JP3049364B2 - Dehydrator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Purpose of the Invention] (Industrial application field) The present invention relates to a dewatering machine taking low noise measures.

(Prior Art) Conventionally, as a dehydrator, a dehydrator / washer and a two-tub type washing machine are known. For example, in a spin-drying washing machine, at the time of spin-drying, a rotary tub serving as a spin-drying tub is rotated based on rotation of a motor to spin-dry laundry.

(Problems to be Solved by the Invention) By the way, at the time of spin-drying, there is a problem that vibration is generated by the washing machine. However, conventionally, in a washing machine, since the motor is controlled to start at a high rotation speed from the beginning of spin-drying, when the unbalanced vibration occurs due to the distribution state of the laundry in the rotating tub, it is considerably large. Noise is generated. In this case, this type of washing machine includes a swing detection lever that detects abnormal vibration of the spin-drying tub and a detection switch that is operated by the lever. When the unbalanced vibration occurs, the motor is stopped to release the motor. The rotation of the aquarium is stopped.
However, if the motor is controlled to start up at a high rotation speed from the beginning of the dehydration, the frequency of the vibration of the dehydration tub becomes quite high, and the dehydration operation is frequently stopped.

As a countermeasure, it is conceivable to set the rotational speed of the motor uniquely low. However, in this case, the following problem is expected. That is, depending on the amount of the laundry (substance to be dehydrated) and the distribution of the laundry in the rotating tub, it is conceivable that even if the rotation speed of the motor is increased, no large vibration is caused. In this case, increasing the rotation speed of the motor is expected to increase the dewatering rate. From this point of view, if the rotational speed of the motor is uniquely reduced to a constant value, a large vibration can be reduced, but there is always an opportunity to improve the dehydration rate, but only a constant dehydration rate is always obtained. There is no problem.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a dehydrator capable of suppressing generation of large vibration and effectively improving a dehydration rate.

[Structure of the Invention] (Means for Solving the Problems) In a dehydrator of the present invention, a dehydration tub is rotated to a target rotation speed based on a rotational drive of a motor to perform a dehydration operation. Current detection means for detecting a current flowing in the motor, a motor driving device for driving the motor so that the rotation speed can be changed, and a predetermined rotation speed at which the rotation speed of the motor is set lower than the target rotation speed at the start of the spin-drying operation. Controlling the motor driving device to start up to a speed, and controlling the motor driving device to increase the rotation speed of the motor when a current value detected by the current detection means at a predetermined rotation speed is equal to or less than a reference value. This is characterized in that control means for performing the control is provided.

(Operation) The motor is rotationally driven by the motor driving device, and the spin-drying operation is performed based on the rotational driving of the motor. In this case, a larger current flows through the motor as the vibration at the time of dehydration increases.

Thus, at the start of the spin-drying operation, the rotation speed of the motor is controlled so as to reach a predetermined rotation speed that is an intermediate rotation speed lower than the target rotation speed. At this predetermined rotation speed, when the current value detected by the current detection means is equal to or less than the reference value, the motor driving device is controlled so as to increase the rotation speed of the motor. Vibration can be reduced and noise generation can be reduced. When the detected current value is equal to or less than the reference value, that is, when it is determined that no large vibration occurs, the rotation speed of the motor is increased.
The maximum rotation speed that is the target rotation speed within the allowable vibration can be obtained, and the dehydration rate can be effectively increased while suppressing noise due to vibration.

Embodiment An embodiment of the present invention will be described below with reference to the drawings.

First, FIG. 4 shows a washing machine for both dehydration.
A water receiving tank 2 is provided in the outer box 1, and a rotating tank 3 as a dewatering tank is provided in the water receiving tank 2. In addition, a container-shaped stirring body 4 is disposed inside the rotary tank 3. A motor 5 composed of a three-phase DC brushless motor is provided at the outer bottom of the water receiving tank 2, and a mechanism 6 having a speed reduction mechanism and the like is provided. The mechanism unit 6 reduces the rotation of the motor 5 during the washing operation and transmits the rotation to the stirring body 4 during dehydration, and transmits the rotation to the rotating tub 3 and the stirring body 4 during dehydration. A drain valve 7 is provided in a drainage passage from the water receiving tank 2, and an air trap 8 is formed at the bottom of the water receiving tank 2. The water level sensor 10 is connected. This water level sensor
Reference numeral 10 denotes a rear part of the upper cover 12 together with the water supply valve 11, and an operation part 13 is disposed at a front part of the upper cover 12.

