JPH03198898A - Washing machine - Google Patents

Abstract

PURPOSE:To detect a waterlevel accurately, by a method wherein both an ultrasonic transmitter provided at the lower part of a water tub and an ultrasonic detector fitted at the above position perpendicular to the position of the ultrasonic transmitter at the water tub, and used, and they are composed so that the waterlevel in the water tub is detected on the basis of a propagation time when the ultrasonic wave is propagated between them. CONSTITUTION:When water is in a water tub 2, the ultrasonic wave transmitted from an ultrasonic transmitter 3 reaches an ultrasonic detector 4, in passing through the air after the ultrasonic wave passes through the water. When the water is not in the water tub 2, the ultrasonic wave passes through only the air. For that reason, in corresponding to a waterlevel in the water tub 2, the higher the water level is, the shorter a propagation time T when the ultrasonic wave is propagated between the ultrasonic transmitter element 3 and the ultrasonic detector 4. On the basis of the relation between this waterlevel and the propagation time T, the waterlevel in the water tub 2 can be detected by measurement of the propagation time T. In this way, the waterlevel in the water tub can be accurately detected.

Description

Detailed Description of the Invention [Object 1-1 of the Invention] (Industrial Application Field) The present invention relates to a one-tab (water tank) type washing machine used in general households to remove stains from clothes, etc. In particular, the present invention relates to a water level detection unit in an aquarium.

(Prior art) Washing machines that are currently widely used in households are:
Many of them have a two-tab structure, consisting of a rotating dehydration tank and a fixed water tank cover (also called a dehydration tray) that covers the area around the dehydration tank and acts as a water receptacle.

On the other hand, a washing machine with a one-tab structure has a structure in which the dehydration tank and the water tank cover are integrated, so it uses less water, the volume of the washing machine can be reduced, and it is also possible to use powdered soap that is difficult to dissolve. It has many advantages.

Comparing the two types of washing machines mentioned above, in order to extract information on the water level in the water tank, which is essential for such washing machines, in the case of the two-tab structure, the water tank cover is fixed, so there is no communication with the water tank cover. A bendable tube (rubber tube) is installed above the outer box to reduce pressure! The mainstream method is to transmit water pressure to the sensor via air.

On the other hand, washing machines with a one-tab structure do not have a water tank cover and the spin-drying tank from which water level information is extracted rotates, so the same method as with two-tab structures cannot be used. As a means of obtaining water level information in a washing machine with a one-tab structure, an ultrasonic element is installed in the outer box above the dehydration tank, and the ultrasonic waves transmitted from the outer box are reflected on the water surface and sent to the outer box. The distance between the outer box and the water surface is 1111 constant (7
A method of detecting the water level in an aquarium using this method is known.

(Problems to be Solved by the Invention) In the conventional one-tab structure washing machine described above, the means for detecting the water level in the water tank deforms the spring suspending the dehydration tank due to the water level (weight of water). The positional relationship between the outer box and the dehydration tank changes, and if there are bubbles on the water surface, the ultrasonic waves are reflected at the interface between the air and bubbles, making it difficult to accurately determine the water level in the tank. The problem was that it was difficult to detect.

Therefore, an object of the present invention is to provide a washing machine that can accurately detect the water level in a water tank.

[Structure of the Invention (Means for Solving the Problems) In order to solve the above-mentioned problems, the present invention provides a single-tank type washing machine in which a water tank serving as a washing tank and a dehydration tank is installed in an outer box. an ultrasonic transmitter installed at the bottom of the water tank to transmit ultrasonic waves vertically upward; and an ultrasonic transmitter installed above the ultrasonic transmitter in the vertical direction in the water tank to receive the ultrasonic waves from the ultrasonic transmitter. an ultrasonic receiver and a first transmitter disposed near the ultrasonic transmitter and transmitting the power and necessary signals of the ultrasonic transmitter through a space between the outer box side and the water tank; power/signal transmission means; and a second device disposed near the ultrasonic receiver T and transmitting the electric power and necessary signals of the ultrasonic receiver through a space between the outer box side and the water tank. The gist thereof is to include a power/signal transmission means and a shielding member that shields an ultrasound propagation path between the ultrasound transmitter and the ultrasound receiver from other spaces within the water tank.

