JP3071042B2 - Dehydration equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dehydrator applied to, for example, a fully automatic washing machine.

[0002]

2. Description of the Related Art Conventionally, a fully automatic washing machine capable of automatically performing a series of washing operations including a washing step, a rinsing step, and a dehydrating step has been used. In such a washing machine, the amount of the laundry is detected in advance before the washing process, and the washing time, the rinsing time, and the dehydration time are automatically set in accordance with the amount. The above-described series of washing operations proceeds according to the automatically set times. That is, the dehydration time is set according to only the amount of the laundry.

[0003]

In the above-described washing machine, the spin-drying time is set to be long when the amount of laundry is large, and to be short when the amount of laundry is small. That is,
Dehydration time depends only on the amount of laundry. However, depending on the type of laundry, drainage is good even if the amount is large, and drainage is poor even if the amount is small. That is, in the above-described conventional technology in which the dehydration time is set only according to the amount of the laundry, depending on the type of the laundry,
Dehydration may not be performed properly, such as when the dehydration time is too long and the laundry is tightly wrinkled, or too short and the dehydration is insufficient.

[0004] Accordingly, an object of the present invention is to provide a dehydrating apparatus capable of performing appropriate dehydration according to the type of the material to be dehydrated.

[0005]

According to the present invention, there is provided a dehydrating apparatus for accommodating an object to be dehydrated, a motor for rotating the dehydrating tub, and an electric power supplied to the motor. An AC power supply to be supplied, a switching element interposed between the AC power supply and the motor and capable of controlling a conductive phase angle, rotation speed detection means for detecting the rotation speed of the motor, and the rotation speed detection A comparing means for comparing the rotation speed detected by the means with a predetermined reference rotation speed; and a conduction phase angle of the switching element so as to make the rotation speed of the motor closer to the reference rotation speed based on a comparison result of the comparison means. And a means for monitoring the conduction phase angle and stopping the power supply to the motor based on the conduction phase angle being maintained in a predetermined stable state. Is shall.

[0006]

According to the above arrangement, the rotational speed of the motor is detected by the rotational speed detecting means, and the detected rotational speed is compared with the predetermined reference rotational speed by the comparing means. Then, based on the comparison result, the conduction phase angle to the switching element is controlled by the phase control means. In the last stage of dehydration, the torque to be given to the motor to maintain the constant speed rotation of the dehydration tank becomes constant. Since the motor torque and the conduction phase angle have a one-to-one correspondence, if the conduction phase angle is stable, it is the end of dehydration. Therefore, the conduction phase angle is monitored, and when the conduction phase angle is maintained in a predetermined stable state, the power supply to the motor is stopped based on this, and the dehydration is terminated.

As described above, the end of dehydration is automatically determined based on the fact that the conduction phase angle has reached a predetermined stable state. Can be eliminated. That is, it is possible to perform appropriate dehydration according to the type of the object to be dehydrated.

[0008]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. FIG. 3 is a simplified cross-sectional view showing a schematic configuration of a fully automatic washing machine to which the dewatering device of one embodiment of the present invention is applied. This washing machine has an outer tub 3 elastically suspended and supported in a washing machine main body 1 via a hanging rod (not shown).
And an inner tank 5 rotatably mounted on the outer tank 3 via a rotary shaft 4. This inner tank 5 corresponds to a dehydration tank. The laundry is stored in the inner tub 5, and the outer tub 3 stores washing water.

The washing machine main body 1 is formed in a box shape having an opening on the upper surface. An operation unit 6 is provided at the front of the upper surface. In addition, a drain port 7 is formed at the bottom of the outer tank 3. The outlet 7 is connected to a drain 9 via a drain valve 8, and the drain 9 is connected to a drain hose 10 extending outside the main body 1 of the washing machine. The drain valve 8 is driven by a torque motor 11.

An air trap 1 is provided near the bottom of the outer tank 3.
2 are provided. The air trap 12 is connected to a water level sensor 13 via a pressure hose 14. The water level sensor 13 detects a change in the water level in the outer tub 3 as a change in the air pressure in the pressure hose 14. A number of fine dewatering holes 15 are formed in the inner tub 5, and a rotating blade 16 for stirring the washing water and the laundry is supported in the inner tub 5 so as to be rotatable forward and backward.

A mechanism 18 for transmitting the driving force from the motor 17 to the rotary wings 16 and the inner tub 5 is provided at the bottom of the main body 1 of the washing machine. The rotational force from the mechanism section 18 is transmitted to the inner tank 5 via the rotary shaft 4, and is further transmitted to the rotary wings 16 by an internal shaft (not shown) provided inside the rotary shaft 4. The driving force of the motor 17 is transmitted to the mechanism section 18 from the small pulley 20 via the V-belt 21 and the large pulley 22, and a rotating force is applied to the inner shaft during the washing step and the rinsing step so that the rotating blade 16 is rotated. Rotate, and during the dehydration step, a rotational force is applied to the rotating shaft 4 to rotate the inner tank 5. A magnet 23 is fixed to the small pulley 20, and a reed switch 24 serving as a rotation speed detecting means is mounted near a lower side of the magnet 23 by a switch mounting bracket 25.

FIG. 4 is a block diagram showing the electrical configuration of the washing machine. The microcomputer 50 for controlling the operation of each part of the fully automatic washing machine includes an input key circuit 60, a door switch 61 for detecting opening and closing of a door, a water level sensor 13, and a microcomputer 50 for turning on the power.
Is connected to a reset circuit 63 which supplies a reset signal. Furthermore, a thermistor circuit 64 for processing an output signal of a thermistor (not shown), a clock oscillation circuit 65 for supplying an operation clock to the microcomputer 50, and a rotation speed detection circuit 66 for processing a signal from the reed switch 24 are connected.

The microcomputer 50 performs a predetermined operation based on signals from the input key circuit 60, the door switch 61, the water level sensor 13, the reset circuit 63, the thermistor circuit 64, the clock oscillation circuit 65, the rotation speed detection circuit 66, and the like. A control signal is given to the load drive circuit 67 in accordance with the above program. As a result, after a lapse of a predetermined time after the end of the operation, the AC solenoid 68 for turning off the power, the motor 17, the water supply valve 69, and the drain valve 8 for turning off the power are controlled.
The lighting circuit 70 and a buzzer circuit 71 for notifying the end of the operation and the like are controlled.

The microcomputer 50 includes a timer 72 for counting the operation time, a rotation speed memory 73 for storing the rotation speed of the motor 17, and a conduction angle memory 74 described later. In this embodiment, the microcomputer 50 functions as a comparison unit, a phase control unit, and the like. FIG. 5 is a block diagram illustrating a configuration related to control of the motor 17.

An AC voltage from a commercial AC power supply 80 is supplied to the motor 17 via a triac 81 as a switching element. As shown in FIG. 3, a magnet 23 is fixed to the small pulley 20 for transmitting the driving force of the motor 17, and a reed switch 24 is disposed near the magnet 23. I have.

The output of the reed switch 24 is controlled by controlling the conduction phase angle of the triac 81 so that the motor 1
7 is supplied to a microcomputer 50 that adjusts the power supplied to the microcomputer 7. This microcomputer 50 also has
A detection signal is provided from a zero cross detection circuit 82 for detecting a zero cross point of the output voltage of the AC power supply 80. The microcomputer 50 derives a signal for conducting the triac 81 at a timing corresponding to the conduction angle after receiving the zero-cross point detection signal.

With this configuration, the microcomputer 5
When the conduction angle of the triac 81 is changed by 0,
The power supplied to the motor 17 can be changed, and thereby the rotation speed of the motor 17 can be changed.
Therefore, in the microcomputer 50, a reference rotation speed is set in advance, and the reference rotation speed is compared with the actual rotation speed of the motor 17 obtained from the reed switch 24.
By controlling the conduction angle of 1, the motor 17 can be rotated at a constant speed at the reference rotation speed.

The operation of the washing machine will be described with reference to the flowcharts of FIGS. First, when the dehydration process is started, it is determined whether or not the rotation speed of the motor detected by the reed switch 24 in step S1 is equal to or higher than 850 rpm, which is the reference rotation speed in the present embodiment. As a result, when it is determined that the rotational speed is 850 rpm or more, the process proceeds to step S7, and when it is determined that the rotational speed is less than 850 rpm, the process proceeds to step S2. Initially, motor 2
Since no power is supplied to 1, the number of revolutions is zero,
Move to step S2.

In step S2, it is determined whether or not the control start flag has been set. The control start flag is a flag indicating whether or not the phase control has been started. The flag is reset before the start of the phase control, and is set after the start of the phase control. When the control start flag is set, the process proceeds to step S21. When the control start flag is not set, the process proceeds to step S3. Initially, the control start flag is reset, and the process proceeds to step S3.

In step S3, the conduction angle of the triac 81 is set to 0 °. That is, initially, the motor 1
Since a large torque is required to increase the rotation speed of the motor 7 to the reference rotation speed, the conduction angle is set to 0 °, and large power is supplied to the motor 17. Thereby, the dewatering tank 5 is accelerated with the maximum torque. Next, in step S4, the detected rotation speed is sequentially stored in the rotation speed memory 73. Initially, since no voltage is applied to the motor 17, the stored number of revolutions is zero.

The processing shifts to step S5 in FIG. 2, in which the triac 81 is controlled at the conduction angle set by the microcomputer 50, a voltage synchronized with the conduction angle is applied to the motor 17, and the motor 17 is driven to rotate. Is done. In step S6, the control start flag is set, and if set, the process proceeds to step S11, and if not, the process returns to step S1. At the beginning when the rotation of the motor 17 is started, the control start flag is in a reset state, so that the process returns to step S1.

When the number of rotations of the motor 17 reaches 850 rpm, the process proceeds from step S1 to step S7. In step S7, it is determined whether or not the control start flag has been set. As a result, if the control start flag has been set, the process proceeds to step S14, and if the control start flag has not been set, the process proceeds to step S8. When the rotation speed reaches 850 rpm, step S7
When the processing in step (1) is performed for the first time, the control start flag is not set, and the process proceeds to step S8.

In step S8, a control start flag is set, and phase control is started. In starting the phase control, first, in step S9, the conduction angle is set to 132 °, and in step S10, the conduction angle 0 ° is stored in the conduction angle memory 74. The process of step S10 is a process for surely resetting the timer 72 described later.

Next, in step S4, the detected rotation speed is stored in the rotation speed memory 73. At this time, the previously stored rotation speed is deleted. That is, only the newly detected rotation speed is stored in the rotation speed memory 73. Then, in step S5, the microcomputer 5
A value of 0 controls the triac 81 at the conduction angle of 132 ° set in step S9. In step S6, it is determined whether or not the control start flag has been set. In this case, since the control start flag has been set, the process proceeds to step S11.

In step S11, it is determined whether or not one second has elapsed since the counting operation of the timer 72 in step S12 or the start of the dehydration step. As a result, if one second has elapsed, the process proceeds to step S12, and if not, the process returns to step S1.
In step S12, the count value of the timer 72 is incremented, and in step S13, it is determined whether the count value of the timer 72 is 60 or more. If the counted value is 60 or more, the process proceeds to step S24, where the motor 17
Stop supplying power to At the initial stage, since the timer 72 has been reset, steps S11, S12, S1
After step 3, the process returns to step S1.

The above is the operation from the start of the dehydration step until the rotation speed reaches the reference rotation speed and the first phase control is performed. Next, an operation after the end of the first phase control will be described. The operation is an operation for bringing the rotation speed closer to the reference rotation speed, and when the rotation speed is higher than the reference rotation speed and further increasing, the rotation speed is reduced and the rotation speed is reduced to be smaller than the reference rotation speed. If the number of rotations is decreasing, the number of rotations is increased.

First, the phase control in the case where the number of rotations is 850 rpm or more will be described. The process shifts from step S1 to step S14 via step S7. In step S14, it is determined whether or not the rotation speed is equal to 850 rpm. As a result, if the rotation speed is 850 rpm, the process proceeds to step S18, and if it is greater than 850 rpm, the process proceeds to step S15.

In step S15, the rotational speed stored in the rotational speed memory 73 is compared with a recently detected rotational speed (hereinafter, referred to as "current rotational speed"). That is, in step S15, it is determined whether the rotation speed is increasing. That is, when the current rotation speed is higher, the rotation speed tends to increase, and when the rotation speed is lower, the rotation speed tends to decrease. When the rotation speed is increasing, step S16 is performed.
The process proceeds to step S4 when there is a decreasing tendency.

In step S16, it is determined whether the conduction angle of triac 81 is 140 °. If the result of this determination is 140 °, processing transfers to step S4 and 14
If it is not 0 °, the process moves to step S17. Step S
At 17, the conduction angle detected at step S16 is 1
° Set to be increased. As the conduction angle increases, the power supplied to the motor 17 decreases. Conversely, when it is decreased, the power supplied to the motor 17 increases. As the supply power increases or decreases, the torque of the motor 17 increases or decreases. As a result, the rotation speed of the motor 17 also increases or decreases.

That is, by the processing in step S17, when the rotational speed is 850 rpm or more and is increasing, the conduction angle is increased by 1 ° in order to decrease the rotational speed. In step S18, the conduction angle stored in the conduction angle memory 74 and a recently set conduction angle (hereinafter, referred to as a conduction angle).
It is called “current conduction angle”. ) Is compared. As a result, if the current conduction angle is larger, the process proceeds to step S19, and if smaller, the process proceeds to step S4.

In step S19, the current conduction angle is stored in the conduction angle memory 74. Then, the timer 72 is reset in step S20, and the process proceeds to step S4. The processing of steps S18 to S20 is processing for resetting the timer 72 when the rotational speed is increasing. In step S14, the rotation speed is exactly 850r
pm, the process proceeds to step S18. However, since steps S15 to S17 have not been performed, the conduction angle memory 74
Is the same as the current conduction angle, and the process proceeds from step S18 to step S4. Since the contents of the conduction angle memory 74 are updated when the conduction angle is increasing, the conduction angle memory 74 eventually stores the maximum conduction angle.

Next, phase control when the number of rotations is less than 850 rpm will be described. The number of rotations is 8 in step S1
If it is determined that the rotation speed is less than 50 rpm, the process proceeds to step S21 via step S2. In step S21,
The current rotation speed is compared with the rotation speed stored in the rotation speed memory 73 to determine whether the rotation speed is decreasing. As a result, when it is determined that there is a decreasing trend, the process proceeds to step S22, and when it is determined that there is an increasing trend, the process proceeds to step S4.

In step S22, the current conduction angle of the triac 81 is checked, and it is determined whether or not the conduction angle is 10 °. If the result of this determination is 10 °, the flow proceeds to step S4; if not, the flow proceeds to step S23.
Move to In step S23, the conduction angle is reduced by 1 °. Thereby, the number of rotations is increased.

FIGS. 6 and 7 show waveforms when the above phase control is performed. FIG. 6 shows a current waveform 91 applied to the motor 17 immediately after the start of dehydration, and FIG. 7 shows a current waveform 92 applied to the motor 17 when dehydration proceeds. 6 and 7, a voltage waveform 90 from the commercial AC power supply 80 is also shown. In FIG. 6, since the dehydration has just started, a large torque is required to operate the motor 17, so that the conduction angle α is small. In addition, the load on the motor 17 changes dramatically as the water in the laundry is removed, so that a large right and left swing occurs around the conduction angle α in order to realize a constant speed control corresponding to this.

On the other hand, in FIG. 7, as the dehydration proceeds, the moisture contained in the laundry is removed and the weight is reduced. That is, the large torque that was necessary immediately after the start of dehydration is no longer necessary. Further, when the moisture in the laundry is substantially removed, the torque load of the motor 17 is stabilized.
Therefore, when the conduction angle α reaches a certain maximum value corresponding to the amount of laundry in the inner tub 5, the state shifts to a stable state thereafter. Therefore, at the end of dehydration, the conduction angle α is stabilized at a relatively large value, and there is almost no runout relative to the center.

