KR940006251B1 - Drying time control apparatus for clothes dryer - Google Patents

Abstract

The dry time control apparatus includes a humidity sensor for sensing a humidity variation of the interior of a drum, a humidity sensing processor for varying a voltage according to the humidity variation sensed from the humidity sensor to a pulse signal, and a microprocessor for controlling the operation of a clothing dryer by checking a dry completion time, thereby reducing a dry time.

Description

Drying time control device of clothes dryer

1 is a schematic cross-sectional view of a conventional clothes dryer.

2 is a block diagram of the drying time setting system of the clothes dryer.

3 is a graph of temperature change with drying time of FIG.

4 is a schematic cross-sectional view of the clothes dryer of the present invention.

5 is a block diagram of a clothes dryer control system of FIG.

6 is a detailed circuit diagram of the humidity sensing processor of FIGS.

7 is a graph showing the change of humidity according to the drying time of FIG.

8 is a characteristic graph of the demister according to the humidity of FIG.

9 is an output waveform diagram of the humidity sensing unit of FIG. 6, in which FIG. 9 (a) and 9 (b) are waveform diagrams when humidity is high, and FIG. 9 (c) and 9 (d) are humidity diagrams. The output waveform diagram when is low.

FIG. 10 is a signal flow diagram illustrating the operation of FIG.

* Explanation of symbols for main parts of the drawings

1: motor 2: heater

6: humidity detection unit 7: room temperature detection unit

13: micom 17: humidity detection unit

The present invention relates to a drying time control of a clothes dryer, and to reduce the drying time of clothes by using a change in the resistance value according to the humidity of the humidity sensing unit, and to prevent an undry state generated during continuous operation. It relates to a drying time control device.

As shown in FIG. 1 of the accompanying drawings, a conventional clothes dryer is installed on an upper portion of the outer case 3 to rotate the drum 5 and a side wall of the outer case 3. A heater unit 2 for drying clothes in the drum 5, a drum temperature sensor 6 installed outside the drum 5 to sense an internal temperature of the drum 5, and the outer case (3) is installed inside the suction of the outside air by the drive of the motor (1) to the intake port (10) to cool the dehumidified hot air in the outer case (3) and suck the hot air in the drum (5) to dehumidify the flow path (9) Heat exchange fan (4) for discharging to the outlet 11 of the outlet), an exhaust temperature sensing unit (7) for detecting the exhaust temperature discharged to the dehumidification passage (9) of the outer case (3), and the heat exchange fan (4) Filter device (8) for filtering the outside air sucked by the) and the front case (3) The door 12 is configured to take out clothes into the drum 5.

FIG. 2 is a block diagram of a drying time control system of a clothes dryer, as shown in FIG. 2, wherein the internal temperature of the drum 5 detected by the drum temperature sensing unit 6 and the exhaust temperature sensing unit 7, The microcomputer 13 controls the overall system operation of the clothes dryer according to the exhaust temperature and the key signal of the key input unit 14, and the first, second, and third heaters H1- in accordance with the control signal of the microcomputer 13. The load driving unit 15 made of the triac (TA1-TA4) for driving the heater unit 2 of H3 and the motor 1 and the various conditions such as the drying time of the clothes are controlled by the control signal of the microcomputer 13. In the figure, reference numeral AC denotes an input AC power source.

In the conventional clothes dryer configured as described above, the user opens the door 12 to dry the clothes, puts the wet blanket in the drum 5, and presses the morpho key and the start start key of the key input unit 14. The triac TA4 of the load driving unit 15 is rotated to rotate the motor 1, the drum 5 driven therein, and the heat exchange fan 4, and only the gate of the triac TA1 TA1. The high signal is applied to turn on the triac TA1 and TA2. When the triacs TA1 and TA2 of the load driving unit 15 are turned on, the corresponding heaters H1 and H2 of the heater unit 2 are driven to gradually increase the internal temperature of the outer case 3. The blanket in the drum 5 is gradually dried. That is, the high temperature air in the outer case 3 heated by the heaters H1 and H2 of the heater unit 2 evaporates moisture contained in the wet blanket inside the drum 5 to change into air of high temperature and humidity. The changed air is delivered to the heat exchange fan 4 through a filtration device 8 installed at the center of the rear of the drum 5. The high temperature and high humidity air transferred to the heat exchange fan 4 exchanges heat with cold air sucked into the inlet 10 by the heat exchange fan 4, and the water condensed by the heat exchange is the dehumidification passage 9. The low temperature and low humidity air after the dehumidification is heated through the dehumidification passage 9 through the heater H1, H2, and then transferred to the drum 5 again to dry the blanket.

