JPH11309293A - Washing machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a washing machine of detecting vibration of drum with simple structure and low cost and reducing vibration of drum during dehydrating process. SOLUTION: It is constructed from a tub 2, a magnet 8 which is mounted on the tub 2, a water-level detection means 10 which has a coil and a control means 14 which acquires the output signal of the water-level detection means and based on it, detects the vibration of tub 2 and controls the washing action. When a generated voltage of coil is higher than the ceiling value, the control means reduces the revolution of rotation means and when the voltage is lower than the lower limit value, it increases the revolution of rotation and the rotation means increase and decrease the voltage or frequency of the motor power. And the control means corrects the generated voltage of coil or the ceiling value according to the washing object weight.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a washing machine and, more particularly, to a method for detecting a vibration of a washing tub and a method for controlling the rotation of a washing tub.

[0002]

2. Description of the Related Art Conventional methods for detecting vibration of a washing tub in a washing machine include a method of detecting displacement of the tub by attaching an ultrasonic sensor or a photoelectric sensor to an outer frame around the tub, an acceleration sensor, a strain gauge, and the like. A method of detecting the acceleration of the tank by attaching it to a tank or a hanging rod has been devised. Further, a method has been devised in which a magnetic body is attached to a tank, a coil is provided on an outer frame near the tank, and vibration of the tank is detected based on a change in inductance of the coil.

Further, as an example in which a water level sensor of a washing machine also has a function of detecting vibration of a tub, there is a washing machine described in Japanese Patent Application Laid-Open No. 9-94380. This is provided with a first magnetic body and a second magnetic body inserted into the core of the coil of the water level sensor. Both magnetic bodies are movable, and the first magnetic body has a structure in which the insertion amount changes according to the water level of the washing tub. Second
Is connected to the upper end of a suspension (suspension rod) that suspends the washing tub from the outer frame, and has a structure in which the insertion amount changes according to the vibration of the suspension rod. When the insertion amount of the first magnetic body changes according to the water level, the inductance of the coil changes accordingly. When the insertion amount of the second magnetic body changes according to the vibration of the suspension, the inductance of the coil also changes accordingly. Therefore, by measuring the inductance of the coil, it is possible to detect both the water level of the washing tub and the vibration of the hanging rod, and it is not necessary to add a new coil or the like for detecting the vibration.

[0004]

In each of the methods described in the first half of the prior art, it is necessary to provide a special means for detecting vibrations, which is costly.

In the method described in JP-A-9-94380, the vibration directly transmitted to the second magnetic body is the vibration of the suspension, not the vibration of the tank. Since the vibration of the tank and the vibration of the suspension are not completely proportional, the vibration of the tank cannot be accurately measured from the inductance of the coil. In addition, a mechanism for transmitting the vibration of the suspension to the second magnetic body is required, which requires a cost.

SUMMARY OF THE INVENTION An object of the present invention is to provide a washing machine which detects the vibration of a washing tub at a low cost with a simple structure and reduces the vibration of the washing tub based on the detected information, especially in a spin-drying process. .

[0007]

A first aspect of a washing machine according to the present invention comprises a water level detecting means for detecting a water level in a washing tub, wherein the water level detecting means changes an inductance according to a water level in the washing tub. And an oscillation circuit that generates an electric signal corresponding to the inductance. In a second aspect of the washing machine according to the present invention, a magnet is provided above the washing tub near the coil. Both modes include control means for controlling the washing operation. The control means can obtain either the output signal of the oscillation circuit or directly obtain the electric signal generated in the coil.

That is, in the first embodiment, when the washing tub is in a water-filled state, when the washing tub vibrates, the water level rises and falls, and the water level fluctuates. Since the width of the fluctuation is approximately proportional to the amplitude of the washing tub, the control means can calculate the amplitude of the washing tub from the fluctuation of the output signal of the oscillation circuit.

In the second aspect, particularly when the washing tub vibrates in the dehydrating step, the magnet provided in the washing tub vibrates. As a result, an induced voltage is generated in the coil by electromagnetic induction. If the oscillation period is constant, the induced voltage increases as the amplitude increases, so that the control means can calculate the amplitude from the voltage generated by the coil. In the dehydration step, the control means can control the rotation of the washing tub while measuring the amplitude of the washing tub. Therefore, when the amplitude is excessive, the rotation speed of the washing tub is reduced to reduce the rotation of the washing tub. Excessive vibration can be prevented. Since the control means can also obtain the output signal of the oscillation circuit, the function of detecting the water level by the water level detection means is not impaired.