Next, FIG. 1 shows an electrical configuration. The current detecting means 14 includes a current transformer, and is provided so as to detect a current flowing through the motor 5. The detection result (detection current value) of the current detection means 14 is given to the control circuit 15. The control circuit 15 is a control means, includes a microcomputer, and stores a program for a washing operation control and a dehydration operation in an internal memory. And this control circuit 15
Controls the drain valve 7, the motor driving device 18, and the display 19 based on the input from the various switches 16 and the input from the current detecting means 14 according to the dehydration control program.

The motor driving device 18 energizes the drive coil of the motor 5 at an appropriate energizing timing based on the position detection signal from the position detection element 5a of the motor 5, and detects the position from the position detection element 5a. Motor 5 from signal
And the applied voltage is adjusted so that the required rotation speed is obtained.

Now, the operation of the above configuration will be described with reference to FIGS. 2 and 3 together with the control function of the control circuit 15. FIG. 3 shows a current change characteristic according to the degree of occurrence of unbalance vibration. In the figure, a characteristic line A shows a current change characteristic when there is no unbalanced vibration, a characteristic line B shows a current change characteristic when a small unbalanced vibration occurs, and a characteristic line C shows a large unbalanced vibration. This shows the current change characteristics in the case of performing the above. As you can see from the figure,
A larger current flows through the motor 5 as the vibration during dehydration is larger.

Now, when the dehydration operation is started, as understood from FIG. 2 showing a control flowchart of the control circuit 15, the control circuit 15 controls the motor drive control device 18 to change the rotation speed of the motor 5 to a predetermined rotation speed. 70 in terms of the rotation speed of the rotating tank 3
Start-up control is performed so as to be 0r.pm (step S1).
In this embodiment, the maximum rotation speed which is the target rotation speed is set to 1000 rpm. This folding and position detecting element 5a
Based on the position detection signal from, feedback control is performed so as to be 700 rpm as described above. This rotation speed 700 rpm is a rotation speed at which no imbalance vibration is expected to occur in the rotary tank 3. Then, at the start of the dehydration operation (third
From indicated by "t _1") at a predetermined time Tk elapsed time t ₂ in FIG,
Read the detected current value from the current detecting means 14 (step
S2). For the predetermined time Tk, the rotation speed of the motor 5 is 700 rpm.
Is set longer than the time required to reach, and therefore, at the time of reading the detected current value, it has already risen to 700 rpm.

Next, it is determined whether or not the detected current value is equal to or less than the reference value “b” (Step S3). As for the reference value “b”, as shown in FIG. 3, when the unbalanced vibration does not occur in the rotary tank 3 at the detected current value reading time point t ₂ (see the characteristic line A), The value becomes “a” and a small unbalanced vibration occurs (characteristic line B
), The current value becomes “b”, and when a large unbalanced vibration occurs (see the characteristic line C), the current value becomes “c”. The fact that the detected current value is equal to or smaller than "b" means that it is expected that the unbalanced vibration is small, and that the unbalanced vibration disappears even after the rotation speed of the motor 5 is increased (so-called unbalanced riding). . If the detected current value is equal to or less than the reference value “b”, the rotation speed of the motor 5 is
The motor drive device 18 is controlled so as to start up to 800 rpm (step S4).

Then, read the detected current value from the current detection means 14 again at the time t ₃ when the time is set from the time t ₂ of the above-described Th has elapsed (step S5), and the detected current value is determined value for the no vibration "a" or less Is determined (step S6),
If "a" or less, it is determined that there is no unbalanced vibration, and the motor driving device 18 is controlled so that the rotation speed of the motor 5 is increased to the maximum rotation speed of 1000 rpm in terms of the rotary tank 3 ( Step S7). And if elapsed 10 minutes from the time t ₂ (determined at step S8), and stops the motor 5 driving (step S9) and ends the dewatering operation.

In step S6, if the detected current value is not less than the determination value “a”, that is, if it is less than the reference value “b”, the motor 5 is kept at 800 rpm in terms of the rotating tub 3 at the time. maintaining the t ₃ 7 min (step S10), and further after the motor 5 was maintained increasing Hayashi 5 minutes this in the rotating tub 3 basis until 1000 rpm (step S11, S12), and stops driving the motor 5 (Step S13) to end the dehydration operation.
The purpose of maintaining the above 7 minutes at 800 rpm is that the rotation speed is 800 rpm.
It is expected that the unbalanced vibration will disappear if the condition is continued for further 7 minutes. Therefore, in the dehydration operation at 1000 rpm performed after the lapse of 7 minutes, the unbalanced vibration does not occur. Dehydration is performed.

