JPS61290995A - Dehydration state detection apparatus of dehydrator - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a dehydration state detection device for a dehydrator, which is equipped with a weight detection device that converts a weight load acting on a dehydration tank into capacitance and detects it.

[Technical background of the invention and its problems] Conventionally, in a dehydrator as a dewatering mechanism of a washing machine with a dehydrating function or a dehydrator incorporated in a two-tub washing machine, a dehydrating system that detects the dehydration state, for example, the completion state of dehydration, has been used. Some devices are equipped with a condition detection device, such as devices equipped with an optical sensor to detect the presence or absence of water drained during dehydration, or devices equipped with a pressure sensor to detect the presence or absence of water drained during dehydration. There are devices that detect the strength of the impact pressure of the water being blown away from the aquarium.

However, when using an optical sensor, the detection accuracy decreases due to changes over time such as dirt in the drainage channel and changes in the amount of light from the light emitting element, and the measured value varies depending on the water flow, meaning that dehydration is not actually completed. Despite this, there was a problem where dehydration was incorrectly detected as complete. or,
In the case of a pressure-sensitive sensor, depending on the position of the pressure-sensitive sensor and the dehydration status, the probability of water hitting the pressure-sensitive sensor may be extremely low, and the dehydration may not actually be completed. Nevertheless, there is a problem that dehydration is erroneously detected as completed, and in either case, there is a risk of erroneous detection and there is a drawback that detection reliability is poor.

[Object of the Invention] The present invention has been made in view of the above circumstances, and its purpose is to provide a dehydration state detection device for a dehydrator that can improve the reliability of detecting the dehydration state.

[Summary of the Invention] The present invention provides a weight detection device that converts the weight load acting on a dehydration tank into capacitance and detects it, and converts weight changes into capacitance with few error factors in response to changes in dehydration state. By converting and detecting the capacitance and detecting the dehydration state based on the degree of change in capacitance, detection reliability can be improved.

[Embodiment of the Invention] Hereinafter, an embodiment of the present invention will be described as applied to a dehydrating and washing machine with reference to the drawings. First, in FIG. 1, 1 is the main body of the washing machine, and 2 is its outer box.

Reference numeral 3 denotes a water receiving tank in which a rotating tank 4 serving as both a washing tank and a dehydrating tank is disposed, and this is elastically suspended by a suspension mechanism 5. Reference numeral 6 denotes a drive unit including a motor 7 and the like, and this is provided at the outer bottom of the water receiving tank 3. 8 is a container-shaped stirring body disposed within the rotating tank 4. The suspension mechanism 5 is
A supported arm 9 attached to the outer surface of the water receiving tank 3 and an outer box 2
A support section 10 provided at the upper end, a suspension rod 11 whose upper and lower ends are trajectory between the supported arm 9 and the support section 10, and a space between the lower end of this suspension rod 11 and the supported arm 9. The first spring 12 provided in the upper end of the hanging rod 11 and the support part 1
0 and a second spring 13 provided between the rotary tank 4. The suspension rod 11 is displaced up and down depending on the relationship between the total weight of the supported objects such as the water tank 3 and the laundry and the spring forces of the first and second springs 12 and 13. Now, 14 is a weight detection device, which is the first
The first electrode 15 is located at the upper end of the hanging rod 11 on the upper cover 77 located at the upper end of the outer box 2 which is a stationary part of the washing machine main body 1. The attachment is done via a tool 18. Further, the second electrode 16 is attached to the first electrode 1 on the mounting tool 18.
5 and a dielectric material, which in this case are pivotally supported so as to face each other vertically with an air layer in between. In this case, the second electrode 1゛6G and the hanging rod 1
1 through an insulator 19, and as the weight load due to the amount of laundry and water acting on the rotating tub 4 increases, the distance between both electrodes 15 and 16 increases. In FIG. 2, 20 indicates the first electrode 15 and the second electrode.
This is a signal output circuit that outputs the capacitance between the power storage unit and the electrode 16 as a weight detection signal. It has a counter circuit that counts time, and the counted value is input as a weight detection signal to an operation control device 27 consisting of, for example, a microcomputer. Here, the change in capacitance C between the first electrode 15 and the second electrode 16 is given by the following equation.

CccC1102 ”” (1)C!
Electrostatic capacitance C1oc 1 / d”...(2) at the opposing portion of the second electrode 15.16
d: Distance between both electrodes 15.16 C2: Capacitance at the edge of both electrodes 15.16 CzOC1/1oo ((d-r)/r)...
(3) r: radius of the electrode edge As a result, the change in capacitance C as the weight load changes is as shown in Figure 3. In other words, in the region where the weight load is small, the capacitance decreases. The rate of change (degree of change) of capacitance is large and the rate of change of capacitance is small in areas where the weight is large. Note that during normal dewatering operation, the weight load pulsates due to vibrations, etc., so the change characteristics shown in FIG. 3 are obtained by taking the average value by integration or the like during actual dehydration operation. Here, the operation control device M21 calculates the rate of change of the frequency count value, which is the weight detection signal sequentially given from the signal output device 20, with respect to the count value given last time. When the rate of change reaches a large predetermined rate of change Q, a dehydration state detection signal, in this case a dehydration end detection signal, is output to stop the dehydration rotation of the rotary tank 4 by the motor 7. This predetermined rate of change Q
In Fig. 3, is the large weight value W of the rate of change of capacitance.
o (approximately 9 kg portion).

