JPH0454479B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a drying method for a clothes dryer used in general households.

(Conventional structure and its problems) Conventionally, drying detection and termination methods for clothes dryers include electrically detecting the wetness of clothes using electrodes in the drum, or detecting the temperature difference between intake and exhaust using a thermistor, etc. This was a so-called one-point control system in which drying was completed and stopped by controlling an electric circuit.

However, when actually drying clothes at home, they are often mixed with synthetic clothes and cotton clothes such as cotton underwear and towels, and by the time the cotton has dried, the synthetic clothes become overdried, which is inconvenient. That is, there are drawbacks such as damage to synthetic clothing due to high temperatures and waste of energy.

(Object of the Invention) The present invention aims to eliminate such drawbacks, and provides a first notification when the synthetic clothing is dry, and a second notification or stop when the cotton clothing is dry. The present invention provides a drying operation method for a clothes dryer using a two-point control system.

(Structure of the Invention) A drying operation method for a clothes dryer according to the present invention is a clothes dryer that stores clothes in a rotating drum, rotates the drum to agitate the clothes, and blows hot air to dry the clothes. A sensor is provided for detecting an inflection point where the drying state of the clothes in the rotating drum shifts from a constant rate drying period to a decreasing rate drying period, and when this sensor detects the inflection point, it issues a first audible notification;
The user is informed of the time when the synthetic clothing has been dried, and after the first audible notification, the drying operation is stopped after a certain time delay or a second audible notification is made, so that the cotton clothing can be sufficiently dried.

(Description of an embodiment) Fig. 1 is a sectional view of an embodiment showing the structure of a clothes dryer according to the present invention, and 1 is a body of the clothes dryer;
Reference numeral 2 denotes a rotating drum, which is driven by a motor 3 via a belt 4 and a pulley 5. An exhaust blower 6 is driven via a belt 7 and pulleys 8 and 9. Reference numeral 11 captures dust on clothes with a filter. A door 12 opens and closes the door to throw the clothes into the rotating drum 2. Note that when the door 12 is opened, the rotation of the rotating drum 2 is stopped. A heater 13 heats the air sucked into the rotating drum 2. 1
4 is an electrode sensor in the drum, 15 is an intake side temperature detection sensor (thermistor), and 16 is an exhaust side temperature detection sensor. A control panel 17 includes a power switch 18 and a control section 19.

The operation of the above configuration will be explained below.

FIG. 2 is a graph showing the relationship between drying time and exhaust temperature.

Power supply 100V, heater 1200W, exhaust air volume ^2m3 /min,
A typical household electric dryer with a drying capacity of 2 kg (drying cloth) can mix cotton and synthetic clothing (2 kg).
Load) After washing, when the dehydrated items are put in the dehydrator and the drying operation is performed, the room temperature is 20°C, as shown in Figure 2.
℃, the exhaust temperature starts from 20℃ and decreases to about 30℃.
The temperature remains almost constant (between A and B in Figure 2),
After about 60 minutes, the exhaust temperature gradually started to rise and reached 80
After ~90 minutes (between B and C in Figure 2), the exhaust temperature is approximately 550.
Drying ends at around ℃ and the clothes are completely dry. That is,
In the figure, the period between A and B indicates a constant rate drying period, and the period between B and C indicates a period of decreasing rate drying. On the other hand, when it is experimentally confirmed that clothing containing a mixture of synthetic fibers and cotton is used, the synthetic fiber clothing first dries completely near the inflection point shown at point P in Figure 2, and then the exhaust temperature rises to approximately 55 It has been found that cotton clothing can be completely dried at a temperature difference of about 35 degrees from room temperature in the vicinity of ℃.

Therefore, by utilizing this phenomenon, the first alarm is issued at the inflection point P when the constant rate drying period changes to the decreasing rate drying period, the synthetic clothing is taken out, and the second alarm is issued when the exhaust temperature rises approximately 35 degrees above room temperature. Alternatively, if the operation is stopped, the cotton clothing can be completely dried and taken out.

Next, when the inflection point P is detected using the in-drum electrode sensor 14, it almost coincides with the point where the electrical resistance value of the clothing suddenly increases (the point where it increases to 10 to 15 MΩ). In the method of detecting the exhaust gas temperature, it is sufficient to detect and notify the point at which Δtdeg is approximately 5 degrees higher than the exhaust gas temperature t ₁ during the constant rate drying period (A-B) in FIG. 2. These detections are controlled by a control section 19 using an electronic circuit such as a microprocessor.