As described above, it is possible to detect both the water level of the washing tub and the vibration by simply adding one magnet to the existing water level detecting means in the washing machine.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a washing machine according to the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing a configuration of an example of a washing machine according to the present invention. The inner tub 1 is a cylindrical tub whose upper part is open, stores laundry, and has a number of dehydration holes on the side surface. It is rotatable. Outer tank 2 is inner tank 1
Is a cylindrical tank whose top is open and contains water. Since the inner tank 1 has the dehydration holes, the water levels of the inner tank 1 and the outer tank 2 are the same. The rotary blade 3 is a rotatable stirring blade provided at the center of the bottom of the inner tub 1, and generates a water flow for washing. The rotating mechanism 4 includes the inner tank 1 and the rotating blades 3.
And a motor, a gear, and an electromagnetic clutch. It is attached to the lower part of the outer tub 2.
The suspension rod 5 is a metal rod that suspends the outer tub 2 from above, and supports the lower part of the outer tub 2 with a spring.

The rotating shaft 6 is composed of both the rotating shaft of the inner tub 1 and the rotating shaft of the rotary wing 3, and is connected to the rotating mechanism 4. The rotating mechanism 4 selects and rotates one of the two rotating shafts with a clutch, and does not rotate both rotating shafts at the same time. The outer frame 7 is a plate surrounding the side surface of the washing machine, and has a substantially rectangular parallelepiped shape.

It supports the hanging bar 5 at the upper four corners.
The magnet 8 is a permanent magnet attached to the upper part of the outer tub 2, and is located substantially directly below the water level sensor 10. The first air chamber 20 is a cylindrical air chamber provided at a lower portion outside the outer tub 2, and has a structure communicating with the outer tub 2 at the lowermost portion. That is, the water in the outer tub 2 passes through the communicating portion, enters the first air chamber 20 from below, and pushes up the air therein.

The air pipe 9 is a vinyl pipe or the like connecting the upper part of the first air chamber 20 and the water level sensor 10. The higher the water level of the outer tub 2 is, the higher the water pressure at the bottom of the tub is, and the stronger the force for pushing up the air in the first air chamber 20 is, the higher the air pressure in the first air chamber 20 and the air pipe 9 is. Become. That is, the air pipe 9 transmits the water level information of the outer tub 1 to the water level sensor 10 as air pressure information.

The water level sensor 10 is a sensor for converting the water level of the outer tub 1 into an electric quantity such as inductance, and has a structure in which the electric quantity changes according to the change in the air pressure. The changeover switch 11 is a switch for selecting and connecting the output terminal of the water level sensor 10 to the amplification and rectification circuit 12 or to the oscillation circuit 13, and the control is performed by the control unit 14. The amplification and rectification circuit 12 is a circuit that amplifies an AC signal, performs rectification and smoothing, and outputs the signal as a DC signal. The oscillation circuit 13 is a circuit that generates an AC signal by being connected to the water level sensor 10, and the frequency of the AC changes according to the electrical amount of the water level sensor 10.

The control unit 14 is a circuit for inputting a signal, performing an arithmetic operation, outputting a control signal, and controlling a washing operation in accordance with a program recorded therein, and is a commercially available one-chip microcomputer or the like. It has an input / output terminal for digital signals, an input terminal for analog signals, and an A / D (analog-to-analog) for converting the analog signals into digital signals.
Digital) converter. The control unit 14 obtains an output signal of the amplification and rectification circuit 12 from an input terminal of the analog signal, and obtains an output signal of the oscillation circuit 13 from an input terminal of the digital signal.

The drive circuit 15 acquires a control signal from the control unit 14 and generates a power for operating the rotation mechanism 4 and a power for opening and closing the water supply valve 17 and the drain valve 19 based on the control signal. It is. The water supply pipe 16 is a water supply pipe that is connected to a water supply port such as a water supply and supplies water to the inner tank 1 and the outer tank 2. The drain pipe 18 is a water pipe connected to the bottom of the outer tank 2 and draining water in the inner tank 1 and the outer tank 2. The water supply valve 17 and the drainage valve 19 are on-off valves provided in the middle of the water supply pipe 16 or the drainage pipe 18, respectively.
The opening / closing operation is performed by the electric power from 5.

FIG. 2 is a sectional view showing an example of the structure of the water level sensor 10. The coil 101 is a cylindrical coil having multiple windings, and a magnetic body 102 is inserted at the center. coil
One end of 101 is connected to the changeover switch 11 and the other end is commonly grounded. The magnetic body 102 is a bar-shaped magnetic body that stands upright at the center of the film surface 103 and is supported from above by a spring 105. This means that the amount of insertion into the coil 101 changes according to the height of the film surface 103.

The film surface 103 is a flat thin film that partitions the inside of the second air chamber 104 up and down, and is movable up and down. The lower part of the second air chamber 104 is connected to the air pipe 9.
In the second air chamber 104, the portion below the membrane surface 103 does not allow air to flow into and out of the portion other than the air pipe 9. When the water level in the outer tub 2 rises, the air in the air pipe 9 is pushed up and sent into the second air chamber 104, whereby the membrane surface 10
3 rises. Then, the insertion amount of the magnetic body 102 into the coil 101 increases.

Conversely, when the water level falls, the air in the air pipe 9 is drawn back, the air in the air chamber 104 is exhausted, and the membrane surface 103 descends, and the insertion amount of the magnetic body 102 into the coil 101 is small. Become. Since the inductance of the coil 101 increases as the insertion amount of the magnetic body 102 increases, the inductance of the coil 101 changes depending on the water level of the outer tub 2 as a result.

FIG. 3 is a circuit diagram showing an example of the oscillation circuit 13. It is composed of an amplifying element, a resistor, and a capacitor, and generates an AC signal of a square wave by being connected to the coil 101. The frequency of the signal changes according to the inductance of the coil 101. Therefore, the inductance changes according to the water level of the outer tub 2, and the higher the water level, the higher the inductance and the lower the frequency. The signal is obtained by the control unit 14 as a digital signal. The control unit 14 calculates the water level of the outer tub 2 by measuring the period of the signal.

Next, a description will be given of a method of detecting vibration of the outer tub 2 in a water-filled state based on fluctuations in the water level of the outer tub 2. In this case, the control unit 14 connects the water level sensor 10 to the oscillation circuit 13 with the changeover switch 11 set to the side b.

When the inner tub 1 is rotated with the laundry and water in the inner tub 1, the inner tub 1 and the outer tub 2 vibrate back and forth and right and left if the laundry is offset. The greater the offset, the greater the amplitude of the vibration. 4 and 5 are examples of the lateral displacement of the outer tub 2 and the temporal change of the oscillating frequency of the oscillation circuit 13 when the inner tub 1 is rotated in a state where laundry and water are put. is there. In both figures, the amount of laundry and the water level are the same. The start of energization of the motor of the rotation mechanism 4 is set to 0 second, and the energization is stopped after 16 seconds. Therefore, the rotation speed of the inner tank 1 monotonically increases for the first 16 seconds, and thereafter decreases.

FIGS. 4 and 5 show a case where the deviation of the laundry is large and a case where the deviation is small, respectively. Since the water surface also vibrates due to the vibration of the inner tank 1, the water level fluctuates finely. Therefore, the oscillation frequency also fluctuates finely. The greater the deviation of the laundry, the greater the amplitude of the outer tub 2 and the greater the variation in the frequency. However, as the rotation speed of the inner tub 1 increases, the speed of the rotating water flow in the outer tub 2 increases. As the speed of the water flow increases, the water in the first air chamber 20 is drawn into the outer tub 2 and the air pressure in the chamber decreases, whereby the inductance of the coil 101 decreases and the frequency increases. . That is, the frequency increases as the number of rotations increases. Therefore, the temporal change of the frequency takes the form of a long-period fluctuation in accordance with an increase or decrease in the number of revolutions + a short-period fluctuation in accordance with the vibration of the outer tub 2.

Next, based on the time change of the frequency, the outer tank 2
An example of a method of extracting only a short-period fluctuation corresponding to the vibration of the trajectory will be described. The frequency is sampled at regular time intervals, and a difference value obtained by subtracting the immediately preceding sample value from each sample value is calculated. More specifically, i
If the second sample value is f (i), the difference frequency Δf (i) = f (i) −f (i−1). 4 and 5 are sampled at intervals of 20 mS from time 0, and the temporal changes of the data obtained as described above are shown in FIGS. 6 and 7, respectively.

The one in which the fluctuation width of the short cycle is large (FIG. 4)
The variation width of the differentiated frequency is also large (FIG. 6). Maximum amplitude (maximum value of displacement-minimum value) of outer tub 2 obtained as a result of performing a number of experiments in which laundry and water were put into inner tub 1 and rotated.
FIG. 8 shows the relationship between the difference and the maximum variation width (maximum value−minimum value) of the frequency that has been differentiated. In a water-filled state, there is a high correlation between the amplitude of the outer tub 2 and the fluctuation width of the frequency. Therefore, if the fluctuation width of the frequency is measured, the amplitude of the outer tub 2 can be calculated. That is, using the water level detection means, the outer tank 2
Vibration can be detected.

Thus, after completion of the washing and rinsing steps,
Before draining, the inner tub 1 is rotated and the amplitude of the outer tub 2 is measured. If the amplitude is large, it is assumed that the deviation of the laundry is large,
An operation for correcting the deviation can be performed immediately. As a result, in the spin-drying process, the possibility of non- spin-drying or excessive vibration due to the offset of the laundry can be reduced.

An example of the operation of measuring the amplitude of the outer tub 2 in the filled state and correcting the deviation of the laundry if the amplitude is large will be described with reference to the flowchart of FIG. explain. When the washing or rinsing step is completed, the control unit 14 initializes a counter for the number of times N of the amplitude measurement of the outer tub 2 to zero. A predetermined upper limit M is set for the number N so that the washing time does not become too long. M is 1
From about 3 at most (u-1). Then, the water in the inner tank 1 and the outer tank 2 is drained to a predetermined water level.

Specifically, the drain valve 19 is opened, and the changeover switch 11 is set to the b side to measure the water level by the above-described method. When the water level reaches a predetermined value, the drain valve 19 is closed. The predetermined water level is, for example, half the height of the inner tank. This is because when the amount of water in the inner tub 1 and the outer tub 2 is large and all the laundry is immersed in water, the offset of the laundry is not reflected in the vibration of the outer tub 2 and, conversely, when the amount of water is small, This is because a water flow for correcting the deviation cannot be generated (above u-2).

The control unit 14 determines that the number of times N is equal to the upper limit M
Is determined (u-3), and if not, the inner tank 1 is rotated for a predetermined time of about 10 to 20 seconds, and the oscillation frequency of the oscillation circuit 13 during the rotation is acquired (u-).
4). Then, based on the fluctuation of the oscillation frequency, the amplitude of the outer tub 2 is calculated by the above method (u-5). When the amplitude is equal to or larger than the predetermined threshold value (u-6), the control unit 14 rotates the rotor 3 in a predetermined pattern to generate a water flow for correcting the deviation of the laundry. An example is shown later in FIG.
(U-7). Then, the control unit 14 increases the number N by 1 (u-8), and returns to the determination of the number N (u-3). If the amplitude is less than the threshold, (u−
6) Or, if the number of times reaches the upper limit M, (u−
3), the controller 14 shifts to a dehydration step (u-9).

With respect to the threshold value, both (1) the upper limit amplitude at which dehydration is not disabled during dehydration, and (2) the relationship between the amplitude in a filled state and the amplitude during dehydration are experimentally obtained. And set based on these.

Here, with respect to an example of the rotation pattern of the rotary wing 3 for generating a water flow for correcting the deviation of the laundry, the control unit 14 controls the rotation mechanism 4 to perform the rotation.
This will be described with reference to FIG. The control unit 14 repeatedly inverts the rotary wing 3 at a constant short cycle. Here, the voltages applied to the motor for rotating the rotor 3 clockwise and counterclockwise are respectively
E, -E. In the example of the figure, 0.7 is used for the first 20 seconds.
The application of E, 0 (off), -E, 0 is repeated at intervals of seconds.
0.5 second interval for next 20 seconds, 0.4 for last 20 seconds
The same application is repeated at intervals of seconds. Even in the state of 0 (off), the rotor 3 rotates while attenuating due to inertia.

According to this embodiment, after the washing or rinsing step is completed, before shifting to the dehydrating step, the deviation of the laundry is determined, and if the deviation is large enough to impede the dehydration, immediately. Since it is possible to perform the operation to correct the deviation, it becomes impossible to dehydrate at the time of dehydration, or to prompt the user's response,
The possibility of performing an operation of supplying water again to correct the deviation can be reduced. Therefore, the average washing time and the amount of water supply can be reduced.

A method for detecting the vibration of the outer tub 2 based on the induced voltage generated in the coil 101 of the water level sensor 10 by the vibration of the magnet 8 attached to the outer tub 2 will be described below. In this case, the control unit 14 connects the water level sensor 10 to the amplification and rectification circuit 12 with the changeover switch 11 set to the a side.

The magnet 8 is provided on the water level sensor 10 above the outer tank 2.
When the magnet 8 vibrates with the vibration of the outer tub 2, the coil 101 of the water level sensor 10
, An induced voltage is generated. In the dehydration step, the water in the inner tub 1 and the outer tub 2 is drained, so that even if the outer tub 2 vibrates, the water level does not fluctuate. Detection is not possible. FIG. 9 shows a temporal change of the displacement of the outer tub 2 and the coil 10 in the dewatering step.
1 is an example of a temporal change of a voltage obtained by amplifying and rectifying and smoothing the generated voltage of No. 1 by the amplifying and rectifying circuit 12.

FIG. 10 is an enlarged view of FIG. 9 from 110 seconds to 112 seconds. The dehydration start time is set to 0 second and 12
After 0 seconds, the power supply to the motor is cut off. The rotation speed of the inner tub 1 monotonically increases for about 90 seconds from the start of dehydration, becomes substantially constant thereafter, and monotonically decreases after the power is cut off. The faster the vibration of the magnet 8, the higher the induced voltage generated in the coil 101. Therefore, immediately after the start of dehydration, the vibration is slow due to the low rotation of the inner tub 1, and almost no voltage is generated in the coil 101.
Therefore, if the rotation speed of the inner tank 1 becomes higher than a certain level, the vibration of the outer tank 2 can be detected by the voltage generated by the coil 101.