That is, for a predetermined time after the start of drying, the temperature inside the drum 5 is increased by the heater unit 2, but when the evaporation proceeds in earnest, the temperature does not increase any more and is kept constant, after which the evaporation is almost When the temperature inside the drum 5 rises again, the microcomputer 13 measures the temperature inside the drum 5 detected by the drum temperature sensing unit 6 for a predetermined time after the start of drying. If the internal temperature of one drum 5 does not reach the set temperature until a predetermined time has elapsed, the motor 1 and the heater 2 are turned off to stop drying, and a drying error is displayed on the display 16. When the internal temperature of the drum 5 detected by the drum temperature sensor 6 for a predetermined time reaches the set temperature, the drying rate is 90% or more, so that the heater H2 is turned off through the load driver 15. Drying continues during drying. This is to prevent the high temperature state lasting long because the blanket in the drum 5 is weak to heat. Thereafter, when the drying time has elapsed, the heater H1 is turned off and the heat exchange fan 4 is driven to dry for a predetermined time, and when the predetermined time elapses, the motor 1 is turned off to finish the drying.

However, such a conventional clothes dryer, when the temperature sensed by the drum temperature sensor reaches a set temperature, gradually reduces the heater's heat and finishes drying after a certain period of time. Since there is a difference in the temperature inside the drum according to a large amount and a small amount, the internal temperature of the drum may not rise to the set temperature when the quantity is large. Therefore, the drying degree until the drum's internal temperature reaches the set temperature is over 90%. If the drum's internal temperature does not reach the set temperature even after the drying time has elapsed, the microcomputer determines that the blanket is undried and starts drying. It stops and displays an error. In this case, since the drum is filled with blankets, the internal temperature of the drum does not reach the set temperature, but the blankets are already dried. For this reason, there is a problem in that the drying time is long or the dryness is determined as an undrying error even in a state of 100%.

The present invention, in view of the above-described conventional problems by adding a humidity sensing unit for detecting the humidity inside the drum and an indoor temperature sensing unit for sensing the temperature of the room to grasp the drying state of the clothing by the change in the resistance value according to the humidity change of the drum In order to shorten the drying time and to prevent the undried state generated during continuous operation, a drying time control apparatus of the clothes dryer was devised. Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

4 is a schematic cross-sectional view of the clothes dryer of the present invention, as shown in FIG. 4, on the motor 1 for rotating the drum 5 and the side wall in the outer case 3. A heater unit 2 installed to dry the clothes in the drum 5, a drum humidity sensor 6 installed outside the drum 5 to sense internal humidity of the drum 5, and the Installed in the outer case 3, the outside air is sucked into the inlet 10 by driving the motor 1 to cool the dehumidified hot air in the outer case 3, and the hot air in the drum 5 is sucked into the dehumidifying oil. Heat exchange fan (4) for discharging to the outlet (11) of the (9), and the indoor temperature sensing unit for detecting the air temperature of the room is installed inside the front of the outer case (3) sucked by the heat exchange fan (4) (7) and a filtration field for filtering outside air sucked by the heat exchange fan (4). It is composed of 8, and a door 12 which is installed on a front drawing out the clothes into the drum 5 of the outro case 3.

5 is a configuration diagram of a clothes dryer control system of FIG. 4, as shown in FIG. 4, a humidity sensor 17 for signal-processing a signal detected by the drum humidity sensor 6, and a humidity sensor 17. The microcomputer 13 for controlling the overall system operation of the clothes dryer according to the output signal of the) and the indoor temperature of the drum (5) detected from the room temperature sensing unit 7 and the key signal of the key input unit 14, and the micom The load driving unit 15 for driving the motor 1 and the heater unit 2 by driving in accordance with the control signal of 13 and the various states of the clothes dryer are visually displayed by the control signal of the micom 13 The note consists of a display section 16.

6 is a detailed circuit diagram of the humidity sensing processing unit 17 of FIGS. 4 and 5, and as shown therein, the voltage sensed by the humidity sensing unit 6 includes the resistors R3, R4, and capacitor C1. Signal processor 17a for integrating the integrated voltage and comparing the integrated voltage with the divided voltage through the resistors R1 and R2 to the comparator CP1 and outputting the resulting voltage through the resistor R5; The waveform outputted from the signal processor 6a is configured by a waveform shaping unit 17b for shaping the waveform through zener diodes ZD1 (ZD2), resistors R6, and diodes D1.

The operation and effects of the present invention configured as described above will be described in detail with reference to FIGS. 4 to 10.

First, when the user opens the door 12 to dry the clothes, puts the wet blanket in the drum 5, and presses the blanket key of the key input unit 14 and the start key for drying, the microcomputer 13 initially opens the load driving unit 15. By controlling the motor 1 and the drum 5 and the heat exchange fan 4 driven therefrom, the heater unit 2 is turned on to gradually increase the internal temperature of the outer case 3 while the drum ( 5) The blanket inside is gradually dried. That is, by heating the heater unit 2, the hot air in the outer case 3 evaporates the moisture contained in the wet blanket inside the drum 5 to change into air of low temperature and humidity, and the changed air is converted into the drum ( 5) is transmitted to the heat exchange fan (4) through a filtration device (8) installed in the center of the back. The high temperature and high humidity air transferred to the heat exchange fan 4 exchanges heat with cold air sucked into the inlet 10 by the heat exchange fan 4, and the water condensed by the heat exchange is the dehumidification passage 9. The low temperature and low humidity air after dehumidification is heated to the heater part 2 through the dehumidification passage 9 and then transferred to the inside of the drum 5 again to dry the blanket. That is, for a certain time after the start of drying, the temperature inside the drum 5 is increased by the heater unit 2, but when the evaporation proceeds in earnest, the temperature is kept constant without any further increase, after which the evaporation is almost When this happens, the temperature inside the drum 5 rises again.

