JPH0150439B2 - - 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, the spin-drying operation was controlled by a spin-dry timer, but since this spin-dry timer was set based on the user's intuition and experience, there was a risk of over- or under-spinning, or damage to the cloth due to over-spinning. There was a problem. Furthermore, with such conventional methods, it has not been possible to perform so-called weak dehydration, in which only the dripping water from the laundry is gently squeezed out.

(Purpose) The present invention has been made in view of the above points, and it electrically detects the collision of water droplets of dehydration liquid squeezed from cloth subjected to dehydration with a dehydration sensor, and detects the impact based on the result. , generates a signal indicating completion of dehydration,
By automatically stopping dehydration, the conventional problems are solved and it is possible to perform weak dehydration.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 1 shows the main part of a dehydration sensor that generates an electric signal by the collision of water droplets, and includes a ceramic piezoelectric element 12 (hereinafter referred to as a piezoelectric element). Electrodes are formed on both sides of the piezoelectric element 12, respectively. ), the metal diaphragm 11 which is electrically connected to one electrode surface of the piezoelectric element 12 and bonded together, and the electrode terminals 13 and 14.

FIG. 2 is a side view of FIG. 1.

FIG. 3 shows the appearance of the dehydration sensor 10, and 15 is an electrically insulating case. 17a-d
is a stop hole.

FIG. 4 is a sectional view taken along line A-A' in FIG. 3, showing a state in which the piezoelectric element 12 and metal diaphragm 11 shown in FIG. It shows. 15a is case 15
It is a circular protrusion provided on the.

FIG. 5 is a cross-sectional view of the main parts when the dehydration sensor 10 is attached to the dehydrator, in which 1 is the machine frame, and the machine frame 1 is connected to the machine frame 1 via a cushioning material (for example, a spring) 4 to drive the dehydration tank 5. Motor 2 is installed. Dehydration tank 5
is connected to motor 2 by shaft 3. Reference numeral 6 is located on the outer periphery of the dehydration tank 5 and is a water receiving tank for receiving the dehydration 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 8g through which the dehydration liquid passes. And the dehydration sensor 10 is connected to the dehydration tank 5
Hole 8a, or 8b, or 8 drilled at the bottom of
c, or 8d, etc.

FIG. 6 is an enlarged cross-sectional view of a main part showing a state in which the dehydration sensor 10 is attached. The case 15 of the dehydration sensor 10 covers the hole made in the dehydration tank 6, and the screw 19 and nut 2 are inserted through the gasket 18a.
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. 7 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; 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 (one output is for a short time) via the circuit 23, there is a peak value hold circuit 24 that generates an output that is discharged in a longer time than that, and when the output exceeds a certain voltage, it outputs an L signal. , and a comparator circuit 25 which outputs an H signal when the output falls below a certain voltage.

In Fig. 7, 26 is a strong switch that starts a strong spin process (normal spin process), and 28 is a weak switch that starts a strong spin process (weak spin process). Depending on the type of laundry, squeezing out the water may cause inconveniences such as wrinkles on the laundry or damage to the fabric. ).
A weak switch 100 for starting the controller 100 is a controller composed of a microcomputer, and the basic configuration of the controller 100 and its relationship with external circuits are 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.
It is a drive circuit that turns on and off, and in Figure 7, a relay is assumed to be in the drive circuit, and its contact point is 33. 3
0, 32 are windings of the motor 2, and 31 is a capacitor.

FIG. 9a shows a model of the output waveform from the amplifier circuit 22, and here shows the state when 1 kg of dehydrated cloth shown in FIG. 10 is dehydrated. Further, FIG. 9b shows an output model of the comparator circuit 25 corresponding to FIG. 9a. Figure 9a
When the dehydration starts (0 seconds), the water droplets of the dehydration liquid collide with the dehydration sensor 10, so a large output is generated at short intervals for about 7 seconds (this time varies depending on the type and amount of cloth, etc.). It is obtained one after another, but about 15
After seconds (this time also varies depending on the type and amount of cloth), the amount of water removed rapidly decreases, and the number of water droplets colliding with the dehydration sensor 10 decreases and becomes smaller, resulting in a smaller output. Become. Applying this point to Figure 10, approximately 7 seconds is approximately the dehydration rate.
This corresponds to 40%. (Experiments based on the definition of mild dehydration show that this dehydration rate is approximately 40%). Therefore, by stopping the motor in about 7 seconds, weak dehydration will be performed. On the other hand, at the point of about 15 seconds, as mentioned above, the dehydration rate changes from rapid to slow, and in order to actually squeeze it out (strong dehydration), several times this time (for example, 3 times) is required. This is what is required from experiments.