The maximum amplitude (maximum value of the displacement-minimum value) of the outer tub 2 and the amplified, rectified and smoothed coil obtained as a result of conducting a number of experiments of washing and dehydrating a certain amount of laundry. 1
FIG. 11 shows the relationship with the maximum value of the generated voltage 01. The amplitude and the generated voltage are measured during a period when a sufficient time has elapsed after the start of dehydration and the number of revolutions of the inner tub 1 has become substantially constant (hereinafter, this period may be referred to as a steady state of dehydration). It is. In the dehydration steady state, the amplitude of the outer tub 2 and the coil 10
1 has a high correlation with the generated voltage, and therefore, by measuring the generated voltage, the amplitude can be calculated. That is, the magnet 8
The vibration of the outer tub 2 can be detected using the coil 101 of the water level sensor.

Hereinafter, a method in which the control unit 14 controls the rotation of the inner tub 1 based on the voltage generated by the coil 101 in the dehydration step will be described.

In the steady state of dehydration, a certain limit value is set for the amplitude of the outer tub 2 in order to prevent excessive vibration and noise. For example, let d1 = 28 mm shown in FIG. The voltage corresponding to d1, which is obtained from the relationship between the amplitude of the outer tub 2 and the voltage generated by the coil shown in the figure, is defined as V1, and this is the upper limit of the generated voltage. In the dehydration step, the control unit 14 controls amplification,
While obtaining the output voltage of the rectifier circuit 12, the rotation speed of the inner tank 1 is controlled so that the voltage does not exceed the upper limit.

One specific example will be described with reference to FIG. A lower limit V2, which is slightly lower than the upper limit V1, is provided for the voltage V generated by the coil 101, and the controller 14 determines that V is equal to V1 and V2.
The rotation of the inner tank 1 is controlled so as to fall within the range. After the start of dehydration, V monotonically increases as the rotation speed of the inner tub 1 increases. When the amplitude of the outer tank 2 is large and V reaches the upper limit V1,
The control unit 14 stops supplying power to the motor of the rotation mechanism 4 (OFF). As a result, the rotation speed of the inner tank 1 decreases, and the outer tank 2
Decreases, and V also decreases. When V falls to the lower limit V2, the control unit 14 restarts energization to the motor (ON). When V again reaches the upper limit V1, the control unit 14 stops energizing the motor. The controller 14 repeats the above-described energization / interruption control until the dehydration time ends.

The details of the above control method will be described with reference to the flowchart of FIG. 13 showing the operation of the control unit 14 in the dehydrating step. At the start of dehydration, the control unit 1
4 switches the clutch so that the rotating force of the motor is transmitted to the inner tank 1 in the rotating mechanism 4, and starts energizing the motor (s-1). During the period from the start to the end of the dehydration step, the dehydration control unit 14 acquires the output voltage V of the amplification and rectification circuit 12 at a constant cycle. When V rises and reaches the predetermined upper limit V1 (s-2), the control unit 14 stops energizing the motor (s-3). When V decreases and reaches the predetermined lower limit V2 (s-4), the control unit 14 restarts energization to the motor (s-5). When V rises and reaches V1 again (s
-2), the controller 14 cuts off the power supply to the motor.

The amplitude of the outer tub 2 is small, and V is V1 during dehydration.
Does not reach (s-2), the control unit 14 continues to supply power to the motor until the spin-drying time ends or an abnormality (error) occurs during spin-drying. When this occurs (s-7), the power supply to the motor is stopped and dehydration is stopped (s-8). Examples of abnormalities during dehydration include:
The case where the user opens the lid, the case where the amplitude of the outer tub 2 is excessive and the outer tub 2 collides with the outer frame 7, and the like.

Also, when the user performs a dehydration stop operation during the dehydration, the control unit 14 immediately stops the dehydration. Similarly, when V once reaches V1, and when the dehydration time ends or an abnormality occurs while being kept between V1 and V2, (s
-7), the control unit 14 stops the dehydration (s-8).

According to the present embodiment, excessive vibration of the outer tub 2 during the dehydration steady state can be prevented by only turning on and off the motor without requiring any means for varying the voltage of the motor, and the generated voltage is reduced. Since the rotation of the inner tub 1 is controlled so as not to fall below the lower limit, the number of rotations of the inner tub 1 becomes too small, and the effect of dehydration is not unnecessarily impaired.

