JPH07695A - Clothes dryer - Google Patents

Abstract

PURPOSE:To enhance the reliability of drying by changing the output of a heater to a low output regulated value at a point of time when time passes to some degree and the heater output is lowered to lower the temperature in a drying chamber, even when the heater is switched from high output to low output by clogging detection during drying operation. CONSTITUTION:When a start key is operated in drying operation, a heater inlet temperature is detected by a thermosensitive element 26, a clogging current value forming the current value carried to a heater device 19 when the heater device 19 or a lint filter 7 is clogged is determined on the basis of the detected temperature. When the heater device 19 or the lint filter 7 is clogged during drying operation to lower the blowing air quantity, and the current value is reduced lower than the clogging current value, the heater device 19 is operated at a low output. After the lapse of a prescribed time (about 10 minutes), the high output values of a prescribed value set for automatic end detection, limiter value and high limiter value are changed to low output values to continue the drying operation.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a clothes dryer.

[0002]

2. Description of the Related Art Conventionally, in a clothes dryer, a lint filter is provided at the outlet of a drying drum. Further, a honeycomb heater is used as a heating means, and dry air is passed through the heater for heating. For this reason, if the filter or the heater is clogged, the air flow rate of the dry air is reduced and the temperature near the outlet of the heater is abnormally increased, which may damage components such as the door near the heater.

To prevent this, for example, Japanese Unexamined Patent Publication No.
As disclosed in Japanese Patent No. 128799 (D06F58 / 28), when a clogging of a heater or a filter is detected, the heating power of the heater, that is, the output is reduced to continue the drying operation.

Further, in such a clothes dryer,
A temperature sensor for detecting the temperature inside the drying drum is provided, and the drying operation is terminated when at least the measured data value created based on the temperature detected by the temperature sensor reaches a predetermined specified value.

As an example, a dry air is sent into the drying drum, the dry air discharged from the drum is heat-exchanged with the outside air by a heat exchange means, and then reheated by a heater. A temperature sensor is provided at each of the inlets, and the difference between the temperatures detected by both temperature sensors is set as a reference value A after a predetermined time from the start of operation, and then this temperature difference (corresponding to the actual measurement data value) is previously tested to the reference value A In some cases, the drying operation is stopped when the value reaches a value (corresponding to the specified value) obtained by adding the predetermined value B specified by the above. Here, the temperature sensor provided at the drum outlet is for indirectly detecting the temperature inside the drum by the temperature of the exhaust air.

The larger the output of the heater, the higher the temperature inside the drum during the drying operation. Therefore, the temperature of the drum when the clothes are sufficiently dried also increases as the output of the heater increases. Further, if the outside air temperature is the same, the temperature difference between the drum outlet and the heater inlet described above increases as the output of the heater increases.

Therefore, the specified value is different between when the heater operates at high output and when it operates at low output, and is smaller at low output.

[0008]

In the conventional clothes dryer, when the clogging is detected and the output of the heater is lowered, the specified value is also changed accordingly. That is, the specified value becomes a small value. However, until then, the heater was operating at high output, so the temperature inside the drum was high, and as soon as the specified value was changed, the measured data value had reached the specified value. There was a risk that the drying operation would end even though the clothes were not sufficiently dried.

The present invention relates to an improvement of a clothes dryer and solves such a problem.

[0010]

The clothes dryer of the present invention comprises:
A drying chamber for accommodating clothes, a blowing unit for feeding a drying air into the drying chamber, a heating unit for heating the drying air, which can be switched to a high output or a low output, and a temperature detecting unit for detecting the temperature in the drying chamber. And a specified value for low output smaller than the specified value for high output set corresponding to the case where the heating means operates at high output and a low output set when the heating means operates at high output. The storage means for storing, the adopting means for adopting a specified value among the specified values according to the output state of the heating means, and the measured data value created based on at least the temperature detected by the temperature detecting means are adopted. The end means for ending the drying operation when the specified value adopted by the means is reached, and the operation of the adoption means is delayed by a predetermined time when the heating means is switched from the high output to the low output during the drying operation. Is obtained by a delay means that.

[0011]

[Function] Even if the heater is operating at a high output and the output is switched to a low output due to detection of a clogging or the like, the high output specified value is not immediately changed to the low output specified value for a certain period of time. After a lapse of time, when the output of the heater decreases and the temperature in the drying chamber decreases, the value is changed to the low output specified value.