As is clear from the above explanation, during weak dehydration, the motor 2 is stopped when the output of the comparison circuit 25, that is, the output of the detection section 21 changes from H to L, and during strong dehydration, the output of the detection section 21 changes from the start of dehydration to H. From L
The time is set based on the time required for the cloth to change, and the motor 2 is stopped as the time elapses, and the time at each point differs depending on the type and amount of cloth.

Note that the dehydration rate is determined by the following formula. however,
The amount of cloth is the amount of air-dried cloth.

Dehydration rate (%)=100-{(amount of water-containing cloth)-(amount of cloth)/(amount of cloth)×100} Next, control of the dehydration operation will be explained according to the flowchart of FIG. 11.

When you want to perform strong dehydration, first turn on the strong switch 26.
Turn on. When the ON of the strong switch 26 is confirmed by the L input of _I1 , the output of _O1 becomes H, and the drive circuit 27
The motor 2 is driven via the timer 10.
Start 4. Timer data T is T≧
At 40 seconds (meaning that the signal is not seen for 40 seconds), the input from the detection unit 21 (input signal is H or L)
Determine whether I ₂ = L, and if I ₂ is not L, then
Check for 60 seconds, and if it is not L for more than 60 seconds, it will be determined that there is some kind of abnormality, and motor 2 will be stopped.
Stop the timer 104 and clear the timer data. On the other hand, if I ₂ =L before 60 seconds,
Next, wait until I ₂ =H, and when I ₂ =H, read the timer data T and set T = T ₁ . A strong dehydration completion time T ₂ (T ₂ =T ₁ ×3) is calculated from this T ₁ and it is determined whether this T ₂ is T ₂ ≧5 minutes.
If T ₂ < 5 minutes, it is determined whether the timer data T is T≧T ₂ , and when T≧T ₂ is reached, it is judged that strong dehydration is complete and the output of O ₁ 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. On the other hand, if T ₂ ≧ 5 minutes, it is determined whether the timer data T is T ≧ 5 minutes, and when T ≧ 5 minutes, O ₁ is set regardless of T _2.
Set the output to L to forcefully stop strong dehydration.

In such a strong dehydration operation, the dehydration operation can be executed for a minimum of 60 seconds regardless of the input signal from the detection unit 21.
In the event that the dehydration sensor 10 falls into a state of poor sensitivity due to adhesion of foreign matter, dehydration is performed for 60 seconds to dehydrate the object to be dehydrated to the extent that no droplets fall, that is, to the minimum dehydration rate. It's for a reason. For JIS cloth (cotton) 3.3Kg,
As shown in FIG. 12, which shows the relationship between dehydration time and dehydration rate, dehydration for 60 seconds results in a dehydration rate of about 50%.

On the other hand, the reason why the dehydration operation is forcibly stopped after a maximum of 5 minutes regardless of the control content based on the input signal from the detection unit 21 is as shown in Fig. This is because the dehydration rate hardly changes even when the time is exceeded, and fabric staining is more likely to occur.By setting the maximum time, wasteful operation and fabric staining are prevented.

Next time you want to perform a weak dehydration, first turn on the weak switch 28.
Turn on. When the low input of _I3 confirms that the weak switch 28 is ON, the output of _O1 becomes H, and the drive circuit 27
The motor 2 is driven via the timer 104.
Start. Timer data T is T≧7
When the second comes (meaning you don't see the signal for 7 seconds),
The input from the detection unit 21 (input signal is H or L) is I ₂
=L, and if I ₂ =L, the weak dehydration has been completed, so the output of _O1 is set to L, and the drive circuit 2
Stop the motor 2 via 7 and start the timer 10.
Stop 4 and clear the timer data.
If I ₂ does not become L for 30 seconds or more, it is determined that some abnormality has occurred as described above, and the motor 2 is stopped, the timer 104 is stopped, and the timer data is cleared.

