... Amplitude 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

Claims (4)

[Claims] 1. A centrifugal dehydrator in which a laundry such as clothes is accommodated in a basket-shaped drum and the drum is rotated about a horizontal axis to dehydrate the laundry or to remove a cleaning solvent. A) a cylindrical drum having an eccentric load on a part of the inner peripheral wall, and the periphery of the position of the eccentric load bulges inward, b) a motor for rotationally driving the drum, and c) the drum. The size and position of the unbalanced load including the unbalanced loads of the stored laundry and the drum itself are detected, and the size of the unbalanced load is within a predetermined range and the position of the unbalanced load of the drum itself is detected. And (d) a determination means for determining whether or not it is in the vicinity of a position facing by approximately 180 °, and d) the centrifugal force acting on the laundry changes from gravity from the state where the unbalanced load of the drum itself faces the laundry. Increase the rotation speed of the drum to a higher rotation speed And, when it is determined that the magnitude and position of the unbalanced load is at the desired value at the rotation speed, the motor is controlled to rotate the drum at the rotation speed for performing the dehydration or drainage operation. A centrifugal dewatering device comprising: a rotation speed control means. 2. A centrifugal dehydrator in which a laundry such as clothes is accommodated in a basket-shaped drum, and the drum is rotated about a horizontal axis to dehydrate the laundry or to remove a cleaning solvent. A) a cylindrical drum having an eccentric load on a part of the inner peripheral wall and having a rotational axis displaced in the position direction of the eccentric load; b) a motor for rotationally driving the drum; The size and position of the eccentric load, which is a combination of the eccentric load of the laundry contained in the drum and the eccentric load of the drum itself, is detected, and the size of the eccentric load is within a predetermined range and the position is an eccentric load Determining means for determining whether or not the position is near a position facing the load by approximately 180 °, and d) the centrifugal force acting on the laundry from the state where the unbalanced load of the drum itself faces the laundry. The rotation speed of the drum up to The motor is controlled so as to rotate the drum at a rotation speed for performing dehydration or dewatering operation when it is determined that the magnitude and position of the unbalanced load is increased as desired at the rotation speed. A centrifugal dewatering device, comprising: 3. The centrifugal dehydrator according to claim 1 or 2, wherein the rotation speed control means determines that the magnitude or position of the unbalanced load is not as desired. The motor is controlled so as to increase the rotational speed of the drum to a rotational speed for determining an unbalanced load again after the drum is once stopped or reduced to a rotational speed close to the stop. Centrifugal dewatering device. 4. The centrifugal dehydrator according to claim 1 or 2, wherein the rotational speed for determining the unbalanced load by the determining means is a balance between the centrifugal force acting on the laundry in the drum and gravity. A centrifugal dewatering device characterized in that the rotation speed is slightly higher than the rotation speed.