In general, the change characteristics of the weight load with respect to the dewatering time during dehydration operation are as shown in Figure 4. In the initial stage of dewatering, there is a large amount of water being dehydrated from the object to be dehydrated, so the degree of decrease in the weight load is usually small. If it is large, the degree of dehydration tends to decrease thereafter.

Therefore, in the above embodiment, when the weight of the object to be dehydrated is dehydrated in the rotation 'm4, the weight load changes in a decreasing direction, but the capacitance is To increase. Then, when the rate of change in capacitance reaches the predetermined rate of change Q (weight value Wo in FIG. 3 + time value Pa in FIG. 4), the dehydration rotation of the rotary tank 4 is stopped, and then Dehydration operation ends.

According to this embodiment, the following effects can be obtained.

In other words, since the dehydration state is detected based on the rate of change (degree of change) in capacitance due to changes in weight load, unlike the case where the presence or absence of drainage is detected using an optical sensor, it is possible to detect the presence or absence of drainage in the drainage channel. There are no erroneous detection factors such as dirt or changes in the light of the light emitting element, and unlike when a pressure sensor is used to detect the strength of water impact pressure, there is no erroneous detection factor due to the position of the pressure sensor. In general, the factors of false detection can be removed, and the reliability of detecting dehydration can be greatly improved.

By the way, instead of the capacitance conversion type weight detecting device @14 of this embodiment, it is conceivable to use a weight detecting device whose weight detecting change characteristic with respect to weight load is linear as the weight detecting device. In this case, considering that the dehydration is completed in the time period when the rate of change in weight load is small, the characteristic region where the rate of change in weight load is small, for example around the time value Pa of the characteristic line in Figure 4, is However, in actual dewatering operation, as mentioned above, the weight load pulsates, so in order to detect a region of change where the rate of change is small, it is better to take the average value by integration. However, the probability of false positive detection is high, and there are concerns that it does not match the actual situation.

In this regard, according to this embodiment, the dehydration end state, which is a dehydration state, is detected by the capacitance conversion type weight detection device 14 which shows a large capacitance change rate in a region where the weight load change rate is small. Therefore, even under circumstances where the weight load pulsates, it can be detected reliably and the detection accuracy can be improved, thereby further increasing the detection reliability.

In the above embodiment, the change in capacitance between the electrodes 15 and 16 is obtained by the displacement of the suspension rod 11 in the suspension mechanism 5, but this is due to the overlapping of the rotating tank 4, which is a dehydration tank. Any member may be used as long as it is displaced by a change in load, and for example, the capacitance between the electrodes 15 and 16 may be changed based on the displacement of the supported arm 9. Furthermore, the shape of both electrodes 15 and 16 may not be flat, but may be formed so that the mutually opposing surfaces have a convex spherical shape to increase the change in capacitance according to the above-mentioned equation (3). .

In addition, the present invention is not limited to the above-described embodiments, and may be modified in various ways without departing from the spirit, such as being applicable to a dehydrator for a two-tub washing machine or a stand-alone dehydrator. It is something that can be implemented.

[Effects of the Invention] As is clear from the above description, the present invention includes a weight detection device that converts the weight load acting on the dehydration tank into capacitance and detects the capacitance. The dehydration state is detected based on the degree of change of Overall, this has the excellent effect of significantly increasing reliability.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, in which Fig. 1 is a longitudinal sectional front view of the entire washing machine, Fig. 2 is a block diagram, Fig. 3 is a characteristic diagram of capacitance change due to change in hanging load, and Fig. 4 The figure is a graph showing the weight load change characteristics due to changes during dehydration operation i. In the figure, 1 is the washing machine body, 4 is a rotating tank (II52 water tank),
5 is a suspension mechanism, 6 is a drive unit, 11 is a suspension rod, 14 is a weight detection device, 15 is a first electrode, 16 is a second electrode, 20
21 is a signal output circuit, and 21 is an operation control device. Applicant Toshiba Corporation Figure 1 Figure 2 Figure 3

Claims (1)

[Claims] 1. Equipped with a weight detection device that converts the weight load acting on the dehydration tank into capacitance and detects it, and detects the dehydration state based on the degree of change in capacitance in this weight detection device. Features: Dehydration state detection device for dehydrators.