(Function) The propagation speed of ultrasonic waves is about four times faster in water than in air at 1 atm O°C. The washing machine of the present invention takes advantage of this by using an ultrasonic transmitter installed at the bottom of the water tank and an ultrasonic receiver installed above the ultrasonic transmitter in the water tank in the vertical direction. Detection of the water level in the aquarium (11) is performed by measuring the time during which the ultrasonic waves pass. Therefore, even if the spring that suspends the aquarium is deformed due to the water level (weight of water) and the positional relationship between the outer box and the aquarium changes, water level detection will not be affected, and there will be no bubbles on the water surface. Even in such a case, the time it takes the ultrasonic waves to pass through the bubbles is almost the same as the time it takes them to pass through the air, so the bubbles will not be mistakenly detected as the water surface. Therefore, it becomes possible to detect the water level in the water tank with high accuracy.

(Example) Hereinafter, examples of the present invention will be explained in Figure 1 and below. This will be explained using diagram J6.

First, to explain the structure of a washing machine, in Fig. 1, 1 is an outer box, and inside the outer box 1 is a water tank that doubles as a water tank cover (washing tank) for storing clothes to be washed and water, and a water spindle. (Tab) 2
is stored. An ultrasonic transmitter 3 is installed at the bottom of the water tank 2 so as to transmit ultrasonic waves vertically upward. An ultrasonic receiver 4 is attached facing toward.

As shown in FIG. 2, the power and transmission timing signals of the ultrasonic transmitter 3 are transmitted from a control unit 5 to a power transmitter 6 and a signal transmitter 7 provided inside and below the outer box 1.
Electric power is sent to the signal transmitting section 10 via wiring, and from this power/signal transmitting section 10, as described later, is transmitted through space to a power receiving section 8 and a signal receiving section 9 provided near the ultrasound transmitter 3. - Sent to the signal receiving section 20. Next, the signal is finally transmitted from this power/signal receiving section 20 to the ultrasonic transmitter 3 via wiring. The power/signal transmitter 10 and the power/signal receiver N520 constitute a first power/signal transmission means that transmits power and necessary signals between the outer box 1 side and the water tank 2 through the space. ing.

On the other hand, the power of the ultrasonic receiver 4 is transmitted from the control unit 5 to a power transmitting/signal receiving section 30 provided inside and above the outer box 1.
The power is sent to the power transmitting unit 13 via wiring, and the power is received from the power transmitting/signal receiving unit 30 via space, as described later, at the power receiving/signal transmitting unit 40 provided near the ultrasonic receiver T-4. It is sent to Department 14. Next, the power is transmitted from the power receiving/signal transmitting section 40 to the ultrasonic receiver 4 via wiring. Ultrasonic receiver
The signal at the reception timing of No. 4 is transmitted from the signal transmitting section 15 in the power receiving/signal transmitting section 40 to the signal receiving section 16 in the power transmitting/signal receiving section 30 via space, contrary to the power transmission. It has become. The above power transmission
The signal receiving section 3o and the power receiving/signal transmitting section 40 constitute a second power/signal transmission means that transmits power and necessary signals between the outer box 1 side and the water tank 2 through the space. There is.

As described using FIG. 1, the power/signal transmitting section 10 is provided in the outer box 1, but it may be provided in the motor support section 17. That is, in this specification, the outer case side refers to the fixed part side of the washing machine including the outer case 1 and the motor support part 17. In addition, the method for installing the ultrasonic transmitter 3 to the water tank 2 is as follows.
There are two methods: the main body of the ultrasonic transmitter 3 protrudes into the water tank 2, or a member is inserted between the transmitting surface and the outer surface of the water tank 2. A shielding plate member 18 is provided in the water tank 2 so that the propagation path of the ultrasonic waves is not obstructed by clothing. This plate-like member 18 is detachably attached to the water tank 2. Reference numeral 621 is a dehydration guide that guides water to the drain valve 22 during dehydration.

23 is a motor, and 24 is a lid. Note that the drain valve 22 is controlled in the same manner as the ultrasonic transmitter 3 and the ultrasonic receiver 4.
Performed by power/signal transmission.

Since the water level detecting section in the washing machine of this embodiment is configured as described above, the ultrasonic waves transmitted from the ultrasonic transmitter 3 pass through the water when there is water in the water tank 2.
Furthermore, it passes through the air and reaches the ultrasonic receiver 4. If there is no water in the water tank 2, the ultrasonic waves will only pass through the air. The propagation speed of ultrasonic waves is about four times faster in water than in air at 1 atm O°C. Therefore, depending on the water level in the water tank 2, the higher the water level is, the shorter the propagation time T for the ultrasound to propagate between the ultrasound transmitter 3 and the ultrasound receiver 4. FIG. 3 shows the relationship between the water level in the water tank 2 and the propagation time T of the ultrasonic waves.

