JPS635120B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to a method for controlling dehydration in fully automatic washing machines, centrifugal dehydrators, and the like.

(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 out of 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 problems of the conventional method are solved and weak dehydration can be performed.

(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 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 8g through which the dehydration liquid passes. A dehydration sensor 10 is provided so as to face a hole 8a, 8b, 8c, or 8d formed in the lower part of the dehydration tank 5.

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 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. 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 Figure 7, 26 is the strong switch that starts the strong spin process (normal spin process), and 28 is the weak switch that starts the 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. 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. 8.

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. 7, a relay is assumed in the drive circuit, and its contact point is 33. 3
0 and 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 in correspondence with FIG. 9a. In Fig. 9a, water droplets of the dehydrating liquid collide with the dehydrating sensor 10 at the start of dehydration (0 seconds), resulting in a large output in about 7 seconds (this time varies depending on the type and amount of cloth, etc.). are obtained one after another at short intervals, but about
After 15 seconds (this time also varies depending on the type of cloth, amount, etc.), the amount of dehydration decreases rapidly, and the number of water droplets colliding with the dehydration sensor 10 decreases and becomes small, resulting in a small output. becomes. 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 the dehydration rate is approximately 40%.) Therefore, mild dehydration can be performed by stopping the motor in approximately 7 seconds. become. 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, 5 times) is required. This is what is required from experiments.

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≧
When the time reaches 10 seconds (meaning that the signal is not seen for 10 seconds), the input from the detection unit 21 (the input signal is H or L)
Determine whether I ₂ = L, and if I ₂ is not L, then
Check for 40 seconds, and if it is not at L for 40 seconds or more, it is determined that there is some kind of abnormality (for example, no cloth is inserted, the motor is not rotating normally, etc.), and motor 2 is turned off.
, the timer 104 is stopped, and the timer data is cleared. On the other hand, less than 40 seconds I ₂
If =L, wait until I ₂ =H, then I ₂ =
If it becomes H, read the timer data T and T=
Let it be T ₁ . From this T ₁ to the strong dehydration completion time T ₂ (T ₂ =
T ₁ ×5) is calculated. Next, the timer data T
is T≧T _2. If T≧T ₂ , strong dehydration has been completed, the output of O ₁ is set to L, motor 2 is stopped via drive circuit 27, and timer 1 is set.
Stop 04 and clear the timer data.

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≧5
When the second comes (meaning don't look at the signal for 5 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 difference in abnormality detection period between strong dehydration and weak dehydration is due to the fact that the type and amount of cloth used for dehydration is generally required, and that mild dehydration tends to result in a lighter load.

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 excessive or insufficient 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 to achieve dehydration with a dehydration rate of approximately 40%. can be done.

(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. Mild dehydration by gently squeezing can also be performed, which is convenient in practice.

[Brief explanation of the drawing]

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. 11 is a dehydration control flowchart. 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 due to collision of dehydration liquid, and a control means that automatically controls the dehydration operation based on the electrical signal from the dehydration sensor.
A strength setting means for setting the strength of dehydration is provided, and the dehydration sensor detects the first point in time when the dehydration sensor generates an electric signal due to collision of the dehydration liquid when setting the weak dehydration by the strength setting means, and controls the dehydration operation to be stopped. Dehydration control method.