JPS59222194A - Clothing 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 This invention forms a circulation path for hot air using a rotating drum, a circulation fan, a heating source, and a heat exchanger, and cools the heat exchanger to cool air from clothes stored in the rotating drum. This invention relates to a so-called dehumidifying type clothes dryer that condenses and recovers moisture and stops operating after a certain level of finished drying.

FIG. 1 is a sectional view showing a conventional clothes dryer disclosed in, for example, Japanese Patent Application Laid-open No. 55-70300.
In the figure, 1 is an outer box, and 2 is a drum rotatably supported within the outer box 1. This drum 2 is driven by a motor 4 via a drum belt 3.

An exhaust duct 5 is provided at the rear of the drum 2, and a circulation fan 6 is stacked inside the exhaust duct 5. This circulation fan 6 is rotationally driven by a motor 4 via a fan belt 7.

Further, 8 indicates a heat exchanger. One end of this heat exchanger 8 is connected to the intake duct 5, and the other end is connected to the intake duct 9. A heater 10 is installed within this intake duct 9.

This heater 10 heats air within a circulation path formed by the drum 2, exhaust duct 5, heat exchanger 8, and intake duct 9.

A cooling fan 11 is provided near the heat exchanger 8 and blows outside air toward the heat exchanger 8 to cool the heat exchanger 8. This cooling fan 11 is rotationally driven by a motor 4 via a fan belt 12.

A drain pipe 13 is provided at the bottom of the intake duct 9, and the drain pipe 13 is configured to discharge water condensed by the heat exchanger 8 (hereinafter referred to as dehumidified water) to the outside. A polarization 14 is provided on the inner wall of the drain pipe 13 to detect the presence or absence of dehumidified water.

Note that 15 is a door that covers the clothes slot on the front side of the outer box 1.

Next, the operation of the clothes dryer shown in FIG. 1 will be explained. When an object to be dried is placed in the drum 2 and a drying operation is started, the drum 2 is rotated around a horizontal axis by the power of a motor 4 via a drum belt 3.

At the same time, the circulation fan 6 and the cooling fan 11 driven by the motor 4 operate, and the circulation fan 6 sucks air from the drum 2 and passes it through the exhaust duct 5, the heat exchanger 8, and the intake duct 9. Circulate the air so as to blow it into the drum 2 again (see below).

This air is called circulating air).

At this time, the circulating air heated by the heater 1o in the intake duct 9 evaporates moisture from the material to be dried that has been put into the drum 2. Therefore, the air flowing out from the drum 2 becomes hot and humid.

On the other hand, the cooling fan 11 takes in outside air and blows it to cool the heat exchanger 8. The high temperature and humid air is transferred to a heat exchanger 8.
When the air passes through the air, it is dehumidified by heat exchange with the outside air.
The dehumidified water is discharged to the outside from the drain pipe 13.

FIG. 2 is a block diagram showing a control device for the clothes dryer shown in FIG. 1. In the figure, the same parts as in FIG. 1 are given the same reference numerals. The determination circuit 20 inputs the detection signal from the electrode 14 and determines the presence or absence of dehumidified water.A timer 21 is connected to the output terminal of the determination circuit 20.

When the determination circuit 20 determines that the dehumidified water has run out,
The timer 21 stops power supply to the motor 4 and the heater 10 after counting a certain period of time.

Figure 3 is a drying characteristic diagram of the clothes dryer mentioned above.
The operation will be further explained in detail with reference to the drawings. This Figure 3 shows the dryness of clothes and the amount of dehumidified water with respect to drying time. Graph A in the figure shows the dryness of clothes, and graph B shows the change in the amount of dehumidified water per unit time.

The dryer starts operating fully and dehumidified water starts to be discharged outside a few minutes later. When the degree of dryness exceeds a certain value, the amount of dehumidifying water becomes constant, and the drying progresses.When the degree of dryness approaches the finished dryness, the amount gradually decreases and finally reaches zero. However, at this point, the clothes are not yet dry.

When the dehumidified water passes through the drain pipe 13, the electrode 14 sends a signal to the determination circuit 20. Since the dehumidified water intermittently flows out of the drain pipe 13, the signal becomes a noculus.

When the determination circuit 20 determines that the detected i9 pulse from the electrode 14 has disappeared, it activates the timer 21. When the timer 21 measures a preset time t, the power supply to the motor 4 and the heater 10 is stopped, and the drying operation is ended.

In this way, in conventional clothes dryers, the presence or absence of dehumidifying water is determined, and after detecting that the dehumidifying water has run out,
After a predetermined period of time, the drying operation is completely stopped.

