JPS6048797A - Automatic stopping apparatus of clothes dryer - 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) The present invention relates to an automatic stop device for a clothes dryer that dries clothes with hot air.

(Prior art) Fig. 1 shows an example of a clothes dryer, in which 1 is the clothes/cloths to be dried, 2 is a rotating drum, 3 is a blower, and 4 is a rotating drum.
is a motor that rotates the blower 3 and decelerates and rotates the drum 2; 5 is a heater; 6 is a flow of intake air; 7 is a flow of high-temperature air heated by the heater 5; The clothes/fabrics 1 are dried by hitting the clothes.

Further, 8 is a flow of exhaust air, and the temperature of this exhaust air 8 is lower than that of the high-temperature air 7 due to the amount of heat taken away when the moisture in the clothing/fabrics 1 evaporates and the amount of heat taken away by the drum 2. .

In addition, 9 is a temperature-sensitive element that measures the temperature of the exhaust gas 8, which is referred to here as a negative characteristic thermistor and a waist exhaust thermistor, and 10 is a temperature-sensitive resistance element that measures the temperature of the intake air, which is referred to here as a negative characteristic thermistor. It is called a characteristic thermistor and an intake thermistor. The resistance value of the negative characteristic thermistor 9.10 decreases as the temperature increases.

As the drum 2 rotates, the clothing/cloth B1 falls from top to bottom, the clothing/cloth 1 is loosened, and the high-temperature air 7
dried by The degree of dryness of the clothes/fabric 1 is closely related to the temperature difference T between the exhaust air temperature and the intake air temperature of the clothes dryer.

FIG. 2 shows the relationship between the "temperature difference of 1" between the exhaust gas temperature and the intake air temperature and the degree of dryness of the clothes with respect to the elapsed time after the clothes dryer was operated.

Note that the dryness of clothing is expressed by the following formula.

When you operate a current weight clothes dryer for clothes and fabrics, the first thing that happens is from 0 to A in Figure 2.
The exhaust temperature continues to rise until the point. Is the intake air temperature almost equal to room temperature?It doesn't change much, and even if it changes, it will be reflected as a change in the exhaust temperature.If you take the temperature difference T between the exhaust temperature and the intake air temperature, you can find the intake air temperature. The change in temperature is not reflected by a temperature difference of 1°. From point A to point B in FIG. 2, the temperature difference between the exhaust gas and the intake air is almost constant. This is because the moisture in the clothing/fabric 1 evaporates efficiently and the latent heat is taken away, so that the exhaust temperature does not rise. After the 13th point, the moisture in the clothing/fabric 1 has decreased considerably, so the amount of latent heat taken away is reduced, and the temperature force of the clothing/fabric is rising, causing the exhaust temperature to rise rapidly. I'll come. At point 0, the degree of dryness becomes 100%. In other words, by measuring the temperature difference between exhaust air and intake air, it is possible to estimate the degree of dryness of clothing and fabrics to some extent. However, the $2 diagram shows the change in the temperature difference between the exhaust air and the intake air in general, and the time characteristics of the temperature difference between the exhaust air and 11 air when drying actual clothes and cloth depend on the thickness of the cloth. etc., as shown in Figure 3.

The curve (a) in FIG. 3 shows the drying of thin cloths and synthetic fiber cloths, that is, the time characteristics of the temperature difference, and the degree of dryness reaches 100% at point 01. Also, the curve in Figure 3 (
B) shows the drying of cloth of standard thickness or cloth such as cotton, and the degree of dryness reaches 100% at point C2. The curve (c) shows the drying of very thick cloths and cloths such as wool (wool, etc.), and the dryness is 100 at 03 points.
reach %.

From these, thin cloth has a dryness rate of 10 with a very small temperature difference.
It can be seen that it reaches 0%. Therefore, it is necessary to change the temperature difference between the exhaust air and the intake air, which corresponds to 100% dryness, depending on the type of cloth.

By the way, as an automatic stop device for clothes dryers that changes the temperature difference between exhaust air and intake air corresponding to 100% dryness depending on the type of cloth, the one shown in Fig. 4 has been proposed. . In Figure 4, 4, 5, 9.1
0 are a motor, a heater, an exhaust thermistor, and an intake thermistor, which are the same as those shown in FIG. Further, 11 is a commercial power source, 12 is a momentary-on operation switch, 13 is a momentary-off stop switch, and 14 is a contact point of a relay RV having a coil of 14°. In addition, 15 is a voltage comparator (hereinafter referred to as a comparator), which has an input terminal, a Q input terminal, and an output terminal, and when the potential of the input terminal is higher than that of the input terminal or the input terminal, the output terminal is In the opposite case, the output terminal becomes a low level. 16 is N1)N) run star, 17, 18, 19 are diodes, 20
is a constant voltage diode. 21 is a capacitor, 22
~30 is the resistance. 31 is a select switch.

The conventional automatic stop device for a clothes dryer operates as follows.