The cotton drying point Q is detected in Figure 2 when the difference between the exhaust temperature and the room temperature (t ₂ - t ₀ ) is about 35 degrees,
The clothes dryer is stopped via the control unit 19.

Note that a correction circuit may be incorporated into the control unit for changes in outside temperature. Furthermore, for dryers with different capacities and specifications, the constants (exhaust temperature difference, etc.) may be determined experimentally each time. Further, the first notification may be a buzzer or voice notification, but it may also be temporarily stopped at the same time. It has been experimentally found that a short stop of 3 minutes or less does not cause a change that would affect the exhaust gas temperature curve shown in FIG. 2.

The operation is extremely simple; all you need to do is to put mixed clothes of cotton and synthetic fibers (commonly used at home) into the clothes dryer and turn on the power switch 18 of the control panel 17. As drying progresses, the second
When the inflection point P in the figure is reached, a buzzer or voice notification (for example, "Please take out the synthetic clothing") will be issued, so open the door 12 to take out the synthetic clothing, close the door 12 again, and continue operation. Then, the operation will stop at point Q and all you have to do is take out the cotton clothing.

FIG. 3 is a circuit diagram of an embodiment of the present invention using intake/exhaust side temperature detection sensors 15 and 16 (thermistors), and FIG. 4 is a drum internal electrode sensor 1.
2 is a circuit configuration diagram of an embodiment of the present invention using 4, in which 20 is a notification buzzer or audio notification speaker;
1 and 22 indicate fixed resistors, and the other symbols are the same as those explained in FIG. Note that when using the drum internal electrode sensor 14, the detection of point Q in FIG. 2 is delayed by a certain time after the detection of point P (for example, the time at point P is _1.2 times the point of P1, Q ₁ minute = 1.3P). ₁
minutes. ). That is, the delay can be determined by taking the temperature difference or the time difference after point P.

(Effects of the Invention) As explained above, the drying operation method of a clothes dryer of the present invention detects an inflection point where the drying state of clothes in the rotating drum shifts from a constant rate drying period to a decreasing rate drying period. Equipped with a sensor, when this sensor detects the inflection point, it will issue a first audible notification to notify the user when the synthetic clothing has dried, and after this first audible notification, the drying operation will start after a certain time delay. Since the stop or a second audible notification is performed, even when drying a mixture of synthetic clothing and cotton clothing, the first audible notification can take out the synthetic clothing that dries quickly, and the operation can be continued. After a delay of a certain period of time, the drying operation is stopped and the cotton clothing can be taken out, which prevents overdrying of synthetic clothing from being damaged by high temperatures and saves energy and power consumption, making it extremely practical and economical. There are some advantages that a clothes dryer can offer.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view of an embodiment of the clothes dryer according to the present invention, Fig. 2 is a graph showing the relationship between drying time and exhaust temperature, and Fig. 3 is a graph showing the relationship between drying time and exhaust temperature. FIG. 4 is a circuit diagram of an embodiment of the present invention using an in-drum electrode sensor. 1...Body, 2...Rotating drum, 3...Motor, 4, 7...Belt, 5, 8, 9...Pulley, 6...Exhaust blower, 11...Filter,
12...Door, 13...Heater, 14...Drum internal electrode sensor, 15...Intake side temperature detection sensor, 16...Exhaust side temperature detection sensor, 17...
...Control panel, 18...Power switch,
19...Control unit, 20...Notification buzzer or audio notification speaker, 21, 22...Fixed resistance.

Claims (1)

[Claims] 1. In a clothes dryer that stores clothes in a rotating drum, rotates the drum to agitate the clothes, and blows hot air to dry the clothes, the drying state of the clothes in the rotating drum is kept constant. It is equipped with a sensor that detects the inflection point where the rate of drying period shifts to the decreasing rate drying period, and if this sensor detects the inflection point, it will issue the first audible notification, and after a certain time delay, the drying operation will be stopped or the drying operation will be stopped further. 2. Drying operation method for a clothes dryer that provides audible notification. 2. The drying operation method of a clothes dryer according to claim 1, wherein the inflection point is detected by using a temperature sensor to detect a point where the temperature of the exhaust gas slightly rises from a steady state. 3. The drying operation method for a clothes dryer according to claim 1, wherein the inflection point is detected at a point where the electrical resistance value of the in-drum electrode sensor rapidly increases.