Next, another method of controlling the rotation of the inner tank 1 by the control unit 14 in the dehydrating step will be described with reference to FIG. Similarly to the above method, the upper limit of the voltage V
1, a lower limit V2 is provided. At the start of dehydration, the control unit 14 applies the voltage E0 to the motor. When the V reaches V1, the control unit 14 reduces the voltage E applied to the motor to a constant value ΔE1.
Only to reduce. As a result, the rotational speed of the motor slightly decreases, and V also decreases. The control unit 14 monitors V every predetermined short time, and if V is still equal to or more than V1 without sufficiently decreasing E, E is further reduced by ΔE1.

The control section 14 repeats this operation until V becomes equal to or less than V1. When V decreases to V2 as a result of reducing E, the control unit 14 determines that E is excessively reduced, and increases E by a constant value ΔE2 equal to or less than ΔE1. As in the case of reducing E, the control unit 14 monitors V. If V is still equal to or less than V2, E is further increased by ΔE2.

As described above, the control unit 14 determines that V is V1
Is reached, E is decreased by ΔE1, and when V is decreased to V2, the control of increasing E by ΔE2 is repeated. Thereby, the rotation speed of the inner tank 1 is settled to a value such that V falls between V1 and V2.

The details of the above control method will be described with reference to the flowchart of FIG. 15 showing the operation of the control unit 14 in the dehydration step. Control unit 14 at the start of dehydration
Applies a voltage E0 to the motor. When the amplitude of the outer tub 2 increases and V reaches V1 (t-1), the control unit 14 reduces the voltage E applied to the motor by ΔE1 (t-2).
Then, after a short period of time, the control unit 14 acquires V again (t-3). If it is still V1 or more (t-4), E is further reduced by ΔE1 (t-5). Until V becomes less than V1, the control unit 14 acquires V after a predetermined short time (t−
6), determination of V1 or more (t-4), reduction of E (t-
Repeat 5).

If the dehydration time ends or an error occurs during this time (t-6), the controller 14 stops the dehydration (t-
15). When V decreases to V2 as a result of reducing E (t-7), the control unit 14 increases E by ΔE2 (t-8). Then, after a fixed short period of time, the control unit 14 (t
-9) If V is equal to or less than V2 (t-10), E is further increased by ΔE2 (t-11). Until V exceeds V2, the control unit 14 waits for a fixed short time (t-12).
The following judgment (t-10) and the increase of E (t-11) are repeated.

If the dehydration time ends or an error occurs during this time (t-12), the controller 14 stops the dehydration (t-12).
-15). If V exceeds V2 (t-10), the control unit 14 returns to determining whether V is equal to or greater than V1 (t-1). If the amplitude of the outer tub 2 is small and the dehydration time ends or an abnormality occurs without V reaching V1 during the dehydration (t-13), the control unit 14 stops the dehydration (t-15).

After V has once reached V1, the control unit 14
If the dehydration time ends or an error occurs while V stays between V1 and V2, the rotation speed is controlled by (t−
14 or t-13), the control unit 14 stops the dehydration.

According to this embodiment, the means for increasing or decreasing the motor voltage is required. However, by continuously rotating the motor during the dehydration process, electrical and mechanical noise caused by repetition of turning on and off the motor is achieved. And the anxiety of the user can be eliminated. In this embodiment, the method of increasing or decreasing the voltage of the motor has been described. The effect is obtained.

Hereinafter, the weight of the laundry in the inner tub 1 and the coil 1
A method of correcting the voltage according to the relationship between the generated voltage and the weight and the weight will be described.

First, the relationship between the weight of the laundry and the voltage generated by the coil will be described with reference to FIGS.
As shown in FIG. 1, the outer tub 2 is a hanging rod 5 having a spring at a lower portion.
Supported by Therefore, as the weight of the laundry in the inner tub 1 increases, the amount of deformation of the spring increases, and the outer tub 2
Sinks more. For this reason, the magnet 8 attached to the upper part of the outer tank 2 and the coil 101 in the water level sensor 10 are further isolated. FIG. 18 shows an example of the relationship between the weight of the laundry in the inner tub 1 and the distance from the magnet 8 to the coil 101.

The weight of the laundry indicates both the weight including moisture at the time of steady dehydration and the weight at the time of drying. The former is about twice the latter. Since the amount of deformation of the spring of the hanging bar 5 is proportional to the force applied by the weight, the relationship between the weight and the distance becomes linear. The weight, the distance, and the coil 10
FIG. 19 shows an example of the relationship with the generated voltage of No. 1. If the amplitude and cycle of the vibration of the outer tub 2 are the same, the longer the distance between the magnet 8 attached to the outer tub 2 and the coil 101 becomes, the weaker the magnetic field near the coil 101 becomes. Is low.