[0012]

Embodiments of the present invention will be described with reference to the drawings.

In FIG. 4, 1 is a clothes dryer of this embodiment, 2 is an outer frame thereof, and has a clothes inlet 3 on the front surface. Reference numeral 4 denotes a horizontal drum that is a rotatably supported shaft in the outer frame 2 and serves as a drying chamber. An opening is formed in the front surface corresponding to the clothes inlet 3. An exhaust port 6 is provided in the center of the rear surface of the drum 4, and a lint filter 7 is disposed in the exhaust port 6. Reference numeral 2a is a support plate which is provided from the outer periphery of the clothes insertion port 3 and supports the front surface of the drum 4, and an intake port 5 is provided in the lower portion. Reference numeral 8 is a door for opening and closing the clothes inlet 3.

Reference numeral 9 denotes a fan casing provided at the rear of the drum 4, and 10 denotes a heat exchanging type double-sided fan which serves as an air blower provided so as to divide the inside of the fan casing 9 into a circulation air passage 11 and a cooling air passage 12. Is. 13 is the exhaust port 6
And a circulating air passage 11 to communicate with each other, a communication port opened in the fan casing 9 and a seal member 14 provided to reliably guide the dry air discharged from the exhaust port 6 to the communication port 13. Reference numeral 15 is an inlet provided at the center of the rear surface of the outer frame 2 for introducing the outside air into the cooling air passage 12, and 16 is an outlet provided also at the lower portion of the rear surface of the outer frame 2 for discharging the introduced outside air. is there.

Reference numeral 17 is a circulation duct which connects the circulation air passage 11 and the intake port 5 of the drum 4, and a drain hole 18 is provided at the lowermost position. 19 is this circulation duct 17
A heater device serving as a heating unit disposed on the side of the intake port 5 inside, and includes two sets of honeycomb-shaped semiconductor heaters of a first heater 19a and a second heater 19b. This heater device 19
Turns on both the first heater 19a and the second heater 19b.
It is possible to operate at high output (strong) and low output (weak) by switching between turning on and turning on only the first heater 19a.

Reference numeral 20 denotes an induction motor, which is a drum pulley 2
1 and a drum belt 22 to connect to the drum 4, and a fan pulley 23 and a fan belt 24 to connect to the double-sided fan 10.

Thus, at the time of drying, the drum 4 is rotated at a low speed and the double-sided fan 10 is rotated at a high speed by the rotation of the motor 20. At the same time, the heater device 19 is turned on. The dry air generated by the rotation of the double-sided fan 10 and heated by the heater device 19 circulates through the circulation air passage 11, the circulation duct 17, and the drum 4 to exchange heat with the clothes in the drum 4. At the same time, the outside air is introduced into the cooling air passage 12 by the rotation of the double-sided fan 10 to cool the double-sided fan 10 itself. The dry air after heat exchange in the drum 4 is the double-sided fan 10.
Is cooled by contacting with, and the moisture in the dry air is condensed, flows down in the dry air passage 11, and is discharged from the drain hole 18.

Reference numeral 25 is a first thermosensitive element which is provided in the vicinity of the communication port 13 and serves as a temperature detecting means. The temperature of the exhaust air discharged from the drum 4 in order to detect the temperature inside the drum 4 (drum outlet temperature). ) Is detected. Numeral 26 is provided in the vicinity of the inlet of the heater device 19 in order to detect the temperature of the dry air (heater inlet temperature) before being reheated by the heater device 19 after heat exchange by the double-sided fan 10. 2 is a heat sensitive element, and 27 is the temperature of the dry air after being reheated by the heater device 19 (heater outlet temperature)
The third heat-sensitive element is provided in the vicinity of the outlet of the heater device 19 for detecting These heat sensitive elements 25, 26, 27
For the above, a thermistor is used to convert the detected temperature into an analog voltage value and output it.

FIG. 5 shows a control mechanism of the clothes dryer of this embodiment, and 28 is a microcomputer (hereinafter referred to as a microcomputer), which is a control unit 29 serving as an adopting means, terminating means and delaying means of the present invention. The storage unit 30 serves as a storage unit, the timer 31 serves as a delay unit, the A / D converter 32, and the like.