Note that the detection current value determination at the above-described time point t2 (Step S
In 3), if the value is not smaller than the reference value “b”, it is determined in step S14 whether or not the value is smaller than the large vibration determination value “c”. (If the value exceeds the reference value “b” and is equal to or less than “c”), it is determined that it will take time for the unbalanced vibration to disappear, and the motor 5 is further driven for 10 minutes until the rotation speed at this time remains at 700 rpm. Then, the drive of the motor 5 is stopped (step S16), and the spin-drying operation is terminated. If it is not less than or equal to the large vibration determination value "c" in step S14, that is, if it exceeds the large vibration determination value "c", the drive of the motor 5 is stopped to perform imbalance correction work as appropriate. (Step S17) to end the dehydration operation.

As can be seen from the above, the motor 5 is connected to the motor driving device 18.
, And the rotation tub 3 is rotated based on the rotation of the motor 5 to perform a spin-drying operation. In this case, a larger current flows through the motor 5 as the vibration at the time of dehydration increases.

According to the present embodiment, at the start of the spin-drying operation, the rotation speed of the motor 5 reaches a predetermined rotation speed (a rotation speed at which no unbalanced vibration is expected to occur, that is, 700 rpm in terms of the rotary tub 3). Is controlled as follows. Therefore, a large unbalanced vibration does not normally occur. As a result,
Large vibrations that occur at the start of dehydration can be reduced,
Noise generation can be reduced.

At this predetermined rotational speed, the current detecting means 14
When the detected current value is equal to or less than the reference value “b”, the motor driving device is configured to increase the rotation speed of the motor 5.
Since the control of 18 allows the rotation speed of the motor 5 to be increased when it is determined that no large vibration occurs, the highest rotation speed within the allowable vibration range can be obtained. The dehydration rate can be effectively increased while suppressing noise due to vibration.

Further, according to the present embodiment, since the current flowing through the motor 5 is detected and the magnitude of the vibration is determined based on the current value, the vibration at the time of dehydration can be measured by a machine such as a combination of a swing detection lever and a detection switch. Vibration can be detected linearly, finer rotation speed control can be performed, and the structure can be simplified as compared with the case of detection by the target detection means.

In the above-described embodiment, the present invention is applied to the washing machine for both dehydration, but the present invention may be applied to a two-tub washing machine.

In addition, the present invention is not limited to the embodiments described above and shown in the drawings, and can be implemented with various modifications without departing from the scope of the invention.

[Effects of the Invention] As is apparent from the above description, the present invention relates to a motor in which a spin-drying tub is rotated to a target rotational speed based on the rotational driving of a motor to perform a spin-drying motion. Current detection means for detecting a current flowing through the motor, a motor drive device for driving the motor so that the rotation speed can be changed, and at the start of the spin-drying operation, reduce the rotation speed of the motor to a predetermined rotation speed set lower than the target rotation speed. Controlling the motor drive device to start up, and controlling the motor drive device to increase the rotation speed of the motor when a current value detected by the current detection means at a predetermined rotation speed is equal to or less than a reference value. Means, which makes it possible to eliminate the generation of large vibrations, reduce the generation of noise, and furthermore, In this case, the dewatering rate can be effectively improved, and further, the rotation speed can be finely controlled, and the structure can be simplified.

[Brief description of the drawings]

1 shows an embodiment of the present invention, FIG. 1 is a block diagram of an electric configuration, FIG. 2 is a flowchart showing the control contents of a control circuit, and FIG. 3 is a relationship between an unbalanced vibration occurrence state and a current change. FIG. 4 is a vertical sectional side view of the washing machine. In the figure, 3 is a rotary tank (dehydration tank), 4 is a stirring body, 5 is a motor, 14 is a current detecting means, 15 is a control circuit (control means), 18
Is a motor driving device.

Continuation of the front page (56) References JP-A-1-230391 (JP, A) JP-A-62-117991 (JP, U)

Claims (1)

(57) [Claims] 1. A dewatering operation in which a dehydration tub is rotated to a target rotation speed based on a rotational drive of a motor, wherein current detection means for detecting a current flowing through the motor, A motor driving device for driving the rotation speed changeable, and controlling the motor driving device to start the rotation speed of the motor to a predetermined rotation speed set lower than the target rotation speed at the start of the spin-drying operation. A dehydrator comprising: control means for controlling the motor driving device so as to increase the rotation speed of the motor when a current value detected by the current detection means at a rotation speed is equal to or less than a reference value.