Next, an example of a method for detecting the weight of the laundry will be described with reference to FIG. This is a method in which the rotor 3 is rotated at the start of washing and the weight is calculated from the attenuation rate of rotation. The control unit 14 rotates the rotary blade 3 for a predetermined time before supplying water, and then cuts off the power supply to the motor. Then, a voltage generated in the motor is obtained. After the cutoff, the rotation speed of the rotor 3 is attenuated. Since the laundry is put on the rotor 3, the greater the weight of the laundry, the greater the force for suppressing the rotation of the rotor 3, and the faster the attenuation. With the rotation decay, the voltage generated by the motor has a reduced amplitude and a longer period. The greater the weight of the laundry, the higher the amplitude attenuation rate and the higher the cycle increase rate.

Therefore, the control unit 14 measures the cycle from the acquired voltage and calculates the weight of the laundry from the cycle.
The period is measured by repeating the measurement of the time from the zero crossing point of the voltage to the next zero crossing point a fixed number of times. In the example of the figure, three times are set, and T1, T2, T3, U1, U2, and U3 are measured. Then, the weight of the laundry is calculated from the relationship between the cycle and the weight of the laundry obtained experimentally. The controller 14 keeps the weight until the end of the washing.

Next, a method of correcting the voltage generated by the coil 101 according to the weight will be described with reference to FIG. Each time the control unit 14 obtains the voltage, it multiplies this by a correction coefficient corresponding to the weight. The correction coefficient is the reciprocal of the relationship between the weight and the voltage shown in the figure, and is indicated by a dotted line in the figure.
In the figure, the reciprocal is calculated with the generated voltage when the weight is 0 as the reference value = 1. The control unit 14 records and holds in advance the relationship between the weight and the correction coefficient, and when the weight is detected at the start of washing, searches for a correction coefficient corresponding to the weight.

The outer tank 2 shown in FIG. 15 or FIG.
In the operation of measuring the amplitude of the inner tank 1 and controlling the rotation speed of the inner tank 1 based on the amplitude, the control unit 14 multiplies the correction coefficient each time the voltage V is obtained, instead of multiplying the correction coefficient by the upper limit V1 and the lower limit V1 shown in FIG. The magnitude of V may be determined by multiplying the value V2 by the correction coefficient.

According to the present embodiment, the control unit 14 measures the weight of the laundry and corrects the acquired voltage based on the relationship between the weight of the laundry and the voltage generated by the coil 101, which is obtained in advance. Since the amplitude of the outer tub 2 is calculated, no error occurs in the vibration detection due to the difference in the weight of the laundry.

[0062]

As described above, according to the present invention, since the amplitude of the outer tub in the filled state is calculated from the fluctuation range of the water level measured by the existing water level detecting means in the washing machine, special vibration The vibration of the outer tub can be detected without adding any detecting means. Thus, the amplitude of the outer tub is measured after washing and rinsing, and if the amplitude is large, it is possible to immediately start the operation for correcting the bias of the laundry. Therefore, in the dehydration process,
It is possible to reduce the possibility of dehydration failure and excessive vibration due to the offset.

A means for directly obtaining an induced voltage generated in a coil constituting the water level detecting means is provided, a magnet is attached to the outer tank, and an induced voltage generated in the coil is obtained by vibration of the outer tank. Based on this, the amplitude of the outer tank is calculated.
Therefore, the magnet 1 can be used without impairing the function of the existing water level detecting means.
The vibration of the outer tank can be detected even in the drained state by simply adding the individual.

In the dehydration step, the control means controls the rotation of the inner tub while detecting the external vibration. Therefore, when the amplitude of the outer tub is excessively large, the control means reduces the number of rotations to perform the excessive control. Vibration and noise can be prevented.

Further, since the weight of the laundry is detected and the voltage generated by the coil is corrected in accordance with the weight, the voltage varies because the degree of sinking of the outer tub varies depending on the weight. Errors can be eliminated.

[Brief description of the drawings]

FIG. 1 is a block diagram of an example of a washing machine according to the present invention.

FIG. 2 is a sectional view showing an example of a structure of a water level sensor 10 of FIG.

FIG. 3 is a circuit diagram showing an example of an oscillation circuit 13 of FIG.

FIG. 4 is a characteristic diagram showing an example of a temporal change in the amplitude of the outer tank and the oscillation frequency of the oscillation circuit 13;

FIG. 5 is a characteristic diagram showing temporal changes in the amplitude of the outer tank and the oscillation frequency of the oscillation circuit 13;

FIG. 6 is a characteristic diagram in which a change over time of the oscillation frequency in FIG. 4 is differentiated.

FIG. 7 is a characteristic diagram in which a change with time of the oscillation frequency in FIG. 5 is differentiated.

FIG. 8 is a correlation diagram between the maximum amplitude of the outer tank and the maximum fluctuation width of the difference frequency.

FIG. 9 is a control unit 1 for detecting and correcting the deviation of the laundry.
6 is a flowchart showing the operation of FIG.

FIG. 10 is a characteristic diagram illustrating a method of controlling a motor in a deviation correction operation of laundry.

FIG. 11 is a diagram showing an example of an amplitude of an outer tank and a temporal change of a voltage generated by a coil 101.

FIG. 12 is an enlarged view of a partial time section of FIG. 11;

FIG. 13 is a correlation diagram between the maximum amplitude of the outer tank and the voltage generated by the coil.

FIG. 14 is a diagram showing a method of controlling a motor during dehydration.

FIG. 15 is a flowchart showing the operation of the control unit 14 during dehydration.

FIG. 16 is a diagram illustrating a method of controlling a motor during dehydration.

FIG. 17 is a flowchart showing the operation of the control unit 14 during dehydration.

FIG. 18 is a diagram showing the relationship between the weight of laundry and the distance between magnets and coils.

FIG. 19 is a diagram illustrating a relationship between the weight of laundry and a correction coefficient by which a coil generation voltage is multiplied;

FIG. 20 is a diagram showing changes in the number of revolutions of the rotor 3 and the voltage generated by the motor.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Inner tank, 2 ... Outer tank, 3 ... Rotating blade, 4 ... Rotating mechanism, 5 ...
Hanging rod, 6: rotating shaft, 7: outer frame, 8: magnet, 9: air tube,
10: water level sensor, 11: changeover switch, 12: amplification,
Rectifier circuit, 13 oscillation circuit, 14 control unit, 15 drive circuit, 16 water supply pipe, 17 water supply valve, 18 drainage pipe, 1
9: drain valve, 20: first air chamber, 101: coil, 10
2 ... magnetic material, 103 ... film surface, 104 ... second air chamber, 1
05 ... Spring.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI G01H 11/02 G01H 11/02 C

Claims (10)

[Claims] 1. An outer frame surrounding a side surface, an outer tank supported by the outer frame, a rotatable inner tank included in the outer tank, and a rotating blade provided at a bottom of the inner tank; Rotating means for rotating the inner tank and the rotor, water level detecting means for detecting a water level of the outer tank and outputting a signal indicating the same, acquiring the signal, and referring to the signal, the rotating means A washing machine comprising control means for controlling a washing operation including rotation control of the outer tub, wherein the control means measures a vibration of the outer tub based on a temporal change of the water level. 2. A washing machine according to claim 1, wherein said control means rotates said inner tub and measures vibration of said washing tub during said rotation. 3. The apparatus according to claim 2, wherein the control means rotates the rotating blades when the amplitude of the vibration is equal to or greater than a predetermined value, to reduce the deviation of the laundry in the inner tub. And a washing machine. 4. An outer frame surrounding the side surface, an outer tank supported by the outer frame, a rotatable inner tank encased in the outer tank, and a rotating blade provided on a bottom of the inner tank. A rotating means for rotating the inner tank and the rotary blades, an upper cover provided on the outer frame, having an opening above the inner tank, and detecting a water level of the outer tank and outputting a signal indicating this. Water level detecting means to be output, a magnet attached to the upper part of the outer tank, a coil provided in the upper cover and near the magnet, an output signal of the water level detecting means, and a voltage generated by the coil are obtained. A control means for controlling the washing operation including the rotation control of the rotating means with reference to these, and the control means measures the vibration of the washing tub based on the generated voltage. A washing machine characterized by the following. 5. The washing machine according to claim 4, wherein said coil is a component of said water level detecting means. 6. A washing machine according to claim 4, wherein said control means controls the number of revolutions of said rotating means so that the voltage generated by said coil does not exceed a predetermined upper limit value. 7. The control device according to claim 6, wherein the control means controls the rotation speed of the rotating means so that the voltage generated by the coil falls between the upper limit value and a predetermined lower limit value less than the upper limit value. A washing machine characterized by being controlled. 8. The control device according to claim 7, wherein the control means reduces the number of rotations of the rotating means when the voltage generated by the coil exceeds the upper limit value, and reduces the rotation speed when the voltage falls below the lower limit value. A washing machine characterized by increasing the number. 9. The apparatus according to claim 6, wherein said rotating means comprises a motor and a mechanism for transmitting rotation of said motor, and said control means controls a voltage or frequency of a power supply of said motor. A washing machine characterized by increasing or decreasing the number of rotations of the rotating means. 10. The washing machine according to claim 4, further comprising a weight detecting means for detecting the weight of the laundry in the inner tub, wherein the control means acquires the weight of the laundry detected by the weight detecting means. A washing machine wherein the voltage generated by the coil or the upper limit value is corrected accordingly.