When the power supply 11 is turned on and the operation switch 12 is temporarily turned on, the diode 17, resistor 22, and capacitor 21
The DC voltage rectified and smoothed is further made constant by a resistor 23 and a constant voltage diode 20, and is applied from the resistor 23 to the electronic circuit on the right side.

The voltage at the intersection of the exhaust thermistor 9 and the intake thermistor 10 changes in proportion to the temperature difference between the exhaust and intake air. At the start of operation, the temperature difference between the exhaust and intake air is zero, so the potential at the intersection of the exhaust thermistor 9 and the intake thermistor 10, that is, the potential at the O input terminal of the comparator 15, is at a low level. Therefore, since the potential of the e input terminal of the comparator 15 is lower than the potential of the input terminal of the comparator 15, the output terminal becomes a high level, the transistor 16 is turned on, the coil 14' of the relay Ry is turned on, and its contact 14 is turned on. is turned on and self-holds. And motor 4 and heater 5
is energized.

Since the resistors 24, 25, and 26 have different resistance values, the potential of the input terminal of the humperator 15 can be changed by pressing the select switch 31 (up).

Clothes/fabrics 1 that change as shown by the curve in Fig. 3 will be 100% dry when the temperature difference between the exhaust air and the intake air is relatively small, so the input terminal of the comparator 15 Set the potential low.

On the other hand, for clothing/fabric 1 that changes as shown by the curve (C) in Figure 3, the temperature difference between the exhaust air and the intake air is relatively large and it is 100% dry at this point, so the comparator 15 ■ Set the voltage of the input terminal high.

When the degree of dryness of the clothing/cloth 1 reaches 100%, the potential at the intersection of the exhaust thermistor 9 and the intake thermistor 10 rises, and the potential at the O input terminal of the air filter 15 becomes higher than the potential at the input terminal A. , the output terminal becomes low level,
Transistor 1G is turned off and relay Ry coil 14
' is turned off, the contact 14 is also turned off, and self-holding is released.

Then, the motor t and heater 5 are turned off. Note that the stop switch 13 is used when stopping manually.

As described above, this automatic stop device may be convenient because it automatically stops the drying operation, but it is troublesome in that the type of cloth and the type of fiber must be selected using the select switch 31. In addition, if there are various types of cloth to be dried, press the select switch 31.
The drawback is that it is difficult to know how to match it properly.

(Object of the Invention) Therefore, an object of the present invention is to automatically set the reference temperature difference between the exhaust air temperature and the intake air temperature corresponding to 100% dryness according to the conditions, thereby improving the The drying operation can be stopped automatically without the need for manual selection operations depending on the situation, and even when there are mixed types of clothes to be dried, the timing of stopping the drying operation can be adjusted appropriately to prevent whitening. The purpose of the present invention is to provide a convenient automatic stop device for drying clothes that automatically stops the drying operation.

(Structure of the Invention I#) In order to achieve the above object, the structure of the present invention includes a detection means for detecting a temperature difference (T) between the air temperature and the intake air temperature;
The above temperature difference (T1) after a certain period of time has passed from the start of drying operation
), a setting means for setting a reference temperature difference (T2) that is regarded as the temperature difference at the end of drying based on the actual temperature difference (T) between the exhaust gas temperature and the intake air temperature and the standard temperature difference ( T2
>, and the drying operation is automatically stopped when the actual temperature difference (T) becomes larger than the reference temperature difference ('F2). do.

(Example) Hereinafter, the present invention will be explained in detail with reference to illustrated embodiments.

In Figure 5, 4, 5, 9, 10, 11.12°13
．． 14.14' is the commercial power supply for the motor, heater, exhaust thermistor, and intake thermistor, respectively.

Momentary-on operation switch, momentary-off stop switch, relay 1'< Y contact, relay R
, y, and is the same as that shown in FIG.

32 is a step-down transformer; 33 is a microcomputer; this microcomputer 33 has a built-in comparator 33' and a D/A converter 33'; Contains input circuits, output circuits, etc. The microcomputer 33 has a comparator 331 and a D/
The A converter 33'' forms an A/D converter, and the analog voltage input to the AID input terminal can be converted into a digital value for storage and calculation.

Also, 34.35 is NPN) Ranno Matayu, 36°37+
38 is a light emitting diode, 39 is a constant voltage diode, 40
．． 41, 42, 43.44 are diodes, 45, 46
is a capacitor, and to 47/5G is a resistor.

The automatic stop device for a clothes dryer having the above structure operates as follows.

First, as shown in step 1 in FIG. 6, when the operation switch 12 is turned on, the transformer 32 is energized, and the diodes 40, 41, the capacitor 45, the resistor 50, and the voltage regulator diode 39 perform rectification, smoothing, and regulation. The energized DC voltage is applied to the microcomputer 33.

Then, as shown in step 2 in FIG. 6, the first output of the microcomputer 33 becomes high level, the transistor 34 is turned on, the coil 14 of the relay Ry is turned on, and its contact 14 is turned on. is turned on, and relay Ry self-holds. Then, the motor 4 and heater 5 are turned on to start drying operation. , On the other hand, a rectangular wave synchronized with the commercial power supply 11 is generated by the diode 42 and the transistor 35 to the microcomputer 3.
3's INT terminal. This enables the microcomputer 33 to calculate time.

