JPH0251357B2 - - Google Patents

Description

Detailed Description of the Invention (Technical Field) The present invention relates to a dehydration control device for a fully automatic washing machine, centrifugal dehydrator, etc.

(Prior art) Conventionally, a dehydration tank includes a detection unit that outputs a predetermined signal when the amount of water discharged from the dehydration tank reaches a predetermined amount.
In the dehydration control device that controls the dehydration operation based on the output signal of this detection unit, a certain signal dead time (set in consideration of unstable time due to vibrations etc. when the motor starts driving) is set after the start of dehydration. When the time period has elapsed, it is determined whether the output signal of the detection unit is a predetermined signal or not. When it is determined that the output signal is a predetermined signal, the next point in time when the predetermined signal stops is detected, and dehydration is started at this point. The elapsed time from the start is read, and the end of the dehydration operation is controlled based on this time.

However, with such conventional dehydration control devices, if the dehydrated material is unbalanced in the dehydration tank, the dehydration operation is unstable even after a certain signal dead time has elapsed, and the output of the detection unit obtained is The signal was also unstable, leading to incorrect judgments and problems such as insufficient dehydration.

On the other hand, if the unbalance of the dehydrated product is taken into account and the signal dead time is increased, and the determination is made when the output signal of the detection section becomes stable, the above problems can be resolved. On the other hand, if the amount of dehydrated material is small, there is a risk that a predetermined signal from the detection section may be interrupted during the signal dead time, making it impossible to accurately perform dehydration control.

(Objective) The present invention has been made in view of the above points, and is intended to enable accurate dehydration control regardless of unbalance of dehydrated product, small amount of dehydration, etc.

(Example) First, the configuration of the present invention will be explained with reference to FIG. a first signal determining means for determining whether or not the signal is a predetermined signal; and a second signal determining means for repeatedly determining whether or not the predetermined signal continues for a certain period of time when the first signal determining means determines that the signal is a predetermined signal. a timer means for counting the time from the start of dehydration; and a second signal determination means, when it is determined by the second signal determination means that a predetermined signal has continued for a certain period of time, the timer means receives time data from the start of dehydration. A storage means that reads and stores the stored time data and updates the stored time data every time it is determined that a predetermined signal has continued for a certain period of time, and a dehydration operation based on the time data of the storage means when a predetermined time has elapsed from the start of dehydration. and a control means for controlling the end of the dewatering operation, and automatically controls the dewatering operation.

Hereinafter, one embodiment of the present invention will be described in detail.

Figure 2 is a front view showing the main parts of the dehydration sensor;
FIG. 3 shows the same side view, showing a ceramic piezoelectric element 12 (hereinafter referred to as a piezoelectric element. Electrodes are formed on both sides of the piezoelectric element 12, respectively) and the piezoelectric element 1.
2 shows the external appearance of the metal diaphragm 11 and the electrode terminals 13 and 14, which are connected to one electrode surface of the metal diaphragm 11 and bonded together.

FIG. 4 shows the appearance of the dehydration sensor 10, and 15 is an electrically insulating case. 17a~
d is a stop hole.

FIG. 5 is a sectional view taken along line A-A' in FIG. 4, in which the piezoelectric element 12 and metal diaphragm 11 shown in FIG. 2 are fixed so as to be vibrating by electrically insulating cases 16 and 15. Indicates the condition. 15a is a circular protrusion provided on the case.

FIG. 6 is a cross-sectional view of the main parts when the dehydration sensor 10 is installed in a dehydrator. 1 is a machine frame, and the machine frame 1 has a motor 2 that drives the dehydrator tank 5 via a cushioning material (for example, a spring) 4. is installed. The dewatering tank 5 is connected to the motor 2 by a shaft 3. Reference numeral 6 is a water receiving tank located on the outer periphery of the dewatering tank 5 for receiving the dehydrated liquid, and a drain pipe 7 is connected to a part of the bottom of the tank. The dehydration tank 5 has an appropriate number of holes 8a to 8d through which the dehydration liquid passes. Several dehydration sensors 10 (9 in this embodiment) are provided at the bottom of the dehydration tank 5.
The hole 8a is provided so as to face the hole 8a of the hole 8a.

FIG. 7 is an enlarged sectional view of a main part showing the state in which the dehydration sensor 10 is attached. The case 15 of the dehydration sensor 10 is inserted into the screw 19 and the nut 2 through the gasket 18a in such a way as to cover the hole made in the water tank 6.
0, it is closely fixed to the water receiving tank 6. The protrusion 15a of the case 15 bites into the gasket 18a. 18b is also Patsukin. The arrows indicate where the water droplets collide.