Therefore, conversely, when the conduction angle α becomes maximum and a certain time has passed, it is understood that the end of dehydration is reached. Therefore, in the above flowchart, while the maximum conduction angle stored in the conduction angle memory 74 is being updated, the timer 7
When the maximum conduction angle is no longer updated while resetting 2 and performing phase control, the power supply to the motor 17 is stopped after 60 seconds have elapsed by the processing of steps S11 to S13 and S14.

As described above, in this embodiment, when a stable state in which the maximum value of the conduction angle is not updated for 60 seconds is detected, it is determined that the end of dehydration, and the dehydration is terminated. For this reason, since the dehydration can be terminated according to the dehydration state of the clothing, there is no excess or shortage of the dehydration regardless of the type and amount of the clothing. That is, dehydration can be appropriately performed according to the type of clothing and the like.

Further, since the phase is controlled so as to stabilize the rotation speed at 850 rpm, the fluctuation of the rotation speed is suppressed. Therefore, it is possible to reduce a change in noise generated due to a change in the number of revolutions. The present invention is not limited to the above embodiment. For example, in the above embodiment, the dehydration is terminated when the state where the maximum conduction angle is not updated continues for 60 seconds, but this time may be increased or decreased according to a desired dehydration state. Also, the reference rotation speed is 85
It is not limited to 0 rpm.

In the above embodiment, a triac is used as a switching element. However, another switching element such as a thyristor, whose conduction angle can be controlled, may be used.
Further, in this embodiment, the reed switch is used for detecting the number of revolutions, but an electromagnetic sensor or an optical sensor may be used. Further, in the above-described embodiment, the case where the present invention is applied to a fully automatic washing machine has been described. However, the dehydrating apparatus of the present invention can be easily applied to a so-called two-tub washing machine. Needless to say, the configuration may be adopted.

Various other design changes can be made without changing the gist of the present invention.

[0041]

As described above, according to the dehydrator of the present invention, when the conduction phase angle of the switching element is maintained in a predetermined stable state, the power supply to the motor is stopped based on this, and the dehydration is completed. I do. For this reason, there is no possibility that wrinkles are generated on the object to be dehydrated due to excessive dehydration, and there is no insufficient dehydration. Therefore, it is possible to perform appropriate dehydration corresponding to not only the amount but also the type of the material to be dehydrated.

[Brief description of the drawings]

FIG. 1 is a flowchart illustrating an operation of a washing machine using a dehydrator according to an embodiment of the present invention.

FIG. 2 is a flowchart continued from FIG. 1;

FIG. 3 is a cross-sectional view showing a simplified schematic configuration of the entire washing machine.

FIG. 4 is a block diagram showing an electrical configuration of the washing machine.

FIG. 5 is a block diagram showing a configuration related to motor rotation control.

FIG. 6 is a diagram showing a current waveform at the beginning of dehydration start.

FIG. 7 is a diagram showing a current waveform when dehydration proceeds.

[Explanation of symbols]

 5 Inner tank 17 Motor 24 Reed switch 50 Microcomputer 80 Commercial AC power supply 81 Triac

Claims (1)

(57) [Claims] 1. A dewatering tub for accommodating an object to be dehydrated, a motor for rotating the dewatering tub, an AC power supply for supplying electric power to the motor, and an AC power supply interposed between the AC power supply and the motor; A switching element that can control a conductive phase angle; a rotation speed detection unit that detects a rotation speed of the motor; and a comparison unit that compares the rotation speed detected by the rotation speed detection unit with a predetermined reference rotation speed. A phase control means for controlling a conduction phase angle of the switching element so as to make the rotation speed of the motor closer to the reference rotation speed based on a comparison result of the comparison means; and Means for stopping power supply to the motor based on the fact that the corner is maintained in a predetermined stable state.