However, the time from when the dehumidifying water runs out until the finished dryness is reached varies depending on the amount of clothing.

For this reason, depending on the amount of clothing, it may become over-dry.

Further, there were drawbacks such as insufficient drying.

This invention was made in order to eliminate the above-mentioned conventional drawbacks. Two temperature sensors with different time constants are installed at the heat exchanger and cooling system outlet, and the detected temperature difference between the two is used to dry clothes. To provide a clothes dryer that can automatically stop operation at a certain level of finished drying without being affected by the amount of clothes by indirectly detecting the degree of drying.

Embodiments of a clothes dryer according to the present invention will be described below with reference to the drawings. FIG. 4 is a sectional view showing the configuration of one embodiment. In FIG. 4, in order to avoid duplication, the same parts as those in FIG. 1 will be given the same reference numerals and their explanation will be omitted, and the parts different from those in FIG. 1 will be mainly described.

As is clear from comparing Figure 4 with Figure 1,
In the figure, the parts indicated by reference numerals 30 onward are different from those in FIG.
This is a characteristic feature of this invention.

That is, it is the 30h first temperature detector.

This first temperature detector 30J-1: installed at the outlet of the heat exchanger 8, and has a detection response with a time constant T1.

Further, 31 is a second temperature detector. This second temperature sensor 31 is connected to the heat exchanger 8 near the first temperature sensor 30.
It has a detection response with a time constant T2 that is relatively larger than the above-mentioned time constant.

FIG. 5 is a block diagram showing a control device for the clothes dryer shown in FIG. 4. In this FIG. 5, the outputs of the first temperature detector 30 and the second temperature detector 31 are
2.

This temperature difference detector 32 detects the difference between the output of the first temperature detector 30 and the output of the second temperature detector 31, and outputs Δ
S is sent to one input terminal of the temperature comparator 33.

The other input terminal of this temperature comparator 33 has a set temperature S1
is now entered. This temperature comparator 33 compares the magnitude relationship between the output ΔS of the temperature difference detector 32 and the set temperature S1, and sends an output to the motor 4 and the heater 1O according to the deviation.

Next, the operation of the clothes dryer of the present invention constructed as described above will be explained with reference to the characteristic diagrams shown in FIGS. 6 and 7. FIG. 6 is a characteristic diagram of the relationship between the drying time and the air temperature at the outlet of the cooler system of the heat exchanger 8 (hereinafter abbreviated as discharge temperature).

In FIG. 6, the graph A1 shows the characteristic when the amount of clothes to be dried is small, and corresponds to the output temperature No. 18 of the first temperature detector 30 having a detection response with a small time constant T1.

Graph A2 indicated by a broken line in FIG.

This is the output temperature layer number of the second temperature detector 31 at that time. Since the second temperature detector 31 is set to have a time constant T2 that is relatively larger than the time constant T1 of the first temperature detector 30, there is a delay time in response to a change in the discharge temperature.

Further, the characteristic shown in graph B1 shows the output signal of the first temperature sensor when there is a large amount of clothing, and similarly, the graph B2 shows the output signal of the second temperature sensor 31.

Initially, the heat supplied from the heater 10 is used to raise the temperature of the clothes and the moisture contained therein, and as the circulating air temperature rises, the discharge temperature also rises.

After that, the clothes dry together with the person, but the heat is consumed as latent heat, so the temperature of the circulating air does not change much, and the amount of moisture condensed by the heat exchanger also does not change much, so the discharge temperature decreases. a'? Ahead! 7. Don't become a father.

Eventually, when the drying temperature approaches 100%, the heat is consumed as heat sensitive again, so the temperature of the circulating air rises rapidly. However, since the amount of moisture condensed in the heat exchanger 8 decreases, The quantity will decrease and the temperature will drop to the discharge temperature.

The temperature difference between the first temperature detector 3o and the second temperature detector 531 (hereinafter simply referred to as temperature difference ΔS) is detected at the beginning of drying and at the end of drying, as shown in FIG. This is because the second temperature detector 31, which has a large time constant, cannot follow the original temperature change due to a sudden change in the discharge temperature.

FIG. 7 is a characteristic diagram showing the temperature difference ΔS with respect to the drying time. As is clear from FIG. 7, the temperature difference ΔS becomes a positive temperature difference in the early stage of drying, and the temperature difference ΔS becomes a positive temperature difference during the drying stage.

In the middle stage of drying, the discharge temperature becomes a constant value, and at this point, the temperature difference ΔS becomes zero.