The propagation time T decreases linearly as the water level rises.

Therefore, by measuring the propagation time T based on the relationship between the water level and the propagation time T, the water level in the water tank 2 can be detected. When the water level is constant n1, the water level (weight of water) deforms the spring that suspends the water tank 2 and changes the positional relationship between the outer box 1 and the water tank 2, but the water level cannot be detected. Furthermore, even if there are bubbles on the water surface, the time it takes for the ultrasonic waves to pass through the bubbles is approximately the same as the time it takes to pass through the air, so there is no possibility that the bubbles will be mistakenly detected as the water surface. Therefore, the water level in the water tank 2 can be detected with high accuracy.

FIG. 4 is a circuit example of the ultrasonic transmitting circuit 11 ((a) in the same figure).
and a waveform example of the transmission waveform (FIG. 2(b)).

The ultrasonic transmitting circuit 11 includes a driving oscillation circuit and a timer I.
It is composed of C, etc. The oscillation frequency within the time indicated by t in the transmission waveform depends on the selection of the ultrasonic transmitter 3, but is suitably in the range of several 10 kHz to several MHz. Further, FIG. 5 shows a circuit example of the ultrasonic receiving circuit 12. The ultrasonic receiving circuit 12 is composed of an amplifier and the like.

Figure 6 shows the power transmitting section (power transmitting section) 6.13 and the power receiving section (i
8.14 shows a block diagram of a power transmission unit consisting of a power reception unit) 8.14. Using high frequency, the primary coil 2
5 to the secondary coil 26 is empty u! Electric power is transmitted through 1. Although FIG. 6 shows an example of power transmission by electromagnetic coupling using a coil, it is also possible to transmit power by optical coupling using a light emitting element in the power transmitting part and a photoelectric conversion element in the power receiving part. Similar to power transmission, signal transmission through space can also be realized using an electromagnetic coupling method or an optical coupling method.

[Effects of the Invention] As explained above, according to the present invention, the ultrasonic transmitter installed at the bottom of the aquarium and the ultrasonic receiver installed above the ultrasonic transmitter in the aquarium in the vertical direction. The water level in the aquarium is detected based on the propagation time of the ultrasonic waves between the two, so the water level (weight of water 11) deforms the springs etc. that suspend the aquarium and causes damage to the outer box. Even if the positional relationship between the water tank and the water tank changes, water level detection is not affected, and even if there are bubbles on the water surface, the time it takes for the ultrasonic waves to pass through the bubbles is
Since the time taken to pass through the air is approximately the same, there is no possibility that bubbles will be mistakenly detected as the water surface, and there is an advantage that the water level in the aquarium can be detected with high accuracy.

[Brief explanation of drawings]

1 to 6 show an embodiment of a washing machine according to the present invention, and FIG. 1 is a vertical sectional view showing the internal structure of the washing machine;
Figure 2 is a block diagram showing the system configuration of the water level detection section.
Fig. 3 is a characteristic diagram showing the relationship between the water level in the water tank and the propagation time of ultrasonic waves, Fig. 4 is a diagram showing an example of an ultrasonic transmitting circuit and an example of a transmitted waveform, and Fig. 5 is a diagram showing an example of an ultrasonic receiving circuit. FIG. 6 is a block diagram showing an example of the configuration of a power transmission section that transmits power through space. 1: Outer box, 2: Water tank, 3: Ultrasonic transmitter, 4: Ultrasonic receiver, 10: Power/signal transmitter, 20: First power/signal transmitter along with FFI power/signal transmitter.
A power/signal receiving section that constitutes a signal transmission means, 30: A power transmitting/signal receiving section, 40: A power receiving/signal transmitting section that constitutes a second power/signal transmitting means together with the power transmitting/signal receiving section, 18: A plate-like member for shielding.

Claims (1)

[Claims] In a single-tank type washing machine in which a water tank serving as a washing tank and a dehydration tank is built into an outer box, an ultrasonic transmitter is installed at the bottom of the water tank and transmits ultrasonic waves vertically upward. an ultrasonic receiver that is installed vertically above the ultrasonic transmitter in the aquarium and receives ultrasonic waves from the ultrasonic transmitter, and an ultrasonic receiver that is disposed near the ultrasonic transmitter and that a first power/signal transmission means for transmitting the power and necessary signals of the ultrasonic transmitter through a space between the box side and the water tank; a second power/signal transmission means for transmitting the power and required signals of the ultrasonic receiver through a space between the box side and the water tank; A washing machine comprising: a shielding member that shields a propagation path of ultrasonic waves from other spaces in the water tank.