FIG. 8 is a block diagram of the main part of the electronic control circuit that controls the dehydration process, in which the detection section 21 is connected to the dehydration sensor 10.
an amplifier circuit 22 for amplifying the output voltage of the dehydration sensor 10; and a comparison circuit 23 provided to compare the output voltage with a constant voltage and output only when the voltage is higher than the constant voltage in order to eliminate a small output voltage from the dehydration sensor 10. When there is an output via the comparator circuit 23 (one output is for a short time), a peak value hold circuit 24 generates an output that is discharged in a longer time than that, and when the output exceeds a certain voltage, an L signal is generated. The comparator circuit 25 outputs an H signal when the output voltage falls below a certain voltage.

In FIG. 8, 26 is a start switch that starts the dehydration process, 100 is a controller composed of a microcomputer, and controller 10
The relationship between the basic configuration of 0 and the external circuit is shown in FIG.

101 is a CPU, 102 is a program/fixed data memory ROM, and 103 is a temporary storage memory.
RAM, 104 is a timer, and 105 is an I/O section (input/output section). 27 controls the motor 2 by the output of the controller 100.
This is a drive circuit that turns on and off, and in Fig. 8, a relay is assumed to be used in the drive circuit, and its contact point is 33.
30 and 32 are windings of the motor 2, and 31 is a capacitor.

Next, an example of controlling the dewatering operation will be explained according to the flowchart of FIG. 10. First, turn on the start switch 26. When the start switch 26 is confirmed to be ON with the L input of _I1 , the initial setting A =
Do 0. Next, the output of _O1 is set to H, the motor 2 is driven via the drive circuit 27, and then the timer 104 is started. Timer data T
becomes T≧5 seconds (because the input signal from the detection unit 21 is unstable when the motor 2 starts up,
2 seconds) and the input from the detection unit 21 (input signal is H or L) determines whether I ₂ = L. If I ₂ = L, then I ₂ = L. Determine whether a certain period of time t (for example, 1 second) continues,
When it is determined that it is continuous for t time, flag A is set to 1,
The timer data T at this point is read and stored as data _T1 . Therefore, such I ₂
= L, t The determination of time continuity is repeated until the timer data T reaches, for example, 60 seconds, and each time I ₂ =L, t time continuity is determined, the timer data T at that time is read and data T ₁ is rewritten as needed. go. or,
If I ₂ =L is not reached when T≧5 seconds, continue as above until timer data T reaches 60 seconds.
I ₂ = L, repeat the determination of t time continuity, I ₂ = L,
When it is determined that the continuous time is t, flag A is set to 1,
Read the timer data T and write it as data T ₁ , and write that data T ₁ as I ₂ =L, as above.
It is updated every time it is determined that it is continuous for t time.

Then, when T≧60 seconds, it is determined whether A = 1 or not. If A = 1, there is some kind of abnormality (e.g., there is no cloth, the motor is not rotating normally. etc.), the motor 2 is stopped, the timer 104 is stopped, and the timer data is cleared. On the other hand, if A=1, the timer data T ₁ is read and the dehydration completion time T ₂ (T ₂ =T ₁ +TA) is calculated from this T ₁ . Then, it is determined whether or not the timer data T is T≧T _2. If T≧T ₂ , dehydration has been completed, and O ₁
The output is set to L, the motor 2 is stopped via the drive circuit 27, the timer 104 is stopped, and the timer data is cleared. In addition, the above times T ₂ and T _A
This will be discussed later.

Here, taking as an example the case where 3 kg of ramen cloth (rated capacity) is dewatered in an unbalanced state, the change in the dewatering rate and the change in the output of the detection section 21 at this time will be explained with reference to FIG. At the beginning of dehydration, the dehydrated product is in an unbalanced state, so the motor 2 has a slow start-up and the rotational speed is low, but the dehydration rate changes rapidly because the amount of water contained in the dehydrated product is large. However, when the amount of water contained in the dehydrated product decreases to a certain extent, the rotation speed of the motor 2 has not yet reached the steady rotation speed and is in a low state, so the change in the dehydration rate becomes slow, and then as time passes, the motor 2 When the rotation speed reaches a steady state, the dehydration rate changes rapidly again. Eventually, when the dehydration rate rises to a certain level, the change in the dehydration rate becomes slow. That is, the change in dehydration rate is rapid at the beginning of dehydration, then becomes slow, then becomes rapid again, and finally becomes slow. On the other hand, the output signal of the detection unit 21 changes as shown in FIG. 11 as the dehydration rate changes, and there are two sections where the signal becomes L.

Note that the dehydration rate is determined by the following formula. However, the weight of the cloth is the weight of the naturally dried cloth.

Dehydration rate = 100 − {Weight of cloth containing water − Weight of cloth / Weight of cloth × 100
} However, in the above embodiment of the present invention, the determination that I ₂ =L, continuous for t seconds is repeated until the timer data T becomes T≧60 seconds, and each time it is determined that I ₂ =L, continuous for t seconds, The timer data T is read in, the data _T1 is updated, and when T≧60 seconds, the data _T1 is read out, and the dehydration completion time _T2 is calculated based on this _T1 . That is, the data T ₁ at the last time when I ₂ = L and continuity for t seconds were determined (point a in Figure 11)
Calculate based on. On the other hand, in the conventional method, when the L signal first stops (b in Fig. 11),
Since the dehydration completion time is calculated based on the data T ₁ of point), this obviously results in insufficient dehydration.In the embodiment of the present invention, such insufficient dehydration can be resolved, and the completion of the dehydration operation can be Can be precisely controlled.

Note that the above time T _A is a time determined in advance based on the experimental data, which was determined through experiments to find out how much additional time is required in addition to the time T ₁ to actually squeeze out the dehydrated material, and T ₁ A predetermined time T _A
By adding , the dehydration completion time T ₂ , that is, the time required to actually squeeze out the water, is calculated.

In the above example, I ₂ = L, the reason why the time to repeat the continuous determination for t seconds was set to 60 seconds is to deal with dehydration at the time of imbalance, which is the slowest point at which the change in dehydration rate finally becomes slow. This is because, as shown in Figure 11, the dehydration rate changes slowly within 60 seconds, so if you set it to 60 seconds, it will not only help with unbalanced dehydration, but also when it is not unbalanced or when a small amount of water is being dehydrated. However, it is possible to accurately determine the point at which the change in dehydration rate finally changes from rapid to slow.
It should be noted that such time (60 seconds) and furthermore, the signal dead time (5 seconds) are values that can be determined according to the rated capacity etc. during implementation, and are not particularly limited to the values in the example. .

Also, the reason for determining whether I ₂ =L continues for t seconds is that for instantaneous signals due to noise etc.
This is to prevent misjudgment.

Furthermore, in the above embodiment, a piezoelectric element is used as the dehydration sensor to detect the amount of water discharged from the dehydration tank, but for example, a detector consisting of a light emitting element and a light receiving element is provided at the drain port, The moisture content may be detected optically.

The dehydration control device of the present invention is more effective in fully automatic washing machines where the dehydration tank is large and the dehydrated product is likely to be unbalanced.

(Effects) As described above, according to the present invention, accurate automatic dehydration control can be performed regardless of unbalanced dehydration, small amount dehydration, or the like.

[Brief explanation of drawings]

FIG. 1 shows the configuration of the present invention, FIGS. 2 to 11 show embodiments of the invention, and FIGS.
The figure is a front view and side view showing the main parts of the dehydration sensor, Figure 4 is a front view of the dehydration sensor, Figure 5 is a sectional view taken along line A-A' in Figure 4, and Figure 6 is a dehydration sensor equipped with the dehydration sensor. A schematic cross-sectional configuration diagram of the machine, Figure 7 is a cross-sectional diagram showing the installed state of the dehydration sensor, Figure 8 is a block diagram of the main parts of the electronic control circuit, Figure 9 is a diagram showing the relationship between the controller and external circuits, and Figure 10 is a diagram showing the relationship between the controller and external circuits. The figure is a dehydration control flowchart, and FIG. 11 is a diagram showing changes in the dehydration rate and changes in the output signal of the detection unit during unbalanced dehydration. 5: Dehydration tank, 10: Dehydration sensor, 21: Detection section, 100: Controller.

Claims (1)

[Claims] 1. In a device that includes a detection unit that outputs a signal corresponding to the amount of water discharged from the dehydration tank and controls the dehydration operation based on the output signal of the detection unit, it is determined whether the output signal of the detection unit is a predetermined signal or not. a first signal determining means for determining whether the signal is a predetermined signal; and a second signal determining means for repeatedly determining whether or not the predetermined signal continues for a certain period of time when the first signal determining means determines that the signal is a predetermined signal. , a timer means for counting time from the start of dehydration; and a second signal determination means, when it is determined by the second signal determination means that a predetermined signal has continued for a certain period of time, reads and stores time data from the start of dehydration from the timer means, and also stores the time data from the start of dehydration. storage means for updating the time data stored in the storage means each time it is determined that a predetermined signal has continued for a certain period of time; and control for controlling the end of the dehydration operation based on the time data stored in the storage means when a predetermined time has elapsed from the start of dehydration. A dehydration control device comprising means.