Thereafter, as the drying progresses and approaches second-finish drying, the discharge temperature decreases and the temperature difference ΔS becomes a negative value. The rate of change of this decreasing temperature is larger in the characteristic of graph A1 in which the amount of clothing is small than in the characteristic of graph B1 in FIG. 6 in which the amount of clothing is large, and is inversely proportional to the amount of clothing.

Further, the temperature difference ΔS increases with time as the rate of change in the discharge temperature increases, that is, the amount of clothing decreases.

On the other hand, if finish drying is defined as the point in time when the degree of dryness of the clothes reaches 100%, the discharge temperature at the time of finishing becomes lower as the amount of clothes increases. From this, the response time constant T1 of the first temperature detector 30 and the response time constant 31 of the second temperature detector 31
By appropriately selecting the response time constant T2, it is possible to indirectly detect the degree of dryness of clothing based on the temperature difference ΔS.

That is, if the temperature difference during finish drying is set to the set temperature S1, in the case of a small amount of clothing, the rate of change in discharge temperature is large, so the discharge temperature at which the temperature difference ΔS reaches the set temperature S1 is high; In addition, if there are many clothes, the rate of change in the discharge temperature will be small.

The discharge temperature at which the temperature difference ΔS reaches the set temperature S1 becomes lower.

The set temperature S1 is set to a temperature difference ΔS with a degree of dryness of 100%. The temperature comparator 33 has its input, j, and temperature difference ΔS.
When the set temperature s1 matches, the motor 4 and heater 1
o, and stop the dryer operation.

By the way, in the above explanation, it was mentioned that when two temperature detectors, the first temperature detector 3° and the second temperature detector 31, are used, the response speed is reduced by using only one temperature detector. The above operation can also be expected by obtaining different characteristics randomly or by calculation.

Further, in the above embodiment, the operation of the dryer was immediately terminated after the completion of drying was detected, but the power supply to the heater 1o was stopped,
Cold air operation may also be performed.

As described above, according to the clothes dryer of the present invention, when the heat exchanger cooling system discharge temperature is close to finishing drying, the rate of change in the heat exchanger cooling system discharge temperature at the time of finishing is correlated with the amount of clothes. Using this method, temperature detectors with different detection response speeds were installed at the heat exchanger cooling system outlet, and the dryness of the clothes was indirectly detected from the detected temperature difference between the two. The operation can be completed with a certain level of final drying regardless of the amount of drying.

[Brief explanation of drawings]

Fig. 1 is a cross-sectional view of a conventional clothes dryer, Fig. 2 is a block diagram of the control device of the clothes dryer shown in Fig. 1, and Fig. 3 is a comparison of the drying time ζ of one reading of clothes drying in Fig. 1. A characteristic diagram showing the relationship between the degree of dryness and the amount of dehumidified water, FIG. 4 is a sectional view showing the configuration of an embodiment of the clothes dryer of the present invention, and FIG. 5 is a block diagram of the control device of the clothes dryer shown in FIG. 4. Figure 6 is a characteristic diagram showing the heat exchanger cooling system discharge temperature with respect to the drying time of the clothes dryer in Figure 4, and Figure 7 shows the temperature difference between the two temperature detectors in the control device in Figure 5. It is a characteristic diagram. 1... Outer box, 2... Drum, 4... Motor, 5...
...Exhaust duct, 6...Circulation fan, 8...Heat exchanger, 9...Intake duct, 10...Heater, 11...
- Cooling fan, 30... First temperature detector, 31...
-Second temperature detector, 33...temperature detector. Note that the same reference numerals in the figures indicate the same or corresponding parts. Agent Masuo Oiwa Figure 1 Figure 2 Figure 3 Figure 4

Claims (4)

[Claims] (1) A drum rotatably installed inside the outer box, heated air is supplied into the drum via a heat source, and the high-temperature and humid air exhausted from this drum is heated again by the heat source after passing through a heat exchanger. A circulating means is formed, a means for making the outside air orthogonally cross within the heat exchanger by this circulation means and a cooling fan, a means is provided at the outlet of the cooling system of the heat exchanger to detect the temperature thereof, and the temperature detection response speed is different. A clothes dryer comprising a temperature detection means having a characteristic. (2) The clothes dryer according to claim 1, wherein the temperature detecting means includes a first temperature detecting means and a second temperature detecting means having different temperature detection response speeds. (3) The clothes dryer according to claims 1 and 2, characterized in that the operation of the clothes dryer is stopped when temperature detection outputs having different temperature detection response speeds reach a predetermined relationship. (4) The clothes dryer according to claim 1, 2 or 3, wherein the drying operation is performed for a predetermined period of time from the start of drying.