Next, in step 3, a certain period of time (for example, 15
1', +1 to determine whether the elapsed time has elapsed or not, and when it has elapsed, in step 4, the temperature difference T between the air and the intake air is measured by the signal input to the A/D input terminal of the microcomputer 33, Let this value be T. Curve in Figure 3 (A),
The equivalents of (b) and (c) are T, a, and TI, respectively.
It's mouth ITI ha. This temperature difference] Determine in step 5.6 which of the curves (a), (b), and (c) in Figure 3 it is closer to, and select the step ? , the reference temperature difference T2 at 8.9
Set. That is, as shown in FIG. 3, T, A
<T, B The numerical values T, AT, B are set in advance,
Then, when T1<T, in step 7, the reference temperature difference T2A between the exhaust air and the intake air when 100% dry is read out from the memory circuit and set (see curve (a) in FIG. 3). Also,
Outside of T, 8≦T, <T, H, step 1' sets the reference temperature difference T2B between exhaust and intake air at 100% drying (3rd
(See curve (b) in the figure). In addition, when T1≧T, B, in step 9, the reference temperature difference T between exhaust air and intake air when 100% dry
2c (see curve (c) in Figure 3). In other words, the reference temperature difference T2 between the exhaust air and the intake air when 100% dry is changed based on the detected temperature difference T1 after a certain period of time has passed after the start of operation.

Naturally, T2A <'T2B< T2C. When one of the above reference temperature differences T2A, T2B, and T2c is determined, one of the second, third, and fourth outputs of the microcomputer 33 is set to a high level as shown in steps 10 and 11.12. to turn on any of the light emitting diodes 38, 37, and 36. For example, if the reference temperature difference T2Δ is determined, the actual temperature difference T between the exhaust and intake air is detected by the A/D input terminal of the microcomputer 33, and in step 13, the temperature difference T2Δ is determined.
When it is determined that the temperature difference T2Δ has become greater than the reference temperature difference T2Δ, the first output of the microcomputer 33 is set to a low level in step 14, and the filter 14' of the relay Ry is turned off. Then, the contact 14 is turned off, so the holding of the relay Ry is released, the motor 4 and the heater 5 are turned off, and the drying operation is stopped.

In this way, this automatic stop device detects a temperature difference of 1 between the exhaust temperature and the intake air temperature after a certain period of time has passed from the start of drying operation.
゛Based on I, a reference temperature difference T2 corresponding to 100% dryness is automatically set, and when the actual temperature difference T exceeds the reference temperature difference T1, the drying operation is automatically stopped. It is convenient because there is no need for manual selection operations according to the drying process, etc., and even when the types of drying machines and cloths are mixed, the timing to stop the drying operation can be optimally set and the drying operation can be stopped automatically.

In the above example, the temperature difference T1 between the exhaust air and the intake air after a certain period of time has elapsed from the start of the drying operation was divided into three stages, and the reference temperature difference T2 was divided into three stages accordingly, but these are divided into more detailed stages. It is also possible. In addition, in this example, the temperature difference T1 after 15 minutes was used as the temperature difference T1 between the exhaust air and intake air after a certain period of time from the start of the drying operation, but the temperature difference T1 between the exhaust air and intake air over time was The temperature difference T1 between the exhaust gas and the intake air when the temperature becomes very small, that is, when it becomes constant, may be used.

(Effects of the Invention) As is clear from the above explanation, the automatic stop device for clothes dryers of the present invention is configured as described above, and therefore does not require manual selection and fabrication according to the type of clothing or fabric. without saying,
It is convenient because it can automatically stop, and even when there are mixed types of clothes or fabrics to be dried, the drying operation can be stopped automatically by setting the optimal time to stop.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram of a clothes dryer, Figs. 2 and 3 are elapsed time-temperature difference characteristic diagrams, Fig. 4 is a circuit diagram of a conventional example, and Fig. 5 is a circuit diagram of an embodiment of the present invention. FIG. 6 is a flowchart. 1...Clothing/cloth, 2...Drum, 3...Blower, 4...Motor, 5...Heater, 9...Exhaust thermistor, 10...Intake thermistor, 33 ...
Microcomputer-0 Patent applicant Sharp Corporation

Claims (1)

[Claims] (1) In a clothes dryer that detects exhaust temperature and intake air temperature, estimates the degree of dryness of clothes, and automatically stops drying operation, detects the temperature difference (T,) between exhaust temperature and intake air temperature. a detection means, a setting means for setting a reference temperature difference (T2) that is regarded as a temperature difference at the end of drying based on the temperature difference (T, ) after a certain period of time has elapsed from the start of drying operation; and a comparison means for comparing the actual temperature difference (T) with the intake air temperature and the reference temperature difference (T2), the actual temperature difference (T) being more natural than the reference temperature difference (T2). An automatic stop device for a clothes dryer, characterized in that the drying operation is automatically stopped when the condition occurs.