6 is a graph of humidity change with drying time, in which the humidity inside the drum 5 is almost constant when the drum 5 evaporates in earnest. However, the humidity gradually decreases and then becomes constant again. At this point, drying is completed.

FIG. 5 is a detailed circuit diagram of the humidity sensing processing unit 17 shown in FIGS. 4 and 5, and the resistance value of the humidity sensing unit 6 changes according to the change of humidity in the drum 5 and is output as an electrical signal. The voltage output from the humidity sensing unit 6 is integrated through the resistors R4 and R3 and the condenser C1 of the signal processing unit 17a configured in the humidity sensing unit 17 as shown in FIG. The comparator CP1 compares the input integral value with the reference voltage through the resistors R1 and R2 and inputs the resulting voltage to the waveform shaping unit 17b through the resistor R5. The waveform shaping unit 17b waveform-shapes the input voltage to the microcomputer 13. That is, the humidity sensing processing unit 17 will be described in detail as shown in the waveform of FIG. 9, where Vi = Vc-Vo '= Vc-R2 / R1 + R2 * Vo. Where Vi is the input voltage of comparator CP1 and Vo is the output voltage of comparator CP1. If the input voltage Vi of the comparator CP1 is less than zero, Vo '= V _Z + V _D = Vo. If the input voltage Vi is greater than zero, Vo' =-Vo and the capacitor C1 is The exponential function is used to charge Vo by the time constant. At this time, the output voltage Vo 'is constant at Vo until Vc = Vo, and when Vc Vo is changed to -Vo by the characteristics of the comparator CP1. Therefore, Vc also discharges to -Vo. This charge and discharge causes sine waves to occur in Vo '. Since Vc (+) = Vo1- (1+) e ^{-t / RC} , the speed during charging and discharging depends on the values of the resistor and the capacitor. For this reason, the period T of the output voltage Vo 'is T = 2R _T C (1 = R1 / R2). Here, R _T = R 3+ (R _H // R 4) and R _H is the resistance of the humidity sensing unit 6.

As shown in FIG. 9, since the resistance of the humidity sensing unit 6 varies with humidity, the period T of the output voltage Vo 'also varies. That is, when the humidity is high, since the resistance value of the humidity sensing unit 6 is small, the period T between the ninth (a), the ninth (b) and the output voltage Vo 'is small, and the humidity is low. Since the resistance value of the sensing unit 6 is large, the period T becomes large as in the ninth (c) and the ninth (d) diagrams. In the above, the diode D1 of the waveform shaping unit 17b removes a voltage of 0 volt or less. In this way, the microcomputer 13 measures the output waveform of the humidity sensing processor 17 to determine the humidity inside the drum 5. That is, the microcomputer 13 detects the humidity at the completion of drying according to the room temperature (A) (B) (C) (D) detected by the room temperature detecting unit 7 after a predetermined time t1 after the start of drying. Set the resistance value (R _FH ) of the negative part (6) to R _A , R _B , R _C , R _D , R _E , and then check the humidity every certain time (t2) and if the checked humidity is the dry end humidity It is determined that the drying is completed, the load driving unit 15 is turned off to complete the drying.

As described in detail above, the present invention adds a humidity sensing unit for detecting humidity in the drum and an indoor temperature sensing unit for detecting the temperature of the room to grasp the state of drying the clothes by a change in the resistance value according to the humidity change of the drum. As a result, the drying time is shortened, and an undried state generated during continuous operation is prevented.

Claims (3)

Humidity sensing unit 6 for detecting the humidity change in the drum, Humidity sensing processing unit 17 for changing the voltage according to the humidity change detected by the humidity sensing unit 6 to output a pulse signal, and the humidity sensing Drying time control device of the clothes dryer comprising a microcomputer (13) for controlling the operation of the clothes dryer by judging the completion time of drying by the cycle of the pulse signal output from the processing unit (17). The humidity sensing unit 17 integrates the voltage sensed by the humidity sensing unit 6 into the resistors R3 and R4 and the capacitor C1, and integrates the integrated voltage into the resistors R1 ( A signal processor 17a for comparing the divided reference voltage divided by R2 to the comparator CP1 and outputting the resultant voltage through the resistor R5, and a zener diode (voltage) outputted from the signal processor 17a. A drying time control apparatus for a clothes dryer, comprising: a waveform shaping unit (17b) for shaping a waveform through a ZD1) (ZD2), a resistor (R6), and a diode (D1). The method of claim 1, wherein the microcomputer 13 sets the reference value of the humidity sensing unit 6 at the time of completion of drying according to the ambient temperature of the room temperature sensing unit 7 when a predetermined time t1 elapses after the clothing drying is performed. After that, by checking the internal humidity of the drum every predetermined time (t2), when the humidity reaches the drying end humidity, the drying time control device of the clothes dryer, characterized in that the drying is completed to complete the drying.