33 is a selection key for various driving courses and conditions,
An operation key group including a start key for starting / stopping the dry operation, 34 is a door switch for detecting opening / closing of the door 8, and 35 is a current detection circuit for detecting an input current of the heater device 19. The operation key group 33, the door switch 34, and the current detection circuit 35 are provided in the thermosensitive element 2
5, 26 and 27 are connected to the input side of the microcomputer 28.

An LED display circuit 36 is connected to the output side of the microcomputer 28 and displays the progress of the drying operation. A buzzer circuit 37 is also used to notify the end of operation or abnormal operation. 38 is the heater device 19 and the motor 2
A load drive circuit for driving 0, which is composed of a triac or the like and is also connected to the output side of the microcomputer 28.

The microcomputer 28 operates the operation key group 3
3, the LED based on the inputs from the door switch 34, the current detection circuit 35 and the heat sensitive elements 25, 26 and 27.
A control signal is sent to the display circuit 36, the buzzer circuit 37, and the load drive circuit 38. The load drive circuit 38 controls the operations of the heater device 19 and the motor 20 according to the control signal.

The temperature of the analog voltage value input from the heat sensitive elements 25, 26, 27 to the microcomputer 28 is A
It is converted into a digital voltage value by the / D converter 32. On the other hand, the storage unit 30 stores a plurality of reference values corresponding to each temperature, and by comparing the output value of the A / D converter 32 with these reference values, it is possible to determine the temperature in multiple stages.

In the clothes dryer of this embodiment, three patterns of automatic end of drying operation are detected based on the temperatures detected by the first heat sensitive element 25 and the second heat sensitive element 26. When any one of the three patterns is detected, the drying operation is ended immediately or after a predetermined time is extended. Hereinafter, these automatic end detection methods will be described.

First, according to the first completion detection, after a predetermined time (for example, 15 minutes) from the start of the drying operation, that is, sufficient heat exchange is performed between the dry air and the clothes in the drum 4, and the drum outlet When the temperature becomes almost constant, the first thermosensitive element 25
Also, the difference between the drum outlet temperature detected by the second thermosensitive element 26 and the heater inlet temperature is set as the reference value A. Then, after the clothes are dried, the drum outlet temperature rises, the temperature difference widens, and when the temperature difference reaches a value obtained by adding a predetermined value B set in advance to the reference value A (A + B), the end is detected ( (See FIG. 6).

According to the second end detection, the first heat sensitive element 25 and the second heat sensitive element 26 detect after the start of the operation or a predetermined time (for example, 30 minutes) after the start of the operation. When the difference between the drum outlet temperature and the heater inlet temperature reaches a preset limiter value, the end is detected.

According to the third end detection, the end is detected when the drum outlet temperature detected by the first thermosensitive element 25 reaches a preset high limiter value.

The end detection is performed by such a plurality of methods in order to perform better automatic end detection corresponding to the type and amount of clothes.

Here, the B value, the limiter value and the high limiter value are determined by various experiments conducted by changing the kind and amount of clothes.

Furthermore, the larger the output of the heater device 19 is, the higher the temperature inside the drum 4 during the drying operation is. Therefore, the temperature of the drum 4 when the clothes are sufficiently dried is also the output of the heater device 19 is large. The higher it gets. Further, if the outside air temperature is the same, the temperature difference between the drum outlet and the heater inlet also increases as the output of the heater device 19 increases.
Therefore, the B value, the limiter value, and the high limiter value are
Different values are used when the heater device 19 operates at a high output and when it operates at a low output, and the value is smaller at the time of low output.

The (A + B) value, the limiter value, and the high limiter value set corresponding to the output of the heater device 19 correspond to the high output specified value and the low output specified value of the present invention, and these specified values. Are stored in the storage unit 30.

Next, a first operation example based on the above configuration will be described with reference to the flowcharts of FIGS.

After accommodating the clothes in the drum 4, the user presses a power switch (not shown) to turn on the power to the apparatus main body (S1), and then, using the selection key in the operation key group 33. Select a driving course and press the start key (S
2).

The drying operation starts, and first, the heater inlet temperature (T _IN ) is detected to know the ambient temperature (S3). Then, based on the ambient temperature, a clogging current value (I _LM ) that is a current value flowing through the heater device 19 when the heater device 19 itself or the lint filter 7 is clogged is determined (S4). This is because the current value of the heater device 19 is affected not only by the air flow rate but also by the ambient temperature.

Next, the motor 20 and the heater device 19 are turned off.
N (S5). At this time, the strength of the output of the heater device 19 depends on the selected driving course. Drum 4
Also, the double-sided fan 10 rotates and the clothes are agitated in the drum 4 and heat-exchanged with the heated drying air to dry.
This drying operation is continued until the above-mentioned automatic end detection is performed.

When the heater device 19 and the lint filter 7 become clogged during the drying operation and the air flow rate decreases, the current value of the heater device 19 decreases. Then, when it is determined that the current value becomes equal to or _smaller than the clogging current value (I _LM ) (S6), the control unit 29 stops the second heater 19b when the heater device 19 has a high output (strong). do it,
The heater device 19 is operated at a low output (weak) (S7, S
8). Next, it is checked whether or not the drum outlet temperature (T _OU ) and the heater inlet temperature (T _IN ) have decreased (S9). After that, the operation is stopped (S10).

If there is no abnormality, after 10 minutes have passed (S1
1) That is, after the output of the heater device 19 has decreased, the temperature inside the drum 4 has decreased to some extent, and then the control unit 29
The B value, the limiter value, and the high limiter value set for the above-described automatic end detection are changed to high output values, and the dry operation is continued (S12).

In this way, the clothes in the drum 4 are dried,
When any one of the above three patterns is detected to be automatically ended (S13), the heater device 19 is turned off (S14). The drum 4 and the double-sided fan 10 continue to operate to cool down the clothes by the cold air. Then, after 5 minutes have passed (S15), the motor 20 is turned off.
Then, the operation ends (S16).

FIG. 3 shows a second operation example in which the method for detecting clogging is different. The steps with the same reference numerals are the same as those in the first operation example, and therefore the description thereof is omitted here, and the changed step of detecting clogging will be described.

During the drying operation, the heater outlet temperature is detected by the third heat sensitive element 27, and the heater inlet temperature is detected by the second heat sensitive element 26 (S17). And
The heater outlet temperature is equal to or higher than the upper limit temperature (190 ° C.), or the difference between the heater outlet temperature and the heater inlet temperature is equal to the upper limit temperature difference (16
0 deg) or more, and if this continues for 1 minute, it is determined to be a clogging (S18 to S20).

[0041]

According to the structure of the present invention, the output of the heater is lowered after a certain period of time even when the heater is switched from the high output to the low output due to the detection of clogging during the drying operation. Due to this, when the temperature in the drying chamber drops, the specified value for low output is changed, so the specified value is changed as soon as the heater is switched, and the measured data value reaches the specified value. Will disappear.

Therefore, the drying operation does not end even if the clothes are not sufficiently dried, and the accuracy of automatic end detection of the drying operation can be improved, and a highly reliable clothes dryer is provided. it can.

[Brief description of drawings]

FIG. 1 is a flowchart showing a first operation example of a clothes dryer of the present invention.

FIG. 2 is a flowchart similarly to FIG.

FIG. 3 is a flowchart showing a second operation example of the clothes dryer of the present invention.

FIG. 4 is a side vertical cross-sectional view showing the configuration of the clothes dryer of the present invention.

FIG. 5 is a block diagram showing a control mechanism of the same.

FIG. 6 is a temperature characteristic diagram of a drum outlet and a heater inlet.

[Explanation of symbols]

 4 Drum (Drying Room) 10 Double-sided Fan (Blower Means) 19 Heater Device (Heating Means) 25 First Heat Sensitive Element (Temperature Detecting Means) 29 Control Part (Adopting Means, End Means, Delay Means) 30 Storage Part (Storage Means) ) 31 timer (delay means)

Claims (1)

[Claims] 1. A drying chamber for accommodating clothes, an air blowing unit for feeding drying air into the drying chamber, a heating unit for heating the drying air, which can be switched between high output and low output, and a temperature in the drying chamber. The temperature detection means for detecting and the high output specified value set when the heating means operates at high output and the low value smaller than the specified value for high output set when operated at low output. Storage means for storing a specified value for output, adopting means for adopting a specified value according to the output state of the heating means from among the specified values, and actual measurement made based on at least the temperature detected by the temperature detecting means When the data value reaches the specified value adopted by the adoption means, an end means for ending the drying operation, and when the heating means switches from a high output to a low output during the drying operation, the operation of the adoption means is predetermined. A clothes dryer, comprising: a delay means for delaying by a time.