The reason why the longest dehydration time was set in such a weak dehydration operation was to be able to respond when the dehydration sensor 10 became sensitive, and in particular, the reason why it was set to 30 seconds in this embodiment was as follows. This is because the amount of wrinkles increases rapidly after 30 seconds, as shown in Figure 13, in the case of 6 sheets of white paper (1 kg, unbleached type), and the purpose is to suppress the occurrence of such wrinkles. It is said that The amount of wrinkles is measured by reading the number of wrinkles in the same area after taking a photograph.

The reason why there is a difference in the maximum and shortest dehydration times between strong dehydration and weak dehydration is that the type and amount of cloth used for dehydration generally differs, and the load tends to be lighter in mild dehydration. .

In the above embodiment, the collision of the water droplets of the dehydration liquid squeezed from the cloth to be dehydrated with the dehydration sensor 10 is electrically detected, and a signal indicating the completion of dehydration is generated based on the result. By automatically stopping the dehydration operation, strong dehydration can be performed without causing problems such as excess or dehydration or fabric stains due to excessive dehydration. The dehydration sensor 10 detects the first point in time when it generates an electric signal due to liquid collision, that is, the point in time when the output of the comparator circuit 25 changes from H to L, and stops the dehydration operation, thereby performing dehydration with a dehydration rate of about 40%. This reduces problems such as fabric damage and wrinkles when dehydrating light-load, delicate clothing (synthetic fibers, wool, etc.).

Next, control at the time of operation switching will be explained. now,
When the weak switch 28 is turned on during strong dehydration, as shown in the flowchart of FIG. 14, it is first determined whether the data T of the timer 104 is T>30 seconds, and if The dehydration operation is stopped, and if T>30 seconds, it is next determined whether I ₂ =L, and if I ₂ =L, the dehydration operation is stopped.
On the other hand, if I ₂ =L, weak dehydration is performed by continuing the dehydration operation until T>30 seconds or until I ₂ =L.

Strong switch 26 is ON during weak dehydration.
Then, as shown in the flowchart in Figure 15,
Timer 10 when strong switch 26 is ON
4 data T and input from the detection unit 21 (H or L)
is loaded, and while these contents are continued, the process shifts to strong dehydration, and thereafter is controlled in the same manner as the strong dehydration operation described above.

Note that the maximum dehydration time and the shortest dehydration time are not limited to the times in the above embodiments, and may of course be set as appropriate depending on the rated capacity, rotation speed, etc. of the dehydrator.

(Effects) As described above, the present invention can not only dehydrate the laundry without causing problems such as excessive dehydration or dehydration or staining of the cloth due to excessive dehydration, but also removes only the water that drips out of the moisture in the laundry. Weak dehydration by gently squeezing can also be carried out, and by setting the maximum dehydration time for strong dehydration and weak dehydration individually, problems such as cloth damage and wrinkles are eliminated, which is convenient in practice.

[Brief explanation of drawings]

The figures show an embodiment of the present invention, and FIGS. 1 and 2 are front and side views showing the main parts of the dehydration sensor, FIG. 3 is a front view of the dehydration sensor, and FIG. A-A' sectional view in the figure, Figure 5 is a schematic cross-sectional configuration diagram of the dehydrator equipped with a dehydration sensor, and Figure 6
The figure is a sectional view showing how the dehydration sensor is installed.
The figure is a block diagram of the main parts of the electronic control circuit, Figure 8 is a diagram showing the relationship between the controller and external circuits, Figure 9 a and b are output waveform diagrams of each part, and Figure 10 is a diagram showing temporal changes in dehydration rate. Figure 11 is a dehydration control flowchart, Figure 12 is a diagram showing temporal changes in dehydration rate, Figure 13 is a diagram showing temporal changes in wrinkle generation amount, and Figure 14 is a flowchart for switching from strong to weak. , 1st
Figure 5 is a flowchart for switching from weak to strong. 10: Dehydration sensor, 21: Detection unit, 26: Strong switch, 28: Weak switch, 100: Controller.

Claims (1)

[Claims] 1. A dehydration sensor that generates an electrical signal when the dehydration liquid collides, a strength setting means for setting the strength of dehydration, and a dehydration operation that automatically controls the dehydration operation based on the electric signal from the dehydration sensor in accordance with the strength setting by the setting means. The control means individually sets the maximum dewatering time in order to forcibly stop the dewatering operation at a certain time from the start of dehydration regardless of the control content based on the electric signal from the dehydration sensor during strong dehydration and weak dehydration. A dehydration control device comprising: